GB2265920A

GB2265920A - Two-part wall tie

Info

Publication number: GB2265920A
Application number: GB9307591A
Authority: GB
Inventors: Mark Stephenson
Original assignee: Ancon Clark Ltd
Current assignee: Ancon Clark Ltd
Priority date: 1992-04-10
Filing date: 1993-04-13
Publication date: 1993-10-13
Anticipated expiration: 2013-04-13
Also published as: GB9307591D0; GB2265920B

Abstract

A wall tie having two portions 1, 30 which in use are embedded in respective leaves of a cavity wall. Each portion has interlocking formations thereon so as to allow the two portions to be connected in use against extension of the assembled tie. Portion 1 is embedded in mortar in a first wall leaf, and later, portion 30 is connected by inserting end 55 into slot 20 and turning until slots 60 embrace metal each side of slot 20 so as to give a generally planar two-part tie, portion 30 then being embedded in mortar in a second wall leaf. <IMAGE>

Description

"WALL TIE" This invention relates to a wall tie.

A conventional wall tie comprises a single length of metal which may be formed from wire but requires complex bending operations in the manufacturing process. Alternative designs include fishtail types formed from sheet steel which require their ends to be split and spread apart and strip ties having preformed angled ends to anchor the tie more securely within the wall leaves.

The disadvantages of conventional designs include sharp edges of ties protruding from leaves, and in particular, the tendency of conventional ties to over-balance during construction of a wall. This problem occurs frequently when the inner leaf is constructed in advance of the outer leaf; ties tend to over-balance when placed on the upper surface of the inner leaf before the next layer of bricks is applied.

According to the present invention, there is provided a wall tie having first and second members each of which has an end portion for embedment in a respective leaf of a cavity wall and of a form to resist withdrawal therefrom, the members being initially separate but connectable together through interlocking formations thereon in a manner such that they are locked together against extension of the assembled tie.

From another aspect, the invention provides a method of tying together leaves of a cavity wall comprising providing a wall tie as defined in the preceding paragraph, embedding the end portion of the first member of the wall tie into a first leaf of the wall so that a part of the first member extends from the first leaf towards an intended location of a second leaf of the wall, connecting the second member of the wall tie to the first member by means of the interlocking formations, and embedding the end portion of the second member into the second leaf of the wall.

Preferably, the interlocking formations comprise male and female portions provided respectively on the members, for example a head portion on one of the members which engages within a slotted portion of the other member. The interlocking formations are preferably adapted to allow a limited range of pivotal movement of the members relative to each other.

Preferably, also the interlocking formations are such as to lock the members together against extension and contraction of the assembled tie.

Preferably, the end portion of at least one of the respective members is of a fishtail form and/or has indentations and/or apertures therein, and/or may comprise a portion which is outwith the planeof the respective member.

An embodiment of the present invention will now be described by way of example, with reference to the accompanying drawings in which: Fig 1 is a plan view of a first member of a wall tie of this invention; Fig 2 is a side view of the member shown in Fig 1; Fig 3 is a plan view of a second member of a wall tie of this invention, for use with the member of Figs 1 and 2; and Fig 4 is a side view of the member shown in Fig 3.

Fig 5 is a plan view of an alternative design of second member.

Referring now to the drawings, a wall tie has a first member 1 comprising an elongate steel strip having a mid section 5, and an end 7 which is split to form a "fishtail" structure whose elements 10, 12 are bent in opposite directions out of the principal plane of the mid section 5 of the member 1.

The other end of the member 1 is bent through 90" at 17 to form a dependent portion 18, and a slot 20 extends along that end portion of the mid section 5 and the dependent portion 18, terminating short of the end of the dependent portion 18.

The preferred dimensions (in mm) of the first member as follows: length: 140; breadth at 5: 20-50; breadth between tips of end sections 10 and 12: 30-50; height between tips of end sections 10 and 12: 5. Naturally, it will be understood that the wall tie of the present invention is not limited to those dimensions.

A second member 30, 31 of the wall tie also comprises an elongate steel strip having a mid section 32, and an end 35 which is split to form a "fishtail" structure whose elements 38, 40 are bent in opposite directions out of the principal plane of the mid section 32 of the member. The preferred (but not limiting) dimensions (in mm) of the breadth at 32 and of the end 35 of the second member 30, 31 are as described for the corresponding portions of the first member. The length of the second member 30, 31 may be variable.

The mid section 32 is bent at 45 to form a protrusion which serves as a drip formation.

The other end 50 of the member 30, 31 has a head 55, and a neck 57 between two laterally disposed slots 60.

The head 55 may incorporate a generally dovetail like structure as shown in Fig 3 or may alternatively have parallel edges at 51 adjacent to the slot 60 as shown in Fig 5. All other reference numerals for Fig 5 correspond to those for Fig 3.

In use, the first member is placed within wet mortar on the upper face of a leaf under construction. The end 7 of the member is located within the leaf but the dependent portion 18 protrudes from the surface. The member does not over-balance since the weight of the protruding portion is not sufficient to overcome the weight of the portion supported by the mortar. The leaf is constructed with first members incorporated at suitable intervals with their free end sections and dependent portions 18 protruding towards the intended location of the second leaf.

The "fishtail" and out of plane features of the end sections 10, 12 anchor the member in place when the mortar has dried, thereby preventing movement of the member relative to the leaf.

When the second leaf of the cavity wall is constructed, the second members are built into the leaf in the same manner as described above at intervals which correspond to the locations of the first members. However, before embedment of each second member in the mortar, and application of a subsequent layer of bricks, the head 55 of the second member 30 or 31 is inserted into the slot 20 of the first member 1. This is achieved by disposing the second member such that its main axis is perpendicular to that of the first member and the plane of the second member is coplanar with the main axis of the first member. The position of the second member is adjusted relative to the first member such that the neck 57 on the second member is coplanar with the first member. The second member is then rotated through 90" about its main axis such that the portions of the first member defining the slot 20 engage in the slots 60.

The orientation of the second member at this stage is such that the protrusion at 45 on the second member points in an appropriate direction such that when the second member is moved along the slot 20 around the bend 17 until the two members are substantially coplanar, the protrusion at 45 points downwards. The head 55 is thereby locked against the dependent section 18 and axial movement of the two interlocked members relative to one another in either axial direction is prevented.

The downwardly pointing protrusion at 45 serves as a drip formation point to prevent moisture transfer to either leaf.

The end 35 of the second member 30 is then embedded in mortar on the second leaf and is anchored therein by virtue of the out of plane fishtail features on the end 35 of the second member 30. Thus the two leaves are locked together by the tie.

Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims

1 A wall tie having first and second members each of which has an end portion for embedment in a respective leaf of a cavity wall and of a form to resist withdrawal therefrom, the members being initially separate but connectable together through interlocking formations thereon in a manner such that they are locked together against extension of the assembled tie.

2 A wall tie as claimed in Claim 1, wherein the interlocking portions comprise male and female portions provided respectively on the members.

3 A wall tie as claimed in Claim 2, wherein the male portion comprises a head portion and the female portion comprises a slotted portion.

4 A wall tie as claimed in Claim 2 or 3, wherein the interlocking formations are adapted to allow pivotal movement of the members relative to each other.

5 A wall tie as claimed in any one of the preceding Claims, wherein the interlocking formations prevent contraction and extension of the tie when the members are connected by the interlocking formations.

6 A wall tie as claimed in any one of the preceding Claims, wherein the end portion of each member comprises a fishtail structure.

7 A wall tie as claimed in any one of the preceding Claims, wherein the end portion of each member comprises a portion which is outwith the plane of the respective member.

8 A wall tie as claimed in any one of the preceding Claims, wherein the end portion of each member has at least one aperture therein.

9 A wall tie as claimed in any one of the preceding Claims wherein the end portion of each member has at least one indentation thereon.

10 A method of tying together leaves of a cavity wall comprising providing a wall tie as defined in any one of the preceding Claims, embedding the end portion of the first member of the wall tie into a first leaf of the wall so that a part of the first member extends from the first leaf towards an intended location of a second leaf of the wall, connecting the second member of the wall tie to the first member by means of the interlocking formations, and embedding the end portion of the second member into the second leaf of the wall.

11 A wall tie substantially as herein described with reference to and as shown in Figs 1, 2, 3, 4 or 5 of the accompanying drawings.

12 A method of tying together leaves of a cavity wall substantially as herein described with reference to Figs 1, 2, 3, 4 or 5 of the accompanying drawings.