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).
Experiment on gear noise reduction using different types of teeth.
| Identifier | ExFiles\Box 64\4\ scan0025 | |
| Date | 12th December 1927 guessed | |
| -3- Contd. use of parallel teeth, the other set to be helical with the present helix but to have more suitably cut teeth as an experiment on the reduction of gear noise with the present arrangement. EFC. | ||