Patent ID: 8505143

Claim:
A programmable steerable robot for cleaning swimming pools and the like, comprising: a body member; a first ground-engaging rotary propelling device at one side of the body member; a second ground-engaging rotary propelling device at an opposite side of the body member; a drive for driving both of said rotary propelling devices; a transmission system coupling said drive to both of said rotary propelling devices; and a programming device controlling said transmission system such that, for selected time intervals, both rotary propelling devices are driven in the same direction, and for other time intervals, said rotary propelling devices are driven in opposite directions; said transmission system including: a first shaft coupled with said drive for being driven synchronously with the driving of the first ground-engaging rotary propelling device, the first shaft having thereon a first gear and at a distance spaced apart from the first gear, having thereon a second gear; a second shaft that is in a parallel orientation with the first shaft, the second shaft having thereon a third gear that is aligned so as to be engaged with the first gear and thereby cause rotation of said third gear in a direction that is opposite to the rotational direction of said first and second gears, and at a distance spaced apart from the third gear, having thereon a fourth gear which is also caused by said third gear to also rotate in said opposite direction; where the diameter of the first and third gears is larger than the diameter of the second and fourth gears, so that a space is formed between the second and fourth gears; and a third shaft coupled for driving the second ground-engaging rotary propelling device, the third shaft having thereon a fifth gear, the fifth gear being selectably positionable by the programming device to so as to engage one of the second and fourth gears for selected time intervals for causing both rotary propelling devices to be driven in the same direction, and for other time intervals the fifth gear being positionable by the programming device so as to engage an other one of the second and fourth gears for causing the rotary propelling devices to be driven in opposite directions.