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).
Investigation into the failures of pendulum steering levers and summarizing results from bumping tests.
| Identifier | ExFiles\Box 38\1\ Scan053 | |
| Date | 30th September 1919 | |
| R.R. 235a (500 T) (S.D. 408. 28-4-17.) Bm. 2/156/13. X.3465 To R.{Sir Henry Royce} from Bn.{W.O. Bentley / Mr Barrington} c. to Oy. Bnl/W30.9.19. Copy to CJ. c. to EP.{G. Eric Platford - Chief Quality Engineer} " " Wor.{Arthur Wormald - General Works Manager} for By.{R.W. Bailey - Chief Engineer} c. to Hm.{Capt. W. Hallam - Head Repairs} " " Da.{Bernard Day - Chassis Design} c. to CK.{Mr Clark} " " Hs.{Lord Ernest Hives - Chair} c. to HI. RE PENDULUM STEERING LEVERS. X .3465. X .205. We find it difficult to obtain accurate and detailed information regarding the failures of pendulum levers which have occurred. There were three cases reported from Paris, but only in one case was a sample of the fracture sent back. This was referred to in Bnl/W22.8.19. Capt. Hallam has experiences of no failures except that he understands that there were one or two failures on cars repaired at Derby immediately prior to the war, and that beyond this there was one case in France in 1915 in which, after examination he concluded that it had been in an accident and straightened. Mr. Platford informs us that breakages are occurring in America pretty regularly, and all in the same place, that is, about 1" from the boss, but that only a few broken ones are available, as they are disposed of quickly to avoid inspection by drivers etc. He states that the lever on 50 PB. broke after about 40,000 miles, and that these fractures only appear to occur after long use. The present standard lever was strengthened up some time prior to the War, and there appears to be no doubt that the strengthened lever fails. We have no samples of broken levers from America. We have been through the whole of our records of bumping tests and tests ( on the rig which oscillates pendulum lever, and crank). The present standard lever C.585 tested on the bumpting rig with 3" bumps at 105 revs. per minute, had an average life of 4 hrs. 20 mins. taken for 13, the minimum time for breaking being in one case 45 mins. and the maximum 9 hrs. 26 mins. This result, obtained toward the end of 1913, apparently caused the design for an oval section lever to be prepared. The first design of this lever F.3724, was tested on the oscillating rig, and one broke in 10 minutes and another in 36 minutes both tearing through the boss. Contd. | ||