AU682977B2

AU682977B2 - Support anchor for concrete structures

Info

Publication number: AU682977B2
Application number: AU31582/95A
Authority: AU
Inventors: Ernest Comerford
Original assignee: Ezi Fix Anchors Pty Ltd
Current assignee: Ezi Fix Anchors Pty Ltd
Priority date: 1994-08-25
Filing date: 1995-08-17
Publication date: 1997-10-23
Anticipated expiration: 2015-08-17
Also published as: AU3158295A

Description

TITLE Support Anchor for Concrete Structures

FIELD OF THE INVENTION THIS INVENTION relates to a support. In one aspect, an embodiment of the invention concerns a support for reinforcing bars and reinforcing mesh.

BACKGROUND OF THE INVENTION The invention will be described by way of example with reference to a support for bars and mesh. It should be appreciated that this is by way of example only.

Supports for reinforcing bars and mesh, commonly called "bar chairs" are known. Such supports are provided of a variety of configurations, sizes and shapes. These chairs sometimes also support or space apart void formers as well as supporting bars and mesh. The chairs are encased in concrete and ensure that the bars and mesh are held and maintained in the desired location in the slab or floor. Typically, formwork is employed in casting the floor or slab and the bar chairs rest upon that formwork. Once the concrete is poured and has cured, the formwork is removed.

In the construction of floors in high rise or multi floor buildings, the floor slab between adjacent floors functions as a floor as well as the ceiling for a lower area in the building.

Services and a false ceiling are usually suspended from the slab and need to be secured to the slabs in some way. The formwork is removed and support rods for the services are then secured to the underside of the slab. Those supports cannot be secured to the slab until the formwork is removed.

When the formwork is removed, it is currently necessary to drill into the slab and place anchors into the holes for receiving support rods for services.

Alternatively, explosive tools are employed to drive fasteners into the slab and to secure the services to the slab.

Both of these techniques are tedious and require additional parts to be fitted to the slab before the support rods may be mounted in position. Although the support may be used to support reinforcing mesh or bars above formwork, the support need not be used for this purpose. The primary purpose of the support is facilitating connection of support rods or the like to concrete slabs or walls to allow services and ceilings to be readily attached to the slabs or walls.

It is an object of the present invention to provide a support which may support bars and mesh and which at least minimises the disadvantage referred to above. DISCLOSURE OF THE INVENTION

According to one aspect, the invention provides a support having a body, an end wall preferably having at least a partially removable portion and an anchor or connector within the body accessible through the end wall to enable a support rod or the like to be secured thereto whereby the body is configured to resist withdrawal from concrete in which it may be embedded.

The body of the support is preferably shaped or configured so that it resists withdrawal from the underside of a slab of concrete or a floor or wall of concrete in which it is embedded.

The support may have a shoulder or step between its ends to enable it to key with the concrete to inhibit withdrawal. Alternatively, the one end may be larger than the end which rests upon the formwork. Preferably, the support is tapered with, the taper extending from the one end to the other end. Thus two sides of the support may extend towards one another from the one end to the other end. Alternatively, where the support has more than two sides, all of the sides may be tapered in this way.

In one embodiment, the support may have a continuous side wall and be configured in a substantially frustoconical form to provide for this keying with the concrete in which it is embedded.

The support preferably has supporting recesses or projections which may support the bars or mesh. The recesses preferably are present at two depths from the end wall. In one embodiment, the recesses are present in a cruciform configuration in an end spaced from the end wall although other configurations may also be employed. As an alternative to this, the bars or mesh may simply rest upon an end of the body spaced from the end wall.

The removable wall portion , if present, preferably forms part of a bottom wall of the body. Preferably, the wall portion is completely removable from the bottom wall. The height of the body may be chosen to ensure that the reinforcing mesh or bars are supported at the desired distance from the upper surface of the formwork upon which the support may rest.

The body may have a removable lid spaced from the end wall. The lid may be a frictional or snap fit relative to the body. Support portions may be present on an outer face of the lid. Preferably, the support portions include one or more ribs.

The anchor or connector within the body may have an anchor portion to which a support rod may be attached. In one embodiment, the anchor portion comprises a threaded stud or threaded aperture. Alternatively, the anchor has an apertured portion or eyelet to which a support rod or the like may be secure.

The anchor may be rendered accessible when the partially removable portion is removed from the body. The anchor may simply be rendered accessible from outside the body when the portion is removed. Alternatively, removal of a portion of the end wall may allow the anchor to move so that it projects partially from the body. The anchor may be biased so that it is moved to project from the body when the portion of the end wall is removed. Biasing means may be present within the housing for this purpose. By driving the anchor from the body, it is rendered accessible and this allows the support to be employed for securing objects to vertical or sloping walls as well as to horizontal floors or slabs. The biasing means may comprise a spring acting upon the anchor. Preferably the spring is located between that end of the housing distant from the end wall and the anchor. A coil spring is preferred. The distal end of the body may be substantially cylindrical in shape and the spring may normally be housed within that end of the body.

DISCLOSURE OF THE DRAWINGS Particular preferred embodiments of the invention will now be described with reference to the drawings in which: Figure la is a plan view of a support for reinforcing according to one embodiment of the invention;

Figure lb is a sectional elevational view of the support of Figure la taken along line II of Figure la; Figure 2 is a sectional elevational view of the support taken along line II-II of Figure la;

Figure 3 is a view like Figure lb showing greater detail of one of the threaded apertures in the support; Figure 4 is an exploded perspective view of a support according to an embodiment of the invention;

Figure 5 is an exploded elevational view of the support shown in Figure 4;

Figure 6 is an assembled side elevational view of the support of Figures 4 and 5;

Figure 7 is an assembled side elevational view of the support in a configuration ready to support a supporting rod for services or a false ceiling;

Figure 8 is a transverse view of one embodiment of support shown in a first position;

Figure 9 is a transverse view of the support of Figure 8 shown in a second position;

Figure 10 is a transverse view of a support of a second embodiment shown in a first position; and

Figure 11 is a transverse view of the support of Figure 10 shown in a second position.

DETAILED DESCRIPTION OF THE DRAWINGS The support 10 shown in Figures la and lb has an upper end 11 into which is formed two sets of bar or mesh recesses in a cruciform pattern. One cruciform recess 12 extends into the end 11 to a greater depth than the other cruciform recess 13. Reinforcing bars or mesh may be received in either of recesses 12 or 13 and thus may be selectively supported at different distances from lower end 14 of the support. In order to achieve this the support may be placed with end 14 on the formwork and rotated so that the bars or mesh locate in selected recesses 12 or 13.

The support 10 has tapered sides 15, 16, 17 and

18 such that end 11 has a greater area than end 14. In this way, once concrete has been cast about the support

10, the support resists withdrawal from the underside of the concrete slab.

The support 10 has a central aperture 19 and four further apertures 20, 21, 22, 23 spaced around aperture 19. These apertures are present as blind bores so that concrete poured over the support does not fill the apertures. Web 24 spaces the apertures from end 11.

Each of these apertures is thread as shown by the numeral 25 in Figure 3.

In use, formwork is placed in position to define the location of a concrete slab. Supports 10 are positioned at selected locations on the formwork and at locations along which services such as water pipes, cable trays and air conditioning ducts or the like are intended to extend. Reinforcing bars or mesh are placed to extend over and be supported by the supports at a predetermined height above the formwork. Concrete may then be poured over the mesh, bars and supports to embed them within the concrete.

After the concrete has cured, the formwork may then be removed. The ends 14 of the supports are then visible on the underside of the slab and the threaded apertures within the supports are accessible. Threaded support rods may be screwed into selected ones of the threaded apertures to enable the required services to be supported at the desired locations beneath the slab.

The person pouring the slab would be aware of the required locations at which the supports should be positioned to define locations along the underside of the resultant slab along which the services would need to extend.

Figures 4 and 5 show a support 30 having a lid 31, an anchor 32 and a body 33. The lid may be fixed to the body in any suitable way. For example, the lid 31 may frictionally engage with the body 33. The lid 31 has ribs 34, 35 arranged in a cruciform pattern on which reinforcing bars or mesh may rest. The lid may be made in a variety of thicknesses and this may facilitate proper spacing of bars or mesh. The anchor has a main part 36 from which eyelet

37 extends. The eyelet has an aperture 38.

The body 33 has an open top and provides a chamber 41 within which the anchor may be received. The anchor is normally concealed within the body 33 when the lid 31 is mounted relative to the body 33. The body 33 has a bottom wall 42 with a central frangible removable wall portion or removable membrane 43 of a thickness substantially less than the thickness of the remainder of the bottom wall 42. The removable wall portion 43 when removed from the bottom wall 42 allows the eyelet to be accessed and drawn through the resultant opening in the bottom wall 42 of the body 33.

The body 33 has opposed wings 33a with apertures 33b for receiving nails to allow the support to be secured to the formwork. The lid 31 has opposed lobes 31a with apertures 31b. Thus, once the lid is secured to the body two nails may be employed to not only secure the lid firmly to the body but to secure the body and lid to the support.

Figure 6 shows the support 30 in its assembled condition with the anchor located within the body 33 and concealed by the cover 31. The support 30 is shown resting upon formwork. The removable wall portion 43 is still intact and the eyelet remains within the body. Reinforcing bars or mesh (not shown) may be supported by the lid 33 of the support 30 and concrete poured over the support. Concrete is prevented from entering the space within the support by the cover and the intact removable wall portion. Once the concrete has set, the formwork 45 may be removed.

Figure 7 shows a lower face 46 of a concrete slab and the formwork is no longer present. The frangible wall portion is either broken or removed in its entirety and the anchor 32 is partially drawn through the resultant opening in the bottom wall portion of the body 33. The main part 36 prevents the anchor from being separated from the body. Aperture 38 is now available and a support rod or other means may be secured to the anchor 32 to enable a false ceiling or other building services to be suspended from the slab.

The supports 30 may be carefully and selectively positioned on the formwork to correspond with locations on the resultant slab from which services or the like are to be positioned. If desired, the supports 30 may be secured to the formwork such as by nails, staples or the like to ensure that unwanted displacement of them does not occur during pouring of the slab. Figure 8 shows the support 50 embedded in a vertical concrete wall 51. Formwork has been removed from the wall to expose a surface 52 to which objects are to be secured.

The support 50 has a housing or body 53 of relatively thin wall construction having a tapered portion 54 adjacent end wall 55. The end wall has a portion 56 defined by a frangible zone 57 which may be removed once the formwork is removed. The body 53 has a connector or anchor 58 located within it normally in a first position within the body. The anchor 58 consists of a threaded stem 59 and a tapered retainer 60. The taper on the retainer matches the taper on the portion 54 and when the retainer locates relative to the taper on portion 54, the connector stem is prevented from separating from the body. A spring 61 is located at an end of the body remote from end wall 55 and functions to bias the connector 58 from the first position of Figure 1 to the second position in Figure 9.

The support of Figure 8 is located at spaced locations within a wall cavity defined by formwork and concrete may then be poured. Once the concrete has cured and the formwork removed, the end walls of a plurality of supports 50 are then visible in surface 52. The end walls may be removed to cause the connector to be moved to the second position shown in Figure 9. Objects may be coupled to the stem.

With the arrangement shown in Figures 8 and 9, it is possible to employ the supports for coupling objects to vertical walls.

Figures 10 and 11 show a support similar to that of Figures 8 and 9 except that no spring is present. The support 65 has a body 66 with a tapered portion 67. End wall 68 has a frangible zone 69 which allows a portion of the end wall to be removed to render the connector 70 accessible. The connector has a threaded stem 71 and a retainer 72. Retainer 72 has a tapered wall matching the taper on body 67 and prevents the connector from separating from the housing.

The support of Figures 10 and 11 is installed in a similar manner to the support of Figures 8 and 9 except that when installed in a horizontal floor or wall the connector moves to its second position under the influence of gravity once part of the end wall is removed. The support of Figures 10 and 11 may also be used in vertical walls except that once the end wall is removed, the stem must be manually moved to the Figure 11 position.

Claims

CLAIMS ;

1. A support having a body, an end wall preferably having at least a partially removable portion and an anchor or connector within the body accessible through the end wall to enable a support rod or the like to be secured thereto, whereby the body is configured to resist withdrawal from concrete in which it may be embedded.

2. The support of Claim 1 wherein the anchor consists of at least one threaded bore extending into the body from the end wall.

3. The support of Claim 2 wherein there are five said threaded bores extending into the body from the end wall.

4. The support of Claim 1 having a stepped periphery on the body to allow the support to resist withdrawal from concrete in which it may be embedded.

5. The support of Claim 1 wherein the body is tapered to resist withdrawal from concrete in which it may be embedded.

6. The support of Claim 1 wherein the body is frustoconical in shape to resist withdrawal from concrete in which it may be embedded.

7. The support of Claim 2 having recesses in an upper end spaced from the end wall, said recesses being adapted for receiving and supporting reinforcing bars or mesh.

8. The support of Claim 7 wherein the recesses are present at two depths.

9. The support of Claim 1 wherein the body is hollow and has a removable lid at an end spaced from the end wall.

10. The support of Claim 9 wherein the lid is either a snap or frictional fit relative to the body.

11. The support of Claim 10 wherein the anchor is located within the body and when the partially removable portion is removed from the end wall, the anchor is movable from a first position entirely within the body to a second accessible position where the anchor projects from the body.

12. The support of Claim 11 wherein the anchor has a main part which prevents it from being separated from the body and an eyelet with an aperture relative to which a support rod or other member may be secured.

13. The support of Claim 11 wherein the anchor has a main part which prevents it from being separated from the body and a stem projecting from the main part to which a support rod or other member may be secured.

14. The support of Claim 11 including biasing means within the body for causing the anchor to move to the second position once the removable portion is removed from the end wall.

15. The support of Claim 14 wherein the body has a cylindrical shape at one end within which the biasing means is located and a frustoconical shape adjacent the end wall.

16. The support of Claim 13 wherein the stem is threaded.

AMENDED CLAIMS

[received by the International Bureau on 18 January 1996 (18.01.96); original claims 1-16 replaced by new claims 1-6 (1 page)]

1. A support having a body, an end wall preferably having at least a partially removable portion and an anchor or connector located within the body and when the assembly portion is removed from the end wall, the anchor is movable from a first position entirely within the body of a second accessible position where the anchor projects from the body to enable the support rod or the like to be secured thereto, whereby the body is configured to resist withdrawal from concrete or other substances in which it may be embedded.

2. The support of Claim 1 wherein the anchor has a main part which prevents it from being separated from the body and an eyelet with an aperture relative to which a support rod or other member may be secured.

3. The support of Claim 1 wherein the anchor has a main part which prevents it from being separated from the body and a stem projecting from the main part to which a support rod or other member may be secured. 4. The support of Claim 1 including biasing means within the body for causing the anchor to move to the second position once the removable portion is removed from the end wall.

5. The support of Claim 4 wherein the body has a cylindrical shape at one end within which the biasing means is located and a frustoconical shape adjacent the end wall.

6. The support of Claim 3 wherein the stem is threaded.