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).
Development and issues with a four-wheel brake system.
| Identifier | ExFiles\Box 73\2\ scan0322 | |
| Date | 1st April 1924 | |
| Mr.(Chairman-Council) Mr.Hives Mr.Bailey Mr.Hall C. Hs.{Lord Ernest Hives - Chair} Reakes Foremans FOUR WHEEL BRAKES. He. has reported various matters that are very important with regard to the designs now going through. In his report, Hs{Lord Ernest Hives - Chair}/ACL/143.4.24, he gives figures for the ratio of input to output of the flat plate servo, put through for the agreed scheme, and which, in accordance with your instructions, is being retained for the M.DES.60. Apparently the explanation of the falling off in efficiency with load is due to dishing of the plates, which reduces the effective radius of the clutch. We have never been able to obtain what we expect or desire from this type of servo. As an experiment, we are reducing the face of the ferodo by half, cutting away the inside. We are also making some plates of much heavier section to reduce the bending for comparative tests. He. reports that the 35° angle thread is inclined to stick in. This point is being investigated, but it may necessitate some alteration in the lengths of the levers before we obtain the right ratio of loads. We are finding it very difficult to get the steering lock as good as on the old 40/50's. The cars running in France and the bump test seem to show that the front spring brackets are up to their work, but we now have a report that front brake jiggers have been encountered. Another point on which we do not seem to have made any progress is with regard to better protection for the joints of the operating rods on the front wheel brakes. I am sorry to hear today that you will not be back on the 10th. inst., as I was hoping we should then be able to get all these points cleared up quickly. Da.{Bernard Day - Chassis Design} and R.{Sir Henry Royce} are coming to Derby tomorrow, so as to see for themselves the experiments we have in hand. I think it is the quickest way of dealing with these points. At the moment it looks as though it will be a long time before we give the customer the first car with four wheel brakes. Rg.{Mr Rowledge} | ||