Dual fuel carburetion system and method

Apparatus for mixing air with a gaseous fuel for application to the carburetor of an internal combustion engine comprising:

• a mixing chamber having a generally rectangular air inlet passageway in fluid communication with a source of air, a fuel inlet tube adapted for fluid communication with a source of a gaseous fuel, and an outlet passageway adapted for fluid communication with a combustion chamber;
• and
• valve means for restricting the passage of air through said air inlet passageway to said outlet passageway and for restricting the passage of gaseous fuel from said fuel inlet tube to said outlet aperture,
• said valve means including a piston slidable within a chamber and having a generally flat bladed projection, the axis of said cylinder being normal to said air inlet passageway and said chamber being disposed relative to said air inlet passageway so that said flat bladed projection variably restricts the flow of air through said air inlet passageway responsively to the position of said piston in said cylinder,
• said fuel inlet tube supporting said piston within said cylinder and being apertured to variably restrict the passage of fuel into said air inlet passageway responsively to the position of said piston within said chamber and thus to the position of said projection in said air inlet passageway.

A method of mixing air with a gaseous fuel for application to a combustion chamber comprising the steps of:

• (a) providing a mixing chamber having a first inlet passageway in fluid communication with a source of a gaseous fuel, and an outlet aperture in fluid communication with a combustion chamber;
• (b) controlling the passage of air through the first inlet aperture to the outlet aperture responsively to carburetor venturi vacuum by a piston slidable in a cylinder having an axial passage;
• and
• (c) controlling the passage of gaseous fuel from the second inlet aperture to the outlet aperture through the axial passage responsively to the passage of air through the first aperture to the outlet aperture.

A duel fuel system for an internal combustion engine comprising:

• a converter for converting liquified fuel to a gaseous fuel, said converter having a gaseous fuel chamber with a liquified fuel inlet aperture, an engine vacuum inlet aperture and an outlet aperture adapted for communication with the carburetor of an internal combustion engine, said converter being operable responsively to engine manifold vacuum and to the pressure within said fuel chamber to pass gaseous fuel from said inlet aperture to said outlet aperture under a positive pressure;
• a mixer for mixing air with a gaseous fuel for application to a combustion chamber, said mixer having a mixing chamber with an air inlet passageway adapted for fluid communication with a source of air, a gaseous fuel inlet aperture in fluid communication with the outlet aperture of said converter, an outlet aperture adapted for fluid communication with the carburetor of an internal combustion engine, air valve means for restricting the passage of air from said air inlet aperture to said outlet aperture responsively to engine venturi vacuum, and fuel valve means for restricting the passage of gaseous fuel from said fuel inlet aperture to said outlet aperture responsively to movement of said air valve means;
• and
• a manually operable valve adapted for fluid communication with a source of liquified gas, a source of gasoline, atmospheric pressure and engine manifold vacuum, said valve being operative in a first position to pass gasoline to the carburetor of the internal combustion engine and being operative in a second position to pass liquified gas to the inlet aperture of said converter, and to apply engine vacuum to the engine vacuum inlet aperture of said converter.

Apparatus for mixing air with a gaseous fuel for application to a combustion chamber comprising:

• a mixing chamber having an air passageway adapted for fluid communication with a source of air, a fuel inlet aperture adapted for fluid communication with a source of a gaseous fuel, and an outlet aperture adapted for fluid communication with a combustion chamber;
• air valve means for restricting the passage of a ir from said air passageway to said chamber outlet aperture responsively to engine venturi vacuum,
• said air valve means including a piston slidable in a cylinder in a direction normal to the flow of air through said air valve means, and
• said air valve means having an axial passage in fluid communication with said fuel inlet aperture;
• and
• fuel valve means located within said axial passage for restricting the passage of gaseous fuel from said fuel inlet aperture to said chamber outlet aperture responsively to movement of said air valve means,
• said fuel valve means including a valve element movable within said axial passage responsively to movement of said piston in said cylinder,
• said valve element being removable whereby the metering of said fuel valve may be adapted for different fuels,
• said piston being supported within said cylinder by said fuel valve means and including a flat bladed extension apertured to receive said fuel valve means.

Apparatus for mixing air with a gaseous fuel for application to the carburetor of an internal combustion engine comprising:

• a mixing chamber having an air inlet passageway in fluid communication with a source of air, a fuel inlet tube adapted for fluid communication with a source of a gaseous fuel, and an outlet passageway adapted for fluid communication with a combustion chamber;
• and
• valve means for restricting the passage of air through said air inlet passageway to said outlet passageway and for restricting the passage of gaseous fuel from said fuel inlet tube to said outlet aperture;
• said valve means including a piston slidable within a chamber to variably restrict the flow of air through said air inlet passageway responsively to the position of said piston in said cylinder,
• said fuel inlet tube supporting said piston within said cylinder and being apertured to variably restrict the passage of fuel into said air inlet passageway responsively to the position of said piston within said chamber.

Apparatus for mixing air with a gaseous fuel for application to the carburetor of an internal combustion engine comprising:

• a mixing chamber having a generally rectangular air inlet passageway in fluid communication with a source of air, a fuel inlet passageway means adapted for fluid communication with a source of a gaseous fuel, and an outlet passageway adapted for fluid communication with a combustion chamber;
• and
• valve means for restricting the passage of air through said air inlet passageway to said outlet passageway and for restricting the passage of gaseous fuel from said fuel inlet tube to said outlet aperture,
• said valve means including a piston slidable within a chamber and having a generally flat bladed projection, the axis of said cylinder being normal to said air inlet passageway so that said flat bladed projection variably restricts the flow of air through said air inlet passageway responsively to the position of said piston in said cylinder, said piston being supported within said cylinder by said fuel inlet passageway means.