Engine distributor spark advance system

Claim 1

Distributor spark advance and retard control means for an internal-combustion engine comprising, in combination, a carburetor induction passage connected at one end to the intake manifold of said engine and to a source of fuel and air at the opposite end and having a venturi and a throttle valve rotatably mounted in said passage posterior of said venturi and movable from an idle speed position to variably control the flow of an air-fuel mixture through said passage, a spark control port connected to said passage on the air inlet side of said valve when in an idle speed position, said port being subjected at all times to vacuum from said manifold upon movement of said valve from said idle position, an operator movable accelerator means movable from a closed at rest position towards a wide-open throttle position, a distributor spark advance and retard vacuum servo actuator, first conduit means connected to said servo actuator, second conduit means connected to said spark port, and valve means interconnecting said conduit means and controlling flow of fluid therethrough, said valve means including a valve body secured to said throttle valve for movement thereof, a control valve variably movable within said valve body between one position connecting the vacuum at said spark port to said servo actuator to advance the spark timing as a function of changes in vacuum level and a second position connecting said servo actuator to air at essentially atmospheric pressure to retard said spark timing by blocking the vacuum to said second conduit means, linkage means connecting said control valve to said operator movable accelerator means, spring means operatively connected to and biasing said control valve to said second position and operatively biasing said throttle valve to said idle speed position, movement of said accelerator means in a throttle valve opening direction moving said control valve to said one position to advance said spark and also operatively moving said valve body to move said throttle valve away from said idle position to increase the vacuum level to said servo, second linkage means securing said valve body to said throttle valve, and time delay means in the path of movement in a throttle valve closing direction of said second linkage means engageable by said second linkage means upon movement of said accelerator pedal and first linkage means towards a closed position, the movement of said accelerator pedal to its closed pOsition from an open position immediately moving said control valve to block the vacuum in said spark port from said servo and connect air to said servo while said time delay means is simultaneously slowly retarding the closing of said throttle valve to permit continued air flow through the carburetor induction passage to dry said passage.