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United States Patent Application	20090126311
Kind Code	A1
Stanley; Julius	May 21, 2009

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Claims

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1. A method for securing an opening in a concrete slab, comprising:forming a plurality of through-holes around the perimeter of the opening while fabricating the concrete slab; andattaching a sheet material over the opening by passing a respective bolt through each of the through-holes to extend from beneath the concrete slab and securing each respective boll with a nut; wherein, each respective bolt has a bent portion that overlaps a portion the sheet material and each respective nut attaches to each respective bolt underneath the concrete slab.

2. The method of claim 1, wherein each respective bolt and nut attach via threads.

3. The method of claim 1, wherein each respective nut is configured to be tightenable using a hammer.

4. The method of claim 1 wherein each respective bolt is rotatable within its through hole so as to allow the bolt to move in order to no longer overlap the sheet material.

5. The method of claim 1, wherein the step of forming further includes:placing a support structure adjacent a location of the opening before forming the concrete slab:supporting a dowel in a generally upright position within the support structure; andremoving the dowel from the concrete slab.

6. The method of claim 5, wherein the dowel extends through the entire thickness of the concrete slab.

7. An apparatus for forming a through hole in a concrete slab, comprising:a plurality of support legs, the support legs tapering in distance from one another such that the support legs are further apart at the bottom than the top;a plurality of rings supported by the support legs, the rings aligned in a vertical direction and each of the support legs having an upper end terminating at an uppermost of the plurality of rings;the plurality of rings configured to accept and hold a dowel substantially upright; andeach of the support legs having a lower end configured to attach to a form used to fabricate the concrete slab and being sized to locate the uppermost ring approximately one inch below the top of the slab.

8. The apparatus of claim 7, comprising three support legs.

9. The apparatus of claim 7, comprising two rings.

10. The apparatus of claim 7, wherein a lowermost of the plurality of rings is located approximately one inch above the form.

11. The apparatus of claim 7 constructed of wire.

12. The apparatus of claim 7 wherein each respective lower end of the support legs is coated.

13. The apparatus of claim 7, wherein each respective lower end of the support legs accepts a tack to secure the apparatus to the form.

14. An apparatus to hold a sheet material above an opening in a concrete slab; comprising:a boll having a bent portion configured to overlap an edge of the sheet material and a shaft portion extending through a through hole in the concrete slab adjacent the opening;the bolt having a threaded portion on a lower end of the shaft portion such that the threaded portion extends below a lower surface of the concrete slab; anda nut configured to attach to the threaded portion such that the nut is located below the concrete slab.

15. The apparatus of claim 14, wherein the nut includes a flange configured to hold a portion of a whaler below the opening of the concrete slab.

16. The apparatus of claim 14 wherein the nut includes an outer surface configured to be struck with a hammer to adjust a tightness of the nut relative to the bolt.

17. The apparatus of claim 14, wherein at least one of the bolt and nut includes a high-visibility surface color.

18. The apparatus of claim 14, wherein the lower end of the bolt extends at least four inches below the lower surface of the concrete slab.

19. The apparatus of claim 14, wherein the bent portion provides at least one inch of a striking surface, for a substantially horizontal strike, above the sheet material.

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Description

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FIELD OF THE INVENTION

[0001]This invention relates generally to construction and more particularly, to safety systems and methods to employ during construction.

BACKGROUND

[0002]During construction of large buildings, and even smaller buildings, there are often many concrete structures, such as floors, that have openings in them. These openings may be temporary during the actual construction of the building or they may be permanent features of the building. The purposes of the openings can vary widely. Some permit passageway of materials and equipment during the construction process or some may provide openings for conduit and duct work that will become part of the building upon completion.

[0003]These openings present a safety hazard to the workers on the construction site and many ad-hoc methods of addressing the safety concerns have been developed. For example, one common method that is deployed as needed is simply power-nailing a piece of plywood over the hole to prevent a worker from falling in or through the hole. Because damaging the concrete surface is discouraged during construction, the nails used are often relatively short and, thus, do not provide great security and fastening strength. Furthermore, removing the sheet of plywood to temporarily provide access to the hole is difficult and the nails can not be re-used.

[0004]Often many of the openings are ultimately re-filled as part of the construction process. Thus, some type of re-enforcing structure is utilized underneath an opening to support the concrete that is poured into the opening and allowed to set and cure. Thus, this requires the construction of other structures that can also potentially damage the concrete surface or, at the very least, be difficult to accomplish by one person.

[0005]There remains a need in the industry to address these and other needs as described below with respect to various embodiments of the present invention.

SUMMARY OF THE INVENTION

[0006]Embodiments of the present invention relate to a safety device and method for construction sites that provide secure and easy fastening of a sheet material over an opening in a concrete slab. By covering the opening, injuries and other risks posed by openings can be avoided. Holes are formed through the concrete around the opening and then a two part fastener is used to securely hold the sheet material (e.g., plywood). This approach also allows easy configuration of a method to re-fill the openings with concrete if desired.

[0007]It is understood that other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only various embodiments of the invention by way of illustration. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 depicts a support structure that is useful in accordance with the principles of the present invention for forming holes in concrete structures that allow safety devices and techniques to be utilized therein.

[0009]FIG. 2 illustrates the structure of FIG. 1 in operational use.

[0010]FIG. 3 depicts an opening in a concrete slab 202 that has adjacent through holes 302, 304 in accordance with the principles of the present invention.

[0011]FIG. 4 shows a top view of an opening 202 having one example pattern of through-holes in accordance with the principles of the present invention.

[0012]FIG. 5 depicts the top view of FIG. 4 but with a sheet of plywood or other material secured over the opening in accordance with the principles of the present invention.

[0013]FIGS. 6 and 7 depict a side view of the two part fastener constructed in accordance with the principles of the present invention.

[0014]FIGS. 8-10 depict a detailed view of the fastener of FIGS. 6 and 7.

[0015]FIGS. 11 and 12 depict embodiments of the present invention in use with a whaler 1102.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016]The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring the concepts of the invention.

[0017]FIG. 1 depicts a support structure that is useful, in accordance with the principles of the present invention for forming holes in concrete structures that allow safety devices and techniques to be utilized therein. The support structure 100 is depicted as a tripod-like device having three legs 102, 104, 106. However, one of ordinary skill will recognize that a different number of legs could be used without departing from the scope of the present invention. Typical wire used for such a structure 100 can include, for example, the wire used for #9 and #10 wire chairs.

[0018]The legs 102, 104, 106 support two rings 108, 110. These rings are used to hold a dowel 112 in a generally upright position. Thus, the inner diameter of the rings 108. 110 are sized to snugly match the outside diameter of the dowel 112. One exemplary dowel 112 could be constructed from a length of PVC pipe that is readily available on most job sites. For example, using 3/4 inch PVC pipe will result in a hole that accommodates a fastener device described later. The support structure 100 rests securely on a form 114. Some or all of the legs 102, 104, 106 may include an opening, or loop that will hold a nail 116 or other fastener for securing the structure 100 in place on the form 114.

[0019]As for material, the support structure is beneficially constructed from light weight steel. However, composite materials as well as plastics may be used as well. In operation, the structure 100 will be placed in a poured concrete form and thus will be strong enough to withstand the pressures and forces of such an environment. The inside of the rings 108, 110 are preferably treated with some type of release agent so that the dowel 112 is easily removable from the structure 100. Although a dowel is usually round in shape, other shaped (e.g., ellipses, square, etc.) may be used but some of the benefits provided by a round shape will not be realized.

[0020]FIG. 2 illustrates the structure of FIG. 1 in operational use. Only one structure is shown in FIG. 2; however, multiple such structures would typically be used as described further herein. The structure 100 is placed within a concrete structure 204 (prior to pouring. This structure 204 includes an opening 202 that creates a safety risk for the workers during construction. FIG. 2 depicts how a sheet of plywood or other material 200 can be placed over the opening 202. One of ordinary skill will recognize that different dimensions can be used for the structure 100 based on the thickness of the slab of concrete 204. Also, different coatings and materials can be used for the structure 100. For example, if a steel tripod structure is used, then the bottom inch or so of the legs can be dipped in plastic or other material.

[0021]In general, however, there are certain dimensions that can be utilized to provide particular benefits. For example, the distance "C" between the structure 100 and the opening 202 can be at least 4 inches. This will provide sufficient strength for the resulting hole. Also, the distance "A" can preferably be at least one inch form the top of the slap 204 to avoid any discoloration or other blemish to the surface of the slab 204. For similar reasons, the distance "B" can preferably be 1 inch as well. These distances will also provide a structure that can securely hold the dowel 112 in the desired upright position.

[0022]Once the concrete slab 204 is poured and cured, the dowels 112 is removed to create a through-hole 302 adjacent the opening 202. FIG. 3 depicts an opening in a concrete slab 202 that has adjacent through holes 302. 304 in accordance with the principles of the present invention.

[0023]FIG. 4 shows a top view of an opening 202 having one example pattern of through-holes in accordance with the principles of the present invention. The figure shows 6 holes 302, 304, 402 arranged around the perimeter of the opening 202. Using fewer holes or using more holes, is contemplated within the scope of the present invention. For example, if a particular spacing (e.g. every 12 inches) between holes is desired, then sufficient holes to address any sized opening can be used.

[0024]FIG. 5 depicts the top view of FIG. 4 but with a sheet of plywood or other material secured over the opening in accordance with the principles of the present invention. In this example, only four holes were used so four fasteners 502, 4504, 506, 508 are used. These fasteners may, for example, be painted bright orange (or red, or fluorescent, etc.) to be visibly distinct. In operation, they securely hold the plywood 200 over the opening but will allow its removal relatively easily.

[0025]FIGS. 6 and 7 depict a side view of the two part fastener constructed in accordance with the principles of the present invention. The fastener has a bent bolt 602 with a top structure that fits over the edge of the plywood 200. This bolt 602 extends through the hole in the concrete slab and is threaded to match a nut 604. As shown in FIG. 7, the nut 604 is sized sufficiently to hold a bottom sheet of plywood 702 in place as well. The bolt and nut can be painted or otherwise adorned with high-visibility markings to help further reduce risks of accidents on the work site.

[0026]FIGS. 8-10 depict a detailed view of the fastener of FIGS. 6 and 7. The nut 604 has a threaded opening 802 that mates with the threads 1002 of the bent bolt 602. The nut 604 has a number of purposes and can be sized in a variety of dimensions without departing from the scope of the present invention. Similarly, the bent bolt 602 can be used in varying thicknesses of concrete and thus must have a shaft 1004 that is long enough to extend through the slab for which it is being used. On a work site, workers appreciate tools that are easy to use and can be manipulated while wearing work gloves and using the other tools on hand without requiring specialized equipment. Thus, the bolt 602 and nut 604 are sized to allow hammering and banging with typical hammers on a job site.

[0027]For example, the height "A" of the nut 604 is preferably about 2 inches with the lip "B" being about 1/4 inch thick. The diameter "D" is approximately 41/2 inches with an opening "E" roughly 1/2 inch in diameter. The resulting flange "C" is around 2 inches.

[0028]As explained herein, the fastener structure (602, 604) may be used to hold an upper and lower sheet of plywood as well as a whaler (See FIG. 11). If the plywood is assumed to be 3/4 inches thick and the whaler is a standard 2.times.4, then the following dimensions provide for a beneficial bolt 602 and nut 604. One of ordinary skill will recognize that these dimensions are merely an example and that the sizes may be modified to accommodate different sized support material. The bolt 602 can have a length "F" of the bent portion that is about 2 inches and if the shaft 1004 is about 1/2 inch thick, then the holding portion "G" is about 11/2 inches. Thus, a worker would cut a piece of plywood to size to fit an opening yet extend towards a hole such that the bolt 602 would overlap and hold the plywood. The thickness "J" can be around 1 inch as such a thickness will allow it to be easily struck by a hammer.

[0029]The inside bolt length "I" depends on the thickness of the slab. In practice, for example, the length should accommodate two pieces of 3/4 in plywood, a 2.times.4 (roughly 4 inches wide) and the 2 inches of the nut 604. Thus, the inside length "I" is preferably the thickness of the slab plus 71/2 inches. For example, then, a ten inch slab would require a bolt 602 having an inside length "I" of 171/2 inches. The minimum thread length "H" will have to accommodate the most minimal use which would be a single sheet of plywood. Thus, the minimum thread length "H" is the inside length "I" minus the slab thickness and 3/4 inches. In the example bolt above for a 10'' slab, the inside length "I" was 171/2 inches and, thus, the minimum thread length "H" is 63/4 inches. Again, one of ordinary skill will recognize that these lengths are exemplary only and other variations may be used without departing from the scope of the present invention.

[0030]FIGS. 11 and 12 depict embodiments of the present invention in use with a whaler 1102. Such a whaler 1102 would be used across the bottom of an opening to hold plywood 702 in place when re-filling the opening with concrete. As shown, the flange of the nut 604 is sized to accommodate the 2.times.4 1102. Also visible in FIG. 11 is the part 1104 of the nut 604 that is orthogonal to the plane of the drawing page. This part 1104 can be repeated around the nut 604 so that a user has multiple striking surfaces by which to tighten the nut 604.

[0031]In practice, a piece of plywood is cut to fit an opening and multiple bolts 602 are inserted in the holes along the perimeter of the opening. From below, the nuts 604 are threaded on the bolts 602 and tightened using a hammer or similar device. As mentioned earlier, an additional sheet of plywood and whaler can be used beneath the opening as well. From above, a worker can simply strike the bolt 602 to turn it 90 degrees so that it no longer overlaps the plywood. This allows the plywood to me removed (as needed) and then reattached by simply reversing the process to return the bolts 602 to a position where they overlap the plywood. From below, the nuts 604 can be removed without any coordination from above in order to add or remove a sheet of plywood and whaler. Because of the intended environment, the bolts and nuts are constructed from high strength materials such as steel or similar material. In addition, hardened steel or even more durable materials may be utilized if desired. Further-more, the openings shown in the attached figures have been roughly rectangular in shape. However, other shapes and even irregular shapes can be accommodated without departing from the scope of the present invention.

[0032]The previous description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications lo these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the full scope consistent with each claim's language, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. .sctn.112, sixth paragraph, unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the element is recited using the phrase "step for."

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