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).
Selection and design of brake systems, comparing Bendix, hydraulic, and G.M. types.
| Identifier | ExFiles\Box 111\3\ scan0178 | |
| Date | 27th October 1937 | |
| -2- RM{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}5/AP.27.10.37. not know of any instance where Bendix brakes have retained their adjustment and equalization over a reasonable period; but we know of many where they have not. Only Bendix brakes could be Bowden cable operated, as the mechanical efficiency of the wire is so low; therefore there is no alternative to Hydraulic brakes on the front. We are compelled by law to fit one mechanical brake system to the car and as the latter is still an expensive vehicle we cannot make this linkage out of bent tin and wire as the Americans do. It will have to be properly built and so we can use it for the rear foot brake as well as the hand brake. This saves us the expense of a tandem master cylinder and the two rear wheel cylinders which would be incurred if the Lockheed Bisector was used on the rear brakes. As we require the front brakes to do more work than the rear brakes, it is reasonable to use the G.M. type swing link wrapping brake on the front and only a floating fulcrum brake on the rear. Almost certainly a six inch pedal travel will be necessary (common American practice) this brings it into line with our clutch travel. If we do not like this we may have to resort to a small vacuum servo to keep down the pedal pressure when the travel is small. We have ascertained that the patent taken out in England for brake shoes held by links as in the G.M. set-up is no longer in force. RM{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} | ||