Patent GB-462830-A (GB)
Title: Electric calculating apparatus more particularly designed for firing problems
IPC: F41G11/00
Filed: 1935-09-16
Abstract: 462,830. Electric signalling systems. GRANAT, E., and COMPAGNIE DES FORGES ET ACIERIES DE LA MARINE ET D' HOMECOURT. Sept. 16, 1935, No. 25687. Convention date, Oct. 23, 1934. [Class 40 (i)] [Also in Group XIX] A device for evaluating expressions of the form x sin z or x cos z more particularly for use on aircraft in connection with gunnery problems comprises a log 31 which drives, through an auxiliary motor 32, a dynamo 33 the exciter field of which is constant, and a wind vane (not shown), which adjusts the angular position of a set of brushes 34. The difference in potential between the set brushes and consequently the strength of the output current will be proportional to the product of the speed of the aircraft (x) and to the sine or cosine (z) of the angle given by the wind vane. The Specification as open to inspection under Sect. 91 comprises also electric circuit arrangements for obtaining output currents proportional to (1) the products sin x tan y, and xy sin t sin u, and (2) the sum of a number z of variables. A differential relay is described for receiving the output current to cause a motor to rotate through an angle proportional to the strength of the current to control apparatus. The arrangement shown in Fig. 1 (Cancelled) for calculating the correction sin x tan y for gun laying on board ship where x is the inclination of gun turret and y is the firing angle, comprises a motor 1 the stator and rotor of which are connected to the mains 2. The rotor is mechanically connected to a second motor 9 receiving by means of brushes 11, 12 a current proportional to tan y from a commutator 25 with segments connected to a resistance 26. A dynamo 15 driven by a motor 27 is provided with two commutators 16, 17 with adjustable brushes connected to the commutator 25 and to the stator of motor 9 respectively. The current to the stator is proportional to sin x and a torque proportional to sin x tan y is produced by motor 9. By rotating the rotor of motor 1 the torques can be balanced and the result read off or transmitted to a controlling apparatus 10. Fig. 4 (Cancelled) shows an arrangement to evaluate the expression xy/z sin t sin u for aircraft gunnery problems where x is the speed of the target aircraft, y is the time of flight of the projectile, z is the range, t is the angle between the longitudinal axis of the aiming aircraft and the path of the target aircraft, and u is the angle between the plane containing the axes of the aiming aircraft and another plane containing the gun axis and line of flight of target. The arrangement comprises adjustable resistances and potentiometers. The first resistance 71 is such that the current in line 72 is proportional to the displacement x of the sliding contact ; the movable contacts 48 of the potentiometer 47 are adjusted so that the angular adjustment is proportional to t. The potential difference between rings 73, which is proportional to x sin t is applied to the ends of potentiometer 49 the distance of the sliding contact of which from the end point 79 is proportional to y so that the potential difference between the points 78, 79 is proportional to xy sin t. The resistance 51 in the circuit 75 is adjusted to represent the value z so that the potential difference applied to the potentiometer 52 is proportional to xy/z sin t. If the sets of contacts 53, 54 are set to correspond to the value u the circuits 76, 77 will be supplied with current proportional to the values:- xy/z sin t sin u and xy/z sin t cos u. For adding quantities the arrangement of parallel rheostats 37, 38, 39, 41 as shown in Fig. 3 (Cancelled) may be provided the resistances being inversely proportional to the variables x, y, z, and t, to be added so that the output current is proportional to their sum. To control other apparatus a differential relay as shown in Fig. 5 (Cancelled) is provided. One of the windings of the relay is supplied with current i1 representing the output current of a calculating device as above described while the other winding is supplied with current i2 by a circuit including a rheostat 61. If these currents vary the relay armature is deflected to complete a circuit through a contact 78, or 79 to start a motor 62 to drive the contact arm of the rheostat in one direction or the other until the currents are balanced and to drive the control apparatus 80. This subject-matter does not appear in the Specification as accepted. Specification 260,579, [Class 40 (i)], is referred to.