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).
Comparison of leaf spring lubrication and manufacturing methods, with proposals for a new spring design.
| Identifier | ExFiles\Box 154a\2\ scan0361 | |
| Date | 1st July 1941 | |
| -2- 3. The system used on A.E.C. buses in which the ends of the fifth leaf are tapped 1/8" gas for flexible pipe connectors (See Woodhead drawing, D.O.17228 which is attached). The oil is then led where required by holes drilled in the plates and rolled grooves. The grooves are blocked where necessary by blobs of welding. This scheme does not appear to be as good as our own, particularly as Woodheads have, in the past, pressed our grooves in. The only strong objection raised to our system of lubrication is the drilling and bushing of the main leaf particularly the front end. The substitution of solid eyes for rolled eyes would render the bushing unnecessary and might reduce costs. We propose to ask Woodhead's for their views on the following spring : Main Leaf.- Solid eyes. Oil holes drilled as at present, except bushes omitted. (These bushes are not to be confused with the main spring pin bushes). Other Leaves. Oil grooves pressed in as Woodhead's have done before. Clips. No reduction in number. General. Leaves to be left black. Woodhead's Method of Manufacture. The method of manufacture in use at Jonas Woodhead's is as follows :- 1. Leaves are out to length. 2. Eyes are formed in the main leaf. Ends of other leaves are drawn, or speared for preference. 3. Leaves are heated in furnaces. The majority of these are fired by coke. The newer ones are oil fired. Woodhead's said the former caused more decarburization. 4. The leaves are bent on formers. On the older jigs, the leaves are still on the formers when quenched. On the new jigs the leaves fall from the formers to the quenching oil. This is less messy. Neither method produces a leaf free from curvature errors. 5. The leaves are tempered. -Continued- | ||