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).
Brake lining tests from the Gandy Belt Manufacturing Company, detailing the performance of 'SAFEGUARD' lining.
| Identifier | ExFiles\Box 141\3\ scan0013 | |
| Date | 10th July 1930 | |
| Particulars from the Gandy Belt Manufacturing Company Ltd. 10.7.30 "With regard to data ascertained by testing the material, most of our records are obtained by tests carried out in the National Physical Laboratories at Teddington but we might say that we have our own laboratories and testing shops and employ identically the same machines as those used at Teddington. The following are extracts from recent tests made in the National Physical Laboratory, and you will no doubt be interested to note that one of the chief features of "SAFEGUARD" Lining is that there is no diminution in the co-efficiency of friction as the temperature of the Lining increases in fact the remarkable fact is that as the temperature rises the co-efficiency increases. This is a most important point as you know in connection with the braking efficiency on Motor Cars. "Record of tests on samples of Brake Lining supplied by The Gandy Belt Manufacturing Co.Ltd., of Seacombe, Cheshire, 14th November 1929. Test Mark:- E.T.K Time. Average load Speed Temperature in strip °C Coefficient of friction Hr. Hr. lbs/sq.in. ft/min Average Maximum Max. Min. Average. 0 - 1 43.6 1990 146 195 .45 .29 .34 1 - 2 43.0 2040 153 186 .37 .33 .35 2 - 3 40.1 2020 153 189 .44 .34 .37 3 - 4 33.7 1990 153 194 .54 .36 .45 4 - 5 28.0 2030 187 221 .64 .41 .53 5 - 6 28.3 2030 181 217 .56 .51 .53 6 - 7 27.6 2050 199 246 .55 .51 .54 Mean 1 to 7 33.5 2030 .46 "Conclusions: The wear figure calculated for the second and third hours of the test is 0.0080 which agrees closely with the figure obtained in the wear test with cooled wheel carried out separately. As the wear increases the friction rises with increase of temperature and the friction value generally increases. The resistance to heat is very good, there being no evidence of the material braking up after 7 runs with a final maximum surface temperature of 230° to 250°C. "In connection with this test we enclose Blue Print of Chart showing the co-efficient of friction at varying periods with fluctuations of temperature, which kindly return at your convenience. (Continued) ENCLOSURE N° 165 'JUSTSO' | ||