Patent Application
20190136534
This invention relates generally to rebar support devices or chairs, and more specifically to a rebar support apparatus comprising a tower and a base, each capable of holding rebar members at a predefined height above a concrete form or granular surface, respectively, the two further capable of being locked together by use of simple manual force, the assembly thereof acting in tower-base duplex fashion in the formation of rebar grids prior to concrete pouring.
Steel reinforcing bars, commonly referred to as rebars, have long been used to improve the strength and durability of a wide range of concrete structures such as footings, foundations, walkways, platforms, support beams, building frames and the like, making reinforced concrete one of the most common building material used in the construction industry. The use of rebar in these structures involves the construction and securing of rebar grids at various heights above the bottom of a concrete form or granular base. Rebar support devices are used to position and hold rebar members in the formation of said reinforcing grids and therefore play an important role in the production of reinforced concrete structures.
Rebar support devices may be broadly grouped into three principal categories: 1. Unitary devices providing one or more levels of rebar support and designed for placement on a granular surface, such as a gravel bed. 2. Unitary devices providing one or more levels of rebar support and designed for placement on a solid surface, such as the bottom of a concrete form. 3. Multiple component devices which provide one or more levels of rebar support and also the means to configure the component parts thereof to permit use on either a granular surface or a solid surface in the construction of rebar grids.
It is appreciated that numerous rebar support devices are known in the art. Examples are U.S. Pat. No. 3,673,753 to Anderson, U.S. Pat. No. 6,354,054 to Verelli and Verelli, U.S. Pat. No. 6,684,594 to Sorkin, U.S. Pat. No. 7,451,580 to Kelly et al. and U.S. Pat. No. 7,870,702 to McKay.
Exemplary rebar support devices providing one or more levels of rebar support and designed for placement on a granular surface, such as a gravel bed, may be found in U.S. Pat. Nos. 3,673,753, 6,684,594 and 7,870,702, the disclosure provided in U.S. Pat. No. 3,673,753, being representative of this category. In U.S. Pat. No. 3,673,753, a concrete rebar support device is disclosed comprising a unitary base with upright pedestal, said pedestal portion having lower and upper clamping means at its apex, defining first and second intersecting passageways disposed normal to each other, for simultaneously receiving rebar members therein. Resilient detents and hook means incorporated in said lower and upper clamping means assist in keeping rebars in place once positioned.
In U.S. Pat. No. 6,354,054, there is disclosed a unitary rebar chair comprising a tower with four legs between which there are defined two intersecting passages for simultaneously receiving the intersecting portions of two rebars normal to each other, said tower further having a saddle formation at its apex to accept one or two additional rebar members to form a multilevel rebar grid. U.S. Pat. No. 6,354,054 is exemplary of unitary devices providing one or more levels of rebar support and designed for placement on a solid surface, such as the bottom of a concrete form.
U.S. Pat. No. 7,451,580, is exemplary of a multiple component device providing one or more levels of rebar support and means to configure the component parts thereof to permit use on either a solid or granular surface in the construction of rebar grids. In this disclosure a rebar chair comprises a first component tower with rebar cradle means at its top surface and four legs which diverge down from the top surface, terminating in tapered feet for minimal contact with a concrete form. A second component base, described therein as a sand plate and also known in the art as a bearing plate, has radially extending slots formed to engage the feet of first component tower structure, the combination first component tower and second component base allowing the assembly thereof to be used on a granular surface.
In summary, the prior art has evolved to provide varied and effective means for the positioning and support of rebar members in the construction of rebar grids in reinforced concrete structures. However, what has not been adequately addressed is the need for a simple and effective rebar support system comprising a minimal number of component parts, each component part individually providing means for rebar support in specific applications, the cooperative combination of the component parts thereof further extending the functionality and range of applications in the formation of rebar grids on different types of surfaces.
It is thus an object of the present invention to provide a rebar support system for the reinforcement of concrete structures, comprising a rebar support tower and a rebar support base, individually capable of supporting rebar members at a predefined height within a range of possible heights, first component rebar support tower being ideally suited for use with concrete forms and second component rebar support base being ideally suited for use with granular surfaces, the two further capable of acting together in tower-base duplex fashion in the construction of multilevel rebar grids on granular surfaces.
It is a further object of the present invention that said first component rebar support tower is capable of simultaneously receiving and supporting the intersecting portions of two sets of rebar members, one set at its apex and the other through its lower structure, each set comprising rebars which are normal to each other.
It is a further object of the present invention that said first component rebar support tower is suitably adapted for use with a concrete form, leaving a minimum of contact footprints after form removal, while still providing the strength and stability for the required functions of rebar support, grid construction and concrete pouring.
It is a further object of the present invention that second component rebar support base is capable of receiving the intersecting segments of two rebars which are normal to each other.
It is a further object of the present invention that said second component rebar support base is suitably adapted for use on a granular surface, such as a gravel bed, having sufficient surface area in contact with such a surface to provide strength and stability for the required functions of rebar support, grid construction and concrete pouring.
It is yet a further object of the present invention that said first component rebar support tower and second component rebar support base provide complementary means for simple manual attachment of the two thereof to form a secure, yet detachable tower-base assembly in multiple rebar grid configurations.
To achieve the forgoing objects, and in accordance with the purposes of the invention as embodied and broadly described herein, there is provided a rebar support system for the reinforcement of concrete structures, comprising a first component rebar support tower and a second component rebar support base.
According to an advantageous embodiment of first component rebar support tower according to the invention, the structure comprises four legs between which there are defined two intersecting passages, the legs being open-ended at the bottom and forming bidirectional arches at the top of said intersecting passages, said first component rebar support tower further having a saddle formation at its apex, the intersecting passages, bidirectional arches and saddle formation providing means for receiving the intersecting segments of rebars which are normal to each other.
According to another advantageous embodiment of first component rebar support tower according to the invention, there is provided a tapered and angled profile at the bottom of each leg to minimize the area of contact when used with a concrete form.
According to an advantageous embodiment of second component rebar support base according to the invention, there is provided a platform with centrally rising bidirectional saddle formations for receiving the intersecting segments of rebars which are normal to each other.
According to yet another advantageous embodiment according to the invention, there is provided hook receptacle means and guide ridges in first component rebar support tower and corresponding insert hooks and guide tabs in second component rebar support base, providing means for the manual attachment of the two structures to form a rigid, yet detachable tower-base assembly in the formation of multiple rebar grid configurations.
Additional objects, features and advantages of the present invention will become more fully apparent from the accompanying description and appended claims taken in conjunction with the following drawings, wherein like reference characters indicate like elements throughout.
(a) Is a front view of one side of the assembly, the opposite side being identical to that shown.
(b) Is a front view of the side adjacent to the side illustrated in (a), the opposite side being identical to that shown.
(c) Is a bottom angled view of a tower-base assembly.
(d) Is a top view of a tower-base assembly.
(e) Is a top angled view of a tower-base assembly.
In
To further assist one skilled in the art and provide the basis for the detailed descriptions of the preferred embodiments and advantageous features of the invention which follow, there is illustrated in
By way of example and not limitation, rebar support tower 100 and rebar support base 200 are preferably injection moulded out of high-strength thermoplastic material such as polyurethane, polypropylene, nylon or the like. Similarly, rebar support tower 100 and rebar support base 200 could be manufactured in various sizes to provide a range of practical rebar placement heights above a supporting surface, for example 9½″-12¼″ and 2½″-3″, respectively, in increments of ¼″, the tower-base assembly thereof providing means for two levels of intersecting rebars, each level within the exemplary ranges indicated.
In
Rebar support tower 100 illustrated in
The lower portion of each leg of rebar support tower 100 provides means for interconnection with rebar support base 200, said means comprising hook receptacle holes 118, positioning and retaining surfaces 120 and 122, and guide ridges 124 and 126, which assist in aligning first component rebar support tower 100 and second component rebar support base 200 in forming a tower-base assembly, ridges 124, 126, 128 and 130 further providing structural strength and dimensional stability to rebar support tower 100.
In
In a preferred embodiment of rebar support tower 100, there is provided means for reducing the area of contact when used with a concrete form, in order to reduce rebar support footprints on the bottom of a concrete structure after form removal.
In
It is apparent from the foregoing description that the apparatus of the present invention may incorporate different variants to fulfill a number of specific functional requirements encountered in the reinforcement of concrete structures. In particular, the two component apparatus disclosed herein comprises a rebar support tower having small footprint means, allowing it to function individually on a solid surface, such as a concrete form, providing five practical rebar support variants: 1. A single rebar member in its upper structure. 2. A single rebar member in each of its upper and lower structure. 3. A single rebar member in its upper structure and two intersecting rebars in its lower structure. 4. A single rebar member in its lower structure and two intersecting rebars in its upper structure. 5. Two intersecting rebar members in each of its upper and lower structure. The rebar support base of the invention provides a platform and rebar support means, allowing it to function individually on a granular surface, such as a gravel bed, providing two practical rebar support variants: 1. A single rebar member in its support structure. 2. Two intersecting rebar members in its support structure.
The rebar support tower and rebar support base of the invention comprise cooperative means for interconnecting one with the other in tower-base duplex fashion to hold rebar members at predefined heights in the construction of multilevel rebar grids on a granular surface, the practical functional variants of the assembly thereof being: 1. A single rebar member in its upper level. 2. A single rebar member in each of the upper and lower levels. 3. A single rebar member in the upper level and a pair of intersecting rebars at its lower level. 4. A single rebar member in the lower level and a pair of intersecting rebars at its upper level. 5. Two intersecting rebar members in each of its upper and lower levels.
From the foregoing description, it will be appreciated that this invention embraces the objectives of novelty and commercial/industrial utility. From a technical perspective, it is noted that from a two-component apparatus in which each component is individually capable of independent use, the two providing a combined total of seven possible functional variants when used individually, there results a total number of twelve possible functional variants with the simple manual interconnection of the two components thereof. Therefore, it will also be appreciated that this invention will have tangible advantages and benefits, both commercially and for the general public, through reduced inventory costs for suppliers and end-users, greater work-site efficiency and enhanced reliability, lower maintenance costs and increased life of end-product concrete structures, ubiquitous in cities today.
Finally, it will be appreciated that the principles of the invention as described herein can be applied in many ways and that the invention is not limited to those of its modes of employment, embodiments and uses which have been described explicitly. Rather, it encompasses all changes and modifications which may be derived by those skilled in the art and are within the spirit, scope and extent of the invention as set forth in the following claims.
