Compact excavator scoop movement control - involves two leads feeding different control pressures to valve unit holes

摘要

The machine is designed for use as an excavator. A boom holding unit is used with a boom swivel (3) and is used for generation of a first control pressure. There is a scoop-holding unit for the scoop (5) swivel. This generates a second control pressure. There is a control valve unit with two valve reversal control apertures. One lead conveys the first control pressure to one aperture, and another conveys the second control pressure to the other. The valve unit is attached to the scoop cylinders (8) in such a way that hydraulic oil can be carried away from their underside. The scoop can be automatically held in a predetermined setting when raised and easily returned to trenching position.