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).
The operation of a clutch and gearbox system, including gear changes and starting procedures.
Identifier | WestWitteringFiles\U\August1930-November1930\ Scan182 | |
Date | 11th November 1930 | |
-2- from rest except by holding the gear lever against the gear while pressing the clutch pedal. This may shift Y into a position for engagement. Starting from rest. A gear having been engaged by (1) or 3 (c) (3c. is a position in which the clutch is out but the Salerni engaged). Releasing the pedal after (1) may engage the coupling or not. When it does not it is due to the speed of X being too great for engagement. If it does not engage further depression of the clutch pedal engages the coupling into position 3 (c) with considerable shock. For starting in reverse 3c. must always be obtained and can only be obtained in a forward gear due to the chamfered lead in edges of Y acting as a throw out in reverse. After changing gear on the road. Down and releasing the pedal the coupling does not engage until the engine and hence X has aquired the correct speed. Under this condition the drag of Z or Y is counter acted and the coupling engages. It is very easy to overshoot the correct speed and the coupling does not engage. The coupling can also be engaged by depressing the pedal into position 3 (c) when it engages with an appreciable shock. Changing gear. This is meant to be effected by fully depressing the clutch pedal so that the gear box is isolated. The clutch stop should then bring to rest the clutch member and a bronze core brake stops the sliding Salerni dog, so that the whole gear box mechanism is stationary. The action of the core brake was, we found, insufficient due to a speed up device of spring loaded friction plates between the sliding member and the synchroniser ring. We therefore weakened this speed up effect and also made the bronze brake more effective by a slight alteration. We now find that we can engage any gear even reverse at any speed by the following method - The clutch pedal is depressed violently to its full extent, the gear lever being left in gear till the pedal is fully depressed. The Salerni brake has then stopped | ||