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 The Armstrong's Patents Co. Ltd. discussing piston clearance and movement.
| Identifier | ExFiles\Box 152\2\ scan0166 | |
| Date | 9th January 1940 | |
| COPY. To Rm{William Robotham - Chief Engineer}/79H THE ARMSTRONG'S PATENTS CO. LTD., Eastgate, Beverley, Yorks. GA.VS.{J. Vickers}5 Les.4/B. 9th January, 1940. I.A.Leslie Esq., Rolls Royce Ltd., DERBY. Dear Mr. Leslie, [Initialled] Many thanks for your letter of the 8th. January. We could produce pistons to fit closer than the .002" clearance, but there is unfortunately a difference in the expansion and contraction of the cylinder material and the piston material due to temperature and it is doubtful whether less clearance than that would be sufficient for extreme cold. Regarding movement, I quite agree with your last paragraph and perhaps I have not made myself clear. I should have explained that if you were not using the whole of the movement it might be possible to fit longer pistons with beneficial results, but I agree that it would not be wise to use longer levers to obtain this lesser movement. Yours sincerely, (Sgd) Gordon Armstrong. | ||