Oscillating piston liquid meter chamber and meter comprising such a chamber

Abstract

Oscillating Piston Liquid Meter Chamber and Meter Comprising Such a Chamber The invention relates to a measuring chamber (1) of an oscillating piston (3) liquid meter, which comprises a cylindrical side wall (4), a bottom, a cover and a partition extending radially inwards from the cylindrical side wall (4) and the piston (3) comprising a cylindrical body (8) traversed by a flat wall (9) forming a discoidal sail in one piece with it, this flat wall (9) being provided with through openings (10, 10'), chamber (1) characterized in that the through openings (10) of a first population of through openings (10, 10') of the discoidal sail (9) are distributed according to a staggered arrangement which is diverging towards the wall (8') of the cylindrical body (8) and which is provided by an elementary pattern (ME) repeated around the central axis of the piston (3),and in that the mutually adjacent through openings (10) of this first population are spaced at least a minimum distance apart. Figure to be published with the abbreviation: Fig. 7,

Description

Title of the invention: Oscillating piston liquid meter chamber and meter comprising such a chamber

[0001] The present invention relates to the field of liquid meters and more specifically to so-called oscillating piston liquid meters. Its object is a liquid meter chamber with an oscillating piston and a meter comprising such a chamber.

[0002] Counters of the aforementioned type are well known in the prior art, particularly for their accuracy and reliability. Such a counter is disclosed, for example, in US patent 3,369,614.

[0003] The applicant has also developed oscillating piston counters described in documents EP 0 627 614 and EP 1 946 050.

[0004] The present invention aims to provide an improved version of the counters of these last two documents, in particular in terms of resistance and wear resistance, and in particular to preserve the piston subjected to the flow of liquid.

[0005] In volumetric liquid meters such as those described in the aforementioned documents, the cylindrical oscillating piston is the cyclically moving part within the meter's measuring chamber. The piston's movement is transmitted to various components that count the volume of fluid passing through the meter.

[0006] During the movement of the piston induced by the fluid passing through the measuring chamber, the fluid must pass through a flat central area of ​​the piston (a flat wall forming a reinforcing web and a guiding element in the plane of piston movement within the chamber) to fill all the empty areas of the measuring chamber. Openings are created in this central area to allow the passage of the fluid. This passage creates an axial force on the piston, which reduces the wear resistance of this part, as well as of the parts of the chamber with which it is in contact. Since the functional spaces are very small in volumetric meters, even minimal wear of the part can lead to a loss of metrological performance.

[0007] It has already been proposed to solve this problem by creating cylindrical openings in the flat area of ​​the piston. However, the axial force remains significant and causes axial wear of the piston. Furthermore, the openings must remain small to avoid internal leakage that could reduce the meter's metrological performance. Thus, the openings in the piston of these known chamber designs are not optimized in terms of cross-sectional area and arrangement with respect to the piston's movement within the chamber.

[0008] Furthermore, in other proposed designs, the flat area is transferred to one end of the piston, but this creates more friction with the surface in contact with the measuring chamber, consequently slowing the piston down at low flow rates and reducing metrological performance. The balance of the part is also less optimal, resulting in reduced measurement efficiency.

[0009] The present invention aims to propose another solution to overcome the aforementioned disadvantages, and in particular to further reduce the axial force on the piston by maximizing the passage area at the piston, without compromising its mechanical strength and allowing its manufacture by injection of plastic material.

[0010] To this end, the invention's main object is a liquid metering chamber with an oscillating piston,

[0011] this chamber comprising a cylindrical side wall with a central axis, a bottom, a lid and a partition extending radially inwards from the cylindrical side wall,

[0012] the piston comprising a cylindrical body with a central axis and which is traversed by a flat wall forming a discoidal sail in one piece with it, this flat wall being provided with through openings and compartmentalizing the interior of said cylindrical body transversely with respect to its central axis,

[0013] the chamber and the piston comprising mutually cooperating means ensuring guided movement of said piston in the chamber, with rotation of the central axis of the piston around the central axis of the chamber,

[0014] a slot being present in the lateral wall of the cylindrical body and extending by a notch in the flat wall, and

[0015] the partition extending through the slot and into the notch with a depth and orientation that vary depending on the position of the piston in the chamber,

[0016] chamber characterized in that the through openings of a first population of through openings of the discoidal sail are distributed, when considered radially from the central axis of the piston, according to a staggered arrangement which is divergent in the direction of the wall of the cylindrical body and which is provided by an elementary pattern repeated around said central axis, and in that the mutually adjacent through openings of this first population are spaced apart from each other by at least a minimum distance, the through openings closest to a given through opening being advantageously all spaced from the latter by said distance.

[0017] It also relates to a liquid meter comprising such a chamber of measure.

[0018] The invention will be better understood from the following description, which relates to preferred embodiments, given by way of non-limiting examples, and explained with reference to the accompanying schematic drawings, in which:

[0019] [Fig-1] is a perspective view of an oscillating piston liquid meter comprising a measuring chamber according to an embodiment of the invention and mounted on a portion of conduit;

[0020] [Fig.2A] and [Fig.2B] are cross-sectional views along a vertical plane containing the median axis of the portion of the meter conduit shown [Fig.1];

[0021] [Fig.3] is a top view of the counter in Figures 1 and 2, the upper part with the meter and the measuring chamber cover removed (only the cylindrical sleeve of the cover is shown, which coincides with the cylindrical sleeve of the bottom of the measuring chamber);

[0022] [Fig.4A] and [Fig.4B] are top views of the measuring chamber shown [Fig.3], the piston being in a different position each time;

[0023] [Fig.5] is a perspective view and at a different scale of the piston mounted in the room shown in figures 3 and 4;

[0024] [Fig.6] is an exploded view of the chamber shown in figures 2, bottom and lid;

[0025] [Fig.7] is a top view similar to that of Figures 3 and 4 showing the radial and arc-shaped alignments of the through openings in the flat wall forming the piston's sail;

[0026] [Fig.8] is a perspective and bottom view of the measuring chamber shown exploded at [Fig.6];

[0027] [Fig.9] is a partial view and at a different scale of a region of the veil of the piston shown in figures 3, 4 and 7, showing the elementary pattern of through openings of the first population;

[0028] [Fig. 10] is a view of detail A of [Fig.9], at another scale;

[0029] [Fig. 11] is a partial view similar to [Fig. 9], showing the repetition of the pattern elementary and part of the staggered pattern generated by this repetition;

[0030] [Fig. 12] is a symbolic representation illustrating the definition of a through opening of the first population in the piston sail;

[0031] [Fig. 13A], [Fig.13B], [Fig.13C] and [Fig.13D] symbolically illustrate four consecutive steps for the definition of a through opening of the first population in the piston web;

[0032] [Fig.l4A], [Fig.l4B], [Fig.l4C] and [Fig.l4D] illustrate the circulation of the liquid in the measuring chamber and through the piston sail, as a function of the position of the latter in its cyclic oscillating movement;

[0033] [Fig. 15] is a top view of an alternative embodiment of a piston;

[0034] [Fig.16A], [Fig.16B], [Fig.10C], [Fig.16D], [Fig.16E], [Fig.16F], [Fig.16G] and [Fig.10H] illustrate different successive positions during the relative movement of the measuring chamber in the reference frame of the piston, for a cyclic movement of the latter;

[0035] [Fig. 17] is a symbolic representation illustrating the trajectory of the cylindrical sleeves and the central stud of the measuring chamber cover, by synthesis of the successive positions of figures 16;

[0036] [Fig. 18] is a symbolic representation illustrating the implantation areas of the through-holes in the piston shell deduced from [Fig. 17], and,

[0037] [Fig. 19] is a partial view and at a different scale of a region of the web of the variant embodiment of the piston shown [Fig. 15], showing the elementary pattern of the through openings of the first population, like [Fig.9] for the variant embodiment of the piston of figures 3, 4 and 7.

[0038] [Fig.20] is a cross-sectional view of another oscillating piston liquid meter, according a vertical plane containing the median axis of the portion of conduit of said meter, which includes a measuring chamber according to another embodiment of the invention;

[0039] [Fig.21] is an exploded view and at a different scale of the chamber forming part of the counter shown [Fig.20];

[0040] [Fig.22] is a cross-sectional view along a vertical plane containing the central axes of the chamber and piston of the chamber shown in figures 20 and 21;

[0041] [Fig.23A] and [Fig.23B] are cross-sectional views similar to that of [Fig.22], but of the single chamber (with the piston removed), in the assembled state ([Fig.23A]) and in the exploded state ([Fig.23B]);

[0042] [Fig.24A] and [Fig.24B] are perspective views of the room shown figures 20 and 21, respectively without external filter on the supply openings ([Fig.24A]) and with such filters ([Fig.24B]).

[0043] Figures 1 to 12, 14, 16 and 20 to 24 all show, at least partially, a liquid meter chamber (1) with an oscillating piston (3).

[0044] This chamber (1) comprises a cylindrical side wall (4) with a central axis (AC1), a bottom (5), a cover (6), and a partition (7) extending radially inward from the cylindrical side wall (4). The piston (3) comprises a cylindrical body (8) with a central axis (AC2) through which a flat wall (9) passes, forming a discoidal shell integral with it. This flat wall (9) is provided with through openings (10, 10', 10") and compartmentalizes the interior of said cylindrical body (8) transversely with respect to its central axis (AC2).

[0045] In addition, a slot (12) is present in the lateral wall (8') of the cylindrical body (8) and extends through a notch (13) in the flat wall (9).

[0046] The partition (7) extends through the slot (12) and into the notch (13) with a depth and orientation that varies depending on the position of the piston (3) in the chamber (1).

[0047] The oscillating movement of the piston (3) in the measuring chamber (1) is entirely comparable to that described and represented in documents EP 0 627 614 or EP 1 946 050.

[0048] According to the invention, the through openings (10, 10”) of a first population of through openings (10, 10', 10”) of the discoidal veil (9) are distributed, when considered radially from the central axis (AC), according to a staggered arrangement which is divergent towards the wall (8') of the cylindrical body (8) and which is provided by an elementary pattern (ME) repeated around said central axis (AC2) of the piston (3), and the mutually adjacent through openings (10, 10”) of this first population are spaced from each other by at least a minimum distance (E), the through openings (10, 10”) closest to a determined through opening (10) advantageously all being spaced from the latter by said distance (E).

[0049] The aforementioned features of the invention make it possible to provide a measuring chamber with a piston offering an optimal compromise between, on the one hand, a maximum flow area for the liquid through its web (with a consequent limitation of the axial force on the piston and therefore improved wear resistance), and, on the other hand, good mechanical strength and the possibility of low-cost manufacturing by plastic injection molding. Indeed, the staggered arrangement of the openings (10) maximizes their number and ensures compliance with a minimum material thickness (E) between all the openings (10), guaranteeing sufficient rigidity and mechanical strength of the web and the piston. Furthermore, this network of minimal-width material bridges allows for good distribution of the molten thermoplastic material in the mold during injection.

[0050] As can be seen from the accompanying figures, and in accordance with an advantageous embodiment of the invention, the piston (3) is provided to comprise two opposing half-axes (11, 11') extending on either side of said web (9) and together defining the central axis (AC2) of the cylindrical body (8). Furthermore, the bottom (5) and the cover (6) are advantageously provided with identical internal cylindrical sleeves (14, 14'), mutually aligned and arranged all around the central axis (AC2). In addition, these two sleeves (14, 14') advantageously extend towards each other within the chamber (1) and receive between them, with a sliding support, the flat wall (9) of the piston (3). Finally, one (14) of these two sleeves (14, 14') advantageously forms with a nipple (16) which is aligned with the central axis (AC1) of the chamber (1), is formed on the bottom (5) or the cover (6) and is located inside this sleeve (14), a circular path of guided circulation, around said central axis (AC1), for a cylindrical roller (11) formed by one of the half-axes (11, 11'), ensuring the guided movement of said piston (3) in the chamber (1) during which the cylindrical body (8) of the piston (3) also moves in support on the inner face of the cylindrical side wall (4) of the chamber (1).

[0051] More specifically, and still in accordance with the aforementioned advantageous embodiment, the cylindrical roller (11) and the lateral wall (8') of the cylindrical body (8) of the piston (3), on the one hand, and the wall of at least one (14) of the internal cylindrical sleeves (14, 14') of the bottom (5) and the cover (6) and the cylindrical lateral wall (4) of the chamber (1), on the other hand, are configured such that the cylindrical roller (11) moves in a rolling-sliding bearing on the inner face of the wall of the relevant internal cylindrical sleeve (14), advantageously guided between this sleeve and the central stud (16), and that the lateral wall (8') of the cylindrical body (8) of the piston (3) moves in a rolling-sliding bearing on the inner face of the cylindrical lateral wall (4) of the chamber (1) during the cyclic oscillating movement of the piston (3) in the chamber (1) under the action of the liquid circulating (L) through the latter.Of course, the other half-axis (11') also travels in rolling-sliding support on the inner face of the wall of the other sleeve (14'), not associated with a nipple (16).

[0052] As can also be seen from the various figures, the partition (7) is fixed in the chamber (1) and can be formed as a single unit with the lid (6) or the base (5), and optionally the cylindrical side wall (4), or be mounted as a single unit in one of these parts (as shown in Figures 3, 4, 6, 14, 16 and 17). Alternatively, this fixed partition (7) can also be formed of two constituent parts assembled together during the construction of the chamber (1). Each of the two parts can be formed as a single unit with, or be mounted in, the lid and the base respectively (see Figures 23).

[0053] This fixed wall (7) extends through the slot (12) and into the notch (13) with a depth and orientation which vary, as shown for example in figures 14 and 16, depending on the position of the piston (3) in the chamber (1) and the position of the cylindrical roller (11) in the sleeve (14, 14') which receives it, during the cyclic oscillating movement of the piston (3) in the chamber (1) under the action of a liquid (L) circulating through the latter between at least one supply opening (1') and at least one discharge opening (1”).

[0054] The piston (3) and the components of the measuring chamber (2) itself (the cylindrical side wall (4), the bottom (5) and the cover (6)) can advantageously be manufactured by injection molding of thermoplastic material, for example from the styrene family, such as polystyrene. The wall (4) can can be made in one piece indifferently with the lid (6) or the base (5), advantageously with the lid (6) as shown in figures 6, 21 and 23.

[0055] In accordance with a preferred embodiment, and as shown by way of examples in Figures 7, 9 and 11, the elementary pattern (ME) which is repeated, with an angular pitch (PA), around the central axis (AC2) of the piston comprises two radial alignments (AR1, AR2) of through openings (10, 10”), which are partially mutually interlocked with alternating their respective through openings (10, 10”) and spaced from each other by an angle (A) around this central axis (AC2), corresponding to half of the angular pitch of repetition (PA).

[0056] Taking into account the application of the aforementioned rules for determining their location, and as illustrated by [Fig.5], 7 and 11, the openings (10, 10”) of the first population of through openings (10, 10', 10”), are arranged according to linear arrangements in arcs of circles (ALI, AL2), these linear arrangements (ALI, AL2) extending from the central zone (15) surrounding the cylindrical pebble (11) or from the zone (15') surrounding the notch (13) towards the peripheral zone (15”) of the discoidal veil (9) connected to the lateral wall (8') of the cylindrical body (8).

[0057] More specifically, the openings (10) of the first population of through openings (10, 10') are arranged according to a pattern formed of two series of linear arrangements (ALI, AL2) in arcs of circles nested one inside the other, each linear arrangement (ALI, AL2) having a radius of curvature identical to the radius of the cylindrical sleeves (14, 14') and the linear arrangements (ALI, AL2) of the same series of linear arrangements having the same direction of inclination or winding around the cylindrical roller (11).

[0058] In fact, each through opening (10) of the first population belongs to two linear arrangements (ALI and AL2) in arc of circle, each belonging to a different series of linear arrangements (ALI, AL2), the through opening (10) considered constituting the intersection between the two linear arrangements (ALI, AL2) of the two series to which it belongs simultaneously.

[0059] In order to provide a maximum passage cross-section, combined with the possibility of easy complete sealing by the cylindrical sleeves (14, 14') and compliance with the minimum spacing (E) between openings, it is advantageously provided that the through openings (10, 10”) of the first group have, where applicable at least for a majority of openings (10), a general shape of parallelograms or rhombuses. Furthermore, the spacing between each pair of two opposite sides of the parallelogram or rhombus formed by each through opening (10) is advantageously at most equal to, and preferably slightly less than, the thickness of the walls of the two cylindrical sleeves (14, 14').

[0060] In addition, to respect the staggered arrangement, one of the two diagonals of each of these through openings (10) of the same radial alignment (AR1, AR2) is collinear or coincident with the axis of the radial alignment (AR1, AR2) to which the said through openings (10) concerned belong.

[0061] Given the constraints indicated above, and as shown more particularly in Figures 7, 9 and 11, the through-holes (10) in the form of parallelograms or rhombuses of the same radial alignment (AR1, AR2) have different shapes and sizes, and in particular variable diagonal lengths depending on their distance from the central axis (AC2) of the piston (3), preferably with a progressive shortening of the diagonal collinear with or coinciding with the axis of the radial alignment (AR1, AR2) concerned and a progressive lengthening of the other diagonal, the set of through-holes (10) of the radial alignments (AR1, AR2) of one of the two types, thus forming concentric circular arrangements of through-holes (10) of identical shape and size, centered on the central axis (AC), an additional internal circular arrangement of polygonal through-holes (10”), by hexagonal example,belonging to one of the two types of radial alignments (AR1, AR2), which may also be present.

[0062] These through openings (10”) of this additional internal circular arrangement and having a polygonal shape, in particular hexagonal on the attached drawings, actually correspond to parallelograms or truncated rhombuses due to compliance with the minimum spacing (E) between the through openings (10, 10”) neighboring the first population.

[0063] As is also apparent from figures 7, 9 and 11 in particular, the through openings (10, 10”) of the first population, advantageously comprising through openings (10) in the form of parallelograms or rhombuses and through openings (10”) of polygonal shape, constitute concentric circular arrangements around the central axis (AC2) of the piston (3) with alternating arrangements of openings (10, 10”) belonging to the two radial alignments (AR1, AR2) and offset of an angle (A) between through openings (10, 10”) of two neighboring arrangements.

[0064] In accordance with a preferred design feature of the invention, related to the practical implementation of through-holes, the through-holes (10) in the shape of parallelograms or rhombuses have sides that correspond to arcs of circles, the sides of each of the two pairs of opposite sides forming the parallelogram or rhombus of a through-hole (10) being defined by the intersection of portions of the outer and inner circumferences of different radii (RI and R2) of the internal cylindrical sleeves (14, 14') in the two positions of the piston (3) occupied by the latter during the realization of its cyclic oscillating movement and in which said internal cylindrical sleeves (14, 14') close the relevant through opening (10).

[0065] Thus, the radius of curvature (RI) and the paths of the circular arcs forming the inner sides of the through openings (10) with respect to the central axis (AC) are defined by the radius of curvature and the path of the inner circumference of the internal cylindrical sleeves (14, 14'). Similarly, the radius of curvature (R2) and the paths of the circular arcs forming the outer sides of the through openings (10) with respect to the central axis (AC2) are defined by the radius of curvature and the path of the outer circumference of said internal cylindrical sleeves (14, 14'), this for all said through openings (10), but also, where applicable, for the relevant sides of the hexagonal through openings (10”).

[0066] The geometric definition of a through opening (10) is illustrated synthetically (by superposition) on [Fig. 12], for an opening located on a radial alignment (AR1) coinciding with the median plane (PM) of the web (9) of the piston (3).

[0067] It is also illustrated in the form of four successive sequences in Figures 13, for an opening (10) located on another radial alignment (AR1, AR2). In these figures, the reference numerals 14, 14' denote the median circles of the cylindrical sleeves, and the dashed circle around the roller (11) represents the trajectory of the central point of the pin (16) around said roller. It should be noted that after locating the central point (17) of a future opening (10), in accordance with the desired staggered arrangement, the sides of the opening are determined by the portions of the walls of the cylindrical sleeves when their median circles intersect the central point in the two possible positions of the piston (3) fulfilling this condition.

[0068] In accordance with another beneficial feature of the invention, allowing a significant increase in the cross-section through the web (9) of the piston (3), illustrated by way of example in Figures 4, 5, 7, 9, 11 and 14 to 16, the through openings (10, 10') comprise a second population of through openings (10') which are arranged to form together a discontinuous open peripheral band, present on the periphery of the discoidal web (9) and extending along the inner face of the lateral wall (8') of the cylindrical body (8) of the piston (3), the width of said open band being at most, preferably substantially equal to the width of the wall of the cylindrical sleeves (14, 14') and said through openings (10') advantageously having a curved rectangular shape, or a portion of a ring.

[0069] As with the through-openings (10, 10”) of the first population between each other, and for the same reasons, it is advantageously provided that the peripheral through-openings (10') of the second population are spaced through openings (10) closest to the first population, and advantageously between them, at least of the minimum distance (E), preferably substantially of this distance (E).

[0070] The material bridges interrupting the peripheral open band and delimiting the through openings (10') of the second population may possibly just be sufficient in number and thickness to obtain a sufficiently rigid and resistant bond between the web (9) and the lateral wall (8') forming the cylindrical body (8) of the piston (3), as illustrated for example by the variant embodiment of [Fig.15].

[0071] However, a construction such as that shown in the other figures mentioned above is preferred, particularly for considerations of injection molding and piston rigidity. It should be noted that it can also be provided that the repetition pitch or the angular extension around the central axis (AC) of the elementary motif (ME) of the through openings (10) of the first population corresponds to the repetition pitch of the through openings (10') of the second population along the periphery of the discoidal web (9) as seen for example in Figures 9 and 11.

[0072] As also shown in the figures, and for considerations of rigidity and mechanical strength of the piston and simultaneously of optimization of the passage of liquid through the piston and of control of said passage, the through openings (10, 10', 10") are present over the entire surface of the flat wall (9) with the exception of a central zone (15) surrounding the two half-axes (11 and 11'), corresponding to the zone of the flat wall (9) swept by the cylindrical roller (11), and a border zone (15') surrounding the notch (13), both of which are solid and continuous.Furthermore, the size of said through openings (10, 10') increases from said central or bordering zone (15, 15') towards the cylindrical side wall (4) and these through openings (10, 10') are configured in terms of size and shape and arranged in terms of position and orientation of the through openings (10, 10') in such a way that each of them is totally closed by the cylindrical sleeves (14, 14') in at least two positions occupied by the piston (3) in the chamber (1) during its cyclic oscillating movement.

[0073] Figure 18 shows the three zones (Z1, Z2, Z3) of the piston (3) web (9) relevant for the placement of the through-holes (10, 10', 10”), namely: zone (Z1) where any opening is unnecessary; zone (Z2) where the through-holes (10 and 10”) of the first group are placed (with the conditions mentioned above and the possibility of hermetically sealing the internal and external volumes of the cylindrical sleeves (14, 14') in the measuring chamber (1)); and zone (Z3) where a full opening is desired, albeit with design and manufacturing limitations. The absence of openings (10, 10”) in the central and bordering zones (15, 15’) mentioned above contributes to the rigidity and mechanical strength of the web (9) and the piston (3).

[0074] These three distinct zones derive from [Fig. 17] which show the trajectories (CC14, CCI6) of the internal and external faces of the walls of the cylindrical sleeves (14, 14') relative to the reference frame of the web (9) of the piston (3).

[0075] In order to provide a smooth flow of liquid through the piston, it is advantageously provided that the through openings (10, 10', 10") and the notch (13) are configured in such a way, in terms of shape, size and arrangement in the flat wall (9), that the ratio of the sections passing through the latter, on the one hand, inside the cylindrical sleeves (14, 14'), and, on the other hand, outside the latter, has a substantially constant value regardless of the position of the piston (3) in the chamber (1).

[0076] Furthermore, in order to achieve a shape allowing a homogeneous distribution of the material during injection in relation to the minimum gap (E), as well as a possibility of reliable and precise reversible operation of the measuring chamber in relation to the movement of the piston (3), the through openings (10, 10') are advantageously arranged and distributed symmetrically with respect to a median plane (PM) of the notch (13), perpendicular to the plane of the discoidal sail (9) and containing the axis of the cylindrical roller (11).

[0077] The various characteristics described above in relation to the embodiment shown in Figures 1 to 19 and concerning the piston (3), the web (9) and the through openings of the latter, also apply to the alternative embodiment shown in Figures 20 to 24, although they do not appear directly from these figures.

[0078] As shown in the relevant accompanying figures, the liquid (L) inlet (1') and outlet (1”) can both be located in the bottom (5) of the chamber (1) and situated on either side of the fixed partition (7). Alternatively, one of said openings (1', 1”) can be located in the lid (6), for example in the form of an open shell with the side wall (4) and defining the internal volume of the measuring chamber (1), and the other in the bottom (5), which closes said shell.

[0079] According to yet another variant, at least two supply openings (1') and / or at least two discharge openings (1”) may be provided, of which at least one (supply and / or discharge) may be located in the side wall (4), as shown for example in Fig. 24A. When the chamber (1) has more than one supply and / or discharge opening, only a portion of the liquid flow passing through the chamber (1) may, if necessary, pass through the web (9) of the piston (3). Nevertheless, the improvements and advantages brought about by the invention remain significant in this case as well.

[0080] The invention also relates, as shown in Figures 1, 2, and 20, to a liquid meter (2) with an oscillating piston (3), characterized in that it comprises a liquid meter measuring chamber (1) containing said oscillating piston (3), as described above. It should be noted that the chamber (1) and its improved oscillating piston (3) of the invention can be installed in existing meters, having the same dimensions, external shape, and fluid and mechanical connections as the existing chambers, which they can thus replace either during the manufacturing of the meters concerned or during maintenance operations.

[0081] Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Demands

1. A liquid meter chamber (1) (2) with an oscillating piston (3), the chamber (1) comprising a cylindrical side wall (4) with a central axis (AC1), a bottom (5), a cover (6), and a partition (7) extending radially inward from the cylindrical side wall (4), the piston (3) comprising a cylindrical body (8) with a central axis (AC2) and traversed by a flat wall (9) forming a discoidal shell integral with it, this flat wall (9) being provided with through openings (10, 10', 10") and compartmentalizing the interior of said cylindrical body (8) transversely with respect to its central axis (AC2), the chamber (1) and the piston (3) comprising mutually cooperating means (11, 11', 14, 14') ensuring guided movement of said piston (3) within the chamber (1), with rotation of the central axis (AC2) of the piston (3) around the central axis (AC1) of chamber (1),a slot (12) being present in the lateral wall (8') of the cylindrical body (8) and extending through a notch (13) in the flat wall (9), and the partition (7) extending through the slot (12) and into the notch (13) with a depth and orientation that vary according to the position of the piston (3) in the chamber (1), chamber (1) characterized in that the through-openings (10, 10”) of a first population of through-openings (10, 10', 10”) of the discoidal shell (9) are distributed, when considered radially from the central axis (AC2) of the piston (3), according to a staggered arrangement that diverges in the direction of the wall (8') of the cylindrical body (8) and that is provided by an elementary pattern (ME) repeated around said central axis (AC2), and in that the through-openings (10, 10”) mutually adjacent to this first population are spaced at least a minimum distance (E) apart from each other, the through openings (10,10”) the closest to a determined through opening (10) being advantageously all spaced from the latter by said distance (E).,

2. Liquid meter chamber according to claim 1, characterized in that the piston (3) comprises two half-axes (11, 11') opposite, extending on either side of said web (9) and together defining the central axis (AC2) of the cylindrical body (8), and / or, in that the bottom (5) and the cover (6) are provided with identical internal cylindrical sleeves (14, 14'), mutually aligned and arranged all around the central axis (AC2), and / or, in that these two sleeves (14, 14') extend towards each other inside the chamber (1) and receive between them, with sliding support, the flat wall (9) of the piston (3), and / or, in that at least one (14) of these two sleeves (14, 14') forms with at least one stud (16), aligned with the central axis (AC1) of the chamber (1), formed on the bottom (5) or the cover (6) and located inside this sleeve (14), a circular guided circulation path, around said central axis (AC1), for a cylindrical roller (11) formed by one of the half-axes (11, 11'),ensuring the guided movement of said piston (3) in the chamber (1) during which the cylindrical body (8) of the piston (3) also moves while bearing against the inner face of the cylindrical side wall (4) of the chamber (1).

3. Liquid meter chamber according to claim 1 or 2, characterized in that the elementary pattern (ME) which is repeated, with an angular pitch (PA), around the central axis (AC2) of the piston (3) comprises two radial alignments (AR1, AR2) of through openings (10, 10”), which are partially mutually interlocked with alternating their respective through openings (10, 10”) and spaced from each other by an angle (A) around this central axis (AC2), corresponding to half of the angular pitch of repetition (PA).

4. Liquid meter chamber according to claim 3, characterized in that the through openings (10, 10”) of the first population have, where appropriate at least for a majority of openings (10), a general shape of parallelograms or rhombuses, and in that one of the two diagonals of each of these through openings (10) of the same radial alignment (AR1, AR2) is collinear with or coincident with the axis of the radial alignment (AR1, AR2) to which said through openings (10) belong.

5. Liquid metering chamber according to claims 3 and 4, characterized in that the through openings (10) are in the shape of parallelograms or rhombuses of the same radial alignment (AR1, AR2) have different shapes and sizes, and in particular variable diagonal lengths depending on their distance from the central axis (AC2) of the piston (3), preferably with a progressive shortening of the diagonal collinear with or coinciding with the axis of the radial alignment (AR1, AR2) concerned and a progressive lengthening of the other diagonal, the set of through openings (10) of the radial alignments (AR1, AR2) of one of the two types, thus forming concentric circular arrangements of through openings (10) of identical shape and size, centered on the central axis (AC2), an additional internal circular arrangement of through openings (10”) of polygonal shape, for example hexagonal, belonging to one of the two types of radial alignments (AR1, AR2), may also be present.

6. Liquid meter chamber according to any one of claims 1 to 4, characterized in that the through openings (10, 10”) of the first population, advantageously comprising through openings (10) in the form of parallelograms or rhombuses and through openings (10”) of polygonal shape, constitute concentric circular arrangements around the central axis (AC2) of the piston (3) with alternating arrangements of openings (10, 10”) belonging to the two radial alignments (AR1, AR2) and offset by an angle (A) between through openings (10, 10”) of two neighboring arrangements.

7. Liquid meter chamber according to any one of claims 4 to 6, provided that they depend on claim 2, characterized in that the parallelogram- or rhombus-shaped through openings (10) have sides that correspond to arcs of circles, the sides of each of the two pairs of opposite sides forming the parallelogram or rhombus of a through opening (10) being defined by the intersection of portions of the outer and inner circumferences of different radii (RI and R2) of the internal cylindrical sleeves (14, 14') in the two positions of the piston (3) occupied by the latter during the realization of its cyclic oscillating movement and in which said internal cylindrical sleeves (14, 14') close the relevant through opening (10).

8. Liquid meter chamber according to claim 2 or any one of claims 3 to 7, provided that they depend on claim 2, characterized in that the through openings (10, 10') comprise a second population of through openings (10') which are arranged to form together a discontinuous open peripheral band, present on the periphery of the discoidal veil (9) and extending along the inner face of the lateral wall (8') of the cylindrical body (8) of the piston (3), the width of said open band being at most, preferably substantially, equal to the width of the wall of the cylindrical sleeves (14, 14') and said through openings (10') advantageously having a curved rectangular shape, or a portion of a ring.

9. Liquid meter chamber according to claim 8, characterized in that the peripheral through openings (10') of the second population are spaced from the nearest through openings (10) of the first population, and advantageously from each other, at least by the minimum distance (E), preferably substantially by this distance (E).

10. A liquid metering chamber according to claim 2 or any one of claims 3 to 9, insofar as they depend on claim 2, characterized in that the through-openings (10, 10', 10") are present over the entire surface of the flat wall (9) except for a central area (15) surrounding the two half-axes (11 and 11'), corresponding to the area of ​​the flat wall (9) swept by the cylindrical roller (11), and a bordering area (15') surrounding the notch (13), both solid and continuous, in that the size of said through-openings (10, 10') increases from said central or bordering area (15, 15') towards the cylindrical side wall (4), and in that the through-openings (10, 10') are configured in terms of size and shape and arranged in terms of position and orientation of through openings (10,10') in such a way that each of them is totally sealed by the cylindrical sleeves (14, 14') in at least two positions occupied by the piston (3) in the chamber (1) during its cyclic oscillating movement.

11. Liquid meter chamber according to claim 2 or any one of claims 3 to 9, provided that they depend on claim 2, characterized in that the through openings (10, 10', 10") and the notch (13) are configured in such a way, in terms of shapes, size and arrangement in the flat wall (9), that the ratio of the sections passing through the latter, on the one hand, inside the cylindrical sleeves (14, 14'), and, on the other hand, outside the latter, has a substantially constant value regardless of the position of the piston (3) in the chamber (1).

12. Liquid meter chamber according to any one of claims 1 to 11, characterized in that the through openings (10, 10') are arranged and distributed symmetrically with respect to a median plane (PM) of the notch (13), perpendicular to the plane of the discoidal veil (9) and containing the axis of the cylindrical roller (11).

13. A liquid metering chamber according to claim 2 or any one of claims 3 to 12, provided they depend on claim 2, characterized in that the cylindrical roller (11) and the side wall (8') of the cylindrical body (8) of the piston (3), on the one hand, and the wall of at least one of the internal cylindrical sleeves (14, 14') of the bottom (5) and the cover (6) and the cylindrical side wall (4) of the chamber (1), on the other hand, are configured such that the cylindrical roller (11) moves in a rolling-sliding bearing on the inner face of the wall of the relevant internal cylindrical sleeve (14, 14') and the side wall (8') of the cylindrical body (8) of the piston (3) moves in a rolling-sliding bearing on the inner face of the cylindrical side wall (4) of the chamber (1) during the cyclic oscillating movement of the piston (3) in the chamber (1) under the action of the circulating liquid (L) passing through the latter.

14. Liquid meter chamber according to claim 13, characterized in that the internal cylindrical sleeve (14) concerned by the circulation of the cylindrical roller (11) is associated with a central stud (16) defining with the wall of said sleeve (14) a circulation path for said cylindrical roller (11).

15. Liquid meter (2) with oscillating piston (3), characterized in that it comprises a liquid meter measuring chamber (1), enclosing the oscillating piston (3), according to any one of claims 1 to 14.

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