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).
Manufacturing specifications for four pairs of American type springs, designated (a), (b), (c), and (d).
| Identifier | ExFiles\Box 43\2\ Scan253 | |
| Date | 25th August 1928 | |
| Hs.{Lord Ernest Hives - Chair} X3900 BY7/G.25.8.28. FOUR PAIRS OF AMERICAN TYPE SPRINGS. The Order Office are handing to you today . the four pairs of springs referred to above. They are stamped in pairs, (a), (b), (c) and (d). The interpretation of the letters is as follows:- (a) Top leaf. Eyes to be drop stamped from a billet of thickness slightly greater than the outside diameter of the eyes. The centre portion to be forged, leaving 1/8" on each surface and edge for machining. This surface to be milled off. The remaining leaves to be precisely as at present supplied. (b) Top leaf manufactured as per (A), the remaining leaves to be rolled 30/1000ths thicker than the finished size, these to be ground, removing 15/1000ths from each face. The edge also to be ground. (c) Top leaf to be from rolled bar of such a thickness as to allow a minimum of 1/8" machining on each face and edge. The eyes to be jumped up. The remaining leaves to be made as per (A). (d) Top leaf to be as per (C), and the remaining leaves as per (B). BY.{R.W. Bailey - Chief Engineer} | ||