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).
Clutch experiments and a proposal for a progressive clutch design using multiple springs.
| Identifier | Morton\M11\ img131 | |
| Date | 23th January 1919 | |
| To EH. from E.{Mr Elliott - Chief Engineer} Copy to RA. " " RY. " " EFC. ORIGINAL RECEIVED 6 JAN 1919 RE CLUTCH EXPERIMENTS. A characteristic of the common methods of operating clutches to-day, is that the movement of the pedal lever from the condition when the clutch is just engaged to get the car away, to the condition when the clutch is fully engaged, is very small. Mr. Royce believes that he and others may have already tried a scheme in which a modified spring pressure was first brought to bear on the clutch, which would be strong enough to get the car away easily, but would allow the clutch to slip under the maximum engine torque. A further movement of the pedal lever would allow full clutch spring pressure to come on. One crude way of carrying this out would be to put a tension spring on the existing pedal lever of the 40/50 chassis, using a weaker central spring within the clutch. For the purpose of getting away, the weak central spring would operate on the clutch, and when the pedal were allowed to come finally to the top of its stroke, the spring attached to it would actually add to the clutch driving load by pressing on the pedal thrust bearing. This example is only quoted in an illustrative manner, but it is clear that a clutch could be designed which had multiple springs, in which the spring pressure could be engaged progressively. The effective stroke of the clutch pedal would be made much longer for this. (Contd.) | ||