Gravity operated cable brake for an elevator

摘要

A cable brake has an electromagnet releasably retaining a mass that falls down guide rods under the effect of gravity and impacts a first arm of a trigger lever. Upon impact by the mass, the trigger lever rotates a second arm with a pawl to release a crossbar, whereupon pressure springs press a moveable brake plate against a cable strand to halt the cable strand. A return mechanism utilizes a screw and cooperating nut or a coupler to return the moveable brake plate and pre-stress the pressure springs.