JPH11147551A - Cap excellent in capping ability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic cap excellent in both capping ability and TE ability and a combination of the cap and a container. SOLUTION: A combination of a cap and a container comprises the container having a mouth having a threaded line along an outer periphery and a large diameter bead formed below the threaded line and the cap 2 screwed and fixed onto the container, wherein the cap comprises a top plate, a skirt including a threaded line on an internal face and a TE band provided at a lower end of the skirt via a breakable bridge while a plurality of flexible flap pieces oriented inward and upward are formed on an internal face of the TE band at constant intervals along a circumferential direction. At least one cam 7 including a tapered face 7a which can be in contact with a tip of the flap piece 20 at the time of opening the cap 2 is formed on a lower face of the bead of the container mouth, and a tapered face 20a with approximately the same gradient angle as a tapered angle of the tapered face of the cam is formed at a tip of the flap piece 20 on a side to be in contact with the tapered face of the cam at the time of opening the cap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic cap having excellent tamper-evident properties and capping properties, and a combination of the cap and a container. More specifically, the present invention relates to a tamper for proving the opening history of a cap. The present invention relates to a combination of a plastic cap provided with an evidence band and a container provided with a mouth to which the cap is screwed.

[0002]

2. Description of the Related Art Caps provided with a tamper-evidence band (hereinafter sometimes referred to as TE band) for proving the opening history of the cap are well known and widely used for containers of various seasonings, beverages and the like. . In this cap, T
The E band is provided at the lower end of the cap skirt via a breakable bridge, and the inner surface of the TE band is provided with a projection that engages with the outer surface of the container mouth.
In other words, when the cap is opened, the protrusion of the TE band engages with the outer surface of the container mouth, and the rise of the TE band is prevented, so that only the cap body above the TE band rises,
The bridge connecting the E band and the cap skirt is broken. Therefore, the TE band has fallen off the cap removed from the container opening, and this fact proves the history of opening the cap.

By the way, in a combination of a cap and a container of a type which is screwed to a container mouth, the above-mentioned T
A device using a ratchet mechanism in order to impart E characteristics is known. As examples of such a combination of a cap and a container, FIGS. 1 to 3 of Japanese Patent Publication No. 3-56990 show a screw (4) and a plurality of cams (locking claws) on the outer surface of the container mouth. 8) and a TE band (20) provided through a break line (16)
A combination with a cap provided with a locked claw (36) on the inner surface of is disclosed. When the cap of this prior art is turned in the opening direction, the locked claw of the TE band abuts on the cam of the container mouth, so that the turning of the TE band is prevented, so that the breaking line is broken, With the TE band dropped off, the cap is removed from the container opening. Particularly, in this combination, since the taper surface (46) is formed on the cam of the container mouth portion, and the locked claw of the TE band abuts on this taper surface, the cap is opened. When swung in the direction, the TE band is pushed down due to the contact between the locked claw and the tapered surface of the cam, so that the line is reliably broken without causing the TE band to slip through. Thus, there is an advantage that the TE band comes off from the cap and the TE property is extremely excellent.

On the other hand, the above-mentioned prior art cap has a drawback that the capping torque when the cap is attached to the container mouth (capping) is extremely high. That is, when the cap is turned in the closing direction, the locked claw on the inner surface of the TE band must ride over the cam, and therefore the closing torque increases. When the stopper torque increases,
The stress applied to the breaking line connecting the TE band and the cap is increased, and as a result, the trouble often occurs that the breaking line is broken at the time of capping. That is, poor capping properties and low productivity are disadvantages of the above prior art.

In order to increase the capping property by lowering the closing torque, it is conceivable to provide a flexible flap piece instead of the above-mentioned locked claw. That is, a flexible flap piece that is directed inward and upward is provided on the inner surface of the TE band, and at the time of opening, the upper end portion of this flap piece contacts the tapered surface of the cam of the container opening. Similarly, the turning of the TE band in the opening direction is prevented, so that the TE band falls off the cap to be opened. At the time of capping, such a flexible flap piece can easily get over the cam as compared with the above-mentioned locked claw, so that the closing torque is small, and
Breakage of the connection between the E-band and the cap can be effectively prevented, and capping properties can be improved.

[0006]

However, when a flexible flap piece is used, there is a problem that the TE property is reduced. That is, when opening the cap,
When the flap piece comes into contact with the tapered surface of the cam, the flap piece is flexible and easily deformed, so it buckles and deforms at the base of the flap piece, and as a result, the TE band tends to slip through. It will be. To solve this problem, the strength of the flap piece may be increased by manufacturing the cap using a relatively rigid plastic. In this case, the connecting portion between the TE band and the cap is easily broken, and the capping property is reduced. That is, the meaning of using the flap pieces for reducing the plugging torque is lost. In addition, rigid plastics have low toughness and cracks and the like are easily generated in the cap itself. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a plastic cap having excellent capping properties as well as TE properties, and a combination of the cap and a container.

[0007]

According to the present invention, a top plate portion, a skirt portion provided with a thread on its inner surface to be screwed with a container mouth portion, and a breakable bridging portion at the lower end of the skirt portion are provided. And a plurality of flexible flap pieces directed inward and upward are formed at regular intervals in the circumferential direction on the inner surface of the tamper-evident band. In a plastic cap, there is provided a cap characterized in that an inclined tapered surface is formed at a tip portion of the flap piece.
According to the present invention, there is provided a container having an opening having a thread on the outer periphery thereof, and a bead having a large diameter formed below the thread of the mouth, and a screw fixed to the container. The cap comprises a top plate portion, a skirt portion having a thread on the inner surface thereof, and a tamper evidence band provided at a lower end of the skirt portion via a breakable bridging portion. On the inner surface of the tamper-evidence band, a combination of a cap and a container in which a plurality of flexible flap pieces pointing inward and upward are formed at regular intervals in the circumferential direction, At least one cam having a tapered surface that can come into contact with the tip portion of the flap piece when the cap is opened is formed on the lower surface of the bead portion of the container mouth, and the tip portion of the flap piece has a cap. When opened The tapered surface abutting a side of said cam, a combination of a cap and a container, wherein a tapered surface having substantially the same inclination angle as the taper angle of the tapered surface of the cam is formed is provided.

It is a very important feature of the present invention that a taper surface having the same taper angle as that of the cam is provided on the side of the upper end of the flap piece which comes into contact with the cam. That is, since the contact force between the flap piece and the cam at the time of opening the cap is dispersed on the tapered surface of the flap piece, the stress is relieved. Therefore, buckling deformation at the base of the flap piece is effectively prevented, and the cap is opened. At this time, the TE band is prevented from slipping through. For this reason, it is not necessary to increase the strength of the flap pieces more than necessary. As a result, it is possible to improve the TE property while maintaining the capping property, without increasing the closing torque.

Further, in the present invention, by providing the flap pieces with a tapered surface, the length in the circumferential direction of each flap piece root can be set to be large, and the allowable width of design can be widened.
The strength against the stress in the shear direction can be increased, which is more advantageous in preventing the buckling deformation described above.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to specific examples shown in the accompanying drawings. FIG. 1 is a half sectional side view of a plastic cap of the present invention, and FIG. 2 is a side view showing a preferred example of a container to which the cap is applied.
FIG. 3 is a bottom view of the cap of FIG. 1, and FIG.
FIG. 7 is a view showing a part of a flap piece provided on the cap of FIG. FIG. 5 is a diagram showing an engagement state between the flap piece of FIG. 4 and a cam formed on the container,
FIG. 6 is a diagram showing an engagement state between a comparative flap piece and a cam.

1 and 2, reference numeral 1 denotes a container mouth, and reference numeral 2 denotes a cap. A screw 5 is formed on the outer surface of the container opening 1, a large-diameter bead 6 is formed below the screw 5, and a plurality of beads (see FIG. 1 are four). On one side of the cam 7, a tapered surface 7a is formed.
The tapered surface 7a has a function of pushing down a flap piece described later that comes into contact with the tapered surface 7a, and has a function as a so-called cam. The taper angle θ of the tapered surface 7a is not particularly limited, but is about 25 ° in FIG. The number of the cams 7 is arbitrary, and may be, for example, one. However, as shown in FIG.
It is preferable to arrange the cams 7 symmetrically.

The cap 2 includes a top plate 10 and a skirt 1
1 and a skirt 11 via a breakable bridge 12
And a TE band 13 connected to a lower end of the TE band. A sealing liner 15 is provided on the inner peripheral edge of the top plate 10.
Is provided, and the liner 15 is in close contact with the upper end of the container opening 1 to ensure a sealed state of the container. A screw 16 is formed on the inner surface of the skirt 11, and the screw 16 is screwed with the screw 5 of the container opening 1, whereby the cap 2 is fixed to the container opening 1. Also T
On the inner surface of the E-band 13, a number of flexible flap pieces 2 are provided.
Zeros are provided at regular intervals. These flap pieces 2
0 is directed inward and upward, and when the cap 2 is closed by capping, the cap 2 is located below the bead portion 6 of the container opening 1 and the cap 2 is rotated in the opening direction.
The flap piece 20 comes into contact with the tapered surface 7a of the cam 7, and the turning of the TE band 13 is prevented. At the same time, the TE band 13 (flap piece 20) is pushed down.
Accordingly, the bridge 12 connecting the TE band 13 and the cap 2 is broken, and the cap 2 is lifted and removed from the container opening 1, but the TE band 13 is separated from the cap 2 and the container opening 1 is closed. Remains around.

In the present invention, the flap piece 20 preferably has a thick upper end and a thinner base. That is, by reducing the thickness of the base portion, the flap piece 20 can be given appropriate flexibility to reduce the plugging torque at the time of capping. In addition, by making the upper end portion thick, the contact engagement force between the flap piece 20 and the tapered surface 7a of the cam 7 (hereinafter, sometimes referred to as a cam tapered surface) is increased, and the bridge 12 is quickly moved.
Can be broken. In this case, the thickness of the flap piece 20 gradually increases from the base to the upper end in order to facilitate the climbing of the flap piece 20 onto the bead portion 6 and the cam 7 at the time of capping and to reduce the closing torque. It is preferable that the thickness increases. The thickness of the base of the flap piece 20 for imparting appropriate flexibility varies depending on the type of plastic forming the cap, but is usually preferably about 0.35 to 0.65 mm, and the thickness of the upper end is It is preferable that the thickness is about 1.3 to 2.5 times the thickness of the base.

According to the present invention, the cam taper surface 7 at the upper end of the flap piece 20 is clearly shown in FIG.
A tapered surface 20a (hereinafter, sometimes referred to as a flap tapered surface) is formed on the contact side with a. The taper angle (indicated by α in FIG. 3) of the flap taper surface 20a is set substantially equal to the taper angle θ of the cam taper surface 7a. That is, when the cap 2 is opened, the flap taper surface 20a comes into surface contact with the cam taper surface 7a. The length r of the flap taper surface 20a is preferably set to 2.0 mm or more. The function of the flap taper surface 20a will be described with reference to FIGS.

First, FIG. 6 shows a comparative example, in which the flap pieces 2
0 'is rectangular and has no tapered surface.
In the case of such a flap piece 20 ', as shown in FIG. 6, when the cap 2 is rotated in the opening direction, the corner portion P of the flap piece 20' comes into contact with the cam tapered surface 7a. Therefore, stress is concentrated on the corner P, and the flap piece 20 'is easily deformed.
Causes a large stress locally. Therefore, the buckling deformation of the flap piece 20 ′ easily occurs due to the contact with the cam taper surface 7 a at the time of opening, and the TE band easily slips through.

FIG. 5 shows an example of the present invention. When the tapered surface 20a is formed on the flap piece 20, the flap tapered surface 20a and the cam tapered surface 7 when the plug is opened are opened.
a is a surface contact, the flap taper surface 2
A stress will be generated in the entirety of Oa. Therefore, since the stress is dispersed and the stress applied to the base portion Q of the flap piece 20 is also dispersed, the flap piece 20 of the present invention is less susceptible to buckling deformation than the flap piece 20 ′ of FIG. It will be appreciated that the resistance is extremely high. Therefore, as described above, the upper end of the flap piece 20 is made thicker, but it is not necessary to make the whole thicker, and buckling deformation can be prevented without making the flap piece extremely thick. This is advantageous in that the weight per unit area can be reduced. Moreover, the tapered surface 20a acts as a guide during capping, so that the flap piece 20 can easily ride on the bead portion 6 and the cam 7, and the length of the thickest upper end portion becomes short, so that the plug is closed. The torque can be reduced by about 2 kgf-cm.

In the present invention, as long as the tapered surface 20a is formed, the shape of the flap piece 20 is not particularly limited. For example, a rectangular flap piece may have a shape obtained by cutting the upper end corner. Normally, as shown in FIGS. 4 and 5, the upper bottom corner of the trapezoidal flap piece is cut to form a tapered surface. Can be set large, which is advantageous in increasing the strength.

For example, as shown in FIGS. 5 and 6, when the cap 2 is closed, the flap pieces 20, 20 'are closed.
Part of the vehicle runs on the cam 7. 5 and 6, the flap piece riding on the cam 7 is
x, 20y. By the way, even when the TE band 13 is rotated, such flap pieces 20x and 20y do not return to the original shape and move in the same shape as when riding, so that they do not come into contact with the cam taper surface 7a. Therefore,
In the closed state, unless at least one flap piece 20 that does not ride on the cam 7 exists between the adjacent cams 7, 7, the flap piece 20 does not function effectively, and the flap when opening is opened. Piece 20 and cam taper surface 7
The bridge 12 cannot be broken due to the contact with a. For this reason, the circumferential length of the flap piece 20 is limited.

That is, as shown in FIG. 6, the length of the upper side of the rectangular flap piece 20 ′ having no tapered surface is considerably longer than the distance d between the adjacent cams 7. Must be set small,
Similarly, the length of the lower piece of the flap piece 20 '(the length of the base Q) must be set smaller than the distance d.
As described above, when the rectangular flap pieces 20 ′ are used, the size of the flap pieces 20 ′ is severely restricted, and the allowable width of the design is extremely narrow. Moreover, the flap piece 2
The fact that the length of the root portion Q of 0 ′ cannot be set large cannot increase the strength of the root portion Q of the flap piece 20 ′, which is disadvantageous in terms of buckling resistance.

On the other hand, as shown in FIG. 5, in the flap piece 20 having the tapered surface 20a, even if the length of the upper end is set small, the length of the base Q can be set large. it can. In particular, when the upper bottom of the trapezoidal piece is cut out to form a tapered surface, the length of the root portion Q can be set to be longer. That is, according to the present invention, not only the allowable width of the size of the flap piece 20 is large and the degree of freedom of design is large, but also the strength of the root portion Q of the flap piece 20 can be increased and the buckling deformation resistance is also improved. This is advantageous.

That is, in the present invention, the above-described flap piece 2
The size of 0 and the number thereof are such that when the cap is closed, at least one flap piece 20 not riding on the cam 7 is formed.
It should be set so that there is at least one flap piece 20 that does not ride on the cam 7 between each adjacent cam 7.

Table 1 below shows the pressures at which buckling deformation occurs when a shear pressure is applied to the cap provided with the TE band having the flap pieces of various shapes from the contact side of the flap piece with the cam taper surface. The result of measuring (shear strength) is shown. This measurement was performed at a temperature of 23 ° C. and 40 ° C. The measured value was shown as an average value of five measurements. From the results shown in Table 1, it can be seen that, in the present invention, the shear strength is higher by 2 kgf-cm or more and the buckling resistance is improved as compared with the case where the flap taper surface is not formed.

[0023]

[Table 1]

In the present invention described above, the resin used for molding the cap includes various plastics, for example, low-, medium- or high-density polyethylene, linear low-density polyethylene, polypropylene, thermoplastic polyester, polyamide, and styrene-based resin. Resins, ABS resins and the like.
As the container, containers made of various synthetic resins known per se, for example, a bottle made of polyethylene terephthalate can be used.

[0025]

According to the present invention, the buckling deformation resistance can be improved without impairing the flexibility of the flap piece provided on the inner surface of the TE band. Excellent in productivity, extremely high productivity, and also effectively prevents the TE band from slipping off when the cap is opened, and is excellent in TE property. Further, since it is not necessary to make the flap pieces extremely thick, it is advantageous in that the weight per unit area of the resin can be reduced. Further, by forming a tapered surface on the flap piece, the length of the root portion of the flap piece can be set large, which is not only extremely advantageous in buckling resistance but also the size and number of flap pieces. There is an advantage that the allowable range of the interval and size of the cams is large and the degree of freedom in design is high.

[Brief description of the drawings]

FIG. 1 is a half sectional side view showing a plastic cap of the present invention.

FIG. 2 is a side view showing a container opening to which the cap of FIG. 1 is applied.

FIG. 3 is a bottom view of the cap of FIG. 1;

FIG. 4 is an expanded view showing a part of a flap piece provided on the cap of FIG. 1;

FIG. 5 is a diagram showing an engagement state between a flap piece of FIG. 4 and a cam formed on a container.

FIG. 6 is a diagram showing an engagement state between a comparative flap piece and a cam.

[Explanation of symbols]

 1: Container mouth 2: Cap 6: Bead 7: Cam 7a: Tapered surface 12: Bridge 13: TE band 20: Flap piece 20a: Tapered surface

Claims (6)

[Claims] 1. A top plate portion, a skirt portion provided with a thread threadedly engaged with a container mouth portion on an inner surface thereof, and a tamper evidence band provided at a lower end of the skirt portion via a breakable bridging portion. The inner surface of the tamper-evidence band,
In a plastic cap in which a plurality of flexible flap pieces directed inward and upward are formed at a constant interval in a circumferential direction, an inclined tapered surface is formed at a tip portion of the flap piece. A cap characterized by being. 2. The cap according to claim 1, wherein a tip portion of the flap piece is formed thicker than a root portion thereof. 3. A container provided with a mouth having a thread on the outer periphery thereof, and a large-diameter bead portion is formed below the thread of the mouth, and the container is screwed to the container. A plastic cap, the cap comprising a top plate portion, a skirt portion having a thread on an inner surface thereof, and a tamper evidence band provided at a lower end of the skirt portion through a breakable bridge portion, On the inner surface of the tamper evidence band,
In a combination of a cap and a container in which a plurality of flexible flap pieces pointing inward and upward are formed at a constant interval in the circumferential direction, a bead portion lower surface of the container mouth portion has a cap At least one cam having a tapered surface that can come into contact with the tip portion of the flap piece when the cap is opened is formed on a side of the tip portion of the flap piece that comes into contact with the tapered face of the cam when the cap is opened. A combination of a cap and a container, wherein a taper surface having an inclination angle substantially the same as the taper angle of the taper surface of the cam is formed. 4. The combination of a cap and a container according to claim 3, wherein the flap piece has a thicker tip portion than a root portion thereof. 5. The cap and container combination according to claim 3, wherein at least one of the flap pieces does not ride on the cam when the cap is closed. 6. The cam according to claim 3, wherein a plurality of the cams are formed, and at least one flap piece that does not ride on the cam exists between the adjacent cams when the cap is closed. Combination of cap and container.