Patent Publication Number: US-6210216-B1

Title: Two port USB cable assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a USB (Universal Serial Bus) cable assembly, and in particular to a two port USB cable assembly having a grounding device for facilitating ESD (Electro-Static Discharge) and EMI protection of the USB ports. 
     2. The Prior Art 
     A USB cable comprises a cable with a USB connector mounted to an end thereof. For a USB cable mounted to a panel of a computer enclosure, an electrical engagement between a shielding shell of the USB connector of the cable and the panel is required to provide ESD and EMI protection. A variety of grounding devices is implemented in USB cables available in the market. The conventional grounding devices of USB cables either are complicated in structure or require a laborious assembly process. 
     On the other hand, a two port USB cable having a cable end connection device comprising two USB connectors is not common in the market. Such a two port USB cable requires a grounding device having a simple structure and being easy to assembly for facilitating the manufacture thereof and reducing costs. 
     It is thus desired to provide a two port USB cable having a grounding device having a simple structure and easy to assemble. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a USB cable comprising a grounding device having a simple structure for being easy to manufacture and assembly and reducing costs. 
     Another object of the present invention is to provide a USB cable comprising a cable end connection device comprising two USB connectors. 
     A further object of the present invention is to provide an electrical connector having a grounding device having a simple structure for being easy to manufacture and assembly and reducing costs. 
     To achieve the above objects, a USB cable assembly in accordance with the present invention comprises a cable having an end to which a connection device is attached. The connection device comprises an insulative casing in which two USB connectors are fixed and electrically connected to the cable. Two bores are defined in a front wall of the casing for rotatably retaining two bolts. A conductive plate associated with each bolt is fixed in the casing having a first section defining a hole through which the bolt extends and a second section resiliently engaging with a conductive shield of the corresponding USB connector. The first section has step-like edges fixedly received in L-shaped slits defined in the front wall with the first section overlapping an outside surface of the front wall whereby when the connection device is secured to an external grounding panel by the bolts, the conductive plate engages with the grounding panel forming an electrical connection between the shield of the corresponding USB connector and the grounding panel. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the accompanying drawings, in which: 
     FIG. 1 is a perspective view of a USB cable assembly constructed in accordance with the present invention; 
     FIG. 2 is an exploded view of the USB cable assembly; 
     FIG. 3 is a plan view of the USB cable assembly with an upper cover member of a cable end connection device thereof removed to show inside details; 
     FIG. 4 is a perspective view of a fastener incorporated in the cable end connection device of the present invention for securing the cable end connection device to a panel; 
     FIG. 5 is a perspective view of a grounding device of the USB cable assembly; and 
     FIG. 6 is a perspective view showing the cable assembly mounted to the panel. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings and in particular to FIGS. 1-3, a cable assembly constructed in accordance with the present invention, generally designated by reference numeral  10 , comprises an elongate cable  12  and at least one cable end connection assembly  14  mounted to and electrically connected to an end of the cable  12 . 
     The cable end connection device  14 , which will be referred to as connection device hereinafter for simplicity, comprises a casing  16  made of insulative material comprising an upper casing member  18  and a lower casing member  20  fixed to each other for defining an interior space therebetween to accommodate two USB connectors  22 . The USB connectors  22  are electrically connected to the cable  12  and partially protrude beyond a front wall  24  of the casing  16 . The upper and lower casing members  18 ,  20  are fixed to each other by any known means, such as interferential fitting. 
     Also referring to FIGS. 4 and 6, two fasteners  26  are mounted in the casing  16  on opposite sides of the two USB connectors  22  for attaching the connection device  14  to a panel  28 . Each fastener  26  comprises a threaded rod  30  having two expanded ends  32 ,  34 . A nut  36  threadingly engages the threaded rod  30  of the fastener  26  whereby when the fastener  26  is rotated, the nut  36  is moved axially with respect thereto. A slot  38  is defined in a first expanded end  32  of the fastener  26  for engaging with a tool, such as a screwdriver, to tighten the fastener  26 . In the embodiment illustrated, the slot  38  is cruciform for engaging a Philip type screwdriver, but it may be a straight one for engaging a flat screwdriver. 
     The threaded rod  30  is rotatably received in a bore  40  defined through the front wall  24  of the casing  16  with the first and second ends  32 ,  34  respectively located outside and inside the casing  16 . A cavity  42  is defined in the front wall  24  for fixedly receiving the nut  36  whereby when the fastener  26  is driven by a screwdriver, the first end  32  is moved toward/away from the panel  28  for securing/releasing the connection device  14  to/from the panel  28 . Preferably, the nut  36  is polygonal, such as hexagonal, and the recess  42  has a corresponding shape for fixedly accommodating the nut  36  therein. 
     Also referring to FIG. 5, each fastener  26  comprises a grounding device  44  engaging with both the fastener  26  and a conductive shield  46  of the USB connector  22  adjacent thereto. The grounding device  44  comprises a substantially L-shaped conductive plate  4  having a first section  48  and a second section  50  substantially normal to each other. The first section  48  defines a hole  52  through which the threaded rod  30  of the corresponding fastener  26  extends. The first section  48  forms two stepliked edges  54 ,  56  with the second section  50  extending from the second edge  56 . Two L-shaped slits  58  are defined in the front wall  24  of the casing  16  on opposite sides of each bore  40  for fixedly receiving the first and second step-like edges  54 ,  56  of the first section  48  thereby fixing the grounding device  44  in position with the first section  48  overlapping an outside surface of the front wall  24  and supported thereby and the second section  44  resiliently engaging the shield  46  of the corresponding USB connector  22 . 
     Openings  60  are defined in the panel  28  for receiving and engaging with the fasteners  26 . Each opening  60  comprises a circular hole (not labeled) having a diameter large enough to allow the first end  32  of the fastener  26  to extend therethrough and a reduced slot (not labeled) having a width smaller than the diameter of the circular hole but is sufficient to accommodating the threaded rod  30  of the fastener  26  therein with two banks thereof engaging with the first end  32  of the fastener  26 . By tightening the fastener  26 , the connection device  14  is secured to the panel  28  forming a surface contact the panel  28  and the front wall  24  of the casing  16 . The first section  48  of the grounding device  44  electrically engages the panel  28  establishing an electrical connection between the panel  28  and the corresponding USB connector  22 . Two slots  62  each having the similar vertical dimension to the opening  60 , are defined in the panel  28  through which the USB connectors  22  first approach to the upper portions thereof and successively downwardly move, and thus project restrictedly in the lateral direction and beyond the panel  28  for engagement with mating connectors of other devices (not shown). The way of how to assemble the cable assembly  10  to the panel  28  through the fastener  26  of the cable assembly  10  and the opening  60  of the panel  28 , can be mainly referred in the copending application 09/449,108 filed Nov. 24, 1999 with the title of “PANEL MOUNT ELECTRICAL CONNECTOR ASSEMBLY” and the same assignee with the invention. 
     Although the present invention has been described with reference to the preferred embodiment, it is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.