Rotation lock device, lever hoist, and hoisting machine

A lever hoist comprising:

• a load sheave which is pivotally supported by a pair of frames and around which a chain configured to hoist a cargo is wound;
• a drive shaft coupled to the load sheave via a reduction gear;
• a brake attached to the drive shaft;
• and
• an operation lever configured to perform a rotation drive operation on the load sheave in a hoisting direction and a lowering direction, wherein
• on an outer periphery of the drive shaft, a rotation lock is arranged;
• the rotation lock comprising:
• a stopper support attached to a shaft-shaped member and rotating integrally with the shaft-shaped member;
• a stopper supported by the stopper support in a state of being slidable outward from an axial center side of the shaft-shaped member;
• a holder to hold the stopper at a predetermined position of the stopper support;
• an urger to urge the holder toward a first rotation direction being one rotation direction with respect to the stopper;
• and
• a stopper lock to stop a rotation of the shaft-shaped member by engaging with the stopper, wherein
• when the shaft-shaped member accelerates the rotation toward the first rotation direction, a holding force for the stopper by the holder is decreased and/or released by an inertial load of the holder to cause the stopper to project from the predetermined position to a position where the stopper engages with the stopper lock to thereby stop the rotation of the shaft-shaped member, and
• the shaft-shaped member is the drive shaft;
• and
• the stopper lock is attached to the frame.

A hoisting machine having a frame in a plate shape, comprising:

• a brake including a ratchet including:
• a ratchet wheel which is attached to a periphery of a shaft-shaped member and has a ratchet tooth on an outer peripheral side;
• a pawl which engages with the ratchet tooth;
• and a pawl shaft which pivotally supports a turn of the pawl, the ratchet being configured to allow a rotation in a hoisting direction of the ratchet wheel by engagement between the ratchet tooth and the pawl and to disallow a rotation in a lowering direction;
• and
• a rotation lock to lock a rapid rotation of the shaft-shaped member,
• the rotation lock comprising:
• a stopper support attached to the shaft-shaped member and rotating integrally with the shaft-shaped member;
• a stopper supported by the stopper support in a state of being slidable outward from an axial center side of the shaft-shaped member;
• a holder to hold the stopper at a predetermined position of the stopper support;
• an urger to urge the holder toward the lowering direction with respect to the stopper;
• and
• a stopper lock to stop a rotation of the shaft-shaped member by contact with the stopper, wherein
• when the shaft-shaped member accelerates the rotation toward the lowering direction, a holding force for the stopper by the holder is released by an inertial load of the holder to cause the stopper to project from the predetermined position to a position where the stopper engages with the stopper lock to thereby stop the rotation of the shaft-shaped member.