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).
Secret memo discussing a clutch fault caused by gravity and a proposed design change involving a spring.
| Identifier | Morton\M20.1\ img032 | |
| Date | 1st May 1924 | |
| R.R. 235A (100 T) (S.H. 159. 11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2500 TO HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} Copy to CJ. RG.{Mr Rowledge} DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} (crossed out) S E C R E T. R2/M12. 5. 24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. CLUTCH. Y9301 (crossed out) Y9480 We have decided that the reason for this clutch not stopping is due to the gravity causing the clutch plate to hug the rear friction surface, firstly owing to the incline of the transmission, and secondly the extra weight of the coupling shaft between the engine and gearbox. This has been proved to be the case because the fault is so much worse on a hill where it is specially desirable that the clutch should stop quickly. To my instructions a device was sent to take advantage of this gravity, but the first design was not quite the arrangement I had imagined. We therefore sent you another design for this gravity clutch brake last week. We are now sending you a fitting to increase the gravity effect so that the clutch should not continue to revolve even if the nose of the car is pointing downwards, in which position it may be necessary to get in the reverse to propel the car backwards. Such a test should be part of the investigations, but we think with thisspring set to about quarter the weight of the propeller shaft and clutch disc, no further trouble should be experienced. R.{Sir Henry Royce} | ||