Patent ID: 8215441

Claim:
A steering system for controlling the steering mode of a boat lifting apparatus comprising: a frame structure having a first front wheel proximate a front portion of a first side of the frame structure, a second front wheel proximate a front portion of a second side of the frame structure, a first rear wheel proximate a rear portion of the first side, and a second rear wheel proximate a rear portion on the second side, each wheel having an axle, wherein each wheel is configured to selectively turn about the respective axle in one of a first drive direction and a second, opposed drive direction to move the frame structure; a lifting assembly supported by the frame structure and adapted to engage and lift an object; a user interface for selecting a steering mode; a controller communicatively coupled to the user interface, the controller configured to control movement of the first and second front wheels and the first and second rear wheels in response to a selected steering mode, wherein in response to selection of a carousel steering mode, the controller is configured to cause the wheels to move to respective programmed angular positions for the carousel steering mode, and is further configured to cause the first front wheel and the first rear wheel to turn in the first drive direction and to cause the second front wheel and the second rear wheel to and turn in the second drive direction to cause the frame structure to turn in a carousel manner, and an engine connected to the frame structure, the engine capable of operation at a variety of different RPMs; and, a sensor coupled to the engine and the controller for providing the controller with an operating RPM of the engine, wherein if the operating RPM is lower than a predetermined amount, the controller adjusts the rate of change of the angular position of each wheel.