US3442743A - Box toe forming machine - Google Patents

Description

May 6, 1969 G. SCHULTZ ET AL Box llOE onmme MACHINE Sheet L of 4 Filed May 16, 1966 May 6, 1969 SCHULTZ ET AL 3,442,743

, BOX 'LTOE FORMING MACHINE Filed May 16. 1966 Sheet of 4 [FIG. 3

May 6, 1969 SCHULTZ ET AL 3,442,743 I BOX iTOE FORMING MACHINE Filed May 16. 1966 Sheet 6r 4 3H6 l I I4 y k 15" 1. 5*" I \Y m I 350 1 g/ l May 6,1 69 G. SCHULTZ .ETAL 3,442,743

Box a'ros FORMING momma Filed May 16, 1966 Sheet 014 I II I |5 5 H IF I G. 9 22 24 United States Patent US. Cl. 156-245 3 Claims ABSTRACT OF THE DISCLOSURE A method and machine are described for providing stifiening for a selected portion of an otherwise flexible material, as for example, a box toe for a shoe. A thermoplastic wafer is molded in the desired size and shape and then partially cooled so that its exposed surface remains tacky and while in this condition is pressed against the flexible material.

This invention relates to a method and machine for providing stiffening for a selected portion of an otherwise flexible material. In particular, it relates to a method and machine for formation of box toes in shoes.

In the construction and manufacture of shoes, it is a common practice to reinforce the toe end of the upper material to provide toe stiffness. Prior to this present invention, box toes were either preformed or formed in place from plastic or resinous material. Such preformed box toes require the shoe manufacturer to stock a wide variety of sizes and shapes to conform with the market which is normally difiicult to predict. To avoid this inventory problem, methods and machines have been described to form box toes in place in the shoe by means of resins or plastics, such as molten thermoplastic materials.

One commercial method and machine for forming box toes in position in a shoe involves the use of molten, thermoplastic adhesive material applied through a block which wipes the hot melt onto the selected surface area of the shoe upper to the desired thickness. In this method the material is then allowed to cool so as to harden. However, this method cannot be used with a mid-seamed vamp nor can it make crescent shapes. In addition, the resultant thermo-plastic box toe is slow to harden.

One object of this invention is to provide a rapid box toe forming machine and method which will yield box toes having a smooth exposed surface and which can be formed in any desired shape, including crescent shapes, and used with mid-seam vamps.

Other objects and advantages of this invention will be apparent from the description and claims which follow, taken toegther with the appended drawings wherein:

FIG. 1 is a perspective front view partially cutaway illustrating the initial step in the operation.

FIG. 2 is a partially schematic right elevation with partial cutaway and sectioning at the same stage of operation as FIG. 1.

FIG. 3 is a bottom view of the base of the mold.

FIG. 4 is a partially schemaitc right partial elevation showing the mold moved into position to receive the hot resin.

FIG. 5 is a plan view of the heated chamber.

FIG. 6 is a partial right side view with partial cross section showing the hot resin being forced up into the mold.

FIG. 7 is a partial right side view with partial cutaway and sectioning showing the resin-loaded mold in the process of returning and the excess resin being wiped off.

FIG. 8 is a partial bottom view of a portion of the resin-loaded mold.

Patented May 6, 1969 FIG. 9 illustrates the workpiece being clamped up against the resin-loaded mold.

FIG. 10 is a side view of a typical shoe upper showing the position of the adhered wafer of cooled resin which forms the reinforcing or box toe structure on the toe portion of the upper.

The invention comprises broadly first forming a thermoplastic wafer of the desired size and shape in a mcfld cavity open on one side, as in the general configuration of a punch. The mold has means for cooling the walls of the cavity. The portion of the wafer contacting the cool mold body is imediately solidified while the exposed surface of the wafer remains molten or tacky. The wafer, while still in its mold cavity, is then moved to alignment with a flexible work-piece such as a shoe upper and then pressed against the work-piece causing the wafer to strip from the mold and leave a smooth exposed surface of a wafer adhered to the work-piece.

The preferred sequence of operations comprises moving the mold to a position aligned with a resin supply opening so as to pick up the supply of hot thermo-plastic material. The loaded differentially cooled mold is then moved back so as to be aligned with the work-piece. By clamping, the differentially cooled material is pushed tightly against the flexible work-piece. Upon release of clamping the flexible work-piece retains the preformed, smooth-surfaced, attached resin wafer.

Referring now to the drawings, assembly 19 is shown having resilient pad 21 supporting a leather upper 22 and resting on base 20. A top curved clamping plate 24 is mounted on posts 23 which have lateral springs 27 connected to front posts 26. Clamping plate 24 leaves exposed the area 25 on the leather work-piece 22 where the resin wafer is to be applied.

The clamped work-piece assembly is placed in position so as to be aligned with the mold assembly. The mold assembly comprises a plate 11 supporting three posts 14 with post springs 15. Plate 11 is slidable in grooves 12 of frame 13. Mounted on posts 14 and vertically moveable through plate 11 is a top double plate 16. Plate 16 has a depending mold plate 116, a block containing mold cavity 216 having an open side for receiving the hot resin and a water chamber 316 for cooling that portion of the hot resin adjacent to the walls of the mold cavity 216. Cavity 216 is in the form of a curved wafer with a tapering leading edge.

The mold assembly 11-16 is moved horizontally by means of a horizontal piston 40 actuated by air cylinder means not illustrated. The cycle consists of the movement of the mold assembly 11-16 until it is aligned with the resin feeding apparatus. This resin feeding apparatus comprises a reservoir of hot resin 30, a pump 32, a check valve 33, an outlet conduit 34, and a resin supply chamber 31. When a hot resin charge has been fed through the resin supply to the mold, it strikes a spatter plate .131 within the resin cavity. The actual final forcing is accomplished by vertically operating piston 39. Holes 131a in the spatter plate 131 allow for back draining, while channel 36 is for overflow. Front wall 37 acts as a wiping means. When the charge of hot resin fills the recess 216, the surface adjacent to walls of the mold cavity is cooled to form a partially cooled, tacky wafer.

The mold assembly 11-16 is then moved back to its initial outward position by means of the piston 40. It is now in the loaded position ready to be imprinted onto the upper. This is accomplished by means of the upward action of bottom piston 39 in conjunction with the downward action of top piston 17 on the block containing the cavity 216. The partially cooled wafer has its exposed tacky portion pushed against the work area 25 and when the clamping pressure is relieved, the wafer is stripped and remains embedded on the Work area 25 of the upper,

Many materials may be used to form the wafer. Thus, a wide variety of both natural and synthetic resins and mixtures thereof are available which have the appropriate tensile strength, resilience and tack, and are solid at room temperature but fluid or molten at an elevated temperature, e.g. about 300 F. Resins having such properties are found in the classes of polymers known as linear copolyesters, polyamides and polyolefins. Further, resinous compounds have been described which are initially fluid but are hardenable by chemical means or heat. Such would also be useful in this invention.

We claim:

1. A process for stiflening a selected portion of a flexible sheet member comprising:

(a) feeding a charge of molten thermoplastic material into a mold having a recess with an exposed surface;

(b) cooling the mold to such an extent as to solidify the surface contacting the mold but not solidifying the exposed surface, thus leaving the exposed surface tacky;

(c) moving the mold containing the thermoplastic material into alignment with the selected portion of the flexible member;

((1) pressing the sheet member and mold together so as to secure the molded material onto the surface of the sheet member; and

(e) moving the mold away from the flexible member so as to strip it from the thermoplastic material.

2. The process of claim 1 wherein the flexible member is a portion of a shoe upper.

3. A machine for applying preformed shaped material to a workpiece, comprising:

(a) fluid material supply means,

(b) a mold having a recess adapted to receive fluid material from said means,

(c) means for cooling said mold recess so as to harden only a portion of the fluid material received in said means,

(d) means for moving said mold with the material in recess into alignment with the workpiece,

(e) means for pressing the mold and workpiece together so as to press the partially hardened material onto said workpiece, and

(f) means for moving said mold away from said workpiece, leaving said material adhered to said workpiece.

References Cited UNITED STATES PATENTS 2,444,931 7/1948 Heaton et al 3677 3,026,573 3/1962 Ciaio 3677 XR 3,316,573 5/1967 Chaplick et al. 3677 XR EARL M. BERGERT, Primary Examiner.

G. W. MOXON II, Assistant Examiner.

US. Cl. X.R. 156--498, 500

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