US 3735021 A
Electrically conducting pivot joint which provides continuous shielding. The inner conductor is connected through the pivot joint and the outer conductor is connected by shielding elements around the path of the inner connector. The joint is specifically designed for the lightweight headset. Complete rotational movement and angular movement of the boom is available. At the same time the boom is held in a set position. A high impedance transducer can be used for the microphone.
Description (OCR text may contain errors)
Waited States Patent [191 Ennis et al.
[451 May 22, 1973 ELECTRICALLY CONDUCTING PIVOTAL JOINT Inventors: David Raynes Bonis, N. Dorchester,
Putnam, Ontario; Eric Foster, London, Ontario, both of Canada  Assignee: Northern Electric Company Limited,
Montreal, Quebec, Canada Filed: June 11, 1971 Appl. No.: 152,244
U.S. Cl. ..l74/86, 179/156 A Int. Cl. ..H01r 5/00 Field of Search ..l74/86, 705;
 References Cited UNITED STATES PATENTS 6/l965 Warshawsky 174/86 X 8/1969 Harris et al 174/86 12/1935 Pocock etal ..l79/l56A 4/1969 Bryant et al. ..l79/l56A FOREIGN PATENTS OR APPLICATIONS Italy 1 74/86 Australia 174/86 Primary ExaminerBemard A. Gilheany Att0meyS. T. Jelly [5 7] ABSTRACT Electrically conducting pivot joint which provides continuous shielding. The inner conductor is con nected through the pivot joint and the outer conductor is connected by shielding elements around the path of the inner connector. The joint is specifically designed for the lightweight headset. Complete rotational movement and angular movement of the boom is available. At the same time the boom is held in a set position. A high impedance transducer can be used for the microphone.
10 Claims, 4 Drawing Figures ELECTRICALLY CONDUCTING PIVOTAL JOINT This invention relates to pivotal joints, for example pivotal joints for the movable connection of a mouthpiece and support beam to a headset, and in particular to pivotal joints with provision for a continuous inner electrically conducting path and a continuous outer electrically conductive and shielding path.
Previously it was not required that a pivotal joint for a headset be electrically conducting and electrically shielded. Transducers were often located away from the mouth of the user, with an acoustic tube or channel in a boom extending from the transducer, with ports in the boom for positioning adjacent to the users mouth. Alternatively, the transducer may be located near the users mouth, but previously transducers were of a low impedance type and it was possible to use unshielded leads to the amplifier. Such leads could easily be led past the pivoted joints. Also it was usual to provide more than one joint to permit accurate location of the transducer close to the users mouth.
The invention enables the use of a high impedance transducer located adjacent to the users mouth. Normally, as shielded leads are required for such transducers, the use of shielded leads would introduce difficulties at joints. By the use of an electrically conducting joint, of the correct formation, the use of a shielded lead at the joint is avoided. Further, improved joint flexibility is obtained and only one pivotal joint is required for correct positioning of the mouthpiece with the transducer.
The invention provides an electrically conducting pivotal joint for connection between a tubular member, having inner and outer coaxial conductors, and a coaxial conductor, the joint comprising a spherical member of electrically conducting material and having an aperture therethrough for receipt of said tubular member and electrical connection to the outer conductor of the tubular member; first and second bearing members in opposition on the spherical member; a spring urging the bearing members into engagement with the spherical member; an axially extending electrical connecting means adapted to connect electrically at its forward end with the inner conductor of the tubular member and to connect electrically at its rearward end with the inner conductor of said coaxial conductor; a housing of electrically insulating material; means supporting the electrical connecting means in said housing; tubular electrically conducting means mounted on said housing coaxially at said, electrical connecting means and adapted to electrically connect the outer conductor of said tubular member to the outer conductor of said coaxial conductor; and means for retaining said bearing members and spherical member in position relative to said housing.
The invention will be readily understood by the following description of certain embodiments by way of example only, in conjunction with the accompanying drawings in which:
FIG. 1 is an illustration of one form of headset embodying the invention;
FIG. 2 is a longitudinal cross-section through one form of joint as used in the arrangement of FIG. 1, to a greatly enlarged scale;
FIG. 3 is a longitudinal cross-section through another form of joint; and
FIG. 4 is a longitudinal cross-section through a fur ther form of joint.
As illustrated in FIG. 1, a headset generally indicated at 10, comprises a support housing, or structure 11, which is positioned over the ear of the user. A metal boom 12 is connected to the housing 11 by means of a pivotal joint 13 in accordance with the present invention. At the end of the boom 12 is a mouthpiece 14 which comprises a high impedance transducer. The boom acts as a coaxial connector, there being a central conductor insulated from the metal tube forming the boom. An amplifier is located in the housing 1 1. A flexible connecting lead 15 is provided and also an earpiece 16 mounted on the end of a flexible tube 17.
FIG. 2 illustrates in detail, to a considerably enlarged scale, one form of the joint 13 in FIG. 1. As seen in FIG. 2 the metal tube 12 forming the boom has a ball 20 mounted on its end. Tube 12 forms a coaxial conductor arrangement, with the metal boom forming the outer conductor, together with an inner, or central, conductor 22 and an intermediate insulating sleeve 23. First and second bearing members 24 and 25 are positioned in opposed relationship on the ball. First bearing member 24 is of electrically insulating material, for example nylon. Ball 20 and second bearing member 25 are of electrically conducting material. Extending from the second bearing member 25 is an annular housing 26. Housing 26, in the present example, is formed as part of the second bearing member 25, but can be a separate member attached to the bearing member. It is electrically conducting.
Housing 26 extends rearwards, away from the ball 20, and is a sliding fit in an annular extension 27 at the support housing 11. Rearwards of the extension 27 the support housing 11 has a tick web 28 and in a bore in the web 28 is positioned an electrically conducting sleeve 29. Sleeve 29 has a forward facing abutment surface 30, facing towards the annular housing 26.
Situated within the annular housing 26, and extending between the abutment surface 30 and the second bearing member 25, is a compression spring 31. Spring 31 acts to maintain the bearing member 25 in contact with the ball 20 and also maintains the ball 20 in contact with the first bearing member 24.
Within the sleeve 29 is an electrically insulating sleeve 32, and in the bore of the sleeve 32 is fixed an electrically conducting tube 33. Tube 33 acts as an electrically conducting means, as will be described later.
Positioned over the outside of the first bearing member 24 and annular extension 27 of the support housing 11 is a retaining member 35. As will be seen in FIG. 2, the front part of the bearing member 24 is of a conical shape, tapering inwardly toward the front end, at 36. The retaining member 35 is similarly shaped to engage with the tapered portion 36 of the bearing member. Positioned in a groove 37 formed in the support housing 11, at the position of the web 28, is a spring clip 38. Clip 38 has two outwardly extending pin-like projections 39 at approximately diametrically opposed positions. Two J-shaped slots 40 are formed in the rearward end of the retaining member 35. The slots 40 and projections 39 form a bayonet connection, to lock the retaining member in position.
To assemble a joint, the ball 20 is fixed on the end of the tube 12, the retaining member 35 and first bearing member 24 having first been positioned on the tube, or
boom 12. The inner conductor 22 extends from the ball and its end is given a crinkled formation as at 45. As the ball is brought into position against the second bearing member 25, the end of the central conductor enters the electrically conducting tube 33. The forward end of the insulating sleeve 23 is flared, at 46, to facilitate entry of the central conductor into the tube 33. The formation of the end of the conductor, at 45, ensured good contact with the tube 33, making an electrical connection. Once the ball 20 is in position, the retaining member is pushed over the annular extension 27 at the support housing 11 and locked in place by the J-slots 40 and projections 39.
An electrical connection is made at the other end of th sleeve 33, remote from the central conductor 20, by a conductor 47 which is inserted in the end of the sleeve.
There is a continuous electrical path through the joint, both for the central conductor via sleeve 33, and for the outer conductor via ball 20, second bearing member 25, spring 31 and sleeve 29. Also, the annular housing 26 extends almost to the forward end of the sleeve 29 and the spring 31 fills, to a substantial extent, any gap between housing 26 and sleeve 29, thus providing almost complete shielding.
The form of contact between the end of the central contact, at 45, and the tube 33, provides a very flexible connection and is not restrictive of the movement of the tube, or boom 12. The ball 20, mounted between the bearing members 24 and 25, provides easy movement of the tube, or boom, but at the same time, under the action of the spring 31, holds the tube, or boom, securely in a desired position. The forward part of the first bearing member 24 is tapered outwardly, at 48, to permit a satisfactory degree of movement of the tube, or boom 12.
The user is insulated from the current path for the outer conductor by the insulating sleeve 21 on the tube or boom 12, and by the electrically insulating nature of the first bearing member 24.
The boom assembly and mouthpiece 14, with the transducer, is readily separated from the support housing or structure 11.
Ball 20, second bearing member 25 with annular housing 26 and sleeve 29 are of any suitable electrically conducting material, conveniently metal. Other forms of locking the retaining member in position can readily be used.
FIG. 3 is a cross-section through another form of pivotal joint 13. The joint comprises a ball 20 of electrically conducting material. The ball 20 has an aperture therethrough by means of which it is mounted on the end of the metal boom 12. The boom forms a coaxial conductor arrangement, with the metal boom forming the outer conductor, with an outer insulating sleeve 21, an inner conductor 22 and an intermediate insulating sleeve 23. The ball 20 is held between first and second bearing members and 51, in opposed relationship on the ball. Both bearing members are of electrically insulating material. The first bearing member has a rearwardly extending tubular portion 52 which is attached to the housing 11, by pins 53.
Housing 11 has a forward facing abutment face 54 and a compression spring 55 extends between the abutment face 54 and the second bearing member 51. Spring 55 acts to push the second bearing member 51 against the ball 20 and to maintain engagement between the two bearing members 50 and 51 and the ball 20.
Extending axially, and supported partly within the housing 11, is an electrically conducting rod 56. Rod 56 acts as an electrical connector. The end of the metal boom 12 within the ball 20 fits over an insulating sleeve 57. Within the sleeve 57 is a metal pin 58 to which the inner conductor 22 is connected. Sleeve 57 has an enlarged end 59 which is a tight fit in the aperture in the ball 20 and the pin 58 also has an enlarged end 60. The forward end 61 of the rod 56 is in electrical conducting engagement with enlarged end 60 of pin 58. The rod 56 is slidably supported in the housing 11 and a compression spring 62 extends between an abutment surface 63 on the housing and an abutment 64 on the rod 56.
A tubular member 64 extends from the ball rearwards to the housing 11. The forward end of the member 65is in electrically conducting sliding contact with the ball 20, and the rearward end is supported by the housing 11, being between the extension 52, of the first bearing member 50, and the housing 11, and retained in position by the pins 53. The housing 1 1 has a sprayed metallic layer 66 which acts as an electrically conducting path, the layer 66 shown exagerated in thickness in FIG. 3 for clarity.
A coaxial conductor extends through the housing 1 1, the inner conductor 67 connected to the rearward end of the rod 56 as by being crimped and pushed into a hole in the rod 56, as shown in FIG. 3. The outer conductor 68 is connected to the housing to connect electrically with the layer 66, for example by a wire extending through the housing and connected to one of the pins 53, as indicated at 69. There is thus an electrically conductive path through the joint, for the inner conductor via the metal pin 58 and rod 56, while for the outer joint the path is via the ball 20, tubular member 65 and layer 66. Tubular member 64 acts with the layer 66, to electrically shield the inner conducting path.
FIG. 4 illustrates yet another form of pivotal joint 13. The joint comprises a ball 20 of electrically conducting material having an aperture therethrough for attachment of the metal boom 12. The boom 12 forms a coaxial conductor, the metal boom forming the outer conductor and having an outer insulating sleeve 21, an inner conductor 22 and an intermediate insulating sleeve 23.
The ball 20 is held between first and second bearing members 70 and 71. First bearing member 70 is of electrically insulating material, for example nylon, and second bearing member 71 is of electrically conducting material. The first bearing member has a rearwardly extending tubular extension 72 by which it is attached to the housing 11 by metal pins 73.
Second bearing member 71 also has a rearwardly extending tubular extension 74. Tubular extension 74 extends within the housing 11 and is axially slidable therein. An abutment 75 is formed in the housing 11 and another abutment 76 is formed on the tubular extension 74. A compression spring 77 extends between the abutments 75 and 76 and urges the second bearing member 71 towards the first bearing member 70.
Slidably supported within tubular extension 74 is an electrically conducting rod 78. Rod 78 is insulated from the extension 74 by an insulating sleeve 79. A compression spring 80 acts on an abutment 81 formed on the rod 78 and urges the rod towards the ball 20.
[n the ball 20, the metal boom 12 is a tight fit in the aperture formed in the ball. Within the boom 12 is an insulating sleeve 82 having an enlarged end portion 83. Within the sleeve 82 is an electrically conducting pin 84 having an enlarged head 85. The forward end of the rod 78 is in electrically conducting contact with the enlarged head 85 of the pin 84. At the rearward end of the joint connection is made to a coaxial conductor, the inner conductor 86 connected to the rod 78 by means of a crimped portion 87 filling in a hole 88 in the end of the rod 78. The outer conductor 89 is connected to the housing 11 which has a sprayed metallic conducting layer 86, for example by a wire 90 in the housing 11 which extends to the forward surface of abutment 75. Conveniently a metal washer 91 is positioned between the forward surface of abutment 75 and the rearward end of the spring 77. The forward end of spring 77 is in contact with abutment 76 on the tubular extension 74.
There is thus a continuous electrically conducting path for the inner conductor 86 via the pin 84 and rod 78, and for the outer conductor 89 via ball 20, second bearing member 71 and tubular extension 74, spring 77, washer 91 and layer 86, while also forming a shield for the inner conductor. A metal tube 87 may be positioned over the first bearing member 70 and extension 71.
The joint provides for the rotation of the boom, and also angular movement of the boom, when required, but at the same time holds the boom firmly in the required position. An electric current path is provided through the joint-avoiding the use of flexible conductors by-passing the jointand the current path is shielded. This enables a high impedance transducer to be used although it will be appreciated that joints in accordance with the present invention can be used in conjunction with other forms of transducers and also for other purposes, not using transducers, where it is advantageous to use a pivotal joint which conducts electrically through the joint.
What is claimed is:
1. An electrically conducting freely pivoting joint connecting first and second co-axial conductors, each co-axial conductor having an inner and an outer conductor, said joint comprising:
a spherical member of electrically conducting material, and having an aperture therethrough to receive said first co-axial conductor, the spherical member in electrical contact with the outer conductor of the first co-axial conductor,
a first bearing member acting on the spherical member on the side of entry of said first conductor into said spherical member;
a second bearing member acting on the spherical member in opposition to said first bearing member;
a spring acting on said second member and resiliently urging said bearing members and said spherical member into pivoting relationship;
a housing of electrically insulating material extending axially from said spherical member toward said second co-axial conductor;
axially extending relatively rotatable electrical connecting means supported in said housing and extending between the inner conductors of said first and second co-axial conductors;
a tubular electrically conducting member extending axially from the spherical member toward the second co-axial conductors and forming at least part of the electrically conducting path between the outer conductors of the co-axial conductors; and
tubular retaining means retaining the bearing members and spherical member in relative pivoting relationship in said housing.
2. A joint as claimed in claim 1, said tubular electrically conducting means comprising a tubular extension of the second bearing member.
3. A joint as claimed in claim 1, said tubular electrically conducting means comprising a tubular member surrounding said second bearing member and having a forward end in sliding contact with the periphery of the spherical member, the rearward end supported by said housing.
4. A joint as claimed in claim 1, the electrical connecting means comprising a tube supported in said housing, the inner conductor of said tubular member entering into the bore of the tube in sliding and rotatable relationship therewith.
5. A joint as claimed in claim 1, the electrical connecting means extending to the spherical member and contact means in said spherical member for connection to the inner conductor of said tubular member, the electrical connecting means in contact with said contact means.
6. A joint as claimed in claim 5, including an abutment on said electrical connecting means and a compression spring extending between said abutment and said housing to urge the electrical connecting means toward the spherical member.
7. A joint as claimed in claim 1, said spring extending between said second bearing member and said housing.
8. A joint as claimed in claim 1, said tubular retaining means comprising a member extending over and in contact with the first bearing member and secured to said housing.
9. A joint as claimed in claim 1, said tubular retaining means comprising a rearwardly extending tubular extension on said first bearing member, and pins extending through said tubular extension into said housing.
10. An electrically conducting freely pivotal joint connecting first and second co-axial conductors, the first co-axial conductor having a rigid tubular outer conductor and an inner flexible conductor, the second co-axial conductor comprising flexible inner and outer conductors, said joint comprising: an electrically conducting ball, the ball mounted on the rigid outer conductor of the first co-axial conductor in electrical contact therewith; a first bearing member of electrically insulating material, acting on the ball on the side of entry of the first co-axial conductor into the ball; a second member, of electrically conducting material, acting on the ball in opposition to the first bearing member; a support housing of electrically insulating mate rial; an annular extension on said housing extending in a direction toward said ball; an annular member extending from said second bearing member inside said annular extension on said housing; an electrically conducting sleeve in said support housing axially of said annular member and including an abutment surface facing towards said second bearing member; a compression spring extending between said abutment surface and said second bearing member within said annular housing, said spring resiliently urging said bearing members and said ball into pivoting relationship; axially extending tubular electrical conducting means lar outer conductor of the first coaxial conductor pass through the ball, the inner conductor connecting to the said tubular electrical conducting means, the ball, second bearing member, annular extension, spring and electrically conducting sleeve an electrically conducting and shielded path from the tubular member through the joint, the tubular member free to rotate and to pivot in any direction to a predetermined amountv