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).
Design considerations and comparisons for various mechanical components.
| Identifier | ExFiles\Box 27\1\ Scan051 | |
| Date | 2nd January 1929 guessed | |
| contd :- -22- SPRING. It is very desirable to have a constant pressure maintained down the stroke, and to do this Bijur's have employed a spring of large free length, this is badly overstressed according to W = f π d³ / 16r , but they argue that it is so rarely used that no detriment accrues from using loads in excess of its safe maximum load. Can we do this? Their ratio of compression at the top of the stroke to that in position is as follows :- P1 228 -- = --- = 1.22 P2 190 ours is P1 101.5 -- = ----- = 1.54 (N.sch.2736) P2 66 Our pressure should not be less than 100 lbs/sq. in. as theirs is 124 lbs/sq. in. At present ours will not maintain above 57 lbs/sq. in. AIR VENT. There is no provision for an air vent on N.sch.2647. This is essential. Filler cap. The filler cap is inadequate. PISTON. By slotting the piston as shewn in the accompanying sketch, and reducing the width of passage the oil has to go through we find the time lag due to viscosity is reduced. LOCK RING TO CORK. The fitters say this is not necessary as the cork swells, and fills up the undercut. contd :- | ||