Landing gear with shortened motion

Abstract

A landing gear for a vehicle includes a strut configured to reciprocate between a stowed position and a deployed position. A shock absorber has a first element slidingly disposed within the strut and a second element slidingly coupled to the first element. A drag arm is rotatably coupled to the second element. A first linkage is coupled to the first element, wherein the first linkage drives the first element between a raised position when the strut is in the stowed position and a lowered position when the strut is in the deployed position. The landing gear further includes a second linkage coupled to the drag arm. The second linkage rotates the drag arm between a first drag arm position when the strut is in the stowed position and a second drag arm position when the strut is in the deployed position.

Description

BACKGROUND

[0001] An aircraft landing gear bay is a space within an aircraft that is configured to house a retracted landing gear. The landing gear is typically specifically designed for the aircraft, and the landing gear bay is designed to accommodate the landing gear.

[0002] To improve fuel efficiency, existing aircraft are often reconfigured to use larger gas turbine engines. To provide sufficient ground clearance for these larger engines, the landing gear is lengthened to raise the aircraft relative to the ground when supported by the landing gear. However, these longer landing gears must still fit into the existing landing gear bays when retracted.

[0003] Even when the landing gear bay can be designed to accommodate longer landing gears (e.g., for new aircraft), it is beneficial to maintain a smaller landing gear bay. The inner boundary of the landing gear enclosure is limited by the keel beam, which extends along the centerline of the aircraft. Thus, longer landing gears will typically be attached further outward on the wings; however, moving the attachment point of the landing gear outward in this way increases the size of the taxiway and runway required for the aircraft. Moving the attachment point of the landing gear further outward can also result in increased airport fees, which are often based in part on the width from one landing gear wheel to the opposite landing gear wheel.

[0004] In view of the above, it would be advantageous to provide a landing gear having an increased length when extended that does not require a larger landing gear bay. Thus, it would be desirable to have a device that maintains the length of the landing gear in the extended position but reduces the length during retraction.

[0005] U.S. Patent No. 10,442,527 (“Bennett”), issued October 15, 2019, and now assigned to Safran Landing Systems UK LTD, the disclosure of which is expressly incorporated herein, discloses a shortening system. Bennett teaches an aircraft landing gear in which shock absorbers extend from and retract into landing gear struts as the landing gear moves toward the deployed and retracted positions, respectively. Because the landing gear wheels are coupled to the shock absorbers, retracting the shock absorbers into the struts as the landing gear moves toward the retracted position reduces the overall length of the retracted landing gear compared to the extended landing gear.

[0006] “Shortening” systems such as those included on the landing gear disclosed in Bennett are limited in the total amount of length reduction they are able to provide. In some cases, the amount of shortening provided can be less than desirable or necessary. Thus, there is a need for a landing gear having improved shortening capabilities. SUMMARY

[0007] Embodiments of a landing gear for an aircraft having a shortening mechanism are set forth below in accordance with the techniques and methods of the present invention. The shortening mechanism mechanically pulls the shock absorber upward within the landing gear strut. The shortening mechanism also provides a rotatable trailing arm for mounting one or more wheels to the landing gear. As the landing gear moves from a stowed position to a deployed position, the trailing arm rotates to move the one or more wheels toward an upper end of the landing gear, thereby further shortening the overall length of the landing gear.

[0008] A representative embodiment of a landing gear for a vehicle includes a strut configured to reciprocate between a stowed position and a deployed position. A shock absorber has a first element slidingly disposed within the strut and a second element slidingly coupled to the first element. A trailing arm is rotatably coupled to the first element, and a first end of the trailing arm has a wheel rotatably mounted thereto. A first linkage is coupled to the second element to drive the second element between a raised position when the strut is in the stowed position and a lowered position when the strut is in the deployed position. A second linkage is coupled to the trailing arm to rotate the trailing arm between a first trailing arm position when the strut is in the stowed position and a second trailing arm position when the strut is in the deployed position.

[0009] In any embodiment, the first linkage includes a first link rotatably coupled at a first end to the strut and at a second end to a first end of a second link, the second link being coupled at a second end to the first element.

[0010] In any embodiment, the second link includes a second link engagement surface that contacts an inner surface of the strut when the strut is in the deployed position, wherein an axial load applied to the shock absorber drives the second link engagement surface toward the inner surface of the strut.

[0011] In any embodiment, the landing gear further includes an operating lever fixedly coupled to the first link and a drive lever having a first end pivotably coupled to the operating lever. Rotation of the drive lever moves the second link engagement surface away from the inner surface of the strut as the strut moves toward the stowed position.

[0012] In any embodiment, the strut is rotatably coupled about an axis, and the drive lever is pivotably coupled about a point that is fixedly positioned relative to the axis.

[0013] In any embodiment, the second linkage includes a positioning lever pivotably coupled to the operating lever, wherein rotation of the operating lever drives the positioning lever to rotate the trailing arm.

[0014] In any embodiment, the second linkage further includes a positioning link rotatably mounted to the strut and a lowering link rotatably mounted at a first end to the positioning link and at a second end to a second end of the trailing arm.

[0015] In any embodiment, the landing gear further includes a strut engagement surface formed on the strut and a positioning link engagement surface formed on the positioning link, wherein the strut engagement surface engages the positioning link engagement surface when the strut is in the deployed position.

[0016] In any embodiment, a tensile load applied to the drop link when the strut is in the deployed position pushes the positioning link engagement surface toward the strut engagement surface.

[0017] In any embodiment, the tensile load in the drop link is reacted by the strut through contact between the positioning link engagement surface and the strut engagement surface.

[0018] In any embodiment, the tensile load in the drop link is generated by a vertical load applied to the wheel.

[0019] In any embodiment, the landing gear further includes a side brace coupled to the strut at one end, wherein a first end of the second link mechanism is coupled to the side brace and a second end of the second link mechanism is coupled to the trailing arm, movement of the side brace as the landing gear reciprocates between the deployed position and the stowed position rotates the trailing arm.

[0020] In any embodiment, the second link mechanism includes a positioning link rotatably mounted to the strut. The drop link is rotatably mounted to the positioning link at a first end and rotatably mounted to a second end of the trailing arm at a second end.

[0021] In any embodiment, the landing gear further includes a rotary actuator operably coupled to the second link mechanism and configured to rotate the trailing arm as the landing gear reciprocates between the deployed position and the stowed position.

[0022] In any embodiment, the second link mechanism further includes a positioning link rotatably mounted to the strut. The drop link is rotatably mounted to the positioning link at a first end and rotatably mounted to a second end of the trailing arm at a second end.

[0023] In any embodiment, the first element is a piston and the second element is a cylinder, wherein the piston is partially disposed within the cylinder.

[0024] In any embodiment, the first element is a cylinder and the second element is a piston partially disposed within the cylinder.

[0025] Another representative embodiment of a landing gear is an aircraft landing gear including a strut configured to reciprocate between a stowed position and a deployed position. The landing gear includes a shock absorber having a cylinder and a piston, wherein a first end of the piston is slidingly disposed within the strut and a second end of the piston is slidingly disposed within the cylinder, the cylinder extending from an end of the strut. A drag link is rotatably coupled to the cylinder and a first end of the drag link has a wheel rotatably mounted thereto. The landing gear further includes a first linkage and a second linkage. The first linkage is coupled to the piston and drives the piston between a raised position when the strut is in the stowed position and a lowered position when the strut is in the deployed position. The second linkage is coupled to the drag link and rotates the drag link between a first drag link position when the strut is in the stowed position and a second drag link position when the strut is in the deployed position.

[0026] This summary is provided to introduce a selection of concepts, in a simplified form, that are further described below in the DETAILED DESCRIPTION. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. BRIEF DESCRIPTION OF DRAWINGS

[0027] The foregoing aspects and many of the attendant advantages of the disclosed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when considered in connection with the accompanying drawings, wherein:

[0028] Figure 1 A top front isometric view of a first representative embodiment of a landing gear having a shortening mechanism according to the present invention is shown, wherein the landing gear is in a deployed position and positioned on a left side of an aircraft;

[0029] Figure 2 A side view thereof is shown, viewed outwardly therefrom;

[0030] Figure 3 A front view thereof is shown, viewed rearwardly therefrom;

[0031] Figure 4 A top view of the landing gear is shown, wherein the view is taken along a wheel centerline; Figure 1 A top view of the landing gear is shown, wherein the view is taken along a wheel centerline;

[0032] Figure 5 A front view of the landing gear is shown, wherein the view is orthogonal to a wheel centerline; Figure 4 A front view of the landing gear is shown, wherein the view is orthogonal to a wheel centerline;

[0033] Figure 6 A rear partial cross-sectional view of the landing gear is shown, wherein the landing gear is in a deployed position and the view is taken along a centerline of the trunnion; Figure 1 A rear partial cross-sectional view of the landing gear is shown, wherein the landing gear is in a deployed position and the view is taken along a centerline of the trunnion;

[0034] Figure 7 A rear partial cross-sectional view of the landing gear is shown, wherein the landing gear is in a deployed position and the view is taken along a centerline of the trunnion;Figure 6 enlarged partial view of

[0035] Figure 8 illustrates Figure 1 a front partial cross-sectional view of the landing gear shown, with the landing gear in the deployed position, and the view taken along the centerline of the trunnion;

[0036] Figure 9 illustrates Figure 2 enlarged partial view of

[0037] Figure 10 illustrates Figure 4 enlarged partial view of

[0038] Figure 11 illustrates a top front isometric view of a second representative embodiment of a landing gear having a shortening mechanism according to the present application, with the landing gear in the deployed position;

[0039] Figure 12 illustrates Figure 11 a top front isometric view of the landing gear shown, with the landing gear in the stowed position; and

[0040] Figure 13 illustrates a top front isometric view of a third representative embodiment of a landing gear having a shortening mechanism according to the present application, with the landing gear in the deployed position. DETAILED DESCRIPTION

[0041] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments in which the subject matter can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various embodiments of the subject matter. However, it will be apparent to those skilled in the art that the subject matter can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject matter.

[0042] Examples of landing gears having a shortening mechanism according to the techniques and methods of the present application are set forth below. In one embodiment, the shortening mechanism retracts a shock absorber into a strut and also rotates a drag arm to which a wheel is attached. The retraction of the shock absorber and the rotation of the drag arm provide improved shortening of the landing gear as the landing gear moves from the deployed position to the stowed position.

[0043] Figures 1 to 5 A representative embodiment of a landing gear 20 suitable for use on an aircraft is shown. Figures 1 to 3 The landing gear 20 is shown in the deployed position, and Figure 4 and Figure 5A landing gear in a stowed position is shown. Although various embodiments of landing gear configurations are described herein with respect to aircraft, it will be appreciated that the landing gear configurations can be used in other suitable vehicles that require a retractable landing gear to reciprocate between a stowed position and a deployed position, including, for example, maglev vehicles.

[0044] In the disclosed embodiment, the landing gear 20 includes a strut 22 rotatably coupled to an aircraft (not shown) about an axis 300 of the trunnion 26. A shock absorber 50 extends from an end of the strut 22 opposite the trunnion 26. The landing gear 20 also includes a drag link 40 rotatably coupled to the shock absorber 50 at a central portion about an axis 302, and one or more wheels 34 rotatably coupled to a first end 42 of the drag link about an axis 304. When the landing gear 20 is in the deployed position, and the aircraft is on the ground, the strut 22 extends in a downward direction from the aircraft, with the wheels contacting the ground to support at least a portion of the weight of the aircraft.

[0045] In the illustrated embodiment, a side brace 32 is provided that includes a first link 34 having a first end rotatably coupled to a first end of a second link 36. A second end of the first link 34 is pivotably coupled to a portion of the aircraft, and a second end of the second link 36 is pivotably coupled to the strut 22. As shown, when the landing gear 20 is in the deployed position, the side brace 32 prevents the strut 22 from rotating about the trunnion centerline 300 to maintain the landing gear in the deployed position. A foldable locking link 38 selectively locks the side brace 32 in an extended state to secure the landing gear 20 in the deployed position. To move the landing gear 20 to the stowed position, as shown, the locking link 38 is folded about a central axis, which unlocks the side brace 32, i.e., allows the first and second links 34, 36 of the side brace 32 to rotate relative to one another. Figures 1 to 3 Figure 4 and Figure 5

[0046] An actuator 30 is connected to the strut 22 to drive the strut 22, and thus the landing gear 20, between the deployed position and the stowed position. In the illustrated embodiment, the actuator 30 is a linear actuator that is rotatably coupled to the strut 22 such that extension of the actuator drives the landing gear 20 toward the stowed position, and retraction of the actuator drives the landing gear toward the deployed position.

[0047] ​​Embodiments of the shortening mechanism disclosed are described in relation to a typical cantilever landing gear; however, it should be understood that inclusion of the shortening mechanism is not limited to the illustrated landing gear. In this regard, the disclosed shortening mechanism can be included in any suitable landing gear, including landing gears having different actuators, linkage mechanisms, locations on the aircraft, numbers of wheels, or any other variations for which it is advantageous to shorten the landing gear as it moves from the deployed position to the stowed position.

[0048] Figures 6 to 8 An upper portion of the landing gear 20 is shown, which is configured to retract the shock absorber 50 into the strut as the landing gear moves from the deployed position Figure 6 and Figure 7 to the stowed position Figure 8 , thereby shortening the landing gear 20.

[0049] As Figure 6 best shown, the shock absorber 50 is disposed within a central portion of the strut 22 and is configured to slide translationally along a centerline 306 of the strut 22. In the illustrated embodiment, the shock absorber 50 includes a first element or piston 52 that is slidably disposed within a second element or cylinder 58. The second element 58 extends from a lower portion of the strut 22 (when the landing gear 20 is deployed) and the drag arm 40 (one or more wheels 28 are mounted to the drag arm) is coupled to an end of the second element. In this regard, the illustrated shock absorber 50 is configured to function in a manner that is generally known for telescoping shock absorbers used in landing gears.

[0050] The first element 52 includes a first annular protrusion 54 that extends radially outward from a first end to engage an inner wall of the strut 22, thereby guiding translation of the first element within the strut, as Figure 7 and Figure 8 shown. The first element 52 also includes a second annular protrusion 56 that extends radially outward and is disposed within the second element 58. The second element 58 includes an annular protrusion 60 that extends radially inward. When the shock absorber is in a fully extended position, engagement of the second annular protrusion 56 of the first element 52 with the annular protrusion 60 of the second element 58 holds a portion of the first element within the second element. As described below, this engagement also enables the first element 52 to retract the second element 58 into the strut 22 as the shortening mechanism moves the first element toward the trunnion 26.

[0051] Returning to Figure 6The landing gear 20 includes a linkage 70 that drives a shortening mechanism as the landing gear reciprocates between a retracted position and an extended position. The linkage 70 has a drive rod 72 pivotally connected at one end to a point 306 fixedly positioned about an axis 300 relative to the trunnion 26. A second end of the drive rod 72 is pivotally connected to an operating lever 74, which itself is rotatably connected to a strut 22 about an axis 310. The strut 22, operating lever 74, and drive rod 72 serve as part of a four-bar linkage such that when the actuator 30 rotates the strut 22 about the axis 300, the drive rod drives the operating lever 74 to rotate relative to the strut 22. Rotation of the operating lever 74 then drives the linkage 70 to retract the shock absorber 50 into the strut 22 and to rotate the trailing arm 40 to reposition one or more wheels 28 closer to the trunnion 26.

[0052] Now for reference Figure 7 and Figure 8 The operation of the first portion 80 of the linkage mechanism 70 retracting the shock absorber 50 into the strut 22 will be described. The first portion 80 of the linkage mechanism 70 includes a first link 82, which is fixedly connected at a first end to an operating lever 74, such that the first link rotates together with the operating lever when the landing gear 20 reciprocates between the deployed and retracted positions. The second end of the first link 82 is rotatably connected to the first end of a second link 84. The second link 84 is also rotatably connected to the first element 52 of the shock absorber 50.

[0053] When landing gear 20 is in Figure 7 In the extended position shown, the first element 52 of the shock absorber 50 is positioned such that the shock absorber is in the extended position relative to the strut 22. The strut 22 and the drive rod 72 are... Figures 1 to 3 The side strut 32 shown is locked in place, which in turn locks the positions of the first link 82, the second link 84, and the first element 52 of the shock absorber 50. Additionally, the ground load, which applies an upward axial force to the first element 52 of the shock absorber 50, reacts to the sidewall of the strut 22. More specifically, as... Figure 7 As shown, the upward force on the first element 52 of the shock absorber 50 tends to rotate the second link 84 clockwise, causing the engagement surface 86 formed on the second link 84 to contact the engagement surface 24 formed on the inner wall of the strut 22. Reacting the ground load onto the strut 22 instead of through the drive rod 72 allows for a lighter, more compact drive rod design.

[0054] When the landing gear 20 is facing Figure 8 When the retracted position is moved as shown, the drive lever 72 causes the operating lever 74 to rotate about the axis 310, causing the first connecting rod 82 to rotate clockwise about the axis 310, as shown. Figure 7 and Figure 8As shown. Clockwise rotation of the first link 82 raises the second link 84, which then... Figure 7 and Figure 8 The first link 82 rotates counterclockwise to disengage the engagement surface 86 of the second link from the engagement surface 24 of the strut 22. Clockwise rotation of the first link 82 also moves the second link 84, and thus moves the first element 52 of the shock absorber 50 toward the trunnion 26. As the first element 52 of the shock absorber 50 moves toward the trunnion 26, the second radial protrusion 56 of the first element engages the first radial protrusion 60 of the second element 58 to retract the second element into the strut 22. The retraction of the shock absorber 50 into the strut 22 moves the trailing arm 40 and one or more wheels 28 toward the trunnion 26 to shorten the landing gear 20.

[0055] When the landing gear 20 from Figure 8 The retractable position towards Figure 7 When the shock absorber 50 moves to the extended position, the movement of the linkage 70 reverses, causing the linkage to drive the shock absorber 50 to the extended position. More specifically, the operating lever 74 causes the first linkage 82 to rotate counterclockwise (e.g., ...). Figure 7 and Figure 8 (as shown) rotate to drive the shock absorber 50 (more specifically, the second element 58 of the shock absorber) to the extended position.

[0056] The illustrated embodiment shows a shock absorber 50 in which a first element 52 serves as a piston and a second element 58 serves as a cylinder, the piston being slidably arranged within the cylinder. Other embodiments are conceivable in which the second element 58 is slidably arranged within the first element 52. That is, embodiments are conceivable in which the cylinder of the shock absorber 50 is connected to a second connecting rod 84, and the piston of the shock absorber extends from the strut 22 and has a trailing arm 40 rotatably connected thereto.

[0057] Figure 9 and Figure 10 The lower portion of the landing gear 20 is shown, configured to move one or more wheels 28 toward the trunnion 26 to shorten the landing gear. More specifically, when the landing gear is in the deployed position ( Figure 9 Move to the collapsed position ( Figure 10 When the linkage mechanism 70 is in motion, the second part 90 causes the drag arm 40 to rotate clockwise (e.g., ...). Figure 9 and Figure 10 (As shown) rotate.

[0058] Now for reference Figure 9, the lower portion of the landing gear 20 is shown in the deployed position. The first end 42 of the drag arm 40, which mounts the one or more wheels 28, is in the lowered position. The second end 44 of the drag arm 40, which is in the raised position, is rotatably coupled about an axis 312 to a lowering link 92 first end. The second end of the lowering link 92 is rotatably coupled about an axis 314 to a positioning link 94, and the positioning link 94 is rotatably coupled about an axis 316 to a U-shaped bracket 98 extending laterally from the strut 22. A positioning rod 102 is pivotably coupled at one end to the positioning link 94. The second end of the positioning rod 102 is pivotably coupled to the operating rod 74 (see Figure 6 and Figure 7 ).

[0059] When the landing gear 20 is in the deployed position and the aircraft is on the ground, the ground exerts an upward force on the one or more wheels 28 that exerts a moment about the axis 302 that pushes the drag arm 40 in the clockwise direction (as shown by the arrow Figure 9 . This moment is reacted by the lowering link 92 as a tensile load in the lowering link that pulls down on the positioning link 94 at the axis 314. Because the axis 314 is positioned aft of the axis 316, i.e., between the axis 316 and the strut 22, the force exerted by the lowering link 92 on the positioning link tends to rotate the positioning link 94 about the axis 316 in the counterclockwise direction, as shown by the arrow Figure 9 , in the tensile state.

[0060] Still referring to Figure 9 , when the landing gear 20 is in the deployed position, the engagement surface 96 formed on the positioning link 94 engages the engagement surface 100 formed on the strut 22. Thus, most or all of the ground load applied to the wheels 28 is reacted into the strut 22 rather than the positioning rod 102.

[0061] When the landing gear 20 is moved from the deployed position shown by Figure 9 to the stowed position shown by Figure 10 , the drive rod 72 rotates the operating rod 74 about the axis 310, as previously described and as shown by the arrow Figures 6 to 8 . Rotation of the operating rod 74 drives the positioning rod 102 to rotate the positioning link 94 about the axis 316 in the clockwise direction, as shown by the arrows Figure 9 and Figure 10 . Rotation of the positioning link 94 drives the lowering link 92 to rotate the drag arm 40 about the axis 302 in the clockwise direction. This rotation moves the one or more wheels 28 toward the trunnion 26 to shorten the length of the landing gear 20 as it is moved toward the stowed position.

[0062] When the landing gear 20 is moved from the stowed position shown by Figure 10 to the deployed position shown by Figure 9As the illustrated deployed position moves, the drive rod 72 rotates the operating rod 74 in the opposite direction about the axis 310, thereby causing the positioning rod 102 to pull the positioning link 94 upward, causing the positioning link to rotate about the axis 34 in a counterclockwise direction until the engagement surface 96 of the positioning link 94 contacts the engagement surface 100 of the strut 22. This rotation causes the drop link 92 to pull the trailing arm 40 upward, causing the trailing arm to rotate the wheel 28 to the extended position.

[0063] The landing gear 20 described provides a shortening mechanism that retracts the shock absorber 50 into the strut 22 and also rotates the trailing arm 40 to move the wheel 28 toward the trunnion 26. These features are driven by the common link mechanism 70 and provide a shortening of the landing gear 20 that is greater than the shortening that either part of the mechanism (shock absorber retraction and trailing arm rotation) could provide alone.

[0064] Figure 11 And Figure 12 A second representative embodiment of a landing gear 120 is shown that uses an alternative link mechanism 70 to drive rotation of the trailing arm 40. Figure 11 And Figure 12 The landing gear 120 of Figures 1 to 9 the foregoing landing gear 20 is illustrated, except as described below. Components of the landing gear 120 that are similar to corresponding components of the landing gear 20 are labeled with the same reference numerals, and will not be described again in order to avoid repetition.

[0065] In the illustrated embodiment, rotation of the trailing arm 40 is not driven by a positioning rod coupled to the operating rod 74. Rather, a driver rod 122 is actuated by movement of the side brace 32 as the landing gear 120 reciprocates between the deployed position Figure 11 ) and the stowed position Figure 12 ). The driver rod 122 includes a first link 124 pivotably coupled to a second link 126. The first link 124 is coupled to the second link 36 of the side brace 32, and the second link 126 is pivotably coupled to the drop link 92.

[0066] As the landing gear 120 reciprocates between the deployed position and the stowed position, the side brace 32 moves between the extended position and the retracted position. This movement of the side brace 32 rotates the second link 36 of the side brace relative to the strut 22, and rotation of the second link of the side brace moves the driver rod 122 to drive the drop link 92, thereby rotating the trailing arm 40 and thus shortening the landing gear 120.

[0067] Figure 13 Another alternative representative embodiment of a landing gear 220 is shown that uses a rotary actuator 228 to drive rotation of the trailing arm 40. Figure 13 The landing gear 220 of Figures 1 to 9The foregoing landing gear 20 is shown, except as described below. Components of the landing gear 120 similar to corresponding components of the landing gear 20 are labeled with the same reference numerals, and will not be described again in order to avoid repetition.

[0068] In the illustrated embodiment, a rotary actuator 228 is mounted to the strut 22 or other suitable structure. The rotary actuator 228 drives a linkage 222 coupled to the drop link 92 to rotate the trailing arm 40. More specifically, a first link 224 of the linkage 222 is rotated by the actuator 228. A second link 226 is pivotably coupled at one end to the first link 226 and at a second end to the drop link 92. As the landing gear 220 reciprocates between the deployed position (Fig. 2) and the stowed position (not shown), the actuator 228 drives the linkage 222 to rotate the trailing arm 40, thereby lengthening and shortening the landing gear 220. Figure 11 ) with the stowed position (not shown), the actuator 228 drives the linkage 222 to rotate the trailing arm 40, thereby lengthening and shortening the landing gear 220.

[0069] This application can refer to quantities and numbers. Unless specifically stated, these quantities and numbers should not be considered limiting but rather as examples of possible quantities or numbers associated with this application. In this regard, this application can use the term "a plurality of" to refer to quantities or numbers. In this regard, the term "a plurality of" refers to any number more than one, such as two, three, four, five, etc. The terms "about," "approximately," "near," and the like mean plus or minus 5% of the stated value. For purposes of this application, the phrase "at least one of A, B, and C," means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C), including all other possible permutations when more than three elements are listed.

[0070] The principles, representative embodiments, and modes of operation of this application have been described in the foregoing description. However, the aspects of the application intended to be protected are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be considered in all respects as illustrative only and not restrictive in character. It should be understood that changes and modifications can be made by others and equivalents employed, without departing from the spirit of the application. It is expressly intended that all such changes, modifications and equivalents fall within the spirit and scope of the application as claimed.

Claims

1. A landing gear for a vehicle, comprising: The support is configured to reciprocate between a retracted position and an extended position; A shock absorber, comprising a first element slidably disposed within the strut and a second element slidably coupled to the first element; A tow arm, which is rotatably connected to the first element, and the first end of the tow arm has a wheel rotatably mounted thereto; A first linkage mechanism is connected to the second element, which drives the second element between a raised position when the support is in the retracted position and a lowered position when the support is in the extended position. An operating lever, which is connected to the first linkage mechanism; as well as A second linkage mechanism is connected to the tow arm and includes a positioning rod pivotally connected to the operating lever, wherein rotation of the operating lever drives the positioning rod to rotate the tow arm between a first tow arm position when the support is in the retracted position and a second tow arm position when the support is in the extended position.

2. The landing gear according to claim 1, wherein, The first linkage mechanism includes a first link rotatably connected at a first end to the support column and rotatably connected at a second end to the first end of a second link, the second link being connected at the second end to the first element.

3. The landing gear according to claim 2, wherein, The second link includes a second link engagement surface that contacts the inner surface of the strut when the strut is in the deployed position, wherein the axial load applied to the shock absorber drives the second link engagement surface toward the inner surface of the strut.

4. The landing gear according to claim 3, wherein, It also includes a drive rod, wherein the operating lever is fixedly coupled to the first link, and the drive rod has a first end pivotally coupled to the operating lever, wherein rotation of the drive rod causes the second link engagement surface to move away from the inner surface of the support when the support moves toward the retracted position.

5. The landing gear according to any one of claims 1 to 4, wherein, The support is rotatably connected about an axis, and the drive rod is pivotally connected about a point that is fixedly positioned relative to the axis.

6. The landing gear according to claim 5, wherein, The second linkage mechanism also includes: A positioning link, rotatably mounted to the support; and A lowering link, which is rotatably mounted at a first end to the positioning link and at a second end to the second end of the tow arm.

7. The landing gear according to claim 6, wherein, It also includes a support engagement surface formed on the support and a positioning link engagement surface formed on the positioning link, wherein when the support is in the deployed position, the support engagement surface engages the positioning link engagement surface.

8. The landing gear according to claim 7, wherein, When the support is in the deployed position, the tensile load applied to the lowering link pushes the positioning link engagement surface toward the support engagement surface.

9. The landing gear according to claim 8, wherein, The tensile load in the descending link reacts on the support through the contact between the positioning link engagement surface and the support engagement surface.

10. The landing gear according to claim 8, wherein, The tensile load in the descending link is generated by the vertical load applied to the wheel.

11. The landing gear according to claim 10, wherein, The first element is a piston, and the second element is a cylinder, with the piston partially disposed within the cylinder.

12. The landing gear according to claim 10, wherein, The first element is a cylinder, and the second element is a piston partially disposed within the cylinder.

13. A landing gear for a vehicle, comprising: The support is configured to reciprocate between a retracted position and an extended position; A shock absorber, comprising a first element slidably disposed within the strut and a second element slidably coupled to the first element; A tow arm, which is rotatably connected to the first element, and the first end of the tow arm has a wheel rotatably mounted thereto; A first linkage mechanism is connected to the second element, which drives the second element between a raised position when the support is in the retracted position and a lowered position when the support is in the extended position. A second linkage mechanism, connected to the trailing arm, allows the trailing arm to rotate between a first trailing arm position when the support column is in the retracted position and a second trailing arm position when the support column is in the extended position; and A side strut, connected at one end to the support column, wherein a first end of the second linkage mechanism is connected to the side strut, and a second end of the second linkage mechanism is connected to the tow arm, the movement of the side strut during the reciprocating motion of the landing gear between the deployed position and the retracted position causes the tow arm to rotate.

14. The landing gear according to claim 13, wherein, The second linkage mechanism includes: A positioning link, rotatably mounted to the support; and A lowering link, which is rotatably mounted at a first end to the positioning link and at a second end to the second end of the tow arm.

15. A landing gear for a vehicle, comprising: The support is configured to reciprocate between a retracted position and an extended position; A shock absorber, comprising a first element slidably disposed within the strut and a second element slidably coupled to the first element; A tow arm, which is rotatably connected to the first element, and the first end of the tow arm has a wheel rotatably mounted thereto; A first linkage mechanism is connected to the second element, which drives the second element between a raised position when the support is in the retracted position and a lowered position when the support is in the extended position. A second linkage mechanism is connected to the towing arm, which causes the towing arm to rotate between a first towing arm position when the support is in the retracted position and a second towing arm position when the support is in the extended position. as well as A rotary actuator, operably coupled to the second linkage mechanism and configured to rotate the tow arm as the landing gear reciprocates between the deployed and retracted positions.

16. The landing gear according to claim 15, wherein, The second linkage mechanism also includes: A positioning link, rotatably mounted to the support; and A lowering link, which is rotatably mounted at a first end to the positioning link and at a second end to the second end of the tow arm.

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