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 to the A.T. Speedometer Co. Ltd. regarding failures in the trip recorder mechanism and suggesting material and design modifications.
| Identifier | ExFiles\Box 165\2\ img008 | |
| Date | 19th January 1937 | |
| c. Rm.{William Robotham - Chief Engineer} 6051 19th. January 1937. BY.R/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} The A.T. Speedometer Co. Ltd., Chronos Works, North Circular Road, London. N.W.2. Dear Sirs, As you are aware we have had quite a number of failures, a matter of 18 in service during the last few months in the trip recorder mechanism of the speedometer. From an examination of one of the instruments which had failed, it would appear that two minor modifications are necessary. In the first place I am of the opinion that the little star wheels should be made in drawn bronze and not in aluminium, as the latter appears to be too soft for the purpose. Secondly, the slot with which the star wheel tooth engages in the barrel carrying the numbers of tenths of miles in the trip mechanism requires to be better formed, in fact it should be a correct tooth shape instead of the somewhat square slot with rounded corners which at present does this duty. We have had the trip recorder fail to record on three consecutive new speedometers taken from our Store, run in connection with oil consumption tests, on one of our production chassis, it is evident that this matter requires immediate attention. In view of the urgency of the above matter, we regret that you did not find an opportunity to come to our Works last week as promised, and we again emphasise the need for immediate attention to be given to this matter. Yours faithfully, FOR ROLLS-ROYCE LIMITED. BM TECHNICAL PRODUCTION ENGINEER. | ||