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).
Further experiments on road springs, focusing on side load deflection and its impact on spring life.
| Identifier | ExFiles\Box 72\3\ scan0123 | |
| Date | 12th September 1924 | |
| X.9410 To HS.{Lord Ernest Hives - Chair} from DA.{Bernard Day - Chassis Design} S E C R E T. DA{Bernard Day - Chassis Design}2/M12.9.24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. RE. ROAD SPRINGS. X.9410 You sent us some particulars a little while ago of tests of loading the spring from the side, shewing that the stiffness of the top plate was about twice. As we are very desirous of understanding the phenomenon of the springs we suggest that some more experiments should be made. Could you test this deflection resulting from a side load when the spring is bent to the maximum bump? This should be more than when the spring is flat. Another point would be to determine whether there is any sideways deflection on an ordinary road bump when the spring is flat, and if so, how much. It appears to us that this could be done by a pointer moving with friction in a guide which would register the maximum sideways deflection when the spring is flat. In order to determine the influence which the side load has on breaking the springs we suggest that at least two top plates should be tied together so as to be rigid sideways. This could be done by making sure that the clips fit sideways. It is true, that we expect this would rack the frame more, but it would be interesting to know whether it increased the life of the spring on the bumping rig. Another thing we suggest is that the bumps should be put in line so that both springs are deflected together and as far as possible there is no side translation. If there is anything in the side load, the spring should last very much longer under these conditions than when there are alternative bumps. We understand that you have some front springs which have top plates thicker than standard? If so, the improved life on the bumping rig, if any, would be of interest. DA.{Bernard Day - Chassis Design} | ||