Specification sheet detailing measurements and ratios for a Duplex Push Button Switch.
| Identifier | ExFiles\Box 64\3\ scan0284 | |
| Date | 15th July 1926 | |
| x 7630 15.7.26. DUPLEX PUSH BUTTON SWITCH. Fulcrum to button .825" Fulcrum to copper contact. 1.187" Fulcrum to carbon contact. 1.500" Ratio copper contact arm button arm = 1.439 θ Ratio carbon contact arm button arm = 1.818 ∅ Ratio carbon contact arm copper contact arm = 1.264 ψ EFC {E. Fowler Clarke - Electrical Engineer} /HEW. | ||
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).