Apparatus for reducing hydrocarbon content of exhaust gases during deceleration

Claim 1

In a carburetor for an automotive gasoline-powered internal combustion engine and having a float bowl, a throttle chamber, a throttle valve operatively disposed in said throttle chamber, and an idle and slow speed mixture circuit having an idle port and a slow speed port opening into said throttle chamber for supplying said engine with an air-fuel mixture, a system for reducing the concentration of unburned content of the exhaust gases emitted from said engine during decelerating operatioN of the automobile, said system comprising a deceleration circuit independent of said idle and slow mixture circuit and provided between said float bowl and said throttle chamber for supplying an air-fuel mixture to said engine in addition to and independent of an air-fuel mixture supplied to said engine through said idle and slow speed mixture circuit during decelerating operation of the automobile, and a solenoid valve assembly controlling the flow of said airfuel mixture through said deceleration circuit, said deceleration circuit including an atomizer provided downstream of said float bowl and formed at its bottom a jet nozzle and its top a first air bleed vented to the atmosphere, a second air bleed provided in said deceleration circuit downstream of said first air bleed, and a deceleration port communicating with said deceleration circuit and opening into said throttle chamber at a position downstream of said throttle valve, and said solenoid valve assembly including a valve in said deceleration circuit downstream of said second air bleed and means responsive to a decelerating condition of the automobile to actuate said solenoid valve assembly to open said valve to permit the flow of said airfuel mixture through said deceleration circuit, whereby said engine is supplied with an air-fuel mixture through said deceleration circuit independently of the air-fuel mixture fed through said idle and slow speed mixture circuit.