| 摘要 |
375,887. Leader gear for assisting navigation. SOC. INDUSTRIELLE DES PROC•D•S W. A. LOTH, 20, Avenue Kleber, Paris. April 7, 1931, No. 10261. Convention date, April 9, 1930. [Class 40 (v).] For defining the position of an aerodrome, differing electromagnetic fields are produced outside and inside the aerodrome and a further field inside the aerodrome detectable only below a certain height. The emitting plant comprises an A.C. generator 3, Fig. 4, feeding cables a, b<1>, b<2>, c, d arranged on the landing ground, through a rotating distributer 6 shown developed. The height indicating radiation is produced by the conductors c, d of which only two are shown and which are arranged at ground level, the conductors preferably being buried. Alternate conductors are fed in the opposite direction to produce a field rapidly decreasing with height. To produce different signals inside and outside the aerodrome the direction of current in the conductor a is reversed periodically relative to that in conductor b<1>, b<2>, e.g. so as to produce dots outside and dashes inside the cables, by means of the distributer 6. As shown, the " dash " signals inside the aerodrome are produced during the movement T of the distributer, the dot " signals outside together with the " dot signals from height indicating cables during the movement P and for the movement D, the cable a only is energized to produce a signal of greater range than any of the others. At the receiver, Fig. 5, a horizontal and a vertical frame aerial, 7 and 8 respectively, are alternately brought into operation by an oscillating valve 9 and feed a detector 10 and amplifier 11, the frequency of the oscillator 9 being such as to render the signals audible if their frequency is above audibility. The vertical frame may be used to find the direction of the centre of the aerodrome. The receiving means may act automatically on the steering member of the moving vehicle. |
