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).
Reliability of switches, accumulator switch design, and improved materials for contacts.
| Identifier | Morton\M16\ img041 | |
| Date | 20th October 1921 | |
| TO MPU. from R.{Sir Henry Royce} 20.10.21 Contd. Regarding the switches, Mr. Hives reports that there has been no direct evidence of these failing to work. My own impression, however, was that they were hardly as reliable as is desired, owing to the very short length of the flexible part of the contacts. Regarding the automatic accumulator switch, the magnetic principle embodied in the experimental one sent is undoubtedly better than the single coil type. We notice, however, that this particular polarised type was made by the Westinghouse Company of America some long time ago. Whether the Westinghouse have a patent for this scheme I do not know, but I should doubt if any such patent would be valid, as it embodies such well known principles and probably used on some of the earlier accumulator switches. Regarding the contacts, we think something better than copper should be used, and should prefer a combination of carbon and silver acting in the usual way of the carbon making the circuit slightly in advance of the silver, and breaking it slightly in retard of the silver. I should be very pleased to see specimens of the new switchbox with the new type of accumulator switch, and as soon as this can be purchased not one of the old ones should be fitted, and as quickly as possible we should make the change on all existing cars to this improved type, fitting the spring to give and control the tension of the belt at the same time. In conclusion, the items to fit promptly to new and existing cars are, switchbox with really good accumulator switch and spring fixing tension of dynamo belt. R.{Sir Henry Royce} | ||