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).
Design and testing of a four-wheel brake servo system, designated DES.60.
| Identifier | ExFiles\Box 73\2\ scan0282 | |
| Date | 1st March 1924 | |
| R.{Sir Henry Royce}(at Le CanadelHenry Royce's French residence) C.L/S.F. [Struck through] C. H.S. [Struck through] C. Hoyes [Struck through] C. Hs.{Lord Ernest Hives - Chair} SECRET X9940 Rg{Mr Rowledge}3/W10. 3. 24 FOUR WHEEL BRAKES. With regard to DES.60, we are adopting this designation in future to refer to the scheme which servos equally when moving backwards and forwards. This scheme is now rigged up on a chassis and works both backwards and forwards without any lag that can be felt. The foot pressure required is very light. The cone angle of 20° that I adopted is a little too flat, and gives one the impression that it is going to stick in, although it does not quite do so. We are altering the angle to 30° to correct this point. We are also putting in a third stay between the two castings. The fact that the servo works in both directions is a distinct advantage over the Hispano, and I think the scheme is clear of the Hispano patent. The first chassis fitted with the agreed scheme will be completed tomorrow, and one should be able to be sent down to you leaving here in about ten days time. Perhaps you would also like the chassis fitted with scheme DES. 60 sent down at the same time? Rg.{Mr Rowledge} | ||