1. Field of the Invention
The invention lies in the field of construction. More particularly, the present invention relates to an apparatus for holding cables, wires, pipes, rebar, or other infrastructure at a selected height from deck level during construction of concrete slabs.
2. Description of the Related Art
In the area of construction, various techniques exist for placing concrete slabs, floors, beams, and the like, under a tension to thereby strengthen the structure. The placement of a tension assembly in concrete is well known in connection with concrete slabs, such as are used for highways, bridges, houses, office buildings, apartment buildings, parking structures, slabs-on-ground, rock and soil anchors, and water tanks.
A popular tensioning technique, commonly called “post-tensioning”, as shown in
For maximum strength, it is desirable that the cables exit the sidewall 114 of the slab 106 equidistant from the top surface 108 and the bottom surface 110. To accomplish this, prior to pouring the concrete 106 each cable 102 is placed on one or more support structures 100 of varying height so that it is held off of the deck surface 116 that the concrete 106 is to be poured. This allows the cables 102 to be encapsulated within the concrete 106 once poured because concrete can easily flow under the cables 102 while supported on the structures 100. Optimally, as the cables 102 span the length of the floor 116, the point where the cables 102 attach to, or pass through the above mentioned building support members 112 will be at a greater height, with respect to the deck level, from where the cables are positioned to run the remaining length of the floor. The configuration is similar to that of a suspension bridge. Therefore, looking at
For maximum strength, multiple cables 102 are used in a single concrete slab 106. The number of cables 102 used may be dictated by building codes in a particular jurisdiction. When multiple cables 102 are placed along the floor 106 in close proximity to each other, each cable must be supported. Several prior art methods exist for supporting multiple cables, each requiring the use of multiple standoffs. One such method is to use a separate standoff under each cable. As previously mentioned, the cables must be supported at a multitude of heights. This method has the disadvantage of requiring an inordinate amount of standoffs to be used in a single floor area.
Another common practice in the construction industry, shown in
As can be seen in
A second standoff of this type is manufactured by Aztec Concrete Accessories, Inc. of Fontana, Calif. This standoff has a central receiving area and a plurality of legs that extend downwardly from the receiving area. The central receiving area has a generally concaved configuration that can receive only a single rebar. In use, these standoffs have had a tendency to be unstable and tip over. The use of an annular ring extending around the legs of the standoff requires that a wire must be threaded through the interior of the standoff in order to tie the rebar within the receiving area. Importantly, this method of using rebar and wire has the further disadvantage of using metallic materials that will ultimately be encapsulated in the concrete. Over time, moisture trapped inside the concrete slab will cause the metal to rust inside the slab. As a result, the structural integrity of the slab will be compromised. Accordingly, these standoffs have been generally ineffective for meeting the needs of the construction industry.
When constructing a building with multiple levels, slabs must be placed at each floor level. At all times there must be a supporting surface upon which to pour the concrete slab. While the first floor of a building may be supported by the earth below, subsequent floors must be supported by other means until the cement has cured. A typical method, shown in
Once each floor is formed, it is often necessary to penetrate the concrete slab 106. For instance, installation of doors and windows require that screws or bolts be inserted into the slab 106 both from the top surface 108 and from the surface below 110. If a drill or screw being driven into the concrete penetrates a post-tension cable 102, the cable 102 can snap. The breaking of a cable 102 under such a large amount of tension can cause severe damage to the structure and possible physical injury to the worker. At a minimum, the cable must be replaced. This process is extremely difficult and expensive. It is therefore desirable to have a method of identifying the location of the post-tension cables 102 after the concrete 106 has been poured.
Using the current method of installing post-tension cables described above, there is no simple way of determining the physical location of the cables once they are encapsulated in the concrete. Often times an x-ray machine must be used, which suffers from the disadvantage of being costly, time consuming, and dangerous to human health. Metal detectors, which are cheaper and safer than x-ray machines, can be used. However, metal detectors are not without their shortcomings. Due to the large amount of rebar and other metallic materials embedded in the slab, distinguishing post-tension cables from other metal items, if possible at all, is difficult and time consuming.
Therefore a need exists to overcome the problems with the prior art as discussed above.
According to an embodiment of the invention, an apparatus for supporting infrastructure while pouring concrete slabs is provided which overcomes the above-mentioned disadvantages of the prior art apparatus of this general type.
In one embodiment, the invention provides a standoff apparatus that enables one to secure and support, among other things, cables, wires, conduit, rebar, and in particular, post-tension cables, at predetermined distances from a deck level while a concrete slab is poured onto the deck and around the cables.
The apparatus and method can be used for easily locating, among other things, cables, wires, conduit, rebar, and in particular, post-tension cables, after a concrete slab has been poured around the cables. While an embodiment of the invention is to secure any type of infrastructure, such as cables, wires, or rebar, the remainder of the specification will refer only to post-tension cables commonly known and used by those of ordinary skill in the art of construction.
There is provided, in accordance with embodiments of the invention, a standoff apparatus having a lower section for providing support and an upper section for placement of post-tension cables. The lower section and upper section can vary in dimension so as to provide varying standoff distances with respect to the deck that they will be placed upon. The upper section is provided with one or more receptacle areas capable of holding a cable once placed in that area. The lower section can have two or more legs to provide stability to the apparatus.
In accordance with an additional feature of the invention, the standoff apparatus includes an upper section having a plurality of grasping arm-type structures capable of holding a post-tension cable, inserted between each set of grasping arms. In an embodiment, the grasping arms are provided in pairs of two opposable arms, which have centers that are curved outward from each other, and have a bottom portion and top portion that are arranged in a configuration similar to a set of parenthesis. Only the bottom of each opposable arm is attached to the apparatus. The upper portions of the arms are disposed so that the gap between them is slightly smaller than the diameter of the cable that they are designed to hold. Preferably, the arms will be made of a material that allows them to bend slightly and, therefore, allows the cable to slip securely between the arms.
In accordance with yet another feature of the invention, the bottom of the lower section, which makes contact with the deck, is provided with raised characters. This feature will be useful in that at the time the concrete is poured, the raised letters located on the bottom of the lower section of the apparatus will ensure that no concrete will flow between the letters and the wooden deck. Once the slab is poured and hardened, the wooden deck will be removed from below the slab. One looking at the bottom surface of the slab from below will easily see the characters on the feet of the apparatus. The specific characters can be chosen to communicate the presence of a material other than concrete in that area. For instance, the letters “PTC” may be used to indicate the presence of post-tension cables. This area can therefore be avoided when drilling into the slab, so as not to damage the cables. In one embodiment of the invention, the cable being supported will be held in the center of the apparatus, and the apparatus will have feet, which are located on both sides of the cable. If the letters PTC appear on each foot, with the additional feature of having raised arrows on the bottom of each foot pointing in the direction of the opposing foot, it will be clear that cables are located between the two feet.
In accordance with another feature of the invention, the bottom of the lower section, which makes contact with the deck, is provided with recessed characters. The specific characters can be chosen to communicate the presence of a material other than concrete in that area. For instance, the letters “PTC” may be used to indicate the presence of post-tension cables. This area can therefore be avoided when drilling into the slab, so as not to damage the cables.
In accordance with yet another feature of the invention, the apparatus can be manufactured so that a portion of the apparatus will extend beyond an upper surface of the concrete slab once poured. This extension will enable one to locate the cable placement from the surface above, even after the slab has been poured. In one embodiment, this extension will be bristle-like extensions that can be seen and easily broken off to be flush with the upper surface of the slab once identification is no longer necessary. Other types of extensions can also be used.
In accordance with another feature of the invention, the lower section of the inventive standoff can have one or more continuous flanges, or “feet” of sufficient dimension in the horizontal direction to provide stability to the standoff apparatus in the vertical direction, with reference to the deck, or floor surface, in which the standoff will be placed.
In accordance with another feature of the invention, the lower section and the upper section can be separable pieces. The pieces can be made in various heights and combined with one another to achieve any of a variety of specific desired heights.
In accordance with another feature of the invention, the upper section can be separable from the lower section and two or more upper sections can be combined and attached to a single lower section to provide additional cable attachment locations.
In accordance with yet another feature of the invention, the upper section can be separable from the lower section and can be removably attached to a side of the lower section to provide holding support for infrastructure, such as cables.
In accordance with another feature of the invention, the apparatus is manufactured from a synthetic material that will avoid rusting or decomposing.
Although the invention is illustrated and described herein as embodied in an apparatus for supporting infrastructure while pouring concrete slabs, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. It is important to note that the present invention is not limited to slabs made from concrete and can be used in slabs made of many different materials. Additionally, the slabs described herein include slabs used in building construction, bridges, roads, and many other similar purposes.
The construction of the invention, however, together with additional features and advantages thereof will be best understood from the following description of the specific embodiment when read in connection with the accompanying drawings.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention, in which:
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention.
The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language).
Referring now to the figures of the drawing in detail, and in particular to
Standoff 400 has two sets of opposing legs 406 & 408 that extend downwardly from the main body 425 of the lower section 404. Quantities of legs other than four can also be used without departing from the true scope and spirit of the present invention.
Each of the legs 406 has a foot 410 that extends outwardly horizontally therefrom. Each of the legs 408 has a foot 412 that extends outwardly horizontally therefrom. As can be seen in
Referring now to
Once each slab 106 is formed, it is often necessary to penetrate the concrete slab 106. For instance, installation of doors and windows require that screws or bolts be inserted into the slab 106 both from the top surface 108 and from the surface below 110. If a drill or screw being driven into the concrete 106 penetrates a post-tension cable 102, the cable 102 can snap. The breaking of a cable 102 under such a large amount of tension can cause severe damage to the structure and possible physical injury to the worker.
Referring once again to
The inventive feature of providing characters and symbols on the bottom surfaces of the feet is useful in that at the time the concrete is poured, the raised areas contact the wooden deck surface 116 and prevent concrete from flowing between the letters and the wooden deck 116. Once the slab 106 is poured and hardened, the wooden deck 116 will be removed from below the slab 106. One looking at the bottom surface of the slab 106 from below will easily see the characters 422 on the feet 410, 412 of the standoff 400. Thus, it will be clear that cables 102 or other infrastructure are located between the feet and that the area is to be avoided when drilling into the slab, so as not to damage the cables.
In another embodiment, the characters or symbols 422 on the feet 410, 412 of the standoff 400 are recessed areas. The recessed areas accomplish the same goal as does the raised characters described in the previous paragraph, which is to communicate the presence of infrastructure within the area of the standoff 400.
Referring to
Referring now to
As can be seen in
Upper section 402 is shown in
It can be seen that a plurality of arm-like structures 434, 436, 438, 440, and others, extend from the upper surface 444 of the upper section 402. The arm-like structures 434, 436, 438, and 440 are provided for holding cables, rebar, wires, conduit or any other similar infrastructure, which would need to be encapsulated in a concrete slab. The arm-like structures 434, 436, 438, and 440 are provided in pairs of two opposable arms that form receiving areas for holding the infrastructure 102. As shown in
Referring now to
The present invention can also be achieved with the embodiment shown in
Referring now to
The present invention, as just described, by providing lower sections 404 and upper sections 402 of varying heights that removably attach to one another, provides a multitude of standoff heights for supporting infrastructure on a surface so that concrete or other materials and substances can be poured around the standoff 400 and infrastructure. The present invention is able to securely hold several infrastructure items without the use of wires or other materials. The present invention is also able to communicate the location of the invention itself, as well as the location of infrastructure.
Although specific embodiments of the invention have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments, and it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the present invention.
This application claims priority from provisional application No. 60/503,702, filed Sep. 17, 2003, the entire disclosure being incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
60503702 | Sep 2003 | US |