US2429233A - Collapsible last - Google Patents

Description

v. J. LEVAGGI, JR 2,429,233

Oct; 21,1947.

' COLLAPSIBLE LAST Filed May 25, 1946 Patented Oct. 21, 1947 COLLAPSIBLE LAST 7 Victor J. Levaggi, Jr., Beverly, Mass, assignor to United Last Company, Boston, Mass, a corporation of Maine Application May 25, 1946, Serial No. 672,282

Claims. 1

The purpose of the present invention is to provide improved means for connecting the forepart and the heel part of a two-part collapsible last of the type in which collapsing movement includes components of angular movement about a pivot in the forepart and angular movement about an individual pivot in the heel part. An example of a last in this category is illustrated in my United States Letters Patent No. 2,404,805, granted July 30, 1946.

The connecting means illustrated in the patent identified above possesses the desirable quality of resilience that enables .it to shift one of the parts (forepart or heel part) to its collapsed position and to its normal (last-forming) position from an intermediate point between those positions, and to draw the parts one against the other in their normal relation. For making the majority of shoes intended for street wear, especially the smaller and medium sizes, connecting means of moderate strength are entirely satisfactory, but for lasts used in making large heavy shoes, stronger connecting means are preferred.

To this end, the present invention provides connecting means that possesses relatively great strength and last-tightening ability without excessive weight and without requiring excessive weakening of the wooden parts of a last. A fea-- ture of the invention is an inverted toggle comprising a long link anda short link, one connected to the forepart by a pivot pin and the other likewise connected to the heel part by an individual pin, the short link being nested in a loop of the long link and on of the links having a knuckle seated in a recess in the other to form a kneejoint without a pin and without lapped portions. The loop of the long link is provided with an interior arcuate surface by which the kneeforming portions of the links are confined against radial displacement, and when the links are assem'bled in a last they are confined against axial displacement by the confronting walls of the kerf in which they are situated.

One of the links, preferably the long one, may be made to provide a factor of resilience in a lengthwise direction to render it contractile when it is abnormally extended and therefore capable of drawing the forepart and the heel part one against the other. Such contractile effect is use ful not only to resist movement of the knee-joint across its dead-center line but also to close the crack between a forepart and a heel part commonly caused by the buckling stress to which a last is subjected in some shoe machines, for ex ample, sole-leveling machines.

The drawings include a novel jack or stand provided with means for tripping the toggle and cocking it to lock the forepart and heel part of a last in their normal relation.

Referring to the drawings,

Fig. l is a side elevation of an inverted last embodying the invention, broken lines indicating the position of the forepart when the last is collapsed;

Fig. 2 is a longitudinal section of the last in which the toggle has been tripped;

Fig. 3 is a longitudinal section in which the last is collapsed;

Fig. 4 is a longitudinal section of the last in which the toggle is about to be cocked;

Fig. 5 is a sectional view indicated by line V-V in Fig. 4;

Fig. 6 is a perspective view of the links that provide an inverted toggle; and

Fig. 7 is an elevation, partly in section, of a.

jack or stand for operating the toggle.

The last comprises a forepart Iii and a heel part ii having counterpartal jointv surfaces including a ridge 12 extending widthwise on the heel part, and a Valley 13 in the forepart. When the ridge is nested in the valley it registers the parts In and I I in their normal relation and is effective also to sustain the buckling stress to which the last may be subjected in a sole-leveling machine.

A kerf It extends heightwise in the joint por tion of the forepart and intersects the valley It. A corresponding kerf l5 extends heightwise in; the joint portion of the heel part and intersects the ridge 52. Both of these kerfs are occupied by a long link it one end of which is connected to the forepart by a pivot pin ll. That portion of the link it which lies in the heel part includes a loop l8, preferably closed, in which a short link it! is nestered. These links are of equal thickness and are maintained in flush relation by the confronting parallel walls Zii, 20 of the kerf in the heel part which are spaced accordingly. A pivot pin 2| connects the short link and the heel part. The links and the pivot pins are so organized as to provide an inverted toggle, that is, a toggle that will draw the parts tightly one against the other when the pivot pins and the knee of the toggle are on their dead-center line or near the latter as in Fig. 1.

The knee of the toggle is formed in part by 'an outcurved end 22 of the short link and an interior incurved recess 23 in the loop IS. The end 22- constitutes a semi-cylindrical knuckle, and the recess provides a semi-cylindrical bearing surface for the knuckle without requiring any pivot pin in the knee-joint. The loop l8 also provides an interior arcuate surface 24 by which the short link is constrained to maintain its knuckle seated in the recess 23 without unduly limiting the relative angular movement of the links. The surface 24 is opposite the recess 23 and concentrically related to the center thereof. The space bounded by the loop l8 provides clearance for ashort range of angular movement of the links in one direction from their dead-center position (Fig. 1) to avoid accidental tripping of the toggle, and for a long range of movement in the opposite direction from that position to permit collapsing the last.

The pivot pins H and 21 are so located as to distort the loop 18 slightly and thereby stretch the link l6 when the knee of the toggle is on a line intersecting the centers of the pins. The reactionary force thus set up in the link 16 maintains the abutting surfaces of the forepart and heel part pressed tightly one against the other, and guards against accidental movement of the kneejoint across the pin line in both directions. The dead-center line of the toggle intersects the valley l3 only when the ridge I2 is nested therein. To provide for contractile action of the link Hi the latter is made of resilient steel and the portions 25 and 26 of the loop are curved and slender enough to be flexed slightly by the force developed by the toggle. A supplemental component of flexure is afforded by the crooked relation of the loop l8 and the offset portion of the link it connecting it and the pin ll, that portion being offset to one side of the direct line of tension.

To trip the toggle and thereby permit collapsing the last it is necessary merely to shift the center of the knee-joint across the pin line from the position represented in Fig. 1. That will place the links in the relation represented in Fig. 2. Once the toggle has been tripped, its knee-joint is left free to swing upwardly about the pivot pin 2| to release the forepart from the ridge 12 of the heel part. This release, in turn, permits the long link and the iorepart to be shifted to the positions represented in Fig. 3 in which the position of the iorepart corresponds to that represented by dotted lines in Fig. 1.

The jack or stand illustrated in Fig. '7 has provisions for tripping and cocking the toggle by swinging the long link about its pivot pin ll. The base 30 of the stand may be fastened to a bench with screws (not indicated). The upright portion 3| of the stand has a vertical bore to provide a step-bearing for a cylindrical spindle 32 to which a collar 33 is afiixed, This collar rests on the upper end of the step-bearing. Another collar 34 is fastened to the spindle by a pin 35, and is located below the bearing to prevent pulling the spindle out of the stand and to provide a small hole (not shown) to receive one end of a torsion spring 36. The other end of the spring is anchored to the stand 3i. The pin 35 projects through a segmental slot 3! in the stand to serve as a handle by which the spindle may be turned about its axis through an angle of about 60". The spring will normally return the pin 35 to one end of the slot.

.Above the collar 33 one side of the spindle is cut away for clearance. The spindle is thus provided with a semicylindrical portion 38 and an overhanging lip 39 adapted to be engaged by a trigger 48 formed on the long link IS. A steel socket or thimble 42 is embedded in the cone of the heel part to receive the spindle 32, and is provided with a slot 43 through which the trig er 40 may project to be engaged by the upper side of the lip 39 (Fig. 2) or by the lower side thereof 7 (Fig. 4) as the case may be.

A last, shod or unshod, may be collapsed as follows: if the toggle is cooked (Fig. 1) the trigger 40 will project into the socket 42 far enough to overlap any arcuate portion of the upper end of the spindle 32 that may extend across, or part Way across, the slot 43. The operator may establish the desired angular relation of the spindle and the last by turning one or the other before pressing the heel part toward the collar 33. Once the tip of the trigger is seated on the top of the spindle, it will temporarily arrest the descent of the last, but a moderate downward pressure on the heel part will overcome the resistance of the toggle and thereby shift the knee of the toggle across the pin line to the position represented in Fig. 2. The last may then be collapsed by shifting the forepart to the position represented in Fig. 3, in the course of which the trigger 40 will be retracted from engagement with the spindle and will consequently enable the heel part to drop to a seat on the collar 33.

To return the parts to their locked relation, with or without placing a shoe on the last, the first step is to place the forepart in its last-forming position (Fig. 4). This step will thrust the trigger 40 into the thimble 42, but at this stage the tip of the trigger will be below instead of above the lip 39. If, now, the heel part be lifted while the lip 39 overlies the trigger as in Figs. 4 and 5, the center line of the two pins I1 and 2| will be shifted across the center of the kneejoint of the toggle, and the latter will be thereby cooked to lock the parts as in Fig, 1. The final angular movement of the link It due to lifting the heel part will retract the tip of the trigger enough to enable it to clear the lip 39 and thereby release the last from the spindle.

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

1. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a loop in the heel part, a pivot pin connecting the long link and the forepart, the short link being nested in said loop, a pivot pin connecting the short link and the heel part, said loop and one end of the short link having semi-cylindrical bearing surfaces forming the knee of the toggle.

2. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link of equal thickness lying in flush relation, the long link occupying both of said kerfs and having a loop in which the short link is nested, a pivot pin connecting the long link and one of said parts, and a pivot pin connecting the short link and the other one of said parts, said loop and the short link having one a recess and the other a knuckle forming the knee of the toggle.

3. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link of equal thickness, the long link occupying both of said kerfs and having a loop in which the short link is nested, said loop and the short link having one a recess and the other a knuckle forming the knee of the toggle, a pivot pin connecting the long link and the forepart, and a pivot pin connecting the short link and the heel part, the confronting walls of said kerf in the heel part being spaced to maintain flush relation of the links.

4. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a resilient closed loop in which the short link is nested, a pivot pin connecting the long link and one of said parts, and a pivot pin connecting the short link and the other one Of said parts, said loop and the short link having one a recess and the other a knuckle forming the knee of the taggle, and said pins being located far enough from the joint surfaces to stress the links endwise when the knee is on the dead-center line of the pins.

5. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a loop in the heel part, a pivot pin connecting the long link and the forepart, the short link being nested in said loop, and a pivot pin connecting the short link and the heel part, said loop and one end of the short link having one a recess and the other a knuckle forming the knee of the taggle, and the space bounded by said loop providing clearance for a short range of angular movement of the links in one direction from their dead-center position and for a long range of such movement in the opposite direction from that position.

6. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, the heel part also having a passageway extending from its kerf to the top of its cone, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a loop in the heel part, a pivot pin connecting the long link and the forepart, the short link being nested in said loop, and a pivot pin connecting the short link and the heel part, said loop and the short link having one a recess and the other a knuckle forming the knee of the toggle, and the rear end of the long link being accessible to an instrumentality inserted into said passageway to operate the toggle.

'7. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a loop in the heel part, th short link being nested in said loop, the loop and the short link having one a recess and the other a knuckle forming the knee of the toggle, a pivot pin connecting the long link and the forepart, and a pivot pin connecting the short link and the heel part, the cone of the heel part having a socket and the rear end of the long link being movable in said socket to cock and trip the toggle.

8. A two-part collapsible last comprising a forepart and a heel part having oblique abutting joint surfaces and each having a kerf extending heightwise in its joint portion, the joint end of the heel part also having a ridge extending widthwis thereof and the forepart having a counterpartal valley to receive the ridge and thereby register the parts in last-forming relation, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a loop in the heel part, the short link being nested in said loop, a pivot pin connecting the long link and the forepart, and a pivot pin connecting the short link and the heel part, said loop and the short link having abutting surfaces forming the knee of the toggle, said links and said pins being arranged to locate the dead-center line of the toggle in a plane intersecting said valley when said ridge is nested in said valley.

9. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a loop in the heel part, a pivot pin connecting the long link and the forepart, the short link being nested in said loop, and a pivot pin connecting the short link and the heel part, said loop and one end of the short link having one a recess and the other a knuckle forming the knee of the toggle, and the loop also having an interior arcuate surface in concentric relation to the axis of said knee and arranged to engage the other end of the short link to maintain cooperative relation of the knee-forming elements.

10. A two-part collapsible last comprising a forepart and a heel part having abutting joint surfaces and each having a kerf extending heightwise in its joint portion, an inverted toggle comprising a long link and a short link, the long link occupying both of said kerfs and having a closed loop in the heel part, a pivot pin connecting the long link and the forepart, the short link being nested in said loop and having an outcurved end an interior incurved recess in which said knuckle is seated to form the knee of the toggle, and a pivot pin connecting the short link and the heel part, said loop also having an interior arcuate surface opposite said recess and arranged to maintain the knuckle of the short link in the recess.

VICTOR J. LEVAGGI, JR.

forming a knuckle, said loop having I

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