Patent Publication Number: US-2022234797-A1

Title: Assembly for closing a tube and tube comprising this assembly

Description:
The present invention relates to an assembly for closing a tube and tube comprising this assembly. 
     Tubes are known which are provided with a lid and associated with a perforating cap comprising a punch adapted to perforate said lid. 
     The lid allows the product contained in the tube to be kept hermetically sealed during its storage prior to its first use, which represents a very important part of the overall service life of the tube. 
     There are caps in which the punch is arranged in the cap and protrudes from it so that it can perforate the lid when the cap is screwed onto the tube head. In order to ensure the preservation of the lid prior to the first use, a ring is placed between the cap and a shoulder of the tube head, so as to keep the punch away from the lid when the cap is screwed on the neck. In this position, the cap is in position referred to as transport position or waiting position before the first use. 
     To pierce and/or cut the lid, the user must first unscrew the cap, then remove the ring and finally screw the cap back on until the lid is pierced and/or cut once it has reached an end of stroke position, also called closing position. The number of steps is restrictive for the user who often does not understand what the ring is for and does not necessarily understand that a lid must be pierced before the tube is used for the first time. 
     It is known from the document LU 88845 that a cap is provided with a punch which is held in waiting position without a removable ring. The neck comprises a housing in which a thread portion, located on the cap, can be blocked in such a position. The thread portion is then used to screw the cap onto the neck to a position that allows the lid to be pierced and cut off when the tube is first used. The cap can then be screwed or unscrewed for later use or left in place when equipped with a re-sealable service cap dispensing system. However, there are various disadvantages to this device. 
     First of all, the cap is positioned on the neck in waiting position using methods that operate at a very high rate. It is therefore necessary that this operation can be done with high reliability in order to provide satisfactory repeatability. 
     With the device of the document LU 88845, a rib serving to snap-fit the thread portion into the housing allowing it to be held in waiting position is carried out by radial deformation of the cap. The manufacturing tolerances remain relatively high, typically greater than a tenth of a millimeter, in such a direction, which is detrimental to an ability to obtain the desired blocking effect on all the caps produced, particularly in the case of demolding with sliders. To overcome this first disadvantage, the present invention proposes, according to a first aspect, an assembly for closing a tube, said assembly comprising a tube head that has a neck, and a cap, said assembly defining a guide path, a threading and a thread portion allowing the cap to be positioned on the neck by cooperation with the guide path and the threading, said assembly comprising a first and a second stops for said thread portion, said stops being angularly spaced apart and defining a passage between the guide path and the threading, said assembly being configured to allow axial displacement of the thread portion through the passage with a non-return effect produced by at least one of said stops. 
     According to this first aspect of the invention, the stops allowing the cap to be positioned at the desired location while preventing its return to the previous configuration, in particular a configuration in which the cap can be disconnected from the neck, are angularly positioned with respect to each other. In this way, the span of the corresponding passage can be controlled more precisely, particularly in the case of a cap and a neck demolded with sliders. This provides a manufacturing method with improved repeatability. 
     According to this first aspect, the invention may also comprise any of the following characteristics, taken individually or in any technically possible combination forming as many embodiments of the invention, this comprising with the characteristics of the other aspects of the invention set forth below:
         said tube head is further provided with a lid closing said neck,   said cap is provided with a punch adapted to perforate said lid,   said neck and said cap are configured to guide the cap from an initial position in which the cap is not engaged with the neck to a waiting position in which the punch is held at a distance from said lid, in particular after the thread portion has passed through said passage, and then from said waiting position to a closing position in which said punch has perforated said lid,   said guide path allows the passage from the initial position to the waiting position and said threading allows the passage from the waiting position to the closing position,   one of the two between the guide path and the threading induces a screwing in a clockwise direction of rotation of the cap, the other of the two between the guide path and the threading inducing a screwing in a counterclockwise direction of rotation of the cap,   the guide path induces a counterclockwise rotation of the cap and the threading induces a clockwise rotation of the cap,   the neck comprises the guide path and the threading and the cap comprises the thread portion,   the first stop forms one end of said guide path,   said assembly comprises a shoulder connecting an origin of a first thread of the threading and the first stop,   the second stop is formed by an axial partition,   the second stop forms the origin of a second thread of the threading,   said assembly comprises a third stop configured to block a screwing of the cap after positioning the cap on the neck,   said third stop comprises a wall, extending transversely from a bottom partition of the threading,   said wall extends axially partially through said threading,   an angular extension between the second and the third stop is just greater than an angular extension of the thread portion.       

     Another disadvantage of the device of the document LU 88845 is the torque required to successfully close the cap on the first use. In fact, with the cap used in this document, it is necessary to simultaneously pierce the lid and compress a seal ensuring a tight closure of the cap. Such a torque may cause discomfort to the user. 
     To overcome this other disadvantage, the present invention proposes, according to a second aspect, an assembly for closing a tube, said assembly comprising a tube head that has a neck and a lid closing said neck, said assembly further comprising a cap provided with a punch adapted to perforate said lid, said neck and said cap being configured so as to guide the cap over the neck to a closing position in which the cap has perforated the lid, by passing through an intermediate position in which the punch has finished piercing said lid, as well as to cause a deformation of the material sealing the closure, said assembly being configured so that the passage through the intermediate position takes place prior to the deformation of the material sealing the closure. 
     Material deformation means, for example, a material crushing or the like which causes a seal. 
     According to this second aspect of the invention, by sequencing the operations corresponding on the one hand to the piercing and on the other hand to the compression of the material allowing to make the closure tight, a configuration is obtained in which the torque to be exerted is more constant throughout the positioning of the cap on the neck, which is more comfortable for the user. The deformation of the sealing material only takes place once the piercing of the lid has been completed. In other words, during the deformation used for sealing, a cut in the lid can take place at the same time, but its piercing took place beforehand. In particular in the case of a punch provided with a plurality of teeth, all the teeth have pierced said lid. 
     According to this second aspect, the invention may also comprise any of the following characteristics, taken individually or in any technically possible combination forming as many embodiments of the invention, this comprising with the characteristics of the other aspects of the invention set forth herein or thereafter:
         the cap is screwed onto the neck during the passage through the intermediate position and up to the closing position,   said neck and said cap are configured to guide the cap from an initial position in which the cap is not engaged with the neck to a waiting position in which the punch is held away from the lid, and then from said waiting position to said closing position, in particular by screwing,   said cap and said neck are configured so that said intermediate position is located downstream of the waiting position along the direction of guiding the cap to the closing position,   said assembly comprises a thread portion and a threading for screwing the cap onto the neck,   said assembly comprises a stop configured to block the screwing of the cap in said waiting position, said assembly being configured so that said thread portion has passed said stop before the piercing of the lid begins,   said assembly further comprising a non-return stop configured to prevent the cap from moving out of the closing position, said assembly being configured so that said stop is passed after passing into an intermediate position,   the punch comprises a plurality of teeth, said intermediate position being the position occupied by the punch when all the teeth have pierced said lid,   said punch comprises a base having an outer cylindrical portion and said neck comprises an inner cylindrical portion,   said inner and outer cylindrical portions are intended to be crushed against each other to achieve the sealing of said closure,   said cap comprises a top from which said base of the punch extends, said punch comprising an external chamfer extending from said base and connected to a distal part of the punch,   said portion of the neck against which the base of the punch is intended to be crushed is located in the axial extension of a chamfer, located at an opening end of the neck,   said distal part of the punch has an outer diameter smaller than an inner diameter of the neck.       

     According to another disadvantage of the device of the document LU 88845, the cap comprises a non-return stop allowing the cap to be held in place once in the closing position. However, this stop is located in the threading used to guide the cap on the neck and the thread portion used to screw the cap must pass over this stop with force. This may damage said stop and requires an additional torque to be applied by the user. This stop can also give the user the impression of a hard point corresponding to an end of stroke marking the closing of the cap when this is not yet the case. The perforation of the lid by the punch may not be completed, which will hinder the proper flow of the product contained in the tube. There is also a risk that the seal may not be completely tight. 
     To overcome this other disadvantage, the present invention proposes, according to a third aspect, an assembly for closing a tube, said assembly comprising a tube head that has a neck and a lid closing said neck, said assembly further comprising a cap provided with a punch adapted to perforate said lid, said neck and said cap being configured to guide the cap to a closing position in which said punch has perforated said lid, said cap comprising a lateral skirt provided with at least one notch opening radially, said neck comprising a protrusion configured to cooperate angularly with said notch to block the withdrawal of the cap, once said cap is in said closing position. 
     According to this third aspect of the invention, the protrusion allowing to block the cap in the closing position does not come into contact with the shapes used to guide the cap to its closing position. Instead, it is located at a distance and cooperates with a specific shape, namely the notch provided in the cap to operate the desired blocking. This prevents damage to the shapes used to guide the cap on the neck and ensures that the correct end stroke position is identified. 
     According to this third aspect, the invention may also comprise any of the following characteristics, taken individually or in any technically possible combination forming as many embodiments of the invention, this comprising with the characteristics of the other aspects of the invention set forth herein or thereafter:
         said notch is open at a free edge of said skirt so as to impart radial resilience to the cap in the vicinity of said notch,   said protrusion is configured to radially spread said skirt before the cap arrives in the closing position,   said protrusion has an edge provided with an inclined portion and a straight portion, said inclined portion being configured to radially spread said cap and said straight portion being located at the level of a part of the protrusion forming a non-return stop for the cap once in closing position,   said assembly comprises a threading and a thread portion configured to cooperate with said threading for screwing the cap to said closing position,   said assembly is configured so that said thread portion reaches said closing position by passing away from said protrusion,   said protrusion extends axially from a terminal end of a lower thread of the threading,   said assembly further comprises an end of stroke stop for the cap in the closing position,   the end of stroke stop is configured to cooperate with said thread portion, once said protrusion is engaged in one of said notches,   said assembly comprises a plurality of said notches and a plurality of said thread portions, each of said thread portions being angularly located between two adjacent ones of said notches,   said cap comprises a service cap.       

     According to another disadvantage of the device of the document LU 88845, the punch projects into the interior of the receptacle in closing position of the cap. This limits the restitution rate of the product. Indeed, the product in the receptacle at the level of the punch is blocked by the latter and cannot penetrate into the neck. 
     To overcome this other disadvantage, the present invention proposes, according to a fourth aspect of the invention, an assembly for closing a tube, said assembly comprising a tube head that has a neck and a lid closing said neck, said assembly further comprising a cap provided with a punch adapted to perforate said lid, said neck and said cap being configured to guide the cap to a closing position in which said punch has perforated said lid, said punch comprising one or more teeth for cutting the lid extending from a free edge of the punch, at least one angular portion of said free edge, referred to as passage portion, being configured to remain in the neck in said closing position. 
     According to this fourth aspect of the invention, an angular portion of the punch does not penetrate into the tube and therefore nothing opposes the flow of the product which can thus be more completely distributed. 
     According to this fourth aspect, the invention may also comprise any of the following characteristics, taken individually or in any technically possible combination forming as many embodiments of the invention, this comprising with the characteristics of the other aspects of the invention set forth herein or thereafter:
         said passage portion of the free edge of the punch is flush with a lower end of the neck,   said teeth are distributed over an angular portion of the punch, referred to as cutting portion, delimited by two of said teeth located angularly on either side of said cutting portion, said passage edge being formed by an angular portion of the punch complementary to said cutting portion,   said teeth have tops that are axially offset from each other,   the axial offset of the tops of the teeth is increasing in a direction of displacement of the cap towards said closing position,   said teeth have a substantially identical height and extend axially from an angular portion of the free edge having an axial offset from one tooth to the other,   said teeth have a substantially identical profile,   said lid is located in the lower part of the neck,   said cap is screwed onto said neck over at least a part of its stroke,   said cap comprises a service cap.       

     It should also be noted that, according to another aspect, the invention concerns an assembly for closing a tube, said assembly comprising a tube head provided with a neck and a lid closing said neck, said assembly further comprising a cap provided with a punch adapted to perforate said lid, said neck and said cap being configured to guide the cap to a closing position in which said punch has perforated said lid, said punch comprising a plurality of teeth for cutting the lid extending from a free edge of the punch, said teeth having tops axially offset from each other, said teeth having a substantially identical height and extending axially from an angular portion of the free edge having an axial offset from one tooth to the other. 
     According to this aspect of the invention, an axial offset of the top of the teeth is achieved without having to use smaller and therefore more fragile teeth than others. 
     The invention also relates to a tube comprising a closure assembly as described above. 
    
    
     
       Further characteristics, purposes and advantages of the invention will be apparent from the following description, which is purely illustrative and non-limiting, and which should be read in conjunction with the appended drawings, in which: 
         FIG. 1  is a perspective view of a tube head for an assembly for the tube closing according to a first embodiment of the invention, from a first viewing angle, 
         FIG. 2  is a perspective view of the tube head of  FIG. 1  from another viewing angle, 
         FIG. 3  is a side view of the tube head of  FIG. 1  from the first viewing angle, 
         FIG. 4  is a side view of the tube head of  FIG. 1  from the other viewing angle, 
         FIG. 5  is a side view of an assembly according to the invention comprising the head of  FIG. 1  and a cap illustrated in transparency, according to the first viewing angle, in a first position of the cap, 
         FIG. 6  is a side view of the assembly of  FIG. 5  from the other viewing angle, in the first position of the cap, 
         FIG. 7  is a side view of the assembly according to  FIG. 5 , from the first viewing angle, in a second position of the cap, 
         FIG. 8  is a side view of the assembly according to  FIG. 5 , from the other viewing angle, in the second position of the cap, 
         FIG. 9  is a side view of the assembly according to  FIG. 5 , from the first viewing angle, in a third position of the cap, 
         FIG. 10  is a side view of the assembly according to  FIG. 5 , from the other viewing angle, in the third position of the cap, 
         FIG. 11  is a side view of the assembly according to  FIG. 5 , from the first viewing angle, in a fourth position of the cap, 
         FIG. 12  is a side view of the assembly according to  FIG. 5 , from the other viewing angle, in the fourth position of the cap, 
         FIG. 13  is a side view of the assembly according to  FIG. 5 , from the first viewing angle, in a fifth position of the cap, 
         FIG. 14  is a side view of the assembly according to  FIG. 5 , from the other viewing angle, in the fifth position of the cap, 
         FIG. 15  is a side view of the assembly according to  FIG. 5 , from the first viewing angle, in a sixth position of the cap, 
         FIG. 16  is a side view of the assembly according to  FIG. 5 , from the other viewing angle, in the sixth position of the cap, 
         FIG. 17  is a diametrical cross-sectional view of the assembly according to  FIG. 5  in the fourth position of the cap, 
         FIG. 18  is a diametrical cross-sectional view of the assembly according to  FIG. 5  in the fifth position of the cap, 
         FIG. 19  is a diametrical cross-sectional view of the assembly according to  FIG. 5  in the fifth position of the cap, 
         FIG. 20  is a perspective view of a distal edge of a punch of the cap of the assembly of  FIG. 5 , the orientation of the cap having been reversed from the previous figures. 
     
    
    
     As illustrated in  FIGS. 1 to 19 , the invention relates to an assembly for closing a tube, in particular a flexible tube. 
     Said assembly comprises a tube head  3  and a cap  30 . The tube head  3  comprises a neck  10  and a lid  5  closing said neck  10 , here in the lower part of the latter. In other words, the lid is disposed at the end of the neck in fluid communication with the reservoir of the tube. The cap  30  comprises a punch  7  adapted to perforate said lid  5 . Said punch  7  is in particular configured to pierce and then cut said lid  5 . Advantageously, said lid is only partially cut so that it remains attached to the tube head  3  by a portion of material. 
     The neck  10  and the cap  30  extend substantially along a longitudinal axis A (see  FIG. 17 ) passing through their center. In the following, “axial” is understood to mean oriented parallel to said longitudinal axis A. The cap  30  is movable in rotation and/or in translation with respect to said neck  10  along said longitudinal axis A. 
     Said neck  10  and said cap  30  are configured to allow the cap  30  to be guided, in particular, from an initial position, illustrated in  FIGS. 5 and 6 , to a waiting position, illustrated in  FIGS. 9 and 10 , and then from said waiting position to a closing position, illustrated in  FIGS. 15 and 16 . 
     When the cap  30  is in its initial position, said cap  30  is not in engagement with the neck  10 . Said cap  30  is in this initial position at the beginning of the movement of positioning the cap  30  on the tube head  3 . This positioning, also referred to as capping, is carried out in particular on production lines. It is therefore important to allow a simple, reliable and repeatable kinematics to limit the production incidents. Advantageously, when the cap  30  is positioned on the tube head  3 , on the production lines, the cap  30  is guided on the neck  10  along a guide path  21 , along which it is simultaneously pushed towards the tube head and rotated counterclockwise. 
     When the cap  30  is in waiting position on the neck  10 , the punch  7  is held at a distance from the lid  5 . Said cap  30  is in this waiting position at the end of the initial positioning movement of the cap  30  on the tube head  3 . This is the position in which the assembly is sold before filling the tube. It is also in this waiting position that the assembly is sold to the consumer, after the tube has been filled. Such an assembly provides a hold in the waiting position without the use of an additional piece such as a spacing ring. 
     As illustrated in  FIGS. 15, 16 and 19 , when the cap  30  is in the closing position, said punch  7  has perforated said lid  5 . The cap  30  then hermetically seals the tube on which the assembly is adapted. The closing position can also be referred to as the position of use insofar as the cutting of the lid  5  determines the starting point of the use of the tube on which the closure assembly  1  according to the invention is mounted. In particular, the cap  30  may be intended to remain in the closing position. This is in particular the case when the punch  7  is in the form of a hollow barrel and has an opening, not shown, at the level of the upper face of the cap  30 . Thus, once the cap  30  is in the closing position on the neck  10 , the access to the internal volume of the tube on which the assembly is adapted is possible through said opening. According to an embodiment not shown, the opening of the neck  30  is closed by a cover connected to the cap  10 , the cap and the cover optionally forming a service cap. Thus, the cap  30  can be held in closing position on the neck  10  while allowing the access to the internal volume of the tube and the closing of this access. 
     In addition to said guide path  21 , said assembly comprises a threading  22  and a thread portion  11  allowing a positioning of the cap  30  on the neck  10  by cooperation with the guide path  21  and the threading  22 . The guide path  21  and threading  22  are most particularly visible in  FIGS. 1 to 4 , while the thread portion  11  is most particularly visible, in transparency, in  FIGS. 5 to 16 . 
     As more particularly illustrated in  FIGS. 5 and 6 , when guiding from the initial position to the waiting position, said thread portion  11  cooperates with the guide path through a front end  12  of said thread portion  11 . 
     As more particularly illustrated in  FIGS. 11 to 16 , said thread portion  11  is intended to cooperate with said threading  22  by screwing. 
     Said cap comprises a lateral skirt  23  having an inner face at the level of which said thread portion  11  is located. Said thread portion  11  has a substantially trapezoidal cross-section, intended to cooperate with the threading  22 . Said thread portion  11  extends longitudinally along the axis A, radially inwardly of the cap  30  from the skirt  23  and angularly between its front end  12  and a rear end  13 . The angular span of said thread portion is, for example, between 30 and 90°. 
     According to a first aspect of the invention, said assembly comprises a first stop  24  and a second stop  25  for said thread portion  11 . Said stops are angularly spaced and define a passage  26  between the guide path  21  and the threading  22 . Said assembly is configured to allow axial displacement of the thread portion  11  through the passage  26 . Furthermore, once said thread portion  21  has passed through said passage  26 , at least one of said stops, here the first stop  24  is configured to prevent a return of said thread portion  21  through said passage  26 . The cap  30  is then blocked on the neck  10  by snap-fit and can no longer be released from the neck  10 . 
     Such a kinematics allows to clearly identify the arrival in the waiting position by modifying the trajectory of the cap  30  which passes here from a movement including a rotation along the guide path  21  to an axial movement to cross said passage  26  rather than a kinematics according to which the arrival in the waiting position is done in the continuity of a screwing. Furthermore, the neck  10  has an outer partition  14  which remains smooth without a rib or groove at the level of said passage  26 , the snap-fit effect of said thread portion  11  being solely due to the angular span of said passage  26 , which is selected to be smaller than a span of said thread portion  11 . The precision of such dimensions is more easily controlled than a radial dimension and may be less than a tenth of a millimeter, in particular in the case of an injection molding of said tube head  3  and/or said cap  30 . 
     In the illustrated embodiment, said cap is in said waiting position after passing through said passage  26 . In other words, said guide path  21  allows the passage from the initial position to the waiting position and said threading  22  allows the passage from the waiting position to the closing position. 
     Advantageously, one of the two between the guide path  21  and the threading  22  induces a screwing in a clockwise direction of rotation of the cap  10 , the other of the two between the guide path  21  and the threading  22  inducing a screwing in a counterclockwise direction of rotation of the cap  10 . Here, the guide path  21  induces counterclockwise rotation of the cap  10  and the threading  22  induces clockwise rotation of the cap  10 . 
     Preferably, the neck  10  comprises the guide path  21  as well as the threading  22  while the cap  30  comprises the thread portion  11 . 
     Here, the first stop  24  forms one end of said guide path  21 . Said assembly further comprises a shoulder  27  connecting an origin of a first thread  28  of the threading  22  and the first stop  24 . Thus, the origin of the first thread  28  and the first stop  24  are axially spaced apart. In particular, the first stop  24  forms a rounding joining said guide path  21  and said shoulder  27 . 
     The second stop  25  is formed, for example, by an axial partition. The second stop  25  forms the origin of a second thread  29  of the threading  22 . 
     Said second thread  29  advantageously forms a low axial stop when said thread portion  11  passes through said passage  26 . 
     Preferably, said assembly comprises a third stop  31  configured to block a screwing of the cap  30  after the cap  30  has been positioned on the neck  10  and more precisely, here, when said cap  30  is in waiting position. 
     In other words, in waiting position, the thread portion  11  is blocked axially upwards by the first stop  24  and downwards by the second thread  29 , unscrewing by the second stop  25  and screwing by the third stop  31 . 
     In  FIGS. 7 and 8 , the thread portion  11  is crossing the passage  26 , while in  FIGS. 9 and 10 , said thread portion  11  is positioned between the various stops mentioned in the previous paragraph. 
     Said third stop  31  comprises, for example, a wall  32 , extending transversely from a bottom partition of the threading  22 . Said wall  32  here has a constant thickness. Said assembly has a sharp angle between the wall  32  and the second thread  29 . Said wall  32  extends radially between a bottom of the threading  22  and a free distal edge and axially between said second thread  29  and a free radial edge. Preferably, said wall  32  extends axially partially through said threading  22 . The axial extension of said wall  32  allows to adjust the torque required to pass said third stop  31 . 
     Preferably, an angular extension between the second  25  and the third  31  stops is just greater than an angular extension of the thread portion  11 . Said third stop  31  is positioned here under said first thread  28 , being slightly angularly offset from said first stop  24  in the screwing direction. 
     Said guide path  21  is formed, for example, by a third thread ending on the first stop  24 . 
     Once said third stop  31  is passed, said thread portion  11  is configured to slide by screwing between the first  28  and the second  29  threads. 
     In the further movement of the cap  30 , said neck  10  and said cap  30  are configured to guide the cap  30  on the neck  10 , here by screwing, to the closing position through an intermediate position, illustrated in  FIGS. 13 and 14 , in which the punch has finished piercing said lid  5 . In the case where, as illustrated, the punch  7  comprises a plurality of teeth  50 , said intermediate position is the position occupied by the punch  7  when all the teeth  50  have pierced said lid  5 . 
     Furthermore, as already mentioned, said neck  10  and said cap  30  are configured so that the guiding, in this case the screwing, of the cap  30  onto the neck  10  causes a deformation of the material making the closure tight. 
     According to a second aspect of the invention, said assembly is configured so that the passage through the intermediate position takes place prior to the deformation of the material sealing the closure. Such a configuration is obtained by the choice of the axial dimensions of the punch  7  and neck  10 . Such sequencing allows to avoid the need to provide a too high torque compared to a configuration in which a seal would begin before the end of the piercing. The seal can be performed when the lid  5  is cut, after the piercing is complete. It was indeed found by the applicant that the torque required for the cutting is much lower than that for the piercing. 
     Advantageously, said cap  10  and said neck  30  are configured so that said intermediate position is located downstream of the waiting position according to the direction of guiding, in particular screwing, the cap  30  to the closing position. In other words, in the example illustrated in relation to the first aspect of the invention, said assembly is configured so that said thread portion  11  has passed said third stop  31  before the piercing of the lid begins. 
     Taking  FIGS. 11 and 12  and  FIG. 17  together, it can be seen that the punch  7  comes into contact with the lid  5  while the thread portion  11  is still interacting with the third stop  31 . However, the piercing of the lid  5  does not begin immediately after the screwing movement. Indeed, the lid  5  is elastic so that it is deformed before being pierced. Thus, the piercing only begins in a position between that shown in  FIGS. 11 and 12  and that shown in  FIGS. 13 and 14 . 
     Advantageously, as will be developed below in connection with the third aspect of the invention, said assembly further comprises a non-return stop  33  configured to prevent the cap  30  from moving out of the closing position. Even more advantageously, said assembly is configured so that said non-return stop  33  is passed by the cap  10  after passing to intermediate position. In other words, as illustrated in  FIGS. 13 and 14 , said cap  10  does not yet cooperate with said non-return stop  33  when the cap  10  is in said intermediate position. 
     The sealing of the closure can be achieved in different ways. In this case, the seal is obtained by cooperation of an inner partition of the neck  10  and an outer partition of the punch  5 . 
     As illustrated in  FIGS. 17 to 19 , said punch  7  comprises a base  34  having an outer cylindrical portion  35  and said neck comprises an inner cylindrical portion  36 , said inner  36  and outer  35  cylindrical portions being intended to be crushed against each other to achieve sealing of said closure. In this way, a cylinder-to-cylinder seal is achieved, which has the advantage of requiring less torque than that required for the compression of a seal that would be located on an upper free edge of the neck. 
     Said cap  30  herein comprises a top  37  from which said base  34  of the punch  7  extends. Said punch  7  further comprises an external chamfer  38  extending from said base  34  and connected to a distal part  39  of the punch  7 . Said neck  10  comprises at its outwardly opening end an internal chamfer  40  extended axially by said portion  36  of the neck  10  against which the base  34  of the punch  7  is intended to be crushed. 
     In  FIG. 17 , upstream of the intermediate position, according to the screwing direction of the cap  30 , it can be seen that the chamfer  38  of the punch is axially at a distance from the chamfer  40  of the neck. In  FIG. 18 , in said intermediate position, the chamfer  38  of the punch has just come to rest against the chamfer  40  of the neck. In  FIG. 19 , in the closing position, a compression of material has occurred between the base  34  of the punch and the corresponding portion  36  of the neck  10 . 
     Advantageously, in order to limit the required torque, said distal part  39  of the punch has an outer diameter smaller than an inner diameter of the neck  10 . 
     According to a third aspect of the invention, the lateral skirt  23  is provided with at least one notch  60  opening radially and said neck  10  comprises a protrusion  61  configured to cooperate angularly with said notch  60  to block a withdrawal of the cap  30 , once said cap is in said closing position. Said protrusion  61  forms the aforementioned non-return stop  33 . Such a non-return stop  33  has the advantage that it is not located in the threading  23 . It is therefore not susceptible to be damaged by the thread portion  11  during the passage of the latter to the closing position. In other words, in the illustrated embodiment, said thread portion  11  reaches said closing position by passing away from said protrusion  61 . 
     Preferably, said notch  60  is open at a free edge of said skirt  23  so as to impart a radial elasticity to the cap  30  in the vicinity of said notch  60 . Such elasticity has many advantages. Firstly, it limits the torque required to reach the closing position by overcoming said non-return stop  33 . In addition, it facilitates an axial demolding of the thread portion  11 . The notch  60  is, for example, substantially rectangular. 
     Advantageously, said protrusion  61  is configured to radially spread said skirt  23  before arrival of the cap  30  in the closing position. For this purpose, herein, said protrusion has an edge provided with an inclined portion  62  and a straight portion  63 . Said straight portion  63  axially extends the inclined portion  62  toward a base of the neck  10 . Said inclined portion  62  is configured to radially spread said cap  10  by pressing on a free edge of said skirt  23  before the cap  10  reaches the closing position. Said straight portion  63  is located at the level of a part of the protrusion  60  forming the non-return stop  33  for the cap  10  once in the closing position. More precisely, the notch  60  has an axial edge  64  bearing against a flank of said protrusion  33 , the latter forming said non-return stop  33 . 
     The protrusion  61  is formed, for example, by a wall extending radially from the outer partition  14  of the neck. Said wall has an upper free edge  65  terminating the second thread  29 . Said protrusion  61  extends axially from the terminal end  65  of said second thread  29 , here forming a lower thread of the threading  22 , to the base of the neck  10 . Said non-return stop  33  is intended to cooperate with the rear end  13  of the thread portion  11 . 
     Advantageously, said assembly further comprises a stop  70 , in particular angular, for the end of stroke of the cap  10  in the closing position. Said end of stroke stop  70  is configured to cooperate with said thread portion  11 , once said protrusion  61  is engaged in said notch  60 . Said end of stroke stop  70  is intended to cooperate with the front end  12  of the thread portion  11 . Said return stop  70  here extends axially between the first thread  28  and the base of the neck. 
     In the illustrated embodiment, said assembly comprises a plurality of said thread portions  11  and a corresponding plurality of said threadings  22 , in this case three, spaced at 120°. Said assembly further comprises a plurality of said notches  60  and a corresponding plurality of said protrusions  61 , herein three, each of the thread portions  11  being angularly located between two adjacent ones of said notches  61 . Said lateral skirt  23  thereby has flaps having a good radial flexibility between said notches  60 , said thread portions being located at the level of said flaps. 
     In this configuration with various threadings  22 , the first thread  28  of one of the threadings forms the second thread  29  of the adjacent threading  22 . 
     In the upper part, the second stops  25  extend axially between an origin of the third thread forming the guide path  21  associated with one of the threadings  22  and the second thread  29  of the adjacent threading  22  in the clockwise direction. 
     In the lower part, the end of stroke stop  70  of one of the threadings  22  is located angularly, clockwise, just upstream of the protrusion  60  of the adjacent threading  22  in the counterclockwise direction. The first thread  28  of one of the threadings  22  continues into an end portion of the second thread  29  of the adjacent threading  22  in a counterclockwise direction. 
     As illustrated in  FIGS. 17 to 20 , the or said teeth  50  are advantageously configured to pierce and then cut said lid  5 . The or said teeth  50  extend from a free edge  80  of the punch  7 . 
     According to a fourth aspect of the invention, at least one angular portion  81  of said free edge  80 , referred to as the passage portion, is configured to remain in the neck  10  in said closing position as is more particularly apparent from  FIG. 19 . Such a configuration improves the rate of restitution of the product contained in the tube by allowing a fraction of the product located in the vicinity of a shoulder  4  of the tube head  3  to circulate in the neck  10  at the level of said passage portion  81 . Advantageously, said passage portion  81  is flush with a lower end of the neck  10  opening into the interior volume of the tube. 
     Here, said teeth  50  are distributed over an angular portion  82  of the punch  7 , referred to as the cutting portion, delimited by two of said teeth  50  located angularly on either side of said cutting portion  82 . Said passage edge  81  is formed by an angular portion of the punch complementary to said cutting portion  82 . 
     As is better illustrated in  FIG. 20  where a fictitious plane P extending orthogonally to said longitudinal axis A has been shown, said teeth  50  have tops  51  axially offset from each other. Such a configuration allows to limit the screwing torque by ensuring that the teeth  50  pierce the lid  5  successively. The axial offset of the top of the teeth  50  increases, in particular regularly, and even more particularly linearly, in a direction of displacement of the cap  10  towards said closing position, in other words, here, according to the screwing direction or clockwise direction (which corresponds to a counterclockwise direction in  FIG. 20  since the latter is reversed). Thus, the tooth  50  located at a terminal end of the cutting portion  82  in the clockwise direction (counterclockwise in  FIG. 20 ) has the most protruding top and meets the lid  5  first. 
     According to a fifth aspect of the invention, said teeth  50  have a substantially identical height and extend axially from an angular portion of the free edge of the punch  7  having an axial offset from one tooth  50  to the other. To that end, here, said free edge in said cutting portion  82  is in the form of a ramp of increasing height in the clockwise direction (counterclockwise in  FIG. 20 ). Such an identical height of the teeth allows to limit their risk of breakage compared to a configuration in which one would meet teeth of too small sizes. 
     As illustrated, said teeth  50  preferably have a substantially identical profile. This is, for example, a profile with a leading edge  52  extending substantially axially between said free edge  80  and each top  51  and a return edge  53  extending in an inclined manner between each top  51  and said free edge  80 . Said tops  51  are here formed at the junction of the leading edge  52 , the return edge  53 , an outer flank  54  of the tooth and an inclined surface  55  formed in the thickness of the teeth  50 . 
     In addition to the assembly shown in the preceding figures, said tube according to the invention comprises a skirt  102 , partially illustrated, connected to said tube head  3 .