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 memorandum regarding the design and testing of the 'Myth' front suspension lower triangle levers.
| Identifier | ExFiles\Box 110\3\ scan0029 | |
| Date | 30th December 1940 | |
| To Rm.{William Robotham - Chief Engineer} from Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} Copy to Rm{William Robotham - Chief Engineer}/HH. Ev.{Ivan Evernden - coachwork} 746 1030 Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions}8/ET.30.12.40. MYTH FRONT SUSPENSION. PL.426 attached shows the lower triangle levers of the Myth front suspension. The levers themselves are forgings and, at Rm.{William Robotham - Chief Engineer}'s request, they have been made as light as possible, being stressed generally up to 45,000 lbs/in2, under full bump conditions, i.e. maximum spring load and assumed rubber bump buffer load. The levers themselves are not handed, but the spring support pressing bolted to them is different on both sides of the car. The groove in this pressing for spring location is intended to take the last half coil and the tengential end on the spring, and is inclined over in relation to the pressing, so that this last half coil can have the same pitch as the rest of the spring coils when free, and so that the spring will be straight in the full bump position. It may be found that the high stress in the levers will lead to undue flexibility and modification of the spring rate curve, but this can be ascertained by test. The object of the long bolt near the inner end of the levers is to put initial set up end load on the Harris bushes used there. These Harris bushes are shown on the front pan scheme which will be issued later. Simmonds lock nuts have been shown on the various bolts, with the idea of trying them in service conditions. Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions} Original to Rm{William Robotham - Chief Engineer}/HH. Prints to Rm{William Robotham - Chief Engineer}/HH. & Ev{Ivan Evernden - coachwork}, + Ashby. | ||