Patent GB-456078-A (GB)
Title: Improvements relating to aircraft locating systems
IPC: G01S1/72
Filed: 1935-07-19
Abstract: 456,078. Locating sounds and like vibrations. SPERRY GYROSCOPE CO., Inc., Manhattan Bridge Plaza, Brooklyn, New York U.S.A.-(Assignees of House, F. R.) July 19, 1935, No. 20634. Convention date, July 19, 1934. [Class 118 (ii)] In a sound locator having means for compensating sound lag or like errors, the compensator is mounted in the same unit as the locating horns and a binocular, also mounted on the same unit, is set in accordance with the compensated readings. The unit is arranged to control a searchlight, the control being taken over by the binocular mountings after the aircraft has been located. The apparatus comprises means for oscillating the sound locator and searchlight whilst two methods for compensating for movement are described embodying electrical and fan control respectively. As shown in Fig. 1, three horns 1, 2, 3 are mounted on the box 5 which also carries binoculars 4 and correction mechanism 41. The horns 1 and 2 are connected to the elevational headpiece 38 so that an operator seated on 14 can listen through the horns and adjust their elevation by handle 15. Similarly, horns 2 and 3 are connected to the azimuth headpiece 35 and an operator seated on 13 can turn the whole system by handle 7. The horn system is arranged to oscillate about the axis of rod 34 to increase the field of hearing and the sensitivity of the device. The searchlight S is controlled by movement of transmitters A and E, the rotors of which are controlled by handles 7 and 15 and the fields by correction mechanism 41. Handle 42, Fig. 2, is provided to enable the searchlight to scan the area around the position indicated, as described in Specification 415,201. The scanning is effected by pin 49 operating the 90 bars 50, 51 connected to the fields of transmitters A, E through differential gears 52, 53, being given a spiral motion by nut 48 which travels along cylinder 47, mounted on gear-wheel 46, when the handwheel 42 is turned, a pair of eliptical gears 45, 451, Fig. 3, being used in the train between hand-wheel 42 and nut 48 to maintain a uniform linear rate of travel of the beam. The binoculars 4 are moved with the box in azimuth and by handle 15 in elevation, the binoculars also being moved by the scanning and correcting devices through gearing 65, 66, 67 and 68, Fig. 5, for azimuth movement and through differential 74 for elevation. To apply correction due to movement of the target, the speed of movement of the locator is obtained electrically (as shown in Figs. 5 and 6) or mechanically (as shown in Fig. 7). As shown in Figs. 5 and 6 movement of handles 15 and 7 rotates discs 82, 82<1> so that the magnet systems are dragged round against the pull of holding springs 89, 90. The indicators are thereby moved through an angle proportional to rate of movement. Knobs 93, 93<1> are set to positions corresponding to the indicator readings and rack bars 61, 61<1> or similar linkage are moved correspondingly. Similarly, the slant range factor is introduced by cam 98, set from the elevational hand-wheel 15 through suitable gearing, and by the height setting introduced by knob 101 which moves rack 102. These two readings effect the setting of rheostat 111 which controls the current flow in magnets 81, 81<1>, &c. so that the setting of racks 61, 61<1> includes a slant range correction. A- mechanical correction apparatus is shown in Fig. 7 where the fans 170, 170<1> are driven by the handwheels through suitable gearing, the torques on the shafts 174, 174<1> being proportional to the fan speeds and movement of the shafts being opposed by flat springs 175, 175<1> which move between walls 177, 177<1> on the indicators. The position of the springs, and so the force exerted by them on the indicators, is controlled by the slant range mechanism 98, 103. To improve scanning at high angles of elevation, the scanning mechanism is modified as shown in Fig. 10 where the bar 50<1>, which introduces the azimuth scanning motion, is slidably mounted in bar 60<11>, the position of bar 501 being controlled by handle 181 which is set so that dial 182 indicates the proper elevation angle.