Speed controlled ignition retarder

Claim 1

An ignition retarding device for ready attachment to and modification of an automotive vehicle having a multicylinder internal combustion engine for propelling the vehicle, in which the internal combustion engine has an ignition device for each cylinder, a battery, voltage pulse producing means connected to said battery and including a distributor and distributor points driven by the engine and effective to cause opening and closing of said distributor points by operation of said engine to produce high voltage igntion pulses of a frequency dependent upon the speed of said engine, said distributor being effective to apply the high voltage pulses to the ignition devices for the cylinders in a timed relation to the engine cycle, said distributor being adjustable to vary the Ignition timing, means including a fluid motor for adjusting the ignition timing, and means including a conduit between said fluid motor and the intake manifold of the engine for normally causing said motor to adjust the distributor to advance the timing as the vacuum in said intake manifold increases; said ignition retarding device comprising: an electrically operated valve having coupling members of a size and type for quick coupling with said conduit so as to facilitate insertion of the valve into the conduit conection between the motor and the intake manifold of the engine to prevent advance of the timing from an increase in the vacuum in the intake manifold when the valve is closed; electronic speed responsive means having input terminals for electrical connection to said points and effective when so connected to produce at its output an electrical effect dependent upon the frequency of such high voltage ignition pulses and hence upon the speed of the engine; control means for said electrically operated valve connected to the output of the speed responsive means independently of the load on the engine and effective when the engine speed drops below a predetermined value as sensed by said speed responsive means and independently of the engine load to affect the energization of said electrically operated valve to cause closure of the same to interrupt the connection between the fluid motor and the intake manifold to prevent advance of the timing from an increase in the vacuum in the intake manifold as long as said speed remains below said predetermined value, unless the engine temperature rises above a predetermined undesirable value; further means connected to said control means for controlling the same and for causing the same to affect the energization of said valve to cause opening of the same to restore the connection between the fluid motor and the intake manifold regardless of the speed of the engine whenever the engine temperature rises above a predetermined value; and means for connection to the battery of the automotive vehicle for deriving from said battery a source of power for energizing said speed control means and said control means for said valve, the electronic components of the electronic speed responsive device being semiconductors requiring the application thereto of voltages no greater than that of the battery of the automotive vehicle so that the source of power derived from the connection to the battery employs no voltage increasing means.