Patent Application
20070173562
Not Applicable.
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Not Applicable.
The present invention is directed generally to an embed plate, and more specifically to a thin embed plate having cup portions along a perimeter thereof.
Structural concrete portions, such as concrete slabs, footings, raft foundations, beams, walls, floors, columns, precast/prestressed concrete components, and the like, are generally able to withstand a good deal of compressive force. These same concrete structures, however, generally react poorly to shear and tensile forces within or applied to the structure. These forces cause cracking or breakage within the concrete portion. Such cracking or breakage may occur internally to the concrete portion and therefore may go unnoticed until the situation becomes serious and the structural integrity of the concrete component or structural system has been compromised.
Concrete embed plates are commonly used to provide strong support for attachment of fixtures or other structures to a structural concrete portion, and to allow such structures to better support applied loads and withstand tensile and shear forces external to the structure, such as from dead loads, wind, seismic forces, live loads, and the like. Such plates may also be used to attach two or more concrete portions to one another. Traditional embed plates include a plate portion and a plurality of studs that extend perpendicularly therefrom. While these embed plates provide some protection against shear forces, under sufficient load shear forces nevertheless result in failure of the concrete at the area of the four studs. Further, traditional embed plates must be relatively thick in order to have sufficient strength to be used for their intended purpose. This leads to a corresponding increase in weight of the concrete structure in which the embed plate is embedded, which may be of concern in construction projects wherein the weight of the finished structure is extremely important (such as with respect to bridges and the like).
The present invention provides, among other things, an embed plate with enhanced shear protection with respect to traditional embed plates, and is at the same time lighter and stronger than a traditional embed plate.
The present invention is directed to a concrete embed plate having a body portion and at least one cup portion projecting from the body portion and extending outward and downward therefrom. It is preferred that the body portion and at least one cup portion of the present embed plate are constructed from a single, unitary piece of material.
In an alternative embodiment, the present embed plate preferably includes at least one side portion, which is also preferably constructed from the same unitary piece of material as the body portion. The side portion(s) of the present device preferably include at least one tab, which may be part of the same, unitary material as the side portion or may be constructed from a separate piece of material and attached to the side portion by any suitable mechanism such as, for example, welding. The tab portion further preferably includes an opening adapted to receive a portion of a concrete reinforcing structure such as rebar.
In another embodiment of the present invention, the side portion(s) of the present embed plate preferably include at least one stiffening dart to lend strength thereto.
In still another embodiment of the present invention, the side portion(s) of the present embed plate further include a cutout portion adapted to receive at least a portion of a concrete reinforcing structure.
In yet another embodiment of the present invention, the side portion(s) of the present embed plate further include at least one leg portion extending therefrom along the same plane as the side portion. It is preferred that each leg portion include an opening therein adapted to receive at least a portion of a concrete reinforcing structure.
The various embodiments of the present invention are preferably constructed from steel, but any suitable material, such as other metal alloys, aluminum, titanium, synthetic polymers, carbon fiber, or combinations thereof, may also be used in the construction of the present embed plate.
Turning now to the drawings, wherein like numerals indicate like parts, the numeral 10 refers generally to an embed plate constructed in accordance with the teachings of, and exemplifying, the present invention. In a preferred embodiment, embed plate 10 includes a body portion 12, cup portions 14, and tabs 16, and is preferably constructed from steel, although any suitable material may be used.
Body 12 of embed plate 10 preferably includes first and second cup portions 14 extending downward therefrom. Cup portions 14 preferably extend from opposing edges of body 12, as shown in
Cup portions 14 of embed plate 10 are preferably constructed from the same, unitary piece of material from which body 12 is constructed. That is, it is preferred that cup portions 14 are not welded or otherwise attached to body 12 of embed plate 10. While in some embodiments of the present invention such welded or otherwise attached cup portions 14 may be utilized and may be sufficient for a given application of embed plate 10, preferred embodiments constructed from a single, unitary piece of material as described above provide greater strength to embed plate 10. Using a weld or other means of attachment to secure cup portions 14, as separate pieces, to body 12 creates points of weakness that in turn lead to a weaker embed plate 10. While this may be acceptable in certain circumstances, it is not preferred.
As shown in
Tabs 16 extend outward from side portions 24 as shown in the drawings, along a plane substantially parallel to the plane of body portion 12 of embed plate 10. Although two tabs 16 are shown in the drawings as being present on opposing sides of embed plate 10, it is contemplated that only one tab 16 may be present along a given side of embed plate 10, or that more than two tabs 16 may be present along a given side. Further, each side of embed plate 10 having tabs 16 need not have the same number of tabs 16. That is, a first side of embed plate 10 may have two tabs 16 present therealong, while a second side may have one tab 16 or more than two tabs 16 present therealong. In addition, tabs 16 may be provided substantially parallel to the plane of body portion 12, as shown in the drawings, or may be provided at an angle thereto, such as a 45 degree angle, for example. It is contemplated that any suitable angle may be used.
As also shown in the figures, tabs 16 may include holes 18 extending through the width thereof. Holes 18 are preferably adapted to receive riveted studs or other structural reinforcing portions therethrough such that embed plate 10 can be utilized along with existing concrete reinforcing structures known in the art. Inclusion of holes 18 provides a mechanism for engagement of riveted studs with embed plate 10 without the need to attach Nelson or welded studs to embed plate 10 by welding or other means. It is contemplated, however, that embed plate 10 may be provided without holes 18.
In use, the top surface of body 12 of embed plate 10 is preferably flush with an outer surface of the concrete structure in which embed plate 10 is embedded. Opening 20 in body 12 is provided for attachment of embed plate 10 to concrete forms during placement and before pouring the concrete in the form and around the plate. The hole is also used to allow air to escape under the plate when concrete moves under the plate. Although a single opening 20 is shown in the figures, it is contemplated that more than one opening 20 may be provided with embed plate 10. In addition to attaching a concrete form to embed plate 10 by means of opening 20, it is further contemplated that a screw or other fastener may be welded to the upper surface of body 12 of embed plate 10 so that attachment to threaded rods may be accomplished at angles other than those allowed by opening 20.
The embodiment 300 of the present invention shown in
Also shown in
As noted above, it is preferred that the various embodiments of the present invention are constructed from steel. Because of the novel configuration of the present device, as described above, the thickness of steel required to produce the device is less than that of the typical embed plate known in the art. A traditional embed plate is generally ⅜ inches to ½ inches thick, whereas the present device is preferably only ⅛ inch thick at its thinnest thickness. The present device can impart greater strength to the concrete, while remaining thin, because the cup portions of the present device add greater strength to the device, as do the leg portions in embodiments of the present device that include leg portions. These features increase the surface area of the embed plate in contact with the surrounding cement, giving greater protection against shear and tensile forces. For example, in edge pullout shear capacity tests performed using a ⅛ inch embed plate without the novel cup portions of the present device, load failure occurred at 13,659 pounds. When the same test was conducted using a ⅛ inch embed plate that included the novel cup portions of the present invention, load failure occurred at 21,195 pounds. Using rebar in association with the ⅛ inch embed plate of the present invention resulted in load failure occurring only at 23,550 pounds. Thus, the present design allows for greater strength while using less material to construct the embed plate. This results in lighter plates and, correspondingly, lighter concrete structures in which the plates are embedded. Also, the cost of manufacture of the present embed plate is less than that of traditional embed plates because less steel or other material is used.
In addition to steel, any other suitable material may be used. For example, aluminum or aluminum alloys may be used, as may various other metals. It is further contemplated that for some applications various synthetic polymers may be used. Likewise, carbon fiber may be used to construct an embed plate in accordance with the teachings of the present invention, providing for an extremely light-weight, yet strong plate.
In addition to changes in material composition, alterations may be made to the basic structure of the present device without departing from the scope of the invention. As described above, for example, the number and size of the various cup portions may be altered. Likewise, the number and size of the various leg portions or tabs may be altered as needed for a given application. In addition, ridges may be provided along the various surfaces of the embed plate that are shown in the drawings as smooth surfaces. The addition of such ridges further increases the surface area of the device in contact with the surrounding concrete and further protects against shear forces. It will be readily apparent to those of skill in the art, upon reading this disclosure, that many other modifications may be made to the present invention.
Although numerous advantages and characteristics of the present invention have been described herein, together with details concerning the structure and function of the invention, the foregoing description is exemplary only. Accordingly, changes may be made in detail, particularly in matters of shape, size, arrangement of features, and materials of the present invention while still remaining within the broad spirit and scope of the invention. It is intended that the scope of the invention be limited only by the claims that follow.
