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).
Finger adjustment on the Phantom III clutch, proposing the creation of cast iron gauge plates.
| Identifier | ExFiles\Box 93\3\ scan0149 | |
| Date | 4th July 1936 | |
| To HIC. X317 Hs{Lord Ernest Hives - Chair}/Smth.4/JH. 4. 7. 36. Phantom III Clutch. It has always been R.R. practice to set the finger adjustment on clutches so that all the fingers come into contact with the trunnion thrust faces simultaneously. Logically this should be done with a driven plate of which the faces are perfectly parallel. If the faces are only, say, .001" out of parallel and the fingers are set true for one position of the driven plate, they will be .012" out of truuh when the plate is turned through 180°. Actually it is not possible on a production basis, to grind the faces of friction discs to be within .002" of parallel. We have shown that when the fingers of a Phantom III clutch have been accurately set in the shop in the standard way, they have sometimes been .016" out of adjustment with the driven plate in certain positions. This condition of course encourages jaggering. In view of this we should like you to make us 2 cast iron gauge plates 13¼" outer diameter, of which the faces are machined parallel. One should be .320" thick (corresponding to the R.R. driven plate) and the other .395" thick (corresponding to the Borg & Beck plate). We should then make it a practice to set the fingers with the gauge plate in position before finally building up the clutch. Hs{Lord Ernest Hives - Chair}/Smth. | ||