US2260568A - Last - Google Patents

Description

Patented Oct. 28, 1941 UNITED STATES PATENT ,OFFICE LAST Harold Goodman, Peabody, and Earl J. McGown,

, Lynn, Mass. Application March 18, 1940, Serial No. 324,464

1 Claim. I ((112-136) This invention relates to hinged lasts and has for its object the production of a single spring element serving as a connector between the two parts of the last, which element will hold said parts rigidly together when either in extended or shortened position while permitting slight relative movement of said parts toward and from each other at intermediate points.

This object is attained by the mechanism illustrated in the accompanying drawing. I

For the purpose of illustrating the invention, one preferred form thereof is illustrated in the drawing, this form having been found to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which the invention consists can be variously arranged and organized, and the invention is not limited to the precise arrangement and organization of these instrumentalities as herein shown and described except as required by the scope of the appended claim.

Of the drawing Figure 1 represents a longitudinal vertical section of a two part last, the two parts of which are connected by a single spring element embodying the principles of the present invention, the last being shown extended.

Figure 2 represents a similar section showing the last shortened.

Figure 3 represents a horizontal section of the portion of the last on line 3, 3 on Fig. 1.

Figure 4 represents a section of the fore part of the last on line 4, 4 on Fig. 1.

Figure 5 represents a section of the heel part on line 5, 5 on Fig. 1, and

Figure 6 represents an elevation of the spring element removed from the last.

Similar characters indicate like parts throughout the several figures of the drawing.

In the drawing, I0 is the fore part of a divided last having formed in its rear face a curved depression I I extending transversely thereof.

The heel part l2 has formed on its front face a semi-cyclindrical projection I3 adapted to be positioned in the depression I I and contact with the wall thereof.

The depression II is semi-cylindrical and has a radius slightly exceeding that of the semicylindrical projection I3.

Owing to the differences in the radii of the projection I3 and depression I I, the outer surface of the projection I3 will not contact with the surface of the depression II at the top and bottom thereof.

The fore part I0 is provided with a vertical slot or recess I4 in its rear end which is alined-with a similar slot or recess I5 formed'inthe front end of the heel part I2.

The side walls of the slots or recesses I4 and I5 are perfectly flat and parallel to each other.

Extending transversely' of the slot or recess I4 is a cylindrical pin I6 embedded in the fore part I0 and in the heel part I2 is another cylindrical pin I1 extending transversely of the slot or recess I5.

Mounted on these pins I6 and IT and disposed within the slots or recesses I4 and I5 is a single spring element I8, as shown in Fig. 6 of the drawing. V I

This spring element I8 is bent upwardly in the center thereof as indicated at I9 in Fig. 6 of the drawing, and the opposite ends 20 thereof are bent upwardly parallel to the surfaces H of said spring element.

Between the surfaces 2| and the upwardly bent ends 20, the pins 16 and I! are adapted to be disposed.

This spring element I8 is of the same thickness as the width of the recesses I4 and I5, and is provided on its opposite faces with flat surfaces 22 which bear against the side walls of the recesses I4 and I5 when the last is being shortened or lengthened.

These fiat surfaces 22 contacting with the walls of the recesses I4 and I5 retain the two parts I0 and I2 of the last in proper alinement at all times.

The spring element I8 is highly tempered and notwithstanding the size of said spring element, it is sufiiciently resilient to permit the movement of one last part I0 relative to the other last part l2.

When the last is straightened as shown in Fig. 1 of the drawing a portion of theperiphery of the semi-cylindrical projection I3 will be held in rigid contact with the central portion of the depressions I I and the center line between the pins I6 and I1 will be considerably below the axis 23 of the projection I3.

When shortening the last by moving the fore part I0 about the axis 23 and, relatively to the heel part I2, said axis 23 must move toward the bottom of the last and pass across the center line between the centers of the pins IB and I1. Owing to this center line between the pins I5 and 11 being well below the axis 23 of the projection I3 when the last is shortened as shown in Fig. 2, the fore part I2 can be moved about said axis 23 in order to lengthen the last only by applying great pressure thereto.

position as indicated in Fig. 1.

As a consequence, the two parts Ill and I2 of the last are connected by a single element in such a manneruthat the last is very rigid when in either shortened or extended position. ,It will be noted that upon breaking the last when in its extended position the last will immediately commence to shorten.

The projection 13 of the heel part l2 resting in the depression I I of the fore part forms a knuckle joint.- I I 'Itis quite obviousthat when a shoe is on a last and is being operated upon in the manufacture thereof, it is very. essential that the last should have a great degree of rigidity and this result is produced very effectually by the .methcd herein shown and described. 2

It isbelieved to be novel to connect thev two parts I!) and. I2 of the last by means of a single spring'element dispensing with other instrumentalities which'have been found necessary in other constructionsof connecting means between the two parts of the last.

Owing to the increased size of the spring element l8 over similar spring elements heretofore in :use, it has been found an advantage to have point and there has been liability to breakage,

necessitating the replacing of the broken spring elements with new spring elements.

The spring element I8 is hardened at 1500 F., then quenched in oil, and then tempered at 850 F. for two hours.

By means of the construction herein shown and described a very strong two part last is provided Which is capable of meeting hard usage and at the same time owing to the dispensing of many other instrumentalities heretofore in use the last is made at a minimum expense.

It is believed that the operation and many advantages of the invention will be understood Without further description.

Having thus described our invention, we claim:

A last having two parts arranged for movement relatively to each otherabout a knuckle joint and each part provided with a relatively wide vertical recess with fiat parallel side walls; a pin extending transversely of each recess and spaced from the axis of said knuckle joint; and a sole connector within and contacting with the side walls

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