US 6,382,326 B1 · Implement suspension with accumulator

Abstract

An implement frame supported by hydraulically controlled lift wheels includes accumulator structure which is selectively connectable by valve structure to the lift cylinder circuit to control flow between the cylinder and accumulator according to implement status. For transport, the valve structure is opened for absorption of shock loads as the lift wheels move over obstructions and surface irregularities. For working in the field, the valve structure is closed to provide stable lift and precise depth control functions. The valve structure can be operated manually or automatically in response to vertical frame movement. In one embodiment, proportional valves are connected to an implement control unit for active suspension control which varies with changing transport conditions. A similar accumulator structure is provided for the hitch weight transfer system.

Claims25

Dependent claims

In an agricultural implement having a frame adapted for towing by a vehicle, tools connected to the frame, a lift wheel assembly supporting the implement for movement over the ground, the lift wheel assembly including an extensible and retractable hydraulic cylinder, hydraulic control structure connected to a source of hydraulic fluid under pressure and to the cylinder for selectively raising and lowering the frame between transport and field working positions and for adjusting the tools relative to the ground when the frame is in the field working position, suspension structure for cushioning the implement in the transport position comprising:

an accumulator;
and
control valve structure connected between the accumulator and the cylinder, wherein the control valve structure is movable between a closed position preventing fluid communication between the cylinder and the accumulator to facilitate accurate tool adjustment with the hydraulic control structure when the frame is in the field working position, and an open position providing fluid communication between the cylinder and the accumulator to facilitate cushioned implement support when the implement is in the transport position.

In an agricultural implement having a frame adapted for towing by a vehicle, tools connected to the frame, a lift wheel assembly supporting the implement for movement over the ground, the lift wheel assembly including an extensible and retractable hydraulic cylinder having base and rod ends, hydraulic control structure connected to a source of hydraulic fluid under pressure and to the cylinder for selectively raising and lowering the frame between transport and field working positions and for adjusting the tools relative to the ground when the frame is in the field working position, suspension structure for cushioning the implement in the transport position comprising:

accumulator structure;
control valve structure connecting the accumulator structure to the cylinder, wherein the control valve structure is movable between a blocking condition substantially preventing fluid communication between the cylinder and the accumulator structure to facilitate accurate tool adjustment with the hydraulic control structure when the frame is in the field working position, and an open condition providing fluid communication between the cylinder and the accumulator to facilitate cushioned implement support when the implement is in the transport position;
and
means responsive to the raising and lowering of the frame for moving the control valve structure between the blocking and open positions to provide cushioned support of the implement during transport and rigid support of the implement during field working operations.

1 more element

Dependencies are inferred from the claim text.

Implement suspension with accumulator

Life of this patent

Implement suspension with accumulator

Life of this patent

Abstract

Claims25