US 6,698,523 B2Granted

Electrohydraulic control system for implement lift cylinders

AssigneeHUSCO International, Inc.

InventorDennis R. Barber

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Abstract

Different sections of an agricultural implement can be raised and lowered independently and by varying amounts by a unique hydraulic system. That system incorporates a three-position, four-way primary control valve which selectively connects a supply line and a tank return line to first and second hydraulic lines. A plurality of double acting hydraulic cylinders are provided to produce movement of lift assemblies with respect to a frame of the implement. A separate electrohydraulic lift control valve for each hydraulic cylinder couples one cylinder chamber to the first hydraulic line and the other cylinder chamber is connected directly to the second hydraulic line. Operation of the primary control valve determines the movement direction and selective activation of the lift control valves determines whether the associated section of the implement moves and the amount of such movement.

Claims9

Dependent claims

In an agricultural implement having a frame supported by a plurality of movable lift assemblies for raising and lowering the frame relative to the ground, a lift control system for controlling flow of pressurized hydraulic fluid from a supply line and flow of hydraulic fluid into a tank return line, said lift control system comprising:

a first hydraulic line and a second hydraulic line;
a primary control valve which selectively connects the first hydraulic line and the second hydraulic line to the supply line and the tank return line;
a plurality of hydraulic cylinders, each mechanically coupled to the agricultural implement to produce movement of a different one of the plurality of vertically movable lift assemblies with respect to the frame, each of the plurality of hydraulic cylinders having a first port and a second port;
the plurality of hydraulic cylinders hydraulically connected in a series between the first hydraulic line and the second hydraulic line, wherein a first hydraulic cylinder in the series has a first port connected directly to the first hydraulic line, each hydraulic cylinder, except for a last hydraulic cylinder in the series, has its second port connected to a next hydraulic cylinder in the series, and the last hydraulic cylinder in the series has its second port connected to the second hydraulic line;
and
a plurality of two-position lift controls valves, each connected between the first and second ports of one of the plurality of hydraulic cylinders.

3 more elements

In an implement having a frame supported by a plurality of movable lift assemblies for raising and lowering the frame relative to the ground, a lift control system for controlling flow of pressurized hydraulic fluid from a supply line and flow of hydraulic fluid into a tank return line, said lift control system comprising:

a first hydraulic line and a second hydraulic line;
a primary control valve having a first position in which the first hydraulic line is connected to the supply line and the second hydraulic line is connected to the tank return line, a second position in which the first hydraulic line is connected to the tank return line and the second hydraulic line is connected to the supply line, and a third position in which the first hydraulic line and the second hydraulic line are isolated from the supply line and the tank return line;
a plurality of hydraulic cylinders, each mechanically coupled to the agricultural implement to produce movement of a different one of the plurality of vertically movable lift assemblies with respect to the frame, each of the plurality of hydraulic cylinders having a first port and a second port, the plurality of hydraulic cylinders hydraulically connected in a series between the first hydraulic line and the second hydraulic line, wherein a first hydraulic cylinder in the series has a first port connected directly to the first hydraulic line, each hydraulic cylinder, except for a last hydraulic cylinder in the series, has its second port connected to a next hydraulic cylinder in the series, and the last hydraulic cylinder in the series has its second port connected to the second hydraulic line;
and
a plurality of two-position lift control valves, each connected between the first and second ports of one of the plurality of hydraulic cylinders.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/189,110Filed 2 Jul 2002
Published: US 2004/0016556 A129 Jan 2004
Granted: 2 Mar 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

A01B 63/22
With wheels adjustable relatively to the frame: operated by hydraulic or pneumatic means
F15B 11/20
With two or more servomotors: controlling several interacting or sequentially-operating members
F15B 21/082
Servomotor systems incorporating electrically operated control means: with different modes
A01B
Soil working in agriculture or forestry