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).
Technical review of issues and proposed modifications for a Clamping Bolt, Top Cover, and Cartridge.
| Identifier | ExFiles\Box 99\3\ scan0058 | |
| Date | 19th January 1938 | |
| -5- HPS{Horace Percy Smith - Experimental Factory Mgr}/WB.{Mr Brazier/Mr Bell}1/EP.{G. Eric Platford - Chief Quality Engineer}19.1.38. Clamping Bolt FB.3417 and Nut FB.3418. The clamping bolt was considered satisfactory but the hexagon of the nut was definitely too large, the corners fouling the rocking lever. Even had the webs of the rocking lever been chamfered to clear the nut, it would not have been possible to fit a spanner on to the nut. To overcome the difficulty, the hexagon was reduced to .600" across the flats, this makes the split pin slots rather large in proportion to the sides of the hexagon, consequently reducing the split pin to .062" should be considered. Top Cover FB.3407. This will eventually be a die-casting, but whilst sand castings are used it will be preferable to spot face the securing screw holes .515" diameter to remove burrs in one operation. The off-set, set-screw boss fouls the box spanner required to tighten up the valve cartridge, and although a standard jaw spanner could be used, a box spanner will be found to be much more convenient for use when the damper is fitted to the chassis. It should be possible to re-space the holes or alternatively reduce the number of set screws to five, and thus clear the valve cartridge. It would also assist if the plain section now above the hexagon on the cartridge, was machined below the hexagon, to give a better spanner grip. Cartridge FB.3452. The ability to remove the valve unit complete without loss of oil should prove a boon both from a production and an experimental view point, but necessarily requires considerable care in the manufacture of the details involved, otherwise an excessive uncontrollable leakage factor will be introduced. The manufacture of the cartridge involves boring four internal diameters and three threads, and whilst only one internal diameter has a fine limit, concentricity is essential. Externally there are six different diameters and one thread, and in this case three of the diameters are given as fine limit dimensions. As remarked in the review of the main casing there is no reason why the .9995 -5 diameter should not be modified to .995 -5 diameter, providing the top joint face is sound. continued | ||