Door latch interlock system for microwave oven

In a microwave oven having a cabinet defining an oven cavity provided with an opening, a closure mounted to said cabinet for movement between a closed position closing said opening and an open position providing access to said opening, electrically operable microwave energy generating means for supplying microwave energy to said cavity, and an electrical circuit including a plurality of switches carried by said cabinet for controlling delivery of electric power from an external source to said generating means, improved means for selectively securing said closure in a closed position wherein the closure sealingly closes said opening comprising:

• a guide on said cabinet;
• a slider member movably carried by said guide for movement between released and latching positions;
• catch means carried by said slider member;
• means for biasing said slider member toward the latching position at all times;
• latch means carried by said closure and engageable with said catch means to latch the closure in the closed position as an incident of said closure being moved to said closed position with said slider member being disposed in said latching position;
• actuator means carried by said closure for operating one of said switches to permit operation of said generating means only when said closure is latched in said closed position;
• manually operable means carried by said closure for arranging said actuator means to cause said one switch to prevent operation of the generating means and concurrently move said slider member to said released position against the action of said biasing means for unlatching said latch means from said catch means with said closure disposed in said closed position, thereby permitting the unlatched closure to be moved selectively from said closed position to said open position;
• and
• means carried by said latch means for causing a second of said switches to permit operation of said generating means only when the closure is in the closed position.

In a microwave oven having a cabinet defining a cavity having an access opening, a closure for selectively sealingly closing said opening having a handle thereon, and microwave generating means for producing microwave energy within said cavity, means for releasably securing said closure in the closed position and concurrently electrically connecting said generating means to a source of electrical potential comprising:

• a vertical support extending along an edge of said closure, said support having horizontal extending arms fixed thereon, each of said arms having vertically downwardly extending fingers at a distal end;
• a pair of interconnected arms pivoted from said support in vertically spaced relationship to each other, said pivoted arms extending horizontally from said support, a lower of said pivoted arms having a downwardly extending finger thereon:
• a vertically disposed guide channel within said cabinet having an upwardly biased slide channel positioned for vertical reciprocating movement therein, said guide channel and said slide channel having aligned apertures for receiving said arms when said closure is in said closed position, said slide channel having horizontal pins mating in locking relationship with said fingers on said fixed arms when said closure is in said sealing relationship, said guide channel having a secondary switch and a monitor switch mounted thereon engaged by said fixed arms and operated to an "on" position of said generating means when said closure is moved to said sealing relationship;
• a guide roller on said slide channel operable when said pins move to lock the fixed arms to bear against and pivot an upper of the pivoted arms, said pivot movement operating through said interconnection to rotate said lower pivoted arm to bring said finger on said lower pivoted arm into moving contact with a primary interlock switch, said moving contact closing said switch;
• and
• pushbutton means connected to said closure handle for freeing said pins from said fixed arm fingers and for removing said lower pivoted arm contact from said primary interlock switch, said button means being inwardly movable to bear against a vertical portion of the upper pivoted arm to pivot said upper pivoted arm against said roller to move said slide channel downwardly releasing said pins from said fixed arm fingers, whereby an outward force applied to said closure handle after pushing said pushbutton means will allow movement of said door out from said closed position and concurrently cause said monitor and secondary switches to be in an "off" condition to de-energize said generating means.