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).
Blueprint showing the contour of a Woodhead special spring main leaf under torsion and load.
| Identifier | ExFiles\Box 42\3\ Scan201 | |
| Date | 10th August 1926 guessed | |
| SPRING CONTOUR UNDER TORSION SHACKLE ANGLE BEFORE TORSION 21° AFTER 18.5° WITH 1100 LBS LOAD WITH TORQUE GIVING 6° LEAN T SHOWING THE SHAPE ASSUMED BY A WOODHEAD SPECIAL SPRING MAIN LEAF UNDER THE ACTION OF A 1100 LB LOAD, & A TORQUE APPLIED AS SHOWN THE VERTICAL & HORIZONTAL SCALES ARE NOT EQUAL VERTICAL SCALE 1" = 1" HORIZONTAL SCALE 1" = 10" | ||