EP3344826B1 - Water drainage system and production method - Google Patents

Description

Technical area

The invention relates to a device for draining water from flat roofs, balconies, terraces or other water-bearing surfaces, and a method for producing such a device.

Devices of this type are used to feed the water - in particular rainwater - accumulating on a flat roof, a terrace or a balcony into a drainage pipe. Such devices are also referred to as a gully. In principle, they comprise an inlet body which is usually designed in the shape of a funnel. In order to ensure a suitable seal of this inlet body with respect to the water-bearing surface, a connection film or sheet (for example a roof membrane made of flexible polyolefins (FPO) or a bitumen sheet) is tensioned between the inlet body and a press ring as a counterpart.

Basically, a roof surface can be drained in two ways: with the help of a gravity system or with a system with pressure flow. Roof drains with pressure flow are used to ensure safe and economical rain drainage from roof surfaces. When operating such a drainage system, the roof drain is fully filled. This creates a negative pressure in the drainage pipe, with the result that - in contrast to a gravity system - large amounts of rainwater can be drained off with comparatively small pipe dimensions.

State of the art

In the case of drainage devices of the type mentioned at the outset, the inlet bodies are made of metal (stainless steel) or plastic. In particular, standard thermoplastics are used for this purpose. Standard thermoplastics form one of the three groups into which thermoplastics are usually divided due to their temperature resistance, among other things: standard thermoplastics, engineering thermoplastics and high-performance thermoplastics. Standard thermoplastics are very versatile and are produced in large quantities. They include, for example, polyethylene or polyvinyl chloride. A material that is often used for the inlet body is polyethylene.

DE-U1-20 2007 000 013 discloses an inlet body with an inlet cup made of polyurethane, to which a pipe socket made of polyethylene is attached.

DE-C1-101 25 642 discloses a device for sealing a water inlet in flat roofs, balconies, terraces or other flat buildings, which consists of an inlet body with a collar edge which rests on the roof surface in the inserted state of the inlet body, and wherein an insert can be inserted into the inlet, which also has a Has collar edge, and wherein between the collar edge of the inlet body and insert a connecting foil is inserted, which is to be clamped for the sealing connection of a cover layer between them, wherein a ring for receiving tensioning elements is cast in the inlet body to accommodate sufficient tension, the ring is designed as an injection molded part with molded sleeves extending over the entire wall, so that a sleeve ring results in the wall. The ring can be formed from a hard plastic, preferably from a polyamide plastic. The sleeves can be designed for self-tapping screws.

From the patents U.S. 5,378,356 , U.S. 5,615,526 , DE 198 19 116 A1 and FR 1,501,272 as WO-A1-2010 / 103371 and EP 2 468 979 A1 other roof drains are known.

U.S. 4,487,690 WO A1 2010/103371 discloses an apparatus according to the preamble of claim 1 and a method according to the preamble of claim 11.

The invention

The object of the present invention is to develop a device for draining water in such a way that the overall height of the device can be reduced without adversely affecting the strength and rigidity properties of the device.

This object is achieved by a device for draining water according to claim 1.

Accordingly, the inlet body can be formed either from an engineering thermoplastic or from a thermoplastic composite material.

The term "engineering thermoplastics" includes in particular polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate (PC), polyoxymethylene (POM), polypropylene (PP) and acrylonitrile-butadiene-styrene (ABS). Engineering thermoplastics have better mechanical properties than standard thermoplastics such as polyethylene or polyvinyl chloride. Compared with devices with inlet bodies made of, for example, polyethylene, the device according to the invention can have a relatively low overall height due to the better strength characteristics of the engineering thermoplastic. This can be an advantage when installing the inlet body in the roof cladding.

A composite material is understood to be a material that generally consists of two main components (a bedding matrix and reinforcing elements such as particles or fibers). The mutual interaction of the two components gives such a material improved mechanical properties. The use of such a composite material therefore improves the mechanical properties of the inlet body compared to inlet bodies made of standard thermoplastics such as unreinforced polyethylene or polyvinyl chloride, so that the device according to the invention can again have a relatively low overall height due to the better strength characteristics. One of the engineering thermoplastics mentioned above, but also a standard thermoplastic such as polyethylene, for example, can be used as the basis or matrix for the composite material.

The device furthermore has a pressing element and means for bracing the pressing element against the inlet body, the inlet body and the pressing element being designed in such a way that a connection film can be clamped between the pressing element and the inlet body. The press element can be designed as a press ring or, in particular in the case of a roof drain for emergency drainage, as a retention ring.

In an advantageous embodiment, not only the inlet body but also the pressing element is made from an engineering thermoplastic or thermoplastic composite material. The pressing element is preferably formed from the same material as the inlet body.

The means for bracing the pressing element against the inlet body comprise at least one bolt or a screw. The bolt or screw is positively attached in the inlet body and extends through a through opening in the press element, the press element being different from that of the inlet body remote side of the pressing element is braced against the inlet body by means of a complementary element. If a threaded screw is used as a bolt or screw, the complementary element can be a threaded nut.

The means for bracing the press element against the inlet body can have at least one self-tapping threaded screw which is screwed directly into the inlet body so that it protrudes in the direction of the press ring. The strength properties of the material used for the inlet body, i.e. the engineering thermoplastic or thermoplastic composite material, ensure that the self-tapping threaded screws have a secure hold in the inlet body. - In many known roof gullies with inlet bodies made of PE, the press ring is braced against the inlet body by screwing metal countersunk screws directly into the inlet body. Over-tightening the screws by applying too high a tightening torque leads to the destruction of the thread because the PE used does not have the required strength. The required pretension for pressing the connection foil can then not be maintained, and the tightness of the system is endangered.

The device also has a collecting basket for leaves, gravel and the like, which can be placed on the inlet body. The collecting basket is fixed with respect to the inlet body by means of the bolt or the screw, which at the same time also serves to brace the pressing element against the inlet body. This reduces the number of components required to fix the leaf catcher.

As far as the specific configuration of the inlet body is concerned, an annular recess can be formed in a surface of the inlet body - namely that which points to the pressing element in the assembled state, which is designed as a support surface for a seal. The recess can be dimensioned in such a way that at least the seal is let into the inlet body in the assembled state. If, in addition, a difference in height between the surface of the inlet body and the contact surface formed by the annular recess is greater than the material thickness of the seal, the press element can also be at least partially embedded in the inlet body in the assembled state, so that the press element does not represent a significant flow obstacle.

The pressing element is preferably embedded in the inlet body up to half its height, better still up to two thirds of its height.

The material used for the inlet body and possibly the pressing element can be present as a composite or composite material. In particular, a composite or composite material based on an engineering thermoplastic can therefore also be used. In any case, the material can be fiber-reinforced, in particular glass fiber, basalt fiber, carbon fiber or aramid fiber reinforced. Instead of a fiber reinforcement, a fabric or braid can also be used to reinforce the plastic, wherein the fabric or braid can also be formed from glass fibers, basalt fibers, carbon fibers or aramid fibers, for example.

In a preferred embodiment, an engineering thermoplastic is used as the material for the inlet body and possibly the press element, which is a polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate (PC), polyoxymethylene (POM), polypropylene (PP ) or acrylonitrile butadiene styrene (ABS). However, all other engineering thermoplastics, in unreinforced design or as composite materials, are also suitable.

A well-suited material is thus, for example, polyamide, in particular fiber-reinforced, e.g. glass fiber-reinforced polyamide. Polyamides are among the most important engineering thermoplastics. They are tough materials with high strength and rigidity, excellent impact strength and good abrasion and wear resistance. Polyamides have a relatively low glass transition temperature and are therefore often reinforced with glass fibers. In addition to increasing strength and modulus of elasticity, this also significantly increases the long-term use temperature.

Another embodiment is carbon fiber reinforced polycarbonate.

The present invention finally also provides a method according to claim 11 for producing a device for draining water from flat roofs, balconies, terraces or other water-bearing surfaces, which device can have the features described above.

• der Einlaufkörper im Spritzgußverfahren hergestellt werden und der Bolzen oder die Schraube dabei im Fertigungswerkzeug für den Einlaufkörper platziert und mit dem thermoplastischen Material umspritzt werden, oder
• als Bolzen oder Schraube eine selbstschneidende Gewindeschraube verwendet werden, die - von der dem Pressring zugewandten Seite her - direkt in den Einlaufkörper eingeschraubt wird.

After at least one bolt or screw is provided as a means for bracing the pressing element against the inlet body, can

• the inlet body is manufactured by injection molding and the bolt or screw is placed in the production tool for the inlet body and encapsulated with the thermoplastic material, or
• A self-tapping threaded screw can be used as a bolt or screw, which - from the side facing the press ring - is screwed directly into the inlet body.

Finally, a collecting basket for a device for draining water from flat roofs, balconies, terraces or other water-bearing surfaces is disclosed, but not independently claimed, preferably a device of the type described above. The collecting basket can be placed on an inlet body of the device. It has a number of disc-shaped, vertically positioned lamellae which are evenly spaced in the circumferential direction and which open radially inward into a plate-shaped central part. A circumferential edge is formed on the radially outer edge of the plate-shaped central part, so that an inlet cross section of the collecting basket is reduced.

The lamellas can be connected to one another at their outer upper ends via a circumferential outer ring.

The middle part, the lamellae and, if necessary, the outer ring can be designed as a one-piece injection-molded part.

drawings

Figure 1

Figure 3 is a perspective view of a water drain according to the invention.

Figure 2

shows the water drainage in the view from below and in the side view.

Figure 3

shows the water drainage in plan view and in cross section.

Figure 4

is an exploded view of the water drain.

Figure 5

Figure 3 is an exploded cross-sectional view of the water drain.

Figure 6

shows a damming ring.

Figure 7

shows a slightly modified design of an inlet body.

Exemplary embodiment

the Figures 1 to 5 show different views of a roof drain 1 according to the invention.

The roof drain 1 is intended for installation in an opening provided for this purpose in a flat roof (not shown). It comprises an inlet body 2 with an annular or plate-shaped collar edge 20 which, in the assembled state of the roof drain 1, rests on one of the layers that form the roof structure. In the case of a warm roof, the collar edge 20 can in particular rest on insulation, in the case of a cold roof directly on the roof skin. A pipe socket 21 adjoins the collar edge 20 and penetrates the roof surface and forms an inlet opening 22 and an outlet opening 29 for discharging the collected water.

In order to seal the roof drain 1 against the roof structure, a connection film or sheet 7 (e.g. made of bitumen or FPO) and a seal 8 are braced against the inlet body 2 by means of a press ring 6. For this purpose, before the roof drain 1 is installed, the connecting foil 7 is cut out in the area of the inlet. The reference numeral 30 designates fastening holes on the outer circumference of the inlet body 2, the reference numeral 31 designates radially extending reinforcing webs on its underside.

In the present example, inlet body 2 and press ring 6 are made from glass fiber reinforced polyamide. The use of this engineering thermoplastic increases the strength and rigidity of these structural elements, and the structural height of the roof drain 1 can be reduced accordingly. Alternatively, another technical thermoplastic could also be used, also in unreinforced form, or a thermoplastic composite material, the basis of which does not necessarily have to be an engineering thermoplastic.

The press ring 6 made of the glass fiber reinforced polyamide has a greater material thickness (i.e. thickness, dimension in the vertical direction in the drawings) than conventional press rings, in particular than conventional metallic press rings. As a result, the press ring 6 has the necessary strength to brace the connection film 7 and the seal 8 between the press ring 6 and inlet body 2 and thus to produce a firm bond for pressing the seal 8. Inlet body 2 and press ring 6 can be screwed together with a tightening torque of> 20 Nm.

In the present example, the inlet body 2 and the press ring 6 are screwed together at eight positions evenly spaced around the circumference of the roof drain 1. The screw connection is realized by means of stud bolts 10 and associated nuts 11. The stud bolts 10 are self-tapping screws which have been pre-assembled in the factory from the side facing the press ring 6 in the inlet body 2 in order to facilitate the assembly of the roof drain 1 on site. The glass fiber reinforced polyamide plastic used for the inlet body 2 ensures that the screws are held particularly well. One possible design for the self-tapping screws are so-called double bolts.

Alternatively, stud bolts can also be placed directly in the production tool of the inlet body 2 and encapsulated with plastic, so that the production step of assembling the stud bolts in the inlet body 2 is omitted.

Alternatively, threaded pins can be embedded in the inlet body 2 in a manner known per se by means of ultrasound or heat transfer, or threaded inserts can be embedded in this way in the inlet body 2 and stud bolts can then be screwed into these thread inserts.

The stud bolts 10 protrude from the inlet body 2 in the direction of the press ring 6, and corresponding through-openings 62 are formed in the press ring 6, through which the stud bolts 10 are passed, in order to then turn from the side of the press ring 6 facing away from the inlet body 2 by means of nuts 11 to be braced against the inlet body 2.

If the roof drain is to be used for emergency drainage, a damming ring is provided as a press element instead of the press ring 6 shown here, by means of which the rainwater is initially dammed to a certain height. The emergency drain drains away rainwater only when this accumulation height is exceeded. Such Roof drains with retention rings for emergency drainage are known per se; they are installed at regular intervals on roof surfaces for the safe drainage of rain during heavy rain events and should only develop their effect during heavy rain events. According to the present invention, this damming ring can also be made from an engineering thermoplastic, here in particular a glass fiber reinforced polyamide, and preferably from the same material as the inlet body 2. Figure 6 shows an exemplary damming ring.

The roof drain also includes a collecting basket 4 for leaves, gravel and the like, which can be placed on the inlet body 2. In order to be able to fasten the leaf catcher 4 simply and in a user-friendly manner on the inlet body 2, two of the eight stud bolts 10 have a significantly greater length. These longer studs are marked 10 'in the drawings. By means of these stud bolts and associated wing nuts 13, the leaf catcher can be easily and securely fixed. This assembly method also ensures a simple revision option.

At the lower end of the inlet body 2 a pipe socket 21 is formed, which consequently also consists of the glass fiber reinforced plastic and to which a drainage pipe, e.g. a downpipe (not shown) is connected when the roof drain 1 is installed. In order to ensure easy installation of the downpipe, a pipe thread, for example a 2½ "thread, is formed on the free end of the pipe socket 21. The pipe thread can be formed directly in the injection molding tool on the inlet body 2. A connection socket can be screwed onto this pipe thread For example, it can consist of polyethylene (PE). Conventional welded connections for fastening the downpipe to the inlet body 2 are consequently dispensed with.

Above or upstream of the pipe thread, the pipe socket 21 has a threadless section. In this part of the pipe socket 21, a surface heating system can be attached in a suitable manner. By attaching a surface heating system, the safe operation of the roof drain 1, even in winter months, can be ensured. It prevents the roof inlet from freezing over in freezing rain or snow.

The inlet body 2 has an essentially annular shape in plan view. On the outer circumference of the inlet body 2 is an outer annular surface 23 (cf. Figure 5 ), which points to the leaf catcher 4 in the assembled state of the roof drain 1.

Radially within this first partial surface 23, the inlet body 2 has a likewise annular and horizontally running support surface 24 for the seal 8. The support surface 24 is recessed with respect to the outer annular surface 23. It runs between a radially outer shoulder 25 and a radially inner shoulder 26, the height of which in the present embodiment corresponds approximately to the material thickness of the seal, which can be approximately 3 mm, for example. In order to achieve the lowest possible structural height, the seal 8 is thus completely embedded in the inlet body. In an alternative embodiment, the seal 8 can only be partially embedded in the inlet body, but the shoulders 25, 26 should be at least as high as half the material thickness of the seal. From the outer ring surface 23, the surface of the inlet body 2 runs downwardly inclined towards the outer shoulder 25, whereby the height difference between the outer ring surface 23 and the bearing surface 24 for the seal is additionally increased. The height difference between the surface 23 of the inlet body and the bearing surface 24 formed by the annular recess is shown in FIG Figure 5 marked with "H". It is greater than the material thickness of the seal, so that in the assembled state the press ring 6 can also be at least partially embedded in the inlet body 2. The press ring would represent a flow obstacle if it were not sunk into the inlet body 2: the rainwater would be dammed up to the level of the press ring (in an exemplary embodiment about 10 mm) before it could be discharged, which in turn would mean that rainwater would be constantly flowing on the roof. By at least partially sinking the press ring, however, rainwater entering the roof drain can flow almost unhindered in the direction of the downpipe.

The transition between the radially inner shoulder 26 and the pipe socket 21 of the inlet body 2 is formed by an inclined surface 27, which is inclined downward in the direction of the pipe socket 21, and a rounded transition area 28. In the present embodiment, the inclined surface 27 is inclined at an angle of 17.5 ° with respect to the horizontal, and the rounded transition area 28 is formed with a radius of 10 mm.

The press ring 6 is essentially ring-shaped and has a through opening 61 in the central area which, when the roof drain is installed, is aligned with the outlet opening 29 of the inlet body 2 and through openings 71, 81 of the connection film 7 and the seal 8. Both on its outer circumference and on the circumference of the through opening 61, the press ring 6 has a rounded shape, in the present example with radii of 9 or 9.5 mm.

The inlet geometry of the inlet body 2 and the press ring 6 are therefore designed to be flow-optimized in order to increase the hydraulic performance of the roof drain 1.

The geometry of the leaf catcher 4 is also flow-optimized.

The leaf catcher 4 is formed from a number of disc-shaped, vertically positioned lamellae 42 which are uniformly spaced in the circumferential direction and which open radially inward into a plate-shaped central part 46. In order to increase the stability of the vertical lamellae 42, all the lamellae 42 are connected to one another at the outer upper edge via a circumferential outer ring 44. Central part 46, lamellae 42 and outer ring 44 are designed as a one-piece injection-molded part in the present embodiment. The rainwater can flow into the roof drain 1 through the openings between each two adjacent slats 42. The openings correspond to the specifications of DIN EN 1253-2: 2015-03, Table 1 (min. 4 mm, max. 15 mm). Horizontal struts which impede flow in the area of the rainwater inlet are dispensed with, so that the rainwater can flow freely into the roof drain 1.

The plate-shaped middle part 46 forms a downwardly protruding thickening 47 in the central area. This reduces the volume within the leaf catcher 4, whereby the roof drain 1 is filled more quickly and can build up the necessary negative pressure to start the drainage process. Furthermore, through the central thickening 47, the rainwater flowing into the roof drain 1 is deflected in the direction of the outlet opening 29 in the inlet body 2 and thus the downpipe connected there.

At the radially outer edge of the plate-shaped middle part 46, the plate-shaped middle part 46 is adjoined by a circumferential edge 48 that protrudes downward with respect to the plate-shaped middle part 46. This narrows the inlet cross-section, increases the flow velocity at the point and increases the drainage capacity of the roof drain.

Figure 7 shows a slightly modified configuration of an inlet body 2 '. It differs from the one described above and in the Figures 1 to 5 The inlet body 2 shown on the one hand in the positioning of the four fastening holes 30 ', which - unlike the inlet body 2 - are angularly offset with respect to the eight stud bolts 10: When viewed in the circumferential direction of the inlet body 2, each fastening hole 30' is arranged between two stud bolts 10. On the other hand, the inlet body 2 ′ differs from the inlet body 2 in that it is provided with a circumferential collar 32 on its outer circumference. The radially extending reinforcement webs 31 'extend radially up to the collar 32, and their dimension corresponds to the dimension of the collar 32 in the direction of a thickness of the inlet body 2' (in the vertical direction in the drawing).

Claims (13)

1. Device (1) for draining water from flat roofs, balconies, terraces or other water-bearing surfaces,

   with an inlet body (2) which forms an inlet opening (22) and an outlet opening (29) for the water which is to be drained,

   with a catcher basket (4) for leaves, gravel and the like which can be placed on the inlet body (2),

   with a press element (6), and

   with means for clamping the press element (6) against the inlet body (2) which comprise at least one bolt or one screw (10, 10'),

   wherein the inlet body (2) and press element (6) are designed in such a way that a sealing membrane or flashing (7) can be clamped between press element (6) and inlet body (2), and

   wherein the bolt or the screw (10, 10') is fixed in the inlet body (2) in a form-locking manner and extends through a through-opening (62) in the press element (6),

   wherein the inlet body (2) is formed from a technical thermoplastic or from a thermoplastic composite material, characterised in that

   the press element (6) is clamped against the inlet body (2) from the side of the press element (6) facing away from the the inlet body (2) by means of an element (11) complementary to the at least one bolt or the at least one screw (10, 10'), and

   the catcher basket (4) is fixed relative to the inlet body (2) by means of the bolt or the screw (10, 10') which also serves to clamp the press element (6) against the inlet body (2).
2. Device (1) according to claim 1, wherein the press element (6) is likewise formed from a technical thermoplastic or thermoplastic composite material, and preferably from the same material as the inlet body (2).
3. Device (1) according to claim 1 or 2, wherein the bolt or the screw (10, 10') is a self-tapping threaded screw.
4. Device (1) according to one of the preceding claims, wherein an annular depression is formed in a surface (23) of the inlet body (2) which is designed as a support surface (24) for a seal (8) so that the seal (8) is at least partially recessed in the inlet body (2) when installed.
5. Device (1) according to claim 4, wherein a height difference (H) between the surface (23) of the inlet body (2) and the support surface formed by the annular depression (24) is greater than a material thickness of the seal (8).
6. Device (1) according to one of the preceding claims, wherein the material of the inlet body (2) and optionally of the press element (6) is a composite or compound material.
7. Device (1) according to one of the preceding claims, wherein the material of the inlet body (2) and optionally of the press element (6) is fibre-reinforced, in particular glass fibre-, basalt fibre-, carbon fibre- or aramid fibre-reinforced.
8. Device (1) according to one of the preceding claims, wherein the material of the inlet body (2) and optionally of the press element (6) is reinforced by means of a woven fabric or mesh which is formed, for example, of glass fibres, basalt fibres, carbon fibres or aramid fibres.
9. Device (1) according to one of the preceding claims, wherein a technical thermoplastic that is a polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate (PC), polyoxymethylene (POM), polypropylene (PP) or acrylonitrile butadiene styrene (ABS) is used as the material of the inlet body (2) and optionally of the press element (6).
10. Device (1) according to one of the preceding claims, wherein the inlet body (2) is designed with a pipe socket (21) at the free end of which a pipe thread is formed for a threaded connection with a connecting pipe.
11. Method for producing a device (1) for draining water from flat roofs, balconies, terraces or other water-bearing surfaces,

    in which method an inlet body (2) is provided which comprises an inlet opening (22) for receiving the water which is to be drained and an outlet opening (29) for discharging the water,

    wherein a catcher basket (4) for leaves, gravel and the like is also provided which is placed on the inlet body (2),

    wherein a press element (6) and means for clamping the press element (6) against the inlet body (2) are also provided which comprise at least one bolt or at least one screw (10, 10'), wherein the at least one bolt or the at least one screw (10, 10') is fixed in the inlet body (2) in a form-locking manner and extends through a through-opening (62) in the press element (6), and

    wherein the inlet body (2) and press element (6) are designed in such a way that a sealing membrane or flashing (7) can be clamped between press element (6) and inlet body (2),

    wherein the inlet body (2) is formed from a technical thermoplastic or from a thermoplastic composite material, characterised in that the press element (6) is clamped against the inlet body (2) from the side of the press element (6) facing away from the inlet body (2) by means of an element (11) complementary to the at least one bolt or the at least one screw (10, 10'), and

    the catcher basket (4) is fixed relative to the inlet body (2) by means of the bolt or the screw (10, 10') which also serves to clamp the press element (6) against the inlet body (2).
12. Method according to claim 11, wherein

    - the inlet body (2) is produced by injection molding and the bolt or the screw (10, 10') is thereby placed in the production mould for the inlet body (2) and is overmoulded with the thermoplastic material, or

    - a self-tapping threaded screw that is screwed directly into the inlet body (2) is used as a bolt or screw.
13. Method according to one of the claims 11 and 12, wherein the inlet body (2) is designed with a pipe socket (21) at the free end of which a pipe thread for a threaded connection with a connecting pipe is moulded, preferably directly in the injection mould for the inlet body (2).

Images