Abstract:
A liquid dispensing device includes a dispensing end piece and a neck of a reservoir for storing the liquid, the end piece being attached to the neck, which has a tubular internal surface. The end piece has a tubular internal skirt that is mounted in the neck and defines, with the internal surface, at least one annular sealing zone, preventing the liquid from passing between the internal skirt and the neck. The skirt defines, with the internal surface, a separate zone for retaining shavings, which prevents shavings that are formed in the sealing zone while the end piece is being fitted into the neck from getting into the reservoir.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to the dispensing of liquid, more particularly to the dispensing in the pharmaceutical field of, for example, ophthalmic, nasal, buccal or auricular liquid. The term “liquid product” is intended to mean a non-solid and non-gaseous product which is more or less viscous. 
       BACKGROUND OF THE INVENTION 
       [0002]    Dispensing devices comprising a liquid storage reservoir and a dispensing end piece attached to a neck of the reservoir, for example by screwing, are already known, in particular from patent application FR2980378. The reservoir and the dispensing end piece are made of plastic. To ensure liquid sealing of the device, a part of the dispensing end piece is intended to come into leaktight contact with the internal surface of the neck of the reservoir so as to create a sealing zone. This contact can be achieved by an annular bead on the reservoir, or alternatively by face-to-face contact. 
         [0003]    It is found that screwing the dispensing end piece onto the neck of the reservoir is carried out at a high speed (for example greater than 300 rotations per minute), which can generate chips of material resulting from friction between the dispensing end piece and the neck of the reservoir at the sealing zone. These chips risk falling into the liquid contained in the reservoir and contaminating it, or else disturbing the operation of the dispensing end piece. This phenomenon is not desirable, especially when the liquid is pharmaceutical liquid. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention aims to provide a dispensing device ensuring better conservation and better dispensing of the liquid. 
         [0005]    Accordingly, a subject of the invention is a liquid dispensing device comprising a dispensing end piece and a neck of a reservoir for storing the liquid, the dispensing end piece being attached to the neck,
       the neck having an internal surface of substantially tubular general shape,   the dispensing end piece having an internal skirt of substantially tubular general shape which is mounted inside the neck of the reservoir and which defines, with the internal surface of the neck, at least one annular sealing zone such that liquid present in the reservoir cannot pass between the internal skirt of the dispensing end piece and the neck of the reservoir,   the internal skirt of the dispensing end piece defining, with the internal surface of the neck, a separate chips retention zone arranged upstream of the sealing zone with respect to the reservoir, this retention zone being configured such that chips formed at the sealing zone while the dispensing end piece is being assembled on the neck of the reservoir cannot get into the reservoir.       
 
         [0009]    Thanks to the chips retention zone, it is possible to block all the particles which may be created during assembly, resulting from friction between the interior of the reservoir and the end piece, and therefore to avoid a situation in which these particles fall into the reservoir and contaminate the liquid contained in the reservoir, or else impair the operation of the dispensing end piece, for example by clogging channels. Thus, the chips retention zone forms a barrier arranged between the sealing zone and the reservoir to retain any chips which might be formed when the internal surface of the neck of the reservoir is docked with the internal skirt of the dispensing end piece. 
         [0010]    It will be noted that the dispensing end piece can be assembled on the neck of the reservoir in various ways, in particular by screwing, force-fitting, or else by snap-fastening. The retention zone is particularly advantageous in the case where assembly of the dispensing end piece on the reservoir is carried out in a very rapid manner, quite particularly during a screwing operation at high speed, for example greater than 300 rotations per minute. Specifically, during rapid assembly, more chips may be formed at the sealing zone since the material does not have time to deform to compensate for the tightening that generates the sealing zone. It will be understood that in the advantageous case where the dispensing end piece is attached to the neck by screwing, to ensure this screwing, the dispensing end piece comprises a threaded surface and the neck of the reservoir comprises a complementary tapped surface. 
         [0011]    It will be noted that the dispensing device is particularly advantageous since it could have been envisioned, alternatively, to make changes to the materials for producing the reservoir and the dispensing end piece. Nevertheless, the results obtained with the device presented above are more advantageous for avoiding chips. Specifically, for example when using a polypropylene bottle, we get a more rigid bottle which is more difficult to use and whose cost is higher. 
         [0012]    It will be noted moreover that the chips retention zone is separate from the sealing zone. Specifically, this retention zone has the function of being interposed between the reservoir and the sealing zone where chips risk being created, and therefore does not have the primary function of providing liquid sealing, even though it is not excluded from being able to do so. The term “chips retention zone separate from the sealing zone” is understood to mean the fact that the juxtaposition of the two zones is different from an exactly cylindrical and plane surface. Moreover, the term “chips” is understood to mean particles of any form which may be created by the dispensing end piece and/or the reservoir during assembly of the two parts, in particular by screwing. The chips are for example in the form of filaments or dust. 
         [0013]    The invention may additionally comprise one or more of the following features, taken alone or in combination. 
         [0014]    The internal surface of the neck of the reservoir has a general diameter and it comprises a convex annular shape projecting from the internal surface of the neck so as to define a reduced diameter with respect to the general diameter of the neck of the reservoir and thus to form, by cooperation with the internal skirt of the dispensing end piece, the chips retention zone. Thus, a protuberance forming an inflection is produced on the internal surface of the neck so as to retain chips resulting from screwing the dispensing end piece onto the reservoir. Preferably, the convex annular shape has a gentle inflection with respect to the internal surface of the neck in order not to create new chips at the chips retention zone during the contact which is produced. Moreover, the reduced diameter is preferably smaller than the diameter of the neck of the reservoir at the sealing zone. It will be noted that it is particularly advantageous to produce these variations in diameter on the internal surface of the neck of the reservoir rather than on the internal skirt of the dispensing end piece, since it can facilitate assembly of the two parts. 
         [0015]    The device is configured such that, when assembling the dispensing end piece on the neck of the reservoir, the internal skirt of the dispensing end piece comes into contact with the internal surface of the neck of the reservoir first at the sealing zone and then at the chips retention zone. Thus, the contact of the retention zone takes place at the end of assembly, during which moment the assembly force is smaller, in particular the screwing torque during assembly by screwing. Thus, chips are not created between the internal surface of the neck of the reservoir and the skirt of the dispensing end piece at the chips retention zone. Furthermore, the formation of the sealing zone takes place as a priority, thereby ensuring that this sealing zone will be formed whatever the manufacturing tolerances of the parts. 
         [0016]    The neck of the reservoir has a length L neck min  delimited by the upper end of the length of the neck providing sealing L neck sealing  and the upper end of the length of the neck providing the chips retention zone L neck retention , the dispensing end piece has a length L end piece max  delimited by the lower end of the length of the end piece providing sealing L end piece sealing  and the lower end of the length of the end piece providing the chips retention zone L end piece retention , the device being such that L neck min &gt;L end piece max . By virtue of this configuration, when assembling the dispensing end piece on the neck of the reservoir, the internal skirt of the dispensing end piece comes into contact with the internal surface of the neck of the reservoir first at the sealing zone and then at the chips retention zone. 
         [0017]    The internal surface of the neck of the reservoir at the sealing zone is substantially plane, sealing with the internal skirt of the dispensing end piece being realized by face-to-face contact of the internal skirt of the dispensing end piece with the internal surface of the neck of the reservoir. The term “face-to-face contact” is here understood to mean any type of sealing contact produced between two plane surfaces of revolution, such as a cylinder-against-cylinder contact, a cylinder-against-cone contact and a cone-against-cone contact. It will be noted that in the case of such a face-to-face contact to produce sealing, the assembly force may be relatively high since the friction surface is greater. However, as the contact is produced progressively, the risk of creating chips is reduced. 
         [0018]    The internal surface of the neck of the reservoir at the sealing zone comprises an annular bead. 
         [0019]    The internal surface of the neck of the reservoir comprises, downstream and in the direct vicinity of the sealing zone, an annular recess. This recess allows the contact surface in the sealing zone to be as localized as possible, so as to create fewer chips. Furthermore, this recess makes it possible to produce an upper part of the neck having a minimal thickness and capable of forming a stop with the bottom of a groove formed by the internal skirt of the dispensing end piece. As this thickness is minimal, the stop between the top of the neck of the reservoir and the bottom of this groove is more clearly defined, thereby making it possible to create a second liquid sealing zone which is particularly effective. 
         [0020]    The neck of the reservoir is made of low density polyethylene and the internal skirt of the dispensing end piece is made of high density polyethylene. Thus, the reservoir is made of a flexible material, enabling the liquid to be readily dispensed by pressure exerted by the user, and the dispensing end piece is made of a more rigid material, thereby making it possible to facilitate the assembly of the parts and to ensure an effective sealing of the dispensing device. In this case, the chips are mainly created on the reservoir and the retention zone proposed in the present device is particularly advantageous. 
         [0021]    The end of the internal skirt of the dispensing end piece situated on the side facing the reservoir has a funnel shape. This has the effect of facilitating assembly of the dispensing end piece with the reservoir. 
         [0022]    Another subject of the invention is a liquid storage reservoir for a device as described above, in which the internal surface of the neck of the reservoir has a predetermined diameter at the sealing zone, referred to as sealing diameter, and a predetermined diameter at the retention zone, referred to as chips retention diameter, the chips retention diameter being smaller than the sealing diameter. 
         [0023]    A further subject of the invention is a method for assembling a device as described above, during which the internal skirt of the dispensing end piece comes into contact with the internal surface of the neck of the reservoir first at the sealing zone and then at the chips retention zone. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The invention will be better understood on reading the following description given solely by way of example with reference to the drawings, in which: 
           [0025]      FIG. 1  is a sectional view in longitudinal direction of a device according to a first embodiment, 
           [0026]      FIG. 2  is a view, similar to  FIG. 1 , of a device according to a second embodiment, 
           [0027]      FIG. 3  is a view, similar to  FIG. 1 , of a device according to a third embodiment, 
           [0028]      FIG. 4  is a schematic view illustrating the relative positions of the sealing zones and the chips retention zones, and 
           [0029]      FIG. 5  is a sectional view in longitudinal direction of the reservoir of the device of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]      FIG. 1  illustrates a device  10  for dispensing liquid in the form of drops that comprises a reservoir  12  to which is attached a dispensing end piece  14  over which a protective cap  18  (visible in  FIG. 2  or  FIG. 3 ) can be mounted. The reservoir  12  comprises a neck  38  for receiving the dispensing end piece  14 . 
         [0031]    The dispensing end piece  14  has an upper dispensing end  20  in which an orifice  16  is formed for dispensing calibrated drops, in this example, by drops formation means  16 . More precisely, again in this example, the dispensing end piece  14  is of substantially cylindrical general shape. The dispensing end piece  14  here comprises a drop dispensing valve  22  made of elastomer material so as to take, under the pressure of the liquid (when the user presses on the reservoir  12 ), a liquid passage configuration. The dispensing end piece  14  further comprises a valve support  24 , attached to the reservoir  12 , bearing a pin  26  forming a seat against which the valve  22  is pressed and also comprising an air passage duct  28  shut off by an air-permeable member  30  preventing bacteria from entering into the reservoir  12 . The dispensing end piece  14  also comprises a return element  32  allowing the valve  22  to be returned into a liquid blocking configuration. Finally, the dispensing end piece  14  comprises a cover  34  for pressing the valve  22  against the support  24 . 
         [0032]    More precisely, the valve support  24  comprises an internal skirt  40  of substantially tubular general shape, which is mounted inside the neck  38  of the reservoir  12 , and also an external skirt  41  surrounding the neck  38  of the reservoir  12  and having, for example, a tapped surface for screwing the dispensing end piece  14  onto the reservoir  12 . The tapped surface is situated on the inner side of the external skirt  41 . The internal skirt  40  has a lower end of funnel shape in order to facilitate the insertion of the dispensing end piece  14  into the neck  38  of the reservoir  12 . In the device  10  of  FIG. 1 , the neck  38  has a substantially tubular internal surface  42  having a general diameter and comprising an annular bead  44 . The annular bead  44  forms a sealing zone  46  with the internal skirt  40  of the dispensing end piece  14 . When screwing the dispensing end piece  14 , the internal skirt  40  comes into contact with the annular bead  44  at a high speed, which can generate chips of plastics material, for example in the form of filaments, which risk falling into the reservoir  12  and contaminating the liquid contained in the reservoir  12 . 
         [0033]    The internal surface  42  of the neck  38  further comprises a convex annular shape  48  projecting from the internal surface  42  of the neck  38  so as to define a reduced diameter with respect to the general diameter, referred to as chips retention diameter D R , represented in  FIG. 1 . This chips retention diameter D R  is smaller than the general diameter D of the neck  38  of the reservoir  12 , and also smaller than the diameter D E  of the neck  38  of the reservoir  12  at the sealing zone  46 , referred to as sealing diameter D E . This convex shape  48  produces, by cooperation with the internal skirt  40  of the dispensing end piece  14 , a chips retention zone  50 . When the dispensing end piece  14  is mounted on the neck  38  of the reservoir  12 , by screwing, the chips created by friction between the neck  38  and the skirt  40  in the sealing zone  46  are blocked in this chips retention zone  50  and cannot fall into the reservoir  12 . It will be understood that the neck  38  of the reservoir has a threaded external surface in order to screw the dispensing end piece  14  onto the reservoir  12 , by cooperation with the tapped surface of the external skirt  41 . 
         [0034]    In the embodiment in  FIG. 2 , the internal surface  42  of the neck  38  does not comprise an annular bead but is substantially plane in the sealing zone  46 . In this example, sealing between the internal surface  42  and the internal skirt  40  is achieved by face-to-face contact, in this instance a cylinder-against-cylinder contact of the two tubular surfaces of the skirt  40  and the internal surface  42 . The internal surface  42  of the neck  38  also comprises a convex annular shape  48  projecting from the internal surface  42  so as to form, by cooperation with the internal skirt  40  of the dispensing end piece  14 , a chips retention zone  50 . In this case, the contact surface is more extensive, without pointed contact, the risk of creating chips is thus reduced. 
         [0035]    In  FIG. 3 , sealing between the internal surface  42  and the internal skirt  40  is also provided by cylinder-against-cylinder contact. Unlike the example illustrated in  FIG. 2 , the internal surface  42  of the neck  38  comprises, downstream and in the direct vicinity of the sealing zone  46 , an annular recess  52 . As the chips are created in the sealing zone  46 , it is preferable that the contact surface in the sealing zone  46  is as localized as possible. Thus, the screwing torque will be reduced and fewer chips will be created. 
         [0036]    When assembling the dispensing end piece  14  on the reservoir  12 , the internal skirt  40  is inserted into the neck  38  of the reservoir  12  and the contact with the retention zone  50  takes place after contact with the sealing zone  46 . In order to illustrate the configuration of the parts to ensure this order of contact, a schematic view illustrating the relative positions of the sealing zones  46  and the chips retention zones  50  is represented in  FIG. 4 . 
         [0037]    The internal surface  42  of the neck  38  and the internal skirt  40  each have a theoretical length in the longitudinal direction L 1 =L neck theoretical sealing  and L 2 =L end piece theoretical sealing  which are intended to provide sealing, producing the sealing zone  46 . 
         [0038]    The theoretical length of the neck  38  L 1 =L neck theoretical sealing  defines, with reference to the upper end  60  of the neck  38 , a minimum theoretical distance D 1 =D neck theoretical sealing min  and a maximum theoretical distance D 2 =D neck theoretical sealing max . 
         [0039]    The theoretical length of the dispensing end piece  14  L 2 =L end piece theoretical sealing  defines, with respect to the bottom of the groove  100  of the dispensing end piece  14 , a minimum theoretical distance D 3 =D end piece theoretical sealing min  and a maximum theoretical distance D 4 =D end piece theoretical sealing max . 
         [0040]    To ensure that there is sealing, that is to say that at least a part of the length L 1 =L neck theoretical sealing  of the internal surface  42  of the neck  38  is in contact with at least a part of the length L 2 =L end piece theoretical sealing  of the internal skirt  40  of the dispensing end piece  14 , it is required that the following holds simultaneously:
       i) D 1 =D neck theoretical sealing min &lt;D end piece theoretical sealing max =D 4  and that   ii) D 3 =D end piece theoretical sealing min &lt;D neck theoretical sealing max =D 2 .       
 
         [0043]    Thus, when the end of the neck  38  and the bottom of the groove  100  of the dispensing end piece  14  are in contact, the sealing is guaranteed. 
         [0044]    Likewise, the conditions for the chips retention zone  50  to exist can be understood. The internal surface  42  of the neck  38  and the internal skirt  40  each have a theoretical length in the longitudinal direction L 3 =L neck theoretical retention  and L 4 =L end piece theoretical retention  which are intended to provide the retention zone, producing the chips retention zone  50 . 
         [0045]    The theoretical length of the neck  38  L 3 =L neck theoretical retention  defines, with reference to the upper end  60  of the neck  38 , a minimum theoretical distance D 5 =D neck theoretical retention min  and a maximum theoretical distance D 6 =D neck theoretical retention max . 
         [0046]    The theoretical length of the dispensing end piece  14  L 4 =L end piece theoretical retention  defines, with reference to the bottom of the groove  100  of the dispensing end piece  14 , a minimum theoretical distance D 7 =D end piece theoretical retention min  and a maximum theoretical distance D 8 =D end piece theoretical retention max . 
         [0047]    To ensure that there is the retention zone, that is to say to ensure that at least a part of the length L 3 =L neck theoretical retention  of the internal surface  42  of the neck  38  is in contact with at least a part of the length L 4 =L end piece theoretical retention  of the internal skirt  40  of the dispensing end piece  14 , it is required that the following holds simultaneously:
       iii) D 5 =D neck theoretical sealing min &lt;D end piece theoretical sealing max =D 8  and that   iv) D 7 =D end piece theoretical sealing min &lt;D neck theoretical sealing max =D 6 .       
 
         [0050]    Thus, when the end of the neck  38  and the bottom of the groove  100  of the dispensing end piece  14  are in contact, the chips retention zone  50  is guaranteed. 
         [0051]    In the following, the configurations allowing the contact of the retention zone  50  to take place after the contact of the sealing zone  46  are developed. 
         [0052]    The minimum theoretical distances on the neck D 1 =D neck theoretical sealing min  and D 5 =D neck theoretical retention min  define a length of the neck L 5 =L neck min , delimited by the upper end of the theoretical length providing sealing and the upper end of the theoretical length providing the retention zone. Moreover, the maximum theoretical distances on the end piece D 4 =D end piece theoretical sealing max  and D 8 =D end piece theoretical retention max  define a length of the end piece L 6 =L end piece max , delimited by the lower end of the theoretical length providing sealing and the lower end of the theoretical length providing the retention zone. 
         [0053]    To ensure that the contact of the retention zone  50  takes place after the contact of the sealing zone  46 , it is required that the following holds: L 5 =L neck min &gt;L 6 =L end piece max . 
         [0054]    It will be understood that a “theoretical” length denotes a predefined length on the neck of the reservoir or the dispensing end piece at the time of designing or manufacturing these parts, knowing that, due to the manufacturing tolerances, once the parts have been assembled, sealing or chips retention does not necessarily take place over the entire theoretical length, but only over a part of this length. Thus, it can be found that on the devices configured according to this embodiment the neck of the reservoir has a length L neck min  delimited by the upper end of the length of the neck providing sealing L neck sealing  and the upper end of the length of the neck providing the chips retention zone L neck retention , the dispensing end piece has a length L end piece max  delimited by the lower end of the length of the dispensing end piece providing sealing L end piece sealing  and the lower end of the length of the dispensing end piece providing the chips retention zone L end piece retention , and the device is dimensioned such that L neck min &gt;L end piece max . 
         [0055]    As can be seen in  FIG. 5 , the reservoir  12  is configured such that the internal surface  42  of the neck  38  has a sealing diameter D E  greater than the chips retention diameter D R . 
         [0056]    It will be noted that the neck  38  of the reservoir  12  is made, in this example, of low density polyethylene, and the internal skirt  42  of the dispensing end piece  14  is made of high density polyethylene. 
         [0057]    It will be understood that the devices  10  described above are particularly advantageous for avoiding the presence of chips in the reservoir  12  and that the invention is not limited to the examples described above.