Patent ID: 8132984

Claim:
A powered rotary trowel comprising: a frame that supports an engine and an operator; at least one rotor assembly that is driven by the engine; and a power steering system that includes: a manually manipulated steering command signal generator; an actuator configured to tilt at least a portion of the rotor assembly to steer the trowel; a control system that supplies power to the actuator, the control system being switchable by the operator to select one of a plurality of preset steering modes each of which associates a different set of steering responses to a range of steering command signal generator actuation; a mode selector operable by the operator to select one of the preset steering modes; wherein the steering modes include first and second preset steering modes, the first preset steering mode being defined by greater translation of the actuator than the second preset steering mode through at least a portion of the range of steering command signal generator actuation; and wherein a response curve plotting actuator response to translation of at least one of the steering command signal generators for the second preset mode is non-linear and diverges away from the corresponding response curve for the first preset mode for a first portion of steering command signal generator translation within the range and converges towards the corresponding response curve for the first preset configuration for a second portion of steering command signal generator translation within the range.