US1864977A - Hinged last - Google Patents

Description

June 28, 1932. H. E. CLARKE HINGED LAST Filed Jan. 24, 1930 be strong, simple y device may i0 show the ention relates to hinged lasts and and easily manufactured. be best understood by refl is a side view of my last in an exhinge or linkage means for holding the toe and heel portions together.

Fig. 2 is a side view of my last, similarly broken away, showing the last in a collapsed s a side view of the hollow pin which is embraced by one end of the connect- Fig. l is a vertical crosssection on line 4.-4:

Referring now more specifically to the e toe part of the last which part is provided with an integral boss or into a cyli Oppositely and heel par tion of a straig ndrical cavity in the heel part 4. disposed slots 5 and 6 in the toe ts of the last permit the inserht metallic link 7, the opposite ed in holes placed respeche toe and in the heel parts of the holes within which the pins 8 and 9 are mounted are so placed that when the last is in the extended position, as shown in Fig. l, a line connecting their axes will lie the axis of the cylindrical surthe distance between the axes ns when the last is in the extended s slightly less than the distance be when either end of the last is eleo that the said line passes through the slightly below face 3. Hence,

axis of the cylin Patented June 28, 1932 HINGED LAST Application filed January 24, 1930. Serial No. 423,205.

HAROLD EMERSON CLARKE, OF WEST' SOMERVILLE, MASSACHUSETTS a stretchable or resilient curved link in place has for its object to provide in a hinged last of my straight and non-stretchable link 7. having a common form of knuckle joint, an To compensate for the non-stretchability of d hinge 0r lmkage means Whlch Wlu my link 7, I have made the pin 9 hollow or y tubular and so thin that it may be slightly 5o distorted, or reduced in diameter, by the stress erence to the accompanying drawing in which of the link when the last is being broken Although I have shown the pin 9 as hollow tended Position and Partly broken may t0 andai@ pine assoiidatwiiib@ readiiyunderstood that these differences of structure may be reversed, or both pins may be hollow.

The pin 9 is preferably made slightly tapered at one end, as shown in Fig. 3, for convenience in inserting the pin within the link. I am aware that the use of a tubular pin has been previously suggested in the form of a pin provided with a slot so that the wall of the tubular pin is in effect a curved spring,

but such a pin is expensive to make and must be accurately positioned in the last and is apt to partially rotate accidentally in the course knuckle joint 2 of common construction pro- Qf the USG 0f the last, S0 that the Slot CO'IHGS vided with a cylindrical surface 3 which lits intO Such a position that the spring eect is lost. I have discovered that these very disadvantageous features of a slotted pin may be wholly and very advantageously eliminated by the use of a pin h ends of which are provided with round holes unbroken cylindrical wall through which p which are mount aving a continuous, provided that wall ass cylindrical pins 8 and 9 is made so thin as to be capable of slight dis- 75 tortion under the stress of the pressure of the link when the last is being broken. A thickness (if about one-thirtysecond of an inch in the steel stock employedin the tubular pin will give the desired result.

By the employment of my device the link 7 may be very easily and cheaply made without employing a hardened spring ste'el and since the hollow pin, unlike the curved spring link, affords a considerable initial resistance to distortion, my last holds the extended posidrcal Surface 3- To permit tion very strongly and will not sag in the this relative displacement of the axes of pins middle when in the inverted position in which r 8 and 9, it has been the practice to provide it iS Used.

Having thus fully described my invention. What I claim is:

A last having a toe part and a heel part arranged to turn about a common center, a pair of pins, one of which is transversely mounted in each of said parts, on a line ofi'- set from said common center, one of Which pins is tubular, and a straight non-resilient link connecting said pins, said pins being so supported in the last parts as to prevent longitudinal flexing of the pins away from their normal axes, and said tubular pin having normally a continuous unbroken cylindrical Wall so thin as to permit the distortion thereof when the last is moved to open and closed positions.

HAROLD EMERSON CLARKE.

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