GB2056523A - A device for aiding the production of surface finishes - Google Patents

Abstract

A device for aiding the production of surface finishes comprises a flexible, synthetic plastics strip 11 which is of an angle section and which is formed with an integral ridge 13 extending along the apex of the strip. Each limb 12 of the strip 11 is formed with apertures 15 therein for receiving the finishing material, for example plaster or cement. The device may be used on wall corners around arches or for levelling floors or walls. <IMAGE>

Description

SPECIFICATION A device for aiding the production of surface finishes This invention relates to a device for aiding the production of surface finishes particularly, but not exclusively, plaster coatings.

When plastering up to a corner defined between two mutually perpendicular walls, it is normal to secure an angle section strip over the corner so as to facilitate production of an even plaster layer at the corner. The strip is arranged so that when secured over the corner its apex projects from the surfaces of the two walls by an amount corresponding to the required thickness of the plaster coating. Moreover, each limb of the strip includes an open lattice structure so that the plaster can enter the interstices in the lattice to ensure a key between the plaster and the strip. For many years, strips of this kind have been formed of iron or an iron-based material with the strip being scherardised to inhibit corrosion.

However, the use of these materials leads to a number of serious disadvantages. Thus the scherardised coating is easily damaged so that the strip is then liable to rust which in turn can lead to discolouration of any plaster in contact with the strip. In addition, the strip is difficult to bend into any given shape and bending also tends to damage the scherardised coating. Further, if the strip is accidentally deformed, then it is difficult to return to its original shape. In view of its lack of flexibility, the strip is necessarily supplied in standard lengths, normally of 8 feet, which are difficult to store and to butt together without the join being visible in the plaster coating. Moreover, cutting the standard length strips to size requires the use of a hacksaw and any unused material after cutting a strip to size tends to be wasted.

An object of the present invention is therefore to provide an improved device for aiding the production of surface finishes.

Accordingly, the invention resides in a device for aiding the production of surface finishes comprising a flexible, synthetic plastics strip which is of an angle section and which is formed with an integral ridge extending along the apex ofthe strip, each limb of the strip being formed with apertures therein.

The device described in the preceding paragraph exhibits the advantages that the strip can be manufactured more cheaply than its metal counterpart, is not subject to rusting, and can readily be bent to any desired shape without becoming permanently deformed. Moreover, in view of its flexibility, the strip can be supplied as a roll in which the limbs of the strip are flexed to a generally planar configuration. This facilitates storage and efficient utilization ofthe strip, while cutting to size can readily be effected with, for example a knife or pair of shears.

Preferably, the strip is produced by extrusion, conveniently in polyvinyl chloride.

Preferably, each limb ofthe strip is provided with a strengthening rib.

Conveniently, the ridge defines part of a decorative portion of the strip which, when the strip is mounted in a wall, is exposed to define a decorative surface finish for the wall.

In the accompanying drawings: Figure 1 is a sectional view of a device according to a first example of the invention, Figure 2 is a perspective view of a device according to a modification of said first example, Figure 3 is a diagrammatic illustration of the device shown in Figure 2 when used to assist plastering around an archway, Figure 4 illustrates the use of the device of the first example in producing a cement screed floor layer, Figure 5 is a perspective view of a device according to a second example of the invention, Figure 6 is a sectional view of a wall to which a plurality of devices shown in Figure 5 have been secured to assist in plastering the wall, and Figure 7 is a sectional view of a device according to a third example of the invention.

Referring to Figure 1, the device of the first example includes an extruded flexible strip 11 composed of polyvinyl chloride or other suitable thermoplastics material, such as polyethylene or polypropylene. The strip 11 is of an angle section with the included angle defined between the limbs 12 of the strip being between 45" and 135 , preferably 90". Extending along the apex of the strip is a hollow, outwardly projecting ridge 13, which is of generally U-configuration and the height of which determines the thickness of the plaster coating to be applied to an associated wall. Each limb 12 is blanked to define a plurality of apertures (not shown) which, in use, provide a key for the plaster and extending along the outer surface of each limb is a strengthening rib 14.Typically the strip has a thickness of 1 mm, each limb 12 has a width of 45mm, the ridge 13 has a height of 10mm and each rib 14 has a height of 1mm.

Referring to Figure 2, the strip 11 of this modification is similar to that shown in Figure 1 and it will be seen that each limb 12 is provided with arrowshaped apertures 15 to provide a key for the plaster.

Further, generally circular apertures 16 are provided in each limb to enable the strip to be secured to a wall. As shown in Figure 3, the device of this modification is particularly intended to assist in plastering around a curved interface between two walls, for example an archway, and hence the outermost edges of each limb 12 are formed with a plurality of notches 17, conveniently of V-configuration to assist longitudinal deformation of the strip.

As shown in Figure 4, the strip 11 of the first example or said modification can also be used to assist in producing a level, cement screed layer over a concrete floor. In this case a plurality of strips 11 are secured to the floor at transversely spaced intervals, conveniently by setting the strips into the concrete before it hardens. Then, laying a straight edge across the strips indicates the level of the cement screed required to produce an even thickness layer over the floor. With this arrangement, it is also possible to use the space between each strip 11 and the concrete floor as a duct for receiving a gas pipe, water pipe or the like.

Referring to Figures 5 and 6, the device of the second example includes a strip 21 which is of similar configuration to the strip 11 shown in Figure 1, except that the limbs of the strip 21 are provided at their outermost edges with longitudinally extending, outwardly projecting flanges 22. When strip is in its unflexed condition, the flanges 22 are substantially coplanar and subtend equal angles with their respective limbs. The flanges 22 may be apertured and permit the strip 21 to be secured to the major surface of a wall to be plastered so as to allow bulges and/or depressions in the wall to be removed during plastering.As shown in Figure 6, this is effected by securing a plurality of strips 21 at spaced positions along the wall such that, where necessary, one or more ofthe strips is flattened from its normal configuration to decrease the distance by which the strip projects from the wall. By suitable arrangement of the strips, it is possible to ensure that the ridges defined at the apices of the strips lie in a common vertical plane so that plastering up to the ridges produces a planar, vertical plaster surface.

Referring to Figure 7, the device of the third example defines a decorative corner moulding and includes an angle section synthetic resin strip 31 provided with a hollow part-cylindrical ridge 32 extending along the apex of the strip. In addition, the strip 31 includes a pair of longitudinally extending projections 33 which are positioned on opposite sides respectively of the ridge 32 and which define with the ridge 32 a decorative portion 34 of the strip.

When the strip is mounted on a wall, the portion 34 is exposed to define a decorative surface finish for the wall. Since the portion 34 is required for decorative purposes, it is imperforate, but apertures 35 are formed adjacent the outermost edges of the strip. The apertured edge region of each limb is separated from the decorative portion 34 by an integral rib 36 extending along the outer surface of the limb. In addition, the strip includes inwardly projecting curved tags 37 at the outermost edge of each limb and adjacent the apex of the strip: In use, to mount the decorative moulding strip 31 over a corner of a wall, a first layer 37 of plaster is applied to the brickwork and then, before the plaster is dry, the strip 31 is pushed over the corner so that the tags 37 bite into the plasterto secure the strip in place. A second, plaster finishing layer 39 can then be applied to the layer 38 over the outermost edges of the strip 31 up to the ribs 36. The plaster layer 39 thereby enters the apertures 35 to aid the key between the plaster and the strip 31. The portion 34 of the strip is left exposed to provide the required decorative finish.

In practice, each of the strips shown in the drawings would be stored in rolls with the limbs of the strip being flattened so as to be substantially coplanar. In this way, cutting of the strip to length can be achieved without wastage, and storage of the strip is facilitated.

Claims (7)

1. A device for aiding the production of surface finishes comprising a flexible, synthetic plastics strip which is of an angle section and which is formed with an integral ridge extending along the apex of the strip, each limb of the strip being formed with apertures therein.

2. A device as claimed in Claim 1, wherein the strip is produced by an extrusion operation.

3. A device as claimed in Claim 1 or Claim 2, wherein the strip is formed of polyvinyl chloride.

4. A device as claimed in any preceding Claim, wherein each limb ofthe strip is provided with a strengthening rib

5. A device as claimed irf any preceding Claim, wherein the ridge defines part of a decorative portion of the strip which,when the strip is mounted in a wall, is exposed to define a decorative surface finish for the wall.

6. A device as claim-ed'in Claim 1, substantially as hereinbefore describedwith reference to, and as shown in any one of Figure, 2,5 and 7 ofthe accompanying drawings.

7. A method of producinga surface finish using a device as claimed in any preceding Claim, and substantially as hereinbefore described with reference to, and as shown in, any one of Figures 3,4, 5 and 7 of the accompanying drawings