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).
Modifications to the S.S. Sequence Starter, discussing issues with non-taper armatures and performance of chassis 19-EX.
| Identifier | WestWitteringFiles\T\November1928\ Scan112 | |
| Date | 31th December 1928 | |
| To R.{Sir Henry Royce} from EFC. c. RJ. E.{Mr Elliott - Chief Engineer} Sg.{Arthur F. Sidgreaves - MD} c. HY.{Tom Haldenby - Plant Engineer} Ds. c. Wor.{Arthur Wormald - General Works Manager} CWP. S.S. SEQUENCE STARTER EPC2/T31.12.28. RL/M21.12.28. X7 625/SS{S. Smith} With the various modifications which we have made. e.g. (1) Suitably altered armature main spring. (2) Increased degree of radiusing on the disengaging edges of the pinion teeth. (3) Slightly higher rated pinion spring with feeble set, so that pinion is very easily pushed back. we have not experienced any failure more than the comparatively occasional necessity for a second application of pressure to the push button. The motor on chas is 19-EX Ogoing to France this week) is arranged in this way. It has, of course, the metallic thump on disengagement, but otherwise is working generally quite well. In regard to the abandonment of the taper, we have put this in hand, though personally we are of the opinion that we have not sufficiently proved the use of the taper to be wrong. It may be remembered that on our first trials of the EAC.7. arranged with a non-taper armature, one of our first difficulties was that the armature torque was too great in relation to the longitudinal pull and either - (1) caused the motor to spin fast without engaging, or (2) if engagement took place, caused so much pressure on the teeth that the longitudinal motion was interfered with through mechanical friction, and engagement up to the point of operating the armature-operated switch did not take place. This occurred in spite of the 5° spiral on the teeth. Also that the EAC.7. present arrangement is very nearly the same as regards degree of taper, and the use of parallel teeth. | ||