Abstract:
A removable tool includes a toe, a clevis, and a handle. The toe is configured to be insertable into and removable from an enclosure notch of a card guided computer enclosure. The clevis is configured to be insertable into and removable from a card hook of a circuit card assembly. The handle is for receiving force for inserting or extracting an array of circuit card assembly contacts into or out of an array of motherboard contacts, respectively.

Description:
BACKGROUND 
       [0001]    The present invention relates to card guided computer enclosures with removable circuit card assemblies, and, more specifically, to a removable tool for inserting and/or extracting the circuit card assemblies. 
         [0002]    Many computers include card guided computer enclosures that allow various circuit card assemblies to interface with the computer&#39;s motherboard. The interface involves a circuit card assembly with a connector mating with a corresponding connector on the motherboard. Each of these connectors have a number of contacts interfacing with a corresponding number of motherboard contacts. While the mating force between individual contacts is relatively small, the large number of contacts (for example, several hundred) means that the total force required to insert and/or extract the circuit card assembly may be quite large. 
         [0003]    Therefore, the prior art has solved this problem by using levers that are attached to either the card guided computer enclosure or the circuit card assemblies. Because the levers are attached, each slot or card needs a set of levers and the levers remain with the computer at all times, even when the levers are not in use. 
       SUMMARY 
       [0004]    According to the present invention, a removable tool includes a toe, a clevis, and a handle. The toe is configured to be insertable into and removable from an enclosure notch of a card guided computer enclosure. The clevis is configured to be insertable into and removable from a card hook of a circuit card assembly. The handle is for receiving force for inserting or extracting a circuit card assembly with an array of contacts into or out of an array of motherboard contacts, respectively. 
         [0005]    In another embodiment, a system arrangement includes a removable tool, a card guided computer enclosure, and a circuit card assembly. The card guided computer enclosure includes an enclosure notch having a notch top and a notch bottom configured to receive the removal tool toe between the notch top and the notch bottom. The circuit card assembly includes a card hook having a hook top and a hook bottom configured to receive the removal tool clevis between the hook top and the hook bottom. 
         [0006]    In another embodiment, a computer includes a card guided computer enclosure and a circuit card assembly positioned in the card guided computer enclosure. The card guided computer enclosure includes two enclosure notches opposite sides of the card guided computer enclosure, with each enclosure notch being configured to receive a removable tool. The circuit card assembly includes two card hooks on opposite sides of the circuit card assembly, with each card hook being configured to receive the removable tool. Each enclosure notch is adjacent to one of the card hooks. 
         [0007]    In another embodiment, a method of inserting a circuit card assembly into a card guided computer enclosure includes positioning the circuit card assembly into the card guided computer enclosure. A toe of a removable tool is positioned into an enclosure notch on the card guided computer enclosure, and a clevis of the removable tool into a card hook on the circuit card assembly. Force is exerted on the removable tool, while maintaining the toe in the enclosure notch and the clevis in the card hook, until an array of card contacts are inserted into an array of motherboard contacts. The toe is removed from the enclosure notch and the clevis is removed from the card hook, and the removable tool is removed from the card guided computer enclosure and the circuit card assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1A  is a front section view of a computer including a card guided computer enclosure and a circuit card assembly. 
           [0009]      FIG. 1B  is a front section view of the computer including a plurality of leverage arrangements. 
           [0010]      FIG. 1C  is a perspective section view of the computer including an extracted circuit card assembly. 
           [0011]      FIG. 2A  is a front view of the leverage arrangement during insertion of the circuit card assembly. 
           [0012]      FIG. 2B  is a front view of the leverage arrangement during extraction of the circuit card assembly. 
           [0013]      FIG. 3A  is a perspective view of the removable tool. 
           [0014]      FIG. 3B  is a perspective view of a card frame including a clevis. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    In  FIG. 1A , a front view of computer  10  including card guided computer enclosure  12  and circuit card assembly  14  is shown. In  FIG. 1B , a front view of card guided computer enclosure  10  including two leverage arrangements  16  is shown. In  FIG. 1C , a perspective view of card guided computer enclosure  12  including an extracted circuit card assembly  14  is shown.  FIGS. 1A-1C  will be discussed simultaneously. 
         [0016]    In the illustrated embodiment, computer  10  is a flight control computer for an aircraft, although computer  10  can be any type of computer that includes card guided computer enclosure  12  and at least one circuit card assembly  14 . Card guided computer enclosure  12  has motherboard  20  (with motherboard connector contact arrays  22 ) and a plurality of card guides  24 . Each card guide  24  includes enclosure notch  26 . Each circuit card assembly  14  includes connector contact arrays  28  and card frame  30  (with two card hooks  32 ). When a circuit card assembly  14  is inserted into card guided computer enclosure  12 , each enclosure notch  26  is adjacent to a card hook  32 . 
         [0017]    When a circuit card assembly  14  is inserted into card guided computer enclosure  12  and removable tool  18  is in place (as shown in  FIG. 1B ), there are two leverage arrangements  16 . In the illustrated embodiment, each leverage arrangement  16  is at an end of card guide  24  that is distal from motherboard  20 . Removable tool  18  is a lever comprising toe  34 , clevis  36 , and handle  38 . Toe  34  is at one end of removable tool  18  and handle  38  is at the opposite end. Between these two features is clevis  36 . Thereby, removable tool  18  is a class two lever, meaning that force is exerted at one end (handle  38 ), the fulcrum is at the opposite end (toe  34 ), and the resistance load is in the middle (clevis). 
         [0018]    In order to insert circuit card assembly  14  into card guided computer enclosure  12 , circuit card assembly  14  is positioned between a pair of card guides  24 . Circuit card assembly  14  is slid towards motherboard  20  until card contact arrays  28  contact motherboard contact arrays  22 . Then two removable tools  18  are used to insert card contact arrays  28  into motherboard contact arrays  22 . This occurs for each removable tool  18  by positioning toe  34  into enclosure notch  26  and clevis  36  into card hook  32 . Then force is exerted onto handle  38  along insertion direction  40  (which occurs substantially simultaneously for both removable tools  18 ). Because enclosure notch  26  constrains toe  34 , there is a resulting force on card engagement are  32  that urges circuit card assembly  14  towards motherboard  20 . If the force is sufficient, card contact arrays  28  will overcome the friction force of motherboard contact arrays  22  and circuit card assembly  14  will be inserted into card guided computer enclosure  12 . Once this occurs, removable tools  18  can be removed from card guided computer enclosure  12  and circuit card assembly  14 . Then, a cover (not shown) can be installed on card guided computer enclosure  12 , opposite of motherboard  20 . 
         [0019]    Removable tools  18  can also be used to extract circuit card assembly  14  from card guided computer enclosure  12 . To do so, each removable tool  18  is positioned such that toe  34  is in enclosure notch  26  and clevis  36  is in card hook  32 . Then force is exerted onto handle  38  along extraction direction  42  (which occurs substantially simultaneously for both removable tools  18 ). Because enclosure notch  26  constrains toe  34 , there is a resulting force on card hook  32  that urges circuit card assembly  14  away from motherboard  20 . If the force is sufficient, card contact arrays  28  will overcome the friction force of motherboard contact arrays  22  and circuit card assembly  14  will be extracted from card guided computer enclosure  12 . Once this occurs, removable tools  18  are removed from card guided computer enclosure  12  and circuit card assembly  14 , and circuit card assembly  14  can be slid out from between card guides  24 . A cover (not shown) can not be installed over enclosure  12  and circuit card assembly  14  with removable tools  18  still in place. This prevents removable tools  18  from being left inside computer  10  after insertion of circuit card assembly  14 . 
         [0020]    The components and configuration of computer  10  allow for circuit card assembly  14  to be inserted into and extracted from card guided computer enclosure  12  with minimal effort by the assembler. This is because the leverage ratio of the lever is at least 4:1, with the illustrated embodiment depicting a 5:1 radio. In addition, handle  38  is angled upward when in use, which provides the user with clearance for his or her fingers to exert force on handle  38 . Also, the cover (not shown) cannot be installed with removable tool  18  still in place, which prevents removable tool  18  from being left inside computer  10  after insertion of circuit card assembly  14 . 
         [0021]    In the embodiment shown in  FIGS. 1A-1C , a unitary card frame  30  is shown. Such an arrangement provides stiffness for circuit card assembly  14 . Although for the purposes of the present invention, there can be two card frames  30  with each card frame having its own clevis  36 . 
         [0022]    In  FIG. 2A , a front view of leverage arrangement  16  during insertion of circuit card assembly  12  is shown. Leverage arrangement  16  is as described previously in  FIGS. 1A-1C  with additional details provided. For example, enclosure notch  26  includes notch top  44 , and card hook  32  includes hook bottom  46 . 
         [0023]    When removable tool  18  has toe  34  positioned in enclosure notch  26 , clevis  36  positioned in card hook  32 , and force applied in insertion direction  40 , toe  34  contacts notch top  44  and clevis  36  contacts hook bottom  46 . Notch top  44  constrains the movement of toe  34 , which results in a force applied by clevis  36  onto hook bottom  46 . This causes circuit card assembly  14  to be inserted into card guided computer enclosure  12 . 
         [0024]    In addition, in  FIG. 2B , a front view of leverage arrangement  16  during extraction of circuit card assembly  12  is shown. Leverage arrangement  16  is as described previously in  FIGS. 1A-1C  with additional details provided. For example, enclosure notch  26  includes notch bottom  48 , and card hook  32  includes hook top  50 . When combined with the details provided in  FIG. 2A , enclosure notch  26  is a C-shaped feature while card hook  32  is a hook-shaped feature. 
         [0025]    When removable tool  18  has toe  34  positioned in enclosure notch  26 , clevis  36  positioned in card hook  32 , and force applied in extraction direction  42 , toe  34  contacts notch bottom  48  and clevis  36  contacts hook top  50 . Notch bottom  48  constrains the movement of toe  34 , which results in a force applied by clevis  36  onto hook top  50 . This causes circuit card assembly  14  to be extracted from card guided computer enclosure  12 . 
         [0026]    The components and configuration of leverage arrangement  16  allow for circuit card assembly  14  to be inserted into or extracted from card guided computer enclosure  12  using less force than if removable tool  18  was not used. This is because, as stated earlier, removable tool  18  acts as a lever. Because toe  34  is much closer to clevis  36  than handle  38  is to clevis  36 , removable tool  18  provides at least a 4:1 leverage ratio (for example, a 5:1 leverage ratio is depicted). 
         [0027]    In  FIG. 3A , a perspective view of removable tool  18  is shown. As stated previously, toe  34  is at one end of removable tool  18  and handle  38  is at the opposite end. Between these two features is clevis  36 . In the illustrated embodiment, toe  34  is a rounded end of removable tool  18 . In addition, clevis  36  includes pin  52  that is supported by legs  54 . The configuration of removable tool  18  allows for clevis  36  to pass through card frame  30 . In addition, their round shapes allow for toe  34  and pin  52  to slide along notch top  44  and hook bottom  46 , respectively (during insertion as shown in  FIG. 2A ), and for toe  34  and pin  52  to slide along notch bottom  48  and hook top  50 , respectively (during extraction as shown in  FIG. 2B ). 
         [0028]    In  FIG. 3B , a perspective view of card frame  30  including card hook  32  is shown. As stated previously, card hook  32  as defined by card frame  30  has a hook-shape with hook top  50  and hook bottom  46 . More specifically, hook top  50  is a curved surface that turns toward hook bottom  46  at the free end of hook top  50 . This configuration of card frame  30  allows for clevis  36  to maintain contact with card frame  30  longer during extraction (as shown in  FIG. 2B ). 
         [0029]    The present invention provides various benefits and advantages. For example, removable tool  18  does not stay with computer  10 , which reduces the weight of computer  10 . For another example, two removable tools  18  can be used to insert and/or extract many different circuit card assemblies  14 , so having two removable tools  18  for every circuit card assembly  14  is not necessary. This reduces the cost of computer  10 . 
         [0030]    While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.