Abstract:
A hot docking mechanism enables a PCI type card with an edge connector to be inserted into an enclosure and docked in a card socket on the motherboard without operator access to the enclosure interior. A card holder carries the card and is supported on a card guide for sliding motion into the enclosure to a position at which the edge connector is aligned with the socket secured to the device motherboard. A camming assembly includes a cam lever extending outside the enclosure to convert horizontal or pivoting motion of the cam lever to vertical motion of the card into and out of the socket. The camming assembly, mounted above and proximate the mother board surface, increases mechanical advantage during docking and undocking. The card is supported within the card holder and the camming connection between the card and camming assembly is disposed intermediate the longitudinal ends of the socket to maximize mechanical advantage and minimize misalignment during card docking and undocking.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to printed circuit card installation in electronic devices. More particularly, the invention relates to a structure and method for auto docking electronic cards engaged by a carrier to be “hot plugged” into an electronic device. 
     Electronic equipment technicians, and indeed some private individuals as well, are aware that printed circuit boards (PCB) are employed within many pieces of electronic equipment. It is also known by these individuals that these “cards” can in some cases be removed for repair of a device or an upgrade thereof or simply to alter the operating parameters thereof. Most notable are computer devices where different functions or memory capacity can be needed. 
     Conventionally, the changing of a card is done by removing the cover of the machine and manually removing the existing card and plugging in a new one. This procedure may be complicated further in systems where entire banks of cards must be removed above the one being replaced or the bank of cards where one is to be replaced must removed. In such instances the machine must be shut down. Since both the shut down and start up procedure can be time consuming, shut down is undesirable. 
     More recently, some electronic equipment has been designed to accept a card carrier comprising a frame with means to insert the card into an electrical receptacle while the cover is still in place on the device. This type of an operation is known as “hot plugging”. While the existing hot plugging PCI card carriers are effective and beneficial for their intended purpose, they are card specific. Unfortunately, then, one needs a specific carrier for every type of card he wishes to use. 
     Examples of such carriers are described in detail in U.S. Pat. No. 6,071,143, filed Dec. 13, 1996, U.S. Pat. No. 5,868,585, filed Dec. 13, 1996, and U.S. Pat. No. 5,815,377, filed Dec. 8, 1997, all assigned to the assignee hereof and all of which are fully incorporated herein by reference. 
     In mid sized or mini computers it is common to have continuous operation of the computer system. Thus, the installation or replacement of peripheral devices must be effected by hot plugging without disturbing system operation. However, PCI cards, in the normal environment, are installed when the device is shut down and the covers removed for card installation and removal. To realize the benefits of PCI card use, it is necessary to find a means to accomplish hot plugging of such cards while protecting the user from the electrical hazards of an operating, electrically energized system, while minimizing the space needed to employ such a capability. Moreover, mainly for reasons associated with long-term system operation and reliability, it is likewise very desirable to be able to easily insert and remove these printed circuit cards even when they are disposed in very tight spaces. The insertion and removal operations are also provided as an important part of a “hot-pluggability” function which is very desirable for “on the fly” repairs, replacements, maintenance and upgrades. 
     With increased circuit density there has also been a concomitantly driven increase in the number of power, signal and control lines which require electrical connections to be made between printed circuit cards and printed circuit boards. This means that the electrical connectors that carry these various electrical circuits between the cards and the boards have been required to carry more and more separate individual connections. A significant consequence of the increase in the number of individual electrical connections, all of which require surety of contact, is the corresponding increase in the force needed to insert printed circuit connectors into mating printed circuit board sockets. This aspect provides special design considerations for card holders that carry printed circuit cards which are meant to be inserted into printed circuit boards via actuating mechanisms. 
     It is also noted that the present discussion refers to printed circuit boards and printed circuit cards. As contemplated herein, the printed circuit board is the larger component into which at least one printed circuit card is inserted for purposes of electrical connection. The present disclosure places no specific limits on either the size of a printed circuit board or the size of a printed circuit card. In the most general situation, a circuit board will be populated with a plurality of printed circuit cards. That is, the printed board will have a number of printed circuit cards inserted therein. Accordingly, as used herein, the terms “printed circuit board” and “printed circuit card” are considered to be relative terms. 
     Accordingly, the present inventors are presented with the following sometimes competing packaging problems: connector pin alignment, card holder alignment, rigid connection to a printed circuit board, dense and close packaging, hot pluggability, the desire to provide an easy-to-load card holder for carrying printed circuit cards, and mechanisms requiring a mechanical advantage for insertion and removal of printed circuit cards. 
     SUMMARY 
     The problems associated with hot plugging of PCI cards is resolved using a card holder that slides into the enclosure prior to electrical connection. The card is aligned with the connector when fully inserted and is thereafter cammed into the cooperating connector. The camming assembly is mounted on a surface above and proximate the mother board where it provides mechanical advantage during insertion and removal of the PCI card. 
     The card holder includes a translatable location of support slidably connected to the card holder for mounting edges of the circuit card thereon. A guide assembly is mounted within the enclosure on the surface above and proximate the mother board for slidably supporting and guiding the card holder into the enclosure to a position whereat a circuit card connector of the card is aligned with a card socket extending from the mother board. The camming assembly includes a cam mechanism providing mechanical advantage when a cam mechanism is operated outside of the enclosure to move said card holder toward the mother board and insert the circuit card connector into the socket. The cam lever extends outside the enclosure to convert horizontal or pivoting motion of the cam lever to vertical motion of the card into and out of the socket. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of practice, together with the further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a perspective view of a card holder, card guide and cam mechanism of one exemplary embodiment and a PCI card engaged in a socket extending from a mother board and through a guide surface with which the docking assembly cooperates; 
     FIG. 2 is a perspective side view from an opposite side of the docking assembly of FIG. 1; 
     FIG. 3 is a side elevation view of the docking assembly of FIGS. 1 and 2; 
     FIG. 4 is a perspective view of a card holder, card guide and cam mechanism of an alternative embodiment of the docking assembly of FIG. 1; 
     FIG. 5 is a side elevation view of the card holder, card guide and cam mechanism of FIG. 4; 
     FIG. 6 is a perspective view of a card holder, card guide and cam mechanism of another alternative embodiment of a docking assembly; 
     FIG. 7 is a is a perspective side view from an opposite side of the docking assembly of FIG. 6; 
     FIG. 8 is a side elevation view of the card holder, card guide and cam mechanism of FIG. 7; 
     FIG. 9 is a side elevation view of an alternative embodiment of a card holder cooperating with a cam mechanism; and 
     FIG. 10 is a side elevation view of an alternative embodiment of a card holder cooperating with a cam mechanism of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a perspective view of the parts of one exemplary embodiment of a card docking apparatus of the present disclosure and the mother board  10  with the connector  12  mounted thereon which receives the card edge connector  12 . The PCI card  13  is carried by the card holder  15 . Card holder  15  has at least one bifurcated carrier  16  slidably mounted to card holder  15 . Card holder includes a tail stock bezel  18  mounted to a tail end of card holder  15 . Tail stock bezel  18  slidably contains a window bracket  20  that is attached to card  13 . Tail stock bezel  18  is preferably in slidable electrical contact with bracket  20  having an EMC seal therebetween disposed along flanges  22  of bezel  18 . One end  24  of window bracket is slidably received in an aperture  26  in a guide surface  28  above motherboard  10  when card edge connector  12  of card  13  is connected to socket  11  to prevent card holder  15  from being removed while edge connector  12  is plugged in socket  11 . 
     Each card holder is received in a guide  30  defined by contiguous flanges  32  formed in guide surface  28 . Flanges  32  are preferably formed by cutting three sides of a rectangle in surface  28  while folding the flange substantially perpendicular to surface  28  along a fourth side defining a fourth side of the rectangle. In this manner a socket aperture  34  is formed to receive socket  11  through guide surface  28 . Guide surface  28  is preferably formed of stamped electrically conductive metal. 
     A guide assembly  38  is mounted within guide  30  offset to one side between flanges  32  defining guide  30  to allow space for card holder  15  to slide therethrough. More specifically, guide assembly  38  comprises a base  40  from which a guide wall  42  extends substantially perpendicular to base  40 . Base  40  is preferably aligned and mounted to guide surface  28  using protrusions  43  extending from said base  40  through holes  44  configured in guide surface  28  and then securing base  40  to guide surface  28  using rivets  46 , for example. 
     Guide wall  42  includes a first slot  48  extending from one end of wall  42  to an intermediary portion of wall  42  in a horizontal direction. First slot  48  further includes a second slot  50  extending substantially perpendicular towards socket  11  at the intermediary portion of wall  42 . First and second slots  48 ,  50  are configured to receive a pin  52  extending from carrier  16  to guide card  13  within card holder  15  when card holder is installed or removed from motherboard  10 . 
     Referring to FIG. 2, a second guide assembly  38  is disposed on the other side of card holder  15  in a contiguous guide  30  having a contiguous socket  11  extending through a contiguous aperture  34  for mounting another card holder  15 . It will be noted that the wall  42  of the second guide assembly includes a third slot  54  substantially parallel to said first slot for receipt of a pin element  56  extending from card holder  15  to guide the other side of card holder  15  in guide  30 . It will be further recognized that third slot  54  begins in a bight portion  58  configured in wall  42 . Bight portion  58  is configured to guide a bottom portion of pin  56  while alignment pin  52  in slot  48  on the opposite side of card holder  15  can be concentrated on. Furthermore, it will be recognized that first and second slots  48 ,  50  on the second guide assembly are unoccupied to receive another card holder  15  for connection with the second socket  11 . It should be noted that although card holder has been described as being slidably mounted between two guide assemblies  38 , a single guide assembly  38  is optionally employed on a single side of card holder  15 . 
     Referring now to FIG. 3, a cam assembly  60  is disposed between wall  42  of guide assembly  38  and card holder  15 . Cam assembly  60  includes an actuating cam lever  62  extending outside of the enclosure at one end and is preferably pivotally mounted to wall  42  via aperture  66 . Cam lever  62  is pivotally mounted to wall  42  at aperture  66  (see FIG. 2) using a rivet  68 , for example, or the like. It will be appreciated that cam lever  62  is alternatively pivotally mounted to card holder  15 . Cam lever  62  further includes a horizontal slotted opening  70  configured to receive pin  52 . 
     As discussed above, pin  52  is operably connected to card  13  via carrier  16 . Carrier  16  includes two vertical parallel guide slots  72  each configured to receive a pin  74  extending therethrough from card holder  15 . Parallel slots  72  are configured to restrict translation of card  13  via carrier  16  in a direction to and away from socket  11 . More specifically, when cam lever  62  pivotally actuated at the one end, pin  52  within slot  70  is pivoted in an arc defined by a distance between rivet  68  and pin  52 . However, because pin  52  is restricted to translate in a vertical direction by containment within slot  50  and by its association with parallel guide slots  72 , horizontal slotted opening  70  permits pin  52  to deviate from moving in the arc created by pivoting cam lever  62 . 
     In operation, card holder  15  is manually guides into guide  30  aligning pin  52  in horizontal slotted opening  48 , and preferably engages pin  56  on the other side of card holder  15  in horizontal slotted opening  54  in a contiguous card guide assembly  38 . Pin  52  is thereinafter received in horizontal slotted opening  70  of cam assembly  60  and aligned with vertical slot  50  when card holder  15  is fully inserted. By pivotally moving cam lever  62  towards guide surface  28 , an upper surface defining an upper portion of horizontal slotted opening  70  urges pin  52  towards socket  11 , thus urging card connector  12  to be electrically coupled with socket  11 . Similarly, movement of cam lever  62  away from guide surface  28  causes a bottom surface defining a bottom portion of horizontal slotted opening  70  to urge pin  52  away from socket  1  land drives card connector  12  out of electrical connection with socket  11 . In addition, pin  52  is then aligned with horizontal slotted opening  48  for removal of card holder  15  from the enclosure. It will be recognized that significant mechanical advantage is added by biasing cam lever  62  extending from rivet  68  to engage/disengage card connector  12  with socket  11 . 
     Referring to FIGS. 4 and 5, an alternative embodiment of a docking apparatus is illustrated. FIG. 4 is a perspective view of the parts of card docking apparatus with the connector  12  of card  13  prior to electrically coupling with socket  11 . Card holder  15  includes a bifurcated carrier  16   a  and  16   b  slidably mounted to card holder  15 . Card holder  15  includes tail stock bezel  18  mounted to a tail end of card holder  15 . Tail stock bezel  18  slidably contains window bracket  20  attached to card  13 .  11 . In an exemplary embodiment and still referring to FIG. 4, the printed circuit card holder assembly preferably receives and removably retains edges of a PCI card  15 . PCI card  13  is carried by the card holder  15  having two bifurcated arms or carriers  16   a  and  16   b . Each of the carriers  16   a  and  16   b  present slots (not shown) configured to grasp an edge portion of card  13 . Carrier  16   b  is slidable along an extension arm (not shown) formed integrally with and extending from carrier  16   a  for adjustably grasping other sized cards  15 . Such carriers or arms are shown and fully described in U.S. Pat. No. 6,062,894 assigned to the assignee of the present application and is incorporated by reference. 
     Guide assembly  38  is mounted within guide  30  offset to one side between flanges  32  defining guide  30  to allow for space for card holder  15  to slide therethrough (see FIG.  1 ). More specifically, guide assembly  38  comprises base  40  from which guide wall  42  extends substantially perpendicular to base  40 . Base  40  is preferably aligned and mounted to guide surface  28  using protrusions  43  extending from said base  40  through holes  44  configured in guide surface  28  and then secured using rivets  46 , for example. 
     Guide wall  42  includes a first slot  48  extending from one end of wall  42  to an intermediary portion of wall  42  in a horizontal direction. First slot  48  is configured to receive pin  52  extending from card holder  15  to guide card holder  15  when card holder is installed or removed from motherboard  10 . A second slot  50  extends substantially perpendicular towards socket  11  relative to first slot  48  proximate an intermediate section of wall  42  and disposed above and intermediate a longitudinal length of socket  11 . Second slot  50  is configured to receive a pin  80  extending from carrier  16   a  to guide card  13  within a vertical direction when card  13  is installed or removed from socket  11  in motherboard  10 . It will be further recognized that first slot  48  begins at a bight portion  82  configured in wall  42 . Bight portion  82  is configured to facilitate guiding a bottom portion of pin  52  while inserting card holder  15  into the enclosure. 
     Still referring to FIGS. 4 and 5, cam assembly  60  is disposed between wall  42  of guide assembly  38  and card holder  15 . Cam assembly  60  includes actuating cam lever  62  extending outside of the enclosure at one end and is connected to a slidable wall  84  slidably connected to card holder  15 . Slidable wall  84  is configured to translate in a horizontal direction relative to translation of card  13  in a vertical direction. Slidable wall  84  includes a first inclined slotted  86  opening that is parallel to a second inclined slotted opening  88 , both configured in wall  84  to allow horizontal translation of wall  84  while translating carrier  16  in a vertical direction via pins  52  and  92  depending to carrier  16  and extending through slotted openings  86 ,  88 . More specifically pin  52  extends through first inclined slotted opening  86  and pin  92  extends through second inclined slotted opening  88 . 
     As discussed above, pin  52  is operably connected to card  13  via carrier  16 . Carrier  16  includes two vertical parallel guide slots  72  each configured to receive pin  74  extending therethrough from card holder  15 . Parallel slots  72  are configured to restrict translation of card  13  via carrier  16  in a direction to and away from socket  11 . More specifically, when cam lever  62  connected to slidable wall  84  is urged toward card holder  15 , slidable wall  84  translates in a horizontal direction toward carrier  16   b  causing pins  80  and  92  fixed to carrier  16   a  to translate in a vertical direction as a result of pins  80 ,  92  residing in inclined slotted openings  86  and  88 , respectively, and pins  74  residing in slots  74  restricting translation of pins  74  within slots  72  to vertical translation. Moreover, containment of pin  80  within second slot  50  of guide wall  42  restricts movement of card  13  to vertical translation when cam lever  62  is horizontally actuated. 
     In operation, card holder  15  is manually guided into guide  30  aligning pin  52  in horizontal slotted opening  48 . Once pin  52  is fully inserted within horizontal slotted opening  48 , further translation of card  13  in the horizontal direction is not possible, unless card holder is manually removed from the enclosure. By urging cam lever  62  towards guide wall  42 , slidable wall  84  connected to cam lever  62  is also urged to the left relative to FIGS. 4 and 5. When slidable wall  84  is urged to the left, inclined slots  86  and  88  guide pins  80 ,  92  enclosed therein, respectively, downward because of parallel inclined slots  86  and  88  slant downward. Pins  80  and  92  are biased downward because pins  80  and  92  are operably connected with carrier  16   a  which is restricted to vertical motion as a result of slots  72  in carrier  16   a  having fixed pins  74  within slots  72 . Thus, horizontal motion of slidable wall  84  to the left urges pins  80  and  92  towards socket  11 , thus urging card connector  12  to be electrically coupled with socket  11 . Similarly, movement of cam lever  62  to the right as shown in FIGS. 4 and 5 causes translation of slidable card to the right which in turn urges pins  80  and  92  away from socket  11  and drives card connector  12  out of electrical connection with socket  11 . It will be recognized by one skilled din the pertinent art that slots  86  and  88  may be configured having an opposite incline angle, e.g., incline from left to right. In such a case, translation of cam lever  62  to the left drives card connector  12  out of electrical connection with socket  11  and translation to the right drives card connector  12  into electrical connection with socket  11 . 
     Referring to FIGS. 6-8, another alternative embodiment of a cam assembly  160  for use with a docking apparatus is illustrated. Cam lever  62  is operably actuated by manually urging cam lever  62  in a horizontal direction as before. Cam lever  62  is operably linked to a cam link  92  at one end while an opposite end cam link  92  is configured with a slotted opening  70  configured to receive pin  52  operably connected to card  13 . When cam link  92  is in a first position shown generally at  94 , slotted opening  70  is oriented to receive pin  52  when card holder  15  in manually guided into the enclosure. 
     When cam lever  62  is urged in a direction to the right relative to FIG. 8, a bottom portion of cam link  92  pivotally connected to cam lever  62  translates to the right while an upper surface defining an upper portion of slotted opening  70  urges pin  52  toward socket  11  and cam link is in a second position shown generally at  96 . As discussed above in detail with previous embodiments, card carrier  16   a  in restricted to vertical translation as a result of fixed pins  74  within slots  72  configured in carrier  16   a  to guide and define vertical motion thereof. 
     Similarly, when cam lever  62  is urged in a left direction relative to FIG. 8 after connector  12  and socket  11  are engaged, cam link  92  is oriented in the first position  94  orienting slot  70  for allowing removal of pin  52  from slot  70  when card holder  15  is removed from the enclosure by translating card holder  15  in the right direction relative to FIG.  8 . When cam lever  62  is urged in a direction to the left relative to FIG. 8, the bottom portion of cam link  92  pivotally connected to cam lever  62  translates to the left while a lower surface defining a lower portion of slotted opening  70  urges a bottom portion of pin  52  away socket  11  and cam link is in the first position  94 . 
     Referring now to FIG. 9, an alternative embodiment of a cam assembly  160  for use with a docking apparatus is illustrated. Cam assembly  160  includes cam lever  62  extending from the enclosure at one end and pivotally connected to cam link  92  at another end. Cam lever  62  is pivotally connected to cam link  92  via a pin  98  and a slot  100  connection. Pin  98  depends from cam lever  62  and is limited to horizontal translation when cam lever  62  is actuated, while slot  100  is configured in an intermediate portion of cam link  92  to retain pin  98 . Cam link  92  in pivotally fixed relative to card holder  15  at one end generally shown at  101  and is in operable communication with carrier  16   a  via a second pin  102  and slot  104  connection. Pin  102  is fixedly secured to carrier  16   a  and is disposed in slot  104  configured at an opposite end of pivotal attachment  101  of cam link  92 . 
     In operation, when cam lever is urged to the right relative to FIG. 9, cam link  92  is in a first position shown generally at  106  via translation of pin  98  to the right urging an upper surface defining slot  100  upward and operably translating card carrier  16   a  upward via pin  102  in slot  104 . As discussed above in detail with previous embodiments, card carrier  16   a  is restricted to vertical translation indicated with arrow  107  as a result of fixed pins  74  within slots  72  configured in carrier  16   a  to guide and define vertical motion thereof. When cam lever  62  is urged to the left as indicated by arrow  108 , cam link  92  is in a second position shown generally at  110  via translation of pin  98  to the left urging a lower surface defining slot  100  downward and operably translating card carrier  16   a  downward via pin  102  in slot  104 . 
     Referring now to FIG. 10, yet another alternative embodiment of a cam assembly  160  for use with a docking apparatus is illustrated. Cam assembly  160  includes cam lever  62  extending from the enclosure at one end and pivotally connected to cam link  92  at another end. Cam lever  62  is pivotally connected to cam link  92  at one end  112  of cam link  92  via a rivet or pin  114 , for example, but not limited thereto. Cam link  92  is pivotally connected to card holder  15  at pin  116  allowing rotation of cam link  62  about pin  116 . Cam link  92  is in operable communication with carrier  16   a  via second pin  102  and slot  104  connection. Pin  102  is fixedly secured to carrier  16   a  and is disposed in slot  104  configured at an opposite end of one end  112 . 
     In operation, when cam lever  62  is urged to the right relative to FIG. 10, cam link  92  is in a first position as illustrated in FIG.  10 . In this position, card connectors  12  of card  13  are not electrically coupled to socket  11 , as pin  102  is biased in direction indicated by arrow  118  urging an upper surface defining slot  104  upward and operably translating card carrier  16   a  upward via pin  102  in slot  104 . As discussed above in detail with previous embodiments, card carrier  16   a  is restricted to vertical translation indicated at  107  as a result of fixed pins  74  within slots  72  configured in carrier  16   a  to guide and define vertical motion thereof. When cam lever  62  is urged to the left relative to FIG. 10, cam link  92  is pivoted in a counterclockwise direction about pin  116  as cam lever  62  urges cam link  92  to the left indicated by arrow  120  via pivotal connection of cam lever  62  with cam link  92  at pin  114 . Counterclockwise rotation about pin  116  causes rotation of pin  102  in a direction indicated by arrow  122  urging a lower surface defining slot  104  downward and operably translating card carrier  16   a  downward via pin  102  in slot  104 . 
     Although the invention has been shown using a PCI long card, the apparatus is adapted to be used with cards of various size and specifically with an alternate size such as the industry standard short card. It should also be noted that the terms “first”, “second”, and “third”, and the like may be used herein to modify elements performing similar and/or analogous functions. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated. 
     While the invention has been described with reference to an exemplary embodiment, 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 disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.