Patent Publication Number: US-7213727-B2

Title: Nozzle for a liquid container and a liquid container

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a nozzle for a liquid container which can securely prevent a liquid leak and a liquid dripping from a nozzle, and a liquid container provided with such a nozzle. 
   2. Description of the Related Art 
   There has been conventionally proposed a liquid container constructed such that a container body containing a liquid such as an eye-drop, a nose-drop or a contact-lens cleaning solution is pressed by fingers to cause the content liquid to drip from a discharging hole of a nozzle. 
   A known liquid container as above is normally comprised of three members: a container body  1 , a nozzle  2  and a cap  3  as shown in  FIGS. 13A and 13B . The nozzle  2  is mounted by hermetically bringing an outer circumferential surface  2   b  of a lower portion  2   a  of the nozzle  2  into contact with an inner circumferential surface  1   b  of a tubular neck portion  1   a  of the container body  1 . The cap  3  is mounted by bringing an inner circumferential surface  3   a  of the cap  3  into contact with an outer circumferential surface  1   c  of the tubular neck portion  1   a  while an internal thread  3   b  formed in the inner circumferential surface  3   a  of the cap  3  is engaged with an external thread  1   d  formed on the outer circumferential surface  1   c  of the tubular neck portion  1   a , and pressing an inner top surface  3   c  of the cap  3  against a top surface  2   d  of a discharging hole  2   c  of the nozzle  2  to provide a hermetic sealing for the discharging hole  2   c  as shown in Japanese Unexamined Patent Publication No. 9-156662. 
   This publication disclosed a liquid container of the so-called screw cap type. The cap  3  can be loosened and detached by being turned by 360° in reverse direction. A plurality of (at least three or more) ring-shaped fins  2   e  whose edges are elastically deformed to be hermetically brought into contact with the inner circumferential surface  1   b  of the tubular neck portion  1   a  upon inserting the lower portion  2   a  of the nozzle  2  into the tubular neck portion  1   a  are formed at specified intervals while being vertical spaced apart. By this elastic deformation of the ring-shaped fins  2   e , the outer circumferential surface  2   b  of the lower portion  2   a  of the nozzle  2  and the inner circumferential surface  1   b  of the tubular neck portion  1   a  are attached to a higher degree and an occurrence of a crack in the tubular neck portion  1   a  due to dimensional errors of the tubular neck portion  1   a  and the nozzles  2  can be prevented. 
   Another known liquid container is, as shown in  FIGS. 14A and 14B , constructed such that an outer circumferential surface  2   b  of a lower portion  2   a  of a nozzle  2  is hermetically brought into contact with an inner circumferential surface  1   b  of a tubular neck portion  1   a  of a container body  1  and a cap  3  is mounted by engaging a locking arm  3   d  on an inner circumferential surface  3   a  of the cap  3  with a locking projection  1   e  on an outer circumferential surface  1   c  of the tubular neck portion  1   a  while bringing the inner circumferential surface  3   a  of the cap  3  into contact with the outer circumferential surface  1   c  of the tubular neck portion  1   a , and inserting a projection  3   e  on an inner top surface  3   c  of the cap  3  into a discharging hole  2   c  of the nozzle  2  to hermetically seal the discharging hole  2   c  while forcibly widening it as shown in Japanese Unexamined Patent Publication NO. 10-329855. 
   This publication discloses a liquid container of the so-called twist cap type. Upon detaching the cap  3 , the locking arm  3   d  and the locking projection  1   e  are disengaged by twisting the cap  3  by about 90°. 
   However, the former publication discloses the liquid container constructed such that the discharging hole  2   c  is hermetically sealed by pressing the inner top surface  3   c  of the cap  3  against the top surface  2   d  of the discharging hole  2   c  of the nozzle  2 , whereas the latter publication discloses the liquid container constructed such that the discharging hole  2   c  is hermetically sealed by inserting the projection  3   e  on the inner top surface  3   c  of the cap  3  into the discharging hole  2   c  of the nozzle  2  while forcibly widening the discharging hole  2   c . For example, there are problems that a sealing performance varies and a load exerted on the nozzle cracks the nozzle due to a variation in tightening torque in the case of the screw type cap of the former publication and due to a variation of assembling precision of parts such as the cap and the nozzle in the case of the twist type cap of the latter publication. There has been a demand for a nozzle structure which, regardless of the type of the cap, can securely prevent an occurrence of a liquid leak from the cap  3  and the discharging hole  2   c  of the nozzle  2  and has a sealing performance which is not influenced by variations in assembling precision and torque. 
   With the liquid containers disclosed in the respective publications, a content liquid “a” can be caused to drip from the discharging hole  2   c  of the nozzle  2  by pressing the container body  1  by fingers with the nozzle  2  faced substantially right down as shown in  FIG. 15A . However, if the nozzle  2  is, for example, inclined to face obliquely downward while being turned upside down as shown in  FIG. 15B , the content liquid “a” leaks out to an upper portion  2   f  of the nozzle  2  from the discharging hole  2   c . If the nozzle  2  is inclined to face obliquely upward in this state as shown in  FIG. 15C , the content liquid “a” may not be easily caused to drip since it runs down from the upper portion  2   f  to the tubular neck portion  1   a  of the container body  1  or it cannot be formed well into drops. Therefore, there has been a demand for a nozzle constructed such that a liquid leak from the nozzle can be securely prevented and drops can be easily formed independently of a dripping angle. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a nozzle for a liquid container and a liquid container which are free from the problems residing in the prior art. 
   It is another object of the present invention to provide a nozzle for a liquid container and a liquid container which can securely prevent a liquid leak and a liquid dripping from a nozzle and easily form liquid drops independently of a dripping angle. 
   According to an aspect of the present invention, a liquid container having a tubular neck portion is provided with a nozzle on a top of the tubular neck portion. A cap is mounted on the tubular neck portion. The nozzle includes a discharging hole hermetically sealed by an inner top portion of the cap, and a ring-shaped projection formed on an upper portion of the nozzle. 
   These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an enlarged front view in section showing a nozzle, a fitting portion of a container body and a cap of a liquid container of the screw cap type according to an embodiment of the invention. 
       FIG. 2  is an enlarged front view in section showing a nozzle, a fitting portion of a container body and a cap of a liquid container of the twist cap type according to another embodiment of the invention. 
       FIGS. 3A and 3B  are enlarged front views in section showing a liquid container of the hinge cap type and a cap according to still another embodiment of the invention, showing a state when an upper lid is closed, and another state when the upper lid is opened, respectively. 
       FIGS. 4A ,  4 B,  4 C and  4 D are a front view, a section, a plan view and a bottom view of the nozzle used in the liquid container shown in  FIGS. 1 and 2 . 
       FIGS. 5A and 5B  are a front view and a section of a first modified nozzle. 
       FIGS. 6A and 6B  are a front view and a section of a second modified nozzle. 
       FIGS. 7A and 7B  are a front view and a section of a third modified nozzle having two ring-shaped fins. 
       FIGS. 8A and 8B  are a front view and a section of a fourth modified nozzle. 
       FIGS. 9A and 9B  are a front view and a section of a fifth modified nozzle. 
       FIGS. 10A and 10B  are a front view and a section of a sixth modified nozzle. 
       FIGS. 11A ,  11 B,  11 C are front views in sections showing discharged states of a content liquid in a state where the nozzle is faced substantially right down, in a state where the nozzle is inclined to face obliquely downward, and in a state where the nozzle is inclined to face obliquely upward from the state of  FIG. 11B , respectively. 
       FIG. 12A  is an enlarged front view in section showing a nozzle, a fitting portion of a container body and a cap of a liquid container of the twist cap type according to a seventh modification, and  FIG. 12B  is a section taken along the line  12 B— 12 B in  FIG. 12A . 
       FIGS. 13A and 13B  are front views in section of a prior art liquid container, showing a state when a cap is mounted and when the cap is detached, respectively. 
       FIGS. 14A and 14B  are front views in section of another prior art liquid container, showing a state when a cap is mounted and when the cap is detached, respectively. 
       FIGS. 15A ,  15 B,  15 C are front views in sections showing discharged states of a content liquid in a state where a conventional nozzle is faced substantially right down, in a state where the conventional nozzle is inclined to face obliquely downward, and in a state where the conventional nozzle is inclined to face obliquely upward from the state of  FIG. 15B , respectively. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A preferred embodiment of the present invention will be described in detail. Referring to  FIGS. 1 and 2 , a container body  11 A of a liquid container  10 A of a screw cap type is integrally formed with a tubular neck portion  11   a  in its upper portion and an external thread  11   d  is integrally formed on an outer circumferential surface  11   c  of the tubular neck portion  11   a.    
   A nozzle  12  is so inserted that an outer circumferential surface  12   b  of a lower portion  12   a  is hermetically brought into contact with an inner circumferential surface  11   b  of the tubular neck portion  11   a , and is positioned along an inserting direction by the contact of a flange portion  12   g  formed at a boundary between the lower portion  12   a  and an upper portion  12   f  with the top surface of the tubular neck portion  11   a , and a discharging hole  12   c  is formed in a top surface  12   d  of the upper portion  12   f.    
   The material of the nozzle  12  is not particularly restricted provided that it is a synthetic resin suitable for the nozzle molding. However, in consideration of fittability to the tubular neck portion  11   a  and other factors, the nozzle  12  is preferably made of a so-called soft synthetic resin. Among soft synthetic resins, a low-density polyethylene (LDPE), a linear low-density polyethylene (LLDPE), a polypropylene (PP) are suitable for the above molding. A method for molding the nozzle  12  is not particularly restricted since the suitable method differs depending on the synthetic resin to be used. In the case of using the LDPE, LLDPE, PP or the like, the nozzle  12  is preferably molded by injection molding or extrusion molding. Further, an antibacterial treatment may be suitably applied if necessary. 
   The cap  13 A has an internal thread  13   b  integrally formed in an inner circumferential surface  13   a , and a projection  13   f  fittable into the discharging hole  12   c  of the nozzle  12  while defining a clearance thereto is integrally formed on an inner top surface  13   c.    
   Upon mounting the cap  13 A, the inner circumferential surface  13   a  of the cap  13 A is fitted to the outer circumferential surface  11   c  of the tubular neck portion  11   a  while engaging the internal thread  13   b  of the cap  13 A with the external thread lid of the tubular neck portion  11   a  of the container body  11 A, whereby the inner top surface  13   c  of the cap  13 A can be pressed against the top surface  12   d  of the discharging hole  12   c  of the nozzle  12  to hermetically seal the discharging hole  12   c . It should be noted that the top surface  12   d  of the discharging hole  12   c  of the nozzle  12  is elastically deformed when the inner top surface  13   c  of the cap  13 A is pressed against the top surface  12   d  and this deformed section is shown by crosshatching b. 
   Conversely, the cap  13 A can be loosened by being turned by about 360° in a direction opposite from the one in which the cap  13 A is turned upon being attached to the nozzle  12  and then can be detached. 
   In  FIG. 2 , the container body  11 B of the liquid container  10 B of the twist cap type is integrally formed with a tubular neck portion  11   a  in its upper portion and a locking projection  11   e  is integrally formed on an outer circumferential surface  11   c  of the tubular neck portion  11   a.    
   The nozzle  12  is so inserted that an outer circumferential surface  12   b  of a lower portion  12   a  is hermetically brought into contact with an inner circumferential surface  11   b  of the tubular neck portion  11   a , and is positioned along an inserting direction by the contact of a flange portion  12   g  formed at a boundary between the lower portion  12   a  and an upper portion  12   f  with the top surface of the tubular neck portion  11   a , and a discharging hole  12   c  is formed in a top surface  12   d  of the upper portion  12   f.    
   The material of the nozzle  12  is not particularly restricted provided that it is a synthetic resin suitable for the nozzle molding. However, in consideration of fittability to the tubular neck portion  11   a  and other factors, the nozzle  12  is preferably made of a so-called soft synthetic resin. Among soft synthetic resins, a low-density polyethylene (LDPE), a linear low-density polyethylene (LLDPE), a polypropylene (PP) are suitable for the above molding. A method for molding the nozzle  12  is not particularly restricted since the suitable method differs depending the synthetic resin to be used: In the case of using the LDPE, LLDPE, PP or the like, the nozzle  12  is preferably molded by injection molding or extrusion molding. 
   The cap  13 B has a locking arm  13   d  integrally formed on an inner circumferential surface  13   a , and a projection  13   e  fittable into the discharging hole  12   c  of the nozzle  12  while forcibly widening the discharging hole  12   c  of the nozzle  12 . 
   Upon mounting the cap  13 B, the locking arm  13   d  of the cap  13 B is engaged with the locking projection  11   e  of the tubular neck portion  11   a  while engaging the inner circumferential surface  13   a  of the cap  13 B with the outer circumferential surface  11   c  of the tubular neck portion  11   a  of the container body  11 B, whereby the discharging hole  12   c  of the nozzle  12  is forcibly widened by the projection  13   e  of the cap  13 B to hermetically seal the discharging hole  12   c . It should be noted that the discharging hole  12   c  of the nozzle  12  is elastically deformed when the projection  13   e  of the cap  13 B is fitted into the discharging hole  12   c  of the nozzle  12  while forcibly widening it, and this deformed section is shown by crosshatching c. 
   Conversely, the cap  13 B can be loosened by being twisted by about 90° in a direction opposite from the one in which the cap  13 B is turned upon being attached to the nozzle  12  and then can be detached. 
   The nozzle  12  can be commonly used for the liquid container  10 A of the screw cap type shown in  FIG. 1  and the liquid container  10 B of the twist cap type shown in  FIG. 2 , including a liquid container  10 B′ of the twist cap type shown in  FIG. 12  to be described later. 
     FIGS. 4A ,  4 B,  4 C and  4 D are a front view, a section, a plan view and a bottom view showing one example of the nozzle  12 . An about one-third upper part of the upper portion  12   f  is formed into a slightly flat semispherical shape, and a ring-shaped projection  12   h  to be hermetically brought into contact with the inner circumferential surface  13   a  of the cap  13 A,  13 B is integrally formed on the outer circumferential surface of a maximum-diameter section of this semispherical portion. 
   Although this ring-shaped projection  12   h  has a substantially trapezoidal cross section, the shape, size and the like thereof do not particularly matter provided that a hermetic state can be established between the nozzle  12  and the cap  13 A,  13 B. However, in order to improve operability and durability, for example, by reducing a resistance during the attachment and detachment of the cap  13 A,  13 B, the ring-shaped projection  12   h  may be suitably formed with a tapered portion  12   m  or a chamfered portion if necessary. 
   In  FIGS. 1 and 2 , the ring-shaped projection  12   h  of the nozzle  12  is elastically deformed when being hermetically brought into contact with the circumferential surface  13   a  of the cap  13  and this deformed section is shown by crosshatching d. 
   A about two-third lower part of the upper portion  12   f  of the nozzle  12  is so largely scooped out as to be gradually narrowed from a position below the ring-shaped projection  12   h  and then gradually thickened toward the flange portion  12   g . Thus, a largely constricted portion  12   i  is integrally formed below the ring-shaped projection  12   h , i.e., between the ring-shaped projection  12   h  and the flange portion  12   g.    
   Further, at least two ring-shaped fins  12   e  are formed on the outer circumferential surface  12   b  of the lower portion  12   a  of the nozzle  12  while being vertically spaced apart. These ring-shaped fins  12   e  are different from a multitude of (at least three) ring-shaped fins disclosed in Japanese Unexamined Patent Publication No. 9-156662 and vertically spaced at specified intervals. Specifically, the middle ring-shaped fin is deleted from those disclosed in this publication, thereby forming an airtight air pool  12   j  wider than the one of the above prior art ring-shaped fins by one interval when the nozzle  12  is so hermetically inserted that the outer circumferential surface  12   b  of the lower portion  12   a  of the nozzle  12  is brought into contact with the inner circumferential surface  11   b  of the tubular neck portion  11   a  of the container body  11 . 
   Further, as shown in  FIGS. 1 and 2 , when the inner circumferential surface  13   a  of the cap  13 A,  13 B hermetically touches the ring-shaped projection  12   h  of the nozzle  12  upon mounting the cap  13 A,  13 B, an airtight air pool  13   g  is formed between a hermetically sealed portion of the cap  13 A,  13 B and the nozzle  12 , i.e., a hermetically sealed portion of the inner top surface  13   c  of the cap  13 A and the top surface  12   d  of the discharging hole  12   c  of the nozzle  12  in  FIG. 1  or a hermetically sealed portion of the projection  13   e  of the cap  13 B and the discharging hole  12   c  of the nozzle  12  in  FIG. 2 , and a hermetic contact portion of the inner circumferential surface  13   a  of the cap  13 A,  13 B and the ring-shaped projection  12   h  of the nozzle  12 . 
   The functions of the nozzle  12  of the liquid container  10 A,  10 B thus constructed are described. 
   When the cap  13 A,  13 B is mounted on the liquid container  10 A,  10 B, the inner circumferential surface  13   a  of the cap  13 A,  13 B hermetically touches the ring-shaped projection  12   h  of the nozzle  12 . Thus, sealing is doubly provided in cooperation of the hermetic sealing between the inner top surface  13   c  of the cap  13 A and the top surface  12   d  of the discharging hole  12   c  of the nozzle  12  in the liquid container  10 A of  FIG. 1 , or the hermetic sealing between the projection  13   e  of the cap  13 B and the discharging hole  12   c  of the nozzle  12  in the liquid container  10 B of  FIG. 2 . Therefore, a liquid leak can be securely prevented. 
   Further, the airtight air pool  13   g  is formed between the hermetically sealed portion of the cap  13 A,  13 B and the nozzle  12 , i.e., the hermetically sealed portion of the inner top surface  13   c  of the cap  13 A and the top surface  12   d  of the discharging hole  12   c  of the nozzle  12  in  FIG. 1  or the hermetically sealed portion of the projection  13   e  of the cap  13 B and the discharging hole  12   c  of the nozzle  12  in  FIG. 2 , and the hermetic contact portion of the inner circumferential surface  13   a  of the cap  13 A,  13 B and the ring-shaped projection  12   h  of the nozzle  12 . Thus, a liquid leak from the discharging hole  12   c  of the nozzle  12  can be more securely prevented by the action of an air pressure in this air pool  13   g.    
   Since the ring-shaped fins  12   e  whose edge are elastically deformed during the insertion of the nozzle  12  to hermetically touch the inner circumferential surface  11   b  of the tubular neck portion  11   a  of the container body  11  are formed on the outer circumferential surface  12   b  of the lower portion  12   a  of the nozzle  12 , the outer circumferential surface  12   b  of the lower surface  12   a  of the nozzle  12  and the inner circumferential surface  11   b  of the tubular neck portion  11   a  are attached to a higher degree by the elastic deformation of the ring-shaped fins  12   e  and an occurrence of a crack in the tubular neck portion  11   a  due to a dimensional error of the tubular neck portion  11   a  and the nozzle  12  can be prevented. 
   Further, since the airtight air pool  12   j  is formed between the hermetic contact portions of the respective ring-shaped fins  12   e  and the inner circumferential surface  11   b  of the tubular neck portion  11   a , a liquid leak through a clearance between the tubular neck portion  11   a  of the container body  11  and the nozzle  12  can be securely prevented by the action of an air pressure in this air pool  12   j.    
   On the other hand, the content liquid “a” can be caused to drip from the discharging hole  12   c  of the nozzle  12  by pressing the container body  11  by fingers with the nozzle  12  faced substantially right down for dripping as shown in  FIG. 11A  after the cap  13 A,  13 B is detached. 
   In the case that the nozzle  12  is inclined to face obliquely downward as shown in  FIG. 11B  before the content liquid “a” is caused to drip from the discharging hole  12   c  of the nozzle  12 , the content liquid “a” comes out of the discharging hole  12   c  and runs down to the upper portion  12   f  of the nozzle  12 . 
   As shown in  FIG. 11C , if the nozzle  12  is further inclined to face obliquely upward from this state, the content liquid “a” cannot be easily caused to drip since it runs down to the tubular neck portion  11   a  of the container body  10 A,  10 B from the upper portion  12   f  or cannot be formed well into drops. In such a case, since the ring-shaped projection  12   h  serves as a barrier wall for damming up the content liquid “a” trying to run down, a liquid leak can be securely prevented. In other words, the ring-shaped projection  12   h  has a barrier-wall function to prevent the liquid leak. 
   The higher the barrier wall by the ring-shaped projection  12   h , the better the barrier wall effect. Thus, the liquid leak can be more effectively prevented by making the barrier wall by the ring-shaped projection  12   h  higher by forming the constricted portion  12   i  below the ring-shaped projection  12   h  of the nozzle  12 . 
   Further, since the ring-shaped projection  12   h  functions as a core for forming liquid drops from the dammed-up content liquid “a” by the surface tension, the content liquid “a” drips better as a result. Further, drops can be easily formed not only when the nozzle  12  is faced substantially right down, but also when the nozzle  12  is horizontally held or inclined to face obliquely downward. In other words, liquid drops can be easily formed independently of a dripping angle. Thus, the content liquid “a” can be caused to drip via the ring-shaped projection  12   h  of the nozzle  12 . In other words, the ring-shaped projection  12   h  also has a core function for forming the liquid drops. 
   The nozzle  12  shown in  FIGS. 4A to 4D  is formed such that the about one-third upper part of the upper portion  12   f  is formed into a slightly flat semispherical shape, and the about two-third lower part thereof is largely curved inward to be first thinned from the position below the ring-shaped projection  12   h  and then gradually thickened toward the flange portion  12   g , thereby integrally forming the largely constricted portion  12   i  below the ring-shaped projection  12   h , i.e., between the ring-shaped projection  12   h  and the flange portion  12   g.    
   Contrary to this, as in a first modification shown in  FIGS. 5A and 5B , the about one-third upper part of the upper portion  12   f  of the nozzle  12  may be formed into a slightly flat semispherical shape, and the about two-third lower part thereof may have its upper section gradually thickened toward its upper end so that the upper end is continuous with a maximum-diameter portion of the semispherical portion and has its lower section gradually thickened toward its bottom end coupled to the flange portion  12   g , thereby a deep semispherical constricted portion  12   i  integrally formed between the ring-shaped projection  12   h  and the flange portion  12   g.    
   Further, as in a second modification shown in  FIGS. 6A and 6B , the about two-third upper part of the upper portion  12   f  of the nozzle  12  may be formed into a slightly flat spherical shape, and the about one-third lower part thereof may have its upper section gradually thinned toward its upper end so that its upper end is continuous with a minimum-diameter portion of the spherical portion and have its lower section gradually thickened toward its bottom end coupled to the flange portion  12   g , thereby integrally forming a constricted portion  12   i  below the ring-shaped projection  12   h , i.e., between the ring-shaped projection  12   h  and the flange portion  12   g.    
   In the first modification shown in  FIGS. 5A and 5B  and the second modification shown in  FIGS. 6A and 6B , three vertically spaced-apart ring-shaped fins  12   e  are formed on the outer circumferential surface  12   b  of the lower portion  12   a  of the nozzle  12 , and a wide airtight air pool  12   j  is formed by widening the interval between the two upper ring-shaped fins  12   e . However, as shown in  FIGS. 7A and 7B , two vertically spaced-apart ring-shaped fins  12   e  may be formed similar to the nozzle  12  of  FIGS. 4A to 4D  and a wide airtight air pool  12   j  may be formed by widening the interval between these two ring-shaped fins  12   e.    
   Further, as in a fourth modification shown in  FIGS. 8A and 8B , the about one-third upper part of the upper portion  12   f  of the nozzle  12  may be formed into a slightly flat semispherical shape, the about two-third lower part thereof may be almost entirely made as thick as a maximum-diameter portion of the semispherical portion up to the flange portion  12   g , and a shallow semispherical constricted portion  12   i  may be integrally formed between the ring-shaped projection  12   h  and the flange portion  12   g.    
   Furthermore, as in a fifth modification shown in  FIGS. 9A and 9B , the about one-third upper part of the upper portion  12   f  of the nozzle  12  may be formed into a slightly flat semispherical shape, and the about two-third lower part thereof may be almost entirely made as thick as a maximum-diameter portion of the semispherical portion up to the flange portion  12   g . What the fifth modification differs from the other modifications is that no constricted portion  12   i  is integrally formed between the ring-shaped projection  12   h  and the flange portion  12   g . Even if no constricted portion  12   i  is formed, double sealing is provided as described above by hermetically brining the inner circumferential surface  13   a  of the cap  13  into contact with the ring-shaped projection  12   h . Thus, this modification also has an effect of securely preventing a liquid leak. 
   Further, as in a sixth modification shown in  FIGS. 10A and 10B , the lower portion  12   a  of the nozzle  12  may be formed straight without forming the ring-shaped fins  12   e  on the outer circumferential surfaces  12   b  thereof. The lower portion  12   a  may be undetachably fixed to the tubular neck portion  11   a  by a known fusing method with the outer circumferential surface  12   b  thereof hermetically held in contact with the inner circumferential surface  11   b  of the tubular neck portion  11   a.    
   Although the nozzle  12  shown in  FIGS. 1 and 2  is of the type that is hermetically inserted into the tubular neck portion  11   a  of the container body  11 A,  11 B, the nozzle structure of this embodiment is also applicable to a liquid container  10 C of the hinged cap type in which a nozzle  12 ′ is integrally formed with a cap  13 C as shown in  FIGS. 3A and 3B . 
   Specifically, the container body  11 C of the liquid container  10 C of the hinged cap type is integrally formed with a large-diameter tubular neck portion  11   a  at its upper part, and an external thread  11   d  is integrally formed on an outer circumferential surface  11   c  of the tubular neck portion  11   a.    
   The cap  13 C has an internal thread  13   b  integrally formed in an inner circumferential surface  13   a  of a large-diameter portion  13   i , and the nozzle  12 ′ is integrally formed on a top portion  13   k . A discharging hole  12   c  is formed in a top surface  12   d  of the nozzle  12 ′. 
   An upper lid  13   p  is integrally coupled to a side of the top portion  13   k  of the cap  13 C via a hinge  13   q . It should be noted that the top portion  13   k  and the upper lid  13   p  are doubly coupled by a larger hinge  13   r  for reinforcement. 
   A projection  13   e  fittable into the discharging hole  12   c  of the nozzle  12 ′ while forcibly widening the discharging hole  12   c  and a tubular portion  13   s  having an inner circumferential surface  13   a  to be fitted on an outer circumferential surface  12   b  of the nozzle  12 ′ are integrally formed on an inner top surface  13   c  of the upper lid  13   p.    
   The cap  13 C is hermetically mounted by engaging the internal thread  13   b  of the cap  13 C with the external thread  11   d  of the tubular neck portion  11   a  of the container body  11 C. Since it is not necessary to detach the cap  13 C from the container body  11 C in this embodiment, the cap  13 C may be undetachably fixed by a known fusing method after being mounted on the container body  11 C instead of being fixed by the engagement of the external and internal threads. 
   When the upper lid  13   p  is closed using the hinges  13   q ,  13   r  thereafter (see  FIG. 3A ), the projection  13   e  is fitted into the discharging hole  12   c  of the nozzle  12 ′ while forcibly widening it, whereby the discharging hole  12   c  can be hermetically sealed. 
   Conversely, when the upper lid  13   p  is opened using the hinges  13   q ,  13   r  (see  FIG. 3B ), the projection  13   e  comes out of the discharging hole  12   c  of the nozzle  12 ′ to open the discharging hole  12   c.    
   The material of this nozzle  12 ′ is not particularly restricted provided that it is a synthetic resin suitable for molding the cap  13 C including the hinges  13   q ,  13   r . It is preferable to form the nozzle  12 ′ of a so-called soft synthetic resin. Among soft synthetic resins, a polypropylene (PP) is more preferably used. Further, an antibacterial treatment may be suitably applied if necessary. A molding method for the hinged cap  13 C is not particularly restricted since the preferable method differs depending on the synthetic resin to be used. However, it is preferable to mold the cap  13 C by injection molding and extrusion molding. 
   Basically similar to the nozzle  12  of  FIGS. 1 and 2 , the nozzle  12 ′ is such that an about one-third upper part of an upper portion  12   f  is formed into a slightly flat semispherical shape and an about two-third lower part thereof is largely curved inward to be gradually thinned from a position below a ring-shaped projection  12   h  and then to be gradually thinned toward its bottom end coupled to the top portion  13   k , thereby integrally forming a largely constricted portion  12   i  below the ring-shaped projection  12   h , i.e., between the ring-shaped projection  12   h  and the top portion  13   k.    
   The functions of the nozzle  12 ′ of the liquid container constructed as above are described. 
   When the upper lid  13   p  of the cap  13 C of the liquid container  10 C is closed, the inner circumferential surface  13   a  of the tubular portion  13   s  of the cap  13 C is hermetically brought into contact with the ring-shaped projection  12   h  of the nozzle  12 ′. Thus, sealing is doubly provided in cooperation with the hermetic sealing of the discharging hole  12   c  by the projection  13   e  fitted into the discharging hole  12   c  of the nozzle  12 ′ while forcibly widening it. Therefore, a liquid leak can be securely prevented. 
   Further, an airtight air pool  13   g  is formed in the hermetically sealed portion between the cap  13 C and the nozzle  12 ′, i.e., between the hermetically sealed portion of the projection  13   e  of the cap  13 C and the discharging hole  12   c  of the nozzle  12 ′ and the hermetic contact portion of the inner circumferential surface  13   a  of the tubular portion  13   s  of the cap  13 C and the ring-shaped projection  12   h  of the nozzle  12 ′. Thus, a liquid leak from the discharging hole  12   c  of the nozzle  12  can be more securely prevented by the action of an air pressure in this air pool  13   g.    
   It should be noted that no description is given here on the functions and effects when the upper lid  13   p  is opened to cause the content liquid “a” to drip from the discharging hole  12   c  of the nozzle  12 ′ since they are the same as those described with reference to  FIGS. 11A to 11C . 
   In the liquid container  10 B of the twist cap type shown in  FIG. 2 , the ring-shaped projection  12   h  of the nozzle  12  is hermetically brought into contact with the inner circumferential surface  13   a  of the cap  13 B when the cap  13 B is mounted, thereby forming an airtight air pool  13   g  between the hermetically sealed portion of the projection  13   e  of the cap  13 B and the discharging hole  12   c  of the nozzle  12  and the hermetic contact portion of the inner circumferential surface  13   a  of the cap  13 B and the ring-shaped projection  12   h  of the nozzle  12 . 
   In a liquid container  10 B′ of the twist cap type shown in  FIGS. 12A and 12B , an inner circumferential surface  13   a  of a cap  13 B′ is located more outward and a plurality of (four in this example) fins  13   m  radially projecting inward while being circumferentially spaced at even intervals are formed on the inner circumferential surface  13   a  of the cap  13 B′ instead of hermetically brining the inner circumferential surface  13   a  into contact with the ring-shaped projection  12   h  of the nozzle  12 , and the inner ends of these fins  13   m  are held in contact with the ring-shaped projection  12   h  of the nozzle  12 . It should be noted that the inner ends of the fins  12   m  need not always be in contact with the ring-shaped projection  12   h  of the nozzle  12 . These fins  13   m  are formed to center the nozzle  12 . 
   Accordingly, the inner circumferential surface  13   a  of the cap  13 B′ and the ring-shaped projection  12   h  of the nozzle  12  are not hermetically held in contact in this liquid container  10 B′ of the twist cap type. Thus, no airtight air pool  13   g  is formed. 
   However, even such a liquid container  10 B′ of the twist cap type can enjoy the functions and effects brought about by the ring-shaped fins  12   e  of the nozzle  12  and those brought about by the ring-shaped projection  12   h  by the nozzle  12  similar to the liquid container  10 B of the twist cap type shown in  FIG. 2 . 
   As described above, an inventive nozzle structure for a liquid container in which a nozzle is provided on the top of a tubular neck portion of a container body, a cap is mounted on the tubular neck portion, and a discharging hole of the nozzle is hermetically sealed by an inner top portion of the cap, wherein a ring-shaped projection is formed on an upper portion of the nozzle. 
   In this nozzle structure, the ring-shaped projection of the nozzle has both a barrier-wall function for preventing a liquid leak and a core function for forming liquid drops. 
   Specifically, if the ring-shaped projection is formed on the upper portion of the nozzle, a content liquid comes out of the discharging hole and runs toward the upper portion of the nozzle in the case that the nozzle is inclined to face obliquely downward while the content liquid is being caused to drip from the discharging hole of the nozzle with the nozzle faced substantially right down. If the nozzle is further inclined to face obliquely upward in this state, the content liquid is difficult to drip because it runs down to the tubular neck portion of the container body from the upper portion of the nozzle or cannot be formed well into liquid drops. In such a case, the liquid leak can be securely prevented since the ring-shaped projection serves as a barrier wall for damming up the content liquid trying to run down. 
   The higher the barrier wall, the better the effect. Thus, it is preferable to make the barrier wall formed by the ring-shaped projection higher by forming a constricted portion, for example, below the ring-shaped projection of the nozzle. 
   Further, since the ring-shaped projection functions as a core for forming the content liquid dammed up here into liquid drops by the surface tension, the content liquid drips better as a result. Further, drops can be easily formed not only when the nozzle is faced substantially right down, but also when the nozzle is horizontally held or inclined to face obliquely downward. In other words, drops can be easily formed independently of a dripping angle. Thus, the content liquid can be caused to drip via the ring-shaped projection of the nozzle. 
   The expression “the nozzle is provided on the top of the tubular neck portion of the container body” includes a case where the nozzle is integrally formed on the top of the tubular neck portion of the container body in addition to a case where the nozzle is hermetically inserted into the tubular neck portion and a case where the nozzle is formed on the top of the cap hermetically mounted on the tubular neck portion of the container body. 
   Further, the expression “the discharging hole is hermetically sealed by the inner top portion of the cap” means to hermetically seal the discharging hole by pressing the inner top surface of the cap against the top surface of the discharging hole in the liquid container of the screw cap type and to hermetically seal the discharging hole by inserting a projection on the inner top surface of the cap into the discharging hole while forcibly widening the discharging hole in the liquid container of the twist cap type. 
   Another inventive nozzle structure for a liquid container in which a nozzle is provided on the top of a tubular neck portion of a container body, a cap is detachably mounted on the tubular neck portion such that an inner circumferential surface of the cap is in contact with an outer circumferential surface of the tubular neck portion, and a discharging hole of the nozzle is hermetically sealed by an inner top portion of the cap, wherein a ring-shaped projection to be hermetically brought into contact with the inner circumferential surface of the cap is formed on an upper portion of the nozzle. 
   In this nozzle structure, the inner circumferential surface of the cap is hermetically in contact with the ring-shaped projection formed on the upper portion of the nozzle with the cap mounted. Thus, double sealing can be provided in cooperation with the hermetic sealing of the discharging hole of the nozzle by the inner top portion of the cap, with the result that the liquid leak can be more securely prevented. 
   In short, a hermetically sealed state is attained only by sealing the discharging hole of the nozzle by the inner top surface of the cap to prevent a liquid leak, and a higher precision control such as a higher assembling precision of the nozzle and the cap and a tightening torque are required in the prior art nozzle structure. However, since the hermetically sealed state can be structurally compensated for by forming a sealing portion by the ring-shaped projection, the liquid leak can be securely suppressed and precision conditions such as an assembling precision of the nozzle and the cap and a tightening torque can be alleviated. There is an additional effect that a precision control is easy in a production process for products using liquid containers having these structures. 
   The ring-shaped projection has both a barrier-wall function for preventing a liquid leak and a core function for forming liquid drops. 
   Still another inventive nozzle structure for a liquid container in which a nozzle is inserted into a tubular neck portion of a container body such that an outer circumferential surface of a lower portion of the nozzle is hermetically held in contact with an inner circumferential surface of the tubular neck portion, a cap is detachably mounted on the tubular neck portion such that an inner circumferential surface of the cap is spirally engaged with or locked into an outer circumferential surface of the tubular neck portion, and a discharging hole of the nozzle is hermetically sealed by an inner top portion of the cap, wherein a ring-shaped projection to be hermetically brought into contact with the inner circumferential surface of the cap is formed on an upper portion of the nozzle. 
   In this nozzle structure, the inner circumferential surface of the cap is hermetically brought into contact with the ring-shaped projection formed on the upper portion of the nozzle when the cap is mounted by being spirally engaged with or locked into the tubular neck portion. Thus, double sealing can be provided in cooperation with the hermetic sealing of the discharging hole of the nozzle by the inner top portion of the cap, with the result that the liquid leak can be more securely prevented. 
   The ring-shaped projection has both a barrier-wall function for preventing a liquid leak and a core function for forming liquid drops. 
   Further another inventive nozzle structure for a liquid container in which a nozzle is formed on the top of a cap hermetically mounted on a tubular neck portion of a container body, an upper lid is coupled to the cap via a hinge, and a discharging hole of the nozzle is hermetically sealed by an inner top portion of the upper lid, wherein a ring-shaped projection to be hermetically brought into contact with the inner circumferential surface of the cap is formed on an upper portion of the nozzle. 
   In this nozzle structure, the inner circumferential surface of the upper lid is hermetically brought into contact with the ring-shaped projection formed on the upper portion of the nozzle when the upper lid is mounted on the nozzle of the cap. Thus, double sealing can be provided in cooperation with the hermetic sealing of the discharging hole of the nozzle by the inner top portion of the upper lid, with the result that the liquid leak can be more securely prevented. 
   The ring-shaped projection has both a barrier-wall function for preventing a liquid leak and a core function for forming liquid drops. 
   The expression “the cap is hermetically mounted on the tubular neck portion of the container body” includes a case where the cap is undetachably fixed by a known melting method after being hermetically engaged with the tubular neck portion in addition to a case where the cap is spirally engaged with the tubular neck portion. 
   Preferably, an airtight air pool is formed between a hermetically sealed portion of the inner top portion of the cap and the discharging hole of the nozzle and a hermetic contact portion of the inner circumferential surface of the cap and the ring-shaped projection of the nozzle. Then, the liquid leak from the discharging hole of the nozzle can be more securely prevented by the action of an air pressure in this air pool. 
   Further, a constricted portion is preferably formed below the ring-shaped projection of the nozzle. Then, the content liquid collected at the ring-shaped projection by the surface tension is made unlikely to run down by the constricted portion. Therefore, the liquid dripping from the nozzle can be more securely prevented, with the result that the liquid drops can be more easily formed. 
   Preferably, at least two ring-shaped fins whose edges are to be hermetically brought into contact with the inner circumferential surface of the tubular neck portion upon inserting the nozzle into the tubular neck portion are formed on the outer circumferential surface of the lower portion of the nozzle while being vertical spaced apart, and an airtight air pool is formed between hermetic contact portions of the respective ring-shaped fins and the inner circumferential surface of the tubular neck portion. Then, the liquid leak through a clearance between the tubular neck portion of the container body and the nozzle can be more securely prevented by the action of an air pressure in this air pool. 
   This application is based on patent application Nos. 2002-308504 and 2003-67739 filed in Japan, the contents of which are hereby incorporated by references. 
   As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to embraced by the claims.