Ignition switch having a positive off and automatic on

• US 5,878,709 A
• Filed: 08/19/1997
• Issued: 03/09/1999
• Est. Priority Date: 08/19/1997
• Status: Expired due to Term

• Current Assignee: Walbro Engine Management LLC (Sun Capital Partners Incorporated)
• Original Assignee: Walbro Corporation (Sun Capital Partners Incorporated)
• Inventors: Koziatek, Jason R., Andersson, Martin N.
• Primary Examiner(s): Okonsky, David A.
• Application Number:
  US08/914,568
• Time in Patent Office: 567 Days
• Field of Search: 123/198 DC
• US Class Current: 123/198.0DC
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02P 11/02 Preventing damage to engines or engine-driven gearing
• CPC Class Codes: F02P 11/025 Shortening the ignition when the engine is stopped to prevent damage to the coil F02P3/0556

Abstract

A positive off and automatic on ignition stop switch and electronic circuit for use in an internal combustion engine. The circuit that allows for normal operation of the engine in an unbiased state. When it is desired to turn the engine off, a stop switch is triggered which provides a single mechanism for shutting off the engine. After the switch is activated, the circuit holds the ignition circuit in an off state for a sufficient amount of time to allow the engine to completely stop operation. The circuit holds the engine in the off state for a period of time even after the switch is deactivated. As a result, the operator of a piece of equipment in which the present invention is utilized can activate a switch one time, which results in the engine coming to a complete stop, without the requirement of further activity.

Claims

1. A capacitor discharge engine ignition system that comprises:

an ignition charge storage capacitor,

an ignition coil for transferring energy to an engine spark plug,

first electronic switch means having a control electrode and primary current conducting electrodes responsive to said control electrode for transferring charge from said ignition charge storage capacitor to said ignitor coil,

a flywheel magneto including a magnet on an engine flywheel,

charge coil means connected to said ignition charge storage capacitor for periodically storing charge on said capacitor responsive to engine rotation of the flywheel and passage of the magnet, and trigger coil means connected to said control electrode and responsive to passage of said magnet for periodically operating said first electronic switch means to transfer charge stored from said charge coil means on said ignition charge storage capacitor to said ignition coil, and

apparatus for selectively preventing transfer of charge from said charge coil means to said ignitor charge storage capacitor, and thereby terminating operation of the engine, comprising;

second electronic switch means having a control electrode, and primary current conducting electrodes connected across said ignition charge storage capacitor and said ignition coil,

third coil means responsive to passage of said magneto magnet, a second capacitor connected in series with said third coil means, and a manual switch connected across said third coil means and said second capacitor, and responsive to an operator for charging said second capacitor from said third coil means response to passage of the flywheel magnet past said third coil means, and

means including a discharge control resistor connected between said second capacitor and said control electrode of said second electronic switch means for controlling discharge of said second capacitor into said second electronic switch means, and thereby interconnecting said primary electrodes of said second electronic switch means to inhibit accumulation of charge on said ignition charge storage capacitor, for a time duration determined by discharge of said second capacitor through said resistor.

2. The system as set forth in claim 1 wherein said first and second electronic switch means comprises differing electronic switch means.

3. The system as set forth in claim 1 wherein said first and second electronic switch means comprise the same electronic switch means, said trigger coil means and said apparatus being connected in parallel to said control electrode.

4. The system as set forth in claim 1 further comprising a diode connected in series with said manual switch to prevent discharge of said second capacitor through said manual switch.

5. The system as set forth in claim 4 further comprising a second diode connected across said third coil means to shunt reverse current generated in said third coil means.

6. The system as set forth in claim 5 wherein said trigger coil means and said third coil means are identically polarized with respect to said magnet and said flywheel.