WO2007053900A1

WO2007053900A1 - Preformed patch assembly for repairing holes in structural panels

Info

Publication number: WO2007053900A1
Application number: PCT/AU2006/001683
Authority: WO
Inventors: Paul Michael Cocker; Ian Raymond Cocker
Original assignee: Paul Michael Cocker; Ian Raymond Cocker
Priority date: 2005-11-10
Filing date: 2006-11-10
Publication date: 2007-05-18

Abstract

A preformed patch assembly (10) for repairing or sealing a hole in a structural panel, such as a plasterboard wall, includes an unhardened plaster layer (12) and a strengthening patch (14) on an inner surface of the unhardened plaster layer. The strengthening patch is smaller in area than the unhardened plaster layer and is adapted to cover the hole. The inner surface of the unhardened plaster layer is adapted to harden and set against the surface of the structural panel surrounding the hole when exposed to air for a sufficient period of time. The preformed patch assembly may further include a cover plate (16) over an outer surface of the unhardened plaster layer. The cover plate is adapted to be removed from the outer surface of the plaster layer when it has hardened and set against the surface of the structural panel surrounding the hole.

Description

PREFORMED PATCH ASSEMBLY FOR REPAIRING HOLES IN STRUCTURAL PANELS

FIELD OF THE INVENTION

The present invention relates to a preformed patch assembly for repairing or sealing holes in walls, ceilings, and other structural panels or sheet members, and to a method for repairing or sealing holes in such panels which utilizes said preformed patch assembly.

Although the invention will hereinafter be described with reference to its application to repairing holes in dry wall panels of buildings, it will be understood by persons skilled in the art that the invention is not limited thereto, but has wider application to repairing or sealing holes in all kinds of structural panels or sheet members, such as ceilings, partitions, and doors, and that may be made of plasterboard or of a gypsum based sheet material.

BACKGROUND OF THE INVENTION

Any discussion of the prior art in this specification is not to be taken as an admission that such prior art forms part of the common general knowledge in this field.

Dry wall panels consist of a thin layer of gypsum sandwiched between two layers of heavy paper board. It is commonly used in residential buildings to form or line the inner walls and ceilings. Plasterboard panels, too, are frequently used for this purpose, and consist of two boards which sandwich between them a thin layer of plaster.

Whilst the patching of very small holes in such structural panels can relatively easily be achieved by filling the holes with plaster or other putty- like patching or jointing compound, the patching of larger holes presents a problem in that the patching compound will slide down or sink into the hole, and may shrink either by evaporation of some of its water content into the surrounding air or by absorption into the porous (if unpainted) material of the structural panel. Any of these responses during the hardening and setting of the patching compound may prevent it from adhering properly to the edges of the hole or create a dished surface of the patch when set. Sometimes, as a preventative measure, backing material is used to initially bridge the hole so that the patching compound will remain sufficiently in place while it hardens and sets. However, such backing material is temporary and does not form a permanent structural part of the patch formed after the patching compound has set.

Alternatively, a very large amount of patching compound may be used to prevent unevenness in the patch surface, but this will require heavy sanding back of the raised surface of the patch when set, and so is labour intensive, time consuming, and wasteful of patching compound. Various methods and devices for repairing or sealing holes in structural panels have been disclosed in the prior art.

For example, US Patent Application Publication No. 2002/0102381 discloses a patch for repairing drywall panels of walls and ceilings that includes a backing member and a plug secured to, and protruding from, the backing member. The plug is of a shape to substantially fill in a generally circular hole which is deliberately cut out of the wall or ceiling in an area surrounding a smaller hole that is to be repaired.

US Patent No. 5,018,331 discloses a device for the repair of holes in drywall panel walls where the device is positioned as a backing behind the hole and temporarily secured thereto. The device includes a hinged circular plate which can be folded in half to permit its insertion through the hole, and pulling straps connected to each half for securing the device to locations on the outer surface of the wall.

US Patent No. 3,874,505 discloses a wall crevice repair kit having a rigid backboard and a preformed sheet rock patch affixed to one face thereof. The patch has a smaller area than the backboard so as to define a border around the patch. A pressure sensitive adhesive is carried on the border. A cut through the patch is aligned with a score line in the backboard to allow the patch and backboard to fold in half and be inserted through a hole which is deliberately cut out of the wall in an area surrounding the crevice to be repaired, the area of the cut out hole being substantially equal to that of the patch. Pull strings are used to locate the patch in the cut out hole so that the patch sits flush with, and snugly within, the facing wall surface. Plaster is then applied to seal the patch to the wall.

US Patent No. 5,620,768 discloses a multi-layer repair patch for drywall panels and automobile bodies, comprising an inner mesh, a middle reinforcing sheet which may be perforated, and an outer mesh. The inner surfaces of both the inner and outer mesh cany an adhesive coating. The inner mesh is attached to the surface under repair, and the outer mesh secures the middle sheet to the inner mesh. Patching compound can then be applied over the patch and will both cover the patch and migrate therethrough to fill the hole of the surface under repair, before setting hard thereto.

US Patent No. 5,518,565 discloses an apparatus for repairing a hole in a generally planar sheet material, comprising a repair assembly for coplanar insertion into the hole, and an "injector gun" type of actuating mechanism both for moving an outer periphery of the repair assembly between withdrawn and extended positions within the hole and for causing discharge from the repair assembly of patching compound to fill the hole.

US Patent No. 4,959,251 discloses an elastic, outwardly tapered, patch for the repair of a hole in an interior wall, and has pressure sensitive adhesive backing which can be affixed to the wall surrounding the hole. US Patent Application Publication No. 2003/0126819 discloses a thin sheet patch for repairing a hole in a wall, and has a strengthened lower sheet for adhesion to the wall surrounding the hole, and an upper sheet for adhesion to the wall surrounding the periphery of the lower sheet. The upper sheet has an irregularly corrugated edge and an upper surface that is of a similar texture to the wall.

US Patent No. 6,607,621 discloses a single sheet patch for repairing a hole in a wall, and has an adhesive lower surface for affixing the patch to the wall surrounding the hole, and an upper surface that is textured to match that of the wall. The patch is made from a biaxially oriented three-ply polypropylene film.

Whilst the aforementioned prior art may, to a greater or lesser extent, result in the patching or sealing of a hole in a wall or other structural panel, they are either too structurally complex and hence difficult to use and expensive to purchase, or too weak or temporary to provide any effective long term patching of the hole.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome or substantially ameliorate the disadvantages and shortcomings of the aforementioned prior art, or at least provide a useful alternative. It is a preferred object of the present invention to provide a preformed patch assembly of any suitable size for repairing or sealing a hole in a structural panel that, in use, includes an unhardened plaster layer, a strengthening patch on an inner surface thereof and that can cover the hole, and a temporary cover plate over an outer surface thereof for use in applying and supporting the plaster layer and strengthening patch over the hole until the plaster layer has hardened and set, the preformed patch assembly being ^• protected against premature hardening of the plaster layer by air tight sealing means.

According to one aspect of the invention, there is provided a preformed patch assembly for repairing or sealing a hole in a structural panel, including:

(a) an unhardened plaster layer, and

(b) a strengthening patch on an inner surface of the unhardened plaster layer, wherein the strengthening patch is smaller in area than the unhardened plaster layer and is adapted to cover the hole, the inner surface of the unhardened plaster layer being adapted to harden and set against the surface of the structural panel surrounding the hole when exposed to air for a sufficient period of time.

According to another aspect of the invention, the preformed patch assembly described above further includes a cover plate over an outer surface of the unhardened plaster layer, the cover plate being adapted to be removed from the outer surface of the plaster layer when it has hardened and set against the surface of the structural panel surrounding the hole.

Preferably, the strengthening patch has apertures for receiving plaster therein, such as a mesh or apertured fiberglass disc.

The cover plate may be perforated.

Preferably, the cover plate is made of a hard plastic material, which may be polyethylene, polypropylene, polyurethane or a polycarbonate.

It is preferred that the cover plate is larger in area than the unhardened plaster layer.

The centre of the cover plate may be slightly domed or concavely facing the plaster layer.

In a preferred form, the cover plate has perforations which are generally the size of pin holes for the passage of air therethrough.

According to yet another aspect of the invention, the preformed patch assembly described above further includes air tight means that sealingly wraps the unhardened plaster layer, strengthening patch, and cover plate for, protection against premature hardening of the plaster layer. Preferably, the air tight means comprises first and second air impermeable plastic sheets that sandwich the unhardened plaster layer, strengthening patch and cover plate, the first and second sheets being sealed together along peripheral regions thereof.

The unhardened plaster layer, strengthening patch, and cover plate may be any shape, such as rectangular, circular or square, and share a generally common centre point.

SUMMARY OF THE DRAWINGS

Fig. 1 is a perspective view of a preformed patch assembly according to a first embodiment of the present invention.

Fig. 2 is a side sectional view through H-II of the assembly of Fig. 1.

Fig. 3 is a perspective view of a preformed patch assembly according to a second embodiment of the present invention.

Fig. 4 is a side sectional view through IV-IV of the assembly of Fig. 3.

Fig. 5 is a perspective view of the preformed patch assembly being applied over a hole in a plasterboard wall. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The preformed patch assembly 10 shown in Figs. 1 and 2 is used for repairing a hole in a. dry wall panel and comprises an unhardened plaster layer 12 and a strengthening patch in the form of a mesh 14 on an inner surface of the layer 12. The inner surface is adapted to abut against the panel surrounding the hole. The mesh 14 is smaller in area than the unhardened plaster layer and is adapted to cover the hole. The plaster layer 12 is adapted to harden so that its inner surface will set against the surface of the panel suiTOunding the hole when exposed to air for a sufficient period of time. The plaster layer is tapered outwardly, being of greater thickness at its centre than at its radial periphery. The mesh is gauze-like and is made of fibreglass.

For the purposes of applying and supporting the plaster layer and mesh over the hole until the plaster layer has hardened and set, there is a perforated plastic cover plate 16 over an outer surface of the unhardened plaster layer. The perforated plastic cover plate 16 is adapted to be removed from the outer surface of the plaster layer when it has hardened and set.

The perforated plastic cover plate 16 is made, in this embodiment, of polyethylene, and is larger in area than the unhardened plaster layer 12. The centre of the perforated cover plate 16 is slightly domed to accommodate the greater thickness of the plaster layer at its centre. There are pin hole sized perforations 17 through the cover plate 16 for the passage of air. In this embodiment, the unhardened plaster layer 12 and the mesh 14 are circular in shape, and the perforated cover plate 16 is generally square in shape, although they can be any shape in which they share a generally common centre point.

For the purpose of protecting the preformed patch assembly 10 against premature hardening of the plaster layer, an air tight seal is provided for the preformed patch assembly by a film of first and second plastic sheets 20,22 that sealingly envelope or sandwich the unhardened plaster layer 12, mesh 14 and perforated cover plate 16. The first and second sheets 20,22 are sealed together along peripheral regions thereof by adhesive that, say, allows for the peeling away of one sheet from another when required, or by heat sealing the plastic peripheral regions together.

The preformed patch assembly shown in Fig. 2 is utilized as follows. The second sheet 22 is peeled away, and the inner surface of the unhardened plaster layer 12 is applied and supported over a hole in a dry wall panel, so that the mesh 14 covers the hole and the plaster layer can harden and set against the surface of the panel surrounding the hole. Application of hand pressure against the perforated cover panel 16 allows some unhardened plaster to penetrate through the apertures in the mesh and adhere to the surface of the panel surrounding the hole. The mesh thus assists the plaster layer to grip against the panel surface. The mesh also inhibits any sinking of the plaster layer into the hole, and strengthens the plaster layer at its centre where it has no rearward contact with the panel. The first sheet 20 is then peeled away and the unhardened plaster is subject to exposure to air for about 24 hours by passage of air through the perforations 17 in the cover plate. This is sufficient to allow the plaster layer to harden and set against the surface of the panel surrounding the hole. The perforated cover plate is then removed, and the hardened plaster is sanded back to assume an acceptable surface texture and appearance. This may involve "feathering" the radial periphery of the plaster to the surrounding panel surface, and leveling any raised or irregular regions. Should the sanding of the plaster inadvertently lead to the exposure of the mesh, the mesh itself is made of a sandable fibreglass material and will not interrupt the desired smooth surface of the resulting plaster patch. Once sanded, the plaster patch and surrounding wall panel are painted to visually conceal the location of the plaster patch.

The preformed patch assembly 30 shown in Figs. 3, 4 and 5 is adapted to be used in a similar manner to the assembly 10, but comprises an unhardened plaster layer 32 and a strengthening patch in the form of an apertured fiberglass disc 34 on an inner surface of the layer 32. The disc 34 is smaller in area than the unhardened plaster layer 32, which is tapered outwardly. Over an outer surface of the unhardened plaster layer 32 is a plastic sleeve 36, such as a thin polyurethane film or sheet, which is sandwiched between the layer 32 and a cover plate 38. The cover plate 38 is slightly concave as it faces the plaster layer 32 to accommodate the greater thickness of the plaster layer at its centre than at its radial periphery. The cover plate 38 is made, in this embodiment, of a stiff polyurethane and can be removed from the outer surface of the plaster layer when, or even before, it has hardened and set. Each of the unhardened plaster layer 32, disc 34, and cover plate 38 are, in this embodiment, circular in shape.

Although not shown, the plastic sleeve 36 may be temporarily held tightly against the rim or the inner surface of the cover plate 38 by suitable means to ensure that the plastic sleeve (which supports the plaster layer and the disc thereon) does not slip away from the cover plate 38 inappropriately. Also, there may be a very thin plastic film covering the inner surface of the unhardened plaster layer and the disc to prevent sticking with any bag in which the assembly is sealingly stored. An air tight seal is provided around the preformed patch assembly 30 by first and second plastic sheets 40, 42 that sealingly envelope the assembly along heat sealed peripheral regions 44. The sealed bag formed in this way has preferably been evacuated of air by a vacuum sealing device. The sealed bag can be opened to access the preformed patch assembly 30, when required for use, by cutting the sheets 40, 42 along an edge thereof.

A possible process for forming the apertured fiberglass disc 34 is as follows. A sheet of fiberglass mesh of no more than about 0.5mm in thickness and having right angle intersecting fibers or strands is cut to form a disc of a suitable size and shape. A fiberglass resin mixed with a hardener (catalyst) is applied to both sides of the disc and allowed to harden thereon so as to strengthen the disc. Alternatively, cutting to form a disc may be carried out as a next step, rather than before the mixture of resin and hardener is applied to the disc. Aperture are then formed through the hardened fiberglass disc of, say, about 1 to 3 mm diameter and about 5 to 10 mm apart, so as to allow, in use, unhardened plaster to flow therein. The disc can now be assembled with the other components needed to form the preformed patch assembly 30.

In use, the preformed patch assembly 30 is removed from its airtight sealed bag and orientated so that the inner surface of the unhardened plaster layer and strengthening patch face the hole in the structural panel, such as a plasterboard wall, needing repair (see Fig. 5). If present, the very thin plastic film is removed from over the plaster layer and strengthening patch, and the assembly is then pressed against the wall so that the strengthening patch covers the hole and the unhardened plaster layer sticks or affixes against the surface of the wall surrounding the hole. The plaster is then allowed to harden and set against the surface with exposure to air for a sufficient period of time,- During or at completion of hardening of the plaster layer, the cover plate may be removed, followed by removal, when desired, of the plastic sleeve. The hardened plaster patch so formed is sanded back to assume an acceptable surface texture and appearance, after which the patch may be painted over.

It will be readily apparent to persons skilled in the art that various modifications may be made in details of design and construction of the preformed patch assembly described above without departing from the scope or ambit of the present invention.

Claims

CLAIMS:

1. A preformed patch assembly for repairing or sealing a hole in a structural panel, including:

(a) an unhardened plaster layer, and

(b)a strengthening patch on an inner surface of the unhardened plaster layer, wherein the strengthening patch is smaller in area than the unhardened plaster layer and is adapted to cover the hole, the inner surface of the unhardened plaster layer being adapted to harden and set against the surface of the structural panel surrounding the hole when exposed to air for a sufficient period of time.

2. The preformed patch assembly of claim 1 and further including a cover plate over an outer surface of the unhardened plaster layer, the cover plate being adapted to be removed from the outer surface of the plaster layer when it has hardened and set against the surface of the structural panel surrounding the hole.

3. The preformed patch assembly of claim 1 wherein the strengthening patch has apertures for receiving plaster therein.

4. The preformed patch assembly of claim 3 wherein the strengthening disc is an apertured fiberglass disc.

5. The preformed patch assembly of claim 1 wherein the cover plate is perforated.

6. The preformed patch assembly of claim 5 wherein the cover plate is made of a hard plastic material selected from the group consisting of polyethylene, polypropylene, polyurethane and a polycarbonate.

7. The preformed patch assembly of claim 2 wherein the cover plate is larger in area than the unhardened plaster layer.

8. The preformed patch assembly of claim 2 wherein a central region of the cover plate is domed or concavely facing the plaster layer.

9. The preformed patch assembly of claim 2 wherein the cover plate has perforations for the passage of air therethrough.

10. The preformed patch assembly of claim 1 and further including an air tight means that sealingly envelopes the unhardened plaster layer, strengthening patch, and cover plate for protection against premature hardening of the plaster layer.