Patent Number: 6,167,685

Title: Windrower header speed control

Abstract: A system for controlling the header speed of a windrower to a set point includes a variable displacement pump producing a variable outflow of hydraulic fluid for driving the header via two hydraulic motors, the system being characterized in that the pump is driven by a pulse width modulated (PWM) signal having a duty cycle that is dependent on the speed and the acceleration of the header. When the header speed falls outside a window or range of speeds centered at the set point, header speed is used to modify the duty cycle of the PWM signal and bring the header speed back within the window. In addition, the duty cycle of the PWM signal is decremented if the acceleration of the header exceeds a threshold and the header includes disk type cutters.

Inventors: Berger; John G. (Landisville, PA), Bulgrien; Garth H. (Ephrata, PA)

Assignee: New Holland North America, Inc.

International Classification: A01D 34/00 (20060101); A01D 41/00 (20060101); A01D 41/14 (20060101); A01D 069/06 ()

Expiration Date: 01/02/2018