U.S. patent application number 12/297557 was filed with the patent office on 2009-12-17 for anchor for use in joining concrete slabs.
Invention is credited to Bruce Ian Ireland, Daniel Charles Underwood.
Application Number | 20090308005 12/297557 |
Document ID | / |
Family ID | 38608980 |
Filed Date | 2009-12-17 |
United States Patent
Application |
20090308005 |
Kind Code |
A1 |
Ireland; Bruce Ian ; et
al. |
December 17, 2009 |
ANCHOR FOR USE IN JOINING CONCRETE SLABS
Abstract
A headed loop anchor (10) comprising a "U" shaped section having
parallel spaced legs (11 and 12) and a looped adjoining section
(13), the free ends (14 and 15) having heads (16 and 17). The
headed loop anchor is formed by bending and then forging the head
from the legs so the anchor is an integral unit. In use, the headed
loop anchors are positioned in parallel spaced relation so that the
looped sections (13) project from a slab so that a suitable
connector may be used to hook over the loop sections (13) in order
to connect adjacent concrete sections together.
Inventors: |
Ireland; Bruce Ian;
(Munrobon, AU) ; Underwood; Daniel Charles;
(Queensland, AU) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
1290 Avenue of the Americas
NEW YORK
NY
10104-3800
US
|
Family ID: |
38608980 |
Appl. No.: |
12/297557 |
Filed: |
April 19, 2007 |
PCT Filed: |
April 19, 2007 |
PCT NO: |
PCT/AU2007/000506 |
371 Date: |
April 28, 2009 |
Current U.S.
Class: |
52/250 ; 52/698;
52/745.21 |
Current CPC
Class: |
E04B 1/41 20130101; E04B
1/046 20130101 |
Class at
Publication: |
52/250 ; 52/698;
52/745.21 |
International
Class: |
E04C 5/12 20060101
E04C005/12; E04G 21/00 20060101 E04G021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2006 |
AU |
2006902018 |
Claims
1. A headed loop anchor (10) when used in concrete for connection
to reinforcing bars in an adjacent concrete slab to be poured
afterwards, the headed loop anchor comprising a "U" shaped anchor
having parallel spaced legs (11,12) each having respective free
ends (14,15) and a loop section (13) bridging between the parallel
spaced legs, each free end of the legs having a head (16,17), the
headed loop anchor being locatable in a concrete slab with the loop
section projecting from the slab and being adapted for connection
to reinforcing bars in an adjacent slab to be poured
afterwards.
2. A headed loop anchor according to claim 1 wherein the loop
section is a circular section of bar.
3. A headed loop anchor according to claim 1 wherein the headed
loop anchor is formed as an integral unit having heads formed from
the loop anchor material in a hot forging process.
4. A headed loop anchor according to claim 1 wherein the loop
anchor material is at least 600 grade wire.
5. A headed loop anchor according to claim 1 wherein the loop
anchor is formed from a hard drawn wire of at least 600 grade high
tensile wire.
6. A partially completed concrete construction comprising a
concrete slab employing spaced apart headed loop anchors, each
headed loop anchor comprising a "U" shaped anchor having parallel
spaced legs (11,12) each having respective free ends (14,15) and a
loop section (13) bridging between the parallel spaced legs, each
free end of the legs having a head (16,17), the headed loop anchors
being located in the concrete slab with the loop section projecting
from the slab and being adapted for connection to reinforcing bars
in an adjacent slab to be poured afterwards.
7. A partially completed concrete construction according to claim 6
wherein the headed loop anchors have their heads set at 120 mm to
170 mm deep into the slab.
8. A partially completed concrete construction according to claim 6
wherein the headed loop anchors project from a rebate in the
slab.
9. A partially completed concrete construction according to claim 6
wherein the headed loop anchors project from a rebate in the slab
and each loop has a connector coupled thereto and connecting
reinforcing to the respective loop sections.
10. A partially completed concrete construction according to claim
6 wherein the headed loop anchors project from a rebate in the slab
and each loop has a connector coupled thereto and connecting
reinforcing to the respective loop sections and the connectors
having D-shaped lands matched to the loops and fitting inside the
loops.
11. A partially completed concrete construction according to claim
6 wherein a connector used to connect the headed loop anchors to
reinforcing in an adjacent concrete slab, the connector comprising
a unit having a loop attachment means at one side to attach the
connector to a loop section of the headed loop anchor and a
reinforcement attachment means at the other side to attach the
connector to the reinforcing in the adjacent concrete slab.
12. A method of connecting two adjacent concrete slabs together
using headed loop anchors (10) comprising the steps of first
setting reinforcement for a first one of the two slabs (19,21) and
then placing the legs (11,12) of plural headed loop anchors amongst
the reinforcing with the loop section (13) positioned to project
from the first slab (19) when poured, pouring the first slab,
allowing it to cure sufficiently to begin preparation to pour the
second slab, tie the headed loop anchors to reinforcing steel in
the second slab and subsequently pour the second slab.
13. The method according to claim 12 wherein the headed loop
anchors comprise headed loops anchors comprising a "U" shaped
anchor having parallel spaced legs (11,12) each having respective
free ends (14,15) and a loop section (13) bridging between the
parallel spaced legs, each free end of the legs having a head
(16,17).
14. The method according to claim 12 the headed loop anchors have a
loop section comprising a circular section of bar.
15. The method according to claim 12 wherein a connector used to
connect the headed loop anchors to reinforcing in an adjacent
concrete slab.
16. canceled
17. canceled
18. canceled
Description
FIELD OF THE INVENTION
[0001] THIS INVENTION relates to an anchor when used in concrete
building construction and in particular but not limited to a "U"
shaped looped anchor utilised in relation to a concrete floor
employing concrete connectors connecting the loop anchor to
reinforcing structures in the adjacent floor where the loop is
utilised in a rebate in a wall or the like.
BACKGROUND OF THE INVENTION
[0002] It is common to construct walls with rebates and for tie
reinforcing to project from the rebate which is tied into a floor
with the edge of the floor poured into the rebate. The most common
arrangement utilises a rebate box having a cover and fitted into
wall form work in horizontal position. The wall is poured and the
cover is removed from the rebate box to reveal the reinforcing tie
bars held in the rebate box. These bars are usually pre-bent into
the box at the factory and then bent out to project from the
rebate. These bars are tied into the reinforcing of the floor as
the floor is being prepared for pouring and the concrete floor is
poured, thus tying the reinforcing of the floor into the wall.
[0003] Recent alternatives to this arrangement include rebate
forming arrangements which do not use the bend out bar arrangement
but, rather, when the cover is removed from the rebate box, loops
project from the rebate and bars from the floor are simply
connected to the loops using connectors.
[0004] The loops are anchored in the reinforcing of the wall using
various arrangements of bends to the bars forming the loops. In one
configuration known as "paper clip" the loop sections are part of a
paper clip type formation.
[0005] These are formed from deformed reinforcing bar by
manipulating the bar to one and a half loops. The overlap bar at
one end of the loop forms the anchorage device into the wall while
the other end is a single "U" shaped configuration which ultimately
projects into the rebate for connection to the floor reinforcement
via the connector. This type of anchor is difficult to manufacture,
and because it is a closed loop, it is also difficult to install
between the reinforcing cage bars in the wall prior to pouring the
concrete for the wall.
[0006] Connecting and tying reinforcement in concrete to join
panels is a crowded art where many and varied techniques and
apparatus are used including loop arrangements. U.S. Pat. No.
4,324,508 to Hilfiker et al discloses use of spaced U-shaped looped
bars having turned legs and a connecting web portion, the web
portions project from a wall or floor with a gap between the web
portion and the wall or floor. The gap is used to tie the loops to
the steel in the adjacent sections. In order to retain the looped
bars in position the turned legs are pre-welded to a bar or bars
running at 90.degree. to the loops and interconnecting adjacent
loops in parallel spaced relation.
[0007] U-shaped arrangements are used for other purposes including
provision of lifting anchors. U.S. Pat. No. 6,082,700 to Lancelot,
III et al describes a U-shaped anchor having legs and retaining
members at the ends of the legs, the retaining members being of
larger cross-section that the respective legs for facilitating
engagement and retention of the anchor within the concrete
structure. The anchor has its apex within a recess made using a
removable void former. The anchor is used in conjunction with a
hoist or crane so that the concrete may be lifted into
position.
[0008] While the basic U-shaped device is well known and has been
well known for many years, including the simple U-bolt, the present
invention relates to a novel and simple application to the process
of tying steel into adjacent slabs.
[0009] It is an object of the present invention to provide an
alternative anchor which at least provides the public with a useful
alternative but overcomes the problems associated with the paper
clip type arrangement referred to above.
OUTLINE OF THE INVENTION
[0010] In one broad aspect the invention resides in the use of a
headed loop anchor to aid the tying together of adjacent concrete
slabs. Preferably the headed loop anchor is U-shaped.
[0011] In one preferred aspect therefore the present invention
resides in a headed loop anchor comprising a "U" shaped anchor
having parallel spaced anchorage sections each having respective
free ends and a loop section bridging between the parallel spaced
legs, each free end of the legs having a head, the headed loop
anchor being locatable in a concrete slab with the loop section
projecting from the slab and being adapted for connection to
reinforcing bars in an adjacent slab to be poured afterwards.
[0012] Typically, the dimensions and arrangements, length of the
legs, size and configuration of the heads being such that the
headed loop anchor may be simply inserted through cage reinforcing
prepared in a concrete-slab and placed in position according to
normal procedures.
[0013] Preferably, the headed loop anchor is formed as an integral
unit having heads formed from the loop anchor material in a hot
forging process.
[0014] Preferably, the loop anchor material is at least 600 grade
wire. More preferably, the loop anchor is formed from a hard drawn
wire of at least 600 grade wire with 670 grade high tensile wire
being preferred.
[0015] In another aspect the invention resides in a partially
completed concrete construction employing spaced apart headed loop
anchors as described above with the looped section of the headed
loop anchor projecting from the partially completed concrete
construction.
[0016] Preferably, the headed loop anchors have their heads set at
120 mm to 170 mm deep. This will naturally depend on the strength
of the concrete. The typical arrangement is to configure the headed
loop anchors in terms of the dimensions thereof and the strength of
the concrete such that in a test rig the concrete fails before the
headed loop anchor.
[0017] In a further aspect the invention provides a rebate form
work comprising a box holding headed loop anchors as described
above in spaced apart relation, the box having a back wall through
which loops project into the box and legs project out of the box
and a there being a removable cover witch closes the box and may be
removed to expose the loops inside the box.
[0018] It will be appreciated that in the preferred form of the
invention the headed loop anchors have their respective heads free
and not welded to steel in the concrete, although some limited
tying may be used.
[0019] In a still further aspect there is provided in combination a
headed loop anchor as described above and a connector used to
connect the headed loop anchor to reinforcing in an adjacent
concrete slab, the connector comprising a unit having a loop
attachment means at one side and a reinforcement attachment means
at the other side.
[0020] In one further aspect there is provided a method of
connecting two adjacent concrete slabs together using headed loop
connectors comprising the steps of first setting the reinforcement
in a first one of the two slabs and then placing the legs of plural
headed loop anchors amongst the reinforcing with the loop section
positioned to project from the first slab when poured, pouring the
first slab, allowing it to cure sufficiently to begin preparation
to pour the second slab, tie the headed loop anchors to reinforcing
steel in the second slab and subsequently pour the second slab.
Preferably, the method employs headed loop anchors as described
above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order that the present invention may be more readily
understood and be put into practical effect, reference will now be
made to the accompanying drawings which illustrate preferred
embodiments of the invention and wherein:
[0022] FIGS. 1 and 2 are respective plan and perspective views of a
typical headed loop anchor;
[0023] FIG. 3 is a plan view showing four headed loop anchors in
alignment as they would appear in operative position relative to a
slab join (other reinforcement and slab not shown);
[0024] FIG. 4 is a schematic drawing showing a partially completed
concrete construction utilising headed loop anchors according to
the present invention in a wall rebate; and
[0025] FIG. 5 is a schematic drawing showing a partially completed
concrete construction utilising headed loop anchors according to
the present invention in a wall rebate with connectors used to tie
the loops to steel in the adjacent floor.
DETAILED DESCRIPTION OF THE DRAWINGS
[0026] Referring to the drawings and initially to FIG. 1 and FIG.
2, there is illustrated a headed loop anchor 10 comprising a "U"
shaped section having parallel spaced legs 11 and 12 and a looped
adjoining section 13, the free ends 14 and 15 having heads 16 and
17. The headed loop anchor is formed by bending and then forging
the head from the legs so the anchor is an integral unit.
[0027] In the illustrated embodiment the bar diameter is 13.6 mm
and the loop section has an internal diameter of 48 mm. The leg
spacing is also 48 mm. The head thickness is 7.3 mm at its thickest
and each head is 35 mm in diameter. The area of each head is
typically 4-5 times the area of the bar cross-section.
[0028] In use, the headed loop anchors are positioned as
illustrated in FIG. 3 in parallel spaced relation so that the
looped sections 13 project from a slab so that a suitable connector
(not shown) may be used to hook over the loop sections 13 in order
to connect adjacent concrete sections together.
[0029] The legs 11 project into and are retained in a previously
poured slab and are suitably tied in to the reinforcement of that
slab for alignment purposes.
[0030] FIG. 4 illustrates a partially completed concrete
construction 18 comprising, in this case, a wall 19 having a rebate
20 formed in the wall by a previously removed rebate form work
involving headed loop anchors according to the present invention.
The removal of the cover exposes projecting loop sections 13 of
headed loop anchors 10, the headed sections and leg sections being
secured in the concrete wall section 19.
[0031] It will thus be appreciated that a floor illustrated by the
dotted lines 21 may be secured and poured into the rebate 20 and
the reinforcing of the floor connected to the loops 13.
[0032] FIG. 5 shows an examples of various connectors that may be
used including a simple hook 21 with a rebar 22 secured into a
threaded opening in the hook 21. Another arrangement may be a two
part connector 24 having a bottom 25 and a top (not shown), the
bottom having D-spaded lands 26 and 27 matched to loops so that a
loop 28 may be connected to the loops anchors 10.
[0033] Whilst the above has been given by way of illustrative
example of the present invention many variations and modifications
thereto will be apparent to those skilled in the art without
departing from the broad ambit and scope of the invention as set
out in the appended claims.
* * * * *