US1525709A - Receiver - Google Patents

Description

f s. E. WITT Feb. 10. 1925. l

'RECEIVER 'Filed Jan. 27, 1921 Patented Feb. 10, 1925.

UNITED sfraras tame SAMUEL E. WITT, @F CHAG, EELNIS.

Application 'mea January a?, resi.

My invention relates to receivers and has to do more particularly with receivers ot the so-called loud speaking; type. l

One ot the features ot my invention is the provision of a diaphragm operatively connected to an armature pivotally associated with the receiver electromagnetand with the diaphragm normally flexed preferably b v means of a spring tending to press it toward the pole-piece of the electro-magnet. Thus the diaphragm is under a. normal dexure by means ot the spring with the armature thus held losest to the pole-piece ott the electromagnet. li have 'found that with my improved device the diaphragm is vihrated so as to produce a more natural voice tone, and this is particularly true on the high notes where used for repeating the music as from phonogra phs. The reproduction comes true to pitch throughout the normal range, not a lower pitch as heretofore.

This is brought about, l believe, due to the flexed arrangement or the diaphragm and the cooperating parts, of the'electro magnet connected therewith. The diaphragm is thus held under continuous tension and vibrates truer to the variations in magnetic pull of the electromagnet, than where the'diaphragm is free to partake of a greater amplitude of vibration and thus more tree to vibrate out of tune with the magnetic variations.

lf or a better understanding ot my invention reference is to he had to the accompany-- ing drawing in which" Fig. l is a transverse section through my improved receiver along the. line 1--1 of wie e; i

Fig. 2 is' a bottom view of Fig. l; Fig. 3 is a top or plan view of Fig. l; Fig. l is a transverse section along the lin.; 4-4 0f Fig. 3;

ancnrvnn.. i

rial Le. Mfw.

Fighl' is a perspective view of the armature'faatl a part ot the connector extending:

.to the "diaphragm,

l4`i9;,`l 6 is the mounting: block andspring which act upon the armature and dialid phragm to elef-t a normal tlexure thereof,

and

Fig. 7 is ad'etail view ol the pole-piece. Referring now more in detail to the pre# fel-red lform of my invention as shown herein, it comprises a diaphragm mounting which includes a `front plate 8 having; a

threaded portion 9 to which a horn l0 is threaded. firing" 1l is secured to the 'front 'plate 8 by means of screws 12 in order to clamp the diaphragm 13 between the usual yieldable elements 14 which are preferably small rubber tubes. l also insert a vibration reducing block l5 preferably of glass between the diaphragm and' frontplate 8.

Secured to the ring ll is a` bridgepiecc 'i6 fastened by means 01E/screws as shown by the dot-ted lines in Fig. 1. 'This bridge-piece 16 carries insulated binding posts 17-18 which receive the conductors 19-20 leadingr from the transmitter 21 andbattery 22. Of course, it is to he understood that the device is not limited use in the particular circuit illustrated.

. Connected to the diaphragm 13 is an actuating means in the 'term ci an electromagnet having a circular helix 23 supported upon a core 24 which acts as a continuation oi the heel-piece 25 and is integral with the threaded stud 24". The helix is preferably made up of insulated copper wire, loclcstitched with silk thread, and then pressed over the core, the stitching acting as additional insulation between the helix, and the core and heel-piece. The electromagnet 23 is secured to the mounting plate 26 by means 'of this stud 2li which is inserted through the hole in mounting 26 and into the sleeve 27. Between the sleeve 27 and plate 26 is secured a leat spring 28 in order to firmly hold the mounting 2G and its parts in adjusted position. This `adjustment is effected bythe turning or' the screw 29 which is threaded into the rod 27.

ln order to actuate the diaphragm byA points such as at adjustin adyustablv connected with the diaphragm by means o the. screw eye 31 which passes through the threaded plates 32, 33 placed upon opposite sides of the mica diaphragm and securely clamping the same. This screw-'eye is hooked over a pin end ot the armature 30 at a point beyond the core 24 so that there is a slight amplification of movement of the diaphragm. That is, the diaphragm has a greater amplitude of vibration than the vibration of the armature at the Core. The pivoting endl of the arma- I ture 30 rests upon the 11p-right of the member 25 and ahuts the bracket 34 which is secured to the Lplate 26. This bracket. 34 has a central portion struck back from the upright so that a securing means for thearma-l lure ymay be passed through the small hole 235 and around this struck bark portion, this securing means being in the form of a tine silken cord.

In order to secure a proper cooperation of the electroinagnet and diaphragm I use tension 'means to normally flex the diaphragm and hold the armature, in the form of a ,leaf spring 36 which presses against the armature at a point preferably oppositel edge pivot 41 which engages the tl-shaped groove 42 in the block. New in order to adjust the block and thereby vary the 'tension of the spring 36, the free end of the block carries a screw-eye 43 whichI passes through the plate 26 and is engagedby the thumb-nut 44.` It will thus be seen as the nut 44 is rotated block S7 rotates 4on its pivot and may thus vary the tension of the spring 36 thereby securing the proper horlmal deiiection ofthe diaphragm.

In adjusting the device the armature is connected to the diaphragm by means of the screw eye 3].. Then by means of the adjusting nuls Q9 and 44 the tension of springfhi and adjustment of armature 30 is `varied until the desired air-gap between the arn'iature and core is secured and a suilicient deflection of the diaphragm to secure suitable operation thereof.

It will be noted .that the electroma net, armature and tension spring with its adjustin means are mounted as an adjustable unit', this being' of great advantage in that adjustmentr may be effected at the various or diaphragm without a acting the other nut 44, Vvnut 29 readme parts. 'lhat 1s, the adjustments may be made independently of each other.-

In the use of the device ou a low Voltage such as from about 6 to i) volts.' I have gotten excellent'results with a coil having a resistance of about three ohms with approximately 20() turns of about thirty-two single silk wire. lVheu connected up with the 0rdinaiv local battery transmitter of about ten to twenty ohms resistance excellent loud speaking qualities were secured.

'lhe device has a-lso been particularly useful for loud reprodiu-.tion of phonograplue music wherein a suitable transmitter is placed inside the phonograph horn and then connected to the' receiver as shown in Fig. 1. 0n reproducing the voice on my im.

proved direct current receiver. when connected to the phonograph as referred to, 1t.

produces a more natural voice tone` especially on the high notes. It comes true to pitch throughoiu the entire reproduction, not a lower pitch as heretofore. Heretofore where loud speaking receivers of the perma nent magnet type have been used for phonographic reproduction, so far as I am aware. the reproduction was of a lower pitch so yeo that a tenor sounded more like a, baritone.

This I have overcome by the device shown and. claimed herein.

thus the diaphragm underrgreetest delico-f tion. As soon as the transmitter is operated the resistance of the circuit through the receiver coil is increased so that the diaphragm falls away 'from the electromagnet. Also as the pitch of the actuating tone increases, the transmitter vibrates more and the resistance increases still further thus permitting a further recession of the diaphragm. At this time. of course. it is farthest away from the electromagnet and at a time when thi nest work is expected because the. high no es are being transmitted. Also it is to be noted that as an armature recedes from the pole-pieces of the eleetromagnet, the pull decreases directly with the S uare of the distance. Where no externa tension is brought to bear upon the diaphragm, et the time of transmission of the highest notes andwith the diaphragm furthest from the eleotromagnet, the Weakest actuating current is operatingupon the diaphragm and also at. a time when it is free to partake ana waarna aise of greet volume. holding' true to a grenier range `than I have heen hereiofore able io secure.

l claimi. in a receiver, a diaphragm, an elecf' troniagnei, a normaliy non-polarized armature for the eleotroniagnet rigidly cenneeied te the diaphragrri, and a Spring eating' against ilie armature and mnvahle therewith and normally iexing 'the diaphragm and armature teward the eleetromagnet.

in a receiver, a. diaphragm and meuniingg, and a uniiadjustably mounted relative n:- rlie diaphragm, said unit comprising an elect nagnei; and. non-polarized armature eonneri-ed to ille diephagm and spring aeting; unen the arinaure and ieaing the diaph c i and means ior edyuating the to 1 izhe upon the armature and nei-mai ileaure ef the diaphragm.

:5. in a receiver', a diaphragmand menne ing, a iiridge irrediy secured 'to the diaphragm nannntiep, a unit comprising en electroinagnet an( armature connected to the diaphragnn and single mounting carry ing the eieetromagnet and armature, and nie-.ane 'for adiaetabiy supporting said 'enit mounting upon the 'hridge whereby adjustimeni: of the single mounting will simultaneously adjust the magnet and armature relative te the diaphragm.

ii. ln a receiver, a diaphragm and mounting', a bridge secured to the diaphragm mounting, a unit comprising an eleetromag' nel', and armature eonneeted to the diaphragm and an adjnetahie spring acting up en the armature and dering the diaphragm, for adjustahiy' supporting sai-fi :mit unen said bridge.

in a direct current yreeeiver, a diaphragm, an oleetreinagnet and non-polar ized ainiaiiire connect/ed with the diaphragm nml positioned relative thereto so that the diaphragm and armature vibrate Substantially parallel and the direction ot' motion of the diaphragm and armature coincide, resilient mechanical means acting upon the armature and diaphragm eo as to press the arl'nature toward the pole ieee of the magnet and normally Hex t e diaphragm suilieiently te maintain the am iitude of the operating vibrations of the iaphragrm within the concave formed by the iicxure.

6. In a receiver. a diaphragm, a supporting bridge, a mounting' adjust-ably carried by the bridge piece. an electromagnet, an armature carried hy the mounting, means for operatively connecting the armature to 'the diz'tphragm, and a 'tension spring tending to presa ihe arn'iature toward the electroniagnet adjusfahly carried oy the mounting'.

T. lu a receiver, a diaphragm, an4 electromagnei' and armature i'fperatively Connected to the ,l{ifiphragm. a mounting fier the eleci'ronaifnet and armature, a block pivotally attached ai ene end to the mounting and carrying a. springn ai' the other end for plaeing: icnaien upon the armature, and an adjus'ring' screw .ffonnecied to an intermediate pertion of the hief-ir so as'to move the bloei: io vary the ensioi" of the spring upon the armature.

53. ln a rfgeivcf. a diaphragm, an eleetifoniagnet and armature operatively conneared to the diaphragm, a mounting im' the electrouiagnet and armature, a lever 'pivvw otally attached to the mounting and carry ing' a spring', said spring placing a yieldingr iension upon the armature "whereby the spring' moves with the operating movement@ of the armature, and an adjusting screw conneeied to ihe lever so as to move the lever io vary the tension action of the spring upon the armature.

9. in a dirent current receiver, a dia pliragm, an electromagnet, an armature having' adjustment reiative te the eleetromagnet io vary its' air gap and operatively Connected by a rigid link to the diaphragm, a resilient member for placing tension to give a Substantial normal iiexure to the diaphrag, and means for varying" the tension upon the diaphragm at different air gaps of the eleci'roniag'net and armature.

10. ln a. direct current receiver, a daphragm, an eiectrornagnet, an armature having adjustment relative to the electromagnet to vary ita air grap and operatively connected hy a rigid. link to the diaphragm, a reailient member Een placing tension to frive a Substantial normal iieizure to the diaphragm, means for varying tension upon the diaphragm, and means for varying the air gap for different tensions on `the dia- In witness whereof. I hereuntoeuhserihe my name this 19th day of January, A. D., 1921. y

SAlWUEL E. WiTT.

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