Abstract:
A fluid conduit joint includes a tube seal having a first bubble portion and a second bubble portion; a first tube adapter ( 40   a ); a second, tube adapter ( 40   b ); and a cover ( 50 ).The tube seal further includes a first hinge ( 60 ) and a second hinge ( 60 ). The first hinge ( 60 ) connects the first tube adapter ( 40   a ) to the cover ( 50 ), the first hinge ( 60 ) generally corresponding to the first bubble portion; the second hinge ( 60 ) connects the second tube adapter ( 40   b ) to the cover ( 50 ), the second hinge ( 60 ) generally corresponding to the second bubble portion; and the first hinge ( 60 ) and the second hinge ( 60 ) are axially spaced from each other.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/878,352, filed Sep. 16, 2013, which is hereby incorporated by reference as though fully set forth herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to joints, including joints configured to connect fluid ducts. 
       BACKGROUND 
       [0003]    Joints are often used to connect two or more portions of fluid ducts. Universal joints may permit two portions to be joined together with one or more degrees of freedom. 
         [0004]    SUMMARY 
         [0005]    An embodiment of the present disclosure includes a joint including a tube seal including first and second bubble portions, first and second tube adapters, a cover, a first set of hinges connecting the first tube adapter to the cover, the first set of hinges generally corresponding to the first bubble portion, and a second set of hinges connecting the second tube adapter to the cover, the second set of hinges generally corresponding to the second bubble portion. 
         [0006]    An embodiment of the present disclosure includes an aircraft air duct double hinge joint, including a double bubble tube seal, a cover, first and second tube adapters, a first set of hinges axially spaced from a second set of hinges, the first set of hinges connecting the first tube adapter to the cover, the second set of hinges connecting the second tube adapter to the cover. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1A  is a side view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0008]      FIG. 1B  is a cross-sectional view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0009]      FIG. 1C  is a side view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0010]      FIG. 1D  is a cross-sectional view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0011]      FIG. 2A  is a cross-sectional view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0012]      FIG. 2B  is a side view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0013]      FIG. 2C  is a side view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0014]      FIG. 2D  is a partial cross-sectional view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0015]      FIG. 2E  is a perspective view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0016]      FIG. 2F  is a perspective view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0017]      FIG. 3  is a partial cross-sectional view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0018]      FIG. 4  is a side view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0019]      FIGS. 5A-5D  generally illustrate hinge axis configurations of embodiments of joints in accordance with teachings of embodiments of the present disclosure. 
           [0020]      FIG. 6A  is a cross-sectional view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0021]      FIGS. 6B and 6C  are side views generally illustrating portions of a joint in accordance with teachings of embodiments of the present disclosure. 
           [0022]      FIGS. 6D  is a cross-sectional view generally illustrating portions of a joint in accordance with teachings of embodiments of the present disclosure. 
           [0023]      FIGS. 6E and 7  are partial cross-sectional views generally illustrating portions of joints in accordance with teachings of embodiments of the present disclosure. 
           [0024]      FIG. 8  is a perspective view generally illustrating portions of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0025]      FIG. 9A  generally illustrates a hinge axis configuration of a joint in accordance with teachings of an embodiment of the present disclosure. 
           [0026]      FIG. 9B  generally illustrates a hinge axis configuration of a joint in accordance with teachings of an embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    Reference will now be made in detail to embodiments of the present disclosure, examples of which are described herein and illustrated in the accompanying drawings. While the invention will be described in conjunction with embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by appended claims. 
         [0028]    As generally illustrated in  FIGS. 1A-4 , embodiments of a joint  20  may include a seal  30 , one or more adapters (e.g.,  40 A,  40 B), a cover  50 , and/or one or more pins  60 . Joint  20  may be configured to connect a first section  18 A of fluid conduit  18  and a second section  18 B of fluid conduit  18 . Fluid conduit  18  may be configured as a fluid duct and/or a high temperature aircraft air duct, and may be referred to herein as duct  18 . Duct  18  may be configured to convey fluid, such as, for example, bleed air from an aircraft engine. Duct  18  may comprise one or more of a variety of materials, such as, without limitation, titanium. 
         [0029]    In embodiments, joint  20  may be configured with one or more angulation centers  22 . Angulation centers  22  may be referred to herein in the singular as a hinge axis, and in the plural as hinge axes  22 . Hinge axes  22  may permit first and/or second sections  18 A,  18 B of duct  18  to pivot in at least one direction. In embodiments, joint  20  may include two hinge axes  22 A,  22 B that may be arranged generally perpendicular to the longitudinal axis  24  of joint  20 . With reference to  FIG. 1A , it is noted that hinge axis  22 B would actually be running perpendicular to the page. The hinge axes  22 A,  22 B may be axially spaced/separated from each other by axial separation  22 C, which may correspond to joint  20  comprising a double hinge joint. Axial separation  22 C may allow joint  20  to have a reduced overall diameter  26  and/or length  28  relative to conventional joints in which hinges axes are typically all coplanar (e.g., not axially separated) and overlap in the radial direction and/or the circumferential direction. Joint  20  may also include a reduced weight relative to convention joints, which may correspond to a reduced overall diameter and/or length. Such axial separation may also permit hinge axes (e.g.,  22 A,  22 B) to be aligned parallel to each other and/or at any angle in between. 
         [0030]    In embodiments, joint  20  may include a seal  30 . Seal  30  may be configured as a tube seal and seal  30  may be referred to herein as tube seal  30 . Tube seal  30  may be generally cylindrical and may include a neck portion  32  and/or one or more extending portions. The extending portions, which may be referred to herein as bubble portions (e.g., first bubble portion  34 A and second bubble portion  34 B), may be disposed at or about opposite axial ends of neck portion  32 . Bubble portions  34 A,  34 B may be located at or near distal ends of tube seal  30  and may correspond to portions of tube seal  30  that include larger and/or smaller diameters than neck portion  32 . For example, bubble portions  34 A,  34 B may correspond to portions of tube seal  30  in which the diameter of tube seal  30  gradually increases to a maximum diameter  36 A and then decreases to a minimum diameter  36 B, which may result in a generally curved and/or bubbled configuration. In embodiments, bubble portions  34 A,  34 B may include maximum diameters greater than a maximum diameter of neck portion  32  and/or may include minimum diameters less than the minimum diameter of neck portion  32 . Tube seal  30  may act as a primary enabler and the bubble portions  34 A,  34 B may correspond to (e.g., the centers of bubble portions  34 A,  34 B may be generally aligned with) hinge axes  22 A,  22 B. Tube seal  30  may be configured to allow fluid to be transported through it. In embodiments, tube seal  30  may include one or more materials, such as, for example only, an iron-based metal. 
         [0031]    In embodiments, joint  20  may include a first adapter  40 A and a second adapter  40 B that may be configured as tube adapters and/or fluid conduit adapters. In embodiments, first and second adapters  40 A,  40 B may be configured for connection to end portions  18 C of first and/or second sections  18 A,  18 B of fluid conduit  18 . Tube adapters  40 A,  40 B may include a variety of sizes, shapes, and/or configurations. First and second tube adapters  40 A,  40 B may be substantially similar to each other or may be different from each other. For example, and without limitation tube adapters  40 A,  40 B may include generally the same shape and/or maximum diameter. 
         [0032]    In embodiments, tube adapters  40 A,  40 B may be configured for connection with and/or may be connected to end portions  18 C in a variety of ways, including, but not limited to, welding. In embodiments, it may be desirable for tube adapters  40 A,  40 B to comprise one or more materials that may be compatible with the material of duct  18 . For example, and without limitation, duct  18  and tube adapters  40 A,  40 B may comprise titanium. Tube adapters  40 A,  40 B may include a generally cylindrical shape and may include first portions  42 A,  42 B and/or second portions  44 A,  44 B. Tube adapter first portions  42 A,  42 B may include diameters that are larger than the diameter of duct  18  and tube adapter first portions  42 A,  42 B may be configured to be arranged at least partially around duct  18 . Additionally or alternatively, first portions  42 A,  42 B may include diameters that are smaller than the diameter of duct  18  and tube adapter first portions  42 A,  42 B may be configured to be arranged at least partially within duct  18 . In embodiments, first portions  42 A,  42 B may include diameters that are substantially the same as the diameter of duct  18 . In embodiments, tube adapters  40 A,  40 B may comprise one or more materials and/or may generally comprise the same or similar material as duct  18 . 
         [0033]    As generally illustrated in  FIGS. 1A-1D , tube adapters  40 A,  40 B may include second portions  44 A,  44 B. Second portions  44 A,  44 B may be disposed axially inward of first portions  42 A,  42 B. Tube adapter second portions  44 A,  44 B may include diameters that are larger than the minimum and/or maximum diameters  36 A,  36 B of tube seal  30 . Tube adapter second portions  44 A,  44 B may be configured to be arranged at least partially around tube seal  30 . Tube adapter second portions  44 A,  44 B may be configured to be arranged at least partially around at least one of first and second bubble portions  34 A,  34 B of tube seal  30 . In embodiments, second portions  44 A,  44 B may correspond to (e.g., be generally aligned with) first and second bubble portions  34 A,  34 B. For example, and without limitation, second portions  44 A,  44 B may extend axially at least to the center of first and second bubble portions  34 A,  34 B, which may include extending axially beyond the centers of first and second bubble portions  34 A,  34 B (e.g., toward neck  32 ). In embodiments, tube adapter second portions  44 A,  44 B may include diameters that are smaller than a diameter of cover  50 . In embodiments, as generally illustrated in  FIG. 1B , second portions  44 A,  44 B may be configured to contact the tube seal  30 . Tube adapters  40 A,  40 B may be configured to slide relative to tube seal  30 , which may accommodate pivotal movement of tube adapters  40 A,  40 B about hinge axes  22 A,  22 B. In embodiments, tube adapters  40 A,  40 B may be axially separated from each other, which may include not overlapping in the radial direction and/or the circumferential direction (e.g., relative to longitudinal axis  24  of joint  20 ). 
         [0034]    As generally illustrated in  FIGS. 1A-1D and 3 , tube adapters (e.g., first and second tube adapters  40 A,  40 B) may include inner portions  46 A,  46 B Inner portions  46 A,  46 B may be configured to contact tube seal  30  Inner portions  46 A,  46 B and tube seal  30  may be configured to move relative to each other. Movement of inner portions  46 A,  46 B and tube seal  30  relative to each other may include a sliding movement. For example, and without limitation, inner portions  46 A,  46 B may include curved portions (e.g., curved portions  46 C,  46 D) that may correspond to bubble portions of tube seal  30  (e.g., bubble portion  34 A and/or  34 B). Contact between inner portions  46 A,  46 B and tube seal  30  may include a fluid sealing arrangement. In embodiments, inner portions  46 A,  46 B may be connected to tube seal independently of welding inner portions  46 A,  46 B and/or any portion of tube adapters  40 A,  40 B to tube seal  30 . In embodiments, tube adapters  40 A,  40 B may include outer portions  48 A,  48 B, respectively, that may be disposed radially outward of inner portions  46 A,  46 B. Outer portions  48 A,  48 B may be configured for connection with cover  50 , which may comprise including apertures (e.g., apertures  48 C 1 ,  48 C 2 ,  48 C 3 ,  48 C 4 ). Outer portion apertures  48 C 1 ,  48 C 2 ,  48 C 3 ,  48 C 4  may be configured to receive at least a portion of a pin  60  and/or at least a portion of a retainer  68  (e.g., a generally illustrated in  FIGS. 1B and 1D ). 
         [0035]    In embodiments, such as generally illustrated in  FIGS. 2A-2D , joint  20  may include one or more bearing sleeves (e.g., bearing sleeves  56 A,  56 B) that may be disposed between tube adapters  40 A,  40 B and tube seal  30 . For example, and without limitation, bearing sleeve  56 A may be disposed between second portion  44 A of tube adapter  40 A and first bubble portion  34 A of tube seal  30 , and/or bearing sleeve  56 B may be disposed between second portion  44 B of tube adapter  40 B and second bubble portion  34 B of tube seal  30 . Bearing sleeves  56 A,  56 B may be configured as a wear element and/or may reduce wear that may be caused by contact between tube adapters  40 A,  40 B and tube seal  30 . For example, and without limitation, bearing sleeves  56 A,  56 B may include carbon, a cobalt alloy, and/or other materials. Bearing sleeves  56 A,  56 B may include a generally cylindrical shape and/or may extend partially and/or entirely about the circumference of tube seal  30 . Bearing sleeves  56 A,  56 B may or may not be configured substantially the same as each other, which may comprise including generally the same shape (e.g., may be interchangeable) and/or maximum diameter. In embodiments, bearing sleeves  56 A,  56 B may be press fit into tube adapters  40 A,  40 B, respectively. Joint  20  may include one or more retaining elements (e.g., retaining elements  58 A,  58 B) that may be configured to hold and/or help hold bearing sleeves  56 A,  56 B in place relative to tube adapters  40 A,  40 B. Retaining elements  58 A,  58 B may include a generally ring-like shape. 
         [0036]    In embodiments, joint  20  may include a cover  50 . Cover  50  may be configured as a cover and/or a gimbal ring, and may be referred to herein as cover  50  and/or gimbal ring  50 . Cover  50  may be configured to connect first and second tube adapters  40 A,  40 B to each other. Cover  50  may include one or more sizes, shapes, and/or configurations, which may comprise including a generally cylindrical shape. Cover  50  may include a generally uniform diameter that may be larger than the maximum diameter of second portions  44 A,  44 B of tube adapters  40 A,  40 B and may be disposed around all of tube seal  30  (e.g., may include a greater diameter than tube seal  30  and a greater length than tube seal  30 ). Cover  50  may be configured to be disposed at least partially around the second portions  44 A,  44 B of tube adapters  40 A,  40 B. As generally illustrated in  FIGS. 2A, 2D, 3, and 4 , cover  50  may include one or more apertures  52  and apertures  52  may correspond to one or more pins  60 . In embodiments, cover  50  may include a recess  50 A that may extend circumferentially all or part of the way around cover  50 . Recess  50 A may reduce the weight of joint  20  by reducing the amount of material used for cover  50 . In embodiments, cover  50  may comprise one or more materials, such as, for example only, aluminum and/or titanium. 
         [0037]    In embodiments, joint  20  may include one or more pins  60 . Pins  60  may include one or more of a variety of sizes, shapes, and/or configurations. In embodiments, pins  60  may include a head portion  62 , a neck portion  64 , and/or a connecting portion  66 . Head portion  62  may include a diameter that is larger than the diameter of apertures  52 , which may allow head portion  62  to limit the extent to which pins  60  can extend into and/or through apertures  52 . As generally illustrated in  FIGS. 2E and 2F , head portion  62  may include one or more attachment/securing features, such as apertures/recesses  62 A. Apertures/recesses  62 A may be configured for welding pin  60  to cover  50 . In embodiments, an aperture/recess  62 A may comprise a generally hemispherical recess that may reduce the diameter of head portion  62  in some areas (e.g., see  FIG. 2F ). In embodiments, cover  50  may include one or more flat areas  50 B that may correspond to head portions  62  and/or may allow the underside of head portions  62  to be disposed generally flat against cover  50 . 
         [0038]    In embodiments, neck portion  64  may include a diameter that is smaller than the diameter of head portion  62  and/or smaller than the diameter of apertures  52 , and/or at least as large or larger than connection portion  66 . A length of neck portion  64  may correspond to a thickness of cover  50 . Neck portion  64  may be threaded along all or part of its length, and/or may correspond to threads of apertures  52  of cover  50 . Connecting portions  66  may be configured for connection with tube adapters  40 A,  40 B, which may be retainer  68 . For example, and without limitation, connection portions  66  may be threaded to correspond to threads of retainer  68 . In embodiments, as described in greater detail below in connection with  FIGS. 6A-7 , connecting portions  66  may be configured for connection and/or engagement with a retaining ring  70 . 
         [0039]    In embodiments, pins  60  may be disposed at one or more of a variety of positions, which may include positions along the outer circumference of cover  50 . Joint  20  may include one or more pins  60 . For example, and without limitation, joint  20  may include a first set of two pins (e.g., pins  60 A,  60 B) associated with first tube adapter  40 A and a second set of two pins (e.g., pins  60 C,  60 D) associated with second tube adapter  40 B. As generally illustrated in  FIGS. 1A and 2C , pins  60  in each set may be arranged on opposite sides of joint  20  (e.g., separated by about 180 degrees). 
         [0040]    In embodiments, pins  60  may be configured to connect first and second tube adapters  40 A,  40 B (e.g., second portions  44 A,  44 B and/or outer portions  48 A,  48 B) to cover  50 . Pins  60  may connect first and second tube adapters  40 A,  40 B to cover  50  in such a way as to create a secondary seal, which may help keep fluid flowing through joint  20  from leaking out and/or help keep external foreign materials out of joint  20 . First and second tube adapters  40 A,  40 B may be arranged relative to cover  50  in such a way that puts pins  60  in shear loading with reduced and/or minimal pin bending load. 
         [0041]    Joint  20  may include one or more plates  54 , which may include weld doubler plates, that may be arranged between one or more of pins  60  and cover  50 . Plates  54  may facilitate connecting and/or securing pins  60  relative to cover  50 . In embodiments including plates  54 , the length of neck portion  64  may generally correspond to the combined thickness of cover  50  and the plates  54 . 
         [0042]    In embodiments, pins  60  may axially retain first and second tube adapters  40 A,  40 B relative to cover  50  and/or relative to each other. Pins  60  may be configured as one or more hinges and/or may define one or more hinge axes  22 . For example, pins  60 A and  60 B may be configured as a first hinge and may define first hinge axis  22 A. Pins  60 A and  60 B may permit first tube adapter  40 A to pivot in at least a first plane, which may be perpendicular to hinge axis  22 A. Pins  60 C and  60 D may be configured as a second hinge and may be define a second hinge axis  22 B. Pins  60 C and  60 D may permit second tube adapter  40 B to pivot in at least a second plane, which may be perpendicular to second hinge axis  22 B. In embodiments, a plurality of pins may be connected together in a single body. 
         [0043]    Pins  60  may be configured to restrict rotational and/or torsional movement of the tube adapters  40 A,  40 B relative to cover  50  and/or tube seal  30 . For example, as generally illustrated in  FIGS. 1B, 1D, 2A, 2D, 3, and 4  one or more of pins  60  may extend through cover  50  into and/or through tube adapters  40 A,  40 B (e.g., through one or more of apertures  48 C 1 ,  48 C 2 ,  48 C 3 ,  48 C 4 ). Pins (e.g., pin  60 E) may extend through cover  50 , through aperture  48 C 1 , and into a retainer  68 , which may include a nut configured to be connected to pin  60 E (e.g., at or about connecting portion  66 ). Pins  60  may be connected to a retainer  68  in a variety of ways, which may include, for example, a threaded engagement. Retainer  68  may be at least partially disposed between the inner and outer portions of tube adapter (e.g., inner portion  46 B and outer portion  48 B). 
         [0044]    As generally illustrated in  FIGS. 4-5D , axial separation  22 C of hinges axes  22  may permit a variety of configurations of hinge axes  22 . In a first configuration, as generally illustrated in  FIGS. 4 and 5A , hinge axes  22  may be arranged generally perpendicular relative to each other. In a second configuration, as generally illustrated in  FIG. 5B , hinge axes  22  may be parallel to each other. The second configuration may provide the greatest amount of flexibility in a particular plane, but may provide limited flexibility in some and/or all other planes. In a third configuration, as generally illustrated in  FIGS. 5C and 5D , hinge axes  22  may be arranged in a skewed/oblique configuration (e.g., not parallel or perpendicular). The third configuration may be desirable for situations in which a greater degree of flexibility is desired in one plane (e.g., greater than the flexibility provided by the first configuration), and some flexibility is still desired in a second plane (e.g., which may not be available in the second configuration). 
         [0045]    As generally illustrated in  FIGS. 6A-7 , in embodiments, pins  60  may extend though cover  50  into a retaining ring  70 . Retaining ring  70  may be arranged between cover  50  and a tube adapter (e.g., tube adapter  40 A and/or tube adapter  40 B). Retaining ring  70  may be configured to restrict axial movement of cover  50  and a tube adapter (e.g.,  40 A and/or  40 B) relative to each other in at least one direction (e.g., direction  78 B) and/or may be configured to permit at least some rotational and/or torsional movement (e.g., about longitudinal axis  24 ) of cover  50  and a tube adapter relative to each other. For example, and without limitation, retaining ring  70  may be configured to slide relative to a tube adapter (e.g., tube adapter  40 B). Torsional and/or rotational freedom may help compensate for manufacturing tolerances. In embodiments, tube adapter  40 A and/or tube adapter  40 B may be configured to rotate at least 360 degrees related to cover  50 . 
         [0046]    In embodiments, retaining ring  70  may include a generally cylindrical shape and may include one or more recesses  72 . A recess  72  be configured as a radial recess (e.g., may reduce the radial length of retaining ring  70  in at least some areas) and may extend partially or entirely around the circumference of retaining ring  70 . In embodiments, retaining ring  70  may include a plurality of recesses  72  spaced around the circumference of retaining ring  70 . Recesses  72  may correspond to (e.g., include an axial width at least as great as or greater than) connecting portion  66  of a pin (e.g., pin  60 F and/or  60 G) and/or may be configured to at least partially receive a pin  60 . Pins  60  may be configured to be connected to and/or engaged with retaining ring (e.g., disposed at least partially in recess  72  and/or engaged in a threaded engagement). In embodiments, recesses  72  may be configured as an aperture extending all of the way through retaining ring  70  and/or pins  60  may be configured to extend all of the way through recesses  72 . In embodiments, joint  20  may include a first tube adapter (e.g., tube adapter  40 A) that may be rotationally fixed relative to cover  50  and/or may include a second tube adapter (e.g., tube adapter  40 B) that may be configured to for at least some rotational and/or torsional movement relative to cover  50 . In embodiments, tube adapters  40 A,  40 B may be configured for at least some rotational/torsional movement relative to cover  50 . 
         [0047]    Retaining ring  70  may be configured to permit the position of the tube adapters  40 A,  40 B to be variable. For example, pins  60 F and  60 G may extend through cover  50  into recesses  72 A,  72 B and pins  60 F and  60 G may be configured to be at least partially received within recesses  72 A,  72 B. A retaining ring  70  may be configured to move and/or slide relative to a tube adapter (e.g., tube adapter  40 B) and/or may permit the tube adapter to rotate. In embodiments, retaining ring  70  may be fixed to a tube adapter (e.g., first tube adapter  40 A) and pins  60  may be permitted to slide in a circumferential direction in recess  72 . 
         [0048]    In embodiments, retaining ring  70  may be configured to restrict axial movement of a tube adapter in a direction (e.g., direction  78 B) and/or may be configured not to restrict axial movement of a tube adapter in a second direction (e.g., direction  78 A). Tube adapter second portions  44 A,  44 B may include one or more retaining portions (e.g., retaining portions  44 C,  44 D) that may facilitate retaining ring  70  restricting axial movement of a tube adapter. For example, and without limitation, retaining portion  44 C may be configured to at least partially restrict axial movement of tube adapter  40 B in direction  78 B and/or retaining portion  44 D may be configured to at least partially restrict axial movement of tube adapter  40 B in direction  78 A. Retaining portions  44 C,  44 D may be integrally formed with a tube adapter and/or may be connected to a tube adapter in one or more of a variety of ways, including, for example, welding. In embodiments, retaining portion  44 D may be connected to a tube adapter (e.g., first tube adapter  40 A) after the tube adapter has been disposed/assembled relative to cover  50  and/or retaining ring  70 . 
         [0049]    In embodiments, joint  20  may be configured to selectively rotationally fix a tube adapter (e.g., tube adapter  40 A) relative to cover  50 . For example, joint  20  may include a lock  80 . Lock  80  may include a generally pin-like shape and may be connected to a tube adapter and/or retaining ring  70 . Lock  80  may be configured to be moved to engage and/or disengage the tube adapter and/or retaining ring  70 . In embodiments, one or more of pins  60  may be configured as a locking mechanism (e.g., may include a greater length, may include threaded portions, and/or may be configured to selectively move in a radial direction), for example as generally illustrated in connection with element  80 . 
         [0050]    As generally illustrated in  FIG. 8 , an outer appearance of joint  20  may be substantially similar regardless of whether joint includes a retaining ring  70 . 
         [0051]    As generally illustrated in  FIGS. 9A and 9B , axial separation of hinge axes  22  of joint  20  may reduce the moment arm length  92  to the hinge axes of joint  20 . For example, as shown in  FIG. 9A , conventional joints with coplanar hinge axes  98  (e.g., without axial separation  22 C) include a relatively long moment arm  90 . In contrast, as generally illustrated in  FIG. 9B , embodiments of joint  20  according to the present disclosure may include a relatively short moment arm  92 . A reduced moment arm length may reduce cantilever loads on equipment attached to first and/or second duct sections  18 A,  18 B. The equipment may include engine ports, precoolers, valves, and/or any other desired equipment. Axial separation  22 C of hinge axes  22  may also prevent the need for the “ear” configuration  94  generally illustrated in  FIG. 9A . In an “ear” configuration  94 , a joint may include left and right sections  94 A,  94 B that each include axially, radially, and/or circumferentially overlapping “ears” that extend radially outward and are fastened to a common gimbal ring  96 . 
         [0052]    In embodiments, joint  20  may comprise one or more materials. In embodiments, joint  20  may be independent of and/or not include any weldments and/or may be assembled without welding. For example, joint  20  may be assembled without welding tube seal  30  with tube adapters  40 A,  40 B. In embodiments, the only weldments or welding used in joint  20  may be to secure pins  60  to cover  50 . 
         [0053]    The foregoing descriptions of specific embodiments of the present disclosure have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and various modifications and variations are possible in light of the above teaching. It should be understood that the present disclosure is not limited to the examples and/or embodiments described herein. For example, references to a single element are not so limited and may include one or more of such element. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.