Cold start method and apparatus for carrying out same

Claim 1

Apparatus for reducing exhaust and inoperative pollutants produced by a spark ignition internal combustion engine of the type including an air intake system, fuel intake system, and a carburetor interconnected therebetween for mixing said full-range fuel with air to form a combustible mixture for delivery to combustion chambers of said engine, comprising: i. a stripping column adapted to selectively strip higher molecular weight constituents from said full-range fuel at all engine start conditions during flow through said column so as to provide a cold start fuel vapor effluent composed essentially of only low molecular weight constituents and a bottom liquid product composed essentially of only high molecular weight constituents, ii. valve and conduit network means attached between said stripping column, a reservoir means for said full-range fuel and said carburetor, for providing selective flow conditions, said network means including a first plurality of conduit and valve means including first and second valve means controlling flow of said full-range fuel relative to said stripping column and said carburetor so as to allow, (a) in a first operating state, flow of said fuLl-range fuel from said reservoir means to said stripping column and flow of said cold start fuel vapor effluent to a fuel well of said carburetor to provide for rapid starting of said engine without producing excessive exhaust pollutants and, (b) in a second operating state, full-range fuel to flow directly from said reservoir means to said fuel well of said carburetor bypassing said stripping column after said engine is in a normal running condition, iii. condenser means positioned between said second valve means and said stripping column in operative contact with said cold start vapor effluent for providing liquefaction thereof, iv. control means operatively connected to said first valve means of said valve and conduit network for changing operating state thereof so as to direct fuel flow relative to said stripping column, said reservoir and carburetor as a function of engine operating temperature, v. said network means also including a metering means positioned between said first valve means and said stripping column for metering flow of said full-range fuel to said column as a function of temperature, said metering means including a housing having an inlet opening in fluid contact with said first valve means, movable rod means projecting into said opening and a spring-loaded bimetallic-diaphragm means permanently attached both at a central region to said rod means and at an outer edge to said housing, for controlling movement of said rod means relative to said inlet opening whereby fullrange fuel flow to said stripping column is accurately controlled as a function of temperature.