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).
New gearbox design, including its actuation, shaft, and casing, with comparisons to the Phantom III and Wraith models.
| Identifier | ExFiles\Box 136\4\ scan0169 | |
| Date | 16th July 1937 guessed | |
| (2) found to be very desirable, and we shall be sending a further design for the spring. N.Sch.5199 shows the over-drive, direct, and reverse actuation. We have not followed the type of actuation in use on the existing Phantom III overdrive box as we consider that what we show is more satisfactory from various points of view. Our scheme gives a high leverage at the synchronising position falling to a low leverage as the gear goes into mesh. The rocking shaft is common to both over-drive and standard ratio actuation with a different lever for each, but on further consideration it appears possible to combine the lever and rocking shaft and yet use the one piece for both types of box. We suggest that the detailing of these features is made the last job so that we may have an opportunity of making this simplification. N.Sch.5200 shows the actuating mechanism. Owing to the servo being on the opposite side from that on the Wraith a number of the pieces have to be handed, although otherwise identical with the Wraith pieces. The change gear shaft is arranged to suit a gear lever on the right hand or on the left hand side of the car. With a Wraith length of lever the travel of the knob of the lever into the gears is the same as for the Wraith, i.e. 3.5" into the two highest gears and 4.0" into the 1st and 2nd. There is no centralising spring on the gear lever but instead a spring presses the lever always to the top gear side of the gate. The original reason for the centralising spring does not now exist on the top gear side, and we think that the altered spring arrangement will be preferred. N.Sch.5201 gives views of the gearbox casing. The thickness should be the same as for the Wraith, i.e. .175". The speedometer drive is placed beneath the servo | ||