Surround with grooves, loudspeaker transducer and enclosure comprising the surround

Description

Technical field of the invention

[0001] The present invention relates to a ribbed suspension and a loudspeaker ("HP") incorporating it. The first area of ​​the invention is therefore the external, or "front," suspension of a loudspeaker or electrodynamic transducer. It applies, in particular, to the field of audio and acoustics, for example, to so-called "high-fidelity" or Hi-Fi audio systems. The present invention applies, more specifically, to suspensions and loudspeakers for acoustic enclosures whose closed acoustic chamber has a small volume compared to the product of the surface area of ​​the entire diaphragm and its maximum excursion. In other words, it applies to loudspeakers designed to achieve large excursion relative to their size. State of the art

[0002] Generally, the external suspension 10 of a loudspeaker is a half-roll as shown in Figure 1(in perspective) and in Figure 2 (Side view). A loudspeaker with this suspension 10 is placed in a small volume of air within a sealed enclosure. figure 1 Circular lines equidistant from the external support plane of suspension 10 have been added to aid the perception of the semi-torus shape of suspension 10.

[0003] With a small volume closed load, a large displacement of the membrane connected to the suspension 10 causes a non-negligible change in the internal volume V of the closed load and, consequently, in the internal static pressure P. These two values ​​are linked by Laplace's law: PV γ< =C 1 , formula in which C 1 is a constant and γ=1.4 in the case of air.

[0004] We can therefore deduce: P x = P 0 V 0 / V 0 + S . x 1.4 formula in which: x: displacement of the membrane (in positive and negative, x=0 being the rest position), P 0: static pressure at equilibrium (x=0), V 0: internal volume of the enclosure (x=0) and S: radiation surface of the membrane.

[0005] In the case of a compact speaker enclosure where the product Sx is not negligible compared to V0, the variation in internal pressure causes a stress on the speaker's suspension with non-linear behavior. The impact of this pressure change is visible on the Figure 3 where suspension 11 shows a "normal" deformation, while suspension 12 is deformed by suction towards the internal volume 14 of the enclosure. This deformation of membrane 12 causes loud audible unwanted noise. figure 3 , line segment 13 represents the rest position of suspensions 11 and 12. Arrow 15 represents the imposed displacement of suspensions 11 and 12.

[0006] This phenomenon appears in particular when the front or rear of the loudspeaker is placed in a closed enclosure, and the loudspeaker is subjected to significant excursions 15.

[0007] To overcome this drawback, current external suspensions, found on many loudspeakers, have some of the following characteristics: suspensions of constant thickness, thick, which ensures their rigidity in bending; suspensions of constant thickness, with very stiff materials, also increasing their rigidity in bending; suspensions with variable thicknesses; suspensions with particular geometries, in order to reduce modes of vibration at particular frequencies; and suspensions with particular geometries, in order to reduce the "buckling" which appears during strong excursions (accumulation or rarefaction of matter for a geometry with revolution).

[0008] Current solutions have numerous drawbacks. Firstly, increasing the suspension thickness increases the mass of the moving parts, reducing the speaker's efficiency. Secondly, increasing the suspension stiffness raises the speaker's resonant frequency, making it more difficult to reproduce low frequencies without distortion. Furthermore, suspensions with variable designs, as currently available, do not eliminate the suction / vacuum created within the suspension.

[0009] Furthermore, high-fidelity loudspeakers are generally supported by a fixed stand designed to direct them towards the listener. Other loudspeakers are mounted on wall brackets with two degrees of rotational freedom, allowing them to be oriented in all directions within a cone of limiting directions. These brackets are complex and expensive. Small loudspeakers, such as those called Bluetooth speakers (a registered trademark), named after the communication protocol with an acoustic signal source, such as a mobile phone, are supported only by gravity, which limits their positioning capabilities. In particular, these speakers cannot be supported by a vertical surface, such as a wall. Ribbed suspensions are described in US patents 2015 / 139477 A1, 2018 / 242086 A1, 7275620 B1, and 2010 / 158306 A1. Description of the invention

[0010] The present invention aims to remedy all or part of these drawbacks.

[0011] Accordingly to a first aspect, the present invention aims at a suspension according to claim 1. Other embodiments are defined in the dependent claims.

[0012] The inventors discovered that this edge structure, with a radius of curvature and terminating on the straight line of the suspension's outer flank, exhibits good resistance to deformations caused by the pressure drop inside the enclosure during suspension movement. The curvature of the edge stiffens the outer, or front, face of the suspension, and the intersection of the edge with the outer flank stiffens that outer flank.

[0013] The invention provides a flexible and lightweight suspension that minimizes the mass and stiffness of the loudspeaker's moving assembly. In particular, the present invention eliminates the phenomenon of depression observed in the suspension, which generates unwanted noise at suspension travels exceeding those permitted with suspensions known in the prior art.

[0014] In some embodiments, the circular part of the rib edge has a radius between 80% and 120 % of a radius of at least one said arc of the general surface of the suspension.

[0015] In some embodiments, the edge includes a straight line segment connecting its circular portion to a straight line segment on the outer flank. This straight line on the rib edge increases the angle between this edge and the flank line of the suspension, thereby increasing the stiffness of this flank.

[0016] In some embodiments, the minimum angle between the flanks of the rib, along a cutting plane parallel to the axis of symmetry, is between 65 degrees and 105 degrees.

[0017] This arrangement allows for the optimization of the suspension weight while maintaining the desired mechanical properties of resistance to depression.

[0018] In embodiments: the height of the rib flanks, measured parallel to the axis of symmetry, is between one-quarter and one-half of the suspension height measured from its crown to its apex; the angle formed between the bond line segment and the straight line segment of the outer flank is between 90 degrees and 135 degrees; the distance between the lips of two consecutive ribs on the surface possessing rotational symmetry is less than or equal to the maximum width between the lips of a rib; the distance between the lips of two consecutive ribs on the surface possessing rotational symmetry is between one-third and two-thirds of the maximum width between the lips of a rib; the maximum width between the lips of a rib is greater than one-fifth of the radial extension of the entire surface by at least one arc of a circle in the cross-section of the surface possessing rotational symmetry by a plane passing through its axis.the height of the straight line segment of the outer flank, measured parallel to the axis of symmetry, is between one quarter and the full height of the suspension measured from the crown to the top of the suspension, the height of the straight line segment of the flank, measured parallel to the axis of symmetry, is greater than the maximum height of the edge furthest from the surface possessing rotational symmetry, and / or the suspension is thermoformed and made of resin-impregnated fabric or foam.

[0019] Each of these features further improves the suspension's travel capacity and, in the case of the last one, the ease and cost of manufacturing the suspension.

[0020] According to a second aspect, the present invention relates to a loudspeaker, according to claim 15, comprising a suspension which is the subject of the invention.

[0021] Thanks to these arrangements, by rotating the enclosure and the first mechanical interface around the second axis of rotation and the support, the direction of the first axis of sound wave emission is changed. This allows for the selection of an orientation with a single degree of rotational freedom between the support and the enclosure. Alternatively, the first axis of sound wave emission can be kept essentially unchanged while changing the type of support, for example, from a support placed on a flat horizontal surface to a wall mount.

[0022] In some embodiments, one of the mechanical interfaces has at least one bump oriented towards the other mechanical interface and this other mechanical interface has at least one hollow complementary to said bump.

[0023] Thus, the rotation of the shell around the support presents preferred directions in which each bump is housed in a hollow.

[0024] In some embodiments, the first axis and the second axis are coplanar.

[0025] Thus, the center of gravity of the shell, which is substantially on the first axis, remains substantially at the same distance from the second axis and the stability of the enclosure on the support is kept substantially constant.

[0026] In some embodiments, the acute angle formed between the first axis and the second axis is between 40 and 50 degrees.

[0027] Thus, rotation around the second axis causes the first axis to traverse approximately a right angle.

[0028] In some embodiments, the support has a flat base, the sum of the acute angle formed between the first axis and the second axis and the acute angle formed between the second axis and the plane of the flat base of the support is between 80 and 100 degrees.

[0029] Thanks to these arrangements, when the base of the support is vertical, for example against a wall, the first axis of emission of sound waves can be substantially horizontal.

[0030] In some embodiments, the contact surface between the first mechanical interface and the second mechanical interface has a general shape of a truncated cone, a truncated sphere or a truncated torus.

[0031] In some embodiments, the return piece comprises a helical spring and two parts having, respectively, a complementary thread and tapping, configured to compress the helical spring.

[0032] Thus, the restoring force exerted on the interfaces is regularly distributed over their contact surface.

[0033] In some embodiments, the return piece supporting the first mechanical interface and the second mechanical interface includes at least one magnet.

[0034] Thanks to these arrangements, the shell and the support are held in contact by magnetism, which allows for easy disassembly.

[0035] In some embodiments, the means for transmitting electrical signals through the mechanical interfaces includes a light passing through the two interfaces, through which a cable passes.

[0036] Thanks to these arrangements, the cable is free to rotate relative to the support, which avoids mechanical stresses that could damage electrical connections.

[0037] In some embodiments, the means for transmitting electrical signals through the mechanical interfaces includes dry electrical contacts on each of the mechanical interfaces.

[0038] Thanks to these provisions, there is no constraint on the number of turns that one of the mechanical interfaces can make on the other.

[0039] In some embodiments, the support has a plane of symmetry, a base perpendicular to this plane of symmetry and an orthogonal projection onto this plane of symmetry of general "L" shape, the projection of the base forming the horizontal part of this "L", the plane of the base being perpendicular to the first axis in a particular respective position of the first interface and the second interface.

[0040] Thanks to these arrangements, when the base of the support is vertical, for example against a wall, the first axis of emission of sound waves can be horizontal.

[0041] The specific technical features of the various aspects of the invention are intended to be combined to provide the advantages detailed above. Brief description of the figures

[0042] Other advantages, purposes and special features of the invention will become apparent from the following non-limiting description of at least one particular embodiment of the loudspeaker that is the subject of the present invention, with reference to the accompanying drawings, in which: There figure 1 represents, in perspective, a prior, or external, suspension of the earlier art, The figure 2 represents, schematically and in side view, the suspension illustrated in figure 1 , There figure 3 represents, in section, deformations of front suspensions of the prior art, The figure 4 represents, in perspective, a particular embodiment of a suspension that is the subject of the invention, The figure 5 represents, in partial top view, the suspension illustrated in figure 4 , There figure 6 represents cup AA identified in figure 5 , There figure 7 represents the BB cup identified in figure 5 , There figure 8represents a side view of the suspension illustrated in figures 4 to 7 , There figure 9 represents, schematically, a cross-sectional view of an enclosure including the suspension illustrated in figures 4 to 8 , There Figure 10 represents, in sections along two different planes passing through the axis of symmetry of the suspension, the general surface of the membrane illustrated in figure 9 , outside the ribs, and the lower edge of the rib illustrated in figure 9 , There figure 11 This represents, in axial section, a particular embodiment of an enclosure in a configuration placed on a plane. figure 12 represents, in axial section, the enclosure illustrated in figure 11 , in a configuration supported by a vertical wall, The figure 13 represents, enlarged, a circular part, labeled "C", of the figure 11 , There figure 14 represents, in perspective, a support for the enclosure illustrated in figures 11 to 13 and The figure 15represents, in perspective, a portion of the enclosure's shell illustrated in figures 11 to 14 . Description of the embodiments of the invention

[0043] The present description is given by way of non-limiting attribution, each feature of an embodiment being able to be advantageously combined with any other feature of any other embodiment.

[0044] It should be noted from the outset that the figures 4 to 10 They are to scale, even if they may be at different scales. Throughout the description, "rear" refers to anything close to or facing the driver of a loudspeaker, and "front" refers to anything far from the driver. The central axis of the driver, which is also the axis of symmetry of the loudspeaker, is also an axis of a surface possessing rotational symmetry of a front suspension.

[0045] For an element with a central axis, especially an axis of symmetry, what is far from this axis is called "external" and what is closer to this axis is called "internal".

[0046] The "height" of an element is defined as the measurement of the orthogonal projection of that element onto axis 36, oriented from back to front. The origin of this height measurement is the plane of intersection of a bond line and a straight line on the external side, a plane perpendicular to the axis of symmetry of the suspension (see description of the Figure 10 ). THE figures 4 And 6 à 10are oriented vertically. The "length" of an element is defined as the measure of its orthogonal projection onto a line 37 perpendicular to axis 36 and passing through that element. The "width" of an element is defined as the measure of its orthogonal projection onto a line 38 perpendicular to the line 37 used to measure length, and in a plane perpendicular to axis 36. Such lines 36 and 37 are represented in figure 4 for the length and width measurements of a rib 26.

[0047] THE figures 1 to 3 , which relate to earlier art, have already been described.

[0048] It is recalled here that a surface exhibiting rotational symmetry is a surface invariant under rotation by a given angle around a fixed axis, here the axis 36. In the embodiment illustrated in the figures, this general surface 45 of the suspension 20 also exhibits revolutional symmetry, that is to say that it is invariant under rotation by any angle around the axis 36.

[0049] As illustrated in figures 6 And 10 In the embodiment illustrated in the figures, the loudspeaker suspension 20 comprises, within a general surface 45 having rotational symmetry about the axis 26, a cross-section by a plane passing through this axis 36, outside the ribs. This cross-section comprises, successively from furthest to closest to the axis 36 and connected to each other by angles: a line segment 21 called "bonding" corresponding to a bonding zone, a straight line segment 22, called "external side" corresponding to an external side of the suspension and at least one arc of a circle 23, corresponding to the front face of the suspension 20, that is to say the part of the suspension 20 furthest from the plane perpendicular to the axis 36 and passing through the intersection of lines 21 and 22 (due to the definition of heights given above, this is the top of the suspension.

[0050] In this embodiment, this section also includes a circular arc 24 continuing the circular arc 23 and a straight line segment 25 connected to the circular arc 24.

[0051] Since, in this embodiment, the general surface 45 of the suspension 20 also exhibits rotational symmetry, in the following description: the bonding line segment 21 is part of a bonding crown or truncated cone, the external flank straight line segment 22 is part of a truncated cone, the line segments 23 and 24 are part of truncated tori, the straight line segment 25 is part of a truncated cone.

[0052] The invention is adaptable to embodiments in which the overall surface of the suspension does not exhibit rotational symmetry, for example, an overall surface whose orthogonal projection onto a plane perpendicular to axis 36 is polygonal. This adaptation by those skilled in the art is straightforward from the following description, the radial cutting plane considered to define the line segments 21 to 25, angle 39, and vector 32, being then perpendicular to a longer side of the regular polygon thus defined.

[0053] The crown 21 can be flat as in the figures 4 to 10, in the shape of a cone or a truncated sphere, for example.

[0054] In the embodiment shown in figures 4 to 8 And 10 The surface 45 comprises two frustums of torus 23 and 24. In other embodiments (not shown), the rotationally symmetric surface comprises a single frustum of torus or more than two frustums of torus. In the embodiment shown in figures 4 to 8 And 10 , the suspension 20 includes, as an extension of the truncated torus 24 closest to the axis 36, a truncated cone 25 serving for the connection with the speaker diaphragm and, possibly, to the moving part of the speaker motor.

[0055] The suspension 20, which is the subject of the invention, has multiple reinforcing ribs 26 generally in a "V" shape (see figure 8These ribs 26 are found a large number of times around the perimeter of the suspension 20. In this surface 45, which has rotational symmetry, at least one rib 26 is thus formed, hollow within the volume of at least one truncated torus 23 and 24. At least one rib 26 exhibits: an edge 27 away from the general surface 45 of the suspension 20, this edge 27 having a circular part 31 and flanks 28 connecting this edge 27 to the general surface 45.

[0056] At the top of the Figure 10 is represented a section, by a plane containing the axis 36, of the general shape 45, that is to say the section of the suspension 20 outside the ribs 26. At the bottom of the Figure 10 is shown a cross-section, by another plane containing axis 36, of the suspension 28, a cross-section passing through edge 27, as well as, in dashed lines, the cross-section illustrated at the top of the Figure 10, for the purpose of comparing dimensions. The dashed lines with regular segments relate to the general shape 45. The dashed lines with alternating long and short segments relate to the edge 27.

[0057] We observe, Figure 10 , that the edge 27 opens onto the straight line segment 22 of the external flank, in the central third of this segment, that is to say at a height h41 between one third and two thirds of the height h22 of the segment 22 and, preferably, at a height h41 between 40% and 60% of the maximum height h22 of this straight line segment 22.

[0058] Preferably, the edge 27 has, at its external end, an external straight line segment 41. This straight line segment 41 of the edge 27 is, preferably, contained in a plane perpendicular to the axis 36 of symmetry of the suspension 20.

[0059] Preferably, and as illustrated in figure 7, an external straight line segment 41 of the edge 27, connects its circular part 31 to the truncated cone 22.

[0060] In the embodiment illustrated in figures 1 to 10 : The height h22 is between one-quarter and the entirety, preferably between half and three-quarters, of the maximum height h23 of the suspension; the outer flank 22, stiffened approximately at the midpoint of its height by the end of the edge 27, can thus be particularly high compared to suspensions with ribs of the prior art; the maximum height of the edge 27, h31, is between 75% and 125% of the height h22 and preferably between 85% and 110% of the height h22, edge 27 opens onto the flank line 22 at a height h41 between one-quarter and half of the maximum height h23 of the suspension 20, the maximum height h31 of edge 27 is between half and three-quarters of the maximum height h23 of the suspension 20, edge 27 includes a straight line segment 42 connecting the circular part 31 to the inner flank, in a circular part 24 of the general shape 45 of the suspension 20, thus stiffening this inner flank in the same way that the opposite end of edge 27 stiffens the outer flank 22, at least one straight line segment, 41 and / or 42, of edge 27 is in a plane perpendicular to the axis of symmetry 36, the inner end (on the side of axis 36) of edge 27 is approximately at the same height h41 that the outer end of this edge 27, edge 27 is symmetrical with respect to an axis parallel to the axis 36 of symmetry of the suspension 20,the angle between at least one straight line segment, 41 and / or 42, of the edge 27 and the circular part 31 of the edge 27 is between 20 degrees and 40 degrees, preferably 30 degrees, the angle between the straight line segment of the outer flank 22 and the front circular part 23 of the general shape 45 is between 30 degrees and 60 degrees, preferably about 45 degrees, thus stiffening the connection of the outer flank 22 and the toroidal front face of the suspension 20, the radii R1 and R2 are substantially equal to two-thirds of the distance d45 between the bonding line segment 21 and the line segment 25 connecting to the diaphragm or the loudspeaker motor, i.e., between 55% and 75% of this distance d45, the distance d27 between the ends of the edge 27 is between 75% and 90% of the distance d45, and the Circular part 31 of edge 27 extends over 50 degrees to 70 degrees of the circle 43 defined by the radius R2.

[0061] Each of these features aims to optimize the distribution of forces and points (intersection of lines), lines (edges) of rigidity, to resist the negative or positive pressure of the enclosure's internal volume on the inner and outer sides and on the toroidal portion of the suspension 20, during the movement of the loudspeaker diaphragm. This distribution maximizes the diaphragm's ability to accommodate large deflections. In other embodiments (not shown), the 13 technical features listed above are not reproduced, or are only partially reproduced.

[0062] In the embodiment illustrated in the figures 4 to 10, all the ribs 26 are identical. In other embodiments, the ribs are different, for example with parallel edges 27 on portions of the suspension or with ribs whose geometric characteristics alternate between the ribs.

[0063] As illustrated in figure 7 , the edge 27 of at least one rib 26 has a circular part 31 having a radius R2 between 80% and 120%, preferably between 90% and 110%, and more preferably between 95% and 105% of a radius R1 of an arc of a circle 23 corresponding to a truncated torus of the surface 45.

[0064] In figure 7, the radii R1 and R2 are equal. More precisely, in a cutting plane parallel to the plane of edge 27, a circular segment 30 (in dashed lines) of a frustum of a torus (in this embodiment, the frustum of a torus 23) corresponds, by translation by a vector 32, to at least a part 31 (in dashed lines) of edge 27. As can be seen in figure 7 , this is the circular part 31 of the edge 27.

[0065] As can be seen in figure 7 The arc covered by the circular part 31 represents less than a quarter of a circle and, preferably, about one-sixth of a circle, i.e., between 45 degrees and 75 degrees. The complete circle 43, a portion of which is covered by part 31 of edge 27, is shown in figure 7 , in discontinuous lines.

[0066] Preferably, and as illustrated in figure 7, an internal straight line segment 42 of the edge 27, connects its circular part 31 to the trunk of the torus 24. Preferably, as illustrated in figure 7 , the straight line segment 42 reaches the torus truncated 24 approximately halfway between the height of the entire torus 24 and the cone truncated 25.

[0067] These preferential positions in the middle of the heights correspond to the maximum reinforcement of the truncated cone 22, for part 41, and of the whole of the truncated torus 24 and the truncated cone 25, for part 42.

[0068] Preferably, the torus 23 with radius R1 close to or equal to radius R2 of edge 27 is the torus 23 that reaches the maximum height, the apex, of the suspension 20 (at the top in figures 4 And 6 à 10The vector 32 is preferentially oriented towards the interior volume of the enclosure containing the loudspeaker. Thus, the component of the vector 32 in a plane containing the axis 36 is oriented towards the portion of the axis 36 located within the enclosure. In other words, the circular segment 31 is closer to the axis 36 than the circular segment 30.

[0069] Preferably, the flanks 28 form a constant angle 35 along the entire length of the edge 27, an angle measured in a plane: parallel to axis 36 and perpendicular to the plane of edge 27 (plane passing through axis 36 when the edges are radial, as in the embodiment illustrated in figures 4 to 10 ).

[0070] As illustrated in figure 8, this angle 35, which is the minimum angle between the flanks 28 of the rib 26, according to a cutting plane parallel to the axis of symmetry 36 and including the line 38, is substantially right, that is to say between 65 degrees and 105 degrees, preferably between 75 degrees and 95 degrees.

[0071] As illustrated in figures 6 And 7Preferably, the height of the sides 28 of the rib 26, measured parallel to the axis of symmetry 36, is between one-quarter and one-half, and preferably between one-quarter and one-half, for example one-third, of the height of the suspension 26, measured from its crown 21 to its apex. The inventors have found that this height, equal to h23 - h31, or the depth of the ribs, of the rib 26 influences the ability of the suspension 20 to resist the restoring pressure of the enclosure's internal volume: the greater this height, the better this ability. However, if this height is too great, the suspension 20 can no longer move properly parallel to the loudspeaker axis, which then reduces the loudspeaker's operating range in the low frequencies.This height remains the same over a good part of the rib 26, which avoids a straight cut through the suspension 20, a cut which could cause problems during the physical molding of the material constituting the suspension 20.

[0072] As illustrated in figure 6 Preferably, the obtuse angle 39 formed between the plane perpendicular to the axis 36 and the truncated cone 22 which joins the crown 21 is between 90 degrees and 135 degrees and, even more preferably, between 90 degrees and 110 degrees.

[0073] The lips 29 of the rib 26 are the connecting edges between the flanks 28 of this rib 26 and the surface 45. As illustrated in Figures 5 And 8 Preferably, the distance 34 between the lips 29 of two consecutive ribs 26 on the surface 45 is less than or equal to the maximum width 33 between the lips 29 of a rib 26 and preferably substantially equal to half of this maximum width 33.

[0074] As illustrated in figure 5 Preferably, the maximum width 33 between the lips 29 of a rib 26 is greater than one fifth of the radial extension (or length) of the set of trunks of tori 23 and 24 and one quarter of the length of a rib 26.

[0075] As illustrated in figures 6 And 7 Preferably, the height of the truncated cone 22 touching the crown 21, measured parallel to the axis 36 of the surface 45, is between one quarter and the total height of the suspension measured from the crown 21 to the top of the suspension.

[0076] In the embodiment illustrated in figures 4 to 10, the edges 27 are radial, that is to say that the plane which contains an edge 27 passes through the axis 36. However, in other embodiments (not shown), the planes of the edges form, at their midpoint, an equal angle with a plane passing through the axis 36 of the suspension 20 and through the midpoint of the edges.

[0077] As indicated at the beginning of the description of the embodiment illustrated in the figures 4 to 10 The invention is adaptable to embodiments in which the overall surface of the suspension does not exhibit rotational symmetry, for example, an overall surface whose orthogonal projection onto a plane perpendicular to axis 36 is polygonal. This adaptation by a person skilled in the art is straightforward from the following description, the radial cutting plane considered to define the line segments 21 to 25, angle 39, and vector 32, being then perpendicular to a longer side of this polygon.

[0078] According to this generalization: a) the suspension has a general surface having rotational symmetry about an axis 36, the cross-section of which by a plane passing through this axis comprises, successively from furthest to closest to the axis and connected to each other: a line segment 21 corresponding to a bonding zone, a straight line segment 22, and at least one arc of a circle 23 and 24; b) the rib 26 has: an edge 27 distant from the surface having rotational symmetry, an edge having at least one radius of said arc of a circle, and flanks 28 connecting this edge to this surface; c) in embodiments, the angle 39 formed between the line segment 21 corresponding to the bonding zone and the straight line segment 22 which is connected to it in the cross-section of the surface having rotational symmetry by a plane passing through its axis 36 is between 90 degrees and 135 degrees;d) in embodiments, the maximum width 33 between the lips 29 of a rib 26 is greater than one fifth of the radial extension of the assembly 23 and 24 by at least one arc of a circle in the cross-section of the surface 45 by a plane passing through its axis 36; e) in embodiments, the height of the straight line segment 22 which is connected to the line segment 21 corresponding to the bonding zone in the cross-section of the surface 45 by a plane passing through its axis 36, measured parallel to this axis 36, is between one quarter and the total height of the suspension measured from the crown to the top of the suspension; and f) in embodiments, the height of the straight line segment 22 which is connected to the line segment 21 corresponding to the bonding zone in the section of the surface 45 by a plane passing through its axis 36, measured parallel to this axis, is greater than the height of the edge 27 of the rib 26. ;

[0079] In some embodiments, the suspension is thermoformed and made of resin-impregnated fabric or foam. This manufacturing method avoids altering the mass of the suspension, compared to a suspension without ribs, while increasing its resistance to deformation under the effect of negative pressure inside the enclosure.

[0080] There figure 9Figure 40 schematically represents a loudspeaker 40 comprising a suspension 20, the subject of the invention, and an enclosure 50 containing the loudspeaker 40. The present invention applies in particular to loudspeaker suspensions whose enclosed acoustic loading has a volume less than ten times the product of the surface area of ​​the entire diaphragm and its maximum excursion. The suspension 20 is thus integrated into a loudspeaker 40 designed to withstand, without acoustic distortion, large excursions relative to its size. This loudspeaker 40 is inserted into a closed enclosure 50. Compared to a suspension illustrated in figures 1 and 2 Using the same material and material thickness, for the same background noise, the improvement in the resistance to pressure drop of a given internal enclosure volume is as follows: Conventional half-roll suspension: 1 mm maximum displacement, Suspension subject of the invention: 4.5 mm displacement for a slight suction to form.

[0081] The invention allows the use of a flexible and lightweight material. The invention allows the use of this material when the loudspeaker is loaded by a small enclosed volume (compared to its size). The invention allows the use of thermoformable or injection-molded materials. The invention only slightly increases the mechanical stiffness of the suspension as it is usually measured on a loudspeaker (Kms). The invention allows for a linear stiffness as a function of displacement (Kms(x)) within its operating range.

[0082] It is noted that the figures 11 to 15 are to scale, even if they may be at different scales.

[0083] We observe, in figures 11 to 13A steerable acoustic enclosure 60 comprises at least one loudspeaker 74 having a first axis of sound wave emission 63. It should be noted that the enclosure 60 may thus comprise a single loudspeaker or several coaxial loudspeakers. The enclosure 60 also comprises a shell 62 containing each loudspeaker 74. The shell 62 also comprises a first mechanical interface 65 having rotational symmetry about a second axis 64 not parallel to the first axis 63.

[0084] A support 61 presents a second mechanical interface 66 complementary to the first mechanical interface 65. A means 68, 69, and 70 for transmitting electrical signals through the mechanical interfaces 65 and 66 comprises, in this embodiment, parts 68 and 69, described later, surrounding a passage along the second axis 64 and a cable 70 running through this passage. The parts 68 and 69 thus form a passage, 68 and 69, for the cable 70 passing through the mechanical interfaces 65 and 66 along the second axis 64. A connecting piece 67 supports the first mechanical interface 65 and the second mechanical interface 66.

[0085] As can be seen in relation to the Figures 11 And 12By rotating the shell 62 and the first mechanical interface 65 around the second axis of rotation 64 and the support 61, the direction of the first axis 63 of sound wave emission is modified. An orientation with a single degree of rotational freedom between the support 61 and the shell 62 of the enclosure 60 can thus be chosen. Alternatively, as illustrated in Figures 11 And 12 , we can keep substantially unchanged the first axis 63 of sound wave emission while changing the type of support 61, by going from a support 61 placed on a flat horizontal surface ( figure 11 ) to a wall bracket on a vertical wall 73 ( figure 12 ).

[0086] In the embodiment shown in the figures 11 to 15The contact surface between the first mechanical interface 65 and the second mechanical interface 66 has a general truncated cone shape. In other embodiments (not shown), this contact surface has a general truncated sphere shape, a truncated torus shape, or any other surface of rotation, or even revolution, around the second axis 64.

[0087] Preferably, this general contact surface of the mechanical interfaces also exhibits a rotational symmetry, that is to say, it is invariant under rotation by any angle around the second axis 64.

[0088] In embodiments such as that represented in the figures 11 to 15One of the mechanical interfaces, here the second mechanical interface 66, has at least one bump 76 oriented towards the other mechanical interface, here the first mechanical interface 65, and this other mechanical interface 65 has at least one recess 75 with a shape complementary to said bump 76. In other embodiments (not shown), it is the first mechanical interface of the shell that has at least one bump, and it is the second mechanical interface that has at least one recess with a shape complementary to said bump. As illustrated in Figures 14 and 15 , in the embodiment represented in the figures 11 to 15 Eight hollows 75 and eight bumps 76 are implemented. In other embodiments (not shown), the number of hollows is greater than the number of bumps.

[0089] The bumps, at their intersection with the general shape of the mechanical interface that supports them, form an angle preferably greater than 90 degrees, for example 135 degrees, so that the passage, by rotation of the shell 62 around the axis 64, from one bump 76 to the next recess is facilitated. The return piece 67 ensures that each bump 76 is held in a recess 75 without manual effort on the mechanical interfaces. Of course, whether or not bumps and recesses are present, the respective rotational position of the mechanical interfaces is maintained by the return piece 67. The presence of the bumps 76 and recesses 75 nevertheless ensures ease of use by assisting the user in finding such a relative position for the shell 62 and the support 61. Thus, the rotation of the shell 62 around the support 61 presents preferred directions in which each bump 76 is housed in a recess 75.

[0090] Preferably, the first axis and the second axis are coplanar (in the cutting plane of the Figures 11 And 12 ), which gives the enclosure 60 a plane of symmetry in the configurations illustrated in Figures 11 And 12 Preferably, as illustrated in Figures 11 And 12 The acute angle formed between the first axis 63 and the second axis 64 is between 40 and 50 degrees. Thus, rotation around the second axis causes the first axis to traverse approximately a right angle.

[0091] In the embodiment illustrated in figures 11 to 13The return piece 67 comprises a helical spring and two parts 68 and 69 having, respectively, a complementary tapped hole and thread (both referenced as 71), configured to compress the helical spring. Part 69 being integral with the first mechanical interface 65, once the cable 70 has passed successively through this part 69, the second interface 66, the helical spring 67, and part 68, the assembly of the support 61 onto the shell 62, the positioning of the cable passage 70, and the compression of the spring 67 are carried out simultaneously by rotating the thread of part 68 on the tapped hole of part 69. Preferably, the cable passage parts 68 and 69 have a smooth internal wall 72 through which the cable 70 passes, and the cable has an external diameter smaller than the internal diameter of this smooth wall 72.The cable 70 is thus free to rotate relative to the support 61, which avoids mechanical stresses that could damage the electrical connections. In some embodiments (not shown), the return piece includes a flexible elastic strip, for example, metallic or elastomer. In other embodiments, the return piece supporting the first and second mechanical interfaces includes at least one magnet (not shown).

[0092] As described above, in the embodiment represented in the figures 11 to 15The means for transmitting electrical signals through the mechanical interfaces 65 and 66 comprises parts 68 and 69, which surround a light extending along the second axis 64, and a cable 70, which runs along this light. In other embodiments, the means for transmitting electrical signals through the mechanical interfaces includes an axial connector. In some embodiments, the means for transmitting electrical signals comprises dry electrical contacts positioned opposite each other on the two mechanical interfaces 65 and 66, in each of a plurality of orientations of the mechanical interfaces 65 and 66 around the second axis 64. For example, the electrical signals pass through the bumps 76 and the recesses 75. Preferably, bumps 76 and recesses 75 are dedicated to signals of a first polarity and positioned at a first distance from the second axis 64.Other bumps 76 and other hollows 75 are dedicated to signals of a second polarity and positioned at a second distance, strictly greater than the first distance, from the second axis 64.

[0093] In the embodiment illustrated in figures 11 to 14 , support 61 presents a plane of symmetry (the cutting plane of the Figures 11 And 12 ), a base 77 perpendicular to this plane of symmetry, and an intersection with this plane of symmetry in the general shape of "L", visible in Figures 11 And 12 whose projection of the base 77 forms the horizontal part of this "L". The plane of the base 77 is substantially perpendicular to the first axis 63 in a particular respective position (illustrated in figure 12) of the first interface 65 and the second interface 66. In other words, the sum of the acute angle formed between axes 63 and 64 and the acute angle formed between axis 64 and the plane of the base 77 is equal to 90 degrees, for example, to within ±10 degrees. In the embodiment illustrated in figures 11 to 15 The acute angle formed between axes 63 and 64 is less than 45 degrees, for example 43 degrees, and the acute angle formed between axis 64 and the plane of base 77 is greater than 45 degrees, for example 47 degrees. Thus, when the base 77 of support 61 is vertical, for example against a wall 73, the first axis 63 of sound wave emission can be horizontal, as illustrated in figure 12 .

[0094] The object of the invention is defined by the following claims.

Claims

1. Suspension (20) of a speaker (40), which suspension comprises, within an overall area (45) having rotational symmetry around an axis (36), an overall area whose cross-section passing through this axis comprises, successively from the farthest from to the closest to the axis and connected to each other by angles: - a line segment (21), referred to as "bonding", corresponding to a bonding area, - a straight line segment (22), referred to as "outer side", corresponding to an outer side of the suspension, and - at least one arc of circle (23, 24) corresponding to the front surface of the suspension; at least one rib (26), recessed into this surface, having: - an edge (27) farthest from the overall area of the suspension, this edge comprising a circular portion (31), and - sides (28) connecting this edge to this area; which suspension is characterised in that the edge (27) opens onto the outer side line segment (22), in the middle third of this segment.

2. Suspension according to claim 1, wherein the circular portion (31) of the edge (27) of the rib (26) has a radius (R2) that is between 80% and 120% of a radius (R1) of at least one said arc of circle (23) of the overall area (45) of the suspension.

3. Suspension (20) of a speaker (40) according to claim 2, wherein said radii (R1, R2) are between 55% and 75% of the distance (d45) between the bonding line segment (21) and the line segment (25) of connection with the cone or motor of the speaker.

4. Suspension (20) of a speaker (40) according to one of claims 2 or 3, wherein the edge (27) comprises a straight line segment (41) connecting its circular portion to an outer side straight line segment (22).

5. Suspension (20) of a speaker (40) according to one of claims 1 to 4, wherein the minimum angle (35) between the sides (28) of the rib (26), according to a cross-section plane parallel to the axis of symmetry (36), is between 65 degrees and 105 degrees.

6. Suspension (20) of a speaker (40) according to one of claims 1 to 5, wherein the height of the sides (28) of the rib (26), measured parallel to the axis of symmetry (36), is between one quarter and one half of the height of the suspension measured from its ring to its top.

7. Suspension (20) of a speaker (40) according to one of claims 1 to 6, wherein the distance (34) between the lips (29) of two consecutive ribs (26) within the area (45) having rotational symmetry is less than or equal to the maximum width (33) between the lips of a rib.

8. Suspension (20) of a speaker (40) according to one of claims 1 to 7, wherein the height (h22) of the side straight line segment (22), measured parallel to the axis of symmetry (36) is greater than the maximum height (h31) of the edge (27) farthest from the area (45) having a rotational symmetry.

9. Suspension (20) of a speaker (40) according to one of claims 1 to 8, thermoformed and made of resin impregnated fabric or of foam.

10. Suspension (20) of a speaker (40) according to one of claims 1 to 9, wherein the height (h22) of the outer side straight line (22) is between one quarter and 100%, preferably between one half and three quarters, of the maximum height (h23) of the suspension.

11. Suspension (20) of a speaker (40) according to one of claims 1 to 10, wherein the maximum height (h31) of the edge (27) is between 75% and 125% of the height (h22) of the outer side straight line (22), and preferably is between 85% and 110% of this height of the outer side straight line (22).

12. Suspension (20) of a speaker (40) according to one of claims 1 to 11, wherein the maximum height (h31) of the edge (27) is between one half and three quarters of the maximum height (h23) of the suspension (20).

13. Suspension (20) of a speaker (40) according to claim 4 or one of claims 5 to 12 when they are dependent on claim 4, wherein at least one straight line segment (41, 42), of the edge (27) is in a plane perpendicular to the axis of symmetry (36).

14. Suspension (20) of a speaker (40) according to one of claims 1 to 13, wherein the inner end of the edge (27) is approximately at the same height (h41) as the outer end of this edge.

15. Speaker (40) comprising a suspension (20) according to one of claims 1 to 14.

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