Drive system for hoist especially lift cabin has a centrifugal ring driven to monitor the speed of the drive shafts to apply safety brakes

摘要

A drive system, especially for a lift cabin, has two drive motors (1) with coaxial drive shafts (6) onto which are looped the lift cables etc, The inner ends of the drive shafts meet at a speed sensing system (19) incorporating centrifugal rings whose radial displacement. Safety brakes (2) on the shafts are activated when the speed of the shafts and/or the cables exceeds a preset value.