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 tungsten, interchangeability of contact breaker points, and the design of contact makers for battery ignition systems.
| Identifier | ExFiles\Box 163\7\ img097 | |
| Date | 23th February 1927 | |
| 1 Copy to O.E.C.S. VID 2 Copies To EFC. Hs.{Lord Ernest Hives - Chair} } FROM R.{Sir Henry Royce} 1 Copy BY 1 Copy to O.E.C.S. } At Le CanadelHenry Royce's French residence. C. BJ. Wor.{Arthur Wormald - General Works Manager} RG.{Mr Rowledge} DA.{Bernard Day - Chassis Design} BATTERY IGNITION X.4041. X.1818 LIFE OF CONTACT BREAKER POINTS. X.4652. X.2894. REGARDING POINTS. I hope it will have been settled that we can use tungsten. I fear however we cannot make the parts interchangeable with Delco. Can we use the superior (?) American points ? I suggest a fairly large supply of known good tungsten points from whatever source. Is American Bosch interchangeable with Delco ? If not would it be easier to make ours interchangeable with American Bosch. REGARDING CONTACT MAKERS. It is understood we are now OK. on oil trap, ventilation, etc. I cannot believe that if the off-set only alters the rate of break and make by 8% that this can have any serious effect. I can see that we ought to test with break set at such a distance as to give the most rapid break. If a sine curve then this would be half the stroke. Supposing we test with 3 lengths of break and timing (duration) finding if this makes any difference to life, and compare with Delco and Bosch. I think we should make a cam which with or without off-set effect will give about 50% quicker break than make. The duration of make would be expected also to have an effect on the life of the contact points. I am continually hammering at this feature with the hope of some definite progress, but it is a slow job in face of the fact that we have something better to compare with. Are Delco and American Bosch any different in the life of points ? | ||