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).
Specifications and calculations for a contact mechanism, including dimensions, ratios, and gap tolerances.
| Identifier | ExFiles\Box 64\3\ scan0282 | |
| Date | 13th July 1926 | |
| 13.7.26. 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 ø Ratio carbon contact arm / copper contact arm = 1.264 ψ Position. Button depression. Copper gap. Carbon gap. Off. .012 + .000 .035+5-3 .019+13-8 Carbons in contact .012 + .010+7-4 .020+3-5 0 Coppers in contact. .012 + .023+4-2 0 0 .012 = initial button depression. BY/RD. | ||