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US 4,391,593 AGranted
Propulsion drive systems
OwnerEdward Whitworthinventor
Life of this patent
Estimating the term…
Abstract
A propulsion drive system for a boat is provided where a propeller is centered within a tunnel. A converging channel, open towards the bottom, extends in front of the tunnel and a converging nozzle extends from the rear of the tunnel. The system is provided with apparatus for mounting the propeller in the center of the tunnel widthwise and a suitable rudder is mounted to the rear of the converging nozzle. The propulsion drive system can operate quietly with little vibration and no cavitation.
Claims13
A propulsion drive system for a boat comprising:
- (a) a tunnel inset into the bottom of said boat commencing at the stern and extending a relatively short distance towards the bow, said tunnel being cylindrical in shape;
- (b) a channel in the bottom of said boat extending in front of said tunnel and gradually decreasing in size towards the bow until the channel disappears completely, said channel being open towards the bottom of the boat and having a cross-sectional area slightly larger than the outside diameter of the tunnel where the tunnel and the channel meet, said tunnel having a circular leading edge that is tapered throughout its circumference from an inner wall to an outer wall of said tunnel to allow for a smooth transition between the channel and the tunnel;
- (c) a shaft extending from a motor in said boat to a propeller centred widthwise in said tunnel near said stern, said propeller having a small diameter relative to the size of said tunnel, said shaft being enclosed in a suitable log;
- (d) means for mounting said log within the tunnel to maintain the propeller in the centre;
- (e) a converging nozzle mounted along the rear of a trailing edge of said tunnel;
- (f) a suitable rudder mounted to the rear of said converging nozzle;
- (g) said log containing water cooled bearings and holes or water passages in front of each of said bearings so that water from the location where the boat is being operated can come into contact with said bearings;
- (h) appropriate passages so that the motor is cooled from water passing through said holes in said log.
5 more elements
A propulsion drive system for a boat comprising:
- (a) a tunnel inset into the bottom of said boat commencing at the stern and extending a relatively short distance towards the bow, said tunnel being cylindrical in shape;
- (b) a channel in the bottom of said boat extending in front of said tunnel and gradually decreasing in size towards the bow until the channel disappears completely, said channel being open towards the bottom of the boat and having a cross-sectional area slightly larger than the outside diameter of the tunnel where the tunnel and the channel meet, said tunnel having a circular leading edge that is tapered throughout its circumference from an inner wall to an outer wall of said tunnel to allow for a smooth transition between the channel and the tunnel;
- (c) a shaft extending from a motor in said boat to a propeller centred widthwise in said tunnel near said stern, said propeller having a small diameter relative to the size of said tunnel, said shaft being enclosed in a suitable log;
- (d) means for mounting said log within the tunnel to maintain the propeller in the centre;
- (e) a converging nozzle mounted along the rear of a trailing edge of said tunnel;
- (f) a suitable rudder mounted to the rear of said converging nozzle;
- and
- (g) a diverging nozzle of semi-circular cross-section extending from an upper half of said converging nozzle rearwardly above said rudder.
5 more elements
Dependencies are inferred from the claim text.