Patent GB-464354-A (GB)
Title: Electric position finding systems
IPC: G01C3/06
Filed: 1935-10-14
Abstract: 464,354. Position finders. ATAKA & CO., Ltd. Oct. 14, 1935, No. 28340. Convention date, Oct. 31, 1934. [A Specification was laid open to inspection under Sect. 91 of the Acts, April 20, 1936.] [Class 97 (i)] [Also in Groups XXXVIII and XL] Apparatus for determining the position of a body such as an aeroplane comprises two sighting telescopes, at the ends of a known base, provided with synchronously rotating means whereby each telescope is caused periodically to provide an electrical impulse the phase of which is determined by the direction of the line joining the telescope to the said body ; and a single indicator, at a known position in relation to the receivers, provided with concentric circular neon &c. lamps energized by the said impulses and with a disc rotating in synchronism with the rotating means at the telescopes. The disc has a single radial slot through which the neon lamps are observed, so that by persistence of vision two stationary points of light are seen through the slot, the directions of the radii joining these points to the centre of the disc being parallel to those of the lines joining the observed body to the respective telescopes. As shown in Figs. 4 and 5 the telescope at each of the stations A, B is adjustable about horizontal and vertical axes 18, 19, and electric interrupters 26, 27 rotated by synchronous motors 24, 25, are associated with the adjustment axes, the housings of the interrupters sharing the movements of the telescope so as to adjust the point at which contact is broken. The interrupters 21 control neon tubes 6, 61 at the indicator and a disc 5 rotating above the tubes synchronously with the interrupters has a radial slot 8 through which the tubes are observed. A triangle a<1>b<1>c<1> similar to the triangle ABC is adjusted above the disc until the points a<1>, b<1> lie on the radii along which the neon tubes are seen. The line Cc<1> then coincides with the horizontal projection of the line CO and represents to scale the horizontal range of the observed object. To determine the height of the object O and its angle of sight from the point C, the indicator is provided at its centre with a post 31, Fig. 7, on which is slidably and rotatably mounted a telescope 32, the inclination of which to the post can be varied. The telescope is adjusted so as to be inclined to the post at an angle equal to the angle of elevation of one of the observing telescopes and is then adjusted vertically and about the post 31 until it is aligned on the corresponding point, say a<1>, of the triangle a<1>b<1>c<1>. The telescope is then adjusted about the post 31 and as regards its inclination thereto until it is aligned on the point c<1>. The angle Y is then the angle of sight of the object and the vertical position of the telescope on the post represents to scale the height of the object. The Specification as open to inspection under Sect. 91 describes also the apparatus shown in Fig. 2 (Cancelled) for finding the position of a source of light &c. This apparatus comprises receivers consisting of photoelectric cells a, b mounted in casings 1, 11 rotating in synchronism and provided with apertures 2 21 on radial lines parallel to each other, so that each cell is illuminated when it is in alignment with -its aperture and the source O. The photo-currents are utilized by means of amplifiers 10, 10<1> and transformers 9, 91 to energize the neon tubes 6, 6<1> at the indicator. This subject-matter does not appear in the Specification as accepted.