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).
Description and performance review of an automatic variable-pitch propeller.
| Identifier | ExFiles\Box 173\3\ img006 | |
| Date | 10th March 1934 | |
| HS.{Lord Ernest Hives - Chair} - page 2 - March 10,1934 VARIABLE PITCH PROPELLOR This is entirely automatic. The whole propellor hub is free to float one or two inches endwise except for the restraint imposed by a number of helical springs which keep it in the rear most position when at rest, i.e., no thrust. This is the position of minimum pitch. As the thrust increases the hub moves bodily forward against the springs, so altering the blade angle by means of a toggle action. We had a flight behind this propellor on a 250-H.P. engine. It allowed maximum revolutions for take-off and appeared to work satisfactorily in flight. Its big advantage is that it is a complete unit that can be fitted in the place of any propellor and requires no manual control at all. It is alleged to out-perform the two position Hamilton. It has a big advantage over the "Smith" propellor in that it will take the standard duralumin blade. It does not appear that it will be any lighter than the "Hamilton". It can be fitted with a device to limit the maximum engine revolutions in a dive. This would appear to be a very considerable asset. It is possible that it will be demonstrated in Europe later on in the year. | ||