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).
Secret memorandum discussing potential causes and experimental solutions for steering column binding issues.
| Identifier | ExFiles\Box 67\3\ scan0101 | |
| Date | 1st April 1925 | |
| X. 8430 To Hs.{Lord Ernest Hives - Chair} from DA.{Bernard Day - Chassis Design} S E C R E T. DAL/M1.4.25. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. STEERING. X. 8430. After examining the steering column again, though we cannot see any feature that is at all obvious to account for the difference between the EAC. and 40/50 columns, we can see that there might be a difference between the way in which the cheeses are mounted on the rocker shaft, and in the design of the steering nut. We suggest that it might be a good thing to try the 40/50 nut on the EAC. column, and this could be done with the new bolted rocker shaft by making some rocker arms of exactly the same type as the 40/50 and then using precisely the 40/50 nut and cheeses. This would necessitate leaving out for the time being the control tubes, as the worm thread is smaller on the 40/50. The suggestion in this case is that the nut may be distorted by a heavy load in such a way as to bind the thread on the worm, or it is possible that the cheese may be distorted in its socket due to the way in which it is clamped on to the rocker arm, though we admit that we cannot see why this latter should be worse than the 40/50. The theory that the nut may be bound on to the worm does however seem feasible when we look at the steering nut in the plan view. Comparing it with the 40/50 it seems possible that the latter would also be bound, but it may be so weak that it cannot exert any force, whereas the somewhat stiffer construction of the EAC. nut may cause the threads to be driven into the worm with sufficient force to cause binding. We think you agree that all the experiments conducted so far indicate that the trouble lies in the steering column. We therefore suggest that it might be a good plan to go through the steering column step by step with a view to finding if possible where the inefficiency begins; for instance, when you have your device on the steering wheel for measuring the load applied by the hand it would be possible to measure the efficiency of the nut by putting an axial load on the nut alone, leaving the pendulum lever free. It would then be possible to put a balanced load on the rocker shaft, that is, a double armed lever or wheel, with a load at either end so as to impose no bearing load on the rocker shaft, and finally the pendulum lever might be loaded in the way you have already done. An experiment which no doubt you have also thought of is mounting the Hispano steering on an EAC. chassis. As far as we remember of it it looks as though this would be possible, and probably easier than mounting a 40/50 steering on that chassis. contd :- | ||