Abstract: A wood chipper includes a cutting assembly and a feed wheel for feeding material through an adjustable throat opening adjacent the feed wheel and toward the cutting assembly. A throat sensor measures the size of the throat opening and an electronic control unit (ECU) controls operation of the wood chipper in accordance with the size of the throat opening. The ECU controls forward, reverse and non-rotation of the feed wheel as well as down pressure applied by the feed wheel on feed material moving through the throat opening. The feed wheel down pressure may be constant or vary in any number of ways. One option includes applying down pressure in a pulsating manner.

Abstract: A wood chipper includes a control system for controlling feed wheel rotation and engine operation to provide safety features and a fuel-saving mechanism. The control system allows the engine to start only when the feed wheel is in neutral; stops and/or reverses rotation of the feed wheel in response to an increased load on the engine; and dethrottles the engine if the feed wheel remains in neutral for a predetermined period of time. A pair of electric switches are activatable by the feed bar whereby an electronic control unit (ECU) can determine the position of the feed bar based on activation or non-activation of the switches and control the feed wheel and engine in light thereof. The ECU controls a pair of directional control valves via respective solenoids to control flow of hydraulic fluid to control rotation of a feed motor which drives the feed wheel.