US1536153A - Last - Google Patents

Description

c. M. SEARL May 5, 1925.

LAST

led April 21, 1924 Original F INVENTOR. m E "1 ATTORNEYS.

Patented May 5, 1925.

UNITED STATES p 1,536,153 PATENT, OFFICE.

cmn'ronivc. SEARL, or PORTSMOUTH, OHIO, ns-sronoa TO THE VULCAN LAST COIVL IANY, F PORTSMOUTH, OHIO, A CORPORATION OF OHIO.

LAST.

Original application filed Apr-i121, 1924, Serial No. 707,796. Divided and this application filed November 24, 1924. Serial No. 751,758.

To all whom it may concern:

Be itknown that I, CLINTON M. SEARL, acitizen of the United States, residing at Portsmouth, in the county of Scioto and State of Ohio, have invented certain new and useful Improvements in Lasts, of which the following is a specificatiomreference being had therein to the accompanying draw- My invention relates to an improvement in lasts, andis particularly directed to lasts of the divided type-that is to say, to that type of last which is divided into two parts, a toe part and a heel part, movable rela- 1 tively to each other to collapsed and extended positions. The present appllcatlon is a division of my application filed April 21, 1924, Serial No. 707,796.

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

In lasting a shoe the last is held upside downthat is, with the sole side upper- 1nostand inasmuch as a great deal of pressure is put on the toe of the last during the lasting operation, this tends tocollapse the last, and consequently one of the objects of my invent-ion is the provision of a construction in whichthe 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 partby pins so located relatively that a line drawn throughtheir centers will fall above the axis on which the last parts move when the last is collapsed and below this point or axis when the last is extended. 7

In such a construction, the greater the distance the pins are below the axis of the last i when the last isextended, or the greater the distance they are above the axis ofthe last when the last is collapsed, the more resistance the last will offer to collapse or extension, but this distance is limited inasmuch as the pins must be located in the'last body itself, and inthe case of wooden lasts the pins must be kept at an appreciable distance from the bottom orsole face owing to the danger of splitting the last when the same is in use or when being moved from extend- 7 ed 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 efiect is obtained which is as efficient as the lowering of the pins in the above-outlined construction to the danger point, the resistance to collapse or extension offered by my last being very materially increased, without, however, necessitating placing of any pins at a point where they are likely to cause the last to split.

It is one of the especial objects of my invention 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.

It is a 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 obj ectof my invention to holdthe parts of the last together under tensionwith the parts so arranged that the tension will assume its maximum when the parts areeither in their fully expanded or fully collapsed position.

It is an additional object of my'invention to provide the holding together of 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 It is a further object of my invention to i 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 I ing pivoted by 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 overcome by the operator breaking the last.

In the accompanying drawing I have shown a sectional view illustrating my invention.

In the drawing, 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 at and will be hereinafter referred to, for clarity of expression, as the axis of the last. The last parts are attached to each other by two links 5 and 6, the rear end of the link 5 bethe pin 7' to the heel part of the last, its forward end extending into the toe part of the last, where it is pivotally attached, as indicated at 8, to the link 6 intermediate the ends thereof. The one end of the link (5 is pivoted to the toe part of the last, as indicated at 9. It should be observed that the point of connection of the link 6 to the toe part of the last lies between the pins 7 and 8 and also that a line drawn through the centers of the pins 7 and 8, with the last parts in extended position, falls below the axis 5 of the last parts. It should be noted also that when the last is collapsed this line will fall above the axis 4. The link 6 ex- I tends beyond the pin 8 and its forward end is engaged by a spring 10 held under compression between the forward end of the link (3 and a pin 11 extending transversely of the last toe.

IVith the parts in extended position, as

shown in full lines, the spring 10 is exerting or toe end of link 5 and link 6 pressure on the forward end of the link 6 beyond the fulcrum S, in a direction to cause the pins 7 and 8 to tend to approach each other, and inasmuch as the centers of these pins lie below the axis 4 the last parts are held in extended position under tension. When the last is collapsed, the line passing through the centers of the pins 7 and 8 falls above the axis 4, and consequently the spring 10 at this time will be exerting a pressure on the link 6 to cause the pins 7 and 8 to tend to approach each other and thereby hold the last parts in collapsed position under tension.

From the drawing it will be apparent that the spring 10 is exerting a pressure on the levers or links 5 and (3, beyond the fulcrum or pin 9, in a direction to swing the forward 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 10 will gradually approach the fulcrum 9in effect gradually shortening the lever arm represented by the distance between the lines a and Z), the line I) representing the line of force of the spring 10 while the line a is parallel to the line b and drawn through the center of the fulcrum 9. It follows, therefore, that the greatest distance between the lines a and b is when the parts are in full-line position 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 vconnecting 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 greatest,to 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, 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, therefore, maximum tension with the last parts in extended position and in collapsed position.

It will be apparent that I have provided a last structure wherein the last parts are held in extended position and in collapsed position under tension, thereby prox iding a structure which will successfully withstand accidental collapse or extension of the last parts when the same are in use in the manufacture of shoes. It will be seen also that in my invention I provide a structure in which the force exerted on the last parts to hold the last in extended and in collapsed position is of some magnitude, my improved construction being 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 structurewherein 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 is i 1. In a last of the divided type and comprising a toe part and a heel part, a link pivoted tothe heel part and extending into the toe part, a second link pivoted to the toe part, said first link being pivotally attached to the second link intermediate the ends of the latter, and means for applying power to the end of the second link remote from its point of attachment to the toe part.

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 toe part, said first-mentioned link being pivotally attached to the second link intermediate the ends of the latter, and means for applying power to the second link at the end remote from the point of attachment of the second link to the toe part of the last and at a point in the last forward of the point of attachment of the first link to the second link.

In testimony whereof, I aflix my signature.

CLINTON M. SEAR-L.

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