US2365795A - Method of making back parts of shoes - Google Patents

Description

Dec. 26, 1944. M F ASHLEY 2,365,795

METHOD OF MAKING BACK PARTS OF SHOES Filed Sept. 28, 1942 Patented Dec. 26, 1944 UNITED STATES PATENT .OFFICE Merwin F. Ashley, Arlington, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. J a corporation of New Jersey Application September 28, 1942, Serial N 0. 459,926 9 Claims. (01. 12-146) This invention relates to methods of forming the back parts of shoe uppers and more particularly to the preshaping of the back parts prior to their assembly with other parts of a shoe on a last.

One of the principal diiflculties encountered in theshaping of back parts of shoe uppers resides in the formation of the flange around thesharp- 1y curved heel-end portion of the work without causing wrinkles in the back part due to the heavy pleats made in the flange. One of the most common methods proposed for eliminating these objectionable wrinkles comprise corrugating the material forming the lower marginal portion of the back part before subjecting this marginal portion to the flanging wipers of a molding machine. takes place either simultaneously with or following the molding to finished shape of the back part above the lasting margin. corrugating of the marginal portion prior to the flanging operation facilitates the subsequent flanging operation, it does not completely eliminate the formation of wrinkle in the back partafter the formation of the flange. One reason for this i! that the methods heretofore employed for corrugating the margin of the back art have the effect of stretching the material at the margin, thereby creating a greater bulk of marginal material to be flanged at the heel seat without reducing to any perceptibledegree the thickness of the pleats and Without eliminating the objecionable wrinkles. Another reason is that the formation of corrugations in the lasting margin before the flange is turned does not result in a uniform distribution of the surplus stock of the flange around the extreme heel end when the flange is turned, so that large pleats extending to the edge crease are formed, which result in' wrinkles in the surface of the back part above the edge crease.

- It is an object of the present invention to provide an improved method of forming back parts of shoe uppers which overcomes the disadvantages of the prior methods as outlined above.

To this end and as a feature of the present invention, the flange is turned. substantially at a right angle to the body of the flat blank before any molding of the blank, after which the flange is progressively corrugated around that portion which is to form the extreme heel end portion of This treatment of the margin usually Whereas this edge and causing the blank to curve at the corrugated portion sothat it assumes somewhat the general'shape of a finished back part. The back part thus flanged and corrugated is then in condition to be molded into final shape. By subjecting the flange of the back part to the corrugating operation while the back part is in a flat tened condition, it is possible readily to corrugate the flange progressively and thus toforeshorten the flange without stretching the material of which it is formed. Moreover, the pleats which must be formed in the flange of the finally molded back part are readily confined to the flange and do not extend beyond the edge crease when the back part is formed by this method.

. The above and other features of the invention will now be described with reference to the ac; companying drawing and pointed out in the claims.

In the drawing,

Fig. 1 is a view of a flat back-part blank assembly undergoing a flanging operation;-

Fig. 2 is a vertical section through one form of apparatus by which the flange of the backpart assembly may be progressively corrugated;

Fig. 3 is an end view of the corrugating members shown in Fig. 2;

Fig. 4 is a perspective view of a back-part assembly formed in accordance with my invention as it appears after the corrugating operation;

Fig. 5 is a perspective view, partly in section, of

members between which the assembly of Fig. 4

the back part in such a manner as to shirr the may be molded into final shape; and

Fig. 6 is a view of a completed back part.

In carrying out the improved method, a flat back-part blank is first formed by assembling a piece of upper material U (Fig. 2), a lining L, and a counter stifiener C, which may be adhesively secured together to form a back-part blank B. The upper and lining may further be secured together around their top edges by a line of stitching S. The flat blank is then flanged in anysuitable manner as by passing it between a pair of rolls [0, l2 as shown in Fig. 1. The roll I! may have a V-shaped periphery into which the back part is pressed by the roll l0, thereby progressively to form a flange F and an edge crease [3. It will be understood that any other suitable means may be employed for forming the flange. It may well be noted here that the even crease l3 formed in flangin the flat blank is maintained throughout the subsequent forming operations and ultimately defines the edge crease at theheel end portion of the completed shoe.

After the flange is turned, corrugations are As illustrated herein, this corrugatlngmecha'-' nism comprises a pair of toothed corrugating rolls I4 and I6 mounted on shafts I8 and respectively which are disposed at a slight angle to each other.

'The teeth I! of the rolls I4 and I6, by reason of this angular relationship of the supporting shafts, overlap more at their inner ends than at their outer ends, so that the depths of the corrugations formed in the flange decrease inwardly from the edge of the flange.

The shaft I8 is journaled in the upper end of a frame 22 in the lower portion of which is journaled a drive shaft 24. The shafts I8 and 24 are connected by a sprocket chain 26 passing over sprockets secured to the shafts, and a pulley 28 on the shaft 24 is connected by a belt 30 to a suitable driving means. The shaft 20 carrying the roll I6 is journaled in an arm 32 pivoted at 34 to the frame 22. A spring-pressed plunger 36 supported in the frame 22 acts upon the arm 32 normally to move the arm upwardly about the pivot 34, thereby to move the roll I6 away from the roll I 4. A treadle rod 38 connected by a cable 40 to the arm 32 is provided for moving the arm downwardly against the force exerted by the spring-pressed plunger 36 to bring the corrugating rolls into operative relationship. The rearward ends of the shafts I8 and 20 carry gears 42 and 44, respectively, which are in constant meshing engagement so that the roll I3 rotates continuously with the roll I4. Thus, there is no danger of clashing of the teeth of the rolls when the roll I6 is moved into operative relationship with the roll I4. The axis of the pivot 34 between the arm 32 and the frame 22 passes through the pitch circles of the gears so that they may remain in constant engagement as the arm 32 is swung about its pivot. Suflicient clearance is provided between the teeth of the gears to permit this movement of the arm. .A stop 46 of the frame 22 cooperates with the arm 32 to limit its upward movement by the plunger 36.

Preferably the flange F of the back-part blank is corrugated only around the heel-end portion as between lines a and b of Fig. 4. With the rolls I4 and I6 in their normally separated positions the flange of the back part is inserted between the rolls with that portion at line a (Fig. 4) in position to be engaged by the teeth I! when the rolls are brought together. The operator now depresses a treadle (not shown) to exert a downward pull on the rod 38, thereby to move the roll I6 into operative relationship with the roll I4 and, with the rolls continuously rotating, the flange will be corrugated progressively and fed automatically. After the flange has been corrugated around to the line b, the treadle is released, thereby allowing the roll I6 to be moved upwardly by the plunger 36, whereupon the back part may be removed from the machine. By thus corrugating the flange, one tooth at a time between the rolls, the corrugations are formed in a manner to distribute the surplus stock of the flange uniformly about the extreme heel end without the creation of large pleates extending to the edge crease and therefore there are no pleats at the edge crease to extend as wrinkles into the surface of the back part normally exposed in the shoe.

The back part appears as illustrated in Fig. 4 after thus being operated upon by the mechanism of Fig. 2. The inner edge of the margin is considerably foreshortened by the corrugations formed therein so that that portion of the back "part adjacent to the corrugated portion of .the 1 flange assumes a substantially circular form. A

well-defined edge crease has been formed by the previous formation of the flange F and, inasmuch as the depth of the corrugations decreases inwardly from the edge of the flange and terminates short of the edge crease, no wrinkles are formed in that portion of the back part which is exposed inthe finished shoe. Inasmuch as there has been no stretching of the materials forming the flange, there is not an excessive amount of material in the flange and the flange may be readily molded by a subsequent molding operation.

The back part is now ready for conformation to final shape. This may be accomplished by means of either a back-part molding machine or a heel-seat lasting machine. Where a back-part molding machine is employed, inner and outer mold members 48 and 56 (Fig. 5) are arranged to act upon opposite sides of the back part to mold it under heavy pressure to final shape.

The machine illustrated in Letters Patent of the- United States No. 2,342,154, granted February 22, 1944, upon an application filed in the name of L. S. Macdonald, is well suited for this purpose. During the molding of the back part the flange F is held in place on the heel-seat portion of theinner mold 48 by a pair of wiper plates 52, only one of which is illustrated herein. By thus holding the back part on the inner mold the danger of destroying the edge crease is substantially eliminated and after heavy pressure has been applied to the back part by the inner and outer molds, molding pressure may be applied to the. 5 flange F by forcing the wiper plate 52 and the inner mold 48 together as described fully in the Macdonald patent. The main function of the mold members 48 and 50 of Fig. 5 is to impart the proper heightwise curvature to the back part and to mold the wing portions so that they will properly conform tothe shape of a last. It will thus be seen that a large portion of the work normally done by the molding machine is effected by the foreshortening action of the corrugating rolls on the flange during the corrugatlng operation and that this action takes place without creating an excessive bulk of marginal material at the heel-end portion of the flange which might tend to create wrinkles in the exposed portion of the back part.

When a heel-seat lasting machine is relied upon to accomplish the .final molding operation the back part inthe form of Fig. 4 assembled on a last is presented thereto. In such case, the effort. required on the part of the wipers of they lasting machine is minimized and the preformed flange F corrugatedv as described above assists in the proper assembly of the back part on the last.-

Whichever machine is used to perform the final molding operation, the preformed flange serves to assist in positioning the back part on the mold or last in the correct heightwise relationship with I respect thereto, and thereby insures the correct height of the back part in the finished shoe.

However the final molding is accomplished, the result is the same, namely, the formation of a back part molded to final shape, characterized by having a well-defined edge crease and a uniformly pleated flange, the pleats of which terminate short of the edge crease so that no wrinkles are formed in the surface of the backpart normally exposed in the finished shoe. This result is obtained by turning the flange of the flat back part to form a well-defined edge crease after which the flange is foreshortened around the extreme heel end by progressively forming corrugations therein and confining the corrugations to the flange so that no wrinkles extendacross the edge crease into the exposed surface of the back part i above the edge crease.

While the formation of the corrugations has been described as being accomplished without stretching the materials of which the flange is formed, it will be apparent that, even by progressively corrugating the flange, the ductility of the materials may be such that some slight stretching of the fibers takes place. Accordingly, where the flange is described herein as being corrugated without stretching the materials, this should be understood to mean relatively little stretching as compared to the amount that the materials are stretched in prior methods in which all the corrugations are formed simultaneously before the flanging operation.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in methods of forming back parts of shoe uppers which comprises forming a crease line in a flat back-part blank by turning the lower marginal portion of the fiat blank to form an attaching flange, and then forming the blank to final shape while'maint'aining said crease line which thus becomes the edge crease around the heel end of the finished shoe.

2. That improvement in methods of forming back parts of shoe uppers which comprises assembling an upper, a lining and a counterstiffener to form a flat back-part blank, turning the marginal portion of the flat blank to form an attaching flange defined by a crease line, and molding said blank into final shape while maintaining said crease line to form the edge crease around the heel end of the finished shoe.

3. That improvement in methods of forming back parts of shoe uppers which comprises flanging the lower marginal portion of a flat backpart blank and then imparting a curved shape to theblank by corrugating the flanged portion.

4. That improvement in methods of forming back parts of shoe uppers which comprises flanging the lower marginal portion of a flat back-part blank and then progressively corrugating the flange to foreshorten it and cause the blank to assume a curved form.

5. That improvement in methods of forming back parts of shoe uppers which comprises flanging the lower marginal portion of a flat backpart blank and then imparting a curved shape to the heel end portion only of the blank by corrugating the flange around said portion Without materially stretching the substance thereof.

6. That improvement in methods of forming back parts of shoe uppers which comprises flanging the lower marginal portion of a flat backpart blank, then imparting a curved shape to the blank by progressively corrugating the flange portion, and finally molding the blank to final shape.

7. That improvement in methods of forming back parts of shoe uppers which comprises forming a series of corrugations in the flange of a flat flanged back-part blank the depths of the corrugations decreasing inwardly from the edge of the blank, thereby to foreshorten the flange and cause the blank to assume a curved form.

8. That improvement in methods of forming back parts of shoe uppers which comprises flanging the lower marginal portion of a flat backpart blank, progressively forming corrugations in the flange at the heel-end portion of the blank, the depths of which decrease inwardly from the edge of the flange, thereby to foreshorten said portion of the flange to impart a curved shape to said heel-end portion of the blank.

9. That improvement in methods of forming back, parts of shoe uppers which comprises flanging the lower marginal portion of a flat back part blank, progressively forming corrugations in the flange at the heel-end portion of the blank, the depths of which decrease inwardly from the edge of the flange, thereby to foreshorten said portion of the flange to impart a curved shape to said heel-end portion of the blank, and molding the blank substantially to flnal shape.

MERWIN F. ASHLEY.

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