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:
Nov. 10, 2020
Filed:
Nov. 09, 2017
Bell Helicopter Textron Inc., Fort Worth, TX (US);
Eric R. Gonzalez, Fort Worth, TX (US);
Frank B. Stamps, Colleyville, TX (US);
Bell Helicopter Textron Inc., Fort Worth, TX (US);
Abstract
A multirotor aircraft comprises at least three proprotors. Each proprotor has a plurality of rotor blades pivotably attached to a mast assembly. When a rotor blade pitch angle is changed for a proprotor, all rotor blades on the proprotor change to a same pitch angle. The proprotors are configured to spin freely when a power source is disengaged or fails. In various embodiments, one or more engines provides power to each proprotor, or at least one engine provides power to two or more proprotors. A rotor blade control system is configured to control a collective rotor blade pitch angle on each proprotor independently of the rotor blade pitch on the other proprotors. The rotor blade control system is configured to set a negative collective rotor blade pitch angle on an unpowered proprotor, such as in response to manual inputs by a pilot or in response to current engine conditions.