Cable connector

[0001] 1. Field of the Invention

[0002] The present invention relates to cable connectors and more particularly, to such a cable connector for coaxial cable that enhances its engagement with the connected coaxial cable when the coaxial cable is stretched.

[0003] 2. Description of the Related Art

[0004] A conventional cable connector is known comprising a body member and a collar threaded onto the body member to hold a core tube on the inside. When a cable is inserted through the collar into the core tube inside body member to force a central conductor of the cable into close contact with a matching female metal terminal, the collar is fastened up, thereby locking the cable. However, if the cable is stretched accidentally, the central conductor of the cable may be disconnected from the matching female metal terminal, interrupting signal transmission.

[0005] There is known another design of cable connector according to the prior art. This design of cable connector, as shown in FIG. 7, comprises a body member 1, a collar 2 threaded onto one end of the body member 1 and having an insertion hole 21 for the insertion of a coaxial cable 5, and a tubular core 32 that has one end press-fitted into the body member 1 and the other end inserted into the insertion hole 21 of the collar 2. The tubular core 2 has at least one barbed portion 33 for hooking the coaxial cable 5. Because the tubular core 32 is affixed to the body member 1, it is not movable with the coaxial cable 5 when the coaxial cable 5 is stretched accidentally. During installation, a user must fasten the collar 2 tightly to have the barbed portion 33 of the tubular core 32 suspend in the insertion hole 21 so that an outer cylindrical conducting sheath 53 and an outer insulating layer 54 of the coaxial cable 5 can be positively engaged in between the barbed portion 33 of the tubular core 32 and the peripheral edge of the insertion hole 21 of the collar 2. Because the user cannot know whether the barbed portion 33 of the tubular core 32 has reached the place inside the insertion hole 21 during installation, the user must employ much effort to fasten the collar 2 to the body member 1 tightly. Employing an excessively high pressure to the collar 2 against the coaxial cable 5 may cause the outer cylindrical conducting sheath 53 and the outer insulating layer 54 of the coaxial cable 5 to break.

[0006] The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a cable connector for fastening to a coaxial cable to keep a central conductor of a coaxial cable in positive contact with a female metal terminal that enhances its engagement with the connected coaxial cable when the coaxial cable is stretched accidentally.

[0007] According to one aspect of the present invention, the cable connector comprises a hollow body member, a collar fastened to the body member and having an insertion hole on the center of its one end for the insertion of a coaxial cable and defining with the body member an accommodation chamber, and a sliding member axially slidably accommodated in the accommodation chamber. The sliding member has a tubular core perpendicularly extending from the center of one side of a base thereof and barbered portions formed on the periphery of the free end of the tubular core remote from the base for engagement with an outer cylindrical conducting sheath of a coaxial cable that is inserted into the insertion hole of the collar to stop the outer cylindrical conducting sheath and the outer insulating layer of the coaxial cable against the peripheral edge of the insertion hole of the collar, and a through hole axially extending through said tubular core and the base for receiving an insulating spacer the a central conductor of the coaxial cable.

[0008] According to another aspect of the present invention, the cable connector further comprises an elastic member sleeved onto the tubular core of the sliding member and stopped between the base of the sliding member and an inside wall of the collar around the insertion hole of the collar. The elastic member can be, for example, a compression spring. Because the compression spring is sleeved onto the tubular core and stopped between the base of the sliding member and a part inside of the collar, the compression spring prohibits the sliding member from biasing when the connected coaxial cable is stretched to move the sliding member in the accommodation chamber. When the external stretching force disappeared, the compression spring returns the sliding member. When the sliding member is returned to its former position and stopped against the inside wall of the body member, the compression spring holds down the sliding member in place.

[0016] Referring to FIG. 1, a cable connector in accordance with a first embodiment of the present invention is shown comprised of a body member 1, a collar 2 and a sliding member 3.

[0017] The body member 1 is a hollow casing having its first end provided with an axially extending orifice 11 and an embossed portion 12 on the periphery around the orifice 11 and its second end externally threaded.

[0018] The collar 2 is internally threaded for threading onto the externally threaded second end of the body member 1, having an embossed portion 22 on the periphery and an insertion hole 21 axially extending on the center its one end. When the collar 2 is threaded onto the externally threaded second end of the body member 1, the body member 1 and the collar 2 define an accommodation chamber 10 for accommodating the sliding member 3.

[0019] The sliding member 3 has a base 31 that has a profile substantially equal to but relatively smaller than the inner diameter of the body member 1 such that the base 31 is axially movable in the body member 1, a tubular core 32 perpendicularly extending from the center of one side of the base 31, at least one barbed portion 33 formed on the periphery of the free end of the tubular core 32, and a through hole 34 axially extending through the tubular core 32 and the base 31. According to this embodiment, multiple barbed portions 33 are extending around the periphery of the free end of the tubular core 32 and arranged in parallel. Further, an elastic member, for example, a compression spring 35 is sleeved onto the tubular core 32.

[0020] During installation, the sliding member 3 is inserted into the body member 1 and the compression spring 35 is sleeved onto the tubular core 32 of the sliding member 3, and then the collar 2 is threaded onto the externally threaded second end of the body member 1 and stopped at one end of the compression spring 35 to force the base 31 against the inner surface of the peripheral wall of the body member 1 around the orifice 11. When installed, the sliding member 3 can be moved axially in the accommodation chamber 10 defined within the body member 1 and the collar 2.

[0021] Referring to FIGS. 2 and 3 and FIG. 1 again, the cable connector is adapted for fastening a coaxial cable 5 that comprises a central conductor 51, an insulating spacer 52 surrounding the central conductor 51, an outer cylindrical conducting sheath 53 surrounding the insulating spacer 52, and an outer insulating layer 54 surrounding the outer cylindrical conducting sheath 53. After insertion of the coaxial cable 5 through the insertion hole 21 of the collar 2 into the accommodation chamber 10, the tubular core 32 of the sliding member 3 is inserted in between the insulating spacer 52 and the outer cylindrical conducting sheath 53 of the coaxial cable 5 to have the central conductor 51 and the insulating spacer 52 of the coaxial cable 5 be received in the through hole 34 of the sliding member 3, and the central conductor 51 is inserted through the orifice 11 of the body member 1 to the outside of the cable connector. When fastened up the collar 2 tightly, the barbed portion 33 is forced into positive engagement with the outer cylindrical conducting sheath 53 of the coaxial cable 5.

[0022] As stated above, after insertion of the coaxial cable 5 into the insertion hole 21 of the collar 2, a user simply needs to rotate the collar 2 forwards toward the body member 1. At this time, the compression spring 35 will be forced to impart an axial pressure to the sliding member 3 in direction toward the collar 2 toward the body member 1, thereby forcing the barbed portion 33 into positive engagement with the outer cylindrical conducting sheath 53 of the coaxial cable 5. Therefore, the installation of the present invention is quick simple without much effort or the use of any tools.

[0023] When the coaxial cable 5 is stretched outwards accidentally, the sliding member 3 will be moved with the coaxial cable 5 to compress the compression spring 35, and at the same time the barbed portion 33 will force the outer cylindrical conducting sheath 53 and the outer insulating layer 54 of the coaxial cable 5 against the periphery of the insertion hole 21 of the collar 2, securing the coaxial cable 5 tightly to the collar 2. Therefore, increasing the outward stretching force will enhance the engagement between the coaxial cable 5 and the cable connector.

[0024] Further, because the distance between the insertion hole 21 and the barbed portion 33 is shorter than the combined thickness of the outer cylindrical conducting sheath 53 and the outer insulating layer 54 of the coaxial cable 5, the outer cylindrical conducting sheath 53 and the outer insulating layer 54 of the coaxial cable 5 will be forced to deform a certain length of time after having been squeezed between the barbed portion 33 of the sliding member 3 and the periphery of the insertion hole 21 of the collar 2 if the sliding member 3 is not returned to its former position. This problem is prevented because the spring force of the compression spring 35 automatically returns the sliding member 3 to its former position immediately after disappearance of the external stretching force. Therefore, the invention greatly prolongs the service life of the cable connector and the cable.

[0025] Further, because the compression spring 35 is sleeved onto the tubular core 32 and stopped between the base 31 of the sliding member 3 and a part inside of the collar 2, the compression spring 35 prohibits the sliding member 3 from biasing during sliding movement of the sliding member 3 in the accommodation chamber 10. When the sliding member 3 is returned to its former position and stopped against the peripheral wall of the body member 1 around the orifice 11, the compression spring 35 holds down the sliding member 3 in place.

[0026] The cable connector further comprises a terminal holder unit 4 fastened to the orifice 11 of the body member 1. The terminal holder unit 4 comprises a locating member 41 that has one end hooked in the orifice 11 of the body member 1, a terminal bearing member 42 fastened to the inside of the locating member 41, and a female metal terminal 43 axially mounted in the terminal bearing member 42. When the coaxial cable 5 is inserted into the body member 1 and the collar 2, the central conductor 51 of the coaxial cable 5 is inserted through the orifice 11 of the body member 1 into the inside of the female metal terminal 43 and kept in close contact with the inside wall of the female metal terminal 43, and therefore the coaxial cable 5 is electrically connected to the electric socket (not shown) to which the terminal holder unit 4 is fastened.

[0027] Further, a gasket ring 13 is mounted in between the body member 1 and the collar 2 to seal a gap between the body member 1 and the collar 2. After insertion of the coaxial cable 5 into the body member 1 and the collar 2, the coaxial cable 5 blocks the insertion hole 21 of the collar 2, and therefore the gasket ring 13 and the terminal bearing member 42 keep the accommodation chamber 10 in a watertight status.

[0028] FIG. 4 is a schematic sectional view of a cable connector in accordance with a second embodiment of the present invention. This second embodiment is substantially similar to the aforesaid first embodiment with the exception that the body member 1 of this second embodiment is relatively longer than the aforesaid first embodiment so that the terminal bearing member 42 and the female metal terminal 43 are directly mounted inside the body member 1 for the connection of the central conductor 51 of the coaxial cable 5.

[0029] FIG. 5 is a schematic sectional view of a cable connector in accordance with a third embodiment of the present invention. This third embodiment is substantially similar to the aforesaid first embodiment with the exception that the terminal holder unit 4 of this third embodiment is directly fastened to the outside wall of the body member 1 to hold the locating member 41 in the body member 1, and two terminal bearing members 42 are fastened to the front and rear sides inside to hold the female metal terminal 43 for the connection of the central conductor 51 of the coaxial cable 5.

[0030] FIG. 6 is a schematic sectional view of a cable connector in accordance with a fourth embodiment of the present invention. This fourth embodiment is substantially similar to the aforesaid first embodiment with the exception that the body member 1 is an angled casing with its orifice 11 extending vertically upwards for the mounting of the terminal holder unit 4 so that the female metal terminal 43 and the central conductor 51 of the coaxial cable 5 are connected at right angles.

[0031] In conclusion, the invention provides a cable connector that comprises a body member 1 that is a hollow casing having an orifice 11 at one end, a collar 2 fastened to the body member 1 and having an insertion hole 21 in axial alignment with the orifice 11 of the body member 1 and defining with the body member 1 an accommodation chamber 10 in communication between the insertion hole 21 of the collar 2 and the orifice 11 of the body member 1, a sliding member 3 that is accommodated in the accommodation chamber 10 and having a tubular core 32 extending from the center of one side of a base 31 thereof and terminating in a barbed portion 33, and an elastic member, for example, compression spring 35 sleeved onto the tubular core 32 and stopped between the base 31 of the sliding member 3 and an inside wall of the collar 2 around the insertion hole 21. When a coaxial cable 5 is inserted into the insertion hole 21 of the collar 2, the tubular core 32 of the sliding member 3 is inserted in between an insulating spacer 52 and an outer cylindrical conducting sheath 53 of the coaxial cable 5, a central conductor 51 and the insulating spacer 52 of the coaxial cable 5 are received in the tubular core 32 of the sliding member 3, and the central conductor 51 of the coaxial cable inserted through the orifice 11 to the outside of the body member 1 for connection to a female metal terminal 43. When fastened up the collar 2, the collar 2 imparts a pressure to the outer insulating layer 54 and the outer cylindrical conducting sheath 53 of the coaxial cable 5 in positive engagement with the barbed portions 33 of the sliding member 3. In case the coaxial cable 5 is stretched accidentally, the barbed portions 33 of the sliding member 3 will be pulled toward the insertion hole 21 of the collar 2, thereby giving a pressure to the outer cylindrical conducting sheath 53 and the outer insulating layer 54 of the coaxial cable 5 against the peripheral edge of the insertion hole 21 of the collar 2, enhancing the engagement between the coaxial cable 5 and the cable connector.

[0032] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.