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).
Letter to Toledo Woodhead Springs Ltd. outlining technical issues and questions regarding their spring components.
| Identifier | ExFiles\Box 154\2\ scan0162 | |
| Date | 12th November 1938 | |
| Toledo Woodhead Springs Ltd. -2- 12th. November 1938. (3) We have had trouble due to the interleaving settling down between the clamping bolts, with the result that the latter come loose and allow the leaves and interleaving to move all over the place, with considerable resulting damage. We are trying small brass plugs pressed into holes in the interleaves and the same thickness as them, so that the damping load is taken on these plugs and not on the interleaving. What do the Americans do about this settling ? Or don't they get it ? (4) As a consequence of the clamping bolts coming loose, we have sheared the 5/16" dia. bolt holding the spring together, and acting as a location. Why do you make the holes in the leaves diamond shaped ? They seem to cut through the bolt more than a round hole would. Surely a round hole is cheaper ? (5) We want a lot more interleaving 2" wide to replace that which failed on the French test. Any interleaving is better than none, but we would prefer the toughened end type. Ought the interleaves to be shorter than the spring leaves ? The replacements you set us were shorter, but previously they have always been longer. (6) As your springs are not polished we suppose that interleaving is essential, and that an oil feed along the spring is an impossibility. We have been considering a lubricating scheme consisting of a tubular wick along the groove of the springs, but as the springs are not polished we doubt if the oil would stay long enough inside the leaves. It therefore appears necessary to get the interleaving to work, or else to stick to Firth's springs. The results so far are disappointing. (7) We enclose a drawing which shows a threaded hole in the eyes for a screw to retain the bushes, which we would like on future springs. | ||