Abstract: A brake device comprising: a brake receiver pivotally supported in a non-rotatable manner on the drive shaft and including a flange part and a boss part; a female screw member pivotally supported in a rotatable manner on the drive shaft and screwed to a male screw part; a ratchet wheel including ratchet teeth provided on an outer peripheral side and configured to restrict a rotation direction to one direction; a brake plate arranged between the ratchet wheel and at least one of the flange part and the female screw member; and at least one pawl member engaging, on a tip side, with a valley part located between adjacent ratchet teeth, and meshing with the ratchet tooth, wherein the ratchet teeth include tall teeth and short teeth lower in projection height from a rotation center of the ratchet wheel than the tall teeth.

Abstract: A chain block includes: a main body frame; and a gear cover that is attached to the main body frame to form an internal space sealed off from an outside between the gear cover and the main body frame, and rotatably supports one end side of a reduction gear member, wherein a gear-side frame part is provided with a bottom part and an outer peripheral wall part projecting from an outer peripheral edge portion of the bottom part, and an upper rib having both ends coupled to the outer peripheral wall part is provided at a portion of the gear-side frame on an upper side where an insertion hole and a link shaft are provided and on a side nearer a center of the internal space than is the outer peripheral wall part, and the upper rib is provided adjacent to the insertion hole and the link shaft.

Abstract: A chain block includes: a main body frame; and a gear cover that is attached to the main body frame to form an internal space sealed off from an outside between the gear cover and the main body frame, and rotatably supports one end side of a reduction gear member, wherein a gear-side frame part is provided with a bottom part and an outer peripheral wall part projecting from an outer peripheral edge portion of the bottom part, and an upper rib having both ends coupled to the outer peripheral wall part is provided at a portion of the gear-side frame on an upper side where an insertion hole and a link shaft are provided and on a side nearer a center of the internal space than is the outer peripheral wall part, and the upper rib is provided adjacent to the insertion hole and the link shaft.