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).
Communication regarding the design of a ball pin attachment for the front shock absorber on a 40/50 HP chassis.
| Identifier | WestWitteringFiles\C\June1919\ Scan21 | |
| Date | 26th April 1919 | |
| To BA. from E.{Mr Elliott - Chief Engineer} Copy to CJ. " " BN.{W.O. Bentley / Mr Barrington} [struck through] " " RY. [struck through] " " EH. [struck through] " " EFC. ORIGINAL RE 40/50 H.P. CHASSIS - FRONT SHOCK ABSORBER. RECEIVED We send you herewith drawing No. B.C.1101 as promised, illustrating the details of the ball pin attachment to the front axle for the above. After much consideration it was decided to provide no locking for the nut securing this pin. It was thought that the load would never reach the degree of tightness to which the 1/2" nut would attain, and would therefore not be able to loosen it. The number of threads per inch should be 20, in accordance with our No. 2 standard for fine threads. If any trouble should be experienced, however, with this nut working loose, it should be castellated in the ordinary way, and two holes for the split pin should be provided in the bolt stem at 90°. This arrangement gives 12 positions in the circle, corresponding to an endway movement of the nut of .004" steps, which is too coarse to be satisfactory. Would you kindly compare the strength of the bending moment section along the stem of the ball pin with the strength of the screwed stem in tension, assuming, however, that the latter stress is not a symmetrical one, but is distorted by heeling off the edge of the ball pin flange. This communication should complete the information required by you on this matter. E.{Mr Elliott - Chief Engineer} | ||