Child's pacifier

Abstract

Title: Pacifier for children. The invention relates to a pacifier for children, comprising a teat (30) intended to be placed in the child's mouth and a base (50) to which the teat (30) is attached and comprising a first face (51) intended to be applied to an external area of ​​the child around the mouth, characterized in that at least one of the base (50) and the teat (30) comprises an acoustically absorbing element (10) having at least one cavity (5) opening through at least one hole (2). Figure for the abstract: Fig. 1

Description

Title of the invention: Child's pacifier technical field

[0001] The present invention relates to a pacifier for children, and in particular for infants. STATE OF THE ART

[0002] Typically, a pacifier consists of a protrusion designed to be placed in the child's mouth. It is well known that infants and toddlers can be comforted by a pacifier. Generally, all pacifiers have a nipple-like protrusion that is placed in the child's mouth and attached to a shield that remains outside the child's mouth, preventing the child from swallowing or choking on the pacifier. A handle is usually provided to give the child or a caregiver a method for holding the pacifier. They are generally made up of several components with different materials. Typically, the pacifier's nipple is made of a soft, flexible material, while the shield and handle are usually made of a more rigid material.

[0003] Even if a classic pacifier helps to calm the child and limit his propensity to scream or cry, the pacifier only has a mechanical action of sucking reflex.

[0004] This means that when the child cries or screams despite his pacifier, the nuisance caused to those around him remains entirely.

[0005] For example, comfort in means of transport such as airplanes or trains depends on the ambient noise level produced by the vehicles or by passengers and staff. While the noise sources of the means of transport are likely to meet noise standards, the noise produced by passengers is not addressed.

[0006] There is a need to propose a solution to this problem. We propose to reduce the noise level caused by children when they shout or cry, even when they are using a pacifier. SUMMARY

[0007] To achieve this objective, according to one embodiment, a child's pacifier is provided, comprising a teat intended to be placed in the child's mouth and a base to which the teat is attached and comprising a first face intended to be applied to an external area of ​​the child around the mouth, characterized in that at least one of the base and the teat comprises an acoustically absorbing element having at least one cavity opening through at least one hole.

[0008] With this design, the pacifier incorporates a sound-reducing function. At least some of the acoustic waves emitted by the child are captured in the cavity, which then acts as a resonator. The sounds are thus reduced. Nothing suggests to a person skilled in the art that they should incorporate a sound-absorbing element into a pacifier. The bulkiness they might anticipate from such an element would undoubtedly also be a deterrent.

[0009] One interest, therefore, is to functionalize a pacifier for infants capable of reducing the noise level of crying, without causing discomfort to the child or diminishing the vigilance of the parents (or other person in charge of the child). BRIEF DESCRIPTION OF THE FIGURES

[0010] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which:

[0011] [Fig.1] Fig.1 represents a general perspective view of a lollipop according to the invention.

[0012] [Fig.2A] Fig.2A represents a front view.

[0013] [Fig.2B] Fig.2B represents a cross-sectional view along line BB of the [Fig.2A].

[0014] [Fig.3A] Fig.3A represents an example of an acoustically absorbing element, in front perspective.

[0015] [Fig.3B] Fig.3B represents an example of an acoustically absorbing element, in rear perspective.

[0016] [Fig.3C] Fig.3C represents an example of an acoustically absorbing element, in front view.

[0017] [Fig.3D] The [Fig.3D] represents an example of an acoustically absorbing element, in rear view.

[0018] [Fig.4A]

[0019] [Fig.4B]

[0020] [Fig.4C]

[0021] [Fig.4D]

[0022] [Fig.4E]

[0023] [Fig.4F]

[0024] [Fig.4G] Figures 4A to 4G show examples of hole cross-section shapes for the acoustically absorbing element.

[0025] [Fig.5A]

[0026] [Fig.5B]

[0027] [Fig.5C]

[0028] [Fig.5D] Figures 5A to 5D show acoustic absorption diagrams, as a function of acoustic wave frequency and hole shapes.

[0029] [Fig.6A]

[0030] [Fig.6B] Figures 6A to 6B show perspective views, in two opposite directions, of part of an acoustically absorbing element with different shapes of holes and tubes.

[0031] [Fig.7A]

[0032] [Fig.7B] Figures 7A to 7B show cross-sectional views of example longitudinal tube configurations.

[0033] [Fig.8] Fig.8 is a simulated acoustic attenuation diagram (in dB), in function of the acoustic wave frequency, provided by an acoustically absorbing element with a surface area of ​​30 x 30 mm2 as integrated into a teat shown in figures 1 and 2A, 2B.

[0034] [Fig.9] Figure [Fig.9] shows an example of a filtered temporal signal of baby cries digitally between 2000 and 9000 Hz using a lollipop of the invention conforming to figures 1 and 2A, 2B. It is noted that there is a sufficiently tangible reduction of the temporal content in the filtered part corresponding to the hatched median area.

[0035] [Fig.1OA] Fig.1OA shows an example of an absorption diagram, as a function of frequency, for a single-layer type metamaterial, with a total thickness of 7 mm, with, for the frequency band "2000-8000 Hz", nine resonator cavities with square section tubes such as 1.3 < L=d <1.9 ([Fig.4B]), tube lengths between 1 and 5 mm, cavity thickness of 5 mm, on a total surface of 15 x 15 mm2 (potentially repeatable 3 to 4 times along the surface).

[0036] [Fig.1OB]

[0037] [Fig.1OC] Figures 10B and 10C show examples of absorption diagrams, as a function of frequency.

[0038] [Fig. 11 A] The [Fig. 11 A] give examples of shape and dimensions for the holes, for a cross-section of approximately 1.27 mm2.

[0039] [Fig. 1 IB] The [Fig. 1 IB] gives examples of shape and dimension for the holes, for a cross-section of the order of 3.14 mm2.

[0040] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of principle intended to facilitate understanding of the invention. DETAILED DESCRIPTION

[0041] Before proceeding to a detailed review of embodiments of the invention, optional features that may be used in combination or alternatively are listed below:

[0042] According to one option, the base 50 includes at least one acoustically absorbing element 10, at least one cavity 5 of said element opening 10 through at least one hole 2 on the first face 51.

[0043] In this way, the surface of the base 50 facing the child's mouth is used to house the sound absorber.

[0044] Preferably, the base 50 comprises a shield 40 extending transversely to a longitudinal dimension of the teat 3, the acoustically absorbing element 10 being disposed between the teat 30 and the shield 40.

[0045] Thus, sound absorption occurs as close as possible to the teat. This offers a wide range of design options, including an absorber integrated with the shield, or separate and assembled with the latter.

[0046] In one embodiment, the acoustically absorbing element 10 comprises a surface wall 1 which forms an area of ​​the first face 51 of the base 50 which surrounds, preferably completely, the teat 30.

[0047] Thus, the sound reduction is distributed all around the teat. The element 10 can also be constructed with angular sectors, for example less than or equal to 90°, around the teat 30. The sectors can be identical, thus forming a repeating pattern around the teat. This provides sound absorption whose absorption parameters are distributed around the teat 30.

[0048] Advantageously, the teat 30 comprises a distal portion 35 intended to be placed in the mouth and a proximal portion 32 passing at least partially through the acoustically absorbing element 10.

[0049] Thus, the attachment of the pacifier is practical, for example by gluing and / or by obstacle, for example in the case where the proximal part completely passes through the acoustically absorbing element and applies itself against its rear face or at the end of the cavity.

[0050] According to one option, the teat 30 comprises at least one acoustically absorbing element 10, at least one cavity 5 of said element 10 opening through at least one hole to a distal surface 34 of the teat 30 intended to be placed in the mouth.

[0051] Preferably, the at least one acoustically absorbing element 10 comprises, for at least one hole 2, a tube 3 extending into the cavity 5 between a proximal end forming the mouth of the hole and a distal end open into the cavity 5.

[0052] This allows resonators to be formed.

[0053] Advantageously, at least one tube 3 comprises a wall formed in part by the partition 4 defining the cavity 5 in which said tube 3 extends.

[0054] In this way, the walls forming the cavity partition and the tube wall are combined, which limits the mass of the acoustically absorbing element. Furthermore, this retains a larger cavity volume, which increases the efficiency of the absorbing element.

[0055] According to one possibility, at least one acoustically absorbing element 10 comprises on a base surface SB:

[0056] - a surface wall 1 which is provided with multiple holes 2, each hole forming individually a free passage through said surface wall;

[0057] - a spacer structure, which is connected to an internal face FI of the wall surface I and adapted to fix a gap E between said surface wall and the base surface SB, so as to form at least one acoustic cavity between the inner face of the surface wall and the base surface; and

[0058] - tubes 3, which are connected to the surface wall 1 and extend into the cavity acoustics from the inner face FI of said surface wall towards the base surface SB, each tube being open at two opposite ends of said tube, and being dedicated to one of the holes 2 of the surface wall with a cross-section of the hole which is contained within an internal cross-section of the tube at the level of the surface wall, wherein a length of each tube 3 is less than the distance E between the surface wall 1 and the base surface SB, said tube length being measured in a direction perpendicular to the inner face FI of said surface wall

[0059] According to one embodiment, at least 10% of the gap E between the surface wall 1 and the base surface, against said base surface SB, is free of tubes 3.

[0060] Possibly, several of the holes 2 in the surface wall 1 have different shapes and / or hole 2 cross-sectional areas, and such that a ratio of hole cross-sectional perimeter to hole 2 cross-sectional area varies between at least some of said holes 2.

[0061] According to one example, at least some of the tubes 3 have different respective lengths, each measured along the direction perpendicular to the inner face FI of the surface wall 1.

[0062] Possibly, each tube 3 extends perpendicularly to the inner face FI of the surface wall 1.

[0063] Advantageously, the length of each tube 3 is less than the gap E between the surface wall 1 and the base surface SB, by a distance which is between 2 mm and 40 mm, along the direction perpendicular to the inner face FI of said surface wall.

[0064] The height of at least one of the tubes 3 can be equal to a value between that of the thickness of the surface wall and a maximum value such that it leaves at least 1 mm of spacing (which corresponds to the distance dr) between the bottom of the tube 3 and the base surface SB.

[0065] According to one option, but without this being absolutely necessary, for at least one of the tubes 3, the internal section of said tube varies as a function of a distance measured from the internal face FI of the surface wall 1 along the direction which is perpendicular to said internal face of the surface wall 1.

[0066] According to one example, a peripheral edge of at least one of the holes 2 is a polygon with more than four sides.

[0067] In one case, the peripheral edge of at least one of the holes 2 has a fractal pattern of order greater than or equal to 2.

[0068] An advantageous aspect includes connecting a perforated wall to curved tubes, flexible or rigid, opening into cavities, so as to drastically reduce absorption frequencies by increasing the propagation length of acoustic waves within the tubes and by strong coupling with the cavities. The frequency band achieved by combining different resonators in parallel (metamaterial) is generally between 250 and 10,000 Hz and reaches several thousand Hz.

[0069] Another aspect concerns the manufacture of all or part of the device, and in particular at least the absorbing element, by additive manufacturing. The tubes of such an element, and optionally also the peripheral structure of the tubes, can be formed by a three-dimensional printing or injection molding process from the inner face of the surface wall.

[0070] In the following description, the term "on" does not necessarily mean "directly on." Thus, when it is stated that a part or component A is supported "on" a part or component B, this does not mean that parts or components A and B are necessarily in direct contact with each other. These parts or components A and B may be either in direct contact or supported by each other via one or more other parts. The same applies to other expressions such as, for example, the expression "A acts on B," which may mean "A acts directly on B" or "A acts on B via one or more other parts."

[0071] In this patent application, the terms "fixed" and "driven" used to describe the connection between two parts mean that the two parts are fixed / attached to each other with respect to all degrees of freedom, unless explicitly specified otherwise. For example, if it is stated that two parts are fixed in translation along a direction X, this means that the parts can be movable relative to each other except along the direction X. In other words, if one part is moved along the direction X, the other part moves in the same direction.

[0072] Figure 1 illustrates a perspective view of an example embodiment of the pacifier according to the invention. The teat 30 corresponds to the portion that protrudes beyond the first phase 51 of a base 50 and which is placed in the mouth by the child. Figures 2A and 2B show other representative views of this embodiment of the pacifier 30. For example, it may include a portion with a substantially circular cylindrical cross-section forming a trunk extending from the first face 51. According to one possibility, it has a proximal end 32 which cooperates with other parts of the pacifier, particularly for the purpose of securing the nipple 30.

[0073] In the case shown, the other end, distal end 31, of the teat 30 corresponds to its tip. A contoured portion can be formed between the body of the teat and the distal end 31. The illustrations show a portion forming a concave curvilinear front surface 34, for example, suitable for cooperating with the child's tongue, and, on the other side of the distal end 31, a convex curvilinear surface forming a bulge.

[0074] Preferably, the distal portion 35 of the teat 30, and in particular thanks to this profiled part, is wider than the trunk of the teat 30.

[0075] Depending on one possibility, the teat 30 is made of a soft material such as silicone or an elastomer material, or any other material compatible with pediatric application. It preferably has a lower hardness than the base 50 described below.

[0076] Fig. 1 shows an example of the base 50. This forms the main body of the pacifier and serves as a support for the teat 30.

[0077] Figures 1 and 2A, 2B show a base extending transversely wider than the teat 30 so as to constitute a surface, corresponding to the first phase 51, suitable for applying around the child's mouth to retain this part of the pacifier outside the mouth, unlike the distal portion of the teat 30.

[0078] The external contour of the base 50 may conform to that found on currently commercially available pacifiers. Typically, this contour may have softened, concave, and convex curvilinear shapes as shown.

[0079] Advantageously, the base 50 is made from one or more pieces of plastic material. The plastic material(s) used for this purpose are preferably harder than the material of the distal portion 35 of the teat 30.

[0080] The pacifier also includes, advantageously but not exclusively, a handle 20 connected to the base 50 by a portion of the latter opposite the protruding part of the teat 30. Preferably, the handle 20 is rotatably mounted on the base 50; it constitutes a hand-gripping element for the teat. It may be made of a hard plastic material.

[0081] According to the invention, the pacifier comprises at least one acoustically absorbing element 10.

[0082] In the case of the examples shown in Figures 1 to 3D, an acoustically absorbing element 10 is carried by the base 50. Alternatively or in addition, at least one acoustically absorbing element 10 can be formed on the nipple 30. This case is not shown, but it is easily understood that the nipple 30, in particular at the level of the front surface 34, can include the elements described below, in particular with regard to the formation of cavities and holes, which preferably open in this case at the level of the front surface 34.

[0083] To return to the embodiment corresponding to the illustrations, the base 50 includes an element 10 (there could be several) which surrounds the base of the teat 30, at the level of its proximal end 32.

[0084] Thus, in this example, the teat 30 is surrounded by the element 10 which forms part of the base 50, another part of the base 50 being formed by a shield 40 which constitutes the most transverse part of the base 50 and which extends transversely beyond the element 10.

[0085] In one embodiment, such as that shown in [Fig. 2B], the teat 30 is mounted on the base 50 through the acoustically absorbing element 10. More specifically, the element 10 has a passage 11, preferably in its center, to receive the proximal end 32 of the teat 30, so as to form a joint between these two parts. Assembly by bonding and / or mechanical fastening means are possible. For example, the case of a teat 30 whose distal end 32 includes a rim 33 designed to be applied to the rear face of the base 50, which then forms an obstacle to the removal of the teat 30, is shown. Also in this example, the cover 60 provides a clamping grip on the rim 33 in addition to the rear face of the base 50.

[0086] Advantageously, the cover 60 is removable to facilitate cleaning of the pacifier, in particular with regard to the element 10 and the teat 30.

[0087] Referring for example to [Fig.2B], it is noted that the acoustically absorbing element 10 has an external face FE which participates in the first face 51 of the base 50. The external face FE includes one or more holes 2 which allow at least one cavity 5 to open at the level of the face FE.

[0088] In the case shown, each cavity 5 is defined laterally by partitions 4 extending preferably not parallel to the external face FE, corresponding to the y direction of figures 1 and 2A, 2B. According to one possibility, the partitions 4 are parallel to the direction perpendicular to the face FE, that is to say the z direction of the figures.

[0089] As schematically shown in [Fig.2B], acoustic waves OA impact the external face FE and are partly trapped by the cavity or cavities 5, which allows sound absorption.

[0090] The illustration also shows that the cavities 5 are also defined by a bottom 5b.

[0091] In the illustrated case, the bottom 5b corresponds to the inner face of a bottom wall 100. The latter is itself made in a cover 60 producing a closing element for the rear face of the acoustically absorbing element 10. In the case shown, the cover 60 is also a closing element for the rear face of the teat 30.

[0092] In an embodiment not shown, the element 10 may comprise several tiers of cavities 5 arranged successively along the longitudinal direction of the nipple, i.e., the z-direction. In this case, the bottom surface 5b is itself a surface comprising holes like the face FE, these holes opening into additional cavities defined laterally by partitions and a bottom; it is understood that a cavity of one tier can thus open into a cavity of a subsequent tier; if it is the last cavity tier, this bottom is then advantageously free of holes. If there is an additional tier, this bottom comprises holes opening into new cavities. For example, two tiers of cavities can be formed, and it is understood that sound absorption is increased by increasing the number of tiers.

[0093] Preferably, the acoustically absorbing element 10 comprises, for at least one hole 2, a tube 3 extending into the cavity 5. Thus, the opening of the hole 2 continues inside the cavity 5 via a tube 3. In some cases, there is no portion of tube below the hole 2, which corresponds to a situation in which the tube 3 ultimately has the same thickness as the hole 2. In other cases, the tube 3 extends deeper inside the corresponding cavity 5 along a length dimension 1 of the tube 3, which is discussed in more detail later in the description. It is advantageous to have tubes of different lengths 1 and / or cavities of different volumes V and / or holes 2 of different shapes and cross-sections, so as to provide sound absorption over a wide range of acoustic frequencies.

[0094] Figures 3A to 3D provide views of the acoustic element 10 from its front face and from its rear face.

[0095] According to one option shown in these figures, the holes 2 have variable dimensions. For example, but not limited to, the cross-sectional area of ​​the holes 2 may decrease as one moves away from the nipple 30. According to another option, the wall of the tubes 3 may be partly formed by a portion of the partitions 4.

[0096] It should also be noted from these illustrations that the element 10 can be organized into angular sectors, preferably of identical angular amplitude, reproducing the same pattern of hole and cavity formation, and advantageously of tubes. The angular sectors can, for example, be of 90° or of an amplitude lesser. For example, twelve identical angular sectors can be formed, distributed around the nipple 30.

[0097] The following are only indicative aspects of the structures, shapes and dimensions of the absorbing element 10:

[0098] According to one aspect, several of the holes in the surface wall have different hole cross-section shapes, and such that a ratio of hole cross-section perimeter to hole cross-section area varies between at least some of the holes.

[0099] Indeed, for a given hole cross-sectional area, a hole through the surface wall causes acoustic resistance, which is greater when its cross-sectional perimeter is longer. More precisely, a principal absorption peak is higher or lower depending on the ratio of the hole cross-sectional perimeter to the hole cross-sectional area. Using holes with different values ​​for this ratio makes it possible to maximize the absorption peak.

[0100] In preferred embodiments of the invention, at least one of the following additional features may advantageously be applied, alone or in combination with several of them: • a section of each hole can be identical to the internal section of the tube associated with it, at the level of the inner face of the surface wall; • at least some of the tubes may have different respective lengths, each measured along the direction perpendicular to the inner face of the surface wall; • each tube can extend perpendicularly to the inner face of the surface wall; • the length of each tube may be less than the distance between the surface wall and the base surface, by a distance which is between 2 mm and 40 mm, in the direction perpendicular to the inner face of the surface wall; • For at least one of the tubes, the internal cross-section of that tube can vary as a function of a distance measured from the inner face of the surface wall, along the direction perpendicular to that inner face. In particular, it can vary homothetically about a central axis of the tube, with a homothety ratio that varies as a function of the distance from the surface wall. Specifically, a distance between the central axis of the tube and an internal surface of the same tube, in a meridian plane of the tube, can vary exponentially as a function of the distance from the inner face of the surface wall; • a peripheral edge of at least one of the holes may be a polygon with more than four sides. In particular, this peripheral edge of the hole may possess a fractal pattern of order greater than or equal to 2; • the set of holes can occupy a surface fraction which is between 2% and 20%, preferably between 4% and 8%, of the inner face of the surface wall; • The spacer structure may include rigid partitions extending perpendicularly to the inner face of the surface wall. In this case, the distance between two opposite partitions of the spacer structure is preferably less than half of the smallest acoustic wavelength prescribed for the element; • for each hole, a smallest distance between two parallel and opposite edge parts of the hole is preferably greater than twice the thickness of the acoustic boundary layer, the latter being equal to (pnf / q) 1 / 2, where p is the density of air at 25°C (degrees Celsius) and 105 Pa (Pascals), q is the viscosity of air under the same conditions, and f is a prescribed acoustic frequency for the element, between 100 Hz and 500 Hz, for example equal to 200 Hz.

[0101] Generally, one end of the spacer structure that is opposite the surface wall can be adapted to be glued to the base surface.

[0102] The element 10 is fixed to the surface SB of the bottom wall 100, for example by gluing the distal ends 4a of the partitions 4 to the base surface SB.

[0103] Element 10 comprises the surface wall 1, the tubes 3 and the partitions 4. The rigid tubes 3 and partitions 4 can be attached to the inner face FI of the surface wall 1, or be continuous with the surface wall 1, for example, by being formed from the inner face FL. They may extend perpendicularly to the inner face FI of the surface wall 1, but not necessarily. According to a preferred manufacturing method for the bottom wall 100, at least the tubes 3, but possibly also the partitions 4, can be produced by 3D printing or using an injection molding process. The length of the partitions 4 determines the spacing E ([Fig. 2B]) when the element 10 is fixed to the surface SB of the bottom wall 100. Preferably, the partitions 4 have identical lengths so that the inner face FI and the base surface SB are parallel.Without the tubes 3, the spacing E would be approximately equal to one-quarter of a wavelength value for the acoustic background OA, for which maximum sound absorption is desired. However, with the tubes 3, the spacing E can be, for example, 1 / 20 to 1 / 30 of the acoustic wavelength for which maximum sound absorption is desired. The absorption frequency. The maximum acoustic wave OA can therefore be reduced by a factor of 5 to 7, thanks to the presence of tubes 3, compared to a resonator without tubes 3, for a given spacing E. Furthermore, the distance between two opposing partitions 4 is preferably less than half the shorter acoustic wavelength prescribed for element 10. Under these conditions, the acoustic wave OA passes through the surface wall 1 primarily through the holes 2, propagates along the tubes 3, then into volume V towards the bottom wall 100, is reflected by the base surface SB, propagates again into volume V but towards the surface wall 1, and then passes again through the tubes 3 and the surface wall 1 outwards. As is known, the absorption of the acoustic wave OA occurs essentially at each passage through the tubes 3 and the surface wall 1.

[0104] The geometry of each partition 4 can be arbitrary. In particular, each partition 4 can have one or more openings while ensuring the function of a rigid spacer between the surface wall 1 and the bottom wall 100.

[0105] Each hole 2 extends from the outer face FE of the surface wall 1 to its inner face FI, so as to form a free passage between the exterior and the intermediate volume V. This allows a portion of the acoustic base OA to pass through the surface wall 1. The acoustic absorption spectrum affecting the base OA during such a passage is shifted towards lower frequency values ​​when the ratio of the perimeter of the hole 2 to its cross-sectional area is higher. Tables 1 and 2, shown respectively in Figures 11A and 11B, indicate the values ​​of the ratio of the hole perimeter to its cross-sectional area for different shapes and for two values ​​of hole cross-sectional area:

[0106] The indications in Table 1 are for a cross-sectional area of ​​each hole 2 of the order of 1.27 mm2.

[0107] The indications in Table 2 are for a cross-sectional area of ​​each hole 2 of the order of 3.14 mm2.

[0108] Generally, the smallest distance between two parallel and opposite parts of the edge of a hole is preferably greater than twice a thickness Δac of acoustic boundary layer, calculated according to the formula: Δac = (pHf / q) - 11, where p is the density of air at 25°C and 10⁵ Pa, q is the viscosity of air under the same conditions, and f is the acoustic background frequency OA, preferably between 100 Hz and 500 Hz, for example, 200 Hz. This condition ensures that a significant portion of the acoustic background OA penetrates the intermediate volume V through the hole 2. Each hole 2 is provided with a tube 3 extending from the inner face FI of the surface wall 1 towards the bottom wall 100. In the described embodiments, but without this being Essential to the invention, each tube 3 has a central longitudinal axis AA that is straight and perpendicular to the inner face FI at the location of the hole. Furthermore, the internal cross-section of each tube 3 at the level of the inner face FI is identical and coincides with the cross-section of the corresponding hole 2. Moreover, each tube 3 has a length I that is less than 90% of the distance E between the inner face FI of the surface wall 1 and the base surface SB of the bottom wall 100. Under these conditions, the diagrams in Figures 3A, 3B, 3C, and 3D each show the effect of the shape of the holes 2 on the acoustic background absorption spectrum OA. The horizontal axis of each diagram represents the acoustic background frequency f OA, expressed in hertz (Hz), and the vertical axis represents the spectral absorption, denoted Abs(f), normalized with respect to its maximum value of 1.

[0109] The diagram in [Fig. 5A] corresponds to a value of 10 mm (millimeter) for the distance E between the inner face FI of the surface wall 1 and the base surface SB of the bottom wall 100. The diagram in [Fig. 5B] corresponds to a value of 20 mm for this distance E. All the tubes 3 have a length I equal to 5 mm (millimeter) and an internal cross-sectional area of ​​approximately 1.27 mm² for both diagrams in Figures 5A and 5B. For each curve in these diagrams, all the holes 2 are identical, of the shape indicated in the legend inset of the corresponding diagram, and with the hole dimensions indicated in Table 1 above for that hole shape.Comparison between these two diagrams shows that the main low-frequency absorption peak shifts towards lower values ​​of the frequency f as the spacing E increases, and that, for a constant spacing E, this peak also shifts towards lower values ​​of the frequency f as the ratio of hole perimeter to hole cross-sectional area increases. Furthermore, [Fig. 5B] shows a broadening of approximately 7% in the lower main absorption frequency band as the perimeter-to-hole cross-sectional area ratio increases.

[0110] To shift the absorption peak around, or below, 500 Hz, the length I of the tubes 3 can be fixed at 15 mm for a spacing E between the inner face FI of the surface wall 1 and the base surface SB of the bottom wall 100 of 20 mm ([Fig. 5C]) or 30 mm ([Fig. 5D]). All the holes 2 relating to each of the curves in Figures 5C or 5D still have the same shape, which is indicated in the legend inset of the corresponding diagram, with a hole cross-sectional area of ​​approximately 3.14 mm² (see Table 2 of [Fig. 1 IB] for the dimensions of the holes that correspond to the curves in Figures 5C and 5D). We then observe the same behaviors as when the length I of the tubes 3 is equal to 5 mm and the cross-sectional area of ​​the hole is on the order of 1.27 mm² (Figures 5A and 5B), that is to say a Maximum absorption is governed by the ratio of the hole perimeter to the hole cross-sectional area. An element 10 according to the invention is illustrated in Figures 6A and 6B. For clarity, partitions 4 are not shown in Figures 6A and 6B, but are present in the actual element. In this element 10, the shape of the holes 2 varies among several of them, so as to vary, within the same element, the value of the ratio of the hole perimeter to its cross-sectional area. Thus, the same element 10 simultaneously has holes 2 of at least two different patterns, including a round pattern, a cross pattern, a slot, a hexagon, a six-pointed star, fractals of various patterns, etc., and whose orientations in the external face FE can also vary. The absorption spectrum of such an element 10 is therefore a combination of the spectra corresponding to each of the hole cross-sectional shapes.Consequently, the resulting absorption spectrum exhibits a broadened main absorption peak at low acoustic frequencies, with a constant value for the spacing E. This broadened peak produces, in particular, higher acoustic absorption values ​​when the acoustic frequency f is below 500 Hz. The absorption efficiency gain obtained in this way, at 500 Hz, can be 7% or more.

[0111] The tube 3 associated with each hole 2 can have an internal cross-sectional shape that is identical to the cross-section of the corresponding hole 2. In the embodiment of the invention illustrated in Figures 6A and 6B, the internal cross-sectional area of ​​each tube 3 is invariant along each tube, and all the tubes 3 have the same length.

[0112] Figure 7A illustrates early embodiments of the invention, in which some of the tubes 3 of the element 10 in Figures 6A and 6B may have lengths I that vary from one tube to another. The residual free distance, denoted dr, which exists between the distal end of one of the tubes 3, opposite the surface wall 1, and the bottom wall 100, is equal to E - 1. For elements conforming to the invention, this residual free distance dr is greater than 10% of the spacing E. This condition is maintained when all the tubes 3 have identical lengths. In general, it ensures an optimal combination between the resonance effect produced by the spacing E and the increased sound absorption produced by the varied shapes of the holes 2. Preferably, the residual free distance dr can be greater than 2 mm for all the tubes 3 of the element 10. Figure 7A illustrates the first embodiments of the invention, in which some of the tubes 3 of the element 10 may have lengths I that vary from one tube to another. The residual free distance dr is equal to the length of the tubes 3 of the element 10.Figure 7B illustrates second variants of the invention, in which some of the tubes 3 of the element 10 may have internal sections that vary according to the distance x from the inner face FI of the surface wall 1. For example, the internal section of a tube 3 may vary between two planes that are perpendicular to the axis AA of this tube and that correspond to different values ​​for the distance x, in a homothetic manner with a homothety ratio that depends on the distance x. For x=0, the internal section of the tube may . be identical to that of the corresponding hole 2. Therefore, the distance r between the internal surface of a tube 3 and the central axis AA of that tube can vary according to the distance x in a way that is identical in all meridian planes containing the axis AA. r(x) is thus the homothety ratio introduced above. In different embodiments of the invention, r(x) can be a segment of an affine function, increasing or decreasing, or a segment of an exponential function, which can again be increasing or decreasing, or a segment of a parabola, a segment of a hyperbola, etc. Possibly, r(x) can be a linear combination of several of these functions and, in general, r(x) can be any function as long as the distal end of the tube 3 is open.Thus, each tube 3, whose cross-section varies along its central axis AA, can constitute a conical, exponential, parabolic, hyperbolic, etc., horn, which couples the intermediate space V to the free passage formed by the corresponding hole 2 through the surface wall 1. As is known, such a horn, which flares outward from the inner face FI of the surface wall 1, promotes the transfer of acoustic energy through the hole 2. Furthermore, such a horn exhibits a cutoff frequency Fc, below which the acoustic fundamental frequency OA is no longer transmitted through the horn (corresponding to f < Fc). This cutoff frequency is Fc = C / (4n-a), where a is a characteristic length of variation of the function r(x).

[0113] The features of the first and second variants of the invention, illustrated by figures 7A and 7B, can also be combined in improved embodiments.

[0114] The number of holes 2 per unit area of ​​the surface wall 1 can be between one hole / cm2 and eight holes / cm2. Considering the cross-sectional area of ​​each hole, which can be between 1 mm2 and 4 mm2, for example, the set of holes can occupy a surface area fraction of the surface wall 1 of 4% to 8%, by way of example.

[0115] Finally, the partitions 4 can form a set of separate cells which are juxtaposed on the inner face FI of the surface wall 1. A single hole 2, with its associated tube 3, can be contained in each cell, but it is also possible to arrange several holes 2, with the tubes 3 associated with them, inside the same cell.

[0116] It is understood that the numerical values ​​that have been cited are only by way of example.

[0117] Figures 10A to 10C supplement the illustrations of the sound absorption results obtained. In the case of [Fig. 10A], they correspond to a sound absorption element with a 5-cavity stage, with a total thickness of 7 mm, and, for the frequency band "2000-8000 Hz", with nine resonance cavities, each equipped with a tube square such that 1.3 < L=d < 1.9 ([Fig.4B]), tube lengths between 1 and 5 mm, cavity thickness of 5 mm, on a total surface of 15 x 15 mm2 (potentially repeatable three to four times along the FE surface).

[0118] [Fig. 10B] presents an absorption diagram for a two-stage cavity 5 element 10, with a total thickness of 10.5 millimeters, for the frequency band "2000-6000 Hz", with nine resonant cavities 5 each having a "fractal type 1" tube such that 0.5 < d < 0.6 mm ([Fig. 4C]), of lengths between 1.1 and 5 mm, on a total surface of 15 x 15 mm2, (potentially repeatable 3 to 4 times along the surface) with a cavity thickness of 5 mm.

[0119] [Fig. 10B] presents an absorption diagram for a 2-stage 10 element of 5 cavities, with a total thickness of 10.5 millimeters, for the frequency band "6000-9000 Hz", with 9 resonant cavities 5 each having a "fractal type 1" tube such that 0.5 < d < 0.6 mm ([Fig. 4C]), of lengths between 1 and 2 mm, on a total surface of 15 x 15 mm2, (potentially repeatable three to four times along the surface), with a cavity thickness of 2.5 mm.

[0120] It appears that the proposed architectures make it possible to obtain significant absorptions in the useful frequency band while having a thickness compatible with the bases of conventional teats, for example less than 20 mm.

[0121] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

[0122] NUMERICAL REFERENCES

[0123] 1. Surface wall 2. Hole 3. Tube 4. Partition 4a. Distal end of each septum 5. Cavity 5b. Cavity floor 10. Acoustically absorbing element 11. Passage 100. Back wall 20. Handle 30. Pacifier 31. Distal end 32. Proximal end 33. Rim 34. Front surface 35. Distal portion 40. Shield 50. Base 51. First side 60. Hood 61. Interlocking zone SB. Base surface FI. Inner face FE. External face V. Cavity Volume OA. Acoustic wave incident on the surface wall E. Gap between the inner face FI and the base surface SB 1. Tube length d. hole dimension D. hole length r(x). Distance to axis AA Dr. Residual Distance x. Distance from FI

Claims

Demands

1. Child's pacifier, comprising a teat (30) intended to be placed in the mouth by the child and a base (50) to which the teat (30) is attached and comprising a first face (51) intended to be applied to an external area of ​​the child around the mouth, characterized in that at least one of the base (50) and the teat (30) comprises an acoustically absorbing element (10) having at least one cavity (5) opening through at least one hole (2).

2. Lollipop according to the preceding claim, wherein the base (50) comprises at least one acoustically absorbing element (10), at least one cavity (5) of said element opening (10) through at least one hole (2) on the first face (51).

3. Pacifier according to the preceding claim, wherein the base (50) comprises a shield (40) extending transversely to a longitudinal dimension of the teat (30), the acoustically absorbing element (10) being disposed between the teat (30) and the shield (40).

4. Pacifier according to the preceding claim, wherein the acoustically absorbing element (10) comprises a surface wall (1) which forms an area of ​​the first face (51) of the base (50) which surrounds the teat (30).

5. Pacifier according to the preceding claim, wherein the teat (30) comprises a distal portion (35) intended to be placed in the mouth and a proximal portion (32) passing at least partially through the acoustically absorbing element (10).

6. Pacifier according to any one of the preceding claims, wherein the teat (30) comprises at least one acoustically absorbing element (10), at least one cavity (5) of said element (10) opening through at least one hole to a distal surface (34) of the teat (30) intended to be placed in the mouth.

7. Lollipop according to any one of the preceding claims, wherein the at least one acoustically absorbing element (10) comprises, for at least one hole (2), a tube (3) extending into the cavity (5) between a proximal end forming the mouth of the hole and a distal end open into the cavity (5).

8. Lollipop according to the preceding claim, in which at least one tube (3) comprises a wall formed in part by the partition (4) defining the cavity (5) in which said tube (3) extends.

9. Lollipop according to any one of the preceding claims, wherein at least one acoustically absorbing element (10) comprises on a base surface (SB): - a surface wall (1) which is provided with multiple holes (2), each hole individually forming a free passage through said surface wall; - a spacer structure, which is connected to an inner face (FI) of the surface wall (I) and adapted to fix a gap (E) between said surface wall and the base surface (SB), so as to form at least one acoustic cavity between the inner face of the surface wall and the base surface;and - tubes (3), which are connected to the surface wall (1) and extend into the acoustic cavity from the inner face (FI) of said surface wall towards the base surface (SB), each tube being open at two opposite ends of said tube, and being dedicated to one of the holes (2) of the surface wall with a section of the hole which is contained in an internal section of the tube at the level of the surface wall, in which a length of each tube (3) is less than the spacing (E) between the surface wall (1) and the base surface (SB), said tube length being measured in a direction perpendicular to the inner face (FI) of said surface wall;

10. Lollipop according to the preceding claim, wherein several of the holes (2) in the surface wall (1) have shapes and / or hole cross-section surfaces (2) which are different, and such that a ratio of hole cross-section perimeter (2) to hole cross-section area (2) varies between some at least of said holes (2).

11. Lollipop according to any one of the two preceding claims, wherein at least some of the tubes (3) have respective lengths which are different, each measured along the direction perpendicular to the inner face (FI) of the surface wall (1).

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