US1546678A - Last - Google Patents

Description

Patented July 21, 1925.

UNITE STATES PATENT OFFICE.

CLINTON M. SEARL, 0E EQRTSMGU'II-I, OHIO, ASSIGNOR TO THE VULOAN LAST COM- PANY, O15 PORTSMOUTH, OHIO, A, GQ N 0 OHIO,

LAST. f 3 t i Original application filed April 21, 1924-, Serial No. 707,796. Divided and this application filed November 24, 1924, serial No. 751,756.

To all whomit may concern:

Be it known that I, CLINTON M. Simian, a citizen of the United States, residing at Portsmouth, in the county of Scioto and State 01" Ohio, have invented certain, new and useful Improvements in Lasts, of which the following is a specification, reference being had therein to the accompanying draw; ing.

My invention relates to an improvement in lasts and is particularly directed to lasts of the divided typethat is to say, to that type of last which is divided into two parts, a toe part and a heel part, movable relatively to each other to collapsed and extended positions. The present application is a division of my application filed April 21, 1924:, Serial No. 707,796. r v

It is desirable in lasts 01' this type that the last be capable of being easily collapsed so that it may be removed from a shoe with out injury to the lining of the shoe and without stretching the shoe out ofplace.

In lasting a shoe the last is held upside downthat is, with the sole side uppermost, and inasmuch as a great deal on? pressure is put on the toe of the last during the lasting operation, this tends to collapse the last, and consequently one of the objects of my-invention is the provision of a construction in which the last is capable of withstanding the stresses to which it is subjected during the lasting operation Without collapsing, but may be readily collapsed by the operator when desired.

In one form of last now in extensive use, the fore part and heel part are attached to each other by a link attached to the fore part and heel part by pins so located relatively that a line drawn through their centers will fall above the axison which the last parts move'when the last is collapsed and below this point or axis when thellast is extended.

In sucha construction, the greater the distance the pins are below the axis of the last when thelast is extended, or the greater the distance-they are above the axis of the last when the last is collapsed, the more resistance the last willoii'er to collapse orextension, but this distance is limited inasmuch as the pins must be located in the last body itself, and in the case of wooden lasts the pins must be kept at an appreciable distance from the bottom. sole fa e swine to the d ge of splitting the last when the same is in use or when being moved from extended position to collapsed position or vice versa.

In the present construction I have provided an arrangement for-attaching the two last parts to each other whereby an effect is obtained which is as 'efi'lcient as the lowering of the pins in the above-outlined construe tion to the danger point, the resistance to collapse or extension offered by my last being very materially increased, without, how ever, necessitating placing of any pins at a point where they are likely to cause the last to split, 7 r i It is one of the especial objects of my in-. vention to provide a last in which the last parts are held together under tension and not simply held in expanded or collapsed position under tension. 7

It is the further object of my invention to hold the last parts together by means employing a lever, with the parts constantly under tension.

It is a still further object of my invention to hold the parts of the last together under tension with the parts so arranged that the tension will assume its maximum when the parts are either in their fully expanded position or fully collapsed position.

It is an additional object of my invention to providethe holding together 01"- the parts under tension, and to associate therewith a lever, the parts being so arranged that the tension will achieve its maximum at the completely expanded or collapsed position of the last parts. It will be realized that the ten sion may be created by a variety of means which may be very compressible or expandable, and that the details of creating this condition are not essential.

It is a further object or" my invention to provide such mechanism to hold the parts of: the last together under tension that it will not be necessary to have resilient links or resilient anchor pins. Such means are eliminated and the same results are obtained.

It is a further object of my invention to provide the holding of such parts together under tension and the increasing of this tension at extreme positions together with means to lock the parts in extended position by such tension means to resist the pressure tending to collapse the last imposed on, the bottom of the toe member in constructing the shoe thereon until such tension means is over-come by the operator breaking the last.

In the accompanying drawings Figure 1 is a sectional view showing one embodiment of my invention.

Figure 2 is a similar View of another embodiment.

Referring to Figure 1, 1 designates the heel part and 2 the toe part of a last divided as customary by an arcuate cut, as indicated at 3. The center of the cut 3 is designated 4 and will be hereinafter referred to, for clarity of expression, as the axis of the last. 5 designates a connecting or tying link, one end of which is pivotally attached to one of the last parts (the heel part 1 in the present instance) by a pin 6, shown in section, this pin, when the last is in extended or fullline position, lying below the axis 1. The link 5 lies in the usual slots in the heel and toe parts and its other end extends into the toe part 2 where it is pivotally attached to one end of a second link 7 by a pin 8. The other end of the second link 7 is pivoted to the toe part of the last by a pin 9 which lies intermediate the pins (3 and 8-that is, intermediate the ends of the link 5. The pins 6 and 9 are relatively located so that a line drawn through the centers of these pins will fall below the axis 4 of the last when the last is extended and above this axis when the last is collapsed. The toe part 2 is provided with an orifice extending vertically of the last, in which is inserted a spring 11, this spring engaging the forward end of the link 5 at its point of pivotal connection to the second link 7. The spring 11 is held under compression between the forward end of the link 5 and a pin 12, the latter extcnding transversely of the last.

It will be seen, therefore, that the two last parts are pivotally attached to each other by a system of links attached to the two last parts at points below the axis of the last when the last is extended, this arrangement being such, however, that one point of attachment of this linkage to the last is intermediate the ends of one of the links.

With the parts in the position shown in Figure 1, it will be ap )arent that the spring 11 is exerting a pressure on the end of the levers or links 5 and 7, beyond the fulcrum or pin 9, in a direction to swing the forward or toe end of link 5 and link 7 downwardly, to hold the last parts to each other under tension. It will be apparent that when the last parts are being moved from the fullline position of the drawing toward collapsed position, the line of force. of the spring 11 will gradually approach the fulcrum 9in effect gradually shortening the lever arm represented by the distance between the lines a and'b', the line 6 representing the line of force of the spring 11 while the line a is parallel to the line I) and drawn through the center of the fulcrum 9. It follows, therefore, that the greatest distance between the lines a. and Z) is when the parts are in the full-line position of Figure 1, and hence the greatest tension under which the last parts are held to each other is when the last is in extended position. This is clearly a novel construction as compared with lasts of the prior art wherein the tension under which the last parts are held to each other is at its greatest when the last, parts are in such a position that a line drawn through the centers of the pins by which the usual connecting link is attached to the last parts passes through the axis of the last parts. In other words, I have provided a structure wherein the tension is at its greatest when it should be at its greatestto-wit, when the last parts are in full extended position, at which time the tension should be such as to prevent accidental collapse of the last. Having the greatest tension when the last parts are in dead center position, so to speak, is, of course, of no material advantage so far as preventing collapse of the last is concerned.

It will be seen also that when the last parts are in the dotted-line position of Figure 1, the lever arm represented by the distance between the lines a and Z) is longer than when the last parts are in dead center position, and hence the tension under which the last parts are held is at a maximum when the last is collapsed. This structure provides, therefor, maximum tension with the last parts in extended position and in collapsed position.

In Figure 2 a modification of my inven tion has been shown. The same principle, however, is involved in the construction of this last. The last of this figure comprises a heel part 13 and a toe part 1 divided along an arcuate cut 15, the center of which is 16 and constitutes what I have termed the axis of the last parts. Pivotallv attached to the heel part 18 by a pin 17 is a lever or link 18, this lever extending into the toe part of the last, where its forward end is pivotally attached at 19 to a second link 20, this link being pivotally attached to the toe part of the last by a pin 21 lo cated intermediate its ends. The end of the link 20 remote from the pin 19 is engaged by a spring 22, always under compression, between the end of the link and a pin 23.

It will be seen that in this embodiment of my invention the fulcrum 21 lies intermediate the ends of the link 18. It will be seen also that a line drawn through the centers of the pins 17 and 21, which pins constitute the pivotal connection of the links 18 and 20 to the last parts, falls below the axis 16 of the last when the last is extended,

and as a consequence the action of the spring 22 upon the end of the link 20 beyond the pin 19 is to tend to cause the pins 17 and 21 to approach each other to thereby hold the last parts in extended position under tension. l/Vhen the last is collapsed, the line passing through the centers of the pins 17 and 21 falls above the axis 16 and the last parts will be held in collapsed position under tension due to the action! of the spring 22.

In this embodiment ,of my invention it will be apparent that/the lever arm represented by the distance between the lines 6 and 7" will be at its r-reatest length when the last parts are in ixtended position or in collapsed position; and hence the force applied by the spring 22 will exert a maximum tension on the last parts when the last is extended and when the last is collapsed.

It will be a parent that I have provided a last structu e wherein the last parts are held in extended position and, in collapsed position under tension thereby providing a structure :which will successfully withstand accidental collapse or extension of the last parts when the same are in use in the manutactngi'e of shoes. It will be seen also that in invention I provide a structure in which the force exerted on the last parts to ,hold the last in extended and in collapsedf position is of some magnitude, my improved construction Ibeing such, however, that this increase in force is provided without weakening the last. In other words, more power is available for holding the last parts in adjusted position due to my improved structure than is possible in lasts as now manufactured.

It will be seen also that I have provided a last structure wherein the last parts are held in extended position and in collapsed position under greatest tension. In other words, the tension under which the last parts are held to each other when the last is extended or when the last is collapsed, as the case may be, is greater than the tension under which the last parts are held when in an intermediate position.

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

1. In a last of the divided type and comprising a toe part and a heel .part, a link pivoted to the heel part, a second link pivoted to the toe part, the ends of said links being pivoted. to each other, a line drawn through the points of attachment of said links with the toe part and heel part falla ing below the axis of turning of the last parts when the last is extended and above such axis when the last is collapsed, and means for applying a force directly to one of said links in a direction to tend to shorten the distance between the points of attachment of said links to the last parts when the last parts are in extended position and in collapsed position whereby the last will be held in extended position and in collapsed position under tension.

2. In a last of the divided type and comprising a toe part and a heel part, a link pivotally attached to the heel part and extending into the toe part, a second link pivotally attached to the to part intermediate its ends, one end of said secondmentioned link being pivotally attached to the first link, and means for applying power to the end of the second link remote from its point of attachment to the first link.

3. In a last of the divided type, the combination of a toe part and a heel part, a link pivotally attached to the heel part and extending into the toe part, a second link pivoted intermediate its ends to the toe part and having a pivotal connection to the first-mentioned link, and means for applying power to the second link at the end re mote from its point of attachment to the first link, the point of attachment of the second link to the toe part of the last being intermediate the ends of the first-mentioned link.

4-. In a last of the divided type and comprising a toe part and a heel part, a link pivotally attached to the heel part and extending into the toe part, a second link hav ing one end thereof pivotally attached to the first link, a pin intern'lediate the ends of said second link for pivotally attaching the second link to the toe part of the last, said pin lying between the ends of the firstmentioned link, and a spring always under compression for applying pressure to the end of the second link remote from its point of attachment to the first link, a line drawn through the points of attachment of the two links to the two last parts lying below the axis of turning of the last when the last is extended and above the axis when the last is collapsed and said spring through said links maintaining the last parts in extended position and in collapsed position under tension.

In testimony whereof, I aflix my signature.

OLIN TON M. SEARL.

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