Material feed control method and apparatus for a wood or brush chipping machine

A method of material feed control for a wood or brush chipping machine having a pair of coacting feed rolls for feeding material to be chipped into a rotating chipper driven by an engine of variable speed, comprising the steps of:

• (a) providing a pair of hydraulic motors, one of which is drivably attached to each of the feed rolls;
• (b) a hydraulic pump driven by the engine for supplying pressurized hydraulic fluid to drive said hydraulic motors;
• (c) actuating said hydraulic motors by opening of a valve means downstream of said hydraulic motors and interrupting said hydraulic motors by closing said valve means;
• and
• (d) opening said valve means when the pressure of said hydraulic fluid to said hydraulic motors is at least at a preselected high level and closing said valve means when said pressure is below a selected low level.

A material feed control mechanism for a wood or brush chipping machine having a pair of coacting feed rolls for feeding material to be chipped into a rotating chipper driven by an engine of variable speed, comprising:

• (a) a hydraulic pump for providing a supply of pressurized hydraulic fluid;
• (b) a hydraulic motor for driving each of the feed rolls;
• (c) a flow divider for directing an equal supply of said pressurized fluid to each of said hydraulic motors;
• (d) means for monitoring the speed of the engine;
• (e) first valve means operable by said speed monitoring means for interrupting the supply of said pressurized hydraulic fluid to said flow divider if the speed of the engine drops below a preselected limit;
• and
• (f) second valve means connected across said hydraulic motors and said flow divider for stopping the flow of hydraulic fluid through said hydraulic motors to brake the feed rolls when said supply of hydraulic fluid to said flow divider is interpreted.