JP7684063B2 - Plastic container lid - Google Patents

Description

The present invention relates to a synthetic resin container lid including a main body to be attached to the mouth and neck of a container and a top lid connected to the main body via hinge means.
Regarding.

Conventionally, container lids equipped with slit valves as disclosed in the following Patent Document 1 have been well known as container lids capable of discharging liquid contents such as liquid seasonings little by little from a container containing the liquid contents. The following Patent Document 1 discloses a synthetic resin container lid including a main body having a circular closing wall and a cylindrical hanging wall hanging from the outer periphery of the closing wall, and a top lid having a circular top wall and a cylindrical skirt wall hanging from the outer periphery of the top wall. The top lid and the main body are connected via a hinge means, and the top lid can freely rotate between a closed position in which the closing wall of the main body is covered and an open position in which the closing wall is exposed. The closing wall is formed with a cylindrical protruding wall with a circular cross section protruding upward, and a cylindrical wall hanging downward is formed on the underside of the top lid, and when the top lid is in the closed position, the inner peripheral surface of the cylindrical wall faces and approaches or abuts against the outer peripheral surface of the protruding wall. The slit valve is attached to the inside of the protruding wall.

Patent No. 4145523

In the container lid disclosed in Patent Document 1, the main body and the top lid are connected via a hinge means, which causes the following problems to be solved. That is, when the container lid is attached to the mouth and neck of a container containing contents and the container lid falls together with the container, and the top lid of the container lid, more specifically, the side of the top wall of the top lid opposite the hinge means, hits the ground, the impact of the collision acts to shift the top lid laterally relative to the main body, which may break the hinge means connecting the two. In a container lid in which the main body and the top lid are connected via a hinge means, a flange portion that protrudes radially outward is usually formed on the outer peripheral surface of the top wall on the radially opposite side of the hinge means, so when the container lid falls together with the container, the flange portion hits the ground and the top lid is often impacted by the flange portion. In particular, when the container lid is made of a relatively hard material such as polypropylene, it has poor adaptability to deformation and is easily damaged.

The present invention was made in consideration of the above facts, and its main technical objective is to provide a new and improved synthetic resin container lid that can prevent as much as possible the hinge means from breaking when an impact is applied to the top lid from the side opposite the hinge means.

After extensive research, the inventors discovered that the above-mentioned main technical objective could be achieved by providing a reinforcing section that locally increases the outer diameter of the cylindrical wall on the diametrically opposite side of the outer circumferential surface of the cylindrical wall from the hinge means.

That is, according to the present invention, a synthetic resin container lid that achieves the above-mentioned main technical object includes a main body having a circular closing wall and a cylindrical hanging wall depending from the outer periphery of the closing wall, and a top lid having a circular top wall and a cylindrical skirt wall depending from the outer periphery of the top wall, the top lid and the main body being connected via hinge means, and the top lid being freely rotatable between a closed position in which the closing wall of the main body is covered and an open position in which the closing wall is exposed,
A synthetic resin container lid, in which the closing wall is formed with a cylindrical protruding wall having a circular cross section protruding upward, and a cylindrical wall is formed on the underside of the top lid so as to hang down downward, and when the top lid is in the closed position, the inner peripheral surface of the cylindrical wall faces and comes close to or abuts against the outer peripheral surface of the protruding wall,
A reinforcing portion that locally increases the outer diameter of the cylindrical wall is provided on the portion of the outer peripheral surface of the cylindrical wall diametrically opposite the hinge means , the reinforcing portion is provided continuously in the circumferential direction on the outer peripheral surface of the cylindrical wall, and the radial thickness of the cylindrical wall is thickest at an angular position diametrically opposite the hinge means and gradually decreases from that angular position toward both sides in the circumferential direction .

The top wall may have a flange formed on an outer circumferential surface thereof on the diametrically opposite side of the hinge means, the flange being made of polypropylene. The protruding wall is preferably in the shape of a truncated cone. A slit valve may be conveniently attached to the inside of the protruding wall .

In the synthetic resin container lid constructed according to the present invention, a reinforcing portion is provided on the outer peripheral surface of the cylindrical wall on the diametrically opposite side of the hinge means, which locally increases the outer diameter of the cylindrical wall. This increases the rigidity of the cylindrical wall in the portion where the reinforcing portion is provided. Therefore, even if an impact is applied to the top lid from the opposite side of the hinge means, the cylindrical wall does not deform, and its inner peripheral surface abuts against the outer peripheral surface of the protruding wall, restricting the top lid from moving laterally relative to the main body, and preventing the hinge means from breaking as much as possible.

1 is a plan view of a synthetic resin container lid constructed according to the present invention with the top lid in an open position; 2 is a cross-sectional view of the synthetic resin container lid shown in FIG. 1 along line AA. 2 is a side view of the synthetic resin container lid shown in FIG. 1 when the top cover is in a closed position. 2 is a cross-sectional view taken along line AA of FIG . 1 when the upper lid of the synthetic resin container lid is in a closed position.

The present invention will now be described in more detail with reference to the attached drawings showing a preferred embodiment of a synthetic resin container lid constructed in accordance with the present invention.

Referring to Figures 1 and 2, the container lid, generally designated by the numeral 2, includes a main body 4 and a top lid 6, which are connected via a hinge means 8. In the illustrated embodiment, the hinge means 8 is composed of a one-side hinge portion 8a and an other-side hinge portion 8b that are spaced apart in the circumferential direction. The container lid 2 is integrally molded by injection molding an appropriate synthetic resin such as polypropylene in the state shown in Figures 1 and 2 (this state is when the top lid 6 is in an open position relative to the main body 4, which will be described later).

Continuing the explanation with reference to Figures 1 and 2, the main body 4 has a circular blocking wall 10 and a cylindrical hanging wall 12 that hangs down from the outer periphery of the blocking wall 10. A cylindrical protruding wall 14 with a circular cross section that protrudes upward is formed in the central part of the blocking wall 10, and a circular discharge port 16 is provided on the upper surface of the protruding wall 14. In the illustrated embodiment, the protruding wall 14 is in the shape of a truncated cone, and its upper end surface 18 is in the shape of a flat ring. A cylindrical hanging piece 20 that hangs down toward the inside in the radial direction is connected to the inner periphery of the upper end surface 18. A retaining protrusion 22 that protrudes toward the inside in the radial direction is formed continuously in the circumferential direction on the inner periphery of the upper end of the protruding wall 14. In the illustrated embodiment, a slit valve 24 is attached to the inside of the protruding wall 14. The slit valve 24 is composed of a valve body 26 molded from a relatively soft synthetic resin and blocking the discharge port 16 below, and an annular valve holding portion 28 made of synthetic resin that supports the valve body 26. The valve holding portion 28 is held by the holding ridge 22 on the inside of the protruding wall 14, and the valve body 26 is sandwiched between the valve holding portion 28 and the protruding wall 14. The valve body 26 is circular in plan view, and a cross-shaped slit 30 is formed in the center (see FIG. 1). When the internal pressure of the container to which the container lid 2 is attached increases, the valve body 26 expands upward in a dome shape, opening the slit 30 and allowing the contents to be discharged. Since the configuration of such a slit valve is well known, a detailed description of the slit valve is omitted in this specification. If desired, instead of the slit valve, a check valve such as that disclosed in JP 2019-182531 A, which was filed and published by the applicant of the present application prior to the present application, may be attached to the inside of the protruding wall 14. Note that attaching a valve to the inside of the protruding wall 14 is not necessarily required depending on the application.

A cylindrical locking wall 32 is formed on the outer peripheral edge of the upper surface of the blocking wall 10, protruding radially outward and upward, and a locking protrusion 34 is formed on the outer peripheral surface of the upper end of the locking wall 32, which is continuous in the circumferential direction. A cylindrical seal wall 36 is formed in the radial middle of the lower surface of the blocking wall 10, which hangs downward. A cylindrical mounting wall 38 is provided on the outer peripheral edge of the lower surface of the blocking wall 10, which hangs downward, and a female thread 40 is formed on the inner peripheral surface of the mounting wall 38. Two columnar extension pieces 42 are also provided on the outer peripheral surface of the mounting wall 38, which extend linearly from the lower surface of the blocking wall 10 downward beyond the lower end of the mounting wall 38. Two extension pieces 42 are provided on each side in the diametric direction. One side end of the hinge means 8 is connected to the upper end of the outer peripheral surface of the hanging wall 12, and a generally rectangular notch 44 is provided in a small circumferential region between the one-side hinge portion 8a and the other-side hinge portion 8b at the upper end of the outer peripheral surface of the hanging wall 12. An arc-shaped recess 46 with a locally reduced outer diameter is provided at the upper end of the outer peripheral surface of the hanging wall 12 on the side opposite the hinge means 8.

The top cover 6 has a circular top wall 48 and a cylindrical skirt wall 50 that hangs down from the outer periphery of the top wall 48, and can freely rotate between a closed position (as shown in Figs. 3 and 4) that covers the blocking wall 10 of the main body 4 and an open position (as shown in Figs. 1 and 2) that exposes the blocking wall 10. The up and down direction of the top cover 6 in this specification is based on the time when the top cover 6 is in the closed position. The other end of the hinge means 8 is connected to the lower end of the outer periphery of the skirt wall 50, and an L-shaped notch 52 is provided in a small circumferential region between the one-side hinge portion 8a and the other-side hinge portion 8b of the top cover 6 from the outer periphery of the top wall 48 to the entire skirt wall 50 (see Fig. 2). The radially outer end surface of the top wall 48, which defines the radially inner end of the notch 52, and the upper end surface of the hanging wall 12, which defines the lower end of the notch 44, are connected by an L-shaped connecting piece 54. As can be understood by comparing Figures 2 and 4, the connecting piece 54 is aligned with the notch 44 and the notch 52 when the top cover 6 is in the closed position.

A downwardly protruding rib 56 is formed on the lower surface of the top wall 48 on the side of the hinge means 8, and as shown in FIG. 4, the radially outer surface of the rib 56 faces and comes close to or abuts against the inner circumferential surface of the protruding wall 14 on the side where the hinge means 8 is present when the top cover 6 is in the closed position. In the illustrated embodiment, a cylindrical pin 58 protruding downward is formed in the center of the lower surface of the top wall 48. The pin 58 enters the inside of the protruding wall 14 when the top cover 6 is rotated from the open position to the closed position. At this time, although a detailed explanation is omitted, the pin 58 presses downward on the upper surface of the valve body 26 that bulges upward when the contents are discharged, promoting the return of the valve body 26 that bulges upward to its original state, i.e., the state shown in FIG. 4. Then, when the top cover 6 is in the closed position, the pin 58 is located close to the upper surface of the valve body 26. Although detailed description is omitted, the pin 58 promotes the valve body 26, which bulges upward when the contents are discharged, to return to its original state, i.e., the state shown in FIG. 4. The rib 56 protrudes downward from the lower surface of the top wall 48 and is connected to the outer circumferential surface of the pin 58. As shown in FIG. 1, the rib 56 is connected to the outer circumferential surface of the pin 58 on the side where the hinge means 8 is present, and is located on a diameter passing through the circumferential center of the hinge means 8, and one is provided on each side of the position in the circumferential direction at intervals. Therefore, in the illustrated embodiment, three ribs 56 are provided at intervals in the circumferential direction. If desired, the rib 56 located on the diameter passing through the circumferential center of the hinge means 8 may be omitted, or the rib 56 may be left and the other two ribs 56 located on both sides of the rib 56 in the circumferential direction may be omitted. As shown in Figures 2 and 4, the rib 56 is plate-shaped, and the radial length of its base end 56a is longer than the radial length of its tip end 56b. The base end 56a is linearly inclined downward from the lower surface of the top wall 48 toward the inside in the radial direction, and the tip end 56b hangs down substantially vertically from the lower end of the base end 56a and then extends substantially horizontally to be connected to the outer circumferential surface of the pin 58. As shown in Figure 4, in the illustrated embodiment, when the top cover 6 is in the closed position, the radial outer surface of the tip end 56b of the rib 56 is close to or in contact with the inner circumferential surface of the protruding wall 14, and the lower surface of the base end 56a of the rib 56 is close to or in contact with the upper surface of the protruding wall 14.

A cylindrical wall 60 is also formed on the lower surface of the top wall 48, hanging downward. The cylindrical wall 60 is formed radially outward of the rib 56 and concentric with the pin 58, and the lower end of the cylindrical wall 60 is located below the lower end of the rib 56 and above the lower end of the pin 58 when viewed in the vertical direction. As shown in Fig. 4, when the top cover 6 is in the closed position, the lower end of the inner peripheral surface of the cylindrical wall 60 abuts against the upper part of the outer peripheral surface of the protruding wall 14 over its entire circumferential direction, preventing leakage of the contents described below from the inside of the protruding wall 14. It is important that a reinforcing portion 62 is provided on the outer peripheral surface of the cylindrical wall 60 on the diametrically opposite side of the hinge means 8, by locally increasing the outer diameter of the cylindrical wall 60. As can be understood by referring to FIG. 1 together with FIG. 2, the reinforcing portion 62 is provided continuously in the circumferential direction on the outer circumferential surface of the cylindrical wall 60, and the radial thickness of the cylindrical wall 60 is thickest at an angular position diametrically opposite to the hinge means 8 and gradually decreases from this angular position toward both sides in the circumferential direction .

A flange 64 protruding radially outward is formed on the outer peripheral surface of the top wall 48 on the diametrically opposite side of the hinge means 8. The flange 64 is provided continuously in the circumferential direction on the outer peripheral surface of the top wall 48, and the amount of protrusion from the outer peripheral surface of the top wall 48 is greatest at the angular position diametrically opposite the hinge means 8, and gradually decreases from this angular position toward both sides in the circumferential direction. Two locking protrusions 66a and 66b extending in the circumferential direction are provided at the lower end of the inner peripheral surface of the skirt wall 50 at intervals in the circumferential direction. The locking protrusion 66a has a circumferential length longer than the locking protrusion 66b, and the locking protrusion 66a is provided on the flange 64 side, and the locking protrusion 66b is provided on the hinge means 8 side. The locking protrusions 66a and 66b elastically engage with the locking protrusions 34 of the main body 4 when the top cover 6 is in the closed position. At a required location on the outer periphery of the skirt wall 50, there is also a bulge 68 whose outer diameter gradually increases toward the flange 64 provided on the outer periphery of the top wall 48 and smoothly connects to the underside of the flange 64.

In FIG. 4, the container lid 2 constructed according to the present invention and the mouth and neck of the container to which the container lid 2 is applied are shown by two-dot chain lines. The container mouth and neck 70, which can be formed from a suitable synthetic resin, is cylindrical with an open top, and a male thread 72 is formed on the upper end of its outer circumferential surface. In the illustrated embodiment, a slit valve 24 is attached to the container lid 2, and since it is necessary to increase the internal pressure of the container by deforming the outer shape of the container in order to discharge the contents, the container is molded from a relatively soft synthetic resin, but if no valve is attached to the container lid 2, the container may be made of a hard synthetic resin or glass.

When the container lid 2 is attached to the mouth and neck portion 70 to seal the mouth and neck portion 70 after the contents are placed in the container, the container lid 2 is fitted onto the mouth and neck portion 70 and the container lid 2 is rotated clockwise as viewed from above. In this way, the container lid 2 gradually descends relative to the mouth and neck portion 70 due to the screwing of the female thread 40 of the container lid 2 with the male thread 72 of the mouth and neck portion 70, and the seal wall 36 enters the inside of the mouth and neck portion 70 and the outer peripheral surface is brought into close contact with the inner peripheral surface of the mouth and neck portion 70, thereby sealing the mouth and neck portion 70. The screwing is stopped when the extension piece 42 abuts against a stopper (not shown) provided on the mouth and neck portion 70. In this way, the container lid 2 is attached to the mouth and neck portion 70.

In the synthetic resin container lid constructed according to the present invention, a reinforcing portion 62 that locally increases the outer diameter of the cylindrical wall 60 is provided on the outer peripheral surface of the cylindrical wall 60 on the diametrically opposite side of the hinge means 8, and the rigidity of the cylindrical wall 60 at the portion where the reinforcing portion 62 is provided is increased. Therefore, even if an impact is applied to the top lid 6 from the opposite side of the hinge means 8, the cylindrical wall 60 does not deform, and its inner peripheral surface abuts against the outer peripheral surface of the protruding wall 14, restricting the top lid 6 from moving laterally relative to the main body 4, and preventing the hinge means 8 from breaking as much as possible.

<Example>
A polypropylene container lid having a nominal diameter of 30 mm and the configuration shown in Figures 1 to 4 was injection molded. A slit valve as shown in Figure 2 was also attached to the inside of the protruding wall 14 of this container lid. The radial thickness of the cylindrical wall 60 at the angular position diametrically opposite to the hinge means 8 was 1.4 mm, which was the maximum, and the radial thickness at the angular position diametrically opposite to the above angular position, i.e., on the side where the hinge means 8 was provided, was 0.75 mm, which was the minimum.

Ten polyethylene terephthalate containers with necks as shown by the two-dot chain line in Figure 4 were filled with water, and then the above-mentioned container lids were attached to the necks to seal them. A drop impact test was carried out on the ten containers filled with water and fitted with the container lids in an environment of 5°C. In this drop impact test, the containers were tilted slightly from an upright position and dropped from a required height, so that first the bottom of the container hit a steel plate floor, and then the top lid of the container hit the side opposite the hinge means against the floor. The hinge means was then inspected for damage. The results are shown in Table 1 below.

Comparative Example
A drop impact test was carried out in the same manner as in the example, except that the radial thickness of the cylindrical wall 60 was 0.75 mm over the entire circumferential direction. The results are shown in Table 1 below.

As can be seen by referring to Table 1 above, by increasing the radial thickness of the cylindrical wall 60 at the angular position diametrically opposite the hinge means 8, it has been confirmed that the drop impact resistance characteristics of the hinge means 8 are improved when an impact is applied to the top cover 6 from the opposite side of the hinge means 8.

2: Container lid 4: Main body 6: Top lid 8: Hinge means 10: Closing wall 12: Hanging wall 14: Protruding wall 48: Top wall 50: Skirt wall 60: Cylindrical wall 62: Reinforcing portion

Claims (5)

a main body having a circular closing wall and a cylindrically-shaped hanging wall depending from an outer periphery of the closing wall, and a top cover having a circular top wall and a cylindrically-shaped skirt wall depending from an outer periphery of the top wall, the top cover and the main body being connected via hinge means, and the top cover being freely rotatable between a closed position covering the closing wall of the main body and an open position exposing the closing wall,
A synthetic resin container lid, in which the closing wall is formed with a cylindrical protruding wall having a circular cross section protruding upward, and a cylindrical wall is formed on the underside of the top lid so as to hang down downward, and when the top lid is in the closed position, the inner peripheral surface of the cylindrical wall faces and comes close to or abuts against the outer peripheral surface of the protruding wall,
A reinforcing portion is provided on the outer peripheral surface of the cylindrical wall diametrically opposite to the hinge means, the reinforcing portion being provided continuously in the circumferential direction on the outer peripheral surface of the cylindrical wall, and the radial thickness of the cylindrical wall is thickest at an angular position diametrically opposite to the hinge means and gradually decreases from that angular position toward both sides in the circumferential direction. The synthetic resin container lid according to claim 1, wherein a flange protruding radially outward is formed on the outer peripheral surface of the top wall on the diametrically opposite side of the hinge means. The synthetic resin container lid according to claim 1 or 2, made of polypropylene. The synthetic resin container lid according to any one of claims 1 to 3, wherein the protruding wall is frustum-shaped. 5. The synthetic resin container lid according to claim 1, wherein a slit valve is attached to the inside of said protruding wall .

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