Hydraulically assisted rail brakes

Abstract

A hydraulic-boosted rail brake is provided for use with an elevator having a guide rail. The rail brake includes a braking plate having friction material, a spring package in communication with the braking plate, a hydraulic cylinder, a piston housed at least partially inside the hydraulic cylinder, and a brake controller. The braking plate is selectively movable relative to the guide rail, and the spring package biases the friction material to interact with the guide rail to cause braking. The piston is in communication with the braking plate and is selectively: (a) movable in a release direction to diminish or overcome force from the spring package; and (b) movable in an engage direction to supplement the force from the spring package. The brake controller selectively causes the piston to move in the release direction and in the engage direction.

Description

technical field [0001] The present invention relates to hydraulically assisted guide rail brakes for use with elevators having guide rails. Background technique [0002] Typically, an elevator includes three separate braking systems: a braking system for operating the brakes to hold the elevator car at the various floors, and a braking system for slowing the car when its upward or downward speed is excessive The braking system for emergency braking, and the braking system for safety braking to stop the car if free fall would otherwise occur. Although some prior art systems combine two or more of these braking systems into a single brake, such brakes are not capable of accurately applying braking force for each task. Thus, for example, a brake may provide both operational braking and emergency braking, but the brake may not consistently apply the correct braking force and may not consistently apply the correct emergency braking force. [0003] The present disclosure general...

Images