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).
Calculation sheet for a long low rate spring, designated Z.
| Identifier | ExFiles\Box 52\1\ Scan187 | |
| Date | 31th January 1929 guessed | |
| -1- LONG LOW RATE SPRING Z. Maximum load = 8.25 lbw. Initial load = 6.00 lbw. Working compression = .700 inches. Rate = (2.25 / .700) = 3.21 lbw/inch (R) Compressed length = 4.000" (L') Initial length = 4.700" Free length = 6.570" (L) δ = 2.570" Suppose D = .275 + .048 = .323" Then d = ⁵√((8 x (.323)³ x 3.21 x 4000) / (12 x 10⁶)) = 1/10 ⁵√((8 x (.323)³ x 3.21) / 3) = 1/10 ⁵√.0285 = .049 n = (12 x 10⁶ x (.048)⁴) / (8 x (.323)³ x 3.21) = 73.8 say 74 f = (12 x 10⁶ x .048 x 2.570) / (π x (.323)² x 74) = 60800 lbs/sq.in. (n+d)d = 3.600" ___ EFC. {E. Fowler Clarke - Electrical Engineer} | ||