AU2017357537B2

AU2017357537B2 - Drain fitting

Info

Publication number: AU2017357537B2
Application number: AU2017357537A
Authority: AU
Inventors: Alfred Mahler
Original assignee: Geberit International AG
Current assignee: Geberit International AG
Priority date: 2016-11-09
Filing date: 2017-11-07
Publication date: 2022-10-27
Anticipated expiration: 2037-11-07
Also published as: DK3538716T3; PL3538716T3; EP3538716A1; EP3538716B1; ES2856214T3; WO2018087070A1; AU2017357537A1; CN109923267B; CN109923267A

Abstract

The invention relates to a drain fitting (1) for a flush tank, comprising a valve body (2) having a sealing element (4), which interacts with a valve seat (3), and having a float (5), wherein the valve body (2) together with the sealing element (4) for the valve seat (3) can be moved along a center axis (M) from an idle position into a flushing position and from the flushing position into the idle position, and comprising a float chamber (6) having an opening (28), through which the valve body (2) extends, wherein the float (5) can be moved within the float chamber (6) along the center axis (M) and hydraulically interacts with the float chamber (6). The float chamber (6) comprises at least one control passage (7), through which, as soon as a flushing water level (S) surrounding the drain fitting (1) is lowered to the height of the control passage (7), air can enter the float chamber (6) from regions (8) outside of the float chamber (6) in such a way that pressure can be equalized between the float chamber (6) and the regions (8) outside of the float chamber (6), wherein the float (5) can be moved from the flushing position into the idle position upon equalization of pressure. The float chamber (6) has a base section (9), which extends completely around the center axis (M), and a snorkel section (10), which adjoins the base section (9). Viewed transversely to the center axis (M), the cross-section of the snorkel section (10) is preferably smaller than the cross-section of the base section (9), wherein a column section (11) of the float (5) extends into the snorkel section (10).

Description

TITLE DRAIN FITTING TECHNICAL FIELD

The present invention relates to a drain fitting according to the preamble of Claim 1.

PRIOR ART

From the prior art, drain fittings for triggering flushes from a cistern have become known. In particular, drain fittings for selectively triggering a full flush or partial flush have become known.

For instance, EP 0 722 020 shows a flushing device of this type. For the partial flush, a weight body, which can selectively be connected up to the valve body, is arranged.

From DE 10 2007 001718, a further drain fitting, which has an extension portion adjoining the float chamber, has become known. This drain fitting is disadvantageous because, due to the '0 hydrostatic and hydrodynamic conditions, the valve body reaches a high speed in the movement from the flushing position into the closure position, which leads to very loud noises when the closure body strikes the valve seat.

Reference to any prior art in the specification is not an acknowledgement or suggestion that this prior art forms part of the common general knowledge in any jurisdiction or that this prior art could reasonably be expected to be combined with any other piece of prior art by a skilled person in the art.

By way of clarification and for avoidance of doubt, as used herein and except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additions, components, integers or steps.

REPRESENTATION OF THE INVENTION It is an object of the invention to define a drain fitting which overcomes at least one of the drawbacks of the prior art. In particular, it is a preferred object for at least one embodiment of the invention to define a drain fitting which closes with less noise.

In one aspect, the present invention provides a drain fitting for a cistern comprising a valve body having a sealing element, which cooperates with a valve seat, and a float, wherein the valve body is movable with the sealing element off the valve seat along a centre axis from a rest position into a flushing position, and from the flushing position into the rest position, and a float chamber having an opening through which the valve body extends and is movably mounted therein, wherein the float is movable within the float chamber along the centre axis and hydraulically cooperates with the float chamber. The float chamber comprises at least one control passage, through which, as soon as a flush water level surrounding the drain fitting has fallen to the height of the control passage, air from regions outside the float chamber can pass into the float chamber, such that the pressure ratios between the float chamber and the regions outside the float chamber can be equalized, wherein the float, upon equalization of the pressure ratios, is movable from the flushing position into the rest position. The float chamber has a base portion, extending fully around the centre axis, and a snorkel portion, adjoining the base portion. The cross section of the snorkel portion, viewed transversely to the centre axis, is smaller than the cross section of the base portion. The float has a lower portion, away from which extends a pillar portion, wherein the float extends with the pillar portion into the snorkel '0 portion. The valve body comprises an overflow pipe, wherein the float with the pillar portion and the lower portion surround the overflow pipe externally, in particular such that the overflow pipe extends centrically through the float so that the pillar portion and the lower portion have a cross section of a cylindrical ring.

The lower portion may extend and move substantially into the base portion.

The extension of the float into the snorkel portion yields the advantage that, with the enlarged volume of the float, the proportion of water which in the float chamber presses onto the float can be reduced, whereby the noise formation during the closing operation can be reduced.

In addition, by arranging the snorkel portion with a smaller cross section than the base portion, the volume of the float chamber can be enlarged without the structural size of the drainfitting, or its function, respectively, being adversely affected. This has the advantage that, due to the increased volume, a simplified optimization of the closing operation is enabled. Beneath the pillar portion, the float, as mentioned, has a lower portion, wherein the lower portion is of substantially cylindrical, in particular circular cylindrical, configuration, and in flushing position preferably fills, or substantially fills, respectively, the base portion of the float chamber.

The pillar portion is preferably configured as a float. Particularly preferably, the pillar portion, as well as the lower portion, is configured substantially as an air-filled cavity.

The expression "extend into" is understood in that the pillar portion, both in flushing position and in rest position, extends into the snorkel portion.

The expression "snorkel portion" is understood as a portion which, in the installation position, supplements the base portion in the upward direction.

Preferably the float or the cavity are closed towards the top. This means that towards the top no air can escape from the float. Thereby the lower portion and the pillar portion are closed towards the top. This means that the lower portion and the pillar portion are provided without an opening, through which air may escape towards the top. The float as provided is thereby fully closed towards the top. Therefore the advantage occurs that the float always experiences a buoyancy force in case the float is circumvented by water. Also an active control of the float '0 can be omitted.

With other words the float has a cavity which is closed towards the top. The cavity as closed towards the top is provided by the pillar portion and the lower portion. Preferably the cavity of the float as seen from below is provided with a circumferential sidewall, which extends around the lower portion, with a transverse or angularly to the circumferential sidewall running transition wall, which limits the lower portion to the top, with a circumferential side wall which adjoins the transition wall towards the top and limits the pillar portion laterally, and with a top wall which closes the pillar portion to the top. The top wall extends transversily or angularly to the circumferential sidewall.

"Towards the top" refers in this connection in an assembled position to a direction as seen from the valve seat toward the top, meaning from the valve seat away.

In a preferred variant the lower portion is open towards the bottom. In case the cistern will be filled air remains in the lower portion and the pillar portion due the closed structure of the lower portion and the pillar portion towards the top. By means of the air the buoyancy force is provided. Particularly preferably the lower portion remains open towards the bottom at every time und is substantially limited by the lower portion. This means that no opening is provided which needs to be controlled in any way in order to provide the function of the float.

In a second variant, the lower portion could also be closed.

The float is preferably integrally formed by means of said top wall, which limits the pillar portion to the top, to the overflow pipe.

Particularly preferably the overflow pipe extends towards the top over and above the pillar portion and extends towards the bottom out of the lower portion. The seal may be connected to the overflow pipe.

Preferably the float with the pillar portion and the lower portion have no moveable parts which would need to be controlled in an active manner for their float function.

Preferably, the snorkel portion of the float chamber extends substantially concentrically to the base portion. The snorkel portion and the base portion lie preferably concentrically one above '0 the other. Therein, the extent of the snorkel portion, viewed transversely to the centre axis, is preferably smaller than the extent of the base portion.

"Concentrically" is understood, in the present context, in that the snorkel portion and the base portion extend around a common centre axis. Therein, the two portions are configured such that they run circumferentially around the centre axis.

Preferably, the pillar portion of the float extends substantially concentrically to the lower portion. The pillar portion and the lower portion preferably lie concentrically one above the other. Therein, the extent of the pillar portion, viewed transversely to the centre axis, is preferably smaller than the extent of the lower portion.

"Concentrically" is understood, in the present context, in that the pillar portion and the lower portion extend around a common centre axis. Therein, the two portions are configured such that they run circumferentially around the centre axis.

The external shape of the float comprising the lower portion and the pillar portion, and the internal shape of the float chamber comprising the base portion and the snorkel portion, are such that the float is movable in the float chamber. The two shapes are configured such that they are substantially matching, if need be with clearance relative to each other.

Preferably, the snorkel portion, viewed in the direction of the centre axis, lies within the maximal diameter of the base portion. The diameter of the snorkel portion is thus smaller than that of the base portion. The same can be said of the diameter ratio between the lower portion and the pillar portion.

Preferably, the snorkel portion and the base portion extend fully around the centre axis and preferably have substantially respectively constant diameters. The snorkel portion and the base portion are thus configured substantially as cylinders, in particular with a circular base area. Thererin, the diameter of the snorkel portion is smaller than that of the base portion.

Preferably, the pillar portion and the lower portion extend fully circumferentially around the centre axis and preferably have substantially respectively constant diameters. The pillar portion and the lower portion are thus configured substantially as cylinders, in particular with a circular base area. Therein, the diameter of the pillar portion is smaller than that of the lower portion.

Preferably, the transition between snorkel portion and base portion is conically configured. Via this transition, the reduction in diameter from the base portion to the snorkel portion is achieved.

Preferably, the height of the base portion, viewed in the direction of the centre axis, is substantially smaller than the height of the snorkel portion, wherein the height of the base portion is preferably between 5% and 20% of the height of the total float chamber. As a

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result, a compact configuration of the drain fitting can be achieved.

Preferably, the height of the lower portion, viewed in the direction of the centre axis, is substantially smaller than the height of the pillar portion, wherein the height of the lower portion is preferably between 5% and 20% of the height of the total float. The height of the total float is made up of the height of the lower portion and the height of the pillar.

Preferably, the float chamber, thus the snorkel portion and the base portion, apart from the at least one control passage, is configured such that it is laterally completely closed with a side wall up to an end wall. In the downward direction, the float chamber is configured open. Preferably present in the end wall is the bearing opening, in which the valve body is movably mounted.

Above the float chamber a water storage tank is preferably present, which with a passage opens out into the float chamber, wherein, through the passage, water which is in the water storage tank can after-flow into the float chamber. The water storage tank is filled upon the filling of the cistern and is configured such that it can empty, upon emptying of the cistern, only via the passage. The water storage tank can also be referred to as a reservoir.

Preferably, the lower portion of the float lies, in the flushing position, substantially fully in the float chamber. That is to say, the lower portion, when a flush is triggered, is moved substantially fully into the float chamber.

Particularly preferredly, the sealing element of the valve body lies, in the flushing position, substantially fully in the float chamber. The sealing element is hereby protected from the water which is flowing past.

Preferably, the pillar portion, viewed in cross section transversely to the centre axis, fills the cross section of the snorkel portion substantially fully or to at least 55%, in particular to at least 75%. That is to say, the pillar portion, viewed in cross section transversely to the centre axis, extends substantially fully or almost fully over a large part of the cross section of the snorkel portion.

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Preferably, the pillar portion fills the volume of the snorkel portion substantially fully, or to at least 55% or to at least 90%, when the float is in flushing position. In this context, "substantially fully" means that pillar portion and snorkel portion stand relative to each other such that between pillar portion and snorkel portion a residual quantity of water is always present. Said configurations have the advantage that the proportion of water which presses onto the float when the float moves from the flushing position into the rest position can be kept small.

Particularly preferredly, clearance is present between the outer sides of the pillar portion and the inner sides of the snorkel portion.

Preferably, the control passage is configured for the triggering of a first flush with a first flush quantity. In addition the drain fitting comprises a control unit for the control of a second flush quantity. When a water level provided for the second flush quantity is reached, the control unit provides with a closing weight a closing force onto the valve body, wherein the closing force can be connected from the control unit up to the valve body via a switching member.

Preferably, the switching member, when the control unit is raised, enters automatically into a latching connection with the valve body.

Preferably, the height position of the closing weight is configured such that it is adjustable over a range of adjustment. That is to say that the closing weight can be moved over the range of adjustment. At a higher position, less water is removed during the flushing operation than at a lower position.

Preferably, the first flush is a full flush, and the second flush is a partial flush. That is to say, when the closing weight is activated a partial flush is triggered, and when the control passage is reached by the water level a full flush is triggered.

Alternatively, the first flush is a partial flush, and the second flush is a full flush. That is to say, when the closing weight is activated, a full flush is triggered, and when the control passage is reached by the water level, a partial flush is triggered.

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Preferably, a plurality of control passages are arranged at different height positions, wherein the drain fitting additionally comprises at least one closure element, with which one of the control passages can be opened up and the others of the control passages can be closed off.

The closure element is preferably a slide valve, which is movably mounted on the outer side of the drain fitting.

Preferably, at least one of the control passages is arranged in the snorkel portion, wherein the others of the control passages, where present, are arranged in the snorkel portion and/or in the base portion.

Preferably, the range of adjustment of the closing weight extends, in terms of its height, at least to beneath the uppermost control passage. As a result, an overlap of the heights between the control unit and the control passage can be achieved, which increases the flexibility of adjustment of the water removal.

Preferably, the control unit is disposed outside the snorkel portion and can move up and down next to the snorkel portion.

Preferably, the snorkel portion comprises an opening for air evacuation during the filling of the float chamber.

Further embodiments are defined in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below on the basis of the drawings, which serve merely for illustrative purposes and should not be interpreted restrictively. In the drawings:

Fig. la/lb show a perspective view of one embodiment of a drain fitting according to

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the invention; Fig. 2 shows a sectional representation through the drain fitting according to Figure 1 in rest position; Fig. 3 shows a further sectional representation through the drain fitting according to Figure 1 in flushing position; Fig. 4 shows a schematic representation of the drain fitting according to the invention in rest position; Fig. 5 shows a schematic representation of the drain fitting according to the invention in respect of a full flush; and Fig. 6 shows a schematic representation of the drain fitting according to the invention in respect of a partial flush.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the figures, a drain fitting 1 for a cistern is shown. The drain fitting 1 comprises a valve body 2 having a sealing element 4, which cooperates with a valve seat, and having a float 5. The valve body 2 is movable with the sealing element 4 off the valve seat 3 along a centre axis M, from a rest position into a flushing position, and from the flushing position into the rest position. In the flushing position, water can flow off through the gap between valve seat 3 and sealing element 4.

In addition, the drain fitting 1 comprises a float chamber 6. The float chamber 6 has an opening 28, through which the valve body 2 extends. The valve body 2 is movably mounted in the opening 28. The float 5 is here movable substantially within the float chamber 6 along the centre axis M and hydraulically cooperates with the float chamber 6.

The float chamber 6 is configured such that, apart from the at least one control passage 7, it is laterally completely closed with a side wall 34, up to an end wall 19. Therein, the control passages 7 penetrate the side wall 34. The side wall 34 limits the base portion 9 and the snorkel portion 10 in the outward direction. The opening 28 is located in the end wall 19. In the downward direction, the float chamber 6 is open.

The float chamber 6 comprises at least one control passage 7, through which, as soon as a

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flush water level S surrounding the drain fitting 1, at the height of the control passage 7, has fallen, air can pass from regions 8 outside the float chamber 6 into the float chamber 6, such that the pressure ratios between float chamber 6 and regions 8 outside the float chamber 6 can be equalized. Upon this equalization, the float 5 or the valve body 2 is movable from the flushing position into the rest position.

The float 5 extends with a pillar portion 11 into the snorkel portion 10. As a result, the volumes relevant to the uplift and the lowering are optimally utilized and the movement of the valve body 2 can be optimized. Beneath the pillar portion 11, the float preferably has a lower portion 29, which is movable up and down in the base portion 9. The float 5 is towards the top fully closed. This means that air can enter via the lower portion 29 in the float and that it is not possible that air escapes towards the top.

The internal shape of the float chamber 6 is explained in greater detail on the basis of Figures 2 and 3. The float chamber 6 comprises a cylindrical, in particular circular cylindrical, base portion 9, which circumferentially extends fully around the centre axis M, and a snorkel portion 10, which adjoins the base portion 9. Therein, the snorkel portion 10 adjoins the base portion 9. In the installation position, the base portion 9 lies beneath the snorkel portion 10, and the snorkel portion 10 lies above the base portion 9. It can also be said that the snorkel portion 10 lengthens the float chamber 6 upwards from the base portion 9. In the upward direction, the snorkel portion 10 is limited by the end wall 19.

Therein, the cross section of the snorkel portion 10, viewed transversely to the centre axis M, is smaller than the cross section of the base portion 9. The volume of the snorkel portion 10 is preferably larger than that of the base portion 9.

The snorkel portion 10 extends substantially concentrically to the base portion 9. That is to say, the two cylinders or circular cylinders, respectively, extend about the common centre axis M. The snorkel portion 10 has, over its entire height H1, a constant diameter. Equally, the base portion 9 has over its entire height H9 likewise a same diameter. The diameter is in this context the internal diameter. Therein, the internal diameter of the base portion 9 is larger than the internal diameter of the snorkel portion 10.

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In the shown embodiment, the transition 30 between the base portion 9 and the snorkel portion 10 is conically configured. That is to say, in the region of the transition 30, the diameter of the float chamber reduces from the larger diameter of the base portion 9 to the smaller diameter of the snorkel portion 10.

The external shape of the float 5 is explained in greater detail on the basis of Figures 2 and 3. The external shape of the float 5 is configured matching to or substantially similar to the internal shape of the float chamber 6. That is to say, the internal shape is equal in shape or similar in shape to the external shape. As mentioned herein, it is advantageous if clearance is present between internal shape and external shape.

The lower portion 29 of the float 5 has a cylindrical, in particular circular cylindrical, external shape. The pillar portion 11 of the float 5 has a cylindrical, in particular circular cylindrical, external shape. The external diameter of the cylindrical external shape in the region of the pillar portion 11 and in the region of the lower portion 29 is preferably constant.

In the centre, an overflow pipe 33 extends through the float 5. That is to say, the pillar portion 11 and also the lower portion 29 have on the inside the cross section of a cylinder ring.

The transition from the lower portion 29 to the pillar portion 11 is here configured as a jump in diameter. As shown from the figures, there is provided a transiation wall, which is fully closed towards the top, in the region of the jump in diameter. The transition wall has the reference numeral 35.

The pillar portion 11 extends substantially concentrically to the lower portion 29. That is to say, the two cylinders or circular cylinders, respectively, extend about the common centre axis M. Towards the top the pillar portion 11 is in the region of its upper end 18 closed with a top wall 36. The top wall 36 extends from the side wall 37 of the pillar portion 11 to the side wall 38 of the overflow pipe 33. The top wall 36 is closed towards the top which means that it does not have an opening. The pillar portion 11 and the lower portion 29 have a constant diameter, wherein the diameter of the pillar portion 11 is smaller than the

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diameter of the lower portion 29. The diameter is in this context the external diameter.

The external diameter of the lower portion 29 preferably substantially corresponds to the external diameter of the sealing element 4.

In the shown embodiments, both the lower portion 29 and the pillar portion 11 are each configured as a cavity, so that they experience an uplift in the water. The cavity is slcoes towards the top so that no air can escape from the float 5 or the lower portion 29 and the pillar portion 11 towards the top. Therein, the cavity provided by the two portions can be filled with air. In the shown embodiments, the cavity is configured closed in the upward direction and open in the downward direction. It can also be configured as a closed cavity.

In the shown embodiments the cavity of the float 5 as seen from below is provided with a circumferential sidewall 37, which extends around the lower portion 29, with a transverse to the circumferential sidewall running transition wall 35, which limits the lower portion 29 to the top, with a circumferential side wall 38 which adjoins the transition wall 35 towards the top and limits the pillar portion laterally, and with a top wall 36 which closes the pillar portion 11 to the top. Towards the bottom, here in the region of the lower portion 29, the float is open.

By the sectional representations of Figures 2 and 3 it is shown that the pillar portion 11, viewed in cross section transversely to the centre axis M, substantially fills the cross section of the snorkel portion 10. The degree of filling is preferably at least 70% when the pillar portion 11 is, with the float 5, in the flushing position. However, the pillar portion 11 can also fill the snorkel portion 10 to at least 80%, or else substantially completely.

On the basis of Figures 4 to 6, individual partial features of the drain fitting 1 according to the invention are now explained in greater detail.

In Figure 4, the float 5 is in the rest position. Therein, the sealing element 4 bears on the valve seat 3. When a first flush is triggered, the float 5 is raised via an actuating portion 22. Due to the cooperation between the float 5 and the float chamber 6, the float 5 stays in its flushing position. The float 5 remains in its flushing position until such time as the flush water level S is lowered to the level illustrated in Figure 5. When this level is reached, air can pass through the control passage 7 into the float chamber 6 and the hydraulic equilibrium between float 5 and float chamber 6 is disturbed, whereby the float 5 falls, in the direction of the valve seat 3, from the flushing position into the rest position.

In Figure 6, a second flush is shown. In this case, the float 5 is raised with an actuating portion 23, which here is part of a control unit 12. This leads to an engagement between the switching member 14 and the closing weight 13. Therein, the closing weight 13 has the form of a beaker, which fills with water. As soon as the flush water level has now lowered to the level illustrated in Figure 6, the weight of the water in the closing weight 13 takes effect and, via the switching member 14, a force is applied to the float 5. Due to this force, the float 5 is then moved from its flushing position, in the direction of the valve seat 3, into its rest position.

As shown in the figures, the pillar portion 11 is configured such that, when the valve body 2 is in the flushing position, its upper end 26 lies at a distance from the end wall 19 of the snorkel portion 10. Due to this distance, a certain quantity of residual water is then found in the float chamber 6. However, the distance must not be too great, otherwise the closing noises increase.

Preferably, a certain clearance is present between the outer sides 20 of the pillar portion 11 and the inner sides 21 of the snorkel portion 10. On the one hand, this clearance is advantageous in respect of the relative movement between pillar portion 11 and snorkel portion 10. On the other hand, it is ensured that a certain quantity of residual water is always present in this region.

The configuration of the snorkel portion 10 and of the pillar portion 11 with the reduced diameter in relation to the base portion 9 and lower portion 29, respectively, has the advantage that parts of the control unit 12, in particular the closing weight 13, can extend downwards next to the snorkel portion 10. That is to say, parts of the control unit 12 can move up and down next to the snorkel portion 10.

Viewed in the direction of the centre axis M, the snorkel portion 10 has a height H1O. The

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height H1O is here larger than the height H9 of the base portion 9. The path of movement of the control unit 12 can hereby be further increased. The height H9 of the base portion 9 is substantially smaller than the height H1O of the snorkel portion. Preferably, the height H9 of the base portion 9 is between 5% and 20% of the height H of the total float chamber 5.

Similar height ratios are provided on the float 5 between the height H29 of the lower portion 29 and the height H11 of the pillar portion 11.

As explained above, the control passage 7 is configured for the triggering of a first flush with a first flush quantity. The control unit 12 is configured for the control of a second flush quantity. The first flush quantity is preferably a full-flush quantity, and the second flush quantity is preferably a partial-flush quantity.

In the shown embodiment, a plurality of control passages 7 are arranged. The control passages 7 here lie at different heights. A first control passage 7 here lies in the region of the upper end of the snorkel portion 10. Further control passages 7 are arranged in the snorkel portion 10. That is to say, in the shown embodiment the control passages 7 are distributed, in terms of their height, over the snorkel portion 10. It is also possible, however, for additional control passages to be arranged in the base portion 9. In that case, the control passages 7 would be arranged distributed, in terms of their height, over the base portion 9 and the snorkel portion 10.

The drain fitting 1 further comprises at least one closure element 16, with which respectively one of the control passages 7 can be opened up and the others of the control passages 7 can be closed off. That is to say, an installer can define with the closure element which of the control passages 7 should be the active control passage. The other control passages 7 are then correspondingly closed off.

At least one of the control passages 7 is thus disposed in the snorkel portion 10. The other control passages 7 are disposed either in the snorkel portion 10 or in the base portion 9.

The closing weight 13 is adjustable over a range of adjustment 15. That is to say, the

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closing weight 13 can be adjusted in terms of its height. The appropriate flush water quantity can hereby be defined. Preferably, the range of adjustment 15 extends, in terms of its height, at least to beneath the uppermost control passage 7. An overlap of the flush water quantities can hence be achieved.

In the shown embodiment, the control unit 12 additionally comprises a bearing rod 24, wherein the closing weight 13 is mounted on the bearing rod such that it is adjustable relative to the bearing rod 24. The switching member 14 is controlled via an appropriately configured control surface 25, which is here arranged on the housing in the region of the water storage tank 31.

Beneath the float chamber 6, the drain fitting here comprises a connecting element 26, on which the valve seat 3 is disposed, wherein the connecting element 26 is connectable to a cistern. The connecting element 26 has a plurality of through holes 27, through which the flush water can then flow to the valve seat 3.

Above the float chamber 6, an optional water storage tank 31 is present, which with a passage 32 opens out into the float chamber 6. Through the passage 32, water which is in the water storage tank 31 can after-flow into the float chamber 6.

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LIST OF REFERENCE SIGNS

1 drain fitting 23 actuating portion 2 valve body 24 bearing rod 3 valve seat 25 control surface 4 sealing element 26 connecting element float 27 through holes 6 float chamber 28 opening 7 control passage 29 lower portion 8 regions outside the float 30 transition chamber 31 water storage tank 9 base portion 32 passage snorkel portion 33 overflow pipe 11 pillar portion 34 side wall 12 control unit 35 transisition wall 13 closing weight 36 top wall 14 switching member 37 side wall range of adjustment 38 side wall 16 closure element M centre axis 18 upperend S flush water level 19 end wall H heights outer side 21 inner side 22 actuating portion

Claims

1. Drain fitting for a cistern, comprising a valve body having a sealing element, which cooperates with a valve seat, and a float, wherein the valve body is movable with the sealing element off the valve seat along a centre axis from a rest position into a flushing position, and from the flushing position into the rest position, and a float chamber having an opening through which the valve body extends, wherein the float is movable within the float chamber along the centre axis and hydraulically cooperates with the float chamber, wherein the float chamber comprises at least one control passage, through which, as soon as a flush water level surrounding the drain fitting has fallen to the height of the control passage, air from regions outside the float chamber can pass into the float chamber, such that the pressure ratios between the float chamber and the regions outside the float chamber can be equalized, wherein the float, upon equalization of the pressure ratios, is movable with the valve body from the flushing position into the rest position wherein the float chamber has a base portion, extending fully around the centre axis, and a snorkel portion, adjoining the base portion, wherein the cross section of the snorkel portion, viewed transversely to the centre axis, is smaller than the cross section of the base portion, wherein the float has a lower portion, away from which extends a pillar portion, wherein the float extends with the pillar portion into the snorkel portion; wherein the valve body comprises an overflow pipe, wherein the float with the pillar portion and the lower portion surround the overflow pipe externally, in particular such that the overflow pipe extends centrically through the float so that the pillar portion and the lower portion have a cross section of a cylindrical ring.

2. Drain fitting according to claim 1, wherein the float, in particular the lower portion as well as the pillar portion are closed towards the top; and/or wherein the lower portion is open or closed towards the bottom.

3. Drain fitting according to any one of the preceding claims, wherein the float is integrally formed with the overflow pipe.

4. Drain fitting according to any one of the preceding claims, wherein the overflow pipe extends over and above the pillar portion.

5. Drain fitting according to any one of the preceding claims, wherein the snorkel portion extends substantially concentrically to the base portion, and/or wherein the pillar portion extends substantially concentrically to the lower portion.

6. Drain fitting according to any one of the preceding claims, wherein the snorkel portion and the base portion extend fully around the centre axis and preferably have substantially respectively constant diameters; and/or wherein the pillar portion and the lower portion extend fully around the centre axis and preferably have substantially respectively constant diameters.

7. Drain fitting according to any one of the preceding claims, wherein the transition between snorkel portion and base portion is conically configured.

8. Drain fitting according to any one of the preceding claims, wherein the height of the base portion, viewed in the direction of the centre axis, is substantially smaller than the height of the snorkel portion, wherein the height of the base portion is preferably between 5% and 20% of the height of the entire float chamber, and/or wherein the height of the lower portion, viewed in the direction of the centre axis, is substantially smaller than the height of the pillar portion, wherein the height of the lower portion is preferably between 5% and 20% of the height of the entire float.

9. Drain fitting according to any one of the preceding claims, wherein the float chamber, apart from the at least one control passage, is configured such that it is laterally completely closed up to an end wall.

10. Drain fitting according to any one of the preceding claims, wherein above the float chamber a water storage tank is present, which with a passage opens out into the float chamber, wherein, through the passage, water which is in the water storage tank can after flow into the float chamber.

11. Drain fitting according to any one of the preceding claims, wherein the lower portion of the float lies, in the flushing position, substantially fully in the float chamber, and/or wherein the sealing element of the valve body lies, in the flushing position, substantially fully in the float chamber.

12. Drain fitting according to any one of the preceding claims, wherein the pillar portion, viewed in cross section transversely to the centre axis, fills the cross section of the snorkel portion substantially completely or to at least 55%, in particular at least 75%, and/or wherein the pillar portion fills the volume of the snorkel portion substantially completely, or to at least 55% or to at least 90%, when the float is in flushing position.

13. Drain fitting according to any one of the preceding claims, wherein the control passage is configured for the triggering of a first flush with a first flush quantity, and wherein the drain fitting additionally comprises a control unit for the control of a second flush quantity, wherein the control unit, when a water level provided for the second flush quantity is reached, provides with a closing weight a closing force onto the valve body, wherein the closing force or the closing weight can be connected from the control unit up to the valve body via a switching member.

14. Drain fitting according to claim 13, wherein the switching member, when the control unit is raised, enters automatically into a latching connection with the valve body, and/or wherein the height position of the closing weight is configured such that it is adjustable over a range of adjustment.

15. Drain fitting according to any one of claims 13 to 14, wherein the first flush is a full flush, and wherein the second flush is a partial flush; or wherein the first flush is a partial flush, and wherein the second flush is a full flush.

16. Drain fitting according to any one of the preceding claims, wherein a plurality of control passages are arranged at different height positions, wherein the drain fitting additionally comprises at least one closure element, with which one of the control passages can be opened up and the others of the control passages can be closed off, wherein, preferably, at least one of the control passages is arranged in the snorkel portion, and wherein the optional others of the control passages are arranged in the snorkel portion and/or in the base portion.

17. Drain fitting according to any one of claims 13 to 16, wherein the range of adjustment of the closing weight extends, in terms of its height, at least to beneath the uppermost control passage.