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 analysis of actuator box and pinion engagement angles for a sequence starter.
| Identifier | WestWitteringFiles\Q\2-July1927-September1927\ 64 | |
| Date | 26th August 1927 | |
| Contd. -2- EFC2/T26.8.27. actuator box. There is thus a limiting angle for this condition which may be about 25°. With a spiral of larger angle than this amount, the pinion will wind in on the teazer current and in that case a switch not making contact until full engagement has occurred (such as the pinion operated switch) is necessary; otherwise a big thump is produced by the main current winding the pinion into full gear. Below that limiting angle it is necessary, to get functioning at all, to use a switch of the actuator box operated type, making contact before the travel of the actuator is complete. As far as we can see at present, and speaking of this particular type No.1 scheme sequence starter, an angle something between the 20° now being reported and the 5° used on the rig tests (reported in EFCL/T8.7.27) is desirable, say about 10°. No angle in this range will allow the motor to engage the pinion completely with the teazer current. The angle in the 5° case appears to be too small because the actuator box may put the pinion in smartly (against no resistance), and make a big click. With the 20° case, on the other hand, the actuator box cannot, in putting in the pinion, immediately complete its travel owing to the pinion teeth coming in contact with the wheel teeth on the non-driving side, but is delayed until the motor by turning slowly allows it to do so. The click therefore is avoided. Only about half of the actuator travel is completed (nearly instantaneously) on switching on the actuator current. The remainder is taken up comparatively | ||