AU666879B2 - Improvements in plasterboard - Google Patents

Description

666879

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AUSTRALIA

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Name of Applicant Actual Inventor Address for Service WILLIAM CLIFFORD TUCKER S WILLIAM CLIFFORD TUCKER GRANT ADAMS COMPANY, Patent Trade Mark Attorneys Level 9, National Mutual Centre, 144 Edward Street, BRISBANE. QLD. 4000

AUSTRALIA.

"IMPROVEMENTS IN PLASTERBOARD" Invention Title Details of Associated Provisional Applications Numbers PK9300 The following statement is a full description of the invention including the best method of performing it known to me.

THIS INVENTION relates to improvements in plasterboard.

Plasterboard installers encounter difficulty in forming a neat corner at the junction of two sheets, especially on the "exterior" of the corner.

It is an object of the present invention to provide an improved method for forming a corner between two plasterboard sections.

It is a preferred object to provide a method where the external corner may be rounded or curved, eg. have a "bullnose" profile.

It is a further preferred object that the :.".liner be continuous about the exterior of the corner.

ee 15 Other preferred objects will become apparent from the following description.

eee In one aspect, the present invention resides in a method of forming a corner in a length of plasterboard (of the type having a core of plaster sandwiched between a pair of face liners), the method including the steps of: cutting a groove through one liner and e the plaster core to, or adjacent, an inner face of the second liner to define two side sections of the 25 plasterboard interconnected by the second liner, each side section having a side edge inclined or perpendicular to the second liner; placing an infill member, having a desired external profile, between the adjacent side edges; moving the two side sections relative to each other to bring the side edges into contact with the infill member and then form the second liner about the external profile of the infill member; and taping and setting the internal corner formed at the junction of the two side sections, or at the respective junction of each side section and P Y the infill member.

The infill is preferably of quarter-round section, with an outer curvature of desired radius for the external corner. If preferred, the external profile may have a plurality of adjacent, planar surfaces or the like.

To enable the invention to be fully understood, a number of preferred embodiments will now be described, with reference to the accompanying drawings, in which: Figs 1 and 2 show the steps of forming a "bullnose" corner; and Figs 3 to 5 show the steps for large radius corners.

Referring to FIGS 1 and 2, for a "bullnose" 15 corner, router 110 forms a groove 111 with parallel side edges 112, 113 in the inner liner 114 and plaster core 115, the outer liner 116 being exposed, but not cut, to form plasterboard sections AA, BB.

An infill member 118, of quarter-round section (and of the same thickness as the plaster 0 core 118) is located with one side face 119 butted against the side edge 112 of section AA. Section BB is swung around until its side edge 113 abuts side edge 120 of the infill member 118, while the outer 25 liner 116 follows the curved profile 121 of the third side of the infill member providing an external corner formed of a smooth, continuous connection between the two sections AA, BB, with high aesthetic appeal which may avoid the need to plaster the external corner. Tape 117 is applied to the iternal "orner and the corner is plastered.

The radius of the curved profile 121 can be varied to provide a wide range of curvatures for the external corner and it can be substituted alternative profiles, eg. curve/flat/curve or flat/flat/flat. As the radius of curvature of the profile 121 is increased, the distance between the if side edges 112, 113 must be increased to accommodate the greater length of outer liner 116 which must be wrapped around the curved profile.

Referring now to Figs 3 to 5, for large radius corners, a much wider groove 211 is cut in the inner liner 214 and plaster core 215. It will be noted that a thin layer 215A of the core 215 may be left along the outer liner 216.

The infill member 218 is placed between the side sections AAA, BBB with its side edges 219, 220 (which may be perpendicular (see FIG 4) or angularly inclined (see FIG 5) in engagement with the side edges 212, 213 of the side sections AAA, BBB. A respective strip of tape 217, 217A is used to set the respective junctions of the infill member 218 with the side sections AAA, BBB.

By selecting the radius of curvature of the external profile 221 of the infill member 218, and the included angle a (ie. 00< a <180°) of the side edges 219, 220, a wide range of corners can be formed.

6 6i 6 6* 6 6 666 690 *a 6 6 69 9 It will be readily apparent to the skilled addressee that the present invention provides simple methods for the forming of neat corners at the junctions of two sections of plasterboard.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the present invention defined in the appended claims.

Claims (9)

1. A method of forming a corner in a length of plasterboard (of the type having a core of plaster sandwiched between a pair of face liners) including the steps of: cutting a groove through one liner and the plaster core to, or adjacent, an inner face of the second liner to define two side sections of the plasterboard interconnected by the second liner, each side section having a side edge inclined or perpendicular to the second liner; placing an infill member, having a desired external profile, between the adjacent side edges; :15 moving the two side sections relative to each other to bring the side edges into contact with the infill member and then form the second liner S: about the external profile of the infill member; and S. S" taping and setting the internal corner formed at the junction of the two side sections, or at the respective junction of each side section and the infill member.

2. A method as claimed in Claim 1 wherein: the groove is formed by a complementary 25 profiled router.

3. A method according to Claim 1 wherein: the infill member is of a thickness substantially equal to the thickness of the plaster core.

4. A method according to Claim 1 or Claim 3 wherein: the infill member has side edges interconnected by an apex, and the included angle between the side edges at hne apex is less than 180°.

5. A method according to Claim 4 wherein: the included angle is 600, 90° or 120°.

6. A method according to any one of Claims 1 and 3 to 5 wherein: the external profile of the infill member is a continuous curve of desired radius for the external corner, or has a plurality of planar faces inclined to each other.

7. A length of plasterboard having at least one corner formed by the method of any one of Claims 1 to 6.

8. A method of forming a corner in a length of plasterboard substantially as hereinbefore described with reference to FIGS 1 and 2; or FIGS 3 to 5 of the accompanying drawings.

9. A length of plasterboard having at least 15 one corner formed by the method of Claim 8. DATED this nineteenth day of December 1995. WILLIAM CLIFFORD TUCKER, By his Patent Attorneys, GRANT ADAMS COMPANY. e o S. ABSTRACT To form a corner in a sheet of plasterboard, a groove (211) is cut through one liner (214) and the plaster core (215) to, or adjacent, the second liner (216); an infill member (218) is placed between the side sections (AAA, BBB) of the plasterboard, the side sections being swung to the desired position, and the junctions between the side sections (AAA, BBB) and the infill member (218) are taped and set. The second liner (216) of the plasterboard is continuous about the corner, its shape being determined by the external profile (221) of the infill member (218). R C Re C CC C.*