Patent Publication Number: US-2005130490-A1

Title: High speed cable assembly including finger grips

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to cable assemblies, and more specifically, the present invention relates to high speed cable assemblies with housings having finger grips.  
      2. Description of the Related Art  
      It is well known to attach electronic components, such as electrical connectors, integrated circuit components, capacitors, resistors, etc., to printed circuit boards (PCBs) and to connect PCBs to one another with high speed cable assemblies.  
      Conventional high speed cable assemblies  21  include two termination enclosures  22  and  23  connected by coaxial cables  24 , as shown in  FIG. 9 .  
      In conventional high speed cable assemblies  21 , it is difficult to un-mate or remove the high speed cable assemblies from PCBs (not shown) to which they are attached. Because of the amount of force which must be applied to un-mate a high speed cable assembly  21  from a PCB, the cable assembly can be damaged by a “camming” effect between the termination enclosures  22  and  23  and the PCB. Typically, the pins of the electrical connector  25  are bent and/or the termination enclosure  22  or  23  is broken by the “camming” effect. It is also known in conventional high speed cable assembly design to have the termination enclosures  22  and  23  contain electrical connectors  25  and  26  of the high speed cable assembly  21 . When un-mating a high speed cable assembly  21  from a PCB, it is possible to separate or break off the unsupported termination enclosure portions  28  and  30  of the termination enclosures  22  and  23  to expose the supported termination enclosure portions  27  and  29  of the termination enclosures  22  and  23  which are mounted on the PCB.  
      One known solution to prevent the camming effect from damaging the high speed cable assembly  21  is to expose the area around the PCB where the termination enclosure  22  or  23  mates with the PCB. By exposing this area on the PCB, it is possible to apply force directly in-line with the termination enclosure  22  or  23 . However, this solution can damage exposed leads on the PCB, requires finger contact with the glass fibers of the PCB, and reduces the amount of usable space on the surface of the PCB.  
      One known solution to prevent the termination enclosures  22  and  23  from separating is to ultrasonically weld the supported termination enclosure portion  27  or  29  to the unsupported termination enclosure portion  28  or  30 , respectively. However, this solution suffers from drawbacks in that it requires additional processing steps and requires the unsupported termination enclosure portion  28  or  30  to be broken off the supported termination enclosure portion  27  or  29  (or vice versa) if the coaxial cables  24  need reworking or repair.  
     SUMMARY OF THE INVENTION  
      In order to overcome the above-described problems, preferred embodiments of the present invention provide a cable assembly which prevents damage caused by the camming effect, prevents unwanted separation of a housing enclosing an electrical connector, and allows for reworking or repair of the coaxial cable without damaging the housing enclosing the electrical connector, while minimizing the assembly steps and the area occupied on a PCB upon which the housing is mounted.  
      According to a preferred embodiment of the present invention, a cable assembly includes first and second housings and at least one cable connecting the first and second housings. At least one of the first and second housings is provided with at least one finger grip. The at least one finger grip projects out from a surface of the at least one of the first and second housings to allow for finger gripping of the at least one of the first and second housings during un-mating of the cable assembly from a PCB upon which it is mounted.  
      The at least one cable is preferably a coaxial cable. The at least one cable preferably includes a plurality of cables, which are preferably coaxial cables.  
      In another preferred embodiment, at least two finger grips are provided on opposite surfaces of the at least one of the first and second housings. The at least two finger grips preferably include an integral protrusion extending from the surface of the at least one of the first and second housings. The at least two finger grips are arranged to be spaced from an upper surface and a lower surface of the at least one of the first and second housings. This position of the at least two finger grips allows for an operator to reliably and firmly grip the housings and remove the cable assembly from the PCB upon which it is mounted, without experiencing any of the disadvantages of the conventional devices described above.  
      According to another preferred embodiment of the present invention, the cable assembly further includes at least one housing which has a first housing portion and a second housing portion that are removably connected. Preferably, the first and second housing portions are removably connected by at least one fastening member, for example, a screw.  
      The first housing portion preferably includes a latch, and the second housing portion preferably includes an engaging recess which is arranged such that the latch of the first housing portion is a zero insertion force latch that fits into the engaging recess. The latch preferably includes at least one beveled surface.  
      According to another preferred embodiment of the present invention, the cable assembly further includes a board and at least one electrical connector disposed on the board. The board connects the at least one cable and the at least one electrical connector. The board and the at least one electrical connector are disposed inside of one of the first and the second housings.  
      The at least one electrical connector is preferably a mezzanine board-to-board connector or other suitable connector.  
      The at least one cable preferably includes a first set of coaxial cables connected to one side of the board and a second set of coaxial cables connected to another side of the board.  
      Another preferred embodiment of the present invention preferably includes a first housing portion and a second housing portion each having at least one cylinder portion and at least one post disposed thereon. The board is held in place by the at least one cylinder portion and by the at least one post located on the first or second housing portion.  
      Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments thereof with reference to the attached drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an exploded view of a preferred embodiment of the present invention;  
       FIG. 2  is a side plan view of a preferred embodiment of the present invention shown in  FIG. 1 ;  
       FIG. 3  is isometric view of a preferred embodiment of the present invention;  
       FIG. 4  is a top plan view of a preferred embodiment of the present invention shown in  FIG. 3 ;  
       FIG. 5  is a top plan view of the bottom housing portion according to a preferred embodiment of the present invention;  
       FIG. 6  is sectional view along line A-A in  FIG. 5  of the bottom housing portion according to a preferred embodiment of the present invention;  
       FIG. 7  is a bottom plan view of the top housing portion according to a preferred embodiment of the present invention;  
       FIG. 8  is a sectional view along line B-B in  FIG. 7  of the top housing portion according to a preferred embodiment of the present invention;  
       FIG. 9  is isometric view of a conventional high speed connector assembly. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      A high speed cable assembly  1  according to a preferred embodiment of the present invention is illustrated in  FIGS. 1 and 2 . The high speed cable assembly  1  preferably includes a first housing  2  and a second housing  3  connected by first coaxial cables  8   a  and second coaxial cables  8   b.    
      The first housing  2  includes a top housing portion  2   a  and bottom housing portion  2   b . The first housing  2  encloses a printed circuit board  7  which has electrical connector  6  connected to it. The electrical connector  6  may be a board-to-board mezzanine connector, edge card connector or other suitable electrical connector. The electrical connector  6  is mounted on the printed circuit board  7  using suitable known techniques.  
      The printed circuit board  7  preferably has top and bottom connecting pads (not shown) for connecting the first coaxial cables  8   a  and the second coaxial cables  8   b  to the top and bottom, respectively, of the printed circuit board  7 . Preferably, the coaxial cables  8   a  and  8   b  are soldered to the PCB.  
      Other arrangements for connecting the printed circuit board  7  to the coaxial cables  8   a ,  8   b  could be used. For example, only the first coaxial cable  8   a  could be used to either connect to the top or the bottom of the circuit board  7 . Another arrangement could include connecting both the first coaxial cable  8   a  and the second coaxial cable  8   b  to the either the top or the bottom the printed circuit board  7 . Also, the printed circuit board  7  could be used to route the signals transmitted through the coaxial cables  8   a  and  8   b  across each other.  
      The top housing portion  2   a  includes latches  10   a  and  10   b  for insertion into engaging recesses  11   a  and  11   b  of the bottom housing portion  2   b . The engaging recesses  11   a  and  11   b  are preferably constructed such that it requires zero insertion force for the latches  10   a  and  10   b  to be inserted into the engaging recesses  11   a  and  11   b . It is also possible to use only one latch or to use three or more latches instead of the two latches  10   a  and  10   b  shown in the Drawings.  
      The top housing portion  2   a  further includes holes  12   a  and  12   b  and the bottom housing portion  2   b  further includes holes  13   a  and  13   b . The first housing  2  is constructed by using fastening members  5   a  and  5   b , such as screws, to secure the top housing portion  2   a  to the bottom housing portion  2   b  using holes  12   a ,  13   a  and  12   b ,  13   b , respectively, such that the electrical connector  6  is exposed through the opening  14  of the top housing portion  2   a . Further, the screws  5   a  and  5   b  engage holes  12   a ,  13   a  and  12   b ,  13   b , respectively, such that the tops of screws  5   a  and  5   b  are below the plane defined by the top surface of the top housing portion  2   a . It would also be possible to connect the top housing portion  2   a  with the bottom housing portion  2   b  using any other releasable fastening members or material such as metal or plastic clips or snap grooves.  
      The bottom housing portion  2   b  preferably includes finger grips  4   a  and  4   b  located on opposing sides of the bottom housing portion  2   b . The finger grips  4   a  and  4   b  are preferably integral with the bottom housing portion  2   b . For example, if the bottom housing portion  2   b  is formed of molded plastic, the finger grips  4   a  and  4   b  are integrally molded with the bottom housing portion  2   b . The finger grips  4   a  and  4   b  are preferably located on the bottom housing portion  2   b  spaced a distance away from a bottom surface of the bottom housing portion  2   b  that is mounted on a printed circuit board (not shown) upon which the cable assembly  1  is mounted. This location allows an operator&#39;s fingers to securely engage the finger grips  4   a  and  4   b  from bottom and top surfaces of the finger grips  4   a  and  4   b  to allow for the operator to reliably engage and manipulate the finger grips  4   a  and  4   b . It is also preferred that the finger grips  4   a  and  4   b  are located at a distance away from a top surface of the bottom housing portion  2   b.    
      In addition, the finger grips  4   a  and  4   b  are preferably disposed on opposite side surfaces of the bottom housing portion  2   b , and in-line with the location of the connector  6 .  
      In an alternative arrangement, the finger grips  4   a  and  4   b  may be provided on the top housing portion  2   a . In this case, the finger grips  4   a  and  4   b  are preferably located at a distance spaced away from the top surface and the bottom surface of the top housing portion  2   a.    
      In addition, although a first finger grip  4   a  and a second finger grip  4   b  are shown in  FIG. 1 , for example, a single finger grip could be provided on any of the three side surfaces of either the top housing portion  2   a  or the bottom housing portion  2   b  where the cables  8   a  and  8   b  are not attached. In addition, more than two finger grips may be provided on any of the three side surfaces of either the top housing portion  2   a  or the bottom housing portion  2   b.    
      The second housing  3  is preferably constructed in a similar manner as the first housing  2  where the reference numbers used to indicate the features of the first housing  2  are used to reference similar features in the second housing  3 . The second housing  3  is preferably constructed by using fastening members such as screws  5   a  and  5   b  to secure the top housing portion  3   a  to the bottom housing portion  3   b.    
       FIGS. 5 and 6  illustrates the bottom housing portion  2   b  or  3   b  of either the first housing  2  or the second housing  3 , respectively. The bottom housing portion  2   b  or  3   b  preferably includes substantially cylindrical portions  16   a  and  16   b  which define holes  13   a  and  13   b , respectively. The bottom housing portion  2   b  or  3   b  also includes posts  15   a  and  15   b . The printed circuit board  7  is held in place during and after the construction and assembly of the first housing  2  or the second housing  3  by the cylinder portions  16   a  and  16   b  and posts  15   a  and  15   b.    
      The engaging recesses  11   a  and  11   b  are preferably substantially rectangular insets as shown in  FIG. 6 . However, other possible shapes other than substantially rectangular could be used for engaging insets defining the recesses  11   a ,  11   b.    
       FIGS. 7 and 8  illustrate the top housing portion  2   a  or  3   a  of the first housing  2  or the second housing  3 , respectively. The top housing portion  2   a  includes the latch  10   a  which has a first beveled edge  10   a   1  along the top surface  10   a   2  of the latch  10   a  and a second beveled edge  10   a   3  along the side surfaces  10   a   4  of the latch  10   a . The latch  10   b  has a similar structure including a first beveled edge  10   b   1  along the top surface  10   b   2  of the latch  10   b  and a second beveled edge  10   b   3  along the side surfaces  10   b   4  of the latch  10   b.    
       FIGS. 3 and 4  illustrate another preferred embodiment of the present invention.  FIGS. 3 and 4  illustrate a high speed cable assembly  1 ′ which preferably includes a first coaxial cable  8   a , a second coaxial cable  8   b , a third coaxial cable  8   c , and a fourth coaxial cable  8   d . The first coaxial cable  8   a  and second coaxial cable  8   b  connect first electrical connector portions  6   a  between the first housing  2  and second housing  3 . The third coaxial cable  8   c  and fourth coaxial cable  8   d  connect second electrical connector portions  6   b  between the first housing  2  and second housing  3 .  
      Other possible arrangements than the one shown in  FIGS. 3 and 4  could also be used. For example, more than two electrical connectors could be used with more than two pairs of coaxial cables. Also, more than one housing could be used at either or both ends of the cable assembly. For example, one end of the cable assembly could have multiple housings, each enclosing one or more electrical connectors, and the other end of the cable assembly could have one housing enclosing multiple electrical connectors.  
      As can be clearly understood from the detailed description of preferred embodiments of the present invention above, the cable assembly of preferred embodiments of the present invention achieves many significant advantages not previously attained by conventional devices and solves many problems not recognized or solved by conventional devices. Preferred embodiments of the present invention provide reliably gripping mechanism that allows a cable assembly to be quickly, easily and reliably removed from a PCB upon which it is mounted without any damage to the PCB or the cable assembly or connectors included therein. Thus, the cable assembly of preferred embodiments of the present invention prevents damage caused by the camming effect, prevents unwanted separation of a housing enclosing an electrical connector, and allows for reworking or repair of the coaxial cable without damaging the housing enclosing the electrical connector, while minimizing the assembly steps and the area occupied on a PCB upon which the housing is mounted.  
      While preferred embodiments of the invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing the scope and spirit of the invention. The scope of the invention, therefore, is to be determined solely by the following claims.