Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
  • H01R13/46—Bases; Cases
  • H01R13/52—Dustproof, splashproof, drip-proof, waterproof, or flameproof cases
  • H01R13/5202—Sealing means between parts of housing or between housing part and a wall, e.g. sealing rings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R9/00—Structural associations of a plurality of mutually-insulated electrical connecting elements, e.g. terminal strips or terminal blocks; Terminals or binding posts mounted upon a base or in a case; Bases therefor
  • H01R9/03—Connectors arranged to contact a plurality of the conductors of a multiconductor cable, e.g. tapping connections
  • H01R9/05—Connectors arranged to contact a plurality of the conductors of a multiconductor cable, e.g. tapping connections for coaxial cables

Definitions

• This invention relates generally to a connector for coaxial cable, such as the type used for cable TV transmission.
• Coaxial cable connectors that require crimping are associated with certain disadvantages. Crimping tools tend to wear out with repeated use, and crimping does not provide a satisfactory seal. A number of crimpless connectors have been developed which attempt to overcome these problems.
• One type of crimpless connector receives a compression sleeve, which is first broken away from a plastic ring mounted on the connector, and then slid over the cable and finally inserted into the annular cavity between the inner wall of the connector and the jacket of the cable. A tool is used to push the compression sleeve fully into the connector with a snap engagement.
• a problem with this connector is that it can be awkward to break the compression sleeve away from the connector and then thread it onto the cable, particularly when used in field installations where there may be adverse weather conditions.
• the compression sleeve can as well be inadvertently threaded onto the cable backwards, and it can also be dropped and lost.
• An alternative crimpless connector has more recently been provided, which permits the cable to be secured to it simply by pushing the cable into the connector and subsequently pulling it back.
• the body of this "push-pull" connector has a bushing mounted within it near the cable receiving end having a diameter to closely receive the cable.
• the body of the connector also has within it an annular mandril having a bore to receive the stripped core of the cable, and having a sleeve adapted to engage the cable beneath the jacket by pushing the cable and the mandril together. This stretches the jacket of the cable to a diameter greater than the internal diameter of the bushing
• the mandril is moveable from a position in which the sleeve is surrounded by the bushing in which the sleeve may be engaged to the cable, to a position in which the sleeve is at least partially within the bushing in which the jacket is frictionally engaged by the bushing by pulling the cable away from the connector after it has been pushed onto the mandril sleeve.
• the push-pull cable connector has many advantages, it does not lend itself to all applications. In some publicly accessible installations, for example, it is the usual practice to cover the threaded posts to which the cables are connected by a security ring, making the threaded portion of an installed cable connector inaccessible to finger manipulation or common wrenches or pliers. Unauthorized removal of the cable is thereby discouraged as a special tool is needed to fit within the security ring. Due to the close tolerances of the standard security ring, the dimensional limitations of the push-pull connector present a significant obstacle. The internal bushing and mandril of the push-pull connector require a larger body diameter than can be accommodated in the standard sized security ring. While a larger security ring could be substituted, doing so would present additional costs.
• the push-pull connector can be awkward to use with coaxial cable having multiple layers of braided shielding. Because of the limited travel of the mandril and bushing, the inserted cable must be trimmed to expose only a short distance of braided shielding. Folding back one layer of braided shielding presents little difficulty. However, manipulating multiple layers of braided shielding that are as short as required can be awkward. While a push-pull connector could be made with a longer travel for the mandril and bushing, thus allowing a longer trimmed section for the cable, this would require a longer overall connector length which would increase material costs.
• the purpose of the present invention is to obviate or mitigate the disadvantages of known connectors for coaxial cable.
• a connector for use with a coaxial cable of the type having a central conductor, a dielectric insulator with a foil cover encasing the central conductor, at least one braided shield surrounding the foil covered dielectric insulator, and a plastic jacket covering the braided shield.
• the connector comprises an internal body, means for interconnecting the connector to an electrical device, and an external body, assembled together so as to resist subsequent disassembly.
• the connector is adapted to receive a coaxial cable and to tightly hold the cable and form a seal with it by moving the external body relative to the internal body without disassembling the external body from the internal body.
• the internal body is preferably in the form of a mandril that has a bore of a diameter to receive the dielectric insulator of the coaxial cable.
• the mandril has a sleeve with an end adapted to engage the cable beneath the braided shield and jacket.
• the interconnecting means preferably comprises threaded nut means which is connected to the mandril at the end thereof remote from the sleeve end adapted to engage the cable.
• the external body is preferably in the form of a gripping bushing that is mounted to the connector surrounding the mandril and concentric to it. At its free end it has a bore of a diameter to receive the jacket of the cable.
• the bushing is moveable from a first position in which the bore of the bushing and the sleeve of the mandril define an annular gap to receive the braided shield and the jacket of the cable, to a second position in which the annular gap between the bushing and the sleeve of the mandril is reduced, thereby squeezing the braided shield and the jacket of the cable.
• the nut means is rotatably mounted to the mandril and retained thereto by a flange on the mandril. More preferably, the sleeve of the mandril is tapered and barbed.
• the gripping bushing is assembled with the mandril by close frictional contact and is moveable slidingly from its first position to its second position by means of a squeezing tool.
• the connector also includes an O-ring retained upon the mandril close to the nut means, and the bushing slides over the O-ring when it is moved into its second position.
• the connector of the present invention provides an effective solution to the problems presented by known prior art coaxial cables, as described above.
• the connector of the present invention is preassembled. No separate pieces are involved that must be threaded onto the cable, and which can be misoriented or lost.
• the dimensional tolerances of the connector of the present invention moreover, enable it to be used with the standard sized security ring.
• the connector of the present invention easily accepts coaxial cable having multiple layers of braided shielding with longer trimmed sections that facilitate folding of the braided shielding back over the cable jacket.
• Fig. 1 is an exploded perspective view of a cable connector of the present invention, shown with a coaxial cable;
• Fig. 2 is a cross-sectional side view of the connector of Fig. 1;
• Fig. 3 is a cross-sectional side view of the same connector as shown in Fig. 2, with a coaxial cable having been inserted therein;
• Fig. 4 is a cross-sectional side view of the same connector as in Fig. 3, with the coaxial cable having been inserted further therein;
• Fig. 5 is a cross-sectional side view of the same connector as in
• the coaxial cable connector is denoted generally by reference number 10.
• the cable is denoted by reference number 40 and is of a standard configuration comprising a central conductor 41, a dielectric insulator 42 with a foil cover 43, a braided shield 44 and a plastic jacket 45.
• the connector 10 com rise a mandril 11. a nut member 12, an
• the O-ring 13 is made of a compressible, elastomeric material, such as rubber or plastic, and the mandril
• nut member 12, retainer 14, and bushing 15 are all made of a rigid material, preferably metallic, such as brass.
• the mandril 11 is generally cylindrical having an enlarged base with a sleeve 17 extending therefrom.
• a flange 16 projects outwardly from the end of the enlarged base of the mandril 11.
• the sleeve 17 has a tapered end 18 with a barb 19.
• a bore 20 extends through the mandril 11 having a diameter to receiving the dielectric 42 and its foil cover 43 and the conductor 41.
• the nut member 12 is mounted rota tab ly to the mandril 11.
• the nut member 12 has a collar 23 that engages the flange 16 of the mandril 11 to permit free rotation between the nut member 12 and the mandril.
• the nut member 12 is provided with internal threads 25 and hexagonal flats 24.
• the retainer 14 is generally cylindrical and is fixedly mounted to the mandril 11.
• the retainer 14 has a base 26 with a wall 27 extending therefrom.
• the base 26 has an internal diameter that allows it to be mounted to the enlarged base of the mandril 11 and held securely by frictional engagement.
• a square shoulder 22 on the enlarged base of the mandril 11 provides a seat for the base 26 of the retainer 14.
• the O-ring 13 is of a size and dimension to seat in the annular groove 28, and to extend slightly beyond the retainer 14.
• the bushing 15 is also cylindrical and has a mouth 31 at one end dimensioned to receive the coaxial cable 40.
• the other end of the bushing 15 is adapted to be mounted to the retainer 14 with a close fitting but slidable engagement.
• a first step 29 reduces the internal diameter of the bushing from a dimension corresponding to the outside diameter of the retainer 14 to a dimension corresponding to the inside diameter of the wall 27 of the retainer 14.
• the first step 29 of the bushing 15 seats against the end of the wall 27 of the retainer 14 when the bushing 15 has been activated to slide into its clamping position, as shown in Fig. 5.
• a second step 30 on the internal surface of the bushing 15 defines the depth of the mouth 31.
• the connector 10 is assembled by first mounting the nut member 12 to the mandril 11, then mounting the O-ring 13, and subsequently mounting the retainer 14, which prevents the O-ring 13 and the nut member 12 from subsequent removal from the mandril 11.
• the bushing 15 is mounted to the retainer 14 as shown best in Fig. 2.
• the cable is first prepared by exposing a length of the central conductor 41, and also stripping a further length of the dielectric 42 and its foil-cover 43.
• the braided shield 44 is cut slightly longer than the jacket 45 and is folded back over the edge thereof, as shown in Fig. 1.
• the cable 40 is inserted into the connector 10 such that the conductor 41, the dielectric 42 and the foil 43 are received within the bore 20 of the mandril 11.
• the tapered end 18 of the mandril slides beneath the braided shield 44 and the jacket 45 of the cable 40.
• the barb 19 on the sleeve 17 of the mandril 11 resists subsequent removal of the cable 40 from the mandril 11.
• the connector When the cable 40 has been fully inserted into the connector 10 such that the conductor 41 extends into the nut member 12, the connector is placed in a levered squeezing tool (not shown) by means of which the bushing 15 can be forced to slide over the retainer 14 and the O-ring 13.
• the gap 32 between the bushing 15 and the tapered end 18 of the mandril 11 is reduced, as shown in Fig. 5.
• the second step 30 of the bushing 15 impinges upon the cable 40, squeezing the braided shield 44 and jacket 45 between the mouth 31 of the bushing 15 and the tapered end 18 of the mandril 11 such that when the bushing 15 is collapsed fully onto the retainer 14, with the first step 29 seated upon the end of the wall 27, the cable 40 is clamped tightly by the connector 10 with a moisture seal formed between the jacket 45 of the cable and the mouth 31 of the bushing 15.
• the end of the bushing 15 that is mounted to the retainer 14 contacts and compresses the O-ring 13 within the annular groove 28 to provide a more secure seal between the nut member 12 and the mandril 11.
• the retainer and mandril could be an integral body.
• the configuration of the connector and its component parts could also be modified. Means other than the threaded nut member could be substituted for engagement of the connector to an electronic device.
• the O-ring could be replaced with a different type of sealing means between the mandril and the nut member, and the placement of such O-ring or other sealing means could as well be altered.

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• Coupling Device And Connection With Printed Circuit (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=4160851

Family Applications (1)

Country Status (7)

Cited By (1)

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• 1997
  • 1997-06-09 CA CA002207287A patent/CA2207287C/en not_active Expired - Lifetime
• 1998
  • 1998-06-09 AT AT98925365T patent/ATE235748T1/de not_active IP Right Cessation
  • 1998-06-09 AU AU77546/98A patent/AU7754698A/en not_active Abandoned
  • 1998-06-09 EP EP98925365A patent/EP0988666B1/de not_active Expired - Lifetime
  • 1998-06-09 IL IL13341798A patent/IL133417A0/xx unknown
  • 1998-06-09 WO PCT/CA1998/000557 patent/WO1998057395A1/en active IP Right Grant
  • 1998-06-09 DE DE69812620T patent/DE69812620D1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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