REGULATION UNIT FOR THE BREATHING MASK OF AN AIRCRAFT CREW MEMBER

Description

Technical field of the invention

[0001] This disclosure relates to a set of regulations for an aircraft crew member's respirator mask. Prior art

[0002] As is known, such a respiratory mask regulator assembly for an aircraft crew member includes: a support; a mode selection button mounted pivoting on the support about an axis of rotation, the axis of rotation being arranged perpendicular to said support; a radial direction, a transverse direction and the axis of rotation forming a right-handed trihedron; said selection button being capable of pivoting between at least a first position, a second position and a third position, the second position being positioned between the first and third positions;a regulator intended to be supplied by a breathing gas source and adapted to supply a breathing cavity in at least three of the following operating modes: a) when the mode selector knob is in the first position, the regulator supplies the breathing cavity as long as the pressure in the breathing cavity is not greater than a first relative pressure with respect to the ambient pressure, b) when the mode selector knob is in the second position, the regulator supplies the breathing cavity as long as the pressure in the breathing cavity is not greater than a second relative pressure with respect to the ambient pressure, the first pressure being greater than the second pressure, c) when the mode selector knob is in the third position, the regulator supplies the breathing cavity with breathing gas diluted with air.

[0003] The first position, "EMER," corresponds to "EMERGENCY" mode. Select it in case of smoke or fire in the cockpit. The second position, "100%," corresponds to "100%" mode. It provides protection against hypoxia.

[0004] The third position, "N," corresponds to "NORMAL" mode. It allows you to limit oxygen consumption when using a preventative oxygen mask or during a decompression stop on a descent profile. The selection button is in the second position (100%) by default. This second position (100%) is located in the center between the first and third positions.

[0005] The mode selection button is not visible to the user when the mask is worn. Currently, the selection button is asymmetrical to allow the user to distinguish the direction of rotation leading to "EMERGENCY" mode from "NORMAL" mode by touch. The selection button also has lateral markings to allow verification of the selected mode by a third party. Thus, current respiratory masks incorporate means of providing information about the selected operating mode to the user, through the asymmetry of the button, and to third parties, using the lateral markings.

[0006] Despite this asymmetry, without significant knowledge and frequent use of the respirator, it is difficult to know the correct direction of rotation for switching between "EMERGENCY" and "NORMAL" modes. In particular, in a sudden emergency, the user could accidentally rotate the selector knob to "NORMAL" mode and lose protection against fumes and toxic gases. The user could also select the wrong operating mode if the information is not properly understood or if they react hastily.

[0007] Such a respiratory mask is disclosed by document EP 2937113. Furthermore, document WO 2017 / 044582 describes a combination respirator featuring a three-position lockable switch. Presentation of the invention

[0008] The purpose of this disclosure is to propose a control system designed to prevent accidental selection of the "NORMAL" mode instead of the "EMERGENCY" mode. This disclosure aims to increase the safety level of oxygen mask control systems by preventing misuse of the mode selection button. Summary of the invention

[0009] The invention relates to a control assembly for a respiratory mask according to claim 1.

[0010] The features described in the following paragraphs may optionally be implemented. They may be implemented independently or in combination with each other: The operating member is designed to move in the radial direction after pressure is applied to an actuating zone of the operating member, and the locking / unlocking device comprises a first stop designed to halt the movement of the operating member when the groove is aligned with the projection. The first stop is positioned opposite an end face of the locking finger at a distance from the projection substantially equal to the distance between the groove and the end face of the locking finger. The first stop is mounted on the support. The locking / unlocking device comprises a second stop designed to halt the rotation of the mode selection knob from the second position to the first position when the operating member is in the unlocked position, while allowing the rotation of the mode selection knob from the second position to the third position.The locking finger has an end face and a second lateral face opposite the first lateral face, in which a second stop is arranged, in the radial direction, between the first stop and the end face of the locking finger when the operating member is in the locked position, and; in the transverse direction, with respect to at least a portion of a second lateral face of the locking finger, when the operating member is in the unlocked position. The projection is a rib that has the shape of a circular arc in a plane of the support, said circular arc being centered on the axis of rotation.The operating mechanism comprises a lever mounted pivoting relative to the mode selection button about a first pivot axis, the first pivot axis being parallel to the axis of rotation; and wherein the mode selection button has a base extending perpendicularly to the axis of rotation and a peripheral rim having a through opening, and wherein at least a portion of the lever extends through the through opening. The mode selection button has a base extending perpendicularly to the axis of rotation and a peripheral rim, said peripheral rim being provided with a through cutout forming a tab connected to a portion of the peripheral rim by an axial portion; said tab being capable of pivoting about a pivot axis parallel to the axis of rotation by plastic deformation of said axial portion of the peripheral rim.The through-cut comprises a first cutout extending in a transverse direction, and a second cutout extending in the direction of the axis of rotation. The second cutout extends the first cutout and opens outside the mode selection button. The mode selection button has a base extending perpendicularly to the axis of rotation and a peripheral rim provided with a through-hole. The operating element in this rim comprises a push button having a head with an actuating area. The head is arranged in the through-hole. The push button is adapted to slide in a radial direction relative to the peripheral rim when the user presses on the actuating area.The locking finger is positioned between a portion of the push button and the support along the direction of the axis of rotation; said locking finger is fixed to the push button such that sliding the push button causes the locking finger to move along the radial Y direction. The locking / unlocking system comprises a support wall integral with the mode selection button, and an elastic element acting between the push button and said support wall to hold the push button in a locked position. The support wall extends at one end face of the push button and at the end face of the locking finger, said support wall forming the first stop. Brief description of the figures

[0011] [ Fig. 1 ] is a perspective view of a respiratory mask comprising a regulating assembly according to the present invention; [ Fig. 2] is a view of one face of the regulating assembly according to the invention, said face being identified by arrow II on the figure 1 , [ Fig. 3 ] is a side perspective view of a mode selection button and a cover of the control assembly according to a first embodiment of the invention; [ Fig. 4 ] is a perspective view of a portion of a cross-section of the mode selection button and the cover of the control assembly according to a first embodiment of the invention; [ Fig. 5 ] is a perspective view of part of a cross-section of the mode selector button and the cover according to a first variant of the first embodiment of the control assembly according to the invention; [ Fig. 6 ] is a perspective view of a portion of a cross-section of the mode selector button and cover according to a second variant of the first embodiment of the control assembly according to the invention; and [ Fig. 7] is a perspective view of part of a cross-section of a mode selection button and a cover of the control assembly according to a second embodiment of the invention. Detailed description of the invention

[0012] The drawings and description below contain, for the most part, elements of a definite nature. They may therefore not only serve to better understand this disclosure, but also contribute to its definition, if necessary. In this patent application, the terms "lower" and "upper" are defined with respect to the figures.

[0013] There figure 1 illustrates a breathing mask 1 arranged in a pressurized cabin 8 of a commercial aircraft intended to carry crew members and usually also passengers.

[0014] A device, preferably an isobaric type, pressurizes the cabin to maintain a pressure at or above a specific pressure, generally corresponding to an altitude between 1,500 and 2,400 meters. As the aircraft climbs, the cabin pressure becomes approximately equal to the pressure outside the cabin and decreases until it reaches this pressure. Under normal conditions, the cabin pressure is then maintained constant until the outside pressure falls below the pressure. The breathing mask is designed to provide the user with sufficient oxygen and protection from harmful substances in the event of incidents such as depressurization, the presence of toxic or similar gases, which prevent the cabin occupants from breathing normally.

[0015] The respiratory mask 1 includes a face cover 2 and a regulation assembly 1 according to a first embodiment of the invention.

[0016] The oronasal 2 face covering is designed to be applied in a substantially airtight manner to the user's face around their nose and mouth. The oronasal 2 face covering has a breathing cavity 4 into which the user breathes. The control assembly 1 according to the first embodiment comprises a bracket 10, a regulator, a mode selection button 20 pivotally mounted on the bracket 10 about a rotation axis Z, and a locking / unlocking device for the rotation of the selection button.

[0017] In this application, the "radial direction," the "transverse direction," and the "axial direction" are defined with respect to the axis of rotation Z. The transverse direction X, the radial direction Y, and the axis of rotation Z form a right-handed trihedron. The transverse direction X and the radial direction Y lie in a plane parallel to the support.

[0018] In the embodiment shown in the Figures 1 And 2 The support 10 includes a housing 13 and a cover 14 suitable for closing the housing. The housing 13 is equipped with a breathing gas supply port 6 visible on the figure 2 This orifice 6 is intended to receive the end of a tube to connect the regulator to a source of breathing gas containing essentially oxygen.

[0019] The regulator is housed in casing 13. It operates in three modes. In the first mode, called "EMERGENCY" mode, the regulator supplies breathing chamber 4 with breathing gas only until a slight overpressure is reached in breathing chamber 4 relative to the ambient cabin air pressure. This overpressure is generally between 3 mbar and 30 mbar. At the most common overpressure values, between 3 and 7 mbar, this pressure is barely felt by the user. Above 10 to 12 mbar, the overpressure requires a substantial additional effort from the user to breathe, which is quickly felt. In the second mode, called "100%" mode, the regulator supplies breathing chamber 4 with breathing gas only until it reaches approximately the ambient pressure.In practice, it is generally useful to plan to stop the supply to the breathing cavity before the breathing cavity reaches ambient pressure, so that there is a very slight depression (a few tenths of a mbar to a few mbar) in the breathing cavity 4.

[0020] The third breathing mode, called "NORMAL", differs from the second breathing mode in that the breathing cavity 4 is supplied with breathing gas diluted with air, generally ambient air, the proportion of which is usually a function in particular of the pressure in the cabin 8.

[0021] With reference to the figure 2The mode selector button 20 has a first position marked "EMER" and commands the regulator to operate in the first mode. The mode selector button 20 has a second position marked "100%" and commands the regulator to operate in the second mode. The mode selector button 20 has a third position marked "N" and commands the regulator to operate in the third mode. The center position of the selector button corresponds to the second position, 100%. In the embodiment shown in the figure 2 The third position, "N", is located to the right of the center position. Therefore, viewed from the front, the mode selection button 20 must be rotated counterclockwise to move from the second position (100%) to the third position (N).

[0022] In the illustrated embodiment, the Z-axis of rotation of the selection button extends substantially vertically when the user holds their head upright, so that the mode selection button 20 extends below the support 10. Of course, the mode selection button 20 could be positioned differently, for example, on the front of the support 10 and / or with a rotation axis extending substantially horizontally. As is known, the three positions of the mode selection button are discrete positions marked by notches.

[0023] The mode selection button 20 has a base 21, a peripheral rim 22 surrounding the base, and a stem 23 for attaching it to the support 10. The base 21 includes an opening surrounded by an axial ring 24 shown in the figure 4The retaining rod 23 is arranged in the opening. It forms the Z axis of rotation of the selection button 20. In the embodiment shown, the markings EMER, 100%, and N are located on the base 21 and on the peripheral edge 22 of the selection button. A reference mark 11a is located in the center of the width of the cover 14, and two lateral reference marks 11b are located on the edges of the housing 13 to indicate the position of the mode selection button 20. Only one lateral reference mark 11b is visible on the figure 1 .

[0024] The locking / unlocking device 30 is designed to lock and unlock the rotation of the mode selection button from the second position 100% to the third position N. The locking / unlocking device 30 includes an operating member 31 adapted to be moved between a locking position of the rotation of the mode selection button 20 to the third position N, and an unlocking position of the rotation of the mode selection button 20 to the third position N.

[0025] With reference to the figure 3The operating member 31 comprises a tab 32 formed by a through cutout in the peripheral rim 22 of the mode selector button 20. The tab 32 is adapted to pivot inward toward the button about a pivot axis parallel to the rotation axis Z by plastic deformation of an axial portion 34 of the peripheral rim. Thus, in this embodiment, the mode selector button 20 is made of a deformable plastic material such as, for example, a polyamide. Advantageously, the through cutout has a first cutout portion 26 extending along the transverse direction X and a second cutout portion 28 extending along the direction of the rotation axis Z. The second cutout portion 28 extends the first cutout portion 26 and opens outward from the mode selector button. The tab 32 thus formed is connected to the remaining peripheral rim 20 of the button by the axial portion 34.This tab 32 constitutes the operating member 31 of the locking-unlocking device. The operating member 31 is thus able to pivot relative to the axial part 34 of the peripheral edge 22 between a locking position, in which the operating member 31 extends in line with the peripheral edge 22, as illustrated in the figures. figures 3 And 4 ; and an unlocking position in which the operating member 31 is arranged inside the mode selection button 20.

[0026] With reference to the figure 4The operating member 31 further comprises a locking finger 36 fixed to its inner face. The locking finger 36 extends substantially in the radial direction Y relative to the axis of rotation Z. The locking finger 36 has a free end face 38, a first lateral face 40, and a second lateral face 42 opposite the first lateral face, a lower face 44 directed towards the cover 14, and an upper face 46 opposite the lower face. The locking finger 36 is provided with a groove 48 extending substantially transversely to the cover. The groove 48 is open on the lower face 44 and opens onto the two lateral faces 40, 42 of the locking finger. The locking / unlocking device 30 further comprises a projection 50 carried by the support 14.The projection 50 is suitable to come against the first lateral face 42 of the locking finger to lock the rotation of the mode selection button 20 towards the third position N, when the operating member 31 is in the locking position as illustrated on the . figures 3 And 4 The first lateral face 42 has a normal vector directed in the same direction as the direction of rotation of the mode selection button 20 to go from the second position 100% to the third position N. When the operating member 31 is pivoted into the unlocked position and the user pivots the mode selection button around the rotation axis Z in the counterclockwise direction, the projection 50 engages in the groove 48 of the locking finger thus allowing the rotation of the mode selection button 20 to the third position N.

[0027] In the embodiment shown, the projection 50 is formed by a rib 52 that extends in the shape of a circular arc in the plane of the support 10. The circular arc shape is centered on the axis of rotation Z. The rib 52 is located on the same side of the locking finger 36 as the side of the first EMER position relative to the second 100% position. In the embodiment shown, the rib 52 extends over an angular sector substantially equal to the angular sector separating the second 100% position from the third N position.

[0028] In the embodiment shown, the outer face of the operating member 31 is provided with a first projecting portion 54 having an actuation zone 56 which the user presses to rotate the operating member 31 from the locked position to the unlocked position. The mode selection button 20 further has a second projecting portion 58 diametrically opposite the first projecting portion 54 with respect to the axis of rotation Z. The first projecting portion 54 and the second projecting portion 58 are intended to facilitate the recognition of the position of the selection button 20 relative to the support 10 by touch.

[0029] Advantageously, the locking / unlocking device 30 of the control assembly further includes a first stop 60 designed to prevent the pivoting of the operating member 31 when the groove 48 of the locking finger is positioned directly above the projection 50. The first stop 60 is arranged on the cover 14 directly above the free end 38 of the locking finger. The first stop 60 is located at a distance from the projection 50 substantially equal to the distance separating the groove 48 from the end face 38 of the locking finger. The first stop 60 is, for example, formed by a wall which extends perpendicularly to the support 10 in a transverse direction X. Advantageously, the first radial stop 60 facilitates the transition to the third position N because the pressure on the operating member 31 is limited and allows the mode selection knob 20 to be turned quickly towards the third position N.During operation, the mode selector knob 20 is generally positioned in the second 100% position. If the user turns the mode selector knob 20 clockwise, they select the first EMER position. In this embodiment, rotation from the second 100% position to the first EMER position can be performed with or without pressing the operating member 31. If the user turns the mode selector knob 20 counterclockwise without pressing the actuating area 56 of the operating member, the first side face 42 of the locking finger comes to rest against the projection 50. Thus, the first side face 42 of the locking finger and the projection 50 lock the rotation of the mode selector knob to the third N position.If the user wishes to select the third position N, they must press the actuation zone 56 of the operating member 31 and then turn the mode selection knob counterclockwise. This action pivots the operating member 31, and the locking finger 36 is moved in a radial direction Y until it comes to rest against the first stop 60. The groove 48 is then aligned with the projection 50. The first lateral face 42 no longer opposes the counterclockwise rotation of the mode selection knob 20. The user can then turn the mode selection knob 20 counterclockwise to select the third position N. Thus, advantageously, the locking / unlocking device 30 according to the present invention prevents accidental selection of the third mode N.The oxygen mask user must perform an additional deliberate action—namely, pressing the control button 31—to select the third operating mode of the control system. This deliberate action reduces the risk of the mode selection button being unintentionally positioned in the third position, N.

[0030] There figure 5represents a mode selection button and a cover of a first variant 61 of the control assembly according to the first embodiment of the invention. The locking / unlocking device 62 of this first variant is similar to the locking / unlocking device 30 of the control assembly according to the first embodiment of the invention, except that the cover 14 also includes a second stop 64. The other elements of the locking / unlocking device 62 according to this variant are identical to the elements of the locking / unlocking device 30 according to the first embodiment illustrated in the figures 3 And 4They bear the same references and will not be described a second time. The second stop 64 is carried by the cover 14. It is designed to stop the rotation of the mode selection knob 20 clockwise towards the first EMER position when the operating member 31 is in an unlocked position, i.e., when the operating member 31 is pushed into the housing 13.

[0031] The second stop 64 extends radially along the Y direction parallel to the locking finger 36. It is offset from the locking finger 36 along the X direction. It is positioned between the first stop 60 and the end face 38 of the locking finger when the operating member 31 is in the locked position. It is positioned offset from the locking finger 36 along the X direction. It is located opposite at least a portion of the second lateral face 40 of the locking finger when the operating member 31 is in the unlocked position. In the embodiment shown, the second stop 64 is integral with the first stop 60. It extends radially towards the operating member 31.The second lateral face 40 of the locking finger is designed to abut against the second stop 64 when the operating member 31 is in the unlocked position and the mode selection button 20 is rotated to the first EMER position. In this first variant 61, rotation from the second position 100% to the first EMER position can only occur when the user is not pressing on the actuation area 56 of the operating member.

[0032] There figure 6represents a mode selection button and a cover of a second variant 65 of the control assembly according to the first embodiment of the invention. The locking / unlocking device 66 of the assembly according to this second variant is similar to the locking / unlocking device 30 of the control assembly according to the first embodiment of the invention, except that the operating member 31 is not formed by a tab 32 formed in the peripheral rim 22 but by an independent lever 68, and that the locking / unlocking device 66 further comprises a support wall 69 fixed to the axial ring 24 of the mode selection button and a spring 71 arranged between the lever 68 and the support wall 69. The spring 71 is adapted to maintain the lever in the locked position against the rotation of the mode selection button towards the third position.The other elements of the locking-unlocking device according to this second variant are identical to the elements of the locking-unlocking device 30 according to the first mode illustrated on the . figures 3 And 4 They bear the same references and will not be described a second time.

[0033] According to this second variant, a lateral portion of the peripheral edge 22 has a through-opening 70 of substantially rectangular shape. The lever 68 is arranged within the mode selection knob. It is pivotally mounted about a pivot axis XX. The lever 68 is designed to pass through the through-opening 70. The support wall 69 extends in a plane (X, Z) parallel to the rib 52. It is fixed to the axial ring 24 by means of an intermediate arm. The support wall 69 and the spring 71 are arranged in a space located on the side of the first lateral face 40, above the locking finger 36. The spring 71 is mounted against the inner face of the lever 68. It exerts a force on a part of the free end of the lever 68. A locking finger 36 identical to the locking finger 36 of the operating member according to the first embodiment is fixed to the lever 68 and extends in the radial direction Y.The lever 68 has a first projecting portion 54 with an actuation zone 56. According to an alternative not shown, the support wall 69 and the spring 71 are arranged in a space located on the side of the second lateral face 42, below the locking finger 36. In this case, the spring 71 exerts a force on a part of the lever adjacent to the pivot axis XX.

[0034] The operation of the locking-unlocking device 66 according to the second variant is identical to the operation of the locking-unlocking device 30 according to the first embodiment and will not be described a second time.

[0035] There figure 7represents a mode selection button and a cover of a control assembly 72 according to a second embodiment of the invention. This control assembly 72 comprises a locking-unlocking device 73 having a projection 50 and an operating member 74. The projection 50 is identical to the projection 50 of the locking-unlocking device according to the first embodiment and will not be described a second time.

[0036] The operating member 74 includes a push button 75, a locking finger 36 and an elastic element 80 suitable for holding the push button in a locked position.

[0037] The push button 75 comprises a main body 76 and a head 78 integral with the main body and smaller than the main body 76. The push button 75 has a bearing surface 82 located between the main body and the head. In the embodiment shown, the main body 76 and the head 78 are cylindrical. The bearing surface 82 is annular. The head 78 is arranged in a through hole 84 formed in the peripheral rim 22 of the mode selection button 20.

[0038] The elastic element 80 is designed to hold the bearing face 82 against the inner face of the peripheral rim 22 so that the head 78 is held outside the mode selector button 20 in the mode selector button's locked position. The elastic element 80 is, for example, a compression spring. The elastic element 80 is arranged between an end face 86 of the main body and a support wall 85 integral with the mode selector button 20. In the embodiment shown, the support wall is fixed to a beam 88 connecting the peripheral rim 22 to the axial ring 24. The support wall 85 extends in a plane perpendicular to the radial direction Y. The support wall 85 extends directly opposite the end face 86 of the cylindrical body. Advantageously, in the embodiment shown, the end face 86 is provided with a nipple 89 forming a guide for a part of the elastic element.

[0039] The push axis of the push button 75 extends along the radial direction Y. Thus, the push button 75 is able to slide along the radial direction Y relative to the peripheral rim 22, when the user presses on the end face of the head 78. This end face of the head 78 forms an actuation zone 56.

[0040] The locking pin 36 is fixed integrally to the main body 76. The locking pin 36 extends along the radial axis Y. Advantageously, the locking pin is arranged, along the axis of rotation Z, between the support 14 and a portion of the push button 75. The radial movement of the push button 75 relative to the peripheral edge 22 causes the locking pin to move radially. The locking pin 36 is similar to the locking pin of the operating member 31 according to the first embodiment. In particular, the locking pin 36 has a free end face 38, a first lateral face 42, a second lateral face 40 opposite the first lateral face, and a lower face 44 directed towards the cover 14. The locking pin 36 is provided with a groove 48 extending substantially transversely to the cover.The groove 48 is open on the lower face 44 and opens onto the two lateral faces 40,42 of the unlocking finger.

[0041] The support wall 85 extends directly opposite the end face 38 of the locking finger. It serves both as a bearing surface for one end of the elastic element 80 and as a first stop 60 against which the locking finger abuts when the groove 48 is aligned with the projection 50.

[0042] At rest, the elastic element 80 holds the push button 75 in a position that locks it from rotation to the third position N as illustrated in the figure 7In this position, the first lateral face 42 of the locking finger abuts against the projection 50 and locks the rotation of the mode selector knob 20 towards the third position N. When the user presses the push button head, the push button 75 slides in the through-hole 72 and the elastic element 80 compresses until the locking finger 36 abuts against the part of the support wall 85 forming the first stop 60. Then, when the user rotates the mode selector knob 20 around the axis of rotation Z, the projection 50 passes through the groove 48 of the locking finger, thus allowing the rotation of the mode selector knob 20 towards the third position N.

Claims

1. Regulation assembly (1, 61, 65, 72) for a respirator mask (2) of an aircraft crew member, said assembly comprising: - a support (10); - a mode selection knob (20) mounted pivoting on the support (10) with respect to an axis of rotation (Z), the axis of rotation (Z) being arranged perpendicularly to said support (10); a radial direction (Y), a transverse direction (X) and the axis of rotation (Z) forming a direct trihedron; said selection knob being capable of pivoting between at least one first position (EMER), a second position (100%) and a third position (N), the second position (100%) being positioned between the first position (EMER) and the third position (N); - a regulator intended to be supplied by a respiratory gas source and adapted to supply a respiratory cavity (4) at least in the three following operating modes: a) when the mode selection knob (20) is in the first position (EMER), the regulator supplies the respiratory cavity (4) as long as the pressure in the respiratory cavity is not greater than a first relative pressure with respect to the ambient pressure, b) when the mode selection knob (20) is in the second position (100%), the regulator supplies the respiratory cavity (4) as long as the pressure in the respiratory cavity (4) is not greater than a second relative pressure with respect to the ambient pressure, the first pressure being greater than the second pressure, c) when the mode selection knob (20) is in the third position (N), the regulator supplies the respiratory cavity (4) with respiratory gas diluted with air, characterised in that it includes at least one locking-unlocking device (30, 62, 66, 73) capable of locking and / or unlocking the rotation of the mode selection knob (20); the locking-unlocking device (30, 62, 66, 73) comprising a manoeuvring member (31, 68, 74) capable of being moved between a locking position and an unlocking position; the locking position locking the rotation of the mode selection knob (20) from the second position (100%) to the third position (N), the unlocking position allowing the rotation of the mode selection knob (20) from the second position (100%) to the third position (N), and in that the manoeuvring member (31, 68, 74) includes a locking finger (36) extending along the radial direction (Y), the locking finger (36) including a substantially transverse groove (48), and wherein the locking-unlocking device (30, 62, 66, 73) further includes a protrusion (50) carried by said support (14), said protrusion (50) being able to abut against a first lateral face (42) of the locking finger to lock the rotation to the third position (N), when the manoeuvring member (31, 68, 74) is in the locking position; the protrusion (50) being suitable for passing through said groove (48) to allow the rotation of the mode selection button (20) to the third position (N), when the manoeuvring member (31, 68, 74) is in the unlocking position.

2. Regulation assembly (1, 61, 65, 72) according to claim 1, wherein the manoeuvring member (31, 68, 74) is capable of moving along the radial direction (Y), after pressing on an actuation zone (56) of the manoeuvring member, and wherein the locking-unlocking device (30, 62, 66, 73) comprises a first stop (60) capable of stopping the movement of the manoeuvring member (31, 68, 74), when the groove (48) is opposite the protrusion (50).

3. Regulation assembly (1, 61, 65, 72) according to claim 2, wherein the first stop (60) is disposed in line with an end face (38) of the locking finger at a distance from the protrusion (50) substantially equal to the distance between the groove (48) and the end face (38) of the locking finger.

4. Regulation assembly (1, 61, 65) according to either one of claims 2 and 3, wherein the first stop (60) is arranged on the support (14).

5. Regulation assembly (61) according to any one of claims 2 to 4, wherein the locking-unlocking device (62) includes a second stop (64) capable of stopping the rotation of the mode selection knob (20) from the second position (100%) to the first position (EMER), when the manoeuvring member (31) is in the unlocking position, while allowing the rotation of the mode selection knob (20) from the second position (N) to the third position (N).

6. Regulation assembly (61) according to claim 5, wherein the locking finger (36) has an end face (38) and a second lateral face (40) opposite said first lateral face (42) and wherein said second stop (64) is arranged, in the radial direction (Y), between the first stop (60) and the end face (38) of the locking finger when the manoeuvring member (31) is in the locking position, and in the transverse direction (X), with respect to at least a part of a second lateral face (40) of the locking finger, when the actuating member (31) is in the unlocking position.

7. Regulation assembly (1, 61, 65, 72) according to any one of claims 1 to 6, wherein the protrusion (50) is a rib (52) that has the shape of an arc of a circle in a plane of the support, said arc of a circle being centred on the axis of rotation (Z).

8. Regulation assembly (65) according to any one of claims 1 to 7, wherein the manoeuvring member (31, 68) includes a lever (68) mounted pivotably relative to the mode selection knob (20) about a first pivot axis (X-X), the first pivot axis being parallel to the axis of rotation (Z); and wherein the mode selection knob (20) has a bottom (21) extending perpendicular to the axis of rotation (Z) and a peripheral edge (22) including a through opening (70), and wherein at least a portion of the lever (68) extends through the through opening (70).

9. Regulation assembly (1) according to any one of claims 1 to 7, wherein the mode selection knob (20) has a bottom (21) extending perpendicularly to the axis of rotation (Z) and a peripheral edge (22), said peripheral edge being provided with a through cut out forming a tongue (32) connected to a portion of the peripheral edge by an axial portion (34); said tongue (32) being capable of pivoting with respect to a pivot axis (X-X) parallel to the axis of rotation (Z) by plastic deformation of said axial portion (34) of the peripheral edge.

10. Regulation assembly (1) according to claim 9, wherein said through cut out comprises a first cutout portion (26) that extends in a transverse direction (X), and a second cutout portion (28) that extends along the direction of the axis of rotation (Z), the second cutout portion (28) extends the first cutout portion (26) and opens out to the outside of the mode selection knob.

11. Regulation assembly (72) according to any one of claims 1, 2 and 6, wherein the mode selection button (20) has a bottom (21) extending perpendicularly to the axis of rotation (Z) and a peripheral edge (22) provided with a through hole (84), and wherein the manoeuvring member (74) comprises a push button (75) having a head (78) provided with an actuation zone (56), said head being arranged in the through hole (84), the push button (74) being capable of sliding in a radial direction (Y) with respect to the peripheral edge (22) when the user presses on said actuation zone (56).

12. Regulation assembly (72) according to claim 11, wherein the locking finger (36) is disposed between a portion of the push button (75) and the support (14) in the direction of the axis of rotation (Z); said locking finger (36) being attached to the push button (75) so that the sliding of the push button causes the locking finger (36) to move in the radial direction (Y).

13. Regulation assembly (72) according to either one of claims 11 and 12, wherein the locking-unlocking system (73) includes a support wall (85) integral with the mode selection knob, and an elastic element (80) capable of acting between the push button (75) and said support wall (85) to hold the push button (75) in a locking position.

14. Regulation assembly (72) according to the combination of claims 3 and 13, wherein the support wall (85) extends in line with an end face (86) of the push button and in line with the end face (38) of the locking finger, said support wall (85) forming the first stop (60).