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 sequence starter to resolve backlash and switch contact issues.
| Identifier | WestWitteringFiles\Q\December1926-January1927\ 31 | |
| Date | 1st December 1926 | |
| To R.{Sir Henry Royce} from EFC. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. By.{R.W. Bailey - Chief Engineer} ORIGINAL EFC7/T6.12.26. SEQUENCE STARTER. x7650 x7620 x7650 a Further to our EFC2/T6.12.26, having rearranged the switch to just make contact before the actuator box plunger has finished its travel, we found that owing to the backlash effect between the flanges of the pinion unit and the pin of the lever of the switch, conditions were such that if failure of the engine to start should occur the contact of this pinion operated switch was not necessarily broken. This results in the motor running loose on again depressing the push button, because main switch operates and no volts exist for teazer circuit. We have, however, got over this entirely by fitting the pinion operated switch lever pin with a small collar which reduces the amount of backlash in the operation of this pin by the flanges. After making that alteration and re-timing the make of the switch contact, the apparatus has not failed to function over a large number of trials. Contrary to the impression that is probably given by my previous report, there still exists a thump on engagement, though it would appear that we have got rid of the follow-up thump when the motor is actually rolling the engine. We see no reason why this apparatus as now arranged should actually fail, and apparently the next step will be, when possible, to try out a similar arrangement with the 5° spiral in place of the 20° spiral. This we hope to do on the rig which is being prepared for us for the investigation of this starter. EFC. | ||