Marine engine cooling system employing a thermostatic valve means and a pressure relief valve means

Claim 2

An internal combustion engine having a cooling jacket means and a pump for circulating coolant through the jacket in accordance with a pressure related to the engine speed, a valve seat means defining an outlet duct for communication between the cooling jacket and a discharge chamber, a pressure relief valve member seated on said valve seat means and resiliently biased to a closed position and providing an initial opening in response to a selected coolant pressure in said jacket, a fluid pressure responsive operator means coupled to said valve member and subjected to the pressure on the discharge chamber side of the valve member said operator including a diaphragm means in said discharge chamber and coupled to said valve member and subjected to the pressure on the downstream side of the valve member and said diaphragm means providing a snap action opening of the valve member in response to initial opening thereof to produce a complete and stable opening of the outlet duct.

Claim 3

The engine of claim 1 wherein said valve member has an opening stroke selected to produce a self-cleaning pressure relief valve movement by disrupting and transferring foreign matter through the valve opening.

Claim 4

The poppet valve of claim 4 wherein said diaphragm means includes a diaphragm secured between an exhaust baffle plate and an outer manifold cover of said engine, a valvE stem secured to said valve member and said diaphragm, said diaphragm being responsive to a selected opening of the valve member to cause such valve member to move to the fully open position and thereby establishing essentially maximum flow of water from the cooling jacket means, said cover limiting the outward movement of said valve stem.

Claim 5

The engine of claim 1 wherein said diaphragm means is secured in overlying relationship to the valve member and including a central portion secured thereto, said diaphragm means being formed with an effective area insufficient to overcome the force of the resilient means with the valve member closed, said diaphragm means being responsive to a selected opening of the valve member to cause such valve member to move to said fully open position and thereby establishing essentially maximum flow of water from the cooling jacket.

Claim 6

The engine of claim 1 wherein said valve seat means includes a grommet having a flat sealing face in the discharge chamber, said valve member being a plate resting on the sealing face and including a guide means extending downwardly through the grommet, a valve stem integrally formed to the back side of the plate and extending outwardly through the discharge chamber, said operator means including a diaphragm secured to the outer wall of the chamber in overlying relationship to said valve stem, means interconnecting the valve stem to said diaphragm to expose the diaphragm to the water in the discharge chamber, stop means to limit the outward movement of the diaphragm and the interconnected valve stem and valve plate, and a resilient bias spring action between the back side of the valve plate and the aligned opposed surface of the outer wall, said spring resiliently urging said valve plate to a closed position.

Claim 7

The engine of claim 5 having an outer cover secured over the diaphragm and being from said valve stem assembly to define said stop means for the outward movement of the valve plate and establishing a movement of the order of tenths of inches to thereby establish a relatively unrestricted opening in response to the initial opening of the relief valve.

Claim 8

The engine of claim 1 wherein said operator includes a diaphragm chamber, said diaphragm means includes a diaphragm in said diaphragm chamber and connected in spaced relations to said valve member, and a liquid flow restricting passageway connecting said discharge chamber to the diaphragm chamber.

Claim 9

The engine of claim 1 wherein said poppet valve member is a plate resting over the opening to the discharge side of said outlet duct, a valve stem integrally formed to the back side of the valve plate and extending outwardly, an outer plate secured to the engine and including a hub member extending downwardly concentrically over the valve stem and in laterally spaced relation thereto to define a restricted flow passageway, an outer cover secured to the outer plate, said diaphragm means including a diaphragm secured between the cover and the plate in overlying relationship to the valve stem, means interconnecting the valve stem to said diaphragm, said baffle plate and said cover being offset with respect to the position of the diaphragm with the valve plate in the closed position.

Claim 10

In an outboard motor an internal combustion engine having a cooling jacket and a cooling pump for withdrawing water from the body of water within which the outboard motor is operating and causing it to circulate upwardly through the cooling jacket and having a discharge passageway to return the water from the cooling jacket to the body of water and a pressure relief valve means in said discharge passageway, said pressure relief valve means comprising an outlet opening from the cooling jacket to the discharge passageway means including a circular grommet secured within the opening by a grommet carrier and defining a valve seat, a poppet valve member including a poppet valve plate resting on the grommet to the discharge side of said opening and iNcluding a cruciform guide extending downwardly through the grommet, a valve stem integrally formed to the back side of the valve plate, a manifold baffle plate secured to the engine and including a hub member extending downwardly concentrically over the valve stem and in laterally spaced relation thereto, an outer manifold cover secured to the baffle plate, a diaphragm secured between the cover and the baffle plate in overlying relationship to said valve stem, means interconnecting the valve stem to said diaphragm, said baffle plate and said cover being offset with respect to the position of the diaphragm with the valve plate engaging the grommet to permit restricted movement of the diaphragm to expose the diaphragm to the water in the discharge passageway and to establish limited outward movement of the diaphragm and the interconnected valve stem and valve plate, and a resilient bias spring encircling said hub and valve stem and acting between the back side of the valve plate and the aligned opposed surface of the baffle plate, said spring urging said valve plate to a closed position.

Claim 11

In an outboard motor an internal combustion engine having a cooling jacket and a cooling pump for withdrawing water from the body of water within which the outboard motor is operating and causing it to circulate upwardly through the cooling jacket and having a discharge passageway to return the water from the cooling jacket to the body of water and a pressure relief valve means in said discharge passageway, said pressure relief valve means comprising an outlet opening from the cooling jacket to the discharge passageway means including a circular grommet secured within the opening by a grommet carrier and defining a valve seat, a poppet valve member including a poppet valve plate resting on the grommet to the discharge side of said opening and iNcluding a cruciform guide extending downwardly through the grommet, a valve stem integrally formed to the back side of the valve plate, a manifold baffle plate secured to the engine and including a hub member extending downwardly concentrically over the valve stem and in laterally spaced relation thereto, an outer manifold cover secured to the baffle plate, a diaphragm secured between the cover and the baffle plate in overlying relationship to said valve stem, means interconnecting the valve stem to said diaphragm, said baffle plate and said cover being offset with respect to the position of the diaphragm with the valve plate engaging the grommet to permit restricted movement of the diaphragm to expose the diaphragm to the water in the discharge passageway and to establish limited outward movement of the diaphragm and the interconnected valve stem and valve plate, and a resilient bias spring encircling said hub and valve stem and acting between the back side of the valve plate and the aligned opposed surface of the baffle plate, said spring urging said valve plate to a closed position.

Claim 12

The engine of claim 9 wherein said cover is spaced from said valve stem assembly to permit outward movement of the valve plate of the order of tenths of inches to thereby establish a relatively unrestricted opening in response to the initial opening of the relief valve, the length of said stroke being selected to disrupt and transfer foreign matter passing through the valve and thereby produce a self-cleaning pressure relief valve movement.