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).
Cross-sectional drawing of a piston assembly with design notes.
| Identifier | ExFiles\Box 64\4\ scan0178 | |
| Date | 15th February 1929 guessed | |
| (3) Treatment of collar saves dia. This space is about 75% of the stroke. About .6 - i.e. 80% undamped. About .25" Main switch contact make - don't like idea (EFC's) of making this early: desire complete engage-ment before great torque. Ths piston could go all the way and be relieved by air escape holes which would close near the ends. The piston ring shewn is to create some friction which would be good if not excessive and was fairly constant. Intended for air but should have some oil. 3 spring plungers together - slightly less force than Probably even pull and possibly about half armature weight. X7651 | ||