Settable electronic fuzing system for cannon ammunition

DETAILED DESCRIPTION It is accordingly an object of the present invention to provide an improved electronic fuzing system for cannon ammunition, wherein an electronic fuze can be readily set to operate in several selected detonating modes depending on the nature of the target.
Fuze setting is accomplished expeditiously prior to the ammunition rounds being loaded into a rapid-fire cannon without sacrificing firing rate.
The electronic fuze is preconditioned to a point detonation (PD) mode which prevails if no time-of-flight data is set into the fuze or the entry of such fuze-setting data is determined to be in error.
With the entry of setting data, the electronic fuze functions in a timed detonation (TD) mode, either to explode the projectile in proximity to the target (air burst) or to self-destruct (SD) the projectile in the event a target is not impacted to function the fuze in the TD mode.
To achieve these objectives, the present invention comprises a fuze setter which includes a transmitter for driving an induction coil to transmit projectile time-of-flight data.
An electronic fuze incorporated in the projectile of each of a succession of ammunition rounds includes an induction coil which becomes magnetically linked with the fuze setter induction coil as each round transits a coupling zone in the ammunition feedpath to a rapid-fire cannon.
The time-of-flight data is coupled into the electronic fuze, and a detonation counter is incremented at a high counting rate to a projectile flight time count indicative of the time-of-flight data.
When a round is fired, the detonation counter of its fuze is decremented at a low counting rate and, upon reaching a zero count, functions the projectile warhead in the TD mode.
To confirm that the time-of-flight data was correctly received, a conformation signal indicative of the flight time count accumulated in the detonation counter is transmitted back to the fuze setter.
If a correspondence between the flight time count and the transmitted time-of-flight data is found to exist, the fuse setter conditions the fuze to the TD mode prior to projectile firing