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).
Cost request for the production of an Aluminium-Cast-Iron Composite Drum and Bentley brake shoes.
| Identifier | ExFiles\Box 85\1\ scan0019 | |
| Date | 6th February 1936 | |
| X-206 To G/Rb.{R. Bowen} Hs{Lord Ernest Hives - Chair}/AFM.{Anthony F. Martindale}11/KW.6.2.36. Aluminium-Cast-Iron Composite Drum. We would like to know the cost of production in Bentley quantities of brake drum Ex.20720, the liner being shrunk in and secured by means of 4 keys and 4 bolts as shown in Rm.{William Robotham - Chief Engineer}55. The aluminium is a sand-casting in R.R.53. The ribs are skimmed up to a smooth finish. The interior cylindrical surface is machined to close limits. The millenite ring is inserted with an interference fit of .025", necessitating raising the aluminium to a temperature of 200°C. It is machined on the outside to close limits, being finished on a grinder to give a smooth surface. Four slots are cut on the inside edge before insertion, and the rubbing surface is finished as usual when the drum is complete. The 4 fixing keys are rivetted in position after insertion of the liner, and then the holes for the 4 bolts are drilled and tapped. These bolts in the case of a millenite ring are threaded along their whole length. We would like to know the cost of the above without hub, and the cost of a Bentley rear brake drum with end plate fixings but without hub. We would also like to know the cost of Bentley rear brake shoes, and how much of this cost is due to the use of tipping shoes. Hs{Lord Ernest Hives - Chair}/A.F.Martindale. | ||