GB1227724A - - Google Patents

Abstract

1,227,724. Aerial observation system. COMPAGNIE FRANCAISE THOMSON HOUSTON-HOTCHKISS BRANDT, and GIRAVIONS DORAND. 31 Jan., 1969 [1 Feb., 1968; 26 Dec., 1968], No. 5450/69. Heading B7W. [Also in Divisions G3 and H4] An aerial observation system (for example employing radar) has a ground station II and an unmanned airborne station I<SP>1</SP> of helicopter form hovering over it, the airborne station consisting of a supporting section 101<SP>1</SP> powered by rotor tip jets 108 and a supported section 102<SP>1</SP> suspended so as to be swingable and able to be rotated about a substantially vertical axis by means of vanes 129 on the supported section which are in the rotor jet stream, in order to scan the surrounding space, and a radio system which transmits the results of the scanning to the ground station, the ground station having a tracking radar which detects deviation of the airborne station from a predetermined position and supplies correction signals via the radio system (Division G3). In a first embodiment, Fig. 2, a supporting section 101 carries a gyrostabilized body 104 rigid with a shaft 105 pivotally attached by a ball joint 124 to the supported section 102 in which a plate 119 is connected via a parallelogram linkage 121, 122, 123 to a plate 120 attached to a nacelle 125. The nacelle 125 contains a unit 130 housing the observation and control equipment and also supports compressors 140 which supply air to the rotor tip jets. If power should fail descent of the craft will cause blades 107 to rotate in reverse and drive an auxiliary generator 145 which will keep working at least the gyroscopic stabilizer 104 and the radio system. The airborne station may land on a special mobile platform 146 which is able to rock and rotate. In an alternative embodiment, Fig. 5 (not shown), ball joint 124 is dispensed with so that the shaft (118) supporting the rotor is rigid with plate (119) and the nacelle (125) is suspended swingably from plate (120). A plumb detector (172), Fig. 7 (not shown), is suspended inside a hollow shaft (159) supporting the nacelle so that when the nacelle is not hanging vertically the plumb touches conducting segments (174) on the wall and closes a circuit which activates jacks (162x, 162y) to restore the shaft (159) to the vertical. Two airborne stations are generally employed to enable continuous surveillance of the surrounding space with alternate ground servicing and refuelling. The rate of scan is followed by a monitoring receiver 154, Fig. 3, on the ground and is fed into a computer 43 which transmits corrective signals to a governor 17 which controls the angle of flaps 129 to correct the speed of revolution of the nacelle.