主权项 |
1. A stump grinder, which comprises:
(a) a frame that is supported for movement over the ground; (b) a rotatable grinding wheel that rotates about a substantially horizontal axis for grinding or comminuting stumps or wood debris; (c) a grinding arm that is movable relative to the frame and that mounts the grinding wheel, wherein the grinding arm is pivotal about substantially horizontal and vertical axes to cause the grinding arm to pivot up and down about the horizontal axis and from side-to-side about the vertical axis; and (d) a single joystick for controlling the up and down and side-to-side pivoting of the grinding arm, wherein the joystick is carried on the frame for manipulation by an operator along first and second orthogonal axes that are correlated to desired directions of pivoting of the grinding arm, the joystick being pulled rearwardly out of a neutral position in a fore-and-aft direction to lift the grinding arm, being pushed forwardly out of a neutral position in a fore-and-aft direction to lower the grinding arm, being pulled to the right out of a neutral position in a side-to-side direction to swing the grinding arm to the right, and being pulled to the left out of a neutral position in a side-to-side direction to swing the grinding arm to the left. |