US1200210A - Transmitter for etheric ir wireless telephone systems. - Google Patents

Description

F. H. MTLLENER.

TRANSMITTER FOR ETHEHIC 0R WIRELESS TELEPH GNE SYSTEMS.

APPITICATTON FILED NOV. 1. 1912.

Patentd 0m. 3,1916.

2 SHEETS-:SHEET 1.

I] im. M

v as kggx uq F. H. MILLENER.

APPLICATION FILED NOV. 7. 191

' Patented OctS, 1916 2 SHTIETS-S-HEET 2.

TTnm-wgmum 79 in s FREDERICK HOYER MILLENER, or OMAHA, ituenhske.

' TRANSMITTER FOR ETHERIC OR WIRELESS TELEPHON E SYSTEMS.

Specification of Letters Patent.

enema Got. a, 1916.

Application filed November 7, 1912. Serial No. 730,623.

phone system, and is designed more particupowerful reproduction at the receiving station.

To this end the apparatus is constructed as shown in the accompanying drawings, representing a typical embodiment of the invention, wherein:

Figure 1 is a perspective elevation show-- ing both the transmitting and receiving apparatus mounted upon a common board or support, the transmitter being on, the righthand half; Fig. 2 is a section on the line 22 of Fig. 1; Fig. 3 is a detail view of the microphone button, supporting'bridge, etc.,

within the transmitter; and Fig. 4; is a diagrammatic illustration of the electrical connections.

In these drawings 1 indicates a board or support, upon which are mounted the transmitting apparatus A and the receiving apparatus B, with such other special devices as may be deemed convenient or necessary.

To the board or support 1 is secured an insulating slab or plate 2, to which are applied insulating binding posts 3, 4, 5 and 6. \7 indicates the usual bracket-arm or su port, such as is commonly employed for t e ordinary Bell telephone transmitter, and 8 the arm hinged or pivoted to said bracket, and serving to support the transmitter.

Formed with, or secured to the free or outer end of said arm 8 by screws or other suitable fastenings, is a head or block 9, conveniently made of circular form, and having a. series of holes or openings 10 equally spaced about its axis, and extending obliquel to said axis through the block or head i rom casing one face to the other, as well illustrated in Fig. 2. These several openings are all at common angle to the axis of the block or head 9', and to the axis of the megaphone horn 11 and mouthpiece 12 carried thereby. Each of the holes or openings 10 in the head or block 9 is enlarged to receive one end of a tube 13, the opposite end of which. carries a shell or casing 14 having the usual telephonic transmitter, preferably of the type or construction set forth in Letters Patent No. 485,311 to A. C. White, dated Novem her 1, 1892. This specific construction is not essential to the present invention, and is merely noted as illustrating one of'many forms of microphonic transmitter suitable for use in this connection. The tubes 13 may be soldered, screwed, or otherwise made fast in the head 9, and should be as nearly alike as possible in all dimensions-length, diameter, thickness, and also in kind and quality of metal, alloy or material. They should be equally spaced, and bear like relation to the megaphone 11 and its mouthpiece 12, and their interior surfaces should form continuations of the openings 10 through the head 9 without shoulder or break, and the inner surfaces of the tubes 13 and openings 10 as also of the megaphone, should be very smooth or highly polished.

The shells 14 each comprise an annular base 15, screwed or otherwise secured to the tubes 13, and a dome-shaped cap or cover 16. Within the'chamber inclosed by said base and cap is arranged the diaphragm 17, with which the microphone button 18 is mechanically connected, said button being carried as usual by a bridge-piece 19 in electrical contact with the base 15, andthrough the latter with the tubes 13, head 9, supporting arm 8 and bracket 7. An insulating thimble or socket-piece 20 passing through the cap 16, and supported upon the bridge-piece 19, carries and insulates a conducting thimble 21, which receives the end or terminal of a conducting wire 22. The thimble 21 is in turn electrically connected with the microphone button 18, or the movable member thereof, by a Wire or conductor 23, as shown in Fig. 3. In other words, the construction and arrangement of parts in the shell or 14: are as usual in transmitters of the type lndicated.

From the binding screw 4 a conducting wire 24 passes to and is electrically connected with the snorting bracket 7 of the arm 8. Mounted upon a shelf or support below.

the bracket 7 and upon the insulating slab or plate 2, is a group or series of open-core transformers 25, one for each transmitter head 14, and from each of said transmitter heads 14 a wire 22 connected as above described, passes to and connects with the primary coil of one or another of said opencore transformers. All of said primary coils primary coils or windings 26, 27, 28, 29,

and. 31 of the transformers 25 are connected in parallel between the conductors 32 and 32" of a local battery 32, or other \source OIL-"electric energy, each primary including n the bridge between said conductors one '"Of the low-resistance, air-cooled transmitters above described, contained within the several shells or casings 14.

33, 3i, 35, 36, 37 and 38 "indicate the secondary coils of the transformers 25, which secondaries are arranged in parallel between the conductors 39 and 40, through which the transmitting apparatus is connected with the wave-generating apparatus of the system. A condenser 41, of advisably two microfarad capacity or thereabout, is introduced into the line or conductor 39, and a like condenser 42 is introduced into the conductor 40, as indicated.

As the present invention pertains solely to the transmitting apparatus above described, it is deemed unnecessary to show or describe more of the ethereal system as a whole. Details of said complete system are duly set forth in the earlier applications hereinbefore referred to.

Briefly describing the purpose and action of the present invention, it will of course be understood that the person desiring to send a telephonic message speaks into the mouthpiece 12, the sound waves being directed thereby into the megaphone horn 11, wherein by reason of the successive reflections of the sound waves from side to side of the horn or funnel, and the vibration or amplification of the sound is more or less uncertain, the fact that it takes place is well established, and is recognized by physicists. From the horn 11 or body of the megaphone, the sound waves pass by the tubes 13 to the diaphragms 17 of the respective micro-telephonic transmitters, and thence by the wires or conductors 22 to the primary imposed or impressed upon the current flowing through the conductors 39 and 4H. and ultimately upon the ethereal .waves through or by which the signals are transmitted through space.

Byemploying a plurality-of microphonie transmitters, all communicating with the.

single mouthpiece and megaphone, I am en abled greatly to intensify or strengthen the effects produced in the electrical conductors. and finally impressed upon the ethereal waves. As a consequence, clear and intelligible transmission of speech results.

Seemingly, each separate microphonic transmitter, with its transformer, operates with the same efiiciency when grouped and arranged to receive sound waves from a single mouthpiece and megaphone as when but one such microphonic transmitter is used, and there is consequently impressed upon the electric current the aggregate effect of the several microphonic transmitters. The megaphone serves to deliver to each of the transmitters a like series of waves, or in other words, effects an even and perfect distribution thereof to the several transmitters, causing them to act in perfect harmony and with uniform effect.

The arrangement of the tubes 13 in relation to the megaphone horn 11 issuch that the sound waves are projected into and through said tubes with a minimum of deflection, while the angle of the tubes to the axis of the megaphone is ,such as to separate the microphonic transmitters only sufficiently to clear one another, and thus to make the plural transmitter compact and symmetrical.

The several binding posts 3, 4:, etc., are employed for convenience in making the appropriate connections between parts of the apparatus, as usual;

While multiple telephone transmitters have heretofore been used to secure a more intense energy of transmission the success of such prior multiple devices has been limited by the reduction in the intensity of action of the sound waves on the individual diaphragms and by possible interference and echoing in the common passage leading from the mouth piece to the transmitters. I have found that by interposing a megaphone between the mouth pieee and the group of transmitters and symmetrically arranging the latter I can intensify the ef fect of the sound waves on each transmitter diaphragm and secure true synchronous action without any disturbing effects of the character mentioned.

While the specific embodiment of'my invention here illustrated and described has given yery satisfactory results, and is the best form now-known to me, it. is obvious thatthe general principles of construction and 'operationherein set forth may be incorporated in structures of somewhat different form and ,detail. I therefore do not desire to be restricted to the specific construction ordetails herein set forth, but consjemplate such reasonable variations as would naturally be made by skilled mechanicians and electricians in the practical ap- ,plication and use of my invention. 1 Having thus described my invention, what I claim is 2-- l 1. A telephonic transmitting apparatus "f comprising a mouthpiece; a megaphone or y i f horn; a head or block joined to the delivery ab :end of the megaphone, and having a plurality of openings through it in the general direction of the axis of the megaphone; tubes applied to of said openings; t ters carried at the free ends of said tubes, one by each tube, substantially as described.

2. In a telephonic transmission of sounds, the combination of a central head or support bearing a series of substantially identical tubes symmetrically arranged; telephonic transmitters carried one by'each of said tubes; and a megaphone applied to the supporting head the several tubes,

it I ,;*6opiee or this patent may be obtained for and forming contmuations and telephonic transmittransmitter for ethereal common tohaving its larger end toward the transmitters whereby a amplifying chamber is formed. L

3. Incombination with a bracket 09in?- port, a head or block in electrical connection therewith having a series of symmetrical y arranged passages or openings; a series pt tubes each communicating with one other of said openings; a series'of telephonic transmitters carried by the respective tubes, one by each; a megaphone, the delivery end; of which is common to the several tubes,

and

symmetrically arranged with reference thereto; and phone. i

4. A telephonic transmitting apparatus comprising amouth or a gregate efiect.

g whereof I have signed my In testimony name'to this specification in the presence of two subscribing witnesses.

' t FREDERICK HOYEB MILLENER. I

- "Witnesses:

F. J. GRIFFIN,

R. H. 'BALLANTINE,

five cent: each, by addreuln'g the Commissioner 0! letelte, Washington, D. 0."

a ,mouthpiece for said mega-

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