ES2200097T3 - A DRIVING MECHANISM FOR WATER DISCHARGE SYSTEMS FOR Odorless toilets. - Google Patents

Abstract

The invention relates to an actuating mechanism for a flushing system having an outlet device (11) arranged in a flush cistern (10) and an inlet device (48). This inlet device has a float device (40) for controlling the supply of liquid into the flush cistern (10) by an inlet valve (48) included in the inlet device (48). The float (40) of said float device is operatively connected to the inlet valve (48) via a link system (47) for opening and closing the inlet valve (48) depending on the liquid level in the flush cistern. The outlet device (11) of the actuating mechanism comprises a release means (49) for opening the outlet valve (11) of the outlet device. According to the invention, the actuating mechanism has a locking device (54-62) for preventing the initiation of a new flushing operation before the flush cistern (10) has again been filled with liquid to above a predetermined minimum level. <IMAGE>

Description

A drive mechanism for systems water discharge for toilet toilets.

The present invention relates to toilets toilets, and a discharge system to wash them, which allows essentially reduce the force required to initiate a download operation by using a download system based on a siphon. More particularly, the invention relates to a drive mechanism especially very suitable for use in said new and improved discharge system to wash the toilet.

The document GB-A-2,205,595, on which the preamble of claim 1, describes a discharge system for toilets that have a double siphon submerged in a cistern Download This siphon has an almost sinuous conduit, with four juxtaposed vertical duct sections and curvatures or elbows in U that interconnect successively the sections of the duct. The center elbow looks down, and interconnects the ends lower of the two sections of central duct, while the two outer U-elbows look up and connect the upper ends of the central duct sections to the upper ends of the outer duct sections. East duct, bent approximately sinusoidal, is arranged in a discharge cistern, and is completely immersed in the water when said cistern is full. The first vertical section of the duct acts as the siphon suction tube, and the last section vertical duct acts as a siphon outlet tube, and is connected to a water discharge ramp, at the upper end of the toilet From the upper end of the first U-elbow that look up, also extends a ventilation tube U-bent directed downwards, which at the upper end of its other U-section is connected to the third U-elbow that looks up, at a certain distance below the crest of this elbow in U. This ventilation tube, shaped with curvature U, acts as a water retainer in the initial position of the water discharge system, when the tank is full. For start the discharge operation, the water is removed from the retainer her by means of a hollow ball or air ball that is connected to the lower U-section of the bent ventilation tube U, and when compressed increases the air pressure in the system, displaces the water in its retainer, and evacuates it to the inside the siphon outlet tube. In this way it is established a communication between the upper end of the first U-bend that  look up and the third U-elbow that looks up from so that the air retained in the first U-elbow that looks towards above can be evacuated through the vent tube, with what that the entire loop of the sinuous conduit is intended for fill with water, so that the siphon function is started to suction evacuate most of the water from the system discharge into the outlet tube. When you have sucked a maximum amount of water from the discharge tank, and air the leak inside the double siphon begins, a certain amount of water will remain in the double siphon, and also in the tube of U-folded ventilation. When the water level rises after in the cistern, the water remains in the double siphon although the water levels in the first, second, and third move vertically with each other. The system includes also another U-bent conduit that is connected to the crest of the third U-folded duct of the double siphon, and extends up above the maximum water level in the cistern of discharge, and opens on a level corresponding to the minimum water provided in the discharge tank. When the water level of the cistern has descended below the lower end of this U-bent duct, the air is sucked into the siphon double, and consequently the download operation is interrupted.

The descriptive report of Danish patent no. DK-B-57.606, describes a cistern of discharge that also uses a type of double siphon. In this case, a download mechanism is provided that has a water collector A piston is submerged in this water collector drive, which when raised, the level of water in the manifold, and thereby reduces the pressure of the column of Water. As a result, the water collector liquid will no longer be capable of withstanding the pressure of the air retained in the double siphon, and the water retention function will cease like this, so that the air of the first U-elbow that looks up from the double siphon is expelled into the atmosphere, and the siphon function begins. The drive mechanism is arranged in a compartment facing up, at the inlet end of this U-bend. However, this mechanism has not been shown to be completely satisfactory operation, and often have observed difficulties in establishing and maintaining siphon function This is probably due to the fact that air can penetrate the mechanism between the piston of drive and the wall of the water collector section where the piston is arranged. As a result, there is a risk of leakage of air inside the siphon, which harms or interrupts the effect of this one. Similarly, the placement of the mechanism of drive on top of the double siphon inlet section, brings I get certain disadvantages, since the air that comes out must flow to countercurrent with respect to incoming discharge water from the discharge tank. This also does more. difficult to completely remove the air from the first looking elbow up the double siphon. In effect, the remaining air results Very detrimental to the siphon's performance.

Another example of a drive mechanism is shown in document US-A-1 792 588.

The system shown and described in the document GB-A-2,205,595 is an improvement with with respect to siphon systems of the prior art, but it still has certain disadvantages, which have meant that the system has not be as successful as you would like. One of these disadvantages it is the poor function of the system, which depends, at least partially,  of the difficulties of completely evacuating the air retained in The first elbow that looks up. Another disadvantage is the design of the drive mechanism, that is, the use of a ball hollow or air ball to be compressed to provide the displacement and evacuation of the water remaining in the tube ventilation, which serves as a water collector. As in others known siphon-based discharge systems, this technique of drive requires substantial forces to start the water discharge operation. First, it has been proven that it is difficult to completely displace and remove water from the tube ventilation with the help of the hollow ball, and if the water is not completely withdrawn, the remaining avoids, or at least counteracts the evacuation of retained or blocked air in the first elbow that looks upwards. Second, it is often difficult to do that the user changes their habits, which consist of starting the water discharge operation by pressing a button, lifting the stem of a valve, or by pulling a chain from the valve Download

An object of the present invention is provide an improvement of water discharge systems described in the documents GB-A-2,205,595, and DK-B-57.606. This and other objects of the invention are achieved by means of a discharge system of the water, which has the characteristics set forth in the claim 1st. The subclaims define embodiments especially advantageous of the invention.

In summary, the invention relates to a drive mechanism for a discharge system that has a output device arranged in a discharge tank, and a input device This input device has a floating device to control the liquid supply inside of the discharge tank by means of an inlet valve included in the input device. The said float floating device is operatively connected to the valve entry through a link system, to open and close said inlet valve depending on the level of the liquid in the discharge tank. The device's output device drive comprises release means to open the outlet valve of the outlet device. According to the invention, the drive mechanism has a mechanism of blocking to prevent the initiation of a new operation of discharge before the tank has been filled again with liquid up to a predetermined minimum level.

The invention will be described below with more detail with reference to the accompanying drawings, which show some preferred embodiments of it. However, such embodiments should not be considered as limiting of the invention.

Figures 1 to 6 illustrate, schematically, the principle of the invention and its function in the different phases of an evacuation procedure.

Figure 7 is a vertical section of a specific implementation of a water discharge system for wash, with a drive mechanism according to the invention.

Figure 8 shows the embodiment of Figure 7 in the state corresponding to figure 3.

Figure 9 shows the embodiment of Figure 7 in the state corresponding to figure 5.

Figure 10 shows the embodiment of the figure 7 from above.

Figure 11 is a section taken along the line XI-XI of figure 7.

Figure 12 shows the embodiment of the figure 7 from the left, with respect to said figure 7.

Figure 13 shows the embodiment of the figure 7 from the right, with respect to said figure 7.

Figure 14 shows the embodiment of the figure 7 in side view from the front, with respect to the figure 7.

Figure 15 is a section taken along the line XV-XV of figure 14.

Figure 16 shows parts of another embodiment of a water discharge system with a mechanism of drive according to the invention, and this figure corresponds to the position adopted in fig. 7.

Figure 17 is a view similar to that of the Figure 8, but shows said other embodiment of the invention.

Figure 18 is a view similar to that of the Figure 9, but shows said other embodiment of the invention.

Figures 1 to 6 schematically show a water discharge system according to the present invention. A device 11 is immersed in a discharge tank 10 output Said output device is designed as a siphon double, in the form of extended duct approximately sinusoidal, which has four sections of the duct juxtaposed 12, 13, 14, and 15, and the U-elbows 16, 17, 18 that interconnect between yes successively the sections of the duct. The central U elbow 17 look down, and connect the lower ends of the two central sections 13, 14 of the duct. The two U-elbows outer 16, 18 look up, and connect the ends upper of the two central sections 13, 14 of the duct, to the upper ends of the outer sections 12, 15 of the duct. The first vertical section 12 of the duct is intended to act as siphon suction tube. The last vertical section 15 of the duct is intended to act as a siphon outlet tube, and is connected in a customary way to a discharge ramp of water (not shown) at the top end of a cup toilet.

The water discharge system also has a ventilation tube 19 that serves to evacuate the air that, when the discharge tank 10 is filled with liquid, it remains held at the first U-elbow 16 that looks up from the siphon double. One end of the vent tube 19 is connected to a point on the downstream side of this U-bend, and extends upward above the level of the crests of the elbows at U 16, 18 looking up, for connection at the other end to a drive mechanism 20. This mechanism includes a valve of non-return 21, comprising a piston chamber 22 substantially vertical, in which a piston is arranged initiator 23 for vertical movement. The upper end of the piston chamber 22 may be connected to ambient air in a point above the maximum water level 24 of the cistern of download. The piston chamber also has a sump 25 of liquid, located below the vent tube opening 19 existing in said piston chamber 22. Liquid sump has sufficient volume to hold the liquid that remains in the initiator piston chamber 22 and in the tube of ventilation 19, when the discharge tank 10 is full. In the upper end, the starter piston 23 and the chamber 22 of said piston are designed so that a coupling occurs air and liquid tight inside a flared part 26 conically Alternatively, a shutter can be used special between an outwardly directed tab and a surface of  coupling, as will be described later. This shutter, inside the conically flared part, or a similar shutter, Provides the desired non-return valve function. The starter piston 23 and piston chamber 22 are designed of so that when said starter piston is lifted, it will be sucked air inside said chamber 22 of the initiating piston, and in Consequently, the liquid present in the starter piston chamber and in the vent tube it will flow down into the 25 liquid sump. As a result, the air retained in the first elbow in U 16, in the initial position (figure 1) can be evacuated through the vent tube 19 and the valve non-return 21.

Figures 1 to 6 show the sequence of the Different phases of operation. Figure 1 shows the discharge system in the initial position, in which the tank 10 is filled with liquid and the starter piston 23 is in its lower position, in which the flared part 26 engages sealed to the starter piston chamber. In this position, there is air retained in the U-elbow 16 and in the tube ventilation 19. Overpressure prevails as a result of differences between the levels 31, 31 'of liquid in the first three sections 12, 13, 14 of the duct.

To start the discharge operation, the piston initiator 23 rises so that the air passes from above to inside the chamber 22 of said starter piston, so that the liquid retained in said chamber flow down into the sump 25 of liquid, to expose the opening of the ventilation tube 19. As a result, the air retained at the elbow at U 16 will be discharged by the pressure of the liquid through the starter piston chamber. Irruption of resulting liquid causes said liquid to fill the first elbow in U 16 of the double siphon, and then also the entire siphon, so that the siphon function starts and the liquid is discharged from the tank. Figure 3 shows the state in which the first three sections 12, 13, 14 of the duct are completely filled with liquid. Continuous suction of liquid inside the double siphon it will make it completely fill, as well as the tube of ventilation 19 and the chamber 22 of the starter piston (figure 4). In this position, the starter piston 23 has been returned to its initial position, with the shutter function of the valve non-return inside the flared part 26.

Figure 5 shows the next phase, when download continues. During this phase, there is a negative pressure in the double siphon, and therefore also in the ventilation pipe 19 and in chamber 22 of the starter piston. Air suction at inside of the double siphon, through the piston chamber initiator, is avoided by the function of the valve non-return mentioned above. Water discharge continues until that air is sucked into the double siphon, through the entrance of section 12 of the duct. Figure 6 shows this position. If more discharge fluid is desired small that corresponds to the lower end of the first section of conduit, it is possible to arrange holes at different levels than along said first section of the duct, to achieve, by For example, a quantity of discharge liquid of 4 or 6 liters. In In any case, the siphon effect is interrupted when sucks air into the first section of the duct. When this happens, a certain amount of liquid will remain in the second U-elbow 17. When filling the discharge tank with liquid fresh discharge, said column of liquid will move to eventually occupy the position shown in figure 1.

A main advantage of this system is that the Download operation starts easily and requires only one very light force, since the liquid column in chamber 22 of the piston, on the inlet 29 of the vent tube 19, substantially unbalances the overpressure represented by the difference in level between liquid surfaces 31 and 31 '. In addition, the system is advantageous as long as it has been dispensed with. of the hollow starter ball used in the document GB-A-2,205,595, and the operation of download can be initiated according to traditional means, that is, by lifting a piston or by pressing on a button that lifts said piston. Through position selected from the inlet 29 of the vent tube 19, they are avoided also the disadvantages inherent in the device of the technique previous according to the document GB-A-2,205,595, as the air is removed at a point downstream of the crest of the elbow in U. In this way an improved air withdrawal is achieved or complete, especially if the duct sections are designed to improve laminar flow.

Figure 7 shows a preferred embodiment of the discharge system, in accordance with the present invention. In this figure, the different components are shown in the same positions as in figure 1. The discharge system is mounted at the bottom 27 of a discharge tank. The siphon double 11 has its four sections 12, 13, 14, 15 of the duct arranged substantially vertically, next to each other. How  it is deduced from figure 11, the conduit sections have a flattened cross section, to promote laminar flow. Do not However, the shape of the cross section does not need to be so flattened as shown in figure 11, but can be used also a square or oval cross section. In addition, the Double siphon flow passage is preferably designed with a reduced flow passage area from section 12 of the conduit to a location in section 15 of the conduit, with in order to improve the flow, increase its speed, and favor the laminar flow.

The last section of the duct or outlet pipe 15 is connected to an outlet sleeve 28, connected, in turn, to the conventional water discharge ramp (not shown) of the toilet toilet

As shown in Figure 7, the tube ventilation 19 is connected to the second section 13 of the duct in a point opposite the first section of the duct, and next to the upper end of the second section 13 of the duct, that is, at along the wall surface where air flows when Evacuate the retained air bubble. The reason for this placement is that the inlet 29 of the vent tube 19 must be arranged so far in the direction of downstream, that the air is completely displaced by the water flowing within section 12 from the duct, to the initiation of the discharge procedure. The outlet end of the vent tube 19 is connected to the piston chamber 22 at a point that is preferably located slightly below liquid levels 31 in the first and in the third section of the duct, in the initial position of the water discharge system (see figure 7).

In this preferred embodiment, the piston initiator 23 has an outwardly directed tab 32, which in the closed state of the non-return valve is coupled to one edge 33 in chamber 22 of the starter piston. If so required, the tab 32 may be provided with a shutter, with which attaches to edge 33. In the illustrated embodiment, piston 23 has  two floating bodies 34, whose purpose will be described with more detail below (figure 11). These floating bodies are arranged on the outside of the chamber 22 of the starter piston, and hang under the upper edge 33 of the chamber. Upper face The piston is equipped with a pin 35 on which it is mounted pivotally a locking latch 36, for movement pivoting between a locked position, indicated with lines continuous, and a release position indicated with lines of dots and strokes in figure 7. In the locked position, the locking surface 37 of the latch engages a surface of  stationary lock 37 of a fork 38. To limit the pivoting movement out of the locking latch, this one preferably has a projection 39 that stops the pivoting outward movement by coupling to the upper face of piston 23.

In the embodiment of Figure 7, the float 40 of the discharge system is designed as an open hood down, which is guided in a flotation chamber 41 to vertical movement in it. The camera 41 is connected so fixed to double siphon 11 and piston chamber 22. The camera Flotation 41 is intended to be filled with discharge liquid, what is achieved when the liquid, by filling the cistern of discharge, flows over the upper edge of the flotation chamber and descends between it and float 40. At the lower end of the flotation chamber is provided with a non-return valve 42  shaped pivotable valve plate mounted for movement pivoting around a pivot pin 43 adjacent to the edge upper flotation chamber. Check valve is inclined, so that it is forced to go down when is in its normal position, due to the force of gravity, to make contact with the side of the flotation chamber, and in sealing coupling with a valve seat 44. Through this arrangement, the flotation chamber will be evacuated successively as the level of liquid in the cistern of download go down. Moreover, the filling of the flotation chamber with discharge liquid is prevented until said liquid can flow over the upper edge of the chamber of floatation. This arrangement allows the discharge tank to be fill faster, and does not require gradual decline used to supply liquid during the final phase of the filling procedure

Float 40 has a right foot 45, in which upper end there is arranged a pivot pin 46. East pin is connected to a control arm 47 of a valve conventional inlet 48. Valve 48 is closed in position shown in figure 7, and open in the position shown in the figure 9.

To start the download operation, the drive mechanism of the embodiment of figure 7 has release means 49, which in this embodiment consist of a push button mechanism that has, at its lower end, an actuator 50 protruding laterally, and which is pushed elastically upwards by a spring unit 51. Said spring unit 51 may be integrally formed with components 49 and 50. The free end of the spring unit 51 is fixed to the body 53 of the mechanism adequately, by example, using the protruding pins 52. The body 53 is formed integrally with the fork 38, and thus forms A stationary element. In this stationary element is fixed a pivot pin 54. On said pivot pin 54 it is pivotally fixed at one end, a sensor lever 55. The other end of the sensor lever is designed as a follower of cam 56, which attaches to the upper face of float 40, and this face also serves as cam surface 57. Between the follower of cam 56 and pivot pin 54, sensor lever 55 has a pivot pin 58, on which a pivotally mounted swing arm 59 release. In this embodiment, the arm Oscillating is designed as a double arm lever, and engages to actuator 50 with one end 60, and to cam surface 62 on the locking latch 36 with the other end 61.

A downward pressure on the means of release 49, overcoming the action of spring 51, produces a swinging swing arm 59 release on clockwise direction with respect to figure 7, so that the locking latch 36 is released from its coupling of lock with fork 38, and is turned to its indicated position with dotted lines and strokes. This means that the starter piston 23 is released and lifted by its floating bodies 34, to the position shown in figure 8, in which the upper face of the starter piston becomes coupled to the fork 38.

Figure 8 shows only one position snapshot to illustrate the function of the mechanism. In this instantaneous position, piston 23 has been raised like this, so that the liquid retained in the piston chamber and in the tube of ventilation, can flow down into the sump 25 of liquid As a result, the air retained in the first elbow in U 36 and in parts of the second section 13 of the duct, it will flow to outside and will be evacuated through the vent tube 19 and the outdoor piston chamber 22, on the liquid surface 24 in cistern 10. This starts the siphon function, and the discharge liquid is discharged to the discharge ramp of the toilet, in the manner described above. When the liquid level in the discharge tank it descends gradually, it descends also the level of liquid in the flotation chamber 41, since the water can flow out through the valve non-return 42. In this way, the sensor lever 55 will pivot in clockwise direction with respect to figure 7. This also means that the vertical position of pin 58 of Pivoting is lowered in correspondence. The descent of the position of pivot pin 58 relative to pin of pivoting stationary 54 brings about that the oscillating arm 59 of release descend too. As a result, a gap will form between the end 60 of the swing arm and the actuator 50. Due to this gap, the download procedure cannot be initiated from  again until the liquid level in the download system The gap between components 50 and 60 is maintained during the entire filling procedure due to which float 40 remains in its lowest position (figure 9), until the water flows into the flotation chamber 41 a through the upper edge of said chamber, since the valve non-return 42 prevents water from flowing inside before it. However, flotation chamber 41 is not necessary for keep this lock function, which prevents new initiation of the water discharge operation. However, it is essential that the mechanism is designed so that the initiation of a new water discharge operation is not possible before the level of the liquid, in the discharge system, has come back to one position above the crest of the vent tube 19.

Figure 9 shows the positions of the components after the liquid level has dropped by amount such that floating bodies 34 are no longer capable of keep the starter piston 23 in an elevated position. As soon as said starter piston 23 has returned to the position shown in Figure 9, the non-return valve function is achieved, it is that is, the coupling between the flange 32 and the edge occurs upper chamber 22 of the piston. This function is favored. also by coupling the latch 36 to the fork 38. The floats 34 must be designed with a lifting power set so that the valve shutter function of non-return is achieved before the level of liquid in the discharge system has descended below the crest top of the vent tube 19. Indeed, it is essential that liquid remains in the vent tube and piston chamber, so that an air plug or seal remains in the U-elbow 16, when the discharge tank is being filled again with liquid.

Figures 7 to 15 show an embodiment preferred drive mechanism for the system water discharge according to the invention. However, the drive mechanism can also be designed differently, and a possible embodiment is illustrated in Figures 16 to 18. In in this case, there is no piece equivalent to lock latch 36, but the swing arm 59 release lifts the piston 23 directly, it attaches to a hook 63 and lifts it, whose hook it is directed laterally on the piston 23. As soon as the piston, through hook 63, has been lifted to remove the sealing coupling between tab 32 and the upper edge 33 of the chamber 22 of the starter piston, the bodies Floating 34 will assume its lifting power and lift the piston to the position shown in figure 17. Also in this If a restart of the water discharge operation is avoided, because the pivot pin 58 is lowered during the evacuation to a lower level by the pivoting movement of the sensor lever 55 around the stationary pivot pin 54. In other aspects, this embodiment works in the same way as the embodiment shown in figures 7 to 15.

The drive mechanism does not need, necessarily, have a single arm sensing lever 55. Is lever can also be double arm, in which case, the reversal of the direction of movement can be carried out of proper way, so that pressures or tractions in the media release start the water discharge operation. To the light of the exposed principles, an expert in this technique can easily arrange such system modification.

The double siphon of the discharge system can be properly formed of plastic material, and can be made in two halves, forming a separating plane between them, as shown in figures 11 to 13. As before said, sections 12 to 15 of different conduit do not need have, exactly, the flattened shape shown in 11, but the ducts preferably have a flattened or oval shape such that provide or favor laminar flow. In effect, a flow laminar favors the achievement of an efficient evacuation of all air retained in the system, at the beginning of the operation of water discharge. The use of a drive mechanism without floating bodies 34 is also within the scope of this invention. In this case, the starter piston can be lifted. directly, as indicated in figures 1 to 6. The mechanism of drive described above is especially suitable for water discharge system according to figures 7 to 18, but it can also be used, of course, for other systems of download where it is desirable to avoid restarting the download operation until a certain level has been exceeded minimum liquid in the discharge tank, during filling procedure

To allow varying the amount of liquid from download in each operation of it, the first section 12 of the duct may have air suction holes 64 at levels  different verticals, for example, a level for downloading four liters, and another level for the discharge of six liters of washing liquid When the device is installed, the installer plug the air hole (s) 64 that are not to be used.

Claims (4)

1. A drive mechanism for a system water discharge, which has an outlet device (11) disposed in a water discharge tank (10), and a input device (48) that has a floating device (40) for the control of the liquid supply inside the discharge tank (10) by means of an inlet valve (48) included in the input device (48), whose float (40) of said floating device is operatively connected to the inlet valve (48) through a link system (47) to open and close the inlet valve (48) depending on the liquid level in the discharge tank, whose device output (11) of the drive mechanism comprises means release (49) to open the outlet valve (11) of the output device, and in which the drive mechanism It has a locking device (54 to 62) to prevent initiation of a new unloading operation before the cistern of discharge (10) has been filled again with liquid up to above a predetermined minimum level; - characterized in that the blocking device (54 to 62) for the filling has a sensor lever (55) pivotally mounted on a stationary pivot pin (54), and has a cam follower (56) by means of which the sensor lever ( 55) is in operative coupling with a cam surface (57) on the float (40) to detect its movement in the vertical direction and to pivot the sensor lever (55) depending on the level of liquid in the discharge tank; because the sensor lever (55) has an oscillating release arm (59) that is pivotally mounted on the sensor lever (55) to pivot about a shaft (58) of the oscillating arm spaced from the pivot pin (54) of the sensor lever; because the release means (49) have actuation means (50) intended, when the discharge operation is initiated, to its coupling to the oscillating release arm (59), to pivot this arm and open the outlet valve (11 ), and because the oscillating arm shaft (58), the pivot pin (54) of the sensing lever, and the actuator means (50) of the release means are arranged in relation to each other to avoid each coupling between the actuator means (50) of the release means and the oscillating arm (59) when the level of liquid in the discharge tank (10) detected by the float (40) is below said predetermined level. 2. A drive mechanism according to the claim 1; - characterized in that the outlet valve (11) is connected to an opening float (23, 24) disposed in the discharge tank (10), which has a locking latch (36) pivotally mounted on the opening float (23 , 24) and that when the outlet valve (11) is closed, it is coupled to a stationary support (38), and is arranged in the movement path of the oscillating release arm (59), so that when the mechanism of drive is released, disagree with such support (38). 3. A drive mechanism according to the claims 1 or 2; - characterized in that the sensor lever (55) is a single arm lever, of which one end is pivotally mounted on the stationary pivot pin (54), and the other end has a cam follower (56) by means of which the sensor lever is attached to the float (40), and because the oscillating release arm (59) is double arm and is disposed on the sensor arm (55) between its two ends. 4. A drive mechanism according to the claims 1, 2, or 3; - characterized in that the release means (49) have return means (51) intended to press on said release means (49) in a direction such that the actuator means (50) of the release means are removed from the swing arm release (59).