Abstract:
The present invention proposes to use additional support tabs for the stabilization of the PCI-express add-in cards, in particular, PCI-express add-in cards having a connector the size of one, four or eight links.

Description:
FIELD OF THE INVENTION 
   The present invention relates to the field of electrical connectors, and, more specifically, to add-in cards that are based on the PCI-express standard. 
   BACKGROUND OF THE INVENTION 
   The new interface PCI-express [1] is becoming more and more popular. For testing and debugging the PCI-express card different types of the test equipment are used, such as the PCI-express extender. In case the PCI-express card is installed on the PCI-express extender there is no possibility to fix this card in place by means of a standard bracket. It is important that the PCI-express connector is short (in cases of one, four or eight links) and has no special holding fixture. Therefore, the problem of stabilizing the PCI-express card becomes important in this case. 
   In  FIGS. 1   a  and  1   b  PCI-express add-in card  10  having PCI-express male connector  11  (plug) is represented. On main board  20  a female PCI-express connector  21  (socket) is located. In  FIG. 1   b  it is shown that PCI-express add-in card  10  is inserted into PCI-express female connector  21 . The length of the PCI-express card is significantly longer than the length of PCI-express connector  11  for connector types X1 (one link), X4(four links), and X8(eight links). It can create a danger of PCI-express card inclination in socket  21  and can break the connection quality. 
   The PCI-express add-in cards of type X16 (16 links) are equipped with a special feature to prevent said inclination. This feature ( 31 ) is “hockey stick”-shaped and is located on the bottom edge of PCI-express add-in card  10  ( FIG. 2 ). PCI-express male connector  11  is also located on the bottom edge of the card. The specification [1] and several patents [2-5], for example, define special retention mechanisms that are mounted on main board  20  on which the socket for the PCI-express card is located (said mechanisms aren&#39;t shown). This “hockey stick” feature  31  exists only in PCI-express cards X16 (16 links). 
   Various clips for fastening add-in cards are known, such as described in example [6]. The clip [6] is shaped like an “hourglass” in cross-section and is made of a uniform piece. 
   The present invention allows to stabilize the PCI-express add-in card position without complex features in cases when the bracket and other mechanisms are not used. It can be useful at work with various extender boards and motherboards using said PCI-express socket. 
   SUMMARY 
   The present invention is intended for the stabilization of the PCI-express add-in card [1]. Based on the PCI-express specification [1] all PCI-express add-in cards include a keep-out zone around the hole for special bracket fastening, a feature (short tab) meant to prevent the PCI-express card from being plugged into a normal PCI connector, and a PCI-express male connector (plug) located on the bottom edge of the card. The PCI-express male connector (plug) is used for connection with the PCI-express female connector (socket) located, for example, on the PCI-express extender. Said socket is mounted on the end edge (lateral surface) of said extender board (being on one plane with the said extender board). 
   The first aspect of the present invention consists in that said main board (for example, the PCI-express extender card) comprises one or two additional support tabs located on the same end edge (lateral surface) on which said socket for inserting PCI-express add-in card is located. Said support tabs are directed towards said PCI-express add-in card when said PCI-express add-in card is inserted into said socket. 
   The second aspect consists in that when there are two support tabs both these tabs are located around said socket from two opposite sides. The first support tab is located at the end edge between said socket and the main board end edge that is opposite to the bracket edge, when said PCI-express add-in card is inserted into said socket. The second support tab is located at the end edge of the main board between said socket and the bracket edge, when said PCI-express add-in card is inserted into said socket. More precisely, it is located opposite to the “short” tab of the PCI-express add-in card [1]. 
   The third aspect consists in that the height of said first support tab is equal to the distance between, for example, the edge of said extender board and bottom edge of the said PCI-express add-in card when said PCI-express add-in card is inserted into said socket. And in this case the upper edge of said first support tab touches to the bottom edge of the said PCI-express add-in card. 
   The fourth aspect consists in that said second support tab touches to said “short” tab when said add-in card is inserted into said PCI-express socket. 
   The fifth aspect consists in that position and geometric form of the first support tab can be various and this first support tab should probably be further from said PCI-express socket for the best stabilization of said PCI-express add-in card. 
   The sixth aspect consists in that the support tabs are part of the extender board and are made as one piece (the same printed circuit board) with the extender card (outline of each support tabs are included in extender board outline). 
   All those aspects are valid also if said PCI-express female socket is located on the plane surface of the main board (like computer motherboard). Only in this case said support tabs are made separately and are mounted on the motherboard surface. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1 . illustrates a computer system including PCI-express add-in card main board (prior art). 
       FIG. 1   a  illustrates a PCI-express add-in card and a female socket mounted on main board separately. 
       FIG. 1   b  illustrates a PCI-express add-in card in case this card is inserted into a female socket mounted on main board. 
       FIG. 2 . illustrates a PCI-express add-in card with X16 connector (16 links). 
       FIG. 3 . illustrates two stabilizing support tabs located at the end edge of the main board (extender card) according to present invention. 
       FIG. 4 . illustrates the improved computer system for PCI-express add-in cards (two cases of mutual positions of the PCI-express add-in card and the main board in cross-section view). 
       FIG. 4   a  illustrates the case when the said add-in card and the main board are located against each other separately. 
       FIG. 4   b  illustrates the case when said add-in card is inserted into a female socket located on said main board. 
       FIG. 5  illustrates the location of the PCI-express connectors (X1 and X16) on the computer motherboard according to the PCI-express standard [1] (prior art). 
       FIG. 6  illustrates the improved computer system for the PCI-express add-in card, including the PCI-express add-in card, main board (motherboard) and two additional stabilizing tabs located on the motherboard in accordance with the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1   a  shows a view of the standard PCI-express add-in card  10  with PCI-express male connector  11  (for example, X1, X4 or X8 type) located on the bottom edge  17  and a female socket  21  mounted at the upper edge  27  of main board  20  (“extender” case). On this  FIG. 1   a  said add-in card  10  and said main board  20  are located separately. According to [1], said PCI-express add-in card  10  comprises a male plug  11 , a bottom hole tab  13  (bottom mounting hole for bracket is placed on this tab) and a short tab  15 . These tabs  13  and  15  and said plug  11  are located on bottom edge  17  of said add-in card  10 . They are made of the same material as said PCI-express card  10  and are also their continuation. The height of short tab  15  is defined by PCI-express specification [1] and is equal to 8.25 mm. The length of PCI-express male connector  11  depends of the numbers of links (equal to 28.3 mm in case (X1), 42.3 mm in case (X4), and 59.3 mm in case (x8)). The length of the PCI-express add-in card has to be more than 65.30 mm and less than 312.00 mm [1]. The majority of the PCI-express add-in cards have a length close to 165.65 mm (half length) or 312.00 mm (full length). On  FIG. 1   a  the following edges are designated also: edge  18  intended for the fastening of bracket (bracket edge) and opposite edge  19 . 
     FIG. 1   b  shows the case when said plug  11  of said add-in card  10  is inserted into socket  21  mounted on main board  20 . The PCI-express add-in card is fastened only by socket  21  in this case. 
   In  FIG. 2  the standard X16 type PCI-express add-in card  10  according to [1] is shown. This card  10  comprises plug  11 , short tab  15  and “hockey stick”  31  (for fastened said card when this card is inserted into a socket). This “hockey stick”  31  exists only on the X16 type of the PCI-express add-in card [1]. In this case the main board has to provide a special mechanism (not shown) for the fastening of said “hockey stick”  31 . 
   In  FIG. 3  the present invention is shown for the case when the main board is an extender type.  FIG. 3  shows two fragments. The first fragment is of said PCI-express card  10  (the below view). Tab  13 , short tab  15  and PCI-express plug  11  are shown. Separately are denoted bottom end edge  151  of short tab  15  and the bottom end edge  171  of PCI-express add-in card  10 . 
   The second fragment is of extender card  20 . It comprises female socket  21  mounted at upper end edge (lateral surface)  271 . At this end edge  271  two support tabs are located, for example: the first support tab ( 26 ) and the second support tab ( 25 ) and the upper end edge ( 251 ) of the short tab ( 25 ) and the upper end edge ( 261 ) of the opposite located tab  27 . These two support tabs ( 25  and  26 ) are made of the extender material as one piece (one material). 
   In  FIG. 4  the cross view of the PCI-express add-in card  10  and the main printed circuit board  20  are shown according to the present invention. In  FIG. 4   a  and  FIG. 4   b  the PCI-express standard add-in card  10  comprises tab  13 , short tab  15  and PCI-express male plug  11 . In  FIG. 4   a  the PCI-express standard add-in card ( 10 ) is represented separately from main printed circuit board  20 , for example, PCI-express extender card. Main board  20  comprises female socket  21 , the first support tab ( 26 ) and the second support tab ( 25 ). 
   In  FIG. 4   b  the PCI-express standard add-in-card ( 10 ) is represented in the case when PCI-express male plug  11  is inserted into female socket  21 . Support tabs  25  and  26  are located on the two opposite parties of socket  21  and stabilize said PCI-express card  10  in socket  21  in place, thus removing the possibility of electric connection infringement. In most cases it is enough to have only one support tab. This  FIG. 4   b  shows that the geometric form and the position of these support tabs is limited by the edges of the PCI-express add-in card and socket  21 . In these figures all tabs have a flat top part for simplicity.  FIG. 4   b  shows that support tab  25  touches to said short tab  15  (more exactly the bottom end edge  251  of tab  15 — FIG. 3 ) and support tab  26  touches to the bottom end edge  271  of PCI-express add-in card  10 — FIG. 3 ). 
   In  FIG. 5  an example from [1] is shown. The two PCI-express female sockets  41  (one of them type X1 and another type X16) are placed on the plane surface  47  of said main board  40  (“motherboard” type). 
     FIG. 6  shows the support tabs in case the main board  40  is a motherboard type according to the present invention. These support tabs ( 45  and  46 ) can have a width no less than the PCI-express add-in card width. It is shown with the help of two imaginary planes  51  and  52 . The geometric form of the displayed support tabs  45  and  46  is chosen conveniently for fastening the said support tabs on the surface ( 47 ) of motherboard  40 . 
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