US2100278A - Reinforced last for boots and shoes - Google Patents

Description

Nov. 23, 1937. w, HELD 2,100,278

REINFORCED LAST FOR BOOTS AND SHOES Filed July 29, 1936 11901364 fi 'tleld w 22 a0" 22/ 541 FF wQ M Patented Nov. 23, 1937 UNITED STATES PATENT OFFlE REINFORCED LAST FOR BOOTS AND SHOES Application July 29, 1936, Serial No. 93,163

6 Claims.

This invention relates to lasts and more especially to wooden lasts used in the manufacture of boots and shoes and provided with means for protecting the lasts when subjected to heavy pressure.

' Heretofore, it has been customary, in the manufacture of boots and shoes, to attach the heels to the shoes while the lasts, upon which the shoes have been lasted and supported during the making, still remain in the shoes. This is desirable be cause if the last is removed before the heeling operation, distortion of the shoe may result from that operation, which necessitates a relasting after the heel has been attached, which mate 15 rially increases the cost of production. In the heeling operation, however, the comb of the last is subjected to a very heavy pressure, which in time breaks it down and destroys the last.

Various attempts have been made to eliminate 20 this difiiculty by providing the comb of the last with protective cushions, which in most cases have included a layer of leather as a cushioning element. Such devices have not proved satisfactory, because in time the leather, due to the heavy 2'5 pressure, becomes solidified and loses its resiliency and no longer prevents the comb from disintegrating under the strains imposed on it. Furthermore, the pressure exerted by heeling, nailing, and other machines has been much increased in 30 the newer types of these machines and the old forms of cushioning devices have been found to be entirely inadequate because of their short lives.

The main object of my invention is the elimina- 35 tion of the foregoing difiiculties by providing the top or comb of the heel portion of the last with a protective cushion, which is adapted to receive and absorb the pressure exerted by heeling and other machines, and, thereby, protect the last 40 from being injured in that operation, and which is durable.

Another object of the invention is the provision of means for fastening the cushion to the last which permits the cushion to be compressed with- 45 out disturbing or loosening the fastening means.

Other objects will be more specifically pointed out and described hereinafter.

In its preferred form, my invention contemplates a wooden last having its comb portion reinforced with a protective cushion comprising a pair of layers or plates in superposed relation,

the outer layer being of hard unyielding material adapted to receive the impact of the pressureexerting parts in a heeling or other machine,

55 and an inner layer of resilient compressible material adapted to absorb the pressure exerted in the machine to protect the comb of the last from injury. Since wooden lasts are subjected to long periods of use, it is important and necessary that the inner layer should be of a material 6- having a high degree of resistance for retaining its original form and shape and also sufiicient permanent resiliency for absorbing the pressure imposed upon the cushion. Unless the inner I layer has these characteristics, the comb of the 10 last will be broken down when the inner layer loses its resiliency, so that it can no longer absorb the pressure exerted by the heeling and other machines to which it is subjected in use.

My invention contemplates the provision of an inner layer or plate made of a rubber composition having a high degree of resistance combined with permanent resiliency. I have found that a rubber composition of approximately ninety-two percent. hardness will give the necessary resistance and yet leave sufficient resiliency to absorb all the pressures to which it may be subjected. The rubber composition is preferably anti-oxygen treated to prevent deterioration and should contain little or no carbon to avoid discoloring the last when it is subjected to the final polishing process. I have found that the use of a composition of this character for the inner layer of the cushion gives a permanent resistance and resiliency to this layer, so that the cushion will re tain its form and pressureabsorbing quality throughout the life of the last.

In the accompanying drawing illustrating the preferred embodiment of my invention, Figure l is a side elevation of a last provided with a cushioning device made in accordance therewith and mounted upon the jack of a heeling machine;

Fig. 2 is a central longitudinal sectional view of the heel portion of the last;

Fig. 3 is a top plan view of the same; and 0 Fig. 4 is a central longitudinal sectional View of the heel portion of a last having a cushioning device of modified construction.

Referring to the drawing, there is shown in Figure 1 a wooden last of ordinary hinged form, comprising a fore part I0 and a heel part l2 hinged together by a pin it. The last, however, may be of any form, and that shown is merely for the purpose of illustration.

The protective cushion of my invention is pref- 5o erably made in two parts, which are in the form of layers or plates l6 and I8 respectively, conforming in outline to the shape of the comb 20 of the heel portion of the last, to which the layers or plates are fastened in superposed relation by any suitable means. The outer layer or plate I 6 may be made of any hard material which is substantially non-compressible, such as a vulcanized fiber, and the inner layer or plate i8 is made of a material having a high degree of resistance combined with sufficient resiliency to absorb any pressure which may be imposed upon the cushion, and this material is preferably of rubber composition. I have found that a rubber composition of approximately ninety-two per cent. hardness has sufiicient resistance so that it will maintain its form and shape permanently and a resiliency sufficient to absorb the pressures imposed in use. The rubber composition is antioxygen treated to prevent deterioration and should be relatively free from carbon to prevent discoloration of the last when it is finally polished. I

The two layers or plates l6 and it may be fastened to the comb 2d of the last by any suitable means which will not interfere with the compression of the cushion under pressure, and one such means comprises a plurality of hardened drive screws 22 having smooth shanks and threaded ends. The outer layer it is provided in its outer face with small recesses 25 for housing the heads of the screws below said outer face to prevent projection of the heads therefrom. When the cushion is compressed, the threaded ends of the screws are embedded in the comb of the last, and their smooth shank portions which lie in the two layers permit movement of said layers thereon, without disturbing the fastening of said screws in said comb when the cushion is compressed. With fastening means of this character, all possibility of the cushion being held in a compressed condition by said means is eliminated.

The thickness of the cushion as a whole and the relative thicknesses of the two layers may be varied to some extent, but I have found that a cushion which is approximately three-eighths of an inchin thickness is adequate for absorbing the pressures now in vogue and will prevent a last from breaking down at the comb portion. Preferably, the inner layer of rubber composition is somewhat thicker than the outer fiber layer, and one proportion which I have found satisfactory is seven thirty-seconds of an inch for the inner layer and five thirty-seconds of an inch for the outer layer.

In Figure 4, there is shown a modified form of cushion which results from adding a third layer, preferably of hydrated sole leather, to the two layers of the preferred form. This third layer 26 is interposed between the layer 58 of rubber composition and the comb 2d of the last heel. The advantage of this form of cushion is that it can be made at a lower cost than the preferred form shown in Figure 2, since the thickness of the rubber composition layer 98, which is the mostexpensive element of the cushion, can be materially reduced. In-this form of cushion, the greater portion of the pressure imposed upon the cushion is absorbed by the intermediate layer of rubber composition and the remaining portion of said pressure, which is passed on to the inner layer of leather, may be readily absorbed thereby without causing that layer to lose its resiliency and to be warped out of shape after long use.

The heel portion I2 of the last is provided with a metallic thimble 28, arranged to receive the spindle 30 projecting upwardly from the block 32 of the jack 34 of a heeling or nailing machine. The thimble is fastened within the heel portion by a struck-out lug 36. Preferably, the thimble is provided with a flange 38 which is countersunk in the outer face of the outer layer it and serves as an additional means for holding the central portion of the cushion fast to the comb of the last.

When the last is mounted on the spindle, the outer layer of hard fibrous material is in engagement with the block and first receives the ressures involved in the heeling or other operation, which pressure, in the preferred form of invention, is transmitted to and absorbed by the inner layer of rubber composition. Because of the hard and unyielding character of the outer layer, the pressure is spread over the entire area of said layer and absorbed by the entire area of the rubber layer, so that all possibility of injury ends embedded in said comb portion and having smooth shank portions within said cushion for permitting compression of said cushion without disturbing the fastening of said screws in said comb.

2. A wooden last for boots or shoes having its comb portion provided with a protective cushion comprising an outer layer of vulcanized fibrous non-compressible material and an inner layer of relatively hard yet permanently resilient rubber composition, said cushion being fastened to said comb portion by a plurality of drive screws having threaded ends embedded in said comb portion and having smooth shank portions lying within said cushion for permitting compression of said cushion without disturbing the fastening of said screws in said comb, said outer layer being provided in its outer face with recesses for housing the heads of said screws below said outer face.

3. A wooden last for boots or shoes having its comb portion provided with a protective cushion comprising an outer layer of fibrous non-compressible material, an inner layer of hydrated leather and an intermediate layer of rubber composition of approximately ninety-two percent hardness, said cushion being fastened to said comb portion by a plurality of drive screws having threaded ends embedded in said comb portion and having those portions lying within said cushion smooth for permitting compression of said cushion without disturbing the fastening of said screws in said comb.

4. A wooden last for boots and shoes having its comb portion provided with a protective cushion comprising two superposed layers or plates of uniform thickness and approximately equal area, the outer layer or plate being of non-compressible material and the inner layer or plate being of permanently resilient, elastic and compressible material such as rubber composition of ninetytwo percent hardness, and means for fastening said layers or plates to the comb of said last, said means being anchored in said comb and being adapted to permit movement under pressure of said layers without disturbing the anchoring of said means.

5. A wooden last for boots and shoes having its comb portion provided with a protective cushion adapted for absorbing the blows of a heeling machine to prevent fracturing the last, said cushion comprising two layers or plates of uniform thickness in superposed relation, the outer layer or plate being of non-compressible material and the inner layer or plate of permanently resilient, elastic and compressible material, said compressible material being of sufficient hardness to absorb the pressure of said blows without substantial compression, and means for fastening said plates to the comb of said last adapted to permit movement of said plates under pressure without disturbing the fastening of said means in said comb.

6. A wooden last for boots or shoes having its comb portion provided with a protective cushion comprising an outer layer of non-compressible material and an inner layer of relatively hard yet permanently resilient rubber composition, both of said layers being of uniform thickness and of approximately the same area, a thimble mounted in said cushion and comb and having its outer end countersunk in said cushion and its lower portion fastened in said comb, the layers of said cushion being freely movable under pressure in relation to said thimble, and means anchored in said comb for fastening said cushion to said comb, said means being adapted for permitting movement of said layers under pressure without disturbing the anchoring of said means in said comb.

WALTER. P. FIELD.

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