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).
Secret memorandum detailing the design and operation of a new starter system.
| Identifier | ExFiles\Box 64\1\ scan0168 | |
| Date | 1st January 1924 | |
| TO RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} & DA.{Bernard Day - Chassis Design} FROM R.{Sir Henry Royce} Copy to CJ. BL. WOR.{Arthur Wormald - General Works Manager} EPG. HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} x7620 S E C R E T. R3/M1. 1. 24. E.A.C.1 & 2. RE. STARTER. x7620 x965D SYSTEM. You will remember that we are fitting our own RR. system of sequence silent press button type as we want this to take up the drive more silently and detach itself quietly independent of the skill and care used with the press button. MOTOR. This is smaller than the present 40/50 but is also double geared. It has two field windings - a fine one for motoring at about 10 amps. giving a strong magnetic flux to make the motoring certain, and it is about the winding of the various control units that I write this memo. ACTUATING MAGNET. This is in series with the fine winding on the motor fields and should be tested experimentally with the same section of copper. It must act vigorously and the only limit of fineness of wire is its own heating or the reduction of the motoring current, but I think it will be found about right if made as indicated above. MAGNETIC MAIN SWITCH. This has the full 12 volts upon it alone but is only on for a short time. It might be tried with a winding that would permit of 4 amps. to pass. This would be roughly 3 ohms. This circuit is made and broken by the contact worked by and on the actuating magnet. It should have a non-inductive resistance in parallel so as to reduce the sparking at these contacts to the point of being non-destructive. Such a non-inductive resistance might be tried of about 20 ohms. PRESS BUTTON. This is another part at which sparking occurs and should be protected by carbon break like the main and hold off switches. I am desirous that this press button should be on the instrument board. I do not quite like kicking at it on the dash. There are too many false contacts and breaks made by the foot. HOLD OFF SWITCH. After the actuating switch has done its work of engaging the pinion and making the contact which causes the main switch to close, its circuit is then broken by this apparatus which is the very special feature of our system. In the latest scheme we have arranged that the magnet for this shall be excited by the rush of main current going to the motor, and the winding should have a section about equal to the coarse series winding on the motor - i.e. giving about equal current density. (1) | ||