From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Use of two-way or four-way cams and a stationary contact maker for a magneto.
| Identifier | ExFiles\Box 36\3\ scan 029 | |
| Date | 11th May 1917 | |
| R.{Sir Henry Royce} 293(S). (S.C. 530. 15 3-16) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1546. Continued. 2. Cy R5/B11.5.17. 4 It would be as well to remember that there is still this way (4 sparks per rev) out of the difficulty by fitting a stationary contact maker on the lines of the one we have already arranged. X.2796 With reference to the sleeve type of magneto, it may be advisable to use either a two-way or a four-way cam on a countershaft above the magneto, in the same way as they have arranged a six or eight-way cam on the one sent to us. A slow speed contact maker shaft would be undesirable, owing to the errors of timing through very slight inaccuracies of the cam. At the same time, I should think that either two or four ways would be about the best possible number. A two-way cam would require to be driven (on a 2000 revolution engine) at 6000 revs., and a four-way cam at 3,000 revs. Such a revolving cam could however, probably be made very accurately. The make in this instance, could be slower than the break, as suggested for that of a revolving type of contact breaker. I shall want you to come back here as soon as convenient, so that we can work at the distributor for the camshaft. R.{Sir Henry Royce} (Contd). | ||