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).
Analysis of brake mechanism experiments and linkage designs to cure brake judder.
| Identifier | ExFiles\Box 85\1\ scan0155 | |
| Date | 27th July 1936 | |
| -14- (19) One of the big differences between N.Sch.4798 and exp. 10 (in which we reversed the brake mechanism side for side) is that in the former the line of pull of the brake ropes is above the axle in the normal and practical position, in the latter it is below the axle. We therefore made a mechanism similar to the parallelogram linkage used in a letter balance, which enabled us to apply the brake pull to the front axle at any desired height. We found that if the line of pull was asfar below the axle as it normally is above (as in exp. 10), using the N.Sch.4798 brakes no thumps occurred and it was practically impossible to get judders in the forward direction, using stiff drums, but that judders occurred very easily in reverse (as in exp. 10). FRONT OF CAR (20) We then found that combining the two nearly complete cures of experiments 18 & 19 left us free from judders going forwards, using stiff drums, judders occurring easily in reverse. This is of course not a practical way of curing judders. | ||