AU761536B2

AU761536B2 - Method of, and apparatus for, the manufacture of cornices

Info

Publication number: AU761536B2
Application number: AU35053/99A
Authority: AU
Inventors: William Clifford Tucker
Original assignee: PROFILES IN PLASTER Pty Ltd
Current assignee: PROFILES IN PLASTER Pty Ltd
Priority date: 1998-04-29
Filing date: 1999-06-15
Publication date: 2003-06-05
Anticipated expiration: 2019-04-29
Also published as: AU3505399A

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 *c 4 0 0

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT *0 Invention Title: "METHOD OF, AND APPARATUS FOR, THE MANUFACTURE OF CORNICES" The following statement is a full description of this invention, including the best method of performing it known to me: THIS INVENTION relates to a method of, and apparatus for, the manufacture of cornices.

The invention is particularly suitable for, but not limited to, the manufacture of paper-faced plaster cornices.

Cornices are installed to conceal the junctions between the wall panels and ceiling panels in building constructions; and may be provided with relatively plain or "fancy" profiles. Conventionally, such cornices have been produced by machining lengths of timber to the prescribed profile.

10 With the increasing cost of timber and the associated costs in machining it to shape, attention has turned to alternative methods for manufacturing cornices and one method which has been adopted has been paper-faced plaster cornices where a paper-faced layer overlies a plaster-based core. One advantage of such a method 15 of cornice manufacture is that the plaster-based core gives a fireresistance at the wall and ceiling junction which can limit the rate at which a fire can escape through the junction to an adjacent room.

To date, the manufacture of paper-faced plaster cornices has been relatively labour-intensive; and thereby relatively expensive and difficult to accurately control quality standards.

It is an object of the present invention to provide a method of manufacture of paper-faced plaster cornices which can operate on a "production line" type system.

3 It is a preferred object of the present invention to provide an apparatus suitable for the method.

It is a still further preferred object to provide an apparatus where the cornices can be manufactured quickly, efficiently and relatively inexpensively in a range of lengths.

It is a still further preferred object of the present invention to provide a method where a number of alternative profiles can be provided to the cornices.

Other preferred objects of the present invention will 10 become apparent from the following description.

In one aspect, the present invention resides in a method of manufacturing a paper-faced plaster cornice including the steps of: a) drawing a paper-facing strip from a source; b) drawing the paper strip through a cutting head S 15 having a plurality of cutting wheels to cut respective grooves or fold •..•lines in the back of the paper or strip, so that the paper strip will fold in straight lines with little tension; c) drawing the paper strip through a shaping head to form the paper strip to the face profile desired, the shaping head having a moulded tapered section which is initially flat and progressively formed to the face shape at the other end; d) applying plaster to the rear face of the strip; e) passing the paper strip/plaster assembly through a 4 die and along a mould to form the final overall shape of the cornice; and f) allowing the plaster to set.

Preferably, in step a plurality of cutting wheels in the cutter head cut respective grooves in the back of the paper strip so that it will fold in straight lines with little tension.

Preferably, in step during a subsidiary step a wetting sponge applies a light film of water and additives to the prewet back of the paper to reduce the tension in the paper and make it 10 easier to shape. Preferably, the paper strip is passed through a final shaper, in a step (c2) after the wetting step the paper strip being .oo:o formed to the shape desired.

Preferably, in step the plaster is pumped in at a regulated speed via a mono pump (or other suitable pump).

Preferably, an accelerating liquid is added to the plaster o~~ just prior to filling, being mixed in a mixing head.

.000 Preferably, a skimmer box is provided in place to adjust a :0for any slight overfill.

Preferably, after step there is a step (da) where the assembly passes a flap turner which holds the outside steps in the right position as the back flaps of the paper strip are turned over.

Preferably, step (da) is followed by a step (db) where, in a gluing section where glue is applied to one side of the flaps before the flaps are engaged with the sides of the plaster core in step Preferably, the mould in step is coated with a non-slip material PTFE) sold under the trade mark "TEFLON".

In one embodiment, the cornice is pulled along the moulds using an endless cable system, where the cornice paper is held via a clamp and the clamp is hooked onto a cable which runs around spaced pulleys, one of which is pulled via a variable speed winch.

In an alternative embodiment, where the wave cornice or S: any cornice with an area wide enough to carry the cornice, a **10 continuous belt system is used. The belt is preferably a non-slip coated fibreglass belt pulled along a mould and this pulls and carries the finished cornice, the belt being pulled via a variable speed motor and rollers.

"oo ~In a second aspect, the present invention resides in an apparatus for carrying out the method hereinbefore described.

S"To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which: FIG. 1 is a schematic side view of a first embodiment of the apparatus; FIGS. 2 to 9 are sectional views taken on lines A-A to H- H inclusive on FIG. 1; and FIG. 10 is a perspective view of an endless cable drive.

Referring to FIG. 1, the facing strip 10 is drawn from a supply roll 11 and is drawn through a cutting head 20 shown in more detail in FIG. 2.

The cutting head has a drum 21 on a shaft 22 rotatably journalled in a cutting head frame 23. The shaft 22 is driven by an electric motor 24 via a belt-and-pulley drive assembly A plurality of radial cutting knives 26 are provided about S" the drum to cut grooves in the back face of the paper face strip 10 so that the strip will fold in straight lines with little tension. Knives 26 10 may co-operate with a "resilient" anvil 27. A shroud 28 is connected to a vacuum source (not shown) by a hose 29 to enable the material cut from the rear face of the strip 10 to be drawn away to a waste collection point.

The strip 10 is drawn through a shaping head 30 (see FIG. 3) which is tapered in plan view (with sides that are S"progressively increased in angle from the horizontal to the vertical) and with ridges and valleys of progressively increasing depth.

Intermediate the shaping head 30, a wetting sponge 40 applies a light film of water and additives to pre-wet the paper strip 10, reducing the tension in the paper strip and making it easier to shape. The mixture 41 of water/ additives is contained in a supply tank or container 42 into which the sponge 40 may extend.

As shown in FIG. 4, the now wet paper strip 10 is drawn through the final shaping portion 38 of the shaping head 30 so that the paper is formed to the shape required.

Plaster is applied from a source (not shown) and pumped at a regulated speed or volume via a monopump. Accelerating liquid is added to the plaster in a mixing head 51 of a plaster applicator as shown in FIG. 6 and skimmer boxes 60 shape the plaster core to the desired profile (see FIG. A flap turner 80 folds the outside steps in the right position as the outer flaps of the paper strip 10 are °turned over. At a gluing head 90, glue 91 from a source container 92, is applied to the flaps of the paper strip 10 via a gluing wheel 93 so that the paper strip 10 encloses the plaster core 70. The cornice assembly C is then pulled through a die assembly 100 (see FIG. 9) where opposed die pieces 101, 102 form the final overall shape of the cornice. The cornice assembly C is then pulled along a Teflon- 15 coated mould 110 by a drive assembly 120 (to be hereinafter described with reference to FIG. 10 until the cornice has been manufactured to the desired length).

The drive assembly 120 has an endless drive cable 121 which passes around a driven head pulley 122 and a freely rotating tail pulley (not shown). The head pulley 122 is driven by an electric motor 123 via a reduction gearing belt-and-pulley drive assembly 124.

The electric motor 123 has a variable speed control to enable the rate at which the cornice assembly is advanced along the mould 110.

8 A clamp 125 is placed on the forward end of the assembly C and is releasably secured to the cable 121 by a catch plate 126 to enable the cable 121 to pull the assembly C along the mould 110.

In an alternative embodiment (not shown), the clamp is attached to the forward end of the paper strip extending from the cornice assembly C. The paper is clamped every 2-3/4.2 metre lengths of cornice and cut off and pulled away. The paper is left ::empty for approximately 1 metre where the clamp has to go.

10 In a further alternative embodiment not shown, a wave cornice or any cornice with an area wide enough to carry the cornice, a continuous belt system is used. The belt is Teflon-coated fibreglass pulled along a mould and this pulls and carries the finished cornice.

The belt is pulled via a variable speed motor and rollers. The belt 15 does not have to be shaped to the shape of the mould, but the mould S9 should be Teflon-coated for less friction.

Preferably, the cable and belt sections of the mould are approximately 20 metres long, plus another 20 metres for setting and cutting. The length is dependent on the space available for the machine.

It will be readily apparent to the skilled addressee that the method and apparatus of the present invention enables paperfaced plaster cornices to be efficiently manufactured while maintaining high quality standards.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.

g

Claims

1. A method of manufacturing a paper-faced plaster cornice including the steps of: a) drawing a paper-facing strip from a source; b) drawing the paper strip through a cutting head having a plurality of cutting wheels to cut respective grooves or fold lines in the back of the paper strip, so that the paper strip will fold in straight lines with little tension; c) drawing the paper strip through a shaping head to 10 form the paper strip to the face profile desired, the shaping head having a moulded tapered section which is initially flat and :°°°°progressively formed to the face shape at the other end; d) applying plaster to the rear face of the strip; e) passing the paper strip/plaster assembly through a die and along a mould to form the final overall shape of the cornice; and 00•0f) allowing the plaster to set.

2. A method according to Claim 1 wherein: in step during a subsidiary step a wetting sponge applies a light film of water and additives to the pre-wet back of the paper to reduce the tension in the paper and make it easier to shape.

3. A method according to Claim 2 wherein: the paper strip is passed through a final shaper, in a step 11 (c2) after the wetting step the paper strip being formed to the shape desired.

4. A method according to any one of Claims 1 to 3, wherein: via a mono in step the plaster is pumped in at a regulated speed pump (or other suitable pump). A method according to any one of Claims 1 to 4 wherein: an accelerating liquid is added to the plaster just prior to j mixed in a mixing head.

A method according to Claim 6 wherein: a skimmer box is provided in place to adjust for any slight filling, bein

6. overfill.

7. A method according to any one of Claims 1 to 6 wherein: after step there is a step (da) where the assembly passes a flap turner which holds the outside steps in the right position as the back flaps of the paper strip are turned over.

8. A method according to Claim 7 wherein: preferably step (da) is followed by a step (db) where, in a gluing section where glue is applied to one side of the flaps before the flaps are engaged with the sides of the plaster core in step

9. A method according to Claim 8 wherein: the mould in step is coated with a non-slip material.

A method according to any one of Claims 1 to 9 wherein: the cornice is pulled along the moulds using an endless 12 cable system, where the cornice paper is held via a clamp and the clamp is hooked onto a cable which runs around spaced pulleys, one of which is pulled via a variable speed winch.

11. A method according to any one of Claims 1 to 5 wherein: the wave cornice or any cornice with an area wide enough to carry the cornice, a continuous belt system is used, the belt being a non-slip coated fibreglass belt puled along a mould and this pulls and carries the finished cornice, the belt being pulled via a variable speed motor and rollers. DATED this twenty-fourth day of March 2003. 0S 5* S PROFILES IN PLASTER PTY LTD By its Patent Attorneys FISHER ADAMS KELLY o Jees o •S o ,•o