DE20000729U1 - Drain plugs for drain fittings - Google Patents

Abstract

The central portion of the plug (16) is slightly mushroom-shaped so that it may be used as a handgrip for lifting up the plug. The central portion is surrounded by a deep-drawn skirt (7) with apertures (20) through which the waste water can flow. There is a sealing ring (10) around the central portion of the plug which presses against the rim of the drain opening, which lies in a bowl-shaped depression under the skirt of the plug. The plug has a central shaft (9) which is held in a bearing (22).

Description

PATENT ATTORNEYS DIPL.-ING. R. LEMCKE DR.-ING. H. J. BROMMER DIPL.-ING. F. PETERSEN DIPL.-ING. D. BLUMENROHR

BISMARCKSTRASSE 16 76133 KARLSRUHE , TELEPHONE (07 21) 91 28 00 TELEPHONE (07 21) 2 11 05

15 December 1999 17 888 (A/gr/ko)

NIRO-PLAN AG Baarerstraße 59 CH-6300 Zug

. Drain plugs for drain fittings

PATENT ATTORNEYS .&idigr;.*··* ·· "* DIPL.-ING. R. LEMCKE DR.-ING. H. J. BROMMER DIPL.-ING. F. PETERSEN DIPL.-ING. D. BLUMENROHR

BISMARCKSTRASSE 16 76133 KARLSRUHE

TELEPHONE (07 21) 91 28 00 TELEPHONE (07 21) 2 11 05

15 December 1999 17 888(A/gr/ko)

Description

The invention relates to a drain plug for a drain fitting, in particular a kitchen sink, with a cap, a sealing element and a guide pin aligned parallel to the central axis, wherein both the sealing element and the guide pin are arranged below the top of the cap.

Such drain plugs are used in particular in kitchen sinks to close the drain in the bottom of a sink so that water can collect inside the sink. Dishes or foodstuffs such as salads or fruit can then be easily cleaned in the sink filled with water.

To prevent the drain plug from tipping over, its guide pin is inserted from above into a corresponding guide sleeve on the drain fitting. A user can often change the vertical position of the drain plug by operating a lever on a device not described in detail here, usually located outside the sink. This moves the drain plug via its guide pin from a sealing position, in which the sealing element closes the drain to prevent the washing water from running out, to an open position that allows the water to flow away. Of course, it is also possible to move the drain plug from the open to the sealing position.

In the prior art, drain plugs are also known in which the cap is basket-shaped with a circular, flat cap.

sink base and an adjoining, curved, upwardly extending cap edge. This cap edge has openings, which will be explained below. Such a drain plug is generally located in a drain that is recessed compared to the rest of the sink base, so that its usually circular outer edge rests against the wall of the drain.

The above-mentioned openings in the edge of the cap allow the drain plug to remain in the drain in both the sealed and open position, as the rinsing water can flow out through the openings in the open position. The cap with these openings also serves as a sieve in which food residues that have collected in the rinsing water can settle. By lifting the drain plug vertically out of the drain, these food residues can be easily disposed of if necessary.

To connect the guide pin to the cap, a pin on the end of the guide pin is usually inserted from the underside of the cap through a central through hole in the cap base. The length of the pin is dimensioned so that a large part of it protrudes from the top of the through hole. The diameter of the pin is smaller than the diameter of the rest of the guide pin, so that a step is formed that rests against the cap base from below. A fixing cap is then attached to the end of the pin protruding from the top to fix the guide pin axially, for example by pressure welding.

As far as the fastening of the sealing element is concerned, it is known to provide a fixing disk which has a circumferential annular groove into which an annular sealing element can be inserted. The fixing disk is in turn fastened to the underside of the cap base. For this purpose, the fixing disk, just like the cap base, has a through hole corresponding to the guide pin pin, which is penetrated by the pin before it is inserted through the through hole.

The axial fixation of the three parts, i.e. the cap, the guide pin and the fixing disc, is also achieved here by a fixing cap connected to the guide pin pin by pressure welding.

As can be seen from the above, the disadvantage of the drain plugs known in the state of the art is that they are relatively complex to manufacture. At least five individual elements must therefore first be manufactured (the cap, the guide pin, the fixing ring, the sealing ring and the fixing cap), which then have to be put together and welded.

Furthermore, it is unfortunate that gaps appear on the contact surfaces of the components, which are usually made of metal, in which moisture can accumulate, promoting or starting corrosion processes. These gaps appear between the underside of the fixing cap and the top of the cap base, between the underside of the cap base and the fixing ring and finally between the fixing ring and the guide pin.

Due to the moisture, these gaps naturally also encourage the growth of bacteria, which are often present during the cleaning processes carried out in the sink.

Since the gaps are now also comparatively narrow, they are difficult to access when cleaning the drain plug, so that the above effects can hardly be prevented.

The present invention is therefore based on the object of avoiding the described disadvantages of the drain plugs known in the prior art, in particular to simplify the connection of the guide pin and the sealing element to the cap, so that in particular the number of gaps which are difficult to clean and in which bacteria or moisture can collect is reduced.

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This object is achieved according to the invention in that a cup-shaped cap bulge which is open at the bottom and into which the guide pin is captively inserted is formed on the cap.

This creates a cost-effective and easy-to-install connection between the cap and the guide pin. This means that there is no need to provide a central hole in the cap through which a guide pin pin would have to be inserted. Furthermore, no pressure welding is required, so this work step is also eliminated.

Furthermore, the number of hard-to-reach gaps between the individual components is also reduced. Initially, there is only one gap between the guide pin and the inner wall of the cap. As the guide pin is detachably inserted into the cup-shaped cap recess, this results in a clear cleaning advantage over the drain plugs of the state of the art, as the two components can be taken apart for cleaning and completely cleaned separately from one another.

Advantageously, the guide pin is held in the cap recess by pressure exerted by the inner wall of the cap. The guide pin is therefore manufactured with an oversize compared to the smallest inner diameter of the cap recess and is pressed into it, which represents a simple, cost-effective connection method.

However, it is also advantageous to hold the guide pin in the cap recess using locking devices in order to ensure that it is as secure as possible against loss.

It has also proven to be useful that the guide pin is held in the cap recess by a clamping element. An additional clamping element is therefore provided, via which the guide pin is indirectly attached to the cap. This additional clamping element

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opens up the possibility of selecting the diameter of the guide pin independently of the inner diameter of the cap recess. In general, it is advisable to select the inner diameter of the cap recess as large as possible so that the cap recess can be used optimally by a user as a handle button by which the drain plug can be grasped to lift it out of the drain.

The guide pin diameter, on the other hand, should be kept as small as possible so that the effective cross section of the drain fitting through which the waste water flows is as large as possible. However, since the guide pin sits in the guide sleeve of the drain fitting, it ultimately reduces the effective cross section.

The clamping element mentioned makes it possible to meet these two contradictory requirements by compensating for the different dimensions of the guide pin and the cap recess.

As far as the connection between the guide pin and the clamping element is concerned, it is advantageous if the guide pin is pressed into the clamping element, as this is a simple and cost-effective connection option.

However, it is just as advantageous if the guide pin has a screw head-like attachment at one end, with which it sits in a stepped hole in the clamping element. Then the guide pin can simply be inserted into the stepped hole in the clamping element from above during assembly.

As far as the connection of the clamping element with the cap recess is concerned, it is advantageous if the clamping element is pressed captively into the cap recess, since this connection is then also very simple and cost-effective.

The clamping element can also be locked into the cap recess using a locking mechanism. It is particularly advantageous that the clamping element and cap can be assembled later, i.e. in some cases even by the customer.

As far as the shape of the clamping element is concerned, it can advantageously be designed in the shape of a disk with a central bore for receiving the guide pin. This is particularly advantageous if the wall of the cap recess is essentially hollow-cylindrical, so that the disk-shaped clamping element rests against the inner wall of the cap recess over its entire circumference, which ensures optimal radial fixation of the clamping element.

The top of the disc-shaped clamping element can advantageously have a circumferential annular groove. This annular groove allows a certain flexibility of the raised edge of the clamping element, which can initially make it easier to insert the clamping element into the cap recess.

The clamping element is advantageously made of plastic, so that its comparatively low weight means that it only increases the overall mass of the drain plug insignificantly. Furthermore, a clamping element made of plastic is not susceptible to corrosion and is also easy to manufacture as an injection-molded part.

As far as the sealing element is concerned, it is advantageous if it is arranged on the clamping element. In particular, if the clamping element is made of plastic, it is expedient to provide devices on the clamping element by means of which the sealing element is held there.

It is particularly advantageous if the sealing element is inserted into a corresponding annular groove of the clamping element. Then

Commercially available sealing rings made of rubber or elastomer can be used.

As far as the annular groove is concerned, it is advantageous if it is recessed in the outer circumference of an annular strip arranged at the bottom of the clamping element.

In a special embodiment, the wall of the cap recess has at least one recess on the outside directed towards the central axis for gripping. A user who wants to lift or transport the drain plug can easily grasp the drain plug at this recess in the side wall. In particular, when the drain plug is wet, which is naturally often the case with sinks, this recess enables the plug to be gripped without slipping.

The indentation can advantageously run along the entire circumference of the cap bulge. This creates a rotationally symmetrical indentation that allows the user to grasp the plug at the indentation with one hand without having to look directly at it.

Furthermore, the cap with the bulge formed on it can advantageously be deep-drawn in one piece, so that welding or similar joining techniques are avoided.

Since the area around the drain plug is very humid, especially in kitchen sinks, it is advantageous if the cap is made of corrosion-resistant stainless steel.

Further advantages and features of the invention will become apparent from the following description of an embodiment.

Fig. 1 is a plan view of a sink drain of a kitchen sink;

Fig. 2 is a cross-section of the sink drain of Fig. 1 along the line l-l with a drain plug inserted into the drain;

Fig. 3 a cross-section of the drain plug inserted into the drain with the drain fitting arranged below the sink;

Fig. 4 is an exploded view of the drain plug.

Figure 1 shows a top view of a circular sink drain 1 of a kitchen sink. Since the sink drain, like the sink itself, is a common component, it will only be described briefly below for the sake of clarity.

The sink drain 1 is formed directly as a circular, downward-facing recess in the sink base 2 of the kitchen sink. In the middle of the sink drain 1 there is a circular outlet area 3 which has a central bore 4. Furthermore, in the edge area of the circular outlet area 3 there are six trapezoidal outlets 5 which surround the central bore 4 in a rotationally symmetrical manner.

Figure 2 shows the cross section of the sink drain 1 along the line l-l. The axis II represents an axis of rotational symmetry. The depression within the sink base 2, which forms the sink drain 1, can be clearly seen. Furthermore, two of the trapezoidal outlets 5 are visible here, in the middle of which the central bore 4 is arranged.

In addition, Figure 2 shows a drain plug 6 which consists of a cap 7 made of corrosion-resistant stainless steel, to which a guide pin 9 and a sealing element are attached via a clamping element 8 made of plastic.

The guide pin 9 is inserted into a guide sleeve 11 of a drain fitting 12, which is shown in Figure 3. The guide sleeve 11 is in turn inserted from above into the central bore 4.

The drain plug is in a sealing position in Figure 2, i.e. flushing water running down the sink drain 1 is prevented by the sealing element 10 - here an elastomer sealing ring - from flowing from the trapezoidal outlets 5 into the drain fitting 12, since the sealing ring 10 rests in the edge area of the outlet area 3 and effectively seals it.

The drain plug 6, like the sink drain 1, is rotationally symmetrical to the rotation axis II, so that the one-piece deep-drawn cap 7 of the drain plug has a circular outer circumference when viewed from above. The pot-shaped cap bulge 13 with a top side and a side wall 15 can be clearly seen. The open end of the cap bulge points downwards, i.e. towards the sink drain 1. The drain plug 6 can be gripped from above at this cap bulge 13 and lifted vertically out of the guide sleeve 11. To make this gripping easier, a recess for engagement 16 directed towards the rotation axis II is provided on the outside of the side wall 15 of the cap bulge 13. This recess for engagement 16 runs along the entire circumference of the cap bulge 13.

The clamping element 8, which is disk-shaped, has an annular groove 17 on its top side, which increases its flexibility. Furthermore, there is a stepped bore 23 in the center of the clamping element 8. When assembling the drain plug 6, the guide pin 9 is inserted into the stepped bore 23 from above until a screw head-like projection 18 of the guide pin 9 comes to rest on the first transverse step of the bore 23. Instead of connecting the guide pin to the clamping element 8 via this stepped bore 23, it is of course also conceivable that the guide pin 9 is pressed into the clamping element 8.

On the underside of the clamping element 8 there is a circumferential ring strip 19, on the outside of which an annular groove is recessed into which the sealing ring 10 is inserted. For this purpose, the height and width of the annular groove must of course correspond to the sealing ring 10. The ring strip 19 is advantageously connected in one piece to the clamping element 8.

Figure 3 shows the drain plug 6 in section along the line l-l of Figure 1. The drain fitting 12 is also shown, which is arranged below the sink drain 1. The basket shape of the cap 7 of the drain plug 6 with the pot-shaped cap bulge 13 rising up in the center of the cap can be clearly seen here. It can also be clearly seen that the cap 7 is a strainer basket which has openings 20 in its peripheral edge area which allow rinsing water to pass through them.

If, for example, the guide pin 9 is raised vertically by a device not further described here, the sealing ring 10 is no longer in a sealing position, so that water passing through the openings 20 flows directly through the trapezoidal outlets 5 into the drain fitting 12.

Also clearly visible here is the guide sleeve 11, which is inserted into the central hole 4 of the outlet area 3 from above during assembly and rests on its edge with a collar. The drain fitting 12 is then screwed onto this sleeve, which has an external thread 22 at its lower end. Not explained in more detail here are the molded seals 21, which seal the individual components of the drain fitting 12 against each other or seal the drain fitting against the sink drain 1.

Figure 4 shows an exploded view of the drain plug 6. During assembly, the sealing ring 10 is first inserted into the ring groove of the clamping element 8. The guide pin 9 is then inserted into the clamping element 8 via the stepped bore 23 until the screw

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head-like projection 18 of the guide element 9 comes to rest on the transverse step of the bore 23.

The combination of clamping element 8 and guide pin 9 as well as the sealing ring 10 is then pressed into the cup-shaped cap recess 13 of the cap 7 of the drain plug 6.

Only faintly visible is a circumferential recess 24 of the clamping element 8, into which a corresponding curvature of the side wall 15 of the cap bulge 13 engages.

Claims (17)

1. Drain plug ( 6 ) for a drain fitting ( 12 ), in particular a kitchen sink, with a cap ( 7 ), a sealing element ( 10 ) and a guide pin ( 9 ) aligned parallel to the central axis (II), wherein both the sealing element ( 10 ) and the guide pin ( 9 ) are arranged below the top side ( 14 ) of the cap, characterized in that a downwardly open pot-shaped cap bulge ( 13 ) is formed on the cap, into which the guide pin is inserted. 2. Drain plug according to claim 1, characterized in that the guide pin ( 9 ) is held in the cap recess ( 13 ) by pressing. 3. Drain plug according to claim 1, characterized in that the guide pin ( 9 ) is held in the cap recess ( 13 ) by locking means. 4. Drain plug according to claim 1, characterized in that the guide pin ( 9 ) is held in the cap recess ( 13 ) via a clamping element ( 8 ). 5. Drain plug according to claim 4, characterized in that the guide pin ( 9 ) is pressed into the clamping element ( 8 ). 6. Drain plug according to claim 4, characterized in that the guide pin ( 9 ) has a screw head-like projection ( 18 ) with which it sits in a stepped bore ( 23 ) of the clamping element ( 8 ). 7. Drain plug according to claim 4, characterized in that the clamping element ( 8 ) is pressed captively into the cap recess ( 13 ). 8. Drain plug according to claim 4, characterized in that the clamping element ( 8 ) is captively locked in the cap recess ( 13 ) by locking means. 9. Drain plug according to claim 4, characterized in that the clamping element ( 8 ) is disc-shaped with a central bore ( 23 ) for receiving the guide pin. 10. Drain plug according to claim 9, characterized in that the upper side of the disc-shaped clamping element ( 8 ) has a circumferential annular groove ( 17 ). 11. Drain plug according to claim 4, characterized in that the clamping element ( 8 ) consists of plastic. 12. Drain plug according to claim 4, characterized in that the sealing element ( 10 ) is arranged on the clamping element ( 8 ). 13. Drain plug according to claim 4, characterized in that the sealing element ( 10 ) is inserted into a corresponding annular groove of the clamping element ( 8 ). 14. Drain plug according to claim 13, characterized in that the annular groove is recessed in the outer circumference of an annular strip ( 19 ) arranged on the bottom of the clamping element ( 8 ). 15. Drain plug according to claim 1, characterized in that the side wall ( 15 ) of the cap bulge ( 13 ) has on the outside at least one recess for engagement ( 16 ) directed towards the central axis (II). 16. Drain plug according to claim 15, characterized in that the indentation ( 16 ) runs along the entire circumference of the cap bulge ( 13 ). 17. Drain plug according to claim 1, characterized in that the cap ( 7 ) is deep-drawn in one piece.