GB2153474A - Wall anchor - Google Patents

Abstract

A wall anchor, particularly for holding a cladding panel (2) against a vertical (or horizontal) wall (1) with an interposed layer of insulating material (3), is disposed at an angle of approximately 45 degrees to the vertical and sloping downwards so that any deterioration of the material (3) results in a downward movement of the panel (2) and extra compression of the material (3). The cross-sectional area of the wall anchor is reduced over at least that part (13) of its length where it leaves the hole (5) in the wall (1) so as to prevent undue bending stress in the event of such downward movement. Two such wall anchors may be joined at their outer ends to supports load from a horizontal wall. <IMAGE>

Description

SPECIFICATION Fixing devices This invention relates to fixing devices such as wall ties and anchor bolts (also collectively referred to herein as "ties"). Wall ties are commonly used to hold inner and outer leaves of a cavity wall at a predetermined distance apart or to mount vertical cladding panels on external walls, while anchor bolts are normally used to secure fittings or apparatus to a horizontal surface such as a floor or ceiling.

Generally speaking it has been customary for such devices to be installed at right angles to the surfaces concerned, i.e. horizontally in the case of wall ties and vertically in the case of anchor bolts.

A disadvantage of such installations is that the forces acting on the fixing device often act substantially co-axially with the device itself. Thus, for example, in the case of a horizontal wall tie or similar device, there may well be a tendency for the supported laminar member to rotate about its lower end and produce a tension on the uppermost wall tie which causes it to move axially and come out of its fixing hole. Even more, of course, in the case of an item suspended from a ceiling, is there a tendency for the vertically-mounted fitting to come out as a result of the direct pull along the axis of the fitting.

A particular problem may arise in the case of heavy cladding panels of, for example, concrete fixed to an external wall by wall ties which maintain them at a fixed distance from the wall to allow for the interposition of a layer of insulation material such as polystyrene. Should the latter deteriorate or be destroyed, there will be a risk of one or more panels falling as a result of severe bending stress on the wall ties.

According to one aspect of the invention, there is provided a fixing device for securing a member to a substantially vertical wall, comprising a tie adapted at one end to be retained in a hole in the wall and provided at the other end with means to secure it to the member, the axis of the tie being disposed at an angle to the wall deviating significantly from a right angle.

According to another aspect, there is provided a fixing device for securing a member to a substantially vertical wall with the interposition of a layer of compressible material, comprising a tie adapted at one end to be retained in a hole in the wall and provided at the other end with means to secure it to the member, the axis of the tie being disposed at an angle to the wall deviating significantly from a right angle, the tie sloping downwardly from the wall to the member.

According to a further aspect, there is provided a fixing device for securing a member to a substantially horizontal surface such as a ceiling or floor and comprising at least two ties each adapted at one end to be retained in a hole in the surface and provided at the other end with means to be secured to the member, the axis of at least one tie being disposed at an angle to the surface deviating significantly from a right angle.

Various embodiments of the invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which; Figure 1 shows a tie for securing a cladding panel to a vertical wall, Figure 2 shows a second tie for the same purpose, and Figure 3 shows an arrangement of ties for securing a member to a ceiling.

Referring to Figure 1, there is shown a wall 1, a cladding panel 2, and an interposed layer 3, approximately 1 inch thick, of an insulating material such as polystyrene. The assembly is held in the position shown by at least four ties of which only one is shown at 4. The inner end of this tie is retained in a blind hole 5 by means of a sleeve 6 which can be expanded in the hole by rotating the threaded end 7 of the tie inside a nut 8 which is adapted to be locked in the hole against rotation.

The sleeve 6 could be of a readily deformable metal or of plastics material as is well known in the art. The sleeve 6 is expanded by rotating the tie from the threaded external end 9 before the latter is fixed to the panel 2 by means of a nut 10 and washer 11 in a countersunk extension of the hole 12 in the panel. Alternatively the hole 12 could continue to the outside of the panel and a wedgesection washer be substituted for the plane washer 11.

It will be noted that, although the diameter of the inner end 7 of the tie approximates to the diameter of the hole in the wall, the diameter of the tie is significantly reduced over the portion 13 whose length includes the point where the tie leaves the hole 5 in the wall 1. By this means, any bending stress on the tie at the point where it leaves the hole is reduced or eliminated, should the panel 2 drop as a result of deterioration of the layer 3.

It will be appreciated that, with the panel held by a group of ties arranged at the angle shown (approximately 45 degrees), the layer 3 is in compression over its entire area and this gives great strength and rigidity to the structure.

In the alternative embodiment shown in Figure 2, the inner end 7 of the tie is of full diameter until it leaves the hole 5 but the remainder of the tie is joined to it by an articulation 14 such as a universal joint. This is another way of reducing bending stress if the panel 2 drops.

A somewhat similar arrangement could be used to mount the cladding or similar member directly on the wall without the layer 3 but in this case, it would be advisable to have the tie inclined in the opposite direction so that it slopes upwards from the wall outwards.

A fitting in which the tie was arranged to slope downwards as shown in Figures 1 and 2 could be used to tie scaffolding to a wall or mount a dispenser, wash basin or other item on a wall.

Again, in the case of a wall-tie for keeping cavity walls at the correct distance apart, this could be mounted at the angle shown in Figures 1 and 2, and the downward slope of the tie would prevent moisture from running along the tie from the outside.

So far it has been assumed that, where the member concerned has been secured by more than one tie all the latter have had a parallel slope.

Advantages can be had if two or more ties have different slopes, particularly where a horizontal surface such as a floor or ceiling is involved rather than a vertical surface such as a wall.

Items such as machines are usually bolted to a floor by vertically mounted ties in the form of anchor bolts. According to one embodiment (not shown) at least one of these anchor bolts is arranged at an angle to the others to give greater stability and greater resistance to shear stresses.

Preferably, in the case of say four anchor bolts, these are arranged in parallel pairs each pair being on an axis which converges with the axis of the corresponding bolt in the other pair.

A somewhat similar arrangement is particularly valuable for fixing a member to a ceiling or the like where the downward pull of the suspended member would tend to pull the ties out of their holes if their axes were vertical as usual.

A particularly advantageous fixing arrangement for suspended fittings is shown in Figure 3. In this case two ties 15 and 16 are held in drilled holes in a concrete ceiling 17 by conventional expansion members 18 and 19 as already described. At their lower ends, the ties not only converge but meet and it is at this point where they are both joined to the suspended member indicated simply as a weight W. Additionally the ties 15 and 16 are joined immediately below the ceiling 17 by a cross member 20. This gives an extremely rigid suspension capable of withstanding even earthquake shocks which open the holes in the ceiling. The whole arrangement would drop to some extent but would not fall.

Claims (10)

1. A fixing device for securing a member to a substantially vertical wall, comprising a tie adapted at one end to be retained in a hole in the wall and provided at the other end with means to secure it to the member, the axis of the tie being disposed at an angle to the wall deviating significantly from a right angle.

2. A fixing device for securing a member to a substantially vertical wall with the interposition of a layer of compressible material, comprising a tie adapted at one end to be retained in a hole in the wall and provided at the other end with means to secure it to the member, the axis of the tie being disposed at an angle to the wall deviating significantly from a right angle, the tie sloping downwardly from the wall to the member.

3. A fixing device as claimed in claim 2 in which the angle is approximately 45 degrees.

4. A fixing device as claimed in claim 2 or 3, in which the means for retaining the one end of the tie in the hole in the wall comprises a sleeve of a material which can be expanded in the hole by means operable from theother end of the tie.

5. A fixing device as claimed in any one of claims 2 to 4, in which the diameter of the tie approximates at the one end to the diameter of the hole in the wall in which it is retained, the diameter of the tie being significantly reduced over that at least portion of its length which includes the point where the tie leaves the hole in the wall.

6. A fixing device as claimed in any one of claims 2 to 4 in which the tie is provided with an articulation such as a universal joint just outside the point where it leaves the hole in the wall.

7. A fixing device for securing a member to a substantially horizontal surface such as a ceiling or floor and comprising at least two ties each adapted at one end to be retained in a hole in the surface and provided at the other end with means to be secured to the member, the axis of at least one tie being disposed at an angle to the surface deviating significantly from a right angle.

8. A fixing device as claimed in claim 7 in which the axes of at least two of the ties are convergent.

9. A fixing device as claimed in claim 7 or 8 in which the angle is approximately 45 degrees.

10. A fixing device substantially as described with reference to the accompanying drawings.