Design of a Household Electric Ironing Machine Citation Waldron, Robert Edwards (1949) Design of a Household Electric Ironing Machine. Engineer's thesis, California Institute of Technology. doi:10.7907/b39y-rp59. https://resolver.caltech.edu/CaltechTHESIS:06172025-205624103 Abstract The design of a household electric ironer was selected as the subject of this thesis in response to the functional deficiency in present types. A study of the existing market, consumer finances, preferences, and desires as well as problems of the distribution and sale of ironers est~blished important facts to consider in the design. These facts in addition to a functional analysis of ironing and the ironing machine together with a consideration of possible production methods led to the essential form of the unit. Further engineering and appearance refinement defined the final form. The proposed ironer consists of a roll with a main shoe beneath it. This shoe position provides maximum operator comfort and is the most rapid shirt ironing arrangement. A smaller shoe on the roll support enables the unit to iron ruffles and "in-between" areas. The unit folds up on end into a vertical cabinet which provides a working surface at counter height. Item Type: Thesis (Engineer's thesis) Subject Keywords: (Industrial Design) Degree Grantor: California Institute of Technology Division: Engineering and Applied Science Major Option: Engineering Thesis Availability: Public (worldwide access) Research Advisor(s): Unknown, Unknown Thesis Committee: Unknown, Unknown Defense Date: 1 January 1949 Record Number: CaltechTHESIS:06172025-205624103 Persistent URL: https://resolver.caltech.edu/CaltechTHESIS:06172025-205624103 DOI: 10.7907/b39y-rp59 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 17466 Collection: CaltechTHESIS Deposited By: Benjamin Perez Deposited On: 27 Jun 2025 21:05 Last Modified: 27 Jun 2025 21:26 Thesis Files PDF - Final Version See Usage Policy. 28MB PDF (Figure 23 Gear Housing & Roll Assembly) - Supplemental Material See Usage Policy. 872kB PDF (Figure 24 Table and Cabinet Assembly) - Supplemental Material See Usage Policy. 1MB Repository Staff Only: item control page

DESIGN OF A HOUSEHOLD ELECTRIC IRONING MACHINE Thesis by Robert Edwards Waldron In Partial Fulfillment of the Requirements For the Professional Degree of Industrial Designer California Institute of Technology Pasadena, California 1949 ACKNOWLEDGEMENTS The author wishes to acknowledge the kind assistance that was given him by Mr. E.S. Marples of Marples Gears, Mr. J.H. Adams of the Southern Californi a Edison Company, and the members of his faculty committee at the California Institute of Technology : J. Paul Youtz, Harry R. Greene, and Professor F;W. Maxstadt. He is also indebted to the following organizations for their cooperation: Los Angeles Times; Batten, Barton, Durstine & Osborne, Inc.; McGraw-Hill Publishing Company, Inc.; The Curtis Publishing Company ; Meredith Publishing Company; Lane Publishing Company; Scripps-Howard Newspapers; McCall Corporat i on ; United States Department of Commerce; Doehler-Jarvis Corporation; Chrysler Corporation; the United States Graphite Company; American Felt Company; Minnesota Mining and Manufacturing Company; Continental Diamond Fibre Company; Mission Electric Company; Bodine Electric Company; and to the manufacturers of the ironing machines analyzed and discussed in connection with the product investigation. To the consumers that participated in the market study, and the numerous dealers, demonstrators, and home economists that gave so freely of their time and advice, he also wishes to express his appreciation. ABSTRACT The design of a household electric ironer was selected as the subject of this thesis in response to the functional deficiency in present types. A study of the existing market, consumer finances, preferences, and desires as well as problems of the distribution and sale of ironers est~blished important facts to consider in the design. These facts in addition to a functional analysis of ironing and the ironing machine together with a consideration of possible production methods led to the essential form of the unit. Further engineering and appearance refinement de- fined the final form. The proposed i~oner consists of a roll with a main shoe beneath it. This shoe position provides maximum operator com- fort and is the most rapid shirt ironing arrangement. A smal- ler shoe on the roll support enables the unit to iron ruffles and 11 in-between 11 areas. The unit folds up on end into aver- tical cabinet which provides a working surface at counter height. TABLE OF CONTENTS PART 1. PAGE LIST OF ILLUSTRATIONS . . . . . . . . . . INTRODUCTION . . . . MARKET . . . . ... BACKGROUND. . . . . . . . . . . . . PRESENT CHARACTERISTICS OF MARKET . . . NATIONAL CONSIDERATIONS . . . . . . MARKET POTENTIAL . . . . . . . . DISTRIBUTION CHANNELS . . . . . . . SALES FACTORS. . . . . . . MARKET CONCLUSIONS . . . . . . . . . . . . . . . .. 4. PRODUCT STUDY . . . . . . 5. DESIGN CONSIDERATIONS . . . . . . INTRODUCTION. . . . . . . . . . IDEAL SOLUTION. . . . . . . . . MODIFIED SOLUTIONS. . . .. l 3 3 6 10 12 13 14 17 19 21 . . . . 21 23 25 ENGINEERING ANALYSIS . . . . . . . . TEMPERATURE & PRESSURE . . . . . IRONER SHOES. . . . . . . . . . . . ROLL SPEED. . . . . . . . . . . . . . . MOTOR & DRIVE MECHANISM. . .. SHOE OPERATING MECHANISM . . . . . . GEAR HOUSING . . . . . . . . . . . . ROLL . . . . . . . . . . . . IRONER TABLE . . . . . . . . . . RUFFLE ME CHAN ISM. . . . . . IRONER CABINET. . . . . . . CONTROLS . . . . . . . . . . . . . . . 35 35 36 38 38 40 41 41 42 43 44 45 7. CONCLUSIONS . . . . . . 46 8. APPENDIX . . . . . . . . . . . . . . . . . . A. MARKET DATA . . . . . . . . 47 B. C. D. ENGINEERING DATA. . . . . .. ASSEMBLY DRAWINGS . . . . . ESTIMATE OF COSTS . . . . . . . . . E• REFERENCES .• .• • .c . • • • • • • • • 48 60 68 70 72 LIST OF ILLUSTRATIONS Opposite Page Figure Photograph of Final Design Frontispiece 1. Population and Family Growth 10 2. Personal Income Trends 10 3. Income Distribution 11 4. Shirt Ironing Technique on Conventional Rotary Ironer 27 5. Shirt Ironing Technique on Thor Gladiron 28 6. Shirt Ironing Technique on Bendix and Ironrite 29 7. Cylinder Fitting a Ruffle 30 8. Garment with Converging Ruffles 30 9. Cylindrical Roll & Concave Shoe 30 10. Experimental Convex Shoe 30 11. Convex Shoe with Shoe Segment 31 12. Convex Shoe with Separate Roll 31 13. Convex Shoe with Endless Belt 32 14. Final Form of Ruffle Shoe 32 15. Ruffle Shoe mounted on Ironer 33 16. Thor Gladiron, Folded 33 17. Possible Folding Arrangements 33 18. Basic Design 34 19. Main Shoe Assembly 37 20. Ruffle Shoe 37 21. Thermostat Design 38 LIST OF ILLUSTRATIONS (CONT.) Figure Opposite Page 22. Performance Curves of Split Phase Induction Motor 38 23. Gear Housing & Roll Assembly 68 24. Table and Cabinet Assembly 69 25. Main Shoe Operating Mechanism 40 26. Cabinet Construction 44 27. Cabinet, Folded 44 28. Folding Mechanism 45 Photographs of Final Design -1- INTRODUCTION A product design must fulfill certain criteria. "Product design resolves itself simply and basically into the external organization of products to reflect their internal efficiency in (1) manufacture, (2) performance, (3) use. Improved appearance is essentially a look of efficiency, competence, stability, durability, simplicity, and honesty revealed with grace and charm 11 .--Walter Darwin Teague A preli~inary investigation of likely thesis subjects led to the observation that almost one half of the electric ironers in use today are used for flat work alone. For a supposed la- bor saving device, this was considered to be an unpardonable situation. In addition, only one ironer is in use for about , every eight washing machines. This would indicate a strong sales resistance on the part of consumers toward buying ironers. It was believed, therefore, that an improved ironer design was very defihitely in order. Due to the time involved, however, the problem was limited to the ironer alone and did not include the seating of the operator beyond the ordinary consideration of proper knee height and working height. The design was preceded by a thorough market and product study. Investigations were made into the distribution of the ironer market by geographic region, by income group, and by age groups. Investigations were also made into the consumer's preference for ironers by brand, and into his financial position. A study was made of the consumers objections to present ironers and his desires and needs in a new one. The character- istics of the consumer and the difficulties encountered in the distribution and sale of ironers were investigated. A study was also made of the ironers now on the market . A fundamental investigation was made into the technique of ironing and the ideal solution to the problem. The funda- mental machine was analyzed from the standpoint of ironing flat work, shirts, and ruffled, difficult areas. Folding mechanisms were studied and the essential final design proposed. An analysis was then made of the selected design. Proper ironing temperatures, pressures, and speed were established.. The proper motor, drive, and operating mechanisms were decided upon and the material and construction of each part was established. -3- MARKET BACKGROUND Although the electric ironer was introduced in 1907, the first spurt of consumer interest in household models is placed in the early 1920 1 s. The sales of ironers reached 40,000 units in 1925 at an average retail price of $150. In 1929, 126,COO units were sold at an average retail price of slightly over $76.00. Then, of course, in the early depression years, a down trend in sales occurred, reaching a low of 50,000 in 1932. At the end of that year, the estimated number of homes posessing ironers was 739,700 or 3.7% of the wired dwellings in the country(l)~ The length of time required to master the technique of using the electric ironer has been blamed for its relatively slow acceptance. Many women are naturally slow at mastering a mech- anical device. Hence they became discouraged in the learning period and went back to using the flat iron. Their reaction to the ironer, then, was unfavorable and was passed along to friends and neighbors. There was a marked increase in consumer interest in electric ironers by the middle 1930 1 s. This was helped along by the rising national income as compared with depression lows. At this time, there was an increased effort on the part of * Numerals in parentheses refer to references in Appendix. -4- dealers and manufacturers to promote ironer sales, especially to prospective washer buyers. This activity promoted some con- sumer research which revealed major sales appeals, and uncovered much information about women's attitudes and interests. A telephone survey, believed to be the first national sampling of ironer prospects, was conducted in 1935 by the Norge Division of the Borg Warner Corporation. It represented a high- er than average income group and revealed a current ironer saturation of 15.4%. A large proportion - 40.3% - of the groq> was interested in purchasing ironers the following year. The flat plate type was favored by 19.3% of the prospective purchasers, the rotary type by 49.3%, and the balance was undecided. The results indicated a reversal in the earlier trends toward the flat plate type. About 98% of all ironer owners used them regularly but 46.6% used them for flat work only. In 1938 there were approximately 26 manufacturers of household electric ironers. Five companies manufactured the flat plate type and the balance made the rotary type. ironers also appeared at about this time. Portable The Horton Company introduced their model with a free home trial offer to prospective washer purchasers. siderable acceptance. It sold for $29.00 and gained con- Horton attributed its popularity to the fact that it encouraged women to become familiar with machine ironing without their having to make a substantial financial investment. Also, the home trial feature, which let them prac- tice in private, gave the women confidence in their own ability -5- to use the machine. An official of the American Ironing Machine Company expressed the opinion that portable ironer sales would not affect console sales adversely; on the contrary they would eventually increase them by spreading interest in mechanical ironing and paving the way for later sales of console models to portable owners who might otherwise never have become interested in them. In 1941, the last full year of production before war stoppages, 259,668 ironers were sold, representing a retail value of 14.5 million dollars. There was an increase in the ratio of ironer sales to washer sales. In 1940, one ironer was sold for every 8.3 washers, while in 1941, one ironer was sold for every 7.3 washers. Production delays held 1946 sales to 175,000 units, but in 1947, sales rose to an all time high of 564,000 units. The ratio of ironer sales to washer sales con- tinued to increase, rising to one ironer for every 6.34 washers. In 1948, however, ironer sales dropped to 470,000 units. The ratio dropped as well to one ironer for every 9 washers. Although ironer sales dropped approximately 20%, from the 1947 level, they are still far ahead of any pre war year (see table I, Appendix A)( 2 ). The rather recent development of self service laundries may be a factor in further expanding the market for electric ironers. Empire Ironer, Inc. has started a development of con- siderable importance in introducing ironers into self service -6- laundries with its Ironerettes. It provides an opportunity for women lacking modern laundry equipment to become familiar with the operation and convenience of an ironer. Some believe that this development may do for the electric ironer industry what it has not been able to do for itself in 25 years - mace u. s. women electric ironer conscious. Despite the marked improvement in the promotion and sale of ironing machines, there is room for a good deal more. "Ironers are still in the stage where effort must be made to sell them. They are by no means yet in sight of the market which they should reasonably be expected to enjoy. Among established appliances it seems clear that there is no appliance on which increased effort and promotion on the dealer's p~~t could result in greater return than the ironing machine. 11 \l» PRESENT CHARACTERISTICS OF THE IRONER MARKET Geographical Distribution The number of homes in the country posessing ironing machines is 2,856,000 which is 8.1% of the 35,205,000 Domestic and Farm electric customers. An 11 year summary of ironer sales by States reveals that the biggest proportion of the total volume goes to the East North Central group which accounts for 31% of the sales, Tables II and III. Next come the Middle Atlantic states with 22% and third are the Pacific states with 15%. Another indication of the geographical distribution of ironing machine busiress is power company statistics for 1948. These statistics show that the biggest proportion of ironers sold in 1948 went to Pacific States with 15 ironer sales per -7- 1000 utility customers. Second highest was the West South Cen- tral - normally a poorer market - where 11 ironers were sold per 1000 customerso The Mountain, East North Central, and West North Central regions also were above the national average with 10 ironer sales per 1000 customers.< 2 ) Income Group Distribution Market studies conducted by the Milwaukee Journal, the Omaha World Herald, the Columbus Dispatch, the St. Paul Dispatch, and the Seattle Times indicate that ownership of electric ironers is considerably higher in the upper income groups, Table rv. (l) A survey conducted among the readers of the Sunset Magazine, representing a considerably higher than average income group showed that 24% in the North, 28.1% in the Central, and 21.7% in the Southwestern part of the country owned electric ironers.( 3 ) These figures are considerably above the national average of 8.0%. Age Group. Distribution Two studies conducted by Fawcett publications in 1947 showed the characteristics of young women compared with older women. They revealed that older women showed somewhat less interest in buying ironers than younger women largely because ownership of ironers was higher in the older group, tables V and VI. (l) Brand Preferences The preferred brands of electric ironers owned in Milwaukee, Omaha, Columbus, St~ Paul, and Seattle are Thor first, 4 General Electric second, and Kenmore third, table VII. (l, ) The preferred brands of ironers owned among the subscribers to Michigan Farmer, Ohio Farmer, and Pennsylvania Farmer in percent of total mentions are Ironrite 27.6%, Thor 17.2%, and Speed Queen 13.8%, table VIII.(l) The ironers preferred among the readers of the Sunset Magazine are Thor first, Ironrite second and General Electric and Easy approximately tied for third, table IX. ( 3 ) The overall most preferred brands appear to be Thor, General Electric, and Ironrite. Characteristics Desired in Ironers A study conducted by the Norge Division of the Borg Warner Corporation showed that the most important factors influencing buying decisions were labor saving first, time saving second, 4 and better results third, table x. ( ) In 1938, the Westinghouse Corporation conducted a study of the reasons why people had bought Westinghouse ironers. Labor saving led all other factors with 82% of the respondents naming it. Time saving was second, named by 66% • Manufacturer's name was third and better results and economy tied for fourth placefl, 4 ) Nevertheless, the owners of electric ironers have some serious objections to them. In order of importance they are: "Limited use - Too many housewives believe their ironers do too little of the work. Possibly they have not been sufficiently well instructed in the proper use of this appliance. Hard to Operate - Is closely related to the above. The difficult Jobs of ironing shirts, dresses, etc. cannot be done - even large flat pieces are hard for many to handle. Heat Control - And the difficulty Qf adjusting for proper heat is a minor objection. 11 \4/ Women want their appliances to do the complete job. They are irked by exaggerated advertising promises and point out that automatic ironers are not really automatic. They feel that if they have gone to the expense of buying one, they are entitled to one that will really do the work.( 5 ) Consumer St~dy In order to get some first hand information about consumer desires, needs and preferences, a sample survey was conducted in a typical middle class section !of Pasadena. of interviews with thirty consumers. It consisted Then dealers, demonstra- tors, and home economists were consulted for further facts and impressions. Four of the thirty owned ironers (13% compared to a 12% saturation for California). Of the four who owned ironers, one reported that she did everything on it but had some difficulty with gathers and ruffles. it only for flat work, doing all 11 Theotber three used fussy 11 work by hand. When questioned about a reasonable price for the appliance, answers ranged from $75.00 to $150.00 with most replies around $100.00. Another interesting fact learned was that space is at a premium in many homes. Many of the women thought that a uni t that -9A300 NO. OF FAMILIES 200 POPULATION I O0 1900 := I 00 0 1900 1910 FIGURE I. 1920 1930 1940 POPULATION ( REFERENCE 1950 AND FAMILY GROWTH 6 ) BILLIONS OF DOLLARS 250 2 25 200 175 I50 1946 FIGURE 2 1947 1948 PERSONAL INCOME ( REFERENCE 1960 7 ) TRENDS -10- would fold up to fit away into a small space when not in use was a good idea. It was noted that the women as a whole were blissfully unaware of the advantages to be had with an ironing machine. ers. Many had Just not heard nor thought much about iron- Others had seen some demonstrated and were not impressed. Individual research with dealers, demonstrators, and home economists further substantiated many facts that have already been learned about the ironer market. Women like to be able to use the top of the cabinet for a table when the ironer is not in usee Fifty percent or more of the people who buy elec- tric ironers buy them for flat work alone. Ironers are hard to keep sold, due largely to the long learning time involved and to inadequate demonstration. learning process on an ironer. is low. Many women are afraid of the More will try it if the price It takes a good deal of time and practice to learn how to use an ironer properly. If a woman is proficient with a flat iron, she is tempted to go back to it for everything but flat work. The investigation revealed further that Iron- rite has put out a model in a Walnut cabinet so it can be set up in a living or dining room as a piece of furniture when not in use. NATIONAL CONSIDERATIONS Since the ironer proposed in this thesis is purchased primarily by the family for family use, the important factors to consider in the national picture are population and family growth trends, the financial position of the consumer and -lOA- 46,300,000 SPENDING UNITS I I 39,'458,300 7,871,000 I I 39,287,000 I 11.0•4 I I ---- I 20,932,000 I 13,311,000 10,649,000 I 33,9% 53% UNDER I I 23% / ff 1000 I I I I I I I I 11,967,000 I ; 11,575,000 I 25% I I I 30.5°4 I I I I I 12,240,600 I I I I I 31. 0 °/• 1000 - 2000 I I I I I I I 2000-3000 / / / 9.7 "lo 3000-5000 OVER 5000 / l,5"65,300 4% 901.600 2.30,. MEDIAN INCOME 25 % I 21.1 % 3,8,8,800 11,575,000 I 8,306,000 I I ....___.~-- ~· 4,139,000 / / / 10.5% / / - - - 1,564,000 4'',i, 4,630,000 I 0% 1935-36 1941 1947 B 946 # 1500 $ 2300 FIGURE 3. INCOME DISTRIBUTION RE FERENCE 9 ) -11- home ownership and housing starts. The population of the United States has increased 10.5 million since 1940 and the number of families has increased 5.5 million in the same period, figure 1. The number of families are increasing at approximately twice the rate of population growth, indicating an expanding market for family use items particularly~ 6 ) Personal income has risen to an all time high of 215 billion dollars(?) with a third quarter (1948) average of 214 billion dollars. ( 8 ) It is nearly 3 times the 1939 level and more than 7 1/4 above the early 1946 level, figure 2} ) The median income has risen from $946 in 1935 - 36 to $2380 in 1948 (after taxes ??·) figure 3.(9) Nevertheless, there is a growing feeling of uneasiness among American consumers. Some of the highlights brought out in a survey conducted by the University of Michigan Survey Research Center in July 1948 are as follows: 11 1. Despite the higher incomes received by many of the repondents, the feeling that people were not quite as well off financially as they had been was slightly more widespread than in July 1947. About 40% of the spending units felt that their financial position had deteriorated over the past year, whereas only 25% felt that their situation had improved. 2. Spending units who were optimistic about the general economic outlook for the coming months constituted a smaller proportion of all spending units in July 1948 than they did in the earlier surveys. Since the survey early in 1947, the proportion has gradually declined from 55% to 41%. 3. Two of every three consumer spending units believed that prices would at least remain at their prese nt levels or possibly go higher during the n.-•xt year... Only aboutMQ~e in six saw definite prospects of price declines. 11 u..1J -12- A survey conducted for Sales Management puts it this way: "A substantially greater proportion of people as compared to 1947 are now 1. Doing more shopping around for values. 2. Buying less expensive merchandise as a temporary substitute. 3. Spending money on repairs instead of replacement. 4. Buying less expensive substitute brands instead of the preferred brand. One consumer in four, frightened at the prospect of running in the red, will not mak~ a~y purchase costing over $50.00 within the next six months.u\12J The final important factor to consider in the national picture is home ownership and housing starts. There are more home owners in the country now than ever before. About 18.5 million families own homes and approximately 17 million families live in rental dwellings. (lO) Experts expect 875,000 new homes to 3 be started in 1949 as compared to 925,000 in 1948. (l ) Builders have found that the market for homes selling above $12,000 is pretty well satisfied now. At the same time, the demand for houses selling for less than $8,000 is practically unlimited. The big problem that they now face is to get enough value into a $6,000 - $8,000 house to keep buyers happy. Many builders figure they cannot come down to that range without cutting the size of the house to 700 square feet or thereabouts. (l 4 ) Houses are getting smaller and smaller and must be given careful consideration in the design of new home appliances. MARKET POTENTIAL The ultimate potential market for ironers might be considered to be all the owners of flat irons in the country (97e5% -13- of the families(lS)). However, due to income and family size considerations, a much more reasonable estimate of the ultimate potential market is 50%, of the owners of electric washers (33.7% of the wired homes in the country)(l,Z). This goal probably will not be attained for a number of years and the estimate for the coming year will be based on more conservative figures. Ta- ble I shows 23 year sales, average price, and retail value of ironing machines. The nw.$.ber sold in 1947 and 1948 was 564,000 and 470,000 respecti~ely. A comparison of the brand preference figures indicates that of all the ironers owned, 20 - 25% were made by the Thor Corporation, while 10 - 12% were made by General Electric. Assuming that the ironer proposed in this thesis will be manufactured and distributed by a Company that has 1/5 of the market of approximately 500,000 units a year, it is estimated that 100,000 ironers can be sold the first year. The mar- ket has indicated a declining tendency and may decline even more, but with a good design and vigorous sales promotion, 100,0CD units can be sold. DISTRIBUTION CHANNELS Certain factors involved in the distribution of ironers should be considered in the design of the unit. Approximately two thirds of the output of electrical appliances follows the normal distribution channels of manufacturer to wholesaler to retailer to consumer while the remaining one third goes direct to retaile r, consumer or industrial user. (le) The largest pro- -14- portion of ironers seems to be handled by an exclusive distributor in an area who in turn supplies the retailers. At the present time, there is a certain reluctance on the part of retailers to handle electric ironers. It is caused by the fact that heretofore ironers have been hard to sell and hard to keep sold compared to other appliances. It takes a good deal of effort on the part of the retailer to demonstrate and instruct a new prospect well enough to make her a satisfied customer who may later be the cause of more business. It is this reluctance on the part of the retailer or sales resistance on the part of the consumer that must be overcome in a new design. In setting up effective distribution channels, it is of interest to know where the consumer likes to buy electric ironers. A study made for Printer's Ink in 1945 showed that the most popular retail outlets for the purchase of electric ironers were department stores first, Gas or Electric Company second, and Dealer Agent and Electric Store tied for third, table xr{ 4 ) A continuing home audit survey conducted by the Los Angeles Times in 1945 - 46 showed that the most popular retail outlets for the purchase of ironers in Los Angeles were department stores first and electrical appliance stores second, table XII~1~ SALES FACTORS In designing a product, it is appropriate to consider the characteristics of the prospective purchasers. Since women in- fluence the purchase of approximately 85% of the ironers sold, -15- it will be of interest to look into some of the general psychological characteristics of women as well as factors which cause them to buy. It has been found that there are three basic and distinct types of women to be considered. The first is the True House- wife whose sole interest is in .. her home; the second is the Ca- reer Woman who hates housework; and the third is the Ba~~nced Homemaker who has interests both in the world outside the home 5 and in efficiently managing her household. ( ) The True Housewife takes great pride and satisfaction in her ability to maintain a comfortable and well run household for her family. She considers herself indispensable and believes that no one else can handle her job. Her reaction to appliances is best expressed in her own words: 1 don't think there is any way to make housework easier for myself, because I don't believe that a machine can take the place of handwork. A machine cannot think and you can't rely on it; it doesn't do as thorough a job as a person. Oh, it might work easier in s9m~ instances, but it can never replace a human being.nl5J 11 The size of this group has diminished in recent years but still predominates the market, comprising 51% of the sample taken. The Career Woman is not necessarily a job holder. Indeed many in this group have never actually worked, but they feel imprisoned and unhappy in their homes. duties against their will. They perform household This woman's attitude is expressed as follows: 11 1 want a mechanical maid. That's what I want - a robot. -16- If they can make other things, they can make them too. 11 <5 ) While this woman buys appliances, her demands and ex.pe:ctations are apt to be unreasonable and unrealistic. She makes up 11% of the market. The Balanced Homemaker is from the market standpoint, the ideal type. She has an interest both in the world outside the home and in managing a well run househol d. She has confidence in her ability to do and enjoy either or both and hence is endowed with a well balanced personality. She has an intelligent and realistic attitude toward mechanical appliances; she readily accepts the help they can give but does not expect them to do the impossible. Obviaisly, then, the women in this group are the easiest to "sell" and are the manufacturer's best prospects~( 5 ) 11 Their number has increased recently and now makes up 31% of the total. On the basis of these findings, 31% of 40,525,000 famiilies in the u.s. in 1949 is 12,570,000 families in the country in which the lady of the house is a Balanced Homemaker. ber of homes with electric ironers is 2,856,000. The num- Selling at the rate of 500,000 a year with the number of families increasing at the rate of approximately 400,000 a year, it will take approximately 26 years to sell an ironer to every Balanced Homemaker. However, it is only wise to direct considerable edu- cational and sales effort toward the other two groups as well. Since approximately 85% of appliance purchases are .made by women, it is also appropriate to consider II how to sell the girls' o B.J. Kidd, author of the book Just Like a Woman, says to sell a woman, "Put it in her hand - get her to taste it or touch it have her try it on -r- let her push it around the floor to see how light it is. Do anything that will get her to make an identification of what you have(for sale with herself and her world, and your sale is made." 18; -17- That is especially necessary with ironers. see how it operates Just by looking at it. A woman cannot It must be demonstrat- ed proficiently and preferably within the natural setting it would assume in a home. The finished work might be put on dis- play for all to examine with a little sign on it to tell how long it took to iron. Many demonstrators are not very fussy ironers; on the other hand, many women are, and they will not be favorably impressed with a machine that cannot be shown to equal their standard of quality in less time. Women should also be encouraged to sit down at one and try it out for themselves, perhaps with the helpful attention of a demonstrator. Some manufacturers and dealers demonstrate their ironers. Sears Roebuck and Ironrite demonstrate f:feque ntly and guarantee a home demonstration for every new ownero A surprising number of dealers, however, make no attempt to demonstrate them or to instruct a new owner in their use. MARKET CONCLUSIONS The important facts pointed out in the above discussion, that have been considered in the design of the proposed ironer are as follows: 1. The ~~oner market is ripe for expansion with vigorous dealer efforts in their promotion and sale. 2. The largest proportion of recent ironer sales went to the Pacific and West South Central states. 3. Ownership of ironers is considerably higher in the upper income groups. -18- 4. Younger women are somewhat more interested in purchasing ironers than older women, probably because ownership is lower in the younger group. 5. The most preferred brands of ironers are Thor, Gener al Electric, and Ironrite. They may have some desirabl e characteristics. 6. Many women believe their ironers do too little of the work. They feel that they are entitled to one that will do the complete job. 7. There is a widespread feeling among consumers that they are worse off financially than they were a ye,r ago. 8. The ironer should sell for approximately $100. Homes are becoming smaller, necessitating more versatile and compact designs. 9. Sales resistance to ironers is high, largely because most women are afraid of the long learning time involved. A new design should require less learning time. The ironer's complete ability should be readi- ly demonstrable. 10. Vigorous sales efforts are needed in the ironer market. Ironers require frequent demonstrations and free trial arrangements. Every effort should be made to get the prospect to try it out. Career Women and True Housewives should be made the objects of educational campaigns. -19- PRODUCT STUDY An investigation of the ironers on the market revealed that although many claims are made for each and every one, none of them are capable of handling the complete family ironing task satisfactorily. Some are more versatile than others and some do better work than others, but there are certain types of work that none of them can perform satisfactorily. Ruffles and gath- ers, for instance, can either not be done at all or can be done faster by hand. Areas between two ruffles or two converging gathers just cannot be reached. Classified by function, there are three major types of ironers on the market. The first and most common makes use of a heated shoe located behind the roll. With this type of iron- er, the work is arranged on the roll and for convenience, the roll of many of them turns freely in either direction when not pressing against the shoe. Furthermore, only one end of this ifoner is free to use for anything but flat work. Since one end is used much more frequently than the other, many machines have two thermostats on the shoe so that the one on the unused side can be turned off when not in use. use of a shoe beneath the roll. The second type makes The work is arranged on a plastic forming board in front of the shoe. Both ends ·of the shoe are equally available for intricate ironing and only one thermostat is deemed necessary. Also, since the work is ar- ranged on the forming board, instead of the roll, it is not -20- necessary that the roll be free wheeling. flat plate ironer. The third type i$ a It consists essentially of a rectangular ironing board and a heated platen. and the clothing is fed by hand. The platen is hand operated The manufacturer recommends the use of a flat iron for intricate work and even provides a receptacle for one on the machine. A further classification of ironers by size reveals the portable and console types. The portable models are low in cost and are designed to be placed on a table of proper height for use. They are light in weight (28 - 34 pounds). Some come equipped with a table or tubular stand at extra cost. The con- sole models are complete in themselves. They are larger, ex- ert higher pressures, and do better work. They are also heav- ier, occupy more space and are more expensive. Rotary ironers today generally provide for continuous ironing; for stopping the ironer temporarily to give a "press" or to dry out very da:rp clothing; and for "steaming" - accomplished by turning the shoe to a horizontal position, putting a wet towel on it, and placing the material to be eteamed on top of th.at. Some of the machines have an intermittent stop and go action which makesf t possible to iron the same area repeatedly and which is said to give shirt collars a "polish" and linen a 11 sheen". Tables XIII and XIV in Appendix A give prices of several ironers on the market. descriptions and -21- DESIGN CONSIDERATIONS INTRODUCTION Before attempting to design an ironer, it is a good policy to establish a fundamental understanding of ironing. Ironing, as employed by the housewife, is the operation of ranoving wrinkles from textiles after they have been washed and driedG The clothing is usually dried completely first. be re-dampened and ironed. Then it must Ironing consists essentially of dry- ing a te~tile out in an unwrinkled condition. Any method of drying it out while it is in an unwrinkled condition, or of holding the material in an unwrinkled condition while it dries, will perform the same function satisfactorily. For instance, a handkerchief can be rendered wrinkle free by stretching it out on a flat smooth surface and allowing it to dry - very much as photographic prints are dried. Up to the present time, the fastest way to dry out textiles in an unwrinkled condition has been the use of a heated element to evaporate the moisture, while just enough pressure is applied to keep the material wrinkle free. The most common form of this type of device is the flat iron. Approximately 97% of the families in the country own and use electric flat irons(ls). Practically every housewife has learned to use one and can iron any type of garment with it to her satisfaction. The flat iron, then, can be considered the fundamental ironing device. Most usually, it consists of a 1000 watt heat- ing element distributed over an area of approximately 23 sqm:e -22- inches. The average weight is 3 or 4 pounds. The garment is pressed by moving the iron around on the cloth to remove the wrinkles while the heated element evaporates the moisture. The point on the iron allows the operator to get into the more intricate places although it is romewhat damaging to certain types of gathers. Recently, steam irons have been coming tnto some use. Their chief advantage is that they permit ironing, without previous dampening, of silks and synthetic fabrics, woolens and light weight cottons. These advantages are minimized, however, by the fact that many of these fabrics are used in garments which - in women's minds - do not need ironing or do not require perfection in ironing. Steam irons have some advantage over dry irons for pressing rayon and wool dresses, women's wool and rayon aiits, and men's and boy's suits, slacks, and sport clothes. They remove wrinkles more satisfactorily and impart to wool a 11 live 11 look. The steam in the iron takes the place of steam which would otherwise be supplied by a danp pressing cloth. However, the advantage is reduced greatly by the necessity of pressing these fabrics on the wrong side to prevent shine or with a pressing cloth between the iron and the fabric. Then the steam from the iron is of less value because the supply is not sufficient to penetrate a heavy pressing cloth (lS). In a survey conducted by the Bendix CbIJX)ration in 1948, it was found that 60% of the housewives named ironing as the -23- most disliked household task( 4 )_ If there are more than two or three people in the family, the weekly ironing, by hand, is a long tiring task for any woman. IDEAL SOLUTION The ideal solution to the ironing problem would be the use of textiles that dry wrinkle free after being washed and hung out to dry. Few washable fabrics in use today poasess that quality, so until the day arrives whn textiles are wrinkle proof, some means must be employed to take out the wrinkles after washing. Assuming that some machine will do the job, the ideal device has been expressed as follows: "I would like an automatic ironer, but I mean really automatic, so you could just leave the clothes and come back and find them ironed" (5) • This is the ultimate of course and at present is somewhat beyond the realm of practical possibility. Nevertheless, it is the goal toward which to work. The desirable characteristics of the unit can be set up. Probably the most important is that the machine should require as little human attention as possible. To be within the prac- tical realm of ach.i evement today, the machine must have an operator. Granting the necessity for an operator, the next consideration is~o make her comfortable. f To hold fatigue to a minimum, her required movements must be held to a minimum. Raising and lowering of the arms and reaching back and forth are to be avoided particularly. The largest single factor holding down the sale of ironers -24- today is the length of learning time involved. related to the above. This is closely A minimum of learning time should be re- quired by the ideal machine. If possible, the complete opera- tion of the machine should be obvious by just looking at it. Admittedly, this will be very difficult to attain, but there is room for considerable improvement over present types, especially in ironing intricate, difficult work. The ironer should be capable of ironing every item in the weekly wash. One principal objection to present ironers is their limited use. They do too little of the work. The machine should iron shirts and ruffled intricate work as readily as flat work. The ideal machine should be low in cost. The consumer study indicated that the price should be approximately $100. An important difficulty with present ironers is that the price of the good ones is too high. The present average price of ironers is 145 dollars which is considerably above $100. The jroposed combination of desirable features in the design will ma..~e the $100 price difficult to attain. The ironer must require a minimum of maintenance. Home ap- pliances take a good deal of abuse through neglect and the housewife's ignorance of their proper care. This indicates permanently lubricated moving parts and a finish that will stand up well for the expected life of the unit. Finally, since modern homes are small, the ideal machine should be compact in design and versatile in use. By this it is meant that the ironer should fold up to occupy a minimum -25- of floor space when not in use and that a surface of the folded unit should be provided at such a height and composition as to be useable for other things. The unit should be readily moveable from one part of the house to another and henca should be rather light in weight. The unit must have a design and finish that will fit in pleasingly with the contents of any room in the house. It has been found that the ultimate ideal solution is not possible of practical achievement today. However, it is quite possible and practical to incorporate many of the desirable characteristics of the ideal machine into a new design. Ack- nowledging the necessity of having an operator, it is possible to hold her fatigue to a minimum, to considerably decrease her learning time, and to enable her to iron every item in the weekly wash. It is also possible to make the unit compact, at- tractive and versatile in the home, but costs will have to be watched very closely to hold the selling price down to approximately $100. MODIFIED SOLUTIONS Basic Machine The basic ironing machine consists of one or more heating elements to evaporate the moisture from damp clothing and some method of moving the clothing over the heated element in an unwrinkled condition. There is an ironer on the market that ·consists merely of a heated platen with no means provided for -26- feeding the clothing over it. However, snce the operator must provide all the energy for feeding the material, the ironer cannot be considered much of a machine. The most common type of ironer in use today consists of a cylindrical roll that rotates against a concave mating shoe. The movement of the roll feeds the clothing over the heated shoe under a certain amount of pressure. The material is guided by hand into an unwrinkled condition and the pressure between the roll and the shoe holds it that way until the moisture has been driven out. Laundries, hospitals and hotels use ironers with two to six long rolls cooperating with a long steam heated shoe. Somewhat smaller es- tablishments may use a three roll arrangement in which one roll is heated either by gas or electricity. In all cases there is a heated element and some means of moving the materiaJ.over it. Flatwork The easiest taac the ir oner must be able to perform is the ironing of flat work. Flat work varies in size from hand- kerchiefs to sheets and includes towels, pillow cases, napkins, etc. The fastest way to iron a sheet would be torun it through a basic machine large enough to iron it in one pass. That is in fact what is done in laundries and housing establishments that use a large number of sheets. However, because of the space limitations in a modern home a 90 inch (width of a double sheet) roll is out of the question. The smaller flat work can be handled very nicely on a much smaller machine. Some laundries use special small f·lat presses, -26A- FIGURE 4. SHIRT IRONING TECHNIQUE ON ROTARY IRONER CONVENTIONAL 0 Slhk slun bac k on roll so 1h,11 rukt· 1s at t-..1,i,:c: o f ro ll. Iron ac ross hack o f sl11r1 , from slt'l'Vt: sc:a m IO slt·t·vc: St·a m, .is show n. Rdc:ast· shoe: Movt·shir110 ldt agai n .a nd iron kh unJt·rarm st·a m, in samt· mannt·r J S rii,:lu . Rd l·a.st· shoe:. 0 Fold yokl· .1ooss h,1d,; from arm Sl',trll 111 ar rn St".1111. ilwn plJn· roh · ,li a.i,:on:il lr on roll an,I iron up lo uillar. Rt· · k .t.sl" shoe:. nlon· shin m Id! 10 iron Ct·nl(·r pouum Rdl".lSl' sho,.: :1.i,:.un, an,! sli dl· slun 10 irun orhn si,lt· of yoh·. 0 Plact· bu11unholt- si,lt· of shirt on roll. rii,:h1 s1,lt· up. as shown . .ind iron from bouom 10 ar mpi1 . Ho ld as shown. 8 S1r,11,d11,·n sll·t·Vt·. us1n,-:. uri.lt·r,1rrn St· .1111 .1s ,-:ur,l,,:. Pl att' sk'l'\'t' ,m roll wuh t ull ,lown hdnw Jm,.·t·r nl.i,:t· of shoe:. I rim slt·n·t· f r 11m (ufl 10 shuuldt·r .u·am, usm.i,: prns1n.i,: uuurul hl ,lry uut ,luuhk 1h1l"kn,·ss .11 s,·.irn 0 lr.•n sl,·,·,·t· 11latkt·r. 1u1n 1n.i,: fr,u n ,urf 10 1·1t.l of pl.1d,,·1 on both sln-,·,·s. r N1 1t il lustr.1t1-..L I lr, in u.ifh . tirs, o n wron,i.: s1,lt·. liwn on nihc s1,il- Ho ld cuff hrmlr. shuwn, co pn·,·1·111 wrmkks. 0 Movt· shirt 10 ld r u nul from t·,1.i,.;t· of .atrnholt- St·a m 1s on t·, 1,-:t· of rol l. Iron up co coll.1rhan,l, ho ldm,i.: JS shown. Iron wron,i.: siJt· o f collJt fus1, kmn,-: of 1ht· shin han.i,: m·t·r tht· u1x·11 t·nd o f thl· roll. T urn, and iron t:ollJr on ri,-:lu si,lt·. Hol,I coll ar ti rml r . as shown. 10 prt·· Vt·nt tht· form ,Ulon o f wrmklt-s al 1ht· IXlinrs of rht· collar. 1ht· l'l(.>i,.1)- Plan · hu1wn -s1,lc..· of slun on rht· roll wuh thl· buuons tow:ml dw roll, an,I u o n up 10 lhl· col lJ rhJ11<\. 0 Pl.tel· buuun -s1dc: of shm lt·ni,:1hw1sc: on roll. ri>;ht s,,ll· up. Movt· roll fo rwar,I hr hand until buttons art· bc:low i;lux:, and iron from huuons io unJt·r Jrm st·.im . Rdt·:.&St · shlX'. 0 Mm•t· shin to ldt on roll. iu pt:rmu ironin,i,: right undc:ra rm scam. Iron ro h.1.r k s1,lt: of slt...·vt·, and rc:lcasc shoe: Ust· prt-ssmg con 1rol 10 dry out scam . tD Fold and crc:ast· yoke: as shown, and iron wdl on w slc:c:vc: of sh in . T u rn· 1hc: coll ar down. bu1 Jo not iro n 11. Butron t ht· coll ar hunon. cc:nlt·r and last huuons, and thc.- n fold . -27- just a little larger than the largest handkerchief for pressing handkerchiefs and napkins. Although very satisfactory for laun- dry use they are a little too specialized for the home. Flat work can be handled adequately by almost any basic machine. For sheets, the larger it is, the better. Since a 90 inch roll and shoe is much too large for a modern home, some equal segment of 90 such as 45, 30 1 or 22.5 inches will iron a correspondingly folded sheet. Shirts The ironing of shirts is considered by many women to be one of the most difficult types of work. The more shirts a man wears, the more particular he is likely to be about their appearance. Consequently the housewife is very fussy about the quality of wrk she performs on a shirt. The average wo- man cannot iron a shirt to her satisfaction in less than 10 minutes with a flat iron. - An ironer, therefore, should be able to equal her quality in 2 or 3 minutes or less. Laundries probably make use of the fastest metlhod of ironing shirts. They are ironed in large numbers on a mass produc- tion basis. Three special presses are used. The sleeves are done in one press, the front and back are done in another and the cuffs and collars are ironed in another press. The whole operation is very rapid and wonderful for a large number of shirts, but a little impractical for home use. The sequence of operations for ironing a shirt on a camventional rotary ironer, SJ>wn in figure 4, is a rather long and tedious procedure. Many of the s teps are awkward to per - FIGURE 5. Iron the collar Shirts »'ilh l»'O large gathers at yoke may not lie flat C'nough to iron as shown in Illustration 4 without causing wrinkling. In this case do not try to iron the whole yoke at once but do one gather and the part of the yoke directly behind the collar. Do the second gather when ironing the left shoulder. They may also be ironed by ironing around the body starting with the button front (buttons up) under the shoe. Iron to sleeve. Release shoe. pull shirt back, move to left and iron tail portion from buttons all the way across the back to side seam. Release shoe. pull shirt back and move to right, ironing from sleeve scam to sleeve scam. pulling out pleats or gathers over open end of roP. Remove shirt from roll and iron buttonholl' front in same manner as button front hut on wrong side of material. Women's and children's blous4..~s are easily ironed b)' ironing around rhe body as dC"~c:ribcd above. Center the unironed portion of yoke and adjust roll ( iust turn it with your hand) to start 6 or 7 inc:hes below back of collar. Iron to collar seam and stop. Release shoe and move shirt to left until left shoulder is lined uo with left end of roll. Iron over shoulder to first buttonhole. Now place the second sleeve in position, iron exactly as you did the first sleeve and remove fr.om roll. ~ow center the back of the shirt on the roll and iron :rom the tail to the unironed portion of the yoke. 4. Iron the back of the yoke Special Tips for Special Shirts Center the buttonhole band on the roll ("right" side facing shoe) so the edge of collar comes just over the right end of roll. Stretch slightly and press for a few seconds to finish smartly. 8. The finishing touch The collar may be done either by placing it the long way of the roll, doing first the under side and then the "right" side and using the "press" position each time, or it can be ironed at the end of the roll like the cuffs. "Shape" the collar with your fingers or iron in the crease over the end of the roll. A high finish may be put on collars and cuffs by gettin,2 them into the press position, "right'' side against the shoe, and working the roll back and forth a few times with the hands. 7. Iron cuffs around the left end of roll, first on the wrong side. then on the right side. For glossy sheen hold shoe at press position for a few seconds. Cuffs may also be ironed by running flat under shoe and pressing. :\fon shirt to the left until collar band lines up with right end of rolJ. Smooth out gathers and iron over the shoulder approximately to collar button. 3. Iron the shoulder portion of the yoke Smooth sleeve on roll so underarm scam comes di• reedy beneath the center of the shoe. Let the cuff hang over the end of the roll. Placket (slit in sleeve) should be facing you. Now iron around sleeve to button side of placket, stopping roll by using press position or releasing shoe to adjust fabric when neces• sary. Release shoe and slide i['oned sleeve to the left. 2. Iron the right sleeve first ... all but the cuff Hold shirt with front (l.,bcl side!) facing you. Put your left arm through the ri~ht slec\'C (starting with the cuff) and continue across the shoulder and throu~h left slC'e\'e until the entire shirt is threaded on your left arm. Place the fingers of your left hand on the end of the roll. Grasp the left cuff with your right hand and draw left sleeve over the roll. Continue drawing shirt onto the roll until the rif!/,/ sleeve is well over the roll and left sl,·eve and body of shirt han~ loosely o\'er roll support. 6. Iron the cuffs 5. Iron the front Take shirt by the collar and draw it toward you to bring tail again to starting point. Adjust to avoid armhole and iron to collar buttonhole. Turn shirt over and iron the button side the same way but on the wrong side with buttons cushioned against the roll. Not•- Normally you will have to take in an inch or two of the back \\·hich will not have been ironed as most backs are wider than the roll is long. 1. Place shirt in position on the roll SHIRT IRONING TECHNIQUE ON THOR GLADIRON I ~I [\) -28- form. The sequence of stepe for ironing a shirt on a Thor gladiron, shown in figure 5, constitutes a patented process (No. 2,280,720). First the left sleeve and the back of the shirt are slid over the roll and over the gooseneck of the ironer while the right sleeve is ironed (the roll of this machine is 3.25 inches in diameter). Then the yoke of the ea.rt is pulled out over the roll and ironed, and next the left sleeve. The rest of the shirt is done like flat work. number of steps is quite large. The The roll of this ironer is used like a sleeve board and consequently ie not very good for larger pieces. The sequence of steps for ironing a shirt on the Ironrite or the Bendix, using a shoe beneath the roll, figure 6, is rather difficult to understand completely from the photographs. Basically, there are five steps. The right sleeve and the left sleeve are ironed first, one on each end of the shoe. Then the back is ironed, all the way up to the collar. comes the right front and the left front. steps. Next Those are the five The ouffe and collar are then pressed. After observ- ing the three methods, trying out the first one and examining the results of them all, it was concluded that the last method was the fastest ~nd simplest. It also turned out the most professional product. Considering this method, then, as the most suitable for ironing shirts in the home, it may well be examined for other characteristics. In making use of a shoe beneath the roll, -28A- FIGURE 6. SHIRT IRONING TECHNIQUE ON BENDIX AND IRONRITE MEN'S SHIIITS (Slzr Hi and Largrr) Bc,:ausc of the flcxihili1y of the JR ONRI TE IRONER. h y ha,·inl{ two idcntil·al a nd us;1hlc open ends, ,·a rious j(a rm ents can he ironed in difh·rcnt ways. For innance, the fronts a nd hat,:k s o f shins un he ironed either anou o ( from chc ho uom up. to the nec:k. The most c.:ommon and fastc:u mc:thod used for s hiru, size I-; an d larRcr is as follows: SLEEVE, OPENING AT CUFF - )Yhcn the slcc,·c is made wich the fullness l{alhcn:d in10 the c.:uff hy pl,.- arinR , this may he ironed first hy fcc c.lin1,t the side of the plukct th at has the pll:':Us (or huttonholc side) in by puuin~ the ,.-uff end um.lcr chc roll and then iron 1he pkalL"lf scc1ion single. strail{ht down fla1 from the cuff with wronl{ sidt: w shoc . Fi p:. _\-;. Continue and finish 1he other side o f 1he pla<:ket o r ope ning in same ma nner. Lay the s lcc,·e on top o f the roll to s1rai11:h1en and smooth. ,..,~ . 17 CUFFS-Feed the cuff in flat on o ne side of the forming hoard with the wrong side next 10 1he shoe and iron co hody of slenc. Fig. 38. S1op and press. Turn the cuff o,·cr and iron the other or ri11:ht side of the cuff on 1hc opposite end of the forming board and shoe. This shows plainly how we do use the entire surface o f the shoe a nd not just one part of it all o~ the rime. To shape 1he cuffs after they are ironed. iron them around 1he ends of the roll. Fig. 39. BODY OF SLEEVE-I nscrt 1he hody of che sleeve at one open end of 1he shoe or ro ll , dropping the cuff below 1hc ro ll. If the fullness ac the l·uff should be placed in l(athers, 1hese a rc usually pl al·cd nea r the undera rm sca m and then when sta rtinR 10 iron 1he hody of the sleeve, these R•H hers can he spread out o,·er the end o f the pointed shoe and ironed ou1 perfectly: taki ng hold of the scam with the thumb and fore-finger, this fullnes s l·an he pulled ou1 ni<.:cly. Iron four or fi,·e inches or length of the opening or pl acket, with the slcc,·e on an an~ le. Fil(. 36. Raise roll, straighten slce,·e and iron up to a rmhole sea m, 1 Fig . 37, using left knee press <.:ontrol on the scam to <lry o u1 th_orouRhly. Turn the sleeve onr a nd iron the other side in the same man ner hy inserting the sleeve at 1he opposi1e open end of the roll a nd shoe . f"ig. JH ,.-;g. fig . .,, COLLAR-Feed the collar in flat wi1h the wrong side pl al·ed down upon shoe, Fil(. 4 _\, iron to the hody of the shirt and use the presser or left knee press <.·ontrol. Turn over and repeat. JI) BACK-Sta rt the 1ail of 1he shirt with the wrong side pla<.:c<l next 10 shoe, Fig. 40, and iron to armholes, Fig. 4 l, stop and raise roll. shift shirt slightly ma king Fig. -10 sure that ic is free from tht• roll and that the armholes are open a nd the points of 1he shoe a re fitted into the slee,·es. Continue ironinl( up on~r the iop of the back and onco yoke. Fi~. 42. Use ldt knee press control on the yoke to thoroughly dry it. Remo'"e chc .!ihin from the ironer afte r 1hc hack is finished hy takinR hold of chc slec,·es a nd lift up and toward che operator. fig . ., , FRONT-Lay 1he front, rig ht .side down to 1he shoe or forming board and feed it in a nd iron across the front to the a rmho le seam. In doing: this have one inch of neck band placed on shoe. FiJ(. 44. This will eliminate .some a ngling in o rder co iron the point of the front at the neckline. After doing the top of the front, .slide the shirt down on the forming board so as to mis.s the sleeve and finish the bottom of the front, ironing across to underar m sea m, and 1;1nder armhole. -29- the work is arranged on a smooth, cool, plastic forming boai,d in front of the shoe. This forming board is at approximately waist height and eliminates the necessity of having to reach forward over the roll to arrange the material. Both ends of the shoe are equally open for any type of work and will probably be used equally. Two corners of the shoe can be so shaped as to assist materially in the handling of certain short gathers as occur at the cuff of a shirt sleeve. Furthermore, the roll rotates forward with this arrangement instead of backward, causing all the hot steam to escape beneath the shoe and fol.low the roll up the far side away from the operator. A shoe length of approximately 24 inches will handle shirts size 14 and larger very nicely as shown in figur~6. ' Smaller shirts, then, must be passed diagonally over the shoe but present no difficulty. Ruffles and Intricate Work The task which has been neglected most in the design of ironers is the capability of ironing ruffles, of ironing between two closely spaced ruffles, and of getting into difficult intricate corners. While this capability is perhaps not the most important in itself, its deficiency makes the ironer incapable of ironing certain types of garments and renders the unit incomplete. There is no household ironer on the market that can iron ruffles faster than a flat iron. Difficult areas between two convergirggathers cannot be ironed at all. Considerable thought was given to the problem of ironing ruffles, gathers and difficult "in-between" areas. It was -29A- Figure 7. Cylinder Fitting a Ruffle Figure 8. Garment with Converging Ruffles -29B- SHOE ROLL FIGURE 9. CYLINDRICAL ROLL B CONCAVE SHOE Figure 10. Experimental Convex Shoe - 30- found that ruffles fit very nicely over the rounded end of a small cylinder as shown in figura 7. This cylinder could be a roll with a cooperating shoe that fit over it or the cylinder might be a heated ehoe over which the ruffles were passed. At the present time there is an ironer maiufactured for use by laundries by the Maxant Button and Supply Company for the purpose of ironing ruffles. It embodies the first arrangement mentioned, a roll with a rounded end and a cooperating shoe. While this arrangement w111 undoubtedly iron ruffles very satisfactorily, it still could not get in between two converging ruffles (see figure 8) unless sme arrangement were employed for varying the amount of shoe in contact with the roll, figure 9. Any such arrangement would be quite complicated and would undoubtedly prove confusing to the housewife. The other alternative is to make the heated shoe in the form of a cylinder or portion of a cylinder. The best diameter for this cylinder was found to be approximately three inches. It then remains to provide some means of feeding the material over the shoe. It is conceivable that the convex shoe could be mated with the roll, forming only a line contact, yet perform a satisfactory ironing Job by the operator's holding the material taut over the remainder of the shoe, figure 10. If such a shoe were found to iron -heavily dampened flat work satisfactorily, perhaps it would be possible to separate a small section from the main shoe for the purpose of ironing 11 hard to get at" areas between ruffles and pleats. Such a shoe was made up and tested -30A- ROLL ----- - -- - - ·-·- --- SHOE SEGMENT FIGURE 11. FIGURE 12. CONVEX CONVEX SHOE SHOE WITH MAJN RO LL MAIN SHOE SHOE WITH SHOE SEGMENT ROLL SEPARATE ROLL -.31- and found to have a few disadvantages. Since the Eh oe was only three inches in diameter, it had a limited working area, making it difficult for it to adequately remove the moisture from a heavily dampened piece of cloth in the same length of time as a shoe 4 or 5 inches wide. did pretty well. But with 24 watts per square inch, it The largest portion of the shoe was necessari- ly left exposed, providing a serious burn hazard. The last few inches of the material could not be ironed as well as the rest because a person could not very well hold his hand on top of the hot shoe while holding the material taut. A small segment of this shoe, operating independently of the rest of the shoe for intricate work, is subject to the same limitations mentioned previously; namely that a garment of the type shown in figure 8 would require a varying amount of the shoe to be in contact with the roll, figure 11. The mechanism involved would be complicated and confusing to the housewife. Furthermore, it would be almost impossible to use the segment of the shoe without burning hands on the main section of the shoe. It would appear that the smuller shoe should be separated entirely from the main shoe in order to function properly. Perhaps it could be installed separately on the other side af the roll support cooperating with its own smaller roll. The extra roll means added expense and the shoe needs at least two positions of contact with the roll as in figure 12. The ar- rangement is rather complicated yet and this type of shoe still presents a burn hazard. -31A- Figure 13. Convex Shoe with Endless Belt Figure 14. Final Form of Ruffle Shoe -.32- Another possibility would be a short convex shoe cooperating with an endless canvas belt as in figure 13. would be held under proper tension with a spring. The belt When in co- operation with the shoe, the belt would completely cover it and eliminate the burn hazard. The mechanism involved, however, ie even more complicated than before. Intricate difficult work would undoubtedly involve frequent change in direction and much stopping and starting and re-arranging of the clothing. The only times when this would not be so is in the case of long ruffled curtains. For the majority of ruffled work, then, perhaps power feed for the material is unnecessary. It may even be a hindrance. The simplest and nost versatile solution to the problem, then, would be a plain shoe shaped to assist in the handling of intricate details (see figure 14), one end to fit ruffles and the other end to get into difficult corners. The most convenient mounting position on the ironer would be on the upper right corner of the roll support, figure 15. An important characteristic of this type of shoe is that it operates very similarly to a flat iron. on~o its use immediately. Any woman would catch The particular shape of the shoe puts a maximum of heated surface in contact with the ruffle being ironed and hence dries it out very rapidly. A ruffle can be ironed in one motion as contrasted to the necessity of getting a pointed iron into every little gather. The disadvantages are that the shoe by itself is a burn hazard and that the last few inches of the material cannot be -32A- Figure 15. Ruffle Shoe Mounted on IrDner FIGURE 16. THOR GLADIRON, FOLDED -32B- U) 1- z w ~ w (9 (\J a: a: w Q CD ~ w CD ~ z <l: 0::: 0::: <l: :::, :::, z z (.9 z ---- -, 0 _J 0 LL w _J (Il U) U) 0 Cl. t-- w 0::: ::) (.9 LL ironed without burning the fingers. The way to get around these difficulties is to put a cooperating padded cover over the shoe. It would always remain close enough to the shoe that it would be very difficult to get a burn, yet its normal position would be distant enough from the shoe that material to be ironed could readily be slipped between it and the shoe. The last few inches of material would be ironed by lowering the cover onto the shoe either by hand or by knee. Folding Arrangement Because of the ever increasing shortage of storage space in modern homes, some method must be devised of storing the ironer in a configuration that will occupy as little floor space as possible. The Thor gladiron folds very simply (figure 16), but when folded it is below counter height, does not provide any useful working surface, is unattractive, and the roll is exposed to dust and dirt. Minimum floor space would be occupied by storing the ironer on end. In this event. one end sm.i!.d be at counter height (36 inches) in order to provide a useful working surface. The roll should be enclosed in a dust free con- tainer and the whole unit should present an attractive appearance in any room of the home. Two types of folding arrangements have been worked out of which the second has been selected as the most suitable, figure 17. Conclusions The factors considered in the above discussion have led to -33A- (§ (J) w 0 0 (J) <t: CD CD w a:: :::) <.9 u.... -34- the following configuration of the ironer: 1. The ironer will consist of a roll with a concave cooperating shoe for flat work and shirts. It will have an additional shoe for intricate work. 2. To minimize the fatigue of the operator and to make the ironing of shirts easier, the main shoe will be located beneath the roll. 3. For handling all flat work and shirts size 14 and over (the majority), the main roll and shoe will be approximately 24 inches long. 4. The roll will be approximately 6.25 inches in diameter. 5. The shoe for intricate work will be a portion of a cylinder shaped as shown in figure 16, located on the upper corner of the roll support, figure 15. 6. The folding mechanism is shown in figure 17. The en- tire ironer will appear substantially as shown in figure 18. -35- ENGINEERING ANALYSIS TEMPERATURE AND PRESSURE The design of an ironing machine requires an investigaticn into the proper ironing temperatures and pressures. The Gcod Housekeeping Institute has conducted some tests on the proper ironing temperatures for various types of textiles, but there does not seem to be any published material on proper ironi:qJ; pressures. The temperatures recommended by the Good House- keeping Institute are(lS): Rayon - Low and Nylon 300 - 350 F Rayon - High and Silk 350 - 400 F Light and Starched Cottons 400 - 450 F Wool Pressing 450 - 500 F Heavy Cottons and Linens 500 - 550 F It is generally conceded that temperature is more important than pressure in ironing. ably. The pressures in use vary consider- Flat irons vary in weight from 3 to 4.25 pounds distri- buted over an area of approximately 23 square inches giving a pressure range of .13 to .19 pounds per square inch. The Thor gladiron uses a pressure of 1.2 pounds per square inch and the Frigidaire claims the use of pressures between 2 and 2.75 pounds per square inch. Other ironers range between the two. The chief function of the pressure appears to be keeping the clothing unwrinkled while the heat of the shoe dries it out. In so doing, it assures intimate contact between the moisture -36- and the shoe, thus assisting the drying process. The movement employed in the use of flat irons obviates high pressures for them. The finished work performed by several ironers was ex- amined for a clue to the proper pressure to use. It appeared that proper pressures could very well be the subject of a long study in themselves. However, due to the limited time avail- able, and the necessity of considering other phases of the problem, it was decided to use 1.5 pounds per square inch ironing pressure. This pressure is included in the range of usual practice and yields good ironing results. IRONER SHOES Most ironer shoes are made of steel, chromium plated for corrosion °and scratch resistance. Two models used chromium plated cast iron shoes, and some portable ironers use aluminum extrusions. Sears Kenmore uses a stainless steel shoe. It is important that the main shoe of the proposed ironer has two conveniently shaped corners. It must be corrosion and scratch resistant and it must be simple and inexpensive to manufacture. The cast iron shoes in use are cast, machined and ground to proper dimensions and then plated. Cast iron has the very de- sirable property of storing heat, with the result that ironers so equipped handle very damp pieces with ease. However, the costs involved in the machining of the cast iron are considered prohibitive. Steel shoes can be pressed out, but it is then doubtful if the corners could have the desired shape. The method selected has been to die cast the shoes of 8-8 FIGURE A-A 19 8 ..,, MAIN CL. I 0 SHOE 0 0 © I I I ASSEMBLY ASBESTOS G) CLAMP G) GLASS WOOL A A 8 HALF 0 0 SCALE THERMOSTAT MICA ELEMENT ;!I B SUPPLY PHENOLIC FORMING BOARD ELECTRIC I I g: \,-I ~ -, I FIGURE ~ II I 20. J 'U~ l 111 I II I I 111 I 111 I --711: 111 ,::: I 11 I 1 111 I 111 111 \-- -7 - II II 111 11-I RUFFLE \ U> 0 --- i ~ \ / 1 B A I ---.: I \I / / / "' "--- ..... - II \ / /' ' 1 ; / '\ l / \ \ \ \ \ \ \ \. SHOE - \. '- I I i ' 'J.' / I / i I I / / I / / I / FULL --/ I ! ____ 7 ~ _\ \\- - - - -!, - - \---- - I , I SIZE "--~ \________ I_ - - - - - 7I I I I I / II ; _,-~---.I -1 I -~-j----II 1-------c--t, I I I II II I\ I \. I I A!/ !/ I I. ! I I II I II I I t r ,, I ~ I II \I I '1 II I I - -cc;I _ !.,.L 7 ._ \ --i-I - - - - - --" -~ -~ - - ,•- ~ - - - r I 1 --c- - 1 I ', I - _ - -:.. ~ - I. / ~- -/1f S: ::o ! I I I ! _L __ 1TJ I _J I I I I I -t I rr, I __I I I I _s I .,,. __.-_....-- _j I I I 1' ,,, ___ 1_ - 1 8 A I ,- ' SECTION SECTION WOOL 8-B A-A OVER GLASS ASBESTOS , - ELEMENT I !/ I /MICA I I tn \>I 0\ -37- aluminum alloy 218. They would then be sand- blasted and ano- dized for scratch resistance. Aluminum has the further advan- tages of high heat conductivity and light weight. Although a sulfuric anodized surface on aluminum is not as hard as chrome plated steel, it is nearly as scratch resistant. Tests of samples of each indicate that under ordinary use - including passing buttons and buckles through the ironer - the aluminum shoe would not scratch. The main shoe will be equipped with a 1500 watt nichrome heating element installed as shown in figure 19. The small shoe will have a 700 watt nichrome element installed as per figure 20. Both shoes will be constructed in substantially the same manner and each will be equipped with one thermostat. Since the main shoe has both ends open, they will probably be used equally, and only one thermostat will be required. thermostat will be of a special type, however. The In order to be able to use two shoes with 1500 and 700 watt elements as well as a 1/15 horsepower motor on a house circuit without overloading it, it is proposed to wire the heating elements as shown in figure 24, appendix C. Essentially the circuit is a blocking circuit preventing more than one ironing shoe from drawing current at the same time and yet keeping both shoes hot. The ironing shoe selector switch is put in the position to send current through the element that is about to be used. When this element heats up, the thermostat moves to its hot position and directs current into the other element through its thermostat. When both elements are hot, bot h thermostats move -37ASTRIP EXISTING THERMOSTAT TEMPERATURE CONTROL PIGTAIL THERMOSTAT DESIGN FIGURE 2 I THERMOSTAT 300 I w a cc I- MAIN 2 00 >- a AUXILIARY WINDINGS a w V I- z / / / / }' 0:: / 100 , - -- MAII-J w 0 er: w WINDING ~ 0 - / / 20 FIGURE 2 2 I al ~I (/) I I SYNCHRONOUS \ \ ~ ~, \\ \\\ e; I ii 40 PERCENT I 01 V ' 0 -~' I / / ALONE a.. I, I ~' / ~ ~ Ict / / - / / ::, 0 DESIGN 60 80 \ \ I 100 SPEED PERFORMANCE CURVES OF SPLIT PHASE INDUCTION MOTOR (REFERENCE ', -38- to their hot positions and shut off the current. It is believoo. that in this way both shoes will be kept hot enough to be ready for immediate use whenever put into use by the shoe selector switch. The thermostat design is shown in figure 21. ROLL SPEED The proper ironing speed varies with the dampness of the clothing and the speed with which the shoe can remove moisture from it. It depends on the heat input to the shoe, the size of the shoe and the material of which it is made. The speeds in use vary from 7.5 to 14 feet (0 on the flat plate) per minute. The fastest ironers had cast iron shoes of approximately 136 square inches of surface area supplied with 1300 watts. The slower ironers used steel or aluminum shoes supplied with 1200 watts. It is planned to use an aluminum shoe of 121 square inches of surface area, supply it with 1500 watts and iron at the rate of 12 feet per minute. A 6.5 inch roll would turn at 7.1 rpm to iron at 12 feet per minute. MOTOR AND DRIVE MECHANISM It is proposed in this design to drive the roll with the motor and close the shoe with a foot operated toggle linkage. With this arrangement, a smaller motor can be used and theemergency release mechanism can be eliminated. The shoe will be closed and the roll started with one movement of the foot pedal, leaving both hands free for manipulating the clothes at all timese -39- Present ironers are classed as automatic and non-automatic. An automatic ironer has been defined as one in which the closing and opening of the shoe as well as the turning of the roll is accomplished by the motor. Another definition is t hat a sin- gle motion of the knee control closes the shoe and starts the roll at the same timeo In either case, the advantage is that the ironer is operated by knee control, reducing arm movements and leaving the hands free for manipulating the clothes. The motor will be a 1/15 horsepowertplit phase induction motor (calculations in Appendix B). Its performance curves ap20 pear in figure 22< ). The motor has a high enough starting torque t0 start the roll under load if necessary but will normally be engaged with a clutch, figure 23, Appendix C. roll will have one speed for simplicity. It will iron at the rate of 12 feet per minute which is 7.1 rpm. speed is 1725 rpm. 1 is indicated. The The normal motor Hence a reduction of approximately 240 to It will be accomplished by the gear train shown in figure 23. The first step will be a 24 to 1 worm, fol- lowed by spu~gear steps of 4.5 to 1 and 2.2 to 1. The American Gear Manufacturer's Association recommends the following gear tolerances for a three inch gear: Tolerances Speed Class Ft/min Total II run out" Tooth Profile 1 80 .005 11 -.0015 11 2 400 .0015 11 -.00075 11 The worm turns at 298 ft/min and all the other gears turn at less than 80 feet per minute. Die cast gears comply approxi- -39A- Figure 25. Main Shoe Operating Mechanism -40- mately with Class 1. However, silence of operation is very im- portant in a home appliance. Since the silence of operation is directly dependent on the accuracy of tooth form, all gears will be cut. Furthermore, the last two spur gear steps must transmit loads (Appendix B) that cannot be handled adquately by any die cast metal save aluminum bronze and the Dohler Jarvis Corporation does not recommend die casting gears of aluminum bronze. In order to further contribute to the silence of opera- tion, the worm gear will be non metallic and the two spur gear steps will be provided with a hunting tooth. All metal gears will be machine cut from S.A.E. 1020 steel. In quantities of 100,000, gears can be cut at low cost. SHOE OPERATING MECHANISM The shoe operating mechanism is shown in figures 24 and 25, Appendix C. It consists of a foot pedal and actuating rod, a bell crank and toggle linkage, and a cam plate and shoe support. The foot pedal is either die cast or stamped, rubber covered, supported as shown and pinned to the actuating rod. The rubber covering is glued to the pedal with any adhesive similar to 3M EC - 870. The other end of the actuating rod is pivotally con- nected to the bell crank which actuates the toggle linkage. The toggle linkage rotates the cam plate which raises and lowers the shoe, through the shoe support, into and out of engagement with the roll. The shoe support is pivotally connected to the top of the ironer table so that it can be merely pulled out a- -41- way from the roll when desired to be used for steaming. The bell crank, and toggle links are stamped of S.A.E. 1020 steel. The cam plate is forged and coined from the same material and the parts are cadmium plated for corrosion resistance. The shoe support is die cast of S.A.E. 218 aluminum alloy. An Oilite type bushing is pressed into each end of the hole as shown,iln figure 24. GEAR HOUSING The gear housing of the ironer is one of the main structural members. It acts as the support of the roll under the 200 pound closing load of the shoe. are given in Appendix B. The stress calculations The housing will be die cast of alum- inum (Alsiloy #10, 10% silicon, 0.5% magnesium, remainder aluminum). It will be made in two parts. The left hand portion will be essentially a plate containing the roll support and the gear shafts, cast in as inserts. The right hand section of the housing will appear as shown in figure 23 and the two will be fastened together with screws. The gears will be enclosed in a bath of oil as suggested in the figure and the entire housing will be finished in white baked enamel. ROLL The roll of the ironer will be made of 6.0 inch steel tubing with two stamped ends spot welded in place. The ends will have dished out central portions that will be equipped with -42- Oilite type bushings, figure 23. The roll support consists of a 2.5 inch steel tube, pressed into the gear housing. The roll drive shaft will pass through the tube and fasten to the far end of the roll as shown. The near end of the support tube will be reduced in diameter and provided with an Oilite type bushing. To the roll will be glued approximately 18 inches of burlap. The last 8 to 10 inches of the burlap will be left un- glued and will provide a flap for starting the padding. Ap- proximately six feet of cotton flannel padding are rolled up on the roll and the whole thing is covered with a muslin cover with draw strings at each end. IRONER TABLE The ironer table is the other major structural element of the ironer. It will be stamped of 18 gauge sheet steel and is shown in figure 24. The gear housing will be fastened with screws to the rear edge of the table and to a reinforcing box section running between the gear housing and the left end of the table. Further reinforcing of the table top is necessary above the cam plate that actuates the main shoe. This is ac- complished by raising the forward portion of the top and spot welding a heavier plate in place immediately above the cam plate as shown in the figure. pendix B. The calculations appear in Ap- RUFFLE MECHANISM The ruffle shoe is made in the same manner as the main shoe and is fastened to a steel tube through which the electrical supply is fed, figure 23. The tube is knurled at point A and used as an insert in die casting the handle arm. The han- dles are compression molded of phenolic resin and attached to the handle arm with screws. A steel insert is provided in the right gear housing section, as shown. The ruffle shoe tube bears against the insert and does not cause excessive wear of the aluminum. A hole will be drilled in the housing to provide for a steel ball and spring. The ball will fit into a slot in the shoe tube shaped as shown in the figure. This slot will prevent the shoe from being pulled out of its socket and will provide 180 degrees of movement of the shoe with reasonably fixed end positions. The 180 degree limit is provided so that the supply wire will not be twisted excessively and so that either end of the ruffle shoe may be used as desired. The shoe cover pad mechanism is also shown in figure 23. The cover is stamped of 28 gauge sheet steel with the support clip spot welded in place. The supporting arm is stamped of 16 gauge steel, fastened to the housing with a press fit pin and attached to the cover clip with another pin. It is spring loaded in the open position for convenience of operation. The operating linkage consists of a knee lever, shaft, crank and operating wire, figures 23 and 24. The knee lever and crank Figure 26. Cabinet Construction Figure 27. Cabinet, Folded I ~ I ..f::- - 44- are stamped of 30 gauge steel and are spot welded to the shaft. The knee lever is rubber covered. The operating wire is lcoped through the cover support arm at one end and the crank at the other. The cover is equipped with a 1/4 inch thick felt pad glued in place. The felt used will be flameproofed S.A.E. F - 5. It will be glued in place with an adhesive similar to 3M number MSA-6003. IRONER CABINET The ironer cabinet will be made of 22 gauge sheet steel. The majority of it will be formed on a brake and spot welded together as shown in figures 24, 26, and 27. The upper sides are stamped out of the same die and are fastened to the cabinet with hinges. The lower front is stamped, the edges are folded over and it is screwed in place. The upper front forms the outer leg when the ironer is unfolded. hinged to the table top. It is stamped and The top of the cabinet forms the outer extension wing when the ironer is unfolded. It is also stamped and hinged to the outer leg, figures 24 and 28. The folding linkage is illustrated in figures 24 and 28. The linkage consists of a shaft and two side links. It has been decided to stamp both links of 12 gauge sheet steel and weld them to the shaft. Fixtures used for a run of 100,000 units would make this an extremely rapid operation. As the shaft of the lihkage is inserted into the table top, a counter balancing torsion spring is attached to its center. The pin Figure 28. Folding Mechanism I I t .p-o -45- in the shaft causes the spring to act between the shaft and the table top in a manner that tends to unfold the ironer. The lower end of the link is fastened to the case as shown in figure 24. A stripper bolt is screwed into a plate nut that has been spot welded to the inside of the corner post of the cabinet. The bolt has a shoulder on it at the bas·e of the threads. It jruns against the nut and locks in place. CONTROLS All but the press control of the unit are located in a small panel on the table top in front of the gear hous ing, figure 24. They consist of two switches and two lights. The first switch turns on the motor and the second switch selects the particular shoe that it is desired to use. One of the lights goes on when the main shoe is on and the other goes on when the small shoe is on. The press control is located on the front of the gear housing, figure 23 . It is a two inch knob fastened to an eccentric that disengages the motor clutch when it is desired to press garments. -46- CONCLUSIONS The ironer design resulting from this study is simple both in design and construction, moderate in cost, and will perform the complete household ironing task. The unit can be readily moved from one room to another, provides maximum operator comfort, requires little learning time, will iron anything, is low in cost, and folds up into a minimum space, providing a working surface at counter height. The design is such that it will materially assist dealers in its sale. Its unique as well as its regular capabilities are readily demonstrable. However, ironers still need a good deal of vigorous sales promotion to overcome consumer resistance that has been built up. The methods of manufacture have been selected on the basis of producing 100,000 units per year. The subjects of ironing speeds and pressures are worthy of further examination. There does not seem to be any pub- lished material on the subjects and the manufacturers of flat irons and ironing machines apparently have not conducted any controlled investigations into the problems. -47APPENDIX PAGE A. MARKET DATA 48 TABLE SALES OF HOUSEHOLD ELECTRIC IRONERS 1925 - 47 48 II SALES OF IRONERS BY STATES 1939 - 47 49 III OWNERSHIP OF IRONERS BY STATES 50 IV OWNERSHIP OF IRONERS BY INCOME GROUP 52 V OWNERSHIP AND PLANS TO BUY BY AGE GROUP 52 I VI VII II II II II II fl BRAND PREFERENCES IN IRONERS II II 52 53 VIII II II " II 55 IX II II II II 55 X REASONS FOR BUYING IRONERS 56 XI OUTLETS FOR PURCHASE OF IRONERS 56 XII XIII II " II PRODUCT STUDY XIV II B. ENGINEERING DATA II 57 58 59 60 1. MOTOR SIZE CALCULATIONS 60 2. GEAR CLACULATIONS 60 3. GEAR HOUSING CALCULATIONS 63 4. IRONER TABLE CALCULATIONS 65 C. ASSEMBLY DRAWINGS 68 D . ESTIMATE OF COSTS 70 E. REFERENCES 72 -48- TABLE I SALES OF HOUSEHOLD ELECTRIC IRONERS YEAR NUMBER SOLD AVERAGE PRICE 1947 564,000 $112.71 $63,571,200 1946 175,000 75.12 13, 146,0W 1945 30,000 1942 66,090 73.40 4,850,836 1941 259,668 55.80 14,489,056 1940 175,466 58.24 10,219,140 1939 127,093 68.46 8,700,786 1938 110,540 80,20 8,865,308 1937 178,858 70. 00 12,520,060 1936 180,281 57.60 10,384,185 1935 143,856 54.64 7,860,291 1934 116,069 53.38 6,196,420 1933 69,991 49.16 3,411,230 1932 50,000 70.00 3,500,000 1931 80,000 84.00 6,720,000 1930 100,000 76.00 7,600,000 1929 126,000 76.48 9,637,000 1928 92,000 93.00 8,556,000 1927 68,000 160.00 10 , 880,000 1926 57,000 154.96 8,833,000 1925 40,000 150.00 6,000,000 RETAIL V.AL UE (Compiled by 11 Electrical Merchandising" and the American Washing Machine Mfrs. Assn . ) -49- TABLE II ELECTRIC IRONERS ... Sales by States, 1939-1947 1939 1940 1941 194! 19"6 1947 Total S.,lcs (Unib ) (Unib) (Unib) (Unib ) (Unib) (Unib) (6 Yun) - - - -Maine New Hampshi re .. Vermont .. MasSdchusetts . Rhode Island Connecticut. - - - - - - - - - - -- -- New England New York . New Jer<ey Pennsylvan ia . - - -- - -- - East North Central Minn esold Iowa ... Missouri .. North Dakot. . South Dak ot. Nebraska. Kins.as . 858 1 723 360 I 5,139 ! 596 1 2,702 1,061 893 492 8,110 981 14,225 132 53 59 1,839 , 633 ' 1,404 1 735 308 205 3,728 I 821 906 I 3,379 1,600 771 14,345 3,142 34,915 6,884 4,141 2,269 36,814 6,748 56,187 .50 .30 .16 2.66 .49 4.07 7,9H 10,378 H,76ll 4,110 I 6,703 ! 58,151 113,043 8.18 12,375 4 592 12,266 18,085 6 781 18,973 I 26,046 8 ,614 26,257 7,231 1 450 7,462 13,868 3 882 14,860 43,688 I 15 353 46,415 I 121,293 40 ,672 126,233 8.78 2 95 9 .14 ll9, U3 43,139 I 60,917 I 16,143 31,610 105,456 181, 191 ll0.87 11 ,578 iI 4,926 9 ,493 10,020 3,314 13,480 I 5,209 17.018 12,017 5,680 23,340 8,691 22,082 19,690 8,562 7,020 2,446 6,598 5,221 3,078 20,007 9,029 24,436 12,090 7,11 4 59,634 19,206 38,531 37,345 12,923 135,059 49,507 118,158 96,383 40,671 9.78 3.58 8.56 6.98 2.94 39,331 I 53,404 H ,365 14,3631 71,676 167,639 439,771 31 .14 3,378 2,042 3,190 265 309 1,335 914 3,598 2,885 3,908 371 318 1,342 1,311 1,553 1,191 1,615 1 989 1,707 86 I 99 I 508 244 3,711 3,021 I 4,685 616 598 I 1,505 ! 1,659 12,271 13,634 16,124 2,134 1,719 6,343 5,453 32,277 25,759 35,494 3,817 3,393 12,586 10,772 2.34 1.86 2.57 .28 .25 ,91 .78 1J,7JJ to,tos 5,141 15,101 57,671 114,098 '·" 261 1,336 1,036 620 1,334 686 166 812 955 397 1,803 2,083 1,505 2,449 959 228 1,843 1,653 138 738 600 336 613 171 59 343 250 154 1,402 1,333 1,1 46 2,052 1,402 547 838 1,060 830 5,394 4,624 5,809 7,232 5,987 2,430 6,876 7,529 2,147 11,920 10,859 10,125 15,463 I 9,579 I 3,556 11,183 12,171 i .16 .86 .79 .73 1.12 .69 .26 .81 .88 3,141 9,934 46,711 17,00J 6.30 1,402 2,3 77 855 291 5,335 9,129 3,794 2,608 11,089 16,805 6,439 3,554 .80 1.22 .46 .26 to,166 37,887 1.74 906 1,265 1 ,642 3,779 3,320 5,394 5,632 18,376 5,272 9,133 9,973 30,062 .38 .66 .72 2.18 11,433 367 1,247 1,183 709 1,783 374 126 471 724 Delaware Maryland. District of Columbia . Vir9inia . West Virgini a. North Carolina . South Carolina Georgia . Florida .. . 6,914 ! Mississippi . East South Central Te xas ... West South Central . . Montana. Idaho . . Wyoming .. Colorado . New Mex ico . Arizona . Ut.h. N evada. ··.. 1· Mountain. W,shington . .. O regon . . Ca lilomia. i ' Pacific TOT AL UNITED ST A TES 7,704 1 3,182 5,880 ~:~ I 1,106 ~ 1 , n o I 1,028 866 468 , 169 I i 988 1,396 400 185 1,901 2,338 718 261 435 699 204 40 I 1,969 s ,111 1,371 1,u1 Arkansas ... Louisian1. Oklahoma. I I I I Kentucky T~ nessee. A labama ol Total I · Ohio. Indiana . Illinois . Michigan . Wisconsin . . ·; 119 I 564 I 382 3,653 575 2,035 -- Middle Atlantic . . 1 I I I ' 4,915 I I I 247 489 716 1,595 352 719 765 2,093 394 989 1,007 3,402 53 277 211 817 3,047 3,919 1 S,791 1,351 7,591 31,7H 54,440 3.94 548 42 7 276 1,166 181 332 708 229 895 426 185 1,547 64 374 1,449 173 827 643 188 1,882 148 642 1,219 183 250 105 13 415 26 99 343 53 393 205 120 1,21 4 342 462 923 103 1,897 1,126 533 4,446 1,245 1,778 2,905 1,719 4,810 . 2,932 1,315 10,670 2,006 3,687 7,547 2,460 .35 .21 .10 .77 ,14 .27 .55 .18 I 3,167 5,11J 5, 731 1,304 3,761 15,649 35,417 1.57 2,706 1 1,464 13,039 4 ,584 2,534 24,512 6,858 2,104 29,805 1,226 653 6,875 2,394 1,419 13,184 14,049 8,773 65,088 31,817 16,947 152,503 2.30 1.23 11.04 11,!09 I 31,610 Jl,767 1,754 16,997 17,910 101,167 14.57 1!1,S6J I, 171,!01 II sn,1u 1 1141 1,31, 100.0% I H7,671 I I 65,916 171,000 I I Prepercd by Marictt Anel'(ffl [)eputmant. ELECTRICAL MERCHANDISING. from fi1 .. u compll.d by the Ametiain w.wa., .nd lrona Manuf•cturcrs Auoc~ti°" JANUARY , 19 49 - ELECTRJCAL MER CHANDISING -50- TABLE III OWNERSHIP OF ELECTRIC IRONERS BY STATES (reference 2) State Total Elevtric Customers with Electric Ironers %of State Electric Customers Maine New Hampshire Vermont Massachussetts Rhode Island Connecticut 15,841 11,183 6,732 88,188 14,613 79,049 6.87 14.74 New England 215,606 8.52 New York New Jersey Pennsylvania 262,080 91,582 271,035 6.80 7.28 10.64 Middle Atlant ic 624,697 8.16 Ohio Indiana Illinois Michigan Wisconsin 268,404 88,453 225,627 191,762 77,376 13.13 8.63 10.52 11.75 8.55 East North Central 851,622 10.99 Minnesota Iowa Missouri North Dakota South Dakota Nebraska Kansas 70,439 47,342 75,714 8,663 8,346 28,785 24,544 9.41 7.15 8.22 8.81 7.29 West North Central 263,833 8.01 Dela.ware Maryland Virginia West Virginia North Carolina South Carolina Georgia Florida 5,251 24,184 34,884 18,393 6,514 22,384 21,477 6.84 7.62 3.30 8.7§ 2.35 1.82 South Atlantic 179,367 20,244 6.4 6.94 6.52 6.94 9.69 5.41 3.68 3.53 4.37 -51- TABLE III (continued) State Total Electric Customers with Electric Ironers %of State Electric Customers Kentucky Tennessee Alabama Missi~sippi 21,501 29,296 13,713 5,857 4.09 4.83 2.54 1.86 East South Central 70,367 3.54 Arkansas • Louisiana Oklahoma Texas 8,343 16,780 23,317 62,291 2.40 3.42 4.91 3.87 West South Central 110,731 3.79 Montana Idaho Wyoming Colorado New Mexico Arizona Utah Nevada 13,020 9,716 5,086 25,686 3,831 9,491 18,028 3,861 9.37 6.23 8.49 8.64 3.46 6.20 10.82 10.88 Mountain 88,719 7.94 Washington Oregon California 75,050 43,787 332,221 11.89 11.07 11.82 Pacific 451,058 11.76 2,856,000 s.11 TOTAL UNITED ·STATES -52- OWNERSHIP OF IRONERS BY INCOME GROUP (reference 1) TABLE IV Figures expressed in percent of total respQndents. Milwaukee Omaha Columbus St.Paul Seattl e Prosperous 20.4% 16.4% 25.8% 20.4% 26.0% Comfortable 14.7 8.0 17.2 9.3 Getting by 12.5 6.0 15.5 8.8 Poor 11.0 4.0 11.5 9.0 TABLE V OWNERSHIP AND PLANS TO BUY BY AGE GROUP (Fawcett publications,reference 1) Figures are expressed as percentages of the total of 8000 women interviewed would like to own plan to buy Age group own 18-30 7.0 47.9 9.4 31-65 10.8 38.3 7.8 TABLE VI OWNERSHIP AND PLANS TO BUY BY AGE GROUP (Fawcett publications, reference 1) Age group owned plan to buy under 26 7.3 12.7 26-35 11.3 11.6 over 35 17.0 s.o 9.3 TABLE VII BRAND PREFERENCES IN IRONERS - Milwaukee, Omaha, Columbus, St. Paul, & Seattle (references 1 & 4) Figures are expressed in percent of the total number of families owning ironers. Brand Milwaukee Omaha Columbus St.Paul Seattle General Electric 14.3 5.6 12.3 16.8* 8.2 Thor 14.3 39.2 10.3 14.7 24.0 Kenmore 8.5 5.6 1.5 1.2 14.8 Westinghouse 8.4 9.1 7.9 2.7 Conlon 7.9 ----- 4.9 3.0 4.7 Ironrite 7. 2 8.3 6.0 2.3 9.1 Simplex 6.6 2.0 3.7 6.1 5.8 Horton 4.9 2.3 7.0 2.3 --- Hotpoint 3.7 2.7 4.4 * 3.2 Universal 3.5 2.3 2.6 1.8 3.1 2.0 1.6 Speed Queen 2.6 4.0 1.2 1.9 1.8 Easy 2.4 5.3 6.0 4.9 4.5 Apex 2.3 2.7 3.9 4.2 3.2 AMC (Lazarus) 1.4 Norge 1.3 2.7 Maytag LO 2.0 A. B. c. Meadows Bendix 2.3 --- LO 6.8 ----- 1.7 1.3 1.0 1.2 -54- TABLE VII (continued) Brand Milwaukee Omaha Frigidaire --- --- Columbus St.Paul --- Montgomery Ward 1.0 6.8 Sunbeam 2.5 3.7 1.2 Fairday --- --- American Beauty --~ 3.2 Proctor --- Prima White House Seattle 1.8 --- 1.0 --- 1.0 ---- * Included Hotpoint (see General Electric). __ ,.... ----- -55- TABLE VIII BRAND PREFERENCES IN IRONERS - Michigan, Ohio, Pennsylvania • (reference 1) Figures expressed in percent of total mentions Brand Michigan Ironrite 35.7 Thor 21.4 10.0 Speed Queen 14.3 20.0 General Electric 7.1 10.0 TABLE IX Ohio Pennsylvania Total 60.0 27.6 20.0 17.2 13.8 20.0 10.3 BRAND PREFERENCES IN IRONERS - Readers of Sunset Magazine (reference .3) Figures expressed in percent of total mentions Brand North Central South Thor 16.0 21.2 26.2 Ironrite 17.4 13.1 9.2 Easy 7.2 L3.8 12.4 General Electric 18.8 8.0 9.2 Sears (Kenmore) 8.7 3.7 14.6 Conlon 7.2 4.4 2.3 Montgomery Ward 5.8 2.3 5 .. 8 2.3 Simplex o.o o.o o.o 3.7 4.6 Westinghouse 4.4 2.2 2.3 c. 2.9 2.2 2.3 17.4 16.1 12.3 Apex A. B. All Others -56- TABLE X REASONS FOR BUYING IRONERS - Norge (Reference 4) 1937 1936 Time saving 25.9'% 26.9<% Labor 38.0 47.0 Better results 11.7 11.5 Economy 13.0 LS Price 1.4 2.2 Maker & Dealer 6.8 0.8 All Others 1.7 5 .. 0 Don't Know 1.5 5.0 TABLE XI OUTLETS FOR PURCHASE OF IRONERS - Printer's Ink (reference 4) Will Buy From Electric or Gas Company 23.8% Department Store 28.6 Hardware Store 7.9 Dealer Agent 20.6 Electric Store 20.6 Others 1.6 Don't know 1.6 No answer 1.6 -5'7- TABLE XII OUTLETS FOR PURCHASE OR IRONERS Los Angeles Times (reference 17) Type of Store for Purchase Department Stores 25.2% Electrical Appliance Stores 13.0 Furniture stores 2.3 Other 6.8 Don't know 52.7 Name of Store Barker Brothers Eastern Columbia 1.5 Edison Company 0.8 Elsters 1.5 General Electric 0.8 Star Outfitting Company 2.3 Sears 18.3 Taylors 1.5 Thor 1.5 Western Auto Supply 1.5 Other 18 . .3 Don't know 49.7 -58- TABLE XIII iRONER ELECTRICAL IRONING RATING SPEED WATTS FT./MIN MAKE MONITOR 1080 BENDIX 1212 UNIVERSAL } SIMPLEX SPEED QUEEN A MC HORTON APPEARED IDENTICAL 1 ( AUTOMATIC) 1250 PRODUCT STUDY S HOE RO LL CHROME PLATED STEEL 22 OPERATING HANDLE IN SPEED ONE X 5.375 OPERATING 7.5 MODELS FEATURES SIZE 22 .5 X 5.375 10 PORTABLE PRICE FRONT. ONE SPEED HANDLE IN I 57. 95 FRONT $ 65.45 $ 64. 95 15 75 9 CHROME PLATED STEEL 22 X 6.0 AUTOMATIC IRONING 8 PRESSING CONTROL. COULD BE ADJUSTED FOR OPERATION EITHER BY HAND OR BY KNEE . $ 69 .95 $44. 95 $49.95 $ 79 . 95 $ 79.95 HOTPOINT GENERAL ELECTRIC 1275 7.5 CHROME PLATED STEEL OR ALUMINUM 22 X 6.0 NONE . 11 00 7 CHROME PLATED STEEL 21 EMPIRE ] FAIRBANKS MORSE ARMSTRONG X 5.25 ELBOW CONLON 1230 ALUMINUM 22 X 5.0 CONTROL ( NON AUTO.) TABLE XIV THOR 1620 GENERAL ELECTRIC ] HOTPOINT ) 1575 GE~ERAL ELECTRIC H6TPOINT HORTON 1575 9 CONTROL IN PRODUCT STUDY IN IRONER ALONE $ 5 9. 9 5 WI TH STAND $ 69. 95 WINGS 8 PANEL $ 7 9. 9 5 FRONT IRONER ALONE WITH STAND FRONT CONSOLE MODELS CHROME PLATED STEEL 2I X 3.5 PATENTED METHOD OF IRONING SHIRT (AS ON SLEEVE BOARD). FOLDS UP WHEN NOT IN USE, OCCUPYING 1.75 SQ. FT. OF FLOOR SPACE. 1.2 PSI. ONE SPEED. CHROME 30 X 6.0 TWO SPEEDS 26 X 6.0 ONE SPEED. HAND OPERATED PLATED 8 $ 54. 9 5 $ 74.95 $ 99.5 0 $ I 99.95 PRESS. STEEL 5 GENERAL ELECTRIC ( HOTPOINT 1575 SPEED QUEEN ] UNIVERSAL SIMPLEX 1500 CHROME PLATED STEEL 0 J 300 SQ. IN. ALUMI~ No NUM. CALROO ELEMENT. 9.5 CHROME PLATED STEEL. NICHROME 1350 W. ELEMENT ROLL X 6 .0 RUFFLER SHOE. FOLD-AWAY PLATES FLAT ON $ I 69 .95 CABINET. PLATE. 1.3 PSI EACH END OF NO COVER COVER $ I 99. 95 $ 229.95 ONESPEED TWO SPEED $154.95 $ I 6 9 .95 $ I 79.95 -60- AP P E NDI X 1. B MOTOR SIZE CALCULATIONS Roll rpm to give 12 ft. per min. ironing speed 1TDn - 12 - 12 n = 144 6.5 11'" = 7.06 rpm. D:: 6.5 ~?~~ = 242 to 1 reduction Assuming a coefficient of friction of 0.4 between the shoe and the roll, 200 x 0.4 = 80 lb. tangential force on the roll. 80 x 3.25 = 260 lb. in. torque required on the roll. ;.p required= 2 Tr T n : 33,000 6.28 x 260 x 7.1 _ _ 0293 12 X 33,000 - To allow for gear friction and possible rough usage, use JP : . 03 x 2 :: . 06 2. = 1/15 ;P motor approximately GEAR CALCULATIONS 'JlI Ir llI I .. ---. :rr ', ~ dear Pitch Diameters: I-0. 6~1; IV- 3. e'; II- 2.41; v- 1. ~•; III- o. 778~ VI- 2. 7'' -61- 2. GEAR CALCULATIONS (CONTINUED) Number of teeth: II - 48; VI - 27 III - 14; IV - 63; V - 12; Gear no. I is a double threaded worm; ratio 24 to 1, threaded length of 0.857 11 Load capacity of worm gearing (reference 21 pp. 401,402) n = rpm of worm= 1725 R = gear ratio= 24 to 1 K = pressure constant (table 58, p.402 reference)= .0125 (C = 1.53) Q= R+R2. 5 : • 905 450 m• 450 + V + 3V : .573 R V = peripheral velocity of worm at pitch line = 1T" x . 66 -~ 1725 : 298 ft. /min. 12 _ 1725 IP - 24 x .0125 x .905 x .573: .466 Tooth size of worm gear C = 1.53 11 c· 875= 1.451 C:: center distance between worm & gear in inches. 1 451 worm pitch diam. (p. d. ) : 2. "2 = •66 b = face width of gear: 1 51: .484 11 ·3 F:: 1r sby P.i p_, = diametral pitch V:: 72 x tr x 2 • 4 12 F: 33,000 15 x 45.2 s b I. - tr48.7 PJ - ::: 45.2 ft./min. : 48 • 7 lbs. s = safe working stress for non- metallic material (reference 22). -- 6000 (~~~. 2 T.25): 5170 psi. y ;:. . 129 (table 2 reference . 22) Pea X .484 X .129 -- 3.14 X 5170 :. 20.8 use 20.0 48.7 -62- 2. GEAR CALCULATIONS (CONTINUED) Length of threaded worm {p. 404, reference 21) L: .157 {4.5 + :~) = .857 11 Gears noo III & IV Spur Gearing - tooth strength Tensile strength of 1020 steel: 70,000 psi From table 47, page 360, reference 21, a factor of safety of 5 for steady load on gears of a train be-· yond the first mesh is assumed since the non metallic worm gear and the rubber clutch half absorb the shocks. b; lO {p. 361 reference) Pel 1725 24 V: 72 X 1T X .78 12 = 72 rpm (gear III); = 14.7ft/min. -- 13,670 = 10 7r s y_ . F: 33 000 - 150 lbs . 15 14.7 - s :: 14,000 ( 600 600 + V ·) F = 7T" s b y_ -12!,: 31.4 X 13,670: 2860; y 150 p~ : .108 x 2860: 309; use p_, : 18 and b =. b = .612 11 ratl· o -- ~ 14 ; 2 ' PJa Pd X y for 14 tooth, 20° stub involute; .108 (table 46,page 359, reference) PJ :: 17.6 i; ; pitch diam. = ~::: .778 (Gear III) 18 x 3.5 = 63 teeth on gear IV = 4•5 t 0 l 11 -63- 2. GEAR CALCULATIONS {CONTINUED) Tooth Strength - Gears n o . V & VI v = 16 72 43-- 16 rpm {gear V) ; s :: 14,000 {~) F = 13,870 psi; = 1T s b y = 10.5 11' sy . PJ p dl x;1 x l.Z: 5.02 ft./r.ai.n. F: 33,000 15 x ·5.02 : 438 lbs. y for 20 stub involute {12 teeth) = . 099 ' ~ = 33 ~3~3, 870 : 1045 pf = 1045 x .099 = 103.3; i~ :: Pd = 10.15 use 10 b :: L0.35 11 1.2 11 PD (gear V) ; 2.7 x 10 = 27 teeth on gear VI; ratio : ~~= 2.25 Check on roll rpm i~ X f~ X 24:: 243 to 1 3. j .l1.2.6. -- 7.1 rpm 243 GEAIR HOUSING CALCULATIONS /04.3 - - +- ~ " '1 170.S A 15.5 1 ZS'' A y 11 -64- 3. GEAR HOUSING CALCULATIONS (CONTINUED) Bending stress at the table top: M = 104.3 x 7.5 + 170.5 x 6.25 = 1850 lb. in. 1: 5.5 X 167 - 5 X 125 :: 8.94 in3 33 C s = Mc I = 1850 :: 207 psi • 8.94 ' Torsion at critical sections: Yield stress in tension for aluminum~ 25,000 psi critical section for 104.3 lb. force= 5.5" square (A - A) 8 T = .,,..2t..,..(.,....a---t""""),...,(.,,...b___t-.-) cr~tical section for 170.5 lb. force:: 5.125 x 4.5" reference 23 p. 5-50 (B - B) 170.5 X 15.5 _ 2645 s.sr.:::a)-.5-(.....5,.....-1-25---.-2"""5..... )..,..(4........,,5,....--.2"""'5"'"").--- - 10.36 s _ 104.3 X 15.5 ~A -~ .5(5.25)% - 1618 - 13.75 : 117.8 psi • b en d"ing -- -1618 -- 235 psi• Maximum 6.89 ¢ombined stresses (p 13 reference 21) s s,_, = J 235Z + 3(255{ : 250 psi =[ 235 + 3(255);,. J.•F = 500 psi s.t 4 4 2 = 255 · psi -65- 4. IRONER TABLE CALCULATIONS / 70.S lb I 4-07 lbs . / 70 .S' lb s /2.8/ I/ - i- ~38-- ~ /04-.3/b I i : f3o.>< SEC TIO/II ' /.~2.s fFilliY. y l_lddj_~.2S' 1 -=- - 7.o -.-: !' T --, ;<-- .080 S-77.S lbs . Max. bending moment= 170.5 x 12.81 3 3 1. : b , d , - ba, dg c 6d 1 cI_- 2.447.5- 1.42: • 136 n3 = 2187 lb. in. • l. ultimate tensile= 60,000psi .. - 16,100 psi s = 2187 .136 - yield strength= 38,000psi ultimate shear Transverse shear (max.) s6 : :g~4 : 1088 psi Torsion in box section S - - 170.5 X 7 + 104.3 X 1.625 .16(1.37) = 6230 psi Maximum combined stresses: = 7318 psi j 16,100 2.+ 3(7318/- = 10 , 250 psi s 3 total= 6230 + 1088 s _ , ..el - 4 s-t.,.,:. 20,500 psi - 65,000psi -66- 4. IRONER TABLE CALCULATIONS (aeNTINUED) At the point of connection of the box section and the gear housing, the box section is reduced to an angle. Hence reinforcement will be required. ~ of box section= .136 in3 A I - b I BH l - bh c of a channel= SH - 3 h (page 21, reference 21) V A channel of 16 gauge st ee 1 gives B -- 1.00 11 ! I i ;:,,J ! H y ' ~ --- B -- --::::,.. -I -- 8 - 126.23 - .1475 in3 C H = 2.00 11 2187 s - .148 - 14,830 psi h = 1.88 11 b = 0.94 11 Reinforcement above cam plate 170.S- lbs . 4.S'''- 7 GA VGe == .1793 -< l...rc- 3.s "- t~ I I c.J I/ t, .7S - -- -- bha. c-c 08.4- lbs 82 . I lbs . l - (page 20, reference 21) - 4.5 X .032 -= .024 in3 Ccc-c) 6 s = 287 .024: 11,960 psi 6 y Toggle Links with a minimum section I -67- 4. IRONER TABLE CALCULATIONS (CONTINUED) Toggle links (continued) Links take 200 lbs compression with possible 1/2 11 eccentricity. M: 200 x 1/2 = 100 lb. in. A: .125 in 2 ; - 9,600 psi s = 100 00104 200 s = .125 = 1600 psi s total= 9600 + 1600 = 11,200 psi Links take 30 lb. in. bending_ about y - y s - 30 .0052 = 5,775 psi s - .!Q_ = 80 psi , - 1/8 Actuating rod from foot pedal Euler formula (pinned ends) (page 26, reference 21) ,rZi;, T F= ~ 12 Using a 1/4 11 tube with .030 11 walls (D04 - DL4 ) -- • 0001275 in4 I -- ,JI;,. 0"% D0 = .25 11 ; F : 9.86 X 30 X 10' 484 X .000125 rod actually takes 10 lbs. Di = .190 11 ; - 1 : 22 11 - 77.7 lbs. -70- EST I MATE OF COSTS Material Gear Housing Main Shoe Ruffle Shoe Main Shoe Support Sheet Steel Wt. lb. Unit Cost 5.1@ .22/lb. 3.0 @ .22/lb . 0.5 @ .22/lb. 0.5@ .22/lb. 100.0 @ .07/lb. 1.12 .66 .12 .12 7.00 Indirect - Dies and Special Tools f 10,000 Gear Housing Main Shoe Ruffle Shoe Table Top Upper Front Top Upper Sides Shoe Support I I i 5,000 2,000 2,000 2, 000 2,000 500 500 .24 Labor & Overhead Cabinet Operation Die operations Spot Weld Paint Time - sec. 16@ .05 per 256 70 326@ .06/min. X 3 .80 .98 Table Die operations Spot Weld Paint 2 @ .05 per 256 .10 40 296@ .06/min. X 3 .89 Die operations Paint 2 @ .05 per 20 @ .06/min. X 3 .10 .06 Die operations Paint 8 @ .05 per 20@ . 0 6/ min. X 3 .40 Die operations Paint 2 @ .05 per . 20@ .06/min. X 3 .10 .06 Die operations Paint 2 @ .05 per 20 @ . 06/min. X 3 .10 .06 Top Lower Front Upper Front .06 Upper Sides Assembly Roll Lower Front Hinges 128 60 128 - 71- ESTIMATE OF COSTS continued Labor & Overhead Assembly Item Fold Link Gear Housing Shoes Toggle Time - sec. 240 600 600 240 1996 @ .06/min . x 3 Miscellaneous Parts Motor Gears Switches Spring s Cord Forming Board Roll padding and cover Heat ing elements The r mostats TOTAL NANUFACTURING COS'11 Unit Cost 6 . 00 5 . 00 1 . 50 .20 . 01 .30 . 50 . 80 2 . 00 1 . 60 -72- APPENDIX E REFERENCES 1. Caroline E. Aber, Notes on the Market for Household Electric Iron~, Research Department, Redbook Magazine, (November 4, 1948), pp. 1-3, 5-6, 7, 10. 2. Anonymous, Electrical Merchandising, Ironers, (January, 1949), Vol. 81, No. 1, pp. 52, 53, 62, 63. Anonymous, Sunset Magazine, Lane Publishing Co., (January, 1949), pp. SP42-648-3C, SP42A-648-3C. This data is not to be released to the trade in any form. _[ t is for the confidential use of sales and advertising executives only. 3. Anonymous, The Market For Washing Machines, Ironers and Clothes Dryers, Research Division, Meredith Publishing Company, {January 24, 1948), pp. 9, 15, 16. 4. Anonymous, Homema_~ing and Appliances, Crowell-Collier Research Department, {1945), pp. 6-9, 51. 5. Anonymous, Modern Plastics, Markets ... Present and Future, (May 1947), Vol. 24, No. 9, pp. 94-97. 6. 7. Anonymous, Survey of Current Business, The Business Situation, (October 1948), Vol. 28, No. 10, pp. 1-11. Anonymous, Federal Reserve Bulletin, Expenditures & Incomes in the Postwar Period, (November 1948), Vol. 34, No. 11, pp. 1329-38. 8. 9. Arno H. Johnson, Harvard Business Review, Market Potentials, 1948, (January 1948), Vol. 26 , No. 1, pp. 11-31. Anonymous, Monthly La_por Review, 1948 Survey of Consumer Finances, (November 1948), Vol. 67, No. 5, pp. 515-16. 10. Clarke L. Fauver, Federal Reserve Bulletin, Financial Position and Buying Plans of Consumers, July 1948, (November 1948), Vol. 34, No. 11, pp. 1355-1359. 11. 12. Anonymous, Sales Management, Consumers Growl and Get Tough in Face of High Prices, (Sept. 15, 1948), Vol. 61, No. 6, pp. 37-9. 13. Anonymous, Electrical Merchandising, The Outlook for 1949, (January 1949), Vol. 81, No. 1, pp. 49, 268. -73 14. Anonymous, Busirass Week, Builders' Goal: Cheaper Houses, (March 5, 1949), No. 1018, p. 21. Anonymous, Survey of Buying Intentions, Redbook Market Research Department, (July 1947), p. 10,30. 15. Thornton B. Moore, The Outlook for the Electrical Appli ance Industry, United States Department of Commerce, (October 1, 16. 1948), p. 2. 17. Anonymous, Los An eles Times Continuin Home Audit, Los Angeles Times Research Department, October 1945 - April 1946). The Los Angeles Times does not authorize publication or reproduction of any part of this report without written J:B rmission, and specifically prohibits the use of this material in the promotion of any product or company. Margue rite Fenner, Electrical West, It's a Woman's Intuition, Plus-, (March 1947), Vol. 98, No. 3, pp. 81-83. 18. Anonymous, Postwar Ironing Temperatures, Good Housekeep ing Institute, (1945), pp. 5, 10. 19. a). Arthur E. Fitzgerald, Basic Electrical Engineering, (:h:145), pp. 268, 269. 21. Norman, Ault, and Zarobsky, Fundamentals of Machine Design, (1938), pp. 13, 21 , 359-61, 401-4. 22. Anonymous, Celoron Silent Gears, Continental Diamond Fibre Company, pp. 3, 4. 23. Ovid W. Eshbach, Handbook of Engineering Fundamentals, (1936), pp. 5-22, 5-50.  SPRING RETAINER OILITE TYPE BUSHING COIL SPRING PHENOLIG HANDLE OIL SEAL GEAR SHAFTS — CAST IN AS INSERTS NEOPRENE OIL SEAL DIE CAST — ALUMINUM — GEAR COVER STEEL CLUTCH HALF @@ OQOOO@EOEGQD OO © OOO | ——~_— [jt —i) —— RUBBER CLUTCH HALF pe at TTT O PHENOLIC PRESS CONTROL U KNOB r| MOTOR zy | | FELT PAD tay 4 a F—F FULL SCALE = | RUFFLE SHOE COVER f NI LO) I PIANO WIRE LY rr STEEL EYELET ‘| LM KI I STEEL INSERT Mm > “Eos | ~ RUFFLE SHOE ELECTRIC __| | SUPPLY GA @ f 7 F U — Jy NR ~ M @) / PARTING LINE ‘} ; Q& vA if = Z AL 7 vaGs f. a) AS AWWHYL PY | Pa nt SS B-—B GEAR HOUSING — ALUMINUM DIE CASTING LS TLL OL LL LL L£ a a ea OE Se XQ | So ™ Wes iy \ dl ff L/ Nas x \ ga Nt KC Y WY | \ p SEF SON ~ >a ’z>S ce LZ xX a aa SEEK ena [OL a D—D RUFFLE SHOE COVER ASSEMBLY FIGURE 23 GEAR HOUSING 8 ROLL ASSEMBLY HALF SCALE =e SIDE ELEVATION QUARTER 24.5 — SCALE B-B QUARTER SCALE |——— COUNTERBALANCING SPRING y——l0 V2 X 2 x 067 REINFORCEMENT SEE DETAIL L _ A= Rh ‘ r aoe Lo. Kamel iT, 1 a . 1 i 1 1 i H - 33 18 7 7 vanmpenn RUBBER BEAD BOLT PLATE NUT ATA F-F E-E D-D [ " _ ' KNEE CONTROL FOR CAM = PLATE | RUFFLE SHOE COVER | [r] ' | 1 4 | Ir | TOGGLE a r | | | as Af c 1/4— 28 MACHINE SCREWS po = \ j 7“ a ar a ar sl | ao Pi Ll 1 =f “% Bape k -{-e Ly ! a — +h {e) J J BOTTOM VIEW OF TABLE J—Jd BELL CRANK FIGURE» 24. TABLE AND CABINET CHROME PLATED BEAD LIGHT GRAY TE SWITCH FACE GREY SWITCH BUTTON RED INDICATOR LIGHTS WHITE BAKED ENAMEL TABLE TOP c—c CONTROL PANEL ASSEMBLY HALF SCALE UNLESS OTHERWISE INDICATED HINGE aA DETAIL L LARGE ELEMENT SMALL ELEMENT MOTOR SW. COMPLETE WIRING DIAGRAM +— MAIN — K SHOE ELECTRIC SUPPLY 1—— 18 GAUGE j<—.080 BOX SECTION T= THERMOSTAT G+ COLD POSITION OF THERMOSTAT H=HOT POSITION OF THERMOSTAT