US2321088A - Nonslip leather sole - Google Patents

Description

Jime8, 1943 c, JOHNSON 2,321,088

NON-SLIP LEATHER SOLE Filed March 5, 1942 ?atented .i'nne i 2,321,988. NONSLIP martian some Charlotte T. Johnson, Chicago, ill.

Application March 5, 1942, Serial No. 433,413

2 Claims. (01. 36-59) The non-slip leather sole of my present inven tion is particularly advantageous when used on infants shoes, but its use is not to be regarded as necessarily so limited.

One of the principal objects of my inventionis to provide leather shoe soles with integral walkway grippers that are particularly effective in preventing forward slippa e of the feet fromunder a wearer of shoes equipped with such soles-this being a very important consideration when the soles are applied to infants shoes. 7

Another object of my invention is to provide a relatively thin leather shoe sole with effective walkway grippers which cause no discomfort to a shoewearers foot bearing either directly, or through a thin stocking, upon the upper surface of the sole structure.-

Another object of my invention is to provide a relatively thin leather out-sole with walkway grippers which cushion the sole and thus render it more comfortable to wear than it would be if such grippers were not present.

Another object of my invention is to provide a leather shoe sole with walkway grippers in such manner that the ability of the sole naturally to flex with a shoe wearer's foot is enhanced, rather than diminished, as would be the case were the grippers in the form of hobs, cleats, pads or plates embedded in or attached to the sole.

And still another object of my invention is to provide a novel method of making a practical non-slip leather out-sole, which may be carried out with the aid of inexpensive and economically operable equipment.

These and other features, objects and advantages of my invention will appear from the following description, wherein reference is made to the accompanying sheet of drawings. in which Fig. l is a side elevational view of an infants shoe embodying the sole of the present invention, drawn on an enlarged scale to emphasize the predominant features of the invention;

Fig. 2 is a bottom plan viewof such sole;

Fig. 3 is a greatly enlarged sectional detail view taken in the plane of line 3-3 of Fig. 2 and shows more or less schematically the results.

of compression of the leather in the formation of the non-slip walkway grippers;

Fig. 4 is a diagrammatic perspective illustrating the principal elements of the equipment wherewith I prefer to provide my improved shoe soles with their walkway grippers; and

Fig. 5 is a schematic diagram illustratinghow a plurality of leather out-sole-receiving plates or trays may be mounted on an endless carrier passing under a vertically reciprocating die which acts progressively amultiplicity of times upon each leather out-sole passing therebeneath.

Having more particular reference to the drawing, an infant's shoe it embodying the features of the invention, has been selected as the illustrated example because of the perhaps greater advantages resulting from the use of my invention in shoes of this class as compared with other classes of footwear. Due to the relative y undeveloped condition of their muscles, infants as a class are notoriously unsteady on their feet, and therefore any slipping of the walkwayengaging surface of the shoe soles during walking has a far greater unsteadying influence on infants than upon more mature individuals,

It should be remembered, however, that although infants shoes ofier a large and very important field for use for the invention, the improved results of the invention are of very substantial value when applied to other types of shoe. For instance, old folks will find grateful relief from worry over the danger of falling due to slipping where their shoes are provided with non-slip out-soles embodying thepresent invention. Certain sport shoes, such as bowlin shoes, are improved by the use of my invention.

In fact, the novel non-slip feature of the invention is advantageously applicable to all shoes which employ a leather out-sole, and which should be as free as practicable from danger of slipping on the walkway, without the use bf hobs, cleats, pads, spike plates, or the like.

The shoe Ill includes the usual o preferred features of shoe construction such as an upper li, a welt it, a heel-wedge or insert l3, and a leather out-sole is which is secured to the welt I? by stitching is. Since this is an infant's shoe, the walkway face of the sole 14 covers both the ball and the heel portions of the shoe in a commonplane. g

According to the invention, the out-sole .H is cut to shape in a single piece from suitable sole leather and has the bottom or walkwayengaging surface thereof formed with an arrangement of linear promin'ences providing nonengaging surface.

slip treads or grippers l5. As shown in Figs.

1 and '2, the grippers ii are of uniform sibe and shape and uniformly cover the entire walkway- Each of the grippers I! extend entirely across the sole from edge to edge and lies at right angles to the direction of the main slippage to be prevented, that is, longitudinally of the shoe. In cross-section, each gripper preferably has a substantially ratchet-tooth shape, that is, is formed with two faces angularly related to each other and respectively angularly related to the original face plane, identified by P in Fig. 3, of the leather surface in which they are formed. One of such gripper surfaces,'identified by the numeral i6, extends at a quite abrupt angle.

1 preferably about ninety degrees, to the plane P,

while the other surface, identified by the numeral l7, extends at a relatively gently sloping angle, of preferably between five to twenty degrees relative to such plane. faces i6 and ii join at a relatively sharp prominence or ridge edge I8.

In the preferred arrangement, the gently sloping surface it of each gripper extends from v the edge i8 to convergence with the foot of the arrangements to meet special preferences or requirements and conditions.

In a preferred method of providing the leather out-sole i l with the grippers i5, the walkway face of the sole leather is subjected to shallow shearing along spaced lines to provide the abrupt .surfaces it, and also to compression and compacting in limited elongated areas adjoining the shear lines to depress the leather and form the slanting surfaces ll of the grippers. All of this The gripper suris preferably done after the sole leather has been at least rough-cut into the desired shoe-sole shape but before the sole has been attached to the shoe.

At the time the sole leather is subjected to such shearing and compression, it may be dry or moistened with a suitable liquid, warm or cold, and the pressure may be accompanied by heat, all depending upon the precise results de sired as to the prominence and permanence of the grippers and also depending upon the kind and quality of leather being used. Moreover, the grippers [5 may be formed either on the smooth or hair side of the leather, or on the flesh or rough side of the leather, depending upon the use or eifect intended. Before or after the gripper-producing treatment, the walkwayengaging face of the sole may, if desired, be treated with a suitable coating or, impregnating substance.

In carrying out the method, care should usually be exercised to keep the back face of the leather, that is, the face opposite the walkwayengaging face of the sole H, in as nearly as practicable its original fiat state, especially where such fiat surface is itself to provide the insole surface of the shoe or is to be covered with only a thin and not self-sustaining insole. For this purpose, the sole leather should be backed up with a smooth and unyielding surface when the compacting pressure is applied to the walkway surface in forming the grippers IS.

The compacting pressure is applied with greatest force immediately in front of the abrupt surface shoulder l6 of the grippers and to progressively diminishing extent up the slopes of the surfaces l1. As indicated at C in Fig. 3, this causes the fibers of the leather in the region immediately adjacent the converging foot edges of the gripper surfaces I 6 and I1 and inwardly of the base areas of the sloping surfaces H, to be most compacted and dense, with corresponding decrease in density as the gripper edges l8 are approached. The outer edge zones of the grippers are uncompacted. Since the compression force is then concentrated along spaced lines, there appears to be a slight displacement of the leather fibers toward and into the uncompressed edge zones of the grippers, resulting in a slight pulling up and outward extension of the edges l8 beyond the original face plane P of the leather. This has the advantage of softening the grippers l5 and endowing them with a certain springiness, which cushions the.

sole l4 and gives, the wearer greater walking comfort.

The compacted zones C afford substantial bridges across the gaps or hollows between the grippers l5 and act to sustain and keep in a uniform plane the back face of the sole l4 so that the grippers will not be felt by the wearer's foot.

By preference, each of the grippers i5 is formed separately and successively, in an order starting the formation of the grippers at the toe end of the leather sole l4 and completing at or adjacent the heel end. One way in which I accomplish this is by advancing the sole step by step, by gripper width increments, between forming means such as the equipment shown schematically in Figs. 4 and 5. This comprises a substantially non-bendable metal plate or tray 20 for supporting the sole under a die 2| which is carried by a ram 22 for vertical reciprocation into and out of pressure engagement with the upwardly facing walkway-engaging surface of the sole in timed relation to gripper-width incremental advancing movements of the tray 20.

The leather sole I 4 is held centered upon the tray 20 within the confines of a shallow fiat bottom depression 23 having the same outline as the sole and which is of a uniform depth only a small fraction as deep as the thickness of the leather. Thus, when the sole'is fully received in the depression 23, the major thickness of the leather projects above the fiat upper surface of the tray sufficiently to receive fully therein a combined shear member and pressure rib 24 on the die 2|, while yet affording ample clearance between the edge of the pressure rib and the surface of the tray at the bottom of the pressure stroke, even when the die is operating upon the narrower parts of the sole.

The pressure rib 24 is, of course, long enough to extend entirely across the sole I 4 and is the substantial counterpart of one of the grippers surface which, being relatively yieldable, will to some extent resist the cutting and tend to give before the oncoming die. However, the unbroken surface of the leather has a substantial surface tension (the tenacity of which depends upon th kind or lack of finish upon the surface) which counteracts the yielding and allows the edge 25 to penetrate the surface and shear down cleanly into the leather along the abrupt surface of the rib to form one of the abrupt gripper surfaces [6. At the same time the sloping surface of the pressure rib 24 compresses the leather therebeneath to form the sloping surface ll of another of the grippers l5. Thus, by advancing the leather sole as shown in Fig. 4, so that the rib edge 25 always attacks an unbroken surface area of the leather, there is assurance of a clean severance of the abrupt gripper faces [6. coincidentally, there is, of course, no surface ten- 7 sion of the leather at the edge I 8 of the gripper being formed which might tend to resist the slight displacement and puffing up of the edge zone of the gripper as the sloping surface of the pressure rib bears down against the long, narrow area of leather therebeneath and just in advance of the previously cut abrupt gripper surface It. The pressure stroke of the die is adjusted to stop short of compression of the edge ll! of the gripper.

In order to operate the apparatus continuously, a preferred arrangement consists in having a continuous series of the trays ZU-traveling under the die 2| so that the die can operate on successive leather soles substantially without interruption.

As shown in Fig. 5, the trays are carried in endlievedof surface tension tending to retain the' face taut, such face is not subject to wearing down left shoe soles so that during a given period of operation an equal number of right and left soles i can be treated for the desired number of complete to a slick finish at least in those areas receiving the greatest pressure from the foot in walking. This eliminates a condition which increases the tendency toward slipping with ordinary leather soles, and particularly the soles of infants shoes.

Although a leather shoe sole treated according to my invention is more flexible in the longitudinal or walking direction, there is no weakening of the leather in a transversedirection but actually a strengthening thereof due to the compacting of the fibers along unbroken transverse lines. Thefefore the wearer's foot is firmly supported against unnatural inor out-turning or twisting but is supported and guided in a normal forward direction. This is of particular orthopedic value for infants since it counteracts abnormal tendencies such as toeing -out or toeing-in in walking, but guides and controls proper walking so as to assist in th proper development of the foot muscles.

While I have illustrated and described a preferred embodiment of my invention, many modiflcations' may be made without departing from the spirit of the inventiomand I do not wish to be limited to the precise details set forth, but desire to avail myself'of all changes within the scope of the appended claims. r

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

- 1. A leather outsole for a shoe having on the walkway-engaging face thereof a' plurality of non-slipping grippers formed integrally with and derived directly from the leather itself, each of V the grippers comprising" a pair of divergently details of the mechanism as are not shown-are of conventional construction and operation and can readily besupplied by any mechanic.

It is noteworthy that a wearer of a shoe equipped with my improved leather sole is not conscious of any difference in the sole aside from its non-slip characteristics, and that it is possessed of unusual walking flexibility especially when new. The grippers l5 being relatively shallow, narrow, closely spaced, and cushioned, are not perceptible to the wearer's footthat is, there is no corrugated sensation to the foot. If there is any difference in sensation it is rather that of an unusual softness or cushioning arising both from the greater walking flexibility of the sole way contacting portions of the grippers I5 is related surfaces, one of said surfaces comprising the contiguous original surface area of the walk,-

way-engaging face of the sole, the other of said gripper surfaces comprising a cleanly sheared raw leather plane area extending angularly'in wardly from the original walkway-engaging face plane and facing toward the toe end of the sole, the said one surface of each of the grippers slanting heelward inwardly-toward the-base of the adjoining sheared raw leather surface of the heelward adjacent gripper to expose such raw leather surface for non-slip gripping action in the use of the sole, the material of each gripper inwardly of the base region of said one surface and the contiguous unsheared portion of the sole leather being permanently compacted to substantially greater density than the normal density of the leather, and the leather contiguous to the ridge CHARLOTTE 'r. JOHNSON.

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