Improvements relating to Ignition Devices for Internal Combustion Engines

110,613. Markham, R. G. L. Oct. 28, 1916. Dynamos, driving. - An ignition magneto or dynamo is driven through a coupling of the kind in which the driven membar is arrested during part of each revolution and then released and driven by a spring to produce a retarded and intensified spark. A driving plate 3 on the engine shaft 1 is connected to a plate 4 on the magneto shaft 2 by coil springs secured to studs 5, 5 on the plate 3 and to pins 8, which pass through slots in the plate 4 and are screwed into a friction plate 16. The arrest and release of the plate 4 are effected by a lever 13, Figs. 1 and 4, carrying a roller 11 and a pawl 12 held in engagement with the peripheries of the plates 3, 4 by a spring 21. Once or twice in each revolution, the pawl 12 drops into a notch 10, Fig. 3, in the edge of the plate 4, arresting the plate until thrown out by the engagement with the roller 11 of a projection un the plate 3. The plate 4 is then driven sharply forwards by the springs. When the magneto is running quickly, the arm 13 is thrown out of operation by cams 24 on the plate 4, and is then held out by the spring 21 or by a catch. In order to allow the relative position of the plates 3, 4 to be varied, the stud 5 on the plate 3 projects through a long slot 19 in the plate 4 and a shorter slot in the plate 16.