Patent ID: 6196327
Filing Date: 2001-03-06
Classification: A01B

Abstract:
A system for reducing the pitching of a tractor having a hitch, comprising:an agricultural tractor;a hitch coupled to the tractor and couplable to an implement and further disposed to raise and lower the implement with respect to the tractor;a force transducer disposed to provide a force signal indicative of a force applied to the hitch by the implement couplable to the tractor;a position transducer disposed to provide a position signal indicative of a position of the hitch with respect to the tractor;a hydraulic actuator disposed between the tractor and the hitch to raise and lower the hitch;a control valve disposed to control a flow rate of hydraulic fluid to and from the hydraulic actuator in response to a pitch-reducing control valve signal; anda control circuit coupled to and responsive to the force and position transducers to generate the valve signal, wherein the control circuit is configured to receive the force signal and derive the pitch-reducing control valve signal therefrom and apply it to the control valve and to attenuate the pitch-reducing control valve signal by one of a plurality of attenuation factors when the position signal passes a predetermined limit.