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).
Technical description and theoretical considerations of the 'Spontan' transmission system.
| Identifier | ExFiles\Box 41\4\ Scan040 | |
| Date | 21th September 1931 guessed | |
| [Page 10] SPONTAN driving sleeve then results in the driven sleeve being turned in the other direction, i. e.{Mr Elliott - Chief Engineer} the car is in reverse gear. For the purpose of reversing, the rollers are carried in cages which can be turned in relation to the sleeves by the driver, by means of the only control pedal of the car. To reverse, the driver raises this pedal slightly from its normal position. The brakes are applied by a powerful spring and are released by the first depression of the control pedal, a further depression of which causes the throttle to open. The spring force is suitably balanced so that the resistance offered by the spring gradually becomes less but never disappears, thus automatically replacing the pedal into the "brake-on" position when the driver allows his foot to be raised by the spring. On taking his seat behind the steering wheel of the Spontan-fitted car the driver finds the only pedal in its brake-on position. Having started the engine as usual he depresses this pedal, thus at first releasing the brakes. On further depression the accelerator is operated, the engine speeds up, and the car starts smoothly, the speed then being regulated at will by suitable depression of the pedal. Thus, on depressing the pedal he accelerates, on releasing it he slows down, until at full release the brakes are fully applied. It is convenient when handling the car in a garage to be able to release the brakes without having to depress the pedal and for this purpose a handle is provided accessible from outside the car. 10 [Page 11] SPONTAN THEORETICAL CONSIDERATIONS The working of the Spontan transmission will now be studied a little more closely. Assume that the car is at rest and the engine idling. The main driving sleeve is then stationary and the two bob weights rotate by means of ball bearings on their respective eccentric discs. Referring to Fig. 3, the turning moment on the sleeve will then be given by the distance e between the centres of the eccentric Fig. 3. discs multiplied by the component C. sin a of the centrifugal force C. Assuming uniform rotation, C is constant and the starting torque can therefore be represented by a simple sine curve as shown in Fig. 4. 11 | ||