DESCRIPTION

TECHNICAL FIELD

The present invention relates to the field of meter apparatuses for fuel gas, such as methane or the like, according to the preamble of claim 1.

PRIOR ART

Fuel gas meter apparatuses comprising a measuring compartment and a compartment housing the electronic components are known in the prior art.

The measuring compartment is closed to the outside and at least two pipes lead thereto, one for supplying and one for discharging a gas.

In the measuring compartment there are provided one or more sensors for measuring the supplied amount of gas, for example by means of a measurement of the volumetric type, of the flow rate type or the like.

Such sensors transmit the data detected in the measuring compartment to an electronic control unit housed into a separate compartment housing the electronic components, so as to avoid a spark generated by a possible malfunction thereof triggering an explosion of the gas that flows in the measuring compartment.

To this end the two compartments (the measuring one and the electronics housing one) are physically adjacent to each other but they are separated by a partition through which however the connectors transmitting the signals at least from the sensor to the control unit pass.

To this end one or more gaskets are arranged around the connectors, which prevent the gas from passing through the partition and from collecting in the electronics housing compartment.

A common problem of these meter apparatuses (or meters) is related to the fact that the airtight seal guaranteed by the gasket at the area where the connectors pass tends to decrease over time, both due to the obsolescence of the material of the gasket and due to the effect of possible thermal deformation cycles.

A decrease in the airtight seal causes gas to pass from the measuring compartment to the one housing the electronics, with the risks mentioned above. Currently in order to overcome such drawback a periodical inspection of the gasket intactness and its preventive replacement are scheduled.

A further drawback that is found, also with the seal in the intact condition, relates to the passage of the gas in the compartment housing the electronics due to osmotic phenomena in the rubber of the gasket.

In this case the scheduled replacement or the inspection of the gasket are useless, actually the meter being subjected to a relatively high risk of explosion, that is even more serious by the fact that the electronics housing compartment is immediately adjacent to the measuring one, which contains considerable amounts of gas and which is connected to the supply network and to the user.

OBJECTS AND SUMMARY OF THE INVENTION

The object of the present invention is to overcome the prior art drawbacks.

Particularly the object of the present invention is to provide a fuel gas meter apparatus wherein should the gas escape in the area of the connectors of the measuring compartment it would not cause the adjacent electronics housing compartment to be filled.

Another object of the present invention is to provide a fuel gas meter apparatus inherently safe, wherein a possible crack in the gasket or an osmotic phenomenon of the gas therein do not causes the electronics housing compartment to be filled.

The idea at the base of the present invention is to provide a fuel gas meter apparatus comprising a single case incorporating a measuring compartment and one for the electronics which are separated by a hollow space which is passed through by a physical line for transmitting data from a sensor arranged in the measuring compartment to an electronic control unit arranged in the electronics compartment, said hollow space being in fluid communication with an environment outside the case.

Thus prior art drawbacks are overcome, since in the event of a possible gas leakage from the measuring compartment, the gas flows in the hollow space, and from here towards the external environment, preventing the electronics compartment from being filled.

Moreover thus possible drawbacks relating to the generation of osmotic phenomena in the rubber of the gasket of the physical line transmitting data from the sensor to the control unit are also overcome: in the event of a possible passage of gas through such gasket, the gas again flows in the hollow space and from here to the outside, with the same advantages mentioned above.

Further advantageous characteristics of the present invention are the object of the annexed claims that are an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below with reference to non-limiting examples, provided by way of example and not as a limitation in the annexed drawings. These drawings show different aspects and embodiments of the present invention and, where appropriate, reference numerals showing like structures, components, materials and/ or elements in different figures are denoted by like reference numerals.

Fig. 1 is a sectional view of a base arrangement of a meter apparatus according to the present invention;

figs. 2 and 3 are sectional views of the measuring compartment and of the electronics housing compartment of the meter apparatus of the previous figure;

fig. 4 is a perspective view of the meter apparatus of the previous figures;

figs. 5 and 6 are two moments in the manufacturing of the meter apparatus of the previous figures;

figs. 7 and 8 are details of the meter apparatus of the present invention;

fig.9 is another detail of the meter apparatus of the present invention;

fig.lO is a detail of an electrical connection of the meter apparatus of the invention; fig.ll is another moment in the manufacturing of the meter apparatus of the previous figures;

figs. 12 and 13 are details of the gas escape from a hollow space of the meter apparatus of the invention; figs. 14 and 15 are two moments in the manufacturing of a variant of the meter apparatus of the present invention;

figs. 16 and 17 are details of the variant of figs. 14 and 15.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible of various modifications and alternative forms, some relevant described embodiments are shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific embodiment disclosed, but, on the contrary, the intention of the invention is to cover all modifications, alternative forms, and equivalents falling within the scope of the invention as defined in the claims.

The use of "for example", "etc.", "or" indicates non-exclusive alternatives without limitation unless otherwise noted. The use of "including" means "including, but not limited to," unless otherwise noted.

Figures 1 to 3 show a base arrangement of a fuel gas meter apparatus according to the present invention, generally denoted by reference 1.

It comprises an outer case 2, incorporating all the functional parts of the meter apparatus 1.

More in detail the outer case 2 comprises a measuring compartment 3 in fluid communication with at least one inlet pipe 10 and an outlet pipe 11 for a fuel gas.

Typically the inlet pipe 10 is connected to a fuel gas supply network, while the outlet pipe 11 is connected to an appliance that can be supplied by said fuel gas (e.g. a cooking appliance, a boiler or the like).

The measuring compartment 3 inside is provided with at least one sensor 4 for measuring a quantity indicative of a volume of said fuel gas supplied by said meter apparatus 1.

In the figure the sensor 4 is particularly shown as a simple black box, since it can be of different types, depending on preferences, without this affecting the present invention: especially the sensor 4 can be of the mass type, ultrasound or ionization electronic type; these types of sensor are known in se and therefore no further reference is made thereto.

Anyway the sensor 4 detects data that directly or indirectly indicate the gas volume supplied by the pipe 11 and it transmits them to an electronic control unit 6 for being later processed/ recorded.

Said electronic control unit 6 detecting the data sent by the sensor 4 is placed in the electronics housing compartment 5.

Even in this case the type of electronic control unit can change depending on implementation needs, without this substantially affecting the present invention. As it is noted the sensor 4 and the electronic control unit 6 are connected with each other by a data transmission physical line 7.

The term "data transmission physical line" here means a line providing at least one, preferably several solid connectors, such as plugs, rigid connections, wires or the like; thus possible wireless (with no wire), radio, bluetooth connections or the like are excluded which otherwise would involve the insertion in the measuring compartment 3 of a transmission apparatus that needs to be electrically supplied, with adverse consequences as regards safety (fuel gas is present at very high amounts in the measuring compartment 3 and therefore the presence of any electric power supply is not advisable so as to avoid triggering unwanted explosions in case of an infiltration of oxygen or air and to avoid the ratio to reach the stoichiometric ratio).

According to the teachings provided herein the case 2 further comprises a hollow space 8 that, at least partially, separates the measuring compartment 3 from the electronics housing compartment 5, and which is placed at the data transmission physical line 7; in other words, it can be noted from annexed figures 1-3 how the data transmission physical line 7 (that in this example comprises a male/female socket with rigid connectors) passes through said hollow space 8.

The latter is in fluid communication with an environment outside the meter apparatus 1, for example by means of suitable passages or channels 80 (that will be described in details below), such that should the gas escape from the measuring compartment 3 at the data transmission physical line 7 it is conveyed to the outside, thus advantageously preventing it both from concentrating in the hollow space and from spreading in the electronics housing compartment 5.

To this end it is of use to make reference to figs. 12 and 13 wherein an arrow denotes a possible escape path P for the gas possibly collected in the hollow space.

In the embodiment shown in these figures by way of example, the inlet pipe 10 and the outlet one 11 comprise an end mouth that is tightly connected to the measuring compartment 3 (as it can be seen in figure 13 only for the pipe 10, similar to pipe 11). In order to allow the gas possibly collected in the hollow space 8 to escape, channels 80 are provided which put in fluid communication the hollow space 8 with the environment outside the meter apparatus 1.

Such channels 80, in this example, are obtained in the material of the case 2B, especially at the case wall 2B bearing the mouths of the pipes 10 and 11 and they extend from the hollow space 8 to the outside, ending in a position adjacent to the mouth.

It has to be noted now that such channels 80 instead of being obtained by suitable passages and recesses in the material of the case 2B they could be likewise obtained by means of tubes applied to the meter apparatus 1 or by other solutions that provide the combination of channels obtained and applied on the meter apparatus 1; it is also clear that the solution shown herein has to be intended as a mere embodiment, since the person skilled in the art can provide equivalent solutions, that for example provide the channels to be made on the case 2A as an alternative or in combination with those just discussed. In particular it has to be noted that in this example the outlet mouth of the channel 80 (that is its mouth opened towards the outside) has a shape that is at least partially annular, it being arranged at least partially about the mouth of the pipe 10 (or, likewise, 11).

More in details and with reference to figs. 2 and 3 (wherein some details are omitted for clarity reason) the measuring compartment 3 is configured as a cavity wherein the sensor 4 is housed, said cavity being defined by perimetral walls 3A, 3B, 3C: particularly there are shown a first wall 3A, a second wall 3B substantially parallel to each other and shell walls 3C connecting the first two walls 3A, 3B such to close and define the measuring compartment 3, that in this example has a substantially box- like shape.

Even the housing compartment 5 is defined by respective perimetral walls 5A, 5B, 5C: a first wall 5A, a second wall 5B substantially parallel to each other and shell walls 5C connecting the first two walls 5A, 5B such to close and define the housing compartment 5, that in this example has a substantially box-like shape too.

It has to be noted that in such solution no one of the perimetral walls 3A, 3B, 3C of the measuring compartment 3 is in common with the perimetral walls 5A, 5B, 5C of the housing compartment 5: therefore the two compartments 3 and 5 each has perimetral walls different from those of the other compartment.

In detail and with reference also to figures 2 and 3, at least one perimetral wall 3A of said measuring compartment 3 faces at least one perimetral wall 5A of the housing compartment 5.

On such facing walls 3A and 5A openings are formed for the passage of the data transmission physical line 7, in this example a male/ female plug connector: between the connector and the respective walls 3A and 5A respective gaskets 13A and 15A are arranged in order to prevent the fuel gas from passing.

Gaskets 13A and 15A can be indifferently single or multiple ones, depending on needs.

The hollow space 8, seen in fig.l, is defined at least partially by the facing walls 3A, 5A of the measuring compartment 3 and of the housing compartment 5 respectively. Therefore it is possible to see how the physical line 7 transmitting the data from the sensor 4 to the control unit 6 passes at the hollow space 8 with the advantages described above: thus it is suitable to further notice now that such hollow space 8 could extend also only in a small area comprised between the perimetral walls 3A, 5A, for example only in the area immediately surrounding the physical line 7. The assembled meter apparatus 1 in this embodiment looks like that shown in fig.4, that is its outer case 2 is simply formed by joining the perimetral walls 3B, 3C and 5B, 5C that define the compartments 3, 5 except for the walls of such compartments that face each other, that is 3A and 5A.

Further advantageous characteristics of the meter apparatus 1 are shown in figs. 5 to 8.

With a first reference to figs. 5 and 6 a manufacturing step by assembling the meter apparatus 1 is shown: in order to speed up the operations firstly the box-like structures or half-cases 2A, 2B are made which define the two compartments 3 and 5 comprising the perimetral walls identified above and then the two half-cases 2A, 2B are assembled together by simple snap fitting operations finished by a perimetral (optional) frame 90 visible in fig. 11.

In substance each one of the two compartments 3 and 5 is contained by a half -case 2A, 2B which is coupled to the other one by snap fitting.

As it is noted in figs. 5 to 8 on one of the perimetral walls of the electronics housing compartment 5, corresponding to the half-case 2A, substantially "C" shaped (or comprising an undercut anyway) engaging teeth 20 are made having an end, which project towards the outside and which are intended to engage an edge of the perimetral walls of the measuring compartment 3; thus the two half-cases 2A, 2B can be positioned beforehand respectively and joined by simply linearly translating one towards the other one, such as shown in figs. 5 and 6. In order to facilitate the snap coupling the two facing walls 3A, 5A each has at least one pair of pin 21 and relevant seat 22: in the shown example there are four pairs of pins 21 and relevant seats 22, but it is possible to provide also only one, or three or more of them.

Such pins 21 and seats 22 cooperate with each other such to guide the coupling of the two half-cases 2A, 2B when approaching the two half-cases in a straight line, and they engage with each other before the engagement of the teeth 20 with each other, such that the latter is performed when the alignment is already the proper one.

Still another advantageous characteristic is shown in the detail of figs. 9 and 10, where the data transmission physical line 7 is shown.

In this example it advantageously comprises a socket 71 provided with a plurality of rigid plugs 72 projecting from the wall 3A of the measuring compartment 3: such plugs 72 are electrically connected to the sensor and they transmit the data detected by it.

A gasket is provided about each plug 72, at the side of the compartment 3, such to prevent the gas from escaping around it, it is described and denoted above by the reference 13A.

Plugs 72 project towards the wall 5A where they find openings that receive them in the mounted condition, till they establish the electrical contact with the control unit 6, for example with its electronic board, such as shown in the annexed figures.

The gasket 15A is provided between the wall 5A and the board of the control unit 6, such to prevent the gas from possibly escaping through these openings.

It has to be noted that advantageously for each plug 72 a locking means is provided, for example a clip 73 preferably mounted on the board of the electronic control unit 6 and intended to hold the plug 72 in place.

As regards the clip 73 it advantageously not only acts for locking the corresponding plug 72, but also for guaranteeing a good electrical contact, and therefore a correct transmission of the data, therefore it being a part of the transmission line itself: the clip 73 is welded to the board of the control unit 6 and it is operatively connected to the electronic components of the board itself, such to contemporaneously act for mechanically tightening the plug, and for transmitting the data.

Finally, a further advantageous characteristic, shown in fig.11 relates to the presence of an anti-tampering seal, that comprises portions of a plastic frame 90 that are welded on the half-case 2A and they secure part of the edge of the adjacent half -case 2B, such that it is not only easy to assemble the meter apparatus 1 but it is also easy to see a tampering attempt, if any.

A variant of what described above up to now, with reference to the coupling of the half-cases 2A, 2B is shown in figs. 14-17, wherein the same numbers denote the same parts therefore no further reference is made thereto.

In this case, in short, the coupling occurs by rotating one half-case with respect to the other one.

With a first reference to figs. 14 and 15 they show a manufacturing step by assembling the meter apparatus according to such variant: also in this case firstly the half-cases 2A, 2B are made which define the two compartments 3 and 5 and then they are assembled together by snap fitting: as it is noted in fig. 14 on one of the perimetral walls of the electronics housing compartment 5, corresponding to the half- case 2A, an engaging seat 20' is made, having a substantially "C" shape projecting towards the outside and which is intended to engage an edge of the perimetral walls of the measuring compartment 3; thus the two half-cases 2A, 2B can be positioned beforehand respectively and then joined by a rotation, such as shown in fig. 14, 16 and 17: therefore the engaging seat 20' in this an example is a seat of rotation.

A further advantageous characteristic is the one shown in figs. 16, 17: the two facing walls 3 A, 5 A each has at least one pair of pin 21' and relevant seat 22': in the shown example there are provided two pairs of pins 21' and relevant seats 22', but it is possible to provide also only one, or three or more of them.

Such pins 21' and seats 22' cooperate with each other to guide the coupling of the two half-cases 2A, 2B during the rotation, such to guarantee a proper coupling.

On one half-case, for example the half-case 2A, at one edge opposite to that provided with the engaging seat 20 a snap retaining lip 25 is made, visible in fig.14, which is intended to engage a corresponding edge of the other half-case 2B, such that, once completing the rotation of one half -case with respect to the other one, they are snap fastened together.

Thus the objects mentioned above are achieved.

Obviously similar variants with respect to what described up to now fall within the knowledge of the person skilled in the art, all of them to be intended as falling within the scope of the present invention.