Abstract:
An automatic cage lock for securing various cages in a ventilated cage and rack system. The automatic cage lock facilitates the securing of a cage within the cage and rack system when a user slides the cage into the cage and rack system until the cage fully passes the locking finger component of the automatic cage lock. The cage may be easily unlocked by applying a small amount of pressure to the locking finger while simultaneously grasping the cage for removal. A color-coded indicator block may be disposed on the end of the lock assembly; the indicator block may be hidden by an indicator shield when the cage is securely docked in the rack. Conversely, the indicator block may be visually exposed when a cage is present in the rack but not fully docked within the rack. The indicator block provides a clear indication to a user as to the docking status of the cage.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application Ser. No. 60/348,846, entitled Automatic Cage Lock, filed on Oct. 19, 2001, the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an improved cage lock for securing a laboratory animal cage in a cage and rack system and, in particular, to a cage lock which releasably secures cages within a cage and rack system. 
     2. Description of Related Art 
     Cage and rack systems used to store laboratory animals are well known in the art. Typically, such systems include a plurality of shelves, each shelf containing a plurality of cages which provide air and/or water to the animals stored therein. The cages are generally removable from the rack to provide access to the laboratory animals for feeding and testing, and to provide access to the cages for cleaning, maintenance and transport. To accommodate these requirements, rack systems are typically designed so that the cages can slide in and out of the rack system. When a laboratory animal is housed and maintained in the cage, the cage may be secured in place in the rack with a cage lock to prevent the cage from inadvertently sliding out from the rack. One concern of not securing a cage in the rack is that a sliding cage can cause suffocation of the laboratory animal within the cage by a disruption in air supply, dehydration of the laboratory animal by a disruption of water to the cage drinking valve or injury or death to an animal from the impact of the cage falling from the rack. One such system is disclosed in U.S. Pat. No. 5,954,015, the contents of which is incorporated herein be reference. 
     While related cage locks work for their intended purposes, a deficiency of related cage locks is that the lock has to be grasped in order to switch it between the locked and unlocked positions when inserting a cage. Another deficiency of related locks is that changing the position of the lock to accommodate a different cage size is cumbersome because it requires an operator to pull a retaining member away from a base member while at the same time rotating the retaining member 180 degrees. These cage locks typically require a user to make use of the back of his or her hand to disengage the cage lock. Yet another deficiency with known locks is that it can be difficult to determine whether the locking mechanism is in the locked or unlocked position without carefully observing the state of the locking mechanism. Additionally, related cage locks are typically relatively large, thus obstructing a user&#39;s view to the cage interior. Related cage locks also typically contain a relatively large amount of components, such as springs, hinges and fasteners. This relative mechanical complexity leads to corresponding manufacturing and maintenance costs. Further more, related cage locks, due to the nature of their mechanical design, typically facilitate the marring of cage side walls. As such, a need exists for an improved cage locking mechanism and system. 
     SUMMARY OF THE INVENTION 
     The present invention satisfies this need. The present invention is directed to a cage lock for securing cages in a ventilated cage and rack system that facilitates locking and unlocking of the cage. 
     The present invention is directed to an automatic cage lock that secures an animal cage within a cage and rack system with minimal effort by, or inconvenience to, its user by providing hands free locking while installing the cage into the cage and rack system while also providing easy removal of the cage with the slight use of a single finger while simultaneously grasping the cage with both hands. 
     The automatic cage lock may comprise a flexing lock member for securing the cage in the cage and rack system having a member deflector to automatically deflect the flexing lock member away from the cage during insertion of the cage into the cage and rack system. Once the cage is fully inserted into the rack, the flexing lock member resiliently returns to the locked position. This flexing away during insertion of the cage and return to the locking position once the cage is fully inserted may relieve the user of the need for awkward hand maneuvers during insertion and locking of the cage. Furthermore, the use of a flexing lock member may eliminate the need for any relatively complex mechanical structures such as hinges, springs or fasteners. 
     An embodiment of the invention may provide for a visual indicator so that a user can easily visually determine whether or not a particular cage is in a locked condition. 
     An embodiment of the invention may comprise a mounting bracket comprised of a base and a support arm. The support arm may include a docking channel which allows a lock assembly to be slidably mounted to the support arm. The support arm may be configured to be mated to the lock assembly to reduce sliding between the support arm and the lock assembly. A fastening member may be disposed through the support arm to securely lock the support arm and the lock assembly together subsequent to adjusting the length of the automatic cage lock. 
     Other objects and features of the present invention will become apparent from the following detailed description, considered in conjunction with the accompanying drawing figures. It is to be understood, however, that the drawings are designed solely for the purpose of illustration and not as a definition of the limits of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawing figures, which are merely illustrative, and wherein like reference numerals depict like elements throughout the several views: 
         FIG. 1  is a perspective view of an automatic cage lock constructed in accordance with the present invention; 
         FIG. 2  is a perspective view of a lock assembly of an automatic cage lock constructed in accordance with the present invention; 
         FIG. 3  is a perspective view of a mounting bracket of an automatic cage lock constructed in accordance with the present invention; 
         FIG. 4  is a perspective view of a mounting bracket of an automatic cage lock constructed in accordance with the present invention; 
         FIG. 5  is a perspective view of an automatic cage lock constructed in accordance with the present invention; 
         FIG. 6  is a front elevational view of a cage and rack system having an automatic cage lock constructed in accordance with the present invention; 
         FIG. 7  is a perspective view of a cage and rack system having an automatic cage lock constructed in accordance with the present invention; 
         FIG. 8  is a perspective view of a user deflecting a member deflector away from a cage in accordance with the present invention; and 
         FIG. 9  is a perspective view of a cage lock and cage in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The present invention is directed to an automatic cage lock that secures an animal cage within a cage and rack system with minimal effort by, or inconvenience to, its user by providing hands free locking while installing the cage into the cage and rack system while also providing easy removal of the cage with the use of, for example, a slight left movement of the thumb on a user&#39;s left hand to disengage the lock while simultaneously grasping the cage with both hands. Additionally, a visual indication of whether the cage is in the locked position is also provided. 
     Referring now to the drawings in detail,  FIG. 1  depicts an embodiment of an automatic cage lock  10  constructed in accordance with the present invention. The automatic cage lock  10  is comprised of a mounting bracket  14  and a lock assembly  30 . In an exemplary embodiment, the automatic cage lock  10  is molded of an autoclaveable material, however, the automatic cage lock  10  may also be manufactured in stainless steel or by an application of material design well known to one skilled in the art. The mounting bracket  14  is comprised of a base  16  and a support arm  20  which may be unitarily formed. The support arm  20  extends generally outwardly and away from the base  16  and is generally perpendicular thereto. The base  16  of the mounting bracket  14  is generally flat which allows the mounting bracket  14  to be mounted to a variety of surfaces. The support arm  20  of mounting bracket  14  has at least one docking tab  22  which is formed in parallel with support arm  20 . Docking tab  22  has a generally angular surface which forms a docking channel  18  therein. The docking channel  18  allows the lock assembly  30  to be slidably mounted to the support arm  20 . The slideable mounting feature of automatic cage lock  10  allows the adjustment of the lock assembly  30  within the mounting bracket  14  to adjust the longitudinal length of the automatic cage lock  10  to fit various sized cages and configurations. 
     The lock assembly  30  includes at least one mounting rail  32 . The mounting rail is generally angular shaped to provide slideable mounting to support arm  20 . The lock assembly has a locking aperture  56  formed therein. The locking aperture  56  may be generally circular (although other shapes may be used as a matter of application specific design choice by one skilled in the art) and provides a means for fixably securing the lock assembly  30  to the mounting bracket  14 . A plurality of engagement teeth  60  may be formed adjacent to locking aperture  56  to provide a secure mating between lock assembly  30  and mounting bracket  14  and to prevent sliding therebetween. A flexing lock member  42  and a visual indicator arm  52  may be unitarily formed in a generally U-shaped configuration. The U-shaped configuration of flexing lock member  42  and visual indicator arm  52  forms a separation channel  34  therebetween. The separation channel  34  allows flexing lock member  42  to move independently of visual indicator arm  52 . 
     A locking finger  50  is disposed at the end of the flexing lock member  42 . The locking finger  50  has a locking plate  54  and a locking tab  44  formed thereon. The locking plate  54  is generally flat and is disposed on the locking finger in a configuration that is generally perpendicular to flexing lock member  42 . The locking plate  54 , due to its shape, which in an embodiment of the invention is flat and plate-like, prevents the cage from falling out of the cage and rack system after the cage is securely docked therein. The locking tab  44 , which protrudes from the end of the locking finger  50 , provides a secure means of securing the cage within the cage and rack system by engaging about the edge of the cage whereby preventing the locking finger  50  from becoming disengaged. The locking finger  50  has a member deflector  40  formed thereon which is generally flat and angular. The member deflector  40 , due to its shape, facilitates deflection of the flexing lock member  42  and the locking finger  50  out of the path of the cage as it is being inserted into the cage and rack system. The smooth angular shape of member deflector  40  also serves to minimize scratching from occurring to the side of the cage. 
     In an embodiment of the invention, portions of one, all, or some combination of member deflector  40 , end block  46  and locking tab  44  may be formed of a lightweight, durable low wear, low friction plastic such as, for example, the material sold by E.I. Du Pont De Nemours and Co. under the trade name DELRIN®. Use of such a material in accordance with the invention tends to minimize squeaking sounds when a cage rubs against either deflector  40 , end block  46  or locking tab  44 . 
     After the cage is fully inserted into the cage and rack system, the flexing lock member  42  springs back into its original position to securely lock the cage into place. 
     The visual indicator arm  52  may have an indicator block  36  inserted therein. The indicator block  36  may be color-coded (e.g., yellow) and is used to visually indicate whether a cage is securely docked in the cage and rack system or is at risk of falling out. The color-coded indicator block  36  provides a quick visual check which the user may conveniently employ to see whether the cage is securely docked in the cage and rack system. A securely docked cage is profoundly important to the health and well-being of the animal or animals contained therein. For example, a cage that is not properly docked may lack the proper ventilation or access to a water supply that is required for the survival of the animal. Typically, cage and rack systems have ventilation systems and water supply systems that are only accessible to the rear of the cage when it is fully docked in the cage and rack system. Therefore, an improperly docked cage could compromise the animal contained therein. 
     The flexing lock member  42  containing the locking finger  50  has an end block  46 , that may be unitarily formed with an indicator shield  38 . The end block  46  and the indicator shield  38  may be unitarily formed and adjacent to the locking finger  50 . The end block  46  and indicator shield  38  are disposed generally parallel to the locking plate  54  and protrude outwardly from the locking finger  50  so as to cover the indicator block  36  when the flexing lock member  42  is in its original, or locked position. As the cage is being inserted into the cage and rack system, the member deflector moves the locking finger  50  away from the path of the cage. As the locking finger  50  is deflected away from the cage, the end block  46  and indicator shield  38  are deflected away as well. As the indicator shield  38  is deflected away from the cage, the indicator block  36  is exposed, thus providing a quick visual indication that the cage is not securely docked within the cage and rack system. 
     In an embodiment of the invention, lock assembly  30  may have a length L of from about 2 to 3 and preferably 2.5 inches. In an embodiment of the invention, lock assembly  30  may have a width W from about 0.25 to 0.75, preferably 0.5 inches. The relatively small footprint of lock assembly  30  facilitates easy viewing of a cage without the viewing being obscured by the lock assembly. Of course, other dimensions may be used in accordance with the invention as a matter of application specific design choice. 
     Referring now to  FIG. 2  with continued reference to  FIG. 1 , the lock assembly  30  is shown as constructed in accordance with an embodiment of the present invention.  FIG. 2  illustrates an indicator housing  48  formed at the end of the visual indicator arm  52 . The indicator housing  48  is formed to accept the indicator block  36  depicted previously in FIG.  1 . The indicator housing  48  allows a variety of color-coded indicator blocks  36  to be inserted therein. The color-coded indicator blocks  36  may be used to indicate a variety of statuses. For example, different colors may be used to indicate different animals or, for example, different groupings of animals with respect to a study or experiment.  FIG. 2  further illustrates an end stop  58  formed at the end of the U-shaped configuration of flexing lock member  42  and visual indicator arm  52 . Further referring to  FIG. 2  with continued reference to  FIG. 1  illustrates that the end stop  58  prevents the lock assembly  30  from advancing past a fixed point by end stop  58  coming into contact with the base  16 . 
     Referring now to  FIG. 3 , the mounting bracket  14  will be discussed in further detail with continued reference to FIG.  1 . The mounting bracket  14  is shown having a mounting aperture  24 . The mounting aperture  24  may be generally circular and, in an embodiment, the mounting aperture  24  is used to mount the mounting bracket  14  to a fixed surface using a fastening device such as, for example, a screw. The mounting bracket  14  may be comprised of the base  16  and the support arm  20 . The support arm  20  may have an adjusting aperture  28  formed therein. The adjusting aperture  28  is generally elongated which allows for a fastening device to be inserted therethrough. Referring again to  FIG. 3  with continued reference to  FIGS. 1 and 2 , the support arm  20  has a plurality of ratchet teeth  26 , which are used to matingly engage the engagement teeth  60  contained on lock assembly  30 . The ratchet teeth  26  and the engagement teeth  60  prevent the lock assembly  30  from sliding along the docking channel  18  when it is engaged therein, thus maintaining the lock  10  at a specific adjusted position when cages are being pushed into position. The support arm  20  is depicted as having two docking tabs  22  which form a docking channel  18  therebetween. The docking tab  22  has a rail guide  12  which is generally angularly shaped to slidably accept the mounting rail  32  of lock assembly  30 . The angular shape of rail guide  12  serves to minimize the occurrence of mounting rail  32  of lock assembly  30  slipping out of, or being disengaged from, the docking channel  18 . The angular shape of rail guide  12  serves to minimize the occurrence of the mounting rail  32  slipping out of docking channel  18  while also providing slideable moveability along docking channel  18 . This facilitates a longitudinal adjustment of lock assembly  30  to fit customized cages and sizes within the cage and rack system. 
     Now referring to  FIG. 4  with continued reference to  FIG. 3 , a perspective view of mounting bracket  14  is illustrated depicting a mounting aperture  24 . In an embodiment of the invention, a plurality of mounting apertures  24  are employed, thus allowing the mounting bracket  14  to be securely mounted to a surface using a type of fastening device such as a screw(s). In another embodiment, one of the mounting apertures  24  may be replaced with a solid peg. The solid peg is inserted into a pre-drilled hole in the cage and rack system and the second mounting aperture  24  secures mounting bracket  14  to the cage and rack system using a fastening device such as, for example, a screw or a bolt. This embodiment including the peg provides for a fixed and quick mounting of the mounting bracket  14 . 
     Referring now to  FIG. 5  with continued reference to  FIG. 1 , an automatic cage lock  10  is shown having a fastening member  62  which is inserted in adjusting aperture  28 . The fastening member  62  may be used to provide a fixed and secure connection between the mounting bracket  14  and the lock assembly  30 . The fastening member  62  may be loosened to slidably adjust the longitudinal size of automatic cage lock  10  to fit custom cage sizes. The fastening member  62  may then be tightened to provide a secure connection by compressing the engagement teeth  26  after the automatic cage lock  10  has been adjusted to the desired longitudinal size. 
     Referring now to  FIG. 6 , a cage and rack system  70  is depicted having a plurality of cage bins  72  contained therein. The automatic cage lock  10  is shown installed on the cage and rack system  70 , and the automatic cage lock  10  is depicted securing a cage  66  within the cage bin  72 . 
     In  FIG. 7 , with continued reference to  FIG. 6 , the automatic cage lock  10  is fixably mounted to cage and rack system  70  and is further shown securely holding cage  66  in a docked position within the cage and rack system  70 . 
     With reference to  FIG. 8 , a user uses his thumb  100  to easily move the member deflector  40  in direction a, thus revealing indicator block  36 , and providing clearance for the removal of cage  90 . As can be seen from  FIG. 8 , member deflector  40  would also be deflected in direction A during insertion of cage  90 . 
     With reference to  FIG. 9 , there is shown a cage  90  being secured by automatic cage lock  10  as described above. 
     It will thus be seen that the objects set forth above, and those made apparent from the preceding description, are efficiently attained and, because certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.