US 7,744,349 B1 · Blade flap locking for out-of-use helicopters

Abstract

In the absence of centrifugal force produced during rotation of helicopter blades, damage may result if a blade is rotated upward by wind or other forces. Lock units removably appended between the rotor assembly and each blade pitch housing attached to a helicopter blade are usable to restrict upward rotation. A base portion of a lock unit may be configured to be held in position by a removable pin device. An extendible device extending from the base portion to a surface of a blade pitch housing can be adjusted to press the base portion back against a surface of the rotor assembly. The lock unit thereby restricts these surfaces of the blade pitch housing and rotor assembly from moving closer to each other and thereby restricts upward rotation of the blade pitch housing and its attached helicopter blade. The lock units are readily removable in preparation for returning a helicopter to active use.

Claims20

Dependent claims

A lock unit usable to restrict upward rotation of a blade pitch housing attached between a rotor assembly and a helicopter blade;

comprising:
a base portion having, on a first side, a contact surface to contact said rotor assembly and, on a second side opposed to said first side, a first opening, the base portion configured to enable the lock unit to be removably appended to said rotor assembly;
and
an insertion pin device insertable through a second opening in said base portion and into an opening in said rotor assembly to removably append the lock unit to the rotor assembly;
and
an extendible device positioned in said first opening and extendible to an extended position to contact said blade pitch housing, the extendible device including
a threaded shaft having a near end inserted into said first opening and a far end;
a first nut device rotatable on said threaded shaft to adjustably extend the threaded shaft out of said first opening;
an end piece extending beyond said far end of the threaded shaft and adjustable for alignment with a surface of said blade pitch housing, said end piece coupled to the far end of said threaded shaft and adjustable via a ball and socket configuration;
and
a second nut device rotatable on said threaded shaft to releasably secure an adjustment of the end piece.

8 more elements

Dependencies are inferred from the claim text.

Blade flap locking for out-of-use helicopters

Life of this patent

Blade flap locking for out-of-use helicopters

Life of this patent

Abstract

Claims20