Patent · US Expired

Safety device for controlling an ignition circuit

US4223657A · kind A · utility

7Cited by
6References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 8, 1978
Grant dateSep 23, 1980
Priority date
Expiry dateMar 8, 1998

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF02P11/04
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

A safety device for controlling an ignition circuit for an internal combustion engine associated with a transmission coupling the engine to a load comprises a thyristor adapted to permit, upon conduction thereof, the ignition circuit to produce a high voltage to fire a spark plug provided in the engine, a position-responsive switch adapted to permit application of a trigger signal from a power supply to the gate of the thyristor only when the transmission is in neutral, and a capacitor coupled across the gate and cathode of the thyristor to be charged by a voltage drop thereacross and to provide a trigger signal to the gate of the thyristor. Once the capacitor is charged it maintains a condition wherein the thyristor is turned on whenever the thyristor is positively biased even after the transmission is in gear. Thus the safety device disables the ignition circuit to prevent the engine from starting with the transmission in gear, but once the engine is started the transmission can be shifted into gear without disabling the ignition circuit.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.