TRAPEZOIDAL PANEL PIN JOINT ALLOWING FREE DEFLECTION BETWEEN FUSELAGE AND WING
The invention is directed a trapezoidal panel pin joint for allowing deflection of an aircraft between a fuselage section and a wing section, wherein the pin joint comprises a vertical pin portion, a lug portion, and a clevis portion; wherein at least one vertical flexible tee member is positioned below the pin joint; and wherein the pin joint is coupled to at least two horizontal flexible tee members, such that the pin joint and vertical and horizontal flexible tee members, in combination, release two rotational degrees of freedom.
1) Field of the Invention
The invention relates to a pin joint in an aircraft fuselage. More particularly, the invention relates to a trapezoidal panel pin joint allowing free deflection between the fuselage and the wing of an aircraft.
2) Description of Related Art
In aircraft, large deflections between the wing and the fuselage due to wing bending can cause design and durability problems in the fuselage and fuselage to wing attachment structure. Known aircraft have wing to fuselage attachment structure that have accounted for this differential deflection by separating the top of the wing box and the fuselage with a horizontal flexible tee member. Known aircraft have a trapezoidal panel that is an extension of the wing rib at the wing/fuselage joint. Known trapezoidal panel designs have accounted for the differential deflection between the wing and the fuselage/fixed pressure deck by vertically separating the trapezoidal panel and fixed pressure deck, allowing the fuselage skin panel and frames to deflect over a relatively long vertical distance. Thus, wing deflection is absorbed by bending of the fuselage frames and skin panels above the trapezoidal panel. Known metallic fuselage designs use stiffened fuselage panels and physical separation to enable the deflection that occurs at the wing rear main spar. However, such known designs can have less vertical distance to incur the large wing deflections, and this can induce stresses to the wing and fuselage. This can increase the risk of durability of the parts, can require more structure, and can increase the weight of the aircraft. In addition, known designs only release one rotational degree of freedom.
Accordingly, there is a need for an improved pin joint design in an aircraft fuselage that does not have the problems associated with known designs.
SUMMARY OF THE INVENTIONThe invention satisfies this need for an improved pin joint design in an aircraft fuselage. None of the known pin joint designs provides all of the numerous advantages of the invention. Unlike known designs, the design of the invention provides the following advantages: the trapezoidal panel pin joint design reduces significant weight and significant risk of durability issues in service; the trapezoidal panel pin joint design alleviates the induced stresses by allowing free rotation at the upper surface of the wing aft spar by use of a vertically oriented pin and vertical and horizontal flexible tee members allowing an added degree of freedom, and thus, the design of the invention releases two rotational degrees of freedom; the trapezoidal panel pin joint design allows a high deflection in a localized area and then uses flexible attachments a short distance away from the flexible joint; the trapezoidal panel pin joint and flexible tee members reduce induced loading from wing bending and allow the overwing joint to flex with wing deflection and fuselage pressurization; the trapezoidal panel pin joint design allows a trapezoidal panel to be able to handle wing deflections without inducing high loads into the joint; the trapezoidal panel pin joint design allows the fixed pressure deck and floor beams to be located in close proximity to the wing upper surface on a composite or metal aircraft without inducing high deflections or point loads into the aircraft fuselage, and thus enables efficient space utilization by locating the fixed pressure deck and wing upper surface in close proximity to each other; and, the trapezoidal panel pin joint design allows weight and space saving within the composite structure architecture of an aircraft.
The invention provides for a trapezoidal panel pin joint to allow deflection of an aircraft between a fuselage section and a wing section, wherein the pin joint comprises a vertical pin portion, a lug portion, and a clevis portion; wherein at least one vertical flexible tee member is positioned below the pin joint; and wherein the pin joint is coupled to at least two horizontal flexible tee members, such that the pin joint and vertical and horizontal flexible tee members, in combination, release two rotational degrees of freedom. Preferably, the vertical flexible tee member has a vertical flexible rebate within the member, and the horizontal flexible tee member has a horizontal flexible rebate within the member. The pin joint allows a trapezoidal panel of the fuselage section to be able to handle deflections in the wing section without inducing high loads into the joint. In another aspect of the invention, the invention provides for a flexible fuselage point to enable deflection of an aircraft without high strain comprising a panel pin joint and flexible tee members that, in combination, release two degrees of freedom.
The foregoing and other advantages and features of the invention, and the manner in which the same are accomplished, will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings which illustrate preferred and exemplary embodiments, but which are not necessarily drawn to scale, wherein:
The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, this invention may be embodied in several different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
Referring now to the drawings, and in particular, to
The invention allows for a high deflection in a localized area and uses vertical and horizontal flexible tee members 26, 40, respectively, a short distance away from the flexible joint. Preferably, the distance is at least two inches or greater. This eliminates the need for a separation between the fixed pressure deck 46 and floor beams 44 of the aircraft and the wing upper surface at the rear spar and eliminates the use of large fittings and thick panels to force the fuselage to conform to the wing deflections. The trapezoidal panel and the fixed pressure deck are in line in the same horizontal plane. This invention allows the wing rear spar to be located in close proximity to the fixed pressure deck and floor beams on a composite or metal aircraft without inducing high deflections or point loads into the aircraft fuselage. In the design of the invention, the top of the trapezoidal panel and the pressure deck are virtually coincidental requiring the trapezoidal panel itself to absorb the deflection and incur large deflection induced stress. The pin joint design of the invention alleviates the induced stresses by allowing free rotation at the upper surface of the wing rear spar by use of the vertically oriented pin and vertical flexible tee members which allow an added degree of freedom or rotation. Thus, the invention allows two rotational degrees of freedom. The pin joint and vertical flexible tee member release a first degree of freedom, and the horizontal flexible tee members release a second degree of freedom. The increased degree of freedom is a vertical rotation. The released vertical degree of freedom means that the pin joint increases the ability of the fuselage and wing to rotate without inducing a moment into the joint. The invention allows the overwing joint to flex with wing deflection and fuselage pressurization, in conjunction with the vertical degree of rotation. This invention enables weight and space saving within the aircraft composite or metal structure architecture. The design of the pin joint of the invention has the advantages of reducing significant weight and reducing significant risk of durability issues in service.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims
1. A trapezoidal panel pin joint for allowing deflection of an aircraft between a fuselage section and a wing section, the pin joint comprising a vertical pin portion, a lug portion, and a clevis portion, and the pin joint is positioned at a wing rear spar of the aircraft; and at least one vertical flexible tee member is positioned below the pin joint; and the pin joint is coupled to at least two horizontal flexible tee members, such that the pin joint and vertical flexible tee member allow for vertical rotation at the wing rear spar, and such that the horizontal flexible tee members allow for horizontal rotation at a wing/fuselage joint.
2. (canceled)
3. The pin joint of claim 1 wherein the pin joint and the vertical flexible tee member connect the wing rear spar to a trapezoidal panel.
4. The pin joint of claim 3 wherein the vertical flexible tee member absorbs deflections at a top end and a bottom end of the trapezoidal panel.
5. The pin joint of claim 1 wherein the vertical flexible tee member has a vertical flexible rabbet.
6. The pin joint of claim 1 wherein each of the horizontal flexible tee members has a horizontal flexible rabbet.
7. The pin joint of claim 1 wherein the horizontal flexible tee member separates the fuselage section and a top portion of the wing section.
8. The pin joint of claim 1 wherein the number of vertical flexible tee members is two.
9. The pin joint of claim 1 wherein the horizontal flexible tee members are positioned on each side of the pin joint opposite one another.
10. The pin joint of claim 1 wherein the pin joint allows a trapezoidal panel of the fuselage section to be able to handle deflections in the wing section without inducing high loads into the wing/fuselage joint.
11. The pin joint of claim 10 wherein the trapezoidal panel and a fixed pressure deck are in line in a horizontal plane.
12. A flexible fuselage point to enable deflection of an aircraft without high strain comprising a panel pin joint and flexible tee members that, in combination, allow a wing/fuselage joint to rotate with wing deflection and fuselage pressurization, in conjunction with a vertical degree of rotation at a wing rear spar.
13. The flexible fuselage point of claim 12 wherein the panel pin joint comprises a vertical pin portion, a lug portion, and a clevis portion.
14. The flexible fuselage point of claim 12 wherein the flexible tee members comprise at least one vertical flexible tee member and at least two horizontal flexible tee members.
15. The flexible fuselage point of claim 14 wherein the vertical flexible tee member has a vertical flexible rabbet, and wherein each horizontal flexible tee member has a horizontal flexible rabbet.
16. The flexible fuselage point of claim 12 wherein the pin joint allows a trapezoidal panel of a fuselage section of the aircraft to be able to handle deflections in a wing section without inducing high loads into the wing/fuselage joint.
17. A trapezoidal panel pin joint for allowing deflection between a fuselage section and a wing section of an aircraft, the pin joint comprising a vertical pin portion, a lug portion, and a clevis portion, and the pin joint is positioned at a wing rear spar of the aircraft; and at least one vertical flexible tee member having a vertical flexible rabbet is positioned below the pin joint, and along with the pin joint, connects a trapezoidal panel in the fuselage section to the wing rear spar; and in the pin joint is coupled to at least two horizontal flexible tee members each having a horizontal flexible rebate rabbet, such that the pin joint and the vertical flexible tee member allow for vertical rotation at the wing rear spar, and such that the horizontal flexible tee members allow for horizontal rotation at a wing/fuselage joint.
18. The pin joint of claim 17 wherein the pin joint allows the trapezoidal panel in the fuselage section to be able to handle deflections in the wing section without inducing high loads into the wing/fuselage joint.
19. The pin joint of claim 17 wherein the vertical pin portion is oriented vertically to the lug portion and the clevis portion.
20. The pin joint of claim 17 wherein the trapezoidal panel and a fixed pressure deck are in line in a horizontal plane.
Type: Application
Filed: Sep 15, 2006
Publication Date: Jul 9, 2009
Inventors: Patricia W. Estell (Woodinville, WA), John H. Polk (Carnation, WA)
Application Number: 11/522,018
International Classification: B64C 1/00 (20060101);