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).
Modifications to a switch, discussing magnetic traction, contact pressure, corner jams, and gear noise.
| Identifier | WestWitteringFiles\T\2January1929-June1929\ Scan259 | |
| Date | 4th June 1929 guessed | |
| -3- contd. uniformly perfect, this however, remains to be seen. On the whole so far, these contacts have not done badly. As a result of certain minor electrical and magnetic modifications which we have made to the switch, of nature called for by consideration of the principles involved, we have now a very good margin of magnetic traction so that we have been able to allow a big copper (and carbon) contact pressure and still pull the armature right down to the stop. We have not been able entirely to eliminate the possibility of a corner jam on first application of current. Experiments on various forms of teeth however indicated that, beyond the definite advantage apparently made by backing off the tops of teeth, the question of sharp or rounded engaging corners makes no vital difference. These two cases, in fact, appear to be equally good, or bad. Also we still have with us a certain amount of gear noise both when rolling the engine and in dis-engaging. The power of the motor is agreed now to be very good. We hope shortly to issue some approved curves of performance of the motor as now arranged. It is sometimes considered that the fact that the push button cannot be accidentally pressed without noise when the engine is running, is a dis-advantage. It does occasionally happen that the engine, though contd | ||