This invention relates generally to electrical connectors, and more specifically to cable connector assemblies for use with shielded cables having metallized braids.
Some electrical systems include shielded cable assemblies for transmitting electrical signals. Conductive metallized braids are coupled to the cable and surround the signal conductors in the cable for shielding purposes, and the metallized braids are connected to shielding features of connectors and components which ultimately provide a conductive path to ground. The metal braids of the cables, however, tend to complicate termination of the cables to connectors, and also complicate interconnection of the cables with other electrical components.
In systems of this type, connectors for shielded cables often include conductive metal shells, and some conventional metal shells include integral ferrule surfaces formed therewith which aid in connecting the cable braid to the shells. The cable braid is extended over the ferrule surfaces of the shells, and outer ferrule elements are attached over and crimped to the cable braid, thereby trapping the cable braid between the ferrule surfaces of the shell and the outer ferrule elements. While a satisfactory mechanical and electrical connection between the cable braid and the shells may result in such a construction, the ferrule surfaces of the shells are vulnerable to being damaged during assembly of the connector. Damage to the ferrule surfaces can compromise the performance of the cable connector and present reliability and performance issues, or cause the cable connector to be scrapped altogether, thereby reducing manufacturing efficiency and raising the costs of production.
Further, some electrical cables include a large conduit with a large number of conductors therein, and terminating the cable conductors to a connector and successfully connecting the cable braid to the shell is difficult. For example, at least one known connector is configured for attachment to as many as forty cable conductors. In such circumstances, the cable can become difficult to handle when the cable connector is installed, thereby increasing the risk that the ferrules will be damaged as the connector assembly is assembled.
According to an exemplary embodiment, a cable connector assembly comprises a ferrule assembly configured for attachment to a cable braid, and a resilient contact element surrounding an end of the ferrule assembly.
Optionally, a retaining band at one end of the ferrule assembly clamps the ferrule assembly to the cable braid. A radial groove may be provided in the cable assembly, and the resilient contact element is located in the radial groove. The ferrule assembly may be fixedly mounted to the conductive shell to prevent rotation of the ferrule assembly with respect to the shell, and the ferrule assembly may comprise a 90° bend. A conductive shell may be provided, and the conductive shell may be configured to compress the resilient contact element. The resilient contact element may comprise a canted coil spring.
According to another exemplary embodiment, a cable connector assembly comprises a conductive shell, and a ferrule assembly configured for attachment to a cable braid. The ferrule assembly extends from the conductive shell, and a compressible contact element encircles the ferrule assembly within the conductive shell. The contact element establishes an electrical connection to the shell when compressed.
According to still another exemplary embodiment, a cable connector assembly comprises first and second conductive shell elements, and each of the first and second conductive shells comprise an arcuate slot having a curved engagement surface. A ferrule assembly comprises first and second ferrule elements configured to attach to a cable braid, and the ferrule assembly comprises a radial groove. A resilient contact element extends circumferentially on the ferrule assembly within the radial groove, and the first and second shell elements compress the resilient contact element when the contact element is inserted into the slot and when the first and second shell elements are fastened together.
As shown in
The ferrule assembly 102 is attached to a conductive metallized braid 112 of a cable 114 in the manner explained below. The ferrule assembly 102 is received within a first compartment 116 defined by the upper and lower shells 106, 108 when the cable connector assembly 100 is assembled. The cable connector 104 is electrically connected or terminated to conductors in the cable 114, and the cable connector 104 is received in a second compartment 118 defined by the upper and lower shells 106, 108 when the connector assembly 100 is assembled.
In an exemplary embodiment, the cable connector 104 is a known connector which is mechanically and electrically connected or terminated to conductors in the cable 114 in a known manner. As such, and in an exemplary embodiment, the cable connector 114 provides interconnection of high-speed, low-voltage, differential signals between the cable 114 and a backplane connector (not shown in
In an exemplary embodiment, each of the upper and lower shells 106, 108 are fabricated from a conductive material, such as die cast metal, and the shells 106 and 108 form a protective enclosure about the ferrule assembly 102 and the cable connector 104 when the shells 106 and 108 are coupled to one another. The upper and lower shells 106 and 108 are generally rectangular in shape and are sized and dimensioned to securely receive and retain the ferrule assembly 102 and the connector 104. The upper and lower shells 106 and 108 are fitted over one another and mechanically connected to one another with known fastener elements 120, such as screws or rivets. The upper and lower shells 106, 108 are formed with mounting flanges 122 which receive mounting fasteners 124, such as jack screws shown in
The upper shield 106 includes shield retaining projections 125 adjacent a forward end 126 thereof. Each of the upper and lower shells 106, 108 include a curved or arcuate slot 127 which accommodates a portion of the ferrule assembly 102. The first compartment 116 of the upper and lower shells 106, 108 includes a rounded engagement surface 128 which supports and compresses an outer surface of the ferrule assembly 102 as explained below.
The ground shield assembly 110 includes U-shaped frame elements 130 that are dimensioned to be attached to and substantially surround the forward end 126 of the upper shell 106 and a forward end 132 of the lower shell 108. Each of the frame elements 130 includes grounding fingers or tabs 134 which extend inwardly into the second compartment 118 of the upper and lower shells 106,108 to contact the outer surfaces of a header shield 206 (described below in relation to
The cable braid 112 is substantially cylindrical as shown in
A retaining lip 170 extends outwardly from the respective inner surfaces 152 and 154 at a distance from the radial grooves 164 and 166 of the respective ferrule elements 142 and 144. The ferrule elements 142 and 144 are separately formed and fabricated from one another in a known die cast metal process. The ferrule elements 142, and 144 are essentially mirror images of one another, and are snap fit to one another over the end 156 of the cable conductors 114 as shown in
Once the ferrule elements 142, 144 are in place on the cable, the braid 112 may be drawn over the ferrule elements up to retaining rims 162, 158 and be clamped to the ferrule assembly in a straightforward manner with the retaining band 146. The retaining band 146 in an exemplary embodiment is a known clamp element having an adjustable stainless steel ring 180 and buckle 182 which compresses the end 156 of the cable braid 112 onto the ferrule elements 142 and 144. One such retaining band is a commercially available BAND-IT clamping system of Band-It-Idex, Inc. of Denver, Colo. The ring 180 is extended over cable braid 112 and the ferrule elements 142, 144 between the respective retaining lips 168, 170 and the rims 158, 162. Once located over the ferrule elements 142 and 144, the ring 180 is tightened over the ferrule elements 142, 144 and the buckle 182 latches the ring 180 in place to attach the cable braid 112 to the ferrule elements 142,144.
The resilient contact element 148 is toroid shaped and is dimensioned so that it may be received in the radial grooves 164, 166 of the ferrule elements 142 and 144. As shown in
The resilient contact element 148 in an exemplary embodiment is a canted-coil spring having inclined or canted coils that deflect independently when compressed. As such, the entire spring element responds wherever any portion of a coil is deflected by the upper and lower shells 106, 108, thereby permitting uniform loading at each contact point. Additionally, the canted coil spring presents a large number of contact points with the upper and lower shells 106, 108 (
When compressed, the resilient contact element 148 maintains secure mechanical and electrical engagement between the upper and lower shells 106 and 108 and the ferrule elements 142 and 144, while the retaining band 146 maintains secure mechanical and electrical engagement between the ferrule elements 142,144 and the cable braid 112. The ferrule elements 142, 144, and the resilient contact element 148 permit some flexibility in assembling the connector 100, particularly with regard to terminating the cable conductors to the connector 104 (
A header shield 206 substantially surrounds the backplane connector 202 and is attached to printed circuit board 204 with fasteners 208 as shown in
A connector interface panel 220 includes a number of cutouts or apertures 222 which are dimensioned to receive a front shroud 224 of the header shield 206 as shown in
The panel 220 may be mounted to, for example, a chassis (not shown) of a computer system and serve as an input/output port for communicating with circuit boards in the chassis via header assemblies 200. Once the header assembly 200 is mounted to the panel 220, the cable connector assembly 100 (
The cable connector assembly 300 includes an inner ferrule assembly 302, a cable connector 304, upper and lower shells 306 and 308 which receive the inner ferrule assembly 302 and the cable connector 304, and a ground shield assembly 310.
The ferrule assembly 302 is attached a conductive metallized braid 312 of a cable 314, and the ferrule assembly 302 is received within a first compartment 316 defined by the upper and lower shells 306, 308. The cable connector 304 is electrically connected to conductors in the cable, and the cable connector 304 is received in a second compartment 318 defined by the upper and lower shells 306, 308. The ferrule assembly 302 includes approximately a 90° bend in an illustrative embodiment, although the ferrule assembly may include a bend of greater or less than 90° in an alternative embodiment.
In an exemplary embodiment, the cable connector 304 is a known connector which is mechanically and electrically connected or terminated to conductors in the cable. As such, and in an exemplary embodiment, the cable connector 304 provides interconnection of high-speed, low-voltage, differential signals between the cable and a backplane connector, such as the connector 202 (
In an exemplary embodiment, each of the upper and lower shells 306, 308 are fabricated from a conductive material, such as die cast metal, and the shells 306, 308 form a protective enclosure about a portion of the ferrule assembly 302 and the cable connector 304 when the shells 306 and 308 are coupled to one another. The upper and lower shells 306, 308 are sized and dimensioned to securely receive and retain the ferrule assembly 302 and the connector 304, and the upper and lower shells 306, 308 are mechanically connected to one another with known fastener elements such as screws or rivets.
The connector assembly 300 further includes side insulating shells 320 and 322 which are fabricated from plastic, for example, and snap together over the upper and lower shells 306 and 308. The side insulating shells 320 and 322 are formed with connector flanges 324 which receive mounting fasteners 326, such as jack screws shown in
The upper shield 306 includes shield retaining projections 328 adjacent a forward end 330 thereof. The ground shield assembly 310 includes L-shaped frame elements 332 which are dimensioned to be attached to and substantially surround the forward end 330 of the upper shell 306 and a forward end 334 of the lower shell 308. Each of the frame elements 332 includes grounding fingers or tabs 334 which contact the outer surfaces of mating header shield (not shown in
The ferrule element 340 includes a locating projection 360 adjacent the rim 352 which cooperates with a complementary shaped notch 362 (
The ferrule assembly 302 and contact element 348 permits a straightforward and lower cost assembly than known cable connectors while avoiding potential damage to the components during assembly. Reliable electrical contact between the cable braid 312 and the ferrule assembly 302 is ensured, and manufacturing and assembly costs are saved.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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Number | Date | Country | |
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20060105632 A1 | May 2006 | US |