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).
Spring rust-proofing, quenching plates, and stiffness measurement.
| Identifier | ExFiles\Box 43\2\ Scan205 | |
| Date | 6th July 1927 guessed | |
| - 10 - If the gaiters receive attention with a syringe every 2000M. or so, the springs stay clean, but when neglected, as they often are, springs appear to rust worse with gaiters than without. We therefore anticipate a possible rust-proofing of the spring by cadmium plating each leaf ("UDYLITE" process) and then lubricating the springs from the Bijur system. In such a case, we should recommend omitting the gaiters, and using an outside valance over the rear spring on all cars. Quenching plates. The plates are quenched on circular forms of radii, 165" for main plates, 70" for .250 plate, 56" for .218 plate, and 45" for .187 plate. The tangential flats at the ends are ground on after hardening, also the approach curve at the end which prevents the plate digging into its neighbour with continued use. As a matter of convenience in manufacture, small differences in plate lengths such as would occur in the slight difference between spring A.3546, 1100 lbs, and spring A.9309, 1150 lbs, are avoided and identical plate lengths are used on both springs, with reasonably good results. It is convenient also to retain the same number of leaves in springs of the same type, but this is not possible entirely and one is driven to increase the number of plates, with increase in load, to keep the stresses down. Measuring Springs. The stiffness figure is stamped on the short leaf of each spring as well as the flat load. Stiffness is measured thus:- | ||