Abstract:
A molding system conceals gridwork in suspended ceilings. A main or cross piece molding comprises two opposed clip assemblies for attaching to inverted T-bars. The clip assemblies comprise a vertical portion. Upper and lower fingers protrude horizontally from the vertical portion and towards the opposed clip assembly. Upward projecting arms extend from upper edges of the vertical portions and have upward edges. Horizontal arms extend from the upward edges and extend away from the clip assemblies. A decorative portion spans between distal ends of the horizontal arms. A perimeter molding for attaching to L-bars comprises a first horizontal arm configured to abut a lower portion of a horizontal surface and a second horizontal arm that is parallel to the first horizontal arm. First and second legs connect to the second horizontal arm. The second leg abuts an upper, distal portion of the horizontal surface near a hem.

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to decorative moldings for drop ceiling grids. 
     BACKGROUND 
     Current drop ceilings can comprise a series of interconnected supports for installing acoustic, insulating, or decorative tiles. The gridwork for suspended ceilings may comprise L-bars anchored to walls around a ceiling perimeter. T-bars may be suspended from anchors to extend latitudinally and longitudinally with respect to each other to create a grid. The L-bars and T-bars cooperate by overlapping and/or interlocking to provide support for tiles. 
     Many configurations of hardware are possible, including a system of main runners, cross grids, and perimeter wall runner grids, such as a system marketed by Armstrong World Industries. 
     Since the L-bars and T-bars are largely functional, their appearance can be characterized as plain or industrial. In addition, since the L-bars and T-bars tend to be metal, paint coatings can be marred during installation. Therefore, various prior art designs provide for interlocking tiles or other decorative means for concealing the L-bars and T-bars. 
     SUMMARY 
     In one embodiment, a clip-on molding for concealing gridwork in suspended ceilings may comprise two opposed clip assemblies. Each clip assembly comprises a vertical portion having a lower edge and an upper edge and a lower finger protruding horizontally from the lower edge of the vertical portion and towards the opposed clip assembly. An upper finger protrudes horizontally from the vertical portion and towards the opposed clip assembly. Upward projecting arms extend from the upper edges of the vertical portions, the upward projecting arms having upward edges. Horizontal arms extend from the upward edges of the upward projecting arms, and the horizontal arms extend away from the clip assemblies and have distal ends. A decorative portion spans between distal ends of the horizontal arms. The lower surfaces of the upper fingers may be parallel to the upper surfaces of the lower fingers, thereby forming grooves. The grooves may be configured to accept opposed edges of gridwork. 
     In yet another embodiment, a snap-on molding may conceal perimeter gridwork in suspended ceilings. A first horizontal arm may abut a lower portion of a horizontal surface. A second horizontal arm may be parallel to the first horizontal arm. A first leg may connect to a first end of the second horizontal arm. A second leg may connect to a second end of the second horizontal arm, with the second leg configured to abut an upper, distal portion of the horizontal surface near a hem on the horizontal surface. Serially connected connecting arms may span between an upper end of the second leg to an end of the first horizontal arm. 
     A molding system may conceal peripherally, longitudinally and/or laterally extending gridwork in suspended ceilings. The system may comprise at least one clip-on molding and at least one snap-on molding. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention. 
         FIG. 1A  is an example of a front-view profile of a main or cross piece molding according to one embodiment of the invention. 
         FIG. 1B  is an alternate example of a front-view profile of a main or cross piece molding according to a second embodiment of the invention. 
         FIG. 2A  is an example of a front-view profile of a perimeter molding according to a third embodiment of the invention. 
         FIG. 2B  is an example of a front-view profile of a perimeter molding according to a fourth embodiment of the invention. 
         FIG. 2C  is an example of a front-view profile of a perimeter molding according to a fifth embodiment of the invention. 
         FIG. 2D  is an example of a front-view profile of a perimeter molding according to a sixth embodiment of the invention. 
         FIG. 3  is an enlarged example of a front-view profile of a main or cross piece molding shown in  FIG. 1B . 
         FIG. 4  is a side view of a main piece molding. 
         FIG. 5A  is a side view of a first cross piece molding for spanning between parallel main piece moldings. 
         FIG. 5B  is a side view of a second cross piece molding for spanning between a perimeter molding and a main piece molding. 
         FIG. 6  is a side view of a perimeter molding. 
         FIG. 7  is an example of an L-bar and T-bar drop ceiling assembly having a perimeter molding, two main piece moldings, a first cross piece molding, and a second cross piece molding. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present exemplary embodiments, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     In an effort to provide a lightweight and easily installed molding for concealing L-bars and T-bars, proposed herein is a clip-on extruded molding system. The system provides for a perimeter molding that can attach to L-bars and also provides cooperating main and cross piece moldings that can attach to the T-bars. The moldings abut one another to provide a substantially unitary appearance. 
     Since the proposed moldings are one-piece and clip-on in nature, it reduces the material content greatly over the prior art, resulting in a thin and lightweight product. Since the material can be uniform in composition in some embodiments, nicks and scratches in the molding are not as readily visible as they would be on powder-coated metal hardware. The design also eliminates the need for associated metal clips, magnetic or other tapes, or adhesives, thereby making installation simple. The one-piece design also reduces fabrication costs and time to market. 
       FIG. 1A  shows an example of a profile  100  for a main or cross piece molding for attaching to a non-limiting example of a T-bar T. The example of a T-bar T, as shown, has a horizontal portion, a vertical portion, and a hollow portion. Hollow portion facilitates hanging the T-bar T from hangers anchored to the portion of the ceiling to be concealed. The vertical portion comprises a distance that allows sufficient room for positioning a tile in the grid. Horizontal portion traditionally supports a tile, but as shown in  FIG. 1A , horizontal portion is clip-fit to decorative molding  100 , and decorative molding  100  supports a tile on upper edge  102 . 
     The profile  100  may comprise a first side and an opposite side. The first side comprises a clip assembly. The clip assembly may comprise a groove between a first finger  108  and a second finger  106 . First finger  108  and second finger  106  are integrally formed with a vertical surface  104 . Second finger  106  may have a triangular tab shape to assist with the alignment of T-bar T with the groove. The T-bar T may slide along the triangular tab shape of second finger  106 , thereby facilitating a snap-fit with T-bar T. The triangular tab shape also creates a strong grip on the T-bar since the material comprising the triangular tab shape prevents the finger from flexing. 
     Vertical surface  104  is a sufficient distance from upper edge  102  to provide space for the formation of the triangular tab shaped second finger. The vertical distance also enables a pressure-enhanced grip on T-bar T by transferring pressure exerted on upper edge  102  towards the clip assembly, thereby forcing clip assembly towards T-bar T. Upper edge  102  may receive a pressure load from the weight of tiles placed upon it. In addition, the molding may be designed to accommodate up to three tensile pounds without losing the grip capacity of the clip assembly. 
     The opposite side of profile  100  mirrors the first side, with a clip assembly, vertical surface and upper edge. The first side and opposite side are connected by a section of material that may comprise any one of a number of decorative designs which may include, for example, one or more ogees, bullnoses, roundovers, squares, semi-circles, groove patterns, chamfers, coves, rabbets, or flutings. 
       FIG. 1B  shows an alternate profile  120  for a main or cross piece decorative molding. The molding grips T-bar T with a clip assembly comprising a groove, lower finger  128  and upper finger  126 . Upper finger  126  is integral with a diagonal surface  124 . The triangular tab shape of upper finger  126  transitions seamlessly to a surface of diagonal surface  124 . 
     The combination of the diagonal surface and the triangular tab shape assists with the alignment of T-bar T with the groove. The T-bar T may slide along diagonal surface  124 , along the triangular tab shape of upper finger  126 , and into the groove, thereby facilitating a snap-fit with T-bar T. The triangular tab shape also creates a strong grip on the T-bar since the material comprising the triangular tab shape prevents the finger from flexing. 
     Vertical surface  124  is a sufficient distance from an upper edge  122  to provide space for the formation of the triangular tab shaped second finger. The vertical distance also enables a pressure-enhanced grip on T-bar T by transferring pressure exerted on upper edge  122  towards the clip assembly, thereby forcing clip assembly towards T-bar T. Upper edge  122  may receive a pressure load from the weight of tiles placed upon it. In addition, the molding is designed to accommodate up to three tensile pounds without losing the grip capacity of the clip assembly. 
     The opposite side of profile  120  mirrors the first side, with a clip assembly, vertical surface and upper edge. The first side and opposite side are connected by a section of material that may comprise any one of a number of decorative designs which may include, for example, one or more ogees, bullnoses, roundovers, squares, semi-circles, groove patterns, chamfers, coves, rabbets, or flutings. An exemplary molding pattern is shown in  FIG. 1B , and is used throughout the disclosure for consistency. 
     Turning now to  FIGS. 2A-2D , alternative designs for perimeter profiles are shown. The perimeter profiles allow for a cohesive design throughout a ceiling assembly by providing a vertical distance between an L-bar and a ceiling tile that will comport with a vertical distance created between a T-bar and a ceiling tile. The exterior design of the perimeter profiles also allows for a smooth transition between cross-piece moldings and the perimeter of a room, as will be discussed in more detail below in reference to  FIG. 7 . 
     A first perimeter profile  200  is shown attached to an L-bar L. The components of first perimeter profile  200  cooperate to exert pressure on a horizontal portion of L-bar L and to receive a hem H in a way that prevents the profile from slipping off of L-bar L. 
     A first vertical arm  202  contacts a first horizontal portion of L-bar L and connects to a first horizontal arm  204 . Second vertical arm  206  extends downward from first horizontal arm  204  and contacts a second horizontal portion of L-bar L. Vertical side  207  connects first horizontal arm  204  with a second horizontal arm  208 . Third vertical arm  210  extends towards second vertical arm  206  and contacts an opposite side of second horizontal portion of L-bar L. Second vertical arm  206  and third vertical arm  210  together cooperate to exert pressure on the second horizontal portion of L-bar L. Second vertical arm  206  and third vertical arm  210  also allow hem H of L-bar L to pass between them during installation and cooperate to prevent hem H from passing backwards out of the decorative molding. This cooperation secures a molding using the design of first perimeter profile  200  to a ceiling perimeter. 
     Second horizontal arm  208  also connects to fourth vertical arm  212 , which connects to third horizontal arm  214 . Third horizontal arm  214  abuts a horizontal length of L-bar L, including an opposite side of first horizontal portion of L-bar L. First vertical arm  202  and third horizontal arm  214  cooperate to press against L-bar L, thereby assisting with securing a molding using the design of first perimeter profile  200  to a ceiling perimeter. 
     The weight of a tile bearing down on first horizontal arm  204  also assists with providing pressure to press first vertical arm  202  and second vertical arm  206  against the L-bar L. When the molding is mounted, fourth vertical arm  212  abuts a wall thereby providing counter support to third horizontal arm  214 . 
       FIG. 2B  shows an example of a second profile for a perimeter molding. First vertical arm  222  connects to first horizontal arm  224 . Second vertical arm  226  extends downward from first horizontal arm  224 . Vertical side  228  spans between first horizontal arm  224  and second horizontal arm  232 . Third vertical arm  230  and fourth vertical arm  234  extend upward from second horizontal arm  232 . Third horizontal arm  236  connects to fourth vertical arm. 
     First vertical arm  222  cooperates with third horizontal arm  236  to hold a portion of L-bar L. Third horizontal arm  236  can abut a horizontal distance of L-bar L. 
     Second vertical arm  226  and third vertical arm  230  extend towards each other to exert pressure on a second horizontal portion of L-bar L. Second vertical arm  226  and third vertical arm  230  also allow hem H of L-bar L to pass between them during installation and cooperate to prevent hem H from passing backwards out of the molding. The cooperation of first, second, and third vertical arms  222 ,  226 , and  230 , and third horizontal arm  236  secures a molding using the design of second perimeter profile  220  to a ceiling perimeter. 
     The weight of a tile bearing down on first horizontal arm  224  also assists with providing pressure to press first vertical arm  222  and second vertical arm  226  against the L-bar L. 
       FIG. 2C  shows an example of a third profile for a perimeter molding. A diagonal arm  242  extends at an angle away from first horizontal arm  244 , which connects to vertical arm  246 . Vertical arm  246  connects to second horizontal arm  248  which connects to vertical side  250 . Third horizontal arm  252  spans between vertical side  250  and second vertical arm  254 . Fourth horizontal arm  256  connects to second vertical arm  254 . Fourth horizontal arm  256  and first horizontal arm  244  may abut opposing horizontal surfaces of L-bar L and together may exert sufficient pressure on L-bar L to secure a perimeter molding to an L-bar. First horizontal arm  244 , first vertical arm  246 , and third horizontal arm  256  also cooperate to form a snap fit. The snap fit allows hem H of L-bar L to pass into the interior of the molding during installation while preventing hem H from passing backwards out of the molding. 
     Diagonal arm  242  provides a means for lifting first horizontal arm  244  and first vertical arm  246  a sufficient distance away from third horizontal arm  256  to permit hem H to exit the decorative molding. 
     Pressure caused by the weight of a tile bearing down on second horizontal arm  248  transfers to press first vertical arm  246  and first horizontal arm  244  against the L-bar L. When the molding is mounted, second vertical arm  254  abuts a wall thereby providing counter support to fourth horizontal arm  256 . 
       FIG. 2D  shows an example of a fourth profile for a perimeter molding. A diagonal arm  262  extends at an angle away from first horizontal arm  264 . A diagonal arm  266  extends at an opposite angle away from first horizontal arm  264 . Second horizontal arm  268  spans between second diagonal arm  266  and vertical side  270 . Third horizontal arm  272  spans between vertical side  270  and first vertical arm  274 . A fourth horizontal arm  276  connects to second vertical arm  278  and to first vertical arm  274 . Fifth horizontal arm  280  also connects to an upper portion of first vertical arm  274 . 
     First horizontal arm  264 , fifth horizontal arm  280 , first vertical arm  274 , and diagonal arm  266  cooperate to form a snap fit. The snap fit allows hem H of L-bar L to pass into the interior of the molding during installation while preventing hem H from passing backwards out of the decorative molding. First horizontal arm  264  and fifth horizontal arm  280  also press against opposing surfaces of L-bar L to provide a secure and stable connection of a molding to L-bar L. 
     Diagonal arm  262  provides a means for lifting first horizontal arm  264  and diagonal arm  266  a sufficient distance away from fifth horizontal arm  280  to permit hem H to exit the molding. 
     Pressure caused by the weight of a tile bearing down on second horizontal arm  268  transfers to press diagonal arm  266  and first horizontal arm  264  against the L-bar L. 
       FIG. 3  provides a front view for a main or cross-piece molding profile  120  of  FIG. 1B . Lower finger  128 , groove  130 , and upper finger  126  share a common rear segment  132 . Rear segment  132  is shown as vertical, but may also be at an incline. 
       FIG. 3  also shows a side edge  134  and a bottom edge  136  connected by a decorative pattern. The shape of the side edge  134 , decorative pattern, and bottom edge  136  may vary with aesthetics. However, the vertical distance of the combination, including upper edge  122 , comports with the vertical distance of the vertical sides  207 ,  228 ,  250 , and  270  of the perimeter moldings so that the main and cross piece moldings can aesthetically abut the perimeter moldings while also maintaining a substantially uniform ceiling height. 
       FIG. 4  shows a side view of a main molding piece  400 . The main molding piece  400  may be approximately six feet in length. When a standard size ceiling tile is used in a drop ceiling design, notches  406  or rabbets should be placed along the length of the upper edge  122 ′ of the main molding piece at sufficient distances to accommodate the overlap areas of main runners and cross T grids. The depth of notches  406  should be sufficient to accept the overlap areas without affecting the grip of the clip assembly. The notches may be formed, for example, by a dado blade. 
     As one non-limiting example, the main piece molding may have the following dimensions so as to accommodate standard two foot by two foot tiles. The material thickness may be 0.060+/−0.005 inches. The depth of the notch along notch wall  404  may be approximately 0.300 inches. First notches may be approximately 11.438 inches from opposing ends of the six foot length. At least one additional notch may be spaced 22.875 inches away from the inner ends of the first notches, while the notches may be 1.125 inches in width. A reasonable engineering tolerance of approximately 0.030 may be implemented for the notch widths, notch spacings, and overall molding lengths. However, the notch depth may benefit from having a minimum depth of 0.300 inches with a maximum overcut of 0.010 inches. 
     As shown in  FIG. 4 , main piece molding  400  may be butt cut on the end  408  to allow the main piece molding  400  to abut facing ends of other main piece moldings or to abut vertical sides  207 ,  228 ,  250 , or  270  of perimeter piece moldings. Bottom edge  136 ′ may be flush with the lower edges of other molding pieces in the ceiling assembly. 
       FIG. 5A  shows an example of a side view of a cross piece molding  500 . Upper edge  122 ″ does not include notches since the cross piece molding  500  typically spans between parallel main piece moldings  400 , which are typically a set distance apart. First end  506  and second end  508  are formed with coped ends to smoothly abut the decorative pattern of main piece moldings  400 . The coping may follow an inverse of the decorative portion pattern that allows first end  506  and second end  508  to receive a face of the decorative portion. Bottom edge  136 ″ is also at a vertical distance that is flush with other lower edges of other molding pieces in the ceiling assembly. 
       FIG. 5B  shows a side view of a peripheral cross piece molding  520 . Upper edge  122 ′″ does not include notches since the cross piece molding  500  typically spans between a main piece molding  400  and a perimeter molding, such as third perimeter molding  240 . The peripheral cross piece molding  520  typically spans between overlaps of suspension hardware, such as the joint formed when an L-bar intersects with a T-bar, or when a cross T-bar intersects with a main T-bar. 
     First end  526  is formed with a butt cut end to smoothly abut a perimeter molding. The butt cut end may be formed during installation of the peripheral cross piece molding  520  since the distance between main piece moldings  400  and perimeter moldings  200 ,  220 ,  240 , or  260  may vary. In addition, two peripheral cross piece moldings  520  may be abutted at their butt cut ends to span a section between main piece moldings  400 . 
     Second end  528  is formed with a coped end to smoothly abut the decorative pattern of main piece moldings  400 . The coping may follow an inverse of the decorative pattern that allows second end  528  to receive a face of the decorative portion. Bottom edge  136 ′″ is at a vertical distance that is flush with other lower edges of other molding pieces in the ceiling assembly. 
       FIG. 6  shows an example of a side view of a perimeter molding, such as third perimeter molding  240 . As an example, the perimeter molding  240  may be approximately six feet in length. An upper edge, formed by second horizontal arm  248  includes spaced notches  608  that also cut into vertical side  250 . The notches  608  are spaced at sufficient distances to accommodate the overlap areas of perimeter wall runner grids with cross T grids, which may comprise inter-fitting L-bars and T-bars. The depth of notches  608  should be sufficient to accept the overlap areas without affecting the grip of the snap-on assembly. Or, in the case of first and second perimeter molding designs  200  and  220 , the depth of the notches  608  should not interfere with the cooperation of respective vertical and horizontal arms. The notches may be formed, for example, by a dado blade. 
     As one non-limiting example, the perimeter molding may have the following dimensions. The material thickness may be 0.060+/−0.005 inches. The depth of the notch along notch wall  606  may be approximately 0.245 inches. First notches may be approximately 11.438 inches from opposing ends of the six foot length. At least one additional notch may be spaced 22.875 inches away from the inner ends of the first notches, while the notches may be 1.125 inches in width. A reasonable engineering tolerance of approximately 0.030 may be implemented for the notch widths, notch spacings, and overall molding lengths. However, the notch depth may benefit from having a minimum depth of 0.300 inches with a maximum overcut of 0.010 inches. 
     As shown in  FIG. 6 , perimeter piece molding  240  may be butt cut on the end  610  in order to abut facing ends of other perimeter piece moldings or to abut butt cut ends  526  of peripheral piece moldings. Lower edge, here formed by third horizontal surface  252 , may be flush with the lower edges of other molding pieces in the ceiling assembly. 
       FIG. 7  shows an example of a ceiling assembly in the process of installation. For simplicity, installed tiles, walls, and suspension means for T-bars are not shown. 
     In the example of  FIG. 7 , third perimeter piece molding  240  is snap-fit to L-bar L. Upper surface, at second horizontal arm  248 , extends upwards into the area concealed by the ceiling assembly. Lower edge, formed by third horizontal arm  252 , faces downward from the ceiling assembly. 
     Notches  608  permit T-bar T to pass through a portion of perimeter molding. Notch wall  606  abuts T-bar T, or is reasonably close to prevent a visual gap in the final installation. 
     The exterior of perimeter piece molding  240  is shown with substantially flat surfaces to allow butt cut ends of other perimeter piece moldings to abut the exterior. Butt cut ends of peripheral piece moldings  520  may also smoothly abut the flat surfaces of perimeter piece molding  240 . 
       FIG. 7  shows a peripheral piece molding  520  in the process of being installed. Upper surface  122 ′″ will extend upwards into the area concealed by the ceiling assembly. Bottom edge  136 ′″ will face downward from the ceiling assembly. First butt cut end  526  will abut vertical side  250  of perimeter molding and second coped end  528  will abut a portion of main piece molding  400 . Butt cut end  408  may, in other embodiments, connect to other portions of a ceiling assembly. 
     For instance, the length of peripheral piece molding  520  may be cut to a custom length to accommodate non-uniformly cut tiles or custom-cut tiles, such as may occur at the edges of a ceiling installation. The butt cut end  408  may abut a perimeter molding, or it may abut another butt cut end of a peripheral piece molding to accommodate a custom tile size in between main ceiling grids. 
     Cross piece molding  500  extends between first main piece molding  400  and second main piece molding  400 ′. First coped end  506  abuts first main piece molding  400 , and second coped end  508  abuts second main piece molding  400 ′. Bottom edge  136 ″ faces downward in the ceiling assembly. 
       FIG. 7  also shows a T-bar T extending through a notch in first main piece molding  400  and a notch  406  in second main piece molding. Notch wall  404  abuts T-bar T, or is reasonably close to prevent a visual gap in the final installation. 
     Turning now to formation methods for the molding system, while other formation methods may be used, the decorative molding may be extruded against a die to create a one-piece molding unit. The material for the molding may comprise composite wood, a synthetic composite, or a plastic such as PVC. 
     While the groove for the clip assemblies may be created during the molding process, the groove can be formed more precisely by cutting or etching the groove into the extruded molding to form the clip assembly. 
     The main piece molding can be fabricated to custom length, or it can be created to longer lengths and cut down to appropriate sizes, such as by sawing. For example, the main piece molding may be extruded to an initial 73 inch length and processed to create the clip assembly. Several pieces, for example, five, may be placed into a machining nest and fed into a set of saws that cut the extruded grooved pieces down to a 72 inch finished length. Simultaneously, three dado blade sets, or other cutting tools, may also cut the required notches. 
     The cross-piece molding  500  may be cut from an extruded grooved piece to a finished length of, for example 23.13 inches. The piece may then be cycled back and forth between two aligned punch units, which are connected by a rail, to form the opposed coped first and second ends  506  and  508 . Other alternatives are available to form the coped edges, such as a CNC machine equipped with a router bit, laser cutting, etc. 
     The peripheral edge molding  520  may be cut from an extruded grooved piece to a finished length of, for example 22.79 inches. The cutting may form a butt cut surface on butt cut end  526 , and the piece may then be punched to form coped end  528 . Other alternatives are available to form the coped end  528 , such as a CNC machine equipped with a router bit, laser cutting, etc 
     The perimeter molding can be fabricated to custom length, or it can be created to longer lengths and cut down to appropriate sizes, such as by sawing. For example, the perimeter molding may be extruded to an initial 73 inch length. Several pieces, for example, five, may be placed into a machining nest and fed into a set of saws that cut the extruded pieces down to a 72 inch finished length. Three dado blade sets, or other cutting tools, may then cut the required notches. 
     In the preceding specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various other modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. 
     For instance, the dimensions of the moldings may be adjusted to accommodate two foot by four foot tiles, or other tile sizes. The adjustment would entail adjusting notch spacings and may entail adjusting the finished lengths of the moldings. Other gridwork configurations can also be accommodated, and the L-bar and T-bar shown are not meant to be limiting. 
     Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.