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 discussing issues with front axle controls and the front bumper bar design.
| Identifier | ExFiles\Box 83\4\ scan0051 | |
| Date | 7th November 1935 guessed | |
| - sheet 2 - see if the oil retaining bush is present or not. Front Axle Controls. With regard to the bearings of the axle controls, I remember some previous trouble due to a failure of the lubrication which received the design attention, but we have no official experimental complaint about the capacity of these bearings. We will take this point up with HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Front Bumper Bar. With regard to GWH{George W. Hancock - Head Chateauroux}'s remarks about this item, the present design is not the nut inside the dumb iron. This nut was a protem design to fit bumpers on to existing Bentley cars and production cars with the existing dumb iron stampings at the time when the bumper bar was introduced. Strictly speaking GWH.{George W. Hancock - Head Chateauroux} has no business to be testing this arrangement in conjunction with the big bore engine as it was only an adaption to a certain number of Bentleys and represents the design which is now obsolescent. In the present design the stud is screwed direct into a boss provided in the dumb iron and locked with a taper pin instead of the shaped piece of steel which formed a nut inside the dumb iron. The pin called for by the design is larger than the one actually instructed but there is no pin which would withstand the treatment without cutting the stud in half and failing in another way. The fault is that the stud has not been properly screwed home into its housing, or nut, as the case may be, before the pinning operation. In any case the design shows a generous amount of thread for covering discrepancies which might occur in the thickness of the bumper bar, but unfortunately the detail drawing we found did not make the same allowance but has now been altered. We are concerned that this stud should not have been properly screwed home, and we have, therefore, modified the stud to have a collar against which it shall be screwed. Even this will not be proof against a mechanic who cannot tell whether he is tightening the job or twisting the stud, but it will oppose more than an equal resistance to the nut coming up against the end of the thread if this contingency is at any time likely to recur. | ||