The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 15, 1983
Filed:
Oct. 10, 1980
Donald W Fowler, West Haven, CT (US);
Kenneth C Arifian, Monroe, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
The foldable rotor blades (12) of a helicopter are automatically adjusted to pitch angles where they can be locked as a prerequisite to folding, by commands generated (98, 112) to cause trim actuators (39-41) to drive swash plate servos (17-19) to the correct positions, initially (98) in response to stored trim references (120) and eventually (112) in response to the difference (109) between stored swash plate servo positions (120) and current servo positions (20-22). A claimed embodiment uses values of servo positions (20-22), just before unlocking the blades upon re-spreading them, to store, in nonvolatile memory (138), deviations (131) from nominal positions stored in read only memory, and generates (159) trim references in a subsequent folding operation in response to integrated values (166) to reduce actual position errors (162) toward zero from desired positions indicated by the stored deviations (148).