U.S. patent application number 13/347878 was filed with the patent office on 2013-07-11 for reinforcing bracket for lifting anchors in reinforced concrete walls.
This patent application is currently assigned to ROCKY MOUNTAIN PRESTRESS, LLC. The applicant listed for this patent is David S. Densmore, James P. Linskens. Invention is credited to David S. Densmore, James P. Linskens.
Application Number | 20130174499 13/347878 |
Document ID | / |
Family ID | 48742930 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130174499 |
Kind Code |
A1 |
Densmore; David S. ; et
al. |
July 11, 2013 |
Reinforcing Bracket for Lifting Anchors in Reinforced Concrete
Walls
Abstract
A reinforcing bracket has a planar central portion extending
parallel to the reinforcing members with at least one central
opening to receive a lifting anchor. Two V-shaped wings extend out
of the plane of the central portion from the opposing ends of the
central portion. Sets of aligned openings pass through these wings
to receive reinforcing members.
Inventors: |
Densmore; David S.;
(Englewood, CO) ; Linskens; James P.; (Golden,
CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Densmore; David S.
Linskens; James P. |
Englewood
Golden |
CO
CO |
US
US |
|
|
Assignee: |
ROCKY MOUNTAIN PRESTRESS,
LLC
Denver
CO
|
Family ID: |
48742930 |
Appl. No.: |
13/347878 |
Filed: |
January 11, 2012 |
Current U.S.
Class: |
52/125.4 ;
52/699 |
Current CPC
Class: |
E04G 21/142 20130101;
E04C 5/163 20130101 |
Class at
Publication: |
52/125.4 ;
52/699 |
International
Class: |
E04C 5/16 20060101
E04C005/16; E04B 1/41 20060101 E04B001/41; E04G 21/14 20060101
E04G021/14 |
Claims
1. A reinforcing bracket for use with a lifting anchor embedded in
a concrete component having a substantially planar edge and
reinforcing members running parallel to the edge, said reinforcing
bracket comprising: a substantially planar central portion
extending between opposing ends parallel to the reinforcing
members, with the plane of the central portion extending parallel
to the planar edge of the concrete component; at least one central
opening through the central portion to receive a lifting anchor;
two substantially planar wings extending out of the plane of the
central portion from the opposing ends of the central portion; and
at least one set of reinforcing member openings through the wings
aligned to receive a reinforcing member.
2. The reinforcing bracket of claim 1 wherein at least one of the
wings has a V-shaped cross-section comprising: a substantially
planar first wing portion extending out of the plane of the central
portion; a substantially planar second wing portion continuing from
the first wing portion and returning toward the plane of the
central portion; and at least one set of reinforcing member
openings through the first wing portion and second wing portion
aligned to receive a reinforcing member.
3. The reinforcing bracket of claim 1 wherein the central portion
and wings are formed from a single rectangular piece of
material.
4. The reinforcing bracket of claim 1 wherein the central opening
comprises a keyed shape allowing insertion of a lifting anchor
through the central portion in a first rotational orientation, and
engaging the lifting anchor to the lifting bracket when the lifting
anchor is rotated to a second rotational orientation.
5. The reinforcing bracket of claim 1 wherein the central portion
comprises a plurality of openings to receive the legs of a loop
lifting anchor.
6. A reinforcing bracket for use with a lifting anchor embedded in
a concrete component having a substantially planar edge and
reinforcing members running parallel to the edge, said reinforcing
bracket comprising: a substantially planar central portion
extending between opposing ends parallel to the reinforcing
members, with the plane of the central portion extending parallel
to the planar edge of the concrete component; at least one central
opening through the central portion to receive a lifting anchor;
two V-shaped wings extending out of the plane of the central
portion from the opposing ends of the central portion; and at least
one set of reinforcing member openings through the wings aligned to
receive a reinforcing member.
7. The reinforcing bracket of claim 6 wherein at least one of the
wings comprises: a substantially planar first wing portion
extending out of the plane of the central portion; and a
substantially planar second wing portion continuing from the first
wing portion and returning toward the plane of the central
portion.
8. The reinforcing bracket of claim 6 wherein the central portion
and wings are formed from a single rectangular piece of
material.
9. The reinforcing bracket of claim 6 wherein the central opening
comprises a keyed shape allowing insertion of a lifting anchor
through the central portion in a first rotational orientation, and
engaging the lifting anchor to the lifting bracket when the lifting
anchor is rotated to a second rotational orientation.
10. The reinforcing bracket of claim 6 wherein the central portion
comprises a plurality of openings to receive the legs of a loop
lifting anchor.
11. A reinforcing bracket for use with a lifting anchor embedded in
a concrete component having a substantially planar edge and
reinforcing members running parallel to the edge, said reinforcing
bracket comprising: a substantially planar central portion
extending between opposing ends parallel to the reinforcing
members, with the plane of the central portion extending parallel
to the planar edge of the concrete component at least one central
opening through the central portion to receive a lifting anchor;
two wings extending from the opposing ends of the central portion,
each wing having: (a) a substantially planar first wing portion
extending out of the plane of the central portion; and (b) a
substantially planar second wing portion continuing from the first
wing portion and returning toward the plane of the central portion;
and at least one set of reinforcing member openings through the
wings aligned to receive a reinforcing member.
12. The reinforcing bracket of claim 11 wherein the first wing
portion and second wing portion form a structure having a
substantially V-shaped cross-section.
13. The reinforcing bracket of claim 11 wherein the central portion
and second wings are formed from a single rectangular piece of
material.
14. The reinforcing bracket of claim 11 wherein the central opening
comprises a keyed shape allowing insertion of a lifting anchor
through the central portion in a first rotational orientation, and
engaging the lifting anchor to the lifting bracket when the lifting
anchor is rotated to a second rotational orientation.
15. The reinforcing bracket of claim 11 wherein the central portion
comprises a plurality of openings to receive the legs of a loop
lifting anchor.
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 reinforcing bracket for use with lifting anchors
embedded in reinforced concrete walls and other reinforced concrete
components.
[0003] 2. Prior Art
[0004] Reinforced concrete has been used for many years in building
construction. Reinforced concrete is typically cast by pouring
concrete into forms having a desired shape and containing
reinforcing members that become embedded in the concrete to
increase its tensile strength. Steel reinforcing bars (or rebar)
and steel cables are commonly used as reinforcing members, although
other reinforcing materials are also sometimes employed.
[0005] For some construction jobs, reinforced concrete components
are cast in place on the construction site. Larger concrete walls
and planar concrete components are usually cast in a horizontal
orientation, and then righted or lifted into position after the
concrete has set. Lifting anchors are often embedded in the edges
of the concrete to facilitate this operation.
[0006] Many reinforced concrete components are cast off-site and
then shipped to the construction site. In particular, many
construction projects require prestressed concrete components, in
which at least some of the reinforcing members are tensioned while
the concrete sets. This pre-tensioning is transferred to the
finished concrete component and further increases is tensile
properties. Prestressed concrete components are not usually
produced at the construction site, but rather are produced at a
central plant and then shipped to the construction site. Here
again, lifting anchors are commonly embedded in prestressed
concrete components to facilitate lifting and transportation.
[0007] The prior art includes a wide variety of lifting anchors for
use with concrete components. Burke-style lifting anchors have a
rectangular shaft with an eye at one end that remains exposed at
the edge of the concrete to receive a cable or hook for lifting.
Y-shaped legs at the opposing end of the shaft help to anchor the
device in the concrete. Another type of lifting anchor is made of a
U-shaped steel cable with its legs embedded in the concrete. The
curved loop of the U-shaped cable remains exposed at the edge of
the concrete for lifting purposes. Other types of lifting anchors
are also used in the industry. It should be understood that the
term "lifting anchor" should be broadly construed to encompass any
such device for lifting concrete components.
[0008] In many reinforced concrete components, the lifting anchors
are not mechanically tied into the reinforcing members embedded in
the concrete. This has the advantages of simplicity and low cost,
but significantly limits the ultimate strength of the assembly when
the concrete component is lifted.
[0009] To address this shortcoming, lifting anchors are sometimes
welded to the rebar. This may be acceptable if a skilled welder is
readily available at the job site and the number of welds required
is reasonably small. However, in many situations, welding can
become expensive and time-consuming.
[0010] In addition, the prior art includes a number of mechanical
devices for securing the lifting anchors to the reinforcing
members. For example, U.S. Pat. No. 4,087,947 (Turner) discloses a
twisted hanger clip that connects an anchor bolt to rebar embedded
in the concrete. The hanger clip 36 is perhaps most clearly shown
in FIG. 3 of the Turner patent. U.S. Patent Application Pub. No.
2004/0010984 (Wright) shows an anchoring device that has a lifting
pin, a cup-shaped void former, and orthogonal attachment arms with
slots for engaging rebar. U.S. Pat. No. 6,694,680 (Zambelli et al.)
shows a lifting insert having a tubular insert, and a brace made of
a steel strip with opposing wings that extend adjacent to the
rebar. U.S. Patent Application Pub. No. 2010/0037536 (Schulze)
discloses a lifting insert assembly for concrete panels that has a
cup-shaped cap, a triangular insert, and an X-shaped foot with
clips for engaging the rebar. However, the prior art devices in
this field have limitations in terms of cost, complexity, assembly
requirements, and/or load limitations. Therefore, a need continues
to exist for a reinforcing bracket for use with lifting anchors
that has the advantages of simplicity, low cost and ruggedness.
[0011] In particular, the present invention eliminates the need for
costly welding operations to connect lifting anchors to the
reinforcing members for the piece. The present invention is also
very quick and easy to assemble, and does not require the use of
tools for assembly. The present invention accommodates a variety of
lifting anchors, such as Burke-style lifting anchors and loop
lifting anchors. Finally, the present invention allows heavier
pieces to be lifted with greater confidence. Testing has shown the
present reinforcing bracket effectively distributes the weight of
the concrete component over a greater area. The present invention
increases the size of the resulting shear cone during lifting,
thereby decreasing the risk of failure during lifting and
increasing the safety of the side-lifting operation.
SUMMARY OF THE INVENTION
[0012] This invention provides a reinforcing bracket for use with a
lifting anchor embedded in a reinforced concrete wall. The
reinforcing bracket has a planar central portion extending parallel
to the reinforcing members with at least one central opening to
receive a lifting anchor. Two V-shaped wings extend out of the
plane of the central portion from the opposing ends of the central
portion. Sets of aligned openings pass through these wings to
receive reinforcing members.
[0013] 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
[0014] The present invention can be more readily understood in
conjunction with the accompanying drawings, in which:
[0015] FIG. 1 is a perspective view of the reinforcing bracket
20.
[0016] FIG. 2 is a front elevational view of the reinforcing
bracket 20.
[0017] FIG. 3 is a bottom plan view of the reinforcing bracket
20.
[0018] FIG. 4 is a rear elevational view of the reinforcing bracket
20.
[0019] FIG. 5 is a left side elevational view of the reinforcing
bracket 20.
[0020] FIG. 6 is a rear perspective view of the reinforcing bracket
20 assembled with reinforcing members 12, 14 and a Burke-style
lifting anchor 50.
[0021] FIG. 7 is a front perspective view showing the assembly in
FIG. 6.
[0022] FIG. 8 is a cross-sectional view of the assembly in FIG. 6
embedded in a concrete wall 10.
[0023] FIG. 9 is a rear perspective view of the reinforcing bracket
20 assembled with reinforcing members 12, 14 and a loop lifting
anchor 60.
[0024] FIG. 10 is a cross-sectional view of the assembly in FIG. 9
embedded in a concrete wall 10.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Turning to FIG. 1, a perspective view is provided of a
reinforcing bracket 20 embodying the present invention. A
corresponding front elevational view is shown in FIG. 2. FIG. 3 is
a bottom plan view. FIGS. 4 and 5 show rear and left side
elevational views of the reinforcing bracket 20, respectively. The
major components of the reinforcing bracket 20 include a
substantially planar central portion 26 with a generally
rectangular shape. This central portion 26 runs parallel to the
reinforcing members adjacent to the edge of the concrete component
after assembly. Its width is slightly less than the width of the
concrete component in which the reinforcing bracket 20 is to be
embedded, so that the reinforcing bracket 20 will be entirely
encased in concrete. The plane of the central portion 26 of the
reinforcing bracket 20 will also be generally parallel to the plane
of the edge of the concrete component.
[0026] Two wings 30, 31 and 40, 41 wings protrude out of the plane
of the central portion 26 from the opposing ends of the central
portion 26. In the embodiment of the present invention shown in the
accompanying drawings, these wings 30, 31 and 40, 41 have a
generally V-shaped cross-section. Alternatively, the wings could be
U-shaped or any of a variety of other configurations.
[0027] At each wing, a first wing portion 30, 40 continues from the
end of the central portion 26 and extends out of the plane of the
central portion 26. A second wing portion 31, 41 continues from the
first wing portion 30, 40 and returns toward the plane of the
central portion 26. Both the first wing portions 30, 40 and second
wing portions 31, 41 can be substantially planar and rectangular in
shape. In particular, the central portion 26 and wings 30, 31 and
40, 41 can be formed from a single flat, rectangular piece of steel
by conventional bending operations.
[0028] Reinforcing members are typically placed to run in a variety
of directions within concrete components. For example, reinforcing
members often form cages or frames within concrete components. Of
these, some segments of the reinforcing members run parallel to the
surface of the edge of the concrete component, but at a depth of a
few inches within the concrete.
[0029] A number of sets of aligned holes or openings 32-35 and
42-45 pass through the wings 30, 31 and 40, 41 to receive these
reinforcing members (e.g., rebar 12, 14). Assuming at least these
segments of the reinforcing members are straight, a first rebar 12
can be inserted through openings 33, 32, 42 and 43, and a second
rebar 14 can be inserted through openings 35, 34, 44 and 45 as
shown for example in FIGS. 6-9. Typically, these rebars 12, 14 run
parallel to the edge of the concrete component 10 at a depth of a
few inches below the surface of the concrete as shown in FIG. 8. In
other words, the rebars 12, 14, the central portion 26 of the
reinforcing bracket 20, and the edge of the concrete component 10
are all parallel to one another when assembled.
[0030] FIGS. 6-8 illustrate use of the reinforcing bracket 20 in
conjunction with a Burke-style lifting anchor 50. FIG. 6 is a rear
perspective view of the reinforcing bracket 20 assembled with
rebars 12, 14 and a Burke-style lifting anchor 50. FIG. 7 is a
corresponding front perspective view showing this assembly. A
Burke-style lifting anchor 50 commonly has Y-shaped legs 51, 52 at
its distal end and a lifting hole or eye 54 near the proximal end
of the shaft to receive a cable or hook for lifting the concrete
component 10. The proximal end of the shaft and the eye 54 are
remain exposed in a cup-shaped recess 16 at the edge of the
concrete component 10 as shown in FIG. 8. Many Burke-style lifting
anchors 50 also include a pair of side notches 53 in the edges of
the shaft.
[0031] The central portion 26 of the reinforcing bracket 20
includes a large central opening 21 to receive the shaft of the
Burke-style lifting anchor 50. Optionally, the central opening 21
can be key-shaped to allow insertion of the shaft of a lifting
anchor 50 through the central portion in a first rotational
orientation, but engage the lifting anchor 50 to the reinforcing
bracket 20 when the lifting anchor 50 is rotated to a second
rotational orientation. For example, the embodiment shown in the
accompanying drawings has a central opening 21 that is generally
oval in shape with vertical extensions 22, 23 for holding the
lifting anchor 50 in a vertical orientation.
[0032] The following is a description of the stops involved in used
the present invention. Lifting anchors are typically installed at
intervals along at least one edge of the concrete component 10 as
depicted in the cross-sectional view in FIG. 8. First, the
reinforcing bracket 20 is embedded into the internal reinforcing
cage or frame. A lifting anchor 50 is then attached to the
reinforcing bracket 20. The concrete is then poured and allowed to
cure. Once the concrete has cured and reached its release strength,
the form is removed from around the concrete component 10. Lifting
hooks are then snapped into each of the lifting anchors 50 embedded
along the sides of the piece 10. An overhead crane then lifts the
piece 10 out of the form. The concrete component 10 is then moved
to a tilt table where the piece is stood upright, or the piece 10
can be stood up in place.
[0033] Optionally, the present invention can be used in combination
with a loop lifting anchor, as illustrated in FIGS. 9 and 10. FIG.
9 is a rear perspective view of the reinforcing bracket 20
assembled with a loop lifting anchor 60. FIG. 10 is a
cross-sectional view of the assembly in FIG. 9 embedded in a
concrete wall 10. The loop lifting anchor 60 is generally U-shaped
with two legs 61, 62 that can be inserted through smaller openings
24, 25 in the central portion 26 of the reinforcing bracket 20.
[0034] 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.
* * * * *