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).
Visit to Messrs. Firths to discuss the manufacturing processes and superiority of American-style road springs.
| Identifier | ExFiles\Box 52\2\ Scan170 | |
| Date | 12th June 1928 | |
| Hs. {Lord Ernest Hives - Chair} e. {Mr Elliott - Chief Engineer} Wor. {Arthur Wormald - General Works Manager} ROAD SPRINGS. On June 7th. I paid a visit to Messrs. Firths of Sheffield to discuss the results arrived at on the American type springs with the object of arriving at a decision as to the reason for the superiority of the American made springs of this type. As a result of the discussion it was agreed that the American spring had advantages on the top plate for two reasons :- (a) Absence of decarburisation of the steel due to the fact that the plate was forged and milled to shape. (b) A possible improved condition of the steel as a result of forging the top plate instead of producing it from a rolled bar. I was emphatic on this phase of the question owing to the fact that it was obvious that any rolled bar must necessarily:- (1) Commence with a higher temperature. (2) Finish at a higher temperature. this being the normal practice in a rolling mill, and further that the rolling action which takes place at these high temperatures does not in your opinion represent the counterpart of the forging work on a bar where the forging can be carried right down to and through the critical period of the steel. In addition I pressed Messrs. Firths to give the steel a special heat treatment in order to ensure the steel itself being in a thoroughly homogeneous condition. This treatment being given just prior to the machining of the parts or grinding of the parts to size. In order to fully cover the position outlined above, it was decided to make four pairs of springs under headings A, B, C & D. {John DeLooze - Company Secretary} given below :- (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, | ||