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 from Thos. Firth & John Brown, Ltd. regarding the design of 20 HP Flexible Road Springs.
| Identifier | ExFiles\Box 52\2\ Scan283 | |
| Date | 28th May 1931 | |
| 84429. THOS. FIRTH & JOHN BROWN, LIMITED, SUCCESSORS TO THE COMPANY. WORKS. London Office: 8 THE SANCTUARY, WESTMINSTER, S.W.1. Telegraphic Address: "MESMERIC, PARL, LONDON" Telephone Number: 8310 VICTORIA Please note our Telephone Numbers now are:- ATLAS & NORFOLK WORKS - 20081 (11 Lines). TINSLEY WORKS - 41193 (4 Lines). FIRTH & SONS, LIMITED N.95. 27th April, 1931. SHEFFIELD YOUR REFERENCE OUR REFERENCE: HWP/AR/837. DEPARTMENT: SPRING. DEPT. PHONE EXTN. T.33. May 28th. 1931. Messrs. Rolls-Royce, Ltd., Nightingale Road, DERBY. 20 HP. Flexible Road Springs. For the attention of Mr. W.A. Robotham. Dear Sirs, With further reference to our letter of May 27th, we have discussed the matter with Mr. Stanfield, who we understand is writing to you tomorrow separately on the general question. However, in order that both you and ourselves may more fully appreciate the point at issue, we are in accordance with Mr. Stanfield's suggestion submitting to you a further design of the 20 HP. Front Springs referred to in your letter of May 21st. This design, you will note incorporates your own suggestion of a 0.3" thick mainplate, and 4" deflection under load. At the same time, whilst the stress on the mainplate in the normal loaded position is relatively small, about five tons, the range of stress in this plate is quite high i.e. a range of 43 Tons between normal loaded and normal unloaded position. The actual range in practice would be still higher, since this calculation does not take into account the additional stress when the spring deflects to the maximum bump position. We shall be interested to learn your views on this further design which we will send to you tomorrow, and the other three alternative designs referred to in our letter of yesterday For your information the attached sheet contains some further particulars which you should know of the three alternative springs suggested in our letter of yesterday. Yours faithfully, THOS. FIRTH & JOHN BROWN, LIMITED, [Signature] for Director. | ||