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).
Modifications to the 20HP steering system to reduce road shock.
| Identifier | WestWitteringFiles\N\October1925-December1925\ Scan1 | |
| Date | 1st October 1925 | |
| [STAMP] ORIGINAL (RY) FROM R.{Sir Henry Royce} (Fmr.) Copy to - [illegible] " HS.{Lord Ernest Hives - Chair} 20HP. STEERING. GMK.49 - G.D.FLATHER ESQ. [Handwritten] X4264 [Handwritten] X4118 Referring to HM{Capt. W. Hallam - Head Repairs}11/W29925., I did not notice that the above car was a Goshawk, but the remarks in my previous memo. are equally applicable. There are only two ways I believe of making the road shocks less felt on the steering wheel. (1) The simplest is to use the most flexible buffer springs in the longitudinal steering tube. (2) The next point is to use the steering with the highest ratio between the movement of the steering wheel and the road wheels. [Handwritten annotation] since tried & found slight improvement We believe that the best we can do with the present box as it is, is to fit the .8 pitch worm already instructed instead of the .93. This change has a compound effect, and acts better than one might expect. If this is insufficient I send herewith Mr. Hardy's drawing for modifications to the box, and the fitting of a larger worm at a slightly different radius. This gives the same relative movement as the .8 mentioned above, but is more irreversible owing to the change in the worm angle. The worm for this modification is .75 pitch, and its dia. is increased to a mean pitch dia. of from 1.035 to 1.25. The radius of the trunnion of the nuts is reduced about 6% from the centre, so that the steering wheel will make 2.3 revs from full lock to full lock, this being the slowest steering that we think will give perfect satisfaction, and will be the same as that obtained by the .8 mentioned in the first part of this para. I hope BY.{R.W. Bailey - Chief Engineer} will be able to put a few of these boxes through experimentally very quickly, as the modifications are not drastic, the box fitting in the same place as before, with the same clearance, with the exception that the steering column has to be moved one tenth of an inch nearer the centre line of the car. If you could get one of these boxes, we should be doing all we know that is possible, to please your customer. We anticipate that the complete modifications as suggested above will reduce the road shocks arriving at the hand, by nearly 50%. This we believe is as far as we can go without spoiling the ease of steering. R.{Sir Henry Royce} [Handwritten annotation] are I TOO [Illegible Stamp] | ||