Patent GB-621485-A (GB)
Title: Improvements in or relating to radio gun control systems
IPC: G01S13/70
Filed: 1943-08-16
Abstract: 621,485. Gun-sight computers. SPERRY GYROSCOPE CO., Inc. Aug. 16, 1943, No. 13316. Convention date, April 30, 1942. [Class 92 (ii)] [Also in Groups XXXV, XXXVIII and XL (c)] In a radiolocation system (see Group XL (c)) specially for use in controlling the guns of aircraft, a directive pulse-emitting transmitter first scans a large solid angle of space, e.g. a hemisphere, by means of a spiral movement, and an indication of the location of any objects within the scanned space is given by a cathoderay tube, the beam of which is given a similar spiral sweep. A rough indication of the range of such objects may also be given. The scanner is then aligned roughly on one of the objects selected as a target and the wide " searching movement " is converted to a " tracking movement " in which the directive beam is rotated over a small conical space including the target. Tracking may be of three kinds:-(1) Manual, in which a cathode-ray tube indicates the difference in orientation between the target and the axis of scanning and an operator sets a computer and the scanner axis to eliminate this difference. At the same time, the range is indicated on the same or a different cathoderay tube and the operator sets this up in the computer. (2) Semi-automatic, in which the scanner is automatically aligned on the target by the receiver and the computer is manually set to follow the scanner. (3) Full automatic, in which the scanner is automatically aligned on the target and the computer automatically follows the scanner. The receiver also gives the range to the computer, but it is necessary in this case for separate means in the computer to determine the rate of change of azimuth and elevation. With all three methods the guns are controlled from the computer setting either automatically or manually. A single set of apparatus with 4-way switches for the different operations may be used. Orientation control of scanner and computer. Fig. 28 shows a complete arrangement of scanner and computer with 4-way switches providing separate connections for the searching operation and the three tracking methods. The manual orientation control 8<SP>1</SP> (see Group XXXVIII) provides independent azimuth and elevational control of potentiometers which produce potentials in their output circuits 166, 172 corresponding to the elevation and azimuth settings and these control computer servomeans 119, 121 to set the computer 7 to a corresponding position. During searching or manual tracking, the scanner is set in synchronism with the computer by servo-means 82, 83 controlled by the transmitters 29, 28 and 88, 87 associated with the scanner and computer respectively. During searching, the computer is set to select the axis of the field of search as desired and during manual tracking the computer is set according to an indicator connected to leads 179 and responsive to a signal from the receiver over lead 94 indicative of the error between the target direction and the axis of the scanner. During semi-automatic tracking, the scanner is set on to the target by servo-means 82, 83 controlled directly from the receiver, and the computer is set manually in synchronism with the scanner by reference to the cathode-ray indicator which now shows the lack of synchronism between scanner and computer. During full-automatic tracking, the manual control 8<SP>1</SP> is disconnected, the scanner is set from the receiver as before, and the computer automatically follows the scanner since servo-means 119, 121 are now in circuit with transmitters 28, 29 and 87, 88. Range-setting of computer. For manual and semi-automatic tracking, a pedal 10 controls a phase-shifter in the range-measuring circuits, and when these are properly adjusted the setting of the phase-shifter gives the range and this is automatically put into the computer by a potentiometer 187 controlling servo-means 122, Fig. 28. For full-automatic tracking, the range is automatically fed into the computer by the receiver over circuit 254, Figs. 28, 30. Specifications 494,288; 579,763, 582,279, 582,492, [all in Group XL], 609,298, [Group XXXVI], 610,704, 621,483, 621,491, 621,492, 621,493 and 635,821, [all in Group XL (c)], are referred to.