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).
Cost-saving modifications to the Phantom III main starter switch.
| Identifier | ExFiles\Box 168a\2\ img285 | |
| Date | 15th April 1937 | |
| from HPS.{Horace Percy Smith - Experimental Factory Mgr} c. to Rm{William Robotham - Chief Engineer}/Wst. HPS.{Horace Percy Smith - Experimental Factory Mgr}2/VS.{J. Vickers}15.4.37. PHANTOM III MAIN STARTER SWITCH. We are sending herewith for your examination a Phantom III main starter switch which T. Tooby has modified with a view to reducing the cost of manufacture, together with a standard switch for the purpose of comparison. Several expensive features on the standard switch have been deleted, and the modified version should be very much cheaper to produce; furthermore, being of a more straightforward construction can be assembled with a minimum of skilled labour. The following are the principle features upon which it is claimed a saving has been effected :- 1. Resistance coil D.180412 deleted. Resistance winding incorporated in main coil. 2. Magnet yoke D.100325 simplified to facilitate manufacture and produced in mild steel instead of Swedish iron. 3. Core of main coil rivetted into magnet yoke, thereby deleting the screwing on the core and retaining nut. 4. Carbon contacts and armature assembly deleted and copper contacts simplified. 5. Carbon contact support D.71726 deleted. 6. Number of screws reduced to a minimum and rivetting employed wherever possible. The principle alteration to design is the deletion of carbon contacts, and whilst this step may possibly be criticised from an electrical standpoint, it is considered that carbon contacts are an unnecessary refinement and that the resultant saving in cost on the mechanical features of the switch justifies this departure from accepted R.R. practice. Furthermore, in view of the fact that the majority of presentday switches, including those produced by Lucas for continued. | ||