Patent ID: 6575318
Filing Date: 2003-06-10
Classification: B66C

Abstract:
In a hydraulically actuated telescopic jib of a crane having a jib box frame and a plurality of telescopic sections guided one section inside another, each of said plural telescopic sections having a driver bolt receptive opening and being moveable along a jib axis from a starting position into at least one extended position, and an actuating means for displacing said telescopic sections between the starting position and the at least one extended position, a locking device comprising:a locking unit fixedly connected to said actuating means; at least one driver bolt; a drive operatively arranged to displace said driver bolt transverse to said jib axis for introducing said at least one driver bolt into one of said driver bolt openings, said drive being mounted on said box frame; a coupling device arranged with said locking unit, said drive being operable to move said coupling device relative to said locking unit, each of said plural telescopic sections having at least one axially displaceable locking bolt receptive in a locking opening for fixing a section in a locking position for preventing displacement into one of another larger one of said plural telescopic sections and said box frame, said coupling device being operable to grip and pull said at least one locking bolt out of said locking opening, said drive being arranged fixedly on said box frame; and a mechanical drive connection between said drive and said locking unit.