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 a tyre supplier proposing two methods for measuring the power loss of tyres using dynamometers.
| Identifier | ExFiles\Box 156\3\ scan0176 | |
| Date | 1st September 1939 | |
| ESTABLISHED 1885 [Logo with text: AVON SYMBOLS OF ENDURANCE] The AVON INDIA RUBBER CO. Ltd. CHAIRMAN MAJOR R.F. FULLER, J.P. DEPUTY CHAIRMAN SIR HERBERT E.{Mr Elliott - Chief Engineer} BLAIN, C.B.E., M.INST.T. JOINT GENERAL MANAGERS R.H. COMLEY. O.F. SWANBOROUGH. SECRETARY & ACCOUNTANT E.H. LOVELL, A.C.I.S. SERVICE DEPOTS, LONDON BIRMINGHAM BRISTOL MANCHESTER NEWCASTLE GLASGOW BELFAST. LONDON OFFICE, MABLEDON PLACE, ST.{Capt. P. R. Strong} PANCRAS, LONDON, W.C.1. HEAD OFFICE & WORKS, MELKSHAM, WILTS. Telegrams RUBBER MELKSHAM. Telephone MELKSHAM 120 (6 Lines). Codes ABC. 5th EDN. WESTERN UNION, BENTLEYS & MT. PRIVATE CODE. [Handwritten]: GRY.{Shadwell Grylls} 1331 JGM/NAW. 1st September, 1939. Rolls Royce Ltd., DERBY. Attention:- Mr. W.A. Robotham. Dear Sirs, We have been giving consideration to the measurement of the power loss of tyres and have concluded that we should follow either of the following methods:- (1) Through one tyred wheel, mounted directly on the spindle of a 50 H.P. 3/1 Speed D.C. Motor we would drive a drum to which is attached a Froude hydraulic dynamometer. The motor would be of completely known characteristics and power input would be measured by readings on ammeter and voltmeter. As an additional refinement we might insert on the input side a torsion meter to measure the power input. The tyred wheel would carry a platform to which loads could be applied. The power transmitted would of course be measured by the Froude hydraulic dynamometer. (2) Alternatively we would drive by means of a Froude 50 H.P. electric transmission dynamometer one tyred wheel against a drum which would again be connected to a Froude hydraulic dynamometer. The electric transmission dynamometer is of course essentially a motor mounted in trunnions and fitted with a torque arm. This arrangement would give accurate direct readings of the power input:- 3/1 Speed variation has been assumed at speeds from 500 R.P.M. to 1500 R.P.M. We would be glad to have your comments on these proposals particularly in regard to the capacity of the motors. We would also like to learn the position of your road tests on our Standard tyres modified to reduce irregular wear and on the last set of tyres we submitted for your "Corniche" model. Yours faithfully, THE AVON INDIA RUBBER COMPANY LIMITED. p.p. J.G. MACKAY [Signature] DEVELOPMENT MANAGER AND CHIEF CHEMIST. | ||