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).
Recommended brake leverages, cam angles, and proposals for a 10,000-mile test.
| Identifier | ExFiles\Box 12\5\ 05-page155 | |
| Date | 2nd November 1929 | |
| X 7360 To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. Sg.{Arthur F. Sidgreaves - MD} c. Wor.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} c. Ds. EV.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/Rn{Mr Robinson}3/ADL2.11.29. BRAKE LEVERAGES. ----------------- The brake leverage that we recommend is 1.72 S 35º Cams The direct braking without the servo is sufficient for shunting. The altered cam angle gives slightly more front braking with the servo in action. We mentioned the effect of wear on the pedal travel in our Hs{Lord Ernest Hives - Chair}/Rn{Mr Robinson}3/L339.5.29. There is no doubt that our being forced to reduce the proportion of front braking to avoid squeaks has increased the feeling of sponginess on the pedal and also increased the maximum temp. that the rear drums are likely to attain on exceptionally steep gradients. We should like to run the next 10,000 miles test with the altered leverage to the rear brakes and sufficient lining on the shoes to ensure that after five notches wear the toggles can be adjusted to give another five notches wear before the brakes are worn out. | ||