Filter system for a side wall of an enclosure for collecting water such as a gully

Abstract

A filter system (1) intended to be fitted to a side wall of a water collection enclosure such as a well or pit through which a drainage pipe opens, said filter system being configured to filter the water from the collection enclosure flowing into the drainage pipe, the filter system comprising: - a filter holder (2) comprising a first frame (20) intended to be fixed to the side wall of the well, - a filter (3) comprising a second frame (30), and a filtering means (31) held by the second frame (30), - fixing means between the filter (3) and the filter holder (2) comprising lugs (4) carried by the second frame (30) extending outwards from two uprights of the second frame (30), and slots (5) integral with the first frame (20), receiving the lugs (4) in a removable manner.

Description

[0001] This disclosure relates to a filter system, as well as a manhole equipped with such a filter system. Technical field

[0002] The present disclosure relates to the field of rainwater filtration, and more particularly to filter systems fitted to manholes. It is thus known to equip the collection enclosure of a manhole with a filter system, fixed to the side wall of the enclosure, at the mouth of a drainage pipe.

[0003] The filter system provides initial filtration of rainwater, retaining the materials retained by the filtering medium in the collection enclosure, so that only the water filtered by the filtering medium flows into the drainage pipe.

[0004] The filter system usually comprises a filter holder, comprising a first frame fixed to the side wall of the collection enclosure, and a filter comprising a second frame and a filtering means retained by this second frame.

[0005] The filter holder is permanently fixed to the side wall of the manhole, while the filter is typically a cleanable stainless steel grid, removably fixed to the filter holder, and which must be changed easily and quickly, periodically, when the filter medium becomes clogged. Prior art

[0006] According to a first known state of the art, it is known to equip the uprights of the first frame with two slide profiles and a lower stop. The second filter frame is then fixed, by inserting its two uprights respectively into the two slides, and until the lower crosspiece makes contact with the lower stop.

[0007] When the filter is due to be changed, it is simply lifted to slide it out until it is extracted, which requires a sliding stroke, roughly equal to the height of the filter, before the filter can be extracted. In some wells with reduced volume, this clearance is not available, and this then prevents the filter from being removed in line with the manhole.

[0008] It is also known to the present inventor of document FR.2916.458 A1, a filter system whose removable fixing means comprise two pairs of pins (or lugs), with a first pair of lugs, in the lower part of the uprights of the second frame of the filter, and a second pair of lugs, in the upper part of the uprights of the frame, and which are intended to cooperate with four open ears, namely respectively with a first pair of open ears projecting in the upper part of the first frame and a second pair of open ears projecting in the lower part of the second frame.

[0009] According to this teaching, the filter can be extracted from the filter holder, by releasing the lugs from the ears, and with an extraction stroke much less than the height dimension of the filter. Such a filter system can be mounted in a manhole, even when it is compact.

[0010] Conversely, placing the filter on the filter holder requires the four lugs of the filter to be aligned simultaneously with the four ears of the filter holder, this operation typically being carried out remotely by the operator using a pole illustrated in the first figure of document FR.2916.458 A1.

[0011] According to the inventor's findings, placing the filter on the filter holder may require a certain amount of dexterity on the part of the operator, particularly when the pole is used, and in particular to simultaneously position the four lugs of the filter in correspondence with the four open ears of the filter holder. Summary

[0012] This disclosure improves the situation.

[0013] There is provided a filter system for equipping a side wall of a water collection enclosure such as a well or pit through which a drainage pipe opens, said filter system being configured to filter water from the collection enclosure flowing into the drainage pipe, the filter system comprising: a filter holder comprising a first frame intended to be fixed to the side wall of the well, a filter comprising a second frame, and a filtering means held by the second frame, fixing means between the filter and the filter holder comprising: according to a first possibility, lugs carried by the second frame extending in projection towards the outside of two uprights of the second frame, and slots integral with the first frame, receiving the lugs in a removable manner, or conversely, according to a second possibility, lugs carried by the first frame extending in projection towards the inside of two uprights of the first frame, and slots integral with the second frame; receiving the lugs in a removable manner.

[0014] According to the present disclosure, said fixing means between the filter and the filter holder comprise a single pair of said lugs, positioned halfway up the uprights of said second frame according to the first possibility, or positioned halfway up the first frame according to the second possibility, the lugs of the pair, received removably in the slots of a single pair of slots, said slots received halfway up the uprights of the first frame of the filter holder according to the first possibility, or received halfway up the uprights of the second frame according to the second possibility.

[0015] The features set out in the following paragraphs may optionally be implemented. They may be implemented independently of each other or in combination with each other: the first frame of the filter holder comprises a peripheral wall against which the filtering means bears on a periphery when the filter and the filter holder are fixed to each other by said fixing means, the lugs received in the slots, the peripheral wall comprising a central opening intended to be crossed by the water filtered by said filtering means; the slots of the pair are parallel in themselves, and inclined relative to the peripheral wall of the first frame according to the first possibility, or else inclined relative to a plane of the second frame according to the second possibility, at least along two portions of length, respective of the two slots, called clamping slots cooperating with the lugs to ensure the pressurization of the filtering means on the periphery of the peripheral wall;the angle of inclination between the axis of each portion of the clamping length of the slots and the peripheral wall according to the first possibility, or between the axis of each portion of the clamping length of the slots and the plane of the second frame according to the second possibility is between 1° and 45°, for example between 3° and 25°, the two portions of the clamping length of the slots respectively have two local reductions in thickness, of a dimension smaller than the lugs, ensuring the locking of the lugs in the slots and the locking of the filter to the filter holder;each portion of clamping length of the slots is preceded by an entry portion, extending in a direction perpendicular to a plane of the first frame or in a direction inclined at an angle relative to the perpendicular direction of between 0° and 60°, for example between 0° and 45°, according to the first possibility or extending in a direction perpendicular to a plane of the second frame, or in a direction inclined at an angle relative to the perpendicular direction of between 0° and 60°, for example between 0° and 45°, according to the second possibility, the entry portion and the portion of clamping length of each slot forming an elbow at their junction, the angle centered on the elbow between the axis of the entry portion and the axis of the portion of clamping length being an obtuse angle; the entry portion of each slot has a convergent shape;the two uprights of the first frame of the filter holder comprise the two rising parts of the peripheral wall, as well as two guide walls extending in projection from the peripheral wall, in a manner parallel to each other, respectively carrying the two slots of said single pair of slots according to the first possibility, or else respectively carrying the two lugs of said pair of lugs according to the second possibility, the two guide walls cooperating with two opposite walls of the uprights of said second frame when fixing the filter to the filter holder. ;

[0016] According to one embodiment: the two guide walls extending in parallel over the entire height of the uprights of the first frame, and in which two crosspieces extend transversely, at the top and bottom of the first frame, including: the lower transverse portion of the peripheral wall, and a first transverse wall connecting the lower parts of the two guide walls extending projecting from the peripheral wall, and the upper transverse portion of the peripheral wall and a second transverse wall connecting the upper parts of two guide walls.

[0017] According to one embodiment, the second transverse wall comprises a notch providing access to a gripping means on an upper crosspiece of the second filter frame.

[0018] According to one embodiment, the first frame, including the peripheral wall, the guide walls of the uprights of the first frame carrying the slots of said single pair of slots according to the first possibility or carrying the lugs according to the second possibility, or even the first transverse wall, bottom and the second transverse wall, top, are obtained by cutting and folding a single piece of metal sheet.

[0019] According to a second aspect, the present disclosure relates to a manhole comprising a collection enclosure comprising a side wall, a drainage pipe opening at an opening in the side wall, as well as a filter system, internal to the collection enclosure, opposite the opening, the first frame of the filter holder fixed to the side wall of said collection enclosure. Brief description of the drawings

[0020] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which: Fig. 1 [ Fig. 1 ] is a perspective view of the filter system according to the present disclosure comprising a filter holder with a first frame, and a filter comprising a second frame and a filtering means, the filter coupled to the filter holder by insertion of two lugs integral with the uprights of the second frame into slots in the uprights of the first frame. Fig. 2 [ Fig. 2 ] is a detail view of the filter holder, when the filter is removed. Fig. 3 [ Fig. 3 ] is a detail view of the filter when the filter holder is not shown. Fig. 4 [ Fig. 4] is a sectional view of the filter system when the filter is coupled to the filter holder, illustrating more particularly the maintenance of the filtering means in the second frame of the filter, by complementary shape between semi-tubular profiles of the second frame and the filtering means, as well as the sealing of the filtering means on the periphery of a peripheral wall of the first frame. Fig. 5 [ Fig. 5 ] is a detail view of the figure 4 . Fig. 6 [ Fig. 6 ] is a detail view of a slot according to the present disclosure, including a convergent inlet portion, axis oriented substantially perpendicular to the plane of the second frame, followed by a clamping length portion, axis inclined relative to the plane and to the peripheral wall by an angle α of between 3° and 25°, said inlet portion and the clamping length portion forming an elbow at their junction. Fig. 7 [ Fig. 7] is a side view of a second embodiment of a slot path, including an entry portion inclined relative to a direction perpendicular to the plane of the first frame, followed by a clamping length portion of the slot. Description of the embodiments

[0021] The drawings and description below contain, for the most part, elements of a certain character. They may therefore not only serve to better understand this disclosure, but also contribute to its definition, if necessary.

[0022] Also, the present disclosure relates to a filter system 1 intended to equip a side wall of a water collection enclosure such as a well or a pit through which a drainage pipe opens, said filter system being configured to filter the water coming from the collection enclosure flowing into the drainage pipe.

[0023] The filter system includes: a filter holder 2 comprising a first frame 20 intended to be fixed to the side wall of the well, a filter 3 comprising a second frame 30, and a filtering means 31 held by the second frame 30, fixing means between the filter 3 and the filter holder 2 comprising lugs 4 carried by the second frame 30 extending projecting towards the outside of two uprights of the second frame 30, and slots 5 secured to the first frame 20, receiving the lugs 4 in a removable manner, and according to a first possibility illustrated in the figures.

[0024] According to a second possibility of the fixing means (not illustrated), the lugs and the slots are in an inverted configuration, namely that the lugs are carried by the first frame extending in projection towards the inside of two uprights of the first frame, and the slots are integral with the second frame; receiving the lugs in a removable manner. The fixing of the filter 3 to the filter holder 2 is obtained by insertion of the lugs 4 of the filter according to the first possibility, or of the lugs 4 carried by the first frame according to the second possibility, in the slots 5. The insertion or extraction stroke of the lugs 4 in the slots 5 to ensure the fixing of the filter to the filter holder, or on the contrary its extraction is a dimension much smaller than the height dimension of the filter.

[0025] For example, the travel of the lugs in the slots, projected along the axis of the M20 uprights, necessary for locking the filter 3 on the filter holder 2, is less than half the length dimension of an M20 upright of the first frame 20, for example less than or equal to ¼ of the length of the M20 upright.

[0026] The filter can be extracted, replaced with a short stroke following the direction of the uprights, in the collection enclosure of the well, which allows the integration of the filter system; even for a compact collection enclosure, with low clearance above the filter holder.

[0027] According to the present disclosure, said fixing means between the filter 3 and the holder 2 comprise a single pair of said lugs 4, preferably positioned at mid-height of the uprights M30 of said second frame 30 according to the first possibility, or at mid-height of the uprights M20 of the first frame 20 according to the second possibility. The lugs 4 of the pair are received in a removable manner in the slots 5 of a single pair of slots.

[0028] The slots 5 are also preferably received at mid-height of the uprights M20 of the first frame 20 of the filter holder 2 according to the first possibility, or at mid-height of the uprights M30 of the second frame 30 of the filter 3, according to the second possibility. By mid-height, it is meant that the two lugs 4 are positioned respectively in the middle of the two uprights M30 of the second frame 30 according to the first possibility or in the middle of the two uprights M20 of the first frame 20 according to the second possibility, or in a position close to the middle, between 25% and 75% of the height of the uprights M30 according to the first possibility (or of the uprights M20 according to the second possibility), or even preferably between 33% and 66% of the height of the upright.

[0029] According to the present disclosure, the attachment of the filter 3 to the filter holder 2 is ensured by a matching of only two lugs 4 respectively in the two slots 5. It becomes possible to place the filter on the filter holder, even if the plane of the first frame 20 and the plane of the second frame 30 are not perfectly parallel to each other when the lugs 4 are engaged in the slots 5. The installation is facilitated; in particular if the filter 3 is handled by a tool such as a pole by allowing the lugs 4 to be engaged in the slots 5, with a positioning tolerance in the engagement.

[0030] The filtering means 31 may comprise: a grid extending between the uprights M30 and crosspieces T30 of the second frame 30, and / or a flexible filtering medium, in particular in the form of a block which is pinched between the first frame 20 and the second frame 30 when the lugs 4 are blocked in the slots 5. Such a filtering medium may be synthetic, in particular comprise a non-woven fabric and / or may be chosen from the following techniques: lamellar, stainless steel grid fabric, nylon fabric, polyester, geotextile, human hair.

[0031] The second frame 30 may comprise on its inner periphery a peripheral groove inside which the filter medium is blocked. For example, the second frame may consist essentially of four semi-tubular profiles, with corner couple, placed end-to-end by their edge and fixed by their edge (for example welded) so as to form the uprights M30 and the crosspieces T30 of the second frame 30. Alternatively, a semi-tubular profile may, after making three notches, be folded at 90°, three times to form three corners of the frame with matching of two ends which are welded.

[0032] The peripheral groove receiving the edge of the filter media is formed by the cavity of the tubular profile bent at 90°, or by the extension of the cavities of the four tubular profiles placed end to end.

[0033] According to one embodiment, the filter holder comprises a peripheral wall 200, preferably flat, against which the filtering means 31 bears in a sealed manner on an inner periphery of the filtering medium, when the filter 3 and the filter holder 2 are fixed to each other by said fixing means when the lugs 4 are received in the slots 5. The peripheral wall 200 comprises a central opening 201 intended to be crossed by the water filtered by said filtering means 31. When the filter holder 2 is fixed to the side wall of the well, the central opening 201 is positioned opposite the mouth of the drainage pipe, preferably via a seal.

[0034] The slots 5 of the pair of slots are parallel to each other, and preferably inclined relative to the peripheral wall 200 of the first frame 20 according to the first possibility (illustrated), or even inclined relative to a plane of the second frame according to the second possibility (not illustrated), at least along two portions of length 50, respective of the two slots, called clamping slots. The slots each extend along a plane, perpendicular to the plane of the first frame 20 according to the first possibility or perpendicular to the plane of the second frame 30 according to the second possibility.

[0035] The clamping portions of length 50 cooperate with the lugs 4 to ensure the pressurization of the filtering means 31 on the periphery of the peripheral wall 200, with the creation of a seal between the peripheral wall 200 and an inner periphery of the filtering medium. In other words, the path of the lugs 4 in the two slots 5 ensures a bringing together of the second frame 30 and the first frame 20, by wedge effect, which ensures the pinching of the filtering medium, and the sealing of the periphery of the medium against the peripheral wall 200.

[0036] The angle of inclination α between the axis of each portion of clamping length 50 of the slots and the peripheral wall according to the first possibility (or along the plane of the second frame according to the second possibility) may be, for example, between 1° and 45°, for example between 3° and 25°.

[0037] According to one embodiment, the two portions of length 50 for clamping the slots 5 respectively have two local reductions 51 in thickness, of a dimension smaller than the lugs 4, ensuring the locking of the lugs in the slots and thus the locking of the filter to the filter holder.

[0038] For example at the figure 6 , and generally, the reduction in thickness can be obtained by half-round 53 or more generally a projection constituting a hard point to pass for the lug 4 during its path in the portion of clamping length 50 of the slot 5. This local reduction 51 can be the only element for blocking the filter in the filter holder, for the sake of simplification, namely in particular that the filter system is devoid of an upper blocking member such as a latch.

[0039] The half-round 53 (or more generally the projection) can be located on the same side of the slot as the side of the entrance of the slot 5, as illustrated in figures 6 Or 7 Alternatively, the half-round 53 (or more generally the projection) can be located on the opposite side, namely on the side opposite the entrance to the slot 5 (example not shown).

[0040] Generally speaking, this half-round 53 (or more generally the projection) can be made in one piece with the upright M20 of the first frame 20 of the filter holder 2 according to the first possibility, or even in one piece with the upright M30 of the second frame 30 of the filter 3 according to the second possibility, in particular when the upright M20 (or M30) is made of a material with a certain elasticity. Alternatively, the half-round 53 (or more generally the projection) can be constituted by an element added to the upright M20 according to the first possibility (or M30 according to the second possibility), and preferably in a metallic or other material, for example plastic, having greater elasticity than that of the upright M20 or M30.

[0041] Each clamping length portion 50 of the slots may be preceded by an entry portion 52, said entry portion extending lengthwise in a direction perpendicular to a plane of the first frame 20, as illustrated by way of example in figure 6 for the first possibility. This inlet portion 52 opens frontally onto the first frame 20 of the filter holder 2 to allow the entry of the lugs 5.

[0042] The input portion 52 may further be inclined in a direction inclined by an angle (theta) relative to the perpendicular direction of between 0° and 60°, for example between 0° and 45°, according to the first possibility and as illustrated in figure 7 .

[0043] The inlet portion 52 can also extend in a direction perpendicular to a plane of the second frame according to, or in a direction inclined at an angle relative to the perpendicular direction of between 0° and 60°, for example between 0° and 45° according to the second possibility (not illustrated).

[0044] The inlet portion 52 of each slot 5 has a preferably convergent shape, then is extended by the clamping portion. The inlet portion 52 and the clamping length portion 50 of the slot 5 form an elbow at their junction. The angle β centered on the elbow between the axis of the inlet portion 52 and the axis of the clamping length portion 50 is an obtuse angle preferably strictly greater than 90° and less than 135°.

[0045] According to one embodiment, the two uprights M20 of the first frame 20 of the filter holder comprise the two rising parts of the peripheral wall 200, as well as two guide walls 202, 203 extending in projection from the peripheral wall 200, in a manner parallel to each other, respectively carrying the two slots 5 of said single pair of slots according to the first possibility (or else respectively carrying the two lugs of said pair of lugs according to the second possibility). The inlet portions 52 of the slots 5 open respectively from two longitudinal edges of the guide walls 202, 203. These two guide walls are advantageously configured to cooperate in guiding with two opposite walls 302, 303 of the uprights M30 of said second frame 30 when fixing the filter 3 to the filter holder 2.

[0046] In other words, the two guide walls 202, 203 of the uprights of the first frame 20 carrying the two slots 5 advantageously ensure the guidance of the uprights M30 of the second frame 30 when the lugs 4 are inserted into the slots 5.

[0047] When the filter is fixed to the filter holder by locking the lugs in the slots, the filter, including its second frame 30 and the filtering means 31 can be entirely housed in the interspace between the two guide walls 202, 203. The height dimension of the guide walls 202, 203, in a direction perpendicular to the plane of the first frame 20 is greater than or equal to the thickness dimension of the uprights M30, in a direction perpendicular to the plane of the second frame 30.

[0048] According to one embodiment, the two guide walls 202, 203 extending in parallel over the entire height of the uprights M20 of the first frame 2, two crosspieces 20 can extend transversely, at the top and bottom of the first frame 20, including: the lower transverse portion of the peripheral wall 200, and a first transverse wall 204 connecting the lower parts of the two guide walls 202, 203 extending projecting from the peripheral wall, and the upper transverse portion of the peripheral wall 200 and a second transverse wall 205 connecting the upper parts of two guide walls 202, 203.

[0049] The first transverse wall 204 and the second transverse wall 205 may be substantially parallel to each other, and may be fixed by their ends respectively to the two guide walls 202, 203.

[0050] According to one embodiment, at least the second upper transverse wall 205 comprises a notch Ec providing access to a gripping means 32 on an upper crosspiece T30 of the second frame 30 of the filter.

[0051] Preferably, the first transverse wall 204 has the same notch Ec. The first transverse wall 204 and the second transverse wall 205 can be used indifferently as upper crosspiece and lower crosspiece, or vice versa. The filter holder does not have a particular mounting direction, which avoids installation errors.

[0052] For example, the gripping means 32 is a rider, forming a hollow housing for a nose of a pole. According to one embodiment, the first frame 20, including the peripheral wall 200, with its central opening 201, the guide walls 202, 203 of the uprights of the first frame carrying the slots 5 of said single one of the pair of slots according to the first possibility (or carrying the lugs according to the second possibility), or even the first transverse wall 204, bottom and the second transverse wall 205, top, are obtained by cutting and folding a single metal sheet. When the first frame 20 comprises the slots 5 according to the first possibility, the two slots 5 are obtained when cutting the metal sheet. Industrial application

[0053] These technical solutions can be applied in the field of rainwater filtration to equip manhole collection enclosures.

[0054] Also, the present disclosure further relates to a manhole comprising a collection enclosure comprising a side wall, a drainage pipe opening at an opening in the side wall, as well as a filter system, internal to the collection enclosure, opposite the opening, the first frame of the filter holder fixed to the side wall of said collection enclosure. List of reference signs

[0055] 1: Filter system, 2. Filter holder, 20. First frame, 200. Peripheral wall (flat), 201. Central opening, 202, 203. Guide wall, 204, 205. First transverse wall and second transverse wall 3. Filter, 30. Second frame, 31. Filter medium, 32. Gripping means, 302, 303. Opposite walls of the uprights (second frame), 4. Lugs, 5. Slots, 50. Clamping length portion, 51. Local reductions, 52. Inlet portions. Ec. Notch, M20, M30. Uprights of the first and second frame, T30. Crosspiece (second frame), Alpha. Angle between the axis of the clamping length portion of the slot and the peripheral wall (whichever is the first), Beta Angle between the axis of the entry portion of the slot and the clamping length portion Theta, Angle between the axis of the entry portion and the perpendicular to the plane of the first frame

Claims

1. Filter system (1), intended to be fitted to a side wall of a water collection enclosure such as a well or a pit through which a drainage pipe opens, said filter system being configured to filter the water from the collection enclosure flowing into the drainage pipe, the filter system comprising: - a filter holder (2) comprising a first frame (20) intended to be attached to the side wall of the well, - a filter (3) comprising a second frame (30), and a filtering means (31) held by the second frame (30), - means of attachment between the filter (3) and the filter holder (2) comprising -- according to a first possibility, lugs (4) carried by the second frame (30) protruding outwards from two uprights of the second frame (30), and slots (5) integral with the first frame (20), receiving the lugs (4) removably, or vice versa, -- according to a second possibility, lugs carried by the first frame protruding inwards from two uprights of the first frame, and slots integral with the second frame; receiving the lugs removably, and wherein said means for attachment between the filter and the filter holder include a single pair of said lugs (4), positioned at mid-height of the uprights (M30) of said second frame (30) according to the first possibility, or positioned at mid-height of the first frame (20) according to the second possibility, the lugs of the pair, removably received in the slots (5) of a single pair of slots, said slots received at mid-height of the uprights (M20) of the first frame (20) of the filter holder (2) according to the first possibility, or even received at mid-height of the uprights (M30) of the second frame (30) according to the second possibility, said means of attachment between the filter and the filter holder being configured so that the filter (3) is attached to the filter holder (2) by inserting the lugs (4) into the slots (5), said slots configured so that the insertion or extraction travel of the lugs (4) into the slots (5) to ensure the attachment of the filter to the filter holder, or, on the contrary, the extraction of the filter, is a dimension much lower than the height dimension of the filter, and wherein the first frame (20) of the filter holder includes a peripheral wall (200) against which the filtering means (31) rests on a circumference when the filter (3) and the filter holder (2) are attached to each other by said means of attachment, the lugs (4) received in the slots (5), the peripheral wall including a central opening (201) through which the water filtered by said filtering means (31) is intended to pass.

2. Filter system (1) according to Claim 1, wherein the slots (5) of the pair are parallel to each other, and inclined with respect to the peripheral wall of the first frame (20) according to the first possibility, or inclined with respect to a plane of the second frame (30) according to the second possibility, at least along two length portions (50), respectively, of the two, so-called clamping, slots, cooperating with the lugs to ensure that pressure is applied to the filtering means (31) around the circumference of the peripheral wall (200) by wedge effect.

3. Filter system (1) according to Claim 2, wherein the angle of inclination (α) between the axis of each clamping length portion of the slots and the peripheral wall according to the first possibility, or between the axis of each clamping length portion of the slots and the plane of the second frame (30) according to the second possibility is between 1° and 45°, for example between 3° and 25°.

4. Filter system (1) according to Claim 3, wherein the two clamping length portions (50) of the slots (5) respectively have two local reductions (51) in thickness, with a dimension smaller than the lugs, ensuring that the lugs are locked in the slots and the filter is locked in the filter holder.

5. Filter system (1) according to one of Claims 2 to 4, wherein each clamping length portion (50) of the slots is preceded by an entry portion (52), extending along a direction perpendicular to a plane of the first frame, or alternatively along a direction inclined at an angle (Thêta) relative to the perpendicular direction between 0° and 60°, for example between 0° and 45°, according to the first possibility, or alternatively extending along a direction perpendicular to a plane of the second frame, or alternatively along a direction inclined at an angle relative to the perpendicular direction between 0° and 60°, for example between 0° and 45° according to the second possibility, the entry portion (52) and the clamping length portion (50) of each slot (5) forming an elbow at their junction, the angle (β) centred on the elbow between the axis of the entry portion (52) and the axis of the clamping length portion (50) being an obtuse angle.

6. Filter system (1) according to Claim 5, wherein the entry portion (52) of each slot (5) has a convergent shape.

7. Filter system (1) according to one of Claims 1 to 6, wherein the two uprights (M20) of the first frame (20) of the filter holder comprise the two rising parts of the peripheral wall (200), as well as two guide walls (202, 203) protruding from the peripheral wall (200), parallel to each other, respectively carrying the two slots (5) of said single pair of slots according to the first possibility, or alternatively carrying respectively the two lugs of said pair of lugs according to the second possibility, the two guide walls cooperating for guiding with two opposite walls (302, 303) of the uprights (M30) of said second frame (30) when the filter (3) is attached to the filter holder (2).

8. Filter system (1) according to Claim 7, wherein the two guide walls (202, 203) extend parallel over the entire height of the uprights (M20) of the first frame (2), and wherein two cross members (T20) extend transversely, at the top and bottom of the first frame (20), including: - the lower transverse portion of the peripheral wall (200), and a first transverse wall (204) connecting the lower parts of the two guide walls (202, 203) protruding from the peripheral wall, and - the upper transverse portion of the peripheral wall (200) and a second transverse wall (205) connecting the upper parts of two guide walls (202, 203).

9. Filter system (1) according to Claim 8, wherein the second transverse wall (205) comprises a notch (Ec) providing access to a gripping means (32) on an upper cross member (T30) of the second frame (30) of the filter.

10. Filter system (1) according to either one of Claims 7 or 8, wherein the first frame (20), including the peripheral wall (200), the guide walls (202, 203) of the uprights of the first frame carrying the slots (5) of said single pair of slots according to the first possibility, or carrying the lugs according to the second possibility, or even the first lower transverse wall (204), and the second upper transverse wall (205) are obtained by cutting and bending a single piece of metal sheet.

11. Filter system according to one of Claims 1 to 10, wherein the filtering means (31) includes: - a grid extending between the uprights (M30) and cross members (T30) of the second frame 30, and / or - a flexible filtering media, in particular in the form of a block that is clamped between the first frame (20) and the second frame (30) when the lugs (4) are locked in the slots (5) which may be synthetic, in particular comprising a nonwoven and / or may be chosen from the following techniques: lamellar, stainless steel mesh, nylon mesh, polyester, geotextile, human hair.

12. Gully mouth comprising a collection enclosure comprising a side wall, a drainage pipe opening at an opening in the side wall, as well as a filter system according to one of Claims 1 to 11, internal to the collection enclosure, facing the opening, the first frame (20) of the filter holder (2) attached to the side wall of said collection enclosure.

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