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 laboratory testing of two different sequence starter main switch units, comparing different thicknesses of copper contact laminations.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan012 | |
| Date | 2nd December 1930 | |
| R.{Sir Henry Royce} from EFC. c. Sg.{Arthur F. Sidgreaves - MD} c. By.{R.W. Bailey - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} ORIGINAL EFC3/AD2.12.30. X.7655. SEQUENCE STARTER MAIN SWITCH UNIT TO LeC.2804. Two of these units have been made and duly tested in our experimental laboratory previous to putting these on cars, both of these being fitted with the thickest carbon arm flat spring D.72922 which we suggest is the best of the two alternatives provided on the LeC. One switch is fitted with copper contact laminations of 28 SWG. and the other with some of 26 SWG. The latter thickness is considered to be the better of the two and is on the switch which has been fitted to chassis 27-EX. Both by chronographic record test and by condenser and galvonometer test we have proved that the carbon contacts are now definitely making first when the switch is normally operated. This is also the case when voltages reasonably above and below normal are tried. Further, both switches easily passed our standard production test with a considerable margin. The switch which has not so far been on a car for test, is undergoing an endurance test on our crankshaft starter rig in our laboratory. EFC. | ||