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).
Test report on rear road springs detailing issues with cracked leaves after a 36-hour bump rig test.
| Identifier | ExFiles\Box 80\2\ scan0280 | |
| Date | 1st June 1920 | |
| X.3981 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to Bn.{W.O. Bentley / Mr Barrington} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} X.3981. X.2628. RE ROAD SPRINGS. Hs{Lord Ernest Hives - Chair}2/LG3.6.20. We have now completed 36 hours running on the bump rig with a pair of rear springs which have the following features:- 1. No nibs and slots. 2. Surfaces between the leaves ground all over. 3. Curvature from plate to plate constant. We found at the end of this run that on the O.S. spring the top, 3rd, 4th, and 5th, leaves were cracked, in some cases half-way across the plate, all the same point of the spring, i.e. found under the front spring shackle. On the N.S. spring we found that the 3rd, 4th, and leaves were cracked in a similar position i.e. under the front spring shackle. As was anticipated the end of the leaves still dig into the next plate. The bedding of the plates is only on spots and one can see where they have seized. The test has shown that the weakest part of the leaves, when we have no nibs and slots, occurs at the spring shackle. We have tried on an Experimental Car a set of standard springs but the sheared end portion of the leaves made tapering in thickness. We have run these springs for about 1,000 miles on a car. We found that the leaves will still squeak Contd. | ||