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 and calculations for a strengthened cross steering tube ball joint design.
| Identifier | ExFiles\Box 80\1\ scan0026 | |
| Date | 22th April 1916 | |
| ST.{Capt. P. R. Strong} MARGARET'S COPY. x 3126 22.4.16. Re Cross Steering Tube Ball Joint Strengthened Design I send herewith LeC.537 and 540, showing the proposed modifications to the Ball Joint and some calculations with regard to them. The particular point to notice is that the weakest part of the joint in the neck of the ball, section J-J.{Mr Johnson W.M.} In the old joint the strength of the ball was rather difficult to determine, because the strength at the section D-D (at the top of the hole) depended on whether the fitter had so reamed the taper hole that the flange was pulled down into good contact with the boss on the lever. In this latter case the flange undoubtedly took part of the bending load. If the flange were not in good contact however the section D-D took all of the bending load and was a very weak spot in the joint. To get away from this uncertainty we are proposing as you see, to use a 1 in 6 taper shank without a flange. In order to guarantee good contact the shank is ground and polished and the hole is reamed (under a jig to keep the reamer square) till the shank, or a taper gauge representing the shank, pushes firmly into the hole to a position .050 (or .025 see on) from its final position. It is then forced up into position under the hydraulic press. The boss on the lever has been increased in depth at the expense of the nut, which, on the old design, in unnecessarily deep. R.R.A 238 (400 T) (S.C. 536. 15-2-16) (G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1546). | ||