US3155994A

US3155994A - Wipers

Info

Publication number: US3155994A
Application number: US858196A
Authority: US
Inventors: Harry L Dent; David M Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-12-08
Filing date: 1959-12-08
Publication date: 1964-11-10
Anticipated expiration: 1981-11-10

Description

Nov. 10, 1964 H. l.. DENT ETAL 3,155,994

WIPERS Filed DBC. 8, 1959 la a? fave/Zinzi agy/ Pezzi/ United States Patent O 3,155,994 WEER Harry lL. Deut, Winchester, and David M. rillimmpson, Nashville, Tenn., assignors to .facolta S. lamhorian, West Newton, `lass.

Filed Bec. il, 1959, Ser. No. Sd,ll96 l2 Claimsu (Cl. 12m-lds) This invention relates to apparatus and a method of lasting the ends of shoes, in particular, the toe end, and has for its principal objects to provide improvements in the wipers which will reduce damaging the surface of the upper, particularly at the shoulder of the last, during the overwiping operation, and especially in manufacture of patent leather shoes, without loss of the smoothness, tautness and sharp feather line ordinarily required and attained by conventional lasting operations.

As herein illustrated, this is accomplished with conventional rigid metal wiper plates, by covering their leading edges with a material having a very low coefficient of friction with respect to the shoe upper. Gpiionally, an appreciable amount of yield is desired to cushion the impact between the wipers and the end of the last as they are brought together. The covering material is applied to the upper sides of the wipers, with portions extending downwardly over their leading edges, to the plane of the undersurfaces of the wipers and is comprised of Teflon, although it is to be understood that other equally durable and chemically resistant, non-metallic compositions may be employed having a comparable coefficient of friction with respect to the upper material.

Broadly, the method of lasting with the aforesaid wipers and their covers comprises applying wiping forces to the margin of the upper at the shoulder of the last, to stress the margin heightwise and fold it over onto the bottom with an implement, the surface of which has a very low coefficient of friction with respect to the upper and desirably, although not necessarily an appreciable amount of yield and thereafter applying wiper forces inwardly, parallel to the bottom, and perpendicular thereto to stretch the inwardly folded marvin inwardly and press it downwardly.

In a preferred mode of operation the Teflon covers are conformed to the wiper plates by fastening sheets of Teflon, one to each of the wipers, with the edges of the sheets extending beyond the edges of the wipers and then effecting relative movement between the wipers and the naked last to force the concave leading edges of the wipers and the convex surface of the end of the last into engagement and, by such interengagement, to press the Teflon sheets inwardly against the concave leading edges of the wipers to cause them to take the shape of the edges. The wipers and last are then separated, and if there is an excessive amount of the sheet material extending below the plane of the underside of the wipers, it is trimmed olf. The molding of the Teflon sheets to the contour of the wipers may be accomplished solely by pressure, however, an application of heat expedites the operation.

The invention will now be described in greater detail with references to the accompanying drawings wherein:

FIG. 1 is a plan view of the upper part of a machine for lasting toes of shoes, with the coverplate removed to show the wipers, wiper support, and portions of the mechanism for operating the wipers;

FlG. 2 is a vertical section taken on the line 2-2 of FIG. 1, showing a Teilon cap applied to the forward end of one of the wipers;

FIG. 3 is a perspective view of a wiper covering cap;

FlG. 4 is a vertical section of the upper part of the toe lasting machine showing the successive positions of the wipers and the last for molding a moldable sheet t0 the wipers; and

3,155,994 Patentes Nov, 1o, 1964 ICC FIG. 5 is a vertical section through the forward end of a wiper showing another form of covering.

Referring to FIGS. l and 2, there are shown wipers 1li-Iii? supported by carriers 1li-1l, for movement in a horizontal plane relative to the bottom of a last L, the latter being supported bottom side up, with its toe resting on a toe support l2, according to the teaching of Patent No. 3,011,186. The insole and upper i4 and 16 are assembled on the last so that the margin m of the upper stands upright from the insole. The wipers which are moved forwardly to close about the toe of the last by the mechanism i7, operate to stress the upwardly projecting margin inwardly over the shoulder of the last and the bottom, so as to pull the upper taut and smooth about the top side of the last. in accordance with the practice disclosed in the aforesaid application, the support l2 is movable vertically with respect to the wipers and during the lasting operation the wipers and support are manipulated to bring the wipers into engagement with the upper material below the shoulder of the last, and to move the support heightwise with respect to the wipers after they are engaged with the last, to stress the upper heightwise as it is being folded in over the shoulder into engagement with the bottom. After folding, the wipers are advanced parallel to the bottom and the support is forced upwardly against the underside of the wipers to apply forces parallel and perpendicular to the bottom, to stress the margin inwardly and press it down.

A great many shoes are damaged during this operation by careless manipulation of the wipers on the part of the operators which, if moved inwardly too fast or too hard or with too much pressure, because of their unyielding character, and their relatively high coeil'icient of friction with respect to the upper material, .cut into the upper material as they are brought into engagement therewith and scratch, scar and otherwise mar the upper as they slide over the shoulder into engagement with the bottom.

To minimize such damage the leading edges 18-18 of the wipers lillli which, as herein shown, are rigid metal plates, are covered with a non-metallic material which is smooth enough so that a minimum amount of frictional resistance to sliding movement is created between the wipers and the upper material as the wipers move inwardly over the shoulder. Optionally, the material should be yieldable enough to absorb some of the shock of impact as the wipers are brought into engagement with the upper. To this end the coverings are in the form of molded Teflon caps 2li-2S (FIG. 3), fastened to the upper sides of the wipers 1li-l@ by clamps 22u22, the latter being bolted to the wiper carriers Eil-d1. To insure a firm grip and to prevent possible movement, the rear ends of the caps are butted against the forward edges of the carriers and the clamps have teeth 24 which bite into the upper surfaces of the caps. The caps extend downwardly over the leading edges of the wipers and terminate in the plane of the bottom surface of the wipers. The Teilon is suiiiciently stiff and rigid so that when molded to the shape of the wipers, as shown, it will retain this shape without fastening the lower edges of the caps.

Alternatively, the coverings may be strips of glass fabric 25 coated on one side with Teiion and on the other side with an adhesive. The strips are applied to the forward edges of the wipers, as shown in FIG. 3, by the adhesive coating and extend rearwardly over the top and bottom surfaces an appreciable amount. The Teflon coated fabric makes it possible to quickly modify existing wipers for a few shoe manufacturing operations and thereafter to remove and discard the same without appreciable loss.

'l`eiion, as defined in the Handbook of Material rfraaie Names, 1953 edition, Zimmerman and Lavine, is a plastic consisting of tetrafluoroethylene polymer. The physical and chemical properties of f'leflon are discussed extensively in the publication Teflon, Second Edition, February i959, E. l. du Pont de Nemours, Inc., Wilmington, Delaware and the physical properties which are uniquely suited to the lasting operation are its low coeflicient of friction and its 'ieldability which provides cushioning properties. The coefficient of friction of Teflon is 0.01, the lowest of any known solid (see Scientific American, November 1959, page l5). The publication Teon rates the coefficient of friction of Teflon to Micropolished Steel as 1 is to 11/2 to 2%. Teflon has a hardness of 55 to 65 on the Shore durorneter scale of hardness of 59 to 62 on the same scale.

According to the brochure, entitled Frictional Properties of TFE Fluorocaroon Resins, reprinted from Materials in Design Engineering, Gctober 1958, issue, locating above 50 pounds does not appreciably increase the friction hence increasing the wiping pressure does not correspondingly increase the friction when using Teflon covers on the wipers. Since the speed of movement of the wipers is very low any increase in friction which might be caused by speed of movement may be ignored. For practical purposes therefore the static friction of Teflon is the only consideration and as pointed out above this is lower than any known solid.

The rigid molded cap is preferred because it can be fastened in place quickly without modifying the wipers, can be removed easily when not required for the particular operation and is long wearing. The Teflon coated fabric is useful as a temporary expedient and has the advantage that it may be applied and stripped off quickly for a few operations and thrown away. The only disadvantage is that such coverings wear out quickly.

Wipers equipped with the Teflon cover, described above, have such a low coefficient of friction with respect to the upper material that they slide over the shoulder of the last without scufling or otherwise scarring the upper. Moreover, because of the slightly yielding character of the Teflon, the pressure applied at the shoulder is reduced so that there is less likelihood of pinching. Thus, by employing an implement having a smooth surface which is slightly yieldable, the upper may be stressed hcightwise and folded inwardly over the shoulder without damage to the upper material at the shoulder.

Conveniently the rigid caps 2t) can be made in situs by the operator or by a factory maintenance man to fit the wipers without removing the latter and, moreover, to take their shape accurately. To this end, referring to FIG. 4, sheets 26 of Teflon or other suitable moldable material are placed against the upper sides of the wipers and clamped thereto with the clamping member 22. The free edges of the sheets are folded downwardly over the edge of the wipers and trimmed off. The end of the naked last L, supported on the roller 12 is moved inwardly toward the wipers so as to force the sheet material to take the concave shape of the leading edges of the wipers. The last is then withdrawn from the wipers. If there is any excess of sheet material below the lower surfaces of the wipers it is trimmed olf. Molding of the Teflon may be effected solely by pressure, however, heat will expedite the operation. When using Teflon coated fabric the latter is preferably cut or tailored to the shape of the wipers and then applied to the edges by pressing it about the edges and the top and bottom surfaces adjacent thereto. If desired, the edge may be pinked to cause the material to fit more closely to the curved surfaces.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents falling within the scope of the appended claims.

We claim:

1. In a machine for lasting the ends of shoes, wipers and a shoe support for supporting a last upon which an insole and upper may be assembled, means supporting the wipers comprising cam plates and means fastening the wipers to the underside of the cam plates, Tellen caps disposed on the upper sides of the wipers with portions engaged with the edges of the cam plates and other portions extending downwardly over the leading edges of the wipers and conformed thereto, and clamp plates bolted to the cam plates with portions clampingly engaging the caps adjacent the cam plates, and teeth projecting downwardly from said clamp plates into engagement with the caps.

2. ln a shoe lasting machine having a shoe support for supporting a last having a shoe upper and insole thereon; a wiper made of rigid material for folding the margin of the upper onto the insole; and means mounting the wiper and support for relative movement of the wiper across the insole; the improvement comprising: a material positioned on the wiper in the portion of the wiper facing the last having a substantially lower coefhcient of friction with respect to the upper than the rst mentioned material.

3. The lasting machine according to claim 2 wherein said material is composed of Teflon.

4. ln a shoe lasting machine having rigid metal wipers; a shoe support for supporting a last having a shoe upper and insole thereon; and means mounting the wipers and support for relative movement of the wipers across the insole; the improvement comprising: means applied to the leading edges of the wipers which has a substantially lower coefcient of friction with respect to the upper than the wipers.

5. ln a shoe lasting machine having rigid metal wiper plates; a shoe support for supporting a last having a shoe upper and insole thereon; and means mounting the wiper plates and support for relative movement of the wipers across the insole; the improvement comprising: means applied to the leading edges of the wiper plates which has a substantially lower coefcient of friction with respect to the upper than the metal wiper plates and which is yieldably compressible.

6. In a shoe lasting machine having wipers; a shoe support for supporting a last having a shoe upper and insole thereon; and means mounting the wipers and support for relative movement of the wipers across the insole; said wipers comprising rigid metal plates, the leading edges of which are curved conversely to the end of the last, so as to gather the upper as the latter is stressed about the toe; the improvement comprising: covering caps fastened to the wiper plates, said caps having depending margins covering the leading edges of the wipers and being comprised of a material having a lower coefficient of friction with respect to the upper than the metal wiper plates.

7. In a lasting machine according to claim 6, toothed clamps for fastening the caps to the wiper plates.

8. In a shoe lasting machine having wipers; a shoe support for supporting a last having a shoe upper and insole thereon; and means mounting the wipers and last .for relative movement of the wipers across the insole; the improvement comprising: means fastened to the wipers having portions extending downwardly over their leading edges to the plane of their bottom surfaces, said portions having a substantially lower coefficient of friction with respect to the upper than the wipers and being yieldably compressible.

9. In a shoe lasting machine having wipers comprised of rigid metal plates; a shoe support for supporting a last having a shoe upper and insole thereon; and means mounting the wipers and support for relative movement of the wipers across the insole; the improvement comprising: Teflon caps clamped to the upper sides of the wipers, said caps having portions extending over the leading edges of the Wiper plates and terminating llush with the under surfaces thereof.

l0. In a shoe lasting machine having wipers comprised of rigid metal plates; a shoe support for supporting a last having a shoe upper and insole thereon; and means mounting the wipers and support for relative movement of the wipers across the insole; the improvement comprsing: ex-ible sheets of glass fabric, coated on one side with Teflon and on the other side with adhesive, adhered to the leading edges of the wipers and to the upper and lower surfaces adjacent thereto.

11. The method of lasting comprising supporting a last with an insole and upper assembled thereon with the margins of the upper projecting away from the shoulder of the last, and wiping the margins over the shoulder of the last against the insole with an implement made of relatively rigid material and having at least a portion of its margin engaging surface covered with a material having a substantially lower coefficient of friction with respect to the margins than the first mentioned material.

12. A method of lasting comprising: supporting a last having an insole located on its bottom and an upper assembled thereon with the margin of the upper projecting away from the bottom of the last; and wiping the margin against the insole by moving against the margin and across the insole an implement made of relatively rigid material that has at least a portion of its margin engaging surface covered with a material that has a substantially lower coeflicient of friction with respect to the margin than the rst mentioned material.

References Cited in the le of this patent UNITED STATES PATENTS 418,694 Dean Jan. 7, 1890 1,168,012 Chapelle Jan. 11, 1916 1,856,292 Pym May 3, 1932 2,026,099 Pym Dec. 31, 1935 2,235,887 Kamborian Mar. 25, 1941 2,357,950 Goessling Sept. 12, 1944 2,431,393 Franklin Nov. 25, 1947 2,455,467 Burby Dec. 7, 1948 2,596,169 Proulx et al May 13, 1952 2,617,127 Stacey et al Nov. 11, 1952 2,631,309 Lancaster Mar. 17, 1953 2,651,063 Hill et al Sept. 8, 1953 2,990,559 Gilbn'de July 4, 1961

Claims

1. IN A MACHINE FOR LASTING THE ENDS OF SHOES, WIPERS AND A SHOE SUPPORT FOR SUPPORTING A LAST UPON WHICH AN INSOLE AND UPPER MAY BE ASSEMBLED, MEANS SUPPORTING THE WIPERS COMPRISING CAM PLATES AND MEANS FASTENING THE WIPERS TO THE UNDERSIDE OF THE CAM PLATES, TEFLON CAPS DISPOSED ON THE UPPER SIDES OF THE WIPERS WITH PORTIONS ENGAGED WITH THE EDGES OF THE CAM PLATES AND OTHER PORTIONS EXTENDING DOWNWARDLY OVER THE LEADING EDGES OF THE WIPERS AND CONFORMED THERETO, AND CLAMP PLATES BOLTED TO THE CAM PLATES WITH PORTIONS CLAMPINGLY ENGAGING THE CAPS ADJACENT THE CAM PLATES, AND TEETH PROJECTING DOWNWARDLY FROM SAID CLAMP PLATES INTO ENGAGEMENT WITH THE CAPS.