JP2002264962A - Synthetic resin cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin cap excellent in tamper evidence. SOLUTION: This cap comprises a cap body 4 having a top plate part 2 and a cylindrical art 3 and a packing 5 provided in the cap body 4, this packing 5 has a bottom plate part 12 and a cylindrical part 13, a top plate inner surface projection 15 is formed on an inner surface of the top plate part 2, a packing locking projection 17 is formed on an outer face of the top plate part inner surface projection 15, a locking projecting part 16 to be locked to the packing locking projection 17 is formed on an inner face of the cylindrical part 13 of the packing 5, and the distance A in the vertical direction between the locking projecting part 16 of the packing 5 and the packing locking projection 17 is set to be not less than the bridge cutting angle (cap turning angle before breaking a bridge 7 when opening the cap)/360×(pitch B of the thread 10).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin cap for closing a mouth of a container, and more particularly to a synthetic resin cap excellent in tamper evidence.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a conventional synthetic resin cap.
Is provided with a cap body 4 having a top plate portion 2 and a cylindrical portion 3 hanging down from the periphery thereof, and a packing 25 provided in the cap body 4. The cylindrical portion 3 is divided into an upper main portion 8 by a horizontal score 6 and a TE ring portion 9 connected to the main portion 8 by a bridge 7. On the inner wall surface of the main part 8, a screw part 10 to be screwed with a male screw of the container mouth part is formed. A wing 11 is provided on the inner wall surface of the TE ring portion 9 to lock the container when the cap 31 is opened. The packing 25 is made of a soft synthetic resin material, and has a bottom plate 12, a cylindrical portion 13 extending upward from a peripheral edge of the bottom plate 12, and a radially outward extending from an upper end of the cylindrical portion 13. And a projected flange portion 24. Screw part 10
On the inner surface of the main part 8 above the upper end, the packing locking projection 1 is provided.
8 are provided.

The cap 31 is turned over the container opening 21a in the closing direction, and the screw portion 10 is screwed onto the male screw 22 of the container. At this time, the bottom plate portion 12 and the cylindrical portion 13 of the packing 25 are fitted into the container opening 21a, and the
Open end 2 in a state where is sandwiched between container opening 21a and top plate 2.
1c, and the cylindrical portion 13 is the inner wall surface 2 of the container opening 21a.
The container opening 21a is hermetically sealed by being in close contact with 1b. In a state where the cap 1 is attached to the container mouth portion 21a (closed position), the wing 11 provided on the inner surface of the TE ring portion 9 is an annular bulging step portion 23 provided immediately below the male screw 22 of the container 21. Located at the bottom of.

[0004] The cap 31 attached to the container mouth 21a
When the is rotated in the opening direction, the wing 11 provided on the inner surface of the TE ring portion 9 is engaged with the lower part of the bulging step 23 of the container opening 21a, so that the main portion 8 of the cap body 4 rises as it rotates. On the other hand, the TE ring portion 9 is prevented from moving upward, and as a result, the main portion 8 of the cap 1 and the TE ring portion 9
A tensile force acts on the bridges 7 connecting the two, and the bridges 7 are broken, and the TE ring portion 9 is separated from the main portion 8. By separating the TE ring 9,
It can be clearly indicated that the cap 1 has been opened.
In this opening process, as the main portion 8 of the cap body 4 rises as it rotates, the packing locking projection 18 on the inner surface of the main portion 8 pushes up the peripheral edge portion 24a of the flange portion 24,
As a result, the packing 25 moves upward, the bottom plate portion 12 and the cylindrical portion 13 are pulled out from the container opening 21a, and the sealing is released.

[0005]

In a cap having this kind of tamper-evident property, when the cap attached to the container mouth is turned in the opening direction, the opening end of the container mouth becomes the inner surface of the cap, packing or the like. The rotation angle of the cap until the container is released from the container (the seal release angle (seal release angle); hereinafter, referred to as SRA)
And the difference (S.R.A.B.B.B.) between the cap rotation angle from the capping position until the bridge is cut off (bridge cutting angle (bridge break angle); hereinafter referred to as BBA).
It is considered that A) is desirably 0 degrees or more, preferably +30 degrees or more. That is, when the cap is opened, it is desirable that the bridge be cut before the opening end of the container mouth is separated from the packing or the like and the sealing is released. However, in the above-mentioned synthetic resin cap, when the bridge 7 made of synthetic resin expands and deforms when the cap is opened, BBA increases, and SRAB increases.
B.A sometimes becomes smaller, and improvement has been demanded from the viewpoint of tamper evidence. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a synthetic resin cap having excellent tamper evidence.

[0006]

In the cap made of synthetic resin of the present invention, an inner surface projection of the top plate extending downward is formed on the inner surface of the top plate, and the inner projection of the top plate protrudes outward. When the packing main body is moved upward on the inner surface of the cylindrical portion, the packing locking projection is formed, and the packing has a bottom plate portion and a cylindrical portion extending upward from the peripheral edge of the bottom plate portion. A locking protrusion that locks to the packing locking protrusion is formed on the packing, and the packing can move up and down from the raised position where it contacts the top plate to the lowered position where the locking protrusion contacts the packing locking protrusion. The vertical distance between the packing locking projection and the packing locking projection at the raised position is the bridge cutting angle / 3.
It is characterized in that the pitch is equal to or more than 60 × the pitch of the thread portion. It is preferable that the vertical distance between the locking projection and the packing locking projection is equal to or less than bridge cutting angle / 360 × thread pitch + pitch / 2.

[0007]

1 and 2 show an embodiment of a synthetic resin cap according to the present invention. The synthetic resin cap 1 shown here hangs from a top plate 2 and its periphery. A cap body 4 having a cylindrical portion 3 and a packing 5 provided in the cap body 4 are provided. The cylindrical portion 3 is divided into an upper main portion 8 by a horizontal score 6 and a tamper evidence ring portion (TE ring portion) 9 connected to a lower end of the main portion 8 by a number of narrow bridges 7. On the inner peripheral wall surface of the main portion 8, a screw portion 10 is formed which is screwed into a male screw 22 formed on a mouth 21a of a container 21 to which the cap 1 is attached. TE ring part 9
A wing 11 is provided on the inner wall surface of the wing 11 as a locking means for locking the bulging step 23 of the container 21 to prevent the movement of the TE ring 9 when the cap 1 is opened. The wing 11 is formed in an undulating plate shape.

On the inner surface of the top plate 2, a cylindrical top plate inner surface projection 15 is formed so as to protrude downward. On the outer surface of the top plate inner surface protrusion 15, a packing locking protrusion 17 that projects annularly outward in the radial direction is formed. The protrusion length of the packing locking projection 17 is 0.1 to 2 mm.
(Preferably 0.2 to 1 mm).
If the projection length is less than the above range, the locking projection 1
If the packing 5 exceeds the above range, the operation of attaching the packing 5 to the inside of the cap body 4 when manufacturing the cap 1 becomes difficult, which is not preferable. The cap body 4 is formed of a synthetic resin such as polyethylene and polypropylene.

The packing 5 is made of a relatively soft synthetic resin material, and has a bottom plate 12 having an outer diameter fitted into the container mouth, and a cylindrical shape extending upward from the periphery of the bottom plate 12 in a cylindrical shape. It has a portion 13 and a flange portion 14 extending radially outward from the upper end of the tubular portion 13. The bottom plate portion 12 is composed of a central portion 12a and an outer peripheral portion 12b whose diameter gradually increases upward from the peripheral edge, and has a thickness of 0.1 to 2 mm.
It is preferred that The outer diameter of the cylindrical portion 13 is
Is preferably set to be substantially equal to or slightly larger than the inner diameter of the container opening to be mounted. Tubular part 1
The thickness of 3 is preferably 0.5 to 3 mm. The flange portion 14 extends radially outward from the upper end of the tubular portion 13 horizontally and an inner peripheral portion 14a and extends downward from the outer peripheral edge of the inner peripheral portion 14a in the radially increasing direction. And an outer peripheral portion 14b. The widths of the inner peripheral portion 14a and the outer peripheral portion 14b are appropriately set in accordance with the dimensions of the opening end of the container opening to which the cap 1 is to be mounted. The thickness of the flange 14 is 0.5 to
It is preferably 3 mm.

On the inner surface of the upper end of the cylindrical portion 13, there is provided a locking projection 16 which projects annularly inward in the radial direction. The locking projection 16 is formed such that its inner diameter is smaller than the outer diameter of the packing locking projection 17 of the top plate inner surface projection 15, and when the cap body 4 is moved upward with respect to the packing 5. Can be locked to the packing locking projection 17. The projecting length of the locking projection 16 is 0.1 to 2
mm (preferably 0.2 to 1 mm). If the projection length is less than the above range, it is difficult for the locking projection 16 to lock to the packing locking projection 17. On the other hand, if the protrusion length exceeds the above range, it is difficult to mount the packing 5 in the cap body 4 when manufacturing the cap 1, which is not preferable. The width of the locking projection 16 is
It is preferable that the thickness be 0.2 mm or more (preferably 0.2 to 1 mm). If the width is less than the above range, the mechanical strength of the locking projection 16 decreases, and the locking projection 16 becomes difficult to lock to the packing locking projection 17.

[0011] Packing locking projection 1 of top plate inner surface projection 15
Reference numeral 7 is formed at a position separated from the locking projection 16 when the flange 14 of the packing 5 is at a position where the flange 14 comes into contact with the top plate 2 (the position shown in FIG. 1). For this reason, as shown in FIG. 2, the packing 5
Is in the ascending position where it contacts the top plate 2 (the position indicated by the solid line in the figure)
From above, the locking projection 16 can be moved up and down to a lowering position (a position indicated by a two-dot chain line in the figure) where the locking projection 16 comes into contact with the packing locking projection 17.

In the cap 1 of this embodiment, the height of the packing locking projection 17 is the vertical distance A (from the lower surface of the locking projection 16 to the upper surface of the locking projection 17) with respect to the locking projection 16 at the raised position. Is set to be BBA (bridge cutting angle) / 360 × the pitch B of the threaded portion 10 or more. BBA is Cap 1
When turning in the opening direction from the closing position (the position shown in FIG. 1),
It refers to the rotation angle of the cap 1 until the bridge 7 breaks. The pitch B indicates a difference in height between the vertically adjacent screw portions 10. If this vertical distance A is less than the above range, the sealing release is earlier than at the time of opening the plug compared to the bridge cutting,
Tamper evidence decreases.

The height position of the packing locking projection 17 is as follows.
It is preferable to set the vertical distance A to be equal to or less than (BBA / 360 × B) + B / 2. Vertical distance A
Exceeds this range, the rotation angle of the cap 1 until the seal is released becomes too large, and the operability decreases.

The cap 1 can be manufactured by separately molding the cap body 4 and the packing 5 by compression molding or the like, and pressing the packing 5 into the obtained cap body 4 for mounting.

The operation of the cap 1 will be described below with reference to FIGS. Cap 1 into container opening 21
a, the bottom plate 12 and the cylindrical portion 13 of the packing 5 are fitted into the container opening 21a. The inner peripheral portion 14a of the flange portion 14 is connected to the open end 21c of the container mouth portion 21a and the top plate portion 2.
And tightly adheres to the opening end 21c to seal this portion. The outer peripheral portion 14b of the flange portion 14 is sandwiched between the outer peripheral edge 21d of the opening end 21c and the inclined surface 2a of the top plate portion 2, closely adheres to the outer peripheral edge 21d, and seals this portion. The cylindrical portion 13 is in close contact with the inner wall surface 21b, and seals this portion. Thereby, the container mouth 21a is sealed. In addition, the wing 11 provided on the inner surface of the TE ring portion 9 rides over the annular bulging step 23 provided immediately below the male screw 22 of the container 21 and reaches below the bulging step 23.

When the cap 1 is mounted on the container opening 21a, the flange 14 of the packing 5 is in contact with the top plate 2, and the packing locking projection 17 of the top plate inner surface projection 15 is The packing 5 is separated from the locking projection 16 (the state shown in FIG. 1).

When the cap 1 attached to the container opening 21a is turned in the opening direction, the cap body 4 rises as it rotates. At this time, since the wing 11 provided on the inner surface of the TE ring portion 9 is engaged with the lower portion of the bulging step portion 23 of the container opening 21a, the main portion 8 of the cap body 4 rises with rotation, while the TE ring portion is raised. 9 is prevented from moving upwards,
As a result, a tensile force acts on the bridge 7 connecting the main part 8 of the cap 1 and the TE ring part 9, the bridge 7 is broken, and the TE ring part 9 is separated from the main part 8.
The separation of the TE ring 9 clearly indicates that the cap 1 has been opened.

In the opening process, the cap body 4
Is raised, the locking projections 17 of the top plate inner surface projections 15 are also raised, but the locking projections 17 are separated from the locking projections 16 of the packing 5 at the beginning of the opening process. Therefore, almost no upward push-up force acts on the packing 5, and the packing 5 remains in a state where the flange portion 14 is in contact with the opening end 21c. In the opening process, the rising distance of the cap body 4 with respect to the rotation angle of the cap body 4 is pitch B
Will be a value corresponding to. For example, when the cap body 4 is rotated once, the cap body 4 rises by the pitch B.

When the cap body 4 rises by the vertical distance A, the locking projections 17 of the top plate inner surface projections 15 come into contact with the locking projections 16 of the packing 5. When the cap body 4 is further rotated, the packing locking projection 17 is moved to the locking projection 16.
Is pushed upward, the bottom plate portion 12 and the cylindrical portion 13 are pulled out from the container opening 21a, and the packing 5 is moved to the container opening 21.
The seal is released away from a.

In the cap 1 of this embodiment, the packing 5
Is movable up and down with respect to the cap body 4,
Locking projection 16 and packing locking projection 17 in the raised position
Is the vertical distance A between (BBA / 360 x pitch B)
Since the setting is made as described above, the rotation angle SRA until the sealing is released in the opening process can be set to an appropriate value. For example, if BBA is 180 degrees, the vertical distance A is 180/360 × B = 0.5 × B
That is all. The pitch B is the rotation angle 36 of the cap body 4
Since the angle corresponds to 0 degrees, the cap body 4 is vertically
The rotation angle of the cap body 4 when the cap body 4 is moved upward by only 0.5 × 360 = 180 degrees or more. For this reason, in the opening process, the packing locking projection 17 of the top plate inner surface projection 15 is locked to the locking projection 16 of the packing 5 after the bridge 7 is broken. Therefore, the sealing release in the opening process can be sufficiently delayed compared to the bridge cutting, and the tamper-evident property can be improved.

Further, the vertical distance A is set to (BBA / 3
60 × B) + B / 2 or less, excellent operability can be obtained. For example, when BBA is 180 degrees, the rotation angle of the cap body 4 when the cap body 4 moves upward by the vertical distance A is 180 degrees.
+ 180 = 360 degrees or less. Therefore, the bridge 7
The packing locking projections 17 are locked to the packing 5 from the time when is broken to the time when the cap body 4 is rotated half a turn. Therefore, the rotation angle of the cap main body 4 until the sealing is released can be suppressed to an appropriate value, and a decrease in operability can be prevented.

Further, by forming the locking projection 16 and the packing locking projection 17 in an annular shape, they are brought into contact with the whole circumference, and the locking projection 16 and the packing locking projection 17 are formed.
Can be reliably locked. Therefore, it is possible to surely release the seal at the time of opening.

In the cap 1 of the above embodiment, the locking projection 16 and the packing locking projection 17 are formed in an annular shape.
The present invention is not limited to this, and may be formed discontinuously in the circumferential direction.

In the above embodiment, the TE
Although the cap 1 in which a number of wings 11 are provided on the inner surface of the ring portion 9 has been illustrated, the locking means in the TE ring portion 9 is not limited to the wing 11 and is described in, for example,
Japanese Patent Application Laid-Open Nos. 296666/1994, 628514 and 6-24, each of which has a tab means and an interference bead.
No. 6619, No. 6-275415, No. 6-30780
No. 4, No. 6-313837, No. 7-84315, No. 7-109850, adopting a locking means in which the locking claw on the container side and the locking protrusion on the TE ring portion side are combined. You may.

[0025]

As described above, in the synthetic resin cap of the present invention, the packing is movable in the vertical direction, and the vertical distance between the locking projection of the packing and the packing locking projection is reduced. Is set to be equal to or greater than the bridge cutting angle / 360 × the pitch of the threaded portion, so that the packing locking projection is locked to the packing after the bridge is broken in the opening process. Therefore, the sealing release in the opening process can be sufficiently delayed compared to the bridge cutting, and the tamper-evident property can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a synthetic resin cap of the present invention.

FIG. 2 is an enlarged view of a main part of the synthetic resin cap shown in FIG.

FIG. 3 is a sectional view showing an example of a conventional synthetic resin cap.

[Explanation of symbols]

1 ... cap made of synthetic resin, 2 ... top plate part, 3 ... cylinder part,
4 Cap body, 5 Packing, 6 Horizontal score, 7 Bridge, 8 Main part, 9 Tamper evidence ring part, 10 Screw part, 11 ... Wing (locking means), 12 ... Bottom plate part, 13 ... Cylindrical part, 14 ... Flange part, 15 ... Top plate part inner surface projection, 16 ... Locking convex part , 17 ...
・ Packing locking projection, A: Vertical distance, B: Screw pitch

Claims (2)

[Claims] 1. A cap body (4) having a top plate part (2) and a tube part (3) hanging down from the periphery thereof, and a packing (5) provided in the cap body. Are divided into a main part (8) above the horizontal score by a horizontal score (6) and a tamper evidence ring part (9) connected to the main part by a bridge (7), and A screw portion (10) is provided on the peripheral wall to be screwed into the male screw of the container, and the tamper evidence ring portion has
A locking means (11) is provided for locking to the container at the time of opening to prevent movement of the tamper-evidence ring portion, and a top plate inner surface projection (15) extending downward on the top plate inner surface.
A packing engaging projection (17) projecting outward is formed on the inner surface projection of the top plate, and the packing extends upward from a bottom plate (12) and a peripheral edge of the bottom plate. (13), and on the inner surface of the cylindrical portion,
A locking projection (16) is formed for locking the packing locking projection when the cap body is moved upward, and the packing is locked by the locking projection from a raised position in contact with the top plate. The vertical distance (A) between the packing locking projection and the packing locking projection at the ascending position is the bridge cutting angle / 36.
A synthetic resin cap, wherein the cap is made to have a pitch of 0 × thread part (B) or more. 2. The vertical distance between the locking projection and the packing locking projection is set to be equal to or less than bridge cutting angle / 360 × pitch of screw portion + pitch / 2. 2. The synthetic resin cap according to 1.