US852909A - Watchmaker's tool. - Google Patents

Description

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PATENTED MAY 7, 1907.

E. NLSHELDON. WATGHMAKERS TOOL. APPLIOAQTION Pimp snrur 7.1906;

nm NORRIS PETERS ca, WISHINGTON. n. c,

ELMER N. SHELDON, OF MIDDLETOWN, CONNECTICUT.

WATCHIVIAKERS TOOL.

Specification of Letters Patent.

Patented May '7, 1907.

Application filed September 7, 1906- Serial No. 333.597.

I0 all whom it may concern- Be it known that I, ELMER N. SHELDON, a citizen of the United States, residing at Middletown, in the county of Middlesex and State of Connecticut, have invented a new and useful Watchmakers Tool, of which the following is a specification.

This invention relates to a tool which is designed for removing the hair spring collet from the balance staff of a watch.

The object of the invention is to provide a simple, cheap and convenient tool by means of which a watchmaker can quickly remove a collet from the staff without injuring any of the parts. This tool has a pair of curved fingers which are adapted to be closed beneath the collet and a threaded stem bearing .a screw which is ada ted to be turned so as to force the stafi longltudinally out of the collet which is retained by the fingers.

Figure 1 of the accompanying drawings shows a front view of a tool that embodies the invention. Fig. 2 shows an edge view of the same. And Fig. 3 shows a transverse section, on the plane indicated by m-:r.

The fingers 1 are preferably formed of a strip of suitably finished spring steel which has its ends curved and sharpened and that is bent at the center for the purpose of bringing the fingers into substantially parallel planes. These fingers are so bent that they tend to spring apart. Extending from one finger to the other is a threaded rod 2. This rod is preferably shouldered on the inside and provided with a nut 3 on the outside for securing it to one finger. On the inside of the other finger there preferably is a thumb nut 4 which may be adjusted as desired to limit the inward movement of the adjacent finger and outside of this finger is another thumb nut 5 which turns on the screw for the purpose of drawing the fingers together. It is preferred, although not essential, to have the outer thumb nut somewhat larger than the inner.

Extending centrally between the fingers and with one end secured to the joined ends of the fingers preferably by a nut 6 is a tubular stem 7. A portion of this stem is threaded and extending through the stem and having a thread which engages the thread in the stem is a pin 8 which is provided with a thumb piece 9. These parts are so arranged that when the pin is screwed in its pointed end travels centrally toward the opening between the ends of the curved fingers.

When a collet is to be removed the curved finger ends are moved toward each other beneath the collet, these ends being so curved and sharpened that they tend to force themselves between the collet and the balance while the-hair spring takes its position between the fingers above the collet. After the fingers are held in this manner by tightening the outer thumb nut the pin is screwed down against the end of the balance staff and continued screwing of the pin forces the balance staff out of the collet.

This tool is simple, cheap and can be conveniently used by any watchmaker for removing a collet without damaging the collet,

the hair spring or the balance staif and balance.

The invention claimed is '1. A watchmakers tool having a pair of fingers, a threaded pin movable centrally between the fingers toward and from their ends, and a screw and nut at one side of the pin for forcing the ends of the fingers together, substantially'as specified.

2. A watchmakers tool consisting of a pair of spring fingers formed from a single piece of spring metal and curved toward each other at their free ends, a screw and nut for forcing the free ends of the fingers toward each other, a stem secured to the joined ends of the fingers at one side of the plane of the screw, and a threaded pin extending through the stem and movable toward and from the opening between the free ends of the fingers, substantially as specified.

3. A watchmakers tool having a pair of spring fingers that are joined at one end and have their other ends curved toward each other, a screw and nut for forcing the free ends of the fingers toward each other, a nut for limiting the movement of the fingers, a central stem and a threaded pin movable in the central stem toward and from the open ing in the free ends of the spring fingers, substantially as specified.

ELMER N. SHELDON.

Witnesses:

HERBERT L. CLARK, G. B. KERNS.

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