US3155780A

US3155780A - Microphone and mounting means assembly

Info

Publication number: US3155780A
Application number: US80916A
Authority: US
Inventors: Louis R Burroughs
Original assignee: Electro Voice Inc
Current assignee: Bosch Security Systems Inc
Priority date: 1961-01-05
Filing date: 1961-01-05
Publication date: 1964-11-03
Anticipated expiration: 1981-11-03

Description

Nov. 3, 1964 1.. R. BURROUGHS MICROPHONE AND MOUNTING MEANS ASSEMBLY Filed Jan. 5. 1961 I Patented Nov. 3, 1964 Indiana Filed .ian. 5, 1961, Ser. No. 80,916 ll Chums. (Cl. 179146) The present invention relates to means for mounting a microphone, and to an assembly of a microphone and mounting device attached to the microphone.

Because of the fact that a microphone responds to sound pressures, it is also sensitive to the pressure of the air of its environment when the microphone is moved. The greater the sensitivity of a microphone to sound pressures, the greater will be its sensitivity to movements.

Television and some public address applications for microphones require the microphone to be positioned remote from the sound origination region. Sensitive directional microphonesare adapted to such applications, since they minimize the background noises which are picked up by the microphone. It is, however, generally necessary to move the microphone during use, and for this reason, the microphone is positioned at the end of a movable sound boom. The sound boom also facilitates positioning of the microphone at the optimum location for optimizing the ratio of signal to background noises while still keeping the microphone out of view or out of the way of other equipment.

Patent No. 1,805,362 issued to Ellis discloses an early type of microphone and support means assembly in which the microphone is mounted within a ring of a stand by eight springs attached to the ring at four equidistant points. and attached to the microphone at four points located between the four points on the ring. The ring is mounted on a standard which is intended to be disposed upon a floor, and it is not inteneded that the microphone be changed in position during use. A similar type microphone and support assembly is shown in Patent No. 1,653,109 to Krietemeyer, but this microphone support utilizes only four springs extending between the ring and the microphone.

The present inventor has described a greatly improved microphone and support assembly for use on a sound boom in Patent No. 2,920,150. The microphone support set forth in this patent utilizes four supporting arms which depend from the boom and which support at their ends opposite the boom four elastomer bands which extend between the microphone and the arms. The elastomer bands are selected to achieve the proper compliance to form a mechanical resonance with the mass of the microphone which is below the audible frequency range of the microphone. The microphone support described in this patent has been effective in avoiding pickup of sound as a result of boom vibration or movement, but it requires more space than is desirable and is not readily adapted for use with larger and heavier microphones.

It is one of the objects of the present invention to provide an improved microphone and support assembly which has a mechanical resonance frequency below the fre quency response range of the microphone.

It is a further object of the present invention to provide a microphone and support assembly which has a more nearly uniform compliance to displacements in all directions.

It is also an object of the present invention to provide a microphone and support assembly which is more suitable for use with microphones of greater mass and larger size than heretofore.

Other objects and advantages of the present invention will be more fully appreciated from a further consideration of this specification, particularly when viewed in the light of the drawings, in which:

FIGURE 1 is a side elevational view of a microphone and support assembly constructed according to the present invention;

FIGURE 2 is a front elevational view of the microphone and support assembly illustrated in FIGURE 1; and

FIGURE 3 is a view of one of the compliant cord members which are illustrated in FIGURES 1 and 2.

FIGURES 1 and 2 show the assembly of a microphone 10 and a support or mounting means 12 for the micro phone. The microphone illustrated is a line type micro phone which is more fully described in the patent application of Wayne A. Beaverson and Robert Ramsey entitled Electroacoustical Apparatus," Serial No. 848,120, filed October 22, 1959. The microphone support may be utilized with other types of microphones, however, such as the microphone described in the patent application of Alpha M. Wiggins entitled Unidirectional Microphone, Serial No. 403,099, filed January 11, 1954. The microphone 10 has a casing 14 which is cylindrical in shape and terminates at its front end in a cylindrical portion 16 of smaller diameter than the central portion of the casing, designated 18, thus forming a shoulder or outwardly extending flange 20 confronting the smaller diameter cylindrical portion 16. A second cylindrical portion 22 of smaller diameter than the central portion 1% of the casing 14 is disposed at the rear of the casing, and the casing 14 also forms a shoulder or flange 24 confronting the cylindrical portion 22. A cylindrical connector 26 of smaller diameter than the cylindrical portion 22 extends coaxially therefrom to provide the electrical connection to the microphone. Also, a cylindrical perforated tube 28 of smaller diameter than the cylindrical portion 16 extends coaxially from the cylindrical portion 16. The perforated tube 28 is the front sound entrance for the microphone and is characteristic of line type microphones, and is not a necesasry element of the microphone and support assembly. However, the microphone support of the assembly is particularly adapted for use with line type microphones due to its ability to perform with heavy microphones and microphones which have their weight distributed throughout a wide region.

The support means 12 is mounted on a sound boom 30, usually at the end of the boom, but it is to be understood that the support means 12 may in the alternative be mounted to a standard, or the like. A pivot member 32 extends between the sound boom 30 and a support bracket 34-. The support bracket 34 has a plate portion 36 which abuts one side of a plate portion 38 of the pivot member 32, and an extension portion 40 which extends from the plate portion 36 in alignment with the plate portion 38 of the pivot member 32. A plate 42 is secured to the surface of the extension 40 of the support bracket 34 by a screw 44 and abuts the side of the plate portion 38 of the pivot member 32 opposite the plate portion 36 of the support bracket 34. A bolt '46 extends through apertures in the plate portion 36 of the support bracket 34, plate portion 38 of the pivot member 32, and the plate 42, and engages a locking knob 48. The locking knob 48 and bolt 46 exert sufiicient pressure on the plate portion 36 of the support bracket 34 and plate 42 to securely engage the plate portion 38 of the pivot member 32.

The support bracket 34 terminates at its end opposite the plate portion 35 in a portion 50 which mates with a protrusion 52 of a supporting framein the form of a ring 54, and is secured thereto by bolts 56. The ring 54 is disposed about the casing 18 of the microphone lti, and has an inner diameter substantially greater than the diameter of the casing to permit movement of the casing 18 without contact of the casing with the ring. The ring 54 has four posts 53 which extend outwardly from the outer surface of the ring and are equally spaced about the ring. The posts 53 are disposed in the plane of the ring 54, and a cord bracket 6%) is mounted on the end of each post 58 opposite the ring 54. Each cord bracket 66 has two indentations 62 disposed on op posite sides of the plane of the ring 54, and the indented portions 6-?- of each cord bracket 60 are bent normal to each other and disposed at an angle of approximately 45 degrees to the plane of the ring 54.

A first shock cord assembly 66 has an elastorner cord 68 of compliant material which engages each indentation on one side of the plane of the ring 54-, and a second shock cord assembly 76 has a compliant elastorner cord 72 which engages each of the indentations on the opposite side of the ring 54. Each cord has a protrusion '73 at the end thereof which engages the cord bracket, and the protrusion abuts one side of the cord bracket. A ring 74 of approximately the same inner diameter as the cylindrical portion 16 of the casing 14 is integral with the ends of the cords 68 of the first cord assembly 65 opposite cord brackets 60 and is also constructed of the same compliant material. The ring 74 engages the surface of the cylindrical portion 16 of the casing 14 and abuts the outwardly extending flange 29 of the casing 14. Since the ring 74 is constructed of compliant material, it will not mar the finish of the casing 14. A metal insert ring 76 is disposed within the ring 74 in order to maintain the shape of the ring 74 and to facilitate positioning of the ring 74 about the cylindrical surface 15.

The second shock cord assembly 70 is of similar construction to the first shock cord assembly 66, and the cords 72 of this assembly are integral with and extend from a ring 78 which engages the surface of the cylindrical portion 22 and the flange 24 of the casing 14. The distance between the flange 20 and the flange 24 of the casing 14 is sufficient to place the cords 63 and 72 under tension, and preferably to position these cords at angles of 45 degrees to the axis of the microphone casing 14. In a preferred construction of the microphone and support assembly, the cylindrical portions 16 and 22 have the same diameter, so that this relation is accomplished by making the distance between the

flanges

20 and 24 twice the distance between the intersection point of the extensions of the cords 6S and 72 attached to a given cord bracket 60 and the closest point of the extended surface of the outer diameters of the

rings

74 and 78.

The

cords

68 and 72 are constructed of resilient materials so that the compliance of the cords function with the mass of the microphone to achieve a mechanical resonance frequency which is below the frequency response range of the microphone, for example, 20 cycles. In this manner, the mechanical oscillations of the sound boom do not result in an electrical output from the microphone even though these oscillations are within the frequency response range of the microphone. In one particular construction of the present invention, which is also illustrated in the drawings, the

cords

68 and 72 are constructed of neoprene with a durometer in accordance with the standards of the Shore Instrument & Manufacturing Company of Jamaica, New York, of approximately 40, and the

cords

68 and 72 have a diameter of approximately /4 inch and a length of approximately 1% inches before stretching. The weight of the microphone in this construction is approximately ten pounds.

It is to be noted that the microphone is cradled within two groups of four compliant cords disposed approximately in the configuration of a square. Further, the cords in each group are dispose in a plane which traverses the axis of the casing 14, and the planes of each group of cords are disposed normal to each other. This con- (t struction has the advantage of supporting the microphone at two widely spaced locations, rather than at a single location, as disclosed in Patent No. 2,920,150, and further providing more uniform compliance for displacements in all directions than prior constructions.

Also, a microphone and support assembly constructed according to the present invention may be disassembled without removing or loosening any bolts, or the like. It is merely necessary to release the cords of one of the shock cord assemblies 6 and 759 and slip the shock cord assemblies from the microphone 10. No bracket is attached to the microphone, and the compliant material of the shock cord assemblies protect the finish of the casing 14 of the microphone.

In the particular construction here described, each shock cord assembly has four cords, although it is only necessary that each shock cord assembly has at least three cords. For example, each of the shock cord assemblies 66 and 7% may have three equally spaced cords, and the microphone It) is then cradled within the six cords between two Widely spaced points. Such a construction does not provide as nearly equal compliance to deflection in all directions as the construction utilizing four cords in each shock cord assembly, and in like manner an improvement is experienced when more than four cords are used in each assembly.

From the foregoing disclosure, those skilled in the art will readily devise many additional constructions within the inventive concept here set forth and many additional applications for this invention. It is therefore intended that the scope of the present invention be not limited to the specific construction here described, but rather only to the appended claims.

The invention claimed is:

1. An assembly comprising a microphone having a first portion and a second portion spaced from the first portion and support means for the microphone wherein the support means comprises a rigid frame disposed adjacent to the microphone, at least three members mounted at intervals on portions of the frame between the first and second portions of the microphone and secured to the first portion of the microphone at their ends opposite the frame, at least three compliant elements mounted at intervals on portions of the frame between the first and second portions of the microphone and secured to the second portion of the microphone at their ends opposite the frame, the members and elements being under tension and the compliance of the members and elements and the mass of the microphone producing a mechanical resonance at a frequency below the electrical frequency response range of the microphone.

2. A microphone and support means assembly comprising the limitations of claim 1 wherein four members are disposed between the frame and the first portion of the microphone, and four elements are disposed between the frame and the second portion of the microphone, two of the members and two of the elements being disposed in a first common plane, and the other two members and other two elements being disposed in a second common plane normal to the first common plane.

3. A microphone and support means assembly comprising the limitations of claim 1 wherein the members are interconnected at their ends opposite the frame to form a unitary structure.

4. An assembly comprising a microphone having an axis and two flanges spaced along the axis and extending outwardly from the axis, a rigid frame encircling the microphone between the two flanges, an assembly having at least three compliant members extending from an apertured portion thereof, the apertured portion being disposed about the microphone and abutting the side of one flange opposite the other flange and the members engaging the frame at their ends opposite the apertured por-- tion thereof, a second assembly having at least three compliant elements extending from an apertured portion thereof, the apertured portion being disposed about the microphone on the side of the second flange opposite the first flange and the elements engaging the frame at their ends opposite the apertured portion thereof and abutting the second flange, the members and elements being under tension and having a compliance producing with the mass of the microphone a mechanical resonance at a frequency below the electrical response frequency range of the microphone.

5. A microphone and support means assembly comprising the limitation of claim 4 wherein four members are disposed between the frame and the first portion of the microphone, and four elements are disposed between the frame and the second portion of the microphone, two of the members and two of the elements being disposed in a first common plane, and the other two members and other two elements being disposed in a second common plane normal to the first common plane.

6. A microphone and support means assembly comprising the limitations of claim 4 wherein the frame comprises a ring disposed about the microphone normal to the axis thereof and spaced therefrom, and each compliant member of the first assembly is mounted on a bracket mounted on the ring which also has attached thereto one of the compliant elements of the second assembly.

7. A microphone and support means assembly comprising the elements of claim 6 wherein the compliant members and elements are disposed at an angle to the axis of the microphone of approximately 45 degrees.

8. A support means for a microphone comprising a ring adapted to fit about the microphone, means for mounting the ring to a stand, at least three mounting brackets mounted at equal distances about the ring, each bracket having a slot extending therein on opposite sides of the ring, a first assembly of at least three compliant cords having a protrusion at one end of each cord and an apertured portion at the other end of said cords, each cord being disposed in the slot of one bracket on the same side of the ring, a second assembly of at least three compliant cords having a protrusion at one end of each cord and an apertured portion at the other end of said cords, each cord of said second assembly being disposed in the other slot of one bracket with the protruding portion abutting the bracket.

9. A support means for a microphone comprising the elements of claim 8 wherein a post is disposed between each bracket and the ring, and the portions of each bracket containing the slots are disposed at an angle to the plane of the ring.

10. A support means for a microphone comprising the elements of claim 8 wherein the cords comprise strands of compliant plastic.

11. An assembly comprising a microphone having an axis, a rigid frame disposed in spaced adjacent relationship to the microphone between a first portion of the microphone and a second portion of the microphone spaced from the first portion along the axis of the microphone, an assembly having at least three compliant members extending from an apertured portion thereof, the apertured portion being disposed about and mounted on the microphone at the first portion of the microphone and the members engaging the frame at their ends opposite the apertured portion thereof, a second assembly having at least three compliant elements extending from an apertured portion thereof, the apertured portion being disposed about the microphone and mounted on the microphone at the second portion of the microphone and the elements engaging the frame at their ends opposite the apertured portion of the second assembly.

References tlited in the tile of this patent UNITED STATES PATENTS 2,235,505 Ryan Mar. 18, 1941 2,628,289 Olson et al Feb. 10, 1953 2,920,150 Burroughs Jan. 5, 1960 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3, 155, 780 November 3 1964 Louis B; Burroughs It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, lines 3 and 4 strike out "and the elements engaging the frame at their ends opposite the apertured portion thereof" and insert the same, after "flangeM in same column 5 line 5.,

Signed and sealed this 30th day of March 1965a (SEAL) Attest:

EDWARD J. BRENNER ERNEST W. SWIDER Commissioner of Patents Attesting Officer

Claims

1. AN ASSEMBLY COMPRISING A MICROPHONE HAVING A FIRST PORTION AND A SECOND PORTION SPACED FROM THE FIRST PORTION AND SUPPORT MEANS FOR THE MICROPHONE WHEREIN THE SUPPORT MEANS COMPRISES A RIGID FRAME DISPOSED ADJACENT TO THE MICROPHONE, AT LEAST THREE MEMBERS MOUNTED AT INTERVALS ON PORTIONS OF THE FRAME BETWEEN THE FIRST AND SECOND PORTIONS OF THE MICROPHONE AND SECURED TO THE FIRST PORTIONS OF THE MICROPHONE AT THEIR ENDS OPPOSITE THE FRAME, AT LEAST THREE COMPLIANT ELEMENTS MOUNTED AT INTERVALS ON PORTIONS OF THE FRAME BETWEEN THE FIRST AND SECOND PORTIONS OF THE MICROPHONE AND SECURED TO THE SECOND PORTION OF THE MICROPHONE AT THEIR ENDS OPPOSITE THE FRAME, THE MEMBERS AND ELEMENTS BEING UNDER TENSION AND THE COMPLIANCE OF THE MEMBERS AND ELEMENTS AND THE MASS OF THE MICROPHONE PRODUCING A MECHANICAL RESONANCE AT A FREQUENCY BELOW THE ELECTRICAL FREQUENCY RESPONSE RANGE OF THE MICROPHONE.