US1380981A - Telephone - Google Patents

Description

l. LANGMUIR.

TELEPHONE. APPLlCATION FILED APFLZI, 19H- Patnted Jun 7,4921.

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Inventor: IrvWmui F H is JIttorney To all whom itmwy concrn. Be it known that I, Invms LANGMUJR, a

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- citizen of the United States, residing at Schenectady, in the county of Schenectady,

Stateof New York, have invented certain new and useful Improvements in Telephones, of which the following is a speci- Loud speaking telephone receivers have been suggested having a diaphragm of relatively large surface area to increase the vollune of the soiind without introducing the large surface if constituted of a continuous sheet and acted upon as proposed by a single reproducer element will vibrate in section s'out of synchronism with each other, therebyloweringthe eiiiciency of the sound reproduction.

In accordance with my invention, I have provided a novel diaphragm of large area, preferably of a diameter of at least about two feet which is about the length of sound waves of the most predominant frequency in speech. It is desirable, however, to have the size of the reproducer greater than two feet diameter. .The large area diaphragm which is .us'eful either as a receiver or trans-' mitter, consistseith'e'r of a number of aggregated small diaphragms each with its individual actuating element, that is reproducer or transmitter element, or of a single "Large size diaphragm acted upon by a numer of reproducer or transmitter elements.- Such a diaphragm vibrates as a unit. -When used as a reproducer the sound produced thereby is free fi'om distortion. The advantages of such a diaphragm as a transmitter Wlll be pointed out hereinafter.

In the accompanying drawings, Figure 1 is a diagrammatic sectional view of an electrostatic telephone unit; Fig. 2 is a plan view. of an arrangement of electrostatic units aggregated to form a reproducer of large surface; Fig; 3 is a diagram of electribal connections for a composite electrostatic. receiver; Fig. 4 is 'a' diagram of electrical connections for a composite electromagnetic receiver; 5 is a sectional view of one form of a composite electromagnetic telephone and Fig. 6 is a plan view of part of a composite electromagnetic telephone; i" 7 Each electrostefiis fieteiver, Shawn in a horn. I.

Specification of Letters Patent. Pafignfiedi J7 7'31, 19213,, Application filed. April 21, 1917. Serial No. 163,730.

Fig. '1, consists alternately of sheets 0r an.-

ductive and sheets of dielectric material for example, of foil sheets 1 alternating trostatic diaphragm need not he a plane but may be curved if desired a These electrostatic diaphragms may beef large area, at least of the same order of magnitude as the sound waves, or. as shown Q in Fig.2 a number of units are placed Side by side and electrically connected to form; a resultant large diaphragm. For the sake of 'clearness only a-few electrical connections are shown in Fig. 2, the electrical parallel connection being 1m:

cated in Fig. 3. dicated'in this figure a conductor 5 is connected respectively. to one set of condenser telephone. sheets and a conductor 6 to the condenser sheets of opposite polarity. A telephone current may be delivered tothese conductors by a suitable telephone preferablyconnect,

ma indied in circuit; with an amplifier. For example, I have shdwn a microphone transmitter 7, anda battery 8, connected to the primary windingof a transformer 9.' The secondary circuit of this transformer is connected by conductors 10, 11 respectively to the grid 12 and the filament cathode 13 of a thermionic relay pliotron described in the Proc. of the Institute' of Radio Engineers for September 1915. Inclosed the evacuated en- ,velop 14 of the relayis also a plate or anode .15, the terminals of the cathode 13, and the anode 15 are connected respectively by the conductors 16, 17 to the of a trans-V former 18. Included in circuit with the cathode and anode is a battery 32, the negative terminal being connected to the cathode.

The secondary of the transformer 18 is coir" nected to the conductors 5, 6 in. series with a battery 19, which maintains a definite po tential on'the condensers. r

In Fig. 4.: I have sham a single large area magnetic telephone 2d acted upon by a plurality of magnetic reproducer such for example, as the elements 21, each of which is wound upon a magnetic core 22 and'is electriefiy con- 7 nected to the conductors "The conduetors 23, 2e are. connected asuitable transmitter system, transmitter system similar to that shown in Fig. 3 being shown as symbolic.

Instead of a single large size diaphragm a number of small magnetlc diaphragms, each associated with an individual winding, may be placed side by side to form a transmitter or receiver having a diameter at least as great as the length of the sound waves of the predominant frequency of speech or other sound to be transmitted electrically.

As shown in Fig. 5, the magnetic cores 25 orchestra.

are mechanically supported by a base 26 consisting of wood or other suitable insulating material. As shown, the ends of the cores 25 which may be reduced in section, are inserted into holes made in the base 26, and provided with windings 27. Ad'acent the ends of the magnet cores are fixe magnetic diaphragms 28, held in position by a cover 29 fastened by screws 30. The windings 27 may be connected inparallel as shown in Fig. 4, to the conductors 23, 24 at the binding screws 81. The individualdiaphragms 28 vibrating in unison produce substantially the effect of a diaphragm of the combined area of the combined diaphragms.

When used as a reproducer or receiver the sound volume is thus greatly augmented. When a telephone embodying my invention is used as transmitters sound may be gathered from a given direction with a minimum of disturbing sounds being included coming from other directions, and when it is used as a reproducer a beam of sound is produced and oriented at will. It is also possible to more perfectly gather sounds coming from a large number of units as for example, an When used as a transmitter the conductors 5, 6 of Fig. 3 and the conductors 23, 24 of Fig. 4 are disconnected from the relay transformers and connected to the usual telephone transmission system.

What I claim as new and desire to secure 1 by Letters Patent of the United States, is:

a plurality of telephone elements arranged to act on individual sections of said diaphragm and means for energizing said elements in unison with a telephonic current.

2. A telephone comprising a plurality of face having a diameter of the order of magnitude of at least about two feet, and means vibrating said members in unison in responseto a telephonic current.

3. A. telephone comprising a diaphragm having a diameter at least as great as the length of a predominant wave of sound to be transmitted, a plurality of telephone actuating elements in operative relation to said diaphragm, each of said elements acting upon a diaphragm section proportioned to vibrate as a unit, and electrical conductors connecting said elements in parallel.

4. A telephone having a plurality of diaphragm sections associated together to constitute a compositediaphragm havinga diameter at least as great as the length of a predominant wave of sound to be reproduced. a plurality of electrostatic telephone reproducer elements, each of which is in operative. relation with one of said diaphragm sections and means for operating said reproducer elements to vibrate said composite diaphragm as a unit.

5.- A telephonic device comprising the combination of a plurality of diaphragms adapted to individually vibrate as units, said diaphragms being combined to constitute a vibrating surface having a diameter of at least about two feet and a plurality of telephone elements connected electrically in parallel and arranged to cooperate individually with said diaphragms.

'6. A telephonic device comprising the combination of a plurality of electrostatic telee phones containing vibrating dielectric diaphragms and adapted to individually vibrate as units, said telephones being combined to constitute a composite diaphragm having a diameter of at least about two feet, an electrical circuit connecting the electrodes of said telephones electrically in parallel and an electrical amplifier operatively connected to said circuit.

In witness whereof, I have hereunto set Witnesses:

MAX Wnrsnnon, WALTER A. ROMER.

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