Patent GB-633474-A (GB)
Title: Improvements in gun control and tracking systems
IPC: G05D3/12
Filed: 1943-10-01
Abstract: 633,474. Gun-laying systems. SPERRY GYROSCOPE CO., Inc. Oct. 1, 1943, No. 16166. Convention date, July 1, 1942. [Class 92 (ii)] A gun-laying system comprises a manuallyoperable controller having an electric input which is such, or is so modified by rate taking means, that a combined signal substantially proportional to the displacement of the controller and to the rate of change of displacement is produced, this signal being applied to a motor or motor arrangement connected to the gun sight and so constructed that its rotational speed is substantially proportional to the strength of the applied signal. In Fig. 1 the system includes a scanner unit 11, gyro unit 12 and computer unit 13, the scanner unit comprising a transmitter 17 whose radiated beam 16 is reflected by a target 19 to a receiver 21. The scanner is actuated by a control 56 via a network 58, amplifier 23 and servomotor 24. The control produces voltage signals corresponding to the desired angular rate of change of the scanner, the network produces output voltages having components proportional to that signal and to its time derivative, and the motor 24 is of a type whose speed is proportional to the input signal. Also driven by the servo 24 and scanner is a selsyn transmitter 26 whose output signal in lead 27 corresponds to the orientation of the target. This lead is connected to a signal generator 38 of the gyro unit as described below, and to a signal generator 29 of the computer unit 13. This generator in conjunction with an amplifier 33 and servomotor 34 serves to impart, to the computer, data corresponding to the target orientation. The gyro unit 12 comprises a gyro 41, Fig. 2, with a housing 101 pivotally mounted in a gimbal ring 102 which is pivotally mounted in a follow-up ring 39, the latter being pivotally supported in a bracket 112 which in turn is pivotally mounted on the aircraft or ship. Fastened to the gyro housing and coaxial with its spin axis is a rod 107 which engages in a slot 108 in a further gimbal ring 109 pivoted to ring 39. The latter carries two torque-producing devices 47, 47<SP>1</SP> adapted to produce torques on the rings 102 and 109 respectively. In operation, when the azimuthal position of ring 39 differs from that of the scanner 14, a sighal from the transmitter 26 produces a corresponding signal in a signal generator 38. This is amplified by an amplifier 46 and produces a torque in motor 47 and a precession of the gyro takes place about an axis 114. Gimbal ring 109 is thereby rotated by the connection 107, 108 and an armature 117 carried by it moves laterally with respect to the core 116 of a pick-off 42, such movement producing a signal for driving a motor 44, the signal being amplified by amplifier 43. Motor 44 drives the rotor of generator 38 and rotates bracket 112 until the gyro and scanner are in correspondence. A further torque motor 47<SP>1</SP> co-operating with a further system similar to Fig. 1 functions similar to bring the scanner and gyro into correspondence about their axis of elevation. The signal input to the torque motor is proportional to the target angular rate and a connection 48 is provided between the motor and an amplifier 49 actuating a servo 51 of the computer to impart the necessary connection thereto. The gyro also serves to actuate the scanner when rapid changes in the attitude of an aircraft takes place. In such an event the relative movement between the gyro and the follow-up device actuates the pick-off 42, for example, and the signal produced is transmitted by lead 53 to the amplifier 23 which operates the servo 24. A further lead 54 connects pick-off 42 with amplifier 33 of the computer. In a modification, Fig. 3, the scanner is dispensed with, the target being tracked by means of an optical system in the computer. A control and network similar to those in Fig. 1 is connected by lead 58<SP>1</SP> to a generator 63 whose output voltage is proportional to its rotational speed, that is, proportional to the speed of data input shaft 31. The manual control and generator are connected in series opposition to an amplifier 33 having a high amplification, whereby a servomotor 34, driving the input shaft, is driven at its maximum speed with a small input signal. The arrangement is such that the output of the generator is substantially equal and opposite to the voltage derived from the manual control and the speed of shaft 31 is therefore proportional to the signal produced by control 56 as modified by network 58. The gyro unit is also as in Fig. 1, having its generator 38 connected to transmitter 291 of the computer and having, in one form, a lead from pick-off 42 connected to amplifier 49 of the computer. Alternatively, as shown, since the voltage produced by the generator 63 represents the angular velocity of the target, the necessary connection for such angular speed is imparted to the computer by connecting the output of the generator with the amplifier 49. In another modification, Fig. 4 (not shown), the two systems of Figs. 1 and 3 are combined, means being provided for switching from one system to the other. Specifications 606,957 and 621,485 are referred to. The Specification as open to inspection under Sect. 91 describes also a modification similar in most respects to the construction shown in Fig. 1, but having means in the scanner unit 11 whereby the target is automatically followed, the manual means 56 being dispensed with. This subject-matter does not appear in the Specification as accepted.