cap

Abstract

To provide a cap capable of stably preventing falling.SOLUTION: A cap 1 attached to a cylindrical connector having a male screw, includes: a cylindrical outer cylinder part 10; and a female thread 12 provided on an inner peripheral surface 11 of the outer cylinder part 10 by treating the inner peripheral surface 11 as a valley bottom 12a. The inner peripheral surface 11 has: a taper part 11a in which an inner diameter is gradually reduced from one side in an axial direction toward the other side; and a small diameter part 11b provided on the other side in the axial direction furthermore than the taper part 11a, in which the inner diameter is gradually reduced at a smaller change rate than the taper part 11a from one side in the axial direction toward the other side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cap that is attached to a cylindrical connector having a male thread, such as a female luer lock connector. [Background technology]

[0002] Conventionally, in the medical field, connectors conforming to the ISO80369 series are used to connect various instruments constituting infusion lines for administering medicinal fluids to the human body and enteral nutrition lines. Usually, these connectors are equipped with a luer taper part for mating and a screw for locking. Specifically, a female luer lock connector having a female luer taper part and a male screw is paired with a male luer lock connector having a male luer taper part and a female screw, and the two are connected by inserting the male luer taper part into the female luer taper part to mating, and by screwing the male screw into the female screw.

[0003] Generally, instruments equipped with such connectors are sold with a cap attached to the connector to prevent contamination due to contact with fingers, etc. Furthermore, such instruments are generally sterilized, packaged, transported, stored, etc. with the connector still capped.

[0004] Therefore, caps that are usually attached to such connectors are provided with male or female threads that mesh with male or female threads provided on the connector, and are configured so that the cap will not easily fall off the connector due to the meshing of these threads (see, for example, Patent Document 1). In addition, caps with threads have the advantage that they can be attached and detached more easily and smoothly than caps with locking parts to prevent them from coming off (see, for example, Patent Document 2), because the operation of attaching and detaching a cap to a connector is the same as the operation of connecting / disconnecting connectors.

[0005] However, even in caps with threads, the screw may loosen due to thermal expansion during sterilization or vibration during transportation, causing the cap to fall off from the connector. To address such problems, a known anti-loosening structure may be applied to the screw. For example, as shown in Patent Document 3, by forming the screw of the cap into a tapered shape, it is possible to prevent the screw from loosening without causing any snagging when attaching or detaching the cap. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-348764 A [Patent Document 2] JP 2012-16472 A [Patent Document 3] Japanese Utility Model Application Publication No. 7-38735 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the threads of the connector are set with a relatively large play, and the axial length is short compared to the lead, so if the threads of the cap are simply tapered, the cap may tilt relative to the connector, and the locking effect may not be adequate. In particular, the male threads of the female luer connector may be composed of only two protruding pieces, and it is difficult for the conventional locking structure to provide an adequate locking effect.

[0008] In view of the above circumstances, the present invention aims to provide a cap that can be stably prevented from falling off. [Means for solving the problem]

[0009] The cap of the present invention is a cap to be attached to a cylindrical connector having a male thread, the cap comprising a cylindrical outer tube portion, and a female thread provided on an inner peripheral surface of the outer tube portion with the inner peripheral surface serving as a valley bottom, the inner peripheral surface comprising a tapered portion whose inner diameter gradually decreases from one axial side to the other axial side, and a small diameter portion provided on the other axial side of the tapered portion and whose inner diameter gradually changes from one axial side to the other axial side at a rate of change smaller than that of the tapered portion; The cap has a mating portion that is mated with an inner peripheral surface of the connector, and the mating portion extends from a top plate portion of the cap toward one side in the axial direction beyond the small diameter portion and the tapered portion. .

[0010] According to the cap of the present invention, when the cap is screwed onto the connector, the tapered portion with a large rate of change in the inner diameter reduces the inner diameter, and the tip side of the male thread of the connector can be brought into stable contact with the small diameter portion with a small rate of change in the inner diameter, thereby appropriately generating the necessary frictional force. In other words, the locking effect can be appropriately achieved regardless of the shape of the male thread of the connector, and therefore the cap can be stably prevented from falling off the connector.

[0011] In the cap of the present invention, it is preferable that the small diameter portion is configured so that the inside diameter gradually decreases from one side to the other side in the axial direction at a rate of change smaller than that of the tapered portion.

[0012] According to this, even after the male thread of the connector reaches the small diameter portion, it is possible to increase the frictional force moderately by continuing the engagement, thereby reliably generating the necessary frictional force and reliably preventing the cap from falling off the connector.

[0013] In the cap of the present invention, it is preferable that the inner circumferential surface has a large diameter portion provided on one side of the tapered portion in the axial direction and configured to have an inner diameter equal to or larger than the maximum inner diameter of the tapered portion.

[0014] This makes it easier to insert the connector into the cap when attaching the cap to the connector, and allows the male threads of the connector and the female threads of the cap to begin mating smoothly. Therefore, the tapered portion and small diameter portion reliably prevent the cap from falling off, while also ensuring that workability when attaching the cap is not hindered.

[0015] In the cap of the present invention, it is preferable that the large diameter portion is configured so that the inside diameter gradually decreases from one side to the other side in the axial direction at a rate of change smaller than that of the tapered portion.

[0016] This makes it possible to relatively guide the cap and connector in a direction in which their axes align as the connector is inserted further into the cap, thereby improving workability when attaching the cap to the connector.

[0017] In the cap of the present invention, it is preferable that the cap further comprises a fitting portion that fits into an inner peripheral surface of the connector.

[0018] According to this, while protecting the inner peripheral surface of the connector by the engagement of the engagement part, it is possible to suppress permanent deformation of the connector so that the inner diameter of the connector expands. Specifically, a connector to which a cap is attached is subjected to a compressive force between the small diameter part and the engagement part, which may cause permanent deformation so that the inner diameter expands. However, in the cap of the present invention, the rate of change of the inner diameter in the small diameter part is smaller than that in the tapered part, so that this compressive force does not become excessive even if the cap is screwed in too much. In other words, the cap of the present invention is particularly suitable when it has an engagement part that engages with the inner peripheral surface of the connector. Effect of the Invention

[0019] The cap of the present invention can provide the excellent effect of being able to stably prevent falling off. [Brief description of the drawings]

[0020] [Figure 1] 1A is a side cross-sectional view of a cap according to an embodiment of the present invention, and FIG. [Diagram 2] 4 is an enlarged view showing the shape of the inner circumferential surface of the outer tubular portion and the cross section of the female thread. FIG. [Diagram 3] 11 is a side cross-sectional view showing the cap attached to the connector. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0022] Fig. 1A is a side cross-sectional view of a cap 1 according to one embodiment of the present invention, and Fig. 1B is a bottom view of the cap 1. The cap 1 of this embodiment is attached to a female luer lock connector conforming to ISO80369-7 to protect the connector.

[0023] The cap 1 is made of an appropriate resin such as polypropylene, and includes a cylindrical outer tube portion 10, a cylindrical mating portion 20 arranged inside the outer tube portion 10, and a circular top plate portion 30 connecting the outer tube portion 10 and the mating portion 20.

[0024] The outer tubular portion 10 is a portion that covers the outer periphery of the connector to protect it. An internal circumferential surface 11 of the outer tubular portion 10 is provided with a female thread 12 that meshes with a male thread provided on the connector. The female thread 12 is a double-start trapezoidal thread conforming to ISO80369-7, and is provided with the inner circumferential surface 11 as a root 12a.

[0025] In this embodiment, the inner diameter of the inner circumferential surface 11, which is the valley bottom 12a of the female thread 12, is partially reduced to press against the male thread of the connector, thereby increasing the frictional force between the female thread 12 and the male thread of the connector, thereby achieving an anti-loosening effect. Details of the inner circumferential surface 11 will be described later.

[0026] Eight recesses 13a are provided in the axial direction (the vertical direction in FIG. 1A) on the outer peripheral surface 13 of the outer tube portion 10. The recesses 13a act as anti-slip portions when the cap 1 is attached to the connector by screwing the female thread 12 onto the male thread of the connector.

[0027] The mating part 20 is a part that protects the female luer taper part of the connector by fitting (fitting inside) it. The mating part 20 is configured in the same manner as the male luer taper part conforming to ISO80369-7, and has a mating taper part 21a on the outer circumferential surface 21, the outer diameter of which gradually decreases toward the tip side.

[0028] The top plate portion 30 is a portion that covers and protects the tip surface of the connector. In this embodiment, the top plate portion 30 is configured in an annular shape, and a through hole 40 that penetrates the mating portion 20 and the top plate portion 30 in the axial direction is formed, so that the inside of the connector is not blocked even when the cap 1 is attached.

[0029] FIG. 2 is an enlarged view showing the shape of the inner circumferential surface 11 and the female thread 12 of the outer tubular portion 10 in cross section.

[0030] The inner surface 11 is composed of a tapered portion 11a whose inner diameter gradually decreases from one axial side (the lower side, the opening side in FIG. 2) to the other side (the upper side, the back side in FIG. 2), a small diameter portion 11b provided on the other axial side of the tapered portion 11a, a large diameter portion 11c provided on one axial side of the tapered portion 11a, and a chamfered portion 11d provided on one axial side of the large diameter portion 11c.

[0031] The tapered portion 11a is a tapered portion in which the inner circumferential surface 11 is gradually tapered toward the back side of the female thread 12. In this embodiment, the tapered portion 11a is configured to gradually taper from an inner diameter D1 that is slightly smaller than an inner diameter D0 of the valley bottom 12a of the female thread 12 defined in ISO80369-7 to an inner diameter D2 that is approximately 95% of the inner diameter D1. The taper angle of the tapered portion 11a is approximately 14.25°.

[0032] The small diameter portion 11b is a portion that stably contacts the male thread of the connector. In this embodiment, the small diameter portion 11b is configured so that the inner diameter gradually decreases from one side in the axial direction to the other side at a rate of change smaller than that of the tapered portion 11a. Specifically, the small diameter portion 11b has a taper angle of about 0.5°, and is configured so that the inner diameter slightly decreases from an inner diameter D2 at the boundary with the tapered portion 11a to an inner diameter D3 at the boundary with the top plate portion 30.

[0033] The large diameter portion 11c is a portion for smoothly inserting the connector and starting to screw into the male thread of the connector. In this embodiment, the large diameter portion 11c is configured so that the inner diameter gradually decreases from one side to the other in the axial direction at a rate of change smaller than that of the tapered portion 11a, similar to the small diameter portion 11b. Specifically, the large diameter portion 11c has a taper angle of about 0.5°, and is configured so that the inner diameter slightly decreases from an inner diameter D0 at the boundary with the chamfered portion 11d to an inner diameter D1 at the boundary with the tapered portion 11a.

[0034] The ranges that the tapered portion 11a, the small diameter portion 11b, and the large diameter portion 11c occupy in the axial direction are not particularly limited, and may be set so that the male thread of the connector contacts the small diameter portion 11b when the cap 1 is attached to the connector. In this embodiment, the tapered portion 11a, the small diameter portion 11b, and the large diameter portion 11c are provided so as to divide the axial length L1 of the female thread 12 into approximately three equal parts.

[0035] The chamfered portion 11d is a portion for facilitating the start of insertion of the connector into the outer tube portion 10. In this embodiment, a relatively large chamfered portion 11d is provided between the end face 14 of the outer tube portion 10 and the large diameter portion 11c to prevent the tip of the connector from getting caught on the end face 14. The taper angle of the chamfered portion 11d is approximately 90°.

[0036] The female thread 12 is configured such that only the inner diameter of the root 12a changes due to the configuration of the inner peripheral surface 11 described above. That is, the inner diameter D4 of the crest 12c of the thread 12b of the female thread 12 is constant over substantially the entire area. In this embodiment, by configuring the female thread 12 in this manner, the torque required for attaching and detaching the cap 1 is prevented from becoming excessively large.

[0037] Fig. 3 is a side cross-sectional view showing the state in which the cap 1 is attached to the connector 100. Note that in Fig. 3, the illustration of the elastic deformation of the cap 1 and the connector 100 is omitted, and the cap 1 and the connector 100 are illustrated overlapping each other in a state in which they are not elastically deformed.

[0038] The connector 100 is a type of female luer lock connector conforming to ISO80369-7 and is configured in a cylindrical shape. An inner peripheral surface 101 of the connector 100 is provided with a female luer taper portion 110 that fits with a male luer taper portion of a male luer lock connector. The tip side (upper side in FIG. 3) of the outer peripheral surface 102 of the connector 100 is provided with a male thread 120 that is a double-start trapezoidal thread that meshes with a female thread of the male luer lock connector. The connector 100 is also made of an appropriate resin, such as polyvinyl chloride.

[0039] The cap 1 is attached by inserting the connector 100 into the cap 1 from the opening side of the cap 1 and screwing the female screw 12 into the male screw 120. As described above, in this embodiment, the large diameter portion 11c is provided, so that the female screw 12 and the male screw 120 can be smoothly screwed together even when attachment is performed by an automatic machine, for example.

[0040] Specifically, in this embodiment, the large diameter portion 11c is provided with an inner diameter equal to or larger than the maximum inner diameter D1 of the tapered portion 11a, which facilitates insertion of the connector 100 into the cap 1 and reduces frictional resistance at the start of screwing. Also, by configuring the large diameter portion 11c to have a smaller diameter toward the back side, the cap 1 and the connector 100 are relatively guided so that their axes substantially coincide with each other as the insertion amount of the connector 100 increases, and screwing starts and progresses smoothly.

[0041] As the female thread 12 and the male thread 120 are engaged, the engagement portion 20 is inserted into the connector 100. Furthermore, as the tapered portion 11a comes into contact with the male thread 120, a pressing force is applied to the cap 1 and the connector 100 due to the restoring force of the elastic deformation, and the frictional force between them increases. Then, after the tip side of the male thread 120 reaches the small diameter portion 11b, the engagement tapered portion 21a of the engagement portion 20 is appropriately fitted in close contact with the female luer tapered portion 110, thereby completing the attachment of the cap 1 to the connector 100.

[0042] Since the taper angle of the small diameter portion 11b is smaller than that of the tapered portion 11a, when the thread 121 of the male screw 120 reaches the small diameter portion 11b, the top surface 121a of the thread 121 of the male screw 120 comes into contact with the small diameter portion 11b. In other words, by making the taper angle smaller, the small diameter portion 11b is configured to come into contact with the top surface 121a rather than the corner of the thread 121 of the male screw 120.

[0043] As a result, the cap 1 is stably supported by the connector 100 through contact between the surfaces, making it possible to suppress inclination of the cap 1 relative to the connector 100. In addition, since the stress generated at the contact portion is reduced due to contact between the surfaces, it is possible to suppress permanent deformation at the contact portion (plastic deformation at the time of attachment and creep deformation thereafter). In other words, the cap 1 can appropriately contact and press against the connector 100, generating an appropriate frictional force between the two, making it possible to appropriately exert an anti-loosening effect.

[0044] Furthermore, since the small diameter portion 11b is configured to have a smaller diameter toward the back side, it is possible to further increase the pressing force between the male screw 120 and the small diameter portion 11b by further advancing the screw-fitting after the male screw 120 reaches the small diameter portion 11b. Generally, a certain degree of molding error occurs in the cap 1 and the connector 100, but in this embodiment, the pressing force can be adjusted according to the degree of progress of the screw-fitting, so that it is possible to reliably achieve the anti-loosening effect regardless of the presence or absence of molding error.

[0045] Furthermore, the small diameter portion 11b has a small taper angle, i.e., the rate of reduction of the inner diameter toward the back side is small, so that even if the screwing is excessively advanced, the pressing force generated between the small diameter portion 11b and the male thread 120 does not become excessive. As a result, the cap 1, while having the fitting portion 20, is unlikely to cause permanent deformation that would expand the diameter of the female luer taper portion 110.

[0046] Specifically, due to the presence of the fitting portion 20, the tip of the connector 100 is subjected to a compressive force between the small diameter portion 11b and the fitting portion 20, and if this compressive force is excessive, the female luer taper portion 110 is permanently deformed so as to expand in diameter. If permanent deformation occurs in the female luer taper portion 110 due to the fitting of the fitting portion 20, a connection failure may occur when connecting the connector 100 to a male luer lock connector. In this embodiment, since the taper angle of the small diameter portion 11b is small, even if the cap 1 is screwed in excessively, the compressive force applied to the connector 100 is not excessive, and permanent deformation in the female luer taper portion 110 is suppressed.

[0047] In this way, in the cap 1 of this embodiment, the taper portion 11a with a large taper angle (large rate of change in inner diameter) is provided on the inner peripheral surface 11 of the outer tube portion 10 which is the valley bottom 12a of the female thread 12, and the small diameter portion 11b with a smaller taper angle (small rate of change in inner diameter) than the taper portion 11a is provided on the inner side of the taper portion 11a, thereby making it possible to appropriately achieve the anti-loosening effect by reducing the diameter of the valley bottom 12a of the female thread 12. In addition, while having the fitting portion 20, it is possible to suppress permanent deformation in the female luer taper portion 110 of the connector 100 which may occur due to excessive screwing of the cap 1.

[0048] The small diameter portion 11b may have an inner diameter that is substantially constant in the axial direction, or may have an inner diameter that gradually increases from one side (opening side) to the other side (rear side) in the axial direction. In other words, the small diameter portion 11b may have an inner diameter that changes at a smaller rate of change (including a rate of change of 0) than the tapered portion.

[0049] In addition, the taper angle of the small diameter portion 11b is not particularly limited, but in order to ensure stable contact with the male thread 120 of the connector 100, it is preferable that it be between 0° and 7°, more preferably between 0° and 4°, and most preferably between 0° and 2°.

[0050] The large diameter portion 11c may be configured to gradually decrease from an inner diameter larger than the inner diameter D0 conforming to the standard of the female thread 12 to the inner diameter D0 from one side to the other side in the axial direction, or the inner diameter may be configured to be substantially constant in the axial direction. The maximum outer diameter of the tapered portion 11a may be the inner diameter D0 conforming to the standard of the female thread 12, or may be an inner diameter larger than the inner diameter D0.

[0051] The tapered portion 11a, the small diameter portion 11b, and the large diameter portion 11c may have an inner diameter change rate that changes in the axial direction, in which case the average rate of change of the inner diameter in the small diameter portion 11b may be smaller than the average rate of change of the inner diameter in the tapered portion 11a. The direction of change of the inner diameter of the small diameter portion 11b (whether the diameter increases or decreases) may change in the axial direction.

[0052] In addition, in this embodiment, the tapered portion 11a, the small diameter portion 11b, and the large diameter portion 11c are provided so as to be continuous with each other, but an appropriate rounded portion may be provided between the tapered portion 11a and the small diameter portion 11b, or between the large diameter portion 11c and the tapered portion 11a.

[0053] Also, a portion having a different configuration from the small diameter portion 11b may be provided on the other side of the small diameter portion 11b in the axial direction. Also, the large diameter portion 11c may be provided only outside the range of the female thread 12, or the large diameter portion 11c may be omitted and only the tapered portion 11a and the small diameter portion 11b may be provided. Also, the cap 1 may not include the engagement portion 20, and may not include the through hole 40.

[0054] Although the embodiment of the present invention has been described above, the cap of the present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the gist of the present invention. For example, the shape and arrangement of each part of the cap 1 are not limited to the shapes and arrangements shown in the above-mentioned embodiment, and any shape and arrangement can be adopted. Furthermore, the cap 1 may be attached to a connector that complies with a standard other than ISO80369-7.

[0055] Furthermore, the actions and effects shown in the above-described embodiments are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to these. [Explanation of symbols]

[0056] 1 Cap 10 Outer cylinder 11 Inner surface 11a Tapered section 11b Small diameter section 11c Large diameter section 12 Female thread 12a Female thread root 20 Engagement part 100 Connectors 120 Male thread

Claims

1. A cap to be attached to a cylindrical connector having a male thread, A cylindrical outer cylinder portion; a female thread provided on an inner circumferential surface of the outer tubular portion, the female thread having the inner circumferential surface as a root; The inner circumferential surface is A tapered portion whose inner diameter gradually decreases from one side to the other side in the axial direction; a small diameter portion provided on the other side of the tapered portion in the axial direction, the small diameter portion having an inner diameter that gradually changes from one side to the other side in the axial direction at a rate of change smaller than that of the tapered portion; A mating portion that is mated with an inner peripheral surface of the connector, The engagement portion extends from a top plate portion of the cap toward one side in the axial direction, beyond the small diameter portion and the tapered portion. A cap characterized by:

2. The cap according to claim 1, The cap is characterized in that the small diameter portion is configured such that the inner diameter gradually decreases from one axial side to the other axial side at a rate of change smaller than that of the tapered portion.

3. The cap according to claim 1 or 2, The cap is characterized in that the inner circumferential surface has a large diameter portion provided on one side of the tapered portion in the axial direction and configured to have an inner diameter equal to or larger than the maximum inner diameter of the tapered portion.

4. The cap according to claim 3, The cap is characterized in that the large diameter portion is configured such that the inner diameter gradually decreases from one axial side to the other at a rate of change smaller than that of the tapered portion. The indwelling needle assembly is characterized in that

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