Back to results
US 6,749,035 B2Granted
Pitch alleviation system
AssigneeCase Corporation
InventorJohn E. Bundy
Life of this patent
Estimating the term…
Abstract
A hitch control system for a work vehicle combines a front suspension position signal, a hitch load signal and a hitch position signal to generate a valve command signal that controls hitch position so as to alleviate pitching and maximize front wheel ground contact time.
Claims16
A tractor having a ride control system that alleviates tractor pitching, comprising:
- a chassis;
- an engine mounted on the chassis;
- a hydraulic pump coupled to and driven by the engine to provide a flow of pressurized hydraulic fluid;
- a front suspension including two front wheels disposed on opposing sides of the chassis and supported by at least one front suspension hydraulic actuator configured to raise and lower the two front wheels with respect to the chassis;
- a front suspension sensor coupled to the front suspension to generate a signal indicative of the position of the front suspension with respect to the chassis;
- two rear wheels coupled to the chassis to rotate with respect thereto and drive the tractor over the ground;
- a multi-point hitch coupled to the rear of the chassis and configured to be coupled to an overhanging load extending from the rear of the chassis;
- a hitch position sensor coupled to the hitch to provide a signal indicative of an elevation of the hitch with respect to the chassis;
- a hitch hydraulic actuator coupled to the hitch to raise and lower the hitch with respect to the chassis;
- a load sensor coupled to the chassis to provide a signal indicative of a load on the hitch;
- at least one electrically actuated hitch control valve coupled to and between the pump and the hitch hydraulic actuator to regulate the flow of pressurized hydraulic fluid to the hitch hydraulic actuator;
- an electronic control circuit coupled to and responsive to the front suspension sensor, the load sensor, the hitch position sensor, and the hitch control valve to control the flow of pressurized hydraulic fluid to the hitch hydraulic actuator in real time to alleviate tractor pitching.
9 more elements
A method of electronically reducing pitching in a tractor, comprising the steps of:
- (a) receiving an electrical signal from a front suspension sensor indicating the position of a front suspension;
- (b) receiving an electrical signal from a hitch position sensor indicating the height of a hitch with respect to a chassis;
- (c) receiving an electrical signal from a load sensor indicative of a load experienced by the hitch;
- (d) combining the front suspension sensor signal, the hitch position sensor signal and the load sensor signal;
- (e) generating a hitch hydraulic actuator signal calculated to drive the hitch upward or downward with respect to the chassis;
- and
- (f) driving the hitch upward or downward with respect to the chassis to thereby reduce tractor pitching.
4 more elements
A work vehicle having a ride control system that alleviates vehicle pitching, comprising:
- a chassis;
- an engine mounted on the chassis;
- a hydraulic pump coupled to and driven by the engine to provide a flow of pressurized hydraulic fluid;
- a front suspension including two front wheels disposed on opposing sides of the chassis and supported by at least one front suspension hydraulic actuator configured to raise and lower the two front wheels with respect to the chassis;
- a front suspension sensor coupled to the front suspension to generate a signal indicative of the position of the front suspension with respect to the chassis;
- two rear wheels coupled to the chassis to rotate with respect thereto and drive the vehicle over the ground;
- a hitch coupled to the rear of the chassis and configured to be coupled to an overhanging load extending from the chassis;
- a hitch position sensor coupled to the hitch to provide a signal indicative of an elevation of the hitch with respect to the chassis;
- a hitch hydraulic actuator coupled to the hitch to raise and lower the hitch with respect to the chassis;
- a load sensor coupled to the chassis to provide a signal indicative of a load on the hitch;
- at least one electrically actuated hitch control valve coupled to and between the pump and the hitch hydraulic actuator to regulate the flow of pressurized hydraulic fluid to the hitch hydraulic actuator;
- an electronic control circuit coupled to and responsive to the front suspension sensor, the load sensor, the hitch position sensor, and the hitch control valve to control the flow of pressurized hydraulic fluid to the hitch hydraulic actuator in real time to alleviate vehicle pitching.
9 more elements
Dependencies are inferred from the claim text.