US1513836A - Last - Google Patents

Description

Nov. 4 1924. 1 1,513,836 I H. W. LUCAS LAST Filed Sent. 11, 1922 lA/VENTUE- Patented Nov. 4, 1924.

UNITEQ STATE.

P all h 7? HARRY W. LUCAS, OF HOIiBROOK, MASSACHUSETTS, ASSIGNOR TO FITZ-EMPIRE DOUBLE IPIVOT LAST COMPANY, QF AUBURN, MAENE, A. GQREQBIATION OF MAINE.

LAST.

Application filed September 11, 1922.

To all whom it may concern:

Be it known that I, HARRY W. Lucas, a citizen of the United States, residing at Holbrook, in the county of Norfolk and State of Massachusetts, have invented certain Improvements in Lasts, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figures.

This invention is directed to lasts for making boots and shoes, and its principal object is to prevent certain types of destruction to which the heel parts of lasts are sub ject.

Many lasts are damaged or destroyed by heeling machine pressure, owing to lack of proper adjustment of the heeling machine to the particular last and shoe being treated. If the machine is set for too great a pres sure the wooden heel of the last is compressed to such a degree that it crushes and splits. If the pressure it taken by the metallic thimble, or mainly by it, the damage is even worse, since the pressure thus transmitted is localized more, and the thimble is frequently driven right into the wood. Even if the last has a leather or fibre top, which is sometimes used to avoid wear at the upper surface of the cone, since the toughness of fibre of these materials is superior to that of the Wood, it is found that a substantial oversetting of the heeling machine will drive these materials right into the wood, since they become actually harder than the wood itself at the instant of maximum compression in the heeling machine.

The present invention obviates this difliculty by providing a last having in the top of the cone of the last a piece of material which is essentially softer than the wood of the last even at the instant of maximum pressure of a substantially over-adjusted heeling machine, while at the same time firm enough. to transmit the pressure required in heelin'g.

One feature of the invention consists in a last the heel part of which has a piece of such material, for example, rubber, which answers the above requirements, projecting substantially above the end of the metallic thimble. Under the heeling pressure the rubber or other such material deforms and bulges out, but the thickness and $eria|l No. 587,417.

the extent of the projection of the rubber piece is so proportioned to its resiliency that even with a machine adjusted for a far too great pressure, the metal thimble will not come down to the jack, and consequently the hccling machine pressure is not transmitted to the wood through the unyielding metal. while the rubber itself does not become sufiiciently dense under the pressure to mar the wood,

These and other features of the invention comprising certain combinations and arrangements of parts will be understood from the following description of a preferred embodiment thereof selected for purposes of illustration and shown in the accompanying drawings in which,

Fig. l is a perspective of a last heel part in which the invention has been embodied.

Fig. 2 is a sectional elevation illustrating the behavior of the last under heeling machine pressure.

Fig. 3 is a sectional perspective illustrating another embodiment of the invention.

Fig. 4 is a sectional rear elevation showing the last of Fig. 3 under heeling machine pressure.

In Fig. 1 the heel part and thimble of the last are of ordinary construction except that there are shown at the top of the cone two plugs 10 of soft or medium rubber. These may be fastened in the last in any desired way, as by stems 12 projecting down into the wood, through which the rivets 14 extend. The plugs may be set in slots in the top of the last, as shown in Fig. 1, or may be simply mounted on the flat top. It will be noticed that the thimble 16 has its top substantially inch or so) beneath the upper surface of the rubber.

When the last is placed in a heeling machine between a jack 15 and a nailing die 17, and the pressure applied, the rubber is compressed to a substantial degree, and spreads out as shown in Fig. 2, since it is much softer than the wood, even at the-instant of maximum pressure and greatest compression, and cannot therefore be forced into the wood, and thus split or splinter it. Moreover, the thickness and the extent of projection of the illustrated rubber plugs 10 are so proportioned to their resiliency as to cause them to project substantially above the last thimble at the instant of greatest compression, even in a grossly overadjusted machine, so that the thimblet'op will not come into contact with the jack and transmit pressure directly from it into thewood; Asalready'pointed out, this would be liable to' split the heel.

The rubber top enables the vertical thickness of the last heel part to adjust itselft'o the distance set between the jack and the nailing die in the heeling machine. Just prior to the heel nail driving operation these approach each other by a distance of from to perhaps inch, depending on the setting of the machine. It the machine is set inch too close for an ordinary last, even through it have a leather or fibre top, or for alast with a flush or projecting thimble top, the last has an excellent chance of being split by the forcing of the top of the thimble into the wood. With the last of the present invention, however, considerably greater oversetting of the machine will beta-ken up by the rubber without damage to the last.

Figs. 3 and 4 illustrate a somewhat differenttype of rubber top. in this instance, the

rubber 18 extends over the whole cone with the thimble top 20 at a distance of or inch below its upper surface. Fig. 4 illustrates the application of, heeling machine pressure to this last. The rubber 18 will not need to project so far above the end of the thimble as does'either plug 10, since its area is much greater and it will not be compressed so much.

The material used for the protective top may be anything which is essentially softer than the wood at the instant of greatest compression in the heeling machine while rigid enough at that instant to transmit a pressure proper for heeling, and its total vertical dimensions and its projection above the thimble top will be soadjusted to its resiliency that at the instant of maximum heeling machine pressure it will still project substantially above the thimble top and prevent the transmission of pressure from the machine to the thimble. I have tried variousgrades of soft and medium rubber and stantially below the top of the rubber mem-.

her.

3. A wooden last heel part having its cone top provided with a piece of material which is essentially softer than the wood of the last at the instant of maximum compression of the material by the action of a heeling;

machine, and having its thimble top locate below the level assumed-- by the upper. sur- 7 face of the said material at the said'instant.

4. A wooden last heel part'having its cone top provided with a piece of material which is essentially softer than the wood at the instant of maximum compression of the material by the action of a heeling machine, whereby the vertical thickness of the heel part will adjust itself to the distance be tween the jack and nailing die of the heeling machine without undue stress on the wooden portion of the last heel part.

5. A last having a wooden heel part provided with a thimble and a rubber piece projecting above the woodand the to of the thimble, th thickness of the rubber piece'and the extent of its projection above the top of the thimble being so proportioned to its resiliency as to cause the rubberpiece' still to project substantially above the top of the thimblewhen the last is subjected to the maximum compression exerted by a heeling machine. i

In testimony whereof I have signed my name to this specification.

HARRY w. Lucas.

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