Variation of engine coolant heater

Claim 1

A heating device for an internal combustion engine having an intake manifold and a block adapted for circulation of a liquid coolant therein comprising, in combination, a tank having an interior and a liquid inlet and a liquid outlet communicating with said interior, conduit means for connecting said tank inlet and outlet to said engine block for circulation of liquid coolant between said tank and said block, an enclosure having an interior disposed within said tank in sealed relationship therewith, said enclosure being arranged in spaced relationship with said tank to define a liquid chamber substantially surrounding said enclosure in heat transfer relationship therewith, an air inlet in said enclosure for introducing outside air into said enclosure interior and an air outlet for discharging air from said enclosure interior, means for heating the air introduced into said enclosure interior whereby heat is transferred from heated air flowing in said enclosure to said liquid in said liquid chamber thereby supplying heated coolant to said engine block, duct means for connecting said enclosure air outlet to said intake manifold to heat said intake manifold with said heated air from said enclosure, including a valve in said duct means, movable between a closed position and an open position, said valve being normally maintained in the open position during the operation of said heating device and means responsive to the starting of said internal combustion engine for moving said valve into said closed position said duct means and said valve being arranged so that when said valve is in a closed position in said duct means communication thereof with said intake manifold is completely interrupted, said valve entirely closing said duct.