GB466101A - Improvements in or relating to apparatus for indicating the average speed of a vehicle - Google Patents

Abstract

466,101. Indicating-apparatus; speedometers. THIBOUST, L. Oct. 19, 1935, No. 28934. Convention date, Nov. 2, 1934. [Classes 106 (iii) and 106 (iv)] Apparatus for indicating the average speed of a vehicle comprises parts driven in accordance with elapsing time and with distance to vary the slope and position respectively of a line which, by its intersection with an evenlydivided scale, indicates the required average speed. The principle underlying the invention is shown in Fig. 2. A scale B is graduated in kilometres (0.. 500) and in hours (0.. 5). If a distance of 300 kilometres is travelled in 5 hours, and if a sliding member A is set adjacent 300, then the point of intersection of a scale on the member A with a line joining a point O to the 5 hours graduation of B gives the speed, viz. 60 kilometres per hour. Had the distance of 300 kilometres been traversed in 4 hours, the line 0-4 hours, at its indication with the scale on the member A, would have indicated the speed of 75 kilometres per hour. In a practical embodiment, Figs. 5 and 6, a shaft 8 is rotated according to distance travelled and has secured to it discs 5, 6 and a clockwork mechanism 9. The clockwork drives a plurality of internallytoothed rings 2 through gearing 10, 11, 12. Each ring is driven at a slightly faster rate than the ring to the left of it, the direction in all cases being opposite to that in which the whole arrangement is moved by the distancecontrolled device. Each ring has a mark 1 upon it, these marks initially forming a straight line. As the clock drives the discs, the line becomes helical as shown. The average speed is given by the point of intersection of the line with a fixed evenly-divided scale 25. The discs are reset by turning knurled wheels 16, 21. Contacts on the rings 5, 6 may be arranged to open a clutch between the clockwork mechanism and the rings at the expiration of a certain period. The Specification as open to inspection under Sect. 91 refers to (but does not fully describe) apparatus in which the slider A of Fig. 2 is replaced by the rotating radius of a circle inside which are drawn curves corresponding to the lines OB. This subjectmatter does not appear in the Specification as accepted.