USRE22658E - Bone conduction audifhone - Google Patents

Description

Aug. 7, 1945. H. KOCH v BONE CONDUCTION AUDI PHONE Original Filed Aug. 51, 1935 IIIEI I 'IIIII Ill lirrnllu PIC-5.6

INVENTOR:

HENRY KOCH, 1 nd I MY AM ATTORNEYS Relates A 1, 1945 1 UNITED STATES PATENT ori ice sons CONDUCTION anmrnom: Henry Koch, Jamaica, N. Y., aasignor to Dictagraph Products Company, a corporation of Delaware lnc., New York, N. Y.,

Original No. 2,144,458, dated January 1'1, 1939, Se-

rial'No. 38,882, August 31, 1935. Application'for reissue January 18, 1940, Serial No. 314,564

9Claims. (curs-107) I Thi inventionrelates to ,audiphones and has particular reference to audiphone receivers having a vibrating element adapted to be placed in operative connection with the bone structure of the user for transmitting audible,- sounds picked up by a suitable microphone to the inner car through the bone structure.

In copending application Serial No. 678,13 filed June 29, 1933, now Patent No. 2,148,024, there disclosed a bone conducticn receiver which is characteristic in that the electromagnetic means of the receiver is supported by the tympanum or reed, so that, in response to energizationby voice currents, the inertia of the electromagnetic ineans causes it to in direct remain stationary while .the tympanum or reed vibrates relatively thereto. The casing of thereceiver is securedtmthetympanum or reed'and consequently vibrates over its entire surface, so that any portion thereof may be supported by a head-band or other holder in operative connection with the bone structure of the user, such as on the mastoid'eminence, for transmitting its vibrations ther'ethrough.

-This device has proven reasonably satisfactory. but because the surface area of the casing-wall which, engages the bone is relatively large, a

considerable amount of power is required to pro-- duce sumciently strong vibrations to enable the r-to hear well. .In this respect the so-called button type of bone conduction receiver, in which a button carried by the, tympanum or reed engages the bonestructure, has certain advantages, because the area or contact of the button is relatively small and its vibrations are concentrated and it is not necessary to vibrate the headband, I

with the result that less poweris required'to operate the.receiver.- However, the button type ofbone receiver as heretofore constructed is not practicable, because the pressure'which must be applied to the electromagnetic means inv order to secure firrncontact between the button and the bone causes the vibrations of the tympanum or reedjo be suppressed and sometimes closing of the magnetic gap.

In accordance with one form of.the present invention, a bone conduction'receiver is provided in which the advantagesofthe button type receiver, in so far as concentrated'vibration and reduced power-consumption are concerned, are combined with the advantages of the reaction or inertia type bone receiver. in so far as practicability and operating effectiveness are concerned.

.The aforementioned form of the invention has several modifications, one of which comprises 1m electromagnetic means-supported by its tympanum or reed the face plate of a casing adapted to be supported'by a headband or the like in position for operative connection with the bone structure of the user, and having a button extendin through the face plate and connected to the electromagnetic means so that the receiver casing, due to the inertia of the electromagnetic means, vibrates as a unit and at the same time the button concentrates a portion of the vibrations. In this way, the face plate engages a relatively'larse area of 'the bone and the button engages a relatively small area of the bone, and the instrument combines the advantages of the button and inertia or reaction type of bone receiver without having the disadvantages of these two types of devices. The electromagnetic means I is preferably of the cantilever type with the button located adjacent the fulcrum, to produce powerful button vibrations of small amplitude.

Another modification of the invention comprises a casing supported by a headband or other holder and having the electromagnetic means secured thereto in such a way that the tympanum or reed vibrates freely therein without producing a reaction sufliclent to materially vibrate the casing, because the inertia of the reed is relatively low. Secured to this tympanum or reed is a button projecting through the face plate of the casing for operative connectlonwith the bone structure oi'the user, the tympanum or reed being still and substantially unaffected by any pressure whlch'is applied to the button by contact between it and the bone structure of the user. In this form, the so-called button effect predommates, as compared to the inertia or reaction effect.

In another form or the invention, the electromagnetic means is. secured to the casing, which is supported by the headband, while the contactor, adapted to operatively engage the bone structure of the user, is secured to the tympanum or reed, so that the reaction eiiect'is relatively small because the inertia oi the tympanum or reed is low compared to that of the electromag- This form of the invention is, in

netic means, effect. a button type receiver in which'the contactor buttonmayconstitute a small part of the I face plate area or may have a large area, such as a large prop rtion or all of the area of the face plate. In that respect,-the' device is similar in app arance to the inertia reaction type of receiver, but differs in operation therefrom, since ms whole casing- -is not vibrated andhence it is not necessary to vibrate the headband. Resilient means is preferably inter-posed between the easness of the vibration thereof.

It will be seen that with the several forms of this invention-the advantages of the button and N ing drawing, in which:

fried by two filamentary conductors 2| to ltricaliy connectedby spring the corresponding V ico'rd l1 inserted in openings 32 of the casing IQ.

out of tbe'barmagnet iusted position-by means'oflock nut 24.

whereby contact between the reed and the pole piece is prevented in case of undue pressure on the face plate, without any reduction in effectiveinertia reaction types, of bone conduction re ceivers are combined with the result that a more emcient and more effective instrument is produced. v

For a more complete understanding of the in- :vention reference may be had to the-accompany- Figure 1 illustrates the new vbone conduction receiver of this invention,-supported on the headband and connected in .a microphone circuit;

Fig. 2 is an enlarged-,longitudinal section through the receiver of Fig. 1;

Fig. 3 is an enlarged longitudinal section through a modified form of the receiver of Fig. 2; Figs. 4, 5 and 6 are enlarged longitudinal sections through other modifications .ot the invention; Figure 'l is a view in side elevation of a modified type of receiver embodying the ,invention;

and

' Referringto Fig. 1, the bone conduction re theinner ear of the user.

Figure 8 is a view in section taken on lines-8 Of P181118 '1. a so ceiver A includesa casing ll, of hard rubber, phenolic resin, or the-like. havinga face plate Y H. with a button the latter, and with opposite surface slots id in which the prongs it or the fork-II of the headband It, or other hoide'r, are pivotahy inserted. .An electric cord-ill, connectible-with separable I! proiectins'slishtly beyond cases a ing and the vibrating contactor or am plate.

illustrated in Fig; 2 is supported by a headband l8,'or the like, in the manner shown in -Fig; 1, so that the face plate II and the button l2 are simultaneously in operative contact with the bone structure ofthe user, such as the mastoid eminence. Because the. inertia of the magnetic structure, including the magnet 25, the pole piece 28 and the speech coil 21, is considerably greater than the inertia oi the reed 22 and its appurtenant parts, the vibration effected by the electromagnetic means in response to voice currents, causes this magnetic structure in effect to remain stationary while the reed 22 and the casing {2-, ii vibrate as a unit, thus transmitting their vibrations through the bone structure to The relative vibrations and the magnetic structure are utilized in this receiver by means ot the button ILwhich is carried by the magnetic structure and thus trans.- mits concentrated vibrations; through the. bone v structure-0f the user. The spacing of the button i i2 from the fulcrum of the cantilever magnetic structure carrying it, causes the button i2 to-prm duce powerful gvibrations of smell amplitude, I whereby power-requirements are reduced. fie

cordingly, the receiver illustrated in'l ig. 2 combines theadvanta-Ees of the button and inertia or reaction type receivers, operating in the chap acteristic fashion of each. of them without embodying their disadvantages:

The receiver-illustratedin cation of the receiver of Fig. 2- in that the bar magnet SI is supported .by a spring.;strip 86 on the reed 31, which alsowzarries a stiif cantilever spring 38, with respect to which the bar-magnet electric connectors ii to the electromagnetic means within the casing l0, includes two wires ll, connected in the circuit of the battery 29 and the microphone. 2!. Suitable amplifyin means, not shown. may be provided. The receiver A is adapted'to be placed. with its button l2 and face plate ll simultaneously inoperative contact with the bone structure of the user, such as on the mastoid eminence behind the ear, with a headband 18 supporting the receiver A in that posi- "tion.

As is illustrated in Fig. .2, the tympanuzn or -reed 22 is secured rigidly by screws 23, or the like, to the One end-,il; of this reed 22, is turned upwardly and supports cantilever-iashion .the elongated har magnet '25 .having'at' its;free' d the pole I piece 2'. the end-01.; which'is spaced from the corresponding surface the reed 22 to term a narrow air gap., The speech coil 21 maybe carby the pole piece in, and its terminals are two corresp ndina contact plates 20 inlaid in the inner surface of face plate II and each elecu and plug a to connector l2 -oi the electric Adjil stably threaded in t0 the bar magnet I5 3E and consequently the air gap is adjustable by means of the stem M and nuts 4! interconnecting spring 38 and the bar magnet 85. The advent- 40 taxes of adiustability oithe air gap and the m inner surface of the faceplate fl i by means of screws is a stem 28 having at its free end the button i a: which projects approximatei fval to'srof an inch beyond the surface of the face-plate ll, in the manner iliustrated in ex'aagerated form in Figs. 1 and 2,.- The degree ot'proiection oi-the screwing stem-2 2 in or II" may lie-adjusted by 2i and locking it in ad- In operation, the bone conduction receiver 7 button l2 semis-the surface of the fac plate tion of 1s avoidance of fatigue of th vibrating metal-by this spring structure are discussed in greater detail in my 'copending application Serial No. 733,739, flied July 5, 1934, which discloses the structure of mg. 3 just described...

In addition toaiiording a means for adjust-- ment of the air gap and the like, stem as also carries the button i2- and is adjustable axially,

in the bar magnet to'vary the degree of. projection of the button H, which is locked in adiuswti position by lock nut M. The, operation oi the form illustrated in Fig. 3 is the samehs that described in connection with the arrangement or Figs. 1 and 2.

in the modification illustrated in Fig. i, the bar-magnet .42 is rigidlysecured to the back of 64. so that the Feed 85, extends parallelixi-tlie inner sur e-cc of the face plate 45 and is iree to vibrate relatively thereto in response. to-energizatiomof the electromagnet-m the inertia of 'e'reed 46 is small compared to the inertia of, magnetic structure including the bar magnet-J2, the pole'piece l1 and the voiceeoil 48, together with the casing 43 and faceplate 4!, the reaction eifect is relatively" the mass of the reed QI, the reaction eflect may-be increased at mall, .a1th0u8h,. by increasing will.

1 1hreaded through 4: is a stem s cirbetween the reed 22 F isa my by voice currents. Because r'ying thebutton l2" projectingthrough face plate forming-a relatively small proporsurface area of the latter; The I degree Ofwbiection 'oibutton .l2'-' beyond the:

surface of faceplate 4 may be varied by screwcushioning material. eflect, a button. the area of Which is the entire reed 45 by Contact of button l2" with the bone.

'I'hedegree of vibration of the casing 43 may be varied by increasing or decreasing the mass of the reed l5 and button II". For example, by increasing their mass the reaction efiect isincreased.

In the form of the invention illustrated in Fig. 5, the bar magnet 5| is rigidly secured by screws 52 to the casing 53, while the reed 54 is rigidly secured by screws 55 to the face plate 55; The face plate 55 and th cooperating surface of casing 53 are spaced apart to permit relative vibration between them and this space is filled by a gasket 51 f soft rubber, felt, or other The face plate 55 is, in

area of face plate 55.

Energization of the speech coil 58 in accordance with voice currents, causes reed 54 and face plate 55 to vibrate relatively to the headbandsupported casing 53, so that its vibrations are transmitted to the inner ear through the bone structure and little or no vibration is imparted to the head band. The gasket 51 is sufficiently firm to prevent substantial suppression of the vibration of the reed 54 because of its contact with the head, and also prevents contact or'freezing between the pole piece 59 and the reed 54. as well as preventing access of dirt into the casing 53.

Alternatively, the arrangement of-Fig. may

be modified as illustrated in Fig. 6 by inserting the face plate within the opening of the casing 6|, so that the plate 60 forms a-large pro portion of the area of the corresponding wall of As the reed 62 carrying the face plate 50 is vibrated by the electromagnetic the receiver.

means, including the bar magnet 53, the pole piece 54 and the speech coil 55, all carried by the casing 5|, the vibrations of the reed 52 are transmitted by face plate 50 through the bone structure to the inner ear of the user.

Although the reeds 22 and 31 of the forms shown in Figs. 2 and 3 are supported by the headband I5, inasmuch as the latter is connected herein, it is to be understood that the invention is not limited thereby but is susceptible to changes in form and detail within its scope.

Iclaim:

, 1. In an audiphone, the combination of electromagnetic means adapted to respond to varying currents substantially throughout the audible frequency range, a casin secured thereto, a relatively stiil vibratory member connected to the means for vibration thereby, a contactor secured to the member and movable relatively to the casing and forming at least the major part of a, wall of the casing, resilient sealing means interposed between the adjacent portions of the relatively movable contactor and the casing, and means supporting the casing with the contactor in oper-' ative contact with the bone structure of the user for conducting its vibrations therethrough' to the inner ear.

2. In an audiphone, the combination of a vi-.

bratorymechanism comprising two members, relatively stifl' spring means connecting said members permitting a limited relative movement between at least portions of both'members, electrical means adapted to respond to varying currents within the audible frequency range secured rectly secured to the contactor for holding the said last named member substantially stationary 4D with the contactor in engagement with the bone and said supporting means, without suppression to the casing in, II to which the reeds 22 and- 31 are secured, these instruments may be supported by their electromagnetic means, if desired, simply by connecting the headband t the bar magnet 25 and 35, or the like, through suitable openings in the wall ofeasing. II). An example of this arrangement is illustrated in Figs. 7 and 8, wherein the prongs H of the fork l5 of the headband I6 are shown projecting through openings I3 in the wall of the casing Ill and pivotally connected to the bar magnet 25'.

Similarly, although the electromagnetic means is supported by the headband in Figs. 4, 5 and 6, inasmuch as the latter is connected to the casings I3, 53 and BI, these instruments may be by said supporting means when said electrical means is energized. for transmitting the vibrations of the contactor through the bone structure to the inner ear.

3. In an audiphone, the combination of a vibratory mechanism comprising two members, relatively stiff spring means connecting said members permitting a. limited relative movement between at least portions of both members, electrical means adapted to respond to varying currents within the audible frequency range secured to said'portion of one of said member and operatively opposed :to said portion of the other memch'ange of support would be to convert the forms receivers and the forms of Figs. 4, 5 and 6 into inertia or reaction type receivers.

ber for relatively vibrating the same, a, casing for said mechanism secured to one of. said members, a contactor for engagingthe user and forming a wall of said casing, and supporting means directly mechanically connected to said other member for holding the same substantially stationary in use for vibration of the contactor and casing relatively thereto when said electrical means is energized, whereby the contactor transmits its vibrations through the bone structure to means connecting said members permitting a limited relative movement between. at least portions of both members, electrical means adaptedto respond to varying currents within the audible frequency range operatively electrically coupled to said portions of said members for relatively vibrating the same, a relatively fiat contactor for engaging the user secured to the member having less inertia and having an area at least as large as the said portion of said last-named member, and supporting means directly mechanically cou pled to the member having greater inertia for holding the same substantially stationary in use for vibration of the contactor and the low inertia member relatively thereto when said electrical means is energized, whereby the contactor transmits its vibrations through the bone structure to the inner ear when operatively connected thereto by said supporting means.

5. In an audiphone, the combination of a vibratory mechanism comprising two members having unequal inertias, relatively stiff spring means connecting said members permitting a limited relativemovementbetween at least portions of both members, electrical means adapted to respond to varying currents within the audible frequency range operatively electricallycoupled to said portions of said members ior relatively vibrating the; same, a relatively flat contactor for engaging the user secured to the member having less inertia and having an area at least as large thecontactor and the reed member relativelyas the said portion ofsaid last-named member,

supporting means directly mechanically coupled to the member having greater inertia for holding the same substantially stationary in use for vibration of the contactor and the low inertia member relatively thereto when said electrical means is energized, whereby the contactor transmits its vibrations through the bone structure to the inner ear when operatively connected thereto by said supporting means, and resilient means interposed between said contactor and a fixed part of the audiphone for limiting the movement of the contactor relatively to'said part under excessive pressure between them.

6.'In an audiphone, the combination of a vi- 'br'atcry mechanism comprising a relatively flat reed member and a cooperating electromagnetic member including a permanent magnet, rela-- tively stiff spring means connecting said members permitting a limited relative movement between at least portions oi. both members, a voice coil operatively associated with said electromagnetic member and adapted to relatively vibrate said portions of said members when energized by varying currents within the audible frequency range, a relatively flat contactor for engaging the user secured to said reed member and having an area substantially coextensive therewith, and a supporting means directly mechanically coupled tcsaid magnet for holding th'e same substantially stationary in use for vibration of thereto when said voice coil means is energized. whereby the contactor transmits its vibrations through the bone structure to the inner car when operatively connected thereto by said supporting means. I

7 In an audiphone, the combination or a resilient headband, electromagnetic means adapted to respond to varying currents throughout the audible frequency range, a. casing enclosing said electromagnetic means and having a wall forming a contactor, means connecting said headband to saidelectromagnetic means for holding said electromagnetic means substantially stationary, and an armature fixed to said contactor for vibration by said electromagneticmeans, said armature being substantially stiiier than the headband to prevent the resiliency of the headband from appreciably flexing and thereby suppressing vibration of said armature.

8. In an audiphone, the combination of a resilient headband, electromagnetic means adapted to respond to varying currents throughout the audible frequency range, a. casing enclosing said electromagnetic means and having a wall movable relatively to the remainder of said casing and forming a contactor, means connecting said headband to said electromagnetic means for holding said electromagnetic means substantially stationary, and an armature fixed to said contactor' for vibration by said electromagnetic means, said armature being substantially stifier than the headband to prevent the resiliency of the headband from appreciably flexing and thereby suppressing vibration of said armature.

9. In an audiphone, the combination of a vibrating mechanism comprising two members, relatively stiii spring means connecting said meinbers and permitting limited relative movement between at least portions of both members, electrical means adapted to respond to varying currents within the audible frequency range secured to said portion of one of said members, and operatively opposed to said portion of the other memher for relatively vibrating the same, a casing for said mechanism secured to saidother member, said casing having at least one opening therein adjacent to said orie member, and supportingmeans directly mechanically coupled to said one member through said casing opening, whereby said casing and said other member are free to vibrate relatively to said supporting means and said one member totralismit the vibrations to the inher car when said' casing is operatively connected to the bone structure of the user by said supporting means.

HENRY KOCH.

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