NZ759989A

NZ759989A - Void former

Info

Publication number: NZ759989A
Application number: NZ759989A
Authority: NZ
Inventors: Gurtler Arno
Original assignee: Plastic Solutions Australia Pty Ltd
Priority date: 2018-12-11
Filing date: 2019-12-09
Publication date: 2021-06-25
Also published as: AU2019279924A1

Abstract

Void formers are used during casting of a concrete element to create a void around the head 3 of a lifting anchor 5 which is to be embedded in the concrete element. During casting, concrete slurry can seep around the head 3 of the anchor and into the lifting eye 15 in the head 3 making it difficult for a ring clutch of a lifting assembly to access and lift the concrete element. The void former 1 of the present includes two body sections 7, 9 hinged together at upper portions thereof. At least one of the body sections 7, 9 includes an annular sealing rib configured to deform radially inwardly upon abutment with an inner wall of the lifting eye 15 to advantageously seal and prevent the ingress of cement slurry into the lifting eye 15 during casting.

Description

VOID FORMER FIELD OF THE INVENTION The invention relates to a void former for forming a void around the head of a lifting anchor incorporated into a concrete element such as a concrete panel, beam or column prior to casting of the concrete.

BACKGROUND TO THE INVENTION Lifting anchors are commonly used in the lifting and handling of concrete pre-cast elements such as panels in the construction industry. Lifting anchors typically include a pair of generally parallel legs which are embedded in the concrete panel to provide anchorage. A head of the lifting anchor remains exposed in a recess formed in an edge of the panel. The head includes some form of eyelet aperture to facilitate releasable engagement with a lifting shackle assembly associated with a crane to enable lifting of the panel.

Prior to the casting of a concrete element, for example a concrete panel, lifting anchors are suitably positioned together with reinforcing elements in a mould or formwork. The head of an anchor is typically secured prior to casting in a removable void former. Void formers are typically designed to abut against opposing faces of the anchor in order to prevent the ingress of concrete slurry into the region of the lifting eye during casting. After the concrete has hardened, the void former is removed leaving a recess in the edge of the concrete panel around the head such that a ring clutch of a lifting shackle assembly can then access and engage the lifting eye within the recess.

It would be desirable to provide a void former of the above described general type which has one or more improved features. 17692814_1 (GHMatters) P44625NZAU Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art on or before the priority date of the claims herein.

SUMMARY OF THE INVENTION According to a first aspect of the invention, there is provided void former for application to a head of a lifting anchor prior to casting concrete around the anchor to form a concrete element, said anchor head having a through aperture, the void former including: the two body sections hinged together at upper portions thereof to define therebetween a cavity which is shaped to receive the head of the anchor, the two body sections being moveable between a closed position in which said body sections engage around the head of the anchor and an open position in which said sections are separated at a lower portion thereof to enable release of the anchor, at least one of the body sections including an annular sealing rib configured to deform radially inwardly upon abutment with an inner wall of the through aperture, wherein, when the body sections are in the closed position, the sealing rib abuts the inner wall of the through aperture to prevent the ingress of cement slurry into the aperture during casting.

According to another aspect of the invention, there is provided a void former for application to the head of a lifting anchor prior to casting concrete around the anchor to form a concrete element, said lifting anchor having a pair of opposed faces with the head of the anchor having a through aperture extending between said opposed faces, the void former including: two body sections hinged together at upper portions thereof to define therebetween a cavity having interior walls provided by opposing end walls of the 17692814_1 (GHMatters) P44625NZAU body sections, the cavity being shaped to receive the head of the anchor, the two body sections being moveable between a closed position in which said opposing ends walls abut the faces of the anchor head, and an open position in which said body sections are separated at a lower portion thereof to release the anchor, at least one of the body sections including an annular sealing member projecting from the end wall, the annular sealing member being deformed radially inwardly by abutment with the anchor head aperture in the closed position to prevent the ingress of cement slurry into the aperture during casting, wherein a portion of the annular sealing member nearest the hinge projects away from the end wall a shorter distance than a portion of the annular sealing member furthest from the hinge.

According to another aspect of the invention, there is provided a void former for application to the head of a lifting anchor prior to casting concrete around the anchor to form a concrete element, said lifting anchor having a pair of opposed faces with the head of the anchor having a through aperture extending between said opposed faces, the through aperture being formed in a main portion of the head, the head further including at least one wing portion, the head of the anchor being of non-uniform thickness with the thickness between the opposed faces in the main portion of the anchor head being greater than the thickness between the opposed faces in the at least one wing portion of the anchor head such that a ledge is provided between the main portion and the at least one wing portion, void former including: two body sections hinged together at upper portions thereof to define therebetween a cavity having interior walls provided by opposing end walls of the body sections, the two body sections being moveable between a closed position in which said opposing ends walls abut the faces of the anchor head, and an open position in which said body sections are separated at a lower portion thereof to enable release the anchor, wherein the end wall of at least one of the body sections is shaped to match the non-uniform thickness of the anchor head and includes an annular 17692814_1 (GHMatters) P44625NZAU sealing rib configured to deform radially inwardly upon engagement with an inner wall of the through aperture.

To assist in further understanding the invention, reference will now be made to the accompanying drawings which illustrate preferred embodiments. It is to be appreciated that these embodiments are given by way of illustration only and that the invention is not to be limited by these illustrations.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a void former in accordance with an embodiment of the invention attached to an anchor prior to casting of the anchor in a concrete element, the void former being illustrated in a closed position with respect to the head of the anchor; Figure 2 is a sectional view taken along line A-A in Figure 1 of the void former illustrated in Figure 1, the void former being illustrated in an open position with respect to the head of the anchor; Figure 2A is a perspective view of one of the body sections of the void former illustrated in Figure 1, the view illustrating the end wall of the body section, Figure 3 is a fragmentary sectional enlarged view taken along line A-A in Figure 1 illustrating the void former in an open position with respect to the head of the anchor.

DESCRIPTION OF PREFERRED EMBODIMENTS With reference to the accompanying drawings there is shown a void former 1 in accordance with an embodiment of the invention for application to the 17692814_1 (GHMatters) P44625NZAU head 3 of a lifting anchor 5 prior to casting concrete around the anchor 5 to form a concrete element, for example a concrete panel. The void former 1 incorporates a range of improved features over conventional void formers commonly used in the casting of concrete elements in the construction industry.

The void former 1 in accordance with an embodiment of the invention includes a pair of body sections 7, 9 which are hinged together at upper portions thereof to define therebetween a cavity 11. In this regard, the two body sections 7, 9 have a central region 8 which is flexible and acts as a hinge. The cavity 11 is shaped to receive the head 3 of the anchor 5. The void former 1 is preferably moulded in one piece with the two body sections 7, 9 being able to pivot about the central hinge region 8 between a closed position in which said body sections 7, 9 engage around the head 3 of the lifting anchor 5 (as illustrated in Figure 1), and an open position in which the sections 7, 9 are separated at a lower portion thereof to enable release of the anchor 5 (as illustrated in Figures 2 and 3).

With reference to Figures 1 and 2, the anchor 5 includes opposing faces 19, 21 with the head region 3 having a through aperture which is preferably in the form of a lifting eye 15 which facilities releasable engagement of the anchor with a ring clutch of a lifting shackle assembly. The void former 1 is intended to abut against the opposing faces 19, 21 in the head region 3 to prevent the ingress of concrete slurry onto the faces 19, 21 and into the lifting eye 15 during casting.

In this respect, side walls of the cavity 11 in which the anchor head 3 is received are provided by opposing end walls 23, 25 of the body sections 7, 9 which abut the anchor head 3 in the closed position.

Each body section 7, 9 may include a sealing member which projects orthogonally from the end wall 23, 25. The sealing member is preferably in the form of an annular sealing rib 13 for engaging by friction fit within the lifting eye . When the body sections 7, 9 of the void former 1 are in the closed position, 17692814_1 (GHMatters) P44625NZAU the sealing ribs 13 abut an interior wall 17 of the lifting eye 15 at opposite ends to thereby prevent the ingress of cement slurry into the lifting eye 15 during casting of the concrete element. The void former 1 can be removed from the head 3 of the anchor 5 once the cast concrete has hardened. In this respect, each body section 7, 9 is pivoted outwardly about the central hinge region 8 to thereby release the sealing ribs 13 from the lifting eye 15. Once the body sections 7, 9 have been moved to the open position illustrated in Figures 2 and 3, the void former 1 can be lifted away from the head 3 of the anchor 5.

The sealing ribs 13 are preferably made of a flexible plastic or rubber material such that the sealing ribs 13 can be radially deformed inwardly by engagement with the interior wall 17 of the lifting eye 15 such that the sealing ribs 13 are pressed firmly against the interior wall 17 in the closed position. With reference to Figures 2, 2a and 3, each sealing rib 13 preferably includes a generally curved free end and increases gradually in thickness from the free end to a base of the sealing rib 13 adjacent the end wall 23, 25. The free end of the annular sealing rib 13 preferably lies in a plane at an acute angle to the end wall 23. In this regard, as shown in Figures 2 and 3, a portion of the annular sealing rib 13 closest to the central hinge region 8 projects orthogonally from the end wall 23 a shorter distance than a portion of the annular sealing rib 13 which is furthest from the hinged region 8. More specifically, the distance the annular sealing rib 13 projects from the end wall 23 increases gradually from nearest to furthest the hinged region 8 to provide an inclined free end with respect to the end wall. This arrangement of the annular sealing rib 13 advantageously enables the sealing rib 13 to be free of the lifting eye 15 at a less acuate opening angle of the body sections 7, 9 than would otherwise be the case. As illustrated in Figures 2 and 3, the outer free end of the sealing ribs 13 are also advantageously slightly spaced from and substantially parallel to the corresponding opposed faces 19, 21 of the anchor 5 in the open position.

The void former 1 is preferably designed to be used in conjunction with a lifting anchor 5 of the type illustrated in Figure 1 in which the lifting eye 15 is 17692814_1 (GHMatters) P44625NZAU formed in a centrally located main portion 27 of the head 3. The head 3 further includes a pair of wing portions 29 which are preferably provided at opposite ends of the main portion 27. As can be seen from Figure 1, the head 3 is advantageously of non-uniform thickness in an axial direction (X axis) with the thickness of the winged portions 29 being preferably uniform, but less than the uniform thickness of the main portion 27 such that a step or ledge 31 is provided between the main and winged portions 29. To accommodate the ledge 31 in the head of the anchor the end walls 23, 25 of the void former 1 are shaped to match the non-uniform thickness of the anchor head 3. In this regard, each end wall 23, includes an indented region 33 within which the main portion 27 of the anchor head 3 seats when the void former 1 is in the closed position. Each body section end wall 23, 25 further includes an outer wall region 35 for abutting with the wing portions 29 in the closed position. The indented region 33 includes an outer peripheral side wall 39 for abutting with the ledge 31 of the anchor in the closed position. The outer peripheral side wall 39 creates a tortured path to restrict the flow of cement slurry into the indented region 33 during casting. In this regard, the outer peripheral side wall 39 advantageously minimises the potential for concrete slurry during concrete casting to seep into the lifting eye 15 from between the side edges of the anchor head 3 and the void former 1 by retarding flow. The outer peripheral side wall 39 provided between the indented region 33 and outer wall region 35 creates a diverging/tortured path which impedes concrete slurry reaching the lifting eye 15 of the head 3 during casting. 17692814_1 (GHMatters) P44625NZAU

Claims

CLAIMS :

1. A void former for application to a head of a lifting anchor prior to casting concrete around the anchor to form a concrete element, said anchor head having a through aperture, the void former including: the two body sections hinged together at upper portions thereof to define therebetween a cavity which is shaped to receive the head of the anchor, the two body sections being moveable between a closed position in which said body sections engage around the head of the anchor and an open position in which said sections are separated at a lower portion thereof to enable release of the anchor, at least one of the body sections including an annular sealing rib configured to deform radially inwardly upon abutment with an inner wall of the through aperture, wherein, when the body sections are in the closed position, the sealing rib abuts against the inner wall of the through aperture to prevent the ingress of cement slurry into the aperture during casting.

2. A void former as claimed in claim 1 wherein the sealing rib includes a generally rounded free end, and the sealing rib increases in thickness from the free end to a base of the sealing rib.

3. A void former for application to the head of a lifting anchor prior to casting concrete around the anchor to form a concrete element, said lifting anchor having a pair of opposed faces with the head of the anchor having a through aperture extending between said opposed faces, the void former including: two body sections hinged together at upper portions thereof to define therebetween a cavity having interior walls provided by opposing end walls of the body sections, the cavity being shaped to receive the head of the anchor, the two body sections being moveable between a closed position in which said opposing ends walls abut the faces of the anchor head, and an open position in which said 17692814_1 (GHMatters) P44625NZAU body sections are separated at a lower portion thereof to release the anchor, at least one of the body sections including an annular sealing member projecting from the end wall, the annular sealing member being deformed radially inwardly by abutment with the anchor head aperture in the closed position to prevent the ingress of cement slurry into the aperture during casting, wherein a portion of the annular sealing member nearest the hinge projects away from the end wall a shorter distance than a portion of the annular sealing member furthest from the hinge.

4. A void former as claimed in claim 4 wherein the distance the annular sealing member projects from the end wall increases gradually from nearest to furthest the hinge with an outer free end of the annular sealing member lying in a plane which is angled with respect to the end wall, said plane being spaced from and substantially parallel to the face of the anchor when the body sections are in the open position.

5. A void former for application to the head of a lifting anchor prior to casting concrete around the anchor to form a concrete element, said lifting anchor having a pair of opposed faces with the head of the anchor having a through aperture extending between said opposed faces, the through aperture being formed in a main portion of the head, the head further including at least one wing portion, the head of the anchor being of non-uniform thickness with the thickness between the opposed faces in the main portion of the anchor head being greater than the thickness between the opposed faces in the at least one wing portion of the anchor head such that a ledge is provided between the main portion and the at least one wing portion, void former including: two body sections hinged together at upper portions thereof to define therebetween a cavity having interior walls provided by opposing end walls of the body sections, the two body sections being moveable between a closed position in which said opposing ends walls abut the faces of the anchor head, and an open position in which said body sections are separated at a lower portion thereof to enable release the anchor, 17692814_1 (GHMatters) P44625NZAU wherein the end wall of at least one of the body sections is shaped to match the non-uniform thickness of the anchor head and includes an annular sealing rib configured to deform radially inwardly upon engagement with an inner wall of the through aperture.

6. A void former as claimed in claim 6 wherein said end wall of at least one of the body sections further includes an indented region within which the main portion of the anchor head seats in the closed position.

7. A void former as claimed in claim 7 wherein said end wall of at least one of the body sections further includes an outer wall region for abutting with the at least one wing portion of the anchor in the closed position.

8. A void former as claim in claim 8 wherein the indented region includes an outer sidewall for abutting with the ledge of the anchor in the closed position, the outer sidewall creating a tortured path to restrict the flow of cement slurry into the indented region during casting. PLASTIC SOLUTIONS AUSTRALIA PTY LTD P44625NZAU 17692814_1 (GHMatters) P44625NZAU