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).
The formulae and variables for spiral springs.
| Identifier | ExFiles\Box 52\1\ Scan177 | |
| Date | 29th January 1929 | |
| X4490 29.1.29. SPIRAL SPRINGS. No. of coils = n Dia. of wire = d (") " " coil = D (") Load = W (lbs) Modulus = C (lbs/sq.") T.M. = T (lb-inches) Length = l (inches) Deflection = δ (inches) lθ = d {John DeLooze - Company Secretary} /2 θ and ø = f {Mr Friese} /C θ = 2lf / dC and l = πDn θ = 2f / dC πDn δ = D {John DeLooze - Company Secretary} /2 θ = πD² n f / d C f = C d δ / πD² n Contd. | ||