US341000A - Telephone-receiver - Google Patents

Description

Ulllllllllmllm (No Model.)

J. T. GUTHRIE.

TELEPHONE RECEIVER.

No. 341.000. Patented May 4, 1886.

UNITED STATES PATENT OEEIcE.

JAMES T. GUTHRIE, OF LEESBURG, OHIO.

TELEPHONE-RECEIVER.

aPEcIPiCa-TION forming part of Letters Patent No. 341,000, dated May 4. 1886.

Application filed November 10, 1885. Serial No. 182,326. (No model.)

'make and use the same.

My invention relates to an improved telephonie receiving apparatus designed especially for use with direct electric currents, or such as are not intermittently reversed. It is,however, capable of being operated by reversed currents, or such as emanate from the secondary coil of an inductorium.

The objects of my improvement are to enable articulate speech to be communicated by means of electricity over greater distances than heretofore deemed practicable, and to render the spoken messagesloud and distinct when received.

lVith these ends in view my invention consists'in a receiving-telephone composed of a suitable trumpet-like case, a metallic diaphragm mounted across the enlarged end of said case, and a permanent magnet arranged within said case to attract the diaphragm, and having a coil of insulated wire mounted on each end, said coils being connected in multiple are to two common terminals arranged for circuit-connection.

The construction and operation of my new receiving-telephone will be readily understood from the following particular description in connection with the accompanying drawings.

In the drawings, Figure l is a front view of a telephone subse1ibei"s-station apparatus comprising my improved receiving-telephone and its adjunets. Fig. 2 is a diametric section through the case and diaphragm of the receiver, but showing the interior parts in full lines. Fig. 3 is a diagram illustrating the electro-magnetic construction of the receiver.

Referring to Fig. I, at the top of the back board, A, is mounted an electric bell, B,whieh is of ordinary construction and need not be here particularly described. T is the transmitter,C the battery-case, and E the circuitbreaking device for calling purposes. R designates the receiver.

Referring now particularly to Fig. 2, I will first describe the construction of receiver R in detail, and explain the same with reference to Fig. 3. larged at both ends, and at one end is provided with an ear-piece, I?,whiel1 hasa fiange orlip, p, embracing the end of the case snugly, and preferably lined with velvet or similar cloth to give it adherence. At s the ear-piece has an annular shoulder, and between this shoulder and the adjacent end of the case is clamped the diaphragm D. Inside of the case is a bar permanent magnet, M, having one pole near the diaphragm and the other pole near the other end of the case. On the diaphragm end of the magnet is a coil, K, of ine insulated wire, and a similar coil, K', is on the other end. 'Ihe inner terminal of coil K isrconnected to the outer terminal of coil K, and the inner terminal of the latter is connected to the outer terminal of the former. The double terminals thus formed are connected to the binding-postsp and p,respeetively,so that the two coils will thus be in multiple-are connection with wires which may be connected to posts p p. A current passing in the direction of the arrows No. l, through the wires L and L to and from the receiver,will divide at the junction y ofthe coil-terminals and reunite at the junction i', a quantity going through each coil in proportion to its resistance. The resstances should be equal. The coils are so wound and arranged upon the magnet that when the lcurrent through one coil tends to reenforce the magnet-pole which it surrounds the current through the other coil partially neutralizes the other pole. Now, ifa current is used which ilows only in one direction, and is simplyincreased and decreased in strength or varied in response to sound undulations, the current action which strengthens the magnet-pole nearest the diaphragm weakens the other polc,and the magnetic field is shortened and condensed near the diaphragm, and the attraetionof the magnet for the diaphragm is much greater than it would be if its iield were not so condensed. At the same instant the field is weakened atthe opposite pole, there being no necessity for strong attraction or any other magnetic action at such time at that The trumpet-like case r is en' IOO point. however, the rear pole begins to gain strength as the front pole loses it, and the magnetic ield near the diaphragm becomes weakened by attenuation, resulting from extension and from the loss oi' the exciting induencc of coil K, so that the diaphragm is so much relieved as to make a very free outward half-vibration as the result of its natural resilience. The coniplete vibrations correspond to variations of current strength, and by means of my improved transmitter, described and claimed in another application, the impulses varied in strength are all caused to flow in the same direction. XVhen the two coils act upon the magnet in opposite directions,there is occasioned a torsional strain which tends to induce in both coils additional currents which react upon the magnet, and thus rcenforee the impulses which come from the transmitter.

On the rear end of the trumpetlike casing` is a metal plate, I, through which passes an adjusting-screw, i', which screws into the .rear end of the bar-magnet, and serves to adjust the same withrelation to the diaphragm. The screw has a collar, z", which prevents it from moving longitudinally through the plate.

Vhile I have described my receiver as bcing especially adapted for operation by nonalternating currents or undulations, it may be also operated by the alternating or reversed currents such as are sent by transmitters using induction-coils.

Vhen the current begins to weaken,

I do not confine myself to the arrangement of coils as heretofore described, and as shown in my drawings, as they may be so arranged that they will simultaneously strengthen and simultaneously weaken the 1nagnet-p0les which they surround, respectively.

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

l. In areceiving-telephonc, the longitudinally-adjustable straight bar1nagnet having 4coils arranged upon its opposite ends, and connected in multiple are, and arranged to have opposite effects simultaneously, essentially as set forth.

2. The receiving-telephone composed of the trumpet-like casing, the diaphragm, the straight bar-magnet longitudinally adjustable within said casing, and the coils on opposite ends of said magnet and connected in multiple are, said coils being arranged to have opposite effects simultaneously, essentially as sct forth.

In testimony whereof I have signed this specification in the presence of two subscrib ing witnesses.

JAMES T. GUTHRIE.

Ti t n ess es W. T. HovAN, L. L. SEcRrsr.

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