US2184261A - Stretchable leather shoe - Google Patents

Description

Dec. 19, 1939. A. vAMos 2,184,261

STRETCHABLE LEATHER SHOE Filed OC'b. 14, 1958 INVENTOR.

ATTORNEY Patented Dec. 19, 1939 'UNITED STATE-s PATENT OFFICE s'rRE'rcHABLE LEATHER suon Alfred Vamos, Brooklyn, N. Y., assignor, by mesne assignments, to United States Rubber Company, New- Jersey York,l N. Y., a corporation of New Application October 14, 1938, Serial No. 234,862

3 Claims.

taneously returning to or nearly to' their original 5 dimensions or are devoid of this property.

It has been proposed heretofore to secure a thin strip of leather to a strip of elastic webbing to form a leather covered elastic strip suitablefor use as a belt-worn to support the trousers, but in `such construction the wrinkles or lines formed transversely of the leather by the contraction of the elastic webbing are not particularly objectionable.

. It has also been proposed heretofore to employ various types of .elastic webbing and gores in shoes to make them elastic, but the material which has been universally used for many years in making most types of shoes is leather, and so far as I am aware, it is broadly new to form the upper portion of a shoe of leather that is adapted to stretch and contract with the foot movement,

`the same comprising a at sheet of shoe upper leather that has a substantial stretch and to which is adhesively secured an elastic sheet adaptedto. hold the leather normally in the contracted condition.

The requirements of this stretchable plied material consisting of stretchable leather having an elastic backing, in orderV to meet the demands of 40 the shoe trade are exacting. One such requirement is that ths'material shall lie fiat and smooth and be capable of stretching repeatedly in the shoe throughout a substantial. range without causing any appreciable change in the appearance 45 of the leather. Another requirement is that the leather be so firmly secured to the elastic backing that .it will remain free from puckers and wrinkles throughout the life of .the shoe. Another requirement is that this leather material be indistinguishabe or practically indistinguishable in appearance from the non-stretchable leather forming the rest of the shoe upper. A further requirement is that this stretchable material be sufficiently durable to retain its original stretch characteristic throughout the life of the vshoe in which it is embodied. A still further requirement is that the elastic modulus of this combined leather and backing be such that it will stretch with the foot movement and contract with suicient force to embrace the foot snugly and conformably without exerting sumcient pressure upon the foot to be painful even l when the shoe is worn continuouslyl for many hours.

In addition to the above it is highly desirable that this stretchable plied material be suiciently permeable to permit air to pass therethrough to thereby improve the foot Ventilating properties of the shoe. It is also desirable that this plied material be so constructed that it Will -lay at and smooth in the plied sheet without tending to curl up .or cause the leather to look different at its outer face from ordinary shoe upper leather.

This stretchable plied material may have the width of the entire skin from which the leather is secured and, the leather employed inthe stretchable portion of a shoe maybe obtained from the same pig, kid, calf or other sknsused heretofore to form shoe upper leather. Care however should be taken to finish the leather for the present invention so that it will retain or have imparted thereto much 'of the stretch of the original green skin. This may be accomplished by being careful not to stretch the skin duringv the tanning'and calendering operations and by imparting to the same a relatively soft pliable finish so that it will have an easy and substantial stretch. To this end the skins may be calendered less or underlighter pressure than was customary heretofore in making shoe upper leather. This desired stretch may also be im-l parted to the finished shoe leather by the treatment described in the above `mentioned application.

A primary feature of the present invention resides in a leather shoe having the entire upper thereof or a substantial portion thereof formed of the above described stretchable elastic backed leatherso that the shoe will stretch and contract with the foot movement.

A shoe constructed as herein contemplated is much more comfortable to the foot 'than the leather shoes available heretofore, and it ts the foot better in that the present shoe is free to stretchand contract to conform to the particular shape of the foot of the wearer. Furthermore the stretch-0f the `foot receiving opening of the present shoe makes it now practical to construct shoes that have much higher uppers than the ordinarypump without requiring the use of fastening means, since the stretch of the shoe will permit the insertion of the foot therein. Again the stretch characteristic of the present shoe causes it to cling to the foot much better than the ordinary leather shoe. This is particularly noticeable in pumps for it is now possible to make a pump which fits the foot with sufficient snugness to prevent it from' sliding up and down at the heel without binding uncomfortably across the top of the foot.

Another feature of the present invention reu sides in a leather shoe such as herein contemplated wherein the elastic and non-elastic portions thereof are or may be undistinguishable in appearance, and still a further feature resides in a shoe suchas herein contemplated wherein the elastic portions thereof affords the foot better ventilation than the non-elastic portions, and also better ventilation than theordinary leather shoes.

Still another feature of the present invention resides in the particular arrangement of this material in the shoe in respect to the clreetion of stretch of this material therein.

In developing the shoe of the present invention it became necessary to depart radically from the long established practice of lasting leather shoes, for heretofore in lasting shoes the shoemaker-has been careful to pull the shoe upper tightly over the last so as to remove all stretch and thereby prevent the shoe from stretching out of shape when in use. In constructing the shoe of the present invention special care must be exercised while lasting the same not to stretch the shoe more than a slight-amount so that it will have the desired elastic properties when Fig. 1, the leather of this plied sheet being partly rolled back.

Fig. 4 is a plan view showing the reverse side of the vamp and two quarters cut from Fig. 3;

Fig; 5 is a vertical sectional view through the plied material showing the fabric skived from the leather adjacent one edge thereof preparatory to finishing the upper edge of this material;

Fig. 6 is a sectional view taken on the line 6 6 of Fig. 1 showing the step of Fig. 5 carried forward to provide the upper edge of the shoe with a smooth nished edge; and

Fig. '7 isy a side elevation of a Womans shoe formed partly of stretchable and partly of nonstretchable leather.

In carrying out the present invention, it is important to use shoe upper leather, that is leather which has the strength and durability of the shoe upper leather employedl heretofore but which has in addition thereto the desired amount of stretch. The softer glove leather stock is not suiliciently tough and durable to give satisfactory service and wear in shoes when backed with an elastic sheet as herein contemplated.

When the stretchable and contractable plied material herein contemplated is to be embodied in shoes it is important that its elastic modulus be sufciently low to cause the pliedl material to stretch with the foot movement, otherwise the advantages herein contemplated in a shoe made of such material would be lost. It has been found in practice that a shoe upper constructed of this plied material may be somewhat thinner than the ordinary shoe upper as constructed heretofore, since the backing material adhesively secured to the inner face of the leather makes it unnecessary to use any other form of lining in the shoe.

In manufacturing this stretchable plied material for use in shoes the stretch employed may be from 10% to 50% depending upon the type of shoe and location of the plied material therein, and this stretch can be secured without causing the leather to wrinkle or pucker or otherwise show any appreciable change in its appearance throughout this range of stretch. The stretch of this plied material desired in most shoes is about 20% lto 25%, but as little as 10% stretch in the plied material may be sufficient when the entire upper portions of the shoe surrounding the foot receiving opening is made of this material for' with such an arrangement a 10% stretch in the plied material will permit the throat of the shoe to stretch a quarter of an inch or more which may be all that is desired.

When I rst became interested in the present invention I found it impossible to secure from the tanners shoe upper leather having the required amount of easy stretch, therefore I developed the treatment described in the above mentioned application to increase the range and ease of stretch of the shoe upper leather as purchased from the tanner. More recently the tanners have made an eifort to supply my requirements for a stretchable shoe upper leather and I am now able to buy from them such a leather having a 25% or more easy stretch, this making unnecessary in many cases the treatment described in the above mentioned application.

In carrying out the present invention, the stretchable leather as received from the tanner is first preferably skived to give it a uniform thickness, and it may be skived thinner than the leather commonly used heretofore in shoe uppers because the elastic backing sheet reinforces and strengthens the thin leather sheet. The skiving however should not be carried to such an extent that it produces an excessively thin leather sheet that will not stand up or give good service in a shoe. In most cases this skived leather should not be less than 1454 of an inch thick.

When it is not necessary to skive the leather skin to reduce its thickness, lit may be desirable to roughen that face of the skin to which the adhesive is to be applied, with sandpaper or other roughening means, in order that the adhesive may more firmly grip this surface of the leather. The adhesive binder may be applied to either the flesh side or the grain side of the leather depending upon which face of the leather is to be exposed in the finished shoe but in either case the face should be roughened. When a suede leather is used having the flesh face finished and exposed at the outer face of the shoe the elastic backing is applied to the previously roughened grain face.

After a leather skin has been acquired from the tanner having a desired range of stretch and sufficiently low elastic modulus, or has been treated by the method described in the above application toY impart the desired easy stretch thereto and has had the face to which the adhesive is 'to be applied either skived or roughened, the adaisaaei o hesive binder maybe applied. l

The adhesive' used is preferably a latex ade 'hesive which will give a firm bond without needing to be' vulcanized and the quickest and most satisfactory way yet devised for applying this latex-adhesive is by a spraying operation. One

important advantage obtained by spraying the latex upon the leather is thata good bond can be secured without decreasing the permeability of the. leather to air, This latex adhesive is preferably sprayed upon the leather skin while it rests upon a supporting surface in a fiat but unstretched condition.

After the stretchable skin has had the latex adhesiveapplied to one face thereof it may them be provided with theelastic backing.

Various elastic sheet materials which will maintain their elastic properties throughout the life of the shoe may be used as a backing-for the above described leather sheet to hold the `same normally in its contracted condition, but

the-material preferably used is a sheet of lfine woven elastic fabric such as elastic batiste. 'The backing material preferably has a longer stretch than the leather so as not to interfere with the 1 stretch ofthe leather and the contractive force may be as strong as needed for its use in the shoe. It isoimportant that this backing material be carefully constructed so that the tension and stretch characteristics of thefsame shall be uniform throughout that area which backs any one skin, because if local variation exists in the ten- 'sion ofthe backing fabric it will tend to pucker l or distort the skin to which it is secured.

This backing fabric should have a latex adhesivesprayed uponone face thereof similarly to the manner in which this adhesive is applied to the leather skin, and here again it is desirable that the latex be so applied that it will not appreciably interfere with the passage of air '5 through the fabric. f

- in'an unstretched condition. yIt is found desirablewhile'uniting thesetwo. sheets or shortly thereafter to pass them between calender rolls to increase the bond therebetween and force out any air which might be trapped. The stretchable plied material thus formed may then be placed in a` at condition in a stack with other similarly formed sheets which, should be separated from each other`by sheets of cardboard placed between the backed leather sheets. They should be allowed to remain in this stack for about 12 hours while the moisture of the latex adhesive escapes or dries out. vThe materialis then ready to be embodied in shoes. l 'l It is found that the moisture of the latex binder has a tendency to swell the textilebers forming the backing sheet. Therefore, 'to reduce this `swelling tendency, it has been found desirable to treat the face of the backing fabric to .which the latex is toy be applied witha light coating of any 'suitable water-repellant substance Vwhich will lessen the tendency of the fibers l of this fabric to absorb moisture fromthe adhesive. One well known water repellantV substance which vmay be used 'consists-of water containing about 2% emulsion of soap 'and carnauba wax.A

Most leather skins will stretch. more readily in the direction around the animal fromwhich the portions thereof.

skin was taken than longitudinally of such animal, therefore the backing material which is preferably a one-way stretch fabric is so ap'pliedl to the skin that its direction of stretch will correspOnd with that of the maximum stretch of the skin. y

The treatment involved in imparting the desired amount ,of stretch to the Vleather skin andl in adhesivelyl securing the elastic backing thereto need not in any way change the appearance of the 'outer face of the leather, and the total thickness of the two-ply material thus formed may be less than %4'of an inch. The backed stretchable leather such as herein contemplated may have a stretch of 50% or more but a much lower stretch is suicient in most shoes to impart the e bodying the material therein. It` will be understood, however, that this material may be employed in various types of shoes and in various 'Referring to the drawing the stretchable plied material Ill is formed of a sheet ofshoe upper' leathe; IIwhich has been treated bythe tanner or otherwise,l to give it a low elastic modular and the desired amount of stretch, and to one face of this sheet of leather is adhesively secured the elastic backing sheet I2T A perforated rubber sheet may be employed as the backinggsheet but it is preferable to use a fine woven elastic fabric having a fone-waystretch and having the elastic yarn I3 introduced therein either as warp or weft. These elastic yarns are preferably constructed in accordance with the Adamson Patent No. 1,822,847 for elastic yarn. Such a woven elastic backing sheet makes an excellent lining for the portion of the shoe in which the stretchable leather is embodied and makes the use of any other lining in this area unnecessary.

The sheets II and I2 are secured together by an adhesive binder 'I4 which is necessarily elastic to accommodate the stretch of the plied material and this adhesive binder is preferably-the latexv binder above described which is so applied to the leather and fabric that it will not appreciably l interfere with the passage of air through the stretchable plied material. By using a latex adhesive compound which is not too fluid and by employing a suciently small amount it is practrate the direction in which the elastic yarns I3 extend in each. f e

The shoe illustrated in Figs. 1 and 2 differs from the ordinary oxford in that the entire vamp area ofthe shoe is formed of the-stretchable vamp I5` which, is placed in the shoe so that the elastic yarns extend transversely of the foot to -impart 'to this part of the shoe a stretch and contractive force'. crosswise of ythefoot as indicated by thearrow a.v The quarters I 6 and I1,

it`will b e noted, are so cut from the sheet I 0' that the elastic yarns I3 extend in a diagonal direction. The arrangement is such that the portion of .each quarter lying in the vicinity of the throat stretches in the direction indicated by the arrow b whereas the portion of the quarter lying at each side of the foot stretches diagonally of the material. The shoe of Figs. 1 and 2 may be built upon a lastas usual but it is desirable to s ecure a binding tape temporarily to certain portions of the inner face of the shoe material during the lasting operation to prevent theupper from stretching too much at this time.

'The shoe may or may not have the usual box toe as there is no particular point to having lthe extreme toe of the shoe stretchable. The box toe is omitted in the construction shown. The vamp I5 as shown is secured to the forward portion of the quarters lI6 and I'I by the usual seam I8 and these quarters are secured together at the rear of the shoe along the vertical seam I9. The shoe is shown as having the usual sole 2|) and heel 2| and the forward ends of the quarters I6 and I'I may be provided with the usual eyelets to receive the shoe lacing 22, and the shoe is provided with a tongue 23. The upper edge of the shoe around the foot receiving opening may be variously finished to provide a smooth rounded stretchable edge and in the construction shown the finish is secured by skiving away the woven fabric I2 near the upper edge of the shoe 'so as to expose the inner face of the leather II as shown in Fig. 5. 'Ihis exposed portion of the leather is then folded over upon the skived fabric I2 as shown in Fig. 6 and it may be secured in this folded condition by an adhesive and also by thezig-zag stitching 24 to thereby provide a smooth rounded upper edge 25 around the foot receiving opening that will stretch. y

The construction of the shoe illustrated in Figs.- l and 2 is such that the entire shoe upper is adapted to stretch and contract to accommodate the foot movements and to conform snugly but comfortably to the contour of the foot. 'I'his is just the reverse to the ordinary leather shoe as constructed heretofore wherein care is taken to prevent the shoe from stretching when worn.

In the present shoe the entire forepart or vamp area is so constructed that it will stretch transversely to relieve the pressure upon the toes and sensitive forepart of the foot whereas the upwardly converging portions of the quarter in the vicinity of the throat of the shoe will exert a yielding but comfortable pressure about the foot to thereby yieldingly support the arch of the foot and prevent `the foot from crowding forward in the shoe, land the longitudinal stretch of the/quarters at the sides of the foot causes the shoe to t snugly at the h eeland around the foot receiving opening. Such a shoe is extremely strong and durable and is capable of wearing as long and probably longer than the ordinary nonelastic leather shoe and is far more comfortable than the ordinary shoe, due to thefact that its stretch characteristics cause it to conform accurately to the contour of the foot and to yield to the foot movement.

Referring now to the modified construction Shown in Fig. 7 wherein is illustrated a shoe in which the rear portion in the vicinity of the counter has the usual non-elastic construction and the forepart is constructed of the stretchable ply material I Il to therebyfimprove the fit of the shoe, and cause the same to stretch suflicently to permit the insertion of the foot in the shoe and its removal therefrom withoutv requiring the use of any form of fastening means even though the shoe illustrated is considerably higher in the throat area than the ordinary step-in type of shoe. v

The shoe of Fig. 7 may have the usual sole 26 and heel 21 but the entire forepart at each side of the shoe is formed of the stretchable laminated leather fabric l0. The heel embracing or counter portion 28, toe 29 and a narrow strip 30 extending upwardly along the throatrof `the shoe are formed of the usual non-stretchable leather. f The fabric I 0 is preferably so placed in the shoe that the elastic yarns I3 extend approximately'parallel to the longitudinal axis of the shoe. This construction permits the shoe to .stretch in the throat area from its normal posifitting shoe unless the shoe is custom made, due

to the fact that the ordinary' shoe is made upon a standard last and nearly every ones foot differs to some extent from the contour of the standard last of the size shoe he wears. As a result of the present invention it is not necessary to have a shoe custom made to secure a perfect fit since the` stretch properties of the present shoe will cause it to mold or conform accurately to the foot ofthe wearer.

It is found that a shoe constructed as herein contemplated affords the foot better ventilation than the ordinary leather shoe, since'in the present construction the permeability of the stretchable plied material I0 is very nearly the same as the permeability of the leather sheet II before the latex adhesive I4 is sprayed thereupon. This has been established by experiments in which pieces of the leather II which had not had the latex applied thereto were fastened in a Having thus described my invention what I' claim and desire to prot'ect byLetters Patent is:

1. A shoe of the type described having the It was found upper thereof formed in part of ordinary shoe upper leather and in part of an elastic plied inaterial at the instep, said plied material consisting of an outer sheet of durable leather having a smooth unwrinkled surface and a substantial and easy stretch and being provided with an elastic backing sheet adhesively secured thereto and coextensive therewith so that both sheets are free from stress in the relaxed plied material, and arranged to provide the shoe with an elastic area of said material at the instep that is capable of stretching and contracting with the longitudinal foot movement and of giving good wear in the shoe.

2. A shoe of the type described having the upper thereof formed with an elastic plied material in the area oi' the instep, said plied material consisting oi an outer sheet oi durable leather at least Vu of an inch thick having a smooth unwrinkled surface and a substantial and easy stretchand being provided with an elastic backing sheet adhesively secured thereto and coextensive therewith so that both sheets are free from stress in the relaxed plied material, and' arranged to provide the shoe with an elastic area of said material at the instep that is capable of stretchingl land contracting with the longi-` upper leather and in part of an. elastic plied material at the instep, the outer face of the two being matched so that they are practically indistinguishable in appearance, said plied material consisting of an outer sheet of durable leather having a smooth unwrinkled surface and a sub- 'stantial and easy stretch and being provided with an elastic backing sheet adhesively secured thereto and coextensive therewith so that both sheets are free from stressy in the relaxed plied material, and arranged to providethe shoe with an elastic area 'of said material at the instep that is capable of stretching and contracting with the longitudinal foot movement and of giving as good wear as said ordinary shoe 'upper leather.

ALFRED VAMOS.

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