Safety Brake for a Lifting Gear

摘要

A safety brake for a load lifting gear includes an actuator for a locking pawl, a brake-locking gear element connected to a lifting gear drive, pawl position monitoring sensors and a controller. The controller monitors the sensors and the lifting gear speed, and operates the lifting gear drive and the actuator to brake the lifting gear against excessive speed, by moving the actuator between energized and non-energized states and differentiating with sensor inputs among a detached state, a bearing state and a fully engaged state of the locking pawl with a pawl clearance of the brake-locking gear element.

主权项

1. In a safety brake for a lifting gear drivable for raising and lowering a load, the safety brake including a brake-locking gear element connected to a drive of the lifting gear, and a locking pawl for meshed engagement with a pawl clearance of the brake-locking gear element to halt continued motion of the brake-locking gear element in response to an excessive lowering speed of the lifting gear, the improvement comprising:
an actuator for activating the locking pawl, the actuator and the locking pawl being configured and disposed so that, (i) in a non-energized state of the actuator, the locking pawl one of bears on the brake-locking gear element and engages in the pawl clearance of the brake-locking gear element, and (ii) in an energized state of the actuator, the locking pawl one of detaches from the brake-locking gear element and disengages from the pawl clearance, and releases the brake-locking gear element; at least three sensors arranged for monitoring positions of the locking pawl; and a controller, comprising one of an electronic controller and a numeric controller and connected to the at least three sensors, operable for controlling the drive of the lifting gear and for activating the actuator, wherein the controller is configured for monitoring the lowering speed of the lifting gear and, if an excessive monitored lowering speed is sensed, for switching the actuator to the non-energized state, and the controller being connected to the at least three sensors for determining an operating state of the locking pawl and differentiating between a detached operating state, a bearing operating state and a fully engaged operating state in which the locking pawl is fully engaged in the pawl clearance of the brake-locking gear element.