ALEXANDRIA, Va., Feb. 17 -- United States Patent no. 12,553,391, issued on Feb. 17, was assigned to ROLLS-ROYCE plc (London).
"Geared gas turbine engine" was invented by Nicholas Howarth (Derby, Great Britain) and Gareth M Armstrong (Derby, Great Britain).
According to the abstract* released by the U.S. Patent & Trademark Office: "A gas turbine engine has a compression system blade ratio defined as the ratio of the height of a fan blade to the height of the most downstream compressor blade in the range of from 45 to 95. This results in an optimum balance between installation benefits, operability, maintenance requirements and engine efficiency when the gas turbine engine is installed on an aircraft."
The patent was filed on Aug. 27, 2025...