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. 04, 1986
Filed:
Aug. 01, 1983
Frank M Yourkowski, Enumclaw, WA (US);
Melvin C Zoerb, Renton, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
In an aircraft having an alternate gear extension system as a backup for use by the pilot in the event of failure of the main gear extension system, a ground-crew operated subsystem is integrated with the pilot's alternate gear extension equipment for enabling the ground-crew to open and close the gear door by controls accessible on the underside of the aircraft fuselage. The integration of these two functions involves dual use of certain of the electrical and hydraulic components so that frequent and scheduled operation of the door opening function by ground-crew personnel automatically exercises the alternate gear extension mode to ensure its operability as a safety backup to the main gear extension system. The added components of the ground-crew door control function include a safety valve and an associated safety valve latch that prevent subsequent and unexpected door closure under conditions in which hydraulic actuator pressure is not available at the instant a door is commanded closed, but becomes available at a subsequent time.