BOOM MACHINE WORKING IMPLEMENT GRAVITY BALANCING DEVICE (VARIANTS) Russian patent published in 2007 - IPC E02F9/22 

FIELD: boom earth-shifting, mining, construction and other cyclic handling machinery provided with wheels or caterpillars.

SUBSTANCE: balancing device comprises working implement, main hydraulic cylinder and balancing pneumohydrocylinder. The pneumohydrocylinder includes piston cavity communicated with gas cylinder. Device also has working liquid distribution means, hydraulic pump provided with parallel main hydraulic cylinder and pneumohydrocylinder installed in the hydraulic pump and brought together with respect to longitudinal axis of working implement symmetry. In accordance with the first embodiment working liquid distribution means is installed to alternately communicate working cavities of main hydraulic cylinders with hydraulic pump and with hydraulic reservoir inlet. In the second embodiment working liquid distribution means may connect working cavities of main hydraulic cylinder with each other and with hydraulic pump in the first slide position, wherein main hydraulic cylinder dimension ratio is selected to provide ratio of square of piston diameter to square of shaft diameter equal to 2. In accordance with the third embodiment main working liquid distribution means provides alternate communication of main hydraulic cylinder working cavities with hydraulic pump and with hydraulic reservoir inlet, wherein additional distribution means is installed to provide connection of working cavities of main hydraulic cylinder with each other and with hydraulic pump in the first slide position. In the forth embodiment main distribution means may connect working cavities of main hydraulic cylinder with each other and with hydraulic pump in the first slide position, as well as with each other and with hydraulic reservoir inlet in the second slide position, wherein additional distribution means is installed to connect shaft end of balancing pneumohydrocylinder with hydraulic reservoir inlet in the first slide position and with hydraulic pump in the second slide position.

EFFECT: simplified structure, extended range of functional capabilities and increased rate of working implement lifting and lowering.

5 cl, 7 dwg