Engine-condition-responsive cutoff apparatus

Claim 2

Apparatus for cutting off ignition power to an engine having a spark-generating ignition system in response to adverse engineoperating conditions, comprising: an ignition-powering circuit including a source of power connected to the ignition system; means connected to the ignition system for detecting successively occurring spark signals; means for delaying said signals; means connected to said detecting means and said delaying means for timing the overlap between a signal and the delayed previous signal; means connected to said engine for detecting temperature conditions of said engine; and means connected to said timing means and to said temperaturedetecting means and interposed in said powering circuit between said source of power and the ignition system for opening said powering circuit in response to a predetermined overlap of a signal and the delayed previous signal and in response to detection of engine temperature in excess of a predetermined temperature, said means for opening said ignition-powering circuit including switch means in said powering circuit, and an OR gate having a first input connection to said timing means, a second input connected to said means for detecting temperature conditions, and an output connected to said switch means for operating same upon detection of predetermined pulse overlap or an excessive temperature condition.

Claim 3

Apparatus for cutting off ignition power to an engine having a spark-generating ignition system in response to adverse engine-operating conditions, comprising: an ignition-powering circuit including a source of power connected to the ignition system; means connected to said ignition system for detecting successively occurring spark signals; means for delaying said signals; means connected to said detecting means and said delaying means for timing the overlap between a signal and the delayed previous signal; means connected to said engine for detecting pressure conditions within said engine; and means connected to said timing means and to said pressure-detecting means and interposed in said powering circuit between said source of power and the ignition system for opening said powering circuit in response to the detection of a predetermined overlap of a signal and the delayed previous signal and in response to the detection of a pressure within said engine below a predetermined pressure, said means for opening said powering circuit including switch means connected in said powering circuit and operable to open said powering circuit, and an OR gate having a first input connected to said timing means, a second input connected to said pressure-detecting means, and an output connected to said switch means for operating said switch means upon detection of a predetermined pulse overlap or an insufficient pressure condition.

Claim 4

Apparatus for cutting off ignition power to an engine having a spark-generating ignition system in response to adverse engine-operating conditions, comprising: an ignition-powering circuit including a source of power connected to the ignition system; means connected to said ignition system for detecting successively occurring spark signals; means for delaying said signals; means connected to said detecting means and said delaying means for timing the overlap between a signal and the delayed previous signal; means connected to said engine for detecting pressure conditions within said engine; and means connected to said timing means and to said pressure-detecting means and interposed in said powering circuit between said source of power and the ignition system for opening said powering circuit in response to the detection of a predetermined overlap of a signal and the delayed previous signal and in response to the detection of a pressure within said engine below a predetermined pressure, said means for opening said powering circuit including switch means connected in said powering circuit and operable to open said powering circuit, and an OR gate having a first input connected to said timing means, a second input connected to said pressure-detecting means, and an output connected to said switch means for operating said switch means upon detection of a predetermined pulse overlap or an insufficient pressure condition.

Claim 5

Apparatus for cutting off an engine in response to adverse-operating conditions of an engine which includes a fuel-firing system which produces successively occurring fuel firings, comprising: means connected to said engine for detecting successively occurring fuEl firings and generating corresponding firing signals indicative of speed; means for delaying said signals; timing means connected to said delaying means for timing the overlap between a signal and the delayed previous signal to detect excess engine speed; means connected to said engine for detecting at least one adverse-engine-operating condition other than excess speed; and cut off means connected to both said timing means and said adverse-condition-detecting means and interposed in the fuel firing system for rendering the engine inoperative, said cutoff means including switch means in the fuel-firing system and operable to render the fuel-firing system inoperative, and an OR gate including a first input connected to said timing means, a second input connected to said adverse-condition-detecting means and an output connected to said switch means for operating said switch means in response to the detection of excess pulse overlap or an adverse engine-operating condition.

Claim 6

Apparatus for cutting off an engine in response to adverse-operating conditions of an engine which includes a fuel-firing system which produces successively occurring fuel firings, comprising: means connected to said engine for detecting successively occurring fuEl firings and generating corresponding firing signals indicative of speed; means for delaying said signals; timing means connected to said delaying means for timing the overlap between a signal and the delayed previous signal to detect excess engine speed; means connected to said engine for detecting at least one adverse-engine-operating condition other than excess speed; and cut off means connected to both said timing means and said adverse-condition-detecting means and interposed in the fuel firing system for rendering the engine inoperative, said cutoff means including switch means in the fuel-firing system and operable to render the fuel-firing system inoperative, and an OR gate including a first input connected to said timing means, a second input connected to said adverse-condition-detecting means and an output connected to said switch means for operating said switch means in response to the detection of excess pulse overlap or an adverse engine-operating condition.

Claim 7

Apparatus according to claim 3, wherein said delay means comprises a monostable multivibrator for effecting said delay, said fuel firing-detecting means includes means operable to generate bipolar signals, and a clipping amplifier and a differentiator circuit for converting said bipolar signals into pulse signals for said multivibrator.

Claim 8

Apparatus according to claim 4, wherein said monostable multivibrator includes an adjustable circuit for determining signal width of the delayed signal.

Claim 9

Apparatus according to claim 3, wherein said timing means includes an AND circuit for detecting pulse overlap and means for detecting the duration of pulse overlap.

Claim 10

Apparatus according to claim 6, wherein said means for detecting pulse overlap comprises a unijunction transistor circuit including an input electrode and an output electrode, said means for detecting the duration of pulse overlap connected between said input electrode and said AND circuit for firing said unijunction transistor circuit, and said switch means includes a solid-state switching device and a solenoid cutoff device connected in the fuel-firing system and operated by said solid-state switching device, said solid-state switching device including a gate electrode connected to said unijunction transistor circuit whereby firing of said unijunction transistor circuit effects operation of said solid-state switching device.