CN109923267B

CN109923267B - Drainage fitting

Info

Publication number: CN109923267B
Application number: CN201780069053.0A
Authority: CN
Inventors: 阿尔佛雷德·马勒
Original assignee: Geberit International AG
Current assignee: Geberit International AG
Priority date: 2016-11-09
Filing date: 2017-11-07
Publication date: 2021-05-14
Anticipated expiration: 2037-11-07
Also published as: AU2017357537B2; PL3538716T3; EP3538716B1; AU2017357537A1; ES2856214T3; EP3538716A1; DK3538716T3; WO2018087070A1; CN109923267A

Abstract

The invention relates to a drain fitting (1) for a flush tank, comprising: a valve body (2) having a sealing element (4) cooperating with the valve seat (3) and a float (5), wherein the valve body (2) together with the sealing element (4) is movable along a central axis (M) from a rest position to a flushing position from the valve seat (3) to the rest position; and a float chamber (6) having an opening (28) through which the valve body (2) extends, wherein the float (5) is movable along the central axis (M) within the float chamber (6) and is in hydraulic cooperation with the float chamber (6). The float chamber (6) comprises at least one control channel (7) through which air from an outer region (8) of the float chamber (6) can enter the float chamber (6) as soon as the flushing water level (S) around the drain fitting (1) drops to the level of the control channel (7) so that the pressure ratio between the float chamber (6) and the outer region (8) of the float chamber (6) can be equalized, wherein the float (5) can be moved from the flushing position to the rest position when the pressure ratio is equalized. The float chamber (6) has a base (9) extending completely around the central axis (M) and a breather tube (10) adjoining the base (9). Preferably, the cross section of the vent tube portion (10), viewed transversely to the central axis (M), is smaller than the cross section of the base portion (9), wherein the column portion (11) of the float (5) extends into the vent tube portion (10).

Description

Drainage fitting

Technical Field

The present invention relates to a drain fitting.

Background

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

EP 0722020, for example, shows a flushing device of this type. For partial flushing, a weight body is arranged which can be selectively connected to the valve body.

From DE 102007001718, another drain fitting is known, which has an extension adjoining the float chamber. Such a drain fitting is disadvantageous due to hydrostatic and hydrodynamic conditions, since the valve body moves very fast from the flushing position to the closed position, and a loud noise is generated when the closing body hits the valve seat.

Disclosure of Invention

In view of this prior art, it is an object of the present invention to define a drain fitting that overcomes the disadvantages of the prior art. In particular, it is a preferred object to define a drain fitting that closes with less noise.

This object is achieved by a drain fitting as described hereinafter. Accordingly, a drain fitting for a water tank includes: a valve body and a float having a sealing element cooperating with the valve seat, wherein the valve body together with the sealing element is movable along a central axis from a rest position to a flushing position and from the flushing position to 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 along the central axis within the float chamber and is in hydraulic engagement with the float chamber. The float chamber comprises at least one control channel through which air from the outer region of the float chamber can enter the float chamber once the flush water level surrounding the drain fitting drops to the level of the control channel, so that the pressure ratio between the float chamber and the outer region of the float chamber can equalize, wherein the float can move from the flushing position to the rest position upon equalization of the pressure ratio. The float chamber has a base that extends completely around the central axis and has a vent tube portion that abuts the base. The cross-section of the vent tube portion, viewed transversely to the central axis, is smaller than the cross-section of the base portion. The float has a lower portion, a column portion extending away from the lower portion, wherein the float extends into the snorkel portion with the column portion. The lower portion extends and moves substantially to the base.

The advantage of the float extending into the vent tube portion is that as the volume of the float increases, the proportion of water in the float chamber that presses on the float can be reduced, thereby reducing the noise generated during the closing operation.

In addition, by arranging the vent pipe portion having a smaller cross section than the base portion, the volume of the float chamber can be enlarged without adversely affecting the structural size of the drain fitting or the function thereof. This has the advantage that, due to the increased volume, the optimization of the closing operation can be simplified.

As mentioned before, below the cylindrical portion, the float has a lower portion, wherein the lower portion is substantially cylindrical, in particular cylindrical, and in the flushing position, preferably fills or substantially fills the base of the float chamber.

The columnar portion is preferably configured as a float. Particularly preferably, the column portion and the lower portion are configured substantially as a gas-filled chamber.

The expression "extending to" is understood to mean that the cylindrical portion extends to the vent tube portion both in the flushing position and in the rest position.

The expression "venting duct portion" is understood to be a portion that supplements the base portion upwards in the mounted position.

Preferably, the float or cavity is closed upwardly. This means that air cannot escape from the top of the float. Thus, the lower portion and the columnar portion are closed upward. This means that the lower part and the column part have no openings through which air can escape from the top. Thus, a float is provided which is completely closed upwards. The advantage is therefore that the float always experiences buoyancy in a situation surrounded by water. Active control of the float can also be omitted.

In other words, the float has a cavity that is closed upwards. An upwardly closed cavity is formed by the columnar portion and the lower portion. Preferably, the cavity of the float, seen from below, is provided with: a circumferential sidewall extending around the lower portion; a transition wall extending transverse to or at an angle to the circumferential side wall, which bounds a top of the lower portion; a circumferential side wall adjoining the transition wall at the top and laterally bounding the columnar portion; and a top wall closing a top of the columnar portion. The top wall extends transverse to or at an angle to the circumferential side wall.

In this connection, "upwardly" refers to the direction looking upwardly from the valve seat in the assembled position, i.e. away from the valve seat.

In a preferred variant, the lower part is open downwards. If the tank is filled, air remains in the lower portion and the column due to the closed configuration with the lower portion and the column facing upwards. Buoyancy is provided by air. It is particularly preferred that the lower part is kept open downwards at each moment and is substantially limited by said side walls of the lower part. This means that no opening is provided which needs to be controlled in any way to provide the float function.

In a second variant, the lower part can also be closed.

Preferably, the valve body further has an overflow pipe, around which a float with a column and a lower part extends externally, in particular such that the overflow pipe extends centrally through the float, such that the column and the lower part have a circular cross section. Preferably, the float is integrally formed with the overflow tube by the top wall which bounds the top of the column.

It is particularly preferred that the overflow pipe extends upwardly above the cylindrical portion and downwardly out of the bottom portion. The sealing member may be connected to the overflow tube.

Preferably, the float having a cylindrical portion and a lower portion is free of movable parts that require active control to perform the float function.

Preferably, the vent tube portion of the float chamber extends substantially concentrically to the base. The vent tube portion and base portion are preferably concentrically positioned one above the other. Wherein the extent of the venting tube portion, viewed transversely to the central axis, is preferably smaller than the extent of the base portion.

In this context, "concentric" may be understood as the vent tube portion and the base portion extending about a common central axis. Wherein the two parts are configured such that they extend concentrically around the central axis.

Preferably, the cylindrical portion of the float extends substantially concentrically to the lower portion. The pillar portion and the lower portion are preferably concentrically located one above the other. Wherein the extent of the columnar portion, viewed transversely to the central axis, is preferably smaller than the extent of the lower portion.

In this context, "concentric" is understood to mean that the pillar portion and the lower portion extend around a common central axis. Wherein the two parts are configured such that they extend concentrically around the central axis.

The external shape of the float having a lower portion and a cylindrical portion and the internal shape of the float chamber having a base and a vent tube portion are such that the float can move in the float chamber. The two shapes are configured such that they are substantially matched and, if desired, have a certain clearance between each other.

Preferably, the vent tube portion is located within the maximum diameter of the base portion as viewed from the central axis direction. Therefore, the diameter of the vent tube portion is smaller than the diameter of the base portion. The same is true of the diameter ratio between the lower portion and the pillar portion.

Preferably, the vent tube portion and the base portion extend completely around the central axis and preferably each have a substantially constant diameter. The venting tube portion and the base portion are thus configured substantially as a cylinder, in particular with a circular area. Wherein the diameter of the vent tube portion is smaller than the diameter of the base portion.

Preferably, the cylindrical portion and the lower portion extend completely circumferentially around the central axis and preferably each have a substantially constant diameter. Thus, the columnar portion and the lower portion are configured substantially as a cylinder, in particular having a circular area. Wherein the diameter of the columnar part is smaller than that of the lower part.

Preferably, the transition between the vent tube portion and the base portion is configured to be conical. By means of such a transition, a reduction of the diameter from the base to the venting tube portion is achieved.

Preferably, the height of the base, viewed in the direction of the central axis, is substantially less than the height of the ventilation tube portion, wherein the height of the base is preferably 5% to 20% of the height of the entire float chamber. Therefore, a compact arrangement of the drain fitting can be achieved.

Preferably, the height of the lower portion, viewed in the direction of the central axis, is substantially smaller than the height of the vent tube portion, wherein the height of the lower portion is preferably 5% to 20% of the height of the entire float. The height of the entire float consists of the height of the lower part and the height of the column.

Preferably, therefore, the float chamber, the vent tube portion and the base portion are configured to be completely closed laterally with the side walls up to the end walls, except for the at least one control passage. In the downward direction, the float chamber is configured to be open. Preferably, there is a support opening in the end wall, in which support opening the valve body is movably mounted.

Preferably, a water storage tank is present above the float chamber, the water storage tank having a passage leading to the float chamber, wherein through the passage water in the water storage tank is able to flow into the float chamber. The water storage tank is filled when the water tank is filled and is configured to be able to empty when the water tank is empty only through the passage. The water storage tank can also be called a cistern.

Preferably, in the flush position, the lower portion of the float is substantially entirely located in the float chamber. That is, when the flush is triggered, the lower portion moves substantially completely into the float chamber.

In the flushing position, the sealing element of the valve body is particularly preferably located substantially completely in the float chamber. Thus, the sealing element is protected from the water flowing through.

Preferably, the column portion substantially completely fills the cross section of the vent tube portion, or at least 55%, in particular at least 75%, as seen in a cross section transverse to the central axis. That is, the columnar portion extends substantially completely or almost over a substantial portion of the cross-section of the vent tube portion, as viewed in a cross-section transverse to the central axis.

Preferably, the column portion substantially completely fills the volume of the vent tube portion, or at least 55% or at least 90% when the float is in the flush position. In this context, "substantially completely" means that the post and the vent pipe portion are arranged relative to each other such that a residual amount of water is always present between the post and the vent pipe portion. An advantage of this arrangement is that the proportion of water that presses on the float when it moves from the flushing position to the rest position can be kept small.

Particularly preferably, a gap exists between the outside of the columnar portion and the inside of the vent tube portion.

Preferably, the control channel is configured to trigger a first flush using a first flush volume. Furthermore, the drain fitting comprises a control unit for controlling the second flush volume. When the water level set for the second flushing quantity is reached, the control unit provides a closing force to the valve body using the closing weight, wherein the closing force can be connected from the control unit to the valve body via the switching element.

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

Preferably, the height position of the closing weight is configured such that it can be adjusted within an adjustment range. That is, the closing weight can move within the adjustment range. At the upper level, less water is discharged during the flushing than at the lower level.

Preferably, the first flush is a full flush and the second flush is a partial flush. That is, when the shut-off weight is activated, a partial flush is triggered, and when the water level reaches the control channel, a full flush is triggered.

Alternatively, the first flush is a partial flush and the second flush is a full flush. That is, when the shut-off weight is activated, a full flush is triggered, and when the water level reaches the control channel, a partial flush is triggered.

Preferably, a plurality of control channels are arranged at different height positions, wherein the drain fitting further comprises at least one closing element by means of which one of the control channels can be opened and the other control channels can be closed.

Preferably, the closing element is a slide valve which is movably mounted on the outside of the drain fitting.

Preferably, at least one control channel is arranged in the vent pipe portion, wherein other control channels (if present) are arranged in the vent pipe portion and/or the base portion.

Preferably, the adjustment range of the closing weight extends at least to below the highest control channel in height. Thus, a high degree of overlap between the control unit and the control channel can be achieved, thereby increasing the flexibility of the drainage adjustment.

Preferably, the control unit is disposed outside the vent tube portion and is movable up and down near the vent tube portion.

Preferably, the vent tube portion includes an opening for venting gas during filling of the float chamber.

Drawings

Preferred embodiments of the present invention are described below based on the accompanying drawings, which are for illustrative purposes only and should not be construed as limiting. In the drawings:

FIG. 1a/1b shows a perspective view of an embodiment of a drain fitting according to the present invention;

FIG. 2 shows a cross-sectional view of the drain fitting according to FIG. 1 in a rest position;

FIG. 3 shows another cross-sectional view of the drain fitting according to FIG. 1 in a flushing position;

FIG. 4 shows a schematic view of a drain fitting in a rest position according to the present disclosure;

FIG. 5 shows a schematic view of a drain fitting according to the present invention with respect to a full flush; and

fig. 6 shows a schematic view of a drain fitting according to the present invention with respect to partial flushing.

Detailed Description

In the drawings, a drain fitting 1 for a cistern is shown. The drain fitting 1 comprises a valve body 2 having a sealing element 4 and a float 5, the sealing element 4 cooperating with a valve seat. The valve body 2 together with the sealing element 4 is movable from the valve seat 3 along the central axis M from a rest position to a flushing position and from the flushing position to the rest position. In the flushing position, water can flow out through the gap between the valve seat 3 and the sealing element 4.

In addition, the drain fitting 1 includes 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 here moves essentially along the central axis M within the float chamber 6 and is hydraulically coupled with the float chamber 6.

The float chamber 6 is configured such that it is completely closed laterally by the side walls 34 up to the end wall 19, except for the at least one control channel 7. Wherein the control channel 7 passes through the side wall 34. The side wall 34 limits the base 9 and the vent tube portion 10 in an 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 channel 7, so that once the flushing water level S around the drain fitting 1 drops at the level of the control channel 7, air can enter the float chamber 6 from an outer region 8 of the float chamber 6, so that the pressure ratio between the float chamber 6 and the outer region 8 of the float chamber 6 can be equalized. When equilibrium is reached, the float 5 or the valve body 2 can be moved from the flushing position to the rest position.

The float 5 extends into the breather pipe portion 10 together with the column portion 11. Thus, the volumes associated with lifting and lowering are optimally utilized, and the movement of the valve body 2 can be optimized. Below the column 11, the float preferably has a lower part 29, the lower part 29 moving up and down in the base 9. The float 5 is completely closed upwards. This means that air can enter through the lower part 29 of the float, but air cannot escape from the top.

The internal shape of the float chamber 6 is explained in more detail based on fig. 2 and 3. The float chamber 6 comprises a cylindrical, in particular cylindrical, base 9 and a ventilation pipe section 10 adjacent to the base 9, wherein the base 9 extends completely circumferentially around the central axis M. Wherein the vent tube portion 10 abuts the base portion 9. In the mounted position, the base 9 is located below the vent tube portion 10, and the vent tube portion 10 is located above the base 9. In other words, the breather pipe portion 10 extends the float chamber 6 upward from the base portion 9. In the upward direction, the vent tube portion 10 is bounded by an end wall 19.

Wherein the cross-section of the venting tube portion 10, viewed transversely to the central axis M, is smaller than the cross-section of the base portion 9. The volume of the vent tube portion 10 is preferably greater than the volume of the base portion 9.

The vent tube portion 10 extends substantially concentrically to the base portion 9. That is, two cylinders or cylinders each extend around a common central axis M. The vent tube portion 10 has a constant diameter throughout its height H10. Likewise, the base 9 has the same diameter over its entire height H9. Here, the diameter means an inner diameter. Wherein the inner diameter of the base portion 9 is larger than the inner diameter of the ventilation tube portion 10.

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

The outer shape of the float 5 is explained in more detail on the basis of fig. 2 and 3. The external shape of the float 5 is configured to match or substantially resemble the internal shape of the float chamber 6. That is, the inner shape is equal or similar to the outer shape. As described herein, it is advantageous if there is a gap between the inner shape and the outer shape.

The lower part 29 of the float 5 has a cylindrical, in particular cylindrical, outer shape. The cylindrical portion 11 of the float 5 has a cylindrical, in particular cylindrical, outer shape. The outer diameter of the cylindrical outer shape in the region of the column 11 and in the region of the lower part 29 is preferably constant.

Centrally, an overflow tube 33 extends through the float 5. That is, the columnar portion 11 and the lower portion 29 have circular inner cross sections.

The transition from the lower part 29 to the cylindrical part 11 is configured here as a jump in diameter. As shown, a transition wall is provided which is fully closed upwards in the region of the diameter jump. The transition wall has the reference number 35.

The cylindrical portion 11 extends substantially concentrically to the lower portion 29. That is, two cylinders or cylinders each extend around a common central axis M. The column 11 is closed upwards in the region of its upper end 18 by a top wall 36. Top wall 36 extends from side wall 37 of cylindrical portion 11 to side wall 38 of overflow tube 33. The top wall 36 is closed upwards, which means that it has no opening. The cylindrical portion 11 and the lower portion 29 have a constant diameter, wherein the diameter of the cylindrical portion 11 is smaller than the diameter of the lower portion 29. Here, the diameter means an outer diameter.

Preferably, the outer diameter of the lower portion 29 substantially corresponds to the outer diameter of the sealing element 4.

In the embodiment shown, both the lower portion 29 and the column portion 11 are configured as cavities such that they rise in the water. The cavity is closed upwards so that no air can escape upwards from the float 5 or the lower part 29 and the column part 11. Wherein the cavity provided by the two parts can be filled with air. In the illustrated embodiment, the cavity is configured to be closed upwardly and open downwardly. It can also be configured as a closed cavity.

In the embodiment shown, seen from below upwards, the cavity of the float 5 is provided with a circumferential side wall 37 extending around the lower part 29, a transition wall 35 extending transversely to the circumferential side wall and bounding the top of the lower part 29, a circumferential side wall 38 abutting the transition wall 35 upwards and bounding the column part laterally, and an end wall 36 closing the top of the column part 11. In the region of the lower part 29, the float 5 is open downwards.

By means of the sectional views of fig. 2 and 3, it is shown that the column portion 11 substantially fills the cross section of the vent tube portion 10 as seen in a cross section transverse to the central axis M. The filling degree is preferably at least 70% when the column 11 and the float 5 are in the flushing position. However, the column portion 11 can also fill at least 80% of the vent tube portion 10, or substantially completely.

Based on fig. 4 to 6, the respective partial features of the drain fitting 1 according to the invention are now explained in more detail.

In fig. 4, the float 5 is in a rest position. Wherein the sealing element 4 is pressed against the valve seat 3. When the first flush is triggered, the float 5 is lifted by the actuation portion 22. Due to the cooperation between the float 5 and the float chamber 6, the float 5 is kept in its flushing position. The float 5 remains in its flushing position until the flushing water level S drops to the level shown in fig. 5. When this water level is reached, air can enter the float chamber 6 through the control channel 7, and the hydraulic balance between the float 5 and the float chamber 6 is disturbed, thereby causing the float 5 to drop from the flushing position to the rest position in the direction of the valve seat 3.

The second flush is shown in fig. 6. The float 5 is in this case lifted by means of an actuator 23, which actuator 23 is part of the control unit 12. This results in an engagement between the switching element 14 and the closing weight 13. Wherein the closing weight 13 has the form of a cup filled with water. As soon as the flushing water level drops to the level shown in fig. 6, the weight of the water in the closing weight 13 is effective and exerts a force on the float 5 via the switching element 14. Due to this force, the float 5 then moves from the flushing position in the direction of the valve seat 3 to the rest position.

As shown in the figures, the cylindrical portion 11 is arranged so that its upper end 26 is at a distance from the end wall 19 of the vent tube portion 10 when the valve body 2 is in the flushing position. Due to this distance, a certain amount of residual water will be present in the float chamber 6. However, the distance cannot be too large, otherwise the closing noise increases.

Preferably, there is a certain gap between the outside 20 of the columnar portion 11 and the inside 21 of the vent tube portion 10. On the one hand, this gap facilitates relative movement between the cylindrical portion 11 and the vent tube portion 10. On the other hand, it is ensured that a certain amount of residual water is always present in this region.

The arrangement of the vent tube portion 10 and the column portion 11 having a reduced diameter relative to the base portion 9 or the lower portion 29, respectively, has the advantage that a portion of the control unit 12, in particular the closing weight 13, can extend downwardly close to the vent tube portion 10. That is, a part of the control unit 12 can move up and down near the vent tube part 10.

The vent tube portion 10 has a height H10 as viewed from the direction of the central axis M. The height H10 is greater than the height H9 of the base 9. The moving path of the control unit 12 can be further increased. The height H9 of the base portion 9 is substantially less than the height H10 of the vent tube portion. Preferably, the height H9 of the base 9 is 5% to 20% of the height H of the entire float chamber 5.

A similar height ratio is provided on the float 5 between the height H29 of the lower portion 29 and the height H11 of the column 11.

As mentioned above, the control channel 7 is configured to trigger a first flush using a first flush volume. The control unit 12 is configured to control the second flush volume. The first flush volume is preferably a full flush volume and the second flush volume is preferably a partial flush volume.

In the embodiment shown, a plurality of control channels 7 are arranged. The control channels 7 are here located at different heights. The first control channel 7 is located here in the upper end region of the ventilation tube section 10. The other control channels 7 are arranged in the vent tube portion 10. That is, in the illustrated embodiment, the control passages 7 are distributed in height over the vent tube portion 10. However, additional control channels may also be arranged in the base part 9. In this case, the control channels 7 are distributed in height over the base 9 and the vent tube portion 10.

The drain fitting 1 further comprises at least one closing element 16, by means of which a respective one of the control channels 7 can be opened and the remaining control channels 7 can be closed. That is, the installer can define which control channel 7 should be the active control channel using the closure element. The other control channels 7 are then closed accordingly.

At least one control channel 7 is provided in the vent tube portion 10. The remaining control channels 7 are provided in the vent tube portion 10 or the base portion 9.

The closing weight 13 is adjustable according to an adjustment range 15. That is, the closing weight 13 can be adjusted according to its height. Whereby the appropriate amount of rinsing water can be determined. Preferably, the adjustment range 15 extends at least below the highest control channel 7 depending on its height. Therefore, the overlapping of the flush water amounts can be achieved.

In the embodiment shown, the control unit 12 further comprises a strut 24, wherein the closing weight 13 is mounted on the strut such that it can be adjusted relative to the strut 24. The switching element 14 is controlled by means of a suitably configured control surface 25, wherein the control surface 25 is arranged on the housing in the vicinity of the water storage tank 31.

Below the float chamber 6, the outlet fitting comprises a connecting element 26, on which connecting element 26 a valve seat 3 is arranged, wherein the connecting element 26 can be connected to the water tank. The connecting element 26 has a plurality of through-holes 27 through which flushing water can flow to the valve seat 3.

Above the float chamber 6 there is an optional water storage tank 31 with a passage 32 to the float chamber 6. Through the passage 32, the water in the storage tank 31 can then flow into the float chamber 6.

List of reference numerals

1 drainage fitting 24 strut

2 valve body 25 control surface

3 valve seat 26 connecting element

4 sealing the through hole of the element 27

5 float 28 opening

6 lower part of the float chamber 29

7 control passage 30 transition

8 outer zone 31 tank of float chamber

9 base 32 channel

10 vent tube part 33 overflow tube

11 side wall of pillar portion 34

12 control unit 35 transition wall

13 closing the top wall of the weight 36

14 side wall of switching element 37

15 adjustment range 38 side wall

16 closure element 39 central axis

18 upper end S flushing level

19 height of end wall H

20 outside

21 inner side

22 actuator part

23 actuating part

Claims

1. A drain fitting (1) for a cistern, comprising:

a valve body (2) and a float (5) with a sealing element (4), wherein the sealing element cooperates with a valve seat (3), the valve body (2) together with the sealing element (4) moves from the valve seat (3) along a central axis (M) from a rest position to a flushing position and from the flushing position to the rest position, and

a float chamber (6) having an opening (28) through which the valve body (2) extends, wherein the float (5) is movable along a central axis (M) within the float chamber (6) and is in hydraulic cooperation with the float chamber (6),

wherein the float chamber (6) comprises at least one control channel (7), air from an outer region (8) of the float chamber (6) being able to enter the float chamber (6) through the control channel (7) as soon as the flushing water level (S) around the drain fitting (1) drops to the level of the control channel (7), such that a pressure ratio between the float chamber (6) and the outer region (8) of the float chamber (6) can be equalized, wherein, after equalizing the pressure ratio, the float (5) can be moved together with the valve body (2) from the flushing position to the rest position,

wherein the float chamber (6) has a base (9) extending completely around the central axis (M) and a venting tube portion (10) adjoining the base (9),

wherein the cross-section of the venting tube portion (10) is smaller than the cross-section of the base portion (9) viewed transversely to the central axis (M), and

the float having a lower portion (29), a column portion (11) extending away from the lower portion (29), wherein the float (5) extends into the vent tube portion (10) with the column portion (11);

and wherein the valve body (2) comprises an overflow pipe (33), wherein the float (5) with the column (11) and the lower part (29) surrounds the overflow pipe (33) from the outside such that the overflow pipe (33) extends centrally through the float (5) such that the column (11) and the lower part (29) have a circular cross section.

2. A drain fitting (1) according to claim 1, characterized in that the lower part (29) of the float (5) and the column (11) are closed upwards; and/or the lower part (29) is open or closed downwards.

3. A drain fitting (1) according to claim 1, characterized in that the overflow pipe extends above the cylindrical portion (11).

4. A drain fitting (1) according to claim 1 or 2, characterized in that the vent tube portion (10) extends substantially concentrically to the base portion (9) and/or the column portion (11) extends substantially concentrically to the lower portion (29).

5. A drain fitting (1) according to claim 1 or 2, characterized in that the vent tube portion (10) and the base portion (9) extend completely around a central axis (M);

and/or the cylindrical portion (11) and the lower portion (29) extend completely around the central axis (M).

6. A drain fitting (1) according to claim 1 or 2, characterized in that the transition (30) between the vent tube portion (10) and the base portion (9) is conically configured.

7. A drain fitting (1) according to claim 1 or 2,

-the height (H9) of the base (9), viewed in the direction of the central axis (M), is less than the height (H10) of the venting tube portion (10);

and/or the height (H29) of the lower part (29) is smaller than the height (H11) of the column (11) as seen in the direction of the central axis (M).

8. A drain fitting (1) according to claim 1 or 2, characterized in that the float chamber (6) is configured such that it is laterally completely closed up to the end wall (19) except for at least one control channel (7).

9. A drain fitting (1) according to claim 1 or 2, characterized in that above the float chamber (6) there is a water storage tank (31), said water storage tank (31) having a passage (32) leading out to the float chamber (6), wherein water in the water storage tank (31) can subsequently flow into the float chamber (6) through said passage (32).

10. A drain fitting (1) according to claim 1 or 2, characterized in that in a flushing position the lower part (29) of the float (5) is located substantially completely in the float chamber (6) and/or in that in a flushing position the sealing element (4) of the valve body is located substantially completely in the float chamber (6).

11. A drain fitting (1) according to claim 1 or 2,

the column (11) substantially completely fills the cross section of the ventilation tube section (10), or at least 55%, and/or is filled with air, as viewed in a cross section transverse to the central axis (M)

When the float is in the flushing position, the column (11) substantially completely fills the volume of the vent tube portion (10), or at least 55% or at least 90%.

12. A drain fitting (1) according to claim 1, characterized in that the control channel (7) is configured to trigger a first flush with a first flush amount, and in that the drain fitting (1) further comprises a control unit (12) for controlling a second flush amount, wherein the control unit (12) provides a closing force (F) to the valve body (2) using a closing weight (13) when a water level set for the second flush amount is reached, wherein the closing force (F) or the closing weight (13) can be connected from the control unit (12) to the valve body (2) by means of a switching element (14).

13. A drain fitting (1) according to claim 12, characterized in that the switch element (14) automatically enters into a locking connection with the valve body (2) when the control unit (12) is raised, and/or that the height position of the closing weight (13) is configured to be adjustable within an adjustment range (15).

14. A drain fitting (1) according to claim 12 or 13,

the first flush is a full flush and the second flush is a partial flush; or

The first flush is a partial flush and the second flush is a full flush.

15. A drain fitting (1) according to claim 1 or 2, characterized in that a plurality of control channels (7) are arranged at different height positions, wherein the drain fitting (1) further comprises at least one closing element (16), by means of which closing element (16) one of the control channels (7) can be opened and the other control channel (7) can be closed.

16. A drain fitting (1) according to claim 12 or 13, characterized in that the adjustment range (15) of the closing weight (13) extends in height at least below the highest control channel (7).

17. A drain fitting (1) according to claim 1, characterized in that the float (5) is formed integrally with the overflow pipe (33).

18. A drain fitting (1) according to claim 5, characterized in that the vent tube portion (10) and the base portion (9) each have a substantially constant diameter; and/or

The columnar portion (11) and the lower portion (29) each have a substantially constant diameter.

19. A drain fitting (1) according to claim 7, characterized in that the height (H9) of the base (9) is 5% to 20% of the height (H) of the entire float chamber (6); and/or

The height (H29) of the lower part (29) is 5% to 20% of the height (H) of the entire float (5).

20. A drain fitting (1) according to claim 11, characterized in that the cylindrical portion (11) fills at least 75% of the cross-section of the vent tube portion (10).

21. A drain fitting (1) according to claim 15, characterized in that at least one of the control channels (7) is arranged in a vent tube portion (10), and wherein the other control channels (7) are arranged in the vent tube portion (10) and/or the base portion (9).