GB2342877A

GB2342877A - Repairing holes in sheets of material (plasterboard)

Info

Publication number: GB2342877A
Application number: GB9823167A
Authority: GB
Inventors: Neil Michael Bett
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-10-22
Filing date: 1998-10-22
Publication date: 2000-04-26
Also published as: GB9823167D0

Abstract

A device 5 for forming a tapered edge 4 around a hole 2 in a sheet of material 1 comprising a conical cutter slideably received in a support. When the support is placed in contact with the sheet of material about the hole 2 and the conical cutter is rotated relative to the support about its axis of rotation and moved substantially in an axial direction towards and into the hole 2, the cutter cuts a tapered edge 4 around said hole 2. Also disclosed is a method involving making the hole, fitting a plug and plastering or rendering over it.

Description

Device and Method of Filling a Hole in a Sheet of Material The present invention relates to a device used in a method of filling holes in a sheet of material typically used in the construction of cavity walls and ceilings. The invention also relates to the method in which the device is used.

When a building is constructed, interior walls and ceilings are usually faced with plasterboard to provide a flat surface to which plaster and/or wallpaper can be applied. The plasterboard is positioned with an airspace between it and the interior wall to prevent the egress of damp into the building and to enhance its heat insulating and sound proofing properties. The airspace between the plasterboard and the wall or ceiling also provides a convenient conduit for the passage of electrical wiring and pipework which is routed through the building to supply electrical power and heating to each room.

During construction, holes are made in plasterboard to enable, for example, light switches, plug sockets or light fittings to be installed. When modifications or alterations to the building are subsequently carried out, it is often desirable to reinstall light switches, plug sockets or light fittings in a more appropriate location so the unwanted hole has to be filled with plaster to render it invisible.

A problem with filling holes in plasterboard is that the plaster has to be applied onto some form of supporting surface otherwise it just falls into the airspace between the wall and the plasterboard. To overcome this problem, it is common practice to stuff the airspace behind the hole with newspaper or such like to provide a surface onto which the plaster can be applied. However, this method is very crude and the plaster still often fails to adhere to the newspaper resulting in considerable wastage as it falls into the cavity and onto the floor, making a mess. This problem particularly occurs when attempting to fill a hole in a ceiling.

Furthermore, it is essential to mix the plaster to exactly the right consistency and viscosity otherwise the problems of ensuring that it sticks or keys to the newspaper are exacerbated. Additionally, a considerable amount of plaster has to be used to completely fill the hole and to render it up to the level of the surrounding plasterboard.

It is an object of the present invention to substantially alleviate or overcome the aforementioned problems discussed above.

According to the present invention, there is provided a device for forming a tapered edge around a hole in a sheet of material comprising a conical cutter mounted on a support, the cutter being rotatable about its axis of rotation and slideable in an axial direction relative to the support, the arrangement being such that the cutter cuts a tapered edge around the hole when the support is held against the sheet of material about the hole and the cutter is rotated about said axis and moved in said axial direction towards and into the hole.

In a preferred embodiment, the cutter includes a cylindrical shank slideably received in a bearing on the support.

A collar is preferably slideably received on the shank and includes means to enable the collar to be fixed to the shank at any position along its length.

A plurality of grooves or markings can conveniently be provided on the surface of the shank, each groove or marking corresponding to a predetermined depth of cut, the collar means being positionable adjacent a selected groove or marking such that when the selected depth of cut has been reached, the collar means contacts the support preventing further movement of the conical cutter in an axial direction towards and into the hole.

Preferably, the support comprises a frame including a backplate and a ring shaped faceplate spaced from the backplate.

The cutter preferably comprises at least one cutting blade, the or each cutting blade having a cutting edge.

Preferably, the device includes a conical body, the cutting blade being mounted in a recess in the conical body.

In one embodiment, the conical body is truncated.

The present invention also provides a method of filling a hole in a sheet of material comprising the steps of: a) forming a tapered surface around said hole using a device according to the invention ; b) inserting a tapered plug into the hole such that it seats against the tapered edge, the plug being dimensioned so that its outside face lies at or below the level of the front face of the sheet of material; and c) plastering or rendering over the plug.

Preferably, step (a) includes the step of making the hole circular whilst forming the tapered edge.

In a preferred embodiment, the method includes the step of applying a coating of plaster to the edge of the hole and/or tapered plug before inserting the plug into the hole.

The present invention also provides a plug used in the method, comprising a conical body with a tapered curved edge insertable into a hole in a sheet of material so that its outside face lies below the level of the front face of the sheet of material.

FIGURE 1 illustrates a cross-sectional view of a hole in a portion of a sheet of plasterboard; FIGURE 2 illustrates the conical body portion of the device of the present invention being inserted into the hole in the sheet of plasterboard illustrated in Figure 1 to taper the edge of the hole, the support and shank being omitted for the purpose of clarity; FIGURE 3 illustrates the plug being inserted into the hole in the sheet of plasterboard after the device has been used to taper the edges of the hole as shown in Figure 2; FIGURE 4 illustrates the plug seated in the hole in the sheet of plasterboard illustrated in Figure 1; FIGURE 5 illustrates a perspective view from above of the conical body of the device used to taper the edges of the hole in a sheet of plasterboard, as shown in Figure 2, FIGURE 6 illustrates a side view of the conical body portion of the device shown in Figure 5 in which only a portion of the shank is illustrated; FIGURE 7 illustrates a side view of the complete device in a first retracted position, and FIGURE 8 illustrates a side view of the complete device shown in Figure 7 in a second forward position.

Referring now to the drawings, the method of the invention will first be described with reference to Figures 1 to 4.

A portion of a sheet of plasterboard 1 forming part of a cavity wall or ceiling of a building is shown in Figure 1 and has a hole 2 therein in which a light switch or plug socket was originally mounted, and which is now to be filled. The hole 2 may initially be square, round or irregularly shaped.

The first step in the method is illustrated in Figure 2. The hole 2 is made round and a taper cut in the edge 4 of the hole 2 using the device 5 of the present invention, the operation and construction of which is explained in more detail later.

When the hole 2 has been made round and the taper has been cut, the device 5 is withdrawn from the hole 2 and a plug 6, which in the preferred embodiment in the shape of a truncated cone and is made from plasterboard, but could also be made from some other material such as plastics or fibre, is inserted into the tapered hole such that the curved face 7 of the plug 6 seats against the tapered curved edge 4 of the hole 2. The plasterboard is then rendered by applying plaster over the plug, which may be recessed in the hole compared with the front face 8 of the plasterboard, to retain the plug 6 in the hole and provide a smooth surface for the application of wallpaper and paint. If necessary, and particularly when filling a hole in a ceiling, a layer of plaster can be applied to the edge 4 of the hole 2 and/or the edge 7 of the plug 6 so that when the plug 6 is inserted into the hole and the edges 4,7 come into contact, the plug 6 does not fall out of the hole 2 before the plasterboard and plug 6 is rendered.

The construction of the device 5 for cutting a taper in the edge 4 of the hole 2 in the sheet of plasterboard will now be described with reference to Figures 5 to 8.

The device 5 includes a conical body 8 having a flat circular base 10. The conical body 8 tapers towards an apex 12 at a preferred angle relative to the base 10 of 45 degrees.

The conical body 8 has three elongate recesses 13 formed in the curved face 15 extending from the base 10 and terminating at the apex 12. Each recess accommodates a cutting blade (not shown) each of which is attachable to the body 8 by means of a pair of screws (not shown) which extend through the cutting blade into a pair of threaded holes 14 in each recess 13. The cutting blades are disposed so that their cutting edges protrude from the curved face 15 of the body 8 and are angled such that the cutting edge points in the direction of rotation of the device 5.

The preferred embodiment has three cutting blades equally spaced by 120 degrees about the conical body 8. Three blades are considered to be the optimum number as it improves stability during use resulting in a smoother cut. It will be appreciated, however that any other number of blades can effectively be used. In addition, the blade or blades may be helical.

In an alternative embodiment, the body part may be truncated to form a frustoconical shaped body.

The body 8 includes a cylindrical shank 20 extending therefrom which terminates in a cylindrical stem 9. The shank 20 is formed integrally with, and has a greater diameter than, the cylindrical stem 9. A number of spaced parallel grooves or markings 21 are provided on the surface of the shank 20, the reasons for which will become apparent.

A collar 22 is slideably received on the shank 20 and a grub screw 23 is threadingly received in a hole in the collar which engages the surface of the shank 20 when fully tightened to retain the collar in a selected fixed position on the shank 20.

The body 8 is located within a support frame 24. The frame comprises a backplate 25 to which is mounted a grip 26. The shank 20 passes through the grip 26 and a bearing (not shown) located in an opening in the backplate 25 to enable the body to rotate freely relative to the frame 24 and slide in a direction indicated by the arrow A.

A faceplate 27 is located spaced from and parallel to the backplate 25 on legs 28. In the illustrated embodiment, there are four legs 28, only three of which are visible, although it will be appreciated that any number of legs 28 could be used instead. The legs 28 are of a length which ensures that the body 8 is fully located within the frame with its apex 12 situated just behind the front surface 29 of the faceplate when the body 8 is in its fully retracted position in the frame, as illustrated in Figure 7.

The faceplate 27 is ring shaped so that the body 8 can pass through the ring when the shank is slid through the backplate 25 in the direction of arrow A to a second forward position such as that illustrated in Figure 8. A number of protrusions or short spikes 30 are spaced circumferentially about the front surface 29 of the faceplate 27.

The frame 24 can also include a separate removable dust shield (not shown) which comprises a tubular cover that surrounds the frame 24 between the backplate 25 and faceplate 27. The shield is preferably made from a transparent material. The dust shield also functions as a safety guard to prevent the user from inadvertently placing a finger near the conical body portion 8 whilst it is rotating.

In an alternative construction, the legs 28 can be replaced with an enclosed tubular surround that supports the faceplate 27 and acts as a dust and safety shield. The surround can be integrally formed with either or both of the backplate 25 and faceplate 27.

Operation of the device will now be described. Each of the grooves or markings on the shank 20 correspond to a different depth of cut. Once the required depth has been determined, the collar 22 is slid along the shank 20 to position it directly adjacent to the groove corresponding to the chosen depth. Once in position, further movement of the collar can be prevented by tightening the grub screw 23 in the collar 22 against the shank 20. Figure 7 and 8 illustrate the position of the collar 22 when the maximum possible depth of cut is required.

The cylindrical stem 9 is now mounted in the chuck of a drill and the faceplate 27 brought into contact with the sheet of plasterboard so that it surrounds the hole therein. The short spikes 30 protruding from the front surface 29 of the faceplate 27 engage the plasterboard and serve to locate and prevent movement of the frame during the cutting operation. The drill is then switched on to rotate the conical body portion 8 within the frame 24 and pressure is applied to the drill to urge it in an axial direction as, shown by arrow A, so that the body 8 engages the plasterboard and tapers the hole 2.

To assist in preventing movement of the frame 24 and to steady it during the cutting operation, the user places the fingers of one hand around the grip 26.

As can be seen from Figure 8, the collar 22 contacts the grip 26 when the selected depth of cut has been reached and prevents further insertion of the body 8 into the hole in the sheet of plasterboard.

It will be appreciated from the foregoing, that the support frame 24 ensures that the body 8 is only inserted into the hole to a depth sufficient to cut the desired taper and prevents over enlargement of the hole. The frame 24 also acts as a guide to assist in positioning the body 8 accurately and to keep it steady during the cutting operation.

If a shield is provided, this collets the dust generated during cutting and also acts as a safety guard to prevent injury.

The device 5 is preferably made out of a non-metallic material and is most preferably made from a plastics material, although the removable and replaceable blades are made from metal, such as steel.

One device 5 can be used with a large number of differently sized holes. However, it will be appreciated that the overall size of the hole must be such that the blades of the cutting means engage the edge of the hole when inserted therein. Therefore a range of devices of different sizes may be provided.

Similarly, a range of different size plugs 6 will be required to accommodate different sizes of hole in the sheet of plasterboard.

Although in the preferred embodiment, the method and device are used to fill holes in plasterboard, it will be appreciated that the method and device can be used to fill holes in other sheet materials often used in the construction industry.

It will be appreciated from the foregoing that the plug 6 cannot fall into the cavity because it is seated against the tapered edge of the hole 2. Plaster can then be easily applied onto the plug 6 thereby avoiding wastage. Furthermore, as the plug fills the majority of the hole, the amount of plaster required to complete the job is substantially reduced.

Claims

Claims 1. A device for forming a tapered edge around a hole in a sheet of material comprising a conical cutter mounted on a support, the cutter being rotatable about its axis of rotation and slideable in an axial direction relative to the support, the arrangement being such that the cutter cuts a tapered edge around the hole when the support is held against the sheet of material about the hole and the cutter is rotated about said axis and moved in said axial direction towards and into the hole.
2. A device according to claim 1, wherein the conical cutter includes a cylindrical shank slideably received in a bearing in the support.
3. A device according to claim 2, wherein a collar is slideably received on the shank.
4. A device according to claim 3, wherein the collar includes means to enable the collar to be fixed to the shank at any position along its length.
5. A device according to claim 4, wherein a plurality of grooves or markings are provided on the surface of the shank, each groove or marking corresponding to a predetermined depth of cut, the collar means being positionable adjacent a selected groove or marking such that when the device is in use and the selected depth of cut has been reached, the collar means contacts the support preventing further movement of the conical cutter in an axial direction towards and into the hole.
6. A device according to any preceding claim, wherein the support comprises a frame.
7. A device according to claim 6, wherein the frame includes a backplate and a ring shaped faceplate spaced from the backplate.
8. A device according to claim 7, wherein a gripping ring is mounted on the backplate.
9. A device according to claim 7 or 8, wherein a plurality of protrusions extend from the surface of the faceplate.
10. A device according to any preceding claim, wherein a shield or cover encloses the support.
11. A device according to claim 10, wherein the shield is removable.
12. A device according to any preceding claim, wherein the conical cutter comprises at least one cutting blade, the or each cutting blade having a cutting edge.
13. A device according to claim 12, including a conical body, the or each cutting blade being mounted in a recess in the conical body with the cutting edge protruding therefrom.
14. A device according to claim 12 or 13, wherein the or each cutting blade is removable.
15. A device according to any of claims 12 to 14, wherein the or each cutting blade is angled such that the cutting edge points in the direction of rotation of the device.
16. A device according to any of claims 12 to 15, comprising three cutting blades.
17. A device according to any of claims 12 to 16, wherein the or each cutting blade is helical.
18. A device according to any preceding claim, wherein the conical cutter is truncated.
19. A device according to claim 13, wherein the conical body is made from a nonmetallic material.
20. A device according to claim 19, wherein the conical body is made from plastics material.
21. A method of filling a hole in a sheet of material comprising the steps of: a) forming a tapered surface around said hole using a device according to any of the preceding claims; b) inserting a tapered plug into the hole such that it seats against the tapered edge, the plug being dimensioned so that its outside face lies at or below the level of the front face of the sheet of material; and c) plastering or rendering over the plug.
22. A method according to claim 21, wherein step (a) includes the step of making the hole circular whilst forming the tapered edge.
23. A method according to claim 21 or 22, wherein it includes the step of applying a coating of plaster to the edge of the hole and/or tapered plug before inserting the plug into the hole.
24. A plug for use in the method according to any of claims 21 to 23, comprising a conical body with a tapered curved edge insertable into a hole in a sheet of material so that its outside face lies below the level of the front face of the sheet of material.
25. A plug according to claim 24, wherein the conical body is truncated.
26. A plug according to claim 24 or 25 wherein the plug is formed out of plasterboard.
27. A plug according to claims 24 or 25 wherein the plug is made from a plastics material.
28. A plug according to claims 24 to 27 wherein the plug is solid.
29. A method substantially as hereinbefore described with reference to the accompanying drawings.
30. A device substantially as hereinbefore described with reference to the accompanying drawings.
31. A plug substantially as hereinbefore described with reference to the accompanying drawings.