EP2004920A1

EP2004920A1 - Anchoring device

Info

Publication number: EP2004920A1
Application number: EP07712902A
Authority: EP
Inventors: Alec Trotter
Original assignee: GUARD UK Ltd K; K Guard UK Ltd
Current assignee: K Guard International Ltd
Priority date: 2006-03-15
Filing date: 2007-03-14
Publication date: 2008-12-24
Also published as: GB0605218D0; GB2436133A; GB2436133B; WO2007104993A1

Abstract

The invention provides an anchoring device comprising a solid body (102) having a wider end (112), a narrower end (110) and a connecting side wall therebetween, the side wall being formed with a plurality of longitudinal ridges (106, 108) that decrease in radial dimension in the direction of the narrower end of the solid body; and the solid body being provided with a central passageway (122) extending axially from the narrower end, the central passageway (122) having a thread for receiving a threaded anchoring post or bolt.

Description

ANCHORING DEVICE

This invention relates to an anchoring device for anchoring an object to a substrate such as a wall, ceiling or floor. More particularly, the invention provides an anchoring device for casting in a reinforced concrete surface to provide a means for anchoring an object to the reinforced concrete surface.

Background of the Invention

Various types of anchoring devices are known for use in reinforced concrete surfaces such as floors and ceilings, some of which are put in place before pouring of the concrete and some of which are installed after the concrete has cured. Examples of the latter type are expanding bolts that are installed by drilling a hole in a concrete surface just large enough to accommodate the bolt and then hammering a plunger into the bolt to spread the lower part of the bolt so that it grips the wall of the hole. This type of anchoring device suffers from a number of disadvantages. Firstly, the need to drill into the reinforced concrete means that there is a substantial risk that the drill bit may sever or at least weaken one of the tensioned reinforcing rods within the concrete. Moreover, in post-tensioned slabs, there is a risk of damaging the reinforcement tension tendons. Furthermore, there is a very high probability that the hole will be not be drilled so that it is perpendicular to the surface but may instead be at an angle. This may be caused by, for example, aggregate in the concrete or the reinforcing rods diverting the drill bit away from the perpendicular. A further problem is that if the anchoring device is being installed near to the edge of a concrete slab, for example at the edge of a concrete floor so that barriers can be erected at the edge of the floor, there is a chance that the impact of a hammer on the bolt may cause the edge of the slab to break away.

An alternative anchoring device for reinforced concrete surfaces makes use of the reinforcing rods in the concrete to hold the anchoring device in place. Such a device comprises a tubular metal body which is internally threaded at one end to receive a bolt or similar threaded fastening means and is flattened at the other end. The flattened end has a hole drilled or punched through it. The anchoring device is secured to the reinforcing rods before the concrete is poured, either by threading a reinforcing rod through the hole in the flattened end of the device or by tying the device to a reinforcing rod by, for example, wire. Once the anchoring device(s) is in place, the concrete can then be poured. However, this type of anchoring device also suffers from several problems. Firstly, the installation of the device can be time consuming and, secondly, the relative ease with the device can swivel about the reinforcing rod means that it is difficult to ensure that the threaded part of the device is perpendicular to the surface of the concrete. Consequently, when objects such as the posts for railings or barriers are connected to the anchor, they may not be correctly aligned.

Thus, there remains a need for an anchoring device that can be installed in a concrete substrate such as a floor or ceiling without damaging the concrete and which can be installed accurately, readily and easily so that a bolt or anchoring post, when connected to the anchoring device, is perpendicular to the surface.

Summary of the Invention

In a first aspect, the invention provides an anchoring device comprising a solid body having a wider end, a narrower end and a connecting side wall therebetween, the side wall being formed with a plurality of longitudinal ridges that decrease in radial dimension in the direction of the narrower end of the solid body; and the solid body being provided with a central passageway extending axially from the narrower end, the central passageway having a thread for receiving a threaded anchoring post or bolt.

Particular and preferred aspects and embodiments of the invention are as described below and as set out in the claims appended hereto.

The anchoring device of the invention is shaped so that it can be pushed into wet concrete before it cures, but after the initial screeding has taken place. The shape of the anchoring device allows the wet concrete to flow around the body of the anchoring device as it is pushed in, thereby holding the device firmly in place. The longitudinal ridges prevent retraction of the device from the concrete. In one embodiment, the solid body comprises a substantially circular cylindrical portion from which the longitudinal ridges extend. The circular cylindrical shape facilitates the flow of concrete around the solid body.

The solid body is typically formed from a plastics material such as polyamide (e.g. "Nylon") and may be formed, for example by injection moulding or by machining from plastics bar or rod. The lightweight nature of the anchoring device ensures that sinking / displacement of the anchoring device cannot occur. The central passageway may be formed during a moulding process or may be drilled out after moulding a basic body shape. The plastics material may be reinforced with reinforcing fibres such as glass fibres for extra strength.

The central passageway opens at the narrower end of the solid body and extends axially away therefrom. The central passageway can extend through the entire length of the solid body or for only part of the length of the body. In the latter case, which is preferred, the central passageway is a blind passage.

The central passageway contains a thread, either cut directly into the wall of the passageway, or provided by means of a threaded portion formed from another material such as metal and which is inserted or embedded (e.g. by moulding) in the central passageway.

In one embodiment, the anchoring device is configured such that the thread is at least partially provided by a threaded metal sleeve which is disposed within the central passageway. The threaded metal sleeve is typically embedded in a wall of the central passageway. The threaded metal sleeve can extend along the entire length of the central passageway or along only a portion of the central passageway. In one embodiment, the threaded metal sleeve extends along only a portion of the central passageway. In this embodiment, the central passageway can be threaded to one or both sides of the metal sleeve. More particularly, the central passageway can be threaded either side of the metal sleeve, the metal sleeve being embedded so that the thread to either side of the metal sleeve is flush with the thread of the metal sleeve. Typically there are three to five longitudinal ridges extending from the side surface of the solid body, although there may in principle be fewer or more. Preferably, there are four longitudinal ridges.

It is preferred that the ridges are equidistantly spaced round the side surface. Therefore, when there are four ridges, the centres of the ridges will be 90° apart.

The anchoring device of the invention may have a saddle formation at the wider end of the solid body, the saddle formation being configured so that in use it can sit about a reinforcing bar or rod in a reinforced concrete substrate. The saddle portion typically has a channel formed in an undersurface thereof, the channel being of a size such that it can accommodate the reinforcing bar or rod in the concrete. The saddle portion provides a means of locating the anchoring device more accurately in the concrete while it is curing and also assists in maintaining the correct distance to the surface of the concrete.

In another embodiment, the anchoring device has a solid body which is of substantially frustoconical form having a wider end, a narrower end and a connecting side surface linking the wider and narrower ends; the side surface having a plurality of channels therein extending from the wider end towards the narrower end, the channels tapering in the direction of the narrower end; and wherein the longitudinal ridges are constituted by regions of the side surface between adjacent channels.

In order to facilitate flow of concrete around the frustoconical solid body as it is pushed into the wet concrete, the channels are preferably of arcuate cross section.

The channels taper in the direction of the narrower end; i.e. the channels decrease either in width or in depth or in both width and depth towards the narrower end. Preferably the channels decrease in both width and depth towards the narrow end.

The maximum depth of the channel, at the wider end of the frustoconical solid body, is typically greater than one quarter of the radius of the wider end. The floor of each channel, i.e. the deepest part of the channel, can be substantially parallel to the longitudinal axis of the frustoconical solid body. This arrangement further assists the flow of concrete around the frustoconical solid body as it is pushed into wet concrete.

In a particularly preferred embodiment, the radial distance between the longitudinal axis of the frustoconical solid body and the deepest part of each channel at the wider end corresponds substantially to the radius of the narrower end of the solid body. In this embodiment, the solid body can be viewed as a cylinder upon which are superimposed radially extending ridges, the ridges corresponding to the regions of the body between the channels .

In order to prevent concrete from entering the central passageway and clogging the thread while the anchoring device is being pushed into the wet concrete, a removable cap is preferably provided for concealing the central passageway during installation of the anchoring device. The removable cap can be removed once the concrete has set.

In another aspect, the invention provides a concrete substrate having embedded therein an anchoring device as defined herein, wherein the solid body is buried within the concrete substrate so that only the narrower end of the solid body or, when present, the removable cap, are visible.

The concrete substrate may be a reinforced concrete substrate, e.g. formed from concrete reinforced with metal (e.g. steel) reinforcing rods.

The invention further provides a method of forming a concrete substrate having embedded therein one or more anchoring devices as defined herein, which method comprises pushing each anchoring device into the surface of the concrete substrate whilst it is still wet and before the concrete has set so that all or the greater part of each anchoring device is submerged below the surface of the concrete, and thereafter allowing the concrete to set.

The anchoring devices of the invention can be used for securing temporary safety barriers to concrete floors (e.g. elevated concrete floors) during the construction or renovation of buildings. The safety barriers can be personnel security barriers of the type described in our earlier patent application GB2398100.

Accordingly, in another aspect, the invention provides a safety barrier assembly for a concrete floor, the safety barrier assembly comprising a plurality of anchoring devices as defined herein set into the concrete floor and one or more safety barriers secured to the floor by means of threaded anchoring posts or bolts connected to the anchoring devices.

The invention will now be illustrated in more detail (but not limited) by reference to the specific embodiment shown in the drawings

Brief Description of the Drawings

Figure 1 is a side view of an anchoring device according to one embodiment of the invention.

Figure 2 is a view from direction I of the anchoring device in Figure 1.

Figure 3 is a view from direction II of the anchoring device of Figure 1.

Figure 4 is a sectional view along line III-III in Figure 2 but additionally showing a removable cap.

Figure 5 is a sectional view showing the anchoring device of Figures 1 to 4 anchored in a concrete surface.

Figure 6 is a schematic illustration showing a barrier anchored to a concrete surface by anchoring devices of the invention.

Figure 7 is a perspective view of an anchoring device according to a second embodiment of the invention.

Figure 8 is a view from one side of the anchoring device of Figure 7.

Figure 9 is a view from direction Dl of the embodiment of Figure 7.

Figure 10 is view from direction D2 of the embodiment of Figure 9. Figure 11 is a view from direction D3 of the embodiment of Figure 9.

Figure 12 is a section along line A - A of Figure 10.

Figure 13 is an isometric view of a section as shown in Figure 12.

Detailed Description of the Invention

The invention will now be illustrated but not limited by reference to the particular embodiments shown in the accompanying drawings.

As shown in Figure 1, an anchoring device according to one embodiment of the invention comprises a substantially frustoconical solid body 2 having a wider end 4, a narrower end 6 and a side surface 8 linking the wider 4 and narrower 6 ends. The side surface 8 has a plurality (in this case four) of channels 10 therein that extend from the wider end 4 to the narrower end 6. The channels 10 are of arcuate cross section and taper in the direction of the narrower end 6, with both the depth and the width of the channels decreasing with distance towards the narrower end 6. The deepest part of the channel 10 at the wider end 4 is denoted by the letter D and it can be seen from Figures 2 and 3 that the radial distance r¹ between D and the central axis of the solid body 2 is equal to the radius r² of the solid body 2 at the narrower end. As can be seen more clearly from Figure 4, the floor 12 of each channel is substantially parallel to the central axis A of the solid body 2. Thus, in an alternative geometric description, the solid body may be viewed as a circular cylinder upon which are superimposed a series of radially extending ridges 14, the ridges being constituted by the regions of the solid body between the channels.10.

The solid body 2 is provided with a central passageway 16 which has an internal thread 18 for receiving a threaded anchoring socket, post or bolt. The central passageway 16 is a blind passageway that extends for about three fifths of the length of the solid body. The passageway can either be formed during the moulding of the solid body or formed by drilling after the body has been moulded. The thread is typically cut in a separate operation after the solid body has been formed by moulding. The thread 18 in the embodiment shown in Figure 4 is cut directly into the plastics material of the solid body 2. However, as an alternative, a threaded metal insert can be set into the passageway 16. The threaded metal insert may have an internal thread for receiving an anchoring socket, post or bolt and an external self tapping thread for cutting into the wall of the passageway 16 to secure the insert in place. The threaded metal insert enables the anchoring device to withstand greater pull-out loads than might be the case where the thread is cut directly into the solid body.

In use, a removable cap 20 is fitted to the solid body 2 by means of threaded spigot 22 and the anchoring device is pushed into a layer of wet uncured concrete C reinforced with reinforcing rods R. As the anchoring device is pushed into the concrete, the concrete flows or slides into and along the channels 10 so that, when it has been fully pushed into the concrete, only the cap 20 is visible. The smooth arcuate profile of the channels 10 and the fact that the floors of the channels are substantially parallel with the longitudinal axis A of the solid body 2 together ensure that the concrete slides smoothly over the surface of the solid body 2 with only minimal disturbance to the surrounding areas of concrete.

Once the concrete has cured, the cap 20 can be removed and a bolt / socket or anchoring post of a fixture such as a barrier can be screwed to the anchoring device. Figure 6 shows schematically the securing of a barrier B to a concrete floor F by means of a pair of threaded posts connected to a pair of anchoring devices 1 of the invention.

An anchoring device according to a second embodiment of the invention is shown in Figures 7 to 13.

In this embodiment, the anchoring device comprises a solid body 102, which has a substantially circular cylindrical portion 104 from which extend longitudinal ridges 106, 108. The longitudinal ridges decrease in radial dimension in the direction of the narrower end 110 of the solid body.

At the wider end 112 of the solid body, is a saddle formation 114 which has a channel 116 moulded into the under surface thereof. A total of four longitudinal ridges are provided, two shorter ridges 108 extending between the narrow end and an upper surface of the saddle formation 114, and a pair of longer ridges 106 that extend from the narrower end 110 to a flange 118 at the wider end 112 of the solid body.

The longitudinal ridges in this embodiment are much narrower than those of embodiment 1, and take the form of fins that are of substantially uniform thickness along their length. The outer edges 120, 122 of the longitudinal ridges can be radiused or substantially flat.

The solid body 102 has a central passageway 122, which is threaded along its entire length. Set into the wall 124 of the central passageway 122 is an embedded metal sleeve 126 which itself is threaded on its inner and outer surfaces. The thread on the inner surface of the metal sleeve 126 is aligned with the thread extending along the remainder of the central passageway 122.

As with the anchoring device of embodiment 1, the anchoring device shown in Figures 7 to 13 is formed from a moulded plastics material, and in particular a moulded polyamide such as 'nylon'.

The generally circular cylindrical shape of the upper part of the solid body facilitates the flow of concrete around the anchoring device as it is pushed into the concrete. In the event that the anchoring device encounters a reinforcing rod or bar within the concrete, the anchoring device can be rotated so that the channel 116 of the saddle formation 114 sits about the ring forcing rod or bar. Locating the anchoring device on a reinforcing rod or bar allows more accurate positioning of the anchoring device and this, together with the lightweight nature of the materials from which the anchoring device is formed serve to prevent the anchoring device from sinking too far into the concrete before it cures.

As with the embodiment of Figures 1 to 6, a removable cap can be provided for closing the central passageway during installation, thereby to prevent fouling of the thread. Once the concrete has cured, the cap can be removed. The embodiments illustrated in Figures 1 to 13 represent merely two ways of putting the invention into effect and it will readily be apparent that numerous modifications and alterations may be made to the specific embodiments shown without departing from the principles underlying the invention. All such modifications and alterations are intended to be embraced by this application.

Claims

1. An anchoring device comprising a solid body having a wider end, a narrower end and a connecting side wall therebetween, the side wall being formed with a plurality of longitudinal ridges that decrease in radial dimension in the direction of the narrower end of the solid body; and the solid body being provided with a central passageway extending axially from the narrower end, the central passageway having a thread for receiving a threaded anchoring post or bolt.

2. An anchoring device according to claim 1 wherein the longitudinal ridges are spaced at regular intervals around the side wall of the solid body.

3. An anchoring device according to any one of the preceding claims wherein the thread is at least partially provided by a threaded metal sleeve which is disposed within the central passageway.

4. An anchoring device according to claim 3 wherein the threaded metal sleeve is embedded in a wall of the central passageway

5. An anchoring device according to claim 3 or claim 4 wherein the threaded metal sleeve extends along only a portion of the central passageway.

6. An anchoring device according to claim 5 wherein the central passageway is threaded either side of the metal sleeve, the metal sleeve being embedded so that the thread to either side of the metal sleeve is flush with the thread of the metal sleeve.

7. An anchoring device according to any one of the preceding claims wherein the central passageway is a blind passage.

8. An anchoring device according to any one of the preceding claims wherein there are three to five longitudinal ridges.

9. An anchoring device according to claim 8 wherein there are four equidistantly spaced longitudinal ridges.

10. An anchoring device according to any one of the preceding claims wherein the solid body comprises a substantially circular cylindrical portion from which the longitudinal ridges extend.

11. An anchoring device according to any one of the preceding claims having a saddle formation at the wider end of the solid body, the saddle formation being configured so that in use it can sit about a reinforcing bar or rod.

12. An anchoring device according to anyone of claims 1 to 9 and 11 wherein the solid body is of substantially frustoconical form having a wider end, a narrower end and a connecting side surface linking the wider and narrower ends; the side surface having a plurality of channels therein extending from the wider end towards the narrower end, the channels tapering in the direction of the narrower end; and wherein the longitudinal ridges are constituted by regions of the side surface between adjacent channels..

13. An anchoring device according to claim 12 wherein the channels are of arcuate cross section.

14. An anchoring device according to claim 12 or claim 13 wherein the channels decrease in width and depth towards the narrow end.

15. An anchoring device according to claim 14 wherein each channel has a floor which is substantially parallel to the longitudinal axis of the frustoconical solid body.

16. An anchoring device according to any one of claims 12 to 15 wherein the radial distance between the longitudinal axis of the frustoconical solid body and the deepest part of each channel at the wider end corresponds substantially to the radius of the narrower end of the solid body.

17. An anchoring device according to any one of claims 12 to 16 wherein the maximum depth of the channel, at the wider end surface, is greater than one quarter of the radius of the wider end surface.

18. An anchoring device according to any one of the preceding claims wherein the substantially frustoconical solid body is formed from a plastics material.

19. An anchoring device according to claim 11 wherein the plastics material is a polyamide such as "Nylon".

20. An anchoring device according to claim 18 or claim 19 wherein the plastics material is reinforced by fibres such as glass fibres.

21. An anchoring device according to any one of the preceding claims wherein a removable cap is provided for concealing the central passageway during installation of the anchoring device.

22. An anchoring device substantially as described herein with reference to the accompanying drawings.

23. A concrete substrate having embedded therein an anchoring device as defined in any one of the preceding claims such that the solid body is buried within the concrete substrate so that only the narrower end of the solid body or, when present, the removable cap, are visible.

24. A concrete substrate according to claim 23 which is a reinforced concrete substrate.

25. A method of forming a concrete substrate having embedded therein one or more anchoring devices as defined in any one of claims 1 to 22, which method comprises pushing each anchoring device into the surface of the concrete substrate whilst it is still wet and before the concrete has set so that all or the greater part of each anchoring device is submerged below the surface of the concrete, and thereafter allowing the concrete to set.

26. A safety barrier assembly for a concrete floor, the safety barrier assembly comprising a plurality of anchoring devices as defined in any one of claims

1 to 22 set into the concrete floor and one or more safety barriers secured to the floor by means of threaded anchoring posts or bolts connected to the anchoring devices.