US 3319211 A
Description (OCR text may contain errors)
May 9, 1967 T, SWTH ETA; 3,319,211
I ELECTRICAL CONNECTOR Filed July 14, 1964 42 4 Fig.1. 1
Wafer M WilliomT Smith 8 Howard LBullJz ATTORNE'Y United States Patent 3,319,211 ELECTRICAL CONNECTOR William T. Smith, Linthicurn, and Howard L Bull, Jr.,
Pikesville, Md, assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa. a corporation of Pennsylvania Filed July 14, 1964, Ser. No. 382,470 7 Claims. (Cl. 339-31) This invention relates to electrical connectors and, more particularly, to those connectors capable of interconnecting coaxial conductors.
A typical coaxial conductor has an inner conductor surrounded by an insulating material which is bonded to the inner conductor; further, a woven shielding conductor is formed concentrically about the insulating material and an outer jacket of insulating material is placed about the shielding conductor. Coaxial conductors have been frequently utilized in the aerospace sciences, where there has arisen a need for environmentally sealed connectors for these conductors.
As is well known in the aerospace sciences, electrical apparatus and components must :be maintained in a specified environment within pressure vessels even though the pressure of the surrounding atmosphere may be drastically reduced. A primary cause of failure of apparatus within these pressure vessels is that the pressure of the environment within these vessels tends to escape because of inadequate sealing mechanisms. This problem has been especially critical where coaxial connectors have been incorporated into the walls of pressure vessels and subjected to reduced pressure. More specifically, as the pressure of the atmosphere Surrounding the enclosure is reduced, the pressure of the environment within the vessel tends to escape through minuscule passageways between the woven conductor and the inner insulating material, and those between the woven conductor and the outer jacket.
Essentially, the problems encountered in coaxial conductors are: (l) the sealing of the insulating material bonded to the inner conductor, and (2) terminating the woven shielding conductor in a manner so as not to interfere with the pressure seal abutting against the insulating material.
Many attempts to solve these problems have been offered by the prior art. Probably the most obvious solution would be to apply a potting material about the point of interconnection between the connector and the coaxial conduct-or. This solution has been found unsatisfactory for the following reasons: (1) the potting material requires considerable time to set; (2) the connector has to be tested to insure that the potting material has actually sealed properly; (3) the pressure of the environment still has a tendency to escape between the woven conductor and the inner and outer insulating material of the conductor, and (4) once a connector has been potted it is difiicult, if not impossible, to replace one coaxial conductor with another. Other solutions suggested the use of a complex series of overlapping flanges and sealing members; however, due to the complexity and the size of such connectors they would neither be suitable for multi-terminal connectors, nor would they provide the flexibility desired where there is a need for rewiring to the connector a new conductor.
In many applications involving the use of multi-terminal connectors, there exists the requirement that an additional number of terminals be provided so that "future alterations may be made. By providing additional terminal elements, the interconnection of components and circuit-ry with the connector may be easily modified. However, there exists the problem of providing additional terminal elements and yet maintaining the unused terminal elements with an environmental seal.
3,3 l9,2ll Patented May 9, 1967 It is, therefore, an object of this invention to provide an improved electrical connector.
A further object of this invention is to provide an improved coaxial connector.
Another object is to provide a multi-terminal connector which is characterized by its simplicity and compactness.
A further object of this invention is to provide an improved coaxial connector having terminals which are capable of being environmentally sealed and yet being easily interconnected with another conductor.
A still further object of this invention is to provide an improved multi-te-rminal connector having terminal elements adapted to receive dummy pin elements which are easily substituted for coaxial conductors and which may be environmentally sealed with the terminal elements.
A still further object of this invention is to provide an improved connector for a coaxial conductor having a mechanically strong means for terminating the shielding conductor, and yet, maintain an environmental seal between the shielding conductor and the insulating material of the coaxial conductor.
Stated briefly, the present invention describes a multiterminal, coaxial connector employing a resilient sealing member which is compressed to abut against the insulation material of the coaxial conductor and the terminal element to thereby insure an environmental seal and to prevent the escape of the pressure of the environment through minuscule passageways between the insulating material surrounding the inner conductor and the woven conductor of a coaxial conductor. Further, a grounding sleeve is employed about the insulating material to provide a surface to which the woven conductor may be electrically and mechanically secured and to provide an abutting surface to compress the resilient member against and to form a seal between the insulating material and the conductive terminal member.
A further aspect of this invention employs a spare pin element which may be easily inserted in the terminal element to compress the resilient sealing member and to form an effective environmental seal between the pin element and the terminal element.
Further objects and advantages of the invention will become apparent as the following description proceeds and features of novelty which characterize the invention will be pointed out in particularity in the claims annexed thereto and forming a part of the specification.
For a better understanding of the invention, reference may be made to the accompanying drawings, in which:
FIGURE 1 is a partially sectioned view of a multi-terminal electrical connector embodying this invention;
FIG. 2 is an enlarged, partial view of the terminal elements employed in the connector shown in FIG. 1; and
FIG. 3 is a view of the dummy pin element which may be employed in the electrical connector shown in FIG. 1.
Referring in detail to FIG. 1, a multi-terminal connector 10 is shown which embodies a plurality of terminal elements 40. More specifically, connector 10 comprises as outer shell or support member 14 having therein a cavity 16. Extending radially from the outer shell 14 is a flange 18 which has an annular groove 20 machined at the intersection of the flange 18 with the outer shell 14. To understand the nature of this invention, it is noted that the connector 10 forms an electrical conduit through a wall 12 of a pressure vessel (not shown) which is sealed to contain a determined environment. The connector 10 extends through an aperture 13 of the wall 12 and is secured thereto by a nut 26 which has been placed over threads 21 machined into the outer shell 14. A resilient gasket 22 has been placed within the groove 20 and is compressed against the wall 12 to insure an environmental seal betweenthe outer shell 14 of the connector 10 and the wall 12.
A plurality of terminal elements 40 made of an electrically conductive material such as aluminum or brass have been suspended within the cavity 16 of the connector by a potting material or sealing means. Each of the terminal elements 40 have a plurality of teeth 42 which insure sealing between the terminal element 40 and the potting material 24. The terminal elements 40 (as shown in FIG. 1) are connected to a coaxial conductor 66 and are secured thereto (as will be explained later in detail) by a threaded cap or means for urging 44 which is made of an electrically conductive material such as aluminum or brass. Further, a grommet 28 made of a yieldable, moisture resistant, insulating material is inserted within the cavity 16 of the connector 10. The yieldable grommet 28 has a plurality of openings 30 through which the coaxial conductors 60 extend and are yieldably held to prevent undue mechanical stress being placed upon the coaxial conductors 60 at their point of interconnection with the terminal element 40. In addition, the yieldable grommet 28 is provided with a joining ring 32 which has been placed concentrically about the inner end of the grommet 28 to provide a surface against which a retaining ring 34 may abut; the retaining ring 34 has been inserted within the cavity 16 and held therein by threads 36 to secure the retaining ring 34 and the yieldable grommet 28.
Referring now to FIGURE 2, there is shown a more detailed view of the terminal elements 40 and their inner connection with the coaxial conductor 60. Each of the terminal elements 40 has a passageway 41 formed axially through the element 40. A sleeve 46 made of a durable, insulating material such as Teflon (a trademark for the plastic polymer, tetrafluoroethylene) is inserted within the passageway 41. The insulating sleeve 46 has an opening 47 disposed centrally therethrough into which has been inserted a hollow, cylindrical contact 48 made of an appropriate conductive material such as brass.
An inner conductor 62 of the coaxial conductor 60 is connected to the cylindrical contact 48 by a process such as by soldering. The coaxial conductor 60 consists of the inner conductor 62 about which is bonded an insulating material 64 made of a durable and heat resistant material such as Teflon. Further, a shielding conductor 66 is woven about the insulation 64 and an outer jacket 68 of an appropriate insulating material is placed concentrically about the shielding conductor 66.
As mentioned above, one of the primary problems which this invention seeks to solve is the prevention of the pressure of the environment within the pressure vessel from escaping through the connector 10 and more specifically through the passageways formed between the insulating material 64 and the shielding conductors 66 and between the shielding conductor 66 and the outer jacket 68. A simple yet effective solution for this problem is presented by using an annular resilient member 52 which is compressed to form an effective seal between the terminal element 40 and the insulating material 64 of the coaxial conductor 60. In one particular embodiment, the resilient member 52 is an O-ring made of neoprene; however other resilient, non-porous materials capable of forming a tight seal could be used. Further, it is noted that harder materials such as metallic elements would be ineffective. First, a metallic element could not form a tight seal with an insulating material 64 such as Teflon, because of the malleable or depressable characteristic of such material. Secondly, a metallic element could not form a seal with the hard surfaces of the terminal element 40 or a sleeve 50. The cylindrical grounding sleeve or member 50 is placed about the insulating material 64 to press an abutting flange or portion 51 of the sleeve 50 against the O-ring 52. A beveled surface is machined at the end of the passageway 41. Further, the threaded cap 44 is positioned about the grounding sleeve and is secured to the terminal element 40 by threads 49, which allow the cap 44 to be screwed onto the terminal element 40 so as to apply a gradual, uniform pressure against the O-ring 52. The pressure exerted by the grounding sleeve 50 compresses the O-ring 52 to abut tightly against the beveled surface 45 of the terminal element 40 and the insulating material 64 of the coaxial conductor 60. More specifically, the non-porous material of the O-ring 52 is held in compression between these two surfaces to insure a tight environmental seal between the terminal element 40 and the coaxial conductor 66. Thus there has been disclosed a sealing mechanism which prevents the escape of a fluid environment through the passageways through and about the woven conductor 66 and also through the minuscule spaces formed by inherent irregularities in the surfaces of the cap 44 and the grounding sleeve 50 when they are placed in position.
As indicated above, an object of this invention is to provide a termination for the shielding conductor 66 which is both mechanically strong and which provides an effective seal. The grounding sleeve 56 is coated first with a layer of silver approximately 0.3 mils thick and then is flashed with a thin layer of gold or other suitably conductive material to provide a surface to which the shielding conductor 66 may be easily soldered. By this construction the shielding conductor 66 is firmly secured to the grounding sleeve 50 and the shielding conductor 66 is terminated in a means which i readily environmentally sealed.
Further, it is noted that another coaxial conductor 60 may easily replace one that has originally been inserted within the terminal element 46. By simply unscrewing the cap 44 from the terminal element 40, the coaxial conductor 66 may be withdrawn. A new coaxial conductor 60 may be readily adapted to be inserted within the terminal element 40 by removing a portion of the insulation 64 and by soldering a cylindrical contact 48 to the bored portion of the inner conductor 62; then, a grounding sleeve 50 may be soldered to the shielding conductor 66 which ha been placed beneath the shielding conductor 66. Finally, the O-ring 52 is placed about the insulation 64 so as to abut the flange 51 of the grounding sleeve 56, and the cap 44 is screwed onto the threads 49 to uniformly compress the flange 51 against the O-ring 52 to achieve the desired environmental seal.
As shown in FIG. 2 and FIG. 3, a dummy pin element 70 is provided to insure a seal for those additional terminal elements 40 which allow for further modification of the connector 10. The dummy pin element 70 consists of an extended portion 76 which is axially aligned of a minor or retaining portion 74 and an abutting or flange portion 72 which extends radially therefrom. As shown in FIG. 2, when a particular terminal element 40 is not interconnected with a coaxial conductor 60, the dummy pin element 76 is inserted within the terminal element 40 to provide a seal. More specifically, the O- ring 52 is placed about the minor portion 74 and the cap 44 is placed about the extended portion 70; the cap 44 i then threaded onto the terminal element 40 to urge the abutting flange 72 against the O-ring 52 and thereby compress O-ring 52 to insure an environmental seal between the beveled surface 45 and the minor portion 74.
Therefore it may be seen that a multi-terminal connector has been disclosed which achieves an environmental seal for a coaxial conductor employing a simple arrangement of the minimum number of elements. More specificially, the shielding conductor has been terminated securedly with a sleeve-like member having a surface to compress a resilient member between the insulation of the coaxial conductor and a portion of the terminal element. An obvious advantage of this connector, is that it may be easily modified and new coaxial conductors be interconnected therewith; further, there is provided a dummy pin element which may be inserted within those additional terminal elements which are provided to insure the adaptability of this connector to further circuit modifications.
While there has been shown and described at present what is considered to be a preferred embodiment of the invention, modifications thereto readily occur to those skilled in the art. It is not desired, therefore, that the invention be limited to the specific arrangements shown and described and it is intended to cover in the appended claims all such modifications as followed in the true scope of the invention.
We claim as our invention:
1. An environmentally sealed connector for a coaxial cable having a first conductor, a second conductor disposed about said first conductor and a layer of insulating material disposed therebetween; said connector including a terminal element having an opening therethrough, a grounding member disposed about said layer of insulating material and connected to said second conductor, an annular shaped resilient member disposed about said layer of insulating material, said grounding member having a flange for abutting against said resilient member, an insulating sleeve disposed within said opening of said terminal element, a contact element adapted to receive said first conductor disposed within said insulating sleeve, and means for urging said flange of said grounding member against said resilient member to compress said resilient member against said terminal element and against said layer of insulating material thereby forming an environmental seal therebetween.
2. A multi-terminal, environmentally sealed connector for coaxial conductors having a first conductor, a second conductor disposed about said first conductor, and a layer of insulating material disposed therebetween; said connector comprising a tubular housing; a plurality of terminal elements supported within said housing by a sealing medium and having an opening therethrough, each of said terminal elements having an insulating sleeve disposed within said opening, and an electrical contact disposed within said insulating sleeve to receive said first conductor; resilient members disposed at one end of said terminal elements and about said openings of said terminal elements; a dummy pin having a flange portion for abutting against said resilient member and a projecting portion about which said resilient member is disposed; a grounding member for receiving said second conductor, said grounding member having a flange portion for abutting against said resilient member; and means for urging said flange portion of said grounding member and said abutting portion of said dummy pin against said resilient members for elfecting a seal between said dummy pin and one of said terminal elements and between said grounding member and one of said terminal elements.
3. A multi-terminal, environmentally sealed connector for coaxial conductors having a first conduct-or, a second conductor disposed about said first conductor, insulating material disposed between said first and second conductors, and a grounding member being connected to said second conductor and having a flange portion; said connector comprising a tubular support housing; a plurality of terminal elements supported within said housing by a sealing medium, said terminal elements having openings therethrough; a plurality of annular resilient members disposed about said openings of said terminal elements; a dummy pin having an abutting portion and a projection portion for receiving said resilient member; and means for urging said abutting portion of said dummy pin against one of said resilient members and for urging said flange portion of said grounding member against one of said resilient members to thereby form respectively an efiective seal between said dummy pin and one of said terminal elements and an effective seal between said grounding member and one of said terminal elements.
4. A multi-terminal connector for coaxial conductors having a first conductor and a second conductor disposed about said first conductor with an insulating material placed between said first and second conductors, said connector comprising a tubular support member, a plurality of terminal elements positioned within said support member and embodied in a sealing material disposed between said elements and said support member, each of said terminal elements having a passageway with a first and second end disposed on either side of said sealing medium, an insulating sleeve disposed within the first end of said passageway, a contact element for receiving said first conductor disposed within said insulating sleeve, the second end of said passageway having a beveled surface to receive a resilient member, a grounding sleeve for receiving said second conductor having an abutting portion disposed against said resilient member, and a means disposed about said grounding sleeve for urging said abutting portion against said resilient member, said resilient member being compressed to form a seal between said beveled surface and said insulating material.
5. A multi-terminal connector for coaxial conductors having a first conductor and a second conductor disposed about said first conductor with an insulating material placed between said first and second conductors, said connector comprising a tubular support member, a plurality of electrically conductive terminal elements sealed within said support member by a potting material, a resilient member, said terminal elements having a beveled surface, a grounding sleeve to receive said second conductor and having a radially extending flange, and a cap 'made of an electrically conductive material to urge said flange against said resilient member, said resilient member being compressed by said flange to abut against and to form a seal between said insulating material and said beveled surface.
6. A multi-terminal connector for a coaxial connector substantially as claimed in claim 5 wherein said cap is threaded to be secured to said terminal elements and to apply a gradual, uniform pressure against said flange.
7. A multi-terminal connector for coaxial conductors having a first conductor and a second conductor concentrically disposed about said first conductor with an insulating material placed between said first and second conductors, said connector comprising a tubular support member, first and second terminal elements, means for sealing said terminal elements within said support member, a grounding sleeve to receive said second conductor and having an abutting portion, first and second resilient members, a first means positioned about said coaxial conductor for urging said abutting portion against said first resilient member, said first resilient member being deformed to abut against said insulating material and said first terminal element, a dummy pin element having an abutting member and a retaining member, and a second means disposed about said dummy pin element to urge said abutting member against said second resilient member, said second resilient member being deformed to abut against said retaining member and against said second terminal element, said dummy plug being of such configuration and dimension to be substituted for said coaxial conductor upon said first terminal element to compress said first resilient member and to achieve a seal between said retaining member and said first terminal element.
. References Cited by the Examiner UNITED STATES PATENTS 1,969,529 8/1934 Shafer 339--218 X 1,969,866 8/1934 Wild et 'al. 339-89 1,996,422 4/1935 Hurley 33994 X 2,038,353 4/1936 Gardner et al 339143 X 2,047,031 7/1936 Paulson 339143 2,149,137 2/1939 Gardner 339143 2,410,098 10/ 1946 Muller 339126 2,552,686 5/1951 Melcher 339 X 2,557,818 6/1951 Eddy 339-31 3,079,580 2/1963 Paasche 3392=18 X EDWARD C. ALLEN, Primary Examiner.
PATRICK A. CLIFFORD, Examiner.