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).
Characteristic 'jaggering' effect when braking vigorously over a pothole and potential solutions involving the clutch.
| Identifier | ExFiles\Box 49\1\ Scan158 | |
| Date | 9th March 1920 | |
| X.3457 To C.J. from En. Copy to Hs.{Lord Ernest Hives - Chair} Ck.{Mr Clark} X.2628. X.3910. Re Mr. de Salamanca's Experience of Braking on chassis 3X. En10/W 9.3.20. X.345. X.1228. With reference to CJ5/E3.3.20, I think Mr. Hives would like to report on this matter as it is so closely related to experimental work. The photographs show very well indeed the characteristic effect obtained when the brakes are applied vigorously and at the same time a rear wheel passes over a pothole. This characteristic was originally investigated about 1912 when the chassis was fitted with the central foot brake drum and the foot brake in this position was abandoned for this reason. It is clear, however, that the same effect can be obtained with the brakes on the rear wheels providing the clutch is left in, and this in fact has been our experience. The lifting of the near side wheel is due to the inertia of the fly wheel. Mr. de Salamanca would find that the "jaggering" will almost, if not entirely, disappear, if at the time of applying the brake he also pushed the clutch out. In this connection Mr. Royce originally suggested, I believe at the time, that both brakes should when operated relieve 3/4 of the load on the clutch, so that when the brake is applied the clutch will slip, but at the same time the engine can be retained as a brake under ordinary conditions up to its full capacity as such. I do not know whether anything was ever done with this suggestion. contd. | ||