A steerable and retractable aircraft nose landing gear assembly including a cross link for rapidly connecting and disconnecting the nose wheels from the aircraft steering mechanism and a common locking arrangement for locking the wheels in retracted or extended positions is disclosed. The cross link arrangement connects a movable collar attached to the steering mechanism to a collar affixed to the wheels when the wheels are to be steered by the steering mechanism. Opening of the cross link separates the wheels from the steering mechanism and, thus, allows the aircraft to be freely moved by a towing vehicle without feedback to the steering mechanism occurring. The common locking mechanism comprises a bungee spring operated pair of off-center locking links running between the drag strut linkage and a flange affixed to the aircraft. The operation of an actuator rotates the links against the force created by the bungee spring to unlock the mechanism. When in either the extended or the retracted position, the off-center locking links prevent movement of the drag strut linkage in a manner such that the wheels are prevented from moving to the opposite position.

Steerable and retractable aircraft nose landing gear assembly

A hydraulic control cylinder (64) is used to swing the upper part (14) of a two part wheel strut (14, 16) about an axis of rotation (18) established at the upper end of the upper strut part (14) and at an upper central location within a stowage compartment (10). A folding drag brace assembly (102) is connected between the strut (16) and a lower rear portion of the stowage compartment (10). During use of the control cylinder (64) for swinging the upper strut part (14) rearwardly and upwardly, the drag brace (102) folds automatically in the manner of a pantographic device, and functions to fold the lower strut part (16) up against the upper strut part (14) within the stowage compartment (10). A mechanism is provided for rotating the wheel assembly (30) W, relative to the lower strut part (16), for the purpose of properly positioning the wheel assembly (30) W for movement into the stowage compartment (10). The invention makes it possible to retract the landing gear assembly (12) into a stowage compartment (10) which is considerably shorter than the in use length of the landing gear strut (14, 16) without the need for a second "down lock" member.

Main Landing gear with variable length drag brace

The front bearing for a landing gear trunion is carried by a rear wing spar and the rear bearing is carried by a landing gear beam which is pivotly attached at its inner end to the body frame. A main attach pin pivotally connects the outer end of such beam to a pair of connector plates, one located on each side of the connection. A pair of shear pins connect the connector plates to a short cantilever beam which is connected to and projects inwardly from the rear wing spar, generally in line with the landing gear beam. One of the shear pins is positioned generally horizontally outwardly from the main attach pin. The second shear pin is positioned generally vertically below the main attach pin. Generally vertical overloads are carried by the lower shear pin load and such shear pin is designed to fracture in response to a load slightly below the vertical load reacting capability of the reaction structure. Generally horizontal overloads are carried by the upper pin or by both pins together which are sized to break under loads slightly below the horizontal load reacting capability of the reaction structure.

Fused connection adapted to fail under different overloads acting in different directions

A three wheeled, generally in line, articulated landing gear with the lever trailing the lever hinge axis, applied in a pair Each shock strut, axle, and rolling assembly counter twist 90° upon retraction about a laterally offset post to present the smallest frontal area or pod size The twisting mechanism, the door links and the over center down lock are all tied mechanically to the gear so that no other sequencing is required during gear retraction or extension

Frederick V Lindquist

Papers

Retractable landing gear