| 摘要 |
A means at a first piston (1) with two active surfaces (1a, 1b) included in a bogie hoist or similar for movement by means of a pressurized driving medium (10) in two mutually opposite directions. The one active surface (1a) of the first piston (1) is elaborated larger than the other active surface (1b) of the first piston (1). A valve (4) is connected directly between the two active surfaces (1a, 1b) of the first piston (1). The said valve (4) in relation to a given differential pressure is arranged to open and close a channel (3) directly between the said active piston surfaces (1a, 1b). A shut-off valve (5) is also included, which in association with the one turning position of the movement of the first piston (1) is arranged to close the said channel (3). |
