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).
The performance and adjustments of the Sequence Starter No.1 Scheme after modifications on chassis 9-EX.
| Identifier | WestWitteringFiles\Q\2-July1927-September1927\ 63 | |
| Date | 26th August 1927 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. E.{Mr Elliott - Chief Engineer} c. EY. Wor.{Arthur Wormald - General Works Manager} SEQUENCE STARTER NO.1 SCHEME. XJ650 As referred to in our EFC1/T8.7.27, we have removed from chassis 9-EX the starter with 34° 52' spiral with pinion operated switch, and replaced it by a 20° spiral with actuator box operated switch, a report on the functioning of which combination on the laboratory rig was given in the report above referred to. After preliminary adjustments there has been no actual failure of this arrangement on the car. A thump, though of reduced amount, is still produced on engagement and a follow up thump when rolling engine. The actuator box switch adjustment is such that contact is not made until nearly the completion of the travel of the actuator plunger. The contact lever spring has been set up by an approx. .025" packing under the clamping screws, the pressure on the contacts is rather larger and so that so that in the outermost position of the plunger the force between the contact lever and the plunger due to the lever spring is approximately such as to balance the force of the spring restoring the motor pinion along the spiral. Thus at the start of the plunger motion, there is no nett spring resistance, and this enables the full provided plunger travel to be utilised, thus eliminating any risk of failure of the start of this travel. It was previously reported, ref. EFC2/T6.12.26 in connection with chassis 14-EX that with a 20° spiral the teazer current would not wind the motor pinion into full engagement beyond the point where it was assisted by the Cont.d | ||