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 discussing the measurement, materials, and tolerances for driven plates.
| Identifier | ExFiles\Box 129\3\ scan0334 | |
| Date | 9th July 1936 | |
| -2- Hs{Lord Ernest Hives - Chair}/Smth.14/KW.9.7.36. Driven Plate Thickness. We found yesterday that although the clamps we use to compress the driven plates during measurement are apparently similar to yours, we usually find a greater variation in thickness than you do. In view of the difficulty of clamping the plates locally in a way that would truly represent working conditions, and at the same time allow a reasonably rapid inspection, we both agreed to inspect the plates by pressing them between two rings of 1" less diameter than the outer diameter of the fabrics and then finding the variation in thickness of the projecting portion of the plate. If plates passed as satisfactory in this way give trouble in motor cars, we shall have to reconsider this point at a later date. We understand that you have made arrangements to use bright steel sheet for your centre plates in the future instead of the present material. This change will come into effect in two or three weeks' time. Until that time you have asked us to increase the tolerance from .005" to .007", and we have agreed to this. We hope that as a result of yesterday's discussions we shall both be able to work on a more satisfactory footing. May we take this opportunity to ask you to urge the two special 10" plates lined with "No.6" material. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||