JP3255065U - container lid - Google Patents

Abstract

[Problem] To provide a container lid that, even when using a material prone to cracking such as biaxially oriented polystyrene, distributes the external force acting on the container lid without concentrating it on a specific point, thereby suppressing the occurrence of cracks.
[Solution] The container lid L is a container lid made of a synthetic resin sheet that covers the top opening of the container body, and has a top plate portion 1 having a flat portion and side wall portions 2a to 2d extending downward from the periphery of the top plate portion 1, and the side wall portions 2a to 2d have trapezoidal first protrusions 21a to 21f that project outward at predetermined intervals in the circumferential direction, extending upward from the lower end of the side wall portions 2a to 2d to a height that does not reach the upper end.
[Selection Diagram] Figure 1

Description

This invention relates to a container lid that covers the top opening of the container body.

The lids of packaging containers are required to meet specific criteria, including allowing visibility of the food or other contents inside, being lightweight, easy to mold, having sufficient strength, and being crack-resistant. Heat resistance may also be required depending on the circumstances.

To ensure the necessary strength without excessively increasing the thickness of the container lid, and to provide excellent visibility, for example, Patent Document 1 proposes a container lid comprising a polygonal, planar top surface, a hanging surface extending downward from the periphery of the top surface, an inclined side surface extending downward and outward, and a flange extending outward from the inclined side surface. The lower end of the hanging surface and the upper end of the inclined side surface are connected via a horizontal surface extending in the horizontal direction, and the width of this horizontal surface gradually narrows from both corners to the center of the sides along a pair of long sides.

Furthermore, as a lid that does not impair the appearance due to deformation and has sufficient strength against load on the top plate, for example, Patent Document 2 proposes a lid for a packaging container that has a polygonal shape in plan view, comprising a top plate having a flat portion, a side wall portion connected to the top plate, and a flange portion connected to the side wall portion. The lid has anti-slip protrusions provided at the corners of the polygon of the top plate, along each side forming the corner, and a boundary recess is provided at the boundary between the flat portion of the top plate and the anti-slip protrusions, recessed in the direction opposite to the protruding direction of the anti-slip protrusions.

Japanese Patent Publication No. 2019-18869 Japanese Patent Publication No. 2013-67400

Biaxially oriented polystyrene (OPS) is widely used as a material for container lids due to its transparency, rigidity, dimensional stability, heat resistance, and ease of molding. While OPS is significantly less prone to cracking than unoriented polystyrene, it still suffers from brittleness. Cracking is particularly likely to occur in thin-walled sections, corners, and low-temperature environments.

Therefore, the objective of this invention is to provide a container lid that, even when using materials prone to cracking such as OPS, distributes the external force acting on the container lid without concentrating it on specific points, thereby suppressing the occurrence of cracks.

A container lid according to one embodiment of the present invention, which achieves the above objective, is a container lid made of a synthetic resin sheet that covers the upper opening of the container body, and comprises a top plate portion having a flat portion, a side wall portion extending downward from the periphery of the top plate portion, and a first horizontal portion extending horizontally outward from the lower end of the side wall portion. The side wall portion is characterized by having a plurality of first protrusions that are rectangular or semicircular in shape and project outward at predetermined intervals in the circumferential direction, extending upward from the lower end of the side wall portion to a height that does not reach the upper end.

In the container lid with the above configuration, it is preferable that the outward protrusion of the first projection is 1 mm or less.

Furthermore, in the container lid of the above configuration, it is preferable that the shape of the first protrusion, as viewed from a direction perpendicular to the side wall, is trapezoidal.

Furthermore, in the container lid of the above configuration, the top plate portion may have a second projection that protrudes upward to regulate the position of the bottom plate of the container body stacked above it.

Furthermore, in the container lid of the above configuration, it is preferable that, in a plan view, the top plate portion is rectangular, and the side wall portion has a semi-conical first recess projecting inward at each of the four corners.

Furthermore, in the container lid of the above configuration, the lid may further have a first horizontal portion extending horizontally outward from the lower end of the side wall portion, and a skirt portion extending downward from the outer peripheral edge of the first horizontal portion. The skirt portion may have a plurality of second recesses projecting inward at predetermined intervals in the circumferential direction, located a predetermined length below the upper end. When covering the upper opening of the container body, the flange portion formed on the outer peripheral edge of the upper opening of the container body may be fitted between the second recesses and the first horizontal portion.

Furthermore, in the container lid of the above configuration, it is preferable that the synthetic resin sheet is made from polystyrene resin.

According to the container lid of this invention, even when using brittle materials such as OPS, the external force applied to the container lid is distributed without concentrating on specific points, thereby suppressing the occurrence of cracks. Furthermore, it improves the freedom of material selection, enabling the provision of a container lid with sufficient durability while achieving weight reduction and cost savings.

This is a plan view showing one embodiment of a container lid according to the present invention. Figure 1 is a right side view of the container lid. Figure 1 is a rear side view of the container lid. This is a partially enlarged cross-sectional view showing the container lid attached to the container body.

The following describes embodiments of the present invention, but the present invention is not limited to these embodiments. In this specification, numerical ranges indicated using "~" represent ranges that include the numerical values before and after "~" as the minimum and maximum values, respectively. Unless otherwise specified, the materials exemplified below may be used individually or in combination of two or more types.

Figure 1 is a plan view showing one embodiment of the container lid according to the present invention, Figure 2 is a right side view of the container lid of Figure 1, and Figure 3 is a rear side view of the container lid of Figure 1. The container lid L shown in these figures is made of a synthetic resin sheet and, in a plan view, has a long rectangular shape in the front-to-back direction with four rounded corners forming a flat top plate portion 1, side wall portions 2a, 2b, 2c, 2d (hereinafter sometimes collectively referred to as "side wall portion 2") that have a slight outward inclination downward from the periphery of the top plate portion 1, a first horizontal portion 3 extending horizontally outward from the lower end of the side wall portion 2, a skirt portion 4 extending approximately vertically downward from the outer peripheral edge of the first horizontal portion 3, and a second horizontal portion 5 extending slightly horizontally outward from the lower end of the skirt portion 4.

(Top panel 1)
The top plate portion 1 has second protrusions 11a and 11c formed along opposing long sides, and second protrusions 11b and 11d formed along opposing short sides. These second protrusions 11a to 11d serve to regulate the position of the bottom plate of the container body B (shown in Figure 4) stacked on top. In other words, the area enclosed by these second protrusions 11a to 11d is set to be slightly larger than the shape of the bottom plate portion of the container body B (shown in Figure 4).

The cross-sectional shape of the second protrusions 11a to 11d perpendicular to their extension direction is rectangular with rounded upper corners. The height of the second protrusions 11a to 11d is not limited as long as it can regulate the position of the bottom plate of the container body B stacked above, but is generally preferably in the range of 1 mm to 5 mm. In this embodiment, the second protrusions 11a to 11d are continuous ridges, but are not limited to this; they may be discontinuous ridges or hemispherical in shape, etc.

(Side wall section 2)
The side wall portion 2 has long side wall portions 2a and 2c facing each other in the left-right direction, and short side wall portions 2b and 2d facing each other in the front-rear direction. As shown in Figure 2, each of the long side wall portions 2a (2c) has two first protrusions 21a and 21b (21d and 21e) separated by a predetermined length in the front-rear direction. As shown in Figure 3, each of the short side wall portions 2b and 2d has a first protrusion 21c (21f) in the center in the left-right direction. The first protrusions 21a to 21f work to disperse the external force when a force is applied to the container lid L in the vertical direction, preventing the force from concentrating on a specific point on the container lid L, and thus suppressing the occurrence of cracks in the container lid L.

The first protrusions 21a to 21f have a trapezoidal shape when viewed perpendicular to the side wall 2. The lower edges of the first protrusions 21a to 21f coincide with the lower end of the side wall 2, while the upper edges of the first protrusions 21a to 21f do not reach the upper end of the side wall 2. The vertical height of the first protrusions 21a to 21f is not limited as long as it effectively distributes external forces, but it is generally preferable to be in the range of 50% to 90% of the vertical height of the side wall 2. Similarly, the outward projection of the first protrusions 21a to 21f is not limited as long as it effectively distributes external forces, but considering the appearance of the container lid L, it is preferable to be in the range of 1 mm or less. There are no particular limitations on the number and position of the first protrusions 21a to 21f; they can be appropriately determined considering the planar shape and material of the top plate 1.

The side wall portion 2 has semi-conical first recesses 22a, 22b, 22c, and 22d projecting inward at each of its four corners. These first recesses 22a to 22d serve to suppress deformation of the container lid L when force is applied in the front-to-back and left-to-right directions. The shape of the first recesses 22a to 22d is not limited to a semi-conical shape; it may also be semi-cylindrical or other shapes. If the top plate portion 1 has a polygonal shape, it is preferable to provide the first recesses at each corner. The maximum inward projection of the first recesses 22a to 22d is not limited as long as it suppresses deformation of the container lid L, but it is usually preferable to be in the range of 1 mm to 5 mm.

The side wall portion 2 has eight stacking protrusions 23a to 23h that project outward at predetermined intervals in the circumferential direction. The stacking protrusions 23a to 23h serve to prevent the container lids L from interlocking when stacked vertically. Therefore, it is preferable to prepare multiple types of container lids L with different formation positions and numbers of the stacking protrusions 23a to 23h.

The outward protrusion of the stack protrusions 23a to 23h is preferably set to be longer than the outward protrusion of the first protrusions 21a to 21f, and is typically in the range of more than 1 mm and 5 mm or less. Furthermore, the vertical height of the stack protrusions 23a to 23h is preferably set to be lower than the vertical height of the first protrusions 21a to 21f.

(First horizontal section 3 and skirt section 4)
The first horizontal section 3 extends horizontally outward from the lower end of the side wall section 2. The skirt section 4 extends downward from the outer peripheral edge of the first horizontal section 3. The skirt section 4 has a plurality of square pyramidal second recesses 41 that project inward at a predetermined length below the upper end. As shown in Figure 4, the first horizontal section 3 and the skirt section 4 primarily serve to detachably fix the flange section 8 of the container body B when the container lid L is attached to the container body B.

As shown in Figure 4, the outward extension length of the first horizontal portion 3 is approximately the same as the outward extension length of the cylindrical flange portion 8 of the container body B. The vertical length of the skirt portion 4 is longer than the vertical thickness of the flange portion 8 of the container body B, and the vertical length from the first horizontal portion 3 to the second recess 41 is the same as or slightly longer than the vertical thickness of the flange portion 8. The inward protrusion of the second recess 41 is shorter than the outward extension length of the flange portion 8, and is preferably 3 mm or less.

When the container lid L is attached to the container body B, an external force is applied to the container lid L in the direction toward the upper opening 7 of the container body B. The cylindrical flange portion 8 formed on the outer periphery of the upper opening 7 of the container body B then contacts the lower part of the second recess 41 of the container lid L, causing the skirt portion 4 to elastically deform and be pushed outward. After the flange portion 8 has passed the second recess 41, the skirt portion 4 returns to its original state due to elasticity, and the flange portion 8 fits between the second recess 41 and the first horizontal portion 3, stably fixing the container lid L to the container body B (see Figure 4).

When the container lid L is removed from the container body B, an external force is applied to the container lid L in the opposite direction to the above operation, moving it away from the top opening 7 of the container body B. The flange portion 8 of the container body B then contacts the upper part of the second recess 41 of the container lid L, causing the skirt portion 4 to elastically deform and be pushed outward. Afterward, the flange portion 8 detaches from the container lid L beyond the second recess 41, and the skirt portion 4 returns to its original state due to elasticity.

(Second horizontal part 5)
The second horizontal section 5 extends slightly horizontally outward from the lower end of the skirt section 4. The second horizontal section 5 serves to improve the strength of the skirt section 4. The second horizontal section 5 is a part that is easily touched by the user's fingers, and it is preferable that knurling is applied to the periphery of the second horizontal section 5 to prevent finger cuts.

(Manufacturing method)
The container lid L according to the present invention is integrally formed by vacuum forming or vacuum pressure forming of a synthetic resin sheet. Polystyrene, polyethylene terephthalate, polypropylene, polyethylene, etc., can be used as the material for the synthetic resin sheet. Stretched versions of these resins, or those with added foaming agents, can also be used. From the viewpoint of allowing the contents inside the container body B to be visible from the outside, transparency is preferred, and even more preferably, rigidity, dimensional stability, heat resistance, and moldability are also desirable. OPS (biaxially oriented polystyrene), possessing these properties, is more preferable as the material for the synthetic resin sheet. The thickness of the synthetic resin sheet can be appropriately determined based on the shape and size of the container lid L, the material of the synthetic resin sheet, etc., but is generally preferred to be in the range of 0.2 mm to 0.8 mm.

(Other forms of torture)
Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications to the configuration are possible without departing from the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the attached utility model claims.
For example, in the above embodiment, the top plate portion 1 was rectangular, but it may be a polygon such as a triangle or pentagon, or a circle. Also, the shape of the first projection formed on the side wall portion 2 is not limited to a trapezoid, but may be a polygon such as a triangle or pentagon, or a semicircle, etc.

Furthermore, although the container lid L in the above embodiment was externally fitted to the container body B, it may also be internally fitted. Also, the flange portion 8 of the container body B may be cylindrical or flat.

According to the container lid of this invention, even when using a brittle material such as OPS, the external force applied to the container lid is distributed without concentrating on specific points, thereby suppressing the occurrence of cracks.

1 Top plate section 2, 2a, 2b, 2c, 2d Side wall section 3 First horizontal section 4 Skirt section 5 Second horizontal section 7 Top opening 8 Flange section L Container lid B Container body 11a to 11d Second protrusions 21a to 21f First protrusions 22a to 22d First recess 41 Second recess

Claims (7)

A container lid made of a synthetic resin sheet that covers the top opening of the container body,
It has a top plate portion having a flat surface and a side wall portion extending downward from the periphery of the top plate portion,
The container lid is characterized in that the side wall portion has a plurality of first protrusions that are rectangular or semicircular in shape and project outward at predetermined intervals in the circumferential direction, extending upward from the lower end of the side wall portion to a height that does not reach the upper end. The container lid according to claim 1, wherein the outward protrusion of the first projection is 1 mm or less. The container lid according to claim 1, wherein the shape of the first projection, as viewed from a direction perpendicular to the side wall, is trapezoidal. The container lid according to claim 1, wherein the top plate portion has a second projection that protrudes upward, regulating the position of the bottom plate of the container body stacked above it. The container lid according to claim 1, wherein, in a plan view, the top plate portion is rectangular, and the side wall portion has a semi-conical first recess projecting inward at each of the four corners. It further comprises a first horizontal portion extending horizontally outward from the lower end of the side wall portion and a skirt portion extending downward from the outer peripheral edge of the first horizontal portion.
The skirt portion has a plurality of second recesses that protrude inward at predetermined intervals in the circumferential direction, located at a predetermined length below the upper end.
The container lid according to claim 1, wherein, when covering the upper opening of the container body, the flange portion formed on the outer peripheral edge of the upper opening of the container body is fitted between the second recess and the first horizontal portion. The container lid according to claim 1, wherein the synthetic resin sheet is a sheet made from polystyrene resin.