US 5,199,913 AGranted

Small, jet-propelled boat

AssigneeSanshin Kogyo Kabushiki Kaisha

InventorsMakoto Toyohara, Hiroshi Tasaki

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Abstract

A jet-propelled craft includes a hull, an engine installed within the hull, a duct positioned in the stern area of said hull, and an impeller which is turned by the rotational force of the engine to create a jet stream within the duct. The craft also includes left and right secondary water-intake openings on the bottom of the hull which are positioned a specific distance apart on the left and right in the hull, the duct including branches connected to the left and right secondary water-intake openings. By equipping the secondary water-intake openings with a valve which closes when a sharp turn is made in the above mentioned boat and the valve is on the outside with respect to the direction of the turn, air is prevented from entering the outside secondary duct and a loss of propulsive force is prevented.

Claims15

Dependent claims

A jet-propelled boat including a hull, a bottom side of which is under water when operating the boat, a main duct positioned in the hull, impeller means within the main duct for creating a jet stream within the main duct, and first and second water-intake openings on the bottom of the hull positioned a predetermined distance apart on opposite sides of the hull and connected by respective duct branches to the main duct;

means including valves positioned to selectively open and close each of the first and second water-intake openings;
and
means for controlling said valves to close one of said first and second openings when a turn is made in said boat such that said one of said openings which is positioned on the outside of said boat with respect to a direction of the turn is always closed to thereby prevent air from entering said one of said openings when it is exposed to the air during the turn so that only the opening which is positioned on the inside of said boat with respect to the direction of the turn will be open.

Dependencies are inferred from the claim text.