Co-axial Connector Including Positive Clamping Features For Providing Reliable Electrical Connections To The Center And Outer Conductors Of A Co-axial Cable

Abstract

This disclosure relates to a co-axial connector assembly especially adapted to provide electrical contact to both the center and outer conductors of a co-axial cable. The connector assembly employs a clamping arrangement for both the outer and center conductors of the co-axial cable which utilizes spring tension in order to follow "cold flow" changes and maintain good electrical connection to both the outer and center conductors of the co-axial cable.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to electrical connectors and, more particularly, to co-axial connector assemblies for use in providing good electrical contact to both the center and outer conductors of a co-axial cable.

2. Description of the Prior Art

Various types of co-axial connector assemblies have been developed in the past to provide electrical contact to both the center and outer conductors of a co-axial cable. With the advent of the use of aluminum as a replacement for copper for the center and outer conductors of a co-axial cable, significant advantages were realized due to the lightness and non-oxidizing qualities of the aluminum material relative to the heavier weight and higher rate of oxidation exhibited by copper. Other inherent advantages were also provided by the substitution of aluminum for copper as the center and outer conductors of co-axial cables.

A problem that is associated with the use of aluminum is the fact that this material exhibits "cold flow" properties which are deemed undesirable because of the difficulties in achieving a good electrical contact thereto.

The term "cold flow" is a term of the art that is used to indicate that a material such as aluminum will change its configuration after exposure to heat, cold, pressure and other environmental conditions, which make it difficult to obtain a good electrical contact to the material. One example of this is the fact that an aluminum conductor that is gripped by an electrical connector will, after a period of time, exhibit a compression or "cold flow" in the region of the pressure of the electrical connector on the aluminum conductor, which causes the aluminum material to flow away from the contact with the connector and thus results in a poor electrical contact between the connector and the aluminum conductor.

With the recognition of this problem, a number of different technical solutions have been proposed to provide a reliable clamping action on the center and outer aluminum conductors of a co-axial cable. However, the prior art solutions to this problem did not result in the production of a reliable electrical connector that could continue to make good electrical contact to the center and outer conductors of a co-axial cable regardless of the "cold flow" phenomena.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide an improved electrical connector.

It is a further object of this invention to provide an improved electrical connector for use in making electrical contact to both the center and outer conductors of a co-axial cable.

It is still another object of this invention to provide an electrical connector which has clamping features that can result in reliable and continuous electrical contact between the electrical connector and the center and outer conductors of a co-axial cable.

It is a still further object of this invention to provide an electrical connector which has clamping features to overcome the "cold flow" characteristics of aluminum conductors.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with one embodiment of this invention, a co-axial connector assembly is provided which is especially adapted to achieve electrical contact to both the center and outer conductors of a co-axial cable. The co-axial connector assembly contains center conductor gripping means applying continuous, positive gripping action to the center conductor of the co-axial cable. Outer conductor gripping means are provided as part of the co-axial cable assembly for both applying continuous, positive gripping action to the outer conductor of a co-axial cable and actuating the center conductor gripping means into gripping the center conductor. The co-axial connector assembly also includes actuating means for causing the outer conductor gripping means to perform the operations of gripping the outer conductor and actuating the center conductor gripping means into gripping the center conductor.

In accordance with another embodiment of this invention, a combination co-axial connector assembly and co-axial cable is provided. The co-axial cable contains both a center conductor and an outer conductor, which is preferably tubular in configuration. The co-axial assembly comprises center conductor gripping means for applying continuous, positive gripping action to the center conductor of the co-axial cable. Outer conductor gripping means are provided as part of the co-axial cable assembly for both applying continuous, positive gripping action to the outer conductor of a co-axial cable and actuating the center conductor gripping means into gripping the center conductor. The co-axial connector assembly also includes actuating means for causing the outer conductor gripping means to perform the operations of gripping the outer conductor and actuating the center conductor gripping means into gripping the center conductor.

The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side elevational view, in cross-section, showing the open position of the co-axial connector assembly of this invention prior to clamping action on the center and outer conductors of a co-axial cable.

FIG. 2 is a view similar to FIG. 1 showing the co-axial connector assembly in a closed position which results in the clamping of the outer conductor and center conductor of a co-axial cable.

FIG. 3 is a view similar to FIG. 1 showing an electrical connector assembly in an open position prior to clamping only the outer conductor of a co-axial cable. However, no clamping action and the features therefor for clamping the center conductor are shown.

FIG. 4 is a view similar to FIG. 3 with the co-axial connector assembly shown in the closed or clamping position.

FIG. 5 is an elevational, cross-sectional view similar to FIG. 1 showing two connector assemblies located within a single connector housing for splicing together two co-axial cables, both of the connector assemblies are in clamping positions wherein the two connectors are connected up together to permit the center and outer conductors of one co-axial cable to be electrically connected to the center and outer conductors of another co-axial cable.

Referring to FIG. 1, a co-axial connector assembly is generally shown by reference numeral 10. The connector assembly comprises preferably a hexagonal shaped nut 12 threadably connected by means of threads 14 to threads 16 of a connector body 18. The hexagonal nut 12 contains an annular groove 20 within which is located an 0-ring 22, which is preferably made of a flexible material such as rubber. The threads 14 and 16 of the hexagonal nut 12 and the connector body 18 serve to permit the hexagonal nut 12 to move to the left or right, as desired. The hexagonal nut 12 is provided with an annular actuating member 24 which contains a flat surface portion 26 that serves to contact a flat surface 28 of a ring 30, thereby causing the ring 30 to move in a direction to the right as viewed in FIG. 1. An annular rubber gasket 32 is located adjacent to the ring 30 and serves to resiliently urge the ring 30 to move to the left as viewed in FIG. 1 when the annular actuating member 24 is out of contact with the ring 30. A metal sealing ring 34 is provided adjacent to the annular rubber gasket 32 and serves as a mechanical stop therefor as shown in FIG. 1. The annular rubber gasket 32 fits within the slot in the metal sealing ring 34 defined by the surfaces 36 and 38.

The metal sealing ring 34 contains a groove 40 within which is located a O-type sealing ring 42 preferably made of rubber or some other suitable flexible material. The metal sealing ring 34 contains a beveled actuating portion 44 which serves to actuate clamping member 46. The clamping member 46 contains an extended annular stop 48 which functions to contact a stop 50 located within the connector body 18. Thus, the clamping member 46 can only be moved to the right as viewed in the Figure to the extent permitted before contact is made between the stops 48 and 50. The clamping member 46 is moved to the right by means of contact with the metal sealing ring 34.

The clamping member 46 contains internal threads 52 and an arm portion 54. The clamping member 46 also contains a beveled actuating portion 56 which is used to actuate and compress a dielectric, mushroom-shaped member 58. The dielectric member 58 is caused to compress because of the contact between the beveled actuating portion 56 and top surface 60 of the dielectric mushroom-shaped member 58. The dielectric mushroom-shaped member 58 contains a hollowed out annular portion 62 which surrounds a portion of clamping member 64. The clamping member 64 is used for the purpose of clamping a center conductor of a co-axial cable. The dielectric mushroom-shaped member 58 contains a beveled surface portion 66 which serves to engage a corresponding beveled surface portion 68 of the clamping member 64. Thus, when the dielectric mushroom-shaped member 58 is moved to the right, as viewed in FIG. 1, the beveled surface portion 66 of the dielectric mushroom-shaped member 58 contacts the beveled surface portion 68 of the clamping member 64 and serves to compress the clamping member 64 into clamping action on a center conductor of a co-axial cable.

The clamping member 64 is shown located within a dielectric plug 70. The dielectric plug 70 is located within an end portion 72 of the connector body 18. The end portion 72 of the connector body 18 contains threads 74 which serve to provide the connection to another connector or other type of device, as desired. 0-ring 76 is mounted about the end portion 72 between the threads 74 and a surface 78.

Referring to FIG. 2, all of the reference numerals used in FIG. 1 are repeated in FIG. 2 which illustrates the co-axial connector assembly in a closed or clamping position. A co-axial cable is shown both in FIGS. 1 and 2 and is generally designated by reference numeral 80. The co-axial cable 80 contains an outer dielectric casing 82 and an outer metal conductor 84. The outer dielectric casing 82 is shown stripped away from the outer metal conductor 84 within the portion of the connector assembly 10 that contains the ring 30, the annular rubber gasket 32, the metal sealing ring 34, and the clamping member 46. The clamping member 46 contains slots, one of which is shown by the dotted line outline 86. These slots permit the arm portion 54 of the clamping member 46 to be compressed inwardly as shown in FIG. 2 when the beveled actuating portion 44 of the metal sealing ring 34 engages the beveled surface of the arm portion 54 as shown in FIG. 2. Similarly, the clamping member 64 is also provided with slots, one of which is shown by a dotted outline 88 in order to permit the clamping member 64 to be compressed into firm clamping action about center conductor 90 of the co-axial cable 80. The center conductor 90 of the co-axial cable 80 penetrates through the dielectric mushroom-shaped member 58 and into the bore provided within the clamping member 64.

OPERATION OF CONNECTOR

The connector assembly 10 is shown in the open position in FIG. 1 and in the closed or gripping position in FIG. 2. In the open position shown in FIG. 1, the hexagonal nut 12 is in a raised position with respect to the connector body 18. Upon the turning of the nut 12 in a clockwise direction, the hexagonal nut 12 is moved to the right until annular flange 92 of the hexagonal nut 12 contacts annular stop 94 of the connector body 18. This position is shown in FIG. 2. As a result of this movement of the hexagonal nut 12, the annular actuating member 24 thereof contacts and urges the ring 30 to move to the right as viewed in FIGS. 1 or 2. This serves to compress the annular rubber gasket 32 which causes the metal sealing ring 34 to also move to the right thereby contacting the arm portion 54 of the clamping member 46. Because of the beveled actuating portion 44 of the metal sealing ring 34, the arm portion 54 of the clamping member 46 is compressed inwardly towards contact with the outer metal conductor 84. The internal threads 52 of the clamping member 46 provide positive gripping action of the outer metal conductor 84 and this gripping action is maintained even under "cold flow" conditions of the metal conductor. Hence, the gripping or clamping action of the clamping member 46 is continuous and provides a good electrical contact to the outer metal conductor 84 of the co-axial cable 80. The beveled actuating portion 56 of the clamping member 46 contacts and compresses the dielectric mushroom-shaped member 58 when the hexagonal nut 12 is in its closed or contact position with the connector body 18. Since the clamping member 46 is moved to the right, as viewed in FIGS. 1 or 2, the dielectric mushroom-shaped member 58 is also urged to the right besides being compressed by the beveled actuating portion 56 of the clamping member 46. This results in having the beveled surface portion 66 of the dielectric mushroom-shaped member 58 engaging the beveled surface portion 68 of the clamping member 64. As a result, the clamping member 64 is compressed and provides a good electrical contact to the center conductor 90 of the co-axial cable 80.

Referring to FIGS. 3 and 4, these Figures illustrate a connector assembly similar to the connector assembly of FIGS. 1 and 2, with the exception that the connector assembly of FIGS. 3 and 4 is directed to making electrical contact to only the outer conductor of a co-axial cable. Accordingly, the same reference numerals used in FIGS. 1 and 2 are repeated in FIGS. 3 and 4. FIG. 3 represents the connector assembly in an open position where clamping or gripping action is not made of the outer conductor. FIG. 4 represents the connector assembly in a closed position where clamping action is made to the outer conductor of the co-axial cable. The center conductor 90 is not gripped in this Figure and penetrates through a dielectric plug 70A having an aperture 71 for the passage of the center conductor 90 therethrough.

Referring to FIG. 5, the reference numerals used in FIGS. 1 and 2 are repeated again in FIG. 5 to show the same elements. In FIG. 5, two co-axial cables 80A and 80B are shown electrically connected together in the manner described with respect to FIG. 1. In this embodiment, two dielectric mushroom-shaped members 58A and 58B are utilized in a manner described with respect to the dielectric mushroom-shaped member 58 of FIGS. 1 and 2. Thus, clamping action is achieved at both ends of the single clamping member 64 to the center conductors 90A and 90B of the co-axial cables 80A and 80B respectively.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention. The co-axial connector of this invention is particularly useful in providing means for achieving a spring loading effect on both the center and outer conductors to permit continuous electrical contact to be made despite the "cold flow" aspects of the metal conductors. This spring loading effect on the center conductor is achieved by the compression of the mushroom-shaped dielectric member 58 because of the force exerted thereon by the beveled actuating portion 56 of the clamping member 46. The hollow, annular, inner portion of the mushroom-shaped dielectric member 58 exerts a radial force on the metal clamping member 64 which serves to follow and maintain physical and electrical contact to the center conductor 90 despite "cold flow" effects. A spring loading effect is achieved on the metal outer conductor 84 by the clamping member 46. This spring loading effect is achieved by the bowing of the arm portion 54 due to the action of the beveled actuating portion 44 of the metal sealing ring 34. This bowing causes the internal threads 52 of the clamping member to continuously grip the outer conductor 84 despite any "cold flow" characteristics exhibited by the metal of the outer conductor 84. Additionally, another major advantage of the design of the connector of this invention is that both the center and outer conductors of a co-axial cable can be securely gripped despite any forces accidental or otherwise tending to extract or remove the co-axial cable from the connector. For example, a force on the center conductor 90 which would tend to pull this conductor to the left (as viewed while looking at FIG. 1) does not succeed in extracting this conductor from this connector due to the immediate contact and engagement of the tapered portions 66 and 68 of the mushroom-shaped member 58 and the clamping member 64, respectively which causes even greater gripping action to occur on the center conductor 90. The tapered surface 44 and the corresponding tapered surface on the clamping member 46 work in the same way as the previously described tapered surfaces with respect to the center conductor and thus, the outer conductor 84 is even more firmly gripped due to greater contact by the threads 52 when an extraction force is applied to the outer conductor 84.

Claims

We claim:

1. A co-axial connector assembly especially adapted to provide electrical contact to both the center and outer conductor of a co-axial cable comprising, in combination,

center conductor gripping means for applying continuous, positive gripping action to the center conductor of a co-axial cable; dielectric spring means including gripping means for transmitting an inward force to the center conductor gripping means in response to axial movement and a radially extending, flexible flange for axially biasing said camming portion into engagement with said center conductor gripping means despite cold flow effects exhibited by said center conductor;

outer conductor gripping means for both applying continuous, positive gripping action to the outer conductor of a co-axial cable and for deforming said radially extending flexible flange to thereby actuate said center conductor gripping means into gripping said center conductor, said outer conductor gripping means comprising a hollow, tubular shaped member having flexible first end means for contracting inwardly into engagement with the outer conductor of said co-axial cable, and

actuating means for causing said flexible first end means of said outer conductor gripping means to apply a continuous inward, spring-loaded force on said outer conductor to maintain continuous electrical contact with said outer conductor despite cold flow effects exhibited by said outer conductor.

2. A co-axial connector assembly in accordance with claim 1 wherein said dielectric spring means comprising a dielectric mushroom-shaped member.

3. A co-axial connector assembly in accordance with claim 1 wherein said flexible first end means of said outer conductor gripping means comprising a slotted, annular ring.

4. A co-axial connector assembly in accordance with claim 2 wherein said flexible first end means of said outer conductor gripping means comprising a slotted, annular ring.

5. A co-axial connector assembly in accordance with claim 1 wherein said center conductor gripping means having means for preventing said center conductor from being pulled out of said co-axial connector and for increasing the gripping action on said center conductor during extraction of said center conductor from said co-axial connector assembly, said flexible first end means of said outer conductor gripping means having means located thereon for causing said flexible first end means to contract inwardly into engagement with the outer conductor of said co-axial cable if a force is applied to extract said outer conductor from said co-axial conductor assembly.

6. A co-axial connector assembly in accordance with claim 4 wherein said center conductor gripping means having means for preventing said center conductor from being pulled out of said co-axial connector and for increasing the gripping action on said center conductor during extraction of said center conductor from said co-axial connector assemblies, said flexible first end means of said outer conductor gripping means having means located thereon for causing said flexible first end means to contract inwardly into engagement with the outer conductors of said co-axial cable if a force is applied to extract said outer conductor from said co-axial conductor assembly.

7. A co-axial connector assembly especially adapted to provide electrical contact to both the center and outer conductors of two co-axial cables comprising, in combination,

a first center conductor gripping means for applying continuous, positive gripping action to a first center conductor of a first co-axial cable, first dielectric spring means including a first camming portion contacting said first center conductor gripping means for transmitting an inward force to the first center conductor gripping means in response to axial movement and a first radially extending, flexible flange for axially biasing said first camming portion into engagement with said first center conductor gripping means despite cold flow effects exhibited by said first center conductor; a first outer conductor gripping means for applying continuous, positive gripping action to a first outer conductor of said first co-axial cable and for deforming said first radially extending flange to thereby actuate said first center conductor gripping means into gripping said first center conductor, said first outer conductor gripping means comprising a hollow, tubular shaped member having flexible first end means for contracting inwardly into engagement with said first outer conductor of said first co-axial cable, first actuating means for causing said flexible first end means of said first outer conductor gripping means to apply a continuous inward, spring-loaded force on said first outer conductor to maintain continuous electrical contact with said first outer conductor despite cold flow effects exhibited by said first outer conductor,

a second center conductor gripping means for applying continuous, positive gripping action to a second center conductor of a second co-axial cable, second dielectric spring means including a second camming portion contacting said second center conductor gripping means for transmitting an inward force to the second center conductor gripping means in response to axial movement and a second radially extending, flexible flange for axially biasing said second camming portion into engagement with said second center conductor gripping means despite cold flow effects exhibited by said second center conductor; a second outer conductor gripping means for applying continuous, positive gripping action to a second outer conductor of said second co-axial cable for deforming said second radially extending flange to thereby actuate said second center conductor gripping means into gripping said second center conductor, said second outer conductor gripping means comprising a hollow, tubular shaped member having flexible first end means for contracting inwardly into engagement with said second outer conductor of said second co-axial cable, second actuating means for causing said flexible first end means of said second outer conductor gripping means to apply a continuous inward, spring-loaded force on said second outer conductor to maintain continuous electrical contact with said second outer conductor despite cold flow effects exhibited by said second outer conductor.

8. A co-axial connector assembly in accordance with claim 7 wherein said first and second dielectric spring means comprising a dielectric mushroom-shaped member.

9. A co-axial connector assembly in accordance with claim 7 wherein said flexible first end means of said first and second outer conductor gripping means comprising a slotted, annular ring.

10. A co-axial connector assembly in accordance with claim 8 wherein said flexible first end means of said first and second outer conductor gripping means comprising a slotted, annular ring.

11. A co-axial connector assembly in accordance with claim 7 wherein said first and second center conductor gripping means having means for preventing said center conductors from being pulled out of said co-axial connector assembly and for increasing the gripping action on said center conductors during extraction of said center conductors from said co-axial connector assembly, said flexible first end means of said first and second outer conductor gripping means having means located thereon for causing said flexible first end means to contract inwardly into engagement with the outer conductors of said co-axial cables if a force is applied to extract said outer conductors from said co-axial conductor assembly.

12. A co-axial connector assembly in accordance with claim 10 wherein said first and second flexible dielectric spring means having means cooperatively associated with said center conductor gripping means for preventing said center conductors from being pulled out of said co-axial connector and for increasing the gripping action on said center conductors during extraction of said center conductors from said co-axial connector assemblies, said flexible first end means of said outer conductor gripping means having means located at one end thereof for causing said flexible first end means to contract inwardly into engagement with the outer conductors of said co-axial cable if a force is applied to extract said outer conductors from said co-axial conductor assemblies.