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).
Tests carried out to eliminate servo brake clanks, in response to a letter from Mr. Olley.
| Identifier | ExFiles\Box 16\3\ Scan063 | |
| Date | 18th September 1929 | |
| To Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} from G.W.H. GWH.{George W. Hancock - Head Chateauroux}1/MJ18.9.29. Tests carried out to eliminate Servo Brake Clanks in answer to MR. Olleys letter of the 19.8.29. In dealing with this problem, the first feature to be settled is, at what speed is the foot brake to be released, as upon the speed the foot is taken off the pedal after the brakes have been applied, rests entirely the amount of clank produced by the servo mechanism. When testing for this noise, one is apt to release the brake much quicker than what is done under actual driving conditions and a definate clank is produced. The tests therefore have been carried out under as near normal conditions as possible. In dealing with Mr. Olley's suggestion we have, after carefully testing this out under all conditions come to the conclusion, that to alter the servo mechanism as at present designed would not give us all round satisfactory results. In dealing with the ball thrust cam,levers, these are certainly an improvement on the old type non-lubricated cams., but since fitting the lubrication to the cams. they are quite as efficient and sensitive as the ball thrust cams., therefore it is not necessary to go to the expense of fitting balls with our present design of lubrication servo clank. With the present design there is a definate clank from the stops on the servo under any conditions of releasing the brakes. Mr. Olley has endeavoured to overcome this by altering the design of the servo movement, in so much that the action of the swinging arm is made to control the | ||