Abstract: The present invention relates to a mobile handling device with a hydraulic circuit, which hydraulic circuit (L) comprises a lifting cylinder (1) arranged in a lifting device (100) suitable for handling a variable load and an accumulator (6) for recovering or recycling lowering load energy, the hydraulic circuit also comprising a variable hydraulic machine (3) with two ports (10, 11), which hydraulic machine is capable via a drice unit (D) of emitting full system pressure in two flow directions to said ports, one port (11) being connected to said accumulator (6) and the other port being connected to said lifting cylinder (1).

Abstract: The present invention relates to a hydraulically powered arm system with a hydraulic circuit, which hydraulic circuit (L) comprises a pressure source (6) and a lifting cylinder (1) arranged to an arm which is intended for handling a tool, said hydraulic circuit (L) comprising a partial circuit (45A, 45B), which can be connected into communication with said pressure cource (6) by means of a first valve element (44) and said lifting cyliner (1) by means of a second valve element (43), characterised in that said partial circuit (45A, 45B) comprises a pressure reducing/relieving unit (4) whichis arranged between said valve elements (43, 44), and that said pressure reducing/relieving unit (4) is controlled by a pressure controlling unit (62A) in order to facilitate float control of the tool attached to the arm system, whereby a controlled ground pressure is obtained during the a floating motion.

Abstract: The present invention relates to a mobile handling device with a hydraulic circuit, which hydraulic circuit (L) comprises a lifting cylinder (1) arranged in a lifting device (100) suitable for handling a variable load and an accumulator (6) for recovering or recycling lowering load energy, the hydraulic circuit also comprising a variable hydraulic machine (3) with two ports (10, 11), which hydraulic machine is capable via a drice unit (D) of emitting full system pressure in two flow directions to said ports, one port (11) being connected to said accumulator (6) and the other port being connected to said lifting cylinder (1).