Abstract:
A cabinet for storing vertically stacked items has a stabilizer. The cabinet has a door and a fixed base, the stabilizer adding to the total support base of the cabinet when extended. If fully extended, the stabilizer prevents tipping if the center of gravity of the cabinet shifts beyond the fixed base. The door automatically engages and extends the stabilizer when the door is initially opened from a closed position. The door continues to engage and extend the stabilizer until the stabilizer is fully extended. Once the stabilizer is fully extended, the door disengages the stabilizer if the door continues to be opened. When closed, the door returns to automatically re-engage and retract the stabilizer. If the stabilizer has been partially retracted during the interval in which the door has been open, the door will still re-engage and retract the stabilizer.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation of U.S. patent application Ser. No. 10/282,887 filed on Oct. 28, 2002 and entitled Expandable Server Cabinet which is incorporated herein by reference. 

   BACKGROUND OF INVENTION 
   Electronic component boxes such as computer servers are frequently stored in cabinets in dedicated locations such as central computer rooms. Electrical component or server cabinets can be used to store component boxes for security and for organizational and aesthetic purposes in these locations. Such locations also tend to be limited in floor space, making it necessary for individual component boxes to be stored vertically in a way that maximizes the usage of space that is available. For these reasons, for example, existing server cabinets are commonly available in a variety of fixed sizes, these cabinets typically being configured to store multiple computer servers In a stacked or vertical arrangement. 
   Many server cabinets are equipped with a front door which allows access to its interior from its front end. Server cabinets are typically equipped with slides on each side that allow each server to temporarily slide out past the front door to allow for quick access to internal components within the servers, without requiring complete removal of a server from its cabinet mounting. The front door typically remains open as each server is serviced. An example of one such server cabinet is described in my co-pending U.S. patent application Ser. No. 10/282,881. 
   Most server cabinets are designed so that the center of gravity of a particular cabinet is supported by the base of the cabinet when the cabinet is either empty or when one or more servers have been installed. However, when the front door is opened and as one or more servers are accessed, each server moves forward on a pair of slides and passes over the front door threshold in a way that may cause the center of gravity of the cabinet to temporarily shift past the fixed base of the cabinet. For this reason, it may be necessary to temporarily expand the support base of a cabinet with an appropriate additional support member while the servers are in a forward position. 
   Due to the limited amount of floor space that is normally available at dedicated locations used for server cabinets, it is often necessary for an external support member to be removable or retractable to normally make available the space that the support member occupies during the servicing of a server while it is in a forward position in a cabinet. However, when a cabinet support member is removable or manually extendable, its use becomes dependent on the initiative of the installer or remover of each server. Therefore, there is a risk that a person servicing a component box, being pressed for time, impatient, or otherwise not inclined to adhere to procedures, could attempt to install or unload a component box without making use of or fully extending the cabinet support member. 
   SUMMARY OF INVENTION 
   The invention is a stabilized cabinet that can store vertically stacked items such as electrical component boxes and a stabilizer therefor. The cabinet has a vertically extending door and a fixed base which is the support base of the cabinet when the door is closed. A stabilizer has a size and is positioned at a location on a cabinet which causes the stabilizer to expand the support base of the cabinet when the stabilizer is extended from the fixed base of the cabinet over floor space that is adjacent the location of the cabinet. If fully extended, the stabilizer leg will sufficiently expand the support base of the cabinet to prevent tipping if the center of gravity of the cabinet shifts beyond the fixed base of the cabinet. 
   The door and the stabilizer are configured to enable the door to automatically engage and extend the stabilizer when the door is initially opened from a closed position, allowing the stabilizer to be extended without requiring someone working with a component box to undertake an additional operational step. 
   As the door continues to be opened, the door continues to engage and extend the stabilizer until the stabilizer is fully extended. Once the stabilizer has been fully extended, the door automatically disengages the stabilizer if the door continues to be opened, allowing the door to swing freely. 
   After the door has been opened, the installer or remover may continue the installation or removal procedure by moving one or more component boxes past the threshold of the door. As this is done, the center of gravity of the combined cabinet and component boxes may temporarily move past the threshold of the door and past the fixed base of the cabinet. However, the center of gravity will remain over the expanded support base created by the extended stabilizer, and the cabinet will be prevented from tipping. 
   The door is also configured to return to the stabilizer and automatically re-engage and retract the stabilizer as the door is closed without requiring additional or manual operational steps to effect retraction. If the stabilizer has been bumped or otherwise partially retracted during the interval in which the door has been open, the configuration of the door and stabilizer will still allow the door to re-engage the stabilizer and will allow the stabilizer to retract. 
   Those skilled in the art will realize that this invention is capable of embodiments which are different from those shown and that details of the structure of the cabinet stabilizer described herein can be changed in various manners without departing from the scope of this invention. Accordingly, the drawings and descriptions are to be regarded as including such equivalent cabinet stabilizers as do not depart from the spirit and scope of this invention. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     For a more complete understanding and appreciation of this invention and many of its advantages, reference will be made to the following detailed description taken in conjunction with the accompanying drawings. 
       FIG. 1A  is a perspective view of a cabinet having a closed front door and a retracted stabilizer according to the invention; 
       FIG. 1B  is perspective view of the cabinet of claim  1 A having an extended stabilizer and an open front door according to the invention; 
       FIG. 2  is a magnified perspective view of the stabilizer of  FIG. 1B ; 
       FIG. 3  is a cross sectional side view of the stabilizer of  FIG. 2 ; 
       FIG. 4A  is a top view of the front end of the cabinet of  FIG. 1A  having a closed front door and retracted stabilizer; 
       FIG. 4B  is a top view of the front end of the cabinet of  FIG. 1A  having a partially opened front door and a partially extended stabilizer; 
       FIG. 4C  is a top view of the front end of the cabinet of  FIG. 1A  having a partially opened front door and a fully extended stabilizer; 
       FIG. 5  is a bottom view of a cabinet, stabilizer and front door according to one embodiment of the invention; 
       FIG. 6A  is a side cross sectional view of the cabinet and stabilizer of  FIG. 5  with the stabilizer being retracted; and 
       FIG. 6B  is a side cross sectional view of the cabinet and stabilizer of  FIG. 5  with the stabilizer being extended. 
   

   DETAILED DESCRIPTION 
   Referring to the drawings, identical reference numerals designate the same or corresponding part throughout the several figures as shown in the drawings. In some drawings, some specific embodiment variations in corresponding parts are denoted with the addition of lower case letters to reference numerals. 
     FIG. 1A  depicts a typical cabinet  50   a  of the invention constructed around a cabinet frame  51   a  that includes a fixed base  56   a , side panels  58 , cover  60  and corner angles  64 . Each of the corner angles extends from a front portion  52   a  to a back portion  54  of the cabinet  50   a . The cover  60  may include ventilation passages  62  that allow air to pass into the interior of the cabinet  50  and which allow for the ventilation of electrical component boxes (not shown) contained therein. 
   A front door  82   a  is vertically mounted on hinges  94  at the front portion  52   a  to extend along the width of the cabinet  50   a . The front door  82   a  includes a doorframe  68  having a top brace  12 , bottom brace  74 , and extruded side rails  70 . A corrugated grille  76  extends between the top brace  72 , bottom brace  74 , and extruded side rails  70  of the front door  50   a  to allow for additional ventilation of the interior of the cabinet  50   a.    
   Normally, electrical component boxes are stored in a vertically stacked fashion within the cabinet  50   a , with center of gravity of the combined component boxes and cabinet  50   a  residing above the fixed base  56   a  of the cabinet frame  51   a . However, most electrical component boxes are serviced while installed in the cabinet  50   a  by moving each component box on its slides over the threshold  63  of the front door  82   a . This typically results in a disproportionate amount of weight being temporarily present at the front portion  52   a  of the cabinet  50   a . This in turn can shift the center of gravity of the combined cabinet  50   a  and component boxes toward the front portion  52   a  of the cabinet  50   a  and possibly off of the fixed base  56   a , reducing the stability of the cabinet  50   a  as each component box is serviced. 
   As best understood with a comparison of  FIGS. 1A and 1B , both the support base and overall stability can be increased with the addition of a stabilizer  116  to the fixed base  56   a  of the cabinet  50   a , the stabilizer  116  being automatically extended, as depicted in  FIG. 1B , when the front door  82   a  Is opened. 
   A magnified view of the stabilizer  116  of  FIGS. 1A and 1B  is depicted in FIG.  2 . The stabilizer  116  includes a pair of reciprocally mounted to fit within the fixed base  56   a  and to be extended from the front portion  52   a  of the cabinet  50   a . A cross member  120  extends across the stabilizer  116  to connect the stabilizer legs  118  and to permit the stabilizer legs  118  to move in unison during extension from or retraction to the fixed base  56   a . Glide legs  122  are positioned at either end of the cross member  120  to support the stabilizer  116  and to allow the stabilizer  116  to slide over floor space adjacent to the front portion  52   a  of the cabinet  50   a  when the front door  82  is opened. 
   The cross member  120  includes a spring loaded pin trap  124  extending along the length of the cross member  120 . A pin track  126  is formed behind the pin trap  124  and against the cross member  120 . The pin track  116  includes exit points  128  at either end of the pin trap  126  that open toward the front of the stabilizer  126 . 
   A cross sectional view of the stabilizer  116  is depicted in  FIG. 3  showing the pin trap  124  biased with a trap spring  130  to an upward position on its pivot  132 . The stabilizer  116  is shown with the front door  82   a  of the cabinet  50   a  positioned over the cross member  120  of the stabilizer  116 . The front door  82   a  has a roller pin  134  that is positioned in a roller pinhole  136  located at a fixed position on the front door  82   a . The roller pin  134  is removable and roller pinholes  136  are included at both the top and bottom of the front door  82   a  to allow for upside hinge reversal of the door. 
   The front door  82   a  is symmetrical along its horizontal centerline, allowing the front door  82   a  to be mounted either to open from the left (as shown in  FIG. 1B ) or from the right (not shown). This symmetry also allows the front door  82   a  and back door  66  to be interchangeable. Roller pinholes  136  are included on both the front door  82   a  and the back door  66  since the front door  82   a  and back door  66  are identical and interchangeable. The roller pin  134  is also shown to be in engagement with the pin track  126  of the cross member  120 . 
     FIG. 4A  is a top view of the front door  82   a  and stabilizer  116  configuration of  FIG. 3  positioned at the front portion  52   a  of the cabinet  50   a , the front door  82   a  being in a closed position and the roller pin  134  being in engagement with the pin track  126 . When the front door  82   a  is initially opened, as shown in  FIG. 4B , the roller pin  134  travels with the front door  82   a  along a pin path  138  while maintaining its engagement with the cross member  120  of the stabilizer  116 . This engagement exerts an extension force against the pin trap  124  and begins to extend the stabilizer  116  from the fixed base  56   a  of the cabinet  50   a . Thus, as the front door  82   a  is opened, the stabilizer  116  progressively begins to extend automatically from the fixed base  56   a.    
   As the roller pin  134  travels along the pin path  138 , it also moves along the pin track  126  toward the exit point  128  at one end of the pin trap  124 . Referring now to  FIG. 4C , the roller pin  134  exits the pin track  126   at  the exit point  128  once the stabilizer  116  is fully extended, automatically disconnecting the front door  82   a  from engagement with the stabilizer  116 . The front door  82   a  can then continue to swing freely and be opened further without further interfering with the stabilizer,  116 . The stabilizer  116  thus acts to extend the support base of the cabinet  50   a  past the threshold  63  of the front door  82   a  and allows for greater stability as electrical component boxes are added to the cabinet  50   a . The inclusion of exit points  128  at either end of the pin trap  126  also allows the pin  134  to exit the pin track  126  regardless of whether the front door  82   a  is mounted to open from the left or from the right. 
   Later, as the front door  82   a  is being closed, the roller pin  134  can re-enter the pin track  126  through the exit point  128 . However, while the front door  82  is in an open position and the cabinet  50   a  is loaded or unloaded, it is possible that the stabilizer  116  could be bumped or otherwise partially retracted by accident so that an exit point  128  of the pin track  126  would be out of line with the pin path  138 . If this were to happen, the roller pin  134  would contact the pin trap  124  as the front door  82   a  rotated toward the front portion  52   a  of the cabinet  50   a . As best understood by comparing  FIG. 2  with  FIG. 3 , the pin trap  124  is tapered so that if the roller pin  134  were to make contact with any portion of the pin trap  124 , the force of the rotating front door  82   a  would cause the roller pin  134  to exert a compression force against the trap spring  130 . This compression force would lower the pin trap  124  on its pivot  132  sufficiently for the roller pin  134  to bypass the pin trap  124  and engage the pin track  126 . 
   Once the roller pin  134  returns to engage the pin track  126 , the force of the rotating front door  82   a  is used to exert retracting forces, exerted through the roller pin  134  against the cross member  120 , to retract the stabilizer  116  into the fixed base  56   a  of the cabinet  50   a . Thus, closing the front door  82   a  automatically retracts the stabilizer  116  into the fixed base  56   a  of the cabinet  50   a  regardless of how far the stabilizer  116  has been extended. Retraction of the stabilizer  116  then frees up adjacent floor space until it is again necessary to open the front door  82   a  to again service electrical component boxes that are stored inside the cabinet  50   a.    
   Although the invention has been shown and described as having a stabilizer having a roller pin and pin trap to effect extension and retraction, it will be appreciated that other stabilizer configurations are also possible and are contemplated to be within the scope of the invention. An example of an alternate configuration is depicted in  FIGS. 5 ,  6 A and  6 B. A stabilizer  150  includes an engagement angle  140  positioned at the end of a stabilizer leg  152 . The stabilizer leg  152  is mounted to extend from or to retract into the fixed base  56   b  of the cabinet  50   b  between leg guides  156 . The front door  82   b  of the cabinet  50   b  includes a springing lever  142  that rests against a stop  144  when the front door  82   b  is in a closed position. The lever  142  is mounted to rotate on a pivot  146  that is in fixed position on the front door  82   b . Movement of the lever  142  is restricted with a biasing spring (not shown) that can be located within the pivot  146 . 
   Referring to  FIG. 5 , the biasing spring does not permit inward rotation of the lever  142  toward the cabinet  50   b  past the engagement position shown with respect to the front door  82   b . The biasing spring does permit limited outward rotation of the lever  142  from the engagement position in a direction that is away from the cabinet  50   b . However, such outward rotation is limited in that the lever  142  is biased to rotate inwardly toward the cabinet  50   b  to the engagement position shown with respect to the front door  82   b . Due to this bias by the biasing spring, the lever  142  is also spring biased to remain in contact with the stop  144  while the front door  82   b  is in the closed position and the lever  142  is in the engagement position. While the front door  82   b  is closed and the lever  142  is in the engagement position, the lever  142  is also proximate the engagement angle  140 . 
   When the front door  82   b  is opened, the lever  142 , remaining in the engagement position with respect to the front door  82   b , contacts and exerts an extension force against the engagement angle  140  to extend the stabilizer  150  and increase the support base of the cabinet  50   b . When the stabilizer  150  is fully extended, the fixed position of the pivot  146  travels with the rotating front door  82   b , moving the lever  142  away from the reach of the engagement angle  140  and preventing further engagement with the stabilizer  150  while keeping the lever  142  in the engagement position with respect to the door  82   b.    
   After the component boxes of the cabinet  50   b  have been serviced, the front door  82   b  can be rotated toward the closed position. If the stabilizer  150  has been bumped or otherwise partially retracted by accident, the lever  142  rotates outward away from the cabinet  50   b  and away from the engagement position against its spring bias to bypass the engagement angle  140  as the lever  142  and engagement angle  140  make contact. 
   Referring to the side cross sectional views of  FIGS. 6A and 6B , the front door  82   b  includes an overhang  148  which is configured to contact the engagement angle  140  and force the stabilizer  150  to retract back into the fixed base  56   b  of the cabinet  50   b  as the front door  82   b  returns to its closed position. The lever  142  clears the engagement angle  140  and returns to its engagement position under the force of its spring bias when the door  82   b  is fully closed. 
   This invention has been described with reference to specific illustrated embodiments. Many modifications and alterations of these embodiments will occur or become apparent to others upon reading and understanding the preceding specification. It is intended and will be appreciated that this invention is to be construed as including all such alterations and modifications insofar as they come within the spirit and scope of the appended claims or equivalents of these claims.