US2385554A - Manufacture of footwear - Google Patents

Description

Sept. 25', 1945. M. G. sTRAT'roN MANUFACTURE OF FOOTWEAR Filed Jan. 11 1944 u fname. WMZ 551m Q? 42 Patented Sept. 425, 19.45

UNITED STATE I Michael Stratton, Weston, blass., assignor to Compo Shoe Machin ery Corporation, Bolton,

This invention relates to the manufacture of footwear, and more particularly to methods of making prewelt shoes wherein the upper is permanently secured to the insole to hold the'parts in lasted relation.

In the manufacture of prewelt shoes, it has been general practice to bring the upper intoA lasted relation to the insole with the wipers ofa lasting machine, and then temporarily fastening an outsole to the welt, in order to keep the upper in lasted relation while the shoe is removed from the lasting machine and transferred to other machines forpermanent securement of the outsole. Shoes as so constructed are not considered to be repairable, as, when a worn outsole is removed prior to application of a new outsole, the entire upper spreads away from the insole and must be relasted on the original last before a new outsole can be attached.

Furthermore, if the outsole is attached to the welt by stitching, theentire strain of the foot tending to spread the upper, is applied to they stitches; and long before the outsole is entirely worn out the wear in the stitches cause them to ,pull through the outsole and the shoe spreads apart rendering it unwearable and not readily, repairable.

Previous attempts to remedy these failings, such as securing a midsole to the welt to hold the shoe together, application of stay pieces to secure the upper to the insole or filler material by adhesive or metallic fasteners, or the application of a per-f manent adhesive between the upper and insole have only resulted in adding considerable expense to the manufacture of the shoe or have so prolonged the lasting operation that additional machinery is required.

'I'his invention provides improved methods of making a prewelt shoe which comprises, temporarily attaching a welt to the upper with adhesive therebetween; bringing the welted upper .K into lasted rennen to the insole with adhesive the outsole is outworn it may be removed and the l shoe upper having been permanently bonded to the insole will stay in lasted relation whilea new sole is attached to the welt.

An object of the invention is to reduce the cost of manufacture of prewelt shoes.

Another obiect of'the invention is to provide readily repairable prewelt shoes.

A further object of the invention is to reduce the `cost of manufacture 1of vrepairable, prewelt shoes. y

A still further object of the invention is to provide improved methods of making prewelt shoes which eliminate the necessity of maintainingseparate lasting and sole securing equipment.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

For da fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken inv connection with the accompanying drawing, in which: t y

Fig, 1 is perspective view of a shoe uppr showing the marginal edges of its lasting allowance roughed and coated with an adhesive;

Fig. 2 is a perspective view of the upper of Fig. 1 and shows the securement of a welt thereto: x

Fig. 3 is a sectional view through the forepart? of the shoe upper and a last prior to its placement in a lasting machine; Fig. 4 is a sectional view of the shoe oi Fig. 3 and shows the upper brought into lasted .relation by the wipers ofa lasting machine, and

Fig. 5 is a partial view in cross-section, of a lasting machine with a shoe held in its wipers and its sole pressing pad in contact with an outl sole positioned on the shoe, and shows diagrammatically the connection of a high frequency,

electrical source to the shoe. a V

'Referring to Fig. 1, the conventional upper III is preferably roughed or skived along the outer or grain side Il of its lasting margin and both sides of such margin is coated with an adhesive electrodes in the pad and in of the type which can be activated by the application of heat in a following step. 'I'hen as illustrated by Figs. 2 and 3, the welt I2, which is preferably roughed or skived on its grain side I3l along a margin corresponding to a width engaged by the upper, is coated with the adhesive along the roughed margin of its grain side i3 and over the entire area of its flesh side il.

The welt I2 is temporalysecured to theupper il by stitching I5, staples, or other fasteners, so

that the welt can be used to last into relation with the insole in the conventional Thewelted l Il. having an electrodeor metal plate i1 on its bottom, and an insole i8 having the marginal edge"y oi' its lasting tace coated with lthe adhesive is placed in position on the last bottom: The assembly is then placed asillustrated'in Fig. 4 in a lasting machine havingvthe wipers 2 8 which 'eagles in the welt crease and bring the upper in lasted relation with the insole I8, the inner adhe'- sive coated marginal edge of the upper I8 contasting the adhesive coated margin I9 of the insole Il. 'I'he conventional illler piece 2| is then upper is then assembled upon a last.

placed on the insole I8 or it may be attached to the insole prior to the lasting.

The outsole 22 has the margin 28 of its attachl ing tace roughed as usual and coated with the adother known sources oi.' heat may be used. 'l'.'he methods of the invention may be carried out with any/conventional lasting machines such', for example. as those disclosed in U. S. Patents Nos. 2,008,788 and 2,071,396. Y

The steps of the method recited in the annexed claims are not to be interpreted as necessarily all occurring in the orders oi' recitation, and it is to be understood that the shoe illustrated may have a lining and that the term upper" includes such lining or other plies.

-Having describedY my invention, what I'claim as new and desire to secure by Letters Patent is:

1. Themethod of making pre-welt shoes which comprises applying a thermo-plastic adhesive to the welt engaging margin of a shoe upper and to the corresponding upper engaging margin of 'a welt and allowing the adhesive to harden or dry to a non-tacky state; temporarily securing saidwelt and upper together; applying a thermo- `plastic adhesive to the upper engaging margin of an insole and to the corresponding insole engaging margin of the upper and allowing the adhesive to harden or dry to a non-tacky state; bringareas of the welt and outsole. together. To prev vent undue strain on the wipers 20 and make sure that pressure is applied to all voi the adhesive,`

coated areas, the shoe may be supported below the wipers by the usual toe and heel supports or pressure resisting. members (not shown).

To apply heat to activate the adhesive an electrostatic eld is created and this is accomplished by providing a metal plate or electrode 28 in the sole pressing pad 25. This electrode 2B is connected by the lead 21 to one side of the high freriuency electrical source 28. 'I'he metal plate I1 on the last bottom forms the other electrode and' is contacted by the pin 29, which in turn contacts the conventional metal last thimble 80 and a last pin 8| engaging in the thimble isconnected by source 2.8. The electrode 26 in the sole pressing padl 28 extends the full length of the shoe and between it and the last bottom electrode l1, there is created an electrostatic iield which activates the adhesive in the pressed together areas between the insole and the upper; between the welt and the upper, and between the welt and the outsole, resulting in the simultaneous bonding of the Parts together.

'Ihe action of the electrostatic ileld established between such electrodes in activating the adhesive by heat generated therein as well as descriptions o! suitable adhesives are fully disclosed -in the United States Patent N0.'Re. 22,301 of E. C. Pitman and may be fully understood with reference thereto.

While the source of heat for activating the :ad-

; belive has been described as electrostatic ileld,

^ the lead 82 to the other side of the high frequency ing said upper in lasted relation with said insole with the wipers of a pre-welt lasting machine: applying thermo-plastic adhesive to the outsole .engaging margin of the welt and to the correspending welt engaging margin of an outsole and allowing the adhesive to harden or dry to a non- -tacky state; pressing said outsole against said lasted upper with the pad of said machine; and while the shoe is maintained in lasted position by said machine simultaneously establishing van electrostatic leld in the adhesive between said welt and upper, in the adhesive between said upper -and'insole, and in the adhesive between said welt and outsole,.for heating said adhesive and activating same.

2. 'I'he method of making pre-welt shoes which comprises applying a thermo-plastic adhesive to the welt engaging margin of a shoe upper and to the corresponding upper engaging margin of a,-

welt and allowing the adhesive to harden or dry to a non-tacky state; stitching said welt and upper together; applying a thermo-plastic adhesive to the upper engaging margin of an insole and to the corresponding insole engaging margin of the upper and allowing the adhesive to harden or dry to a non-tacky state; bringing said upper in .lasted relation with said insole with the wipers of a pre-welt, lasting machine; applying thermoplastic adhesive to the outsole engaging margin of the welt and to the corresponding welt engaging margin of an'outsole andallowing the adhesive to harden or dry to a, non-tackystate; pressing said outsole against said lasted upper with the pad of said machine; and while the shoe is maintained in lasted position by said machine simultaneously establishing an electrostatic fleld in the adhesive between said welt and upper, in the adhesive between said upper and insole, and in the adhesive between said welt and outsole, for

heating vsaid adhesive and activating same.

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