US 2549259 A
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Patented Apr. 17, 1951 RADIO TUNER FOR HEARING AID APPARATUS Einar A. Strommen, Merrick, N. Y., assignor to Dictograph Products Company, Inc., New York, N. Y., a corporation of Delaware Application January 10, 1948, Serial No. 1,568
4 Claims. (01. 250 -40) The present invention relates to hearing aid apparatus and more particularly, to novel radio tuner apparatus for adapting a conventional hearing aid device to radio broadcast reception, although it is not limited to such use.
Heretofore, satisfactory radio broadcast reception has been difiicult of accomplishment by the wearer of a hearing aid device. If broadcast reception is achieved through the hearing aid transmitter and amplifier from the audible output of a radio loudspeaker, the quality is liable to be poor, since the distortion in the overall system will be a function of the product of the distortion in the radio amplifier and the distortion in the hearing aid amplifier. On the other hand, if the hearing aid device is directly connected to the audio amplifier of the radio receiver, special connections must be made and the wearerof' the hearing aid device cannot move about freely but must keep himself within the limits imposed by the conductors connecting his hearing aid device to the radio receiver.
The primary purpose of the present invention is to enable the wearer of a hearing aid device to avail himself of radio broadcast reception in a simple and highly effective manner without resorting to either of the expedients noted above. This is accomplished in accordance with the invention, by providing novel radio tuner apparatus for hearing aid devices which is adjustable over a predetermined range to enable the wearer of'a hearing aid to select any one of a group of radio broadcast stations. The novel tuner apparatus is small and slightly in appearance, in conformity with the requirements of hearing aid apparatuses, and is adapted to be assembled detachably in operative relation to a conventional hearing aid with case.
It will be understood that the invention en ables the wearer of a hearing aid to enjoy the advantages of radio reception with much greater freedom than has been possible. heretofore. By virtue of the novel tuner apparatus of the invention, the wearer can select any particular station of the group of stations receivable and can listen toa program Without disturbing other persons in the room with him. Further, since the signals being received pass only through his hearing aid amplifier, thereception may be accomplished with relatively high quality.
Additional objects and advantages of the invention will be apparent from the following detailed description of a representative embodiment taken in conjunction with the accompanying drawings, in which: i
Fig. 1 is a view in front elevation of radio tuner apparatus constructed in accordance with the invention;
Fig. 1A is a top view of the apparatus shown in Fig. l;
Fig. 1B is a view in perspective of a friction element used in the apparatus of Fig. 1;
Fig. 2 is a view in elevation of the radio tuner apparatus shown in Fig. 1 with the outer shield removed;
Fig. 3 is a side view of the apparatus shown in Fig. 2; and
Fig. 4 is a schematic diagram of a hearing aid circuit including the radio tuner apparatus of the invention.
Referring now to Figs. 2 and 3, typical radio tuner apparatus constructed according to the invention may comprise, for example, a frame It) having an upright member II and top and bottom'arms l2 and I3, respectively. Preferably, the frame l0 should be made of a low loss, nonconducting, nonmagnetic material such as a phenol formaldehyde resin, solid, filled or laminated, as desired. Secured to the upright memher i l in any suitable manner as by means of the nuts l5 and bolts 6, for example, is a substantially U-shaped bracket [4. The upper and lower arms I! and [3 of the U member 14 may be provided with apertures l9 and 20 within which is carried a coil form 2|. Preferably, the U -shaped brackets l4 and the coil form 2! should be made of a suitable dielectric material having low losses at radio frequencies such example.
Wound on the coil form 2| is an inductance coil 22 which is connected in parallel with a condenser 23 supported on the bracket l4, as shown. The winding 22 and the condenser 23 form a tunedcircuit, the resonance frequency of which can be adjusted over a predetermined range by means of a permeable rod member 24 which is slidably mounted within the coil form 2|. The rod member 24 is preferably made of magnetic material and it should be designed in the conventional manner for minimum eddy current losses. By Way of example, it may be formed by ressing powdered magnetic metal mixed with a suitable binder in a suitable mold.
The junction 25 of the winding 22 and the condenser 23 is preferably grounded to the easing of the apparatus by a conductor 28, which is" electrically connected to a lug 21 maintainedin engagement with a covering shield 28 which sur-.
as Steatite, for
nected by a conductor 29 to a jack-plug 30 mounted in the upright member of the frame In which may be adapted to be inserted in a registering jack 3| formed in the side of a conventional hearing aid 32.
The other junction 33 of the winding 22 and the condenser 23 is-connected-inseries with a condenser 34 and'a conductor 35 to a jack 36' mounted in the upper arm 12 of the frame In. The jack 36 is adapted to receive a plug 3! connected to a conductor 38 which may form'an 3111-.- The tenna lead for the radio tuner apparatus. junction 33 is also connected by a .conductor 39 to a conventional diode rectifier'40; the. other" the radio tuner apparatus is'enclos-ed within acoveringshield 28 which may be securedto the frame in any suitable manner as by theiscrews 43, for example. shield 28 is providedwith a. longitudinal slot 44 through which extends a shaft'45 (Fig; 2) on a member 50 mounted on the permeable rod 24. Secured to the shaft 45 by'means of a screw 46, for. example, is an actuator member 41. The actuator member 41 may have a pointer 41a adapted to register with a plurality of markings 4Blformed on the front'face of the covering shield 28, corresponding to the band of frequencies "to which the tuner is tunable.
Suitable means such as a Phosphor bronze spring 49 (Fig. 1B), for example, may be interposed between the inner face of the covering:
shield 28 and themember 50 on'which the shaft 45v is mounted, to prevent the rod 24 from moving relatively to the winding 22 after it has been set to a particular position by manipulation of the actuator member 41.
,When the, radio tuner apparatus is assembled I toe conventional hearing aid device 32 by in- The j ach The front face of the covering 38 is connected to a standard broadcast antenna or to a conductor such as might be afforded by an electric light circuit or a telephone system, for example. In the latter case, the condenser 34 prevents any D. C. from getting into the resonant circuit formed by the condenser 23 and the winding,22:.
, From' the foregoing, it wi'llbe' understood that the invention enables the wearer of a hearing aid to enjoy the benefits of radiov broadcast reception without-having to listen to a standard radio receiver through his hearing aid device an without having to connect his hearing aid amplifier" directly to" such a receiver. By virtue of the novel, radio tuner apparatus described above, the wearer of 'a' hearing aid device can select the particulariistation. to which he wishes to listen without. disturbing other persons in the same room. Further, the radio tuner apparatus is easily attachable to a conventional hearing aid and is small and sightly in appearance.
While a specific form of radio tuner: apparatus hasbeen described above, the invention i obviously not limited thereto. Both the values-of the components and the arrangement thereof can be modified as is well known to those skilled-in the art; A-lso, the'novelradio tuner of the inventionis not limited to 'use with hearing aid devices but can be readily adapted forusewith any conven tional audio amplifier system; The representative embodiment chosen forpurposes of i1lustra'--= tion is not intended to be restrictive in anyway-- but issusceptible of numerous changes inform and detail within" the scope' of the appended.
I claim: 1. Radio tuner apparatus comprising anv iii-'- sulating support having an upright member and top and-bottom side members extending substantially perpendicularly thereto,,a tuned circuit including a capacitanc and an inductance inparallel carried by said supportbetween said top and bottom side members, and a substantially U-shaped shieldhavingparallel portions securedj' at opposite sides of said support to form front and rear sides of said apparatus and havinganother portion formingw one other side of said 311)? paratus,vsaid upright and top. and bottom side members formingtop and bottom sidesandan other side of said apparatus.
.2. Radio tuner apparatus comprising an insulating support having ,an upright member and top and bottom side members extendingsubstantially,perpendicularlysthereto, ,a timed. circuit in.- cluding'a capacitance and an inductance in par.-
' allelfcarried by said support between said .top and several hundred turns of Number 36 wirehaving an inductance of approximately 65.5 h. without the rod 24; and the condensers 23 and 40 may have values of 130 lL/Lfa and 30 ,LL,LLf., respectively,
tuned selectively to frequencies in the rangefrom.
15100 kc. per second to 550 kc. per. second.
In an area where the signal strength oflthe local broadcast station is relatively strong, the
antenna 38 may be. a relatively shortlength of wire. Atgreater distances from"broadcaststations; better results will be obtained if the-lead" bottom side membersramagnetic core forsaid in:- ductance, a substantially U.-shape d shield having parallel portions secured. on .opposite. sides .of said. support to formfront and. rear sides ofsaid apparatus andhaving another portionforming another side of said 'apparatus,said upright and top] and bottom side members formingto andbot- 7 tom sides, andanother. sid of .said. apparatus means forming aslotin said shield,fand actuator; means carried by thez'core and 'having'a portion" extending through said slot.
3. Radio tuner apparatus comprising an; insulating support'having an upright member and" top and bottom'side members extending substan'-'- tially perpendicularly thereto, a tunedcircuitiheluding a capacitance andan inductance in par-'- allel carried by said" support between said top and bottom side members, a-magnetic core for" said inductance, a substantially U-shapedshield having parallel portions secured on opposite sides of said support to form front and rear sides of said apparatu and having another portion forming another side of said apparatus, said upright and top and bottom side members forming top and bottom sides and another side of said apparatus, means forming a slot in the front side of said shield, core actuator means disposed externally of said shield and having indexing means thereon, means forming markings on said shield adapted to cooperate with said indexing mean to indicate generally the frequency to which said tuned circuit is tuned, means extending through said slot and connecting said core actuator means to said core, and resilient means interposed between said core and the interior of said shield for rendering said core relatively difiicultly movable.
4. Radio tuner apparatus comprising an insulating support having an upright member and top and bottom side members extending substantially perpendicularly thereto, a pair of electrical connectors mounted in said upright member, an electrical connector mounted in said top side member, a tuned circuit including a capacitance and an inductance carried by said support between said top and bottom side members, unilaterally conductive means connected to one terminal of said tuned circuit and to one of the electrical connectors in said upright member, a second capacitance connected to said one terminal of the tuned circuit and to said electrical connector in the top side member of the support, an electrical connection between the other terminal of said tuned circuit and another electrical connector in said upright support member, a substantially U-shaped shield having parallel portions secured on opposite sides of the support to form front and rear sides of the apparatus and having another portion forming another side of the apparatus, said upright and top and bottom side mem bers forming top and bottom sides and another side of said apparatus an electrical connection between the shield and said another terminal of the tuned circuit, means forming a guid slot in the front side of said shield, a member carried by said core and slidable in said guide slot, core actuator means disposed externally of said shield and secured to said last named member, indexing means on said core actuator means, means forming markings on the shield in the vicinity of said slot adapted to cooperate with said indexing means to indicate generally the frequency to which the tuned circuit is tuned, and resilient means between said member on the core and the adjacent portion of the shield for rendering said core relatively difficultly movable.
EINAR A. STROMMEN.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS