U.S. patent application number 11/026909 was filed with the patent office on 2006-07-13 for anchoring system.
This patent application is currently assigned to Okabe Co., Inc.. Invention is credited to Peter L. Bakos.
Application Number | 20060150566 11/026909 |
Document ID | / |
Family ID | 36651810 |
Filed Date | 2006-07-13 |
United States Patent
Application |
20060150566 |
Kind Code |
A1 |
Bakos; Peter L. |
July 13, 2006 |
Anchoring system
Abstract
An anchoring device having a length of reinforcing material, a
shell section attached to the reinforcing material, wherein the
shell section has a hollow inner core, and a wedge located at least
partially in the inner core of said shell section. In one
embodiment, the wedge section is integral with the reinforcing
material. In a preferred embodiment, the shell section has four
segments and the wedge and the shell section have circumferential
barbs on an outer portion thereof to provide greater retention
properties for the anchoring system. One embodiment of the present
invention also includes a method of attaching a reinforcing
structure having a first end, a second end, and a longitudinal axis
to an existing substrate, the method including the steps of
drilling an aperture in the substrate, inserting the first end of
the reinforcing structure in the aperture, the first end containing
a shell portion attached thereto, the shell portion having a hollow
inner core, the shell portion further containing a wedge partially
inserted in the hollow inner core. The method further includes, in
one embodiment of the invention, hammering the second end of the
reinforcing structure in a direction parallel to the longitudinal
axis and toward the aperture, wherein the hammering causes the
wedge to be driven into the hollow inner core, thereby causing the
end of the shell portion to flare outward and against the walls of
the aperture.
Inventors: |
Bakos; Peter L.;
(Barrington, IL) |
Correspondence
Address: |
Douglas M. Eveleigh;Mayer, Brown, Rowe & Maw LLP
P.O. Box 2828
Chicago
IL
60690-2828
US
|
Assignee: |
Okabe Co., Inc.
|
Family ID: |
36651810 |
Appl. No.: |
11/026909 |
Filed: |
December 29, 2004 |
Current U.S.
Class: |
52/718.02 |
Current CPC
Class: |
E04C 5/161 20130101 |
Class at
Publication: |
052/718.02 |
International
Class: |
E04C 2/38 20060101
E04C002/38 |
Claims
1. An anchoring device comprising: a length of reinforcing
material; a shell section attached to said reinforcing material,
wherein said shell section has a hollow inner core and is segmented
on one end thereof; a wedge located at least partially in the inner
core of said shell section.
2. The anchoring device of claim 1, wherein said reinforcing
material is rebar.
3. The anchoring device of claim 1, wherein said reinforcing
material is threaded rod;
4. The anchoring device of claim 1, wherein said shell section has
four segments.
5. The anchoring device of claim 1, wherein said shell section
contains barbs on an outside portion thereof.
6. The anchoring device of claim 5, wherein said barbs are
circumferential.
7. The anchoring device of claim 1, wherein said wedge us
frusto-conical in shape.
8. The anchoring device of claim 1, wherein said wedge contains
barbs on an outside portion thereof.
9. The anchoring device of claim 8, wherein said barbs are
circumferential.
10. The anchoring device of claim 8, wherein said inner core of
said shell section contains locking detents, wherein said locking
detents are designed to engage said barbs on said wedge to prevent
said wedge from being removed from said inner core.
11. The anchoring device of claim 1, wherein said shell portion is
attached to said reinforcing structure by a crimp connection.
12. A method of attaching a reinforcing structure having a first
end, a second end, and a longitudinal axis to an existing
substrate, said method comprising: drilling an aperture in said
substrate; inserting said first end of said reinforcing structure
in said aperture, said first end containing a shell portion
attached thereto, said shell portion having a hollow inner core and
being segmented on one end thereof, said shell portion further
containing a wedge partially inserted in said hollow inner core;
hammering said second end of said substrate in a direction parallel
to said longitudinal axis and toward said aperture, wherein said
hammering causes said wedge to be driven into said hollow inner
core, thereby causing the segmented end of said shell portion to
flare outward and against the walls of said aperture.
13. The method of claim 12, wherein said reinforcing structure is
rebar.
14. The method of claim 12, wherein said reinforcing structure is
threaded rod.
15. The method of claim 12, wherein said shell portion has four
segments on said one end thereof.
16. The method of claim 12, wherein said shell portion has
circumferential barbs on an outer portion thereof.
17. The method of claim 12, wherein said wedge has circumferential
barbs on an outer portion thereof.
18. An anchoring device comprising: a length of reinforcing
material; a shell section attached to said reinforcing material,
wherein said shell section has a hollow inner core; and a wedge
proximate one end of said reinforcing material.
19. The anchoring device of claim 18, wherein said shell section is
segmented and wherein said shell section is slidably attached to
said reinforcing material.
20. The anchoring device of claim 18, wherein said wedge is
integral with said reinforcing material
Description
FIELD OF INVENTION
[0001] This invention relates generally to reinforcement bar
("rebar") and other types of reinforcing structures used in
concrete or other masonry structures, and in particular structures
and methods used to attached such reinforcing structures to
existing concrete and masonry.
BACKGROUND OF INVENTION
[0002] Rebar, thread rods and other types of reinforcing structures
are well known in the concrete/masonry fields, which are used to
reinforce concrete and masonry. For instance, with respect to
concrete, it is typical to lay a matrix of rebar in an area that
will be filled with concrete. When the concrete is poured into the
matrix of rebar, the rebar and cured concrete form a structure that
performs well in the presence of both tensile and compressive
loads. However, it is sometimes desired to attach rebar to an
existing cured concrete structure for the purposes of allowing
poured concrete in the next constructional stage of a structural
design to form an integral unit with the pre-existing, cured
concrete. In such a scenario, a portion of a length of rebar is
attached to the cured concrete and the rest of the length of rebar
is left exposed so that it can be engulfed by uncured concrete in
the next constructional stage. Alternatively, at times, it is
necessary to attach rebar to an existing, cured, concrete structure
for purposes of repair.
[0003] At present, a widely used method of attaching rebar (and
other reinforcing structures, such as thread rod) to existing cured
concrete or masonry structures utilizes an epoxy anchoring system.
Under such a method, a hole of the appropriate size and depth for
the rebar (or threaded rod) is drilled into the cured concrete
and/or masonry structure. The hole is then cleaned out and a
predetermined volume of mixed epoxy is placed in the hole. Next,
the rebar is inserted into the hole and the epoxy is allowed to
cure before the new concrete is poured.
[0004] While such epoxy anchoring methods can produce the
joint/bond strengths required for design requirements, these
methods have several shortcomings. First, they are time consuming
because of the time needed to mix and dispense the epoxy. Moreover,
even if the epoxy is pre-mixed, such pre-mixed epoxy has a limited
shelf life and must be stored under the proper conditions or else
the epoxy will be spoiled. Second, the metering and dispensing of
epoxy can be problematic. Indeed, in floor applications, overflow
and waste of the epoxy can occur if too much epoxy is placed into
the hole. Conversely, if too little epoxy is used, the rebar will
not attain the desired structural bond to the existing concrete.
Moreover, in wall and overhead applications, special dispensing and
retention products are required in order to try and keep the proper
volume of epoxy in the hole while the rebar is inserted and while
the epoxy is curing. Oftentimes, epoxy in these wall and overhead
applications will run out of the hole, thus causing waste and
clean-up problems for the construction site and the installer.
Third, the quality and cure times of an epoxy depends on many
variables, including ambient temperature, ambient humidity,
substrate temperature and substrate moisture content. Due to these
variables, an epoxy must be customized for each particular job so
that it is usable under the prevailing conditions. Moreover,
because of the cure times involved with epoxy, construction delays
can ensue, giving rise to increased construction costs. Lastly,
because epoxies are made of materials that may be hazardous,
special safety equipment and procedures must be employed when using
an epoxy.
[0005] Accordingly, there is a need for an alternative rebar,
thread rod (or other reinforcing structure) anchoring system that
addresses the above-identified issues
[0006] These and other needs will become more apparent upon a
review of the specification, drawings and claims, set forth
below.
SUMMARY OF THE INVENTION
[0007] One embodiment of the invention comprises an anchoring
device having a length of reinforcing material, a shell section
attached to the reinforcing material, wherein the shell section has
a hollow inner core, and a wedge located at least partially in the
inner core of said shell section. In one embodiment, the wedge
section is integral with the reinforcing material. In a preferred
embodiment, the shell section has four segments and the wedge and
the shell section have circumferential barbs on an outer portion
thereof to provide greater retention properties for the anchoring
system. One embodiment of the present invention also includes a
method of attaching a reinforcing structure having a first end, a
second end, and a longitudinal axis to an existing substrate, the
method including the steps of drilling an aperture in the
substrate, inserting the first end of the reinforcing structure in
the aperture, the first end containing a shell portion attached
thereto, the shell portion having a hollow inner core, the shell
portion further containing a wedge partially inserted in the hollow
inner core. The method further includes, in one embodiment of the
invention, hammering the second end of the reinforcing structure in
a direction parallel to the longitudinal axis and toward the
aperture, wherein the hammering causes the wedge to be driven into
the hollow inner core, thereby causing the end of the shell portion
to flare outward and against the walls of the aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side elevational view of an anchoring system of
one embodiment of the present invention.
[0009] FIG. 2 is a top plan view thereof;
[0010] FIG. 3 is a cross-sectional view showing an anchoring system
of one embodiment of the present invention installed in a
substrate;
[0011] FIG. 4 is a cross-sectional view showing an anchoring system
of one embodiment of the present invention installed in a
substrate;
[0012] FIG. 5 is a partial cross-sectional view showing a barbed
wedge inside of a shell portion of one embodiment of the present
invention;
[0013] FIG. 6 is a side elevational view of a wedge in one
embodiment of the present invention;
[0014] FIG. 7 is a cross-sectional view of a portion of a shell
section of one embodiment of the present invention;
[0015] FIG. 8 is a partial cross sectional view of a portion of a
shell section of one embodiment of the present invention joined to
a piece of reinforcing material; and
[0016] FIG. 9 is another embodiment of the anchoring system of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] While the present invention is capable of embodiment in
various forms, there is shown in the drawings and will be
hereinafter described a presently preferred embodiment with the
understanding that the present disclosure is to be considered as an
exemplification of the invention, and is not intended to limit the
invention to the specific embodiment illustrated.
[0018] With reference to FIG. 1, one embodiment of the anchoring
system 10 of the present invention includes a length of rebar 12, a
shell section 14 and a wedge 16. It will be appreciated that
although a length of rebar 12 is shown and described in one
embodiment of the present invention, any other type of reinforcing
structure used with concrete or masonry structures, such as, for
instance, threaded rod, can be used in the practice of the present
invention.
[0019] In one embodiment of the invention, the shell section 14 has
a hollow inner core and is segmented into four grippers 18 at one
end thereof. It will be appreciated, however that more or less
gripper segments can be used in the practice of the present
invention. For instance it is possible that just two gripper
segments can be used in the practice of the present invention.
Moreover, it is possible that, using proper materials that would
allow for proper installation, the shell section need not be
segmented at all. As shown in FIGS. 3 and 4, these grippers 18 are
driven outward when wedge 16 is driven toward the rebar 12 during
an installation process, which is described in more detail
below.
[0020] In a preferred embodiment, the sizes of dimensions A, B, C
and D, shown in FIG. 1, for rebar size numbers 3, 4 and 5 are shown
below in Table I: TABLE-US-00001 TABLE I Dimension Dimension
Dimension Dimension "A" "B" "C" "D" Rebar Size (mm) (mm) (mm) (mm)
#3 450 40 18 14 #4 600 50 22.9 17.5 #5 750 60 30 21.7
[0021] In one embodiment of the present invention, the wedge 16 is
frusto-conical in shape and may contain circumferential locking
barbs 20, which act to lock the wedge 16 in place after being
driven toward rebar 12. Preferably, there are four such
circumferential barbs 20 in a 10 degree by 15 degree profile, as
shown in FIG. 6. In one embodiment, the barbs 20 may engage detents
22 on shell section 14 for increased locking forces between the
wedge 16 and the shell section 14. Moreover, for better locking
forces between the grippers 18 and the concrete or masonry (shown
in FIGS. 3 and 4 as reference numeral 24), the grippers 18 may also
contain circumferential barbs 26 on the outer diameter thereof. In
a preferred embodiment, there are four such barbs 26, which have a
ledge portion 28 that is approximately 0.010 inches wide, is at an
approximately 5 degree angle, as shown in FIG. 5, and has an angled
portion 30 that is at an 100 degree angle to the horizontal.
Detents 22 are also preferably angled at 10 degrees from
horizontal, as shown in FIG. 7. Those with skill in the art will
recognize that other angles and dimensions than those specifically
discussed herein for the barb structures on the shell section 14
and the wedge 16 are within the scope of the present invention.
Moreover, although four circumferential barbs are used on the wedge
16 and the grippers 18 in a preferred embodiment, it will be
appreciated that more or less barbs may be used in the practice of
the present invention.
[0022] While some embodiments of the present invention use
circumferential barbs on the wedge 16 and shell section 14, it
should be noted that the present invention is not limited to
structures that use such barbs. Indeed, as shown in FIGS. 3 and 4,
the wedge 16 and the shell section 14 in these figures do not
include barbs. It is envisioned that such structures not containing
the barbs can be used in less-stringent load requirement
applications. Moreover, as shown in FIGS. 3 and 4, the wedge 16 may
be tapered throughout, as shown in FIG. 4 or may have tapered and
non tapered section, 16a and 16b, respectively. It is believed that
a wedge having a continuous taper will provide enhanced locking
forces.
[0023] Preferably, the shell section 14 and the wedge 16 are made
of a high quality, low carbon steel, such as SAE/AISI 1010 that is
heat treated to allow micro compression during installation and at
the same time retain its mechanical properties. Those with skill in
the art will appreciate, however, that other types of steels or
other materials can be used in the practice of the present
invention. In a preferred embodiment, the steel of shell section 14
and wedge 16 is heat treated by carbonnitriding at 1450-1650
degrees Fahrenheit using a cooling medium of oil and tempering at
250-400 degrees Fahrenheit The shell section 14 and the wedge 16
are also preferably zinc plated using a dichromate wash, which
helps the shell section 14 and the wedge 16 resist oxidation due to
the corrosive nature of concrete.
[0024] In order to attach the shell section 14 to the rebar 12, it
is preferred to utilize a macro-controlled swaging process, which
results in a reduced diameter portion 34 on the swaged section of
shell section 14, as shown in FIG. 1 As is known in the art, such a
swaging operation uses a hydraulic press and a set of specially
designed closed dies, which are controlled by a computer to ensure
consistent and uniform shell material formation around the outer
diameter of the rebar 12. As is shown in FIG. 8, the swaging
operation presses the shell material into the recesses of the
rebar, thus "locking" the two pieces together. The resultant
connection between the rebar and the shell section using such a
swaging operation has been found to be stronger than the bond
requirements between rebar and concrete. Alternatively, the shell
section 14 can be attached to the rebar 12 via welding, epoxy or
any other attachment scheme that will provide sufficient retention
forces to prevent the rebar 12 from separating from the shell
section 14 under load conditions. Also, in the case of a threaded
rod, the shell section 14 can contain internal threads that are
designed to mate with the threads on the threaded rod, and the two
pieces are connected by threading the threaded rod into the shell
section and tightening the same.
[0025] A method of installing the anchoring system of one
embodiment of the present invention will now be described. First, a
hole is drilled in the concrete or masonry structure to the
particular diameter and depth of the specific rebar and/or threaded
rod to be used. After all debris is removed from the hole, the
anchoring system 10 is loaded into the hole, rebar side up. Next,
the exposed end of the rebar is struck with a hammer, and
preferably a three-pound hammer, until the shell section 14 bottoms
out at the bottom of the drilled hole, as shown in FIGS. 3 and 4.
As those with skill in the art will appreciate, as the rebar is
hammered, the wedge 16 is driven into the hollow inner core of the
shell section 16 and, due to the shape of the wedge, the grippers
18 are driven outward so as to contact the cement or masonry and
provide a retaining force. It has been found that in order to
ensure that the anchor is completely set, the rebar, in one
embodiment of the invention, must be driven downward at least 3/8
of an inch. After an installer has some installation experience, he
or she will be able to determine a proper anchor setting by the
solid ring sound that is produced when the shell portion 14 bottoms
out in the hole.
[0026] It should be noted that while in one embodiment of the
invention, the wedge 16 is not integral with the rebar 12, it is
possible for the wedge and rebar to form an integral piece. Indeed,
as shown in FIG. 9, the rebar 12 and the wedge 16 are integral. In
such an embodiment, the shell 14 would preferably be slidably
attached to the rebar 12, and during installation, an installer
will, after drilling the appropriately-sized hole, place the wedge
portion 16 of the rebar 12 at the bottom of the hole and drive the
shell portion 14 toward the wedge portion 16 in the direction of
the arrow shown in FIG. 9, using an appropriate tool, for instance
a hollow cylindrical pipe 32 that sides over the rebar and contacts
the end portion 34 of the shell portion 14. As can be appreciated,
once the shell 14 is driven into wedge portion 16, the shell will
expand to lock the rebar 12 in place in the hole. Also, it is
envisioned that the frictional forces and some deformation of the
shell 14 will lock the shell 14 to the rebar 12 upon the shell
being fully driven into the wedge portion 16. It is also envisioned
that a preferred method of installation will involve the pipe tool
32 being of such a length that after the pipe tool 32 has driven
the shell portion 14 down a desired distance, the top of the pipe
tool 32 will be flush with the exposed portion of rebar 12, thus
providing an installer with a visual indication that the anchoring
system has been properly installed.
[0027] The foregoing description of a preferred embodiment of the
invention has been presented for purposes of illustration and
description, and is not intended to be exhaustive or to limit the
invention to the precise form disclosed. The description was
selected to best explain the principles of the invention and their
practical application to enable others skilled in the art to best
utilize the invention in various embodiments and various
modifications as are suited to the particular use contemplated. It
is intended that the scope of the invention not be limited by the
specification, but be defined by the claims set forth below.
* * * * *