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).
Letter from the American division concerning the supply and testing of Tungsten contacts for battery ignition systems.
| Identifier | ExFiles\Box 35\5\ scan 160 | |
| Date | 9th December 1920 | |
| X.2894 Oy2 - G 91220 Dec. 9, 1920 Mr. Claude Johnson, Managing Director, Rolls-Royce Ltd., London, England. Attention: Mr. Clarke. Dear Sir:- X 2894 X 2512 X 3124 Re: Tungsten Contacts We are sending Mr. Clarke, enclosed in an envelope herewith, six each of the contacts used on our battery ignition, made up for us in their special Tungsten alloy by the Fansteel Products Company of Chicago. These people are the makers of the Tungsten rods which were brought over to England last winter but which Mr. Clarke was unable to use because of inability to machine the rods. At their own initiative they have made up the contacts for our tests. We should therefore be pleased if Mr. Clarke could find it convenient to send us a report on these at his earliest convenience. With reference to the use of these contacts, I have been informed by the engineer of the Westinghouse Electric Co. that they do not reckon to get the best results from Tungsten contacts on battery ignition unless the running current, at ordinary road speeds, is in the neighborhood of 1 ampere or less. This applies to 6 volt ignition and to contacts probably somewhat smaller than our own - perhaps 75% of the area. Perhaps this might explain the trouble that Mr. Clarke previously had with these contacts. Another matter I would draw to his attention is that we are having considerable trouble, both here and at Derby, with pitting of the platinum contacts, due to condenser defects, and would therefore suggest that possibly the pitting which he complains of was not the fault of the Tungsten but the condenser. In any case, I think that Mr. Clarke would be interested in experimenting with the enclosed contacts. MO/G Yours truly, ROLLS-ROYCE OF AMERICA, Inc. CC Mr. Hulley Enc. 12 contacts Per M.{Mr Moon / Mr Moore} Olley | ||