Automatic engine shutdown and restart system

Claim 1

An automatic shutdown and restart system for a vehicle internal combustion engine having an intake space from which fuel and air are drawn into a combustion space to undergo combustion, a manually operable engine control member for providing operator control of engine speed, and a starter motor, the system comprising: means effective to supply fuel to the intake space; means effective to ignite the fuel and air mixture drawn into the combustion space; means effective to sense engine rotational speed; shutdown means responsive to one characteristic of the engine control member, the shutdown means being effective to (a) disable the fuel supply means from supplying fuel to the intake space to effect engine shutdown and to (b) re-enable the fuel supply means and disable the ignition means when the engine rotational speed decreases to a predetermined value to charge the intake space with a combustible mixture; and restart means responsive to a second characteristic of the engine control member effective to (a) energize the starter motor to effect restart of the internal combustion engine and (b) deenergize the starter motor when the engine rotational speed represents the engine has started, whereby the charging of the intake space with a combustible mixture during engine shutdown is effective to provide a combustible mixture that is drawn into the combustion space when restart is initiated to effect immediate restart of the internal combustion engine.

Claim 5

The method of shutting down and restarting a vehicle internal combustion engine having an intake manifold, a fuel supply system for supplying fuel to the intake manifold, an ignition system, a manually operable throttle valve for controlling air flow into the intake manifold, and a starter motor, the method comprising the steps of: sensing engine speed; disabling the fuel supply system when the throttle valve is closed so as to shut down the engine; re-enabling the fuel supply system and disabling the ignition system when the engine speed decreases to a predetermined value to charge the intake manifold with a combustible mixture; energizing the starter motor when the throttle valve is opened to restart the engine; and deenergizing the starter motor when the engine speed represents that the engine is running, whereby the charging of the intake manifold provides immediate engine restarting capability.

Claim 6

The method of shutting down and restarting a vehicle internal combustion engine having an intake manifold, a fuel supply system for supplying fuel to the intake manifold, an ignition system, a manually operable throttle valve for controlling air flow into the intake manifold, and a starter motor, the method comprising the steps of: sensing engine speed; disabling the fuel supply system when the throttle valve is closed so as to shut down the engine; re-enabling the fuel supply system and disabling the ignition system when the engine speed decreases to a predetermined value to charge the intake manifold with a combustible mixture; energizing the starter motor when the throttle valve is opened to restart the engine; and deenergizing the starter motor when the engine speed represents that the engine is running, whereby the charging of the intake manifold provides immediate engine restarting capability.