Patent Description:
Shock absorbing devices are used in a wide variety of vehicle suspension systems for controlling motion of the vehicle and its tires with respect to the ground and for reducing transmission of transient forces from the ground to the vehicle. Shock absorbing struts are a common component in most aircraft landing gear assemblies. Shock struts control motion of the landing gear, and absorb and damp loads imposed on the gear during landing, taxiing, braking, and takeoff.

A shock strut generally accomplishes these functions by compressing a fluid within a sealed chamber formed by hollow telescoping cylinders. The fluid generally includes both a gas and a liquid, such as hydraulic fluid or oil. One type of shock strut generally utilizes an "air-over-oil" arrangement wherein a trapped volume of gas is compressed as the shock strut is axially compressed, and a volume of oil is metered through an orifice. The gas acts as an energy storage device, similar to a spring, so that upon termination of a compressing force the shock strut returns to its original length. Shock struts also dissipate energy by passing the oil through the orifice so that as the shock absorber is compressed or extended, its rate of motion is limited by the damping action from the interaction of the orifice and the oil.

<CIT> and <CIT> respectively disclose damping assemblies comprising a rotatable metering pin.

A shock strut assembly is provided as defined in claim <NUM>.

In various embodiments, the first damping actor configuration may include a first damping curve, the second damping actor configuration may include a second damping curve, and the first damping curve and the second damping curve may be different. The first damping curve may be for conventional landing of an aircraft. The second damping curve may be for a catapult launch of the aircraft.

In various embodiments, the damping actor selector may comprise a hydraulic actuation or pneumatic actuation. The damping actor selector may comprise at least one of an electric stepper or a servo motor. The first damping actor configuration may include a first damping curve, the second damping actor configuration may include a second damping curve, and the first damping curve may be different than the second damping curve.

The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein without departing from the spirit and scope of the disclosure.

A multi-actor damping system is disclosed. The multi-actor damping system may be used in a shock strut assembly to alter a damping curve of the shuck strut assembly. A "damping curve," as disclosed herein is the relationship between shock strut damping and stroke. A multi-actor damping system, as disclosed herein, may be configured to alter a damping curve by clocking a metering pin and/or main orifice plate to various positions. In various embodiments, a metering pin of a shock strut assembly may comprise a damping profile. A "damping profile," as disclosed herein, is a varying cross sectional area of the metering pin over its length to establish a respective damping curve associated with the metering pin.

In various embodiments, a shock strut assembly may include a plurality of damping actor configurations. A "damping actor configuration," as disclosed herein, is any configuration of the shuck strut assembly that produces a unique damping curve. A main orifice assembly of the shock strut assembly may be configured to produce any number of damping actor configurations. The main orifice assembly may be configured to add or subtract flow are from the damping profile in response to altering a position of the main orifice assembly and/or the metering pin. The shuck strut assembly may include various actor angles corresponding to a respective damping actor configuration. An "actor angle," as disclosed herein, is a relative clock angle between the metering pin and a strut cylinder. The actor angle determines which damping actor configuration is active.

The multi-actor damping system uses the actor angle to add or subtract flow area from the damping profile of the metering pin and/or alter a discharge coefficient. The system may allow selection of various pre-defined damping actor configurations. The strut performance may be enhanced by allowing selection of a damping profile based on a given activity of an aircraft (e.g., a landing damping actor, a catapult damping actor, a taxi damping actor, a short takeoff and vertical landing (STOVL) damping actor, a percolation damping actor, or the like.

Referring now to <FIG>, a shock strut assembly <NUM> for use in a landing gear system, in accordance with various embodiments, is illustrated. The shock strut assembly <NUM> may comprise a strut cylinder <NUM>, a strut piston <NUM>, a metering pin <NUM>, an orifice support tube <NUM>, and a main orifice assembly <NUM>. Strut piston <NUM> may be operatively coupled to strut cylinder <NUM> as described herein. Strut cylinder <NUM> may be configured to receive strut piston <NUM> in a manner that allows the two components to telescope together and absorb and/or dampen forces transmitted thereto. In various embodiments, a liquid, such as a hydraulic fluid and/or oil may be located within strut cylinder <NUM>. A gas, such as nitrogen or air, may also be located within strut cylinder <NUM>. Strut cylinder <NUM> and strut piston <NUM> may, for example, be configured to seal such that fluid contained within strut cylinder <NUM> is prevented from leaking as strut piston <NUM> translates relative to strut cylinder <NUM>.

Shock strut assembly <NUM> may comprise a low pressure, primary chamber <NUM> in which oil and gas can mix. In this regard, a volume of gas (also referred to herein as a primary chamber gas volume) <NUM> and a volume of oil (also referred to herein as an oil volume) <NUM> may be contained within primary chamber <NUM>. A portion of primary chamber <NUM> may contain the primary chamber gas volume <NUM> and may be referred to as a primary gas chamber <NUM>. Similarly, the portion of primary chamber <NUM> containing the oil volume <NUM> may be referred to herein as an oil chamber <NUM>. Dashed line <NUM> represents the level of oil volume <NUM>, or the interface between the oil chamber <NUM> and the primary gas chamber <NUM>. Stated differently, the oil volume <NUM> may be located below dashed line <NUM> and primary chamber gas volume <NUM> may be located above dashed line <NUM>. In this regard, the interface between the oil chamber <NUM> and the primary gas chamber <NUM> may move relative to primary chamber <NUM> depending on the position of strut piston <NUM> relative to strut cylinder <NUM>.

The metering pin <NUM> and the orifice support tube <NUM> may be positioned within primary chamber <NUM>. The metering pin <NUM> may translate with strut piston <NUM> with respect to main orifice assembly <NUM>. In various embodiments, the metering pin <NUM> may be configured to rotate about a centerline of the metering pin <NUM>. In various embodiments, the orifice support tube <NUM> may be configured to rotate about a centerline of the orifice support tube <NUM>. By rotating the metering pin <NUM> or the orifice support tube <NUM>, the shock strut assembly <NUM> may change from a first damping actor configuration to a second damping actor configuration.

In various embodiments, the shock strut assembly <NUM> further comprises a damping actor selector <NUM>. The damping actor selector <NUM> is configured to rotate metering pin <NUM> relative to the strut piston <NUM>. In various embodiments, the damping actor selector <NUM> may be coupled to the orifice support tube <NUM> and configured to rotate the orifice support tube <NUM> relative to the metering pin <NUM>. The damping actor selector <NUM> may provide position control by direct drive, transmitted through a linkage, or any other method of position control known in the art. For example, the damping actor selector <NUM> may comprise hydraulic or pneumatic actuation. In this regard, pressure may be used to drive a piston head of the damping actor selector <NUM> linearly along the centerline of metering pin <NUM>. As the piston moves, it may cause the metering pin <NUM> to rotate due to a screw thread interface between the metering pin <NUM> and the piston of the damping actor selector <NUM>.

In various embodiments, external supply pressure may be applied by oil volume <NUM> in oil chamber <NUM> and automatically return the damping actor selector to a neutral or default damping actor configuration. The pressure may be configured to translate the piston of the damping actor selector along the centerline of the metering pin <NUM> to change damping actor configurations. This configuration may provide an inherent safety feature of providing its own power source to return the damping actor selector <NUM> to a default damping actor configuration.

In various embodiments, the damping actor selector <NUM> may comprise an electric stepper, servo motor, or the like. A stepper motor may provide accurate angular positioning with an open loop design. A servo motor may produce accurate position and/or may provide a closed loop system. The damping actor selector <NUM> may interface with an aircraft control system. The aircraft control system may be configured to control damping actor selector <NUM> and/or alter the shock strut assembly from a first damping actor configuration to as second damping actor configuration.

Referring now to <FIG>, detail A of shock strut assembly <NUM> from <FIG>, in accordance with various embodiments, is illustrated. In various embodiments, main orifice assembly <NUM> further comprises a main orifice plate <NUM>. Main orifice plate <NUM> may be disposed in a recess of orifice support tube <NUM>. Main orifice plate is coupled to first flow restrictor <NUM> and/or second flow restrictor <NUM>. The first flow restrictor <NUM> and the second flow restrictor <NUM> may each comprise an aperture <NUM> extending through the flow restrictor and defining a fulcrum about which first flow restrictor <NUM> and second flow restrictor <NUM> pivot. Main orifice plate <NUM> may be configured to rotate with the metering pin <NUM>. For example, when metering pin <NUM> is rotated, it transitions torque to the main orifice plate <NUM> via interface <NUM> between an aperture in main orifice plate <NUM> and a side of metering pin <NUM>. In various embodiments, main orifice plate <NUM> may be configured to rotate with orifice support tube <NUM> relative to metering pin <NUM>.

In various embodiments, the main orifice assembly <NUM> further comprises a first orbit cam <NUM> and a second orbit cam <NUM>. First orbit cam <NUM> and second orbit cam <NUM> may be configured to remain stationary as metering pin <NUM> and main orifice plate <NUM> rotate. Each orbit cam is configured to guide a respective flow restrictor from a first damping actor configuration to a second damping actor configuration. For example, as main orifice plate <NUM> rotates about the centerline of metering pin <NUM>, a head portion of a respective flow restrictor is guided in a respective orbit cam. For example, head portion <NUM> of first flow restrictor <NUM> may be guided in a respective track or groove of second orbit cam <NUM>. The track or groove of second orbit cam <NUM> may be configured to cause first flow restrictor <NUM> to pivot about the fulcrum either towards the metering pin <NUM> or away from the metering pin <NUM>.

Referring now to <FIG>, an exploded view of a main orifice assembly <NUM>, in accordance with various embodiments, is illustrated. In various embodiments, main orifice assembly <NUM> further comprises a main orifice plate mount <NUM> and a main orifice plate retainer <NUM>. The main orifice plate mount <NUM> may be configured to allow the main orifice plate <NUM> to be restrained axially and/or also allow the main orifice plate to rotate freely about the centerline of metering pin <NUM>. In various embodiments, the main orifice plate retainer <NUM> is configured to retain the main orifice plate mount <NUM> axially. For example, main orifice plate retainer <NUM> may couple to the main orifice plate mount <NUM> and hold the main orifice plate mount <NUM> in place.

In various embodiments, the main orifice assembly <NUM> further comprises a first spring <NUM> and a second spring <NUM>. Each spring may be coupled to a respective flow restrictor. For example, first spring <NUM> is coupled to first flow restrictor <NUM> and second spring <NUM> is coupled to second flow restrictor <NUM>. Each spring may be configured to load a respective flow restrictor against metering pin <NUM> in a respective damping actor configuration. Each spring may comprise a torsion spring, or the like. For example, first spring <NUM> may be configured to apply a torque to first flow restrictor <NUM> about the fulcrum defined by aperture <NUM> of the first flow restrictor <NUM> in a first damping actor configuration. In doing so, a damping curve of the shock strut assembly <NUM> may be altered.

In various embodiments, the main orifice plate <NUM> may further comprise a plate portion <NUM> and a plurality of lugs <NUM>. The plurality of lugs <NUM> may extend axially from a surface of plate portion <NUM>. Each flow restrictor may couple to a first lug and a second lug from the plurality of lugs. For example, first flow restrictor <NUM> may be coupled to first lug <NUM> and second lug <NUM> form the plurality of lugs <NUM>.

Referring now to <FIG>, a cross-section of main orifice assembly <NUM> in a first damping actor configuration, in accordance with various embodiments, is illustrated. In the first damping actor configuration, first flow restrictor <NUM> and second flow restrictor <NUM> may be fully retracted. "Fully retracted," as disclosed herein, occurs when each flow restrictor is not in contact with metering pin <NUM>. While fully retracted, the first flow restrictor <NUM> and the second flow restrictor <NUM> have little to no effect on the damping curve. In various embodiments, when the first flow restrictor <NUM> and the second flow restrictor <NUM> are retracted, the damping curve is based on a damping curve associated with a profile of the metering pin <NUM>.

Referring now to <FIG>, a cross-section of main orifice assembly <NUM> in a second damping actor configuration, in accordance with various embodiments, is illustrated. In the second damping actor configuration, first flow restrictor <NUM> and second flow restrictor <NUM> may be fully deployed. "Fully deployed," as disclosed herein, occurs when each flow restrictor is in contact with metering pin <NUM>. While fully deployed, the first flow restrictor <NUM> and the second flow restrictor <NUM> effect the damping curve and/or provide enhanced damping relative to the first damping actor configuration. In various embodiments, when the first flow restrictor <NUM> and the second flow restrictor <NUM> are deployed, the damping curve is based on a damping curve associated with the profile of the metering pin <NUM> as well as a profile of the first flow restrictor <NUM> and the second flow restrictor <NUM>.

Referring now to <FIG>, various views of a flow restrictor <NUM>, in accordance with various embodiments, is illustrated. First flow restrictor <NUM> and second flow restrictor <NUM> may be in accordance with flow restrictor <NUM>. The flow restrictor <NUM> comprises a head portion <NUM> and a restrictor portion <NUM>.

Head portion <NUM> comprises a first mating surface <NUM> and a second mating surface <NUM>. First mating surface <NUM> may be disposed opposite second mating surface <NUM>. First mating surface <NUM> may be configured to mate to a lug in the plurality of lugs <NUM> of main orifice plate <NUM> (as shown in <FIG>). Similarly, second mating surface <NUM> may be configured to mate to a lug in the plurality of lugs <NUM> of main orifice plate <NUM>. Head portion <NUM> may further comprise an aperture <NUM> extending through head portion <NUM> from first mating surface <NUM> to second mating surface <NUM>. In various embodiments, the aperture <NUM> may act as a fulcrum for the flow restrictor <NUM>. Head portion may further comprise a protrusion <NUM> extending from an outer surface <NUM> of head portion <NUM>. The protrusion <NUM> may be configured to rotate the flow restrictor <NUM>. For example, protrusion <NUM> may contact a respective orbit cam (e.g., first orbit cam <NUM> for first flow restrictor <NUM>) and/or protrusion <NUM> may be guided by a track on an inner surface of a respective orbit during deploying and/or retracting flow restrictor <NUM>.

In various embodiments, restrictor portion <NUM> may comprise a spine <NUM> extending from head portion <NUM> to a tail end <NUM> of the flow restrictor <NUM>. In various embodiments, the spine <NUM> may define an arc or the like. The spine <NUM> may be disposed between a first convex surface <NUM> and a second convex surface <NUM>. The spine <NUM>, the first convex surface <NUM>, and the second convex surface <NUM> may be configured to interface with a flute and/or groove disposed in metering pin <NUM> (from <FIG>) when the flow restrictor <NUM> is in a deployed position. In various embodiments, the spine <NUM>, the first convex surface <NUM> and the second convex surface <NUM> may define an outer surface of restrictor portion <NUM>.

In various embodiments, restrictor portion <NUM> may comprise a concave surface <NUM> disposed opposite the first convex surface <NUM> and the second convex surface <NUM>. The concave surface <NUM> may include a first recess <NUM> disposed therein. The first recess <NUM> may be configured to receive a spring. The first recess <NUM> may be disposed on a portion of the concave surface <NUM> and a portion of head portion <NUM>.

In various embodiments, head portion <NUM> may further comprise a second recess <NUM>. Second recess <NUM> and first recess <NUM> may partially define a channel. The channel may be configured to receive a spring, in accordance with various embodiments.

Referring now to <FIG>, an orbit cam <NUM>, in accordance with various embodiments, is illustrated. In various embodiments, orbit cam <NUM> is semi-annular. The orbit cam may comprise a first mating surface <NUM> and a second mating surface <NUM>. First mating surface <NUM> may include a male fastener <NUM>. Second mating surface <NUM> may include a female fastener <NUM>. In various embodiments, the first mating surface <NUM> and second mating surface <NUM> may both contain male fasteners or the first mating surface <NUM> and second mating surface <NUM> may both contain female fasteners. By having a male fastener on one mating surface and a female mating fastener on a second mating surface, a first orbit cam may be coupled to a second orbit cam and both the first orbit cam and the second orbit cam may have the same geometry. For example, first orbit cam <NUM> and second orbit cam <NUM> may both be in accordance with orbit cam <NUM>.

Orbit cam <NUM> may further comprise a guide ramp <NUM> disposed on a radially inner surface <NUM> of orbit cam <NUM>. Guide ramp <NUM> may extend radially inward from the radially inner surface <NUM> from a first axially end and extend axially and circumferentially about radially inner surface <NUM>. With combined reference to <FIG> and <FIG>, guide ramp <NUM> may be configured to guide the protrusion <NUM> of a head portion <NUM> of a flow restrictor <NUM>. For example, guide ramp <NUM> may alter an axial position of protrusion <NUM> and either retract or deploy flow restrictor <NUM>.

Orbit cam <NUM> may further comprise an anti-rotation feature <NUM>. The anti-rotation feature <NUM> may be disposed on a radially outer surface <NUM> of the orbit cam <NUM>. The anti-rotation feature <NUM> may be a flat recess <NUM> disposed on the radially outer surface <NUM>. The anti-rotation feature <NUM> may be configured to interface with a corresponding anti-rotation feature on the main orifice plate mount <NUM> (as shown in <FIG>).

In various embodiments, orbit cam <NUM> comprises a proximal end <NUM> and a distal end <NUM> disposed distal in an axial direction from the proximal end <NUM>. Orbit cam <NUM> may comprise a groove <NUM> disposed proximate distal end <NUM>. The groove <NUM> may be configured to receive a tongue from a mating main orifice plate (e.g., main orifice plate <NUM>). As such, the main orifice plate may rotate while the orbit cam <NUM> may remain stationary.

Referring now to <FIG>, a metering pin <NUM>, in accordance with various embodiments. The metering pin <NUM> may comprise an elongated member <NUM> extending from a first end <NUM> to a second end <NUM> and defining a central axis. The elongated member <NUM> may include a quadrilateral cross-section. In various embodiments, the quadrilateral cross-section may comprise a trapezoidal cross-section, a square cross-section, or the like. In various embodiments, the first end <NUM> may comprise a quadrilateral cross section (e.g., a trapezoidal cross section, a square cross section, or the like). A square cross-section may provide enhances torque transfer properties. A trapezoidal cross-section may provide mistake proofing during assembly of a main orifice assembly. In various embodiments, with reference now to <FIG>, a cross-section along section line A-A of metering pin <NUM> is illustrated, in accordance with various embodiments.

With combined reference now to <FIG>, on a first side <NUM> of the quadrilateral cross section of the metering pin <NUM>, the metering pin <NUM> may comprise a first flute profile <NUM>. In various embodiments, first flute profile <NUM> may comprise a groove <NUM> disposed in the first side <NUM> of the quadrilateral cross section. In various embodiments, the groove may be a V-groove, a V-groove with a fillet, or the like. The first flute profile <NUM> may extend a length L1 of the metering pin <NUM>. The length L1 of the first flute profile <NUM> may correspond to a full stroke length of a strut stroke for a shock strut assembly (e.g., shock strut assembly <NUM> from <FIG>). In various embodiments, L1 may be between <NUM>% and <NUM>% of a length of metering pin <NUM>. In various embodiments, the first flute profile <NUM> may be disposed on a third side <NUM> of the quadrilateral cross section of the metering pin <NUM>. The third side <NUM> may be opposite the first side <NUM>. The third side <NUM> may comprise a groove <NUM> in accordance with groove <NUM>.

In various embodiments, on a second side <NUM> of the quadrilateral cross section of the metering pin <NUM>, the metering pin <NUM> may comprise a second flute profile <NUM>. The second side <NUM> may be adjacent to the first side <NUM> and the third side <NUM>. In various embodiments, second flute profile <NUM> may comprise a groove <NUM> disposed in the second side <NUM> of the quadrilateral cross section. In various embodiments, the groove may be a V-groove, a V-groove with a fillet, or the like. The second flute profile <NUM> may extend a length L2 of the metering pin <NUM>. The length L2 of the second flute profile <NUM> may correspond to approximately a half stroke length of a strut stroke for a shock strut assembly (e.g., shock strut assembly <NUM> from <FIG>). In various embodiments, L2 may be between <NUM>% and <NUM>% of a length of metering pin <NUM>. In various embodiments, the second flute profile <NUM> may be disposed on a fourth side <NUM> of the quadrilateral cross section of the metering pin <NUM>. The fourth side <NUM> may be opposite the second side. The fourth side <NUM> may comprise a groove <NUM> in accordance with groove <NUM>. In various embodiments, grooves <NUM>, <NUM>, <NUM>, <NUM> may all be the same.

In various embodiments, first flute profile <NUM> may be configured to be effective across a full stroke range. In various embodiments, second flute profile <NUM> may be configured to be effective from a fully extended stroke to approximately half of a stroke. The combination of first flute profile <NUM> and second flute profile <NUM> used in combination is greater damping as a function of stroke compared to utilizing only first flute profile <NUM> or only second flute profile <NUM>.

In various embodiments, with combined reference to <FIG> and <FIG>, grooves <NUM>, <NUM>, <NUM>, <NUM> may all be configured to interface with a restrictor portion <NUM> of flow restrictor <NUM> when a flow restrictor <NUM> is in a fully deployed position in a main orifice assembly. For example, a fillet portion <NUM> of groove <NUM> may be configured to interface with the spine <NUM> of restrictor portion <NUM> of flow restrictor <NUM>. Similarly, first convex surface <NUM> may be configured to interface with first wall <NUM> of groove <NUM> and the second convex surface <NUM> of the restrictor portion <NUM> of flow restrictor <NUM> may be configured to interface with second wall <NUM> of groove <NUM>.

Referring now to <FIG>, a portion of a shock strut assembly along a top view, in accordance with various embodiments, is illustrated. In various embodiments, the orifice support tube <NUM> may further comprise a coupling end <NUM> disposed axially adjacent to the main orifice plate <NUM>. Main orifice plate <NUM> may comprise an aperture <NUM>. Aperture <NUM> may correspond to a cross-sectional shape of metering pin <NUM> (e.g., a quadrilateral shape, or the like). The metering pin <NUM> may be disposed in aperture <NUM> and configured to transfer torque from the metering pin <NUM> to the main orifice plate <NUM> in order to clock a main orifice assembly (e.g., main orifice assembly <NUM> from <FIG>), in accordance with various embodiments. In various embodiments, the metering pin <NUM> may be in accordance with the metering pin <NUM> from <FIG>.

In various embodiments, coupling end <NUM> may comprise a clearance aperture <NUM>. Clearance aperture <NUM> may be configured to receive the metering pin <NUM> therethrough. Disposed radially outward from the clearance aperture <NUM>, the coupling end <NUM> may further comprise a first bypass alignment aperture <NUM>. In various embodiments, the coupling end <NUM> further comprises a second bypass alignment aperture <NUM> disposed approximately <NUM> degrees from the first bypass alignment aperture <NUM> on coupling end <NUM>. Any number of bypass alignment apertures located in any radial position on coupling end <NUM> is within the scope of this disclosure.

In various embodiments, main orifice plate <NUM> may further comprise a first bypass aperture <NUM> disposed radially outward from aperture <NUM>. In various embodiments, main orifice plate <NUM> may further comprise a second bypass aperture <NUM> disposed approximately <NUM> degrees from the first bypass aperture <NUM>. Any number of bypass apertures located in any radial position on main orifice plate <NUM> is within the scope of this disclosure. In various embodiments, the number of bypass alignment apertures on coupling end <NUM> corresponds to a number of bypass apertures on main orifice plate <NUM>. In various embodiments, the orientation of the bypass alignment apertures on coupling end <NUM> relative to each other may correspond to the orientation of the bypass apertures on main orifice plate <NUM>.

Referring now to <FIG> only, a bypass closed configuration of a shock strut assembly <NUM> from <FIG> is illustrated, in accordance with various embodiments. The bypass closed configuration may occur when first bypass aperture <NUM> of main orifice plate <NUM> is misaligned circumferentially with first bypass alignment aperture <NUM> of coupling end <NUM>. Similarly, the second bypass aperture <NUM> of main orifice plate <NUM> may be misaligned circumferentially with second bypass alignment aperture <NUM> when in the bypass closed configuration.

A multi-actor damping system could open and close bypass apertures <NUM>, <NUM> depending on the actor angle. After rotating the main orifice plate <NUM> as shown in <FIG>, the bypass apertures <NUM>, <NUM> may be aligned with bypass alignment apertures <NUM>, <NUM> of coupling end <NUM> and open the bypass apertures <NUM>, <NUM>, as shown in <FIG>. As such, <FIG> represents a bypass closed configuration of a shock strut assembly, in accordance with various embodiments. Utilizing bypass apertures in this manner may provide various damping actor configurations with or without the use of flow restrictors. In various embodiments, bypass apertures <NUM>, <NUM> may shift an entire damping curve higher or lower depending on whether they are in an open configuration or a closed configuration.

Controlling the bypass area may also be beneficial with regard to percolation, which occurs from a restriction of gas and oil flow across the main orifice plate <NUM> when the hydraulic chamber is refilling after a landing gear has been stored for flight and then extended for landing.

Referring now to <FIG>, the retraction of first flow restrictor <NUM> and second flow restrictor <NUM> over various actor angles is illustrated, in accordance with various embodiments. Referring now to <FIG> and <FIG>, cross-sections of a portion of a shock strut assembly having a first orientation (i.e., a first damping actor configuration corresponding to a first flow restrictor <NUM> and second flow restrictor <NUM> being deployed) is illustrated, in accordance with various embodiments. In the first damping actor configuration, the actor angle is approximately <NUM> degrees. In various embodiments, the actor angle is between -<NUM> degrees and <NUM> degrees in the first damping actor configuration.

In various embodiments, the restrictor portion <NUM> of first flow restrictor <NUM> and second flow restrictor <NUM> are each disposed in a groove (e.g., groove <NUM> of second flute profile <NUM> for first flow restrictor <NUM> and groove <NUM> of second flute profile <NUM> for second flow restrictor <NUM>). The restrictor portion <NUM> may at least partially contact a respective groove (e.g., restrictor portion <NUM> of first flow restrictor <NUM> may contact the groove <NUM> of second flute profile <NUM> and restrictor portion <NUM> of second flow restrictor <NUM> may contact the groove <NUM> of second flute profile <NUM>). A restrictor angle may be defined about a centerline of aperture <NUM>. For example, a <NUM> degree position may be defined by a vector (e.g., vector A) extending perpendicular from the centerline of aperture <NUM> of each flow restrictor (e.g., aperture <NUM> of first flow restrictor <NUM> and aperture <NUM> of second flow restrictor <NUM>) to a tail end <NUM> of each flow restrictor (e.g., tail end <NUM> of first flow restrictor <NUM> and tail end <NUM> of second flow restrictor <NUM>). In the first damping actor configuration, the flow restrictor angle for each flow restrictor may be <NUM> degrees by definition (i.e., the first damping configuration sets a first orientation about which the restrictor angle is measured from). In various embodiments, when the flow restrictor is fully deployed, the restrictor angle is <NUM> degrees by definition.

Referring now to <FIG> and <FIG>, cross-sections of a portion of a shock strut assembly having a first orientation (i.e., an actor angle between a first damping actor configuration (e.g., fully deploy flow restrictor) and a second damping actor configuration (e.g., a fully retracted flow restrictor)) is illustrated, in accordance with various embodiments. In the first orientation, the actor angle is approximately <NUM> degrees. In various embodiments, the actor angle is between <NUM> degrees and <NUM> degrees in the first orientation.

In various embodiments, the restrictor portion <NUM> of first flow restrictor <NUM> and second flow restrictor <NUM> each remain partially disposed in a groove (e.g., groove <NUM> of second flute profile <NUM> for first flow restrictor <NUM> and groove <NUM> of second flute profile <NUM> for second flow restrictor <NUM>). The restrictor portion <NUM> may at least partially contact a respective groove (e.g., restrictor portion <NUM> of first flow restrictor <NUM> may contact the groove <NUM> of second flute profile <NUM> and restrictor portion <NUM> of second flow restrictor <NUM> may contact the groove <NUM> of second flute profile <NUM>). In the first orientation, the restrictor angle for each flow restrictor may be approximately <NUM> degrees. In various embodiments, the flow restrictor angle is between <NUM> degrees and <NUM> degrees in the first orientation.

With brief reference to <FIG>, <FIG> and <FIG>, in the first orientation, a protrusion of a flow restrictor may be proximate a first end of guide ramp <NUM> (e.g., a protrusion <NUM> of first flow restrictor <NUM> may be proximate a first end of guide ramp <NUM> of a first orbit cam <NUM>. In various embodiments, main orifice plate <NUM> may further comprise a tongue <NUM> disposed at a proximal end of the main orifice plate <NUM> and extending in the radial direction. The tongue <NUM> may be received in the groove <NUM> of second orbit cam <NUM>. As metering pin <NUM> is further rotated about its center axis, the metering pin <NUM> applies a torque to main orifice plate <NUM>. The metering pin <NUM> may drive the rotation of the main orifice plate <NUM> while the second orbit cam <NUM> remains stationary. The respective protrusion may be guided by guide ramp <NUM> and begin to retract the respective flow restrictor (e.g., protrusion <NUM> of first flow restrictor <NUM> may be guided by guide ramp <NUM> of first orbit cam <NUM>).

Referring now to <FIG> and <FIG>, cross-sections of a portion of a shock strut assembly having a second orientation (i.e., an actor angle between the first orientation and a second damping actor configuration (e.g., a fully retracted flow restrictor)) is illustrated, in accordance with various embodiments. In the second orientation, the actor angle is approximately <NUM> degrees. In various embodiments, the actor angle is between <NUM> degrees and <NUM> degrees in the second orientation.

In various embodiments, the restrictor portion <NUM> of first flow restrictor and second flow restrictor <NUM> may be partially removed from the original groove from first damping actor configuration and first orientation (e.g., second flow restrictor <NUM> may be disposed outside of groove <NUM> for second flow restrictor <NUM> from <FIG>). In the second orientation, the restrictor angle for each flow restrictor may be approximately <NUM> degrees. In various embodiments, the restrictor angle may be between <NUM> degrees and <NUM> degrees in second orientation.

With brief reference to <FIG>, <FIG> and <FIG>, in the second orientation, a protrusion of a flow restrictor may be disposed a first axial distance from a proximal end <NUM> of a respective orbit cam on guide ramp <NUM> (e.g., a protrusion <NUM> of second flow restrictor <NUM> may be an axial distance from the proximal end <NUM> of second orbit cam <NUM> on guide ramp <NUM>). As the protrusion <NUM> of second flow restrictor <NUM> travels on the guide ramp <NUM>, the head portion <NUM> of second flow restrictor <NUM> pivots about the aperture <NUM> of second flow restrictor <NUM> and alters the flow restrictor angle as the second flow restrictor <NUM> begins to retract. As metering pin <NUM> is further rotated about its center axis, the respective protrusion may be guided by guide ramp <NUM> and begin to retract the respective flow restrictor (e.g., protrusion <NUM> of first flow restrictor <NUM> may be guided by guide ramp <NUM> of first orbit cam <NUM>).

Referring now to <FIG> and <FIG>, cross-sections of a portion of a shock strut assembly having a third orientation (i.e., an actor angle between the first and second orientation and a first and second damping actor configuration (e.g., a fully retracted flow restrictor)) is illustrated, in accordance with various embodiments. In the third orientation, the actor angle is approximately <NUM> degrees. In various embodiments, the actor angle is between <NUM> degrees and <NUM> degrees in the third orientation.

In various embodiments, the restrictor portion <NUM> of first flow restrictor and second flow restrictor <NUM> each remain proximate their respective grooves compared to first actor configuration, first orientation, and second orientation (e.g., groove <NUM> of second flute profile <NUM> for second flow restrictor <NUM>). The restrictor portion <NUM> may be spaced apart from the respective groove (e.g., restrictor portion <NUM> of second flow restrictor <NUM> may be spaced apart from groove <NUM> of second flute profile <NUM>). In the third orientation, the restrictor angle for each flow restrictor may be approximately <NUM> degrees. In various embodiments, the restrictor angle may be between <NUM> degrees and <NUM> degrees in the third orientation.

With brief reference to <FIG>, <FIG> and <FIG>, in the third orientation, a protrusion of a flow restrictor may be disposed a second axial distance from a proximal end <NUM> of a respective orbit cam on guide ramp <NUM> (e.g., a protrusion <NUM> of second flow restrictor <NUM> may be an axial distance from the proximal end <NUM> of second orbit cam <NUM> on guide ramp <NUM>). The second axial distance may be greater than the first axial distance in the second orientation. As the protrusion <NUM> of second flow restrictor <NUM> travels on the guide ramp <NUM>, the head portion <NUM> of second flow restrictor <NUM> pivots about the aperture <NUM> of second flow restrictor <NUM> and alters the flow restrictor angle as the second flow restrictor <NUM> continues to retract. As metering pin <NUM> is further rotated about its center axis, the protrusion <NUM> may be guided by guide ramp <NUM> and continue to retract the respective flow restrictor (e.g., protrusion <NUM> of first flow restrictor <NUM> may be guided by guide ramp <NUM> of first orbit cam <NUM>).

Referring now to <FIG> and 43B, cross-sections of a portion of a shock strut assembly having a second actor damping configuration (i.e., an orientation where with fully retracted flow restrictors) is illustrated, in accordance with various embodiments. In the second actor damping configuration, the actor angle is approximately <NUM> degrees. In various embodiments, the actor angle is between <NUM> degrees and <NUM> degrees in the second actor damping configuration. In the second damping actor configuration, the restrictor angle for each flow restrictor may be approximately <NUM> degrees. In various embodiments, the restrictor angle may be between <NUM> degrees and <NUM> degrees in the third orientation.

With brief reference to <FIG>, <FIG> and <FIG>, in the second damping actor configuration, a protrusion of a flow restrictor may be disposed a third axial distance from a proximal end <NUM> of a respective orbit cam on guide ramp <NUM> (e.g., a protrusion <NUM> of second flow restrictor <NUM> may be an axial distance from the proximal end <NUM> of second orbit cam <NUM> on guide ramp <NUM>). The third axial distance may be greater than the first axial distance in the second orientation and the second axial distance in the third orientation. As the protrusion <NUM> of second flow restrictor <NUM> travels on the guide ramp <NUM>, the head portion <NUM> of second flow restrictor <NUM> pivots about the aperture <NUM> of second flow restrictor <NUM> and alters the flow restrictor angle as the second flow restrictor <NUM> retracts entirely as it rotates from the third orientation to the second damping actor configuration. As metering pin <NUM> is further rotated about its center axis, the protrusion <NUM> may be guided by guide ramp <NUM> and retract the respective flow restrictor (e.g., protrusion <NUM> of first flow restrictor <NUM> may be guided by guide ramp <NUM> of first orbit cam <NUM>).

Referring now to <FIG>, a cross-section of a portion of a shock strut assembly having with the metering pin and the main orifice plate hidden is illustrated, in accordance with various embodiments. In various embodiments, guide ramp <NUM> of orbit cam <NUM> extends axially away from proximal end <NUM> as it travels circumferentially away from first mating surface <NUM> and towards second mating surface <NUM> until it reaches a maximum axial distance D1 from proximal end <NUM> before it starts to extend axially towards proximal end <NUM> as it continues extending circumferentially until it reaches second mating surface <NUM>.

Referring now to <FIG>, an exploded view of a portion of a main orifice assembly <NUM>, in accordance with various embodiments, is illustrated. In various embodiments, the orbit cams may have radial freedom along one line of motion while remaining clocked with the outer support tube. This may be accomplished by including four flat mating surfaces disposed approximately <NUM> degrees apart amongst multiple components. For example, flat recess <NUM> of first orbit cam <NUM> may interface with a first flat recess <NUM> disposed on a radially inner surface of main orifice plate retainer <NUM>. Similarly, flat recess <NUM> of second orbit cam <NUM> may interface with a second flat recess <NUM> disposed radially opposite the first flat recess <NUM>.

The main orifice plate retainer <NUM> may further comprise a first flat mating surface <NUM> disposed on a radially outer surface of main orifice plate retainer <NUM> and a second flat mating surface disposed opposite the first flat mating surface. Each flat mating surface of the main orifice plate retainer <NUM> may mate with a corresponding flat mating surface of the orifice support tube <NUM>. For example, the second flat mating surface may mate with a second flat mating surface <NUM> disposed on a radially inner surface of orifice support tube <NUM>. Similarly, first flat mating surface <NUM> may mate with a first flat mating surface disposed on a radially inner surface of orifice support tube <NUM>, the first flat mating surface disposed radially opposite the second flat mating surface <NUM>.

The flat mating surface allow the metering pin, the main orifice plate <NUM>, first orbit cam <NUM>, and second orbit cam <NUM> to translate together radially, while maintaining the first orbit cam <NUM> and the second orbit cam <NUM> aligned with the orifice support tube <NUM> in terms of actor angle. In various embodiments, the main orifice assembly <NUM> is configured to allow the first orbit cam <NUM> and the second orbit cam <NUM> to be disposed radially inward of the orifice plate mount <NUM> and slide relative to the main orifice plate mount in linear directions, while preventing rotation of the first orbit cam <NUM> and the second orbit cam <NUM>.

The main orifice assembly <NUM> may be configured to allow axial travel of the main orifice plate <NUM> during operation of a respective shock strut assembly. For example, main orifice plate mount <NUM> may mount the main orifice plate retainer <NUM>, first orbit cam <NUM>, second orbit cam <NUM>, and main orifice plate <NUM> within coupling end <NUM> of orifice support tube <NUM> loosely in the axially direction. As such, main orifice plate <NUM> may be configured to travel axially within the coupling end <NUM> and/or rotate about a centerline of a respective metering pin.

Referring now to <FIG>, a main orifice assembly <NUM> during operation of a shock strut assembly, in accordance with various embodiments, is illustrated. <FIG> illustrates oil flow during strut compression, and <FIG> illustrates oil flow during strut extension, in accordance with various embodiments. The coupling end <NUM> may further comprise a plurality of bypass flow apertures <NUM>.

With reference to <FIG> and <FIG>, during strut compression, oil flows from oil chamber <NUM> through main orifice assembly <NUM> and into orifice support tube <NUM>. During the strut compression, main orifice plate <NUM> may be configured to travel axial in coupling end <NUM> of orifice support tube <NUM> and contact an axial surface <NUM> of coupling end <NUM>. By contacting the axial surface <NUM> of coupling end <NUM>, the main orifice plate <NUM> may act as a seal between the oil flow between oil chamber <NUM> and orifice support tube <NUM> and the plurality of bypass flow apertures <NUM>.

With reference now to <FIG> and <FIG>, during strut extension, oil flows from orifice support tube <NUM> through the main orifice assembly <NUM> and into oil chamber <NUM>. The main orifice plate <NUM> may be configured to separate axially from axial surface <NUM> of coupling end <NUM>. In this regard, a bypass flow path may be created between the axial surface <NUM> and an axial surface <NUM> of main orifice plate <NUM> through the plurality of bypass flow apertures <NUM>. The separation between the axial surface <NUM> of the coupling end <NUM> and the axial surface <NUM> of the main orifice plate may be separated by a gap G1. The gap G1 may be a design consideration and/or may be varied based on damping actor angle to meet a desired damping curve for a damping actor configuration. For example, G1 may vary for a given main orifice plate <NUM> as a function of circumferential position, or G1 may be fixed and varied based on initial design considerations. In a design where G1 varies as a function of circumferential position, a gap G1 can correspond with a damping actor configuration to either provide higher damping or lower damping. For example, a larger G1 may corresponded to a lesser damping curve, whereas a smaller G1 may correspond to a greater damping curve.

Referring now to <FIG>, a main orifice assembly <NUM>, in accordance with various embodiments, is illustrated. Main orifice assembly <NUM> may further comprise first spring <NUM> coupled to first flow restrictor <NUM> and second spring <NUM> coupled to second flow restrictor <NUM>. Each spring <NUM>, <NUM> may be any spring known in the art, such as a mooring ring spring, or the like. Each flow restrictor may further comprise a spring pocket defined at least partially by first recess <NUM> and second recess <NUM>, as defined in <FIG>. For example, first flow restrictor <NUM> may comprise a spring pocket <NUM> configured to house the first spring <NUM>.

In various embodiments, each spring deflection curve may be relatively flat (i.e., the curve may plateau at a threshold displacement). A spring force of each spring may be minimized resulting in reduced torque to change damping actor configurations and reducing restriction of the flow restrictors for oil refilling the hydraulic chamber when the strut is extending.

Referring now to <FIG>, a main orifice plate assembly <NUM> and a metering pin <NUM>, in accordance with various embodiments, is illustrated. In various embodiments, orifice plate assembly <NUM> may comprise a metering plate <NUM>, a first flow restrictor <NUM> coupled to the main orifice plate <NUM> and as second flow restrictor <NUM> coupled to the main orifice plate <NUM>. In various embodiments, a first lug and a second lug in the plurality of lugs may be coupled to a respective flow restrictor. For example, first lug <NUM> and second lug <NUM> may define a flange fork. A head portion <NUM> of first flow restrictor <NUM> may be disposed in the flange fork. With combined reference to <FIG> and <FIG>, a pin may be disposed through a first aperture <NUM> of first lug <NUM> through aperture <NUM> of head portion <NUM> and through a corresponding second aperture of second lug <NUM>. The pin may act as a fulcrum for the first flow restrictor to rotate about.

In various embodiments, each lug in the plurality of lugs may extend axially beyond the head portion <NUM> of a respective flow restrictor. In this regard, each lug in the plurality of lugs <NUM> may restrict flow around the respective flow restrictor when positioned for maximum flute depth. A consistent level of leakage may be set based on a distance between each lug in the plurality of lugs <NUM> and the metering pin <NUM>.

Referring now to <FIG>, a portion of a shock strut assembly <NUM> including a main orifice assembly <NUM> from a bottom view, in accordance with various embodiments, is illustrated. "Bottom view," as referred to herein is a view looking from damping actor selector <NUM> towards orifice support tube <NUM> in <FIG>. In various embodiments, shock strut assembly <NUM> is for a steerable gear.

Referring back to <FIG>, a "steering angle," as defined herein, is a relative clock angle between the strut cylinder <NUM> and the strut piston <NUM>. A "damping actor selector (DAS) angle" as defined herein is a relative clock angle between the metering pin <NUM> and the strut piston <NUM>. In various embodiments, the damping actor selector <NUM> rotates the metering pin <NUM> relative to the strut piston <NUM> and steering rotates the strut piston <NUM> relative to the strut cylinder <NUM>. As such, the actor angle may be the sum of both the steering angle and the DAS angle.

As a steerable gear, the steering angle of shock strut assembly <NUM> may be approximately <NUM> degrees. However, steering during a first damping actor configuration <NUM> may be limited to a first steering range and/or steering during a second damping actor configuration <NUM> may be limited to a second steering range. The steering ranges of each damping actor configuration may be a design choice.

Referring back to <FIG>, an actor angle <NUM> may be defined between a first damping actor configuration <NUM> and a second damping actor configuration <NUM> based on a steering range of each damping actor configuration. For example, with reference to <FIG> and <FIG>, if a first damping actor configuration <NUM> has <NUM> degrees of steering (-<NUM> degrees to <NUM> degrees from a neutral position), and the second damping actor configuration <NUM> has <NUM> degrees of steering (-<NUM> degrees to <NUM> degrees from a neutral position), and the neutral positions of the first damping actor configuration <NUM> and the second damping actor configuration <NUM> are <NUM> degrees apart (i.e., a <NUM> degree actor angle), a guide ramp <NUM> of an orbit cam <NUM> may span <NUM> degrees maximum (e.g., <NUM> degrees - <NUM> degrees - <NUM> degrees). Additionally, in this configuration, the start of the guide ramp may be at least <NUM> degrees from a first mating surface <NUM> and the maximum axial distance D1 may occur at a maximum of <NUM> degrees. Furthermore, the maximum axial distance D1 of the guide ramp may span at least <NUM> degrees, corresponding, at a minimum, to the steering angle while in the second damping actor configuration.

Referring to <FIG> and <FIG>, to change damping actor configuration (i.e., from first damping actor configuration <NUM> to second damping actor configuration <NUM>), the damping actor selector <NUM> may rotate the metering pin clockwise or counterclockwise by the actor angle (e.g., <NUM> degrees in <FIG>). In various embodiments, first damping actor configuration <NUM> may correspond to a first flow restrictor <NUM> and second flow restrictor <NUM> being fully retracted. In various embodiments, second damping actor configuration <NUM> may correspond to the first flow restrictor <NUM> and the second flow restrictor <NUM> being fully deployed. In various embodiments, first damping actor configuration may correspond to a damping curve configured for landing of an aircraft. In various embodiments, the second damping actor configuration may correspond to catapult of an aircraft.

Referring now to <FIG>, a portion of a shock strut assembly <NUM> including a main orifice assembly <NUM> from a bottom view, in accordance with various embodiments, is illustrated. In various embodiments, shock strut assembly <NUM> is for a non-steerable gear. In various embodiments, a non-steerable gear may be configured to have multiple damping actor configurations. For example, a shock strut assembly <NUM> for a non-steerable gear may comprise a first damping actor configuration <NUM>, a second damping actor configuration <NUM>, a third damping actor configuration <NUM>, and/or a fourth damping actor configuration <NUM>.

In various embodiments, the first damping actor configuration <NUM> may correspond to a damping curve designed for a percolation event. Percolation occurs when restriction of gas and oil flow across the main orifice assembly <NUM> when the hydraulic chamber is refilling after a landing gear has been stowed for flight. In the first damping actor configuration <NUM>, the main orifice assembly <NUM> may open a large flow area between the hydraulic and gas chambers in order to facilitate a gas/oil migration between the chambers. This may allow an aircraft to safely land within a shorter time interval after lowering a gear.

In various embodiments, the second damping actor configuration <NUM> may correspond to a damping curve designed for conventional takeoff and land (CTOL). In various embodiments, the third damping actor configuration <NUM> may correspond to a damping curve designed for short takeoff and vertical landing (STOVL). The third damping actor configuration <NUM> may be tuned for vertical landings. For example, the third damping configuration may provide greater energy absorption since spin-up and spring back effects may have less influence. The third damping actor configuration may also correspond to a damping curve designed for rough terrain.

In various embodiments, the fourth damping actor configuration <NUM> may correspond to a damping curve designed for taxi of an aircraft. The fourth damping actor configuration may be optimized for ride quality, or the like.

In various embodiments and with additional reference to <FIG>, a schematic block diagram of a control system <NUM> for damping actor selector <NUM> is illustrated. Control system <NUM> includes a controller <NUM> in electronic communication with a launch bar lock <NUM> and a sensor <NUM>. In various embodiments, controller <NUM> may be integrated into computer systems onboard aircraft. In various embodiments, controller <NUM> may be configured as a central network element or hub to access various systems, engines, and components of control system <NUM>. Controller <NUM> may comprise a network, computer-based system, and/or software components configured to provide an access point to various systems, engines, and components of control system <NUM>. In various embodiments, controller <NUM> may comprise a processor. In various embodiments, controller <NUM> may be implemented in a single processor. In various embodiments, controller <NUM> may be implemented as and may include one or more processors and/or one or more tangible, non-transitory memories and be capable of implementing logic. Each processor can be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. Controller <NUM> may comprise a processor configured to implement various logical operations in response to execution of instructions, for example, instructions stored on a non-transitory, tangible, computer-readable medium configured to communicate with controller <NUM>.

System program instructions and/or controller instructions may be loaded onto a non-transitory, tangible computer-readable medium having instructions stored thereon that, in response to execution by a controller, cause the controller to perform various operations. The term "non-transitory" is to be understood to remove only propagating transitory signals per se from the claim scope and does not relinquish rights to all standard computer-readable media that are not only propagating transitory signals per se. Stated another way, the meaning of the term "non-transitory computer-readable medium" and "non-transitory computer-readable storage medium" should be construed to exclude only those types of transitory computer-readable media which were found in In Re Nuijten to fall outside the scope of patentable subject matter under <NUM> U.

In various embodiments, controller <NUM> may be in electronic communication with launch bar lock <NUM> and/or sensor <NUM>. When launch bar lock <NUM> is on, a switch may be closed and the launch bar lock <NUM> may be engaged/locked. When launch bar lock <NUM> is off, a switch may be closed, and the aircraft may be configured for a catapult launch. Sensor <NUM> may comprise any load cell known in the art, such as a compression load cell, or the like. Sensor <NUM> may be configured to measure a weight of on wheels and indicate whether the aircraft is on ground. Sensor <NUM> and launch bar lock <NUM> may be configured to transmit signals to controller <NUM>, thereby providing a phase of flight to controller <NUM>.

In various embodiments, controller <NUM> may receive a catapult command to extend a launch bar lock <NUM> to a deck in order to configure the aircraft for a catapult launch. In response to the catapult command, the controller <NUM> may command the damping actor selector <NUM> to transition from a first damping actor configuration to a second damping actor configuration. In response, the damping actor selector <NUM> may rotate the metering pin <NUM> and the main orifice plate <NUM> in a first direction about a central axis of the metering pin <NUM> and/or deploy a first flow restrictor <NUM> and/or a second flow restrictor <NUM>. In various embodiments, when the sensor <NUM> no longer measures a weight on wheels of the aircraft, the controller <NUM> may command the damping actor selector <NUM> to transition back from the second damping actor configuration to the first damping actor configuration. In this regard, the damping actor selector <NUM> may rotate the metering pin <NUM> and the main orifice plate <NUM> in a second direction about the central axis of the metering pin <NUM> and/or retract the first flow restrictor <NUM> and or the second flow restrictor <NUM>. The second direction may be opposite of the first direction.

In various embodiments, the launch bar lock <NUM> may re-engage after catapult launch. In response, if the sensor still measures a weight on wheels when the launch bar lock <NUM> re-engages a lock, the controller <NUM> may command the damping actor selector <NUM> to transition back from the second damping actor configuration to the first damping actor configuration. In this regard, the damping actor selector <NUM> may rotate the metering pin <NUM> and the main orifice plate <NUM> in a second direction about the central axis of the metering pin <NUM> and/or retract the first flow restrictor <NUM> and or the second flow restrictor <NUM>. The second direction may be opposite of the first direction.

In various embodiments, the controller <NUM> may command the launch bar lock <NUM> to re-engage after catapult launch. In response, if the sensor still measures a weight on wheels, the controller <NUM> may command the damping actor selector <NUM> to transition back from the second damping actor configuration to the first damping actor configuration. In this regard, the damping actor selector <NUM> may rotate the metering pin <NUM> and the main orifice plate <NUM> in a second direction about the central axis of the metering pin <NUM> and/or retract the first flow restrictor <NUM> and or the second flow restrictor <NUM>. The second direction may be opposite of the first direction.

Referring now to <FIG>, a method <NUM> of setting an actor angle of a multi-actor damping system is illustrated, in accordance with various embodiments. The method comprises rotating, via a damping actor selector, a metering pin about a central axis of the metering pin in a first direction from a default position (step <NUM>). The default position may correspond to a first damping actor configuration. The first damping actor configuration may comprise a damping curve configured for convention landing or the like. The damping actor selector may be in accordance with damping actor selector <NUM>. The method may further comprise setting, via the damping actor selector, a first actor angle of the multi-actor damping system (step <NUM>). The first actor angle may correspond to a second damping actor configuration. The second damping actor configuration may comprise a damping curve configured for catapult launch, or the like.

The method may further comprise rotating, via the damping actor selector, the metering pin about the central axis of the metering pin in a second direction (step <NUM>). In various embodiments, the second direction may be the same as the first direction in a multi-actor damping system where with more than two damping actor configurations (e.g., for a non-steerable landing gear). In various embodiments, the second direction may be opposite the first direction in a multi-actor damping system where there are only two damping actor configurations (e.g., for a steerable landing gear). The method may further comprise setting a second actor angle (step <NUM>). The second actor angle may be different than the first actor angle. The second actor angle may correspond to the first damping actor configuration or a third damping actor configuration. The second actor angle may be the negative first actor angle in a steerable landing gear system. The third damping actor configuration may comprise a damping curve configured for short takeoff and vertical landing, taxi, or the like.

Claim 1:
A shock strut assembly, comprising:
a strut cylinder (<NUM>) including a primary chamber (<NUM>);
a strut piston (<NUM>), the strut cylinder configured to receive the strut piston;
an orifice support tube (<NUM>) positioned within the primary chamber of the strut cylinder;
a main orifice assembly (<NUM>) disposed within the orifice support tube, the main orifice assembly including a main orifice plate (<NUM>);
a metering pin (<NUM>) positioned within the primary chamber, the metering pin defining an axis; characterized by
a damping actor selector (<NUM>) operably coupled to the main orifice plate, the damping actor selector configured to rotate the main orifice plate and transition the shock strut assembly from a first damping actor configuration to a second damping actor configuration, wherein:
the damping selector comprises a piston head coupled to the metering pin (<NUM>); and
the metering pin (<NUM>) rotates in response to the piston head travelling linearly along the axis.