BULLDOZER Russian patent published in 1999 - IPC

FIELD: earth-moving machinery and equipment. SUBSTANCE: bulldozer has base carrier, mounted attachment including main mouldboard, additional mouldboard, pushing beams, hydraulic system with control devices and hydraulic actuating members. To prevent interaction between main mouldboard and additional mouldboard, pushing beams of additional mouldboard are made in the form of H-shaped frame which is pivotally connected with frame of base carrier and hydraulic drive of additional mouldboard. Main hydraulic control unit is made in the form of three-position hydraulic control valve connected by hydraulic lines with hydraulic cylinders of mouldboards through intermediate control valves. Main hydraulic control valve is also connected with hydraulic drives of mouldboards through "OR" valves. Hydraulic line which connects three-position main hydraulic control valve with hydraulic cylinder of additional mouldboard control valve can be provided with adjustable throttle valve. Aforesaid embodiment of bulldozer working attachment simplifies operator's work and enhances productivity. EFFECT: higher efficiency. 2 cl, 3 dwg