Weir grate

Abstract

A weir grate (10, 100) comprises a base tray (12, 112) having an outlet (14, 114), and an infill tray (16, 116) positionable in the base tray. The base tray comprises a plurality of discretely positioned posts (22, 122) projecting upwardly therefrom in use. The infill tray comprises a plurality of correspondingly positioned locators (40, 140) projecting downwardly therefrom in use. Each locator is arranged for engaged with a respective post when the infill tray is positioned in the base tray.

Claims

1. A weir grate comprising a base tray having an outlet, and an infill tray positionable in the base tray, wherein the base tray comprises a plurality of discretely positioned posts projecting upwardly therefrom in use, and the infill tray comprises a plurality of correspondingly positioned locators projecting downwardly therefrom in use, each locator arranged for engaging with a respective post when the infill tray is positioned in the base tray; wherein, when the infill tray is positioned in the base tray, the infill tray defines a waterway that surrounds the infill tray and that is located between the infill tray and the base tray.

2. A weir grate as claimed in claim 1 wherein each post is solid and each locator is tube-like to closely receive its respective post therein once the infill tray is positioned in the base tray.

3. A weir grate as claimed in claim 2 wherein at least one of the tube-like locators is provided, at its distal end, with a cut-out in a tube wall, and at least one corresponding post is provided with a projecting lug located for aligning with and for snug receipt in the cut-out once the infill tray is positioned in the base tray.

4. A weir grate as claimed in claim 1 wherein a proximal end of each post is shaped for fastening in a corresponding hole defined in the base tray, and wherein a proximal end of each locator is shaped for fastening in one or more corresponding apertures defined in the infill tray.

5. A weir grate as claimed in claim 4 wherein the proximal end of each locator is castellated to define protruding lugs thereat that are shaped for being fasteningly received in corresponding slots defined in the infill tray.

6. A weir grate as claimed in claim 1 further comprising a plurality of seals, with each seal being shaped for positioning at a circumferential groove defined in a distal end of each post, and being shaped so as to sealingly engage the locator once the infill tray is positioned in the base tray.

7. A weir grate as claimed in claim 6 wherein each seal comprises a gasket of elastomeric material that is deformed between the locator and around the post once the infill tray is positioned in the base tray.

8. A weir grate as claimed in claim 1 wherein the posts are spaced discretely and evenly around an interior of the base tray, and so as to evenly space a periphery of the infill tray from an internal surface of the base tray.

9. A weir grate as claimed in claim 1 wherein the outlet is centrally located in a base plate of the base tray, and the base plate is stepped down to the outlet.

10. A weir grate as claimed in claim 9 wherein the outlet comprises a hole in the base plate, and a given size of outlet pipe that extends down from the base plate is mounted at the outlet hole.

11. A weir grate as claimed in claim 1 wherein the infill tray comprises a plate, optionally with an upstanding wall defined around a periphery of the plate.

12. A weir grate as claimed in claim 1 that is of sheet metal.

13. A weir grate as claimed in claim 12 wherein the sheet metal is of stainless steel or another ferrous or non-ferrous metal.

14. A method for constructing from sheet metal a weir grate as claimed in claim 1, the method comprising the steps of: forming respective apertures, at locations that correspond to each of the posts and locators, in suitably sized metal sheets for each of the base and infill trays; press-forming the base tray and optionally the infill tray from the metal sheets; fastening a proximal end of each of the posts and locators at a respective aperture.

15. A method as claimed in claim 14 wherein the apertures are formed by being punched or cut in the sheet for each of the base tray and infill tray.

16. A method as claimed in claim 15 wherein the apertures that are formed in the sheet for the base tray comprise circular holes for fasteningly receiving therein a circular projection defined at the post proximal end, and wherein the apertures that are formed in the sheet for the infill tray comprise arc-shaped slots for fasteningly receiving therein a projection from the locator proximal end that has a correspondingly arced profile.

17. A method as claimed in claim 16 wherein each circular projection is welded in its hole, and wherein each arced projection is stamp- or rivet-fastened in its slot.

18. A method as claimed in claim 14 wherein each suitably sized metal sheet for each of the base tray and infill tray is first punched or cut from a larger metal sheet.

19. A method as claimed in claim 14 wherein each suitably sized metal sheet is press-formed so as to form a plate and to fold up peripheral walls about the plate.

20. A method as claimed in claim 19 wherein, when the weir grate comprises three or more sides, the peripheral walls are folded up so as to each define a respective side and whereby edges of adjacent peripheral walls abut or closely face.

21. A method as claimed in claim 20 wherein, after folding up, the adjacent edges are welded together and then grinded.

22. A method as claimed in claim 19 wherein the plate for the base tray is press-formed so as to slope towards the outlet.

23. A method as claimed in claim 22 wherein the plate is press-formed or stamped so as to step down towards the outlet.

24. A method as claimed in claim 14 comprising a further step of positioning the infill tray in the base tray so that each locator engages with a respective post.

25. A method as claimed in claim 24 wherein a sealing gasket is located on a distal end of each post prior to the step of positioning the infill tray in the base tray.

26. A method as claimed in claim 24 wherein an outlet pipe is fastened to a plate of the base tray prior to the step of positioning the infill tray in the base tray.

27. A method as claimed in claim 14 wherein an overlay is connected to the infill tray prior to or after the step of positioning the tray in the base tray.

28. A method of installing a weir grate as defined in claim 1, the method comprising the steps of: connecting the outlet of the base tray to a drain pipe; attaching an overlay to the infill tray; positioning the infill tray in the base tray.

29. A method as claimed in claim 28 wherein an outlet pipe that is fastened at the base tray outlet is connected to the drain pipe.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Notwithstanding any other forms which may fall within the scope of the grate, base tray, outlet pipe, construction method and installation method as defined in the Summary, specific embodiments will now be described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1A depicts in plan elevation a base tray for a first weir grate embodiment;

(3) FIG. 1B depicts in plan elevation an infill tray for the first weir grate embodiment;

(4) FIG. 1C depicts in a sectioned side elevation the first weir grate embodiment in an assembled configuration;

(5) FIG. 2a depicts in side elevation a locator tube for mounting to the underside of the infill tray of FIG. 1B;

(6) FIG. 2b depicts in plan elevation a locator tube for mounting to the underside of the infill tray of FIG. 1B;

(7) FIG. 2c depicts in side elevation a post for mounting to the upperside of the base tray of FIG. 1A;

(8) FIG. 2d depicts in plan elevation a post for mounting to the upperside of the base tray of FIG. 1A;

(9) FIG. 3a depicts in front enlarged elevation of the locator tube of FIGS. 2a and 2b;

(10) FIG. 3b depicts in side enlarged elevation of the locator tube of FIGS. 2a and 2b;

(11) FIG. 3c depicts in plan enlarged elevation of the locator tube of FIGS. 2a and 2b;

(12) FIG. 3d depicts in side enlarged elevation the post of FIGS. 2c and 2d;

(13) FIG. 3e depicts in plan enlarged elevation the post of FIGS. 2c and 2d, and

(14) FIG. 3f schematically depicts the loads absorbed by a gasket located at a distal end of the post;

(15) FIG. 4A depicts in plan elevation a base tray for a second weir grate embodiment;

(16) FIG. 4B depicts in plan elevation an infill tray for the second weir grate embodiment;

(17) FIG. 4C depicts in a sectioned side elevation the second weir grate embodiment in an assembled configuration;

(18) FIG. 5a depicts in front elevation a locator tube for mounting to the underside of the infill tray of FIG. 4B;

(19) FIG. 5b depicts in side elevation a locator tube for mounting to the underside of the infill tray of FIG. 4B;

(20) FIG. 5c depicts in plan elevation a locator tube for mounting to the underside of the infill tray of FIG. 4B;

(21) FIG. 5d depicts in side elevation a post for mounting to the upperside of the base tray of FIG. 4A;

(22) FIG. 5e depicts in plan elevation a post for mounting to the upperside of the base tray of FIG. 4A;

(23) FIG. 6 depicts in a sectioned side elevation a third weir grate embodiment in an assembled configuration, illustrating a stepped down configuration in the base tray;

(24) FIG. 7 schematically depicts a detail of part of the stepped down configuration in the base tray, illustrating how differently sized outlet pipes can be mounted at different steps;

(25) FIG. 8 depicts in perspective view an outlet pipe that is adapted for mounting at a given step, as well as a securing mechanism for fastening the outlet pipe to the base tray;

(26) FIG. 9 schematically depicts part of a tube-shaped locator and a sectioned portion of a post, illustrating the interlocking arrangement between the two;

(27) FIG. 10 schematically depicts how this interlocking arrangement prevents rotation of the infill tray with respect to the base tray;

(28) FIG. 11 schematically depicts a section through a tube-shaped locator and a portion of a post, illustrating how water W can drain therefrom;

(29) FIG. 12 schematically depicts a corner portion C of either an infill tray or base tray, illustrating a fold-up F of the tray sides, as well as the location for a corner weld and finishing grind G;

(30) FIG. 13 depicts a corner portion of either a weir grate, showing the arc-shaped slots formed in the infill tray with the locator tube lugs having been stamped/riveted therein;

(31) FIG. 14 schematically depicts the cutting of a tube T of standard size to produce a number of like adjacent tube-like locators from a single feed of tubestock;

(32) FIG. 15A depicts in plan elevation a base tray for a fourth weir grate embodiment;

(33) FIG. 15B depicts in plan side elevation an infill tray for a fourth weir grate embodiment;

(34) FIG. 15C depicts in sectioned side elevation an assembled weir grate for a fourth weir grate embodiment;

(35) FIG. 16A depicts the fourth weir grate embodiment using enlarged sectioned side elevation; and

(36) FIG. 16B depicts the fourth weir grate embodiment using enlarged sectioned detail elevation;

(37) FIG. 16C depicts the fourth weir grate embodiment using enlarged sectioned detail elevation; and

(38) FIG. 17A depicts in plan elevation a base tray for a fifth weir grate embodiment, being similar to the embodiment of FIGS. 15 and 16.

(39) FIG. 17B depicts in plan side elevation an infill tray for a fifth weir grate embodiment, being similar to the embodiment of FIGS. 15 and 16.

(40) FIG. 17C depicts in sectioned side elevation an assembled weir grate for a fifth weir grate embodiment, being similar to the embodiment of FIGS. 15 and 16.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

(41) Referring firstly to FIGS. 1A to 1C, a first weir grate is shown in the form of a grate 10 (FIG. 1C). The grate 10 comprises a base tray 12 that is press-formed from sheet metal, the tray having an outlet in the form of a centrally located circular hole 14. The grate 10 further comprises an infill tray 16 press-formed from sheet metal, the infill tray being positionable in the base tray 12 to define the waterway W of the grate in use.

(42) The infill tray comprises four holes 17 punched or cut therein for drainage. An overlay in the form of a suitable surface cap or layer (superstrata) can be adhesively fastened in the infill tray (e.g. prior to finally locating the infill tray in the base tray on site).

(43) An outlet pipe in the form of a first pipe fitting 18 is connected to a plate 20 of the base tray 12 at the hole 14. As shown in FIG. 1C, the plate 20 slopes down to the hole 14 from a peripheral wall of the base tray to promote water flow through the weir grate.

(44) Referring specifically to FIG. 1A, the base tray 12 shown has four side walls 21 and has a square configuration. However, it should be appreciated that the base plate and, in turn, the infill tray and weir grate can have three, five or any desired number of sides, or can be circular, elliptical, etc.

(45) The base tray 12 comprises a plurality of discretely positioned posts in the form of four evenly spaced, solid metal pedestals 22 that are connected to the plate 20 at a stepped region 23, adjacent to the respective corners of the base tray 12, to project upwardly therefrom in use. Each pedestal is located at and is surrounded by a boss 24 that is preformed in the plate 20 during its press forming.

(46) The pedestals enable the infill tray to be easily and evenly located in use with respect to the base tray. The use of pedestals also enables the base tray to be press-formed from sheet metal. In this regard, a metal sheet for the base tray can be punched or cut (e.g. by laser) from a larger metal sheet and can then be press-formed into the tray shape shown. Because the pedestals can be later easily mounted to the base tray, the manufacture of a more complicated cast to achieve the same outcome is not necessary. This enables the base tray to be produced in a low-cost and high-volume manner, also using less material than a casting (e.g. a thinner walled product can be produced).

(47) Each pedestal 22 can be machined (e.g. in a CNC lathe) from a solid metal rod of standard, widely available rodstock. This further reduces manufacturing time and cost. Where a more complicated pedestal shape is required (e.g. a haunched shape) the pedestals can be cast (e.g. from stainless steel using investment casting). In either case, the pedestals can be mass produced and then stockpiled ready for use.

(48) As best shown in FIG. 3d a proximal end 22p of each pedestal is shaped to define a stud 26 for fastening in a corresponding hole 28 (FIG. 1C) punched or cut (e.g. by laser) in the base tray. The stud can be welded, riveted or stamped in its corresponding hole.

(49) In an alternative, each pedestal can have a flat base (i.e. no stud 26) and can be inserted into a hole in the base tray that received the pedestal body 34 therein. The underside of the pedestal can then be filet welded to the base tray. To facilitate this welding, for example, the weir grate can be assembled (i.e. infill tray inserted into the base tray), the weir grate inverted, and the pedestal bases then welded into position.

(50) As also shown in FIG. 3d a distal end 22d of each pedestal is shaped to define a head 30 connected via a neck 32 to a body 34 of the pedestal. This enables an elastomeric gasket 36 to be releasably fastened to the pedestal distal end in the groove defined between the head 30 and body 34, around the neck 32. The gasket 36 is shaped to protrude both vertically and laterally with respect to the pedestal to both secure the infill tray and provide cushioning/impact absorption and lateral support (FIG. 31) as will be described below.

(51) FIGS. 3d and 3e also show that at least one of the pedestals 22 is provided with a corresponding projecting lug 37 that is located at the proximal end thereof. This lug can align and interlock with a locator component of the infill tray 16, as described below.

(52) Referring specifically to Figure IB, the infill tray 16 shown also has four corresponding side walls 38 and has a square configuration (but can have three or a multiple number of sides, be circular, elliptical, etc.). The infill tray is sized smaller than the base tray so as to define a suitable/desired size of waterway W.

(53) The infill tray 16 comprises a plurality of discretely positioned locators mounted thereto in the form of four evenly spaced tube supports 40 that are connected to the underside of a flat plate 41 of tray 16, adjacent to the respective corners thereof, to project downwardly therefrom in use. The tube supports 40 correspond to the pedestals 22 and enable the easy and correct positioning of the infill tray in the base tray, as well as ensuring that the infill tray is evenly spaced and is supported on and above the base tray in use.

(54) Again, by employing tube supports 40 that can be later mounted to the infill tray, the infill tray can be punched or cut from a larger sheet of metal and then press-formed into the tray shape, avoiding the need for a more complicated casting procedure. Again, this contributes to the grate being produced in a cost effective and mass-produced way.

(55) As illustrated in FIG. 14, each tube support 40 can be cut (e.g. by laser) from a metal tube T of standard, available tubestock dimension. FIG. 14 also illustrates how the cutting can be controlled whereby each cut defines the ends of adjacent tube supports, thereby minimising material wastage, whilst at the same time defining a suitable shape at the proximal end of each tube support for later mounting.

(56) As shown in FIGS. 1C, 4C and 11, the pedestals and tube supports are dimensioned so that each tube support 40 snugly receives its respective pedestal 22 therein once the infill tray is positioned in the base tray. This enables the vertically and laterally protruding gasket 36 to deform against the interior surfaces defined within the tube support, once the infill tray is fully positioned in the base tray. This deformation helps secure the infill tray to the base tray, with the gasket providing a frictional retention function, as well as providing impact absorption and cushioning for various loads (lateral, vertical etc) placed on the infill tray in use (as illustrated by FIG. 3f).

(57) As shown in FIGS. 3a to 3c and FIG. 9, at least one of the tube supports 40 is cut (e.g. by laser) at its distal end 40d with a cut-out 42 in the tube wall. The corresponding projecting lug 37 of pedestal 22 aligns with and is snugly received in the cut-out 42 once the infill tray is positioned in the base tray (as illustrated in FIG. 9). This interlocking interaction of the pedestal lug 37 with cut-out 42 functions to prevent rotation of the infill tray with respect to the base tray (as illustrated in FIG. 10). However, the alignment is such as to still allow for easy removal (lifting off) of the infill tray 16 from base tray 12 for servicing etc. The cut-out and lug can be provided at just one (or a predetermined number) of the pedestal and tube support combinations to ensure foolproof assembly of the weir grate.

(58) As illustrated in FIG. 3b, a proximal end 4Op of each tube support 40 is castellated to define two opposing and protruding arced lugs 44 thereat. Each lug can be snugly (e.g. interferingly) received in a correspondingly arced slot 46 defined (e.g. punched or cut) in the infill tray 16 (as illustrated in FIG. 13). Two such slots for the two opposing arced lugs 44 are provided adjacent to each corner of the infill tray 16. Once the lugs are so located, a final fastening of the arced lugs in their respective arced slots can be by way of stamping or riveting.

(59) Referring now to FIGS. 4 and 5, where like reference numerals are used to denote similar or like parts, a smaller weir grate 10 is shown that has a relatively larger outlet 14 as well as a larger outlet pipe 18 (i.e. larger than outlet pipe 18). The grate 10 has essentially the same configuration as the grate 10 of FIG. 1C, except that the pedestals 22 are located on an in-use horizontal section of plate 20 defined between two spaced steps 23 and 50.

(60) Referring now to FIG. 6, where like reference numerals are used to denote similar or like parts, a weir grate 10 is shown that comprises a modified base tray 60. Base tray 60 comprises a multiple-step down configuration in the plate 20 to enable the easy and rapid mounting of differently sized outlet pipes to the weir grate (i.e. to produce weir grates with different sized outlet pipes from the one base tray). In this embodiment, plate 20 comprises a series of steps 23, 62 and 64 which have been stamp-formed in the plate 20 to step down to the hole 14, whereby a lowermost of the steps is surrounded by a next uppermost step, and so on. Notwithstanding such steps, the plate 20 still generally slopes down to the outlet to maintain water flow through the weir grate.

(61) When the hole 14 is increased with reference to a given step (e.g. by punching, laser-cutting etc) a successively larger outlet pipe, such as a pipe 70 or a pipe 72 can be attached thereto.

(62) FIGS. 7 and 8 illustrate a special configuration for one such pipe 70 suitable for mounting to the base tray (16 or 60). The pipe 70 comprises a peripheral flange 74 that projects laterally from a proximal end 7Op of pipe 70. The thickness and width of the flange 74 is selected to correspond to the depth and width of its corresponding step. Thus, when the pipe 70 is mounted to the plate 20, an in-use upperside of the flange sits flush with an in-use upperside of a next adjacent step. This can define a near continuous surface where the flange peripheral edge meets the step, which tends to prevent residual waste water remaining in the weir grate.

(63) A sealing ring (e.g. an elastomeric O-ring) may also be located under the flange 74. Thus, when pipe is mounted to the base tray the flange 74 can be fastened against an upperside of a given step of plate 20.

(64) As schematically shown in dotted outline in FIG. 8, the pipe 70 can include an internal step 75 located intermediate ends of the pipe. The step can receive and locate thereat a foreign matter trap for e.g. waste, hair, items such as jewelry, and to prevent vermin, insects (such as mosquitoes), odours etc from entering up from or breeding in the drainage waste water.

(65) To securely fasten the pipe 70 to the base tray during manufacture of the base tray, a plate-shaped retaining ring 76 (such as a washer) is fastened in a tight fit and so as to surround the pipe at an underside of the step, opposite to the step upperside of plate 20. The plate ring is retained on the outlet pipe by a clip band 78 that is spot-welded at 79 to the outlet pipe's external surface.

(66) Alternatively, as schematically shown in dotted outline in FIG. 8, the ring may be replaced with a mating sleeve 77 that comprises a flange F projecting laterally from and around its upper periphery, so as to sit at the underside of the step when fastened to surround the pipe 70. To simplify manufacture, each outlet pipe 18, 70, 72 can correspond to increasing standard sized pipes, which in turn can then easily be mounted to standard drainpipe diameters. The plate 20 can thus be stepped and the outlet 14 can thus be sized in relation to a standard sizing/format.

(67) Whilst the outlet pipes are typically circular in cross-section, whereby each step is then concentric with the outlet, they may have other cross-sectional shapes as desired. However, when connected to a standard drain, a circular shape is desirable to match the drain.

(68) The base tray 60 is suitable for use in the weir grates of FIGS. 1 and 4, but can alternatively be used in other (e.g. known) weir grates.

(69) Referring now to FIGS. 15 and 16, a weir grate 100 is shown that comprises a modified base tray 112 and a modified infill tray 116.

(70) The modified base tray 112 again comprises a step down configuration and has an outlet hole 114 for a pipe fitting 118 to the weir grate. The base tray 112 comprises a plate 120 which generally slopes down to the outlet hole to maintain water flow through the weir grate.

(71) The base tray 112 again comprises four evenly spaced bosses 124 and holes 128 in plate 120 to mountingly receive the studs 126 of four respective pedestals 122, one pedestal having a projecting locator lug 137. The square plate 120 is surrounded by four side walls 121 that are again press formed.

(72) The modified infill tray 116 again comprises four holes 117 punched or cut in the plate 141 for drainage, and four pairs of arced slots 146 punched or cut therein to mountingly receive four respective tube supports 140.

(73) The base tray 112 is modified by forming (e.g. press forming or attaching) a lip in the form of a peripheral flange 180 to extend laterally from the four side walls 121. As shown in FIG. 16, such a flange is able to support an overlying covering C (e.g. a floor covering such as one or more slabs or large format tiles, panels, pavers etc) at a periphery of the weir grate 100 in use.

(74) FIG. 16B shows a variation in which the flange 180 comprises a separate component that is mounted (e.g. press-fitted or welded) to the side walls 121. When the separate flange 180 is press-fitted to the side walls this may take place in-situ (i.e. at the time of installing the weir grate 100).

(75) To secure and seal between the separate flange 180 and the remainder of the base tray 112, a specially formed and sized elastomeric gasket can be provided that is arranged along the upper rim of the side walls 121. Press-fitting of the separate flange 180 onto the side walls then deforms this gasket, with this deformation securing the flange 180 to the walls and sealing therebetween.

(76) The infill tray 116 is modified in that the four side walls (e.g. walls 38 in the grate 10 of FIG. 1) are removed altogether from the plate 141. In other words, infill tray 116 simply comprises a flat plate 141, which is accordingly very easy to form and use. As again shown in FIG. 16, such a flat tray is able to support an overlying covering T, for example, a floor covering such as a slab-like material (e.g. a slab or large format tile/panel/paver formed from a natural or synthetic stone material). The flat tray supports the slab-like material centrally above the weir grate 100 in use. In this regard, the covering T can simply be adhesively fastened at its underside to the tray 116, with the sides of the covering just overhanging the tray as shown, to hide the tray 116 from view.

(77) The modified base tray 112 and infill tray 116 enable the weir grate 100 to be effectively hidden in use. Also, joints and corners can be covered and not seen down the weir passage. This can provide desirable aesthetic effects.

(78) Referring now to FIGS. 17A to 17C, where like reference numerals denote similar or like parts to the weir grate of FIGS. 15 and 16, a weir grate 100 is shown that comprises a modified base tray 112 and a modified infill tray 116 that are, in essence, the same as those shown in FIGS. 15 and 16.

(79) However, in the base tray 112 the flange 180 is provided with a plurality of discrete holes 182 therethrough (e.g. it is perforated). These holes can be punched or cut in the sheet prior to press-forming the base tray. The holes 182 enable better bonding of the flange 180 with an adhesive for the covering T.

(80) Further, in the infill tray 116 two spaced posts 190 are provided to project up from flat plate 141. These posts can be used to align with corresponding holes formed in the underside of covering T (FIG. 17C) to securely locate the covering at the infill tray 116.

(81) As explained above, the weir grates 10, 10, 10, 100, 100 can mostly be formed from sheet metal. The sheet metal may be of stainless steel or another ferrous or non-ferrous metal. Notwithstanding the use of sheet metal, the aesthetics and design features of the weir grate can be preserved.

(82) In the embodiments described the pedestals 22, 122 are spaced discretely and evenly around an interior of the base tray, and also so as to evenly space the walls/edges of the infill tray 16, 116 from an internal surface of the walls 21, 121 of base tray 12, 112 (i.e. to provide an even weir around the weir grate in use). However, spacing may be selected to provide an uneven weir profile if desired.

(83) In the embodiments described the tube support and pedestal height can be controlled to ensure an optimal spacing between the infill tray and base tray.

(84) Further, the selection and location of the pedestals can ensure a correct and foolproof positioning of the infill tray during installation.

(85) In the embodiments described the outlet hole is centrally located in the base plate, although in some applications a one-off base tray may be produced that has an off-centre outlet.

Example 1Method of Constructing a Weir Grate

(86) A method of constructing one of the weir grates 10, 10, 10 described comprised the following steps: 1. Determining, on a large stainless steel sheet, locations for the base tray 12 and infill tray 16, and for the apertures 28, 46 and holes 14, 17. 2. Punching or cutting (e.g. by laser) the respective apertures and holes, at locations that correspond to each of the pedestals 22 and tube supports 40, in suitably sized metal sheets for each of the base and infill trays. 3. Die-press or laser cutting-out the metal sheets for each of the base and infill trays. 4. Press-forming each of the base and infill trays from their respective metal sheets, so as to form the corners C by the folding up F of the walls (21 or 38) as shown in FIG. 12. During such press-forming the slope in the plate 20, 20 and the bosses 24 etc can be defined, and the steps 23, 50, 62, 64 can be stamped into the plate. 5. Welding together and the grinding smooth the corners C as shown by G in FIG. 12. 6. Machining from a standard rodstock (e.g. by CNC lathe) or investment casting each of the pedestals 22, including at least one pedestal per base tray that has a lug 37. 7. Cutting (e.g. by laser) each of the tube supports 40 from a standard tubestock (FIG. 14). 8. Weld-fastening the stud 26 of each pedestal 22 in a respective hole 28. 9. Fastening the lugs 44 of each tube support 40 in their respective arced slots 46 using stamping or riveting. 10. Fastening the outlet pipes 18 (or 70, 74) in their correspondingly sized holes 14, making use of the flange 74, the plate ring 76 and the spot-welded clip band 78. 11. Grinding and polishing any of the resultant pieces, as required/desired, to provide a suitable surface finish to the resultant weir grate. 12. In a factory or on-site, adhesively fastening a surface cap or layer to the infill tray. 13. Positioning the infill tray in the base tray so that each tube support 40 engages with and snugly receives a respective pedestal 22 therein. During this step the gasket 36 is deformed against the inside of the tube support walls. Positioning of the infill is completed when the upper surface of the gasket abuts the underside of infill plate 41. 14. Packaging the assembled weir grate, ready for shipping.

(87) It was noted that for smaller volume production runs laser cutting could be employed for the apertures and holes and to produce the suitably sized metal sheets for each of the base and infill trays. For larger volume production runs the apertures and holes could be punched into the sheets as they are formed as part of a die press-cutting operation.

(88) It was further noted that for a weir grate 100, 100 step 4. comprised press-forming only the base tray 112 from its respective metal sheet, and so as also to form the flange 180. No press-forming was required for infill tray 116.

Example 2Method of Installing a Weir Grate

(89) A method of installing one of the pre-packaged weir grates 10, 10, 10, 100 described above comprised the following steps: 1. Detaching the infill tray from the base tray so that each tube support 40, 140 releases its respective pedestal therefrom. 2. Connecting the outlet pipe 18 (or 70, 74, 118) of the base tray to a drainpipe. 3. Affixing the base tray in a floor (e.g. using a tiling cement, or other adhesive or fastener). 4. Adhesively fastening an overlay (e.g. a tile) in/to the infill tray. 5. Tiling (or otherwise covering) the floor up to (or over the flange 180 of) the base fray. 6. Re-positioning the infill fray in the base tray.

(90) In this installation method a base fray with the right-sized outlet pipe for the given drainpipe diameter is prior-selected.

(91) In this installation method the overlay may comprise a tile (or a part thereof) that matches the surrounding tiles used on the floor, or may comprise e.g. a decorative cap (such as of polished stainless steel), or other covering.

(92) Whilst a number of specific grate, construction and installation embodiments have been described, it should be appreciated that the grate and its method of construction and installation may be embodied in other forms.

(93) In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word comprise or variations such as comprises or comprising is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the grate and its construction and installation methods.