Méthode et appareil perfectionnés pour repérer la position géographique de corps en mouvement

144,628. Conners, W. W. June 12, 1919, [Convention date]. Course-recording apparatus. -Relates to a wireless method of determining the relative bearing of a transmitting and a receiving station, and hence when two transmitting stations are employed, finding the position of the receiving- station. This position is automatically shown on a map by a moving indicator, the movements of which may record a vessel's course. The principle of the method consists in sending out from each transmitting station a directive wireless beam which rotates through a predetermined arc at a uniform rate. Simultaneously non-directive radiations of a different frequency are emitted so as to indicate the times at which the rotation begins and ends. These times, together with the time at which the rotating beam crosses the receiving - station, serve to determine the bearing. Calibrating-means for checking errors are provided. The transmitting-station (not shown) comprises a coil rotated together with a commutator by clockwork, so that a directive beam of say 1200 metres wave-length is emitted in regular impulses and in a uniformly rotating direction while the coil turns through a predetermined arc, such as N-W-S, but the beam ceases to be emitted during the remainder of the rotation. A second commutator driven in unison with the former causes the precisely simultaneous emission from a non-directive or uniformly radiating aerial of waves of say 600 metres. The circuits of the receiving-apparatus are shown in Fig. 3, but amplifiers may be added to the apparatus shown. The circuits are so arranged (as described below) that the arm 88, Fig. 7, of the watt-meter 35 moves at a uniform speed clockwise from the moment that the non- directive waves are received by the aerial 16 until the moment that the directive beam crosses the station. The watt-meter 35 then ceases to register, and the arm of the other watt-meter 28 moves counter-clockwise until the non-directive radiations cease. The arms 88 are periodically depressed on to contacts 89 and the resistances 99 are such that when the above operation has taken place, the arms 88 have moved over complementary sections of their total range, and so co. operate to close the circuit of one of the magnets 93, which thereupon attracts a pointer to indicate the required bearing, since the movements of the two arms 88 are proportional to the arcs into which this bearing divides the total arc traversed by the rotating beam. Zeroizing means for the wa