US2027952A - Magnetic compass - Google Patents

Description

Patented an. 14,1936

PATENT. OFFICE I MAGNETIC COMPASS Erich Bandoly, Rochester N. 1., assignor to Tay- Instr-amen lor a corporation of New York es, Itooliester, N. Y,

Application June 8,1984, Serial N... 229,688 3 Claims- (01. as-zze) This invention relates to a magnetic compa s. The purpose of the invention is to provide a magnetic compass which is reliable in operation, simple in construction and inexpensive to manus facture. The various features of the invention will appear from the detailed description and claims when taken with the drawing in which Fig. 1 is a front view of a magnetic compass according to the present invention with a portion of the crystal and its'support broken away; and Fig. 2 is a cross-sectional view taken substantially on the line 2-2 of Fig. 1.

The magnetic compass of this invention includes a case I, having an upstanding rim 6 within which the parts of the compass are enclosed.

This case which is preferably molded from a suitable light material such as a phenol condensation product, is provided with an internal annular shoulder I to engage frictionally the edge of a 29 metallic disc I having imprinted thereon compass graduations. This disc preferably makes a press lit with the side of the shoulder I and at its center there is mounted in any suitable manner a central post 9 terminating in a point bearing.

This post serves as a pivot for the magnetic needle II which carries at an intermediate part thereof, a jewel cap ll including a jewel hearing if to,

receive the point bearing of the post. The tree ends of the needle I. terminate in the plane of an annular graduated dial member I! having an annular shoulder ll adapted to make a press fit with the inner surface of the upstanding rim 8 of the case. The annular shoulder M of the dial 35 member is provided with an oif-set lug ll engagthe end of the upstanding rim 6 to limit the inward movement of the dial member, while the ireeedge l'l ofthelug servesasabezelto grip a suitable transparent crystal I, of any transparent material, whichcloses the case. This edge I! may be spun over the beveled edge of the crystal. Thus the dial member It also serves as a support for the crystal.

I claim:

1. In a device of the character. described, a case having an upstanding rim, a dial member trictionally mounted in said case in spaced parallel relation to the bottom thereof, an index mounted for'rotation in said case and having its ends terminating substantially in the principal plane of the dial member, a crystal closing said case, and a bezel integral with said dial member for holding said crystal.

.2. In a device of the character described. a case provided with an upstanding rim, an annular dial member having a shoulder frictionally engaging said upstanding rim, said dial member extending in a plane parallel to the bottom or said case, an index mounted in said case for rotation with respect to said dial. said index having its ends in substantially the principal plane of said dial, an annular lug on saidshoulder engaging the edge of said rim, a crystal closing said case, and a bezel integral with said lug for holding said crystal.

3. In a device of the character described, a case provided with an upstanding rim and also provided with an annular shoulder adjacent its bottom, a disc iriction'ally enga in said annular shoulder. a supporting shaft projecting from the center .of said disc, an index mounted on said shaft, an annular dial member having its principal plane in substantially the plane oi the ends of said index, said dial being shaped to form an integral shoulder frictionally engaging the inner wall of said rim, then turned outwardly to form a lug integral with said shoulder engaging the edge of said rim, and a crystal closing said case, said lug being turned inwardly to form a bezel for holding said crystal.

' I ERICK BANDOLY.

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