US1678200A - Telephone receiver - Google Patents

Description

July 24, 1928'. 1,678,200

M. C. RORTY ET AL TELEPHONE RECEIVER 7 Filed Jan. 5, 1926 I! Ill /6 i 25 JNVEMORs:

M. c. RORTY J c. POTTER it; ,II'I'TORNEYS' Patented July 24, 1928.

UNITED STATES ASSIGNORS, BY MESNE ASSIGNMENTS,

PATENT OFFICE.

MALCOLM o. RORTY, or PARIS, FRANCE, Ann JOHNC. POTTER, or MADRID; SPAIN,

TO WESTERN ELECTRIC COMPANY, INCOR- PORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

T ErHoNE RECEIVER.

Application filed January This invention relates to telephone receivers, and has for its general Object the provision of a'new and improved structure which is simple in construction, and eflicient and satisfactory in operation. 7

The characteristic features of the inven tion will be hereinafter described in connection with the accompanying drawing in which is shown a watch-case receiver having the invention embodied therein, although it is to be understood that it may equally well be embodied in receivers of other types.

In the drawing, Fig. 1 is a sectional elevation on a plane passing through the a'x1s of the receiver; and Fig. 2 is a plan view, with the ear-piece portion of the casing removed, showing the internal parts ofthe receiver.

Referring to the drawing, the internal" parts of the receiver are shown as mounted in a casing, made of bakelite or OlillGP'SHlllable material, comprising a cup-shaped back portion 5 and an ear-piece 6 of forms clearly shown in the drawing, these parts being se' cured to one another by cooperating threaded portions indicated at 7. The permanent magnet structure of' the receiver comprises an iron or steel cupshaped portion 9, and an iron or steel mushroom-shaped portion 10 which is secured to the middle of the inside of the portion 10 by a screw 12.0r in any other suitable manner.

It will be. understood that the magnetic flux, due to this permanent magnetic structure, passes across the annular gap between the edge 14; of the mushroom-shaped magnet portion 10, and the edge 15 of the cupshaped portion 9 of the permanent magnet. This gap is bridged by a pole piece in the form of a soft iron annular cup 17, arranged between the upturned edge 15 of the cupshaped magnetic portion 9 and the edge 14 of the mushroom-shaped magnetic portion .10, except for the fact that a gap of low magnetic permeability is introduced by mea ne of a ring 18 of brass or other substantially non-magnetic material interposed between the inner upturned edge of the annular cup 17 and the edge 14 of the mushroomshaped magnetic portion 10. The mushroom-shaped magnetic portion 10, the brass ring 18 and the annular cup 17 are preferably sweated 5, 1926. Serial No. 79,294.

together; and their relations'to oneeanother will be understood from Fig. 1. Thiscon struction' facilitates the accurate determina tio n, by grinding operations, of the distance between the plane of the topface of the mushroom-shaped portion 10, and the plane of the top of the outer edge of'the annular cup 17," this being an importantmatter, as

thereto by a cap 21 through which passes a screw 22 which extends througha hole in the center of the diaphragm QO-and enters the threaded hole in the magnet" portion 10 with which the other end of the screw 12 cooperates. As clearly shown in Fig. 1. the cap 21 is recessed on its bottom, soas to form a downwardly extending flanged edge which cooperates with the diaphragm above the outer edge 14. of the mushroom-shaped magnet portion 10. In this manner, the diaphragm12O is so held that its edge, and not its center, is free to vibrate. The coil 25 of the wire carryingthe talking current is mounted within the soft iron annular cup 17, the ends 26 of said coil being brought out through holes in the annular cup 17, the cup-shaped magnet portion 9 and the back portion 5 of the casing, or being secured to terminals extending from the outside of the casing portion 5 in a well known manner. The coil 25, being of large diameter. can be of comparatively coarse wire, and still have ade-. quate impedance.

the varying magnetic flux. due to the'coil 25,

In the operation of the telephone receiver,

swings the magnetic fiuX, due to the permanent magnetic structure, bacls and forth across the gap introduced by the brass ring 18 and the air gap between the outer edge of the annular cup 17 and the edge of the diaphragm 20 This, of course, causes the edge of the diaphragm 20 to vibrate, with consequent production of sound waves.

It will be apparent that thereceiver struc ture which forms the subject of this invention, is highly efilcient because the magnetic flux due to the permanent magnetic struc ture is swung back and forth, and is notv Havingdescribed the invention, what is claimed is:

1. In a telephone receiver, a permanent,

magnet structure providing an annular gap,

a soft iron pole piece located in said annular gap, a c011 cooperating with said pole 131608,

and. a diaphragm rigidly supported at its central portion and having its edge-extending into cooperative relation with sand pole piece. v

2. In a telephone receiver, a permanent magnet structure providing an annular gap, a soft iron annular cup cooperating with said .magnet structure and located in said annular gap, a coil located in said annular cup,and a diaphragm rigidly supported at its central portion andhaving its edge extending into cooperative relation with said,

annular cup.

3. In a telephone receiver, a permanent magnet structure providing an annular gap, at softiron annular cup located in said gap and cooperating with said permanent magnet structure, a spacing member'ot substantially nonmagnetic material interposed between one edge of said annular cup and sa d magnetic structure, a diaphragm rigidlysecured at a central portion to said magnetic structure and having its edge in cooperative relation to the other edge ofzsaid annular cup, and a coil located in said annular cup.

4. In a telephone receiver, a permanent magnet structure. comprising a cup-shapedv member and a mushroom-shaped member secured to the center of said cup-shaped member, a soft iron annular cup located in the annular space between said magnet members, a coil located in said annular cup, a

diaphragm extending over the top of said mushroom-shaped magnet member and in cooperative relation to one edge of said annular cup, and means for rigidly securing the central portion of said diaphragm to said mushroom-shaped magnet member.

5. In a telephone receiver, a permanent magnet structure comprising a cup-shaped memberfand a mushroom-shaped member secured to the center ofsaid cup-shaped member, a soft iron annular cup located in the annular space between the edges of said magnet members, a diaphragm extending over the top of'saidmushroom-shaped member andin cooperative relation to the outer edge of said annularcup, a cap extending over the central portion of said diaphragm, and means for securing said. cap to said mushroom-shaped member in clamping engagement with said diaphragm.

6, In atelephone receiver,'a cup-shaped permanent magnet, a plurality of annular magnetic poles for. said magnet, a coil for said poles, a diaphragm, and means forsupporting said diaphragm so that the peripln ery thereof is free to vibrate.v r

7. In combination, a circular magnet, 21 channel-shaped, circular member, the flanges ofwhich serve asmagnetic poles for said magnet, a coil positioned between the flanges of said member, and means for supporting said diaphragmat points removed from its periphery, so that the periphery is free to vibrate.

8. In combination, a magnet, a diaphragm, a circular, supporting member therefor of smaller diameter than said diaphragm and forming one pole of saidmagnet, and an annular channel-shaped memher, the flanges of said member constituting poles of opposite polarity to that of said circular member and a coilin said channel.

9. In a telephone receiver, a circular magnet, a vibratile member, supporting means for said member, said means. constituting one pole of, said magnet and an annular shaped member, portions thereofforming magnetic poles, said poles being spaced relative to said vibratile member and said supporting means to formparallel flux paths.

In testimony whereof we have affixed our signatures to this specification.

'MALcoLM c. nonrr.

JOHN G. POTTER,

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