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).
Investigation into the occasional failure of a sequence starter, exploring issues of jamming and teazer current.
| Identifier | ExFiles\Box 64\3\ scan0081 | |
| Date | 17th August 1926 | |
| To R.{Sir Henry Royce} from EFC. C. E.{Mr Elliott - Chief Engineer} Hs.{Lord Ernest Hives - Chair} X7650 EFC2/T17.8.26. RE SEQUENCE STARTER. X7650 X7620 In answer to your RL/M13.8.26, we had already investigated the starter on the lines you suggest so far as is possible in position on a car, and using 12 volts only, and it has now been suggested that we have this fitted up on an engine where inspection of the operation is more possible. Failure to operate had only been quite occasional but when it had occurred it had been complete and necessitated the use of the starting handle to move the engine before the starter could again be used, or alternatively, making the main heavy current circuit manually on the main switch. As far as we could judge from the trials, it was as if a partial jam had occurred, i.e. it was such that no ordinary increase of the teazer torque would clear it, though it was quite true that the application of the main current would do so. It was thought by us previous to being assembled on the car that the teazer current, even with the increases we had made, might still not, under the most unfavourable conditions, be sufficient to turn the motor. This, however, has not so far proved to be the case apart from the jam. Naturally, when we experienced the failure we at first thought it was due to this cause and we therefore experimented on the lines of increasing the teazer current by gradually shunting and finally entirely short circuiting the actuator box solenoid, but without making the motor budge. This would have put up the teazer current considerably, and at the same time relieved the Contd. | ||