Hermetically sealed, relatively low pressure cooling system for internal combustion engines and method therefor

Claim 1

A hermetically sealed, relatively low pressure cooling system for internal combustion engines including a thermostat which opens at a predetermined engine operating temperature, comprising: a hermetically sealed radiator having a filling neck, a non-pressurized cap in sealed relationship with said filling neck and unrestricted coolant outlet means located in the top portion of said radiator below said non-pressurized cap; and a small expansion reservoir for liquid coolant connected in hermetically sealed relationship with said coolant outlet means and being location and including coolant inlet means at or above the elevation of said coolant outlet means, and including means connecting said coolant inlet means of said expansion reservoir with said coolant outlet means of the radiator, so that coolant will reside in the lower portion of the expansion chamber when said radiator is filled with coolant and having a closed dead air space in the upper portion of the expansion reervoir wherein liquid coolant due to a engine heating during operation expands and flows freely from the radiator by means of said coolant outlet means upwardly and into said expansion reservoir causing a relatively low pressure to be built up in the dead air space behind the coolant and subsequently returning from the reservoir into the radiator under the influence of the relatively low pressure in the closed dead air space to maintain the cooling system at a full level at all times, whereby pressure in the hermetically sealed cooling system is maintained at a relatively low value compared to conventional high pressure systems which operate at or near 15 psi, said low pressure causing the boiling point of the coolant to remain at a relatively low value, permitting said thermostat of the engine to thereby control engine temperature over substantially the full range of engine operation and thus causing said engine to operate at a temperature at or in relatively close proximity to said predetermined temperature of the thermostat.

Claim 12

A method of operating an internal combustion engine at a temperature corresponding to the opening and closing temperature of the thermostat installed in the cooling system of the engine, comprising the steps of: confining liquid coolant within a hermetically sealed cooling system including a radiator having a filling neck, a non-pressurized cap in sealed relationship with said filling neck and unrestricted coolant outlet means located in the top portion of said radiator below said non-pressurized cap and an expansion reservoir for liquid coolant connected in hermetically sealed relationship with said coolant outlet means including a coolant inlet means and being located at or above the full level of coolant in the radiator, and including means connecting said coolant inlet means of said expansion reservoir with said coolant outlet means of the radiator, filling the radiator to the full coolant level, allowing the coolant to expand and flow freely upwardly from the full coolant level of the radiator into a lower portion of the coolant expansion reservoir during engine operation, said reservoir further including a closed dead air space above the lower portion of the reservoir filled with coolant causing a relatively low pressure to be built up in the closed dead air space behind the coolant, and effecting automatic return of the expanded coolant in said reservoir to the radiator under the influence of said relatively low pressure in the dead air space of said reservoir behind said coolant, whereby pressure in the hermetically sealed coolant system is maintained at a relatively low level compared to conventional high pressure systems which operate at or near 15 psi, said low level being determined by the pressure behind the coolant in the closed dead air space of the reservoir, said relatively low pressure causing the boiling point and temperature of the coolant to remain at a relatively low level thereby permitting the thermostat to control the engine temperature over substantially the full operating range of the engine, and thus causing said engine to operate at or in relatively closed proximity to said predetermined temperature of the thermostat.

Claim 13

A method of operating an internal combustion engine at a temperature corresponding to the opening and closing temperature of the thermostat installed in the cooling system of the engine, comprising the steps of: confining liquid coolant within a hermetically sealed cooling system including a radiator having a filling neck, a non-pressurized cap in sealed relationship with said filling neck and unrestricted coolant outlet means located in the top portion of said radiator below said non-pressurized cap and an expansion reservoir for liquid coolant connected in hermetically sealed relationship with said coolant outlet means including a coolant inlet means and being located at or above the full level of coolant in the radiator, and including means connecting said coolant inlet means of said expansion reservoir with said coolant outlet means of the radiator, filling the radiator to the full coolant level, allowing the coolant to expand and flow freely upwardly from the full coolant level of the radiator into a lower portion of the coolant expansion reservoir during engine operation, said reservoir further including a closed dead air space above the lower portion of the reservoir filled with coolant causing a relatively low pressure to be built up in the closed dead air space behind the coolant, and effecting automatic return of the expanded coolant in said reservoir to the radiator under the influence of said relatively low pressure in the dead air space of said reservoir behind said coolant, whereby pressure in the hermetically sealed coolant system is maintained at a relatively low level compared to conventional high pressure systems which operate at or near 15 psi, said low level being determined by the pressure behind the coolant in the closed dead air space of the reservoir, said relatively low pressure causing the boiling point and temperature of the coolant to remain at a relatively low level thereby permitting the thermostat to control the engine temperature over substantially the full operating range of the engine, and thus causing said engine to operate at or in relatively closed proximity to said predetermined temperature of the thermostat.