| 摘要 |
A dual fuel system for use with internal combustion engines comprising a manually actuated dual fluid valve which alternatively supplies gasoline to the engine's carburetor or engine intake manifold vacuum to a single-stage liquified gas to gaseous fuel converter having a liquified fuel inlet valve actuated in response to intake manifold vacuum by a diaphragm of substantially the same diameter as a second diaphragm which actuates a valve to a converter gaseous expansion chamber where desired gaseous pressure is maintained and is automatically reduced during cruise conditions by compression of a bellows which acts on the second diaphragm in response to reduced engine intake manifold pressure during such cruise conditions, and a pressurized gaseous fuel and air mixer having a plunger structure responsive to venturi vacuum which meters air flow and actuates a valve needle to meter fuel flow. One alternative preferred embodiment of the mixer employs a relatively large piston which travels a relatively short distance within a cylinder and meters flow of air between the lower surface of the piston and a coaxial annular surface defining a passage into which air flows between such surface and the piston together with fuel, which fuel flows into the fuel and air passage through the piston and through a fuel transfer tube that acts as a piston guide. A second alternative preferred embodiment of the mixer utilizes a smaller diameter piston which travels a relatively long distance and a substantially oval plunger which projects into a substantially rectangular air passage to meter air flow. |
