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).
The design principles for 'Spectre Steering', focusing on eliminating friction and improving stability.
| Identifier | ExFiles\Box 95\1\ scan0149 | |
| Date | 4th December 1934 | |
| x4694 350 Rm{William Robotham - Chief Engineer} To Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} E.11/HP.4.12.34. c. Wor.{Arthur Wormald - General Works Manager} Da.{Bernard Day - Chassis Design} re SpectreCodename for Phantom III Steering. Referring generally to the question of steering, we are working on the principle of eliminating all uncontrolled friction in the steering box, such as occurs with plain bearings in which the efficiency varies over a wide range with the conditions of lubrication, temperature, etc. Personally I think the Marles Co. in England have been working in the wrong direction in introducing plain bearing surfaces where originally ball or roller bearings were used. Our design N. Sch. 4276 is arranged on these lines, in other words, we want an efficient box possessing a consistent degree of efficiency, with a Helix angle selected to give the required degree of irreversibility. The Helix angle instructed of 6° 35 mins. comes roughly between the two mentioned by Olley, and we, therefore, think it may give the required result. Any damping friction introduced into the steering system we believe should be on the steering pivots. We are interested in the suggestion to reduce wheel fight by a stabiliser at the front end instead of the rear, as this should also be beneficial in rendering the control of the car generally more stable, particularly on cambered roads and corners. E.{Mr Elliott - Chief Engineer} | ||