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).
Schemes and ideas for a bi-directional servo braking system.
| Identifier | ExFiles\Box 73\2\ scan0257 | |
| Date | 5th February 1924 | |
| To HS.{Lord Ernest Hives - Chair} RG.{Mr Rowledge} from R.{Sir Henry Royce} c. to CJ. BJ. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} PN.{Mr Northey} S E C R E T. X9940 R1/1M5.2.24 E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. RE. BACKWARD BRAKING. X. 9940 Mr. Rowledge has sent me an idea for making the servo act both ways. I fear however any scheme which lets the brakes off before putting them on again could not be passed as sufficiently perfect. There are very many ways of doing this but I have not proposed to consider any of them good enough. Shunting here shews this to be true. One could not do with any slack backwards. Mr. Day will remember that we had also many ideas some quite of another order. One left everything say as Hispano, but had the extra virtue of the servo drum going forward always whether the car was going backwards or forwards. This scheme was to use extra gears and 2 ratchets. I would like to know if it was patented, or if someone less interested than I, say Mr. Bailey, will say if it is worth patenting. I think I suggested spur gear, epicyclic, and external and internal gears the latter like the sketches shewn. Some further light has come on this scheme which is (1) that the second reduction is an advantage, (2) that the forward servo speed might be much slower than the backward, i.e. a 40 to 1 ratio, (3) and that 20 to 1 might be used. There were many points and possibilities about this scheme, (but like such schemes we considered they seemed either complicated or imperfect) for instance - (1) the idling ratchet may not make a noise in oil yet work quite quickly enough for a reverse, (2) positive ratchets may be contd:- | ||