Supplementary note discussing issues and improvements for a servo-brake mechanism, particularly regarding noise and action upon release.
| Identifier | ExFiles\Box 12\5\ 05-page124 | |
| Date | 12th July 1929 | |
| OY. It appears necessary to supplement the above by the following:- (1) What has been said above (namely that for quiet brake release the front stop must close before the rear stop and that this condition is improved by raising the pivot center of the Tee lever) applies at present only to release after forward motion. (2) When releasing after reverse motion the problem of eliminating clank appears more difficult. We find in this case that the front stop closes with a loud "crack" before the servo action is released and while the rear stop is still wide open. (3) I suggest that this can be explained by the relative inclination of the reverse servo rod A-B and the Tee lever suspension link C-D. {John DeLooze - Company Secretary} (SK-347) As the servo action is reduced by release of the pedal it is desired to lower the Tee lever gradually and so to close first the front stop and then the rear stop. With the forward-motion servo rod E-F this is easily accomplished, but as the servo effort is released in A-B it is possible for the whole Tee lever to swing forward about C with little or no movement of the point A, and therefore without any restraint from the servo-friction. One can actually see this occur when the brakes are released after running in reverse. (4) I have endeavored to show in SK-347 an L-shaped equalising lever G-H-K-L which maintains approximately the present proportions, but are inclined towards each other so that I think it would maintain in reverse motion the essential condition of closing the front stop gently before the rear stop is closed. (5) A further proposal is shown as a sketch in SK-347 in which the reverse servo-rod is dispensed with altogether. Supplement to OY-10, July 12/29. | ||
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).