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).
Scheme for strengthened pendulum levers due to breakages and cracks on a number of cars.
| Identifier | ExFiles\Box 153\4\ scan0167 | |
| Date | 21th October 1943 | |
| To Wym.{G. Harold Whyman - Experimental Manager} c. to Rm.{William Robotham - Chief Engineer} Ev.{Ivan Evernden - coachwork} FJH.{Fred J. Hardy - Chief Dev. Engineer} Ev{Ivan Evernden - coachwork}/JD.{J. Draper - Frames} Ev{Ivan Evernden - coachwork}/HH. Wym{G. Harold Whyman - Experimental Manager}/C.Lee. Wym{G. Harold Whyman - Experimental Manager}/HN{F. C. Honeyman - Retail orders}/ED.{J. L. Edwards} 1300 Ev{Ivan Evernden - coachwork}/DB.{Donald Bastow - Suspensions}1/JH.21.10.43. B.V., B.50., Silver Wraith, etc. Steering Column & Box. PL.2687 Strengthened Pendulum Levers. Reason for scheme. Broken or cracked pendulum levers on a number of cars. Other schemes used in conjunction. None. Description. Basically three lengths of levers were required to cover the range 5.325", 4.825" and 5.875". It was found however, that no dies of the 4.825" length existed which were suitable for opening up - see Ev.{Ivan Evernden - coachwork}7/JH.1/.43.- and accordingly it was decided to cover the range with 5.325" and 5.875" lengths only, the effect being a higher geared (and therefore heavier) steering on the B.50. cars, which would use the 5.325" lever length with a different spline setting to accommodate the different column angle. It will be seen, therefore, that three new details are required but the levers concerned can be produced from two different types of forgings. The guiding rule covering the design was to obtain at least 100% increase in section modulus at critical points and this has been achieved. At the same time the opportunity has been taken of increasing the rocker shaft boss strength where the lever runs into it, a modification already incorporated on some of the previous pendulum lever details though only in conjunction with the longer rocker shaft which is not being used here for obvious reasons. The material on previous drawings has been nickel steel (S/N) and the permitted Brinell range 286-311. The suggested material for these levers is EN.16, heat treatment V, for which the Brinell range is 285 - 352, and for which the Izod value is the same as for nickel steel. We suggest that the levers should be tape - polished as now, and then shot - blasted as an additional safety measure. The relevant particulars for the three levers are :- Cont'd.{John DeLooze - Company Secretary} | ||