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 to Messrs. Birkbys Ltd. regarding design changes to a radiator filler plug drawing.
| Identifier | ExFiles\Box 150\3\ scan0396 | |
| Date | 9th March 1938 | |
| 1280 - c. Roy{Sir Henry Royce}/Dn. Rm{William Robotham - Chief Engineer}/Std.5/MH.{M. Huckerby} // 9th. March 1938. Messrs. Birkbys Ltd., Liversedge, YORKS. For the attention of Mr.Stone. Dear Sirs, Referring to your letters of 5th. and 7th. inst. for which we thank you, we now attach herewith a print of the final detail EW.1665 for the radiator filler plug, which we discussed. You will, of course, destroy the obsolete prints which you may already have. You were quite correct in stating that there was a discrepancy in the thread particulars. The radius in question should be .0375 (at bottom of thread) but as this radius is automatically defined by the other data given for the thread, we are omitting any dimensions for same and merely indicating a radius. We have also decided to reduce the top and bottom thread diameters by .010, i.e. to figures given on new drawing. We have done this after consulting with the insert spinning manufacturers, in order to ensure a minimum diametrical clearance of .010 in the threads. The question of limits (.020 total) has also been dealt with. This new drawing, therefore, will enable you to go right ahead with tool making. As agreed we will use S0.540 grade material for this job. P.S. Will you please return Yours faithfully, Bakelite plug which you have as this is not to latest drawing. for ROLLS-ROYCE LTD. | ||