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).
Page detailing modifications to a P.B. Switch regarding spigots, bosses, and covers.
| Identifier | ExFiles\Box 34\3\ Scan045 | |
| Date | 10th September 1919 | |
| P.B. S-witch. -2- 10.9.19. out the locating spigot S.S. and in futures switches by facing off the boss b, if the length of this boss permits; and if not, to increase the depth of the cover, so as to give the necessary room for the larger headed plug to be fitted without making the carbon gap in the "off" position too small. | ||