WO2015136394A1

WO2015136394A1 - Flush cistern and respective activating method

Info

Publication number: WO2015136394A1
Application number: PCT/IB2015/051136
Authority: WO
Inventors: Giorgio RAMORINO; Giovanna Cornacchia; Marco Conforti; Luigi TIBERTI
Original assignee: Marvon S.R.L.
Priority date: 2014-03-12
Filing date: 2015-02-16
Publication date: 2015-09-17

Abstract

A WC flush cistern (1) comprises an actuator (5) provided with a metal shape-memory element (6) subjected to a dimensional change as a response to its temperature variation. In particular, the cistern actuator (5) comprises at least one metal shape-memory element (6) connected to the shutter element (4), and means operable by the user to impart a temperature change to the metal element and, therefore, control the displacement of the shutter element (4) between the closed position and the open position of the discharge opening of the cistern (1), thereby obtaining the rinsing of the WC.

Description

FLUSH CISTERN AND RESPECTIVE ACTIVATING METHOD

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DESCRIPTION

Field of the invention

The present invention relates to a flush cistern for sanitary use, i.e. of the type used to discharge rinse water in a toilet, and particularly relates to a flush cistern provided with an innovative actuator for activating the movable parts.

State of the art

A conventional flush cistern is provided with a container for collecting water, an adduction valve of water into the container, and a discharge valve for discharging water from the container into the toilet.

The adduction valve intercepts a corresponding line supplied by mains water and opens up in order to allow the container to be filled after each rinse. Typically, a float placed in the container controls the opening and closing of the adduction valve. As the container is emptying, the float drops following the decreasing water level up to a point where it activates the opening of the adduction valve by means of levers. Conversely, as the container is filled again after a toilet rinse, the float rises together with the water level and, by means of the afore mentioned levers, closes the adduction valve, thereby preventing the water level from exceeding a threshold level.

The discharge valve consists of a shutter element for a discharge hole formed through the bottom of the container. The hole is usually circular and the shutter element is cylindrical and is externally provided with a gasket which moves in abutment against the inner edge of the hole in order to ensure the coupling seal. The lifting of the shutter element inside the container, thereby clearing the discharge hole, is sufficient for the water to be discharged: the water falls by gravity from the container into the toilet below. The user imparts a vertical movement to the shutter element by means of a mechanical actuator, such as a button and lever system or a pneumatic actuator or, in more elaborate versions, by means of an electric motor lifting the shutter element. The shutter element, by virtue of its own weight or due to water pressure, is moved back in abutment against the bottom wall of the container in order to intercept the hole .

The collecting container is always placed in a higher position with respect to the toilet. In particular, it can be mounted outside of the wall or it can be built into the wall, so as to be hidden from view. In this second case, the user activates the rinse by means of a mechanical or electrical button (depending on the type of actuator provided for lifting the shutter element) placed on the wall .

The market imposes inexpensive flush cisterns which are not subject to oxidation or stray-current corrosion and, especially, which can not be attacked by chemical agents, for example detergents. Therefore, for decades now, flush cisterns are made of plastic material, that is to say that the container, the float, the shutter element and the levers are all made of plastic, if possible recyclable.

The main drawback of the currently available solutions is that the complexity of geometries of the described components increases more and more, in particular as regards the lever system used for lifting the shutter element, regardless of the type of installed actuator.

For this reason manufacturers are forced to make equally complex molds, of course resulting in an increase of costs and production and assembly times.

Moreover, the high number of plastic components of flush cisterns forces manufacturers to stock many spare parts and negatively affects the assembly time during the production step.

Furthermore, due to the complexity of parts, it is often difficult for the plumber to install the cisterns. Summary of the invention

It is an object of the present invention to provide a flush cistern and a corresponding activating method that solve the drawbacks of the conventional solutions in a simple and effective way.

In particular, the present invention intends to provide a flush cistern having a simple structure but, at the same time, that is reliable, easy and cost-effective to be realized and assembled.

Therefore, a first aspect of the present invention relates to a flush cistern of a WC according to claim 1.

In particular, the flush cistern comprises a hollow body for containing a rinse liquid - typically water or water mixed with a detergent - in its turn provided with a discharge opening hydraulically connected to the WC . The hollow body can be built into a wall, if the flush cistern is of built-in type, or not, if the cistern is of the type that can be mounted outside of a wall, above the WC .

Inside the hollow body a shutter element is positioned as movable between a closed position, at which it intercepts the discharge opening in order to prevent the rinse liquid from flowing out, and an open position, at which it does not intercept the discharge opening, or only partially intercepts it, to allow the discharge of the rinse liquid to the WC connected to the discharge opening.

The flush cistern further comprises an actuator controlling the displacement of the shutter element at least between the closed position and the open position, and possibly also between the open position and the closed position .

Advantageously, unlike the conventional solutions, the actuator is not formed by a complicated system of levers but is instead of very simple structure exploiting the properties of a shape-memory element subjected to a dimensional change as its temperature varies.

In particular, the cistern actuator according to the present invention comprises at least one metal shape-memory element connected to the shutter element and means operable by the user to impart a temperature change to the metal element and, therefore, to control the displacement of the shutter element between the closed position and the open position, thereby obtaining the rinse of the WC .

Especially compared to currently available solutions, the proposed solution involves the use of a limited number of components, all readily available on the market. The shape-memory element substantially replaces the conventional leverages. In addition, by adjusting the heating rate, the law of motion of the shutter element can be correspondingly changed. It is therefore always possible to get a slow or quick activation without structurally modifying the cistern. In this way it is therefore possible to adjust the discharged flow rate and amount of water.

In the preferred embodiment, the metal shape-memory element is a metal wire having a first end fastened to the shutter element and a second end fastened to the hollow body or to a covering element thereof, for example the upper cover of the cistern. An electric circuit is connected to the metal shape-memory wire so that the metal wire constitutes the resistor of the circuit itself; if necessary, the metal wire is supplied with electric current and heats up because of Joule effect.

The heating of the metal wire with respect to the initial temperature, for example the room temperature, causes its temporary contraction. In other words, as the temperature increases the wire shortens.

Preferably, after each activation, the shutter element is automatically brought back to the closed position by means of the weight applied by a stabilizing mass obtained within the shutter element itself or in another element coupled therewith, for example two cup-shaped portions always full of water.

The return of the shutter element to the closed position causes the metal wire to extend, preferably up to its initial length, so that the wire is ready for a new heating, i.e. a new activation of the flush cistern.

The heating time, i.e. the lapse of time comprising the heating ramp, the possible maintaining at a certain temperature and the cooling of the wire back to the starting/room temperature, corresponds to the time needed for totally emptying the hollow body of cleaning liquids, or for only partially emptying it, as preferred.

Thus, the skilled person will appreciate that by exploiting the shape-memory properties of the metal wire, the movement of the shutter element, at least the opening thereof, can be controlled.

By adjusting the current passing through the metal wire, its contraction speed and accordingly the law of motion of the shutter element, can be accurately controlled .

Clearly, to avoid the possibility of short circuits, the metal wire is preferably coated with an insulating sheath, or is inserted for most of its length into the shutter element itself so as not to be exposed to the rinse liquid, or else it is positioned at a height preventing it from touching the water.

Preferably, the means intended to impart a temperature change to the metal wire comprise an electronic control unit electrically supplied from the outside or by a battery and connected to a control element the user can activate, for example an activation button, a presence sensor or an IR, capacitive, volumetric sensor, etc., typically activated by the user in order to rinse the WC . The electronic control unit is electrically connected to the metal wire by means of the above described electric circuit; the activation of the electronic control unit by the user corresponds to the closing of the electric circuit .

Preferably, the cistern comprises at least one winding element on which the metal wire forms one or more windings. The winding element is useful because the percentage elongation of the wire with respect to its initial length is limited; to obtain the desired stroke of the shutter element is necessary to have a minimum length of the wire, which is available in the form of windings. The winding element is therefore a "reserve" where one or more windings of the wire are collected.

According to a structural modification, the winding element is a spool constrained to the hollow body and rotating on its own longitudinal axis. For example, the spool is rotating on a horizontal axis and the metal wire extends vertically. The heating of the metal wire produced by the electric current, with respect to the room temperature, causes a temporary shortening of the wire itself and an additional corresponding winding on the spool. Due to the interruption of power supply and to the weight applied by the stabilizing mass, the metal wire returns to its starting length and correspondingly unwinds from the spool.

As an alternative to the spool, pulleys or a hoist can be used. According to a further modification, the flush cistern comprises several pulleys constrained to the hollow body; the heating of the metal wire causes a temporary shortening of the wire itself and corresponding rotations of the pulleys; the stabilizing mass causes the metal wire to return to its starting length and corresponding rotations of the pulleys in a way opposite to the previous rotation .

According to a more articulated embodiment, the cistern comprises at least two metal shape-memory elements working in opposite directions. One is intended to pull the shutter element to the open position and the other is intended to pull the shutter element to the closed position. Clearly, the two metal shape-memory elements are operable alternately in order to control the displacements of the shutter element in the two ways.

A second aspect of the present invention relates to a method according to claim 10 for rinsing a WC by means of the above described cistern.

The method comprises the steps of:

a) connecting a flush cistern to a WC and filling the hollow body with the rinse liquid;

b) temporarily heating the metal shape-memory element to cause a variation of at least one dimension thereof, for example the length, which in turn causes the displacement of the shutter element from the closed position to the open position and the discharge of the rinse liquid through the opening towards the WC;

c) closing the discharge opening by the shutter element and filling again the hollow body with the rinse liquid, so that the cistern is ready to be used again.

Preferably, between step b) and step c) it is also carried out the additional step of:

b') stopping the heating of the metal shape-memory element, letting it return to the initial/room temperature and/or the step of:

b'') activating a second metal memory-shape element in a way opposite to the first one in order to bring the shutter element back from the open position to the closed position, after the heating of the first metal shape-memory element has been stopped.

List of figures

Further characteristics and advantages of the invention will be more evident from a review of the following specification of a preferred, but not exclusive, embodiment, shown for illustration purposes only and without limitation, with the aid of the attached drawings, in which:

figure 1 is a vertical sectional view of a first embodiment of the flush cistern according to the present invention, having the flush closed;

- figure 2 is a vertical sectional view of the flush cistern shown in figure 1, having the flush open;

- figure 3 is a vertical sectional and perspective view of the flush cistern shown in figure 1, having the flush closed;

- figure 4 is a vertical sectional view of a second embodiment of the flush cistern according to the present invention, having the flush closed;

figure 5 is a vertical sectional view of the flush cistern shown in figure 4, having the flush open.

Detailed description of the invention

Figure 1 shows a vertical section of a cistern 1 according to the present invention. The cistern body 2 is intended to be filled with a rinse liquid of a WC, typically water or water and a detergent. The cistern 1 can be of the built-in type or not. A discharge opening 3 is obtained on the bottom of the body 2 for the hydraulic connection with the WC . In this way, the liquid falls by gravity from the cistern 1 into the WC . A cover 7 closes the body 2 at its top. An electronic control unit 8, intended to operate the cistern 1 and electrically supplied by an internal battery (not shown) or from outside by the connection 14, is fastened to the cover 7. Alternatively, the electrical control unit is constrained to the body 2 or to other cistern elements.

Although not visible in the figures, the control unit

8 is connected to a control element operable by the user, such as an IR, capacitive, volumetric button, etc. The electronic control unit 8 and an end 62 of the metal shape- memory wire 6 are fastened to the supporting structure 71; the other end 61 of the wire 6 is fastened to a shutter element 4 vertically movable between the closed position of the opening 3, just shown in Figure 1, and an open position, shown in figure 2.

The metal wire 6 is wound on a spool 10 constrained to the supporting structure 71 so that it can rotate on its longitudinal axis, which is horizontal in figure 1.

The numeral 9 is referred to an electric circuit (only schematically shown) controlled by the control unit 8 and connected to the metal wire 6 so that the wire acts as a resistor.

The operation of the cistern 1 is easy. The user activates the control element and the electronic control unit 8 closes the electric circuit 9, causing the heating of the wire 6 because of the Joule effect.

Under these conditions the metal wire 6 undergoes a phase transformation resulting in a contraction, thereby further winding on the spool 10 that reacts by rotating on its own axis, and reducing its length of a value A corresponding to the upward stroke, for example 3 cm, imparted to the shutter element 4 .

Figure 2 shows the cistern 1 with the shutter element 4 lifted such that it does not intercept the discharge opening 3 thereby allowing the water A to flow as shown by the arrows .

By comparing the figures 1 and 2 it can be noted the vertical movement imparted to the shutter element 4 : in this way the water discharge and the rinse of the WC are obtained .

After a preset time, which is enough to discharge the desired volume of water from the cistern 1 , the preferably programmable electronic control unit opens the circuit 9 , thus stopping the power supply to the metal wire 6 . The latter cools down and simultaneously the stabilizing masses 12 , which are full and out of water, bring the wire 6 back to its starting length due to their own weight.

The action of the stabilizing masses 12 can be performed, alternatively, by a second metal wire that, when suitably heated, brings the shutter element 4 to the closed position .

In this way the shutter element 4 can be brought back to the closed position.

Figure 3 shows in sectional and perspective view the cistern 1 without the wire 6 , for the sake of clarity. The shutter element 4 closes the opening 3 . The reference X is referred to the axis of rotation of the spool 10 . The body 2, the shutter element 4, the cover 7 and the supporting structure 71 can be made of a plastic material, as usually planned.

At its lower part, the shutter element 4 is provided with two cup-shaped portions 12 intended to fill with water and to push the shutter element 4 itself to the closed position, after each use of the cistern 1. In order to fill the cistern 1 after every use, it is possible to connect water adduction tubes at the openings 13. As the skilled person will appreciate, the cistern 1 can be provided with valves, for example float valves, configured to stop the water adduction when the desired level is reached in the body 2.

Figures 4 and 5 show a second embodiment of the cistern 1 with the shutter element 4 in the closed position and in the open position, respectively.

The cistern 1 comprises, in place of the spool 10, a system of pulleys 11 on which the metal shape-memory wire 6 partially winds. Due to the heating the wire 6 contracts, thereby rotating the pulleys 11 in a first way; after stopping the current in the circuit, the stabilizing masses 12 push the shutter element 4 back to the closed position making the pulley 11 rotate in the opposite way.

In order to allow a fine tension adjustment of the metal wire 6, the position of the pulleys can be set.

Preferably, as afore mentioned, the electronic control unit 8 can be programmed for adjusting the tension applied to the wire 6 and, therefore, adjusting the respective heating in terms of maximum achieved temperature and heating rate (ramp) . In this way the law of motion of the shutter element 4 can be adjusted.

Preferably a sheath, not shown in figures, insulates the wire 6 from water.

Although not shown in figures, the cistern 1 can be provided with a second metal shape-memory wire in order to push the shutter element 4 to the closed position, by operating in a direction opposite to the wire 6.

Claims

1. A WC flush cistern (1) comprising:

- a hollow body (2), for containing a rinse liquid, in its turn provided with a discharge opening (3),

- a shutter element (4) movable between a closed position, at which it intercepts the discharge opening (3) to prevent the rinse liquid from flowing out, and an open position, at which it does not intercept the discharge opening (3) to allow the discharge of the rinse liquid, and

an actuator (5) controlling the displacement of the shutter element (4) at least between the closed position and the open position,

characterized in that

the actuator (5) comprises at least one metal shape-memory element (6), connected to the shutter element (4) and subjected to a dimensional change as a response to a temperature variation, and means (8) operable by the user to impart a temperature change to the metal element (6) and, therefore, control the displacement of the shutter element ( 4 ) .

2. Flush cistern (1) according to claim 1, wherein the metal shape-memory element (6) is a metal wire provided with its first end (61) fastened to the shutter element (4) and a second end (62) fastened to the hollow body (2) or to a supporting element (71) constrained thereto, and wherein the means (8) to impart a temperature change to the metal wire (6) comprise an electric circuit (9) able to supply the metal wire (6) and to cause its heating because of Joule effect.

3. Flush cistern (1) according to claim 2, wherein the heating of the metal wire (6), with respect to the room temperature, causes its temporary contraction, depending on temperature increase.

4. Flush cistern (1) according to claim 2 or claim 3, wherein the means (8) to impart a change temperature to the metal wire (6) comprise an electronic control unit (8), electrically supplied from the outside or by a battery connected to an activation button the user can activate, and electrically connected to the metal wire (6) by means of the electric circuit (9), and wherein the activation of the electronic control unit (8) by the user corresponds to the closing of the electric circuit (9) .

5. Flush cistern (1) according to any one of claims 2- 4, comprising at least one winding element (10) on which the metal wire (6) makes one or more loops.

6. Flush cistern (1) according to claim 5, comprising a winding element (10) having the shape of a spool constrained to the hollow body (2), rotating on its own longitudinal axis, and wherein the heating of the metal wire (6) produced by the electric current supplied thereto, with respect to the room temperature, causes a temporary shortening of the wire (6) itself and an additional corresponding winding on the spool (10) and wherein a stabilizing mass (12) applies on the shutter element (4) a force sufficient to bring it back to the closed position, causing the metal wire (6) to return to its starting length and a corresponding unwinding from the spool (10) .

7 . Flush cistern (1) according to claim 5, comprising several winding elements (11) having the shape of pulleys or hoist, constrained to the hollow body (2), and wherein the heating of the metal wire (6) produced by the electric current supplied thereto, with respect to the room temperature, causes a temporary shortening of the wire (6) itself and corresponding rotations of the pulleys (11) and wherein, after the heating of the metal wire (6) has been stopped, a stabilizing mass (12) applies on the shutter element (4) a force sufficient to bring it back to the closed position, causing the metal wire (6) to return to its starting length and corresponding rotations of the pulleys (11) in the opposite way.

8 . Flush cistern (1) according to any one of preceding claims 1-7, comprising at least two metal shape-memory elements, one (6) intended to pull the shutter element (4) to an open position and the other intended to pull the same shutter element (4) to a closed position, wherein the at least two metal shape-memory elements are operable alternately .

9. Flush cistern (1) according to any one of preceding claims 1-8, comprising one or more of the following features :

- the discharge opening (3) is obtained on the bottom of the hollow body (2) ;

- the shutter element (4) is shaped as a pin, in case provided with a gasket that is sealingly inserted into the discharge opening (3), or into an additional element placed between the hollow body (2) and the shutter element (4) ;

- the shutter element (4) is provided with one or more cup- shaped portions (12), named stabilizing mass, intended to fill with rinse liquid and to push the shutter element (4) to the closed position; - it comprises adduction means (13) of the rinse liquid, for example water, and respective valves;

the flush cistern is of the built-in type for the mounting in a wall or else it can be placed outside of the wall .

10. A method for rinsing a WC, comprising the steps of:

a) connecting a flush cistern (1) according to any one of preceding claims 1-9 to a WC and filling the hollow body (2) with the rinse liquid;

b) temporarily heating the metal shape-memory element (6) to cause a variation of at least one dimension thereof, for example the length, which in turn causes the displacement of the shutter element (4) from the closed position to the open position and the discharge of the rinse liquid through the opening (3) towards the WC;

c) closing the discharge opening (3) by the shutter element (4) and filling again the hollow body (2) with the rinse liquid.

11. Method according to claim 10, wherein between the step b) and the step c) it is also carried out the additional step of:

b') stopping the heating of the metal shape-memory element (6), letting it return to the initial temperature and/or

the step of:

b' ') activating a second metal memory-shape element (6) in a way opposite to the first one in order to bring the shutter element (4) back from the open position to the closed position.

12. Method according to claim 10 or claim 11, wherein the duration of step b) and/or step b'), i.e. the lapse of time comprising the heating ramp, the possible maintaining at a certain temperature, and the cooling of the wire back to the room/starting temperature, is comprised in the range of 1-20 seconds.