GB2261693A

GB2261693A - Wall tie device

Info

Publication number: GB2261693A
Application number: GB9224192A
Authority: GB
Inventors: Keith Oates
Original assignee: Kinetic Engineering & Design L
Current assignee: Kinetic Engineering & Design L
Priority date: 1991-11-19
Filing date: 1992-11-18
Publication date: 1993-05-26
Anticipated expiration: 2012-11-18
Also published as: GB9224192D0; GB2261693B; GB9124519D0

Abstract

A tie device for use in bracing together two spaced apart members 10, 12 at a fixed spacing. So that the device can be very easy to use and be effective in breeze block walls 10, it includes a length of tube (18) at least one end of which has longitudinal slits, at least one ferrule (24) embracing the tube and plug means (28) for radially expanding the tube. As tube (18) is driven in by punch (32) tube (18) expands to be trapped between plug (28) and outer sleeve (26), so becoming fixed in wall (10). The other end may then be fixed in wall (12) by driving in a similar plug to (28). <IMAGE>

Description

Tie device The invention relates to a tie device for use in bracing together two spaced apart members at a fixed spacing, in particular to a wall tie device for use in bracing together the inner and outer leaves of a cavity wall the original bracing of which is at least suspect.

The cavity walls of a great many houses, flats and office buildings are known to be unsafe because of the fact that their original wall ties are gradually rusting away. The original wall ties may have been made, for example, of galvanised ferrous metal but it has been found that the cement mortar which has been used in recent years has seriously attacked them, in some cases corroding them away completely where they extend between the inner and outer leaves of the building concerned, due to mortar having fallen onto them during the construction of the building.

Various methods have been adopted in an attempt to cure the problem. For example, holes have been drilled through one leaf of a cavity wall to extend into the other leaf and screwthreaded rods and the like with expandable fittings have been passed through and into such holes to brace the inner and outer leaves of the wall together. However, for various reasons such remedies have not been wholly successful. For example, the inner leaves of cavity walls of buildings are frequently made of so-called breeze block materials which are not suitable for resisting concentrated heavy loads.

Consequently, mechanical fixing arrangements cannot be wholly relied upon in such materials.

Mechanical fixing arrangements, that is to say, for example, fixings which incorporate taper plugs or sleeves which must be displaced by means of screwthreaded rods or the like are time consuming to use. They frequently require the drilling of different diameter holes in the inner and outer leaves of the building. A further difficulty is that the fitting of certain kinds of mechanical fixing arrangements can result in a residual tension in the fitting, this imposing considerable cumulative loads on the leaves of a cavity wall, so much so that the leaves can be caused to bow inwards towards each other.In addition to this, it is known that differential expansion of the inner and outer leaves of cavity walls in multistorey buildings can result in substantial movements of the upper courses of bricks and blocks which has not been allowed for when using the screwthreaded rods and the like referred to above.

The invention has for its object to provide a wall tie which will at least alleviate some of these difficulties.

According to one aspect of the invention, there is provided a method of bracing together two spaced apart members at a fixed spacing, the method including the steps of drilling a hole through one member and into the other; inserting a length of tube through the hole in said one member to locate an inner end of the tube in the hole in said other member and an outer end in said one member; securing the inner end of said tube in the hole in said other member; and subsequently driving a tapered plug into the outer end of the tube to cause said tube to expand into gripping engagement with said one member. A preliminary step in the method just referred to may comprise the slitting of the walls of the length of tube at least along a portion of the length that is to be its outer end.

A further preliminary step may comprise the fitting of a resilient sleeve on the length of tube at least at what is to be its outer end.

The method may include the step of entering a length of rod into the tube to act as a fixed abutment member, inserting an expander sleeve into the outer end of the length of tube to abut against the rod, and driving a tapered plug into the expander sleeve to force it radially outwards and to expand the outer end of the length of tube.

The inner end of the length of tube may be secured in the hole in said other member by pushfitting a tapered plug in what is to be its inner end before the tube is inserted into the hole in the two members, and subsequently driving the tube into the hole so that its inner end has been forded onto the tapered plug as the latter has seated against the bottom of the hole, or by fitting a tapered plug and an expander sleeve at what is to be the inner end of said tube and using a length of rod entered into said tube to drive the expander sleeve along the tapered plug, the inner end of the tube thus having been expanded to become wedged in the hole. A preliminary step may comprise the fitting of a resilient sleeve on the length of tube at what is to be its inner end.

Alternatively, the inner end of the length of tube may be secured in the hole in said other member by forcing an adhesive through said length of tube to introduce the adhesive along the exterior of the tube and adhere the tube within the drilled hole in said other member within which it has been located.

According to another aspect of the invention, there is provided a tie device for bracing together two spaced apart members at a fixed spacing, the tie device including a length of tube at least one end of which has at least one longitudinal slit, at least one ferrule embracing said tube and plug means for radially expanding the tube at least at the end thereof which has the at least one longitudinal slit. The tie device may also include at least one synthetic plastics sleeve for fitment on an end length of the tube which has the longitudinal slits.

The plug means for radially expanding the tube may be constituted by a headed tapered plug and an expander sleeve which co-operate in the slitted end length of the tube. The device may include a length of rod which can be entered into the length of tube to abut against the end of the expander sleeve.

The tapered surface of the or each tapered plug may be stepped or serrated to bite into the surfaces of the associated sleeve.

According to a still further aspect of the invention, there is provided means for testing the grip of a tie device as described above in one of the two spaced apart members which are to be braced together, these means being constituted by a tool having a sleeve, a pull rod with a tapered inner end portion terminating in a circumferential flange, and a collar having screwthreaded engagement on a screwthreaded outer end portion of said rod.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which:- Figure 1 is an exploded view of a wall tie device embodying the invention, Figures 2 to 5 are sectional views through a cavity wall which illustrate successive steps in bracing together the inner and outer leaves by the wall tie device of Figure 1, Figures 6 and 7 are views similar to Figures 2 to 5 which illustrate successive steps in using a modified wall tie device embodying the invention, Figures 8 and 9 are views which illustrate further possible modifications, and Figures 10 and 11 are views which illustrate the use of a testing tool when testing the grip of a wall tie device embodying the invention in the inner leaf of a cavity wall.

Referring now to Figure 1 of the drawings, a wall tie device, generally indicated 10, includes a length of synthetic plastics tube 18 such as glass fibre or carbon fibre tube. The tube has a number of longitudinal slits 20 at its opposite ends as shown in Figure 1. A ring element 22 embraces the tube at a point substantially midway along its length, and a pair of metal ferrules 24 embrace the tube some distance from its opposite ends, that is to say in the region to which the slits 20 extend from its opposite ends, all these being for purposes which will presently be explained.

Synthetic plastics sleeves 26 are provided for fitment on the opposite end lengths of the tube 18 to abut against the metal ferrules 24. At what is to be an inner end of the device, the tube 18 is provided with a tapered plug 28. A further tapered plug 30 is shown in Figure 1 to form a part of the tie device, but this is not entered into the tube 18 until the tube has been entered into the drilled holes in the leaves of the cavity wall.

Referring now to Figure 2 of the drawings, the cavity wall there illustrated in section has inner and outer leaves 10 and 12 which are to be braced together by a wall tie device as just described.

(For the sake of illustration, the inner leaf of the wall is shown to be built of breeze blocks and the outer leaf of stone. The present invention can be embodied in wall tie devices, such as the illustrated example, which are particularly well suited to this kind of cavity wall construction but it is not wholly restricted to such embodiments).

A preliminary operation in readiness for the fitment of the wall tie device involves the drilling of a hole 16 through the outer leaf of the wall and into the inner leaf, the hole diameter in the inner and outer leaves being the same.

In Figure 2 the tube is shown to have been entered into the hole 16 until the wider end of the tapered plug 28 has seated against the bottom of the hole in the inner leaf. Prior to the insertion of the tube into the hole 16, the plug 28 is only lightly push fitted into the bore of the tube so that the plastics sleeve 26 is a sliding fit in the hole 16. At this stage, as indicated chaindotted in Figure 2, a punch 32 is used to drive the tube 18 further into the hole 16 so that its inner end is forced onto the tapered plug 28, that end of the tube thus being expanded to become wedged in the hole 16 in the breeze block, as shown in Figure 3.

A final operation in the fixing of the tie device in position is shown in Figure 4 to comprise the driving of the tapered plug 30 into the outer end of the tube 18, conveniently by using the same punch as before, this causing the outer end portion of said tube to expand to become tightly wedged in the stonework of the outer leaf by forcing the plastics sleeve 26 at that end of the device radially outwards.

It will be understood that the ring element 22, which on the installed tie device is located substantially in the middle of the wall cavity, is provided to prevent any water coursing down the inside of the outer leaf from tracking across the cavity. The metal ferrules 24 prevent the slits 20 from progressing along the length of tube which would make the ring element 22 ineffective in preventing such tracking of water.

In Figure 5, an outer end portion of the hole in the outer leaf of the wall is shown to have been filled with mortar after the tie device has been fixed in position.

Thus there is provided a method of and means for bracing together the inner and outer leaves of a cavity wall which is simple to use and can be installed in a minimum of time due to the fact that the holes in the inner and outer leaves are of the same diameter and due also to the fact that no screwthreading action is involved. When installed, the device is neither in compression nor in tension so that it imposes no load which might cause either one of the leaves of the cavity wall to bow.

Referring now to Figures 6 and 7, the wall tie device there illustrated is similar to that illustrated in Figure 1 in the sense that it includes a length of synthetics plastics tube 18 with slits 20 at its opposite ends and in that it has synthetic plastics sleeves 26 and metal ferrules 24 on its opposite ends. However, in this case, a tapered plug 19, at what is to be an inner end of the device, is a headed plug, the tapered part of the plug being somewhat smaller than before so that the end of the tube can abut against the head of the plug in the loosely assembled condition of the tie in which it can be inserted into the drilled hole in the cavity wall.

Within the tube 18, and shown in Figure 6 in engagement with the smaller end of the taper plug, is an expander sleeve 21. A length of rod 23 is shown in Figure 6 to have been entered into the tube 18 to abut against the end of the expander sleeve. The rod is shown about to be punched to drive the expander sleeve along the tapered plug.

In Figure 7 the expander sleeve is shown to have been driven along the tapered plug 19 to the full extent of its travel, that is to say until it has abutted against the head of the tapered plug; in doing so it expands the inner end of the plastics tube 18 by a pre-determined extent to cause the sleeve 26 surrounding it to be forced into tight engagement with the walls of the drilled hole in the inner leaf of the cavity wall.

A further expander sleeve 25 is shown in Figure 7 to have been entered into the outer end of the plastics tube to abut against the end of the length of rod 23 and to have been forced radially outwards by a tapered plug 27.

The tapered plug 27 is a headed plug and is shown to have been driven into the expander sleeve 25 to the full extent of its travel, that is to say until the head of the plug has been brought into abutment with the expander sleeve 25. In doing so it expands the outer end of the plastics tube 18 by a pre-determined extent to cause the sleeve 26 surrounding it to be forced into tight engagement with the walls of the drilled hole in the outer leaf of the cavity wall.

It will be seen that in the arrangement illlustrated in Figures 6 and 7 the expansion of the plastics tube 18 and of the plastics sleeves 26 surrounding it takes place without any simultaneous axial movement. This is important because the walls of the drilled hole 16, particularly where it extends into or through breeze block or brick, will not be smooth. Because the expansion of the tube 18 takes place equally along the length of each expander sleeve, the longitudinal slits 20 are shown to extend a somewhat greater distance than before from the opposite ends of said tube, the metal ferrules 24 being spaced from the plastics sleeves 26, to allow the expansion of the tube ends. The fact that the expander sleeves are both enlarged to a pre-determined extent ensures that the sleeves 26 are forced radially outwards to the optimum extent.

Referring now to Figure 8, this illustrates a further possible modification which resides in the fact that the inner end of the wall tie device is secured in the inner leaf of the cavity wall by means of an adhesive 32, for example a cold setting resinous material or a polyester cold setting resin.

The method of securing the inner end of the length of tube 18 in the inner leaf includes the step of forcing the adhesive through said length of tube so that, having passed through said length of tube, the adhesive leaks back along the exterior of the tube, and through a plurality of holes 34 in the tube wall, to fill the spaces surrounding said tube within the drilled hole in the inner leaf.

The length of rod 23 is shown in Figure 8 to extend to the bottom of the hole in the inner leaf.

However, the adhesive could have been forced through the length of tube 18 using a lance (not shown) inserted into said tube to extend only a pre-determined distance through it. When the lance was subsequently removed, it would leave a space in which the length of rod 23 (somewhat shorter than that in the arrangement of Figures 6 and 7) would be inserted to abut against the mass of adhesive within the tube, that is when the adhesive was fully set.

A final step in this modified method involves the insertion of an expander sleeve 25 in the outer end of the plastics tube to abut against the end of the length of rod 23 and the radially outwards expansion of said expander sleeve by the punching of a tapered plug 27 into the position shown, this effectively securing the outer end of said tube to the outer leaf of the cavity wall.

Various other modifications may be made. For example, in Figure 7 the tapered plug 27 which has forced the expander sleeve 25 radially outwards is shown to be stepped or serrated so that it bites into the surfaces of the sleeve. In this way it is made captive and is unlikely to ever work loose.

However, the tapered plug could be a plain taper (although of a wedging angle) and it will be understood that the subsequent filling of the outer end of the drilled hole with mortar in the arrangements shown in Figures 7 and 8 should safely retain the tapered plug in position. In any one of the embodiments described, the at least one end of the length of tube need not necessarily have a plurality of longitudinal slits. It may be found sufficient to provide at least one end of said tube with but a single longitudinal slit or perhaps a pair of such slits located diametrically opposite each other.

It is sometimes a requirement for a pull test to be carried out on at least some of the wall tie devices being used to brace inner and outer leaves of a cavity wall. Any of the wall tie devices described above can be tested for adequate securement in the inner leaf. By way of example, in Figure 9 there is illustrated an arrangement after the integrity of the fixing of the length of tube 18 in the inner leaf has been tested, the tie device being similar to that of Figure 8.

Referring now to Figure 9, it will be seen that an extra long length of tube 18 has been used so that after its inner end portion has been secured in the inner leaf of the cavity wall concerned the outer end of the tube has projected from the face of the outer leaf as shown in chain-dotted lines.

It is possible to carry out a pull test by using apparatus (not shown) capable of being clamped onto the projecting outer end of tube.

After the pull test is completed, the projecting end of tube is sawn off flush with the face of the outer leaf. The tube is then secured to said outer leaf by inserting an expander sleeve 25 in said tube to abut against the end of an extra length rod 23. The radially outwards expansion of the expander sleeve is effected by punching the tapered plug 27 into the position shown, the outer end of the head of the plug being located flush with the face of the outer leaf to provide a 'witness' mark of the fact that the associated tie has been tested.

In Figures 10 and 11 there is illustrated the use of a tool whereby any of the previously illustrated tie devices may be tested at random. By way of example, one of the tie devices as illustrated in Figure 7 is shown being tested in Figures 10 and 11, that is to say being tested for grip in the inner leaf.

Referring to Figure 10, the tool referred to is constituted by a steel sleeve 36; a steel pull rod 38 with a tapered inner end portion 40 which terminates in a circumferential flange 42; and a collar 44 which has screwthreaded engagement on a screwthreaded outer end portion of said rod. An inner end portion of the steel sleeve has a number of longitudinal slits to enable it to be outwardly flared as will presently be described. As shown in Figure 10, a tie device of the kind illustrated in Figure 7 has been dismantled, that is to say has had its tapered plug 27, its expander sleeve 25 and its length of rod 23 removed so that the tool referred to has been able to be entered into its length of synthetic plastics tube 18.

Having been entered into the length of tube 18 in the condition in which it is illustrated in Figure 10, the tool is secured by its inner end within said tube 18. This is done by advancing the collar 44 along the screwthreaded outer end of the pull rod so that said pull rod is retracted relative to the steel sleeve; the inner end of the steel sleeve is thus outwardly flared by the tapered inner end portion 40 of the pull rod being forced into it.

The abutment of the flared end of the steel sleeve against the flange 42 prevents excessive flaring of the sleeve.

It will be seen in Figure 11 that the outward flaring of the inner end of the steel sleeve has taken place to the left of the innermost ferrule 24 as viewed in the drawing. It will thus be understood that the ferrule prevents the synthetic plastics tube 18 from splitting and provides an anchor for the testing tool.

When the testing tool has been secured to the synthetic plastics tube as shown in Figure 11, a pre-determined load can be imposed on the collar 44, as represented by the arrows P, to test the grip of the length of tube in the inner leaf.

It will of course be understood that the same or a similar testing tool can be used for testing any of the other illustrated tie devices (although some of these may require to be slightly modified themselves, as for example by the fitting of a ferrule at a particular location along its length purely to enable such a tool to be connected to it if required).

In all the illustrated embodiments, the wall tie concerned is simple to use and can be installed in a minimum of time due to the fact that the holes in the inner and outer leaves are of the same diameter and due also to the fact that no screwthreading action is involved. When installed, the devices are neither in compression nor in tension. Various wall ties which have previously been used have suffered from one or more of the disadvantages which the present invention overcomes, being complicated and time consuming to use and being either in compression or in tension when installed.

Claims

CLAIMS:

1. A method of bracing together two spaced apart members at a fixed spacing, the method including the steps of drilling a hole through one member and into the other; inserting a length of tube through the hole in said one member to locate an inner end of the tube in the hole in said other member and an outer end in said one member; securing the inner end of said tube in the hole in said other member; and subsequently driving a tapered plug into the outer end of the tube to cause an outer end portion of said tube to expand to become tightly wedged in the hole in said one member.

2. A method according to claim 1, including the initial step of slitting the walls of the length of tube at least along a portion of the length that is to be its outer end.

3. A method according to either one of the preceding claims, including the preliminary step of fitting a resilient sleeve on the length of tube at least at what is to be its outer end.

4. A method according to any one of the preceding claims, including the step of entering a length of rod into the tube to act as a fixed abutment member, inserting an expander sleeve into the outer end of the length of tube to abut against the rod, and driving a tapered plug into the expander sleeve to force it radially outwards and to expand the outer end of the length of tube.

5. A method according to any one of the preceding claims, including the step of securing the inner end of the length of tube in the hole in said other member by push-fitting a tapered plug in what is to be its inner end before the tube is inserted into the hole in the two members, and subsequently driving the tube into the hole so that its inner end has been forced onto the tapered plug as the latter has seated against the bottom of the hole, or by fitting a tapered plug and an expander sleeve at what is to be the inner end of said tube and using a length of rod entered into said tube to drive the expander sleeve along the tapered plug, the inner end of the tube thus having been expanded to become wedged in the hole.

6. A method according to claim 5, including the preliminary step of fitting a resilient sleeve on the length of tube at what is to be its inner end.

7. A method according to any one of claims 1 to 4, including the step of securing the inner end of the length of tube in the hole in said other member by forcing an adhesive through said length of tube to introduce the adhesive along the exterior of the tube and adhere the tube within the drilled hole in said other member in which it has been located.

8. A tie device for bracing together two spaced apart members at a fixed spacing, the tie device including a length of tube at least one end of which has at least one longitudinal slit, at least one ferrule embracing said tube and plug means for radially expanding the tube at least at the end thereof which has the at least one longitudinal slit.

9. A tie device accordng to claim 8, including at least one synthetic plastics sleeve for fitment on an end length of the tube which has the at least one longitudinal slit.

10. A tie device according to either one of claims 8 and 9, in which the plug means for radially expanding the tube are constituted by a headed tapered plug and an expander sleeve which co-operate in the slitted end length of the tube.

11. A tie device according to claim 10, including a length of rod which can be entered into the length of tube to abut against the end of the expander sleeve.

12. A tie device according to either one of claims 10 and 11, in which the tapered surface of the or each tapered plug is stepped or serrated to bite into the surfaces of the associated sleeve.

13. Means for testing the grip of a tie device according to any one of claims 8 to 12 in one of the two spaced apart members which are to be braced together, said means comprising a tool having a sleeve, a pull rod with a tapered inner end portion terminating in a circumferential flange, and a collar having screwthreaded engagement on a screwthreaded outer end portion of said rod.

14. A method of bracing together two spaced apart members at a fixed spacing, substantially as hereinbefore described.

15. A tie device for bracing together two spaced apart members at a fixed spacing, the device being constructed, arranged and adapted to be used, substantially as hereinbefore described with reference to and as illustrated by Figures 1 to 5, or Figures 6 and 7, or Figure 8 or Figure 9 of the accompanying drawings.

16. Means for testing the grip of a tie device in one of two spaced apart members which are to be braced together, constructed, arranged and adapted to be used substantially as hereinbefore described with reference to and as illustrated by Figures 10 and 11 of the accompanying drawings.