Abstract:
A clip for assembling corners of hollow members such as the rails and stiles of an extruded aluminum door. The clip has an L shape and may feature a double L shape. A portion inserts into the hollow of a first member and is attached thereto. Another portion extends into the other hollow member for attachment thereto to form a sturdy joint without welding. Pairs of clips may be used at each corner.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation of application Ser. No. 14/032,722, filed Sep. 20, 2013, entitled Manufacture and Method For Forming Structures and the Structures Resulting Therefrom, which application is incorporated by reference herein in its entirety. 
     
    
     FIELD 
       [0002]    The present invention relates to joinery methods and manufactures for assembling structures and more particularly, to such methods and manufactures applied to the task of assembling structures, such as doors, windows and frames, from members conjoined at an angle, e.g., perpendicular to one another. 
       BACKGROUND 
       [0003]    Various manufactures and methods are known for joining adjacent members, such as welding, mortise and tenon joints, the use of threaded fasteners extending through the adjacent ends of the members, etc. As applied to metal structures, such as metal doors, traditional welding methods of the stiles to the rails is labor and skill intensive, costly, and often causes discoloration and distortion of pre-finished members. The use of full-width tie rods in conjunction with corner fittings requires multiple fittings and assembly is time consuming and costly. Improved and/or alternative methods and devices for joinery therefore remain desirable. 
       SUMMARY 
       [0004]    The disclosed subject matter relates to a structure having a first member with an interior hollow and a slot aperture in a side thereof communicating with the interior hollow; a second member having an interior hollow and an open end, the open end communicating with the interior hollow thereof; a clip for attaching the first member to the second member, the clip having a first leg, a second leg, a third leg and a fourth leg, the first leg and second leg being conjoined at a first angle forming a first conjunction and the third leg being attached to the first leg at an end thereof distal to the second leg forming a second conjunction, the third leg extending along the first leg proximate and substantially parallel to a surface thereof distal to the second leg and in a direction toward the first conjunction, the fourth leg extending from a third conjunction with the third leg distal to the second conjunction, the fourth leg extending parallel to the second leg along a portion of the length of the second leg proximate the first conjunction, the first leg and the third leg being inserted into the slot aperture in the first member and the clip rotated into a position with the first leg contacting the first member within the interior hollow and being fastened to the first member, the second leg extending outside the interior hollow, inserting into the open end of the second member and being fastened to the second member. 
         [0005]    In another embodiment, the first, second, third and fourth legs are each formed from a continuous metal strip. 
         [0006]    In another embodiment, a retainer extends from a side surface of the second leg proximate the first conjunction, a width of the second leg including the retainer exceeding the width of the slot aperture, such that the retainer is capable of preventing the clip from passing through the slot aperture into the interior hollow of the first member. 
         [0007]    In another embodiment, the clip has a plurality of fastener apertures formed therein and the first member and the second member each have a fastener aperture therein, the plurality of fastener apertures of the clip and the apertures in the first member and the second member being aligned in an assembly orientation, and further including a plurality of fasteners inserted through the aligned fastener apertures of the clip and the first and second members to fasten the first and second members to the clip. 
         [0008]    In another embodiment, the width of the clip at the first conjunction, the second conjunction and the third conjunction is relieved. 
         [0009]    In another embodiment, the third conjunction abuts the first conjunction, supporting the first conjunction. 
         [0010]    In another embodiment, the length of the fourth leg is such that an end of the fourth leg distal to the third leg is approximately flush with an exterior surface of the first member when the clip is fastened thereto. 
         [0011]    In another embodiment, a combined thickness of the first leg and the third leg approximates a height of the slot aperture in the first member. 
         [0012]    In another embodiment, the first member has two slot apertures spaced a predetermined distance from one another and the clip is a first clip and further including a second clip like the first clip for attaching the first member to the second member, the first slot aperture receiving the first clip and the second slot aperture receiving the second clip, the second leg of the first clip and the second leg of the second clip inserting into the hollow of the second member and being fastened to the second member. 
         [0013]    In another embodiment, the second member is tubular having a generally rectangular cross-sectional shape with pairs of opposed walls, the second leg of the first clip being fastened to a first wall of a pair of opposed walls and the second leg of the second clip being attached to a second of the pair of opposed walls. 
         [0014]    In another embodiment, the first and second members are tubular extrusions of aluminum alloy. 
         [0015]    In another embodiment, the structure is a door. 
         [0016]    In another embodiment, the plurality of fasteners are bind fasteners. 
         [0000]    In another embodiment, the plurality of blind fasteners are rivets. 
         [0017]    In another embodiment, a structure has a first member with an interior hollow and a slot aperture in a side thereof communicating with the interior hollow; a second member having an interior hollow and an open end, the open end communicating with the interior hollow thereof; a clip attaching the first member to the second member, the clip having a first leg and a second leg conjoined at an angle of approximately 90 degrees defining an angular conjunction, the first leg and the second leg being monolithic, a retainer extending from a side surface of the second leg proximate the angular conjunction, a width of the second leg including the retainer exceeding the width of the slot aperture, such that the retainer prevents the clip from falling through the slot aperture into the interior hollow of the first member, the first leg and the second leg each having a fastener aperture formed therein and the first member and the second member each have a fastener aperture therein, the fastener apertures of the clip and the apertures in the first member and the second member being aligned in an assembly orientation, and further including a plurality of fasteners inserted through the aligned fastener apertures of the clip and the first and second members to fasten the first and second members to the clip, the first leg being inserted into the slot in the first member and the clip being rotated into a position with the first leg contacting the first member within the interior hollow, and being fastened to the first member, the second leg extending outside the interior hollow, inserting into the open end of the second member and being fastened to the second member. 
         [0018]    In another embodiment, a third leg attached to the first leg at an end thereof distal to the second leg forming a second conjunction, the third leg extending along the first leg proximate and substantially parallel to a surface thereof distal to the second leg and in a direction toward the angular conjunction, the third leg being inserted with the first leg into the slot aperture in the first member. 
         [0019]    In another embodiment, a fourth leg attached to an end of the third leg forming a third conjunction distal to the second conjunction, the fourth leg extending from the third conjunction parallel to the second leg along a portion of the length of the second leg proximate the first conjunction, such that an end of the fourth leg distal to the third leg is approximately flush with an exterior surface of the first member when the clip is fastened thereto, the first, second, third and fourth legs each being part of a continuous metal strip. 
         [0020]    In another embodiment, a combined thickness of the second leg and the fourth leg approximates a height of the slot aperture in the first member and the width of the clip at the angular conjunction, the second conjunction and the third conjunction is relieved. 
         [0021]    In another embodiment, the first member has two slot apertures spaced a predetermined distance from one another and the clip is a first clip and further including a second clip like the first clip for attaching the first member to the second member, the first slot aperture receiving the first clip and the second slot aperture receiving the second clip, the second leg of the first clip and the second leg of the second clip inserting into the hollow of the second member and being fastened to the second member. 
         [0022]    In another embodiment, the second member is tubular having a generally rectangular cross-sectional shape with pairs of opposed walls, the second leg of the first clip being fastened to a first wall of a pair of opposed walls and the second leg of the second clip being attached to a second of the pair of opposed walls, wherein the first and second members are tubular extrusions of aluminum alloy, the fasteners are rivets and the structure is a door. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    For a more complete understanding of the present disclosure, reference is made to the following detailed description of exemplary embodiments considered in conjunction with the accompanying drawings. 
           [0024]      FIG. 1  is perspective view of a clip for assembling members in accordance with an embodiment of the present disclosure. 
           [0025]      FIG. 2  is a perspective view of the clip of  FIG. 1  looking from another direction. 
           [0026]      FIG. 3  is a perspective view of the clip of  FIGS. 1 and 2  in position for insertion into a first hollow member. 
           [0027]      FIG. 4  is a partially phantom perspective view of the clip of  FIG. 3  positioned within the first hollow member. 
           [0028]      FIG. 5  is a perspective view of the clip and hollow member of  FIGS. 3 and 4  coupled to an adjacent member to form an assembly. 
           [0029]      FIG. 6  is a cross-sectional view of the assembly of  FIG. 5 . 
           [0030]      FIG. 7  is a perspective view of the cross-section of the assembly of  FIG. 6 . 
           [0031]      FIG. 8  is a perspective view of the assembly of  FIGS. 5-7  viewed from another direction. 
           [0032]      FIG. 9  is perspective view of a clip for assembling members in accordance with another embodiment of the present disclosure. 
           [0033]      FIG. 10  is a perspective view of the clip of  FIG. 9  looking from another direction. 
           [0034]      FIG. 11  is a partially phantom, perspective view of the clip of  FIGS. 9 and 10  in a first insertion position into a slot in a first hollow member. 
           [0035]      FIG. 12  is a partially phantom, perspective view of the clip of  FIG. 11  as it is rotated into a second insertion position within the first hollow member. 
           [0036]      FIG. 13  is a partially phantom perspective view of the clip of  FIGS. 11 and 12  in the second insertion position within the first hollow member. 
           [0037]      FIG. 14  is a perspective view of the clip and hollow member of  FIG. 13  coupled to an adjacent member to form an assembly. 
           [0038]      FIG. 15  is a cross-sectional view of the assembly of  FIG. 14 . 
           [0039]      FIG. 16  is a perspective view of the cross-section of the assembly of  FIG. 15 . 
           [0040]      FIG. 17  is perspective view of a clip for assembling members in accordance with another embodiment of the present disclosure. 
           [0041]      FIG. 18  is a perspective view of the clip of  FIG. 17  looking from another direction. 
           [0042]      FIG. 19  is a perspective view of the clip of  FIGS. 17 and 18  in position for insertion into a first hollow member. 
           [0043]      FIG. 20  is a partially phantom, perspective view of the clip of  FIG. 19  positioned within the first hollow member. 
           [0044]      FIG. 21  is a perspective view of the clip and hollow member of  FIG. 20  coupled to an adjacent member to form an assembly. 
           [0045]      FIG. 22  is a cross-sectional view of the assembly of  FIG. 21 . 
           [0046]      FIG. 23  is a perspective view of the cross-section of the assembly of  FIG. 22 . 
           [0047]      FIG. 24  is perspective view of a clip for assembling members in accordance with another embodiment of the present disclosure. 
           [0048]      FIG. 25  is a perspective view of the clip of  FIG. 24  looking from another direction. 
           [0049]      FIG. 26  is a partially phantom, perspective view of a pair of clips shown in  FIGS. 24 and 25  in a first insertion position into a pair of slots in a first hollow member. 
           [0050]      FIG. 27  is a partially phantom, perspective view of the clips of  FIG. 26  as they are rotated into a second insertion position within the first hollow member. 
           [0051]      FIG. 28  is a partially phantom perspective view of the clips of  FIGS. 26 and 27  in the second insertion position within the first hollow member. 
           [0052]      FIG. 29  is a perspective view of the clips and hollow member of  FIG. 28  coupled to an adjacent member to form an assembly. 
           [0053]      FIG. 30  is a cross-sectional view of the assembly of  FIG. 29 . 
           [0054]      FIG. 31  is a perspective view of the cross-section of the assembly of  FIG. 30 . 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0055]    The present disclosure describes a clip and clip installation process that may be used in conjunction with fasteners to assemble a frame joint from component members. In one embodiment, the clip may be used to join a stile and rail of a door or window frame, e.g., made from hollow members, such as extrusions made from aluminum alloy. The clip may be used to align vertical and horizontal components relative to each other, allowing them to be joined at the proper angle. The clip may be used to join members of various lengths, such as tall/short top and bottom rails, allowing a variety of structures to be assembled using a common clip, e.g., to produce a variety of frames of different dimensions. The clip may be made from plastic, aluminum or steel depending on the strength needed for the joint connection. In those applications where high strength, low cost and formability are required, steel can be used. Progressive, one-piece steel stamping designs are presented herein, but fabricated steel, machined aluminum, machined plastic, extruded or cast aluminum and extruded or cast plastics could also be used for forming the clip. The present disclosure includes clip installation methods that could be categorized as: inside mounting, outside mounting or slide-in mounting. In one embodiment, the clip may be attached to the members to be joined through the use of blind fasteners. The fastener dimensions may be selected to provide the required strength for the application and may be set using a hydraulic or pneumatic gun, eliminating welding and the inherent heat related problems that it creates. Other types of fasteners can be used for attachment, such as screws, bolts, rivets, spot welds, etc. Typically, the use of the clip and methods of the present disclosure allow a reduction in the number of parts required to join members into a frame structure over conventional approaches. The avoidance of welding may also lead to reductions in labor costs and required skill levels, assembly time, number of parts to assemble and stock, manufacturing costs, rework and scrap. The ease of assembly provided by the clip may also allow assembly to take place in the field versus in the factory. 
         [0056]      FIGS. 1 and 2  show a clip  10  for assembling members  11 ,  13  (see  FIG. 5 ) in accordance with an embodiment of the present disclosure. The clip  10  could be described as having a stacked or double L configuration with a first leg  12  having a first panel  14 , an offset  16  and a second panel  18 . A second leg  20  extends at an angle, e.g., 90 degrees from the first panel  14 , defining the bottom portion of a first L shape and a third panel  22  depends from a reverse curve  24 , such that the third panel  22  extends parallel to the second panel  18  and in line with the first panel  14 . The offset  16  has dimensions approximating the thickness of the third panel  22  and permits the third panel  22  to be in line with the first panel  14 . A third leg  26  extends from the third panel  22  at an angle, e.g., 90 degrees, forming in conjunction with the third panel  22 , another L shape that nests (with a space between second leg  20  and third leg  26 ) with the L shape formed by the first leg  12  and the second leg  20 . The second leg  20  has a flattened U shaped cross-section with a central area  20 C, bends  20 B and flat portions  20 F that overall provide a stiffening function and may mate in complementary fashion with interior surfaces of the member  13 . A pair of support wings  28  extend from opposite sides of the first panel  14  with a connected portion  28 C extending at an angle, e.g., 90 degrees relative to the first panel  14  to a bend  28 B of, e.g., 90 degrees from which extends a lip  28 L. A similar pair of support wings  30  with portions  30 C,  30 B and  30 L extend in a similar manner from third panel  22 . Holes  32 A 1 - 32 E permit the passage of fasteners (not shown) like rivets, screws, bolts, etc. through the clip  10 . 
         [0057]      FIGS. 3 and 4  show the installation of the clip  10  into a hollow structural member  11  that may be made, e.g., from extruded aluminum or plastic. The member  11  has a wall  11 W with a shallow U cross sectional shape. Slots S 1 , S 2  in the wall  11 W receive the second leg  20  and the third leg  26 , respectively, there through and apertures A 1 , A 2  align with apertures  32 A 1 / 32 A 2  and,  32 B of the clip  10 . Because the clip  10  is inserted into the hollow member  11  and then the second leg  20  and third leg  26  are extended through the slots S 1 , S 2 , the arrangement can be designated an “inside mount” of the clip  10 . When fully inserted into the slots S 1 , S 2 , the support wings  28 ,  30 , being complementarily shaped relative to the shallow U shaped wall  11 W, bear against the wall  11 W and/or the interior  111  of the member  11  to resist torsional forces F 1 , F 2  (clockwise or counterclockwise, see  FIG. 5  also) that may be exerted on the clip  10  and members  11 ,  13 . The slots S 1 , S 2  and apertures A 1 , A 2  may be punched, drilled or machined into the wall  11 W. 
         [0058]      FIGS. 5-8  show an assembly  34  formed from members  11 ,  13  conjoined by clip  10  and fasteners  36 A- 36 E. The fasteners  36 A- 36 E may be “blind fasteners,” such as pop rivets that can be applied from one side of an assembly and have a head portion H, which is larger than the apertures A 1 , A 2  in member  11  (member  13  having similar apertures) and an expandable portion M, which is inserted through aligned apertures, e.g., A 1  and  32 A 1 ,  32 A 2  and then expanded (by pulling on a central, breakable core pin with a swage tip) to enlarge the expandable portion M to a dimension larger than the apertures A 1 ,  32 A 1 ,  32 A 2 , clamping the member  11  to the clip  10 . Blind fasteners do not require access to the side of the assembly  34  opposite to the head portion H. The member  13  is similarly held to the clip  10  by the action of fasteners  36 C,  36 D and  36 E. Other types of fasteners  36  may be used, such as machine or self-threading screws or bolts with mating nuts. 
         [0059]      FIGS. 9 and 10  show a clip  110  for assembling members  111 ,  113  (see  FIG. 14 ) in accordance with an embodiment of the present disclosure. The clip  110  could be described as having a stacked or double L configuration with a first leg  112  having a first panel  114 , an offset  116  and a second panel  118 . A second leg  120  extends at an angle, e.g., 90 degrees from the first panel  114 , defining the bottom portion of a first L shape and a third panel  122  depends from a reverse curve  124 , such that the third panel  122  extends parallel to the second panel  118  offset from the plane occupied by the first panel  114 . The offset  116  has dimensions approximating the thickness of the third panel  122  plus the thickness of the member  111  (wall  111 W) and permits the third panel  122  to abut against the interior surface of the wall  111 W while the first panel  114  abuts the exterior surface of the wall  111 W, when the clip  110  is installed on member  111  (See  FIG. 13 ). A third leg  126  extends from the third panel  122  at an angle, e.g., 90 degrees, forming in conjunction with the third panel  122 , another L shape that nests (with a space between second leg  120  and third leg  126 ) with the L shape formed by the first leg  112  and the second leg  120 . The second leg  120  has a flattened U shaped cross-section like second leg  20  of  FIG. 1 . A pair of support wings  129  extend from opposite sides of the first panel  114  extending at an angle, e.g., 90 degrees relative to the first panel  114 . Holes  132 A 1 - 132 E permit the passage of fasteners like rivets, screws, bolts, etc. through the clip  10 . Additional holes, like  132 F (only shown in  FIGS. 9 and 10 ) may be made to accommodate additional fasteners. 
         [0060]      FIGS. 11 ,  12  and  13  show the installation of the clip  110  into a hollow structural member  111  that may be made, e.g., from extruded aluminum or plastic. The member  111  has a wall  111 W with a shallow U cross sectional shape. Slot S 1  in the wall  111 W receives the second and third panels  118 ,  122 . When the clip  110  is rotated (counterclockwise in these views), the support wings  129  extend into slots S 2 A and S 2 B and the aperture  132 D aligns with aperture A 1  in  111 W and apertures  132 A 1 ,  132 A 2  align with aperture A 2  in wall  111 W. Because the clip  110  is partially inserted into the hollow member  111  from the outside and second leg  120 , first panel  114  and third leg  126  remain on the outside of the member  111 , the arrangement can be designated an “outside mount” of the clip  110 . When fully inserted into the slots S 2 A, S 2 B, the support wings  129  bear against the slots S 2 A, S 2 B and/or the interior  111 I of member  111  to resist torsional forces F 1 , F 2  (See  FIG. 4 ) that may be exerted on the clip  110 . 
         [0061]      FIGS. 14-16  show an assembly  134  formed from members  111 ,  113  and conjoined by clip  110  and fasteners  136 A- 136 E. The fasteners  136 A- 136 E may be “blind fasteners,” such as pop rivets that can be applied from one side of an assembly and have a head portion H and an expandable portion M, which is inserted through the aligned apertures, e.g., A 1 ,  132 A 1 ,  132 A 2  and then expanded to enlarge the expandable portion M to a dimension larger than the apertures A 1 ,  132 A 1 ,  132 A 2 , clamping the member  111  to the clip  110 . The member  113  is similarly held to the clip  110  by the action of fasteners  136 C,  136 D and  136 E. Other types of fasteners  136  may be used, such as machine or self-threading screws or bolts with mating nuts. 
         [0062]      FIGS. 17 and 18  show a clip  210  for assembling members  211 ,  213  (see  FIG. 21 ) in accordance with an embodiment of the present disclosure. The clip  210  could be described as having an L configuration with a first leg  212  having a flattened U shaped cross section. A second leg  220  extends at an angle, e.g., 90 degrees from the first leg  212 , defining the bottom portion of the L shape. A third panel  221  extends back from a reverse curve  223 , such that the third panel  221  extends parallel to the second leg  220 . An upright panel  225  extends from curve  227  parallel to and spaced from first leg  212  by a spacing approximating the thickness of wall  211 W and ends in curve  229 . A forth panel  226  extends from curve  229  parallel to panels  220  and  221 . The clip  210  could be described as L shaped with a U shaped element composed of panels  221 ,  225  and  226  attached to the bottom leg  220 , such that the bottom portion of the L is bifurcated. 
         [0063]    A pair of support wings  228  extend from opposite sides of the first leg  212  with a connected portion  228 C extending at an angle, e.g., 90 degrees relative to the first leg  212  to a bend  228 B of, e.g., 90 degrees from which a lip  228 L extends. Holes  232 A- 232 E 2  permit the passage of fasteners like rivets, screws, bolts, etc. through the clip  210 . 
         [0064]      FIGS. 19 and 20  show the installation of the clip  210  into a hollow structural member  211  that may be made, e.g., from extruded aluminum or plastic. The member  211  has a wall  211 W with a shallow U cross sectional shape. A slot S 1  in the wall  211 W accommodates the clip  210  allowing the leg  220  to project from a level above that of the edge  211 E of the member  211  and allowing the apertures A 1  and A 2  to align with holes  232 A and  232 B 1 / 232 B 2  ( 232 B 2  is not visible in this view). The slot S 1  may extend up the wall  211 W to any selected extent, so long as the apertures A 1 , A 2 , which may occupy any selected position, are positioned to align with the apertures  232 A,  232 B 1 / 232 B 2  for given slot S 1  dimensions. Because the clip  210  is slipped into the hollow member  211  via the slot and the spacing between panel  225  and leg  212 , the arrangement can be designated a “slide mount” of the clip  210 . When fully inserted into the slot S 1  and fastened by fasteners, as shown in  FIG. 21 , the support wings  228 , being complementarily shaped relative to the shallow U shaped wall  211 W, bear against the wall  211 W and/or the interior  2111  of the member  211  to resist torsional forces F 1 , F 2  that may be exerted on the clip  210  and/or members  211 ,  213 . 
         [0065]      FIGS. 21-23  show an assembly  234  formed from members  211 ,  213  and conjoined by clip  210  and fasteners  236 A- 236 E. The fasteners  236 A- 236 E may be “blind fasteners,” such as pop rivets that can be applied from one side of an assembly and have a head portion H, which is larger than the apertures A 1 , A 2  in the member  211  (member  213  having similar apertures) and an expandable portion M, which is inserted through the aligned apertures, e.g., A 1 ,  232 A and then expanded to enlarge the expandable portion M to a dimension larger than the aperture  232 A and clamping the member  211  to the clip  210 . The member  213  is similarly held to the clip  210  by the action of fasteners  236 C,  236 D and  236 E. Other types of fasteners  236  may be used, such as machine or self-threading screws or bolts with mating nuts. 
         [0066]      FIGS. 24 and 25  show a clip  310  for assembling members  311 ,  313  (see  FIG. 29 ) in accordance with an embodiment of the present disclosure. The clip  310  could be described as having an L configuration with a first leg  312  having a stub  316  extending at an angle, e.g., 90 degrees, from a first panel  318 . A second leg  320  extends at an angle, e.g., 90 degrees from a second panel  322 , defining the bottom portion of the L shape, the second panel  322  depending from a reverse curve  324  extending from the first panel  318 , such that the second panel  322  extends parallel to the first panel  318 . The stub  316  extends from the first panel  318  parallel to the second leg  320 , bracing the position of the second leg relative to the second panel  322 . Holes  332 A 1 - 332 D permit the passage of fasteners like rivets, screws, bolts, etc. through the clip  310 . The clip  310  features two holding tabs  317 A,  317 B that prevent the clip  310  from passing through a given slot in a hollow member when it is partially inserted therein to assemble a structure, as shall be described below. Reliefs  319 A,  319 B,  321 A and  321 B at the reverse curve  324 , stub  316  and bend  323  remove the burr that is produced as a consequence of forming a bend at these locations. A burr could interfere with the insertion and rotation of the clip  310  in a close fitting slot in a member to be joined. The clip  310  is also radiused at  325 A and  325 B to facilitate insertion into a mating slot in a structural member, such as the rail of a door. 
         [0067]      FIGS. 26 ,  27  and  28  show the installation of a pair of clips  310 A,  310 B into a hollow structural member  311  that may be made, e.g., from extruded aluminum or plastic. The member  311  has a wall  311 W with a shallow U cross sectional shape. Slots S 1 , S 2  in the wall  311 W receive the first legs  312  of clips  310 A,  310 B. When the clips  310 A,  310 B are inserted fully, the holding tabs  317 A,  317 B abut against the corresponding slot S 1 , S 2 , preventing the clip  310  from passing entirely through the slots S 1 , S 2  into the interior hollow  3111  of the hollow member  311 . When the clips  310 A,  310 B are rotated (counterclockwise in these views), the apertures  332 A 1 / 332 A 2  and  332 B 1 ,  332 B 2  align with apertures A 1 , A 2 , A 3 , A 4  in wall  311 W. Because the clips  310 A,  310 B are partially inserted into the hollow member  311  from the outside and second leg  320 , remains on the outside of the member  311 , the arrangement can be designated an “outside mount” of the clip  310 . 
         [0068]      FIGS. 29-31  show an assembly  334  formed from members  311 ,  313  and conjoined by clips  310 A,  310 B and fasteners  336 A- 336 H. The fasteners  336 A- 336 H may be “blind fasteners,” such as pop rivets that can be applied from one side of an assembly. The member  313  is similarly held to the clips  310 A,  310 B by the action of fasteners  336 E- 336 H. Other types of fasteners  336  may be used, such as machine or self-threading screws or bolts with mating nuts. The clips  310 A,  310 B may be used in pairs to join two members e.g.,  311 ,  313 . One of the clips connects the upper part of the horizontal extrusion (rail) with the vertical extrusion, (stile), while the other clip joins the lower part of the horizontal extrusion (rail) with the vertical extrusion. Since a pair of clips  310 A,  310 B can accommodate multiple rails of different dimensions by adjusting the position of the slots S 1 , S 2  and the resultant spacing between the clips  310 A,  310 B, the clips  310 A,  310 B could be described as “universal.” For structures having less demanding requirements of strength and rigidity, a single clip  310  could be used to fasten two members  311 ,  313 . 
         [0069]    It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the claimed subject matter. For example, while 90 degree assemblies are shown above, the clip  10 ,  110 ,  210 ,  310  may have a shape other than a 90 degree L, wherein the lower portion of the L is oriented at an acute or obtuse angle relative to the upper portion of the L, so that members  11 ,  13  may be joined at other than 90 degrees. All such variations and modifications are intended to be included within the scope of the appended claims.