U.S. patent application number 12/721702 was filed with the patent office on 2011-09-15 for mesh spacer for reinforced concrete.
This patent application is currently assigned to ROCKY MOUNTAIN PRESTRESS, LLC. Invention is credited to David S. Densmore.
Application Number | 20110219721 12/721702 |
Document ID | / |
Family ID | 44558595 |
Filed Date | 2011-09-15 |
United States Patent
Application |
20110219721 |
Kind Code |
A1 |
Densmore; David S. |
September 15, 2011 |
MESH SPACER FOR REINFORCED CONCRETE
Abstract
A mesh spacer has vertical members extending outward with an
X-shaped cross-section and horizontal dimensions that allow
insertion of the spacer into an opening in a lower layer of
reinforcing mesh in a first orientation. Notches in the lateral
edges of the vertical members engage the reinforcing strands of the
lower layer of mesh in a second rotational orientation of the
spacer. An upper layer of mesh can be placed on the top surfaces of
the vertical members and secured with ties that pass through
openings in the vertical members.
Inventors: |
Densmore; David S.;
(Englewood, CO) |
Assignee: |
ROCKY MOUNTAIN PRESTRESS,
LLC
Denver
CO
|
Family ID: |
44558595 |
Appl. No.: |
12/721702 |
Filed: |
March 11, 2010 |
Current U.S.
Class: |
52/687 ;
52/677 |
Current CPC
Class: |
E04C 5/20 20130101; E04C
5/168 20130101 |
Class at
Publication: |
52/687 ;
52/677 |
International
Class: |
E04C 5/16 20060101
E04C005/16 |
Claims
1. A spacer for positioning a layer of reinforcing mesh in
concrete, wherein said reinforcing mesh has a grid of reinforcing
strands defining an array of openings through the mesh, said spacer
comprising: outwardly extending vertical members having bottom
surfaces, top surfaces and lateral edges; said vertical members
having horizontal dimensions allowing vertical insertion of the
spacer into an opening in a layer of reinforcing mesh in a first
rotational orientation; and notches in the lateral edges of the
vertical members for engaging the reinforcing strands of the layer
of reinforcing mesh in a second rotational orientation of the
spacer.
2. The spacer of claim 1 wherein the vertical members are not
parallel to the reinforcing strands of the layer of reinforcing
mesh in the first rotational orientation.
3. The spacer of claim 1 wherein the vertical members are
substantially parallel to the reinforcing strands of the layer of
reinforcing mesh in the second rotational orientation.
4. The spacer of claim 1 wherein the vertical members are
orthogonal.
5. The spacer of claim 1 further comprising openings in the
vertical members for engaging ties to secure an upper layer of
reinforcing mesh support on the top surfaces of the vertical
members.
6. The spacer of claim 1 wherein the vertical members further
comprise complementary slots to assemble a spacer having an
X-shaped cross-section.
7. The spacer of claim 1 wherein the vertical members are
substantially planar.
8. A spacer for positioning an upper layer and a lower layer of
reinforcing mesh in concrete, wherein said reinforcing mesh has a
grid of reinforcing strands defining an array of openings through
the mesh, said spacer comprising: vertical members extending
outward with a substantially X-shaped cross-section in a horizontal
plane; said vertical members having bottom surfaces, top surfaces
and lateral edges, and further having horizontal dimensions
allowing vertical insertion of the spacer into an opening in a
lower layer of reinforcing mesh in a first rotational orientation;
notches in the lateral edges of the vertical members for engaging
the reinforcing strands of the lower layer of reinforcing mesh in a
second rotational orientation of the spacer; and openings in the
vertical members for engaging ties to secure an upper layer of
reinforcing mesh supported on the top surfaces of the vertical
members.
9. The spacer of claim 8 wherein the vertical members are
orthogonal.
10. The spacer of claim 8 wherein the vertical members are not
parallel to the reinforcing strands of the layer of reinforcing
mesh in the first rotational orientation.
11. The spacer of claim 8 wherein the vertical members are parallel
to the reinforcing strands of the layer of reinforcing mesh in the
second rotational orientation.
12. The spacer of claim 8 wherein the vertical members further
comprise complementary slots for sliding engagement between the
vertical members.
13. The spacer of claim 8 wherein the vertical members are
substantially planar.
14. A spacer for positioning an upper layer and a lower layer of
reinforcing mesh in concrete, wherein said reinforcing mesh has a
rectangular grid of reinforcing strands defining an array of
rectangular openings through the mesh, said spacer comprising: two
vertical members intersecting orthogonally to form a substantially
X-shaped cross-section in a horizontal plane; said vertical members
having bottom surfaces, top surfaces and lateral edges, and further
having horizontal dimensions allowing vertical insertion of the
spacer into an opening in a lower layer of reinforcing mesh in a
first rotational orientation in which the vertical members are not
parallel to the reinforcing strands of the reinforcing mesh;
notches in the lateral edges of the vertical members for engaging
the reinforcing strands of the lower layer of reinforcing mesh in a
second rotational orientation of the spacer in which the vertical
members are substantially parallel to the reinforcing strands of
the reinforcing mesh; and openings in the vertical members for
engaging ties to secure an upper layer of reinforcing mesh support
on the top surfaces of the vertical members.
15. The spacer of claim 14 wherein the vertical members further
comprise complementary slots for sliding engagement between the
vertical members.
16. The spacer of claim 14 wherein the vertical members are
substantially planar.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of
reinforced concrete. More specifically, the present invention
discloses a spacer for positioning reinforcing mesh in
concrete.
[0003] 2. Prior Art
[0004] Reinforcing mesh has long been used to enhance the
structural properties of concrete. This mesh is typically a
rectangular grid of steel reinforcing strands that is positioned in
a concrete form and then becomes embedded in the concrete when the
form is filed with wet concrete. A wide variety of spacers have
been used in the past to hold the reinforcing mesh in a desired
position within a form, so that the mesh will have the desired
location and depth within the finished concrete slab or
component.
[0005] A number of criteria must be considered in designing a
suitable mesh spacer. Large numbers of mesh spacers are required
for large construction projects, which dictates that manufacturing
costs and installation costs at the job site are major factors. In
particular, many conventional mesh spacers are made of steel and
have very sharp edges that can injure workmen. Steel mesh spacers
also rust, which can reduce the structural integrity of the
concrete. The present invention addresses these requirements by
providing a plastic mesh spacer that is simple and expensive to
manufacture and install, and that minimizes the risk of injury to
workers.
SUMMARY OF THE INVENTION
[0006] This invention provides a mesh spacer for reinforced
concrete having vertical members that extend outward with an
X-shaped cross-section. The horizontal dimensions of the spacer
allow it to be inserted into an opening in a lower layer of
reinforcing mesh in a first orientation (i.e., an orientation with
the vertical members diagonal to the reinforcing strands of the
mesh). Notches in the lateral edges of the vertical members engage
the reinforcing strands of the lower layer of mesh in a second
rotational orientation of the spacer (i.e., an orientation with the
vertical members parallel to the reinforcing strands of the mesh).
An upper layer of mesh can be placed on the top surfaces of the
vertical members and secured with ties that pass through openings
in the vertical members.
[0007] These and other advantages, features, and objects of the
present invention will be more readily understood in view of the
following detailed description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention can be more readily understood in
conjunction with the accompanying drawings, in which:
[0009] FIG. 1 is a perspective view of the mesh spacer.
[0010] FIG. 2 is a front elevational view of the mesh spacer.
[0011] FIG. 3 is a side elevational view of the mesh spacer.
[0012] FIG. 4 is a top view of the mesh spacer.
[0013] FIG. 5 is a bottom view of the mesh spacer.
[0014] FIG. 6 is a perspective view showing a mesh spacer being
placed into an opening in a layer of reinforcing mesh 30.
[0015] FIG. 7 is a perspective view corresponding to FIG. 6 showing
the mesh spacer after it has been rotated so that its notches 12
engage the mesh 30.
[0016] FIG. 8 is a perspective view corresponding to FIGS. 6 and 7
showing a second layer of reinforcing mesh 40 placed on top of the
mesh spacer and secured with wire ties 20.
[0017] FIG. 9 is a perspective view showing an array of mesh
spacers supporting a layer of reinforcing mesh 30.
[0018] FIG. 10 is an exploded perspective view showing assembly of
the vertical members 10 and 11 of a mesh spacer.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Turning to FIG. 1, a perspective view is shown of a mesh
spacer embodying the present invention. FIGS. 2 and 3 are
corresponding front and side elevational views of the mesh spacer.
FIGS. 4 and 5 provide top and bottom views, respectively. This
embodiment of the mesh spacer has two substantially planar,
vertical members 10 and 11 that intersect each in other.
Preferably, the vertical members are substantially orthogonal and
have an X-shaped cross-section in the horizontal plane, as shown in
FIGS. 1, 4 and 5.
[0020] The mesh spacer has bottom surfaces that serve as the feet
to support the spacer in a concrete form. It also has top surfaces
for supporting an upper layer of reinforcing mesh 40, as will be
discussed below. A number of windows or openings 14, 16 extend
through the vertical members of the mesh spacer. These openings 14,
16 allow concrete and aggregate to flow around and through the mesh
spacer, thereby reducing the chance of voids and creating a
mechanical bond between the mesh spacer and the concrete.
[0021] The lateral edges of the vertical members 10, 11 each
include at least one notch 12 at a uniform vertical distance from
the bottom of the mesh spacer. These notches 12 should be
sufficiently large to effectively engage the reinforcing mesh grid,
as will be described below. In addition, the overall dimensions of
the mesh spacer in a horizontal plane must be carefully selected
based on the corresponding dimensions of the reinforcing mesh. As
previously mentioned, conventional reinforcing mesh 30 is typically
made of an orthogonal grid of metal reinforcing strands that define
an array of rectangular openings having standard dimensions. The
horizontal cross-sectional dimensions of the mesh spacer must be
sufficiently small to allow the mesh spacer to be inserted into the
openings in the reinforcing mesh 30 when turned in the diagonal
orientation shown in FIG. 6. However, the horizontal
cross-sectional dimensions of the mesh spacer must be sufficiently
large to cause the notches 12 to engage the mesh 30 when the mesh
spacer is rotated into the orientation shown in FIG. 7. In
particular, the overall length of the vertical members must be
slightly longer than the corresponding dimensions of the mesh grid,
so that the notches 12 can engage the reinforcing mesh 30 in this
second rotational orientation.
[0022] In use, each mesh spacer is initially inserted into an
opening in a layer of reinforcing mesh 30 as shown in FIG. 6. The
mesh spacer is inserted along an axis normal to the plane of the
mesh (e.g., vertically, if the mesh is horizontal). The dimensions
of the mesh spacer allow it to fit through the openings in the mesh
30 when the mesh spacer is held in an rotational orientation about
the normal (vertical) axis so that the vertical members 10, 11 of
the mesh spacer are substantially non-parallel to the mesh grid.
Optimally, the vertical members 10, 11 are oriented diagonally
(e.g., in a roughly 45 degree orientation) with respect to the grid
of the mesh 30 in this first rotational orientation.
[0023] After the mesh spacer has been inserted to an elevation at
which its notches 12 align with the mesh 30, the mesh spacer is
rotated about the normal axis as shown in FIG. 7, so that the
notches 12 of the mesh spacer engage the mesh 30. This normally
entails a rotation of about a quarter turn (i.e., about 45
degrees), so that the vertical members 10, 11 are generally
parallel with the grid of the mesh 30 in this second rotational
orientation. The bottom surfaces of the vertical members 10, 11 of
the mesh spacer contact the floor of the concrete form. The
portions of the vertical members 10, 11 of the mesh spacer below
the notches 12 support and elevate the mesh 30 a predetermined
distance above the floor of the concrete form. The height of these
portions of the vertical members 10, 11 below the notches 12
determines the depth at which the reinforcing mesh 30 will be in
the finished concrete slab.
[0024] A second, upper layer of reinforcing mesh 40 can then be
placed atop the mesh spacers and secured with a number of ties 20,
as shown in FIG. 8. The second layer of mesh 40 rests against the
top surfaces of the mesh spacer. The ties 20 pass through the upper
openings 16 in the mesh spacer and are secured around the upper
layer of mesh 40. The separation distance between the layers of
mesh 30 and 40 is determined by the vertical spacing between the
notches 12 and the upper surfaces of the mesh spacer.
[0025] An array of mesh spacers may be used to support a large
pieces of reinforcing mesh 30 as illustrated in FIG. 9. A
three-foot spacing between mesh spacers is sufficient to allow a
large man to walk on the mesh after final assembly.
[0026] It should be noted that the mesh spacer can be easily
removed and relocated, if needed. It can be readily detached from
the upper layer of reinforcing mesh 40 by cutting or untwisting the
ties 20. The mesh spacer can also be readily detached from the
lower layer of reinforcing mesh 30 by rotating the mesh spacer a
quarter turn to a diagonal orientation and then lifting it out of
the opening in the mesh 30.
[0027] After assembly of the mesh spacers and reinforcing mesh,
concrete can then be poured into the form to cover the mesh spacers
and both layers of reinforcing mesh 30, 40. The openings 14, 16 in
the mesh spacer allow concrete to freely flow through the mesh
spacer so that it becomes an integral part of the finished concrete
slab. The mesh spacers remain embedded in the concrete slab along
with the reinforcing mesh 30, 40 as the concrete cures. It should
be noted that the mesh spacers can be stacked in a variety of
configurations, if additional layers of reinforcing mesh are
required for a particular job.
[0028] The mesh spacer can be made of any suitable material,
including plastic, metal, or composite materials. In the preferred
embodiment, the mesh spacer is made of polypropylene. This material
is light weight, relatively inexpensive, dimensionally consistent,
doesn't rust, and has no sharp edges that might injure workers.
[0029] The mesh spacer can be formed as a single piece or assembled
from two or more planar pieces. In the preferred embodiment shown
in the figures, the vertical members are mold for plastic as two
separate pieces. Complementary slots 18, 19 in both pieces enable
the vertical members 10, 11 to slide together in an orthogonal
arrangement as depicted in FIG. 10 (i.e., to create an assembly
having a substantially X-shaped cross-section in the horizontal
plane). The slots 18, 19 narrow with a slight taper (e.g., about 5
degrees) to hold the vertical members 10, 11 together, and can also
be equipped with locking features to create a snap fit. Small pegs
17 help to maintain proper alignment and positioning of the
vertical members 10, 11 after assembly.
[0030] It should be understood that alternative shapes and
configurations of the mesh spacer and the vertical members could be
readily substituted. For example, the vertical members are not
necessarily planar or orthogonal. The number of vertical members
could also be changed. More than one notch 12 could be provided on
each lateral edge of the vertical members to accommodate a variety
of elevations for the lower reinforcing mesh, or allow a plurality
of lower mesh layers. The structural rigidity of the mesh spacer
could be enhanced by including a central body or shaft with
vertical members extending radially outward.
[0031] The above disclosure sets forth a number of embodiments of
the present invention described in detail with respect to the
accompanying drawings. Those skilled in this art will appreciate
that various changes, modifications, other structural arrangements,
and other embodiments could be practiced under the teachings of the
present invention without departing from the scope of this
invention as set forth in the following claims.
* * * * *