US1585333A - Telephone - Google Patents

Description

Maw 18'. 1926.

J. MASSOLLE ET AL TELEPHONE Filed larch 26. 1925 3 SheetsSheet 1 n M o k n MM M 3.

i m a May 18 1926. 1,585,333

r J. MASSOLLE El AL TELEPHONE Filed larch 26. 1925 3 Sheets-Sheet 5 vwcmtou 7 9 9114444681. 3%? flttomw Wgi dam, M W

Patented May 18, 1926.

UNITED STATES 1,585,333 PATENT OFFICE.

JOSEPH EASSOLLE, OF BERLIN-GRUNEWALD, HANS VOGT, OF BERLIN-WEMEBSDOM, AND JOSEF EN GL, 0] BERLIN-GRUNEWALD, GERMANY, ASSIGNOBS TO TRI-ERGON, LIMITED, OF ZURICH, SWITZERLAND, A CORPORATION OF SWITZERLAND.

'rnnnrizonn.

Application filed March 26, 1925. Serial 1T0. 18,620.

The invention relates to improvements in telephones and particularly to loud speak ing Or other receiving telephones which are adapted to reproduce sound, such as speech andmusic, with great faithfulness and absence of distortion.

In its preferred form the invention comprises an electrostatic telephone,the invention, however, not being limited to this form.

In our co-pending application, Serial N 0. 518,425, electrostatic telephone, filed November 28, 1921, we have disclosed a tele hone, the diaphragm of which is subdivi ed by annular clamping rings into a plurality of ring shaped portions which are adapted to vibrate independently of each other, these diaphragm portions each having a natural rate of vibration corresponding to some frequency within the acoustic range.

By the provision of a suflicient number of diaphragm annuli each having a different natural rate of vibration, the diaphragm will have resonance peaks correspon ing to various fundamental tones and their overtones, and by the provision of a suitable damping factor, the reasonance peaks thus formed will be flattened so that the vibration of the diaphragm wili correspond quite closely with the various frequencies which are to be reproduced throughout the acoustic ran e.

Tie present invention is in some aspects thereof an improvement upon that disclosed in our said co-pending application. In accordance with the present invention a plurality of diaphragm portions are provided each of which possesses no decided natural rate of vibration as a whole. Each of these diaphragm portions or members resonates to a plurality of .frequencies so that one of these diaphragmmembers or portions may respond to various frequencies within ope range while another diaphra m member or portion responds to various requenoies extending through a different range. This is accomplished by the provision of diaphragm members or portions of irregular shapes,

- and in the preferred form of the invention this is accomplished by subdividing the diaphragm into a plurality of annular portions each of which is of a varying width. Thus the diaphragm may be clamped in position by eccentrically arranged clamping rings so mounted as to provide a plurality of annular diaphragm portions each of which may increase in width progressively through say 180, or generally speaking throughout the arc of some radial angle of the annulus, the diaphragm annulus decreasing progressively in width throughout the remainder ofits angular extent. With such an arrangement the variousdiaphragm portions may be caused to resonate to substantially all frequencies throughout an extended range. In the preferred arrangement, the highest individual natural rate of vibration of one dia hragm annulus or portion will berather c ose to the lowest natural rate of vibration of an adjacent diaphragm portion, it bein thus possible to produce a device in whic there is a fairly uniform variation of the natural rates of vibration of the diaphragm from a very low level to a high level within the acoustic range.

An object of the invention is the provision of improved devices of the character referred to above.

Other objects of the invention comprise the provision of improved devices whereby sound may be reproduced with a minimum of distortion and preferably by a diaphragm, the total area of which is suflicient to render the use of an amplifyin horn unnecessary, when the device is use as a loud speaker for reproducing the sound in an auditorium or the like.

The invention accordingly consists in the improved arrangements and combinations of arts and features of construction all as Wil be more fully describedin the following specification, and as will be particularly pointed out in the appended claims.

In order that the invention may be more thoroughly understood attention is hereby drawn to the accompanying drawings forming part of the invention and illustrating by way of example certain preferred embodiments of the invention.

Referring to .the drawings, Fig. 1 represents a face view of one form of telephone, operated electro-magnetically, and comprised within the invention;

Fig. 2 is a vertical section taken on line 22 of Fig. 1;

Fig. 3 is a face view of a modified form of construction embodyin an electrostatic telephone, certain parts being broken away;

Fig. 4 is a vertical section on line 4-4 of Fig. 3, taken on an enlarged scale;

Fig. 5 is a partial front elevation of a modified form of electro-static telephone; and

Fig. 6 is a section taken on line 66 of clamping ring between which and the sur-.

face of seating flange 3 the edge portion of the diaphragm is clamped by suitable means such as screws 5. The plate 2 is also provided with a forwardly extending boss 6, against which the diaphragm is clamped by suitable means such as a circular plate 7, a screw 8 being illustrated as extendin throu h member 7 and the diaphragm an into t e boss 6.

It will be noted that the center line C of member 7 and boss 6 is spaced somewhat away from the center 0 of the dia hr The ortion of the diaphragm whic is to vi rate is accordingly an annulus of va ing width, bounded at its inner edge by t e riphery of the clam ing member 7, and Edunded at its outer e ge by the inner edge of the clamping ring 4.

In the form. of construction shown in the drawing, electro magnets 99 are indicated, diagrammatically, as being supported by plate 2, in position to actuate the iaphragm 1n res use to varying currents assing throug the electro-magnet circuit. ny desired number of these electro-magnets may be used, the same preferably being spaced at points intermediate the clamping member 7 and the outer clamping ring 4. It should be understood that, if the invention be embodied in an electro-static telephone instead of an electro-magnetic telephone, ca acity surfaces will take the place of the e ectro-' magnets, similar constructions bein described hereipafter in connection wit the following figures of the drawing.

In the construction illustrated in Figs. 1 and 2 the varying width of the vibratory diaphragm annulus causes the same to have di erent natural rates of vibration which vary in accordance with the varying widths of the diaphragm as explained. The diaphragm Wlll accordingly resonate to a plurality of different frequencies throughout a more or less extended range.

Referring next to the form of construction shown in Figs. 3 and 4 of the drawings, a construction 18 shown in which the diaphragm is subdivided into a plurality of annular portions, each of varying width, and each havinga range comprising a plurality of natural rates of vibration. This construction is shown as applied to an electrostatic or condenser type of telephone, which constitutes the preferred form of construction In the construction illustrated, a fixed condenser plate 10 is shown with which co- 0 rate'smovable diaphragm 11. This diap constitutes the movable element of the e ectro-static telephone and in the preferred form of construction the diaphragm is formed of insulating material carrying a coating 12 of electrically conducting material. Preferably the diaphragm is formed of an exceedingly thin disc of mica, which is preferably coated with a suitable conducting metal. The conductive coating may, for example, be a thin silver coat deposited on the diaphragm from a solution comprising silver nitrate and other substances, the invention however, not being limited in this respect. l he sheet of mica used in the dia phragm is preferably of a thickness of only about 3/100 of a millimeter, while the diameter of the diaphragm is preferably quite large, as for example about meter, the invention not, however, being limited to such dimensions. It is noted, however, that mica is particularly well adapted for use in our preferred construction, since a uniform sheet of mica may be obtained, by a splittin process so that it is possible to obtain a s set of athickness as slight as 1/100 of a millimeter, and of a diameter, for example, meter. Such extreme thinness and large diameter are possible because of the high tensile strength of the mica. The advantages of mica for the desired purpose are explained in our co-pending application, Serial No. 518,425, referred to. In our preferred construction the diaphragm is placed under a considerable tension, which may be nearly as great as the elastic limit of the mica, it noted that the elastic limit of mica is exceedingly high in relation to its tensile strength. The mica stands such high tension exceedingly well in practice. It should be noted that the exceed ng thinness of the mica diaphragm makes for lightness and absence of inertia, and it also should be noted that the hard smooth surface of the mica better fits the same for the propagation of sound waves than would a porous or non-uniform surface.

The diaphragm is clamped against suitable seatin surfaces, which preferably are. integral with the fixed plate 10. In the construction illustrated, plate if) is provided with an annular outer rim portion 13, which is concentric with the plate and against which the edge portion of the diaphragm may be seated. In the construction shown the plate 10 is also provided with a boss 14 against which the diaphragm is clamped, this seating portion 14 being eccentrically situated with respect to the plate 10 and with respect to the diaphragm. 7 It will be noted that, in the construction shown, from the center line of boss 14, at 15, is somewhat separated from the center line 16 of plate 10.

A seating ring 17 surrounds boss 14, this ring preferably being concentric with a point, such as point 18, Fig. 3, which is somewhat separated from the centers both of boss 14 and the plate 10 itself. Then the diaphragm is clamped against seating surfaces 14 and 17, an annular vibrating por'- tion will thus be provided between seatin portions 14 and 17, which will be of a widt which varies continuously, first increasing uniformly throughout a portion of its circumference and then uniformly decreasing in width throughout the remainder of its circumference.

Another annular vibrating diaphragm portion is formed between the eccentric ring 17 and an outer seating ring, which, in the present construction, takes the form of a ring 19, which may be concentric with the plate 10 itself. This outer diaphragm portion, bounded by the eccentric ring at its inner edge and the concentric ring at its outer edge, will, therefore, be a diaphragm ortion of ring sha e, generally s eaking,

ut of a varying Wltfill. The space etween ring 19 and the outer edge of the plate 10, in the construction illustrated, is utilized for tensioning and clamping the diaphragm.

The diaphragm is clamped in position by means of a construction which comprises pressure rings or the equivalent, this preferably taking the form of a spider having an outer annular rim 20 and radiating spokes or arms 21. This spider construction is provided with a. boss 22 which is adapted to align with the eccentric boss 14 on plate 10 when the rim 20 of the spider is aligned with the outer edge of plate 10. y The spider is also provided with an eccentric ring 23, which is adapted to align with the eccentric ring 17 on plate 10.. All of the parts described of the spider may be formed, if desired, as an integral metal construction, which may, for example, very readily be cast.

In assembling the plate, diaphragm and clamping member therefor, the dia hragm is positioned against the plate 10 with conductive coating 12 on the side of the'diaphragm away from the late. The spider may then be secured to t e plate by means of screws 24 or other suitable securing devices passing through the rim portionZO of the spider and through the edge portion of the diaphragm and into the rim portion of plate 10. Preferably insulating material 25 is provided about each of the screws 24 to prevent the formation of any creeping paths for electrical currents along the screws from the spider to the fixed plate. The conductive coating 12 on the diaphragm may extend radially only so far, if desired, as the inner edge 26 of the faced clamping portion 20 of the rim of the spider member, or if desired the conductive coating may he continued to the outer periphery of the diaphragm, which may be at the outer edge of the plate, it being noted that the mica body or base of, the diaphragm serves as an insulation between the parts.

The diaphragm may be tensioned by suitable devices such, for example, as peripherally arranged members 27, which may be carried or engaged by screws 28 threaded through suitable openings in rim 20 of the spider member. These pressure devices 27 may be of wedge shape or other suitable shape, and are caused to press against the diaphragm to tension the latter as desired. Plate 10 may be provided with recessed portions 29 in alignment with the pressure devices 27, the diaphra in being pressed into these recesses by mem rs 27 as the tensioning proceeds. Preferably the diaphragm is tensioned up to a point quite close to the elastic limit of the mica, as statedabove.

The fixed plate 10 is provided with capacity surfaces intermediate the clamping or seating portions of the plate, which capacity surfaces are to serve as the fixed plate member of the device with which the adjacent portions of the conductive coating carried by the diaphragm will co-act. As shown, these fixed capacity surfaces may take the form of ring shaped members integral with the body of late 10. These capacity surfaces are re erably rings of varying widths, positione intermediate the clam ing or seating portions of the plate, the ed capacity rings being widest at points at which the corresponding diaphragm annulus has the greatest width and vice versa.

In the construction shown, one fixed capacity annulus 30 is intermediate the boss 14 and the seating ring 17, and an outer capacity annulus 31 is positioned interme- 115 diate rings 17 and 19. As stated, these capacity surfaces are preferably formed of varying widths. Thus the annular surface 30 may be bounded on the inside by a circle 32, the center of which is at a point 32', 120 while the rin 30 is bounded on the outer side by a circfia 33, the center of which is at a different point such, for example, as point 33'. Similarly the outer capacity annulus 31 is of varying width having its inner and 12 outer ed es bounded by circles which are formed a outdifferent points as centers. It will be noted that the construction described gives the capacity surface in each instance a varying width, which may be widest at a 130 point at which the corresponding diaphragm portion is the widest.

The seating rings or portions 14, 17 and 19 and the fixed capacity surface rings 30 and 31 are provided with very accurately faced upper surfaces so that the diaphragm when at rest will be separated from the fixed capacity surfaces by a very small gap, the capacity surfaces being set back from the seating surfaces. This gap, for example, may be a matter of a very few one hundredths of amillimeter. The accurate establishment of this distance, in the construction illustrated is provided by the accuracy with which the seating surfaces and fixed capacity surfaces of plate'lfl" are finished, and variation in the width of the gap between the diaphragm and the fixed capacity surfaces is prevented by the fact that the parts which establish the gap are all formed of metal, having the same co-eiiicient of expansion throughout.

The close adjustment of the diaphragm to the fixed capacity surfaces causes a dam ing of the vibrations of the diaphragm, w hich damping is desired, but not to as great an extent as would be provided by the construction described. Accordingly, the damping effect may be somewhat reduced by the provision of suitable openings through the condenser plate 10 through which the air in the gap between the diaphragm and the fixed capacity surfaces may escape to greater or less extent during the vibration of the diaphragm. In the construction shown the openings for the escape of the air preferably take the form of concentric circular channels ext-ending entirely through the fixed capacity ring portions 30 and 31 of the plate 10= These circular grooves 34, in the case of the inner condenser ring 30, may, for example, be formed about the point 32' as a center. Some of these circular channels will extend entirely through 360, entirely around the fixed capacity portion 30 of the plate, while some of these circular channels 34 will extend through less than 360 of length since they will run out through the outer peripheral surface of ring 30, with which t ey are eccentric. The circular channels 34', formed through the outer capacity ring 31, are similar. The rings of metal intermediate the circular channels 34 and 34' are, of course, held together by suitable connecting portions of the metal which may bridge across the various circular channels at points which may, for example, be out of alignment with each other.

In the construction described, the vibrating diaphragm portion intermediate the seating portions 17 and 18 of the plate will have various individual rates of vibration extending through one range of acoustic frequencies, while the outer diaphragm annulus between seating rings 17 and 19 will have various other natural individual frequencies extending through a different range of the acoustic frequencies. The outer diaphragm annulus as arranged will have a, hi her range of frequencies than the inner diap ragm annulus and the arrangement preferably is such that the lowest natural frequency of the outer annulus is nearly the same as the highest natural rate of the inner annulus. This equalit of the lowest natural rate of the outer diaphragm portion with the highest natural rate of the next adjacent inner diaphragm portion may be arranged by making the least width of the inner diaphragm annulus substantially equal to the greatest width of the outer diaphragm annulus.

\Vith such an arrangement as many eccentric diaphragm rings may be arranged one with another-as is required, so that the range of natural vibration of the diaphragm may extend substantially from the lowest up to the highest acoustic fre uencies which will have to be reproduced. 11 case such an arrangement requires a telephone having too great a total diameter, a plurality of such telephones may be used, and this is in fact the preferred arrangement.

In the construction as illustrated, the highest frequency of one diaphragm portion may, as stated, be substantially equal to the lowest natural frequency of the adjacent diaphragm annulus. This is evidenced by substantial equality of the smallest width of the inner diaphragm annulus, indicated at with the greatest width of the outer diaphragm annulus, indicated at d the reference characters d, d, d and (1 being used to indicate the respective widths of the dia phragm portions from the bottom to the top of the diaphragm along the central Vertical axis, referring to Fig. 3. With this arrangement,however, an absolutely uniform variation of the natural rates of vibration of the entire diaphragm is not produced. Uniform variation throughout the entire diaphragm is possible when the widths of one diaphragm portion overlap the widths of the adjacent portion to the extent of 90 of angular displacement, and such an arrangement may readily be accomplished within the present invention. This arrangement may be used when two or more telephones are used in place of a single one because of the fact that one telephone would be too large, as stated above. In this case the several telephones may have their widths of vibratory diaphragm portions displaced to the extent of 90 with reference to one another.

To make the above matter of overlapping widths somewhat clearer, it should he noted that each diaphragm annulus increases progressively in width from its greatest width, as at d, to its least width, at (11', where d and d are illustrated as being on the vertior the positions?! best distribution; of resonance frequencies, therefore, the least width, d,"()f, theifinr annulus should approximately equal, not the greatest widthE d, of the. outer annulus, but the width 0 theiouter annulus ata point intermediate d and d, in which case width d would of a course be less than width d of the enter in. proper.

annulus aligned therewith, and greater than width d.

, The'diaphr'agm rings may and preferably rcisc calculated that approximately equally large surfaces are operative at all f uencies whereby all frequencies are repro uced ropcrtio'n one to another.

d. orm'o'f construction is shown h p I h In ({his case the (ii;- pm 11 a,' acon uctivecoatin is 'sec u i ed'iii po s i tl on between the fix con denser plate and a spider member. The diaphragrn is shown as clam outer peri 'hery, by devices w ich are con centric wit .the diaphragm itself, andabout 7, one inner circle which is eccentric with the d about its diaphragm so as to produce a single vibratory diaphragm annulus of varying width,

In the construction illustrate the plate 10 has a ring portion which is secured-to an outerfianged ring 36 by means, forexample,-of-screws 37 extending through a peripheral flange of rim 35' and into ring 36, insulating material 38 referably being used about screws 37 and tweenthe adjacent faces of rim 35 and ring 36. The clamping or pressure applying member compr ses an outer concentric rim portion 39, together with radial arms 40. An eccentric ring 41 is carried by the arms 40. Clamping and pressure applying members 42 extend through this ring and are adaptedto press the adjacent portion of the diaphragm against correspondingly ositioned seats 43, formed in the fixed con enser member 10'.

The ring 36 to which the fixed plate 10 is secured is fastened to the rim 39 of the spider member by means, for example, of screws 44 which extend peripherally around the device. The diaphragm is secured under tension at its outer ed e by means of clamping and tensionin evlces 45, 45', which extend through t e rim 39 of the spider member in two concentric rows one within the other.

These clamping members may comprise small wedge shaped blocks 46, 46, seated in suitable openings in the rim 39 and hearing against the adjacent surfaces of the diaphragm. These pressure applying members bear with line contact against the diuphragm and may be forced more or loss :bers 46 and 46'.

tightly agains't"* "ijh diaphragm by the small screws 45, 45'. Suitable recesses '47, 47' are provided in the face of ring 36 and rim.

35 of thefixed late construction respective- Z-iigwhhh t e adjacent portions ofthe 'aphragm be pressed whenthe clamp-'- members are tightened. Screws 42, ex-

tending through theeccentric ring 41, are similar I mu dw Operate P s pp ying members 48, which are similar to memlithe plate 10' is provided with-a fixed capacity surface 49 which extends in the form of a of varying width around the de--.

intermediate the circles alon -which t he diaphragmis clamped at 48- an '46. This annular capacity surface is only'illustrated 1nart,,since it will be understood that its wi th may vary thrcughout its an ar ex tent in the sanie'manneras was exp ained in 35 connection with Fig. 3 Air in the gap between. the fixed capacity surface and the diaphragm may be relieved bythe provision of channels 50 which may be formed in a similar manner to the channels '34, described in connection withFigs. 3 and 4. The capacity surface 49 is set back sligh liy from the seating surfaces on vwhich the iaphragm will be clamped, adjacent the recesses 43 and 47 so as to est blish a slight up between the fixed capacit surface and t e diaphra m as was explained in connection with the construction shown in Figs. 3 and 4. The construction maybe completed by a cover. late 51 which may be secured to the rim ange 36 of the plate construction by means ofscrews 52 so as to cover i over t e plate construction together with the screws 37 and 44. p ,j

In the construction described, the diaphragm is both clampedand placed under e desireditension by suitable adjustment of the pressure devices 48, 46 and 46, no screws or other devices assing th'rou h the diaphragm itself. It will, of course, e understoo that similar clam ing and tensioning means may beused ii desired, in connection with the form 0 construction shown in Figs. 3 and 4. The fixed plate memberz aii t 10' me if desired, be constructed in the form 0 a spider instead of in the form of a solid plate, in which case the member 10' will comprise the rim 35 connected to the hub 53 by means of radial arms which carry the fixed capacity surface rings 49.

It will be understood that electrical connections are to be suitably made to the fixed and movable members of the condenser telephone. Thus in the form shown in Figs.

3 and 4 one connection is of course, made to the plate 10 and the other connection to a suite is point such as the rim 20 of the spider, which, of course, is in contact with t is conductive coating 12 of the diaphragm.

In the'form shown in Figs. 5 and 6 suitable connection may member 10 and with the rim39 of the spider construction.

The device, as described, in its various forms, particularly in the forms illustrating the same, as an electrostatic telephone, is particularly well adapted for use as a loud speaker or sound reproducer, which may be employed, for example, to reproduce sound in theaters or concert. halls or the like. When soused, sufiiciently loud reproduction may be given without the use of any amplifying horns or the like, whereby the errors of re roduction due to such devices are obviate and this is obviously true because of the considerable size of the diaphragm which is preferably employed and'by the employment of two or more similar devices if necessary, as described above. In this connection it will, of course, be understood that the electrical currents operating the, device may be suitably amplified as by means of the usual vacuum tube amplifiers, so that the diaphragm portions may be given a sufficient amplitude of vibration in case loud re roduction is desired, It will also be noted that the device, because of its large -number of natural rates of vibration, provides for vibration of the diaphragm in resonance with a considerable number of acoustic fre uencies which are to be reproduced w ereby resonance peaks are formed throu bout the entire range 'of frequencies whic are to be reproduced. Dis tortion in reproduction is, however, prevented by the dampin eflect provided, so that the resonance pea s will be flattened. Accordingly, in a graph or characteristic curve portrayin the operation of the diaphragm at all equencies reproduced, the tops of the resonance peaks will be connected together by a smooth curve which is substantiall the same as that which would represent t e correct vibration of the diaphragm for the various frequencies if the diaphragm had no natural rates of vibration at all. That is to say, we consider it im ractical to so arrange such a large diap ragm as we prefer to use, that the natural rate of vibration of the same will be outside the acoutic range; and, accordingly, we provide for as large a number of natural rates of vibration within the acoustic range as is possible and obtain the effects described.

It should be understood that the invention is not limited to the exact details of the construction which have been particularly de scribed, but thatthe same is considered to be of a considerable breadth as is indicated by the scope of the appended claims.

What I claim is: I 1. In a telephone,'thc combination of a diaphragm, a plate, and means for clamping g the diaphragm to the plate, in spar-ed relabe made with the plate tion thereto, comprising rings eccentric to the diaphragm to provide vibratory diaphragm portions having difierent natural rates of vibration.

2. In a telephone, the combination of a di'aphragm,a plate,- and means for clampmg the diaphragm immovably to the plate, about the periphery of the diaphragm and at a pomt eccentric with respect to the diaphragm, so as to provide a complete annuar diaphragm portion of varyin width spaced from said plate and surroun ing said oint.

' 3. In a telephone, the combination of 9. diaphra a plate, and means for clamping the iaphragm to the plate, about the periphery of the diaphragm and about a cir cle eccentric with respect tothediaphragm and intermediate the center and periphery thereof, so as to provide a vibratory diaphragm portion extending completely around said circle.

4. In a telephone, the combination of a diaphragm a plate, and means for so clamping t e diaphragm to the late as to provide a plurality of complete ring sha ed diaphragm portions, eccentric to the dia' hragm, of varying widths and having diferent natural rates of vibration.

5. In a telephone, the combination of a diaphragm, a member to which the same is secured, and means for so clamping the diaphragm immovably to said member as to provide a vibratory diaphra un portion in the shape of a complete annulus of a width uniformly increasing throughout a portion of the angular extent of the annulus, and uniformly decreasing throughout the remainder of the angular extent of the annulus.

6. In a telephone, the combination of a diaphragm, a member to which the same is secured, and means for so clampin the diaphragm immovably to said mem er as to provide a vibratory diaphra m portion in the shape of a complete annulus of varying width, whereby the diaphragm will have a plurality of different natural rates of vibration throughout its area.

7. In a telephone, the combination of a diaphragm, a member to which the same is secured, and means for so clamping the diaphragm to said member as to provide a pair of separately-vibratory diaphragm portions, each in the shape of an annulus of varying width, one surrounding the other, each annulus having a plurality of different natural rates of vibration, the rates of vibration to which one annulus responds lying within one range, and the rates of vibration to which t e s annulus responds lying within a differ. t range.

In telephone, the combination of a diaphragm, a member to which the same is SGCUi'mi, and means for so clamping the diaphragmto said memberes to provide a plura lit'y separately-vibratory diaphragm portions, each inthe shape of an annulus of varyingwidthfsaid annuli being radially one witliin' the other, each annulus having a range or frequencies to which it resonates, the lowest natural frequency of one annulus being close to the" highest natural frequency of the adjacent annulus on one side thereof. 9.'In"a telephone, the combination of a diaphragm,-a fixed condenser plate having a seating surface and a capacity surface, and means for clamping said diaphragm agams't said seating surface so as to provide a vibrator annular diaphragm portion of varying wi th separated from said capacity surface by a slightga 10.11; a tefdphonathe combinatlon of a diaphragm hiav' v portion of annu ar shape with varying width, anannular capacity surface separated from said diaphragm by a slight gap, and means for securing said parts in position, with said dia hragm under tension. l1. In a te ephone,.the combination of a diaphragm of irregular shape, calculated to resonate locall' to various frequencies, a plate closel a jacent to said diaphragm to produce a clamping effect, said plate'having openings therethrough to somewhat relieve the damping effect, and means for securing said parts in position with said diaphragm under tension.

12.11111 telephone, the combination of a diaphragm of irregular shape, calculated to resonate locally to various frequencies, said diaphragm being of insulating material with a conductive coating, a condenser plate closely adjacent to the insulated side of said diaphragm, and means for securing said parts in ,position.

13. In a telephone, the combinationoi a diaphragm having a plurality of separated parts each having a plurality of different natural rates of vibration, supporting means, and means for securing sald diaphragm thereto, under tension, and for separat ng the parts of said diaphragm.

14. In a telephone, the combination of a diaphragm, a member to which the same is secured, and means for so clamping the diaphragnrto said member as to provide, a pair of separately-vibratory diaphragm portions. each in the shape of an annulus of rnrving width. one surrounding the other, each annulus having a plurality of different natural rates of vibration, the rates of vilwnlion to which one annulus responds lying iihin one range, and the rates of vibration which the second annulus responds lying v'lihin a diil cnt range, the outer annulus rsponding to n higher range of frequencies than the inncr,

15. In a lclrphone, the combination of diaphragm means, comprising :1 plurality of securing sai diaphragm means,

vsulating materia an eifective vibratory 'tances therefrom,

annuli of one radially wi f'n the other; porting means, and meagi' s or 'i'p i 's, o of difl'erent natm al. rates of vibration, the rangeof frequenciesof one annulus being 'difi'erentfrom the range of another,

16. In a .-telephone, the combinationof comprising a plurality of portions of irregular shape, supporting means, and means for securing said portions thereto about all their edges.

17. In a telephone, the combination of diaphragm means, comprising ,a plurality of portionsof irre lar shape, formed of inand having aconducting coating thereon, a fixed condenser plate, and means for securin said portions in position spaced a sli ht istance from said plate, with the con uctive coatings on the op "osite side from said plate, said coatings eing connected together electrically.

. 18. In a-telephone, the combination of diaphragm means, comprising a plurality of portions of irregular shape, formed of insulating material and having a conducting coating thereon, each portion being adapted to resonate in a difierent range of he quencies, capacity surfaces spaced slight distances .from the insulated sides of said portions, and means for securing said parts in position and for electrically connecting together said capacity surfaces, and said diaphragm means portions.

19. In anelectrostatic telephone, the combination 'ofmovable plate means, compris-r mg a plurality of irregularly shaped diaphragm portions, each portion being adapt ed to resonate .to a different range of fr e quencies, capacity surfaces spaced slight disand means for securing said parts in position and for electrically connecting together said capacity surfaces, and the portions of said movable plate means.

20. In an electrostatic telephone, the combination of diaphragm means, com rising a plurality of annuli of varying w dth, lone surrounding the other, fixed means providing capacity surfaces, each comprising an annulus of varying width, spaced slight distances from said diaphragm annuli, and means for securing said means in position.

21. In an electrostatic telephone, the combination of diaphragm'means, comprising a plurality of annuli of varying width, one surrounding the other, fixed means providi'n, capacity surfaces. each comprising an annulus of varying width, spaced slight distanccs from said diaphragm annuli, and means for securing said means in position, said fixed means having circular openings extending therethrongh from said capacity surfaces.

22. In an electrostatic telephone, the comannuli theretd aboiit their peeach annulus having faplurality binafion of a fixed condenser plate having" means ciii ried By said spider construction for-clamping said diegh'ragm against said 10 seatmg surfaces with t e diaphragm spaced slightly from said cepscity surface.

JOSEF ENGL. JOSEPH MASSOLLE. HANS VOGT.

bination of a fixed condenser plate having an annular capacity surface and annular seatin surfaces at the outer and inner sides of sai capacity surface, a diaphragm comslightly from said capacity surface. 5 prising a movable condenser element, and V diaphragm-securing means. comprising a spider construction having a rim portion adapted to be secured to said fixed plate, and

J OSEF ENGL. JOSEPH MASSOLLE. HANS VOGT.

Certificate of Correction.

It. is hereby certified that in Letters Patent No. 1,585 333, granted May 18, 1926', u I n the apphoation of Joseph Massolle of Berlinrunewald, Hans Vogt, of

erhn-Wflrnersdorf, and Josef Eng}, of liverlin-Grunewald, Germany, for an improrelnent m Telephones, errors appear in the printed specification requiring correction as follows: Page 3, line 7, strike outthe word from page 6, line 82, claim 3, after the word about insert thelword's the periphery of; and that. the said Letters Patent should be read with these mrrections therein that the same may conform to the record of the casein the Patent ()flice..

Signed and sealed this 22d day of June, A. D. 1926.

[emu] M.J. MOORE,

Acting fi'mmmaaw' Mr of Patents.

means carried by said spider construction for clamping said diaphragm against said 10 seating surfaces with the diaphragm spaced Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,585 333, granted May 18, 1926, upon the'apphcation of Joseph Massolle of Berlin runewald, Hans Vogt, of Ber '-W ihnersdorf, and Josef Eng], of verlin-Grunewald, Germany, for an improvement in Telephones, errors appear in the printed specification requiring corrction as follows: Page 3, line 7, strike out-the; word from page 6, line 82, claim 3, after the word about insert the lwo'rd's tire periphery of; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the cast? in the Patent Oflice..

Signed and sealed this 22d day of June, A. D. 1926.

[SEAL] M.'J. MOORE,

Acting Umnmdsxioner of Patents.

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