Patent Publication Number: US-2011069461-A1

Title: Card guide misalignment prevention apparatuses and methods

Description:
PRIORITY CLAIM 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/243,996, filed on Sep. 18, 2009, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The subject matter disclosed herein relates generally to card guides. More particularly, the subject matter disclosed herein relates to apparatuses and methods for preventing misalignment when using card guides. 
     BACKGROUND 
     Card-based systems, such as telecommunications equipment chassis, are designed to allow one or more cards or printed circuit boards (“PCBs”) to be inserted into shelves of a chassis. The cards typically include electrical connectors on their leading edges that are inserted into corresponding connectors in the chassis. The electrical connectors in the chassis into which cards are inserted are typically referred to as a plane, such as a mid-plane or backplane. The space limitations involved typically require cards to be inserted carefully and precisely to ensure proper coupling between the cards and the plane and to prevent damage to the plane and the cards. 
     To ensure proper coupling of cards within the chassis and help prevent damage to expensive equipment, card guides have conventionally been added to aid in card insertion. Card guides generally are slots or spaces between rails aligned so that cards can be slid on an edge or edges until connectors of the cards are inserted into connectors in the chassis (e.g. mid-plane connectors). For instance, a typical chassis or chassis may have holes for inserting card guide rails corresponding to the location of connectors in the chassis. When installing a card using conventional card guides, an edge of the card is placed in between two card guide rails associated with a connector of the plane. The card is moved on its edge until a connector of the card engages the associated plane connector. While conventional card guides direct cards to connectors in the chassis, it is still possible to misalign the cards (e.g., a card installer may overlook or miss the guides and insert the cards without using the guides), and, thus, cause damage to the system or its components. Accordingly, a need exists for apparatuses and methods for preventing card guide misalignment. 
     SUMMARY 
     In accordance with this disclosure, card guide misalignment prevention apparatuses and methods are provided. According to an embodiment of one apparatus, a card guide system for facilitating insertion of printed circuit boards (PCBs) into a telecommunications equipment chassis is disclosed. The card guide system includes a support member for supporting a plurality of pairs of parallel rails extending outward from the support member and across portions of a surface of the support member. Each pair of parallel rails forms a card guide for guiding a PCB across the surface to an electrical connector into which each PCB is inserted. The pairs of parallel rails are spaced from each other on the surface. The card guide system also include a plurality of misalignment prevention members extending outward from the surface of the support member between adjacent card guides for preventing PCB misalignment. The support member, rails, and misalignment prevention members are of unitary construction. 
     Methods for preventing misalignment of cards into a telecommunications equipment chassis are also disclosed. According to an embodiment of one method, the method includes providing electrical connectors in a telecommunications equipment chassis for engaging PCBs. The method also includes attaching a card guide system to the chassis for facilitating insertion of printed circuit boards (PCBs) into the chassis. The card guide system includes a support member for supporting a plurality of parallel rails extending outward from the support member and across portions of a surface of the support member. Each pair of parallel rails forms a card guide for guiding a PCB across the surface to an electrical connector into which each PCB is inserted. The pairs of parallel rails are spaced from each other on the surface. The card guide system also include a plurality of misalignment prevention members extending outward from the surface of the support member between adjacent card guides for preventing PCB misalignment. The support member, rails, and misalignment prevention members are of unitary construction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present subject matter including the best mode thereof to one of ordinary skill in the art is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which: 
         FIG. 1  is a perspective view of an embodiment of a card guide system according to the present subject matter herein; 
         FIG. 2  is a perspective view of a card being inserted into a chassis using the card guide system of  FIG. 1  according to the present subject matter herein; 
         FIG. 3  is a side view of an embodiment of a card guide and two misalignment prevention members of the card guide system of  FIG. 1  according to the present subject matter herein; and 
         FIG. 4  is a front view of a card being inserted into a chassis using two card guide systems of  FIG. 1  according to the present subject matter herein. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the description of the present subject matter, one or more examples of which are shown in the figures. Each example is provided to explain the subject matter and not as a limitation. In fact, features illustrated or described as part of one embodiment can be used in another embodiment to yield still a further embodiment. It is intended that the present subject matter cover such modifications and variations. 
       FIG. 1  illustrates one embodiment of a card guide system, generally designated  100 , that may be used in association with inserting or installing cards or printed circuit boards (PCBs) into a chassis. As used herein, the terms card and PCB may be used interchangeably and generally refer to any hardware, device, module, or component that connects into a chassis, or to a plane. As used herein, chassis generally refers to framework into which cards can be inserted or mounted. As used herein, plane system or plane generally refers to any hardware, device, module, or component for connecting one or more cards. As used herein, PCB connectors, chassis connectors, chassis connectors, plane connectors, electrical connectors, and any other related connection terminology generally refers to hardware for coupling or connecting cards, planes, chassis, and other devices. 
     It should be appreciated that various connections (e.g., ‘female’ connections, such as ports, sockets and ‘male’ connectors, such as pins, plugs) and various connection configurations are contemplated. For example, various connectors may be implemented at or on various devices (e.g., ‘male’ connectors at a plane and ‘female’ connectors at a card, ‘female’ connectors at a plane and ‘male’ connectors at a card, or an assortment of connector types for cards, chassis, and planes). Such various connections and configurations may be used without departing from the scope of the subject matter described herein. For illustrative purposes, connection hardware on cards herein will be referred to as PCB connectors and connection hardware in chassis herein will be referred to as chassis connectors and/or plane connectors (e.g., mid-plane connectors, backplane connectors). 
     Card guide system  100  may include one or more card guides  108  and one or more misalignment prevention members (MPMs)  102 . Card guides  108  are for guiding cards, and particularly cards&#39; PCB connectors, into connectors in a chassis (e.g., mid-plane connectors, backplane connectors, or other connectors). In one embodiment, each card guide  108  includes a surface substantially bordered on two sides by rails  104 . In one embodiment, a card guide  108  may include a pair of parallel rails  104  that extend outward from a surface of a support member  106  for guiding a PCB across the surface of support member  106  to an electrical connector into which each PCB is inserted. The pairs of parallel rails may be spaced from each other on the surface. Rails  104  may be any size or shape (e.g., slightly bowed or curved at edges). Rails  104  may include one or more discontinuities on the surface of the support member (e.g., portions of rails  104  may appear or be flat). Rails  104  may include a variety of structures for providing support or guidance for guiding a card along the surface of support member  106  between card rails  104 . For example, rails  104  may include any combination of clamps, raised edges, tabs, ridges, grooves, tensioned lines, wires, and strings. As shown in  FIG. 1 , each card guide  108  provides a path for an edge of a card to move (e.g., towards a plane or away from a plane). 
     MPMs  102  are for preventing card misalignment. For example, MPMs  102  may prevent or minimize damage to a plane, card, or other device (e.g., prevent a misaligned card from damaging connection pins, connection receptacles, or circuitry components). In one instance, one or more MPMs  102  may prevent insertion of PCBs into the electrical connectors of the chassis between card guides  108 . In some embodiments, MPMs  102  may be raised edges or tabs extending outward from a surface of support member  106  between card guides  108 . In alternate embodiments, MPMs  102  may include additional or alternate alignment support structures, such as clamps, rails, tabs, ridges, grooves, tensioned lines, wires, and strings. In the embodiment shown in  FIG. 1 , a plurality of MPMs  102  is shown extending outward from the surface of support member  106  between adjacent card guides for preventing PCB misalignment. In one embodiment, the tabs of MPMs  102  may be long and/or high enough to hinder or prevent a card from being incorrectly inserted into an electrical connector. In some embodiments, preventing a card from being improperly inserted may include requiring the card to be inserted using a card guide  108 . In the embodiment shown in  FIG. 1 , the tabs of MPMs  102  facilitate inserting PCBs between pairs of rails  104  of card guide system  100 . 
     Support member  106  may have a substantially planar surface, other than rails  104  and MPMs  102 . Support member  106  may provide support (e.g., structural support) to card guide system  100  and/or components of card guide system  100 . 
     Card guide system  100  may include one or more holes or apertures  110 . In one embodiment, apertures  110  are formed by extracting or removing one or more portions of support member  106  (e.g., punching holes in sheet metal). Each rail  104  may be adjacent to an aperture  110 . Each MPM  102  may be adjacent to an aperture  110  and may extend in a direction transverse to each rail  104 . MPMs  102  and/or the rails  104  may be formed by bending outwards edges of support member  106  that forms sides of each aperture  1110 . For example, MPMs  102  and/or card rails  104  may be formed by bending portions of support member  106  upwards, outwards, and/or at various angles from one or more portions of support member  106 . 
     In the embodiment shown in  FIG. 1 , support member  106  is shown for supporting a plurality of pairs of parallel rails  104  extending outward from support member  106  and across portions of a surface of the support member  106 . Support member  106  may include securing features, such as holes, overhangs, lips, brackets, indentions, and/or other like features, used in securing card guide system  100  in or to a plane chassis (e.g., a telecommunications equipment chassis). For example, screws, bolts, pins, ties, clips, and/or fasteners may be used for securing card guide system  100  to a media gateway chassis. Additional components or portions of card guide system  100  may include similar features. For example, support member  106  may include additional surfaces, sides, edges, or portions for securing card guide system  100 . Such surfaces may extend in various ways or directions and may include one or more securing features. 
     Card guide system  100 , including components of card guide system  100 , may be fabricated from any suitable rigid materials, including metals, metal alloys, rigid plastics, etc., using any suitable fabrication processes, including welding, machining, molding, casting, stamping, bending, punching, and pressing. Components of card guide system  100 , including card guide rails  104 , MPMs  102 , and support members  106 , may be fabricated using the same materials and/or same fabrication processes. Alternatively, different components or portions of card guide system  100  may be fabricated using different materials and/or fabrication processes. For example, a support member  106  may be fabricated using high-grade aluminum and card guide rails  104  may be fabricated using polytetrafluoroethylene-coated (e.g., Teflon®-coated) plastic. In one embodiment, card guide system  100  may be formed with components, such as an MPM  102  and rails  104 , attached (e.g., glued, fastened, or wielded) to a base portion or support member  106 . 
     In one embodiment, card guide rails  104 , MPMs  102 , and support members  106  may be of unitary construction. For example, support member  106  may a unitary sheet of metal, and MPMs  102  and rails  104  may be formed by bending outwards portions of the unitary sheet of metal. In another example, support member  106 , MPMs  102 , and rails  104  may be formed by using a molding or rapid prototyping process. 
       FIG. 2  illustrates a card  206  being inserted into a telecommunications equipment chassis  200 , such as a chassis of a media gateway, gateway controller, session border controller, or an element management system. As shown in the embodiment of  FIG. 2 , a plane  202  is attached to chassis  200  and includes electrical connectors, also known as chassis or plane connectors. Card  206  includes a PCB connector  208  for connecting or engaging a plane connector  204 . Card  206  may provide a service or function for telecommunications equipment (e.g., card may provide a network interface function or a digital signaling processing (DSP) function). Plane  202  represents a circuit board (e.g., a PCB) for connecting several cards  206  together. Depending on the usage and/or configuration, plane  202  may be referred to as various devices, including a backplane, mid-plane, or motherboard. For example, a plane  202  may be referred to as a backplane if cards or devices connect to one side of plane  202  and may be referred to as a mid-plane if cards or devices connect on two sides of plane  202 . 
     In  FIG. 2 , card  206  is being inserted into chassis  200  using a card guide  108  of card guide system  100 . As shown in the embodiment of  FIG. 2 , card guides  108  correspond to the location of plane connectors  204 . When installing or inserting card  206  into plane  202 , an edge of card  206  is placed in between two card guide rails  104  associated with plane connector  204 . Using card guide  108 , card  206  may be moved or slid on its edge until PCB connector  208  engages plane connector  204  or vice versa. 
     As noted above, it is desirable for cards  206  to be properly inserted into chassis  200 . As such, MPMs  102  may be used to prevent improper insertion of cards and/or prevent damaging to chassis  200  or plane  202 . In the embodiment shown in  FIG. 2 , one or more MPMs  102  facilitates use of card guides  108 . For example, insertion of a card  206  may be attempted at a MPM  102  but hindered or prevented by a raised edge or tab. The tab of MPM  102  may be any size and shape to prevent card  206  from moving forward (i.e., towards connectors of plane  202 ). To avoid MPM  102  (e.g., overcome the height of the tab), an installer may attempt to raise and insert card  206  above MPM  102 . In one embodiment, tab of MPM  102  is high enough to prevent a card&#39;s PCB connector  208  from engaging a plane connector  204 . An additional or alternative feature of MPM  102  may include the top of card  206  meeting a barrier (e.g., a shelf or component that is located above card guide system  100 ) if card  206  is attempted to be inserted above MPM  102 . Hence, MPMs  102  may be used to prevent improper insertion of card  206  into plane  202 . While  FIG. 2  depicts MPM  102  including a raised edge or tab, it should be appreciated by one of ordinary skill in the art that any support or guidance structures may be used to prevent card misalignment and/or prevent damage to plane  202 . For example, MPM  102  may include one or more clamps, raised edges, tabs, rails, ridges, grooves, tensioned lines, wires, and strings. 
       FIG. 3  illustrates a card guide  108  and two MPMs  102  of card guide system  100 . In particular,  FIG. 3  depicts a front section of card guide system  100  where a card may be place in card guide  108  between rails  104 . Rails  104  may help direct the card along its edge (e.g., towards a plane connector of a plane or away from the plane connector). In the embodiment shown in  FIG. 3 , MPMs  102  include tabs extending outward from the surface of card guide system  100  for preventing a card from being inserted into a plane without using card guide  108 . In one embodiment, MPMs  102  are taller than rails  104  of card guide  108 . In an alternative embodiment, MPMs  102  are the same height or shorter than rails  104 . In the embodiment shown in  FIG. 3 , MPMs  102  are about the same height as rails  104 . In one embodiment, space exists between MPMs  102  and rails  104 . In this embodiment, space between MPMs  102  and rails  104  may be less than the width, depth, or other dimension of a card. By limiting the amount of space between MPMs  102  and rails  104 , the likelihood that cards will be misaligned is reduced (e.g., a card may not fit in a gap between a MPM  102  and a rail  104  that is smaller than the width of the card&#39;s edge). Hence, small spaces between MPMs  102  and rails  104  may prevent cards from being inserted without using a card guide  108 . In an alternative embodiment, MPMs  102  and rails  104  meet, touch, or are adjoined in such a way that no space is between MPMs  102  and rails  104 . 
     It will be appreciated that multiple card guide systems  100  or portions thereof may be attached to or used in a telecommunications equipment chassis  200 . In some embodiments, a chassis may include multiple card guide systems  100  for connecting PCBs  206  to electrical connectors  204  that are of various types and/or arrangements, such as groups, rows, stacks, racks, or shelves. For example, telecommunications equipment chassis  200  may include a mid-plane  202  where a first side of mid-plane  202  includes connectors  204  for accepting voice processing cards (e.g., DSP cards) and a second side of mid-plane  202  include connectors  204  for accepting network interface cards (NICs). Each side may have one or more card guide systems  100 . In a second example, a chassis may include a plurality of shelves for PCBs  206 . In this example, the chassis  200  could include multiple plane systems  202  at different heights or one or more planes  202  with stacked connectors  204 . Each shelf may have one or more card guide systems  100 . For example, a shelf may have a group of plane connectors  204  for connecting cards  206 . A first card guide system  100  may be attached at or near the bottom of the shelf for guiding a bottom portion of cards  206  and a second card guide system  100  may be attached at or near the top of the shelf for guiding a top portion of cards  206 . 
       FIG. 4  illustrates a card  206  being inserted into a telecommunications equipment chassis  200  using two card guide systems  100 . As shown in the embodiment of  FIG. 2 , a plane  202  is attached to chassis  200  and includes electrical connectors, also known as chassis or plane connectors. Card  206  includes a PCB connector  208  for connecting or engaging an electrical connector in the chassis  200 . Card guide system  100 , including card guides  108 , correspond to the location of electrical connectors in the chassis  200 . For example, a first card guide system  100  may be attached substantially at or below electrical connectors in the chassis  200  (e.g., connectors of plane  202 ) and an inverted second card guide system  100  may be attached substantially at or above electrical connectors in the chassis  200  (e.g., connectors of plane  202 ). The first and second card guide systems  100  may be aligned such that card guides  108  from top card guide system  100  and card guides  108  from bottom card guide system  100  guide cards  206  to electrical connectors in the chassis  200  (e.g., connectors of plane  202 ). 
     In the embodiment shown in  FIG. 4 , first card guide system  100  is attached above the electrical connectors in chassis  200  and second card guide system  100  is attached below the electrical connectors in chassis  200 . A card guide  108  from first card guide system  100  is aligned to guide a top edge of card  206 . A corresponding card guide  108  from second card guide system  100  is aligned to guide a bottom edge of card  206 . The alignment is such that connector  208  of card  206  engages an electrical connector in the chassis  200 . MPMs of first and second card guide systems  100  prevent the top and bottom edges of card  206  from being misaligned. 
     Embodiments of the present disclosure shown in the drawings and described above are exemplary of numerous embodiments that can be made within the scope of the appending claims. It will be understood that various details of the subject matter described herein may be changed without departing from the scope of the subject matter described herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the subject matter described herein is defined by the claims as set forth hereinafter.