7.4.3 Worm Geared Wall Winch

The worm geared wall winch is designed to be bolted to a wall or other vertical face. This type of winch is used for general lifting operations and is often built into jib cranes, mobile supporting structures and similar structures. Worm geared winches are manually operated from the front of the unit.

The design permits the wire rope to be taken off the drum either vertically upward or horizontally. Generally available in a range of capacities from 250 kg to 2 tonnes, these winches have single speed operation, although some models are available with a no load fast rope reeling facility. Some designs are self sustaining due to the worm/gear wheel ratio whilst others utilize a self sustaining brake with ratchet and pawl. Rope drum storage capacities vary between 20 metres and 60 metres. (See Figure 7.4.3-1 )