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).
Instructions for manufacturing a pair of Bentley rear composite brake drums in two different ways.
| Identifier | ExFiles\Box 84\2\ scan0362 | |
| Date | 17th October 1935 | |
| To RHC.{R. H. Coverley - Production Engineer} +206 HS{Lord Ernest Hives - Chair}/APM.4/KW.17.10.35. Bentley Rear Composite Brake Drums. Herewith is a sketch, Hs.{Lord Ernest Hives - Chair}2205, of a composite brake drum. We would like you to make a pair of drums to this drawing in two different ways. Offside Drum. To be cast in RR-53, and afterwards heat treated to give maximum strength. The liner, to be supplied by Mr. Marriot, and already instructed by him, is in N.M.C. steel. The surface of this liner to be in contact with the aluminium alloy should be copper-plated. The liner should be shrunk in with an interference fit of .004" on the diameter. Nearside Drum. To be turned from forged RR-59. The liner should not be copper-plated and should be shrunk in with an interference fit of .006" on the diameter. When the grinding is finished we would like the drum putting on a lathe, and a ball bearing pressed hard against the rubbing surface for 10 minutes in order to work harden the surface. The screws securing the liner to the aluminium should be made in N.M.C. steel. Cancelled Hs{Lord Ernest Hives - Chair}/A.F.Martindale. Att: Hs.{Lord Ernest Hives - Chair}2205. | ||