Down force adjustment and lift for an opener supported from a frame by lift arms
US5163518A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 21, 1991 |
| Grant date | Nov 17, 1992 |
| Priority date | — |
| Expiry date | Aug 21, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01C7/205
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A plurality of parallel arm type openers are mounted on a frame tube, and a rockshaft is supported directly below the tube. Adjacent each of the openers, a lever arm is fixed for rotation with the rockshaft and, upon rotation of the rockshaft in a first direction, the lever arm engages the parallel arms to lift the opener while the frame tube remains stationary in the vertical direction. A tension spring assembly connected between the parallel arms and the lever arm applies varying down force when the opener is lowered by rotating the rockshaft in the opposite direction. The amount of down pressure can be adjusted for varying conditions by rotation of the rockshaft, and adjustment can be made on-the-go from the tractor cab to compensate for changing ground conditions in a given field. Locking structure on the row units permits selective lock-up of row units with a single cycle of the hydraulic lift system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.