Hydraulic system for a towed implement
US5348101A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 1993 |
| Grant date | Sep 20, 1994 |
| Priority date | — |
| Expiry date | Jan 8, 2013 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01B63/22
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A hydraulic rockshaft control circuit which includes a three-way valve that normally operates the rockshaft is connected to the lift cylinder on a trailing implement. A hitch lock valve connected to the rockshaft control valve maintains the rockshaft in a preselected position regardless of changes in pressure at the valve output. The extend side of the lift cylinder is connected to the control valve output so that the tractor hitch control is used to operate the trailing implement cylinder. To overcome the inability of the three-way valve to positively retract the trailing implement cylinder, a reducing/relieving valve is connected to the retract side of the cylinder and is adjusted to provide just enough pressure to retract the cylinder and raise the implement wheels from ground contact when the extend side is connected to return pressure. A position feedback system on the implement is connected to the hitch control unit (HCU) on the tractor. When the HCU senses a feedback signal from the implement, the HCU control mode changes from rockshaft control to trailing implement control wherein implement position is set and maintained in a manner similar to that for the conventional rock…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.