Cylinder-piston unit

Abstract

A cylinder-piston unit for actuating a flush valve, comprising a piston which is displaceably mounted in a cylinder and the piston rod of which is operatively connected to a flush valve, and comprising at least one fluid inlet, which opens into the cylinder at or below a lower stop position of the piston, and comprising at least one fluid outlet wherein the piston comprises at least one valve which seals the piston in a lower stop position and opens at least one passage opening in an upper stop position.

Claims

1. A cylinder-piston unit for actuating a flush valve, comprising: a cylinder; a piston which is displaceably mounted in the cylinder; a piston rod which is operatively connected to the flush valve, and at least one fluid inlet, which opens into the cylinder at or below a lower stop position of the piston; and at least one fluid outlet, wherein the piston comprises at least one valve which seals the piston in a lower stop position and opens at least one passage opening in an upper stop position.

2. The cylinder-piston unit of claim 1, wherein the piston comprises multiple valves, each of which seals the piston in the lower stop position and opens at least one passage opening in the upper stop position, the valves being situated on the piston so as to be distributed uniformly and with circular symmetry.

3. The cylinder-piston unit of claim 1, wherein a valve tappet, which engages through at least one passage opening of the piston, is longitudinally displaceably, and captively accommodated in the cylinder-piston unit.

4. The cylinder-piston unit of claim 3, wherein the valve tappet completely seals the passage opening via a lower closure section and tapers in the upward direction.

5. The cylinder-piston unit of claim 3, wherein the piston has multiple passage openings assigned to the piston, and wherein the multiple passage openings are situated on the piston so as to be distributed uniformly and with circular symmetry.

6. The cylinder-piston unit of claim 5, wherein the valve tappet has a plurality of valve tappets and the valve tappets are connected to each other in a lower stop region of a connecting ring.

7. The cylinder-piston unit of claim 3, wherein the valve tappet has a stop in the form of a bulge preventing the valve tappet from descending further through the passage opening.

8. The cylinder-piston unit of claim 1, wherein a snap-fit closure is assigned to the at least one passage opening of the piston, the snap-fit closure, upon reaching the upper stop position, snaps into an open position and, upon reaching the lower stop position, snaps back into a closed position.

9. The cylinder-piston unit of claim 1, wherein the cylinder comprises, as a fluid outlet, a labyrinth seal surrounding the piston rod of the piston to allow fluid introduced into cylinder to seep out.

10. The cylinder-piston unit of claim 1, wherein the piston is surrounded, against the cylinder wall, by a sealing ring which has an at least approximately U-shaped cross-section, wherein the opening of the U-shape faces downward.

11. The cylinder-piston unit of claim 10, wherein the lower stop position of the piston is selected in such a way that, in this lower stop position, the piston rod is decoupled from the flush valve.

12. The cylinder-piston unit of claim 1, further comprising an overflow on an upper side.

13. A method for actuating a flush valve with a cylinder-piston unit, the cylinder-piston unit comprising a piston which is displaceably mounted in a cylinder and a piston rod which is operatively connected to the flush valve, and comprising at least one fluid inlet, which opens into the cylinder at or below a lower stop position of the piston, and comprising at least one fluid outlet, the method comprising: a) lifting the piston from its lower stop position by introducing fluid through the at least one fluid inlet into the cylinder, wherein the piston comprises at least one valve which seals the piston in its lower stop position, b) triggering the at least one valve to open at least one passage opening in the piston when or before the piston reaches its upper stop position, so that the fluid, which has been located beneath the piston so far, can now also pass through the piston into the region above the piston, where the fluid passing through the piston can leave the cylinder via the at least one fluid outlet, and c) triggering the at least one valve to close the at least one passage opening in the piston when the piston engages into its lower stop position.

14. The method of claim 12, wherein the triggering of the at least one valve occurs displacement-controlled.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The above-described disclosure is described in greater detail in the following with reference to some embodiments.

(2) FIG. 1 shows a cross-sectional view from the side of a cylinder-piston unit comprising multiple valve tappets engaging through the piston, in a lower stop position, according to some embodiments.

(3) FIG. 2 shows a cross-sectional view from the side of the cylinder-piston unit according to FIG. 1 in a lifting position, according to some embodiments.

(4) FIG. 3 shows a cross-sectional view from the side of the cylinder-piston unit according to FIG. 1 in an upper stop position, according to some embodiments.

(5) FIG. 4 shows a cross-sectional view of the cylinder-piston unit according to FIG. 2 in a lifting position from another side, according to some embodiments.

(6) FIG. 5 shows a cross-sectional view from the side of the cylinder-piston unit according to FIG. 1 in an output position, according to some embodiments.

(7) FIG. 6 shows a cross-sectional view from the side of a cylinder-piston unit comprising multiple snap-fit closures, according to some embodiments.

(8) FIG. 7 shows a toilet with cistern and a flush valve according to some embodiments.

DETAILED DESCRIPTION OF THE DISCLOSURE

(9) FIG. 1 shows a cylinder-piston unit comprising a cylinder 1 which longitudinally displaceably accommodates a piston 5 therein. The cylinder 1 offers an upper stop for the piston 5 by way of a cylinder cover 2, and offers a lower stop (L) by way of a cylinder base 3. The swept volume extends therebetween and is sufficiently sized in such a way that an upright tube 15, which is connected to a piston rod 6 integral with the piston 5 and is part of a flush valve, can be lifted into an open position. For the purpose of fastening, the piston rod 6 comprises a head and a neck, wherein the neck has been threaded into a sliding bearing 16 of the upright tube. The lower stop position of the piston 5 is selected in such a way that the upright tube 15 is decoupled from the piston 5 in this position, and therefore the head does not about the sliding bearing, and so the flush valve is securely closed.

(10) The cylinder 1 comprises, in the cylinder base 3 thereof, a sleeve-shaped passage 4, through which the piston rod protrudes into the cylinder 1. The piston rod 6 comprises multiple notches around the circumference thereof, in order to form a labyrinth seal in this region. A base of the sleeve-shaped passage 4 overhangs the cylinder base, and therefore a partial region of the cylinder is continually filled with water. Water rising thereabove can drain off through the labyrinth seal. In order to actuate the flush valve from this position and, therefore, to lift the upright tube 15, water under line pressure is allowed to flow under the piston 5 via a fluid inlet (not represented here), the water inflowing more rapidly than it can emerge from the cylinder 1 again via the labyrinth seal of the passage 4. An overpressure builds up under the piston 5 and pushes the piston 5 upward.

(11) An annular seal 8 along the cylinder wall is provided on the edge of the piston 5 and expands, due to the inverted U-shaped cross-section thereof, as a result of the overpressure under the piston 5, thereby offering a good seal with respect to the cylinder wall. Air can escape from the space above the piston 5, however, and therefore no counteracting pressure is built up there.

(12) The piston 5 is pushed upward by way of the water pressure, as shown in FIG. 2. Although the piston 5 comprises passage openings 7, these passage openings are blocked in this position by the valve tappets 9 (valves 24). These valve tappets 9 comprise a closure section 10 sealing the passage openings 7, as well as a tapering 11 toward the top, which would hold a flow region open in the passage opening 7. In the position shown, the three passage openings 7 are blocked by the closure sections 10 of the valve tappets 9, and therefore the water pressure under the piston 5 can increase again. In this position, in addition, the upright tube 15 has already been drawn upward along with the piston rod 6 and begins to release the flush valve.

(13) As the water pressure continues to increase, the upper stop position (U) of the piston 5 shown in FIG. 3 is reached by the piston. Already shortly ahead of this position, the valve tappets 9 impact the cylinder cover 2 via the upper edge thereof, and therefore the piston 5 can continue to move upward, but the valve tappets 9 cannot. The valve tappets 9 therefore push through the passage opening 7 until they can be prevented from descending further by way of a stop 12 of the valve tappets 8. The valve tappets are connected to each other by way of a connecting ring 13, which prevents a non-uniform triggering and a tilting.

(14) The valve tappets now block the passage openings 7 only by way of one central web which is a tapering 11. Water can reach the piston therethrough and can run out into the cistern via an overflow 17. This is shown in FIG. 4 which depicts a cross-section from another direction, in which both the inlet 18 as well as the overflow 17 are represented. The water initially continuing to flow in through the inlet 18 will push the piston 5 upward, but the pressure under the piston 5 will rapidly decrease. If the inflow through the inlet 18 finally ends by way of the flush valve being closed, the pressure under the piston 5 is reduced to such an extent that the piston can descend again. This final phase of the flushing process is shown in FIG. 5. Since the valve tappets 9 and the connecting ring 13 connecting them are made of a lightweight plastic, a circumferential lowering weight 14 is assigned to the connecting ring 13, which is intended to prevent the valve tappets 9 from being pushed back into the closed position thereof due to the remaining water pressure. While the remaining water escapes from the cylinder through the passage 4 and the upright tube 15, the piston 5 descends back into the position shown in FIG. 1, wherein the valve tappets 9 block the passage openings 7 again due to the lower stop. In this position, the upright tube 15 is then decoupled from the piston rod 6 again, in order to be able to descend all the way back into the lower final position, and the flush valve is completely closed, and therefore the cistern can be filled again.

(15) FIG. 6 shows a cylinder-piston unit according to the second embodiment. Assigned to the at least one passage opening 7 of the piston 5 is an exemplary snap-fit closure 27 which, upon reaching the upper stop position (U, see right side of FIG. 6), snaps into an open position and, upon reaching the lower stop position (L, see left side of FIG. 6), snaps back into a closed position.

(16) FIG. 7 shows a flush valve 21, in which a triggering of the flushing process in a cistern 28 is to take place by means of the inflow (fluid inlet 22) of tap water. In this case, the tap water is introduced into the cylinder-piston unit 20. Since the piston rod is connected to the flush valve, the flush valve is lifted off of the valve seat along with the lifting of the piston in the cylinder-piston unit 20, and the flushing process can take place e.g. water is released via the fluid outlet 23 into the toilet 23.

(17) A cylinder-piston unit is therefore described above, which provides a piston comprising a valve which is opened and closed in a displacement-controlled manner and, therefore, can bring about a reliable triggering of a flushing process and the termination thereof, independently of the prevailing water pressure.

(18) Numerous flush valves are known from the prior art, which utilize the line pressure in order to trigger the actual flushing process. This makes it possible to largely dispense with actuators which, in the field of sanitation, can result in a conflict between the use of electricity and water. In this case, in the prior art, the pistons are pushed against the force of a compression spring, and therefore the compression spring can return the piston to the starting position as the pressure decreases. This means, however, that the compression spring must, in some embodiments, be adapted to the water pressure prevailing in a region, and therefore a suitable compression spring must, in some embodiments, be initially found, during installation, in order to ensure optimal function. This problem is solved by the disclosure, in that the disclosure adds a valve to the piston, which is opened and closed in a displacement-controlled manner and, therefore, can bring about a reliable triggering of a flushing process and the termination thereof, independently of the prevailing water pressure.