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).
Modifications to a gear changing mechanism, including a free wheel ratchet and a positive jaw clutch.
| Identifier | Morton\M11\ img149 | |
| Date | 11th March 1919 guessed | |
| To EH. from R.{Sir Henry Royce} CHANGING GEAR CONTD. (2) R6/G11319. the side shaft carrying the wheels. The engine then accelerates the clutch, and takes up the drive, but possibly with a slight shock, unless the clutch is carefully manipulated or the ratchets of the free wheel are of very fine pitch. With a good clutch and a fine pitched ratchet we believe that this arrangement if a very good one, and could be adopted except for the fact that the car would overrun the engine down a hill, and from a danger point of view this may be considered undesirable, as the engine provides a very reliable brake on a very rapid down grade. I have therefore added to this arrangement a many toothed positive jaw clutch of the gear wheel type, which synchronises with the pawl of the ratchet of the free wheel and is so controlled by either the clutch pedal or the change speed lever, or even electro-magnetically, that it falls into mesh when the engine takes up on the free wheel. Such an arrangement appears to be fairly simple and positive, does not require any care in changing gear, and apparently does not require any time period in changing down. The changing up is the same as at present, and does not seem to present any difficulties to the novice. In addition to this design, we have schemed many modifications, one using sufficient friction to synchronise the gears by a friction clutch and a jaw clutch somewhat in the same positions. You will see therefore that the matter has had some attention, and we are proposing, if the advantages justify the complication, to make an experimental set as suggested above. Mr. Southern might take out the necessary patents for the scheme suggested of the combination of free wheel (ratchet) H H 522v (200 L) (2'D '09: 80+11) BW: S12P0L2 (Contd.) | ||