WO1985000047A1

WO1985000047A1 - Water flushing tank for wc

Info

Publication number: WO1985000047A1
Application number: PCT/DE1984/000134
Authority: WO
Inventors: Konrad Altmann
Original assignee: Konrad Altmann
Priority date: 1983-06-14
Filing date: 1984-06-14
Publication date: 1985-01-03
Also published as: EP0145773A1; AU3100684A

Abstract

The water flushing tank for WC is provided with a predetermined partial emptying and a total emptying (two step flushing). The partial emptying or discharge is effected by a float (25) which is arranged at mid-height of the connection element (22) connecting the lever mechanism (35, 36) provided for the actuation and the sealing body (23). A special actuation of the lever mechanism is provided to effect a complete discharge. Simultaneously, the float for the inlet valve is further operated by permanent magnets so as to render the inlet speed totally independent with respect to the water level. This is obtained by having the float held at the bottom by the attraction force of the two permanent magnets until, at a certain filling height, the vertical thrust is sufficient to separate the magnets.

Description

W C - S p u l k a s t e n

For the toilet flushing, liquid containers with automatically controlled inflow and outflow valves are required. The control of the inflow valve is usually carried out with the aid of a float attached to a lever, which is gradually raised as the liquid level rises and closes the inflow valve at a certain filling level. The emptying takes place with the help of a suction bell or a drain valve at the bottom of the container in connection with a floating body.

The control of the inflow valve just described does not ideally serve its purpose.

Since the inflow valve is closed proportionally to the water level with the aid of the float, the filling speed is greatly reduced towards the end of the filling process. In addition to extending the filling time, this has further negative effects: disturbing noises, blockage of the inflow valve by foreign particles carried in the water, erosion of the seal of the inflow valve.

These disadvantages could be all or the greatest

Partially eliminated by an inflow valve coupled to an integral controller, d. H. by a control mechanism that leaves the inflow valve fully open to the desired level and then closes in a relatively short time. A series of efforts that have been undertaken in this direction for a long time shows that an integral controller can only be implemented very imperfectly by using buoyancy forces alone. Implementation with the aid of an electrical control circuit is ruled out because of the effort involved and the risk of accidents.

Are essential for the drain valve satisfactory executions known. However, these are unsuitable to easily solve the interesting task of draining two different, predetermined amounts of water from the cistern. The proposed solutions are based in part on the fact that the container is divided or that two drain valves are provided. However, such methods are too complex and also prone to failure. Since the task ultimately pursues the purpose of saving, one can only speak of a satisfactory solution if this is achieved in a very simple way.

The invention is therefore based on the object of creating a toilet cistern with control mechanisms of a simple design both for the inlet and for the outlet.

This object is achieved with a toilet cistern, as characterized by claim 1. Developments of the invention are described in the subclaims.

A surprisingly simple and reliable

Realization of an integral controller for the inflow valve is possible according to the invention by the additional control of the float with the help of permanent magnets; this takes advantage of the fact that a permanent magnet can be used to create a mechanical connection between two parts, which is released under a defined force, in our case the buoyancy of the swimmer.

This property of permanent magnets can also be used to control the cistern drain valve. Other options for controlling the drain valve result from the use of a mechanical locking member or using fluid mechanical forces, expedient in connection with weight and / or buoyancy forces.

By combining the control of the drain valve just indicated with the additional control by a float arranged in the middle water level according to the amount of water to be dispensed, the task can also be solved in a surprisingly simple manner, from the container of choice two different, predetermined amounts of water with the help of a single valve to drain off.

The invention is explained in more detail below in exemplary embodiments with reference to the attached drawings,

1 schematically shows the implementation of the control of the inflow valve in a first embodiment,

Fig. 2 shows schematically the implementation of the control of

Inflow valve in a second embodiment,

3 shows schematically the implementation of the control of the drain valve for the delivery of two different amounts of water,

Fig. 4 shows a detail of Fig. 3 from the perspective of

Arrows IV - IV. Fig. 5 shows schematically the implementation of the control of the drain valve for the delivery of two different amounts of water in a second embodiment, Fig. 6 shows the implementation of the control of the drain valve for the delivery of two different amounts of water in a third embodiment, Fig 7 schematically shows the implementation of the control of the drain valve for dispensing two different amounts of water in a fourth embodiment, FIG. 8 schematically shows a variant of the embodiment according to FIG. 7, and Fig. 9 shows schematically the implementation of the control of the drain valve for the delivery of two different amounts of water in a fourth embodiment. The principle and at the same time a simple implementation of the control of the inflow valve of a container 21 with the aid of floats and permanent magnets is shown in FIG. 1. A float 3 and a disk-shaped permanent magnet 6 (e.g. a ferrite) are attached to a vertical rod 2. The rod is guided by means of two arms 4 and 5, which are connected to the housing. Also attached to the upper arm 4 is a second disc-shaped, oppositely polarized permanent magnet 7 which contacts the magnet 6 when the float is in the lower position and the container is empty. The attractive force which the magnets exert on one another in this position is selected such that the magnets, when the container is being filled, are separated against their attractive force by the buoyant force of the float at a predeterminable filling level. Due to the action of the buoyancy force on the float, the rod 2 is then raised until a seal 8 attached to its upper end is pressed against the mouth of the inlet 9 and closes it. Due to the flat design of the magnets, the attractive force they exert on one another rapidly decreases with distance, so that after typically lifting the rod by a few millimeters, the seal 8 is pressed against the inflow tube 9 with practically all of the lifting force. In order to keep the contact surface of the magnets clean, so that a constant magnetic circuit is guaranteed, it is advisable to surround both magnets together with an elastic protective cover 10. If this is not necessary, it should make sense to surround the magnets themselves with corrosion-resistant protective covers, unless magnets made of corrosion-resistant material are used. As can be seen, this simple device ensures that the effective opening of the inflow remains constant during the entire filling process. The filling speed can thus be optimally adjusted and, if necessary, adjusted with an adjusting screw. The filling process can be designed to be very quiet, since there are no loud initial noises. Since the closing process takes place quickly, hissing at the end is almost avoided. There is also no backflow of suspended particles. Nevertheless, the closing process does not occur suddenly because the solenoids are not released abruptly, but continuously over time, albeit quickly.

In order to ensure that the magnets separate particularly precisely at a certain filling level, the floating body can be designed in such a way that its horizontal cross section widens in steps at a certain point 11. The buoyancy force acting on the float then accelerates as soon as the water level reaches this point.

For fine adjustment of the fill level, one of the magnets can, if necessary, be provided with an adjusting screw 12 with which the distance up to which the magnets approach as close as possible can be regulated. To avoid the valve closing too quickly and causing a kickback, fluid mechanical or magnetic damping methods can be used. As an embodiment of a fluidic damping method, it is proposed to design the outer shape of the float in such a way that vortices form and / or masses of water have to be displaced when surfacing. It is further proposed to provide a cavity in the interior of the float which is connected to the exterior by openings and which fills with water when the float is immersed. Through the The amount of water in the cavity increases the effective inert mass of the float, which is effective against the buoyancy force, so that the speed of the buoyancy movement decreases. The resulting dynamic additional mass and the reduction in buoyancy should disappear in the rest position. To ensure this, the openings must be designed so that the water can flow out of the cavity while the float appears, so that in the end position the water level inside and outside the float has the same level. This measure allows the speed of the closing process to be varied over a wide range and thus be adapted to the requirements for kickback safety and silent closing.

This cavity can practically be realized by a cap which is attached to the side of the float.

As an exemplary embodiment of a magnetic damping method, it is proposed that a magnet with a T-shaped cross section be immersed in a toroidal magnet.

A further embodiment of the invention is shown in FIG. 2, parts corresponding to the first embodiment having been given the same reference numerals. Here magnet 6 and float 3 are attached to a lever 13, by means of which the inflow valve is closed at a corresponding filling level. The mode of operation is otherwise analogous to FIG. 1. The magnets can be arranged here to be horizontally displaceable in order to be able to adjust the fill level. In addition, a device 14 for the quiet and spatter-free introduction of the Liquid should be provided in the container. The same applies, of course, to the form of training according to Fig.

The invention can also be implemented in the form of a combination, the embodiments shown in FIGS. 1 and 2 or in other variations.

An embodiment of the use of permanent magnets for controlling the drain valve according to the invention is shown in FIG. 3.

On a tube 22, which also serves as an overflow pipe, a sealing ring 23 is attached below, which serves as a seal for the drain opening 24 of the container 21. In addition, a float 25 and a stop 26 are attached to the tube. The stop 26 presses against an annular floating body 27 which dips into an additional container 28 which has a few, typically 2 to 4, small openings 29 on the underside and is typically on 3 to 4 feet 30. In order to prevent contamination, it is expedient to close the container 28 with a cover 31, however ventilation openings 32 must be provided. In addition, a weight 33 is attached to the tube, which together with the dead weight of the movable valve body slightly exceeds the weight of the amount of liquid displaced by the floating body 27. At the upper end of the tube 22, a bracket 34 is attached, in which two levers 35 and 36 engage, which can rotate about an axis 37. A flat permanent magnet 38 is attached to the lever 36 and contacts a permanent magnet 39 with opposite polarity connected to the housing when the right end of the lever 36 is depressed. The attraction of the magnets in this position, on the one hand, and the weight 33, on the other hand, plus the dead weight of the tube 22, the seal 23 and the float 25 are to be coordinated so that when completely empty leaves. The speed of AbfHeßens from the additional container can be adjusted by appropriate dimensioning of the openings 29 so that the buoyancy force acting on the floating body 27 is reduced so much at the moment when the container is completely emptied that that by the valve body and that Weight 33 caused downward force to separate the magnets and close the valve. This point in time can be finely adjusted by means of the adjusting screw 40.

If the tube 22 is lifted when the container 21 is full, by means of the lever 35, the left end of the lever 36 remains at the bottom thanks to an elongated hole in the bracket 34 and due to the weight of the magnet 38 or another weight distribution along this lever which is to be chosen accordingly. The attraction of the magnets is therefore not effective. The downward pulling force is compensated in this case by the buoyancy force acting on the floating body 25. However, this only acts until the liquid level has dropped approximately to the level of the floating body 25 (lower liquid level in FIG. 3). At this point, the pipe begins to lower, closing the drain opening.

In order to avoid jerky, noisy closing due to a dynamic pressure acting on the seal 23 from above, the seal 23 was designed in a box shape. When the valve is opened, it is pushed into the ring 41, which can be connected to the underside of the container 28 or to the feet 30. The

Box profile is chosen so thick that the top of the sealing rubber does not completely leave the ring 41 even when the valve is closed. This ensures that the liquid between the additional container 28 and the seal 23 remains almost at rest during AbfHeessen, so that the dynamic pressure when closing Containers, the magnets are separated by the downward force of gravity and the opening 24 is closed by the seal 23.

This arrangement has the following function: Is the container completely filled (upper

Fill level in Fig. 3), the buoyancy of the floating body 27 is compensated by the weight 33. On the seal 23 acts the hydrostatic pressure of the liquid, which presses it against the edge of the drain opening. The buoyancy of the

Floating body 25 counteracts this force upwards. In order to prevent the drain from opening or leaking automatically, the floating body 25 must therefore be dimensioned so small that the downward force is not completely compensated for. On the other hand, it is useful to dimension it so large that opening the valve by lifting the tube 22 by means of one of the levers 35 or 36 is possible with little effort.

If the tube 22 is now raised by means of the lever 36 when the container 21 is full, the seal 23 is flowed around on the underside, so that the hydrostatic pressure acting on the top is largely compensated for. Instead, the liquid draining off creates a small suction force. However, this is compensated for by the correspondingly dimensionally attractive force of the magnets 38 and 39, which were brought into contact by the actuation of the lever 36. The drain valve therefore remains open until the container is almost completely empty. If the liquid level drops below the upper edge of the additional container 28, a level difference is formed between the water level in the additional container 28 and that in the main container 21, since the liquid delays the additional container through the openings 29 only acts horizontally on the seal. In addition, the box-shaped design of the seal causes an elastic, noiseless closing of the valve.

As is immediately apparent, the weight 33 also serves its purpose when it is attached to the lever 36. In order to dampen the lowering of the movable valve body, the weight is also proposed

33 movable by means of a stop on the tube

22 to attach and start it with a second stop connected to the housing before the valve closes completely.

Instead of the lever mechanism shown in Fig. 3, of course, any other mechanism can be used, which can be operated in two ways and is characterized in that the holding magnets 38 and 39 are brought into contact only in one of the two types of actuation. A further development of the lever mechanism indicated in FIG. 3 is to operate the two right ends of the levers 35 and 36 together with a rocker. This is shown schematically in FIG. 4. The rocker 42 is rotated about the axis 43. Depending on which side it is pressed down, one of the levers 35, 36 is actuated.

A simplification results if, instead of two permanent magnets 6, 7 or 38, 39, one of the magnets is made of magnetizable material.

As you can see, the control mechanism described is in principle not only suitable for draining a small and a large amount of water. It can be drained by pressing the lever 35 for a longer period any amount in between, which z. B. for cleaning the toilet is an advantage.

A particular advantage results from the combination of the control mechanisms described for the inflow and outflow valve. Since in the control mechanism for the inflow valve, the water always flows in at the same speed, this also applies if only a small amount of water is drained off. In this case, the cistern is refilled much faster than with the conventional float valve, in which the refilling of a small amount takes almost the same time as the filling of the entire tank.

5 shows the use of a mechanical locking element for controlling the drain valve for dispensing two different amounts of water.

On a pipe 1 ', which also serves as an overflow pipe, a sealing ring 2 is attached below. In addition, a floating body 3 is attached to the tube at medium height.

The tube 1 'can be raised by actuating the lever 4', which engages in the bracket 5 'and is rotatable about the axis 6'.

If this happens, the sealing ring 2 is simultaneously raised against the hydrostatic pressure. The drain 7 'then remains open until the level has dropped to the level of the float 3'. The valve then closes due to the suction of the draining water. In order to distinguish the lever 4 from the lever 8 'arranged in parallel in the drawing, this is shown in broken lines in FIG. 1, in the position which it assumes after the right end has been depressed. To the right of the drain, an additional container 9 is attached to the bottom of the cistern, which, like the additional container in FIG. 3, has ventilation holes 10 at the top and openings 11 below, from which the water runs out with a delay when the cistern is emptied. A float 12 'is immersed in the additional container, to which a rod 13 is attached. This rod is passed through a hole 14 'in the lid of the container. Its upper end is movably attached to the right corner of the plate 15, which has the shape of a 90 ° sector. The plate is rotatably supported about the axis 16. B. When the cistern is full, the left, vertical edge of the plate presses due to the buoyancy of the floating body 12 'against the wheel 17' which can rotate about the axis 18 'and is fastened to the left arm of the lever 8' with the help of the latter.

If the lever 8 is now actuated, and thus its left arm is raised, the plate 15 deviates to the left, the circular edge of the plate sliding under the wheel 17 '. This movement is stopped by the fact that the upward movement of the float is limited by the stop 19 when it hits the housing cover. The upper corner of the sector-shaped plate is expediently rounded such that the wheel 17 'can easily roll off. In addition, by a suitable choice of the curvature, it can be achieved that the entire opening process takes place automatically as a result of the buoyancy force generated by the float 12 when the right end of the lever 8 has been depressed by only a few millimeters.

In order to get the float 12 'to emerge as quickly as possible after actuating the lever 8', it is proposed to use roundings so that its flow resistance is as small as possible.

If the process just described has expired, the left end of the lever 8 remains raised until the additional container 9 'has emptied to such an extent that the float 12 sinks. As a result, the plate 15 is also rotated back into its starting position, so that the valve can close. By suitable dimensioning of the openings 11, the time of closing can be determined so that the latter occurs exactly when the cistern is completely empty. In order to reliably ensure the sinking of the float, it is proposed to make the rod 13 correspondingly heavy or to add an additional weight. Since the guide mechanism used in FIG. 3 is omitted here, clamps 20 ′ are provided in FIG. 5 for guiding the tube 1, into which the tube 1 is pressed from the front during manufacture.

In addition to Fig. 3, it is also proposed here that the float 3 is attached to the pipe 1 so that it can be brought into different positions by means of a toothing 21, in which the nose 22 'engages, to the amount of the partial flush adapt for different toilet bowls.

The device just described can be implemented at a very low cost, especially if one manufactures the lower part of the additional container in one piece with the main container, so that the cover only has to be put on during manufacture.

The second method is based on the

Additional containers based solely on the use of fluid mechanical effects. It is explained below using an exemplary embodiment with reference to FIG. 2.

Fig. 6 shows a rod 23 which is rigidly attached to a rotatably mounted axis 24. A weight 25 is also attached to the axle 24 and a cap 26 is attached to its lower end.

This cap, which shields the sealing ring 2 from the right and from above, ensures that the majority of the water flows from the left into the drain 7 '. The result of this is that a force acting from right to left is exerted on the cap during emptying. Immediately after opening the valve, this force is mainly caused by the hydrostatic pressure acting from the right and is approx. 5 N at a filling height of 20 cm. The rod 23 is therefore rotated clockwise immediately after opening, so that its upper end slides under the projection 27 attached to the lever 8. The movement is stopped by the stops 28 ', which are located in FIG. 6 in front of and behind the image plane next to the drain opening 7.

Since the hydrostatic pressure is supplemented by the suction during the discharge, the rod 23 remains in the position reached almost until the cistern is completely emptied. During this time, therefore, the left end of the lever 8 is held in the up position so that the valve cannot close. If the cistern is empty, the suction suddenly abates. The rod 23 'is consequently rotated back into its starting position by the action of the weight 25, which is defined by the stop 29'. At the same time, its upper end moves until it is to the left of the projection 27. When it reached that position so the left arm of the lever 8 lowers, whereby the valve is closed.

In order to avoid frictional forces, a rotatable wheel 30 'is in turn attached to the upper end of the rod 23'. In addition, the corner of the projection 27 'is rounded. This also ensures that the valve opens fully even when the lever 8 'is depressed only a few millimeters. If necessary, however, this detail can be dispensed with.

In order to prevent the sealing ring 2 'from coming into contact with the cap 26' when the tube 1 'emerged, the

A nose 31 'is attached to the tube, which limits the upward movement as soon as it reaches the upper guide bracket 20'. The function of the weight 25 'can also be taken over by a spring, for. B. by a slat made of plastic.

The construction just mentioned has the advantage that the rod 23 'can be made in one piece together with the axis 24' and the weight 25 '(or a spring). When manufacturing the cistern, the axis 24 'can then, for. B. be hung in two projections on the front and rear walls.

5 and 6 can be further simplified if the two actuating levers are combined in one. This is from the following Reason and possible in the following way:

The drain valve can be opened very easily when the cistern is full due to the buoyancy of the floating body 3, which is to be dimensioned accordingly. In addition, the opening takes place automatically when the lever 8 'is only slightly pressed, thanks to the elongated hole in the bracket 5'. Therefore, as shown in FIG. 6, an elastic stop 32 'in the form of a spring or a rubber block is attached under the right end of the lever 8' in such a way that the blockage when tilted up to this

Stop does not engage yet, so a two-stage mode for actuation can be realized in this way.

If the lever is pressed down to the elastic stop 32 ', which requires only a slight tap, partial emptying takes place, but if the pressure on the lever is increased against the resistance of the elastic stop, the blocking snaps after the lever has been tilted further on so that a complete emptying takes place.

In the construction shown in Fig. 7, the short horizontal part of the overflow pipe 40 'is firmly connected to the bottom of the cistern and therefore forms an increase. The confluence of the overflow pipe in the drain is immediately below the drain opening 41. ' On the vertical part of the overflow pipe, a flap 42 'is rotatably fastened, which closes the drain opening. This flap is connected by a rod 46 to an externally rotatable lever 44. A float 3 'is attached to this rod, the position of which in turn can be changed by means of a toothing or a thread. The partial emptying is initiated by turning the lever 44 to the left until it abuts the stop 45, thereby limiting the possible opening angle of the flap. Since the force acting on the flap from above is reduced considerably even with a small rotation, the buoyancy of the float 3 'and the position of the stop 45 can be adjusted so that the float is able to hold the flap open for as long until the water level has dropped to the level of the float. A defined partial emptying is therefore implemented by the float. Should it be necessary to increase the dynamic pressure acting on the plate from the side, it is proposed to bend the left edge of the flap 42 'upwards somewhat, as shown in FIG.

Full emptying is initiated by turning lever 44 to the right. Here the float has the advantage that after a small turn of the lever the flap opens by itself until it hits the stop 47.

The increase in the discharge opening caused by the horizontal part of the overflow pipe can be eliminated if the overflow pipe, as shown in FIG. 8, is inserted into the drain pipe below the nozzle. However, since the flow then changes somewhat, the pressure acting on the flap from above must be shielded by a plate rigidly connected to the housing, against which the flap rests when it is fully open. The plate 48 can be supplemented by side walls to enhance the effect. Since the plate 48 must completely cover the flap 42 'when it is open, it is proposed to fasten the rod 46 to the flap 42' in this exemplary embodiment with the aid of a small projecting nose 49. As already mentioned, the lever 44 to initiate the emptying only has to be pivoted slightly because of the buoyancy of the float, so it can, as shown in FIG can be supplemented, which is actuated from above by a second rocker 51 integrated in the lid of the cistern. However, to ensure in this embodiment that the flap 42 'opens in the event of full emptying that it abuts the plate 48, the attachment of the rod 46 to the lever 44 must be changed. It is proposed to make an elongated hole 52 in the upper end of the rod 46 so that it can move relative to the lever 44. However, this has the consequence that the stop for partial emptying must now be carried out so that it immediately limits the upward movement of the rod 46 when the lever 44 is pivoted to the left. For this purpose, it is proposed to attach a plate 53 to the left of the lever 44, the right edge of which is slightly angled, as shown in FIG. Since the upper end of the rod 46 is initially shifted somewhat to the right when it is fully emptied, it slides past the plate 53 as the opening process continues. The upper end of the rod 46 is also to be arranged relative to the rocker 50 such that it can move upwards in front of or behind this rocker in the event of full emptying.

With this change in the actuating device, the system is adapted to the widespread practice in European countries of actuating the cistern with a push button.

The fluid-mechanical principle used in the last described embodiment can be applied in a somewhat modified form to the embodiment according to FIG. 3. It is thereby achieved that the magnetic coupling 38, 39 and the additional weight 33 can be dispensed with in the latter while maintaining the compact structure. The resulting additional exemplary embodiment is described below with reference to FIG. 9.

It is proposed to design the device for lifting the valve body 22, 23 so that it fulfills the following function.

When the lever 36 for full emptying is actuated, the valve body is raised, as in the exemplary embodiment according to FIG. 3, to such an extent that the sealing ring 23 almost touches the bottom of the additional container 28. In this position of the sealing ring, the back pressure of the outflowing water is shielded by the bottom of the additional container and the ring 41, so that hardly any mechanical forces act on the valve body. The valve therefore remains open in the manner described earlier until the additional container 28 is almost emptied.

When the lever 35 for partial emptying is actuated, on the other hand, the stroke of the valve body is limited by an actuator so that the sealing ring 23 is still a few millimeters below the lower edge of the ring 41 after actuation of the lever. In this position, a fluidic force acts on the sealing ring. It can be adjusted by suitable dimensioning of the stroke so that it, together with the weight of the valve body, outweighs the buoyancy of the float 27. The valve therefore remains open in this position only until the water level has dropped to the level of the floating body 25. The need to precisely adjust the stroke can be avoided if the ring 41 is provided with windows 60. The dynamic pressure can then take effect through these windows, so that it is sufficient to set the stroke with a few millimeters of clearance so that the sealing ring is located in the area of the lower edge of the ring 41. The effective dynamic pressure can also be increased if the lower edge of the ring 41 is angled outwards, as shown in FIG. 9. Subsequent correction of the force acting on the sealing ring is possible by subsequently clogging individual windows.

A simple design of the actuator for limiting the stroke is shown in FIG. 9.

The bracket 34 is supplemented by a horizontal projection 61 and rotatably supported with the aid of the axis 62. The lever 35 engages in the bracket 34 as in FIG. 3. If this lever is operated, the stroke is suitably limited by the stop 63.

The lever door full emptying, on the other hand, is designed so that it abuts the projection 61 when it is actuated. As a result, the bracket 34 is moved to the left and thus slides past the stop 63. The tilt is limited by the stop 64. After closing the valve, the bracket 34 returns to the vertical position due to the weight of the projection 61.

Claims

Patent claims:

1. toilet cistern with a by means of a float (3) controlled inflow valve and with an operable by a lever mechanism from outside the cistern drain valve for draining one or two different predetermined amounts of liquid, characterized in that the valve body

(2.8; 22.23; 1 ', 2'; 42 ', 46) of the inflow valve or the outflow valve for the action of a hold-open force is designed such that during the filling process only when the cistern is substantially completely full or only during the emptying process with substantially complete emptying of the cistern (21), the forces causing a closing of the inflow valve or the outflow valve can quickly overcome the hold-open forces.

2.WC cistern according to claim 1, characterized in that for a partial emptying of the cistern by a separate actuation of the lever mechanism, this hold-open force does not act on the valve body (22, 23; 1 ', 2') of the drain valve, and that in average water level according to the amount of water to be dispensed, a float (25; 3 ') is arranged and connected to the valve body of the drain valve, the buoyancy force exerted by the float on the valve body until the partial emptying process is greater than the closing forces acting on the valve body and at At the end of the partial emptying process, the closing forces exceed the decreasing buoyancy of the float.

3. toilet cistern according to claim 1 or 2, characterized in that the hold-open force for acting on the valve body (2,8) of the inflow valve is realized by a magnetic coupling (6,7), of which a link (7) with the cistern housing (21) and the other link (6) is connected directly or via a linkage (13) of a lever mechanism to the valve body of the inflow valve.

4. toilet cistern according to claim 3, characterized in that the float connected to the valve body (2,8) of the inflow valve (3) has a step-widening (11) for a sudden increase in buoyancy when the filling process is completed.

5.WC-cistern according to claim 3 or 4, characterized by fluid mechanical and / or magnetic damping means for slowing the closing movement of the inflow valve.

6. toilet cistern according to claim 1 or 2, characterized in that the hold-open force for acting on the valve body (22,23) of the drain valve is realized by a magnetic coupling (38,39), of which a link (39) with the cistern housing (21) and the other link (38) directly via a linkage

(36) of the lever mechanism is connected to the valve body of the drain valve.

7. toilet cistern according to claim 1 or 2, characterized in that the hold-open force for acting on the valve body (1 ', 2') of the drain valve is realized by a mechanical locking member (15 ', 30') which, when the lever mechanism is actuated for one

Full emptying of the cistern is brought into position and returns to its starting position when the emptying is complete.

8. toilet cistern according to claim 1 or 2, characterized in that the hold-open force for acting on the valve body (42 ', 46) of the drain valve is a fluid mechanical, weight and / or buoyancy force which rapidly with substantially complete emptying of the cistern undergoes such a change that the closing forces acting on the valve body of the drain valve can overcome the hold-open force. 9. toilet cistern according to claim 6 or 7, characterized in that the permanent magnets (38,39) or the mechanical locking member C15 ') are released when complete emptying due to the action of gravity against the declining buoyancy of a float (27, 12'), which float in an additional tank (28,

9 '), from which water runs out with a delay through appropriately dimensioned holes (29, 11').

10. toilet cistern according to claim 6 or 7, characterized in that the permanent magnets (38,39) or the mechanical locking member (30 ') are released when complete emptying due to the action of gravity against a declining fluid mechanical force.

11. toilet cistern according to claim 2 and one of claims 3 to 10, characterized in that for separate actuation of the - lever mechanism for partial emptying and full emptying two on the valve body (22, 23; 1 ', 2') of the Ahflußvehtils attacking lever (35,36; 4 ', 8') are provided.

12. toilet cistern according to claim 2 and one of claims 3 to 10, characterized in that for the separate actuation of the lever mechanism for partial emptying and full emptying a single, on the valve body (22, 23; 1 ', 2'; 42 ', 46) of the drain valve engaging lever (44, 8 ') is provided which can be moved in different directions or in the same direction beyond a first pressure point.