JP3977911B2 - Plastic cap - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin cap that is applied to a glass or synthetic resin container in which contents such as liquid are accommodated without being pressurized or depressurized, and particularly to a milk bottle in which milk is accommodated. The present invention relates to a synthetic resin cap to be applied.
[0002]
[Prior art]
As a conventional example of a synthetic resin cap applied to a container in which contents such as liquid are accommodated, for example, one disclosed in Japanese Utility Model Publication No. 47-13109 can be cited. The synthetic resin cap disclosed in the above publication includes a top wall and a skirt wall extending downward from the periphery of the top wall. An inner plug portion (concave portion) protruding downward is formed at the center of the top wall. The inner plug portion includes an annular side wall depending from the center of the top wall and a bottom wall that closes the lower end of the side wall, and the upper surface of the side wall and the inner peripheral surface of the bottom wall form part of the upper surface of the top wall. The outer peripheral surface of the side wall of the inner plug portion formed as described above forms an annular seal protrusion (inner seal) that is fitted to the inner peripheral surface of the container opening. On the inner peripheral surface of the skirt wall, there are formed locking ridges (thick ridges and thick ridges) that are locked to an annular locked jaw formed on the outer peripheral surface of the container opening. ing. On the outer peripheral surface at the opening end of the skirt wall, a knob portion protruding radially outward is formed over a part in the circumferential direction. A thin portion (thin groove) that can be broken is formed at both edges in the circumferential direction of the knob portion of the skirt wall. The cap is stoppered so that the outer peripheral surface of the seal protrusion is fitted to the inner peripheral surface of the container opening and the locking protrusion is locked to the locked jaw portion formed on the outer peripheral surface of the container opening. And attached to the container opening. Further, when the cap is opened, the skirt wall is broken along the thin wall portion by pulling the knob portion away from the container opening portion, and the cap is detached from the container opening portion.
[0003]
[Problems to be solved by the invention]
When the conventional synthetic resin cap configured as described above is applied to a milk bottle as a container, the following problems exist. That is, in general, milk is filled in a milk bottle while being cooled to 5 ° C. And the opening part of the milk bottle with which the milk was filled is closed when the said cap is stoppered. When such a milk bottle is exposed to an external temperature in summer, for example, 40 ° C., the internal pressure of the milk bottle is raised, thereby causing a phenomenon that the cap is lifted and the sealing function is lowered. When the sealing function is lowered, problems such as milk oozing out from the opening of the milk bottle to wet the opening or completely leaking out from the opening. In order to solve this problem, when the protruding amount of the locking ridge locked to the locked jaw portion of the container opening is increased, the sealing function is improved, but the opening is significantly difficult. Furthermore, when the cap is struck, the thin wall portion of the skirt wall is broken due to the diameter of the skirt wall being enlarged when the locking protrusion of the cap gets over the locked jaw portion of the container opening. There is. In order to prevent breakage of the thin portion at the time of such plugging, if the thin portion is strengthened excessively, it is extremely difficult to open the plug.
[0004]
In the case of milk in particular, the difficulty of opening must be avoided because the consumer is often a weak child or woman. Therefore, when the conventional synthetic resin cap is applied to a milk bottle, the locking force to the locked jaw portion of the milk bottle opening outer peripheral surface by the locking protrusion on the inner peripheral surface of the skirt wall is limited. Therefore, it is necessary to prevent the difficulty in opening the bottle and to sufficiently cope with the increase in the internal pressure of the milk bottle, and to prevent the milk from leaking out or leaking as described above. Of course, it must also be ensured that the thin part of the skirt wall is not broken when it is plugged.
[0005]
Therefore, the main object of the present invention is to prevent the skirt wall from being broken at the time of stoppering, and to securely attach the container opening to the container opening so that the contents do not leak outside. In addition, it is to provide a novel synthetic resin cap that can be easily detached from the opening of the container when manually opened.
[0006]
Another object of the present invention is to provide a novel synthetic resin cap that is simple in structure and easy to mold, and thus can be mass-produced at low cost.
[0007]
Other objects and features of the present invention will become apparent from the following description of embodiments of a synthetic resin cap constructed according to the present invention in detail with reference to the accompanying drawings.
[0008]
[Means for Solving the Problems]
According to the present invention, a top wall and a skirt wall extending downward from the periphery of the top wall are provided, and the inner peripheral surface of the skirt wall is provided with a locked jaw portion formed on the outer peripheral surface of the container opening. In the synthetic resin cap in which a locking protrusion to be locked is formed, and a tab protruding outward in the radial direction is formed over a partial region in the circumferential direction on the outer peripheral surface at the opening end of the skirt wall, When the skirt wall is viewed in the axial direction, the tab side is positioned substantially in the center of the skirt wall at a 180 ° tab side region X of the skirt wall and another 180 ° anti-tab side region Y of the skirt wall. When divided, the skirt wall of the tab side region X is circumferentially spaced. 2 pieces Weakening lines are formed, and each of the weakening lines consists of a relatively wide thin portion extending from the open end toward the top wall, and these thin portions are 2.5mm ~ 5.0 and a plurality of weakening lines are formed in the skirt wall at intervals in the circumferential direction, each of the weakening lines being relatively narrow extending from the open end toward the top wall. These thin portions have a circumferential width of 0.5 mm to 1.8 mm, A weakening line consisting of a pair of relatively narrow thin portions is arranged adjacent to both sides in the circumferential direction of the tab and at equal intervals from both sides of the tab, and a weakening line consisting of a relatively wide thin portion is It is located farther from the tab than the weakening line consisting of a relatively narrow thin part on both sides of the tab, and is arranged at equal intervals from both sides of the tab. A synthetic resin cap is provided.
[0009]
In the cap according to the present invention, each of the weakening lines formed at least two circumferentially spaced apart on the skirt wall of the tab side region X consists of a thin portion extending from the opening end toward the top wall, Each of these thin portions is a relatively wide thin portion having a circumferential width of 2.0 mm to 5.0 mm. Such a weakening line consisting of a relatively wide thin part is relatively easily elastically deformed (elongated) in the circumferential direction of the skirt wall. The diameter of the skirt wall is relatively wide when moving over the locked jaw part in the plugging direction, and even if there is no other weakening line consisting of a thin part on the skirt wall, it is relatively wide. It is possible to easily perform the plugging without breaking the weakening line composed of the thin-walled portion, and sufficiently ensure the reliability (stability) of the cap at the time of the plugging. In addition, when another weakening line made of a thin part is formed on the skirt wall, the force for expanding the skirt wall is more easily absorbed by the elastic deformation of the entire weakening line. The weakening line as well as the other weakening lines are reliably prevented from being broken, and the reliability (stability) of the cap at the time of stoppering is sufficiently ensured.
[0010]
In addition, after the stoppering, the weakening line consisting of a relatively wide thin portion that has been temporarily elastically deformed as described above immediately returns to its original shape due to its elastic force. A predetermined locking force (holding force) for the locked jaw part formed on the outer peripheral surface of the container is secured and securely attached, and the cap is prevented from lifting due to an increase in internal pressure, and a sealing function for the container opening Is sufficiently secured. As a result, the occurrence of leakage or leakage of liquid from the container opening is sufficiently reliably prevented. The above sealing function refers to the outer peripheral surface of the sealing ridge and the container opening when an annular sealing ridge that extends downward on the inner surface of the top wall and is fitted to the inner peripheral surface of the container opening is formed. This means a sealing function between the inner peripheral surface of the portion, and when a sealing member of another form known per se is formed on the inner surface of the top wall instead of the above-described sealing protrusion, this sealing member And a sealing function between the upper end of the container opening.
[0011]
Furthermore, when opening the tap, when the tab is opened by lifting the tab, the skirt wall's locking ridge extends over the locked jaw of the container opening in the opening direction, and the weakening line consists of a relatively wide thin part. Since elastic deformation (elongation) in the circumferential direction of the skirt wall is relatively easy, the diameter of the skirt wall is relatively easy to expand (easily stretch), and there is no other weakening line consisting of a thin part on the skirt wall. Even if it is not formed, it can be easily detached from the container opening. Further, when other weakening lines made of a thin portion are formed on the skirt wall, the breakage thereof is promoted, so that the opening is further facilitated.
[0012]
Furthermore, since at least two weakening lines configured as described above are formed in the tab side region X, when a force is applied to the tab in a direction away from the container opening for finger opening (when lifted, ) Since the weakening line composed of a relatively wide thin portion is easy to extend, the diameter of the skirt wall in the tab side region X is first enlarged, and the locking protrusion in the tab side region X is engaged with the corresponding container opening. It will be easier to get over the stop jaw. As a result, opening is significantly facilitated.
[0013]
As can be easily understood from the above description, according to the cap according to the present invention, the skirt wall can be reliably prevented from being broken at the time of stoppering and the contents can be prevented from leaking to the outside. It is securely attached while maintaining a sufficiently secure seal. In addition, the amount of protrusion of the locking ridge that is locked to the locked jaw portion of the container opening can be limited to a range where a sufficient sealing performance is ensured without excessively increasing, so that the opening can be opened. The stopper can be easily carried out by both children and women. Further, in the case of a cap in which the sealing member of another form as described above is formed on the inner surface of the top wall, in order to ensure a desired sealing property, the milk bottle opening of the locking ridge on the inner peripheral surface of the skirt wall Even if the locking force to the locked jaw portion on the outer peripheral surface is increased to some extent, the opening is remarkably easy as described above, and the skirt wall thin portion at the time of plugging is reliably prevented. Therefore, the cap according to the present invention can be suitably used particularly for milk bottles containing milk. Further, the cap according to the present invention has a simple structure as a whole and can be integrally molded (injection molding or integral molding by compression molding), and can be mass-produced at low cost.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of a synthetic resin cap constructed according to the present invention will be described below in more detail with reference to the accompanying drawings. In addition, although embodiment described below is not restricted to it, it is a synthetic resin cap applied to the milk bottle which is a container. Referring to FIGS. 1 to 6, the synthetic resin cap generally indicated by reference numeral 2 includes a top wall 4 that is substantially disk-shaped, and a skirt wall 6 that extends downward from the periphery of the top wall 4. Yes. An annular seal protrusion (inner ring) 8 extending downward is formed on the inner surface of the top wall 4. The outer peripheral surface of the seal protrusion 8 is detachably fitted to the inner peripheral surface 102 of the opening of the milk bottle 100 shown in FIGS. A locking ridge 10 is formed on the inner peripheral surface of the skirt wall 6. The locking ridge 10 is detachably locked to a locked jaw portion 104 (see FIGS. 8 and 9) formed on the outer peripheral surface of the opening of the milk bottle 100. The lower surface of the top wall 4 and the radially outward position of the seal ridge 8 is connected to the lower surface of the top wall 4 and the inner peripheral surface of the skirt wall 6, and the corner portion 11 having a curved section. Are formed with annular ribs 4a and 4b, respectively. On the outer peripheral surface at the open end of the skirt wall 6, tabs 12 protruding outward in the radial direction are formed over a part in the circumferential direction. Three ribs 13 are integrally formed between the base of the tab 12 and the skirt wall 6 at intervals in the circumferential direction. As clearly shown in FIG. 6, each of the ribs 13 has a predetermined thickness in the circumferential direction of the skirt wall 6 and is formed such that the axial cross section of the skirt wall 6 forms a triangle.
[0015]
The skirt wall 6 has a total of nine weakening lines extending from the opening end toward the top wall 4 at intervals in the circumferential direction, that is, two weakening lines 20 (a and b consisting of relatively wide thin portions). ) And seven weakened lines 30 (a to g) made of relatively narrow thin portions are formed at intervals in the circumferential direction. The “relatively wide thin portion” and the “relatively narrow thin portion” will be specifically described later. When the skirt wall 6 is viewed in the axial direction of the cap 2, the 180 ° tab side region X of the skirt wall 6 where the tab 12 is positioned substantially in the center in the circumferential direction, and the other 180 ° anti-tab side of the skirt wall 6. When divided into the region Y, the tab side region X is formed with two weakening lines 20 (20a and 20b) made of the relatively wide thin part, and the weakening made of the relatively narrow thin part. Two lines 30 (30a and 30b) are formed. On the other hand, only five weakening lines 30 (30c to 30g) made of the relatively narrow thin portion are formed in the anti-tab side region Y.
[0016]
More specifically, as clearly shown in FIG. 3, in the tab side region X, the weakening lines 30 a and 30 b made of a relatively narrow thin portion are adjacent to both sides in the circumferential direction of the tab 12. Further, the weakening lines 20a and 20b, which are arranged at equal intervals from both sides and are formed of relatively wide thin portions, are provided on both sides in the circumferential direction of the tab 12 from the both sides of the tab 12 in the circumferential direction from the weakening lines 30a and 30b. They are spaced apart and are arranged at equal intervals from both sides of the tab 12. In the anti-tab side region Y, the weakening lines 30c to 30g made of a relatively narrow thin portion are arranged at equal intervals. One of the weakening lines 30 g is disposed on the opposite side in the diametrical direction with respect to the circumferential center position of the tab 12. A plurality of ribs 14 extending in the axial direction at intervals in the circumferential direction are formed on the outer peripheral surface of the skirt wall 6 where the weakening lines 20 and 30 are not present. In FIG. 3, reference numeral L1 is a line that separates the tab side region X and the anti-tab side region Y (a line that passes through the axis of the cap 2), and L2 is a line that passes through the axis of the cap 2 and is orthogonal to the line L1. . As is clear from the above description, the weakening line 30g is positioned on the line L2. The interval in the circumferential direction of each of the weakening lines 20a and 20b and 30a to 30g is appropriately set. In the embodiment shown in FIG. 3, the circumferential direction of the region sandwiching the tab 12 between the weakening lines 30a and 30b. The angle is 80 ° (the circumferential angle between the circumferential center of the tab 12 and the weakening line 30a and the circumferential angle between the circumferential center of the tab 12 and the weakening line 30b are each 40 °), and in other regions The circumferential angles between each of the weakening lines 30a, 20a, 30c, 30e, 30g, 30f, 30d, 20b and 30b are all 35 °.
[0017]
Since the weakening lines 20a and 20b made of a relatively wide thin portion have substantially the same configuration, only one weakening line 20a will be described here. Referring mainly to FIGS. 3 to 5, the weakening line 20 a composed of a relatively wide thin portion is formed in the upper region S <b> 1 near the top wall 4 in the skirt wall 6 as clearly shown in FIG. 5. A relatively thin first thin portion 22 having a residual thickness, and a second thin portion 24 having a residual thickness smaller than the first thin portion 22 formed in the lower region S2 near the opening end, It is composed of The weakening line 20a includes a groove 26 formed so as to extend linearly over the entire axial direction of the outer peripheral surface of the skirt wall 6. The groove 26 has a predetermined circumferential width and depth. That is, in this embodiment, the weakening line 20 a thinner than the thickness of the skirt wall 6 is formed by forming the groove 26 extending in the axial direction on the outer peripheral surface of the skirt wall 6.
[0018]
The first thin portion 22 is formed thinner than the skirt wall 6 by the depth of the groove 26. The radially outer surfaces of the first thin portion 22 and the second thin portion 24 are on the same plane (on the bottom surface of the groove 26), and the inner peripheral surface (of course locking) of the first thin portion 22 Since the inner peripheral surface excluding the protrusions 10 is on the same plane (on the same inner peripheral surface) as the corresponding inner peripheral surface of the skirt wall 6, the radially inner surface of the second thin portion 24 is The first thin portion 22 is positioned radially outward from the radially inner surface. The second thin-walled portion 24 is positioned below the locking ridge 10 and has a lower end inner peripheral surface 24a on the opening end side (of course, an inner peripheral surface excluding the locking ridge 10) of the skirt wall 6. It is positioned on the same surface (on the same inner peripheral surface) as the corresponding lower end inner peripheral surface. Therefore, the inner diameter of the inner peripheral surface 24a of the lower end portion where the second thin portion 24 of the skirt wall 6 exists is larger than the inner diameter of the inner peripheral surface of the portion where the first thin portion 22 of the skirt wall 6 exists.
[0019]
As clearly shown in FIG. 4, the relatively wide thin portion constituting the weakening line 20a has a circumferential width W1 of 2.0 mm to 5.0 mm. At both ends in the circumferential direction of the thin wall portion in the skirt wall 6, there are inclined portions where the radial thickness gradually increases toward the outer diameter side as the distance from the circumferential ends of the thin wall portion increases in the circumferential direction. Both ends in the circumferential direction of the thin portion are defined by two boundaries with these inclined portions, and the circumferential width W1 of the thin portion is the width between the circumferential ends of the thin portion. The circumferential width W1 of the relatively wide thin portion constituting the weakening line 20a is the circumferential width of the bottom of the groove 26 in the above embodiment. In FIG. 4, reference symbol W <b> 2 indicates a circumferential width of the groove 26 on the radially outer side (a width between two boundaries between the outer peripheral surface of the skirt wall 6 and each of the inclined portions). As shown in the figure, the dimensional relationship between W1 and W2 is W1 <W2.
[0020]
Since each of the weakening lines 30a to 30g made of a relatively narrow thin portion has substantially the same configuration, only one weakening line 30c will be described here. The weakening line 30c consisting of a relatively narrow thin part differs from the weakening line 20a consisting of a relatively wide thin part in that the relatively wide thin part constituting the weakening line 20a is 2.0 mm. While having a circumferential width W1 of ˜5.0 mm, the relatively narrow thin portion constituting the weakening line 30c has a circumferential width W1 of 0.5 mm to 1.8 mm. Accordingly, the circumferential width W2 is also defined to be small, and the other configuration is substantially the same as that of the weakening line 20a.
[0021]
The locking protrusions 10 are substantially separated into a plurality in the circumferential direction at the formation sites of the weakening lines 20a and 20b and the weakening lines 30a to 30g. As shown in FIG. 2, the circumferential ends of the locking ridges 10 separated from each other have a curved shape rather than a linear shape extending at least in the axial direction when viewed in the radial direction from the axial center. There is no. As is apparent from FIG. 5, the locking protrusion 10 has a substantially parabolic mountain shape with respect to the inner peripheral surface of the skirt wall 6 in the axial direction. It is preferable that the lower end of the first thin portion 22 extends downward to at least the axial direction region where the locking ridge 10 is present, but in the embodiment, the top portion in the radial direction of the locking ridge 10. Extends downward to a position exceeding the axial position 10a corresponding to.
[0022]
The cap 2 configured as described above has a simple structure as a whole, and can be easily formed by injection molding or compression molding (preferably injection molding is practical) from an appropriate synthetic resin, for example, low density polyethylene (LDPE). Can be integrally molded. Therefore, mass production can be performed at low cost. As shown in FIGS. 8 and 9, the cap 2 configured as described above is detachably fitted to the inner peripheral surface 102 of the opening portion of the milk bottle 100 by the plugging so that the outer peripheral surface of the seal protrusion 8 is detachable. Then, the locking ridge 10 is detachably locked to the locked jaw 104 formed on the outer peripheral surface of the opening, so that the milk bottle 100 is attached to the opening.
[0023]
In the cap 2, the two weakening lines 20 a and 20 b formed on the skirt wall 6 in the tab side region X at intervals in the circumferential direction are formed of thin portions extending from the opening end toward the top wall 4. Each of these thin portions is a relatively wide thin portion having a circumferential width W1 of 2.0 mm to 5.0 mm. Since the weakening lines 20a and 20b made of such a relatively wide thin portion can be elastically deformed (elongated) in the circumferential direction of the skirt wall 6 relatively easily, the locking protrusion of the skirt wall 6 at the time of plugging. Since the diameter of the skirt wall 6 is relatively easy to expand when the strip 10 goes over the locked jaw 104 of the opening of the milk bottle 100 in the direction of plugging, the weakening lines 20a and 20b are not broken. It is possible to easily perform the stoppering without breaking, and the reliability (stability) of the cap 2 at the time of stoppering is sufficiently ensured. The skirt wall 6 has other weakening lines 30a to 30g made of a relatively narrow thin portion having a circumferential width W1 of 0.5 mm to 1.8 mm over the tab side region X and the anti-tab side region Y. Since it is formed, the force for expanding the skirt wall 6 is more easily absorbed in a balanced manner by the elastic deformation of the entire weakening line (weakening lines 20a and 20b, weakening lines 30a to 30g). As well as the weakening lines 20a and 20b, the breakage of the other weakening lines 30a to 30g made of a relatively narrow thin part is also reliably prevented, and the reliability (stability) of the cap 2 at the time of plugging is ensured. Sufficiently secured.
[0024]
After the plugging, the weakening lines 20a and 20b made of a relatively wide thin part temporarily elastically deformed as described above and the other weakening lines 30a to 30g made of a relatively thin thin part are Since the elastic shape immediately returns to the original shape, a predetermined locking force (holding force) for the locked jaw portion 104 formed on the outer peripheral surface of the opening portion of the milk bottle 100 of the locking ridge 10 is ensured. The cap 2 is reliably prevented from being lifted by an increase in internal pressure, and the sealing function of the seal protrusion 8 with respect to the inner peripheral surface 102 of the opening is sufficiently ensured. As a result, the occurrence of milk oozing out or leaking from the opening of the milk bottle 100 is sufficiently reliably prevented. In addition, when the sealing member of the other forms as described above is formed on the inner surface of the top wall 6, the sealing function means a sealing function between the sealing member and the upper end portion of the opening of the milk bottle 100. To do. In this case, the same sealing effect as described above can be obtained.
[0025]
Further, since two weakening lines 20a and 20b are formed in the tab side region X, when a force is applied to the tab 12 by a finger in a direction away from the opening of the milk bottle 100 for opening (if lifted) ), Since the weakening lines 20a and 20b are formed of a relatively wide thin portion, elastic deformation (elongation) in the circumferential direction of the skirt wall 6 can be performed relatively easily. Since the diameter is easily expanded, the weakening lines (particularly the weakening lines 30c and 30d) are easily broken, and the locking ridges 104 in the opening of the milk bottle 100 corresponding to the locking protrusions 10 in the tab side region X are formed. It will be easier to get over. As a result, the opening is remarkably facilitated and can be easily detached from the opening of the milk bottle 100. Since the skirt wall 6 is also formed with other weakening lines 30a to 30g made of a relatively narrow thin portion, the diameter of the skirt wall 6 becomes easier to expand as a whole, and the cap 2 in the late stage of opening the cap 2 The bottle can be easily separated, and thus can be opened more easily. The weakening lines 30a and 30b arranged at equal intervals on both sides in the circumferential direction of the tab 12 also facilitate the lifting operation by the tab 12 when opening.
[0026]
Since the weakening lines 20a and 20b made of a relatively wide thin portion are arranged at equal intervals on both sides in the circumferential direction of the tab 12, the weakening lines 20a and 20b are subjected to a large load when the tab 12 is lifted. Therefore, the locking protrusion 10 near the tab 12 is easily detached from the locked jaw portion 104 of the milk bottle 100 at the time of opening, and opening is particularly easy.
[0027]
The skirt wall 6 of the non-tab-side region Y includes five weakening lines 30c to 30g (a relatively narrow thin portion having a circumferential width W1 of 0.5 mm to 1.8 mm) spaced in the circumferential direction. Since the weakening line) is formed, elastic deformation on the side opposite to the tab side region Y at the time of opening is performed in a well-balanced manner, and the opening is further facilitated. One weakening line 30g among the weakening lines 30a to 30g is disposed on the opposite side to the circumferential direction center position of the tab 12 in the opposite tab side region Y substantially on the diametrically opposite side. In the state where the tab 12 is raised and particularly one of the weakening lines 30c and 30d is broken, a load that tends to expand in the circumferential direction acts on the weakening line 30g in the anti-tab side region Y. Therefore, the weakening line 30g is elastically extended, so that the cap 2 can be easily separated from the bottle, and therefore, the opening is significantly facilitated. Further, since there are four weakening lines 30e, 30f, 30c and 30d) at equal intervals on both sides in the circumferential direction of the weakening line 30g, the elastic deformation on the anti-tab side region Y side at the time of opening is further balanced. Well done and easier to open.
[0028]
Since the three ribs 13 are integrally formed between the base of the tab 12 and the skirt wall 6, the rigidity of the connecting portion between the tab 12 and the skirt wall 6 is enhanced. As a result, at the time of opening, the locking protrusions 10 on the inside of the tab 12 and in the vicinity thereof can more easily get over the locked jaw 104 of the opening of the corresponding milk bottle 100, and the opening is further facilitated. Become.
[0029]
Each of the weakening lines 20a and 20b and 30a to 30g of the cap 2 is composed of a first thin portion 22 formed in the upper region S1 and a second thin portion 24 formed in the lower region S2 near the opening end. In particular, due to the presence of the first thin portion 22 in the upper region S1, the weakening lines 20 and 30 can be easily and reliably plugged into the opening. Furthermore, due to the presence of the first thin wall portion 22, a predetermined locking force (holding) with respect to the locked jaw portion 104 formed on the outer peripheral surface of the opening of the locking ridge 10 after the stoppering. Force) is secured, and the cap 2 is reliably prevented from lifting due to an increase in internal pressure, and the sealing function of the sealing protrusion 8 with respect to the inner peripheral surface 102 of the opening is sufficiently ensured. As a result, the occurrence of milk oozing out or leaking from the opening of the milk bottle 100 is sufficiently reliably prevented. Of course, similar effects can be obtained even in the cap 2 having no seal protrusion 8.
[0030]
As described above, the two weakening lines 20 (20a and 20b) made of a relatively wide thin portion are arranged in the tab side region X, and the weakening lines 30 made of a relatively narrow thin portion are arranged on the tab side. Two (30a and 30b) are arranged in the region X, and five (30c to 30g) are arranged in the non-tab side region Y. And for opening, when a force is applied to the tab 12 in the direction away from the opening by the finger, one of the weakening lines 30c and 30d is first broken, so that the cap 2 is removed from the opening. It can be easily removed. In particular, due to the presence of the second thin portion 24 in the lower region S2, when the force as described above is applied to the tab 12, the weakening line easily breaks from the lower end on the opening end side (in the initial stage of plug opening). Opening is easily accomplished because it is easy to break. As a result, the locking force of the locking ridge 10 on the locked jaw 104 can be limited within a range where a sufficient sealing performance can be secured without being excessively strong. Even women can easily accomplish it.
[0031]
In the cap 2, it is preferable that the first thin-walled portion 22 has a lower end that extends downward to an axial region where at least the locking ridge 10 is present. More preferably, it extends downward to a position beyond the axial position 10a corresponding to the top of the direction (see FIG. 5). Since the lower end of the first thin portion 22 extends downward to the axial direction region where the locking ridge 10 exists, the locking force of the locking ridge 10 with respect to the locked jaw portion 104 is increased, Sufficient holding power (maintenance of sealing performance) is secured against an increase in internal pressure in milk bottle 100. Therefore, when the lower end of the first thin portion 22 extends downward to a position exceeding the axial position 10a corresponding to the top of the locking protrusion 10 in the radial direction, the holding force is further increased.
[0032]
In the cap 2, it is preferable that the locking protrusions 10 are not provided in at least a part of the circumferential region where the tab 12 of the tab side region X is formed. In the said embodiment, as shown in FIG. 3, it is comprised so that the latching protrusion 10 may not exist in the area | region except the both ends in the area | region of the circumferential direction in which the tab 12 is formed of the skirt wall 6. As shown in FIG. With such a configuration, the portion of the tab 12 is easily raised at the initial stage of opening, and opening is facilitated.
[0033]
In the cap 2, the first thin portion 22 has a thickness of 0.35 mm to 0.6 mm, and the second thin portion 24 has a thickness of 0.15 mm to 0.3 mm. Is preferred. If the first thin portion 22 is excessively thick, it is extremely difficult to open the plug. If the first thin portion 22 is excessively thin, the locking force is reduced and a desired sealing function cannot be obtained. When the first thin portion 22 has a thickness of 0.6 mm or less, particularly 0.35 mm to 0.6 mm, a desired sealing function can be obtained and the plug can be easily opened. Further, if the second thin portion 24 is excessively thick, it is extremely difficult to open the plug. If the second thin portion 24 is excessively thin, the possibility of breaking at the time of plugging becomes strong. When the second thin-walled portion 24 has a thickness of 0.3 mm or less, particularly 0.15 mm to 0.3 mm, it is easy to open the plug and prevent breakage at the time of plugging.
[0034]
In the cap 2, the lower surface of the top wall 4 and the radially outer position of the seal protrusion 8 is connected to the lower surface of the top wall 4 and the inner peripheral surface of the skirt wall 6. The portion 11 is formed with annular ribs 4a and 4b, respectively. As shown in FIGS. 8 and 9, in the state where the cap 2 is attached to the opening of the milk bottle 100 as described above, the rib 4a is brought into close contact with the upper end surface of the opening, and the rib 4b is a cross section of the opening. Is closely attached to the surface of the peripheral edge forming a curved surface. In this state, the milk bottle 100 is accommodated in the refrigerator, and when the temperature of the milk is lowered to a temperature lower than the filling temperature 5 ° C., for example, 4 ° C., the inside of the milk bottle 100 becomes negative pressure and tries to suck the outside air. However, the ribs 4a and 4b are more closely attached to the surface of the opening to improve the sealing function, and suction of outside air is reliably prevented.
[0035]
As can be easily understood from the above description, in the cap 2, at least two weakening lines 20 are formed in the skirt wall 6 of the tab side region X at intervals in the circumferential direction. It is important that the thin portion extends from the opening end toward the top wall 4 and each of the thin portions is a relatively wide thin portion having a circumferential width W1 of 2.0 mm to 5.0 mm. If the circumferential width W1 is excessively large, the locking force of the locking protrusion 10 with respect to the locked jaw portion 104 may be reduced after the plugging, and a desired sealing function may not be obtained. Further, if the circumferential width W1 is excessively small, the possibility of breakage at the time of plugging becomes strong. With the arrangement and configuration described above, a relatively well-balanced expansion (elongation) of the diameter of the skirt wall 6 is performed at the time of plugging, and when the tab 12 is lifted at the time of plugging, it exists in the tab side region X. A relatively well-balanced expansion (elongation) of each of the weakening lines 20 is performed, or a break in at least one of each of the weakening lines is easily performed accordingly. Therefore, as described above, it is possible to perform the plugging without breaking while ensuring the sealing function and to easily perform the plugging.
[0036]
In particular, the circumferential width W1 of the relatively wide thin portion constituting the weakening line 20 is preferably 2.5 mm to 4.0 mm. By defining the circumferential width W1 in such a range, it is possible to more reliably practically perform the plugging without breakage and the easy opening while ensuring the sealing function.
[0037]
When at least two of the weakening lines 20 are formed on the skirt wall 6 of the tab side region X, a plurality of weakening lines are formed on the skirt wall 6 of the anti-tab side region Y at intervals in the circumferential direction. Each of the weakening lines is preferably composed of a thin portion extending from the opening end toward the top wall 4. With this configuration, a relatively well-balanced expansion (elongation) of the diameter of the skirt wall 6 at the time of plugging is obtained, and breakage is prevented. After the plugging, the locked jaw 104 of the locking ridge 10 is locked. The desired sealing function is ensured by securing the locking force with respect to, and at the time of opening, the separation of the bottle is improved particularly at the later stage of opening and the opening is facilitated. Further, as in the above embodiment, each of the weakening lines in the anti-tab-side region Y is constituted by a weakening line 30 composed of a relatively narrow thin portion having a circumferential width W1 of 0.5 mm to 1.8 mm. It is preferable that With such a configuration, it is possible to practically and reliably obtain a desired function at the time of plugging, after plugging, and at the time of opening.
[0038]
The cap 2 as a whole has a simple structure, is easy to mold (injection molding or integral molding by compression molding), and can be mass-produced at low cost. Referring to FIG. 7 schematically showing the relationship between the molding die and the molded cap 2, a first male die 31 is positioned coaxially with the axis of the cap 2 (not shown). A second male die 32 is positioned on the radially outer side of the first male die 31 so as to be relatively movable. A stripper 34 is positioned so as to be movable relative to the second male mold 32 at a position on the radially outer side of the second male mold 32 and closer to the lower side in the axial direction. A female die 36 is positioned at the upper end of the stripper 34. The lower end of the female die 36 is positioned at the upper end of the stripper 34, the outer side in the radial direction of the second male die 32, and the upper side of each of the second male die 32 and the first male die 31. Each is positioned with a predetermined gap (space). As can be easily understood from FIG. 7, the surfaces of the first male mold 31, the second male mold 32, the stripper 34, and the female mold 36 that are positioned in the molding position as described above and that face each other with a gap therebetween. The shape is formed so that the cap 2 can be molded. In FIG. 7, the axis line (not shown) of the cap 2 is positioned so as to extend in the vertical direction. However, in practice, the axis line of the cap 2 is generally positioned so as to extend substantially in the horizontal direction. Molded.
[0039]
After the cap 2 is integrally formed by injection molding or compression molding using the molding die as described above, die cutting is performed in the following order. That is, first, the female die 36 is moved upward in FIG. 7 and is released above the cap 2. Next, the first male mold 31 is moved downward in FIG. 7 while moving relative to the second male mold 32, and is detached below the cap 2. Next, the second male mold 32 is moved relative to each other in the lower part of FIG. 7 and the stripper 34 is moved upward in FIG. The cap 2 is formed with a seal ridge 8 having a shape such that a part thereof protrudes radially outward and a locking ridge 10 having a shape such that a part thereof protrudes radially inward. Therefore, so-called unreasonableness is performed. Since the first male mold 31 is not already present at the molding position, the sealing protrusion 8 is elastically deformed radially inward, so that unreasonable removal is performed, and the female mold 36 is not present at the molding position. The skirt wall 6 on which the stop ridge 10 is formed is elastically deformed in a form that bulges outward in the radial direction, thereby forcibly removing it.
[0040]
In the cap 2, the outer peripheral surface of the skirt wall 6 is formed with a plurality of ribs 14 extending in the axial direction at intervals in the circumferential direction, so that the skirt wall 6 is reinforced by each of the ribs 14. For this reason, the bulging of the skirt wall 6 due to the locking protrusion 10 is somewhat lowered when the plugging is performed and when unreasonable removal is performed. As a result, breakage of the weakening line 20 at the time of stoppering and unreasonable removal is surely avoided.
[0041]
In the cap 2, the weakening lines 20 (a and b) and the weakening lines 30 a to 30 g include a groove 26 formed so as to extend linearly over the entire axial direction of the outer peripheral surface of the skirt wall 6. A lower end inner peripheral surface 24a of the thin wall portion 24 below the locking ridge 10 on the opening end side of the skirt wall 6 is positioned on the same plane as the corresponding lower end inner peripheral surface of the skirt wall 6. Yes. Due to this configuration, the lower outer peripheral surface of the second male mold 32 that is forcibly removed from the portion corresponding to the lower end inner peripheral surface 24a of the skirt wall 6 can be circular, and therefore the second The inner peripheral surface of the fitting hole of the stripper 34 in which the outer peripheral surface of the second male mold 32 is fitted so as to be relatively movable can also be circular. As a result, the structure of the mold is remarkably simplified, the alignment between the second male mold 32 and the stripper 34 is facilitated, the wear between the second male mold 32 and the stripper 34 is reduced, and the cap The effect that the molding cost of 2 is reduced is obtained. As a result, the productivity of the cap 2 is improved, and the molding cost of the cap 2 is greatly reduced.
[0042]
In the cap 2, the thin-walled portion is formed in the upper region S <b> 1, the first thin-walled portion 22 having a relatively thick residual thickness, and the first thin-walled portion 22 formed in the lower region S <b> 2. Formability is improved due to the fact that the second thin portion 24 is formed with a small thickness. That is, when the thin portion is constituted only by a thin portion having a small residual thickness, such as the second thin portion 24, the composition in the gap of the forming die corresponding to the thin portion of the skirt wall 6 is formed at the time of molding. The fluidity of the resin is remarkably worse than that of the mold corresponding to the other part of the skirt wall 6. This is because the gap of the mold corresponding to the thin wall portion is considerably narrower than the gap of the mold corresponding to the other part of the skirt wall 6, and therefore, during molding, the synthetic resin first flows into the wide gap and then the narrow gap. This is because they tend to flow into. Specifically, in general, in the case of injection molding, the synthetic resin is injected into the gap from a portion corresponding to the axial center portion of the top wall 4 of the cap 2. The injected synthetic resin flows from the gap corresponding to the top wall 4 first into the wide gap corresponding to the portion other than the thin portion of the skirt wall 6 and reaches the portion corresponding to the open end, and then There is a strong tendency to flow from the gap on the opening end side into a narrow gap corresponding to the thin portion. At this time, the synthetic resin hardly flows from the gap corresponding to the top wall 4 directly into the narrow gap corresponding to the thin wall portion. For this reason, the synthetic resin may not be completely filled in the upper portion of the narrow gap corresponding to the thin portion, and a portion lacking in the upper portion of the thin portion of the molded cap 2 is generated.
[0043]
On the other hand, in the cap 2 according to the present invention, since the thin portion is composed of the first thin portion 22 and the second thin portion 24, the synthetic resin is sufficient for the entire gap corresponding to the thin portion. Since filling is reliably performed and moldability is improved, a problem that a portion lacking in the upper portion of the second thin portion 24 of the molded cap 2 is reliably prevented. The reason will be described in detail. As described above, the synthetic resin injected into the gap corresponding to the top wall 4 is the first thin portion of the skirt wall 6 first from the gap corresponding to the top wall 4. After flowing into a wide gap corresponding to a portion other than the portion 22 and the second thin portion 24 and reaching a portion corresponding to the opening end, a narrow portion corresponding to the second thin portion 24 is then formed from the gap on the opening end side. This is because the gap flows into the gap, but the gap corresponding to the second thin portion 24 is shorter than the conventional one, so that it can be filled relatively easily. Further, a part of the synthetic resin injected into the gap corresponding to the top wall 4 also flows toward the gap corresponding to the first thin portion 22 which is wider than the gap corresponding to the second thin portion 24. This is because it is presumed that they will be injured.
[0044]
As can be easily understood from the above description, according to the cap 2 according to the present invention, the skirt wall 6 can be reliably prevented from being broken at the time of stoppering and the milk bottle 100 can be prevented from leaking to the outside. It is securely attached to the opening while maintaining a sufficiently secure sealed state. In addition, even if the seal ridge 8 as described above is present, the sealing performance without excessively increasing the protruding amount of the locking ridge 10 that is locked to the locked jaw 104 of the opening of the milk bottle 100 is achieved. Therefore, the opening can be easily performed by both children and women. Therefore, the said cap 2 which concerns on this invention can be used conveniently for the milk bottle 100 in which the milk was accommodated especially. Further, the cap 2 according to the present invention has a simple structure as a whole and can be integrally molded (injection molding or integral molding by compression molding), and can be mass-produced at low cost.
[0045]
Next, with reference mainly to FIG. 10 and FIG. 11, another embodiment of a synthetic resin cap constructed according to the present invention will be described. 10 and 11, substantially the same parts as those in FIGS. 1 to 9 are denoted by the same reference numerals, and description thereof is omitted. In the cap 40 which is only partially shown in FIGS. 10 and 11 and is not shown in its entirety, the skirt wall 6 is spaced apart in the circumferential direction, like the synthetic resin cap 2 described with reference to FIGS. A total of nine weakening lines extending from the open end toward the top wall 4, i.e., two weakening lines 42 (a and b) consisting of relatively wide thin portions and seven relatively narrow lines. Weakening lines 44 (a to g) each having a thin wall portion are formed at intervals in the circumferential direction (FIGS. 10 and 11 show only the weakening line 42a and the weakening line 44c thereof. ) The weakening lines 42a and 42b are disposed at circumferential positions corresponding to the weakening lines 20a and 20b of the cap 2, respectively, and the weakening lines 44a to 44g are circumferential directions corresponding to the weakening lines 30a to 30g of the cap 2, respectively. Arranged in position. As can be easily understood by comparing FIG. 10 and FIG. 11 with FIG. 4 and FIG. 5, the difference between the cap 40 and the cap 2 is that the configuration of the thin portion of the weakening line is different. .
[0046]
Since the weakening lines 42a and 42b made of a relatively wide thin portion have substantially the same configuration, only one weakening line 42a will be described here. The weakening line 42a composed of a relatively wide thin part is formed in the upper region S1 near the top wall 4 in the skirt wall 6 and the first thin part 22 having a relatively thick residual wall and the lower part near the opening end. It is comprised from the said 2nd thin part 24 whose residual thickness is thinner than the said 1st thin part 22 formed in area | region S2 (this basic structure is substantially the same as the weakening lines 20 and 30 of the said cap 2) Is). The weakening line 42a includes a groove 46 formed so as to extend linearly over a part of the inner peripheral surface of the skirt wall 6 in the axial direction. The groove 46 has a predetermined circumferential width and depth, and is formed to extend from the opening end of the skirt wall 6 by a predetermined length S1 + S2 toward the top wall 4 side. That is, in this embodiment, the weakening line 42 a thinner than the thickness of the skirt wall 6 is formed by forming the groove 46 extending in the axial direction on the inner peripheral surface of the skirt wall 6. The first thin portion 22 is formed thinner than the skirt wall 6 by the depth of the groove 46. Since the radially outer surfaces of the first thin portion 22 and the second thin portion 24 are on the same plane (on the outer peripheral surface of the skirt wall 6), the radially inner side of the second thin portion 24 This surface is positioned radially outward from the radially inner surface of the first thin portion 22.
[0047]
As clearly shown in FIG. 10, the relatively wide thin portion constituting the weakening line 42a has a circumferential width W1 of 2.0 mm to 5.0. At both ends in the circumferential direction of the thin portion of the skirt wall 6, there are inclined portions where the thickness in the radial direction gradually increases toward the inner diameter as the distance from the circumferential ends of the thin portion increases. Both circumferential ends of the portion are defined by two boundaries with these inclined portions, and the circumferential width W1 of the thin portion is the width between the circumferential ends of the thin portion. The circumferential width W1 of the relatively wide thin portion constituting the weakening line 42a is the circumferential width of the bottom of the groove 48 in the above embodiment. In FIG. 10, symbol W <b> 3 indicates the circumferential width (the width between two boundaries between the inner peripheral surface of the skirt wall 6 and each of the inclined portions) on the radially inner side of the groove 46. As shown in the figure, the dimensional relationship between W1 and W3 is W1 <W3.
[0048]
Since the weakening lines 44a to 44g made of a relatively narrow thin portion have substantially the same structure, only one weakening line 44c will be described here. The weakening line 44c made of a relatively narrow thin portion differs from the weakening line 42a made of a relatively wide thin portion in that the relatively wide thin portion constituting the weakening line 42a is 2.0 mm. While having a circumferential width W1 of ˜5.0 mm, the relatively narrow thin portion constituting the weakening line 44c has a circumferential width W1 of 0.5 mm to 1.8 mm. That is, along with this, the circumferential width W3 is also defined to be small. Since other configurations are substantially the same as the weakening line 42a, description thereof is omitted.
[0049]
As is clear from the above description, the cap 40 has substantially the same configuration as the cap 2, so that substantially the same operational effect as the cap 2 described in detail above is achieved. However, the cap 2 is superior in formability due to the difference in the configuration of the thin portion.
[0050]
Next, still another embodiment of the synthetic resin cap constructed according to the present invention will be described with reference mainly to FIG. In FIG. 12, parts that are substantially the same as those in FIGS. 1 to 9 are denoted by the same reference numerals, and description thereof is omitted. In the skirt wall 6 of the cap 50, which is only partially shown in FIG. 12, the weakening line composed of two thin portions in total, that is, the weakening line composed of two relatively wide thin portions. 20a and 20b are formed at intervals in the circumferential direction. These weakening lines 20a and 20b are formed on the skirt wall 6 in the tab side region X. Although the circumferential position of the skirt wall 6 of the tab side region X of the weakening lines 20a and 20b is not limited to this, it is the same as that of the weakening lines 20a and 20b of the cap 2. No other weakening lines are formed on the skirt wall 6. Therefore, the cap 50 has a configuration in which only the weakening lines 20a and 20b are left on the skirt wall 6 in the cap 2, and the other parts of the skirt wall 6 are configured such that the weakening lines 30a to 30g do not exist. . A plurality of the locking ridges 10 are formed on the inner peripheral surface of the skirt wall 6 in the same form as the cap 2, but the shape, number, and length in the circumferential direction are not limited to this. The arrangement position and the like are set as appropriate.
[0051]
In the cap 50, since the two weakening lines 20a and 20b are formed in the skirt wall 6 in the tab side region X at intervals in the circumferential direction in the same manner as the cap 2, A relatively well-balanced expansion (elongation) of the diameter of the skirt wall 6 is performed, and when the tab 12 is lifted at the time of opening, the relative balance of each of the weakening lines 20a and 20b existing in the tab side region X is increased. Good expansion (elongation) is performed, or breakage in at least one of each of the weakening lines 20a and 20b is easily performed. Therefore, as described above, it is possible to perform the plugging without breaking while ensuring the sealing function and to easily perform the plugging. In the cap 50, no other weakening lines are formed in the tab side region X and the anti-tab side region Y, so that the locking ridge 10 is engaged with the locked jaw 104 of the milk bottle 100. The stopping force can be stronger than that of the cap 2, and thus a stronger sealing function than that of the cap 2 can be obtained. In order to prevent the breakage from the weakening lines 20a and 20b when the cap 50 is plugged and to improve the effect of separating the bottle when the cap 50 is opened, the overall thickness of the skirt wall 6 is made relatively thin, It is preferable to suppress the locking force by appropriately setting the shape, number, circumferential length, arrangement position, and the like of the locking ridges 10. The configuration of the cap 50 is significantly simpler than those of the caps 2 and 40, and can be mass-produced at a lower cost. In addition, since the effect based on a structure common with the cap 2 is as having stated previously, description is abbreviate | omitted. Even if the weakening lines 42a and 42b are provided in place of the weakening lines 20a and 20b, substantially the same operational effects as described above can be obtained.
[0052]
Next, still another embodiment of the synthetic resin cap constructed according to the present invention will be described with reference mainly to FIG. In FIG. 13, substantially the same parts as those in FIGS. 1 to 9 are denoted by the same reference numerals and description thereof is omitted. In the skirt wall 6 of the cap 60, which is only partially shown in FIG. 13, the weakening line consisting of a total of three thin portions, that is, the weakening line consisting of three relatively wide thin portions. 20a, 20b and 20c are formed at intervals in the circumferential direction. Of these, the weakening lines 20a and 20b are formed in the skirt wall 6 of the tab side region X. The circumferential positions of the weakening lines 20a and 20b in the tab side region X are not limited to this, but are the same as those of the weakening lines 20a and 20b of the cap 2. The other weakening line 20c is the skirt wall 6 in the anti-tab-side region Y, and is formed on the substantially diametrically opposite side of the circumferential center position of the tab 12. The configuration of the weakening line 20c is substantially the same as that of the weakening lines 20a and 20b, and a description thereof will be omitted. As is apparent from the above description, the cap 60 has a configuration in which the weakening line 20c is added to the cap 50 substantially on the opposite side in the diametrical direction with respect to the circumferential center position of the tab 12.
[0053]
In the cap 60, since the two weakening lines 20a and 20b are formed in the skirt wall 6 in the tab side region X at intervals in the circumferential direction, exactly the same as the cap 2 and the cap 50. In FIG. 2, the diameter of the skirt wall 6 is expanded (stretched) in a relatively balanced manner, and when the tab 12 is lifted at the time of opening, each of the weakening lines 20a and 20b existing in the tab side region X is compared. A well-balanced expansion (elongation) is performed, or a break in at least one of each of the weakening lines 20a and 20b is easily performed. Therefore, as described above, it is possible to perform the plugging without breaking while ensuring the sealing function and to easily perform the plugging. In the cap 60, the weakening line 20c is formed on the skirt wall 6 in the anti-tab side region Y substantially on the diametrically opposite side of the circumferential center position of the tab 12. As described above, when the cap is opened, the cap 60 can be easily separated, and therefore, the opening is facilitated. The weakening line 20c disposed substantially on the opposite side in the diameter direction with respect to the center position in the circumferential direction of the tab 12 is a relatively wide weakening line. It is possible to obtain the above-described effect of separating the bottle, which is equivalent to or close to the arrangement of a plurality of relatively narrow weakening lines 30 or 44 in the anti-tab side region Y. The configuration of the cap 60 is significantly simpler than those of the caps 2 and 40, and can be mass-produced at a lower cost. In addition, since the effect based on a structure common with the cap 2 is as having stated previously, description is abbreviate | omitted. Note that even if a weakening line having substantially the same configuration as the weakening lines 42a and 42b is provided in place of the weakening lines 20a to 20c, substantially the same effect as described above can be obtained.
[0054]
【Example】
The cap 2 having the form shown in FIGS. 1 to 6 was formed from low density polyethylene by injection molding. The main dimensions of the formed cap 2 are as follows (see FIGS. 3 to 6).
The minimum inner diameter d1 of the skirt wall 6 ... 40.6mm
Lower end inner diameter d2 of skirt wall 6 ... 41.0mm
Center inner diameter d3 of the locking protrusion 10 39.0 mm
Lower end inner diameter d4 of seal protrusion 8 ... 27.4mm
Upper end inner diameter d5 of seal protrusion 8 27.0 mm
Maximum outer diameter d6 of seal protrusion 8 ... 29.7mm
Upper end outer diameter d7 of the seal protrusion 8 28.7 mm
The outer diameter D1 of the lower end of the skirt wall 6 ... 42.8mm
The outer diameter D2 of the lower end of the rib 14 ... 43.4 mm
Upper end outer diameter D3 of the skirt wall 6 ... 42.4 mm
Cap 2 height h1 ... 11.5mm
Height h2 from the opening end of the rib 14... 7.0 mm
The center of the locking ridge 10 and the lower surface of the skirt wall 6
Distance h3 ... 6.65mm
Center of seal ridge 8 and bottom surface of skirt wall 6
Distance h4 ... 2.0mm
The lower end of the seal protrusion 8 and the lower surface of the skirt wall 6
Distance h5 ... 4.0mm
Thickness t1 of the first thin portion 22 ... 0.5 mm
Thickness t2 of second thin portion 24... 0.3 mm
Thickness t3 of top wall 4 ... 1.6mm
Between the circumferential ends of the tab 12
Tangential length T1 ... 24.0mm
At the center of the circumferential direction of the tab 12
Radially outward from the outer peripheral surface of the skirt wall 6
Length to the tip of the T2 ... 2.0mm
Of the rib 13 at the circumferential center of the tab 12
Of two ribs 13 arranged at equal intervals on both sides
Length T3 between opposing insides ... 14.4mm
Thickness T4 of each rib 13 ... 0.8mm
From the bottom of the tab 12 to the top of the rib 13
Height Th ... 4.0mm
Width W1 of weakening line 20 ... 3.0mm
(Width of the bottom of the groove 26)
Of weakening line 20
The circumferential width W2 on the radially outer side of the groove 26 ... 5.0 mm
Width W1 of weakening line 30 ... 1.2mm
(Width of the bottom of the groove 26)
Of weakening line 30
The circumferential width W2 on the radially outer side of the groove 26... 2.0 mm
Referring to FIG. 3, the circumferential angle of the region sandwiching the tab 12 between the weakening lines 30a and 30b is 80 ° (between the center of the tab 12 in the circumferential direction and the weakening line 30a and the tab 12). The circumferential angle between the center of the circumferential direction and the weakening line 30b is 40 °), and between the weakening lines 30a, 20a, 30c, 30e, 30g, 30f, 30d, 20b and 30b in the other regions. The circumferential angles are all 35 °.
The main dimensions of the milk bottle 100 to which the cap 2 is attached are as follows (see FIGS. 8 and 9).
Inner diameter d8 of the opening ... 28.9mm
Opening outside diameter D4 ... 41.0mm
Upper end of opening and lower surface of locked jaw 104
Distance h6 ... 7.0mm
The milk bottle 100 has a capacity of 213.5 ml.
Filling method:
200 ml of milk cooled to 5 ° C. is poured into the milk bottle 100 and the cap 2 is stoppered.
Test method:
Tests are performed in the order of the following (1) to (5), and wetting of the upper end surface of the opening of the milk bottle 100 and leakage of the cap 2 to the outside are confirmed at each stage.
(1) The milk bottle 100 is stored for 24 hours in an upright state in a temperature space maintained at 5 ° C.
(2) A 1G horizontal vibration and a vertical vibration are continuously applied for 30 minutes each in a vibration test machine (in a room temperature room).
(3) Store in a temperature space maintained at 5 ° C. for 24 hours while lying down.
(4) Store in a temperature space held at 40 ° C. for 6 hours in a lying state.
(5) Store in a temperature space maintained at 5 ° C. for 24 hours while lying down.
Test results:
Twenty milk bottles 100 with caps 2 plugged as described above were prepared, and the above test was performed on each of the milk bottles 100. Wetting (staining) was performed in all stages (1) to (5) above. No one was found to leak out) and the cap 2 was leaked outward, and all the desired good results were obtained.
[0055]
The preferred embodiments of the synthetic resin cap constructed according to the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments and departs from the scope of the present invention. Various modifications or corrections are possible. For example, in the above-described embodiment, each of the thin portions is formed in the first thin portion 22 having a relatively thick residual thickness and the lower region S2 near the opening end, which are formed in the upper region S1 near the top wall 4. In addition, the second thin portion 24 having a residual thickness smaller than that of the first thin portion 22 is formed, but the thin portion having the same residual thickness in the upper region S1 and the lower region S2 is formed. There is also a form. In the caps 2 and 40, the total number of weakening lines is not limited to any of the above embodiments.
[0056]
【The invention's effect】
The synthetic resin cap according to the present invention securely prevents the skirt wall from being broken at the time of stoppering and maintains a sufficiently secure sealed state with respect to the container opening so that the contents do not leak to the outside. Moreover, it can be easily detached from the opening of the container when manually opened. Furthermore, the synthetic resin cap according to the present invention is simple in structure and easy to mold, and therefore can be mass-produced at low cost.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a synthetic resin cap constructed in accordance with the present invention.
FIG. 2 is a front view of the cap shown in FIG. 1, with one side in the radial direction cut away from the axis.
3 is a bottom view of the cap shown in FIG. 1 as viewed from the end of the opening. FIG.
4 is an enlarged view of a part A in FIG. 3;
5 is a cross-sectional view taken along the line BB in FIG. 4;
6 is a cross-sectional view taken along the line CC in FIG. 2;
FIG. 7 is a diagram in which a part of a mold is entered in FIG.
FIG. 8 is a front view showing a state where the cap shown in FIG.
9 is an enlarged cross-sectional view of a broken portion of FIG. 8 (cap is a broken portion shown in FIG. 5).
FIG. 10 is a partial view of another embodiment of a synthetic resin cap configured according to the present invention as viewed from the open end side.
11 is a cross-sectional view taken along the line DD in FIG.
FIG. 12 is a bottom view of still another embodiment of the synthetic resin cap constructed according to the present invention as viewed from the open end side.
FIG. 13 is a bottom view of still another embodiment of the synthetic resin cap constructed according to the present invention as viewed from the open end side.
[Explanation of symbols]
2 Plastic cap
4 Top wall
6 Skirt wall
8 Seal protrusion
10 Locking ridge
12 tabs
13 Ribs
14 Ribs
20 (a and b) Weakening line consisting of relatively wide thin part
22 First thin part
24 Second thin part
26 Groove
30 (ag) Weak line consisting of a relatively narrow thin part
40, 50 Synthetic resin cap
100 milk bottle
102 opening
104 Locked jaw
S1 Upper area
S2 Lower area
W1 circumferential width of thin part
W2 The circumferential width on the outer side in the radial direction of the groove 26
W3 Circumferential width inside the groove 46 in the radial direction
X Tab side area
Y Anti-tab side area

Claims (7)

The top surface wall and a skirt wall extending downward from the periphery of the top surface wall, and the inner peripheral surface of the skirt wall is locked to a locked jaw portion formed on the outer peripheral surface of the container opening In a synthetic resin cap in which a ridge is formed and a tab protruding radially outward is formed over a partial region in the circumferential direction on the outer peripheral surface at the opening end of the skirt wall,
When the skirt wall is viewed in the axial direction, the tab side is positioned substantially in the center of the skirt wall at a 180 ° tab side region X of the skirt wall and another 180 ° anti-tab side region Y of the skirt wall. When divided, the skirt wall of the tab side region X is formed with two weakening lines spaced apart in the circumferential direction, and each of the weakening lines is relatively wide extending from the open end toward the top wall. These thin portions have a circumferential width of 2.5 mm to 5.0 mm,
Further, a plurality of weakening lines are formed in the skirt wall at intervals in the circumferential direction, and each of the weakening lines is composed of a relatively narrow thin portion extending from the opening end toward the top surface wall. The part has a circumferential width of 0.5 mm to 1.8 mm,
A weakening line consisting of a pair of relatively narrow thin portions is arranged adjacent to both sides in the circumferential direction of the tab and at equal intervals from both sides of the tab, and a weakening line consisting of a relatively wide thin portion is It is located farther from the tab than the weakening line consisting of a relatively narrow thin part on both sides of the tab, and is arranged at equal intervals from both sides of the tab.
A synthetic resin cap. The synthetic resin cap according to claim 1, wherein an annular seal protrusion is formed on the inner surface of the top wall so as to extend downward and be fitted to the inner peripheral surface of the container opening. The synthetic resin cap according to claim 1 or 2 , wherein a plurality of the relatively narrow thin portions are formed at intervals in the circumferential direction on the skirt wall of the anti-tab side region Y. . In the skirt wall of the anti-tab side region Y, one weakening line is formed substantially diametrically opposite to the circumferential center position of the tab, and the weakening line extends from the opening end to the top wall. The synthetic resin cap according to any one of claims 1 to 3 , comprising a thin portion extending toward the surface. The thin-walled portion is formed in the upper region near the top wall and has a relatively thick first thin-walled portion, and the first thin-walled portion formed in the lower region near the opening end. The synthetic resin cap according to any one of claims 1 to 4 , comprising a second thin portion having a small thickness. Each of the thin wall portions includes a groove formed so as to extend linearly over the entire axial direction of the outer peripheral surface of the skirt wall, and the second thin wall portion is positioned below the locking protrusion. The synthetic resin cap according to claim 5 , wherein the inner peripheral surface of the lower end portion on the opening end side is positioned on the same plane as the corresponding inner peripheral surface of the lower end portion of the skirt wall. The synthesis according to claim 6 , wherein the first thin portion has a thickness of 0.35 mm to 0.6 mm, and the second thin portion has a thickness of 0.15 mm to 0.3 mm. Resin cap.

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