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).
Alterations to an ignition switchbox and an alternative proposal.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan146 | |
| Date | 1st March 1924 | |
| SECRET ORIGINAL EL/M17. 3. 24. 2- TO BY: FROM E.{Mr Elliott - Chief Engineer} Copy to - GI RS{Sir Henry Royce's Secretary} EFS E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. EFC. LIGHTING & IGNITION SWITCHBOX. X 9730 We send you herewith drawing No. LeC. 1849, shewing the standard switchbox altered for 2 ignitions. There are 4 positions of the ignition switch reading - 'Off', 'B', 'B.M.& C', 'M & C', thus arranged to give both ignitions or either. An alternative arrangement is also shewn reading - 'Off', 'B', 'B & C', 'M & C'. This should be suitable for Goshawks, and also as a policy for preventing detonations on EAC. chassis with ordinary magneto if ignition plugs not in operation do not foul. The switchbox thus arranged requires a new bakelite moulding for the base. The locking bolt has been inclined to one side of the centre line, as also the rockers for the positioning cams. These alterations, together with a reduction in the angular pitch of the switch movement from 45º to 40º enables the extra position to be got in on the ignition switch. The pitch of the screw holes in the brushes is correspondingly reduced from .312 to .275. The number of studs securing the rear cover and the moulding has been reduced from 4 to 3. Mr. Royce has proposed an alternative to this scheme on which we are now working, in which the present ignition switch is a master switch switching the ignition 'On' and 'off', while the changeover of the ignitions is effected by a small barrel switch at the top of the box. We are not sure but this letter will be preferred, and we are therefore sending you LeC. 1849. so that you can proceed to make up a model of this box if thought advisable. Would you kindly send this drawing to Mr. Rowledge, or send him a blue print for his inspection. E.{Mr Elliott - Chief Engineer} | ||