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).
Revised calculations for bellows for use with a bonnet louvre scheme suggested by the British Thermostat Co.
| Identifier | ExFiles\Box 156\1\ scan0129 | |
| Date | 19th November 1935 | |
| Hs {Lord Ernest Hives - Chair} /Std.2/KW.19.11.35. Revised Calculations for Bellows for use with Bonnet Louvre Scheme suggested by British Thermostat Co. Required travel of rod operating shutters - 0.50" " force on " - 10 lbs. Selected travel of bellows - .125" ∴ Force acting at bellows plate must be 10 x .5 / .125 = 40 lbs. Use Bellows 5" O {Mr Oldham} /D and 4.9/32" inside dia. - (No.21.B). Mean area = 17.4 sq.in. Rate = 12 lbs/⅛" - as given on drawing sent to us. Either charge - temp. 35/45°C. Vapour pressures - 0 to 6 lbs/sq.in. Spring - initial load - 52 lbs. Rate - 99.2 lbs/in. Assume bellows to be in free position when hot. When cold, pull developed at bellows plate = ↓ Spring - (V.P. x M.A.) - Bellows load = 52 - 0 - 12 = 40 lbs. When hot, push developed at bellows plate = (V.P. x M.A.) - spring + bellows load = 6 x 17.4 - (52 + 12.4) + 0 = 104.4 - 64.4 + 0 = 40 lbs. giving required forces at shutter operating rod of 10 lbs. pull and 10 lbs. push. | ||