US1743618A - Last - Google Patents

Description

Jan. 14, 1930. o. A. PETERSON LAST Filed Sept. 18, 1923 2 Sheqts-Sheet 2 Dzvezzlvir Oil/0111950211100 having bearing Patented Jan. 14, 1930 UNI-TED s'rAres OTTO A. -PETERSON, OF STOUGI'ITON,

BELCHER COMPANY, OF STOUGHTON, CHUSETTS j MASSACHUSETTS, ASSIGNOR TO GEORGE E. MASSACHUSETTS, A CDRPORATION MASSA:

LAST

Applieation fil ed September 18, 1923. Serial No. 663,468.

My present invention relates to certain further improvements in divided lasts and particularly in such as have a snap or tendency to stay set in either their open or closed position. This has been accomplished genorally in two manners, i. e. by the overriding of an intermediate resisting of wedging surface or by the shifting of'lines of force relative to an actual or an'imaginary center of rotation as in my own' prior Patent No. 1,195,266 which involved however certain other principles of construction important in this art. 7 I I 'My present invention contemplates a combinational relation in which the obstructive or resisting surface principle is coinbined with my'own principle of elastic linkage whereby the advantages of the former are preserved while avoiding the obvious impossibilities of mechanical compression of the wood itself. I further contemplate certain advantageous combinations in the knuckle curvature by which I am able to accomplish a maximum of efficiency with a simplicity of structure which makes manufacturing on a commercial basis possible.

As illustrative of the principles of my invention I have shown in the accompanying drawings two forms of the many. These.

are to be considered largely as illustrative but are both capable of manufacture as commercial factory lasts. Throughout specification and drawings like reference characters .are employed to indicate corresponding parts, and in the drawings;

ig. l is a side elevation of alast in accordance with my invention.

Fig. 2 is a sectional View of the same in extended position.

Fig. 3 a similar View in broken position.

Fig. 4 an enlarged diagrammatic view showing the knuckle curvatures.

F ig. 5 a central vertical section through I another form of my last in extended position. and

Fig. 6 a similar View in broken position. i

It will be seen that my last comprises a fore part 1 and heel part 2 of usual type an intermediate knuckle joint or wh ch w l be d cu sed fu ther ridden the edge of later, the said parts being kept together and the bearing maintained bya U-s'haped link 3 pivoted at one end in the fore part 1 at the knuckle center 4 and atits rear as at 5 in the heel part1 p p This U-shaped link as set forth in my prior patent isof flatstock and has a slight resiliency. Working in the narrow slots 1 and 2 it affords a steady bearing and takes up lateral strains while constantly holding the two parts snugly together. V 1

The knuckle joint as will be seen by reference to Fig. 4 comprises two portions 6 and 7. The portion 6 is-struck on a true radius from the pivot center 4: and terminates in'a horizontal shoulder 8... The joint is continuedbelow this shoulder in a sinuous or undulating surface, the upper portion 5 7 being formed-as a projecting cam surface, and the lower portion 7 2 being reversely concaved. "This leaves the face of the heel part with a portion 2? conforming to the portion '7 which in the breaking of the last rides up over the portion 7 until it assumes the position shown in Fig.3 in which it has overthe shoulder 8. As ap peers in Fig; 2, the shoulder 8 constitutes a stop and being horizontallydisposed it has no resistantaction to the longitudinal tendency of the spring to pull the parts together but combined with the interlocking action of the faces 7 and 2 it has a verystrong holding action'in steadyin the last during the levelin up of the shoe. I

V This form of joint therefore provides for the two positionsof the last parts and their retentionby a snapping action of the last without any wearing of the resisting or wedging surfaces of theknuckle inasmuch as the link3 yields to permit the passage of the parts. p V

WVhilethis form of joint has many advan, tages' the, shoulder 81 may in some cases be omitted as appears in Figs. 5 and 6. In these figures the knuckle portion 6" is a cylindric ongthe fore part 1 struck onthe pivot 4 of the forward'end of the link as acentral axis but mergesat the point 7 into a reversed curvature which leaves a cam sh p p n 10 the e p rt which.

must ride over the surface 6 when passing the point 7. In so doing the link 3 yields as before to permit the camniing action of these parts. I

Such lasts are not only convenient to make and to operate but are long lived and convenient to manufacture. The positioning of the pivot pin at in the central axis of the knuckle facilitates andsimpliiies the sawing of the knuckle joint in dividingv the last and gives the pivot pin 4 an advantageous position both as a central axis of rotation of the heel part on the fore part and as regards the opposite pin 5 of the link and the line of force resultant from the resiliency of the link which is directed between them. It will be seen that in each position of the link this line of force is directed from the hee part dii' ectly'towards the pin 4 as a center of rotation and although the link stretches slightly during the passing of those portions of the knuckle surface which have a camming action, its tendency is in both broken and extended position to hold the, last in the position desired.

Various modifications in the construction and operation of my device may obviously be resorted to all Without departing from the spirit of my invention if ithin the limits of the appended claims.

What I therefore claim and desire to secure by Letters Patent isz- 1. A divided last comprising a fore part and a heel part having intermediate cooperating bearing surfaces, a resilient connecting link connected at oneend in the forepart and at the other end in the heel part to press said bearing surfaces together, said surfaces having engaging portions including an eccentric and a concentric portion subjected to the pressure exerted by said resilient link whereby to. maintain the last parts in yielding engagement, and to be yieldingly resistantto movement from the extended position by reason of the eccentric position.

2. A divided last comprising a fore part and a heel part having intermediate cooperating bearing surfaces, said surfaces including a concentric and an eccentric portion, a resilient connecting link connected at one end in the fore part and; at the other end inthe heel part to normallyv yieldingly press. said bearing surfaces together, -said surfaces having the eccentric engaging surfaces -disposed below the line of pressure exerted by.

said resilient link whereby to maintain the last partsln engagement so as to be yieldingly resistant to movement extended position.

i divided last comprising a forepart V heelppart having intermediate coopera ting bearing surfaces, sa d surfaces including concentric and eccentric po'rtions, a yield;

ing connecting member. connected at one-f d; s ashram; a d, ases? s.

the heel part to normally exert a yielding stress between said bearing surfaces, the eccentric portions of said bearing surfaces cooperating With the yielding connecting member and serving to maintain the last parts in yieldingly interlocked engagement when in either extended or .broken position.

4. A divided last comprising a forepart and a heel part having intermediate cooperating bearingsurfaces each of'said surfaces including a concentric and eccentric portion, a resilient connecting member having one end pivotally connected at the center of the concentric portion, the other end of the yielding member being connected in the second part of thelast so as to normally exert a yielding pressure between the cooperating bearing surfaces, a line passing through the points of connection at the ends of the resilient connecting memberpassing through the radial center of the concentric portion when the last is in either an extended or broken position, the eccentric portions of the bearing surfaces 011 each of the respective last parts, cooperating with the yielding connecting member to maintain the last parts in yieldingly interlocked engagement when in either extended or broken position.

In testimony whereof I aflix my signature.

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