Background of the Invention Ceiling grid systems, comprised of horizontal runners for supporting tile panels such as acoustical ceiling tiles, are used extensively in both new and remodeled building and room structures. The grid typically comprises main runners and cross-tees, having lateral supporting shoulders or flanges, that are arranged perpendicular to each other to form a rectangular pattern. The runners most typically are suspended by a wire connected to an existing ceiling or exposed framing member, and the cross-tees are attached or mounted to the runners in a perpendicular direction to form a rectangular pattern. Less frequently, the grid is installed without suspension by nailing the runners directly to the ceiling or framing members, and then connecting the cross-tees normal to the runners.

After the grid is installed, the tile panels are eased into place onto the supporting flanges of the runners and cross-tees. A grid system offers many advantages such as increasing a room's energy efficiency, improving a room's acoustics, and enhancing the aesthetic value of a room. Some suspended ceiling grid systems are advantageous in that they provide means for lowering a ceiling, and/or allowing for the installation of electrical fixtures, pipes and duct work.

Ceiling grid systems are relatively inexpensive and easy to install as compared to a plaster ceiling. As a consequence, there is a continuing need to improve on the design and integrity of the grid system, particularly in light of the fact that many systems are installed in commercial buildings requiring years of service, or installed by the do-it-yourself home owner.

Summary of the Invention The invention provides a surface mounted grid system for use in association with a substructure and for supporting an array of tile panels. The surface mounted grid system includes a plurality of main runners and a plurality of cross runners adaptable for spaced, horizontal disposition. The main runners are adaptable for attachment to the substructure and include a horizontally-oriented surface having longitudinal edges, at least one longitudinal member depending transversely from the horizontally-oriented surface at a point, a shoulder having a longitudinal edge and extending outwardly from the at least one longitudinal member, and a downwardly depending side wall. The longitudinal edges of the horizontally-oriented surface extend outwardly a greater distance from the downwardly depending side wall than the longitudinal edge of the shoulder. The horizontally-oriented surface has at least one opening defined therein at a location between the point and the longitudinal edge of the horizontally-oriented surface that is closest to the point.

The invention also provides a surface mounted grid system that includes a plurality of main runners and a plurality of cross-runners adapted for spaced, horizontal disposition.

At least one of the main runners is attachable to the substructure and includes a top member and a bottom member. The top member includes a horizontally-oriented surface and the bottom member includes a horizontally-disposed flange and a web extending upwardly therefrom. The cross-runners are arranged substantially perpendicular to the

main runners and include a horizontally-disposed flange and a web extending upwardly from the horizontally-disposed flange. The flange of the main runners and the flange of the cross-runners are disposed to support tile panels in a common plane. At least one of the main runners or the cross-runners include means for passing one or more power or telecommunication lines through the surface mounted grid system.

The invention further provides a surface mounted grid system that includes a plurality of main runners and a plurality of cross-runners adapted for spaced, horizontal disposition. The main runners are attachable to the substructure and include a horizontally-oriented surface and a downwardly depending web terminating with a horizontally-disposed flange. The cross-runners are arranged substantially perpendicular to the main runners and include a horizontally-disposed flange and a web extending upwardly therefrom. The flange of the main runners and the flange of the cross-runners are disposed to support tile panels in a common plane. At least one of the main runners and the cross-runners include at least one aperture defined therein. The at least one aperture is shaped and dimensioned to receive one or more power or telecommunication lines therethrough.

The invention further yet provides a method of installing a surface mounted grid system and passing one or more power or telecommunication lines therethrough. The method includes providing a plurality of main runners and a plurality of cross-runners.

The main runners include a horizontally-oriented surface and a web extending therefrom and terminating with a horizontally-disposed flange. The cross-runners include a horizontally-disposed flange and a web extending upwardly therefrom. The flange of the main runners and the flange of the cross-runners are disposed to support tile panels in a common plane. The method also includes attaching the main runners to the substructure, arranging the cross-runners substantially perpendicular to the main runners, and passing

one or more power or telecommunication lines through at least one aperture defined in at least one of the main runners and cross-runners.

Brief Description of the Drawings Fig. 1 is a perspective view, looking upward, of a ceiling grid system comprising a main runner and a cross-runner of the present invention.

Fig. 2 is an exploded perspective view showing in more detail an upper and a lower member of a runner employed in the grid system of the invention.

Fig. 3 is an elevation end view showing the members of Fig. 2 after assembly.

Fig. 4 is a perspective view, looking downward, of the ceiling grid system of Fig.

1.

Fig. 5 is an exploded perspective view showing a modified embodiment of the upper and lower members of a runner of the present invention.

Fig. 6 is an elevation end view showing the members of Fig. 5 after assembly.

Fig. 7 is a perspective view of a top member of a main runner showing another modified embodiment of the invention.

Fig. 8 is an elevational end view showing assembly of the top member of Fig. 7 and a bottom member.

Fig. 9 is an elevational view, partially in cross-section, showing the assembly of the top member of Fig. 7 with a cross-runner.

Fig. 10 is a partial sectional view along line 10-10 in Fig. 9.

Fig. 11 is a perspective view of the embodiment of Figs. 7-10 showing the main runner and cross-runner after assembly.

Fig. 12 is a perspective view of a top member of a runner showing another modified embodiment of the invention.

Fig. 13 is an elevational end view showing assembly of the top member of Fig. 12 and a bottom member.

Fig. 14 is a perspective view of a bottom member of a runner showing another modified embodiment of the invention.

Fig. 15 is an elevational end sectional view of the bottom member of Fig. 15 showing the assembly of the runner.

Figs. 16-21 are perspective views, each illustrating a modified embodiment of a bottom member of a runner.

Figs. 22-27 are perspective views, each illustrating a modified embodiment of a top member of a runner.

Fig. 28 is a plan view of a ceiling of a room showing the principal steps for a process of installation.

Before an embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of"including", "comprising"and"having"and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

Detailed Description Referring to the drawings, wherein the same reference numerals refer to similar parts throughout the several views, Fig. 1 shows a grid system 10 of the present invention

installed on a ceiling and supporting ceiling tiles 12. Although the grid system 10 is described and illustrated with particular emphasis on a system to support ceiling tiles 12, it should be understood that the grid system 10 can support any tile or panel other than ceiling tiles. In accordance with one embodiment of the invention, the grid system 10 comprises a plurality of main runners 14 and cross-runners 16 disposed substantially perpendicular to the main runners 14. The main runners 14 are spaced at predetermined distances in parallel rows, and the cross-runners 16 are similarly spaced in parallel rows normal to the main runners 14, thereby forming a rectangular grid for supporting the tiles 12. As shown in Fig. 1, the main runners 14 are affixed or fastened to a substructure such as a wooden joist 18, or similar framing member, by any suitable means such as nails, screws, or the like. It should be understood, however, that the substructure can also be, but not limited to, ceilings or walls. Also, for some installations it may be better or more appropriate to mount the cross-runner 16 to the substructure, but this will depend on such factors as the construction and lay-out of the substructure, room dimensions, and tile size.

Further, if the grid is attached to a plaster ceiling (not shown), it is more desirable to use anchor bolts or the like. Wall angle bracket or wall molding 20 is attached to a wall 22 at or near the edges of the ceiling (in practice, the molding is attached to all the walls of the room) and at about the same height as the runners, and supports the runners and ceiling panels at the edges. The wall molding may be of any conventional construction, and typically comprises a vertical backing plate and a horizontal flange. Thus, the wall molding is properly aligned, and the backing plate is attached to the wall by such means as nailing or the like. The horizontal flange supports the panels and runners.

Figs. 2-4 show greater details of the runners and the assembly of the members.

The main runner 14 and cross-runner 16 are generally of similar structure and, therefore, the description of one type is applicable to the other unless otherwise noted. The runners

are typically made of plastic, metal, or other materials that are well known and used for ceiling grid systems. As best seen in Fig. 2, runner 16 comprises a top member (e. g. crosspiece) 24 and complementary bottom member 26. The top member 24 has a substantially flat, elongated backing 28 adaptable to be affixed or mounted to the substructure, such as joist 18, such as by nailing or the like. Desirably, the backing 28 is prepunched with openings or holes 30 to accommodate nails or screws. Depending downwardly from the backing 28 are two spaced, non-peripheral side walls 32 which run about the complete longitudinal length of the backing 28, and preferably are co-terminus therewith, although they need not be. The side walls 32 are flexible, either by being formed of a flexible material, and/or being of such a gauge as to exhibit flexibility. The side walls 32 form a longitudinal channel 34 for receiving the bottom member 26, as described below in greater detail. Preferably, the side walls 32 are parallel, but where desired the walls may converge slightly in order to provide for better retention of the lower member. Further, both side walls 32 are provided with inwardly extending protrusions or detents 36 at or adjacent the terminus of the walls 32. The detent 36 preferably has an inwardly disposed, planar shoulder 37 which is substantially perpendicular to the side wall 32, for reasons explained below. Additionally, the backing 28 of the top member 24 of the main runner 14 has a plurality of spaced notches 38 (see Fig. 4) adaptable to receive the side walls 32 of the top member 24 of the cross-runner 16 when, upon assembly of the runners, the cross-runner 16 is arranged perpendicular to the main runner 14.

Bottom member 26 of both runners is substantially T-configured in cross-section, and comprises a flange 40 for supporting a tile panel 12 and an intermediate transverse web 42 extending longitudinally therefrom. Projection, boss or barb 44 at or adjacent the outer terminus of the web 42 extends for substantially the complete longitudinal length

thereof, and preferably is co-terminus therewith. Preferably, the underside of the projection 44 has a planar shoulder 45 which is substantially perpendicular to the web 42.

The runners 14 and 16 are assembled substantially as shown in Figs. 3 and 4. The backing 28 of the top runner 24 of the main runner 14 is first nailed or screwed to the substructure, e. g., ceiling joist 18. The bottom member 26 of the main runner 14 is then conjoined with the top member 24 by inserting the web 42 into the channel 34, and then slowly retracting the bottom member 26 until the shoulder of projection 44 seats on the detent 36. The engagement of these two members is clearly illustrated in Fig. 3. It will be observed that the tile supporting flange 40 of the bottom member 26 and the backing 28 of the top member 24 define a groove, recess or rabbet adaptable to receive a tile panel 12.

Thus, the cross-runners 16 are similarly engaged, and the cross-runners 16 are then assembled with the main runners 14 as shown in Fig. 4. In other words, the cross-runners 16 are installed perpendicularly to the main runners 14 by inserting the channel walls 32 into the notches 38. The backing 28 of the main runner 14, and desirably the transverse edge of flange 40 of the bottom member 26 of the cross-runner 16 abuts the longitudinal edge of flange 40 of the bottom member 26 of the main runner 14. Tile panels 12 are then eased into position and the bottom members 26 of both runners may be adjusted to accommodate the thickness of the tile. It will be observed that the tile panels 12 lay substantially in a common plane with the flanges of the main and cross-runners.

In accordance with an alternative embodiment shown in Figs. 5 and 6, the protrusion or detent 36 protruding from the internal channel walls 32 is disposed inwardly from the terminal edge of the walls 32. Positioning the detents 36 inwardly from the edge may provide a detent that is stronger than a terminal detent, and may allow for easier adjustment of the bottom member. In conjunction with this embodiment, the web 42 of the bottom member 26 may be provided with a second projection or boss 48. When the

members are assembled substantially as described above and as shown in Fig. 6, it will be observed that the second projection 48 substantially borders or abuts the internal walls 32 of the channel 34. This feature is especially advantageous in that it inhibits rocking of the bottom member 26. hi another embodiment of my invention as shown in Figs. 7-11, the main runner 14 includes a top member 24 and a bottom member 26, substantially as described above, but the cross-runner comprises solely the bottom member 26. Accordingly, there is shown a top member 24 having a backing 28 and downwardly depending walls 32 forming channel 34, as described above with reference to the other embodiments. Longitudinal members or flanges 60 depend downwardly from the backing 28 and on opposed sides of the channel walls 32 so as to be spaced therefrom. Lateral shoulders 62 include a longitudinal edge and project or extend transversely and outwardly from the flanges 60, but the longitudinal edges of the shoulders 62 do not extend beyond the longitudinal edges of the backing 28.

The longitudinal edges of the shoulders 62 can coterminate with the longitudinal edges of the backing 28, as best seen in Figs. 8 and 9. As used herein, the terms"upwardly"and "downwardly"refer to directions toward and away from the ceiling or substructure, respectively. As used herein, the terms"outwardly"and"inwardly"refer to directions away from and toward a center of the runners (main or cross), respectively. The center of the runners can be defined by an imaginary vertical axis that extends through the horizontal midpoint of the backing 28 in the main runner and through the horizontal midpoint of the flange 40 of the cross-runner. It will be observed that shoulder 62 is spaced below the backing 28 and substantially parallel thereto so as to be laterally disposed with reference to the backing 28, thereby defining or forming re-entrant groove, recess or rabbet 64. Further, shoulder 62 is formed of a flexible resilient material (e. g., plastic). A plurality of spaced notches 66 (see Figs. 7 and 8) is formed in the shoulders 62

adaptable to receive the web 42 of the bottom member 26 when arranged perpendicular to the top member 24 of the main runner 14. In order to provide a suitable connection between the two members, the terminus of web 42 has barb 68, which preferably has a substantially planar surface 70 for mating engagement with the planar surface of shoulder 62. The notch 66 is slightly smaller than the width of the projection or barb 68, and because the shoulder 62 is fabricated of a flexible material, such as a plastic, the notches can be spread to admit the projection or barb 68, and the bottom member 26 can then be pulled downwardly to bring the planar surfaces into mating engagement. Thus, the overlapping engagement of the planar surfaces of the projection 68 and of the shoulder 62 provides support for the cross-runner 16, and prevents undesired disengagement of the members. Where desired, opposed lateral shoulders 72 are formed on web 42 spaced inwardly from the barb 68 of a distance slightly greater than the thickness of shoulder 62 of the top member 24. Thus, upon assembly the barb 68 is inserted into the notch 66, and the lateral shoulders 72 abut or nearly abut the undersurface of the shoulder 62 of the top member 24, thereby inhibiting any rocking of the bottom member 26.

Upon assembly of the members of this alternative embodiment shown in Figs. 7- 11, the top and bottom members 24 and 26 of the main runner 14 are engaged and interlocked, as shown in Fig. 8 and as described above with reference to the other embodiments. The bottom member 26 of the cross-runner 16 is brought into perpendicular arrangement with the main runner 14 at the notches 66, which receives the web 42 of the cross-runner 16 such that the planar surface 70 of barb 68 overlaps with the shoulder 62.

Hence, the groove or recess 64 defined by the shoulder 62 and the backing 28 of the top member 24 of the main runner 14 holds the cross-runner 16 firmly in place. Also, when the members are assembled, the transverse edge of flange 40 of the bottom member 26 of the cross-runner 16 is brought into abutment with the longitudinal edge of flange 40 of the

bottom member 26 of the main runner 14. Thus, the flanges 40 of both runners are in a common plane, and when the grid system 10 is complete and the tile panels 12 are eased into place, the tiles 12 likewise are disposed in a common plane. Because the grid system 10 is characterized by high integrity, the ceiling is now secure.

Figs. 12 and 13 show a modified and preferred embodiment of the top member 24 of the main runner 14. The backing 28 of the top member 24 is wider than the backings of the embodiments discussed above, such that, the backing 28 in the modified and preferred embodiment extends outside (to the left and the right as illustrated in Figs. 12 and 13) the longitudinal edges of the shoulders 62. Accordingly, the longitudinal edges of the shoulders 62 are no longer co-tenninus with the longitudinal edges of the backing 28 as discussed in the embodiments above. The backing 28 may also be wider than the flange 40 of the bottom member 26 of the main runner 14, although that is not required. The pre- punched holes 30 are defined in the backing 28 of the top member 24 and are positioned outside of the shoulders 62 so that a tool, such as a screw driver, a power drill, a ratchet or a wrench, can access the holes 30 and the fasteners positionable therein when the top and bottom members 24 and 26 are assembled. In other words, the holes 30 are defined in the backing 28 in a position between the longitudinal edge of the shoulder 62 and the longitudinal edge of the backing 28. In some previously discussed embodiments, the holes 30 are positioned between the side wall 32 and the flange 60 making it difficult to access the holes 30 and fasteners positionable therein with a tool when the top and bottom members 24 and 26 of the main runner 14 are assembled.

As introduced above, surface mounted grid systems are directly mounted to substructures. Unlike suspended ceiling grid systems that are suspended a distance below the substructures and provide space thereabove, surface mounted grid systems generally provide little or no space thereabove to run or extend one or more power or

telecommunication lines 74. As used herein, the term"power or telecommunication lines" is meant to refer to, but not be limited to, an electrical line, a telephone line, a computer line or any other communication, data transferring, or power line. The embodiments set forth in Figs. 14-27 show a variety of ways by which one or more power or telecommunication lines may be installed or strung through the surface mounted grid system 10.

Referring to Figs. 14-21, a modified embodiment of the bottom member 26 of either or both the main runner 14 and cross-runner 16 is illustrated in Figs. 14 and 15 and each of Figs. 16-21. Like reference numerals are used in the modified embodiments to show like components. The bottom member 26 in each modified embodiment includes at least one aperture 73 for allowing one or more power or telecommunication line 74 to pass through or along the surface mounted ceiling grid system 10. The term"aperture"as used in the specification and the claims in relation to passing one or more power or telecommunication line 74 through or along a surface mounted ceiling grid system means an opening, a slot, a gap, a hole, a recess, a channel or anything else that partially or fully allows power or telecommunication lines 74 to pass through or run along a surface mounted ceiling grid system.

Referring now to Figs. 14 and 15, a modified embodiment of the bottom member 26 of the main runner 14 is illustrated. Although the bottom member 26 illustrated in Figs.

14 and 15 is used in combination with a top member 24 of the main runner 14, the bottom member 26 illustrated can also be a bottom member 26 of a cross-runner 16. In fact, the aperture arrangement (discussed in more detail below) of the embodiments shown in Figs.

14-21 may be used in conjunction with the bottom member 26 of a main runner 14 or a cross-runner 16. The bottom member 26 includes apertures 73 defined in the web 42. The apertures 73 allow one or more power or telecommunication line 74 to pass through the

web 42 and, therefore, through the grid system 10. When the top and bottom members 24 and 26 are assembled and tiles 12 are placed on the flanges 40 of the bottom member 26 (see Fig. 15), the apertures 73 are positioned below the side walls 32 of the top member 24 and above the tiles 12 so that one or more power or telecommunication line 74 can easily pass through the grid system 10 without being obstructed.

As shown in Fig. 16, the aperture 73 is defined in the projections 44 and 48 and the web 42. When the bottom member 26 is assembled to the top member 24 (not shown) and the tiles 12 are positioned on the flanges 40, the aperture 73 is positioned such that a portion of the aperture 73 is positioned between the top of the tile 12 and the bottom of the side walls 32 of the top member 24 so that one or more power or telecommunication line 74 can pass through the aperture 73 and, therefore, through the grid system 10.

Referring to Fig. 17, the bottom member 26 includes two channels 76, one positioned on each side of the web 42. In this embodiment, tiles 12 are placed on top of flange 40 and are supported on the sides by the channels 76 rather than by the web 42, as discussed in other embodiments. Each channel 76 of the bottom member 26 defines an aperture 73 therein that one or more power or telecommunication line 74 can pass through and, therefore, pass through the grid system 10.

Referring now to Fig. 18, the bottom member 26 includes a channel 78 positioned between the web 42 and the flange 40. When tiles 12 are assembled with the main runners 14 and cross-runners 16 in this embodiment, the flange 40 supports the tile 12 from below and the channel 78 supports the tile 12 from the side. The aperture 73 is defined in the channel 78 such that one or more power or telecommunication line 74 can pass therethrough and, therefore, can pass through the grid system 10.

As shown in Fig. 19, the bottom member 26 includes a channel 80 positioned on a bottom surface of flange 40. The channel 80 defines an aperture 73 therein that one or

more power or telecommunication line 74 can pass through and, therefore, pass through the grid system 10. Flange 40 supports the tiles 12 from below and the web 42 supports the tiles 12 from the side.

Referring to Fig. 20, the bottom member 26 includes channels 82 positioned on a top surface of the flange 40. Each channel 82 defines aperture 73 therein that one or more power or telecommunication lines 74 can pass through and, therefore, can pass through the grid system 10. In this embodiment, the top surface of the channels 82 support the tiles 12 from below and the web 42 supports the tiles 12 from the side.

Referring now to Fig. 21, the bottom member 26 includes channels 84 positioned on both sides of the web 42 and a pre-determined distance above the flange 40. Each channel 84 defines an aperture 73 therein that one or more power or telecommunication lines 74 can pass through and, therefore, can pass through the grid system 10. When the tiles 12 are assembled with the main runners 14 and the cross-runners 16, the flange 40 supports the tiles 12 from below and the web 42 supports the tiles 12 from the sides. The tiles 12 are also positioned between the channels 84 and the flange 40.

Referring to Figs. 22-27, a modified embodiment of the top member 24 of the main runner 14 is illustrated in each of Figs. 22-27. Like reference numerals are used in the modified embodiments to show like components. The top member 24 in each modified embodiment includes at least one aperture 73 for allowing one or more power or telecommunication lines 74 to pass through or along the surface mounted ceiling grid system 10. The aperture arrangements set forth in Figs. 22-27 may be applied to any of the top member embodiments discussed herein, but are preferably used in conjunction with the embodiment of Figs. 12-13 and 15.

Referring now to Fig. 22, the apertures 73 are defined in both side walls 32 so that one or more power or telecommunication line 74 can pass through the top member 24 and,

therefore, can pass through the grid system 10. The apertures 73 are positioned so that one or more power or telecommunication lines 74 can pass through the apertures 73 without interfering with the projection 44 of the bottom member 26 when the top and bottom members 24 and 26 are assembled.

As shown in Fig. 23, the apertures 73 are defined in the side walls 32 from the bottom of the side walls 32 to a location prior to the backing 28 to form a slot that one or more power or telecommunication lines 74 can pass through. The top of the apertures 73 are defined in the side walls 32 at a location above the projection 44 of the bottom member 26 when the top and bottom members 24 and 26 are assembled.

Referring to Fig. 24, the aperture 73 is defined in combination by the side walls 32 and a horizontally disposed wall 86. The aperture 73 may or may not be further defined by a horizontally disposed top wall. In fact, in all of the aperture arrangements related to the top member, the aperture 73 may or may not be defined by a top wall, regardless of what is specifically shown in the Figures. One or more power or telecommunication lines 74 pass through the aperture 73 and can be supported from below by the horizontally disposed wall 86.

Referring now to Fig. 25, one or more apertures 73 are defined in combination by the flanges 60, the shoulders 62 and vertically disposed walls 88. Two apertures 73 are shown in Fig. 25. The walls 88 are positioned a distance in from the end of the shoulders 62 so that the barb 68 of the cross-runner 16 can engage the shoulder 62 within the recess 64 to connect the cross-runner 16 to the main-runner 14. One or more power or telecommunication lines 74 can pass through the apertures 73.

As shown in Fig. 26, one or more apertures 73 are defined in combination by the side walls 32, the flanges 60 and the shoulders 62. Two apertures 73 are shown in Fig. 26.

Like the embodiment in Fig. 25, the walls 90 are disposed in from the ends of the

shoulders 62 to facilitate connection of the cross-runner 16 to the main runner 14 (as discussed above). One or more power or telecommunication lines 74 can pass through the apertures 73.

Referring to Fig. 27, the aperture 73 is defined in combination by the backing 28, vertically disposed walls 92 and a horizontally disposed wall 94. Flanges 60 and shoulders 62 are positioned under the aperture 73 and facilitate connection between main runners 14 and the cross-runners 16 (as discussed above). One or more power or telecommunication lines 74 can pass through the aperture 73.

Now that the structure of the top and bottom members 24 and 26 have been discussed with regards to passing one or more power or telecommunication lines 74 therethrough, installation and passage of one or more power or telecommunication lines 74 through the apertures 73 of the top and bottom members 24 and 26 will be discussed.

Referring to the embodiments illustrated in Figs. 14-21, the bottom member 26 may be used with a main runner 14 and/or a cross-runner 16 (as discussed above). In applications where the bottom member 26 is used with a main runner 14, the grid system 10 is installed and one or more power or telecommunication lines 74 are passed therethrough by first mounting the top member 24 of the main runner 14 to the substructure, such as the joist 18. The top member 24 can be mounted to the joist 18 by inserting and driving fasteners through holes 30 in the backing 28 of the top member 24 and into the joist 18 by a tool. The procedure for installing the main runner 14 and passing one or more power or telecommunication lines 74 therethrough has two different options after the top member 24 has been mounted to the joist 18.

On one hand, the bottom member 26 can be mounted to the top member 24 (as discussed above). Then, one or more power or telecommunication lines 74 can be passed through the apertures 73 in the bottom member 26. Finally, the cross-runners 16 are

arranged substantially perpendicular to the main runners 14 and the tiles 12 are positioned on the flanges 40 of the runners 14 and 16.

On the other hand, the one or more power or telecommunication lines 74 can be passed through the apertures 73 in the bottom member 26 prior to mounting the bottom member 26 to the top member 24. Finally, the cross-runners 16 are arranged substantially perpendicular to the main runners 14 and the tiles 12 are positioned on the flanges 40 of the runners 14 and 16.

In applications where the bottom member 26 is used with the cross-runner 16, the grid system 10 is installed and one or more power or telecommunication lines 74 are passed therethrough by first mounting the top member 24 of the main runner 14 to the joist 18. The bottom member 26 of the main runner 14 is then mounted to the top member 24.

The bottom member 26 of the cross-runner 16 can be used in combination with a top member 24 of the cross-runner 16 as illustrated in Figs. 2-4 or the bottom member 26 can be used alone as illustrated in Figs. 9-11, which will be discussed further herein. The procedure for installing the cross-runner 16 and passing one or more power or telecommunication lines 74 therethrough has two different options after the main runner 14 has been mounted to the joist 18.

On one hand, the bottom member 26 of the cross-runner 16 can be arranged substantially perpendicular to and mounted to the main runner 14 (as discussed above).

The one or more power or telecommunication lines 74 can then be passed through the apertures 73 in the bottom member 26. Finally, the tiles 12 are positioned on the flanges 40 of the runners 14 and 16.

On the other hand, one or more power or telecommunication lines 74 can be passed through the apertures 73 in the bottom member 26 of the cross-runner 16 prior to arranging the cross-runner 16 substantially perpendicular to the main runner 14 and mounting the

cross-runner 16 to the main runner 14. Finally, the tiles 12 are positioned on the flanges 40 of the runners 14 and 16.

Referring to the embodiments illustrated in Figs. 22-27, the top member 24 includes at least one aperture 73 that allows one or more power or telecommunication lines 74 to pass through the grid system 10. One or more power or telecommunication lines 74 can be passed through the aperture 73 in the top member 24 before or after any of the following installation steps. The top member 24 is mounted to the substructure, such as the joist 18, by inserting and driving fasteners through holes 30 of the top member 24. The bottom member 26 of the main runner 14 is then mounted to the top member 24 of the main runner 14 (as discussed above). The cross-runner 16 is then arranged substantially perpendicular to the main runner 14 and mounted thereto. Finally, tiles 12 are positioned on flanges 40 of the runners 14 and 16.

By reason of the structural features of the grid system and the cooperation of the runner members, installation of the grid system of my invention is greatly simplified and installation can be accomplished in substantially less time as compared to a conventional system for a suspended ceiling. For example, in a typical prior art suspended ceiling system, a plurality of spaced apart lines are run (or a chalk line snapped) usually perpendicular to the joist to mark the locations of the main runners. Reference strings are suspended between opposed walls of the room, and hanger wires for suspending the main runners are attached to the joists directly above the reference strings. The main runners, which are suspended by the hanger wires, are positioned so that the cross-runners will align with the reference strings when the cross-runners are connected to the main runners.

When all the main runners are up and suspended by the hanger wires, and also supported at the ends by a suitable angle bracket, the cross-runners are then connected to the main runners, thereby completing the grid.

In accordance with the installation process of my invention, the cross-runners 16 extending between the main runners 14 typically are of equal length. As shown in Fig. 28, a first line 96 is run, drawn or otherwise formed substantially parallel to a wall 98 of the room, which typically would be perpendicular to the joists 100, which extend between walls 98 and 102, and at a predetermined distance from the wall of the room. This predetermined distance is preferably the distance from the wall 98 to the first main runner, which is the length of a cross-runner or less if necessary or desirable to provide for border panels on opposite sides of the room of equal size. A second line 104 is run, drawn, or otherwise formed substantially normal to the first line 96 so as to be in alignment with a notch of the top member of the main runner when the main runner is attached to the substructure (e. g., joist). The adjoining wall 106 is marked (as with a pencil marking) at spaced intervals about equal to the length of a cross-runner. This measurement need not be precise because the distance between main runners is determined by the length of the cross-runners, and as stated above the cross-runners extending between the main runners are of equal length. A main runner is then attached to the substructure along the first line 96 and between opposed walls 106 and 108.

One end of a cross-runner is connected to the main runner attached to the substructure, and a second main runner is positioned at the opposite end of this cross- runner and in substantial alignment with a wall marking. The second main runner is then attached to the substructure, and the remaining cross-runners for that row are connected to the first and second main runners. These steps are then repeated until the grid system is completed. At any time during the installation, the cross-runners extending between the wall and adjacent main runners at each end of the room may be connected at one end to the main runner and at the other end but against an angle bracket, wall bracket or other suitable support means (not shown) attached to the wall at ceiling height, as explained

above. When the cross-runners are arranged substantially perpendicular to the main runners, the horizontally disposed flanges of the cross-runners are in a common plane with the flanges of the main runners, and the flanges of the main runners and the flanges of the cross-runners support the tile panels in a common plane, as explained above. It thus will be observed that two lines only are drawn, regardless of the size of the room, and additional items or steps such as reference strings and hanger wires, and the positioning of these items, and the need for precise measurements are eliminated. As a consequence, installation of the grid system is simplified, and the time for installing the system is substantially reduced.

It will be observed that by reason of my invention numerous advantages are achieved with the ceiling grid system. Thus, the invention provides a ceiling grid system of generally modular construction that is easy to install, that can support tile panels of varying thicknesses, and that provide a rugged and secure system. In addition, it will be observed that because the several members are snap fit, it is possible to snap and unsnap the grid system not only during installation but after the ceiling is in place, such when replacing a soiled or damaged tile. Further, it should be understood that the foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

The present invention also provides a surface mounted ceiling grid system that is attachable and detachable form a substructure when the top member and the bottom member are assembled. This is provided by the holes 30 for mounting the main runner to the substructure are positioned outside of the longitudinal edges of the shoulders 62, therefore, being positioned so that a tool can access the fasteners positionable in the holes 30.

The present invention further provides a surface mounted grid system that one or more power telecommunication lines can pass through.

The embodiments described above and illustrated in the figures are presented by way of example only and not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention.

U. S. Patent No. 6,205, 732 issued to Rebman and U. S. Patent No. 5,611, 185 issued to Wilz, each of which pertain to surface mounted grid systems are hereby fully incorporated by reference. In the case of conflicts between the present disclosure and the incorporated patents, the present disclosure should control.