Patent GB-415201-A (GB)
Title: Improvements relating to searchlight control systems for locating aircraft
IPC: F21V21/00
Filed: 1933-04-07
Abstract: 415,201. Controlling searchlights. SPERRY GYROSCOPE CO., Inc., Manhattan Bridge Plaza, Brooklyn, New York, U.S.A.- (Assignees of Bassett, P. R. ; 104, Broadway, Rockville Center, and House, F. R. ; 4, Hayes Street, Baldwin Harbor, both in New York, U.S.A.) April 7, 1933, No. 10460. Convention date, May 16, 1932. [Class 75 (iii).] In a system for locating aircraft at night in which a searchlight is adjusted to any desired position, means are provided for superimposing a further movement to cause the searchlight to scan a predetermined area around said position to pick up the target. In one arrangement, Figs. 1 and 5, the angular positions in azimuth and elevation of a sound locator L, corrected as described in Specification 412,267, [Group XXXVIII], are transmitted electrically to repeater motors 17, 18 controlling dials 11, 12 of a comparator 10, from which the searchlight S is controlled through transmitters 45, 45<1> and repeater motors 97, 97<1> by operating handwheels 13, 15 to move pointers 14, 16 to match pointers on the dials 11, 12, two right-angular components of a spiral scanning movement being introduced through differential gears 20, 21<1> by operating a handwheel 44. The scanning mechanism, Fig. 3, comprises rack bars 27, 29 pivoted to a pin 30 on a block 31 reciprocated by a pin 34 engaging a double endless spiral groove 33 along a shaft 32 rotated through gearing 37, 38 by the handwheel 44, the bracket 35 being simultaneously rotated with the shaft 36. A pin 42 snaps past a spring 42<1> when the pin 30 is at the origin of the spiral movement. Automatic driving means may be used instead of the handwheels 13, 15, 44. Transmission of the scanning movement to the pointers 14, 16 is prevented by interposing further differential gears 21, 21'. The scanning mechanism may be cut out by pulling out shafts 24, 24<1> by means of the knobs 47, 47<1>. A sighting telescope or binoculars 65 may be provided on the comparator to follow the searchlight beam, the binoculars moving in azimuth with the comparator, which is carried by a gear 66 on the tripod controlled from the handwheel 13, or 13<1>, and being controlled in elevation from the handwheel 15, or 15<1>, by means of a flexible shaft 73 and worm gearing 74, 75 operating linkage 70<11>, 71, 69<1> carrying the binoculars. A platform movable in azimuth with the comparator may be provided for the observer. When the target is sighted, the observer may release the handwheels 13, 15, 44 and assume direct control of the searchlight through handwheels 13<1>, 15<1>. By pushing in knobs 54, 54<1>, clutches 52, 52<1> may be disengaged from gears 50, 50<1> and engaged with gears 61, 61<1> on sleeves 59, 59<1>, which are thereby disengaged from gears 57, 57<1>, so as to disconnect the handwheels 13, 15 and allow for control of the searchlight by the handwheels 13<1>, 15<1> without operation of the pointers 14, 16 or the binoculars. In a modification, Fig. 6, adjustment of the searchlight in azimuth and elevation is effected automatically by means of reversible motors 87, 87<1> which operate transmitters 96, 96<1> controlling the motors 97, 97<1>, the components of a zig-zag scanning movement being introduced through differential gears 89, 89<1>. The motors 87, 87<1> are operated through reversing controllers 83, 83<1> by the motors 17, 18. The scanning mechanism comprises gears 91, 91<1> operated by a worm shaft driven by a motor 98 or a handwheel 99, the gear 91 reciprocating a connecting rod 92 while a toothed eccentric 100 on the gear 91<1> rocks a pivoted lever 101.