Door latch mechanism controlling switch in microwave oven or the like
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorTatsuji Isono
Life of this patent
Estimating the term…
Abstract
A door latch mechanism which may be advantageously used for a door of electrical equipment such as a microwave oven, comprising a latch member on the door, catch means to engage the latch member when the door is closed, and resilient biasing means to bias the catch means into a position engaging the latch member. The catch means is moved into and out of the position to engage the latch member by means of a leverage linkage and the movement of the catch member into and out of the position to engage the latch member is transmitted to electric switch means through the leverage linkage. The door is opened only after the switch means has been made open.
Claims14
A latch mechanism for latching a door structure to a casing, comprising in combination a latch member movable with the door structure,
- a support member fixedly mounted on the casing,
- catch means supported on the support member and having a first position engageable with the latch member for latching the door structure to the casing and a second position engageable with the latch member for maintaining the door structure unlatched from the casing,
- resilient biasing means responsive to movement of the catch means between the first and second positions thereof and operative to bias the catch means toward the first position when the catch means is moved toward and into the first position thereof and to bias the catch means toward the second position when the catch means is moved toward and into the second position,
- electric switch means having a closed condition responsive to the movement of the catch means into the first position thereof and an open condition responsive to the movement of the catch means toward the second position thereof,
- leverage linkage means which is engageable at one end with said catch means and at the other end with said electric switch means for amplifying and transmitting the movement of the catch means to the first or second position thereof to the switch means, and
- manually-operated unlatching means responsive to the first position thereof and movable between a first position to allow the catch means to stay in the first position thereof and a second position to hold the catch means out of the first position thereof, said unlatching means being held in the first position thereof when the catch means is in the first position thereof and being moved to the second position thereof when manually operated, said leverage linkage means being engageable at said one end with the unlatching means for transmitting the movement of the unlatching means toward the second position thereof to the switch means and thereby actuating the switch means into said open condition when the unlatching means is manually moved into the second position thereof.
A latch mechanism for latching a door structure to a casing, comprising in combination a latch member movable with the door structure,
- a support member fixedly mounted on the casing,
- catch means supported on the support member and having a first position engageable with the latch member for latching the door structure to the casing and a second position unengageable with the latch member for maintaining the door structure unlatched from the casing,
- resilient biasing means responsive to movement of the catch means between the first and second positions thereof and operative to bias the catch means toward the first position when the catch means is moved toward and into the first position thereof and to bias the catch means toward the second position when the catch means is moved toward and into second position,
- manually-operated unlatching means movable between a first position to allow the catch means to stay in the first position thereof and a second position to hold the catch means out of the first position thereof,
- electric switch means having a closed condition responsive to the movement of the catch means into the first position thereof and an open condition responsive to the movement of the catch means toward the second position thereof,
- a first leverage linkage means which is engageable at one end with said manually-operated unlatching means and at the other end with said catch means for transmitting the movement of said manually-operated unlatching means toward the second position thereto to the latch means for moving the catch means to the second position thereof when said manually-operated unlatching means is manually moved to the second position thereof,
- a second leverage linkage means which is engageable with said latch member and biased by said resilient biasing means toward a position to urge said latch member out of the first position thereof, and
- a third leverage linkage means engaging at one end with the catch means and at the other end with said switch means for transmitting and amplifying the movement of the catch means of the first or second position thereof.
Dependencies are inferred from the claim text.