Patent GB-226571-A (GB)
Title: Improvements in course indicators or recorders for moving vehicles
Filed: 1923-06-26
Abstract: 226,571. Grafstr÷m, J. S. June 26, 1923. Course - recording apparatus.-In apparatus for use on motor vehicles, and of the kind in which a map receives two component movements at rightangles to each other the resultant of these movements being proportional to the speed of the vehicle, end their relative magnitudes being controlled by the steering, the map is divided into a a number of strips mounted for longitudinal movement on laterally movable holders. As shown in Figs. 1<A>, 1<B> and 1<J>, the holders 3 are mounted on a number of parallel shafts K and are so shaped that they can all nest together at either end of the casing. Each holder is provided with two rollers 2, the map strip 1 passing from one of these rollers, around the holder 3 and back to the other roller. Each of the two sets of rollers is rotated from a pinion 10<1>, Fig. 1, through gear trains 8, 9, 10. The shafts K are threaded and are all rotated at the same speed from a pinion 27 through gears 25, 26. Each of the holders 3 is provided with a nut, which, in the end positions of the holders, is locked to the shaft K by a spring detent 20 passing through a hole in the nut and entering a depression 22 in the shaft. Each holder is provided with stops, one of which is engaged by the preceding holder when the latter reaches the middle of its travel so as to remove the detent 20 of the first-mentioned holder from its depression 22, and to cause it to enter between lugs on the holder which thus becomes locked to the nut to cause the holder to commence its travel along the shaft. The holders are thus moved in succession along their shafts. The means shown in Fig. 2 for rotating the pinions 10', 27 comprise friction discs 30 imparting rotation to rollers 15, 29 by means of balls 31 mounted in carriers 32 which can be displaced radially of the discs 30. The roller 15 is connected by gearing 14 to a shaft 13 carrying two conical drums a connected by stretched wires 11, 12 to the shafts b which thus rotate at continuously varying speeds for a constant speed of the roller 15, in order to compensate for the varying effective diameter of the map rollers and to produce a constant linear map-speed. The pinion 27 is driven by gearing 28 from the roller 29. The ball carriers 32 are mounted on T-shaped members 34 formed with slots 35, in both of which engages a pin 37 on a disc 38 driven by a roller 43 which is rotated through balls 41 from a disc 44. The ball carrier 42 is connected by a wire &c. 46 with a disc 47 connected to the steering-gear. The discs 30, 44 are driven at speeds proportional to that of the vehicle. For use on curves of large radius the disc 44 and roller 43 may be replaced by the arrangement shown in Fig 3A in which the driving disc 55 rotates two friction discs 52 geared together, one of the discs being geared to a shaft 61 which corresponds to the roller 43. In this arrangement the speed of the driven shaft is less as compared with Fig. 2 when the balls 41 are near the centre of the driving disc, and to compensate for this, means are provided whereby for a given angular displacement of the disc 47 the displacement of the balls is greater when they are near the centre of the driving disc. In a further modification the driving disc is made up of a number of annuli which rotate at continuously increasing speeds from the centre outwards.