Static structures (e.g. – buildings) – Openwork; e.g. – truss – trellis – grille – screen – frame – or... – Spacer-positioner; e.g. – rebar chair
Reexamination Certificate
1999-05-07
2001-09-04
Stephan, Beth A. (Department: 3635)
Static structures (e.g., buildings)
Openwork; e.g., truss, trellis, grille, screen, frame, or...
Spacer-positioner; e.g., rebar chair
C052S686000, C052S687000, C052S689000, C052S688000
Reexamination Certificate
active
06282860
ABSTRACT:
FIELD OF THE INVENTION
Wire mesh supports, more particularly a wire mesh support intended to engage wire strands in cup-like members. The wire mesh engages the support at four points just outside the intersection of the wire strands.
SUMMARY OF THE INVENTION
Wire mesh, such as that used to reinforce poured concrete, is made up of wire strands arranged in a lattice pattern, that is, with one set of parallel wires strands; meeting a second set of parallel wires strands in generally perpendicular relation. When concrete is poured, wire mesh is laid down to help reinforce the concrete. However, the wire mesh is best supported above the floor of the slab and below the top of the slab. Prior art reinforcement is intended to support the wire mesh by supporting a single strand above the ground during the concrete pouring process. However, it is the inventor's experience that when such supports are used they are sometimes ineffective. More specifically, they care fall over and allow the mesh to sag or fall.
The foundation of a residential structure is affected by many forces acting on it from different axes. Engineering calculations show that concrete can be in compression or tension simultaneously. To avoid the failure of the concrete foundation, steel is added to the foundation to increase the carrying capacity of the concrete, principally in tension. The American Concrete Institute (ACI) in Section 318 of their code specifies that the rebar in a slab-on-grade foundation must be placed at the midpoint of the depth of the foundation. For example, in a four inch foundation slab, the rebar mat would normally be placed at two inch depth. Also, the ACI Concrete Code calls for the steel reinforcement in the concrete beans at all exterior and interior beams to have sufficient cover to avoid exposing needlessly the steel to the effects of moisture-penetrating corrosion. Once the steel is exposed to the effects of chemical-laden moisture, corrosion starts taking effect.
Applicant has, therefore, invented a new product which is effective in the process of laying down wire mesh and pouring concrete foundations. Applicant's new invention will help maintain engagement of wire mesh in the proper position near the middle part of the concrete foundation, between the base and the top of the poured slab.
Many contractors, because of the lack of a product(s) that places the steel at the correct depth in a uniform and efficient manner, do not install the steel reinforcement correctly. Many times, concrete laborers use stones (in different sizes) or pieces of broken bricks to support the steel mat (or cage in foundation beams) at the perpendicular intersection of rebar pieces. Since the pieces of stone or bricks are not uniform in size, the placement of the rebar ends up uneven. Another problem is that, while the foundation is being prepared, the workers step on the installed steel to go across the foundation. Sometimes this leads to the steel rebar falling off the support (stones or bricks). During the placement of the concrete, the workers must labor on top of the mat in a hurry. Consequently, the rebar might end up not at the mid-depth level as prescribed in the specifications. There are concrete foundation chairs out in the market. Some of the chairs perform well under ideal circumstances. But these chairs, either metal or plastic, normally have a single installation purpose.
Applicant's product is manufactured of heavy plastic. An illustration of the product and its use is set forth in
FIGS. 1
to
9
. It differs from the prior in that it is a single support which is intended to engage at least two stands of wire that are perpendicular to one another and to specifically engage those two strands at two points of typically equal distance from the intersection of the two strands. Further, where Applicant's wire mesh support engages the individual section of wires, a cup-like indent is provided to which the wire can either rest in or “snap” into for positive retainment.
It can be appreciated that by providing a wire mesh support which, instead of supporting a single wire strand at a single support point, provides a wire mesh support which engages perpendicularly aligned strands at four points equal distance from the junction of the strands, any movement of the wire mesh after the placement of a multiplicity of supports beneath the wire mesh would tend to cause the wire mesh supports to “slide” rather than topple over like the prior art.
REFERENCES:
patent: 1070921 (1913-08-01), Saltiel
patent: 3693310 (1972-09-01), Middleton
patent: 4831803 (1989-05-01), Leonardis
patent: 5107654 (1992-04-01), Leonardis
patent: 5291715 (1994-03-01), Basile
patent: 5729949 (1998-03-01), Hartzheim
Dorsey Dennis L.
Jackson & Walker, LLP
Stephan Beth A.
LandOfFree
Wire mesh support does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Wire mesh support, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wire mesh support will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2471230