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).
Specification for Patent No. 525879, related to a piston protuberance.
| Identifier | ExFiles\Box 147\4\ scan0147 | |
| Date | 26th March 1941 | |
| Fm. Patent Speci; file Protuberance of Piston - Patent No.525879 Referring to your recent verbal enquiry, we send herewith a copy of the above specification. The patent is in force and will not become due for renewal until the end of next year. You will notice our main claim number 1 is somewhat narrow. We were forced into this by citations raised by the British Patent Office which were chiefly concerned with Diesel engines. We also send a copy of Patent 505895 which is referred to in 525879. N.W. [Signature] | ||