Abstract: An engine over speed detection circuit for determining an engine over speed condition is described. The circuit includes a detection unit configured to send a pulsed signal indicative of engine speed; a reactive impedance configured to discharge upon receipt of a pulse of the pulsed signal at a rate defined by the pulsed signal; a comparator unit to compare a voltage or current value of the reactive impedance with a threshold value and to output the result of the comparison at the rate of the pulsed signal.

Abstract: An armature assembly for a solenoid valve allows for a valve member to be retained in the closed position through a biasing force being applied therein. A moveably supported armature bolt is movable between a first position and a second position. A valve member is coupled to the armature bolt and is configured to close with the armature bolt at the second position. An armature body is coupled to the armature bolt. A resilient member adapted to hold the armature bolt at the second position so as to retain the valve member in the closed position.

Abstract: An armature assembly for a solenoid valve allows for a valve member to be retained in the closed position through a biasing force being applied therein. A moveably supported armature bolt is movable between a first position and a second position. A valve member is coupled to the armature bolt and is configured to close with the armature bolt at the second position. An armature body is coupled to the armature bolt. A resilient member adapted to hold the armature bolt at the second position so as to retain the valve member in the closed position.

Abstract: Apparatus and a method are disclosed for flame-proofing an internal combustion engine by provision of a sensor for detecting the presence of flammable gases in the vicinity of the assembly, a canopy shrouding a hot surface of the engine, and a source of non-flammable fluid operable responsive to signals from the sensor to inject the fluid into the space between the canopy and the said surface, thereby cooling the hot surface and inerting the atmosphere within the canopy.