US1352597A

US1352597A - Receiver

Info

Publication number: US1352597A
Application number: US259365A
Authority: US
Inventors: Henry C Harrison
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1918-10-23
Filing date: 1918-10-23
Publication date: 1920-09-14
Anticipated expiration: 1937-09-14

Description

'Unirse STATES PATENT, OFFICE.

HENRY C. HARRISON, OF NE'W YORK, N. Y., ASSIGNOR TU VESTERN ELECTRIC GGMPANY, INCORPORATED, 0F YORK.

NEW' YORK, N. Y., A CORPRATION OF 'NEW RECEIV ER.

Application filed October 23, 1918.

To all wfiomz't may concern.' A

Be it known that l, HHNRY (l. Hannisou. a.- citizen of' the United States, residing at New York, in. the `county oi N ew York, State ot"k New York, have invented certain new and useful llnproveinents in Receivers. of which the following a full, clear, conoise, and'exact description.

This invention relates to telephone .rev ceivers'for `general use in telephone or signailing circuits and has for its object Yto provide a receiver with an improved magnetic structure and one having its parts so' pro-- portioned and arranged as to provide aninstruinent of high sensitivity in responding to the feeble alternating currents such as' those vgenerated hy voice waves impinging.

npon the diaphragm of a telephone transvv'mitten vMore specifically, the object of this invention is to provide a telephone receiver having its magnetic structure so arranged as to provide a path of low reluctance for the flux nenerated bythe alternatingv or voice currents and therefore capable of operating' elliciently and without causing undue distortion in the voice current wave forros.

To attain this object, the invention consists oi? certain new and novel features in the construction as will he more fully described and particularly,pointed out in the appended claims.

ln the accoinpanying;r drawings. Figure 1 is an enlarged view in perspective oi' the magnetic structure of the receiver embodying' this` invention: Fig. 2 is an inverted plan view pai-tl)y in section of the receiver shown in lfig. 1; and Fig. fis a diagrammatic View of the inagrnetie circuit of receiver shown in Fig. 1.

lietcrringI now to the drawing, there is shown the magneti(- ol the customary wateh-case tjvpe. The permanent magnet 5 which is semi-circular in shape is provided at its ends with inwardly and upwardly etei'nlingY polar extensions 6 and i which are secured in place hv means ol' the screws 898. rl'he iree ends ofjmemhers 6 and 7 are triton-.ated to provide two sets ol" pole pieces 9. 'l0 and ll. and l2. 'i3 and 14. The outer pole pieces il. ll. IQ and 'lflare lient outwardl)7 and i'ormed to lie in a. circle. rPhe inner pole pieces l() and 13 are heut inwardlv and provided with enero'izing ywindings iii and lli. respectively.

Specification of Letters Patent.

.Securely fastened to circuits.

structure oi ay receiver "Patented sept. 14., 1920. serial No. 259,365.

the receiver diaphragm 17 a cup-shaped magnetic member 18, the wall 19 of which lies outside of the polepieces l0 and 13 but inside of the pole pieces 9, 11, 12 and 14. The 'talking windings 15 and 16 are connected in series and in such a manner that current iowing through the windings in a given direction will ineke the

o oles

10 and 13 of opposite polarity. This' is represented in Figi-lof the drawingji1 by marking pole 10A with a H9 sign4 and pole 13 with a sign as showing the direction of flux at a given instant resultingr from voice currents traversing the windings in the direction indicated by the small arrows.

With current Flowing through the windings in the direction as designated, the operation of the receiver will he leasily un# derstood by an examination of the magnetic The main path for the. polarizing flux is from pole l() across the air-gap to cup memberlS, thence across the air-gap'to pole piece 13 and back to pole 10 through polar extension 7, magnet 5 and polar extension 6. Parallel paths are also provided trompoles 9 and 1l to the Wall portion 19 and from the wall portion 19 to poles 12 and 14.. Since the direction of flux across ,the air-gaps in these paths is radial there is no force exerted tending1 to cause movement ot' the' receiver diaphragm. l

The paths tor the ythis generated by voice currents flowingu through the talkingq windings 15 and 1G with the direction of current as'indicated are as follows: V 'd (1) From pole 1.0 across the air `gap tocopmeinher 18. to wall portion 19, thence across the air-,gaps in and hack to pole 10.

(2) From pole piece 13 to polepieces 12 and- 14, thence across the air-zaps in parallel to the wall portion 19. cup-member 18 and across the air-gap to pole. 13.

(E) From pole piece 10 across the airgap to cup-member '18, across the air-grap to pole 13, through polar extension?, perinanent inagi'iet 5 and polar .extension 6baclr to pole l0. I

The reluctance of the. latter path, however, is so high to alternating currents of voice frequencv that the flux will tend tov leak across hetween the polar extensions rather than to pass through the permanent magnet. With the above paths for the p olarizing' flux resulting" from the permanent fis parallel to poles 9 and 1l magnet and the alternating Hux generated by the voice currents at a given instant, it

will be noted that the flux from the talking winding is in a direction toaugment the polarizing flux passing from pole 10 to cupmember 18 and from the cup-member to pole 13, thus increasing the pull on the diaphragm 17. The" flux from the talking winding passing from the wall portion 19 otl ciip-member 18 to poles 12 and 14 wall portion 19 is in :tore does not affect the pull on the diaphragm. With the current flowing through the talking windings in the opposite direction, the flux from the talking windings is in a direction to oppose the polarizing flux passing across the air-gaps from the pole 10 to the cup-member 18 and from thel cup-member to pole 13. The flux from the talking windings passing from poles 9 and 11 to the wall portion 19, to cup-member 18 and from the wall portion 19 to poles 12 and 1-1 is in a radial direction as in the revious case, and, therefore, does not a ect the pull on the diaphragm 17.

The outer poles 9, 11, 12 and 1-1 in combination with the wall portion 19 of` cup- "memberq18, provide low reluctance return .paths for the alternating currents.

Because of the relatively large air-gaps existing between poles 9, '11, 12- and 111, and the diaphragm 17, the latter, if of magnetic material is not affected appreciably by Pflux passing through these poles. However, in this design it is not essential that the diaphragm itself be of magnetic material, since the cup-member can be proportioned to satisfactorily carry the flux generated. Because of the low reluctance paths provided for the alternating current flux generated by the voice currents the magnetic struc-.

ture embodying this invention provides a receiver of high sensitiveness. A further advantage o'the low reluctance return paths for the alternate current iiux isthe .lesser tendency for the receiver to be demagnetized.

What is claimed is: 1. Atelephone receiver comprising a per manent magnet, a pair of triturcated polar extensions secured to the ends thereof, a. magnetizing winding for each of said polar extensions, anda diaphragm in operative relation with the 'middle trifurcations of saidv polarextensions, but so disposed with respect to the outer trifurcations of said polar extensions -as not to be eii'ect'ed by inagnetic flux passing therethrough. d

2. A telephone receiver comprising a permanent magnet, a polar extension secured to the magnet at each end. the free end of each polar extension being formed to pro vide three pole pieces. a maguetizing winding on the middle pole piece of each extension, and a diaphragm in operative relation a radial direction and there` with said middle pole pieces but so .disposed with respect to said other pole pieces as not to be affected by magnetic flux passing therethrough.

3. A telephone receiver comprising a permanent magnet, a pair of inwardly extending polar extensions secured thereto," lthe free end of each polar extension being formed to provide three pole pieces, a magnetizing winding on the middle pole piece of each extension, said windings being connected inhseries, and a diaphragm in operative relation with the middle pole piecesof said polar extensions, but so disposed with respect to said other pole pieces as not to be aifected by magnetic flux passing therethrough.

4. A telephone receiver comprising a permanent magnet, a trifureated polar extension so formedfas to provide three pole pieces secured to each end of said magnet, the middle pole piece of each extension being Jformed to lie inside of the outer pole pieces, a diaphragm, and a magnetic cupshaped member secured to the diaphragm and in operative relation with said pole pieces. u

5. A telephone receiver comprising a semi-circular permanent magnet, a polar extension secured to each end of the magnet, the free end of each of said polar extensions being formed to provide three pole pieces out of line with each other, a magnetizing windingsecured on the middle pole piece of Y establishing a. constant magnetic potential between said polar extensions, means for establishing varying magnetic potentials between said polar extensions, yand a diaphragm in operative relation to the middle trifurcations of said polar extensions, but so v disposed as not to be affected by the magnetic flux passing through the outer trifurcations of the polar extensions.

7. A telephone receiver comprising a plurality of pole pieces having a magnetizing winding thereon, a diaphragm in operative relation to said pole pieces, means for impressing a constant magnetomotive force on said pole pieces. means for impressing a variable magnetomotive `force on said pole pieces` and a plurality ot' additional pole pieces adapted to provide ,return paths for the flux generated by said magnetizing windings and so disposed." as to exert no pull upon said diaphragm.

8. A telephone receiver comprising a plu-- rality of pole pieces having a magnetizing Winding thereon, s diaphragm having a variable inagnetomotive force on said pole pieces, :ind n plurality ci' additional pole' pieces adapted to provide return paths for the tlizx generated by said megnetixing windings but so disposed :is to exert no puii upon sziid diaphragm.

9. telephone receiver comprising relitji7 of pole pieces having :i rnngnetizing winding thereon, means for impressing e constant magnetomotive'forciy on seid pole pieces, means for impressing :i variable magnetomotive force on said pole pieces, a plurality of additional pole pieces adapted to provide return paths forthe flux gene :i pilirated by said magnetizing windings u dia- 4 phrzigm, and a magnetic cup-shape member attached to the diaphragm, said cupsho-ped member including a Well portion extending between said .first pole pieces and said Second pole pieces.

l0. A telephone receiver comprising a plurniity oi' pole pieces having a magnetizing winding thereon, means for impressing a constant nnignetoniotivc torce on said pole pieces, menns'for impressing u variable magnetomotive force on seid pole pieces, rality of additional provide return paths :i plupole pieces adapted to for the ux generated by said mzignetizing windings, :i diuph mgm,

and, magnetic cup-shaped member atL taehed to the diaphragm, said cup-shaped member being provided with rightengle portions extending between said first pole pieces and said second-pole pieces to provide e return path for alternating current flux in a direction which does not exert any pull upon the diaphragm,

In Witness whereof I hereunto subscribe my name this 18th day of October. AqD; l

HENRY C. HARRISON.