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 Ferodo Limited discussing the causes of and potential solutions for squeaky brakes.
| Identifier | ExFiles\Box 26\4\ Scan185 | |
| Date | 29th October 1923 | |
| H30209 X719 FERODO LIMITED. WIRES: "FRICTION, CHAPEL-EN-LE-FRITH." REGD TRADE MARK. TELEPHONES: 19 & 20 CHAPEL-EN-LE-FRITH. (2 LINES) Depots. LONDON 222, TOTTENHAM COURT ROAD, W.1. BIRMINGHAM 202, CORPORATION STREET. MANCHESTER 28, CATHEDRAL STREET. BRISTOL 19, PARK STREET. BELFAST 158, NORTH STREET. LEEDS 25, HUNSLET ROAD. MESSRS T.S. ARMSTRONG & CO LTD, NEWCASTLE ON TYNE WORSWICK STREET, PILGRIM STREET. MESSRS HART, OSWALD LIMITED, GLASGOW, 39, BOTHWELL STREET. MESSRS HASLAM & STRETTON LTD CARDIFF, 11, WINDSOR PLACE. MESSRS HASLAM & STRETTON LTD SWANSEA, 33, ST HELENS ROAD. MESSRS J.{Mr Johnson W.M.} McCONWELL FERODO LTD LIVERPOOL. 60, DRURY BUILDINGS, WATER ST MS A.J. CRESWICK, SHEFFIELD. GATEFIELD. MESSRS F.W. HARRIS & CO STOKE ON TRENT, MOORLAND ROAD BURSLEM. MR SIDNEY HILL, COVENTRY. FERODO FRICTION LININGS. CODES:- 5TH EDITION A.B.C. LIEBER'S. MARCONI INTERNATIONAL. WESTERN UNION FIVE LETTER EDS. Regd Office & Works, SOVEREIGN MILLS, CHAPEL-EN-LE-FRITH, ENGLAND. PLEASE ADDRESS YOUR REPLY, DEPT. REF. FJF/DHL. YOUR REF. Hs{Lord Ernest Hives - Chair}2/LG. 29th October, 1923 (Monday). Messrs Rolls Royce Limited, Nightingale Road, D E R B Y. Dear Sirs, We duly received your letter of the 24th inst., and shall be pleased to help you in any way possible in the direction indicated. The unpleasantness arising from squeaky brakes, in the majority of cases, is of quite recent occurrence within the past six months. It did not appear to exist at all in 1922, though in conversation with members of your technical staff, we recall mention being made of a slight groaning noise from brakes, just prior to a car coming to rest. In a general sense, we agree with you that the cause of the noise arises from vibration of drum. Deep light section drums, which have no out-turned flange at the open end are noisier than those of more substantial construction. The outstanding example of noisiness is surely forthcoming from the Morris car brakes, some of which can be heard whistling at very long distances. Some of these cases we have cured by fitting our Die-Pressed FERODO BONDED ASBESTOS, but it does not always prove entirely successful, and only yields temporarily to lubrication and more permanently to mechanical damping. It appears to us that the coefficient of the friction of the lining material if reasonably high produces a peculiar condition of tension on the steel surface of the drum, and we find that increasing the pressure increases the volume of sound emitted. We investigated a case quite recently, and found that a certain piece of lining emitted a loud piercing squeak without intermission for several hours on end at any velocity of slipping and increased with increase of pressure. It was an unique experience with us, for the MOTOR EXHIBITION OLYMPIA Nov: 2nd - 10th. OUR STAND No 493 | ||