Patent GB-190701387-A (GB)
Title: Improvements in Apparatus for Automatically Recording the Periods of Action or Speed of Vehicles, Steam Ships, Machines and the like.
Inventor: HADDAN HERBERT JOHN
Filed: 1907-01-18
Granted: 1908-01-18
Abstract: 1387. Haddan, H. J., [Defauconpret, C. A.]. Jan. 18. Speed indicators; revolution. direction indicators. -Relates to apparatus for automatically recording the periods of action both backward and forward, and of rest, and the speed of vehicles, steamships, machines, &c. by means of zigzag curves traced upon a clock-driven disk by a recording- pencil. A worm 4, Figs. 1 and 2, driven by a convenient-rotating part of a machine &c., operates through a worm-wheel 5 a shaft 5<a> to which are keyed ratchet-wheels P, R. In one direction of rotation of the shaft 5<a>, the ratchet-wheel P turns the sheave of an eccentric 7 by means of a pawl V fixed thereto, while a pawl Q attached to the sheave of an eccentric 8 slides over the teeth of the ratchet-wheel R. In the other direction of rotation, the ratchet-wheel R operates the sheave of the eccentric 8 through the pawl Q, while the pawl V slides over the teeth of the wheel P. In either case, the eccentric that is not operated by the ratchet-wheels is held stationary by being suitably braked, or by means of ratchet-wheels and pawls (not shown) fixed to the eccentric sheaves and straps, respectively. The eccentric rods 7<a>, 8<a> are thus reciprocated in turn according to the direction of travel of the vehicle, and the carriage 6 which carries the pencil 2 is given a reciprocating movement by means of a lever 14. The eccentrics 7. 8 are of unequal throws, and thus the periods of forward and of backward action are distinguished by zigzags of different amplitude on the record disk 3, periods of rest being recorded by a simple curve. To allow a lengthy record to be made on the disk, a slow continuous radial movement is given to the pencil carriage, thus producing a spiral diagram. The forked arm 9 of a doublearmed lever 9,10 engages a pin on the carriage, while a finger 12 on the arm 10 is pressed against a clockdriven cam 12<a> by a coiled spring 13. By increasing the speed of rotation of the disk by means of a suitable speed-changing mechanism (not shown), operated by the lever 15, so that the number of oscillations recorded between any two divisions may be counted, the apparatus serves as a speed indicator. When the lever 15 is pushed inwards, it is caused by a pin 16 working in the A-shaped groove 17 to operate the cord 24 passing over pulleys 23 carried by pivoted sector plates 21, 22, and thus to bring the pivoted spring-controlled pawls 24<a> into operative engagement with the spring-controlled ratchet drum 19. The rotation of the drum winds up the thread 25 attached to the arm 10 of the lever 9, 10, causing a sudden oscillation of the pencil carriage ; the moment at which the speed of rotation of the disk is changed is thus recorded as at 28. The record disk can be returned to zero by rotating the winged nut o<1>, the proper setting being determined with the aid of the fixed pointer f<1> situated in a known position with regard to the pencil, as the point of the latter is not visible.