Abstract:
A latch assembly for releasably securing a closure element with a striker element in a closed position. The latch assembly consists of first and second latch elements mounted to a housing for movement relative to each other and the housing, with the first latch element being movable relative to the housing between a latched position and a release position, and cooperating structure on the release lever for moving the second latch element relative to the housing and, in response thereto, causing the first latch element to move from its latched position to its release position. A guard plate is positioned between the housing and the first latch element to more securely retain the striker element and prevent tampering or theft.

Description:
[0001]    This continuation-in-part application claims priority from U.S. patent application Ser. No. 12/510,796 filed Jul. 28, 2009, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Latch mechanisms having a rotatable latch element for engaging/disengaging a striker element are common, as seen, for example, in U.S. Pat. No. 4,438,964 to Peters and U.S. Pat. No. 5,042,853 to Peters, the contents of each are fully incorporated herein by reference. While effective for latching containers and the like, these latch assemblies suffer from security issues where the locking feature can be defeated by thieves. For example, a single hook shaped retaining member such as that found in the Peters latch assembly can be defeated if the lid/latch bar can be pushed in to bypass the locking cam. This results in an unacceptable security risk where important items are to be stored. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention overcomes the security issue raised above by providing a guard plate that prevents defeat of the locking cam by retaining the striker element in the locking cam when the latch is in the locked closed or locked position. The guard plate can mount to the back of the housing and comprises a surface that mounts flush to the back of the housing, and a horizontal spacing portion directed away from the housing to a position just before or after the hook portion of the locking cam. A shield plate extends vertically from the horizontal spacing portion, the shield portion having a lateral edge that cooperates with the hook portion of the locking cam to form a window enclosure for the striker element. The cooperation of the shield portion and the locking cam retain the striker element therebetween to prevent a thief, sudden impact, or other trauma from dislodging the striker element and defeating the locking mechanism. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is an enlarged, elevated front perspective view of a first embodiment of the present invention; 
           [0005]      FIG. 2  is an enlarged, elevated rear perspective view of the embodiment of the present invention depicted in  FIG. 1 ; 
           [0006]      FIG. 3  is an exploded view of the embodiment of present invention depicted in  FIG. 1 ; 
           [0007]      FIG. 4  is a side view of a second embodiment of the present invention; 
           [0008]      FIG. 5  is a rear view of the embodiment of  FIG. 4 ; 
           [0009]      FIG. 6  is a rear view of the embodiment of  FIG. 4  with the striker rotated; and 
           [0010]      FIG. 7  is a rear view of the embodiment of  FIG. 4  with the striker rotated and the. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0011]      FIGS. 1-3  show a paddle latch assembly  12  for a tool box or the like, embodying the features of the present invention. The paddle latch  12  includes a housing  20  with a rectangular body  21  defining a cup-shaped recess  22  and having a peripheral mounting flange  24  with an enlarged portion  26  and a plurality of mounting holes  27  through the flange  24  for accepting screws, or the like, to fix the latch assembly  12  to the receptacle of a tool box. A rectangular paddle/release member/lever  28  is mounted for rotation within the recess  22  about a hinge pin  30  extending through opposite walls of the body  21 . 
         [0012]    A pair of rotary cams/latch elements  38 ,  40  are pivotably connected at the rear face of the housing  21  by means of a rivet  42  and a spacer washer  43 . The rivet  42  passes successively through the cam/latch element  38 , the cam/latch element  40 , the washer  43 , and opening  45  in the housing  20  and is suitably anchored to the housing  20 . The cam/latch element  38  has a hooked end  44  for engaging a striker bar (not shown) on the tool box lid, and a projecting finger  46 . Rotary cam/latch element  40  includes a depending leg  50  and an upper offset lever arm  54  projecting through an opening  55  in the housing  20 . With the latch mechanism  12  assembled, a shoulder  53  on the leg portion  50  of the rotary cam/latch element  40  abuts a confronting shoulder  56  on the rotary cam/latching element  38 , thereby engaging the cams/latching elements  38 ,  40  to cause the cam/latch element  38  to follow the cam/latch element  40  in an unlatching pivoting direction about the rivet  42  indicated by arrow A, i.e. in a counterclockwise direction. The cam/latch element  38  has a depending tab  57  on which the shoulder  56 . A coil spring  48  is connected between the finger  46  on the cam/latch element  38  and a post  49  projecting from the rear face of the rectangular body  21 , and acts to rotationally bias the cam/latch element  38  and interengaged cam  40  in a clockwise direction (opposite Arrow A). 
         [0013]    A key lock  58  is mounted on the housing  20  and passes through an opening  59  on the enlarged flange portion  26 . The key lock  58  and opening  59  have matched, non-circular cross sections to prevent rotation of the key lock  58  within the opening  59 . The key lock  58  has a grooved lock cylinder  60  with a rotatable locking lever/arm  61  keyed to one end thereof by means of a lock washer  62  and keyway  63  in the locking lever/arm  61 . 
         [0014]    The paddle/release member  28  has a front face  66  defining a graspable handle  68 , a pair of spaced sidewalls  70 , 72  for engaging the hinge pin  30 , and a top wall/flange  76 . The pin  30  guides movement of the paddle/release member  28  between a normal position, shown in  FIG. 1 , and a release position in which the handle is rotated about the pin  30 . In operation, the flange  76  engages the lever arm  54  of the rotary cam/latch element  40  projecting through the opening  55  in the housing  20 . As a rotative force is applied to the handle  68 , the paddle/release member  28  is rotated about the hinge pin  30 , with the flange  76  forcing the lever arm  54  downwardly and thereby rotating the rotary cam  40  about the pivot  42 . Due to the engagement of the shoulders  56 ,  53  on the cams/latch elements  38 ,  40 , rotation of the cam/latch element  40  induced by actuation of the paddle  28  results in rotation of the cam  38  from a latched position, shown in  FIG. 2 , to a release position in which hook end  44  rotates counterclockwise to thereby disengage the hooked end  44  of the cam/latch element  38  from the striker element (not shown) on the tool box lid. The tool box is thereby unsecured and may be opened. 
         [0015]    A restoring force is continuously applied to the cam/latch element  38  by the spring  48 . As the cam/latch element  38  is rotated out of engagement with the striker  18 , the spring  48  is extended and acts to apply a restoring force to the cam/latch element  38 . Once the handle  68  is released to its normal position, the spring  48  acts to rotate the interengaged cams/latch elements  38 , 40  in a clockwise direction in  FIG. 3 . 
         [0016]    The locking lever/arm  61  of the key lock  58  may be rotated by actuation of an external key (not shown) between a locked position wherein the free end  77  of the locking lever/arm  61  confronts the leg  50  of the rotatable cam/latch element  40  and thereby blocks the path of the cam/latch element  40  from its engaged to its disengaged position. When one attempts to actuate the handle  68  of the paddle/release member  20  with the locking lever/arm  61  in its locked position, the flange  76  of the paddle/release member  28  abuts the lever arm  54  of the fixed cam/latch element  40  but cannot displace the lever arm  54  due to the blocking function of the free end  77  of the locking lever/arm  61 , preventing rotation of the paddle/release member  28  about the hinge pin  30 . In order to disengage the hooked end  44  of the cam/latch element  38  from the striker element, it is necessary to rotate the locking lever/arm  61  out of its locked position to thereby allow the paddle/release member  28  to rotate and effectuate rotation of the interengaged cams/latching elements  38 , 40 . 
         [0017]    A guard plate  80  is mounted to the back of the housing for enclosing the striker element with the hook end  44  when the latch is in the locked position. Without the guard plate  80 , the striker element can be displaced from the hook end  44  of the cam  38  by various forces, such as projecting a tool through the opening  55  or by pushing heavily on the housing back and forth. The guard plate  80  has a lower section  85  that attaches to the rear of the housing, such as by welding, adhesive, rivet, fastener, or the like. The lower section  85  may include a projecting arm  90  that extends to the cam  40  and behind the finger  46  of the cam  38 . Extending from the upper edge  92  of the lower section  85  of the guard plate  80  is a spacer section  94  that horizontally offsets the upper portion  96  adjacent the hook end  44  from the lower portion  85  mounted against the housing  20 . The upper portion  96  projects vertically from an end of the spacer section  94 , and includes a vertical edge  98  that extends to the hook end  44  of the cam  38 . The vertical edge  98  cooperates with the hook end  44  to form a window that captures the striker element when the cam  38  is rotated in the position shown in  FIG. 2 . With the guard plate in place, a striker element cannot be dislodged or pried away from the hook member as was the case with the prior art systems. In this manner, the latch assembly is more securely locked to prevent theft and accidental dislodgement of the striker element. 
         [0018]    In a second embodiment of the present invention, as shown in  FIGS. 4-7 , a rotary spring  200  is wound around the rivet  42  and has two legs, a first leg  202  that projects through the window  55  and a second leg  204  that is positioned under a tab  206  on the rotational element  38 . The rotary spring  200  biases the rotational element  38  in a closed position as shown in  FIG. 5 . With the rotatable locking lever/arm  61  in the locked position as shown in  FIGS. 5 and 6 , the rotational member  40   a  cannot rotate clockwise because the end  210  abuts the locking lever/arm  61 . Thus, the paddle cannot release and the latch remains closed. However, unlike the previous embodiment, the latch member can be closed while the lock is in the locked position. That is, in the previous embodiment the latch must be unlocked before the striker pin could enter the latch between the rotational member  38  and guard plate  80 , because the rotational member  40  would not let the rotational member  38  release when the lock was engaged. However, in  FIG. 6 , it can be seen that the rotatable locking lever/arm  61  is engaged, but rotational element  38  may rotate against the bias of the rotary spring  200  to allow a striker pin to enter the window between guard plate  80   a  and the rotational element&#39;s hook member  44 . When a downward force is applied on the surface  230 , as would be the case if a striker pin were to try and engage the locked latch, the force of the pin would cause the rotational element  38  to rotate against the bias of the coiled spring  200  until the pin entered the window formed between the hook portion  44  and the guard plate  80   a.  At this point, the spring would rotate the rotational element back to its home position as shown in  FIG. 5  with the latch pin captured between the rotational element  38  and the guard plate  80   a.  It can only be released, as shown in  FIG. 7 , by disengaging the lock and rotating the rotatable locking lever/arm  61  down so that the lever  210  of the rotational member  40   a  can release as described below. 
         [0019]    When the paddle  28  is raised and the lock  60  is disengaged, the arm  54  of the rotational member  40   a  is driven down, rotating the rotational member  40   a  in the direction shown by the arrow  300  in  FIG. 6 . Rotation of the rotational member  40   a  drives the leg portion  220  clockwise as shown in  FIG. 7 , which in turn pushes the lever  225  of the rotational member  38  in the same clockwise direction. This rotates the hook portion  44  away from the guard plate  80   a  and releases the striker pin (now shown) from the latch. Thus, the rotational element  38  can be rotated either by the paddle  28  through the rotational element  40   a,  or by the force of the locking pin against the surface  230  (against the bias of the rotary spring  200 ).