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).
Technical drawing detailing a cross-section of a worm gear with specific dimensions and machining notes.
| Identifier | ExFiles\Box 170\2\ img099 | |
| Date | 1st October 1931 guessed | |
| RELATION OF KEY TO THREAD AS SHOWN .960 / .954 BORE BEFORE BROACHING SCALE - DOUBLE SIZE ¢ OF WORM CONES TO BE GROUND FROM THIS CENTER ¢ OF 22 TOOTH CUTTER 1/8 CHAMFER NOT OVER 1/8 R THIS CORNER TO BE SHARP SCALE - 4 TIMES SIZE 8.2390 40° .24 / .32 .100 1.562 / 1.556 DIA 1.851 / 1.883 14° 48' 114° 48' 30° .007 / .003 .025 / .035 IMPERIAL TRACING CLOTH S.W.T.&S.Co.N.Y. | ||