Abstract:
A lever system deploys a pinion gear that engages a pinion gear receiving portion. A handle is attached to the pinion gear to rotate the pinion gear between a retain position and a release position. The pinion gear receiving portion is attached to a first object and the pinion gear is pivotably mounted to a second object that may be moved with respect to the first object. The design of the pinion gear receiving portion and the pinion gear ensure linear travel of the second object as the pinion gear is rotated between the retain position and the release position. Additionally, the pinion gear and the receiving portion include contours that prevent relative linear motion in all directions.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to a lever system for moving one object with respect to another, and particularly to a lever system that utilizes a rack gear and a pinion gear that are particularly amenable to facilitating the plugging and unplugging of components having multipin connectors.  
         BACKGROUND OF THE INVENTION  
         [0002]    A variety of lever systems have long been used to provide mechanical advantage in moving a given object. The mechanical advantage permits a user to perform tasks that would otherwise be difficult. Depending on the design of the lever system, it may be integrated with or separate from the object being moved.  
           [0003]    In certain applications, it is desirable to have a lever system that provides a very controlled movement of one object with respect to another object. For example, in the assembly or disassembly of certain electrical components in systems, such as personal computers, servers, etc., it is helpful to gain mechanical advantage in plugging and unplugging components while providing a very controlled movement of the objects or components with respect to one another.  
           [0004]    Commonly, printed circuit boards or other components utilize one or more multipin plugs that facilitate an electrical and mechanical connection with, for example, a motherboard or backplane. Gaining mechanical advantage in plugging and unplugging such components has become more important as the pin count in multipin connectors has increased, thus requiring greater force to plug or unplug the connectors. Similarly, it has become increasingly important to provide linear travel of one object with respect to another as the multipin connectors are plugged and unplugged, thereby avoiding damage to the connector. Also, it is often helpful to limit the movement of one object with respect to another object after the connection is completed. The secure connection prevents fatigue or other damage that may affect the connection.  
           [0005]    It would be advantageous to have a lever system that provided substantial mechanical advantage while maintaining controlled movement of one object with respect to another. It also would be advantageous to achieve restricted relative movement of the objects upon completion of connection of the objects or other desired result.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention features a lever system for moving a first object with respect to a second object. The lever system comprises a pinion gear pivotably mounted to the first object for pivotable motion about a pivot axis. A handle is connected to the pinion gear for movement between a release position and a retain position. Additionally, a pinion gear reception portion is mounted on the second object. The reception portion has a rack gear and a guide surface generally opposite the rack gear. The guide surface is positioned to maintain the pinion gear in engagement with the rack gear as the handle is moved from the release position to the retain position.  
           [0007]    According to another aspect of the present invention, a lever system is provided for moving a first object with respect to a second object. The system includes a gear member mounted to the first object and a gear member reception portion mounted to the second object. When the gear member and the reception portion are engaged and rotated with respect to each other, the gear member is moved to a retained position. The design of the gear member and the reception portion prevent relative linear movement in all directions when the gear member is in the retained position.  
           [0008]    According to another aspect of the present invention, a lever system is provided that includes a first object and a second object moveable with respect to the first object. A combined pinion gear and handle are pivotably mounted to the first object for pivotable motion about a pivot axis. The pinion gear and handle may be moved between a release position and a retain position. The pinion gear is engageable with a pinion gear reception portion that is mounted on the second object. The reception portion includes a rack gear and a guide surface generally opposite the rack gear. The guide surface is located to maintain the pinion gear in engagement with the rack gear as the handle is moved from the release position to the retain position. The pinion gear and the reception portion may be designed to prevent any lateral movement along the pivot axis once engaged. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:  
         [0010]    [0010]FIG. 1 is a perspective view of an overall system utilizing one embodiment of a lever system, according to an exemplary embodiment of the present invention;  
         [0011]    [0011]FIG. 2 is a perspective view of an individual lever system connected to two objects that are movable with respect to one another;  
         [0012]    [0012]FIG. 3 is a side view of the lever system illustrated in FIG. 2 showing the handle in a release position;  
         [0013]    [0013]FIG. 4 is an enlarged view of a latch mechanism of the lever system illustrated in FIG. 3;  
         [0014]    [0014]FIG. 5 is a side view of the lever system illustrated in FIG. 3 with the handle in a retain position;  
         [0015]    [0015]FIG. 6 is a side view of the latch mechanism illustrated in FIG. 4 but showing release of the handle;  
         [0016]    [0016]FIG. 7 is a perspective view of the pinion gear engaged with the rack gear;  
         [0017]    [0017]FIG. 8 is a perspective view of the pinion gear receiving portion;  
         [0018]    [0018]FIG. 9 is a cross-sectional view taken generally along line  9 - 9  of FIG. 5;  
         [0019]    [0019]FIG. 10 is a perspective view of the lever system illustrated in FIG. 2 with the addition of a release prevention mechanism; and  
         [0020]    [0020]FIG. 11 is a perspective view similar to FIG. 10 showing the release prevention mechanism in a hold or locked position. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Referring generally to FIG. 1, a system  400  of objects that may be moved relative to one another is illustrated. One or more first objects  402  are moveable relative to a second object  404 . In the particular embodiment illustrated, first object or objects  402  each comprise a module that may be electrically and mechanically engaged and disengaged from the second object  404  which is a cabinet or chassis. In a variety of computer/electrical systems, such as personal computers, serves, etc. some form of the illustrated objects exists.  
         [0022]    For example, a variety of computer or server related systems can be configured to permit the use of pluggable components, i.e. first objects  402 , that may be connected to, for example, a motherboard or backplane of second object  404  across a plug connector  406 . (See FIG. 2). A typical connector  406  includes a multipin plug portion  408  connected as part of second object  404  and a corresponding plug portion  410  connected as part of first object  402 . Plug portions  408  and  410  typically are electrically and mechanically interconnected via a plurality of pins  412 . Generally, a greater number of pins in the multipin connector, requires greater force to engage or disengage plug portions  408  and  410 . Hence, a lever system  414  is used to facilitate movement of each first object  402  with respect to second object  404  which, in the illustrated example, permits the plugging and unplugging of connector  406 .  
         [0023]    Referring generally to FIGS. 3 through 6, an exemplary, preferred embodiment of lever system  414  is illustrated. Lever system  414  includes a pinion gear  416  pivotably mounted to first object  402  for pivotable motion about a pivot axis  418 . Pinion gear  416  is designed to engage a pinion gear reception portion  420  mounted to second object  404 . Reception portion  420  includes a slot  426  into which pinion gear  416  may be rotated.  
         [0024]    If second object  404  is a cabinet or chassis as illustrated in FIG. 1, reception portion  420  can be mounted to an interior wall  422  illustrated in cut-away form in FIG. 3. Pinion gear reception portion  420  potentially is mounted to second object  404  in a variety of ways. For example, reception portion  420  may be molded as a unitary piece with the second object. Other methods include adhesives, fasteners, or a plurality of pins  424  that may be interference fit or heat sealed in corresponding openings in second object  404 .  
         [0025]    A handle or lever  428  is connected to pinion gear  416 . An exemplary embodiment of handle  428  utilizes a stem  430  and a gripping portion  432  disposed at an opposite end of stem  430  from pinion gear  416 . Handle  420  preferably also includes a notch  434  and a spring member  436 , as best illustrated in FIG. 3.  
         [0026]    Pinion gear  416  may be engaged with pinion gear reception portion  420  and, along with handle  428 , rotated between an open or release position, as illustrated in FIG. 3, and a closed or retain position, as illustrated in FIG. 5. In the release position, first object  402  may readily be separated from second object  404 . In the particular example illustrated, plug portion  408  and corresponding plug portion  410  are separated. If, however, it is desired to move first object  402  into engagement with second object  404 , pinion gear  416  is moved into engagement with pinion gear reception portion  420 , and handle  428  is pivoted in the direction of arrow  438  to the retain position, as shown in FIG. 5. As handle  428  is moved to the retain position, first object  402  is moved in a precise, linear fashion into engagement with second object  404 . In the exemplary embodiment shown, corresponding plug portion  410  is moved linearly into engagement with plug portion  408 .  
         [0027]    A latch mechanism  440  preferably is used to retain handle  428  and pinion gear  416  in the retain position. As illustrated best in FIG. 4, latch mechanism  440  includes a base  442  that may be connected to first object  402 . A spring member  444  is connected to base  442  and serves to bias a catch  446  away from base  442 . Additionally, a handle or finger grip  448  is disposed on a distal end of spring member  444 .  
         [0028]    As handle  428  is rotated from the release position (FIG. 3) to the closed position (FIG. 5), gripping portion  432  flexes spring member  444  towards base  442 . Simultaneously, spring member  436  is moved against an interference surface  450  that is typically located on first object  402 . Upon movement of the handle  428  to the fully closed or retain position, catch  446  snaps into notch  434  and maintains handle  428  and pinion gear  416  in the retain position.  
         [0029]    To release handle  428 , latch mechanism  440  is moved out of interference with notch  434  by pressing against finger grip  448  to flex spring member  444  towards base  442 . (See FIG. 6). When catch  446  is disengaged from notch  434 , spring member  436  begins to move handle  428  away from the retain position. This allows an operator to grab gripping portion  432  or stem  430  to pivot handle  428  and pinion gear  416  to a release position. As pinion gear  416  is rotated to the release position, it moves first object  402  in a linear fashion with respect to second object  404  to disengage connector  406  or to serve other desired ends.  
         [0030]    The configuration and operation of pinion gear  416  and pinion gear reception portion  420  can be better understood with additional reference to FIGS. 7, 8 and  9  Pinion gear reception portion  420  includes a base structure  452  having an outer surface  454  and an inner mounting surface or region  456  disposed generally opposite outer surface  454 . Mounting region  456  generally abuts against or is integrally formed with second object  404 .  
         [0031]    Slot  426  is formed in base structure  452  and is defined by an interior surface  458 . Interior surface  458  includes a rack gear region  460  having at least one and preferably two teeth  462  that form a rack gear. Interior surface  458  also includes a distal surface  464  that generally extends between rack gear region  460  and a guide surface  466  disposed generally opposite rack gear region  460 . Distal surface  464  generally defines the deepest region of slot  426  relative to its open end. Preferably, interior surface  452  also includes a beveled lead-in region  468  adjacent guide surface  466  at the open end of slot  426 .  
         [0032]    Pinion gear  416  includes at least one and preferably a pair of teeth  470  designed to engage teeth  462  of rack gear region  460 . As first object  402  and pinion gear  416  are moved into engagement with pinion gear reception portion  420  and second object  404  (see FIG. 3), teeth  470  are positioned for engagement with teeth  462  of rack gear  460 . Then, as handle  428  is pivoted to the retain position (see FIG. 5), teeth  470  of pinion gear  416  drive first object  402  in a linear fashion along linear rack gear region  460  until pinion gear  416  and handle  428  are in the retain position. At this position, the engagement of teeth  470  and teeth  462  prevent any linear motion of pinion gear  416  or first object  402  relative to second object  404  along rack gear region  460 , i.e. along the x-axis, as illustrated in FIG. 7. Additionally, pinion gear  416  includes a distal region  472  that abuts against distal surface  464  of reception portion  420  when pinion gear  416  is in the retain position. This abutting engagement further prevents any movement in the x direction. Pinion gear  416  also includes a stop surface  474  disposed generally opposite teeth  470  for abutting engagement with guide surface  466  of reception portion  420  when pinion gear  416  is in the retain position. The guide surface  466  cooperates with rack gear region  460  to prevent any relative linear motion of pinion gear  416  or first object  402  in a direction perpendicular to rack gear region  460 , i.e. along the y-axis, as illustrated in FIG. 7.  
         [0033]    Preferably, lever system  414  also includes a lateral interference region  476 . This region is designed to prevent lateral movement of pinion gear  416  with respect to reception portion  420  along pivot axis  418 , i.e. along the z-axis as illustrated in FIG. 7. A preferred lateral interference region includes a sloped or angled region  478  disposed along interior surface  458  of pinion gear reception portion  420 . A corresponding sloped or angled region  480  is formed along an outer surface  482  of pinion gear  416 . (See FIG. 9). The lateral interference region  476  may be formed generally at distal region  472  of pinion gear  416  and along distal surface  464  of reception portion  420 . It should be noted, however, that the interference region can be formed at different points or in different forms to prevent lateral movement along the z-axis direction.  
         [0034]    The unique combination of interfering teeth and surfaces between pinion gear  416  and pinion gear reception portion  420  prevents any linear motion of pinion gear  416  relative to reception portion  420  once pinion gear  416  and handle  428  are in the retain position. This ensures a secure and stable interlocking of first object  402  and second object  404 . The secure interlock is particularly beneficial when using the lever system to secure pluggable components having multipin connectors.  
         [0035]    As illustrated in FIG. 9, pinion gear  416  also preferably includes a pivot opening  484  to permit pivotable motion of pinion gear  416  and handle  428  about a pivot pin  486 . The illustrated pivot pin  486  is a screw threaded into first object  402 . However, a variety of pivot pins including injection molded pins, can be used in forming a point of pivotable motion.  
         [0036]    Referring generally to FIGS. 10 and 11, lever system  414  also may include a release prevention mechanism  488  that prevents the inadvertent release of handle  428  from latch mechanism  440 . An exemplary embodiment of security mechanism  488  includes a shaft  490  having a head  492  at one end and a cog  494  at an opposite end. Typically, shaft  490  is rotatably mounted in either first object  402  or second object  404  such that cog  494  is positioned adjacent the side of latch mechanism  440 , as illustrated best in FIG. 10. In this embodiment, latch mechanism  440  includes a flexible tab  496  that moves generally transversely to the movement of spring member  444  and catch  446 . Flexible tab  496  is sized to fit behind catch  446  when catch  446  is engaged with notch  434  of handle  428 .  
         [0037]    Cog  494  includes an extended portion  498  positioned to force flexible tab  496  into the space behind catch  446 , as illustrated best in FIG. 11. Thus, by rotating head  492  in a generally clockwise direction (after handle  428  and latch mechanism  440  are in the retain position), the flexible tab  496  is moved into a position to block movement of finger grip  448  and release of handle  428 . To release handle  428 , extended portion  498  must be rotated away from flexible tab  496 , such that flexible tab  496  springs back from its interfering position with catch  446 . Then, finger grip  448  and catch  446  may be moved to permit release of handle  428 .  
         [0038]    It will be understood that the foregoing description is of a preferred embodiment of this invention, and that the invention is not limited to the specific forms shown. For example, a variety of handle, pinion gear and pinion gear reception portions can be formed to accommodate specific applications. The materials utilized to form the lever system may vary, and the objects to be moved relative to one another will depend on the specific application. These and other modifications may be made in the design and arrangement of the elements without departing from the scope of the invention as expressed in the appended claims.