Patent ID: 7210645

Claim:
A safety element retention system having a reel upon which a safety element may be wound, and released under normal operation, and may be instantly stopped under emergency operation, and a rewind mechanism, for rewinding the reel and retrieving the safety element, and further comprising; at least one locking plate, connected integrally with and fixed permanently to the reel, and rotatably moveable simultaneously and coextensively therewith as a single unit, both during normal and emergency operation; a plurality of hooks associated with said at least one locking plate; a plurality of ramp portions adjacent to respective said hooks; a locking assembly, defining at least one locking dog, adjacent to said hooks and ramp portions, the locking assembly being swingable about a pivot axis between a locking position and an unlocking position; a ramp follower connected to the locking assembly, being adapted to make contact with each of the hooks and ramp portions on the locking plate repeatedly in sequence as said locking plate rotates, and wherein each such contact causes the locking assembly in response to contact with each said hook to swing repeatedly into the locking position, bringing the locking dog into the path of each of the hooks on the locking plate in sequence, and wherein contact of said ramp follower with said ramp portions permits said locking assembly to swing into the unlocking position removing the locking dog out of the path of each hook on the locking plate, in sequence; a biasing spring device connected to the locking assembly to cause said ramp follower to contact said ramp portions, in sequence, thereby repeatedly swinging of the locking assembly, during normal operation, to remove the locking dog out of the path of each said hook in sequence as the locking plate rotates, and a mass damping device connected to said locking assembly for momentarily retarding movement thereof, during abrupt emergency operation whereby said mass damping device delays said biasing spring device and delays swinging movement of said locking assembly from said locking position to said unlocking position and thus causes said locking dog on said locking assembly to remain in the path of a hook on the locking plate and to engage said hook, and cause simultaneous stopping of said locking plate and said reel.