US276723A - George edwin shaw - Google Patents

Description

- (No Model.)

G. E. SHAW.

TELEPHONE RECEIVER.

Patented May 1 UNITED STATES PATENT OFrIcn GEORGE EDWIN SHAW, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE SHAW TELEPHONIG COMPANY OF AMERICA.

TELEPHONE-RECEIVER.

SPECIFICATION forming part of Letters Patent No. 276,723, dated May 1, 1883.

Application filed October 2,1882. (No model.)

I all whom it may concern:

Be itknown that I, GEORGE EDWIN SHAW, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Telephone-Receivers,

, of which the following is a specification.

In the drawings, Figure 1 is a side view of a receiver embodying my invention. Fig. 2 is a vertical section thereof. Fig. 3 is a top or plan view of the same, showing the cap or core removed; and Fig. Iis an isometrical perspective view of the magnet detached.

Like letters of reference indicate like parts.

A is the head, ease, or shell, which has thereon a knob, to, to facilitate handling.

B is the cap, which has a central opening,

6, and the exposed or outer face of which is made flaring or converging toward the said opening.

O and U are binding-posts. I make no special claim to the parts A a B b and (J C, as

' my invention relates to the magnet and its accessories. These novel features I will now proceed to describe.

D represents my improved magnet. This magnet is circular in form, though not a complete annulus, as :it is severed or slit vertically, as shown at c.

E is a horn or extension attached to or forming a prolongation of one pole only, and pro jecting radially inward to or nearly to the center of the magnet, and thence extending vertically upward to receive the spool.

F is the. spool, which is mounted on the ver-' deal or upwardly-projecting arm of the horn E, which serves as a spindleor core for the spool. 3

G is the wire or inducing-coil. One end of the coil or wire G passes to the binding-post O, and the other end is wound to and from on the outside or periphery of the magnet, passing over pins cl d, as shown. It is then carried through the magnet to the other bindingpost, 0.

In order that the part of the wire which is wound around the outside or periphery of the magnet may not be injured by contact with the case, I deem it best to flange the magnet, as shown at e e, to prevent the wire from slip: ping off over the edge of the magnet.

H is an indie-rubber gasket or mat, placed between the base of the magnet and the case A, which serves by its elasticity to secure a closer contact between the upper surface or edge of the magnet and the periphery of the disk I when the cap or cover B is fitted on the case A, and also plays an important part in giving to the magnet a mass vibratiornwhich I believe, in combination with the molecular vibration resulting from changes in magnetic tension, modifies and renders audible fine details of articulation unknown in instruments of ordinary construction.

In the example shown, the magnet I), its

horn E, and the spindle or core are made in 7 one piece, whether cast or forged. I deem that mode of construction preferable; but the born or core can be made in separate. pieces from the magnet and afterward secured thereto in any suitable manner. The magnetization of the incomplete annulus may be effected by temporary contact of its ends (which are opposite to each other at the slit, as described) with the respective poles of a powerful electroma-gnet. It is not absolutely essential that the wire G should be wound to and from on the outside of the magnet D; but I prefer to so wind that part of the magnet, as its magnetic inducing action is thereby modified.

I is the disk or diaphragm ofmagnetic metal. The disk I rests on the upper or outer edge of the magnet D, thus becoming an armature.

I am aware that a diaphragm supported at its periphery bymagnetic poles of unlike name to that opposed to the center of said diaphragm is not new; but in my form of telephone the diaphragm is supported by two opposite poles, which induces in said diaphragm a complex magnetic condition not easily ex plained, but which, in conjunction with the single polarity of the central arm of the magnet, produces more clear and perfect articulation. The iron diaphragm acts in some degree as an armature or keeper with reference to two points, at least, of the magnet-to wit, the two ends of the incomplete annulus. The two poles of the incompleteannulus proper, being bridged by and in contact with the diaphragmarmature, induce therein, as before stated, a

complex magnetic condition. In this condition it then becomes without contact an armature to the central core, becoming still more complex in its condition as it vibrates toward or away from the same, and the mass movement or vibration of the magnet allowed by its elastic support and imparted thereto by but not synchronous with .that of the diaphragm gives clear and due definition to obscure tones, as before set forth. The winding of insulated wire around the incomplete annulus in the line of its polarity, hereinbefore alluded to, adds another useful element to the combination, and adds materially, as demonstrated by experiment, to the effectiveness of the instrument.

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

1. In atelephone receiver, an incomplete annulus permanently magnetic, the magnetic poles opposite each other at the break in said annulus, and having a neutral point nearly diametrically opposite said break, said annulus supporting by its periphery a magnetic circular diaphragm,'and having in its center a vertically-projecting arm conneotedwith one pole only of said annulus, and encircled by coils of insulated wire, substantially as described.

2. In a telephone-receiver, the combination of a permanentmagnet having the form of an incomplete annulus having its poles at"t h'e break,with a core projecting centrally and vertically from one end of the incomplete annulus, carrying a coil of insulated wire wound to and from on the outer face of the annulus, which is electrically connected with said coil, a diaphragm of magnetic material in contact with the annulus, but not with the core, and an elastic support for the magnet, all substantially as described.

In witness whereof I affix my signature in presence of two witnesses.

, GEORGE EDWIN SHAW.

Witnesses: Y

CHAS. S. BATES, I A. S. TAYLOR.

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