Abstract: An air ventilator for ventilating indoor air to the environment comprising a motor provided with a shaft, a rotor mounted on said shaft, a plurality of fan blades pivotally attached to the rotor, a rotating circular plate having a plurality of sliding slots and a plurality of connecting holes mounted on said shaft of the motor, a fixed circular plate connected to the rotating circular plate with pins and mounted on the shaft of said motor, centrifugal weight members disposed between the fixed circular plate and the rotating circular plate, and a torsion coil spring connecting the centrifugal weight member with the rotating circular plate for elastically supporting the weight member, whereby when the motor is operating, the centrifugal weight members engage the rotating circular plate, apply a circumferential directional force thereto, and angularly displace the circular plate, said displacement being transmitted to the fan blades for ventilating the inside air to the environment; and when the motor is not ope

Abstract: A boat is arranged to carry temporarily a vehicle (2), a driven wheel (7) of which is arranged to drive a propeller shaft (15) of the boat via contact rollers (9), and a belt drive (11), to propel the boat from the power of the vehicle engine. The boat may also be steered by means of a rudder which is connected to a movable cradle which engages and follows movement of the steerable front wheels of the vehicle.