WO2010103370A1 - Water drain assembly, in particular for siphonic roof drainage systems - Google Patents

Abstract

A water drain assembly (1), in particular for siphonic roof drainage systems, essentially extends along an axis (A) and comprises a base body (2), having a water inlet opening (10) and an anti-vortex cover (4), arranged to protect the opening (10) to convey water into the body (2) and comprising a top disk (40) and a plurality of radial blades (41) that project from a bottom face (42) of the disk (40); the drain assembly comprises a first group of blades (41a) and a second group of blades (41b), circumf erentially alternating, the blades (41b) of the second group having a variable width along the blade and a different shape from the blades (41a) of the first group.

Description

WATER DRAIN ASSEMBLY, IN PARTICULAR FOR SIPHONIC ROOF DRAINAGE SYSTEMS

TECHNICAL FIELD The present invention relates to a water drain assembly, in particular for siphonic roof drainage systems .

BACKGROUND ART

In general, a building rainwater evacuation system consists of collection drain assemblies installed on the roof and of a network of pipes formed by columns and headers which convey the water into the main drain conduit outside the building.

Rainwater may be drained from broad roof surfaces by means of two different systems: traditional systems (also known as gravity systems) ; siphonic systems (or siphon effect systems) .

Operation of traditional drain systems is based on the gravity effect acting on the water which flows in pipes working at atmospheric pressure . The rainwater which is collected on the surface of the roof falls into the collection drain assemblies reaching the header which is the lowest point of the drainage network. The amount of water which is accumulated on the roof and therefore in the drain assembly generates the drainage force which pushes the water itself into the network. In traditional drain assemblies, consisting of a hole possibly protected by a grid, the falling water generates a vortex which tends to also convey air. The presence of air reduces the efficiency of the conduit because it is not completely filled by drain water,- only 1/3 of the section is generally occupied by water, while the remaining 2/3 of the section is occupied by air.

On the contrary, siphonic drain systems operate at full capacity, thus with a filling ratio of 100%, by generating a vacuum which aspirates the rainwater and drains it at high speed.

While the drain assemblies used in traditional systems are characterized by a collection funnel and by a possible protective grid, the drain assemblies used in the siphonic system are provided with an "anti-vortex" insert, which under full capacity conditions prevents the air from entering and fully filling the tubes. The "anti-vortex" insert is the key element of the siphonic drain assembly because it prevents the formation of the vortex which conveys major amounts of air into the tube, which is a typical phenomenon of gravity drain assemblies .

If the intensity of the rainfall is low and the rainwater which accumulates on the surface of the roof is not sufficient to fully immerse the "anti-vortex" insert, the system works as a traditional gravity system because the introduction of air is not prevented. If the intensity reaches full-capacity levels (defined during the designing step) and the water fully covers the "anti-vortex" insert, the introduction of air is prevented and the water which flows into the conduit generates vacuums which tend to considerably accelerate the drain flow. The advantages of the siphonic drain systems as compared to the traditional gravity systems are known; however, the currently known siphonic drain systems, in turn, are also suited to be further improved, especially in terms of efficiency, simplicity, dimensions and construction and installation cost-effectiveness. DISCLOSURE OF INVENTION

It is an object of the present invention to provide a water drain assembly, in particular for siphonic drainage systems of building roofs, which is either equally or more efficient than the known solutions, simple and cost-effective to be constructed and installed, and small in size.

The present invention thus relates to a water drain assembly, in particular for siphonic roof drainage systems, as defined in essential terms in appended claim 1, the additional features of which are disclosed in the dependent claims.

The drain assembly in accordance with the invention is simple and cost-effective to be implemented and installed, small in size and fully effective; in particular, the drain assembly of the invention ensures that the drainage system in which it is inserted always effectively works with full section (i.e. with the conduits completely filled with water) , under design rain conditions, being capable of avoiding the introduction of air in the pipes through the drain assembly, and either limiting or entirely preventing the formation of air bubbles in the water flow. BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will be apparent from the following description of a non- limitative embodiment thereof, with reference to the figures in the accompanying drawings, in which: figure 1 is an exploded diagrammatic view of a water drain assembly, in particular for siphonic drainage systems of building roofs, in accordance with the invention; figure 2 is a section view of the assembled drain assembly in figure 1; figure 3 is a perspective view of a component of the drain assembly in figure 1; - figure 4 is a perspective view of a further component of the drain assembly in figure 1; figures 5 and 6 are bottom plan and diametrical-section views, respectively, of a further component of the drain assembly in figure 1. BEST MODE FOR CARRYING OUT THE INVENTION

In figures 1 and 2, numeral 1 indicates a water drain assembly, in particular belonging to a siphonic drainage system of building roofs; the system as a whole is not shown but comprises, as known, a plurality of drain assemblies generally installed on the roof of the building and pipes and headers of various sizes and shapes, which connect each drain assembly to' a main drain conduit outside the building.

The drain assembly 1 is intended to be installed on a roof element, e.g. a roof, a gutter, etc. (not shown) .

The drain assembly 1 essentially extends along an axis A (which is substantially vertical in use) , and comprises a base body 2, a coupling flange 3, an anti- vortex cover 4, a top grid 5 and a connection sleeve 6.

With further reference to figure 3, body 2 essentially is a generally funnel-shaped, tubular body extending along axis A; in particular, body 2 comprises a bottom tubular portion 8, e.g. substantially cylindrical, and a top coupling portion 9 substantially annular and flared upwards, which projects at the top and radially diverges from the tubular portion 8.

The tubular portion 8 has a top, substantially circular water inlet opening 10 and an outer side surface 11 provided with one or more (two, in the preferred embodiment illustrated) circumferential seats

12, which accommodate respective sealing rings 13, e.g. o-ring type,- surface 11 further has a circumferential groove 14, preferably placed over the seats 12 and close to the coupling portion 9, which accommodates a locking element 15 (described in detail below) .

The coupling portion 9 is funnel-shaped and converges towards axis A and towards the opening 10 of the tubular portion 8; in particular, portion 9 has an top annular surface 18 inclined radially inwards with respect to axis A; the top surface 18 has a radially inner, preferably convex, annular edge 19, and a radially outer, preferably concave, annular edge 20. The radially inner edge 19 is connected to the opening 10 of the tubular portion 8, while a substantially flat, radially outer, annular crown 21 projects from the radially outer edge 20 (thus substantially orthogonal to axis A) ; crown 21 is provided with through holes 22 intended to secure the body 2 on a roof element (e.g. roof or gutter) by means of countersunk head screws (not shown), or other fastening members, for example. Portion 9 is further provided with assembly seats 23, e.g. internally threaded, for inserting respective assembly members 24, e.g. screws; the seats 23 are blind-bottomed (i.e. are not through) , so as to ensure a complete sealing against water leakage. For example, the seats 23 are formed within respective collars 25, which vertically project from the top surface 18.

The coupling portion 9 defines a seat 26 circumferentially delimited by the crown 21.

According to a preferred embodiment, but not necessarily, body 2 is made of metal material, in particular aluminium or aluminium alloy (preferably painted) .

With further reference to figure 4, the coupling flange 3 is used to install the drain assembly 1 on a roof element and allows the installation on roof elements of various type, e.g. coated with different materials; in particular, flange *3 is inserted into seat 26 and is shaped so as to be coupled to the coupling portion 9 of body 2 by clamping a waterproofing sheet

(not shown) , e.g. a plastic sheath , bitumen, etc. or a metal sheet, of the roof element between flange 3 and portion 9. Flange 3 is ring-shaped about a central opening and axis A, and has a substantially annular bottom face 31, facing the portion 9 and shaped so as to rest on the top surface 18 of portion 9, e.g. reproducing the shape thereof, with the interposition of the waterproofing sheet, which thus remains interposed and clamped between flange 3 and portion 9. The coupling profile between flange 3 and portion 9 is such as not to excessively bend, cut, strain or damage the waterproofing sheet.

Furthermore, flange 3 has a substantially annular top face 32, opposite to the bottom face 31, provided with a plurality of radial ribs 33 that project from the face 32 and which are radially arranged and angularly spaced apart from one another on face 32. The ribs 33 have respective substantially flat, top resting surfaces 34, substantially flushed with a top surface 35 of crown 21.

Flange 3 is provided with through holes 36, e.g. formed in some of the ribs 33, aligned with the seats 23 of portion 9 and through which the assembly members 24 are arranged .

Flange 3 like body 2 is preferably, but not necessarily, made 'of metal material, in particular aluminium or aluminium alloy (preferably painted) .

With reference to figures 5 and 6, the anti-vortex cover 4 is shaped so as to prevent the formation of vortexes in the water entering the drain assembly 1 and the introduction of air into the drain assembly 1. Cover 4 comprises a top disk 40 and a plurality of blades 41 which project from a bottom face 42 of the disk 40, and which convey the water into the body 2 thus avoiding the vortexes from being formed.

Cover 4 is also preferably, but not necessarily, made of metal material, and preferably of aluminium or painted aluminium alloy.

Each blade 41 radially extends on the bottom face 42 of the disk 40 between a radially outer end 43, facing a peripheral edge 44 of the disk 40 (i.e. of the cover 4), and a radially inner end 45, facing the opening 10; end 43 is radially spaced from the peripheral edge 44, i.e. each blade 41 is separated from the peripheral edge 44 and ends at a given radial distance therefrom; this contributes to improving the efficiency of the drain assembly 1, particularly avoiding the formation of waves and disturbances; each blade 41 preferably projects beyond the opening 10. The blades 41 are also radially spaced from axis A, i.e. from a geometric centre of disk 40 (the blades 41 are not centrally joined but instead end at a given radial distance from axis A) .

The blades 41 are radially arranged about axis A and angularly spaced from one another.

The blades 41 are aligned with respective ribs 33 of flange 3 and each rib 33 supports a blade 41; in particular, each blade 41 has a bottom resting surface 46, which rests on the top resting surface 34 of a respective rib 33; each resting surface 46 preferably has the same shape as the resting surface 34 on which it rests and the shapes of ribs 33 are complementary to those of the blades 41 that they support (i.e. they substantially have the same fluid-dynamic profile) . The blades 41 are substantially L- shaped in longitudinal section, with the end 45 extending towards axis A and downwards.

Each blade 41 is then delimited by two lateral sides 47. In the preferred embodiment illustrated, cover 4 comprises a first group of blades 41a and a second group of blades 41b, having different shapes,- the blades 41a, 41b of the two groups are circumferentially alternating (in particular, each blade 41a follows a blade 41b and so on, i.e. each blade of a group is interposed between two blades of the other group) .

The blades 41a are delimited by respective pairs of sides 47, substantially parallel to each other, preferably substantially rectilinear; each blade 41a thus has a substantially constant width (i.e. the distance between the sides 47) along the blade (i.e. in the radial direction with respect to axis A) and a substantially rectangular cross-section.

The blades 41b are delimited by respective pairs of sides 47 converging towards axis A and towards the opening 10; each blade 41b thus has a variable width

(distance between the sides 47) along the blade (in the radial direction with respect to axis A) .

The ends 43, 45 of all blades 41 are preferably rounded .

The blades 41b are provided with respective holes 48 for the passage of assembly members 24 (screws) , which are therefore completely concealed within the blades 41b and do not interfere on the water flow. The holes 48 are obviously aligned with the holes 36 and the seats 23.

According to a variation, instead, the holes 48 for the assembly members 24 are formed through the disk 40 and are arranged outside the blades 41; the holes 48 are radially aligned with respective blades 41; each hole 48 is either arranged radially outside a blade 41, namely between the end 43 of such a blade 41 and the peripheral edge 44 of the disk 40, or radially inside the blade 41, i.e. between the end 45 of the blade 41 and the axis A (centre of the disk 40) .

The bottom face 42 of the disk 40 has a substantially flat central portion 49 (substantially- orthogonal to axis A) and an annular outer portion 50 converging towards axis A, i.e. at least partially inclined and/or curved downwards from the peripheral edge 44 towards axis A.

The peripheral edge 44 is profiled so as to promote the flow of water over/under the disk 40 and thus to reduce turbulences; in particular, the peripheral edge 44 is radially tapered (thinner) outwards. The peripheral edge 44 is delimited between two opposite surfaces 51 radially converging outwards, namely a top surface 51a and a bottom surface 51b.

With specific reference to figures 1 and 2 again, grid 5 is mainly intended to prevent the introduction of particularly large- sized debris (leafs, branches, crushed stone, gravel, etc.) into the drain assembly 1, but in accordance with the invention it has further additional features which contribute to improving the performances of the drain assembly 1. Grid 5 is substantially cage- shaped and is arranged above cover 4 to cover and close cover 4.

Grid 5 comprises a top plate 54 and a plurality of substantially vertical foils 55, which obliquely, radially project from the plate 54 towards the cover 4 and project beyond the peripheral edge 44 of cover 4, e.g. close to an end edge 56 of the crown 21. Grid 5 is thus radially arranged outside about cover 4.

Plate 54 is provided with through openings 57, e.g. radial slits, and with a tubular central hub 58 which accommodates a screw or other fastening member 59, which engages a seat 60 formed in the disk 40 to secure the grid 5 onto the cover 4. The foils 55 are angularly spaced from one another and are connected to one another by means of a structural stiffening ring 61 which is substantially arranged at the same height (determined along axis A) as the disk 40. Ring 61 is preferably radially arranged outside the peripheral edge 44 of disk 40 and substantially aligned therewith; ring 61 has a top face 52, facing towards the plate 54, and a bottom face 53, which are substantially flushed with the top surface 51a and the bottom surface 51b, respectively, of the peripheral edge 44, so as to extend surface 51a and/or surface 51b and thus radially extend the dimensions of cover 4. Ring 61, like edge 44, is advantageously profiled so as to promote the flow of water over and under the ring 61, and thus over and under the disk 40, thus reducing turbulences; in particular, ring 61 is tapered (thinner) radially outwards; faces 52, 53 are profiled so as to seamlessly join with the surfaces 51 of the disk 4.

The foils 55 have respective free bottom ends 62 which project so as to protrude below the ring 61.

The foils 55 have respective top portions 63, in particular arranged between ring 61 and plate 54, inclined with respect to axis A. Furthermore, grid 5 and cover 4 are preferably- connected by means of an angular coupling device 64 which prevents the rotation of the grid 5 with respect to the cover 4, e.g. when the water flow is remarkable. In the non- limiting example shown in figure 2, device 64 comprises at least one radial tooth 65 carried by the hub 58 and which engages a seat 66 formed in the disk 40.

In particular, hub 58 has a tubular central section and four radially outer appendixes arranged as a cross, which form respective teeth 65; disk 40 carries a cross- shaped ridge provided with seats 66 engaged by the teeth 65; thereby, hub 58 is used to vertically secure (along axis A) the grid 5 onto cover 4, by virtue of the screw 59, and to avoid grid 5 from rotating with respect to cover 4, by virtue of the coupling between tooth/teeth 65 and seat(s) 66.

The seats 60, 66 may be obviously formed on grid 5 instead of on cover 4, and in such a case the cover 4 would be provided with hub 58 and teeth 65.

The connection sleeve 6 is preferably made of plastic, e.g. polyethylene, and is used to connect the body 2, especially if this is made of metal, namely of aluminium, with tubes or fittings made of plastic, e.g. polyethylene .

Sleeve 6 is substantially tubular in shape, e.g. cylindrical, and is fitted about the tubular portion 8 of body 2. The sealing rings 13 ensure fluid-tightness between body 2 and sleeve 6; the seats 12 are appropriately spaced from one another to follow possible movements caused by the normal thermal expansions of the material. Sleeve 6 has an appropriately radial inner surface 67 profiled to avoid the risk of removing the sealing rings 13 when assembling the sleeve 6 on body 2.

The mechanical coupling between body 2 and sleeve 6 is ensured, for example, by the locking element 15, which is an elastic element carried by the body 2 and elastically deformable to selectively engage at least one coupling seat 68 formed in sleeve 6 (or vice versa) . In particular, the locking element 15 comprises a substantially C- shaped open ring 69, preferably made of metal (e.g. steel), having two opposite free ends 70 folded so as to define respective coupling heads 71. Ring 15 is accommodated in the groove 14 formed on body 2 and the ends 70 are inserted through an opening 72 (or respective openings) formed through a side wall 73 of sleeve 6 and defining the coupling seat 68, so that the coupling heads 71 prevent the removal of sleeve 6 from the body 2.

Sleeve 6 has an end part 74 having appropriate diameter and width to ensure the joining with polyethylene pipes or fittings by means of electric sleeves or butt welding.

Moreover, it is understood that further changes and variations may be made to the disclosure illustrated herein, without departing from the scope of the invention as defined in the appended claims.

Claims

1.- A water drain assembly (1), in particular for siphonic roof drainage systems, extending essentially along an axis (A) and comprising a base body (2) , having a water inlet opening (10) , and an anti-vortex cover

(4) , placed to protect the opening (10) and convey water into the body (2) and comprising a top disk (40) and a plurality of radial blades (41) that project from a bottom face (42) of the disk (40) ; the drain assembly being characterized by comprising a first set of blades

(41a) and a second set of blades (41b) circumferentially alternate, the blades (41b) of the second set having variable width along the blade and a shape different than the blades (41a) of the first set.

2.- A drain assembly according to claim 1, wherein each blade (41a) of the first set has a substantially uniform width along the blade.

3.- A drain assembly according to claim 1 or 2 , wherein the blades (41a) of the first set are delimited by respective pairs of sides (47) substantially parallel to each other,- while the blades (41b) of the second set are delimited by respective pairs of sides (47) convergent towards the axis (A) and towards the opening (10) .

4. - A drain assembly according to one of the preceding claims, wherein the cover (4) is provided with holes (48) that house respective fastening members (24), for example screws, for fastening the cover (4) to the body (2) ; and wherein the holes (48) are formed through at least some blades (41) , in particular in at least some blades (41b) of the second set, so that the fastening members (24) are housed inside said blades (41b) .

5.- A drain assembly according to one of the preceding claims, wherein the cover (4) is provided with holes (48) that house respective fastening members (24) , for example screws, for fastening the cover (4) to the body (2) ; and wherein the holes (48) are formed through the disk (40) outside the blades (41) , and each hole (48) is aligned radially to a blade (41) and positioned radially outer or radially inner with respect to the said blade (41), i.e. between a peripheral edge (44) of the disk (40) and a radially outer end (43) of the blade (41) facing said peripheral edge (44), or between a radially inner end (45) of the blade (41) and a geometric centre of the disk (40) .

6.- A drain assembly according to one of the preceding claims, wherein each blade (41) extends radially on the bottom face (42) of the disk (40) between a radially outer end (43) , facing a peripheral edge (44) of the disk (40), and a radially inner end

(45) , facing the opening (10) ; the radially outer end (43) of at least some blades (41) being spaced apart radially from the peripheral edge (44) .

7. - A drain assembly according to one of the preceding claims, comprising a grid (5) positioned above and around the cover (4) and comprising a plurality of substantially vertical foils (55) radially arranged around the axis (A) and a structural stiffening ring

(61) that connects the foils (55) ; the ring (61) being positioned substantially at the same height of and flush with the disk (40) of the cover (4) to define a radially outer extension of the disk (40) , so as to extend radially the dimension of the cover (4) .

8.- A drain assembly according to claim 7, wherein the grid (5) is fastened to the cover (4) by means of a screw or another fastening member (59) that engages a central tubular hub (58) carried by the grid (5) and a first seat (60) formed in the disk (40) of the cover (4), o vice versa; and by means of an angular locking device (64) that prevents rotation of the grid (5) with respect to the cover (4) and that comprises at least a radial tooth (65) carried by said hub (58) and that engages a second seat (66) formed in the disk (40) , o vice versa.

9.- A drain assembly according to one of the preceding claims, comprising a connection sleeve (6) , preferably made of plastic, for connecting the body (2) with plastic pipes or joints; the sleeve (6) being fitted around the body (2) and being axially fixed to the (2) by an elastic locking element (15) , that is housed in a circumferential groove (14) formed on the body (2) and has at least a coupling head (71) that engages an opening (72) formed through a lateral wall (73) of the sleeve (6) .

10.- A drain assembly according to claim 9, wherein the locking element (15) comprises an open ring, preferably made of metal, substantially C-shaped and having two opposite free ends (70) curved so as to define respective coupling heads (71) .

11.- A drain assembly according to one of the preceding claims, comprising a coupling flange (3) having a substantially annular bottom face (31) so shaped as to rest on a top surface (18) of the body (2), a waterproofing sheet being possibly interposed in use therebetween for clamping the waterproofing sheet between the flange (3) and the body (2); the flange (3) being provided with a plurality of radial ribs (33) that project from a top face (32) of the flange (3) and are aligned to and support respective blades (41) and have outlines complementary to those of the blades (41) supported, so as to define respective lower portions of the blades (41) and extend downwards the blades (41) .