US291684A

US291684A - Telephone

Info

Publication number: US291684A
Authority: US
Publication date: 1884-01-08
Anticipated expiration: 1901-01-08

Description

Parent @rrrea JOSEPH GHEEVER, OF SOMERVILLE, MASSACHUSETTS.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 291,684, dated January 8,. 1884. Application filed February 15, 1883. (No model.)

1'0 all whom, it may concern.

. Be it known that I, J OSEPH H. CHEEVER, of Somerville, in the county of Middlesex and State of Massachusetts, have invented certain 5 Improvements in Telephones, of which the following is a specification. M My invention relates to magneto-telephones, and has for its object the production of an iny strument that will both transmit and receive 1o speech with great distinctness of articulation,

and great volume.

The principal feature of this invention is the y 1 employment of two 'diaphragms, preferably of p iron, these diaphragms forming one a com- :mon north pole-piece and the other a common south pole-piece for a number of magnets arranged radially around and connected with the diaphragms. Referring to the drawings accompanying this specification, Figure 1 is a rear view of (the diaphragms, showing the magnets radiating therefrom. Fig. 2 is a sectional view, showing an electro-magnet attached to the diaphragms. instrument.

A suitable wooden frame, F, has a mouthpiece, M, fitted therein. On the rear of the upright portion of the frame F is a recess, g and covering this and fastened by its edges is 3 o adiaphragm, D. This diaphragm is fastened to the frame with screws B, which, passing through the north ends of magnets N and through the diaphragm, serve to hold the magnets in contact with the diaphragm, and both to the wooden frame M. The magnets N S are curved or made U shape, and have their south ends, S, connected radially with a second diaphragm, I. Between these two diaphragms, and of a thickness nearly equaling thespace between the diaphragms, is a coil, 0, of insulated copper or iron wire. This coil is made of large diameter relative to its .phragms. The terminals of this coil are to be fconnected with the line-circuit, in the usual manner.

In Fig. lfthere are eight permanent magnets, shown as connected radially around and I with the edge of the diaphragms, but the numg her may be increased to as many as can be se-. H cared to the diaphragms or there is room for.

Fig. 3 is a section of the entire thickness, and is nearly as wide as the dia-.

in the vicinity of the coil, which may be in creased to great strength by the use of large diaphragms and strong electro-magnets.

In speaking-near to the mouthpiece both diaphragms are set in vibration, although the rear one in a lesser degree. Its inductive effects are added to that of the front diaphragm,

D, because, being of an opposite polarity to the diaphragm D and being on the opposite of the coil, its inductive effect is similar in character to that of the diaphragm D; hence there is no neutralization, and the combined effects of both diaphragms are utilized.

The coil 0 is made of fine wire preferably, as there is a large number of convolutions of wire exposed to the inductive action of the diaphragms by so making.

This telephone acts equally well as a re ceiver and transmitter, and when two are connected together in circuit, speech uttered in one will set its diaphragms in vibration, causing alternating currents of electricity of an undulatory character, to be induced in the coil thereof, which currents, passingover the connecting-wires to the second tclephone,will cause the diaphragms in the latter to vibrate synchronously with'the former, thus repro ducing the speech uttered.

I am aware that telephones have been made with diaphragms charged so as to be of a north polarity on one face and a south p0 larity on the other; also,tl1at a diaphragm has been made having magnets the north ends of which are united, so as to form a pole-piece for a coil of wire, and the south ends placed near to or in contact with the diaphragm.

I do not claim, broadly, the charged diaphragm.

I claim- In a telephone, the combination, with two diaphrams one of which constitutes a common north pole-piece and the other a common in the presence of two subscribing witnesses, south pole-piece of a number of electro or this 13th day of February, 1883. permanent ma nets of a coil of insulated wire placed betweeil said diaphragms or pole- I JOSEPH OHEEVER' 5 pieces, and to be included in the line-circuit, substantially as and for the purpose described. In testimony whereof I have signed my name,

Witnesses:

GEO. XVILLIs PIERCE, D. E. RICHARDS.