US1585699A - Watchcase receiver - Google Patents

Description

May 25 1926. 1,585,699

J. A. sTlRLlNG WATCHCASE RECEIVER Filed Dec. 1, 1924 Patented May 25, 1926.

UNITED S'IATE-sv PATENT OFFICE.

N JAMES A. sT1nLrNG,'- or ELKHART', 1NDIANA,fAssIGNoR, BY MEsNE ASSIGNMENTS, To CHICAGO TELEPHONE SUPPLY COMPANY, or ELKHART, INDIANA, A CORPORATION F DELAWARE.

WATCHCASE RECEIVER.

Application led December 1, 1924. Serial No. 753,323.

My invention relates to telephony and more particularly to a telephone receiver of the watch case type. I

Receivers Ot this general type are now commonly employed in the head set or head phones for'radio reception.

It is desirable, to make the head phone as light as isconsistent with good r-eception- It is also highly'desirable to have the receivenas for the convenience of the wearer.

sensitive as possible and to secure, as nearly as possible, uniformity in, the output in order that the two receivers of a given head set maybe matched in tone and receiving characteristics.

It is furthermore highly desirable to de sign the parts of a device of this character so that assembly may be accomplished in a simple and inexpensive manner with .the

assurance that-the resulting structure will be properly and permanently assembled and that the successive units of assembly will be uniform in character,

According to my invention, I provide a 5 metal aluminum shell or case which has its plate improves very decidedly 'the quality of`reception of the receiver, being spaced closeto the diaphragm and operating like a soundingboard on the sound waves generated by the moving diaphragm. The magnetic systemis mounted on this tone plate and is otherwise free of contact with the vstress upon the diaphragm, and uniformity.

of tone in sound production.

I provide other incidental mechanical improvements which will be apparent from the following detailed specification. f

In the accompanying drawings I have illustrated an embodiment of my invention which will teach those skilled in the art how to construct and operate a device in accordance with my invention.

In the drawings: Figure n1 is a planview of a device showlng the diaphragm removed and ythe gear speed in section. This figure is taken on the line 1 1 of Fig. 3;

Fig. 2 is a section taken On the line 2-2 of Fig? 3, showing the magnet system in ,bottom plan View;

F ig."3 lis a transverse section taken on the line 3-3of Fig. 1;

` F ig. 4 is a transverse section taken at right angles thereto and. on the line 4-4 indicated in Fig. 1;'

Fig. 5 is an isometric View of one of the pole pieces;

Fig. 8 is a fragmentary section through 80 one of the inserts in the terminal block; and

- Fig. 9 is a diagrammatic illustration oi. an

embodiment of the illustration.

lustrate my invention comprises 'a shell 10 which is drawn sheet aluminumof approximately 14 gauge. This shell has a back or bottom plate 11 with a cylindrical rim dared out as indicated at 12 to a larger diameter providing the threaded portion 13. The inside Of the threaded portion lis carefully finished to the desired diameter andthe threaded portion 13 is adapted to receive the threads of the cap 14, which cap is screwed Adown to hold the diaphragm 15 and the The -receiver which .I have selected to ill tone plate 16 with its connected parts in position.` The tone plate 16, which also may be termed an assembly plate, has a raised rim17 which is stamped up1 about a 32nd of an inch above the central portion of the .plate This plate 16 also has a central aperture18 through which project the free ends or upright ends of 'the pole pieces 19. The plate 16 has three screw holes 20, 21 and' 22 therethrough, which are threaded ,to receive clamping screws 23, 24 and 25, respectively, for holding the magnet'system and the terminal bloei, respectively, upon the assembly terminal block 28 to hold the same against.v

rotation. The terminal block 28 is made up of a pair of stampings of fibre, or the like; with the screws passed through thecenter of the same and holding the block upon the late 16. The terminals themselves are ormed of sheet metal washers 29 having the integral ears 30 to which are connecte CFI the ends of the windings of the coils. These terminal washers 29 are held in place upon the block 28 by means of an insert 31 which is formed of a threaded brass thimble, the outside of which is knurled. This thimble is pushed into registering openings in the two parts of the terminal block 28 to hold the same together. The sleeve 31 has a head which engages the washer 29 and holds the same firmly in electrical and mechanical Contact. Suitable screws 32 are threaded into the sleeves 31 and the terminals of the flexible cord 33 are fastened under said screws 32. The casing or shell 10 has an aperture at 34 for the flexible cord shown at 33.

It will now be'seen that by means of the single screw 25 threaded into the hole 22 in the plate 16, and the struck up lugs 27, the terminal block 28 is held firmly in position upon the plate 16.

The magnet system which is assembled.

upon the plate 16, comprises the permanent horse-shoe magnet 35 formed preferably of rectangular cross section with the 'sides` thereof ground parallel. This magnet is bent into circular form and the ends thereof have openings through which the screws 23 and 24 pass to mount the magnet system upon the assembly or tone plate 16. f'

The pole pieces of the magnets 35 are separated from the assembly plate 16 by means of the collars oi'posts 36 which serve to bring the ends or upright parts of the pole pieces 9 the proper distance from the'diaphragm 15. As heretofore explained, the magnets 35 arecarefully ground to size.

The pole pieces 19 comprise the base portion 38 and the upright end portions 39. The base portion 38 is provided with a hole 40 through which passes one of the screwsd 23, 24 to clamp the pole piece to its appropriate magnet pole.- At the junction of the base with the upright, I have struck out a lug 41 which lug cooperates with the corresponding lug on the cooperating pole piece. That is to sav, the pole pieces 19 are made in leftfand right pattern with the lugs meaeee of the upright portion being-riveted over slightly t'o hold the windings inf/place. In the assembly of the parts, the windings are assembled upon the pole pieces and then the pole pieces, the magnets and the posts are assembled upon the 'mounting plate 16.

.Now, it will be observed that in drawing the screws 234 and 24 tight, there may be a tendency to buckle the mounting plate 16, particularly in the vertical line 4 4 shown in Fig. 1,v and it is to prevent this that the reenforcing or stamping at 26 has been resorted to. There is not as much tendency to distort the lower part of the plate 16 since the terminalblock 28 Offers' resistance to bending in one direction. I find that the stamping and offsetting of the portion 26 considerably strengthens this plate without interfering witlr its function as a tone plate.

Afterthe parts have been assembled in place and the washers 29 and3() connected to the windings 44, the air gap between the upright ends of the polepieces 19 and the diaphragm 15 is carefully ground to a predetermined size, the raised rim of the tone plate upon which the diaphragm seats, be-

ing also ground off in a-parallel plane so' as to afford a good seat for said diaphragm 15.

" It will'be seen from the above that I have provided a structure which is easily and inexpensively manufactured and assembled and which is capable of manufacture with the assurance of uniformity of the product. The windings 44 are preferably 4made of enameled Advance wire so that the resistfr ance thereof does not change appreciablywith temperature.

The employment of the auxiliary magnetic gap 42, which is illustrated diagrammatically in Fig. 9, gives the receiver unique characteristics. Due to the auxiliary gap 42, there is not the tendency for the magnet 35 to` weaken if permitted to remain without a` proper keeper. Also due to this auxiliary gap, the upper ends of the'pole pieces are much freer magnetically to have the flux therethroug vchanged by the windings 44, than would-be the case where such auxiliary gap were not provided. That is to say,

assume that the flux of the permanent magnet 35 is a constant, a certain portion of the same will pass through the main air gap through the diaphragm 15 and back to the shown or described.

`cooperating pole piece, and another part of the magnetism'will tend to pass through the aii ap 42. j

O viously if the iux through the upper ends oi' the pole pieces above the gap 42 is to be varied, some means should be provided for permitting such variation to occur with a minimum of effort. That is to say, if no auxiliary gap were provided then the magnet lines of force could be choked out of the pole pieces only bymain strength of the current going through the windings 44. In the structure of my invent-ion it is not necessary :t'oi the luxto be changed in the permanentl magnet 35, the path which the liuxv takes being merely shifted. lHence, upon a very slight opposition to the liow of magnetism up through the main air gap,

'suoli magnetism may be diverted lto the auxiliary gap 42.4 'llhus a very sensitive receiver is provided and the condition of sensitivity is inherent in the structure. The auxiliary gap 42 is greater than the sum of the two main air gaps. Also, there is less danger of the permanent magnet 35 weakening through the course of time, because of the auxiliary gap 42.

l do not intend to be limited to the details ll claim:

1. lin a telephone receiver,.a shell ofshee metal drawn vinto a cup, said cup having the rim thereof iared out, said rim having its periphery threaded, the edge of theI cup forming a narrow seat, a tone plate formed of relatively thick sheet aluminum having a plane peripheral edge forming a relatively wide seat for a diaphragm, a diaphragm on said seat, a capthreaded on said cup and clamping the edge of the tone plate and the diaphragm, said tone plate having itsk central portion depressed slightly below the diaphragm seat, and a magnet system `mounted upon the tone plate and projecting through the same into proximity to the diaphragm. f t l f 2. ln combination, a cup, a cap threaded to the edge of the same, a sheet metal tone plate comprising a planar rim providing a wide seat, a diaphragm on said seat, the body of' the tone plate being depressed a short distance below the -rim,.. said Abody having an opening through the. center, a magnet system clamped to the plate and projecting through said opening, a terminal block mounted on said plate,-a screw passing through said terminal block and threaded into said tone plate, said tone plate having integral lugs struck down into contact with the vblock to hold the same against turning. f`

3. A tone plate comprising a sheet of aluminum having a Araised fiat edge forming a diaphragm seat, said plate having a central aperture for the magnet system, the

edge ot' lthe aperture being ycompressed. by stamping to harden Jrhe same.

4. A tone plate comprising a sheet of aluminum having a raised flat edgeorming a diaphragm seat,.said plate havmg a central aperture fgr the magnet system, the

edge of the aperture being reinforced, and integral lugs struck down from the edge ot the aperture for engaging aterlninal block.`

5. A magnet pole piece for a watch case receiver comprising .a sheet metal stamping consisting of a base portion adapted to' engage the pole of a permanent magnet and an end. portion lying in a plane at substantially right angles to the plane of the base portion,` said end portion having an integral lug struck therefrom and. extended in the plane ofw the base portion and forming a an upright portion lying in a plane at subl stantially right angles to the plane of the base portion, said upright portion having an integral lug struck from the center thereof and extending in the plane of the base portion and forming a seat for the end of the winding for sai pole piece.

7. In oombination,.a tone plate having a raised rim forming a diaphragm seat, a central opening, a magnet system comprising a horse-shoe magnet, posts between the ends of the magnet .and the plate, pole pieces projecting from the ends of the magnet through said opening, a screw for each pole piece passing through the adjacent end of the magnet, through the post and thread,

ed into the plate.

4 8. In combination, a tone plate having a spacing said pole pieces. y L 9. In combination, a tone plate having a raised rim forming a diaphragm seat, a central opening, a magnet system comprising a'horse-shoe magnet, posts betweenthe ends of the magnet and the plate, pole pieces I projecting from the ends `of the' magnet through-said opening, a screw for each pole piece passing through the .adjacent end of.

the magnet, throughv the postv and threaded into the plate, said pole pieces comprising base portions which are clamped fiat against the ends of the magnet and upright portions disposed centrally of. the tone plate, said pole pieces having lugsstruck out of the upright portions and extending towards each other, windings having heads supported by said lugs, said lugs projecting towards each other and forming ali air gap between them of greater extent than the air gap of said pole pieces with their co-operating diaphragm.

10. lin combination, a permanent magnet having pole pieces, said pole pieces having base portions and upright portions, lugs struck out of the upright portions extending in the plane of the base, windings for the upright portions, said windings c-omprisin heads supported upon said base portions an upon said lugs.

11. 1n combination, a permanent magnet having pole pieces, said pole pieces having base portions and upright portions, lugs struct: out oi the upright portions extending in the plane ofthe base, windings for the upright portions, said windings comprising heads supported upon said base pbrtions and upon said lugs, said lugs extending towards each other and forming an auxiliary gap ot greater spacing than the diaphragm gap and substantially less, than the spacing of the pole pieces.

12. ln combination, 'a tone plate comprising` a sheet of relatively vsoft non-magnetie material having a raised rim forming a din aphragm seat, said plate having a central naaaeee aperture, a termlnal block adjacent the aperture, a pair of terminals at the ends of said block, a central screw passin through the block and into the plate, sai plate having lugs struck up from the edgesl of the aperture to engage the ends of the block.

13. lin combination, a permanent magnet,

magnet.

14.1n combination, a permanent magnet, a tone plate having a Acentral aperture, supporting posts between the poles of the magnet and the tone plate, screws passing through the poles and through the posts and secured to the tone plate, a terminal block having a central screw passing through said tone plate between said screws, which supports the magnet.

15. lin combination, a permanent magnet, sott iron pole pieces comprising lat bases and parallel upright portions, and an auf-:iliary air gap formed by striking out lugs from the parallel 11p-right portions.

ln witness whereof, 1 hereunto subscribe my name this 26th day of November, 1924-.

' JAMES A. STIRING.

dii

titl

Gti

Images