US1027494A - Telephone-receiver. - Google Patents

Description

G; MoMEBN-- TELEPHONE RECEIVER. i APPLICATION FILED APB. 28, 1910.

I 1,027,494, Patentea'may 28,1912.

mum v' sAMuELe. McMEN, or. FRANCISCO, CALIFORNIA, AssIeNOn rIo McivIEN a MILLER, or CHICAGO, ILLINOIS,

' l -To all whom t may concern.:

Be it 'known that I, SAMUEL a citizen of the UnitedStates of America and a resident of San'Francisco, county of San Francisco, and -State of California, have invented anew anduseful Improve ment in Telephone-Receivers, of which the following is a specification.

My 4invent-ion pertains to telephone ref c'eivers, in common battery or centralized energy In such systems, in order that the 'substation apparatus may be of the simplest type, it is convenient tok permit the current which iows .upon the telephone line during conversation to flow through the telephone receiver as well. This-is .objectionable when, thereceiver is of the ordinary construction,

comprising in nearly all and many devices,

circuit wiring external cases apparatus and to the receiver itself, have been devised, and

- 'sdnme otthem have been used -successfully, tOv

prevent the undesirable elects produced by the current flowing through thel receiver. VIn some of these devices, direct Current is prevented from flowing through the receiver, and in Others itis greatly reduced.

.An element in the construction of the usual type of receiver is the permanent mag net. This in `my improved receiver vIreplace by an electromagnet,

In order that the vdirect current of the telephone line may low through the' re' c eiver, and that 'the' simpliedcircuits possible under such a conditionl may be used, I make a receiver havinga speech-current translating coil andhaving an electromagnetic tield coil, and I then provide means within 'the receiver case for separating the currents of the telephone line into-direct currents, the path of which includes the field magnet coil; and'speech currents, the

.path of whichincludesthe diaphragmactuating or speech-current 'translating coll.

In the drawings which accompany and form a part'of this specication-Figure 1.

shows a sectional elevation through my improved receiver; Fig. 2 shows an enlarged section of the upper part of my receiver; Fig. 3 shows a plan view of the under side of the magnetic devices; Fig. 4 shows diagrammatically the circuit arrangement;

and particularly to receivers for use it, thus holding it securely in place. terminals of the condenser -are arrangedl upon the end nearer the large end of the l lwasher -sir'ed initial magnetic strength at the upper.l

end-of the core' 9.' Thus, the initial mag- 95 A CoPAR'INERsHIr.-

' Speciication'of Letters `Patent; i vlateinted May-28,1912. 'Aplilicaton fneaaprn 28,-1'910. seriarNq. '558,238'

Iig.- 5` shows diagrammatically 'an alternative form'of my device, using one coil in-I` 55l stead of two. Like figures refer the several views. l

The receiver case is composed of three in body 1, which may-be a casting ory a turned piece, is an' annular'internal rib 'l'.

A rolled condenser 4 is rolled upon la fiber tube 5, thus making a tubular condenser'. This condenser isinserted into' the receiver 65 case -from the small end, andy is'clamped-by' the end piece 2, whichis screwed down upon The receiver.` The electromagnetic system'of the receiver comprises a pressed magnetic cup, two helices containedA thereby, a magnetic core, a magnetic washer and a magnetic diay` -Terminals are mounted "upon the phragm.

exterior ofthe magnetic cup, andthe coils,

core and'washer are mounted within thecup, the diaphragm being placed over the mouth hereof, and both cup and diaphragm, 8O I clampe between 'parts 1 and 3 of'thereceiver, all as shown lclearly in the drawings. Coil 6 is the field coil of the receiver, `which that 'constant ,magneti sm 4required.- to place stress. The magnetic washer '7, together with the smaller cylinder 8 of the magnetic 1 cup," form a magnetic circuit very nearly closed, and give a vervhigh inductanc'e value to the coil 6, and 'i atfthe ysame time 90 producethe' required'magnetism at the uppei` end of the core 9`. Thedimensions of 7 may be such as to permit the denetic strength. may be controlled in the design and manufacture.

' The coil 18 is 'the actuating coil of the de-v vice and is made of iat form and located in close proximity to the diaphragm, so that 12 and 13,' which servev as a `means for c'on- 105 necting the coils and condenser in circuit, as

to like parts throughout i the diaphragm under' an initial 85 i shown inFig. `4. One terminal of coil 6 is ductors 20 and 21 of the receiver passthrough'the receiverin two paths, the rst brought out through the cup8 and soldered to the terminal 11; one terminal -of the oo ndenser 4 is connected to terminal 11 ;while one terminalv of coil 18 is led through the magnetic cup and connected to the terminal .13, the remaining terminal of condenser 4 being also connected-to terminal 13; and the remaining terminals of coils 18 and 6 are 4led through the cup 8 and connectedto terminal. 12. The circuits -of the device are clearly shown in Fig. 4. The incoming conof which includes only the eld winding 6 in the shape of a long, slender cylinder about the core, and the second of which-includes condenser 4 and the winding 18 in the form of a very short cylinder of comparatively large diameter..

Because of the fact relatively narrow and-is in a` path carrying direct currents, some of the lines of-force generated' by the current through that winding will closethrougli the magnetic-washer 7 and some will close'through the center of 4the diaphragm, but in general it is intended that the magnetic circuit of the winding 6 is notformed wholly through the diaphragmL 30 The winding 1&8 carries speech currents, and this windingis made relatively thin, so that the diaphragm and the bottom of the shallow portion of the cup. are separated by'I but a smalldistance, thus` not concentrating lthe forces at the center of the diaphragm.

With sucha construction, even if the'centrai core fwere to be "removed, there would f renain a tendencyfor the two sides of the .magnetic circuit sodescribed to draw to# gether under the influence 'of any current,

other magnetic conditions being'absent; and while the centerfof the diaphragm is 'free to move and vis under the influence of a greater force to make it move, there is such a' tenddency in some degree, throughout the area occupiedby thewinding 18, f f

In all forms oit-telephonel receivers which.

have come into general commercial use, the

diaphragm is influenced at or near its centeronly, whether there be both or onlyA one of. the poles presentedl to'that"poi tion kof it. f

.l While my present invention does concentrate the forces at about the fcente'r ofthe hat the winding 6 is currents Aof higher frequency, after they have frequencies and lower'amplitudes. Whileitf is of importance that-transmission lines be so constructed `as to. reduce the lossesl due to attenuation and distortion, 1t is also ini- .portant -soto construct the receiving device as to be lresponsive to what remains of the been subject to such losses as have occurred in the line. .l "r A yLA relation exists between a diameter of the'reciver diaphragm and the frequency'of voice current to which the receiver-is most readily responsive.

inches or more in diameter and a cup of similar size, I- do not consider it essential that so great diameters be used.- Satisfac`- tory commercial results are secured by dia While, therefore, my 4drawing shows in scale -a diaphragm of two phragm and cup diametersof the order of one inch. 'Such a modification of the general magnitude of these parts should be ac' companied-by a similar modification in the shell of the winding 6, so that the winding 6 may, in general, be long and narrow, while l the winding 18 may, in general, be wide and thin.

Fig. 5` illustrates an alternative form of 4my device, in which a permanent magnet is n' utilized instead of an electromagnet, and direct currents are .prevented from passing -through the actuating coil by means ofthe Lcondenser 4 retained within theha'ndle of ithe receiver, as described in the foregoing l and characteristics asdescribed.

Having thus described my invention, what specification, the condenser in this form of my device being of the same general shape I claim as new and desire to se'cure'by United States Lettersipatent is 1. In a telephone receiver, a case of'three parts; an internal annular rib upon the body j p art of said case; a condenser between said l rib and the second-of said parts, forming a `cap upon one end of the receiver; .and an .electromagnetic system clamped between .said-receiver body andthe third of said f parts, forming a cap upon the other end of the receiver.

2. In "a' telephone receiver, a removable end cap; an internal abutment member; and a condenser within the receiver, and reftainedv by said ca p andsaid abutment member.

3. In a telephone receiver, a case; a tubularcondenser within said case; an electromagnetic system within said case; and a flexible conducting cord passing through the i middle of said condenser and connecting to said electromagnetic system andto said condenser. c

4. In a telephone receiver, 'a case; a magnetic cup; a diaphragm closing the lmouth of said cup; a helix within said cup; a condenser within said case, and connected electrically with saidwhelix.

5. Inv a telephone receiven'a magnetic oup Signed by me at San Francisco, county of in the shape of two coaxal'cylindroal oham- ASan Franolsoo and State of California, in bers; a magnetic' diaphragm closing the. the presence of two witnesses.

mouth of said cup; a magnetic core in the SAMUEL G. MCMEEN. 5 axis of said cup; and a -washer upon said` `Witnesses:

core, located at or near the division plane of GERTRUDE COHEN,

said two coaxial cylindrical chambers. Y FREDERICK L. BAER.

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