GB2302886A - Resstraint strap for use in buildings - Google Patents

Abstract

A restraint strap for use in the building industry comprising an elongate steel element (10) having a series of apertures (12) along its length, preferably arranged in two staggered rows, and having its longitudinal edges (14, 14A) folded back substantially flat against the main body of the strap, more especially by an amount between 8 and 16 per cent of the width of the original planar blank.

Description

Restraint Strap This invention relates to a restraint strap for use in the building industry.

Restraint straps are used in the building industry, more particularly, to provide ties or bracing between timber work such as roof structures and parts thereof to brickwork and blockwork, for example to transfer wind and other forces from walls to roof structures and vice versa. For fixing purposes, the strap can be bent, twisted or fishtailed at any one or more points along its length. The apertures enable the strap to be fixed in position by use of galvanised nails or the like.

The conventionally used restraint strap, prior to bending or twisting for any particular application, is an elongate planar element supplied in various thicknesses. The thicker elements, in particular, are relatively expensive as their construction requires a considerable quantity of steel.

According to the present invention, there is provided a restraint strap for use in the building industry, comprising an elongate steel element having a series of apertures along its length and having its longitudinal edges folded back to point towards one another.

The invention enables the production of restraint straps which, without loss of inherent strength due to the inturned longitudinal edges, require for their construction a reduced amount of steel. Ability to hend, twist or fishtail the strap at any one or more points along its length is retained, again without loss of strength at the hend or twist.

A preferred strap is made of galvanised mild steel. The apertures enahling fixing are preferahly arranged in two longitudinal rows, the apertures in one row heing staggered relative to the apertures in the other row.

The preferred strap is inwardly folded at each longitudinal edge by an amount between 8 and 16 per cent of the width of the original planar blank. Typically, a strap of approximately 30 mm final width may have inturned edges each of about 4 mm width.

The inturned edges are preferably folded back flat against or at least closely adjacent the main body of the strap, so that the overall depth of the strap is only a little more than twice the gauge of the basic steel strip. A suitable gauge for this basic steel strip is approximately 2 mm, but a lesser or greater gauge may be used according to requirements. In all instances, for a corresponding strength, a lesser gauge is necessary than with conventional restraint straps.

An exemplary restraint strap in accordance with the invention is shown in the accompanying drawings, in which: Figures 1 and 2 show the restraint strap in end view and plan view; and Figure 3 shows a detail of the folding operation used in production of the strap.

The illustrated restraint strap 10 is made of galvanised mild steel. It has two rows of staggered 6 mm apertures 12, as is conventional practice. It also has its longitudinal edges 14, 14A equally folded back to point towards one another, as can be seen from Figure 1 in particular.

A typical restraint strap as illustrated may have a finished overall width of about 30 mm, with about 4 mm folded back at each longitudinal edge. In consequence, the depth of the strap is about 4.5 mm.

Figure 3 shows that the folding operation at a longitudinal edge is effected about a single centre 16, so that the folded back edge lies flat against or closely adjacent the main body of the strap. This manner of folding back is to be distinguished from rolled edges, over an angle of 270 degrees or more in which the turned back portions point towards the main body of the strap.

Claims (9)

Claims

1. A restraint strap for use in the building industry, comprising an elongate steel element having a series of apertures along its length and having its longitudinal edges folded back to point towards one another.

2. A restraint strap as claimed in claim 1, made of galvanised mild steel.

3. A restraint strap according to claim 1 or claim 2, wherein the apertures enabling fixing of the strap are arranged in two longitudinal rows.

4. A restraint strap according to claim 3, wherein the apertures in one row are staggered relative to the apertures in the other row.

5. A restraint strap according to any of claims 1 to 4, wherein the strap is inwardly folded at each longitudinal edge by an amount between 8 and 16 per cent of the width of the original planar blank.

6. A restraint strap according to claim 5, wherein a strap of approximately 30 mm final width has inturned edges each of about 4 mm width.

7. A restraint strap according to any of claims 1 to 6, wherein the inturned edges are folded hack flat against or at least closely adjacent the main body of the strap, so that the overall depth of the strap is only a little more than twice the gauge of the basic steel strip.

8. A restraint strap according to claim 7. wherein the gauge of the basic steel strip is approximately 2 mm.

9. A restraint strap substantially as hereinhefore described with reference to the accompanying drawings.