A safety device that detects slack in the suspension or compensation ropes and stops the elevator to prevent damage or danger.
Full Definition
The slack rope device is a safety switch—usually a spring-loaded lever or roller actuated by rope tension—installed on the rope compensation assembly, tension sheave, or car rope hitch. It operates when rope tension falls below a preset threshold, indicating that ropes have gone slack due to a buffer strike, obstacle on top of the car, or overspeed. Activation disconnects the machine brake circuit, stopping the drive. The device is particularly important in hydraulic lifts and roped hydraulic systems where hose failure can cause rope slack. EN 81-20 requires that the elevator cannot restart until the rope is re-tensioned and the device is manually reset.
