Front loader

摘要

The front loader contains a portal (2) on a travelling mechanism (1), a boom (3) which is fastened to the portal (2), a shovel (4) fastened to the boom (3), and a hydraulic system for controlling the loader. The hydraulic system comprises hydraulic cylinders (5, 6, 7, 8) for swivelling the boom (3) and the shovel (4), a main directional control valve (9) connected to the hydraulic cylinders (5, 6, 7, 8), a pump (13) and an operating-fluid tank (12), and also an additional three-position directional control valve (11), the housing of which is attached to the portal (2) and the control spool (11') of which is kinematically connected to the boom (3). The additional directional control valve (11) is provided with a non-return valve (30), while the kinematic connection between the control spool (11') and the boom (3) is made by means of at least one three-position change-over switch (10). <IMAGE>