Patent GB-498744-A (GB)
Abstract: 498,744. Gun-fire control; calculating-apparatus. VICKERS-ARMSTRONGS, Ltd., and WATSON, J. P. June 9, 1937, No. 16058. [Class 92 (ii)] [Also in Group XIX] Relates to gun fire predictor apparatus for anti-aircraft gunnery of the kind in which the target vector V of course and speed is resolved into rectangular vector components V1, V1, V3. According to the invention, the resultant vector is computed from the equation V<2>=(V1)<2>+(V2)<2>+(V3)<2> two of the components, such as V2 and V3, being set in, and the third, such as V1, varied and determined when the resultant is matched against an estimated or known value of V. The invention is shown applied to the predicting apparatus described in Specification 498,745, in which a vector diagram appears with the notation adopted in the present Specification. The component vectors V1, V2, V3 are taken respectively along the line of sight, at right-angles to a vertical plane through the line of sight, and at right angles to the line of sight in a vertical plane through the line of sight. In following the target by a sight 1, the generated training produced by hand wheel 3 rotates a pointer 6 which is balanced by a dial 7 rotated by the output shaft 27 of a variable-speed device 25 controlled by a multiplying-device 19 and adjusted by the rotation of a handle 8 which sets in the component V2. The device 19 forms the product RpcosSp where Rp is the present range introduced by a shaft 16 and Sp is the present angle of sight introduced by a shaft 4 which moves in accordance with elevation generated by hand wheel 2 and rotates a pointer 28 balanced by a dial 29. The cam 24 gives the reciprocal quantity 1/RpcosSp and the variable-speed device driven by a constantspeed motor 40 rotates the dial 7 in accordance with the quotient V2/RpcosSp which is the value of the rate of training necessary to balance the pointer 6. The output of a similar reciprocal cam 36 and variable-speed gear 37 operated by the handle 30 which sets in the component V3 rotates the elevation dial 29 in accordance with V3/Rp which is the rate of elevation necessary to balance the pointer 28. Generated range rotates a pointer 45 which is balanced by a dial 44 rotated through a variable-speed device 54 driven by a shaft 48 from a handle 47 which sets in the component V1. The quantities (V2)<2> and (V3)<2> are produced by mechanisms 70, 62 respectively and are summed by a differential-gear 67. To the sum is added the quantity (V1)<2> produced by mechanism 78 and the total passes by shaft 84 to a pointer 85 moving over a dial 86 graduated in accordance with square roots of the vector (V)<2>. Since the components V2 and V3 can be determined with accuracy. it is necessary in order to determine V1 to vary the rotation of handle 47 until the pointer 85 registers with the estimated or known speed V on the dial 86. Range acceleration is produced as described in Specification 414,742 in accordance with the formula dV1/dt=(V2)<2>+(V3)<2>/Rp by two variable-speed gears 92, 94 the inputs from which are in accordance with 1/Rp and (V2)<2>+(V3)<2> respectively, the combined output passing by a shaft 96 to a differential gear 98 on the shaft of the handle 47.