To solve a problem that impact force in start up of auxiliary motor is large and large capacity battery is required due to high start up current and the auxiliary motor acts as resistance in hand wheel operation.

In a chain block transmitting rotation of the hand wheel 1 to a drive shaft 10 via a transmission mechanism and rotating a load sheave 11 via a reducing mechanism 13 rotatably installed on the drive shaft externally, the hand wheel 1 and the transmission mechanism are provided on one side of the load sheave 11, and the auxiliary motor 15 linking with the drive shaft 10 via an electromagnetic clutch 16 is provided on another side of the load sheave 11.