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).
Detailed description and explanation of the Spontan transmission system, including a diagram.
| Identifier | ExFiles\Box 41\4\ Scan043 | |
| Date | 21th September 1931 guessed | |
| SPONTAN in indirect and direct drive, is that great smoothness and flexibility is obtained by the employment of centrifugal forces for creating the driving torque. The curves in Figs. 8 and 9 represent the tractive force at the driving wheels at various speeds. Fig. 8 shows the curves for a car on each of the 3 gear-ratio speeds and Fig. 9 the equivalent curves with the Spontan gear. Vertical shading represents indirect drive and horizontal shading corresponds with direct drive. The change over from direct to indirect drive takes place at a lower speed than the change in the opposite direction. This is due to the fact that the weights after working on direct drive are at rest in the outward position and before they can be set in motion again the force necessary to overcome the centrifugal force acting upon them in this position must be supplied by the engine. 16 SPONTAN DETAILED DESCRIPTION OF THE SPONTAN TRANSMISSION The Spontan gear described in detail below is, in this special case, fitted to a 55 h.{Arthur M. Hanbury - Head Complaints} h.{Arthur M. Hanbury - Head Complaints} p. Essex Super Six car. Its working parts are enclosed in a light-metal casing bolted to the crank case of the motor as shown by Fig. 10, the position of the control pedal being clearly indicated by Fig. 11. Fig. 12 shows a longitudinal and a transverse section of casing and internal parts. 7 is a part of the engine fly- Fig. 10. wheel carrying the toothed ring 9 for engagement of the starting motor. The engine torque is carried through the central shaft 4 to the rear end of the gear box and then back through 17 | ||