Stackable metal cups with curled sections

Abstract

To provide a stackable metallic cup that can be manufactured at low cost in spite of a curled part and that can make stacked cups to be easily pulled out even if a load is added in the axial direction.SOLUTION: A metallic cup 1 has a cylindrical body part 3 with a closed lower end, and has an opening in the upper end of the body part 3. In the upper end of the cylindrical body part 3, there is formed a curled part 13 which is projecting inward. The inner diameter D of the opening which is defined by the inner tip of the curled part 13 is set larger than a bottom part diameter d which is defined by the bottom end outer face of the cylindrical body part 3, thereby making stacking possible.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a stackable metal cup that can be stored by stacking.

Background Art

[0002] Conventionally, cups made of paper or plastic have been widely used as cup-shaped containers for eating, drinking, etc. Containers formed from these materials are lightweight and easy to mold, so they are inexpensive and suitable for disposable use. However, from the environmental perspective of resource depletion and waste problems in recent years, metal cups have attracted attention. Metal cups have higher strength and durability compared to paper or plastic cups, are suitable for repeated use, and can significantly suppress resource depletion and waste generation.

[0003] However, due to the characteristics of high strength and difficulty in deformation, metal cups have difficulty in stackability. That is, in order to provide stackability, the inner diameter of the upper opening is set larger than the outer diameter of the bottom, and the side wall portion has a tapered shape from the upper end toward the bottom (see, for example, Patent Document 1). However, in such a form, when stacking metal cups, the outer surface of the side wall of the upper cup adheres closely to the inner surface of the side wall of the lower cup, and there is a problem that when a load is applied particularly in the axial direction, the stacked cups are difficult to come off.

[0004] Also, in the case of a metal cup, if a sharp end of the metal is exposed at the upper end portion of the opening, inconveniences such as the sharp end hitting the human body and causing injury during carrying or drinking may occur. In order to prevent such inconveniences, generally, an outward curl portion having a convex shape toward the outside is formed at the upper end of the opening of the metal cup (see, for example, Patent Document 2). However, even when such an outward curl portion is formed, it is necessary to devise curling or the like so that the tip of the curl portion does not contact the human body, and there are problems such as an increase in production cost.

[0005] Furthermore, metal cups are known in which an inwardly convex inward curl portion is formed at the upper end of the opening (see Patent Document 3). However, these metal cups do not have stacking capabilities, and the inward curl portion is formed solely for the purpose of fixing the lid material by heat sealing. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2020-508874 [Patent Document 2] Special Publication No. 2015-506842 [Patent Document 3] Japanese Patent Publication No. 2013-66916 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the object of the present invention is to provide a stackable metal cup that can be manufactured inexpensively while having a curled portion, and that can be easily pulled out even when an axial load is applied. [Means for solving the problem]

[0008] According to the present invention, in a metal cup having a cylindrical body with a closed lower end and an open upper end, The upper end of the cylindrical body is formed with a curled portion that is convex inward, The curled portion has its tip extending from the inside outwards and is located inside the cylindrical body, hidden from view from the outside. The provided metal cup features an opening diameter defined by the inner tip of the curled portion being larger than the bottom diameter defined by the lower end of the cylindrical body, allowing for stacking; a step extending inward is formed in the cylindrical body, and the cylindrical body between the step and the curled portion decreases in diameter towards the bottom; and when stacked, the outer surface of the step of the stacked upper metal cup contacts the upper surface of the curled portion of the lower metal cup, creating a gap between the outer surface of the cylindrical body below the step of the upper metal cup and the curled portion of the lower metal cup, thus maintaining the stacked state.

[0009] In the metal cup of the present invention ,side In cross-section, the curled portion has an inward projection width W in the range of 1 to 5 mm, and an axial length H in the range of 1 to 5 mm. ,but It is suitable. [Effects of the Invention]

[0010] The metal cup of the present invention, like ordinary stackable metal cups, has an inner diameter (opening inner diameter) at the upper end of the side wall forming the hollow portion that is larger than the outer diameter at the lower end of the side wall. When metal cups are stacked, the upper cup enters and is held in the space of the lower cup. However, a major feature of the present invention is that the curled portion formed at the upper end of the opening is oriented inward, in the exact opposite direction to conventional metal cups.

[0011] In other words, since the metal cups of the present invention are stacked with the curled portion at the upper end facing inward, a gap is always formed between the outer surface of the stacked upper cup and the inner surface of the lower cup, originating from the inward curled portion. Therefore, even if an axial load is applied while the cups are stacked, the upper cup can be quickly pulled out.

[0012] Furthermore, because the curled portion faces inward, there is no risk of its tip touching the human body when drinking, eliminating the need for any special measures to prevent the tip of the curled portion from touching the human body. Consequently, the formation of the curled portion is easy, and manufacturing costs can be kept low. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic side cross-sectional view showing an example of a metal cup of the present invention. [Figure 2] A side cross-sectional view showing the stacked metal cups in Figure 1. [Figure 3] A side cross-sectional view showing an enlarged view of the curled portion, which is the essential part of the metal cup of the present invention. [Figure 4] A diagram illustrating a preferred form of the metal cup of the present invention, showing the stacked state. [Modes for carrying out the invention]

[0014] In Figure 1, the metal cup of the present invention, shown as 1 overall, consists of a cylindrical body portion 3 with an open upper end and a bottom portion 5 that closes the lower end of the cylindrical body portion 3. The base 5 typically has an annular contact portion 7, the outside of which is connected to the lower end of the cylindrical body 3 by a bent chime portion 9. The inside of the contact portion 7 is a dome-shaped recess 11. This configuration of the base 5 ensures that the metal cup 1 is stably maintained in its installed (upright) state.

[0015] Furthermore, because the metal cup 1 of the present invention is stackable, as shown in Figure 1, the upper end of the cylindrical body 3 is larger than the lower end, and the overall shape is tapered, with the inner and outer diameters gradually decreasing as it goes downwards.

[0016] The metal cup 1 of the present invention having the above-described basic form is characterized in that a curled portion 13 (hereinafter sometimes referred to as an "inner curled portion") that is convex inward is formed at the upper end. In the metal cup 1 having such an inner curled portion 13, the inner diameter D of the opening at the portion where the inner curled portion 13 protrudes most inward is set larger than the outer diameter (bottom diameter) d at the lower end of the cylindrical body portion 3, whereby stacking becomes possible. As understood from FIG. 2 showing this stacking state, when stacking the metal cup 1 having such an inner curled portion 13, a gap CL is necessarily formed between the outer surface 3a of the cylindrical body portion 3 of the upper metal cup 1a and the inner surface 3b of the lower metal cup 1b. That is, since close contact between the outer surface 3a and the inner surface 3b is effectively avoided, the upper cup 1a can be easily pulled out, and even when a load is applied in the axial direction, the upper cup 1a can be easily pulled out.

[0017] Further, referring to FIG. 3 showing an enlarged view of the inner curled portion 13, since the inner curled portion 13 has a shape that is convex inward, the tip 13a of the curled portion 13 extends at least from the inside toward the outside, and the tip 13a is present inside the cylindrical body portion 3 and is located in a state of being hidden from the outside. That is, without any special device, it is possible to effectively avoid the inconvenience that the tip 13a of the curled portion 13 comes into contact with the human body, and it is possible to avoid an increase in production cost. For example, in the form in which the curled portion 13 is convex outward, since its tip 13a exists outside, when curling, it is necessary to increase the degree of curling and curl until the tip 13a faces upward, or to cover the tip 13 with resin so that the metal is not exposed. Inevitably, it takes time to form the curled portion 13, or a resin material is required, resulting in a high manufacturing cost. However, in the present invention in which the curled portion 13 has a shape that is convex inward, it is possible to avoid the inconvenience caused by the exposure of the tip 13a of the curled portion 13 without increasing the manufacturing cost.

[0018] In the metal cup 1 of the present invention described above, as long as the stackability is not impaired (that is, at least the condition D>d is satisfied), it is desirable that the inner curl portion 13 is small. For example, the inward protruding width W is in the range of 1 to 5 mm, particularly in the range of 1.5 to 3 mm, and the axial length H is in the range of 1 to 5 mm, particularly preferably in the range of 2 to 4 mm. That is, if the inner curl portion 13 is larger than necessary, the stackability will be impaired, or in order to form the curl portion 13, a cup with an unnecessarily high height (the cup before forming the curl portion) has to be molded. In addition, if the curl portion 13 is excessively small, the curl portion 13 itself will become sharp, so the protruding width W and the axial length H should be within the above ranges.

[0019] In the present invention, the metal which is the constituent material of the metal cup 1 may be various metals or alloy materials. For example, it may be aluminum, copper, iron, or an alloy containing these metals, and further may be a surface-treated steel plate such as a tin-plated steel sheet like tinplate or an aluminum plate subjected to chemical conversion treatment. Generally, steel, stainless steel, aluminum, or an aluminum alloy is suitable, but particularly from the viewpoints of light weight and workability, aluminum or its alloy is suitable. Furthermore, the inner surface of the metal cup 1 may be laminated with an organic resin coating. The organic resin coating is a coating derived from coatings such as acrylic coatings, urethane coatings, silicon coatings, fluorine coatings, or a thermoplastic resin such as polyethylene terephthalate (PET), and is provided to suppress corrosion resistance and surface roughness during severe molding processes.

[0020] Also, in the present invention, since the curl portion 13 has a convex form inward, it is preferable that the same organic resin coating as described above is also formed on its outer surface.

[0021] Such a metal cup 1 is manufactured, for example, by punching, drawing, redrawing-drawing, etc., using a thin metal sheet (the inner surface may have the aforementioned organic resin coating), then doming the bottom, followed by washing and drying, baking of the outer surface paint, printing, application and baking of the finishing varnish, application and baking of the inner surface paint, curling, etc. The diameter reduction from the upper end downwards of the cylindrical body 3 can be achieved by performing redrawing multiple times.

[0022] In the metal cup 1 described above, the thickness of the central part of the bottom 5 corresponds to the thickness of the base plate used to form the cup 1, and although it varies depending on the intended use of the cup 1, it generally has a thickness of 0.10 to 0.50 mm. Cylindrical The thickness of the body 3 and the height of the cup (height from the contact point 7 to the upper end of the cylindrical body 3) vary depending on the degree of ironing, and as the ironing rate is gradually increased and the ironing process is performed in multiple stages, Cylindrical The fuselage section 3 is made thinner, and the height H is increased.

[0023] In the present invention described above, in Figures 1 and 2, the cylindrical body portion 3 has a straight tapered wall, but a step extending inward may be formed along the way, or a bent portion may be formed along the way to the extent that stackability is not impaired.

[0024] For example, in the example shown in Figure 4, a step 15 extending inward is formed in the upper part of the cylindrical body 3 (below the inward curl portion 13). When such a step 15 is formed, when stacked, the step 15 of the stacked upper metal cup 1a comes into contact with the inward curl portion 13 of the lower cup 1b and is held in a position where it rests on top of the inward curl portion 13. Therefore, although the aforementioned gap CL is formed, the stacked state is stably maintained.

[0025] The metal cup 1 of the present invention, as described above, has excellent stackability and can be stacked and held in large numbers, making it superior in terms of storage and transportability, and is therefore suitable for use as a container for drinking various beverages, for example. [Explanation of Symbols]

[0026] 1: Metal cup 1a: In the stacked state, the upper cup 1b: In the stacked state, the lower cup 3: Cylindrical Torso 5: Bottom 7: Grounding part 9: Chime Department 11: Dome-shaped recess 13: Curl section 13a: Tip of the curled section 15: Step

Claims

1. A metal cup having a cylindrical body with a closed lower end and an open upper end, The upper end of the cylindrical body is formed with a curled portion that is convex inward, and the tip of this curled portion extends from the inside outward and is located inside the cylindrical body, hidden from view from the outside. The inner diameter of the opening defined by the inner tip of the curled portion is set to be larger than the bottom diameter defined by the lower end of the cylindrical body, allowing for stacking. The cylindrical body portion has a step extending inward, and the cylindrical body portion between the step and the curled portion decreases in diameter as it goes downward. A metal cup characterized in that, when stacked, the outer surface of the stepped portion of the stacked upper metal cup contacts the upper surface of the curled portion of the lower metal cup, and a gap is formed between the outer surface of the cylindrical body below the stepped portion of the upper metal cup and the curled portion of the lower metal cup, thereby maintaining the stacked state.

2. The metal cup according to claim 1, wherein, when viewed in a side cross-section, the curled portion has an inward protrusion width W in the range of 1 to 5 mm and an axial length H in the range of 1 to 5 mm.

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