Patent Application
20070235628
The present invention relates to wall form systems used in poured concrete structures and connecting hardware used in the systems, and more particularly, to a concrete form tie rod having ends thereof that are especially adapted for subsequent use as components in connecting hardware of a concrete wall form system.
Prefabricated wall forms are commonly used in forming concrete walls and other concrete structures. Such wall forms typically include prefabricated and reusable panel sections that are assembled to create the wall form arrangement for the concrete structure to be poured. Various pieces of hardware are used to interconnect abutting sections of the reusable panels.
Typically, each panel includes a facing surface that makes contact with the poured concrete, and a rear surface including a connecting flange. The flanges of the adjacent wall panels abut one another. Each flange has at least one hole that aligns with a hole of the abutting flange. Connecting hardware in the form of a pins or bolts are used to secure abutting flanges of adjacent panels. The pins are inserted through the aligned openings of the abutting flanges. Optionally, the pins may also pass through the ends of tie rods that are used to stabilize the spaced apart relationship of the wall forms. The tie rods are secured to the pins by wedges that are driven through slots formed in the shanks of the pins. As the wedges are driven in place, the abutting flanges of the adjacent panels are drawn together.
The pin and wedge combinations comprise a simple yet effective means for coupling the panel sections together. The pins and wedges can be removed from the panels during disassembly of the wall forms by forcing the wedges out from the slots and sliding the pins back out from their holes thereby releasing the adjacent panel units from one another. The tie rods remain embedded in the cured concrete.
There are a number of references that disclose various types of wall form systems used in concrete construction. There are also a number of references that disclose components of the wall form systems to include the specific hardware used in the systems.
Two references disclosing tie rods include the U.S. Pat. Nos. 4,239,173 and 4,433,826. Examples of references disclosing pins used in concrete wall form panels include the U.S. Pat. Nos. 5,802,795 and 6,905,106. One example of a reference disclosing a particular wedge design is the U.S. Pat. No. 5,904,875.
Wall forms for concrete construction typically require a large amount of hardware to connect the numerous panels together. Multiple pin and wedge combinations typically connect each pair of adjacent panels. Particularly for large concrete forms, the force of the concrete being poured as well as the continued pressure exerted on the forms by the concrete during curing, requires the form constructions to be quite robust, thus requiring the large amount of connecting hardware.
One recurring cost that is incurred each time reusable concrete forms are used is the cost of the tie rods and wedges. The tie rods are consumed in each project, and the wedges oftentimes cannot be reused because they are damaged during placement and removal through the slots in the pins
Another problem associated with standard concrete tie rods is that once the concrete has cured, the ends of the tie rods must be broken off so there are no tie rod protrusions extending from the surfaces of the poured concrete. Both ends of the tie rods must be broken off. The broken off ends of the tie rods become scrap metal which should be disposed of. Because of the tight spaces in which many concrete forms are constructed, such as subsurface retaining walls or foundations, the broken off ends of the tie rods are oftentimes not picked up and disposed of, and continue to litter the construction site after the concrete construction operation has been completed.
Therefore, a need exists for reducing the amount of hardware required in assembly of concrete form systems. Additionally, there is a need to reduce the amount of scrap metal that is produced in concrete form assembly thereby providing a more environmentally friendly construction operation.
In accordance with the present invention, a tie rod is provided for use in concrete construction. The tie rod incorporates wedge shaped ends that may be used in a subsequent concrete construction operation. That is, the ends of the tie rod are broken off after the tie rod has been expended in the construction of a concrete structure, and the ends are then used as wedges in a subsequent concrete construction operation. In accordance with a preferred embodiment of the present invention, the ends of the tie rod each have the tapered configuration that is sized to match standard wedges used in the wedge and pin hardware combinations.
More specifically, the tie rod of the present invention is used in the conventional manner wherein the tie rod stabilizes spaced apart wall forms. After the concrete has cured and the wall forms are disassembled, the ends or ears of the tie rods are broken off, and the broken off ends are then used as wedges in a subsequent concrete construction operation.
In one aspect of the invention, it may be considered an improved tie rod wherein the ends of the tie rod are used as wedges in a subsequent concrete construction. In another aspect of the invention, it may be considered an improved concrete wall form system wherein the tie rods have a dual purpose. In yet another aspect of the present invention, it may be considered as a method of assembling a concrete wall form system wherein the tie rod ends are subsequently used as wedges in the pin and wedge hardware combinations.
As a result of the improved tie rod of the present invention, the requirement to use separate prefabricated wedges is eliminated, thus reducing the overall hardware requirement for a concrete forming operation. Furthermore, scrap metal is reduced because the broken off tie rod ends serve a specific purpose in a subsequent concrete forming operation. Additional motivation for recovering the broken off ends is provided since the ends have a specific utility as hardware. Accordingly, the tie rod of the present invention also provides an environmentally friendly solution to reducing non-recovered scrap at a construction site.
Other advantages and features of the present invention will become more readily apparent from a review of the following detailed description taken in conjunction with the accompanying drawings.
Depending on the type of form pins 40 that are used, the shape and size of the ears 26 may be changed so that the ears conveniently fit within the pin slots 46. For example, it may be necessary to adjust the particular angle of the tapered edges 28, and it may also be necessary to adjust the positions of the openings 23. Furthermore, the particular shapes and depths of the slots 34 may be adjusted to provide the necessary strength for the tie rod when used to support opposing wall panels.
Additionally, the tie rod of the present invention may be modified in terms of the number and spacing of rebar channels 24 to best match the type of wall form to be constructed. As can be appreciated, wall forms are assembled for pouring concrete walls of differing sizes, therefore necessitating the body of the tie rod to be longer or shorter, and to also have a desired number of rebar channels.
It is also contemplated within the present invention that the broken off ears 26 may be used as hardware components in other types of concrete wall form systems. For example, some wall form systems may not require pins, and may only require a single piece of hardware to secure abutting flanges of wall form panels. One or more slot shaped openings may be formed in the panel flanges, and the aligned slots receive a single piece of hardware, such as a wedge shaped element to secure the abutting flanges. Accordingly, the tie rod of the present invention is also ideally suited for these types of concrete wall form systems.
While the tie rod of the present invention has been set forth in a preferred embodiment, those skilled in the art may comprehend various other changes and modifications to the invention, those changes and modifications which are intended to be covered within the scope of the following claims and equivalents thereof.
