| 摘要 |
PCT No. PCT/FR98/00172 Sec. 371 Date Oct. 5, 1998 Sec. 102(e) Date Oct. 5, 1998 PCT Filed Jan. 30, 1998 PCT Pub. No. WO98/33371 PCT Pub. Date Aug. 6, 1998A method and device for automatically adjusting the lightening of a working unit (U) of a machine by use of a hydraulic ram (57) associated with a hydropneumatic accumulator (67). Use is made of a second hydraulic ram (58) of which the piston (53), which can move as far as a predetermined position (PP) in the cylinder (C2) and which is detached from the rod (46) of the first hydraulic ram (57), acts directly or indirectly on the latter rod via the oil (O) contained in the first hydraulic ram (57). The working unit (U) is raised and lowered by the second hydraulic ram (58). When raising the working unit (U), the volume of oil in the first hydraulic ram (57) is increased or decreased in such a way that the working unit (U) is always at a predetermined height (HP) at the end of raising travel. |
