GB2124293A

GB2124293A - Fasteners for wire mesh

Info

Publication number: GB2124293A
Application number: GB08320148A
Authority: GB
Inventors: Andrew Philip George Herring; Peter Graham Hooker
Original assignee: ITW Ltd
Current assignee: ITW Ltd
Priority date: 1982-07-27
Filing date: 1983-07-26
Publication date: 1984-02-15
Also published as: GB8320148D0

Abstract

A one-piece plastics fastener in the form of a stud 40 includes a plurality of projections 44 on a generally planar member 42. Each of the projections 44 includes one or more barbs 46 which are resiliently deformable to permit passage through the interstices 80 of a lattice-like element, such as wire mesh 76, but to resist subsequent release of the wire strands 78. A similar one-piece plastics fastener in the form of a washer is also disclosed. In either form of the fastener, a self-securing shank 54 may be secured to a wall 70 covered by thermal insulation 72, with the wire mesh 76 providing support for an external rendering 82. <IMAGE>

Description

SPECIFICATION Fasteners for lattice-like elements such as wire mesh The present invention relates to fasteners which have been particularly, but not exclusively, designed for use with lattice-like elements such as wire mesh.

An example of a typical use is in the upgrading of old property. Outside walls of the property may be covered by thermal insulation which is then itself covered by a wire mesh to give support for an external rendering. It is desirable to ensure that the wire mesh lies at a constant preset spacing from the thermal insulation. If the spacing varies too much the external rendering will not be properly supported.

The present invention therefore aims to provide a fastener which is simple and cheap to manufacture yet is easy and reliable to use.

A one-piece plastics fastener for use in fastening a lattice-like element, such as wire mesh, including a framework defining an array of interstices comprises a generally planar member and a plurality of projections extending generally perpendicularly from one face of the generally planar member, with each of the projections having one or more barbs inclined back towards the generally planar member, and each of the barbs being resiliently deformable to permit passage through the interstices of a lattice-like element, in use, but to resist subsequent release of the framework of the lattice-like element.

The projections may be arranged in a straight line, in which case the generally planar member is preferably of substantial area on both sides of said straight line. Each of the projections may be formed with two barbs at those ends of the projections further from the generally planar member to give the appearance of an arrow head and to provide lead-in for the lattice-like element.

There may be at least four of the projections, and preferably there is at least eight of the projections.

If the external rendering is to be comparatively thick, making it desirable for the wire mesh to be held some distance away from the thermal insulation, a plurality of ribs may extend from said one face of the generally planar member for holding the lattice-like element away from the generally planar member, with the ribs possibly being integral with and extending between the projections at those ends of the projections closer to the generally planar member.

A plurality of webs may extend from the other face of the generally planar member for supporting peripheral regions of the generally planar member and, particularly if the thermal insulation is formed of foam, rather than of board, those webs may be pressed into the foam.

The fastener may have a self-securing shank extending generally perpendicularly from said other face of the generally planar member and thus be in the form of a stud. Alternatively the fastener may be in the form of a washer and have an opening through which a screw, nail, selfsecuring shank or other separate fix could be inserted to extend generally perpendicularly from said other face of the generally planar member.

The self-securing shank may be of the kind disclosed in our British patent 1 451 009 which claims a one-piece plastics drive fastener including a head and a shank, the shank having a generally polygonal, axially extending body portion which provides a plurality of radially outwardly facing, flat surfaces separated from one another by angularly disposed recesses, a plurality of integral, resilient independent wings extending radially outwards from each of the surfaces at axially spaced intervals, the wings on certain of the surfaces being axially offset from the wings on the other surfaces, the juncture of the wings and the surfaces being along straight lines.

It will be appreciated that, in general terms, a plurality of the fasteners according to the present invention are preferably used in a method of fabrication in which a layer of a first material (such as thermal insulation) is applied to a substrate (such as a wall), the fasteners are secured to the substrate in spaced positions so that the generally planar members of the fasteners lie against the exposed face of the first material, a lattice-like element (such as wire mesh) is applied to the fasteners by fastening the lattice-like element to the projections of the fasteners, and a layer of a second material (such as external rendering) is applied to cover the lattice-like element, the fasteners and the layer of the first material.

One-piece plastics fasteners, in accordance with the present invention, will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an underneath view of a first of said fasteners in the form of a washer; Figure 2 is a cross-section taken along the broken line Il-Il of Figure 1; Figure 3 is a side view taken in the direction of the arrow Ill of Figure 2; Figure 4 is a plan view of a second of said fasteners in the form of a stud; Figure 5 is a side view taken in the direction of the arrow V of Figure 4; Figure 6 is a fragmentary side view taken in the direction of the arrow VI of Figure 5; Figure 7 is a fragmentary underneath view taken in the direction of the arrow VII of Figure 5; and Figure 8 is a schematic view similar to Figure 5 but also showing a house wall, a thermal insulation board, a wire mesh and an external rendering.

Referring initially to Figures 1 to 3, a first fastener in accordance with the present invention is shown which is moulded in one-piece of 10% talc-filled polypropylene in the form of a washer 10.

The washer 10 presents an annular planar member 12 of star-shape.

On one face, an open-ended tube 1 4 extends perpendicularly from the inner periphery of the member 12. The right-hand end of the tube 14 (as shown in Figure 2) has a frusto-conical portion 1 6 to compiement a countersunk head of a standard screw anchor to be located in the tube 1 4. The left-hand end of the tube 14 (as shown in Figure 2) has a recess 18 to receive an enlarged head of a standard push-in hole plug to close the tube 1 4.

Six webs 20 extend radially outwards between the tube 1 4 and the outer periphery of the member 12.

On the other face, a total of eight projections 22 extend perpendicularly from the member 12.

The free end of each of the projections 22 has a pair of symmetrically arranged barbs 24 which are inclined back towards the member 1 2 and give the appearance of an arrow head. The projections 22 are arranged in a straight line with opposed side faces 26, 28 of the barbs 24 being arranged in a pair of parallel planes. Ribs 30 are integral with and extend between the right-hand ends of the projections 22 (as shown in Figure 2) apart from at the central opening of the annular member 12.

Before discussing the manner of use of the washer 10, it will be convenient to refer to Figures 4 to 7, which show a second fastener in accordance with the present invention again moulded in one-piece of 10% talc-filled polypropylene, but in the form of a stud 40.

The stud 40 present a continuous planar member 42 of indented square-shape.

On one face, in a very similar arrangement to that described hereinbefore with reference to the washer 10, a total of eight projections 44 extend perpendicularly from the member 42. The free end of each of the projections 44 has a pair of symmetrically arranged barbs 46 which are inclined back towards the member 42 and give the appearance of an arrow head. The projections 44 are arranged in a straight line with opposed side faces 48, 50 of the barbs 46 being arranged in a pair of parallel planes. Ribs 52 are integral with and extend between those ends of the projections 44 closer to the member 42.

On the other face, a self-securing shank 54 extends perpendicularly from the member 42 but in the opposite direction to the projections 44. For an initial part of its length (moving downwards as shown in Figure 5) the shank 54 is of cruciform cross-section, but then changes to a part of polygonal cross-section, before finally reaching a part of circular cross-section. The initial part of cruciform cross-section is formed by opposed pairs of ribs 56, 58. To provide additional support the ribs 56 may extend to the outer periphery of the member 42. The final part of circular crosssection reduces in diameter to form a leading point 60.

The part of the shank 54 of polygonal crosssection provides four radially outwardly facing, flat surfaces 62 separated from one another by angularly disposed recesses 64. A plurality of integral, resilient independent wings 66 extend radially outwards from each of the surfaces 62 at axially spaced intervals. The wings 66 on an opposed pair of the surfaces 62 are axially offset from the wings 66 on the other opposed pair of the surfaces 62. The juncture of the wings 66 and the surfaces 62 are along straight lines. A more complete description appears in our British patent 1 451 009 to which a reader is directed to refer.

A typical use of the stud 40 is shown schematically in Figure 8. An outside wall 70 of a house to be upgraded is covered by a board 72 of thermal insulation. The stud 40 is driven through the board 72 and into a preformed blind bore 74 in the wall 70. The bore 74 is of smaller diameter than that of the circle circumscribing the free peripheral edges of the wings 66 on the stud 40.

This means that the wings 66 are resiliently deflected and press against the wall 70. The stud 40 is secure when the member 42 presses against the board 72 and all of the wings 66 on the shank 54 have entered the bore 74. A standard wire mesh 76 is then secured by hand to the projections 44 on the stud 40. The mesh 76 may be formed from interwoven strands 78 of wire presenting a lattice-like framework separating a regular array of interstices 80. Adjacent strands of the wire of the mesh 76 are pushed between the projections 44 until they rest on ribs 52. To permit the strands 78 to reach the ribs 52, the barbs 46 on the projections have to be resiliently deformed.

After passage of the strands, the barbs 46 spring back to their undeformed state and then resist release of the mesh 76. Finally, a coating of external rendering 82 is applied to the board 72, for example by spraying, the thickness of the coating being sufficient to well cover the mesh 76.

The manner of use of the washer 10 is substantiaily the same as that of the stud 40, the main differences being that the washer 10 is more suitable for use with thermal insulation formed of foam, because the webs 20 can press into the foam, with a separate fix being driven through the tube 14 to secure the washer 10, and a separate hole pluy being applied to close the tube 14 before the external rendering is itself applied.

It will be appreciated that the dimensions of the interstices of the wire mesh will influence how many of the strands are trapped by a given fastener in accordance with the present invention.

It is envisaged that normally just one or two of the strands will be trapped. However, the fastener should not normally be provided with just four projections, but instead with six, eight or even more projections. This means that the fastener does not need to be accurately positioned to ensure operative interengagement with the wire mesh.

It will also be appreciated that many variations and modifications are possible for a fastener in accordance with the present invention. For example, the plastics material need not have a talc filling. Moreover, the generally planar member need not necessarily be of star-shape, or indented square-shape, but could be circular, or rectangular, or indeed of any convenient shape.

Claims

1. A one-piece plastics fastener for use in fastening a lattice-like element, such as wire mesh, including a framework defining an array of interstices comprising a generally planar member and a plurality of projections extending generally perpendicularly from one face of the generally planar member, with each of the projections having one or more barbs inclined back towards the generally planar member, and each of the barbs being resiliently deformable to permit passage through the interstices of a lattice-like element, in use, but to resist subsequent release of the framework of the lattice-like element.

2. A fastener according to claim 1, in which the projections are arranged in a straight line.

3. A fastener according to claim 2, in which the generally planar member is of substantial area on both sides of said straight line.

4. A fastener according to any preceding claim, in which each of the projections is formed with two barbs at those ends of the projections further from the generally planar member.

5. A fastener according to any preceding claim, in which there are at least four of said projections.

6. A fastener according to claim 5, in which there are at least eight of said projections.

7. A fastener according to any preceding claim, in which a plurality of ribs extend from said one face of the generally planar member for holding the lattice-like element away from the generally planar member.

8. A fastener according to claim 2 and claim 7, in which the ribs are integral with and extend between the projections at those ends of the projections closer to the generally planar member.

9. A fastener according to any preceding claim, in which a plurality of webs extend from the other face of the generally planar member for supporting peripheral regions of the generally planar member.

10. A fastener according to any one of claims 1 to 9 which is in the form of a stud with a selfsecuring shank extending generally perpendicularly from said other face of the generally planar member.

11. A fastener according to any one of claims 1 to 9 which is in the form of a washer having an opening through which a separate self-securing shank may be inserted to extend generally perpendicularly from said other face of the generally planar member.

12. A fastener according to claim 10 or claim 11, in which the self-securing shank has a generally polygonal, axially extending body portion which provides a plurality of radially outwardly facing, flat surfaces separated from one another by angularly disposed recesses, a plurality of integral, resilient independent wings extending radially outwards from each of the surfaces at axially spaced intervals, the wings on certain of the surfaces being axially offset from the wings on the other surfaces, the juncture of the wings and the surfaces being along straight lines.

1 3. A one-piece plastics fastener substantially as hereinbefore described with reference to Figures 1 to 3 or Figures 4 to 8, of the accompanying drawings.

14. A plurality of fasteners according to any preceding claim when used in a method of fabrication in which a layer of a first material is applied to a substrate, the fasteners are secured to the substrate in spaced positions so that the generally planar members of the fasteners lie against the exposed face of the first material, a lattice-like element is applied to the fasteners by fastening the lattice-like element to the projections of the fasteners, and a layer of a second material is applied to cover the lattice-like eiement, the fasteners and the layer of the first material.