The present invention relates generally to connectors for terminating coaxial cable and more particularly to a coaxial cable connector having a cable gripping feature.
It has long been known to use connectors to terminate coaxial cable so as to connect a cable to various electronic devices such as televisions, radios and the like. Prior art coaxial connectors generally include a connector body having an annular collar for accommodating a coaxial cable, an annular nut rotatably coupled to the collar for providing mechanical attachment of the connector to an external device and an annular post interposed between the collar and the nut. A resilient sealing O-ring may also be positioned between the collar and the nut at the rotatable juncture thereof to provide a water resistant seal thereat. The collar includes a cable receiving end for insertably receiving an inserted coaxial cable and, at the opposite end of the connector body, the nut includes an internally threaded end extent permitting screw threaded attachment of the body to an external device.
This type of coaxial connector further includes a locking sleeve to secure the cable within the body of the coaxial connector. The locking sleeve, which is typically formed of a resilient plastic, is securable to the connector body to secure the coaxial connector thereto. In this regard, the connector body typically includes some form of structure to cooperatively engage the locking sleeve. Such structure may include one or more recesses or detents formed on an inner annular surface of the connector body, which engages cooperating structure formed on an outer surface of the sleeve. A coaxial cable connector of this type is shown and described in commonly owned U.S. Pat. No. 6,530,807.
Conventional coaxial cables typically include a center conductor surrounded by an insulator. A conductive foil is disposed over the insulator and a braided conductive shield surrounds the foil covered insulator. An outer insulative jacket surrounds the shield. In order to prepare the coaxial cable for termination, the outer jacket is stripped back exposing an extent of the braided conductive shield which is folded back over the jacket. A portion of the insulator covered by the conductive foil extends outwardly from the jacket and an extent of the center conductor extends outwardly from within the insulator. Upon assembly to a coaxial cable, the annular post is inserted between the foil covered insulator and the conductive shield of the cable.
A problem with current coaxial connectors is that they often do not adequately grip the coaxial shielded cables, particularly with smaller diameter coaxial cables. In particular, current coaxial cable connectors often rely on the post barb as the principal means for providing cable retention. This requires pushing the cable braid and jacket over the barb, thereby expanding the braid and jacket. Such expansion requires increased cable insertion force, making installation more difficult. Moreover, sealing the interior of the connector from outside elements also becomes more challenging with smaller diameter cables.
Accordingly, it would be desirable to provide a coaxial cable connector with structural features to enhance gripping, thereby facilitating cable insertion particularly with smaller diameter cables.
It is an object of the present invention to provide a coaxial cable connector for terminating a coaxial cable.
It is a further object of the present invention to provide a coaxial cable having structure to enhance gripping of a coaxial cable, especially a small diameter coaxial cable.
In the efficient attainment of these and other objects, the present invention provides a coaxial cable connector. The connector of the present invention generally includes a connector body having a rearward sleeve receiving end and an inner engagement surface and an axially movable locking sleeve seated in the rearward sleeve receiving end of the connector body. The locking sleeve has a rearward cable receiving end and an opposite forward connector insertion end. The forward connector insertion end is formed with at least one flexible finger for gripping a cable inserted in the sleeve when the locking sleeve is moved from a first position to a second position.
In a preferred embodiment, the connector body includes an internal ramp portion formed on the inner engagement surface for deflecting the flexible finger radially inward as the locking sleeve is moved from the first position to the second position. The flexible finger also preferably includes a tapered forward end defining a sharp edge to facilitate gripping of the cable.
The connector may further include an annular post disposed within the connector body and a nut rotatably coupled to the post. The sleeve and/or the connector body can be made from a plastic material and preferably include cooperating engagement surfaces to permit the axial movement of the sleeve from the first position, wherein a cable is loosely retained in the connector, to the second position, wherein a cable is secured in the connector.
The locking sleeve preferably includes a plurality of flexible fingers defining the forward connector insertion end of the sleeve. In this manner, at least two adjacent fingers of the sleeve can be connected by a web to increase gripping strength. Also, the flexible finger can include a lateral groove formed therein to enhance flexibility of the finger.
The present invention further involves a method for terminating a coaxial cable in a connector. The method includes the steps of inserting an end of a cable into a rearward cable receiving end of a locking sleeve and axially moving the locking sleeve with respect to a connector body from a first position, wherein a cable is loosely retained in the connector, to a second position, wherein a cable is secured in the connector. The axial movement of the sleeve causes a flexible finger provided on the sleeve to deflect radially inward to grip the end of the cable. In this regard, the flexible finger can be made to engage an internal ramp portion of the connector body, which deflects the finger radially inward as the locking sleeve is moved from the first position to the second position.
To further enhance gripping of the cable, the annular post disposed within the connector body preferably includes a first radially outwardly projecting barb disposed at a rearward end thereof and a second radially outwardly projecting barb disposed forward of the first barb. More specifically, the post may include a shoulder portion in press-fit engagement with the connector body and an annular tubular extension extending between the shoulder portion and the first and second barbs and having a maximum outer diameter. The first and second barbs thus have an outer diameter greater than the maximum outer diameter of the annular tubular extension.
The gripping action of the fingers increases cable retention. This allows reducing the diameter of the barb on the post which facilitates cable insertion. Therefore, the present invention allows a user to insert a coaxial shielded cable into the coaxial connector with less force than current connectors to prevent buckling of the coaxial shielded cable. The present invention also allows for the coaxial shielded cable to be held securely within the coaxial connector without buckling the coaxial shielded cable.
For a better understanding of the present invention, reference is made to the following description to be taken in conjunction with the accompanying drawings and its scope will be pointed out in the appended claims.
Referring to
A typical coaxial shielded cable 10 is shown in
To prepare the coaxial shielded cable 10 for use with the connector 30, the cable is stripped using a wire cutter or similar device. A portion of the center conductor 12 is exposed by removing a portion of the dielectric covering 14. The foil 16 remains covering the dielectric layer 14. The metallic braid 18 is folded back over on the outer covering 20 to form an overlapping portion 21. The overlapping portion 21 extends partially up the length of the outer covering 20. The prepared end 22 of the coaxial shielded cable 10 is shown in
Referring to
Referring to
The terminal 56 has a hollow portion 60 sized to receive the center conductor 12 of the coaxial shielded cable 10. The terminal 56 has a first end 57 which extends toward the first end 34 of the housing 32. The first end 57 forms the opening to the hollow portion 60 of the terminal 56. Positioned within the hollow portion 60 is at least one spring contact 58 made of a resilient metallic material and is positioned to contact the center conductor 12 of the coaxial shielded cable 10. In an alternative embodiment (not shown), the spring contact 58 can be integrally formed with the terminal 56 to create a one piece terminal. The second end 58 of the terminal 56, opposite the first end 57, takes the form of a metal prong 62 extending toward the second end 38 of the connector 30.
Still referring to
Referring additionally to
A plurality of resilient tabs or fingers 78 are positioned around the opening of the sleeve aperture 76 on the upper portion 74 of the sleeve 40. The resilient tabs 78 have beveled or angled end portions 80 (
The sleeve 40 can also have an annular rim 86 on the outer surface 73 of the sidewall 72. The housing 32 can have on its inner surface 37 a corresponding groove 88 which accepts the annular rim 86 to create a cooperating detent locking structure between the sleeve 40 and the housing. Preferably, the outer diameter of the sleeve 48 is sized smaller than the inner diameter 36 of the first end 34 to allow the sleeve 40 to be inserted into the first end 34.
In order to use the present invention, the user first prepares the coaxial shielded cable 10 as shown in
Referring to
The user continues to insert the sleeve 40 into the first end 34 until the annular rim 86 becomes engaged with the corresponding groove 88 in the inner surface 37 of the first end 34 to hold the sleeve 40 in place. At the same time, an upper ledge 71 of the base 70 can contact the first end 34 to indicate to the user that the sleeve 40 is fully inserted into the first end 34. The tension created between the resilient tabs 78 and the post 66, along with the additional gripping force provided by the barbs 64, prevent the coaxial shielded cable 10 from being inadvertently removed from the connector 30.
Referring now to
The connector body 102 is an elongate generally cylindrical member, which is preferably made from plastic to minimize cost. Alternatively, the body 102 may be made from metal or the like. The body 102 has one end 103 coupled to the post 104 and the nut 106 and an opposite sleeve receiving end 110 for insertably receiving the sleeve 108. The sleeve receiving end 110 defines an inner engagement surface 112 having one or more grooves 114 and/or projections 115, which engage cooperating grooves 116 and/or projections 117 formed on the outer surface of the sleeve 108 for locking the sleeve in the body 108.
The annular post 104 includes a flanged base portion 118, which is rotatably seated in a post receiving space in the nut 106, and a widened shoulder portion 120, which provides for press-fit securement of the post within the collar 102. The annular post 104 further includes an annular tubular extension 122 extending rearward within the body 102 and into the sleeve 108. As mentioned above, the rearward end of the tubular extension 122 preferably includes a radially outwardly extending ramped flange portion or “barb” 124 having a forward facing edge 125 for compressing the outer jacket of the coaxial cable against the internal diameter of the body to secure the cable within the connector. Alternatively, and/or depending on the method of forming the post 104, the barb 124 may be more rounded as opposed to having a sharp edge 125. In any event, as will be described in further detail hereinbelow, the extension 122 of the post 104, the body 102 and the sleeve 108 define an annular chamber 126 for accommodating the jacket and shield of the inserted coaxial cable.
The nut 106 may be in any form, such as a hex nut, knurled nut, wing nut, or any other known attaching means, and is rotatably coupled to the post 104 for providing mechanical attachment of the connector 100 to an external device. The nut 106 includes an internally threaded end extent 128 permitting screw threaded attachment of the connector 100 to the external device. The sleeve 108 and the internally threaded end extension 128 define opposite ends of the connector 100.
The locking sleeve 108 is a generally tubular member having a rearward cable receiving end 130 and an opposite forward connector insertion end 132, which is movably coupled to the inner surface 112 of the connector body 102 to allow for axial movement of the sleeve 108 within the connector body 102 along arrow A of
The locking sleeve 18 further preferably includes a flanged head portion 134 disposed at the rearward cable receiving end 130 thereof. The head portion 134 has an outer diameter larger than the inner diameter of the body 102 and includes a forward facing perpendicular wall 136, which serves as an abutment surface against which the rearward end of the body 102 stops to prevent further insertion of the sleeve 108 into the body 102.
The forward end 132 of the sleeve 108 is further formed with a plurality of flexible fingers 138 extending in the forward direction. These fingers 138 are forced to deflect radially inwardly by an internal ramp portion 140 formed on the inner engagement surface 112 of the connector body 102 during insertion of the sleeve 108 into the body. As the fingers 138 are deflected inward, they engage the outer jacket of the cable 10 to enhance the gripping of the cable within the connector 100.
Referring additionally to
Alternatively, as shown in
In use, the cable 10 is prepared as described above by stripping back the jacket 20 exposing an extent of shield 18. A portion of the foil covered insulator 14 extends therefrom with an extent of conductor 12 extending from the insulator. After an end extent of shield 18 is folded back about jacket 20, the cable 10 may be inserted into the connector 100 with the sleeve 108 already coupled to the body 102, as shown in
Once the cable 10 is properly inserted, the sleeve 108 may be moved axially forward in the direction of arrow A from the first position shown in
As the sleeve 108 moves to this second position, the jacket 20 and shield 18 of the cable 10 begin to become compressively clamped within the annular region 126 between the barb 124 of the post 104 and the inner surface of the sleeve 180. In this regard, the inner surface of the sleeve 18 is preferably provided with an inwardly directed shoulder portion 149 to facilitate compression of the cable jacket 20 against the barb 124 of the post 104. Also, as the sleeve 108 moves to its second position, the sleeve fingers 138 are urged inwardly by the ramp 140 formed in the connector body 102 to further engage the cable jacket 20.
To further enhance locking of the cable 10, the post 104 of the present invention is preferably provided with a second annular cable retention barb 150 disposed forward of the rearward end barb 124. Both the rearward end barb 124 and the forward barb 150 are annular protrusions extending radially outwardly from the outer diameter of the tubular extension 122. In other words, like the first barb 28, the second barb 74 is generally an annular, radially outwardly extending, ramped flange portion of the post 104 having a forward facing edge for compressing the outer jacket of the coaxial cable to secure the cable within the connector 100. The second barb 150 improves both the mechanical retention of the cable as well as the electromagnetic isolation or shielding of the signal inside the connector.
Although the illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.
Various changes to the foregoing described and shown structures will now be evident to those skilled in the art. Accordingly, the particularly disclosed scope of the invention is set forth in the following claims.
This application claims the benefit of U.S. Provisional Application No. 60/660,653, filed on Mar. 11, 2005.
Number | Date | Country | |
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60660653 | Mar 2005 | US |