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).
Particulars of high deflection front springs for the 20/25 HP model, including three alternative suggestions.
| Identifier | ExFiles\Box 52\2\ Scan282 | |
| Date | 27th May 1931 | |
| High Deflection 20/25 HP. Dated May 27th. 1931. Front Springs. Particulars of Springs. Description. Plate Nos. Thick. Inches. Finished. Lengths Inches. Ecc. Dist. Inches. Remarks. High Deflection 20/25 HP. Front Springs as Desp'd to R.R. Order 11581 of 24/1/31. These springs have been tested at Derby on bump. 1 .22 38+2 eyes. 1.0 2 .20 36 .95 Clip Plates X. 3.X. .20 31.7/8 .84 4. .19 27.3/4 .74 M.P. Range of stress=31.6 Tons per sq. inch. 5 .18 23.3/4 .64 6 .18 19.7/8 .54 7.X. .18 16 .44 8 .17 12.1/4 .35 9 .17 8.1/2 .25 Totals 1.70 First Suggestion (A) Five plate spring. 1 .28 2.X. .26 Clip Plates x. 3 .24 4.X. .23 M.P. Range of stress=30.2 Tons per sq. inch. 5 .22 Totals 1.23 Second Suggestion (B) Six Plate Spring. 1 .27 2.X. .25 Clip Plates X. 3 .23 4.X. .21 M.P. Range of stress=30.4 Tons per sq. inch. 5 .21 6 .21 Totals 1.38 Third Suggestion. (C) Seven Plate Spring. 1 .26 2.X. .24 Clip Plates X. 3. .22 4 .21 M.P. Range of Stress=30.4 Tons per sq. inch. 5.X. .20 6 .19 7 .19 Totals 1.51 NOTE:- Only mainplates of above springs are ground flat. All other plates are concave buffed. | ||