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).
Failure of a tappet bolt nut to bed squarely and proposing tests with a spherical washer.
| Identifier | WestWitteringFiles\A\May1917\ Scan9 | |
| Date | 23th May 1917 | |
| To By.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} c. to J.{Mr Johnson W.M.} c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to EH. ORIGINAL R1/B22:5:17. 23 MAY 1917 4 X. 3058 Re Tappet Bolt. X. 2553. With reference to the tappet bolt, on the one we have here the nut does not bed squarely, and therefore the end would probably be broken off even if the split pin were omitted. Would you kindly have some tested with a spherical washer, so as to be sure that it is square, and let Mr. Hives find out how difficult it is to break the end off under the following conditions (1) With the drilled split pin hole, and without. (2) With the plain nut, and face slightly out of square. (3) With the same fitting as (2) but with the spherical washer. I have no objections to the split pin and castellations being deleted. It was not noticed that they would do any harm and we thought if it was found that the adjustment worked loose we should be glad we had got them. As the matter stands, and it has now been proved that the adjustment does not work loose, the castellations can be left off. We think the best way of fitting the spherical washer would be to sphere the bottom of the nut and provide a washer with the clearance hole on the screw to fit it. The washer should be made fairly hard by heat treatment, between 300 and 400 Brinell. It would be as well also to ascertain how strong the threaded part of the adjusting screw is. R.{Sir Henry Royce} Use Brinell of 321 in b.v.s for washers. Sgd By | ||