Door latch for appliance

• US 4,623,179 A
• Filed: 03/10/1986
• Issued: 11/18/1986
• Est. Priority Date: 12/27/1983
• Status: Expired due to Fees

• Current Assignee: Anvil Technologies LLC
• Original Assignee: Maytag Corporation (Whirlpool Corporation)
• Inventors: Mellinger, John C., Davis, G. Jerry
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Illich, Russell W.
• Application Number:
  US06/838,412
• Time in Patent Office: 253 Days
• Field of Search: 292/144, 292/201, 292/57-66, 292/68, 292/69, 292/DIG. 69, 68/12 R, 68/23 R
• US Class Current: 292/201
• CPC Class Codes: D06F 37/42 Safety arrangements, e.g. for stopping rotation of the receptacle upon opening of the casing door
• CPC Class Codes: Y10S 292/69 Washing machine or stove closure latch
• CPC Class Codes: Y10T 292/0887 Operating means
• CPC Class Codes: Y10T 292/1082 Motor

Abstract

A door latch is provided for the access door of an appliance. The door latch apparatus includes bracketry for mounting at least one switch and actuating levers. The movable access door includes a catch which is engageable with one of the actuating levers as the access door is closed for sensing if the access door is in a lockable posture. Another actuating lever is pivotally operated by a solenoid actuator under control of a microcontroller-based controller to position one end of the lever into locking engagement with the access door catch and to actuate a switch for providing a signal to the controller that the access door is closed and locked.

Claims

1. An appliance including an access door and latching apparatus therefor, the combination comprising:

operating means disposed within said appliance, said access door controlling access to said operating means and movable between an access-open and an access-closed position;

an electrical power source for providing electrical power between a pair of electrical conductors to power said appliance;

microcontroller-based program means for controlling operation of said appliance and said latching apparatus;

a catch mounted on said movable access door;

means for mounting said latching appatatus on said appliance generally adjacent said catch when said movable access door is in the access-closed position;

locking means including a lever member and engageable with said catch when said access door is in a closed and lockable posture;

electrically energizable actuating means operatively attached to said lever member for movement thereof between a catch-unlocked first mode and a catch-locking second mode;

switch means actuated by said lever member upon movement of said lever member to said catch-locking second mode, said locking means being operable for engagement with said catch to sense the proper positioning of said access door and operable for preventing energization of said actuating mcans when said access door is not in a closed and lockable posture and for preventing movement of the access door when said access door is properly located in said access-closed position, said lever member while moving into engagement with said catch being substantially concurrently operable for actuating said switch means from a door-unlocked first posture to a door-locked second posture to provide a signal to said microcontroller-based program means indicating that said access door is closed and locked, and monitoring means included in said microcontroller-based program means for sensing the posture of said switch means and the mode of said actuating means, said microcontroller-based program means including means for preventing operation of said appliance upon sensing said switch means in said door-locked second posture while sensing said actuating means in said catch-unlocked first mode whereby energization of said actuating means is allowed only if said access door is closed and lockable and operation of said appliance is allowed only if said access door is closed and locked.

2. An appliance including an access door and latching apparatus therefor as defined in claim 1 wherein said locking means includes a second lever member engageable by said catch with said access door in said closed and lockable posture for actuating a line switch electrically associated with said power source.

3. An appliance including an access door and latching apparatus therefor as defined in claim 2 wherein said second lever member releases said first lever member for movement concurrently with operation of said line switch.

4. An appliance including an access door and latching apparatus therefor as defined in claim 1 wherein said actuating means includes a solenoid having an armature portion operatively attached to said lever member and energizable under control of said program means from said first mode to said catch-locking second mode if said access door is sensed to be in a closed and lockable posture.

5. An appliance including an access door and latching apparatus therefor, the combination comprising:

operating means disposed within said appliance, said access door controlling access to said operating means and movable between an access-open and an access-closed position;

an electrical power source for providing electrical power between a pair of electrical conductors to power said appliance;

microcontroller-based program means for controlling operation of said appliance and said latching apparatus through a cycle of operations;

a catch mounted on said movable access door;

bracket means mounted on said appliance generally adjacent said catch with said movable access door in the access-closed position;

a line switch actuatable upon movement of said access door to said access-closed position for connecting said power source across said pair of electrical conductors to condition said appliance for operation when said access door is in the access-closed position;

a switch actuating lever movable responsive to contact by said catch for actuating said line switch, actuation of said line switch being representative of a closed and lockable posture of said access door;

a door latch lever supported on said bracket means and having a first end and a second end and being pivotable so that said second end is engageable with said catch for locking said access door in the access-closed position if said access door is in said closed and lockable posture, said door latch lever including means engageable with said switch actuating lever to prevent movement of said door latch lever if said access door is not in said closed and lockable posture;

a solenoid in circuit with said microcontroller-based program means for actuation during said cycle of operations and including an armature operatively attached to said door latch lever, said solenoid being energizable under control of said microcontroller-based program means for pivoting said door latch lever from a catch-unlocked first mode to effect engagement of said second end with said catch in a catch-locked second mode if said access door is in a closed and lockable posture;

a lock switch in circuit association with said microcontroller-based program means and actuated from a door-unlocked first posture to a door-locked second posture by said door latch; and

monitoring means included in said microcontroller-based program means for sensing the posture of said lock switch and the mode of said solenoid, said microcontroller-based program means including means for preventing operation of said appliance upon sensing said lock switch in said door-locked second posture while sensing said solenoid in said door-unlocked first mode whereby energization of said solenoid is allowed only if said access door is closed and lockable and operation of said appliance is allowed only if said access door is closed and locked.

6. An appliance including an access door and latching apparatus therefor, the combination comprising:

operating means disposed within said appliance, said access door controlling access to said operating means and movable between an access-open and an access-closed position;

an electrical power source for providing electrical power between a pair of electrical conductors to power said appliance microcontroller-based program means for controlling operation of said appliance and said latching apparatus;

a catch mounted on said movable access door;

means for mounting said latching apparatus generally adjacent said catch with said movable access door in the access-closed position and including at least a pair of vertically oriented, spaced-apart flanges;

cam means defined by a cut-out in each of said spaced-apart flanges;

latch means including first and second end portions extending through said cut-outs for engagement with said cam means, said first end of said latch means being engageable with said catch when said access door is in a closed posture to sense the presence of said catch for determining that said access door is in a closed and lockable posture;

a switch actuated by said second end portion of said latch means to provide a signal to said program means that said access door is closed and locked; and

actuating means including a solenoid mounted between said spaced-apart flanges and including an armature portion operatively attached to said latch means, said solenoid being energizable under control of said program means for effecting the locking of said access door and actuating said switch by moving said latch means with respect to said cam means, said cam means having sloped surfaces for guiding the end portions of said latch means including initial pivotal movement thereof and, if said access door is in a lockable posture, secondary linear movement for locking said access door and actuating said switch.

7. An appliance including an access door and latching apparatus therefor as defined in claim 6 wherein said cam means includes means for guiding said latch means in a path to prevent actuation of said switch means when said access door is in an unlockable posture.