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).
Preselector gear change system with positive gear shifting, foot control, and power changing.
| Identifier | ExFiles\Box 147\3\ scan0170 | |
| Date | 25th October 1938 guessed | |
| PRESELECTOR GEAR CHANGE, with Positive Gear Shifting. The positive action is obtained by a very simple adaptation of a well proved method of gear changing as used in the foot control of motorcycle gears and, so I understand, as used on Eystons "Thunderbolt", to which it was fitted by Burman & Son of Birmingham and employed by Eyston to simplify the gear changing. The new development comprises a small fitting, on the outer end of the Control Shaft of the Preselector Gear Change, that gives the Control Shaft its forward and backward movement with positive action in each direction. When a pedal is used to engage the gears the pedal moves down to its limit and this movement first disengages the clutch and then engages the preselected gear by a positive action. A driver can engage the gears, either slowly or rapidly, with absolute certainty of their engagement the position of the pedal, as well as the 'feel' of the gears, indicating that the gears are engaged. He can then let in the clutch by allowing the pedal to come up in the usual manner. Normal use of the clutch is not interfered with as ample movement for this is provided by the fitting. FOOT GEAR CONTROL. As a means of shifting the gears foot operation is far better than any form of hand lever. Even on the unstable motorcycle foot control is ousting the hand lever: on the more stable car the better position of the driver makes foot operation the ideal method - just a push down of the pedal when the change is wanted. No other method is so simple or so effortless. Unlike the hand lever, foot control does not call for any sacrifice in the size and strength of gears or synchronising cones to facilitate its use; on the contrary the gears may be stronger and the cones larger and of the best form for efficient use. Foot control has the further advantage of having all the control members mounted close together on the gearbox casing. POWER GEAR CHANGING. Should this come into vogue the new fitting greatly simplifies and facilitates its use. In my arrangement the preselector gear is moved into the notch of the desired gear and, when the actual change is wanted, the lever is momentarily pushed downwards to complete the change. | ||