US1721426A - Telephone receiver - Google Patents

Description

y 16, 1929. A. P. vows ET AL 1.72l,426 I I TELEPHONE RECEIVER Filed May 28, 1926 FLg.2

FL I.

Fig.5.

Inventors. Arthur F. 9mm Joseph: Hutt,

Their Attorney.

Patented July 16, 1929.

UNITED STATES PATENT OFFICE.

*AETHUEP. YOUNG, or KENILWORTH, AND osE H .nurr', E COVENTRY, ENGLAND,- ASSIGNORS ro- GENERAL ELEc'rEro COMPANY, A CORPORATION or N W YORK.

TELEPHONE RECEIVER,

Application filed May 28, 1926, Serial N01 112,362, and in Great Britain June 10, 1925.

The invention relates to electromagnetic instruments of the kind having a permanent magnet with pole pieces attached to its ends, and particularly to telephone 5 receivers or transmitters for use in connection with wireless or ordinary telephony or telegraphy.

In the patent of Arthur P. Young, No(

1,628,383, granted May 10,1927, and entitled Telephone receivers, thereis described a telephone. receiver, or the like,

having a pole piece of magnetic material which has been shaped to fit closely around the I end of the permanent mag net on two'opposite sides thereof, and then pressed so as to make a firm connection therewith. The present invention relates to improvements and modifications of the invention 'set forth in the. aforesaid co- 20.pending application and is applicable to loud speakers and apparatus for picking up sounds, as well as to the ordinary telephone receiver. According to the present invention the pole pieces are made of slightly greater width than the permanent magnet or otherwise arranged so that when they are pressed on to the permanent magnet the metal of the pole pieces flows over theedges of the permanent magnet, the former beingsofter.

than the latter, with the result that the permanent ma et is to some extentemb'edded in the meta of the pole pieces, and the pole pieces are accurately positioned with respect to the magnet and are prevented from moving laterally with respect to the mag net. In instruments of this character, in which the greater part of the magnetic system is embedded in, composite insulating material, the latter holds the pole pieces in their correct relative positions. Our present improvement enables the same magnetic system to be mounted in a casing by means other'thaii-molding in composite insulating material.

A further feature of our invention consists in providing one or both of the pole pieces with lugs. For. instance, each pole piece may have one or two 'lugs or lateral projections below the fmag'net by means of which the magnet assembly is secured-to the casing by rivets, screws, or the like. Sim; ilarly one or more lugs or lateral -pro1 ecj-' tions may be provided on one or bothi'pole pieces above the magnet for the purpose-Ref.

attaching a terminal board in the casing below the coils on which theconnections between the coils and telephone leads may be made.

The novel features which webelieve to be characteristic of' our invention are set forth with particularity in theappended claims. Our invention itself, however,- will best be understood from reference to the following. specification 'tak en in connection with the accompanving drawing in which- Fig. 1 is a top plan view of'a'telephone receiver embodying the features of our invention with the diaphragm and cover removed; Fig. 2 is a sectional View taken on the line 2-2 of Fig.1; Fig. 3 is atransverse sectional view of Fig. 2; Fig. 4 is a' top plan view of a'telephone' receiver showing a modification of the invention, the diaphragm and cover being removed; and Fig. 5 is a sectional elevation thereof about the line 5 -5. Like reference numerals are used throughout the drawings to designate similar parts. 7

With reference to the drawings the magnetic circuit includes query-shaped pole;

pieces 11 arranged with their curved portions 12 surrounding the ends of a permanent bar magnet 13 and their straight portions 14 adjacent to one another and on the same side of the magnet. The limbs 14 are spaced above the magnet as at 15 and provided with flat portions 16 which act as seats for the operating coils 17. The width of the pole pieces 11 may be slightly greater than the width of the-permanent bar magnet 13 so that when the pole pieces are pressed on to the ends of the barmagnet the edges of the pole pieces slightly overlie the edges of the magnet, thus forming a pocket and preventing the lateral displacementxof the magnet with respect to the pole pi'c'esr When the pole pieces are made of metal that is softer than that of the magnets, as is usual, then the width of the pole pieces may in the first place'be the same as that of the magnet and, if the pressure applied to the pole pieces when they are in position around the magnet ends is suflicient, the metal of the pole pieces will .fiow slightly inlateral directions over the edges of the magnet, thus again firmly embedding their bases, by which lugs the magnet assembly 'can be screwed into or riveted to the instrument casing 19. Upper'lugs 21 may be formed integrally with the upper portion of the pole pieces, these lugs serving the purpose of carrying a terminal board 22 of insulating material upon which the termi- "nals 23 for the cord 24 are mounted.

In order to cheapen the constructionstill further we may provide only two lugs for fixing the magnet assembly to the casing, say, one lug formed integrally with each pole piece and extending on opposite sides of the magnet; and another lug higher upon each pole piece and extending opposite the other lug thereof, r'or the attachment of the terminal board. This latter arrangement facilitates the use of rivets for securing the magnet assembly-to the casing.

In the arrangement shown 1n Figs. 4 and 5 the magnet assembly is secured by means of a bent "strip 25 passing over the magnet at 26 and riveted to the casing at 27. end of the strip '25 is brought up at 28430 anchor the terminalboard 22 and the other end ofthe strip is arrangedto anchor the two leads of the cord as shown at 29. With this arrangement, it will be noticed, no lugs .net and to form opposed pole pieces.

3. A telephone receiver or like device comprising a casing and a permanent magnet,

-a pole piece embracing one end of said mag net, said pole piece comprising two parallel portions, each of said parallel portions being provided with a projecting lug, one of said lugs being adapted to secure saidinagnet and pole piece in POSltlOIl'lIl the casing and the other of said lugs being adapted to support a terminal board.

In witness whereof, we have hereunto set our hand this 29th day of April, 1926.

ARTHUR P. YOUNG JOSEPH HUTT,

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