GB446055A - - Google Patents

Abstract

446,055. Anti-aircraft gun sights. NAAMLOOZE VENNOOTSCHAP NEDERLANDSCHE INSTRUMENTEN COMPAGNIE NEDINSCO, 9, Molensingel, Venlo, Holland. July 29, 1935, No. 21443. Convention date, Aug. 4, 1934. [Class 92 (ii)] Relates to apparatus for calculating and applying to anti-aircraft guns the lead corrections in elevation and azimuth for speed of target and of the kind in which the target is followed by a sight 2 driven by a constant-speed motor 24 through a handadjusted change-speed gear 19, 20. According to the invention, a second change-speed gear 22, 23 is provided for controlling the angular speed of the driving member 20 of the first change-speed gear in accordance with the reciprocal of the time of flight, the radial movement given to the driven member 19 by adjusting the handle 12 in following the target is then a measure of the required lead. Fig. 1 is a diagram showing the angles involved in correcting the elevation for a target flying from Z to T. The apparatus for giving continuously the corrected elevation #T is shown in Fig. 2. By rotating the handle 12 with clutch 16 disconnected, a shaft 5 is rotated to elevate the sight 2 about the axis Y-Y, and by moving the whole apparatus about an axis X-X the sight is brought on to the target. By engaging the clutch 16 and adjusting the handle 12, the telescope is driven by the motor 24 through the change-speed gears, shaft 9, and differential gear 7 to follow the target continuously at an angular velocity w, the shaft 9 rotating proportional to this velocity. The disc 20 is rotated proportional to 1/t, where t is the time of flight, by displacing the roller 22 relatively to the disc 23 by means of a rack 28 moved by a cam 29. The cam is rotated proportional to target elevation gammaT and translated proportional to range ET. The shaft 17, in setting the roller 19 relatively to the disc 20 to cause the shaft 9 to rotate proportional to w, must therefore rotate proportional to the product wt. The rotation of the shaft 17 is conveyed to one side wheel 39 of a differential gear the other side wheel 43 of which rotates proportional to the present elevation gammaM. The planet wheel 37 then rotates the shaft 31 proportional to (gammaM+wt)=gammaT which is conveyed to the gun. The Specification describes the use of the apparatus in applying the lead correction in azimuth.