JPH0458969B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an improvement in a drinking straw for sucking liquid drinks such as milk, and more specifically, the present invention relates to an improvement in a straw for sucking liquid drinks such as milk, and more specifically, the present invention relates to an improvement in a straw for sucking liquid drinks such as milk. Concerning bendable straws.

[Conventional technology]

Conventionally, a number of straws have been proposed, including one described in Japanese Patent Publication No. 33477/1983, which has a large number of circumferential grooves in the longitudinal middle part of the straw to enable expansion, contraction, or bending. ing. These have a V-shaped groove on the outer periphery, and by changing the length of the side part of the groove, one side part is recessed into the other side part and overlaps, reducing the length. Generally, they are designed to be able to maintain a bent or bent state. Recently, the cross-sectional shape of the circumferential groove has been changed to 2.
A telescoping straw formed into a trapezoidal shape having equilateral oblique sides has been proposed as shown in Japanese Patent Application Laid-Open No. 59-20120.

[Problem that the invention seeks to solve]

Conventional extendable or bendable straws generally have an extendable flexible region in which the top of the V-shaped groove protrudes from the outer periphery of the straight portion of the straw, whether the straw is extended or retracted. Therefore, when stretched and inserted into the straw hole of a paper container for liquid drinks such as milk, the protrusion gets stuck, making it difficult to insert, and the disadvantage is that the operation feeling when inserting it into the container is poor. Ta. Furthermore, when straws are sold in a shortened state wrapped in a thin film made of polypropylene, polyethylene, etc. and attached to paper containers, etc., the wrapped straws are visible from the outside, but the flexible region of the straw is visible from the outside. There was a defect that protruded in a jagged manner from the other parts and lacked aesthetic appearance. Furthermore, since the grooves that form the bellows-like flexible parts are independent, each groove changes the state of the slope and expands and contracts randomly and intermittently when the straw expands and contracts, so the straw does not expand and contract smoothly. The drawback was that it had a bad feel. On the other hand, the retractable straw in which the cross-sectional shape of the circumferential groove is formed into a trapezoidal shape with an isosceles oblique side eliminates the drawbacks of the straw having a V-shaped circumferential groove, but the groove is Since each straw is independent, it has the disadvantage that the feeling of operation when expanding and contracting the straw is poor.

The present invention has been made in view of the above-mentioned points, and even when the straw is stretched out and used in the straw hole of a paper container, the jagged protrusion in the middle does not get caught and can be used easily. It is easy to use, has an excellent appearance when folded, for example when sold after being wrapped and attached to a container, and when the user stretches the straw to use it, it stretches smoothly and has a good feel of operation, and when stretched further. It is possible to make the outer diameter the same both when it is retracted and to make the outer periphery smooth when it is retracted, making it easier to handle.It is also possible to increase the expansion and contraction ratio, making it possible to install it in small containers. The purpose of the present invention is to provide a stretchable and flexible straw that is excellent both in terms of production and use by consumers.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a straw made of thermoplastic synthetic resin in which a bellows-shaped flexible part 11 consisting of circumferential grooves 2 is formed in the longitudinal middle part of the straw cylinder 1. , the groove 2
The axial cross-sectional shape of the straw is formed into a trapezoidal shape having isosceles oblique sides 5, 5, and the oblique sides 5, 5 are provided so as to be foldable in the axial direction, and the trapezoidal groove 2 is formed on the outside of the straw. The flexible portion 11 of the straw is formed by forming the straw into a spiral shape.

[Effect]

According to the present invention, when the straw is held in the extended state by holding the left and right sides of the straw and applying force inward in the axial direction of the straw, the thermoplastic synthetic resin that makes up the straw exhibits some elasticity. Therefore, while maintaining the outer diameter and groove diameter (valley diameter), the outer circumference, the isosceles slope portions 5, 5 of the groove, and the valley portion 4 of the groove are partially deformed, while the hypotenuse portions 5, 5 are changed relative to the outer circumference. As the force approaches the right angle and further applies force inward in the axial direction, the hypotenuses 5, 5 finally cross the critical point and enter the inside of the outer periphery, no longer requiring external force. With the inclination in the opposite direction to the oblique side portion, the oblique side portions 5, 5 become stable and in a contracted state. At this time, if the axial dimension of the oblique sides 5, 5 is formed to be half the axial dimension of the valley part 4, the outer peripheries of the opposing oblique sides 5, 5 are in contact with each other. In this state, the flexible portion 11 has a smooth outer peripheral surface having the same outer diameter as when it is expanded. When stretching from a contracted state, it expands through the reverse process described above,
The oblique sides 5, 5 are stabilized by the inclination in the opposite direction to the angle of the oblique sides in the contracted state, the deformed portions of the outer periphery and the groove are restored, and the straw is stabilized in the extended state. In other words, since a straw made of a resin such as polypropylene is not purely plastic, the oblique side of the groove can expand and contract in two stable states. During this expansion and contraction, since the trapezoidal groove is spirally formed on the outer periphery of the straw, when the hypotenuse of a certain part of the trapezoid crosses the boundary point between outward and inward, it will continue to expand and contract. As a result, the slope turns inward or outward, resulting in a stable state and smooth expansion and contraction. In the bent state, half the circumference of the groove in the circumferential direction is extended and the other half is contracted.

In addition, when forming the trapezoidal groove 2 on the outer periphery of the straw, the axial dimension of the isosceles slope portions 5, 5 of the groove is set to be half of the axial dimension of the valley portion 4, as described above. At the same time, if the axial dimension of the trough portion 4 and the axial dimension of the peak portion 3 between the adjacent grooves 2, 2 are made equal, when the straw is shortened, the outer edges of the adjacent peak portions 3, 3 At the same time, the outer edges of the adjacent troughs 4, 4 also come into contact, and the grooves are effectively reduced, so that one pitch of the grooved part becomes 1/3 of the size.

〔Example〕

FIG. 1a is a side view of the main parts of the straw according to the embodiment of the present invention when it is stretched, and FIG. 1b is a cross-sectional view passing through its axis.

This straw is made of thermoplastic synthetic resin such as polypropylene, and a trapezoidal groove 2 having equilateral hypotenuses 5, 5 with an isosceles cross section is formed in the longitudinal middle part of the straw cylinder 1 on the outer circumferential surface of the straw. The flexible portion 11 is formed in a spiral shape with a predetermined length. The isosceles oblique sides 5, 5 of this trapezoidal groove 2 each have an inclination angle θ of 60° with respect to the straw axis, and
The axial dimension of the groove trough 4 is equal to the axial dimension of the peak 3 between the adjacent grooves 2, 2, and the axial dimension of the oblique side portions 5, 5 is equal to that of the trough 4 and the axial dimension of the crest 3 between the adjacent grooves 2, 2, respectively. It is formed to be one half of the axial dimension of the peak portion 3 (see FIG. 3).

FIG. 2a is a side view showing the state when the flexible portion 11 is contracted by applying an inward force in the axial direction to the straw shown in FIG. 1a, and FIG. FIG.

The straw can be changed from the extended state [Fig. 1 a, Fig. 1 b] to the contracted state [Fig. 2 a, Fig. 2 b], or from the contracted state [Fig. 2 a, Fig. 2 b] to the extended state [Fig. 2 a, Fig. 2 b]. In the case of shortening or expanding the straw cylinders 1 and 1 on both sides of the flexible part 11,
When a force is applied inward or outward in the axial direction, the peak portion 3, which is the outer peripheral portion, the oblique side portions 5, 5, and the valley portions 4 of the groove are partially deformed, and the oblique side portion 5,
5 approaches the outer circumference at right angles, and as force is further applied inward or outward in the axial direction, the hypotenuse portions 5, 5 finally cross the critical point and reverse, forming a valley. The outer diameter of the valley at the boundary line between the peak part 3 and the hypotenuse part 5 is restored from the compressed state, and the outer diameter of the valley part at the boundary line between the peak part 3 and the hypotenuse part 5 is restored from the compressed state.
The outer diameter of the is also restored from the expanded state, and the angle of inclination of the hypotenuse 5 is opposite to 60° without the need for external force.
At an angle of 60°, this hypotenuse 5 is stable, and as shown in Fig. 2a,
It is in a shortened or stretched state as shown in FIG. 1b.
At this time, when the slope at a location of the trapezoidal groove 2 crosses the boundary point between outward and inward directions, this continuously spreads to the next point, and the slope becomes inward or outward, resulting in a stable state. In other words, when there are many grooves in the circumferential direction in the flexible part like a conventional telescopic straw, each groove is randomly arranged in a sloped state, whether it is extended or contracted. Since the slope changes continuously, the straw can expand and contract smoothly, compared to the case where the straw is expanded or shortened intermittently. In this case, the straw made of resin such as polypropylene is not purely plastic, and in order to keep the diameter of the valley 4 of the groove and the diameter of the peak 3, which is the outer periphery, constant, the condition of the slope changes one after another, and it restores and expands. Or it becomes stable in the contracted state.

The dimensional relationship when the trapezoidal groove 2 is expanded and contracted is as shown in FIG. 3. When the trapezoidal groove 2 is in the expanded state as shown in FIG.
2l, and the axial dimension of the opposing hypotenuses 5 and 5 is l, then the axial length of each peak and valley when the straw is extended is 6l, as shown in the figure.
On the other hand, when the straw is shrunk, the length in the axial direction at the outer circumference of the straw per pitch is as follows:
As shown in FIG. 2b, the outer edges of the inwardly hidden peaks 4 and valleys 3 of the outer periphery are adjacent to each other,
When contracted, the length in the axial direction at the outer periphery of the straw per pitch is 2l, and the groove-forming portion stretches three times as much when expanded as compared to the contracted state.

FIG. 4 is a side view of the straw shown in FIG. 2a when it is bent. In this case, the outer half of the groove 2 is in an extended state, and the other half, that is, the inner half, remains in a contracted state and is in a bent state.

The above-mentioned method for manufacturing straws with trapezoidal spiral grooves uses a mold with the shape of this groove, covers it with a cylindrical straw before molding, and uses a mold that has the shape of a trapezoidal spiral groove, and then covers the straw with a cylindrical straw that has not yet been molded. This can be easily done by pressing and rolling the grooves at high temperatures.

In the above example, one-third of the total length of the straw
If we make the drinking spout side, one-third the outlet side, and the remaining one-third the groove, this groove can be stretched three times, so if we pull it against the total length of the straw when it is shortened, This will increase the total length of the straw by 66%. In the example, the inclination angle θ of the oblique sides 5, 5 of the grooves with respect to the axis was set to 60°, but if this inclination angle is small, the amount of expansion and contraction of one groove becomes large, but the force applied in the axial direction at this time is growing. Further, if the inclination angle θ is large, the force in the axial direction is small, but the length of expansion and contraction of one groove is also small. However, when the inclination angle of the groove approaches 90°, the stability during expansion and contraction is lost, and the amount of expansion and contraction disappears, meaning that the straw's outer diameter, wall thickness,
It is desirable to appropriately select the inclination angle θ in consideration of the groove pitch, material and operability.

In the example, the axial dimensions of the peaks and valleys of the trapezoidal groove were made equal; however, if the dimensions of the peaks were made slightly larger than the dimensions of the valleys, the expansion/contraction rate would decrease slightly; Since the axial dimension of is one half of the trough dimension, it is difficult to obtain a straw whose outer circumferential surface is straight with no unevenness when contracted as in the example, and which can expand and contract smoothly. Of course, various modifications may be made without departing from the spirit of the present invention.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the shape of the groove constituting the flexible region of the straw is
Not only is the hypotenuse symmetrically trapezoidal and spirally formed on the outer periphery, making it easy to manufacture by rolling, but the flexible region has no protrusions from the outer periphery of the straw, and
When expanding and contracting the straw, the condition of the slope of the trapezoidal groove changes continuously, allowing the straw to expand and contract smoothly, making it easier to use when handling the straw mechanically on a production line, compared to conventional straws with expandable and retractable grooves. It is very easy to handle. In addition, if the axial length of the oblique side is set to half the axial length of the valley, the outer peripheral surface will be smooth, linear, and aesthetically pleasing. When sold by attaching it to a container, it has a much better appearance than conventional straws with bellows. In this case, if the axial lengths of the valley and peak are made equal, the expansion/contraction ratio of the grooved part can be increased to three times that of the conventional one, and can also be used for small paper containers. It has the advantage of being easy to use.

As described above, since the straw can be expanded and contracted smoothly, when the user takes out the straw from the bag that has been compressed and wrapped in the container and stretches it, the user can stretch it smoothly and with a good feeling of operation. When inserting a stretched straw into the straw hole of a paper container for a liquid drink such as milk, unlike conventional straws, there is no protrusion from the outer periphery and the straw can be easily inserted, making it very easy to use.

As described above, the present invention makes it possible to provide a straw with advantages in terms of production, distribution and end users, particularly in terms of its handling and use.

[Brief explanation of drawings]

FIG. 1a is a side view of the main parts of a straw when it is extended, showing one embodiment of the present invention, and FIG.
Fig. 2a is a side view of the straw in Fig. 1a when it is retracted, Fig. 2b is a sectional view of Fig. 2a, and Fig. 3 is a side view of the straw in the stretched state. FIG. 4 is an enlarged sectional view showing the dimensional relationship of each part, and is a side view of the straw shown in FIG. 2a when it is bent. 1... Straw cylinder, 2... Groove, 3... Mountain part between grooves,
4... Valley part of the groove, 5... Oblique side part of the groove, 11... Flexible part,
θ...Inclination angle of the oblique side, l, 2l, 6l... Axial dimension.

Claims (1)

[Scope of Claims] 1. A straw made of thermoplastic synthetic resin in which a bellows-shaped flexible portion 11 consisting of a circumferential groove 2 is formed in the longitudinally intermediate portion of the straw cylinder 1.
The axial cross-sectional shape of the straw is formed into a trapezoidal shape having isosceles oblique sides 5, 5, and the oblique sides 5, 5 are provided so as to be foldable in the axial direction, and the groove 2 is screwed onto the outer periphery of the straw. A straw characterized by being formed into a shape. 2. The straw according to claim 1, wherein the axial dimension of the isosceles hypotenuse portions 5, 5 is each half of the axial dimension of the valley portion 4. 3. Claim 2, characterized in that the axial dimension of the valley portion 4 of the trapezoidal groove 2 and the axial dimension of the peak portion 3 between the adjacent grooves 2, 2 are made equal. Straws as described in section.