Abstract:
A rack for shipping and storing a plurality of glass panels includes a frame which holds a bottom support and a rear support in planes that intersect at substantially a right angle. The bottom and rear supports have notches to receive edges of the panels. The rear support has a plurality of channels with a separate retainer slidably received in each channel for engaging an upper edge of a panel placed in the rack. A spring loaded mechanism maintains the retainers in engagement with the respective panel, thereby holding the panels in the rack.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to containers for storing and shipping panels of material, such as panes of glass. 
     2. Description of the Related Art 
     Flat panels of glass are commonly shipped in a bundle with a powder between abutting panels. The bundle often is secured in a steel rack by metal or plastic bands which encircle the bundle. The racks often are stacked one upon another in a warehouse with the lower racks supporting the weight of the racks above. 
     More recently packaging has been devised which employ four corner caps that fit along the intersection of the edges of the bundle of glass panels, as described in U.S. Pat. Nos. 5,813,536 and 6,098,804. Corrugated cardboard or wooden sheets extend vertically between adjacent pairs of the corner caps to prevent the stack from racking. Metal or plastic bands then are placed around the bundle to hold the corner caps in place. Although that corner cap structure was an improvement over the racks used previously, the glass panels carried the weight of bundles stacked above. 
     The prior packaging structures often required that all the panels have the same size and shape. This presents a problem when a particular customer orders a variety of glass panels, in which case separate packaging structures must be used for each size. Furthermore, a customer may require that the different sized pieces be packaged in the particular sequence that the customer needs them in order to fabricate an assembly of glass panels, such as a large window unit that has glass panes of different sizes. 
     Certain glass panels have delicate coatings that are easily marred and thus must be packaged without touching other panels. 
     As a consequence, there is a desire to be able to mix glass panels of different sizes and shapes in a single packaging structure and individually support each panel. 
     SUMMARY OF THE INVENTION 
     The present invention provides a protective packaging structure in which to ship and store a bundle of panels, such as glass panes. Each panel has two major surfaces and a plurality of edge surfaces between the two major surfaces. 
     The packaging structure has a frame to which a bottom support and a rear support are attached in planes that intersect at substantially a right angle. The bottom support and the rear support hold a plurality of panels in parallel planes that are perpendicular to the planes of those supports. The rear support has a major surface with a plurality of channels. A separate retainer is slidably received in each channel of the rear support in order to engage an upper edge of one of the panels placed in the packaging structure. That engagement applies force which holds the panels against the bottom support. A mechanism, such as a spring, maintains each retainer in engagement with the respective panel. 
     In the preferred version of the present packaging structure, each panel is slid into notches formed in the bottom and rear supports, thereby restraining the panels from moving transversely to the supports. One of the retainers then is brought into engagement with the panel to force the panel against the bottom support and hold the panel in the packaging structure. Preferably, the planes of the bottom support and the rear support are canted with respect to the horizontal and vertical planes, respectively. This canting results in gravity causing the panels to nest into the intersection of those supports. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of several panels of glass contained in a packaging structure according to the present invention; 
     FIG. 2 is a cut-away view of a corner of the packaging structure; 
     FIG. 3 is an enlarged view of part of the rear support of the packaging structure; 
     FIG. 4 is a cut-away isometric view of a support bar in the packaging structure; and 
     FIG. 5 is a cut-away isometric view of a top section of the rear support. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to FIG. 1, a packaging structure, commonly referred to as a rack  10 , holds a plurality of rectangular glass panels  12  and  13  each having two major surfaces with four narrow edges extending between the two major surfaces. The glass panels  12  and  13  are placed on edge, parallel to one another in the rack  10 . Although the present invention is being described in the context of a rack for glass panels, one should appreciate that the novel concepts can be used in structures that hold other types of panels. 
     The rack  10  has a rectangular frame  11  formed by four primary rails  14 , the ends of which are connected at four corners. A separate vertical post  16  or  18  is located at the rear corners of the frame  11  and extends above and below the frame for the full height of the packaging structure. The two front corners of the frame  11  have short corner members  22  and  24  that are flush with the top surface of the frame  11  and extend downward from the frame. The top of each of these corner members  22  and  24  has a square aperture  26  therein as shown in FIG.  2 . Separate bottom rails  42  extends between adjacent pairs of the rear posts  16  and  18  and corner members  22  and  24  beneath the primary rails  14 . Vertical supports  41  extend between the primary and bottom rails  14  and  42  creating openings there between through which tines of a forklift can fit to transport the rack filled with glass panels. 
     Referring to FIGS. 1 and 2, a removable front gate  28  has a pair of vertical posts  30  and  32  which have bottom ends with square tabs  34  that fit into the square apertures  26  in the rack corner members  22  and  24  to mount the gate on the frame  11 . The tops of the gate posts  30  and  32  are at the same height as the tops of the posts  16  and  18  at the rear corners of the frame. A pair of horizontal gate rails  36  and  38  extend between and are fixed to the two gate posts  30  and  32 . 
     The top of each post  16 ,  18 ,  30 , and  32  of the rack has a cylindrical knob  20 ,  21 ,  39 , and  40 , respectively. The bottom ends of posts  16  and  18  and of corner members  22  and  24  are open for receiving the post knobs  20 ,  21 ,  39 , and  40  of another rack when two racks loaded with glass panels are stacked one on top of the other. The engagement of the knobs and apertures secures the stacked racks together. When the racks are stacked on top of each other, the weight of the upper racks is transferred through the posts  16 ,  18 ,  30 , and  32  and the glass panels  12  and  13  do not receive that force. 
     A bottom support  43  is formed by six bars  44  which extend across the interior of the frame  11  to provide support for the bottom edges  15  of the glass panels  12  and  13 . These frame support bars  44  lay in a common plane between two opposite primary rails  14  of the frame  11  and are equally spaced along those primary rails. The plane of the bars  44  of the bottom support  43  slopes downward at a six degree angle going from the front of the rack  10  at posts  22  and  24  to the rear at which posts  16  and  18  are located. 
     The frame support bars  44  are shown in detail in FIG.  4  and comprises a rectangular metal tube  47 , that is welded to the opposite primary frame rails  14 , and a metal channel  55  with front and rear edges rolled over. A plurality of plastic panels  45  are slid end to end into the channel and a number of machine screws secure the channel and the panels to the metal tube  47 . The plastic panels  45  have a series of tabs  49  projecting upward at regular intervals along the length of the channel  55 , thereby forming a plurality of notches  46  between adjacent tabs. The tabs  49  and notches  46  are aligned from one support bar  44  to another so that the bottom edge  15  of each glass panel  12  or  13  fits within a linear array of notches  46 . The sides of the notches  46  are tapered to center the glass panels between the upstanding tabs  49  and restrain the glass panels  12  and  13  from moving along the frame support bars  44  toward each other. 
     Referring again to FIG. 1, a rear support  50  extends from the rear of the frame  11  upward and is attached to the upper portions of the two rear posts  16  and  18 . The plane of the rear support  50  is tilted backward to be substantially orthogonal to the sloping plane of the bottom support bars  44 . As a result of this tilted arrangement, two abutting edges  15  and  17  of the rectangular glass panels  12  and  13  placed in the rack  10  nest against the bottom support bars  44  and the rear support  50  due to gravity. The plane of the rear support  50  does not have to be precisely orthogonal (i.e. exactly 90°) to the plane of the bottom support bars  44  as long as the edges  15  and  17  of the glass panels  12  and  13  are retained by notches in the bottom and rear supports  43  and  50 , as will be described. 
     The rear support  50  is formed by four horizontal support strips  52  that extend between the rear vertical posts  16  and  18  and are spaced apart vertically. A cap  60  is attached across the top of the rear support  50 . As illustrated in FIG. 3, each plastic support strip  52  is held within a metal channel  51  that extends horizontally between the rear vertical posts  16  and  18 . The rear support strips  52  have a plurality of outwardly projecting walls  53 , thereby forming tapered notches  54  there between. The notches  54  in the four rear support strips  52  align in the vertical direction. That alignment enables the rear vertical edges of the glass panels  12  and  13  to wedge into those notches  54  upon being fully inserted into the rack  10 . Thus the glass panels are further restrained from moving against each other during shipment. 
     A separate dove tail track  56  is received and retained in the bottom of each of the notches  54  in the rear support strips  52 . Therefore, the plurality of dove tail tracks  56  extend in a generally vertical direction along the full height of the rear support  50 . These channels form a series of vertically extending dove tail grooves for the rack  10 . 
     With reference to FIGS. 1 and 5, a separate panel retainer  70  is slidably received within each dove tail track  56  of the rear support  50 . Each retainer  70  has an inverted L-shaped member  72  with a vertical leg  74  that is adapted to fit into and slide along the associated dove tail track  56 . Specifically the vertical leg  74  has a dove-tail cross section that mates with the dove-tail groove of the track  56  to confine the retainer  70  in the rear support  50 . The top portion of the vertical leg  74  has an enlarged knob  77  for grasping by a user to facilitate raising the panel retainer  70  in the groove formed by the dove tail track  56 . A pair of wings  76  extend outward from the top portion of the vertical leg  74 . The proximate ends of the wings  76  are closely spaced to pass between the walls  53  of the rear support strips  52 . The distal ends of the wings  76  are separated farther and have transverse apertures there through. The panel retainer  70  also has an arm  78  that is pivotally coupled to the wings  76  of L-shaped member  72 . Specifically a pin  80  extends through the apertures in the two wings  76  and a corresponding aperture in arm  78 . 
     FIG. 5 illustrates the extended pivotal position of the retainer arm  70  as when it is positioned on top of a glass panel  12  or  13  shown in FIG.  1 . The retainer arm  70  is able to pivot downward into a retracted, substantially vertical orientation as illustrated for arm  79  in FIG. 1, when a glass panel is not positioned within the associated portion of the rack. The arms  78  may be biased into the retracted position by a torsion spring (not shown) that wraps around the pivot pin  80 . Retraction of the arms  70  and removal of the front gate  28  enables the empty racks to be stacked in a compact nesting arrangement to facilitate transportation. Note that a knob  81  is located on top of a side primary rail  14  near the rear posts  16  and  18  to engage another nesting rack and secure the assembly together. 
     A constant force spring  84  extends downward from the bottom portion of the L-shaped member  72  within each of the channels on the rear support  50 . The spring  84  is held in place at the bottom of the rear support  50 . The constant force spring  84  acts like a coiled tape measure and exerts a downward force on the panel retainer  72  which pulls the retainer toward the bottom of the respective channel. The constant force spring  84  exerts a constant downward force of 13 to 23 Newtons. When the retainer  70  is in the fully raised position as shown for the retainer in FIG. 5, a locking tab  75  engages a top edge of the end cap  60  to hold the retainer in that position against the downward force exerted by the spring  84 . 
     Referring again to FIG. 1, when a user desires to load glass panels into the rack  10 , the front gate  28  is removed by pulling upward so that the bottom ends of the gate posts  30  and  32  come out of the frame post  22  and  24 . This allows large glass panels  12  to be placed into the rack one at a time and into the notches of the bottom support bars  44 . The glass panel then is slid toward the rear support  50  and into the notches between the tabs of the support strips  52 . The locking tab  75  is disengaged from the upper edge of the cap  60  and slid downward in the respective track  56  of the rear support  50 . Note that the tapered notches in the rear support strips  52  do not allow the edge of the glass panel to enter the dove tail grooves in the tracks  56  (see FIG. 3) as that would interfere with sliding the retainer  70 . 
     After the retainer  70  engages the top edge  19  of the glass panel  12 , the downward force of the constant force spring  84  is sufficient to open and maintain that engagement and withstand vibration normally encountered during shipment which could otherwise dislodge the glass panel from the bottom support notches  46 . That downward force also keeps the glass panels between the tabs of the support strips  52  on the rear support  50 . It should be appreciated that the six degree tilt of the bottom support  43  and the rear support  50  in the frame  11  results in the glass panels  12  and  13  tending to nest against the bottom and rear supports due to gravity. This effect also retains the glass panels  12  and  13  within the rack  10 . 
     Glass panels  12  and  13  of different size can be placed within the same rack. As illustrated, panel  13  is significantly smaller than the maximum size which can be accommodated by the rack  10  and nevertheless is firmly held in place by the retainer  70 . 
     The foregoing description was primarily directed to a preferred embodiment of the invention. Although attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.