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).
Front bumper failures on a Bentley chassis, proposing a material change and design modifications to prevent stud breakages.
| Identifier | ExFiles\Box 118\2\ scan0270 | |
| Date | 5th June 1936 | |
| F.J. Hardy BY.4/G.5.6.36. What stress is likely to be thrown on stud if leaves do not slide? Rm{William Robotham - Chief Engineer} Sr. c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Hd.{Mr Hayward/Mr Huddy} X 1023 BENTLEY CHASSIS B.19-DK. MR. FERENCZI RE: FRONT WILMOT BREEDEN BUMPERS. VA.5/ET.3.6.36. Levallois. We wish to confirm our wire of even date reading as follows :- " CHASSIS B.19-DK. BUMPER. THINK TROUBLE DUE TO COLLAPSE OF LEAD. SUGGEST REPLACING LEAD BY PHOSPHOR BRONZE. " from which you will note that we are not in agreement with replacing the lead weights in the bumper by wood blocks, as this would only result in a further complaint of wing movement. Our object in suggesting replacing the lead weight by a phosphor bronze weight is that Mr. Hancock in France has found that the lead weight collapses on its vertical dimension and the resultant slack we think is probably responsible for considerable increase of shock load on the stud securing it. We are perturbed in reading your memo VA.5/ET.3.6.36. owing to the number of stud breakages which have taken place, and we are going into the matter from a design point of view to see whether we can overcome the trouble by some design modification. There is one other way of looking at the matter i.e. that the weight is not moving sideways freely, and this would result in stresses being thrown on the stud. We are, therefore, looking into this aspect of the matter to see whether some better arrangement can be devised to permit the relative movement between the spring leaf with its weight and the bumper bar, which would relieve the stud of the side loads which would result from the different movements of the spring and the curved bumper bar. BY.{R.W. Bailey - Chief Engineer} BY | ||