MANUALLY CONTROLLED LIFTING DEVICE WITH A PNEUMATIC LIFT DRIVE MECHANISM

摘要

The invention relate to a manually controlled lifting device with a pneumatic lift drive mechanism (1), a lifting organ (5, 13) connected thereto, load receiving means (6) arranged on the end of the lifting organ and a pneumatic switch (9) that is integrated into a pressure line (7) connecting a compressed air source (8) to a pressure chamber (3) of the lift drive mechanism (1) and connecting the pressure chamber (3) of the lift drive mechanism (1) to the compressed air source (8) in one position (1) and to a ventilation device (11) in another position (H). A flow-through control device (10) located in the load flow is integrated in-between both load-transmitting components (5-5; 13-14). Said device is simultaneously connected between the pneumatic switch (9) and the pressure chamber (3) of the lift drive mechanism (1) in the compressed air line (7). Said device automatically varies the through-flow cross section of the compressed air line (7) under the influence of the load engaged in the load receiving means (6) in such a way that a) the through-flow cross section during a lifting operation with a heavy load is larger than when the load is lighter and b) the through-flow cross section during a lowering operation with a heavy load is smaller than when the load is lighter.