Motorized oven door latch assembly

Abstract

A compact, reliable motorized oven door latch assembly utilizes a latch that pivotally connects to a motor at an axis that is offset from the motor's axis. The latch includes a latch guide that is guided by a slot in a housing of the assembly. Rotation of the motor moves the latch between open and closed positions. A cam rotationally engages the motor and includes axially disposed cam surfaces that interact with side-by-side switches to sense when the latch is open and closed. The assembly includes a reusable release/service feature that allows the latch to be opened without operation of the motor if the latch becomes stuck in the closed position. The service feature includes a resiliently deformable flange that defines part of the guide surface.

1 . An oven door latch assembly for locking an oven door in a closed position, the assembly comprising: 
 a housing;    a motor mounted to the housing, the motor including an output shaft that defines a motor axis; and    an oven door latch pivotally connected to the output shaft at a latch axis that is offset from the motor axis, the latch being pivotable relative to the output shaft about the latch axis, wherein rotational movement of the output shaft moves the oven door latch between open and closed positions.    
   
   
       2 . The oven door latch assembly of  claim 1 , further comprising: 
 a cam mounted to the output shaft to rotate with the output shaft about the motor axis, the cam having a first cam surface that faces a direction parallel to the motor axis; and    a first switch disposed on the housing and positioned to be actuated by the first cam surface.    
   
   
       3 . The oven door latch assembly of  claim 2 , wherein the oven door latch pivotally connects to the output shaft via a pivotal connection between the cam and oven door latch.  
   
   
       4 . The oven door latch assembly of  claim 2 , wherein the cam further comprises a second cam surface that faces a direction parallel to the motor axis, and wherein the assembly further comprises a second switch disposed on the housing and positioned to be actuated by the second cam surface.  
   
   
       5 . The oven door latch assembly of  claim 4 , wherein the first cam surface is disposed farther from the motor axis than the second cam surface.  
   
   
       6 . The oven door latch assembly of  claim 4 , wherein the first cam surface and first switch are positioned such that the first cam surface actuates the first switch when the oven door latch is in the closed position.  
   
   
       7 . The oven door latch assembly of  claim 6 , wherein the second cam surface and second switch are positioned such that the second cam surface actuates the second switch when the oven door latch is in the open position.  
   
   
       8 . The oven door latch assembly of  claim 2 , further comprising: 
 a guide surface disposed on one of the housing and the oven door latch; and    a latch guide disposed on the other of the housing and the oven door latch,    wherein abutting contact between the latch guide and guide surface guides the oven door latch as it moves between the open and closed positions.    
   
   
       9 . The oven door latch assembly of  claim 8 , wherein the guide surface is disposed on the housing and the latch guide is disposed on the oven door latch.  
   
   
       10 . The oven door latch assembly of  claim 9 , wherein the latch guide and oven door latch are integrally formed.  
   
   
       11 . The oven door latch assembly of  claim 9 , wherein the guide surface is defined by a slot in the housing.  
   
   
       12 . The oven door latch assembly of  claim 8 , further comprising a deformable element that defines a portion of the guide surface, wherein the deformable element is deformable in a direction that allows the oven door latch to move from the closed position into the open position without rotation of the output shaft.  
   
   
       13 . The oven door latch assembly of  claim 2 , in combination with an oven comprising an oven door having open and closed positions, wherein the assembly locks the oven door closed when the oven door is closed and the latch moves from its open to its closed position, and wherein the latch permits the oven door to be opened when the latch is in its open position.  
   
   
       14 . A method of making an oven door latch assembly for locking an oven door in a closed position, the method comprising: 
 mounting a motor to a housing, wherein the motor includes an output shaft that defines a motor axis;    providing a guide surface on the housing,    integrally forming a latch guide with an oven door latch; and    pivotally connecting the oven door latch to the output shaft at a latch axis that is offset from the motor axis, wherein the pivotal connection allows the latch to pivot relative to the output shaft about the latch axis, wherein rotational movement of the output shaft moves the oven door latch between open and closed positions, wherein the cam track has a guide surface, and wherein the latch guide abuts and is guided by the guide surface as the oven door latch moves between the open and closed positions.    
   
   
       15 . The method of  claim 14 , wherein integrally forming the latch guide with the oven door latch comprises stamping the latch guide into the oven door latch.  
   
   
       16 . An oven door latch assembly for locking an oven door in a closed position, the assembly comprising: 
 a housing;    a motor carried by the housing, the motor including an output shaft that defines a motor axis;    an oven door latch pivotally connected to the output shaft at a latch axis that is offset from the motor axis, the pivotal connection allowing the latch to pivot relative to the output shaft about the latch axis, wherein rotational movement of the output shaft moves the oven door latch between open and closed positions;    a latch guide integrally formed with the oven door latch; and    a cam track disposed on the housing and having a guide surface,    wherein the latch guide abuts and is guided by the guide surface as the oven door latch moves between the open and closed positions.    
   
   
       17 . The oven door latch assembly of  claim 16 , wherein the cam track and guide surface are defined by a slot in the housing.  
   
   
       18 . The oven door latch assembly of  claim 16 , wherein the latch guide is stamped into the oven door latch.  
   
   
       19 . The oven door latch assembly of  claim 16 , wherein the latch guide is one of stamped into, molded with, or cast with the oven door latch.  
   
   
       20 . The oven door latch assembly of  claim 16 , in combination with an oven comprising an oven door having open and closed positions, wherein the assembly locks the oven door closed when the oven door is closed and the latch moves from its open to its closed position, and wherein the latch permits the oven door to be opened when the latch is in its open position.