Soil aerating apparatus with hydraulic valve arrangement
US4516638A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1983 |
| Grant date | May 14, 1985 |
| Priority date | — |
| Expiry date | May 25, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8671
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A soil aerating apparatus comprising a towing vehicle, a soil aerating device comprising a drum, tines extending radially from the drum, and a frame for supporting the drum for rotation about a horizontal axis. The frame includes a forward end with a draw arm, and the forward end is pivotally attached to the towing vehicle so that the frame is raised and lowered by moving the draw arm. The apparatus also includes a mechanism for moving the draw arm comprising a hydraulic cylinder including a piston rod and connected between the draw arm and the towing vehicle, and a valve operably connected to the cylinder for extending and retracting said piston rod. The valve includes a valve member movable between a position wherein the valve extends the piston rod, a position wherein the valve holds the piston rod in a fixed position, a position wherein the valve retracts the piston rod, and a position wherein the valve permits the piston rod to extend or retract in response to movement of the draw arm. The apparatus also includes a mechanism for moving the valve member. The mechanism includes a lever pivotally connected to the valve member and pivotally mounted for movement between four positi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.