Latch assembly

Abstract

A latch assembly includes a buckle and a tongue for releasably engaging the buckle. The tongue has a cut-out. The buckle includes a base having a slot for receiving the tongue. The buckle also includes a locking pawl pivotally attached to the base and engageable by the tongue, to pivot the locking pawl so that the locking pawl engages in the cutout of the tongue when the tongue is inserted in the slot of the base. The buckle also includes a release lever pivotally attached to the base, the release lever having a cut-out receiving the locking pawl to engage the release lever when the tongue is inserted in the slot of the base, thereby to block removal of the tongue from the buckle.

1 . A latch assembly including: 
 a buckle; and    a tongue for releasably engaging the buckle, the tongue having a cutout;    the buckle including a base having a slot for receiving the tongue;    the buckle also including a locking pawl pivotally attached to the base and engageable by the tongue, to pivot the locking pawl so that the locking pawl engages in the cutout of the tongue when the tongue is inserted in the slot of the base; and    the buckle also including a release lever pivotally attached to the base, the release lever having a cutout receiving the locking pawl to engage the release lever when the tongue is inserted in the slot of the base.    
   
   
       2 . A latch assembly as set forth in  claim 1  wherein: 
 the tongue pivots the locking pawl in a first direction against a biasing force exerted by a first biasing member, the first biasing member biasing the locking pawl to pivot in a second direction relative to the base; and    the buckle includes a second biasing member for biasing the release lever to pivot in a first direction relative to the base.    
   
   
       3 . A latch assembly as set forth in  claim 2  wherein the release lever is pivoted in a second direction by the locking pawl upon movement of the locking pawl into the cutout in the release lever, then pivots back in the first direction.  
   
   
       4 . A latch assembly as set forth in  claim 2  wherein the release lever is manually pivotable in a second direction against the biasing force of the second biasing member to release the locking pawl from engagement with the release lever thereby to release the tongue for removal from the buckle.  
   
   
       5 . A latch assembly as set forth in  claim 1  wherein the locking pawl has a generally L-shaped configuration including a first leg that is engageable by the tongue to pivot the locking pawl in the first direction and a second leg that pivots into the cutout in the tongue and the cutout in the release lever.  
   
   
       6 . A latch assembly as set forth in  claim 5  wherein the second leg of the locking pawl is engageable with a surface on the release lever to block removal of the tongue from the buckle.  
   
   
       7 . A latch assembly as set forth in  claim 1  further including a tamper detection device.  
   
   
       8 . A latch assembly as set forth in  claim 1  wherein the tamper detection device includes a mechanism for indicating pivoting movement of the release lever.  
   
   
       9 . A latch assembly including: 
 a buckle; and    a tongue that is movable in a first direction into engagement with the buckle and in a second direction opposite the first direction out of engagement with the buckle;    the tongue having a leading edge portion and a trailing edge portion on opposite sides of an opening in the tongue;    the leading edge portion having a leading edge of the tongue that is presented in the first direction;    the trailing edge portion having a trailing edge of the tongue that is presented in the first direction and that partially defines the opening in the tongue;    the buckle having a pivotally supported locking pawl that is engageable sequentially by the leading edge of the tongue and by the trailing edge of the tongue to pivot the locking pawl in a locking direction by a first amount and by a second amount so that the locking pawl engages in the opening of the tongue when the tongue is engaged with the buckle.    
   
   
       10 . A latch assembly as set forth in  claim 9  wherein the buckle further includes a release lever; 
 the release lever having an edge surface defining a second opening for receiving the locking pawl when the locking pawl pivots by the second amount, the locking pawl engaging on the edge surface of the release lever to block pivoting movement of the locking pawl in a release direction thereby to block removal of the tongue in the second direction from the buckle.    
   
   
       11 . A latch assembly comprising: 
 a buckle, and a tongue releasably engageable with the buckle;    the buckle including a base, a locking pawl engageable by the tongue and pivotally supported on the base for movement in a locking direction and a release direction, and a release lever pivotally supported on the base and engageable by the locking pawl;    the latch assembly having a latched and tensioned condition in which the tongue is engaged with the buckle, tension on the tongue pulls the tongue against the locking pawl and pulls the locking pawl against the release lever, and the engagement of the locking pawl with the release lever blocks movement of the locking pawl and thereby blocks movement of the tongue out of the buckle;    the latching assembly being movable out of the latched and tensioned condition by moving the release lever thereby to release the locking pawl for movement under tension applied by the tongue, thereby to release the tongue for movement out of the buckle.    
   
   
       12 . A latch assembly as set forth in  claim 11  wherein the release lever has a cutout and an edge surface at least partially defining the cutout; 
 when the latch assembly is in the latched and tensioned condition a portion of the locking pawl extending into the cutout in the release lever and engaging the edge surface of the release lever, the engagement of the locking pawl portion with the edge surface of the release lever blocking movement of the locking pawl and thereby blocking movement of the tongue out of the buckle.    
   
   
       13 . A latch assembly as set forth in  claim 11  wherein the locking pawl is pivotable in the locking direction under force applied by the tongue to move the latch assembly into the latched and tensioned condition, pivotal movement of the locking pawl in the locking direction lifting the release lever from a rest position to enable the locking pawl portion to move into the cutout in the release lever, the release lever pivoting back to the resting condition under the force of a return spring to place the edge surface in a position in which it blocks pivotal movement of the locking pawl in the release direction under tension on the tongue.  
   
   
       14 . A method of releasably engaging a latch assembly, comprising the steps of: 
 inserting a tongue into a slot of a buckle;    engaging a first leg of a pivotally mounted locking pawl of the buckle with the tongue;    pivoting the locking pawl under force applied by the tongue so that a second leg of the locking pawl moves through a cutout in the tongue into engagement with a release lever of the buckle;    pivoting the release lever under force applied by the second leg of the locking pawl; and    moving the second leg of the locking pawl into a cutout in the release lever, while the second leg of the pawl extends through the cutout in the tongue.    
   
   
       15 . A method as set forth in  claim 14  wherein the step of pivoting the locking pawl so that a second leg of the locking pawl moves through a cutout in the tongue into engagement with a release lever of the buckle, comprises pivoting the locking pawl in a first direction against a first biasing force; 
 the step of moving the second leg of the pawl into a cutout in the release lever comprises further pivoting the locking pawl in the first direction against the first biasing force; and    the step of pivoting the release lever with the second leg of the pawl comprises pivoting the release lever in a first direction against a second biasing force.    
   
   
       16 . A method as set forth in  claim 15  further comprising the steps of: 
 pivoting the release lever in a second direction under the second biasing force, after the second leg of the locking pawl moves into the cutout in the release lever, and    engaging the second leg of the locking pawl with an edge surface of the release lever to block further pivoting movement of the locking pawl in the second direction under the second biasing force.    
   
   
       17 . A method as set forth in  claim 16  further comprising the steps of: 
 pivoting the release lever in the first direction under a manually applied release force opposite to the second biasing force so that the locking pawl is not in the cutout of the release lever; and    pivoting the locking pawl in the second direction under the first biasing force to move the locking pawl out of the cutout in the tongue.