US305927A

US305927A - Geoege m

Info

Publication number: US305927A
Authority: US
Publication date: 1884-09-30
Anticipated expiration: 1901-09-30

Description

Remodel) G. M. HOPKINS.

TELEPHONE 330313133. No. 305,927. Patented Sept. 30, 18.84.

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UNITED STATES PATENT GEORGE M. HOPKINS, OF BROOKLYN, NEW YORK.

TELEPHONE-RECEIVER.

IEEGIPICATION forming part of Letters Patent No. 305,927, dated September 30, 1884.

Application filed February 29. 1884.

(No model.)

To all whom it may concern:

Be it known that I, GEORGE M. HOPKINS, a citizen of the United States, residing in Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in ReccivingTelephones; and I do hereby declare that the following is afull, clear, and exact description thereof, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to magneto receivingtelephones; audit consists in an arrangement of curved permanent magnets secured to the diaphragm at one end and attached at the other end to a central pole-piece common to all of the magnets, and carrying a helix for receiving the telephonic current.

It further consists in connecting an auxiliary diaphragm with the pole, for the purpose of utilizing the vibrations of'the said polepiece and thecurved magnets.

Figure 1 is asectioual View of my improved telephone-receiver, and Fig' 2 is a section taken on line a: w in Fig. 1.

The diaphragm A is clamped on the cell 13 by the apertured cap 0. Three or more perinanent bar-magnets, D, bent at right angles and then curved spirally, are secured by their straight ends to the diaphragm A, near its pcriphery, and their curved ends converge toward the center of the cell B, and are clamped by the washer a and screw b to the enlarged inner end of the pole-piece E, supporting the said pole-piece axially to the cell, and with the smaller end near but not touching the cen ter of the diaphragm. Upon the pole-piece E is mounted a helix, F, whose terminals-are connected with the wires of the telephonecircuit.

Upon the back of the cell B, opposite the diaphragm A, and parallel with it, is secured an auxiliary diaphragm, G, by means of the cap H, and the center of the said diaphragm is secured to the washer c and pole-piece E ends of the bar-magnets to the pole-piece. The diaphragm G partakes, of the vibrations of the magnets and pole-piece, and it need not con sist of magnetic material. The cap H has a chamber, 0, which communicates with the space d between the diaphragm A and cap 0, through the passages 6, formed in the caps and in the body of the cell. lVhen changesoccur in the current traversing the helix F,

the changes effected thereby in the magnetism 5 of the core E cause the alternate attraction and release of the diaphragm A, and a reciprocal attraction of the core, and a corresponding, although diminished, motion of the parts attached to the core, including the diaphragm G. The sounds produced by the diaphragm G areoommunicated to the car through the chamber 0, passages c, and space (I, and serve to re-enforce the sound proceeding from the diaphragm A.

Having thus described my invention, what- I claim as new, and desire to secure by Letters Patent, is-

The combination, with a series of converg ing bar-magnets clamped to a vibratory polepicce, of an auxiliary diaphragm located in the back of the receiver-case, and connected with the vibratory core, the said auxiliary diaphragm acting in conjunction with the usual diaphragm to re-enforce the sound, as specified.

GEORGE M. HOPKINS. Witnesses:

Oniis. L. Cons, HERMAN G. HAGES.

by the same screw, I), that binds the curved 5