The present disclosure relates generally to maintenance stands, and more particularly to portable maintenance stands for use with aircraft engines, such as vertically oriented aircraft engines.
Typically, aircraft maintenance stands fall into three categories: phase maintenance stands for depot-level maintenance, daily maintenance stands, and multi-application work stands. The type of required maintenance dictates the type of work platform required, and the level of skill that a mechanic must have to accomplish the designated task and to do so according to prescribed safety standards.
It is known in the aviation industry that aviation mechanics maintain aircraft airframe and structural components, flight surfaces, as well as maintaining hydraulic and pneumatic controls and actuating systems and mechanisms. The mechanics may also service landing gear systems, perform engine maintenance, air conditioning, pressurization, visual improvement, oxygen and other utility systems, egress systems, including seat and canopy ejection systems and components. Such detailed work requires facilitated access to the airplane component, which often rest at a high elevation. This work must be done in a safe and efficient manner.
Mechanics need to be able to service the aircraft from a work platform reaching elevated regions of the aircraft. Suitable, safe and efficient platforms for work on some types of vehicles are lacking in the art. A work platform which can be configured to be positioned in proximity to, for example, an airplane component, yet maintain a buffer to prevent bumping into the airplane component, is desirable and necessary to prevent damage to the aircraft. The work platform provides access to any tools, liquids, equipment, communication devices, and publications the mechanic may need, as well as access to the portion of the airplane which needs to be inspected and/or maintained.
In view of the foregoing, opportunities exist for improvements in maintenance platforms, particularly for certain types of aircraft with unique wing and engine configurations.
One aspect of the present disclosure relates to a portable aircraft maintenance stand that includes a frame assembly and a deck. The frame assembly has a base portion and an upper portion. The deck is mounted to the upper portion of the frame assembly and includes a cantilevered portion. The deck also has a gap configured to receive an engine of an aircraft such that the deck at least partially wraps around the engine. The cantilevered portion of the deck is configured to be positioned vertically above a wing of the aircraft, wherein the engine is mounted to the wing, while the base portion of the frame assembly is positioned vertically below the wing.
The upper portion of the frame assembly may be vertically adjustable relative to the base portion. The frame assembly may include first and second stair sections, at least one of the stair sections being automatically adjustable in response to the upper portion being adjusted vertically relative to the base portion. The frame assembly may further include a screw jack assembly operable to vertically adjust the upper portion relative to the base portion. The screw jack assembly may include at least four screw jacks that are linked together and operably concurrently using a single rotation input. The stand may also include a handrail assembly mounted to the deck, and the handrail assembly may include at least one height adjustable section. The handrail assembly may include at least one width adjustable member. The handrail assembly may include at least one removable section, such as a removable gate. The deck may include a plurality of deck sliders, and at least some of the deck sliders may be adjustable into and out of the gap to adjust a size of the gap. The engine may include a vertically oriented nacelle and a plurality of horizontally oriented rotor blades, and the deck may be positioned vertically below the rotor blades. The frame assembly may have a maximum width of less than about 15 feet and a maximum length of less than about 20 feet. The deck may be adjustable in height between about 15 feet and about 20 feet.
Another aspect of the present disclosure relates to a method of operating a portable maintenance stand relative to an aircraft. The aircraft has a wing and an engine mounted to the wing. The method includes providing a portable aircraft maintenance stand having a frame assembly and a deck. The deck is mounted to the frame assembly and has a gap. The method also includes positioning the stand adjacent to the aircraft with a portion of the deck positioned vertically higher than a top surface of the wing and a portion of the engine positioned in the gap.
The engine may include a vertically oriented nacelle and a plurality of horizontally oriented rotor blades, and the nacelle may be positioned in the gap while the deck is positioned vertically below the rotor blades. The deck may include a plurality of deck sliders, and the method may further include adjusting at least some of the deck sliders into and out of the gap to reduce a space between the deck and the engine within the gap. The frame assembly may include a base portion and an upper portion, the deck may be mounted to the upper portion, and the method may further include vertically adjusting the upper portion relative to the base portion to adjust a height of the deck relative to the aircraft. The frame assembly may include at least one flight of stairs, and the method may include automatically changing a pitch of the stairs when the upper portion is vertically adjusted relative to the base portion. The stand may further include a handrail assembly mounted to the deck, and the method may further include adjusting or removing a portion of the handrail assembly prior to and after positioning the portion of the engine in the gap.
Another aspect of the present disclosure relates to a portable aircraft maintenance stand that includes a horizontally oriented deck, a handrail assembly extending around a perimeter of the deck, a frame assembly supporting the deck, and at least one flight of stairs providing access to the deck. The deck is configured to at least partially extend around a nacelle of an engine of an aircraft and extend between a horizontally oriented rotor blade of the engine and a top surface of a wing of the aircraft. The frame assembly may be operable to vertically adjust a height of the deck.
The accompanying drawings and figures illustrate a number of exemplary embodiments and are part of the specification. Together with the present description, these drawings demonstrate and explain various principles of this disclosure. A further understanding of the nature and advantages of the present invention may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label.
While the embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the forms disclosed. Rather, the instant disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims.
Maintenance stands are well known for purposes related to maintaining and repairing aircraft and other vehicles. Maintenance stands can be used for a variety of purposes, such as holding equipment and positioning workers in close proximity to the portion of the aircraft or other vehicle of interest.
Some types of aircraft, in particular, pose challenges related to maintenance because of the size, shape and/or location of portions of the aircraft that are being addressed by workers. Such is the case with the V-22 aircraft, which includes two propeller engines. A unique feature of the V-22 aircraft is that the engines can be rotated through a 90 degree angle to arrange the rotor blades either vertically to optimize forward movement of the aircraft, or horizontally to optimize vertical movement of the aircraft. When the V-22 aircraft is in a rest position on the ground, the engines automatically revert to a rest state in which the nacelle of the engine is arranged vertically and the rotor blades are arranged horizontally and at a location vertically at the top end of the engine. Further, the rotor blades may rotate to a predetermined rotated position when the engine is turned off with one rotor blade arranged in parallel with a length dimension of the fuselage of the aircraft and the other two arranged at an angle relative to the length dimension of the fuselage. When in this rest state, the rotor blades are positioned at least 20 feet above the ground and much of the engine that requires maintenance is positioned at least 10 feet above the ground and more typically in the range of 12 feet to 20 feet above the ground surface. The extreme height of the rotor blades and other portions of the engine as well as the vertically oriented nacelle and the horizontally oriented rotor blades pose significant challenges associated with accessing and performing maintenance and other tasks associated with the engines of a V-22 aircraft.
The present disclosure is directed to a maintenance stand, and in particular a maintenance stand that is portable and that provides a useful working environment for addressing maintenance and other tasks associated with a vehicle such as an aircraft. The stand may be positioned on or constructed to include a plurality of wheels, rollers or other devices that make it possible to more easily position the stand relative to the vehicle. In some embodiments, the stand may include a tow bar or other feature that makes it possible to more easily move the stand relative to the vehicle.
The stand may include a deck that provides a working surface upon which a plurality of workers may stand. The deck may be elevated relative to a ground surface on which the stand is supported. In at least some embodiments, the stand may include height adjustable features that move the deck up and down relative to the ground surface and the vehicle. The deck may be cantilevered from a frame structure that supports the deck. The cantilevered portion of the deck may make it possible to position the deck between various features of the vehicle such as, for example, over the top of a wing of an aircraft, between a nacelle and one or more rotor blades of an engine, or between an upper surface of a wing and one or more rotor blades or a nacelle of an engine of an aircraft.
The stand may also include one or more flights of stairs that facilitate access of the deck. At least one of the flights of stairs may be automatically adjustable (e.g., in pitch) to account for height adjustments of the deck. The stair treads of the one or more flights of stairs may remain parallel to a supporting ground surface during the automatic adjustment.
The stand may also include a handrail assembly. A portion of the handrail assembly may extend around an outer perimeter of the deck. Portions of the handrail assembly may also extend around the flights of stairs and associated landings for the flights of stairs. Some portions of the handrail assembly may be adjustable in height. Other portions of the handrail assembly may be temporarily removable. Still other portions of the handrail assembly may be horizontally adjustable. The handrail assembly may include gate structures that are pivotal between open and close positions. Some portions of the handrail assembly may include (e.g., covered by) protective or shock absorbing features such as rubber, foam, or the like to limit the risk of damage to the vehicle in the event that the handrail assembly contacts portions of the vehicle being worked on.
Another aspect of the disclosed stand relates to a gap or cutout in the deck. This gap may be sized to receive a portion of the vehicle being worked on such as, for example, a portion of a nacelle of an aircraft engine. The gap feature may facilitate the deck wrapping around a portion of the vehicle such as a vertically oriented nacelle of the V-22 aircraft. The deck may include a plurality of deck slider members that move into and out of the gap while the portion of the vehicle is positioned in the gap. The sliders may reduce the space between the deck and that portion of the vehicle positioned in the gap to provide an extension of the standing surface of the deck for the workers. The sliders may improve safety and/or provide an improved stability in and around the portion of the vehicle positioned with the gap. The sliders may include (e.g., covered by) protective or shock absorbing features (e.g., bumpers or the like) such as rubber, foam, or the like, particularly along surfaces of the sliders that may contact the vehicle, to limit the risk of damage to the vehicle in the event that the sliders contact portions of the vehicle being worked on. The sliders may also include positive stop features that limit the amount of movement of the sliders into or out of the gap, such as no further than half way across the width of the gap. Some of the sliders may include notched out portions to accommodate portions of the deck handrail assembly in some positions for the sliders.
In use, the stand may be adjusted into a preliminary or delivery state in which features of a stand are arranged and configured to permit moving the stand into a working position relative to the vehicle. Once the stand is in the working position, some features of the stand may be adjusted such that the stand is optimized for use during any work performed on the vehicle by workers using the stand. For example, portions of the handrail assembly may be lowered or removed when the stand is in the delivery position, and later adjusted into raised positions or other working orientations once the stand is in the working position (e.g., to accommodate the position of rotor blades for the V-22 aircraft). Further, the stand may be adjusted vertically once in the working position to position the deck at a more optimized position for the workers to perform certain tasks relative to various features of the vehicle.
Referring now to
Referring now to
The base portion 20 includes a horizontal frame 30, a first vertical frame 32, a stair platform 34, platform rails 36, and a plurality of rollers 38 mounted to the horizontal frame 30. The base portion 20 may also include a platform gate 39 and have a width W1 and a length L1 (see
The width W1 typically is in the range of about 10 feet to about 20 feet, and more particularly in the range of about 12 feet to about 16 feet. The width W1 is typically less than about 15 feet. The length L1 is typically in the range of about 10 feet to about 25 feet, and more particularly in the range of about 15 feet to about 20 feet. The length L1 is typically less than about 20 feet. The width W1 and length L1 may be selected based on a number of criteria including, for example, the dimensions and weight of the deck 14, how the deck 14 is mounted to the frame assembly (e.g., cantilevered as shown in
The upper portion 22 of the frame assembly 12 includes a second vertical frame 40 and braces 42 that support the deck 14. The braces 42 are arranged to assist in holding the deck 14 in a cantilevered orientation relative to the base portion 20 of the frame assembly 12. The braces 42 may be arranged at an angle (e.g., an angle of about 30 degrees to 60 degrees relative to a vertical plane). The braces 42 may extend from the second vertical frames 40 to the deck 14 (e.g., along a bottom side of the deck 14) as shown in
In some embodiments, portions of the base portion 20, upper portion 22 (such as the braces 42), and deck 14 may include bumpers or other shock absorbing material along portions that may contact the vehicle during us.
The second vertical frame 40 may be mounted to the first vertical frame 32 of the base portion 20 with a sliding interface. For example, the vertical members of the second vertical frame 40 may include hollow beams with a rectangular cross-sectional shape having a first cross-sectional area. The first vertical frame 32 may include a plurality of vertical beams with a matching rectangular cross-sectional shape having a second cross-sectional area that is smaller than the first cross-sectional area to facilitate insertion therein.
The stair assembly 24 includes first and second flights of stairs 50, 52, first stair rails 60, and second stair rails 62 (see
The stair assembly 24 is configured to fit within a footprint of the base portion 20 of the frame assembly 12. That is, the stair assembly 24, at least in some embodiments, may remain within a length L1 and width W1 of the base portion 20, particularly during use of the stand 10 with a vehicle.
The first stair rails 60 are mounted to the first flight of stairs 50 and the second stair rails 62 are mounted to the second flight of stairs 52. The second stair rails 62 are also pivotally connected at their upper end to the deck handrail assembly 16 at a plurality of pivot connections 66. A lower end of the second stair rails 62 are pivotally connected to the second flight of stairs 52 at a plurality of pivot connections 68.
The height H1 typically is in the range of about 10 feet to about 20 feet, and more particularly in the range of about 15 feet to about 16 feet. The height H1 may be at least 15 feet. The height H2 typically is in the range of about 15 feet to about 24 feet, and more particularly in the range of about 16 feet to about 20. In some embodiments, the height H1 may be no greater than about 20 feet. In one example, the deck 14 has a height of about 16 feet 8 inches±1 foot. In other examples, regardless of the minimum or maximum height, the stand may provide a range of height adjustment for the deck 14 of about 6 inches to about 6 feet, and more particularly about 1 foot to about 3 feet.
The lift assembly 26 includes a plurality of screw jacks 70, a plurality of vertical links 72, a plurality of horizontal links 74, a plurality of gear boxes 76, and an input transfer box 78 having a rotation input adapter 79 (see
Although screw jacks are illustrated in the figures for use in moving the base and upper portions 20, 22 relative to each other, thereby adjusting a height of deck 14, other types of vertical adjustment features may be used to perform a similar function. The use of screw jacks interconnected with a plurality of links and gear boxes may be particularly useful for providing a coordinated vertical adjustment, especially when dealing with the relatively heavy features and cantilevered deck 14 of the stand 10. However, other types of lift mechanisms may be used including, for example, hydraulic jacks and the like.
Referring now to
The platform surface 82 defines a work surface upon which workers can stand while performing tasks associated with the vehicle. The platform surface 82 may be increased in size using the plurality of deck sliders 86. The deck sliders 86 may be positioned within the support structure 80 underneath the platform surface 82. The deck sliders 86 may be individually adjustable into and out of the gap 84 as shown in, for example,
The gap 84 has a length L2 extending rearward from the front edge 88 towards the rear edge 90. The width W2 is measured in a direction between the right and left side edges 92, 94. The length L2 typically is in the range of about 4 feet to about 10 feet, and more particularly about 5 feet to about 8 feet. In one embodiment, the length L2 is about 7 feet. The width W2 typically is in the range of about 4 feet to about 8 feet, and more particularly about 5 feet to about 7 feet. In one embodiment, the length W2 is about 6 feet. Deck 14 may have a generally rectangular shape. The length L3 of the deck 14 typically is in the range of about 10 feet to about 15 feet, and more particularly about 12 feet to about 14 feet. In one embodiment, the length L3 is about 13 feet. The width W3 of the deck 14 typically is in the range of about 10 feet to about 15 feet, and more particularly about 12 feet to about 14 feet. In one embodiment, the length W3 is about 13 feet. The shape and size of the deck 14 and gap 84 may adjusted to accommodate different sizes and shapes of vehicles and or vehicle parts for which the stand 10 is being used.
The deck handrail assembly 16 is mounted to the deck 14 around the front and rear edges 88, 90 and the right and left side edges 92, 94 as well as along a perimeter of the stair landing 96. As described above, a portion of the deck handrail assembly 16 may be removable, such as in the area of the gap 84 along the front edge 88 for purposes of, for example, positioning the stand 10 into close proximity to the vehicle (i.e., moving a portion of the vehicle into the gap 84).
In other arrangements, the deck 14 may be supported around its entire periphery by the frame assembly 12 rather than being cantilevered from a portion of the frame assembly 12 as shown in the figures. In such an arrangement, only portions of the frame assembly 12 positioned vertically below the gap 84 may be removed or reduced in size in order to permit insertion of the portion of the vehicle into the gap and any portion of the vehicle that extends below the gap would not interfere with the frame assembly in a vertical direction within the footprint of the gap 84.
The deck handrail assembly 16 includes a plurality of fixed rails 100, a plurality of height adjustable rails 102, a plurality of horizontal adjustable rails 104, at least one removable gate 106, and at least one swinging gate 108 (see
The height adjustable rails 102 may be adjusted vertically up or down, such as to be positioned at a same height of the fixed rails 102 when in a raised position as shown in
The removable gate 106 may be removed prior to moving the stand 10 into a working position adjacent to the vehicle such as when the engine is positioned within the gap 84 as shown in
The swinging gate 108 may be used to control access to the deck 14 and/or the stair assembly 24 at or near the stair assembly 24. Other types of gates or egress devices may be used to provide access to the stair assembly 24 and/or to the working area of deck 14.
At least some of the rails of deck handrail assembly 16 may include a pad, bumper, or other feature 109 (see
The deck handrail assembly 16 may provide an OSHA compliant handrail with a 42 inch top rail and a 21 inch mid rail. The height adjustable rails 102 may be reduced to a minimal height of about 15 inches to about 20 inches above the platform surface 82 of the deck 14. In some embodiments, the height adjustable rails 102 may be adjustable to a plurality of different heights between a fully collapsed position (see
The deck handrail assembly 16 may be customized for use with different types of vehicles such as other types of aircraft with different dimensions, orientations for the nacelle and rotor blades of the motor.
The stand 10 may comprise different types of materials having various properties, such as strength, durability, rigidity, wear resistance, shock absorption, and the like to provided optimized performance, cost and other benefits associated with stand 10. In one embodiment, the stand 10 comprises primarily metal materials, but may in other embodiments include polymer, composite or other non-metal materials. In one example, the stand 10 has a weight in the range of about 5,000 pounds to about 8,000 pounds, and more particularly about 5,800 pounds to about 6,400 pounds, such as for the stand 10 described above with reference to
In the embodiment shown in
The arrangement of the deck 14 relative to the wing and rotor blades shown in
The stand 10 may also include a repositioning tool 132 (see
The stand 10 may also include a tow bar 134 (see
The dimensions, shapes, sizes, adjustability features, and the like may be customized, altered or otherwise changed in order to accommodate use with different shapes, sizes and types of vehicles. Such modifications are within the spirit and scope of the present disclosure.
Unless otherwise explained, any technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the. The singular terms “a”, “an”, and “the” include plural referents unless the context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described herein. The term “comprises” means “includes.” All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety for all purposes. The materials, methods, and examples are illustrative only and not intended to be limiting.
In the specification, reference may be made to the spatial relationships between various components and to the spatial orientation of various aspects of components as the devices are depicted in the attached drawings. However, as will be recognized by those skilled in the art after a complete reading of the present application, the devices, members, apparatuses, etc. described herein may be positioned in any desired orientation. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” or other like terms to describe a spatial relationship between various components or to describe the spatial orientation of aspects of such components should be understood to describe a relative relationship between the components or a spatial orientation of aspects of such components, respectively, as the device described herein may be oriented in any desired direction.
For purposes of this disclosure, the term “aligned” means parallel, substantially parallel, or forming an angle of less than 35.0 degrees. For purposes of this disclosure, the term “transverse” means perpendicular, substantially perpendicular, or forming an angle between 55.0 and 125.0 degrees. Also, for purposes of this disclosure, the term “length” means the longest dimension of an object. Also, for purposes of this disclosure, the term “width” means the dimension of an object from side to side. Often, the width of an object is transverse the object's length.
Various inventions have been described herein with reference to certain specific embodiments and examples. However, they will be recognized by those skilled in the art that many variations are possible without departing from the scope and spirit of the inventions disclosed herein, in that those inventions set forth in the claims below are intended to cover all variations and modifications of the inventions disclosed without departing from the spirit of the inventions. The terms “including:” and “having” come as used in the specification and claims shall have the same meaning as the term “comprising.”
This application claims the benefit of the filing date of U.S. Provisional Application No. 62/810,465, filed on 26 Feb. 2019, and entitled ADJUSTABLE AIRCRAFT MAINTENANCE STAND, the disclosure of which is incorporated in its entirety by this reference.
Number | Date | Country | |
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62810465 | Feb 2019 | US |