AU747312B2 - Wall tie - Google Patents

Description

WO 00/14349 PCT/GB99/02706 WALL TIE This invention relates to a wall tie for use in cavity wall constructions.

Wall ties are positioned at regular intervals between the two walls of a cavity wall construction to help secure them together. Ties also include a dip or kink to prevent the passage of moisture from the outer wall to the inner wall.

Such ties are traditionally made of metal, advantageous both for strength and low cost. They are also traditionally of one piece construction.

This means that they protrude once one end is laid in the first wall, often thus hindering or injuring the bricklayer whilst he lays the second wall.

Hingeable wall ties made of plastic have been suggested in GB-A- 2259528. However, plastic ties naturally are more inclined to break, especially in the environment of a busy building site. Breakage of a tie already laid into one wall obviously negates its use entirely, and the "hinges" in the ties of GB-A-2259528 are created by "thinned portions", which are naturally more prone to easy breakage. Thinned portions also weaken the tensile strength of a wall tie, requiring the portions to be of "adequate" width, which increases the amount of material required to make such a wall tie.

Moreover, whilst the ties in GB 2259528 are stated as being foldable to an out of the way position during wall construction, most plastics have a natural desire or resilience to return to their original shape, i.e. to fold back.

Thus there is no guarantee that a foldable plastic wall tie will remain folded during the interval between the building of an outer wall and an inner wall.

WO 00/14349 PCT/GB99/02706 2 It is an object of the present invention to overcome such disadvantages.

Thus, according to one aspect of the present invention, there is provided a metal wall tie comprising two connected tie-parts, each tie part having one end adapted to be positioned between two layers of a brick wall, whilst the other ends have interlocking means to connect the tie-parts, and to allow relative movement but not separation of the two tie-parts.

Each end of the tie-parts to be positioned in the walls may have any suitable shape, size or design. A common shape is a fish tail, easily formable from an elongate metal piece.

The wall tie of the present invention may use any metal and any form of metal piece. A common metal and form used for traditional one piece wall ties is stainless steel with a circular cross-section. Each tie-part may be of similar or different length, width and height. Preferably, one tie-part is longer than the other tie-part.

The wall tie of the present invention may have any suitable form of interlocking means at its connected ends. The meeting ends may be different or similar in shape, size and design. Nevertheless, the form of interlocking should still allow at least some movement of the two tie-parts. Preferably, the interlocking means allows sufficient movement to move one tie-part to an out of the way position whilst the second wall is being laid, and to allow some difference in height between the inner and outer walls to be accommodated.

More preferably, the tie-parts have relatively loose and free movement in relation to each other, e.g. rotational one- or two-dimensional movement based on minimal inter-tie contact.

The interlocking means should not however allow separation of the tieparts. Losing the second tie-part after the first tie-part is laid in the first wall, WO 00/14349 PCT/GB99/02706 WO 00/14349 PTG9/20 3 a strong possibility on a busy building site, is akin to breakage of a one-piece wall tie. The disadvantage of this is mentioned above.

An embodiment of the present invention will now be described, by way of example only, and with reference to the accompanying diagrammatic drawings in which:- Fig. 1 is a perspective view of a wall tie according to the present invention; Fig. 2 is a plan close-up view of the interlocking between the tie-parts in Fig. 1; and Fig. 3 is a diagrammatic side view of the wall tie in Fig. 1 in use.

Referring to the drawings, Fig. 1 shows a metal wall tie comprising two tie-parts 2. The length of one tie-part 2, usually that tie-part intended to be laid in the first wall to be built, is shorter than the other tie-part 2. One end 4 of each tie-part has a fish-tail shape created by folding the metal rod in a generally triangular shape, so as to provide sufficient contact with the mortar between two layers of brick in a wall.

From each fish-tail end, each tie-part 2 extends directly to the interlocking means, which is formed by interweaving and folding back each end to form interlocking hooks 8. One hook is transverse to the other, as more clearly shown in Fig. 2. The hooks are formed to be wholly or substantially closed, so as to prevent separation. A metal rod of e.g. 3mm diameter is easily foldable in this way.

The interlocking means allows loose and unrestrained transverse and vertical rotational movement between the two tie-parts 2. Some variation in the levels of the inner and outer walls can therefore be accommodated.

As shown in Fig. 3, the movement provided by the interlocking means also allows one tie-part 2 to be moved sideways and/or upwards or WO 00/14349 PCT/GB99/02706 4 downwards relative to the other tie-part 2 once fixed or laid into the first wall The free tie-part is therefore movable to an out of the way position so as not to interfere with or impede the builders whilst the second wall 12 is being built. The wall tie does not therefore extend or protrude continually at its full length during the interval between building the first wall 10 and the building of the second wall 12, avoiding injury in the meanwhile. Once required, the out of the way wall tie 2 is readily returnable to its desired position for building into the second wall 12.

A further advantage of the interlocking means is that it provides an lo inherent barrier to the passage of moisture from one end to the other end in use. At least one part of the interlocking means is lower than the general extension of the tie-parts in whatever orientation the wall tie is used. Further working of the wall tie to provide a dip or kink, or the addition of a drip collar, is therefore unnecessary, saving manufacturing time and costs.

An insulation holding collar 14, or if desired an additional drip collar, can be fitted to the wall tie of the present invention as shown in Fig. 1 in substantially the same manner as in prior art metal wall ties. The holding collar 14 is to support upright a sheet of insulation inserted in the cavity end against the inside of the second wall 12 during wall construction.

The present invention provides an articulated wall tie, still made of metal for the strength and resilience required on a building site. The wall tie is easily formable from simple metal rod, requiring less forming machinery and equipment than that required for the making of a plastic wall tie.

The metal wall tie of the present invention will not break, yet still provides the benefits of a hinge between its ends.

Variations and modifications can be made without departing from the scope of the invention and as defined in the claims hereinafter.

EDITORIAL NOTE NO.56333/99 Previous claims pages 5 and 6 now replaced by claims pages 8 and 9. Therefore there are no pages 5-7.

Claims (2)

1. 05-09-2000 GB 00990270G6 CLAIMS: 1. A metal wall tie comprising two tie-parts, each tie part having one end adapted to be positioned, in use, between two layers of one wall of a double brick wall, each tie part is a length of formed wire into a stem with one end folded into a retaining member of planar fish-tail shape and wherein the tie parts are held captive together at their other end by interlocking means which allows relative movement but not separation of the two tie-parts, the interlocking means being formed by interweaving and folding back each other end to form interlocking hooks with the hooks formed transverse of each other. 2. A wall tie as claimed in Claim 1, wherein the stem of one tie-part is longer than the other tie-part. 3. A wall tie as claimed in Claim 1 or 2, wherein the interlocking means allows sufficient movement with one tie-part secured in one wall to move the other tie-part to an out-of-the-way position whilst the second wall is being laid and to allow some difference in height between the first and second walls to be accommodated. 4. A wall tie as claimed in Claim 3, wherein the tie-parts have relatively loose and free movement in relation to each other for rotational one- or two- dimensional movement based on minimal inter-tie contact. A wall tie as claimed in any one of the preceding Claims, wherein the longer tie-part is provided with an insulation holding collar for use in AMENDED SHEET -21 9 0 0 GB 00.9902706 9 supporting upright a sheet of insulation inserted in a cavity of a cavity wall against the inside of one wall during wall construction.
2. 6. A wall tie substantially as hereinbefore described with reference to the accompanying drawings. AMENDED SHEET