GB2475413A - Clogging resistant drain - Google Patents

Abstract

A drain cover plate 18 or grating is mounted to a component 16. A boss 68a exposed to drainage flow spaces the cover plate or grating from the component to define inlet slots (88a-d, Fig.11). An upper surface portion of the cover plate or grating meets a surface of the component to provide a substantially step-free junction which is clogging resistant. A releasable fastener 20 may extend into the boss allowing the cover plate/grating to be secured to the component and/or the component to be secured to a drain body 12. Again this minimises division of the drainage flow and filament snagging. The component 16 may be a membrane clamp ring or a floor tile bezel/adaptor.

Description

CLOGGING RESISTANT DRAIN

Field of the Invention

This invention relates to drains which are resistant to clogging by filamentary materials such as hair, lint and the like. It relates particularly but not exclusively to relatively high volume flow drains of this kind intended for use in floors, baths, showers, wetrooms, etc, both in domestic settings and for public and institutional use such as in hospitals, retirement homes, hotels and commercial kitchens, where good hygiene and low maintenance are advantageous.

Background of the Invention

A region where floor, shower and other similar drains are vulnerable to blockage is at or near the inlet flow area formed between the drain body and a grating or cover plate fixed over the inlet. This region will typically include a number of obstructions which divide the incoming waste water flow, such as mounting supports for the grating/cover plate, and the heads and/or shanks of screws or bolts for securing this or a clamping ring to the drain body. The clamping ring may be required to seal and secure a vinyl or similar flexible sheet floor covering, or a damp proof membrane incorporated in a floor structure, to the drain body. All such obstructions represent potential sites for blockage accumulation, e.g. by entangling filamentary materials present in the waste flow.

GB2012333 discloses a cup-and-dip tube sink or floor drain trap in which, in one embodiment, the cup is provided with a central upstanding pipe used e.g. for connection of a washing machine discharge hose. The cup is supported on the base of the drain body and is centrally located in the grate of the drain by the upstanding pipe. The lower end of the pipe is shaped as an inverted corrugated funnel which co-operates with a central upstand in the cup floor, to divide the water flow among an array of radial passageways. These obstruct and divide the water flow not only in the central pipe, but also around the lower edge of the dip tube, making the disclosed arrangement potentially more vulnerable to clogging.

The present applicant's patent GB2429216 discloses a cup-and-dip tube trap arrangement for a floor drain, in which the cup is suspended from the dip tube by a pair of hooks which engage with a corresponding a pair of ears on the rim of the cup. However, the hooks extend across the flow annulus formed between the dip tube and cup rim and can potentially snag hairs or similar filamentary material in the waste water flow.

EP1026330 and GB627911 likewise disclose drainage devices of the kind having a trap which comprises a passageway with an open lower end submerged in a body of water held within a reservoir to form an odour seal. The reservoir is at least partially supported on a fixture extending axially within the passageway. DE4437873 discloses a similar arrangement in which the reservoir is axially adjustable on a screw thread selectively to seal the passageway and form a plug. However in each case parts of the fixture extending across the fluid flow are exposed during no-flow conditions and so are potential snagging or entrapment points for filamentary material or other debris in the drainage flow. US4943 100 shows a drainage fitting having a recessed grating partially supported by bosses formed on an underlying component. The bosses also serve to accommodate screws for securing the component to the main body of the drainage fitting.

Summary of the Invention

The present invention aims to mitigate these problems and accordingly provides an assembly or kit of components as defined in claim 1. The substantially step-free junction is hydraulically efficient, reducing or substantially eliminating filamentary material snagging. It is also easy to clean without removing the grating or cover plate from the underlying component.

Also the boss carries out two functions: 1) to cooperate with a releasable fastener which passes through it e.g. to secure the cover plate or grating to the component, and/or to secure the component to a drain fitting; and 2) to provide a mounting area for the spaced mounting of the cover plate or grating on the component. Further separate mounting fins, arms, feet or other similar spacers extending between the component and the grating/cover plate through the fluid flow are therefore rendered unnecessary. There are therefore fewer obstructions which divide the waste fluid flow and which therefore could cause debris accumulation and lead to blockage of the drain.

A plurality of such bosses may be provided. These may form the sole mounting means for the cover plate or grating on the component. In this way the number of obstructions to fluid flow between the spaced component and cover plate/grating is minimised.

The cover plate or grating may be retained on the component by gravity or as a friction or interference fit. The friction or interference fit between the cover plate or grating and the component may be provided by a cooperating recess and protuberance. This provides for relatively easy removal of the grating/cover plate, e.g. for cleaning or maintenance of the drain. Greater security may be desirable e.g. in public or institutional settings, in which case the releasable fastener can pass through both the cover plate/grating and the component, e.g. to retain them both on the drain fitting. Preferably a plurality of the bosses and the releasable fasteners are provided, at least one of these releasable fasteners extending through the cover plate or grating, and at least another one of which does not, so that the component remains fastened to the drain fitting when the grating or cover plate is removed.

The component may comprise a clamping ring attachable to the drain fitting e.g. for securing a flexible sheet floor covering or a damp proofing membrane to the drain fitting.

Alternatively the component may be a separate bezel or floor tile adaptor in which the grating/cover plate is received.

The invention and some of its preferred features and advantages are further described below with reference to illustrative embodiments shown in the drawings.

Brief Description of the Drawings

Figure 1 is an exploded perspective view of a floor, wetroom or shower drain forming a first embodiment of the invention; Figure 2 is a vertical, slightly more than half-section of the drain of Figure 1 showing the components assembled; Figures 2A and 2B show alternative fixtures for connection between the passageway and the reservoir; Figures 2C and 2D being scrap cross-sections on lines IIC-IIC and lID-lID in Figures 2A and 2B respectively; Figure 3 is a plan view of a clamping ring used in the drain of Figure 1; Figures 4 and 5 are half-sections on lines IV-IV and V-V in Figure 3; Figure 6 is an underplan view of a cover plate used in the drain of Figure 1 (its curvature being shown exaggerated in Figure 1); Figures 7 and 8 are half-sections on lines Vu-Vu and Vill-Vill in Figure 6; Figure 9 is a side view of the cover plate juxtaposed for assembly with the clamping ring, the latter shown in half section; the juxtaposed parts embodying a kit according to the second aspect invention; Figure 10 shows the cover plate fitted within the clamping ring, thus embodying an assembly according to the second aspect of the invention, and Figure 11 corresponds to Figure 10, but shows the assembled parts in plan view.

As shown in Figures 1 and 2, a shower or floor drain fitting 10 comprises an assembly of the following parts: a body 12, a trap unit 14, a clamping ring 16, a cover plate 18 and releasable fasteners such as machine screws 20. The cover plate may be replaced by a grating, as well known.

The body 12 may be formed from cast metal such as aluminium, bronze, gunmetal, iron or any other metal or metal alloy known or suitable for such use in drainage fittings.

Alternatively, the body 12 may be formed from injection moulded plastics, such as uPVC, ABS, or glass fibre reinforced bulk moulding compound ("BMC"). The body has an integrally formed outlet spigot 22 for connection to pipework of a drainage system by a suitable pipe coupling (not shown). As illustrated, the remainder 24 of the body 12 is shaped as a generally circular bowl and the spigot 22 extends vertically downwards from a lowermost central part of this bowl. However, in variants (not shown) the spigot 22 may extend at any suitable angle from the vertical to the near horizontal, when the bowl 24 is installed with its axis vertical. Preferably no matter what the angle of the spigot 22 or the shape of the bowl 24, in each case the spigot 22 extends from a lowermost point of the bowl 24, so that the body 12 is free-draining. That is, apart from as explained later regarding the trap unit 14, the body 12 preferably contains no regions in which water or other effluent can "pond" or accumulate under no-flow conditions. Such ponding regions if present can allow sludge and other solids to settle out of the waste stream and accumulate to form blockages.

The spigot may be of 50 mm ID, and the drainage fitting may be capable of handling waste water flow rates of up to about 1.39 litres per second: more than twice the capacity of the Applicant's prior shower drains. However, the drain fitting 10 and its components can be sized as required to provide various different desired flow capacities and for use with various desired pipework sizes, both standard and non-standard. A shoulder 25 may be provided on the outside of the body 12 bowl portion 24, which forms a stop allowing the body to be push fitted directly into the end of a 110mm pipe. The same principle may be used for connecting the drain body to pipes of other sizes.

The upper rim of the bowl 24 comprises a horizontal securing flange 26 with screw holes 28 for securing the drain fitting 10 to a wooden floor deck or the like (not shown). However the drain fitting 10 may also be used in solid (e.g. concrete) floors as discussed below. An inflow slope 30 at an angle of approximately 60 degrees to the horizontal connects the flange 26 to a shelving region 32 sloping gently inwardly and downwardly. The shelving region 32 connects to the bowl 24 interior surface via a chamfer 34. The trap unit 14 is mounted to the chamfer 34 and to the immediately adjacent part of the bowl interior surface. The clamping ring 16 is mounted to co-operate with the shelving region 32 and with the inflow slope 30.

The mounting of the trap unit 14 and of the clamp ring 16 are each further described later.

The bowl 24 is provided with four exterior bosses 36 (only two of which are visible in Figure 1) which accommodate axial holes 38 for threaded reception of the fasteners 20. A pair of these holes 36 is visible in Figure 1, accommodated in the exterior bosses which are obscured in this Figure. Of course other numbers of holes 38 and fasteners 20 may be used and, instead of the bosses 36, the wall of the bowl may be otherwise thickened or shaped to accommodate the holes 38. Optionally, surface features such as circumferential or other ribs 40 may be provided on the body 24 exterior, for retaining the drain fitting 10 in a surrounding cast concrete floor slab or floor screed (not shown).

The trap unit 14 is accommodated in the bowl 24 of the drain fitting body 12, and may be removed through the open top of the body 12 e.g. for cleaning and maintenance purposes, once the cover plate 18 has been removed. With the trap unit and cover plate removed, there is relatively unrestricted access to the interior of the bowl 24, spigot 22 and connected pipework, e.g. for rodding or flushing. The removed trap unit is also easily cleared of sludge, hair and other accumulated debris.

The trap unit 14 comprises an upwardly open cup 42 which forms a reservoir for an odour seal. A dip tube 44 provides a generally vertically extending passageway 46 having an open lower end which is submerged in use in a body of water held within the cup 42, to form the water seal. The upper end 48 of the dip tube 44 is outwardly flared into a trumpet shape.

The flared end has a radially outwardly facing surface provided with a circumferential groove which accommodates an 0-ring seal 50. Alternatively the seal may be moulded onto the radially outwardly facing surface. The rim of the flared end above the groove or moulded on seal forms a projecting lip 52 of complementary profile to the chamfer 34. The lip 52 therefore serves to support the dip tube 44 in the bowl 24, with the upper surfaces of the flared end 48 and shelving region 32 flush with one another. With the dip tube in this position, the 0-ring 50 or moulded on seal forms a seal between the upper end of the dip tube and the inner wall of the bowl just below the chamfer 34. Waste water flowing across the shelving region is therefore directed into the dip tube, through the inside of the cup 42, over the lip of the cup 42, through the annulus between the outside of the cup 42 and the inside of the bowl 24, and then out through the spigot 22. The 0-ring together with the water seal also prevents air, gas and foul odours from any connected pipework from escaping up through the drain flitting 10.

The cup 42 is supported clear of the bottom of the bowl 24 on a fixture extending axially within the passageway 46. As shown in Figure 2, the fixture comprises a support rod 54 extending along the central axis of the passageway 46. A lower end of the support rod 54 is fixed, e.g. by a screw threaded connection, to a boss 56 standing up from the centre of the bottom wall of the cup 42. An upper end of the support rod 54 is fixed, e.g. by insert moulding, to the centre of a cross member 58 which extends diametrally within the dip tube 44 towards its upper end, proximate to the rim of the cup 42. Many other ways of securing the support rod 54 between the cross member 58 and the floor or bottom wall of the cup 42 will be readily apparent. For example, the ends of the rod may both be screw threaded into the cross member 58 and boss 56, or the lower connection may be by insert moulding and the upper by screw threads. In one arrangement an upper part of the support rod is integrally moulded with the cross member 58 and a lower part is integrally moulded upstanding from the centre of the floor inside the cup. The two parts are united by a nut and screw-threaded stud respectively insert moulded into their mating ends. Yet alternatively, the support rod 54 and cross member 58 may both be integrally moulded with the dip tube 44. A lower end of the support rod 54 can then be secured to the floor of the cup using any suitable means, such as adhesive, solvent or ultrasonic welding, with or without the use of a boss such as 56.

The cross member 58 shown in Figure 2 is of cranked form, so that its centre portion lies above the level of the rim of the cup 42; whereas its ends are attached to the inner walls of the dip tube 44 below the level of the cup rim. This means that the centre portion always extends above the trap water level under no-flow conditions, and can therefore be used as a convenient handle to extract the trap unit 14 from the drain body when desired, after removing the cover plate 18. At the same time, the ends of the cross member are always submerged in normal use and there is therefore a reduced tendency for filamentary material such as hair, lint and the like, to settle out of the waste water and become draped around and/or entangled with the cross member. If desired, the entire cross member can remain submerged in normal use. It is preferred that the cross member 58 is attached to the walls of the dip tube 44 not far below the level of the cup rim, so as to maximise the distance between the cross member and the open lower end of the dip tube 44. This may assist in reducing filament etc. entanglement, especially in the case of shorter filaments.

With a cup supporting fixture as shown in Figure 2, the cross member 58 represents substantially the only edge-like obstruction extending into the waste flow and providing a divide in the waste flow, downstream of the shelving area 32. Therefore if measures are taken to minimise filament entanglement as described above, the drain body 12 and trap unit 14 can be made to be largely self-cleaning, requiring little maintenance. Instead of suspending the cup 42 from the dip tube 44, alternatively the fixture may support the cup from the cover plate 18. For example in a variant of the Figure 2 embodiment (not shown) the cross member 58 may be omitted, the rod 54 extended upwardly and its upper end attached to the underside of the cover plate 18, e.g. via a screw threaded boss, or any other suitable connection. With this arrangement, the dip tube 44 will be loosely captive between the cover plate 18 and the cup 42 and the cover plate 18 will form a part of the trap unit 14.

When fitting the trap unit 14 into the drain body 12, it will be necessary to ensure that the lip 52 and o-ring 50 are properly seated, e.g. by pushing down on the flared end 48 of the dip tube 48 with a suitable tool inserted beneath the edge of the cover plate 18.

The cover plate can be spaced from or even attached to the flared end of the dip tube by suitable spacer feet, pillars or fins, by which the cover plate can be used to press the dip tube into sealing position across the upper end of the bowl 24. However care must be taken to minimise filament entanglement at such spacer feet, etc, as they represent a flow dividing, edge-like feature, as discussed below in relation to the spacer feet shown in Figures 1, 2 and 6-10, which are part of the separate cover plate 18. Uniting the cover plate 18 with the trap unit 14 may make the whole assembly more difficult to clean.

Examples of other possible forms of fixtures which can be used to secure the cup 42 to the dip tube 44 of the trap unit 14 are shown in Figures 2A -2D. In Figures 2A and 2C, the fixture is formed as a simple rectangular wall or plate secured across a diameter of the passageway 46 inside the dip tube 44. The upper edge of the plate 60 is preferably positioned just below the trap water level, so that the entire plate remains submerged in normal use, and the distance between the upper edge and the open lower end of the dip tube 44 is suitably great, to minimise filament entanglement. A lower end of the plate 60 protrudes a suitable distance beyond the open lower end of the dip tube 44, for attachment to the base 62 of the cup 42. The plate 60 therefore forms a fixture which extends axially within the dip tube 44 and attaches the cup 42 with its floor 62 at a suitable spacing from the lower end of the dip tube. The plate 60 may be provided with a through hole 64 by which the trap unit 14 may be hooked out of the bowl 24 after removal of the cover plate 18. The fixture shown in Figures 2B and 2D is similar to that of Figures 2A and 2C, except that the diametral plate 60 with its substantially horizontal top edge is replaced by a radial plate 66 having a downwardly and inwardly sloping top edge. The plates 60, 66 may be integrally moulded with the dip tube and secured to the floor of the cup e.g. by adhesive or solvent or ultrasonic welding or any other suitable means; or vice versa. Yet alternatively, either plate 60, 66 may be formed initially separately from both the dip tube and the cup and then secured to both of these by such means. Still other forms of fixture at least partly within the dip tube for securing its lower end to the floor of the cup at a suitable spacing, will be readily apparent.

Figure 3 shows the clamping ring 16 which is a component securable to the drain fitting 10 by the releasable fasteners or machine screws 20, as shown in Figure 1. As best seen in Figure 1, the clamping ring comprises a bottom flange 1 6a providing an undersurface having a shallow inward and downward slope corresponding to that of the shelving area 32 of the drain body 12. It further comprises a side wall 16b having an outer face with an approximate degree upward and outward slope corresponding to the angle of the inflow slope 30. The clamping ring 16 also has four bosses 68a-d with vertical through holes 70. The screws 20 pass through the holes 70 into the holes 38 to secure the clamping ring 16 with its flange 16a against the shelving area 32 and its side wall 16b against the inflow slope 30. A flexible waterproof floor covering or damp proofing membrane 72 can be trimmed into the inflow slope 30 and thus pinched circumferentially between this and the clamping ring side wall 1 6b.

Upper generally horizontal surfaces of the bosses 68a-d provide mounting areas for cooperation with spacer feet 74a-d formed on the cover plate 18 (or on the grating, if used in place of the cover plate. The following description applies equally to such gratings, but only the cover plate is specifically referred to, for brevity). The clamping ring also has raised portions 76a-d above and radially outward of each respective boss 68a-d, which provide opposed, vertical inwardly facing centring surfaces 78a-d for cooperation with vertical outer end faces 80a-d on the spacer feet 74a-d to maintain the cover plate centred in the clamping ring 16 when assembled. A pair of opposed frictional retention pips or studs 82a, 82b protrude from the centring faces 78a, 78c above the bosses 68a and 68c. The pips engage in complementary recesses 84a, 84b formed in the spacer foot end faces 80a, 80c. This locks the cover plate and clamping ring together against relative rotation. The pips are made slightly oversize compared to the recesses and/or the diametral separation of the pips is made slightly less than the diametral separation of the inner ends of the recesses, so that the cover plate 18 is a frictional or interference fit within the clamping ring 16. Optionally the pips and recesses can be omitted, with the cover plate being retained in position by holes and screws as described below.

The spacer feet 74a-d form laterally projecting parts of the cover plate 18. Upper surface portions of the cover plate on these projecting parts meet the surface of the component (i.e. clamping ring 16) to provide a substantially step-free junction. In the particular arrangement shown in the drawings, the surfaces on the clamp ring which provide this step-free junction are upwardly facing surfaces of the raised portions 78a-d. These surfaces as shown are at the same vertical height and have substantially the same slope as the projecting part surfaces at the meeting point, so that there is a smooth, substantially snag-free, stepless continuity between these cooperating surfaces. However, some difference in slope is permissible.

Moreover the slope of each of the component and cover plate/grating may change in this meeting region, i.e. one or both of these surface profiles may be curved rather than straight.

What is advantageous is that the absence of a substantial step means that the meeting surfaces contain no sharp discontinuities and are exposed for easy cleaning, including cleaning with the cover plate in place in the component i.e. clamp ring. The spacer feet or laterally projecting parts of the cover plate/grating at least partially form the ends of drainage inflow slots 88a-d having opposed edges defined by the component 16 and cover plate/grating respectively. Thus the spacer feet form drainage flow dividers. However the cover plate/grating and its junction with the surrounding component is designed to be hydraulically efficient and to maintain rapid and smooth drainage flow through the inflow slots. This substantially eliminates any tendency for hair or other filamentary material to become snagged around the laterally projecting parts/spacer feet and/or bosses, preventing any build up which could potentially clog the drain. The substantially stepless and therefore completely exposed configuration of the projection upper surface portions and the adjacent surface of the component are also easy to clean. Thus in the unlikely event that any filamentary material does become snagged (e.g. under low or zero flow conditions), it will be easily dislodged by wiping over the exposed top surface of the cover plate 18 and adjacent exposed surface of the clamp ring, with a mop, sponge, cleaning cloth, or the like; or it will be flushed away when the drain is next subjected to normal drainage flows. It is not necessary to remove the cover plate/grating from the drainage fitting for such cleaning, so the drain is substantially "zero maintenance".

Figure 9 shows the cover plate 18 being offered up for fitment to the clamping ring 16, with spacer foot 80b positioned above the mounting area of boss 68b, and spacer foot 80d positioned above the mounting area of boss 68d. With the cover plate and mounting ring in this relative orientation, the pip 82a is positioned for reception in the recess 84a (not shown) and the recess 84b is positioned for reception of the pip 82b (not shown). Figure 10 shows the cover plate 18 in position in the mounting ring 16, with the spacer feet 80a,b,d resting on the mounting areas of bosses 68a,b,d respectively. Boss 68c and spacer foot 80c are omitted in this sectional view. The spacer feet and bosses cooperate to hold edges of the cover plate (those edges between each foot) away from the upper surface of the clamping ring 16. In this way, the four inlet slots 88a-d are defined (Figure 11). Because the spacer feet 80a-d coincide with the bosses 68a-d, the number of edge-like obstructions dividing the inflowing drainage stream is minimised, and the requirements for securing the clamping ring 16 to the drain body 12 and for retaining and supporting the cover plate 18 are simultaneously met.

Where more permanent retention of the cover plate is required, e.g. in public or institutional settings, optionally holes 90 can be made in the cover plate 18 as indicated in dotted lines in Figure 11. The holes 90 correspond with the holes 70 and 38, so that the screws 20 can pass through both the cover plate 18 and clamping ring 16, to secure them both to the drain body 12. It is preferred that some of the screws (e.g. one opposed pair) pass through the clamping ring but not the cover plate, whilst others (e.g. another opposed pair) pass through both components, whereby the clamping ring remains secured in position when the cover screws are extracted and the cover plate 18 removed. The screw heads may be countersunk into the cover plate and/or bosses 68a-d, as applicable. Additionally or alternatively, the screw heads may stand proud of the bosses 68a-d and be accommodated in relieved areas formed in the undersides of the spacer feet 74a-d. The cover plate holes 90 and extended screws may be used with or without the pips and recesses 82a,b, 84a,b.

Rather than being provided on a clamping ring 16 as shown, the bosses 68a-d may be provided around a central opening in a tile adaptor or bezel. The cover plate may thereby be supported over the central opening in the manner described above for the clamping ring.

Where screws are used to secure the bezel in place, they may be received in screw threaded holes formed in some (e.g. an opposed pair) or all of the bosses.

Claims (14)

1. CLAIMS1. As an assembly or as a kit of components: i) a drain cover plate (18) or grating and ii) a component (16) to which the cover plate or grating is mounted in use, a boss (68a-d) exposed to drainage fluid flow in use spacing the cover plate or grating from the component to define a drainage flow inlet (88a-d); an upper surface portion of the cover plate or grating meeting a surface of the component to provide a substantially step-free junction.
2. 2. The assembly or kit (10) of claim 1, in which a releasable fastener extends through the boss.
3. 3. The assembly or kit of any (10) of claim 2 in which the releasable fastener (20) passes through both the cover plate (18) or grating and the component (16).
4. 4. The assembly or kit (10) of claim 3 in which a plurality of the bosses (68a-d) and the releasable fasteners (20) are provided, at least one of these releasable fasteners extending through the cover plate (18) or grating, and at least another one of which does not.
5. 5. The assembly or kit (10) of any preceding claim, comprising a plurality of the bosses (68a-d).
6. 6. The assembly or kit (10) of claim 5 in which the bosses form the sole mounting means for the cover plate (18) or grating on the component (16).
7. 7. The assembly or kit (10) of any of claims 1 or 2 in which the cover plate (18) or grating is retained on the component (16) by gravity or as a friction or interference fit.
8. 8. The assembly or kit (10) of claim 7 in which the friction or interference fit between the cover plate (18) or grating and the component (16) is provided by a cooperating recess (84a,b) and protuberance (82a,b).
9. 9. The assembly or kit (10) of any of claims 1-8 in which the component (16) comprises a clamping ring attachable to a drain fitting (12).
10. 10. The combination or kit (10) of any of claims 1-8 in which the component comprises a bezel or floor tile adaptor in which the grating or cover plate (18) is received.
11. 11. The combination or kit (10) of any of the preceding claims, in which the upper surface portion is provided on a laterally projecting part of the cover plate (18) or grating; whereby the laterally projecting part at least partially forms the end of a drainage inflow slot (88a-d) having opposed edges defined by the component (16) and cover plate/grating respectively.
12. 12. The combination or kit (10) of claim 10, in which the projecting part comprises a spacer foot (74a-d).
13. 13. The combination or kit (10) of claim 10, in which the boss (68a-d) is provided on the component (16) and cooperates with the spacer foot (74a-d).
14. 14. A component (16) and a grating or cover plate (18) mountable thereto, substantially as described with reference to or as shown in the drawings.