US3091813A - Shoe forms - Google Patents

Description

June 4, 1963 G. E. WALKER 3,091,813

SHOE FORMS Filed April 21, 1961 I nvenior Gordon F VaZher By his flzzforney 3,091,813 SHOE FORMS Gordon Ernest Walker, Leicester, England, assignor to United Shoe Machinery Corporation, Flemington, N..l., a corporation of New Jersey Filed Apr. 21, 1961, Ser. No. 104,706 1 Claim. (Cl. lit-46) This invention relates to shoe forms and is herein illustrated in its application to composite or foreshortening shoe forms intended primarily for use in machines for vulcanizing outsoles onto shoe bottoms, such a machine being disclosed in an application for United States Letters Patent Serial No. 781,138, filed December 17, 1958, now Patent No. 3,058,152, on an application filed in the names of Eldred and Frampton.

Machines for vulcanizing outsoles onto shoe bottoms are commonly provided with foreshortening shoe forms for supporting lasted shoes for the sole Vulcanizing operation. In such a shoe form the heel end portion is commonly movable with relation to the forepart. In its extended or shoe supporting position the heel end portion must be adequately supported against return movement to resist the heavy pressure applied to the shoe form in the vulcanizing operation.

It is an object of the present invention to provide an improved foreshortening shoe form suitable for use in sole vulcanizing machines which is convenient to operate, relatively inexpensive to manufacture, and provides adequate support for the shoe during the vulcanizing operation.

With the above object in view, the present invention consists in the provision of a composite shoe form comprising a forepart, a heel block and means mounting the heel block for movement relatively to the forepart between a shoe form foreshortening position and a shoe form extending position. The heel block is provided with a headed stem which moves axially to transfer the heel block between the foreshortening position and the extending position. The advancement of the heel form in its extended position is effected in two stages, first by the straightening of a toggle mechanism comprising an arm and a link and finally by the operation of a cam incorporated in the arm and arranged to engage the head of the stem. In order to provide for the cam operation the arm is connected to the link by a pin and slot arrangement in which the width of the slot is greater than the diameter of the pin. In the operation of the earn the pin is disengaged from the bottom wall of the slot so that a thrust exerted against the extended heel block is taken by the cam and not by the pin. The slot is extended lengthwise to permit a return movement of the arm relatively to the link thereby to disengage the cam from the head preparatory to the operation of the toggle mechanism to move the heel block from its extended position to its foreshortening position.

The invention will now be described with reference to the accompanying drawing and pointed out in the appended claim.

In the drawing:

FIG. 1 is a side elevation illustrating a shoe form embodying the features of the present invention, a portion of the form being broken away in order to illustrate parts of the interior structure; and

FIG. 2 is a side elevation similar to FIG. 1 showing the heel portion of the form in its retracted position.

The illustrated shoe form is constructed for use in machines for vulcanizing outsoles onto shoe bottoms, such a machine being disclosed in the Eldred et al. application for United States Letters Patent hereinbefore referred to.

The illustrated shoe form is a composite structure rates Patent comprising a forepart 10 and a heel block 12. Extending upwardly from the forepart is a superstructure 14 whereby the shoe form is mounted in a vulcanizing machine. The heel block is positioned in a recess formed in the rear end of the forepart. The recess has a flat bottom 16 inclining downwardly toward the toe end of the forepart, and a convex wall 18 extending upwardly with a toeward inclination from the bottom face of the forepart and providing a bearing for the concave forward surface of the heel block. The heel block is secured to a stem 20 by a pin 22, said stem extending upwardly with a toeward inclination from the heel block through a bore 24 extending from the bottom surface 16 of the recess into the superstructure 14-. Formed in the upper portion of the stem 20 is a head 26. When the shoe form is extended, the heel block is in its position illustrated in FIG. 1 with its bottom surface conterminous with the bottom surface of the forepart 10. This position of the heel block is determined by the engagement of the head 26 with the base of a counterbore 23 formed in the superstructure.

For transferring the heel block from its shoe form foreshortening position in FIG. 2 to its shoe form extending position illustrated in FIG. 1, an actuator herein illustrated as a hand lever 39 is fixed to a shaft 32 journaled in a bearing 34 mounted in the superstructure and extending widthwise of the shoe form. In the illustrated organization the actuator is operatively connected to the stem 2819 by a toggle mechanism comprising an arm 38 secured to the shaft 32 and positioned in a cylindrical cavity 36 coaxial with the shaft and a link 40 connecting the arm to the head 26 of the stem 26 The lower portion of the link is inserted into a suitable notch in the head 26 of the stem and is bored to receive a pivot pin 42 mounted in the head. For connecting the link 4 to the arm 33 the link carries at its upper end a pin 44 extending forwardly into an arcuate slot 46 formed in the arm 38 and disposed in concentric relation to the shaft 32. The greater part of the advancement of the heel block from its position in FIG. 2 into its position illustrated in FIG. 1 is effected by the toggle action of the arm 33 and the link 40, but the final increment of movement of the heel block into its position illustrated in FIG. 1 is effected by a cam action of the arm 38 against the head as of the stem 20'. To this end the lower extremity of the arm 33, as seen in FIG. 1, has formed therein a cam face 48 which bears against the top of the head 26 during the final stage of the counterclockwise movement of the arm into its position illustrated in FIG. 1. During the final stage of movement of the heel block into its position illustrated in PEG. 1 the cam action of the arm 38 on the stem 20 causes the pin 44 to be seated against the then lower wall of the slot 46, leaving a slight space between the pin and the upper Wall of the slot and insuring an arrangement of the op erating parts whereby the force of the vulcanizing operation exerted upon the heel block 12 is taken by the arm 38 and not by the pin 44. A stop pin 59 is mounted in the base of the cavity 36 to determine the position of the arm 38 during the vulcanizing operation.

The retraction of the heel block from its position in FIG. 1 to its position illustrated in FIG. 2 is effected by movement of the hand lever 36 in a clockwise direction from its position in FIG. 1 to its position in FIG. 2. During the first stage of the operation of the hand lever the arm 38 moves across the head 26 of the stem 20' while the link 44 remains stationary in its position illustrated in FIG. 1. This continues until the right end wall of the slot 45' engages the pin 44. By this time the cam face 48 has moved away from the head 26 permitting the retraction of the heel block by continued movement of the hand lever 30 into its position illusthereon and the return of the heel clock to its position illustrated in FIG. 1 locates it to support the heel portion of the shoe for the vulcanizing operation.

Having thus described my invention, what 1 claim as new and desire to secure by Letters Patent of the United States is:

A composite shoe form comprising .a forepart and a heel blocrt having mutually contacting surfaces on which said parts are relatively slidable along a path inclined relatively to the longitudinal axis of the shoe form, a headed stern extending from the heel block, means mounting the stem for axial movement to transfer the heel block along said inclined path between a shoe form foreshortening position and a shoe form extending position, toggle mechanism comprising an arm axially mounted for swinging movement and a link for partially advancing the heel block from its shoe form foreshortening position to its shoe form extending position, a cam incorporated in 4 the arm and constructed and arranged to engage the head of the stem thereby to complete the advancement of hte heel block into its shoe form extending position and a pin and slot connection between the arm and the link in which the width of the slot is greater than the diameter of the pin and the slot is in the form of an arc struclcfrorn the axis of the arm and extended to permit a movement of the arm relatively to the link to disengage the cam from'the head preparatory to the operation of the toggle mechanism to move the heel block from its extended position to its foreshortening position, the operation of the cam serving also to efiect a relative movement of the pin and the slot widthwise of the slot 7 such that a thrust exerted against the. extended heel block is taken by the cam' and not by the pin.

References (Iited in the file of, this patent UNITED STATES PATENTS 1,890,042 Morandi Dec. 2, 1932 2,566,686 7 Ulcek Sept. 4, 1951 V FOREIGN PATENTS 1,102,2s0 France Oct. 18, 1955 1,086,152 Germany July 28, 1960

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