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).
Starter motor troubles for the Phantom III, focusing on stopping mechanisms and safety features.
| Identifier | ExFiles\Box 91\1\ scan0469 | |
| Date | 12th January 1937 | |
| 300 Rm{William Robotham - Chief Engineer}/Wst. Ey/RD. } from E.{Mr Elliott - Chief Engineer} E.1/HP.12.1.37. C. Sgr-Hs{Lord Ernest Hives - Chair}; Rm.{William Robotham - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} HPS.{Horace Percy Smith - Experimental Factory Mgr} Phantom III Starter. This confirms discussion of Rm{William Robotham - Chief Engineer}/Wst. Ey/RD and E.{Mr Elliott - Chief Engineer} of Saturday morning, 9th inst. concerning the Phantom III starter troubles. (1) Stopping motor with repeated operation of starter button. (a) on 33*35 A scheme for incorporating a friction disc in the motor has been issued (a) with a Ferodo disc rivetted on to the tail bearing retaining plate. (b) with inserted corks in the retaining plate. (b) In America for 36-37G We hope this is all that will be necessary, and as drawn the scheme is applicable to existing production by boring out the end bracket about .125 increased diameter. Rm{William Robotham - Chief Engineer}/Wst. has made a test which shows that the motor armature can be stopped in half the time by allowing the existing pull off spring to draw the armature endways against a friction disc. This scheme has to be fitted in conjunction with cancelling the pneumatic damper in the disengaging direction which can be done very simply by drilling a ventilation hole. It is hoped that this will not cause any noticeable thump which is apparent in the body and also a certain amount of cushioning is provided particularly with the cork scheme. We may in time be able to delete the present standard pneumatic damping device entirely with consequent saving in cost and bulk, but cannot take this step until sufficient investigation and testing has been done. (2) Safety scheme to prevent use of starter with engine running. Either of the schemes under review require a small automatic switch fixed to the starter motor. In the first scheme the contact points of the safety device | ||