JP7697772B2 - Needleless Connector - Google Patents

Description

The present invention relates to a needleless connector that has a male thread on its outer periphery and can be connected to a lure lock type male connector.

Conventionally, in the medical field, in fluid flow paths for infusions and blood transfusions, needleless connectors that can perform mixed injections using a syringe or connect infusion sets without using metal needles have been used as a type of connecting connector. A needleless connector has a female connecting part equipped with a valve body, and a male thread is formed on the outer circumferential surface of the female connecting part for screwing in a male connector with a luer lock. The specific structure of a conventional needleless connector is disclosed, for example, in International Publication No. WO 2015/156272 (Patent Document 1).

However, when connecting a male connector such as a syringe to the female connection part of a needleless connector, fluid leakage and unintentional disconnection of the connector must be avoided. For this reason, the luer lock of the male connector must be securely fastened and screwed to the female connection part of the needleless connector.

International Publication No. 2015/156272

However, with needleless connectors of conventional construction, there are cases where excessive force is used to tighten the male connector of a syringe or other device tightly into the female connection part of the needleless connector. This can make it difficult to adjust the force and set the correct tightening force, particularly when connections must be made quickly in medical settings.

On the other hand, the inventors have found that in needleless connectors of conventional construction, when tightened with excessively large force, the female connection part can deform so as to stretch in the axial direction (flow path length direction). When such deformation occurs, the component strength of the female connection part of the needleless connector decreases, it becomes difficult to obtain sufficient tightening force from the male and female threads, and there is also a risk of gaps occurring at the screwed portions of the male and female threads, which can lead to fluid leakage.

In particular, in needleless connectors of conventional construction, a structure has been proposed in which a cylindrical support portion extending axially inward from the outer periphery of the valve body is provided for the purpose of ensuring the support strength of the valve body, and the cylindrical support portion is supported by being sandwiched in the thickness direction between an outer retaining portion and an inner retaining portion that constitute the female connecting portion. However, in such a structure, the outer retaining portion, on whose outer periphery the male threads of the female connecting portion are formed, tends to be thin-walled. For this reason, when the male connector is tightened with a large force, deformation such as axial extension is more likely to occur in the outer retaining portion of the female connecting portion.

The problem to be solved by the present invention is to provide a new needleless connector that can suppress problems caused by deformation such as elongation of the female connecting part of the needleless connector even when the tightening force of a male connector such as a syringe that is screwed onto the female connecting part of the needleless connector becomes large.

The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is merely an example, and may be combined with one another as appropriate. The multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various alternative embodiments may be realized.

The first aspect is a needleless connector in which a cylindrical support part extending axially inward in a disk-shaped elastic valve body is sandwiched in the thickness direction between an outer retaining part and an inner retaining part that form a cylindrical opening, a male thread is provided on the outer peripheral surface of the outer retaining part, and a luer lock type male connector can be connected by screwing onto the male thread, in which the axial underside of the thread of the male thread is inclined at an angle within the range of 15 degrees to 40 degrees with respect to the central axis of the opening.

In the needleless connector of this embodiment, the inclination angle of the axial underside of the thread of the male screw formed on the outer retaining part at the opening is set smaller (more gradual) than that of the needleless connector of the conventional structure. When the male connector is fastened with a large force, the female screw formed on the male connector is likely to ride up onto the thread of the male screw formed on the outer retaining part before the cylindrical wall of the outer retaining part reaches the yield point (tensile yield stress) due to the axial fixing force applied to the opening by the female and male screw. Therefore, even if the male connector is fastened with a large force, the cylindrical wall of the outer retaining part is prevented from suddenly undergoing large deformation such as elongation, and an effective fastening state can be maintained. As a result, the tolerance range of the fastening force and fastening amount of the female and male screw required to obtain an appropriate screw fixing force when the male connector is screwed into the opening of the needleless connector is increased, making it possible to easily and reliably connect the male connector to the needleless connector.

The second aspect is a needleless connector in which a cylindrical support part extending axially inward in a disk-shaped elastic valve body is sandwiched in the thickness direction between an outer retaining part and an inner retaining part that form a cylindrical opening, a male thread is provided on the outer peripheral surface of the outer retaining part, and a lure lock type male connector can be screwed into the male thread to be connected, and the entire part of the thread of the male thread that has the maximum height dimension is located above the axial center of the thread of the male thread.

In this needleless connector, the protruding height of the male thread is smaller below the axial center than at its maximum, so that when the female and male threads are screwed together, the female thread is more likely to ride up onto the axial underside of the male thread. Therefore, even if the female and male threads are tightened excessively, the upward force exerted by the female thread on the male thread is kept small, and stretching of the tube wall of the outer retaining part can be prevented.

In a third aspect, in a needleless connector according to the first or second aspect , the upper and lower axial surfaces of the thread of the male screw are both inclined surfaces that slope in a direction approaching the mating surface as they approach the outer periphery, and the thread of the male screw is shaped so as to be biased upward.

In the needleless connector of this embodiment, the inclination angle of the axial lower surface with respect to the central axis is smaller than the inclination angle of the axial upper surface of the male thread with respect to the central axis, so that when the male connector is tightened with a large force, the female thread is more likely to ride up onto the axial lower surface of the male thread. This makes it possible to prevent deformation such as stretching of the cylindrical wall of the outer retaining part of the needleless connector. In addition, because the axial upper surface of the male thread is inclined downward toward the outer periphery, the axial upper surface can guide the movement of the female thread.

The fourth aspect is a needleless connector according to any one of the first to third aspects, in which the thickness dimension of the cylindrical wall of the outer retaining part on which the male thread is formed is 2.0 mm or less.

In this needleless connector, the cylindrical wall of the outer retaining part can be designed to be thin while still ensuring the screw fixing force of the luer lock, which prevents the outer diameter of the needleless connector from becoming too large.

The needleless connector of the present invention can suppress deformation of the tube wall even when a large screw fastening force is applied, and a stable connector connection state can be achieved through screw fastening.

FIG. 1 is a front view showing a needleless connector according to a first embodiment of the present invention; FIG. 2 is a longitudinal sectional view of the needleless connector shown in FIG. FIG. 2 is a vertical cross-sectional view showing a state in which the female thread of a male connector is screwed into the male thread of the needleless connector shown in FIG. FIG. 2 is an explanatory diagram for explaining the results of a comparison between the needleless connector shown in FIG. 1 and a needleless connector of a conventional structure. FIG. 3 is a longitudinal sectional view showing a needleless connector according to a second embodiment of the present invention;

In order to clarify the present invention more specifically, the following embodiment of the present invention will be described in detail with reference to the drawings.

First, Figures 1 and 2 show a needleless connector 10 as a first embodiment of the present invention. The needleless connector 10 of this embodiment is a straight, generally cylindrical plug-shaped connector. It also has a cylindrical opening 12 that protrudes to one axial side (upper side in Figure 2), and a disk-shaped elastic valve body 14 is attached to the upper end (opening end) of the opening 12. The axial direction refers to the up-down direction in Figures 1 and 2, which is the central axial direction of the needleless connector 10. Additionally, upper refers to the upper side in Figures 1 and 2, and lower refers to the lower side in Figures 1 and 2.

More specifically, the housing 16 of the needleless connector 10 is constructed by combining three separate members, each of which is a roughly cylindrical base member 18, an inner holding portion 20, and an outer holding portion 22, in a roughly coaxial manner. The materials of the base member 18, the inner holding portion 20, and the outer holding portion 22 are not limited as long as they are hard synthetic resins, but suitable materials include, for example, polypropylene, polyvinyl chloride, polycarbonate, polyacetal resin (POM), etc.

The base member 18 has a central cylindrical portion 24 that extends vertically in the axial direction and protrudes downward to form a male connector, and a substantially cylindrical peripheral wall portion 26 located on the outer periphery of the central cylindrical portion 24. The central cylindrical portion 24 and peripheral wall portion 26 are connected by a substantially annular upper bottom wall portion 28 that extends perpendicular to the axis. The central cylindrical portion 24 penetrates the center of the upper bottom wall portion 28 in the vertical direction, and the central cylindrical portion 24 protrudes on both sides of the upper bottom wall portion 28 in the vertical direction. In addition, the peripheral wall portion 26 protrudes downward from the upper bottom wall portion 28, and a female thread 30 is formed on the inner circumferential surface of the peripheral wall portion 26.

Furthermore, a generally cylindrical support wall portion 32 protrudes upward from the radially middle portion of the upper surface of the upper bottom wall portion 28. The central cylindrical portion 24 and the support wall portion 32 protrude upward from the upper bottom wall portion 28, forming a generally annular fixing groove 34 that opens upward on the upper surface of the upper bottom wall portion 28.

The inner retaining portion 20 is generally formed in a tapered cylindrical shape with a gradually decreasing diameter going upward, and the lower end of the inner retaining portion 20 is formed as a generally annular base end portion 36 that protrudes outward. The upper end of the inner retaining portion 20 is formed with an annular receiving seat portion 38 that narrows toward the inner periphery, and an annular inner engaging claw 40 that protrudes upward is formed on the inner peripheral edge of the receiving seat portion 38.

The outer retaining portion 22 is generally formed in a stepped cylindrical shape, with a lower large diameter cylindrical portion 42 and an upper small diameter cylindrical portion 44 integrally connected by a stepped annular wall portion 46 that extends in the axially perpendicular direction. That is, the annular wall portion 46 is provided in the axially intermediate portion of the outer retaining portion 22, with the portion below the annular wall portion 46 being the large diameter cylindrical portion 42 and the portion above the annular wall portion 46 being the small diameter cylindrical portion 44. A generally annular fitting groove 48 that opens downward is formed in the radially intermediate portion of the underside of the annular wall portion 46.

The small diameter cylindrical portion 44 is generally tapered cylindrical in shape with a gradually smaller diameter going upward. The upper end of the small diameter cylindrical portion 44 is provided with a generally annular tip wall portion 50 that protrudes toward the inner periphery, and the inner peripheral edge of the tip wall portion 50 is provided with an annular outer engagement claw 52 that protrudes downward in a folded-back manner. A ring-shaped outer retaining groove 54 that opens downward is formed between the small diameter cylindrical portion 44 and the outer engagement claw 52 in the radial direction.

Here, the female connector is formed including the small diameter cylindrical portion 44, and the outer circumferential surface of the small diameter cylindrical portion 44 is formed with a male thread 60 into which a female thread 58 (see FIG. 3 described later) provided on a lure lock type male connector 56 is screwed. The male thread 60 is a double-thread thread that can be connected to the female thread 58 specified in ISO 80369-7 (ISO 594-2), for example. In this embodiment, the male thread 60 is formed over substantially the entire length of the small diameter cylindrical portion 44 in the vertical direction, and specifically, it is formed from slightly above the annular wall portion 46 to a vertical position that substantially corresponds to the protruding tip of the outer engagement claw 52.

Considering the size of a typical luer lock structure, it is preferable that the outer diameter dimension of the small diameter cylindrical portion 44, not including the thread 62 of the male screw 60, is set within the range of 5.0 mm to 7.0 mm. However, in this embodiment, the outer diameter dimension of the small diameter cylindrical portion 44 as a whole gradually increases toward the bottom, and accordingly, the height dimension of the thread 62 of the male screw 60 gradually decreases toward the bottom. As a result, the outer diameter dimension of the apex of the thread 62 of the male screw 60 is approximately constant in the vertical direction in the portion where the male screw 60 is formed.

In this embodiment, each thread of the double-start thread that constitutes the male thread 60 is formed on the outer circumferential surface of the small diameter cylindrical portion 44 with a length of at least half a circumference. Preferably, each thread of the male thread 60 is formed with a length of approximately one circumference. By adopting a double-start thread, it is possible to improve the screw fixing force while suppressing the amount of rotation when fixing the screw compared to a single-start thread.

In this embodiment, the thickness dimension A (see FIG. 2) of the small diameter cylindrical portion 44 at the portion where the male screw 60 is formed is 2.0 mm or less, and A may be 1.0 mm or less, for example. If the thickness dimension A of the small diameter cylindrical portion 44 is greater than 2.0 mm, it may be difficult to ensure the outer diameter dimension of the ISO standard and the inner diameter dimension of the connector inner flow path while ensuring the support structure of the elastic valve body 14 described below. Note that the thickness dimension of the small diameter cylindrical portion 44 refers to the thickness dimension of the cylindrical portion excluding the thread 62 of the male screw 60.

In this embodiment, the thickness of the small diameter cylindrical portion 44 at the bottom wall and the outer peripheral wall of the outer retaining groove 54 is greater than the thickness of the small diameter cylindrical portion 44 in the area where the male thread 60 is formed. In other words, the peripheral wall area where the male thread 60 is formed in the small diameter cylindrical portion 44 is a thin-walled portion 64 that is thinner than the tip opening.

The opening portion 12 is formed by including the inner retaining portion 20 and the outer retaining portion 22 described above, and the elastic valve body 14 arranged in the upper opening of the opening portion 12 is retained at the outer periphery.

The elastic valve body 14 is generally disk-shaped and is made of an elastic material such as rubber or elastomer. A slit 68 is formed in the central portion 66 of the elastic valve body 14, penetrating it in the thickness direction. The shape of the slit 68 is not limited, but may be, for example, a line shape, a cross shape, or a shape extending radially from the center.

The elastic valve body 14 is provided on its outer periphery with a cylindrical support portion 70 that protrudes axially inward (downward in Figs. 1 and 2). The central portion 66 and the cylindrical support portion 70 are connected by an annular connecting portion 72 that extends around the entire circumference, so that the elastic valve body 14 is formed as a single unit.

This annular connecting portion 72 is formed by making the thickness dimension smaller than that of the central portion 66 of the elastic valve body 14, and an outer annular groove 74 and an inner annular groove 76 are formed on the outer peripheral portions of both the inner and outer axial surfaces of the elastic valve body 14, each of which is shaped like a groove extending around the entire circumference in the circumferential direction. These two annular grooves 74, 76 form a constriction in the outer peripheral portion of the elastic valve body 14, and this constriction portion, i.e., the axial distance between the bottoms of the two annular grooves 74, 76, forms the thin-walled annular connecting portion 72.

The shapes of the two annular grooves 74, 76 are approximately corresponding to the outer engaging claw 52 and the inner engaging claw 40, respectively, and the outer and inner engaging claws 52, 40 are fitted into them. A recessed groove portion 78 is formed in the wall portion on the inner circumferential side of the inner annular groove 76, and the inner shape of the recessed groove portion 78 approximately corresponds to the inner circumferential surface shape of the inner engaging claw 40. The recessed groove portion 78 may be formed as a continuous ring in the circumferential direction, or may be provided partially divided in the circumferential direction.

In this embodiment, the cylindrical support portion 70 also protrudes upward from the annular connecting portion 72. That is, the cylindrical support portion 70 is configured to include an upper support portion 80 that protrudes upward from the annular connecting portion 72, and a lower support portion 82 that protrudes downward from the annular connecting portion 72. In addition, an annular flange portion 84 that protrudes toward the outer periphery is integrally formed at the lower end of the lower support portion 82.

In addition, the outer diameter dimension of the upper end of the upper support portion 80 of the elastic valve body 14 is preferably set within the range of 5.0 to 6.5 mm. If this dimension is smaller than 5.0 mm, it may be difficult to insert the luer tip of a standard luer lock type male connector 56 (specified, for example, in ISO 80369-7 (ISO 594-2)) whose outer diameter is standardized to approximately 4.0 mm, while if this dimension is larger than 6.5 mm, the outer diameter of the small diameter cylindrical portion 44 becomes too large, making it difficult to connect to the female thread 58 of a standard luer lock type male connector 56.

The annular base end 36 of the inner retaining portion 20 is fitted into the fixing groove 34 of the base member 18, the lower support portion 82 of the elastic valve body 14 is assembled in an externally inserted state to the inner retaining portion 20, and the outer retaining portion 22 is further assembled in an externally inserted state to the lower support portion 82 of the elastic valve body 14. The lower support portion 82 and flange-shaped portion 84 of the elastic valve body 14 are overlapped in a substantially intimate state to the base member 18, the inner retaining portion 20, and the outer retaining portion 22, and these overlapping surfaces may be bonded or not bonded.

In addition, the inner and outer engagement claws 40, 52 formed on the inner and outer holding parts 20, 22 are pressed into the inner and outer annular grooves 76, 74 of the elastic valve body 14 so as to bite into them. Furthermore, the locking projections protruding from the upper surface of the annular base end part 36 of the inner holding part 20 and the lower surface of the annular wall part 46 of the outer holding part 22 are pressed into the flange-shaped part 84 of the elastic valve body 14 so as to bite into them.

The outer retaining portion 22 is welded to the base member 18 while being pressed against it in the axial direction, and the elastic valve body 14 is assembled and attached to the housing 16. The outer retaining portion 22 and the base member 18 may be fixed to each other by adhesive bonding, concave-convex fitting, or other means instead of or in addition to welding. Also, in FIG. 2, a welding protrusion is shown by a two-dot chain line at the upper end of the support wall portion 32 of the base member 18 that is fitted into the fitting groove 48 of the outer retaining portion 22, but when the outer retaining portion 22 and the base member 18 are welded to each other, the welding portion is not limited.

As a result, in this embodiment, the lower support portion 82 of the cylindrical support portion 70 is supported by being sandwiched between the outer support portion 22 and the inner support portion 20 in the thickness direction, and is preferably supported in a compressed state between the outer support portion 22 and the inner support portion 20 in the radial direction. As a result, the elastic valve body 14 is effectively prevented from falling off from the housing 16.

Here, in this embodiment, the male thread 60 provided on the outer peripheral surface of the small diameter cylindrical portion 44 is a trapezoidal thread in which the cross-sectional shape of the thread 62 is approximately trapezoidal, and the thread 62 has a protruding tip surface 86 that extends approximately parallel to the cylindrical surface around the central axis, and an axial upper surface 88 and an axial lower surface 90 that are inclined from both axial sides of the protruding tip surface 86. These axial upper and lower surfaces 88, 90 are inclined surfaces that are inclined with respect to the axial direction, and approach each other as they approach the outer peripheral side. The inclination angles of the axial upper surface 88 and the axial lower surface 90 are approximately constant over the entire length of the male thread 60. In addition, in FIG. 2, the shape of the thread described in Patent Document 1 is shown by a dashed line as a reference example of a thread shape of a conventional structure.

In this embodiment, in the axial cross section shown in FIG. 2, the inclination angle α (see FIG. 2) of the axial underside 90 with respect to the axial line is smaller than that of the conventional structure, and the inclination angle α is set to 15 degrees or more. If the inclination angle α is smaller than 15 degrees, the engagement force between the male thread 60 and the female thread 58 will be small, making it difficult to obtain a sufficient screw fixing force, or the male connector 56 may easily come off in the axial direction from the needleless connector 10. In addition, the inclination angle α is set to 40 degrees or less. If the inclination angle α is larger than 40 degrees, it may be difficult to suppress deformation such as elongation of the small diameter cylindrical portion 44 in which the male thread 60 is formed in the needleless connector 10 when a large screw tightening force is applied when connecting the male connector 56 described later.

Furthermore, in this embodiment, in the axial cross section shown in FIG. 2, the inclination angle β (see FIG. 2) of the axial upper surface 88 with respect to the axial line is set to 60 degrees or more. If the inclination angle β is smaller than 60 degrees, when the thread 62 of the male thread 60 and the thread 92 of the female thread 58 (see FIG. 3) come into contact when the male thread 60 and the female thread 58 are screwed together, the thread 92 of the female thread 58 may be displaced so as to slide toward the outer periphery of the thread 62 of the male thread 60, and the male thread 60 and the female thread 58 may not be screwed together sufficiently. Furthermore, the inclination angle β is set to less than 90 degrees. If the inclination angle β is set to 90 degrees or more, it may be difficult to screw into a standard male connector 56 (for example, as specified in ISO 80369-7 (ISO 594-2)).

In particular, in this embodiment, the inclination angle β at the axial upper surface 88 is larger than the inclination angle α at the axial lower surface 90. As a result, the axial dimension at the axial lower surface 90 is larger than the axial dimension at the axial upper surface 88, and the protruding tip surface 86 provided between the axial upper surface 88 and the axial lower surface 90 is biased toward the upper side of the thread 62. That is, the thread 62 has a shape in which the part with the maximum height dimension is biased toward the upper side. Furthermore, in this embodiment, the axial center (L1 in FIG. 2) of the part with the maximum height dimension in the thread 62 is located above the axial center (L2 in FIG. 2) of the thread 62, and in particular, in this embodiment, the entire part with the maximum height dimension in the thread 62 is located above the axial center of the thread 62.

The maximum height dimension B of the thread 62 (see FIG. 2) is preferably 0.3 mm or more. If the maximum height dimension B is less than 0.3 mm, it may be difficult to ensure sufficient engagement between the male thread 60 and the female thread 58. On the other hand, the maximum height dimension B is preferably 1.5 mm or less. If the maximum height dimension B is more than 1.5 mm, it may be difficult to ensure the thickness dimension of the small diameter tube portion 44, taking into account the screwing with the female thread 58 of a general male connector 56 that complies with the ISO standard.

Furthermore, in this embodiment, in the axial cross section shown in FIG. 2, the width dimension C of the protruding tip surface 86 of the thread 62, which is based on a trapezoidal thread, is set smaller than that of the conventional structure (dash line in FIG. 2). It is preferable that the width dimension C of this protruding tip surface 86 is 0.3 mm or more. If the width dimension C of the protruding tip surface 86 is smaller than 0.3 mm, it becomes difficult to sufficiently secure the height of the thread 62 under the conditions of the inclination angles β and α at the above-mentioned axial upper and lower surfaces 88 and 90, and it may be difficult to obtain sufficient screw fixing force by the engagement of the male thread 60 and the female thread 58. On the other hand, it is preferable that the width dimension C of the protruding tip surface 86 is 1.2 mm or less. If the width dimension C of the protruding tip surface 86 is larger than 1.2 mm, it may be difficult to form a male thread 60 suitable for connection with a general male connector according to ISO standards, etc.

As shown in Figure 3, the needleless connector 10 shaped as described above is connected to the male connector 56 by inserting the male lure of the male connector 56 into the slit 68 of the elastic valve body 14 and screwing the male thread 60 into the female thread 58. Note that in Figure 3, the male connector 56 is shown by a two-dot chain line, and the male lure portion is not shown.

In the conventional needleless connector (shown by the dashed line in FIG. 3), when the male thread and the female thread 58 are screwed together, the threads of the male thread and the threads 92 of the female thread 58 come into contact with each other and mesh at the portion where the dashed line and the two-dot dashed line overlap. Since the abutment surface of the male and female threads is greatly inclined with respect to the central axis, when the male connector 56 is strongly screwed and a large torque is applied, the axial force converted by the screw mechanism is directly applied from the male thread 60 to the small diameter cylindrical portion 44. As a result, stress is concentrated in the thin-walled portion 64 of the small diameter cylindrical portion 44, which is thinner than the male thread 60, and axial elongation deformation is likely to occur. When axial elongation deformation occurs in the thin-walled portion 64, the tensile yield point is already exceeded, so that even if the male connector 56 is further tightened, not only is the tightening fixing force for the needleless connector 10 reduced and difficult to secure, but there is also a risk of a gap occurring at the meshing surface of the male and female threads, causing fluid leakage.

In contrast, in this embodiment, the inclination angle α of the axial underside 90 of the thread 62 of the male thread 60 is set small, so that when a large tightening force is applied when the male thread 60 and the female thread 58 are screwed together, the thread 92 of the female thread 58 easily rides up on the axial underside 90 of the thread 62. In this way, the thread 92 of the female thread 58 rides up on the axial underside 90 of the thread 62, so that the axial tensile force applied to the small diameter cylindrical portion 44 by the screwing of the female thread 58 and the male thread 60 can be prevented from becoming excessive, and the small diameter cylindrical portion 44 can be prevented from stretching. In addition, since the small diameter cylindrical portion 44 does not reach the tensile yield point, the screw fixing force of the male connector 56 to the needleless connector by the screwing of the female and male threads 58, 60 can be effectively maintained.

In particular, in this embodiment, in the axial cross section shown in FIG. 2, the axial upper and lower surfaces 88, 90 of the thread 62 are inclined surfaces that are inclined with respect to the axial direction, and the inclination angle α of the axial lower surface 90 is smaller than the inclination angle β of the axial upper surface 88. As a result, the part of the thread 62 with the largest height dimension is biased toward the upper side of the thread 62, and in this embodiment, the entire part of the thread 62 with the largest height dimension is located above the axial center of the thread 62. As a result, the thread 92 of the female thread 58 is easily allowed to ride up the axial lower surface 90 of the male thread 60, and the thread 92 riding up the axial lower surface 90 reduces the amount of engagement between the two threads 62, 92, i.e., the axial tensile force applied to the small diameter cylindrical portion 44 is reduced, so that the small diameter cylindrical portion 44 can be prevented from elongating.

In addition, the axial upper surface 88 of the thread 62 is an inclined surface that is inclined relative to the axial direction, and by appropriately setting the inclination angle of the axial upper surface 88, it is possible to guide the movement of the thread 92 of the female thread 58 that abuts against the thread 62 of the male thread 60.

The inventors produced a prototype of the needleless connector 10 of this embodiment as an example, and confirmed that the stretching of the housing 16 (small diameter cylindrical portion 44) was prevented. The results are shown in FIG. 4. As a comparative example, the needleless connector described in the above-mentioned Patent Document 1 was used. In both the example and the comparative example, an "Otsuka 20 mL Saline Injection Syringe" manufactured by Otsuka Pharmaceutical Factory, Inc. was used as the male connector 56 to be inserted into the elastic valve body 14, and the torque applied to the male connector 56 and the stretching of the housing 16 (small diameter cylindrical portion 44) were measured when the male thread 60 was deformed and the female thread 58 was screwed in until it began to spin freely.

As shown in Figure 4, in the embodiment, the torque required for the female thread 58 to spin freely is increased compared to the comparative example, and the maximum extension distance of the housing is also reduced.

Next, FIG. 5 shows a needleless connector 100 as a second embodiment of the present invention. In this embodiment, the shape of the thread 104 of the male screw 102 is different from that of the needleless connector described in Patent Document 1 as a conventional structure.

In addition, the members and parts that are substantially the same as those in the first embodiment are given the same reference numerals in the drawings, and detailed description will be omitted. Also, in the needleless connector 100 of this embodiment, the material of the outer retaining portion 22 on which the male thread 102 is formed can be various synthetic resins, such as polypropylene, polyvinyl chloride, polycarbonate, polyacetal resin (POM), etc.

The thread 104 of the male screw 102 in this embodiment has a smaller height dimension than that of the conventional structure, and the maximum height dimension B' of the thread 104 (see Figure 5) is set within the range of 0.3 to 1.5 mm.

If the maximum height dimension B' is less than 0.3 mm, it may be difficult to obtain sufficient fastening force of the screw structure, for example, because the female thread overcomes the male thread 102 when fastening the male connector 56. On the other hand, if the maximum height dimension B' is greater than 1.5 mm, it may be difficult to suppress deformation, such as elongation, of the small diameter tube portion 44 on which the male thread 102 is formed in the needleless connector 100 when a large screw fastening force is applied when connecting the male connector 56, which will be described later.

In addition, in this embodiment, the inclination angle α' (see FIG. 5) of the axial lower surface 90 of the thread 104 of the male thread 102 with respect to the axial direction is set smaller than that of the conventional structure, and is smaller than the inclination angle β of the axial upper surface 88 with respect to the axial direction. As a result, in this embodiment as well, the width dimension C' (see FIG. 5) of the protruding tip surface 86 of the thread 104 is smaller than that of the conventional structure, and the thread 104 has a shape in which the part with the maximum height dimension is biased upward. That is, in the thread 104, the axial center (L1) of the part with the maximum height dimension is located above the axial center (L2) of the thread 104.

In the needleless connector 100 of this embodiment having the above-mentioned shape, when a tightening torque is applied to the male connector 56 during a connecting operation of a male connector that is generally assumed, a screw fixing force is exerted by the engagement of the male thread 102 and the female thread 58. On the other hand, since the thread 104 of the male thread 102 is biased upward and the maximum height dimension B' of the thread 104 is made small, when a tightening torque larger than expected is applied to the male connector 56, the thread 92 of the female thread 58 easily rides up on the thread 104 of the male thread 102. In this way, by the thread 104 of the female thread 58 riding up on the thread 104, it is possible to prevent the axial tensile force applied to the small diameter tube portion 44 by the screwing of the female and male threads 58, 102 from becoming excessive. Therefore, as in the first embodiment, the small diameter cylindrical portion 44 is prevented from stretching, and the small diameter cylindrical portion 44 does not reach its tensile yield point, so that the screw fixing force of the male connector 56 to the needleless connector 100 by the screwing of the female and male threads 58, 102 can be effectively maintained.

Although the embodiments of the present invention have been described above, the present invention should not be interpreted as being limited to the specific descriptions in these embodiments, and can be implemented in various forms with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art.

For example, the shape of the male connector inserted into the needleless connector is not limited as long as it has a female thread that screws into the male thread of the needleless connector, and is not limited to that specified in ISO 80369-7 (ISO 594-2). The male thread provided in the needleless connector is also not limited to the trapezoidal thread structure according to ISO 80369-7 (ISO 594-2). For example, sawtooth threads and triangular threads can also be used. Preferably, the thread structure satisfies the functions specified in ISO 80369 (ISO 594), but the shapes of the male and female threads are not limited, and the meshing ratio and meshing width of the male and female threads can be set appropriately taking into account the material, thread length, etc.

The small diameter cylindrical portion 44 may have a tapered cylindrical outer peripheral surface shape as in the embodiment, or may have a straight cylindrical outer peripheral surface shape without inclination. Furthermore, the male thread 60 formed on the small diameter cylindrical portion 44 is not limited to a multiple thread structure, and may have a single thread structure.

As in the second embodiment, the aspect in which the inclination angle of the axial underside of the male screw thread with respect to the axial direction is made smaller than in the conventional structure and the aspect in which the maximum height dimension of the male screw thread is made smaller than in the conventional structure may be combined and adopted. By adopting these in combination, it is also possible to make the inclination angle of the axial underside of the thread with respect to the axial direction larger than in the first embodiment. This can improve the connection strength between the needleless connector and the male connector while preventing the housing from stretching.

The inclination angles β, α of the upper and lower axial surfaces 88, 90 of the threads 62, 104 of the male screws 60, 102 are not limited in any way. For example, if the entire part of the threads of the male screw where the height dimension is maximum is located above the axial center of the threads of the male screw, the inclination angle of the lower axial surface may be approximately equal to that of the needleless connector described in Patent Document 1, which has a conventional structure. Also, the inclination angle of the upper axial surface may be, for example, 90 degrees.

In addition, in the above embodiment, the housing 16 is composed of three members: the base member 18, the inner holding portion 20, and the outer holding portion 22. However, for example, the base member and the inner holding portion may be integrally formed, or the entire housing may be integrally formed.

Furthermore, in the above embodiment, the cylindrical support portion 70 of the elastic valve body 14 extends axially inward beyond the annular wall portion 46 of the outer retaining portion 22, but the shape of the elastic valve body is not limited to that described in the above embodiment, and for example, the cylindrical support portion may extend only axially outward beyond the annular wall portion of the outer retaining portion. In addition, if the cylindrical support portion extends axially inward beyond the annular wall portion of the outer retaining portion, it is possible to more advantageously achieve effects such as improving the support force to prevent the elastic valve body from falling out and preventing deformation of the female connecting portion (outer retaining portion) when the male connector is screwed into place. However, the male thread provided in the needleless connector is not limited to a form in which it is provided over the entire axial length of the small diameter cylindrical portion of the outer retaining portion, and may be provided partially in the axial direction of the small diameter cylindrical portion of the outer retaining portion.

In the above embodiment, the base portion (base member 18) of the needleless connector 10 is plug-shaped with a male connecting portion (central cylindrical portion 24), but this is not limited to this, and by appropriately changing the shape and structure of the housing, the needleless connector can be structured to be attached to, for example, a three-way stopcock, a mixing tube, or a bag in which a medicinal solution is sealed.
Furthermore, the present invention originally includes each of the inventions described in (i) to (iv) below, and the configurations and effects thereof will be described below.
The present invention relates to
(i) A needleless connector in which a cylindrical support portion extending axially inward in a disk-shaped elastic valve body is attached by being sandwiched in the thickness direction between an outer retaining portion and an inner retaining portion which constitute a cylindrical opening portion, and a male thread is provided on the outer peripheral surface of the outer retaining portion, and a luer lock type male connector can be connected by being screwed onto the male thread, wherein the axial underside of the thread of the male thread is inclined at an angle within the range of 15 degrees to 40 degrees with respect to the central axis of the opening portion;
(ii) A needleless connector in which a cylindrical support portion extending axially inward in a disk-shaped elastic valve body is sandwiched and attached in the thickness direction between an outer retaining portion and an inner retaining portion which form a cylindrical opening portion, and a male thread is provided on the outer peripheral surface of the outer retaining portion, and a luer lock type male connector can be screwed onto the male thread to be connected, wherein the entire part of the thread of the male thread which has the maximum height dimension is located above the axial center of the thread of the male thread;
(iii) A needleless connector in which a cylindrical support portion extending axially inward in a disk-shaped elastic valve body is sandwiched and attached in the thickness direction between an outer retaining portion and an inner retaining portion that form a cylindrical opening portion, and a male thread is provided on the outer peripheral surface of the outer retaining portion, and a luer lock type male connector can be screwed onto the male thread to be connected, wherein the upper and lower axial surfaces of the thread of the male thread are both inclined surfaces that incline in a direction approaching the other side as they approach the outer periphery, and the thread of the male thread is shaped to be biased upward;
(iv) The needleless connector according to any one of claims 1 to 3, wherein a thickness dimension of a cylindrical wall of the outer holding part on which the male thread is formed is 2.0 mm or less.
This includes inventions relating to.
In the invention described in (i) above, the inclination angle of the axial lower surface of the thread of the male screw formed on the outer holding part at the opening portion is set smaller (more gradual) than that of the needleless connector of the conventional structure. When the male connector is fastened with a large force, the female screw formed on the male connector is likely to ride up onto the thread of the male screw formed on the outer holding part before the cylindrical wall of the outer holding part reaches the yield point (tensile yield stress) due to the axial fixing force applied to the opening portion by the female and male screw. Therefore, even if the male connector is fastened with a large force, the cylindrical wall of the outer holding part is prevented from suddenly undergoing large deformation such as elongation, and an effective fastening state can be maintained. As a result, when the male connector is screwed into the opening portion of the needleless connector, the allowable range of the fastening force and fastening amount of the female and male screw required to obtain an appropriate screw fixing force is increased, making it possible to easily and reliably connect the male connector to the needleless connector.
In the invention described in (ii) above, the protruding height of the thread of the male screw is smaller below the axial center than at the maximum portion, so that the thread of the female screw can easily ride up onto the axial underside of the thread of the male screw when the female screw and the male screw are screwed together. Therefore, even if the female screw and the male screw are tightened excessively, the upward force applied from the female screw to the male screw is kept small, and the cylindrical wall of the outer holding part can be prevented from stretching.
In the invention described in (iii) above, the inclination angle of the axial lower surface with respect to the central axis is made smaller than the inclination angle of the axial upper surface of the male thread with respect to the central axis, so that when the male connector is fastened with a large force, the female thread is easily able to ride up onto the axial lower surface of the male thread. Therefore, deformation such as elongation of the cylindrical wall of the outer holding part of the needleless connector can be prevented. In addition, since the axial upper surface of the male thread is inclined downward toward the outer periphery, the axial upper surface can guide the movement of the female thread.
In the invention described in (iv) above, in the needleless connector of this embodiment, the cylindrical wall of the outer retaining part can be designed to be thin while ensuring the screw fixing force of the luer lock, thereby preventing the outer diameter dimension of the needleless connector from becoming too large.

10 needleless connector 12 opening 14 elastic valve body 16 housing 18 base member 20 inner retaining portion 22 outer retaining portion 24 central cylindrical portion 26 peripheral wall portion 28 upper bottom wall portion 30 female thread 32 support wall portion 34 fixing groove 36 annular base end portion 38 receiving seat portion 40 inner engaging claw 42 large diameter cylindrical portion 44 small diameter cylindrical portion 46 annular wall portion 48 fitting groove 50 tip wall portion 52 outer engaging claw 54 outer retaining groove 56 male connector 58 female thread 60 male thread 62 thread 64 thin wall portion 66 central portion 68 slit 70 cylindrical support portion 72 annular connecting portion 74 outer annular groove 76 inner annular groove 78 concave groove portion 80 upper support portion 82 lower support portion 84 flange-shaped portion 86 protruding tip surface 88 axial upper surface 90 axial lower surface 92 Thread 100 Needleless connector 102 Male thread 104 Thread

Claims (4)

A needleless connector in which a cylindrical support portion extending axially inward in a disk-shaped elastic valve body is sandwiched in the thickness direction between an outer retaining portion and an inner retaining portion which define a cylindrical opening portion, and a male thread is provided on the outer peripheral surface of the outer retaining portion, and a luer lock type male connector can be screwed onto the male thread to be connected,
A needleless connector, wherein the axial underside of the thread of the male screw is inclined at an angle within the range of 15 degrees to 40 degrees with respect to the central axis of the opening portion. A needleless connector in which a cylindrical support portion extending axially inward in a disk-shaped elastic valve body is sandwiched in a thickness direction between an outer retaining portion and an inner retaining portion which form a cylindrical opening portion, and a male thread is provided on an outer peripheral surface of the outer retaining portion, and a luer lock type male connector can be screwed into the male thread to be connected,
A needleless connector, in which the entire portion of the thread of the male screw where the height dimension is maximum is located above the axial center of the thread of the male screw. A needleless connector as described in claim 1 or 2 , wherein the upper and lower axial surfaces of the thread of the male screw are both inclined surfaces that incline in a direction approaching the mating surface as they approach the outer periphery, and the thread of the male screw is shaped to be biased upward. The needleless connector according to any one of claims 1 to 3, wherein the thickness dimension of the cylindrical wall of the outer retaining part on which the male thread is formed is 2.0 mm or less.

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