Locking cylinder for telescopic jib - has first cylinder-stage acted upon by first spring in direction of extended locking positioning to lock telescopic cylinder relative to first jib position

摘要

The first cylinder stage (21) is acted upon by a first spring (34) in the direction of an extended locking positioning to lock the telescopic cylinder (25) relative to a first jib position (50). The first cylinder stage has a pressure medium supply line (39) for force development in a direction opposite to the force development of the first spring. The second cylinder stage (22) is acted upon by a second spring (44) in the direction of a retracted control positioning to provide locking between the first jib position and a second jib position. The second cylinder stage has a pressure medium supply line (32,41) for force development in a direction opposite the force development of the second spring.