초록 ▼

A high performance, twin rotor riding trowel for finishing concrete and hydraulic circuitry therefor, enabling complete joystick control to the operator. The rigid trowel frame mounts two spaced-apart, downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The

A high performance, twin rotor riding trowel for finishing concrete and hydraulic circuitry therefor, enabling complete joystick control to the operator. The rigid trowel frame mounts two spaced-apart, downwardly-projecting, bladed rotor assemblies that frictionally engage the concrete surface. The rotor assembly blades finish the surface while supporting the trowel. The rotor assemblies are tilted with double acting, hydraulic cylinders to effectuate steering and control. Double acting hydraulic cylinders also control blade pitch. A joystick system enables the operator to hand control the trowel with minimal physical exertion. The joystick system activates electrical circuitry that fires solenoid control valves that in turn energize the various hydraulic cylinders that tilt the rotors and alter blade pitch. The hydraulic control circuitry comprises a motor driven pump delivering pressure to a flow divider circuit. A bypass-valve in line before the flow divider enables an operator to customize the trowel steering characteristics.

대표청구항 ▼

[ What is claimed is:] [23.] A motorized, twin-rotor riding trowel for finishing a concrete surface, said riding trowel comprising:a rigid frame;internal combustion motor means for powering said trowel;hydraulic pump means driven by said motor means for supplying hydraulic pressure;a pair of spaced-

[ What is claimed is:] [23.] A motorized, twin-rotor riding trowel for finishing a concrete surface, said riding trowel comprising:a rigid frame;internal combustion motor means for powering said trowel;hydraulic pump means driven by said motor means for supplying hydraulic pressure;a pair of spaced-apart rotors pivotally suspended from said frame for supporting and propelling said riding trowel and finishing said concrete, each rotor comprising a plurality of radially spaced apart blades for frictionally contacting the concrete;hydraulic circuit means powered by said pump means for power steering the trowel, said circuit means comprising:tilting cylinder means for tilting the rotors to effectuate trowel steering and maneuvering;valve means for controlling said tilting cylinder means; and,electric circuit means for controlling said valve means;left and right joysticks accessible to a trowel operator for operating said electric circuit means whereby the operator of the trowel can steer and control the riding trowel hydraulically;operator adjustable flow valve means for bypassing fluid prior to delivery to said hydraulic circuit means to facilitate custom operator adjustments to trowel steering and control; 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.