AU2001100037A4 - Grating Manufacture. - Google Patents

Description

GRATING MANUFACTURE The present invention relates to gratings useful as platforms or walkways in factories or other industrial installations, and in buildings, etc.

In the past, one particular kind of grating comprised a number of parallel bars called "load bars" extending between side edge bars called "trim bars". The load bars have been welded to the trim bars from "inside" where they abut on the inside faces of the trim bars. Reinforcing struts are usually provided which extend across the parallel load bars and in the same general longitudinal direction as the trim bars.

In the past, the welding process at the trim bars has been slow and tedious and is a major contributor to the costs of the grating. Therefore, there is a need for a simpler, faster and less expensive process for welding in order to affix trim bars to load bars to produce a finished grating.

An object of the present invention is to provide a process for forming an edge of a grating and also to provide a simpler, faster and less expensive process for welding to affix trim bars to the parallel load bars and thereby to produce a distinctive and attractive grating at a competitive price.

It has been found that the welding process of the trim bars to the free ends of the load bars will be simpler and faster if the trim bar has apertures and the weld position is accessed from "outside" of the trim bar through the apertures compared to the prior art where the weld is applied from "inside".

This in turn will lead to cheaper manufacturing because less skilled or unskilled labour can be used or perhaps even robotic welding devices can be used.

It has also been found that there will be no need for any finishing operations such as grinding, if the weld fillets are located below the plane of the outer surface of the trim bar. It is also possible to make the joints between free ends of the load bars and the trim bars more attractive in appearance and equal in strength.

Accordingly, there is provided a process for manufacturing a grating, said process including: arranging a number of load bars in spaced parallel relationship to form a central body of the grating; providing at least one trim bar to be fixed to generally aligned free ends of the load bars, the trim bar being provided with apertures therethrough which can locate adjacent to respective free ends of the load bars; and locating the trim bar abutting the free ends of the load bars and affixing the trim bar to the load bars including performing a welding process from outside of the trim bar by forming welds through the apertures to affix the trim bar at each aperture to the respective adjacent free end of one of the load bars.

There is also provided a grating including:spaced parallel load bars; and two parallel opposite trim bars each having multiple apertures along its length welded to respective free ends of the parallel load bars wherein the weld fillets having been formed by performing a welding operation through the apertures to affix the respective trim bars at the apertures to the adjacent free ends of the respective load bars, and wherein the weld fillets are located below the plane of the outer surfaces of the said trim bars.

In the preferred process the spaced parallel load bars and longitudinal reinforcing struts can be assembled and fastened together e.g. by welding, in conventional manner. The two spaced and parallel trim bars are then affixed to the free ends of the load bars. It may not be necessarily to affix every parallel load bar, e.g. every second, third, fourth or fifth parallel load bar may be welded to the trim bar. Each trim bar has apertures through which welding operations can be carried out to fix the free ends of the parallel load bars to the trim bar.

The parallel load bars terminate at their free ends at points extending along a longitudinal line where a trim bar is to be affixed. The trim bar is provided with apertures accessible from the "outside" of the grating when the trim bar is located in position so that the apertures at least generally align with respective free outer ends of the load bars of the grating. There does not need to be a hole for every bar every second, third, fourth or fifth bar for example may be in registry with an aperture in the trim bar. Finally, the trim bar is fixed in position to the outer free ends of the load bars by welding the trim bar to the outer ends accessed through the respective apertures.

In another broad aspect, the present invention also relates to grating manufactured from a trim bar having multiple apertures along its length through each of which, when registered with a respective free end of a spaced parallel load bar of the grating, a weld has been formed to weld the trim bar to a respective outer end of the load bar.

Possible and preferred features of the present invention are shown and illustrated in the accompanying drawings. However, the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the present invention. In the drawings: Figure 1 shows a perspective view of a portion of prior art grating.

Figure 2 shows a perspective view of a portion of a grating of the present invention.

Figure 3 is a plan view of a portion of a grating of the present invention as shown in Figure 2.

Figure 4 is an alternative embodiment of a grating of the present invention.

In Figure 1, the prior art grating has a number of parallel load bars (1) extending between the trim bars and reinforcing struts extending across the parallel bars and in the same general longitudinal direction as the trim bars The welds (10) are formed by inserting the weld from the inside position, generally from the position of the viewer of the drawing.

In the particular embodiment of the present invention shown in Figures 2 and 3, the grating of the present invention has on the far side a trim bar (2a) already secured to the load bars and has at the near side a trim bar (2) about to be located in position ready for welding. The apertures in the trim bar are formed by punching or pressing out to one side of the trim bar tongues or the like. Each tongue is pressed inwardly by greater than the thickness of the trim bar so as to enable a weld to be applied through the aperture to weld the end of the tongue and/or the adjacent edge of the aperture to the free end of the respective load bar The spacing of the tongues is such that they register with the free ends of the load bars The tongues do not need to all touch the face of the respective free ends of the load bars to which they are to be welded a clearance of preferably 1-2mm enables a satisfactory weld fillet to be applied to securely affix the trim bar to the free ends of the load bars.

As shown in Figure 3, most of the tongues are pressed out of the trim bar so as to be all directed in the same direction except for the last tongue which is in the opposite direction, at one end of the grating. This tongue (6) therefore is appropriately positioned to be welded to the end edge piece In the alternative embodiment of the present invention shown in Figure 4, the ends of the load bars register with the apertures provided in the trim bar In this case, the apertures are punched out entirely. The necessity of reasonably accurate registry of the apertures in the trim bar with the ends of the load bars may require a closer and greater manufacturing tolerance than the embodiments of Figures 2 and 3. However, the ends of the load bar when registered with the respective apertures are located below the plane of the outer surface of the trim bar so that a weld can still be applied from the "outside" into the apertures without the metal of the weld fillet projecting above the plane of the outer surface of the trim bar.

The formation of the apertures whether by pressing the tongues inwardly in the embodiment of Figures 2 and 3 or whether by forming the completely open apertures in the alternative embodiment of Figure 4, is a simple manufacturing operation. Preferably, the apertures can be formed by an appropriate punching operation using a die so that tongues are formed from the metal of the trim bar in a punching or stamping operation.

It is to be understood that various alterations, modifications and/or additions may be made to the features of the possible and preferred embodiment(s) of the invention as herein described without departing from the scope of the invention as defined in the claims.