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).
Benefits of a parallel spindle over a tapered spindle in the Autovac system.
| Identifier | ExFiles\Box 40\4\ Scan183 | |
| Date | 13th October 1926 guessed | |
| (2) ..its guide, which wear will decrease the restriction and produce the same effect, after wear, in the case of the parallel spindle, as is attained by a tapered spindle when new. Also when the Autovac is open to the induction pipe depression, the piston valve moves outwards due to the local reduction in depression caused by the flow of air from the Autovac to the induction pipe, and in moving outwards decreases the restriction in the case of the tapered spindle, whereas the restriction remains constant with a parallel spindle until the spindle is clear of its guide. By using a parallel spindle we shall be slightly better off than by using the unit as supplied to us by the Autovac Co; it is recommended therefore that the piston spindle be made parallel throughout its length instead of being tapered off slightly at the end. F.{Mr Friese} Hickey | ||