AU2012313343B2

AU2012313343B2 - Anchor assembly

Info

Publication number: AU2012313343B2
Application number: AU2012313343A
Authority: AU
Inventors: Darek SYGIDUS; Tadeusz SYGIDUS
Original assignee: EZI BOLT SYSTEMS Pty Ltd
Current assignee: EZI BOLT SYSTEMS Pty Ltd
Priority date: 2011-09-21
Filing date: 2012-09-20
Publication date: 2016-07-14
Anticipated expiration: 2032-09-20
Also published as: AU2012313343A1; WO2013040640A1

Abstract

This invention relates to an anchor assembly (1) for securing a column base (4) to a concrete footing (2). The assembly (1) includes a rod (6) and a housing (14) housing the rod (6) so as to allow a distal end (7) of the rod (6) to pivot about its proximal end relative to the housing (5).

Description

ANCHOR ASSEMBLY

FI ELD OF THE INVENTION

This invention relates to an anchor assembly for securing a column base to a concrete footing, and anchor system including a plurality of said anchor assemblies and a footing including said anchor system. The invention has been developed for an application with metal portal frames and it will be convenient to hereinafter describe the invention with reference to this application. It is to be appreciated however that the invention may have other applications such as with light poles, transmission towers or road signs.

BACKGROUND OF THE INVENTION

The construction industry has appreciated for some time that prefabrication, or at least fabrication off site, is generally a more efficient way of constructing structures. The construction of industrial properties such as factories and warehouses is no exception. These structures will often include a series of metal portal frames that are located at a specified spacing having regard to the loads, spans and section sizes. The frames are fabricated offsite before being transported and erected on site. Erecting the frames will involve the use of a crane(s) to lift the frames off the trucks and locate the frames in position on the site. It will be appreciated that the process of moving the frames off the trucks and into position needs to be accurate and efficient. If time is wasted this will add costs to the construction process and reduce profit margins. The portal frames need a footing to accommodate the loads of the structure. The footing will need to be able to accommodate not only the weight of the structure, but also resist the lift produced by the wind load on the structure. The preferred form of footing is a steel reinforced concrete pad with anchor bolts which are used to tie the frames down to the concrete. An anchor bolt will generally have a bend at a proximal end that is located in the concrete before it has set. The anchor bolt will also have a thread at the distal end to receive a nut. The portal frame will include a column/stanchion/post (hereinafter column) having a base plate that is attached to the bolts. The base plate includes an aperture for each bolt, through which the thread of the bolt extends. A problem can arise when locating each bolt in each aperture of the base plate if there is a misalignment. This can be the case if the bolts move while the concrete is wet. Alternatively the bolts can be misplaced to begin with. The solution often involves cutting the threaded portions off, drilling a hole(s) into the concrete for the new bolt and setting the bolt in the hole with chemical bonding agent such as CHEMSET™. This solution can have its own problems as the hole needs to be free from dust for the bonding agent to adhere to the concrete. Furthermore the strength of the bond is generally not tested, until a catastrophic failure occurs. Still furthermore the solution involves a contract variation which reduces the profit margin. Finally if the misalignment is not noticed until the portal frame is onsite, the crane will need to be retained longer than accounted for, which again reduces the profit margin. It would be desirable to provide an alternate solution to one or more of the above problems.

A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

SUMMARY OF TH E INVENTION

According to one aspect of this invention there is provided an anchor assembly for securing a column base to a concrete footing, the column base having at least one aperture, the anchor assembly having a longitudinal axis and including a rod which extends in the axial direction, the rod including a shaft at least a portion of the shaft is threaded and when in use extends through the aperture in the column base for receiving a nut at a distal end thereof to secure the rod to the column base, a proximal end of the rod being retained so as to prevent movement in an axial direction, a housing extending substantially in the axial direction for housing the rod, the housing and rod being locatable in use in the concrete before the concrete has set so that the housing spaces the rod from the concrete to permit movement of the distal end of the rod in a direction substantially perpendicular to the longitudinal axis once the concrete has set, wherein the rod is free to pivot about its proximal end relative to the housing when said distal end of the rod moves perpendicularly to the longitudinal axis. It is preferred that the anchor assembly include a base that interacts with the proximal end of the rod so as to prevent movement in the axial direction of the rod relative to the housing. The base is preferably formed separately from the housing with an aperture therein through which the shaft extends. It is further preferred that the proximal end of the rod includes a head that is larger than the aperture in the base to prevent the head passing through the aperture. It is further preferred that the base includes a metal plate having a hole through which the shaft extends, whereby the plate extends in a direction substantially perpendicular to the longitudinal axis so as to resist said axial movement. It is still further preferred that the base includes top washer and a bottom washer, each washer having an outer surface that is substantially planar to engage the plate and head of the rod respectively, and each washer having an inner surface on an opposing side to the outer surface, the inner surfaces of the top washer and bottom washer being complementary so as to slide over each other as the distal end of the rod is moved in said perpendicular direction. It is still further preferred that the inner surface of the top washer is bevelled and the inner surface of the bottom washer is curved so as to reduce the surface contact between the top washer and bottom washer. It is still further preferred that the anchor assembly include a further top washer and a further bottom washer which in use is positioned between the nut and column base.

It is preferred that the anchor assembly include a cap for attachment to the proximal end of the housing to cover the proximal end of the rod, the cap being configured relative to the proximal end of the rod to resist rotation of the rod about the longitudinal axis. It is preferred that the cap snap locks onto the housing.

It is preferred that the housing includes a first portion and a second portion which combine to set a length of the housing. It is further preferred that the first portion is adjustable relative to the second portion so as to adjust the length of the housing, the first portion and second portion each having surface features to facilitate secure engagement of the first portion with the second portion, at a select range of lengths for the housing. It is preferred that the housing includes a cylindrical portion that is substantially circular in cross section. It is further preferred that the housing includes a frusto conical portion so that a diameter dimension of the housing adjacent the proximal end is less than a diameter dimension of the housing adjacent the distal end.

It is preferred that the housing includes a flange at the proximal end which extends substantially perpendicular to the longitudinal axis, and at least one web at the proximal end extending in a direction which is substantially perpendicular to the flange.

It is preferred that the housing includes an ingress through which grout can be supplied to occupy a space between the housing and the shaft. It is further preferred that the ingress is positioned adjacent a proximal end of the housing. It is still further preferred that the ingress includes a frangible seal that can be pierced by a grout tube when the assembly is in use.

It is preferred that the anchor assembly include a detachable cover that in use is locatable adjacent the distal end of the shaft for preventing concrete engaging the shaft. It is further preferred that the cover includes a shaft portion which covers the distal end of the shaft, and a skirt portion which extends between the shaft portion and the housing to prevent concrete entering a space between the shaft and the housing. It is still further preferred that the shaft portion is detachable from the skirt portion. It is still further preferred that skirt portion and housing are configured to snap engage.

It is preferred that the housing and cap are formed of a plastics material, the cap being fixable to the housing with a polyolefin bonder. According to another aspect of this invention there is provided an anchor system for securing a column base to a concrete footing, the column base having plate formed with a plurality of apertures, the system including an anchor assembly as herein before defined for each aperture in the column base, and at least one ligature extending between each housing.

It is preferred that each housing includes an attachment means adjacent the proximal end for facilitating attachment of the ligature between each housing. It is further preferred that the attachment means includes a plurality of webs, each web having an aperture to which the ligature is attached.

It is preferred that the anchor system include a plate extending between each housing, each housing including a rib formation adjacent a distal end thereof for interaction with the plate so as to resist movement of the plate in the longitudinal direction relative to the housing. It is further preferred that the plate includes a plurality of apertures, each aperture shaped to receive a distal end of each housing and snap engage with the rib formation. Alternatively the rib formation includes at least one longitudinally extending keyway to align with at least one notch formed in the aperture in the plate so as to allow the housing to lock engage with the plate.

According to another aspect of this invention there is provided a footing for securing a column at a site, the column having base plate formed with a plurality of apertures, the footing including an anchor system as herein before defined, metal reinforcing members positioned to interact with the anchor system, and concrete around the anchor system and reinforcing members.

It is preferred that the concrete is poured on site. It will be convenient to hereinafter describe the invention in greater detail by reference to the attached drawings. The attached drawings are illustrative of one preferred embodiment of the invention, and is not intended that the following description limit the scope of the invention to this one embodiment. Instead the following description is intended to merely be illustrative as to how the invention might be put into effect.

BRI EF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front elevation of a preferred embodiment of an anchor assembly according to one aspect of the invention.

Figure 2 is an exploded isometric view of the anchor assembly from Figure 1 . Figures 3a, 3b and 3c are cross-sectional views of the anchor assembly illustrating adjustability of the rod.

Figure 4 is an isometric view of a preferred embodiment of an anchor system according to another aspect as this invention.

Figure 5 is a cross sectional view of a preferred embodiment of a cover as fitted to the housing and shaft.

Figure 6 is a front elevation view of another preferred embodiment of a proximal end of the housing showing a grouting conduit.

Figures 7a and 7b are plan views of the plate and housing showing an alternate preferred embodiment of the plate keying into the housing. DETAILED DESCRIPTION OF THE DRAWINGS

Referring firstly to Figure 1 which illustrates a preferred embodiment of an anchor assembly 1 located in a concrete footing 2. The anchor assembly 1 is intended for use in securing a column 3, only a base 4 of which is illustrated in Figure 1 , to the concrete footing 2. The anchor assembly 1 includes a housing 5 for housing a rod 6. The housing provides a void within which the rod 6 can be adjusted to locate a distal end 7 of the rod 6 through an aperture in the base 4 of the column 3. The adjustability of the rod 6 relative to the housing 5 will be explained in greater detail with reference to latter illustrations. Figure 1 also illustrates a cap 9 at a proximal end of the housing 5 which can be removed to allow the rod 6 to be inserted into the housing 5. It is preferred that the cap 9 snap locks onto the proximal end of the housing 5, however other means of attaching the cap 9 to the housing 5 are clearly possible. In particular the cap 9 may engage the proximal end of the housing 5 in a friction fit, or alternatively the cap 9 may screw onto the housing 5.

Figure 1 also illustrates a plurality of webs 1 0 adjacent the proximal end of the housing 5. These webs 10 are a preferred form of attachment means for attaching ligatures 1 1 (see Figure 4) between adjacent anchor assemblies 1 . The number, shape and location of these webs 10 may vary from that illustrated depending upon the requirements of the assembly 1 . The interaction of the attachment means 10 with the ligatures 1 1 will be described in greater detail with reference to Figure 4.

The housing 5 illustrated in Figure 1 also includes a series of rib formations 1 2 at locations along the length of the housing 5. These rib formations are intended to accommodate a plate 13 (see Figure 4), and to maintain the position of the plate 13 relative to the housing 5 between the ribs 12. The relevance of the plate 13 will be explained in greater detail with reference to Figure 4. The multitude of ribs 12 allows the location of the plate 1 3 to be variable along the length of the housing 5. The number and location of the ribs 12 may vary from that shown in the illustrations. Figure 1 also illustrates a nut 16 securing the distal end 7 of the rod 6 to column base 4. A pair of washers 22 23 is positioned between the base 4 and the nut 16.

Figure 2 illustrates the preferred form of rod 6, or more specifically the preferred form of the proximal end of the rod 6. Whilst the invention is not limited to a rod as illustrated in Figure 2, the preferred form of rod 6 is a bolt having a head 14 at a proximal end and a shaft 15 extending from the head 14. Whilst the shaft 15 may be threaded along its entire length, it is only necessary that it have the thread at the distal end 7. It can now be appreciated from Figure 2 that the shape of the cap 9 is designed to accommodate the head 14 at the proximal end of the rod 6. Naturally if the proximal end of the rod 6 was of a different shape, the shape of the cap may need to change. It can be appreciated from Figure 3 that it is preferred that the cap 9 accommodate the head 14 in a snap fit, as this prevents the head 14 from spinning when tightening the nut 16. Where the head 14 is too small for the cap 9, an insert may be included to prevent the head 14 from spinning in the cap 9.

Figure 2 also illustrates the preferred form of housing 6 which includes a first portion 1 6 and a second portion 17. It ought to be appreciated that where a relatively short anchor assembly 1 is required, only the first portion 1 7 will be used. Whereas when a longer anchor assembly 1 is required, the second portion 17 is added to the first portion 16. The position of the second portion 17 relative to the first portion 16 is preferably adjustable. This also allows for further variation in the length of the housing 6. Both the first portion 16 and second portion 17 are preferably formed with surface features 1 8 to facilitate a positive engagement of the first portion 1 6 with the second portion 17. Clearly, the number of surface features may vary from the rib and groove illustrated if greater variation in the length is required. Furthermore, the invention is not limited to achieving adjustment of the first portion 16 relative to the second portion 17 by way of the surface features 1 8 illustrated in the figures. Alternate options such as a screw thread arrangement are clearly possible.

The anchor assembly 1 is configured such that the proximal end of the rod 6 is prevented from moving in the axial direction XX. The first portion 1 6 of the housing includes a flange 19 formed at the proximal end thereof. The assembly includes a base 20 which bears against the flange to prevent movement in the axial direction XX. The base 20 includes a plate 21 and a pair of washers 22, 23. The washers 22, 23 interact between the head 14 of the rod 6 and the plate 21 so as to provide uniform load transfer between the head 14 and the plate 21 . It is preferred that the surface configuration of the washers 22, 23 at the proximal end of the housing 5 be the same as that on the washers 22 ,23 between the nut 1 6 and base 4. It can be appreciated from Figure 2 that the bottom washer 22 has an outer surface 24 which is substantially planar and perpendicular to the longitudinal axis XX for engaging the head 14 of the bolt 6. It can be appreciated from Figure 3a that the outer surface 25 of the top washer 23 is also planar and perpendicular to the axis XX. The inner surface of the top washer 23 and bottom washer 22 are the complementing surfaces which allows for pivoting of the proximal end of the rod 6 relative to the proximal end of the housing. 5 This in turn allows for movement of the distal end 7 of the rod 6 in a direction substantially perpendicular to the longitudinal axis XX as can be appreciated from Figures 3b and 3c. It can be appreciated from Figures 3b and 3c that if there is a misalignment between the apertures 8 in the column base 4 of the column and the longitudinal axis XX of the anchor assembly 1 , the distal end 7 of the rod 6 can be adjusted relative to the longitudinal axis XX to allow for the misalignment.

Referring now to Figure 4 which illustrates a preferred embodiment of an anchor system 25 according to another aspect of the invention. In particular the anchor system 25 is a combination of a plurality of anchor assemblies 1 joined at the proximal end of the housing by ligatures 1 1 and at the distal end of the housing 5 by the plate 1 3. The plate 13 is formed with a series of apertures and each aperture snap engages into the rib formation 1 2 formed on the external surface of the housing 5. The plate 13 not only fixes the distal end of the housings 5 but also discourages the egress of wet concrete into the void between the housing 5 and the rod 6. The plate 13 may be formed from metal or plastics material. The ligatures 1 1 help maintain the relative positions of the proximal ends of the housing 5 when locating the anchor system 25 in wet concrete. The ligatures may be formed from a plastics material and include a head formation 26 at each end to locate in the apertures formed in each web 1 0 of the housing 5. The head formation 26 may snap lock into the apertures however this is only preferred. It is preferred that once the column base 4 is located and attached to the anchor system, the void in each housing be filled with a suitable grout.

Whilst Figure 4 illustrates the use of four anchor assemblies 1 to form the anchor system, this number may vary depending on the requirements. Whilst the illustrations show the first portion 16 and the second portion 17 of the housing 5 having a circular cross-section, the invention is not limited to a first portion 16 and second portion 1 7 in this cross-sectional shape only. More specifically as an alternative, the first 16 and second portion 17 may be formed from a hexagonal or octagonal cross-sectional shape.

Figure 5 illustrates a distal end 7 of the rod 6 and housing 5 enclosed by a cover 27. The cover 27 illustrated includes a substantially cylindrical shaft portion 28 covering the shaft 15, and a skirt portion 29 extending between the shaft portion 28 and the housing 5. It is preferred that the shaft portion 28 is formed separately from the skirt portion 29, as illustrated, as this allows the shaft portion 28 to be detached while leaving the skirt portion 29 in place. However the shaft portion 28 could be formed integrally with the skirt portion 29.

Figure 5 also illustrated the housing 5 being formed with a barb 30 for location a recess 31 formed in the skirt portion 29. It is preferred that the cover 27 be formed from an elastomeric material to enable the skirt portion 29 to snap lock onto the housing barb 30, however this is not essential. Alternatively the the skirt portion 29 could be relatively rigid which the housing barb 30 is resiliently deformable.

Figure 6 illustrates an alternate embodiment of a proximal end of the housing 5 and a preferred embodiment of an ingress 32. The ingress 32 illustrated is in the form of a conduit 32 through which grout can be supplied to the proximal end of the housing 5. It is preferred that the conduit 32 extends to just beyond the length of the housing 5 so that the installer can supply the grout once the assembly is fixed in the concrete. The grout occupies a space between the housing 5 and the shaft 15 to hold the shaft 15 in place, once the column base 4 (see fig 1 ) has been attached. Clearly other forms of ingress 32 are possible, and the invention is not limited the conduit 32 form of ingress as illustrated in figure 6. Figures 7a and 7b illustrate a preferred form of engagement between the plate 13 and the housing 5. Figure 7a illustrates the plates 13 being formed with keyway aperture 33 of four notches 34 spaced radially around the aperture 33. The number of notches 34 illustrated is merely preferred and this may vary. The notches 34 are for interaction with the rib formation 1 2 of the housing. In this preferred embodiment the notches 34 on the plate 13 engage a lower rib 12 formation and thereafter the housing 5 is partially rotated to lock the axial position of the plate 13 relative to the housing 5. It is also preferred that the housing 5 and cap 9 be formed from a plastics material. Plastics such as polypropylene or high strength polypropylene have been found appropriate. It is preferred that the strength of the polypropylene by greater than that of the concrete 2 so as to reduce the likelihood that is will collapse when in compression. One advantage of the plastics material is that the length of the housing 5 can be relatively easily cut to size.

It ought to be appreciated from the foregoing description that an anchor assembly 1 according to the invention provides a relatively simple solution for allowing adjustment of the distal end of the rod to allow for misalignment. The use of a housing 5 formed of plastics material, being adjustable in length are particular advantages.

Variations and or additions may be introduced to the anchor assembly and anchor system as hereinbefore described without departing from the spirit or ambit of the invention.

Future patent applications may be filed in Australia or overseas on the basis of or claiming priority from the present application. It is to be understood that features may be added to or omitted from the claims at a later date so as to further define or re-define the invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1 . An anchor assembly for securing a column base to a concrete footing, the column base having at least one aperture, the anchor assembly having a longitudinal axis and including a rod which extends in the axial direction, the rod including a shaft at least a portion of the shaft is threaded and when in use extends through the aperture in the column base for receiving a nut at a distal end thereof to secure the rod to the column base, a proximal end of the rod being retained so as to prevent movement in an axial direction, a housing extending substantially in the axial direction for housing the rod, the housing and rod being locatable in use in the concrete before the concrete has set so that the housing spaces the rod from the concrete to permit movement of the distal end of the rod in a direction substantially perpendicular to the longitudinal axis once the concrete has set, wherein the rod is free to pivot about its proximal end relative to the housing when said distal end of the rod moves perpendicularly to the longitudinal axis.

2. An anchor assembly according to claim 1 including a base that interacts with the proximal end of the rod so as to prevent movement in the axial direction of the rod relative to the housing.

3. An anchor assembly according to claim 2 wherein the base is formed separately from the housing with an aperture therein through which the shaft extends.

4. An anchor assembly according to claim 3 wherein the proximal end of the rod includes a head that is larger than the aperture in the base to prevent the head passing through the aperture.

5. An anchor assembly according to claim 3 or 4 wherein the base includes a metal plate having a hole through which the shaft extends, whereby the plate extends in a direction substantially perpendicular to the longitudinal axis so as to resist said axial movement.

6. An anchor assembly according to claim 5 wherein the base includes top washer and a bottom washer, each washer having an outer surface that is substantially planar to engage the plate and head of the rod respectively, and each washer having an inner surface on an opposing side to the outer surface, the inner surfaces of the top washer and bottom washer being complementary so as to slide over each other as the distal end of the rod is moved in said perpendicular direction.

7. An anchor assembly according to claim 6 wherein the inner surface of the top washer is bevelled and the inner surface of the bottom washer is curved so as to reduce the surface contact between the top washer and bottom washer.

8. An anchor assembly according to claim 6 or 7 including a further top washer and a further bottom washer which in use is positioned between the nut and column base.

9. An anchor assembly according to any one of the preceding claims including a cap for attachment to the proximal end of the housing to cover the proximal end of the rod, the cap being configured relative to the proximal end of the rod to resist rotation of the rod about the longitudinal axis.

10. An anchor assembly according to claim 9 wherein the cap snap locks onto the housing.

1 1 . An anchor assembly according to any one of the preceding claims wherein the housing includes a first portion and a second portion which combine to set a length of the housing.

12. An anchor assembly according to claim 1 1 wherein the first portion is adjustable relative to the second portion so as to adjust the length of the housing, the first portion and second portion each having surface features to facilitate secure engagement of the first portion with the second portion, at a select range of lengths for the housing.

13. An anchor assembly according to any one of the preceding claims wherein the housing includes a cylindrical portion that is substantially circular in cross section.

14. An anchor assembly according to claim 13 wherein the housing includes a frusto conical portion so that a diameter dimension of the housing adjacent the proximal end is less than a diameter dimension of the housing adjacent the distal end.

15. An anchor assembly according to any one of the preceding claims wherein the housing includes a flange at the proximal end which extends substantially perpendicular to the longitudinal axis, and at least one web at the proximal end extending in a direction which is substantially perpendicular to the flange.

16. An anchor assembly according to any one of the preceding claims wherein the housing includes an ingress through which grout can be supplied to occupy a space between the housing and the shaft.

17. An anchor assembly according to claim 16 wherein the ingress is positioned adjacent a proximal end of the housing.

18. An anchor assembly according to claim 16 or 17 wherein the ingress includes a frangible seal that can be pierced by a grout tube when the assembly is in use.

19. An anchor assembly according to any one of the preceding claims including a detachable cover that in use is locatable adjacent the distal end of the shaft for preventing concrete engaging the shaft.

20. An anchor assembly according to claim 1 9 wherein the cover includes a shaft portion which covers the distal end of the shaft, and a skirt portion which extends between the shaft portion and the housing to prevent concrete entering a space between the shaft and the housing.

21 . An anchor assembly according to claim 20 wherein the shaft portion is detachable from the skirt portion.

22. An anchor assembly according to claim 20 or 21 wherein the skirt portion and housing are configured to snap engage.

23. An anchor assembly according to any one of the preceding claims wherein the housing and cap are formed of a plastics material, the cap being fixable to the housing with a polyolefin bonder.

24. An anchor system for securing a column base to a concrete footing, the column base having plate formed with a plurality of apertures, the system including an anchor assembly according to any one of the preceding claims for each aperture in the column base, and at least one ligature extending between each housing.

25. An anchor system according to claim 24 wherein each housing includes an attachment means adjacent the proximal end for facilitating attachment of the ligature between each housing.

26. An anchor system according to claim 25 wherein the attachment means includes a plurality of webs, each web having an aperture to which the ligature is attached.

27. An anchor system according to any one of claims 24 to 26 including a plate extending between each housing, each housing including a rib formation adjacent a distal end thereof for interaction with the plate so as to resist movement of the plate in the longitudinal direction relative to the housing.

28. An anchor system according to claim 27 wherein the plate includes a plurality of apertures, each aperture shaped to receive a distal end of each housing and snap engage with the rib formation.

29. An anchor system according to claim 27 wherein the rib formation includes at least one longitudinally extending keyway to align with at least one notch formed in the aperture in the plate so as to allow the housing to lock engage with the plate.

30. A footing for securing a column at a site, the column having base plate formed with a plurality of apertures, the footing including an anchor system according to any one of claims 24 to 29, metal reinforcing members positioned to interact with the anchor system, and concrete around the anchor system and reinforcing members.

31 . A footing according to claim 30 wherein the concrete is poured on site.