US2023712A - Hinged last - Google Patents

Description

F. W. STUART Dec. 10, 1935.

Filed April 9, 1934 @6370 may;

Patented Dec. 10, 1935 UNITED STATES PATENT OFFICE HINGED LAST Fred W. Stuart, Beverly, Mass, assignor to Maxwell A. Stuart, Beverly, Mass.

Application April 9, 1934, Serial No. 719,664

2 Claims. (Cl. 12-136) This invention relates to hinged lasts and its [4. It is also provided with a forwardly projectobject is to provide a last of this type which shall ing curved hinge element It which, it will be be rigidly supported in expanded position by a understood, extends for the full width of the heel metallic link against heavy pressure exerted part. The toe part I8 is provided with a correupon the tread face of the shank of the last in spondingly shaped concave socket 20 interfitting various shoemaking operations, such, for examwith the surface of the hinge element It. This ple, as sole leveling. I have discovered that a link hinge connection between the two parts of the may be secured in the heel part of the last so last permits relative pivotal movement thereof that it will swing through a limited arc, correabout a fixed axis coinciding with the center of 1c sponding to the collapsing movement of the last, curvature of the interfitting faces. The hinge l0 and be positively arrested in both of its limiting element I6 of the heel part is provided with a positions by cooperating anchor pins, so that the transverse anchor pin hole at this center of curvlink acts as a rigid strut or cantilever beam for ature. When the last is in expanded position, the support of the toe part of the last. Pressure the tread surface of the heel part and the tread on the tread face of the toe part of the last may surface of the toe part coincide, as do the lower 15 thus be resisted as a longitudinal stress in the edges of these two parts, as shown in Fig. 1, link and a shearing stress upon the anchor pins, and when the last is moved into collapsed posiinstead of tending to break down cooperating tion these edges are separated, as shown in Fig. 4. wooden faces or pull out wood screws from hinge The adjacent faces of the wheel and toe parts parts. It will thus be seen that by the construcof the last are slotted or grooved in registration 20 tion of my invention I am enabled rigidly to with each other to receive a metallic link 22 support the two parts of the last in the relative which holds them together while permitting the position which they assume either in expanding pivotal movement already explained. The link 22 or in collapsing the last. is provided with an intermediate transverse slot 25 Preferably and as herein shown, the connect- 24 which is located in line with the axis of move- 50 ing link of my improved last is provided with a ment of the last parts and through which passes spring element which tends at all times to pull an anchor pin 32 which is set in the heel part the last parts forcibly toward each other, thus H] of the last. At its rear end the link 22 is tending to take up wear which may develop over provided with an open ended slot 26, the inner an extended period of use and at the same time end of which forms a hole for the reception of 30 to set up and maintain a degree of frictional a second anchor pin 3|] which extends through engagement between the two parts of the last the heel part in a position at the rear of the sufficient entirely to obviate accidental displaceanchor pin 32. The slot 26 is enlarged at its outer ment thereof and to hold the parts in either exend and provided with oppositely disposed re- 35 panded or collapsed condition, as desired by the oesses which constitute a socket for a plurality 35 workman. of transverse spring leaves 28. These are piled These and other features of the invention will up in superposed relation, or in a pack, and be best understood and appreciated from the folslipped transversely into the socket in the link 22 lowing description of a preferred embodiment thus provided. They close the inner end of the thereof, selected for purposes of illustration and slot 26, thus forming ahole for the reception of 40 shown in the accompanying drawing, in which the anchor pin 30, and they are free to be bowed Fig. 1 is a view of the last in side elevation with rearwardly into the open end of the slot 26 by portions broken away to expose the hinge conthe pressure of the anchor pin 30. At its forstruction; ward end the link 22 is connected to the toe part Fig. 2 is a sectional view on the line 2-2 of [8 of the last by an anchor pin 34. 45 Fig. 1; It will thus be seen that the link 22 is pivotally Fig. 3 is a view in perspective of the conconnected adjacent to its opposite ends by the necting link; anchor pins 3|] and 34 to the heel and toe parts Fig. 4 is a sectional view showing the hinge respectively of the last. In all positions of these parts in the collapsed position of the last; and parts, the spring leaves 28 are maintained under 50 Fig. 5 is a similar view showing an intermediate stress and tend, therefore, powerfully to pull the position of the last parts. two parts of the last toward each other, that is,

The heel part I0 of the last is herein shown the spring leaves 28 react against the anchor pin as provided with the usual comb plate l2, of 30 to pull the anchor pin 34 rearwardly. The link fibre or the like, and the usual metal heel plate thus acts to maintain at all times an appreciable 55 in the shoemaking process and this pressure tends to break the back of the last about the tread face edges as a fulcrum. It will be seen that such other words, the leveling pressure on the shank" of the last tends to separate the pins 34 and 32 but this separating movement is positively resisted in the link 22 by the engagement of the pin 32 with the side wall of the slot 24.

There is a special relationship between the end of the transverse slot 34 and the anchor lock pin 32 when the last is in expanded position. In general use it sometimes happens that the meeting edges of the two portionsof the last at the tread face become battered or upset in use. As herein shown, the end of the slot 24 lies just far enough beyond the pin 32 in the normal expanded position of the last to actas a reinforcement or as a positive limit stop in case any such deformation of these meeting edges should occur. This action of the anchor lock pin in cooperation with the end of the slot 24 is in addition to its function already explained in bearing against the side wall of the slot so that the forward portion of the link acts as a solid inextensibleconnection resisting movement of the last parts in a direction to break the back of the last.

' Ithas been explained that the spring leaves 28 are maintained at all times under tension. It will be observed that the position of maximum tension in the spring leaves corresponds to the position of the last parts shown in Fig. 5, wherein the three anchor pins are arranged in'a straight line. In this position there is the maximum distance between the anchor pins 30 and 34. k This distance decreases slightly as the forepart is moved either into expanded position, as shown in Fig. 1, or collapsed position, as shown in Fig. 4.

The natural tendency of the springs is, therefore, to maintain the last in one condition or the other, which is very desirable from the standpoint of the manufacturer.

My improved last may be assembled with great accuracy and convenience in manufacture. Having assembled the spring leaves 28 in the link 22, the latter is slipped into its groove or slot in the parts of the last and then the anchor pins 30, 32 and 34, which, as shown in Fig. 2, are provided with taper ends, are driven into place. In this operation the spring leaves 28 are deflected, as already explained, the frictional engagement of the last parts is established and the curved faces of the last parts are maintained at all times under continuous and substantial pressure of engagement.

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

1. An improved last comprising toe and heel parts having cooperating curved faces shaped to permit said parts to swing on each other, and a. metal connecting link having a longitudinal slot in one end and a circular hole in the other, a

' pack of superposed spring leaves located in the link and extending transversely across the outer end of said longitudinal slot, and a pin having a taper end which has been forced through one part of the last and said slot to flex said pack as a whole and maintain the leaves thereof flexed at all times, thereby holding the curved faces of the last parts under continuous and substantial pressure.

2. An improved last comprising fore and rear the last and the slot to flex said pack as a whole 45 and maintain the leaves thereof flexed at all times, thereby holding the curved faces of the last parts under continuous and substantial pressure in all positions thereof.

FRED W. STUART.

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