Lateral Load Transfer System for Operable Walls

1. Field of the Invention

The subject invention relates to movable partitions, also known as operable walls and, more particularly, to an improved operable wall system providing improved response to lateral loads.

2. Description of Related Art

Operable walls, particularly those used to divide large spaces such as convention centers, ballrooms, and gymnasiums, may be subjected to lateral loading of the wall panels as a result of earthquake or pressure differential between the rooms divided by the operable walls. The wall panels in question can have dimensions of up to 5 feet wide and up to 40 feet high. Loads can reach on the order of 20 pounds per square foot (psf). Based on 5'.times.40' panel dimensions, and 20 psf, the load to be resisted at the top and at the bottom of the panel is 2,000 pounds.

Such significant lateral loading can occur, for example, between spaces divided by an operable wall in an exhibit area where one of the rooms is adjacent to an exterior wall containing large doors which may be opened during windstorms. The resultant pressure differentials may be large enough to cause suspension components to break and the walls to collapse. The ability of the operable wall panels to resist large lateral loads is limited by the relatively small-diameter, cylindrically-shaped trolley pendent bolts which suspend the operable wall panels from their overhead guide tracks.

Sliding of the bottom of the panels in response to lateral loads also constitutes a safety hazard for occupants of the space near the panels. The panels can move rather abruptly and without warning in response to such forces, enhancing the likelihood of injury or property damage. According to conventional panel design, resistance to sliding has been dependent upon friction between the flat floor surface and the bottom panel seal. This magnitude of resistance to sliding has proven insufficient in some cases.

Thus, there exists a need to substantially reduce the possibility of sliding of the panels. There also exists a need to impart significant additional strength to the ability of the top of the panels to resist large lateral loads.

It is therefore an object of the invention to improve operable wall systems;

It is another object of the invention to provide a method and apparatus for improving the resistance of operable wall systems to lateral loads;

It is another object of the invention to provide an operable wall system reinforced against lateral loads at the point where the operable wall panel interfaces with its overlying suspension system;

It is another object of the invention to provide an operable wall system which eliminates or reduces sliding of the bottoms of the operable panels in response to lateral loads; and

It is yet another object of the invention to provide operable wall apparatus with improved resistance to lateral loads which is convenient to use and relatively cost-effective to manufacture.

According to one aspect of the invention, the lateral load capacity of the top of an operable wall panel is greatly increased by means of retractable top load transfer means, preferably biased in the "up" or extended position, and mechanically latched "down" when not in use so as to lie flush with the top edge of the wall panel. Such top load transfer means, when extended, interfit with the structural elements of the guide track so as to transfer lateral loads directly from the top of the operable wall panel to the guide track. The top load transfer means thus act independent of the normal cylindrical-shaped trolley bolts, relieving the trolley bolts of loads other than vertical.

According to another aspect of the invention, sliding of the bottom of operable wall panels is prevented by a floor engagement means, which transfers the lateral load at the bottom of a panel directly to the floor. Such a floor engagement means greatly increases the ability of the bottom of an operable wall panel to resist lateral sliding motion. In one embodiment, the floor engagement means includes a lower floor engagement member carrying an acoustic gasket, which may be lowered to engage a floor insert member fixed to the floor.

The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings.

FIG. 1 is an elevation of an operable wall panel employing lateral load transfer apparatus according to the preferred embodiment;

FIG. 2 is a cross-sectional drawing illustrating the interface between a load transfer bolt and an operable wall guide track according to the preferred embodiment;

FIG. 3 partially cut-away side view of apparatus shown in FIG. 2;

FIG. 4 is a cross-sectional view of load transfer apparatus employed at the bottom of an operable wall panel according to the preferred embodiment; and

FIG. 5 is an enlarged view of a portion of FIG. 4.

The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide easily operated and conveniently manufactured apparatus for improving the resistance of operable walls to lateral loads.

An operable wall 11 according to the preferred embodiment is illustrated in FIG. 1. The wall 11 generally includes a wall panel 12 suspended from the ceiling by a guide track mechanism employing trolleys 21, 23 connected to the panel 12 by dependent bolts 22, 24. Apparatus according to the preferred embodiment for stabilizing the wall panel 12 against lateral loads includes upper top load transfer bolts 13, 15 and a lower floor engagement member 85. The lower floor engagement member is connected to first and second floor engagement pistons 42, 45. The load transfer bolts 13, 15 and lower floor engagement member 85 are actuated by an intervening mechanism including upper and lower actuation cables 31, 48 and a lever 35.

With reference to FIGS. 1-3, the top load transfer bolts 13, 15 are slidably mounted within respective rectangular housings 17, 19. Each respective bolt 13, 15 is connected to a respective actuating cable 27, 29, which is, in turn, connected to the opposite ends of a cross-member 25. The cross-member 25 is connected at its center to the upper actuation cable 31. As may be seen in FIGS. 2 and 3, each actuation cable 27, 29 is connected to its respective load transfer bolt 15, 13 by means of a pin 66 inserted through an eyelet 68, which is connected to, or formed as part of, the actuation cable, e.g., 27. The eyelet 68 resides within an eyelet receptacle 65 in the load transfer bolt 15.

The housing 19 for the load transfer bolt 15 includes a floor 64 through which the actuating cable 27 passes. First and second springs 71, 73 are connected to the floor 64 and pass into respective cylindrical apertures, e.g. 75, in the generally solid bolt 15. This bolt 15 is preferably steel and is generally rectangular in width and cross-section. The width "W" may be, for example, three inches. The width "W" is thus considerably wider than that of the diameter of the cylindrical dependent bolts, e.g. 22, 24 and, therefore, can support and transfer considerable lateral loads.

As further shown in FIGS. 2 and 3, the upper end of the wall panel 12 includes a generally rectangular channel 57 having a top opening 58 therein through which the load transfer bolt 15 extends and retracts, as further discussed below. The rectangular channel 57 constitutes part of the panel's perimeter structural frame to which a steel panel face is welded. The structural frame also includes similar vertical channel members welded to the steel panel face. Housing 19 (FIG. 3) is attached to the top of the panel structure by means of a plate 59, attached, e.g., by welding to channel 57.

FIGS. 4 and 5 more particularly illustrate the floor engagement apparatus according to the preferred embodiment. This apparatus includes the piston 42, which is mounted to extend and retract in a cavity 88 in the lower end of the wall panel 12. The piston 42 is attached to the lower floor engagement member 85, which has a serrated lower edge 84. The retracted position of edge 84 is shown in phantom in FIG. 4.

The serrated edge 84 engages a floor insert 87. This insert 87 is preferably fabricated of aluminum, brass, bronze, or steel, and has an upper face serrated to mate with the serrated edge 84 of the lower floor engagement member 85. The floor insert 87 may be retained by a concrete anchor 91 (FIG. 4) if the insert 87 is cast into a floor or retained by concrete or grout.

As shown in FIG. 5, the serrated edge 84 is preferably provided by an acoustic gasket member 93. The gasket member 93 is preferably extruded from flexible material such as polyvinylchloride or neoprene, although it could be a metal such as spring steel. Fingers or fins, 94 on either side of the acoustic gasket member 93 provide compliant gaskets which conform to minor surface irregularities and thus provide an effective acoustic seal. The acoustic member 93 may be extruded with a suitable flanged slot 98 to engage and interlock with a mating surface on the bottom edge of lower floor engagement member 85.

As shown in FIG. 1, the actuation lever 35 is connected by means of the lower actuation cable 48 to a connection post 49 attached to the floor engagement member 85. The floor engagement pistons 45, 47 are biased downward by suitable biasing means, such as springs respectively mounted in the housings 41, 43. Thus, pistons 45, 47 normally force the floor engagement member 85 into contact with the continuous floor insert 87. The upper actuation cable 31 is wrapped around a pulley 37 which is fixed within the panel 12, and then connected to the lever 35. Lever 35 is pivotally mounted at a pivot point 39 on the panel 12. Thus, when the lever 35 is moved clockwise in FIG. 1, the cross-member 25 is pulled downward, defeating the spring bias and retracting the top load extension bolts 13, 15. At the same time, the lower actuation cable 48 is pulled upward, retracting the floor engagement member 85 against the spring bias within cylinders 41, 43, thereby disengaging the acoustic gasket 93.

Thus, the preferred embodiment advantageously provides simultaneous disengagement of the load transfer mechanisms. It will be apparent to those skilled in the art that the top and bottom retractable elements 13, 15, 85 can be retracted independently by means of separate levers, cranks, and so forth, should such operation appear desirable. Metal rods or links could be used in place of either cable 31, 48.

It may be noted that the top load transfer bolts 13, 15 must be retracted entirely out of the guide track slot 101 (FIG. 2) in many applications in order to permit movement of the panel 12 when it does not remain centered under its guide track, for example, when traversing curves or angular track intersections, or when the panel is rotating in a horizontal plane.

The design of the surface of track 87 and the mating surface 93 on the bottom of the retractable floor engagement member 85 could take a number of shapes which accomplish load transfer, while not presenting a hazard or impediment to foot traffic or an obstacle to simple cleaning.

Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.