Patent ID: 6089786
Filing Date: 2000-07-18
Classification: E04F

Abstract:
For a self propelled finishing machine of the type comprising a frame, internal combustion engine means secured to said frame, a plurality of revolving, bladed, rotor assembles pivoted to said frame and driven by said engine means, a power steering system comprising:pump means driven by said internal combustion engine means for supplying hydraulic pressure;hydraulic circuit means powered by said pump means for operating the power steering system, said circuit means comprising:tilting cylinder means for tilting the rotor assemblies to effectuate trowel steering and maneuvering;proportional, pressure reducing valve means for controlling said tilting cylinder means; and,electric circuit means for selectively activating said valve means;left and right joysticks accessible to a trowel operator for operating said circuit means whereby the operator of the trowel can steer and control the riding trowel hydraulically; and,wherein the left and right joysticks move generally with the same mechanical hand-lever movements necessary for steering manual steering riding trowels thereby establishing backwards compatibility said electric circuit means comprises an electric field coil for selectively activating each proportional, pressure-reducing valve.