Abstract: A safety device of an air balancing hoist according to the present invention is provided to instantaneously brake a reel drum in the manner that a braking pawl mounted to be rotatable on an end cap is pushed to the outside direction of the circumference of a circle by centrifugal force to be locked into a ratchet wheel fixed on the end cap when the reel drum is suddenly fast rotated during a hoisting process.

Abstract: The present invention relates to a safety device for an air balancing hoist for braking and finally stopping a reel drum in such a manner that upon fast rotation of the reel drum during a lifting-up operation, a braking pawl attached to the reel drum is locked into a ratchet wheel secured on an end cap due to centrifugal force. The air balancing hoist includes a housing 102 with a chamber 101, which compressed air is introduced into and discharged from, formed therein and with end caps 104, 111 mounted on both ends of the housing, a piston 105 reciprocating along an inner periphery of the housing 102, a ball screw 106 installed in the housing 102 so that it penetrates the piston 105 and is secured to the end caps 104, 111 so as not to rotate, and a reel drum 110 with one end thereof rotatably supported by the piston 105 through a bearing 107 and with the other end thereof secured on a ball nut 108 rotatably engaged with the ball screw 106 so that the reel drum is rotated when moving along the ball screw 106.

Abstract: The present invention relates to a safety device for an air balancing hoist for braking and finally stopping a reel drum in such a manner that upon fast rotation of the reel drum during a lifting-up operation, a braking pawl attached to the reel drum is locked into a ratchet wheel secured on an end cap due to centrifugal force. The air balancing hoist includes a housing 102 with a chamber 101, which compressed air is introduced into and discharged from, formed therein and with end caps 104, 111 mounted on both ends of the housing, a piston 105 reciprocating along an inner periphery of the housing 102, a ball screw 106 installed in the housing 102 so that it penetrates the piston 105 and is secured to the end caps 104, 111 so as not to rotate, and a reel drum 110 with one end thereof rotatably supported by the piston 105 through a bearing 107 and with the other end thereof secured on a ball nut 108 rotatably engaged with the ball screw 106 so that the reel drum is rotated when moving along the ball screw 106.