* * *

The present invention relates to a mechanical coupling assembly, in particular a hydraulic coupling assembly, between two components the inner parts of which communicate with each other, the mechanical coupling assembly allowing in a simple, reliable, efficient and inexpensive way to ensure the seal, in particular with respect to dusts and liquids, compensating the surface irregularities of the opposing walls of the coupled components and further permitting a simple assembling of the components. In particular, when the mechanical coupling assembly is a hydraulic coupling assembly, between two hydraulic components wherein a fluid, optionally water, passes from one component to the other, the mechanical coupling assembly allows to ensure the hydraulic seal with both fluid in static conditions and moving flow under several operation conditions.

In the following of the present description, reference will be mainly made to an application of the mechanical coupling assembly according to the invention to a modular probe-holder configured to house sensing probes for sensing physico-chemical parameters of a fluid, optionally water, applicable for instance to the water treatment. However, it must understood that the mechanical coupling assembly according to the invention may be used in any other mechanical application still remaining within the scope of protection of the present invention as defined in the attached claims; by way of example, the mechanical coupling assembly may be applied for coupling two hydraulic components to each other so that a fluid, optionally water, flows from one component to the other, or it may be applied for coupling due components of an electrical box so as to seal the inside of the electrical box against dusts, fumes and liquids (e.g. rainwater).

It is known that in water treatment it is essential to sense physico-chemical parameters of the same water, such as for instance the volumetric flow rate, the pH value or the content of possibly dissolved specific substances (e.g., chlorine). To this end, sensing probes are used which are arranged along a sensing path in which water that is to undergo sensing at least partially flows. In particular, such sensing probes are housed in a dedicated compartment of a monolithic probe-holder, usually of plastic material, provided with an inlet and an outlet, that is part of such sensing path.

A specific application requires a peculiar arrangement of sensing probes, whereby it is necessary to make a corresponding specific probe-holder for each specific application, with consequent high manufacturing costs. Moreover, in the case where an upgrade of an existing arrangement of sensing probes is required, it is necessary to make a new probe-holder.

In order to render a probe-holder, configured to house sensing probes for monitoring and/or controlling the quality of water, and more generally of a fluid, scalable in size and upgradeable in functionalities, the inventors have developed a modular probe-holder composed of two or more probe-holding modules, optionally of type different from each other, made of a transparent plastic material, optionally poly(methyl methacrylate) (also known with the acronym PMMA), which are coupled to each other. The probe-holding modules of the modular probe-holder are configured to house sensing probes for sensing physico-chemical parameters of a fluid, optionally water.

The pairs of probe-holding modules coupled to each other are hydraulic components having two respective opposing apertures which communicate for allowing the fluid to pass from one component to the other.

In order to guarantee the seal of such hydraulic coupling, the prior art solutions comprise at least one O-ring seal of elastic material that is housed in a corresponding seat, for instance a groove, that surrounds the two opposing apertures, as illustrated by the known "Parker O-ring Handbook 2001-Edition", available from the Parker Hannifin Corporation, Cleveland, Ohio, USA, and as discloses for instance by documents FR 2610382 Al, US 6173968 Bl and EP 2284423 Al.

However, the prior art solutions suffer from some drawbacks.

First of all, they do not easily adapt to possible surface irregularities of the opposing walls of the coupled components.

Moreover, they are rather complex from both a constructive and functional point of view, consequently entailing high costs of manufacture, assembly and maintenance.

It is an object of this invention, therefore, to allow in a simple, reliable, efficient and inexpensive way to ensure the seal of two mechanical components, in particular hydraulic components, coupled to each other (for instance such that the inner parts of which communicate with each other), compensating the surface irregularities of the opposing walls of the coupled components and further permitting a simple assembling of the same components.

It is another object of this invention to ensure the hydraulic seal of two coupled hydraulic components wherein a fluid, optionally water, passes from one component to the other, with both fluid in static conditions and moving flow under several operation conditions.

It is specific subject-matter of the present invention a mechanical coupling assembly comprising a first component having a first wall, and a second component having a second wall, wherein the first wall of the first component is coupled to the second wall of the second component, at least one elastic seal being inserted into at least one corresponding seal groove, with which one from the first wall of the first component and the second wall of the second component is provided, whereby said at least one elastic seal seals the coupling of the first wall of the first component with the second wall of the second component, the mechanical coupling assembly being characterised in that said at least one elastic seal has circular cross- section having diameter w and said at least one corresponding seal groove has rectangular cross-section, with width w equal to the diameter w and depth p lower than the diameter w.

According to another aspect of the invention, the depth p of said rectangular cross- section of said at least one corresponding seal groove may be not larger than 95% of the diameter w of said circular cross-section of said at least one elastic seal, optionally not larger than 85% of the diameter w of said circular cross-section of said at least one elastic seal, more optionally not larger than 80% of the diameter w of said circular cross-section of said at least one elastic seal, still more optionally ranging from 65% to 75% of the diameter w of said circular cross-section of said at least one elastic seal, even more optionally equal to 70% of the diameter w of said circular cross-section of said at least one elastic seal.

According to a further aspect of the invention, said at least one elastic seal may be made of fluoroelastomer.

According to an additional aspect of the invention, said at least one elastic seal may have a hardness not lower than 50 shore A (SHA).

According to another aspect of the invention, said hardness of said at least one elastic seal may be not lower than 60 SHA.

According to a further aspect of the invention, the first wall of the first component and the second wall of the second component may be planar.

According to an additional aspect of the invention, the first component may be a hydraulic component including an outlet arranged on the first wall, and the second component may be a hydraulic component including an inlet arranged on the second wall, whereby the first wall of the first component is coupled to the second wall of the second component so that the outlet of the first component communicates with the inlet of the second component, the first component and the second component being configured to receive a flow of a fluid flowing from the outlet of the first component to the inlet of the second component, said at least one corresponding seal groove being arranged for surrounding the outlet of the first component and the inlet of the second component.

It is further specific subject-matter of the present invention a component, having at least one wall, for use in the mechanical coupling assembly previously described, at least one elastic seal being inserted into at least one corresponding seal groove, with which the component is provided on said at least one wall, the component being characterised in that said at least one elastic seal has circular cross-section having diameter w and said at least one corresponding seal groove has rectangular cross-section, with width w equal to the diameter w and depth p lower than the diameter w.

According to another aspect of the invention, the depth p of said rectangular cross- section of said at least one corresponding seal groove may be not larger than 95% of the diameter w of said circular cross-section of said at least one elastic seal, optionally not larger than 85% of the diameter w of said circular cross-section of said at least one elastic seal, more optionally not larger than 80% of the diameter w of said circular cross-section of said at least one elastic seal, still more optionally ranging from 65% to 75% of the diameter w of said circular cross-section of said at least one elastic seal, even more optionally equal to 70% of the diameter w of said circular cross-section of said at least one elastic seal.

According to a further aspect of the invention, said at least one elastic seal may be made of fluoroelastomer.

According to an additional aspect of the invention, said at least one elastic seal may have a hardness not lower than 50 shore A (SHA), optionally not lower than 60 SHA.

According to another aspect of the invention, said at least one wall may be planar. According to a further aspect of the invention, the component may include at least one aperture arranged on said at least one wall, said at least one aperture being configured to allow a fluid to flow through said at least one aperture, said at least one corresponding seal groove being arranged for surrounding said at least one aperture. In other words, said at least one aperture is configured to operate as inlet of the component, operating as hydraulic component, configured to receive a flow of a fluid, or as outlet of the component, still operating as hydraulic component, configured to emit a flow of a fluid.

The advantages offered by the mechanical coupling assembly according to the invention are evident.

First of all, the geometric and size features of the mechanical coupling assembly according to the invention compensate the surface irregularities of the opposing walls of the two coupled components, in particular hydraulic components, allowing a higher tolerance for size of the components and for the characteristics of the contacting surfaces (e.g. surface planarity and roughness) still ensuring the seal of the mechanical coupling. In particular, the pressure on the seal (that must be closed, in the sense that it follows a closed curve) may be exerted from both the outside or the inside ensuring the seal (whereby an area internal to the closed curve defined by the seal is not communicating with an area external to the closed curve defined by the seal). In the case where the mechanical coupling assembly according to the invention is applied for sealing electrical boxes against dusts, fumes and liquids (e.g. rainwater), it is possible to obtain high values of IP - international standard "Ingress Protection Rating" for seals -, generally at least equal to IP65 (i.e. total protection against dusts and protection against low pressure jets of water from all directions with a limited ingress); in the case where the mechanical coupling assembly according to the invention is applied to two coupled hydraulic components wherein a fluid, optionally water, passes from one component to the other, the mechanical coupling assembly allows to obtain a high seal with both fluid in static conditions and moving flow under several operation conditions, for instance guaranteeing performance up to a fluid pressure equal to 7 bar (where 1 bar = 10 ⁵ Pascal) and up to a temperature of 70°C. In particular, the opposing walls of the coupled components (each one of which may be only a portion of a surface structure) are not necessarily planar, being allowed to have any shape provided that the walls have corresponding shapes.

Moreover, even when the single components, in particular hydraulic components, provided with said (at least one) seal housed in said corresponding (at least one) groove are disassembled, the seal stably remains in the groove even if the module is moved.

Furthermore, the mechanical coupling assembly according to the invention is simple from both a constructive and functional point of view, consequently entailing reduced costs of manufacture, assembly and maintenance.

The present invention will be now described, by way of illustration and not by way of limitation, according to its preferred embodiments, by particularly referring to the Figures of the annexed drawings, in which:

Figure 1 shows a right side view of a first type of probe-holding module (Fig. la), a front view of a second type of probe-holding module (Fig. lb), a front view of a third type of probe- holding module (Fig. lc), a front view of a fourth type of probe-holding module (Fig. Id), and a front view of a fifth type of probe-holding module (Fig. le) of a modular probe-holder to which the preferred embodiment of the mechanical coupling assembly according to the invention is applied;

Figure 2 shows a front perspective view of the first type of probe-holding module (Fig. 2a) and a rear perspective view of the fifth type of probe-holding module (Fig. 2b) of Figure 1;

Figure 3 shows a front view (Fig. 3a) and a cross-section view along the plane AA of Figure 3a (Fig. 3b) of a first assembly of four of the probe-holding modules of Figure 1;

Figure 4 shows a first cross-section view (Fig. 4a) and a second cross-section view (Fig.

4b) of a particular of a coupling zone between two probe-holding modules of Figure 1, wherein each view represents specific features of the coupling;

Figure 5 shows a left side view of the fifth type of probe-holding module (Fig. 5a) of Figure 1 and a cross-section view (Fig. 5b) of a particular of a coupling zone of the preferred embodiment of the mechanical coupling assembly according to the invention applied to two probe-holding modules of Figure 1;

Figure 6 shows a front view (Fig. 6a) and a cross-section view along the plane BB of Figure 6a (Fig. 6b) of an assembly of four probe-holding modules of another modular probe- holder to which the preferred embodiment of the mechanical coupling assembly according to the invention is applied;

Figure 7 shows a cross-section view (Fig. 7a) of the first assembly of Figure 3 wherein each probe-holding module houses a respective sensing probe, an enlargement of the cross- section view (Fig. 7b) and a perspective view of a component coupled to the first assembly (Fig. 7c); and

Figure 8 shows a rear perspective view of a second assembly of two of the probe- holding modules of Figure 1 wherein each probe-holding module houses a respective sensing probe.

In the Figures identical reference numerals will be used for alike elements.

With reference to Figures 1 and 2, it may be observed that the preferred embodiment of the mechanical coupling assembly according to the invention is applied to a modular probe- holder that may be composed of two or more probe-holding modules coupled to each other the type of which is selected from a group comprising five types of different probe-holding modules, each one made in one piece of plexiglass that can be inscribed in a substantially parallelepiped-shaped polyhedron, and capable to be coupled to each other.

A first type of probe-holding module 100, shown in Figures la and 2a, is configured to house an adjustable flow meter, optionally capable to measure a volumetric flow rate ranging from 10 to 100 litres/hour. The first probe-holding module 100 comprises a longitudinal central duct (i.e., a vertical central duct) 110 that communicates externally through a lower threaded mouth 120, through an upper hollow threaded seat 125 and through an upper right side threaded outlet 130 ("right side" with respect to the front view of the first probe-holding module 100) connected to the longitudinal central duct 110 through an upper right transverse duct 135. Moreover, the first probe-holding module 100 is provided with an upper left side hollow seat 140 and a rear hollow seat 150.

A second type of probe-holding module 200, shown in Figure lb, is configured to house a sensing probe and comprises a longitudinal central duct 210 having a first diameter, optionally equal to 12 mm, that communicates externally through a lower threaded mouth 220, through an upper hollow threaded seat 225 and through an upper right side threaded outlet 230 ("right side" with respect to the front view of the second probe-holding module 200) connected to the longitudinal central duct 210 through an upper right transverse duct 235. Moreover, the second probe-holding module 200 is provided with a groove 260 on the left side wall that communicates with the longitudinal central duct 210 through a lower left transverse duct 265.

A third type of probe-holding module 300, shown in Figure lc, is configured to house a sensing probe and comprises a longitudinal central duct 310 having a second diameter larger than the first diameter, optionally equal to 24 mm, that communicates externally through a lower threaded mouth 320, through an upper hollow threaded seat 325 and through an upper right side threaded outlet 330 ("right side" with respect to the front view of the third probe- holding module 300). Moreover, the third probe-holding module 300 is provided with a groove 360 on the left side wall that communicates with the longitudinal central duct 310 through a lower left transverse duct 365.

A fourth type of probe-holding module 400, shown in Figure Id, is configured to house a sensing probe and comprises a longitudinal central duct 410 having a third diameter larger than the second diameter, optionally equal to 35 mm, that communicates externally through a lower threaded mouth 420, through an upper hollow threaded seat 425 and through an upper right side threaded outlet 430 ("right side" with respect to the front view of the fourth probe- holding module 400). Moreover, the fourth probe-holding module 400 is provided with a groove 460 on the left side wall that communicates with the longitudinal central duct 410 through a lower left transverse duct 465.

A fifth type of probe-holding module 500, shown in Figures le and 2b, is configured to house a horizontal amperometric sensor in a lower right side hollow seat 570 communicating inferiorly with a lower threaded mouth 520, in turn communicating externally, and superiorly with a longitudinal duct 510, in turn communicating externally through an upper hollow threaded seat 525 and through an upper right side threaded outlet 530 ("right side" with respect to the front view of the fifth probe-holding module 500). Moreover, the fifth probe- holding module 500 is provided with a groove 560 on the left side wall that communicates with the lower right side hollow seat 570 through a lower left transverse duct 565.

The fastening of the probe-holding modules is guaranteed by ties constrained in the probe-holding modules operated by grub screws, allowing the coupling between probe-holding modules without constraints of consecutiveness apart from the first type of probe-holding module 100 that, in the modular probe-holders shown in the Figures to which the preferred embodiment of the mechanical coupling assembly is applied, must be always the first module of the series of assembled modules which form the modular probe-holder and apart from the fifth type of probe-holding module 500 that, in the modular probe-holders shown in the Figures, must be always the last module of the series of assembled modules which form the modular probe-holder.

To this end, the second, the third and the fourth type of probe-holding modules 200, 300 and 400 are provided on the front and rear walls with a pair of upper left threaded holes 600 communicating with a pair of respective upper left side seats 650 communicating externally and having longitudinal axis orthogonal to the axis of the respective threaded hole 600, a pair of upper right threaded holes 610 communicating with a pair of respective upper right side seats 660 communicating externally and having longitudinal axis orthogonal to the axis of the respective threaded hole 610, a pair of lower left threaded holes 620 communicating with a pair of respective lower left side seats 670 communicating externally and having longitudinal axis orthogonal to the axis of the respective threaded hole 620, and a pair of lower right threaded holes 630 communicating with a pair of respective lower right side seats 680 communicating externally and having longitudinal axis orthogonal to the axis of the respective threaded hole 630; each one of the threaded holes is configured to receive a grub screw, while each one of the seats communicating with the threaded holes is configured to partially receive a tie.

The first type of probe-holding module 100 is provided on the front and rear walls with only the pair of upper right threaded holes 610 and the pair of lower right threaded holes 630, each one of which is also configured to receive a grub screw, communicating with respective upper and lower right side seats 660 and 680, each one of which is also configured to partially receive a tie.

The fifth type of probe-holding module 500 is provided on walls front and rear walls with only the pair of upper left threaded holes 600 and the pair of lower left threaded holes 620, each one of which is also configured to receive a grub screw, communicating with respective upper and lower left side seats 650 and 670, each one of which is also configured to partially receive a tie.

However, it should be understood that other modular probe-holders may have probe- holding modules configured to house amperometric sensor (for instance a horizontal amperometric sensor housed in a front hollow seat or a vertical amperometric sensor housed in a corresponding seat) and which may be coupled to other modules in any position along the series of assembled modules forming the modular probe-holder (i.e. not necessarily placed as last module); in this case, such probe-holding modules configured to house amperometric sensors are provided with the same assembly of pairs of threaded holes 600, 610, 620 and 630 and of communicating seats 650, 660, 670 and 680 with which the second, the third and the fourth type of probe-holding modules 200, 300 and 400 are provided.

Moreover, other modular probe-holders may have probe-holding modules configured to house flow meters which may be coupled to other modules in any position along the series of assembled modules forming the modular probe-holder (i.e. not necessarily placed as first module); such probe-holding modules configured to house flow meters are also provided with the same assembly of pairs of threaded holes 600, 610, 620 and 630 and of communicating seats 650, 660, 670 and 680 with which the second, the third and the fourth type of probe- holding modules 200, 300 and 400 are provided.

With reference to Figure 3, wherein by way of example and not by way of limitation a modular probe-holder constituted of an ordered series of a first type, a second type, a third type and a fifth type of probe-holding modules 100, 200, 300 and 500 is shown, it may be observed that the ties 700 are inserted into the pairs of facing side seats 650, 660, 670 and 680 of two adjacent probe-holding modules and afterwards the grub screws 710 are screwed into the threaded holes 600, 610, 620 and 630, causing the adjacent probe-holding modules to get closer. As stated, such fastening is present on both front and rear faces of the probe-holding modules.

In order to better understand the operation of the grub screws 700 and ties 710 reference can be made to Figure 4, wherein an enlargement of a cross-section of a coupling zone of two adjacent probe-holding modules (generically indicated with the reference numerals 10 and 20) comprising a tie 700 inserted into a pair of corresponding facing side seats is shown. The tie 700 comprises two holes 701 each configured to receive the tip 711 of a grub screw 710 screwed into a respective threaded hole (the threaded holes are generically indicated with the reference numerals 15 and 25). In particular, the tip 711 of a grub screw has a conical lateral surface, optionally with apex angle equal to 90° (whereby the side surface has an inclination of 45° with respect to the longitudinal axis of the grub screw 710), and the hole 701 and tie 700 have a corresponding support inclined surface, optionally with inclination of 45° with respect to the longitudinal axis of the hole 701.

The area of contact between tip 711 of the grub screw 710 and hole 701 of the tie 700 only comprises the portion of the support inclined surface of the hole 701 of the tie 700 that is farthest from the adjacent probe-holding module (20 or 10). To this end, when the tie 700 is symmetrically arranged in the pair of corresponding facing side seats, there is an offset between the longitudinal axis of each one of the threaded holes 15 and 20 (coinciding with the longitudinal axis of the grub screw 710 inserted into such threaded hole) and the longitudinal axis of the hole 701 of the tie 700; optionally, when the two adjacent probe-holding modules 10 and 20 are coupled, the distance DA between the longitudinal axes of the two threaded holes 15 and 20 (communicating with the pair of side seats facing the two adjacent probe- holding modules 10 and 20) is larger than the distance DB between the longitudinal axes of the holes 701 of the tie 700, optionally by an amount ranging from 2% to 3%, more optionally by an amount equal to 2,5% (whereby DA=1,025*DB).

When a grub screw 710 is screwed into the respective threaded hole (15 or 25), it advances longitudinally (along the direction of the arrow A) exerting a force (along the direction of the arrow B) perpendicular to the support surface of the respective hole 701 of the tie 700. The preferred inclination angle of the side surface of the tip 711 of the grub screw, equal to 45°, maximises the area of contact between tip 711 of the grub screw 710 and hole 701 of the tie 700 dedicated to the transmission of forces. The horizontal component of such force produces a constraint reaction (along the direction of the arrow C) on the portion of the surface of the threaded hole (15 or 25) closest to the adjacent probe-holding module (20 or 10), causing the two adjacent probe-holding modules 10 and 20 to get closer to each other.

With reference to Figures 2b and 5a, wherein by way of example and not by way of limitation a probe-holding module 500 of the fifth type configured to house an amperometric sensor is shown, it may be observed that the preferred embodiment del mechanical coupling assembly according to the invention comprises, on the left side wall of the probe-holding modules, a seal groove 800 arranged so as to surround the groove 560 of the probe-holding module 500 and, when the latter is coupled to an adjacent probe-holding module (100, 200, 300 or 400), also the upper left side outlet (130, 230, 330 or 430) on the left side wall of the adjacent probe-holding module (100, 200, 300 or 400). The seal groove 800 is configured to house an O-ring seal 810 of elastic material, optionally of fluoroelastomer known as FPM or FKM, with optionally circular cross-section, whereby the seal 810 is capable to ensure the sealing of the coupling between adjacent probe-holding modules since it surrounds the path of the fluid when passing from one to the other of the two adjacent probe-holding modules.

As shown in Figure 5b, wherein an enlargement of a cross-section of a coupling zone of two adjacent probe-holding modules (generically indicated with the reference numerals 10 and 20) comprising a groove 800 housing a seal 810 is shown. In particular, the two adjacent probe- holding modules shown in Figure 5b operate as hydraulic components of the mechanical coupling assembly according to the invention. The geometry and size of the groove 800 and seal 810 are such that they guarantee the compression of the seal 810 when the two adjacent probe-holding modules 10 and 20 are coupled, so as to compensate planarity errors (i.e. surface irregularities) of the facing walls (i.e. of the opposing walls) of the two adjacent probe- holding modules 10 and 20. In this way, the seal 810 ensures the correct operation of the modular probe-holder with both fluid in static conditions and moving flow under several operation conditions, for instance at a first condition with fluid temperature of 25°C and fluid pressure of 10 bar and at a second condition with fluid temperature of 70°C and fluid pressure of 7 bar. Advantageously, the deformation of the seal 810 mainly concerns the direction orthogonal to the walls of contact of two adjacent probe-holding modules 10 and 20. The groove 800 has rectangular cross-section, with depth p and width w equal to the diameter w of the seal 810 with circular cross-section, wherein p is lower than the diameter w; in particular, p is optionally not larger than 95% of w (whereby p < 0,95*w), more optionally not larger than 85% (whereby p < 0,85*w), still more optionally not larger than 80% (whereby p < 0,80*w), even more optionally ranging from 65% to 75% of w (whereby 0.65*w < p < 0,7*w), still even more optionally equal to 70% of w (whereby p=0,7*w). In this case, even when the single probe-holding modules provided with the seal housed in the groove are disassembled, the seal stably remains in the groove even if the module is moved. In other words, the sealing effect is given by the deformation of the seal 810 during fastening of two adjacent probe-holding modules 10 and 20. The specific torque of fastening of the grub screws 710 and the absence of vibrations during the operation of the modular probe-holder do not render the use of self- locking devices necessary and ensure the compression imposed to the seal 810 for the entire lifetime of the modular probe-holder. Optionally, the hardness of the seal is not lower than 50 shore A (SHA), more optionally not lower than 60 SHA, in order to avoid that the seal is extruded between the walls of the two adjacent probe-holding modules 10 and 20.

In the modular probe-holders shown in the Figures to which the preferred embodiment of the mechanical coupling assembly is applied, since the first type of probe-holding module 100 is the first module of the series of assembled modules forming the modular probe-holder, such first type of probe-holding module 100 is not provided on the left side wall with the seal groove 800.

Other modular probe-holders may have the probe-holding modules having a seal groove on the right side wall, instead of the left side wall, still arranged so as to surround the path of the fluid when passing from one to the other of the two adjacent probe-holding modules. In the case where the fifth type of probe-holding module 500 is still always the last module of the series of assembled modules forming a modular probe-holder, such fifth type of probe-holding module 500 would not be provided on the right side wall with such seal groove.

Further embodiments of the mechanical coupling assembly according to the invention applied to modular probe-holders may have the probe-holding modules which have a seal groove on both the left side wall and the right side wall, configured such that they do not overlap with the seal groove respectively on the right side wall and the left side wall of two other adjacent modules, both the seal grooves on the two side walls being arranged so as to surround the path of the fluid when passing from one to the other of the two adjacent probe- holding modules. In any case, each seal is housed in only one respective groove present on only one wall of the two components.

It should be understood that the specific arrangement of the seal groove configured to house an O-ring seal, illustrated with reference to Figures 2b and 5, is applicable to any mechanical coupling of two components (not necessarily hydraulic components) through respective walls on which two apertures which can create a passage for a fluid flowing from one element to the other are present.

It should be further understood that the mechanical means for coupling the two components (e.g. the two probe-holding modules shown in the Figures) is not a feature essential to the mechanical coupling assembly according to the invention, and it can be different from that illustrated with reference to the Figures also in function of the type, shape and size of the components (not necessarily hydraulic components) which have to be coupled. By way of example, and not by way of limitation, such coupling mechanical means may also comprise or consist of at least one flange and/or rivets and/or screws and bolts.

By way of example, reference to Figure 6, it may be observed that the coupling mechanical means used in another modular probe-holder, to which the preferred embodiment of the mechanical coupling assembly according to the invention is applied, comprises, instead of grub screws and ties, threaded studs 750 screwed in suitable transverse through holes accessible on the side walls of the single probe-holding modules. Differently from the solution adopted in the modular probe-holder shown in Figures 3 and 4, the coupling through threaded studs 750 imposes that, in order to access a probe-holding module of a series of assembled modules forming the modular probe-holder, it is necessary to disassemble all the subsequent probe-holding modules.

Figure 7, wherein by way of example and not by way of limitation a modular probe- holder constituted by an ordered series of a first type, a second type, a third type and a fifth type of probe-holding module 100, 200, 300, and 500 (illustrated with reference to Figures 1 and 2) is shown, each one of which houses a respective sensing probe, shows the path of the water flow (schematically represented by the arrows in Figure 7) in the modular probe-holder to which the preferred embodiment of the mechanical coupling assembly according to the invention is applied. In particular, the entrance of the water flow in the modular probe-holder occurs through a tube-holder 900 coupled in the lower threaded mouth 120 of the first probe- holding module 100. The longitudinal ducts 110, 210, 310 and 510 of the probe-holding modules 100, 200, 300, and 500 guarantee that the fluid is moved from the bottom upwards inside each probe-holding module and that it has a constant velocity along the entire probe- holding module. The exit of the flow from each probe-holding module always occurs from the right wall of the same module, in particular from the upper right side outlets 130, 230, 330 and 530 of the probe-holding modules 100, 200, 300, and 500. The path of the fluid when passing from the previous to the next of two adjacent probe-holding modules occurs along the grooves on the left side walls 260, 360 and 560 of the next probe-holding module, as shown by the enlarged particular of Figure 7b related to the passage from the second probe-holding module 200 to the third probe-holding module 300. The flow exiting from the last probe-holding module of the series, that in Figure 7 is the fifth probe-holding module 500, is channelled by screwing a tube-holder 910 (shown enlarged in Figure 7c) into the upper right side outlet. The lower threaded mouths 220, 320 and 520 of the second, third and fifth probe-holding modules 200, 300, and 500, as well as the upper threaded mouths 125, 225, 325 and 525 of all the probe-holding modules 100, 200, 300, and 500 are closed by caps 920 and other devices 930 and 940 (e.g. electrodes and taps), whereby they do not provide the flow shown in Figure 7 with other exits.

Making reference again to Figures 1 and 2, all the probe-holding modules are provided, on the rear wall, with a pair of upper rear threaded holes 850 and with a pair of lower rear threaded holes 860 configured to receive a screw for fastening rear brackets allowing the modular probe-holder to be fixed to a wall or support plate. Such rear brackets are fixed to the probe-holding modules at the ends of the series of assembled modules forming the modular probe-holder. By way of example, and not by way of limitation, Figure 8 shows a modular probe-holder constituted by a first type and a fifth type of probe-holding modules 100 and 500 to which two rear brackets 950 have been fixed through screws 960 inserted into the rear threaded holes 850 and 860; the rear brackets 950 are provided with holes 955 for the fastening through conventional means, such as Fischer plugs, to a wall or support plate.

The probe-holding modules allow to make modular probe-holders having any configuration.

The preferred embodiments of this invention have been described and a number of variations have been suggested hereinbefore, but it should be understood that those skilled in the art can make other variations and changes, without so departing from the scope of protection thereof, as defined by the attached claims.