Electronic latch retraction for mortise lock and methods of operation
AssigneeASSA ABLOY Access and Egress Hardware Group, Inc.
InventorsDaniel Riley, Ian Sweeney
Life of this patent
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Abstract
A mortise lock and motor-assisted method of operating. The mortise lock comprises a case, a lever arm, a latch bolt having a linkage, a PCB having a controller and a microprocessor, and a motor assembly. An actuating element including a projection is disposed outside the motor assembly to move the latch bolt from the extended to retracted positions. The microprocessor is configured to detect a stall signal during the motor assembly's initial cycle operation indicating failure of a latch bolt retraction parameter. Upon detection of the stall signal, the controller causes the motor assembly to perform a second cycle operation to move the latch bolt from the extended position to the retracted position.
Claims17
A motor assembly in combination with a mortise lock, the mortise lock comprising:
- a PCB comprising a controller and a microprocessor;
- and
- said motor assembly comprising:
- a motor;
- a shaft translatable within the motor;
- an actuation housing forming an actuation housing channel therein;
- and
- an actuating element secured to an end of the shaft and moveable within the actuation housing channel, the actuating element including a projection disposed outside the actuation housing and extending normal to a longitudinal axis of the shaft, the actuating element offset from the shaft and coplanar with a lever arm of the mortise lock;
- wherein the motor assembly is configured to initiate an initial cycle operation upon receipt of a power signal from the PCB, the initial cycle operation capable of moving a latch bolt of the mortise lock from an extended position to a retracted position wherein a first portion of the latch bolt remains inside a mortise lock case of the mortise lock.
A method of actuating a motor-assisted mortise lock, the method comprising:
- identifying, by a microprocessor, a number of incremental positions remaining in an initial cycle operation of a motor assembly when a stall signal is detected during the initial cycle operation indicating failure of a latch bolt retraction parameter;
- initiating, by a controller, a second cycle operation of the motor assembly for the number of incremental positions remaining to move a latch bolt from an extended position to a retracted position within the latch bolt retraction parameter;
- and
- applying a holding current to the motor assembly to maintain the latch bolt in the retracted position;
- wherein the second cycle operation of the motor assembly comprises a motor speed less than a motor speed of the initial cycle operation and an electrical current greater than an electrical current of the initial cycle operation.
A method of operating a motor-assisted mortise lock, the method comprising:
- supplying a PCB of the mortise lock with a power signal;
- sending the power signal to a motor assembly of the mortise lock, the motor assembly comprising:
- a motor;
- a shaft translatable within the motor;
- an actuation housing forming an actuation housing channel therein;
- and
- an actuating element secured to an end of the shaft and moveable within the actuation housing channel, the actuating element including a projection disposed outside the actuation housing and extending normal to a longitudinal axis of the shaft, the actuating element offset from the shaft and coplanar with a lever arm of the mortise lock;
- initiating an initial cycle operation of the motor assembly to cause the actuating element to engage the lever arm and move a latch bolt of the mortise lock from an extended position to a retracted position;
- monitoring, by a microprocessor, the initial cycle operation to detect a stall signal indicating failure of a latch bolt retraction parameter;
- moving the latch bolt from an extended position to a retracted position within the latch bolt retraction parameter;
- and
- applying a hold current to the motor assembly to maintain the latch bolt in the retracted position.
Dependencies are inferred from the claim text.