Needle tip protector

Abstract

[Problem] To provide a needle tip protector with a novel structure, capable of effectively suppressing lateral displacement relative to a puncture needle. [Solution] A needle tip protector 10 is attached to a puncture needle 26, moves toward a needle tip 30 side, and thereby prevents the needle tip 30 from being exposed. A first side plate part 42 and a second side plate part 44 respectively extending, from a bottom part 40 located at the needle root side of the puncture needle 26, to the needle tip 30 side of the puncture needle 26 are provided so as to sandwich the puncture needle 26 from the both sides thereof and to face each other. The first side plate part 42 and the second side plate part 44 are provided with respective lateral cover pieces 62,80 each of which is formed so as to inwardly protrude in the facing direction from one of width direction edge parts on sides opposed to each other in the plate width direction. The puncture needle 26 is positioned between the lateral cover pieces 62,80 of the first side plate part 42 and the second side plate part 44 in the state of being attached to the puncture needle 26.

Description

Needle tip protector

[0001] The present invention relates to a needle tip protector that protects the tip of a puncture needle after use.

[0002] Needle tip protectors that are attached to a puncture needle and move toward the needle tip to protect the needle tip after use have been known. As shown in U.S. Pat. No. 4,929,241 (Patent Document 1), for example, such needle tip protectors have a pair of side plates extending from a bottom portion having an insertion hole for the puncture needle toward the needle tip, and the tip portions of the pair of side plates approach each other to form a needle tip cover that covers the needle tip.

[0003] U.S. Pat. No. 4,929,241

[0004] Incidentally, it is necessary to prevent the needle tip protector from shifting laterally relative to the puncture needle. For example, by preventing the needle tip protector from shifting laterally relative to the puncture needle when attached to the puncture needle or during the operation of withdrawing the puncture needle, the pair of side plates of the needle tip protector can be maintained in a state extending approximately parallel to the puncture needle, thereby stabilizing the operation of withdrawing the puncture needle. Furthermore, by preventing the needle tip protector from shifting laterally relative to the puncture needle after the puncture needle is withdrawn, the needle tip of the puncture needle housed in the needle tip protector can be prevented from being re-exposed.

[0005] In order to prevent the needle tip protector from shifting laterally relative to the puncture needle after the puncture needle is removed, one possible solution is to provide a pair of side walls on both widthwise edges of one side plate of the needle tip protector and to house the puncture needle between the pair of side walls. However, the outer diameter of puncture needles varies, and as the puncture needle becomes thinner, the puncture needle and the side walls may separate, causing rattle and exposing the needle tip to the outside.

[0006] Furthermore, with a needle tip protector of the conventional structure, for example, when the needle tip is covered by the needle tip cover portion on one side panel and the needle tip attempts to move along the needle tip cover portion toward the other side panel, there was a risk that the needle tip would push open the other side panel and become exposed.

[0007] The problem to be solved by the present invention is to provide a needle tip protector of a novel structure that can prevent the needle tip from being re-exposed by preventing at least one of lateral displacement of the puncture needle and pushing open by the needle tip.

[0008] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0009] The first aspect is a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, and comprises a first side plate portion and a second side plate portion that extend from a bottom portion located on the base side of the puncture needle toward the needle tip of the puncture needle, and are arranged opposite each other on both sides of the puncture needle, and the first side plate portion and the second side plate portion are formed with side cover pieces that protrude inward in the opposing direction at each widthwise edge portion that is opposite to each other in the plate width direction, and when attached to the puncture needle, the puncture needle is positioned between the side cover pieces of the first side plate portion and the second side plate portion.

[0010] The needle tip protector constructed according to this aspect has one side cover piece formed on each of the first and second side plates, and these side cover pieces are provided on one widthwise edge portion of each of the side plates that are opposite each other in the plate width direction. Therefore, by setting the distance between the two side cover pieces small, needle tip movement can be suppressed, thereby stabilizing needle tip protection, and the first and second side plates each having one side cover piece can be easily formed.

[0011] The second aspect is a needle tip protector described in the first aspect, in which the centers of the first side plate portion and the second side plate portion in the plate width direction are shifted to the opposite side of each of the side cover pieces.

[0012] With the needle tip protector constructed according to this aspect, the centers of the first and second side plates in the plate width direction are shifted to the opposite side from the side cover pieces, so that the side cover pieces can be formed sufficiently close to the puncture needle while ensuring the plate width dimensions and therefore strength of the first and second side plates. As a result, deformation of the needle tip protector due to external forces acting upon it by contact with the puncture needle is suppressed, and lateral movement of the puncture needle is reliably restricted between the two side cover pieces, thereby achieving improved stability and reliability of the needle tip protection state.

[0013] In a third aspect, in the needle tip protector described in the first or second aspect, the first side plate portion and the second side plate portion are formed with a protruding piece that protrudes inward in the opposing direction at one of the widthwise edge portions located on the opposite side of the side cover piece in the plate width direction, and the protruding piece is located outside the side cover piece.

[0014] If the widthwise edge portions of the first and second side plates opposite the side cover pieces are flat, the needle tip protection state may be easily released by pressing thereon with a finger, etc. With the needle tip protector constructed according to this aspect, the protruding pieces are formed on the widthwise edge portions of the first and second side plates opposite the side cover pieces, making it difficult to press the widthwise edge portions of the first and second side plates with a finger, etc., thereby reducing the risk of the needle tip protection state being released.

[0015] In a fourth aspect, in the needle tip protector described in any one of the first to third aspects, the bottom is formed in a flat plate shape having an insertion hole for the puncture needle, the first side plate portion and the second side plate portion are integrally formed so as to rise from both side edges of the bottom, and the side cover pieces are formed 2.5 mm or more away from the base end sides of the first side plate portion and the second side plate portion, so that a molding space that is open on both sides in the plate width direction is provided on the bottom portion between the opposing surfaces of the base end portions of the first side plate portion and the second side plate portion.

[0016] According to the needle tip protector constructed in accordance with this embodiment, by providing a molding space, the bottom can be supported by a jig (mold) inserted into the molding space, making it possible to efficiently perform press processing such as raising the first side plate portion and the second side plate portion, thereby improving the productivity of the needle tip protector.

[0017] In a fifth aspect, in the needle tip protector described in any one of the first to fourth aspects, in a needle tip protection state in which the first side plate portion and the second side plate portion are close to each other to prevent exposure of the needle tip, the protruding tip of each of the side cover pieces of the first side plate portion and the second side plate portion is pressed against one of the first side plate portion and the second side plate portion.

[0018] With a needle tip protector constructed in accordance with this aspect, when the first side plate portion and the second side plate portion are in a needle tip protection state in which they are close to each other, the force required to displace the first side plate portion and the second side plate portion in a direction separating them from each other becomes greater, making it difficult for the needle tip protection state to be released.

[0019] The sixth aspect is a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent the needle tip from being exposed, and includes a first side plate portion and a second side plate portion that extend from a bottom portion located on the base side of the puncture needle toward the needle tip side of the puncture needle, and are arranged opposite each other on both sides of the puncture needle, and at least one of the first side plate portion and the second side plate portion has a center in the plate width direction that is offset in the plate width direction from the needle axis of the puncture needle, and is provided with a side cover piece that protrudes inward in the opposing direction of the first side plate portion and the second side plate portion at the width edge portion on the side closest to the puncture needle.

[0020] With a needle tip protector constructed in accordance with this aspect, the side cover pieces can be positioned close to the sides of the puncture needle while ensuring the plate width dimensions of the first side plate portion and / or the second side plate portion, thereby achieving both ensuring the deformation rigidity of the needle tip protector and regulating the displacement of the needle tip of the puncture needle by the side cover pieces.

[0021] The seventh aspect is a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, and is provided with a first side plate portion and a second side plate portion that each extend from a bottom portion located on the needle base side of the puncture needle toward the needle tip side of the puncture needle, and at least one of the first side plate portion and the second side plate portion has a notched recessed portion that opens at the side end in the plate width direction, and is provided with a side cover piece that protrudes inward in the opposing direction of the first side plate portion and the second side plate portion at the recessed portion.

[0022] In the needle tip protector constructed according to this aspect, the side cover pieces are provided in the recessed portions formed in the side edges of at least one of the first and second side plates, so that the side cover pieces can be positioned near the center of the side plates in the plate width direction, making it easy to position the side cover pieces close to the puncture needle. Therefore, the side cover pieces effectively prevent the needle tip protector from shifting laterally relative to the puncture needle.

[0023] Since the width dimension of the needle tip protector can be secured to be large on the tip side of the concave portion, the necessary deformation rigidity, etc. of the needle tip protector is secured on the tip side, and for example, the needle tip protection state is not easily released, thereby stably realizing protection of the needle tip of the puncture needle.

[0024] By providing side cover pieces at the portions where the recessed portions with reduced width are formed, the reinforcing effect of the side cover pieces is exerted, thereby preventing localized reduction in the strength of the needle tip protector.

[0025] The eighth aspect is a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent the needle tip from being exposed, and is provided with a first side plate portion and a second side plate portion that each extend from a bottom portion located on the needle base side of the puncture needle toward the needle tip side of the puncture needle, and a needle tip cover portion that protrudes toward the puncture needle is provided on the tip side of at least one of the first side plate portion and the second side plate portion, and a needle tip stop portion that protrudes toward the needle base side is provided on the protruding tip end of the needle tip cover portion.

[0026] In a conventional needle tip protector, for example, when the needle tip is covered by the needle tip cover on one side plate and attempts to move along the needle tip cover toward the other side plate, there is a risk that the needle tip will push open the other side plate and become exposed. In a needle tip protector configured according to this aspect, when the needle tip attempts to move toward the other side plate as described above, the needle tip gets caught on the needle tip stopper provided on the needle tip cover on one side plate, restricting its movement toward the other side plate, thereby preventing the needle tip from coming off the needle tip cover and becoming exposed.

[0027] The ninth aspect is a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent the needle tip from being exposed, and includes a first side plate portion and a second side plate portion that extend from a bottom portion located on the base side of the puncture needle toward the needle tip of the puncture needle, and are arranged opposite each other on both sides of the puncture needle, and a side regulating piece is provided that extends between the opposing first side plate portion and second side plate portion, and the side regulating piece is provided with a regulating protrusion that protrudes toward the puncture needle.

[0028] According to the needle tip protector of this aspect, the restricting protrusion of the side restricting piece abuts against the side of the puncture needle, thereby restricting tilting of the puncture needle and preventing the needle tip from being exposed to the side outside the needle tip protector. In particular, the restricting protrusion is provided so as to protrude from the side restricting piece located between the opposing first and second side plates in a direction approaching the puncture needle, so that the protruding tip of the restricting protrusion can be brought close to the puncture needle, and tilting of the puncture needle can be quickly restricted at small inclination angles.

[0029] In a tenth aspect, in the needle tip protector according to the ninth aspect, the restricting protrusion is provided at an end of the side restricting piece on the needle tip side.

[0030] With the needle tip protector of this aspect, the restricting protrusion easily functions as a wall that prevents the needle tip from being exposed to the outside, thereby reducing the risk of the needle tip being exposed to the outside. Furthermore, because the restricting protrusion abuts against the puncture needle at a position close to the needle tip where the amount of lateral movement increases when the puncture needle tilts, tilting of the puncture needle can be prevented in the early stages of tilting when the tilt angle of the puncture needle is small.

[0031] An eleventh aspect is a needle tip protector described in the ninth or tenth aspect, wherein the lateral regulating piece protrudes inward from the first side plate portion or the second side plate portion in the opposing direction of the first side plate portion and the second side plate portion.

[0032] According to this type of needle tip protector, the side regulating pieces can be extended to a position closer to the needle tip with a relatively small extension length compared to when the side regulating pieces extend from the bottom, for example, which simplifies manufacturing and reduces the rate of defective products.

[0033] The twelfth aspect is a press-molded needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, in which a first side plate portion and a second side plate portion are bent by bending from a bottom portion located on the needle base side of the puncture needle, and each extend toward the needle tip of the puncture needle and are arranged opposite each other, the bottom portion is shaped like a plate having an insertion hole for the puncture needle, the first side plate portion and the second side plate portion are integrally formed so as to rise from both side edges of the bottom portion, and the bottom portion is formed with convex portions that protrude outward in the plate width direction of the first side plate portion and the second side plate portion.

[0034] According to the needle tip protector of this embodiment, when the needle tip protector is formed by cutting it out of a metal plate using a press, the cut surfaces of the portions other than the convex portions can be made smooth and free of burrs. That is, by performing a bending process to form the first and second side plate portions and side cover pieces while the portions other than the convex portions are cut, and then cutting the convex portions to obtain the needle tip protector, the effects of distortions caused by the bending process can be reduced on the cut surfaces other than the convex portions. As a result, the shape and dimensional accuracy of the cut surfaces other than the convex portions can be improved. Furthermore, a smooth shape with reduced burrs can be achieved, simplifying the subsequent deburring process. Furthermore, by holding the cut surfaces other than the convex portions, which have high dimensional and shape accuracy, with a jig or the like, high-precision positioning is possible, thereby improving processing accuracy in the positioned state.

[0035] Furthermore, for example, when the base end of the needle tip protector comes into contact with the inner peripheral surface of the needle hub that houses the needle tip protector, the convex portion that protrudes outward is likely to come into contact with the needle hub, so by performing post-processing such as chamfering only on the convex portion, it is possible to prevent damage to the inner peripheral surface of the needle hub due to contact with the base of the needle tip protector. Therefore, post-processing such as chamfering can be performed more easily than when post-processing such as chamfering is performed on the entire widthwise end face of the bottom.

[0036] The thirteenth aspect is a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, wherein a first side plate portion and a second side plate portion each extending from a bottom portion located on the base side of the puncture needle toward the needle tip side of the puncture needle are arranged opposite each other, sandwiching the puncture needle from both sides, and the tip portions of the first side plate portion and the second side plate portion come relatively close to each other to form a needle tip cover portion that covers the needle tip, and the needle tip cover portion protrudes outward at the base end portion that is on the base side of the puncture needle, and notched relief portions are formed on both sides in the plate width direction at the base end portion of the needle tip cover portion.

[0037] According to the needle tip protector of this aspect, the outer shape of the proximal end of the needle tip shield in the axial view is curved due to the formation of the relief portion, so that when the needle tip protector is inserted proximally into the inner circumference of a needle hub or the like, the proximal end of the needle tip shield, which is the distal portion of the needle tip protector, can be prevented from damaging the inner surface of the needle hub or the like. That is, when the puncture needle is withdrawn, the proximal end of the needle tip shield abuts against the inner surface of the needle hub or the like, thereby realizing relative movement between the needle tip protector and the puncture needle. However, if the outer shape of the proximal end of the needle tip shield in the axial view forms a sharp angle, there is a risk that the proximal end of the needle tip shield will scrape the inner surface of the needle hub. Therefore, by providing a notched relief portion in the proximal end of the needle tip shield and making that portion curved in the axial view, it is possible to reduce the risk of scraping the inner surface of the needle hub when it comes into contact with the needle hub.

[0038] The fourteenth aspect is a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, and comprises a first side plate portion and a second side plate portion that are arranged opposite each other and extend from a bottom portion located on the base side of the puncture needle toward the needle tip side of the puncture needle, the bottom portion being plate-shaped with an insertion hole for the puncture needle, the first side plate portion and the second side plate portion being integrally formed so as to rise from both side edges of the bottom portion, and a thin-walled stress transmission suppression portion being formed on the bottom portion surrounding the insertion hole.

[0039] The insertion hole formed in the bottom portion requires high dimensional accuracy so that it can engage with, for example, a partial enlarged diameter portion formed near the tip of the puncture needle. However, there is a risk that the insertion hole will be deformed by, for example, the force applied during bending of the needle tip protector. Therefore, in this embodiment, a thin-walled portion is provided surrounding the periphery of the insertion hole, so that forces acting from the outer periphery toward the inner periphery of the thin-walled portion are absorbed by the deformation of the thin-walled portion and are less likely to be transmitted to the periphery of the insertion hole located on the inner periphery of the thin-walled portion. Therefore, the insertion hole is less likely to be deformed by the action of external forces, and the dimensions and shape of the insertion hole can be set with high precision.

[0040] According to the present invention, the needle tip protector is prevented from at least one of being displaced laterally relative to the puncture needle and being pushed open by the needle tip, thereby preventing re-exposure of the needle tip.

[0041] 1. Right side view of a needle assembly equipped with a needle tip protector according to a first embodiment of the present invention. 2. II-II sectional view of FIG. 1. 3-III sectional view of FIG. 2. 4-IV sectional view of FIG. 2. 5. Enlarged perspective view of the needle tip protector constituting the needle assembly of FIG. 1. 6. Perspective view of the needle tip protector shown in FIG. 5 from a different angle. 7. Plan view of the needle tip protector shown in FIG. 5. 8. Bottom view of the needle tip protector shown in FIG. 5. 9. Right side view of the needle tip protector shown in FIG. 5. 10. Left side view of the needle tip protector shown in FIG. 5. 11. Front view of the needle tip protector shown in FIG. 5. 16 is an enlarged plan view of the needle tip protector in the needle tip protection state shown in FIG. 14; a bottom view of the needle tip protector in the needle tip protection state shown in FIG. 14; a needle tip protector as a second embodiment of the present invention; 21 is a perspective view showing the needle tip protector of FIG. 21 from a different angle; 21 is a cross-sectional view of the needle tip protector shown in FIG. 20, which corresponds to the XXIII-XXIII cross section of FIG. 24; 21 is a cross-sectional view of the needle tip protector of FIG. 20, which corresponds to the XXIII-XXIII cross section of FIG. 24; 21 is a cross-sectional view of the needle tip part showing the needle tip protected state by the needle tip protector of FIG. 21; 21 is a cross-sectional view of the needle tip part showing the state in which the needle tip has been removed from the second needle tip cover part in the needle tip protected state of FIG. 25; 28. A cross-sectional view showing a part of a needle assembly equipped with a needle tip protector. 29. A perspective view of the needle tip protector constituting the needle assembly of FIG. 27. 30. A perspective view showing the needle tip protector of FIG. 28 at a different angle. 31. A left side view of the needle tip protector shown in FIG. 28. 32. A plan view of the needle tip protector shown in FIG. 28. 33. A front view of the needle tip protector shown in FIG. 28. 34. A rear view of the needle tip protector shown in FIG. 28. 35. A cross-sectional view of the needle tip portion showing the needle tip protected by the needle tip protector of FIG. 28, which corresponds to the XXXIV-XXXIV cross-section of FIG. 35. 36. A cross-sectional view of the XXXV-XXXV cross-section of FIG. 33.

[0042] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0043] 1 to 4 show a needle assembly 12 equipped with a needle tip protector 10 according to a first embodiment of the present invention. The needle assembly 12 is configured by combining an outer needle unit 14 and an inner needle unit 16. In the following description, the front-to-rear direction generally refers to the left-to-right direction in FIG. 1, which is the needle axial direction, the up-down direction generally refers to the up-down direction in FIG. 1, and the left-to-right direction generally refers to the up-down direction in FIG. 2. Furthermore, generally, the left side in FIG. 1, which is the side of the needle tip 30 described below, is the distal end, and the right side in FIG. 1 is the proximal end.

[0044] The outer needle unit 14 has a structure in which an outer needle hub 20 is fixed to the proximal end portion of an outer needle 18. The outer needle 18 is a tubular member made of synthetic resin or the like, and the outer diameter dimension of the distal end portion decreases toward the tip. The proximal end portion of the outer needle 18 is inserted into the distal end portion of the cylindrical outer needle hub 20, and is fixed to the outer needle hub 20 by a crimping pin 22 that is press-fitted into the proximal end portion of the outer needle 18 and the distal end portion of the outer needle hub 20.

[0045] The outer needle hub 20 is a member made of hard synthetic resin and has a generally cylindrical shape overall, with a luer taper on its inner circumferential surface that increases in diameter toward the base end. An external circuit such as a syringe or infusion line can be connected to the inner cavity of the outer needle hub 20 by fitting a syringe tip or connector (not shown) into the inner cavity of the outer needle hub 20. A threaded portion 23 that protrudes outward is formed at the base end of the outer needle hub 20, and by threading the threaded portion 23 into a locking portion (not shown), it is possible to prevent the external circuit such as a syringe or infusion line from unintentionally coming loose from the outer needle hub 20.

[0046] An engaging step portion 24 is formed on the inner circumferential surface of the outer needle hub 20. The engaging step portion 24 is a step provided so as to narrow the inner cavity of the outer needle hub 20 closer to the base end than to the tip end, and as shown enlarged in Fig. 3, the engaging step portion 24 in this embodiment is formed by the side wall surface on the base end side of a recessed groove that opens into the inner circumferential surface of the outer needle hub 20 and extends annularly in the circumferential direction, and is provided continuously around the entire circumference.

[0047] The inner needle unit 16 has a structure in which an inner needle hub 28 is attached to the proximal end portion of an inner needle 26 serving as a puncture needle. The inner needle 26 is a hollow needle made of a medical metal such as stainless steel, and is provided with a sharp needle tip 30 at its distal end. The needle tip 30 is formed by the distal end portion of the inner needle 26 having a cutting edge 32 that extends at an angle relative to the needle axis. The proximal end portion of the inner needle 26 is inserted into the distal end portion of the cylindrical inner needle hub 28, and the inner needle 26 and inner needle hub 28 are fixed together by means of adhesion or the like.

[0048] The inner needle hub 28 is a substantially cylindrical member made of hard synthetic resin. A cylindrical connecting portion 34 that can be fitted into the proximal end opening of the outer needle hub 20 is provided at the distal end of the inner needle hub 28. A filter cap 36 is fitted into the proximal end opening of the inner needle hub 28.

[0049] The outer needle unit 14 and the inner needle unit 16 are combined with each other in a state in which the connecting part 34 of the inner needle hub 28 is fitted into the proximal opening of the outer needle hub 20 and the inner needle 26 is inserted through the outer needle 18 and the outer needle hub 20, thereby constituting the needle assembly 12. When a tensile force directed towards the proximal end of the outer needle unit 14 acts on the inner needle unit 16, the fitting of the connecting part 34 with the outer needle hub 20 is released, and the outer needle unit 14 and the inner needle unit 16 can be separated from each other.

[0050] A needle tip protector 10 is attached to the inner needle 26. The needle tip protector 10 is formed from a metal material such as medical stainless steel. In this embodiment, the various components that make up the needle tip protector 10, which will be described later, are integrally formed, and the needle tip protector 10 can be easily manufactured by, for example, pressing a metal plate.

[0051] As shown in Figures 5 to 12, the needle tip protector 10 has a structure in which a first side plate portion 42 and a second side plate portion 44 extend from both end edges of a bottom portion 40 located on the needle base side (opposite the needle tip 30) of the inner needle 26 toward the needle tip 30. Note that, for ease of viewing, Figures 5 to 12 show the needle tip protector 10 in a state before activation (before needle tip protection), but the needle tip protector 10 may be formed in a form after activation (needle tip protection state) and may be placed in the pre-activation state shown in Figures 5 to 12 by being attached to the inner needle 26.

[0052] As shown in Fig. 6, the bottom portion 40 has a substantially rectangular flat plate shape and is provided with an insertion hole 46 penetrating in the plate thickness direction. A first side plate portion 42 and a second side plate portion 44 are integrally formed on a pair of opposing sides of the bottom portion 40 and extend to one side in the plate thickness direction of the bottom portion 40. The first side plate portion 42 and the second side plate portion 44 in this embodiment are arranged opposite to each other with the inner needle 26 sandwiched between them, and do not extend in a crosswise manner.

[0053] The first side plate portion 42 has a generally rectangular plate shape overall, and is elongated in the length direction (left-right direction in FIG. 7 ), which is the direction in which it extends from the bottom portion 40. The first side plate portion 42 includes a first main body portion 48 extending from the bottom portion 40, and a first needle tip protection portion 50 located distally of the first main body portion 48. The first side plate portion 42 preferably has a plate width dimension of 1 to 5 mm. This ensures sufficient deformation rigidity in the first side plate portion 42, effectively fulfilling functions such as guiding the withdrawal of the inner needle 26 and protecting the needle tip 30 of the inner needle 26, and also prevents the mold (a holding jig described later) for bending the metal blank from becoming excessively elongated during press-molding of the first side plate portion 42 described later, thereby ensuring the durability of the mold. In the following description of the needle tip protector 10, the length direction generally refers to the vertical direction in FIG. 7, which is the direction in which the first and second side plate portions 42, 44 extend from the bottom 40, and the width direction generally refers to the vertical direction in FIG. 9, which is the plate width direction of the first and second side plate portions 42, 44.

[0054] The first needle tip protection portion 50 includes a first tip protection piece 52 that protrudes toward the tip while inclining toward the second side plate portion 44. A first return piece 54 is provided at the tip side of the first tip protection piece 52, protruding toward the second side plate portion 44 while inclining toward the bottom portion 40. A pair of side cover pieces 56, 56 are provided on both widthwise sides of the tip portion of the first tip protection piece 52, extending approximately perpendicular to the width direction and protruding in approximately the same direction as the first return piece 54. The base end of the first tip protection piece 52 includes a first step portion 58 that protrudes outward toward the second side plate portion 44, and the first step portion 58 is integrally continuous with the tip of the first main body portion 48. In other words, the first step portion 58 causes the base end of the first tip protection piece 52 to be offset from the tip of the first main body portion 48 on the side opposite the second side plate portion 44.

[0055] A first notch 60 is formed in the tip edge portion of the first return piece 54 protruding from the first tip protection piece 52. As shown in Fig. 11 , the first notch 60 is provided in the central portion in the width direction of the first return piece 54, and its widthwise dimension is larger than the wall thickness dimension (axial dimension) of the first return piece 54, and it extends in the width direction for a length shorter than the width dimension of the first return piece 54. The inner surface of the first notch 60 is formed into a curved surface in a substantially circular arc shape with a smaller curvature than the outer peripheral surface of the inner needle 26, and the depth dimension of the first notch 60 increases toward the center in the width direction. The inner surface of the first notch 60 is formed into an arc shape that is less than halfway around the circumference, and the length dimension of the first notch 60 in the width direction is larger than the diameter of the inner needle 26.

[0056] The first main body 48 is provided with a first side cover piece 62. As shown in Figures 7 and 9, the first side cover piece 62 extends from one widthwise edge of the first main body 48 toward the second side plate 44 and is provided at a midpoint in the lengthwise direction of the first main body 48, biased toward the tip.

[0057] That is, a first recessed portion 64 opens at one widthwise edge of the first main body portion 48, and the first main body portion 48 is narrowed where the first recessed portion 64 is formed. As shown in FIG. 9 , the first recessed portion 64 is a notch-shaped notch penetrating the first main body portion 48 in the plate thickness direction, and is provided in the middle portion of the first main body portion 48 in the front-rear direction, but does not reach both front-rear ends of the first main body portion 48. Therefore, the first main body portion 48 is narrower at the portion where the first recessed portion 64 is formed than at both the front and rear outer sides of the first recessed portion 64. At both front and rear end portions, the vertical depth of the first recessed portion 64 decreases toward the outer sides in the front-rear direction. In other words, the length of the first recessed portion 64 increases toward the lateral opening. The depth of the first recessed portion 64 is greatest on both front-rear sides of the first side cover piece 62.

[0058] The first side cover piece 62 is provided at the bottom of the first recessed portion 64, protruding inward in the left-right direction, and is located widthwise inward relative to the widthwise outer end of the first main body portion 48, which includes the open end of the first recessed portion 64. The first side cover piece 62 has a substantially constant protruding height from the first side plate portion 42 at its base end portion near the bottom portion 40, and the protruding height gradually decreases toward the tip at its tip portion near the first needle tip protection portion 50. The first side cover piece 62 preferably has a length dimension of 1 to 5 mm and a maximum protruding height dimension of 1 to 3 mm from the first main body portion 48. This ensures that, for example, in the needle tip 30 protection state described below, the first side cover piece 62 reliably covers the side of the inner needle 26, and prevents malfunctions and the like due to contact between the protruding tip of the first side cover piece 62 and the second side plate portion 44.

[0059] The first main body portion 48 is provided with a first protruding piece 66. As shown in FIG. 8 , the first protruding piece 66 extends from the other widthwise edge of the first main body portion 48 toward the second side plate portion 44 and is located at a longitudinally intermediate position of the first main body portion 48, biased toward the tip. The first protruding piece 66 is located on the edge of the first main body portion 48 opposite the first side cover piece 62 and is disposed widthwise opposite the first side cover piece 62 with a space between them. In this embodiment, the first side cover piece 62 and the first protruding piece 66 extend substantially parallel to each other. As shown in FIG. 7 , the first protruding piece 66 has a longer length (vertical dimension in FIG. 7 ) than the first side cover piece 62 and extends to both longitudinally outer sides of the first side cover piece 62. The protruding height of the first protruding piece 66 from the first main body portion 48 is substantially the same as that of the first side cover piece 62. Like the first side cover piece 62, the first protruding piece 66 has a substantially constant protruding height at the base end in the longitudinal direction, and the protruding height at the tip end in the longitudinal direction decreases toward the tip.

[0060] The center position in the opposing direction (width direction) of the first side cover piece 62 and the first protruding piece 66, indicated by the dashed line in Fig. 9, is shifted toward the first protruding piece 66 in the width direction relative to the center position in the width direction of the bottom portion 40, indicated by the dashed line in Fig. 9. In other words, the first recessed portion 64 is formed in the portion of the first main body portion 48 where the first side cover piece 62 and the first protruding piece 66 are formed, so that the center in the plate width direction of the first main body portion 48 (the dashed line in Fig. 9) is shifted toward the opposite side of the first side cover piece 62 (the side toward the first protruding piece 66) in the width direction relative to the center in the same direction of the bottom portion 40 (the dashed line in Fig. 9). Note that the center position of the bottom portion 40 approximately coincides with the central axis of the insertion hole 46, and therefore approximately coincides with the needle axis of the inner needle 26 inserted through the insertion hole 46, and therefore the dashed line in Fig. 9 indicates the width direction position of the needle axis of the inner needle 26.

[0061] On the other hand, the second side plate 44 is generally rectangular overall, and is elongated in the direction of its extension from the bottom 40 (the vertical direction in FIG. 7). The second side plate 44 includes a second main body 68 extending from the bottom 40, and a second needle tip protection part 70 located on the distal side of the second main body 68. The second side plate 44 preferably has a plate width dimension of 1 to 5 mm.

[0062] The second needle tip protection portion 70 has a second tip protection piece 72 that slopes toward the first side plate portion 42 as it extends toward the tip, and a second return piece 74 is provided on the tip side of the second tip protection piece 72, which slopes toward the bottom portion 40 and protrudes toward the first side plate portion 42. The base end of the second tip protection piece 72 has a second step portion 76 that protrudes outward toward the first side plate portion 42, and the second step portion 76 is integrally continuous with the tip of the second main body portion 68 of the second side plate portion 44. In other words, the base end of the second tip protection piece 72 is offset by the second step portion 76 to the opposite side from the first side plate portion 42 with respect to the tip of the second main body portion 68. The second needle tip protection part 70 is not provided with side cover pieces corresponding to the side cover pieces 56, 56 of the first needle tip protection part 50, and the sides of the second needle tip protection part 70 are open and not covered. In short, the pair of side cover pieces 56, 56 on both sides in the plate width direction are both provided on the first needle tip protection part 50.

[0063] A second notch 78 is formed in the tip edge of the second return piece 74 protruding from the second tip protection piece 72. As shown in Fig. 11 , the second notch 78 is provided in the central portion in the width direction of the second return piece 74, and its widthwise dimension is larger than the wall thickness dimension (axial dimension) of the second return piece 74, and it extends in the width direction for a length shorter than the width dimension of the second return piece 74. The inner surface of the second notch 78 is formed into a curved surface in a substantially circular arc shape with a smaller curvature than the outer peripheral surface of the inner needle 26, and the depth dimension of the second notch 78 increases toward the center in the width direction. The inner surface of the second notch 78 is formed into an arc shape that is less than halfway around the circumference, and the length dimension of the second notch 78 in the width direction is larger than the diameter of the inner needle 26.

[0064] The second main body 68 is provided with a second side cover piece 80. As shown in Figures 8 and 10, the second side cover piece 80 extends from one widthwise edge of the second main body 68 toward the first side plate 42 and is provided at a midpoint in the lengthwise direction of the second main body 68, biased toward the tip.

[0065] That is, a second recessed portion 82 opens at one side end of the second main body portion 68, and the second main body portion 68 is narrowed at the second recessed portion 82. As shown in FIG. 10 , the second recessed portion 82 is a notch-shaped portion that penetrates the second main body portion 68 in the plate thickness direction and is provided in the middle portion of the second main body portion 68 in the front-rear direction, but does not reach both front-rear ends of the second main body portion 68. Therefore, the second main body portion 68 is narrower at the portion where the second recessed portion 82 is formed than at both the front and rear outer sides of the second recessed portion 82. At both front and rear end portions, the vertical depth of the second recessed portion 82 decreases toward the outer sides in the front-rear direction. In other words, the length of the second recessed portion 82 increases toward the lateral opening. The depth of the second recessed portion 82 is greatest at both the front-rear and rear ends of the second side cover piece 80.

[0066] The second side cover piece 80 is provided at the bottom of the second recessed portion 82 so as to protrude inward in the left-right direction, and is located widthwise inward relative to the outer widthwise edge of the second main body portion 68, which includes the open end of the second recessed portion 82. The second side cover piece 80 has a substantially constant protruding height from the second side plate portion 44 at its base end portion close to the bottom 40, and the protruding height gradually decreases toward the tip at its tip portion close to the second needle tip protection portion 70. The second side cover piece 80 preferably has a length dimension of 1 to 5 mm, and a maximum protruding height dimension of 1 to 3 mm from the second main body portion 68.

[0067] The second main body portion 68 is provided with a second protruding piece 84 as a protruding piece. As shown in FIG. 7 , the second protruding piece 84 extends from the other widthwise edge of the second main body portion 68 toward the first side plate portion 42 and is provided at a longitudinally intermediate position of the second main body portion 68, biased toward the tip. The second protruding piece 84 is provided on the edge of the second main body portion 68 opposite the second side cover piece 80 and is arranged spaced apart and facing the second side cover piece 80 in the widthwise direction. In this embodiment, the second side cover piece 80 and the second protruding piece 84 extend substantially parallel to each other. As shown in FIG. 8 , the second protruding piece 84 has a longer length (vertical dimension in FIG. 8 ) than the second side cover piece 80 and extends to both longitudinally outer sides of the second side cover piece 80. The protruding height of the second protruding piece 84 from the second main body portion 68 is substantially the same as that of the second side cover piece 80. Like the second side cover piece 80, the second protruding piece 84 has a substantially constant protruding height at the base end portion in the longitudinal direction, and the protruding height at the tip end portion in the longitudinal direction decreases toward the tip.

[0068] The center position in the opposing direction (width direction) of the second side cover piece 80 and the second protruding piece 84, shown by the dashed line in Fig. 10, is shifted in the width direction toward the second protruding piece 84 with respect to the center position in the width direction of the bottom portion 40, shown by the dashed line in Fig. 10. In other words, in the portion of the second main body portion 68 where the second side cover piece 80 and the second protruding piece 84 are formed, the center in the plate width direction of the second main body portion 68 (dashed line in Fig. 10) is shifted in the width direction toward the opposite side of the second side cover piece 80 (the side toward the second protruding piece 84) with respect to the center in the same direction of the bottom portion 40 (dashed line in Fig. 10). Therefore, the center in the plate width direction of the portion of the first main body portion 48 where the first side cover piece 62 and the first protruding piece 66 are formed (dotted line in Fig. 9) and the center in the plate width direction of the portion of the second main body portion 68 where the second side cover piece 80 and the second protruding piece 84 are formed (dotted line in Fig. 10) are offset from each other toward the opposite side of the side cover pieces 62, 80. Note that, like the two-dot chain line in Fig. 9, the two-dot chain line in Fig. 10 also substantially coincides with the width direction position of the needle shaft of the inner needle 26.

[0069] The first side cover piece 62 and the second protruding piece 84 are provided on the edge portions of the first side plate portion 42 and the second side plate portion 44 on the same widthwise side, and overlap each other widthwise when attached to the inner needle 26 before needle tip protection. As shown in FIG. 12 , the first side cover piece 62 is located on the inside of the second protruding piece 84 widthwise. The first side cover piece 62 has a protruding height that does not reach the second side plate portion 44, and the second protruding piece 84 has a protruding height that does not reach the first side plate portion 42, and the first side cover piece 62 and the second protruding piece 84 partially overlap each other. Furthermore, as shown in FIG. 7 , the second protruding piece 84 extends outward from the first side cover piece 62 on both longitudinal sides. The longitudinal center position of the second protruding piece 84 is biased away from the longitudinal center position of the first side cover piece 62 toward the opposite side from the bottom portion 40 (toward the tip).

[0070] The second side cover piece 80 and the first protruding piece 66 are provided on the edge portions of the first side plate portion 42 and the second side plate portion 44 on the same widthwise side, and overlap each other widthwise when attached to the inner needle 26 before needle tip protection. As shown in FIG. 12 , the second side cover piece 80 is located on the inside of the first protruding piece 66 in the widthwise direction. The second side cover piece 80 has a protruding height that does not reach the first side plate portion 42, and the first protruding piece 66 has a protruding height that does not reach the second side plate portion 44, and the second side cover piece 80 and the first protruding piece 66 partially overlap. As shown in FIG. 8 , the first protruding piece 66 extends outward from the second side cover piece 80 in the longitudinal direction. The longitudinal center position of the first protruding piece 66 is biased toward the bottom portion 40 relative to the longitudinal center position of the second side cover piece 80.

[0071] The first side cover piece 62 and the second side cover piece 80 are provided on opposite sides in the width direction, facing each other at a distance in the width direction. The first protruding piece 66 and the second protruding piece 84 are provided on opposite sides in the width direction, facing each other at a distance in the width direction, and positioned on both outer sides of the first and second side cover pieces 62, 80 in the width direction.

[0072] In this embodiment, the first side cover piece 62 has a longer length than the second side cover piece 80, with its tip end positioned substantially the same as that of the second side cover piece 80 and its base end positioned closer to the bottom 40 than the second side cover piece 80. The first protruding piece 66 and the second protruding piece 84 have substantially the same length, with the first protruding piece 66 being shifted closer to the bottom 40 than the second protruding piece 84.

[0073] As shown in Figures 7 and 8, the first and second side cover pieces 62, 80 and the first and second protruding pieces 66, 84 are all spaced apart longitudinally from the bottom portion 40 toward their distal ends. A molding space 86 is formed between the bottom portion 40 and the first and second side cover pieces 62, 80 and the first and second protruding pieces 66, 84, penetrating the widthwise direction between the opposing surfaces of the first and second side plate portions 42, 44 and opening to both sides in the widthwise direction. The first and second side cover pieces 62, 80 and the first and second protruding pieces 66, 84 are preferably spaced apart from the base ends of the first and second side plate portions 42, 44 (the distal ends of the bottom portion 40) by at least 2.5 mm, and more preferably at least 3.5 mm. In other words, the longitudinal dimension of the molding space 86 is preferably at least 2.5 mm, and more preferably at least 3.5 mm. Furthermore, the longitudinal dimension of the molding space 86 is preferably 7 mm or less, and more preferably 5 mm or less, which prevents the mold (pressing jig described later) inserted into the molding space 86 from becoming excessively thin in the longitudinal direction, ensuring the strength and durability of the mold, and also reducing the length of the needle tip protector 10, thereby enabling the outer needle hub 20 that houses the needle tip protector 10 to be made smaller.

[0074] The needle tip protector 10 is formed, for example, by bending a metal blank punched into a predetermined shape using a press (progressive press). During the press, the bottom portion 40 can be pressed down using the forming space 86. That is, during the press, the portion corresponding to the bottom portion 40 is clamped in the plate thickness direction between a support jig (not shown) that supports one side and a clamping jig (not shown) that supports the other side. The clamping jig is shaped to be insertable into the forming space 86 and is overlapped with the rising sides of the first and second side plate portions 42, 44 relative to the bottom portion 40. This allows the bottom portion 40 to be held in a clamped state from the start to the end of the press, facilitating the molding of the needle tip protector 10. The clamping jig also functions as a mold when bending and molding the first and second side plate portions 42, 44 relative to the bottom portion 40. The metal plate processed into the needle tip protector 10 by the progressive press is made of, for example, medical-grade stainless steel or titanium, and is preferably a plate material having a thickness of 0.1 to 0.3 mm. By using a metal plate with such a thickness range, it is possible to obtain a needle tip protector 10 that has sufficiently small sliding resistance against the inner needle 26 and deformation rigidity that can stably maintain the needle tip protection form, and damage during press processing is unlikely to be a problem. The needle tip protector 10 may have a substantially constant thickness overall, or may have thick and / or thin portions.

[0075] The needle tip protector 10 constructed as above is attached to the inner needle 26, as shown in Fig. 13. That is, the inner needle 26 is inserted through the insertion hole 46 formed in the bottom 40 of the needle tip protector 10, and is also inserted between the first return piece 54 of the first needle tip protection part 50 and the second return piece 74 of the second needle tip protection part 70. As a result, the inner needle 26 is disposed passing through the space between the opposing first side plate part 42 and second side plate part 44 of the needle tip protector 10, and the needle tip protector 10 is attached in an externally fitted state to the inner needle 26. The inner needle 26 is located between the opposing first side cover piece 62 and second side cover piece 80 of the needle tip protector 10, and is surrounded around a part of the needle axial direction by the first and second side plate parts 42, 44 and the first and second side cover pieces 62, 80. In Figure 13, for ease of viewing, the needle tip protector 10 is positioned away from the inner needle hub 28 toward the needle tip 30, but as shown in Figures 2 and 3, the needle tip protector 10 can be positioned so that the bottom 40 is in contact with or close to the tip of the inner needle hub 28.

[0076] 2 and 4 , when the needle tip protector 10 is attached to the inner needle 26, the inner needle 26 is inserted into the first notch 60 of the first return piece 54 and the second notch 78 of the second return piece 74, and the inner surfaces of the first and second notches 60, 78 are in contact with the outer circumferential surface of the inner needle 26. When the first and second return pieces 54, 74 are in contact with the inner needle 26 at the first and second notches 60, 78, the first and second side plate portions 42, 44 are elastically deformed, and the first and second return pieces 54, 74 are pressed against the inner needle 26 by the elastic restoring forces of the first and second side plate portions 42, 44. The inner surfaces of the first and second notches 60, 78 have a smaller curvature than the outer peripheral surface of the inner needle 26, so that the contact area between the inner needle 26 and the first and second return pieces 54, 74 at the first and second notches 60, 78 is reduced.

[0077] Furthermore, when the needle tip protector 10 is attached to the inner needle 26, the needle axis of the inner needle 26 is offset in the width direction of the first side plate 42 toward the first side cover piece 62 with respect to the center in the width direction of the first side plate 42 of the needle tip protector 10. Furthermore, the needle axis of the inner needle 26 is offset in the width direction of the second side plate 44 toward the second side cover piece 80 with respect to the center in the width direction of the second side plate 44 of the needle tip protector 10. In other words, the first and second side cover pieces 62, 80 are provided on the widthwise edge portions of the first and second side plates 42, 44 that are arranged offset in the width direction with respect to the needle axis of the inner needle 26.

[0078] As shown in Figures 2 to 4, the needle tip protector 10 is housed in the inner cavity of the outer needle hub 20. The tip portion of the needle tip protector 10 has a tapered shape due to the first and second tip protective pieces 52, 72 being inclined toward each other toward the tip, which prevents the needle tip protector 10 from being unintentionally caught and damaging the inner surface of the outer needle hub 20 when the needle tip protector 10 is inserted into the outer needle hub 20. The first and second stepped portions 58, 76 of the needle tip protector 10 have both widthwise end portions axially engaged with engaging stepped portions 24 provided on the inner surface of the outer needle hub 20, limiting movement toward the base end relative to the outer needle hub 20. Furthermore, when the needle tip protector 10 is attached in this manner, in order to suppress unnecessary rattle of the needle tip protector 10 relative to the inner needle 26, for example, the outermost square portion of the bottom portion 40 or the needle tip covering portion 50, 70 may be arranged in close proximity to or in contact with the inner peripheral surface of the outer needle hub 20. Furthermore, in order to suppress free rotation of the needle tip protector 10 around the inner needle 26 in this attached state, the connecting portion 34 of the inner needle hub 28 inserted into the outer needle hub 20 may be made to protrude partially circumferentially toward the tip side (see Figures 3 and 13), and this protruding portion may be made to enter outside the outer periphery of the bottom portion 40 of the needle tip protector 10.

[0079] In a needle assembly 12 equipped with such a needle tip protector 10, for example, the inner needle 26 and the outer needle 18 are inserted into a patient's blood vessel, etc. When a blood vessel is punctured, blood flows into the lumen of the inner needle hub 28 through the lumen of the inner needle 26. Therefore, by making the inner needle hub 28 transparent or translucent so that the interior can be seen, for example, it is possible to confirm that the inner needle 26 has punctured the blood vessel by checking the flow of blood into the inner needle hub 28. Furthermore, the filter 38 of the filter cap 36 attached to the inner needle hub 28 can prevent blood that has flowed into the lumen of the inner needle hub 28 from leaking out through the opening on the proximal end side.

[0080] After the inner needle 26 and the outer needle 18 have punctured the blood vessel, the inner needle unit 16 can be pulled toward the proximal end while holding the outer needle unit 14 in the puncture position, thereby pulling the inner needle 26 toward the proximal end from the outer needle 18. At this time, the connection between the inner needle hub 28 and the outer needle hub 20 is released, and the entire inner needle unit 16 is separated from the outer needle unit 14.

[0081] When the inner needle 26 is withdrawn toward the proximal end, the edge portions of the first and second return pieces 54, 74 of the needle tip protector 10 come into sliding contact with the outer circumferential surface of the inner needle 26. Because the first and second return pieces 54, 74 are inclined toward the proximal end toward the inner needle 26, when the inner needle 26 is withdrawn, the edge portions of the first and second return pieces 54, 74 are less likely to get caught on minute irregularities on the outer circumferential surface of the inner needle 26, sliding resistance is reduced, and smooth withdrawal of the inner needle 26 toward the proximal end is achieved.

[0082] When the inner needle 26 is pulled out toward the proximal end, the inner needle 26 is guided in the axial direction by the first and second notches 60, 78 provided on the first and second barbed pieces 54, 74 of the needle tip protector 10, thereby assisting in smooth pulling out of the inner needle 26 toward the proximal end. Because the length dimension of the first and second notches 60, 78 in the width direction (left and right direction in FIG. 4 ) is made larger than the diameter of the inner needle 26, even if the inner needle 26 moves slightly in the width direction, it is unlikely to come off the first and second notches 60, 78, and the guiding function of the inner needle 26 by the first and second notches 60, 78 is effectively exerted.

[0083] The first and second notches 60, 78 are formed to extend in the width direction of the first and second return pieces 54, 74, and therefore the inner needle 26 and the first and second return pieces 54, 74 are in contact over a narrow range in the needle axial direction, and for example, sliding resistance due to surface roughness at the contacting portions is reduced, facilitating the operation of withdrawing the inner needle 26. The member thickness dimension of the first and second return pieces 54, 74 is sufficiently small compared with the outer diameter of the inner needle 26, and particularly in this embodiment, the tip surfaces of the first and second return pieces 54, 74, including the first and second notches 60, 78, are approximately perpendicular to the plate surface, and therefore the inner needle 26 and the first and second return pieces 54, 74 are in approximate line contact or point contact in the attached state shown in Figure 2.

[0084] Furthermore, the curvature of the inner surfaces of the first and second notches 60, 78 is smaller than the curvature of the outer peripheral surface of the inner needle 26, and the contact area in the circumferential direction between the first and second return pieces 54, 74 and the inner needle 26 is narrowed, which also reduces resistance during withdrawal. In this manner, in the present embodiment, the inner needle 26 and the first and second return pieces 54, 74 are in contact with each other in a substantially point-contact state at one location, and sliding resistance due to contact is sufficiently reduced.

[0085] The outer needle unit 14 separated from the inner needle unit 16 is left in place as an indwelling needle inserted into a blood vessel, and an external circuit (not shown) is connected to the base end of the outer needle hub 20, thereby functioning as an access port to the blood vessel and being used, for example, as an inlet for administering infusion or medicinal fluid, or as a blood removal or return port for artificial dialysis.

[0086] 14 to 17 , when the inner needle 26 is pulled out from the outer needle 18, the needle tip 30 of the inner needle 26 is covered by the needle tip protector 10, which has moved toward the needle tip 30 relative to the inner needle 26. That is, when the inner needle 26 moves toward the proximal end relative to the needle tip protector 10, whose movement toward the proximal end is restricted by the outer needle hub 20, the abutment between the outer peripheral surface of the inner needle 26 and the first and second return pieces 54, 74 is released, and the first and second side plate portions 42, 44 elastically restore their shapes. As a result, the first and second side plate portions 42, 44 incline so as to approach each other toward the distal end, and the first needle tip protection portion 50 and the second needle tip protection portion 70 are both displaced to positions covering the distal end side of the inner needle 26, and a needle tip cover that covers the needle tip 30 is formed by the first and second needle tip protection portions 50, 70. This prevents the needle tip 30 of the inner needle 26 from being exposed toward the tip, and the movement of the inner needle 26 toward the tip is restricted by contact with the first and second needle tip protection portions 50, 70, thereby avoiding the risk of accidental puncture due to exposure of the inner needle 26.

[0087] When the needle tip protector 10 is in the needle tip protection state as described above, the first and second return pieces 54, 74 of the first and second needle tip protection parts 50, 70 overlap each other at the tip side of the needle tip 30, and the tip side of the inner needle 26 is doubly covered by the first and second needle tip protection parts 50, 70, thereby ensuring high safety.

[0088] The needle tip 30 is covered so as to be difficult to see from the outside by a pair of side cover pieces 56, 56 provided on the first needle tip protection part 50. Furthermore, even if the needle tip 30 moves toward the distal end, the pair of side cover pieces 56, 56 prevents the needle tip 30 from leaving the first and second needle tip protection parts 50, 70 in the width direction (the vertical direction in Figure 17) and becoming exposed to the outside.

[0089] Furthermore, as shown in Figure 16, the pair of side cover pieces 56, 56 are positioned to the sides of the second tip protection piece 72 and the second return piece 74 in the needle tip protection state. As a result, relative displacement of the first needle tip protection part 50 and the second needle tip protection part 70 to the side (direction perpendicular to the paper surface of Figure 16) is limited by the abutment of the side cover piece 56 with the second tip protection piece 72 and the second return piece 74. Therefore, re-exposure of the needle tip 30 due to unintended relative displacement of the first and second needle tip protection parts 50, 70 to the side is prevented.

[0090] 18 and 19, the first and second main body portions 48, 68 of the first and second side plate portions 42, 44 approach each other toward their tips, and as shown in Fig. 16, the tip portions of the first and second main body portions 48, 68 are close in the left-right direction to the inner needle 26. This limits the amount of displacement (deflection) of the inner needle 26 in the opposing direction (left-right direction) of the first and second main body portions 48, 68, preventing exposure of the needle tip 30 due to displacement in the left-right direction, etc.

[0091] 17, in the needle tip protection state, the first and second side cover pieces 62, 80 provided on the first and second side plate portions 42, 44 are close in the vertical direction to the tip portion of the inner needle 26. This limits the amount of displacement (vibration) of the inner needle 26 in the opposing direction (vertical direction) of the first and second side cover pieces 62, 80, and prevents exposure of the needle tip 30 due to vertical displacement, etc.

[0092] Because the first side cover piece 62 is provided on the first side plate portion 42 and the second side cover piece 80 is provided on the second side plate portion 44, the needle tip protector 10 can be easily formed by press working or the like even if the opposing distance between the first side cover piece 62 and the second side cover piece 80 is set small. Therefore, for a thin medical inner needle 26 of, for example, 16 to 24 G, both the first and second side cover pieces 62, 80 can be positioned sufficiently close to the inner needle 26, effectively limiting vertical displacement of the inner needle 26. Furthermore, by appropriately setting the offset between the centers of the first side plate portion 42 and the second side plate portion 44 in the plate width direction according to the thickness (gauge) of the inner needle 26, both the first and second side cover pieces 62, 80 can be positioned sufficiently close to the inner needle 26 while ensuring the component strength of the needle tip protector 10, even when used with a thin inner needle 26 of, for example, 24 G.

[0093] In this embodiment, the first side cover piece 62 is provided so as to protrude inward in the vertical direction from the first recessed portion 64 of the first side plate portion 42, and the second side cover piece 80 is provided so as to protrude inward in the vertical direction from the second recessed portion 82 of the second side plate portion 44, thereby enabling the first and second side cover pieces 62, 80 to be positioned close to the inner needle 26, respectively.

[0094] The first side plate 42 is wide on both sides away from the first recessed portion 64 in the front-to-rear direction, ensuring rigidity against deformation. Furthermore, the first side plate 42 is integrally provided with the first side cover piece 62 that protrudes inward at the narrow portion where the first recessed portion 64 is formed, and therefore the reinforcing action of the first side cover piece 62 ensures rigidity against deformation. Similar to the first side plate 42, the second side plate 44 also ensures rigidity against deformation at the portion where the second recessed portion 82 is formed and on both the front and rear sides thereof.

[0095] The first and second side cover pieces 62, 80 have inclined tips that protrude from the first and second side plate portions 42, 44 in consideration of the needle tip protection state, and therefore do not interfere with the first and second side plate portions 42, 44 when the first and second side plate portions 42, 44 are in the inclined needle tip protection state. Therefore, deformation (shape restoration) of the first and second side plate portions 42, 44 occurs reliably without being hindered by the first and second side cover pieces 62, 80, and the needle tip protector 10 stably transitions to the intended needle tip protection form.

[0096] The first side plate portion 42 protrudes outward in the width direction beyond the second side cover piece 80, thereby ensuring a sufficient width dimension and strength, such as deformation rigidity. If the first side plate portion 42 protrudes outward in the width direction beyond the second side cover piece 80, there is a risk that the protection state of the needle tip 30 provided by the needle tip protector 10 will be released if the protruding portion is pressed by hand, for example. Therefore, by providing the first protruding piece 66 on the protruding portion, the protruding portion is made difficult to press, and the needle tip protection state of the needle tip protector 10 is stably maintained. In the needle tip protection state, the first protruding piece 66 reaches a position that covers the side of the second side plate portion 44, as shown in FIG. 19 . Even if the first protruding piece 66 is pressed by a finger, the finger is caught on the second side plate portion 44, making it difficult to press the first protruding piece 66 deeply, and therefore the needle tip protection state is unlikely to be released.

[0097] Similarly, the second protruding piece 84 provided on the second side plate 44 makes it difficult for the portion of the second side plate 44 that protrudes widthwise outward beyond the first lateral cover piece 62 to be pushed in when in the needle tip protection state, thereby preventing the needle tip protection state from being released. As shown in Figure 18, the second protruding piece 84 is provided with a protruding height that does not reach the first side plate 42 slightly, but because the protruding tip is close to the first side plate 42, like the first protruding piece 66, it is difficult for a finger or the like to get caught on the first side plate 42 and push it in.

[0098] Incidentally, the needle tip protector 10, which protects the needle tip 30 of the inner needle 26 while housed in the outer needle hub 20, separates from the outer needle hub 20 and moves away toward the base end as the inner needle 26 is pulled out toward the base end. That is, in the needle tip protection state, the first and second side plate portions 42, 44 deform so as to approach each other toward the tip, and therefore the axial engagement between the first and second stepped portions 58, 76 and the engaging stepped portion 24 of the outer needle hub 20 is released, allowing the needle tip protector 10 to move toward the base end relative to the outer needle hub 20.

[0099] 12, 16 and 17, a large-diameter portion 88 having a partially enlarged outer diameter is provided near the tip of the inner needle 26, and the outer diameter of the large-diameter portion 88 is larger than the inner diameter of the insertion hole 46 formed in the bottom portion 40 of the needle tip protector 10. As a result, when the inner needle 26 in the needle tip protected state is pulled further toward the base end, the large-diameter portion 88 of the inner needle 26 is engaged with the bottom portion 40 of the needle tip protector 10 in the needle axial direction, and the needle tip protector 10 moves toward the base end together with the inner needle 26. Therefore, the needle tip protector 10, while protecting the needle tip 30 of the inner needle 26, separates from the outer needle hub 20, which is left in a state of being inserted into the blood vessel. In this way, when the inner needle unit 16 is separated from the outer needle unit 14, the needle tip 30 of the inner needle 26 is covered by the needle tip protector 10, so that when handling the inner needle unit 16 after separation, it is possible to prevent accidental contact with the needle tip 30 of the inner needle 26, thereby ensuring safety.

[0100] Figure 20 shows a needle assembly 92 equipped with a needle tip protector 90 according to a second embodiment of the present invention. The needle tip protector 90 is shown in Figures 21 to 24 and comprises a first side plate portion 94 and a second side plate portion 96 that extend from the bottom portion 40 toward the needle tip 30 (left side in Figure 23). In the following description, members and parts that are substantially the same as those in the first embodiment are given the same reference numerals in the figures and description thereof will be omitted.

[0101] In the present embodiment, the bottom portion 40 is provided with a thin-walled portion 97 that serves as a stress transmission suppression portion extending in a substantially rectangular ring shape and that surrounds the periphery of the insertion hole 46. The bottom portion 40 has a groove-like recessed shape on both the front and back sides of the thin-walled portion 97, and the provision of the thin-walled portion 97 makes it difficult for an external force acting from the outer periphery side of the thin-walled portion 97 to be transmitted to the inner periphery side. This prevents deformation of the inner periphery of the bottom portion 40 due to the action of an external force and the resulting deformation of the insertion hole 46. The thin-walled portion 97 is formed, for example, by coining in the same manner as the thin-walled portion 110 described below. The diameter of the insertion hole 46 in the bottom portion 40 is set according to the outer diameter of the inner needle 26, and in the present embodiment, the diameter is made smaller to correspond to the inner needle 26 that is thinner than in the first embodiment.

[0102] The first side plate 94 has the same overall structure as the first side plate 42 of the first embodiment. The first side plate 94 has a structure in which a first needle tip protection portion 98 serving as a needle tip cover is integrally formed on the distal end side of the first main body portion 48. The first needle tip protection portion 98 includes a first needle tip cover portion 100 extending from the protruding distal end of the first stepped portion 58. The first needle tip cover portion 100 is composed of a first distal end protection piece 52 provided contiguous with the first stepped portion 58 and a first return piece 54 protruding from the distal end of the first distal end protection piece 52. The angle formed between the first return piece 54 and the first distal end protection piece 52 of this embodiment is larger than that of the first embodiment, being an obtuse angle greater than 90°.

[0103] A first needle tip restraining portion 102 is provided at the protruding tip of the first return piece 54. The first needle tip restraining portion 102 is a rectangular plate-shaped portion that protrudes from the first return piece 54 toward the needle base side, that is, to the right in Figure 24. The first needle tip restraining portion 102 is formed by bending, and is provided integrally and continuously with the first return piece 54.

[0104] On the sides of the first needle tip protection portion 98, side cover pieces 56, 56 are provided extending from the first tip protection piece 52. The side cover pieces 56 of this embodiment are provided with a length that reaches the first needle tip restraining portion 102, and have a larger width dimension in the left-right direction compared to the first embodiment. In this way, by providing the side cover pieces 56 with a length that reaches the first needle tip restraining portion 102 and a large width, it becomes difficult for the needle tip 30 to be exposed to the side.

[0105] The second side plate 96 has the same overall structure as the second side plate 44 of the first embodiment. The second side plate 96 has a structure in which a second needle tip protection portion 104 serving as a needle tip cover portion is integrally formed on the distal end side of the second main body portion 68. The second needle tip protection portion 104 includes a second needle tip cover portion 106 extending from the protruding distal end of the second stepped portion 76. The second needle tip cover portion 106 is composed of a second distal end protection piece 72 provided contiguous with the second stepped portion 76 and a second return piece 74 protruding from the distal end of the second distal end protection piece 72. The angle formed between the second return piece 74 and the second distal end protection piece 72 of this embodiment is larger than that of the first embodiment, and is an obtuse angle greater than 90°.

[0106] A second needle tip restraining portion 108 is provided at the protruding tip of the second return piece 74. The second needle tip restraining portion 108 is shaped like a rectangular plate and protrudes from the second return piece 74 toward the needle base side, that is, to the right in Figure 24. The second needle tip restraining portion 108 is formed by bending and is provided integrally and continuously with the second return piece 74.

[0107] 24 , which shows the shape of the needle tip protector 90 attached to the inner needle 26, the protruding tip (the end on the needle base side) of the first needle tip inhibiting part 102 is located closer to the tip than the second needle tip protecting part 104. The length dimension of the first needle tip inhibiting part 102 is longer than the length dimension of the second needle tip inhibiting part 108. It is desirable that the axial distance between the first needle tip inhibiting part 102 and the second needle tip protecting part 104 is shorter than the length dimension of the first needle tip inhibiting part 102.

[0108] In this embodiment, the first main body portion 48 of the first side plate portion 94 and the second main body portion 68 of the second side plate portion 96 each have a thin-walled portion 110 that extends linearly in the front-to-rear direction. The thin-walled portion 110 is formed by coining (light forging using a die), and the thin-walled portion 110 improves the deformation rigidity of the first and second main body portions 48, 68, preventing unintentional opening of the first and second side plate portions 94, 96 when the needle tip 30 is protected, as described below.

[0109] As shown in Fig. 20 , the needle tip protector 90 is attached to the inner needle 26. The inner needle 26 is inserted between the first side plate portion 94 and the second side plate portion 96, and the first and second return pieces 54, 74 and the first and second needle tip restraining portions 102, 108 contact the outer peripheral surface of the inner needle 26. As a result, the first side plate portion 94 and the second side plate portion 96 are displaced away from each other in the left-right direction, and a biasing force acts on the first side plate portion 94 and the second side plate portion 96 in a direction moving closer to each other. As shown in Fig. 23 , the first and second side cover pieces 62, 80 of this embodiment have a shorter distance between their opposing surfaces and are positioned closer to the inner needle 26 than in the first embodiment, thereby reducing the amount of movement of the inner needle 26 in the up-down direction.

[0110] 25 , the needle tip 30 of the inner needle 26 is covered and protected by the needle tip protector 90 which has moved toward the needle tip 30. That is, the first and second return pieces 54, 74 and the first and second needle tip restraining portions 102, 108 are released from contact with the inner needle 26, causing the first and second needle tip protecting portions 98, 104 to displace toward each other, and the first and second needle tip cover portions 100, 106 to move on an extension of the needle tip 30 side of the inner needle 26. As a result, the distal end side of the needle tip 30 is covered by the first and second needle tip cover portions 100, 106, and the needle tip 30 of the inner needle 26 is brought into a needle tip protected state by the needle tip protector 90. Furthermore, since the first needle tip restraining portion 102 is positioned on the tip side without being caught on the second needle tip cover portion 106, it does not hinder the first and second side plate portions 94, 96 from moving closer together.

[0111] 25, when the needle tip 30 is protected by the needle tip protector 90, the protruding tip of the second side cover piece 80 is pressed against the first main body 48 of the first side plate 94. Similarly, the protruding tip of the first side cover piece 62 is pressed against the second main body 68 of the second side plate 96. This increases the biasing force in the direction in which the first side plate 94 and the second side plate 96 approach each other, making it less likely that the first side plate 94 and the second side plate 96 will be displaced away from each other due to the action of an external force.

[0112] Furthermore, when the needle tip 30 is protected by the needle tip protector 90, the connection portion between the second return piece 74 and the second needle tip restraining portion 108 is pressed against the first tip protection piece 52. This regulates the relative amount of approaching displacement of the first and second needle tip protection portions 98, 104, and, for example, ensures a gap between the first and second stepped portions 58, 76 and the inner needle 26, making it less likely that the first and second needle tip protection portions 98, 104 will be pushed open by the inner needle 26.

[0113] 25, in the protected state of the needle tip 30, the side covering pieces 56 extend further toward the base end than the second needle tip cover part 106. As a result, the needle tip 30 covered by the second needle tip cover part 106 is positioned between the opposing surfaces of the side covering pieces 56, 56, and is prevented from being exposed to the outside. In particular, because the side covering pieces 56, 56 are provided to cover up to the connection part between the second return piece 74 and the second needle tip restraining part 108, even if the needle tip 30 moves along the second return piece 74 until it abuts against the second needle tip restraining part 108, the needle tip 30 is maintained in a state covered by the side covering pieces 56, 56 without being exposed to the side.

[0114] Incidentally, when the needle tip 30 is protected by the needle tip protector 90, it is conceivable that, as shown in Fig. 26 , the inner needle 26 moves relative to the needle tip protector 90, causing the needle tip 30 to come off the second needle tip cover part 106 and come into contact with the first needle tip cover part 100. In this state, if the needle tip 30 moves along the first return piece 54 toward the second side plate part 96 (upward in Fig. 26 ), there is a risk that the needle tip 30 will push aside the second side plate part 96 and come off toward the protruding tip of the first return piece 54. Therefore, in this embodiment, a first needle tip stopper part 102 is provided at the protruding tip of the first return piece 54, and the needle tip 30 that moves along the first return piece 54 is engaged with the first needle tip stopper part 102, thereby preventing the needle tip 30 from coming off toward the protruding tip of the first return piece 54. This keeps the needle tip 30 covered and protected by the first needle tip cover part 100, preventing accidental punctures and the like.

[0115] Furthermore, in this embodiment, a second needle tip stopper 108 is provided at the protruding tip of the second return piece 74, making it difficult for the needle tip 30 to come off the second needle tip cover part 106 toward the protruding tip of the second return piece 74. Therefore, even if the needle tip 30 of the inner needle 26 moves left and right relative to the needle tip protector 90, the protected state of the needle tip 30 is maintained.

[0116] The protruding dimension of the second needle tip inhibiting portion 108 is smaller than the protruding dimension of the first needle tip inhibiting portion 102. As a result, in the protected state of the needle tip 30 shown in Fig. 25, the needle tip 30 is unlikely to enter between the second needle tip inhibiting portion 108 and the first tip protective piece 52, and even if the needle tip 30 does enter between the second needle tip inhibiting portion 108 and the first tip protective piece 52, the inner needle 26 is unlikely to press the second needle tip inhibiting portion 108, resulting in a transition to the state of Fig. 26.

[0117] 2 of the first embodiment, the abutment angle of the needle tip covers 98, 104 (50, 70) at the abutment portions with the inner needle 26 in the state of being fitted onto the inner needle 26 is different from that in the first embodiment. In the first embodiment, the abutment portions with the inner needle 26 are the tip surfaces of the return pieces 54, 74 that approach the inner needle 26 from an oblique direction. On the other hand, in this embodiment, needle tip stoppers 102, 108 provided at the tips of the needle tip covers 98, 104 extend approximately parallel to the inner needle 26, and the surfaces of these needle tip stoppers 102, 108 are the abutment portions with the inner needle 26. As can be seen by comparing Figure 25 of this embodiment with Figure 16 of the first embodiment, when the needle tip 30 is protected by the needle tip protector 90 (10), in the first embodiment, the return pieces 54, 74 located at the very tip of the needle tip covering parts 50, 70 are inclined toward the needle hub but are directed in the direction in which the needle tip moves to expose itself (to the left in Figure 16 for the needle tip covering part 50, and to the right in Figure 16 for the needle tip covering part 70), and therefore do not form effective return parts. On the other hand, in this embodiment, the needle tip stop parts 102, 108 located at the very tip of the needle tip covering parts 98, 104 protrude in the opposite direction to the direction in which the needle tip moves to expose itself (to the left in Figure 25 for the needle tip covering part 98, and to the right in Figure 25 for the needle tip covering part 104), and therefore form effective return parts.

[0118] Figure 27 shows a portion of a needle assembly 122 equipped with a needle tip protector 120 according to a third embodiment of the present invention. As also shown in Figures 28 to 33, the needle tip protector 120 includes a bottom portion 124 located on the needle base side (left side in Figure 30) of the inner needle 26, and a first side plate portion 94 and a second side plate portion 96 extending from the bottom portion 124 toward the needle tip 30 side (right side in Figure 30). When housed in an outer needle hub 138 (described below) shown in Figure 27, the needle tip protector 120 of this embodiment is housed in an orientation rotated 90° around the central axis (needle axis) compared to the first and second embodiments. Therefore, in the following description, the up-down direction of the needle tip protector 120 corresponds to the left-right direction of the needle tip protector 90, and the left-right direction of the needle tip protector 120 corresponds to the up-down direction of the needle tip protector 90 of the second embodiment.

[0119] The bottom 124 has a generally rectangular flat plate shape similar to the bottom 40 of the second embodiment, with the first side plate 94 and the second side plate 96 integrally formed so as to rise from the upper and lower opposite sides toward the needle tip 30 (front side). The bottom 124 has an insertion hole 46 formed through the center in the plate thickness direction. The bottom 124 has protrusions 126 formed therein that protrude leftward or rightward from the opposite sides on both the left and right sides. Two protrusions 126 are formed on the left and right opposite sides of the bottom 124, spaced apart from each other in the up-down direction, for a total of four protrusions formed on both the left and right sides. It is sufficient that the protrusions 126 are provided on the left and right opposite sides, respectively, and the number and arrangement of the protrusions 126 on each of the left and right opposite sides is not particularly limited.

[0120] The needle tip protector 120 is a press-formed product. When manufactured by press working a metal plate, the metal plate is first cut at a portion other than the four protrusions 126, 126, 126, 126. This cutting (press cutting) from the metal plate at a position away from the protrusions 126 is performed from a flat metal plate before stress such as bending is applied, allowing for high-precision cutting without generating burrs or distortion. Next, each portion of the needle tip protector 120 is formed by bending while maintaining continuity with the metal plate at each protrusion 126. Then, the protrusions 126 are cut to manufacture the needle tip protector 120. Because the bending process is performed before cutting the protrusions 126, the cut portion of the protrusion 126 is more likely to generate burrs and have lower shape and dimensional accuracy than other cut portions cut before bending. In short, in this embodiment, the portions where burrs are generated or portions where machining accuracy is low when cutting from the raw metal plate are limited to the convex portions 126, thereby preventing burrs and improving machining accuracy in the cut portions outside the convex portions 126. Furthermore, because the portions where machining accuracy is low are limited to the convex portions 126, by performing post-processing such as chamfering or polishing on the convex portions 126 as necessary, it is possible to achieve high accuracy in size and shape throughout the cut portion while reducing the effort required for post-processing.

[0121] In manufacturing such a needle tip protector 120, it is desirable to perform press bending of the first and second side plate portions 94, 96, etc. while bending the bottom portion 124 into a bow shape that is convex forward toward the vertical center, with the portions other than the respective convex portions 126 separated from the raw metal plate. In this manner, by separating the respective convex portions 126 from the raw metal plate and releasing the curved deformation of the bottom portion 124, the inclination angle of the first and second side plate portions 94, 96 relative to the bottom portion 124 can be set to less than 90° without increasing the bending angle of the first and second side plate portions 94, 96 relative to the raw metal plate. This makes it easy to realize the shape of the needle tip protector 120 in the needle tip protection state described below. In this embodiment, the convex portions 126 are formed at both left and right ends, making it easy to bend the bottom portion 124 into a bow shape between the left and right convex portions 126, 126. The bottom portion 124 can be regarded as having a substantially flat plate shape even if it is slightly curved as a result of press bending while being curved into an arch shape as described above. The bottom portion 124 may also be formed into a plate shape that is actively curved by bending or the like.

[0122] As shown in Figures 28 to 30, a first relief portion 128 is formed at each end of the first side plate 94 in the left-right direction, i.e., the width direction, of the first side plate 94, at the connecting portion between the first tip protection piece 52, which is the base end portion of the first needle tip protection portion 98, and the first stepped portion 58. The first relief portion 128 is a notch-shaped portion (a curved concave notch in this embodiment) that opens outward in the left-right direction, and has an expanding shape whose front-to-back width increases outward in the left-to-right direction. Due to the formation of such a first relief portion 128, as shown in Figure 32, the outermost corner of the first needle tip protection portion 98, i.e., the left and right ends of the connecting portion between the first tip protection piece 52 and the first stepped portion 58, are curved in outline when viewed in the needle axis direction, compared to when the first relief portion 128, shown imaginarily by a two-dot chain line, is not present. In short, the continuous portion between the first tip protective piece 52 and the first stepped portion 58 in the first needle tip protective part 98 is constricted, making it narrow in the left-right direction. As a result, even if the continuous portion between the first tip protective piece 52 and the first stepped portion 58 comes into contact (interferes) with the inner circumferential surface of the outer needle hub 138, the interfering portion on the inner circumferential surface of the outer needle hub 138 is less likely to be scraped off by the needle tip protector 120. Even if the first needle tip protective part 98 comes into contact with the inner circumferential surface of the outer needle hub 138 at the portion where the first relief portion 128 is formed, the abutting portion is chamfered as viewed in the needle axial direction due to the formation of the first relief portion 128, which has a curved shape, so a wide contact surface can be ensured, and damage such as scratches is less likely to occur on the inner circumferential surface of the outer needle hub 138.

[0123] Similarly, second relief portions 130 are formed at both left and right ends of the connecting portion between the second tip protection piece 72, which is the base end portion of the second needle tip protection portion 104, and the second stepped portion 76, and the base end portion of the second needle tip protection portion 104 is narrowed in a constricted manner due to the formation of the notched second relief portions 130. As a result, the connecting portion between the second tip protection piece 72 including the second relief portion 130 and the second stepped portion 76 also exhibits the same effect as the connecting portion between the first tip protection piece 52 including the first relief portion 128 and the first stepped portion 58. The first relief portion 128 and the second relief portion 130 may have substantially the same shape and size, or may have different shapes and sizes. For example, the second relief portion 130 provided on the side of the shorter second side plate portion 96 may be smaller than the first relief portion 128 provided on the side of the longer first side plate portion 94.

[0124] In the needle tip protector 120 of this embodiment, the second needle tip protection part 104 of the second side plate part 96 is provided with side cover pieces 132 that cover the left and right sides of the second needle tip protection part 104, similar to the side cover pieces 56 of the first side plate part 94. As shown in Figures 28 and 31, the side cover pieces 132 extend from the second return piece 74 of the second needle tip protection part 104. Note that in the second needle tip protection part 104 of this embodiment, the length of the second tip protection piece 72 is shorter and the length of the second return piece 74 is longer than in the second embodiment.

[0125] A first restricting protrusion 134 serving as a restricting protrusion is formed on the first protruding piece 66 serving as a lateral restricting piece extending from the first side plate portion 94 to between the opposing first side plate portion 94 and the second side plate portion 96. As shown in Figures 28 to 31 , the first restricting protrusion 134 protrudes inward in the left-right direction toward the inner needle 26 on the front side of the first protruding piece 66. The first restricting protrusion 134 in this embodiment is formed integrally with the front end portion of the first protruding piece 66 by bending the front end portion of the first protruding piece 66 inward in the left-right direction and extending out. The protruding tip on the inner side in the left-right direction of the first restricting protrusion 134 is positioned close to but separated from the outer peripheral surface of the inner needle 26 in the left-right direction.

[0126] The second projecting piece 84, which serves as a lateral projecting piece extending from the second side plate portion 96 between the opposing first side plate portion 94 and second side plate portion 96, is formed with a second projecting portion 136, which serves as a projecting portion projecting toward the inner needle 26. The second projecting portion 136 differs from the first projecting piece 84 in that it is integrally formed with the front end portion of the second projecting piece 84 and projects in opposite directions to the left and right. The first projecting portion 134 and the second projecting portion 136 are located at positions separated from each other in the left-right direction in the state before the needle tip protector 120 is activated for needle tip protection as shown in Figures 28 to 33. It is desirable that the first and second restricting projections 134, 136 are integrally formed by bending as in this embodiment, but they may also be provided, for example, by partially thickening the tip portions of the first and second projecting pieces 66, 84 by padding or the like, or they may be attached as separate parts to the tip portions of the first and second projecting pieces 66, 84. Furthermore, in consideration of the positional restriction effect achieved by abutting against the inner needle 26, only one of such first and second restricting projections (134, 136) may be provided, and they do not necessarily have to be at the tip of each projecting piece 84. Furthermore, the specific formation position and shape of the side restricting piece that extends between the opposing first and second side plate portions 94, 96 and on which the projecting piece 84 is provided are not limited.

[0127] As shown in Figure 27 , the needle tip protector 120 is housed on the inner periphery of the outer needle hub 138 and is attached in an externally inserted state to the inner needle 26. As in the second embodiment, the needle tip protector 120 has the inner needle 26 inserted between the first and second needle tip protection portions 98, 104, such that the first and second side plate portions 94, 96 are spaced apart in opposing directions, and the first and second needle tip protection portions 98, 104 are pressed against the inner needle 26 by the elasticity of the first and second side plate portions 94, 96 and the bottom portion 124. As shown in Figures 34 and 35 , which will be described later, in this embodiment, the circumferential orientation of the needle tip protector 120 relative to the blade surface 32 of the inner needle 26 is rotated 90° from that in the first and second embodiments, and the blade surface 32 faces the second side plate portion 96. The orientation of the needle tip protector 120 in the circumferential direction relative to the inner needle 26 is not particularly limited.

[0128] The outer needle hub 138 of this embodiment is provided with an expanded diameter housing portion 140 whose inner circumference is partially enlarged, and first and second needle tip protection portions 98, 104, which are spaced apart by being fitted onto the inner needle 26, are housed in the expanded diameter housing portion 140. The maximum inner diameter dimension of the outer needle hub 138 at the portion where the expanded diameter housing portion 140 is formed is larger than the maximum outer diameter dimension of the first and second needle tip protection portions 98, 104 of the needle tip protector 120 fitted to the inner needle 26. The expanded diameter housing portion 140 has a maximum inner diameter dimension midway in the axial direction. The inner peripheral surface of the expanded diameter housing portion 140 is configured as a tapered surface that slopes toward the inner circumference as it moves away from the maximum inner diameter portion in the axial direction, and in this embodiment is a concave curved surface that opens to the inner circumference. In particular, the angle of inclination of the tapered surface of the inner circumferential surface of the expanded diameter accommodating section 140 is sufficiently small on the axially proximal side of the maximum inner diameter portion, and is smaller than the angle of inclination of the tapered surface on the axially distal side of the maximum inner diameter portion. This makes it easy to remove the outer needle hub 138 from the outer needle hub 138 by climbing over a locking protrusion 142, which will be described later, and toward the proximal side.

[0129] A locking protrusion 142 protruding from the inner circumferential surface is formed on the proximal end side (rear side) of the expanded diameter housing portion 140 of the outer needle hub 138. The locking protrusion 142 may be annular and provided continuously around the entire circumferential direction, or may be provided partially around the circumferential direction, or multiple locking protrusions 142 may be provided around the circumferential direction. The locking protrusion 142 may have a substantially constant cross-sectional shape around the circumferential direction, or the cross-sectional shape may vary around the circumferential direction. The minimum inner diameter of the outer needle hub 138 at the portion where the locking protrusion 142 is formed is smaller than the diameter through which the first and second needle tip protection portions 98, 104 of the needle tip protector 120 attached to the inner needle 26 can pass. As a result, when the inner needle 26 is withdrawn toward the proximal end, the needle tip protector 120 locked to the locking protrusion 142 at the first and second needle tip protection portions 98, 104 moves relative to the inner needle 26 toward the needle tip 30. Furthermore, the needle tip protector 120 in the needle tip protection state described below is able to pass through the inner circumference of the locking protrusion 142 because the first and second needle tip protection parts 98, 104 are close to each other. When inserting the needle tip protector 120 into the inner circumference of the outer needle hub 138, the second needle tip stopping part 108 is positioned on the blade surface 32, and the first and second needle tip protection parts 98, 104 are inserted in a state where they are close to each other in the vertical direction, so that the first and second needle tip protection parts 98, 104 of the needle tip protector 120 attached to the inner needle 26 can be inserted further distally than the locking protrusion 142.

[0130] The first and second needle tip protection parts 98, 104 of the needle tip protector 120 have a reduced maximum outer diameter due to the formation of the first and second relief parts 128, 130, making them easier to insert into the outer needle hub 138. Furthermore, even if the first and second needle tip protection parts 98, 104 come into contact with the inner circumferential surface of the outer needle hub 138 at the portions where the first and second relief parts 128, 130 are formed when the needle tip protector 120 is inserted into the outer needle hub 138, the maximum outer diameter portions of the first and second needle tip protection parts 98, 104 have a chamfered shape due to the formation of the first and second relief parts 128, 130, so the contact pressure is reduced and damage to the inner circumferential surface of the outer needle hub 138 is prevented.

[0131] Because the bottom 124 of the needle tip protector 120 protrudes furthest outward in the left-right direction at the portion where the convex portion 126 is formed, it is likely to come into contact with the inner periphery of the outer needle hub 138 at the convex portion 126. Therefore, by performing post-processing such as chamfering on the convex portion 126, it is possible to more easily prevent damage to the outer needle hub 138 due to contact with the bottom 124 than when post-processing is performed on the entire left and right edges of the bottom 124.

[0132] When the inner needle 26 is pulled out toward the proximal end relative to the outer needle hub 138, as shown in Figures 34 and 35 , the needle tip protector 120 moves toward the needle tip 30 of the inner needle 26 and accommodates and protects the needle tip 30 of the inner needle 26. This prevents the needle tip 30 of the inner needle 26 from being exposed after use, preventing accidental touching of the needle tip 30 and ensuring safety. Note that with regard to the operation and protective aspects of the needle tip protector 120 when protecting the needle tip 30, which are substantially similar to those in the second embodiment, a description will be omitted.

[0133] The needle tip protector 120 of this embodiment is not only provided with side cover pieces 56 on the first needle tip protection part 98, but also with side cover pieces 132 on the second needle tip protection part 104. Therefore, even if the side cover pieces 56 of the first needle tip protection part 98 are moved to positions away from the top and bottom sides of the second needle tip protection part 104, the needle tip 30 is unlikely to be exposed to the left and right sides from the second needle tip protection part 104, and more reliable protection of the needle tip 30 is achieved.

[0134] When the needle tip protector 120 protects the needle tip 30, the first and second side plate portions 94, 96 approach each other, and as shown in Figure 35, the first and second regulating projections 134, 136 provided on the first and second projecting pieces 66, 84 are positioned close to each other at a predetermined distance on both the left and right sides of the inner needle 26. As a result, even if the inner needle 26 moves to a position that is vertically outwardly deviated from the first and second side cover pieces 62, 80, the left-right tilting of the inner needle 26 is quickly restricted at an early stage of tilting, when the tilt angle is small, by abutting against the first and second regulating projections 134, 136. Therefore, exposure of the needle tip 30 to the left and right sides is more reliably prevented.

[0135] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific description. For example, the first and second protruding pieces 66, 84 are not essential, and either one may be provided, or neither may be provided. Furthermore, the first and second protruding pieces 66, 84 are preferably long in length to effectively prevent, for example, the widthwise ends of the first and second side plate portions 42, 44 from being pressed and forcibly releasing the needle tip protection state. However, the length of the first and second protruding pieces 66, 84 may be shorter than that of the first and second side cover pieces 62, 80.

[0136] The specific structures of the first and second needle tip protection parts 50, 70 are not particularly limited. That is, the first needle tip protection part 50 in the above embodiment has a structure including a first tip protection piece 52 and a first return piece 54, each of which has an inclined shape. However, for example, a plate-shaped first needle tip protection part may be provided at the tip of the first main body part 48, protruding toward the inner needle 26 substantially perpendicular to the needle axial direction. In this case, when the needle tip protector is attached to the inner needle 26, the protruding tip of the first needle tip protection part abuts the outer peripheral surface of the inner needle 26, and when the inner needle 26 is withdrawn, the first needle tip protection part covers the tip side of the inner needle 26, thereby protecting the needle tip 30. Note that a similar structure can also be adopted for the second needle tip protection part.

[0137] It is desirable that the center in the width direction of the first side plate portion 42 at the portion where the first side cover piece 62 and the first protruding piece 66 are formed, and the center in the width direction of the second side plate portion 44 at the portion where the second side cover piece 80 and the second protruding piece 84 are formed, be biased toward the opposite side of each side cover piece 62, 80, but the center in the width direction of the first side plate portion 42 and the center in the width direction of the second side plate portion 44 may also be set at positions that are approximately aligned with each other in the width direction.

[0138] In the first embodiment, the first and second side cover pieces 62, 80 were provided in first and second notched recesses 64, 82 that opened at the side ends of the first and second side plate portions 42, 44 in the plate width direction, but the first and second recesses 64, 82 are not essential.In addition, in the embodiment relating to the sixth aspect, at least one of the first and second recesses 64, 82 is provided, and at least one of the first and second side cover pieces 62, 80 protrudes from the first and second recesses 64, 82.

[0139] The inner surface shape of the first and second notches 60, 78 is preferably a curved surface with the deepest part at the center of the width direction as shown in the first embodiment, but may also extend in the width direction with a substantially constant depth dimension, or may have a linear shape in which the depth dimension increases from both sides of the width direction toward the center of the width direction at a substantially constant rate of change.

[0140] In the first embodiment, an example is shown in which notches (first and second notches 60, 78) are formed in both the first and second side plate portions 42, 44, but it is also possible to provide a notch in only one of the first and second side plate portions 42, 44, or in some cases notches are provided in both the first and second side plate portions 42, 44.

[0141] In the first embodiment, an example was shown in which, when the inner needle 26 is pulled out from the outer needle 18, the abutment between the first and second side plate portions 42, 44 (first and second return pieces 54, 74) of the needle tip protector 10 and the inner needle 26 is released, causing the first and second side plate portions 42, 44 to transition to the needle tip protecting state due to an elastic restoring force (spring force). However, the transition of the needle tip protector 10 to the needle tip protecting state is not necessarily limited to deformation based on the elastic restoring force of the needle tip protector 10. Specifically, for example, a ring member may be disposed on the inner circumference of the outer needle hub 20 closer to the proximal end than the needle tip protector 10, and the needle tip protector 10 may be moved toward the proximal end by engaging with the large diameter portion 88 of the inner needle 26 and inserted into the ring member, causing the first and second side plate portions 42, 44 to approach each other by the ring member, thereby transitioning the needle tip protector to the needle tip protecting state. In this case, the ring member is removable from the outer needle hub 20 while being fitted onto the needle tip protector 10, and maintains the needle tip protector 10 in a needle tip protection state.

[0142] In the fifth or sixth aspect, the side cover piece may be provided on only one side of the puncture needle in the plate width direction. Also, in the fifth or sixth aspect, for example, the pair of side cover pieces may be provided on both end edges in the plate width direction of either the first side plate portion or the second side plate portion.

[0143] In the second embodiment, an example is shown in which a needle tip restraining portion is provided on both the first needle tip cover portion 100 and the second needle tip cover portion 106, but the needle tip restraining portion may be provided on only one of the first needle tip cover portion 100 and the second needle tip cover portion 106.

[0144] The present invention also includes a thirteenth aspect of a needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, and that comprises a first side plate portion and a second side plate portion that each extend from a bottom portion located on the base side of the puncture needle toward the needle tip of the puncture needle, and a needle tip cover portion that covers the needle tip is formed by the tip portions of the first side plate portion and the second side plate portion coming closer to each other, and a notch extending in the plate width direction is provided in the tip edge portion of at least one of the first side plate portion and the second side plate portion, and when attached to the puncture needle, the puncture needle fits into the notch and is positioned therein.

[0145] That is, in the needle tip protector described in the above-mentioned Patent Document 1, a groove extending in the needle axial direction is formed, and the puncture needle is configured to abut against the bottom of the groove in order to prevent lateral positional deviation relative to the puncture needle when attached to the puncture needle or when the puncture needle is being withdrawn. As a result, the abutment force and restraint force of the needle tip protector against the puncture needle become too large, and there is a risk that the operating feel may be impaired due to frictional resistance or snagging, particularly when the puncture needle is being withdrawn.

[0146] Therefore, according to the needle tip protector constructed in accordance with the thirteenth aspect, by providing a notch extending in the plate width direction at the tip edge of at least one of the first side plate portion and the second side plate portion, wobbling of the needle tip protector when attached to the puncture needle is suppressed, and stability can be improved by the guiding action even when moving toward the needle tip. In particular, with grooves extending in the needle axial direction as described in Patent Document 1, there are concerns about problems such as frictional resistance when the puncture needle moves and getting caught when tilting the puncture needle, but by providing a notch extending in the plate width direction of the side plate portion, such problems can be avoided.

[0147] The structures described in the first to thirteenth aspects can also be adopted by combining two or more appropriately selected structures.

[0148] The needle tip protector according to the present invention can also be applied to a needle assembly with a hemostatic valve in which the inner cavity of the outer needle hub is blocked by the hemostatic valve after the puncture needle is withdrawn.

[0149] REFERENCE SIGNS LIST 10 Needle tip protector (first embodiment) 12 Needle assembly 14 Outer needle unit 16 Inner needle unit 18 Outer needle 20 Outer needle hub 22 Crimping pin 23 Threaded portion 24 Locking step portion 26 Inner needle (puncture needle) 28 Inner needle hub 30 Needle tip 32 Blade surface 34 Connecting portion 36 Filter cap 38 Filter 40 Bottom portion 42 First side plate portion 44 Second side plate portion 46 Insertion hole 48 First main body portion 50 First needle tip protection portion (needle tip covering portion) 52 First tip protection piece 54 First return piece 56 Side covering piece 58 First step-shaped portion 60 First notch (notch) 62 First side cover piece (side cover piece) 64 First concave portion (concave portion) 66 First protruding piece (protruding piece) 68 Second main body portion 70 Second needle tip protection portion (needle tip covering portion) 72 Second tip protection piece 74 Second return piece 76 Second step-shaped portion 78 Second notch (notch) 80 Second side cover piece (side cover piece) 82 Second concave portion (concave portion) 84 Second protruding piece (protruding piece) 86 Molding space 88 Large diameter portion 90 Needle tip protector (second embodiment) 92 Needle assembly 94 First side plate portion 96 Second side plate portion 97 Thin-walled portion (stress transmission suppressing portion) 98 First needle tip protection portion (needle tip covering portion) 100 First needle tip cover portion (needle tip covering portion) 102 First needle tip stopping portion (needle tip stopping portion) 104 Second needle tip protection portion (needle tip covering portion) 106 Second needle tip cover portion (needle tip cover portion) 108 Second needle tip restraining portion (needle tip restraining portion) 110 Thin portion 120 Needle tip protector (third embodiment) 122 Needle assembly 124 Bottom portion 126 Convex portion 128 First relief portion (relief portion) 130 Second relief portion (relief portion) 132 Side cover piece 134 First restricting protrusion (restricting protrusion) 136 Second restricting protrusion (restricting protrusion) 138 Outer needle hub 140 Expanded diameter accommodating portion 142 Locking protrusion

Claims

1. A needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, comprising a first side plate and a second side plate that extend from a bottom located on the base side of the puncture needle toward the needle tip of the puncture needle, and are arranged opposite each other on either side of the puncture needle, and the first side plate and the second side plate have side cover pieces that protrude inward in the opposing direction at each widthwise edge that is opposite each other in the plate width direction, so that when attached to the puncture needle, the puncture needle is positioned between the side cover pieces of the first side plate and the second side plate.

2. A needle tip protector as set forth in claim 1, wherein the centers of the first and second side plate portions in the width direction are offset from each other toward opposite sides of the side cover pieces.

3. A needle tip protector as claimed in claim 1 or 2, wherein the first side plate portion and the second side plate portion have a protruding piece formed at one of the widthwise edge portions located on the opposite side of the side cover piece in the plate width direction, protruding inward in the opposing direction, and the protruding piece is located outside the side cover piece.

4. A needle tip protector as claimed in any one of claims 1 to 3, wherein the bottom is in the shape of a plate having an insertion hole for the puncture needle, the first side plate and the second side plate are integrally formed so as to rise from both side edges of the bottom, and the side cover pieces are formed at a distance of 2.5 mm or more from the base ends of the first side plate and the second side plate, so that a molding space that is open on both sides in the plate width direction is provided on the bottom between the opposing faces of the base end portions of the first side plate and the second side plate.

5. A needle tip protector as described in claim 1 or 2, wherein in a needle tip protection state in which the first side plate portion and the second side plate portion are close to each other to prevent exposure of the needle tip, the protruding tip of each of the side cover pieces of the first side plate portion and the second side plate portion is pressed against one of the first side plate portion and the second side plate portion.

6. A needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, comprising a first side plate and a second side plate that extend from a base located on the base side of the puncture needle toward the needle tip of the puncture needle, and are arranged opposite each other on either side of the puncture needle, and at least one of the first side plate and the second side plate has a center in the plate width direction that is offset from the needle axis of the puncture needle in the plate width direction, and is equipped with a side cover piece that protrudes inward in the opposing direction of the first side plate and the second side plate at the widthwise edge on the side closest to the puncture needle.

7. A needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, comprising a first side plate portion and a second side plate portion that each extend from a bottom portion located on the needle base side of the puncture needle toward the needle tip side of the puncture needle, at least one of the first side plate portion and the second side plate portion having a notched recessed portion that opens to a side end portion in the plate width direction, and a side cover piece that protrudes inward from the recessed portion and is located on the side of the puncture needle.

8. A needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, comprising a first side plate portion and a second side plate portion that each extend from a bottom portion located on the needle base side of the puncture needle toward the needle tip side of the puncture needle, a needle tip cover portion that protrudes toward the puncture needle is provided at the tip portion of at least one of the first side plate portion and the second side plate portion, and a needle tip stop portion that protrudes toward the needle base side is provided at the protruding tip of the needle tip cover portion.

9. A needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent the needle tip from being exposed, comprising a first side plate portion and a second side plate portion that extend from a bottom portion located on the needle base side of the puncture needle toward the needle tip of the puncture needle, and are arranged opposite each other on both sides of the puncture needle, and a side restriction piece is provided that extends between the opposing first side plate portion and second side plate portion, and a restriction protrusion is provided on the side restriction piece that protrudes toward the puncture needle.

10. A needle tip protector according to claim 9, wherein the restricting projection is provided at the end of the side restricting piece on the needle tip side.

11. A needle tip protector as described in claim 9 or 10, wherein the lateral regulating piece protrudes inward from the first side plate portion or the second side plate portion in the opposing direction of the first side plate portion and the second side plate portion.

12. A press-molded needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, wherein a first side plate and a second side plate are bent by bending from a bottom located on the needle base side of the puncture needle, and each side plate extends toward the needle tip of the puncture needle and faces each other, the bottom is shaped like a plate having an insertion hole for the puncture needle, the first side plate and the second side plate are integrally formed so as to rise from both side edges of the bottom, and the bottom has convex portions formed that protrude outward in the plate width direction of the first side plate and the second side plate.

13. A needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent exposure of the needle tip, comprising a first side plate and a second side plate that extend from a bottom located on the base side of the puncture needle toward the tip side of the puncture needle, and are arranged opposite each other on either side of the puncture needle, and the tip portions of the first side plate and the second side plate come relatively close to each other to form a needle tip cover that covers the needle tip, and the needle tip cover protrudes outward at the base end that is on the base side of the puncture needle, and notched relief portions are formed on both sides in the plate width direction at the base end of the needle tip cover.

14. A needle tip protector that is attached to a puncture needle and moves toward the needle tip to prevent the needle tip from being exposed, comprising a first side plate and a second side plate that are opposed to each other and extend from a bottom located on the base side of the puncture needle toward the needle tip of the puncture needle, the bottom being plate-shaped with an insertion hole for the puncture needle, the first side plate and the second side plate being integrally formed so as to rise from both side edges of the bottom, and a thin-walled stress transmission suppression part formed on the bottom surrounding the insertion hole.

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