JP4575820B2 - Plastic cap with excellent openability - Google Patents

Description

  The present invention relates to a plastic cap including a cap body fixed to a container mouth portion and an upper lid fixed to the cap body by screw engagement, and more specifically, the upper lid is prevented from being overtightened and the opening torque is increased. The present invention relates to a plastic cap that is effectively prevented and has excellent openability in which the co-rotation of the cap body and the upper lid is effectively prevented.

  Conventionally, a plastic cap comprising a cap main body fitted and fixed to a container mouth portion and an upper lid covering a dispensing opening formed in the cap main body has been applied to a container containing a liquid material or the like. In this type of cap, the upper lid is fixed to the cap main body by an engagement protrusion or by screw engagement (Patent Document 1).

  For plastic caps where the upper lid is fixed to the cap body by screw engagement, in general, the top lid is fixed to the container mouth by setting the upper lid on the cap body, and the pour formed on the cap body at the start of use. After that, the opening is opened and closed only by turning the upper lid, and the upper opening covers the dispensing opening to ensure the sealing performance.

JP-A-8-58816

However, in such a plastic cap in which the upper lid is fixed to the cap body by screw engagement, the cap body before being fixed to the container mouth and the setting state of the upper lid are fitted and fixed to the container mouth and the content liquid is poured. After taking out, the state of the engagement surface of a cap main body and an upper cover differs notably. That is, for example, the threaded portion of the cap main body and the upper lid may get wet by the content liquid, or may be dried while the content liquid is attached. If the screw engaging portion is wet, the cap main body and the upper lid will slip. The cap will be tightened to the state where the upper lid is rotated too much in the closing direction than the setting state of the cap body and upper lid, and if the contents dries in this state, the opening torque when opening the lid is very There was a problem of becoming high.
In addition, if the upper lid is too tightly wound, the cap body rotates with the upper lid when the upper lid is removed, and there is a problem that the upper lid cannot be removed.

Accordingly, an object of the present invention is to prevent over-tightening of the upper lid and prevent an increase in the opening torque in a plastic cap in which the cap body and the upper lid are fixed by screw engagement, and the cap body when the lid is opened. The object is to provide a plastic cap which prevents co-rotation and has an excellent openability.
Another object of the present invention is to provide a plastic cap with excellent productivity that can increase the yield of the material without impairing the strength of the upper lid.

  According to the present invention, the top cover portion includes the top plate portion and the skirt portion, and the engagement portion for fixing to the container mouth portion is formed on the inner surface of the skirt portion, and the outer surface of the top plate portion has the male screw on the outer peripheral surface. The top plate portion formed with the upper lid engaging tube is formed with a cap body formed with a planned opening portion partitioned by a thin portion, and a top surface and a side wall, and the cap body is formed on the inner surface of the side wall. A plastic cap applied to the container mouth in a state where the cap main body and the upper lid are combined with each other at the start end of the male screw formed on the cap main body. Is formed with a cut-off surface, and when the cap main plate and the lower end of the upper cover side wall abut on the female screw of the upper lid, it does not engage with the cut-off surface of the male screw start end, but its vicinity Plastic caps are provided, wherein the stopper is formed on the location.

In the plastic cap of the present invention,
1. The stopper is a gap between the upper and lower female screws,
2. The female screw is formed to the upper side of the side wall than the stopper,
3. The upper lid is made of a resin harder than the cap body,
Is preferred.

The plastic cap of the present invention does not overtighten the upper lid when it is re-closed after being opened once, the co-rotation of the cap body due to overtightening of the upper lid is prevented, and the lid opening is excellent A plastic cap can be provided.
According to the plastic cap of the present invention, the material yield can be improved and a plastic cap excellent in productivity can be provided.

The plastic cap of the present invention comprises a cap main body fixed to the container mouth portion and an upper lid applied to the cap main body by screw engagement. In the screw engagement between the cap main body and the upper lid, The first point is that in the closing direction, the start end of the male screw formed on the cap body and the stopper formed on the female screw of the upper lid are locked to form a locking portion for preventing overtightening. It is the feature.
That is, as described above, in the cap that has been opened once, the upper lid rotates too much than the cap main body and the upper lid are set because the contents adhere to the screw engaging portions of the cap main body and the upper lid. In such a case, when the upper lid is opened again, the opening torque becomes very high, and the cap body rotates with the upper lid. However, in the cap of the present invention, since the above-described locking portion is formed in the screw engagement between the cap main body and the upper lid, the increase in the opening torque due to such overtightening is caused. Therefore, the cap body does not rotate with the upper lid, and the lid opening property is excellent.

Further, in the plastic cap of the present invention, the male screw starting end of the cap body is formed as an upright locking surface that is substantially perpendicular to the upper lid engaging cylinder surface obtained by cutting the male screw in the radial direction. The locking surface reliably engages with the stopper formed on the upper lid, and even if it pivots strongly in the closing direction, it does not get over the stopper formed on the upper lid.
Further, in the plastic cap of the present invention, the locking position of the start end of the male screw of the cap main body and the stopper of the upper lid is in a state of engagement when the cap main body top plate portion and the lower end of the upper lid side wall are in contact with each other. Although it does not stop, the position of the cap body top plate and the lower end of the upper lid side wall slightly swiveled in the closing direction effectively prevents the opening torque from being increased due to overtightening of the upper lid. Yes.
That is, in setting the cap body and upper lid, it is important that no gap is formed between the cap body top plate and the lower end of the upper lid side wall. Therefore, the setting of the cap body and upper lid is defined by the cap body top plate and the lower end of the upper lid side wall. For this reason, it is necessary to provide a slight gap between the locking surface and the stopper so that the locking surface and the stopper do not engage at the setting position.

The plastic cap of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows an example of an upper lid of the plastic cap of the present invention, the left half shows a side view and the right half shows a side sectional view. FIG. 2 shows an example of the cap body of the plastic cap of the present invention. A side view is shown, and FIG. 3 is a side view from the X direction of the cap body shown in FIG. FIG. 4 is a partially enlarged cross-sectional view for showing an engagement state between the locking surface and the stopper.

As apparent from FIGS. 1 to 3, the plastic cap of the present invention roughly covers a cap body 1 fixed to a container mouth (not shown) and covers the cap body 1 by screw engagement. It consists of an upper lid 2.
The cap main body 1 shown in FIGS. 2 to 3 includes a top plate portion 3 and a skirt portion 4. An upper lid engaging tube 5 is formed on the top plate portion 3, and a male screw 6 is provided on a side surface of the upper lid engaging tube 5. Is formed. Further, an upper portion of the upper lid engaging cylinder 5 is formed with a dispensing nozzle 7 continuously, which is not shown, but the top plate portion 3 defined by the upper lid engaging cylinder 5 and the dispensing nozzle 7 is weakened. A planned opening portion that is partitioned by a portion is formed, and although not shown, a gripping portion for breaking the weakened portion is provided in the planned opening portion.

As is apparent from FIG. 3, the male screw 6 formed on the side surface of the upper lid engaging cylinder 5 has a thread 9 whose height and width are gradually reduced at the terminal end 9, whereas the starting end 10 is at the upper lid engagement. A locking surface 11 that is cut substantially perpendicularly to the side surface of the combination cylinder 5 is formed.
As apparent from FIG. 4, the locking surface 11 of the cap body is formed as an upright surface that is cut substantially perpendicularly to the side surface of the upper lid engaging cylinder 5. Without overcoming the stopper, it can be securely engaged with the stopper to effectively prevent over-tightening of the upper lid.
Although not shown, the cap body 1 is formed with an engagement protrusion that engages with the engagement protrusion of the container mouth portion on the inner surface of the skirt portion 4 and an inner ring that hangs down from the inner surface of the top plate portion 3. Thus, the container mouth is fitted and fixed so as to maintain liquid tightness.

On the other hand, the upper lid 2 generally includes a top surface 21 and a side wall 22, and a female screw 23 that engages with the male screw 6 of the cap body is formed on the inner surface of the side wall 22. The female screw 23 of the upper lid 2 is formed with a stopper 24 that locks with the locking surface 11 of the cap body 1 described above.
The stopper 24 is formed by a protrusion formed by filling the groove of the female screw 23. The stopper 24 is in a state in which the cap body 1 and the upper lid 2 are set, that is, the lower end 25 of the side wall 25 of the upper lid 2 is placed on the top plate portion 3 of the cap body. In the abutted state, the cap body is formed at a position that is not in contact with the locking surface 11 of the cap body but in the vicinity thereof. As a result, even if the screw lid gets wet and the upper lid is slippery after being opened once, and the upper lid can turn beyond the setting position of the cap main body and the upper lid, the cap main body at the time when the setting position is slightly passed. Since the locking surface 11 and the stopper 24 of the upper lid are locked, overtightening of the upper lid is effectively prevented.

  In the specific example shown in FIG. 1, the upper lid 2 is formed with a female screw 23 up to the vicinity of the top surface 21 above the position where the stopper 24 is formed, which is not involved in the engagement with the cap body. By forming the female screw over the stopper to the vicinity of the top surface in this way, the upper lid forming material can be reduced, and the side wall reinforcement is formed by forming irregularities by the female screw on the inner surface of the side wall. An effect can be obtained.

  In the plastic cap of the present invention, the position of the stopper of the upper lid is preferably in the vicinity of the cap body and the setting position of the upper lid slightly shifted in the opening direction, depending on the diameter of the cap, but more particularly than the setting position. It is desirable to be at a position shifted by 5 to 30 ° in the opening direction.

The shape of the locking surface formed on the male screw of the cap body is not limited as long as it has an upright surface that can be reliably engaged with the stopper. As shown in FIGS. However, in addition to a surface that is substantially perpendicular to the upper lid engaging cylinder surface, such as a male screw cut in the radial direction, the engaging surface may be inclined in the opening direction with respect to the upper lid engaging cylinder surface. In this case, it is more preferable that the surface of the stopper engaged with the locking surface has a shape inclined by the same angle in the closing direction.
Further, the shape of the stopper is not limited as long as it can be engaged with the locking surface of the cap body, and may be slightly protruded from the inner surface of the upper lid side wall as shown in FIG. Of course, the female screw may be simply buried.

In the plastic cap of the present invention, the cap body and the upper lid are respectively molded by a conventionally known production method such as injection molding or compression molding using a known resin conventionally used for a resin cap such as polyethylene or polypropylene. However, it is preferable that the upper lid is made of a plastic harder than the cap body.
That is, since the weakened part for partitioning the planned opening part is formed in the cap body, it is easy to break the weakened part or is fitted and fixed to the container mouth part by the stopper. While it is preferable to use a relatively soft resin from the standpoints of properties and sealing properties, the upper lid is free from such restrictions, so it is easy to process and is relatively hard with excellent impact resistance even if it is thin. This is because it is desirable to use a resin. Accordingly, it is preferable to use polypropylene or the like for the upper lid, while it is preferable to use polyethylene or the like for the cap body.

An example of the upper cover of the plastic cap of this invention is shown, the left half is a side view, and the right half is a sectional side view. The side view of an example of the cap main body of the plastic cap of this invention. The side view from the X direction of the cap main body shown in FIG. The partial expanded sectional view for showing the engagement state of a locking surface and a stopper.

Explanation of symbols

1 Cap body, 2 Upper lid, 3 Top plate part, 4 Skirt part, 5 Upper lid engaging cylinder,
6 male screw 5, 7 dispensing nozzle, 9 male screw end, 10 male screw start,
11 Locking surface, 21 Top surface, 22 Side wall, 23 Female screw, 24 Stopper 24,
25 Side wall bottom edge.

Claims (4)

A top plate portion and a skirt portion are formed, and an engagement portion for fixing to the container mouth portion is formed on the inner surface of the skirt portion, and an upper lid engagement cylinder having a male screw on the outer peripheral surface is formed on the outer surface of the top plate portion, The top plate section defined by the upper cover engaging cylinder includes a cap body formed with a planned opening section defined by a weakened section, and a top surface and a side wall, and engages with a male screw of the cap body on the inner surface of the side wall. A plastic cap applied to the container mouth in a state where the cap body and the upper lid are combined,
The male screw formed on the cap body has a cut-off surface at the start of the male screw, and the female screw of the upper lid has a male screw start when the cap main plate top plate portion and the lower end of the upper lid side wall are in contact with each other. A plastic cap characterized in that a stopper is formed in the vicinity thereof, although it does not engage with the sharp surface.   The plastic cap according to claim 1, wherein the stopper is formed by filling a screw groove of a female screw.   The plastic cap according to claim 1 or 2, wherein the female screw is formed up to above the side wall rather than the stopper.   The plastic cap according to any one of claims 1 to 3, wherein the upper lid is made of a resin harder than the cap body.

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