JPH038252B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a mold apparatus used for injection molding or embossing (compression) molding of synthetic resin container lids having pilfer-proof properties.

[Prior art]

As a container lid for a container such as a beverage bottle, Japanese Patent Application Laid-open No. 56-74445 and Japanese Patent Application No. 57-116270 and the drawings disclose synthetic resin container lids having pilfer-proof properties. ing. Such a container lid has a top wall and a cylindrical skirt wall depending from the periphery of the top wall. On the skirt wall,
Generally, a fracture line is formed that is composed of a plurality of slits extending in the circumferential direction at intervals in the circumferential direction and a plurality of bridges located between the slits, and the skirt wall is located above the fracture line. It is divided into a main part and a pilfer-proof hem part below the break line. A female thread is formed on the inner circumferential surface of the main part, and a plurality of locking flap pieces protruding radially inward are formed at intervals in the circumferential direction on the inner circumferential surface of the pilfer-proof hem. ing.

As can be easily understood from the description in JP-A-56-74445 mentioned above, such container lids have various advantages over other types of synthetic resin container lids having pilfer-proof properties. . However, there are the following problems to be solved in connection with the molding.

[Problems with conventional technology]

In a synthetic resin container lid having pilfer-proof properties, each of the above-mentioned locking flap pieces formed on the pilfer-proof inner peripheral surface of the skirt wall is designed to prevent the above-mentioned locking flap pieces from forming when the container lid is attached to the neck of the container. From the standpoint of ensuring that each of the stop flap pieces can bend elastically and easily enough to pass through the stop flange formed on the outer circumferential surface of the mouth and neck, (a) the inner periphery of the hem of the pilfer-proof The base edge connected to the surface extends downward at an acute angle with respect to the axial direction in a direction opposite to the mounting rotation direction of the container cap when the container cap is attached to the mouth and neck, and (b) It is desirable to satisfy the requirement that the base edge protrudes in the radial direction at an angle opposite to the mounting rotation direction. However, although the above-mentioned container lid is shaped by injection molding or embossing molding, a container lid having a locking flap piece that satisfies the requirements (a) and (b) above can be molded using a normal mold. If you try to separate the mold from the container lid after molding the container lid, it will be extremely difficult to separate the mold from the container lid due to the presence of the locking flap piece. As a result, the locking flap piece may be significantly damaged or deformed. In order to solve this problem, it has generally been thought that extremely complicated and expensive molds must be used.

[Technical problem of the invention]

The present invention has been made in view of the above facts, and its main technical problem is to injection mold or press mold a container lid with a locking flap piece that satisfies the requirements (a) and (b) above. This is a molding device used for molding, which is relatively simple and inexpensive, yet allows the mold and container lid to be easily separated from each other without damaging or deforming the locking flap piece after molding the container lid. It is an object of the present invention to provide a novel molding device that allows

[Means for solving the invention]

As a result of intensive research and experiments, the inventors have discovered the above
By having the mold device used for injection molding or stamp molding a container lid having a locking flap piece that meets the requirements of (a) and (b) as follows,
It has been found that the above technical problem can be achieved.

That is, according to the present invention, there is provided a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, and a female thread is formed on the inner peripheral surface of the main portion of the skirt wall,
A plurality of locking flaps are formed at intervals in the circumferential direction on the inner circumferential surface of the pilfer-proof hem located at the lower end of the skirt wall, and each of the locking flap pieces corresponds to the pilfer-proof hem. The base edge connected to the inner circumferential surface of the container extends downward at an acute angle with respect to the axial direction in a direction opposite to the direction of rotation of the container lid when the container lid is attached to the mouth and neck of the container. , and each of the flap pieces projects radially inward from the base edge in a direction opposite to the mounting rotation direction. a first half-mold assembly and a second half-mold assembly that are relatively movable in a central axis direction toward and away from each other; a mold opening/closing means for relatively moving the mold assembly in the direction of the central axis, and the first half mold assembly is configured to open and close at least a portion of the outer surface of the top wall and the outer surface of the skirt wall of the container lid. the second half-mold assembly includes a central male member defining an inner surface of the top wall of the container lid and an inner circumferential surface of the main portion of the skirt wall; an outer male member whose surface defines an inner circumferential surface of the pilfer-proof hem of the skirt wall of the container lid, the outer male member being rotatable about a central axis; When the container lid and the outer male member are moved relative to each other in the direction of the central axis in order to separate the container lid and the outer male member, the locking flap piece A mold apparatus is provided, characterized in that the presence causes the outer male mold member to rotate about the central axis.

[Action of the invention]

In the molding device of the present invention, the inner circumferential surface of the pill-proof hem of the container lid, that is, the area where the locking flap piece is formed, is defined by the rotatable outer male member, and the outer male member is rotatable. When the outer male member and the container lid are moved relative to each other in the direction of the central axis in order to separate the male member from the container lid, the outer male member is caused by the presence of the locking flap piece. and rotate it appropriately. Thus, even though the locking flap piece satisfies the requirements (a) and (b) above, the locking flap piece can be moved sufficiently smoothly to the outer male member without damaging or deforming the locking flap piece. You can make them leave.

[Preferred specific example]

First, referring to FIGS. 1 to 3, a specific example of a mold apparatus constructed in accordance with the present invention (for which reference will be made later to FIGS. 4-A to 4-E) will be explained. An example of a synthetic resin container lid itself that is molded using a synthetic resin container lid will be described below.

The illustrated container lid, designated as a whole by the number 2, includes a circular top wall 4 and a substantially cylindrical skirt wall 6 depending from the periphery of the top wall 4. The skirt wall 6 has a main part 8 , a pilfer-proof hem 10 located at the lower end, and a border region 12 located between the main part 8 and the pilfer-proof hem 10 . The outer diameter of the boundary region 12 is made smaller than the outer diameter of the main portion 8, and the outer diameter of the boundary region 12 is made smaller than that of the main portion 8.
The wall thickness of the main portion 8 is smaller than that of the main portion 8.
The inner diameter of the pilfer-proof hem 10 is made larger than the inner diameters of the main portion 8 and the boundary region 12. Further, the outer diameter gradually increases downward, and the outer diameter of the pilfer-proof hem 10 is arcuate in the axial cross-sectional view. A female thread 14 is formed on the inner peripheral surface of the main portion 8 . Further, the outer circumferential surface of the main portion 8 is formed with an uneven shape or a knurled shape 16 to prevent fingers from slipping when rotating the container lid 2 by placing a finger thereon. A plurality of locking flap pieces 18 are formed on the inner peripheral surface of the pilfer-proof hem 10 at intervals in the circumferential direction. As clearly shown in FIG. 2, each of the locking flap pieces 18
The base edge 20 connected to the inner circumferential surface of the pilfer-proof hem is connected to the mounting rotation direction of the container lid 2 (from above in FIG. (clockwise direction when viewed from above) (counterclockwise direction when viewed from above in Figure 1)
, and extends obliquely at an acute angle α with respect to the axial direction. Each of the locking flap pieces 18 projects radially inward from the base edge 20 at an angle opposite to the mounting rotation direction. The locking flap piece 18 itself has a substantially triangular shape, and its upper edge 22 extends downwardly and radially inward while being inclined at a slight angle β, and its lower edge 24 extends upwardly and at a corresponding angle β. and extends radially inwardly at an angle γ of, for example, 60 degrees. The angle β is such that the locking flap piece 18 is elastically deflected along its base edge 20 in a direction opposite to the mounting rotation direction, so that one side of the locking flap piece 18 is bent toward the pilfer-proof hem 10. Conveniently, the upper edge 22 is arranged to be substantially horizontal when in contact with the upper edge 22 .

Next, with reference to Figures 4-A to 4-E,
A specific example of a molding device configured according to the present invention, which is used for injection molding (or embossing molding) the container lid 2 as described above, will be described.

The illustrated mold assembly, designated generally by the numeral 26, includes a first mold half assembly 28 and a second mold half assembly 30. The first half mold assembly 28 is a support substrate 3
2, and the second half mold assembly 30 has a support substrate 34.
has. Support substrate 32 of first half-assembly 28
and the supporting substrate 34 of the second half-mold assembly 30 are moved toward and away from each other by an appropriate mold opening/closing means (not shown) in the central axis direction, that is, in FIGS. 4-A to 4-E. The mold opening/closing operation is performed by moving the mold in the vertical direction. In the illustrated embodiment, the support substrate 32 of the first half-mold assembly 28 is fixed in place, while the support substrate 34 of the second half-mold assembly 30 is
-E is mounted so that it can be raised and lowered in the vertical direction, and the mold can be opened and closed by moving the support substrate 34, and thus the second half mold assembly 30, up and down using a mold opening and closing means (not shown). The operation is performed.

The first half-mold assembly 28 has a support frame 35 fixed on the support substrate 32. A through hole 38 with a circular cross section is formed in the center of the support frame 35 having a flat upper surface 36. A female member 40 having a generally cylindrical shape is fixed within this through hole 38 . A large diameter portion 42 is formed at the lower end of the through hole 38, while a corresponding annular flange 44 is formed at the lower end of the female member 40, and the annular flange 44 is engaged with the large diameter portion 42. This ensures that the female member 40 is positioned at a predetermined position relative to the support frame 35. The flat upper surface of the female member 40 is substantially coplanar with the flat upper surface 36 of the support frame pair 35. Female member 4
A substantially cylindrical recess 46 is formed in the center of the upper surface of the 0. Such a recess 46 partially defines a mold cavity, as will become clear from the following description. The bottom surface 48 of the recess 46 defines the outer surface of the top wall 4 in the container lid 2 to be molded, and the side surface 50 of the recess 46 defines the outer surface of the main portion 8 of the skirt wall 6 in the container lid 2 to be molded. The support substrate 32 and the female mold member 40 are formed with an injection passage or runner 52 whose upper end opens into the bottom surface 48 of the recess 46 .

Next, the structure of the second half mold assembly 30 will be explained. The second half mold assembly 30 has a main support frame 54 fixed to the support substrate 34. The main support frame 54 in the illustrated example consists of members 56, 5 stacked sequentially from top to bottom.
8, 60 and 62. These members 5
6, 58, 60, and 62 are fastening screws 64 (fourth-A
In the figures to 4-E, one fastening screw 64 is shown.
(only one part is shown). The head of the fastening screw 64 is housed in a recess formed in the upper surface of the member 56, and the shaft portion of the fastening screw 64 passes through the members 56, 58, and 60 and is threaded into the member 62. The uppermost member 56 of the main support frame 54 has fastening screws 65 (one screw is shown in FIGS. 4-A to 4-E) at a plurality of positions spaced apart in the circumferential direction. Fastening screw 65
(only the supporting substrate 34 is shown)
Thus, the entire main support frame 54 is fixed to the support substrate 34. Fastening screw 65
The head of the fastening screw 65 is accommodated in a recess formed on the lower surface of the member 56, and the shaft portion of the fastening screw 65 passes through the member 56 and is screwed into the support substrate 34. At the center of the members 60 and 62 of the main support frame 54, respectively,
Through holes 66 and 68 are formed. and,
The through holes 66 and 68 have a substantially cylindrical central male member 70 and a substantially cylindrical outer male member 7.
2 is installed. The central male member 70 is mounted so as to be movable over a predetermined range in the direction of the central axis 74. On the other hand, the outer male member 72 cannot move in the direction of the central axis 74 but is rotatably mounted around the central axis 74. More specifically, the through hole 66 formed in the member 60
consists of a small diameter part located in the upper half and a large diameter part located in the lower half, and the large diameter part has a plurality of disc-shaped members 76 and 78 located at intervals in the circumferential direction. fastening screws 80 (4th-A to 4th-E)
In the figure, only one fastening screw 80 is shown). The head of the fastening screw 80 is accommodated in a recess formed on the upper surface of the member 60, and the shaft portion of the fastening screw 80 passes through the members 60 and 76 and is screwed into the member 78. A small diameter through hole 82 is formed in the center of the member 76, and a relatively large diameter through hole 84 is formed in the center of the member 78. The upper part of the outer male member 72 has a cylindrical outer peripheral surface, and an annular flange 86 is integrally formed at the upper end thereof. The upper outer peripheral surface of the outer male member 72 is supported on the side surface of the through hole 68 with a bearing member 88 interposed therebetween, and the annular flange 86 is connected to the upper surface of the member 62 and the member 78 via thrust bearing members 90 and 92. It is held between the lower surface of the main support frame 54 and thus cannot move in the direction of the central axis 74, but is rotatably attached to the main support frame 54 about the central axis 74. Outer male member 72
The lower outer circumferential surface of has a conical portion 94 whose outer diameter gradually decreases toward the bottom.
The tip outer circumferential surface 96 (4th-D and 4th-E)
Figure) shows a container lid 2 to be molded, as will be mentioned later.
defines the inner circumferential surface of the pilfer-proof hem 10 in the skirt wall 6 (therefore, FIGS.
It has a shape corresponding to the inner circumferential surface of the pilfer-proof hem 10 of the skirt wall 6 of the container lid 2 shown in the figure). On the other hand, the upper part of the central male member 70 has a cylindrical outer peripheral surface, and is slidably inserted into the outer male member 72 which has a cylindrical inner peripheral surface. An annular ring 98 is threaded onto the upper end of the central male member 70 . The annular ring 98 has an outer diameter smaller than the inner diameter of the through hole 84 formed in the member 78 but larger than the inner diameter of the outer male member 72. As described above, the central male member 70 is located at the uppermost position where its upper end and/or the upper end of the annular ring 98 abuts the lower surface of the member 76 (see FIG. 4-A), and at the uppermost position where the annular ring 98 is located at the outer male part. It will be clear that the member 72 is attached to the main support frame 54 so as to be movable in the direction of the central axis 74 between the lowermost position (see FIG. 4-C) where it abuts the upper surface of the member 72. Even in the uppermost position, the lower part of the central male member 70 projects downward beyond the lower end of the outer male member 72. The outer peripheral surface 100 of the lower part defines the inner peripheral surface of the main portion 8 and the boundary area 12 of the skirt wall 6 of the container lid 2 to be formed (therefore, as will be mentioned later, Container lid 2 shown in the figure
The main part 8 and the boundary area 12 in the skirt wall 6 of
(has a shape corresponding to the inner circumferential surface of). As will become clear from the following description, the outer diameter of the lower part of the central male member 70 that protrudes downward beyond the lower end of the outer male member 72 even in the uppermost position is larger than the inner diameter of the outer male member 72. is also large, and in the uppermost position, the annular shoulder existing at the upper end of the lower part of the central male member 70 abuts the lower end surface of the outer male member 72 (therefore, this also causes the central male mold member to The member 70 is prevented from rising relative to the main support frame 54 from the uppermost position).

The second mold half assembly 30 further includes a secondary support frame 102 attached to the main support frame 54 .
A large diameter through hole 104 is formed in the center of the member 58 of the main support frame 54, and the sub support frame 1
02 is composed of members 106 and 108 that are housed in the through hole 104 so as to be movable in the direction of the central axis 74. The members 106 and 108 are held together by fastening screws 110 (only one fastening screw 110 is shown in FIGS. 4-A to 4E) at a plurality of circumferentially spaced positions. is connected to. The head of the fastening screw 110 is housed in a recess formed in the upper surface of the member 106, and the shaft portion of the fastening screw 110 passes through the member 106 and is threaded into the member 108. The member 106
and 108, connecting rods 112 extending downwardly at a plurality of circumferentially spaced locations (only one connecting rod 112 is shown in FIGS. 4-A through 4-E). is provided. The large diameter head of the connecting rod 112 is the member 1.
A shaft part accommodated in a recess formed in the upper surface of 06 and extending downward from the large diameter head is connected to members 106 and 10.
8 and further extends through the main support frame 54.
through holes 114 and 116 formed in members 60 and 62 at. A fastening screw 11 is attached to the lower end of the connecting rod 112.
An additional female member 120 is secured by 8 . The head of the fastening screw 118 is connected to the additional female member 12
The shank of the fastening screw 118 passes through the additional female member 120 and is screwed into the lower end of the connecting rod 112. The lower surface 112 of the additional female member 120 is a substantially flat surface. A through hole 124 is formed in the center of the additional female member 120. A portion 126 other than the lower end of the through hole 124 has a conical shape corresponding to the conical portion 94 of the outer male member 72, and the lower end 128 is slightly larger than the outer peripheral surface of the lower end of the central male member 70. It is of large diameter and defines the outer circumferential surface of the pilfer-proof hem 10 and boundary area 12 in the skirt wall 6 of the container lid 2 to be formed, as will be mentioned later (therefore shown in FIGS. 1 to 3). pilfer-proof hem 10 and border area 1 in the skirt wall 6 of the container lid 2
2). The member 60 through which the connecting rod 112 passes
The through hole 114 formed in the connecting rod 112
The upper half of the through hole 116 formed in the member 62, which is somewhat larger than the outer diameter of the connecting rod 112, and through which the connecting rod 112 also passes,
2, there is an upwardly directed annular shoulder 130 in the through hole 116. and,
This annular shoulder 130 and the member 1 of the sub-support frame 102
Spring means 132, which may be a compression coil spring, is located on the outside of the connecting rod 112.
is interposed. This spring means 132
is the sub-support frame 102 relative to the main support frame 54.
is elastically deflected upward in the central axis direction (i.e., in a direction away from the first half-mold assembly 28) and elastically held in the uppermost position shown in FIGS. 4-A and 4-B. do. In this uppermost position, the upper surface of member 106 abuts the lower surface of member 56 and the upper surface of additional female member 120 abuts the lower surface of member 62.

In connection with the secondary support frame 102 described above, the second half-assembly 30 includes a spring means 13 that moves the secondary support frame 102 from the uppermost position relative to the main support frame 54.
First moving means 134 are provided for lowering (i.e. moving towards said first half-assembly 28) against the elastic biasing action of said first half-assembly 28. In the illustrated example, a through hole 136 is formed in the center of the member 56 in the main support frame 54, while a through hole 136 is formed in the center of the member 56 in the sub support frame 102.
A cylinder block 138 (this cylinder block 138 constituting a part of the second moving means will be further referred to later) is fixed to the center of the upper surface of the cylinder block 138 located in the through hole 136.
In addition, a through hole 140 is also formed in the center of the support substrate 34 to which the main support frame 54 is fixed. The first moving means 134 includes a plunger 142 whose lower end is inserted into the through hole 140, and an appropriate lifting/lowering mechanism such as a hydraulic cylinder mechanism for lowering the plunger 142 as required. It consists of a moving mechanism (not shown). The plunger 142, whose lower surface is brought into contact with the upper surface of the cylinder block 138, is positioned at the uppermost position shown in FIGS. 4-A and 4-B and in the uppermost position shown in FIGS. It is mounted so that it can be moved up and down between the lowest position shown in Figure E. For example, when the plunger 142 is lowered from the uppermost position to the lowermost position by supplying pressure fluid to the lifting mechanism (not shown), the sub-support frame pair 102 is moved from the main support frame. 4-D from the top position shown in FIG. 4-A and FIG. 4-B.
It is lowered against the biasing action of spring means 132 to the lowest position shown in Figures 1 and 4E. On the other hand, if the pressure fluid is allowed to freely flow out of the elevating mechanism, for example, the spring means 1
Due to the elastic eccentricity of 32, the secondary support frame 102
is raised from the lowermost position to the uppermost position with respect to the main support frame 54, and accordingly, the plunger 142 is also raised from the lowermost position to the uppermost position.

In the illustrated example, the central male member 70 is further formed with a relatively small-diameter through hole 144 in its center, into which a kickout piece 146 slides in the vertical direction. It is freely arranged. The through hole 144 formed in the central male member 70 has a conical shape in which the inner diameter gradually increases downward. A conical head 148 is formed in which the diameter gradually increases. Therefore, the kickout piece 146
further rises relative to the central male member 70 from the position where the head 148 is locked to the lower end of the through hole 144 (the position shown in Figures 4-A to 4-C). It is not possible. In such a position, the distal end surface of the kickout piece 146, or the lower surface of the head 148, cooperates with the distal end surface or lower surface of the central male member 70 to be shaped. defines the inner surface of the top wall 4 of the container lid 2. On the other hand, the kickout piece 146 is lowered relative to the central male member 70 from the above-described position relative to the central male member 70, ie, the mold defining position;
It is possible to project beyond the lower surface of the central male member 70. The kickout piece 146 extends upwardly from the head 148 at its lower end to the central male member 70.
The upper ends thereof protrude into through holes 150 and 152 formed in the central portions of members 106 and 108 of the sub-support frame 102, respectively. In the through hole 152 of the member 108, there is formed a substantially pot-shaped member 1 in which a through hole is formed in the bottom wall 154 of the member 108, through which the kickout piece 146 passes.
56 is fixed. Through hole 15 of member 108
2 has a large diameter portion at the upper end, and one member 156
There is a corresponding annular flange at the upper end of the
By locking this annular flange portion to the large diameter portion of the through hole 152, the member 146 is fixed within the through hole 152 as required. A male thread is cut into the upper end of the kickout piece 146, and a nut 158 is screwed into the male thread. A spring means 160, which may be a compression coil spring located outside the kickout piece 146, is interposed between the nut 158 and the bottom wall 154 of the member 156. The spring means 160 elastically biases the kickout piece 146 upwardly in the direction of the central axis (ie, in a direction away from the first mold half assembly 28) with respect to the secondary support frame 102. In conjunction with such a kick-out piece 146, the second half-assembly 30 includes a second half-assembly 30 for lowering the kick-out piece 146 against the elastic biasing action of spring means 160.
A moving means 162 is provided. This moving means 162 is a member 10 in the sub-support frame 102.
6 includes the above-mentioned cylinder block 138 located at the center of the upper surface of the cylinder block 6. This cylinder block 138
These include a pot-shaped member 164 fixed to the center of the upper surface of the member 106 by appropriate means (not shown), and a disc 166 fixed to the upper end of the member 164 and closing the upper end of the member 164. It is composed of. A sliding body 168 is accommodated in such a cylinder block 138. This sliding body 168 has a head having an outer circumferential surface that is in close contact with the inner circumferential surface of the member 164, and a shaft portion extending downward from the head, the shaft portion being formed on the bottom wall of the member 164. The nut 1 projects downward through the through hole and is screwed into the upper end of the kickout piece 146.
It is in contact with the upper surface of 58. A passage 176 is formed in the members 164 and 166 that make up the cylinder block 138. One end of this passage 176 is open to the lower surface of member 166, and the other end is formed in member 58 from a radially extending passage 178 formed in member 196 and a radially outer end of this passage 178. Radial opening 180
A flexible conduit 182 extending therethrough selectively connects to a source of pressurized fluid (not shown), such as compressed air or pressurized oil. Supplying pressurized fluid to cylinder block 138 from a source of pressurized fluid (not shown) through flexible conduit 182 and passageways 178 and 176 causes slide 168 to be lowered, thereby acting on the elastic biasing action of spring means 160. The kickout piece 146 is lowered against the
Figure E). On the other hand, when the flexible conduit 182 is placed in communication with the atmosphere or with a pressure fluid sump (not shown) so that pressure fluid can flow freely from within the cylinder block 138, the elastic biasing action of the spring means 160 As a result, the kickout piece 146 is raised and the sliding body 168 is also raised, so that the upper end of the sliding body 168 comes into contact with the lower surface of the member 166 of the cylinder block 138 (Fig. 4-A, Fig. 4-4).
Figure B, Figure 4-C and Figure 4-D).

Next, the effects of the mold device 26 as described above will be explained.

When molding the container lid 2, the molding device 26
is positioned as shown in FIG. 4-A. That is, the support substrate 34 of the second half-mold assembly 30 is lowered by the mold opening/closing means (not shown), and the lower surface 130 of the additional female mold member 120 in the second half-mold assembly 30 is brought down to the first position. The upper surface 36 of the support frame 35 in the half mold assembly 28 is brought into contact with the upper surface 36 of the support frame 35. In the state illustrated in FIG. 4-A, the first moving means 134 and the second moving means 162 in the second half-mold assembly 30 are not activated, and therefore the secondary support frame 102 is The kick-out piece 146 is at the uppermost position with respect to the main support frame 54, and the kick-out piece 146 is at the uppermost position with respect to the sub-support frame 102, and is at the mold restriction position with respect to the central male member 70. In the state shown in FIG. 4-A, the lower part of the central male member 70 in the second half-mold assembly 30 is in contact with the center of the upper surface of the female member 40 in the first half-mold assembly 28. The female member 40 in the first mold half assembly 28, the kickout piece 146 in the second mold half assembly 30, the central male mold member 70, the outer In cooperation with the male part 72 and the additional female part 120 a molded cavity for the container lid 2 is defined. And the 4th-A
Support substrate 32 and female mold member 40 in first mold half assembly 28 are injected from suitable injection means (not shown) while maintained in the condition shown in the figures.
Through an injection passage or runner 52 formed in the container, a suitable synthetic resin material (for example polyethylene or polypropylene) in a softened molten state is injected into the molding cavity, and the container lid 2 is thus injection molded. Referring to FIG. 3 together with FIG. 4-A, as described above, the bottom surface 48 and inner peripheral surface 50 of the recess 46 formed in the female mold member 40 in the first half mold assembly 28 are The outer surface of the top wall 4 of the container lid 2 and the outer peripheral surface of the main portion 8 of the skirt wall 6 are defined. The lower end 128 of the through hole 124 formed in the additional female mold member 120 of the second mold half assembly 30 is connected to the pilfer-proof skirt 10 and the border area 12 in the skirt wall 6 of the container lid 2.
Define the outer peripheral surface of The lower surface of the head 148 of the kick-out piece 146 in the second half-mold assembly 30 and the lower surface of the central male member 70 cooperate to define the inner surface of the top wall 4 of the container lid 2. Lower outer peripheral surface 1 of the central male member 70 in the second half-mold assembly 30
00 is the main part 8 in the skirt wall 6 of the container lid 2
and defines the inner circumferential surface of the boundary region 12. and,
Outer male member 72 in second mold half assembly 30
The lower end, that is, the outer circumferential surface 96 of the tip end is the pilfer-proof hem 10 of the skirt wall 6 of the container lid 2
Define the inner peripheral surface of. Therefore, the outer male member 72
A plurality of locking flap pieces 18 (FIGS. 1 to 3) are provided on the outer circumferential surface of the distal end of the flap at intervals in the circumferential direction.
A notch is formed to define the

The container lid 2 injection-molded as described above is sufficiently cooled (in order to accelerate cooling, appropriate circulation paths (not shown) are formed in the female mold member 40, central male mold member 70, etc.). , an appropriate cooling medium such as water can be circulated in such a circulation path)
Then, the support substrate 34 of the second half-mold assembly 30 is raised by a mold opening/closing means (not shown),
Thus, the second mold half assembly 30 is spaced upwardly relative to the first mold half assembly 28, as shown in FIG. 4-B. At this time, the molded container lid 2
is raised along with the second mold half assembly 30 and removed from the recess 46 of the female mold member 40 in the first mold half assembly 28.

The first moving means 134 in the second mold half assembly 30 is then actuated to move the secondary support frame 102 relative to the primary support frame 54 through the position illustrated in FIG. 4-C. - It is lowered to the position shown in Figure D. While the sub-support frame 102 is lowered to the position shown in No. 4-D, the additional female member 120 and the kick-out piece 146 are lowered along with the sub-support frame 102. The molded container lid 2 is also lowered. And Figure 4-B and Figure 4
- Concomitant with the lowering of the molded container lid 2, the central male member 70 also lowers its upper end and/or the annular ring fixed thereto, as will be easily understood by comparative reference to Figure C. From the uppermost position where the annular ring 98 abuts the lower surface of the member 76, the annular ring 98 is lowered down to the lowermost position where the annular ring 98 abuts the upper surface of the outer male member 72. On the other hand, since the outer male member 72 is attached to the main support frame 54 so as not to be able to move up and down in the direction of the central axis 74 as described above, the outer male member 72 moves downward along with the molded container lid 2. and is maintained in the position shown in Figures 4-B and 4-C. Therefore, the outer male member 72 is raised relative to the central male member 70 and the molded container lid 2, and thus the outer male member 72
The outer circumferential surface 96 of the tip end is separated from the inner circumferential surface of the pilfer-proof hem 10 of the molded container lid 2. Thus, when the outer circumferential surface 96 of the tip end of the outer male member 72 separates from the inner circumferential surface of the pilfer-proof hem 10 of the molded container lid 2,
A plurality of locking flap pieces 18 formed on the inner peripheral surface of the pilfer-proof hem 10 are attached to the outer male member 7.
It must be separated from a plurality of corresponding notches formed in the outer circumferential surface 96 of the distal end portion of No. 2. However, as described above, in the plurality of locking flap pieces 18 (and the plurality of corresponding notches), the base edges 20 thereof are attached to the container lid 2 when the container lid 2 is attached to the mouth and neck of the container. rotational direction, i.e. the fourth
4-B and 4-C are inclined at an acute angle α (FIG. 2) with respect to the central axis 74 in the opposite direction to the counterclockwise direction when viewed from above. - A plurality of locking flap pieces 18 (and a plurality of corresponding notches) extend upward in FIG. Extending radially inward. Because of this, simply raising the outer male member 72 relative to the molded container lid 2 will not allow the plurality of locking flap pieces 18 and the corresponding plurality of notches to be formed. It is impossible or extremely difficult to remove them, and if an attempt is made to remove the two forcibly, the plurality of locking flap pieces 18 will be significantly damaged or deformed. However, in the illustrated mold assembly 26 constructed in accordance with the present invention, the outer male mold member 7 is
2 is rotatably mounted around a central axis 74. Therefore, when the outer male member 72 is raised relative to the molded container lid 2, a plurality of locking flap pieces are used. 18 (and the corresponding plurality of notches), the outer male member 72 is rotated counterclockwise when viewed from above in FIGS. 4-B and 4-C. . In this way, the tip outer circumferential surface 96 of the outer male member 72 can be fixed without damaging or deforming the plurality of locking flap pieces 18 in the molded container lid 2.
is detached from the inner circumferential surface of the pilfer-proof hem 10 of the container lid 2, which is extremely smoothly formed.

Next, the sub-support frame 1 is attached to the main support frame 54.
02 from the position shown in Figure 4-C to Figure 4-D.
During the lowering to the position shown in the figure, the additional female member 120 and the kickout piece 146 are lowered along with the secondary support frame 102, and the additional female member 120 and the kickout piece 146 are Along with the lowering, the molded container lid 2 is also lowered, but the central male member 70 is lowered because the annular ring 98 fixed to its upper end comes into contact with the upper surface of the outer male member 72. It is blocked and maintained in the position shown in Figures 4-C and 4-D.

The central male member 70 is therefore raised relative to the molded container lid 2 and thus the fourth-
As shown in FIG.
The main portion 8 and the inner circumferential surface of the boundary region 12 are separated from each other. Lower outer peripheral surface 100 of central male member 70
When passing through the inner circumferential surface of the pilfer-proof hem 10 of the container lid 2, each of the plurality of locking flap pieces 18 is elastically bent radially outward, thus central male member 70 without damaging or damaging the locking flap piece 18.
The lower inner circumferential surface 100 of the pilfer-proof hem 1
It passes through the inner peripheral surface of 0. When the lower inner circumferential surface 100 of the central male member 70 finishes passing the inner circumferential surface of the pilfer-proof hem 10, the plurality of locking flap pieces 1
8 elastically returns to its original state.

After the secondary support frame 102 has been lowered relative to the main support frame 54 to the position shown in FIG. 4-D, the second moving means 162 in the second half mold assembly 30 is actuated. , kickout piece 14
6 is lowered from the position shown in FIG. 4-D to the position shown in FIG. 4-E. Such lowering of the kick-out piece 146 causes the formed container lid 2 to be lowered further, thereby removing the container lid 2 from the additional female part 120, and more particularly its pilfer-proof skirt 10 and border. The outer peripheral surface of region 12 is removed. Thereafter, the container lid 2 is free to fall and disengage from the lockout piece 146, and is received by a suitable ejection means (not shown) and removed from the mold assembly 26. Next, the mold device 26 is again brought into the state shown in FIG. 4-A, and injection molding of the next container lid 2 is started.

Although a specific example of a molding device configured according to the present invention has been described in detail above, the molding device of the present invention is not limited to such a specific example, and there may be cases where it deviates from the scope of the present invention. It goes without saying that various modifications and modifications can be made without having to do so.

For example, although the above-mentioned specific example is used for injection molding the container lid 2, the mold apparatus of the present invention is an embossing (compression) molding mold apparatus for embossing (compression) molding the container lid 2. It is also applicable to

Further, in the container lid 2 molded according to the above-described specific example, no break line is formed in the boundary area 12 of the skirt wall 6, and the break line is formed after injection molding, for example, when the container lid 2 is attached to the container. Although it is intended to be formed during application to the mouth and neck, if desired, the break line may also be formed at the same time during injection or embossing (compression) molding, as in the conventional case. Modifications can also be made to the mold apparatus.

Furthermore, in the container lid 2 molded according to the embodiment described above, the inner peripheral edge of the top wall 4 is substantially flat, but if desired, for example, the tip or lower surface of the central male member 70 may An annular groove of an appropriate shape is carved on the peripheral edge, thereby forming a known sealing annular protrusion on the inner surface of the top wall 4, which is brought into close contact with the top surface of the mouth and neck of the container. You can also do as you wish. Alternatively, after the container lid 2 has been molded, a separate additional step can be carried out to provide a separately molded sealing liner, which is known per se, on the inner surface of the top wall 4. can.

〔Effect of the invention〕

As described in detail above, according to the synthetic resin container lid molding apparatus of the present invention, the pill holder located at the lower end of the skirt wall can be used without making the mold apparatus itself unnecessarily complicated and effective. To form a container lid made of synthetic resin in a form in which a plurality of locking flap pieces of a specific shape are present on the inner circumferential surface of a proof hem, sufficiently easily and smoothly without accompanying breakage or deformation of the locking flap pieces. be able to.

[Brief explanation of the drawing]

FIG. 1 is a side view, partially in cross section, of an example of a container lid molded using a mold apparatus configured according to the present invention. 2 is a partial perspective view showing a part of the container lid of FIG. 1; FIG. FIG. 3 is a partial cross-sectional view of a portion of the container lid of FIG. 1, together with a portion of the mold apparatus used to mold it; 4th-A
Figures 4-B, 4-C, 4-D and 4-E show portions of a specific example of a mold apparatus constructed in accordance with the present invention in various states. Cross-sectional view. 2... Container lid, 4... Top wall, 6... Skirt wall, 8... Main part of skirt wall, 10... Pilf-proof hem of skirt wall, 12... Boundary area of skirt wall, 14... ... female thread, 18 ... locking flap piece, 26 ... mold device, 28 ... first half mold assembly, 30 ... second half mold assembly, 40 ...
...female member, 54...main support frame of second half-mold assembly, 70...central male member, 72...outer male member, 102...secondary support of second half-mold assembly Frame body, 120...Additional female member, 134...Second
146 . . . kickout piece; 162 . . . third moving means of the second half mold assembly.

Claims (1)

[Scope of Claims] 1. It comprises a top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, a female thread is formed on the inner peripheral surface of the main part of the skirt wall, and a female thread is formed at the lower end of the skirt wall. A plurality of locking flap pieces are formed at intervals in the circumferential direction on the inner circumferential surface of the pilf-proof hem, and each of the locking flap pieces is connected to the inner circumferential surface of the pilf-proof hem. The base edge extends downward at an acute angle with respect to the axial direction in a direction opposite to the direction of rotation of the container lid when the container lid is attached to the mouth and neck of the container, and extends downwardly at an acute angle with respect to the axial direction. Each of them is a molding device for molding a synthetic resin container lid having a configuration that projects radially inward from the base edge in a direction opposite to the mounting rotation direction; a first half-mold assembly and a second half-mold assembly that are relatively movable in directions of spaced apart center axes; a mold opening/closing means for relative movement in the axial direction; The second half mold assembly includes a central male member defining an inner surface of the top wall of the container lid and an inner peripheral surface of the main portion of the skirt wall; an outer male mold member defining an inner circumferential surface of the pilfer-proof hem of the skirt wall, the outer male mold member being rotatable about a central axis, and the outer male mold member being rotatable about a central axis; When the container lid and the outer male mold member are moved relative to each other in the direction of the central axis in order to separate them from each other, due to the presence of the locking flap piece, A mold apparatus characterized in that an outer male mold member is rotated about the central axis. 2. The central male mold member and the outer male mold member in the second half-mold assembly are relatively movable in the direction of the central axis, and the central male mold member and the outer male mold member are separated after molding. are moved relative to each other in the central axis direction, and at this time, the container lid is moved together with the central male member relative to the outer male member, and the container lid and the outer The mold device according to claim 1, wherein the male mold member is detachable. 3. The mold of claim 2, wherein the second mold half assembly also includes an additional female member defining an outer surface of the pilfer-proof hem of the skirt wall of the container lid. Device. 4. The central male mold member in the second half-mold assembly is provided with a kick-out piece that passes through the center in the direction of the central axis, and the tip surface of the kick-out piece is connected to the central male mold member. projecting beyond the distal end surface of the central male member in a direction approaching the first mold half assembly from a mold defining position that cooperates with the distal end surface of the member to define the inner surface of the top wall of the container lid; The mold apparatus according to claim 3, wherein the mold apparatus is capable of: 5. The second half-mold assembly is attached to the main support frame so as to be movable over a predetermined range in the direction of the central axis, and is attached to the first half-mold by spring means. a secondary support frame resiliently biased away from the assembly; the secondary support frame being biased toward the first half-assembly against the resilient biasing action of the spring means; a first moving means for moving the outer male member, the outer male member cannot move in the direction of the central axis with respect to the main support frame, but is rotatable about the central axis; attached to the support frame, the additional female member is fixed to the main and sub-support frame, and the kick-out piece is movably attached to the sub-support frame over a predetermined range in the direction of the central axis; mounted and resiliently biased away from the first mold half assembly by spring means, the central male member being disposed within the main support frame over a predetermined extent along the central axis; The central male member and the kick-out piece are mounted movably relative to the body, and the central male member and the kick-out piece move from the mold defining position to the third position relative to the central male member. the second half-mold assembly is assembled such that it cannot move away from the first half-mold assembly; and further, the second half-mold assembly resists the resilient biasing action of the spring means. 5. The mold apparatus according to claim 4, further comprising second moving means for moving the first mold half assembly in a direction approaching the first mold half assembly.