cap

Abstract

The present invention provides a cap that reduces the pain felt by the user's fingers when opening and closing the cap, while also preventing a decrease in production efficiency. [Solution] The cap is a cap that can be detachably attached to a container that holds contents, and comprises a frustoconical base that extends in a first direction with respect to a central axis extending in a first direction, and whose radial dimension decreases towards one side in the first direction, and ribs that project radially outward from the side surface of the base. The ribs extend in a direction inclined circumferentially with respect to the first direction. The radial distance between the radially outward end of one end of the rib in the first direction and the central axis is shorter than the radial distance between the radially outward end of the other end of the rib in the first direction and the central axis. The radial outer edge is located radially inward as it moves from the other side in the first direction to one side in the first direction.

Description

Technical Field

[0001] The present invention relates to a cap.

Background Art

[0002] There is known a cap having a knurl that protrudes radially from the outer peripheral surface of a cylindrical tubular portion extending in the vertical direction and extends in the vertical direction (for example, Patent Document 1). In such a cap, when opening and closing the cap, the user's finger catches on the knurl, resulting in a strong gripping force. Therefore, the user can easily open and close the cap.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, compared with a cap in which the knurl extends in the vertical direction, a cap in which the knurl extends in a direction intersecting the vertical direction is easier to open and close, and it is easier to reduce the pain felt by the user's finger when opening and closing the cap. However, when molding a cap in which the knurl extends in a direction intersecting the vertical direction by injection molding using two molds that slide in the vertical direction, when moving one mold that forms the shape of the knurl in the vertical direction to open the mold, such one mold is likely to get caught on the knurl in the vertical direction. Therefore, there was a risk that the production efficiency of the cap would decrease.

[0005] The present invention has been made in consideration of the above points, and one of the objectives is to provide a cap that can reduce the pain felt by the user's finger when opening and closing the cap and can suppress a decrease in production efficiency.

Means for Solving the Problems

[0006] The present invention includes the following configuration. [1] A cap that can be detachably attached to a container for holding contents, comprising: a frustoconical base extending in a first direction with respect to a central axis extending in a first direction, the radial dimension decreasing toward one side in the first direction; and ribs projecting radially outward from the side surface of the base, wherein the ribs extend in a direction inclined circumferentially with respect to the first direction, the radial distance between the radially outward end of one end of the rib in the first direction and the central axis is shorter than the radial distance between the radially outward end of the other end of the rib in the first direction and the central axis, and the radial outer edge is located radially inward as you move from the other side in the first direction toward one side in the first direction. [2] The cap according to [1], wherein the radial dimension of the rib decreases from one side in the first direction to the other side in the first direction. [3] The cap according to [1] or [2], wherein the outer surface of the rib is curved when viewed from the first direction. [4] The cap according to any one of [1] to [3], wherein the rib is located on one side in the circumferential direction as it extends from one side in the first direction to the other side in the first direction, and when viewed from one side in the first direction, the surface of the rib facing one side in the circumferential direction and the side surface of the base are connected in a curved manner that protrudes radially inward. [5] The cap according to any one of [1] to [4], comprising a plurality of ribs arranged at intervals from one another along the circumferential direction. [6] The cap according to [5], wherein each of the plurality of ribs is arranged at equal intervals in the circumferential direction. [7] The cap according to [5] or [6], wherein each of the plurality of ribs is located on one side in the circumferential direction as it moves from one side in the first direction to the other side in the first direction, and the radially outer end of the end of each of the plurality of ribs on one side in the first direction is located on one side in the circumferential direction than the radially outer end of the end of the other side in the first direction of a rib that is adjacent to it on the other side in the circumferential direction. [Effects of the Invention]

[0007] The present invention provides a cap that can reduce the pain felt by the user's fingers when opening and closing the cap, while also suppressing a decrease in production efficiency. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing a container with a cap according to the embodiment. [Figure 2] This is a perspective view showing the cap of an embodiment. [Figure 3] This is a side view showing the cap of the embodiment. [Figure 4] This is a top view showing the cap of the embodiment. [Figure 5] This is a cross-sectional view showing the cap of the embodiment, and is a VV cross-sectional view of Figure 3. [Figure 6] This is a cross-sectional view showing the cap of the embodiment, specifically a cross-sectional view taken from VI-VI in Figure 3. [Figure 7] This is a cross-sectional view showing the cap of the embodiment, specifically the cross-sectional view taken along line VII-VII in Figure 4. [Figure 8] This is a cross-sectional view showing the cap of the embodiment, specifically the cross-sectional view taken along line VIII-VIII in Figure 4. [Figure 9] This is a cross-sectional view showing the cap of the embodiment, specifically the cross-sectional view taken along line IX-IX in Figure 4. [Figure 10] This is a first cross-sectional view showing the method for molding the cap in the embodiment. [Figure 11] This is a second cross-sectional view showing the method for molding the cap in the embodiment. [Figure 12] This figure shows the evaluation results of the cap of the embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, an example of the cap of the present invention will be shown and described based on the drawings. In the following description, the dimensions and the like of the figures illustrated are merely examples, and the present invention is not necessarily limited thereto, and it can be appropriately modified and implemented without changing the gist thereof. Also, in the following drawings, in order to make each configuration easier to understand, the scale, number, etc. in the actual structure and each structure may be made different.

[0010] In each drawing, the first direction D1 is appropriately shown. In the present embodiment, the first direction D1 is the vertical direction when the container with the cap is erected. Also, the first direction D1 is the direction in which the central axis J of the cap extends. The central axis J appropriately shown in each figure is a virtual axis. In the following description, the side to which the arrow of the first direction D1 points in the first direction D1 (+D1 side) is referred to as "one side of the first direction D1" or "upper side", and the side opposite to the side to which the arrow of the first direction D1 points in the first direction D1 (-D1 side) is referred to as "the other side of the first direction D1" or "lower side".

[0011] In the following description, the radial direction centered on the central axis J is simply referred to as the "radial direction". The side that moves away from the central axis J in the radial direction is referred to as the "outer side in the radial direction", and the side that approaches the central axis J in the radial direction is referred to as the "inner side in the radial direction". In the following description, the circumferential direction centered on the central axis J is simply referred to as the "circumferential direction". The circumferential direction is indicated by an arrow θ in each figure. The side to which the arrow θ points in the circumferential direction (+θ side) is referred to as "one side of the circumferential direction". The side opposite to the side to which the arrow θ points in the circumferential direction (-θ side) is referred to as "the other side of the circumferential direction". One side of the circumferential direction is the side that advances counterclockwise around the central axis J when viewed from above. The other side of the circumferential direction is the side that advances clockwise around the central axis J when viewed from above.

[0012] FIG. 1 is a cross-sectional view showing the container 10 with a cap according to the present embodiment. As shown in FIG. 1, the container 10 with a cap according to the present embodiment is a container that discharges the content R accommodated inside the container 12 from the discharge port 19a of the nozzle 17. The container 10 with a cap includes a container 12 and a cap 20.

[0013] Container 12 houses the contents R. Container 12 has a storage container 13 and a nozzle 17. The storage container 13 is a bottle that houses the contents R. The storage container 13 is cylindrical and extends in the first direction D1. The storage container 13 is open at the upper side. The contents R are not particularly limited. In this embodiment, the contents R are liquids such as hair oil and hair treatment. In this embodiment, the storage container 13 is made of resin. As the material constituting the storage container 13, an elastic synthetic resin such as polyethylene, polyethylene terephthalate, polypropylene, and polyester can be used. The storage container 13 is formed by a molding method such as blow molding, stretch blow molding, and injection blow molding. The storage container 13 has a main body portion 14 and a mouth cylinder portion 15.

[0014] The main body portion 14 is the lower part of the storage container 13. In this embodiment, the main body portion 14 is substantially cylindrical and extends in the first direction D1 about the central axis J. The shape of the main body portion 14 is not particularly limited, and other shapes such as a rectangular cylindrical shape extending in the first direction D1 may be used. The main body portion 14 is open at the upper side. Inside the main body portion 14, the contents R are housed.

[0015] The mouth cylinder portion 15 is cylindrical and extends upward from the upper end of the main body portion 14. In this embodiment, the mouth cylinder portion 15 is substantially cylindrical about the central axis J. The mouth cylinder portion 15 is open at the upper side.

[0016] The nozzle 17 is cylindrical and extends in the first direction D1 about the central axis J. In this embodiment, the nozzle 17 is made of resin. As the material constituting the nozzle 17, polyethylene, polyethylene terephthalate, polypropylene, polyester, etc. can be used. The nozzle 17 has a first cylindrical portion 18 and a second cylindrical portion 19.

[0017] The first cylindrical portion 18 is the lower part of the nozzle 17. The first cylindrical portion 18 is substantially cylindrical, extending in a first direction D1 with respect to the central axis J. The first cylindrical portion 18 surrounds the mouth portion 15 from the radially outer side. The first cylindrical portion 18 is fitted into the mouth portion 15. As a result, the nozzle 17 is fixed to the containment container 13. Furthermore, this seals the containment container 13 and the nozzle 17 in a liquid-tight manner. A male threaded portion 18a extending in the circumferential direction is provided on the outer circumferential surface of the first cylindrical portion 18.

[0018] The second cylindrical portion 19 is a roughly frustoconical cylinder extending in a first direction D1 with respect to the central axis J. The radial dimension of the second cylindrical portion 19 decreases towards the top. The lower end of the second cylindrical portion 19 is connected to the upper end of the first cylindrical portion 18. The upper wall of the second cylindrical portion 19 is provided with a discharge port 19a that penetrates the upper wall in the first direction D1. After the user removes the cap 20 from the container 12, squeezing the container 13 with the discharge port 19a facing downwards will allow an appropriate amount of the contents R to be discharged from the discharge port 19a. The inner diameter of the discharge port 19a is set considering the viscosity of the contents R and the appropriate amount of contents R to be used.

[0019] The cap 20 is a substantially frustoconical cylinder extending in a first direction D1 with respect to the central axis J. The cap 20 is open on the bottom. The radial dimension of the cap 20 decreases towards the top. The cap 20 is detachably attached to the first cylindrical portion 18. Thus, the cap 20 is detachably attached to the container 12. In this embodiment, the cap 20 is made of resin. Polyethylene, polyethylene terephthalate, polypropylene, and polyester can be used as materials for the cap 20. In this embodiment, the cap 20 is molded by injection molding. The cap 20 comprises a base portion 21 and ribs 25.

[0020] Figure 2 is a perspective view showing the cap 20 of this embodiment. Figure 3 is a side view showing the cap 20 of this embodiment. As shown in Figure 2, the base 21 is a substantially frustoconical cylinder extending in a first direction D1 with the central axis J as the center. The radial dimension of the base 21 decreases towards the top, i.e., towards one side of the first direction D1 (+D1 side). The base 21 has a peripheral wall portion 22 and a top wall portion 23.

[0021] As shown in Figure 3, the peripheral wall portion 22 is cylindrical in shape, extending in a first direction D1 with respect to the central axis J, and its radial dimension decreases as it moves upward. The peripheral wall portion 22 has a side surface 22a. The side surface 22a is the outer surface of the peripheral wall portion 22. The side surface 22a is located radially inward as it moves upward. In this embodiment, the side surface 22a is oriented in a direction that is inclined upward from the radially outward side.

[0022] As shown in Figure 1, the top wall portion 23 is plate-shaped and extends in a direction perpendicular to the first direction D1. Viewed from the first direction D1, the top wall portion 23 is circular in shape with the central axis J at its center. The radially outer edge of the top wall portion 23 connects to the upper end of the peripheral wall portion 22.

[0023] As shown in Figures 2 and 3, the rib 25 protrudes radially outward from the side surface 22a of the base 21. The rib 25 extends in a direction inclined circumferentially with respect to the first direction D1. In this embodiment, the rib 25 is located on one side of the circumferential direction (+θ side) as it moves from the upper side, i.e., one side of the first direction D1 (+D1 side), to the lower side, i.e., the other side of the first direction D1 (-D1 side). In this embodiment, the upper end of the rib 25 is connected to the upper-facing surface of the top wall portion 23. The upper end of the rib 25 may be located below the upper-facing surface of the top wall portion 23. In this embodiment, the lower end of the rib 25 is located above the lower end of the base 21. The lower end of the rib 25 may extend to the lower end of the base 21.

[0024] In this embodiment, the cap 20 is provided with a plurality of ribs 25. As shown in Figure 2, in this embodiment, the cap 20 is provided with five ribs 25. The number of ribs 25 provided by the cap 20 may be four or fewer, or six or more. The number of ribs 25 provided by the cap 20 may be one. Each rib 25 is arranged at intervals from one another along the circumferential direction. In this embodiment, each of the plurality of ribs 25 is arranged at equal intervals in the circumferential direction. The circumferential intervals between the plurality of ribs 25 do not have to be equal and may be different from one another. As shown in Figure 3, the upper end of each of the plurality of ribs 25, i.e., the radially outer end of the end on one side (+D1 side) in the first direction D1, is positioned circumferentially to one side (+θ side) than the lower end of the adjacent rib 25 on the other side (-θ side) in the circumferential direction, i.e., the radially outer end of the end on the other side (-D1 side) in the first direction D1.

[0025] Each rib 25 has a first side surface 27 and a second side surface 28. The first side surface 27 is the outer surface of the rib 25 facing the other side in the circumferential direction (-θ side). In this embodiment, the first side surface 27 faces the side that is inclined downward from the other side in the circumferential direction. The second side surface 28 is the outer surface of the rib 25 facing one side in the circumferential direction (+θ side). In this embodiment, the second side surface 28 faces the side that is inclined upward from the one side in the circumferential direction.

[0026] As shown in Figure 1, when the cap 20 is rotated in the other circumferential direction (-θ side) with the nozzle 17 inserted inside the cap 20, the male threaded portion 18a and the female threaded portion 20a are screw-fitted together. This allows the user to attach the cap 20 to the container 12. The user can also remove the cap 20 from the container 12 by rotating the cap 20 attached to the container 12 in one circumferential direction (+θ side). In this way, the user can open and close the cap 20. When the user rotates the cap 20 in the circumferential direction, the user's fingers catch on the rib 25, creating a strong grip. Therefore, the user can easily open and close the cap 20. This improves the usability of the cap 20.

[0027] Figure 4 is a top view of the cap 20 of this embodiment. Figure 4 shows the shape of the upper end of the cap 20 as seen from above. In the following description, the upper end of the cap 20 will be referred to as the upper end portion 20c (see Figure 3). The upper end portion 20c includes the upper ends of each rib 25. Figure 5 is a cross-sectional view of the cap 20 of this embodiment, and is the VV cross-sectional view of Figure 3. Figure 5 shows the shape of a cross-section perpendicular to the central axis J of the intermediate portion 20d (see Figure 3), which is the portion of the cap 20 below the upper end portion 20c. Figure 6 is a cross-sectional view of the cap 20 of this embodiment, and is the VI-VI cross-sectional view of Figure 3. Figure 6 shows the shape of a cross-section perpendicular to the central axis J of the lower end portion (see Figure 3), which is the portion of the cap 20 below the intermediate portion 20d. The lower end portion 20e includes the lower ends of each rib 25. As shown in Figure 3, the upper end portion 20c, the intermediate portion 20d, and the lower end portion 20e are located in this order from top to bottom. In the following explanation, the portion between the upper end 20c and the middle portion 20d of the cap 20 in the first direction D1 will be referred to as the first portion 20f. The portion between the middle portion 20d and the lower end 20e of the cap 20 in the first direction D1 will be referred to as the second portion 20g.

[0028] The first distance L1 shown in Figure 4 is the radial distance between the radially outer end of the upper end of the rib 25, i.e., the end on one side (+D1 side) in the first direction D1 of the rib 25, and the central axis J. The second distance L2 shown in Figure 6 is the radial distance between the radially outer end of the lower end of the rib 25, i.e., the end on the other side (-D1 side) in the first direction D1 of the rib 25, and the central axis J. As shown in Figures 4 and 6, the first distance L1 is shorter than the second distance L2.

[0029] As shown in Figures 4 to 6, at the upper end 20c, middle part 20d, and lower end 20e of the cap 20, the outer surface of the rib 25, which faces radially outward when viewed from the first direction D1, is curved and protrudes radially outward. Although not shown, at the first part 20f and second part 20g of the cap 20, the outer surface of the rib 25 is curved and protrudes radially outward when viewed from the first direction D1. From the above, it can be concluded that in this embodiment, the outer surface of the rib 25 is curved when viewed from the first direction D1. Note that a portion of the outer surface of the rib 25 in the first direction D1 does not have to be curved when viewed from the first direction D1, and may be other shapes such as a rectangular shape or a triangular shape protruding radially outward.

[0030] The first dimension S1 shown in Figure 4 is the radial dimension of the upper end of the rib 25. The second dimension S2 shown in Figure 5 is the radial dimension of the rib 25 at the intermediate portion 20d. The third dimension S3 shown in Figure 6 is the radial dimension of the lower end of the rib 25. As shown in Figures 4 and 5, the second dimension S2 is smaller than the first dimension S1. As shown in Figures 5 and 6, the third dimension S3 is smaller than the second dimension S2. Although not shown, the radial dimension of the rib 25 decreases from the upper end 20c towards the intermediate portion 20d. Although not shown, the radial dimension of the rib 25 decreases from the intermediate portion 20d towards the lower end 20e. From the above, the radial dimension of the rib 25 decreases from the upper side, i.e., one side of the first direction D1 (+D1 side), to the lower side, i.e., the other side of the first direction D1 (-D1 side). Furthermore, the radial dimension of a portion of the rib 25 in the first direction D1 may increase from the top to the bottom.

[0031] As shown in Figures 4 to 6, the shape of each rib 25 at the upper end 20c, middle section 20d, and lower end 20e of the cap 20 is asymmetrical in the circumferential direction when viewed from the first direction D1. More specifically, the inclination of the first side surface 27 is gentler than the inclination of the second side surface 28 when viewed from the first direction D1. In this embodiment, the thickness of the other side (-θ side) of the rib 25 in the circumferential direction is greater than the thickness of the one side (+θ side) of the rib 25 in the circumferential direction. Although not shown, the shape of each rib 25 at the first section 20f and the second section 20g of the cap 20 is asymmetrical in the circumferential direction when viewed from the first direction D1. From the above, it follows that in this embodiment, the shape of the rib 25 is asymmetrical in the circumferential direction when viewed from the first direction D1. Note that the shape of a part of the rib 25 in the first direction D1 when viewed from the first direction D1 may be symmetrical in the circumferential direction.

[0032] As shown in Figure 4, when viewed from above, the upper end of the second side surface 28 of each rib 25 and the side surface 22a of the base 21 are connected in a curved manner that protrudes radially inward. As shown in Figure 5, when viewed from above, the second side surface 28 of each rib 25 and the side surface 22a of the base 21 in the intermediate section 20d are connected in a curved manner that protrudes radially inward. As shown in Figure 6, when viewed from above, the lower end of the second side surface 28 of each rib 25 and the side surface 22a of the base 21 are connected in a curved manner that protrudes radially inward. Although not shown in the illustration, when viewed from above, the second side surface 28 of each rib 25 and the side surface 22a of the base 21 in the first section 20f and the second section 20g are connected in a curved manner that protrudes radially inward. From the above, when viewed from above, that is, from one side in the first direction D1 (+D1 side), the second side surface 28 of the rib 25, that is, the surface facing one side in the circumferential direction of the rib 25 (+θ side), and the side surface 22a of the base 21 are connected in a curved manner that protrudes radially inward.

[0033] Figure 7 is a cross-sectional view of the cap 20 of this embodiment, and is a cross-sectional view taken along line VII-VII in Figure 4. Figure 8 is a cross-sectional view of the cap 20 of this embodiment, and is a cross-sectional view taken along line VIII-VIII in Figure 4. Figure 9 is a cross-sectional view of the cap 20 of this embodiment, and is a cross-sectional view taken along line IX-IX in Figure 4.

[0034] As shown in Figure 7, the radial outer edges 29a and 29b of the cap 20 are located radially inward as you move from the bottom to the top. In this embodiment, the radial outer edge of the cap 20 is the ridge of the cap 20 and is composed of the side surface 22a of the base 21 and the rib 25. As shown in Figure 8, the radial outer edges 29c and 29d of the cap 20 are located radially inward as you move from the bottom to the top. As shown in Figure 9, the radial outer edges 29e and 29f of the cap 20 are located radially inward as you move from the bottom to the top. Although not shown, similarly in this embodiment, the radial outer edge of the cap 20 is located radially inward throughout the entire circumferential direction, from the bottom, i.e., the other side of the first direction D1 (-D1 side), to the top, i.e., the one side of the first direction D1 (+D1 side).

[0035] In this embodiment, "located radially inward as you move from the other side of the first direction D1 toward one side of the first direction D1 (+D1 side)" also includes the case where a part of the radial outer edge of the cap 20 extends linearly toward the first direction D1. That is, "located radially inward as you move from the other side of the first direction D1 toward one side of the first direction D1" means "not including the part that is located radially outward as you move from the other side of the first direction D1 toward one side of the first direction D1."

[0036] Figure 10 is a first cross-sectional view showing the molding method of the cap 20 in this embodiment. Figure 11 is a second cross-sectional view showing the molding method of the cap 20 in this embodiment. Next, the molding method of the cap 20 in this embodiment will be described. As described above, in this embodiment, the cap 20 is molded by injection molding. In this embodiment, as shown in Figure 10, multiple caps 20 are molded in a single injection molding. Therefore, in this embodiment, the cap 20 is molded using a second mold 42, a first mold 41 that is slidable relative to the second mold 42 on the other side (-D1 side) of the first direction D1, and a plurality of cores 43. In the molding method of the cap 20 in this embodiment, the first direction D1 may be vertical or horizontal. In this case, the first mold 41 and the plurality of cores 43 are slidable horizontally relative to the second mold 42.

[0037] The first mold 41 is a mold that holds a plurality of cores 43. The first mold 41 is positioned on the other side (-D1 side) of the first direction D1 than the second mold 42. The first mold 41 is slidable relative to the second mold 42 on the other side of the first direction D1. The first mold 41 is provided with a plurality of holes 41a. Each hole 41a is a hole that penetrates the first mold 41 in the first direction D1. When viewed from the first direction D1, each hole 41a is substantially circular in shape.

[0038] Each core 43 is a mold for forming the inner surface of the cap 20. Each core 43 has different holes 41a passing through it in a first direction D1. Each core 43 has a projection 43a that protrudes to one side (+D1 side) of the first direction D1. Each projection 43a forms different inner surface shapes of the cap 20. Each projection 43a has a first outer surface 43c. The shape of the first outer surface 43c is substantially the same as the shape of the inner surface of the cap 20.

[0039] The second mold 42 is a mold for forming the outer surface of the cap 20. The second mold 42 has a plurality of recesses 42a that are recessed on one side (+D1 side) of the first direction D1. Different protrusions 43a can be inserted into the interior of each recess 42a. Each recess 42a forms different shapes of the outer surface of the cap 20. Each recess 42a forms each rib 25. Each recess 42a has a second inner surface 42c. The shape of the second inner surface 42c is substantially the same as the shape of the outer surface of the cap 20. That is, the second inner surface 42c is located radially inward as you move from the other side (-D1 side) of the first direction D1 toward one side of the first direction D1. The second inner surface 42c and the first outer surface 43c are spaced apart from each other.

[0040] In the molding method for the cap 20 of this embodiment, first, as shown in Figure 10, the first mold 41, the second mold 42, and each core 43 are arranged and the molds are clamped. Next, molten, high-temperature resin is filled between the second mold 42 and the first mold 41 and each core 43 through a gate (not shown). Then, the filled resin is cooled to a predetermined temperature and solidified. This forms the cap 20.

[0041] Next, as shown in Figure 11, the first mold 41 is slid to the other side of the first direction D1 (-D1 side) along with each core 43 and each cap 20 to open the mold. As described above, the radial outer edge of the cap 20 is located radially inward as you move from the other side of the first direction D1 to one side of the first direction D1 (+D1 side). Therefore, as described above, the second inner surface 42c of the second mold 42 is located radially inward as you move from the other side of the first direction D1 to one side of the first direction D1. Thus, when sliding the first mold 41, each core 43, and each cap 20 to the other side of the first direction D1, it is possible to prevent the second inner surface 42c from getting caught on each rib 25. Therefore, when opening the mold, the cap 20 can be easily released from the second mold 42.

[0042] Next, although not shown in the diagram, each core 43 is rotated circumferentially by a motor or the like (not shown) and moved to the other side (-D1 side) of the first direction D1. As a result, when the end of each core 43 on one side (+D1 side) of the first direction D1 moves into the hole 41a, each cap 20 can be released from the first mold 41 and each core 43. Once each cap 20 is released from the first mold 41 and each core 43, the molding of the multiple caps 20 is completed.

[0043] According to this embodiment, the cap 20 is a cap 20 that is detachably attached to a container 12 containing contents R, and comprises a frustoconical cylindrical base 21 that extends in the first direction D1 with a central axis J extending in the first direction D1 as its center, and whose radial dimension decreases towards the upper side, i.e., one side of the first direction D1 (+D1 side), and a rib 25 that protrudes radially outward from the side surface 22a of the base 21, wherein the rib 25 extends in a direction inclined circumferentially with respect to the first direction D1, and the first distance L1, which is the radial distance between the radially outward end of the upper end of the rib 25 and the central axis J, is shorter than the second distance L2, which is the radial distance between the radially outward end of the lower end of the rib 25, i.e., the other side of the first direction D1 (-D1 side), and the central axis J, and the radial outer edge is located radially inward as it moves from the lower side to the upper side. Therefore, as described above, even when the cap 20 is formed by injection molding using a first mold 41, a second mold 42, and multiple cores 43, it is possible to prevent the second inner surface 42c from catching on each rib 25 when sliding the first mold 41, each core 43, and each cap 20 to the other side in the first direction D1. As a result, the cap 20 can be easily released from the second mold 42 when opening the mold, thus preventing a decrease in the production efficiency of the cap 20. Also, as described above, since the cap 20 can be easily released from the second mold 42, it is possible to prevent defects such as scratches from occurring on the outer surface of the cap 20.

[0044] Furthermore, in this embodiment, as described above, the rib 25 extends in a direction inclined circumferentially with respect to the first direction D1. Therefore, compared to a cap in which the rib 25 extends in the first direction D1, it is easier to reduce the pressure applied to the user's fingers when the user rotates the cap 20 in the circumferential direction. Consequently, the pain felt by the user's fingers when opening and closing the cap 20 can be reduced.

[0045] Furthermore, in this embodiment, as described above, the first distance L1 is shorter than the second distance L2. This makes it easier to prevent the second inner surface 42c from catching on the upper side of the cap 20, i.e., the end on one side of the first direction D1 (+D1 side), when the first mold 41, each core 43, and each cap 20 are slid to the other side of the first direction D1 (-D1 side) to open the mold. Therefore, the cap 20 can be more easily released from the second mold 42, and the production efficiency of the cap 20 can be more favorably increased.

[0046] Furthermore, in this embodiment, the cap 20 can be molded using a second mold 42, a first mold 41 that is slidable relative to the second mold 42 in the other side of the first direction D1 (-D1 side), and a plurality of cores 43. As a result, as shown in Figures 10 and 11, multiple caps 20 can be molded in a single injection molding process. Therefore, the production efficiency of the caps 20 can be more favorably increased.

[0047] According to this embodiment, the radial dimension of the rib 25 decreases from the upper side, i.e., one side of the first direction D1 (+D1 side), to the lower side, i.e., the other side of the first direction D1 (-D1 side). Therefore, when molding the cap 20, when the first mold 41, each core 43, and each cap 20 are slid to the other side of the first direction D1 to open the mold, the draft angle of the second mold 42 reduces the distance over which the second mold 42 and the rib 25 rub against each other. As a result, the cap 20 can be more easily released from the second mold 42, and the production efficiency of the cap 20 can be more favorably increased.

[0048] According to this embodiment, the outer surface of the rib 25 is curved when viewed from the first direction D1. Therefore, compared to the case where the outer surface of the rib 25 is rectangular when viewed from the first direction D1, there are no corners on the outer surface of the rib 25, which makes it easier to reduce the pressure applied to the user's fingers when the user rotates the cap 20 in the circumferential direction. Consequently, the pain felt by the user's fingers when opening and closing the cap 20 can be reduced more effectively.

[0049] According to this embodiment, the rib 25 is positioned on one side in the circumferential direction (+θ side) as it moves from the upper side, i.e., one side in the first direction D1 (+D1 side), to the lower side, i.e., the other side in the first direction D1 (-D1 side). When viewed from above, the second side surface 28, i.e., the surface of the rib 25 facing one side in the circumferential direction, and the side surface 22a of the base 21 are connected in a curved manner that protrudes radially inward. Therefore, when the user rotates the cap 20 to the other side in the circumferential direction (-θ side), the user's fingers can easily catch on the rib 25. This makes it easier for the user to rotate the cap 20 to the other side in the circumferential direction. Thus, the usability of the cap 20 can be suitably improved.

[0050] According to this embodiment, the cap 20 is provided with a plurality of ribs 25 arranged at intervals from one another along the circumferential direction. Therefore, compared to a configuration in which the cap 20 is provided with only one rib 25, the user's fingers are more likely to catch on the ribs when the user rotates the cap 20 in the circumferential direction. This makes it easier for the user to rotate the cap 20 in the circumferential direction. Thus, the usability of the cap 20 can be more favorably improved.

[0051] According to this embodiment, each of the multiple ribs 25 is arranged at equal intervals in the circumferential direction. Therefore, compared to a cap with a configuration in which the intervals between the multiple ribs 25 are different, the user's fingers are more likely to catch on the ribs when the user rotates the cap 20 in the circumferential direction. Thus, the usability of the cap 20 can be more effectively improved.

[0052] According to this embodiment, each of the multiple 25 ribs is positioned on one side in the circumferential direction (+θ side) as it moves from the upper side, i.e., one side in the first direction D1 (+D1 side), to the lower side, i.e., the other side in the first direction D1 (-D1 side). The radially outer end of the upper end of each of the multiple ribs 25 is positioned on one side in the circumferential direction than the radially outer end of the lower end of the rib 25 that is adjacent to it on the other side in the circumferential direction (-θ side). As a result, in this embodiment, the radial outer edge of each rib 25 does not overlap in the circumferential direction with the radial outer edge of the adjacent rib 25. If the radial outer edge of each rib 25 overlaps in the circumferential direction with the radial outer edge of the adjacent rib 25, it becomes difficult to position the radial outer edge of the cap 20 radially inward as it moves from the lower side to the upper side. Therefore, when opening the mold during molding of the cap 20, the second mold 42 and the ribs 25 are more likely to get caught in the first direction D1. In contrast, in this embodiment, as described above, the radial outer edge of each rib 25 does not overlap in the circumferential direction with the radial outer edges of adjacent ribs 25 arranged in the circumferential direction. Therefore, the radial outer edge of the cap 20 is more easily positioned radially inward as it moves from the bottom to the top. This makes it possible to more effectively suppress the second mold 42 and the ribs 25 from getting caught in the first direction D1 when the mold is opened during molding of the cap 20. Consequently, the production efficiency of the cap 20 can be more effectively increased.

[0053] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples and can be implemented with appropriate modifications without departing from its essence.

[0054] (Examples 1-2, Comparative Examples 1-3) Figure 12 shows the evaluation results of the cap 20 of this embodiment. According to the specifications shown in Figure 12, caps differing in at least one of the following: the direction in which the ribs extend, the symmetry of the rib shape, and the shape of the radial outer edge of the cap were used as samples for Examples 1-2 and Comparative Examples 1-3.

[0055] In the "Direction in which the rib extends" column of Figure 12, "One side in the circumferential direction" means that the rib is located on one side in the circumferential direction as it extends from the top to the bottom, and "The other side in the circumferential direction" means that the rib is located on the other side in the circumferential direction as it extends from the top to the bottom.

[0056] In the "Symmetry of Rib Shape" column of Figure 12, "Symmetry" means that the rib shape is symmetrical in the circumferential direction when viewed from the first direction D1, and "Asymmetrical" means that the rib shape is asymmetrical in the circumferential direction when viewed from the first direction D1.

[0057] In the "Shape of Radial Outer Edge" column of Figure 12, "A" means that the radial outer edge of the cap is located radially inward as it moves from the bottom to the top, and "B" means that at least a portion of the first direction D1 of the radial outer edge of the cap is located radially outward as it moves from the bottom to the top.

[0058] The material used to construct each sample was polypropylene. Each sample was molded by injection molding using a second mold, a first mold that is slidable relative to the second mold in the other side of the first direction D1 (-D1 side), and multiple cores (see Figure 10).

[0059] [Evaluation Method] The samples from Examples 1-2 and Comparative Examples 1-3 were evaluated for their moldability and the absence of pain when opening and closing the cap.

[0060] (1) Formability During the molding of the samples in Examples 1-2 and Comparative Examples 1-3, the ease of demolding from the second mold when sliding the first mold 41 and each core 43 to the other side (-D1 side) of the first direction D1 to open the mold was evaluated using the following criteria for each sample. × (cross mark): Cannot be easily removed from the mold, or cannot be removed from the mold at all. ○ (circle mark): Easily removable

[0061] (2) No pain when opening and closing the cap For the samples of Examples 1-2 and Comparative Examples 1-3, the caps were opened and closed, and the absence of pain felt on the fingers was evaluated according to the following criteria. 5 points: No pain felt 4 points: I don't feel much pain. 3 points: Neither agree nor disagree 2 points: Slightly painful 1 point: I feel intense pain. Then, the average score from the evaluations of the nine expert panelists was calculated.

[0062] As shown in Figure 12, for Examples 1 and 2, where the radial outer edge of the cap is located radially inward from the lower side, i.e., the other side of the first direction D1 (-D1 side), to the upper side, i.e., one side of the first direction D1 (+D1 side), good moldability results were obtained. This is because, as described above, when sliding the first mold, each core, and each cap to the other side of the first direction D1, the second inner surface of the second mold is prevented from catching on each rib, so the cap can be easily released from the second mold when opening the mold. Therefore, a decrease in production efficiency can be suppressed in the caps of Examples 1 and 2.

[0063] Furthermore, in Comparative Example 1, where the ribs extend in the first direction D1, good results were obtained regarding moldability. In Comparative Example 1, since the ribs extend in the first direction D1, the direction in which the ribs extend is parallel to the direction in which the first mold and each core move. As a result, when the first mold, each core, and each cap are slid to the other side of the first direction D1 (-D1 side), the second inner surface of the second mold is prevented from catching on each rib, which allows the cap to be easily released from the second mold when opening the mold.

[0064] In contrast to these, for Comparative Examples 2 and 3, where at least a portion of the radial outer edge of the cap in the first direction D1 is located radially outward as it moves from the other side of the first direction D1 (-D1 side) to the one side of the first direction D1 (+D1 side), good moldability results were not obtained. This is because, when sliding the first mold, each core, and each cap to the other side of the first direction D1, the second inner surface of the second mold catches on each rib, making it difficult to easily release the cap from the second mold when opening the mold.

[0065] As shown in Figure 12, in Examples 1 and 2, where the ribs extend in a direction inclined from the first direction D1 to the circumferential direction, the average score of the evaluation of painlessness when opening and closing the cap by nine expert panelists was 3.7 points or higher, indicating good results regarding painlessness when opening and closing the cap. This is because, as mentioned above, it is easier to reduce the pressure applied to the expert panelists' fingers when they rotate the cap in the circumferential direction, thereby reducing the pain they feel in their fingers when opening and closing the cap.

[0066] In contrast, for Comparative Example 1, in which the rib extends in the first direction D1, the average score for painlessness when opening and closing the cap by nine expert panelists was 2.7 points, indicating that a favorable result regarding painlessness when opening and closing the cap was not obtained. This is because, when the expert panelists rotate the cap in the circumferential direction, the pressure applied to their fingers tends to increase, making it difficult to reduce the pain felt by the expert panelists' fingers when opening and closing the cap.

[0067] Preferred embodiments of the present invention have been described above with reference to the attached drawings. However, it goes without saying that the present invention is not limited to these examples. As long as the ribs extend in a direction inclined from the first direction to the circumferential direction, and the radial outer edge of the cap is located radially inward as it moves from the other side of the first direction to one side of the first direction, those skilled in the art can obtain the above-described effects based on this indicator. The shapes and combinations of the constituent members shown in the above-described examples are merely examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention.

[0068] For example, the container does not need to have a nozzle, and the cap may be directly attached to the mouth portion of the container. In this case, the cap is detachably attached to the mouth portion by screw-fitting the female thread portion of the cap with the male thread portion provided on the outer surface of the mouth portion.

[0069] Furthermore, as in the above-described embodiment 2, the ribs may be located on the other side in the circumferential direction as you move from one side in the first direction to the other side in the first direction. In this case as well, if the radial outer edge of the cap is located radially inward as you move from the other side in the first direction to one side in the first direction, it is possible to reduce the pain the user feels in their fingers when opening and closing the cap, and to suppress a decrease in production efficiency. [Explanation of Symbols]

[0070] 12...Container, 20...Cap, 21...Base, 22a...Side, 25...Rib, 28...Second side (surface facing one side of the rib in the circumferential direction), D1...First direction, R...Contents, J...Central axis

Claims

1. A cap that is detachably attached to a container that holds its contents, A frustoconical cylindrical base extending in the first direction with a central axis extending in the first direction as its center, and whose radial dimension decreases towards one side of the first direction, A rib protruding radially outward from the side surface of the base, Equipped with, The rib extends in a direction inclined circumferentially with respect to the first direction, The radial distance between the radially outer end of one end of the rib in the first direction and the central axis is shorter than the radial distance between the radially outer end of the other end of the rib in the first direction and the central axis. A cap whose radial outer edge is located radially inward as it moves from the other side of the first direction to the one side of the first direction.

2. The cap according to claim 1, wherein the radial dimension of the rib decreases from one side in the first direction to the other side in the first direction.

3. The cap according to claim 1, wherein, when viewed from the first direction, the outer surface of the rib is curved.

4. The ribs are located on one side in the circumferential direction as you move from one side in the first direction to the other side in the first direction. The cap according to claim 1, wherein, when viewed from one side in the first direction, the surface of the rib facing one side in the circumferential direction and the side surface of the base are connected in a curved manner that protrudes radially inward.

5. The cap according to any one of claims 1 to 4, comprising a plurality of ribs arranged at intervals from one another along the circumferential direction.

6. The cap according to claim 5, wherein each of the plurality of ribs is arranged at equal intervals in the circumferential direction.

7. Each of the plurality of ribs is located on one side in the circumferential direction as it moves from one side in the first direction to the other side in the first direction. The cap according to claim 5, wherein the radially outer end of one end in the first direction of each of the plurality of ribs is positioned circumferentially to one side of the radially outer end of the other end in the first direction of a rib that is adjacent to it in the other circumferential direction.

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