Tamper resistant appliance latch

Patent metadata

Field	Value
Publication number	US-10316454-B2
Application number	US-201415039873-A
Country	US
Kind code	B2
Filing date	Oct 9, 2014
Priority date	Dec 4, 2013
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

An appliance latch receives a strike when the appliance lid is closed and provides an electrically activated lock holding the lid closed during portions of the wash cycle that might present a hazard. The strike presents two different surfaces to the latch, the first to activate a lock mechanism and the second to activate an anti-tamper switch before the appliance may be actuated thereby reducing the risk of tampering.

First claim

What is claimed is:

1. An appliance latch assembly comprising:
a striker and a corresponding latch for receiving the striker, the striker and latch positionable on an appliance lid and appliance frame;
a trap contacting a first feature of the striker to move the trap from a first trap position to a second trap position as the striker is received by the latch and providing a surface holding the striker in the latch when the trap is in the second trap position;
an electrically actuated lock actuable when the trap element is in the second position to hold the trap in the second trap position;
an anti-tamper operator contacting a second feature of the striker different from the first feature to move from a first operator position to a second operator position when the trap moves to the second operator position;
a first electrical switch communicating with the lock to provide an indication that the lock is actuated to hold the trap in the second trap position;
a second electrical switch operating independently from the first electrical switch and communicating with the anti-tamper operator to provide an indication that the anti-tamper operator is in the second operator position; and
wherein the first and second features are first and second forks of a bifurcation, the first and second forks passing on opposite sides of a stationary ward plate before they can activate the first electrical switch and second electrical switch respectively;
wherein the anti-tamper operator and the trap move in a same direction in parallel to each other when the striker is received by the latch, and the trap moves from the first trap position to the second trap position and the anti-tamper operator moves from the first operator position to the second operator position;
wherein the first and second forks are on a front surface of the striker and wherein the different forks of the bifurcation pass on opposite sides of the stationary ward plate when the striker engages the latch; and
wherein the striker provides a hook portion extending generally perpendicularly to a direction of engagement of the striker and the latch and wherein the bifurcation is in the hook portion.

2. The appliance latch of claim 1 wherein the striker includes a hinge allowing it to move with the trap.

3. The appliance latch assembly of claim 2 wherein the striker is received in the latch along an axis and may travel perpendicularly to the axis as it is received within the latch as the trap moves between the first trap position and the second trap position.

4. The appliance latch assembly of claim 3 wherein the striker may travel along the axis without traveling perpendicularly to the axis after the trap moves to the second trap position.

5. The appliance latch assembly of claim 3 wherein the striker is pivoted for travel perpendicularly to the axis and includes a spring urging the striker in a first direction perpendicular to the axis.

6. The appliance latch assembly of claim 5 wherein the electrically actuated lock is a solenoid and bistable mechanism moving a blocking element between receipt by the trap and removal from the trap with successive energizing of the solenoid.

7. The appliance latch assembly of claim 6 further wherein motion of the striker to disengage the striker from the latch when the blocking element is received by the trap causes an abutting of the blocking element against a frangible portion of the trap which when broken prevents activation of the lock switch.

8. The appliance latch assembly of claim 7 wherein the frangible portion of the trap supports a spring element away from an opening into which the blocking element may be received such that removal of the frangible element causes the spring element to occlude the opening.

9. The appliance latch of claim 2 wherein the surface of the trap holding the striker in the latch holds the striker in engagement against a stationary portion of the latch when the trap moves to the second trap position.

10. A washing machine having a spin basket and operated by a motor, a lid providing access to the spin basket in an open state, and further including an appliance control receiving a signal generated at least in part from a lock signal indicating that the lid is closed and locked, and an appliance latch comprising:
a striker and a corresponding latch for receiving the striker, the striker and latch positionable on an appliance lid and an appliance housing;
a trap contacting a first feature of the striker to move the trap from a first trap position to a second trap position as the striker is received by the latch and providing a surface holding the striker in the latch when the lock element is in the second trap position;
an electrically actuated lock actuable when the trap element is in the second position to hold the trap in the second trap position;
an anti-tamper operator contacting a second feature of the striker different from the first feature to move from a first operator position to a second operator position when the trap moves to the second operator position;
a first electrical switch communicating with the lock to provide the lock signal indicating that the lock is actuated to hold the trap in the second trap position; and
a second electrical switch operating independently from the first electrical switch communicating with the anti-tamper operator to provide an indication that the anti-tamper operator is in the second operator position; and
wherein the first and second features are first and second forks of a bifurcation, the first and second forks passing on opposite sides of a stationary ward plate before they can activate the first electrical switch and second electrical switch respectively;
wherein the anti-tamper operator and the trap move in a same direction in parallel to each other when the striker is received by the latch, and the trap moves from the first trap position to the second trap position and the anti-tamper operator moves from the first operator position to the second operator position;
wherein the first and second forks are on a front surface of the striker and wherein the different forks of the bifurcation pass on opposite sides of the stationary ward plate when the striker engages the latch; and
wherein the striker provides a hook portion extending generally perpendicularly to a direction of engagement of the striker and the latch and wherein the bifurcation is in the hook portion.

Assignees

• Illinois Tool Works

Inventors

• Mcdonald Randy S
• Bragg Joel C
• Krieger Jeffrey J

Classifications

• E05B47/0004

  said core being linearly movable · CPC title

• D06F37/42 Primary

  Safety arrangements, e.g. for stopping rotation of the receptacle upon opening of the casing door · CPC title

• D06F23/04

  and rotating or oscillating about a vertical axis · CPC title

• E05B47/0002

  with electromagnets · CPC title

• E05B2047/0081

  Same pulse to lock or unlock · CPC title