WO2021053301A1

WO2021053301A1 - Flushing system

Info

Publication number: WO2021053301A1
Application number: PCT/FR2020/051610
Authority: WO
Inventors: Emmanuel BLIN
Original assignee: Blin Emmanuel
Priority date: 2019-09-19
Filing date: 2020-09-18
Publication date: 2021-03-25
Also published as: FR3101084A1

Abstract

The present invention relates to a flushing system having at least one tank (100) associated with a siphon (300) formed by a structure that is fixed with respect to said tank (100) and at least one supply means (130) for filling the tank (100). Said supply means is controlled by at least one valve or solenoid valve (200) controlled by a circuit board that receives a signal from a detector (400) for the water level in the tank (100) and also a signal for triggering the initiation of the siphon.

Description

FLUSH

Field of the invention

The field of the present invention is that of sanitary appliances and in particular of pressureless flushes (other than atmospheric) for toilets. These devices include a tank fitted with a water supply device managed by a float and a dump device.

There are two main types of toilet flushing cistern emptying devices.

The first - the most widespread - are based on the opening of a valve placed at the bottom of the tank which is raised to release the water contained in the tank. The second implement a siphon which can take the form of a movable bell or, more commonly, of an asymmetric inverted U, one of the branches of which is immersed in the tank and the other is connected to the outlet towards the bowl. These latter siphon systems have the advantage, compared to traditional valve systems, of never leaking due to the emptying device, the neck of the siphon being high and serving as an overflow. They generally include at the end of their inlet branch submerged in the tank a non-waterproof piston of various shapes made up of a plastic shutter or an elastic membrane which lifts a column of water sufficient to fill the neck of the siphon. which thus primers and empties the water from the reservoir. Other systems with siphon have been proposed:

- a mechanism that pushes a column of water to create the siphon effect; - floats which support the neck of the siphon which can then be lowered to prime it.

They have the drawback that the bottom of the water inlet branch can be located far from the bottom of the tank, which has the effect that only part of the water in the tank is used during the flushing. The siphon is in fact defused as soon as the water level in the tank passes below the bottom of the inlet branch.

The invention relates more specifically to the field of siphon flushes.

State of the art

Patent CH172010 is known in the state of the art, describing a flushing tank, comprising a water supply pipe supplying an injection valve and a float valve. The two valves, namely an injection valve and a valve extended by a float are arranged in a common housing which has a channel connected to the same water supply line and leading to the two valve seats. The two valves are actuated mechanically, the actuating means being coupled to one another to block the float valve at the moment when the means are actuated on the injection valve.

The siphon has several supply ducts working in parallel, each of them being supplied by at least one injector jet.

Patent BE498973 is also known, which describes a similar device. It relates to a toilet flushing device for latrines, comprising a raised tank, a fixed emptying siphon whose water inlet branch communicates with the tank, the water level, after filling, located below the curvature of the aforementioned siphon, a control mechanism of a float and a valve placed on a pipe, supply and actuated by a member integral with this float. The aforementioned supply pipe opens into the inlet branch of the siphon. The float is controlled by a mechanism consisting of a lever of the first type, one arm of which is terminated by a counterweight and the other arm of which is provided with a chain and a plate arranged on said lever.

Patent FR1338521 is also known, describing another example of a flush comprising a tank fitted internally with a fixed siphon, below the priming point of which the water level is normally maintained by means of a float acting on the water inlet shut-off valve, priming of the siphon being obtained by momentarily raising this water level to a sufficient height.

Disadvantages of the prior art

All flushing systems are based on seals provided by synthetic materials more or less sensitive to the water chemistry of public water supply networks, in particular chlorine and limestone.

The so-called “direct flush” pressure systems (without tanks, those with tank remaining marginal on the market) use either a manual valve actuated by the application of force on a lever, or a solenoid valve. They have the advantage of concentrating the wear or deterioration generated by use or contact with water in a single point. If the manual action requires a certain force not always available to all users and can generate mechanical wear, it is accepted that these systems are generally robust therefore used in communities where the diameter required for direct flushing (minimum 20 mm) is more easily available and pressure losses in the building's internal network caused by the discharge required for flushing less penalizing than in the residential sector.

The solenoid valve has in particular the advantage of controlled wear because it is industrially calibrated for a given life determined by a relatively precisely known number of cycles.

Siphon drainage systems are recognized for their longevity thanks to their great simplicity and the impossibility of leakage due to the emptying device. However, over a long period of time, problems of wear on the actuating mechanisms are observed because the mass of water to be lifted requires a high control force, moreover not always compatible with all users (children, the elderly or disabilities) however that the diaphragm too, depending on its material, can deteriorate due to the composition of the water. These devices in their current forms are expensive - therefore not economically acceptable - to automate because of the weight of water to be lifted.

With regard to the tanks equipped for their evacuation with flaps / valves, more easily automated due to the less weight to be mobilized, the system is made up of manually operated plastic parts, not very compatible with intensive use, including wear. or carelessness can cause disassembly or breakage, and the sealing is ensured by rubber seals or silicones, the gradual deterioration of which is observed by dissolution, stiffening or swelling leading to leaks, initially not detectable but of which it is known that the lost volumes can be significant due to the continuous flow.

Moreover, whether the evacuation of the tanks is by valve or by siphon, the tanks all also include a mechanical filling device of the float valve type based on the sealing of rubbers or silicones, the deterioration of which is also observed here. progressive by dissolution, stiffening, swelling or even rupture for the finest elements. The malfunction of these float valves causes the tank to fill beyond its overflow and therefore a loss of water.

Finally, if the repair of filling or emptying devices can be as simple as changing a seal, it is not necessarily within the reach of all users who then have to call a professional with an intervention time, not to mention that spare parts are not always easily or locally available which leads, only for a simple matter of gasket, often to a change of system, therefore a waste in terms of the environment.

Solution provided by the invention

The present invention aims to remedy these drawbacks and to propose an alternative which is significantly more durable, more reliable and less restrictive in terms of maintenance by reducing seals in contact with water and moving parts susceptible to wear. To this end, the invention relates, according to its most general meaning, to a flushing device in accordance with claim 1. It further aims to provide an automatable solution in line with home automation and the technical management of buildings which offer the user more possibilities than non-automated, non-connected manual systems.

These objectives will be achieved by using the operating pressure of the water supply network to create a propellant jet in the upper part of the reservoir respecting the principle of the overflow backflow preventer and by proposing devices and arrangements facilitating the priming of a siphon.

To this end, the invention relates in particular to a flushing device comprising at least one tank associated with at least one siphon having an entry point in the lower part or on the bottom of said tank, and at least one supply means. placed above the level of the overflow of the reservoir so as to constitute an overflow backflow preventer, characterized in that the waiting level of the reservoir is located at a level close to or equivalent to that of the lower internal wall of the siphon neck located lowest and characterized in that said siphon is formed by a fixed structure relative to said tank and in that said supply means is controlled either manually or by at least one solenoid valve, controlled by an electronic card receiving a on the one hand a signal from a detector of the water level in the tank and, on the other hand, a trigger signal by the user aimed at priming the siphon. By siphon "formed by a structure fixed relative to said tank" is meant, within the meaning of the present patent, a device with one or more conduits, the necks of which are or are not placed at the same level, using the principle of the siphon to empty the tank. and benefiting or not from intrinsic arrangements aimed at facilitating its initiation, namely: on all or part of the internal walls of this siphon and in particular at its neck, structures spaced a few millimeters apart, the profile of which is square, rectangle , rounded, ogive or "volcano", triangular or trapezoidal, perpendicular or oblique with respect to the flow, or even such helical structures (of the thread type) and whose height with respect to the walls is also a few millimeters; that is to say any shape suitable for reinforcing the "edge" effect when the water rises in the siphon;

- a neck whose internal passage height is equal to the useful outlet diameter or is a fraction of this diameter, this diameter being determined by the flow rate necessary for an effective flushing of the toilet at the level of the bowl, in such a way that that the total area of the vertical section of the internal passage of the neck of the siphon is preferably equal to or slightly greater than or slightly less than the area of the section of the duct or of the outlet opening to the bowl.

This fixed siphonic device can take any shape or position inside or outside of said reservoir allowing it to empty the latter after a single priming by the supply means.

By "supply means" is meant, within the meaning of the present patent, a nozzle (or a simple end of pipe) connected to a water supply network under operating pressure and allowing either the filling of the tank or the 'priming siphon, i.e. both functions. To perform these functions, a valve or a solenoid valve is located upstream of the pipe arriving at the tank. The supply means may consist of a nozzle, or of an assembly comprising a nozzle. The outlet orifice of the nozzle is fitted with a device intended to conduct the residual water by gravity after use to a part where any scaling does not risk having an impact on the shape of the jet produced. The nozzle may have a slanted outlet orifice.

According to particular embodiments of the invention, the toilet flush also has one of the following additional characteristics, taken alone or in any technically compatible combination:

- Said siphon is formed by a plurality of conduits forming a cylindrical, ellipsoidal, cubic or parallelepipedic structure;

- Said siphon is formed by a plurality of conduits forming a structure of one or more parallelepipeds;

- Said siphon is formed by a plurality of conduits of the same diameter or of various diameters;

- Said siphon is formed by a plurality of conduits, the necks of which may or may not be placed at the same level but are initiated simultaneously;

- When the siphon is formed by a plurality of distant conduits, a common manifold located below the tank brings together the descending conduits of the siphon in a conduit towards the bowl;

- the inlet branch of said siphon comprises a portion which has a reduction in its diameter creating a acceleration additional to that impelled by the priming flow;

- Said siphon is formed by a tubular ring with a single circular or ellipsoidal neck passage;

- Said tubular ring has partitions or internal structures allowing the joining of its different walls;

- Said electronic card comprises a timer controlling the opening of said solenoid valve for a predetermined time producing a priming flow by the supply means in response to a trigger signal;

said level detector is a weight detection device;

- The flush has a plurality of reservoirs in that the outlets of the siphons open into a common manifold of the "nozzle" type equipped with one or more vents;

- The inlet of said siphon is made in the bottom of the tank so as to renew almost all of the water therein and allow the priming flow to have a direct impact on the water level in the branch of siphon inlet;

- The bottom of the reservoir has a sloping, concave, convex, conical ogive or "volcano" shape allowing, by the effect of gravity, maximum evacuation of the water contained in said reservoir and therefore its renewal and also allowing to guide the priming flow towards the inlet of the siphon while reducing the pressure drops;

- The bottom of the tank has a shape allowing the guidance of the priming flow towards the inlet of the siphon; - The bottom of the tank has a shape allowing all the water in the tank to be sucked up by the inlet branch of the siphon;

- the bottom of the reservoir has a sloping, convex, conical, pointed or "volcano" shape creating a channel into which the siphon entry opens;

- Said reservoir comprises a device for guiding the priming flow towards the inlet of the siphon;

- Said reservoir comprises a conduit for guiding the priming flow so as to bring this flow with a minimum of pressure drops towards the inlet of the siphon;

- Said reservoir comprises a conduit for guiding the priming flow towards the inlet of the siphon, the upper part of which is immersed under the stream when the reservoir is full, so as to benefit from an effect of drive when priming flow is activated;

- In order to facilitate the filling of the neck of the siphon and its priming, said reservoir has a device for guiding the priming flow towards the inlet of the siphon, the upper part of which is submerged but close to the stream when the reservoir is filled to take advantage of a ripple effect when the priming flow is activated, in the form of a flared tube in its lower part which is parallel to the bottom or follows the shape of the bottom of the tank and stops on approach the inlet of the siphon;

- In order to facilitate the filling of the neck of the siphon and its priming, said reservoir has a device for guiding the priming flow towards the inlets of the siphon consisting of a plurality of conduits, the upper part of which is submerged but close to the wire of water when the tank is filled to enjoy a ripple effect, in the form of a vertical pipe separating in as many conduits parallel to the bottom or according to the shape of the bottom of the tank, these interrupting when approaching the inlets of the siphon;

Said reservoir comprises a conduit for guiding the priming flow, a portion of which has a reduction in its diameter creating an additional acceleration to that impelled by the priming flow;

- Said device or the guide duct is secured to the tank by partitions or support structures;

- Said tank has a partition isolating the priming flow from the rest of the water in the tank while allowing this water to be emptied by the siphon thanks to a passage made for the water near the inlet of the siphon ;

- Said reservoir comprises, when the priming and filling of the reservoir are provided by the same nozzle, a flap with float allowing, when this flap is in the raised position due to the action of its float, to allow the flow of d 'priming towards the inlet of the siphon but, once the tank is empty and the shutter released from the action of its float and has fallen, directing the filling flow elsewhere than towards the inlet of the siphon;

- Said tank accommodates a float that does not seal with the edges of said tank or the edges of the partition of said tank in which it is placed, intended to facilitate the priming of the siphon by plunging under the action of the priming jet thus acting in the manner of a piston whose stroke is stopped by a stop device so as to allow the water from the reservoir to be sucked into the inlet of the siphon; - Said float is equipped with a ballasting device aimed at maintaining its attitude;

- Said float is equipped with a ballasting device aimed at keeping it in the standby position under the flow of water;

- Said float has a flat upper face;

- Said float has a totally or partially convex upper face;

- Said float has a hollow or a flat on its upper face so as to receive the priming flow;

- Said float has a lower face with a rim forming a bell and making it possible, during its immersion under the action of the priming flow, to limit the rise of water towards the surface of the tank;

- The top of said reservoir has a sealed cover having an opening directly above the supply means so as to allow the water from the priming and filling flows to pass as well as the air required by the suction created by the emptying the tank or the excess air when filling it, the underside of which is placed at the holding level of the tank located at a level close to or equivalent to that of the base of the siphon neck located the lowest in order, when priming flow, to avoid a rise in the water level in the tank and to transfer this rise in the water level to the neck of the siphon through which the water can easily escape. This cover may include a device aimed at preventing an overflow during variations in level due to the priming and filling flow. Detailed description of non-limiting embodiments

The invention will be better understood on reading the following description, with reference to the appended drawings relating to non-limiting embodiments, where:

- Figure 1 shows a longitudinal sectional view of a flush according to the present invention comprising a siphon consisting of multiple separate conduits;

- Figure 2 shows a cross-sectional view of the toilet flush shown in Figure 1;

- Figure 3 shows a longitudinal sectional view of a flush according to the present invention comprising an external siphon consisting of multiple ducts grouped together;

- Figure 4 shows a longitudinal sectional view of a flush according to the present invention comprising two internal siphons consisting of a single duct each.

Description of the flush shown in Figures 1 and

2

The toilet flush comprises a tank (100), of cylindrical shape in the example described, made of plastic, for example polycarbonate. The bottom of the reservoir has in the center a cone (105) defining a peripheral channel (120). The conical part can be filled with a sound and / or thermal insulator.

The tubular wall (110) defines a reserve volume of water supplied by a solenoid valve (200). In the example described, the reservoir is closed by a cover (140). Said solenoid valve (200) comprises, in known manner, a valve (210) closed at rest by the effect of a spring but moved by a magnetic core (220) when a wound stator (225) is supplied with an electric current. .

The flush has an entry point in the lower part or on the bottom of said tank, and at least one supply means placed above the level of the overflow of the tank so as to constitute an overflow backflow preventer.

The reservoir (100) is also surrounded by a peripheral siphon (300) formed by a plurality of internal conduits (310 to 333) opening out at the upper part (336, 337), the necks of all the conduits being placed at the bottom. same height for simultaneous priming with external ducts (340 to 363). The interior conduits (310 to 333) have frontal openings (334, 335) opening into the channel (120). The outer ducts (340 to 363) open at their lower parts (364, 365) into a manifold (370) supplying the discharge duct (380).

A weight sensor, for example a piezoelectric probe (400), provides an electrical signal depending on the weight of the tank. It makes it possible to estimate the volume of water contained in the tank and supplies a signal to an electronic card controlling the solenoid valve (200). Of course, any other form of sensor, for example optical or electrical, or electromechanical with a float, can be envisaged. Description of the flush shown in figure 3

The flush comprises a tank (100) equipped with an external siphon (301) made up of a plurality of grouped conduits whose inlets (375, 376 and 377) are placed on the bottom of the tank, with a cover (140) having an orifice surmounted by a solenoid valve (200), a guiding device (500) of the priming flow having a reduction in its diameter and a level detector (400).

The guide device (500) has in its lower part a flap with float (510) mounted on a pivot (511) so that, when the tank is full, the flap is in the raised position and allows the flow to pass during the triggering of the flush by the effect of a contactor and, when the tank has emptied, the flap is in the low position (512, dotted in the figure) sufficiently inclined to direct the filling flow towards the inside of the tank and not towards the inlets of the siphon conduits (375, 376, 377).

The configuration of the siphon with its multiple conduits of an appropriate section and their inlets (375, 376,

377) located on the bottom of the tank which has a funnel shape is intended to allow maximum emptying of the tank without reflux of water from the rising parts of the siphon conduits. This configuration ensures that the water in the reservoir is renewed, thus limiting the development of microorganisms. Description of the flush shown in figure 4

The flush comprises a tank (100) equipped with two siphons (302, 303) each consisting of a single duct whose round section inlets (390, 393) are placed at different levels determined by the volume of water to be used. A vent (600) allows air to be supplied to the level of the outlets (392, 395) of the siphons which meet before the evacuation duct towards the bowl (380) and thus prevents the unexpected priming of the siphon which is not used. A float level detector (405) allows the management of the filling of the tank.

In this exemplary embodiment, the filling is provided by a solenoid valve (200) via the nozzle (130) and via a conduit (510) for guiding the filling flow to limit the noise on the wall and the bottom. . The solenoid valve (201) (activated by the appropriate selection of a contactor) ensures the priming of the siphon (301) via the nozzle (131) via a guide duct (501) bringing the flow of 'priming at the inlet (390) of the siphon in order to cause, by a driving effect, a sudden rise in water up to the high level (339) of the neck of the siphon (391) having a section flattened with respect to the round section of the entrance (390) but an equivalent area.

To use a smaller volume of water, the solenoid valve (202) (activated by the appropriate selection of a contactor) ensures the priming of the siphon (302) through the nozzle (132) via a guide duct (502) bringing the priming flow to the inlet (393) of the siphon in order to cause, by a driving effect, a sudden rise in water up to the high level (339) of the neck of the siphon (394). Flush operation.

When the tank (100) is empty, the level detector (400 in figures 1 and 3, 405 in figure 4) detects a low level or a low weight, and controls the activation of the solenoid valve (200), closed at rest. The water inlet ensures the filling of the reservoir (100). When the level reaches a level (338) very close to the bottom of the siphon neck (336, 337 in figures 1 and 3, 390, 394 in figure 4), the level detector (400 in figures 1 and 3, 405 in figure 4) controls the stopping of the supply by the solenoid valve (200). In the event of loss of liquid, for example by evaporation, the detector (400) controls the opening of the solenoid valve (200) to ensure the leveling. When activated by a control button (electrical contactor of the "push-button" type, for example) a timing module controls the opening of the solenoid valve (200 in figures 1 and 3, 201 or

202 in FIG. 4) for a predetermined time of a few tenths of a second calculated to ensure the filling of the neck of the duct (s) of the siphon used up to a level (339) allowing it to be primed.

Variants of realization

The flush is shown in the examples Figures 1 and 3 with a single tank equipped with a single siphon. It can also, in the spirit of Figure 4, consist of a single tank equipped with several siphons whose inlet branches have their mouths at different levels to allow various volumes. It can, moreover, consist of several reservoirs each equipped with their own siphon, with a common manifold, the reservoirs having the same capacity or different capacities to allow the activation and implementation of a suitable volume. In this case, the contactor can have several positions to select the useful volume by bringing into play the corresponding number of reservoirs.

The structure of the siphon can take different forms, and possibly be included inside the tank, in this case having a bottom through which the lower end or ends of the siphon pass.

The geometry of the reservoir is presented in the above example in a cylindrical form. It can take other shapes, for example with a rectangular section, with a flared shape, or even prismatic.

The external or downward flow conduits of the siphon arriving at the collector can be oblique over all or part of their height to generate a vortex and reduce flow noise.

The smallest dimension of the cross section of the ducts constituting the siphon is typically greater than or equal to 8 millimeters, or even less than 8 millimeters with, in the long term, a risk of clogging by scaling or by sludge when the passage is too small. It should be noted that an additional advantage to the use of ducts of small cross-section is that there is, in this case, no reflux of the water sucked in when the siphon is defused, thus allowing a total renewal. of the water in the tank.

The largest dimension of the cross section of the pipe constituting the siphon may correspond to the diameter of the discharge pipe to the bowl, provided that the throat of the siphon has an internal height in line with the force of the priming flow and its possible facilitation arrangements.

The presence of a tight cover on the tank helps to prevent, during the action of the priming flow, a rise in the water level in the tank in general, the rise in the water level having to occur in the tank. inlet branch to submerge the siphon neck and trigger the emptying of the tank. The cover is not necessary in the case where a device for guiding the priming flow is sufficiently effective to prevent a rise in the general level of the water in the tank.

The level detector can be constituted by a switch placed under the tank, with a calibrated spring to compensate for the weight of the tank filled to a level below the waiting level (338), or a magnetic float, or a piezoelectric sensor, or a pressure switch, or a float coupled to a switch, or any type of probe suitable for detecting the level or the volume or the weight of water.

In the event of a plurality of reservoirs, one or more vents must be provided at the inlets or at a point of the common manifold under the reservoirs to prevent, by suction effect, an unexpected priming of the non-activated reservoirs.

In the event of a plurality of siphons in a tank, one or more vents must be provided under the tank at the level where the descending branches of the siphons meet in the discharge duct towards the bowl to avoid, by suction effect, priming. unexpected siphons not activated. The electrical supply can be provided by a low current circuit, a battery, a cell, or an energy recuperator such as a dynamo driven by the water flow, associated with a supercapacitor or a reserve battery.

Triggering can be provided by a wired or radio switch, or a tactile or capacitive switch or even a presence detector.

The electronic card receives the user trigger signals and the filling signals. It controls the solenoid valves corresponding to the priming or filling nozzles and manages a possible solenoid valve failure. It can control the transmission of a digital message (for example, LED lighting visible to the user) in the event of a low battery or in the event of a solenoid valve failure.

Claims

1 - Flush with at least one tank

(100) associated with at least one siphon (300 in Figures 1 and 3, 301 and 302 in Figure 4) formed by a fixed structure relative to said reservoir (100) and at least one supply means (130 in Figures 1, 3 and 4, 131 and 132 in figure 4) for filling the reservoir (100), characterized in that said supply means is controlled by at least one valve or a solenoid valve (200 in figures 1, 3 and 4, 201 and 202 in FIG. 4) controlled by an electronic card receiving on the one hand a signal from a detector (400) of the water level in the tank (100) and on the other hand a triggering signal for the priming of the tank. siphon.

2 Flush according to claim 1 characterized in that said siphon has an entry point in the lower part or on the bottom of said tank, and at least one supply means placed above the level of the overflow of the tank.

3 - Flush according to claim 1 characterized in that the standby level of said reservoir is located at a level corresponding to that of the lower internal wall of the neck of said siphon.

4 - Flush according to claim 1 characterized in that said siphon consists of several conduits. 5 - Flush according to claim 1 characterized in that said siphon has on at least part of its internal walls non-contiguous structures, or a helical structure, to enhance the edge effect during the rise of the 'water.

6 - Flush according to claim 1 characterized in that said siphon has a neck whose internal passage height is equal to the useful outlet diameter or is a fraction of this diameter, so that the total area of the vertical section of the internal passage of the neck of the siphon is preferably equal to or slightly greater than or slightly less than the area of the section of the duct or of the outlet opening to the bowl.

7 - Flush according to claim 1 characterized in that said supply means is constituted by at least one nozzle connected by a conduit to a pressurized water supply network and allowing, through the opening or the closing a valve or an upstream solenoid valve, either filling the tank, or priming the siphon, or both functions.

8 - Flush according to claim 1 characterized in that said siphon is formed by a plurality of conduits forming a cylindrical, ellipsoidal, cubic, parallelepipedal structure or consisting of several parallelepipeds and comprising a common manifold located below the tank bringing together the descending ducts of the siphon into an outlet duct towards the bowl. 9 toilet flush according to claim 1 characterized in that said siphon is formed by a tubular ring having partitions or internal structures allowing the joining of its various walls and a single circular or ellipsoidal neck passage.

10 - Flush according to claim 1 characterized in that the inlet branch of said siphon comprises a portion which forms an eductor.

11 - Flush according to claim 1 characterized in that said level detector is a weight detection device.

12 - Flush according to claim 1 characterized in that, when it comprises a plurality of reservoirs, the descending branches of the siphons open into a common manifold of the "nozzle" type equipped with one or more vents.

13 - Flush according to claim 1 characterized in that the bottom of the tank has a shape allowing the guidance of the priming flow towards the inlet of the siphon with a minimum of pressure drops.

14 - Flush according to claim 1 characterized in that the bottom of the tank has a shape allowing all the water in the tank to be emptied through the inlet branch of the siphon. 15 - Flush according to claim 1 characterized in that said reservoir comprises a device for guiding the priming flow so as to bring this flow with a minimum of pressure drops towards the inlet of the siphon, a device which can take the shape of a duct, the upper part of which may or may not be submerged under the stream when the tank is full.

16 - Flush according to claim 1 characterized in that said reservoir comprises a conduit for guiding the priming flow, a portion of which is an eductor.

17 - Flush according to claim 1 characterized in that said reservoir has a device for guiding the priming flow towards the inlet of the siphon, the upper part of which is submerged but close to the stream when the reservoir is filled, in the form of a flared tube in its lower part which is parallel to the bottom or follows the shape of the bottom of the tank and stops when approaching the inlet of the siphon.

18 - Flush according to claim 1 characterized in that said reservoir has a device for guiding the priming flow to the inlets of the siphon consisting of a plurality of conduits, the upper part of which is submerged but close to the wire of water when the tank is full, in the form of a vertical duct separating into as many ducts parallel to the bottom or according to the shape of the bottom of the tank, these interrupting when approaching the siphon inlets.

19 Flush according to claim 1 characterized in that said reservoir has a partition isolating the priming flow from the rest of the water in the tank while allowing this water to be emptied by the siphon by means of a passage provided for the water near the inlet of the siphon.

20 - Flush according to claim 1 characterized in that said reservoir comprises, when the priming and filling of the reservoir are provided by the same supply means, a flap with float allowing, when this flap is in the raised position due to the action of its float, to allow the priming flow to pass towards the inlet of the siphon but, once the tank is empty and the shutter released from the action of its float and has fallen, to direct the flow of filling elsewhere than towards the siphon inlet.

21 - Flush according to claim 1 characterized in that said tank accommodates a ballasted float or not, plunging under the action of the priming flow, whose shape of the cross section is that of the cross section of said tank or of the partition of said tank in which it is placed but the dimensions of which are slightly smaller, the upper face of which may be flat or convex and may have a hollow corresponding to the impact of the priming flow, the lower face of which may be flat or concave and may be provided with rims so as to constitute a bell, and the course of which is stopped by a stop device so as to allow the water from the reservoir to be sucked into the inlet of the siphon.

22 - Flush according to claim 1 characterized in that the top of said tank comprises a sealed cover having an opening in line with the supply means so as to allow the water from the priming and filling flows to pass as well as the air required by the suction created by the emptying of the tank or the air excess when filling, the lower face of which is placed at the holding level of the reservoir located at a level close to or equivalent to that of the lower internal wall of the siphon neck located the lowest so, during the priming flow, to avoid a rise in the water level in the tank and to postpone this rise in the water level towards the neck of the siphon through which the water can easily escape. This cover may include a device aimed at preventing an overflow during variations in level due to the priming and filling flow.

23 - Flush according to claim 1 characterized in that said supply means may consist of a nozzle, or of an assembly comprising a nozzle, the outlet of which is equipped with a device for lead by gravity the residual water after use to a part where any scaling will preferentially concentrate.

24 - Flush according to claim 23 characterized in that said supply means may consist of a nozzle, or of an assembly comprising a nozzle, the outlet orifice of which has a bias.