U.S. patent application number 13/511647 was filed with the patent office on 2012-12-06 for collar for a concrete lifting anchor.
This patent application is currently assigned to CASNE VERIGE PTY LTD. Invention is credited to Robert Sladojevic.
Application Number | 20120304554 13/511647 |
Document ID | / |
Family ID | 42232808 |
Filed Date | 2012-12-06 |
United States Patent
Application |
20120304554 |
Kind Code |
A1 |
Sladojevic; Robert |
December 6, 2012 |
COLLAR FOR A CONCRETE LIFTING ANCHOR
Abstract
A collar for a concrete component lifting anchor including an
attachment portion for attaching the collar to the lifting anchor,
and an abutment portion adapted to provide a clutch abutment
surface for limiting rotation of a clutch relative to the lifting
anchor.
Inventors: |
Sladojevic; Robert; (Cherry
Gardens, AU) |
Assignee: |
CASNE VERIGE PTY LTD
Terrace Kent Town ,South Australia
AU
|
Family ID: |
42232808 |
Appl. No.: |
13/511647 |
Filed: |
November 25, 2009 |
PCT Filed: |
November 25, 2009 |
PCT NO: |
PCT/AU2009/001541 |
371 Date: |
May 23, 2012 |
Current U.S.
Class: |
52/125.4 |
Current CPC
Class: |
B66C 1/666 20130101;
E04G 21/142 20130101 |
Class at
Publication: |
52/125.4 |
International
Class: |
E04G 21/14 20060101
E04G021/14 |
Claims
1. A collar for an anchor for use in lifting a concrete component,
said anchor comprising a head portion engageable with a clutch of a
lifting system, and a body portion for embedment within the
concrete component, the collar including an attachment portion for
attaching the collar to the head portion of the anchor, and an
abutment portion adapted to provide a clutch abutment surface for
limiting rotation of the clutch relative to the anchor.
2. A collar as claimed in claim 1, wherein when the collar is
fitted to the anchor the abutment portion forms the clutch abutment
surface as a shoulder adjacent the anchor.
3. A collar as claimed in claim 2, wherein the clutch abutment
surface is formed as a shoulder standing proud of the head portion
for limiting rotation of the clutch about an eye of the head
portion.
4. A collar as claimed in claim 3, wherein the abutment portion
provides a pair of opposed shoulders on the head portion for
limiting rotation of the clutch about the eye in both directions of
rotation.
5. A collar as claimed in claim 4, including a gap between the
shoulders which coincides with the eye of the head portion to allow
passage of the clutch through the eye.
6. A collar as claimed in claim 5, wherein the abutment portion is
formed by an edge of the collar.
7. A collar as claimed in claim 1, wherein the collar fits around
the head portion, and is held to the head portion by way of a press
fit.
8. A collar as claimed in claim 1, wherein the collar is generally
C-shaped.
9. A collar as claimed in claim 1, including at least one shear bar
attached to the collar.
10. A collar as claimed in claim 9, wherein the shear bar engages
in a groove of the collar.
11. A collar as claimed in claim 9, wherein the shear bar is welded
to the collar.
12. A collar as claimed in claim 9, wherein the shear bar is formed
in a generally wave-like shape, with oscillations in a direction
generally perpendicular to a central axis of the anchor when the
collar is fitted to the anchor.
13. A collar as claimed in claim 12, including a second shear bar,
wherein a major axis of the second shear bar is generally parallel
to a major axis of the first shear bar and is substantially a
mirror image of the first shear bar when viewed from an end of the
anchor.
14. An anchor for use in lifting a concrete component, said anchor
comprising a single length of wire bent to form a head portion
engagable with a clutch of a lifting system, and a body portion for
embedment within the concrete component, wherein the anchor has a
collar attached to the head portion to provide clutch abutment
surfaces for limiting rotation of the clutch relative to the
anchor, the collar being a collar as claimed in claim 1.
15. An anchor system for use in lifting a concrete component, the
assembly comprising an anchor formed from a one-piece elongate
element shaped to form a head portion engageable by a clutch of a
lifting system and a body portion for embedment within the concrete
component; and a collar carried by the head portion of the anchor
to define at least one clutch abutment surface for limiting
rotation of the clutch relative to the anchor.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a collar for a concrete panel
lifting anchor and, more particularly but not exclusively, to a
concrete panel lifting anchor formed of bent wire having a collar
to provide clutch abutment surfaces.
BACKGROUND OF THE INVENTION
[0002] It is known to lift a concrete panel by way of an anchor
embedded within the concrete panel during casting of same. A
typical anchor of this kind is formed from metal by cutting the
anchor from a plate, and is cut so as to provide clutch abutment
shoulders to limit rotation of a lifting clutch relative to the
anchor. However, the applicant has identified that such typical
anchors are relatively expensive to produce due to the cutting
procedure, and that use of such typical anchors may be restrictive
as the anchor must be located at or near a central plane of the
panel. Lifting anchors fabricated by cutting plate material require
a lot of energy to produce, and often have irregularities.
Disadvantages also result from the anchors being cut from plate, as
the anchors are typically planar and for correct orientation for
lifting require legs of the anchor to extend across a large portion
of the thickness of the concrete panel. Moreover, the applicant has
identified that a significant amount of waste material is produced
as a by-product in the manufacture of existing lifting anchors.
[0003] Examples of the invention seek to solve, or at least
ameliorate, one or more disadvantages of previous lifting
anchors.
SUMMARY OF THE INVENTION
[0004] In accordance with one aspect of the present invention,
there is provided a collar for an anchor for use in lifting a
concrete component, said anchor comprising a head portion engagable
with a clutch of a lifting system, and a body portion for embedment
with the concrete component, the collar including an attachment
portion for attaching the collar to the head portion of the anchor,
and an abutment portion adapted to provide a clutch abutment
surface for limiting rotation of the clutch relative to the
anchor.
[0005] Preferably, when the collar is fitted to the lifting anchor
the abutment portion forms the clutch abutment surface as a
shoulder adjacent the lifting anchor. More preferably, the clutch
abutment surface is formed as a shoulder adjacent the head portion
for limiting rotation of the clutch about an eye of the head
portion. More preferably still, the abutment portion provides a
shoulder adjacent each side of the head portion for limiting
rotation of the clutch about the eye in both directions of
rotation. The collar may include a gap between the shoulders which
coincides with the eye of the head portion to allow passage of the
clutch through the eye.
[0006] Preferably, the abutment portion is formed by an edge of the
collar.
[0007] In a preferred form, the collar fits around the head
portion, and is held to the head portion by way of a press fit.
[0008] Preferably, the collar is generally C-shaped.
[0009] In a preferred form, the collar includes at least one shear
bar attached to the collar. More preferably, the shear bar engages
in a groove of the collar. Preferably, the shear bar is welded to
the collar. In one example, the shear bar is formed in a generally
wave-like shape, with oscillations in a direction generally
perpendicular to a central axis of the anchor when the collar is
fitted to the anchor. More preferably, the collar includes a second
shear bar, wherein a major axis of the second shear bar is
generally parallel to a major axis of the first shear bar and is
substantially a mirror image of the first shear bar when viewed
from an end of the anchor.
[0010] In accordance with another aspect of the present invention,
there is provided an anchor for use in lifting a concrete
component, said anchor comprising a single length of wire bent to
form a head portion engagable with a clutch of a lifting system,
and a body portion for embedment with the concrete component,
wherein the anchor has a collar to provide clutch abutment surfaces
for limiting rotation of the clutch relative to the anchor, the
collar being a collar as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention is described, by way of non-limiting example
only, with reference to the accompanying drawings in which:
[0012] FIG. 1 is a perspective view of a lifting anchor having a
collar in accordance with an example of the present invention;
[0013] FIG. 2 is a perspective view of the anchor of FIG. 1, shown
with an associated chair;
[0014] FIG. 3 is a perspective view of the anchor, shown with the
chair fitted thereto;
[0015] FIG. 4 is a side view of the anchor, with the chair fitted
thereto;
[0016] FIG. 5 is a top view of the anchor, with the chair fitted
thereto;
[0017] FIG. 6 is a perspective view of the chair shown in
isolation, in a deconstructed condition; and
[0018] FIG. 7 is a perspective view of an edge of a concrete
component with the anchor embedded therein.
DETAILED DESCRIPTION
[0019] With reference to FIG. 1, there is shown an anchor 10 for
use in lifting a concrete component 12 (FIG. 7). The anchor 10
shown is in the form of an edge lift anchor, however it will be
appreciated by those skilled in the art that alternative examples
of the present invention may be in the form of other types of
anchors such as, for example, a face lift anchor.
[0020] The anchor 10 comprises a single length of wire 14 bent to
form a head portion 16 engagable with a clutch of a lifting system,
and a body portion 18 for embedment with the concrete component 12.
The wire 14 is bent such that opposed legs 20, 22 of the body
portion 18 extend in a plane substantially perpendicular to a plane
of the head portion 16. By virtue of the wire 14 being bent in this
way, the anchor 10 is able to be arranged such that the opposed
legs 20, 22 lie in a plane substantially parallel to a central
plane of the concrete component 12, while the head portion 16 is
oriented substantially perpendicularly to the central plane of the
concrete component 12. Advantageously, this enables the anchor 10
to be located lower in the concrete component 12 to facilitate edge
lifting of the concrete component 12, while facilitating a broad
spread of the opposed legs 20, 22 within the concrete component
12.
[0021] As the legs 20, 22 are spread outwardly from a central axis
24, the load applied to the anchor 10 is distributed through a
larger region of the concrete component 12 than is possible with a
typical concrete anchor having parallel legs. Accordingly, this
reduces the likelihood of the concrete component 12 failing during
lifting, as a large region of the concrete component 12 must fail
for the anchor 10 to be torn out during lifting. Each of the legs
20, 22 may be formed with a wave-like configuration by
incorporating a series of ripples to provide additional anchorage
of the anchor 10 within the concrete component 12. Advantageously,
the ripples inhibit withdrawal of the legs 20, 22 from the
concrete, by applying compression to the concrete during lifting.
As such, the opposed legs 20, 22 are able to provide the same
function as ancillary tension bars which have been used in existing
lifting anchors.
[0022] To achieve the perpendicular configuration, the head portion
16 in the example shown is twisted through an angle of 270 degrees
relative to the body portion 18 about the central axis 24 of the
anchor 10. In alternative anchors, to achieve a perpendicular
configuration the head portion may be twisted through an angle of
90 degrees (or, more generally, an angle of 90+180x, where x is a
non-negative integer) relative to the body portion 18 about the
central axis 24 of the anchor 10. The central axis 24 is in the
plane of the head portion 16. In this way, the plane of the head
portion 16 is perpendicular to the plane of the body portion
18.
[0023] It will be understood that, in alternative examples, the
body portion 18 may be rotated about the central axis 24 relative
to the head portion 16 such that the plane of the body portion 18
is out of the plane of the head portion 16 by an angle other than
90 degrees. In particular alternatives, this angle may be
approximately 60, 45, 30 or 15 degrees, as may be appropriate
depending on the shape and/or orientation of the concrete component
12.
[0024] The anchor 10 may be used for lifting concrete panels with
varying edge profile angles by, prior to embedment of the anchor 10
within the concrete panel, bending the head portion 16 out of the
plane of the legs 20, 22 by a corresponding angle. This bending may
be effected on site to suit the particular application. For
example, where the edge profile of the concrete panel is angled at
15 degrees, the head portion 16 of the anchor is correspondingly
bent upwards at an angle of 15 degrees relative to the plane of the
legs 20, 22. Similarly, where the edge profile of the concrete
panel is angled at 45 degrees, the head portion 16 of the anchor 10
is bent upwards to a corresponding angle of 45 degrees relative to
the plane of the legs 20, 22. It will be understood that the angle
to which the head portion is bent relative to the plane of the legs
20, 22 may vary between 0 and 90 degrees, however the most common
angles of edge profiles are 9 degrees, 15 degrees, 22.5 degrees, 30
degrees and 45 degrees.
[0025] The anchor 10 includes a collar 26 adapted to fit around the
head portion 16, as shown in FIG. 1. The collar 26 forms abutment
shoulders 28 at upper and lower locations of the head portion 16
for cooperation with a body of the clutch to limit clutch rotation
relative to the anchor 10.
[0026] More specifically, the collar 26 includes an attachment
portion 58 for attaching the collar 26 to the lifting anchor 10,
and an abutment portion 60 adapted to provide a clutch abutment
surface for limiting rotation of a clutch relative to the lifting
anchor 10. The attachment portion 58 is arranged for attaching the
collar 26 to the head portion 16 of the lifting anchor 10. When the
collar 26 is fitted to the anchor 10, the clutch abutment surface
is formed as an abutment shoulder 28 standing proud of each opposed
surface or side of the head portion 16 for limiting rotation of the
clutch about an eye 62 of the head portion 16, in both directions
of rotation. The collar 26 may include a gap 64 between the
shoulders 28 which coincides with the eye 62 of the head portion 16
to allow passage of the clutch through the eye 62.
[0027] The collar 26 is generally C-shaped, including a pair of
clasps for coupling to those parts of the head portion defining the
opposed surfaces or sides of the head portion 16, with a connecting
strip 66 between the clasps. Each clasp terminates in a tab 68
which secures the collar 26 to the head portion 16 by way of a hard
press fit. The abutment portion 60 is formed by an edge of the
collar 26, at each of the clasps.
[0028] The collar 26 includes a pair of shear bars 30, 32 attached
to the collar 26. The shear bars 30, 32 extend generally
perpendicularly to the central axis 24 and transverse to the plane
of the body portion 18. These shear bars 30, 32 assist in
preventing shear failure of the concrete component 12 during
lifting, and provide improved anchorage of the anchor 10 within the
concrete component 12. Each of the shear bars 30, 32 is formed in a
generally wave-like shape, with lateral oscillations 34 in a
direction generally perpendicular to the central axis 24 of the
anchor 10. A second one of the shear bars 30 is located adjacent a
first one of the shear bars 32, and is reversed such that the
second shear bar 30 is substantially a mirror image of the first
shear bar 32 when viewed from an end of the anchor 10. The shear
bars 30, 32 may be positively held in place relative to the head
portion 16 by engagement of the shear bars 30, 32 within grooves 36
formed in the collar 26. The grooves 36 formed on opposite sides of
the collar 26 may be formed in a correspondingly offset
configuration so as to positively locate the shear bars 30, 32 in
the arrangement shown. Alternatively, the shear bars 30, 32 may be
fixed relative to the head portion 16 by spot welding of the shear
bars 30, 32 to the collar 26.
[0029] The applicant has determined that the collar 26 is
particularly suited for use in providing a concrete component
lifting anchor formed of bent rod or wire with clutch abutment
surfaces for limiting rotation of a clutch relative to the lifting
anchor. This is because there is not the same ability in providing
anchors formed of bent wire with shoulders as there is with anchors
cut from plate. However, it is possible for collars formed in
accordance with other examples of the present invention to be used
with anchors formed from plate, and such collars may provide
various advantages over cut abutment shoulders. In particular,
using a collar according to an example of the present invention
provides the ability to interchange collars to change the
size/shape of abutment shoulders, and provides a convenient way to
attach shear bars to the anchor.
[0030] The collar 26 is preferably formed of metal, in particular
from folded steel. In other examples, the collar may be formed from
plastic.
[0031] Returning to the actual anchor itself, the length of wire or
rod 14 from which the anchor 10 is formed from a one-piece elongate
element shaped into the desired shape. More particularly, the
anchor 10 is formed from a length of metal rod which is bent to
form the anchor 10. The length of metal rod may be drawn from a
coil. Advantageously, by virtue of the anchor 10 being formed from
metal bar, material wastage is minimised, and the anchor 10 is
manufactured in a particularly cost-effective manner.
[0032] In particular, the head portion 16 is formed by bending the
metal rod around a forming piece (nor shown), the forming piece
being a pin having a size corresponding to the size of a clutch
portion to pass through the head portion 16. By virtue of this
forming process, any variation in the dimensions (particularly the
diameter) of the metal bar will not alter the size of the aperture
in the head portion 16. Accordingly, it is possible to provide a
superior tolerance for an effective, rigid coupling between the
clutch and the anchor, thus avoiding a sloppy coupling between the
anchor and the clutch. In other words, variation in the rod does
not affect quality of engagement between the anchor and the
clutch.
[0033] Also, by virtue of the anchor 10 being formed from round
cross-section metal rod, there is a single point of contact between
the clutch portion and the anchor 10, avoiding the problems
associated with skewed prior art anchors cut from metal plate which
tend to transfer undesirable forces to the concrete component
12.
[0034] With reference to FIG. 2, the anchor 10 forms part of an
anchor assembly 38 which includes a chair 40. The chair 40
comprises an upper part 44 and a lower part 46 which are fitted
together, with the upper part 44 having clips 48 for holding the
anchor 10 in place relative to the chair 40, as shown in FIGS. 3 to
5. FIG. 6 shows a detailed view of the upper part 44 and the lower
part 46 in isolation. As the body portion 18 is in a plane
perpendicular to the plane of the head portion 16, when in situ the
opposed legs 20, 22 do not extend below the head portion 16, thus
allowing the anchor 10 to be mounted in a relatively low position
within the concrete component 12, while ensuring the opposed legs
20, 22 are embedded inside the concrete component 12. More
particularly, the chair 40 is arranged for supporting the anchor 10
within the concrete component 12, with the plane of the body
portion 18 coplanar or oriented substantially parallel to a central
plane of the concrete component 12.
[0035] By virtue of the plane of the body portion 18 being coplanar
with or substantially parallel to a central plane of the concrete
component 12, it is possible for the body portion 18 to be located
at or within a neutral axis of the concrete component 12 so as to
avoid having the anchor embedded in regions of the concrete
component 12 which are under high compression and/or tension during
lifting. This may assist in avoiding failure of the concrete
component 12 during lifting, and may enable lifting of concrete
panels at a stage more premature (relative to the time of casting)
than is required for lifting using existing concrete anchors.
[0036] Furthermore, the feature of the plane of the body portion 18
being coplanar with or substantially parallel to the central plane
of the concrete component 12 enables the anchor to be used with
concrete panels much thinner than is required for lifting using
existing concrete anchors which extend transversely across a
substantial portion of the thickness of the panel.
[0037] FIG. 7 shows an edge of a concrete component 12 in which the
anchor 10 is embedded. A void 56 is formed around the head portion
16, and facilitates engagement of a clutch with the anchor 10 for
lifting of the concrete component 12. Although in this drawing the
anchor 10 is shown as being mounted in a central part of the
concrete component 12, it will be appreciated by those skilled in
the art that the anchor 10 may be mounted within the concrete
component 12 in a lower location such that the plane of the body
portion 18 is below the central plane of the concrete component
12.
[0038] While various embodiments of the present invention have been
described above, it should be understood that they have been
presented by way of example only, and not by way of limitation. It
will be apparent to a person skilled in the relevant art that
various changes in form and detail can be made therein without
departing from the scope of the invention. Thus, the present
invention should not be limited by any of the above described
exemplary embodiments.
[0039] In particular, although the example anchor depicted in the
drawings has an angle between the plane of the legs and the plane
of the head portion of approximately 90 degrees, it will be
understood that in alternative examples the angle between the plane
of the legs and the plane of the head portion may take other
values, for example 60, 45, 30 or 15 degrees. This angle may be
dictated by the shape and/or orientation of the concrete
component.
[0040] The reference in this specification to any prior publication
(or information derived from it), or to any matter which is known,
is not, and should not be taken as an acknowledgment or admission
or any form of suggestion that that prior publication (or
information derived from it) or known matter forms part of the
common general knowledge in the field of endeavour to which this
specification relates.
[0041] Throughout this specification and the claims which follow,
unless the context requires otherwise, the word "comprise", and
variations such as "comprises" and "comprising", will be understood
to imply the inclusion of a stated integer or step or group of
integers or steps but not the exclusion of any other integer or
step or group of integers or steps.
* * * * *