US1815564A - Translating device - Google Patents

Description

July 21, 1931. J. 5. HIGH THANSLATING DEVICE File i June 13, 1929 3 Sheets-Sheet 1 INVENTOR 3/0 19 6. High.

ATT'Q NEY July'2l, 1931. J. 5. HIGH 1 THANSLATING DEVICE Filed June 13, 1929 3 SheetsSheet 2 VINVENTOR Jizrj isni Hjg'h.

ATTORNEY July 21, 1931. J. 5. HIGH I TRANSLA'I'INQ DEVICE Filed June 15, 1929 3 Sheets-Sheet 5 INVENTOR \fi/rjen 5. High.

ATTORNEY Patented July 21, 1931 p UNITED S E PATENT OFFICE JURJEN s. HIGH, o wnxmsnme, PnNNsYLvANIA, AssIGNoR TO WESTINGHOUSE ELECTRIC & MANUFACTURINGCOMPANY, A oonronATIoN or PENNSYLVANIA Q'raANsLArn einEvIoE Application filed. June 13,

My invention relates to devices, such as microphones and loud speakers, for translat ing between electrical energy and. sound energy. V y a i ii i It is an objectofm'y invention to produce a translating devicein whichythe diaphragm shall be provided, throughout its area, with 'means for effecting energy translation. Whenthe device i sa loud speaker, the force exerted by the electro-dynamic. forces 'is exerted at. many points distributed over the diaphragm. Likewise, when the device is acting as a microphone, the diaphragm being moved bythe sound pressure, the resist-, ance to the motion presented by theelectrodynamic'forces is exertedatnumerous points distributed over thediaphragm.

In that form of my invention in which the diaphragm is freeto move as a WllOlQthiS distribution results inia plunger-like movement of the diaphragmg On the other hand, when the diaphragm is restrained along certain lines or at certain'points, the intervening portions vibrate elfeotively, notwithstandingsuch restraint, because of the distributed forces.

his a further object omyinventionto provide a means forproducing flux through thediaphragm overa very considerable area thereof without causing'the inagneticstrum ture tohinder the passageof soundto or from the diaphragm. It is a further object of my inventlon to provide a current-carrying conductor which shallbe the electricalequivalent of twdflat closely adjacent current sheetswithwthei'r currents in opposite directions. i

It is a further object of my invention to sodistribute the magnetic flux thatit shall co 40 operate with substantiallyrthe whole ofeach of said current sheets. i i

I have found. it desirable to space apart the individual pole-members whichcollectively constitute the means fordelivering the 4 flux to cooperatewith: said current sheets. I havelikewise foundit. desirableto space 1 apart the" conductors which -carry the cur.-

rent, heretofore described as current sheets.

It isa further object of my invention toso 0 locate the individual pole-members'that near:

larg'ed scale, partly in section,

posite polarity.

1929. Serial No. 370,526.

lyall of the flux will traverse the plane of the double-current sheetin those parts of the plane occupiedby the conductors and in such direction that the resultant mechanical force will be effective.

It is afurth'er object of my inventionto provide a-means whereby rattling noiseswill be prevented, thereby enabling paper, or other sheet material liable to produce such noises. to serve acceptably as the body of the diaphragm. i

A sheet ofmaterial of only slight stiffness, such as thin paper, can remain ina vertical position without buckling or otherwise collapsing, provided it is supported on each side against tipping or anylarge bending movement. It is another object of this in- .vention'to take advantage of this property of such sheet material.

Details of .thestructure: and further objects of my invention will be readily understood from the following description and the accompanying drawings, in which Figure'l is a perspective view showing the device with parts broken away,

Fig. 2is a rear elevation of the apparatus shown in Fig. 1,

Fig. 3 is a section ontheline IIIIII of Fig.2, j, 3

view of a support on an en- Fig. 5 is a vertical section, on an enlarged scale, through a portion of the diaphragm and the adjacent individual pole-members, and

is aside elevational View of the diaphragm. F i

The device is housed in a casing 1 open at 'the front 2 andback 3. A coil 4 surrounds the central member 5 ofthe magneticcircuit. The windingof the coil lis intended to carry directcurrent, whereby all of the polar uprights 6, at one side of the coil, are of the same polarity, and all of the polar uprights 7, on theother side ofthe coil,are of the op- Blocks or bars 8, preferably of non-magnetic material, space the magnetic circuit away from the floor of thecasing and provide thereby sufiicient room for the coil 4. i y The uprightpole-pieces] are provided with aligned grooves 9traverse to the faces of the pole-pieces 7 which are toward the I pole-pieces 6,:and the pole pieces 6 are traversed by aligned grooves 10 on the faces thereof toward the pole-pieces 7. The grooves 10 are staggered relative to the grooves 9. Individual pole-members '11, of

sufficient length to'extend across the whole collection of pole-pieces 7, grooves 9 with a press fit.

If preferred, the joints betweenthe shelf like individual pole-piecesll and the poleare fitted in the pieces 7 may be welded, the junction being such as to present the smallest possible mag. netic reluctance in the joints.

shelf-like extensions or individual pole Similarly,

the individual pole-pieces 1'2, and the free the'seats of'the several magnetic poles, are

sheet and ribbon, whereby edges of the individual pole pieces, which are in staggered relation, asshown in Fig. 3, and more clearly in: Fig. 5.

The diaphragm is located between the individual"pole-pieces 1 1 and 12'. It con1- prisesa sheet 16 of drawingpaper or other sheet material upon which apribbon 1-7 of aluminum or. other conductive material is wound. The ribbon 1? extends the full length 1 of the sheet 16 and, at'the edge, is folded, as

shown at 18, to extend in the reverse direc tion the full length of the other side of the sheet.

Adjacent to the fold18, the ribbon is cleflected laterally, as shownat 19, and a similar deflection occurs on the other face of the of thetwo deflections,isvsuflicient to locate each length of ribbon upon the reverse side of the sheet, midwaybetweentwo adjacent lengths of ribbon upon the obverse side of thesheet. Thus, the length 22 on the obverse side ofthe sheet, asshown in Fig. 6, is mid way between two lengths 23 upon the reverse sideof the sheet. Preferably, the width of the ribbon is approximately equal to the width of the spaceb'etween each length and the neighboring length on the opposite: face of,

the sheet.- i r V Anydesired way of securing the ribbon to the sheet may be "employed.- Itm'ay be cemerrted; the metal may be forced into the interstices between the fibres of thesheet by pressure; the combined surface of ribbon and sheetmaylbe varnished, or any other way'o-f insuring that the sheet and ribbonwillmove as a unitary structure may be employed.

Preferably, the assemblage,- comprising is subjected to pressure, the paper-is slightly deformed into a zigzagshape, as illustrated at 24 in Fig. 5. As a consequence of this deformation, the successive lengths of ribbon are nearly in one movementamong themselves and are of relatively small density, will serve the purpose. Very soft loose cotton felt may serveJ The silk or other fabric 26 may be supported in placeby beingfolded across the upper edge of the diaphragm, as shown at 30 in Fig. 4. Any other suitable means for 'supportlng the fabric in placemay be used, but the fabric nee'd not be cemented to the faces of the dia phragm.

' In oneform of my invention a part only of the space between the diaphragm: and the ends of theindividual' pole-membersis occup-iedbythe uncompressed volume of the silk.- Theunoccupiedportion of the space between the diaphragm: and the ends-of the'magnetic' structure is intended to be sufficient toaccommodatethe normal movements of the diaphragm; Thesilk will not be compressed b etween the diaphragm and the POlBflDlECe in traordinary excursions of the diaphragm 7 occur. r

In an alternative form, the fabric is made to fill loosely the. space between the chaphragm 15 and the edges of the pole-member's -11 and 12. Motion of the diaphragm in this form is largely restricted to the portions between pole pieces. The upper edge of the diaphragnmtogether with the folded edgeof thesilk, is thrust r between two pieces. of soft felt 31, the upper sheet, as shown, at 20. The combined effect portion of the adjacent faces of which are glued together. The joined pieces of felt may form a frame extending aboutthe whole periphery of the diaphragm or felt maybe 1 used only at certain points, for example, at c the corners thereof. At 32 in Fi'g. 1, several separated portions of the felt are shown and in Fig. 2, the complete frame of felt is illustrated. Atjthe top" of the diaphragm, the felt, by loosely engaging the top plate 33 of the casing, permits transverse displacement of the diaphragm.

At the bottom of'the diaphragm, similar contact between the felt and a plate '34 of brass or other nonmagnetic sheet material permits transverse movement of 1the diaphragm,

The plate-34 supports the diaphragm,

while the ends of-the pole-members prevent 'it from falling by tipping orbuclrling. The top plate83, of the casing, being fastened to. the u-pright pole pieces 6 and 7, takes the thrust set up the magnetic attraction between pole membersll' and 12. l

ran

The diaphragm structure includes, beside tional flux betweenthe] individual polepieces, as indicated in Fig."5.c i

The terminals of the ribbon 17 ,shown extending toward the left'in Fig. 6, are con.- nected to a source of audio frequency cur} rent, in the'case of a loud speakeiy or to deliver the current producedwhen the device is acting as a microphone. c

Inthe loud-speaker act on, current flows in the aluminum ribbon. Considering the moment at which the direction of the current is into the paper in the lower length 23 of the conductor, as illustrated inFig. 5, the

"direction of the current isup from'the paper.

inthe length 22 of the conductor in Fig. 5

i If'the right-handindividual pole pieces in Fig. 5 be regarded as north .poles,the lefthand ones will beregarded. as'south poles. The resulting thrust upon the length 23 of the conductor shown atthe bottom of Fig. 5

willqbe upward andto the right At this moment, the force exerted on theiconductor 22 is downward and to the right. The stifi ness of the diaphragm structure is sufficient .to prevent' the upwardfomponent of the force upon the lower length 23 oftheconductor and the downward component of the force upon the adjacent conductor 22 from producing any result, but thetwocompo 'nents of these twoforcestoward the right 7, cause a movement of the diaphragm in that direction.

upon each length of the conductor will show that, over the whole surface coverediby the winding, thereis, at the moment under consideration, a uniformly distributed force toward the right. This forcegis uniformlydistributed in the sense that it isfequaljover many points systematicallydistributed in a uniform fashion over the area of the diaphragm. It is not meant to assert that the -.force betweentwo adjacentlengthsof conductor is equal to that at the conduct themselves. l I

' In the form of the device in which there is suificient space providedbetween thedia phragm and the pole-members, the diaphragm moves laterally without flexing. It

produces a plunger-like action faithfully representingthe wave-form of the current deliveredto the winding. Any tendency for vibration by flexing, with a consequent rat-.

tling noise, is prevented by iion of the silk.

In the alternative form in the I damping acwhich the edges of the pole-members are close to the silk, latc c c a u "struction will readilyoccurto those skilled A similar examination of the forces acting eral movement of the corresponding parts of the diaphragm is prevented or partially prevented and the diaphragm vibrates in a sysdiaphragm is prevented from interfering with that from the other face by the sidewall. and" top 33 of the casing and the plate .32. Together, these constitute a frame surrounding the diaphragm, which has much 1 the same result as a baffle-board. This frame must not be too will result.

When the device is acting as a microphone, thesound pressure causes the diaphragm to move with a plunger-like motion. Each condeep or a banel-like effect ductor length moves across its respective flux at the same angle and the electromotive forces induced in each add, with the result that theelectromotive force produced at T amount. e e p Both in the loud-speaker action of the dethe terminals of the winding 17 is of a useful vice and in its microphone action, it will be seenthat the sound reaches the diaphragm through openings providedby expanding the metallic structure of the magnetic circuit into alatticework. It will also be seen that, in

I both cases, the movement of the conductors is at an angle approximately45 to the direc-v This is an advantageous angle thatcan be obtained with a flat surface and a distributed pole-piece structure.

Many variations ofthe details of the conin the art. The omission of any specific mention of such variations is not intended as" a limitation. The only intended limitations arefthose required by theprior art and expressed in the claims.

I claim asmy invention:

In a translating device for electri'cand acoustic 'energy,a sheet, a wind ng dlstributed over both faces of said. sheet and iiuX-producthroughout the major partthereof.

uted over both faces of said sheet and means mo located :onboth sides of said sheet for pro- .ducing-pflux through said sheet to cooperate with said winding.

3. In translating device for electric and ing pole-members spaced from one another and the pole-members on one pole-piece being mgimeans cooperating with, said winding acoustic energy, a magnetic circuit compris- 1 ing oppositely located pole-pieces, each pole 1 piece having a plurality of parallel-projectopposite the spaces between the pole-memi in bers on the other pole-piece, whereby the pole.- members are in staggered relation.

acoustic energy, a magnetic circuit comprising a pair of sets of pole-pieces, the sets being located in opposed relation and themembers of each setjbeing spaced apart, an open work of magnetic material extending from one set of pole-pieces toward the other, a similar open Work extending from the other set of pole pieces toward the first, whereby the adjacent extremities of the open work are on opposite sides of an air gap. j V j i 5. In a translating device for electric and acoustic energy,a magnetic circuit comprising a pair of sets of pole-pieces, the .sets

I being l-ocatedinopposed relationand the members of each set being spaced apart, an

' open work of magnetic material extending area COIIIPIlSlIlg an open-Work of magnetic from one set of pole-pieces toward the other', a

similar open work extending from the other. set of pale pieces toward the first, whereby the "adjacent extremities of the open work are on opposite sides of an air gap and the individual pole-members of one open work are opposite the open spaces of the other, whereby the terminals of the magnetic circuit are in staggered relation. 1: 1

6. In a translating device for electric and acoustic energy, a diaphragm anda magnetic circuit includingportions adjacent to said diaphragm on opposite sides thereof, said portions being of lattice work whereby sound may readily pass therethrough. n

7. A structure for conveying flux to an material extending over substantially all of said area and afl'ording passage extending from the exterior of said structure to regions distributed over substantially all of saidarea.

8. In a translating device for electric. and

V acoustic energy, a sheet, a plurality'ofconductors secured on said sheet and meansfor producinga magnetic flux across each of said conductors at an oblique angle to said'sheet.

9. In a translating device for electric and acoustic energy, a plurality of magnetic pole- "members located on opposite sidesofa plane,

a windingv and means for supporting the Winding approximately in said plane. I V

10. In a translating device for electric and acoustic energy, a plurality of magnetic pole--members located in staggered relation on opposite sides. of a plane, those on one side being all of one polarity and those on the other side being all of the oppositepolarlty,

. a winding and means for supporting the winding approximately in said plane; 7 11. In a translating device for electric and acoustic energy, a plurality of magnetic polemembers located in staggered relation on opposite sides of a plane, those on one side being all of one polarity and those on the other side between the clasea proximately in said plane with the individt ual turns thereof approximately midway 4:. translating device for electric and including pole-structures extending over a major portion of the area of the diaphragm on each side thereof and damping material pole-structure and the diaphragm, 1

l3. In a translating device for electric and acoustic energy, a magnetic circuit connecting the sidesof an air gap and a diaphragm netic circuitbeing concentrated and the pole portions being. of open work whereby the;

cross-sectional area eifective to carry the flux carried by the mid portion is distributed at the pole portions over an area approximately that of the diaphragm.

14:. In a translating device for electric and acoustic energy, a diaphragm, means for exertingv force transverse to the diaphragm at places distributed over amajor. part of the area thereof and damping means covering substantially all of said part.

15'. 1111a translatingdevice for electric and acoustic energy, a diaphragm, means forexerting a force transverseto the diaphragm at places distributed over a major part of the area thereof and a connected sheet of material lighter than the material of said diaphragm extending over. substantially all of said part. a

16. In a translating device for electric and acoustic energy, a diaphragm, means for exerting force transverse to the diaphragm at places. distributed over a najorpart. of the area thereof and a connected sheet ofmaterial lighter than the material of said diaphragm extending overisubstantially all of said part andfree tomove relative thereto.

17. In a translating device for electric and acoustic energy, a magnet-1c circult having an air gapin'theform ofa crevice, adiaphragm in said gap supported only at parts thereof extending beyond the and "of sufficient stifi'ness to maintain itself in positionwithin thegap.

. 18. A diaphragm comprising a supporting sheet and a ribbon of conductive material wound flat on both faces of said sheet.

19. A diaphragm comprising a supporting sheet and a ribbon of conductive material wound flat on both faces of said sheet and forming therewith a structure of suificient stiffness .to support itself against buckling when placed in a vertical plane.

. In testimony'whereof, Ihave hereunto subscribed my name this 31st .day of May, 1929.

being allof the opposite polarity, a winding j in said air gap, the mid portion of said mag- 9

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