US207269A - Improvement in speaking-telephones - Google Patents

Description

E. GRAY. Spe@Lking-Telephone.

No. 207,269. Patented Aug. 20,1878.

UNITED STATES PATENT OEETcE.

- 1 ELIsnii GRAY, or el'iidxco, itmxois.

`IMPROVEMENT iN SPEAKINGfTELEPHONS.

Specitcation forming pnrt of Letters `Patent N 207,2G9,'dated August 30, l-n; appliraticn tiled J une 20, 1678.` Y

To all 'whom it may concern:

Be it known that I, ELIsHA GRAY, of Chicago, in the county of Cook and State -of Illinois, have invented certain new and useful Improvements in Apparatus for Generating, '.liansxnitting, and Reproducin g Rhytlnnical Vibrations, representing spoken words or vocal sounds, in an electric circuit, of which improvements the following is a specification:

My present invention more especially relates to and constitutes an improvement upon my bipolar telephone, for which Letters lat ent of the United States No. 204,029 were granted to me May 21, 1878, which patent showstwo telephones so combined witlra bifurcated mouth-piece that each is actuated with equal force,'thereby greatly increasing the electro-motive force which generates the rhythmical vibrationsV representing the vocal sounds or words articulated or spoken into the telephone.

The object of my present invention is still further to increase the 4electro-motive force or rhythmical genera-ting capacity of t-he telcphone, and to secure an increased volume and clearness of sound, while preserving the portable features ot the instrument, so as to enable it to be handled with facility; to which ends my improvement consists in certain novel combinations, constructions, and organizations of parts, hereinafter specifically claimed.

The aecompanyin g drawings represent so much ot my improved instrument as is necessary to illustrate the subject-matter herein claimed, as constructed in the best way now known to lne. Obviously, however, some ofthe improvements may be used without the others, and in apparatus differing somewhat in its details of construction from those of that herein shown, without departing from thc spirit of my invention.

Figure 1 represents a plan or top view of a bipolar telephone with its diaphragms and electro-magnets duplicated, and arranged in reverse order on each side'of each ofthe poles of its permanent magnet. Fig. 2 represents a side elevation, partly in section therethrough, on the line 2 2 of Fig. 1, showing the details of the method of constructing and connecting eachA pair of the diaphragms.` Fig. 3 represents the arrangement upon circuit of my im; proved apparatus.

The details of construction ot the present apparatus are substantially the same as those of my bipolar telephone hereinbefore meltv The soft-iron core D is made tubularand extends through the pole of the permanent magnet 011 each` side, so as' to receive Aa supplementary helix or wire coil, C', in addition to the usual one on the opposite side of the pole.

A secondary diaphragm, E', is mounted in front of the supplementary electro-magnet in precisely the same manner as its corresponding diaphragm, E. The arrangement of the seconda-ry magnet and its diaphragm relative- .ly to the pole is, however, it wiil be observed, i,

reversed, so as to bring the electro-magnets next the pole and between the diaphragms. The secondary cap F, which protects the diaphragm E', is made solidf-that is, it has no opening for a month-piece, such construction being unnecessary in this instance.

The core D has a small hole drilled through it from end to end, about one-eighth of an inch in diameter. A light rod', d', of wood or some Anon-magnetic meta-l, (sue-h as brass, for in.,-

stance,) passes through this opening,iuwl1ich it is capable ot moving freely endwise..i Each end or" this rod is attached to its respective diaphragm E t", so that the movement of one from any cause whatever produces corresponding movements or vibrations in the other'.

rlhe obvious advantage of my improvement is, that I am enabled, under the organization of i part-s above described, to vibrate two diaphra gms in front of two electro-n1agnets, both of which `are charged from the same pole of the permanentmagne ,withoutmaking any change in'any respect in the bifuroated mouth-piece shown in my bipolar patent, above mentioned. I have demonstrated by experience that by this method I can generate much greater electro-motive force than could be done by the employment of a single diaphragm, and am,-

consequently, enabled to produce amuch louder and clearersound.

A similar apparatus is attached to the other pole of the permanent magnet, and I am thus enabled to vibratefour diaphragms instead of two, as in my bipolar telephone, above mentioned, and still retain the same relation between the diaphragms and mouth-piece, as in the aforesaid instrument. v

The arrangement upon circuit which I deem most advantageous is one which keeps all the magnets permanently charged, which -is preferably' done (where. a permanent magnet is not used) by 'working with what is known as a closed circuit, such as that shown in Letters Patent of the United StatesNo. 186,340, granted to/me January 16, 1877, or inA two applications forLetters Patent respectively led by me October 29, 187 7, 1,) and January 17, 1878. e

The operation ofthe apparatus. will readily of the United States, (Oase be understood from )the foregoing description.

A I do not broadly, claim hereinA vibrating a secondary diaphragm from aprimary one, nor the combination of a magnet, two diaphragms,

and an interposed air-tight chamber, as these subjects-matter are embodied 'in another application iled by me May 8, 1878, of'which'this is a division, but limit the claims to' the combinations specified.

poles, a wire coil or pole, and a diaphragm for each helix;

I claim as my invention-- t V 1. A secondary magnet, in combination with a secondary diaphragm, actuated by a primary diaphragm through the intervention of a conmeeting-rod, substantially as hereinbefores'et forth, toincrease the electro-motive force of the vibrations. l

2. In combination, diaphragme mounted. thereon,

a permanentV magnet,

and electromagnets interposed between the diaphragms,-

so that the diaphragme are actuated by'two magnets of similar polarity. l y

i 3. In combination, a permanent magnet,.a tubular soft-iron core mounted *on each of its helix on each side of each 4; The combination,substantially as hereinbefore set forth, of a mouth-piece, a primary diaphragm, a -secondary diaphragm actuated thereby, and a sold cap or cover inclos'ing the Ems-'HA GRAY.

f Witnesses:

l A. G. Swmrwour, D. M. ER'SKINE, Jr.

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