AU642794B2

AU642794B2 - Metal plank

Info

Publication number: AU642794B2
Application number: AU90013/91A
Authority: AU
Inventors: Campbell John Seccombe
Original assignee: John Lysaght Australia Pty Ltd
Current assignee: John Lysaght Australia Pty Ltd
Priority date: 1991-01-02
Filing date: 1991-12-23
Publication date: 1993-10-28
Anticipated expiration: 2011-12-23
Also published as: AU9001391A

Description

I -4 ~i~l 642794 P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: METAL PLANK C X t The following statement is a full description of this invention, including the best method of performing it known to the Applicant: This invention relates to metal planks, that is to say light metal beams usually comprising an elongated panel with downwardly directed side flanges providing strength and rigidity. Typically, such metal planks are used as walkways on scaffolding, as working platforms extending t C E t Cbetween trestles, as temporary walkways across muddy ground, and in many other ways at building sites and the like.

Metal planks are lighter and stronger than the more traditional timber planks, but they have one disadvantage, namely they are more slippery to walk on unless the main or upper surface of the plank is patterned in a manner to provide some surface roughness.

SMany and various surface patterns have been proposed hitherto, but none has been fully satisfactory. A delicate balance has to be struck between roughness and smoothness of pattern. If the pattern is 2 too smooth the plank may be dangerously slippery, especially for a person wearing thick and hard-soled work boots. If too rough the pattern may prove to be uncomfortable, especially for a person wishing to kneel on the plank while wearing work shorts.

Many otherwise satisfactory patterns require to be oress-formed in the surface of the plank, calling for the use of large and expensive dies. Even when the pattern is roll-formed into a sheet before fabrication of the plank, it has usually been necessary to use mating indented and embossed rolls which are also expensive and of limited life.

0Therefore, an object of tih-e invention is to provide a metal plank *99000 having a roll-formed pattern such that the rolls do not have to be matching (that is to say the indented pattern on one roll does not have *s.0 C to be otherwise the same as the embossed pattern on the other roll), and which achieves a desirable balance between roughness and smoothness as aforesaid.

The invention achieves that object by providing a plank having a surface pattern comprising rows of mounds projecting upwardly from a base surface, being the upper surface of the plank, wherein each mound when viewed from above is generally rectangular or square in outline and wherein the ends of the mounds extending transversely of the plank merge smoothly into the base surface from which the mounds rise, and the edges of the mounds extending longitudinally of the plank are each sharply defined by an edge face of the mound substantially perpendicular to the base surface.

f- 3 Therefore the invention consists in a metal plank having a surface pattern as described above.

The invention also consists in a method of making such a plank comprising the steps of passing a metal strip between the nip of two pressure rolls, one of which has a plurality of circumferential rows of protuberant die bosses on its curved surface conforming to the underneath surface of the mounds in the plank, and the other of which has a like plurality of circumferential grooves in its curved surface in respective register with the rows of bosses on said one roll and having flat side faces lying in planes normal to the roll axis between which said bosses are a neat fit, to produce a patterned strip, and subsequently forming the patterned strip into a plank.

4 4 By way of example, an embodiment of the above described 4' 4invention is described in more detail hereinafter with reference to the accompanying drawings.

Figure 1 is a perspective view of an end part of a plank according 2P. to the invention.

Ii E oFigure 2 is an enlarged detail of a mound indicated at 2 in figure 1.

Figure 3 is an end view of the body of the plank of figure 3 drawn to a slightly larger scale.

The illustrated plank is formed in conventional manner, that is to say cut and folded or roll formed from a strip of ;netal, for example, coated steel, sheet, to provide an upper elongate panel 4 with i 4 downwardly directed side flanges 5. Those flanges 5 preferably have inwardly directed lip flarnges 6 extending therealong to provide sufficient bearing surface when the plank is laid upon a support. Moreover, the lip flanges 6 may have edge flanges 7 to provide anchorages for hooks on the ends of tie ropes or straps, as may be used to secure the plank to scaffolding or the like.

In accordance with the invention, that portion of the strip which eventually constitutes the main, upper panel 4 has a roll-formed pattern impressed in it comprising rows of mounds 8 as described above.

In the present instance there are two bands of pattern, each of 0 three rows of mounds, extending longitudinally of the plank.

Alternatively the rows may be substantially uniformly spaced over the entire surface of the panel. In any event it is preferred that the mounds in closely spaced neighbouring rows be staggered in the longitudinal direction of the plank, as is the case for the rows in each band of the illustrated plank.

When viewed in plan each mound 8 may be about 8 mm. long and 6 mm. wide. They may be spaced, centre to centre, in the row by *about 45 mm. and the rows in each band may be spaced laterally, centre to centre, by, say, 25 mm.

As may best be seen in figure 2 the individual mounds 8 preferably present a smoothly arched profile iin longitudinal section, with a crest elevated above the base surface by a distance equal to about half the thickness of the metal sheet from which the plank is made, that is to say an elevation of about 1 mm. in the case of a sheet 2 mm. thick.

This enables the pattern to be rolled into the sheet by a pair of rolls, of I 7i~7-- I- ~r which the female roll is a plain cylindrical roll but for rectangular sectioned, circumferential grooves in its curved surface, corresponding in width to the width of the required mounds and in position to the row positions of the finished plank, and the male die has circumferential rows of protuberant die bosses, likewise conforming to the row positions, to the spacing between mounds in the row direction and to the shape of the impression in the under side of the panel 4 needed to produce the required mound shape in its upper surface.

The die bosses of the male roll are a neat fit between the radially extending side walls of the grooves in the female roll. Thus the finished mounds in the plank have flat longitudinal edge faces 9 produced by the shearing action between the side faces of the die bosses and the side walls of the grooves, and ends 10 showing a smooth transition with the 1'6 base surface of the panel as there is no counter, female die surface opposing the circumferentially spaced edges of the male die bosses.

Each end of the finished plank is preferably finished off with a cap presenting substantially a continuation of the side flanges 5 filling the end of the plank. In the present instance each cap is a moulded plastics cap 11 having a skirt fitting neatly within the end of the body of the plank and clinched in place by deformations formed in the edge flanges 7.

t

Claims

1. A metal plank having a surface pattern comprising rows of mounds projecting upwardly from a base surface, being the upper surface of the plank, wherein each mound when viewed from above is generally rectangular or square in outline and wherein the ends of the mounds extending transversely of the plank merge smoothly into the base surface, and the edges of the mounds extending longitudinally of 4the plank are each sharply defined by an edge face of the mound substantially perpendicular to the base surface.

2. A plank according to claim 1 wherein said pattern comprises S° spaced apart bands of said rows of mounds.

3. A plank according to either claim 1 or claim 2 comprising an elongate panel in which said pattern is formed and side flanges I extending along the longitudinal edges of said panel and projecting downwardly from said panel.

4. A plank according to claim 3 further comprising lip flanges extending along the free edges of said side flanges and projecting horizontally towards each other.

A plank according to claim 4 further comprising edge flanges extending along the free edges of said lip flanges and projecting U upwardly towards said panel,

6. A plank according to any one of claims 3 to 5 furnished with i end caps. Z~ srr-- I~ 7

7. A metal plank substantially as described herein with reference to the accompanying drawings.

8. A method of making a plank according to any one of the preceding claims comprising the steps of passing a metal strip between the nip of two pressure rolls, one of which has a plurality of circumferential rows of protuberant die bosses on its curved surface conforming to the underneath surface of the mounds in the plank and the other of which has a like plurality of circumferential grooves in its curved surface in respective register with the rows of bosses on said one roll and having flat side faces lying in planes normal to the roll axis between which said bosses are a neat fit, to produce a patterned strip, and subsequently forming the patterned strip into said plank. Applicant JOHN LYSAGHT (AUSTRALIA) LIMITED Date 23 December 1991 Attorney ROBERT G. SHELSTON F.I.P.A.A. Sof CARTER SMITH BEADLE C c y L i ABSTRACT A metal plank comprises a main body panel having a surface pattern comprising rows of mounds projecting upwardly from the upper surface of the panel wherein each mound when viewed from above is generally rectangular in outline and wherein the ends of the mounds extending transversely of the plank merge smoothly into the panel surface, and the edges of the mounds extending longitudinally of the plank are each sharply defined by an edge face (9) of the mound substantially perpendicular to the panel surface, downwardly projecting side flanges extending along the longitudinal edges of the panel horizontally inwardly projecting lip flanges (6) extending along the free edges of the side flanges upwardly projecting edge flanges extending along the free edges of the lip flanges and moulded plastics end caps (11) filling the ends of the plank. Figure 1. ii 2 I I< t