NZ603277B

NZ603277B - Lifting anchors

Info

Publication number: NZ603277B
Application number: NZ603277A
Authority: NZ
Inventors: Alistair M Wood
Original assignee: Illinois Tool Works Inc
Filing date: 2012-10-25
Publication date: 2014-08-01

Abstract

603277 Disclosed is a lifting anchor for incorporation into a concrete panel prior to casting to provide a lifting point by which the panel can subsequently be lifted. The anchor comprises a first lifting head (2) for releasable engagement with a lifting clutch in an edge lifting configuration and a second lifting head (16) for engagement with a lifting clutch in a face lifting situation. The anchor therefore provides the option of lifting a concrete panel from the face side, which avoids the potential for damage to the panel when lifting from the edge side. d a second lifting head (16) for engagement with a lifting clutch in a face lifting situation. The anchor therefore provides the option of lifting a concrete panel from the face side, which avoids the potential for damage to the panel when lifting from the edge side.

Description

C:SNR.PanbrOCCOLNI46243:41 I DOC-23(10i21111 LIFTING ANCHORS The present invention relates to lifting anchors for incorporation into a concrete panel prior to casting in order to provide lifting points by which the panel can subsequently be lifted.

When panels are cast in a factory situation remote from the site of erection it is normal practice to incorporate edge lift anchors in which a head of the anchor is within a void opening onto an edge of the panel for engagement with a corresponding clutch of a lifting shackle. The edge lift anchors are used to lift the panel from the casting bed, to load the panel onto a truck for transportation to site, and then to lift the panel into its erected position. A difficulty does however arise when the edge of the panel is shaped with an upstanding lip designed to engage into a recess in the lower edge of a panel to be placed on the first panel in the erected state to thereby form a weather seal between the two. The presence of the lip at the edge at which lifting takes place may lead to interference between the shackle plate of the lifting shackle and the lip with the potential of damage to the lip in the initial lifting configuration in which the panel is being lifted from the casting bed from the horizontal configuration in which it is cast, to a generally vertical configuration at which all subsequent lifting takes place for the purposes of transportation and erection.

The present invention relates to a lifting anchor having capability either as an edge lift anchor or as a face lift anchor whereby initial lifting of the panel from the casting bed to a generally vertical configuration can take place from the face of the panel rather than the edge thereby avoiding the potential for damage as discussed above, with subsequent lifting for transportation and erection taking place from the edge.

According to the present invention there is provided a lifting anchor for incorporation into a concrete panel prior to casting to provide a lifting point by which the panel can subsequently be lifted, the anchor having a first lifting head for releasable engagement with a lifting clutch in an edge lifting configuration and a second anchor head for engagement with a lifting clutch in a face lifting situation.

CANRPertbrOCCOLION1-71131 DOC-21/1012017 In a preferred embodiment, the anchor has a foot to provide shear capacity in concrete without the need for a conventional shear bar. It also has means enabling one or more tension bars to be installed to the anchor.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of a lifting anchor in accordance with the preferred embodiment of the invention; Figure 2 is an exploded view of the anchor of Figure 1; and Figure 3 is a highly diagrammatic view showing the anchor installed within a panel and showing its co-operation with a lifting clutch in edge lift and face lift configuration.

The lifting anchor in accordance with the preferred embodiment of the invention comprises at its forward end a head 2 for engagement with a lifting clutch in an edge lifting mode.

The head 2 includes an eye 4 for engagement with a locking bolt of the clutch and lateral abutments 6 for engagement with the body of the clutch so as to restrict rotation of the clutch body. This form of anchor head and its co-operation with the body of the clutch is well known and is described in detail in Australian patent 639908. Beyond the anchor head 2, the body of the anchor is formed as two legs 8, 10. The end of each of the legs remote from the head 2 is formed with an aperture 12 for receipt of a tension bar which will typically consist of a length of reinforcing bar inserted through the aperture and then bent to form two legs to extend further into the depth of the panel. This is illustrated in Figure 3 in which the tension bars are designated at 14. This configuration permits a perimeter bar to be placed centrally within the panel and with a minimum of cover by the concrete.

The upper of the two legs 8 is configured to form an anchor head 16 for use in face lifting mode and includes an eye 18 for engagement with the bolt of the lifting clutch and an abutment surface 20 engageable by the body of the clutch. It will be understood from the drawings that the two anchor heads, 2 for edge lifting and 16 for face lifting are thereby oriented in mutually perpendicular directions. The lower edge of the lower leg 10 is C SNR Porlti OCC,DLNR M24331 1 DOC-21, if I/2 L /12 recessed to receive a laterally-projecting bar or foot 22 which extends laterally to each side of the lower leg from the forward end of the anchor rearwardly to a position adjacent the aperture 12 for the tension bar. The foot 22 is attached to the leg by welding although in an alternative embodiment it could be formed integrally with the lower leg by forging.

The foot is important to provide anchorage against shear forces which arise during lifting from a horizontal to a vertical configuration of the panel, although other means of providing the necessary shear anchorage could be adopted; in the diagrammatic illustration of Figure 3, the foot has been omitted. The use of the foot 22 avoids the need for a conventional shear bar.

Figure 3 shows schematically the anchor in its installed condition with the edge lifting head at the forward end of the anchor being exposed to the edge of the panel, and the face lifting head the upper side of the upper leg being exposed to the upper face of the panel. It is to be understood that Figure 3 is highly diagrammatic and although it shows lifting clutches and associated shackle plates attached to each of the lifting heads, at any one time only one lifting clutch will be present on the anchor depending on the type of lifting required at the time. Figure 3 does however also serve to illustrate how the shackle plate of the clutch coupled to the edge lift head will interfere with the projecting edge lip 32 of the panel edge if the panel were to be edge lifted from its horizontal configuration on the casting bed. By use of the anchor of the preferred embodiment, that first lifting stage is affected by coupling the clutch to the face lifting head whereby the action which occurs is that of face lifting which will not result in damage to the projecting lip. All subsequent lifting when the panel is generally vertical will be lifting from the edge of the panel using the edge lift head.

Although the anchor in accordance with the preferred embodiment has been designed for use both as a face lift anchor and an edge lift anchor in different lifting stages of the panel, it might also function as a "universal" anchor which, when installed within the panel, can be used just for edge lifting or just for face lifting. In that case the anchor head which is not going to be used for lifting will be fully enclosed within the concrete of the panel.

C1NRPoribaDCODLItf4(.2413)_1. DaC.231111/21)12 The embodiment has been described by way of example only and modifications are possible within the scope of the invention.

C \NRPoriblUCC1DLV,1524112_1 DOC-22/In121)12

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A lifting anchor for incorporation into a concrete panel prior to casting to provide a lifting point by which the panel can subsequently be lifted, the anchor having a first lifting 5 head for releasable engagement with a lifting clutch in an edge lifting configuration and a second lifting head for engagement with a lifting clutch in a face lifting situation.

2. A lifting anchor according to claim 1, wherein each lifting head comprises an eye for engagement with a locking bolt of the lifting clutch and at least one abutment surface 10 for engagement by a body of the lifting clutch, the two lifting heads being oriented in mutually perpendicular orientations.

3. A lifting anchor according to claim I or claim 2, wherein the lifting anchor has a body comprising two substantially parallel legs extending from the first lifting head and 15 the second lifting head extends laterally outwardly from one of the legs.

4. A lifting anchor according to claim 3, wherein an aperture is formed at an end of each of the legs remote from the lifting head to receive a tension bar. 20

5. A lifting anchor according to claim 4, wherein the second lifting head is positioned on the said one leg between the first lifting head and the tension bar aperture at the remote end of that leg.

6. A lifting anchor according to any one of claims 3 to 5, wherein the other leg 25 includes a foot configured to provide anchorage against shear forces arising during lifting from a horizontal to a vertical configuration of the panel in a face lifting situation using the second lifting head. A lifting anchor according to any one of claims 1 to 6 when used within a concrete 30 panel having a lip extending from an edge of the panel to form a weather seal with an adjacent concrete panel by engagement into a recess in the adjacent panel.