US3562930A - Footwear - Google Patents

Abstract

FOOTWEAR SUCH AS SHOES WITH AN UPPER OF LEATHER OR SIMILAR MATERIAL AND A SOLE OF POROUS ELASTOMER HAS ACCORDING TO THE INVENTION A WELT OF HIGHLY COMPRESSIBLE ELESTOMERIC MATERIAL STITCHED TO THE LOWER MARGIN OF THE UPPER AND A SOLE OF PREFERABLY THE SAME POROUS ELASTOMER IS SECURED TO THE WELT AND UPPER. A THIN TREAD SOLE OF NONPOROUS MATERIAL MIGHT COVER THE OUTSIDE OF THE SOLE. PREFERABLY, THE WELT SURROUNDS THE SOLE ANT THE LATTER IS SECURED BOTH TO THE WELT AND TO THE TREAD SOLE.

Description

Feb. 16, 197 c. E. KAUFMAN FOOTWEAR Original Filed Jan. 14, 1966 United States Patent 3,562,930 FOOTWEAR Curt E. Kaufman, Waynesville, N.C., assignor to R0- Search Incorporated, Waynesville, N.C., a corporation of North Carolina Original application Jan. 14, 1966, Ser. No. 521,247, now Patent No. 3,473,178, dated Oct. 21, 1969. Divided and this application Jan. 27, 1969, Ser. No. 794,333 Int. Cl. A43b 00/00 U.S. Cl. 36-25 1 Claim ABSTRACT OF THE DISCLOSURE Footwear such as shoes with an upper of leather or similar material and a sole of porous elastomer has according to the invention a welt of highly compressible elastomeric material stitched to the lower margin of the upper and a sole of preferably the same porous elastomer is secured to the welt and upper. A thin tread sole of nonporous material might cover the outside of the sole. Preferably, the welt surrounds the sole and the latter is secured both to the welt and to the tread sole.

This application is a division of co-pending application Ser. No. 521,247, filed Jan. 14, 1966, now Pat. No. 3,473,178.

The invention refers to footwear such as shoes with an upper of leather and a sole of porous elastomer.

It is customary to manufacture such footwear by first pulling the lower margin of an upper of leather over a last to stretch and tighten the upper and securing the margin to a structural insole so that subsequently a prepared sole of porous elastomer can be cemented to the insole and the margin of the upper.

According to the invention, shoes with elastomer soles are improved by a more secure connection between upper and sole and by increased flexibility.

The invention is clarified hereafter in connection with the drawing which shows in FIG. 1 a cross section of the device used for the manufacture according to the invention, at the completion of the manufacturing cycle before the finished shoe is removed from the device. FIG. 2 shows in a larger scale a cross section through the toe and FIG. 3 a cross section through the heel of the shoe according to the invention. FIG. 4 shows a view, partially in section, of still another execution of the invention.

In the manufacture the upper 1 is prepared from pieces of leather. At the bottom margin 2 a welt 3 is fastened by the stitching 4. While the material for the welt heretofore was selected to be at least as strong as the material of the upper, i.e. stiff leather or solid rubber, the invention provides that the welting material consists of a highly compressible elastomeric material such as porous rubber preferably of the kind having closed cells. It has been found that while such material is strong enough to be stitched to the upper, it is at the same time highly compressible which is an essential feature in the process steps explained hereafter.

The so-prepared pre-welted upper is placed loosely on the last. A structural insole is eliminated. The welt and with it the lower margin of the upper are held in their approximate position temporarily by clamps or threads, not shown. Then the side frame 5 usually lengthwise divided in two parts, is placed adjacent to thebottom margin of the upper, but at a distance thereof. The clamps are then removed or the threads cut so that the welt can slip back until the outer rim lies flush against the inside wall of the side frame. Push rods 6 are provided to hold the side frame 5 in a suitable distance from the upper so that a contact between the side frame and the upper is completely eliminated. The bottom surface 9 of the welt and the top surface 10 of the previously prepared sole 11 are covered by a heat-setting cement before the sole 11 is placed into the corresponding cavity which is formed by the last 21, the side frame 5 and a bottom plate 12. The bottom plate is provided with a linkage 13, 14 which carries the push rods 6 as well as the last 21. The closing lever 15 allows to hold the forementioned parts together in the desired position, or to swing the last with the side frame outwardly for the removal of the finished shoe. The bottom plate 12 and the last are heated to a temperature sufiicient for the heat-setting of the cement on the surfaces 9, 10, a temperature which is sufficiently low so as not to damage the.material of the upper, but usually sufficient to cause the material of the upper to shrink tightly to the last 21 and thereby receiving the set which assures satisfactory fit to the foot of the wearer. The compressibility of the welt material, such as porous rubber, is such that the spacing between upper and side frame can be achieved and after release from the side frame, the welt material can expand and return to the shape and location in relation to the upper which is desirable in the finished shoe. After removal from the last 21 the edge of the welt is shaped and the appearance improved by scouring, i.e. abrading it on an abrasive belt. In FIG. 2 and FIG. 3 the lines 16, 17 indicate the outside contour prior to the scouring to the uniform line 18.

It can be seen in FIG. 1, the compressibility of the welt 3 is used temporarily during the manufacture to eliminate any contact between the metal of the side frame and the leather of the upper. The compressibility also is important in that during the shrinking of the upper, the stitching 4 will at least at some parts of the perimeter move outwardly and compress the welt substantially. If the sole 11 also consists of porous elastomer such as rubber, preferably identical to the material of the welt, it will compress sutficiently so that only a thin layer of filler 19 might be required. Often the filler can be formed by a thin layer of a rubber mix with a blowing agent so as to form in situ the desired filling.

If desired, a more Wear-resistant tread sole 20 can be cemented to the sole 11 simultaneously with the cementing of the sole 11 to the welt 3.

As can be seen in FIG. 3 the scouring of the outside rim of the porous rubber welt and the identical sole can be used to give the entire sole along its edge a shape different from the shape of the side rim 5. If a contour for the sole edge is desired which cannot be easily produced by scouring, or for any other reason, the invention provides that the porous rubber used for the welting and the sole is placed into the cementing device in a blown, i.e. expanded, but only incompletely vulcanized or cured state. In such case the side frame 5 and/or the bottom plate 12 can then be used to impress upon the welt and sole the desired final shape and configuration. In such cases the heating of the apparatus described above accomplishes not only the heat-setting of the upper and the heat-setting of the cement connecting welt and sole, but also the final shaping of welt and sole as well as the molding and curing of a sponge rubber filler. This can be seen in FIG. 4, where a scalloped or otherwise ornamented edge 22 forms the side of the sole.

What I claim is:

1. Footwear comprising an upper, a welt stitched to the bottom margin of said upper, said welt being formed of highly compressible porous elastomer and being compressed, a mid-sole of elastomeric material secured to said compressed Welt, a tread sole, said compressed Welt being of substantially the same thickness as said midsole and surrounding said mid-sole and both said welt and mid-sole being secured to said tread sole.

References Cited UNITED STATES PATENTS PATRICK D. LAWSON, Primary Examiner

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