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The stump grinder has a rotating cutting wheel that is mounted onto an arm for raising and lowering movement and is driven by a hydraulic motor. The arm is capable of being moved about a generally upright axis to control the rate of laterally feed of the cutting wheel. The actuator movement is contr

The stump grinder has a rotating cutting wheel that is mounted onto an arm for raising and lowering movement and is driven by a hydraulic motor. The arm is capable of being moved about a generally upright axis to control the rate of laterally feed of the cutting wheel. The actuator movement is controlled as a function of the pressure to the hydraulic motor driving the cutting wheel so that as the pressure increases, the rate of feeding movement laterally of the cutting wheel is reduced. The rate of movement is controlled in both directions of swinging of the post about an upright axis, by utilizing variable opening or proportional flow pilot operated valves on the lines to the actuator for controlling the swing. As pressure to the motor increases the variable outlet or proportional pilot operated valve connected to the pressurized end of the swing actuator opens a greater amount diverts a portion of the hydraulic fluid flow to drain to slow movement of the swing actuator.

대표청구항 ▼

1. A rotating wheel grinder driven by hydraulic power including a housing for mounting the rotating wheel, a hydraulic motor for driving the wheel in a rotational direction, said motor having a pressure side and a return side, a swinging mount for supporting the wheel for movement about a swing axis

1. A rotating wheel grinder driven by hydraulic power including a housing for mounting the rotating wheel, a hydraulic motor for driving the wheel in a rotational direction, said motor having a pressure side and a return side, a swinging mount for supporting the wheel for movement about a swing axis, and a hydraulic swing actuator for controlling movement of the swinging mount, and a variable flow valve for controlling flow to a pressure side of the actuator as a function of the pressure on the pressure side of the motor wherein the valve for controlling flow is a pilot operated proportional valve that adjustably connects the pressure side of the actuator to drain as a function of the pilot pressure.