AU720739B2

AU720739B2 - Cornices and mouldings

Info

Publication number: AU720739B2
Application number: AU76464/96A
Authority: AU
Inventors: Garry Reginald Johnstone
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-01-04
Filing date: 1996-12-24
Publication date: 2000-06-08
Anticipated expiration: 2016-12-24
Also published as: AU7646496A

Description

1 P/00/011 Regulation 3.2 COMMONWEALTH OF AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: GARRY REGINALD JOHNSTONE Actual Inventor(s): GARRY REGINALD JOHNSTONE Address for Service:

AHEARNS

Patent Trade Mark Attorneys, GPO Box 185, Brisbane, 4001 Invention Title: "CORNICES AND MOULDINGS" The following statement is a full description of this invention, including the best method of performing it known to me: -2- This invention relates to cornices and mouldings and has particular application with plasterboard walls particularly plasterboard of the type having a gypsum core faced on both sides by a layer of paper, for example plasterboard sold under the trade name "GYPROCK".

Cornices commonly used with plasterboard ceilings and walls and known as "coving" due to its annular segment shape has a gypsum core encased with paper. Such cornices can generally be easily fixed to the ceiling and walls with cornice cement but often two persons are required to position the cornice as desired to avoid breakage of the cornice because of its very low tensile strength. Furthermore, such cornices are very plain in appearance.

Other cornices of a more elaborate and fanciful appearance are available but these are constructed of fibrous plaster and are thus much more expensive to produce. Furthermore, such fibrous plaster cornices require a reasonable amount of skill a.e for fixing in place particularly in the corners of rooms where joining of non aligned pieces is necessary.

a...o oooo* One attempt at overcoming some of the aforementioned problems has provided a cornice having a polystyrene foam core encased in a layer of paper. However, in order to provide a cornice having sufficient strength and of satisfactory appearance, it has been necessary to utilise a high quality polystyrene foam, particularly in cases where sharp or crisp looking edges are required. Furthernmore, the layer of paper has a tendency to peel or delaminate from the polystyrene core particularly when more elaborate designs are provided.

The present invention aims to alleviate at least one of .4 -3the aforementioned disadvantages and to provide cornices or mouldings which will be reliable and efficient in use.

With the foregoing in view this invention in one aspect resides broadly in a cornice or moulding having a core constructed of a relatively lightweight material and a layer of metal secured to said core and covering only that part of the core which would otherwise be exposed to view when in use, and wherein said core has one or more planar surfaces adapted to abut a wall and/or ceiling to which the cornice or moulding is to be affixed.

Preferably the layer of metal is sheet metal and preferably zincalume based. Advantageously, the sheet metal can be folded or rolled to provide sharply defined edges to provide an attractive appearance or even embossed if desired. In a preferred form the zincalume is pre-painted, for example, colourbond steel by Lysart. It is also preferred that the core be constructed of a low-grade polystyrene foam having a oo thickness large enough to provide a cornice of sufficient Ce rigidity for securing to the walls and ceiling.

Preferably, the core is secured to the layer of metal by

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C adhesive and it will be appreciated that partial delamination of the metal from the core is not greatly detrimental to the cornice or moulding and has no undesirable visible effect as is the case with plaster cornices.

Preferably the core is shaped to provide a planar surface adapted to abut a wall to which the cornice or moulding is to be affixed. In the case of a cornice it is preferred that the core be provided with two orthogonal planar surfaces for affixing to the ceiling and the wall. It is also preferred that the cornice or moulding have a layer of paper (of the type R/commonly referred to as plasterboard paper and used in the ufacture of Gyprock) adhered to the planar surface or 4 -4surfaces whereby the cornice or moulding can be easily secured to a plasterboard wall and/or ceiling with the use of plaster cement as is presently possible with known plasterboard cornices.

In another aspect this invention resides broadly in a method of constructing a cornice or moulding including: providing a length of sheet metal; providing a length of core material such as polystyrene foam; forming said sheet metal to a desired profile covering only that part of the core which would otherwise be exposed to view when in use; forming said core material to have at least one planar surface adapted for abutting a wall or ceiling panel and to have a complementary profile whereby said core material may be juxtaposed with said length of sheet metal, and "securing said core material to said length of sheet metal in juxtaposed relation with a suitable adhesive.

S• In a preferred form the method includes forming two orthogonal planar surfaces for abutting a wall and adjacent ceiling. It is also preferred that the method includes adhering a layer of paper to the or each planar surface.

In order that this invention may be readily understood and 9.

put into practical effect reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and where: 0e~ S Fig. 1 is a pictorial representation of a prior art cornice; Fig. 2 is a sectional end elevation of another prior art cornice in position for fixing to a wall and adjacent ceiling; Fig. 3 is a sectional end elevation of a cornice according to the present invention; and Fig. 4 is a sectional end elevation of a moulding constructed according to the present invention.

The prior art cornice 10 illustrated in Fig. 1 has a core 11 formed of gypsum and a covering layer 12 formed of plaster paper which is adhered to the two curved surfaces 13 and 14 and the two edge surfaces 16 and 17.

Another prior art cornice 20 is illustrated in Fig. 2 in position secured to a plasterboard wall and ceiling 21 and 22 respectively along edge faces 23 and 24. The cornice 20 is constructed of relatively high grade polystyrene foam and is encased on a very thin layer of resin (not shown).

The cornice 30 constructed according to the present vow• invention and illustrated in Fig. 3 has a core 31 formed of relatively low grade polystyrene foam and has a rear face 32 and a front face 33 taking a stepped form and two edge faces 34 and 36. The cornice is intended for use in a manner similar to that illustrated in Fig. 2. A thin layer of zincalume 37 .prepainted by the colourbond process is secured to the front face by a layer of adhesive 38, the layer of zincalume have been previously folded to form the stepped cross section illustrated and the core 31 also being cut to the profile complementary to the cross sectional form of the zincalume prior to adhering together. A layer of plaster paper 41 is secured to each of the edges 34 and 36 by a layer of appropriate adhesive 42. Advantageously, the plaster paper 41 allows the cornice to be secured to the plasterboard wall and ceiling with the use of cornice cement as it presently used with the cornice of Fig. i. A corner piece designed to complement the profile of the cornice 30 may be provided so that mitred joints are not required in room corners. Such corner piece may be formed of pressed metal and adapted to overlap the end portions of the cornices.

The moulding 50 illustrated in Fig. 4 is similar to the cornice of Fig. 3 and has a low grade polystyrene foam core 51 having a rear face 52 and a front face 53 and a bottom edge face 54. A layer of zincalume 55 is secured to the front face and the bottom edge face in a manner similar to that described in relation to Fig. 3 by a layer of adhesive 56. A layer of plaster paper 41 is secured to the back face 52 in the same manner as described in relation to Fig. 3. Whilst the moulding of this embodiment is simple in profile, mouldings of many m ul i gs o m n different and complex profiles can be manufactured according to the present invention. For example, the present invention could provide a particularly advantageous picture rail in which the upper surface is formed of zincalume allowing for easy cleaning.

It will be appreciated that the zincalume facing provides ao. ~an attractive appearance having neat crisp edges and the core provides sufficient rigidity to the zincalume layer without increasing its weight significantly. Furthermore, a large number of patterns can be provided by embossing or folding the sheet metal and in some cases it is not necessary to adhere the core to the complete surface of the sheet metal layer. For example, the polystyrene foam may be apertured to surround embossed areas. This is particularly advantageous for the manufacture of ceiling plaques.

It will of course be realised that while the foregoing description has been given by way of illustrative example of -7this invention all such and other modifications and variations thereto us would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as defined in the appended claims.

.iie *o o *o**o o

Claims

1. A cornice or moulding having a core constructed of a relatively lightweight material and a layer of metal secured-to said core and covering only that part of the core which would otherwise be exposed to view when in use, and wherein said core has one or more planar surfaces adapted to abut a wall and/or ceiling to which the cornice or moulding is to be affixed.

2. A cornice or moulding according to Claim i, wherein said metal is roll formed to a desired profile.

3. A cornice or moulding according to Claim 1 or Claim 2, wherein said core is constructed of a low-grade polystyrene foam. S 4. A cornice or moulding according to any one of the preceding claims, wherein said core is secured to said layer of metal by adhesive. ee

9. A cornice according to any one of the preceding claims, wherein said core has two orthogonal surfaces for affixing to the ceiling and the wall respectively. ooo A cornice or moulding according to any one of the preceding claims, wherein said core is polystyrene foam and has a layer of paper adhered to the planar surface or surfaces. 7. A method of constructing a cornice or moulding including: providing a length of sheet metal; -9- foam; forming said sheet metal to a desired profile covering only that part of the core which would otherwise be exposed to view when in use; forming said core material to have at least one planar surface adapted for abutting a wall or ceiling panel and to have a complementary profile whereby said core material may be juxtaposed with said length of sheet metal, and securing said core material to said length of sheet metal in juxtaposed relation with a suitable adhesive. 8. A method of constructing a cornice or moulding according to claim 7, including adhering a layer of paper to one or more of said at least one planar surfaces. DATED this 1 0 t h day of April, 2000 GARRY REGINALD JOHNSTONE By his Patent Attorneys AHEARNS oo *o