Abstract:
The present invention provides a connector used to interconnect a hard-line coaxial cable to an equipment port. The connector of the present invention essentially comprises a main connector body in which the various connecting and sealing members are housed, and a compression body attached to the connector body for axial, sliding movement between first and second terminal positions relative to the connector body. The port side of the connector includes a conductive pin extending axially outwardly therefrom that is adapted to be inserted into the port provided in the equipment box, and an axially extending bore is formed though the distal end (cable side) of the connector and compression bodies for receiving the central conductor of the hard-line cable therein.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to co-axial cable connectors, and more particularly to such connectors used with hard-line co-axial cables. 
     Co-axial cable is a typical transmission medium used in communications networks, such as a CATV network. The cables comprising the transmission portion of the network are typically of the “hard-line” type, while those used to distribute the signals into residences and businesses are typically “drop” connectors. The principal difference between hard-line and drop cables, apart from the size of the cables, is that the hard-line cables include a rigid or semi-rigid outer cable (typically covered with a weather protective jacket) that effectively prevents radiation leaking and protects the inner conductor and dielectric, while the drop cables include a relatively flexible outer conductor, typically braided, that permits their bending around obstacles between the transition or junction box and the location of the device to which the signal is being carried, i.e., a television, computer, and the like. Drop cables are less effective than hard-line cables at preventing radiation leakage. Hard-line conductors, by contrast, generally span considerable distances along relatively straight paths, thereby greatly reducing the need for a cable&#39;s flexibility. Due to the differences in size, material composition, and performance characteristics of hard-line and drop cables, there are different technical considerations involved in the design of the connectors used with these types of cables. 
     In constructing and maintaining a network, such as a CATV network, the transmission cables are often interconnected to electrical equipment that conditions the signal being transmitted. The electrical equipment is typically housed in a box that may be located outside on a pole, or the like, or underground that is accessible through a cover. In either event, the boxes have standard ports to which the transmission cables may be connected. In order to maintain the electrical integrity of the signal, it is critical that the transmission cable be securely interconnected to the port, and without disrupting the ground connection of the cable. This requires a skilled technician to effect the interconnection. 
     A typical type of interconnect device used to connect a transmission cable to an equipment port is of the threaded type. The technician must prepare the cable in the standard manner, i.e., stripping the various layers of the cable to their predetermined distances and furrowing out the dielectric material over a predetermined distance in order to bottom out the inner conductor until it is seized by the conductive pin that will carry the signal through the port, and use a wrench to provide torque that will radially compress and seal portions of the connector into the outer jacket of the transmission cable. Such types of connector rely heavily on the skill of the technician in applying the proper amount of torque to effect the connections, thereby making reliability of signal integrity a concern. 
     In addition to the need for a skilled technician in effecting the connection between the transmission cable and the equipment port, such threaded connectors also require that the transmission cable be separated from the connector the equipment housed in the box needs to be serviced or maintained. It also is difficult to fit a wrench into the space provided by many equipment ports, thereby making the technician&#39;s job that uses threaded connectors even more difficult. 
     Another type of standard connector used with transmission cables are of the crimping type. With crimp connectors, the technician uses a crimping tool that radially surrounds the connector after the cable has been bottomed out therein, and radially crimps the connector body into engagement with the cable&#39;s outer jacket. While such connectors eliminate the difficulties associated with the threaded connectors, the crimping action often produces inconsistent electrical connection between the connector and the cable, is less effective at preventing moisture migration, and also degrades the cable&#39;s outer conductor, thereby creating signal losses that ultimately reduce the quality of the signal being transmitted. 
     A compression type connector usable on hard-line cables is disclosed in U.S. Pat. No. 6,331,123. Compression connectors utilize a compression member that is axially slidable into the connector body for radially displacing connecting and sealing members into engagement with the hard-line cable&#39;s outer conductor. A compression tool that slides the compression body into the connector is utilized by the technician to effect the connection, and due to the physical constraints of the compression member and connector body, it is impossible for the technician to use too much force to effect the interconnection. Thus, compression connectors eliminate the assembly drawbacks associated with threaded, and to some degree, crimp type connectors. 
     It is a principal object and advantage of the present invention to provide a compression type connector for use on hard-line cables. 
     It is another object and advantage of the present invention to provide a compression type connector that reliably effects interconnection between a hard-line cable and an equipment port. 
     It is an additional object and advantage of the present invention that reduces technician errors associated with connecting a hard-line cable to an equipment port. 
     It is a further object and advantage of the present invention to provide a compression type connector for use with hard-line cables that may be inexpensively manufactured with a minimum of waste material. 
     Other objects and advantages of the present invention will in part be obvious, and in part appear hereinafter. 
     SUMMARY OF THE INVENTION 
     In accordance with the foregoing objects and advantages, the present invention provides a connector used to interconnect a hard-line co-axial cable to an equipment port. The connector of the present invention essentially comprises a main connector body in which the various connecting and sealing members are housed, and a compression body attached to the connector body for axial, sliding movement between first and second terminal positions relative to the connector body. The port side (also referred to herein as the “proximal” end) of the connector includes a conductive pin extending axially outwardly therefrom that is adapted to be inserted into the port provided in the equipment box, and an axially extending bore is formed through the distal end (cable side) of the connector and compression bodies for receiving the central conductor of the hard-line cable therein. A collet electrically connected to the conductive pin seizes the central conductor when it is fully inserted through the axial bore, thereby electrically interconnecting the conductor to the conductive pin that ultimately carries the signal to/from the equipment mounted in the box. A nut is rotatably attached to the proximal end of the connector body and serves to connect the connector body to the equipment port. 
     After preparing the cable using industry standard preparation tools, the central conductor is fully inserted in the axial bore, the outer conductor of the hard-line cable is positioned annularly between a mandrel that is housed within the connector body and various clamping and sealing members. An industry standard compression tool may then be used by a technician to axially slide the compression body into the connector body. As the compression body slides into to the connector body its ramped, leading face engages a correspondingly ramped surface of a clamping and sealing member. The co-acting ramped surfaces cause the clamping and sealing member to deflect radially inwardly until it contacts the outwardly facing surface of the outer conductor (and possibly a potion of the jacket coating the outer conductor). 
     The proximal end of the compression body then engages an RF seal driver (that may be an integral part of the clamping and sealing member), and drives it axially within the connector body. As the RF seal driver slides axially in the connector body (as a result of being pushed by the compression body), its proximal end surface engages the distal end surface of the RF seal and drives the RF seal axially. The RF seal includes a portion of its outwardly facing surface that is ramped, and as it is forced axially, the ramped portion of the RF seal engages a correspondingly ramped surface formed on the inwardly facing surface of the connector body. The ramped surface on the connector body forces the RF seal radially inwardly towards the outwardly facing surface of the hard-line cable&#39;s outer conductor. Upon termination of the axial movement of the compression body, the hard-line cable&#39;s outer conductor is sandwiched between the RF seal and the mandrel, and the jacket coating the outer conductor is sandwiched between the clamping and sealing member and the mandrel. 
     Alternatively, the proximal end surface of the compression body may serve as the RF seal driver. In this arrangement, the proximal end of the compression body pass entirely over the clamping and sealing member and engages the distal end surface of the RF seal in order to drive it axially. Alternate embodiments of the RF seal are also disclosed, as is connector body having a port side that is offset 90 degrees relative to its cable side. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood and more fully appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a perspective view of a preferred embodiment of a hard-line co-axial cable connector; 
     FIG. 2 is an exploded perspective view thereof; 
     FIGS. 3 a  and  3   b  are a cross-sectional views thereof taken along line  3 — 3  of FIG. 1, showing the connector in its uncompressed and compressed positions, respectively; 
     FIG. 4 is a perspective view of the RF seal of the preferred embodiment; 
     FIG. 5 is a perspective view of the clamping member of the preferred embodiment; 
     FIG. 6 is a cross-sectional view of the clamping member taken along line  6 — 6  of FIG. 5; 
     FIG. 7 is a perspective view of the connector body of the preferred embodiment; 
     FIG. 8 is a perspective view of the compression body of the preferred embodiment; 
     FIG. 9 is a cross-sectional view of the compression body taken along line  9 — 9  of FIG. 8; 
     FIG. 10 is a perspective view of the collet assembly of the preferred embodiment; 
     FIG. 11 is a cross-sectional view of the collet assembly taken along line  11 — 11  of FIG. 10; 
     FIG. 12 is a perspective view of the mandrel of the preferred embodiment; 
     FIG. 13 is across-sectional view of the mandrel taken along line  13 — 13  of FIG. 12; 
     FIG. 14 is a perspective view of a second embodiment of the present invention; 
     FIG. 15 is an exploded perspective thereof; 
     FIG. 16 is a cross-sectional view thereof taken along line  16 — 16  of FIG. 14; 
     FIG. 17 is a perspective view of a third embodiment of the present invention; 
     FIG. 18 is a cross-sectional view thereof taken along line  18 — 18  of FIG. 17; 
     FIG. 19 is a perspective view of a fourth alternate embodiment of the present invention; 
     FIG. 20 is an exploded perspective thereof; 
     FIG. 21 is a cross-sectional view thereof taken along line  21 — 21  of FIG.  19 . 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawing figures, wherein like reference numerals refer to like parts throughout, there is seen in FIG. 1 a connector, designated generally by reference numeral  10 , for use in interconnecting a hard-line co-axial cable  12  to a port  14  of an equipment box  16 . Connector  10  generally comprises a body  18  that extends along longitudinal axis X—X, a compression member  20  connected to body.  18  for axial movement relative thereto between first (uncompressed, See FIG. 3 a ) and second (compressed, See FIG. 3 b ) positions, and a coupling nut  22  for interconnecting body  18  to port  14 . 
     Co-axial cable  12  is a conventional hard-line cable, such as a QR, P 1 , P 2 , P 3 , or TX type cable, among other industry standard cables, comprising a central conductor  24 , typically a signal carrying conductor, that is radially surrounded by a layer of dielectric material  26 , such as polyethylene, polytetrafluoroethylene, and the like, an outer conductor  28 , typically a ground conductor, radially surrounding the dielectric material  26  and extending co-axially with central conductor  24 , and an outer jacket  30  that surrounds outer conductor  28  and protects it from inclement weather, among other things. Hard-line cable is commonly used as the distribution medium in a CATV network, and is well understood in the art. 
     Connector  10  further comprises a collet assembly  32  co-axially positioned within body  18 . Collet assembly  32  includes a cable seizing element  34  composed of an electrically conductive material, such as brass, that includes a central opening  36  through which central conductor  24  may pass with an interference fit, and a contact pin  38  electrically connected to and extending axially from seizing element  34  towards the proximal end (port side) of connector  10 . Contact pin  34  carries the signal from central conductor  24  through port  14  to the equipment contained within box  16 . 
     Collet assembly  32  is maintained in position within body  18  by a tubular insulator that includes a flange  42  that engages the outwardly facing, proximal end surface of seizing member  34 , and a distal lip portion  44  that is securely annularly engaged with the outwardly facing surface of seizing member  34 . The remainder of insulator  40  extends axially towards the proximal end of body  18 . 
     To maintain insulator  40  in position within body  18 , and to securely interconnect coupling nut  22  to body  18 , a retaining nut  46  is used. Retaining nut  46  includes a terminal leg  48  that is tightly sandwiched between the proximal end portion  50  of body  18  and insulator  40 , thereby maintaining insulator  40  in fixed relation relative to body  18 . A flanged lip  52  at the distal end of terminal leg  48  engages the inner surface of proximal end portion  50  to prevent inadvertent dislodgement of retaining nut  46  from body  18 . 
     An intermediate leg  54  of retaining nut  46  is of a greater diameter than, and extends proximally from terminal leg  48 , and engages the outwardly facing surface of body  18  at the neck interface of the two leg portions. Finally, the proximal end  56  of retaining nut  46  is of a diameter greater than that of intermediate leg  54 , and engages an inner flange  58  formed in coupling nut  22  to prevent nut  22  from becoming disassociated from body  18 , as further described below. 
     During assembly, the distal region  60  of coupling nut  22  is slid over the proximal end portion  50  and intermediate region  62  of body  18 . Due to intermediate region  62  being of a larger diameter than proximal end portion  50 , an annular space exists between distal region  60  and proximal end portion  50 . To seal out moisture and other contaminants from migrating between coupling nut  22  and proximal end portion  50 , an O-ring  64  is sealingly positioned therebetween (ring  64  actually sits in a notch formed in the outwardly facing surface of proximal end portion  50 ). The interconnection between coupling nut  22  and body  18  is tight enough to maintain a predominantly sealed connection, but loose enough to permit coupling nut  22  to be rotated about axis X—X independent of body  18 , and threaded onto or off of port  14 . 
     Returning to connector  10 , it further comprises a conductor centering guide  66  annularly positioned around the open end  36  of collet assembly  34 , and that includes an inwardly tapering surface  68  that guides central conductor  24  through opening  36  and into seizing member  34 . Centering guide  66  extends radially outwardly from seizing member  34  into engaged relation with the inner surface of body  18 , thereby fixing its position relative to body  18 . 
     Extending distally from centering guide  66  is a tubular mandrel  70 . Centering guide  66  and mandrel  70  are illustrated in the drawing figures as being an integral unit, but it should be understood that they could be manufactured as separate components as well. 
     When compression member  20  is in its uncompressed position, connector  10  further comprises an RF seal  72  positioned co-axially with, and in annularly spaced relation to the outwardly facing surface of mandrel  70 , and a clamping member  74  also positioned co-axially with, and in annularly spaced relation to the outwardly facing surface of mandrel  70 . RF seal  72  becomes radially compressed into sealing engagement with the outer surface of outer conductor  28 , and clamping member  74  becomes radially compressed into clamping relation to the outer surface of jacket  30  when compression member  20  is axially moved to its second (fully compressed) position, as will be described in greater detail hereinafter. 
     With reference to FIG. 4, RF seal  72  is composed of a conductive material, such as brass, formed in a ring with a series of annularly spaced notches  76  removed therefrom which define annularly spaced segments  78 . Segments  78  include a distal surface that ramps upwardly towards the distal end of body  18 . When placed in contacting relation with outer conductor  28 , RF seal  72  sandwiches the conductor between itself and mandrel  70 , and also prevents undesirable levels of RF radiation from leaking from cable  12 . 
     With reference to FIGS. 5-6, clamping member  74  is composed of a nonconductive material, such as DELRIN® (although it could be composed of any relatively rigid thermoplastic or a conductive material without affecting the performance of connector  10 ), and includes a proximal region  80  that has a surface  82  that is correspondingly ramped relative to segments  78 , and a distal region  84  that ramps downwardly towards the distal end of body  18 . The clamping surface  86  of clamping member is relatively flat, although it could be toothed, wavy, or of some other geometry, and is adapted to engage jacket  30  (although it may also engage a portion of conductor  28 ) when compression member  20  is moved to its fully compressed position. Clamping member  74  assists in preventing cable  12  from becoming disengaged from body  18 , thereby assisting in maintaining good signal transmission between cable  12  and port  14 . 
     With reference to FIGS. 8-9, compression member  20  comprises a wedge shaped piece of durable material, such as brass, that includes a tapering inner surface  88  extending inwardly from its proximal end and that corresponds with the ramped surface of distal region  84 . The proximal end of compression member  20  is press fit into the distal end of body  18  with surface  88  positioned in contacting relation to the outwardly facing surface of distal region  84 . An industry standard compression tool (such as industry standard RG7/11 with which The Ripley CAT-AS or CAT-AS-EX or EX7/11CAT compression tools all comply) is used to axially slide compression member  20  from its first (uncompressed) to its second (fully compressed) position, as described below. 
     In operation, a technician would first prepare cable  12  using industry standard preparation tools, such as the Ripley CST-320/7CQRF tool, in a traditional manner by coring out a predetermined amount of dielectric material  26  from between central conductor  24  and outer conductor  28 , stripping a predetermined amount of jacket off of outer conductor  28 , and removing a predetermined amount of outer conductor  28 . The technician would then insert the central conductor through the distal end of body  18  until it is bottomed out in seizing member  34 , which simultaneously positions outer conductor  28  between mandrel  70  and RF seal  72 . A portion of uncovered outer conductor  28 , as well as a portion of conductor  28  with jacket  30  is also positioned between mandrel  70  and clamping member  74 . 
     A compression tool may then be used by the technician to engage the uncompressed compression member  20 . The technician actuates the compression tool such that compression member  20  is axially moved towards and into body  18 . As compression member  20  axially moves into body  18 , its inner surface  88  engages the ramped surface of distal region  84 , while the outwardly facing surface of compression member  20  is bounded by the inner surface of body  18 . Inner surface  88  therefore exerts an inwardly directed radial force to clamping member  74 , thereby causing clamping surface  86  to engage outer conductor  28 /jacket  30 . The axial movement of compression member  20  also axially drives clamping member into engagement with RF seal  72 . As the ramped surface at the proximal end of clamping member  74  engages correspondingly ramped distal surface of segments  78 , the opposing ramped surface of segments  78  engage the ramped inwardly facing surface of connector body  18  which, in turn, exert an inwardly directed radial force to RF seal  72 . Once compression member  20  reaches it second (fully compressed) position, RF seal  72  is securely engaged with outer conductor  28 , and clamping member  74  is in secure engagement with outer conductor  28 /jacket  30 , as illustrated in FIG. 3 b . If maintenance needs to be performed to box  12 , the technician merely disconnects connector  12  therefrom by unthreading coupling nut  22 . There is no need for the technician to remove cable  12  from body  18 , thereby accelerating the rate at which repair and maintenance can be completed. 
     An alternate embodiment of connector  10 , designated  100 , is illustrated in FIGS. 14-16. Most of the elements between connectors  10  and  100  are virtually identical and will therefore be represented by common reference manuals. In addition, the operation/functionality of connector  100  is virtually identical to the operation/functionality of connector  10 , and will therefore not be repeated. 
     The principal distinctions between connectors  10  and  100  are that connector  100  includes an RF seal  102  comprising a split ring with several axially spaced rows of circumferentially spaced teeth  104  protruding from its inwardly facing surface, a clamping member  106  that includes a relatively flat proximal end surface  108  that is designed to engage and axially drive RF seal  102 ; and compression member  110  includes a distal end  112  that is of a diameter greater than that of body  18 , thereby serving as a compression stop. 
     RF seal  102  includes teeth  104 , and a ramped portion  114  formed on its outer surface that abuts a correspondingly ramped surface  116  of body  18 . As the proximal end of clamping member  106  engages and axially drives RF seal  102 , the ramped surface  114  forces RF seal  102  radially inward and into engaging relation with outer conductor  28 . 
     When compression member  110  is moved to its second position, its flanged distal end  112  comes into abutting relation with the distal end of body  18 . To seal out moisture from infiltrating between body  18  and compression member  110 , an O-ring  118  is sealingly positioned between the two. 
     In addition, due to the shape of clamping member  106 , an O-ring  120  is disposed in an annular notch formed therein, and that it is positioned between compression member  110  and clamping member  106  to prevent migration of moisture therebetween. 
     Referring now to FIGS. 17-18, another alternate embodiment is illustrated. Connector  200  includes many common connecting elements as connectors  10  and  100 , all of which will not be described in further detail and which will be represented by common reference numerals. 
     Connector  200  includes the same RF seal? 102  as used with connector  100 . However, as opposed to an inner surface of body  18  being the radial driving member, connector  200  includes a pair of flanged bushings  202 ,  204  that are securely positioned within body  18  on opposite sides of RF seal  102 . The flange  206  of bushing  202  abuts a shoulder  208  formed on the interior surface of body  18 , while the flange  210  of bushing  204  abuts a tubular compression guide  212  when compression member  110  is uncompressed. Tubular compression guide  212  is co-axially positioned within body  18  and is annularly spaced relation to mandrel  70 . 
     Compression member  20  includes a serrated compression leg  214  that is slidingly positioned between the interior surface of body  18  and the outer surface of tubular compression guide  212 . The serrations  216  on leg  214  extend rearwardly to assist in preventing rearward movement of compression member  20 . 
     In operation, as compression tool (not shown) forces compression member  20  axially into body  18 , the leading edge of leg  214  engages the flange  210  of bushing  204  and drives it axially. The end of bushing  204  then engages the distal ramped surface  218  of RF seal  102 , exerting both an axial force as well as a radial force to RF seal  102 . As a consequence of the axial force, the proximal ramped surface  220  of RF seal engages and is driven radially inward by the end of bushing  202 . When compression member  20  reaches its fully compressed position, the teeth  104  of RF seal are sealingly engaged with outer conductor  28 . 
     With reference to FIGS. 19-21, an alternate embodiment illustrating a connector  300  that is useful for interconnecting to ports that are either angularly offset relative to the direction in which cable  12  is extending, or that include impediments that otherwise obstruct a cable&#39;s access to the port. Body  302  of connector  300  includes a distal region (cable side)  304  that extends along axis X—X (co-axial with cable  12 ), and a proximal region (port side)  306  that extends at a 90 degree angle relative to distal region  304  along an axis Y—Y. 
     The majority of cable connecting and sealing elements are essentially the same as the ones used with connector  100 , and are contained within distal region  304 . A collet retainer  305  is securely positioned within body distal region  304  and in abutting relation to the proximal end surface of mandrel  70  and in radially surrounding relation to said collet assembly  34 . The 90 degree transition between distal region  304  and proximal region  308  is made by a contact pin  308  that extends from collet  309  that is positioned within distal region  304  and through insulator  310  that extends along axis Y—Y in proximal region  308 , and ultimately through coupling nut  22 . 
     While a preferred and several alternate embodiments of the present invention have been illustrated and described in detail, it will be apparent that various changes may be made in the discloded embodiment without departing from the scope and spirit of the invention, as define in the appended claims.