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).
Description of a novel clutch-pedal gear change mechanism.
| Identifier | ExFiles\Box 136\4\ scan0132 | |
| Date | 9th February 1937 guessed | |
| "Novel Clutch-pedal Gear Change." As the article in THE MOTOR may not be very clear on one or two points, and the sketches are somewhat crowded, the following further description may be helpful in making the mechanism easily understood. The mechanism is a simple robust construction that provides a preselector form of control for synchro-mesh gears. Any number of speeds, forward or reverse, may be controlled and there are adaptations suitable for light, medium, heavy or very heavy duty. For example, a 4-sp.{Mr Spinney} and reverse gear, plus an overdrive gear and with automatic gear selection on the four normal speeds to facilitate getaways, is readily controlled by means of a small lever on the steering column, under the driver's eye and always indicating what is in use. For very heavy duty a gearbox with five forward speeds and one or two reverse gears is quite easily controlled without confusion and with very little effort. Short Description. The various gears engage on the lines of usual practice with a gear lever, the gear striking levers engaging the gears indicated in much the same manner as a gear lever does. As shown in the main figure of the sketches, in THE MOTOR article, the gear members are shifted by the pivoted striking levers which can be coupled by means of strong pawls (one for each speed) to the eccentric or self-change shaft. The selector shaft allows any one of the pawls to be so coupled, and prevents the other pawls from coupling. When the self-change shaft is partially turned, anti-clockwise, all the pawls are lowered and the pre-selected pawl engages with a step on the top bar of the striking lever. This makes a very strong coupling between striking lever and self-change shaft, the coupling action taking place when the clutch pedal is fully depressed. By allowing the pedal to return, either slowly or quickly, the striking lever is rocked and effects the gear engagement. | ||