Drain assembly

Abstract

A drain assembly for water fittings for draining of water, comprising a drain housing with 5 an inlet connector for connecting to a water fitting and with an outlet and a valve exposed to a reset force, which opens if water flows from the inlet connector through the housing to the outlet, wherein the valve is provided with a valve sealing at a moveable valve closing body cooperating with a valve seat fixed to the housing; is characterized in that the moveable module comprising the valve sealing and the valve closing body has a surface 10 with a shape that has a smaller flow resistance than a plane surface.

Description

Technical Field The invention relates to a drain assembly for water fittings for draining of water, comprising (a) a drain housing with an inlet connector for connecting to a water fitting and with an outlet; (b) a valve exposed to a reset force, which opens if water flows from the inlet connector through the housing to the outlet, wherein the valve is provided with a valve sealing at a moveable valve closing body cooperating with a valve seat fixed to the housing. In a drinking and service water system there are fitting used to drain water to an outlet under certain conditions. Examples are system disconnectors which ensure the separation of a heating circuit from a drinking water source and prevent the backflow from the heating water circuit into the drinking water source. The drain valve is opened upon such backflow whereby the backflowing water is drained into a drain pipe. Another example is overpressure valves which open upon overpressure in the water system and guide water into the drain pipe. A drain assembly is provided for this purpose which normally consists of a system-side upper drain body and a drain funnel positioned there below. The drain body is a hollow body side openings which is open at the bottom and which is connected to a drain socket of the drinking- or service water system. Water to be drained flows in the drain body having an inner space where there is atmospheric pressure due to the side openings. The drain pipe is connected to the sewer channels. In order to avoid unpleasant smells normally a siphon is provided as an odour lock. Also, it must be avoided that rising sewage can exit through the drain funnel. There are, however, also assemblies without a siphon. Such assemblies are provided with an odour lock in the form of a valve similar to a backflow preventer. Prior Art DE 20 2005 002 415 UI und EP 2 895 659 Bl discloses such drain assemblies. The set of components comprises a backflow lock in the form of a closed component. The backflow lock comprises a valve opening in the drain direction and closing in the opposite direction. The lower drain funnel forms a receptacle configured to optionally have the backflow lock inserted therein. The valve prevents that odours from the sewage can rise through the upper drain body into the atmosphere. The upper drain body forms a connective portion with webs forming openings or cut-outs towards the atmosphere therebetween. The valve of the known drain assemblies comprise a spring pulling at a plunger. A disc-shaped valve plate having a plane valve sealing is fixed to the lower end of the plunger and is pulled upwards by the spring against a valve seat. Thereby, the valve is closed without the effect of further forces. If water flows out in a downward direction the valve opens as soon as the force by the water pressure exceeds the closing power of the spring. If much water flows out there is a risk of exiting splashing water exits or backwater. In this case water will exit through the side openings into the atmosphere. Disclosure of the invention It is an object of the invention to provide a drain assembly of the above mentioned kind where larger flows can be drained with the same diameters without exiting water. According to the invention, this object is achieved in that the moveable module comprising the valve sealing and the valve closing body has a surface with a shape that has a smaller flow resistance than a plane surface. In particular it can be provided that the valve sealing has a mushroom-shaped curved surface which at least partially surrounds the moveable valve closing body. A surface with a reduced flow resistance reduces the formation of turbulences in the range of the valve and the flow volume which can flow through without water exiting is larger at the same diameters. Particularly suitable is a valve sealing which is curved, an in particular which is mushroom-shaped curved. The cross section which is effective for the force of the water does not change. In the drain assembly a spring, such as a helical spring, may be provided exerting power on the valve closing body in a closing direction. The spring is preferably supported by a spring abutment fixed to the housing. In known assemblies the spring is positioned above the valve closing body and pulls it upwards into the valve seat. It has been shown, however, that a particularly good flow path is achieved, if the spring abutment is positioned below the valve closing body and the spring acts on the valve closing body from below. In such a modification the flow can be particularly advantageously guided, if the horizontal diameters of the moveable module comprising the valve sealing and the valve closing body correspond to the diameters of the spring abutment and guide the flow around the spring abutment if the valve is open. The spring abutment may have the shape of a pot with a circular upper edge and the valve sealing may form a circular rim abutting the upper edge of the spring abutment if the valve is fully open. No turbulences are formed inside the spring abutment. The module comprising the valve sealing and the valve closing body quasi forms a lid on the spring abutment. Preferably, it is provided that the spring abutment is held in the housing by webs which have a small flow resistance. For example, the webs may be positioned in the form of screw. Further modifications of the invention are subject matter of the subclaims. An embodiment is described below in greater detail with reference to the accompanying drawings. Definitions In this description and in the accompanying claims all terms have the meaning well known to the person skilled in the art which is defined in technical literature, norms and the relevant internet sites and publications, in particular of the lexical kind, such as www.wikipedia.de,www.wissen.de or of competitors, research institutes, universities and associations, such as, for example, Deutscher Verein des Gas- und Wasserfaches e.V. In particular, the terms used here have not the opposite meaning of what the person skilled in the art will derive from the above publications. Brief description of the drawings Fig. 1 is a perspective outside view of a drain assembly with an inserted valve and splash protection. Fig.2 is a longitudinal cross section of the drain assembly of Figure 1. Fig. 3 is a detail of Figure 2. Description of the embodiment In Figure 1 numeral 10 designates an upper drain body. At its upper end the drain body 10 is connected to a drain socket (not shown) by means of a fixing nut 12 and a clamping ring 14 (Fig.2). A lower drain funnel 16 is positioned on the same axis below the drain body 10. The drain funnel 16 is connected to a drain pipe (not shown) by means of a fixing nut 18 and a clamping ring 20 (Fig.2). The drain pipe is connected to the sewer channel. The drain body 10 and the drain funnel 16 are connected to each other by a bayonet fastening which can be released easily. Numeral 22 designates a backflow lock. Such backflow lock shall disconnect the connection to the sewer channel and thereby avoid bad odours if there is no siphon installed in the drain pipe. Also, it shall be avoided that sewage rises in the drain pipe and can exit through the drain assembly. The drain body 10 is provided with a socket-like upper section 24. A ring 26 is connected to the section 24 by webs 28. The webs 28 limit side openings 32. Such openings 32 ensure that the drain socket is directly connected to the atmosphere upon opening of the fitting side drain valve and atmosphere pressure is present. The webs 28 are arranged on two concentric rings wherein the webs on the inner ring are positioned just in the angular range of the openings of the outer ring and the webs on the outer ring are in the angular range of the openings of the inner ring. Thereby, splashing out of water is well avoided. The drain body 10 is provided with dripping noses 36 (Figure 2). Such dripping noses extend inwardly from the inner wall of the section 24 and extend with a tip in an axial direction towards the outlet side. Such dripping noses shall ensure a well-defined flowing out of the water from the drain socket into the drain funnel. The drain body 10 and the drain funnel 16 can be connected to each other by means of a screw- or bayonet connection. It is understood, that different further connections are possible, such as clip-connections and the like. The use of two components 10 and 16 enables the opening of the drain assembly and its use without a backflow lock 22, if applicable, such as, for example, if there is a siphon present already. If desired, such a backflow lock 22 can be installed at a later stage, if this is necessary. An annular ring shoulder 56 is provided in the upper range of the inner wall of the drain funnel 16. The backflow lock 22 in the form of a spring-biased valve is inserted in this range. The valve 22 comprises an annular valve seat 60 which is inserted into the drain funnel 16 together with a sealing 62. The valve seat 60 has a cross section with a curvature which is curved inward and downwards at its upper side, as can be well seen in Figures 2 and 3. Thereby, it is avoided that turbulences occur in the range of the valve seat 60. A valve closing body 30 with a valve sealing 34 cooperates with the valve seat 60 and forms the valve 22. The valve sealing 34 is curved mushroom-like and encloses the upper portion of the valve closing body 30. The valve closing body 30 is connected to a downwardly extending valve spindle 38. A weak helical spring 40 is arranged around the valve spindle 38. The upper end of the helical spring 40 pushes from below on the valve closing body 30. The lower end of the helical spring 40 is supported by a spring abutment 42 fixed to the housing. The spring abutment 42 is essentially pot-shaped with a rim 44 having an upwardly increasing rim 44. The spring abutment 42 is provided with a guiding cylinder 48 around the axis 46. The guiding cylinder 48 serves to guide the valve spindle 38. The spring abutment 42 is held in the drain funnel 16 forming a housing by means of webs 50. The webs 50 are arranged in the form of a spiral and also prevent the formation of flow turbulences in the outflowing water. The helical spring 40 pushes the valve closing body 34 with the valve sealing 30 upwards into the valve seat 60. Such closed position is shown in Figure 2. If water flows from above through the inlet 52 into the assembly, the force of the water pressure acts downwards against the spring power of the helical spring 40. If sufficiently much water flows the valve 22 opens. The fully open position is shown in Figure 3. The rim 58 which projects slightly inwardly in a horizontal direction has the same diameters as the upper edge 54 of the spring abutment 42. the module comprising the valve closing body 30 and the valve sealing 34, therefore, form a lid in the fully open state of the valve 22, which closes the upwardly directed opening of the spring abutment. This can be well recognized in Figure 3. In such a way the formation of turbulences in the spring abutment 42 is avoided. The assembly has few geometric features, in particular with strong flows, where turbulences can occur. Thereby, particularly much water can be drained with the same diameters, without having splash water exiting the openings 32 or having backwater with water exiting through the openings 32. The valve 22 is normally kept tight. Odors cannot exit through the drain pipe. Also, rising sewage will push the valve closed and cannot exit through the drain assembly. If water from the drinking or service water system flows out through the drain socket the water is collected above the valve 22. The valve closing body is pushed open by the weight of this water overcoming the spring power of the weak helical spring 40. Water can flow out. The exemplary embodiments explained above serve to illustrate the invention claimed in the claims. Features that are disclosed together with other features can generally also be used alone or in combination with other features that are explicitly or implicitly disclosed in the text or drawings in the exemplary embodiments. Dimensions and sizes are given as examples only. Suitable ranges can be derived by the knowledge of the person skilled in the art and therefore do not need to be explained in more detail here. The disclosure of a specific embodiment of a feature does not mean that the invention should be limited to this specific embodiment. Rather, such a feature can be implemented using a variety of other configurations that are familiar to those skilled in the art. The invention can, therefore, be embodied not only in the form of the embodiments explained, but also in all embodiments which are covered by the scope of the appended claims. 5 The terms "top”, "bottom", "right" and "left" exclusively refer to the attached drawings. It is understood that claimed devices also can adopt a different orientation. The term “including” and the term “comprising” mean that further components not mentioned may be provided. The terms “essentially” and “predominantly” include all characteristics that have a majority of a property or content, i.e. more than all the other components or 10 properties of the feature mentioned, i.e. in the case of two components, for example, more than 50%.

Claims

1. Drain assembly for water fittings for draining of water, comprising(a) a drain housing with an inlet connector for connecting to a water fitting and with an outlet;(b) a valve exposed to a reset force, which opens if water flows from the inlet connector through the housing to the outlet, wherein the valve is provided with a valve sealing at a moveable valve closing body cooperating with a valve seat fixed to the housing;characterized in that(c) the moveable module comprising the valve sealing and the valve closing body has a surface with a shape that has a smaller flow resistance than a plane surface.

2. Drain assembly according to claim 1, characterized in that the valve sealing has a mushroom-shaped curved surface which at least partially surrounds the moveable valve closing body.

3. Drain assembly according to any of the preceding claims, characterized in that a spring is provided exerting power on the valve closing body in a closing direction.

4. Drain assembly according to claim 3, characterized in that the spring is supported by a spring abutment fixed to the housing.

5. Drain assembly according to claim 4, characterized in that the spring abutment is positioned below the valve closing body and the spring acts on the valve closing body from below.

6. Drain assembly according to claim 5, characterized in that the horizontal diameters of the moveable module comprising the valve sealing and the valve closing body correspond to the diameters of the spring abutment and guide the flow around the spring abutment if the valve is open.

7. Drain assembly according to claim 6, characterized in that the spring abutment hasthe shape of a pot with a circular upper edge and the valve sealing forms a circular rim abutting the upper edge of the spring abutment if the valve is fully open.

58. Drain assembly according to any of claims 4 to 7, characterized in that the spring abutment is held in the housing by webs which have a small flow resistance.

9. Drain assembly according to claim 8, characterized in that the webs are positioned 10 in the form of screw.10

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