GB167191A - Improved apparatus for predicting the future position of a target or other moving object - Google Patents

Abstract

167,191. Holden, H. C. L. Sept. 24, 1918. Methods of sighting.-Relates to apparatus for predicting the future position of a moving object, and consists in means for giving the linear displacement of the object in two directions at rightangles to each other during a predetermined period, such as the time of flight of a projectile. In the form shown, as applied to anti-aircraft gunnery predicting-apparatus, a sighting device e, Fig. 1, at an observing station is elevatable to maintain the sight on the target by operating a hand-wheel f, which displaces axially along a shaft c a bar a, the upper end of which bears against the sight e. The bar a may be raised to correspond in height to any given height of target. The shaft c drives a magneto h in circuit with a rheostat p which may be set for the time of flight t, and voltmeter i then indicates the displacement of the target along the line of sight in time t. The sighting-device e is rotatable in azimuth by a hand-wheel m, which similarly drives a magneto n in circuit with two rheostats which may be set for horizontal range and time of flight; a voltmeter o then indicates the horizontal displacement of the target at rightangles to the line of sight in time t. The rheostats and voltmeters may be situated at a central station, to which the horizontal range and bearing of the target is transmitted by telephone or otherwise. At this station is a predicting-instrument shown in Figs. 2 and 3, comprising a fixed arm r along which an arm s may be displaced proportionally to the horizontal range. A carriage w may be displaced along the arm s proportionally to the change in horizontal range in time t, and a vertical pillar 1 on the carriage w may be displaced at right-angles to the arm s proportionally to the displacement of the target at rightangles to the line of sight in time t. The horizontal distance of the pillar 1 from the zero point v of the instrument is then the future horizontal range after time t. The pillar carries a slide 4 rotatable horizontally in a guide 5 pivoted immediately above the zero point v. The slide carries a drum 6 on which are curves showing fuze and quadrant elevation plotted axially against height plotted peripherally, these curves being read against fixed pointers 7. The bearing of the target is set on a graduated arc 8 by a hand-wheel 9, and to it is added the angle between the axis of the drum 6 and the fixed arm r by means of a parallel link device 10, the pointer 11 of which indicates the future bearing of the target after time t.