US3422475A - Process and apparatus for shaping a shoe upper and bonding a shoe upper to an insole - Google Patents

Description

Jan 21, 1969 ART 3,422,475

PROCESS AND APPARATUS FOR SHAPING A SHOE UPPER AND BONDING A SHOE UPPER TO AN INSOLE Filed April 1, 1966 INVENTOR HENRY H. HART W2 MMA.

A ORNEY United States Patent 3,422,475 PROCESS AND APPARATUS FOR SHAPING A SHOE UPPER AND BONDING A SHOE UPPER TO AN INSOLE Henry H. Hart, St. Albans, W. Va., assignor to Union Carbide Corporation, a corporation of New York Filed Apr. 1, 1966, Ser. No. 539,430 US. Cl. 12-145 4 Claims Int. Cl. A41d 21/12, 29/10, 89/00 ABSTRACT OF THE DISCLOSURE In bonding a shoe upper to an insole, an insole is positioned on a shoe last mounted on a movable support and formable shoe upper material is placed about the last. The last is forced against an elastomeric diaphragm supported by fluid pressure and by the differential pressure applied to the diaphragm it is caused to envelope the last, to conform the upper material to it and to fold marginal edges thereof over the insole to which it may be adhesively bonded.

This invention is directed to a process and apparatus for bonding a shoe upper to an insole or shaping a shoe upper over a shoe form and bonding said shoe upper to an insole.

Heretofore, in the manufacture of shoe uppers, the process of bonding a shoe upper to an insole is part of the multistep procedure known as lasting. The lasting operation involves mulling leather with steam or moisture, shaping the leather about a shoe last with extreme pressures and fiXing the leather at the outer margins onto an insole located on the sole portion of the shoe last. Much of the pressure which is supplied to get the leather over the sole portion of the last and into contact with the insole is physically applied and assisted by machinery. In addition, there is employed a number of machines to achieve lasting. No single machine accomplishes the total operation of bonding the upper to the insole. For example, there is a machine which handles the heel but not the toe and there is a separate machine which handles the toe and places it in bonding relationship with the insole but does not contribute in any manner to the bonding of the heel portion to the insole. Thus, the capital investment required in the lasting operation is considerable. More than simple capital investment, there is exceptionally high labor expense since each machine is handled by either the same or a diflerent operator and therefore the utilization of a plurality of machines by the same or different operator is time consuming and expensive. In addition, the pressures which are applied and necessary to effect the lasting operation is achieved by pulling the outer marginal end of the leather piece which marginal end makes contact with the insole, and thus, most of the strain on the leather piece is exerted from very localized points. This creates the possibility of tearing and abrasion of the leather piece, particularly about the sole line formed on the last. In addition, considerablev force is necessary to place the marginal end of the shoe upper into direct contact with the insole therebycausing wear on the mechanical equipment employed and, therefore, necessitating shutdowns and expensive replacements from time to time. Indeed, the equipment utilized in the lasting procedure require expert knowledge in their usage and therefore require highly trained personnel. This means that the shoe manufacturer must bear an expensive labor overhead and of necessity, must provide a satisfying labor atmosphere.

There is described herein a process and apparatus which avoids all of the problems described above. This invention provides a process and apparatus for accomplishing "ice the process which avoids almost all of the steps in the conventional lasting operation, and achieves faster bonding of a shoe upper to an insole or effects shaping and bonding a shoe upper to form a shoe upper intermediate suitable for the soling operation. In addition, the equipment employed in the process of this invention may be utilized with any size shoe, be it a child or a baby shoe, a womans shoe or a mans shoe, without redesigning, or any other special equipment other than the utilization of a shoe form having the dimensions of the particular shoe upper desired. The apparatus of this invention comprises a minimum of moving parts, is simple to construct, and its overall cost is considerably below that of any one of the many pieces of equipment normally utilized in the lasting operation.

The process of this invention utilizes very gentle yet aggressive non-localized pressure for bonding the marginal ends of a shoe upper material into adhesive contact with the insole so it may be adhesively bonded to the insole. This minimizes damage to the shoe upper material and, at the same time, provides a close fit of the material to the shoe form to which it is shaped and/or to which the insole is fixed. Thus, the process of this invention is accurate and consistent in achieving size control and the only adjustment necessary to vary size control is the size and selection of the particular shoe form or last over which the shoe upper is placed. The process of this invention allows the shoe upper material to assume the exact dimension of the shoe form.

The process of this invention comprises the association of a sheet of shapeable shoe upper material in enveloping relationship of a shoe form. The shoe form possesses an insole on the sole portion thereof. Then the form and the material are impressed in an elastomeric sheet which is sustained by fluid pressure. The material is provided between the form and elastomeric sheet so as to intervene the form and elastomeric sheet. There is supplied to the sheet suflicient fluid pressure and suflicient pressure is provided on the form and the material so that the sheet substantially envelopes the material and form whereby the outer margin of the material is forced into contact with the insole provided on the sole portion of the form. Then the material at the marginal edge is adhesively bonded to the insole.

The apparatus suitable for affecting the process described above involves means for providing a shoe form containing an insole at the sole portion thereof in contactable relationship with the surface of an elastomeric sheet, means which are provided for associating a sheet of shapeable shoe upper material in enveloping relationship of the shoe form, means for applying a fluid pressure to the surface of the elastomeric sheet which is out of contactable relationship with said form, and means for impressing said form in said elastomeric sheet whereby said elastomeric sheet envelopes said shoe form.

In order to illustrate this invention, recourse is made to the accompanying drawings which, with the following description, depicts specific illustrations of the apparatus and process described previously. However, it can be seen from the rather detailed description which follows that it is not the intention to have this invention restricted by the following disclosures for it is clear that one having ordinary skill in this art could practice this invention by use of equipment and processes which differ from those hereinafter described yet which accomplish this invention and are the full equivalent of that which follows:

FIGURE 1 is a side view of an apparatus useable in the practice of this invention.

FIGURE 2 is a top view of cover plate 1 and flanges attached thereto as illustrated in FIGURE 1.

With respect to FIGURE 1, there is described the forming assembly 1 and the insertion assembly 3 with a shoe last covered by a shapeable shoe upper material. With respect to assembly 1, cover plate 2 is a one-half inch, 24 x 24 inch steel plate, possessing opening 4 therein and is secured to box 7 by bolts and nuts 9 inserted through holes 10 (see FIGURE 2). Box '7 comprises four pieces of mitred and welded 8 inch by 2 /2 inch channel steel plates to form a 24 inch square box determined by measurement of the terminal edges of the channel. Box 7 is thereafter secured by bolts and nuts 9 to bottom plate 8 with inch gasket 12 therebetween. Assembly 1 rests on one-half inch thick, 12 inch diameter steel plate 13 which, in turn, rests on four inch diameter steel pipe 11, welded to one-half inch base plate 17 resting on the floor. Plate 13 is fastened to bottom plate 8 by screws tightly fitted in threaded holes 19.

Acting as a gasket between box 7 and cover plate 2 is continuous elastomeric sheet 5 which also extends across the complete open surface of box 7 and has a surface area and shape corresponding to cover plate 2. Elastomeric sheet 5 may be made of cured, natural or synthetic rubbers, silicone rubbers, neoprene (poly(2-chloro-l,3- butadiene)), polyethylene-propylene rubbers, polyurethane elastomers, and the like. Any elastomer is useable in the practice of this invention and the selection thereof is not critical to this invention. Any elastomer is useable and the choice is dependent on its physical properties at the temperature employed over an extended period of time. Therefore, if the elastomeric sheet is to be heated, it is desirable to employ an elastomer which possesses good physical characteristics over an extended number of uses at the temperatures employed. Inside of box 7 and enclosed by elastomeric sheet 5 and bottom plate 8 is fluid 6. Fluid 6 may be any gas or liquid (preferably one which is not explosive and which does not adversely effect the elastomeric sheet 5), and include, e.g., water, steam, conventional hydraulic fluids, oils, air, nitrogen, argon, and the like. The amount of fluid 6 provided in box 7 or the pressure thereof, should be insuflicient to rupture the seal between cover plate 2 and bottom plate 8 with box 7, particularly when an outside pressure is applied to fluid 6. If temperatures in excess of 212 F. are desired for the process of this invention, then it might be desirable to utilize conventional heat exchange salts or liquids as fluid 6, or any other inert high boiling liquid which does not adversely effect the continued operation of the process of this invention.

With respect to assembly 3, there are shown two onehalf inch thick flanges 20 bolted onto cover plate 2 by four nuts 21 which are locked in threaded holes 23. Resting in the inch diameter holes 24 in flanges 20 are guide rods 25 having an outside diameter of /1 inch. Fitted about and extending between guide rods 25 is assembly plate 26 made of one-half inch thick steel and fitted with oversized holes 27 circumscribing guide rods 25. Unless supported, assembly plate 26 would readily slide down the length of guide rod 25. Fitted above and welded to assembly plate 26 are two sleeves 28 which assist in the movement of assembly plate 26 up and down guide rods 25. Fastened to assembly plate 26 is block 31, possessing threaded holes 32 to which bolts 30 are secured. Internally mounted in block 31 are screws 33 threaded into threaded holes 34 of plate 35. Secured about one inch diameter shaft 37 is a one inch inside diameter collar 36 frictionally engaged against shaft 37 by Allen head screw 38. At the bottom of shaft 37 is threaded hole 39 into which is screwed taper 40. Resting against the top of assembly plate 26 is one and inch inside diameter spring 42 circumscribing shaft 37 and abutting at its other end against one inch inside diameter collar 44, which also circumscribes shaft 37. Above collar 44 is slidable sleeve 46 which is welded on opposite sides to bars 48 possessing holes 50 through which pass guide rods 25. Above bars 48 are collars 52 which are locked into position by Allen head screws 54. Collars 52 have an inside diameter of /1 inch.

At each end of bars 48 outside of guide rods 25 are handles 49.

As is apparent from the above description of assembly 3 it can be modified to employ mechanical, electric or hydraulical means to control and/or position assembly 3 thus obviating the requirements of hand labor to carry out the function of assembly 3. For example, shaft 37 may be raised and lowered by electric motors, hydraulic pistons for the purpose of automating the operation of assembly 3, and the shaping process described herein.

Frictionally fitted onto taper 40 is shoe last 60. Taper 40 extends into taper hole 62 having the same configuration and diameters as taper 40 and which extends through the bottom surface or sole of last 60. Placed on the outside surface of shoe last 60 is shapeable shoe upper material 64, such as leather, poromeric materials (e.g., Corfam, a trademark for a poromeric material manufactured and sold by E. I. du Pont de Nemours & Company, Wilmington, Del), polyvinylchloride film, thermoplastic film, fabrics made of natural or thermoplastic fibers, formable sheet material and the like. The ends 65 of shapeable shoe upper material 64 extend above the bottom of shoe last 60. Resting on the bottom of shoe last 60 is insole sheet 66.

In the practice of the process of this invention, downward pressure is applied to handles 49 causing bars 48 and assembly plate 26 to travel down guide rods 25 thus forcing shoe last 60 with shapeable shoe upper material 64 to make contact with elastomeric sheet 5, as shown in phantom in FIGURE 1. Additional pressure is applied to handles 49 causing shoe last 60 to depress into elastomeric sheet 5 causing it to expand until shoe last 60 is far enough in the interior of box 7 so that pressure of fluid 6 within box 7 causes the elastomeric sheet 5, at above the edges 65 of shapeable shoe upper material 64, to envelope shapeable shoe upper material 64, particularly at about edges 65 thereby causing edges 65 to lay down on insole 66. Simultaneously, because of expansion of elastomeric sheet 5 from pressure point X on the surface of shoe last 60, there occurs a gentle wiping action on shapeable shoe upper material 64 forcing it to tightly wrap about shoe last 60 followed by the wiping action of edges 65 onto insole 66. If, prior to insertion of shoe last 60 into elastomeric sheet 5, adhesive is applied to the surface of insole 66 and/ or the inside edge 65, then as the edge 65 is wiped onto insole 66, pressure contact is suflicient so that upon curing or setting of the adhesive, or pressure contacting, if a pressure sensitive adhesive is employed, there is obtained a tight bond between the insole 66 and edges 65. This holds shapeable shoe upper material 64 on last 60, and material 64 conforms almost exactly to the shape of last 60.

As can be seen from FIGURE 2, opening 4 has a shape which allows passage of shoe last 60 into contact with elastomeric sheet 5.

In the practice of this invention, particularly when fluid 6 is a liquid and higher temperatures are desired, immersion heaters may be inserted in the interior of box 7 to provide accurate temperature control of fluid 6. However, this does not exclude the use of heaters in box 7 when the fluid is gaseous. If the adhesive applied to insole 66 and edges 65 are heat setting, then heat can be affected through heating of fluid 6. If desired, ports may be introduced through bottom plate 8 to introduce and withdraw, continually or intermittently, any quantity of fluid, whether preheated or not. Pumps may be employed either inside or outside of box 7 for circulation of fluid 6 as is considered desirable.

If it is desired, last 60 need not be rammed into elastomeric sheet 5, and instead, the last may be inserted into a loose fitting elastomeric sheet 5, followed by providing fluid pressure by the amount of fluid 6 introduced to box 7 to cause elastomeric sheet 5 to enclose about last 60. A deficiency of this procedure over that described in the drawings, is the lack of control of the wiping action of elastomeric sheet on shapeable shoe upper material 64 during the bonding operation.

Though the above description shows the utilization of a shapeable shoe upper material conforming to the shape of the last yet prior to bonding to the insole, it should be appreciated that the shapeable shoe upper material 64 need not be fitted about last 60 as described in FIGURE 1. Instead, a pattern of a shoe upper having a cut out ankle opening may be fitted onto last 60 and during the shaping operation, by action of sheet 5 on the shapeable shoe upper material, the shapeable shoe upper material will conform to the shape of the last, and its ends can be wiped over into contact with the insole on the bottom of the last. Thus, the process of this invention can be utilized for shaping a shoe upper material and/or bonding shoe upper material to an insole. The process of this invention, as shown above, is free of hand operation during bonding and shaping, and can be affected Within a minimum period of time.

Though the above invention has been described with respect to a plurality of details thereof, it is not intended that this invention should be restricted thereby except to the extent provided in the claims.

I claim:

1. An apparatus for bonding a shoe upper to an insole, which apparatus comprises:

a shoe form having a sole portion and an upper portion, said form being adapted to retain an insole on said sole portion and to receive a sheet of shapeable shoe upper material in enveloping relationship of said upper portion thereof;

an enclosed box adapted to retain fluid under pressure;

an elastomeric sheet in one wall of said box;

a moveable support for said shoe form;

guide means for said support arranged in operable association With said box;

and means for moving said shoe form on said support into pressing contact with said elastomeric sheet to force the same into said box against the pressure of fluid maintained therein and thereby to cause said sheet to envelope said shoe form and upper material thereon.

2. A process for bonding a shoe upper to an insole which process comprises:

providing a shoe form having a sole portion and an upper portion;

positioning an insole on said sole portion;

positioning in juxtaposition with said upper portion a shapeable sheet of shoe upper material having marginal edges;

pressing said shoe form with said insole and upper material in place against one surface of a supported elastomeric sheet while applying fluid pressure to the opposite surface of said sheet;

continuing to press said form against said sheet to overcome the pressure applied to said opposite side thereof and thus causing said sheet to yield conformably to the shape of said form, to envelope the same, and to cause said marginal edges of said upper materials to overlie said insole on said form.

3. The process as defined by claim 2 in which an adhesive is applied to at least one of said insole and said marginal edges of said upper material and said adhesive is cured, or set, while said form is being pressed against said sheet.

4. The process as defined by claim 2 in which said upper material is formed substantially to the shape of said shoe form before being positioned on said form.

References Cited UNITED STATES PATENTS 761,356 5/1904 Burritt 128.1 878,572 2/ 1908 Squires. 1,261,959 4/ 1918 Reid 128.1 2,311,325 2/ 1943 Anderson 1233 2,489,643 11/ 1949 Hunter. 3,160,899 12/1964 Bille et a1.

PATRICK D. LAWSON, Primary Examiner.

US. Cl. X.R.

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