US2404805A - Two-part collapsible last - Google Patents

Description

Jufiy 3, E4. I v. J. LEVAGGH, JR 9 9 TWO-PART COLLAPS IBLE LAS T Filed July 10, 1945 '/v Inventor Victor J Levaggi Jr By his Attorney MiMWA Patented July 30, 1946 TWO-PART COLLAPSIBLE LAST Victor J. Levaggi, Jr., Beverly, Mass., assignor to United Last Company, Portland, Maine, a corporation of Maine Application July 10, 1945, Serial No. 604,119

14 Claims. 1

The purpose of this invention is to provide improvements in two-part, two-pivot collapsible lasts in some respects similar to the type illustrated in my application for United States Letters Patent Serial No. 555,434, filed September 23, 1944, now issued as Patent No. 2,386,868, dated October 16, 1945. A last of. this type comprises a forepart and a heel part each provided with a pivot pin and the heel part also provided with a latching pin, a coupling link connecting the pivot pins, and means for automatically latching the forepart and the heel part in their last-forming relation.

One of the improvements provided by the present invention is embodied in counterpartal formations, one on the joint surface of the heel part and the other on that of the forepart, the one on the heel part being a truncate wedge-shaped ridge extending widthwise of the last, and the other being a wedge-shaped recess or valley to receive the ridge and to engage both of its converging shoulders when the parts are drawn one against the other by the connecting means. The interlocking of the ridge and the valley not only insures positive register of the forepart and the heel part in their last-forming relation, but it also relieves the connecting hardware from all torsional stresses encountered in certain pressure-applying machines through which some shoes pass during their process of manufacture.

Another improvement is embodied in a member having two flexible, resilient arms adapted to be flexed away from each other, one of the arms constituting a link for coupling the two pivot pins, and the other constituting a latching link for connecting the pivot pin in the iorepart and the latching pin in the heel part when the parts are in their last-forming relation.

The two-armed member is preferably made of a single piece of spring wire having a series of return bends one of which connects the coupling link and the latching link and provides an eye or loop adapted to extend around and engage the pivot pin in the forepart. This bend is also flexible and resilient, and these qualities, compounded with those of the links, provide an aggregate spring length so great as to permit using spring wire of a size that will withstand the buckling stresses to which a last may be subjected in shoe machines of one type or another.

Referring to the drawing,

Fig. l is a side elevation, partly in section, of a two-pivot collapsible last embodying the invention, broken lines indicating the position to which the iorepart may be moved to collapse the last;

Fig. 2 is a sectional view. indicated byline II--II in Fig. 1; and

Fig. 3 is a side elevation of the preferred form of resilient member for connecting the forepart and the heel part, broken lines indicating the manner in which its shape is altered by flexure incidental to latching andunlatching one of the links.

For the sake of economy a last of this type is first turned all in one piece and subsequently divided by oblique saw-cuts to provide a iorepart Ill and a heel part ll. One saw-cut 12 extends a short distance from the bottom of the last toward the instep, and another cut l3 extends a longer distance from the insteptoward the cut [2. These cuts do not quite meet but are offset in different oblique planes, and the wood between their terminal points isbroken to complete the dividing and provide the parts with cooperative sloping shoulders, I4, I41: adapted to register them in last-forming relation. The cut l3 may be made with a narrow band-saw and may follow a course that will produce sloping shoulders l5, I592, one on the heel part and the other in the forepart, but these shoulders will be rounded to permit one to ride easily over the other as the last is collapsed.

The shoulders i4 and I5 onthe heel part define a truncate wedge-shaped ridge 23 that extends widthwise, while the shoulders Ma: and I53: in the forepart define a wedge-shaped valley 24 in which the ridge may be nested. Since no wood isremoved in producing the shoulders M and both shoulders of the ridge may be seated against the shoulders of the valley, and thereby register the forepart and the heel part in true relation despite torsional stresses tending to twist them out of register. The connecting member about to be described is not subjected to torsional stresses, since the ridge and valley shoulders sustain those stresses so long as the connecting member maintains the shoulders in contact with each other. This member is preferably made of a single piece of spring steel wire of elliptical section having an arcuate return bend 25 at one end, an arcuate return bend 26 at the other end, an eye portion formed by an arcuate return bend 21, and a latching shoulder 28 formed by an abrupt bend between the eye portion 21 and the terminal bend 26.

The forepart is bored widthwise to provide a hole for a pivot pin I6, and the heel part islikewise bored to provide two holes, one for a pivot pin l1 and the other for a latching pin [8. The pins l6 and I8 are so located that a line intersecting them will lie between the shoulders l4 and It. The pin l6 bridges a heightwise kerf IS in the forepart and the pins l7 and i8 bridge a registering kerf 28 in the heel part. The kerf 20 extends to a last-pin socket 21 in the heel part for a purpose hereinafter explained but also set forth in the application above mentioned. A slot 22 in the front Wall of the socket affords access to the kerf 20 from the interior of the socket.

The connecting member occupies the kerfs I9 and 20 the bend 25 thereof extends around and engages the pivot pin l1; and the bend 2 extends around and engages the pivot pin Hi. The

arm portion 29 connecting the bends 25 and 2! possesses some flexibility and resilience, and the arm portion 3!] connecting the eye 2] and. the. shoulder 28 also possesses some flexibility and resilience, while the eye 21, itself, possesses the same qualities in some degree. These qualities enable the arm portion 38 to be flexed away from the arm portion 29 in the manner indicated by broken lines in Fig. 3. a

The arm 29v and the bends 25 and 2'! constitute a coupling link, while the arm 30, the bend 2 and the shoulder 28 constitute a spring-loaded latching link. The latching shoulder faces the eye portion 2'! and is adapted to hook the latching pin l8 (Fig. 1)- when the parts It and H. are in last-forming relation. Moreover, the arm 30 has a curvature of long radius which normally draws the shoulder 28 toward the eye 2-! but permits it to be sprung. away from the latter in consequence of reducing the curvature. The effective length of the arm 30 is thus rendered normally contractile but. capable of being extended under stress. The results afforded by this feature are hereinafter explained.

The arms 29 and 30, when relaxed, extend in the same general direction from the eye. portion 21, and the pins I1 and i8 are-s spacecLone from the other, that it is necessary tov spring the arms slightly away from each other to assemble the last. The effective length of the coupling link is preferably a little greater than the minimum re quired by the pivot pins 16 and i! when the parts are in last-forming relation, but. the range of lost motion thus. provided is less than the elastic range of the latching link. At the same time against the bottom of the last between its points of support might be so greatas to open a crack between the cone portions of the iorepart and heel part. Under these conditions the curvature of the arm 39 will enable the latching link to yield to the demands of the buckling stress without overloading or unbending the latching shoulder, and the distance between the pivot pins l6 and I! may be increased only to an extent limited by the effective length of the coupling link. The latter will then assist the latchng link in sustaining the buckling stress, andthereby save the latching shoulder; from being; unbent. When the buckling stress is taken ff. or nearly so, th

4 resilience of the arm 30 again draws the forepart and heel part one against the other.

To collapse the last it is necessary, first, to flex the latching link to the positionindicated by broken lines in Fig. 3, and thereby release the pin Hi from the shoulder 28. The forepart may then be shifted to the position represented by broken lines in Fig. 1. When it, has been shifted far enough to place the pin IS on the step 3| between the shoulder 28 and the bend 26 reflex action of the connecting member against the pin [8 will complete the shifting if the last be unshod, or, at least, tend to do so if the last is confined in, a shoe. In either event, the step 3-! will react against the latching pin and slide thereon.

The sl t 22 in the socket 2| permits an implement such as a screw-driver to be inserted through the socket and into engagement with the outcurved surface of the bend 26. Such an implement may be used to pry the latching link away from the coupling link and thereby trip the latch, and in doing so it will reduce the curvature of the arm 3i! slightly and thereby increase the length of the latching linkfin a corresponding. de-: gree to disengage the shoulder 28. from the pin l8. Conversely, when the, parts l0 and H are shifted from sollapsed relation to last-forming relation the pin. it and the step. 3.! will cooperate to. flex the latching link away from the coupling link. Here, also, the flexing stress will reduce. the cure vature of the, arm 311 enough to. permit. the latch. ing shoulder 28 to snap over and catch, the pin is, whe eupon. t e arm 30 will resume. as. muehor its ormal curvature as. the bins. l6 and [twill per: m t, and th by draw t e parts I Q and. U a ainst: eac o her.-

Hav ng d s bedmy inv ntio whatl c aim as w and e ir o se ure y Lett rs Patentci h United States is: i

1. Atwo-part last comprising a forepart and a ee art ha g ng.- ob ique j nt su a e the abutting portion of the heel part includin a truncate wedge-shaped ridge having sloping shoulders and extending widthwise, the abutting portion of the forepart including a wedge-shaped valley extending widthwise to receive said ridge and thereby register the parts, in last-forming relation, each of said part also having a kerf extending heightwise and intersecting its wedgeshaped formation, a pivot pin bridging the kerf in one ofsaid parts, a latching bridging th kerf in thefother one of said parts, and a spring-loaded link arranged in said kerfs, the link being pivotally mounted on said pivot pin and having] a latching shoulder arranged to hQQkfsaid latching pin when said ridge is nested in said valley.

2. A twoepart last comprising a forepart and a heel part having abutting oblique joint surfaces, the abutting portion of the. heel part including a truncate wedge-shaped ridge having sloping shoulders and extending widthwise, the abutting portion of the forepart including a wedge-shaped valley extending widthwise to receive saidridge and thereby register the parts in last-forming relation, each of said parts also having a kerf extending heightwise and inter ecting its wedgeshaped formation, a pivot pin bridging thekerf in the forepart, a pivot, pin bridging th erf in the heel part, a coupling link, connecting said pivot pins to guide said ridgeinto. and out. of said valley, and latching means located in said kerfs and arranged to lock the forepart and the heel part one against the other when said ridge is. nestedin saidvallex. 3

A'two-part last comprising a forepart, and a heel part having abutting oblique joint surfaces, the abutting portion of the heel part including a" truncate wedge-shaped ridge having sloping shoulders and extending widthwise, the abutting portion of the forepart including a wedge-shaped valley extending widthwise to receive said ridge and thereby register the parts in last-forming relation, each of said parts also having a kerf extending heightwise and intersecting its wedgeshaped formation, a pivot pin bridging the kerf in one of said parts, a latching pin bridging the kerf in the other one of said parts, and a springloaded link arranged in said kerfs, the link being pivotally mounted on said pivot pin and having a latching shoulder arranged to hook said latching pin when said ridge is nested in said valley, and said pins beingso located that a line intersecting them when the ridge is nested in the valley will also intersect the ridge.

4. A two-part last comprising a forepart and a heel part having abutting oblique joint surfaces, the abutting portion of the heel part includin a truncate wedge-shaped ridge having sloping shoulders and extending widthwise, the abutting portion of the forepart including a wedge-shaped valle extending widthwise to receive said ridge and thereby register the parts in last-forming relation, each of said parts also having a kerf extending heightwise and intersecting its wedgeshaped formation, a pivot pin bridging the kerf in one of said parts, a latching pin bridging the kerf in the other one of said parts, and a springloaded link arranged in said kerfs, the link being pivotally mounted on said pivot pin and having a latching shoulder arranged to hook said latching pin when said ridge is nested in said valley, said pins being so located that a line intersecting them 7 when the ridge is nested in the valley will lie between the shoulders of the ridge, and said link being resilient and contractile to draw said pins toward each other.

5. A two-part last comprising a forepart and a heel part having abutting oblique joint surfaces, the abutting portion of the heel part including a truncate wedge-shaped ridge having sloping shoulders and extending widthwise, the abutting portion of the forepart including a Wedge-shaped valley extending widthwise to receive said ridge and thereby register the parts in last-forming relation, each of said parts also having a kerf extending heightwise and intersecting its wedge-shaped formation, a pivot pin bridging the kerf in the forepart, a pivot pin and a latching pin located one above the other and each bridging the kerf in the heel part, a coupling link connecting said pivot pins to guide said ridge into and out of said valley, and a latching member carried by said pin in the forepart and having a shoulder arranged to hook said latching pin when said ridge i nested in said valley.

6. A two-part, two-pivot collapsible last comprising a forepart and a heel part having abutting joint surfaces including cooperative shoulders arranged to register the parts heightwise in last-forming relation, each of said parts also having a kerf extending heightwise in its joint portion, a pivot pin bridging the kerf in the forepart, a pivot pin and a latching pin each bridging the kerf in the heel part, and a spring having two resilient arms and an eye portion connecting them, said spring being located in said kerfs and said eye portion being located in the forepart, one of said arms and said eye portion connecting said pivot pins, and the other arm having a latching shoulder facing said eye por' tion and arranged to hook aid latching pin when the parts are in last-forming relation.

7. A two-part,'two-pivot collapsible last comprising a forepart and a heel part having abutting joint surfaces including cooperative shoulders arranged to register the parts heightwise in last forming relation, each of said part also having a kerf extending heightwise in its joint portion, a pivot pin bridging the kerf in the forepart, a pivot pin and a latching pin each bridging the kerf in the heel part, and a spring having two resilient arms and an eye portion connecting them, said spring being located in said kerfs and said eye portion being located in the forepart, one of said arms and said eye portion connecting said pivot pins, and the other arm having a latching shoulder facing said eye portion and arranged to hook said latching pin when the parts are in last-forming relation, said other arm being flexible and normally curved between the latching shoulder and said eye portion, and the effective length thereof being thereby rendered contractile and extensible.

8. A two-part, two-pivot collapsible last comprising a forepart and a heel part having abutting joint surfaces including cooperative shoulders arranged to register the parts heightwise in last-forming relation, each of said part also having a kerf extendingheightwise in its joint poi tion, a pivot pin bridging the kerf in the forepart, a pivot pin and a latching pin each bridging the kerf in the heel part, and a spring having two resilient arms and an eye portion connecting them, said spring being located in said kerfs and said eye portion being located in the forepart, one of said arms and said eye portion connecting said pivot pins, and the other arm having a latching shoulder facing said eye portion and arranged to hook said latching pin when the parts are in last-forming relation, said other arm having a free end beyond and extending from said latching shoulder to engage said latching pin when the last is collapsed and by such engagement to flex that arm as the parts are relatively moved toward their last-forming relation.

9. A two-part, two-pivot collapsible la'st comprising a forepart and a heel part having abutting joint surfaces including cooperative shoulders arranged to register the parts heightwise in last-forming relation, each of said part also having a kerf extending heightwise in its joint portion, a pivot pin bridging the kerf in the forepart, a pivot pin and a latching pin each bridging the kerf in the heel part, and a spring consisting of a single piece of spring wire forming two arms and an arcuate return bend connecting them, said spring being locatedin said kerfs and said return bend extending around and engaging said pin in the forepart, one of said arms having a return bend extending around said pivot pin in the heel part, and the other one of said arms having a step and an intermediate bend forming a latching shoulder arranged to catch said latching pin when the forepart and the heel part are in last-forming relation, said step being arranged to exert pressure against said latching pin when the last is collapsed.

0. A connecting member having an arm and two pivoting portions at opposite ends thereof for coupling two pivot pins in the forepart and heel part, respectively, of a collapsible last, said member also having a flexible and resilient arm provided with a latching shoulder, said arms be- 7 ing connected by one of said pivoting portions. 11. A member for connecting; the forepart and the heel part of a two-pivot collapsible last, said member consisting of a single piece of spring wire forming two flexible arms andan arcuate return bend connecting them and adapted to extend around and engage a pivot pin in one of the parts, the free end of one of said arms having a bend adapted to extend around and engage a pivot pin in the other part, and the other one of said arms having a, bend forming a latching shoulder adapted to cooperate with a latching pin in said other part, said arms being relatively movable toward and from each other to effect latching and unlatching.

' 12. A member for connecting. the forepart and the heel part of a two-pivot collapsible last, said member consisting of a single piece of spring wire forming two flexible resilient link portions and an arcuate return bend connecting them in series and adapted to extend around and engage a pivot pin in one of the parts, said link portions extending in the same general direction from opposite ends of said bend, the free end of one of said link portions having a return. bend adapted to extend around and engage a pivot pin in the other part, and the other link portion having a bend forming a latching shoulder facing said connecting bend, said link portions being relatively movable toward and from each other to efiect latching and unlatching.

and an arcuate return bend connecting them in series and adapted to extend around and engage a pivot pin in one of the parts, said link portions extending in the same general direction from opposite ends of said bend, each of saidlink portions having a return bend at its free end and one of them having an intermediate bend forming a latching shoulder facing said connecting bend.

14. A member for connecting the forepart and the heel part of a two-pivot collapsible last said member consisting of a single piece of spring wire forming two flexible resilient link portions and an arcuate return bend connecting them in series and adapted to extend around and engage a pivot pin in one of the parts, said link portions extending in the same general direction from opposite ends of said bend, one of said link portions being considerably longer than the other and having a return bend at its free end and an intermediate bend forming a latching shoulder facing said connecting bend, and the shorter one, of said link portions having a return bend at its free end adapted to extend around and engage a pivot pin in the other one of the parts.

VICTOR. J. LEVAGGI, JR.

Images