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 detailing specifications and conversion options for Phantom steering systems.
| Identifier | WestWitteringFiles\S\2April1928-June1928\ Scan064 | |
| Date | 28th April 1928 | |
| HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} O.{Mr Oldham} to BJ. BY.{R.W. Bailey - Chief Engineer} PN.{Mr Northey} SG.{Arthur F. Sidgreaves - MD} PHANTOM STEERING. For the present production the best we can do is - .720 Worm and box. Rocking lever 1.75". Pendulum lever 9½". Steering lever on axle 9¾" giving a leverage of 15/1, known as F.2. conversion. It is assumed that this 9¾" pendulum lever allows the longitudinal tube to be balanced, and the ball under the frame. If not, the lever must be increased to 10". Regarding the cars with the old type axle in which the side steering lever is 8", the only thing we know of to fit with this axle would be the original box given in your list as 'V' series, with a new worm and nut, and a pitch .8125, .825, .850, or .875. The one we should like best would be .825, giving a leverage of about 15/1. For the "SS{S. Smith}" I want you to try first the big worm .900 pitch, 2" lever in the box, 7½" pendulum lever. This will be quite good for a trial, but in case this does not give entire satisfaction the pendulum lever can be increased to 8", or the pitch of the worm to .960. In all cases the turns of the wheel for our standard full lock to full lock should be within 5% of 2¾. R.{Sir Henry Royce} | ||