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).
Gear engagement difficulties related to the Salerni coupling and cone brake.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan183 | |
| Date | 11th November 1930 | |
| -3- both the third and first motion shafts and any gear can be engaged. This does not always happen because of the Salerni coupling not being fully engaged before commencing to change of gear. Under that condition the cone brake is inoperative. We find that the coupling does not engage freely until one has altered from drive to over-run several times to allow the dogs to come freely into mesh. There is a torsion spring which should allow the clutch pedal to return even if the Salerni dogs prevent the coupling engaging. This spring is too strong at present and we get considerable clutch slip but weakening it will have another bad effect, as there will be less force tending to pull the Salerni coupling into full engagement by the action of the clutch springs on the clutch pedal. An improvement might be effected by making the Salerni brake more effective with less effort at the clutch pedal but when that has been done there are difficulties we cannot overcome - (1) Engagement of reverse gear in cases where one's forward movement of the car is limited. (2) The case of over-shooting the speed at which the coupling automatically engages. Hs{Lord Ernest Hives - Chair}/H.Grylls. | ||