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 fitting of a servo system for brakes, including servo drive and pull.
| Identifier | ExFiles\Box 22\1\ Scan102 | |
| Date | 11th February 1924 | |
| To RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} HS.{Lord Ernest Hives - Chair}} FROM R.{Sir Henry Royce} ~4214 SECRET. R1/M11.2.24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. X.9940 X.4214 BRAKES. I have not written much on the various brakes under discussion because I am expecting that we shall deliver nothing but slow speed servo, the advantage of which seems so astonishingly great. I am awaiting the decision of how this is to be fitted but to save time send the following comments :- SERVO DRIVE. I was surprised to find Mr. Rowledge had got a worm drive behind the box. If however it means moving the box or the sphere I think it would rule it out but if it goes in without any such change then it is good, except that I fear we cannot send out cars with a detached servo because it is now sufficiently built into the chassis. If however it can be made in a single casting completely carried by the box it would be passable, but would still leave an oil leak below the usual level. We know in any case there will be an extra oil leak but it should be at a higher level than the back and front ones. The trouble is that the gearbox oil froths up and runs out when one stops after a quick run. I am in hopes we shall find it more favourable to put in the internal worm, also using the double reduction which seems absolutely necessary. SERVO PULL. The pull from the servo will be a pretty severe contd:- | ||