GB128564A - Improvements in or relating to Range Keeping or Predicting Instruments. - Google Patents

Abstract

128,564. Ford, H. C. June 15, 1918, [Convention date]. Computing gun-sighting corrections.-Relates to apparatus for use in gunnery for range keeping and predicting, the rate of variation of the range being known. The range being set by means of a handle 30 and gearing as shown on indicators 1 and 2, the necessary addition to show the present range on the indicator 1 is continuously applied by a roller 5 driven from a timedriven disk 3 by a ball 7 the position of which is set by means of a handle 12, gearing, and a rack 19 carrying a cage 8 surrounding the ball. This variable speed mechanism is similar to that described in Specification 115,345, [Class 80 (ii), Gearing, Variable-speed &c.]. A dial 40 shows the rate of change of range set. The addition is also made to the indicator 2, through a differential gear 45 which allows a further correction to be added to give the predicted range at the moment of impact of the shell. This correction, equal to the time of flight multiplied by the rate of change of range, is obtained by means of an arc 52, set for the rate of change from the handle 12, and carrying a slot 53 in which works a pin on a block 55 sliding in a slot 56 and positioned therein by a screw 58, pinions 59, 60 and jointed shaft 61, 62 gearing with the range-setting spindle 24. The slot 56 is formed in a plate 57 swinging on links 70, 71 the latter carrying an arc gearing with a shaft 75 carrying the spider of the differential gear 45. The time of flight being approximately proportional to the range, corresponds to the radial setting of the pin in the slot 53 and is therefore multiplied by the rate of change of range set as a deflection of the plate 52 which is pivoted at 52' and thus the product, the correction in question, is applied through differential gear 45 so as to display on the indicator 2 the predicted range. While the range is being set on the indicator by means of the handle 30, the roller 5 is rocked out of gear with the ball by means of a key 30'. A differential gear 33 introduced on the spindle 62 permits a correction for the time of transmission to be applied by a handle 65.