EP2151227B1 - Massage head and massage device using such a head - Google Patents

Description

FIELD OF THE INVENTION

The present invention relates in the first place to a massage head, intended for the mobilization of cutaneous tissue. It then relates to a massage apparatus using such a head.

The aim of the invention is the simple and effective way of performing massage operations on both humans and animals.

PRIOR STATE OF THE TECHNIQUE

Different massage techniques are known, generally depending on the treatments to be performed. In general, they are intended to exert on the patient stresses using phenomena of pressure and / or displacement and / or pinching including skin tissue.

In order to facilitate the action of the massager, a large number of devices have been proposed. Among these it was first proposed the implementation of devices using a simple mechanical action, for example by means of assemblies comprising balls or balls mounted on a support housing, where appropriate to distribute or to apply concomitantly a treatment product of the cream or gel type, as for example described in the document FR-A-1,225,094 .

It has also been proposed to associate with this mechanical treatment a suction treatment of the patient's skin. For this purpose, the massage devices in question use a treatment head connected to a suction circuit, said treatment head being constituted by a housing defining an internal chamber inside which opens the suction circuit. . When the massage head is applied against the body of the patient, and because of the suction generated by the suction circuit, a skin fold is formed inside the internal chamber, skin fold which leans against the peripheral edge of said inner chamber.

The mechanical action as for it can be exerted by rollers, or balls which make it possible to exercise concomitantly with the suction on the body of the patient an action of pressure and / or displacement and / or friction, in particular by vibration .

The solutions proposed in this context lead to complex sets that are difficult to implement and which are not entirely satisfactory in terms of results.

It has also been proposed massage devices that can easily reproduce massage type palpate / roll, that is to say, to exercise on the patient a continuous action, causing not only pinching localized skin tissue, but also a progressive displacement of the pinched zone so as to cause rolling of said skin fold and this while exerting pressure (see for example EP-A-224,422 ).

Thus, such devices comprise a manually operable housing inside which are mounted two parallel rollers, mounted free in rotation or positively rotated within the housing. These rollers can be mounted on the fixed-spaced housing, or on the contrary are capable of being able to move away and approach each other automatically during the massage operation, said housing being itself connected to suction means for creating a depression between said rollers when the head provided with these different elements is applied against the body of the patient, so as to form a skin fold bearing against the surfaces of the rollers.

In the document EP 0 917 452 it has been proposed to replace the rollers in question by two partitions attached to the interior of the housing, articulated within the latter so as to be able to be driven in a pivoting movement, said housing being again connected to a source suction. Under the action of the suction, it creates a skin fold being inserted between the two partitions inside the housing. Due to the progression in one direction or the other of the massage head provided with such a device against the skin of the patient, the skin fold thus formed undergoes a jerky pinch.

This device can be improved by the implementation of a solenoid valve at the suction circuit, which provides an all-or-nothing operation, but which also allows to define a controlled flow rate of the air flow between two determined values, with the possibility of adjustment between said values.

Such a solenoid valve mounted on the suction circuit thus makes it possible to obtain a sequential operation of rhythm pulsation, such that during the massage operation, the suction rate varies cyclically, thus causing a cooling effect. vibration, variation of the suction force and skin grip, thus improving the effectiveness of the treatment and further facilitating its implementation.

In the absence of stress, the two partitions are held apart from each other for example by means of springs or magnets, the pivoting of said partitions and thus the approximation of one with respect to the other resulting the effect of vacuum and / or depression generated inside the housing.

While the device described in this document is undoubtedly satisfactory, it turns out that because of the unavoidable leaks between the lower edge of the housing and the skin of the patient against which it is applied, the vacuum or depression may be broken quickly, thereby affecting the effectiveness of the treatment and in particular the pinching action resulting from the two partitions.

In addition, it is not uncommon that due to the vacuum, there is a jamming of one or both walls, then affecting more importantly the effectiveness of the treatment.

The objective of the present invention is to optimize the operation of the device described in this document and in particular the efficiency of the nip resulting from the action of said partitions.

SUMMARY OF THE INVENTION

For this purpose, the present invention claimed is a massage head provided with a housing defining an inner chamber at which a skin fold is formed when it is applied to the skin of a patient, said fold being supported against the lower edges of the chamber. This chamber is defined by two side walls and two transverse walls, said transverse walls each being constituted by a valve capable of being driven by a pivoting movement, so as to induce the bringing together and the removal of the lower edges said valves in contact with the skin fold.

According to the invention, the relative displacement of the valve is ensured by means of a motorized rotary cam arranged within the massage head, said cam defining a cam path receiving a ball joint attached to the end of the valves, opposite their lower edge free in contact with the patient's skin.

In other words, the invention consists first of all, in replacing the suction source in its function of displacement of the transverse flaps or partitions by a purely motorized action resulting from the cooperation of members mounted on said partitions with a cam rotary, whose cam path has at least one eccentric.

The skin fold thus results from the mechanical catch generated by the free bottom edge of the valves. This is advantageously coated with a material with a high coefficient of friction, such as, for example, elastomer.

In doing so, we effectively reproduce the technology called "Jacquet pinch", consisting of a series of pressures throughout the depth of the skin and in all directions.

The implementation of the mechanical actuation of the valves to achieve this skinfold has the advantage of ensuring the return of the valves to their original position, unlike devices of the prior art implementing only the suction, which can result in the "gluing" of said flaps between them, canceling any action of the massage head.

According to the invention, the cam has only one cam path for the two ball joints of the two valves. As already said, this cam path is not circular, but has at least one eccentric. However, this cam path is symmetrical to induce a rapprochement or on the contrary a simultaneous and concomitant removal of the lower free edges of said valves.

This cam path may be ellipsoidal but may also adopt a substantially star-shaped profile and in general any symmetrical profile, a function of the desired number of operations of approaching and moving the lower free edges of the valves by full rotation of said cam.

According to one characteristic of the invention, the ball joints received within the cam path are mounted at the end of an axis integral with the valves.

In addition, the end of the valves opposite their free bottom edge is articulated at a support of the valves to allow their pivoting precisely and in particular the movement of the lower edges free approaching and moving away from each other .

This articulation can result from an elastic hinge.

The support assembly of the valves and the valves themselves may consist of a one-piece plastic part.

• d'un support de clapets, solidarisé à ladite tête, et comportant deux embases rigides articulées sur ledit support, lesdites embases se prolongeant dans la direction opposée au bord libre des clapets par un organe apte à coopérer avec la came rotative ;
• d'une partie active, venant s'emmancher sur l'autre extrémité des embases, et destinée à venir en contact avec la peau.

According to a variant of the invention, the active zone of the massage head consists of:

• a valve support, secured to said head, and having two rigid bases articulated on said support, said bases extending in the opposite direction to the free edge of the valves by a member adapted to cooperate with the rotary cam;
• an active part, coming to slip on the other end of the bases, and intended to come into contact with the skin.

This variant firstly makes it possible to simplify the production of the massage head of the invention. Indeed, the support of the valves with its two bases can be monobloc, and in particular made of plastic, and providing a thinned area to form hinge. In addition, it allows to modulate the active part, in terms of geometric shape, in addition to the nature of the material that constitutes it, such as flexible material, abrasive, fragrant, cold effect. Such a material may for example consist of polypropylene, polyethylene or polyurethane.

According to a more advanced variant of the invention, it is possible to add an additional degree of freedom for the displacement of the valves, constituted in this case by a displacement of the latter according to the main dimension of the massage head.

For this purpose, the valves are each provided with a light oriented along their main dimension, and extending at their upper zone, said light cooperating with a perpendicular axis emanating from the support of the valves.

In addition, said valves are each subjected to the action of an elastic return member, in this case constituted by a spring, inducing their positioning, in the absence of any stress, in the up position, that is, that is, inducing the positioning of the ball joints against the rotating cam.

In doing so, the action of the massage head is optimized, making any use of a conventional suction source unnecessary. Moreover, due to this "vertical" additional movement of the valves, a "lifting" effect is induced, these inducing when closed, besides the pinching, also the traction of the skin fold. This leads to the optimization of the treatment of the skin in terms of elasticity, tone and firmness of the skin.

According to another variant of the invention, it may however be envisaged to associate with the massage head the conventional suction means known from the prior art, the suction duct opening into the internal chamber. In this hypothesis, it improves or facilitates the formation of the skin fold, and above all, it has the ability to act in a combined manner by exerting a suction action continuous or not with a rhythmic massage action and therefore discreet, born the action of the motorized valves. This combination of effects, that the respective opening and closing frequencies of the valves, and aspiration phase, synchronous or not, optimizes the process of blood and lymphatic circulation.

The invention also relates to a massage device implementing such a massage head. This massage device comprises a source of electrical energy adapted to actuate the electric motor integrated in the massage head and ensuring the rotation of the cam. It is also likely to include a source of vacuum or depression associated with the massage head when it is provided.

BRIEF DESCRIPTION OF THE FIGURES

• La figure 1 est une représentation schématique en perspective en éclaté de la tête de massage conforme à l'invention.
• La figure 2 est une représentation schématique également en éclaté de tête de massage vue en section sagittale.
• La figure 3 est une représentation schématique en section sagittale de la tête de massage assemblée conformément à l'invention, les clapets dont elle est munie étant en position éloignée l'un de l'autre.
• La figure 4 est une vue analogue à la figure 3 mais dans laquelle les clapets sont en position rapprochée l'un de l'autre.
• La figure 5 est une représentation schématique en perspective des clapets caractéristiques de l'invention.
• La figure 6 est une représentation schématique vue de dessus de la came conforme à l'invention selon une première forme de réalisation.
• La figure 7 est une vue analogue à la précédente selon une seconde forme de réalisation.
• Les figures 8a et 8b sont des représentations schématiques en section d'une variante évoluée de l'invention, permettant de conférer auxdits clapets un degré de liberté supplémentaire.
• Les figures 9a à 9d illustrent différents phases de rotation de la came et de son action sur les clapets, dans le cadre de la version plus évoluée de l'invention visée au sein des figures 8a et 8b.
• Les figures 10a à 10d sont des représentations schématiques des quatre phases précédentes vue de dessus.
• La figure 11 est une vue schématique en perspective éclatée d'une variante de réalisation de l'invention.
• Les figures 12a et 12b sont des représentations schématiques vue de côté de deux modes de réalisation de cette variante.

The manner in which the invention can be realized and the advantages which result therefrom will emerge more clearly from the exemplary embodiment which follows, given by way of non-limiting indication, in support of the appended figures:

• The figure 1 is a schematic perspective exploded representation of the massage head according to the invention.
• The figure 2 is a schematic representation also exploded of massage head seen in sagittal section.
• The figure 3 is a schematic representation in sagittal section of the massage head assembled in accordance with the invention, the valves of which it is provided being in a position remote from each other.
• The figure 4 is a view similar to the figure 3 but in which the valves are in the close position of one another.
• The figure 5 is a schematic representation in perspective of the characteristic valves of the invention.
• The figure 6 is a schematic representation seen from above of the cam according to the invention according to a first embodiment.
• The figure 7 is a view similar to the previous one according to a second embodiment.
• The Figures 8a and 8b are diagrammatic representations in section of an advanced variant of the invention, for giving said valves an additional degree of freedom.
• The Figures 9a to 9d illustrate different phases of rotation of the cam and its action on the valves, in the context of the more advanced version of the invention referred to within the Figures 8a and 8b .
• The Figures 10a to 10d are schematic representations of the four preceding phases seen from above.
• The figure 11 is a schematic perspective exploded view of an alternative embodiment of the invention.
• The Figures 12a and 12b are schematic side views of two embodiments of this variant.

DETAILED DESCRIPTION OF THE INVENTION

So we illustrated in relation to the figure 1 an exploded schematic representation of the massage head 1 according to the invention.

This comprises a housing consisting of two parts 2, 11 assembled with each other by snapping, gluing or screwing, made for example of plastic (and for example POM (polyoxymethylene), ABS or polycarbonate for the part posterior 2 , and polycarbonate, especially transparent to the front portion 11 ), and defining a volume within which are received the mechanical elements ensuring the operation of the head.

This housing also acts as a grip handle by the user to allow the application of the massage head against the body of a patient.

The rear portion 2 of said housing is provided with an opening opening extending through a channel 13 , at which is likely to fit a pipe 3 connected to a source of vacuum or depression when the massage device putting in the head 1 is equipped with it.

The front portion 11 of this housing defines an internal chamber and receives an assembly 12 incorporating two valves 15 and 16 pivotable about an axis perpendicular to the main dimension of the head, so that their free lower edge 17 , 18 approach or move away from each other, as will be described in more detail later.

The rear part 2 thus defines an internal volume within which is first intended to be received an electric motor 4 , fixed on the inner side wall of said portion by means of a fixing plate 6 screwed into slots 34 formed within said wall. This plate 6 is pierced at its center with a through hole allowing the passage of the axis of rotation 5 from the motor 4 , and intended to ensure the rotation of a cam 10 , again described in more detail later.

The electric motor used may be of the DC or brushless type. It is associated with a reducer, in order to have the necessary torque to actuate the valves. When a brushless motor is used, it can advantageously be added an encoder, to manage the output speed of the motor shaft and corollary, the beat frequency of the valves.

Said plate 6 is also fixed to the lower end of the engine 4 by additional screws 8 .

The rotary axis 5 of the electric motor 4 is received and adhered in a recess 14 formed in a plate 9 fixed by means of screws to the rear face of the rotary cam 10 .

The rotary cam 10 is guided by adjustment within the body 2.

The anterior face of the cam defines a cam path 30 intended to cooperate with appropriate means associated with the valves 15 and 16, as described in more detail below.

Said cam 10 is pierced at its center with a through pipe 29 , coaxial with its axis of rotation, and intended to allow the passage of a fastening means of the assembly 12 incorporating said valves and in particular a caudron or bulge.

This cam 10 is advantageously made of plastic by injection molding, and typically POM, to ensure its mechanical characteristics, especially in terms of guiding, friction and wear.

The inner chamber defined by the front portion 11 of the housing constituting the massage head comprises two opposite side walls to one another 28 and the two valves 15 and 16 integrated in the assembly 12 .

This assembly 12 comprises a caudron type fixing system described above associated with a platform 21 , also provided with a through orifice 22 , collinear and coaxial with the caudron and with the through pipe 29 formed within the cam 10 . Said valves 15 and 16 are in fact articulated by their upper end opposite the free edges 17 and 18 at this platform 21 , as can be observed on the figure 5 . This articulation may advantageously consist of an elastic hinge of a type known per se.

In addition, said upper end of the valves 15 and 16 opposite the lower free edges 17 and 18 are each extended by an axis 25 and 26 , perpendicular to the axis of articulation of said valves on the platform 21 , and whose end free is provided with a ball 27 respectively 28 , intended to cooperate with the cam path 30 formed within the cam 10 .

Advantageously, the assembly consisting of the two valves, the platform 21 , the axes 25 and 26 and the balls 27 and 28 is made of plastic and constitutes a single piece. In any event, each of the axes 25 and 26 is rigidly secured to the valve associated therewith, so as to induce its displacement relative to the axis of articulation of the latter, according to the path of the corresponding ball joint 27 and 28 in the cam path 30 .

The free bottom edge 17 and 18 of the valves 15 and 16 is advantageously of convex shape, in order to promote contact with the skin of the patient. Moreover, said valves, when they are in a position distant from each other, as for example represented on the figure 3 , bear against the anterior end of the front portion 11 of the casing of the massage head and have a shoulder 19 and 20 respectively .

Because of the articulation 23 and 24 of the valves on the platform 21 , it is therefore conceivable that the valves 15 and 16 are likely to be moved closer to or away from each other within the internal chamber defined by the front portion 11 of the housing, this displacement occurring in a plane parallel to the side walls 28 also defining the internal chamber of the massage head.

According to the invention, the cam path 30 of the cam 10 has a symmetry with respect to at least one axis passing through the plane in which it is inscribed and by the center of rotation of said cam. It also has at least one eccentric. In the embodiment shown in figure 6 this cam path is ellipsoidal in shape. In doing so, the ball joints 27 and 28 of the two valves 15 and 16 follow exactly a profile symmetrical to one another with respect to a plane passing through the axis of rotation of the cam on the one hand and perpendicular to the side walls. 28. With the ellipsoidal profile represented in figure 6 each 360 ° rotation of the cam 10 in fact induces two beats of each of the two valves.

However, this cam path can adopt other profiles, always symmetrical and for example a profile of the type of that of the figure 7 . In this configuration, each rotation of the cam 10 from 360 ° induces four beats of each of the valves.

It is thus conceived that by adapting the speed of rotation of the motor 4 , and therefore of the cam 10 , the speed and the number of beats of said valves can be selected, and thus the intensity of the treatment and in particular of the nip generated by the valves. .

Therefore, we significantly optimize the effectiveness of this pinch action.

According to an advantageous version of the invention, and more particularly described in connection with the Figures 8 to 10 Valves 15 and 16 are given an additional degree of freedom, consisting of a vertical displacement (in said figures) thereof.

For this purpose, in the upper zone of each of said valves, a light 31, 32, in this case, is arranged and extends linearly along the principal dimension of each of them. In addition, the platform 21 providing the support function of said valves extends towards the lower end of the massage head by a side wall 35, from which emanate two axes 33, 34, shown horizontally in the figures, and oriented generally perpendicular to the main dimension of the valves or lights. These axes 33, 34 pass through and cooperate with the lights 31, 32, and support the valves within the body 2, 11 .

Two springs, respectively 36 and 37, one of the points of application is constituted by the axes 33 and 34, and exerting their thrust towards the cam 10 due to the positioning of their other point of application on the axis 25, 26 extending each of the two valves, induce the positioning of the valves in the high position, that is to say, tend to systematically push said valves against the cam path.

Obviously, in this configuration, said valves are no longer linked to the platform 21 by a hinge, of the type described (in references 23 and 24 ) in the previous embodiment, to precisely allow a vertical movement of said valves.

We have shown on Figures 9a to 9d , and on Figures 10a to 10d the positioning of the cam 10, respectively for 0 °, 30 °, 60 ° and 90 °. It is thus possible to observe the altitude variation Δ1 of the valves as a function of the rotation of the cam.

In doing so, it promotes the formation of the skin fold, allowing definitively to overcome any source of aspiration. In addition, it is possible to achieve a "lifting" effect on the treated skin, since simultaneously with the pinching of the skin between the valves, therefore when they are in the closed position ( figure 8b ), a traction of amplitude Δ1 is induced on the fold of skin thus pinched.

In this way, the elasticity, the tone and the firmness of the skin are worked on.

We have shown in relation with the figures 11 and 12 another variant of the massage head of the invention.

According to this variant, the active zone of the massage head firstly comprises a single structural entity, attached to the rest of said head. This structural entity is constituted by the platform 21 provided with the caudron 50 , and from which emanate two bases 38, 39 , rigid, and articulated on two opposite edges of said platform by hinges 23, 24 .

The bases 38 , 39 are each extended by an axis 25 and 26 , perpendicular to the axis of articulation of said bases on the platform 21 , and whose free end is provided with a ball 27 or 28 respectively, intended to cooperate with the cam path 30 formed in the cam 10 .

The active part of the valves, intended to come into contact with the skin, consists of an independent zone 42, 43 coming into contact with the respective bases 38, 39, said zones being provided for this purpose with a housing of form complementary 44, 45, until the upper edge 46, 47 of said zones comes to bear on a shoulder 48 , 49 formed on said bases.

The effective fastening of these zones 42, 43 on the respective bases 38, 39 is for example ensured by the cooperation of the lower end of the axes 25, 26, provided for this purpose with radial protuberances 40, 41 with a dedicated housing 50 , 51 extending the dwellings 44, 45.

The assembly constituted by the platform 21 , the caudron 50 and the bases 38, 39 is advantageously made of plastic and is monobloc. In this case, said bases are pierced with a through hole, to allow the introduction of the pins 25 , 26 , the latter being further provided with a radial projection 51, 52 bearing on the upper edge of the bases , and thus limit their deflection and ensure their function of transmission of movement to the valves.

As can be seen in the Figures 12a and 12b zones 42, 43 may take different configurations, at the option of the operator. In addition, they can be made of different materials, and especially of flexible material, and / or abrasive, or even to excite scented odors or generate an icicle effect, such as for example polypropylene, polyethylene or polyurethane.

As recalled above, it is possible to associate this massage head with a source of vacuum or depression, especially in the case where the valves do not have the additional degree of freedom, described in connection with the Figures 8 to 10 . In this configuration, the air passes through the body 2, 11 around the electric motor 4. It is thus possible to accentuate the formation of the skin fold within the internal chamber between said valves and thus work more deeply the cutaneous tissue. In addition, it is possible with this suction, which can be regulated, to perform a continuous treatment or not the massage on the cut skin.

By the implementation of a solenoid valve, which as recalled in the preamble, provides an operation in all or nothing, but which also allows to define a controlled flow rate of the air flow between two determined values, with the possibility of adjustment between said values, one can play on the synchronism or on the contrary the randomness between the frequency of beats of the valves (mechanically) and the frequency of the phases of aspiration, thus making it possible to favor the blood and lymphatic circulation, or to obtain a "stretching" effect.

Because of this combination of means, it leads to an action of massaging pinch more effective especially for the firming of the skin.

Claims (15)

1. Massage head fitted with a case (2, 11) defining an internal chamber in which a skinfold is formed when it is applied to the skin of a patient, said fold pressing against the lower edges of the chamber, the latter being defined by two lateral walls (28) and by two transverse walls (15, 16), said transverse walls each comprising a clack valve able to be driven in a swivelling motion, so as to cause the lower edges (17, 18) of said clack valves in contact with the skinfold to come closer together and move further apart, characterized in that the relative displacement of the clack valves is ensured by means of a motorized rotary cam (10) provided within the massage head, said cam defining a cam path (30) engaging with a component associated with said clack valves, capable of causing the swivelling motion thereof.
2. Massage head as claimed in claim 1, characterized in that the component associated with the clack valves (15, 16) comprises a ball joint (27, 28), added by means of an axis (25, 26) integral with the end of the clack valves, opposite the free lower edge (17, 18) thereof in contact with the patient's skin.
3. Massage head as claimed in one of claims 1 and 2, characterized in that the cam (10) comprises only one cam path (30) for the two clack valves, said cam path (30) comprising at least one eccentric, and displaying symmetry relative to at least one axis passing through the plane of which it is part and through the centre of rotation of said cam.
4. Massage head as claimed in claim 3, characterized in that the cam path (30) is ellipsoidal.
5. Massage head as claimed in one of claims 1 to 4, characterized in that the end of the clack valves (15, 16) opposite the free lower edge (17, 18) thereof is articulated (23, 24) on a clack valve carrier (21) so that they can swivel and in particular so that the free lower edges can move closer to one another or move further apart.
6. Massage head as claimed in claim 5, characterized in that the clack valve carrier and the clack valves themselves comprise a part made out of a plastic material cast in one piece, and in that the articulation comprises a resilient hinge.
7. Massage head as claimed in one of claims 5 and 6, characterized in that the active area of the massage head comprises:

   • a clack valve carrier (21), secured to said head, and comprising two rigid sub-plates (38, 39) articulated on said support, said sub-plates extending in the direction opposite to the free edge (17, 18) of the clack valves by a component 25 - 28) capable of engaging with the rotary cam (30);

   • and an active part or active area (42, 43), which is fixed onto the other end of the sub-plates, and intended to come into contact with the skin.
8. Massage head as claimed in claim 7, characterized in that the assembly comprising the carrier (21) and the sub-plates (38, 39) is cast in one piece.
9. Massage head as claimed in one of claims 7 and 8, characterized in that the active areas (42, 43) adopt different configurations, chosen by the operator.
10. Massage head as claimed in one of claims 7 to 9, characterized in that the active areas (42, 43) are made out of a material that is flexible and/or abrasive, or even able to support scented odours or generate an ice-cube effect.
11. Massage head as claimed in one of claims 1 to 4, characterized in that the clack valves (15, 16) are each fitted with an aperture (31, 32) orientated in accordance with the principal dimension thereof and extending in the upper area thereof, in other words opposite free lower edges, said apertures each engaging with an axis (33, 34) perpendicular thereto coming from a clack valve support (35) within the massage head, said clack valves each being subject to the action of a resilient return component (36, 37) causing the permanent thrust of the ball joints (27, 28) associated with the clack valves against the cam path (30).
12. Massage device employing a massage head as claimed in one of claims 1 to 11, and comprising an electrical power source suitable for actuating the electric motor (4) included in the massage head and rotating the cam.
13. Massage device as claimed in claim 12, characterized in that it also includes a vacuum or negative pressure source, communicating with the massage head, and intended to generate within the internal chamber thereof a negative pressure capable of generating suction on the patient's skin, and forming a skinfold within said internal chamber.
14. Massage device as claimed in claim 13, characterized in that the vacuum or negative pressure source is controlled by means of a solenoid valve.
15. Massage device as claimed in claim 14, characterized in that the frequency of the suction phases generated by the vacuum or negative pressure source and the frequency of clack valve flutter is or is not synchronous.

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