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).
Page of calculations and formulas concerning spring stresses and design for minimum stress.
| Identifier | ExFiles\Box 52\1\ Scan178 | |
| Date | 29th January 1929 guessed | |
| -2- Contd. Comparative stresses in two springs are as C. d. {John DeLooze - Company Secretary} δ. : C₂ d₂ δ ₂ ------ ------ D. {John DeLooze - Company Secretary} ² n. D₂² n₂ W D π --- = --- d³ f 2 16 π C d δ = --- d³ x ------- 16 π D²n 8 D³nW {N. Walker - Patents} δ = -------- C d⁴ C d⁴ δ W = -------- 8 D³n W C d⁴ Rate = --- = ------- δ 8 D³n Spring of given load, compressed length, rate and coil diameter for minimum stress. We have given W, L' = L - δ, R = W/δ and D. {John DeLooze - Company Secretary} Since f C d δ 8 D³n --- = ------ x ------- W πD²n Cd⁴ The stress f = 8 DW ------ πd³ so that d must be as large as possible. If n be the number of coils, the limit of (n+1)d is L' Contd. | ||