AU2008221565A1

AU2008221565A1 - Grate

Info

Publication number: AU2008221565A1
Application number: AU2008221565A
Authority: AU
Inventors: Mark Schmacker; Paul Schmacker
Original assignee: SCHMACKER INVEST Pty Ltd
Current assignee: SCHMACKER INVESTMENTS Pty Ltd
Priority date: 2007-09-20
Filing date: 2008-09-19
Publication date: 2009-04-09

Description

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P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title:

"GRATE"

The following statement is a full description of this invention, including the best method of performing it known to me/us: 00 1 N TITLE 0 "GRATE" _FIELD OF THE INVENTION The present invention relates to grates, particularly but not exclusively those of metal, for use in applications such as in the architectural, drainage, mining and separating industries. The invention predominantly relates to a metal grate and a method of its production.

0BACKGROUND OF THE INVENTION While metal grates are used widely, some difficulties arise in their construction. The present standard practice in industry is to cut internal screens to size inside edge bars, abut the edge bars adjacent to the screen and weld the screen support rods or bars to the edges at the underside of the screen. This commonly involves the use of fillet welding on the abutting rods and edges of the inverted gratings. This is time consuming and costly.

It is difficult to provide a consistent weld strength. Further, splatter from the welding process lodges on the screen or edge bars necessitating its removal in the cleaning process. It is often very important to provide a high quality finish, particularly in expensive grates for use in architect designed environments. This further increases the time consumed in forming the grate. The present system also potentially creates a hygiene problem where the grate is to be used in a contaminated environment such as a urinal. It is almost impossible to removal all the particles of weld detritis. They may therefore act as a trap for biological material which may form a substrate for biological growth producing high numbers of bacteria, often associated with unpleasant odors.

A further problem may arise in that the strength of individual welds may vary between support rods with a potential for a weakness to develop. The response of professionals forming the grates is usually to over engineer the weld to ensure such a potential weakness does not arise. This in turn mandates the use of thicker edge bars to accept the weld which also increases costs and may distort the aesthetics of the grate particularly when 00 2

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used in architectural applications or interior design environments. An additional problem may arise if heat from welding distorts sections of the screen.

SUMMARY OF THE INVENTION In a first broad aspect, the invention may reside in a grate Ipreferably metal comprising: a screen, the screen formed by an array of longitudinal wires, N the array having a first edge wire and a second edge wire and a plurality of 00 Ssupport bars transverse to and fixed to the array, and support bar extension sections, each formed by a support bar extending beyond one of the edge wires; and one or more edge bars, each edge bar having two or more transverse holes extending across the edge bar; wherein: the support bar extension sections are entered into corresponding transverse holes and fixed in position.

Preferably, the grate is formed from stainless steel. The array of longitudinal wires may be formed from wedge wire. The first edge wire and/or second edge wire may abut an adjacent edge bar. Each support bar preferably has support bar extension sections positioned at each end.

The support bar extension sections may be fixed in position by welding, riveting, an interference fit, an adhesive or other suitable means known to a person skilled in the art.

The grate may include one or more end bars, with one or more holes extending across each end bar and adapted to receive the support bar extension sections when the end bar is inclined away from perpendicular to a long axis of the longitudinal wires.

In a further aspect, the invention may reside in a method of forming a grate, preferably metal, the method comprising the steps of: a) forming a screen having support bars with one or more support bar extension sections; 00 3

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Sb) forming two or more transverse holes in at least two spaced edge bars, each transverse hole extending across the Vcorresponding edge bar; c) positioning each support bar extension section in a corresponding transverse hole in one of the edge bars; d) fixing the screen in position, preferably by welding the support bar extension section to the edge bar; and Se) optionally, dressing the weld to provide a flat finish.

SIn an alternative embodiment, the screen may be pressed into frictional engagement with the edge bar, an adhesive may be used or the end may be riveted.

The method may include the step of positioning edge bars on a first side and a second side of the screen to form the grate. The method may also include the step of forming an angular deviation in the grate by inserting support bar extension sections of support bars in apertures in an end bar which is inclined to the perpendicular of longitudinal wires in the screen and fixing them in place.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is an exploded view of the components of a metal grate of the present invention aligned for assembly.

Figure 2 is the metal grate of Figure 1 when assembled.

Figure 3 is a perspective view of a further embodiment of a metal grate of the present invention including a right angle bend with some of the components aligned for assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to Figure 1 there is a seen a metal grating comprising components aligned for assembly. The components are a wire screen 20 and first edge bar 30 and second edge bar 31. The wire screen is formed from an array of longitudinal wires 21 with a first edge wire 22 and second edge wire 23. The wires are supported and held in place by support bars 24. The support bars 24 are positioned transverse to the longitudinal wires which are fixed to them preferably by welding. Each 00 4

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N support bar 24 has a support bar extension section 25, 26 at each end, formed by the support bars extending outwardly and beyond the first edge wire 22 and second edge wire 23, respectively. In some embodiments, the support bar extension sections may be formed on only some of the support bars provided there is a sufficient number to provide adequate strength and Istability in the grates when formed.

The edge bars 30, 31 each have a plurality of holes or N apertures 32, 33 respectively which extend transversely across the edge 00 Sbars. The apertures are dimensioned to receive the support bar extension sections 25, 26.

This is more apparent in Figure 2 where the components have been pressed together. The support bar extension sections 26 are entered into corresponding apertures 33 on the first edge bar 31 and a similar process occurs in relation to the second edge bar 30. The apertures 32, 33 may be dimensioned to snugly receive their support bar extension sections to thereby provide an interference fit. In one embodiment, the support bar extension section may finish slightly clear of the edge bar 31 so that it may be riveted in position. Alternatively, a suitable adhesive may be used to attach the metal screen and edge bar. Preferably, however, the support bar extension sections are welded in position as shown by weld 34. The present arrangement provides easy access to the welding site unlike prior art arrangements. The weld may be easily performed and effectively, easily and aesthetically dressed to provide an appealing, strong and professional finish to the metal grate. The present invention provides a stronger finish as well as a more time effective assembly. Positioning of the support bars in corresponding apertures provides great strength in a vertical direction as a substantial portion of the edge bar is directly positioned under the support bar extension sections to provide vertical strength and support.

The first edge wire 22 and second edge wire 23 act as stops for entry of the support bar extension section and end in close abutment with the corresponding edge bar.

The edge wires 22, 23 and longitudinal wires 21 are all formed 00

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N in the present embodiment from wedge wire. The profile of wedge wire is atypically triangular in shape with apex downward to facilitate passage of any material that penetrates the uppermost gap between adjacent wires. In the screen, due to the downwardly directed triangular profile, any such material easily passes through the grate once it has penetrated the uppermost entry Ior mouth.

Figure 3 shows a variation including a right angle bend.

(Ni 0 Aligned portions comprising a wire screen 120, first edge bar 130 and second spaced edge bar 131 are shown as aligned for assembly to form first module 125. In this case, however, a second module 140 is shown positioned at 90 degrees to the longitudinal wires 123 of the first module 140.

The second module 140 terminates in an end bar 142 which includes a plurality of apertures 143 which in this case have received support bar extension sections from support bars 145. The longitudinal wires 144 abut the end bar 142. The end bar is inclined off the perpendicular to a longitudinal axis of the wires 144. It is, in effect, raked. The support bars 121 of screen 120 also have support bar extension sections 123 aligned to enter into corresponding apertures 143 to thereby butt up against the extension sections of the support bars 145 and further strengthen the array.

This arrangement provides a braced right angle bend with support on all sides of the metal screen. The edge bars may be welded in position. The support bars may be welded into the aperture, glued or pressed.

The present invention in general provides a strong aesthetically appealing and hygienic finish for a metal grate. It is preferred that the components are formed from stainless steel particularly for use in health oriented or harsh environments, however other metals may be used and indeed the present invention method may be used with alternative materials such as robust polymers.

A method of the present invention is shown in Figure 1 and comprises the steps of forming a screen with extension sections on one or more of the support rods of the screen. Apertures are formed in the edge bars and dimensioned to receive the support bar extension sections. The 00 6

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N edge bars are then aligned with support bar extension sections positioned to mate with corresponding apertures. The components may be pressed together. Retention of the components may be due to friction fit or alternatively a positive fixing such as welding, gluing, riveting, or similar process may be employed. The apertures or holes may be drilled, punched Ior preformed. The apertures and nested support bar extension sections may be plug welded to provide an aesthetically appealing, inapparent finish.

(The present invention provides a number of advantages 00 including the option to support a load on all support rods. The grate strength is independent of the strength of fillet welds between edges and support bars. The present process is particularly well suited to automated welding.

Most welding is on an outside, accessible surface and easily dressed. The present invention allows the use of thinner edge bars thereby decreasing the cost of production. The edge bar thickness may be reduced to better match the visual balance of the grate.

Throughout the specification the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. It will therefore be appreciated by those of skill in the art that, in light of the instant disclosure, various modifications and changes can be made in the particular embodiments exemplified without departing from the scope of the present invention.

Claims

1. A grate comprising: a screen, the screen formed by an array of longitudinal wires, the array having a first edge wire and a second edge wire and a plurality of Isupport bars transverse to and fixed to the array; support bar extension sections each formed by a support bar 0 extending beyond one of the edge wires; and one or more edge bars, each edge bar having two or more transverse holes extending across the edge bar; wherein the support bar extension sections are entered into corresponding transverse holes and fixed in position.

2. The grate of claim 1 wherein the grate is formed from stainless steel and the array of longitudinal wires is formed from wedge wire.

3. The grate of any one of the preceding claims wherein the support bar extension sections are fixed in position by welding, riveting, interference fit, or an adhesive.

4. The grate of any one of the preceding claims further including one or more end bars with one or more holes, each of the holes extending across the end bar and adapted to receive a support bar extension section when the end bar is inclined away from perpendicular to a long axis of the longitudinal wires.

A method of forming a grate, the method comprising the steps of: forming a screen having support bars with one of more support bar extension sections; forming two or more transverse holes in at least two spaced edge bars, each transverse hole extending across the corresponding edge bar; 00 8 C positioning each support bar extension section in a a corresponding transverse hole in one of the edge bars; fixing the screen to the edge bars;

6. The method of claim 5 further comprising the step of fixing the screen IDin position by welding support bar extension sections to the edge bars. c

7. The method of claim 6 further including the step of dressing the weld oo 00 Sto provide a flat finish. c-I

8. The method of claim 5 wherein fixing the screen in position includes one or more of pressing the support bar extension sections into frictional engagement with the edge bars, using an adhesive to fix the support extension sections in position or riveting the ends of at least one support bar extension section.

9. The method of claim 5 further including the step of forming an angular deviation in the grate by inserting support bar extension sections of support bars in apertures in an end bar, the end bar inclined to the perpendicular to the longitudinal wires and fixing the support bar extension sections in place.

A grate substantially as described herein with reference to FIGS 1 and 2.

11. A grate substantially as described herein with reference to FIG. 3.