| 摘要 |
A self-propelled concrete finishing trowel (20) has an improved power steering control system that steers the machine (20) by tilting the driven shaft(s) of the rotor assembly or assemblies (28,30) of the machine (20) without requiring the imposition of fatiguing actuating forces by the machine's operator. The steering control system includes at least one electric actuator, such as a ball screw actuator, coupled to each rotor assembly (28,30) of the machine (20) and controlled by an operator-manipulated controller (85). The controller (85) preferably includes at least one, and possibly two, joysticks that can be manipulated by the operator to steer the machine in the direction of joystick motion and preferably at a speed that is proportional to the magnitude of joystick movement. In the typical case in which the machine (20) is steered by pivoting a gearbox of at least one rotor assembly (28,30) about two axes, a separate actuator is provided for each axis of gearbox pivoting. The resultant machine (20) is easy to operate, lightweight, and exhibits little risk of high-pressure fluid spills. <IMAGE> |
