Wire rebar chair
A unitary wire chair is disclosed for supporting concrete reinforcing rebar or the like above a supporting surface onto which concrete is poured. The unitary wire chair is so constructed such that it may be snapped or otherwise secured onto the rebar or other concrete reinforcing element and retained thereon without the use of any tie wire or other attachment devices.
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The present invention relates to spacers, or so-called chairs, that are used in construction for the support of rebar, post-tension cables or wire mesh. More particularly, the present invention relates to chairs made of wire that are used for the support of rebar, post-tension cables, or wire mesh in poured concrete.
BACKGROUND OF THE INVENTIONSpacers, or so-called chairs, are commonly used in the concrete construction industry for the support of rebar or post-tension cables or mesh above a surface onto which concrete is to be poured. Typically, rebar, cable or mesh, when used to reinforce concrete, must be supported above the surface onto which the concrete is poured. Chairs are generally used with poured concrete decks, pre-cast work, and bridges, roads or so-called slab-on-grade applications. In use, a rebar supporting surface on the chair supports the rebar while the base of the chair rests on the deck or surface to which the concrete is to be applied. When the concrete is poured, the chair maintains the cable or rebar a proper distance above the supporting surface.
Currently, one of the most popular chairs used to support rebar is made from a pair of bent wires. A first bent wire is generally in the shape of an inverted U and has a recessed surface in the cross bar at the top onto which the rebar is located. The sides of the U-shaped wire support the recessed cross bar in an upright condition above the supporting surface. A second wire is formed as an inverted U and is welded to the bottom edge of the cross bar of the first wire and extends at 90° to that cross bar. The second wire also has vertically extending legs which support the second wire above the supporting surface. Generally, to prevent the rebar supported from this type of wire chair during pouring of the concrete, the rebar is tied to the supporting surface of the chair by a tie wire.
One problem with this type of wire chair is that it is relatively expensive to manufacture because of the welding required in the course of its manufacture, but also because it requires substantial hand labor to manually attach the rebar to the chair by means of tie wires. It has therefore been an objective of this invention to provide a wire chair which is less costly to manufacture and which eliminates the need for tie wires to attach the wire chair to the rebar.
There have been rebar supporting chairs manufactured which do not require the use of tie wires for attachment of the chair to the rebar. For example, as disclosed in U.S. Pat. No. 5,893,252, there are chairs which may be snap-fit onto the rebar so as to support that rebar above a supporting surface, but such snap-on-type of rebar supporting chairs have generally been made of plastic and are substantially more expensive and difficult to manufacture than wire rebar supporting chairs. It has therefore been another objective of this invention to provide a wire rebar supporting chair which may be snapped onto a rebar and frictionally held thereon without the need for tie wires or a complex plastic snap-fit connection.
SUMMARY OF THE INVENTIONThe wire rebar chairs of this invention are formed from a single unitary wire which supports a concrete reinforcing rebar or the like and which are so constructed that they may be snapped onto or otherwise secured onto the rebar or other concrete reinforcing element and retained thereon without the use of tie wires or other attachment devices. To that end, one embodiment of the invention comprises three parallel cross bars, a central one of which is adapted to be received atop a rebar and the other two parallel cross bars of which are adapted to be received on the underside of the rebar with connecting bars connected to opposite ends of the central one of the three parallel cross bars and riser bars extending downwardly away from the ends of each of the other two parallel cross bars, which riser bars terminate in a supporting foot. The supporting foot is intended to rest upon the supporting surface while concrete is poured onto that supporting surface. Preferably, this wire chair is heat-treated after formation of the chair so as to impart spring-like qualities to the wire chair, such that when secured onto a rebar, the spring-like qualities retain the wire chair on the rebar against any forces which it might otherwise tend to displace it.
Another embodiment of the invention comprises a single unitary wire formed as two riser bars extending upwardly from opposite ends of a support foot section of wire. The two upwardly extending riser bars terminate in generally U-shaped loops which snap over and onto opposite sides of a rebar or like concrete reinforcing wire.
In yet another embodiment of the invention, a single unitary wire has a straight upper horizontal bar section from the opposite ends of which are formed generally U-shaped loops which snap over a rebar or rebar-like concrete reinforcing wire. At the end of the loops opposite the straight horizontal bar section, riser bars extend generally downwardly to supporting foot sections of wire.
As a still further modification of the embodiment described immediately hereinabove, the generally U-shaped loops are connected to a generally V-shaped nose section of the chair wire rather than a straight upper bar section of the unitary wire.
BRIEF DESCRIPTION OF THE DRAWINGSThese and other variations and embodiments of this invention will be more readily apparent from the following description of the drawings, in which:
With reference first to
The ends of the outermost cross bars 16 and 20 opposite the end connected to the connector bars 22 and 24 is connected via ninety degree (90°) bends 34, 36, respectively, to riser bars 40, 42. The riser bars 40, 42 extend downwardly and outwardly away from the cross bars to which they are connected and terminate in supporting feet 44, 46. Each supporting foot 44, 46 is connected to the lower end of the riser bars 40, 42, respectively, by ninety degree (90°) bends 48 and 50, in the wire, respectively. See
In the embodiment of the invention illustrated in
As may be seen most clearly in
In order to accommodate the chair to differing applications, the angles α and β may vary, as well as the length of the riser bars and connector bars. For example, if a smaller rebar or concrete reinforcing wire or element is utilized, the connector bars 22 and 24 will be shortened and/or the angle a increased to as to accommodate the smaller diameter rebar or wire. And similarly, if the rebar or concrete reinforcing element is to be increased in elevation relative to the supporting surface 14, the length of the riser bars 40 and 42 would be increased and/or the angle β decreased to accomplish the increased elevation of the supported rebar or reinforcing element.
In one preferred embodiment of this invention, after formation of the chair 12, the chair is preferably subjected to a heat treatment so as to improve and increase the formed stability of the formed chair. One suitable heat treatment involves subjecting the formed chair to a temperature of 450 to 550° F. and then cooling the chair to room temperature so as to result in its having spring-like resilient qualities. Not only does this heat treatment increase the forms or shaped stability of the chair, but it better enables the chair to grip a rebar 10 inserted into the gaps 56, 58 between the cross bars 16, 18, 20 as explained more fully hereinafter.
With reference now to
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In the embodiment of
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It will readily be apparent to persons skilled in the art that while we have described several embodiments of our invention, other changes and modifications may be made without departing from the spirit of our invention. Therefore, we do not intend it to be limited except by the scope of the following appended claims.
Claims
1. A unitary wire chair for supporting concrete reinforcing rebar or the like above a supporting surface while concrete is poured onto that supporting surface, which chair comprises:
- at least three parallel cross bars connected by two connecting bars, a central one of said three parallel cross bars being adapted to be received atop a rebar and the other two parallel cross bars being adapted to be received on the underside of said rebar; and
- riser bars extending downwardly away from an end of each of said other two parallel cross bars.
2. The unitary wire chair of claim 1 wherein said two connecting bars are connected to opposite ends of said central one of said three parallel cross bars.
3. The unitary wire chair of claim 1 wherein each of said riser bars is connected at its lower end to a supporting foot.
4. The unitary wire chair of claim 3 wherein each supporting foot comprises a linear bar which extends parallel to said three parallel cross bars.
5. The unitary wire chair of claim 1 wherein said chair is adapted to be secured onto a rebar by locating the rebar between two of said three parallel cross bars and then rotating said chair 90° to lock said chair onto said rebar.
6. The unitary wire chair of claim 1 wherein said chair is subjected to heat treatment after formation of said chair.
7. The unitary wire chair of claim 6 wherein said heat treatment comprises heating said chair to a temperature of between 450° to 550° F. and then cooling said chair to impart improved form stability to said chair.
8. A unitary wire chair for supporting a concrete reinforcement element above a supporting surface while concrete is poured onto that supporting surface, which chair comprises:
- at least three parallel cross bars connected by two connecting bars, a central one of said three parallel cross bars being adapted to be received atop a reinforcement element and the other two parallel cross bars being adapted to be received on the underside of said reinforcement element; and
- riser bars extending downwardly away from an end of each of said other two parallel cross bars.
9. The unitary wire chair of claim 8 wherein said two connecting bars are connected to opposite ends of said central one of said three parallel cross bars.
10. The unitary wire chair of claim 8 wherein each of said riser bars is connected at its lower end to a supporting foot.
11. The unitary wire chair of claim 10 wherein each supporting foot comprises a linear bar which extends parallel to said three parallel cross bars.
12. The unitary wire chair of claim 8 wherein said chair is adapted to be secured onto a reinforcement element by locating the reinforcement element between two of said three parallel cross bars and then rotating said chair 90° to lock said chair onto said reinforcement element.
13. The unitary wire chair of claim 8 wherein said chair is subjected to heat treatment after formation of said chair.
14. The unitary wire chair of claim 13 wherein said heat treatment comprises heating said chair to a temperature of between 450° to 550° F. and then cooling said chair to impart improved form stability to said chair.
15. A unitary wire chair for supporting a concrete reinforcing element above a supporting surface, which chair comprises:
- at least three parallel cross bars connected by at least two connecting bars, at least one of said parallel cross bars being adapted to be received atop a reinforcing element and at least two parallel cross bars being adapted to be received on the underside of said reinforcing element; and
- riser bars extending downwardly away from an end of at least two of said parallel cross bars.
16. The unitary wire chair of claim 15 wherein each of said riser bars is connected at its lower end to a supporting foot.
17. The unitary wire chair of claim 16 wherein each supporting foot comprises a linear bar which extends parallel to said three parallel cross bars.
18. A unitary wire chair for supporting concrete reinforcing element above a supporting surface while concrete is poured onto that supporting surface, which chair comprises:
- at least three parallel cross bars connected by two connecting bars, a central one of said three parallel cross bars being adapted to be received atop a concrete reinforcing element and the other two of said three parallel cross bars being adapted to be received on the underside of said concrete reinforcing element, said two connecting bars being connected to opposite ends of said central one of said three parallel cross bars; and
- a pair of riser bars extending downwardly away from an end of each of said other two parallel cross bars.
19. The unitary wire chair of claim 18 wherein each of said riser bars is connected at its lower end to a supporting foot.
20. A unitary wire chair for supporting concrete reinforcing rebar or the like above a supporting surface while concrete is poured onto that supporting surface, which chair comprises:
- at least three parallel cross bars connected by two connecting bars, said two connecting bars being connected to opposite ends of a central one of said three parallel cross bars; and
- a riser bar extending downwardly away from an end of each of said other two parallel cross bars.
21. The unitary wire chair of claim 20 wherein each of said riser bars is connected at its lower end to a supporting foot.
22. The unitary wire chair of claim 21 wherein each supporting foot comprises a linear bar which extends parallel to said three parallel cross bars.
23. The unitary wire chair of claim 21 wherein said chair is adapted to be secured onto a rebar or the like by locating the rebar between two of said three parallel cross bars and then rotating said chair 90° to lock said chair onto said rebar or the like.
24. A unitary wire chair for supporting concrete reinforcing rebar or the like above a supporting surface, which chair comprises:
- a central section of said wire having generally U-shaped loops formed at its opposite ends, each of said loops terminating in a generally vertically extending riser bar; and
- a supporting foot formed on an end of each riser bar.
25. The unitary wire chair of claim 24 wherein said central section of wire is a straight linear section of wire.
26. The unitary wire chair of claim 24 wherein said central section of wire is generally V-shaped.
27. A unitary wire chair for supporting concrete reinforcing rebar or the like above a supporting surface, which chair comprises:
- a lower central foot supporting section;
- riser bars extending upwardly from said lower central foot section;
- generally U-shaped loops formed on the upper ends of each of said riser bars, said loops being adapted to be snap-fit onto a rebar or other type of concrete reinforcing wire or rod.
28. A unitary wire chair for supporting concrete reinforcing rebar or the like, said chair being formed from a single length of wire having at least one portion of the wire so configured that it may be snap-fit onto a rebar or the like and retained thereon without any other attachment device.
29. The unitary wire chair of claim 28 wherein said chair comprises riser bars which support said snap-fit portion spaced from at least one supporting foot portion of said chair.
Type: Application
Filed: Jan 11, 2006
Publication Date: Jul 12, 2007
Applicant: L&P Property Management Company (South Gate, CA)
Inventors: Niels Mossbeck (Carthage, MO), Darrell Richmond (Carthage, MO)
Application Number: 11/329,570
International Classification: E04C 5/16 (20060101);