Patent ID: 7575223

Claim:
An overload preventing apparatus of a hoist, the overload preventing apparatus comprising: operating means for operating the hoist, the operating means having an inner peripheral face; a drive member for driving cooperatively with driving of the operating means, the drive member having an outer periphery; a drive apparatus for transmitting a driving force of the drive member to a drive shaft for driving the hoist by way of brake means; a rotation drive member located in an interval between the inner peripheral face of the operating means and the outer periphery of the drive member in sliding contact with a ring-like guide portion provided at an end face of the inner peripheral face of the operating means, the rotation drive member being engaged with the drive member and the operating means and having means for transmitting a driving force of the operating means to the drive member and restricting torque transmitted to the drive member by torque of the operating means; a spring holder; and a spring member wound around the outer periphery of the drive member in a cylindrical space formed between a back face of the rotation drive member and the spring holder, the spring member extending in an axial direction for pressing the rotation drive member to a side of the drive member, wherein the spring holder is fixed by a locking step portion of the drive member to restrict the spring holder from moving to a side of the rotation drive member by pressing against an end portion of the spring member, and the spring holder has a guide portion in sliding contact with the ring-like guide portion provided at the end face of the inner peripheral face of the operating means.