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).
Specification for an instrument to record car wheel revolutions against a time scale.
| Identifier | ExFiles\Box 138\2\ scan0001 | |
| Date | 12th February 1924 | |
| SPECIFICATION OF INSTRUMENT FOR RECORDING THE REVOLUTIONS OF THE WHEEL OF A CAR AGAINST A TIME SCALE. RECORDING MECHANISM. We require all the record strips to be capable of being analysed by the naked eye. As there will be a considerable length of strip, owing to the rate of feed being high, we suggest that it is kept as narrow as possible. We should like the time recording portion of the apparatus to mark the time in seconds and 1/10 of seconds. The maximum number of revolutions of the wheel which we wish to record will be 30 per second. If the instrument is to be satisfactory, there will have to be no lag between recording consecutive revolutions of the wheel at this speed. If this can be accomplished using a celluloid strip and some form of marker operated by an electro magnet, so much the better, otherwise we are confronted with the alternative of a composite strip and a H.T. spark punching a hole in the paper. We understood, however, from previous conversation, that 60 per sec. is within the compass of the former method of operation. FEED MECHANISM. We require the recording strip to be fed in at a normal rate of 1 inch per sec. - a minimum rate of ¼" per sec. and a maximum rate of 3 ins. per sec. It would be a distinct advantage if the rate of feed when set, were to be maintained approximately constant. As at the high rates of feed there will be a considerable length of record to be disposed of, we suggest that after taking the record, the strip should be wound on a drum driven by some sort of slipping clutch which would put a light tension on the strip. The longest record which we are likely to wish to take will, at the higher rate of feed, be about 6 ft. MAKE & BREAK MECHANISM. We will construct ourselves. ----------------- | ||