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).
Fault in the 40/50 HP servo brake mechanism involving the front equaliser shaft and swinging link, leading to brake snatching.
| Identifier | ExFiles\Box 66\5\ scan0100 | |
| Date | 11th February 1927 | |
| To BY. {R.W. Bailey - Chief Engineer} } FROM HS {Lord Ernest Hives - Chair} /RM. {William Robotham - Chief Engineer} To DA. {Bernard Day - Chassis Design} (Handwritten) 8470 Hs {Lord Ernest Hives - Chair} /Rm {William Robotham - Chief Engineer} 5/LG11.2.27. 40/50 HP. SERVO. (Handwritten) X8370 (crossed out) (Handwritten) X8420 CWH. has pointed out a difficulty on the 40-50 HP. servo with the new front equaliser shaft for the latest front axle. We require friction at q. sufficient to give 25 lbs. load at the end of the swinging link. Assume that in sketch 'A' the front and rear brake levers are up against their stops and the ropes are just tight. The brakes are applied in sketch 'B', and owing to the difference in leverage, S. moves much further than R. {Sir Henry Royce} and the xxxxx swinging link operates to counteract thumps. When the brakes are released, however, the swinging link remains stationary and the rear brake pull-off springs rotate the T. lever until the rear levers come up against their stops. The result is that the other end of the T. lever r. {Sir Henry Royce} moves further forward than its original position and slacks off the front brake ropes. The next time the brakes are applied the swinging link remains stationary and so the friction does not function. The front brakes are snatched on, and thumps occur. contd :- | ||