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).
Technical explanation of spring compression and recoil curves under various conditions of distortion and vibration.
| Identifier | ExFiles\Box 46\1\ Scan131 | |
| Date | 3rd June 1919 guessed | |
| A.{Mr Adams} Wormald Esqr. Rolls Royce Ltd. x.x. On this blueprint you will notice that curve o.x.x.c.c.f. shows the combined action and recoil curve of a 200# spring under 2" of distortion and operating at its normal period 130 per M.{Mr Moon / Mr Moore} o.y.y.s.s.y.y.O shows the same spring under 4" of distortion both impact and recoil under its normal period 130 per M.{Mr Moon / Mr Moore} o.z.z.a.a.y.y.O shows the same spring under a forced vibration with a velocity approximately double on compression than the y.y. compression curve. O.B.B.O. gives compression and recoil line for a 300# spring distorted to 4". The normal compression and recoil lines C.A.A.O. and O.B.B.O. showing the action of the springs unaided are not actually the curve of reaction and recoil which would be found under actual service as due to inertia and friction instead of these lines being straight they would be synusoidal curves slightly separated, the exact form being dependent upon the unsprung mass and the design and friction of the spring. These exact curves being so variable depending upon the particular design, it is more satisfactory to plot the spring curve in straight lines, which for purposes of demonstration is sufficiently accurate. - You will note that with the 200# spring under small distortion the action is that of a lighter spring. Under larger distortion its compression line approximates the 300# spring for over half its length, while under forced vibrations as encountered when striking sudden obstructions, the combined compression curve gives a reaction equivalent at the start to a spring of 400# or greater flexibility per inch, the recoil curve however, remaining constant. In effect this shows that the combined action of the Oil Spring and high flexibility spring adjusts itself to the road conditions, presenting a resistance to distortion in proportion to the magnitude and velocity of the road shocks. Th. Petre & Co, 52 Conduit St Ave. W.g. City | ||