Patent Description:
As examples of a container having such container spout portion, there can be cited resin made containers such as a preform, a bottle container manufactured with using the preform, etc..

When a plurality of such resin made containers are accommodated in a container or the like for their transportation therein, due to hitting between the resin made containers, a dent damage may be generated/formed at the spout portion of the resin made container. If a cap is fitted on the spout portion with such dent damage in the resin made container, the seal portion of the cap may be damaged by the dent damage of the spout portion, so that there is a risk of leaking of contents filled in the resin made container through the damaged portion of the seal portion.

In view of the above-described situation, a resin made container has been manufactured and sold in Europe since the year <NUM> which is designed to attempt prevention of reduction in the sealing performance of the container spout portion through reduction of occurrence of dent damage at the spout portion of a preform therefor. To this end, in this preform, as disclosed in e.g. <CIT>, at the container spout portion, a chamfered portion is formed between a top face and an inner circumferential face of the preform.

<CIT> discloses a resin container having a tip face of a cylinder and a sealing face being connected to each other by a circular protruding face. The protruding face comprises a first curve having a radius of curvature, a second curve having a radius of curvature coupling the first curve to the sealing face and a third curve having a radius of curvature coupling the first curve and the tip face (Ra>>Rb>Rc). The first curve is placed so that its virtual extension face crosses respective virtual extension faces of the tip face and the sealing face. The second curve is formed of an arc face inscribing the sealing face and the first curve. The third curve is formed of an arc face inscribing the tip face and the first curve. <CIT> discloses a beaker shaped plastic component produced by injection molding, which is expanded to a plastic bottle using a blowing process. The component comprises a mouth section with a thread, an edge and an inwardly rounded section. The inner rounded section extends over more than <NUM>% of the wall thickness. The rounded section consists of a flat region which is at an acute angle to the horizontal. The curves have a radius of <NUM>-<NUM>.

However, with the configuration of the conventional container spout portion, a dent may be formed at a lower portion of the chamfered portion. If this happens, reduction in the sealing performance of the container spout portion will occur. Thus, there remains room for improvement. Therefore, the object of the present invention is to provide a spout portion configuration that can effectively resist formation/generation of a dent damage therein at the time of e.g. transport, thus being capable of preventing reduction in the sealing performance of the container spout portion.

According to a characterizing feature of a container spout portion relating to the present invention, there is provided a container spout portion included in a container body and configured to be sealed as a seal portion comes into contact with an inner circumferential face in association of attachment thereto of a cap having the seal portion therein;
wherein.

According to the present invention, the arcuate portion has a curvature radius equal to or less than <NUM>.

According to a still further characterizing feature of the container spout portion relating to the present invention, a distance from the joining point between the arcuate portion and the top face or the crossing point between the virtual extension line of the arcuate portion and either the top face or the virtual extension line of the top face to a virtual extension line of the inner circumferential face ranges from <NUM> to <NUM>.

According to a still further characterizing feature of the container spout portion relating to the present invention, a distance from a joining portion between the arcuate portion and the inner circumferential face or a crossing point between the virtual extension line of the arcuate portion and either the inner circumferential face or the virtual extension line of the inner circumferential face to the virtual extension line of the top face ranges from <NUM> to <NUM>.

According to a still further characterizing feature of the container spout portion relating to the present invention, between the arcuate portion and the top face and between the arcuate portion and the inner circumferential face, there are formed further arcuate portions each having a smaller curvature radius than the arcuate portion.

With the present invention: an arcuate portion convex inwards is formed between a top face and the inner circumferential face of the container spout portion; a tangential line to the arcuate portion starts from either a joining point between the arcuate portion and the top face or from a crossing point between a virtual extension line of the arcuate portion and the top face or a virtual extension line of the top face; and an angle formed between the top face and the tangential line ranges from <NUM> to <NUM> degrees. With these arrangements, the joining point between the arcuate portion and the inner circumferential face can be provided at a lower position. As a result, possibility of formation or generation of a dent damage affecting the sealing performance of the container spout portion at this joining portion between the arcuate portion and the inner circumferential face can be reduced. Moreover, in particular, in case further arcuate portions each having a smaller curvature radius than the arcuate portion are formed between the arcuate portion and the top face as well as between the arcuate portion and the inner circumferential face, the joining point between the arcuate portion and the inner circumferential face can be provided at an even lower position. As a result, possibility of formation or generation of a dent damage at the joining portion between the arcuate portion and the inner circumferential face can be further reduced. Consequently, the reduction in the sealing performance of the container spout portion can be prevented.

Next, an embodiment of a container spout portion relating to the present invention will be explained with reference to the accompanying drawings. Here, there will be explained an exemplary case wherein the inventive container spout portion is applied to a resin made bottle container.

As shown in <FIG>, a bottle container <NUM> relating to this embodiment includes a container body <NUM> having a bottomed cylindrical shape and a cylindrical container spout portion <NUM> provided at the leading end of the container body <NUM> integrally therewith. The container spout portion <NUM> is arranged to be fitted with a cap <NUM> thereon.

As shown in <FIG> and <FIG>, the cap <NUM> used in this embodiment includes a top plate portion <NUM>, a tubular portion <NUM> extending downwards from the circumferential edge of the top plate portion <NUM> and having threads <NUM> in its inner circumferential face, an outer ring <NUM> formed on the inner face of the top plate portion <NUM> and coming into contact with an outer circumferential face <NUM> of the container spout portion <NUM>, and an inner ring <NUM> (an example of "seal portion") formed on the inner face of the top plate portion <NUM> and coming into contact with an inner circumferential face <NUM> of the container spout portion <NUM>. The cap <NUM> applicable in this invention is not limited to the one having the above-described configuration. Instead, a known standard cap having a seal portion capable of sealing by coming into contact with the inner circumferential face of the container spout portion may be used also.

The outer ring <NUM> and the inner ring <NUM> each has a shape protruding from the inner face of the top plate portion <NUM>. In the instant embodiment, the length of the inner ring <NUM> (the vertical distance from the top plate portion <NUM>) is longer than that of the outer ring <NUM>. As the outer ring <NUM> and the outer circumferential face <NUM> of the container spout portion <NUM> come into contact with each other and also the inner ring <NUM> and the inner circumferential face <NUM> of the container spout portion <NUM> come into contact with each other, the bottle container <NUM> is sealed.

The material and the manufacturing method of the cap <NUM> are not particularly limited. For instance, the cap <NUM> may be manufactured by integrally molding by a known molding technique the top plate portion <NUM>, the tubular portion <NUM>, the outer ring <NUM> and the inner ring <NUM> with using resin such as polyethylene, polypropylene, polystyrene, etc..

As shown in <FIG>, the container body <NUM> includes a shoulder portion <NUM> formed continuous with the container spout portion <NUM>, a body portion <NUM> continuous with the shoulder portion <NUM>, and a bottom portion <NUM> continuous with the body portion <NUM> and located at the lowest part.

The bottle container <NUM> in this embodiment is a container made of resin such as polyethyleneterephthalate (PET), polyethylene, polypropylene, etc. In this bottle container <NUM>, with use of a preform having the container spout portion <NUM> molded by e.g. the injection molding technique, the container body <NUM> is molded by the blow molding technique, thus forming the container body <NUM> and the container spout portion <NUM> integral with each other. Such bottle container <NUM> can be used as a beverage container for water, carbonated beverage or the like, a food container for e.g. sauce or the like, etc..

As shown in <FIG> and <FIG>, the container spout portion <NUM> includes a top face <NUM>, the inner circumferential face <NUM> and the outer circumferential face <NUM>. In the outer circumferential face <NUM> of the container spout portion <NUM>, threads <NUM> are provided. These threads <NUM> of the container spout portion <NUM> can be meshed with the threads <NUM> of the cap <NUM> and the cap <NUM> can be attached/detached to/from the container spout portion <NUM>. Further, an arrangement is provided such that with fitting of the cap <NUM> on the container spout portion <NUM>, the outer ring <NUM> comes into contact with the outer circumferential face <NUM> of the container spout portion <NUM> and also the inner ring <NUM> comes into contact with the inner circumferential face <NUM> of the container spout portion <NUM>.

As shown in <FIG>, an arcuate portion <NUM> formed convex toward the inner side of the container is formed between the top face <NUM> and the inner circumferential face <NUM> of the container spout portion <NUM>. Further, a second arcuate portion <NUM> formed convex toward the inner side of the container is formed between the arcuate portion <NUM> and the top face <NUM>, and a third arcuate portion <NUM> formed convex toward the inner side of the container is formed between the arcuate portion <NUM> and the inner circumferential face <NUM>. Namely, in the container spout portion <NUM> relating to the instant embodiment, three arcuate portions, i.e. the second arcuate portion <NUM>, the arcuate portion <NUM> and the third arcuate portion <NUM> are formed continuously from the top face <NUM> to the inner circumferential face <NUM>. Incidentally, the second arcuate portion <NUM> and the third arcuate portion <NUM> correspond to "further arcuate portions" in this invention, and the curvature radius of the second arcuate portion <NUM> and the third arcuate portion <NUM> respectively is smaller than that of the arcuate portion <NUM>.

A tangential line T to the arcuate portion <NUM> starts from a crossing point A2 between a virtual extension line E1 of the arcuate portion <NUM> and the top face <NUM> or a virtual extension line E3 of this top face <NUM>. And, an angle θ formed between the top face <NUM> and the tangential line T ranges preferably from <NUM> to <NUM> degrees, more preferably from <NUM> to <NUM> degrees. Incidentally, the tangential line T in this embodiment starts at a crossing point A2 between the virtual extension line E1 of the arcuate portion <NUM> and the virtual extension line E3 of the top face <NUM> and its angle θ is set to <NUM> degrees.

The curvature radius of the arcuate portion <NUM> is equal to or less than <NUM>, preferably from <NUM> to <NUM>, more preferably from <NUM> to <NUM>. The curvature radius of the arcuate portion <NUM> in this embodiment is set to <NUM>.

The curvature radius of the second arcuate portion <NUM> and the third arcuate portion <NUM> respectively ranges preferably from <NUM> to <NUM>. Incidentally, in this embodiment, the respective curvature radii of the second arcuate portion <NUM> and the third arcuate portion <NUM> are set identically to <NUM>.

A distance D from the crossing point A2 between the virtual extension line E1 of the arcuate portion <NUM> and the top face <NUM> or the virtual extension line E3 of this top face <NUM> (in this embodiment, this is set as the crossing point between the virtual extension line E1 of the arcuate portion <NUM> and the virtual extension line E3 of the top face <NUM>) to the virtual extension line E2 of the inner circumferential face <NUM> ranges preferably from <NUM> to <NUM>, more preferably from <NUM> to <NUM>, most preferably from <NUM> to <NUM>. The distance D in this embodiment is set to <NUM>.

A distance H from a crossing point B2 between the virtual extension line E1 of the arcuate portion <NUM> and the inner circumferential face <NUM> or the virtual extension line E2 of this inner circumferential face <NUM> (in this embodiment, this is set as the crossing point between the virtual extension line E1 of the arcuate portion <NUM> and the virtual extension line E2 of this inner circumferential face <NUM>) to the virtual extension line E3 of the top face <NUM> ranges preferably from <NUM> to <NUM>, more preferably from <NUM> to <NUM>, most preferably from <NUM> to <NUM>. The distance H in this embodiment is set to <NUM>.

In the foregoing embodiment, the second arcuate portion <NUM> and the third arcuate portion <NUM> are provided. However, the invention is not limited thereto. Alternatively, the second arcuate portion <NUM> and the third arcuate portion <NUM> may be omitted. In such case, the tangential line T to the arcuate portion <NUM> will start from the joining point A1 between the arcuate portion <NUM> and the top face <NUM>. And, the angle θ between the top face <NUM> and the tangential line T will range preferably from <NUM> to <NUM> degrees, more preferably from <NUM> to <NUM> degrees (see <FIG>). Further, the distance D from the joining potion A1 between the arcuate portion <NUM> and the top face <NUM> to the virtual extension line E2 of the inner circumferential face <NUM> will range preferably from <NUM> to <NUM>. And, the distance H from a joining potion B1 between the arcuate portion <NUM> and the inner circumferential face <NUM> to the virtual extension line E3 of the top face <NUM> will range preferably from <NUM> to <NUM>. <NUM> (see <FIG>).

In the foregoing embodiment, there was disclosed a case in which the inventive container spout portion is applied to a resin made bottle container. However, the invention is not limited thereto. Alternatively, for instance, the invention may be applied to a bottomed cylindrical preform P or the like having one side thereof opened, as shown in <FIG>. Or, the invention may also be applied to a container made of material other than resin.

Shape comparisons were made due to difference in the curvature radius of the arcuate portion <NUM> in the container spout portion <NUM>.

In an example shown in <FIG>, the curvature radius of the arcuate portion <NUM> was set to <NUM>. In an example shown in <FIG>, the curvature radius of the arcuate portion <NUM> was set to <NUM>.

In these two examples shown respectively in <FIG>, no further (other) arcuate portions than the arcuate portion <NUM> were provided. And, the angle between the top face <NUM> and the tangential line T was <NUM> degree in both examples. Further, the distance D from the joining point A1 between the arcuate portion <NUM> and the top face <NUM> to the virtual extension line E2 of the inner circumferential face <NUM> was set identical in both the examples.

In the above, a distance H1 from the joining point B1 between the arcuate portion <NUM> and the inner circumferential face <NUM> to the virtual extension line E3 of the top face <NUM> in the example of <FIG> was longer than a distance H2 from the joining point B1 between the arcuate portion <NUM> and the inner circumferential face <NUM> to the virtual extension line E3 of the top face <NUM> in the example of <FIG> (H1>H2). Namely, it was found that even when the angle of the tangential line T remains same, decrease in the curvature radius of the arcuate portion <NUM> results in lowering of the position of the joining point B1 between the arcuate portion <NUM> and the inner circumferential face <NUM>,.

Next, <NUM> (ten) units of preforms (forming material: PET, weight: <NUM>) having the container spout portion relating to the foregoing embodiment were made, with the curvature radius of the arcuate portion <NUM> being <NUM>, the respective curvature radii of the second arcuate portion <NUM> and the third arcuate portion <NUM> being both <NUM>, the angle between the top face <NUM> and the tangential line T being <NUM> degrees. Then, evaluation tests which simulated collision between the preforms at the time of transportation were made.

On these ten units of preforms, collision tests were conducted to check whether any damage was formed in each container spout portion. The result was that eight out of the ten units had no damage. Although dent damages were confirmed in the remaining two units, no dent damages were found therein at the joining point between the arcuate portion and the inner circumferential face. On the other hand, when similar tests were conducted on ten units of preforms having conventional spout portions having no chamfering, the result was that dent damages were confirmed in all the ten units. Therefore, it was confirmed that with the inventive container spout portion, generation/formation of dent damage in the container spout portion, in particular, such dent damage at the joining point between the arcuate portion and the inner circumferential face can be reduced effectively.

Claim 1:
A container spout portion (<NUM>) included in a container body (<NUM>) or in a container preform, and configured to be sealed as a seal portion (<NUM>) comes into contact with an inner circumferential face (<NUM>) in association of attachment thereto of a cap (<NUM>) having the seal portion (<NUM>) therein;
wherein:
the container spout portion (<NUM>) includes an outer circumferential face (<NUM>) provided with a thread (<NUM>), characterized in that
an arcuate portion (<NUM>) convex inwards and having a curvature radius equal to or less than <NUM> is formed between a top face (<NUM>) and the inner circumferential face (<NUM>) of the container spout portion (<NUM>);
a tangential line (T) to the arcuate portion (<NUM>) starts from either a joining point (A1) between the arcuate portion (<NUM>) and the top face (<NUM>) or from a crossing point (A2) between a virtual extension line (E1) of the arcuate portion (<NUM>) and the top face (<NUM>) or a virtual extension line (E3) of the top face (<NUM>); and
an angle (θ) formed between the top face (<NUM>) and the tangential line (T) ranges from <NUM> to <NUM> degrees.