US1295890A - Last. - Google Patents

Description

E. B. G RUSH.

. 1 LAST. APPLICATION FILED lUNE5, 1916- RENEWED JAN. 12, I91B.

1,295 ;890., Patented Mar. 4,1919.

ELI/[ER B. GRUSH, F BEVERLY, MA$SACHUSETTS, ASSIGNOR, BY MES NE ASSIGNMENTS,

TO UNITED SHOE MACHINERY CORPORATION, OF TATERSON, NEW JERSEY, A COR- PORATION '0]? NEW JERSEY.

1,2e5,sec. 7

Application filed June 5, 1916, Serial No. 101,777.

To all whom it may concern:

less distortion of the shoe than has been possible heretofore.

In the manufacture of McKay shoes the I last is withdrawn between the lasting and sole attaching operations. Prior to the lasting operation the box toe materials are softened and after that operation the shoe with the last in it is set aside until the box hardens sufficiently to permit the pulling of the last, which is then removed and placed in an unlasted shoe. It is evident, therefore, that the time that the last remains in the lasted shoe has an intimate relation to the number of lasts required to keep the factory running. The diminution of this time by as small an amount as fifteen minutes is regarded as of the highest importance.

It is found that much of the dificulty experienced in rapidly removing lasts from shoes in general, and much of the distortion produced in the toes of McKay shoes by pulling the lasts too soon, is caused by the external air pressure,-the last fitting the shoe so tightly through the ball and instep that a partial vacuum is formed in the toe when the last is rapidly withdrawn. This partial vacuum creates an unbalanced external atmospheric pressure, which opposes the removal of the last and tends to collapse the box toe. Under the present practice in McKay work it is necessary to keep the last in the shoe until the box has stiffened sufficiently to support the unbalanced external atmospheric pressure due to the formation of this partial vacuum. It is an object of my invention to provide a last which shall ermit the equalization of the air pressure inside and outside the toe during the last pulling, thereby permitting the removal of LAST.

Specification of Letters Yatent.

Patented Mar. 4, i919.

Renewed January 12, 1918. Serial No. 211,674.

the last from a McKay shoe sooner than is allowable under present conditions, without injury to the box, and making easier the removal of lasts from shoes of all types.

A feature of my invention is a last having a channel extending from its toe rearwardly to communicate with the outside air, thus obviating the formation of a partial vacuum in the toe of the shoe during the last pulling operation.

Another feature of my invention is a last having an air pressure equalizing channel opening at its toe, the surface of the last being normal elsewhere, so that embossingaction ofthe last on the shoe is avoided.

Other features of'the invention, comprisingcertain arrangements and combinations of parts, will be described in the specificationand pointed out in the claims.

In the drawings which show the invention embodied in a block last,

Figure 1 is a side elevation, partly broken away, of a block last, and

Fig. 2 is a fragmentary plan view with the block removed.

The toe of the last has a'number of holes l bored in it extending from the front of the toe to the seat of the instep block 2. It is apparent that when the block 2 is removed the inside of the toe of the shoe will be in free communication with the outside air through the channels formed by these holes 1 and the space occupied by the block 2. There can therefore be no unbalanced air pressure to resist the pulling of the last or to collapse the box toe.

The use of my last will make easier the removal of lasts from shoes of all types, and will permit the removal of lasts from Mc- Kay shoes appreciably sooner after the lasting operation than is now possible, since a softer box will be able to stand the stresses of last pulling if the external atmospheric ressure is balanced from within. A Mcay factory can then be run with fewer lasits, and a corresponding economy will resu t.

The holes 1 are bored right into the body of the forepart of the last; in other words. their periphery is closed. It will be impossible, therefore, for the shoe to be marked in any way by the peculiar structure of the last, since the end of the toe will be protected by the box from any embossing action, and the remainder of the surface'of the last is perfectly normal.

It will be understood that my invention is not limited to block lasts. It issusce'ptible of embodiment in lasts of any form.

I have not claimed in this application the process of separating shoes and lasts which includes the step of admitting air to the toe of the shoe during the pulling of the last, since'I have claimed it in my application Serial No. 97,063, filed May 12, 1916.

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

l. A last constructed" and arranged to withstand the operations of machine shoe making and having a channel extending from the toe rearwardly to communicate with the atmosphere whereby the air pressure in the toe is equalized with that of the outside air.

2. A last constructed and arranged for performance of the lastingoperation and to contact the entire ball portion of ashoe with lasting pressure, and having an' air passage leading from the toe to a' portion'of the'last which is incontact with the outside air"dur Copies of this patent may be obtained for flve cents each, by add'restingthe ing the pulling. of the last, whereby the air pressure inside the toe" is'equalized with that of the outside air.

3. A last having a smooth and substantially "continuous lateral surface, for shaping the shoeduring thema king operations and having a channel constructed" and" arranged to transmit air into the toe of a shoe with sufiicient rapidity to prevent the formation of a partial vacuum in the toe during the last pulling op-e'r'ation; I

4. A last constructed and arranged to withstand the operations-01? machineshoe makingan'd having a channel of clo'sedperiphery extending from the toe "rearwardly to communicate with the outside air, whereby the air pressures inside and outside the shoe are equalized.

5. A last having achannel extending'from the toe to a portion of the last which is in contact with the outside air during thepulL ing of the last, the surface of the last being normal except where the channel the toe. Q

In testimony whereof I have name ,to this specification;

ELMER Bennett opens at signed my Commissioner '0! Patents;

Washington, D. 05

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