Antipollution apparatus for motor vehicle engines

Claim 1

In combination with an ignition advancing mechanism of a motor vehicle gasoline engine comprising a casing, a diaphragm dividing the interior of said casing into a vacuum chamber and an atmospheric pressure chamber, and an actuating rod having one end coupled to said diaphragm and the other end projecting out of said casing via said atmospheric pressure chamber, said actuating rod being adapted to cause the distributor of the motor vehicle engine to advance the ignition timing in response to a variable degree of vacuum created in said vacuum chamber, an antipollution apparatus comprising: a housing substantially in the shape of a hollow cylinder; a pair of spaced-apart diaphragms within said housing pressuretightly dividing the interior thereof into: a first chamber adjacent one end of said housing which communicates with the interior of the intake manifold of the motor vehicle engine; a second chamber intermediate both ends of said housing which communicates with the atmosphere; and a third chamber adjacent the other end of said housing; means interconnecting said pair of diaphragms in spaced-apart relationship; partition means fixedly mounted in said third chamber and pressure-tightly subdividing the same into first and second sections, said partition means being normally held in pressuretight contact with one of said pair of diaphragms to hold said first and second sections out of communication from each other; means communicating said first section of said third chamber with the interior of the carburetor of the motor vehicle engine at a point adjacent its throttle valve; means further communicating said first section of said third chamber with said vacuum chamber of said ignition advancing mechanism; and means communicating said second section of said third chamber with the atmosphere; whereby when a prescribed degree of vacuum builds up within said intake manifold during operation of the motor vehicle engine, said pair of diaphragms are caused to deflect simultaneously by suction exerted Through said first chamber, thereby intercommunicating said first and second sections of said third chamber and hence nullifying the ignition advance which has been caused by said ignition advancing mechanism.