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 New-Hudson Ltd. concerning Girling brake tests, discussing results, issues with locking, and suggestions for future testing.
| Identifier | ExFiles\Box 120\3\ scan0168 | |
| Date | 3rd May 1935 | |
| x4456 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}5/KW. 3rd May, 1935. Messrs. New-Hudson Ltd., Icknield St.{Capt. P. R. Strong}, Birmingham 18. For the attention of Mr. Frazer. Dear Sirs, Thank you for your letter of the 18th. As regards travel of the wedges, we were using a pedal to cam ratio of 20 : 1, which with 3½" pedal travel will allow for more than 5/8" movement of the wedges. We think the tests we have carried out so far are spoilt by the inadequate size of the brakes, particularly those on the rear. We think however that a wrapping shoe of small arc of embrace is inevitably going to get hotter than with the orthodox arrangement. We should be willing to continue tests of the Girling brake if you have any of a larger size, suggesting 2" wide in front and 2½" at the rear. We should not, however, contemplate drums which without hubs weighed more than 12 lbs. and 16 lbs. front and rear respectively. There is one further point: on our car and on a car we know of fitted with Girling brakes, there has been a case of the rear brakes locking on. The brakes were freed by hitting the floating cam which had obviously jambed. We remember your telling us that if the cam were fixed the brakes would in all probability stay on. It seems therefore that the fulcrum is liable to stick and that the wedges should be so arranged as to free in the event of this happening. We remember your saying this could be done, and suggest this feature | ||