GB127292A - Improvements in Chronotelemetrical Apparatus for use in Regulating the Firing of Anti-aircraft Guns. - Google Patents

Abstract

127,292. Maison BrÚguet, and Routin, J. L. Dec. 6, 1915, [Convention date]. Addition to 127,280. Electric speed indicators operating by sighting aerial objects; velocity components, measuring - Consists in modifications of the devices for obtaining the correction due to speed of target in the anti-aircraft gunnery apparatus described in the parent Specification. The angular speed of the target is measured by a magneto driven at a speed proportional thereto, and the corresponding reading in a voltmeter of the E.M.F. is reduced proportionally to the time of flight of the projectile, so as to obtain a direct reading of the angular speed and the time of flight. In the construction shown in Fig. 1, the effect of the magneto 1 on the voltmeter 2 is reduced by periodically breaking the circuit by a rapidly rotating drum 3 having a projecting contact surface bounded on one side by a helix so that the duration of the closing of the circuit can be made proportional to the time of flight by adjusting the brush 4 axially along the drum. In a modification, the E.M.F. of the magneto for a determined speed is reduced by displacing the brushes of the armature coil of the magneto through an angle. In another modification, Fig. 4, the magnetic flux of the voltmeter 2 is modified by displacing a magnetic member 3 about an axis 4, the amount of displacement being indicated by a pointer 7. The reading of the voltometer may also be reduced by shunting the voltmeter with a variable resistance, or by a potentiometer.