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).
Blueprint and explanation of an optional self-selecting gear mechanism for getaways.
| Identifier | ExFiles\Box 147\3\ scan0135 | |
| Date | 1st August 1938 guessed | |
| Optional Self-selection of the Gears during Getaways - from Neutral to Top. DIAGRAM LABELS: Preselector Lever Tilted for Self-selection H2 H Fixed Quad. Preselector Lever in Normal Position H3 H1 To Steering Column Connected to Toothed Sector Lever Connected to Pawl Control Cam Toothed Sector Lever Pawl P operative Pawl Control Cam Pawl P inoperative PC Link Pawl Control Shaft Selector Shaft Toothed Sector Ratchet on TS P C MAIN TEXT: A small addition to the normal preselector lever control removes the necessity for using the lever when getting away after stops, the mechanism itself selecting the gears. This makes the getaway easier quicker and safer as the driver, having no gear lever to bother with, can keep both hands on the wheel and give all his attention to the road and traffic at a time when a little extra care is often needed. As shown above the lever is formed in two parts, H H1, hinged together at H2. In normal use both parts move together horizontally over the fixed quadrant and turn the Selector Shaft through the toothed sector, as indicated. The inner end of lever H connects to a cam C and this cam normally keeps a pawl P inoperative. The pawl carrier PC is linked to the Control Shaft. Self-selection is brought into use simply by tilting the lever H, as indicated at H2. This moves the cam C to allow the pawl P to become operative. As the pawl carrier PC is linked to the Control Shaft it moves with the shaft when the latter is given a partial turn to make a gear change or unwinds a gear (see Figs 5 and 6) and this causes the pawl P to move the toothed sector and so turn the Selector Shaft to select the next gear in the sequence, the gear so selected being engaged by the return movement of the Control Shaft. This arrangement avoids any confusion when normal control is resumed. The preselector lever keeps in step with the changes, always indicating the gear in use, and normal hand control can be restored instantly. The lever H is so arranged that it must be either up or down and it is easily flicked between its two positions, this being done at leisure before the getaway and when in top. The lever is not touched during the getaway. In "clutch-pedal" control each change is effected simply by fully depressing and releasing the clutch pedal. | ||