GB2320212A - Improvements relating to cladding sheets - Google Patents

Abstract

A method and apparatus for producing a tapered cladding sheet (10) of a type in which the outer surface is provided with elongate ribs (12) and with a partial rib (14) formed at each side which in use interlinks with the side rib of an adjacent sheet. The sheet is clamped in the flat area between two adjacent elongate ribs (12) and a tapered rib (16) is formed therebetween by progressively engaging a forming tool (24) against the inside face thereof. The cladding sheet may be clamped between pairs of rollers (22) at each side of the forming tool.

Description

Title: Improvements Relating to Cladding Sheets Field of the Invention This invention relates to cladding sheets. and to a method of and apparatus for producing cladding sheets. More particularly the invention relates to roof cladding sheets of a type in which the outer surface is provided with elongate ribs and with a partial rib formed at each side which in use interlinks with the side rib of an adjacent sheet. Such sheets are hereinafter referred to as cladding sheets of the type described.

Backoround of the Invention Roof cladding sheets of the type described are used widely in the industrial construction industry, for example in warehouses and factories. However, since they are of a regular rectangular shape. their field of use is to some extent limited. For example, they cannot well be applied to a roof which is of a trapezium shape, since the edges of the sheets would then not be aligned with the sides of the roof.

It is an object of the present invention to provide a novel cladding sheet whose sides arc not parallel, and to a method and apparatus for producing such sheets.

Summarv of the Invention According to one aspect of the invention there is provided a method of producing a cladding sheet of the type described in which a partially formed cladding sheet is clamped in the flat area between two adjacent elongate ribs, and a tapered rib is formed therebetween by progrcssively engaging a forming tool against the inside face thereof.

Preferably the cladding sheet is clamped between pairs of rollers at each side of the forming tool, the rollers feeding the sheet longitudinally whilst the forming tool is progressively moved upward against the sheet.

According to a further aspect of the invention there is provided apparatus for producing a cladding sheet of the type described and with at least one outwardly directed tapering rib formed between two adjacent elongate ribs. comprising means for clamping the sheet between the adjacent ribs, a forming tool disposed between the clamping means for engagement with the underside of the sheet, cam means for raising the tool progressively against the sheet, and feed means for causing relative movement between the sheet and the tool.

Preferably the clamping means comprises opposed pairs of rollers which are driven and thereby constitute said feed means.

The cam means may be an eccentric cam.

Advantageously the cam is controlled by an encoder which is in direct contact with the sheet as the sheet passes the cam.

Preferably the rolling tool has an arcuate profile.

Brief Description of Embodiment The invention will now be described, by way of example only. with reference to the accompanying drawings in which: Figure 1 is a perspective view of a roof cladding sheet produced in accordance with the invention: Figure 2 is a cross-sectional view of apparatus for producing the tapered ribs on a cladding sheet as shown in Figure 1: Figure 3 is a side view of a forming tool as seen in section in Figure 2; and Figure 4 is an enlarged section of a forming tool showing the different profiles of the tool at successive stations of the rolling mill.

Detailed Description of Embodiment Referring first to Figure 1, there is shown a roof cladding sheet of trapezium shape 10, produced in accordance with the invention. The dimensions of the sheet are typically, but not exclusively. about 400mm wide at its narrow end, 508mm wide at its wide end, and between 10m and 20m in length. The central portion of the sheet is shown broken away, in order more clearly to show the two ends.

The cladding sheet 10 essentially comprises a central longitudinal rib 12, which is somewhat "keyhole" shaped in section, with a similar rib 14 at each side, but each with its outer leg shortened. The outer ribs 14 are so designed that a rib of one sheet can be clipped into engagement with a rib of an adjacent sheet to form a rainproof joint, so that any number of sheets can be linked together to form a roof covering. For a further description of the cladding sheets and the method of their inter-engagement for a roof structure, reference is made to UK Patent Specification No 2279089. Such sheets are known by the Registered Trade Mark "SpeedDeck", and are manufactured by the Applicants.

In the modified sheet shown in Figure 1 there is additionally formed between each outer rib and the central rib a tapering rib 16 of arcuate section, such that the outer ribs are typically drawn together approximately 100mum closer at one end than at the other end.

Figures 2 to 4 illustrate how the tapered ribs 16 of the sheet 10 are formed.

Figure 2 is a sectional view of one station of a rolling mill, which may typically comprise eight stations.

The central rib 12 is located by a driven guide roller 20. The tiat portion of the sheet at each side of the rib 12 is gripped by a pair of knurled feed wheels 22, which thus engage the upper and lower surfaces of the flat portion of the sheet.

Adjacent each wheel 22 is a forming tool roll 27l. of generally "doughnut" shape, and having an outer tooling surface. As shown in Figure 3, each roll 24 is freely mounted for rotation about a shaft 26 carried by a pair of pivotal arms 28, which in operation are raised by an eccentric cam (not shown) under mechanical/numerical control, Outside each roll 24 are a pair of feed wheels 30, which are similar to the feed wheels 22.

As previously stated, there are plurality of rolling stations, and the diameter of the tooling surface of the roll 24 at each station is progressively greater, as illustrated for example by the four tooling profiles 24A to 24D in Figure 4.

In use a sheet 10 is inserted from one end into the first station of the rolling mill, as above described. An encoder (not shown) connected to a computer control, is mounted in direct contact with the sheet, and is set to zero. If desired, the guide roller 20 may itself also act as the encoder.

As the pairs of feed wheels 22 and 30 drive the sheet 10 past the tool rolls, they are progressively raised by the eccentric cams (not shown) under the control of the encoder, thus starting to create the tapered ribs 16. At the end of its travel the sheet is passed into the next station where a pair of rolls 24 of greater diameter (e.g. having a profile 24B) act on the tapered ribs 16, thereby progressively increasing the depth of penetration into the ribs.

Due to the flow of sheet metal around the forming rolls. the sides of the cladding sheet 1() are moved inwards towards the narrow end of the sheet. To accommodate this inward movement. the outer feed wheels 30 must accommodate the slight transverse movement of the sheet relative to its direction of drive.

The apparatus and method of producing the tapered sheet as above described, are considered to be simpler than known ones. which require pre-cutting of the flat material into a trapezium shape, followed by multiple passes through a taper machine.

Claims (7)

1. A method of producing a cladding sheet of the type described in which a partially formed cladding sheet is clamped in the flat area between two adjacent elongate ribs, and a tapered rib is formed therebetween by progressively engaging a forming tool against the inside face thereof.

2. A method according to claim 1 in which the cladding sheet is clamped between pairs of rollers at each side of the forming tool, the rollers feeding the sheet longitudinally whilst the forming tool is progressively moved upward against the sheet.

3. Apparatus for producing a cladding sheet of the type described and with at least one outwardly directed tapering rib formed between two adjacent elongate ribs, comprising means for clamping the sheet between the adjacent ribs, a forming tool disposed between the clamping means for engagement with the underside of the sheet, cam means for raising the tool progressively against the sheet, and feed means for causing relative movement between the sheet and the tool.

4. Apparatus according to claim 3 in which the clamping means comprises opposed pairs of rollers which are driven and thereby constitute said feed means.

5. Apparatus according to claim 3 or claim 4 in which the cam means is an eccentric cam.

6. Apparatus according to any one of claims 3 to 5 in which the cam means is controlled by an encoder which is in direct contact with the sheet as the sheet passes the cam means.

7. Apparatus according to any one of claims 3 to 6 in which said forming tool

7. Apparatus according to any one of claims 3 to 6 in which said forming tool comprises a plurality of rolling tools having progressively greater arcuate profiles.

8. A method of producing a cladding sheet substantially as herein described with reference to, and as shown in, the accompanying drawings.

9. Apparatus for producing a cladding sheet substantially as herein described with reference to, and as shown in, the accompanying drawings.

Amendments to the claims have been filed as follows 1. A method of producing a cladding sheet of the type described in which a partially formed cladding sheet is clamped in the flat area between two adjacent elongate ribs, and a tapering rib is formed therebetween by progressively engaging a forming tool against the inside face thereof, the tapering rib being tapered at least in the plane of the sheet.

2. A method according to claim 1 in which the cladding sheet is clamped between pairs of rollers at each side of the forming tool. the rollers feeding the sheet longitudinally whilst the forming tool is progressively moved upward against the sheet.

3. Apparatus for producing a cladding sheet of the type described and with at least one outwardly directed tapering rib formed between two adjacent elongate ribs, the tapering rib being tapered at least in the plane of the sheet, comprising means for clamping the sheet between the adjacent ribs, a forming tool disposed between the clamping means for engagement with the underside of the sheet, cam means for raising the tool progressively against the sheet, and feed means for causing relative movement between the sheet and the tool.

4. Apparatus according to claim 3 in which the clamping means comprises opposed pairs of rollers which are driven and thereby constitute said feed means.

5. Apparatus according to claim 3 or claim 4 in which the cam means is an eccentric cam.

6. Apparatus according to any one of claims 3 to 5 in which the cam means is controlled by an encoder which is in direct contact with the sheet as the sheet passes the cam means.