Electromechanical sensing and safety actuation of elevator governors
Elevator system governors include a housing, a first pulley, a second pulley, and a cable wound about the two pulleys. A target element is arranged on at least one of the pulleys and a motion sensor assembly is arranged to detect the target element and determine if an overspeed condition is present. An electromagnet is operably coupled to the motion sensor assembly that is configured to transition the electromagnet from a first electromagnetic state to a second electromagnetic state in response to a detected overspeed condition. A trigger arm is releasably connected to the electromagnet and configured to actuate a safety brake assembly with a biasing element arranged to bias the trigger arm into an actuated state with a magnetic force of the electromagnet being greater than a biasing force of the biasing element when the electromagnet is in the first electromagnetic state.
1 . An elevator system governor comprising:
a housing configured to be mounted to a traveling component of an elevator system;
a first pulley arranged on the housing;
a second pulley arranged on the housing;
a cable wound about the first pulley and the second pulley, wherein the first and second pulleys are configured to travel along the cable;
a target element arranged on at least one of the first pulley and the second pulley;
a motion sensor assembly arranged to detect the target element and determine if an overspeed condition is present based thereon;
an electromagnet operably coupled to the motion sensor assembly, wherein the motion sensor assembly is configured to transition the electromagnet from a first electromagnetic state to a second electromagnetic state in response to a detected overspeed condition;
a trigger arm releasably connected to the electromagnet and operably coupled to a safety brake assembly, wherein the trigger arm is magnetically secured to the electromagnet when the electromagnet is in the first electromagnetic state, and when the electromagnet is transitioned to the second electromagnetic state, the trigger arm is configured to actuate the safety brake assembly; and
a biasing element arranged to bias the trigger arm into an actuated state, wherein a magnetic force of the electromagnet is greater than a biasing force of the biasing element when the electromagnet is in the first electromagnetic state.
2 . The elevator system governor of claim 1 , further comprising a reset arm, wherein the electromagnet is fixedly attached to the reset arm.
3 . The elevator system governor of claim 2 , further comprising a reset assembly arranged to cause the reset arm to move the electromagnet into contact with the trigger arm when the trigger arm is in the actuated state.
4 . The elevator system governor of claim 3 , wherein the reset assembly is configured to apply a force to the reset arm and the trigger arm, via the electromagnet, to overcome the biasing force of the biasing element, and reset the trigger arm to a normal operating state.
5 . The elevator system governor of claim 3 , wherein the reset assembly comprises a linear actuator.
6 . The elevator system governor of claim 3 , wherein the reset assembly comprises a motored gear and the reset arm comprises a toothed portion configured to be driven by the motored gear.
7 . The elevator system governor of claim 3 , further comprising an intermediate arm rotationally mounted to the reset arm, wherein the intermediate arm is configured to releasably be retained by the electromagnet and the trigger arm is configured to selectively engage with the intermediate arm.
8 . The elevator system governor of claim 1 , wherein the motion sensor assembly comprises a control element with a processing unit and a detector element arranged to detect the target element.
9 . The elevator system governor of claim 1 , further comprising:
a toothed configuration on at least one of the first pulley and the second pulley; and
a latch operably mounted to the reset arm, wherein the latch is configured to engage with the toothed configuration during a loss of power to the elevator system governor.
10 . The elevator system governor of claim 9 , wherein the latch is configured to be engaged with the toothed configuration during motion of the respective traveling component to cause actuation of the trigger arm.
11 . The elevator system governor of claim 1 , wherein the biasing element is a compression spring.
12 . The elevator system governor of claim 1 , wherein the biasing element is an expansion spring.
13 . The elevator system governor of claim 1 , wherein the traveling component is an elevator car.
14 . The elevator system governor of claim 1 , wherein the first electromagnetic state is an energized state of the electromagnet and the second electromagnetic state is a deenergized state of the electromagnet.