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:
Jun. 08, 1982
Filed:
Aug. 29, 1979
Jan M Drees, Dallas County, TX (US);
Larry W Dooley, Tarrant County, TX (US);
William D Neathery, Tarrant County, TX (US);
Textron, Inc., Providence, RI (US);
Abstract
A system for opposing helicopter blade flapping applies restraining forces at a low spring rate at low flap angles and at a high spring rate at flap angles greater than a predetermined angle. More particularly, bearings rotatably support the blade yoke on rotor hub trunnions which form a flapping axis. A resilient mechanical coupling between the blade yokes and the hub trunnion applies a restraining force having a characteristic linear with flapping angle. A second restraint mounted to rotate about the flapping axis with the rotor, applies a nonlinear restraining force which preferably rapidly increases beginning at a predetermined flap angle, and over the range short of hard flapping contact between the rotor and the rotor mast.