The Boeing Company

Frank M Yourkowski

Mitchell Mellor

Melvin C Zoerb

The invention relates to mechanisms for reducing heat generation in a pivot joint, and to methods for their use. The mechanism may be designed to average relative velocities of a pin with respect to velocities of first and second members joined by the pin. The mechanism may comprise at least one linked member adapted to rotate the pin simultaneously with respect to both the first and second members. In such manner, the heat generated in the joint may be reduced, thereby decreasing the likelihood of failure of one or more of the joint's parts.

Mechanism for reducing heat generation in a joint

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.

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Renton, WA, United States of America

Frank M Yourkowski