US3187833A - Transducer mounting - Google Patents

Description

June 8, 1965 D. w. FLYGSTAD TRANSDUCER MOUNTING Filed June 17, 1963 INVENTOR; .Demv M 7'24-3740 BY United States Patent 3,187,833 TRANSBUGJER MQUNTlN- Dean W. Flygstad, Roseville, Minn assignor to The Telex Corporation, Tulsa, Okla, a corporation of Delaware Filed lune 17, 1963, Ser. No. 283,331 Claims. (Cl. 18131) This invention relates generally to transducer mountings and is more particularly directed to transducer mountings for isolating and protecting transducers utilized in environments subject to undesirable mechanical vibrations and destructive shock forces.

Although my invention may be useful in many environments, one example of the prior art in which transducers must be effectively isolated from the undesirable disturbing effects of mechanical feedback and the destructive effects of large forces is the hearing aid industry. Due to the relatively small physical size of transducers utilized in present day hearing aids, the problem associated with inoperative transducers due to dropping, for example, the eyeglass type of hearing aid, and the uncomfortable sensations accompanying mechanical feedback through the necessarily hard and rigid casing for the hearing aid has created a need for improved transducer mountings. In the usual installation of a transducer in a hearing aid, a physically separate cavity is provided in a housing for the hearing aid assembly and electrical connection is made through suitable conductors extending through the housing to the remainder of the electronic portion of the assembly. In many prior art devices the use of resilient pads and the like and/or resilient tubing has been utilized to overcome the transducer mounting diificulties. Some of these mounting arrangements have required the use of unnecessarily large cavities to accommodate the presence of, for example, foam rubber pads, and the use of pads and the like has failed to produce uniform results between successive assemblies and in uniform long lived elimination of feedback and the like and in some cases the mounting for transducers has proven to be complicated and expensive to manufacture.

In one embodiment of my invention I provide a molded two-part sheath that is adapted to be placed over and in engagement with a transducer, which is normally of. rectangular parallelepiped shaped, and at each of the corners of the two-part sheath, or boot, a hollow sphere, opening toward the inside of the sheath, is provided as an integral part of the sheath so that there is a bubble-like protuberance at each corner of the mounting structure. The mounted transducer is then placed in an enclosure, or housing, which is suitably dimensioned to accept the transducer and sheath so that the spheres at each corner are in contact with the three mutually perpendicular walls of the housing defining each corner thereof.

Thus, I provide an improved transducer mounting which may be easily manufactured to provide uniform protection from shock and isolation from feedback in all three axes of a transducer. It may be easily fabricated with a high degree of uniformity from commonly available materials. The transducer and mounting may be easily assembled in asmaller housing, or enclosure than heretofore required.

It is therefore an object of my invention to provide an improved triaxial transducer mounting which serves to uniformly protect and isolate a transducer.

It is a further object of my invention to provide an improved transducer mounting which may be easily fabricated of commonly available materials.

Another object of my invention is to provide an improved transducer mounting which may easily be assembled in a smaller housing and that may be manufactured with a lower degree of tolerance while providing improved uniformity of operation between assembled units.

Another object of my invention is to provide an im proved transducer mounting which comprises a plurality of spherical members on a sheath mounted on a transducer to provide a uniform three axis suspension therefor.

A still further object of my invention is to provide improved transducer mounting means which comprises a sheath adapted to engage and hold a transducer and which has a plurality of hollow spheres positioned for engagement with a transducer housing.

These and other more detailed and specific objects will be disclosed in the course of the following specification, reference being had to the accompanying drawings, in Which FIG. 1 shows a portion of a behind-the-ear type of hearing aid assembly which is broken away to show a transducer and mounting therefor in position in the assembly.

FIG. 2 is a front elevation view of an embodiment of the transducer mounting in position on a transducer within a section of a housing therefor.

FIG. 3 is a side view of the transducer and mounting of P16. 2.

FIG. 4 is a top view of the transducer and mounting of *lG. 2.

FIG. 5 is an enlarged perspective drawing showing one corner of a transducer mounting in position in a housing, or container therefor, from the inside.

FIG. 6 is a plan view, partly in section, of a further embodiment of my invention.

FIG. 7 is a sectional view of the embodiment shown in FIG. 6 taken along section line 7--7.

Referring now to FIG. 1 of the drawing, a housing for a conventional behind-the-ear type of hearing aid is indicated generally by the reference character 19. In a behind-the-ear type hearing aid assembly, a tube and earpiece (not shown) are connected to the front end and the entire unit is supported on the ear. In the particular embodiment shown, which is representative of a number of commercially available hearing aids, a microphone transducer 15 is mounted within a cavity, or housing 12 at the lower rear end of housing 19 which is provided with an opening 11 in communication with sources of compressional wave energy. Transducer 15 is shown within a two-part mounting member, indicated by reference characters 13 and 14, each of which is provided with a hollow sphere or protuberance at each corner thereof. It will be understood that while I have shown my invention as embodied in a hearing aid, its applications and uses are not in any manner restricted to such embodiment and it is contemplated that those skilled in the art, upon becoming aware of the principles of my invention, will find uses in many other environments and applications.

In FIGS. 2, 3, and 4 the several views of the illustrative embodiment of my invention show the transducer mounting as a two-part member comprised of sheaths, or boots, 13 and 14 which are adapted to receive and engage a rectangular transducer 15, which may be of the type commonly used in the hearing aids. Transducer 15 is provided with an opening 16 for the transmission of compressional wave energy, and housing It) is provided with an opening 11 which is adapted to register with opening 16 in sound transmitting relationship. At each corner of members 13 and 14, there is a hollow sphere Ztl positioned so that its center is coincident with a corner and members 13 and 1d are suitably dimensioned with respect to the nominal dimensions of the housing, or cavity, 12 so that when the transducer and mounting are placed Within the cavity each of the spheres on the corners of the mounting is in engagement with the three mutually perpendicular sides of housing 12 which define each of the corners therein.

In one operative embodiment, members 13 and 14 were fashioned out of soft latex material of -15 durometer by a dip process and all of the wall thicknesses, including those of the spheres 211, were .005 inch. The overall length of members 13 and 14 was .420 inch, the height of each of members 13 and 14 was .280 inch, and the depth of members 13 and 14 was .180 inch. The inside diameter of the spheres 2%) was .031 inch. These dimensions and material when used in combination with a standard commercially available hearing aid microphone provided a triaxial shock resistance, before the spheres were completely flattened, of gs. As further examples of materials which may be satisfactorily employed for constructing my invention, a 20 durometer neoprene or silicone rubber may be employed.

Referring now to the broken away sketch of FIG. 5,

one-corner of member 14-, which includes a spherical protuberation 21), is shown in an attitude which might normally obtain in the absence of any external forces. At the eight corners in the rectangular cavity of housing 12, each of the intersecting mutually perpendicular walls of the illustrated embodiment is in engagement with portions of the sphere along, for example, X, Y and Z axes indicated by the dotted arrows and there may, or may not, be a slight flattening of the sphere. The areas of contact or engagement are indicated by reference characters 45, 25, and 35 respectively. When a force is directed along any of the axes shown by the dotted arrows, sphere 20 will tend to flatten out or be deformed so that the respective contact areas 45, 25 and be come larger as the sphere is deformed and the deformation of the sphere will absorb the energy without damage or transmission of mechanical vibrations to the transducer contained therein.

It may also be appreciated that deformation of the spheres due to forces exerted on the transducer may compress the air, or other gas, present within the spheres. Under certain conditions it may prove desirable to utilize this additional energy absorbing medium by constructing the sheath to confine the air within the spheres by providing a snug close fitting engagement with the transducer or, for example, through the use of suitable adhesive materials for attaching the sheath to the transducer.

Those skilled in the art may appreciate from a consideration of the drawing of FIG. 5 the triaxial characteristics of my invention and it may readily be observed that a force applied to the transducer and mounting will be absorbed no matter what direction it may take and that the magnitude of the force which may be absorbed is dependent upon the mass of the transducer and the physical characteristics of the material utilized for the mounting.

While I have illustrated my invention as a mounting for a transducer having the shape of a rectangular parallelepiped, suitable triaxial mounting characteristics may be obtained with, for example, a cylindrical as well as other forms and types of transducers by proper placement of a plurality of spheres of suitable dimension as may be determined through experimentation by one skilled in the art upon becoming familiar with the principles of my invention.

Referring now to FIGS. 6 and 7, a further embodiment of my invention is shown illustrated as applied to a cylindrical form of transducer. In FIGS. 6 and 7, a cylindrical housing dd, which may be fabricated of suitable plastic material, is shown adapted to receive a complementary configured cylindrical transducer of substantially the same dimensions as the inside of a two-part sheath member indicated generally by the reference character 4-1. As may be noted on the drawing, the intersection of the side and end surfaces of the two-part sheath member 41 is provided with a plurality of spherical protuberances indicated generally by reference character 42. Sides 43 may be seen to intersect with ends 44 and 45 of two-part sheath member 41. The protuberances are suitably dimensioned with respect to the interior dimensions of housing 44B and the exterior dimensions of twopart sheath member 4-1 so as to provide an easily fabricated and efficient mounting arrangement for a transducer to be contained within two-part sheath member 41.

It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit'and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by Letters Patent is:

1. Mounting means for positioning and suspending a transducer of rectangular parallelepiped shape in a housing therefor comprising, a sheath member dimensioned to substantially enclose and hold a transducer of substantially rectangular parallelepiped shape, said sheath member having a hollow protuberance at each corner thereof, said hollow protuberances being dimensioned to engage corresponding surfaces in a housing for said transducer.

2. The mounting means of claim 1 in which the hollow protuberances are substantially spherical in shape and the center of the spheres is coincident with the intersection of the three mutually perpendicular surfaces at each corner of the transducer.

3. The mounting means of claim 2 in which compressible fluid is entrapped in each of the spheres.

4. In combination with a transducer and a complementary configured housing therefor, mounting means for resiliently supporting the transducer in the housing comprising in combination; a sheath member adapted to substantially enclose a transducer, said transducer and said sheath member having a plurality of intersecting side portions and said sheath member having a plurality of spherical protuberances disposed at predetermined locations and extending outwardly from said intersections to resiliently support said transducer in a complementary configured housing.

5. The apparatus of claim 4 in which the transducer 7 is a rectangular parallelepiped and the protuberances are disposed at the corners of said transducer.

References Cited by the Examiner UNITED STATES PATENTS 2,252,846 8/41 Giannini 61. al. 179-180 2,952,748 9/60 P0561! et al. 179-107 3,048,668 8/62 WEISS 179-179 FOREIGN PATENTS 556,137 9/43 Great Britain.

LEO SMILOW, Primary Examiner.

Claims (1)

1. MOUNTING MEANS FOR POSITIONING AND SUSPENDING A TRANSDUCER OF RECTANGULAR PARALLELEPIPED SHAPE IN A HOUSING THEREFOR COMPRISING, A SHEATH MEMBER DIMENSIONED TO SUBSTANTIALLY ENCLOSE AND HOLD A TRANSDUCER OF SUBSTANTIALLY RECTANGULAR PARALLELEPIPED SHAPE, SAID SHEATH MEMBER HAVING A HOLLOW PROTUBERANCE AT EACH CORNER THEREOF, SAID HOLLOW PROTUBERANCES BEING DIMENSIONED TO ENGAGE CORRESPONDING SURFACES IN A HOUSING FOR SAID TRANSDUCER.

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