Abstract: A self-centering boom for self-propelled agricultural sprayers having a double-acting hydraulic cylinder and a magnetically actuated electrical position sensor and control for sensing and moving the boom to a centered position. The electro-hydraulic control circuit senses boom position when the boom is at or near a centered position with respect to the sprayer and automatically centers the boom when the sprayer drive train is out of a neutral condition. The hydraulic system includes a pair of pressure relief valves to allow the boom to deflect due to inertial forces when turning or when contact is made with an obstruction, with the control system returning the boom to a centered position after turning or when the boom is clear of the obstruction. A flow restricting orifice cooperates with the pressure relief valves to automatically adjust the pressure at the inlet of the relief valve to retard rapid boom movement, while not interfering with slow boom movement.

Abstract: A self-centering boom for self-propelled agricultural sprayers having a double-acting hydraulic cylinder and a magnetically actuated electrical position sensor and control for sensing and moving the boom to a centered position. The electro-hydraulic control circuit senses boom position when the boom is at or near a centered position with respect to the sprayer and automatically centers the boom when the sprayer drive train is out of a neutral condition. The hydraulic system includes a pair of pressure relief valves to allow the boom to deflect due to inertial forces when turning or when contact is made with an obstruction, with the control system returning the boom to a centered position after turning or when the boom is clear of the obstruction. A flow restricting orifice cooperates with the pressure relief valves to automatically adjust the pressure at the inlet of the relief valve to retard rapid boom movement, while not interfering with slow boom movement.