EP1172307B1 - Refuse container for receiving a waste collecting flexible bag - Google Patents

Abstract

The waste bin comprises an outer container (1) and an internal bin (5), into which the bin liner fits. A sleeve (3) fits on the top of the outer container and is held in place by the rim (50) of the internal bin. The top edge of the liner is fitted over the rim of the internal bin and is held in a trough (30) in the sleeve by a collar (40) which fits over it.

Description

The present invention relates to a garbage collection bin, including a household trash can for collecting household waste.

We already know from the prior art many garbage cans this guy.

In its simplest form, such a bin includes a bucket can be closed by a cover. The user usually places a bag flexible waste receptacle, known as a “trash bag”, inside this bucket. he then fold the top edge of this bag over the top of the bucket, the bag being held in place only by the cover.

This type of bin has several disadvantages.

First, when the user removes the cover to deposit a heavy and / or bulky waste inside the garbage bag, the latter, which is not more held by the lid, is generally driven towards the bottom of the bucket, this which forces the user to replace it.

To overcome this drawback, we already know from the document WO 99/24332, a bin comprising a bucket, a bin bag and a lid, the upper edge of the garbage bag being folded outwards, over the rim from the bucket. This bin also includes a ring for fixing the bin bag. which is inserted between the bucket and the lid and which fits on the edge of the bucket by pinching and thus maintaining the upper part of the trash bag which whatever the position of the cover.

A similar device is disclosed in GB 2,046,694 where the bucket is replaced by a simple annular support of the bag intended to be fixed on a wall or the inside wall of a closet.

However, in these two devices of the prior art, the edge top of the trash bag protrudes around the entire outer periphery of the bucket, which is neither aesthetic nor hygienic.

Indeed, when using this type of trash, waste may fall and accumulate in folds in the upper part of the bag trash can, located outside the bucket. When the garbage bag is full and the user wants to remove it and close it using a link, he risks on the one hand drop on the ground, the waste accumulated in the crumpled upper part of the bag and on the other hand to put waste on your hands, which is both unpleasant and unhygienic.

Also known from WO 82/02701, a fireproof container for garbage bag, comprising a body in the form of rectangular parallelepiped and a hinged cover intended to close it. This body present on the inner periphery of its upper edge, a channel in "U", open upwards, intended to receive the upper edge of the garbage bag. A “U” fixing bracket is mounted inside this channel. It is articulated so to be able to pivot between a closed position in which it wedges the upper edge of the bag inside the canal and an open position in which it does not maintain plus the edge of the bag and thus allows the replacement of the latter.

This device makes it possible to fix the garbage bag. However, and as we can see in Figures 1 and 2 of this document, in use, waste can still accumulate on the top edge of the bag and inside the "U" channel. We then find the hygiene problems mentioned above.

We know from document DE-3 928 826, a dustbin having a hollow body provided with a gutter for receiving the upper edge of the trash bag, this gutter being closed by a cover. However, this trash is not intended to receive a bucket. The presence of such a bucket is practical in case bag breakage.

We also know from GB 2 339 676 a bin comprising a hollow body, a bucket, a bin bag and a lid.

Finally we know from document DE 9 314 268 U a bin according to the preamble of claim 1.

The invention aims to solve the problems mentioned previously and to provide a hygienic, aesthetic and also simple and convenient to use.

This goal is achieved using a trash can to receive a bag flexible waste collection, known as a “trash bag”.

• un corps creux,
• un seau présentant un rebord supérieur, par exemple roulé sur lui-même, tourné vers l'extérieur, ce seau étant destiné à être placé à l'intérieur dudit corps creux, et à recevoir le fond dudit sac poubelle,
• un couvercle articulé permettant d'obturer le corps creux,
• une collerette périphérique fixée sur le rebord supérieur de ce corps creux, qui a la forme d'une gouttière annulaire en forme de gorge qui est ouverte vers le haut et située le long de la périphérie du rebord supérieur dudit corps creux, cette gorge étant destinée à recevoir le bord supérieur du sac poubelle, et que :

• d'une part, elle comporte des moyens de maintien du bord supérieur du sac poubelle à l'intérieur de ladite gorge, ces moyens de maintien étant mobiles entre une première position dans laquelle ils maintiennent ledit bord à l'intérieur de ladite gorge et une deuxième position dans laquelle ils libèrent ce bord, ces moyens de maintien comprenant un cache obturant l'ouverture de ladite gorge de réception, de façon à définir un logement fermé recevant le bord supérieur dudit sac lorsque lesdits moyens de maintien sont dans la première position,
• d'autre part, le seau et adapté pour reposer et se positionner, par son rebord supérieur sur le chant de la paroi intérieure de ladite collerette.

This bin is remarkable in that it includes:

• a hollow body,
• a bucket having an upper rim, for example rolled on itself, facing outwards, this bucket being intended to be placed inside said hollow body, and to receive the bottom of said garbage bag,
• an articulated cover making it possible to close off the hollow body,
• a peripheral flange fixed on the upper edge of this hollow body, which has the shape of an annular groove in the form of a groove which is open upwards and situated along the periphery of the upper edge of said hollow body, this groove being intended to receive the upper edge of the garbage bag, and that:

• on the one hand, it comprises means for holding the upper edge of the garbage bag inside said groove, these holding means being movable between a first position in which they maintain said edge inside said groove and a second position in which they release this edge, these holding means comprising a cover closing the opening of said receiving groove, so as to define a closed housing receiving the upper edge of said bag when said holding means are in the first position,
• on the other hand, the bucket and adapted to rest and position, by its upper edge on the edge of the inner wall of said collar.

• le cache se prolonge sur au moins une partie de sa périphérie intérieure par au moins une jupe de protection, cette jupe s'étendant depuis ledit cache vers l'intérieur et le bas de la poubelle, en recouvrant au moins partiellement la face extérieure du bord intérieur de la gorge périphérique, le rebord supérieur du seau et la face intérieure supérieure du sac poubelle, lorsque lesdits moyens de maintien sont dans ladite première position ;
• les moyens de maintien du bord supérieur du sac poubelle comprennent des lamelles longitudinales, disposées sous le cache, séparées entre elles par des fentes verticales, ces lamelles étant destinées à pénétrer à l'intérieur de ladite gorge de réception du bord du sac poubelle, pour coincer ledit sac, et les fentes étant prévues pour coopérer avec des nervures verticales radiales s'étendant à l'intérieur de ladite gorge de réception ;
• la collerette périphérique est amovible ;
• les moyens de fixation de la collerette comprennent des doigts d'arrêt flexibles, aptes à coopérer avec le rebord supérieur dudit corps creux, roulé sur lui-même vers l'intérieur ;
• les moyens de maintien du bord supérieur du sac poubelle sont portés par un abattant articulé, constitué par un élément plat formant le cache, dont la forme correspond à celle de l'ouverture de la gorge de réception et sous lequel sont prévues lesdites lamelles longitudinales, séparées par les fentes ;
• le couvercle et l'abattant sont articulés autour d'un axe de rotation commun porté par la collerette ;
• le couvercle peut être ouvert par une commande à pédale ;
• le seau comporte une anse montée à l'extérieur de sa paroi latérale et les tourillons d'articulation de l'anse sont positionnés à l'intérieur du rebord supérieur du seau, à travers des perçages prévus dans la partie extérieure dudit rebord roulé.

According to other optional features of the invention:

• the cover extends over at least part of its inner periphery by at least one protective skirt, this skirt extending from said cover towards the inside and the bottom of the bin, at least partially covering the outside face of the edge inside the peripheral groove, the upper rim of the bucket and the upper internal face of the trash bag, when said holding means are in said first position;
• the means for holding the upper edge of the garbage bag comprise longitudinal strips, arranged under the cover, separated from each other by vertical slots, these strips being intended to penetrate inside said groove for receiving the edge of the waste bag, for wedging said bag, and the slots being provided to cooperate with radial vertical ribs extending inside said receiving groove;
• the peripheral collar is removable;
• the fixing means of the flange comprise flexible stop fingers, able to cooperate with the upper edge of said hollow body, rolled on itself towards the inside;
• the means for holding the upper edge of the garbage bag are carried by an articulated flap, constituted by a flat element forming the cover, the shape of which corresponds to that of the opening of the receiving groove and under which said longitudinal strips are provided, separated by the slots;
• the cover and the flap are articulated around a common axis of rotation carried by the flange;
• the cover can be opened by a foot control;
• the bucket has a handle mounted outside its side wall and the hinge pins of the handle are positioned inside the upper rim of the bucket, through holes provided in the outside of said rolled rim.

• une collerette périphérique amovible, en forme de gorge ouverte vers le haut, et qui, d'une part, est munie de moyens aptes à assurer sa fixation sur le rebord supérieur dudit corps creux et présentant à l'intérieur de ladite gorge, une série de nervures verticales radiales, et, d'autre part, possède une paroi intérieure dont le chant est adapté au positionnement du rebord supérieur d'un seau destiné à être placé à l'intérieur du corps creux et à recevoir le fond dudit sac poubelle,
• un abattant comprenant un élément plat formant un cache dont la forme correspond à celle de l'ouverture de la gorge de réception de ladite collerette et sous lequel sont prévues des lamelles longitudinales séparées par des fentes, les lamelles étant destinées à pénétrer dans la gorge et les fentes à chevaucher les nervures verticales radiales de ladite collerette, et
• un couvercle,
  ces trois éléments étant articulés autour d'un axe de rotation commun.

The invention also relates to an assembly for closing off a hollow body intended to receive a flexible waste collection bag, known as a “trash bag”, comprising:

• a removable peripheral flange, in the form of a groove open upwards, and which, on the one hand, is provided with means capable of ensuring its attachment to the upper edge of said hollow body and having, inside said groove, a series radial vertical ribs, and, on the other hand, has an inner wall whose edge is adapted to the positioning of the upper edge of a bucket intended to be placed inside the hollow body and to receive the bottom of said garbage bag,
• a flap comprising a flat element forming a cover, the shape of which corresponds to that of the opening of the receiving groove of said flange and under which are provided longitudinal strips separated by slots, the strips being intended to penetrate into the groove and the slots to overlap the radial vertical ribs of said flange, and
• a lid,
  these three elements being articulated around a common axis of rotation.

• la figure 1 est une vue en coupe longitudinale de la poubelle selon l'invention,
• la figure 2 est une vue similaire à la figure 1 mais dans laquelle le couvercle et l'abattant de la poubelle sont légèrement ouverts ;
• la figure 3 est une vue éclatée, en coupe radiale de la collerette et de l'abattant de la poubelle selon l'invention ;
• la figure 4 est une vue de détail, agrandie, d'une partie de la figure 1 sur laquelle on a représenté le sac de collecte des ordures ;
• la figure 5 est une vue partielle, en perspective, du seau ; et
• la figure 6 est une vue en perspective d'une partie du couvercle, de la collerette et de l'abattant, au niveau de la charnière d'articulation du couvercle et de l'abattant, dans laquelle une partie de l'abattant a été tronquée.

The invention will be better understood on reading the following description of an embodiment of the invention given by way of illustrative and nonlimiting example, this description being made with reference to the accompanying drawings in which:

• FIG. 1 is a view in longitudinal section of the bin according to the invention,
• Figure 2 is a view similar to Figure 1 but in which the lid and the flap of the bin are slightly open;
• Figure 3 is an exploded view, in radial section of the flange and the flap of the bin according to the invention;
• Figure 4 is an enlarged detail view of part of Figure 1 in which there is shown the garbage collection bag;
• Figure 5 is a partial perspective view of the bucket; and
• FIG. 6 is a perspective view of part of the cover, of the flange and of the flap, at the level of the hinge of articulation of the cover and of the flap, in which a part of the flap has been truncated.

In the following description and claims, the terms "Top", "bottom", "upper", "lower", "vertical" or "horizontal" make reference to the normal vertical position of use of the bin.

As illustrated in Figures 1 and 2, the bin according to the invention includes a hollow body 1, a cover 2, a flange 3, a flap 4 and a bucket 5.

As illustrated in Figure 4, this bin is intended to receive a flexible bag 6 for collecting waste, referred to as a “trash bag” in the rest of the description and claims, generally made of plastic such than polyethylene.

As illustrated in FIG. 2, the hollow body 1 is a cylinder open to its two ends, preferably made of metal or possibly of material rigid plastic.

Its lower end is completely closed by a bottom 10 circular or partially by a simple ring open at its center.

Its upper edge 11 is rolled on itself towards the inside of said body, so as to form a bulge capable of cooperating with the collar 3, as this will be described in more detail later.

The cylindrical body 1 can be closed by the cover 2 in the form circular having a peripheral rim 20. This cover is generally made of the same material as the hollow body 1.

This cover 2 is articulated using a hinge 21 (which appears better in FIG. 6), around an axis of rotation 210. Conventionally, the hinge 21 comprises two flanges 211, 211 ', arranged at the two ends of the axis 210, this the latter being supported by the collar 3, in a manner which will be described later.

The bin also advantageously includes a handle handling 7, consisting of a metal wire whose two ends are folded respectively inside the two ends of the axis 210.

The hinged cover 2 is capable of occupying a closed position (see Figure 1), in which it seals the upper part of the bin and a open position at a greater or lesser angle (see Figure 2), in which it allows the user to access the interior of the bin to deposit their waste.

In the embodiment of the invention shown in these two figures, the lid 2 is opened using a pedal control 12 and associated rods 13, 13 ′. This device for opening the lid is known skilled in the art and will therefore not be described further.

In addition, advantageously, the opening of the lid can be carried out with a device such as that described in document NL 1 005 057. In this case (see Figure 6), the hinge 21 has further a central wing 212, integrally formed with said hinge, extending substantially perpendicular to the surface of the cover 2, between the two flanges 211, 211 '. This wing 212 has an orifice 213 in the form of a banana, in which is introduced the end of the rod 13 '. This device allows the user, as described in document NL 1 005 057, open the cover 2 according to a angle less than 90 °, by pressing the foot on the pedal 12 or at an angle greater than 90 °, using the hand.

In other variant embodiments not shown on the Figures, the cover 2 can be opened simply by hand. he can can also be opened by a command actuated by the opening of a door of the cupboard when the bin is placed inside a cupboard. In these two cases, the pedal 12 and the rods 13, 13 ′ are then eliminated.

According to the remarkable features of the invention, the bin includes a flange 3 cooperating with a flap 4, these two parts being advantageously made of polypropylene.

As illustrated in FIGS. 3, 4 and 6, the flange 3 is a annular gutter in the form of a channel or groove 30 intended to receive the edge top of trash bag 6.

This groove 30 is open upwards and has a section in "V", however it could also have another form, in "U" by example. More specifically, it has a bottom 31, a vertical inner wall 32 and an outer wall 33, flared upwards.

This flange 3 has fixing means on the hollow body 1. These means consist of several stop fingers 34 (see FIGS. 3 and 4), uniformly distributed outside the groove 30, on the underside of the bottom 31. These stop fingers 34 have a concave part 340, open towards the outside, designed to cooperate with the upper edge 11 of the hollow body. The fact that the collar 3 is made of plastic material gives sufficient elasticity to fingers 34 to allow "clip" said collar on the upper edge 11 of the hollow body 1.

The collar 3 is also provided with several ribs 35, vertical, radial, uniformly distributed inside the groove 30.

As illustrated in FIGS. 3 and 6, the flange 3 also has two flanges 36, 36 ', intended to hold the axis of rotation 210 of the cover 2. The two flanges 36, respectively 36 ′ are arranged outside the two flanges 211, respectively 211 ', parallel to these.

When the cover 2 is closed, its rim 20 rests on the edge 330 of the outer wall 33 of the groove.

As illustrated in Figures 3 and 6, the flap 4 has the shape of a annular gutter, open at the bottom and having in cross-section the shape of a "U". More specifically, the flap 4 comprises a substantially planar annular part 40 forming a cover, an interior side wall or skirt 41, substantially vertical, extending downwards and an outer side wall 42, lower than the skirt 41.

In addition, the flap 4 has a rib 43 in the form of a cylinder, extending vertically downwards from the underside of the cover 40. This cylinder 43 has a plurality of vertical slots 44, distributed regularly over its periphery and defining between them lamellae 45 in an arc. As illustrated in FIG. 3, these slots 44 extend from the lower edge of the cylinder 43, substantially up to half the height thereof.

As illustrated in Figures 3 and in particular 6, the flap 4 is articulated around the axis of rotation 210, carried by the flange 3. For this purpose, it has two parallel flanges 46, 46 ', extending from the base of the outer side wall 42. These two flanges 46, 46 ′ are positioned respectively at the two ends of the axis of rotation 210, in the vicinity of the flanges 211, 211 ′ of the cover 2. As illustrated in FIG. 6, there is therefore successively from the outside towards the axis of rotation 210, the flange 36, (respectively 36 ') of the collar 3, the flange 211, (respectively 211 ') of the cover 2 and the flange 46, (respectively 46 ') of the flap 4.

The cover 2 and the flap 4 are therefore articulated around an axis of common rotation 210, carried by the collar 3.

As illustrated in FIG. 6, two slots 47, 47 ′ are provided in the outer side wall 42 and in a part of the cover 40, for the passage of two flanges 211, 211 'of the hinge 21 of the cover.

A cutout 48 is also made in the side wall outside 42 and in a part of the cover 40, between the two slots 47 and 47 ′, for the passage of the central wing 212 of the cover 2.

Finally, as can be seen in Figure 3, a gripping member 49, such as a tongue, is provided on the flap 4, at the base of the side wall outside 42, in a position diametrically opposite to that of the cutout 48 and of the hinge pin 210. This tongue 49 allows the user to lift more easily the flap 4, as illustrated in Figure 2.

In order to receive this grip tab 49, when the flap 4 rests on the collar 3, (see Figures 3 and 4), a cutout 37 is provided on the edge 330 of the outer wall 33 of the flange 3, facing said tongue grip 49.

Finally, the bin according to the invention advantageously comprises a bucket 5, made of metal or plastic, intended to collect waste or liquid flows in case of bag rupture 6. In addition, this bucket isolates the bag 6 of the mechanism for opening the cover 2 with a pedal, when the latter is present.

The bucket 5 is cylindrical. As illustrated in Figure 5, the rim upper 50 of the bucket is rolled on itself, outwards. This flange 50 allows to position the bucket 5 on the edge 320 of the inner wall 32 of the collar 3.

This bucket 5 has a handle 51, external to the bucket, which allows do not interfere with the introduction of bag 6 into the trash.

The hinge pins 52 of the handle 51 are positioned at the inside of the rim 50 rolled on itself, through holes 53, provided for this effect in the outer part of the rim 50. Thus, the bag 6 is not likely to get tear on the pins during its installation, since these are hidden.

The assembly and use of the bin according to the invention will now be explained in detail.

First of all, note that the cover 2, the flap 4 and the flange 3, connected together via the axis of rotation 210 constitute a sub-assembly independent, can be removed from the body 1 for cleaning inside of it.

During normal use of the bin, the flange 3 is "Clipped" onto the hollow body 1, by means of the cooperating stop fingers 34 with the upper edge 11 of said body.

The user opens the cover 2 and lifts the flap 4 (see figure 2), then he introduces the bucket 5 inside the body 1, so that the flange 50 of said bucket rests on the edge 320 of the inner wall 32 of the collar 3.

He then places the bag 6 as illustrated in FIG. 4, so that the upper edge of the bag is in the receiving groove 30 of the collar 3 and the bottom of the bag is in the bucket 5.

The user then folds the flap 4 over the flange 3, in the position illustrated in Figures 1, 4 and 6. In this position, the slats longitudinal 45 are placed in the "V" groove 30 and the slots 44 come overlap the radial ribs 35. These elements constitute the means of maintaining the upper edge of the trash bag 6.

In this position, and as can be seen in Figure 6, the base of the outer wall 42 of the flap 4 rests at the top of the inner surface of the outer wall 33 of the collar 3. This allows the rim 20 of the cover 2 to rest on the edge 330 of the outer wall 33 when the cover is closed.

In addition, the flat annular part 40 or cover of the flap 4 closes the opening of the “V” groove 30. The flap 4 and the collar 3 therefore constitute a closed housing for receiving the upper edge of the trash bag 6, when the flap 4 is in the closed position. This therefore not only maintains the edge of the bag 6 to prevent the latter from going down inside the bucket 5, but also to avoid waste being deposited on the upper edge of the bag 6 in defiling this one.

Always in the closed position of the flap 4, and as illustrated in Figure 4, we can see that the skirt 41 covers the top of the inner wall 32 of the collar 3, the rim 50 of the bucket 5 and the upper part of the bag 6.

The height of this skirt 41 can be increased to protect more the top of the trash bag 6. This skirt 41 can also be slightly simultaneously tilted down and inside the bin, to present a funnel shape and guide the waste to the center of the trash bag 6.

When the bag 6 is full, the user just has to open the cover 2, to lift the flap 4 and remove the trash bag 6 that he can easily take without risking getting your hands dirty.

Thanks to these characteristics of the invention, a trash can is obtained aesthetic and hygienic.

In all of the above description, the trash can has been described as having a cylindrical body and bucket and a lid, a flap and a circular flange. However, it is obvious that such a bin could perfectly have another shape, for example a parallelepiped shape rectangle, the skilled person can then adapt the shapes of the different components of this bin.

Claims (10)

1. A dust bin for receiving a flexible bag (6) for collecting waste, referred to as "bin liner", the dust bin comprising:

   a hollow body (1);

   a hinged lid (2) enabling the hollow body (1) to be closed;

   a peripheral collar (3) fixed to the top rim of the hollow body (1), the collar being in the form of an upwardly-open annular gutter in the form of a trough (30) situated around the periphery of the top rim (11) of said hollow body, said trough being designed to receive the top margin of the bin liner (6); and

   holding means (4) for holding the top margin of the bin liner inside said trough (30), said holding means (4) being movable between a first position in which they hold said margin inside said trough (30) and a second position in which they release said margin, the holding means (4) comprising a mask (40) closing the opening of said margin-receiving trough (30) so as to define a closed housing that receives the top margin of said bin liner (6) when said holding means (4) are in the first position,

      the dust bin being characterized in that it also comprises a bucket (5) presenting a top rim (50), e.g. rolled over outwards, said bucket being for placing inside said hollow body (1) and receiving the bottom of said bin liner (6), the bucket (5) being adapted to rest and position itself via its top rim (50) on the top edge face (320) of the inner wall (32) of said collar (3).
2. A dust bin according to claim 1, characterized in that the mask (40) is extended over at least a portion of its inner periphery by at least one protective skirt (41), said skirt (41) extending, when said holding means (4) are in said first position, from said mask (40) towards the inside and the bottom of the dust bin, covering at least partially the outside face of the inner wall (32) of the peripheral gutter (30), the top rim (50) of the bucket (5), and the top inside face of the bin liner (6).
3. A dust bin according to claim 1 or claim 2, characterized in that the holding means (4) for holding the top margin of the bin liner (6) comprise longitudinal blades (45) disposed beneath the mask (40) and separated from one another by vertical slots (44), the blades (45) being designed to penetrate into said trough (30) for receiving the margin of the bin liner in order to wedge said bin liner, and the slots (44) being provided to co-operate with radial vertical splines (35) extending inside said margin-receiving trough.
4. A dust bin according to any one of claims 1 to 3, characterized in that peripheral collar (3) is removable.
5. A dust bin according to claim 4, characterized in that the fixing means (34) for the collar comprise flexible stop fingers suitable for co-operating with the top rim (11) of said hollow body, said rim being rolled over towards the inside.
6. A dust bin according to claim 3, characterized in that the holding means (4) for holding the top margin of the bin liner are carried by a hinged flap constituted by a mask-forming flat element (40) of a shape that corresponds to the shape of the opening of the margin-receiving trough (30), and beneath which said longitudinal blades (45) are provided, separated by the slots (44).
7. A dust bin according to claim 6, characterized in that the cover (2) and the flap (4) are hinged about a common pivot axis (210) carried by the collar (3).
8. A dust bin according to any one of claims 1 to 7, characterized in that the cover (2) can be opened by a pedal control (12, 13, 13').
9. A dust bin according to any one of claims 1 to 8, characterized in that the bucket (5) has a handle (51) mounted outside its side wall and in that the pivot pins (52) of the handle are positioned inside the top rim (50) of the bucket (5) passing through holes (53) provided in the outside portion of said rolled-over rim.
10. An assembly for closing a hollow body (1) designed to receive a flexible bag (6) for collecting waste, referred to as a "bin liner", the assembly comprising:

    a removable peripheral collar (3) in the form of an upwardly-open trough (30) which firstly is provided with means (34) suitable for enabling it to be fixed to the top rim (11) of said hollow body (1) and presenting inside said trough, a series of radial vertical splines (35), and secondly possesses an inside wall (32) whose top edge face (320) is adapted to positioning the top rim (50) of a bucket (5) for placing inside the hollow body (1) and for receiving the bottom of said bin liner (6);

    a flat (4) comprising a mask-forming flat element (40) of shape corresponding to the shape of the opening of the trough (30) of said collar (3), and beneath which there are provided longitudinal blades (45) separated by slots (44), the blades (45) being designed to penetrate into the trough (30) and the slots (44) being designed to fit over the radial vertical splines (35) of said collar (3); and

    a cover (2);

       said three elements being hinged together about a common pivot axis (210).

Images