JPH11227819A - Cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve strength of a cap and prevent a crack from occurring by providing a gate remaining part on a part upper than a top wall, on an internal face of a peripheral wall in a cap equipped with a top wall on a middle of the cylindrical peripheral wall and equipped with a sharp protrusion at the center of an upper face of the top wall. SOLUTION: A tip of a tube is inserted under pressure into an internal space 9 above a peripheral wall 2 of the cap 1, and a closed film at the tip of the tube is broken by a sharp protrusion 4 for unsealing. In this case, the cap 1 has a top wall 3 partitioning its internal space into upper and lower parts is integrally formed with a middle of the peripheral wall 2, and the protrusion 4 is formed to protrude from the center of an upper face of the top wall 3. In addition, a female screw 5 which can be threaded with a container mouth is formed on an internal face of the peripheral wall 2 on a lower part than the top wall 3. In this case, a gate remaining part 6 is provided on an upper part from the top wall 3 on the internal face of the peripheral wall 2, thereby preventing a sink mark from occurring at the time of injection-molding the cap to improve strength of the cap 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap to be fitted on a tube for filling creamy medicines, cosmetics, and the like. More specifically, the present invention relates to a female screw portion into which a male screw portion of a tube is screwed, and an unused screw portion. And a projection that breaks the closing membrane of the tube.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional cap 50 has a top wall 52 provided at an intermediate portion of a cylindrical peripheral wall 51, a sharp projection 53 provided at the center of the upper surface of the top wall, and an inner surface of the peripheral wall. Among them, a female screw portion 54 is provided below the top wall, and the gate remaining portion 55 protrudes upward from the peripheral edge of the upper surface of the top wall. On the other hand, a tube 57 for screwing this cap
Usually, the tip of the tube is covered with a closing film 58 to protect the contents until use, so when using it, the tip of the tube is deeply inserted into the internal space above the top wall. It was necessary to pierce and break the closing membrane by pressing it against the projection.

[0003]

However, in the conventional cap, when the remaining gate portion becomes large, even if an attempt is made to break the closing film with the projection, the tip of the tube hits the remaining gate portion, and the tip of the tube is left. Can not insert deeply,
In some cases, the closure film could not be broken, in which case it was necessary to cut off the remaining gate. However, since the remaining gate is provided on the top wall, there is a problem that it is difficult to cut off the gate. Also, because the remaining gate portion is formed on the top wall, sink marks may be formed on the lower surface of the top wall. In this case, even if the cap is screwed into the tube, the tip of the tube at the sink mark portion may be capped. The contents did not come into contact with the wall, and the contents sometimes leaked to the outside through the gap of the screw.

[0004] The conventional cap has two structural defects in addition to the above-mentioned structural defects that cause the contents to leak out. One of them is a structure in which the lower surface of the ceiling wall is formed horizontally as shown in FIG. This cap has a structure in which the tip of the tube comes into contact with the lower surface of the ceiling wall by surface, so the cap must be strongly tightened to make the two surfaces close together, and if the tightening force is insufficient, In some cases, the contents leaked from gaps on both sides.

[0005] As shown in Fig. 5, the corner portion where the lower surface of the top wall and the inner surface of the peripheral wall are continuous and intersects angularly and linearly. The stress was applied to the angular portion of the corner portion 56 to cause a crack, from which the content leaked.

The present invention has been made in view of such conventional problems, and a common solution corresponding to the first to third aspects of the present invention is to prevent leakage of contents filled in a tube. Is to provide a cap that can

[0007] A specific problem to be solved in accordance with the first aspect of the present invention is to provide a cap that does not cause sink marks on the lower surface of the ceiling wall and that can easily cut off the remaining gate portion.

[0008] A specific problem to be solved according to the second aspect of the present invention is to provide a cap having improved sealing performance by pressing the tip of the tube against the top wall by line contact and sealing.

[0009] A specific problem to be solved according to the third aspect of the present invention is to improve the strength of the cap as compared with the conventional one.
An object of the present invention is to provide a structure for preventing occurrence of cracks.

[0010]

Means for Solving the Problems In order to solve this problem, a solution according to the first aspect of the present invention is to provide a ceiling wall at an intermediate portion of an upright cylindrical peripheral wall, and a central portion of an upper surface of the ceiling wall. A cap provided with a female screw on the inner surface of the peripheral wall below the top wall, wherein the cap has a gate remaining portion on the inner surface of the peripheral wall above the top wall. The gate remaining portion is unnecessary material remaining in the gate of the mold for molding the cap, and adheres to the cap body having a shape corresponding to the cavity. If there is a problem with the work that breaks the gate by pressing the closing membrane that covers the tip of the tube against the protruding part, it is necessary to cut off the peripheral wall. It is desirable to provide the gate as close as possible to the upper end of the peripheral wall, but if the residual gate is provided too close to the upper end of the peripheral wall, it will protrude above the upper end of the peripheral wall and impair the appearance. Optimally, it is provided at a position.

[0011] In another aspect of the present invention, a top wall is provided at an intermediate portion of an upright cylindrical peripheral wall, and a sharp projection is provided at a central portion of an upper surface of the top wall. In the cap provided with a female screw portion below the top wall, the lower surface of the top wall is formed in a convex shape centering on the central portion, and the inner peripheral corner at the distal end of the tube contacts the lower surface. It is characterized by the following. The convex shape is a shape in which the central portion is low and gradually increases toward the outer peripheral edge, for example, a shape such as a lower surface of a sphere or a conical surface having a sharp lower portion.

Further, a solution corresponding to the third aspect of the present invention is to provide a ceiling wall at an intermediate portion of an upright cylindrical peripheral wall,
In a cap provided with a sharp projection at the center of the upper surface of the top wall and having a female screw portion on the inner surface of the peripheral wall below the top wall, the entire corner portion where the lower surface of the top wall and the inner surface of the peripheral wall are continuous. The circumference is formed in a concave curved shape.
The term “concave curved surface” as used herein refers to a state in which there are no angular portions, and if described in terms of a cross-sectional shape obtained by cutting the cap in the vertical direction, the tube screwing space (the inner space below the ceiling wall) is the center. , Bulging outward.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment of a cap 1 according to the present invention, as shown in FIG.
A top wall 3 which is continuous with an intermediate portion of the peripheral wall 2 and vertically partitions the internal space of the peripheral wall 2; a sharp projection 4 which projects upward from the center of the upper surface of the top wall 3; Partial peripheral wall 2
And a female screw portion 5 provided on the inner surface of the peripheral wall 2. The first feature is that a gate residue portion 6 is provided on the inner surface of the peripheral wall 2 above the top wall 3, and the lower surface of the top wall 3 protrudes downward. The second feature is that it is convex, and the third feature is that the entire circumference of the corner portion 10 where the lower surface of the top wall 3 and the inner surface of the peripheral wall 2 are continuous is concave. It is. The cap 1 is made of a synthetic resin such as polyethylene or polypropylene.

The remaining gate portion 6 projects slightly diagonally upward from the inner surface of the peripheral wall 2 and is provided at an intermediate height between the upper end of the peripheral wall 2 and the top wall 3. The lower surface of the ceiling wall 3 has a curved surface shape on the lower side of the sphere, and its center is the lowest and gradually increases toward the peripheral edge.

The peripheral wall 2 has a shape in which vertical ribs 7 are provided on the entire outer surface thereof at intervals along the circumferential direction. Since the strength of the peripheral wall 2 itself is improved by the vertical ribs 7, even if the gate remaining portion 6 is provided, the sinking does not occur on the peripheral wall 2, and the appearance of the cap 1 can be maintained in a good state.

The above-described cap 1 can be mass-produced by, for example, an injection molding method, and its mold is, as shown in FIG.
A cylindrical main body 21 forming the outer peripheral surface of the peripheral wall; a protrusion forming body 22 disposed above the internal space of the main body 21; and a female screw forming body 23 disposed below the internal space of the main body 21
And an annular body 24 interposed between the inner surface of the lower end portion of the main body 21 and the female screw portion forming body 23 and forming the lower end surface of the peripheral wall. The protrusion forming body 22 is provided with a gate 26 communicating with the cavity 25 inclined from the upper end surface toward a part of the inner surface of the peripheral wall. The gate 26
Is a columnar space that gradually tapers as it approaches the cavity 25.

When the cap 1 is screwed into a metal tube 11 made of aluminum or the like, as shown in FIG.
1 is usually formed horizontally, so that the lower surface of the top wall 3 is pressed on the entire periphery of the inner corner 8 on the inner peripheral side of the tip to come into close contact by line contact. 12 can be reliably prevented.

Further, as shown in FIG.
If the distal end of the tube 11 is inserted into the internal space 9 above the peripheral wall 2, the closing film 13 covering the distal end of the tube 11 is broken by the projection 4. The remaining portion of the gate 6 hinders the tip of the tube 11 from moving into the internal space 9.
If it is not possible to insert it into the hole, it may be cut off using a cutter or the like.

The cap of the present invention is not limited to the above embodiment. For example, the cap 1 having a structure having all three features is optimal for enhancing the effect of preventing the contents 12 from leaking. A structure having any two of the three features or a structure having only one may be used.

[0020]

According to the first aspect of the present invention, the cap has a gate residue on the inner surface of the peripheral wall above the top wall, so that sinks do not occur on the lower surface of the top wall. When screwed into the tube, the entire circumference of the distal end of the tube surely comes into contact with the lower surface of the top wall, and as a result, the contents of the tube can be prevented from leaking. Further, since the remaining gate portion is provided on the inner surface side of the peripheral wall, the operation of cutting off the remaining gate portion can be easily performed.

Further, in the cap according to the second aspect, the lower surface of the top wall is formed in a convex shape with the center portion as a center.
When this cap is screwed into the tube, the entire circumference of the inner corner at the end of the tube comes into line contact with the lower surface of the top wall, and the tip of the tube is pressed strongly against the lower surface of the top wall to ensure close contact. As a result, it is possible to prevent the contents of the tube from leaking out.

Further, in the cap according to the third aspect, since the entire periphery of the corner portion where the lower surface of the top wall and the inner surface of the peripheral wall are continuous is formed in a concave curved surface, there is no angular portion in the corner portion. When this cap is fitted to the tube,
Since the stress is dispersed over the entire corner portion, cracks are less likely to occur in the cap than before, and as a result, the contents of the tube can be prevented from leaking.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a typical embodiment of a cap of the present invention.

FIG. 2 is a longitudinal section showing a mold for molding the cap of the present invention.

FIG. 3 is an enlarged longitudinal sectional view of a main part showing a state in which a top wall of a cap and a distal end of a tube are in close contact.

FIG. 4 is a longitudinal sectional view showing a state in which a sealing film of a tube is pressed against a projection of a cap and broken.

FIG. 5 is a longitudinal sectional view showing a mouth portion of a conventional cap and tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cap 2 Perimeter wall 3 Top wall 4 Projection part 5 Female screw part 6 Remaining gate part 8 Corner part 10 Corner part 11 Tube

Claims (3)

[Claims] A top wall (3) is provided at an intermediate portion of an upright cylindrical peripheral wall (2), and a sharp projection (4) is provided at a center of an upper surface of the top wall (3). In the cap (1) provided with a female screw portion (5) on the inner surface of the peripheral wall (3) below the top wall (3), the gate remaining portion (6) is provided on the inner surface of the peripheral wall (2) above the top wall (3). ). 2. A top wall (3) is provided at an intermediate portion of an upright cylindrical peripheral wall (2), and a sharp projection (4) is provided at a center of an upper surface of the top wall (3). In the cap (1) having a female screw portion (5) on a lower portion of the inner wall of the top wall (3), the lower surface of the top wall (3) is formed in a convex shape with the center portion as the center. A cap characterized in that an inner corner (8) at the distal end of the tube (11) contacts the lower surface. 3. A top wall (3) is provided at an intermediate portion of an upright cylindrical peripheral wall (2), and a sharp projection (4) is provided at a center of an upper surface of the top wall (3). In a cap (1) provided with a female screw portion (5) on a lower portion of the inner wall of the top wall (3), a corner portion (10) where the lower surface of the top wall (3) and the inner surface of the peripheral wall (2) are continuous. A) wherein the entire periphery of the cap is formed into a concave curved surface.