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).
List of two patent applications for controllable and variable pitch propellers.
| Identifier | ExFiles\Box 147\1\ scan0261 | |
| Date | 24th August 1937 guessed | |
| No. Name of Patentee. Title. 21532 United Aircraft Corporation Controllable pitch propellers 21116 Vereinigte Deutsche Metall- Gear for varying the pitch of the blades of variable pitch screws. werke A.G. ---------------- It should be noted that it is not possible to obtain further information regarding the above until unless the applications are completed and published. | ||