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).
Material properties and heat treatment for the Phantom III contact breaker lever pins.
| Identifier | ExFiles\Box 61b\1\ scan0206 | |
| Date | 17th April 1937 | |
| Rm{William Robotham - Chief Engineer}/Wst. 6118. BY.2/G.17.4.37. PHANTOM III - CONTACT BREAKER LEVER. -------------------------------- Referring to Rm{William Robotham - Chief Engineer}/Wst.5/AP.12.3.37. we note your point in regard to the tinning of the brass pivot for the make and break lever. This practice has been corrected, but we note that there have been quite a number of pins in service which have been tinned. I should think the most likely trouble would be reduction of clearance. With regard to the question of the pins themselves, Delta metal is admittedly very much more ductile than the brass rod which we have been and are still using, but its ductility makes it undesirable from the point of view of a bearing material, and we have consistently in the past refrained from using Delta metal either as a pin or a bearing bush. The trouble with the brass pins was that they were being delivered on the hard side. We have now instituted a heat treating operation for the brass pins, which whilst it will not impair their bearing qualities will prevent the piece cracking as the result of cold working being left in the rod. We do not anticipate further trouble in this direction. BY.{R.W. Bailey - Chief Engineer} | ||