Abstract:
A frame includes longitudinal members secured to one another. The longitudinal members support a spline that is normally open in a first position to provide a cavity. A fabric, such a mesh screen, is arranged over the frame so that the perimeter of the screen is received within the cavities of the longitudinal members. A movable platen is actuated to engage the spline. The splines are forced into the cavities to a second position in which the perimeter of the screen is pinched between a corner of the splines and the longitudinal members. A nose of the splines, which includes the corner, is retained in a channel of the longitudinal members.

Description:
[0001]     This application claims priority to provisional application No. 60/615,794 filed on Oct. 4, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to a longitudinal frame member and spline for use in attaching fabric to a frame.  
         [0003]     Frames used for windows and doors and for office furniture such a cubical dividers have fabric attached to a frame in some fashion. Other applications include ceiling panels. In the example of window frames and doors using screens, longitudinal frame members of the frame are used that have channels. The screen is positioned over the frame and a rubber spline having a generally circular cross section is inserted into the channels thereby retaining the screen between the spline and longitudinal frame members.  
         [0004]     Installation of fabric using the spline arrangement described above or other manners of screen attachment are typically labor intensive and costly. In the example of the splines described above, a special tool having rollers must be run along the length of longitudinal member.  
         [0005]     Window and door screens must pass an industry “push out” test. One industry standard requires that the screen be held through the longitudinal frame members for at least forty pounds of applied force. The standard can sometimes be difficult to meet.  
         [0006]     What is needed is an improved frame that requires less labor and cost to manufacture while meeting or exceeding the present industry standard for “push out.” 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     Other advantages of the present invention can be understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:  
         [0008]      FIG. 1A  is an exploded view of a frame including longitudinal frame members with square ends.  
         [0009]      FIG. 1B  is a perspective view of the frame of  FIG. 1A  shown assembled.  
         [0010]      FIG. 2A  is an exploded view of a frame including longitudinal frame members with mitered ends.  
         [0011]      FIG. 2B  is a perspective view of the frame of  FIG. 2A  shown assembled.  
         [0012]      FIG. 3  is a top elevational view of an inventive manufacturing process for the inventive longitudinal frame member.  
         [0013]      FIG. 4  is a cross-sectional view of the frame of the longitudinal frame member having a screen installed.  
         [0014]      FIG. 5  is a perspective view of barbs used to improve retention of the screen.  
         [0015]      FIG. 6  is a cross-sectional view of another example of the inventive longitudinal frame member.  
         [0016]      FIG. 7  is a cross-sectional view of a longitudinal frame member similar to  FIG. 6  with a ridge.  
         [0017]      FIG. 8  is a cross-sectional view of a longitudinal frame member similar to  FIG. 4  with a ridge.  
         [0018]      FIG. 9  is a cross-sectional view of a longitudinal frame member similar to  FIG. 8  with a spline overmolded to a tubular portion of the frame member.  
         [0019]      FIG. 10  is a cross-sectional view of the inventive longitudinal frame member wrapped in a decorative fabric. 
     
    
     SUMMARY OF THE INVENTION  
       [0020]     The inventive frame includes longitudinal members secured to one another, for example by using corner locks, to form a frame. The longitudinal members support a spline that is normally open in a first position to provide a cavity. A fabric, such a mesh screen, is arranged over the frame so that the perimeter of the screen is received within the cavities of the longitudinal members.  
         [0021]     In one example, the frame is retained on a fixed platen by stops. A movable platen is actuated to engage the spline. The splines are forced into the cavities to a second position in which the perimeter of the screen is pinched between a corner of the splines and the longitudinal members. A nose of the splines, which includes the corner, is retained in a channel of the longitudinal members.  
         [0022]     The spline is generally S-shaped. The spline may be integral with the longitudinal member or separately secured to the longitudinal member, for example, by snapping the spline into a recess in the longitudinal member.  
         [0023]     Accordingly, the present invention provides an improved frame that requires less labor and cost to manufacture while meeting or exceeding the present industry standard for “push out.” 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]     An inventive longitudinal frame member  10  is shown in the Figures. Referring to  FIGS. 1A-2B , a rigid frame is constructed from the longitudinal frame member  10  that includes a tubular portion  12  and a spline  14 . The tubular portion  12  provides a channel  26  that receives a portion of the inventive spline  14  to securely retain the screen to the member  10 , which will be discussed in more detail below.  
         [0025]     The example member  10  shown in  FIGS. 1A-4  is roll formed out of a sheet of metal so that the spline  14  is formed integrally with the tubular portion  12 . The member  10  includes a first edge  16  provided on the spline  14  and a second edge  18  provided on the tubular portion  12 , best seen in  FIG. 4 . The integral tubular and spline portions  12  and  14  are secured to provide a desired cross-sectional shape by forming a flange  20 , which is shown in  FIGS. 1A and 4 . The flange  20  may include a series of indentations  21  formed by a roller to further secure the metal in the desired shape, best shown in  FIG. 1A . In one example, the member  10  is constructed from a suitable metal that is either roll formed and/or extruded. A plastic or other material may also be used.  
         [0026]     Opposite the flange is a wall  22  having a slot  24  for receiving a corner lock  28 . The corner lock  28  includes first and second legs  30  and  32 . The first leg  30  is received in the tubular portion  12 , and the leg  32  extends from the slot  24 . The details of the use and assembly of the corner lock  28  are disclosed in U.S. patent application Ser. No. 10/825,525, filed on Apr. 15, 2004.  
         [0027]     The arrangement shown in  FIGS. 1A and 1B  depicts longitudinal frame members  10  that have square ends. In such an arrangement, it may be desirable to provide an end cap  29  on the corner lock  28 . Referring to  FIGS. 2A and 2B , the longitudinal frame members  10  include mitered ends  31  that may provide for a more aesthetic mitered joint M and also eliminate the need for slot  24 .  
         [0028]     Referring to  FIG. 3 , a machine  34  is disclosed for securing a screen  44  to be the inventive longitudinal frame members  10 . The members  10  are assembled using the corner lock  28 , or any other suitable method of attachment, to provide a frame  42 . The frame  42  is arranged on a fixed platen  36  having fixed stops  38 . Movable stops  40  are actuated to secure the frame  42  against the fixed stops  38 . The arrangement of stops  38  and  40  enables any size frame  42  to be accommodated on the machine  34 .  
         [0029]     Referring to  FIG. 4 , the screen  44  is positioned on top of the frame  42  with the spline  14  in a first position P 1 . A cavity  55  is provided between the spline  14  and the tubular member  12  in the first position P 1  for receiving the screen  44 . The spline portion includes a nose  46  having the first edge  16 . The nose  46  extends to an arch  48  having a spring portion  49  opposite the nose  46 . In the example shown in  FIG. 4 , the spring portion  49  is integral with the tubular portion  12 . In the example embodiment, the nose  46  has a smaller radius than the gradual radius of the arch  48 . The spring portion  49  has a smaller radius than the nose  46 . The spring portion  49  biases the spline  14  upward and away from the tubular portion  12 .  
         [0030]     The machine  34  includes a movable platen  50  having a flat profile  52 . By utilizing a flat profile  52 , the tooling costs are drastically reduced since a platen of particular profile requiring machining is not required, and alignment issues between the movable platen  50  and frame  42  are eliminated.  
         [0031]     The movable platen  50  is moved downward into engagement with the spline  14  moving the spline  14  from the first position P 1  to a second position P 2 , which forces the perimeter of the screen  44  into the channel  26 . The arch  48  extends above a flange  53  that, in part, provides the channel  26  along with a surface  58  of the tubular portion  12 . The movable platen  50  continues to move downward moving the spline  14  from the second position P 2  to the third position P 3 . In the position P 3 , the nose  46  is forced further into the channel  26  securely retaining the perimeter of the screen  44 . The flexible spline  14  deflects without yielding. The nose  46  has a sharp corner  56  on the first edge  16  that digs into the screen  44  to retain the perimeter of the screen between the corner  56  and the surface  58 . In the third position P 3 , the arch  48  has a larger radius than it did in first position P 1 , and the nose  46  has smaller radius than it did in the first position P 1 .  
         [0032]     To further improve retention of the screen  44 , barbs  54  may extend upward from the surface  58  and away from the channel  26 , as is show in  FIG. 5 .  
         [0033]      FIG. 6  depicts another example longitudinal frame member  60 , which is extruded. The longitudinal frame member  60  includes a tubular portion  62  having a separate spline portion  72 . The tubular portion  62  provides a recess  64  having a protrusion  66  and fulcrum  68 . A spring portion  80  of the spline portion  72  is inserted into the recess  64 , and an edge  82  is retained by the protrusion  66 . The spring portion  80  acts against the fulcrum  68  when moving between the first, second and third positions P 1 , P 2  and P 3 . Similar to the embodiment described in  FIG. 4 , the spline portion  72  includes an arch  74  and nose  76 . The nose  76  is forced into the channel  78  by the movable platen  50 . The screen  44  is retained between the nose  76  and surface  70 .  
         [0034]     The screen  44  begins to tear, which occurs at around 125 pounds of applied force, without the screen pulling out of the channel  26 .  
         [0035]     Referring to  FIG. 7 , the spring portion  80  is retained in the recess  64 . The arch  74  may or may not include an apex, depending upon the geometry of the spline  14  and tubular member  12 . The fulcrum  68  extends from the surface  70 . A ridge  86  also extends from the surface  70  to lift an edge portion  88  of the screen  44  away from the surface to better ensure that the corner  56  engages and holds the screen  44 . The ridge  86  is also shown for roll-formed longitudinal frame members  10  in  FIG. 8 .  
         [0036]     In another example, the spline  14  can be adhered to the tubular member  12  by any suitable process, such as by laminating or overmolding, as shown in  FIG. 9 .  
         [0037]     The inventive longitudinal frame member  10  permits easy replacement of the screen. The spline  14  may be “zippered” open and the damaged screen removed and replaced. With the new screen positioned as desired, the spline  14  can be forced back into the channel  26  using a block of wood and hammer.  
         [0038]      FIG. 10  depicts the inventive longitudinal frame member  10  for furniture or other applications in which it is desirable to conceal the tubular member  12 . A decorative fabric  94  is wrapped around a side  92  other than the side that supports the spline  14 .  
         [0039]     The invention has been described in an illustrative manner, and it is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.