Device for protecting an individual sitting on a seat, a seat, and a vehicle

Abstract

A protection device having a set of inflatable protection members including a neck airbag, a left lower airbag, a left upper airbag, a right lower airbag, and a right upper airbag. The protection device has a lower pocket provided with a lower base forming the neck airbag and two lower lateral branches forming the left lower airbag and the right lower airbag. An upper pocket at least partially secured to the lower pocket is provided with an upper base forming a head airbag and two upper lateral branches forming the left upper airbag and the right upper airbag. At least one longitudinal internal wall provide at least two “tubes” in each upper airbag, the upper pocket being in fluid flow communication with the lower pocket.

Claims

1. A protection device for protecting an individual held on a seat with the help of a harness that has a left shoulder strap and a right shoulder strap, the protection device comprising: a set of inflatable protection members including a neck airbag and left inflatable lateral means and right inflatable lateral means, the left inflatable lateral means having a left lower airbag and a left upper airbag, the right inflatable lateral means having a right lower airbag and a right upper airbag, each upper airbag overlying a lower airbag in an elevation direction; a C-shaped inflatable lower pocket provided with a lower base forming the neck airbag and two lower lateral branches respectively forming the left lower airbag and the right lower airbag for positioning on a chest of the individual, the lower base including an orifice for admitting an inflation fluid; and a C-shaped inflatable upper pocket provided with an upper base forming a head airbag and two upper lateral branches extending longitudinally and forming respectively the left upper airbag and the right upper airbag, each upper lateral branch having at least one longitudinal internal wall so as to provide at least two tubes in each upper airbag, the upper pocket being in fluid flow communication with the lower pocket, the upper pocket being secured at least in part to the lower pocket, so that each upper airbag of an inflatable lateral means is secured at least in part to the lower airbag of the inflatable lateral means; wherein the lower pocket has a lower wall and the upper pocket has an upper wall, the lower wall being secured in part to the upper wall by two joint areas per inflatable lateral means, the protection device further comprising a left path and a right path being provided respectively between the left lower airbag and the left upper airbag and between the right lower airbag and the right upper airbag in order to enable the shoulder straps to pass, the left path being defined between the two joint areas of the left inflatable lateral means and the right path being defined between the two joint areas of the right inflatable lateral means.

2. The protection device according to claim 1, wherein the upper base is in fluid flow communication with the lower base.

3. The protection device according to claim 1, wherein the upper pocket and the lower pocket have a common wall separating them in elevation.

4. The protection device according to claim 1, wherein the lower pocket has a left slot in elevation and a right slot in elevation for the shoulder straps to pass through.

5. The protection device according to claim 1, wherein the lower base includes a non-inflatable central zone and an O-shaped inflatable peripheral zone surrounding the non-inflatable zone.

6. The protection device according to claim 5, wherein the non-inflatable zone is closed by a fabric.

7. The protection device according to claim 5, wherein the protection device has a headrest secured to the lower base, and the protection device includes a C-shaped holder bar crossing the non-inflatable zone and being attached to the headrest, surrounding the peripheral zone.

8. The protection device according to claim 1, wherein the protection device includes slider means for each inflatable lateral means passing at least in part between the lower pocket and the upper pocket in order to join attachment means for attaching to the seat.

9. The protection device according to claim 1, wherein the protection device includes at least one tie secured to at least one of the upper and lower pockets, the protection device including direct or indirect attachment means for attaching the tie to the seat in order to limit forward movement of the chest of the individual in contact with the protection device.

10. The protection device according to claim 9, wherein the tie includes at least one loop closed by at least one stitching zone suitable for breaking under a predetermined traction force.

11. The protection device according to claim 1, wherein each inflatable lateral means extends longitudinally from the neck airbag and the head airbag towards a free end, each inflatable lateral means having a thickness that decreases going from the neck airbag and the head airbag towards the free end when the lateral means are inflated.

12. The protection device according to claim 1, wherein the upper airbag includes a peripheral partition having a height greater than a height of each internal wall.

13. The protection device according to claim 1, wherein the protection device includes an inflator and a distributor, the distributor being arranged at least in part in the lower base, the distributor including a projecting means for projecting fluid into the lower base along a transverse direction.

14. The protection device according to claim 1, wherein the set of inflatable protection members is folded inside an envelope having a zone of weakness to enable the inflatable protection members to be deployed, the envelope having a lower segment configured to rest on the individual, and an upper segment configured to not rest on the individual when the airbags are not inflated, the lower segment having a surface with a low coefficient of friction and the upper segment having a surface with a high coefficient of friction that is configured to come into contact with the individual when the airbags are inflated.

15. The protection device according to claim 1, wherein the set of inflatable protection members is folded inside an envelope having a zone of weakness to enable the inflatable protection members to be deployed, the zone of weakness configured to be directed towards a head of the individual so long as the airbags are not inflated.

16. A protection device for protecting an individual held on a seat with help of a harness that has a left shoulder strap and a right shoulder strap, the protection device comprising: a set of inflatable protection members including a neck airbag and left inflatable lateral means and right inflatable lateral means, the left inflatable lateral means having a left lower airbag and a left upper airbag, the right inflatable lateral means having a right lower airbag and a right upper airbag, each upper airbag overlying a lower airbag in an elevation direction; a C-shaped inflatable lower pocket provided with a lower base forming the neck airbag and two lower lateral branches respectively forming the left lower airbag and the right lower airbag for positioning on a chest of an individual, the lower base including an orifice for admitting an inflation fluid; a C-shaped inflatable upper pocket provided with an upper base forming a head airbag and two upper lateral branches extending longitudinally and forming respectively the left upper airbag and the right upper airbag, each upper lateral branch having at least one longitudinal internal wall so as to provide at least two tubes in each upper airbag, the upper pocket being in fluid flow communication with the lower pocket, the upper pocket being secured at least in part to the lower pocket, so that each upper airbag of an inflatable lateral means is secured at least in part to the lower airbag of the inflatable lateral means; and a C-shaped inflatable head collar attached to the upper pocket and configured to surround a head of the individual without obstructing vision of the individual, the head collar being in fluid flow communication with the upper pocket.

17. A protection device for protecting an individual held on a seat with the help of a harness that has a left shoulder strap and a right shoulder strap, the protection device comprising: a set of inflatable protection members including a neck airbag and left inflatable lateral means and right inflatable lateral means, the left inflatable lateral means having a left lower airbag and a left upper airbag, the right inflatable lateral means having a right lower airbag and a right upper airbag, each upper airbag overlying a lower airbag in an elevation direction; a C-shaped inflatable lower pocket provided with a lower base forming the neck airbag and two lower lateral branches respectively forming the left lower airbag and the right lower airbag for positioning on a chest of an individual, the lower base including an orifice for admitting an inflation fluid; a C-shaped inflatable upper pocket provided with an upper base forming a head airbag and two upper lateral branches extending longitudinally and forming respectively the left upper airbag and the right upper airbag, each upper lateral branch having at least one longitudinal internal wall so as to provide at least two tubes in each upper airbag, the upper pocket being in fluid flow communication with the lower pocket, the upper pocket being secured at least in part to the lower pocket, so that each upper airbag of an inflatable lateral means is secured at least in part to the lower airbag of the inflatable lateral means; and an inflatable head collar for a head of the individual, the head collar including a fluid pressure release valve.

18. The protection device according to claim 17 wherein: the inflatable upper pocket has an inflatable upper space defined by a first layer, a second layer, and a first partition in elevation between the first and second layers for each upper lateral branch, each first partition being attached to the first layer and to the second layer, the first layer being above the second layer, each upper lateral branch having the longitudinal internal walls each attached to the first layer and to the second layer; and the inflatable lower pocket has an inflatable lower space defined by a third layer, a fourth layer, and a second partition in elevation between the third and fourth layers for each lower lateral branch, each second partition being attached to the third layer and to the fourth layer, the third layer being above the fourth layer and being attached at least in part to the second layer.

19. The protection device according to claim 18, wherein at least one of the layers includes flanks forming a partition in elevation between layers.

20. The protection device according to claim 17 wherein at least one lower or upper pocket includes two transverse projections from its lateral arms in order to optimize the distribution of fluid during inflation.

21. An aircraft, wherein the aircraft includes the protection device according to claim 17.

22. The protection device according to claim 17 wherein the head collar is C-shaped and is attached to the upper pocket, and wherein the head collar is configured to surround the head of the individual without obstructing vision of the individual, the head collar being in fluid flow communication with the upper pocket.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The invention and its advantages appear in greater detail in the context of the following description of examples given by way of illustration and with reference to the accompanying figures, in which:

(2) FIG. 1 is a diagram of a harness provided with a protection device of the invention;

(3) FIG. 2 is an exploded view of a protection device provided with a lower pocket and an upper pocket;

(4) FIG. 3 is a diagram showing slide means;

(5) FIGS. 4 and 5 are diagrams showing a holder bar;

(6) FIG. 6 is a diagram showing a lower pocket and an upper pocket when inflated;

(7) FIGS. 7 and 8 are two diagrams showing the ties connected to the inflated lower and upper pockets;

(8) FIG. 9 shows a tie provided with a loop;

(9) FIG. 10 comprises diagrams showing the operation of a tie provided with a loop depending on the morphology of an individual;

(10) FIG. 11 is a diagram showing a protection device of variable thickness;

(11) FIGS. 12 and 13 are diagrams showing an envelope of the protection device;

(12) FIG. 14 is an exploded view of a set of inflatable members;

(13) FIGS. 15 to 18 are diagrams showing the layers of said set of inflatable members;

(14) FIG. 19, a diagram showing a lower pocket including two transverse extensions;

(15) FIGS. 20 and 21 are diagrams showing a layer of a pocket provided with flanks representing a partition;

(16) FIG. 22, a diagram showing a zone of weakness 103 of an envelope, and

(17) FIG. 23, a diagram showing an upper airbag provided with one internal wall.

DETAILED DESCRIPTION OF THE INVENTION

(18) Elements shown in more than one of the figures keep the same references in each of them.

(19) FIG. 1 shows a seat 2 having a backrest 3 and a seat pan 4 for supporting an individual. The seat is provided with a harness 5 having a protection device 10 of the invention.

(20) The harness 5 has a left shoulder strap 6 and a right shoulder strap 7 suitable for resting on the shoulders of an individual (not shown). The left shoulder strap 6 and the right shoulder strap 7 may be attached to the seat by retractors (not shown on FIG. 1) passing through attachment means 87 of the rotary connection type. For example, these attachment means 87 are attached to a headrest 85 of the protection device 10. Optionally, the headrest 85 may be movable in elevation to adapt to the morphology of the individual sitting on the seat.

(21) Furthermore, the protection device 10 has a set of inflatable members folded in a breakable envelope 100. This set of inflatable members comprises in particular left inflatable lateral means arranged in the envelope 100 on the left shoulder strap 6, right inflatable lateral means arranged in the envelope 100 on the right shoulder strap 7, and a neck airbag arranged in the envelope 100 and attached to the headrest 85.

(22) FIG. 2 is an exploded view of a protection device 10.

(23) The set 15 of inflatable members includes an inflatable lower pocket 40. This lower pocket 40 is C-shaped, being provided with a lower base 41 forming the neck airbag 21 that is connected to the headrest 85.

(24) Furthermore, the lower pocket 40 extends longitudinally from the lower base along two lower lateral branches 42, 43 forming respectively a left lower airbag 22 of the left inflatable lateral means 16 and a right lower airbag 23 of the right inflatable lateral means 17.

(25) The lower base 41 is provided with an orifice 44 for engaging around a fluid distributor 125. The distributor 125 is carried by the headrest 85 and may co-operate with an inflator 120 for inflating the lower pocket.

(26) Once inflated, the C-shape of the lower pocket 40 is almost closed, while nevertheless leaving an oblong opening through which the neck of an individual passes.

(27) The set 15 of inflatable members also has a C-shaped inflatable upper pocket 50 provided with an upper base 51 forming a head airbag 31. The upper pocket extends longitudinally from the upper base along two upper lateral branches 52, 53 respectively forming a left upper airbag 32 of the left inflatable lateral means 16 and a right upper airbag 33 of the right inflatable lateral means 17.

(28) In addition, each upper lateral branch 52, 53 has at least one longitudinal internal partition 54 referred to as “internal walls”. Each internal wall serves to organize two adjacent “tubes” 55 in each upper airbag 32, 33.

(29) According to the FIG. 23, one internal wall serves to organize two adjacent “tubes” 55 in each upper airbag 32, 33

(30) According to the embodiment of the FIG. 1, each upper lateral branch 52, 53 has two longitudinal internal walls 54 to organize three adjacent “tubes” 55 in each upper airbag 32, 33.

(31) Whatever the embodiment, the tubes of an upper lateral branch are in fluid flow communication with one another via the upper base and/or a free end of the upper lateral branch.

(32) The upper pocket 50 is in fluid flow communication with the lower pocket 40, e.g. via a lower passage 130 of the lower base 41 communication with an upper passage (not shown on the FIG. 2) of the upper base 51.

(33) Furthermore, the upper pocket 50 is secured at least in part to the lower pocket 40.

(34) The upper pocket 50 and the lower pocket 40 may optionally have a common wall separating them in elevation.

(35) In the example of FIG. 2, the upper pocket 50 and the lower pocket 40 are attached to each other by stitching or the equivalent to form a common wall.

(36) Under such circumstances, the lower pocket 40 has a lower wall 46 that is secured in part to an upper wall 56 of the upper pocket 50.

(37) So, each upper airbag of an inflatable lateral means is secured at least in part to the lower airbag of said inflatable lateral means by at least one joint area 500. The FIG. 2 shows two joint areas 500 per inflatable lateral means. The protection device of this figure further comprises a left path 65 and a right path 66 being provided respectively between the left lower airbag 22 and the left upper airbag 32 and between the right lower airbag 23 and the right upper airbag 33 in order to enable said shoulder straps 6, 7 to pass. The left path 65 is defined between the two joint areas 500 of the left inflatable lateral means 16 and the right path 66 is defined between the two joint areas 500 of the right inflatable lateral means 17.

(38) Furthermore, each shoulder strap runs along a corresponding inflatable lateral means between the lower airbag and the upper airbag of the inflatable lateral means.

(39) Consequently, the protection device 10 has a left path 65 formed between the left lower airbag 22 and the left upper airbag 32, and a right path 66 arranged between the right lower airbag 23 and the right upper airbag 33 in order to said shoulder straps 6 and 7.

(40) The lower pocket is then provided with a left slot 47 and a right slot 48 for enabling the left and right shoulder straps 6 and 7 to pass through the thickness of the pocket.

(41) A shoulder strap thus passes between an upper airbag and a lower airbag, and then passes through the thickness of the lower pocket in order to pass under the neck airbag and reach a refractor, via a rotary connection 87, if any.

(42) Each rotary connection 87 enables a shoulder strap to rotate relative to the seat. A rotary connection may comprise a circular stationary support and a circular movable support capable of performing rotary movement relative to each other. For example ball or roller bearing means may be interposed between the two supports. Each support then has a slot through which a shoulder strap passes.

(43) In an alternative configuration, the connection 87 may be spherical connection allowing rotations in more than one direction.

(44) In order to avoid friction between inflatable lateral means and a shoulder strap, the protection device 10 may include slider means for each inflatable lateral means 16, 17. The slider means are interposed between a shoulder strap and the corresponding inflatable lateral means. For example, slider means may extend between the lower pocket 40 and the upper pocket 50 so as to extend as far as a rotary connection 87 of a seat 2.

(45) The slider means and/or the associated rotary connection may include a breakable section for separating the slider means from the seat. For example, two supports of a rotary connection may be separated from each other above a predetermined force threshold.

(46) With reference to FIG. 3, the slider means may comprise a base 91 carrying a plurality of guides 92 having a shoulder strap passing therethrough. Each guide may be of flattened O-shape, for example.

(47) With reference to FIG. 2, the set 15 of inflatable members may include a C-shaped inflatable head collar 60. This head collar 60 is attached to the upper pocket so as to surround an individual's head without obstructing vision, the head collar 60 being in fluid flow communication with the upper pocket 50. For example, the upper pocket 50 has at least one passage 132 communicating with a passage of the head collar (not visible in FIG. 2).

(48) The head collar 60 may also include a fluid pressure release valve 61.

(49) Under such circumstances, and as a result of a crash, the inflator 120 injects fluid into the distributor 125. This fluid spreads within the lower pocket 40 via the lower base 41 and then reaches the upper pocket 50 and the head collar 60, if any.

(50) In order to avoid an impact between the injected fluid and an individual's head, the distributor 125 may comprise a projection means 126 for projecting fluid into the lower pocket 20 in a transverse direction. Such projection means can include a casing provided with some output apertures directed along said transverse direction.

(51) Furthermore, the lower base 41 may have a non-inflatable central zone 80 and an inflatable peripheral zone 81 of O-shape surrounding the non-inflatable zone 80 in order to channel the injected fluid.

(52) The non-inflatable zone 80 may optionally be shut off by fabric 82.

(53) In addition, and with reference to FIGS. 4 and 5, the protection device 10 may also include a C-shaped holder bar 86 that passes through the non-inflatable zone 80 to be attached to the headrest 85 by surrounding the peripheral zone 81.

(54) This holder bar seeks to avoid the neck airbag tearing during inflation.

(55) FIG. 6 shows a protection device 10 with the set of inflatable members being inflated.

(56) The head and the chest of the individual 1 are then held by the inflatable lateral means 16, 17. The internal walls 54 tend to avoid the lower airbag deforming as a result of the upper airbag being flattened during any lateral movement of the chest by stiffening the upper airbag.

(57) Furthermore, each upper airbag 32, 33 may have a peripheral partition 74 of a first height H1 that is greater than a second height H2 of the internal walls 54.

(58) With reference to FIG. 7, inertia forces F may cause the chest of an individual 1 to move forwards.

(59) As a result of this movement, a breakable section, and in particular a breakable section of a rotary connection 87, may break so as to allow the airbags to move with the chest. Thus, each lower airbag can remain in contact with the chest of the individual 1.

(60) Nevertheless, the protection device may include at least one tie 95 for limiting this forward movement.

(61) In FIG. 7, one tie 95 extends between the lower pocket 40 and the seat while another tie 95 extends between the upper pocket 50 and the headrest 85. A tie 95 may optionally extend between the upper pocket 50 and the headrest 85 while being attached in part by means of stitching to slider means.

(62) More precisely, a tie 95 is secured to the layer of the lower pocket that is closest to the chest of the individual 1.

(63) In FIG. 8, a tie 95 extends between a lower pocket or an upper pocket and slide means, a cable 95′ extending between the slide means and the seat 2.

(64) With reference to FIG. 9, each tie may be of variable length. Thus, a tie 95 may include a loop 98 and at least one stitching zone 99 dimensioned so as to break as from a force threshold in order to lengthen the tie 95.

(65) For example, the tie comprises two stitching zones, one zone to adapt the length of the tie in function of the morphology of an individual, and another zone to adapt the length of the tie in function of the sustained dynamic forces to limit a possible submarining

(66) With reference to FIG. 11, the initial position of the inflatable means on an individual depends on that individual's morphology.

(67) Under such circumstances, after a crash and after the individual has moved forwards, the length of the tie depends on that individual's morphology and on the sustained forces. This characteristic tends to encourage keeping the inflatable lateral means against the individual's chest.

(68) With reference to FIG. 12, each inflatable lateral means 16, 17 extends longitudinally from the neck airbag 21 and the head airbag 31 towards a free end 110. Each inflatable lateral means 16, 17 may then have a thickness EP that decreases from a maximum thickness EP1 close to the neck airbag 21 and the head airbag 31 towards a minimum thickness EP2 close to the free end 110 when the lateral means are inflated.

(69) With reference to FIG. 12, the lower and upper pockets are folded in normal conditions.

(70) These lower and upper pockets are then arranged in an envelope 100 that is suitable for opening when they inflate. The envelope 100 may comprise two lateral sections surrounding the lateral branches of the lower and upper pockets and a root portion surrounding the bases of the lower and upper pockets.

(71) This envelope includes a zone of weakness 103, e.g. provided with loop-and-hook closure means.

(72) This zone of weakness 103 is in register with an individual's head so as to limit any risk of impact between the envelope and the individual's head during inflation. The FIG. 22 shows in dotted line the envelope 100, and in continuous line the zone of weakness 103 of said envelope according to an embodiment.

(73) With reference to FIG. 12, the envelope may also have a lower segment 101 resting against an individual and an upper segment 102 that does not rest against the individual when the airbags are not inflated. The lower segment 101 has a surface with a low coefficient of friction, while the upper segment 102 has a surface with a high coefficient of friction that comes into contact with an individual when the airbags are inflated.

(74) On the airbags being inflated, the zone of weakness is broken. The airbags then exert pressure on the upper segment 12 causing it to turn as shown by arrows F1.

(75) With reference to FIG. 13, each upper segment 102 then becomes blocked between the individual 1 and a lower airbag.

(76) FIG. 14 is an exploded view of a set of inflatable members.

(77) The inflatable upper pocket 50 has an inflatable upper space 50′ defined in elevation by a first layer 71 above a second layer 72. In addition, this upper space 50′ is defined laterally by a first partition 75 in elevation between the layers arranged in each upper lateral branch 52, 53.

(78) Under such circumstances, and with reference to FIG. 15, the first layer 71 may have a peripheral line of stitching 71′ and two internal lines of stitching 71″ per lateral branch.

(79) Likewise, and with reference to FIG. 16, the second layer 72 may have a peripheral line of stitching 72′ and two internal lines of stitching 72″ per lateral branch.

(80) An operator can then attach the internal walls 54 by sewing them to the internal lines of stitches 71″ and 72″ of the first and second layers 71 and 72.

(81) The operator may also attach the first layer 71 to the second layer 72 by sewing the peripheral line of stitching 71′ of the first layer 71 to the peripheral line of stitching 72′ of the second layer 72 directly and/or via a first partition 75.

(82) Furthermore, the second layer may include internal zones of stitching 72′″ for sewing to the lower pocket to define the paths for a shoulder strap and its slider means, and the joint areas 500 between the lower and upper pockets.

(83) Finally, the second layer has an upper passage 131 for passing fluid coming from the lower pocket. The upper passage 131 may be surrounded by a zone of sealing stitching 72″. In general manner, the stitching opening on the exterior of the device are sealed.

(84) With reference to FIG. 14, the inflatable lower pocket 40 has an inflatable lower space 40′ defined by a third layer 73 above a fourth layer 74. In addition, this lower space 40′ is defined on its sides by a second partition 76 in elevation between the layers arranged in each lower lateral branch 42, 43.

(85) Under such circumstances, and with reference to FIG. 17, the third layer 73 may include a peripheral line of stitching 73′.

(86) Furthermore, the third layer 73 may have internal zones of stitching 73″ for stitching to the upper pocket and defining paths for a shoulder strap and its slider means, and the joint areas 500 between the lower and upper pockets.

(87) In addition, the third layer 73 has a lower passage 130 for passing fluid coming from the lower pocket. This lower passage 130 may be surrounded by a sealing zone of stitching 73′″.

(88) An operator can then attach the third layer 73 to the second layer 72 by sewing together their sealing zones of stitching 73′″ and 72′″ and their internal zones of stitching 73″ and 72″.

(89) Furthermore, the third layer 73 has an opening 47, 48 for each shoulder strap. Each opening is surrounded by a line of sealing stitching 47′, 48′.

(90) Finally, the third layer 73 may define a non-inflatable zone 80 of the lower base of the lower pocket by means of a sealing line of stitching 80′. This non-inflatable zone may comprise a fabric of the third layer or it may be open.

(91) Likewise and with reference to FIG. 18, the fourth layer 74 may have a peripheral line of stitching 74′ and two openings 47, 48 for each shoulder strap. Each opening is surrounded by a sealing line of stitching 47″, 48″.

(92) The fourth layer 74 may also define a non-inflatable zone 80 of the lower base of the lower pocket using a sealing line of stitching 80″. This non-inflatable zone 80 may comprise fabric 82. If it does, an opening 88 may be provided for passing a holder bar.

(93) With reference to FIG. 19, at least one lower or upper pocket may include two transverse extensions 78 from its lateral arms in order to optimize the distribution of fluid during inflation.

(94) These projections serve to optimize the flow section 200 for fluid between the base and the lateral branches of the pocket.

(95) Thus, the third layer 73 and the fourth layer 74 may have such projections.

(96) With reference to FIGS. 20 and 21, at least one of said layers 71, 72, 73, and 74 has flanks 77 forming a partition 75, 76 in elevation between layers.

(97) For example, the fourth layer has such flanks 77 for embodying the second partitions.

(98) As a result, the layer provided with such flanks may be obtained from two fabrics 300, 400 that are sewn together by a zone of stitching. This zone of stitching may be flared to enable the two fabrics to be moved together along arrow F2 in order to finalize the layer of FIG. 21.

(99) For example, an operator realizes successively the following step: sew the lines of sealing stitching 47′, 48′ of the third layer 73 to the lines of sealing stitching 47″, 48″ of the fourth layer 77 to form the opening 47, 48, sew the outline of the internal zones of stitching 72′″ of the second layer to the outline of the internal zones of stitching 73″ of the third layer 73, and sew the internal zones of stitching 72′″ of the second layer to the internal zones of stitching 73″ of the third layer to form the joint areas 500, sew the sealing zones of stitching 72″″ of the second 72 to the sealing zones of stitching 73′″ of the third layer to form a passage for passing fluid coming from the lower pocket to the upper pocket, sew the internal walls 54 to the second layer 72, sew the internal walls 54 to the first layer 71, sew the flanks 77 and if necessary the first layer to the second layer, and the third layer to the fourth layer.

(100) Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described above, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.