Method for manufacturing needle tip protector for winged needle, and needle tip protector for winged needle manufactured using same

Abstract

Provided are: a novel method for manufacturing a needle tip protector for a winged needle that makes it possible to prevent deformation upon demolding and improve stability of needle tip protection performance of the manufactured needle tip protector; and a needle tip protector for a winged needle manufactured using the method.　Provided is a method for manufacturing a needle tip protector 10 for a winged needle. The needle tip protector 10 includes a plurality of protective pieces 12 extending toward the distal end side with respect to a base part 24 continuous in the circumferential direction and arranged side by side in a tubular shape, and stores and protects a needle tip 50 of a winged needle 46 on the radially inner side of the plurality of protective pieces 12. The method comprises: a molding step for molding the needle tip protector 10 for the winged needle in a spread open state in the arrangement direction of the plurality of protective pieces 12; and a demolding step for advancing demolding of the protective pieces 12 from a mold 62 for molding while maintaining the protective pieces 12 positioned in the circumferential direction with respect to the mold 62 for molding by positioning pins 78 inserted into the protective pieces 12, when the protective pieces 12 are demolded from the mold 62 for molding.

Description

Method for manufacturing a needle tip protector for a winged needle and a needle tip protector for a winged needle manufactured using the same

[0001] The present invention relates to a method for manufacturing a needle tip protector for a winged needle that protects the needle tip of a winged needle used for dialysis, blood sampling, etc. after use, and a needle tip protector for a winged needle manufactured using the same.

[0002] Conventionally, in order to avoid accidental punctures after removing a winged needle used for dialysis, blood sampling, etc., a needle tip protector for a winged needle has been proposed. The needle tip protector for a winged needle includes, for example, a plurality of protective pieces arranged in a cylindrical shape, and the needle tip of the winged needle is accommodated inside the protective pieces, so that the needle tip of the winged needle is protected by the needle tip protector. Such a needle tip protector is configured such that the wing portion of the winged needle is inserted into a slit between the circumferential directions of the protective pieces, allowing the winged needle to move toward the proximal end side with respect to the needle tip protector, and enabling the needle tip of the winged needle to be accommodated in the needle tip protector.

[0003] Japanese Patent No. 4029851

[0004] By the way, when manufacturing a cylindrical needle tip protector, for example, a semi-cylindrical molded product obtained by dividing the needle tip protector in half in the circumferential direction may be molded, and two semi-cylindrical molded products may be combined face-to-face to form a cylindrical needle tip protector.

[0005] However, a needle tip protector having a plurality of protective pieces is likely to have problems such as the protective pieces being plastically deformed when removed from the molding die during demolding, and there has been a problem that the needle tip protection performance is not stable.

[0006] The problem to be solved by the present invention is to provide a novel method for manufacturing a needle tip protector for a winged needle that can prevent deformation during demolding and improve the stability of the needle tip protection performance in the manufactured needle tip protector, and a needle tip protector for a winged needle manufactured using the same.

[0007] The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is illustrative and can be combined with others as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

[0008] The first embodiment is a method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip side are arranged in a cylindrical shape relative to a circumferentially continuous base portion, and the needle tip of the winged needle is housed and protected on the inner circumference side of the plurality of protective pieces, comprising a molding step of molding the needle tip protector for the winged needle in an unfolded state in the direction of the arrangement of the protective pieces, and a release step of releasing the protective pieces from the molding die while maintaining the protective pieces in a circumferential position relative to the molding die by positioning pins inserted into the protective pieces.

[0009] According to the manufacturing method for a needle tip protector for winged needles according to this embodiment, the release of the protective piece from the molding die proceeds in a circumferential positioning state in which relative displacement of the protective piece with respect to the molding die is prevented, thereby stably transmitting the force that pushes the protective piece out of the molding die to the protective piece. This suppresses the application of stress to unintended parts or directions on the protective piece, and reduces the occurrence of deformation of the protective piece during release, which can widen the slit between the protective pieces. Since the risk of deformation of the protective piece is reduced and the occurrence of the needle tip being exposed through the slit is suppressed, the needle tip protection performance of the needle tip protector manufactured by the manufacturing method according to this embodiment is stabilized.

[0010] Furthermore, a mold release process can be easily and stably implemented in which the protective piece is positioned circumferentially by a positioning pin inserted into the protective piece during the molding process.

[0011] A second embodiment is a method for manufacturing a needle tip protector for a winged needle as described in the first embodiment, wherein in the molding step, the protective piece is molded with the positioning pin inserted within a range of 1 / 2 of the length of the protective piece from the tip.

[0012] In the manufacturing method for a needle tip protector for winged needles according to this embodiment, the tip side of the protective piece, which is prone to misalignment with respect to the molding die during demolding, is positioned by a positioning pin. Since the tip side of the protective piece is a free end, it is prone to deformation due to its low resistance to external forces. However, according to this embodiment, deformation of the protective piece can be effectively suppressed, and the protective piece can be stably demolded from the molding die. Therefore, in a needle tip protector manufactured by the manufacturing method according to this embodiment, for example, the widening of the slit between the protective pieces due to deformation of the protective piece can be suppressed, thereby preventing exposure of the needle tip through the slit and thus stabilizing the needle tip protection performance.

[0013] A third aspect is a method for manufacturing a needle tip protector for a winged needle as described in the first or second aspect, wherein in the molding step, a plurality of protective pieces adjacent in the circumferential direction on both sides of a slit formed by fin-shaped protrusions protruding from the molding die are simultaneously molded, and in the demolding step, the plurality of protective pieces are pushed out of the molding die at multiple locations along the length of each protective piece to demold them.

[0014] According to the manufacturing method for a needle tip protector for winged needles according to this embodiment, the multiple protective pieces formed on both sides of the fin-shaped protrusion are extruded from the molding die at multiple points along the length, thereby distributing the force required to release the multiple elongated protective pieces. This reduces the risk of deformation of the protective pieces due to the input during release, thus stabilizing the needle tip protection performance in the needle tip protector manufactured by the manufacturing method according to this embodiment. Furthermore, since the length of the portion of the protective piece that is not extruded during release is shortened, release defects in the unextruded portion are less likely to occur, and unintended deformation of the protective piece due to release defects is prevented.

[0015] The fourth aspect is a method for manufacturing a needle tip protector for a winged needle as described in any one of the first to third aspects, wherein in the demolding step in which a protective piece ejector provided in the molding die strikes the protective piece multiple times against the protective piece to release the protective piece from the molding die, the initial speed of the first ejection operation of the protective piece ejector is set to be lower than the initial speed of at least one other ejection operation.

[0016] According to the manufacturing method for a needle tip protector for winged needles according to this embodiment, the force exerted on the protective piece from the protective piece ejector during the initial ejection operation of the protective piece ejector is suppressed, thereby reducing the risk of deformation of the protective piece. That is, during the initial ejection operation of the protective piece ejector, the resistance force of the protective piece to the external force is smallest, and if the protective piece deforms in the ejection direction (release direction), it is prone to plastic deformation. During the initial ejection operation, the external force exerted from the protective piece ejector may cause the protective piece to deform in the direction in which it was pushed by the protective piece ejector. If deformation of the protective piece occurs, the gap (slit) between each protective piece may become larger than expected, increasing the risk that the needle tip housed on the inner circumference side of the protective piece will be exposed to the outside through the gap between the protective pieces. Therefore, by slowing down the initial speed of the protective piece ejector's ejection, the force exerted on the protective piece from the ejector during the first ejection is suppressed, reducing the risk of deformation of the protective piece. This stabilizes the needle tip protection performance in the needle tip protector manufactured by the manufacturing method according to this embodiment. Furthermore, by making the initial speed of at least one ejection operation faster than the initial speed of the first ejection operation, the protective piece that has adhered to the molding die can be reliably released from the molding die, thereby improving the stability of the release process.

[0017] The fifth aspect is a method for manufacturing a needle tip protector for a winged needle as described in any one of the first to fourth aspects, wherein in the molding step, a molding die is used in which the outer peripheral molding surface for forming the outer peripheral surface of the protective piece is an inclined surface that approaches the inner peripheral molding surface for forming the inner peripheral surface of the protective piece as it approaches the tip side, thereby molding the needle tip protector for the winged needle in an unfolded state in the direction in which the multiple protective pieces are arranged.

[0018] According to the manufacturing method for a needle tip protector for winged needles according to this embodiment, the protective piece formed between the outer circumferential molding surface and the inner circumferential molding surface has an inclined surface on the outer circumferential side that slopes inward toward the tip side. Therefore, due to thermal shrinkage after molding, the tip side is easily displaced toward the inward side. Consequently, the needle tip protector manufactured by the manufacturing method according to this embodiment has a smaller gap (slit) between adjacent protective pieces in the circumferential direction in the needle tip protector after molding, and an effective needle tip protection state can be achieved.

[0019] The sixth aspect is a method for manufacturing a needle tip protector for a winged needle described in any one of the first to fifth aspects, wherein in the molding step, the needle tip protector for the winged needle is molded in an unfolded state consisting of a plurality of divided parts interconnected by hinge-like portions in the direction of the arrangement of the protective pieces.

[0020] According to the method for manufacturing a needle tip protector for winged needles according to this embodiment, multiple segmented bodies connected by a hinge-like portion can be integrally molded, thereby simplifying manufacturing and improving the efficiency of management and transportation by reducing the number of parts.

[0021] The seventh aspect is a method for manufacturing a needle tip protector for a winged needle described in any one of the first to fifth aspects, wherein in the molding step, the needle tip protector for the winged needle is molded in an unfolded state consisting of a plurality of divided parts separated in the direction of the arrangement of the protective pieces.

[0022] According to the manufacturing method for a needle tip protector for a winged needle in this embodiment, since the divided body is divided into multiple parts, it is possible to miniaturize the molding die for each divided body.

[0023] The eighth aspect is a method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip side from a circumferentially continuous base portion are arranged in a cylindrical shape, and the needle tip of the winged needle is housed and protected on the inner circumference side of the plurality of protective pieces, comprising: a molding step of molding a segmented body having the plurality of protective pieces provided adjacent to each other in the circumferential direction on both sides of a fin-shaped projection of a molding die, thereby forming a positioning step in the intermediate portion of the protective piece; a demolding step of releasing the segmented body from the molding die by abutting a protective piece ejector provided on the molding die against the protective piece while maintaining the protective piece in a circumferential position relative to the molding die by the engagement of the positioning step of the protective piece with the molding die; and a connecting step of connecting a plurality of the segmented bodies in the circumferential direction to constitute a cylindrical needle tip protector for the winged needle.

[0024] According to the manufacturing method for a needle tip protector for winged needles in this embodiment, the protective piece is released from the mold while maintaining its circumferential position relative to the molding die by the engagement of the positioning step portion of the protective piece with the molding die, thereby making deformation such as twisting of the protective piece less likely to occur. In particular, when the protective piece ejector is used to release the protective piece by abutting it against the protective piece, there is a concern that the protective piece may deform due to the force applied to it by the protective piece ejector. Deformation of the protective piece leads to a widening of the slit width between the protective pieces, which poses a risk of needle tip exposure after the winged needle is housed. However, by releasing the protective piece while obtaining the positioning effect of the positioning step portion, deformation of the protective piece can be suppressed, and the risk of needle tip exposure after the winged needle is housed can be reduced.

[0025] Furthermore, the divided parts can be released from the mold while connected via hinges, or they can be released independently of each other. Specifically, when connecting multiple divided parts that are linked together by hinges, in the connecting process, each divided part is rotated around the hinge as an axis to overlap and connect them. When connecting divided parts that have been released independently of each other, in the connecting process, for example, two divided parts are overlapped and connected.

[0026] The ninth aspect is a method for manufacturing a needle tip protector for a winged needle as described in the eighth aspect, wherein in the release step, a plurality of protective piece ejectors are abutted against a plurality of locations in the longitudinal direction of each protective piece.

[0027] According to the manufacturing method for a needle tip protector for a winged needle according to this embodiment, since the protective piece ejector abuts the protective piece at multiple points along the length of the protective piece, problems such as twisting or breaking of the protective piece due to abutting by the protective piece ejector are more easily avoided.

[0028] The tenth aspect is a method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip side from a circumferentially continuous base portion are arranged in a cylindrical shape, and the needle tip of the winged needle is housed and protected on the inner circumference side of the plurality of protective pieces, comprising a molding step of molding the needle tip protector for the winged needle in an unfolded state in the direction of the arrangement of the protective pieces, and a demolding step of repeatedly striking the protective piece ejector provided in the molding die against the protective piece to release the protective piece from the molding die, wherein the initial speed of the first ejection operation of the protective piece ejector is set to be lower than the initial speed of at least one other ejection operation.

[0029] According to the manufacturing method for a needle tip protector for winged needles according to this embodiment, the force exerted on the protective piece from the protective piece ejector during the initial ejection operation of the protective piece ejector is suppressed, thereby reducing the risk of deformation of the protective piece. That is, during the initial ejection operation of the protective piece ejector, the resistance force of the protective piece to external forces is smallest, and if the protective piece deforms, it is likely to undergo plastic deformation. During the initial ejection operation, the external force exerted from the protective piece ejector may cause the protective piece to deform in the direction in which it was pushed by the protective piece ejector. If deformation of the protective piece occurs, the gap (slit) between each protective piece may become larger than expected, increasing the risk that the needle tip housed on the inner circumference of the protective piece will be exposed to the outside through the gap between the protective pieces. Therefore, by slowing down the initial ejection speed of the protective piece ejector, the force exerted on the protective piece from the protective piece ejector during the initial ejection operation is suppressed, reducing the risk of deformation of the protective piece, and thus stabilizing the needle tip protection performance in needle tip protectors manufactured by the manufacturing method according to this embodiment. Furthermore, by setting the initial speed of at least one ejection operation to be faster than the initial speed of the first ejection operation, it is possible to reliably remove the protective piece that has adhered to the molding die from the molding die, thereby improving the stability of the mold release process.

[0030] The eleventh aspect is a method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip are arranged in a cylindrical shape relative to a circumferentially continuous base portion, and the needle tip of the winged needle is housed and protected on the inner circumference of the plurality of protective pieces, comprising: a molding step of molding the needle tip protector for the winged needle in an unfolded state in the direction of the arrangement of the protective pieces; a molding step of integrally molding the plurality of protective pieces that are formed on both sides of a fin-shaped projection protruding from a molding die and are adjacent to each other in the circumferential direction; and a demolding step of pushing out the plurality of protective pieces formed on both sides of the fin-shaped projection from the molding die by a protective piece ejector of the molding die at multiple locations in the longitudinal direction of each protective piece.

[0031] According to the manufacturing method for a needle tip protector for winged needles according to this embodiment, the multiple protective pieces formed on both sides of the fin-shaped protrusion are extruded from the molding die at multiple locations in the longitudinal direction. This allows the force required to demold the multiple elongated protective pieces to be distributed along the length of the protective pieces, thereby reducing the risk of deformation of the protective pieces due to the input during demolding. Therefore, the needle tip protection performance is stabilized in the needle tip protector manufactured by the manufacturing method according to this embodiment.

[0032] The twelfth aspect is a method for manufacturing a needle tip protector for a winged needle as described in the eleventh aspect, wherein in the mold release step in which a protective piece ejector provided in the molding die strikes the protective piece multiple times against the protective piece to release the protective piece from the molding die, the initial speed of the first ejection operation of the protective piece ejector is set to be lower than the initial speed of at least one other ejection operation.

[0033] According to the method for manufacturing a needle tip protector for winged needles in this embodiment, the risk of deformation of the protective piece can be reduced, thereby stabilizing the needle tip protection performance of the needle tip protector.

[0034] The thirteenth aspect is a method for manufacturing a needle tip protector for a winged needle as described in the eleventh or twelfth aspect, wherein in the demolding step, a tip ejector is brought into contact with the protective piece, and a base ejector, which is located on the base end side of the tip ejector and has a larger diameter than the tip ejector, is brought into contact with the protective piece, and the protective piece ejector, which includes the tip ejector and the base ejector, pushes the protective piece out of the molding die.

[0035] In the method for manufacturing a needle tip protector for winged needles according to this embodiment, the tip ejector closest to the tip of the protective piece ejector has a small diameter. As the protective piece approaches the tip, the resistance force when external force is applied decreases, making it more susceptible to deformation of the protective piece due to contact by the protective piece ejector. However, by having a small diameter tip ejector, deformation of the protective piece due to contact by the protective piece ejector is suppressed, and the needle tip protection function of the protective piece can be further stabilized.

[0036] The fourteenth aspect is a method for manufacturing a needle tip protector for a winged needle as described in any one of the eleventh to thirteenth aspects, wherein the molding die used in the molding step includes an inner mold for molding the inner circumferential surface of the protective piece and an outer mold for molding the outer circumferential surface of the protective piece, and the fin-shaped projection and the protective piece ejector are provided on either the inner mold or the outer mold.

[0037] According to the method for manufacturing a needle tip protector for winged needles according to this embodiment, it is possible to suppress situations in which the protective piece adheres to the fin-shaped protrusion and deforms the protective piece.

[0038] The fifteenth aspect is a method for manufacturing a needle tip protector for a winged needle as described in any one of the eleventh to fourteenth aspects, wherein the molding die used in the molding step includes an inner mold for molding the inner circumferential surface of the protective piece and an outer mold for molding the outer circumferential surface of the protective piece, and both the fin-shaped projection and the protective piece ejector are provided in the inner mold.

[0039] According to the method for manufacturing a needle tip protector for winged needles according to this embodiment, since both the fin-shaped projection and the protective piece ejector are provided in the inner mold, it is expected that the fin-shaped projection will position the protective piece after the outer mold is demolded, and the structure of the outer mold can be simplified.

[0040] The sixteenth aspect is a method for manufacturing a needle tip protector for a winged needle as described in any one of the eleventh to fifteenth aspects, wherein in the demolding step, the base portion is pushed out of the molding die by a pair of base ejectors on both outer sides in the width direction perpendicular to the demolding direction relative to the protective piece ejector.

[0041] According to the method for manufacturing a needle tip protector for winged needles according to this embodiment, by pushing out the base portion with a pair of base ejectors on both outer sides in the width direction of the protective piece ejector that pushes out the protective piece, twisting of the molded product due to the action of moment can be suppressed, thereby achieving more stable demolding.

[0042] In the sixteenth embodiment, for example, the molding die may be provided with a base molding section for molding the base portion in a continuously unfolded state with hinges, and the base molding section may be provided with one of the pair of base ejectors at a position close to and far from the hinge molding section for molding the hinges in the circumferential direction. With this configuration, when the divided parts of the needle tip protector molded in an unfolded state are connected by hinges and formed as a single unit, the side close to the hinge and the side far from the hinge are pushed out by the base ejectors, respectively, making it less likely for unintended deformation of the hinge to occur during demolding. The hinge is sometimes made thin so that it can be easily deformed when the divided parts are combined facing each other after molding to form a cylindrical needle tip protector, and is therefore prone to unintended deformation during demolding, but according to this embodiment, such unintended deformation of the hinge can be prevented. As a result, the shape of the needle tip protector is stabilized, and variations in shape, such as changes in the width of the slits between protective pieces, can be suppressed.

[0043] The seventeenth aspect is a method for manufacturing a needle tip protector for a winged needle as described in the sixteenth aspect, wherein in the demolding step, the protective piece ejector is brought into contact with the first extrusion surface of the protective piece which spreads inclined with respect to the demolding direction from the molding die, and the base ejector is brought into contact with the second extrusion surface of the base portion which spreads perpendicular to the demolding direction from the molding die, thereby pushing the protective piece and the base portion out from the molding die.

[0044] According to the manufacturing method of the needle tip protector for the winged needle according to this aspect, by extruding the base portion, which is easier to increase rigidity compared to the protection piece, with the base ejector, the mold release from the molding die can be stabilized. For example, when the plurality of protection pieces arranged in a cylindrical shape are formed into a curved plate shape or the like, and the first extrusion surface, which is the contact surface of the protection piece ejector, is inclined with respect to the mold release direction, the surface of the base portion against which the base ejector abuts is set as the second extrusion surface orthogonal to the mold release direction, which is the direction in which the base ejector abuts against the base portion. Thus, more stable mold release of the molded product (the needle tip protector in the deployed state) by the base ejector can be realized. In addition, by extruding the base portion with a pair of base ejectors on both outer sides in the width direction of the protection piece rather than the protection piece ejector that extrudes the protection piece, more stable mold release can be realized.

[0045] The eighteenth aspect is a needle tip protector for a winged needle, which is manufactured by the manufacturing method of the needle tip protector for a winged needle according to any one of the first to seventeenth aspects.

[0046] According to the needle tip protector for a winged needle according to this aspect, due to the effects achieved by the manufacturing method described in any one of the first to seventeenth aspects, a needle tip protector for a winged needle with excellent accuracy in shape, dimensions, etc. can be realized.

[0047] According to the present invention, at least one of the deformation events of the protection piece that can occur during mold release can be solved, and the stability of the needle tip protection performance in the manufactured needle tip protector can be improved.

[0048] Perspective view showing the needle tip protector for a winged needle as a first embodiment of the present invention. Front view of the needle tip protector for the winged needle shown in FIG. 1. Perspective view showing the needle tip protector for the winged needle shown in FIG. 1 in a deployed state. Front view of the needle tip protector for the winged needle shown in FIG. 3. Front view showing the state of attachment of the needle tip protector for the winged needle shown in FIG. 1 to the winged needle. Front view showing the state of protecting the needle tip of the winged needle by the needle tip protector for the winged needle shown in FIG. 1. Front view showing the needle tip protector for the winged needle as another embodiment of the present invention in a deployed state. Cross-sectional view showing the mold for molding the needle tip protector for the winged needle shown in FIG. 7. Planar view of the inner mold constituting the mold shown in FIG. 8. Perspective view of the semi-cylindrical molding part constituting the inner mold shown in FIG. 9. Right side view of the semi-cylindrical molding part shown in FIG. 10. Perspective view of the semi-cylindrical molding part shown in FIG. 10. Right side view of the semi-cylindrical molding part shown in FIG. 11. Cross-sectional view showing the process of separating the molded product molded by the mold shown in FIG. 8 from the inner mold. Graph showing the speed of the ejector pin protruding operation in the mold separation process shown in FIG. 14

[0049] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0050] In FIGS. 1 and 2, a needle tip protector 10 for a winged needle (hereinafter, needle tip protector 10) according to a first embodiment of the present invention is shown. The needle tip protector 10 has a structure in which a plurality of protection pieces 12 are arranged side by side in a cylindrical shape, and the needle tip 50 of a winged needle 46, which will be described later, is to be accommodated and protected within the inner circumference of those protection pieces 12. In the following description, in principle, the tip side refers to the upper side in FIG. 2, which is the side of the needle tip 50 of the winged needle 46 to be described later, and the base end side refers to the lower side in FIG. 2, which is the side of the tube 60 of the winged needle 46 to be described later. Also, in principle, the axial direction refers to the central axis direction of the needle tip protector 10 formed in a cylindrical shape, and the circumferential direction refers to the circumferential direction of the needle tip protector 10. Note that the needle tip protector 10 is manufactured by the manufacturing method to be described later.

[0051] The needle tip protector 10 is cylindrical overall and, as shown in Figures 3 and 4, has a divided structure consisting of two divided bodies 14, 14 divided in half around each half, and these divided bodies 14, 14 are integrally connected at one end in the circumferential direction by a hinge-like portion 16. Each divided body 14 has a plurality of protective pieces 12, divided insertion portions that constitute a tube insertion portion 18, and columnar portions 32 formed between each protective piece 12 and the divided insertion portion. The two divided bodies 14, 14 are connected in a state where they are superimposed to form a cylindrical shape.

[0052] The hinge-like portion 16 connecting the divided bodies 14, 14 is provided on the tube insertion portion 18 that constitutes the base end of the needle tip protector 10. The tube insertion portion 18 is a cylindrical body having a cylindrical wall surface continuous in the circumferential direction, and is designed to be externally fitted onto the tube 60, which will be described later. The base end opening of the tube insertion portion 18 is approximately oval in shape, and its diameter in the short axis direction is approximately the same as the outer diameter of the tube 60, which will be described later. Multiple anti-slip protrusions 19 extending in the circumferential direction are formed protruding from the outer surface of the tube insertion portion 18, so that, for example, when pinching the tube insertion portion 18 with your fingertips and applying axial force, your fingertips are less likely to slip and it is easier to apply force.

[0053] Furthermore, the tube insertion portion 18 is provided with fixing means for holding the tube insertion portion 18 in a cylindrical shape at the portion radially opposite to the hinge-shaped portion 16. The circumferential ends of the divided bodies 14, 14 opposite to the hinge-shaped portion 16 are overlapped circumferentially and connected and fixed by the fixing means, thereby holding the tube insertion portion 18 in a cylindrical shape. Thus, the tube insertion portion 18 has a divided structure with circumferentially divided portions, with one circumferential end integrally connected by the hinge-shaped portion 16 and the other circumferential end connected and fixed by the fixing means. The fixing means of this embodiment is configured such that a pair of connecting hooks 20, 20, which protrude circumferentially outward from one segment 14 and have claws at their tips, are inserted into a pair of connecting holes 22, 22 provided in the other segment 14 and locked to the opening periphery of the connecting holes 22, and the portions of the one segment 14 and the other segment 14 located between the pair of connecting hooks 20, 20 are integrated by ultrasonic welding. In this way, it is possible to more reliably prevent the segment 14, 14 from unfolding again. The fixing means for connecting the circumferential ends of the segment 14, 14 is not limited to this, and for example, it may be configured by fitting the convex portion of one segment 14 into the concave portion of the other segment 14, or by locking only the connecting hooks 20, 20 without ultrasonic welding, or by ultrasonic welding only without locking by the connecting hooks 20, 20, or by connecting with an adhesive or the like. That is, each segment may be connected by adhesive, welding, or mechanical engagement.

[0054] The tip of the tube insertion portion 18 is a base portion 24. The base portion 24 is integrally formed on the proximal end side of the protective piece 12 and is provided continuously around the entire circumference. The base portion 24 has an outer circumferential surface with a substantially circular cross-section (a cross-section perpendicular to the axis) and an inner circumferential surface with a substantially rectangular cross-section having four corners 26, 26, 26, 26.

[0055] The inner circumferential surface of the tube insertion portion 18, closer to the base portion 24, is composed of four tube-holding surfaces 28, 28, 28, 28. The tube-holding surfaces 28 are substantially flat, and the inner circumferential surface of the tube insertion portion 18, composed of the four tube-holding surfaces 28, 28, 28, 28, has a substantially rectangular cross-section.

[0056] As shown in Figures 3 and 4, a tube-holding groove 30 is formed on the tube-holding surface 28 of the tube insertion portion 18. The tube-holding groove 30 is a groove-shaped recess that opens into the tube-holding surface 28 and extends in the axial direction, and is provided at the tip end of the tube-holding surface 28. In this embodiment, the inner surface of the tube-holding groove 30 is a curved surface having a substantially arc-shaped cross-section, but the shape of the inner surface of the tube-holding groove 30 is not particularly limited, and may be, for example, a surface having a polygonal cross-section composed of a combination of multiple planes.

[0057] The inner circumferential surface of the tube insertion portion 18 is configured such that the portion made up of the base portion 24 and the portion made up of the four tube holding surfaces 28, 28, 28, 28 are oriented at a 90-degree angle in the circumferential direction, and the corners 26 of the inner circumferential surface of the base portion 24 are positioned in the circumferential direction to be aligned with the circumferential center of the tube holding surface 28 in the axial direction. Furthermore, tube holding grooves 30 are provided on the base end side of each corner 26 of the inner circumferential surface of the base portion 24, and the inner surface of the tube holding grooves 30 is smoothly continuous with the inner circumferential surface of the base portion 24 without creating any steps.

[0058] The corners 26, 26, 26, 26 of the base portion 24 and the tube holding grooves 30, 30, 30, 30 are all positioned circumferentially offset from the dividing positions, which are the circumferential ends of the divided bodies 14, 14. In this embodiment, the circumferential ends of the divided bodies 14, 14 (the dividing positions of the tube insertion portions 18) are located approximately in the center between the corners 26, 26 on the inner circumferential surface of the base portion 24, which has a roughly rectangular cross-section, and the distance between the corners 26 and the dividing positions of the tube insertion portions 18 is made large.

[0059] Four columnar portions 32, 32, 32, 32 are provided at the corner portions 26, 26, 26, 26 of the inner circumferential surface of the base portion 24, corresponding to the circumferential portion in the circumferential direction, extending from the base portion 24 toward the tip. The columnar portions 32 are rod-shaped, extending linearly with a substantially constant cross-sectional shape. In this embodiment, the columnar portions 32 have a substantially octagonal cross-sectional shape, but the cross-sectional shape of the columnar portions 32 is not particularly limited and may be circular, for example.

[0060] A housing window portion 34 is formed between the columnar portions 32, 32 that are arranged adjacent to each other in the circumferential direction. As shown in Figures 1 to 4, the housing window portion 34 has a substantially rectangular opening shape and is provided extending radially through it, and is formed by being surrounded by the columnar portions 32, 32 on both sides in the circumferential direction, the base portion 24 on the base end side, and the protective piece 12 (described later) on the tip side. The needle tip protector 10 has four housing window portions 34, 34, 34, 34 which are substantially the same shape and size as each other and are provided substantially evenly in the circumferential direction, and the space between adjacent housing window portions 34, 34 in the circumferential direction is separated by the columnar portion 32. The base end side wall portion of the housing window portion 34 is made up of the base portion 24, and the tube insertion portion 18 is located closer to the base end than the housing window portion 34.

[0061] A protective piece 12 is provided at the tip of the columnar portion 32. The columnar portion 32 is rod-shaped with a short width dimension and extends in the axial direction, and its tip is connected to the long protective piece 12, forming an elongated portion together with the protective piece 12. The base end of the elongated portion is connected to the base portion 24, with the base end (root side) having a greater resistance to external forces and the tip end having a smaller resistance to external forces. The elongated portion has, for example, an axial dimension that is preferably four times or more, and more preferably five times or more, than the width dimension. The protective piece 12 is plate-shaped and curved in an arc in the circumferential direction, with a width dimension of about 1 / 4 of the circumference in the circumferential direction. The protective piece 12 has a tapered shape at the tip, becoming narrower in the circumferential direction towards the tip. The tip of the protective piece 12 is curved such that one end face in the circumferential direction is convex and the other end face in the circumferential direction is concave. In the protective piece 12, the part closer to the tip than the inclined portion 44 of the slit 38 (described later) has its circumferential center located on the extension of the columnar portion 32 toward the tip. The tip portion of the protective piece 12 is shaped to correspond to the curved portion 40 of the slit 38, but overall, its circumferential center is located on the extension of the columnar portion 32. In particular, the protective piece 12 has its circumferential center located on the extension of the columnar portion 32 between the inclined portion 44 and the curved portion 40, and further toward the tip than the curved portion 40. The protective piece 12 is provided further toward the tip than the columnar portion 32 that extends toward the tip from the base portion 24, and is provided extending toward the tip relative to the base portion 24.

[0062] Two protective pieces 12 are provided on each of the two divided bodies 14, 14, and in the entire needle tip protector 10, four protective pieces 12, 12, 12, 12 are arranged in a circumferential direction, and these four protective pieces 12, 12, 12, 12 form a cylindrical shape. More specifically, four curved plate-shaped protective pieces 12, 12, 12, 12 form a cylindrical shape. The axial dimension of the protective piece 12 is, for example, 5 cm or more. A columnar portion 32 extends from each protective piece 12 toward the base end, and the protective piece 12 and the tube insertion portion 18 are connected by the columnar portion 32. In this embodiment, the tube insertion portion 18, the columnar portion 32, and the protective piece 12 are integrally formed from synthetic resin or the like, but they may be formed as separate components and fixed to each other. The columnar portion 32 is located approximately in the center in the circumferential direction relative to the portion of the protective piece 12 that is located axially between the curved tip portion and the inclined portion 44 of the slit 38, which will be described later. The protective piece 12 and the columnar portion 32 constitute more than two-thirds of the entire needle tip protector 10 in the longitudinal direction of the needle tip protector 10.

[0063] A slit 38 is formed between adjacent protective pieces 12, 12 in the circumferential direction. The slit 38 extends continuously along the entire length of the protective piece 12, from the tip to the base. The tip of the slit 38 is open towards the tip between the protective pieces 12, 12. In this embodiment, the tip portion of the protective piece 12 is narrower in the circumferential direction toward the tip, and the slit 38 forms an expanding portion that expands circumferentially toward the tip. Furthermore, a part of the tip portion of the protective piece 12 is curved, so the tip portion of the slit 38 is a curved portion 40 that extends in a curved shape. The width dimension of the slit 38 is 1 mm or less in at least part of it. Specifically, for example, the width dimension is 1 mm or less on the tip side of the axial center of the slit 38, from the slit inlet portion, which is the base end of the expanding portion (the end on the narrower side of the expanding portion), to the slit exit portion that connects to the receiving window portion 34 described later. Preferably, for example, the width of the slit 38 is 1 mm or less in the portion excluding the wide portion formed by the inclined portion 44, which will be described later, from the slit inlet to the slit outlet. If the slit 38 does not have a wide portion formed by the inclined portion 44, preferably the width of the slit 38 is 1 mm or less along its entire length.

[0064] The base end of the slit 38 is connected to the receiving window portion 34. The receiving window portion 34 is wider than the base end of the slit 38. Preferably, as in this embodiment, the receiving window portion 34 is wider in the circumferential direction than the inclined portion 44, which will be described later and is partially wider in the slit 38. The width dimension of the receiving window portion 34 is preferably at least twice the width dimension of the base end exit of the slit 38, and more preferably at least three times.

[0065] The base end of the slit 38 is located circumferentially away from both ends of the housing window 34. Both ends of the protective piece 12 protrude outward from the columnar portion 32 in the circumferential direction, forming retaining portions 42. The slit 38 connects to the housing window 34 between the retaining portions 42, 42 of adjacent protective pieces 12, 12 in the circumferential direction. The wall portion of the housing window 34 at the tip is formed by the retaining portion 42 and is located closer to the base end than the protective piece 12. The base end of the slit 38 is located off-center from the circumferential center of the housing window 34. Therefore, the retaining portions 42, 42 located on both sides of the slit 38 in the circumferential direction have different circumferential protrusion dimensions from the columnar portion 32.

[0066] In this embodiment, the tip of the slit 38 is located at a circumferential position corresponding to the circumferential center of the receiving window 34. The base end of the slit 38 is located off-center in the circumferential direction because a circumferentially inclined portion 44 is provided in the middle of the slit 38. In short, the slit 38 is offset from each other in the circumferential direction on both sides in the longitudinal direction relative to the circumferential portion 44. Furthermore, each slit 38 has straight portions extending linearly in the axial direction from the circumferential portion 44 at both the tip and base ends of the circumferential portion 44. The circumferential portion 44 of the slit 38 is inclined circumferentially with respect to the axial direction, and in this embodiment, it extends linearly at a substantially constant inclination angle. The circumferential portion 44 is smoothly continuous on both sides of the slit 38 that are off-center in the axial direction. Therefore, no sharp corners are formed on the inner surface of the wall of the slit 38. Note that multiple circumferential portions 44 may be provided in the middle of the slit 38. The multiple inclined sections 44 may have different inclination angles. The inclined sections 44 are not limited to linear inclined shapes with a substantially constant inclination angle, but can also be, for example, curved inclined shapes with continuously changing inclination angles, or polylinear inclined shapes with continuously changing inclination angles.

[0067] The front-end wall surface of the receiving window portion 34, which is formed by the base end face of the protective piece 12 (retaining portion 42), is located on a plane perpendicular to the axis and not inclined with respect to the circumferential direction, or it is inclined toward the base end towards the base end exit of the slit 38. It is desirable that the front-end wall surface of the receiving window portion 34 is inclined toward the base end towards the base end exit of the slit 38 in the circumferential direction. This makes it easier to prevent the wing portion 54 that has entered the receiving window portion 34 through the slit 38 from coming out toward the front end through the slit 38, as will be described later.

[0068] As shown in Figure 5, the needle tip protector 10 is used attached to the winged needle 46. The winged needle 46 has a puncture needle 48. The puncture needle 48 is made of medical-grade stainless steel or the like and has a needle tip 50 at its end.

[0069] A needle hub 52 is fixed to the base end of the puncture needle 48. The needle hub 52 is cylindrical and fixed to the base end of the puncture needle 48. In addition, two wing portions 54, 54 that protrude outward from both sides of the needle hub 52 are integrally provided with the needle hub 52.

[0070] The wing portion 54 is plate-shaped and is provided in contact with the needle hub 52, which has a substantially circular cross-section. Therefore, the wing portion 54 is positioned offset in one direction in the radial direction of the needle hub 52 (the thickness direction of the wing portion 54) with respect to the central axis of the needle hub 52. The wing portion 54 comprises a connecting portion 56 that protrudes outward from the needle hub 52 and a wing body 58 that is provided continuously on the outside of the connecting portion 56.

[0071] The winged needle 46 is used, for example, during intravenous fluid administration or dialysis, where the puncture needle 48 is inserted into the patient's blood vessel. After use, the puncture needle 48 of the winged needle 46 is removed from the patient's blood vessel. When the puncture needle 48 is removed, as shown in Figure 6, the puncture needle 48 is housed and protected in the needle tip protector 10.

[0072] The wing portions 54 of the winged needle 46 approach the needle tip protector 10 axially from the tip side and are inserted into the slits 38 of the needle tip protector 10. The two wing portions 54, 54 are inserted into different slits 38, but for example, they may be inserted into slits 38, 38 on both radial sides, or into slits 38, 38 adjacent in the circumferential direction.

[0073] Since the tip of the protective piece 12 has a tapered shape, the wing portion 54 that contacts the tip of the protective piece 12 is smoothly guided to the slit entrance. The thickness of the wing portion 54 is greater than the width of the part of the slit 38 that is outside the inclined portion 44, and it moves towards the base end inside the slit 38 while pushing the slit 38 open. Furthermore, the slit 38 is pushed open even more when the wing portion 54 passes through the curved portion 40 provided at the tip of the slit 38.

[0074] The wing portion 54 that has passed through the slit 38 is inserted into the storage window portion 34. When the wing portion 54 is housed in the storage window portion 34, the lancet 48 is located on the inner circumference side of the protective pieces 12, 12, 12, 12, and is surrounded and protected by the protective pieces 12, 12, 12, 12, on almost its entire circumference. This prevents accidental contact with the tip 50 of the lancet 48 and makes the lancet 48 difficult to see from the outside after use.

[0075] As a needle tip protector for a winged needle according to the present invention, a needle tip protector 10' for a winged needle, as shown in Figure 7, can also be used. In the description of the needle tip protector 10', components and parts that are substantially the same as those of the needle tip protector 10 according to the first embodiment are denoted by the same reference numerals in the figure, and their description is omitted. Figure 7 shows the needle tip protector 10' in a circumferentially unfolded state, but, similar to the needle tip protector 10 of the first embodiment, a cylindrical needle tip protector 10' is formed by combining divided parts 14', 14' facing each other.

[0076] The protective piece 12' of the needle tip protector 10' extends with a substantially constant width dimension towards the base end from the curved portion 40, and the slit 38 between adjacent protective pieces 12', 12' does not have an inclined portion 44. The columnar portion 32' of the needle tip protector 10' extends from one end of the protective piece 12' in the circumferential direction toward the base end, and in one protective piece 12', the retaining portion 42 is provided only on one side in the circumferential direction relative to the columnar portion 32'. The needle tip protector 10' is constructed by combining two divided bodies 14', 14', similar to the needle tip protector 10 of the first embodiment, and these divided bodies 14', 14' are integrally connected by a hinge-like portion 16. The divided body 14' comprises two circumferentially adjacent protective pieces 12', 12' and columnar portions 32', 32'.

[0077] Incidentally, the resin needle tip protector 10' is manufactured using a molding die 62 as shown in Figure 8. Below, the manufacturing method of the needle tip protector 10' and the molding die 62 used for molding the needle tip protector 10' will be described. In this embodiment, the manufacturing method of the needle tip protector 10' using the molding die 62 will be described, but the structure of the molding die used for manufacturing the needle tip protector 10' is not limited to the structure of the molding die 62 described below. Note that the molding die 62 and a part thereof shown in Figures 8 to 13 are merely examples, and for example, the shape of the cavity 68, etc., can be appropriately changed according to the shape of the molded product, the needle tip protector. Therefore, although Figures 8 to 13 show the manufacturing method of the needle tip protector 10' and the molding die 62, the needle tip protector 10 according to the first embodiment can also be manufactured using a similar molding die with the shape of the cavity 68 appropriately changed, using the same manufacturing method as the needle tip protector 10', and the same effects can be obtained. In the following explanation, the release direction refers to the rightward direction in Figure 8. Also, the upper side in Figure 8 is considered the tip side, and the lower side is considered the base side.

[0078] The molding die 62 includes an inner mold 64 for molding the inner circumferential surface of the needle tip protector 10' and an outer mold 66 for molding the outer circumferential surface of the needle tip protector 10'. A cavity 68 is formed between the overlapping surfaces of the inner mold 64 and the outer mold 66 for integrally molding the divided parts 14', 14'. In this embodiment, the inner mold 64 is made of a single mold, but for example, the inner mold 64 may be made by combining multiple divided molds. Similarly, the outer mold 66 can also be made by combining multiple divided molds. The cavity 68 may only mold one of the divided parts 14'.

[0079] As shown in Figure 8, the inner mold 64 has an inner circumferential molding surface 69 that forms the wall surface of the cavity 68 and shapes the inner circumferential surface of the needle tip protector 10'. As shown in Figure 9, the inner mold 64 has a structure in which semi-cylindrical molding sections 70a and 70b, which shape each half-circumferential portion of the needle tip protector 10', are arranged side by side. The semi-cylindrical molding sections 70a and 70b are connected to each other on the molding side of the hinge-shaped section 16. The tip portions of the semi-cylindrical molding sections 70a and 70b are each provided with two protective piece molding surfaces 72 that shape the inner circumferential surface of the protective piece 12'. Therefore, each semi-cylindrical molding section 70 simultaneously molds two circumferentially adjacent protective pieces 12', 12' to form divided bodies 14', 14' equipped with those protective pieces 12', 12'.

[0080] Between the two protective piece molding surfaces 72, 72 in one semi-cylindrical molding section 70, a fin-shaped projection 74 extends in the longitudinal direction (up and down direction in Figure 9). The fin-shaped projection 74 forms a slit 38 between the two protective pieces 12', 12' formed by the two protective piece molding surfaces 72, 72. The base end of the fin-shaped projection 74 is continuous with the window molding section 102 (described later) that forms the housing window section 34.

[0081] The protective piece molding surface 72 of the inner mold 64 is provided with a first ejector pin 76, which serves as a protective piece ejector. The first ejector pin 76 has a slender, approximately cylindrical shape and is designed to protrude in such a way that its protrusion height from the protective piece molding surface 72 changes in the direction of release. That is, when the protective piece 12' is being molded, the first ejector pin 76 is housed in the inner mold 64 as shown in Figures 10 and 11, and the tip surface of the first ejector pin 76, which has a protrusion height of approximately 0 from the protective piece molding surface 72, constitutes a part of the protective piece molding surface 72 of the inner mold 64. As can be seen from this, the tip surface of the first ejector pin 76 has a shape that corresponds to the inner circumferential surface of the protective piece 12', and in this embodiment, it has a cross-sectional shape that is curved in an approximately arc shape and has an inclined surface that slopes toward the opposite side of the release direction (see Figure 8) as it moves away from the fin-shaped projection 74 in the width direction. Then, when demolding the protective piece 12', as shown in Figures 12 and 13, the first ejector pin 76 is activated to protrude from the protective piece molding surface 72 in the demolding direction, thereby pushing the protective piece 12' in the demolding direction and releasing it from the protective piece molding surface 72. Figures 12 and 13 show the state in which the protruding height of the first ejector pin 76 is at its maximum. The first ejector pin 76, when in the protruding state, can be re-received into the inner mold 64 in a manner that reduces its protruding height.

[0082] In this embodiment, a plurality of first ejector pins 76 are arranged in the longitudinal direction (up and down direction in Figure 9) of the protective piece molding surface 72. When the protective piece 12' is released from the inner mold 64, the protective piece 12' is pushed out at multiple points along its length by these plurality of first ejector pins 76. This prevents plastic deformation such as bending and twisting, which can easily become a problem when a long protective piece 12' is pushed by the first ejector pins 76. It is desirable that three or more first ejector pins 76 are arranged in the longitudinal direction of the protective piece molding surface 72, and in this embodiment, four are provided. The first ejector pins 76 in this embodiment include a tip ejector pin 76a located at the tip end and a base ejector pin 76b located closer to the base end than the tip ejector pin 76a. The base ejector pin 76b has a larger diameter than the tip ejector pin 76a, and the input from the tip ejector pin 76a acting on the tip side of the protective piece 12', which has low resistance (deformation rigidity), is reduced. In this embodiment, one tip ejector pin 76a and multiple base ejector pins 76b are arranged in the longitudinal direction, and when demolding from the inner mold 64, the one tip ejector pin 76a and multiple base ejector pins 76b abut against one protective piece 12'. The tip ejector pin 76a is located on the tip side of the portion that forms the curved portion 40 of the slit 38 in the fin-shaped projection 74. The base ejector pin 76b is located on the base side of the portion that forms the curved portion 40 of the slit 38 in the fin-shaped projection 74.

[0083] A positioning pin 78 is provided on the protective piece molding surface 72 of the inner mold 64 as a positioning part. The positioning pin 78 has a slender, approximately cylindrical shape and is provided so as to protrude from the protective piece molding surface 72 in the direction of release. The positioning pin 78 then protrudes into the cavity 68 of the molding die 62 and is inserted in the direction of release from the protective piece 12' that is molded in the cavity 68.

[0084] It is preferable that at least one of the positioning pins 78 is located within a range of 1 / 2 or less of the sum of the lengths of the protective piece 12' (protective piece molding surface 72) and the columnar portion 32' (columnar portion molding surface 100, described later) from the tip of the protective piece 12', and more preferably within a range of 1 / 3 or less. It is also preferable that at least one of the positioning pins 78 is located within a range of 1 / 2 or less of the length of the protective piece 12' (protective piece molding surface 72) from the tip in the longitudinal direction of the protective piece 12', and more preferably located towards the tip side of the center in the longitudinal direction of the protective piece 12' (protective piece molding surface 72). Furthermore, it is preferable that at least two first ejector pins 76 are provided within a range of 1 / 2 or less of the sum of the lengths of the protective piece 12' (protective piece molding surface 72) and the columnar portion 32' (columnar portion molding surface 100, described later) from the tip of the protective piece 12', and that the positioning pin 78 is provided between the tip ejector pin 76a and the base ejector pin 76b within that range. More preferably, the portion that forms the curved portion 40 of the slit 38 in the fin-shaped projection 74 is located between the tip ejector pin 76a and the base ejector pin 76b within that range. Furthermore, the positioning pin 78 is provided between the first ejector pin 76 located at the very tip and the second first ejector pin 76 located from the tip, efficiently suppressing deformation during demolding at the tip side of the protective piece 12' where the resistance force (deformation rigidity) is small.

[0085] The positioning pins 78 and the multiple first ejector pins 76 are each formed in pairs, flanking the fin-shaped projections 74. The pairs of positioning pins 78, positioned at corresponding locations on both sides of the fin-shaped projections 74, are set to have approximately the same separation distance from the fin-shaped projections 74. Similarly, the pairs of first ejector pins 76, positioned at corresponding locations on both sides of the fin-shaped projections 74, are each set to have approximately the same separation distance from the fin-shaped projections 74. Furthermore, with respect to the first ejector pins 76, it is desirable that the circumferential position of the protective piece 12' be located closer to the fin-shaped projections 74 than to the center in the circumferential direction of the inner circumferential molding surface 69 of the inner mold 64. This prevents deformation of the protective piece 12' caused by sliding resistance or snagging with the fin-shaped projections 74, as the side of the protective piece 12' closest to the fin-shaped projections 74, which experiences sliding resistance with the fin-shaped projections 74, is pushed away from the inner circumferential molding surface 69 by the first ejector pins 76. Similarly, with respect to the positioning pin 78, it is desirable to set the circumferential position of the protective piece 12' closer to the fin-shaped projection 74 than to the center in the circumferential direction of the inner molding surface 69 of the inner mold 64, in order to improve the stability of the positioning operation during demolding.

[0086] The protrusion height of the positioning pin 78 from the protective piece molding surface 72 is smaller than the protrusion height of the first ejector pin 76 in its maximum protrusion state. The protrusion height of the positioning pin 78 is smaller than the thickness of the protective piece 12', preferably half or less of the thickness of the protective piece 12'. Unlike the first ejector pin 76, the positioning pin 78 does not change its protrusion height due to its ejection operation, but rather protrudes onto the molding surface where the first ejector pin 76 is provided at least during the process from molding to demolding of the protective piece 12', thereby positioning the protective piece 12' relative to the molding die (inner mold 64). In this embodiment, the positioning pin protrudes onto the molding surface at a constant protrusion height and is fixedly provided on the inner mold 64.

[0087] As shown in Figures 3 and 4, the inner circumferential surface of the protective piece 12' has multiple first pressed portions 80 that are pressed by multiple first ejector pins 76 during demolding, and a positioning portion 82 that serves as a positioning step portion where the positioning pin 78 is removed. The positioning portion 82 is formed on the curved plate-like surface of the protective piece 12'. That is, the positioning portion 82 is formed in the middle portion of the protective piece 12', excluding the circumferential end of the protective piece 12'. The contact portion of the first ejector pin 76 on the inner circumferential surface of the protective piece 12' where the first pressed portions 80 are formed is a first extrusion surface that is inclined in the width direction, sloping toward the opposite side of the demolding direction as it moves away from the fin-shaped projection 74. The tip surface of the first ejector pin 76 is shaped to make surface contact with the first extrusion surface.

[0088] A base molding section is formed at the base end of the semi-cylindrical molding sections 70a and 70b, and as shown in Figure 9, a tube insertion section molding surface 84 is provided for each, which forms the inner circumferential surface of the divided insertion section that constitutes the tube insertion section 18 of the needle tip protector 10'. As shown in Figures 10 and 11, the tube insertion section molding surface 84 has two inclined surfaces 86, 86 that form the tube holding surfaces 28, 28, and a second ejector pin 90 is provided on the ridge line 88 which is the intersection of these inclined surfaces 86, 86. The second ejector pin 90, like the first ejector pin 76, is capable of protruding approximately parallel to the release direction, and is released from the inner mold 64 by pushing out the divided insertion section. Furthermore, the second ejector pin 90, when in the protruding state, can be re-embedded in the inner mold 64 so that its protruding height is reduced. Two second ejector pins 90 are provided in each semi-cylindrical molding section 70, arranged at a predetermined distance apart in the longitudinal direction (up and down direction in Figure 9). Fin-shaped protrusions 74 are located on the imaginary line connecting the second ejector pins 90. Multiple second pressed portions 92 are formed on the inner circumferential surface of the divided insertion portion of the needle tip protector 10', which are pressed by the multiple second ejector pins 90 during demolding. The tube insertion portion molding surface 84 of the semi-cylindrical molding section 70a is provided with a molding structure for a connecting hole 22, and the tube insertion portion molding surface 84 of the semi-cylindrical molding section 70b is provided with a molding structure for a connecting hook 20. The tip surface of the second ejector pin 90 has a shape corresponding to the formation portion of the second pressed portion 92 in the divided insertion portion, and in this embodiment, it has a V-shaped cross section that slopes from the center in the width direction of the tube insertion portion molding surface 84 toward both sides toward the opposite side of the demolding direction.

[0089] The tip of the tube insertion portion molding surface 84 is the base portion molding surface 94 that forms the base portion 24 of the needle tip protector 10'. The base portion molding surface 94 forms the inner circumference of the half-circumferential portion (divided base portion) of the base portion 24. In this embodiment, the molding die 62 is composed of the components of the tube insertion portion molding surface 84 and the components of the base portion molding surface 94. The base portions 70a and 70b are connected to each other by a hinge molding portion that forms the hinge-shaped portion 16 (see Figure 9).

[0090] The base molding surface 94 of the inner mold 64 is provided with third ejector pins 96, 96 at both ends in the circumferential direction, serving as base ejectors. The third ejector pins 96, like the first and second ejector pins 76, 90, push out half of the base portion 24 by protruding, releasing it from the inner mold 64. The protruding third ejector pins 96 are also designed to be re-retractable into the inner mold 64 so that their protruding height is reduced. As shown in Figures 3 and 4, a third pressed portion 98 is formed on the circumferential end face of the half-circumferential portion of the base portion 24 of the needle tip protector 10', which is pressed by the third ejector pins 96 during release. The circumferential end face of the half-circumferential portion of the base portion 24 is a plane that extends substantially perpendicular to the release direction from the inner mold 64, and this plane constitutes the second extrusion surface of this embodiment. The circumferential end faces of the half-circumferential portion of the base portion 24 are each designated as second extrusion surfaces, and during demolding, the third ejector pins 96 abut against both ends in the width direction of the divided body 14'. The tip surface of the third ejector pin 96 is shaped to make surface contact with the second extrusion surface, and in this embodiment, it is a plane that extends perpendicular to the protrusion direction.

[0091] Between the protective piece molding surfaces 72, 72 and the tube insertion part molding surface 84 (base part molding surface 94), a columnar part molding surface 100 is provided for molding the columnar part 32'. The columnar part molding surface 100 is continuous with the protective piece molding surface 72 and the base part molding surface 94, and molds the columnar part 32' so as to be integrally continuous between the protective piece 12' and the base part 24. Two columnar part molding surfaces 100 are provided, separated from each other in the circumferential direction, and on one side in the circumferential direction of each columnar part molding surface 100, a window molding part 102 is provided for molding a receiving window part 34 that penetrates in the radial direction. In this embodiment, the inner mold 64 has an inner circumferential molding surface 69 which includes the protective piece molding surfaces 72, 72, 72, 72, the tube insertion part molding surfaces 84, 84 including the base part molding surfaces 94, 94, and the columnar part molding surfaces 100, 100.

[0092] In this embodiment, as shown in Figure 9, an inner mold 64 consisting only of the molding portion of the needle tip protector 10' is illustrated. However, the inner mold may extend not only to the molding portion of the needle tip protector 10' but also to its surroundings, or it may extend to connect the two semi-cylindrical molding portions 70a and 70b. In such cases, the molding die is clamped, for example, with the inner mold and outer mold overlapping in the area excluding the molding portion of the needle tip protector 10'.

[0093] On the other hand, the outer mold 66 is superimposed on the inner mold 64 from the outside in the demolding direction (right side in Figure 8), covering the semi-cylindrical molded portions 70a and 70b of the inner mold 64. The outer mold 66 has an outer peripheral molding surface 104 that forms the wall surface of the cavity 68 and molds the outer peripheral surface of the needle tip protector 10'. The molded portion of the protective piece 12' on the outer peripheral molding surface 104 is an inclined surface that approaches the inner mold 64 as it goes toward the tip. In this embodiment, the outer peripheral molding surface 104 is an inclined surface that inclins toward the same side as the molded portion of the columnar portion 32', in addition to the molded portion of the protective piece 12'. As a result, the protective piece 12' and the columnar portion 32' have an outer peripheral surface that inclins toward the outer periphery toward the base end, and the base side is thicker. When the inclined surface of the outer peripheral molding surface 104 is partially provided in the longitudinal direction of the outer peripheral molding surface 104, it is desirable that the length dimension of the inclined surface be at least half the length dimension of the protective piece 12'. Furthermore, when the inclined surface of the outer peripheral molding surface 104 is partially provided along the length of the outer peripheral molding surface 104, it is desirable that the inclined surface be provided on the base end side of the protective piece 12', and more preferably that it be provided so as to extend to the columnar portion 32' including the base end of the protective piece 12'. In addition, the inner circumferential surfaces of the protective piece 12' and the columnar portion 32' are preferably shaped parallel to the central axis of the needle tip protector 10' or shaped inclined inward toward the tip, and it is desirable that the protective piece molding surface 72 and the columnar portion molding surface 100 of the inner mold 64 be inclined surfaces or non-inclined surfaces that are inclined toward the direction of separation from the outer mold 66 as they go toward the tip. In this embodiment, the fin-shaped projection 74, the first to third ejector pins 76, 90, 96 and the positioning pin 78 are all provided on the inner mold 64 of the molding die 62, and the structure of the outer mold 66 is simplified.

[0094] As shown in Figure 8, the inner mold 64 and outer mold 66, having this structure, are stacked on top of each other to form a molding die 62. The molding die 62 has a cavity 68 between the inner mold 64 and the outer mold 66, and a molding process in which a resin material such as polypropylene is filled into the cavity 68 and molded forms a molded product of a needle tip protector 10' in an unfolded state with multiple protective pieces 12' arranged in the direction (circumferential direction) as shown in Figure 7. In this embodiment, the needle tip protector 10' is molded in an unfolded state consisting of two divided bodies 14', 14' connected to each other by a hinge-like portion 16 in the direction of the arrangement of the protective pieces 12' during the molding process. In this embodiment, the divided insertion portions of the two divided bodies 14', 14' are connected to each other by the hinge-like portion 16. The molded product of the needle tip protector 10' is preferably an injection-molded resin product. The resin material is injected into the cavity 68 through a gate (not shown) provided in the molding die 62.

[0095] In the molding process, the protective piece 12' of the needle tip protector 10' is molded with the positioning pins 78 of the inner mold 64, which protrude into the cavity 68, inserted into it. As a result, the protective piece 12' is positioned circumferentially with respect to the inner mold 64 by engagement with the positioning pins 78 inserted into the positioned portion 82, which is a positioning step. The positioning pins 78 are positioned away from both ends of the protective piece 12' in the width direction. That is, the positioning pins 78 are located in the middle portion of the protective piece in the width direction, and position the protective piece 12' with respect to the molding die 62. More specifically, the positioning pins 78 are located on a virtual line connecting a plurality of first ejector pins 76.

[0096] After the molding process is complete, the outer mold 66 is removed from the inner mold 64. When the outer mold 66 is removed, the molded part of the needle tip protector 10' is held by the inner mold 64, and the molded part of the needle tip protector 10' is released from the outer mold 66.

[0097] Next, the first to third ejector pins 76, 90, and 96 of the inner mold 64 are extended and abutted against the molded product of the needle tip protector 10', thereby pushing the molded product of the needle tip protector 10' in the demolding direction relative to the inner mold 64. This completes the demolding process, which removes the molded product of the needle tip protector 10' from the inner mold 64.

[0098] In this embodiment, the needle tip protector 10' is released from the inner mold 64 by the first ejector pin 76 pushing out the protective piece 12', the second ejector pin 90 pushing out the divided insertion portion, and the third ejector pin 96 pushing out the base portion 24. By pushing out the divided insertion portion and the base portion 24, which have greater deformation rigidity than the protective piece 12', with the second and third ejector pins 90 and 96, the deformation of the protective piece 12' during release is suppressed compared to the case where only the protective piece 12' is pushed out. In addition, the circumferential end face of the base portion 24 in the divided body 14' is a plane that is substantially perpendicular to the protruding direction of the third ejector pin 96, and the third ejector pin 96 is pressed against the second extrusion surface formed by this plane. Therefore, misalignment of the molded product of the needle tip protector 10' and the inner mold 64, as well as slippage of the third ejector pin 96, are prevented from occurring due to the component force when the third ejector pin 96 contacts the second extrusion surface, thereby enabling more stable demolding.

[0099] The third ejector pins 96, 96 are located on both outer sides in the width direction of the protective piece 12' relative to the first ejector pin 76, and the moment acting on the base portion 24 due to the contact of the third ejector pins 96, 96 is canceled out, thus enabling stable demolding. In this embodiment, in a structure in which divided bodies 14', 14' molded in an unfolded state in the direction of the alignment of the protective piece 12' are connected by a thin-walled hinge-like portion 16, the pair of third ejector pins 96, 96 are positioned on the side closer to the hinge-like portion 16 and the side further away from it, respectively, thereby suppressing unintended deformation of the hinge-like portion 16. As a result, when the divided bodies 14', 14' are combined to form a cylindrical needle tip protector 10', variations in the shape of the needle tip protector 10' caused by deformation of the hinge-like portion 16 are suppressed, and the needle tip protection performance of the needle tip protector 10' is stabilized.

[0100] Multiple first ejector pins 76 are arranged in a line along the length of the protective piece 12'. As a result, during the demolding process, the first ejector pins 76 abut against the protective piece 12' at multiple points along its length, and the force exerted by the abutting of the first ejector pins 76 is applied over a wide area along the length of the protective piece 12'. As a result, problems such as the protective piece 12' being locally demolded from the inner mold 64 and bending are prevented, and the protective piece 12' can be stably demolded from the inner mold 64. Therefore, in the needle tip protector 10' manufactured by the manufacturing method according to this embodiment, the shape of the protective piece 12' is stabilized during demolding, and unintended widening of the slit 38 between adjacent protective pieces 12', 12' in the circumferential direction is suppressed. Thus, in the needle tip protected state, exposure of the needle tip 50 to the outside through the slit 38 is prevented, and the needle tip protection performance is stabilized.

[0101] In the demolding process, the tip ejector pin 76a abuts against the tip portion of the protective piece 12', while multiple base ejector pins 76b abut against the protective piece 12' at a base end closer to the tip ejector pin 76a. As a result of the multiple first ejector pins 76, which consist of the tip ejector pin 76a and multiple base ejector pins 76b, abutting against the protective piece 12', the protective piece 12' is released from the inner mold 64.

[0102] In the initial stage of the demolding process, when the protrusion height of the first ejector pin 76 is less than or equal to the protrusion height of the positioning pin 78, as shown in Figure 14, the positioning pin 78 is maintained in a state where it is inserted into the positioned portion 82 of the protective piece 12', and the positioning state of the protective piece 12' in the circumferential direction by the positioning pin 78 is maintained. More specifically, the positioning pin 78 positions the protective piece 12' in a state where it is positioned on all four sides (both sides in the circumferential direction and both sides in the axial direction) at approximately the center in the circumferential direction. In this way, by maintaining the positioning state of the protective piece 12' by the positioning pin 78 and then abutting the first ejector pin 76 against the protective piece 12' to advance the demolding of the protective piece 12' from the inner mold 64, the first ejector pin 76 can be pressed straight against the elongated and easily deformable protective piece 12'. In addition, the wobble of the protective piece 12' due to the impact when the first ejector pin 76 abuts against it is suppressed, and the protective piece 12' can be pushed straight in the demolding direction. Therefore, the force from the first ejector pin 76 is prevented from acting on the protective piece 12' in an unintended direction, thereby reducing the likelihood of deformation of the protective piece 12' during demolding. In particular, the more slits there are, the more likely deformation of the protective piece 12' is to occur during demolding, so it is preferable to provide a positioning pin 78 when the needle tip protector 10' has four or more slits 38. By suppressing the unintended widening of the slits 38 between adjacent protective pieces 12', 12' in the circumferential direction, exposure of the needle tip 50 to the outside through the slits 38 is prevented in the needle tip protection state, thereby stabilizing the needle tip protection performance.

[0103] Furthermore, the protruding height dimension of the positioning pin 78 is made smaller than the protruding height dimension of the first ejector pin 76 in its maximum protruding state. Therefore, the positioning pin 78 is more reliably released from the protective piece 12' by the extrusion of the protective piece 12' by the first ejector pin 76, preventing deformation of the protective piece 12' due to poor release of the positioning pin 78 from the protective piece 12'.

[0104] In the molding process, the positioning pin 78 is inserted into the protective piece 12' within a range of 1 / 2 or less of the length of the tip of the protective piece 12'. As a result, the tip portion of the protective piece 12', which is prone to large circumferential displacement relative to the inner mold 64, is maintained in a positioned state by the positioning pin 78, while the release of the protective piece 12' from the inner mold 64 proceeds. Therefore, deformation of the protective piece 12' caused by displacement of the protective piece 12' relative to the inner mold 64 during release, and a decrease in the efficiency of transmitting the release force to the protective piece 12' are prevented.

[0105] The first ejector pin 76 releases the protective piece 12' through multiple (three in this embodiment) ejection operations. Furthermore, as shown in Figure 15, the initial speed v1 of the first ejection operation of the first ejector pin 76 is set to be slower in the same direction than the initial speed v2 of the other ejection operations. In this embodiment, the speed of the first ejection operation changes at a point t during the ejection operation. The initial speed before the speed change point t is set to a low speed v1, while the final speed after the speed change point t is set to be faster than the initial speed v1 of the first ejection operation and the same as the initial speed v2 of the other ejection operations. For example, the speed change point t is set to the point when the ejection height of the first ejector pin 76 becomes the same as the ejection height of the positioning pin 78. In the positioning state by the positioning pin 78, the ejection speed of the first ejector pin 76 is set to a low speed v1, and when the positioning by the positioning pin 78 is released, the ejection speed of the first ejector pin 76 is set to be faster. However, the initial ejection speed of the first ejector pin 76 may be constant v1 throughout the entire ejection operation, or it may be maintained at a low speed until the ejection height of the first ejector pin 76 is higher than the ejection height of the positioning pin 78, or it may be increased when the ejection height of the first ejector pin 76 is lower than the ejection height of the positioning pin 78. In this embodiment, the second and third ejection operations, which are the other ejection operations, are set at a substantially constant speed from the start to the completion of the ejection operation. The second and third ejector pins 90 and 96 may have different ejection speeds (for example, a speed faster than the terminal speed after the speed increase of the first ejector pin 76) and ejection heights, etc., than the first ejector pin 76, but in this embodiment, the ejection speeds, etc., are the same as those of the first ejector pin 76, and the initial speed of the first ejection operation is set to v1, which is lower than the initial speed v2 of the other ejection operations.

[0106] When the protective piece 12' is released from the inner mold 64 by abutting with the first ejector pin 76, the protective piece 12' may be stuck to or embedded in the inner mold 64 before the release begins. In such cases, if the first ejector pin 76 is forcefully abutted against the protective piece 12', a large force may be applied to the protective piece 12', causing it to deform or be damaged, or the protective piece 12' may escape from the first ejector pin 76, preventing it from being sufficiently pushed out of the inner mold 64. In particular, the protective piece 12' has a long shape that is easily deformed in the circumferential direction, and is connected to the base portion 24, which has relatively high deformation rigidity, via a thinner columnar portion 32', making it difficult to expect any reinforcing effect from the base portion 24.

[0107] Therefore, the initial speed of the first ejector pin 76's first ejection is set to a low speed, and when the first ejector pin 76 first abuts against the protective piece 12', the first ejector pin 76 is slowly pressed against the protective piece 12'. This prevents damage to the protective piece 12' due to excessive ejection or poor demolding due to displacement (escape) of the protective piece 12' when the first ejector pin 76 abuts against it, even if the protective piece 12' is stuck to the inner mold 64 before demolding begins. In a needle tip protector 10' manufactured by this manufacturing method according to this embodiment, deformation of the protective piece 12' during demolding is suppressed, and unintended widening of the slit 38 between adjacent protective pieces 12', 12' in the circumferential direction is suppressed. As a result, in the needle tip protected state, exposure of the needle tip 50 to the outside through the slit 38 is prevented, and the needle tip protection performance is stabilized.

[0108] Furthermore, since the initial speed of the second and third ejection operations of the first ejector pin 76 is set to be faster than the initial speed of the first ejection operation, the time required for the demolding process can be shortened, thereby improving manufacturing efficiency. In addition, since any sticking or entrapment of the protective piece 12' to the inner mold 64 is resolved by the first ejection operation of the first ejector pin 76, even if the initial speed of the second and third ejection operations is faster than the initial speed of the first ejection operation, damage to the protective piece 12' and poor transmission of demolding force are less likely to become problems.

[0109] In this embodiment, an example is shown where the initial speed of the first protrusion operation is lower than the initial speeds of all other protrusion operations. However, it is sufficient that the initial speed of the first protrusion operation is lower than the initial speed of at least one other protrusion operation. Specifically, for example, the initial speed of the second protrusion operation may be the same low speed as the initial speed of the first protrusion operation, and the initial speed of the third protrusion operation may be higher than the initial speed of the first protrusion operation. Alternatively, the initial speed of the second protrusion operation may be higher than the initial speed of the first protrusion operation, and the initial speed of the third protrusion operation may be the same as or even lower than the initial speed of the first protrusion operation. Furthermore, the number of protrusion operations is not limited to three; it may be two, four or more, or any number of protrusion operations.

[0110] Furthermore, it is not essential that the initial and final speeds of the first ejector pin 76 differ during its initial ejection. For example, the initial ejection may be performed at a constant speed lower than the initial speed of at least one other ejection. Moreover, the final speed of the initial ejection may be even lower than the initial speed. It is also possible to set two or more speed changes within a single ejection. Additionally, the demolding process may include an ejection operation at a speed lower than the initial speed of the first ejection.

[0111] By making the ejection operation of the second and third ejector pins 90 and 96 approximately the same as that of the first ejector pin 76, the entire molded product of the needle tip protector 10' is released from the mold approximately simultaneously, preventing deformation of the molded product of the needle tip protector 10' due to differences in the ejection heights of the first to third ejector pins 76, 90, and 96.

[0112] Since the first to third ejector pins 76, 90, 96 and the fin-shaped projection 74 are all provided on the inner mold 64, the contact of the first to third ejector pins 76, 90, 96 makes it difficult for a component force to act on the protective pieces 12', 12' located on both sides of the fin-shaped projection 74 in a direction that pushes it toward the fin-shaped projection 74, thereby preventing mold release defects due to frictional resistance between the fin-shaped projection 74 and the protective pieces 12', 12'.

[0113] The resin molded product released from the inner mold 64 (a needle tip protector 10' with multiple protective pieces 12' arranged in the circumferential direction as shown in Figures 3 and 4) is formed into a cylindrical needle tip protector 10' by a connecting process in which the hinge-like portion 16 is bent and the divided parts 14', 14' are combined so that they face each other. The divided parts 14', 14' have one end in the circumferential direction pre-connected by the hinge-like portion 16, and the other end in the circumferential direction is connected to each other by a connecting hook 20 and a connecting hole 22 in the connecting process after the release process, thereby forming a cylindrical needle tip protector 10'.

[0114] As described above, the needle tip protector 10' can stably achieve the desired needle tip protection performance by stabilizing the extrusion manner of the molded product from the inner mold 64 and adjusting the speed at which the molded product is extruded from the inner mold 64, thereby suppressing deformation of the protective piece 12' during demolding. In particular, the needle tip protector 10' has the base end of the protective piece 12' connected to the base part (base part 24) via a thin columnar part 32', resulting in a small resistance force of the protective piece 12' to input. Furthermore, the slit 38 between the protective pieces 12', 12' is structured in such a way that it is easily widened unintentionally due to deformation of the columnar part 32'. Even in a needle tip protector 10' with such a structure, widening of the slit 38 caused by deformation of the protective piece 12' and columnar part 32' can be prevented by controlling the force acting on the protective piece 12' and columnar part 32' during demolding.

[0115] The protective piece 12' and columnar portion 32' of the needle tip protector 10', which is a resin molded product released from the inner mold 64, have an inner circumferential surface formed by the inner circumferential molding surface 69 of the inner mold 64 that extends substantially parallel to the axial direction in at least the portion excluding the tip of the protective piece 12', and an outer circumferential surface formed by the outer circumferential molding surface 104 of the outer mold 66 that slopes inward toward the tip side. As a result, the deformation direction of the protective piece 12' and columnar portion 32' due to thermal shrinkage after molding is easily directed toward the inward side toward the tip. In this way, by appropriately setting the inclination of the inner circumferential molding surface 69 and the outer circumferential molding surface 104 that constitute the wall surface of the cavity 68 of the molding die 62, the protective piece 12' can be guided to deform toward the inward side due to thermal shrinkage, thereby preventing problems such as the exposure of the needle tip 50 through the slit 38 caused by the slit 38 opening too wide due to thermal shrinkage. Furthermore, if the first ejector pin 76 is on the inner mold 64 side, the protective piece 12' that is pushed outward may deform to expand, and the slit 38 between the protective pieces 12', 12' may widen during demolding. However, because the protective piece 12' deforms in a direction that narrows the width of the slit 38 due to thermal shrinkage after demolding, widening of the slit 38 during demolding is less likely to be a problem. Note that thermal shrinkage after molding is greater for thicker materials, so in a needle tip protector 10' having a columnar portion 32' that forms a receiving window portion 34 between the protective piece 12' and the base portion 24, it is preferable to adjust the shapes of the inner mold 64 and the outer mold 66 so that a thick portion is formed in the columnar portion 32'.

[0116] Although embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the divided bodies 14, 14 constituting the needle tip protector 10 do not necessarily have to be connected by a hinge-like portion 16 at one end in the circumferential direction. Specifically, for example, a divided needle tip protector can be constructed by fixing mutually independent divided bodies 14, 14 at both ends in the circumferential direction. In short, in the molding process, a needle tip protector for winged needles may be molded in an unfolded state consisting of a plurality of divided bodies separated in the direction of the arrangement of protective pieces. In this case, the independent divided bodies 14, 14 may each be formed in an independent molding die, thereby reducing the size of the molding die. That is, after releasing the divided bodies 14, 14 that have been molded independently in an unfolded state in the direction of the arrangement of protective pieces, the needle tip protector 10 may be manufactured by connecting the circumferential ends of the two independent divided bodies 14, 14 by means of adhesive, welding, mechanical engagement, etc., in the connecting process. Furthermore, it is desirable that each part (divided body 14) of the needle tip protector 10, which is molded in the unfolded state, constitutes a circumferential region of less than half the circumference of the needle tip protector 10. In addition, each divided body 14 may be molded from the same molding die. For example, if a connecting hook is provided at one end of the divided body 14 in the circumferential direction and a connecting hole at the other end, a cylindrical needle tip protector can be formed by connecting multiple divided bodies molded from the same die.

[0117] In the first embodiment, the molded product released from the outer mold 66 is held on the inner mold 64 side, and an example was shown in which the molded product is released from the inner mold 64 by the ejection operation of the first to third ejector pins 76, 90, 96. However, for example, the molded product released from the inner mold 64 may be held on the outer mold 66 side. In this case, the first to third ejector pins 76, 90, 96 and a positioning pin 78 are provided on the outer mold 66. Furthermore, the fin-shaped projection 74 for forming the slit 38 and the window forming section 102 for forming the housing window 34 can also be provided on the outer mold 66. For example, if the first to third ejector pins 76, 90, 96 and the fin-shaped projection 74 are all provided on the outer mold 66, the contact of the first to third ejector pins 76, 90, 96 with the protective pieces 12', 12' will exert a component force toward the fin-shaped projection 74 on the protective pieces 12', 12' located on both sides of the fin-shaped projection 74. Therefore, it can be expected that the fin-shaped projection 74 will also guide the protective pieces 12', 12' during demolding.

[0118] The positioning pin 78 inserted into the protective piece 12' may penetrate the protective piece 12'. In this case, it is desirable that the outer diameter of the positioning pin 78 be sufficiently small so that the needle tip 50 of the wing-shaped needle 46, which is housed and protected on the inner circumference of the protective piece 12', does not become exposed to the outside through the through hole after the positioning pin 78 is withdrawn, and also for the purpose of ensuring the deformation strength of the molded product. Preferably, the positioning pin 78 is located towards the tip side of the center in the longitudinal direction of the protective piece 12', but it may also be located towards the base end side of the center, or may be provided on both the tip side and the base end side, respectively, in order to obtain the effect of suppressing deformation during demolding. In addition, although there is one positioning pin 78 in the above embodiment, there may be multiple pins. Also, although the positioning pin 78 in the above embodiment is cylindrical with a circular cross-section, the shape is not limited to this. Furthermore, instead of or in addition to the positioning pin 78, a positioning recess is provided on the molding surface of the molding die 62 (recessed toward the opposite side of the release direction), and a positioning projection is formed on the surface of the protective piece 12' as a positioning step that fits into the positioning recess. The protective piece 12' can then be positioned relative to the molding die 62 by the engagement of the positioning recess and the positioning projection. For example, the positioning structure can also be configured with protrusions and grooves that extend continuously in the longitudinal direction of the protective piece. Moreover, it is preferable to form the positioning recess as a positioning step on the surface of the protective piece using a positioning pin provided on the molding surface of the molding die, rather than forming the positioning projection as a positioning step on the surface of the protective piece using a positioning recess provided on the molding surface of the molding die. Minimizing the number of protrusions on the inner surface of the protective piece helps to prevent snagging when housing the wing-shaped needle.

[0119] The arrangement, number, size, and shape of the first ejector pins 76 can be changed as appropriate. For example, the pin shape can be a flattened cross-sectional shape such as an ellipse instead of a circle. There may be only one first ejector pin 76 that pushes out the protective piece 12' at one point, but mold residue of the protective piece 12' is likely to occur at a location away from the first ejector pin 76, and the deformation of the protective piece 12' due to the mold residue may cause the slit 38 to widen, etc., and there is a risk that the puncture needle 48 will be exposed through the slit 38. For example, if the first ejector pin 76 has a flattened or elongated cross-sectional shape such as an ellipse, and the elongated direction of the cross-section is the length direction of the protective piece 12', the risk of deformation of the protective piece 12' can be mitigated even with a single first ejector pin 76, but structural and precision problems may arise. In order to stably release the longitudinal protective piece 12', it is desirable that the multiple first ejector pins 76 be positioned at multiple locations along the length of the protective piece 12'. By arranging the multiple first ejector pins 76 in a line along the length of the protective piece 12', the stress generated on the protective piece 12' by the pressing of the first ejector pins 76 during demolding can be distributed, and a narrow, elongated slit 38 formed between the protective pieces 12', 12' can be stably formed. Similarly, the arrangement, number, size, shape, etc., of the second ejector pins 90 and third ejector pins 96 are not limited.

[0120] The needle tip protector for a winged needle according to the present invention preferably comprises four protective pieces 12, 12, 12, 12, but is not limited thereto. The needle tip protector for a winged needle may also have a structure in which three or more segments are combined in the circumferential direction. In this case, for example, a molding die capable of molding a molded product integrally comprising three or more segments in an unfolded state may be used, or a molding die that molds one or more of the segments independently may be used.

[0121] 10, 10' Needle tip protector for winged needle (first embodiment, another embodiment) 12, 12' Protective piece 14, 14' Divided body 16 Hinged part 18 Tube insertion part 19 Anti-slip projection 20 Connecting hook 22 Connecting hole 24 Base part 26 Corner part 28 Tube holding surface 30 Tube holding groove 32, 32' Columnar part 34 Receiving window part 38 Slit 40 Curved part 42 Removal part 44 Inclined part (widening part) 46 Winged needle 48 Puncture needle 50 Needle tip 52 Needle hub 54 Wing part 56 Connecting part 58 Wing body 60 Tube 62 Molding mold 64 Inner mold 66 Outer mold 68 Cavity 69 Inner circumferential molding surface 70 (70a, 70b) Semi-cylindrical molded section 72 Protective piece molded surface 74 Fin-shaped projection 76 First ejector pin (protective piece ejector) 76a Tip ejector pin (tip ejector) 76b Base ejector pin (base ejector) 78 Positioning pin (positioning step section) 80 First pressed section 82 Positioned section 84 Tube insertion section molded surface 86 Slope 88 Ridge 90 Second ejector pin 92 Second pressed section 94 Section molded surface 96 Third ejector pin (base ejector) 98 Third pressed section 100 Columnar section molded surface 102 Window molded section 104 Outer circumference molded surface

Claims

1. A method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip are arranged in a cylindrical shape relative to a circumferentially continuous base portion, and the needle tip of the winged needle is housed and protected on the inner circumference side of the plurality of protective pieces, comprising: a molding step of molding the needle tip protector for a winged needle in an unfolded state in the direction of the arrangement of the protective pieces; and a release step of releasing the protective pieces from the molding die while maintaining the protective pieces in a circumferential position relative to the molding die by positioning pins inserted into the protective pieces.

2. The method for manufacturing a needle tip protector for a winged needle according to claim 1, wherein in the molding step, the positioning pin is inserted within a range of 1 / 2 of the length of the protective piece from the tip when the protective piece is molded.

3. A method for manufacturing a needle tip protector for a winged needle according to claim 1 or 2, wherein, in the molding step, a plurality of protective pieces adjacent in the circumferential direction on both sides of a slit formed by fin-shaped protrusions protruding from the molding die are simultaneously molded, and in the demolding step, the plurality of protective pieces are extruded from the molding die at multiple locations in the longitudinal direction of each protective piece to demold them.

4. A method for manufacturing a needle tip protector for a winged needle according to any one of claims 1 to 3, wherein, in the mold release step in which a protective piece ejector provided in the molding die strikes the protective piece multiple times against the protective piece to release the protective piece from the molding die, the initial speed of the first ejection operation of the protective piece ejector is lower than the initial speed of at least one other ejection operation.

5. A method for manufacturing a needle tip protector for a winged needle according to any one of claims 1 to 4, wherein in the molding step, a molding die is used in which the outer peripheral molding surface for molding the outer peripheral surface of the protective piece is an inclined surface that approaches the inner peripheral molding surface for molding the inner peripheral surface of the protective piece as it approaches the tip side, and the needle tip protector for the winged needle is molded in an unfolded state in the direction in which the multiple protective pieces are arranged.

6. A method for manufacturing a needle tip protector for a winged needle according to any one of claims 1 to 5, wherein in the molding step, the needle tip protector for the winged needle is molded in an unfolded state consisting of a plurality of divided parts interconnected by hinge-like portions in the direction of the arrangement of the protective pieces.

7. A method for manufacturing a needle tip protector for a winged needle according to any one of claims 1 to 5, wherein in the molding step, the needle tip protector for the winged needle is molded in an unfolded state consisting of a plurality of divided parts separated in the direction of the arrangement of the protective pieces.

8. A method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip are arranged in a cylindrical shape relative to a circumferentially continuous base portion, and the needle tip of the winged needle is housed and protected on the inner circumference of the plurality of protective pieces, comprising: a molding step of molding a segmented body having the plurality of protective pieces provided adjacent to each other in the circumferential direction on both sides of a fin-shaped projection of a molding die, thereby forming a positioning step in the intermediate portion of the protective piece; a demolding step of releasing the segmented body from the molding die by abutting a protective piece ejector provided on the molding die against the protective piece while maintaining the protective piece in a circumferential position relative to the molding die by engagement of the positioning step of the protective piece with the molding die; and a connecting step of connecting a plurality of the segmented bodies in the circumferential direction to form a cylindrical needle tip protector for the winged needle.

9. The method for manufacturing a needle tip protector for a winged needle according to claim 8, wherein, in the release step, a plurality of protective piece ejectors are abutted against a plurality of locations in the longitudinal direction of each protective piece.

10. A method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip side from a circumferentially continuous base portion are arranged in a cylindrical shape, and the needle tip of the winged needle is housed and protected on the inner circumference side of the plurality of protective pieces, comprising: a molding step of molding the needle tip protector for the winged needle in an unfolded state in the direction of the arrangement of the protective pieces; and a demolding step of repeatedly striking the protective piece ejector provided in the molding die against the protective piece to release the protective piece from the molding die, wherein in the demolding step, the initial speed of the first ejection operation of the protective piece ejector is lower than the initial speed of at least one other ejection operation.

11. A method for manufacturing a needle tip protector for a winged needle, wherein a plurality of protective pieces extending toward the tip are arranged in a cylindrical shape relative to a circumferentially continuous base portion, and the needle tip of the winged needle is housed and protected on the inner circumference of the plurality of protective pieces, comprising: a molding step of molding the needle tip protector for a winged needle in an unfolded state in the direction of the arrangement of the protective pieces; a molding step of integrally molding the plurality of protective pieces that are formed on both sides of a fin-shaped projection protruding from a molding die and are adjacent to each other in the circumferential direction; and a release step of pushing out the plurality of protective pieces formed on both sides of the fin-shaped projection from the molding die by a protective piece ejector of the molding die at multiple locations in the longitudinal direction of each protective piece.

12. A method for manufacturing a needle tip protector for a winged needle according to claim 11, wherein, in the mold release step in which a protective piece ejector provided in the molding die strikes the protective piece multiple times against the protective piece to release the protective piece from the molding die, the initial speed of the first ejection operation of the protective piece ejector is lower than the initial speed of at least one other ejection operation.

13. A method for manufacturing a needle tip protector for a winged needle according to claim 11 or 12, wherein in the demolding step, a tip ejector is brought into contact with the tip portion of the protective piece, and a base ejector, which is located on the base end side of the tip ejector and has a larger diameter than the tip ejector, is brought into contact with the protective piece, and the protective piece is pushed out of the molding die by the protective piece ejector, which includes the tip ejector and the base ejector.

14. A method for manufacturing a needle tip protector for a winged needle according to any one of claims 11 to 13, wherein the molding die used in the molding process includes an inner mold for molding the inner circumferential surface of the protective piece and an outer mold for molding the outer circumferential surface of the protective piece, and the fin-shaped projection and the protective piece ejector are provided on either the inner mold or the outer mold.

15. A method for manufacturing a needle tip protector for a winged needle according to any one of claims 11 to 14, wherein the molding die used in the molding process includes an inner mold for molding the inner circumferential surface of the protective piece and an outer mold for molding the outer circumferential surface of the protective piece, and both the fin-shaped projection and the protective piece ejector are provided in the inner mold.

16. A method for manufacturing a needle tip protector for a winged needle according to any one of claims 11 to 15, wherein in the demolding step, the base portion is pushed out of the molding die by a pair of base ejectors on both outer sides in the width direction perpendicular to the demolding direction than the protective piece ejector.

17. A needle tip protector for a winged needle manufactured by the method for manufacturing a needle tip protector for a winged needle described in any one of claims 1 to 16.

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