Drain with adjustable overflow mechanism

Abstract

A drain comprising a drain body extending along a longitudinal axis and a shutter housed in the body of the drain and movable along the longitudinal axis with respect to the body of the drain, between a raised position, corresponding to the drain closed, and a lowered position, corresponding to the drain completely open, is described. The shutter further comprises a covering element coupled to the shutter at an upper portion of the shutter, a click-clack mechanism for the snap opening and closing of the drain, arranged in the shutter to bring the shutter from the raised position to the lowered position, or vice-versa, in response to a force applied manually by a user on the shutter along the longitudinal axis and always directed in the same direction; an overflow mechanism and manual calibration means of the overflow mechanism. The manual calibration means of the overflow mechanism are advantageously arranged on the upper portion of the shutter.

Description

[0001] Drain with adjustable overflow mechanism ***

[0002] DESCRIPTION

[0003] Field of the invention

[0004] The present invention concerns a drain for sanitary fixtures, for example washbasins or tubs, comprising an adjustable overflow mechanism.

[0005] Known art

[0006] In the industry of sanitary fixtures, it is known to make sinks, washbasins and tubs which, for aesthetic purposes, are devoid of the overflow hole, i.e. are not provided with the hole for draining the excess water, a hole which, in most sanitary fixtures, is formed in the side wall of the sanitary fixture so as to prevent the level of water contained in the sanitary fixture from exceeding a maximum limit and overflowing on the outside.

[0007] For this reason, drains to be installed in the sanitary fixtures which are not provided with the overflow hole and comprise a mechanism allowing the water to be automatically drained when the level of water in the sanitary fixture actually exceeds a maximum preset limit, were designed. Such mechanism is generally known under the name of “overflow mechanism" .

[0008] EP 2281955, in the name of the Applicant, describes a drain 1 comprising a cylindrical drain body 10 having a bottom grid 12 at the base and an annular rosette 14 at its top, which delimits the mouth 16 for the passage of water through the drain body 10. A shutter 18 is housed in the drain body 10 and is axially movable between a lowered position, in which the head 22 of the shutter 18 is below the annular rosette 14 and does not intercept the mouth 16, therefore allowing the passage of water, and a raised position, in which the head 22 of the shutter 18 intercepts the annular rosette 14 and prevents the passage of water through the mouth 16.

[0009] The drain integrates a snap mechanism for opening and closing the drain, generally defined as “click-clack," which allows the shutter to move between two extreme positions of closing and fully opening. In practice, this mechanism works similarly to the actuator usually used in ballpoint pens for controlling the extraction of the tip from the body of the pen, by pressing a button with the thumb, always in the same direction. In the case of drains, the user must act directly on the shutter with a finger, to impart an axial thrust to the shutter, always downward, so as to make the click-clack mechanism snap and cause the shutter to switch from the closed position to the open one, and vice- versa. An example of such mechanism is described in EP 1338707.

[0010] In addition to a click-clack mechanism, the shutter described in EP 2281955 further integrates an overflow mechanism.

[0011] The overflow mechanism described in EP 2281955 can be exclusively mechanical, based on a helical spring, or exclusively magnetic or, still, it can be a mechanical and magnetic hybrid, when a helical spring cooperates with the magnets to control the raising of the shutter.

[0012] Actually, according to a first embodiment, the shutter 18 rests onto the bottom grid 12 of the drain body 10 by means of a helical spring 30 which is calibrated such as to yield, by being compressed, at the exceeding of a preset pressure threshold value. In practice, when the volume of water contained in the sanitary fixture reaches and exceeds a threshold value corresponding to the maximum tolerable level of water, the pressure acting on the shutter overcomes the resistance provided by the helical spring 30, which helical spring yields, thus causing the shutter to lower and, thus, the water to be drained through the drain body 1 .

[0013] Whenever the pressure exerted by the water drops below the threshold value (because the level of water has lowered), the helical spring 30 extends and automatically brings back the shutter to the closed position; this because the pressure of water is no longer able to counter the thrust exerted by the helical spring 30.

[0014] In paragraph 30, EP 2281955 generically describes that it is possible to adjust the countering force of the helical spring 30 so as to select the maximum level of water allowed in the sanitary fixture. According to a further embodiment, the overflow mechanism is of the magnetic type, i.e. magnets are used instead of the helical spring. More in detail, the drain comprises two magnetic elements 50, 52 combined with the shutter 18 and a magnetic element 54 combined with the drain body 10; the magnetic elements are adapted for cooperating to allow / prevent the lowering of the shutter. The operation is equivalent to the one described previously: at the exceeding of a preset pressure threshold value, the magnetic elements separate and the shutter lowers to drain the water. Also in this embodiment, the operation of the overflow is automatic: the magnets cooperate to bring the shutter back to a closed position when the water pressure acting on the shutter drops below the threshold value, without the need for a user to intervene.

[0015] Finally, EP 2281955 describes a further embodiment in which the magnetic overflow mechanism further comprises, instead of the magnetic element 54, an elastic return element 30’ acting on the shutter 18. In practice, the elastic return element 30’ is arranged to facilitate the return of the shutter 18 to the closed position once the water pressure drops below the preset threshold value.

[0016] Such elastic return element 30’ rests onto the back cover 64 of the grid wall 56.

[0017] The possibility of removing the back cover 64 from the grid wall 56 and of inserting one or more spaces 70 adapted for increasing the preload of the spring between the spring 30’ and the back 64 is described in paragraph 58. This way, it is possible to vary the return force exerted by the spring and, consequently, the level of water needed in the sanitary fixture for making the overflow mechanism snap.

[0018] US 5,819,328 describes a drain which integrates an overflow mechanism. The drain comprises a shutter element 6, a bell-shaped element 19 (“shroud”) and a hub 25.

[0019] The shutter element 6 in turn comprises a head 12 and a cylindrical shaft 17 jutting out downward from the head 12. The cylindrical shaft 17 crosses the bell-shaped element 19 and the hub 25 at respective openings 22 and 9.

[0020] The head 12 of the shutter 6 is supported by a resilient element 21 , i.e. a spring, which rests onto the bell-shaped element 19 and which, as shown in figure 1 , remains housed inside a circular wall 18. The bell-shaped element 19 is supported by the hub 25 which is in turn constrained to the drain body 1 at the supporting means 7.

[0021] By selecting a resilient element 21 with a suitable spring modulus, it is possible to ensure that the shutter 6 lowers when the water in the sanitary fixture exceeds a preset limit, thus allowing the water to flow through the drain.

[0022] Although not shown, US 5,819,328 describes the possibility of integrating compressing means configured as a spacer or as a threaded collar positioned on the cylindrical shaft 17 in the drain (column 5, row 57 - column 6, row 4). This way, it is possible to selectively vary the preset level of water above which the overflow mechanism is triggered and the shutter 6 lowers.

[0023] US 10,865,552 describes, with reference to figures 3-10, a drain 10 which comprises a shutter 24 which integrates a click-clack mechanism, defined as “tip-toe" mechanism, and an overflow mechanism.

[0024] In particular, the shutter 24 comprises an upper portion 26 and a lower portion 28: the upper portion is movable reciprocally with respect to the lower portion between a raised position corresponding to the drain closed, and a lowered position corresponding to the drain open.

[0025] The shutter 24 further comprises a spring 32 arranged between the upper portion 26 and the lower portion 28, which spring pushes the upper portion 26 away from the lower portion 28 into the raised position. The spring 32 is the only resilient element present in the shutter 24.

[0026] In practice, when the water exceeds a preset level in the sanitary fixture, the spring contracts due to the pressure exerted by the water column on the shutter and the upper portion 26 lowers, thus allowing the water to be drained through the drain.

[0027] With particular reference to figure 10, an embodiment in which a small disc 52 is arranged between the spring and the lower portion is described in US 10,865,552. The small disc 52 is combined with a screw 54 which is inserted into the lower portion 28 and can be rotated from the outside to push the small disc 52 and compress the spring.

[0028] In light of what is set forth above, it is clear that drains in which the overflow mechanism can be adjusted depending on the tolerable level of water in the sanitary fixture are already known.

[0029] The solutions of the known art are not free from drawbacks.

[0030] For example, EP 2281955 describes a solution in which the adjustment of the overflow mechanism is very difficult and laborious. Actually, it requires that the operator disassembles and reassembles, also only partially, the drain during the production step: during these operations, it can happen that the operator does not reassemble the drain right, thus damaging it.

[0031] Moreover, such solution implies that the operator in charge of the assembly must have a stock of spacers of different thicknesses.

[0032] Above all, it is unlikely to think of being able to change the preload of the spring of the overflow mechanism once the drain has been sold or installed on the sanitary fixture. Also when providing packages sold with a second spacer, the final user will hardly try to replace the spacer in order to obtain a different adjustment of the overflow mechanism.

[0033] The same can be said of the solution suggested in US 5,819,328, which provides for the possibility of using a spacer to adjust the overflow mechanism.

[0034] US 10,865,552 describes a drain in which the overflow mechanism can be adjusted in an easier and quicker way than in EP 2281955, because an installer can rotate the screw placed in the lower portion of the drain without having to disassemble the shutter.

[0035] However, the calibration of the overflow mechanism seems difficult, complicated and lengthy in case the drain according to US 10,865,552 has already been installed in a sanitary fixture. In case a user should need to adjust the calibration of the overflow mechanism of a drain already mounted in a sanitary fixture according to US 10,865,552, he / she should indeed extract the drain from the sanitary fixture, adjust the calibration of the overflow mechanism and install the drain back into the sanitary fixture.

[0036] It is clear that during these operations the drain and / or the sanitary fixture could suffer damages or a user could decide not to rely on an installer and improperly mount the drain in the sanitary fixture.

[0037] Moreover, the solution described in US 10,865,552 involves the presence of a screw jutting out axially from the drain, i.e. protruding downward from the drain. Such screw increases the size of the drain in axial direction and is an area at which, during installation, it could scratch and damage components of the sanitary fixture or where, in use, dirt can accumulate (hair or fabric fibers for example).

[0038] Such adjustment screw of the overflow mechanism could be accidentally rotated when cleaning the drain or could be rotated by a vortex of water forming in the drain pipes. These circumstances can cause an accidental change in the calibration of the overflow mechanism and lead to drawbacks, such as the overflowing of water from the sanitary fixture.

[0039] US 2022 / 064922 describes a drain 1 which has a body 2 in which a shutter 7 provided with an overflow mechanism 15 is housed.

[0040] When a threshold of the water pressure acting on the head 17 of the shutter 7 is exceeded, the first magnetic element 19 and the second magnetic element 20 are automatically uncoupled, thus moving away from one another, causing the descent of the head 17 towards the lowered position and causing the opening of the mouth 6. It is described that the manufacturer of the drain 1 can take care to select the magnetic elements 19 and 20 with the calibration corresponding to the maximum level of water desired. In other words, the magnetic elements 19 and 20 are selected in the assembling step of the shutter to ensure the respective magnetic uncoupling when the desired maximum level of water is exceeded (paragraphs 31 and 78).

[0041] US 2012 / 0102640 describes a shutter assembly 21 comprising a plug 28 provided with a click-clack mechanism (“indexing type actuator"’ 37).

[0042] The plug can be removed to access the click-clack mechanism and replace the respective actuator (paragraphs 18 and 36).

[0043] Summary of the invention

[0044] Object of the present invention is therefore to provide a drain for sanitary fixtures, which is provided with an overflow mechanism and allows to overcome one or more of the drawbacks described with reference to the known art, and which is easy, compact and inexpensive to make and which allows to manually calibrate the overflow mechanism in an easy and quick way without having to take down the drain from the sanitary fixture and / or without having to disassemble the shutter and separate it from the body of the drain.

[0045] A further object of the invention is to provide a drain for sanitary fixtures which allows to avoid accidental changes to the calibration of the overflow mechanism.

[0046] In its first aspect, the present invention thus concerns a drain for sanitary fixtures, for example a washbasin or a tub, according to claim 1 .

[0047] In particular, the drain for sanitary fixtures according to claim 1 comprises a drain body extending along a longitudinal axis and a shutter housed in the body of the drain.

[0048] The body of the drain preferably comprises, in a known way, a cylindrical metal body and / or a cage-shaped, or mesh, body preferably made of a plastic material. In the case where the body of the drain comprises both a cylindrical body and a cage-shaped body, the cage-shaped body is inserted into the cylindrical body and the shutter is coupled to the cage-shaped body.

[0049] The shutter extends along the longitudinal axis in a known way.

[0050] The shutter preferably comprises a shutter body and the shutter body, or at least the shutter body, is movable with respect to the body of the drain between a raised position corresponding to the drain closed, and a lowered position corresponding to the drain open, and vice-versa.

[0051] Similarly, it is possible to state that the shutter is generally movable with respect to the body of the drain between a raised position corresponding to the drain closed, and a lowered position corresponding to the drain open, and vice- versa.

[0052] When the shutter body is in the raised position, the drain is closed and the water in the sanitary fixture is not drained into the pipes through the drain, whereas when the shutter body is in the lowered position, the drain is open and the water in the sanitary fixtures is drained into the pipes by passing through the drain from top to bottom along the longitudinal axis.

[0053] The shutter preferably comprises a lower portion: the shutter body is telescopically coupled to the lower portion. The shutter is fastened to the body of the drain at its lower portion. During the movements of the shutter body between the raised position and the lowered position, the lower portion remains stationary with respect to the drain body.

[0054] The drain according to the present invention further comprises a clickclack mechanism, i.e. a mechanism for the snap opening and closing of the drain. The click-clack mechanism is preferably integrated into the shutter, i.e. is provided inside the shutter. The click-clack mechanism is arranged for bringing the shutter body from the raised position to the lowered position, or vice-versa, in response to a force applied manually by a user on the shutter along the longitudinal axis and always directed in the same direction, i.e. downward.

[0055] In other words, in order to both open or close the drain, i.e. to bring the shutter body from the raised position to the lowered position and vice-versa, it is sufficient for a user to push the shutter, and in particular the upper portion of the shutter, downward along the longitudinal axis.

[0056] In the context of the present invention, the shutter can integrate any type of click-clack mechanism made according to the known art and / or in light of the contents of the present patent application.

[0057] The drain further comprises an overflow mechanism arranged in the shutter. When using the drain, the overflow mechanism is automatically triggered, i.e. without requiring a user to exert a force on the shutter, when the water reaches a preset level in the sanitary fixtures, i.e. at the reaching of a pressure threshold value exerted on the shutter by the water column which presses on the shutter or covering element. In practice, in a first embodiment, the overflow mechanism is triggered following the reaching of a pressure threshold value exerted on the shutter by the water column which presses on the covering element, whereas in further embodiments, the overflow mechanism is triggered in response to reaching of a pressure threshold value exerted on the shutter by the water column which presses on the shutter and not on the covering element which remains stationary instead (for example on the shutter body or a plug which closes the shutter body).

[0058] When the overflow mechanism is triggered, it brings the shutter body to a lowered position and an intermediate position between the raised position and the lowered position, thus allowing water to be drained from the sanitary fixture until the pressure exerted on the shutter by the water column returns below a threshold value.

[0059] When the pressure returns below a threshold value, the shutter body is preferably automatically brought back to the raised position by the overflow mechanism and the drain closes.

[0060] The lower portion of the shutter preferably stays stationary with respect to the body of the drain even when the overflow mechanism is triggered: indeed, the shutter body moves to the lowered or intermediate position.

[0061] The overflow mechanism is preferably integrated into the shutter, i.e. is aboard the shutter.

[0062] The drain further comprises a covering element coupled to the shutter at the upper portion of the shutter.

[0063] The covering element is preferably reversibly coupled to the upper portion of the shutter, i.e. can be coupled to and decoupled from the upper portion of the shutter by a user.

[0064] In the context of the present invention, the terms “upper” and “lower” or the expressions “downward” or “upward” are to be understood by considering the drain as generally installed in a sanitary fixture, i.e. for example with the covering element positioned above the shutter.

[0065] The shutter therefore comprises an upper portion at which the covering element is coupled to the shutter itself. This upper portion is opposite the lower portion of the shutter, when considering the longitudinal axis.

[0066] The covering element can be made of a ceramic material or other materials, such as brass, stainless steel, stone, etc. The covering element has the aesthetic task of concealing the inside of the drain and the shutter itself.

[0067] A user provides for opening and closing the drain by exerting a downward thrust at the covering element. In practice, any force applied on the covering element along the longitudinal axis can also be considered as applied on the shutter, or on the upper portion of the shutter.

[0068] The drain further comprises manual calibration means of the overflow mechanism, i.e. means designed for changing the threshold value of the pressure which triggers the overflow mechanism. In other words, the manual calibration means allow the pressure threshold value, at which the shutter automatically lowers to drain the water present in the sanitary fixture, to be varied. For example, if the drain is installed with the overflow mechanism being triggered when the water in the sanitary fixtures reaches 7 cm, a user can use the manual calibration means to trigger the overflow mechanism when the water in the sanitary fixture reaches a different height, for example 12 cm.

[0069] In practice, said manual calibration means of the overflow mechanism are designed for adjusting the pressure threshold value at which the overflow mechanism is triggered. Said manual calibration means can preferably be triggered by a user without disassembling the shutter and / or without separating the shutter from the body of the drain.

[0070] The manual calibration means of the overflow mechanism are preferably aboard the shutter, i.e. are integrated into the shutter itself.

[0071] The manual calibration means of the overflow mechanism are advantageously arranged, or positioned, on the upper portion of the shutter. In the context of the present invention, whether the manual calibration means also extend for a certain length within the upper portion of the shutter and / or downward beyond the upper portion of the shutter is influential. It is indeed sufficient for the manual calibration means of the overflow mechanism to be arranged, or positioned, at least partly on the upper portion of the shutter or for the manual calibration means to be facing outward at the upper portion of the shutter.

[0072] Since the upper portion of the shutter is the one positioned at the sanitary fixture, positioning the manual calibration means on the upper portion of the shutter allows a user to be able to operate on the manual calibration means without having to separate the drain from the sanitary fixture or without taking down the drain from the sanitary fixture to change the pressure threshold value at which the overflow mechanism is triggered.

[0073] This way, also if the drain is installed in a sanitary fixture, a user can easily and quickly change the calibration of the overflow mechanism by keeping the drain installed in the sanitary fixture and the shutter in the body of the drain, without having to disassemble the shutter itself.

[0074] Moreover, the drain according to the present invention allows the risks of damaging the drain when calibrating the overflow mechanism to be minimized or reduced to zero. On the other hand, this can occur in solutions according to the known art in which a user must separate the drain from the sanitary fixture, or separate the shutter from the body of the drain or even disassemble it, to adjust the overflow mechanism.

[0075] The manual calibration means of the drain according to the present invention are indeed not located at the lower portion of the shutter or the drain, as in some solutions according to the known art, but are aboard the upper portion of the shutter.

[0076] Another advantage of the drain according to the present invention is that it allows the risks of accidentally changing the calibration of the overflow mechanism to be reduced. Since the adjustment means are provided on the upper portion of the shutter, the possibilities that the calibration of the overflow mechanism is accidentally changed by a water vortex forming in the pipes (i.e. at the lower portion of the shutter) are indeed practically zero.

[0077] The drain is preferably configurable in two states: a first state and a second state.

[0078] The first state corresponds to the covering element coupled to the shutter and to the manual calibration means covered by the covering element, in this state, the manual calibration means are inaccessible to the user. In practice, the first state corresponds to the drain during its normal use in a sanitary fixture.

[0079] The second state corresponds to the covering element separated from the shutter and to the manual calibration means not covered by the covering element. In this state, the manual calibration means are accessible to the user who can thus act on them to adjust the overflow mechanism.

[0080] Indeed, when the drain is in the first state, a user cannot change the pressure threshold value at which the overflow mechanism is triggered, because they are precisely concealed by the covering element; on the other hand, when the drain is in the second state, a user can manually adjust the pressure threshold value by acting on the manual calibration means of the overflow mechanism positioned on the upper portion of the shutter, because they are precisely no longer concealed by the covering element.

[0081] The fact that, during normal use of the drain, the manual calibration means are concealed from the user ensures that normal users or users who are practically not aware of the operation of the drain (such as children) cannot easily change the pressure threshold value at which the overflow mechanism is triggered.

[0082] As a matter of fact, in order to act on the manual calibration means, a user must knowingly separate the covering element from the shutter: this operation is not part of the normal use of a drain (which is usually solely opened or closed by a user) and, therefore, the likelihood that a normal user of the sanitary fixture acts on the manual calibration means when the drain is in the first state is minimal, if not zero.

[0083] This characteristic minimizes even more the likelihood that the calibration of the overflow mechanism can be accidentally changed, for example during cleaning operations of the sanitary fixture.

[0084] The shutter preferably comprises a lower portion extending on the longitudinal axis and opposite the upper portion of the shutter. The shutter is combined with the body of the drain at the lower portion. For example, the shutter can be fit on a pin of the body of the drain or can be screwed into the body of the drain at its own lower portion.

[0085] The upper portion of the shutter preferably has an upper surface which is opposite the lower surface: the manual calibration means are provided on the upper portion at said upper surface of the shutter.

[0086] Indeed, it is known that when the covering element is combined with the shutter, it covers the upper surface of the shutter. Thus, when the covering element is combined with the shutter, the manual calibration means are concealed and inaccessible to the users of the sanitary fixture.

[0087] Moreover, once the covering element is removed from the drain, the fact that the manual calibration means are positioned on the upper surface of the shutter ensures that a user can change the calibration of the overflow mechanism while keeping the shutter installed in the sanitary fixture, i.e. without disassembling the drain and / or the shutter from their seat.

[0088] The shutter is preferably provided with coupling means at which the covering element is coupled to the shutter itself. For example, the shutter can be provided with a threaded portion onto which the covering element is screwed.

[0089] Considering the longitudinal axis, the coupling means are preferably arranged, or extend, between the upper surface and the lower surface of the shutter. In other words, the upper surface is axially positioned above the means for coupling the shutter to the covering element. This ensures that, when the drain is in the first state, the covering element conceals the manual calibration means.

[0090] A first embodiment of the drain will now be described.

[0091] In the first embodiment, the manual calibration means are manually movable by a user with respect to the lower portion between a first position, which is distal from the lower portion, and a second position, which is proximal to the lower portion, and vice-versa. When a user manually displaces the manual calibration means between the first position and the second position, he / she adjusts the calibration of the overflow mechanism, i.e. changes the pressure threshold value at which the overflow mechanism is triggered.

[0092] In particular, the first position corresponds to a first pressure threshold value and the second position corresponds to a second pressure threshold value different from the first threshold value.

[0093] The second threshold value is preferably greater than the first threshold value. For example, the second pressure threshold value corresponds to a pressure value generated by a 13-cm high water column pressing on the shutter, whereas the first pressure threshold value corresponds to a pressure value generated by a 6-cm high water column pressing on the shutter.

[0094] This first embodiment has the advantage of allowing the calibration of the overflow to be changed without having to rely on external components, such as spacers.

[0095] In this first embodiment, during normal use of the drain and during calibration of the overflow mechanism, the manual calibration means are not designed for being separated from the shutter, i.e. a user does not have to separate them from the shutter but stay combined therewith.

[0096] The manual calibration means are preferably manually movable by a user to a plurality of intermediate positions between the first position and the second position, so as to be able to adjust the calibration of the overflow mechanism according to an intermediate pressure threshold value between the first threshold value and the second threshold value.

[0097] In addition to being arranged on the upper portion, the manual calibration means are also preferably inserted into the upper portion of the shutter (and are facing outward at the upper portion).

[0098] In the first embodiment, the manual calibration means are rotatable by a user in the upper portion of the shutter, so as to adjust the calibration of the overflow mechanism and change the pressure threshold value at which the overflow mechanism is triggered. In particular, the calibration means are rotatable on the longitudinal axis in a first direction and in a second direction opposite the first, and vice-versa.

[0099] When a user rotates the manual calibration means in the first direction, the manual calibration means are preferably displaced from the first position to the second position, or to an intermediate position between the first position and the second position.

[0100] Instead, when a user rotates the manual calibration means in the second direction, the manual calibration means are displaced from the second position, or from the intermediate position, to the first position.

[0101] It is thus a matter of roto-translation, i.e. by rotating the manual calibration means in the first direction, the manual calibration means translate on the longitudinal axis towards the lower portion, whereas by rotating the manual calibration means in the second direction, the manual calibration means translate away from the lower portion on the longitudinal axis.

[0102] The calibration change of the overflow mechanism is thus reversible, i.e. once the pressure threshold value has been changed by rotating the calibration means to the upper portion of the shutter, it is possible to return to the initial pressure threshold value by rotating the calibration means in the opposite direction, thus bringing them back to the initial position.

[0103] A hole, extending along the longitudinal axis, is preferably formed in the upper surface of the upper portion: the manual calibration means are inserted into this hole and can roto-translate in the hole towards or away from the lower portion, in response to rotation manually imparted by a user in the first direction or the second direction. In practice, the manual calibration means are screwable or unscrewable into / from the upper portion of the shutter between the first position and the second position, in response to a rotation imparted by a user in the first direction and in the second direction, respectively.

[0104] The hole formed in the upper surface preferably is a through hole which is preferably threaded.

[0105] The manual calibration means preferably have an upper surface and are provided with a blind hole formed in this upper surface.

[0106] In practice, a user can insert a tool into this blind hole to manually control the manual calibration means, i.e. to impart a rotation to them and move them between the first position and the second position.

[0107] Generally, the adjustment of the overflow mechanism through the manual calibration means can be considered “manuaF even if operated by means of a tool because it is anyhow controlled by a user, i.e. it is not automatic like the triggering of the overflow mechanism.

[0108] When the manual calibration means are in the first position, the upper surface of the manual calibration means is preferably flush, or almost flush, with respect to the upper portion of the shutter, i.e. with respect to the upper surface of the upper portion of the shutter; when the manual calibration means translate towards the lower portion, the upper surface of the manual calibration means is no longer flush with respect to the upper portion of the shutter, but is inserted into the upper portion, i.e. it is in a position more proximal to the lower portion than when the manual calibration means are in the first position. This can occur when the manual calibration means are in the second position or are in an intermediate position between the first position and the second position.

[0109] When the calibration means are in the second position or are in an intermediate position between the first position and the second position, they can also be considered to be on the upper portion because they are anyhow accessible to a user, as the upper portion.

[0110] As far as the operation of the click-clack mechanism and the overflow mechanism is concerned, the upper portion of the shutter is preferably movable along the longitudinal axis X with respect to the lower portion, which stays stationary. In particular, the upper portion is movable from a raised position with respect to the lower portion of the shutter to a lowered position with respect to the lower portion of the shutter, and vice-versa, in response to the triggering of the click-clack mechanism. In practice, these movements correspond to the user-controlled opening and closing of the drain.

[0111] Or the upper portion is movable from a raised position with respect to the lower portion of the shutter to an intermediate position between said raised position and said lowered position with respect to the lower portion of the shutter, and vice-versa, in response to the triggering of the overflow mechanism. These movements correspond to the automatic triggering of the overflow mechanism.

[0112] The manual calibration means are preferably integral with the upper portion of the shutter and move therewith, with respect to the lower portion of the shutter, during displacements of the upper portion of the shutter along the longitudinal axis due to the triggering of the click-clack mechanism or the triggering of the overflow mechanism. Instead, the manual calibration means are movable by a user with respect to the upper portion of the shutter and with respect to the lower portion of the shutter between the first position and the second position, and vice-versa, in response to a force imparted by a user for adjusting the calibration of the overflow mechanism.

[0113] In other words, when a user changes the calibration of the overflow mechanism, the manual calibration means are displaced, roto-translate for example, with respect to the upper portion, independently of the fact that the upper portion can also accidentally move with respect to the lower portion during the calibration of the overflow mechanism.

[0114] In the first embodiment, the manual calibration means are configured as a threaded insert inserted into a threaded hole formed in the upper surface of the upper portion of the shutter and extending along the longitudinal axis. The shutter preferably comprises a rod-shaped element and a plug.

[0115] The rod-shaped element in turn comprises a stem at which the shutter is coupled to the body of the drain; the plug closes the rod-shaped element, or the body of the rod-shaped element, on top, i.e. it is positioned on the side opposite the stem. The plug is movable along the longitudinal axis with respect to the rod-shaped element:

[0116] - between a raised position with respect to the rod-shaped element, corresponding to the drain closed, and a lowered position with respect to the rod-shaped element, corresponding to the drain open, and vice-versa, in response to the triggering of the click-clack mechanism, or

[0117] - between the raised position with respect to the rod-shaped element and the lowered position or an intermediate position between the raised and lowered positions, and vice-versa, in response to the triggering of the overflow mechanism.

[0118] In practice, during these movements, the plug of the shutter is integral with the shutter body.

[0119] In practice, what is described above with reference to the reciprocal movements between the upper portion of the shutter and the lower portion of the shutter can be extended to the relative movements between the plug and the rod-shaped element: the plug belongs to the upper portion of the shutter, whereas the rod-shaped element, and in particular the stem, belongs to the lower portion of the shutter.

[0120] In the first embodiment, the manual calibration means are provided on the plug and are manually movable by a user towards and away from the rodshaped element with respect to the plug, to adjust the calibration of the overflow mechanism.

[0121] The shutter preferably comprises a resilient element, or an elastic element (for example a spring), of the overflow mechanism, identified as second resilient element, which resilient element is functionally interposed between the manual calibration means and the rod-shaped element. In other words, regardless of a particular shape of the rod-shaped element, the second resilient element is arranged between the manual calibration means and the rod-shaped element to allow the shutter body to move to the lowered position or an intermediate position since the overflow mechanism is triggered.

[0122] In the first embodiment, the shutter can be manually configured by a user in at least one first configuration and one second configuration by acting on the manual calibration means. This precisely occurs by respectively displacing the manual calibration means between the first position and the second position. When the manual calibration means are displaced from the first position to the second position, the second resilient element is more compressed than when the manual calibration means are in the first position. The adjustment of the overflow mechanism precisely exploits this principle; in effect, the pressure threshold value at which the overflow mechanism is triggered is greater when the manual calibration means are in the second position.

[0123] Obviously, the shutter can be configured in a plurality of intermediate configurations between the first configuration and the second configuration, depending on when the manual calibration means are screwed into the upper portion.

[0124] As an alternative, it is possible to make a drain in which the second resilient element is replaced with a couple of magnetic elements with the same polarity, i.e. which repel one another: a magnetic element positioned on the manual calibration means and the other magnetic element positioned aboard the rod-shaped element. The latter magnetic element can be the second magnetic element described below or a further magnetic element provided on the rod-shaped element.

[0125] The shutter can comprise a further couple of magnetic elements identified as first magnetic element and second magnetic element, with opposite polarity, i.e. which attract one another: the first magnetic element inserted into the shutter body and the second magnetic element positioned aboard the rod- shaped element. The second magnetic element is preferably arranged between the first magnetic element and the plug.

[0126] Finally, the click-clack mechanism can be made according to one of the known solutions of the field.

[0127] Further embodiments, identified as second embodiment, third embodiment and fourth embodiment, are described hereunder.

[0128] The manual calibration means of the overflow mechanism are preferably reversibly coupled to the shutter at the upper portion, i.e. they can be separated from the shutter and replaced with different manual calibration means to change the threshold value of the pressure exerted on the shutter at which the overflow mechanism is automatically triggered.

[0129] The manual calibration means are preferably configured as an insert and have an upper surface in which a blind hole is formed and designed for being engaged by a tool controlled manually by a user to separate the manual calibration means from the upper portion and replace them with different manual calibration means. This way it is possible to change the calibration of the overflow mechanism.

[0130] The upper portion preferably comprises a plug and a supporting element which supports the covering element. The plug can be made in one piece with the shutter body or can be made as an element distinct therefrom and constrained to the shutter body so as to be integral therewith.

[0131] The supporting element is preferably arranged axially between the covering element and the lower portion and the manual calibration means are coupled to the plug or the shutter body at the supporting element, so that they can be positioned on the upper portion of the shutter and accessible to a user after the covering element has been separated.

[0132] The supporting element preferably has a through hole along the longitudinal axis and said manual calibration means can be inserted into and removed from the plug or the shutter body through that through hole.

[0133] Preferably, in a drain according to the second, third and fourth embodiment:

[0134] - the click-clack mechanism is arranged for being triggered in response to a force exerted by a user at the covering element and always directed towards said lower portion;

[0135] - the overflow mechanism is arranged for being automatically triggered in response to reaching a threshold value of the pressure exerted on the shutter by the water column, which, in use, presses on the shutter plug or the shutter body.

[0136] When the overflow mechanism is triggered, the upper portion of the drain stays stationary, or almost stationary, with respect to the rod-shaped element, i.e. it does not significantly lower. This characteristic differentiates these embodiments from the first embodiment; indeed, in the first embodiment, the upper portion lowers as a result of the triggering of the overflow mechanism.

[0137] This aspect ensures that the weight of the covering element does not affect the overflow mechanism and instead it only depends on the pressure exerted by the water column present in the sanitary fixture.

[0138] The click-clack mechanism of the second, third and fourth embodiments can be made in the following way: at the upper portion, the shutter preferably comprises a flange and a bearing inserted into the flange, the flange rests on the body of the drain and the bearing is rotatable on the longitudinal axis with respect to the flange in response to a pressure exerted by a user for triggering the click-clack mechanism; the shutter comprises a resilient (or elastic) element of the click-clack mechanism, identified as first resilient element, designed for being compressed when the upper portion lowers with respect to the shutter body and for extending, thus bringing back the upper portion to the raised position. For example, the first resilient element is a spring.

[0139] The bearing preferably comprises at least one protrusion, or a tooth, which engages a corresponding profile provided in the flange, wherein the profile has at least one upper seat and at least one lower seat, and wherein:

[0140] - when the protrusion engages the at least one upper seat, the shutter body is in the raised position and the drain is closed, and

[0141] - when the protrusion engages the at least one lower seat, the shutter body is in the lowered position and the drain is open.

[0142] In the second embodiment, the lower portion comprises a rod-shaped element and the upper portion comprises a plug which closes the rod-shaped element and / or the shutter body; the rod-shaped element in turn comprises a stem at which the shutter is coupled to the body of the drain. The plug is movable integrally with the shutter body along the longitudinal axis with respect to the rod-shaped element between the raised position and the lowered position or between the raised position and an intermediate position between the raised position and the lowered position, and vice-versa, in response to the triggering of the overflow mechanism. The shutter comprises a resilient element of the overflow mechanism, identified as second resilient element, which is housed in the rod-shaped element and functionally interposed between the manual calibration means and the rod-shaped element.

[0143] The manual calibration means preferably extend along the longitudinal axis for a first length to which a first threshold value corresponds; these manual calibration means are adapted for being replaced with other manual calibration means, identified as “different manual calibration means” because they are different from those already inserted into the drain. Such different manual calibration means differ from said manual calibration means in that they extend for a length greater or less than the first length.

[0144] In practice, the different manual calibration means are longer or shorter than said manual calibration means.

[0145] Thus, after these different manual calibration means have been inserted into the drain to replace the manual calibration means described above, it is possible to trigger the overflow mechanism at a pressure threshold value greater or less than the first threshold value.

[0146] For example, the manual calibration means can be configured as an insert extending along the longitudinal axis X and which can be between 5 mm and 15 mm in length. For example, this insert can be of a length of 11 mm, 14.5 mm or 18 mm. For example, using a 14.5 mm insert results in the triggering of the overflow mechanism, when the water in the sanitary fixture reaches a height of 8 cm.

[0147] By replacing this insert with different inserts, for example of 11 mm or 18 mm, it is possible to cause the triggering of the overflow mechanism when the water in the sanitary fixture reaches a height of 6 cm or 10 cm, respectively.

[0148] In the third embodiment, the drain comprises a ferromagnetic element integral with the body of the drain and extending along the longitudinal axis, the shutter comprises a magnetic element integral with the shutter body and susceptible to displacements with respect to the ferromagnetic element.

[0149] The magnetic element is preferably coaxial to the ferromagnetic element. The shutter body is movable with respect to the ferromagnetic element between the raised position and the lowered position or an intermediate position between said raised position and said lowered position, and vice-versa, in response to the triggering of the overflow mechanism.

[0150] When the drain is closed, the magnetic element faces the ferromagnetic element, whereas when the shutter body lowers in response the pressure threshold value being reached, the magnetic element is lowered relative to the ferromagnetic element and the latter protrudes with respect to the magnetic element. In this circumstance, an attractive force develops between the magnetic element and the ferromagnetic element, which tends to bring back the magnetic element to the position aligned with the ferromagnetic element and the shutter body to the raised position.

[0151] In the fourth embodiment, the shutter body is supported on the body of the drain by means of a resilient element, identified as third resilient element and preferably configured as a harmonic steel lever. The third resilient element is configurable in a first extended configuration and a second contracted configuration: the shutter body is movable with respect to the third resilient element between the raised position and the lowered position, and vice-versa, in response to the triggering of the overflow mechanism. When the shutter is in the raised position, the third resilient element is in an extended configuration and does not exert a significant upward force on the shutter body, whereas when the shutter body is in the lowered position, the third resilient element is in a contracted position and exerts an upward thrust which tends to bring back the shutter body to the raised position.

[0152] In the third and fourth embodiments, the shutter comprises a resilient element of the overflow mechanism, identified as second resilient element, which resilient element is housed in the shutter body and interposed between the shutter body and the manual calibration means. In these embodiments, when replacing the manual calibration means with different calibration means, if the different manual calibration means are longer than the previous ones, the pressure threshold value is lower than the previous one, whereas if they are shorter, the pressure threshold value is higher than the previous one.

[0153] In the third and fourth embodiments, the overflow mechanism exerts a force on the shutter body that is constant throughout its displacement, as will become clearer below in the particular description of the embodiments.

[0154] It is clear that a technician of the field will be able to combine one or more characteristics of the different embodiments to achieve contingent improvements.

[0155] The drain according to this second embodiment can have one or more of the characteristics described below with reference to figures 19-46.

[0156] In its further aspect, the present invention concerns a method of calibrating the overflow mechanism of a drain according to claim 25. This method provides for the use of a drain as described above and has one or more of the advantages described with reference to the drain according to the present invention.

[0157] Brief list of the figures

[0158] Further characteristics and advantages of the invention will better be highlighted by the review of the following detailed description of preferred, although not exclusive, embodiments depicted by way of example and without limitations, with the aid of the accompanying drawings, in which:

[0159] - figure 1 is a front elevation view of a first embodiment of the drain according to the present invention, devoid of the cylindrical body 2a shown in figure 14. In this figure, the drain has the shutter 6 in a raised position, corresponding to the drain closed;

[0160] - figure 2 is an axial sectional view of the drain shown in figure 1 , considered with respect to the sectional plane AK-AK of figure 1 ;

[0161] - figure 3 is a front elevation view of the drain shown in figure 1 , with the shutter 6 in a lowered position, corresponding to the drain open;

[0162] - figure 4 is an axial sectional view of the drain shown in figure 3, considered with respect to the sectional plane AL-AL of figure 3;

[0163] - figure 5 is a front elevation view of the drain shown in figure 1 , with the shutter 6 in an intermediate position between the raised position and the lowered position, corresponding to the overflow mechanism triggered;

[0164] - figure 6 is an axial sectional view of the drain shown in figure 5, considered with respect to the sectional plane AN-AN of figure 5;

[0165] - figure 7 is an exploded view of the shutter 6 of the drain shown in figure 1 ;

[0166] - figure 8 is a sectional view of the components of the shutter 6 shown in figure 7; the view is considered with respect to the plane AM-AM of figure 7;

[0167] - figure 9 is a front elevation view of the shutter 6 of the drain shown in figure 1 , in a first configuration of use;

[0168] - figure 10 is an axial sectional view of the shutter 6 shown in figure 9, considered with respect to the plane AN-AN of figure 9;

[0169] - figure 11 is a front elevation view of the shutter 6 of the drain shown in figure 1 , in a second configuration of use;

[0170] - figure 12 is an axial sectional view of the shutter 6 shown in figure 11 , considered with respect to the plane AP-AP of figure 11 ;

[0171] - figure 13 is an isometric view of a first embodiment of a component of the shutter of the drain shown in figure 1 , thus specifically the manual calibration means of the overflow mechanism;

[0172] - figure 14 is a front elevation view of a first preferred embodiment of the drain according to the present invention;

[0173] - figures 15, 16, 17, 18 are axial sectional views of the drain shown in figure 1 , wherein the ring 22 is shown in transparency. The sequence for triggering the click-clack mechanism is shown in these figures. In particular, there is shown: a drain in the closed configuration with the shutter in a raised position (fig. 15), a drain with the shutter in a first snap position (fig. 16), a drain in an open configuration and with the shutter in a lowered position (fig. 17), a drain with the shutter in a second snap position (fig. 18).

[0174] - figure 19 is a front elevation view of a second embodiment of the drain according to the present invention. In this figure, the drain has the shutter 6’ in a raised position, corresponding to the drain closed;

[0175] - figure 20 is an axial sectional view of the drain shown in figure 19, considered with respect to the sectional plane CD-CD of figure 19;

[0176] - figure 21 is a front elevation view of the drain shown in figure 19, with the shutter 6’ in a lowered position, corresponding to the drain open in response to the triggering of the click-clack mechanism;

[0177] - figure 22 is an axial sectional view of the drain shown in figure 21 , considered with respect to the sectional plane BJ-BJ of figure 21 ;

[0178] - figure 23 is a front elevation view of the drain shown in figure 19, with the shutter 6’ in a lowered position, corresponding to the overflow mechanism triggered;

[0179] - figure 24 is an axial sectional view of the drain shown in figure 23, considered with respect to the sectional plane BC-BC of figure 23;

[0180] - figure 25 is an exploded view of the shutter 6’ of the drain shown in figure 19.

[0181] With reference to figures 26-46, the components of the shutter 6’ of the drain shown in figure 19 are shown, and in particular: figures 26, 27, 28 show an elevation view, a sectional view with respect to the sectional plane BV-BV shown in figure 26, a bottom perspective view, respectively, of the rod-shaped element; figures 29, 30, 31 show an elevation view, a sectional view with respect to the sectional plane BV-BV shown in figure 29, a bottom perspective view, respectively, of the shutter body; figures 32 and 33 respectively show an elevation and sectional views of the spring-holder element with respect to the sectional plane BV-BV shown in figure 32; figures 34 and 35 respectively show an elevation and sectional views of the plug of the shutter, with respect to the sectional plane BV-BV shown in figure 34; figures 36, 37 and 38 show an elevation view, a sectional view with respect to the sectional plane BV-BV shown in figure 36, and a perspective view, respectively, of the shutter flange; figures 39 and 40 respectively show an elevation and sectional views of the bearing with respect to the sectional plane BV-BV shown in figure 39; figures 41 and 42 respectively show an elevation and sectional views of the support of the covering with respect to the sectional plane BT-BT shown in figure 41 ; figures 43, 44, 45 and 46 show an elevation view, a sectional view with respect to the sectional plane BV-BV shown in figure 43, a top perspective view and a bottom perspective view, respectively, of an insert; figures 47, 48 and 49 show an elevation and sectional view on a plane containing the longitudinal axis X” of a closed drain according to a third embodiment, respectively, with the click-clack mechanism triggered and the overflow mechanism triggered; figures 50, 51 and 52 show an elevation and sectional view on a plane containing the longitudinal axis X’” of a closed drain according to a fourth embodiment, respectively, with the click-clack mechanism triggered and the overflow mechanism triggered.

[0182] Detailed description of the invention

[0183] With reference to figures 1 -18, a first embodiment of the drain according to the present invention is described hereunder. The drain is shown as a whole in figure 14 and denoted by the reference number 1. Figure 14 shows a front elevation view of the drain 1 .

[0184] In figure 14, it is possible to observe that the drain 1 comprises a body, generically denoted by the reference number 2, extending along a longitudinal axis X. In the embodiment described herein, the body 2 comprises a cylindrical body 2a and a cage-shaped body 2b (visible, for example, in figure 1 ); the cageshaped body 2b is inserted into the cylindrical body 2a and is therefore not visible in figure 14.

[0185] The cylindrical body 2a is preferably made of metal, whereas the cageshaped body 2b is preferably made of a plastic material.

[0186] The cylindrical body 2a is provided with a threaded portion 3 which allows the drain 1 to be screwed into a sanitary fixture, a washbasin or tub for example. On top, the cylindrical body 2a is provided with a rosette 4 which delimits a mouth for the passage of the water through the drain 1 .

[0187] When the drain 1 is properly installed in the sanitary fixture, the water to be drained from the sanitary fixture flows through the drain from top to bottom (seeing figure 14).

[0188] The drain 1 further comprises a covering element, denoted by the reference number 5 in figure 14. As known, the covering element 5 has an aesthetic function, i.e. to cover and not make the inside of the drain 1 visible to users.

[0189] The covering element 5 is coupled to a shutter 6 of the drain 1 .

[0190] The covering element 5 can, for example, be screwed into an upper portion 7 of the shutter 6. It is precisely at the covering element 5 that a user can exert a thrust on the shutter 6 to bring it to a lowered position or a raised position and thus to open or close the drain 1 , as will be better described with reference to figures 1-4. As will be more clearly described below, the shutter 6 comprises an upper portion 7 and a lower portion 9: the shutter 6 can be brought to the lowered position, in the sense that the upper portion 7, and in particular the shutter body, is brought to a lowered position (and possibly subsequently to a raised position) in response to a thrust exerted by a user.

[0191] A drain 1 devoid of the cylindrical body 2a is shown in figures 1-4; indeed, it is possible to observe the presence of the cage-shaped body 2b only. In practice, when assembling the drain 1 , the cage-shaped body 2b is inserted with the shutter 6 into the cylindrical body 2a through the mouth and the drain 1 thus assembled is subsequently installed in the sanitary fixture.

[0192] As mentioned above, the drain 1 actually comprises a shutter 6 extending on the longitudinal axis X and designed for opening and closing the passage of water through the drain 1. The shutter 6 is housed in the body 2 of the drain 1 ; in the embodiment described herein, the shutter 6 is housed in the cylindrical body 2a and the cage-shaped body 2b.

[0193] The shutter 6 housed in the cage-shaped body 2b is shown in figure 1 ; as shown in the section depicted in figure 2, in the preferred embodiment, the shutter 6 is hinged on a pin 8 of the cage-shaped body 2b at its lower portion 9. The pin 8 extends along the longitudinal axis X.

[0194] As an alternative, the drain 1 can be provided with a cage-shaped body 2b and the cylindrical body 2a can comprise means for fastening the shutter 6, which extend radially to the longitudinal axis (lower cross mark) and configured as a bridge-shaped element at which the shutter 6 can be fastened (for example screwed) at its lower portion 9.

[0195] The shutter 6 is movable with respect to the body 2 on the longitudinal axis X, between a raised position corresponding to the drain 1 closed, and a lowered position corresponding to the drain 1 open.

[0196] In particular, the shutter 6 is shown in a raised position in figures 1 and 2, whereas the shutter is shown in a lowered position in figures 3 and 4. In the sectional views shown in figures 2 and 4, it is possible to observe that the body 2 delimits a mouth 10 for water at which water can flow from the sanitary fixture to the drain pipes through the drain 1 .

[0197] As shown in figure 2, when the shutter 6 is in a raised position, the mouth 10 is closed, i.e. it is intercepted by the shutter 6; in this circumstance, the water contained in the sanitary fixture cannot be drained through the drain 1 .

[0198] On the other hand, figures 3 and 4 show that when the shutter 6 is in a lowered position, the mouth 10 is open (i.e. is not intercepted by the shutter 6) and the water contained in the sanitary fixture can be drained through the drain 1.

[0199] For such purpose, the shutter 6 can be equipped with a gasket 11 , for example of the O-ring type, especially intended for closing the mouth 10.

[0200] The drain 1 comprises a so-named click-clack mechanism and, in particular, the click-clack mechanism is integrated into the shutter 6.

[0201] In practice, the shutter 6 comprises a mechanism for the snap opening and closing of the drain 1 . As described with respect to the known art, a clickclack mechanism has the task of allowing the user to voluntarily and selectively control the displacement of the shutter 6 from the raised position to the lowered position, and vice-versa. The user just has to exert a first downward thrust on the shutter 6 to make the click-clack mechanism snap and to bring the shutter 6 from the raised position to the lowered position. The shutter 6 stays in a lowered position until the user intervenes a second time by applying a second downward thrust on the shutter 6, to make the click-clack mechanism snap again. In this circumstance, the shutter 6 is displaced from the lowered position to the raised position, where the shutter 6 stays until the user intervenes once more. In practice, the user always exerts the thrust in the same direction, i.e. along the longitudinal axis X, and in the same way, thus causing movements of the shutter 6 in opposite directions.

[0202] As mentioned above, the shutter 6 is combined with a covering element 5. The covering element 5 is coupled to the upper portion of the shutter 6. For example, the covering element 5 can be screwed into a thread 12 of the shutter 6 visible in figures 2 and 4. As an alternative, the covering element 5 could be interlocked or glued. It is precisely at the covering element 5 that a user can exert a thrust on the shutter 6, always directed downward, to bring it to the lowered position or the raised position and thus to open or close the drain 1 .

[0203] Click-clack mechanisms, i.e. mechanisms for the snap opening and closing of the drains, are known in the art: examples are described in the documents of the known art set forth above. As known, click-clack mechanisms are mechanisms which are triggered in response to a force exerted by a user, i.e. they are not automatic mechanisms.

[0204] For the purposes of the present invention, it is not specified which specific click-clack mechanism is incorporated in the drain 1 , since different click-clack mechanisms are known.

[0205] By way of example, the click-clack mechanism integrated into the shutter 6 of the drain 1 will be described hereunder.

[0206] In addition to a click-clack mechanism, the shutter 6 further integrates an overflow mechanism, i.e. a mechanism which allows the shutter 6 in a raised position to automatically lower when the pressure of the water column acting on the covering element 5 reaches a preset threshold value. This way, the drain 1 can discharge sanitary fixture excess water. When the value of the pressure drops below the preset threshold value, the shutter automatically returns to the raised position, thus closing the drain 1.

[0207] Unlike the triggering of the click-clack mechanism which requires the intervention of a user, the operation of the overflow mechanism is thus automatic, i.e. does not require a user to trigger it.

[0208] The operational principle of the overflow mechanism of the drain 1 is thus similar to the one described with reference to the known art.

[0209] For example, the drain 1 with the overflow mechanism triggered, i.e. wherein the shutter 6 is in an intermediate position between the raised position and the lowered position, is depicted in figures 5 and 6. As known, the triggering of the overflow mechanism does not lead to the triggering of the click-clack mechanism because the pressure of water in a sanitary fixture is never sufficient to push the shutter 6 up to the snap position.

[0210] The operation of the drain 1 can be illustrated more precisely after having described the components shown in figures 7 and 8.

[0211] In particular, figure 7 shows an exploded view of the shutter 6 and figure 8 shows a sectional view of the components shown in figure 7, which is considered with respect to the plane AM-AM of figure 7.

[0212] Once assembled in a drain 1 , the shutter 6 shares the longitudinal axis X, shown in figure 7 for this reason, therewith.

[0213] The shutter 6 comprises a shutter body 13 provided with an upper end 13a and a lower end 13b.

[0214] The shutter body 13 is hollow, i.e. comprises a cavity 14 extending along the longitudinal axis X from the upper end 13a to the lower end 13b.

[0215] At the lower end 13b, the shutter body 13 comprises a ring 15 which has an upper surface 16, also identified as first abutment surface 16. The ring 15 has a diameter smaller than the one of the rest of the shutter body 13 and the ring 15 has, at the inner surface, one or more ribs 55 jutting out towards the longitudinal axis X and extending parallel to the longitudinal axis X itself. In the embodiment shown herein, the ribs 55 are two and face one another.

[0216] At its inner surface, the shutter body 13 has a second abutment surface 17 extending circularly with respect to the longitudinal axis X between the upper end 13a and the lower end 13b, about halfway up the shutter body 13.

[0217] Moreover, at the inner surface, the shutter body 13 further has a third abutment surface 18 extending circularly with respect to the longitudinal axis between the second abutment surface 17 and the upper end 13a.

[0218] At the upper end 13a, the shutter body 13 has blind holes, i.e. cutouts 19. Four cutouts 19 are preferably provided.

[0219] Finally, at the lower end 13b, the shutter body 13 has a groove 20 formed in the ring 15. Such groove 20 extends in a circular way with respect to the longitudinal axis X and can be provided on the ring 15 facing the outside of the shutter body 13, or it can be facing the cavity 14 and be provided in the abutment surface 16 of the ring 15.

[0220] A first ring-shaped magnet 21 , constituting one of the components of the overflow mechanism, is housed in the groove 20.

[0221] The ring 22, visible in figures 7 and 8, is another component of the shutter 6. The ring 22 is circular-shaped and has one or more protrusions 23 jutting out from the inner surface of the ring 22. In the embodiment described herein, the ring 22 has two protrusions 23 arranged one in front of the other, as shown in figure 8.

[0222] In figures 8 and 9, it is possible to see that the shutter 6 further comprises a rod-shaped element 24. The rod-shaped element 24 comprises a cup-shaped body 25 and a rod 26, or stem 26, jutting out downward from the body 25 along the longitudinal axis X. The stem 26 preferably extends inside the body 25 to form a pin 27 visible in figure 8. The stem 26 is preferably hollow and has an opening 28 at its lower end. The shutter 6 is fit on the pin 8 of the cage-shaped body 2b precisely at the opening 28 of the stem 26.

[0223] Grooves 29 running along the stem 26 along its whole length, parallel to the longitudinal axis X, are formed on the outer surface of the stem 26. In the preferred embodiment, the grooves 29 are four.

[0224] On the outer surface of the body 25, the rod-shaped element 24 has one or more circuits 30 in which, in use, the protrusions 23 of the ring 22 run. The circuits 30 are preferably two and are formed on opposite sides in the body 25, as shown in figure 8. The circuits 30 are substantially grooves formed on the outer surface of the body 25 and which extend between an upper end 25a of the body 25 and a lower end 25b of the body 25.

[0225] The two circuits 30 are identical to one another and reference will thus be made hereunder to circuit 30 only, visible in figure 7, for the description.

[0226] The circuit 30 has a central relief 31 ; the circuit 30 is thus delimited by an outer wall defined at the outer surface of the body 25, and an inner wall defined at the central relief 31 .

[0227] The circuit 30 has a seat 32 at the upper end 25a. On the opposite part, the circuit 30 comprises a first concavity 33 and a second concavity 34 separated by a cusp 35.

[0228] Figure 7 shows that the circuit 30 opens to the outside, at the second concavity 34.

[0229] A recess 36, which is positioned between the cusp 35 and the second concavity 34, is formed on the inner wall.

[0230] One or more magnets, kept in their seat by a respective bushing, are housed inside the body 25.

[0231] A magnet, identified as second magnet 37, and a bushing 38 are preferably housed in the body 25. The magnets 37 and the bushing 38 are fit on the pin 27 of the rod-shaped element 24.

[0232] The second magnet 37 is also part of the overflow mechanism.

[0233] The shutter 6 further comprises two resilient elements: a first resilient element 39 (or elastic element), such as a spring for example, and a second resilient element 40, such as a spring for example. The two resilient elements have different spring moduli: in particular, the first resilient element 39 has a greater spring modulus than the second resilient element 40. As will be set forth hereunder, the first resilient element 39 is involved in the triggering of the clickclack mechanism, whereas the second resilient element 40 in the triggering of the overflow mechanism.

[0234] The second resilient element 40 preferably has a length greater than that of the first resilient element 39.

[0235] Each resilient element 39, 40 has an upper end 39a, 40a and a lower end 39b, 40b.

[0236] The resilient elements 39, 40 are housed, at their respective lower ends 39b and 40b, in the body 25 of the rod-shaped element 24 and rest on the bushing 38. Moreover, the resilient elements 39, 40 are fit on the pin 27 in a concentric way: the first resilient element 39 is positioned outside the second resilient element 40. The resilient elements 39, 40 are housed, at their respective upper ends 39a, 40a, in a plug 41 of the shutter 6.

[0237] In practice, the plug 41 is named in this way because it closes the cavity 14 of the shutter body 13 on top; moreover, the plug 41 keeps the resilient elements 39, 40 housed in the shutter body 13 and in the rod-shaped element 24.

[0238] The plug 41 has an upper portion 41a and a lower portion 41 b. The upper portion 41a of the plug 41 corresponds to the upper portion 7 of the shutter 6 described above. A connecting portion 41c, extending along the longitudinal axis X, is between the upper portion 41a and the lower portion 41 b. The upper portion 41a, the lower portion 41b and the connecting portion 41c are substantially cylinder-shaped and extend along the longitudinal axis X; the connecting portion 41c has a diameter smaller than that of the upper portion 41 a and the lower portion 41 b.

[0239] At the lower portion 41 b, the plug 41 has teeth 42 intended for being inserted into the cutouts 19 of the shutter body 13; moreover, at the upper portion 41a, the plug 41 is provided with a thread 12, already described above, where the covering element 5 (not shown in figures 7 and 8) is screwed onto the shutter 6.

[0240] In figure 8, it is possible to observe that the plug 41 is hollow, i.e. has an inner cavity 43 which pass through the plug 41 from side to side along the longitudinal axis X. In practice, the inner cavity 43 extends into the upper portion 41a, the lower portion 41 b and the connecting portion 41c.

[0241] The inner cavity 43 opens to the outside with a hole 47 formed in an upper surface 48 of the plug 41 (in the upper portion 41a) and with an opening 49 formed on the side opposite the upper surface 48, in the lower portion 41 b.

[0242] At the lower portion 41 b, the inner cavity 43 is subdivided into an outer portion 44 and an inner portion 45. The outer portion 44 and the inner portion 45 are concentric and are delimited by an inner wall 46. The inner wall 46 extends in the lower portion 41 b along the longitudinal axis X and is cylinder-shaped; in practice, the inner wall 46 corresponds to the prolongation of the connecting portion 41c inside the lower portion 41 b.

[0243] As shown in figure 8, the inner portion 45 of the inner cavity 43 extends from the lower portion 41b to the upper portion 41a, thus passing through the connecting portion 41c. At the upper portion 41a and the connecting portion 41c, the inner cavity 43 does not have an outer portion.

[0244] The outer portion 44 only extends in the lower portion 41 b indeed and is delimited on top by an upper wall 51 ; the outer portion 44 opens outward at the opening 49.

[0245] It should be highlighted that, in the preferred embodiment, the inner cavity 43 comprises at least one threaded section 50. In other words, the inner cavity 43 has at least one threaded portion, precisely identified as threaded section 50.

[0246] The inner cavity 43 is preferably threaded for a portion thereof extending from the hole 47 (i.e. from the upper surface 48) to about halfway along the connecting portion 41c. It is however clear that the threaded section 50 can extend for a length greater or less than the one shown in the accompanying figures.

[0247] The threaded section 50 comprises a first end, or upper end 50a, and a second end opposite the first, or lower end 50b: the upper end 50a is positioned at the upper surface 48 of the plug 41 , while the lower end 50b is placed at the connecting portion 41c.

[0248] The plug 41 is provided with at least one groove 52, visible in figure 8, extending parallel to the longitudinal axis X in the inner cavity 43, from the lower end 50b of the threaded section 50 to the upper end of the inner wall 46.

[0249] Finally, the shutter 6 further comprises an insert 60 designed for being inserted into the hole 47 of the plug 41.

[0250] The insert 60 is substantially cylinder-shaped and has a diameter compatible with its insertion into the inner cavity 43 of the plug 41 , at the hole 47. The insert 60 extends along the longitudinal axis X and has an upper end 60a and a lower end 60b. The insert 60 has a thread at least at a portion of its outer surface; in practice, the insert 60 comprises at least one threaded portion 61 extending parallel to the longitudinal axis X along a certain length of the upper end 60a.

[0251] Considering the longitudinal axis X, the threaded section 50 of the plug 41 preferably extends for a length greater than the threaded portion 61 of the insert 60.

[0252] The threaded portion 61 allows a user, as will be described below, to screw and unscrew the insert 60 into / from the inner cavity 43 of the plug 41 at the threaded section 50.

[0253] The insert 60 has an upper surface 62 at the upper end 60a. A blind hole 63, into which a user can insert a tool, for example a screwdriver for screwing or unscrewing the insert 60 into / from the hole 47 of the plug 41 , is formed in the upper surface 62.

[0254] As shown in figure 13, the blind hole 63 preferably extends in the upper surface 62 in a direction radial to the longitudinal axis, so as to be able to be engaged by a screwdriver.

[0255] It is however clear that the blind hole 63 can be of any shape which allows a user to insert a tool therein.

[0256] In figure 13, it is possible to see that the insert 60 comprises at least one elastic flap 64 positioned at the lower end 60b of the insert 60 and whose task will be described below.

[0257] In practice, the assembly of the shutter 6 occurs in the following way.

[0258] The first magnet 21 is housed in the groove 20 of the shutter body 13 and the second magnet 37 is fit on the pin 27 in the body 25 of the rod-shaped element 24. The bushing 38, which keeps the second magnet 37 in its seat, is then fit on the pin 27.

[0259] Subsequently, the ring 22 is fit on the rod-shaped element 24 by inserting the stem 26 into the ring 22 itself. Each protrusion 23 is aligned with a respective second concavity 34 and is inserted into a circuit 30. The ring 22 is pushed towards the upper end 25a of the body 25 until the protrusions 23 are positioned in a respective seat 32.

[0260] The ring 22 and the rod-shaped element 24 thus combined are inserted into the shutter body 13, by aligning the ribs 55 of the shutter body 13 with the grooves 29 of the stem 26. The ring 22 and the body 25 of the rod-shaped element 24 rest on the second abutment surface 17. The stem 26 protrudes from below the shutter body 13, i.e. juts out downward from the ring 15.

[0261] The first resilient element 39 and the second resilient element 40 are inserted into the body 25 of the rod-shaped element 24, thus resting on the bushing 38. In particular, the first resilient element 39 and the second resilient element 40 are fit on the pin 27 at their respective lower ends 39b and 40b. The two resilient elements 39 and 40 are coaxial to one another: the first resilient element 39 is positioned outside the second resilient element 40.

[0262] At this point, the plug 41 is fit on the first resilient element 39 and the second resilient element 40 at their respective ends 39a and 40a. In particular, the first resilient element 39 is fit on the inner wall 46 of the plug 41 and is housed in the outer portion 44 of the inner cavity 43; on the other hand, the second resilient element 40 (of a length greater than the first resilient element 39) is inserted into the inner wall 46, i.e. into the inner portion 45 of the inner cavity 43.

[0263] The plug 41 is pushed into the shutter body 13 until the teeth 42 are inserted and stay locked into the respective cutouts 19 of the shutter body 13. The plug 41 rests at the third abutment surface 18.

[0264] The length of the second resilient element 40 is such that, before the insert 60 is inserted into the hole 47, it protrudes from the upper surface 48 of the plug 41 with its first end 40a.

[0265] At this point, the insert 60 is inserted into the hole 47 of the plug 41 and screwed into the threaded section 50 until the upper surface 62 of the insert 60 is flush with respect to the upper surface 48 of the plug 41 . In practice, the insert 60 rests with its lower end 60b on the first end 40a of the second resilient element 40 and pushes the first end 40a into the plug 41 .

[0266] Therefore, when the shutter 6 is completely assembled, the second resilient element 40 is preloaded.

[0267] In particular, the second resilient element 40 is functionally arranged between the plug 41 and the bushing 38 or the body 25 of the rod-shaped element 24; indeed, the second resilient element 40 is functionally arranged between the insert 60 (i.e. the manual calibration means of the overflow mechanism) and the bushing 38, or the body 25 of the rod-shaped element 24.

[0268] The shutter 6 thus assembled is fastened in the body 2 at its lower portion 9: in particular, the shutter 6 is fit on the pin 8 of the cage-shaped body 2b at the opening 28.

[0269] In practice, the stem 26 of the rod-shaped element 24 is fit on the pin 8; for this reason, the stem 26 can also be identified as supporting stem of the shutter 6.

[0270] In light of the description set forth above, the operation of the click-clack mechanism can be better understood. For example, figures 15-18 show the path of the protrusion 23 in the circuit 30 of the rod-shaped element 24. Such path is correlated to the opening and closing of the drain 1 .

[0271] Starting from figure 15, it is possible to see that when the shutter body 6 is in the raised position (and the drain 1 is closed), the protrusion 23 is housed in the seat 32.

[0272] When the user provides to exert a first downward thrust along the longitudinal axis X on the covering element 5 to close the drain 1 , the shutter 6 moves to a first snap position and the protrusion 23 goes into abutment in the first concavity 33, as shown in figure 16; simultaneously, (even if not shown in the figure) the first resilient element 39 and the second resilient element 40 are compressed.

[0273] As is possible to see in figure 17, once the user ceases to exert the downward thrust, the shutter 6 automatically raises itself from the snap position to the lowered position, which corresponds to the protrusion 23 housed in the recess 36. The automatic raising of the shutter from the first snap position to the lowered position is due to the thrust exerted by the first resilient element 39 and the second resilient element 40. When the shutter 6 is in this position, the drain 1 is in the open configuration. The shutter 6 remains in the lowered position until the user provides to exert a second downward thrust.

[0274] Indeed, if the user wants to bring back the drain to the closed configuration, he / she must exert a second downward thrust along the longitudinal axis X on the covering element 5. In this circumstance, the first resilient element 39 is compressed a second time and the shutter 6 moves to a second snap position.

[0275] Such position is shown in figure 18. In figure 18, it is possible to see that when the drain 1 is in the second snap position, the protrusion 23 is positioned in the second concavity 34.

[0276] Once the snap position has been reached, the user can stop exerting the downward thrust and, this way, the first resilient element 39 cooperates with the second resilient element 40 to bring back the shutter 6 to the raised position (figure 15), thus closing the drain 1.

[0277] Comparing figures 15-18 to one another, it is possible to observe that when the shutter 6 switches from the raised position to the lowered position, and vice-versa, the rod-shaped element 24 stays stationary with respect to the cage-shaped body 2b, whereas the shutter body 13 and the ring 22 and plug 41 telescopically move on the longitudinal axis X from the raised position to the lowered position, and vice-versa, with respect to the rod-shaped element 24.

[0278] As an alternative to the click-clack mechanism shown in the accompanying figures, it is possible to configure the click-clack mechanism according to what is described, for example, in EP 1338707.

[0279] It is clear however that it is possible to configure the click-clack mechanism according to any other teaching of the known art.

[0280] It is possible, for example, to provide a series of teeth inside the ring 22 and a series of abutment surfaces, complementary to the teeth, on the inner surface of the shutter body 13, at different heights. Moreover, it is possible to provide a profile complementary to the teeth also on top of the rod-shaped element 24

[0281] As mentioned above, the shutter 6 further integrates an overflow mechanism. The click-clack mechanism and the overflow mechanism are both integrated into the shutter 6, i.e. are provided in the shutter 6.

[0282] For example, figures 5 and 6 show the drain 1 in which the overflow mechanism is triggered.

[0283] It is indeed possible to notice that the shutter 6 is in an intermediate position between the raised position shown in figures 1 and 2 and the lowered position shown in figures 3 and 4.

[0284] In practice, as mentioned above, when the pressure exerted by the water present in the sanitary fixtures on the covering element 5 reaches a threshold value, the shutter 6 is automatically lowered (i.e. without requiring a user to exert a thrust on the covering element 5), thus allowing the drain 1 to release the excess of water.

[0285] Once the pressure exerted by the water returns below the threshold level, the shutter 6 automatically returns to the raised position, thus closing the drain 1 .

[0286] When the overflow mechanism is triggered, the shutter 6 moves downward on the longitudinal axis X. In particular, the shutter body 13 and the plug 41 move downward along the longitudinal axis, while the rod-shaped element 24 stays stationary.

[0287] The overflow mechanism integrated into the shutter 6 shown in the accompanying figures is of the hybrid type, i.e. mechanical and magnetic. Returning to the components described with reference to figures 7 and 8, the shutter 6 indeed comprises the second resilient element 40 and the first magnet 21 and the second magnet 37.

[0288] As mentioned above, the second resilient element 40 is functionally arranged between the rod-shaped element 24 and the plug 41 , the first magnet is housed in the shutter body 13, while the second magnet 37 is housed in the rod-shaped element 24. The second magnet 37 is arranged between the first magnet 21 and the second resilient element 40, i.e. considering the longitudinal axis X, the second magnet 37 is at an intermediate height between the first magnet 21 (which lies lower) and the second resilient element 30 (which lies higher).

[0289] The first magnet 21 and the second magnet 37 have opposite polarity and therefore attract one another.

[0290] When the pressure of the water in the sanitary fixture reaches a preset threshold value, the second resilient element 40 yields and the first magnet 21 moves away from the second magnet 37, with the consequent lowering of the shutter 6.

[0291] In this circumstance, the pressure of the water in the sanitary fixture overcomes both the thrust exerted by the second resilient element 40 and the attractive force between the magnets 21 and 37.

[0292] When the water pressure drops below the threshold value, the second resilient element extends and the magnets 21 and 37 move closer again; this way, the shutter 6 is automatically brought back to a raised position.

[0293] As an alternative, it is possible to make an exclusively magnetic overflow mechanism, i.e. in which the second resilient element 40 is replaced by a couple of magnets that repel one another. For example, it is possible to position a magnet at the lower end 60b of the insert 60 with the same polarity of the second magnet 37 housed in the rod-shaped element 24. Or, it is possible to make a purely mechanical overflow mechanism, in which the magnets 21 and 37 are replaced by a resilient element.

[0294] It is useful to be able to adjust the calibration of the overflow mechanism, i.e. to be able to selectively configure the overflow mechanism so that, depending on the need of the user and of the sanitary fixture in which the drain must be mounted, it is possible to decide, from time to time, at which water pressure threshold value the overflow mechanism must be triggered.

[0295] Manual calibration means of the overflow mechanism are thus provided.

[0296] In the preferred embodiment described herein, the manual calibration means correspond to the insert 60; in practice, the calibration of the overflow mechanism occurs by screwing or unscrewing the insert 60 into / from the plug 41.

[0297] The calibration of the overflow mechanism is described hereunder with reference to figures 9-12.

[0298] In figures 9 and 10, the overflow mechanism is in a first configuration of use, which corresponds to the insert 60 screwed into the plug and with its upper surface 62 flush with respect to the upper surface 48 of the plug 41 ; indeed, in figure 10, it is possible to observe that the upper surface 62 of the insert 60 lies on the same lying plane of the upper surface 48 of the plug 41 . Moreover, the insert 60 is screwed at the upper end 50a of the threaded section 50.

[0299] In practice, the insert 60 is at the maximum distance from the bushing 38 on which the second resilient element 40 rests. The second resilient element can (also if preloaded in the shutter 6) thus be considered in an extended configuration.

[0300] When a user inserts a tool into the blind hole 63 and rotates the insert 60 in a first direction, for example clockwise, the insert 60 is screwed into the threaded section 50 down to the lower end 50b of the threaded section 50 itself. This way, the shutter 6 is brought to a second configuration of use. The shutter 6 in this second configuration is shown in figures 11 and 12.

[0301] In practice, the insert 60 is at the minimum distance from the bushing 38 on which the second resilient element 40 rests. The second resilient element 40 is thus in a compressed configuration.

[0302] When the shutter 6 is in the second configuration, a greater force is necessary for compressing the second resilient element 40; this means that by screwing the insert 60 down to the lower end 50b of the threaded section 50, the overflow mechanism is triggered at a greater pressure threshold value than the threshold value corresponding to the shutter 6 in the first configuration.

[0303] In practice, by rotating the insert 60 from the first configuration to the second configuration, the pressure threshold value, at which the overflow mechanism is triggered, is increased.

[0304] If a user inserts the tool into the blind hole 63 and rotates the insert 60 in a second direction opposite the first, for example anticlockwise, the insert 60 is unscrewed from the plug 41 and is brought back to the first configuration.

[0305] For example, in the first configuration of use, the overflow mechanism is triggered when the water reaches a height of 7 cm, whereas in the second configuration of use, the overflow mechanism is triggered when the water reaches a lower height, i.e. of 12 cm.

[0306] Obviously, the overflow mechanism can be configured so that the overflow mechanism is triggered when the water reaches a different height than those set forth above in the first configuration and the second configuration.

[0307] It should be specified that the passage from the first configuration of use to the second configuration of use, and vice-versa, is reversible, in the sense that, after screwing the insert 60 clockwise from the first configuration to the second configuration, it is possible to return to the first configuration by unscrewing the insert 60 counterclockwise, i.e. in a direction opposite the clockwise direction.

[0308] Although not shown in the figures, it is possible to screw (or unscrew) the insert 60 in a plurality of intermediate configurations between the first configuration and the second configuration. The pressure threshold values between the minimum one and the maximum one correspond to this plurality of intermediate configurations.

[0309] In order to understand how much he is changing the calibration of the overflow mechanism, the user can rely on the number of clicks he detects when rotating the insert 60 in the plug 41 . Indeed, as mentioned above, the insert 60 has an elastic flap 64 which snaps each time the insert 60 makes a 360°, i.e. complete, rotation in the plug 41 : at each rotation completed, the elastic flap 64 intercepts the groove 52 of the plug 41 and the user perceives a click. For example, at each rotation completed, the insert 60 is screwed or unscrewed into / from the plug 41 by 1.5 mm, which corresponds to about a 1-cm variation in the water column which triggers the overflow mechanism. Therefore, if the user intends to change the height of the water column by 2 cm at which the overflow mechanism is triggered, he / she can rotate the insert 60 until perceiving two clicks in the plug 41 . It is clear that it is possible to provide a greater number of grooves and / or elastic flaps so as to warn a user also about lower height changes in the water column, i.e. changes of 0.5 cm.

[0310] In figures 10 and 12, it is clear that the insert 60, i.e. the manual calibration means of the overflow mechanism, is provided on the upper portion 7 of the shutter 6. In practice, when the covering element 5 is separated from the shutter 6, a user can act on the insert 60 positioned on the upper portion 7 of the shutter 6, i.e. on the upper surface 48 of the plug 41 , to adjust the calibration of the overflow mechanism.

[0311] In this context, the manual calibration means can be considered positioned on the upper portion 7 of the shutter 6 also when screwed into the second configuration of use shown in figure 12.

[0312] Therefore, if the drain 1 is already installed in a sanitary fixture, the user does not have to disassemble the drain 1 or take down the shutter 6 in order to be able to act on the manual calibration means of the overflow mechanism: it is sufficient for him / her to unscrew the covering element 5 and insert a tool into the hole 63 present on the upper portion 7 of the shutter.

[0313] Unlike the solutions described with reference to the known art, the drain 1 allows a user to easily and quickly adjust the overflow mechanism also if the drain 1 has already been installed in a sanitary fixture.

[0314] A further advantage of the drain 1 relates to the fact that, when the covering element 5 is coupled to the shutter 6, the insert 60 is not accessible to a user. In practice, during normal use of the drain 1 , a user does not notice the insert 60 and cannot change the pressure threshold value at which the overflow mechanism is triggered, because the insert 60 is concealed by the covering element.

[0315] This can be advantageous to prevent inexpert users or children from trying to change the calibration of the overflow mechanism without particular knowledge of what they are doing, or to prevent the calibration of the overflow mechanism from being accidentally changed when cleaning the sanitary fixture or by a vortex of water forming in the drain pipes.

[0316] Indeed, regardless of the triggering of the click-clack and overflow mechanisms, the drain 1 can be configured in two states.

[0317] A first state, also defined as state of use, corresponds to the drain 1 with the covering element 5 coupled to the shutter 6 at its upper portion 7. The drain 1 is shown in said first state, for example, in figures 1 and 2.

[0318] In figure 2, it is possible to notice that the covering element 5 is screwed at the thread 12 of the plug 41 and that the insert 60 is covered by the covering element 5 itself. Indeed, when the covering element 5 is coupled to the plug 41 , the covering element 5 covers the upper surface 48 of the plug 41 and, thus, also the insert 60.

[0319] Thus, when the drain 1 is in the first state, the blind hole 63 of the insert 60 is also inaccessible to a user, who cannot thus proceed to change the calibration of the overflow mechanism by inserting a tool therein for changing the calibration of the overflow mechanism.

[0320] When the drain 1 is in the second state instead, the covering element 5 is separated from the shutter 6, i.e. is not screwed onto the plug 41 .

[0321] The shutter 6 devoid of the covering element 5 coupled thereto is shown, for example, in figure 10.

[0322] When the covering element 5 is separated from the shutter 6, the insert 60 is accessible to a user, who can thus change the calibration of the overflow mechanism by inserting a tool into the blind hole 63.

[0323] By rotating the covering element 5 with respect to the shutter 6, it is thus not possible to change the calibration of the overflow mechanism because, in the relative movements between the shutter 6 and the covering element 5, the insert 60 is integral with the shutter 6. This circumstance is an advantage because it ensures that common users of the sanitary fixture cannot easily change the calibration of the overflow mechanism, for example, by bringing it from the first configuration to the second configuration. As a matter of fact, in order to change the calibration of the overflow mechanism, a user must know how to separate the covering element 5 from the shutter 6.

[0324] With reference to figures 19-46, a second embodiment of a drain according to the invention is described hereunder.

[0325] The drain is denoted by the reference number T and has, in its most general aspects, the characteristics described above with reference to the drain 1. In particular, it has a body 2’ comprising a cylindrical body 2’a and a cageshaped body 2’b (visible, for example, in figure 20), a threaded portion 3’ and a rosette 4’.

[0326] The drain further comprises a covering element 5’ which can be screwed to a shutter 6’ at the upper portion 7’ of the shutter 6' itself.

[0327] The drain T indeed comprises a shutter 6’ extending along the longitudinal axis X’ and designed for opening and closing the passage of the water through the drain 1 . The shutter 6’ is housed in the body 2’ of the drain T; in the embodiment described herein, the shutter 6’ is housed in the cylindrical body 2’a and in the cage-shaped body 2’b.

[0328] In the sectional figure 20, it is possible to observe that the shutter 6’ is housed in the cage-shaped body 2’b and is hinged on a pin 8’ of the cageshaped body 2’b at a lower portion 9’ thereof. The pin 8’ extends along the longitudinal axis X’.

[0329] The shutter 6’ is movable with respect to the body 2’ on the longitudinal axis X’, between a raised position corresponding to the drain T closed, and a lowered position corresponding to the drain T open.

[0330] In particular, the shutter 6’ is shown in a raised position in figures 19 and 20, whereas the shutter 6’ is shown in a lowered position in figures 21 and 22. In the sectional views shown in figures 20 and 22, it is possible to observe that the body 2’ delimits a mouth 10’ for water and at which water can flow from the sanitary fixture to the drain pipes through the drain 1 .

[0331] As shown in figure 20, when the shutter 6’ is in a raised position, the mouth 10’ is closed, i.e. it is intercepted by the shutter 6’; in this circumstance, the water contained in the sanitary fixture cannot be drained through the drain 1’.

[0332] On the other hand, figures 21 and 22 show that when the shutter 6’ is in a lowered position, the mouth 10’ is open (i.e. is not intercepted by the shutter 6’) and the water contained in the sanitary fixture can be drained through the drain T.

[0333] For such purpose, the shutter 6 ’ can be equipped with a gasket 11', for example of the O-ring type, especially intended for closing the mouth 10'.

[0334] The drain T comprises a so-named click-clack mechanism and, in particular, the click-clack mechanism is integrated into the shutter 6’ at the upper portion 7’.

[0335] In general terms, the click-clack mechanism functions similarly to what has been described above and, unless in case of different characteristics, what is described above with reference to the first embodiment can be extended to the second embodiment.

[0336] As mentioned above, the shutter 6’ is combined with a covering element 5’. The covering element 5’ is coupled to the upper portion of the shutter 6’. For example, the covering element 5’ can be screwed into a thread 12’ of the shutter 6’. It is precisely at the covering element 5’ that a user can exert a thrust on the shutter 6’, always directed downward, to bring it to the lowered position or the raised position and thus to open or close the drain T.

[0337] Click-clack mechanisms, i.e. mechanisms for the snap opening and closing of the drains, are known in the art: examples are described in the documents of the known art set forth above. As known, click-clack mechanisms are mechanisms which are triggered in response to a force exerted by a user, i.e. they are not automatic mechanisms.

[0338] For the purposes of the present invention, it is not specified which specific click-clack mechanism is incorporated in the drain 1', since different click-clack mechanisms are known.

[0339] By way of example, the click-clack mechanism integrated into the shutter 6’ of the drain T will be described hereunder.

[0340] In addition to a click-clack mechanism, the shutter 6’ further integrates an overflow mechanism, i.e. a mechanism which allows the shutter 6 ’ in a raised position to automatically lower when the pressure of the water column acting on the shutter 6’ reaches a preset threshold value. This way, the drain T can discharge sanitary fixture excess water. When the value of the pressure drops below the preset threshold value, the shutter automatically returns to the raised position, thus closing the drain T.

[0341] Unlike the triggering of the click-clack mechanism which requires the intervention of a user, the operation of the overflow mechanism is thus automatic, i.e. does not require a user to trigger it.

[0342] The operational principle of the overflow mechanism of the drain T is thus similar to the one described with reference to the known art.

[0343] For example, the drain T with the overflow mechanism triggered with the shutter 6’ in a lowered position is depicted, for example, in figures 23 and 24. As known, the triggering of the overflow mechanism does not lead to the triggering of the click-clack mechanism because the pressure of water in a sanitary fixture is never sufficient to push the shutter 6’ up to the snap position.

[0344] A peculiarity of the second embodiment is that the triggering of the overflow mechanism does not involve the lowering of the portion of the covering element 5’ but the lowering of the shutter body 13’, because the covering element 5’ remains stationary indeed.

[0345] As a matter of fact, by comparing figure 24 with figure 22, it is possible to observe that, although the shutter 6’ is in the lowered position in both cases, the upper portion 7’ and the covering element 5’ of figure 22 are more proximal to the pin 8’ than in figure 24.

[0346] Since the triggering of the overflow mechanism is solely determined by the pressure exerted by the water column on the shutter 6’ and not on the covering element 5’ as well, the overflow mechanism is more accurate because its triggering is not affected by the weight of the covering element 5’ which presses on the upper portion 7’.

[0347] The operation of the drain T can be illustrated more precisely after having described the components shown in figures 25-46.

[0348] In particular, figure 25 shows an exploded view of the shutter 6’.

[0349] The shutter 6’ comprises a shutter body 13’, also shown in figures 29, 30, 31. The shutter body 13’ is the component, or one of the components, of the shutter 6’ which is displaced between the raised position and the lowered position in response to the triggering of the overflow mechanism or the clickclack mechanism.

[0350] Thus, what is described above in general terms with reference to the movements of the shutter from the raised position to the lowered position may specifically refer to the shutter body 13’.

[0351] As shown in figure 30, the shutter body 13’ is hollow, i.e. comprises a cavity 14’ extending along the longitudinal axis X’.

[0352] At the lower end 13’b, the shutter body 13’ comprises a ring 15’ provided with a groove 20’ at which a first magnet 2T (visible in figure 25) constituting one of the components of the overflow mechanism is positioned.

[0353] At the upper end 13’a, the shutter body 13’ has blind holes, i.e. cutouts 19’. Four cutouts 19’ are preferably provided.

[0354] In figures 25, 26, 27 and 28, it is possible to see that the shutter 6’ further comprises a rod-shaped element 24’. The rod-shaped element 24’ comprises a cup-shaped body 25’ and a rod 26’, or stem 26’, jutting out downward from the body 25’ along the longitudinal axis X'. The stem 26’ preferably extends inside the body 25’ and forms a pin 27’ visible in figure 27. The stem 26’ is preferably hollow and has an opening 28’ at its lower end 26’b. The shutter 6’ is fit on the pin 8’ of the cage-shaped body 2’b precisely at the opening 28’ of the stem 26’.

[0355] One or more magnets are housed inside the body 25’.

[0356] A magnet, identified as second magnet 37’ (shown in figure 25), and a spring-holder element 38’ are preferably housed in the body 25’. The second magnet 37’ and the spring-holder element 38’ are fit on the pin 27’ of the rodshaped element 24’. The spring-holder element 38’ is shown in figures 25, 32 and 35.

[0357] The second magnet 37’ is also part of the overflow mechanism.

[0358] The spring-holder element 38’ is identified with such name since a resilient, or elastic, element is fit thereon, identified as second resilient element 40’ (visible in figure 25) and involved in triggering the overflow mechanism. The spring-holder element 38’ has a lower portion 38’b at which there is a ring- shaped surface 22’ on which the second resilient element 40’ rests. A pin 23’, of a diameter smaller than the ring-shaped surface 22’ and on which the second resilient element 40’ is fit, juts out from the ring-shaped surface 22’.

[0359] The second resilient element 40’ has an upper end 40’a and a lower end 40’b.

[0360] At the lower end 40’b, the second resilient element 40’ is housed in the body 25’ of the rod-shaped element 24’ and rests on the spring-holder element 38’. At the respective upper end 40’a, the second resilient element 40’ is housed in a plug 41 ’ of the shutter 6’ shown in figures 25, 34, 35.

[0361] In practice, the plug 4T is named this way because it closes the cavity 14’ of the shutter body 13’ on top.

[0362] The plug 4T has an upper portion 41’a and a lower portion 41’b. When the drain T is closed, the upper portion 41’a of the plug 4T is positioned at the upper portion 7’ of the shutter 6’ described above.

[0363] At the lower portion 41’b, the plug 4T has teeth 42’ intended for being inserted into the cutouts 19’ of the shutter body 13’; moreover, at the upper portion 41’a, the plug 4T is provided with one or more through holes 70’. As shown in figure 35, the plug 4T is preferably provided with two through holes 70’ formed in opposite positions.

[0364] In figure 35, it is possible to observe that the plug 41’ is hollow, i.e. has an inner cavity 43’ which passed through the plug 41’ from side to side along the longitudinal axis X’.

[0365] The inner cavity 43’ opens outward, at the upper portion 41 ’a, with a hole 47’ at which the through holes 70’ are formed.

[0366] The plug 41’ has a ring 7T extending radially with respect to the longitudinal axis X’ and which has an upper surface 72’.

[0367] It is possible to place the gasket 11’ mentioned above at a groove 73’ provided in the ring 7T.

[0368] It is precisely at this upper surface 72’ that, in use, the pressure of the water column in the sanitary fixture presses and which pressure is able to trigger the overflow mechanism if it exceeds a preset threshold level. For this reason, it is possible to state that the pressure of the water column which triggers the overflow mechanism presses on the shutter 6’.

[0369] The drain T further comprises an insert 60’ designed for being inserted into the hole 47’ of the plug 41’. The insert is shown in figures 25, 43, 44, 45 and 46.

[0370] The insert 60’ is substantially cylinder-shaped and has a diameter compatible with its insertion into the inner cavity 43’ of the plug 41’, at the hole 47’.

[0371] The insert 60’ extends along the longitudinal axis X’ and has an upper end 60’a and a lower end 60’b.

[0372] The insert 60’ is provided with one or more teeth 74’ (preferably two teeth 74’) designed for being inserted into the through holes 70’ of the plug 41’.

[0373] The teeth 74’ allow to reversibly couple the insert 60’ to the plug 41’.

[0374] The insert 60’ has an upper surface 62’ at the upper end 60’a. A blind hole 63’, into which a user can insert a tool, for example a screwdriver for removing the insert 60’ from the shutter, i.e. for separating it from the shutter itself, is formed in the upper surface 62’. In this circumstance, the insert 60’ is removed from the through holes 70’ of the plug 41’.

[0375] The insert 60’ extends for a certain length, for example 14.5 mm.

[0376] Generally, as far as the second embodiment is concerned, an insert portion 60’ comprised between one or more teeth 74’ and the lower end 60’b and denoted by the reference number 75’ in figure 44, can be identified.

[0377] The second resilient element 40’ extends between the lower end 60’b of the insert 60’ and the spring-holder element 38’. Generally, as far as the second embodiment is concerned, by replacing the insert 60’ with another insert (not shown in the figure) of a greater length or a portion 75’ of a length greater than that of the insert 60’, it is possible to change the calibration of the overflow mechanism. As an alternative, it is possible to replace the insert 60’ with another insert of a length or a portion 75’ of a smaller length. In the first case, the overflow mechanism is triggered when the water pressure reaches a greater threshold value, whereas in the second case, when the water pressure reaches a threshold value less than the one which triggers the overflow mechanism with the insert 60’ described above. For example, the additional inserts usable for changing the calibration of the overflow mechanism can have a length of 8 cm or 10 cm.

[0378] Generally, in this second embodiment, a user can change the calibration of the overflow mechanism by removing the insert 60’ from the shutter and combining a different insert with the shutter, i.e. of a length greater or less than that of the insert 60’ (the difference can be determined by the different length of the portion 75’).

[0379] The drain T further comprises some components which constitute the click-clack mechanism of the shutter. These components are positioned at the upper portion 7’ of the shutter 6’.

[0380] In particular, the drain T comprises a flange 80’ shown in figures 25, 36, 37 and 38. The flange 80’ comprises an outer ring 8T at which the flange 80’ rests on the body 2’ of the drain 1 , and an inner ring 82’ supported by the outer ring 8T by means of feet 83’. The inner ring 82’ has a diameter smaller than the one of the outer ring 8T and is positioned at a height, considered with respect to the longitudinal axis X’, slightly greater than that of the outer ring 8T.

[0381] In figures 37 and 38, it is possible to notice that there is a toothed profile 84’ at the inner surface 82’a of the inner ring 82’.

[0382] Reliefs, or teeth 85’, provided on the outer surface of the bearing 86’ shown in figures 25, 39 and 40, abut at such toothed profile 84’.

[0383] The bearing 86’ with its teeth 85’, the flange 80’ with its tooted profile 84’, and the first resilient element 39’ (shown in figure 25) constitute the click-clack mechanism according to the principles already known in the known art.

[0384] Finally, the shutter 6’ comprises a support of the covering element, denoted by the reference number 87’ and shown in figures 25, 41 and 42.

[0385] The support of the covering element will henceforth be identified with the name “support”. The support 87’ is provided with a thread 12’, already described above, at which the covering element 5’ is screwed.

[0386] The support 87’ is designed for resting on the flange 80’ and, in particular, on the feet 83’.

[0387] The support 87’ is provided with an upper surface 48’ which, when the covering element 5’ is screwed at the thread 12’, stays covered by the covering element 5’ itself.

[0388] At the upper surface 48’, the support 87’ has a through hole 88’ which can be used by a user for accessing the blind hole 63’ of the insert 60’, inserting a tool and separating the insert 60’ from the shutter 6’. A user can insert another insert of a length different from that of the insert 60’ through the same through hole 88’, so as to change the calibration of the overflow mechanism.

[0389] In light of the description set forth above, the operation of the click-clack mechanism can be better understood. As mentioned above, figures 19-20 show the drain T closed, whereas figures 21-22 show the drain T open following the triggering of the click-clack mechanism.

[0390] In particular, by comparing figure 20 and 22, it is possible to observe that the first resilient element 39’ is compressed in figure 22, a sign that the click- clack mechanism was triggered.

[0391] In this circumstance, the support 87’ is lowered on the flange 80’; indeed, in figure 20, the support 87’ is positioned at an axial height greater than that of the inner ring 82’ of the flange 80’, while it is at about the same axial height in figure 22.

[0392] Consequently, to the lowering of the upper portion 7’, the lowering of the plug 4T and the shutter body 13’ is also noticed.

[0393] In practice, when the drain switches from the closed configuration to the open configuration, and vice-versa, the displacement of the shutter body 13’ from the raised position to the lowered position, and vice-versa, is noticed.

[0394] In practice, following the triggering of the click-clack mechanism, the components of the drain T that stay stationary are, in addition to the body 2’, the flange 80’ and the rod-shaped element 24’.

[0395] As mentioned above, the shutter 6’ further integrates an overflow mechanism. The click-clack mechanism and the overflow mechanism are both preferably integrated into the shutter 6’, i.e. are provided in the shutter 6’.

[0396] As mentioned above, figures 19 and 20 show the drain T closed, whereas figures 23 and 24 show the drain T open following the triggering of the overflow mechanism.

[0397] Indeed, in figure 24, it is possible to observe that the shutter body 13’ and the plug 4T are in a lowered position compared with their position in figure 20 and that the second resilient element 40’ is compressed.

[0398] Unlike what is described above with reference to figure 22, the upper portion 7’ of the shutter 6’ did not move to a lowered position.

[0399] Indeed, the position of the covering element 5’ and the support 87’ with respect to the flange 80’ is unchanged following the triggering of the overflow mechanism. It can indeed be noticed that, by comparing the drain T closed with the drain T open following the triggering of the overflow mechanism, the support 87’ did not change its axial position with respect to the inner ring 82’ of the flange 80’. In practice, following the triggering of the overflow mechanism, the lowering of the shutter body 13’ and the plug 41’ is noticed, but not of the support 87’ (as a matter of fact, the first resilient element 39’ is not compressed).

[0400] For example, EP 1 617 000 describes a drain in which the upper portion of the shutter does not lower following the triggering of the overflow mechanism (figure 3). Thus, a technician of the field can refer to EP 1 617 000 to make a drain in which the click-clack mechanism is integrated into the upper portion of the shutter and in which this upper portion does not suffer axial displacement in response to the triggering of the overflow mechanism.

[0401] As mentioned above, the triggering of the overflow mechanism is determined by reaching a pressure threshold value exerted on the shutter by the water column which, in use, presses on the shutter 6’ but not on the covering element 5’. In particular, such pressure is exerted on the upper surface 72’ of the plug 41’. A technician of the field could make the shutter body 13’ and the plug 41’ in a different way than the one described and make it so that the pressure able to trigger the overflow mechanism is exerted on an upper surface of the shutter body 13’.

[0402] Generally, the magnets 21’ and 37’ cooperate to bring back the shutter body 13’ from the lowered position to the raised position following the triggering of the click-clack mechanism or the overflow mechanism.

[0403] It is useful to be able to adjust the calibration of the overflow mechanism, i.e. to be able to selectively configure the overflow mechanism so that, depending on the need of the user and of the sanitary fixture in which the drain must be mounted, it is possible to decide, from time to time, at which water pressure threshold value the overflow mechanism must be triggered.

[0404] As described for the drain 1 , manual calibration means of the overflow mechanism are therefore also provided in the drain T.

[0405] In the preferred embodiment described herein, the manual calibration means correspond to the insert 60’; in practice, the calibration of the overflow mechanism occurs by replacing the insert 60’ with another insert of different length.

[0406] In particular, starting from a drain T closed as shown in figure 20, a user can separate the covering element 5’ from the shutter 6’ by unscrewing it from the thread 12’ of the support 87’, can insert a tool at the through hole 88’, separate the insert 60’ from the shutter 6’ and replace the insert 60’ with a different insert which extends along the longitudinal axis X’ for a different length (longer or shorter).

[0407] In particular, this further insert could have a different length of the portion 75’.

[0408] Generally, if an insert provided with a portion 75’ of greater length than that of the insert 60’ is inserted during the calibration of the overflow mechanism, a greater force is then required to compress the second resilient element 40’; this means that the overflow mechanism is triggered at a pressure threshold value greater than the threshold value corresponding to the shutter 6’ with the insert 60’.

[0409] Otherwise, if the portion 75’ is of smaller length, the pressure threshold value is less than the threshold value determined by the insert 60’.

[0410] This because the second resilient element 40’ is functionally arranged between the insert 60’ and the rod-shaped element 24’, which always stays stationary both when the click-clack mechanism is triggered and when the overflow mechanism is triggered.

[0411] In figure 20, it is clear that the insert 60’, i.e. the manual calibration means of the overflow mechanism, is provided on or at the upper portion 7’ of the shutter 6’. In practice, when the covering element 5’ is separated from the shutter 6’, a user can replace the insert 60’ positioned on the upper portion 7’ of the shutter 6’, i.e. on the upper surface 48’ of the plug 87’, to adjust the calibration of the overflow mechanism.

[0412] If the drain T is already installed in a sanitary fixture, the user does not have to disassemble the drain T or take down / disassemble the shutter 6’ in order to be able to act on the manual calibration means of the overflow mechanism: it is sufficient for him / her to unscrew the covering element 5’ and replace the insert 60’.

[0413] Unlike the solutions described with reference to the known art, the drain T allows a user to easily and quickly adjust the overflow mechanism also if the drain 1 has already been installed in a sanitary fixture.

[0414] A further advantage of the drain T relates to the fact that, when the covering element 5’ is coupled to the shutter 6’, the insert 60’ is not accessible to a user. In practice, during the normal use of the drain T, a user does not notice the insert 60’ and cannot change the pressure threshold value at which the overflow mechanism is triggered, because the insert 60’ is concealed by the covering element 5’.

[0415] This can be advantageous to prevent inexpert users or children from trying to change the calibration of the overflow mechanism without particular knowledge of what they are doing, or to prevent the calibration of the overflow mechanism from being accidentally changed when cleaning the sanitary fixture or by a vortex of water forming in the drain pipes.

[0416] With reference to figures 47, 48, 49, a third embodiment of a drain according to the present invention is described and denoted by the reference number 1”.

[0417] In particular, figures 47-49 show an elevation and sectional view of the drain 1” with respect to a sectional plane containing the longitudinal axis X” (shown in figure 47). The drain 1” is closed in figure 47, the drain 1” is open in response to the triggering of the click-clack mechanism in figure 48 and the drain 1” is open in response to the triggering of the overflow mechanism in figure 49.

[0418] The drain 1” can be seen as a variant of the drain T and, as far as the making of the click-clack mechanism and its general features (features of the body 2” of the drain, of the covering element 5”, etc.) are concerned, it is similar to that drain. What is set forth above can thus also be extended to this embodiment.

[0419] The drain 1” comprises a shutter 6” which has an upper portion 7” and a lower portion 9”: the covering element 5” is screwed onto the shutter at the upper portion 7” and the manual calibration means of the overflow mechanism, i.e. the insert 60”, are arranged on the upper portion 7”.

[0420] The shutter 6” is fastened to the shutter body 2” at its lower portion 7”.

[0421] Unlike what is described above with reference to the first and the second embodiments, the shutter body and the plug of the shutter are made in a single piece which will be defined as shutter body 13”.

[0422] The shutter body 13” is movable between a raised position corresponding to the drain 1” closed (see figure 47), and a lowered position corresponding to the drain 1” open (see figure 48).

[0423] The shutter body 13” extends along the longitudinal axis X” and comprises a circular-shaped and hollow stem 26" (cavity 93”) which defines an undercut 91” extending circularly about the longitudinal axis X”.

[0424] The stem 26” extends between an upper end 26”a and a lower end 26”b: the cavity 93” defined by the stem extends between these two ends of the stem 26”.

[0425] The shutter body 13” has an enlarged portion 92” intended for closing the passage of water in the drain 1” and from which the stem 26” extends downward. In particular, the upper end 26”a of the stem 26” is precisely at a lower surface 92”b of the enlarged portion 92”.

[0426] The shutter 6” further comprises a bellows-shaped element 90” constrained to the body 2” of the drain at the lower end and to the shutter body 13” at the upper end, at the lower surface 92”b of the enlarged portion 92”.

[0427] Moreover, the enlarged portion 92” has an upper surface 92”a opposite the lower surface 92”b. At the upper surface 92”a, the shutter body 13” has a pin 27”, i.e. a pin-shaped portion, extending in the direction opposite the stem 26”, i.e. upward.

[0428] The pin 27” is hollow, i.e. has a cavity 94” in which a resilient element 40” is positioned, identified as second resilient element 40”.

[0429] It is indeed possible to notice that the shutter 6” has a first resilient element 39” at the upper portion 7” which is part of the click-clack mechanism.

[0430] In practice, the second resilient element 40” is arranged between the insert 60” and the enlarged portion 92” and is one of the components of the overflow mechanism. The second resilient element 40” is preloaded in the shutter 6”.

[0431] The overflow mechanism further comprises a magnetic element and a ferromagnetic element.

[0432] In figures 47-49, it is possible to observe that the body 2” has a pin 8 extending along the longitudinal axis X” and on which the shutter body 13” is fit at the stem 26”. The pin 8” is provided with a cylinder-shaped ferromagnetic element 95” extending along the longitudinal axis X”. The ferromagnetic element 95” has an upper end 95”a and a lower end 95”b. The upper end 95”a is at the top of the pin 8”, in a position distal from the base of the pin 8”. The lower end 95”b is positioned near the base of the pin 8”, although spaced therefrom.

[0433] At the stem 26’ there is a tubular magnetic element 96” extending lengthwise on the longitudinal axis X”.

[0434] The magnetic element 96” and the ferromagnetic element 95” are coaxial and the former surrounds, or is arranged about, the latter. The magnetic element 96” is movable along the longitudinal axis X” relative to the ferromagnetic element 95”, which stays stationary.

[0435] The magnetic element 96” has an upper end 96”a and a lower end 96”b. The magnetic element 96” is arranged at the undercut 91”, i.e. between the undercut 91” and the lower end 26”b of the stem 26”.

[0436] The ferromagnetic element 95” and the magnetic element 96” have the same length, i.e. they extend for the same length relative to the longitudinal axis X”.

[0437] The ferromagnetic element 95” can possibly be arranged on a component of the shutter 6” which is fit on the pin 8”; as an alternative, it is moreover possible to make the component 95” of magnetic material and the component 96” of ferromagnetic material.

[0438] As shown in figure 47, when the drain 1” is closed, the shutter body 13” is in a raised position and closes the passage of water through the drain by abutting with the gasket 11” on the body 2” of the drain 1”. In this circumstance, the ferromagnetic element 95” and the magnetic element 96” are positioned at the same height, i.e. they are facing one another. In practice, the upper end 95”a of the ferromagnetic element 95” is at the same height than the upper end 96”a of the magnetic element 96”. The same is valid for the respective lower ends 95”b and 96”b.

[0439] When the drain 1 is closed, the second resilient element 40” exerts a thrust on the shutter body 13”, directed downward, i.e. towards the pin 8”. This thrust does not cause a displacement of the shutter body 13” because this thrust is counterbalanced by the attractive force between the ferromagnetic element 95” and the magnetic element 96”.

[0440] When a user exerts a downward thrust on the covering element 5” to open the drain 1”, by activating the click-clack mechanism, he / she causes the shutter body 13” to be lowered, as shown in figure 48.

[0441] As described with reference to the second embodiment, since the clickclack mechanism was triggered, the upper portion 7” moves to a lowered position and the first resilient element 39” is compressed.

[0442] In this circumstance, the ferromagnetic element 95” stays stationary (because positioned on the pin 8”), while the magnetic element 96” is lowered until almost abutting against the base of the pin 8”. In figure 48, it is indeed possible to observe that the lower end 96”b of the magnetic element 96” is in proximity of the base of the pin 8” and in a position distant from the lower end 95”a of the ferromagnetic element 95”.

[0443] In figure 49, the drain 1” is instead shown with the overflow mechanism triggered. As described with reference to the second embodiment, when the overflow mechanism is triggered, the upper portion 7” and the covering element 5” stay stationary, i.e. they do not lower (it is indeed possible to observe that the first resilient element 39” is not contracted more than what is shown in figure 47).

[0444] Indeed, the pressure of the water column, which makes the overflow mechanism trigger once a preset threshold value is reached, is exerted on the shutter body 13”, at the upper surface 92”a of the shutter body 13”.

[0445] Therefore, when the pressure threshold value is reached, the shutter body 13” moves to a lowered position (or to an intermediate position between the raised position and the lowered position) and, as described above, the lower end 96”b of the magnetic element 96” moves to a position distant from the ferromagnetic element 95”.

[0446] By comparing figures 48 and 49, it is possible to observe that, following the triggering of the overflow mechanism, the second resilient element 40” extends precisely because the upper portion and the insert 60” stay stationary. In this circumstance, the sum of the thrust force of the second resilient element 40” and the water column pressing on the shutter 6” exceeds the attractive force between the ferromagnetic element 95” and the magnetic element 96”, until they become equal.

[0447] When the water pressure returns below a threshold value, the attractive force between the ferromagnetic element 95” and the magnetic element 96” exceeds the sum of the thrust force of the second resilient element 40” and the water column pressing on the shutter 6” and, therefore, the shutter body 13” automatically moves to a raised position, thus closing the passage of water through the drain 1”.

[0448] As known, the thrust force of a resilient element is inversely proportional to its elongation; moreover, the Applicant found that the more the ferromagnetic element 95” and the magnetic element 96” are misaligned (i.e. the more the magnetic element 96” is displaced with respect to the ferromagnetic element 95” by bringing the latter to emerge from the magnetic element 96”), the more the magnetic element 96” is attracted by the ferromagnetic element 95”, to bring it back to an aligned situation.

[0449] The advantage of this embodiment lies in that the overall force exerted by the overflow mechanism, and which opposes the pressure of the water column pressing on the shutter 6”, is constant.

[0450] This ensures that, when the overflow mechanism is triggered, the lowering of the shutter body 13” has a constant trend and is not greater (or less) at the beginning of the travel and less (or greater) at the end of the travel.

[0451] As described with reference to the second embodiment, in order to calibrate the overflow mechanism, it is possible to replace the insert 60” with a different insert (not shown) of a different length.

[0452] Unlike what is described in the second embodiment, inserting an insert longer than the insert 60” results in a lowering of the water pressure threshold value at which the overflow mechanism is triggered, whereas inserting an insert shorter than the insert 60” results in an increase of the water pressure threshold value at which the overflow mechanism is triggered.

[0453] With reference to figures 50, 51 , 52, a fourth embodiment of a drain according to the present invention is described and denoted by the reference number T”.

[0454] In particular, figures 50-52 show an elevation and sectional view of the drain T” with respect to a sectional plane containing the longitudinal axis X’” (shown in figure 50). The drain T” is closed in figure 50, the drain T” is open in response to the triggering of the click-clack mechanism in figure 51 and the drain T” is open in response to the triggering of the overflow mechanism in figure 52.

[0455] The drain T” can be seen as a variant of the drain T and is similar to the drain 1” as far as the making of the click-clack mechanism and its general features (features of the body 2”’ of the drain, of the covering element 5”’, etc.) are concerned. What is set forth above with regard to these points can thus also be extended to this embodiment.

[0456] The drain T” comprises a shutter 6”’ which has an upper portion 7”’: the covering element 5”’ is screwed onto the shutter at the upper portion 7”’ and the manual calibration means of the overflow mechanism, i.e. of the insert 60”’, are arranged on the upper portion 7”’.

[0457] The shutter 6”’ further comprises a lower portion 9”’ at which the body 2”’ of the drain is fastened.

[0458] The shutter 6”’ comprises a shutter body 13” similar to the one described in the third embodiment.

[0459] The shutter body 13”’ is movable between a raised position corresponding to the drain T” closed (see figure 50) and a lowered position corresponding to the drain T” open (see figure 51 ).

[0460] The shutter body 13’” extends along the longitudinal axis X’” and comprises a circular and hollow tubular element 26’” (cavity 93’”). The tubular element 26’” seals the cavity 93’”.

[0461] The tubular element 26’” extends between an upper end 26”’a and a lower end 26”’b: the cavity 93’” defined by the stem extends between these two ends of the tubular element 26’”.

[0462] The shutter body 13’” has a central portion 92’” intended for closing the passage of water in the drain T” and from which the tubular element 26’” extends downward.

[0463] The shutter 6” further comprises a bellows-shaped element 90’” positioned below the central portion 92’”.

[0464] The central portion 92’” has an upper surface 92”’a opposite the tubular element 26’”. At the upper surface 92”’a, the shutter body 13’” has a pin 27’”, i.e. a pin-shaped portion, extending upward.

[0465] The pin 27’” is hollow, i.e. has a cavity 94’” in which a resilient element 40’” is positioned, identified as second resilient element 40”.

[0466] It is indeed possible to notice that the shutter 6’” has a first resilient element 39’” at the upper portion 7’” which is part of the click-clack mechanism. In practice, the second resilient element 40”’ is arranged between the insert 60”’ and the central portion 92’” and is one of the components of the overflow mechanism. The second resilient element 40’” is preloaded and mounted in the shutter 6’” (as can be seen in figure 50).

[0467] The shutter 6’” has, at its lower portion 9’”, a chamber 10T” which is mounted on the body 2’” of the drain and which delimits a cavity 97’”; the chamber 10T” defines an opening 98’” on its top.

[0468] The shutter body 13’” is fit on the chamber 10T” with its tubular element 26’” and is supported by a resilient element identified as third resilient element 99’” and preferably made of harmonic steel.

[0469] The third resilient element is preferably made as an elastic harmonic steel lever. The third resilient element 99’” is fastened to a pin 8’” of the body 2’” of the shutter T”.

[0470] The shutter 6’” further comprises a plunger 100’” which is fit on the pin 8’” and has an upper end 100”’a and a lower end 100”’b. The shutter body 13” is supported by the third resilient element 99’” by means of the plunger 100’” which is thus interposed between the shutter body 13’” and the third resilient element 99’”.

[0471] The plunger 100’” is mounted to be floating on the pin 8’”, i.e. is susceptible of movements from a raised position, shown in figure 50, and a lowered position, shown in figure 51 .

[0472] It is indeed possible to observe that when the plunger 100’” is in the lowered position, the lower end 100”’b is in a position proximal to the body 2” of the drain.

[0473] The third resilient element 99’” is movable between a first extended configuration (shown in figure 50) and a contracted configuration (shown in figure 51 ).

[0474] When the third resilient element 99’” is in the extended configuration, it exerts a minimum or null upward force, i.e. away from the pin 8’”, on the shutter body 13’”; instead, when the third resilient element 99” is in a contracted configuration, it exerts an upward thrust force on the shutter body 13”’, aimed at bringing back the shutter body 13”’ from the lowered position to the raised position.

[0475] As shown in figure 50, when the drain T” is closed, the shutter body 13’” is in a raised position and closes the passage of water through the drain by abutting with the gasket 11’” on the body 2” of the drain 1”. In this circumstance, the third resilient element 99’” is in an extended configuration.

[0476] When a user exerts a downward thrust on the covering element 5’” to open the drain T”, by activating the click-clack mechanism, he / she causes the shutter body 13’” to be lowered, as shown in figure 51 .

[0477] As described with reference to the second embodiment and the third embodiment, since the click-clack mechanism was triggered, the upper portion 7’” moves to a lowered position and the third resilient element 99’” is compressed, i.e. is in a compressed configuration.

[0478] In figure 52, the drain T” is instead shown with the overflow mechanism triggered.

[0479] As described with reference to the second and the third embodiments, when the overflow mechanism is triggered, the upper portion 7’” and the covering element 5’” stay stationary, i.e. they do not lower (it is indeed possible to observe that the first resilient element 39’” is not contracted more than what is shown in figure 50).

[0480] Indeed, the pressure of the water column, which makes the overflow mechanism trigger once a preset threshold value is reached, is exerted on the shutter body 13’”, at the upper surface 92”’a of the shutter body 13’”.

[0481] Therefore, when the pressure threshold value is reached, the shutter body 13’” moves to a lowered position (or an intermediate position between the raised position and the lowered position) and the third resilient element 99’” moves to a contracted configuration.

[0482] By comparing figures 51 and 52, it is possible to observe that, following the triggering of the overflow mechanism, the second resilient element 40’” extends precisely because the upper portion 7”’ and the insert 60” stay stationary. In this circumstance, the sum of the thrust force of the second resilient element 40”’ and the water column pressing on the shutter 6”’ exceeds the thrust force of the third resilient element 99”’, until they become equal.

[0483] When the water pressure returns below a threshold value, the thrust operated by the third resilient element 99’” exceeds the sum of the thrust force of the second resilient element 40’” and the water column pressing on the shutter 6’” and, therefore, the shutter body 13’” automatically moves to a raised position, thus closing the passage of water through the drain T”.

[0484] As described for the third embodiment, the advantage of the drain T” lies in the fact that the overall force exerted by the overflow mechanism, and which opposes the pressure of the water column pressing on the shutter 6”, is constant.

[0485] When the overflow mechanism is triggered, the lowering of the shutter body 13” thus has constant trend and is not greater (or less) at the beginning of the travel and less (or greater) at the end of the travel.

[0486] As described with reference to the third embodiment, in order to calibrate the overflow mechanism, it is possible to replace the insert 60’” with a different insert (not shown) of a different length. What is described above with reference to the third embodiment can thus also be extended to this embodiment.

[0487] A field technician can combine one another one or more of the characteristics described above with reference to the first, second, third or fourth embodiment.

[0488] In order to meet contingent and specific requirements, several variations and modifications could be made by a field technician to the illustrated and described embodiments of present invention, provided that all are included in the protection scope of the invention as defined by the following claims.

Claims

CLAIMS1. A drain (1 , T, 1”, 1”’) for sanitary fixtures comprising:- a body (2, 2a, 2b, 2’, 2”, 2”’) of the drain extending along a longitudinal axis (X, X’, X”, X’”);- a shutter (6, 6’, 6”, 6”’) housed in the body (2, 2a, 2b, 2’, 2”, 2”’) of the drain and comprising a shutter body (13, 13’, 13”, 13”’) which is movable along said longitudinal axis (X, X’, X”, X’”) with respect to said body (2, 2a, 2b, 2’, 2”, 2’”) of the drain between a raised position, corresponding to said drain (1 , T, 1”, T”) closed, and a lowered position, corresponding to said drain (1 , T, 1”, T”) completely open;- a covering element (5, 5’, 5”, 5’”) coupled to said shutter (6, 6’, 6”, 6’”) at an upper portion (7, 7’, 7”, 7”) of the shutter (6, 6’, 6”, 6’”);- a click-clack mechanism for the snap opening and closing of the drain (1 , T, 1”, T”), arranged in the shutter (6, 6’, 6”, 6’”) to bring said shutter body (13, 13’, 13”, 13’”) from the raised position to the lowered position, or vice- versa, in response to a force applied manually by the user on the shutter (6, 6’, 6”, 6’”) along the longitudinal axis (X, X’, X”, X’”) and always directed in the same direction;- an overflow mechanism arranged in the shutter (6, 6’, 6”, 6’”) to be automatically triggered and to bring said shutter body (13, 13’, 13”, 13’”) to the lowered position, or to an intermediate position between the raised position and the lowered position, in response to reaching a threshold value of the pressure exerted on the shutter (6, 6’, 6”, 6’”) by the water column which, during use, presses on said shutter (6, 6’, 6”, 6’”) or said covering element (5, 5’, 5”, 5’”);- manual calibration means (60; 60’, 60”, 60’”) of the overflow mechanism, characterized in that said manual calibration means (60; 60’, 60”, 60’”) of the overflow mechanism are arranged on said upper portion (7, 7’, 7”, 7’”) of the shutter (6, 6’, 6”, 6’”).

2. Drain (1 , T, 1”, 1’”) according to claim 1 , wherein said manualcalibration means (60; 60’, 60”, 60”’) are triggered by a user to calibrate the overflow mechanism, said shutter (6, 6’, 6”, 6’”) being assembled, and not disassembled, and combined with said body (2, 2a, 2b, 2’, 2”, 2’”) of the drain.

3. Drain (1 , T, 1”, T”) according to claim 1 or 2, said drain being able to be configured in two states: a first state corresponding to the covering element (5, 5’, 5”, 5’”) coupled to the shutter (6, 6’, 6”, 6’”) and to said manual calibration means (60; 60’, 60”, 60’”) covered by the covering element (5, 5’, 5”, 5’”) and inaccessible to the user, and a second state corresponding to said covering element (5, 5’, 5”, 5’”) separated from said shutter (6, 6’, 6”, 6’”) and to said manual calibration means (60; 60’, 60”, 60’”) not covered by said covering element (5, 5’, 5”, 5’”) and accessible to the user, wherein said pressure threshold value, which triggers the overflow mechanism, cannot be changed in the first state and wherein said pressure threshold value can be changed manually by the user in the second state, by acting on the manual calibration means (60; 60’, 60”, 60’”) of the overflow mechanism.

4. Drain (1 , T, 1”, T”) according to claims 1 to 3, wherein said upper portion (7, 7’, 7”, 7’”) of the shutter (6, 6’, 6”, 6’”) has an upper surface (48, 48’) and wherein said manual calibration means (60; 60’, 60”, 60’”) are arranged on, or are facing, said upper surface (48, 48’) of the shutter (6, 6’, 6”, 6’”).

5. Drain (1 , T, 1”, T”) according to claim 4, wherein said shutter (6, 6’, 6”, 6’”) comprises a lower portion (9, 9’, 9”, 9’”) opposite said upper portion (7, 7’, 7”, 7’”) at which said shutter (6, 6’, 6”, 6’”) is combined with said body (2, 2a, 2b, 2’, 2”, 2””) of the drain, wherein said upper portion (7, 7’, 7”, 7’”) of the shutter (6, 6’, 6”, 6’”) comprises coupling means at which said covering element (5, 5’, 5”, 5’”) is coupled to said shutter (6, 6’, 6”, 6’”), wherein, considering said longitudinal axis (X, X’, X”, X’”), said coupling means extend between said upper surface (48, 48’) and said lower surface (9, 9’, 9”, 9’”) of the shutter (6, 6’,6”, 6”’).

6. Drain (1 ) according to claim 5, wherein said manual calibration means (60) are movable manually by a user with respect to said lower portion (9) between a first position, which is distal with respect to said lower portion (9), and a second position which is proximal to said lower portion (9), and vice- versa, wherein said first position corresponds to a first pressure threshold value and said second position corresponds to a second pressure threshold value different from the first threshold value.

7. Drain (1 ) according to claim 6, wherein a hole (47) is formed in said upper surface (48), wherein said manual calibration means (60) are inserted into said hole (47) and rotatable by a user in said hole (47) with respect to said lower portion (9) in a first direction and in a second direction opposite the first, and vice-versa, and wherein said manual calibration means (60) are movable: from said first position to said second position, or to an intermediate position between said first position and said second position, in response to a rotation imparted by a user to said manual calibration means (60) in said first direction, and from said second position, or from an intermediate position between said first position and said second position, to said first position in response to a rotation imparted by a user to said manual calibration means (60) in said second direction.

8. Drain (1 ) according to claim 6 or 7, wherein said manual calibration means (60) have an upper surface (62) into which a blind hole (63) is formed, said blind hole (63) being adapted for being engaged by a tool controlled manually by a user for moving said manual calibration means (60) between said first position and said second position.

9. Drain (1 ) according to any one of preceding claims 5-8, wherein the manual calibration means (60) are configured as a threaded insert inserted into a corresponding threaded hole (47) formed in said upper portion (7) of the shutter, said threaded hole (47) extending along said longitudinal axis (X), saidinsert being screwable and unscrewable into / from said threaded hole (47) in response to a rotation imparted by a user to the insert in a first direction and in a second direction opposite the first direction by means of a tool.

10. Drain (1 ) according to any one of preceding claims 5-9, wherein said lower portion comprises a rod-shaped element (24) and said upper portion comprises a plug (41 ), wherein said rod-shaped element (24) in turn comprises a stem (26) at which the shutter (6) is coupled to said body (2) of the drain (1 ), wherein said plug (41) closes said rod-shaped element (24) on the opposite side with respect to said stem (26), wherein said plug (41 ) is integrally movable with the shutter body along the longitudinal axis (X) with respect to said rodshaped element (24):- between a raised position with respect to said rod-shaped element (24), corresponding to the drain (1 ) closed, and a position lowered onto said rodshaped element (24), corresponding to the drain (1 ) open, and vice-versa, in response to the triggering of the click-clack mechanism, or- from said raised position, with respect to said rod-shaped element (24), to said lowered position or to an intermediate position between said raised position and said lowered position, and vice-versa, in response to the triggering of the overflow mechanism.

11. Drain (1 ) according to claim 10, wherein said manual calibration means (60) are inserted into the plug (41 ) on the side opposite said rod-shaped element and are movable manually by a user to adjust the calibration of the overflow mechanism from a first distal position with respect to said rod-shaped element (24) to a second proximal position with respect to said rod-shaped element (24), and vice-versa, wherein said first position corresponds to a first pressure threshold value and said second position corresponds to a second pressure threshold value different from the first threshold value.

12. Drain (1 ) according to claim 11 , wherein said shutter (6) comprises a resilient element of the overflow mechanism, identified as second resilient element (40), which resilient element is housed at least partially in the shutterbody and is interposed between said manual calibration means (60) and said stem, wherein said shutter (6) is configurable manually by a user in at least one first configuration and in a second configuration in response to the displacement of said manual calibration means (60), respectively, between said first distal position and said second proximal position, wherein, in said second configuration of the shutter (6), said second resilient element (40) is in a configuration more compressed than the same second resilient element (40) in said first configuration, and said second pressure threshold value is greater than said first pressure threshold value.

13. Drain (1 ) according to claims 10 or 11 , wherein said shutter (6) comprises a ring (22) fit on said rod-shaped element (24) and rotatable about the longitudinal axis (X) with respect to said rod-shaped element (24) in response to a pressure exerted by a user on said plug (41 ) along said longitudinal axis (X) and still directed towards said rod-shaped element (24), wherein said shutter (6) comprises a resilient element of the click-clack mechanism and identified as first resilient element (39), the resilient element being arranged for being compressed when said plug (41 ) lowers onto said rodshaped element (24) and for extending, thus bringing back said plug (41 ) to the raised position, wherein said ring (22) comprises at least one protrusion (23), or a tooth, which engages a corresponding profile, or circuit (30), provided in the plug (41 ) or on the rod-shaped element (24), wherein said profile, or circuit (30), has at least one upper seat (32) and at least one lower seat (36), and wherein: said protrusion (23) engaged in said at least one upper seat (23) corresponds to said plug (41 ) raised with respect to said rod-shaped element (24) and to the drain (1 ) closed, and said protrusion (23) engaged in said at least one lower seat (36) corresponds to said plug (41 ) lowered onto said rod-shaped element (24) and to the drain (1 ) open.

14. Drain (T, 1”, 1”’) according to any one of preceding claims 1-5,wherein said shutter (6’, 6”, 6”’) has a lower portion (9’, 9”, 9”’) at which said shutter (6’, 6”, 6”’) is combined with said body (2’, 2”, 2”’) of the drain, wherein said manual calibration means (60’, 60”, 60”’) of the overflow mechanism are reversibly coupled to said shutter (6’, 6”, 6’”) at said lower portion (7’, 7”, 7’”), said manual calibration means (60’, 60”, 60’”) preferably being adapted for being replaced with different manual calibration means, i.e. with manual calibration means of the overflow mechanism which are different from said manual calibration means (60’, 60”, 60’”), for calibrating the overflow mechanism.

15. Drain (T, 1”, 1’”) according to said claim 14, wherein said manual calibration means (60’, 60”, 60’”) are configured as an insert and have an upper surface (62) into which a blind hole (63’) is formed, said blind hole (63') being adapted for being engaged by a tool controlled manually by a user for separating said manual calibration means (60’, 60”, 60’”) from said upper portion (7’, 7”, 7’”).

16. Drain (T, 1”, 1’”) according to claims 14 or 15, wherein said upper portion (7’, 7”, 7’”) comprises a supporting element (87’), which is arranged for supporting said covering element (5’, 5”, 5’”), and a plug (41’), wherein said plug (41’) is made in one piece with said shutter body (13’, 13”, 13’”) and is integral with said shutter body (13’, 13”, 13’”), wherein said supporting element (87’) is arranged axially between said covering element (5’, 5”, 5’”) and said lower portion (9’, 9”, 9’”) and wherein said manual calibration means (60’, 60”, 60’”) are coupled to said plug (41’) or to said shutter body (13’, 13”, 13’”) at said supporting element (87’).

17. Drain (T, 1”, 1’”) according to claim 16, wherein said supporting element (87’) defines a through hole (88’) and wherein said manual calibration means (60’, 60”, 60’”) can be inserted into and removed from said plug (41’) or from said shutter body (13’, 13”, 13’”) through said through hole (88’).

18. Drain (T, 1”, 1’”) according to preceding claims 16 or 17, wherein:- said click-clack mechanism is arranged for being triggered in responseto a force exerted by a user at said covering element (5’, 5”, 5”’) or said upper portion (7’, 7”, 7”’) and always directed towards the lower portion (9’, 9”, 9”’);- said overflow mechanism is arranged for being automatically triggered in response to reaching a threshold value of the pressure exerted on the shutter (6’, 6”, 6”’) by the water column, which, during use, presses on said shutter plug (41’) or said shutter body (13’, 13”, 13’”), wherein said upper portion (7’, 7”, 7’”) stays stationary with respect to said body (2’, 2”, 2’”) of the drain in response to the triggering of the overflow mechanism.

19. Drain (T, 1”, 1’”) according to claims 14-18, wherein, at said upper portion (7’, 7”, 7’”), said shutter (6’, 6”, 6’”) comprises a flange (80’) and a bearing (86’) inserted into said flange (80’), said bearing (86’) being rotatable on said longitudinal axis (X’, X”, X’”) with respect to said flange (80’) in response to a pressure exerted by a user on said upper portion (7’, 7”, 7’”) along said longitudinal axis (X’, X”, X’”), always directed downward, wherein said shutter (6’, 6”, 6’”) comprises a resilient element of the click-clack mechanism, identified as first resilient element (39’), which resilient element is arranged for being compressed when lowering said upper portion (7’, 7”, 7’”) and for extending, thus bringing back said upper portion (7’, 7”, 7’”) to said raised position, wherein said bearing (86’) comprises at least one protrusion (85’), or a tooth, which engages a corresponding profile (84’) provided in the flange, wherein said profile (84’) has at least one upper seat and at least one lower seat, and wherein:- said protrusion (85’) engaged in said at least one upper seat corresponds to said upper portion (7’, 7”, 7’”) raised and to said drain (T, 1”, T”) closed, and- said protrusion (85’) engaged in said at least one lower seat corresponds to said upper portion (7’, 7”, 7’”) lowered and to the drain (T, 1”, T”) open.

20. Drain (T) according to claims 14-19, wherein said lower portion (9’,9”, 9”’) comprises a rod-shaped element (24’) at which the shutter (6’) is coupled to said body (2’) of the drain, wherein said shutter (6’) comprises a resilient element of the overflow mechanism, identified as second resilient element (40’), housed at least partially in said rod-shaped element (24’) and which resilient element is functionally interposed between said manual calibration means (60’) and said rod-shaped element (24’).

21. Drain (T) according to claim 20, wherein said manual calibration means (60’) extend along said longitudinal axis (X’) for a first length, wherein said manual calibration means (60’) are separable from said upper portion (7’) of the shutter (6’) and are adapted for being replaced with different manual calibration means, i.e. different from said manual calibration means (60’), said different manual calibration means extending for a length greater or less than said first length, wherein said shutter (6’) is manually configurable by a user in at least one first configuration corresponding to said manual calibration means (60’) inserted into said shutter (6’) and in a second configuration corresponding to said manual calibration means (60’) separated from said shutter and to said different manual calibration means inserted into said shutter (6’) in response to a replacement by a user of said manual calibration means (60’) with said different manual calibration means, wherein, in said second configuration of the shutter (6’), said second resilient element (40’) is in a configuration more compressed or less compressed, respectively, than the same second resilient element (40’) in said first configuration and said second pressure threshold value is greater or less, respectively, than said first pressure threshold value.

22. Drain (1”) according to claims 14-19, wherein said drain comprises a ferromagnetic element (95”) integral with the body (2”) of the drain and extending along said longitudinal axis (X”), wherein said shutter (6”) comprises a magnetic element, identified as third magnetic element (96”), which magnetic element is integral with the shutter body (13”) and coaxial with respect to said ferromagnetic element (95”), said third magnetic element (96”) being susceptible to displacements with respect to said ferromagnetic element (95”),wherein the shutter body (13”) is movable with respect to said ferromagnetic element (95”) from said raised position, corresponding to said third magnetic element (96”) aligned with said ferromagnetic element, to said lowered position or to an intermediate position between said raised position and said lowered position, corresponding to said third magnetic element (96”) misaligned with respect to said ferromagnetic element (95”) and said ferromagnetic element (95”) protruding upward with respect to said third magnetic element (96”), in response to the triggering of the overflow mechanism, wherein said third magnetic element (96”) misaligned with respect to said ferromagnetic element (95”) results in an attractive force which tends to bring the shutter body (13”) to a raised position.

23. Drain (T”) according to claims 14-19, wherein said shutter body (13”’) is supported on said body (2”’) of the drain by means of a resilient element, identified as third resilient element (99”’) and preferably configured as a harmonic steel lever, wherein said third resilient element (99’”) is configurable in a first extended configuration and a second contracted configuration, wherein the shutter body (13’”) is movable from said raised position to said lowered position or to an intermediate position between said raised position and said lowered position, and vice-versa, in response to the triggering of the overflow mechanism, wherein said shutter body (13’”) in raised position corresponds to said third resilient element (99’”) in extended configuration and said shutter body (13’”) in lowered position corresponds to said third resilient element (99’”) in contracted configuration, wherein said third resilient element in contracted configuration exerts a thrust on said shutter body (13’”) which tends to bring said shutter body (13’”) to a raised position.

24. Drain (1”, T”) according to claim 22 or 23, wherein said shutter (6”, 6’”) comprises a resilient element of the overflow mechanism, identified as second resilient element (40”, 40’”), which resilient element is housed in said shutter body (13”, 13’”) and interposed between said shutter body (13”, 13’”) and said manual calibration means (60”, 60’”), wherein said manual calibrationmeans (60”, 60”’) extend along said longitudinal axis (X”, X’”) for a first length, wherein said manual calibration means (60”, 60”’) are separable from said upper portion (7”, 7’”) of the shutter and are adapted for being replaced with different manual calibration means, i.e. different from said manual calibration means (60”, 60’”), said different manual calibration means extending for a length greater or less than said first length, wherein said shutter (6”, 6’”) is manually configurable by a user in at least one first configuration corresponding to said manual calibration means (60”, 60’”) inserted into said shutter and in a second configuration corresponding to said manual calibration means (60”, 60’”) separated from said shutter (1”, T”) and to said different manual calibration means inserted into said shutter (6”, 6’”) in response to a replacement by a user of said manual calibration means (60”, 60’”) with said different manual calibration means, wherein, in said second configuration of the shutter (6”, 6’”), said second resilient element (40”, 40’”) is in a configuration more compressed or less compressed, respectively, than the same second resilient element (40”, 40’”) in said first configuration and said second pressure threshold value is less or greater than, respectively, said first pressure threshold value.

25. Method of calibrating the overflow mechanism of a drain (1 , T, 1”, T”) installed in a sanitary fixture, comprising the steps of: a) providing a drain (1 , T, 1”, T”) according to any one of preceding claims 1-24, installed in a sanitary fixture; b) separating said covering element (5, 5’, 5”, 5’”) from said upper portion (7, 7’, 7”, 7’”) of the shutter (6, 6’, 6”, 6’”); c) manually calibrating the overflow mechanism by acting on said manual calibration means (60, 60’, 60”, 60””) arranged on said upper portion (7, 7”, 7”, 7’”) of the shutter (6, 6’, 6”, 6’”); d) coupling said covering element (5, 5’, 5”, 5’”) to said upper portion (7, 7’, 7”, 7’”) of the shutter (6, 6’, 6”, 6’”), wherein in step c), said drain (1 , T, 1”, T”) stays installed in the sanitaryfixture and the shutter (6, 6’, 6”, 6”’) stays housed in the drain body (2, 2’, 2”, 2”’).

26. Method according to claim 25, wherein said manual calibration means (60) are inserted into said shutter (6) and are rotatable with respect to said shutter (6) in a first direction and a second direction opposite the first, and vice-versa, for calibrating said overflow mechanism, wherein, in step c), the calibration of the overflow mechanism is performed manually by a user by rotating said manual calibration means (60) in said first direction or said second direction at said upper portion (7) and by keeping said manual calibration means (60) inserted into said shutter (6).

27. Method according to claim 25, wherein said manual calibration means (60’, 60”, 60”’) are inserted into said shutter (6’, 6”, 6’”) and extend along said longitudinal axis (X’, X”, X’”) for a first length and wherein said manual calibration means (60’, 60”, 60’”) are separable from said shutter (6’, 6”, 6’”), said manual calibration means (60’, 60”, 60’”) being adapted for being replaced with different manual calibration means, i.e. different from said manual calibration means (60’, 60”, 60’”), said different manual calibration means extending for a length greater or less than said first length, wherein, in step c), the calibration of the overflow mechanism is performed manually by a user by removing said manual calibration means (60’, 60”, 60’”) from said shutter (6’, 6”, 6’”) at said upper portion (7’, 7”, 7’”) and by inserting said different manual calibration means into said shutter (6’, 6”, 6’”) at said upper portion (7’, 7”, 7’”) .

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