WO2019145051A1

WO2019145051A1 - Overflow system for a sink

Info

Publication number: WO2019145051A1
Application number: PCT/EP2018/052105
Authority: WO
Inventors: Christian W. Bomatter; Rolf Neeser
Original assignee: Franke Technology And Trademark Ltd
Priority date: 2018-01-29
Filing date: 2018-01-29
Publication date: 2019-08-01

Abstract

We propose an overflow system (7) for a sink (1), comprising: a valve body (6) to be mounted on said sink (1), which valve body (6) is of overall tube-like design with a tube axis (A) and a tube wall (6a) that has a first open end (6b) for mounting on said sink (1), in fluid connection with a drain opening of said sink (1), as well as a second open end (6c) for connecting to a drainpipe; a first opening (6d) in said tube wall (6a) at a first distance (d1) from said first open end (6b) and a second opening (6e) in said tube wall (6a) at a second distance (d2) from said first open end (6b), which second distance (d2) is greater than said first distance (d1); an overflow channel member (8) in fluid connection with said first opening (6d) on one side and with said second opening (6e) on the other side, thus providing an overflow fluid connection from said first opening (6d) to said second opening (6e) through said overflow channel member (8) while bypassing at least a portion of said valve body (6), wherein a portion of said overflow channel member (8) extends beyond said first open end (6b) of the valve body (6) in a direction along the tube axis (A); a first sealing member (9a) and a second sealing member (10), both located inside the valve body (6), wherein said first sealing member (9a) and said second sealing member (10) are moveable relative to each other along said tube axis (A) between an open position, in which there is an open fluid connection from said first open end (6b) to said second open end (6c) through said valve body (6) along the tube axis (A), and a closed position, in which said fluid connection is blocked, said first sealing member (9a) having at least one overflow opening (9b) which is part of said overflow fluid connection from said first open end (6b) to said second open end (6c) through said overflow opening (9b) and said overflow channel member (8); characterized in that a cross section of said overflow channel member (8), at least in a connection region comprising at least one of said first opening (6d) and said second opening (6e) in said tube wall (6a), is flat, with a maximum extension in direction along the tube axis (A) being smaller than a maximum extension in a direction across the tube axis (A).

Description

Overflow system for a sink

Description

The present application relates to an overflow system for a sink according to the preamble of claim 1 .

Said overflow system comprises a valve body to be mounted on said sink, which valve body is of overall tube-like design with a tube axis and a tube wall that has a first open end for mounting on said sink, in fluid connection with a drain open- ing of said sink, as well as a second open end for connecting to a drainpipe; a first opening in said tube wall at a first distance from said first open end and a second opening in said tube wall at a second distance from said first open end, which second distance is greater than said first distance; an overflow channel member in fluid connection with said first opening on one side and with said second opening on the other side, thus providing an overflow fluid connection from said first opening to said second opening through said overflow channel member while bypassing at least a portion of said valve body, wherein a portion of said overflow channel member extends beyond said first open end of the valve body in a direction along the tube axis; a first sealing member and a sec- ond sealing member, both located inside the valve body, wherein said first seal- ing member and said second sealing member are moveable relative to each other along said tube axis between an open position, in which there is an open fluid connection from said first open end to said second open end through said valve body along the tube axis, and a closed position, in which said fluid con- nection is blocked, said first sealing member having at least one overflow open- ing which is part of said overflow fluid connection from said first open end to said second open end through said overflow opening and said overflow channel member.

According to a further aspect, the application relates to a sink according to claim 15.

Said sink, in particular a kitchen sink, has at least one bowl with a bottom wall and a circumferential side wall, at least one outlet opening located in said bot- tom wall, and an overflow system according to said first aspect of the invention. The valve body of said overflow system is mounted on said sink underneath said bottom wall at said outlet opening, said first open end of the valve body of said overflow system being in fluid connection with said outlet opening.

Sink overflow systems of the above-defined type are known from, e. g.,

EP 2 453 065 A2, EP 2 045 403 A1 , EP 2 037 051 A2, EP 1 593 784 A2,

EP 446 177 A1 , EP 342 723 A1 , EP 305 572 A1 or WO 2014/087151 A1 , to name only a few. A common disadvantage with overflow systems of this type is that they present a rather large vertical size which entails difficulties when mounting such systems underneath an already installed (kitchen) sink. Further- more, known overflow systems of the above-defined type are often conceived for installation with a single type of sink, for which they are designed, thus entailing a restricted flexibility of use. Also, known overflow systems of the above-defined type may suffer from a restriction of the maximum rate at which water can be drained through the overflow system (drain rate).

It is an object of the present invention to provide a new overflow system for a sink of the above-defined type which does not suffer from the above-mentioned disadvantages which presents a low construction height, which is adaptable to various sinks of various forms and sizes, and which ensures a high water drain rate, which may be of the order of 12 litres per minute (l/min).

The object is achieved by means of an overflow system for a sink according to claim 1 . Preferred further embodiments of the inventive overflow system are de- fined in the subclaims.

According to another aspect of the invention, the object is achieved by means of a sink according to claim 15.

According to the first aspect of the present invention, an overflow system for a sink, in particular for a kitchen sink, comprises: a valve body to be mounted on said sink, which valve body is of overall tube-like design with a tube axis and a tube wall that has a first open end for mounting on said sink, in fluid connection with a drain opening of said sink, as well as a second open end for connecting to a drainpipe; a first opening in said tube wall at a first distance from said first open end and a second opening in said tube wall at a second distance from said first open end, which second distance is greater than said first distance; an overflow channel member in fluid connection with said first opening on one side and with said second opening on the other side, thus providing an overflow fluid connection from said first opening to said second opening through said overflow channel member while bypassing at least a portion of said valve body, wherein a portion of said overflow channel member extends beyond said first open end of the valve body in a direction along the tube axis; a first sealing member and a second sealing member, both located inside the valve body, wherein said first sealing member and said second sealing member are moveable relative to each other along said tube axis between an open position, in which there is an open fluid connection from said first open end to said second open end through said valve body along the tube axis, and a closed position, in which said fluid con- nection is blocked, said first sealing member having at least one overflow open- ing which is part of said overflow fluid connection from said first open end to said second open end through said overflow opening and said overflow channel member; wherein a cross section of said overflow channel member, at least in a connection region comprising at least one of said first opening and said second opening in said tube wall, is flat, with a maximum extension in direction along the tube axis being smaller than a maximum extension in a direction across the tube axis.

According to said other aspect of the invention, a sink, in particular a kitchen sink, has at least one bowl with a bottom wall and a circumferential side wall, at least one outlet opening located in said bottom wall, and an overflow system according to said first aspect of the invention, wherein the valve body of said overflow system is mounted on said sink underneath said bottom wall at said outlet opening, said first open end of the valve body of said overflow system being in fluid connection with said outlet opening.

Owing to said cross section of said overflow channel, at least in a connection region comprising at least one of said first opening and said second opening in said tube wall, being flat, with a maximum extension in direction along the tube axis being smaller than a maximum extension in a direction across the tube ax- is, the overflow system according to the present invention can achieve a low overall construction height, which facilitates installation of the overflow system underneath a sink, in particular in an installation state thereof. Nevertheless, owing to the relatively large maximum extension in direction across the tube ax- is, it can be ensured that an achievable drain rate is sufficiently high, e. g. of the order of twelve liters per minute (12 l/min).

In order to further reduce an overall construction height of the inventive overflow system, in a further embodiment thereof said overflow channel number compris- es a drain portion connected to said first opening and a return portion connected to said second opening, both having a flat cross section, wherein said drain por- tion and said return portion at least partly extend in parallel.

Pursuing this idea even further, in another preferred embodiment of the overflow system according to the present invention said drain portion and said return por- tion at least partly extend at a common circumferential position with respect to the tube axis, but at different axial positions with respect to the tube axis. This leads to a stacked configuration of the overflow channel number, at least as far as said drain portion and said return portion are concerned, which can lead to a very compact design and - in connection with said flat cross section - still main- tains a small construction height.

Preferably, in another embodiment of the overflow system in accordance with the present invention, said maximum extension in direction along the tube axis is smaller than said maximum extension in direction across the tube axis by a factor of about 2 to 6, preferably about 3 to 5, most preferably about 4.

The applicant has found that a most preferred embodiment of the overflow sys- tem in accordance with the present invention comprises said cross section of said overflow channel member being essentially rectangular in shape. This comprises rectangular cross sections with rounded corners.

According to another aspect, an overflow system which comprises at least the features of the preamble of patent claim 1 further comprises, in said overflow channel member, a vent portion separate from said overflow fluid connection, which vent portion defines a fluid connection between said second open end and the environment, also in said closed position of the first sealing member and the second sealing member. According to this aspect of the invention, which could be regarded as a separate invention in respect of the subject-matter of claim 1 , said vent portion ensures a safe functioning of the overflow system and helps to achieve higher drain rates, e. g. of the order of 12 l/min. Said vent por- tion prevents air from getting trapped inside the overflow system, which could lead to a reduction of the drain rate.

In another embodiment of the overflow system comprising a vent portion, said vent portion opens to the environment in vicinity to said portion of said overflow channel member which extends beyond said first open end of the valve body in a direction along the tube axis. Preferably, a valve member is located at a posi- tion where said vent portion opens to the environment. Said valve member func- tions to prevent any water from leaving the system through the vent portion into the environment.

In order to allow adapting an overflow system, having at least the features ac- cording to the preamble of patent claim 1 , to sinks of various forms and sizes, it may be preferred to have an adjusting mechanism for adjusting a sideways ex- tension in direction across the tube axis of said overflow channel member with respect to said valve body. I n general, said overflow channel member takes the form of an angled tube member, a vertical portion (in an installed state) of which should be located just outside a side wall of the sink in question. This can be achieved by means of the above-mentioned adjusting mechanism.

In a preferred embodiment, said adjusting mechanism could be constructed as follows: Said overflow channel member comprises the drain portion connected to said first opening and a return portion connected to said second opening. Both the drain portion and the return portion can be of a flat cross section. Further- more, said drain portion and said return portion can at least partly extend in parallel. The valve body comprises respective extensions at said first opening and at said second opening, which extensions are preferably formed in integral fashion with the valve body. Into said extensions said overflow channel member is adjustably inserted with its drain portion and with its return portion, respec- tively. Obviously, a reversed construction is also possible, wherein said exten- sions are adjustably inserted in the drain portion and in the return portion, re- spectively, of the overflow channel member. In this way, by simply modifying an extent of insertion of the overflow channel member in the extensions of the valve body, or vice versa, said sideways extension can be modified.

In order to achieve safe functioning of the overflow system, it is preferred that a respective sealing member is inserted between said extensions and said por- tions of the overflow channel member. A single, common sealing member can be used for both extensions and portions.

According to a further aspect, an overflow system having at least the features of the preamble of claim 1 may further comprise a waste goblet having a solid por- tion functioning as said first sealing member, which waste goblet presents a plu rality of openings functioning as said at least one overflow opening, which open- ings take the form of slits or slots, a longer axis of which is inclined relative to a radial direction of the valve body. In this way, water streaming through said openings, owing to the described inclination, will produce a streaming pattern that facilitates a draining action of the overflow system.

In addition to said waste goblet, in a further embodiment the overflow system further comprises a strainer basket arranged at a distance from said waste gob- let, wherein said strainer basket and said waste goblet are attached to a com- mon support member, which support member extends along the tube axis of said valve body. In this way, the strainer basket and the waste goblet can be easily moved or displaced together with the single operation. The strainer bas- ket can prevent blocking of the waste goblet, i.e. the at least one overflow open- ing, by solid waste from the sink bowl.

In yet a further embodiment, the overflow system according to the present in- vention further comprises an actuator arrangement having an actuator for dis- placing at least said first sealing member (e. g. the waste goblet) relative to said second sealing member, which can be devised in the form of a gasket ring corn- prised in said valve body, and a control element for actuating said actuator.

In a preferred further embodiment of the overflow system according to the pre- sent invention, said actuator is devised as a lever and said control element comprises a push button or a rotary knob. Preferably, there is a mechanical connection between the activator and the control element, e. g. in the form of at least one connecting rod or a Bowden wire. Especially a control element in the form of a push button may greatly facilitate operation of the overflow system. Purely mechanical or electro-mechanical constructions can be used for said ac- tuator arrangement.

According to another aspect of the invention, there is provided a sink, in particu- lar kitchen sink, having at least one bowl with a bottom wall and a circumferen- tial side wall, at least one outlet opening located in said bottom wall, and an overflow system according to the present invention, wherein: the valve body of said overflow system is mounted on said sink underneath said bottom wall at said outlet opening, said first open end of the valve body of said overflow sys- tem being in fluid connection with said outlet opening.

Further features and advantages of the present invention will now be described in connection with exemplary embodiments thereof with relation to the drawings.

Figure 1 shows a vertical section through a sink according to the present invention with an overflow system according to the present invention;

Figure 2 is a different sectional view of the overflow system ac- cording to Fig. 1 ;

Figure 3 is a prospective view of the overflow system according to

Fig. 1 ;

Figure 4 is an exploded view of the overflow system according to

Fig. 1 ;

Figure 5 shows the overflow channel member of an overflow sys- tem according to the present invention in assembled and disassembled states; and

Figure 6 shows a comparison of an overflow system according to the present invention with a prior art (similar to

EP 2 71 1 475 A1 ) overflow system. In Fig. 1 , a sink as comprised in the present invention is denoted by means of reference numeral 1 . Said sink 1 can - without limitation - be devised as a kitchen sink of rectangular shape, and it is preferably made of metal. It compris- es a bowl 2 with a bottom wall 3 and a circumferential side wall 4. At least one outlet opening 3a is located in said bottom wall 3. A circumferential rim 5 is lo- cated at an upper edge of said bowl 2 around an outside thereof, as can be readily seen from the enlarged detailed view in Fig. 1 . Said rim 5 extends out- wardly from said side wall 4 by an extent. The rim 5 can have a polished upper face 5a, while said circumferential side wall 4 can have a brushed surface 4a at least on an inside of said bowl 2.

Underneath bottom wall 3 of sink 1 , and partly extending through-outlet open- ing 3a into an interior of sink bowl 2, there is provided a valve body 6, which valve body 6 is mounted on the sink 1 . Valve body 6 forms part of an overflow system for the sink 1 , which overflow system is - as a whole - denoted by refer- ence numeral 7. Valve body 6 has an overall tube-like design with a tube axis A and a tube wall 6a. Tube-like valve body 6 has a first open end 6b, at which it is mounted on sink 1 , in fluid connection with a drain opening (outlet opening 3a) of the sink 1 . Further, tube-like valve body 6 has a second open end 6c for con- necting to a drain pipe (not shown). Further, there are two more openings in said tube wall 6a, i. e. a first opening 6d located slightly below open end 6b and a second opening 6e located farther below the first open end 6b. In Fig. 1 , a first distance between the first open end 6b and said first opening 6d is denoted by reference numeral d 1 , whereas a second distance between said second opening 6e and the first open end 6b is denoted by reference numeral d2, with d2 > d 1 .

The overflow system 7 further comprises an overflow channel member 8, which is devised in form of an angled tube element. It is in fluid connection with first opening 6d on the one side and with second opening 6e on the other side and thus provides an overflow fluid connection from said first opening 6d to said second opening 6e through overflow channel member 8, bypassing at least a portion of valve body 6. Portion of overflow channel member 8 extends beyond first open end 6b of valve body 6 in a direction along the tube axis A. This por- tion essentially corresponds to the vertical portion of overflow channel member 8 as depicted in Fig. 1 . Overflow system 7 further comprises first sealing mem- ber, in the form of a solid portion 9a of a waste goblet 9, and a second sealing member 10, which second sealing member 10 is devised in the form of a ring gasket lodged in a circular groove 6f of valve body 6. First sealing member 9a, i. e. past of waste goblet 9, and second sealing member 10 are moveable or dis- placeable relative to each other along tube axis A between an opened position , in which there is an open fluid connection from the first open end 6b to the sec- ond open end 6c straight or directly through valve body 6 along tube axis A, and a closed position, as shown in Fig. 1 , in which said fluid connection is blocked. Relative displacements of first sealing member 9a and second sealing member 10 can be achieved by means of an actuator in the form of a lever 1 1 , which lever 1 1 is articulated on the valve body 6, as shown. Waste goblet 9 is attached to a central support member 12 or support rod extending along tube axis A. An upward movement (not shown) of lever 1 1 will impart an upward movement on support member 12, thus lifting waste goblet 9 together with first sealing mem- ber 9a while opening said fluid connection. Further, first sealing member 9a (i. e. , waste goblet 9) has at least one overflow opening in the form of a plurality of slits or slots 9b which are arranged in a circumferential wall 9c of waste gob- let 9. These slits or slots 9b are part of said overflow fluid connection from the first open end 6b to the second open end 6c through said at least one overflow opening 9b and said overflow channel member 8 via first opening 6d and second opening 6e. Slits or slots 9b are inclined relative to a radial direction in respect of tube axis A, as will become apparent from Fig. 3.

Overflow channel member 8 comprises a drain portion 8a in fluid connection with first opening 6b and a return portion 8b in fluid connection with second opening 6e. Drain portion 8a and return portion 8b have a fluid connection at reference numeral 8c, as known per se. Reference numeral 8d denotes an end cap for closing off overflow channel member 8 at reference numeral 8c. End cap 8d comprises a valve member 8e, the functioning of which will be described far- ther below.

Above waste goblet 9 and attached to same support member 12, there is pro- vided a strainer basket 13 as known from conventional sink arrangements.

Strainer basket 13 is provided to hold back solid waste in order to prevent block- ing of the drain pipe. Further, valve body 6 has two extensions 8g, 8h which surround and extend from first opening 6d and second opening 6e, respectively. Overflow channel member 8 is adjustably inserted with a free end of its drain portion 8a into ex- tension 6g, while a free end of return portion 8b is adjustably inserted in exten- sion 6h. A sealing member 14 is provided to ensure a watertight connection be- tween extensions 6h, 6g and said portions 8a, 8b of overflow channel member 8. Extensions 6g, 6h are formed integrally with rest of valve body 6. This provides an adjusting mechanism for adjusting a sideways extension in direction essen- tially across tube axis A of said overflow channel member 8 with respect to valve body 6. By simply pulling out overflow channel member 8 from said exten- sions 6g, 6h, or by further insertion, said sideways extension can be changed as a function of the dimensions of sink 1 .

Fig. 2 shows the embodiment of Fig. 1 with a slightly different section plane. In parallel with return portion 8b (cf. Fig. 1 ), there is provided a vent portion 8f ex- tending all the way from valve body 6 to (and through) end cap 8d, for prevent- ing blocking of the overflow due to trapping of air bubbles or the like. Vent por- tion 8f has a free (protruding) open end 8f for insertion into valve body 6 at opening 6e. Vent portion 8f will be further described in connection with Fig. 5.

Referring now to Fig. 3, the overflow system 7 according to the present inven- tion is shown in prospective view. Reference numeral 15 is used to designate a control element for activating actuator (lever) 1 1 , as shown in Fig. 1 . Together, said actuator 1 1 and said control element 15, which takes the form of a Bowden wire 15a inserted in a flexible tube 15b (cf. Fig. 2), form an actuator arrange- ment, wherein said control element 15 may further comprise a push button or a rotary knob (not shown), connected to Bowden wire 15a. At reference numeral 8e’ there is shown an opening to the environment 16 of said vent portion, which will be explained in detail farther below.

Fig. 4 shows the overflow system 7 of Fig. 2 in disassembled (exploded) state. The same reference numerals are used as in Fig. 1 or 2. Reference numeral 13 designates the strainer basket which is connected via center screw 17 with thread insert 18. Reference numeral 9 denotes the waste goblet, while reference numerals 18 and 19 denotes a gasket and a waste kit gasket, respectively. Ref- erence numeral 10 corresponds to Fig. 1 , as thus reference numeral 6 which designates the valve body. Reference numeral 20 is a thread insert, and refer- ence numeral 21 is an adapter ring. Reference numeral 14 designates the seal- ing member mentioned earlier in connection with Fig. 1 . The overflow channel member is designated by reference numeral 8 as before. Actuator arrangement 15 is shown in detailed fashion including Bowden wire 15a, flexible tube 15b and various further elements including O-rings 15c, closing axle 15d, sealing washer 15e, screw 15f, hood 15g and further screws 15h. Reference numeral 15i de- notes a waste kit key.

Fig. 5 shows the overflow channel member 8 of Fig. 1 with drain portion 8a and return portion 8b, both of which are subdivided into two parallel portions 8a’, 8a” and 8b’, 8b”, respectively. Located between drain portions 8b’, 8b” is said vent portion 8f mentioned earlier. Vent portion 8f is in fluid connection with an interior of valve body 6 via protruding end 8f for preventing build-up of air bubbles with might deteriorate drain functioning. Valve member 8e as shown in Fig. 1 closes off vent portion 8f so that no liquid can escape into the environment. In Fig. 5, overflow channel member 8 is shown in disassembled state (left) and assembled state (right). The connection between end cap 8d and the rest of overflow chan- nel member 8 can be achieved by mirror welding at reference numerals 22. As can be further gathered from Fig. 5, a maximum extension of drain portion 8a in a direction across axis A (cf. Fig. 1 ) is denoted mE1 and is greater than maxi- mum extension mE2 in a direction along axis A (cf. Fig. 1 ). This also holds for return portion 8b - irrespective of subdivision into parallel portions 8a’, 8a” and 8b’, 8b”, respectively. Preferably mE1 /mE2 is about 4, without restriction to this particular value.

Fig. 6 shows a comparison between the overflow system 7 according to the pre- sent invention (on the right-hand side) and a prior art overflow system (analog to, e.g., EP 2 71 1 475 A1 ; on the left-hand side). The prior art system has an overflow channel member 8’ which has an opening 8” which corresponds to an opening (not shown) in the sink which is to be fitted with the overflow system in question.

As can be gathered from Fig. 6, a construction height or vertical height of the new overflow system 7 corresponds to overall height of the prior art system, said height being denoted by reference numeral h. In this way, while providing a hidden overflow, which is an esthetical advantage, the new overflow system 7 does not require more space than conventional overflow systems.

Claims

1 . An overflow system (7) for a sink (1 ), comprising:

a valve body (6) to be mounted on said sink (1 ), which valve body (6) is of overall tube-like design with a tube axis (A) and a tube wall (6a) that has a first open end (6b) for mounting on said sink (1 ), in fluid connection with a drain opening of said sink (1 ), as well as a second open end (6c) for con- necting to a drainpipe;

a first opening (6d) in said tube wall (6a) at a first distance (d 1 ) from said first open end (6b) and a second opening (6e) in said tube wall (6a) at a second distance (d2) from said first open end (6b), which second distance (d2) is greater than said first distance (d 1 );

an overflow channel member (8) in fluid connection with said first opening (6d) on one side and with said second opening (6e) on the other side, thus providing an overflow fluid connection from said first opening (6d) to said second opening (6e) through said overflow channel member (8) while by- passing at least a portion of said valve body (6), wherein a portion of said overflow channel member (8) extends beyond said first open end (6b) of the valve body (6) in a direction along the tube axis (A);

a first sealing member (9a) and a second sealing member (10), both located inside the valve body (6), wherein said first sealing member (9a) and said second sealing member (10) are moveable relative to each other along said tube axis (A) between an open position, in which there is an open fluid con- nection from said first open end (6b) to said second open end (6c) through said valve body (6) along the tube axis (A), and a closed position, in which said fluid connection is blocked, said first sealing member (9a) having at least one overflow opening (9b) which is part of said overflow fluid connec- tion from said first open end (6b) to said second open end (6c) through said overflow opening (9b) and said overflow channel member (8);

characterized in that

a cross section of said overflow channel member (8), at least in a connection region comprising at least one of said first opening (6d) and said second opening (6e) in said tube wall (6a), is flat, with a maximum extension (mE2) in direction along the tube axis (A) being smaller than a maximum extension (mE1 ) in a direction across the tube axis (A).

2. The overflow system (7) of claim 1 , further comprising:

in said overflow channel member (8) a drain portion (8a) connected to said first opening (6d) and a return portion (8b) connected to said second opening (6e), both of flat cross section, wherein said drain portion (8a) and said re- turn portion (8b) at least partly extend in parallel.

3. The overflow system (7) of claim 2, wherein:

said drain portion (8a) and said return portion (8b) at least partly extend at a common circumferential position with respect to the tube axis (A), but at dif- ferent axial positions with respect to the tube axis (A).

4. The overflow system (7) of claim 1 , wherein:

said maximum extension (mE2) in direction along the tube axis (A) is smaller than said maximum extension (mE1 ) in direction across the tube axis (A) by a factor of about 2 to 6, preferably about 3 to 5, most preferably about 4.

5. The overflow system (7) of claim 1 , wherein:

said cross section of said overflow channel member (8) is essentially rectan- gular in shape.

6. The overflow system (7) of claim 1 , further comprising:

in said overflow channel member (8) a vent portion (8f) separate from said overflow fluid connection, which vent portion (8f) defines a fluid connection between said second open end (6c) and the environment (), also in said closed position of the first sealing member (9a) and the second sealing member (10).

7. The overflow system (7) of claim 6, wherein:

said vent portion (8f) opens to the environment (16) in vicinity to said portion of said overflow channel member (8) which extends beyond said first open end (6b) of the valve body (6) in a direction along the tube axis (A), prefera- bly a valve member (8e) being located where said vent portion (8f) opens to the environment (16).

8. The overflow system (7) of claim 1 , further comprising:

an adjusting mechanism for adjusting a sideways extension in direction across the tube axis (A) of said overflow channel member (8) with respect to said valve body (6).

9. The overflow system (7) of claim 8, wherein:

said overflow channel member (8) comprises a drain portion (8a) connected to said first opening (6d) and a return portion (8b) connected to said second opening (6e), preferably both of flat cross section , said drain portion (8a) and said return portion (8b) at least partly extending in parallel, wherein the valve body (6) comprises respective extensions (6g, 6h) at said first opening (6d) and at said second opening (6e), into which extensions (6g, 6h) said over- flow channel member (8) is adjustably inserted with its drain portion (8a) and with its return portion (8b), respectively, or vice versa.

10. The overflow system (7) of claim 9, wherein:

a respective sealing member (14) is inserted between said extensions (6g, 6h) and said portions (8a, 8b) of the overflow channel member (8).

1 1 . The overflow system (7) of claim 1 , further comprising:

a waste goblet (9) having a solid portion functioning as said first sealing member (9a), which waste goblet (9) presents a plurality of openings (9b) functioning as said at least one overflow opening (9b), which openings (9b) take the form of slits, a longer axis of which is inclined relative to a radial di- rection of the valve body (6).

12. The overflow system (7) of claim 1 1 , further comprising:

a strainer basket (13) arranged at a distance from said waste goblet (9), wherein said strainer basket (13) and said waste goblet (9) are attached to a common support member (12) extending along the tube axis (A) of said valve body (6).

13. The overflow system (7) of claim 1 , further comprising:

an actuator arrangement having an actuator (1 1 ) for displacing at least said first sealing member (9a) relative to said second sealing member (10) and a control element (15) for actuating said actuator (1 1 ).

14. The overflow system (7) of claim 13, wherein:

said actuator (1 1 ) is devised as a lever (1 1 ) and said control element com- prises a push button or a rotary knob.

15. A sink (1 ), in particular kitchen sink, having at least one bowl (2) with a bot- tom wall (3) and a circumferential side wall (4), at least one outlet opening (3a) located in said bottom wall (3), and an overflow system (7) according to any one of claims 1 through 14, wherein:

the valve body (6) of said overflow system (7) is mounted on said sink (1 ) underneath said bottom wall (3) at said outlet opening (3a), said first open end (6b) of the valve body (6) of said overflow system (7) being in fluid con- nection with said outlet opening (3a).