Pressure-flushing cistern for a water closet

Abstract

The pressure-flushing cistern comprises a pressure tank (2), an actuating device for initiating a flush and also a pressure-reducing valve (27), which is to be connected to a water pipe and via which the pressure tank (2) can be filled with flushing water. The closing pressure of the pressure-reducing valve (27) is adjustable with a displaceable ring (17). The ring (17) can be gripped from outside through a window (19) of a housing (6) for adjusting the closing pressure. Adjustment preferably takes place by steps.

Description

The invention relates to a pressure-flushing cistern for a water closet, with a pressure tank, an actuating device for initiating a flush, a pressure-regulating valve, which is to be connected to a water pipe and by means of which the pressure tank can be filled with flushing water, and with an outlet valve.

A pressure-flushing cistern of this kind has become known in the prior art from WO 98/39522, for example. Pressure-flushing cisterns of this kind have the advantage that they make effective cleaning of the water closet bowl possible with relatively low water consumption. The pressure tank is filled with flushing water by means of a water pipe connected to the pressure-flushing cistern. During this operation, air present in the pressure tank is compressed. If the outlet valve is opened, flushing water is discharged into the water closet bowl as the air expands. The outlet valve is designed as a piston and closes the outlet valve when the flushing water has flowed out.

A further component of the pressure-flushing cistern is what is known as the system separator, which prevents flushing water being sucked from the pressure tank into the supply line in the event of low pressure in the water pipe. Such a system separator (vacuum breaker) is disclosed in the said WO 98/39522.

In order that a predetermined pressure is not exceeded in the pressure tank after it has been filled, a pressure-reducing valve is provided, which limits the maximum pressure. In the case of the pressure-flushing cistern mentioned above, this pressure-reducing valve comprises a piston which is subjected to the pressure in the pressure tank and closes the mouth of a nozzle counter to the reacting force of a spring. When the pressure in the pressure tank falls during flushing, the piston of the pressure-reducing valve is displaced owing to a pressure difference on the piston, and the inlet valve is thus opened. Water flows into the pressure tank through the opened mouth of the nozzle. When a predetermined pressure in the pressure tank is reached, the pressure-reducing valve closes. The designated maximum pressure in the pressure tank can be changed by exchanging the said spring. A stronger spring results in a higher pressure and a weaker spring a lower pressure. However, such an exchange of the spring is relatively involved.

The invention is based on the object of producing a pressure-flushing cistern of the said kind which makes possible simpler change-over to a different maximum pressure in the pressure tank.

The object is achieved in a pressure-flushing cistern of the generic type characterized in that the closing pressure of the pressure-regulating valve is adjustable.

According to a development of the invention, the closing pressure of a counterpressure spring of the pressure-reducing valve is adjustable. According to a development of the invention, this can be effected especially simply constructionally and also in a user-friendly way when the pressure spring can be adjusted with an adjusting ring, the adjusting ring forming a counterbearing for the spring.

The valve housing of the inlet valve is preferably of laterally open design, so that the adjusting ring can be reached and displaced from outside. Recesses in the form of steps, which in each case correspond to an adjusted position of the adjusting ring, are preferably arranged on the valve housing. For example, one such step corresponds to an internal pressure of 1.5 bar, a second recess to an internal pressure of 2 bar and another recess to an internal pressure of 2.5 bar.

According to a development of the invention, the adjusting ring comprises holding projections for its stepped displacement. These holding projections are accessible from outside and are in each case fixed in a corresponding recess of the valve housing. A version in which the adjusting means, or the adjusting ring, is continuously displaceable is also conceivable.

A particularly simple and cost-effective construction is brought about when the pressure-reducing valve is arranged at the outlet of a system separator. According to an advantageous development of the invention, the said adjusting ring is arranged axially displaceably on the periphery of a nozzle body of the pressure-reducing valve.

Further advantageous features emerge from the dependent patent claims, the description below and the drawing.

An illustrative embodiment of the invention is explained in greater detail with reference to the drawing, in which:

FIG. 1 shows a vertical section through part of the pressure-flushing cistern according to the invention, the inlet valve being open;

FIG. 2 shows a section according to FIG. 1, but with the inlet valve closed;

FIG. 3 shows a section through the inlet valve and the reducing valve, the inlet valve being closed;

FIG. 4 shows a section according to FIG. 3, but with the inlet valve open, and

FIGS. 5 to 7 show part views of the pressure-flushing cistern with different settings of the closing pressure.

The pressure-flushing cistern 1 has a pressure tank 2, shown only in part in FIG. 1, which has a pressure space 3 which is filled with flushing water via a pressure-reducing valve 27. For the supply of the flushing water, the pressure-flushing cistern 1 is connected to a pressure water pipe (not shown here) at a connection neck 5 of a system separator 25. The per se known system separator 25 is provided for reasons of safety and prevents water passing from the pressure tank 2 into the supply line in the event of low pressure. Such system separators are regulation in many countries and known per se.

The system separator 25 comprises a housing 6 which at a lower end forms a horizontally extending nozzle body 21. A channel 15 with a mouth 4 likewise extends horizontally in the nozzle body 21.

The nozzle body 21 is part of a pressure-reducing valve 27 which is arranged at the outlet of the system separator 25. The pressure-reducing valve 27 has a cap-shaped housing 7, which is inserted into an opening 31 of the housing 6. The connection of the housing, 7 to the housing 6 can be designed as a bayonet or screw connection, for example. The housing 7 has at one end an opening 8, which leads into a pipe 30 and finally into the pressure tank 2.

The front end of the nozzle body 21 forms a valve seat 14 which interacts with a-closing body 12. This closing body 12 is preferably designed as a ball and mounted in a flow channel 13 of a piston 9. This piston 9 has a guide part 18 which is sealed displaceably in relation to the housing 7 by a seal 29. Moreover, the guide part 18 is likewise sealed displaceably in relation to the nozzle body 21 by a further seal 28. As can be seen, the seal 28 is located directly behind the valve seat 14. The piston 9 is consequently guided displaceably in the direction of the channel 15 in a limitable way.

An insert 32, in which a further closing body 11 which closes a passage 33 (FIG. 4) is mounted, is inserted into the guide part 18. According to FIG. 4, this passage 33 connects passages 10 of the insert 32 to the flow channel 13.

Moreover, the pressure-reducing valve 27 comprises a pressure spring 16, which is designed as a helical spring and is supported at one end on an adjusting means 17 and at the other end on the guide part 18 of the piston 9. As can be seen, the adjusting means 17 is of ring-shaped design and forms a counterbearing for the pressure spring 16. As can be seen, the adjusting means surrounds the nozzle body 21 and is guided displaceably on a cylindrical inner surface 34 of the housing 6.

The prestress of the pressure spring 16 can be adjusted by moving or displacing the adjusting means 17. For this purpose, the adjusting means 17 has at least one projection 22, which, according to FIG. 5, is accessible through a window 19 of the housing 6. According to FIGS. 5 to 7, recesses 20, 23 and 24, which in each case form a seat for a projection 22, are arranged in this window 19. The recesses 20, 23 and 24 are designed in such a way that the corresponding positions of the projection 22 are offset in the form of steps in the longitudinal direction of the channel 15. The recess 20 shown in FIG. 5 forms a first position, in which the adjusting means 17 is furthest away from the mouth 14. In this position, the prestress of the pressure spring 16 is at its lowest. With appropriate positioning of the projection 22 in the recess 23, this recess 23 produces a medium prestress, and the recess 24 produces the greatest prestress of the pressure spring 16. The adjusting means 17 can be displaced between these three positions. This is effected by the adjusting means 17 being taken hold of on the two projections 22, unlocked by turning, displaced and locked again by turning once more. In principle, more or fewer steps are also possible. It is moreover conceivable to make possible continuous displacement, for example by means of a thread. However, the step arrangement makes adjustment easier.

With the pressure tank 2 filled with water, the internal pressure of the pressure space 3 acts via the opening 8 mentioned above on the outer surface indicated by B in FIG. 4 of the piston 9. In FIG. 3, the arrow 26 indicates the direction in which the internal pressure of the pressure tank 2 acts on the piston 9. The pressure on the piston 9 is so great that the force of the pressure spring 16 is overcome and the closing body 12 is held on the valve seat 4. In this position, the mouth 4 of the channel 15 is closed. Moreover, the closing body 11 bears against the passage 33 and closes it.

When a flush is initiated, the compressed air in the pressure space 3 expands and the pressure on the surface B of the piston 9 is accordingly reduced. When the pressure falls below a given level, the pressure spring 16 moves the piston 9 to the left in. FIG. 3 into the position shown in FIG. 4. Accordingly, the closing body 12 is moved away to the left from the mouth 14, and the closing body 11 is likewise moved away to the left from the passage 33. Water can then flow into the flow channel 13 through the channel 15. From this flow channel 13, the water flows around the closing body 12 and passes through the passage 33 and the lateral passages 10 to the opening 8 and finally through the pipe 30 into the pressure space 3 of the pressure tank 2. If the outlet valve (not shown here) in the bottom of the pressure, tank 2 is closed, the pressure space 3 fills with water and the air contained therein is accordingly compressed. Once the designated pressure of for example 1.5, 2 or 2.5 bar has built up in the pressure space 3, a corresponding pressure acts on the piston 9. As the surface B is considerably larger than an inner surface A (FIG. 4) of the piston 9, a force finally results which moves the piston 9 to the right in FIG. 4 into the position shown in FIG. 3. This closing force is dependent on the prestress of the pressure spring 16, or the adjusted position of the adjusting means 17. If the adjusting means 17 are in the position according to FIG. 5 for example, the pressure-reducing valve 27 closes at 1.5 bar for example. The medium closing pressure is 2 bar for example, and the highest closing pressure 2.5 bar. When the mouth 4 is closed by the closing body 12, the closing body 11 is also displaced on account of the pressure and thus closes the passage 33. This maximum pressure is maintained until a flush is initiated again. Subsequently, the operations mentioned above are repeated, that is the pressure-reducing valve 27 is opened again until a maximum designated pressure is achieved. If a maximum pressure once adjusted is to be changed, the adjusting means 17 are, as mentioned above, moved into another position by hand. As no parts have to be exchanged or replaced here, such a change of the maximum pressure is possible simply and without further action. This results in both easier assembly, in particular, but also in easier stockkeeping as no exchange parts have to be kept in stock.

LIST OF REFERENCES

• 1 pressure-flushing cistern
• 2 pressure tank
• 3 pressure space
• 4 mouth
• 5 connection
• 6 housing
• 7 housing (cap)
• 8 opening
• 9 piston
• 10 passage
• 11 first closing body
• 12 second closing body
• 13 flow channel
• 14 valve seat
• 15 channel
• 16 pressure spring
• 17 adjusting means (ring)
• 18 guide part
• 19 window
• 20 recess
• 21 nozzle body
• 22 projection
• 23 recess
• 24 recess
• 25 system separator
• 26 arrow
• 27 pressure-reducing valve
• 28 seal
• 29 seal
• 30 pipe
• 31 opening
• 32 insert
• 33 passage
• 34 inner surface
• A piston surface (small)
• B piston surface (large)

Claims

1-7. (canceled)

8. Pressure-flushing cistern for a water closet, with a pressure tank, an actuating device for initiating a flush, a pressure-reducing valve, which is to be connected to a water pipe and via which the pressure tank can be filled with flushing water, and with an outlet valve, wherein the closing pressure of the pressure-reducing valve is adjustable.

9. Cistern according to claim 8, characterized in that the closing force of a counterpressure spring of the pressure-reducing valve is adjustable.

10. Cistern according to claim 8, characterized in that the adjusting means are designed as a ring and this ring forms a counterbearing for the pressure spring.

11. Cistern according to claim 8, characterized in that the closing pressure can be adjusted by steps or continuously.

12. Cistern according to claim 8, characterized in that the adjusting means are arranged on the periphery of a nozzle body.

13. Cistern according to claim 8, characterized in that the pressure-reducing valve is arranged at the outlet of a system separator.

14. Cistern according to claim 8, characterized in that the pressure-reducing valve comprises in a housing at least one lateral window through which the adjusting means are accessible or can be gripped for adjusting the closing pressure.