Patent Description:
A sensor device having the characteristics specified in the preamble of Claim <NUM> is known from the <CIT> filed in the name of the present applicant.

The above document describes a pressure-sensor device the sensitive component of which has a sensor body with a blind cavity, the bottom of which is formed by a membrane part. The membrane part is elastically deformable, and associated thereto is a sensing element, such as a bridge of resistive or piezoresistive elements. The device has a casing made up of a number of parts, amongst which a body for supporting the sensor body. The supporting body is traversed axially by a duct, the inlet end of which is at a hydraulic-attachment portion of the casing; the outlet end of the duct instead faces the cavity of the sensor body.

In certain applications, the devices of the type referred to operate in conditions of very low temperature, and it may occasionally happen that the fluid being measured freezes, thus increasing in volume. Given that the membrane part of the sensor body is usually relatively thin and delicate, it is important to adopt solutions that prevent its failure and/or damage of the corresponding sensing element following upon the increase in volume of the fluid due to freezing.

The prior document referred to consequently proposes association to the supporting body of one or more compressible compensation bodies, i.e., elements suitable for compensating possible increases in volume of the fluid following upon its freezing.

The solution envisages the use of "external" compensation elements, i.e., ones mounted on the outside of the supporting body substantially at the cavity of the sensor body, or else "internal" compensation elements, i.e., ones directly inserted in the axial duct of the supporting body, at a certain distance from the membrane of the sensor body. The document referred to also suggests the possibility of forming an internal compensation element and an external compensation element in a single compressible body. This single body is by its nature yielding, and this enables installation thereof on the supporting body, with a corresponding part inside the axial duct and another part outside the aforesaid duct in order to project into the cavity of the sensor body.

The pressure-sensor devices proposed in the prior document referred to are on average efficient from the functional standpoint, but still present some drawbacks in terms of reliability and/or production times and costs, which it would be desirable to reduce.

<CIT> discloses a pressure sensor with a compressible insert to prevent damage from freezing. <CIT> discloses a pressure sensor with a cavity casing having a fluid inlet passage for a fluid and a sensor circuit arrangement, where a protection body is surrounding the pressure sensor, and cooperating for sealing purposes with an internal surface of the casing. <CIT> discloses a pressure sensor device having an adaptor support and a detection part between which an elastic material or an adhesive or a material adapted to compensate different dilatations or dimensional variations is set.

In its general terms, the aim of the present invention is consequently to provide an improved pressure-sensor device that is simpler and more economically advantageous to produce as compared to the devices according to the prior art and presents a further increased reliability.

One or more of the above aims is achieved, according to the present invention, by a pressure-sensor device according to claim <NUM>.

Further objects, characteristics, and advantages of the invention will emerge clearly from the ensuing detailed description, with reference to the annexed plates of drawings, wherein:.

Hence, phrases such as "in an embodiment" or "in one embodiment" and the like that may be present in various points of this description do not necessarily refer to one and the same embodiment, but may, instead, refer to different embodiments. Furthermore, particular conformations, structures, or characteristics defined in this description may be combined in any adequate way in one or more embodiments, even different from the ones represented. The reference numbers and spatial references (such as "upper", "lower", etc.) are used herein only for convenience and hence do not limit the scope of protection or the scope of the embodiments. In the figures, the same reference numbers are used to designate elements that are similar or technically equivalent to one another.

In <FIG>, designated as a whole by <NUM> is a sensor device, in particular a pressure-sensor device. The device <NUM> has a housing or supporting structure that comprises a body, designed to house and/or support a component sensitive to a quantity to be detected, here a pressure. The aforementioned body is preferably configured like a casing, as in the example illustrated, having an electrical-connection portion and a hydraulic-connection portion.

In the case exemplified, the housing or supporting structure, also defined hereinafter for simplicity as "casing", is made up of at least two main parts, amongst which a first body <NUM>, hereinafter defined also as "supporting body" <NUM>, which preferably performs also functions of hydraulic connection, and a second body <NUM>, hereinafter defined also as "closing body" <NUM>, which preferably performs functions of housing and electrical connection. Preferably, the casing is configured for protecting the sensitive component, in particular from the external environment. In various embodiments, the parts <NUM> and <NUM> contribute to defining a casing that encloses, at least in part, and/or protects the sensitive component in regard to the external environment, albeit envisaging appropriate passages for at least one quantity to be detected, such as a passage for a fluid the pressure of which is to be detected, and possibly one or more further passages towards the external environment, for example to have available a reference pressure.

As emerges also from <FIG> and <FIG>, the bodies <NUM> and <NUM> are coupled together, preferably in a fluid-tight way, so as to define a space <NUM> within which a component sensitive to the quantity to be detected is housed. In the example illustrated, the sensitive component has a sensor body <NUM> with a membrane part 5a that is elastically deformable as a function of the pressure of the fluid being measured. The sensor body <NUM> is housed at least partially in at least a part of the casing. In what follows, for simplicity, the part 5a will be defined also simply as "membrane". The membrane 5a may be made integrally in the sensor body <NUM> or else be configured as a separate part associated to the sensor body <NUM>, for example via welding or gluing.

As per a known technique, the sensitive component has associated to it at least one element designed to detect the deformation of the membrane part 5a. This detection or sensing element, designated by <NUM> only in <FIG>, may comprise a plurality of resistors or piezoresistive elements, for example in bridge configuration, preferably obtained on the side of the membrane 5a not exposed to the fluid the pressure of which is to be measured. In other embodiments (for example, as in the case of <FIG> according to the invention) the detection element <NUM> may comprise electrodes and/or capacitive elements, such as for example two facing electrodes, preferably obtained at least in part on a side of the membrane 5a not exposed to the fluid.

In one example not forming part of the invention, such as the one exemplified, the sensor body <NUM> is monolithic, made preferentially of a ceramic material (for example, alumina), so as to define a blind cavity (not indicated) having a peripheral surface and a bottom surface, with the latter that belongs to the membrane 5a (in particular, to the inner side thereof). The aforesaid peripheral and bottom surfaces are designated by 5b and 5c, respectively, only in <FIG>.

In one embodiment, present within the space <NUM> defined by the casing <NUM>-<NUM> is a circuit <NUM> that includes a respective support, mounted on which are electrical components and/or electronic components for control and/or treatment and/or processing of a signal generated by the detection element <NUM>. The detection element <NUM> is in signal communication with the circuit <NUM> via conductors <NUM> that rise from the face of the sensor body <NUM> that includes the membrane 5a, here defined for simplicity as "upper face" or "upper surface". The conductors <NUM> are connected to respective conductive pads or paths provided on the support of the circuit <NUM>. Provided between the upper face of the sensor body <NUM> and the support of the circuit <NUM> is a spacer element <NUM>, which co-operates with at least a part of the casing (for example, the part <NUM>) and has also functions of positioning of the support of the circuit <NUM> with respect to the sensor body <NUM> and to the casing itself. Associated to the support of the circuit <NUM> are elastic contacts, one of which is designated by <NUM> in <FIG> (see also <FIG>), that set in contact electrically conductive pads or paths of the support of the circuit <NUM> to respective terminals <NUM> associated to the casing part <NUM>. As emerges, in particular, from <FIG> and <FIG>, in one embodiment, the terminals <NUM> have a substantially L-shaped configuration, or in any case have a portion outside the space <NUM> and a portion inside the space <NUM>. The casing part <NUM> then defines a tubular portion 3a - which here extends in a generally axial direction - extending within which are the external portions of the terminals <NUM>, to provide an electrical connector. The parts of the contacts <NUM> opposite to the support of the circuit <NUM> are held elastically against the internal portion of corresponding terminals <NUM>. In one embodiment, the elastic contacts <NUM> are obtained according to the specific teachings contained in <CIT>, filed in the name of the present applicant.

In one embodiment, the circuit is obtained directly on the sensor body <NUM>, mounted on which are the aforesaid electrical components: the conductors <NUM> may hence even be absent. In this case, associated to the circuit obtained on the sensor body <NUM> are elastic contacts <NUM> that set in contact electrically conductive pads or paths of the circuit itself to respective terminals <NUM> associated to the casing part <NUM> of the device <NUM>. The terminals <NUM> have a configuration designed to couple electrically and mechanically with at least a part or end of the elastic contacts <NUM>.

The supporting body <NUM> has a hydraulic-connection portion 2a, preferably having a cylindrical shape, provided on the outside of which is an external sealing element <NUM>, here of an annular shape, for example an O-ring. The portion 2a of the body <NUM> is designed for connection to a line flowing in which is the fluid the pressure of which is to be detected. The opposite part of the supporting body <NUM>, i.e., its upper face or surface, is configured peripherally - in a way in itself known - for coupling with the casing part <NUM>. Branching off from the hydraulic-connection portion 2a is a duct, designated by <NUM>, which extends through the body <NUM>, preferably in an axial direction, as far as its upper face. In one or more embodiments, the duct <NUM> defines, at least in part, a passageway <NUM> for the fluid the pressure of which is to be detected. In one embodiment, as will be seen, a part of the passageway <NUM> may be defined by a body that is at least in part elastically deformable, associated to the supporting body <NUM>, formed with one or more elastically compressible and/or yielding materials, and configured for compensating any possible variations in volume of the fluid.

The deformable body is preferably shaped so as to define one or more elastically compressible compensation elements. In addition or as an alternative, the deformable body may define one or more functional elements that perform, for example, sealing and/or supporting functions for the sensitive element and/or the casing.

A non-limiting example of such an elastically deformable body is designated as a whole by <NUM> in <FIG>.

In an example of embodiment, as will be seen, the body <NUM> defines two elements for compensation of any possible variations in volume of the fluid, which define respective portions of the passageway <NUM>, but not excluded from the scope of the invention is the case of a deformable body that defines a single compensation element, or else again the case where the passageway <NUM> is entirely defined or practically entirely defined by a deformable body associated to the duct <NUM>.

The sensor body <NUM> is mounted on the supporting body <NUM> in such a way that its membrane 5a is exposed to the fluid coming out of the passageway <NUM>, in particular facing the outlet of the latter. In one embodiment, the device <NUM> further comprises an internal sealing element, designated by <NUM>, which is set between the supporting body <NUM> and the sensor body <NUM>, to define with them a chamber for collecting the fluid, designated by <NUM>. The passageway <NUM> gives out into the aforesaid chamber <NUM> so that the pressure of the fluid can be exerted on the membrane 5a.

In one example, such as the one exemplified, the supporting body <NUM> has, at its upper face, a projecting central portion, visible in particular in <FIG> where it is designated as a whole by <NUM>. The internal sealing element <NUM> extends around the aforesaid portion <NUM> so as to provide a radial seal between the portion <NUM> and the sensor body <NUM>, in particular the peripheral surface 5b of its blind cavity.

In one embodiment, for example as in the one illustrated, the deformable body <NUM> defines two different compensation elements <NUM> and <NUM>, here defined as "internal" and "external", respectively.

The internal compensation element <NUM>, which extends at least in part into the duct <NUM>, delimits a respective part of the passageway <NUM> and has a generally cylindrical and/or frustoconical shape, or in any case a tubular shape in so far as it is provided with an axial through hole. The external compensation element <NUM> is, instead, set in a position generally facing the membrane 5a of the sensor body <NUM> and extends at least in part on the outside of the duct <NUM>, in particular at the top of the projecting portion <NUM> of the supporting body <NUM>, in a position relatively close to the membrane itself. Also the external compensation element <NUM> is provided with an axial through hole and, preferably, has a generally flattened shape, for example the shape of a disk or a cap.

As may be noted in <FIG>, the external compensation element <NUM> is located preferentially within the blind cavity of the sensor body <NUM>, with its peripheral and upper surfaces relatively close to the peripheral surface 5b and bottom surface 5c, respectively, of the aforesaid cavity. In one embodiment, the compensation element <NUM> has one or more through openings in peripheral positions, some of which are designated by 21a in <FIG>. These openings 21a traverse the element <NUM> between its two opposite major faces and basically have the function of connecting together different regions of the collection chamber <NUM> in order to keep them in fluid communication and balance them in pressure, for the purposes and with the modalities described in <CIT> filed in the name of the present applicant. In possible variant embodiments, the openings 21a are replaced by a lobed shape of the element <NUM>, or by axial grooves or slits provided in a region corresponding to the outer profile or a central passage of the element <NUM>, or once again provided in the projecting portion <NUM> of the body <NUM>, according to the teachings of <CIT>.

In one embodiment, the compensation elements <NUM> and <NUM> are joined together, i.e., are made of a single piece - here the deformable body <NUM> - formed with one or more elastically compressible and/or yielding materials, for example a silicone.

In one embodiment, such as the one represented, the supporting body <NUM> defines a transverse wall 2b of the duct <NUM>. Preferentially, the wall 2b has a relatively small thickness, for example smaller than the thickness of the element <NUM> or the thickness of the wall defining the connection portion 2a of the body <NUM>. In the case of the device <NUM> of <FIG> and <FIG>, the aforesaid transverse wall 2b is located at end of the duct <NUM> opposite to the hydraulic-connection portion 2a, i.e., with the outer side of the wall 2b that belongs to the upper face of the body <NUM>. As may also be appreciated from <FIG>, the transverse wall 2b is provided with at least one first through opening <NUM>, which delimits a respective part of the passageway <NUM>, as emerges clearly from <FIG> and <FIG>. In one embodiment, the opening <NUM> is in a central position of the wall 2b and axially aligned to a through hole of a compensation element <NUM> and/or <NUM>. In the embodiment of <FIG>, the duct <NUM> hence extends in part through the projecting portion <NUM>, provided at the top of which is the wall 2b having the opening <NUM> at the centre.

In one embodiment, moreover associated to the body <NUM> is a supporting element <NUM>, which is located on the outside of the collection chamber <NUM> and is configured for elastically supporting the sensor body <NUM> in an axial direction. The supporting element <NUM> is preferably set between the upper face of the body <NUM>, in a position that generally surrounds its projecting portion <NUM>, and the lower face of the sensor body <NUM>, in a peripheral area of the aforesaid face that surrounds the opening of the corresponding blind cavity. The element <NUM> can perform also hydraulic sealing functions in so far as it is elastically deformable.

The presence of the elastic supporting element <NUM> is particularly important in those embodiments of the device <NUM> in which the sensor body <NUM> is constantly urged in an elastic way towards the supporting body <NUM>, in particular, via the action of the elastic contact elements <NUM>. The aforesaid requirement is not, for example, present in the devices according to the prior art, such as the ones described in <CIT>, in which the sensor body is not subject to elastic loads towards the corresponding supporting body.

According to a preferential aspect, at least one from among the internal sealing element <NUM>, the supporting element <NUM> and the external sealing element <NUM> is configured as a part that is at least partially overmoulded on the supporting body <NUM> or co-moulded therewith.

It is pointed out that, in the sequel of the present description and in the attached claims and where not otherwise specified, the generic term "overmoulding" and its derivatives are understood as designating at least two different moulding techniques, and specifically the overmoulding technique in a strict sense and the co-moulding technique. In the overmoulding technique in a strict sense, a first component previously obtained (here the supporting body <NUM>) is inserted in a mould, into which there is then injected, in the molten state, at least one material that is to form a second component (here the compressible body <NUM>) on the first component. Instead, in the co-moulding technique, in a particular mould there is first injected, in the molten state, at least one material designed to form the first component, after which a part of the mould is replaced - frequently in an automatic way - with a different part, and in the new mould thus formed, which still houses the first component, there is injected, in the molten state, at least one material to obtain the second component on the first component (alternatively, the aforesaid part of the mould can be rotated, instead of replaced, in such a way that a different portion thereof comes to form part of the moulding impression). In practice, then, in the first case, the first component is obtained apart, is introduced into the mould, and the second component is moulded thereon, possibly with the use of a promoter of adhesion (primer) distributed over at least part of the first component, whereas in the second case both of the components are obtained, one after another, in at least part of the same moulding apparatus, preferably overmoulding the second component almost immediately, in particular after a few seconds or a few tens of seconds, when the first component is still hot or has not yet reached room temperature. In both cases, however, one component is moulded on the other.

According to a preferential aspect, at least one from among the internal sealing element <NUM>, the supporting element <NUM>, and the external sealing element <NUM>, possibly together with at least one compensation element, is overmoulded at least in part on the casing body, immediately after moulding of the latter, preferably when the casing body is still hot or has not reached room temperature. This approach proves useful in order to determine a better structural fixing and/or chemical bonding between the material of the body <NUM> and the material of the overmoulded element or elements.

According to a preferential aspect, at least one from among the internal sealing element <NUM>, the supporting element <NUM> and the external sealing element <NUM>, possibly together with at least one compensation element, is overmoulded at least in part on the casing or on the supporting body <NUM> after a promoter of adhesion or primer has been deposited on at least part of the latter, in particular in order to determine a better structural fixing and/or chemical bonding between the material of the casing or of the supporting body <NUM> and the material of the overmoulded element or elements.

Preferably, the material of the overmoulded element or elements has characteristics such as to adhere or adapt to the supporting body, in particular binding structurally and/or penetrating into the possible surface micro-roughnesses or porosities during moulding, improving the corresponding seal, for example as compared to a seal obtained merely by compression of a sealing element formed separately and pressed elastically against the supporting body.

The fact that one or more from among the internal sealing element <NUM>, the supporting element <NUM> and the external sealing element <NUM> are overmoulded on or co-moulded with the supporting body <NUM>, possibly but not necessarily together with at least one compensation element, facilitates considerably production of the device <NUM> as a whole, reducing the operations and apparatuses necessary for its assembly and the corresponding times, likewise ensuring a high precision of positioning between the parts in question. The aforesaid solution moreover enables the overmoulded element or elements to be held in a well-defined position, thereby preventing any undesirable displacement or erroneous assemblage thereof that might arise in the production stage or during use of the device.

In one or more embodiments, just one of the aforesaid elements is overmoulded or co-moulded, whereas in other embodiments two or more of the aforesaid elements are overmoulded on or co-moulded with the supporting body. Two or more of the aforesaid elements may also be made of a single piece, i.e., be joined together and/or be obtained during one and the same step of injection or moulding.

In various embodiments, the material used for overmoulding is a full material, i.e., not an expanded or cell-foam material.

In a preferred embodiment, the elastically deformable body provides at least one compensation element, i.e., a compressible element that performs functions of compensation for any possible variations in volume of the fluid, which is configured as part overmoulded on the supporting body. According to an aspect, one or more from among the internal sealing element, the supporting element, and the external sealing element can be overmoulded together with the aforesaid compressible compensation element.

According to an aspect, the deformable body that defines at least one compensation element also defines at least one from among the internal sealing element, the supporting element and the external sealing element. One or more of the aforesaid elements may thus be formed in a single body with a compensation element, preferably a compensation element housed in the duct <NUM> of the supporting body <NUM>, even though not excluded is formation of one or more of the aforesaid components in a single body with a compensation element external to the duct <NUM>.

According to another aspect, at least one from among the internal sealing element <NUM>, the supporting element <NUM> and the external sealing element <NUM> can be overmoulded as a single component in order to provide a respective elastically deformable body, or else two or more of the aforesaid elements can be made of a single piece. In various embodiments, a single elastically deformable component or a plurality of elastically deformable components are overmoulded on at least a part of the casing <NUM>, <NUM> and/or on the sensitive element.

According to various embodiments, it is possible to overmould a compensation element, such as the element <NUM> or the element <NUM>, with a first elastomeric material, such as a silicone, and then carry out a second overmoulding with a second elastomeric material in order to obtain one or more of the elements <NUM>, <NUM>, and <NUM>. Consequently, at least one from among the deformable body <NUM>, the internal sealing element <NUM>, the supporting element <NUM> and the external sealing element <NUM> may be formed or moulded in different steps and/or with different materials. For this purpose, it may be envisaged to use respective moulds for each step and/or to replace at least part of the mould for each step. Preferably, at least one deformable body <NUM> or a compensation element <NUM> and/or <NUM> is made of a first material and at least one from among the internal sealing element <NUM>, the supporting element <NUM> and the external sealing element <NUM> is made of a second material or elastomer. Preferentially, the first material has a lower hardness or requires a lower force to obtain a compression or elastic deformation as compared to the second material.

In one embodiment, the deformable body defines the internal compensation element, the external compensation element, and at least one from among the internal sealing element, the supporting element and the external sealing element: such a case is, for example, the one represented in <FIG>, where the body <NUM> defines, not only the elements <NUM> and <NUM>, but also the elements <NUM> and <NUM>.

In a preferred embodiment, in particular when the body <NUM> defines in a single piece the compensation elements <NUM> and <NUM>, the transverse wall 2b of the body <NUM> is provided with one or more second through openings, some of which are designated by <NUM> in <FIG>, preferably in a position that is peripheral or eccentric with respect to the opening <NUM>.

Preferentially, a plurality of the aforesaid openings <NUM> are provided, arranged around the opening <NUM> that delimits part of the passageway <NUM>. In one embodiment, the openings <NUM> are arranged according to a circumference or arc of circumference. Preferentially, the openings <NUM> have a cross section or profile that is at least in part curved. The openings <NUM> may also comprise a number of stretches (not represented) that extend in different directions, such as stretches that extend in at least one from among a radial direction, a transverse direction, an angled direction, a parallel direction, or an orthogonal direction with respect to the direction of extension or axis of the duct <NUM>. The openings <NUM> are occupied by respective portions of the deformable body <NUM>, one of which is designated by 16a in <FIG>, which connect together the compensation elements <NUM> and <NUM>.

Preferably, the compensation elements <NUM> and <NUM> are joined via respective portions 16a of the deformable body <NUM> arranged around at least part of the passageway <NUM>, in particular arranged according to a circumference or arc of circumference. Preferably, the portions 16a of the body <NUM> have a cross section or outer profile that is at least in part curved. As has been said in relation to the openings <NUM>, also the portions 16a may comprise a number of stretches (not represented) that extend in different directions, such as stretches that extend in at least one from among a radial direction, a transverse direction, an angled direction, a parallel direction, or an orthogonal direction with respect to the direction of extension or axis of the duct <NUM>.

In a preferred embodiment, the supporting body <NUM> has one or more passages that branch off from or extend each from the duct <NUM>, in particular in at least one direction that is at least in part generally radial or transverse or angled or orthogonal to the direction of extension or axis of the duct <NUM>.

Some of the aforesaid passages are exemplified in <FIG>, where they are designated by <NUM>. In various embodiments, such as the one illustrated, the passages <NUM> also have at least one respective stretch that extends in a direction at least approximately axial or parallel to the axis of the duct <NUM>.

The passages <NUM> may possibly comprise surface grooves or recesses of the supporting body. In the case of <FIG>, for example, at least one portion 25a of the axial stretches of the passages <NUM> is obtained in the form of surface grooves or recesses of the projecting portion <NUM>. In general, the passages <NUM> may be formed in the body <NUM> in a region corresponding to the projecting portion <NUM>, or have respective stretches - in particular stretches that are radial or transverse with respect to the duct <NUM> - underneath the projecting portion <NUM> - or once again radial or transverse stretches in the form of grooves or recesses in the top face of the body <NUM>.

Irrespective of the specific embodiment, the passage <NUM>, or each passage <NUM>, is occupied by a respective portion of the deformable body, for example a portion that connects a compensation element - such as the internal element or the external element - to at least one from among the internal sealing element, the supporting element and the external sealing element. The presence of these connection portions of the deformable body, housed in respective passages <NUM>, guarantees precise positioning and/or fixing of the elements <NUM> and/or <NUM> and/or <NUM> with respect to the body <NUM> and prevents any undesirable displacement thereof.

In a preferred embodiment, at least one portion of the deformable body <NUM>, i.e., of at least one compensation element <NUM>, <NUM> and/or of the internal sealing element <NUM> and/or of the supporting element <NUM> and/or of the external sealing element <NUM>, extends in one or more passages <NUM> that each branch off or extend from the duct <NUM>, in particular one or more portions that have a circular or curved arrangement and/or extend in at least one first direction, which is at least in part generally radial or transverse or angled with respect to the direction of extension or axis of the duct <NUM>, <NUM>, preferably extending also in a second axial or parallel or angled direction with respect to the axis of the duct <NUM>, <NUM>. For example, one or more portions comprise a first stretch and a second stretch that are orthogonal or angled with respect to one another, such as a first stretch that is radial and a second stretch that is substantially parallel to the axis of the duct <NUM>, <NUM>.

In the case of the embodiment here considered, the passages <NUM> contain portions of the deformable body that connect the internal compensation element <NUM> to the supporting element <NUM> and/or to the internal sealing element <NUM>. For instance, at least a part of the passages <NUM> in the form of axial holes or openings of the body <NUM> may house portions for connection to the supporting element <NUM>, whereas a further part of the passages <NUM> shaped like a groove house portions for connection to the internal sealing element <NUM>. Preferably, the internal sealing element <NUM> is joined to the supporting element <NUM>, and the latter is in turn joined to another deformable body, here in a position corresponding to the internal compensation element <NUM>. On the other hand, in possible variant embodiments, the body <NUM> may include different series of passages <NUM> at different heights, for example three series of passages, where the upper series houses connection portions for the internal sealing element <NUM>, the intermediate series houses connection portions for the supporting element <NUM> and the lower series houses connection portions for the external sealing element <NUM>. Obviously possible are various combinations of even just two of the series referred to here by way of example, and/or for each passage or series of passages different combinations of stretches of passage are possible, such as stretches that are at least in part radial and/or axial and/or orthogonal and/or angled with respect to one another and/or with respect to the axis of the body <NUM> or of a duct <NUM>, <NUM>.

Also visible in isolation in <FIG> is an example of deformable body <NUM>, here consisting of a single body formed with one or more materials, which defines the internal compensation element <NUM>, the external compensation element <NUM>, the internal sealing element <NUM> and the supporting element <NUM>. The elements <NUM> and <NUM> are here prevalently tubular and disk-shaped, respectively, even though this does not constitute an essential feature of the solution. The two elements <NUM> and <NUM> each have a respective axial hole or passage, designated by 20b and 21b, for example in <FIG> and <FIG>, these being axially aligned with respect to one another and, together with the through opening <NUM> of the wall 2b, defining the passageway <NUM>. As may be noted in particular from <FIG> and <FIG>, the holes 20b and 21b that traverse the elements <NUM> and <NUM> are substantially aligned axially to the through opening <NUM> of the wall 2b.

Preferably, at least part of the body <NUM> and/or at least part of the overmoulded deformable body <NUM> defines ducts or holes 20b, 21b of small or substantially capillary section, for example with a cross section of between <NUM><NUM> and <NUM><NUM>, in particular in order to predetermine an area of start of freezing of the fluid so as to induce a sort of ice plug designed to counter any high and hence harmful thrusts from outside in conditions of freezing of the fluid being detected.

To return to <FIG>, the internal sealing element <NUM> has an as a whole annular shape, with an approximately semicircular cross section (see also <FIG> and <FIG>) so as to be set up against the peripheral surface 5b of the cavity of the sensor body <NUM> and provide therewith a radial seal with respect to the aforesaid surface. On its opposite side, the sealing element <NUM> is set precisely up against the surface of the body <NUM>, in particular up against the surface of the top projecting portion <NUM>.

Once again visible in <FIG> is the supporting element <NUM>, which is to support in an elastic way the sensor body <NUM> on the body <NUM>. In the example of embodiment illustrated, the element <NUM> has an approximately disk-like or annular shape. Moreover partially visible in <FIG> are some of the connection portions of the deformable body <NUM>, which join the compensation element <NUM> to the elements <NUM> and <NUM>, the aforesaid portions being designated by 16b and 16c (see also <FIG>).

Once again from <FIG> it may be noted how, in a preferred embodiment, the duct <NUM> that traverses the supporting body <NUM> presents an intermediate narrowed portion (not indicated), in such a way that also the internal compensation element <NUM> has two stretches of different diameter or in any case with different cross-sectional dimensions. This solution, together with the fact that the element <NUM> is positioned beyond the transverse wall 2b but connected or fixed with respect to the element <NUM>, guarantees positioning and/or fixing of the deformable body <NUM> as a whole, both in the case of high pressures of the fluid and in the case of violent negative pressures of the fluid or of possible weakening of the material or materials constituting the deformable body <NUM>. The aforesaid fixing is further guaranteed by the preferential structure that envisages a plurality of stretches 16a that extend in respective openings <NUM>, which in effect prevents the deformable body <NUM> from possibly sliding out of the body <NUM>.

Represented in <FIG> is a different embodiment, whereby also passages <NUM> are provided, which are preferably radial or transverse, that branch off from the duct <NUM> substantially at the hydraulic-attachment portion 2a. Housed in these transverse passages <NUM> are respective portions 16d of the deformable body <NUM>, which connect the latter, and in particular the internal compensation element <NUM>, to the external sealing element, here designated by <NUM>'. In this case, then, the external sealing element <NUM>' is overmoulded on the body <NUM> and is in particular defined by the deformable body <NUM>. If need be, the sealing element <NUM>' can be co-moulded with or overmoulded on the body <NUM> in a way independent of the deformable body <NUM> and/or using a different material. The passages <NUM> could have at least some of the characteristics described previously with reference to the openings <NUM> and/or to the passages <NUM>, possibly also comprising a number of stretches that extend in different directions.

Represented schematically in <FIG> is a possible moulding apparatus that can be used for overmoulding of a deformable body <NUM> on a supporting body <NUM>. With initial reference to <FIG>, in the example the apparatus comprises two parts of mould <NUM> and <NUM>. In this example, the part of mould <NUM> defines an impression 30a for positioning the supporting body <NUM>, obtained previously, whereas the part of mould <NUM> defines an impression (31a, in <FIG>) necessary for formation of the deformable body <NUM>.

The apparatus further comprises two sliding blocks or sliders <NUM>, opposite to one another, which may be translated in respective guide passages defined between the parts of mould <NUM> and <NUM>. The sliders <NUM> define at the front respective impressions 32a, which bestow thereon - together with the impression 31a - the outer profile or shape of the deformable body <NUM>. The sliders <NUM> define in particular at least the parts in relief or the recessed parts of the body <NUM>.

According to a variant (not represented), for co-moulding a deformable body <NUM> with a supporting body <NUM>, the apparatus comprises a first part of mould <NUM> defining an impression 30a that, associated to a second part of mould alternative to the part <NUM>, enables definition of an impression corresponding to the supporting body <NUM>, which is obtained by injecting a first material. Subsequently, the aforesaid second part of mould is removed and is replaced by the part of mould <NUM> and by the sliding blocks <NUM> that define the impression 31a, 32a of the deformable body <NUM>, obtained by injecting at least one second compressible and/or compliant material on the supporting body <NUM>.

The overmoulding or co-moulding apparatus envisages at least a part of mould <NUM>, <NUM> provided with an element 30b, 31b, substantially of a cylindrical shape, possibly with different sections or diameters, designed to form at least part of the axial hole or passage 20b, 21b of the deformable body <NUM>, i.e., of the compensation elements <NUM>, <NUM>.

In <FIG> the apparatus is represented in a condition where the mould is closed after the material necessary for formation of the deformable body <NUM> has been injected therein. At the moment of injection of the material, in the molten state, into the mould, the material occupies the free spaces defined between the parts <NUM>, <NUM>, <NUM> and the body <NUM>, as well as the passages (<NUM> and/or <NUM>) of the body itself, thus forming the body <NUM>. It will be appreciated then that, in an application of this type, the supporting body <NUM> itself comes to constitute a sort of "mould part" necessary for definition of the final shape of the deformable body <NUM>. After the necessary period of cooling and solidification of the overmoulded material, the parts of mould <NUM> and <NUM> and the sliders <NUM> can be re-opened, as illustrated schematically in <FIG>, with the body <NUM> by now formed on the body <NUM>.

<FIG> illustrate, with views similar to those of <FIG>, a further embodiment, whereby just the internal sealing element <NUM> is overmoulded on the supporting body <NUM> in a single piece with the compensation elements, i.e., the internal element <NUM> and the external element <NUM>. Consequently, in this solution, the supporting element and the external sealing element are not formed together with other overmoulded parts. In the example, the supporting element is constituted by an annular element <NUM>' made of yielding material, for example a silicone, which is mounted between the upper face of the body <NUM>, to circumscribe the projecting portion <NUM>, and the lower face of the sensor body <NUM>, in particular in the area of the aforesaid face that circumscribes the opening of the blind cavity. Various characteristics described with reference to <FIG> may be applied to the embodiment of <FIG>.

<FIG> illustrate, with views similar to those <FIG>, an embodiment whereby overmoulded on the body <NUM> is a deformable body <NUM> defining just the compensation elements <NUM> and <NUM>, joined together by way of the connection portions 16a that extend through the corresponding through openings formed in the transverse wall 2b of the duct <NUM>. Also to the embodiment non forming part of the invention of <FIG> various characteristics described with reference to <FIG> may be applied.

According to an aspect, there will be additionally present both the internal sealing element and the supporting element, or at least one of them. The internal sealing element is constituted by an annular sealing element <NUM>' made of elastically deformable material, fitted on the projecting portion of the body <NUM> at a corresponding narrowed portion thereof so as to provide a radial seal with respect to the peripheral surface 5b of the cavity of the body <NUM>, and the supporting element is obtained from another annular element <NUM>' similar to the one described with reference to <FIG>.

The presence of an internal sealing element <NUM> or <NUM>' ensures a constant seal with respect to the sensor body <NUM>, which substantially is not affected by the axial position of the sensor body <NUM> with respect to the supporting body <NUM>, considering the fact that the radial compression does not substantially vary if the portion <NUM> of the supporting body <NUM> and the cavity of the sensor <NUM> are both substantially cylindrical and coaxial, or varies only slightly even in the case of frustoconical cavities with slightly inclined walls, thus preventing any infiltration or leakage of the fluid to be detected.

The presence of the supporting element <NUM> or <NUM>' enables of the sensor body <NUM> to be elastically urged and/or supported in the casing <NUM>, <NUM> of the device <NUM>, in particular enabling an assembly in which the sensor body <NUM> can be pushed, without any damage, by the closing body <NUM> and/or by a spacer or positioning element <NUM> towards the supporting body <NUM>. Advantageously, the supporting element <NUM> or <NUM>' enables the sensor body <NUM> and/or the elastic contacts <NUM> of the circuit <NUM> integrated in or associated to the aforesaid body <NUM> to be elastically urged and/or pushed towards the terminals <NUM>.

In this regard, it is to be considered that, in particular in the case of bodies or elements <NUM>, <NUM>, <NUM> made of thermoplastic material, the different distribution of the high dimensional tolerances could lead to combinations in which the sensor body <NUM> is positioned loose or else, instead, the sensor body <NUM> is excessively compressed in the casing <NUM>, <NUM>. There follow possible faults in the device <NUM>, which range from excessive compression and failure during assembly to possible faulty electrical contacts and/or excessive fluctuations of the sensor body <NUM> at the risk of damage, in particular in the presence of high vibrations or stresses in a vehicle.

The supporting element <NUM> or <NUM>' moreover enables provision of an at least in part axial seal between the sensor body <NUM> and at least the supporting body <NUM>, which may be a seal additional to the seal obtained via the internal element <NUM> or <NUM>', when the latter is envisaged.

The supporting element <NUM> or <NUM>' may be shaped so as to be resilient or exert a thrust with respect to the sensor body <NUM> according to vectors or forces oriented in different directions, such as an element <NUM> or <NUM>' that provides a support and/or a seal both in an axial direction and in a radial direction or in any case a direction inclined with respect to the axis of the sensor body <NUM> or of the duct <NUM>.

Preferably, the combination of the internal sealing element <NUM> or <NUM>' and of the supporting element <NUM> or <NUM>' enables the aforesaid internal seal to be obtained, albeit allowing an "elastic assembly", i.e., an assembly that renders possible slight variations or compensations of the axial positioning of the sensor body <NUM>, in particular for compensating the aforesaid dimensional variations of the various elements or parts of the device <NUM>.

<FIG> illustrate a further embodiment of a pressure-sensor device nor forming part of the invention.

In one such embodiment, and as may be noted, in particular, from <FIG>, the blind cavity of the sensor body <NUM> has an intermediate narrowed portion or variation of cross section so as to define a lower cavity portion C', which is wider, and an upper cavity portion C", which is narrower. An embodiment of this sort proves particularly advantageous in so far as it enables a reduction in the dimensions of the membrane 5a, which in this case forms the bottom of the narrower cavity portion C" and to which there is in any case associated a corresponding deformation-detection element, here not indicated.

The use of a sensor body <NUM> with two cavity portions C' and C" having different cross sections enables provision of a lower, wider, cavity portion C', where it is possible to provide more easily the internal radial seal, i.e., to provide a perimetral seal inside the cavity of the sensor body <NUM> via the internal sealing element <NUM> (or <NUM>'), and an upper, narrower, cavity portion C", which may contain a smaller amount of fluid and is thus subject to lower mechanical stresses in the event of freezing and/or expansion of the fluid. Freezing of the smaller amount of fluid that may be contained in the cavity portion C" can moreover be more easily compensated by the compressible element <NUM>.

The area of the upper face of the sensor body <NUM> that surrounds the membrane 5a is hence wider, and corresponding to this area is a portion 5d of the body <NUM> at least partially thicker than in the previous embodiments. In this way, in the above area of the upper face of the body <NUM> there can be directly associated electrical/electronic components for signal control, and/or treatment, and/or processing. The device <NUM> may hence be obtained without the need to provide a support for the circuit <NUM> as in the case of the previous embodiments, or the corresponding spacer and positioning element <NUM>. The concept may be particularly appreciated from <FIG>, from which it emerges how the elastic contacts <NUM> extend in this case directly between the portion of the terminals <NUM> inside the space <NUM> and electrically conductive pads or paths (not indicated) provided directly on the upper face of the sensor body <NUM>, in a position that is peripheral with respect to the membrane 5a, even in a position at least in part corresponding to the portion 5d.

In a solution of this sort, it is preferable for the external compensation element <NUM> to extend at least in part into the upper portion C" of the blind cavity of the body <NUM>. Also in an embodiment of this type, such as the one represented, the element <NUM> may be made of a single piece with the internal compensation element <NUM>, in particular via overmoulding, as already described with reference to previous embodiments, the characteristics of which may at least in part also refer to the present example of embodiment. Also in this case, the internal sealing element <NUM> and/or the lower supporting element <NUM> may be overmoulded on the body <NUM>, together with or separately from at least one compressible compensation element. In the case exemplified, the elastically deformable body <NUM> comprises, in addition to the compressible elements <NUM> and <NUM>, also the internal sealing element <NUM> and the lower supporting element <NUM>. Obviously, also in an embodiment of this type, in addition or as an alternative, there may be envisaged an overmoulding of the external sealing element <NUM>, as described with reference to the embodiment of <FIG>, or else the sealing elements <NUM> and/or the supporting element <NUM> can be moulded apart or overmoulded on the body <NUM> with another material.

In one embodiment, the transverse wall 2b of the body <NUM> is an intermediate wall of the duct <NUM>; i.e., it occupies an intermediate position between the two ends of the duct <NUM>. One such case is also exemplified in <FIG>. In this embodiment, the duct <NUM> comprises, downstream of the transverse wall 2b, a portion for housing the element <NUM>, clearly visible for example in <FIG>, where it is designated by 19a, in particular a hollow portion. With reference also to <FIG> and <FIG>, it may be clearly noted how a first part of the external compensation element <NUM> is located within the aforesaid portion 19a, here having a basically tubular shape, whereas a second part of the external compensation element <NUM> is located on the outside of the aforesaid portion 19a.

Preferably, during operation in the case of freezing of the fluid contained at least in the upper cavity portion C", the aforesaid first part of the external compensation element <NUM> is constrained peripherally by the portion 19a, in particular in order to prevent any radial deformation and/or for supporting more effectively the second part of the element <NUM>, which is preferably compressed or undergoes deformation only in an axial direction with respect to the axis of the duct <NUM>. The second part of the compensation element <NUM> is, instead, liable to compression or deformation in an axial and/or radial direction and/or according to different angles, in particular in order to compensate freezing and/or expansion of the fluid contained at least in part in the upper cavity portion C".

Preferably, the aforesaid second part of the external compensation element <NUM> extends at least in part also into the lower cavity portion C' in order to compensate also freezing or expansion of the fluid contained in a part of the aforesaid lower portion C', in the area delimited also by the sealing element <NUM>, where the fluid brings about compression and/or deformation of part of the compensation element <NUM> in a substantially radial direction.

The configuration of the device visible in <FIG>, which in particular envisages a sensor body <NUM> with an intermediate wall 5d of larger thickness as compared to the membrane 5a, also enables use of a sealing element <NUM> that operates at least in part also as compressible element or elastic compensation element. In this configuration, the axial expansion of the frozen fluid can be countered in one direction, upwards as viewed in <FIG>, by the aforesaid intermediate wall 5d of larger thickness, while it can be compensated in the opposite direction, downwards as viewed in <FIG>, by the sealing element <NUM>.

From <FIG> it may be noted how the housing portion 19a is located basically at the top of the projecting portion <NUM>. Once again from the aforesaid figure it may be noted how the transverse wall 2b preferentially presents a central passage <NUM> for the fluid and a plurality of peripheral passages <NUM>, which are to house respective connection portions 16a between the compensation elements <NUM> and <NUM>.

Advantageously, the sealing element <NUM> can be located at or in the proximity of the transverse wall 2b of the body <NUM> and/or of the connection portions 16a between the compensation elements <NUM> and <NUM>. Preferably, the sealing element <NUM> is located in the proximity of the area of variation of cross section between the lower cavity portion C' and the upper cavity portion C" and/or in the proximity of the housing portion 19a. Preferentially, and as may be noted in <FIG> and <FIG>, starting from the central passage <NUM> and proceeding outwards, there are encountered, in order, a portion of the transverse wall 2b, a portion 16a of the deformable element <NUM>, a portion of the housing 19a, a portion of the sealing element <NUM>, and the sensor body <NUM>.

Visible in isolation in <FIG> is an elastically deformable body <NUM> that can be used in a device according to the example of <FIG>. There may be identified the compensation elements <NUM> and <NUM>, the internal sealing element <NUM>, preferably having a substantially tubular or annular configuration, and the supporting element <NUM>, substantially like an annular cap. Preferably, the sealing element <NUM> is substantially frustoconical or cylindrical, with a shape and dimensions designed to fit in a sealed way and/or with elastic interference with the cavity portion C' of the sensor body <NUM>.

Also visible are some of the portions 16b, 16c that connect the element <NUM> to the supporting element <NUM> and/or to the sealing element <NUM> and that extend orthogonal or angled with respect to one another, in particular in part radially and in part axially with respect to the compensation element <NUM> (the portions 16b and/or 16c could possibly have a shape that is at least in part curved). These portions are within the passages <NUM>, 25a of <FIG>, thus guaranteeing, together with the portions 16a (<FIG>), precise positioning and/or fixing of the various portions of the deformable body <NUM>.

Consequently, according to an aspect, a deformable body <NUM> or at least one compensation element <NUM>, <NUM> is provided with positioning and/or fixing portions 16a, 16b, 16c, 16d. Preferably, there are provided at least one of the following: positioning and/or fixing elements 16a located in a first end area of the deformable body <NUM>; positioning and/or fixing elements 16b, 16c located in an intermediate area of the deformable body <NUM>; and positioning and/or fixing elements 16d (<FIG>), located in a second end area of the deformable body <NUM>. In particular, at least some positioning and/or fixing elements 16a, 16b, 16c, 16d are connected together and to at least one further positioning and/or fixing element, preferably of an annular or at least in part circular or curved shape, obtained on an outer profile and/or a seat of at least a part of the casing <NUM>, <NUM> of the device <NUM>. In the examples illustrated, the aforesaid at least one further positioning and/or fixing element comprises at least one of the elements <NUM>, <NUM> and <NUM>. Considering a structure similar to the one represented, the portions 16b, 16c could also converge in an external ring that does not operate as a seal, obtained with the sole purpose of connecting together the portions 16b, 16c, to get the moulding material to flow more effectively and/or to improve fixing.

<FIG> illustrate a possible moulding apparatus that can be used for producing the deformable body <NUM> of <FIG>. In this case, the moulding apparatus does not envisages movable sliders, but simply two parts of mould <NUM> and <NUM>, which define the respective impressions 30a and 31a for positioning the supporting body <NUM> and for definition of the outer profile of the deformable body <NUM>.

The aforesaid simplified structure of the mould <NUM>, <NUM>, without sliders, can be obtained by providing an element <NUM> that has a shape without any recess, such as a substantially frustoconical or cylindrical shape.

In <FIG>, the mould is closed, with the body <NUM> inside, whereas in <FIG> also the body <NUM> moulded on the body <NUM> is visible. A similar mould could be envisaged for overmoulding of just some elements or parts of the body <NUM>, such as the parts <NUM>, <NUM>, <NUM>, <NUM>, 16a, 16b, 16c.

<FIG> regard an embodiment of the invention according to claim <NUM>, basically distinguished by the use of a sensitive element with a sensor body that has a shape different from the embodiments described previously, such as a sensitive element that is substantially plane or is provided with a substantially plane membrane or lower surface, in particular a surface that is at least in part plane facing at least one of the ducts or passages <NUM>, <NUM>, 21b, <NUM> for inlet and/or detection of the fluid. Preferentially, the sensitive element defines both a flexible portion or membrane and a portion that is substantially rigid or rigidly fixed. In the example illustrated, a sensor body is provided made up of two parts <NUM>', <NUM>", which defines a cavity C delimited both peripherally and at the two axial ends. Preferably, the part <NUM>' of the body of the sensor is monolithic and/or substantially rigid, and the part <NUM>" is at least in part flexible in order to provide the deformable membrane 5a, where the part <NUM>" defines the aforesaid lower surface that is at least partially plane.

The cavity C may be closed, as in the example illustrated, and sensitive elements having this configuration are used for producing pressure sensors of an absolute type, in which case in the closed cavity C there is present a known positive or negative pressure, or else a vacuum. In other embodiments, the cavity C may be in fluid communication with the environment via a small hole defined in the body part <NUM>'.

In these configurations, the sensor body thus includes at least two body parts <NUM>', <NUM>" glued or welded together or rendered fixed with respect to one another, between which the cavity C is obtained. In one embodiment, such as the one illustrated in <FIG>, a part <NUM>', which is preferably monolithic, defines the cavity C, and another part <NUM>" defines the deformable membrane 5a at the centre. In other embodiments, the cavity C is delimited and/or defined in height by the thickness of the material that glues and/or renders fixed the two parts <NUM>', <NUM>".

The part <NUM>" is here substantially in the form of lamina and is rendered fixed (for example glued) with respect to the lower face of the body part <NUM>', preferably to a face on which a blind cavity opens or is provided.

In sensitive elements of this type, the depth of the cavity C (whether it is defined by the body <NUM>' or determined by the thickness of the annular gluing layer of the part <NUM>") is generally modest, so that the thickness of the body part <NUM>' on the side opposite to the membrane 5a can be such as to render rigid the body <NUM>' and/or such as to enable direct installation of electrical components and/or electronic components for control and/or calibration and/or processing. The deformation-detection element <NUM> may be at least in part associated to the inner side of the body part <NUM>" that forms the membrane 5a, and hence in a position protected from the fluid.

For instance, a sensitive element of this type, which can be used for the purposes of implementation of the invention (for absolute or relative pressure sensors), is the one described in <CIT>. Also in such an embodiment, consequently, the presence of a circuit on a corresponding support and/or corresponding spacer element is not strictly necessary. In a further example of embodiment, the sensing element <NUM> may comprise at least one electrode provided on one side of the body part <NUM>", i.e., the membrane 5a, preferably a side not exposed to the fluid or facing the cavity C. At least one second electrode may be provided on a corresponding side of the body <NUM>', in particular a side facing the cavity C.

As in previous embodiments, also in this case elastic contacts <NUM> may be used, which extend between portions of the terminals <NUM> inside the space <NUM>, and corresponding conductive pads or paths provided on the circuit <NUM>, in particular on the top face of the body part <NUM>'.

In the case exemplified in <FIG>, the deformable body <NUM> defines, not only the compensation elements <NUM> and <NUM>, but also the supporting element <NUM> that comprises at least some of the sealing characteristics described previously with reference to the element <NUM>. The element <NUM> provides a support and/or a seal of an axial type, between the upper face of the body <NUM> and the body part <NUM>" that forms the membrane 5a, specifically at an area of the part <NUM>" that surrounds the end of the cavity C (or in a position corresponding to an area of fixing or gluing between the part <NUM>' and the part <NUM>"). From <FIG> and <FIG> it may be appreciated how, in accordance with the invention, the membrane 5a is set between the cavity C or the sensor body <NUM>', <NUM>" and the external compensation element <NUM>.

The compensation element <NUM>, in embodiments of this type, constitutes a sort of disk, the lower surface of which preferentially rests completely on the upper face of the body <NUM>. Preferentially, moreover, the diameter of the element <NUM> is larger than the diameter of the internal compensation element <NUM>.

From the aforesaid figures, and in particular from <FIG>, it may likewise be noted how - according to the invention- the lower supporting and/or sealing element <NUM>, preferably overmoulded on the supporting body <NUM>, extends in this case - with respect to the upper face of the supporting body <NUM> - up to a height greater than the height of the compensation element <NUM>, which is also preferably overmoulded on the supporting body <NUM>. Thus, the collection chamber <NUM> is in any case delimited, within which the element <NUM> is located in a position generally facing and at a distance from the membrane 5a.

According to another aspect, the lower supporting and/or sealing element <NUM> operates at least in part as compensation element or compressible element. In particular, the element <NUM> is designed to undergo deformation or compression at least in part for compensating any possible expansion during freezing of the fluid contained in the collection chamber <NUM>, preferably compensating any expansion and/or undergoing compression or deformation in a direction substantially radial or orthogonal to the axis of the device <NUM>, and/or of the sensor body <NUM>', <NUM>", and/or of the duct <NUM>, <NUM>.

Also in solutions of this type there may be implemented characteristics already described with reference to the previous examples. For instance, also in this case, the duct <NUM> preferentially has a transverse wall 2a, substantially at the upper face of the body <NUM>, provided with a corresponding central axial passage <NUM> for the fluid, as is clearly visible in <FIG>, and one or more peripheral passages <NUM>, for the connection and/or fixing portions 16a between the compensation elements <NUM> and <NUM>. There are then also provided the passages <NUM>, in part transverse or radial and in part axial, which are to be occupied by the connection portions 16b, 16c between the element <NUM> and the sealing element <NUM>. Obviously, also in this case it is possible to form in a single piece - in particular via overmoulding - one or more of the compensation elements <NUM>, <NUM> and at least one from among the element <NUM>, the element <NUM>, and possibly the element <NUM>.

The example of <FIG> preferably refers to the case where the two bodies <NUM> and <NUM> block one another and/or block the sensor body <NUM>', <NUM>" in a predefined position, where in this case the element <NUM> operates prevalently as sealing element and/or radial compensation element. However, considering that preferably the bodies <NUM>, <NUM> are obtained via moulding of thermoplastic material (and are hence subject to variable dimensional tolerances due to the possible different shrinkage of material), in the case where blocking of the sensor body <NUM>', <NUM>" between the bodies <NUM>, <NUM> does not occur (for example, as a result of an unfavourable combination of the dimensional tolerances), then the supporting element <NUM> intervenes, which in any case elastically supports and pushes the sensor body <NUM>', <NUM>" in the direction designed to guarantee a good electrical connection between the electrical contacts <NUM>, <NUM>.

According to a possible variant, a configuration is provided in which the aforesaid blocking action between the two bodies <NUM> and <NUM> is not envisaged (for example, to prevent the risk of excessive compression on the sensor body in the case of unfavourable dimensional tolerances of the bodies <NUM>, <NUM>), envisaging beforehand a supporting and/or thrust function of the sensor body via the element <NUM>, also allowing a predefined relative compression thereof for the purposes of axial seal of the element <NUM> itself.

For the purposes of the aforesaid supporting and/or sealing functions, the element <NUM> is preferably overmoulded at least in part on a corresponding portion of the body <NUM> that is designed to guarantee an appropriate support in an axial direction, such as the step designated by 2c in <FIG>.

Visible in isolation in <FIG> is the deformable body <NUM> of <FIG>. Also in this case, the compensation elements <NUM> and <NUM> of the body <NUM> may be clearly identified, as well as the element <NUM>, which here has a generally annular configuration and is connected to the element <NUM> via the portions 16b, 16c. Also partially visible are the connection portions 16a between the elements <NUM> and <NUM>.

<FIG> illustrates a variant embodiment according to claim <NUM> of the device of <FIG>, whereby the device <NUM> comprises a deformable body <NUM> with two compensation elements <NUM> and <NUM> joined together, to form a single body. In this embodiment, there is in any case provided a lower supporting and/or sealing element that is not configured as overmoulded part and is not fixed with respect to the body <NUM>, but is constituted by an annular element <NUM>' set between a peripheral portion of the membrane 5a, or else radially external to the area occupied by the cavity C of the sensor body <NUM>'; <NUM>", and the top face of the supporting body <NUM>.

To the variant embodiment of <FIG> there may be applied characteristics already described with reference to the embodiment of <FIG>, also in this case there being envisaged at least one compensation element <NUM>, <NUM> overmoulded on a part <NUM> of the casing body of the device <NUM>. At least one further lower supporting and/or sealing element <NUM>' is preferably present, configured as part separate from at the least one compensation element, for example mounted or overmoulded on the body <NUM>, in particular made of a material different from that of the at least one compensation element.

In embodiments of the type illustrated in <FIG> and <FIG> (and in <FIG>, described hereinafter), it is preferable for the compensation element to present one or more of the following characteristics:.

Practical tests conducted by the present applicant have made it possible to ascertain that, for the purposes of production of at least part of the elements overmoulded on a part of the device <NUM> and/or on the supporting body <NUM> (whether they are configured as single elements or as elements defined at least in part by a single elastically deformable body), it is particularly advantageous to use materials having a bulk modulus comprised between <NUM> MPa and <NUM> GPa, preferably between <NUM> MPa and <NUM> MPa, very preferably between <NUM> MPa and <NUM> MPa, in particular between <NUM> MPa and <NUM> MPa.

According to a further aspect, for the purposes of production of at least part of the elements overmoulded on a part of the device <NUM> and/or on the supporting body <NUM> (whether they are configured as single elements or as elements defined at least in part by a single elastically deformable body), it is particularly advantageous to use materials having a hardness comprised between <NUM> Shore A and <NUM> Shore A, preferably between <NUM> Shore A and <NUM> Shore A, very preferably between <NUM> Shore A and <NUM> Shore A.

Advantageously, two different materials may be used, which may possibly be overmoulded in different steps on a part of the device <NUM>, such as a material having a hardness comprised between <NUM> Shore A and <NUM> Shore A, preferably between <NUM> Shore A and <NUM> Shore A, very preferably between <NUM> Shore A and <NUM> Shore A, and a material having a hardness comprised between <NUM> Shore A and <NUM> Shore A, preferably between <NUM> Shore A and <NUM> Shore A, very preferably between <NUM> Shore A and <NUM> Shore A.

Further practical tests conducted by the present applicant have made it possible to ascertain that, for the purposes of production of elements overmoulded on a part of the device <NUM> and/or on the supporting body <NUM> (whether they are configured as single elements or as elements defined at least in part by a single elastically deformable body), it is preferable to use mouldable or injectable materials the molecules of which, in particular after the corresponding overmoulding, assume a structure or chain that is at least substantially helical and/or with spaces between the molecules and low intermolecular forces between the chains. The purpose of this is, in particular, to obtain a high compressibility of the material and/or of the overmoulded compensation element, preferably at very low temperatures, such as the temperatures at which there arise conditions of freezing of the liquid whose expansion is to be compensated. The aforesaid substantially helical structure is preferably obtained at least in part with siloxane bonds or bonds of the Si-O-Si type of the overmoulding material.

According to an aspect, it is particularly advantageous to obtain compressible elements <NUM>, <NUM>, via the use of a silicone material, such as for example a silicone elastomer or a liquid silicone rubber (LSR) or fluoro liquid silicone rubber (FLSR), preferably a bicomponent material or a bicomponent silicone, in particular of the type that can be overmoulded by injection.

Preferably, the material of the part of device <NUM> and/or of the supporting body <NUM> on which the aforesaid material is overmoulded is a polymer or a copolymer or a thermoplastic material, such as a polyamide (PA) or a polyphthalamide (PPA), as an alternative or in combination it being possible to use a metal and/or ceramic material.

<FIG> are schematic illustrations of possible alternative embodiments of mouldable bodies that can be used for the purposes of implementation of the invention, which integrate one or more of the functional elements described (internal compensation element, external compensation element, internal sealing element, external sealing element, lower supporting element).

<FIG> illustrates the case where a body <NUM> is at least partially hollow, i.e., filled at least in part with air or with a gas, and can be obtained according to appropriate moulding techniques. In one embodiment, the overmoulding is carried out by inserting or injecting an amount of material A less than the volume of the impression for the shape to be obtained (this impression being defined in part by the mould and in part by a portion of a body <NUM> of the device <NUM>), and subsequently or simultaneously by injecting air or gas or else by rotating the mould in such a way that the material is distributed over the surfaces of the aforesaid impression, substantially forming the external surface of the deformable body <NUM>, then letting the material cool and/or solidify. The body <NUM> is then taken out of the mould with the hollow body <NUM> overmoulded thereon. According to the example of <FIG>, the cavity of the body <NUM> extends into the internal compensation element <NUM>, the external compensation element <NUM>, the internal sealing element <NUM> and the supporting element <NUM>.

<FIG> regards a version similar to that of <FIG> but in which the body <NUM> is obtained with a first material A, in particular designed to provide an external surface of the body <NUM>, preferably an elastic material or an elastomer, and with a second material B, in particular designed to fill the cavity inside the body <NUM> or provide the internal volume of the body <NUM>, preferably a material of an expanded type, such as a material designed to create a foamed structure, i.e., with open or closed cells.

The body <NUM> according to <FIG> may be obtained at least in part according to the modalities described with reference to the example of <FIG>, at least to form the external wall of the body <NUM> with the material A. For instance, overmoulding is carried out by injecting an amount of material A less than the volume of the impression of the shape to be obtained (impression defined in part by the mould and in part by the body <NUM>), subsequently or simultaneously injecting the material B, preferably a bicomponent material mixed during injection and designed to expand so as to form the internal part of the body <NUM>, which preferably has a foamed or cell structure. Next, the materials are left to cool and/or solidify, and the body <NUM> is then taken out of the mould, with the body <NUM> overmoulded thereon, provided on the outside with a full wall without cells and on the inside with a foamed or cell structure.

<FIG> is a version in part similar to that of <FIG>, which is a schematic representation of the case of a body <NUM> that is in part hollow and in part full. In the example illustrated, a substantial portion of the compensation element <NUM> is hollow, whereas the compensation element <NUM>, the internal sealing element <NUM>, and the supporting element <NUM> are formed full. This solution may be obtained via overmoulding of just one material. Overmoulding can be obtained according to what is described in the process represented in <FIG>, by injecting, however, a larger amount of material A, which can be distributed using the aforementioned blowing or spinning techniques, possibly allowing a part of the material to pour and/or settle by gravity into the areas in which the full parts <NUM>, <NUM>, <NUM> are to be obtained (for example, with the body <NUM> and the body <NUM> in the mould in a position rotated through <NUM>° with respect to the position illustrated in <FIG>).

<FIG> is a schematic representation of the case of a body <NUM> in which a substantial portion of the internal compensation element is at least in part made of an expanded and/or cell-foam material B, whereas the remaining part is made of full material A. Consequently, in such a configuration, on the body <NUM> an overmoulding of two different materials is carried out simultaneously or in two distinct steps, for example, by injecting simultaneously or separately a full elastomeric or silicone material and a bicomponent and/or expanding material on at least part of the supporting body <NUM> (or some other part of the device <NUM>) in order to obtain the body <NUM>. In the case of execution in two distinct steps, appropriate parts of mould are provided, designed to form the various intermediate shapes of the body <NUM>.

<FIG> is a schematic representation of the case of a deformable body <NUM> in which the compensation elements <NUM>, <NUM> are made of a first material B, whereas the internal sealing element <NUM> and the supporting element <NUM> are made of a second material A overmoulded on the first material B, or vice versa. It will consequently be appreciated that the body <NUM> does not necessarily have to be made of just one material in a single moulding operation, but for its formation overmoulding of different materials may be envisaged.

<FIG> is a schematic representation of a variant similar to the one described with reference to <FIG>, in which the internal compensation elements <NUM> and external compensation elements <NUM> are obtained with an expanded or cell-foam material B, whereas the internal sealing elements <NUM> and the supporting element <NUM> are obtained with a full material A.

Finally, <FIG> illustrates a version similar to that of <FIG>, i.e., one which uses two full materials overmoulded, preferably at least in part on one another, to obtain the body <NUM>, but where the overmoulded part that provides the internal sealing element <NUM> and the supporting element <NUM> also constitutes the external sealing element <NUM>'.

From <FIG> it may be noted how, regardless of the type and/or number of materials used for obtaining the body <NUM>, the external sealing element <NUM>' can be joined via corresponding connection portions 16d to the supporting element <NUM> instead of to the compensation element <NUM>.

In the case illustrated, for example, provided in the body <NUM> is at least one passage - radial or transverse with respect to the duct <NUM> - that has a respective stretch 25b that extends downwards, for housing a corresponding connection portion 16d, as far as the hydraulic-connector portion 2a where the external sealing element <NUM>' is formed. Obviously, types of passages and/or of connection of this sort between the sealing element <NUM>' and the sealing and/or supporting element <NUM> may be implemented also in the embodiments described previously.

According to an aspect, at least part of an elastically deformable body, such as at least one from among a compressible compensation element, an internal sealing element and a lower supporting and/or sealing element is configured as overmoulded at least in part on the sensor body of the device according to the invention, preferably on a sensor body at least in part made of ceramic or metal material. The sensor body may possibly be at least in part moulded, preferably via an appropriate mould that enables injection and/or forming of an at least in part ceramic or metal material. Following upon or during the step of moulding of the sensor body there can be overmoulded thereon or co-moulded therewith at least in part the elastically deformable body that defines one or more from among at least one compensation element, one internal sealing element and one lower supporting and/or sealing element.

The fact that one or more of the aforesaid elements are overmoulded on the sensor body considerably facilitates production of the device, also in this case reducing the operations and apparatuses necessary for its assemblage and the corresponding times, as well as ensuring a high precision of positioning between the parts in question.

Preferably, the material of the overmoulded or co-moulded elements has characteristics such as to adhere or adapt better to the sensor body, in particular such as to penetrate into the possible surface micro-roughnesses or porosities of the sensor body during moulding, thus improving the corresponding seal, for example with respect to a seal obtained merely by compression of a sealing element produced separately and pressed elastically against the sensor body.

In one or more embodiments, just one of the aforesaid elements is overmoulded on the sensor body, whereas in other embodiments two or more of the aforesaid elements are overmoulded on the sensor body. Two or more of the aforesaid elements may also be made of a single piece, i.e., be joined together to form a single elastically deformable body. Very advantageously, one or more from among the internal sealing element, the supporting element, and the external sealing element may be overmoulded on the sensor body together with a compressible compensation element.

For this purpose, <FIG> represent schematically some possible embodiments, according to which one or more elements selected from among a compensation element, a sealing element and a supporting element is/are overmoulded on a sensor body.

In the case of <FIG>, a sensor body <NUM> is shown, preferably of a monolithic type, for example made of ceramic or metal material, the cavity of which is divided into a lower portion C', which is wider or of larger diameter, and an upper portion C", which is narrower or of smaller diameter, as in the case of the embodiments illustrated in <FIG>. In this embodiment, overmoulded on the body <NUM> are an external compensation element <NUM>, an internal radial sealing element <NUM>, and a lower supporting and/or sealing element <NUM>, configured as parts distinct from one another, i.e., as distinct elastically deformable bodies. The elements <NUM> and <NUM> are both overmoulded in the cavity of the sensor body <NUM>, in particular on its peripheral surface and here have an approximately tubular or annular shape. In the example, the elements <NUM> and <NUM> are located within the upper cavity portion C" and lower cavity portion C', respectively. The lower supporting and/or sealing element <NUM> is instead overmoulded on the body <NUM> on its plane lower surface, specifically in an area thereof that circumscribes the opening of the blind cavity C', C", and here has a substantially annular shape.

<FIG> illustrates the case of overmoulding on the sensor body <NUM> of a single deformable body <NUM>', which defines an external compensation element <NUM>, an internal sealing element <NUM> and a supporting element <NUM>. Also in this case, the elements <NUM> and <NUM>, which have an approximately tubular or annular shape, are located within the portions C" and C', respectively, of the blind cavity of the sensor body <NUM>, whereas the element <NUM>, here substantially shaped like an annular washer, extends over the plane lower surface of the body <NUM>.

<FIG> illustrates a variant according to which the deformable body <NUM>' overmoulded on the body <NUM> defines one or more functional elements having parts in relief or recessed parts. In particular, in the example illustrated,.

<FIG> is a schematic illustration of a possible moulding apparatus that can be used for obtaining the deformable body <NUM>' of <FIG>. Also in this case, as may be noted, a part of mould <NUM> is provided, defining a corresponding impression 40a for positioning the sensor body <NUM> previously formed apart or directly in the mould, and a second part of mould <NUM>, the impression 41a of which is shaped so as to define at least part of the body <NUM>', such as its profile not in contact with surfaces of the body <NUM>. In the example of <FIG>, the very elasticity of the body <NUM>' renders possible the deformation of the undercut relief that constitutes the intermediate narrowing <NUM>' of the compensation element <NUM>, in order to enable extraction of the part of mould <NUM> (it being possible, however, to envisage other movable parts or sliders in the mould, designed to enable extraction, in particular in the case of more complex shapes of the body <NUM>').

<FIG> illustrates the assembled condition of a sensor body <NUM>, with the deformable body <NUM>' overmoulded thereon of the type illustrated in <FIG>. In the example, the body <NUM> is fitted on the projecting portion <NUM> of the supporting body <NUM>, which in this case does not comprise overmoulded parts and does not need internal or surface passages for housing connection portions of the deformable body. As may be noted, in the assembled condition, the outer profile of the body <NUM>' is in the proximity or in contact with corresponding surfaces of the body <NUM> in order to perform the necessary functions of compensation (element <NUM>), radial seal (element <NUM>) and axial seal and/or elastic support (element <NUM>).

Moreover visible in the example illustrated is a second elastically deformable body, designated by <NUM>", which provides an internal compensation element <NUM> inserted in or overmoulded on a respective portion of the duct <NUM> of the body <NUM>. In this case, another stretch of the duct <NUM> - which traverses an intermediate portion of the body <NUM> and its projecting portion <NUM> - forms a substantial part of the passageway <NUM>. In this case, it is not necessary for the duct <NUM> to have the transverse wall 2b. According to a variant (not represented), the compensation element <NUM> could be overmoulded on the supporting body <NUM> instead of on the sensor body <NUM>. There would hence be obtained a configuration where at least one of the compensation elements <NUM>, <NUM> is overmoulded on the supporting body <NUM> and at least one of the sealing element <NUM> and the supporting element <NUM> is overmoulded on the sensor body <NUM>. Of course, the external sealing element <NUM> of <FIG> may be replaced by a sealing element of the type previously designated by <NUM>', formed in a single body with the element <NUM>, in particular via overmoulding on the body <NUM>.

According to a characteristic, which may apply, for example, to the embodiment not forming part of the invention of <FIG> and/or to the aforesaid variant not represented, the device comprises elastically deformable elements, such as at least two from among an internal compensation element <NUM>, an external compensation element <NUM>, an internal sealing element <NUM>, a lower element <NUM> and an external sealing element <NUM>' overmoulded separately or jointly on the sensor body <NUM> and on the supporting body <NUM> or on another part of the device <NUM>.

<FIG> refers to an embodiment according to claim <NUM> similar to the one already described previously in relation to <FIG>, whereby the cavity C of a sensor body formed in two parts is determined by the thickness of a layer of gluing material G, used for fixing the part <NUM>" defining the membrane 5a to the part <NUM>', which in this case has a substantially plane lower face. Preferentially, the gluing material G has a glass filler that, during the gluing step carried out hot, melts to fix the part <NUM>" and the part <NUM>' together, keeping the former at a certain distance from the latter. In this way, the layer G forms a sort of substantially cylindrical peripheral wall of the cavity C, determining the height of the latter. In the case exemplified, an elastically deformable body <NUM> is obtained, which forms two compensation elements <NUM> and <NUM>. A supporting and/or lower sealing element <NUM>' is then provided, configured as distinct part mounted on the body <NUM> or overmoulded thereon. The embodiment is hence similar to that of <FIG>, but obviously a sensor body <NUM>', <NUM>" of the type shown in <FIG> can be used in the device illustrated in <FIG>.

In the versions appearing in <FIG>, the two casing parts <NUM> and <NUM> may be configured for blocking the sensor body <NUM> in position. In the case where this blocking does not occur, for example by an unfavourable combination of the dimensional tolerances, the element <NUM>' intervenes, which in any case supports and pushes the sensor body <NUM> towards the elastic contacts <NUM>, <NUM>. The embodiment of <FIG> regards a casing <NUM>, <NUM> that envisages, in any case, the aforesaid elastic support by the element <NUM>', for example, to prevent the risk of any excessive compression on the sensor body <NUM>. As will appear evident to the person skilled in the art, various characteristics described with reference to <FIG> and <FIG> may be applied also to the case of the device of <FIG>, and vice versa.

<FIG> illustrates an embodiment of a device <NUM> falling outside the present invention, of a conception similar to that of the device of <FIG>, but in which only the compensation elements <NUM> and <NUM> are overmoulded on the body <NUM>, in particular to form a single elastically deformable body <NUM>. The sealing element <NUM>', and the supporting element <NUM>' are instead configured as parts independent of the compensation elements <NUM> and <NUM> and mounted on the body <NUM>. Of course, also the external sealing element <NUM> of <FIG> may be replaced by a sealing element of the type previously designated by <NUM>', formed in a single body with the element <NUM>, in particular via overmoulding on the body <NUM>.

As will appear evident to the person skilled in the art, various characteristics described with reference to <FIG> may apply also to the case of the device of <FIG>. With reference also to <FIG>, and as already mentioned with reference to <FIG>, the part of the external compensation element <NUM> located on the outside of the corresponding housing 19a extends at least in part into the lower cavity portion C'. This enables compensation also of freezing or expansion of the fluid contained in a part of the aforesaid lower portion C', in the area delimited also by the sealing element <NUM>', where the fluid brings about compression and/or deformation in a substantially radial direction of part of the compensation element <NUM>. Preferably, the sealing element <NUM>' operates at least in part also as compensation element. The axial expansion of the frozen fluid can be countered in one direction, upwards as viewed in <FIG>, by the intermediate wall 5d of larger thickness of the sensor body <NUM>, whereas it can be compensated in the opposite direction, downwards as viewed in <FIG>, by the sealing element <NUM>. In <FIG>, the small arrows appearing within the cavity C', C" of the sensor body <NUM> represent schematically lines of force of the thrust of the frozen liquid between the sensor body <NUM>, the compensation element <NUM>, and the sealing element <NUM>.

Illustrated in <FIG> is a further embodiment according to claim <NUM>, according to which the device has a sensor body that includes at least two body parts <NUM>', <NUM>", which are rendered fixed with respect to one another and obtained between which is a cavity C. The sensor body may be of the type illustrated with reference to <FIG>, or else of the type illustrated in <FIG>, for example with a sensing system of a piezoresistive or capacitive type. According to an aspect, applied to or overmoulded on the sensor body <NUM>', <NUM>" are at least one of an element <NUM> that performs supporting and/or sealing and/or compensation functions and an element <NUM>" that performs positioning and/or centring functions. The element <NUM> is preferentially overmoulded on the body part <NUM>" or on the membrane 5a, and the element <NUM>" is preferentially overmoulded on the outer profile or perimeter of the sensor body <NUM>', <NUM>". In a preferred version, the elements <NUM> and <NUM>" are made of a single piece, in particular overmoulded on the sensor body, to form an elastically deformable body therewith.

The element <NUM>" overmoulded on the outer profile of the sensor body has a substantially annular or tubular shape, in particular to ensure positioning and/or centring (and radial seal) with respect to a perimetral wall 2d of the supporting body <NUM>, preferably a wall 2d of the body <NUM> having a substantially circular or cylindrical shape.

According to an aspect, provision of an element <NUM>" on the outer perimeter of the sensor body enables an optimal radial seal that is not affected by variations in the position and/or axial compression of the sensor body; i.e., it is not affected by dimensional tolerances or variations of the items belonging to the casing of the device, which could determine non-precise axial positioning of the sensor body. From <FIG> it may be noted how part of the overmoulding material also penetrates into the peripheral gap between the body parts <NUM>', <NUM>" and the layer of adhesive G, thus improving fixing of at least one of the elements <NUM> and <NUM>' to the sensor body <NUM>', <NUM>", or fixing of the single piece that defines them.

In the embodiment of <FIG>, at least one compensation element is preferentially associated to the body part <NUM>, in particular overmoulded thereon. In the case exemplified, there is hence provided a further elastically deformable body <NUM> that defines two compensation elements <NUM> and <NUM>.

According to an aspect that may apply at least to the embodiments illustrated in <FIG> and <FIG>, both the sensor body <NUM> or <NUM>', <NUM>" and the casing <NUM>, <NUM> comprise respective overmoulded elastically deformable bodies.

<FIG> refer to a further embodiment, in which a preferably monolithic sensor body <NUM> is provided, to which a circuit support <NUM>' is rendered fixed, for example via gluing. The circuit support <NUM>' is rendered fixed in a peripheral area of the upper face of the sensor body <NUM>, in a position such that it is raised with respect to the membrane 5a, in order to define a space S in which the membrane itself can bend upwards. The height of the space S is preferably defined by the thickness of the gluing material G'. In addition or as an alternative, a purposely designed recess may be provided in the lower face of the circuit support <NUM>'. For such an implementation, it is also possible to use a sensor body <NUM> of the type illustrated in <FIG>, <FIG>, and <FIG>.

<FIG> moreover illustrates a further characteristic, whereby overmoulded on the closing body <NUM> is an elastically deformable body that defines a sealing and/or supporting element <NUM>. In the example, the element <NUM>, which has a generally annular configuration, co-operates with the circuit support <NUM>', it being possible, in addition or as an alternative, for it to co-operate with the sensor body <NUM> in order to guarantee positioning, and/or sealing, and/or upper elastic support of the ensemble formed by the sensor body <NUM> and by the circuit support <NUM>'. An element of the type designated by <NUM> may of course be used also in other embodiments described herein.

In the case of <FIG> two compensation elements <NUM>' and <NUM>' are moreover provided, which are mounted on the body <NUM> or overmoulded thereon and are here configured as distinct elements. In this embodiment not forming part of the invention, the external compensation element <NUM>' is mounted or overmoulded in a region corresponding to an upper tubular projection of the body <NUM> (not indicated), which forms a terminal stretch of the duct <NUM> or of the passageway <NUM>. There are then also provided in this case an internal sealing element <NUM>' and a supporting element <NUM>', configured as distinct elements. It will be appreciated, however, that characteristics described in various previous embodiments in relation to one or more of the elements or bodies <NUM>, <NUM>', <NUM>, <NUM>', <NUM>, <NUM>', <NUM>, <NUM>, <NUM>, <NUM>' may apply also to the case of the embodiment not forming part of the invention of <FIG>.

Previously solutions of elastically deformable bodies <NUM>, <NUM>' have been exemplified that include an internal compensation element <NUM>, an external compensation element <NUM>, an internal sealing element <NUM>, a supporting element <NUM>, and possibly an external sealing element <NUM>'. As has already been mentioned, however, the possible combinations of embodiment are innumerable, including provision of an elastically deformable body that comprises just one compensation element (such as the body <NUM>" of <FIG>), with possibly joined thereto one or more of the other functional elements referred to (for example, an external sealing element <NUM>'), or once again provision in a single body of an internal sealing element, a supporting element, and possibly an external sealing element, separately from a compensation element.

The apparatuses of <FIG>, <FIG> and <FIG>, have been exemplified in combination with the embodiments of <FIG>, <FIG>, and <FIG>, respectively, but it is clear that apparatuses of the same type may be used for producing various other embodiments described herein. Furthermore, the apparatuses referred to have been described principally in combination with processes of overmoulding in a strict sense, but as has been said, the invention may be implemented also using co-moulding processes, employing appropriate techniques and apparatuses, for example of the type described or of some other type of a conception in itself clear to the person skilled in the art.

Emerging clearly from the foregoing description are the characteristics and advantages of the present invention, principally represented by the ease of production of the sensor device, this being faster, more economically advantageous, and precise than in the case of devices according to the prior art. The type of embodiment proposed likewise enables an increase in the certainty of positioning of one or more functional elements of the device (internal compensation element, external compensation element, internal sealing element, lower supporting element, external sealing element, centring element, top supporting element) also during the service life of the device.

It is clear that numerous variations to the devices described by way of example are possible for the person skilled in the branch, without thereby departing from the scope of the invention. As already mentioned, for the purposes of production of the aforesaid further variants, one or more of the characteristics described previously with reference to different embodiments may be combined in any adequate way.

As has been mentioned, what has been described with reference to overmoulding regarding the body part <NUM> may apply to other parts of the housing or supporting structure of the device <NUM> or its inserts, such as the spacer <NUM> and/or the support of the circuit <NUM>.

Claim 1:
A pressure-sensor device (<NUM>) having:
- a component sensitive to pressure, comprising a sensor body (<NUM>', <NUM>") with a cavity (C), an elastically deformable membrane part (5a) that closes the cavity at an end thereof, and at least one detection element (<NUM>) for detecting a deformation of the membrane part (5a);
- a structure (<NUM>, <NUM>) for housing or supporting the pressure-sensitive component, having a passageway (<NUM>) for a fluid the pressure of which is to be detected, the housing or supporting structure (<NUM>, <NUM>) comprising a supporting body (<NUM>) with respect to which the sensor body (<NUM>', <NUM>") is mounted in such a way that its membrane part (5a) is exposed to fluid coming out of the passageway (<NUM>), the supporting body (<NUM>) having a hydraulic-connection portion (2a) and a duct (<NUM>) that extends from the hydraulic-connection portion (2a);
- at least one elastically deformable body (<NUM>), formed with one or more elastically deformable or compressible materials,
- a sealing and/or supporting element (<NUM>; <NUM>'), which is set between the supporting body (<NUM>) and the sensor body (<NUM>', <NUM>"), to define with them a chamber for collecting the fluid (<NUM>),
wherein the elastically deformable body (<NUM>) defines at least one external compensation element (<NUM>), configured for compensating any possible variations in volume of the fluid, which is in a position generally facing or close to the membrane part (5a) of the sensor body (<NUM>', <NUM>") and extends at least in part on the outside of the duct (<NUM>) of the supporting body (<NUM>);
the pressure-sensor device (<NUM>) being characterized in that:
- a portion of the membrane part (5a) of the sensor body (<NUM>', <NUM>") extends in a position between the cavity (C) thereof and the at least one external compensation element (<NUM>),
- the sealing and/or supporting element (<NUM>; <NUM>') extends, with respect to an upper face of the supporting body (<NUM>), to a greater height than the external compensation element (<NUM>); and
- the external compensation element (<NUM>) is set at a distance from the membrane part (5a) and is positioned in an area circumscribed by the sealing and/or supporting element (<NUM>; <NUM>').