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).
The performance of a new drive system, including its hill-climbing and braking capabilities.
| Identifier | ExFiles\Box 52\3\ Scan372 | |
| Date | 28th August 1919 | |
| Oy10-F28.8.19-6 the "get-away" with the engine racing was slow, and gave the impression of a badly-slipping belt on a motorcycle. 15. No foot-brake was fitted. Instead the speed lever, on the steering column, was put over to reserve, and pressure of the foot on the accelerator pedal then controlled the amount of braking effect when descending hills. If the car was brought to a standstill in this way when descending a hill, it was possible to have it run back again up the hill, either intentionally or otherwise. 16. The car climbed hills excellently on any of the four speeds, lower speeds being put in as the engine showed signs of laboring. 17. With the commutator cover removed, no signs of sparking could be seen. The brushes (of hard copper-graphite mixture) were smooth and only slightly worn, and the commutator sectors showed no grooving after, I believe, some 10,000 miles of running. 18. The device was silent. The air gap between the motor armature and fields is reduced to the smallest possible, while that between the two armatures is about 3/16", to avoid flutter and humming (the flux-density is considerably lower in the outer air gap). 19. The device as installed experimentally on the Chalmers car, having no double pole pieces, and similarly arranged windings on the two armatures, was only capable of speeding up the propeller shaft say 30% faster than the engine, due to slight differences in the two armature windings. 20. I think I have covered the main points of the device. I hope shortly, however, to see the greatly improved device, as fitted experimentally to the Cadillac car, and will report on this. This fitting on the Cadillac, will weigh about 550 lbs., and for a Rolls-Royce it would prob- | ||