Patent ID: 6217105
Filing Date: 2001-04-17
Classification: E05Y,F15B

Abstract:
A hydraulic assembly for moving a movable part of a vehicle relative to the vehicle, said hydraulic assembly comprising:a working cylinder which is connected between the movable part and the vehicle includes a cylinder and a piston having a rod, said piston being movable within the cylinder so as to define a piston chamber and a rod chamber within said cylinder, anda hydraulic system connected to said working cylinder, said hydraulic system comprising:a tank for containing hydraulic medium,a first hydraulic line connected between said piston chamber and said tank, said first hydraulic line containing a first check valve,a second hydraulic line connected between said rod chamber and said tank, said second hydraulic line containing a second check valve,release means connected to said first and second check valves for mutual release,a third hydraulic line connected to said first hydraulic line at a location between said piston chamber and said first check valve and extending to said tank, said third hydraulic line containing a first pre-stress valve,a fourth hydraulic line connected to said second hydraulic line at a location between said rod chamber and said second check valve and extending to said tank, said fourth hydraulic line containing a second pre-stress valve,a switchable hydraulic pressure means connected to both said first and second hydraulic lines between said respective first and second check valves and said tank, anda fifth hydraulic line connected to one of said first and second hydraulic lines, said fifth hydraulic line including a one-way check valve which allows hydraulic medium to be suctioned therethrough from said tank to said working cylinder.