Siphon inhibiting device for a marine cooling system

A siphon inhibiting valve for a marine propulsion system, comprising:

• a housing structure comprising a first portion and a second portion and having an inlet port and an outlet port;
• a buoyant member disposed for movement along a first axis within said housing structure, said buoyant member having a generally blunt face at an end of said buoyant member most proximate said inlet port, said buoyant member being inhibited from rotating about a second axis which is perpendicular to said first axis whereby said generally blunt face is maintained in a position facing said inlet port, said buoyant member comprising a tapered portion extending with an increasing width from said generally blunt face;
• a guide member disposed within said housing structure and having an opening formed therein which is shaped to receive said buoyant member in sliding relation therein;
• and
• a sealing surface of said buoyant member which is movable into contact with said housing structure proximate said inlet port to prevent a liquid from flowing in a direction from said outlet port through said inlet port, said housing structure being connected in fluid communication with a cooling system of a marine propulsion system with said inlet port being disposed upstream from said outlet port within said cooling system to receive cooling water from a body of water and said outlet port being disposed downstream from said inlet port within said cooling system to conduct water to a cooling system of an engine of said marine propulsion system.

A siphon inhibiting valve for a marine propulsion system, comprising:

• a housing structure comprising a first portion and a second portion and having an inlet port and an outlet port;
• a buoyant member disposed for movement along a first axis within said housing structure, said buoyant member being rotatable about said first axis, said buoyant member having a generally blunt face at an end of said buoyant member most proximate said inlet port, said buoyant member being inhibited from rotating about a second axis which is perpendicular to said first axis whereby said generally blunt face is maintained in a position facing said inlet port, said buoyant member comprising a frustum of a cone portion extending with an increasing width from said generally blunt face, said buoyant member comprising a generally cylindrical portion attached to said frustum of a cone portion;
• a guide member disposed within said housing structure and having an opening formed therein which is shaped to receive said buoyant member in sliding relation therein;
• an elastomeric sealing surface, inserted into a groove of said buoyant member, which is movable into contact with said housing structure proximate said inlet port to prevent a liquid from flowing in a direction from said outlet port through said inlet port;
• and
• a lip formed in said housing structure surrounding said inlet port, said elastomeric member being shaped to form a seal with said lip when said buoyant member moves toward said inlet port and into contact with said housing structure, said housing structure being connected in fluid communication with a cooling system of a marine propulsion system with said inlet port being disposed upstream from said outlet port within said cooling system to receive cooling water from a body of water and said outlet port being disposed downstream from said inlet port within said cooling system to conduct water to a cooling system of an engine of said marine propulsion system.