Abstract: A crane has at least one telescopic crane arm with at least two sliding arms that are moveable against each other. At least one gliding element, which is housed loosely in a frame, is arranged between the sliding arms. The gliding element has a separate spring element projecting over the gliding surface of the gliding element.

Abstract: A multistage telescopic boom or jib, in particular for a loading crane on a truck, has hydraulic units each including a piston and a cylinder arranged between the successive, telescopically nested arms. A pipe projects axially from the bottom of the cylinder into the chamber of the cylinder, sealingly extending into the hollow piston rod when the piston is retracted and sealing the chamber of the cylinder from an inner chamber of the hollow piston rod. In order to ensure an automatic extension sequence of the telescopic arms, the inner chamber of each hollow piston rod is linked to the cylinder chamber of the next outer hydraulic unit by a preferably rigid line, and the inner chamber of each hollow piston rod communicates with the cylinder chamber of the same hydraulic unit when the piston is fully extended.

Abstract: A hydraulically extendable and retractable truck support or stabilizer jack is pivoted upwards about a vehicle-mounted trunnion or axis. A free end of the jack is hinged to a telescopic rod which can be retracted to a limited extent and which is mounted to pivot on a pivot element or swivel member which in turn pivots about a vehicle-mounted trunnion or axis in the direction of the jack until it reaches a vehicle-mounted stop.