ELECTRIC CHAIN BLOCK

PROBLEM TO BE SOLVED: To provide an electric chain block with only a small upper dead space, capable of automatically setting the maximum quantity and minimum quantity of movement of a load chain and preventing excessive hoisting up/down of the load chain. SOLUTION: The electric chain block comprises a friction clutch, a load chain movement detector 34, and an operation device with a hoist-up switch 21, a hoist-down switch 22, a high speed switch 23 and a low speed switch 24. The electric chain block also has an excessive hoist-up/down preventive control device 30 comprising a setting means 31, a memory 32, a stopping means 33 for automatically setting the maximum quantity and minimum quantity of movement based on the quantity of movement of the load chain when the friction clutch is making the friction motion by the hoist up/down motion. The stopping means 33 stops the hoist-up motion or the hoist-down motion when the quantity of movement of the load chain detected by the load chain movement detector 34 in the hoist-up/down motion is the maximum or minimum quantity of movement of the load chain. COPYRIGHT: (C)2003,JPO