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 discussing the advantages of a modified semi-servo brake system over other patents and previous designs.
| Identifier | ExFiles\Box 22\1\ Scan122 | |
| Date | 1st March 1924 | |
| 4214 To DA.{Bernard Day - Chassis Design} & HS{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} c. to CJ. BJ. Wor.{Arthur Wormald - General Works Manager} RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} Mr. Claremont. S E C R E T. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. RE BRAKE SYSTEM. R1/M.3.24. X.9940 X.4214 For various reasons and principally to avoid the Hispano and other patents I have recommended the system of modified semi-servo as by telegram. The more I have thought of this the better it seems and possibly more desirable than any other we know, because :- (1) It is self evident and simple. (2) It involves little or no change from the schemes in hand. (3) It seems superior for shunting and backward braking. (4) The servo can be used through an angle of 75° to 90°, all of which can be used for taking up the slack in the brakes, putting on the brakes, (spring) and wear, thus making the duty lighter, the working cooler, and the taking up more gentle. Friction etc. will therefore be about a quarter that of the Hispano. At the moment I do not know any real disadvantages. It is a little like the early servo idea with the hand brake supplementing, but instead it has the foot pressure supplementing automatically. I am hoping that Hs.{Lord Ernest Hives - Chair} is trying to rig this up temporarily, but of the correct proportions, with the help of RG.{Mr Rowledge} Also to hear that the committee at WW. and RG.{Mr Rowledge} approve of testing it in preference to anything else. Also to hear that Mr. Claremont thinks it good to avoid other patents and create our own scheme. Before making up your mind that it has faults remember that our original semi-servo had the following disadvantages :- (1) Foot did three eights of the work direct on a separate pair of wheels. (2) Any slight variation in a good servo now only affects a small amount of the proportions - three quarters being contd:- | ||