Patent Publication Number: US-2002000070-A1

Title: Wall plate for attaching beams to masonry walls

Description:
[0001] This application is a continuation-in-part of application Ser. No. 09/573,586,filed May 18, 2000, now U.S. Pat. No. 
    
    
     
       BACKGROUND OF THE INVENTION  
       [0002] This invention relates to a novel wall plate embedded in a masonry wall for the purpose of attaching that wall to a structural beam. In particular, it relates to embedding a novel wall plate in a precast concrete wall and also in a horizontal ledge of a concrete block masonry wall and attaching a steel beam to the wall plate.  
       [0003] In the construction of commercial buildings, it is common practice to pour concrete between vertical wood forms to make the walls. Steel plates having anchors extending inward are nailed to the inside of the forms and, when the concrete has been poured and has hardened, become imbedded in the wall. Steel beams are held against these plates, either by scaffolding or by a crane, and the beams are welded to the plates.  
       [0004] This method of attaching the beams to the walls is time-consuming as it can be difficult for a crane operator to hold the beam in the required position until the welding is completed. It can also be dangerous for the welder if the scaffolding or crane slips or moves. The heat from field welding can expand the steel plate and crack the concrete and, when the building is finished, the welds are hidden by the interior structures of the building and can no longer be easily accessed for inspection. If moisture condenses on the welds, they can corrode and weaken.  
       SUMMARY OF THE INVENTION  
       [0005] We have discovered that steel beams can be attached to masonry walls easily and quickly by embedding a threaded wall plate in a masonry wall. The steel beam can then be attached to the wall by bolting it to the wall plate and no field welding is required.  
       [0006] The wall plate of this invention can be embedded in precast concrete panels, which can then transported to a building site and bolted to steel beams that are already in place. Also, the wall plate of this invention, embedded horizontally in concrete on a ledge or the top of a concrete block masonry wall, can be used to attach beams, joists, and joist girders to the wall. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0007]FIG. 1 is an isometric view showing a wall plate according to this invention embedded in a concrete wall and having a steel beam bolted to it.  
     [0008]FIG. 2 is a top view of the wall plate shown in FIG. 1.  
     [0009]FIG. 3 is a front view of the wall plate shown in FIG. 1.  
     [0010]FIG. 4 is a front view of a wall plate, similar to the wall plate shown in FIG. 1, but having only two bolt holes and a nut bar for each bolt hole.  
     [0011]FIG. 5 is an isometric view showing the wall plate of FIG. 4 embedded in a precast concrete panel, where the panel is attached to a structural beam.  
     [0012]FIG. 6 is a side view through a section of a masonry wall showing the wall plate of FIG. 4 embedded in the wall and a structural steel beam, joist, or joist girder attached to the wall plate. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0013] In FIGS. 2 and 3, a wall plate  1  according to this invention has a flat plate  2  with a mark  3  at its top center. Anchors  4  have been welded to flat plate  2 . Also welded to flat plate  2  are two parallel nut bars  5 , each having four spaced threaded holes  6  therethrough. The holes  6  on each nut bar  5  are equidistant from the center of flat plate  2 , as indicated by mark  3 . Adhesive sheets  7  cover the inside of threaded holes  6  to prevent concrete from entering and also covers the face of flat plate  2  to keep its surface free of concrete. Threaded holes  6  are aligned with slightly larger unthreaded bolt holes  8  in flat plate  2 . Bolt holes  8  need not be circular, but can be slotted or elongated to permit adjustments. In addition, there are a number of nail holes  9  through flat plate  2 .  
     [0014] Referring now also to FIG. 1, wall plate  1  is fixed to vertical concrete wall  10  by means of its anchors  4 , which became embedded in concrete wall  10  after the concrete had been poured and had hardened. Form  12  (partially shown) holds the concrete until it sets and is then removed. Two right-angle connectors  13  (only one shown) are loosely bolted to flat plate  2  by screwing bolts  14  through holes  8  and  6 . One connector  13  is on each side of horizontal steel beam  15 , which is fastened to connectors  13  by bolts  16 , which pass through slots (not shown) in steel beam  15 .  
     [0015] In FIG. 4, wall plate  17  has a flat plate  18  and two bolt holes  19  therethrough. Welded to the opposite side of flat plate  18  are with two anchors  20  (as in FIG. 2) and two nut bars  21  (similar to FIG. 2), so that two bolts can pass through bolt holes  19  and thread into nut bars  21 .  
     [0016]FIG. 5 shows a wall plate  17 , as in FIG. 4, embedded in precast concrete panel  22 . Precast concrete panel  22  has been transported and positioned vertically against already-assembled steel structural beam  23 . Wall plate  17  has been attached to beam  23  by means of clip angle  24  and bolts  25  and nuts (not shown) beneath beam  23 .  
     [0017] In FIG. 6, concrete block masonry wall  26  has been constructed with a horizontal ledge  27  formed by the top of bond beam  28 . Concrete  29  has been poured into the trough of bond beam  28  and a wall plate  17 , as in FIG. 4, was pressed into that wet concrete, which then set. Grout  30 , as necessary, was used to adjust the height of wall plate  17 . Structural steel beam, joist, or joist girder  31  has been bolted to wall plate  17  by bolts  32  (one shown) and nut bars  21 . A roof joist or other type of support structure could also be bolted to wall plate  17 .  
     [0018] While the flat plate and nut bars can be made of a variety of materials, such as metals, plastics, or other materials, it is preferably made of steel as that is the most appropriate material for this application. Various grades of steel can be used, including ASTM A-572-GR50, ASTM A-36, ASTM A-529, ASTM A-441, ASTM A572 GR42, ASTM A-572-GR60, ASTM A-572 GR65, ASTM A242, ASTM A588, ASTM A852, ASTM A514, ANSI 1015, ANSI 1020, ANSI 1025, ANSI 1045, ANSI 1045 FINELINE, ANSI 1060 FH “62,” ANSI 1060, and ASTM A-9. If desired, the flat plate and nut bars can be coated with a protective layer to prevent rust from forming. Examples of such protective coatings include cold-plated (painted-on) galvanized, hot dipped galvanized (molten zinc), mechanical galvanized, electro zinc plated, fluoropolymer, epoxy powder, zinc silicate, electroplated, and “Cadmium” plated. The flat plate can have any suitable shape or size, but is preferably rectangular and is about 10 to about 17 inches wide, about 6 to about 37 inches long, and about 0.375 to about 1.5 inches thick.  
     [0019] At least two nail holes are provided in the flat plate if the wall plate is to be nailed to a form. However, if the wall plate is to be embedded in a horizontal position, by, for example, pressing it into the top surface of poured concrete, nail holes are not needed. Also, nail holes are not needed if the wall plate is attached to the inside of the form by adhesive, tape, being made magnetic, by using bolts that pass through the form into the bolt holes, or other means.  
     [0020] The anchors are preferably fixed to the flat plate by welding, but could also be fixed by other means, or they could be formed by bending a partially cut out portion of the flat plate at a right angle. The anchors can have any appropriate size and shape, selected to prevent them from pulling out of the masonry wall or cracking or damaging wall  10 . They can be headed or bent reinforcing rods or bent bars, as desired. Preferably, they are headed shear connectors about  3  to about 12 inches long and about 0.75 to about 1.5 inches in diameter. Any number of anchors can be used, depending upon the size of the beam to be supported and other conditions; preferably, about 2 to about 12 anchors are used.  
     [0021] It is preferable to use threaded nuts or nut bars to hold bolts to the wall plate, but it is also possible to use threaded holes in the flat plate. If nuts or nut bars are used, they are preferably welded to the flat plate, but could be attached to the flat plate by other means as well. Nuts or nut bars can also be welded inside holes or openings in the flat plate. The side of the flat plate that is against the form, however, should not have projections extending beyond the flat plate, so that the flat plate completely touches the form.  
     [0022] The number of bolts required depends upon the size of beam to be supported, but usually about 2 to about 20 bolts about 0.625 to about 1.5 inches in diameter are adequate. The bolts are preferably made of ASTM A-307, ASTM A325, ASTM A490 steel, but can also be made of other materials and can be galvanized, cadmium plated, powder coated, or clean metal.  
     [0023] The adhesive sheets that covers the bolt holes at each end can be made of a variety of materials, such as polyethylene, polypropylene, polycarbonate, paper, etc. The forms (see FIG. 1) can be made of wood, composite, or other material that can be nailed and can be vertical, horizontal, or sloped. For some masonry walls, such as precast panels, steel forms may be advantageous; the wall plate is then attached to the inside of the form by means other than nails. The form can be laid horizontally to help prevent movement of the wall plate along the form until the concrete sets. The structural beams are usually at 90° to the wall, but it can also be at another angle using connectors that are bent at the desired angle.  
     [0024] To use the wall plate on a poured concrete masonry wall, vertical forms are erected and the wall plates are attached to the inside of the forms at the positions required to attach them to the structural beams. Marks  3  can be used to position the top of the wall plates even with the top of the beams. Concrete is poured into the forms to a height that at least covers the anchors. After the concrete has hardened, the forms are removed, the nails cut off, and the adhesive sheet covering the bolt hole is removed, leaving the wall plate fixed flush with the vertical concrete wall. The connectors can be first bolted to the structural beam, but it is preferable to first bolt them loosely to the embedded wall plate. The structural beam is then moved into position using, for example, a crane, and it is bolted to the wall plate.  
     [0025] To make a precast concrete panel, one or more wall plates are attached by any suitable means to the inside of vertical or horizontal forms at the positions required to attach the resulting concrete panel to structural beams and concrete is poured into the forms. After the concrete has set, the precast concrete panel is transported to the building construction site and is positioned so that angle connectors can be bolted to the wall plates and to the structural beams. The structural beam can be self-supporting or the precast concrete panel can support it (a tilt-up panel), The precast concrete panel is usually positioned vertically, but can also be nearly vertical or sloping.  
     [0026] If the masonry wall is made of concrete blocks, then the concrete is poured into the top of at least some of the blocks and the wall plate is pressed into that concrete, as shown in FIG. 6.