Abstract:
One exemplary docking station has a surface for receiving a portable computer, with a wall and a latch projecting from the receiving surface. The latch is movable towards and away from the wall, is resiliently biased towards the wall, and has an overhang that can engage a striker plate of a portable computer when the latch is moved towards the wall, so that the overhang restrains the striker plate against movement away from the receiving surface. The overhang can release the striker plate when the latch is moved away from the wall. A release actuator operable by a user engages the latch so that operation of the release actuator causes the latch to move away from the wall.

Description:
BACKGROUND 
   Battery powered portable computers, sometimes known as “notebook” or “laptop” computers, are usually designed to be substantially self-contained, so that they can be used wherever they and their user happen to be. However, in some instances a user may wish to attach external devices to the portable computer. For example, the portable computer may be connected to any or all of a CRT monitor, a mouse, a 104-key keyboard, a network adapter, and a power supply. 
   To make it easier to attach and remove these external devices, a “docking station” or “port replicator” may be provided. The external devices and the portable computer can be separately connected to and removed from the docking station. The docking station typically has one or more latches to hold the computer in position, and one or more connectors that, when the computer is latched in place, mate with a corresponding connector in the computer to provide connection paths through the docking station to the external devices. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic cross-section through a first embodiment of a docking station and computer in accordance with one embodiment of the invention. 
       FIG. 2  is a somewhat schematic cut-away perspective view of a docking latch structure in accordance with an embodiment of the invention. 
       FIG. 3  is a view similar to  FIG. 2  showing the docking latch of  FIG. 2  engaged in a portable computer in accordance with an embodiment of the invention. 
       FIG. 4  is an oblique view of a second embodiment of a docking station in accordance with another embodiment of the invention. 
       FIG. 5  is a partly schematic sectional view, partly cut away, showing a docking latch of the docking station shown in  FIG. 4 . 
       FIG. 6  is a top view of part of the docking latch mechanism shown in  FIG. 5 . 
   

   DETAILED DESCRIPTION 
   Referring to the accompanying drawings, and initially to  FIG. 1 , a first embodiment of a docking station  10  according to the invention is designed to receive an embodiment of a portable computer  12  according to the invention. One side  14  of the portable computer, shown as the underside, is placed against a support surface  16  of the docking station  10 . In this description, words such as “upper,” “lower,” “raise,” “on,” and “underside” that imply a specific orientation are used with reference to the orientation shown in  FIGS. 1 and 4  of the drawings. However, it will be understood that the embodiments of docking station shown in the drawings may be used in other orientations. 
   A latch  18  extends through an opening, which in the embodiment is in the form of a slot  20 , in the support surface  16  of the docking station  10 . The latch  18  has a beak  22  projecting sideways. The latch  18  is attached to the docking station  10  by a pivot  24 , and is movable within the slot  20  between a locking position (shown in  FIG. 1 ) in which the beak  22  projects beyond the end of the slot  20  and an unlocking position in which the beak is above the slot  20 . The latch  18  is urged into the locking position by a biasing member, such as spring  26 . 
   The slot  20  is surrounded by a rib  28 . A clearance or space extends between a side of the beak  22  of the latch  18  towards the support surface  16  and a side of the rib  28  away from the support surface. 
   The underside  14  of the portable computer  12  has an opening  30  that is dimensioned to fit round the rib  28 , so that when the underside of the portable computer is positioned on the support surface of the docking station  10 , the rib  28  projects into the opening  30 . On one side of the opening  30  is a striker plate  32  that overhangs the rib  28 . The beak  22  of the latch overhangs the striker plate in the locking position of the latch. 
   The beak  22  of the latch  18  has on its side away from the support surface  16  a cam surface  34 . The cam surface  34  is angled so that, if the portable computer  12  is placed into position on the docking station  10 , the side of the striker plate  32  facing the support surface  16  will engage the cam surface  34  and push the latch  18  into its unlocking position against the action of the spring  24 . This movement of the latch  18  allows the portable computer  12  to be placed on the docking station  10  without the latch  18  having to be manually released. Once the computer  12  is in a docked position, the spring  24  returns the latch  18  to the locking position. The side of the beak  22  facing the support surface  16  and the side of the striker plate  32  away from the support surface  16  are not angled. As a result, the latch  18  cannot be released merely by pulling the computer  12  away from the docking station  10 . 
   In order to release the computer  12  from the docking station  10 , the docking station is provided with a release button  36 . When the release button  36  is pressed, a pushrod  38  deflects the latch  18  into the unlocking position, allowing the computer  12  to be removed from the docking station  10 . The pushrod  38  is not attached to the latch  18  so if the latch is deflected by placing the computer  12  onto the docking station, the pushrod  38  does not move. 
   The pushrod  38  is provided with a key-operated lock  40  that in one position prevents, and in another position permits, using the release button  36  to deflect the latch  18 . Thus, even with the lock  40  locked, a user can place the computer  12  onto the docking station  10 . The latch  18  is deflected by the striker plate  32  engaging the cam surface  34  of the beak  22 . Once the computer  12  is in a docked position, the spring  26  returns the latch  18  to the locking position, with the beak  22  above the striker plate  32 . In order to release the computer  12 , the user must use a key to unlock the lock  40  and permit actuation of the release button  36 . 
   As shown in  FIG. 1 , the key-operated lock  40  may be an external device that when locked both disables the pushrod  38  by blocking an interlock mechanism  42  within the docking station  10  and secures the docking station  10  by a tether  44 . It is thus desirable to keep the lock  40  secured even when the portable computer  12  is not present. With the embodiment of the docking station shown in  FIG. 1 , if the user relocks the lock  40  immediately after removing the computer  12 , then the user does not need to use the key again when returning the computer  12  to the docking station. Thus, a user who leaves the docking station locked when the computer  12  is absent uses the key on fewer occasions than a user who locks the docking station only when the computer  12  is present. By offering a reduction in the use of a key, the embodiment of the portable computer shown in  FIG. 1  encourages the user to relock the lock  40  immediately after removing the computer  12 . The conscientious user who would in any case have relocked the docking station after removing the computer experiences a reduction in inconvenience as compared with an arrangement where the lock  40  must be unlocked and locked manually each time, and there is a corresponding reduction in wear and tear on the lock mechanism itself. 
   The lock  40  does not lock the latch  18 . The lock  40  locks only the pushrod  38 , leaving the latch  18  free to move against the spring  26 . Because the latch  18  is free to move, the computer  12  could be released by pushing the latch  18  back in some other way, for example, by introducing some tool between the support surface  16  of the docking station  10  and the underside  14  of the portable computer. However, the rib  28  obstructs any attempt to push the latch  18  back by inserting such a tool. 
   Displacing the entire portable computer  12  over the support surface  16 , from left to right as seen in  FIG. 1  could disengage the computer from the latch  18 . Engagement of the rib  28  with the periphery of the opening  30  may prevent movement of the computer  12  on the support surface  16 . If the engagement of the rib  28  in the opening  30  is not considered sufficient to prevent movement of the computer  12  on the support surface  16 , other structures may be provided to prevent movement of the computer on the support surface. As an example of such a structure, in  FIG. 1  a peg  46  is shown projecting from the support surface  16  into a hole  48  in the side  14  of the portable computer  12 . 
   Referring now to  FIGS. 2 and 3 , in one embodiment of a docking latch structure, the rib  28  forms a generally rectangular wall round the slot  20 . The wall  50  forming the side of the rib  28  over which the beak  22  of the latch  18  projects is lower than the wall  52  round the other three sides. As shown in  FIG. 2 , the taller wall  52  is flush with, or projects into the interior of the portable computer  12  slightly beyond, the wall forming the side  14  of the portable computer. As shown in  FIG. 3 , the less tall wall  50  fits with a slight clearance under the striker plate  32 . In this embodiment, the side of the striker plate  32  facing towards the support surface  16  is flush with the inner surface of the wall forming the surface  14  of the portable computer  12 . The striker plate  32  may then be a separate piece of material spanning one side of the opening  30 . 
   Referring now to  FIGS. 4 to 6 , a second embodiment of a docking station, indicated generally by the reference number  110 , has a support surface  116  on which the underside of a portable computer is arranged to be placed. Two latches  118 , which may be similar to the latches  18  shown in  FIGS. 2 and 3 , extend through respective slots  120  in the support surface  116  of the docking station  110 . Each latch  118  has a projecting beak  122 . Each latch  118  is attached to the docking station  110  by a pivot  124 , and is movable within the slot  120  between a locking position (shown in  FIG. 5 ) in which the beak  122  projects beyond the end of the slot  120  and an unlocking position in which the beak is above the slot  120 . The latch  118  is urged into the locking position by a biasing member, such as a spring  126 . The pivot  124  and the spring  126  are mounted on framing  150  integral with, or securely attached to, the casing of the docking station  110 . In the interests of clarity, parts of the framing  150  that serve merely to support other components are omitted from  FIG. 5  where they would obscure the view of functional components. 
   The slot  120  is surrounded by a rib  128 , which may be similar to the rib  28  shown in  FIGS. 2 and 3 . Where the beak  122  of the latch  118  overhangs the rib  128 , there is a clearance between them. 
   As shown in  FIG. 4 , the support surface  116  is provided with two upright, cylindrical posts  146  near to the latches  118 , and with two upright abutments  152  at the rear of the support surface  116 . A corresponding portable computer may be provided with a pair of holes similar to the hole  48  shown in  FIG. 1 . The holes and the openings  30  may be positioned relative to each other and to the rear of the case of the personal computer so that when the rear of the computer is centered against the abutments  152  the holes  48  will fit over the posts  146  and the openings  30  will then be correctly aligned with the latches  118 . Centering marks  154  may be provided on the docking station  110  and the computer to assist the user in centering the computer laterally. 
   The docking station is provided with a release button  136  at one side of the docking station  110  that can be pressed down by the user. Referring now also to  FIG. 5 , the release button  136  is connected to a lever  138  extending across the docking station  110  and held up by a spring  156 . At the middle of the width of the docking station  110 , the lever  138  lies over the rear end of a lever  158 , which is held up by a spring  160 . The lever  158  is forked, with arms  162  extending symmetrically to the two latches  118 , and is pivoted about a pair of coaxial pivots  164 , one in each arm, mounted on the framing  150 . This arrangement makes it possible for the arms  162  to deliver equal and symmetrical operating forces and motions to the two latches  118  even though the mechanism is operated by a single release button  136  at one side of the docking station  110 . 
   Referring now also to  FIG. 6 , each arm  162  has a pair of fingers  168  that engage a J-shaped actuator  170 . The actuator  170  has a long arm  172  that is pivoted to the framing  150  at a pivot  174 , a short arm  176  that engages the latch  118 , and a cross member  178  that connects the arms  172  and  176 . The actuator  170  is made from a plastic material that will flex elastically. The actuator  170  is held down by a torsion spring  180  wound around the pivot  174 . In the rest position of the docking station, the actuator  170  lies on the fingers  168  of the lever  158 . 
   The tip of the short arm  176  of the actuator  170  engages in a notch  181  on the latch  118 , below the beak  122  and roughly level with the pivot  124 . 
   A third finger  182  on each arm  162  of the lever  158  extends into an upright cylindrical housing  184  through a slot  186  in one side of the housing. The housing  184  opens out through the support surface  116  of the docking station  110 . The housing  184  contains a cylindrical plunger  188  that is guided, and held captive, by a lug  190  on one side sliding in a longitudinal slot  192  in the housing  184 . In the rest position, as shown in  FIG. 5 , the top of the plunger  188  is approximately flush with the support surface  116 . The plunger  188  is then supported, by the lug  190  resting on the bottom end of the slot  192 , above and spaced from the finger  182 . 
   In order to release the portable computer from the docking station  110 , a user presses down on the release button  136 . This pushes down the lever  138  against the spring  156 . The lever  138  then pushes down the rear end of the lever  158  against the spring  160 , which raises the fingers  168 ,  182 . The fingers  168  of each arm  162  raise the actuator  170 , with the pivot  174  acting as a hinge. The tip  194  of the short arm  176  of the actuator  170  pushes on the upper face of the notch  181 , rocking back the latch  118 . The length of the short arm  176  is set so that, when the latch  118  is fully pushed back into its released position, the tip of the short arm  176  snaps out of the notch  181  and rests against an upright face  196  of the latch  118  above the notch. The latch then remains locked in its released position until the user releases the release button  136 , allowing the release mechanism to return to its rest position under the action of the springs  156 ,  160 , and  180 , lowering the short arm  176  until the tip  194  re-enters the notch  181 , allowing the spring  126  to return the latch  118  to the latched position. 
   As the fingers  182  rise, they raise the plungers  188 , which push the portable computer up, away from the support surface  116 . Because, in the rest position, there is a space between the fingers  182  and the bottoms of the plungers  188 , the fingers  168  can move the actuators  170  and the latches  118  before the plungers  188  start to rise. This sequence of movement allows the latches  118  to release, reducing the risk that the plungers will press the striker plates  32  against the undersides of the beaks  122  and create friction that will prevent the latches releasing. 
   However, when the release button is pressed, either latch  118  may be prevented from moving, for example, because the top of the striker plate  32  is pressing against the underside of the beak  22 , or because the side of the opening  30  presses against the side of the latch  118 . The release mechanism will then move until, and only until, the plungers  188  abut the underside  14  of the computer  12 . In that case, the actuator  170  twists as the fingers  168  raise the actuator, storing up force. An ordinary user, finding that pressing the release button  136  does not eject the portable computer  12  from the docking station  110 , almost automatically shakes the computer slightly, which usually cures the problem, allowing the latches to snap free. 
   The upward movement of the portable computer  12  caused by the plungers  188  detaches an electrical connector  198  on the support surface  116  from a corresponding connector on the underside of the computer. The computer can now be lifted from the posts  146  and detached from the docking station. However, if the release button is released before the computer  12  is removed from the posts  146 , the computer may drop back onto and re-engage with the electrical connector  198 , and even re-engage the latches  118 . To prevent re-engagement, the support surface  116  may be provided with spring-loaded supports  200  that exert a sufficient upward force to prevent the portable computer dropping back onto the connectors. In the embodiment shown in  FIG. 4 , the supports  200  may be EMI (electromagnetic interference) cones, which are metal components with rounded or conical tops that are electrically connected to grounded metal within the docking station  110  and are arranged to contact exposed metal connected to ground within the portable computer. The supports  200  thus establish an electrical connection between the grounds of the computer and the docking station  110  as long as the computer is docked, reducing the exposure of the combined system to EMI. 
   The beak  122  of each latch  118  has on its upper side a cam surface  134 . The cam surface  134 , like the cam surface  34  shown in  FIGS. 2 and 3 , is angled so that, if a portable computer with suitable openings and striker plates, which in the embodiment may be similar to the opening  30  and striker plate  32  shown in  FIG. 1 , is placed into position on the docking station  110 , the undersides of the striker plates  132  will engage the cam surfaces  134  and push the latches  118  into their unlocking positions against the action of the springs  126 . As may be seen from  FIGS. 5 and 6 , movement of the latches  118  into their unlocking positions moves the notches  181  away from the tips  194  of the short arms  176 . There is no structure or mechanism that prevents this movement. This allows the portable computer to be placed on the docking station  110  without the latches  118  having to be manually released. Once the computer is in position, the springs  126  return the latches  118  to the locking position, with the tips  194  of the short arms  176  in the notches  181 . The undersides of the beaks  122  are not angled to form a cam surface, so the latch  118  cannot be released merely by lifting the computer away from the docking station  110 . 
   The docking station  110  is provided with a key-operated lock  140  that in one position prevents, and in another position permits, using the release button  136  to deflect the latches  118 . The lock  140  may slide a block under the lever  138 , preventing the release button  136  from pushing down the lever  138  far enough to operate the release mechanism. However, the lock  140  does not prevent the latches  118  from deflecting. Thus, even with the lock  140  locked, a user can place a suitable computer onto the docking station  110 . In order to release the computer, the user must use the key to unlock the lock  140  and permit the release button  136  to be used. 
   As shown in  FIG. 4 , the key-operated lock  140  may be an internal device. When locked, the lock  140  may disable the lever  138 . The docking station  110  may be substantially permanently attached to a tether  144 . The lock itself may be a standard security lock, from which the key can be removed only when the lock is in the locked position. It is thus desirable to keep the lock  140  secured even when the portable computer is not present, so that the key can be removed. The embodiment of the docking station  110  shown in  FIGS. 4 to 6 , like the embodiment shown in  FIG. 1 , encourages the user to relock the lock  140  and remove the key immediately after removing the computer, because the user then does not need to use the key again when returning the computer to the docking station. 
   Because the lock  140  does not lock the latches  118 , but only the lever  138 , the computer could be released by pushing the latches  118  back in some other way. However, as explained above with reference to  FIGS. 2 and 3 , the ribs  128  obstruct any attempt to push the latches  118  back by inserting a tool between the underside  14  of the portable computer and the support surface  116  of the docking station  110 . In the embodiment shown in  FIG. 4 , any attempt to push the latches  118  with a tool is further hindered because the latches must be moved forward, so any tool must be inserted behind them, and because the latches are to some extent guarded by the posts  146 , the electrical connector  198 , and the EMI cones  200 . In the embodiment shown in  FIG. 4 , any attempt to push the latches  118  forward with a tool is further hindered because the latches  118  move independently, so they must be pushed forward separately but simultaneously in order to release the computer. 
   Although the invention has been described and illustrated with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes, omissions, and additions may be made thereto, without departing from the spirit and scope of the invention as recited in the attached claims. For example, there may be only a single latch, as shown for the latch  18  in  FIG. 1 , or there may be two latches, as shown for the latches  118  in  FIG. 4 . If there are two latches  18 ,  118 , they may be arranged to move parallel to one another, as shown in  FIG. 4 , or towards and away from each other, or in some other orientation. If there are two latches  18 ,  118  they may be operated by a single release button  136 , as shown in  FIGS. 4 to 6 , through a suitable arrangement of pushrods  38 , levers  138 , or other mechanisms, or they may be operated by, for example, two release buttons. 
   The embodiments shown in the drawings have a continuous rib  28  surrounding the opening  20  in the docking station  10 . This arrangement is both effective at preventing tampering with the latch  18  and esthetically pleasing. The wall  50  prevents the direct application of force to push back the latch  18 , and the parts of the wall  52  immediately adjacent to the ends of the wall  50  prevent the insertion of a straight tool from the side between the wall  50  and the latch  18 . The remaining parts of the wall  52  serve to prevent the insertion of more elaborately shaped tools. Depending on the level of security required, a rib  28  surrounding less than the whole circumference of the opening  20  is possible. 
   The embodiments shown in the drawings have a rectangular rib  28  fitting snugly within a rectangular opening  30  in the underside of the computer  12 . This configuration serves to prevent the computer  12  from being slid sideways or rotated relative to the docking station  10 ,  110 . If there are two latches  118  each with its rib  128 , these will combine to prevent rotation. If the computer  12  can be moved relative to the docking station  10 ,  110 , movement may facilitate disengagement of the latch or latches  18 ,  118  without releasing the lock  40 ,  140  and using the release button  36 ,  136 . Additional structures such as the posts  46 ,  146  or the abutment surfaces  152  may be provided to locate and align the computer  12  relative to the docking station  10 ,  110 . The number, shape, and position of such additional structures can be varied to suit any individual combination of a docking station and a computer. These additional structures may comprise guides that are provided to assist in aligning the computer  12  with the docking station  10  so that the computer can be placed over the latches  18 ,  118  and the ribs  28 ,  128 . 
   One function of a docking station  10 ,  110  is to connect the portable computer  12  to various peripheral devices, network adapters, power supplies, and other attachments, which may be installed in the docking station in bays  202  (see  FIG. 4 ) or attached to connectors  204  on the docking station. The bays  202 , connectors  204 , and the like are then connected to the electrical connector  198 , and through the connector  198  to the computer  12 . Such attachments come in a wide variety, and may be chosen to suit the particular computer  12 . 
   Although the docking stations  10  and  110  have been described with reference to an orientation in which the support surface  16  or  116  faces generally upwards, and the surface  14  of the computer  12  in which the openings  30  are formed is the underside, it will be appreciated that the docking station  10  or  110  and/or the portable computer  12  may be in some other orientation. Furthermore, the orientation of the computer  14  when docked is not necessarily the same as its ordinary orientation in use when undocked. Thus, the surface  14  of the computer  12  in which the openings  30  are formed may be the underside when the computer is docked but not in an ordinary orientation of use when the computer is undocked, or may be the underside in an ordinary orientation of use when the computer is undocked but not when the computer is docked, or may be the underside in both conditions or in neither condition. Furthermore, the latches  18  may be in a different part of the docking station and may be arranged to engage some other part of the portable computer  12 .