Background of the Invention

This invention pertains to operable walls moveable to partition large rooms into smaller rooms, and, in particular, to a structural framework of an operable wall panel.

Operable walls or partitions, also known as moveable wall panel systems, find useful application in a variety of venues, such as classrooms, offices, convention facilities and hospitals. In these venues, the operable walls can be utilized to efficiently compartmentalize interior space into a multitude of separate, smaller rooms.

Standard operable wall panels are essentially constructed from a rectangularly configured structural frame and an exterior covering or skin. The skin covers the lateral, room-facing portions of the framework to provide the wall panel with a solid or continuous facade for the room. Various backing materials are known to be provided within the wall panel to impart desirable properties, such as sound barrier properties, to the wall panel.

The construction of existing structural frameworks typically involves linking separate, straight frame members into a rectangular shape. These frame members have been made of steel or aluminum and formed with a variety of different cross-sectional shapes. In one known construction technique, in order to link the frame members together, the frame members are first arranged in a desired rectangular configuration. The ends of the frame members may be mitered, or alternatively may be square and in abutting relationship with one another. After their arrangement, adjacent frame members are secured by additional angle brackets or gussets that are

welded or mechanically fastened with screws to the frame members at the various corners defined by the intersections of the members. These brackets were previously employed to ensure that the connection between the frame members was sufficiently strong and rigid to withstand the forces experienced by the structural framework during its normal use, especially those forces associated with movement of the wall panel between stacked and extended positions. However, the usage of these additional brackets to connect the frame members complicates assembly of the operable wall panel and therefore may be costly to the manufacturer.

Thus, it is desireable to provide a structural framework for an operable wall panel which can be readily assembled from separate frame members without requiring the use of additional bracketing between the frame members.

Summary of the Invention The present invention provides a structural framework for an operable wall panel constructed from frame members which interfit at their ends. The frame member ends are configured to fit together such that their flanges overlap, and the connection of the overlapping flanges results in a rigid structural framework that may be conveniently assembled.

In one form thereof, the present invention provides a structural framework for an operable wall panel moveable along a track in a wall stacking direction and a wall extending direction. The framework includes a top, a bottom, and opposite side frame members having ends which each include a connecting flange and a pair of flanges flanking the connecting flange. At their intersections which define the corners of the framework, the various frame members interfit and can be connected together in this interfitting arrangement. In particular, one of the frame members at each corner

includes a notch in its connecting flange that is sized to insertably receive the other frame member at that corner. When the frame members are so inserted or interfit together, portions of the flanking flanges of the various frame members at each corner are arranged in an overlapping relationship. The overlapping flanking flanges of the frame members are then connected together to thereby secure together the separate frame members of the structural framework. One advantage of the present invention is that a framework can be provided without requiring additional brackets be used to connect the frame members together.

Another advantage of the present invention is that a rigid framework for an operable wall panel can be readily assembled.

Brief Description of the Drawings The above mentioned and other advantages and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is a diagrammatic view of a operable wall panel system having panels with which the structural framework of the present invention may be employed;

Fig. 2 is a fragmentary front elevational view of one of the wall panels of the system of Fig. 1, wherein the wall panel structural framework is shown;

Fig. 3 is a perspective view of the portion of the structural framework encircled at 3 in Fig. 2;

Fig. 4 is an exploded perspective view of the structural framework portion shown in Fig. 3; and

Fig. 5 is an exploded perspective view of the side frame member and the bottom frame member of the structural framework.

Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent an embodiment of the invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention.

Description of the Preferred Embodiment The embodiment disclosed below is not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiment is chosen and described so that others skilled in the art may utilize its teachings.

Referring to Fig. l, there is diagrammatically shown an operable wall panel system with panels in which the structural framework of the present invention may be advantageously employed. The system includes operable partitions or wall panels 10, 11, 12, 13 and 14 suspended from track 16 by trolleys 18. Each of wall panels 10-14 is linked to the adjacent panels by multiple hinges 20 arranged along the panel height. Track 16 is mountable in the ceiling of a room to be compartmentalized. Panels 10-14 may be moved along the track, either manually or by a drive system not shown, in wall stacking and wall extending directions. Referring now to Fig. 2, there is shown a front view of the structural framework of panel 12. The framework, generally designated 25, is rectangular in shape and may be covered with a not shown metal skin. Framework 25 is assembled from top frame member 30, bottom frame member 31, and side frame members 32, 33. The interfitting connection of the ends of frame members 30- 33 described further below results in a rigid framework 25. Referring now to Figs. 3 and 4, the upper corner portion of framework 25 encircled at 3 in Fig. 2 is shown in assembled form and unassembled form respectively. In this embodiment, top frame member 30

is a U-shaped channel made of break formed steel. Top frame member 30 includes upper flange 37 and depending side flanges 38 and 39 that flank upper flange 37. The shown channel configuration is not necessary to the present invention, as other channels having flanking flanges, which can interfit with the side frame members, and a connecting flange that spans the flanking flanges, may be utilized. For example, an I-shape channel, formed by connecting a pair of generally C-shaped channels back- to-back, may be used as the top frame member. The cross- sectional shape of top member 30 is uniform along its length, but could be alternatively formed.

Right side frame member 33, which is uniformly shaped along its height, is made by roll forming steel having a nineteen gauge thickness. This thickness is less than steel thicknesses which were frequently used previously in frameworks as the interfitting frame member connection provides rigidity to framework 25. Previously this rigidity needed to be provided by the materials of construction. The lesser thickness reduces the weight of framework 25 and thereby panel 12, making panel 12 easier to maneuver and operate.

In this embodiment, side frame member 33 includes a planar inward or connecting flange 42, flanking side flanges 45, 46, and outward facing stepped lips 48, 50.

Lips 48, 50 serve as attachment points for the panel skin not shown in Figs. 3 and 4. As with top frame member 30, other channel configurations having flanking flanges and a connecting flange may be substituted for the shown configuration of side frame member 33. At its upper end, notch 43 (See Fig. 4) is formed in inward flange 42. Side frame member 33 and notch 43 are particularly sized to insertably receive the right end of top frame member 30. The explanation herein with respect to the configuration and assembly of right side frame member 33

also applies to left side frame member 32, which is a mirror image of right side frame member 33.

The interfitting connection of top frame member 30 to right side frame member 33 during assembly of framework 25 begins with the components arranged as shown in the exploded view of Fig. 4. The end of top frame member 30 is then inserted into notch 43. Additional notches 49, 51 in lips 48, 50 accommodate side flanges 38, 39 to allow top frame member end face 40 to be flush with lips 48, 50 after frame member insertion. The upper regions of side flanges 45, 46 of side frame member 33 overlap and closely flank the inserted side flanges 38, 39 of top frame member 30.

After insertion, the overlapping side flanges are connected together to secure top frame member 30 and side frame member 33 in the arrangement shown in Fig. 3. A preferred connection involves conventional spot welding techniques to weld side flange 45, 46 to inserted side flanges 38, 39 respectively. Alternative connection techniques, including mechanical fasteners such as screws inserted into the overlapping flanges, may also be used within the scope of the invention.

The construction of bottom frame member 31 and its connection to side frame members 33 will be understood by referring to Fig. 5. Bottom frame member 31 is made of break formed steel in a hat-shape configuration. Alternate shapes may also be utilized. Bottom frame member 31 includes top flange 54 and depending flanking flanges 55, 56 that end in horizontal sections 57, 58 coextensive with lips 48, 50. Downwardly opening interior cavity 60 of frame member 31 may accommodate a drop seal known in the art.

The assembly of bottom frame member 31 with right side frame member 33 is similar to the assembly of top frame member 30 with frame member 33. Bottom frame member 31 inserts through notch 44 provided in right side

frame member 33 such that the side frame member flanges 45, 46 overlap flanges 55, 56. Notch 44 is substantially equal to the height of flanges 55, 56. Notches 52, 53 in lips 48, 50 allow full insertion of bottom frame member 31. Rigid connection between the frame members is preferably accomplished with welding.

While the connections at all four framework corners between frame members 30-33 are preferably of the interfitting variety disclosed herein, conventional connection techniques may be employed at some of the corners if desired by the manufacturer. In addition, although the notching of the connecting flanges was shown herein as occurring in the vertical frame members, it will be appreciated that notches could alternatively be provided in the horizontal frame members provided the widths of the frame members were varied to allow the proper overlapping of the flanking flanges. While framework 25 constructed by the inventive technique is sufficiently rigid for many operations, in other applications additional gussets could be introduced to further strengthen framework 25.

While this invention has been described as having a preferred design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.