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 British Thermostat Co. proposing a design modification to prevent drill breakages during the manufacture of the Bentley Thermostat.
| Identifier | ExFiles\Box 156\2\ scan0142 | |
| Date | 10th October 1938 | |
| Telephone: SUNBURY-ON-THAMES 456 (6 LINES) Telegrams & Cables: THERMOSTAT, SUNBURY-ON-THAMES. Code: BENTLEY'S THE BRITISH THERMOSTAT CO., LTD. Makers of Scientific Instruments. TEDDINGTON WORKS. Windmill Road, Sunbury-on-Thames, Middlesex. DIRECTORS: COL. N. HUDSON. J.{Mr Johnson W.M.} E.{Mr Elliott - Chief Engineer} SHERLOCK W. F.{Mr Friese} F.{Mr Friese} MARTIN-HURST } MANAGING. L. S. SWINNERTON DYER. F.{Mr Friese} G.{Mr Griffiths - Chief Accountant / Mr Gnapp} POPLETT. ON A.I.D. AIR MINISTRY APPROVED LIST. WMH/GN: October 10th, 1938. Messrs. Rolls-Royce Ltd. DERBY. Dear Sirs, For the attention of Mr. Steadman. There is one further point in connection with the manufacture of the Bentley Thermostat which we would like to raise. When we drill the spindle for the insertion of the locking pin the drill point sometimes breaks through the brass portion in such a position that it is required to drill a hole through the sloping portion of the thread on the stainless steel spindle. As a result, whatever care is taken, and despite the use of a well-made drilling jig, there is a tendency for the drill to break, and in fact, as many as three drills have been broken on one assembly. This could very easily be overcome by providing a flat on the thread, as shown on Drawing No. BG. 4509 enclosed, this flat being in line with another small flat on the upper thread to show its position when it is screwed into the brass body. Have you any objection to our making this slight modification for ease of manufacture? If you are agreeable you may care to modify your own detail. We shall be obliged if you will let us | ||