Coaxial Cable Connector

Abstract

A connector for attachment to the end of a coaxial cable having an axial core electrode and an outer conductive sheath electrode includes a sheath-gripping ferrule and a collet sleeve for gripping an exposed forward end portion of the core electrode. The ferrule and the collet sleeve are disposed within a tubular housing and a plug bolt is threaded into the rearward end of the connector for tightening both the ferrule and the collet sleeve radially inwardly against the electrodes. Forward axial movement of the plug bolt is converted to forward and radially inward movement of the sheath-gripping ferrule through a first pair of co-acting frusto-conical cam surfaces and the resulting movement of the ferrule is operative through at least one second pair of frusto-conical cam surfaces to cause radially inward compression of the collet sleeve onto the exposed forward end portion of the core electrode.

Description

The present invention relates to electrical connectors and more particularly relates to connectors intended for securement to coaxial cables of the type used in CATV distribution systems.

Many different electrical connectors for the aforementioned purpose are presently available but the practical requirements for an effective re-usable connector of this type have proved to be difficult to attain.

From a commercial point of view, to maintain costs as low as possible, it is desirable that such a connector has the minimum possible number of component parts consistent with effective operation and that the manufacture and assembly of such a connector should involve as few manufacturing steps as possible. Also, such a connector must present electrical characteristics to match the electrical characteristics of the coaxial cable to which it is secured to avoid signal distortion.

It is a principal object of the present invention therefore to provide an inexpensive electrical connector which is simple in construction and which is simple to manufacture.

Another important requirement of such a connector is that it provide a positive grip on both the core electrode and the outer conductive sheath electrode of a coaxial cable since, in the absence of such positive securement to both electrodes, the different thermal expansion rates of the two electrodes can lead to the core electrode being pulled loose from such a connector, particularly when the electrodes are exposed to large temperature variations.

Still another important requirement of an electrical connector particularly intended for use in a CATV system is that such a connector should incorporate an adequate seal against the ingress of moisture and dirt into the connector and consequently ultimately into the electrical insulation disposed between the core electrode and the outer sheath of such a coaxial cable, without cracking or damaging the cable shield component while permitting facile release and re-use of the connector.

It is another important object of this invention therefore to provide an electrical connector for positive fluid-tight securement to the components of a coaxial cable which will permit release and re-use of the connector and cable.

And another object of the invention is the provision of a connector particularly suited for use in CATV distribution systems.

In its broadest scope, the present invention provides a connector for securement to a coaxial cable having a core electrode and an outer conductive sheath and which connector comprises a housing, a radially inwardly compressible and electrically conductive ferrule disposed within said housing for both forward movement therein and radially inward compression into gripping engagement and electrical contact with the outer conductive sheath of the coaxial cable inserted into said connector, means movably mounted on said housing for causing said forward movement and said radially inward compression of said electrically conductive ferrule, and a radially inwardly compressible and electrically conductive collet sleeve mounted generally axially within said housing and electrically insulated from said electrically conductive ferrule for receiving an exposed forward end portion of the core electrode of the coaxial cable inserted into said connector and having associated therewith a rearwardly facing external cam surface for contiguous surface abutment with a forwardly facing internal cam surface associated with said electrically conductive ferrule whereby, on forward movement and radially inward compression of said electrically connective ferrule into gripping engagement and electrical contact with the outer conductive sheath of the coaxial cable, resulting forward movement of said forwardly facing internal cam surface associated with said electrically conductive ferrule is operative, by virtue of its abutment with said rearwardly facing external cam surface associated with said collet sleeve, to cause radially inward compression of said collet sleeve into said gripping engagement and electrical contact with the core electrode of the cable.

In accordance with a particularly useful feature of this invention, the sheath-gripping ferrule of such a connector is usefully integrally formed with a rearwardly facing external frusto-conical cam surface and with a forwardly facing internal frusto-conical cam surface. Such rearwardly facing external cam surface can then be adapted to coact with a corresponding forwardly facing internal cam surface of a thrust ring which can be moved forwardly relative to and within the housing of the connector by a plug bolt threadedly inserted into the rearward end of such a housing. The forwardly facing internal cam surface of the ferrule of such a preferred embodiment of a connector can similarly be arranged to coact with a rearwardly facing external frusto-conical cam surface of a resiliently and radially inwardly compressible and electrically insulating bushing coaxially disposed about the radially inwardly compressible and electrically conductive collet sleeve intended to be compressed radially inwardly into gripping engagement and electrical contact with the exposed forward end portion of the core electrode of the cable.

Other objects, features and advantages of the invention shall become apparent as the description herein proceeds.

The invention will now be described merely by way of illustration with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal, axial sectional view, partly in elevation, through one previously known connector, showing a coaxial cable secured within the connector;

FIG. 2 is an exploded and fragmentary elevation of the prior art connector shown in FIG. 1 with certain parts being omitted or shown in section for the sake of clarity and for the purpose of illustrating the manner of operation of that particular connector;

FIG. 3 is a longitudinal, axial sectional view of another known connector with a coaxial cable secured within the connector;

FIG. 4 is an exploded and fragmentary sectional view of the connector shown in FIG. 3, partly in elevation, illustrating the manner of operation of the connector;

FIG. 5 is a longitudinal, axial sectional view through an embodiment of a connector in accordance with the present invention;

FIG. 6 is an end elevation of a radially inwardly compressible and electrically insulating bushing forming an important component of the connector shown in FIG. 5 as viewed along line 6--6 of FIG. 5; and

FIG. 7 is a longitudinal, axial sectional view through an alternative embodiment of a connector in accordance with the present invention also showing a coaxial cable secured within the connector.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In order to facilitate understanding of the present invention and of the advance in the art provided thereby, the two previously known connectors shown in section in FIGS. 1 and 3 of the accompanying drawings will first be described. The manner in which these known connectors operate will also be described with particular reference to FIGS. 2 and 4 respectively of the drawings.

For convenience, the left-hand ends of all the connectors shown in the accompanying drawings will be referred to herein as the forward ends of those connectors, while the right-hand ends into which coaxial cables can be inserted for securement of the connectors to such cables will be referred to herein as the rearward ends. Similarly, the direction from the rearward end to the forward end of each such plug, as indicated by the arrows A in FIGS. 2 and 4, will be considered as being the forward direction.

Referring first to FIGS. 1 and 2 of the accompanying drawings, it will be seen that the connector generally designated by numeral 10 is shown in its operative position secured to one end of a coaxial cable generally designated by numeral 12. The cable 12 comprises an outer, electrically conductive sheath 13 normally formed of relatively pure aluminum and an axial core wire electrode 14 normally formed of copper. A closed cell foamed plastic insulation 15 is contained within the outer metallic sheath 13 and serves to maintain the core electrode 14 axially positioned therein as well as to insulate the core electrode 14 from the outer sheath 13.

The known connector 10 comprises a tubular metal housing 16, an intermediate tubular metal sleeve 17 and cap 18. The tubular housing 16 is externally threaded at its rearward end at 19 for threaded engagement with a corresponding internal thread 20 provided in the forward end of the tubular sleeve 17. A reduced diameter portion 21 at the rearward end of the tubular sleeve 17 is externally threaded at 22 for threaded engagement with a corresponding internal thread provided in a forwardly extending skirt 24 of the cap 18. An axial opening 25 is provided through the cap 18 and, in use, a cable, such as cable 12, extends freely through such opening 25 into the connector 10.

At its forward end, the tubular housing 16 is provided with a reduced diameter portion 27 externally threaded at 28 by means of which the connector 10 may be screwed into a correspondingly internally threaded opening in a connection or distribution box (not shown) of any appropriate type. A resiliently compressible O-ring gasket 29 is usefully provided at the rearward end of the reduced diameter portion 27 for compression against an external shoulder 30 of the housing 16 when the plug 10 is secured to such a distribution box. The gasket 29 functions as a seal to prevent the entry of dirt and moisture into such a distribution box.

The aforementioned thread 19 extends forwardly along a reduced diameter portion 32 of the tubular housing 16 and the reduced diameter portion 32 is forwardly defined by an external shoulder 33 (FIG. 2) which serves to abut the forward end surface of the tubular sleeve 17 to limit forward movement of that sleeve 17 relative to the housing 16. A resiliently compressible O-ring gasket 34 is disposed within an external annular recess in the reduced diameter portion 32 at the forward end of the thread 19 to provide a seal between the housing 16 and the sleeve 17 when these members are secured together as actually shown in FIG. 1.

Axially disposed within the housing 16 is a metal collet sleeve 36 shown partly in section in FIG. 1 and which is integrally formed with an externally projecting metal connecting pin 37 to the exposed left-hand end of which a wire can be secured, for example, by soldering, to provide an electrical connection. The right-hand or rearward end portion of the collet sleeve 36 is hollow and is formed with a pair of diametrically opposed and axially extending slots 38 to permit the collet sleeve 36 to be compressed radially inwardly in a manner to be described into gripping engagement and electrical contact with an exposed forward end portion 39 of the core electrode 14. The internal surface of the collet sleeve 36 is threaded as at 40, serrated or otherwise disturbed to provide improved gripping with the end portion 39 of the core electrode 14 of the cable 12.

The collet sleeve 36 is maintained in its axial position within the housing 16 by an electrically insulating bushing 42, an inwardly projecting annular lip 43 being integrally formed with the reduced diameter portion 27 of the housing 16 to prevent axially forward movement of such bushing 42 from within the housing 16.

At its rearward end, the tubular housing 16 is formed with a rearwardly facing internal frusto-conical cam surface 44 which diverges radially outwardly in the rearward direction. This cam surface 44 co-operates with a forwardly facing external frusto-conical cam surface 45 of a resiliently and radially inwardly compressible and electrically insulating bushing generally indicated at 46. An axial bore 47 extends through the bushing 46 and this bore 47 is usefully formed with a bevelled entrance 48 at its rearward end to facilitate the entry of the forward end of the core electrode 14 into the rearward end of the collet sleeve 36 which projects into the bore 47.

At its rearward end, the bushing 46 is integrally formed with a radially extending flange 49 having forward and rearward faces 50 and 51 respectively. The bushing 46 is also formed with an axially extending radial slot 52 (FIG. 2) to permit the bushing 46 to be compressed radially inwardly when urged forwardly by means not yet described as a result of engagement of the forwardly facing external cam surface 45 of that bushing 46 with the rearwardly facing internal cam surface 44 of the tubular housing 16. The aforementioned flange 49 defines an enlarged axial recess 54 within which, in use, the forward end of the coaxial cable 12 is received.

A radially inwardly compressible and electrically conductive metal ferrule generally indicated at 56 is disposed within the tubular sleeve 17 for axial movement therewithin. This ferrule 56 is formed with a radially extending forward end surface 57 and a metal washer 58 is disposed between this forward end surface 57 and the rearwardly facing and radially extending surface 51 of the flange 49 of the bushing 46. An axial bore 59 extends through the ferrule 56 and, in use of the connector 10, a coaxial cable 12 is disposed within this bore 59. The internal surface of the bore 59 is threaded, serrated or otherwise disturbed to facilitate gripping engagement and electrical contact between the ferrule 56 and the outer conductive sheath 13 of the cable 12 when the ferrule 56 is radially inwardly compressed into engagement with that sheath 13. The ferrule 56 is also formed with a rearwardly facing external frusto-conical cam surface 60 and with an obliquely disposed slot 61 extending through its peripheral wall to facilitate its radially inward compression into engagement with the outer conductive sheath 13 of the cable 12.

Coaxially disposed around the rearward end of the ferrule 56, there is provided a thrust ring generally indicated at 64 and having a radially extending rear surface 65 and a forwardly facing internal frusto-conical cam surface 66 which, in use, cooperates with the rearwardly facing external cam surface 60 of the ferrule 56. Rearwardly of the thrust ring 64, there is disposed within the tubular sleeve 17 a resiliently compressible cylindrical gasket 67 which is retained between the rear surface 65 of the thrust ring 64 and an internal forwardly facing surface 68 of the cap 18. The tubular sleeve 17 is also provided with a forwardly facing internal annular shoulder 69 which serves to restrict rearward movement of the thrust ring 64 relative to the tubular sleeve 17.

To attach the connector 10 shown in FIGS. 1 and 2 to the forward end of the coaxial cable 12, the outer conductive sheath 13 and the foam insulation 15 of that cable are first removed to provide the exposed forward end portion 39 of the core electrode 14. The cable 12 is then inserted forwardly into the connector 10 with the sleeve 17 and cap 18 of that connector loosened. With the cable correctly inserted into the connector 10, i.e. with the exposed end portion 39 of the core electrode 14 disposed within the collet sleeve 36 and with the forward end of the outer conductive sheath 13 seated in the recess 54 of the bushing 46, the sleeve 17 is then tightened by screwing it onto the housing 16. Such tightening causes forward axial movement of the sleeve 17 relative to that housing 16.

During such forward movement of the sleeve 17, the internal shoulder 69 thereof engages the rearwardly facing and radially extending surface 65 of the thrust ring 64 causing that thrust ring 64 to move forwardly and, as a result of co-action of the internal cam surface 66 of the thrust ring 64 and the external cam surface 60 of the radially inwardly compressible ferrule 56, ferrule 56 moves forwardly as indicated by the arrow A and is compressed radially inwardly into gripping engagement and electrical contact with the outer conductive sheath 13 of the cable 12 disposed therewithin.

Such forward movement of the ferrule 56 is transmitted through the washer 58 to the radially inwardly compressible bushing 46 and resulting co-operative abutment of the forwardly facing cam surface 45 of that bushing 46 with the internal cam surface 44 of the housing 16 causes the bushing 46 to be radially inwardly compressed in turn to compress the collet sleeve 36 into gripping engagement and electrical contact with the exposed forward end portion 39 of the core electrode 14 of the cable 12.

Finally, the cap 18 is tightened on the sleeve 17 to cause axial compression and radial expansion of the gasket 67 into sealing engagement with the sleeve 17 and the outer conductive sheath 13 of the cable 12 to prevent the entry of moisture and dirt into the connector 10. It will be understood that electrical connection can be made to the core electrode 14 through the pin 37 and to the outer conductive sheath 13 through the metal housing 16.

The operation of the connector 10 shown in FIGS. 1 and 2 utilizes the relative axial movement of the sleeve 17 and the housing 16 to cause forward axial movement and radially inward compression of the sheath-gripping ferrule 56. Such forward axial movement of the ferrule 56 is transmitted solely in the axial direction through the washer 58 to the radially compressible bushing 46. Forward axial movement of the bushing 46 then leads independently to radially inward compression of that bushing 46 and consequently to radially inward compression of the collet sleeve 36 axially disposed therewithin.

Referring now to the second previously known connector shown in FIGS. 3 and 4 and generally designated by numeral 110, connector 110 is shown secured to one end of the coaxial cable generally designated by numeral 112.

The connector 110 comprises a tubular metal housing generally indicated at 116 and a tubular metal sleeve 117 omitted from FIG. 4 and threadedly secured to the rearward end of the housing 116 at 119. A radially compressible, slotted and internally serrated metal collet sleeve 136 integrally formed with a forwardly extending connector pin 137 is secured within the housing 116 by an electrically insulating and fixed bushing 142.

A resiliently and radially inwardly compressible and electrically insulating bushing generally indicated at 146 is positioned within the rearward end of the housing 116 but, in distinction to the corresponding bushing 46 of the connector 10 of FIGS. 1 and 2, the bushing 146 is not provided with a frustoconical cam surface corresponding to the cam surface 45 of the bushing 46. Instead, the bushing 146 includes a generally cylindrical, hollow and forwardly extending skirt 172. At its rearward end, the skirt 172 is integrally formed with an annular collar 173 extending radially inwardly to and integrally formed with a rearwardly extending axial boss 174 which in turn includes an axial bore 175 within which the rearward end of the collet sleeve 136 is disposed.

Four equiangularly spaced and radially extending slots 176 are provided through the walls of the boss 174 and these slots 176 extend partially into the skirt 172 to facilitate radially inward compression of the boss 174 and consequently of the collet sleeve 136 in a manner to be described.

A radially inwardly compressible and electrically conductive ferrule generally indicated at 156 is disposed within the sleeve 117 for axial movement therein and this ferrule 156 includes a radially outwardly extending annular flange 178 at its rearward end. A forwardly facing annular internal shoulder 179 is formed in the sleeve 117 and a washer 180 is disposed between the shoulder 179 and a rearwardly facing and radially extending surface 181 of the aforementioned flange 178 of the ferrule 156. The ferrule 156 is internally threaded or serrated at 159 and is formed with an axially extending slot 161 through its peripheral wall so that it can be compressed radially inwardly into gripping engagement and electrical contact with the outer conductive sheath 113 of the cable 112.

At its forward end, the ferrule 156 is formed with a forwardly facing external frusto-conical cam surface 183 which co-operates with a rearwardly facing internal frusto-conical cam surface 144 formed in the rearward end of the housing 116. A radially inwardly extending flange 184 is integrally formed with the ferrule 156 at its forward end and this flange 184 defines an axial opening 185 which, when the connector 110 is assembled as shown in FIG. 3, receives the aforementioned boss 174 of the bushing 146.

Within the sleeve 117 rearwardly of the washer 180, there is freely disposed a generally cylindrical metal sleeve 186 and, at the axial ends of this sleeve 186, resiliently compressible O-ring gaskets 187 and 188 are positioned for the purpose of providing a seal between the sleeve 117 and the outer conductive sheath 113 of the cable 112 when the connector 110 is secured to that cable.

For securement of the connector 110 to the forward end of the cable 112, the latter is initially prepared in exactly the same manner as already described herein with reference to the cable 10 of FIGS. 1 and 2 of the accompanying drawings. The forward end of the cable 112 is inserted into the connector 110 so that the exposed forward end portion 139 of the core electrode 114 of the cable 112 is disposed within the collet sleeve 136 and so that the forward end of the outer conductive sheath 113 of the cable 112 is seated in the ferrule 156 against the rearwardly facing surface of the flange 184 thereof. The sleeve 117 is then tightened on the housing 116. During such tightening movement, action of the shoulder 179 on the rearward end surface 181 of the ferrule 156 through the washer 180 causes forward axial movement of that ferrule 156 as indicated by the arrow A. The resulting abutment of the forward facing cam surface 183 of the ferrule 156 with the internal cam surface 144 of the housing 116 causes radially inward compression of that ferrule 156 into gripping engagement and electrical contact with the outer conductive sheath 113 of the cable 112. Such radially inward compression of the ferrule 156 is transmitted through the flange 184 thereof to the boss 174 of the radially inwardly compressible bushing 146 which is in turn effective to cause radially inward compression of the collet sleeve 136 into gripping engagement and electrical contact with the exposed forward end portion 139 of the core electrode 114.

During such tightening of the sleeve 117 on the housing 116, the ferrule 156 is initially moved rearwardly within the sleeve 117 relative thereto to compress the O-ring gaskets 187 and 188 into sealing abutment with the internal surface of the sleeve 117 and with the outer conductive sheath 113 of the cable 112 until the washer 180 abuts the aforementioned shoulder 179.

It will now be seen that, in connector 110 shown in FIGS. 3 and 4, radially inward compression of the collet sleeve 136 onto the forward end portion 139 of the core electrode 114 is obtained solely as a result of radially inward compression of the sheath-gripping ferrule 156.

Having described the previously known connectors 10 and 110 shown in FIGS. 1, 2 and 3, 4 respectively, two particularly useful embodiments of a connector in accordance with this invention as shown in FIGS. 5, 6 and 7 of the accompanying drawings will now be described.

Referring first to the connector 210 shown in FIG. 5, it will be seen that this connector 210 includes a tubular metal housing generally indicated at 216 and a tubular plug bolt generally indicated at 217. It should perhaps be pointed out that, in accordance with a particularly useful feature of this invention, a plug bolt such as the plug bolt 217, is provided in distinction to the provision of a threaded sleeve such as the sleeves 17 and 117 already described herein. The plug bolt 217 includes a head 218 and a shank 290 and has an axial bore 225 extending therethrough for the free insertion of a coaxial cable thereinto.

The plug bolt 217 is threadedly received at 219 in the rearward end of the housing 216 and a resiliently compressible O-ring gasket 234 is disposed around the shank 290 of the plug bolt 217 to provide a seal between that plug bolt 217 and the housing 216.

The connector 210 also includes a radially inwardly compressible collet sleeve 236 which is integrally formed with a forwardly extending connector pin 237 which in turn is retained in fixed position within the connector 210 by a bushing generally indicated at 242 positioned in the forward end of the housing 216. In distinction to the corresponding bushings 42 and 142 already described, the bushing 242 is formed from two opposed cup-shaped members 291 and 292 as will readily be understood by reference to FIG. 5 of the drawings. At its rearward end, the collet sleeve 236 is hollow and is formed with one or more axially extending slots (not shown) in its wall and can be threaded or serrated in its inner surface 240 to permit its radially inward compression into gripping engagement and electrical contact with an exposed forward end portion of the core electrode of a coaxial cable (not shown), to which the connector is to be secured.

Forwardly of the rearward end of the collet sleeve 236, the housing 216 is provided with a rearwardly facing internal annular shoulder or abutment stop 293 which serves to limit forward axial movement of a resiliently and radially inwardly compressible and electrically insulating bushing generally indicated at 246. The bushing 246 is provided with an axial bore 247 within which a rearward end portion of the collet sleeve 236 is disposed. The bore 247 is flared outwardly at 248 for the purpose of guiding the forward end of a core electrode of a cable into that collet sleeve 236.

A sector 291 of the bushing 246 is cut away as will best be seen by reference to FIG. 6 to facilitate radially inward compression of the bushing 246 for a purpose which will be more readily understood as the description herein proceeds. The bushing 246 includes a radially extending and rearwardly facing surface 254 and a rearwardly facing annular and external frustoconical cam surface 294.

The connector 210 also includes a radially inwardly compressible and electrically conductive metal ferrule 256 having an axial bore usefully provided in its inner surface with a thread or serration to provide improved gripping engagement with the outer conductive sheath of a coaxial cable disposed therein. The ferrule 256 has an axially extending slot 261 in its peripheral wall to facilitate its radially inward compression into gripping engagement and electrical contact with the outer conductive sheath of a cable disposed therein. The ferrule 256 also is formed at its forward end with forwardly facing frusto-conical internal cam surface 295 for contiguous surface abutment with the rearwardly facing external frusto-conical cam surface 294 of the bushing 246. At its rearward end, the ferrule 256 is formed with rearwardly facing frusto-conical external cam surface 296 for contiguous surface abutment with a forwardly facing internal cam surface 266 of an annular thrust ring 264 disposed for axial movement within the housing 216 forwardly of the aforementioned thread 219.

In accordance with an optional but particularly useful feature of this invention, the thrust ring 264 is formed with an external thread 297 for threaded engagement with the internal thread 219 of the housing 216. With the provision of such a thread 297 of the thrust ring 264, that ring can be inserted into the housing 216 for free axial movement therein by screwing it into that housing after which time it is restricted against non-rotational rearward axial movement out of that housing 216. This is particularly advantageous in that it prevents accidental displacement of the thrust ring 264, the ferrule 256 and the bushing 246 in the event that the plug bolt 217 is completely removed or unscrewed from the rearward end of the housing 216.

In accordance with another useful feature of this invention, the plug bolt 217 of the connector 210 is formed in the forward end of its axial bore 225 with an axially extending annular seating 298 in which a resilient gasket seal 299, of rectangular or circular configuration, e.g., an O-ring, is positioned.

To secure the connector 210 to the forward end of a coaxial cable, such as the cables 12 and 112 already described herein, the forward end of the cable is initially prepared in exactly the same manner as that already described so as to provide an exposed forward end section of the core electrode of such a cable. The forward end of the cable is then inserted into the connector 210 until such exposed forward end portion of the core electrode is positioned within the collet sleeve 236 and with the forward end of the outer conductive sheath of the cable seated against the rearwardly facing surface 254 of the bushing 246. The plug bolt 217 is then screwed into the housing 216 and, during such screwing of the plug bolt 217, the gasket sleeve 299 is axially compressed and radially expanded to provide a moisture and dust barrier around the outer sheath of the cable.

Continued turning of the plug bolt 217 into the housing 216 causes the forward end of the shank 290 of the plug bolt 217 to abut the rearwardly facing radial surface of the thrust ring 264 to move that ring 264 axially forwardly. Such axial forward movement of the thrust ring 264 through co-action of the internal cam surface 266 thereof with rearwardly facing external cam surface 296 of the ferrule 256 causes ferrule 256 both to move axially forwardly and its rearward end to be compressed radially inwardly into gripping engagement and electrical contact with the outer sheath of the cable disposed within the connector.

Such forward movement of the ferrule 256, causes bushing 246 to be radially inwardly compressed, through co-action of the internal cam surface 295 of ferrule 256 and the rearwardly facing external cam surface 294 of the bushing 246 such that bushing 246 acts on the collet sleeve 236 to compress the collet sleeve into gripping engagement and electrical contact with the core electrode forward portion disposed therewithin. The outer surface 301 at the forward end of ferrule 256 is forced radially outwardly by the aforesaid co-action of internal cam surface 295 of the ferrule 256 and cam surface 294 of bushing 246 to tightly abut inner surface 303 of housing 216 and to effectively prevent ferrule 256 from rotating and twisting the coaxial cable squeezed thereby.

It will now be understood that, for the particular connector 210 in accordance with this invention as illustrated in FIGS. 5 and 6, tightening movement is transmitted from the sheath-engagement ferrule 256 thereof to the bushing 246 associated with the core electrode-gripping collet sleeve 236, in both the axial and the radial directions. It is also to be noted that the radially inward compression applied to the collet sleeve 236 through the surrounding bushing 246 is applied thereto in the forward direction and over a greater axial length than was the case for either of the previously known connectors 10 and 110 hereinbefore described.

Having completed the description of the connector 210 shown in FIGS. 5 and 6, the structure of the connector generally indicated at 310 in FIG. 7 will now be considered insofar as it differs from that of the connector 210. Referring therefore to FIG. 7, it will be seen that the connector 310 shown therein differs from the connector 210 only in regard to the structural components provided for transmitting the tightening forces from a radially compressible and electrically conductive sheath-gripping ferrule 356 thereof forwardly to the radially compressible and electrically insulating bushing 246 coaxially disposed around the radially compressible collet sleeve 236 of the connector and in regard to the provision of a resiliently compressible O-ring gasket 399 for providing a seal between the outer conductive sheath 313 of the cable 312 and the connector 310. In particular, it will be noted that the O-ring gasket 399 is positioned within an annular recess 398 provided for this purpose in the forwardly facing end surface of the shank 390 of the plug bolt 317. Apart from this particular difference, the structure of the plug bolt 317 is identical to that of the plug bolt 217 already described herein.

The resiliently and radially inwardly compressible bushing 246 of the connector 310 is identical to the bushing 246 of the connector 210 but, instead of directly abutting a cam surface formed on the forward end of the sheath-gripping ferrule 356, the rearwardly facing external cam surface 294 of the bushing 246 of the connector 310 is disposed in surface abutment with a forwardly facing internal cam surface 400 of a thrust collar generally indicated at 401 which is also provided with a rearwardly facing internal cam surface 402 which in turn is in surface abutment with a forwardly facing external cam surface 403 of the sheath-gripping ferrule 356.

Since the manner in which the connector 310 is used is generally identical to that of the connector 210 already described, it is considered to be unnecessary to describe such manner of use in further detail herein. It should be noted, however, that the structure shown in FIG. 7 is operative for transmitting radially inward compressive movement from the sheath-gripping ferrule 356 to the collet sleeve 236 of the connector via collar 401 and bushing 246. Axial forward movement of ferrule 356 causes collar 401 to move forward and radially outwardly under the co-action of cam surfaces 402,403 and 400,294 such that the outer surface 410 of collar 401 tightly abuts the inner surface 303 of housing 216 to effectively prevent ferrule 356 from rotating while bushing 246 is compressed to tightly grip collet sleeve 236. In this respect, the connector 310 is more similar to the previously known connector 10 of FIGS. 1 and 2 but differs therefrom in that the radially compressive forces are applied to the core electrode-gripping collet sleeve over a greater axial length and in the forward direction rather than in the rearward direction.

It will be understood that numerous modifications and variations may be made to the structures of the connectors 210 and 310 hereinbefore described without departing from the scope of the invention. In particular, it can be noted that means such as a fixed key disposed in an axially extending keyway formed, for example, in the outer peripheral surface of the ferrule 256 of the connector 210 of FIG. 5 may be provided to prevent rotation of that ferrule during tightening of the connector on the end of a coaxial cable. Alternatively or additionally, means such as a low friction washer or even a bearing may be incorporated to reduce the frictional forces between the forward end of the plug bolt 217 and the rearwardly facing surface of the thrust ring 264 of that connector.

Claims

What I claim as new and desire to protect by Letters Patent of the United

1. A connector for securement to a coaxial cable having a core electrode and an outer conductive sheath and which connector comprises a housing, a radially inwardly compressible and electrically conductive ferrule disposed within said housing for both forward movement therein and radially inward compression of the rearward end of the ferrule into gripping engagement and electrical contact with the outer conductive sheath of a coaxial cable inserted into said connector, means movably mounted on said housing for causing said forward movement and said radially inward compression of said electrically conductive ferrule, and a radially inwardly compressible and electrically conductive collet sleeve mounted generally axially within said housing and electrically insulated from said electrically conductive ferrule, for receiving an exposed forward end portion of the core electrode of the coaxial cable inserted into said connector and having associated therewith a rearwardly facing external cam surface for contiguous surface abutment with a forwardly facing internal cam surface integral with the forward end of said electrically conductive ferrule whereby, on forward movement and radially inward compression of said electrically conductive ferrule into gripping engagement and electrical contact with the outer conductive sheath of the coaxial cable, resulting forward movement of said forwardly facing internal cam surface associated with the said forward end of said electrically conductive ferrule is operative, by virtue of its abutment with said rearwardly facing external cam surface associated with said collet sleeve, to cause outward abutment of the said forward end of the ferrule against the housing to prevent rotation of the ferrule and to provide radially inward compression of said collet sleeve into said gripping engagement and electrical contact with the core electrode of the

2. A connector as claimed in claim 1 which additionally comprises an axially compressible and radially expansible sealing member disposed within said housing around the outer conductive sheath of the coaxial cable inserted into said connector plug and in which said means for causing said forward movement and said radially inward compression of said electrically conductive ferrule is also adapted conjointly to cause axial compression and radial expansion of said sealing member into sealing engagement with the outer conductive sheath of the cable and with said

3. A connector as claimed in claim 1 which comprises a radially compressible and electrically insulating bushing coaxially disposed around said collet sleeve within said housing and having said rearwardly facing external cam surface provided thereon and in which said forwardly facing internal cam surface is provided on a forward end of said electrically

4. A connector for securement to a coaxial cable having a core electrode and an outer conductive sheath and which connector comprises: a tubular body; a tubular plug bolt threadedly secured to said tubular body at a rearward end thereof for axial threaded movement relative thereto in a forward direction for securing a coaxial cable within said connector; a radially inwardly compressible and electrically conductive collet sleeve mounted generally axially within said body for receiving an exposed forward end portion of the core electrode of the coaxial cable inserted into said connector and adapted to be compressed radially inwardly into gripping engagement and electrical contact with such forward end portion of the core electrode of the cable; a radially inwardly compressible bushing coaxially disposed within said tubular body about said collet sleeve and having a rearwardly facing external cam surface; a stop means formed within said tubular body forwardly of said radially inwardly compressible bushing and adapted to be abutted thereby to restrict forward axial movement of said radially inwardly compressible bushing within said tubular body; a radially compressible and electrically conductive ferrule disposed within said tubular body for axial forward movement therewithin with the cable disposed axially therewithin, adapted for radially inward compression into gripping engagement and electrical contact with the outer conductive sheath of such a cable, and having integrally formed therewith a rearwardly facing external cam surface and a forwardly facing internal cam surface for contiguous surface abutment with said rearwardly facing external cam surface of said radially inwardly compressible bushing; and a forwardly facing internal cam surface associated with said tubular plug bolt for conjoint forward movement therewith in contiguous surface abutment with said rearwardly facing external cam surface associated with said electrically conductive ferrule, whereby, on forward axial movement of said tubular plug bolt relative to said tubular body, resulting forward movement of said forwardly facing internal cam surface associated with said tubular plug bolt in contiguous surface abutment with said rearwardly facing external cam surface associated with said electrically conductive ferrule causes both forward movement and radially inward compression of said ferrule into gripping engagement and electrical contact with the outer conductive sheath of the cable and whereby forward movement of said forwardly facing internal cam surface associated with said electrically conductive ferrule in contiguous surface abutment with said rearwardly facing external cam surface of said radially inwardly compressible bushing causes radially inward compression of said bushing in turn radially inwardly to compress said collet sleeve into gripping engagement and electrical contact with the exposed forward

5. A connector as claimed in claim 4 which additionally comprises a thrust ring disposed within said tubular body for forward axial movement therewithin and having said forwardly facing internal cam surface associated with said tubular plug bolt integrally formed therewith as well as having a rearwardly facing and radially extending surface for abutment with a forwardly facing and radially extending surface of said tubular

6. A connector as claimed in claim 5 which additionally includes an annular axially compressible and radially resiliently expansible sealing member disposed between said tubular plug bolt and said thrust ring and adapted radially to expand on forward axial movement of said tubular plug bolt relative to said tubular body thereby to provide a generally fluid-tight seal between said tubular plug bolt and the outer conductive sheath of the

7. A connector as claimed in claim 5 in which said rearwardly facing external cam surface of said radially inwardly compressible bushing comprises a rearwardly facing and radially inwardly tapering external frusto-conical surface, in which said forwardly facing internal cam surface of said electrically conductive ferrule is a forwardly facing and radially outwardly expanding internal frustoconical surface adapted for contiguous surface abutment with said frusto-conical surface of said radially inwardly compressible bushing, in which said rearwardly facing external cam surface of said electrically conductive ferrule is a rearwardly facing and radially inwardly tapering external frusto-conical surface, and in which said forwardly facing internal cam surface of said thrust ring is a forwardly facing and radially outwardly expanding internal frusto-conical surface adapted for contiguous surface abutment with said external frusto-conical surface of said electrically conductive

8. A connector as claimed in claim 7 in which said tubular plug bolt is externally threaded for threaded engagement with a corresponding internal thread formed within said tubular body in proximity to said rearward end thereof and in which said thrust ring is externally threaded for threaded engagement with said internal thread formed within said tubular body during insertion of said thrust ring into said tubular body and for sliding axial movement within said tubular body forwardly of said internal thread formed therein in abutment with both said forwardly facing surface of said tubular plug bolt and said rearwardly facing and radially inwardly tapering external frusto-conical surface of said electrically conductive ferrule, whereby free non-rotational rearward axial movement of said thrust ring out of said tubular body when said tubular plug bolt is

9. A connector as claimed in claim 8 in which said electrically conductive collet sleeve and said electrically conductive ferrule are each formed with an internally disturbed surface for gripping engagement with the exposed forward end portion of the core electrode and with the conductive outer sheath respectively of the coaxial cable disposed within said plug

10. A connector for securement to a coaxial cable having a core electrode and an outer conductive sheath and which connector comprises: a tubular body; a tubular plug bolt threadedly secured to said tubular body at a rearward end thereof for axial threaded movement relative thereto in a forward direction for securing a coaxial cable within said connector; a radially inwardly compressible and electrically conductive collet sleeve mounted generally axially within said body for receiving an exposed forward end portion of the core electrode of the coaxial cable inserted into said connector and adapted to be compressed radially inwardly into gripping engagement and electrically contact with such forward end portion of the core electrode of the cable; a radially inwardly compressible bushing coaxially disposed within said tubular body about said collet sleeve and having a rearwardly facing external cam surface; a stop means formed within said tubular body forwardly of said radially inwardly compressible bushing and adapted to be abutted thereby to restrict forward axial movement of said radially inwardly compressible bushing within said tubular body; a radially compressible and electrically conductive ferrule disposed within said tubular body for axial forward movement therewithin with the cable disposed axially therewithin, adapted for radially inward compression into gripping engagement and electrical contact with the outer conductive sheath of such a cable, and having integrally formed therewith a rearwardly facing external cam surface and a forwardly facing external cam surface; a thrust collar having integrally formed therewith a forwardly facing internal cam surface for contiguous surface abutment with said rearwardly facing external cam surface of said radially inwardly compressible bushing, which thrust collar also has integrally formed therewith a rearwardly facing internal cam surface for contiguous surface abutment with the forwardly facing external cam surface integrally formed with said electrically conductive ferrule, a thrust ring disposed within said tubular body for forward axial movement therewithin and having a forwardly facing internal cam surface in contiguous surface abutment with said rearwardly facing external cam surface of said electrically conductive ferrule and a rearwardly facing and radially extending surface for abutment with a forwardly facing and radially extending surface of said tubular plug bolt whereby, on forward axial movement of said tubular plug bolt relative to said tubular body, resulting forward movement of said forwardly facing internal cam surface of said thrust ring in contiguous surface abutment with said rearwardly facing external cam surface of said electrically conductive ferrule causes both forward movement and radially inward compression of said ferrule into gripping engagement and electrical contact with the outer conductive sheath of the cable and whereby forward movement of said forwardly facing external cam surface of said electrically conductive ferrule in contiguous surface abutment with said rearwardly facing internal cam surface of said thrust collar causes both outward abutment of said thrust collar against the tubular body to prevent rotation of the ferrule and forward movement of the thrust collar forwardly facing internal cam surface in abutment with the rearwardly facing external cam surface of the radially inwardly compressible bushing to compress said collet sleeve radially inwardly into gripping engagement and electrical contact with the exposed forward end

11. A connector plug as claimed in claim 10 in which each said cam surface is in the form of a generally frusto-conical cam surface.