Abstract:
A stabilizer for holding a circuit card in an electrical port is provided. The stabilizer includes a frame. A lever having a pivotal mounting with respect to the frame is included. The lever has a portion for making contact with an edge of the circuit card to urge the circuit card towards the electrical port. The stabilizer has a fulcrum to set an angle of inclination of the lever with respect to the frame. The fulcrum contacts the lever between the lever&#39;s pivotal mounting and the circuit card.

Description:
FIELD OF THE INVENTION 
     This invention relates to an apparatus and method of utilization thereof of stabilizers mounting of circuit boards in an electrical port. More particularly, the present invention relates to a stabilizer for holding a circuit board or expansion card in an electrical port or expansion card socket of a personal computer. 
     BACKGROUND OF THE INVENTION 
     Personal computers such as the IBM family of personal computers and the so-called IBM clones or compatibles are produced with an “open architecture” design for allowing additional functions to be later added to the computer. As a result, a number of manufacturers produce various printed circuit boards or (sometimes called “I/O cards” or “expansion cards”) which are mounted in the computer for later expanding its available functions. For instance, expansion cards can be installed in the computer to provide a hard disk drive controller, a color/graphics monitor, networking, memory expansion, printer ports, accelerator functions, modems, and the like. 
     In order to facilitate connection of expansion cards to the computer circuitry, the computer has a number of expansion slots on the rear panel of the computer chassis. The expansion slots have separate removable cover plates for radiation shielding and for serving as dust covers for the expansion slots. The expansion card has a long, narrow edge connector which projects from the bottom edge of the card and is plugged into an electrical port commonly referred to as an expansion card socket. The edge connection has a number of parallel metal plated male contacts which make contact with corresponding spring-loaded female contacts in the expansion card socket. The expansion socket may be ISA (Industry Standard Architecture) or the newer PCI (Preferred Component Interconnect) type socket. PCI sockets are usually physically longer than the older ISA sockets. Therefore, PCI circuit cards tend to be longer than ISA circuit cards. The cover plate originally used for the expansion slot is usually thrown away when the expansion card is added. The old cover plate is replaced by a fill-length mounting bracket fastened to the rear edge of the expansion card. This mounting bracket together with the card&#39;s connection to the socket at the base of the computer chassis provide a dual means of support at the bottom and rear edge of the card for stabilizing the expansion card (holding it in a fixed upright position) inside the unit. The mounting bracket also aids in resisting the tendency of the female contacts of the card socket pushing the male contacts of the expansion card out of the card socket. 
     The mounting bracket is a specially fabricated metal piece having a flat face to cover the expansion slot (to serve as the radiation shield and dust cover in place of the removed cover plate). The bracket also has a tab at its top for fastening to the top inside edge of the computer chassis by the screw that held the expansion slot&#39;s original cover plate in place. The manufacturer of the expansion card typically fastens the special mounting bracket to the expansion card during assembly of the expansion card. The bracket is rigidly fastened to the edge of the card by riveting or by fasteners such as screws. 
     The above-noted expansion card mounting system typically works fine in an office or home environment. In an office or home environment, the computer is generally isolated from vibration or shock. In industrial, transportation, and military applications, the computer can often be subject to shock or vibration which will cause the expansion card to dislodge or to vibrate and cause the male and female contacts to intermittently or permanently lose engagement. It would be highly desirable to provide a stabilizer which would prevent inadvertent dislodgement between the male and female contacts due to adverse environmental conditions. 
     SUMMARY OF THE INVENTION 
     To meet the above-noted desires, the revelation of the present invention is brought forth. In its preferred environment, the revelation of the present invention brings forth the freedom of stabilizing an expansion card in an expansion socket which during shock or vibration of the computer chassis. A preferred embodiment of the present invention provides a stabilizer for holding a circuit card in an electrical port includes a frame. A lever having a pivotal mounting with respect to the frame is provided. The lever has a portion for making contact with an edge of the circuit card to urge it towards the electrical port. The stabilizer has a fulcrum to set an angle of inclination of the lever with respect to the frame. The fulcrum contacts the lever between the lever&#39;s pivotal mounting and the circuit card. 
     The above noted and other features of the present invention will become apparent to those skilled in the art from a review of the following description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of a preferred embodiment stabilizer for holding a circuit board of the present invention. 
     FIG. 2 is a side elevational view of the stabilizer shown in FIG.  1 . 
     FIG. 3 is a front elevational view of the stabilizer shown in FIG.  1 . 
     FIG. 4 is a perspective environmental view of the stabilizer of the present invention installed in a computer chassis. 
     FIG. 5 is a view taken along line  5 — 5  of FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to FIGS. 1-5 the present inventive stabilizer  7  for holding a circuit card provides a frame  10 . The frame  10  has a flat portion  12  having a first side  14  which is accessible to a technician after removal of a computer chassis top panel (not shown). The frame  10  has several apertures  16  allowing it to be secured within a chassis  70  (FIG. 4) of the computer chassis. Joining to the frame flat portion  12  are two generally perpendicular side walls  18 . The side walls  18  have connected to them outwardly extending feet  20 . The feet  20  provide extra additional stiffening to the frame  10 . 
     The frame flat portion  12  has a series of generally parallel transverse slots  22 . The transverse slots  22  of the frame intersect generally transversely widened slot portions  24  at an upper end of each side wall. The frame  10  is typically fabricated from a sheet metal with the slots  22  being formed before the side walls  18  are bent with respect to the flat portion  12 . 
     Pivotally mounted with respect to the frame are a series of finger levers  26 . As shown, there is one lever  26  for each slot  22 . (Note: the uppermost lever  26  shown in FIG. 1 has been removed from FIG. 2 for clarity.) In the embodiment shown, each lever  26  is used to stabilize a single circuit card  28 . The lever  26  has a bend  27 . However, in an embodiment not shown, the lever is dimensioned to stabilize a plurality of circuit cards. The lever has at one end a tongue  30 . The tongue  30  is bent with respect to the remainder of the lever and is inserted in one of the transversely widened slots  24 . After insertion of the tongue  30 , the lever  26  is pivotally mounted with respect to the frame  10 . The tongue  30  is bent at 85° with respect to a lever upper end  31 . The 5° overbend from perpendicular of the tongue  30  from lever upper end  31  aids in retention of the tongue  30  in the transversely widened slot  24  when the lever upper end  31  is closely angled with the frame side wall  28 . The lever  26  is pivotal in a plane generally parallel and coplanar with the plane of the circuit card  28 . The lever has a tip or a contact portion  32  for contact with the circuit card  28  along a top edge  34  of the circuit card  28 . As shown, contact portion  32  has a convex curvature with respect to the circuit card  28 . In the embodiment shown, the contact portion  32  is at an extreme end of the lever  26 . The contacting portion  32  has a longitudinal groove or opening  36  which is typically aligned with the edge  34  of the circuit card to capture the circuit card  28 . The contact portion  32  is also coated with an electrically insulating polymeric (preferably elastomeric) substance to electrically insulate the lever  26  from the card  28 . Additionally, a web of the electric insulation in the longitudinal groove  36  of the lever contact portion  32  works to cushion and laterally stabilize the card  28  along its top edge  34 . 
     Each lever  26  has associated therewith a support or fulcrum  40 . The fulcrum is fabricated from sheet metal. The fulcrum has a first part  42  which is generally adjacent to the flat portion  12  of the frame opposite the frame first side  14 . The first part of the fulcrum  42  is connected to the frame by a threaded fastener  44 . The fastener  44  has a shank  46  which penetrates the slot  22 . The fastener  44  has a head  48  on an opposite first side  14  of the frame flat portion which compresses a spring washer  50 . The fastener threadedly connects with a flat washer  52  which juxtaposes the first part of the fulcrum  42  between the washer  52  and the frame flat portion  12 . The first part of the fulcrum  42  also has an upturned stud  56  which allows a technician to move the fulcrum  40  along the slot for infinite adjustment of position. The stud  56  has a transverse dimension which is close to that of the width of the slot  22  and also aids in the prevention of the fulcrum rotating about the fastener  44 . When a desired adjusted position is obtained, a screw driver is utilized to torque the head  48  of the fastener. 
     The fulcrum also has a second part  60  (FIGS. 2,  5 ) which is an example shown in integrally joined to the first part  42 . The second part  60  has an inclination of approximately 45° with the flat portion  12  of the frame and is inclined in a direction towards the pivotal connection of the lever with the frame. The second part  60  has a closed slot  62  which the lever  26  extends through. The slot  62  of the fulcrum second part allows the fulcrum  40  to capture the lever  26  when no circuit card is inserted underneath. Upon insertion of a circuit card, the fulcrum  40 , frame flat portion  12  and lever upper end  31  will form a triangular support structure to stabilize an underlying circuit card  28  in its electrical port (expansion socket  72 ). 
     In operation, the frame  10  with several lever and fulcrum combinations is installed into a chassis  70  of the computer. The frame  10  is accessible when top side panel (not shown is removed). When a new expansion card  28  is to be added to the computer and a prior expansion slot cover plate  78  along the rear panel of the computer is removed. A determination is made, based upon the size of and shape of the circuit card  28 , and the exact location of the frame  10 , on which end of the slot  22  to pivotally mount the lever  26  into transversely widened slot portion  24 . The location of the expansion socket  72  will also effect which end of the frame  10  to suspend the lever  26  from. The fulcrum  40  is also installed in the approximate slot  22  with the fastener  44  untorqued. The expansion card  28  is then inserted through the expansion slot. The male edge contacts of the lower end  74  of the expansion card are inserted into the female spring loaded contacts of the expansion card socket  72 . The lever  26  is placed over the installed expansion card  28  and the fulcrum  40  is adjustably positioned within the slot  22  to force the lever to contact a top edge  34  of the expansion card  8  along the elongated slot of the lever. After the circuit card  28  is secured, the fulcrum  40  is then fixably located in position along the slot  22  by a torquing the fastener  44 . 
     While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it is well understood by those skilled in the art that various changes and modifications can be made in the invention without departing from the spirit and scope thereof.