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).
Test report comparing 20° and 5° spiral gears for an actuator switch mechanism, proposing an update for chassis 9-EX.
| Identifier | ExFiles\Box 64\3\ scan0119 | |
| Date | 8th July 1927 | |
| Contd. -4- EFCL/T8.7.27. With the observations hole provided it is possible to place the relation of the pinion on the spiral to the wheel in such a manner as to produce an artificial jam, i.e. the application of the teazer current would then have no effect, the juxta-position of the teeth being as in diagram :- This action normal to spiral. This was very readily possible in the 5° case but, thought not impossible, it was found to be much more difficult in the 20° case. From these tests it would appear that the 20° spiral is superior to the 5°, and that it would be more satisfactory on a car with the actuator box operated switch making contact at early engagement. For this reason we are proposing to have this arrangement fitted to chassis 9-EX which is at present fitted with a 34° 52' spiral with pinion operated switch. The degree of noisiness is not readily judged from the rig tests. † including push of actuator box. EFC. | ||