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).
The unsatisfactory performance of tungsten contact points and related manufacturing difficulties.
| Identifier | ExFiles\Box 35\5\ scan 127 | |
| Date | 27th September 1920 | |
| To EWT. from EFC. X 2894 EFC1/AT27.9.20. X.2894.-TUNGSTEN POINTS. My answer to Mr. Olley's letter Oy3/G27820 is as follows:- We only received sufficient contact points of suitable diameter .125" from the Independent Lamp & Wire Co., for making up two sets of points. One of these ran about 1,000 miles on our experimental chassis 4KX but were unsatisfactory, the other ran on two experimental chassis, 49GB. and 6EX, and which also turned out unsatisfactory. The manner in which they were unsatisfactory is best explained by saying that these pitted, the points lost their flat surface and became uneven so that the point of break became uncertain. Both these sets of points were sent to and are still with Mr. Royce for his inspection. We will however, endeavour to get these back and will then hand them over to Mr. Tong for passing over to Mr. Olley for his inspection. With reference to Mr. Olley's further paragraph, we had stated that it was not possible for us to work the rods into contacts, and that therefore, we could only experiment with contacts which were already shaped. It is quite possible for us to braze a small cheese of tungsten into a soft iron rivet. We should be glad of any information which will enable us to work the rods into rivets which is necessary before the contacts can be made up. EFC. | ||