GB525812A - Improvements in and relating to course-indicating apparatus for vehicles - Google Patents

Abstract

525,812. Course-indicating apparatus. HARGRAVE, J. G., and WILLIAMS, D. C. Nov. 29, 1938, No. 34776. [Class 97 (ii)] In an automatic course-indicating apparatus for vehicles operating by light transmission by which a map &c. of the course mounted to move in its own plane in two directions mutually at right angles can be reproduced on a screen by projection or reflection the means carrying the map &c. is constructed and mounted so that the setting or direction of movement relative to the vehicle and preferably the means for imparting such movement are controllable by a gyroscope and the means for imparting a movement of progression to the map &c. comprises a motor the speed of which can be regulated in accordance with the progression of the vehicle. A toothed ring 11 mounted in ball bearings in the aircraft and kept in fixed orientation by a gyroscope 10, gears with a gear 12 having a shaft 8 mounted in bearings 13 in a casing 14 fixed relatively to the aircraft. Deviations from the straight course of the aircraft therefore cause the gear 12 to ride round the ring 11 and rotate the shaft 8 either directly or through a servo-motor 9. Mounted within the casing 14 is a turntable 15 which is rotated in accordance with the rotations of the shaft 8 by gear 49. A slide 17 is mounted on the turntable 15 so as to be able to move transversely by means of rollers 18 and guide 19 and, at the other end, by bearings 22 slidable over a rod 21. The longitudinal movement comprises mounting the map &c. 30 on the slide 17 so as to be capable of movement on and off rollers 23, 24. The turntable 15, by means of a bracket 31, carries a motor 32, the speed of which can be regulated, automatically or otherwise, in accordance with the speed of the aircraft. The motor 32 drives through reduction gearing a progress wheel 35 bearing on the upper roller of a pair of rollers 26 gripping the map &c. As shown, the motor is an electric one and is driven by means of brushes 33 and contact rings 34 and is arranged to drive in one direction only. In order to obtain the requisite movement of the map both transversely and longitudinally the progress wheel 35 is arranged so that it can be angularly displaced in the horizontal plane and for this purpose a toothed annulus 36 carried by the casing drives through gearing 37 ... 39 a gear 40 carried by the motor casing the progress wheel 35 being carried by a shaft diametrically carried by the gear 40. The image of the course is projected on the screen 47 and is arranged to move downwardly thereon. As shown, the light from a source 44 through condenser 45, to reflector 43 and thence through map 30, and lens 42, to reflector 46 and to screen 47.