Braking system for pulley block - utilises tension in rope to press rubber shoe into pulley groove

摘要

The pulley block has two side plates supporting a spindle for the pulley. When a load is being lowered the rope on the side opposite to the load is led into the groove of a small block and then into the groove of a semi-circular block fixed to the side plate. The tension in the rope pushes the small block to overcome the resistance of its resilient mounting bush. A rubber shoe is pressed into the groove of the pulley and acts as a brake to check the speed of descent of the load.