Letter concerning the supply of tungsten contacts for testing and issues with pitting on platinum contacts.
| Identifier | ExFiles\Box 34\1\ Scan202 | |
| Date | 9th December 1920 | |
| X.2512 Oy2/G9.12.20. Dec. 9th, 1920. Mr. Claude Johnson, Managing Director. Rolls-Royce Ltd. London, England. Attention Mr. Clark. Dear Sir:- X.2894. X.2512. X.2430 RE TUNGSTEN CONTACTS. X 2512 X.3129 We are sending to Mr. Clark, 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. Clark 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. Clark 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 neighbourhood 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. Clark 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 com-plaints of was not the fault of the Tungsten but the condenser. Contd. GOSS 'D'(10M-8-'20) 10041 H&S.Ltd.G0321 *FRS. 'E' '20 | ||
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).