Power-free up-lock mechanism for landing gear

An up-lock apparatus for landing gear of an aircraft includes a hook member configured to receive an up-lock roller pin of the landing gear when the landing gear is retracted. An up-lock actuator is coupled to the hook member and is configured to maintain the hook member in a locked state responsive to a first movement of the up-lock roller pin against the hook member to thereby prevent deployment of the landing gear. The up-lock actuator is further configured to allow the hook member to move to a released state responsive to a second movement of the up-lock roller pin against the hook member to facilitate deployment of the landing gear.

FIELD

This application generally relates to aircraft landing gear systems. In particular, this application describes a power-free up-lock apparatus for landing gear of aircraft.

BACKGROUND

Some aircraft utilize retractable landing gear systems. The landing gear system may include an actuator that moves the landing gear between stowed and deployed states. For example, the actuator may be controlled in a first operation to cause the landing gear to be stowed within a landing gear bay of the aircraft. The actuator may be controlled in a second operation to cause the landing gear to deploy from the landing gear bay of the aircraft.

In some cases, the landing gear system may include an up-lock apparatus to maintain the landing gear in the landing gear bay during flight. Locking the landing gear in the landing gear bay (i) ensures that the landing gear will not inadvertently deploy, and (ii) facilitates de-energizing the landing gear actuator.

SUMMARY

In a first aspect, an up-lock apparatus for landing gear of an aircraft is disclosed. The up-lock apparatus includes a hook member configured to receive an up-lock roller pin of the landing gear when the landing gear is retracted. An up-lock actuator is coupled to the hook member and is configured to maintain the hook member in a locked state responsive to a first movement of the up-lock roller pin against the hook member to thereby prevent deployment of the landing gear. The up-lock actuator is further configured to allow the hook member to move to a released state responsive to a second movement of the up-lock roller pin against the hook member to facilitate deployment of the landing gear.

In a second aspect, an aircraft with landing gear is disclosed. The landing gear includes an up-lock roller pin. A hook member is configured to receive the up-lock roller pin of the landing gear when the landing gear is retracted. An up-lock actuator is coupled to the hook member and is configured to maintain the hook member in a locked state responsive to a first movement of the up-lock roller pin against the hook member to thereby prevent deployment of the landing gear. The up-lock actuator is further configured to allow the hook member to move to a released state responsive to a second movement of the up-lock roller pin against the hook member to facilitate deployment of the landing gear.

In a third aspect, a method for securing landing gear of an aircraft is disclosed. The method includes receiving, by a hook member, an up-lock roller pin of the landing gear when the landing gear is retracted. The method further includes maintaining, by an up-lock actuator coupled to the hook member, the hook member in a locked state responsive to a first movement of the up-lock roller pin against the hook member to thereby prevent deployment of the landing gear. The hook member is allowed to move to a released state responsive to a second movement of the up-lock roller pin against the hook member to facilitate deployment of the landing gear.

DETAILED DESCRIPTION

Various examples of systems, devices, and/or methods are described herein. Words such as “example” and “exemplary” that may be used herein are understood to mean “serving as an example, instance, or illustration.” Any implementation, and/or feature described herein as being an “example” or “exemplary” is not necessarily to be construed as preferred or advantageous over any other embodiment, implementation, and/or feature unless stated as such. Thus, other embodiments, implementations, and/or features may be utilized, and other changes may be made without departing from the scope of the subject matter presented herein.

Moreover, terms such as “substantially,” or “about” that may be used herein, are meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including, for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of ordinary skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

Introduction

As noted above, landing gear systems may utilize an up-lock apparatus to lock the landing gear in a stowed state. In some cases, the up-lock apparatus may include a powered latch to secure the landing gear in the stowed state. For example, when stowing the landing gear, an up-lock roller pin of the landing gear may move into the up-lock apparatus as the landing gear moves to the stowed state. Afterward, a latch of the up-lock apparatus may be energized, or de-energized as the case may be, to maintain the up-lock roller pin in the up-lock apparatus, which prevents the landing gear from moving to a deployed state.

To deploy the landing gear, the latch may be de-energized, or energized as the case may be, to allow the up-lock apparatus to release the up-lock roller pin of the landing gear, which allows the landing gear to move to the deployed state.

The examples disclosed herein include an up-lock apparatus for maintaining landing gear in the stowed state without the use of an energized latch. For example, an up-lock apparatus may include a hook member and an actuator coupled to the hook member. The hook member is configured to receive an up-lock roller pin of the landing gear when the landing gear is retracted. The actuator is configured to maintain the hook member in a locked state responsive to a first movement of the up-lock roller pin against the hook member to thereby prevent deployment of the landing gear. The actuator is further configured to allow the hook member to move to a released state responsive to a second movement of the up-lock roller pin against the hook member to facilitate deployment of the landing gear.

FIG.1illustrates an aircraft100. The aircraft includes landing gear105and an up-lock apparatus205. The up-lock apparatus205is utilized to secure the landing gear105in a stowed state. Landing gear105in the stowed state is illustrated in the dashed lines. The landing gear105includes an up-lock roller pin215. The up-lock apparatus205includes a hook member305and an up-lock actuator310. The hook member305is configured to receive the up-lock roller pin215of the landing gear105when the landing gear105is retracted. The up-lock actuator310is coupled to the hook member305. The up-lock actuator310is configured to maintain the hook member305in a locked state responsive to a first movement of the up-lock roller pin215against the hook member305to thereby prevent deployment of the landing gear105. The up-lock actuator310is further configured to allow the hook member305to move to a released state responsive to a second movement of the up-lock roller pin215against the hook member305to facilitate deployment of the landing gear105.

In an example, the aircraft100may correspond to a large commercial passenger jet that includes a retractable landing gear system. In this regard, the landing gear105of the aircraft100may be arranged in the wings or in the fuselage of the aircraft100. The landing gear105may be controlled to deploy, as illustrated, to support the weight of the aircraft100. The landing gear105may be controlled to retract into, for example, a landing gear bay110of the aircraft100, which may be arranged within the wings and/or fuselage of the aircraft100.

It should be noted that while the examples described herein may be described in connection with a commercial passenger jet, the examples may be adapted for use in other types of aircraft. For example, the examples may be utilized in other aircraft100that utilize retractable landing gear such as cargo jets, small/private passenger jets, helicopters, etc.

FIG.2illustrates an example of a landing gear system200. The landing gear system200includes landing gear105and an example of an up-lock apparatus205. The landing gear105includes a strut210, an up-lock roller pin215, and wheels220. The wheels220are coupled to a first end225of the strut210. A second end230of the strut210may be coupled to an actuator (not shown) that controls the strut210to rotate in direction A between the deployed states (SeeFIG.1) and stowed states. In the stowed state, the strut210may be controlled to come to rest in a generally horizontal position, as illustrated. In the horizontal position, the landing gear105may be entirely disposed with the landing gear bay110of the aircraft100.

The up-lock roller pin215may be coupled to a central section of the strut210. The up-lock roller pin215may be configured to engage the up-lock apparatus205. When engaged, the up-lock apparatus205is configured to releasably secure the up-lock roller pin215and, therefore, secure the landing gear105in a generally horizontal position within the landing gear bay110.

FIG.3illustrates an example of an up-lock apparatus205that may correspond to the up-lock apparatus205ofFIG.2. The up-lock apparatus205includes a hook member305and an up-lock actuator310.

The hook member305may be configured to receive the up-lock roller pin215of the landing gear105when the landing gear105is retracted.

The up-lock actuator may be coupled to the hook member. The up-lock actuator may be configured to maintain the hook member in a locked state responsive to a first movement of the up-lock roller pin against the hook member to thereby prevent deployment of the landing gear. The up-lock actuator may be further configured to allow the hook member to move to a released state responsive to a second movement of the up-lock roller pin against the hook member to facilitate deployment of the landing gear.

Another example of the up-lock apparatus205may include a hook member305, an up-lock actuator310, a hook pin315, a resilient member320, and a sensor325.

The hook member305is configured to receive the up-lock roller pin215of the landing gear105when the landing gear105is retracted. In this regard, the hook member305may define a jaw330having an upper-jaw section335and a lower-jaw section340configured to receive the up-lock roller pin215of the landing gear105.

When receiving the up-lock roller pin215, the hook member305is configured to pivot around the hook pin315. In this regard, the upper-jaw section335may be configured to be engaged by the up-lock roller pin215during an upward movement of the up-lock roller pin215against the hook member305. The lower-jaw section340is configured to support the up-lock roller pin215when the landing gear105is retracted to thereby maintain the landing gear105in the retracted state. In this regard, the hook member305may be formed from a material such as a metal material or other durable material suitable for supporting the landing gear105. The hook member305and/or the lower-jaw section340of the hook member305may be dimensioned to support the weight of the landing gear105.

FIGS.4A-4Cillustrates the hook member305receiving the up-lock roller pin215of the landing gear105when the landing gear105is retracted. InFIG.4A, the landing gear105is deployed. In this situation, the hook member305is urged in a generally downward direction (i.e., the released state) by the resilient member320(FIG.3). The hook member305may include features such as a stop (not shown) configured to maintain the hook member305in a position suitable for receiving the up-lock roller pin215of the landing gear105when urged by the resilient member320to the released state.

InFIG.4B, the landing gear actuator is controlled to cause the landing gear105to begin a retraction operation. InFIG.4C, the landing gear105is fully retracted. In the fully retracted state, the hook member305is rotated about the hook pin315to a locked state that corresponds to a generally horizontal position. In the locked state, the up-lock roller pin215is supported by the hook member305to maintain the landing gear105in the retracted state.

Returning toFIG.3, the up-lock actuator310is coupled to the hook member305. The up-lock actuator310may include a piston rod350, which is part of a piston702(FIG.7), and a cylinder355. In some examples, the up-lock actuator310may include an auxiliary locking mechanism360. The piston rod350is configured to be moveable relative to the cylinder355between a retracted position and an extended position.

A first end352of the piston rod350may be configured to rotatably couple to the hook member305. In this regard, the first end352may include a coupler717(FIG.7). The coupler717(FIG.7) may be rotatably coupled to the first end352of the piston rod350. The coupler may facilitate rotatably coupling the piston rod350to the hook member305according to two degrees of freedom. A second end707of the piston rod350may be coupled to a piston head705(FIG.7), details of which are provided below. The piston head705is disposed within the cylinder355.

The cylinder355may include a closed cap-end354and an opening at a rod-end358through which the piston rod350extends. The cap-end354of the cylinder355may include a coupler357that facilitates rotatable coupling of the cap-end354of the cylinder355to a structure (not shown) within the landing gear105of the aircraft100.

The cylinder355may be filled with a fluid such as hydraulic fluid that facilitates smooth transitioning of the piston rod350between the retracted position and the extended position. The hydraulic fluid may further help prevent corrosion from developing within the cylinder355and/or on the piston rod350or piston head705that may inhibit movement of the piston rod350within the cylinder355.

In operation, the up-lock actuator310is configured to alternate the hook member305between one of two states responsive to movement of the up-lock roller pin215against the hook member305. For example, a first movement of the up-lock roller pin215against the hook member305may cause the hook member305to move to a locked state to prevent deployment of the landing gear105. A second movement of the up-lock roller pin215against the hook member305may cause the hook member305to move to a released state to facilitate deployment of the landing gear105. A third movement of the up-lock roller pin215against the hook member305may cause the hook member305to move back to the locked state to prevent deployment of the landing gear105. A fourth movement of the up-lock roller pin215against the hook member305may cause the hook member305to move back to the released state to facilitate deployment of the landing gear105.

The auxiliary locking mechanism360may be provided in some examples where upside-down flight by the aircraft100is expected. For example, operations described herein with respect to the auxiliary locking mechanism360may be enabled when the aircraft100is flying upside down and disabled when the aircraft100is flying upright.

When enabled, the auxiliary locking mechanism360is configured to lock the piston rod350in the retracted position by, for example, preventing rotation of the piston rod350. The auxiliary locking mechanism360may include a body member362, an interference member364slidably coupled to the body member362, and an actuator (not shown) for moving the interference member364within the body member362. In operation, the actuator may be controlled to slide the interference member364relative to the body member362so that an interference end of the interference member engages the piston rod350. In this regard, the piston rod350may define a feature proximate the first end352of the piston rod350for receiving the inference end of the interference member364. In an example, the interference member364may correspond to a pin. The interference end of the interference member364may correspond to the tip of the pin, and the feature in the piston rod350may correspond to a recess. The actuator may cause the tip of the pin to slide within the recess to prevent the piston rod350from rotating and/or extending. To allow for extension of the piston rod350, the actuator may be controlled to cause the inference member to slide away from the piston rod350.

FIGS.5A-5Cillustrate example locking operations performed by the up-lock actuator310described above.

FIG.5Aillustrates the hook member305of the up-lock apparatus205in a released state and the up-lock actuator310in the extended state. That is, the piston rod350of the up-lock actuator310is in a fully extended position. InFIG.5A, the landing gear105of the aircraft100may be controlled to retract into the landing gear bay110of the aircraft100. As such, the up-lock roller pin215of the landing gear105may be moving towards the hook member305, as indicated by the direction indicator.

InFIG.5B, continued upward movement of the up-lock roller pin215of the landing gear105causes the up-lock roller pin215to engage the upper-jaw section335of the hook member305. The engagement by the up-lock roller pin215causes the hook member305to rotate about the hook pin315so that the upper-jaw section335moves in an upward direction with the up-lock roller pin215. Rotation of the hook member305causes the piston rod350of the up-lock actuator310to retract within the cylinder355. Once fully retracted, the up-lock actuator310enters a limited extension state. InFIG.5B, the landing gear105is fully retracted within the landing gear bay110of the aircraft100.

InFIG.5C, the landing gear actuator may be de-energized. De-energization of the landing gear actuator may cause the landing gear105to begin moving in a downward direction due to the force of gravity. Under this situation, the up-lock roller pin215of the landing gear105begins to move in a downward direction as indicated by the direction indicator. The downward movement causes the hook member305to rotate about the hook pin315so that the upper-jaw section335moves in a downward direction with the up-lock roller pin215. Rotation of the hook member305causes the piston rod350of the up-lock actuator310to extend to an extent. However, because the up-lock actuator310is in the limited extension state, the amount by which the piston rod350is allowed to extend is limited to prevent the hook member305from continually rotating in the downward direction with the up-lock roller pin215. That is, the hook member305enters a locked state where it can no longer rotate in the downward direction with the up-lock roller pin215. With continued movement, the up-lock roller pin215engages and comes to rest on the lower-jaw section340of the hook member305. Support of the up-lock roller pin215by the lower-jaw section340of the hook member305prevents retraction of the landing gear105from the landing gear bay110.

FIGS.6A and6Billustrate example releasing operations performed by the up-lock actuator310described above.

InFIG.6A, the up-lock actuator310is initially in the limited extension state, which causes the hook member305to remain in the locked state. An initial operation for deploying the landing gear105from the landing gear bay110may be performed. During the initial operation, the landing gear actuator may be controlled to move the landing gear105in an upward direction to remove the weight of the landing gear105from the hook member305. As the landing gear105moves upward, the up-lock roller pin215moves off of the lower-jaw section340and engages the upper-jaw section335of the hook member305. Engagement of the upper-jaw section335causes the hook member305to rotate about the hook pin315so that the upper-jaw section335moves in an upward direction with the up-lock roller pin215. Rotation of the hook member305causes the piston rod350of the up-lock actuator310to retract within the cylinder355and remove the up-lock actuator310from the limited extension state.

InFIG.6B, a second operation for releasing the landing gear105from the landing gear bay110may be performed. During the second operation, the landing gear actuator may be de-energized or controlled to cause the release of the landing gear105from the landing gear bay110. Under this situation, the up-lock roller pin215of the landing gear105begins to move in a downward direction as indicated by the direction indicator. The downward movement of the up-lock roller pin215causes the hook member305to rotate about the hook pin315so that the upper-jaw section335moves in a downward direction with the up-lock roller pin215. Because the up-lock actuator310is no longer in the limited extension state, the up-lock actuator310is allowed to extend fully and, therefore, the hook member305is allowed to rotate to the released state. In the release state, the up-lock roller pin215of the landing gear105is allowed to move passed the lower-jaw section340, which in turn allows the landing gear105to deploy.

Returning toFIG.3, as indicated above, the resilient member320is configured to urge the hook member305towards the released state (SeeFIG.4A). In this regard, the resilient member320may correspond to a spring such as a coil spring. The resilient member320may be formed from a durable material such as a metal material. The resilient member320may be dimensioned to facilitate rotation of the hook member305between the released state and the locked state.

The sensor325is in mechanical communication with the hook member305. The sensor325is configured to facilitate the determination of whether the hook member305is in the locked state or the released state. For example, the sensor325may correspond to a rotary sensor. The rotary sensor may be positioned, for example, at the coupler357arranged at the cap-end354of the cylinder355to measure the amount by which the up-lock actuator310rotates. In another example, the rotary sensor may be position at the coupling between the hook member305and the first end352of the up-lock actuator310. A first amount of rotation by the up-lock actuator310may indicate that the hook member305is in the released state. A second amount of rotation by the up-lock actuator310may indicate that the hook member305is in the locked state.

In yet another example, the sensor325may correspond to a switch that is engaged by the hook member305and/or the up-lock actuator310when the hook member305is in the release stated and/or locked state.

The sensor325may be in communication with a control system (not shown) and/or an indicator (not shown) of the aircraft100. In this regard, the controller may include a processor and a non-transitory computer readable medium that stores instruction code executable by the processor that facilitates the performance, by the controller, of any of the controller related operations disclosed herein.

During a retraction operation, information provided by the sensor325(i.e., whether the hook member305is in the locked state), may be utilized by the controller to determine whether the landing gear105is locked within the landing gear bay110. For example, during a landing gear retraction operation, the controller may wait until receiving an indication that the up-lock member is in the locked state before de-energizing the landing gear actuator to thereby prevent inadvertent deployment of the landing gear105from the landing gear bay110. Information about the state of the hook member305of the up-lock apparatus205may be communicated to the pilot of the aircraft100via an indicator and may inform the pilot that the landing gear105is safely locked in the landing gear bay110.

Conversely, during a landing gear deployment operation (e.g.,FIGS.6B and6C), the controller may receive an indication that the hook member305of the up-lock apparatus205is not entering the release state. In this case, the controller may cause the landing gear105to move in a further upward direction in an attempt to cause the up-lock actuator310to leave the limited extension state and allow the hook member305to enter the release state. Information about the state of the hook member305may be communicated to the pilot of the aircraft100via an indicator and may inform the pilot that the landing gear105is safely deployed.

FIG.7illustrates an example of the interior of the up-lock actuator310that may correspond to the up-lock actuator310described above. The interior of the up-lock actuator310may include a piston702, a cap-end cam profile710, and a rod-end cam profile715. The piston702includes a piston head705and a piston rod350.

As noted above, the piston rod350of the up-lock actuator310may be configured to be moved longitudinally within the cylinder355of the up-lock actuator310between retracted and extended positions. The first end352of the piston rod350may be configured to be rotatably coupled to the hook member305. A second end707of the piston rod350may be coupled to the piston head705.

As noted above, the cylinder355may include a closed cap-end354and an opening at a rod-end358through which the piston rod350extends. The cap-end354of the cylinder355may include a coupler357that facilitates rotatable coupling of the cap-end354of the cylinder355to a structure (not shown) within the landing gear bay110of the aircraft100. The cylinder355may be filled with a fluid such as hydraulic fluid that facilitates smooth transitioning of the piston rod350between the extended and retracted positions, and the prevention of the formation of corrosion within the cylinder355.

The piston head705may be coupled to the second end707of the piston rod350. The piston head705is configured to move longitudinally within the cylinder355between a cap-end354of the cylinder355and a rod-end358of the cylinder355. In some examples, the piston head705includes a seal such as an elastomer seal (not shown) to prevent or control the flow of fluid passed the piston head705.

In an example, the piston head705includes a piston head cam profile (720and725). The piston head cam profile (720and725) includes a rod-side cam profile720on the rod-side of the piston head705, and a cap-side cam profile725on the cap-end side of the piston head705. The rod-side cam profile720of the piston head705is configured to engage a rod-end cam profile715of the cylinder355arranged in the inside of the cylinder355, proximate the rod-end358of the cylinder355. The cap-side cam profile725of the piston head705is configured to engage a cap-end cam profile710of the cylinder355arranged on the inside of the cylinder355, proximate the cap-end354of the cylinder355.

The cap-side cam profile725of the piston head705and the cap-end cam profile710of the cylinder355are configured so that when the respective cam profiles710and725engage one another, the piston head705rotates along the indicated axis, D, within the cylinder355by a first amount. For example, after a first engagement of the cap-side cam profile725of the piston head705and the cap-end cam profile710of the cylinder355, the piston head705may rotate 90 degrees to a first rotation state. After a second engagement of the cap-side cam profile725of the piston head705and the cap-end cam profile710of the cylinder355, the piston head705may rotate 90 degrees from the first rotation state to a second rotation state. In an example where the piston head705rotates by 90 degrees, the piston head705may rotate back to the first rotation state after a fourth engagement of the cap-side cam profile725of the piston head705and the cap-end cam profile710of the cylinder355.

In examples, the piston rod350rotates with the piston head705, and the first end352of the piston rod350is rotatably coupled to the hook member305according to two degrees of freedom.

The rod-side cam profile720of the piston head705and the rod-end cam profile715of the cylinder355are configured to allow the piston rod350to fully extend when the piston head705is at, for example, the first rotation state, and to restrict the amount by which the piston rod350may extend when the piston head705is at the second rotation state.

In an example, the rod-end cam profile715of the cylinder355and the rod-side cam profile720of the piston head705may be configured to allow the piston head705to move past the rod-end cam profile715of the cylinder355when the piston is at the first rotation state. The rod-end cam profile715of the cylinder355and the rod-side cam profile720of the piston head705may be further configured to prevent the piston head705from moving past the rod-end cam profile715of the cylinder355when the piston head705is at the second rotation state.

In the example where the piston head705rotates by 90 degrees each time the cap-side cam profile725of the piston head705engages the cap-end cam profile710of the cylinder355, the piston rod350may be allowed to fully extend when the piston is at the first and third rotation states, and the amount by which the piston rod350may extend may be restricted when the piston head705is at the second and fourth rotation states.

In examples, when allowed to extend fully, the piston rod350may be allowed to extend more than, for example, the 5 inches, 10 inches, 20 inches, or 50 inches. In examples, when the amount by which the piston rod is allowed to extend is restricted, the piston rod may be restricted to extending less than, for example, 1 inch, 2 inches, 4 inches, and 5 inches.

During operation of the up-lock apparatus205, when the up-lock apparatus205is in the release state, continued upward movement of the up-lock roller pin215of the landing gear105causes the piston rod350of the up-lock actuator310to retract within the cylinder355. When the piston rod350fully retracts, the piston head705may rotate to a first rotation state. At this stage, the up-lock actuator310enters a restricted extension state in which the rod-side cam profile720of the piston head705engages the rod-end cam profile715of the cylinder355to prevent the piston rod350from fully extending from the cylinder355. At this point, the hook member305of the up-lock apparatus205enters the locked state.

When the hook member305of the up-lock apparatus205is in the locked state, upward movement of the up-lock roller pin215causes the up-lock roller pin215of the landing gear105to engage the upper-jaw section335of the hook member305. Engagement of the upper-jaw section335causes the hook member305to rotate about the hook pin315so that the upper-jaw section335moves in an upward direction with the up-lock roller pin215. Rotation of the hook member305causes the piston rod350of the up-lock actuator310to retract within the cylinder355. When the piston rod350fully retracts, the piston head705may rotate to a second rotation state. At this stage, the piston rod350of the up-lock actuator310is allowed to extend fully, and the hook member305of the up-lock apparatus205enters the released state.

FIG.8illustrates a method for securing landing gear105of an aircraft100. Block800may involve receiving, by a hook member305, an up-lock roller pin215of the landing gear105when the landing gear105is retracted.

Block805may involve maintaining, by an up-lock actuator310coupled to the hook member305, the hook member305in a locked state responsive to a first movement of the up-lock roller pin215against the hook member305to thereby prevent deployment of the landing gear105.

Block810may involve allowing the hook member305to move to a released state responsive to a second movement of the up-lock roller pin215against the hook member305to facilitate deployment of the landing gear105.

Some examples may involve engaging, by the up-lock roller pin215, an upper-jaw section335of the hook member305during the first movement and the second movement of the up-lock roller pin215against the hook member305; and supporting, by a lower-jaw section340of the hook member305, the up-lock roller pin215when the landing gear105is retracted.

Some examples may involve moving a piston of the up-lock actuator310longitudinally within a cylinder355of the up-lock actuator310between a cap-end of the cylinder355and a rod-end358of the cylinder355; rotating a head of the piston, relative to the cylinder355, to a first rotation state responsive to engagement, by a head cam profile of the head of the piston, of a first cam profile proximate the cap-end of the cylinder355during the first movement of the up-lock roller pin215against the hook member305; and rotating the head of the piston, relative to the cylinder355, to a second rotation state responsive to engagement, by the head cam profile of the head of the piston, of the first cam profile proximate the cap-end of the cylinder355during the second movement of the up-lock roller pin215against the hook member305.

Some examples may involve extending a piston rod350of the piston by a first amount when the head is rotated to the first rotation state, and extending the piston rod350of the piston by a second amount, greater than the first amount, when the head is rotated to the second rotation state.

While the systems and methods of operation have been described with reference to certain examples, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the claims. Therefore, it is intended that the present methods and systems not be limited to the particular example disclosed, but that the disclosed methods and systems include all embodiments falling within the scope of the appended claims.