Patent Publication Number: US-2006000176-A1

Title: Dual-durometer divided bar

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to the field of prefabricated construction elements such as construction panels and other elements to be used therewith, and relates more particularly to divider bars used with such panels.  
      2. Related Background Art  
      The use of pre-made panels in the construction of interior walls, ceilings, etc., is well known. Many such panels are commercially available, from a great variety of materials. Fiberglass-reinforced plastic (“FRP”) panels have been used for this purpose, and examples of recent developments relating to such panels are disclosed in commonly assigned co-pending applications Nos. 10/081,629 and 10/360,785, the contents of both of which are incorporated herein by reference.  
      Fiberglass-reinforced plastic panels are widely used throughout the construction and building materials industry. That material offers a number of significant and advantageous features, including resistance to growth of mold, mildew and bacteria, high impact strength, resistance to moisture and to chemical interaction, and stain resistance. FRP also provides a sanitary finish, requires only low maintenance, and can be installed easily.  
      FRP panels are commonly secured in place by gluing panels and using molding strips placed between the edges of two neighboring panels, as well as inside corners, outside corners, and stop or cap moldings. Such strips are known by a variety of other names, including seam treatments, extrusions (due to the method commonly used in their manufacture), trim, division or dividing bar or strip, profile, T- or H-molding, T-strip, and decorative or decorator molding. One example is disclosed in U.S. Pat. No. 4,913,576, the entire disclosure of which is incorporated herein by reference.  
      In fact, a great deal of previously available paneling has been more functional than decorative, and the product structures disclosed in the above-mentioned co-pending applications were created in order to provide a more decorative and esthetically more appealing product than had previously been available. A conventional divider bar is quite functional in appearance, however, and may detract from the esthetic appearance of such a decorative panel, the exposed surface of which may bear a decorative pattern. It would be desirable to provide a divider bar that can be used with decorative panels without detracting from the pleasing appearance of the panels.  
      Also desirable in this regard would be a division molding that would allow custom coloration of the division molding to be provided. Painting or similarly tinting a conventional division molding, however, has the disadvantage that the painted or tinted surface is exposed to the air.  
      It would also be desirable, and extremely advantageous, to have a division molding that would have a portion of its structure flexible in such manner as to make it possible to obtain a positive seal without the need to use caulk or a sealant, and to provide a continuous expansion/contraction joint.  
     SUMMARY OF THE INVENTION  
      It is an object of the present invention to provide such a divider bar which has any one, several or all of these characteristics.  
      One aspect of the invention is a divider bar for use with paneling, which comprises a first and a second portion and a stem portion joining the first and second portions. The first and second portions are shaped and arranged to engage an edge region of at least one panel, and the first portion is made of a first material, and the second portion is made of a second material. Preferably, the first material is relatively flexible, while the second material is relatively rigid. In particular, the flexibility of the first material should be such that when the edge of the panel is engaged by the divider bar, the result is a good seal between the panel and the bar even without the use of a caulk or sealant, and this seal is maintained even if the panel expands or contracts (for example, under the influence of temperature). The first and second materials are also preferably transparent, or at least the first is. A colorant may be added to the second material, or a decorative material may be applied underneath the transparent portion, so as to be visible through the transparent portion.  
      In addition, the first and second portions extend at least generally parallel to each other and are shaped to engage the edge region of the panel between them, and most preferably, the first portion extends from the stem portion and arcs generally toward the second portion.  
      It is preferred, and particularly advantageous, that the divider bar is made by means of an extrusion process, and especially, by means of a co-extrusion process.  
      These and other features and advantages of the present invention will be more fully understood from a consideration of the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a general view illustrating the use of a divider bar.  
       FIG. 2A  is an end view of a divider bar according to a preferred embodiment of the present invention, and  FIG. 2B  is a cross-sectional view of the embodiment of  FIG. 2A .  
       FIG. 3  is an end view of another embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      As is well known, divider bars are conventionally used to provide a seal between adjacent FRP panels. Part of the divider bar extends from the backing surface, and has two channels formed in it, to receive the edges of two panels. Conventionally, adhesive or caulk is laid down in the channels, or on the edge of the panels, and the panel edges are then placed in the channel portions of the divider bars. A portion of the divider bar remains visible after installation. As will be appreciated from the following, the preferred embodiment of the present invention is a divider bar that can be used with no need for any caulk or sealant. An example is shown in  FIG. 1 , illustrating the engagement of the divider bar with two sheets of paneling (all shown in section).  
      According to the preferred embodiment of the present invention, the divider bar has a first portion  12 , which remains visible after installation, and a second portion  14  that floats behind the panels. The first and second portions are joined by a stem portion  16 .  
      The first and the second portion are made of different materials, the second being of a relatively rigid material, and the first, of a more flexible material. At least the material of the first portion is clear, and preferably colorless, and the material of the second portion preferably is also colorless and clear.  
      Examples of materials that are suitable for use as the materials of the first and second portions are varieties of polyvinyl chloride (“PVC”) having different durometer hardnesses, and PVC is advantageous in being very easy to handle, but it is within the broad scope of the invention to use other materials that have the desired qualities.  
      In the preferred embodiment shown in  FIGS. 2A and 2B , the stem portion is made of the same material as the first portion, and in fact both are produced by extrusion as a single strip. Most preferably, the entire divider bar is produced by co-extrusion of the two materials. The technology required for coextrusion of materials of the types suitable for use in making a divider bar according to the invention is well known to those in the relevant art, and need not be discussed in any detail. Also, it is within the ordinary skill in the relevant art to extrude a profile of PVC or other suitable material in such manner that the profile has a gradient (either uniform or not) of hardness from one part of the profile cross-section to another, and it is within the scope of the invention to make the divider bar in this fashion, giving the first portion and stem greater flexibility and the second portion, a greater hardness.  
      More broadly, it is desired that the first portion be made of a flexible material, and the second of a more rigid material, that can easily be joined together to form the profile, and while it is preferred that the materials be ones that permit the use of co-extrusion for this purpose, other choices of materials that nonetheless can be joined to each other may be considered without going beyond the scope of the invention.  
      As illustrated, the second portion of the divider bar preferably has a flat surface to be placed against the supporting surface, while its opposite surface is flat near the stem portion but beveled toward the edges. The first portion is preferably somewhat arc-shaped, curving from the stem portion toward the second portion, so as to grip the panels in the channels defined between the first and second portions.  
      The preferred embodiment is shaped in such manner as to receive the edge of the panels sealingly, even without the use of caulk or sealant. Moreover, because of the flexibility of the first portion and stem, the divider bar also serves as an expansion/contraction joint. That is, the pressure between the divider bar and the panels ensures a good seal between the divider bar and the panels, even though the panels may expand and contract considerably due to temperature changes. This characteristic affords a desirable high degree of protection against the growth of bacteria or other microbes in the joints.  
      If the first portion and stem of the divider bar are made of a colorless, transparent material (as is preferred), then another advantage is available, as well. The second portion can be provided with a coloring suitable in light of the color(s) of the panels with which the divider bar is to be used, or can be provided with a decorative appearance in some other fashion, such as being provided with a wood grain or abstract. The second material can contain a colorant for this purpose, or the back surface of the divider bar can have the desired decoration (color, wood grain or the like) applied to its back surface. It is of course within the scope of the invention to provide a colorant or other material for decorative purposes in the first material instead, or in addition to, that provided for the second portion.  
      Thus, a great variety of decorative appearances can be provided, including a desirable architectural detail of an appearance of depth if the coloring is provided in the second portion, the first portion and stem being transparent. Moreover, since no painted surface need be exposed (since any paint that is desired can be applied to the back of the second portion, and thus be protected form the atmosphere by the divider bar itself), the durability of the resulting pleasing appearance can be enhanced.  
      Another embodiment, having a different cross-sectional shape and dimensions, but with similar first portion  12 ′ and stem portion  16 ′, of flexible and transparent material, and second portion  14 ′ of rigid material.  
      While the illustrated structure is the preferred one, other shapes can be adopted, provided that the divider bar can still receive the edge of the panel in the desired manner. Moreover, while the preferred embodiment is shown as a divider bar, it will be understood that other types of profiles that are of use are known, as mentioned above, including inside and outside corners, and stop or cap moldings, and these types of products also may be manufactured using the principles described above to have the advantageous characteristics of the illustrated divider bar. Such additional structures also are within the scope of the invention, and are to be understood as being included in the term “divider bar” herein.  
      While the preferred embodiment has been described in detail to illustrate the present invention and its uses and advantages, and in sufficient detail to enable those of ordinary skill to make and use the invention, many variations and modification of the disclosed structure will be apparent to those skilled in the art. Accordingly, the scope of the invention is not to be limited by the details of the foregoing description, but only by the terms of the appended claims.