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).
Difficulties with clutch clearance and a comparison of the EAC 'V' Series, 20 HP, and Hispano clutches.
Identifier | ExFiles\Box 68\1\ scan0333 | |
Date | 25th September 1924 | |
R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. 18280 REF Hs{Lord Ernest Hives - Chair}3/LGS.2.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. SJ. c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} RG.{Mr Rowledge} c. to Wor.{Arthur Wormald - General Works Manager} S E C R E T. EAC. 'V' SERIES CLUTCH. With the increased leverage to give the lighter clutch pedal pressure, we are in difficulty to get sufficient clearance. We find that the minimum clearance to ensure that the clutch will always be free, and stop, is .060". This allows for the set of supplementary springs to be .025". The trouble is worse on cars fitted with 'B' type steering because on there the clutch movement is only 3". We are finding that owing to deflections in the various parts of the operating mechanism of the clutch, we lose nearly .900" in the pedal movement. We attach a full report showing where this deflection occurs. We are also sending comparisons between the EAC, 20 HP. and Hispano clutches. The 20 HP. clutch works wonderfully well. We have not heard of a single complaint from the 1,200 mx{John H Maddocks - Chief Proving Officer} cars which have been made. The Hispano is interesting because it has light clutch pedal pressures, but it will be seen that these are obtained by very large travel on the clutch pedal. The Hispano has no flexibility for smooth pick-up. We find we cannot get consistently smooth clutches without this flexibility. Hs.{Lord Ernest Hives - Chair} | ||