AU2018280778A1

AU2018280778A1 - Lavatory

Info

Publication number: AU2018280778A1
Application number: AU2018280778A
Authority: AU
Inventors: Rolf Weiss; Maurus Zwicker
Original assignee: Geberit International AG
Current assignee: Geberit International AG
Priority date: 2017-06-09
Filing date: 2018-06-08
Publication date: 2020-01-02
Anticipated expiration: 2038-06-08
Also published as: PT3412840T; ES2837250T3; CN110719982A; DK3412840T3; WO2018224632A1; PL3412840T3; DE202017005242U1; JP2020522629A; EP3412840A1; ZA201907555B; SI3412840T1; AU2018280778B2; EP3412840B1; IL270805A; CN110719982B; JP6981594B2

Abstract

The invention relates to a lavatory that comprises a lavatory bowl (1) having a specific inner bowl shape designed for a rotating flow of flush water, wherein a second flow path section (7) provided in addition to the prior art, or a separate second flow path (7), results in an improvement in terms of avoiding splash-over, and thus particularly results in simplifications in terms of avoiding undercuts in the inner bowl shape.

Description

Water closet

The present invention relates to a water closet, briefly “WC” in the following.

WCs having a WC bowl, a flushing water supply therefor and a drain for the wastewater being typically connected via a siphon are commonly used and known. Recently, further technical development has focused on additional features such as shower arrangements, odour extractors and the like.

WCs comprise a WC body which has in particular a hollow form being open to the top, namely the WC bowl, which is typically, although not necessarily, made of a ceramic material. Further technical means can be provided in the ceramic part of the WC body or also in attached parts or behind/under covers on the ceramic body.

Above or at an upper inner rim of the WC bowl, a conventional WC body has what is known as a flush rim, namely a circumferential flushing water channel having entry openings pointing downwards for the influx of the flushing water into the WC bowl; as regards the supply of the flushing water to the bowl, the flush rim functions similarly to a ring-shaped shower. Furthermore, WCs having a rotating flushing water flow in the WC bowl are known, wherein a vortical flow in the bowl prior to the exit of the flushing water through the siphon and the wastewater drain is caused by a largely tangential entry of the flushing water into the bowl.

Regarding the prior art, reference is made to EP patent 2 604 761 B1 of the same proprietor, which concerns an asymmetric WC bowl inner shape generating and assisting a rotating movement of the flushing water therein. This allows good flushing results to be achieved with comparatively small quantities of flushing water. It has also become apparent that this WC bowl works particularly quietly.

GBR-T 202869WO

The object of the present invention is to provide a further improved WC bowl. This problem is solved by claim 1, which will be explained in more detail below along with various preferred embodiments. Preferred embodiments of the device according to the invention and its use are indicated in the dependent claims. The features contained therein and the disclosure of the following description are in principle to be understood in respect of both invention categories without any explicit distinction always being made between them.

In order to be able to provide a comprehensible description of the inner shape of the WC bowl and the flushing water flow, defined axes of coordinates in the top view looking onto the bowl opening are assumed. A bowl opening shape of a circular or oval (in the sense of a longitudinally distorted round) form is assumed. The bowl opening shape typically clearly resembles the approximate inner shape of the bowl at least in its upper region. For that reason, it makes sense to define as the longitudinal axis the longest inner dimension through the bowl opening shape and as the transverse axis a perpendicular bisector. With typical WC bowls, this means that when in a typical seated position on the WC the user looks in the direction of the longitudinal axis and his shoulders proceed in the direction of the transverse axis. In the case of wall mounting, the longitudinal axis is then typically perpendicular to the wall and the transverse axis proceeds parallel to it.

Two important core thoughts have crystallised out of numerous experiments and analyses of the inventors. Firstly, although the WC bowl described in the patent just cited, with the markedly rotating flushing water flow, is very advantageous in respect of the flushing results, noise and water-saving potential, something which other manufacturers are also claiming for other WC bowls with a rotating flushing water flow. In contrast to conventional WC bowls with a classic flush rim, in other words a very distributed and shower-like flush, with rotating flushing water flows there is generally a danger that if the speed is too high the flushing water can spill over the upper edge of the bowl. In addition to the specific form of the bowl inner shape and the resulting flow pattern, this danger is also dependent on how much the upper rim of the inner shape of the WC bowl overhangs inwards. For exam

GBR-T 202869WO pie, Figs. 5 and 6 of the cited patent show that despite avoiding a classic flush rim, the bowl shape there overhangs inwards at this upper rim.

Secondly, such overhanging shapes form undercuts that are disadvantageous to production. By contrast, a lesser overhang or even the avoidance of undercuts is advantageous to production. This, however, in turn presents an increased danger of the spillover described.

It has further become apparent that, as a result of its kinetic energy, the flushing water flow introduced approximately tangentially to the bowl inner shape can, for a limited section downstream of the entry opening, be guided relatively well on a steep wall of the bowl inner shape, in particular at a relatively markedly concave point such as at the ends of an oval bowl shape that are connected by the longitudinal axis. Then, however, it increasingly tends to slope down under the influence of gravity. If such a sloping portion of the flow then meets the less inclined flow path described in the cited patent, a quasi building up flow shape can result. Expressed another way, such a sloping portion of the flow is almost reflected upwards again. It is especially in such situations that there is a particular risk of splashing out, especially if the upper edge of the bowl inner shape is not formed with a clear undercut.

It should be noted briefly in this regard that a flow path within the meaning of this description is understood to be a path-like face proceeding in the inner wall of the WC bowl, which face is limited outwards, in other words in the transition to the wall leading further upwards, by a concave edge, and is limited inwards, in other words in the transition to the wall leading further downwards and in the direction of the outflow, by a convex edge. An edge is determined by a particularly sharp curvature in a vertical section, thus in mathematical terms by an extreme value of the curvature. The cited EP 2 604 761 B1 and the following exemplary embodiment give a clearer idea.

GBR-T 202869WO

Such a flow path serves to guide or at least assist a certain water flow. As a result of the essentially tangential entry into the interior of the bowl, the water circulates and is held by the centrifugal forces at the bowl inner wall, but is simultaneously pulled downwards (more or less obliquely) by gravity, so that corresponding flow-guiding properties can be achieved by variations in the shape of the bowl inner wall.

The tangential direction of entry of the flushing water is predetermined by the form of the flushing water entry, in other words by the entry opening and the pipe section connected to it upstream for the flushing water. Such a tangential embodiment of the flushing water entry is in itself already realised in a variety of forms in the prior art and usually serves the purpose of a rotating flushing water flow in the WC bowl.

According to the invention, a second or an extension of the known flow path is provided in addition to a flow path known from EP 2 604 761B1. This second or extended flow path is intended to prevent a direction of flow pointing too strongly downwards of at least a portion of the flushing water and hence reduce or prevent the “building up” described above. If a portion of the flow is “held” at a certain height by the flow path, this causes the complete flow to drop less sharply there or downstream thereof, or the flow portion proceeding on and above the second or extended flow path to meet a flow portion proceeding further below.

Starting from the above definition of the longitudinal and transverse axes, the rotational movement of the flow in the bowl and the position of certain properties of the bowl inner shape are to be described with an azimuthal angle that manifests itself from a certain position in the bowl (top view) to the point of intersection of the axes, namely as the angle to the longitudinal axis. For example, therefore, that point of the bowl opening that is closest to the wall is on the longitudinal axis and hence at an azimuthal angle of 0° or 180°. From this there is then a lateral region in the area around 90° or 270°.

GBR-T 202869WO

According to the invention, the flushing water is to be directed through the entry opening onto a concave (as seen in the top view) curvature region of the inner wall of the WC bowl, for which the entry opening is at an azimuthal angle of between 80° and 180°. The entry opening is preferably at azimuthal angles of less than 170°, 160°, 150° or even 140°, and likewise preferably at an azimuthal angle of at least 90°, whereby the flushing water flows out in the direction of greater azimuthal angles. In other words, the entry opening preferably lies in a quadrant upstream of a particularly concave curvature of the bowl opening and aims at this particularly concave point. The background is that, with a particularly sharp concave curvature, the centrifugal forces having a stabilising effect in combination with a certain residual slope of the bowl inner shape (as seen in a vertical section) initially guide the flushing water flow through this curvature in a relatively stable manner, whereby it is assumed that the substantial part of the bowl inner shape expands somewhat from bottom to top and there is a corresponding slope. As mentioned above, there are typically exceptions at the top on the bowl rim in the form of undercuts.

The aforementioned region, which is normally curved in a particularly sharply concave manner, of the WC bowl can be at approximately 180°, hence at the end point of the longitudinal axis. In individual cases, e.g. bowl shapes with two very curved concave regions lateral to this point (e.g. in the case of a rectangular basic shape with rounded corners), the value can be at an azimuthal angle somewhat different to 180°, in particular in a range between 150° and 210°, preferably 160° and 200° or 170° and 190°. It need not cover the whole of these angle ranges.

If the flushing water then reaches a less curved region of the bowl opening, there is an increasing danger of it dropping undesirably strongly or of an undesirably large portion of it dropping.

Such a dropping flow portion could then meet the first flow path, or the first flow path portion provided according to the invention which proceeds at an angle of at

GBR-T 202869WO least between 90° and 270° relative to the azimuthal angle and preferably connects at the bottom to the entry opening in order to be able to guide the water exiting therefrom. Preferred lower limits for the above angle range are 80°, 70°, 60°, 50°, 40°, 30° and 20°, and preferred upper limits are 280°, 290°, 300°, 310°, 320°, 330° and 340°.

In order to mitigate the dropping of a portion of the flow, the invention provides for a second flow path or a second flow path portion, in this case again between an outer concave and inner convex edge and thereby higher than that portion of the first flow path/first flow path portion corresponding or adjacent to the azimuthal angle. In this case the second flow path or second portion should be provided at least between azimuthal angles of 310° and 340°. Preferred lower limits are 300°, 290°, 280°, 270° and 260°, whereby the second flow path preferably does not begin at angles below 200°. A preferred upper limit is 345°, whereby the second flow path is preferably not extended beyond 400° (in other words, more than 40° beyond 360°) if it does not already transition into the first flow path.

As already indicated above, according to this invention either the flow path known from EP 2 604 761 B1 can be extended, whereby a continuous flow path remains, or a second flow path can be added. The difference is ultimately whether or not there is an interruption between the two flow paths or portions, in particular at an azimuthal angle of 0°; this will be addressed in more detail below. In the following the description considers the second flow path, whereby for the case without interruption this is then to be understood as the second flow path portion of the same unified flow path. This applies analogously for the first flow path, which without the aforementioned interruption is therefore a first portion of the flow path and as such (without the second portion) is already known from EP 2 604 761 B1.

The second flow path should thus in particular not be completely circumferential, but instead only cover a limited region, namely where experience has shown there to be a particularly great danger of the water flow running along the bowl

GBR-T 202869WO inner wall dropping. This applies particularly to the “fourth quadrant” (counting from 0° with an ascending azimuthal angle). As this exemplary embodiment illustrates, the second flow path assists the flushing water flow at least partially and thereby prevents excessive manifestation of the already described mechanism of “reflection” on the first flow path.

The arguments so far are not dependent on whether one defines the azimuthal angle beginning with the value 0 at the front or rear, whereby these terms relate to the usual seated position of a WC user, “rear” thus designating that part of the bowl inner shape (relative to the horizontal) close to the buttocks. The arguments so far are further not dependent on whether the direction of rotation of the flushing water flow in the WC bowl is to the left or to the right, thus whether the azimuthal angle ascends clockwise or anticlockwise when seen in the top view. The more common and preferred case is a direction of rotation to the right as viewed from above, in other words a clockwise direction of rotation. Further, the case that the azimuthal angle is calculated from the rear is preferred. In this preferred case, therefore, the flow of flushing water from the entry opening is directed forwards out of it onto the concave curvature of the WC bowl inner shape (and would be directed to the rear if the zero point of the azimuthal angle were defined from the front). Both are possible, but the stated variant is preferred particularly in combination with a siphon outlet located more towards the rear.

In particular, the second flow path according to the invention, thus to a certain extent a second or extended shoulder in the bowl inner shape, could prevent a partial spillover of flushing water from the bowl, even if there is a small or disappearing undercut of the bowl inner shape at its upper edge. It should be noted that the flushing water entry opening necessarily requires an undercut, and that in this connection an “undercut-free” bowl inner shape still of course has an undercut at the entry opening. Rather, what is concerned here is the region just below the upper edge of the bowl inner shape, thus where the flush rim in classic WC bowls is located.

GBR-T 202869WO

The invention strives in principle for the simplest, most cleaning-friendly (and hence smooth) and most easily produced shape possible. As already explained, therefore, a bowl inner shape free from undercuts in the sense described is preferred.

In the same sense, a restriction to the one or the two described flow paths, thus dispensing with further flow paths, is preferred. Although no undercuts arise due to the flow paths, or at any rate preferably do not arise, the flow paths complicate the shape a little and do not make it a skilful configuration of the flushing water flow easier due to a number of different flow paths that is unnecessarily large from the point of view of the inventors. Of course, the first flow path in particular can have a considerable extension relative to the azimuthal angle, but this does not in any way alter the fact that it is a contiguous unified flow path.

The flow paths described with the present invention are intended to guide essential portions of the flushing water flow. This applies even more to the first flow path than to the second, because with the second only a portion, namely generally only a portion flowing somewhat higher along the bowl inner wall, is captured by the second flow path. In contrast to many structures to be found in the prior art, the two flow paths at any rate are relatively pronounced in respect of their width, whereby the width is understood to mean the dimension along the inner wall of the WC bowl and perpendicular to the longitudinal extension of the flow path, thus normally directed downwards relative to the local orientation of the face. Preferred minimum widths at the widest point are 12 cm for the first and 0.8 cm for the second flow path, whereby for the first flow path the following values 13 cm, 14 cm and 15 cm and for the second flow path the following values 0.9 cm, 1 cm and 1.1 cm are increasingly preferred in this order.

The object of the second flow path is, as explained, less to guide or assist a rotating downward flow than to prevent a part of the water flow dropping too sharply. It can to that extent proceed preferably approximately horizontally (relative to its longitudinal direction). Specifically, a reference can be drawn to a centre line be

GBR-T 202869WO tween the aforementioned convex and concave edges (in each case relative to the extreme values of the curvature), and this centre line should preferably have an angle of not more than 15°, but preferably not more than 13°, 11°, 9°, 7°, to the horizontal along the flow path. The flow path preferably slopes gently with the direction of flow, in other words the azimuthal angle.

The first flow path in turn corresponds substantially to the explanations in the previously cited EP patent 2 604 761 B1 of the same proprietor and accordingly proceeds at an increasing azimuthal angle on the one hand precipitously and on the other hand rotating along the bowl inner shape, in order to assist a flushing water flow directed downwards and rotating.

Accordingly, a bowl with an asymmetrical inner shape is provided which defines or generates a downward movement through the bowl inner shape comparable to a helical line by locating the first flow path deeper on one side than on the other. Accordingly, the very good surface cleaning properties of a rotational flow in the bowl are combined with a comparably pronounced momentum on entry into the siphon. Thus, the kinetic energy of the flushing water, resulting for instance from the height of the fall with respect to a cistern, can be used twice. In addition, the design of the inner shape of the bowl follows a downward tendency of the water flow caused by gravity and prevents some of the turbulence which is caused when water flows down independently of the inner shape of the bowl. Such turbulence reduces the kinetic energy of the flushing water. For comparable reasons, a rotational flushing water movement in the bowl, as known from the prior art, is for instance much more effective in terms of surface cleaning than the conventional approach comprising a classic flush rim, which significantly reduces the kinetic energy of the flushing water arriving from the flushing water supply.

The preponderant tangential velocity component of the flushing water emerging from the entry opening into the bowl, which velocity component is known from the prior art, relates to a projection of a central flushing water path onto a horizontal plane. Thus, the flushing water does not leave the entry opening in the direction

GBR-T 202869WO towards the water level in the siphon, but rather obliquely thereto, whereby in a general sense the exact angle does not matter and can depend on the individual geometry of the entry opening and the subsequent flow path. In particular, the velocity of the flushing water leaving the entry opening does not have to be exactly horizontal, but preferably is essentially horizontal.

The WC according to the invention can be implemented with different methods of generating the flushing water in terms of supplying it with a certain flushing water pressure, in particular with a pressurized water line, in other words without a cistern. However, combining the WC with a cistern is preferred because the invention allows use to be made in a particularly effective manner of the limited potential energy of the flushing water in a cistern. In particular, this applies to a concealed cistern in a mounting wall behind the WC.

In particular, relatively small quantities of flushing water can be sufficient due to the inventive concept, which has economic and ecological advantages. The maximum quantity of flushing water is preferably below 6 I, preferably below 5.5 I, and particularly preferably below 5 I.

The flushing water flow according to the invention allows a good wetting and cleaning of those faces of the inner shape of the bowl exposed to dirtying, namely by a rotating and therein sloping flow as described above. Accordingly, a conventional flush rim, which was compared with a shower at the beginning, can be dispensed with. This can simplify not only the manufacturing of the WC bowl but also its cleaning, because conventional flush rims are particularly susceptible to dirtying and calcification; furthermore, its bottom side is very hard to access. In other words, the invention enables a bowl showing a smooth transition from the actual inner faces of the bowl to the upper edge of the bowl, namely to those regions of the bowl which face upwards, in particular below a WC seat.

In one embodiment of the invention, the entry opening mentioned above (which is preferably the only entry opening), can be comparatively high, in particular higher

GBR-T 202869WO than 5 cm, and increasingly preferably higher than 5.5 cm, 6 cm, 6.5 cm in that order. A high entry opening allows a large cross-section, which favours the flow without unduly affecting the inner shape of the bowl by the entry opening, namely regarding both the flow configuration and also its aesthetic appearance.

In general, the flow cross-section of the flushing water supply is preferably comparatively large. In particular, in one embodiment of the invention it can, along the length of the flushing water supply within the WC, namely between the entry opening (including the entry opening) and the transition to portions of the ducting outside the WC itself, namely in particular within a mounting wall behind, amount to more than 8 cm², preferably to more than 9 cm², and particularly preferably to more than 10 cm² or even 11 cm². This applies particularly to the entry opening. Use can thereby be particularly well made of the kinetic energy of the flushing water resulting from a slope or a pressurised line.

It is further preferred that the second flow path, when it starts, maintains a certain distance from the entry opening at small azimuthal angles, namely preferably an azimuthal angle of at least 60°, but preferably 80°, 100°, 120°, 130°. This relates to the case that the first and second flow paths are not combined in a unified manner and to the direction of the rising azimuthal angle of the flow path.

The two flow paths each form a local reduction of the otherwise prevailing inclination of the bowl inner shape. According to a preferred embodiment of the invention, therefore, they should not be located at the rear in the bowl inner shape, at any rate preferably assuming a definition of the azimuthal angle from zero at this point, in other words of a flushing water flow from the entry opening to the front. Having regard to the tendency to dirtying, it has become apparent that an inner wall that is as smooth and steep as possible in the centre at any rate is to be preferred at the rear, and from the point of view of the inventors this aspect justifies restricting the flow paths in such a manner that they do not flow over this rear central portion. For an illustration, please refer to the exemplary embodiment. In

GBR-T 202869WO this case, therefore, the first and the second flow path are separate from one another.

It has further become apparent that the second flow path should proceed below a comparably steep portion of the inner shape of the bowl. Accordingly, an angle of inclination of at least 70° or even 75° to the horizontal in this portion above the second flow path is preferred, namely between an azimuthal angle of 310° and 340° and preferably along the entire longitudinal extension of the second flow path. This statement for a portion of the length of the second flow path or for its entire length then likewise preferably applies also to the entire portion of the bowl inner shape above it, namely up to an edge or rounding on the upper side that forms the transition to the upper side of the WC body.

Furthermore, a relatively pronounced steepness in the aforementioned central rear region of the WC bowl inner shape is preferred, namely at least downwards to the water level in the siphon and upwards to the aforementioned transition to the upper side of the bowl. Here too, the aforementioned angle values come into consideration.

Finally, such a steepness, again with the same angle values, is also particularly preferred on the opposing side, in other words centrally at the front, namely below the first flow path preferably located there (in other words, downwards from the convex edge) up to the water level in the siphon.

The statements on the steep wall in a portion of the height apply in a particularly preferable manner to the entire bowl inner shape.

The steep walls assist a good cleaning effect and a sufficient downward tendency of the water flow. The water flow should accordingly flow into the siphon with a clear downward tendency in order to be able to flush it well.

GBR-T 202869WO

The second flow path or the second flow path portion lies preferably comparably high in the frequently aforementioned angle range of between 310° and 340°, namely in particular above the first flow path (the first flow path portion), to the extent that this is likewise preferably extended to greater azimuthal angles beyond an azimuthal angle of 270° and into the range of and above an azimuthal angle of 310°. The two flow paths (flow path portions) are then at a distance from one another and arranged one above the other.

The second flow path (second flow path portion) is preferably located at least 3 cm higher than the first flow path (first flow path portion), whereby 3.5 cm, 4.0 cm, 4.5 cm, 5.0 cm are increasingly preferred.

Regardless thereof, the second flow path or the second flow path portion in the stated azimuthal angle range of between 310° and 340° is located preferably higher than the lower edge of the entry opening for the flushing water, thus again comparatively high. At this point this lower edge is preferably at least approximately at the same level as the first flow path, so that the entry opening injects the water onto the first flow path.

The invention is preferably realised with a WC bowl that has only one entry opening for flushing water at any rate in the upper region, in other words above the first flow path. Variants with a plurality of entry openings certainly exist in the prior art. This significantly complicates the WC body as a whole and is not really required for good flushing properties. Furthermore, this preferably also applies to the rest of the bowl under the first flow path. To this end, therefore, nozzle openings in the vicinity of the siphon that are occasionally used in the prior art to improve the drainage capacity are preferably dispensed with. The reasons are the same as those above, whereby another factor is a restriction of the overall water consumption.

In the following the invention is explained by means of an exemplary embodiment, whereby the individual features may also be material to the invention in

GBR-T 202869WO other combinations and, as already mentioned, relate implicitly to all categories of the invention.

Figures 1 and 2 show perspective top views from the front top right and front top left of a WC bowl according to the invention, in grey scales to illustrate the threedimensional form.

Figure 3 shows a side view of the right half of the WC bowl from Figures 1 and 2 in the longitudinally cut state.

Figure 4 shows a side view, but without grey scales and in a transversely cut state, of the WC bowl from Figures 1 - 3, namely looking towards the rear and with a simplified exemplary embodiment.

Figure 5 shows the exemplary embodiment from Figure 4 in adjacent side views drawn at the same height corresponding to Figure 3, but without grey scales.

Fig. 6 shows in a top view the exemplary embodiment from Figures 4 and 5 together with the azimuthal angle division, which is also intended to enable an understanding of the first exemplary embodiment.

Figures 1 to 6 show the invention by means of two WC bowls, whereby the first exemplary embodiment in Figures 1 to 3 is configured for the installation of a shower means of a shower WC and the corresponding recesses and openings are omitted from the second exemplary embodiment in Figures 4 to 6. These differences are not of particular importance for the invention, but they illustrate that the invention can also be combined very favourably with a shower WC.

Figures 1 and 2 show in perspective oblique views the WC bowl 1 of the first exemplary embodiment having a usual bowl opening 2, an opening 3 on the rear (in other words, drawn on the top right on the upper side in Figure 1 and drawn on the top left in Figure 2) for the installation of a shower means (not shown) and

GBR-T 202869WO having a depression 4 of the upper edge of the WC bowl around the bowl opening 2 on the rear portion of the bowl rim for the passage of a shower arm (not shown) for the shower arrangement. In the following the inner shape of the WC bowl 1 that is visible through the bowl opening 2 is of interest.

This corresponds initially in qualitative terms to the WC bowl known from the frequently cited EP 2 604 761 B1 in which is provided a first flow path 5 having an approximately helical form, which in this case starts at the rear and offset slightly to the right, such as at an azimuthal angle of 10°, and proceeds in a continuously sloping form having a widest point at an azimuthal angle of 180° almost all the way round to an azimuthal angle of about 350°, in other words to the rear again, but offset slightly to the left. Its function corresponds to the depictions in the cited prior art and further above in this description and does not need to be explained in detail.

Deviating from the cited prior art here, however, the entry opening 6 for the flushing water is not directed to the rear (offset slightly to the right) and to the left, as embodied in the prior art, but begins laterally at an azimuthal angle of about 100° and is directed to the front, in other words to greater azimuthal angles. Accordingly, the flushing water will be applied to the first flow path, but not when it starts (at 10°). For the rest, reference can be made to Fig. 6 for a better understanding of the azimuthal angle mentioned here.

Furthermore, in addition to the aforementioned prior art a second flow path 7, to a certain extent a further shoulder in the bowl inner wall above the first flow path 5, is provided in the rear left corner, hence clearly visible in Figure 1. This second flow path 7 is also strictly defined as an inner wall region between an (upper and outer) concave edge and a (lower and inner) convex edge. The second flow path 7 proceeds between about 250° and about 350° in respect of the azimuthal angle. It is thereby likewise configured slightly precipitously, namely with an approximate inclination (relative to a centre line, not drawn, between the convex and the concave edge) of about 5° as seen horizontally. At its widest point it is about

GBR-T 202869WO

1.2 cm wide, but much less flat than the first flow path 5, namely having an angle of approximately 48° to the horizontal at its flattest point. By contrast, at e.g. 180° the first flow path 5 has an inclination of only about 11° in relation to the horizontal plane and a greatest width of 16 cm. The aforementioned width here relates to the distance between the aforementioned edges (most convex and most concave line), namely the straight distance between them along the most precipitous direction, in other words the shortest distance.

By contrast, the bowl inner walls above and below the second flow path 7 are very steep with an inclination from the horizontal of about 80°, in particular also at an azimuthal angle of 0°. As Figs. 3 and 4 in particular show, the bowl walls become even steeper from there to the front and the inclination is about 89° at an azimuthal angle of 180°. It therefore precisely prevents an undercut.

Overall, the bowl inner shape thus has no undercut, as the figures likewise show, in particular not on the upper rim (and of course with the exception of the entry opening 6).

In this exemplary embodiment the two flow paths 5 and 7 are at a distance of about 6 cm apart, which is measured in the same manner as the path width, namely between the convex edge of the upper flow path 7 and the concave edge of the lower flow path 5 and exactly in the direction following the inclination. The second flow path 7 is thus significantly higher than the first flow path 5.

It can be imagined from the figures that, as a result of centrifugal forces, a water flow exiting the entry opening 6 will for an essential portion run along the steep bowl inner wall above the first flow path 5 and in this form be brought through the concave (as seen in the vertical top view) bowl inner wall to the other, namely left, side. Experience has shown that, as a result of gravity, the water flow on the left side tends increasingly downwards and in particular meets the portion of the first flow path 5 at small azimuthal angles, in other words about 10° to 90°, but also meets the opposing portion of the first flow path 5 at large azimuthal angles, in

GBR-T 202869WO other words about 300° to 350°. This leads to a reflection-like flow behaviour in which portions of the flushing water can tend sharply upwards and spill over out of the bowl 1.

If, as a result of the second flow path 7, this downward tendency is then countered by a certain obstacle in the illustrated azimuthal angle range, in particular between 310° and 340°, the behaviour described is attenuated or prevented, so that an undercut-free bowl inner shape with a flow behaviour of the flushing water that does not present the risk of spillover can be realised. It is in turn desirable that the first flow path 5 is configured to be extended in respect of the azimuthal angle and flatter in respect of the inclination in vertical sections (through the seal water level in the outflow pipe as shown in Fig. 3) in order to support the rotational character of the flushing water flow as much as possible and achieve optimum wetting of the bowl inner walls with the smallest possible quantities of flushing water.

Fig. 4 shows both a side view of the rear region of the bowl inner shape and a section through the bowl. The section plane runs through the seal water level in the lowest part of the WC bowl, the seal water level being drawn as 8. The second flow path 7 can be seen in the left portion of the bowl inner shape, the first flow path 5 in the right portion. Both are identified by border lines of the CAD program, which separate faces with a straight section profile in the vertical section (through the seal water level 8), such as for instance the steep bowl inner wall above the flow paths 5 and 7, from curved faces. To that extent it can be seen that the two flow paths 5 and 7 actually have a central strip that is straight in this sense and to which curved strips are connected at the top and at the bottom.

Figure 6 shows in a top view the second exemplary embodiment from Figures 4 and 5 with the azimuthal angle division and some values. It can in particular be seen that 0° corresponds to the rear centre of the bowl inner shape and 180° to the front centre. The azimuthal angle range for the flushing water entry opening of between 80° and 180° as defined in the claims can be identified. The front aziGBR-T 202869WO muthal angle range of between 150° and 210° in which according to the claims there is to be a concave curvature (not necessarily over this entire angle range) onto which the flushing water is directed on entry can also be identified. The minimum range of between 90° and 270° for the flow path can also be identified. Fur5 thermore, the limits of the minimum range (between 310° and 340°) for the second flow path or the second portion of the second flow path, which according to the claims is not to extend beyond the angle range of between 230° and 90°, is in the clockwise direction located offset a little to the left from the drawn line at 300° and in the same direction offset adjacent to the line at 330°.

In addition, Figure 6 also illustrates in a top view the bowl inner shape explained by means of the previous figures, whereby to avoid overloading the figures no references have been drawn in.

Claims

Claims

1. WC having a WC bowl (1), and an oval or round bowl opening (2), and an entry opening (6) for flushing water, wherein in the top view a longitudinal axis along a longitudinal extension of the oval and a transverse axis proceeding perpendicular to it and centrally define a centre point and, starting from the longitudinal axis and the centre point, an azimuthal angle, wherein the entry opening (6) for the flushing water is provided relative to the azimuthal angle between 80° and 180° and is directed in the direction of greater azimuthal angles, and in the top view and relative to the shape of the bowl opening (2) a tangential entry direction of the flushing water is thus given, so that after entry into the WC bowl (1) through the entry opening (6) the flushing water flowing on an inner wall of the WC bowl (1) meets at an azimuthal angle of 150° to 210° a curvature of the inner wall that is concave in the top view and relative to the centre point, wherein the WC bowl (1) has a flow path (5) for the flushing water which flow path (5) is defined in the inner shape of the WC bowl (1) between an outer concave edge and an inner convex edge in the vertical section and relative to the centre point and which flow path (5) connects to the entry opening in a lower region and proceeds relative to the azimuthal angle at least between 90° and 270°, characterised in that a flow path (7) is also provided at an azimuthal angle of between 230° and, once past 360°, 90°, but not beyond, but at least at an azimuthal angle of between 310° and 340°, which flow path (7) is likewise defined in the inner shape of the WC bowl (1) between an outer concave and an inner convex edge in the vertical section and relative to the centre point and therein is located higher than a further portion of the first flow path (5) at the same azimuthal angle.

GBR-T 202869WO
2. WC according to claim 1, having an upper rim of the WC bowl (1) which does not form an undercut inwards, in particular having an undercut-free WC bowl (1) with the exception of the entry opening (6).
3. WC according to claim 1 or 2 that has solely the flow path(s) (5, 7) mentioned in claim 1, in other words no further flow path.
4. WC according to one of the preceding claims, wherein between azimuthal angles of 90° and 270° the flow path (5) is at least 12 cm wide at its widest point and/or between azimuthal angles of 310° and 340° the flow path (7) is at least 0.8 cm wide at its widest point.
5. WC according to one of the preceding claims, wherein the second flow path (7) proceeds with a maximum deviation from the horizontal of +/- 15°, preferably somewhat precipitously with an increasing azimuthal angle.
6. WC according to one of the preceding claims, wherein the flow path (5) proceeds precipitously between azimuthal angles of 90° and 270° and thereby assists a downwards-directed movement of flushing water entering through the entry opening (6), whereby those portions of the flow path (5) between azimuthal angles of 90° and 270° that are closest to the entry opening (6) are located higher than those portions closest to the rest of the flow path (7) between azimuthal angles of 310° and 340°.
7. WC according to one of the preceding claims, wherein the flow path between azimuthal angles of 310° and 340° and the flow path between azimuthal angles of 90° and 270° continually merge with one another beyond 0° and thereby form a single flow path.
8. WC according to one of claims 1 to 6, wherein the azimuthal angle of 0° relative to a seated position of a WC user is located at the rear, in other

GBR-T 202869WO words close to the buttocks, and at this position of 0° no flow path (5, 7) exists, whereby the flow path (5) between azimuthal angles of 90° and 270° and the flow path (7) between azimuthal angles of 310° and 340° are two separate flow paths (5, 7).
9. WC according to one of the preceding claims, wherein the WC bowl inner shape above the flow path (7) between azimuthal angles of 310° and 340° has a steepness of at least 70° from the horizontal.
10. WC according to one of the preceding claims, wherein the azimuthal angle of 0° relative to a seated position of a WC user is located at the rear, in other words close to the buttocks, and wherein the inner shape of the WC bowl (1) at this azimuthal angle of 0° has a steepness of at least 70° from the horizontal between a siphon water level upper level (8) and an upper transition on the upper side to the upper side of the bowl.
11. WC according to one of the preceding claims, wherein the azimuthal angle of 0° relative to a seated position of a WC is located at the rear, in other words close to the buttons, and wherein at an opposing point, in other words at an azimuthal angle of 180°, the inner shape of the bowl (1) has a steepness of at least 70° from the horizontal between a convex edge limiting the flow path (5) and from there downwards to a siphon water level upper level (8).
12. WC according to one of the preceding claims, wherein between azimuthal angles of 90° and 270° the flow path (5) is continuously extended towards greater azimuthal angles and proceeds at least partially at the same azimuthal angles of between 310° and 340° as the flow path (7), but at a distance from and below the latter.

GBR-T 202869WO
13. WC according to one of the preceding claims, wherein between azimuthal angles of 310° and 340° the flow path (7) is located higher overall than a lower edge of the entry opening (6) for the flushing water.
14. WC system having a WC according to one of the preceding claims and a cistern, preferably a concealed cistern, preferably with a flushing quantity below 6 I.
15. Use of a WC or WC system according to one of the preceding claims for flushing, wherein from the entry opening (6) the flushing water performs a rotational movement along the flow path (5) and a portion of the flushing water is therein guided above the flow path (7) between 310° and 340°.