US2976624A - Footwear with soles containing rubber - Google Patents

Description

March 28, 1961 E. E. ROLLMAN y 2,976,624

FOOTWEAR WITH SOLES CONTAINING RUBBER Original Filed June 24, 1952 INVENTOR ERNEST E. ROLLMAN BY QM l fla/ila!! ATTORNEY 1nited States 2,976,624 FOOTWEAR WITH SOLES CONTAINING RUBBER Ernest E. Rollman, Waynesville, N.C., assignor to Roearclh, Inc., Waynesville, N.C., a corporation of North aro ma Original application June 24, 1952, Ser. No. 295,247, now Patent No. 2,789,295, dated Apr. 23, 1957. Di-v vided and this application Nov. 6, 1956, Ser. No. 620,699

3 Claims. (Cl. 36-14) atent f which the lower margin of the upper is pulled over the li edge of a last and tacked to an insole previously placed on the last. This insole is the element which holds the shoe bottom in the desired spatial position. The lasting is a relatively expensive operation and sometimes omitted for this reason, and replaced by providing a sock lining stitched to the lower margin of -the upper. A last is slipped thereafter in the so-prepared sock, although the so-obtained t of the upper on the last is at best incomplete. v

According to the invention the expensive preliminary operation of lasting can be omitted, and the t of the footwear improved by tightening the upper on the last, and securing the lower margin of the upper or parts connected thereto to a rubber layer set and vulcanized While the upper is held tightened. This eliminates not only the need for an insole as a structural part, which often has to be expensively pre-shaped, but assures a firm and resilient shoe bottom. it is advisable to use a heated last so as to obtain simultaneously a better and more permanent stretching and fitting of the upper and a proper and fast curing o-f the rubber.

The invention and its advantages are further clarified in the drawings which sho-w in Fig. l a cross-section of the edge of a shoe. Fig. 2 shows in a similar cross-section the edge of the shoe of a modifi-ed form. Fig. 3 shows in a similar cross-section an execution where a rubber layer forms the main sole. Fig. 4 shows in a similar View the edge of a shoe in which the rubber sole is enclosed by the platform wrapper. Fig. 5 shows in a similar cross-section the edge of a shoe with the sole formed by the upper, Welt and the rubber layer.

As shown in Fig. l, the upper 1, which might be partly or completely lined prepared in the usual way by stitching together various pieces of leather or fabric, is provided on its lower rim with an outward protruding extension formed by a welt 3, which might be a strip of leather stitched at 4 to the upper 1. An outsole 5 in turn is stitched at 6 to the Welt 3, the latter being of such thickness so as to leave space for a midsole oetween the last 8 and the outsole 5. Material for the midsole which comprises a layer 7 of felt, or similar material and a layer 9 of rubber mix, preferably to form porous rubber, is placed upon the last 8 and said upper is slipped over it, together with the welt and outsole This can be done easily, as the upper is still of baggy appearance and does not yet fit the last tightly. A lip 10 which may be divid-ed into various segments and is part of the mold enclosing the shoe bottom, is then placed against the lower rim of the upper into the groove formed 2,976,624 Patented Mar. 28, 1961- by the lower rim of the upper and the welt 3. The segments are moved then towards the center of the sole and thereby the upper is tightened on the last-by pushing its lower rim inwards. This is the state shown in Figs. l and 2. The assembly is then subjected to heat, preferably by heating the last 8. Under the influence of the heat, the rubber mix will expand and ll the space between the last and the outsole, and simultaneously bond to the margin of the upper welt as well as to the outsole. As the porous rubber is completely enclosed by the `leather welt and outsole, the shoe will offer better appearance and better resistance to wear than shoes with exposed porous rubber surfaces.

AAs shown in Fig. 2 the upper 1 might be stitched to the welt 3 by the seam 4 in such way that the rubber mix contacts only a part of the extension of the upper, not directly the welt strip- 3. Without deviation from the invention it might be of advantage to tighten the upper not by moving the lower rim inwards, but by holding the lower rim of the upper in the desired spatial relation while the upper is tightened by expandingv the last. Various types of foreshortening lasts might be used, but I found that metal lasts with inserted electric heating elements are preferable. The lower rim of the upper can be held in the desired spatial relation by segmented lips 10 or by the outsole and welt, if the shoe bottom offers the rigidity to hold the lower rim of the upper in its place vwhile the upper is stretched and the rubber layer vulcanized. Y

rI'he term lower margin of the upper is used here to designate the very end of the upper usually used for the lasting operation, while the term lower rim of the upperis used to designate that part of the upper adjacent to, or forming part of, the outwardly extending vrimA of the sole. The lower rim of the upper might be formed by the material of the upper or by a strip fastened to the upper. The term shoe bottom is used here to designate those parts of the shoe which hold the lower margin of the upper and is formed in the examples shown inthe drawings substantially by the rubber layer 9.

The term outward extension is used here to designate that part of a shoe which extends essentially horizontally outwardly from the lower rim of the upper to cover at least the upper rim of the sole. The outward extension might be a strip of material such as leather stitched to the upper, or it might be an outwardly turned part of the upper itself, which ends at the edge of the sole or continues downwardly to cover the side of the sole.

The method according to the invention is also used to advantage for shoes with platforms, as shown in Fig. 3, where the parts corresponding to those of Figs. l and 2 are designated by the same numerals; Here a platform wrapper 11, is shown stitched at 4 to the upper 1 to form again an outward extension and thereby a crease between the lower rim of the upper and the upper rim of the sole. During the heating of the shoe on the last 8 the rubber mix 9 expands and fills the platform completely. Once set, the expanded rubber will assure the maintenance of the desired shape of the platform and the shoe. If the wrapper 11 is not stiff 'enough to assure the -desired contour of the platform during the curing of the rubber, an auxiliary mold comprising a frame 12 and a sole plate 13 might be used to limit the space of the expansion of the rubber. As shown in Fig. 4, the platform wrapper might be a piece of the upper 1, cut correspondingly larger and fastened to an outsole 5 before placing it on the last 8. The crease between the upper and the platform is produced by pushing into place the lip 10.

Fig. 5 shows a cross-section of the edge of a shoe in which the upper 1, to which a welt 3 has been fastened by the stitching 4, is held in the desired shane by the rub- 3 ber sole 9 molded and vulcanized in situ. so as to hold the lower margin of the upper resiliently in the desired permanent position and to enclose at the same time a lller 7. It desired' a tread sole might be added after molding and vulcanization, but the shoe will be comfortable and durable also without such tread or wear Sole.

For other types of footwear the methods described above might be altered without deviation from the ini vention. The composite sho-e bottom shown Iin Fig. 2 might be replaced by a layer of rubber just strong enough to hold the margin of the upper in the desired spatial position and might then be less porous and more rigid as shown in Fig. 3, where the lower rim of the upper 1 is extended by the ywelt 3, which is placed behind the lip 10. The rubber layer 9, forming the sole, is contained between the frame 12 and the bottom plate 13 of the mold. Here again the rubber is sealed against the mold lip by the welt Seven if only very little or no pressure is exerted between the lip 10 and the upper 1. If rubber of sufficient strength is used it is possible for some types of footwear to use only a welt-like strip of rubber vulcanized to the lower margin of the upper to assure that the shoe bottom maintains its position, also after flexing it. In this instance as well as in other cases it might be of advantage to sew the outsole to the welt only after the vulcanization of the rubber or to prevent by other means the adherence of the rubber layer to the outsole, as then a worn outsole can be replaced easily without damage to the firm land waterproof shoe bottom.

The term rubber is used here for any natural synthetic elastomer with qualities similar to those of rubber obtained from the Hevea plant. According to the type of elastomer used, the setting might occur at normal or elevated temperature.

This application is a division of parent application Serial No. 295,247, led June 24. 1952, now Patent No. 2,789,295.

What I claim and desire to secure by Letters Patent is:

1. A shoe comprising material forming a shaped upper, said upper having a lower inturned marginal portion and an outwardly extending welt joined to said lower marginal portion, and a sole layer 01:" rubber molded and vulcanized in situ directly to the inner portion of said welt and to said lower marginal portion of said upper, said sole constituting the only structural element secured to said upper and Welt at the region of their joinder and holding in position opposite sides of said lower marginal portion of said upper to maintain said upper in its given shape.

2. A shoe as claimed in claim l further characterized in that said Welt is formed integrally with said upper. i

3. A shoe as claimed in claim 1 further characterized in that said welt is a `separate strip of material stitched to the lower marginal portion of said upper, one face of the stitching being embedded in said sole layer.

References Cited in the le of this patent kUNITED STATES PATENTS 772,027 Buttereld Oct. 11, 1904 774,865 Butterfield Nov. 15, 1904 1,138,961 Langenohl May 11, 1915 1,374,480 Trull Apr. 12, 1921 1,706,126 Peer et al Mar. 19, 1929 2,046,444 Belyea. July 7, 1936 2,129,106 .Szerenyi Sept. 6, 1938 2,283,953 Rohrer May 26, 1942 2,574,582 Rollm-an Nov. 13, 1951 2,651,118 Root Sept. 8, 1953 FOREIGN PATENTS 1,631 Great Britain Jan. 20, 1913 310,495 Germany Jan. 25, 1919 244,800 Great Britain Ian. 6, 1927 366,881 Italy Jan. l1, 1939 667,837 Great Britain Mar. 5, 1952

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