Depth sensing structure for an agricultural implement

摘要

A soil-smoothing or leveling tool, such as a harrow or press wheel gang, is rockably connected to the rear of the main frame of a tillage or seeding implement. The tool frame width is substantial compared to the width of the implement, and the height of the tool frame relative to the main frame is sensed to provide an accurate indication of the average depth of penetration across the width of the implement. The angle-sensing device operably connected to the drawbar of the trailing tool senses the angle between the main frame and the drawbar, and a control valve assembly responsive to the sensed angle controls the main frame lift system to maintain a preselected relationship between the tool and the main frame and thereby accurately control tillage or planting depth.