Injection-type pressure-freed carburetor

A pressure-feed, fuel injection type carburetor comprising:

• a carburetor base adapted to be connected to an intake manifold of an internal combustion engine, said base having a pair of cylindrical openings therethrough having axial centerlines, a shaft pivotally mounted in said base radially extending across both openings perpendicular to both axial centerlines, a pair of acceleration dampers fixedly mounted on said shaft in said openings and movable with said shaft, vacuum duct means in said base terminating in one of said openings downstream of said dampers, and an idle-speed fuel-air mixture duct terminating in both said openings;
• a main housing connected to said base, said main housing including a pair of venturi-shaped internal bores axially aligned on the centerlines of said openings in said base;
• a gasifier housing connected to one side of said main housing, said gasifier housing including a heated fluid inlet, a heated fluid outlet, a fuel inlet, a fuel outlet, means interconnecting said fuel inlet to said fuel outlet for transferring heat from a heated fluid to a fuel passing therethrough for gasifying a portion of the fuel;
• a secondary housing connected to a side of said main housing opposite said gasifier housing;
• pressure-actuated shut-off means mounted on said secondary housing, including a first valve seat in said secondary housing, a first needle adapted to seat on said first seat, first vacuum-operated diaphragm means mechanically connected to said first needle and operative to move said first needle towards and away from said first valve seat, conduit means interconnecting said fuel outlet of said gasifier housing and said first seat, and conduit means interconnecting said vacuum duct means in said base and said first diaphragm means, said shut-off means permitting fuel flow whenever a vacuum is present in one of said openings downstream of said dampers;
• primary injection metering valve means mounted on said secondary housing and mechanically linked with one end of said pivotable shaft in said base, said primary valve means including first means for metering fuel in response to the rotational position of said shaft, and means for feeding fuel during low speed operation of the engine, said means for feeding being adapted to be progressively throttled back as said means for metering progressively opens;
• complementary injection metering valve means mounted on said secondary housing and mechanically linked with the other end of said pivotable shaft in said base, said complementary valve means including second means for metering fuel in response to the rotational position of said shaft;
• means for interconnecting said shut-off means with said primary valve means and said complementary valve means for fuel flow therebetween;
• means in said secondary housing interconnecting said means for feeding fuel and said idle-speed fuel-air mixture duct in said base, including an idle-speed air intake duct, means for adjusting the amount of fuel entering said air intake duct, and means for regulating the amount of the resultant fuel-air mixture entering said mixture duct;
• a pair of spray units, one mounted in each venturi-shaped bore;
• means in said secondary housing for interconnecting said first means for metering and one of said pair of spray units;
• and
• means in said secondary housing for interconnecting said second means for metering to the other of said pair of spray units.