3D needle assembly

Abstract

To provide a needle assembly of a novel structure which can solve a problem in a structure including a connector cap and a needle protector attached to the connector cap.SOLUTION: In a needle assembly 10, a needle tip protector 120 where an inner needle 16 having a needle tip 20 is removably inserted relative to a hollow outer needle 42 for protecting the needle tip 20 of the inner needle 16 by removing the inner needle 16 from the outer needle 42 is connected to a connector cap 102 detachably connected to a base end part of an outer needle hub 44 attached to a base end side of the outer needle 42 in a manner to be separated to a base end side. An inner needle hub 24 attached to a base end side of the inner needle 16 has a guide part 36 radially overlapped with the connector cap 102. Between surfaces where the guide part 36 of the inner needle hub 24 and the connector cap 102 are overlapped, positioning parts 38, 112 for mutually positioning the inner needle hub 24 and the connector cap 102 in an axial direction are provided.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a needle assembly used for blood collection, infusion (including blood transfusion), etc.

Background Art

[0002] Conventionally, a needle assembly has been used for blood collection, infusion, etc. The needle assembly has a structure in which an inner needle having a needle tip is removably inserted into a hollow outer needle, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-199822 (Patent Document 1). After the inner needle and the outer needle are punctured into a blood vessel, the inner needle is removed from the outer needle, so that the hollow outer needle is held in a state of being punctured into the blood vessel, and a blood collection or infusion circuit is connected to the outer needle.

[0003] In addition, in order to prevent accidental puncture of the inner needle after removal, a needle tip protector for protecting the needle tip of the inner needle after removal is provided. The needle tip protector is attached to an outer needle hub provided on the proximal end side of the outer needle via a connector cap. The connector cap is removably connected to the proximal end portion of the outer needle hub by screwing or the like at the tip portion. The needle tip protector is inserted into the proximal end portion of the connector cap and is connected in a state where the needle tip protector is allowed to be detached from the connector cap by pulling it toward the proximal end side. When the inner needle is removed from the outer needle, the needle tip of the inner needle is accommodated in the needle tip protector, thereby preventing accidental puncture (re-puncture) after removal. ;

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Thus, while connector caps are provided to add functionality to the needle assembly, needle assemblies equipped with connector caps have several drawbacks, such as increased axial length, which can lead to several problems during operation. Specifically, for example, when inserting the inner and outer needles, it is preferable for the user to hold the inner needle side during insertion. However, users tend to try to insert the needle from a position closer to the tip, and may end up holding the outer needle side (outer needle hub, etc.) during insertion. However, since the inner needle is designed to be removable by allowing it to move towards the proximal end relative to the outer needle, attempting to insert the needle by holding the outer needle side could cause the inner needle to move towards the proximal end relative to the outer needle due to resistance during insertion, potentially covering the tip of the inner needle with the outer needle.

[0006] Furthermore, some users may bend the inner needle when removing it from the outer needle. However, bending the inner needle during removal can cause it to interfere with the needle tip protector. The force transmitted from the inner needle can cause the needle tip protector to tilt (pull out), potentially unintentionally releasing the connection between the needle tip protector and the connector cap, rendering the needle tip protector ineffective in protecting the inner needle's tip.

[0007] Furthermore, in the structure shown in Figures 7 to 10 of Patent Document 1, the base end of the needle tip protector is inserted into the inner needle hub provided on the base end side of the inner needle. As a result, when the inner needle is removed from the outer needle, the base end of the needle tip protector is exposed to the outside before it can protect the tip of the inner needle, making it possible for the needle tip protector to be touched. Consequently, for example, if a user accidentally pulls the needle tip protector towards the base end side along with the inner needle, the protection of the inner needle tip by the needle tip protector may cease to function.

[0008] The problem to be solved by the present invention is to provide a needle assembly with a novel structure that can solve at least one of the problems related to the needle assembly having the connector cap described above. [Means for solving the problem]

[0009] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0010] In a first embodiment, an inner needle having a needle tip is removably inserted into a hollow outer needle, and a needle tip protector that protects the needle tip of the inner needle when the inner needle is removed from the outer needle is detachably connected to a connector cap that is removably connected to the base end of an outer needle hub attached to the base end of the outer needle, wherein the inner needle hub attached to the base end of the inner needle has a guide portion that overlaps radially with the connector cap, and a positioning portion is provided between the overlapping surfaces of the guide portion of the inner needle hub and the connector cap for positioning the inner needle hub and the connector cap relative to each other in the axial direction.

[0011] According to the needle assembly structured in this embodiment, when the user holds the outer needle side (e.g., outer needle hub, connector cap, etc.) closer to the needle tip and performs a puncture, the positioning of the inner needle hub and connector cap by the positioning part prevents the inner needle from moving towards the proximal end relative to the outer needle due to puncture resistance. Therefore, the tip of the inner needle is not covered by the outer needle, allowing for proper puncture of both the inner and outer needles, and also preventing increased pain during puncture due to a decrease in the sharpness of the needle tip.

[0012] The second embodiment is a needle assembly as described in the first embodiment, wherein the overlapping surfaces of the guide portion and the connector cap are each provided with circumferentially extending protrusions, and these protrusions are locked together in the axial direction to constitute the positioning portion.

[0013] According to the needle assembly structured in this embodiment, the guide portion of the inner needle hub and the connector cap can be easily positioned in the axial direction by locking the protrusions.

[0014] A third embodiment is a needle assembly in which an inner needle having a needle tip is removably inserted into a hollow outer needle, and a needle tip protector that protects the needle tip of the inner needle when the inner needle is removed from the outer needle is detachably connected to a connector cap that is removably connected to the base end of an outer needle hub attached to the base end side of the outer needle, wherein a projection that protrudes axially from one of the needle tip protector and the connector cap is inserted into an insertion cavity provided in the other of the needle tip protector and the connector cap, thereby providing a tilt limiting portion that limits the relative displacement of the needle tip protector and the connector cap in the twisting direction.

[0015] According to the needle assembly structured in this embodiment, for example, when attempting to pull out the inner needle while bending it, the twisting displacement (tilting) of the needle tip protector relative to the connector cap is suppressed by the protruding portion being locked against the inner surface of the insertion cavity, thereby preventing unintended detachment of the needle tip protector from the connector cap.

[0016] A fourth embodiment is the needle assembly described in the third embodiment, wherein the protrusion is cylindrical, and the protrusion and the insertion cavity are provided on either the inner circumference of the needle tip protector or the inner circumference of the connector cap.

[0017] In the needle assembly structure according to this embodiment, any radial twisting displacement is limited by the locking between the protruding portion and the inner surface of the insertion cavity. Furthermore, since the protruding portion and the inner surface of the insertion cavity are locked on both radial sides against twisting input, the twisting displacement of the needle tip protector is effectively suppressed.

[0018] Furthermore, for example, by overlapping the outer circumferential wall of the needle tip protector with the outer circumferential wall of the connector cap to suppress twisting displacement, and by also suppressing twisting displacement by locking the protruding portion with the inner surface of the insertion cavity in the inner circumferential portions of the needle tip protector and connector cap, twisting displacement of the needle tip protector can be effectively prevented by both the inner and outer circumferential portions.

[0019] A fifth aspect is the needle assembly described in the third or fourth aspect, wherein the base end of the needle tip protector is in axial contact with an inner needle hub attached to the base end side of the inner needle.

[0020] According to the needle assembly structured in this embodiment, in the initial state in which the inner needle is inserted into the outer needle, the tilting of the needle tip protector is prevented by contact with the inner needle hub, and the needle tip protector is properly connected to the connector cap.

[0021] The sixth aspect is a needle assembly described in any one of the third to fifth aspects, wherein the needle tip protector has an axial length dimension that is larger than the maximum outer diameter dimension in the direction perpendicular to the axis.

[0022] While axially long needle tip protectors are more susceptible to tilting due to input from, for example, a bent inner needle, the needle assembly structure according to this embodiment prevents the needle tip protector from coming loose from the connector housing due to tilting, even with an axially long needle tip protector, by limiting tilting through the locking of the protruding portion with the inner surface of the insertion cavity.

[0023] The seventh aspect is a needle assembly described in any one of the third to sixth aspects, wherein the base end portion of the connector cap is provided with a locking projection that protrudes inward, the locking projection and the needle tip protector are locked in the axial direction, the connector cap and the needle tip protector are positioned in the axial direction, and the locking projection is located on the outer circumference of the needle tip protector, and the tilting of the needle tip protector relative to the connector cap is limited by the contact between the locking projection and the needle tip protector.

[0024] According to the needle assembly having the structure according to this aspect, the tilting of the needle tip protector with respect to the connector cap can be suppressed by using a locking projection that separably connects the needle tip protector and the connector cap.

[0025] The eighth aspect is the needle assembly according to any one of the third to seventh aspects, wherein the protruding portion protrudes from the needle tip protector toward the distal end side, and the protruding portion is inserted into the inner circumference of the proximal end opening of the outer needle hub.

[0026] According to the needle assembly having the structure according to this aspect, since the protruding portion inserted into the insertion space of the connector cap is also inserted into the proximal end opening of the outer needle hub, the displacement (tilting) of the needle tip protector in the kinking direction can be more effectively suppressed.

[0027] The ninth aspect is a needle assembly in which an inner needle having a needle tip is removably inserted through a hollow outer needle, and a needle tip protector that protects the needle tip of the inner needle when the inner needle is removed from the outer needle is detachably connected to the proximal end portion of an outer needle hub attached to the proximal end side of the outer needle with respect to a connector cap that is removably connected. The connector cap includes a locking projection that protrudes toward the inner circumference, and the needle tip protector inserted into the inner circumference of the connector cap is axially positioned with respect to the connector cap by being locked to the locking projection. The connector cap is provided with a cover portion that extends to the proximal end side of the locking projection and covers the outer circumference of the needle tip protector.

[0028] According to the needle assembly having the structure according to this aspect, since the outer circumference of the needle tip protector is covered by the cover portion of the connector cap, when the inner needle is pulled out from the outer needle, the exposure of the needle tip protector to the outside is prevented. As a result, the risk that the exposed needle tip protector is accidentally pulled toward the proximal end side is reduced, and the needle tip protection by the needle tip protector is appropriately realized.

[0029] The tenth aspect is the needle assembly described in the ninth aspect, wherein the cover portion covers the outer circumference of the needle tip protector over its entire axial length from the tip to the base.

[0030] According to the needle assembly structured in this embodiment, the needle tip protector is covered by the cover portion along its entire axial length, thereby preventing exposure of the outer surface of the needle tip protector when the inner needle is removed, and more effectively preventing malfunctions of the needle tip protection mechanism caused by the user touching the exposed needle tip protector.

[0031] The eleventh embodiment is a needle assembly described in the ninth or tenth embodiment, wherein the inner needle hub provided on the base end side of the inner needle has a covering portion that covers the outer circumference of the cover portion.

[0032] If a cover portion is provided on the connector cap to cover the outer circumference of the needle tip protector, the exposed area of ​​the connector cap increases, making it more likely that the user will grasp the connector cap when removing the needle. However, since the connector cap is a component on the outer needle side, it is desirable that it not be grasped when removing the needle. In a needle assembly structured according to this embodiment, a cover portion that covers the outer circumference of the cover portion is provided on the inner needle hub, making it easier to grasp the inner needle side including the cover portion when removing the needle, thereby guiding the proper execution of puncture.

[0033] Furthermore, it is also possible to adopt an appropriate combination of the first or second embodiment, any one of the third to eighth embodiments, and any one of the ninth to eleventh embodiments. [Effects of the Invention]

[0034] According to the present invention, at least one of the above-mentioned problems can be solved in a needle assembly. [Brief explanation of the drawing]

[0035] [Figure 1] Perspective view showing a needle assembly as a first embodiment of the present invention [Figure 2] Figure 1 shows a longitudinal cross-sectional view of the needle assembly. [Figure 3] Perspective view of the inner needle hub that constitutes the needle assembly shown in Figure 1. [Figure 4] Perspective view of the connector cap that constitutes the needle assembly shown in Figure 1. [Figure 5] Perspective view of the needle tip protector that constitutes the needle assembly shown in Figure 1. [Figure 6] Figure 1 is a magnified vertical cross-sectional view showing the positioning section of the needle assembly. [Figure 7] Figure 1 shows a vertical cross-sectional view of the needle assembly in the state where the inner needle has been pulled out from the outer needle. [Modes for carrying out the invention]

[0036] Embodiments of the present invention will be described below with reference to the drawings.

[0037] Figures 1 and 2 show a needle assembly 10 as a first embodiment of the present invention. The needle assembly 10 has a structure in which an inner needle unit 12 and an outer needle unit 14 are combined. In the following description, as a general rule, the axial direction refers to the left-right direction in Figure 1, with the left side in Figure 1 being the tip side and the right side in Figure 1 being the base side.

[0038] The inner needle unit 12 includes an inner needle 16. The inner needle 16 is a hollow metal needle with a sharp tip 20 formed by a sloping blade surface 18 at its tip. The inner needle 16 has projections (not shown) that protrude radially on both sides of its tip, and the outer diameter of the portion where these projections are formed is larger than that of other parts. The inner needle 16 may also be a solid needle.

[0039] An inner needle hub 24 is provided at the base end of the inner needle 16. As shown in Figures 2 and 3, the inner needle hub 24 has a base portion 26 on which the base end portion of the inner needle 16 is fixed in an inserted state, and a cylindrical connecting portion 28 is provided at the base end of the base portion 26. An inner needle cap 30 is removably inserted and attached to the connecting portion 28. The inner needle cap 30 has a substantially stepped cylindrical shape with a step in the axial middle portion, and a membrane filter 32 that allows the passage of gas and restricts the passage of liquid is provided at the tip portion.

[0040] The inner needle hub 24 is provided with a cover portion 34 that extends from the outer peripheral end of the base portion 26 toward the tip. The cover portion 34 is substantially cylindrical in shape, and the tip portion is slightly larger in diameter to form a fitting cylinder portion 36 that serves as a guide portion to be fitted into the container cap 144, which will be described later. The fitting cylinder portion 36 has a substantially cylindrical inner surface and a polygonal cylindrical outer surface, and in this embodiment the outer surface is octagonal. In this embodiment the fitting cylinder portion 36 is notched so that a part of the circumferential direction opens toward the tip, and the notched portion is positioned in a predetermined orientation in the circumferential direction relative to the cutting surface 18 of the inner needle 16. The inner surface of the fitting cylinder portion 36 is provided with an inner surface projection 38 that protrudes toward the inner circumference. The inner surface projection 38 extends in the circumferential direction for a length of less than half a circumference, and in this embodiment it is provided on both sides in one radial direction.

[0041] The outer needle unit 14 is a cylindrical body having an internal flow path 40 as an internal space that penetrates in the axial direction, and has an outer needle 42 and an outer needle hub 44 connected in communication with the base end side of the outer needle 42.

[0042] The outer needle 42 is a hollow, small-diameter tube made of synthetic resin or the like. The tip of the outer needle 42 has a tapered shape, becoming smaller in diameter towards the tip. The base of the outer needle 42 has an enlarged diameter section 46, which widens towards the base. The base of the outer needle 42 is larger in diameter than the tip of the outer needle 42 due to the presence of the enlarged diameter section 46.

[0043] The outer needle hub 44 is cylindrical overall, and has a structure in which the needle joining member 48 and the flow path connecting member 50 are interconnected by a tube 52.

[0044] The needle joining member 48 is made of a hard synthetic resin. The needle joining member 48 is tapered cylindrical in shape, becoming smaller in diameter towards the tip. The base end portion of the outer needle 42 is inserted into the inner circumference of the needle joining member 48 and fixed in place by means of welding, adhesive, or other means.

[0045] The flow path connecting member 50 is cylindrical in shape overall and includes a valve housing 54. The valve housing 54 is composed of a thin-walled cylindrical outer member 56, a support member 58 arranged on the inner circumference of the outer member 56, and a connecting connector 60 that is inserted and fixed into the base end opening of the outer member 56.

[0046] The outer member 56 has a substantially stepped cylindrical shape, with the base portion having a larger diameter than the tip portion. The base portion of the outer member 56 is provided with a pair of locking holes 62, 62 that penetrate radially. The locking holes 62 are through holes with a substantially rectangular cross-section that correspond to the locking claws 84 of the connection connector 60, which will be described later.

[0047] The support member 58 is generally cylindrical in shape and has a stepped inner surface 64 on its inner circumferential surface that extends in a direction approximately perpendicular to the axis, with the base end being larger in diameter than the tip end of the stepped inner surface 64. In addition, the support member 58 has a ventilation hole 70 that penetrates radially, and the inner circumferential portion of the ventilation hole 70 is groove-shaped, opening into the stepped inner surface 64 and extending therein.

[0048] Furthermore, the tip of the support member 58 is a substantially cylindrical tube insertion portion 72, which opens toward the tip. The support member 58 is provided with a positioning projection 74 that protrudes inward at the base end of the tube insertion portion 72, and the base end surface of the positioning projection 74 is a stepped inner surface 64.

[0049] The support member 58 is positioned on the inner circumference of the outer member 56, thereby forming an annular housing region 76 between the outer member 56 and the support member 58. The housing region 76 is provided on the outer circumference side of the ventilation hole 70 and is in communication with the ventilation hole 70.

[0050] The containment area 76 houses an annular filter 80. The filter 80 allows the passage of gases such as air, but restricts the passage of liquids such as blood. It is sandwiched between the outer member 56 and the support member 58 and is arranged in a compressed state within the containment area 76.

[0051] The connector 60 is generally cylindrical in shape and has a substantially annular threaded portion 82 that protrudes outward at its base end. The connector 60 is insertable into the base end opening of the outer member 56. A pair of locking claws 84, 84 are provided protruding from the outer circumferential surface of the tip portion of the connector 60 that is inserted into the base end opening of the outer member 56, on both the left and right sides. The locking claws 84 have both axial end faces that spread out substantially perpendicular to the axis, and their outer circumferential surfaces are inclined outward toward the base end, with the protruding height being greater on the base end side than on the tip side.

[0052] A plunger 90 is housed on the inner circumference of the connector 60. The plunger 90 is generally cylindrical in shape, with an inner diameter larger than the outer diameter of the inner needle 16. The plunger 90 has an engagement step surface 92 on its outer circumference, midway along the axial direction, with the tip side protruding outward from the engagement step surface 92 compared to the base side. The plunger 90 is inserted into the connector 60, and the engagement step surface 92 of the plunger 90 abuts against the plunger engagement portion 88 of the connector 60 from the tip side, locking it in the axial direction, thereby positioning the plunger 90 in the axial direction relative to the connector 60.

[0053] The connection connector 60 is inserted from the base end into the outer member 56 which houses the support member 58. The locking claws 84, 84 of the connection connector 60 are then inserted into the locking holes 62, 62 of the outer member 56, and the locking claws 84, 84 are locked to the inner surfaces of the locking holes 62, 62 in the axial and circumferential directions, thereby fixing the connection connector 60 to the outer member 56 and forming the valve housing 54.

[0054] The valve housing 54 houses the valve body 94. The valve body 94 is a disc valve with a slit 96 that penetrates axially formed in its central portion, and is made of an elastic rubber or elastomer. The valve body 94 has an annular retaining groove 100 that opens at the base end face and extends circumferentially along the inner circumference of the retaining cylinder portion 98.

[0055] The valve body 94 is inserted into a support member 58 that constitutes the outer needle hub 44. The outer diameter of the valve body 94 is slightly larger than the inner diameter of the portion of the support member 58 that houses the valve body 94, even in its standalone state before insertion into the support member 58. As a result, the valve body 94 is compressed radially when inserted into the support member 58, and is housed in the inner circumference of the support member 58 with the slit 96 closed.

[0056] The valve retaining portion 86 of the connecting connector 60 is inserted into the retaining cylinder portion 98 of the valve body 94, and the tip portion of the valve retaining portion 86 is inserted into the retaining groove portion 100 of the valve body 94. As a result, the outer circumference of the valve body 94 is axially clamped between the stepped inner surface 64 of the support member 58 and the tip surface of the valve retaining portion 86, and the retaining cylinder portion 98 is clamped between the inner circumferential surface of the support member 58 and the outer circumferential surface of the valve retaining portion 86, thereby fixing it to the valve housing 54. The lumen of the valve housing 54 is then blocked by the valve body 94 with its slit 96 closed.

[0057] The needle connector member 48 and the valve housing 54 are interconnected by a tube 52. The tube 52 is a flexible soft tube made of resin elastomer or rubber, which is capable of bending and deformation, and also allows for changes in its cross-sectional shape. The provision of the tube 52 makes it easier to connect external circuits, such as dialysis circuits and infusion circuits, to the external needle hub 44 while the needle connector member 48 is fixed to the skin. The tip of the tube 52 is fixed to the needle connector member 48, and the base end is inserted into the inner circumference of a support member 58 attached to the flow path connecting member 50 and fixed therein. As a result, the needle connector member 48 and the flow path connecting member 50 are connected by the tube 52, and the lumen of the flow path connecting member 50 is in communication with the lumen of the tube 52. The intermediate portion of the tube 52, located between the tip and base ends, is detached from both the needle connector member 48 and the flow path connecting member 50, and is allowed to deform, such as bending or crushing.

[0058] The tip portion of the tube 52 is inserted into and connected to the base portion of the outer needle 42. In this embodiment, the tip portion of the tube 52 is sandwiched and fixed between the base portion of the outer needle 42 and the radially connected needle joint member 48, and the outer needle hub 44, including the needle joint member 48 and the tube 52, is connected to the base end of the outer needle 42. The lumen of the outer needle 42 and the lumen of the outer needle hub 44 are in communication with each other, and the internal flow path 40 of the outer needle unit 14 is configured to include the lumen of the outer needle 42 and the lumen of the outer needle hub 44 and penetrates axially. The tip portion of the tube 52 that is inserted into the needle joint member 48 and fixed to the outer needle 42, and the base portion that is inserted into the tube insertion portion 72 of the support member 58 and fixed to the flow path connecting member 50, have a larger diameter than the intermediate portion located between the needle joint member 48 and the flow path connecting member 50.

[0059] As shown in Figure 2, the inner needle unit 12 and the outer needle unit 14, which are structured in this manner, are combined with each other to form a needle assembly 10 with the inner needle 16 inserted through the outer needle 42 from the base end. The inner needle 16 is inserted through the slit 96 of the valve body 94 and penetrates the valve body 94. Since the inner surface of the slit 96 in the valve body 94 is in close contact with the outer surface of the inner needle 16, even when the inner needle 16 is inserted, the internal space on the tip side of the valve body 94 and the internal space on the base side of the outer needle hub 44 are kept in a non-communicating state, separated by the valve body 94.

[0060] The inner needle unit 12 and the outer needle unit 14 are connected to each other in the axial direction via a connector cap 102. As shown in Figures 2 and 4, the connector cap 102 is generally cylindrical in shape, and has a partition portion 104 that protrudes inward in the middle of the axial direction. The part of the circumferential wall closer to the tip of the partition portion 104 is a locking cylinder portion 106, and the base end is a connecting cylinder portion 108. The locking cylinder portion 106 has a female thread on its inner circumferential surface that screws into the threaded portion 82 of the connecting connector 60, and is connected to the connecting connector 60 in a removable manner. The connecting cylinder portion 108 has a tongue-shaped base end on both radial sides, and each of these tongue-shaped portions has a locking projection 110 that protrudes inward. The locking projection 110 is a ridge shape that extends in the circumferential direction for a length of less than half a circumference, and its axial width gradually decreases towards the protruding tip. Between the circumferentially positioned portions (tongue-shaped portions) of the locking projections 110, 110 at the base end of the connecting cylinder portion 108, external projections 112 are provided as protrusions that project from the outer circumferential surface. The external projections 112 extend in the circumferential direction, and in this embodiment, two external projections 112, 112 are provided in parallel at positions separated from each other in the axial direction.

[0061] An insertion tube portion 114 is provided at the inner circumferential end of the partition portion 104, projecting toward the tip. The insertion tube portion 114 is substantially cylindrical in shape and is inserted into the base end opening of the connection connector 60 when the threaded portion 82 of the connection connector 60 is screwed into the locking tube portion 106. The outer circumferential surface of the insertion tube portion 114 is a tapered surface corresponding to the Luer taper set on the inner circumferential surface of the connection connector 60, and its diameter decreases toward the tip. The outer circumferential surface of the insertion tube portion 114 and the inner circumferential surface of the connection connector 60 may be close to each other but separated when the threaded portion 82 of the connection connector 60 is screwed into the locking tube portion 106, but preferably they are fitted together in contact. The inner circumferential surface of the insertion tube portion 114 is substantially cylindrical in shape and has a substantially constant diameter in the axial direction. Furthermore, the inner diameter of the insertion cylinder portion 114 is larger than the outer diameter of the plunger 90, and the tip of the insertion cylinder portion 114 inserted into the connection connector 60 is positioned in an extrapolated state relative to the base end of the plunger 90. Therefore, the tip of the insertion cylinder portion 114 is inserted radially between the connection connector 60 and the plunger 90.

[0062] The connector cap 102 includes a cover portion 116 that extends further toward the base end from the connecting cylinder portion 108. The cover portion 116 is substantially cylindrical in shape and extends linearly with substantially constant inner and outer diameters. The portion of the connecting cylinder portion 108 where the locking projection 110 is provided is separated from the cover portion 116 by a notch 118. The notch 118 is substantially U-shaped, and the portion where the locking projection 110 is provided is tongue-shaped and independent from both sides in the circumferential direction and the axial base end side (cover portion 116). As a result, the locking projection 110 is allowed to move radially due to the bending of the tongue-shaped portion defined by the notch 118 in the connecting cylinder portion 108.

[0063] A needle tip protector 120 is positioned on the inner circumference of the connector cap 102. As shown in Figure 2, the needle tip protector 120 has a structure in which a shutter member 124 is housed inside the protector housing 122.

[0064] The protector housing 122 has a hollow structure, and as shown in Figure 5, its axial length is larger than the maximum outer diameter in the direction perpendicular to the axis, meaning that the axial length is longer than the radial length. The protector housing 122 includes a housing body 126. The housing body 126 is cylindrical overall, with the tip portion having a larger diameter than the base portion. The base end of the housing body 126 has a base end projection 128 that protrudes inward along its entire circumference, and a ring-shaped regulating plate 130 is superimposed on the base end projection 128 from the tip side. The inner diameter of the regulating plate 130 is such that the inner needle 16 can be inserted through it, but the projection that protrudes from the outer circumferential surface of the tip portion of the inner needle 16 cannot pass through.

[0065] The tip opening of the housing body 126 is covered by a cover member 132. The cover member 132 has a roughly annular plate-shaped cover body 134, and the diameter of the central hole that penetrates the cover body 134 in the axial direction is larger than the maximum outer diameter of the inner needle 16, allowing the projection of the inner needle 16 to pass through. The cover member 132 has a guide wall portion 136 that is inserted into the housing body 126. The guide wall portion 136 is roughly cylindrical in shape, and the diameter of the central hole that penetrates it in the axial direction is larger than the maximum outer diameter of the inner needle 16. The guide wall portion 136 is provided at a position away from the base end of the cover body 134 and is connected to the cover body 134 at multiple points in the circumferential direction.

[0066] The lid body 134 of the protector housing 122 is provided with a projection 138 that protrudes toward the tip. The projection 138 is substantially cylindrical in shape and protrudes axially from the inner circumferential end of the lid body 134 toward the tip. The projection 138 is insertable into the insertion tube portion 114 of the connector cap 102. It is desirable that the axial length of the projection 138 be greater than or equal to the length of the portion that overlaps with the inner circumferential surface of the connecting tube portion 108 of the needle tip protector 120.

[0067] The shutter member 124 is housed in the large-diameter tip portion of the housing body 126 and is positioned axially between the lid body 134 and the guide wall portion 136 of the lid member 132. The shutter member 124 consists of a movable body 140 made of a ferromagnetic material such as iron and a magnet 142 that exerts a magnetic attractive force on the movable body 140. The movable body 140 is preferably roughly disc-shaped and large enough to cover the entire central hole of the lid body 134 and the guide wall portion 136. The magnet 142 is fixed to the protector housing 122 and is positioned above the movable body 140. The movable body 140 is allowed to move vertically relative to the protector housing 122 and is biased upward by the magnetic force of the magnet 142.

[0068] As shown in Figure 2, the needle tip protector 120 is positioned axially on the base side of the connector cap 102 by inserting its large-diameter tip portion into the connecting cylinder portion 108 of the connector cap 102 from the base end side and locking it axially with the locking projections 110, 110 of the connecting cylinder portion 108. The needle tip protector 120 is positioned to detach from the connector cap 102 towards the base end when a tensile force is applied toward the base end side during the removal of the inner needle 16, which will be described later. The needle tip protector 120 is positioned axially on the base side of the connector cap 102 by overlapping its tip surface with the partition portion 104 of the connector cap 102 from the base end side.

[0069] The protruding portion 138 of the needle tip protector 120 is inserted into the insertion cylinder portion 114 of the connector cap 102. The protruding portion 138 may be close to the inner circumferential surface of the insertion cylinder portion 114 but in this embodiment it is fitted into the insertion cylinder portion 114, with the outer circumferential surface of the protruding portion 138 and the inner circumferential surface of the insertion cylinder portion 114 overlapping in contact. The protruding portion 138 fitted into the insertion cylinder portion 114 reaches beyond the base end of the connection connector 60 to the tip side and is inserted into the base end opening of the connection connector 60. When the protruding portion 138 is fitted into the insertion cylinder portion 114, it is located on the base end side of the tip of the insertion cylinder portion 114 and is located on the base end side with respect to the plunger 90. In other words, the insertion tube portion 114 has a longer insertion length into the connection connector 60 than the protruding portion 138, and the insertion tip of the insertion tube portion 114 extends beyond the tip of the protruding portion 138 to the outer circumference of the base end of the plunger 90. Both the tip of the protruding portion 138 and the base end of the plunger 90 are inserted into the insertion tube portion 114, and these protruding portion 138 and plunger 90 are positioned facing each other in the axial direction inside the insertion tube portion 114.

[0070] The tip protector 120 is covered on the outer circumference of its tip portion by the connecting cylinder portion 108 of the connector cap 102, and on the outer circumference of its base portion by the cover portion 116 of the connector cap 102. In this embodiment, the base end of the cover portion 116 reaches the same position as the base end of the tip protector 120 in the axial direction, and the tip protector 120 is covered on its outer circumference by the connector cap 102 along its entire axial length.

[0071] An inner needle 16 is inserted through the needle tip protector 120. The inner needle 16 passes through the base end opening of the housing body 126 and the central hole of the lid body 134 and guide wall portion 136 of the lid member 132, respectively, and the inclination of the needle tip protector 120 with respect to the inner needle 16 is restricted. The inner needle 16 passes between the movable body 140 and the magnet 142, and the movement of the movable body 140 toward the magnet 142 is restricted by the contact of the movable body 140 with the inner needle 16.

[0072] With the inner needle 16 inserted through the outer needle 42, the cover portion 34 of the inner needle hub 24 is fitted onto the cover portion 116 of the connector cap 102. As a result, the outer circumference of the cover portion 116 is covered by the cover portion 34, and the outer surface is concealed by the cover portion 34. In addition, the fitting cylinder portion 36 provided on the tip side of the cover portion 34 is fitted onto the connecting cylinder portion 108 of the connector cap 102 and superimposed on the outer surface of the connecting cylinder portion 108. As a result, as shown in Figure 6, the inner surface projection 38 of the fitting cylinder portion 36 that has overcome the outer surface projection 112 of the connecting cylinder portion 108 is locked to the outer surface projection 112 in the axial direction from the tip side, and the positioning portion that positions the inner needle hub 24 at the axial base end side relative to the connector cap 102 is formed by the locking of the inner surface projection 38 and the outer surface projection 112. The positioning action by the positioning section (locking of the inner protrusion 38 and the outer protrusion 112) is released by pulling the inner needle hub 24 toward the base end relative to the connector cap 102. In short, the locking of the inner protrusion 38 and the outer protrusion 112 positions the inner needle hub 24 in such a manner that it can be detached from the connector cap 102 toward the base end in the axial direction. In this embodiment, the tip-side inner protrusion 38 is inserted between the axial sides of the outer protrusions 112, 112, and the base-side outer protrusion 112 is inserted between the axial sides of the inner protrusions 38, 38.

[0073] The base end surface of the connector cap 102 abuts against the tip surface of the base portion 26 of the inner needle hub 24, positioning the inner needle hub 24 axially towards the tip of the connector cap 102. Furthermore, the base end surface of the needle tip protector 120 abuts against the tip surface of the base portion 26 of the inner needle hub 24 in the axial direction, sandwiching the needle tip protector 120 between the connector cap 102 and the inner needle hub 24 in the axial direction. As a result, the needle tip protector 120 is positioned without being inclined relative to the connector cap 102 and the inner needle hub 24.

[0074] As virtually shown by the dashed line in Figure 2, the needle assembly 10 is fitted with a container cap 144 to prevent the needle tip 20 from being exposed before use. The container cap 144 is made of a hard synthetic resin or the like and has a roughly bottomed cylindrical shape, with the bottom wall covering the tip side of the needle tip 20. The base end of the container cap 144 is fitted onto the fitting cylinder portion 36 of the inner needle hub 24 and is attached with a certain degree of fixing force to prevent unintended detachment from the needle assembly 10. When using the needle assembly 10, the needle assembly 10 can be removed from the container cap 144 by pulling it out from the base end, thereby exposing the needle tip 20. Alternatively, a container base 146 may be provided that is detachably connected to the base end of the container cap 144 and covers the base portion of the needle assembly 10, thereby allowing the entire needle assembly 10 to be housed in a hollow container 148. Furthermore, for example, by sealing the connection between the container cap 144 and the container base 146 with adhesive tape or the like, it becomes possible to detect whether the container 148 has been opened, and to easily confirm whether the needle assembly 10 is unused.

[0075] The needle assembly 10, with this structure, is used when inserting and implanting the external needle unit 14 into a patient's blood vessel. Specifically, first, a user such as a physician inserts the inner needle 16 and outer needle 42 of the needle assembly 10, which has been removed from the container cap 144, into the patient's blood vessel. The insertion of the inner needle 16 and outer needle 42 into the blood vessel can be confirmed by the inflow of blood (backflow) to the inner needle 16 side and / or the outer needle 42 side. Since the air inside the outer needle hub 44 is discharged to the outside space through the vent hole 70 when blood flows in, the inflow of blood is not easily obstructed by air. In addition, since the leakage of blood to the outside space through the vent hole 70 is prevented by the filter 80, blood leakage is prevented when the tip side of the valve body 94 in the internal flow path 40 of the outer needle hub 44 is filled with blood. Similar to the outer needle hub 44, when blood flows into the inner needle hub 24, the air filling the inside is discharged to the outside space through the membrane filter 32, and the leakage of blood into the outside space is prevented by the membrane filter 32.

[0076] When inserting the inner needle 16 and outer needle 42, it is preferable for the user to hold the inner needle hub 24, which is on the inner needle 16 side, while performing the insertion. However, the user may also perform the insertion while holding the outer needle hub 44, which is located closer to the needle tip 20 than the inner needle hub 24. In this embodiment, the inner surface projection 38 of the inner needle hub 24 is axially locked to the outer surface projection 112 of the connector cap 102, which is fixedly connected to the outer needle hub 44 side. As a result, resistance (positioning effect) is exerted by the locking of the inner surface projection 38 and the outer surface projection 112 against the movement of the inner needle 16 toward the proximal end of the outer needle 42, thereby restricting the movement of the inner needle 16 toward the proximal end of the outer needle 42. Therefore, even if the user performs the insertion while holding the outer needle 42 side, the insertion resistance acting on the inner needle 16 (resistance when penetrating body tissue such as skin) can prevent the inner needle 16 from moving toward the proximal end of the outer needle 42. Therefore, problems such as the blade surface 18 of the inner needle 16 being covered by the outer needle 42, which would make the intended puncture impossible, or increased resistance during puncture leading to increased pain for the patient, can be prevented.

[0077] Furthermore, in this embodiment, the tip portion of the inner needle hub 24 is a cover portion 34 and a fitting cylinder portion 36 that overlap the outer circumferential surface of the connector cap 102, and extends towards the tip side closer to the needle tip 20 than the base portion 26. Therefore, the user can hold the inner needle 16 side at a position closer to the needle tip 20, making the puncture operation easier while avoiding problems such as the inner needle 16 moving toward the proximal end relative to the outer needle 42 due to puncture resistance. In particular, in this embodiment, the axial dimension of the connector cap 102 is increased by the presence of a cover portion 116, but since the outer circumferential surface of the cover portion 116 is covered by the cover portion 34, the exposed area of ​​the outer circumferential surface of the connector cap 102 is reduced, making it difficult for the user to grasp the connector cap 102 during puncture. Therefore, the disconnection of the connection between the connecting connector 60 and the connector cap 102 due to the user accidentally twisting the connector cap 102 is prevented.

[0078] Next, the user pulls the inner needle unit 12 out of the outer needle unit 14 towards the proximal end while preventing the outer needle 42 from coming out of the blood vessel (see Figure 7). As described above, the inner needle unit 12 is positioned axially relative to the outer needle unit 14 by the locking of the inner projection 38 of the inner needle hub 24 and the outer projection 112 of the connector cap 102, but when the user pulls the inner needle unit 12 towards the proximal end relative to the outer needle unit 14, the locking of the inner projection 38 and the outer projection 112 is easily released.

[0079] As the inner needle unit 12 moves toward the base end relative to the outer needle unit 14, the cover portion 34 moves toward the base end, as shown in Figure 7. However, since the outer circumference of the needle tip protector 120 is covered by the cover portion 116 of the connector cap 102, exposure to the outside when the inner needle unit 12 is pulled out is limited. In particular, in this embodiment, the cover portion 116 reaches the base end of the needle tip protector 120, preventing exposure of the outer circumference of the needle tip protector 120. As a result, when pulling out the inner needle unit 12, it is difficult for the user to touch the needle tip protector 120, and the detachment of the needle tip protector 120 from the connector cap 102 caused by the user accidentally moving the needle tip protector 120 toward the base end is prevented. This ensures stable protection of the needle tip 20 of the inner needle 16 by the needle tip protector 120, as described later.

[0080] When the inner needle unit 12 is pulled out from the outer needle unit 14 toward the base end, the user may apply a force that bends the inner needle 16. In this case, the bent inner needle 16 interferes with the base end of the needle tip protector 120, and a twisting force acts on the needle tip protector 120. As a result, the tip portion of the needle tip protector 120, which is locked to the connector cap 102, can easily overcome the locking projection 110, making it easier for the needle tip protector 120 to detach from the connector cap 102 toward the base end. In this embodiment, as shown in Figure 2, the projection 138 provided on the tip portion of the needle tip protector 120 is inserted into the insertion cavity formed by the lumen of the insertion cylinder portion 114 of the connector cap 102, and the outer circumferential surface of the projection 138 is superimposed on the inner surface of the wall of the insertion cavity (the inner circumferential surface of the insertion cylinder portion 114). Furthermore, the contact between the protruding portion 138 and the insertion cylinder portion 114 constitutes a tilt limiting portion that limits the relative amount of twisting displacement of the needle tip protector 120 with respect to the connector cap 102, thereby suppressing the relative displacement (tilting) of the needle tip protector 120 in the twisting direction with respect to the connector cap 102. Therefore, even if, for example, the user pulls out the inner needle 16 while bending it, it is unlikely that the needle tip protector 120 will come off the connector cap 102 due to twisting displacement, and as will be described later, the needle tip 20 of the inner needle 16 is effectively protected by the needle tip protector 120. Note that the twisting direction is the direction in which the central axis of the needle tip protector 120 is tilted relative to the central axis of the connector cap 102, and the relative displacement of the needle tip protector 120 in the twisting direction with respect to the connector cap 102 means that the central axis of the needle tip protector 120 is displaced so as to be tilted relative to the central axis of the connector cap 102.

[0081] In this embodiment, since the cylindrical projection 138 is inserted into the cylindrical insertion tube portion 114 to form a tilt limiting portion, the twisting displacement of the needle tip protector 120 relative to the connector cap 102 is limited by the locking of the projection 138 and the insertion tube portion 114, regardless of the radial direction in which the twisting force acts on the needle tip protector 120.

[0082] Furthermore, locking projections 110, 110 of the connector cap 102 are positioned on the vertically outward side of the needle tip protector 120. As a result, the relative displacement of the needle tip protector 120 with respect to the connector cap 102 in the vertical twisting direction is also limited by contact with the locking projections 110, 110 of the needle tip protector 120. In short, in this embodiment, the needle tip protector 120 and the connector cap 102 are positioned in the axial direction and also in the twisting direction by the locking projections 110, 110.

[0083] The twisting displacement of the needle tip protector 120 relative to the connector cap 102 is limited in the outer circumference by the engagement between the outer circumferential surface of the tip portion of the protector housing 122 and the inner circumferential surface and locking projections 110, 110 of the connecting cylinder portion 108 of the connector cap 102, and in the inner circumference by the engagement between the protruding portion 138 and the insertion cylinder portion 114. In this way, the relative twisting displacement of the needle tip protector 120 relative to the connector cap 102 is effectively suppressed by restrictions on both the inner and outer circumference sides.

[0084] In this embodiment, the tip portion of the protrusion 138 inserted into the insertion cylinder portion 114 is also inserted into the base end opening of the outer needle hub 44. Therefore, the twisting displacement of the needle tip protector 120 is more effectively suppressed. In this embodiment, the base end of the connection connector 60 protrudes further than the plunger 90, and the tilt limiting portion is efficiently provided by making good use of the space on the base end side of the plunger 90 in the internal space of the connection connector 60. Furthermore, the base end of the connection connector 60 into which the insertion cylinder portion 114 and the protrusion 138 are inserted has a threaded portion 82 protruding from its outer circumferential surface, which gives it high deformation rigidity and suppresses deformation against twisting input, so that the tilt limiting function of the tilt limiting portion can be efficiently realized.

[0085] The needle tip protector 120 of this embodiment has an elongated shape that is long in the axial direction. Therefore, when a twisting force is applied to the base end portion due to contact with the inner needle 16 or the like while the tip portion is connected to the connector cap 102, the tip portion is likely to come off the connector cap 102 due to the twisting displacement. However, by having the twisting displacement suppression structure described above, even the axially long needle tip protector 120 can be prevented from coming off the connector cap 102 unintentionally due to twisting input.

[0086] When the inner needle unit 12 is moved towards the proximal end relative to the outer needle unit 14, the needle tip 20 of the inner needle 16 is housed inside the needle tip protector 120, as shown in Figure 7. As the inner needle 16 moves towards the proximal end relative to the movable body 140 of the needle tip protector 120, the contact between the movable body 140 and the inner needle 16 is released, and the movable body 140 is attracted and moved toward the magnet 142 by the magnetic force of the magnet 142. As a result, the central hole of the lid body 134 and the guide wall portion 136 is covered by the movable body 140, and the movement of the inner needle 16 toward the tip is prevented by the contact of the needle tip 20 with the movable body 140. Therefore, the inner needle 16, after being removed from the outer needle 42, is protected by the needle tip protector 120 without its needle tip 20 being exposed to the outside, and it is possible to prevent the inner needle 16, which has been removed after puncture, from being accidentally re-punctured.

[0087] When the needle tip 20 moves the inner needle 16, which is housed in the needle tip protector 120, further toward the base end, the projection provided on the tip portion of the inner needle 16 is axially locked to the regulating plate 130 superimposed on the base end of the needle tip protector 120. Then, when the inner needle 16 is moved further toward the base end with the projection and the regulating plate 130 locked together, a force acting toward the base end is applied to the needle tip protector 120, causing the needle tip protector 120 to push open the locking projections 110, 110 of the connector cap 102 and detach from the connector cap 102 toward the base end. As a result, the inner needle unit 12, with the tip portion of the inner needle 16 covered by the needle tip protector 120, separates from the outer needle unit 14, to which the connector cap 102 is connected.

[0088] In this embodiment, the locking projections 110, 110 on the connector cap 102 are formed into tongue-shaped notches 118, 118. As a result, when the needle tip protector 120 is pulled out of the connector cap 102, the tongue-shaped notches flex and deform, making it easier for the needle tip protector 120 to push open the space between the opposing locking projections 110, 110. Therefore, the needle tip protector 120 is not excessively positioned by the locking projections 110, 110, and the needle tip protector 120 can be separated from the connector cap 102 towards the base end as needed. In short, because the locking projections 110, 110 on the connector cap 102 are formed into tongue-shaped notches 118, 118, the ease with which the needle tip protector 120 can be pulled out of the connector cap 102, in other words, the positioning force, can be appropriately adjusted and set. In addition, when the mold that forms the inner circumferential surface of the connecting cylinder portion 108 and the cover portion 116 is removed axially during the molding of the connector cap 102, the locking projections 110, 110 protruding from the inner circumferential surface will have an undercut structure for demolding the mold. However, since the locking projections 110, 110 are allowed to move toward the outer circumference by the notches 118, 118, demolding is made easier.

[0089] The external needle unit 14, which is placed in a punctured blood vessel of the patient, is used as an indwelling needle for infusion, medication administration, blood sampling, etc., by removing the connector cap 102 from the proximal end of the connecting connector 60 and then connecting an external circuit, such as a syringe or infusion line (not shown), to the proximal end of the connecting connector 60. When the external circuit is connected, the plunger 90 is pushed toward the tip, and the slit 96 of the valve body 94 is expanded by the plunger 90, thereby releasing the blockage of the lumen of the external needle hub 44 by the valve body 94 and switching the lumen of the external needle hub 44 to a state of communication. The valve body 94, with its slit 96 expanded by the plunger 90, may be positioned to close the inner circumferential opening of the vent hole 70, thereby more effectively preventing leakage of blood, etc., through the vent hole 70.

[0090] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, in the above embodiment, a structure in which the outer needle hub 44 has a tube 52 in the middle of the axial direction was illustrated, but the tube 52 is not essential, and the entire outer needle hub 44 may be fixed to the outer needle 42 without deformation or displacement.

[0091] The positioning mechanism is not limited to the locking of the inner surface protrusions 38 and the outer surface protrusions 112. For example, the positioning mechanism can also be configured by roughening the overlapping surfaces of the guide portion (fitting cylinder portion 36) of the inner needle hub 24 and the connector cap 102, thereby increasing the sliding resistance between the overlapping surfaces of the guide portion 36 and the connector cap 102. Alternatively, the positioning mechanism can be configured by providing spot-like irregularities on the overlapping surfaces of the guide portion 36 and the connector cap 102, and the fitting of these irregularities. The inner surface protrusions 38 and the outer surface protrusions 112 may be provided partially in the circumferential direction or over the entire circumference in the circumferential direction.

[0092] The cover portion 34 of the inner needle hub 24 does not need to cover only the outer circumference of the cover portion 116; for example, it can be provided to cover the outer circumference of the entire axial length of the connector cap 102. In this case, if the tip portion of the cover portion 34 is provided with an inner projection 38 as a fitting cylinder portion 36, then for example, the cover portion 34 may protrude further than the tip of the connector cap 102, and an outer projection 112 may be provided on the outer circumference of the tip portion (lock cylinder portion 106) of the connector cap 102, or the inner projection 38 may be locked onto the tip surface of the connector cap 102.

[0093] Alternatively, the cover portion 34 of the inner needle hub 24 may be omitted, and the outer peripheral surface of the cover portion 116 of the connector cap 102 may be exposed to the outside.

[0094] The cover portion 116 of the connector cap 102 does not necessarily have to reach the base end of the needle tip protector 120, and the base end of the needle tip protector 120 may protrude further than the cover portion 116. In this case, it is desirable that the length of the needle tip protector 120 protruding further than the cover portion 116 is 5 mm or less, and more preferably 3 mm or less, to prevent the user from accidentally gripping it.

[0095] The protrusion 138 does not necessarily have to be provided on the inner circumference of the needle tip protector 120; for example, it may be provided on the outer circumference. Furthermore, the protrusion 138 is not limited to a cylindrical shape; it may be axial or projection-shaped, in which case the protrusion can be provided at a part or multiple locations in the circumferential direction. In the above embodiment, an example was shown in which the protrusion 138 protruding axially toward the tip side is provided on the needle tip protector 120 and the insertion cavity is provided on the connector cap 102. However, the protrusion may be provided protruding axially toward the base end side from the connector cap 102, and the insertion cavity may be provided on the needle tip protector 120.

[0096] In the above embodiment, an example of a needle assembly 10 was shown in which (1) a cover portion 116 of the connector cap 102, (2) an inner surface projection 38 of the inner needle hub 24 and an outer surface projection 112 of the connector cap 102, and (3) a projection 138 of the needle tip protector 120 and an insertion cavity of the connector cap 102 are all provided. However, it is not necessary for all of (1) to (3) to be provided. [Explanation of symbols]

[0097] 10 needle assembly 12. Inner needle unit 14. Outer needle unit 16 Inner Hand 18 Blade surface 20 needle tip 24 Inner needle hub 26 Base 28 Connecting part 30 Inner needle cap 32. Film-type filters 34 Covering part 36 Fitting cylinder section (guide section) 38. Internal protrusions (positioning section, protrusions) 40 Internal flow path 42 Outer needle 44 Outer needle hub 46 Expanded diameter part 48 Needle joint member 50 Flow channel connection member 52 tubes 54 Valve Housing 56 Outer member 58 Support member 60 connection connectors 62 Locking holes 64 Stepped inner surface 70 ventilation holes 72 Tube insertion section 74 Positioning projection 76 Containment Area 80 filters 82 Threaded part 84 Locking claws 86 Valve retaining part 88 Pusher engagement part 90 pusher 92 Engaging step surface 94 Valve body 96 Slits 98 Holding cylinder part 100 Retaining groove 102 Connector Cap 104 Partition 106 Locking cylinder section 108 Connecting cylinder section 110 Locking projection 112 External protrusions (positioning part, protrusions) 114 Insertion tube section (tilting limiting section) 116 Cover section 118 Notches 120 Needle Tip Protector 122 Protector Housing 124 Shutter component 126 Housing body 128 Proximal protrusion 130 Regulation Plate 132 Lid member 134 Lid body 136 Guide wall section 138 Protruding part (tilting limiting part) 140 Movable body 142 Magnets 144 Container Caps 146 Container Base 148 containers

Claims

1. In a needle assembly in which an inner needle having a needle tip is removably inserted into a hollow outer needle, and a needle tip protector that protects the needle tip of the inner needle when the inner needle is removed from the outer needle is axially positioned via a radially flexible piece to a connector cap that is removably connected to the base end of an outer needle hub attached to the base end side of the outer needle, and is detachably connected from the positioning state toward the base end side of the connector cap, The needle tip protector does not have a member that biases it toward the needle tip side of the inner needle, and the needle tip protector is assembled to be movable in the axial direction relative to the inner needle. The inner needle hub attached to the base end of the inner needle is provided with a guide portion that is superimposed radially on the connector cap, Between the overlapping surfaces of the guide portion of the inner needle hub and the connector cap, a positioning portion is provided for axially positioning the inner needle hub and the connector cap relative to each other. A needle assembly in which the movement of the inner needle toward the base end relative to the outer needle is restricted by the positioning part.

2. The needle assembly according to claim 1, wherein the overlapping surfaces of the guide portion and the connector cap are each provided with circumferentially extending protrusions, and these protrusions are locked together in the axial direction to constitute the positioning portion.

3. The needle assembly according to claim 1 or 2, wherein a projection that protrudes axially from one of the needle tip protector and the connector cap is inserted into an insertion cavity provided in the other of the needle tip protector and the connector cap, thereby providing a tilt limiting portion that limits the relative displacement of the needle tip protector and the connector cap in the twisting direction.

4. The needle assembly according to claim 3, wherein the protruding portion is cylindrical, and the protruding portion and the insertion cavity are provided on either the inner circumference of the needle tip protector or the inner circumference of the connector cap.

5. The needle assembly according to claim 3 or 4, wherein the base end of the needle tip protector is in axial contact with an inner needle hub attached to the base end side of the inner needle.

6. The base end portion of the connector cap is provided with a locking projection that protrudes inward, The locking projection and the needle tip protector are locked in the axial direction, and the connector cap and the needle tip protector are positioned in the axial direction, The needle assembly according to any one of claims 3 to 5, wherein the locking projection is located on the outer circumference of the needle tip protector, and the tilting of the needle tip protector relative to the connector cap is limited by the contact between the locking projection and the needle tip protector.

7. The needle assembly according to any one of claims 3 to 6, wherein the protruding portion protrudes toward the tip side from the needle tip protector, and the protruding portion is inserted into the inner circumference of the base end opening of the outer needle hub.

8. The connector cap is provided with a locking projection that protrudes inward, and the needle tip protector inserted into the inner circumference of the connector cap is positioned axially relative to the connector cap by locking with the locking projection, The connector cap is provided with a cover portion that extends beyond the locking projection toward the base end and covers the outer circumference of the needle tip protector, according to any one of claims 1 to 7.

9. The needle assembly according to claim 8, wherein the cover portion of the needle tip protector covers the outer circumference of the needle tip protector up to its base end.

10. The needle assembly according to claim 8 or 9, wherein the inner needle hub attached to the base end side of the inner needle has a covering portion that covers and conceals the outer circumference of the cover portion.

Images