Patent Document

TECHNICAL FIELD OF THE INVENTION 
     The present invention relates generally to systems and methods for connecting cables to connector carriers, and more particularly to a system and method for securing cables to a carrier that relieves strain on the cables and prevents inadvertent damage or disconnection of the cables from the carrier. 
     BACKGROUND OF THE INVENTION 
     In recent years, the increase in the usage of electrical equipment such as audio visual equipment, electronics, power supplies, and computers has increased the number of cables and connectors used to interconnect such equipment. Often these cables are large and bulky, imparting strain on the cables and the connector. Alternatively, the cables and connectors may be small, delicate, and easily susceptible to damage from small forces. In either case, the connectors and cables can be fairly expensive. Damage to either may result in monetary losses, disruption to electronic systems, and electrical hazards. 
     Various methods and systems have been proposed to securely fasten cables to an interface. One method is disclosed in U.S. Pat. No. 4,842,550 issued Jun. 27, 1989, to Fry, et al. Fry, et al. discloses a molded housing with a cover in a base. A tie strap connected to the base ties around the cables and is used as a strain relief. 
     Another method to securely fasten cables to an interface is disclosed in U.S. Pat. No. 4,842,549, issued Jun. 27, 1989, to Asick, et al. Asick, et al., discloses a two-piece housing, dual-diameter strain relief, and a dual-diameter cylindrical channel. Forces on the cables are transferred to the housing through a cable tie that wraps once around the cable and rests in a recess in the bottom housing piece. The cylindrical channel in which the cable resides has a smaller diameter portion and a larger diameter portion. Smaller diameter cables are strain relieved in the smaller portion of the channel, whereas larger diameter cables on strain relieved in the larger portion of the channel. 
     A third system for securely fastening cables to a connector is disclosed in U.S. Pat. No. 4,640,984, issued Feb. 3, 1987, to J. W. Kalbfeld. Kalbfeld discloses a strain relief made of resiliently deformable material consisting of two portions coupled by a strap, the portions surrounding the cable in such a manner to force the cables into a U-shaped bend. The friction of the bend prevents the movement of the cables relative to the strain relief. At least one of the two portions has a means to attach to a two-part connector with a lower and upper body. The lower body can be securely coupled to each other through the use of connectors such as screws. 
     Each of these prior art patents have strain relief mechanisms that physically contact the cables that are being coupled to the connector. These configurations may subject the cables to physical deformation and strain over time. Physical damage may result in an electrical failure. Also, each of these prior art patents discloses fairly complex molded housings that surround the interface connector. These housings may not be readily adapted to varying sizes of cables and connectors. 
     Moreover, a need exists for an apparatus that will protect the interface between cables and a connector that is readily adaptable to various interface and cable sizes. Also, it would be advantageous if the strain relief for the interface connector does not present any physical strain on the cable itself. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system and method for securing cables to a connector carrier that substantially eliminates or reduces disadvantages or problems associated with previously developed systems and methods used for securing cables to a connector carrier. 
     More specifically, the present invention provides an apparatus used to secure a carrier to one or more cables coupled to the carrier. The strain relief system and method for securing the cable(s) to the carrier includes a clamping fixture surrounding the interface between the carrier and the cable(s) and a tether comprising a first and second end. The first end of the tether is coupled to the clamping fixture while the second end of the tether is coupled to the source of the cable(s). 
     The present invention provides an important technical advantage by implementing a simple design easily adaptable to various interface connection sizes. The dual-plated clamping fixture is easily modified to interface with various types of connectors. 
     The present invention provides another technical advantage by implementing a tether that reduces strain on the cables connected to the interface. The tether, however, does not contact the cable(s) and therefore does not impart physical damage upon the cable(s). Any physical strain placed on the cable(s) is transferred from the termination of the cable(s) to the dual-plated clamping fixture. Also, the length of the tether is shorter than the length of the cable(s). Thus, this prevents the source of the cable(s) from being pulled from the termination of the cable(s) any distance farther than the length of the tether. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete understanding of the present invention and the advantages thereof may be acquired by referring to the following description, taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein: 
     FIG. 1 is an exploded perspective of the assembly of an embodiment of the present invention; 
     FIG. 2 is a side view of the coupling of the carrier by the clamping fixture; 
     FIGS. 3A and 3B illustrate a top view and front view of the clamping fixture with the tether; 
     FIGS. 4A and 4B illustrate the side view and bottom view of the top plate of the clamping fixture and 
     FIGS. 5A and 5B illustrate the top view and side view of an additional embodiment of the base plate of the clamping fixture. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Preferred embodiments of the present invention are illustrated in the figures, like numerals being used to refer to like and corresponding parts of various drawings. 
     The present invention provides a system for securing a connector to one or more cables. The system includes a clamping fixture that surrounds and reinforces the carrier and the cables. The system also includes a tether to reduce the strain on the cables as well as prevent inadvertent disconnection of the cables from the connector. 
     The present invention provides a system and method for securing cables to a carrier that relieves strain on the cables and prevents inadvertent damage or disconnection of the cables from the carrier. 
     The method of the present invention provides for securing an interface connection. The interface connection may consist of one or more cables coupled to a carrier. A clamping fixture secures the cables to the carrier and prevents any relative motion between the cables. The clamping fixture may have a variety of internal surfaces which interlock with surfaces of the connector to prevent relative motion. Stress is relieved within the cables by coupling a stess relieving tether to the clamping fixture. This tether serves to accept stresses which would other wise be imparted on the cable by providing that the there is an excess in the length of the cables as compared to the length of the tether. Additionally, the stress on the cable and its terminal connections by which it is coupled to the carrier may be reduced by having the terminal connections abut the clamping fixture. This will further restrict the movement of the cables relative to the carrier. 
     FIG. 1 is an exploded perspective of one embodiment of the present invention. This embodiment consists of a top plate  10  placed in parallel with a base plate  12  to form a clamping fixture that surrounds the carrier  14  which connects to one or more cables  16 . The cables  16  are coupled to the carrier  14  at the cable terminations  18 . A group of screws  20  may pass through holes  22  in the top plate  10  and subsequently thread into threaded holes  24  in the base plate  12  to securely fasten the top plate  10  to the base plate  12 . Two protruding flat surfaces  26  on the bottom face of the top plate  10  fit flatly against two corresponding flat protruding surfaces  28  on the top face of the base plate  12 . Two flat recessed surface  30 ,  32  reside between the two flat protruding surfaces  26 ,  28  on both the bottom of the top plate  10  and the top of the base plate  10  respectively. Due to the perspective of FIG. 1, the first flat recessed surface  30  on the bottom surface of the top plate  12  can not be seen. These two first recessed surfaces  30 , 32  form a cavity for the one or more cables  16  attached to the carrier  14 . The cavity prevents movement of the connector in the z-direction. Both the two first recessed surfaces  30 , 32  are further recessed to form two second recessed surfaces  34 , 36 . The second recessed surface  34  of the top plate cannot be seen in FIG. 1 but is shown in FIG.  4 A. When the clamping fixture is secured properly, the second recessed surface  34  on the bottom face of the top plate  10  and the second recessed surface  36  on the top face of the bottom plate  12  fit tightly against the top and bottom face of the carrier  14  respectively. Edges  38  between the first recessed surfaces  30 , 32  and the second recessed surfaces  34 , 36  on both the top plate  10  and the base plate  12  abut the top and bottom of the cable terminations  18 . The edge  38  on the bottom face of the top plate  10  can not be seen in FIG.  1 . The second recessed surface  36  on the base plate  12  has a rectangular ridge  40  that engages a rectangular groove  42  in the carrier  14 . Due to the perspective of FIG. 1 the rectangular groove  42  cannot be seen on the bottom face of the carrier  14 . A tether  44  can be attached between the top plate  10  and the carrier  14  by means of a screw  20 . Attaching the tether  44  is illustrated more clearly in FIG.  3 B. 
     FIG. 2 represents a side view of the coupling of the clamping fixture comprising the top plate  10  and bottom plate  12  and the carrier  14 . From the side view it can be seen how the ridge  40  on the top face of the base plate  12  prevents movement of the carrier  14  by engaging the groove  42  on the bottom face of the carrier  14 . It can also be seen from FIG. 2 that cable terminations  18  abut against both the edge  38  between the two recessed surfaces  30 , 34  on the bottom face of the top plate  10  and the edge  38  between the two recessed surfaces  32 , 36  on the top face of the base plate  12 . This abutment prevents movement of the cable terminations  18  relative to the clamping fixture. 
     FIGS. 3A and 3B illustrate the top view and front view of the clamping fixture and the tether  44 . The carrier  14  and the one or more cables  16  have been omitted for simplicity. It can be seen in FIG. 3B that the tether  44  surrounds a screw  20  that couples the top plate  10  and base plate  12  securely together. It can also be seen in FIG. 3B that the raised edges  26 , 28  on the bottom corners of both top plate  10  and base plate  12  abut together to leave a cavity  46  between the top plate  10  and the base plate  12  of the clamping fixture. The cavity  46  allows room for the one or more cables  16  that connect to the carrier  14 . The cavity  46  does not impart any physical stress on the cable  16 . 
     FIGS. 4A and 4B provide additional views of the top plate  10 . FIG. 4A provides the side view of the top plate  10  including the flat protruding surface  26 , the first recessed surface  30 , the second recessed surface  34 , and the edge  38  between the first recessed surface  30  and the second recessed surface  34 . FIG. 4B provides a view of the bottom surface of the top plate  12  including the flat protruding surfaces  26 , the first recessed surface  30 , the second recessed surface  34 , the edge  38  between the first recessed surface  30  and the second recessed surface  34 , and the holes  22  for the screws  20  to fasten the top plate  10  to the base plate  12 . 
     FIGS. 5A and 5B provide views of an additional embodiment of the base plate  12 . FIG. 5A provides the side view of the base plate  12  including the flat protruding surface  28 , the first recessed surface  32 , the second recessed surface  36 , the edge  38  between the first recessed surface  32  and the second recessed surface  36 , and the rectangular ridge  40  that engages the carrier  14 . FIG. 5B provides a view of the top surface of the base plate  12 , including the flat protruding surface  28 , the first recessed surface  32 , the second recessed surface  36 , the edge  38  between the first recessed surface  32  and the second recessed surface  36 , the rectangular ridge  40  that engages the carrier  14 , and the threaded screw holes  24  for the screws  20  to fasten the top plate  10  to the base plate  12 . 
     In addition, this embodiment of the base plate  12  may include a notch  48  that can transverse the second recessed surface  36  of the base plate  12  in the y-direction and may partially transverse the ridge  40  of the base plate  12 . This notch conforms to a corresponding structure on the carrier and serves to properly position the base plate  12  and corresponding top plate  10  relative to the carrier as well as prevent movement of the base plate in the y-direction relative to the carrier. 
     The present invention provides an important advantage in that the dual-plated structure consisting of a top plate  10  and a base plate  12  reinforces the connection between the cables  16  and the carrier  14 . The dual-plated clamping fixture protects the interface between the carrier  14  and the cables  16  from external forces that may cause inadvertent disconnection of the cables  16  from the carrier  14 . 
     Another technical advantage of the present invention is that the base plate  12  consists of a ridge  40  that mates with a corresponding groove  42  in the carrier  14 . This ridge prevents movement of the carrier  14  in the y-direction with reference to the clamping fixture. 
     The present invention provides still another technical advantage in that a groove  48  on the base plate  12  further aids in placement of the clamping fixture with reference to the carrier  14 . The groove also prohibits movement of the carrier  14  in the y-director relative to the clamping fixture. 
     Another technical advantage of the present invention is that the edge  38  between the first recessed surfaces  30 ,  32  and the second recessed surfaces  34 ,  36  abut the terminations  18  of the cables  16 . This prevents the movement of the cables  16  away from the carrier  14 . Also any forces felt on the cables  16  are transferred to the clamping fixture through the terminations. 
     The present invention provides yet another technical invention in that the tether  44  provides a strain relief for the cables  16 . The tether  44  prevents the source of the cables from being pulled away from the terminations  18  of the cables any distance further than the length of the cables  16 . Since the tether  44  is shorter than the cables  16 , this eliminates or reduces strain on the cables  16  and transfers it to the clamping fixture. 
     Although the present invention has been described in detail herein with reference to the illustrative embodiments, it should be understood that the description is by way of example only and is not to be construed in a limiting sense. It is to be further understood, therefore, that numerous changes in the details of the embodiments of this invention and additional embodiments of this invention will be apparent to, and may be made by, persons of ordinary skill in the art having reference to this description. It is contemplated that all such changes and additional embodiments are within the spirit and true scope of this invention as claimed below.

Technology Category: h