indwelling needle

Abstract

To provide an indwelling needle in which separation of a component is reliably prevented in an assembly state without the occurrence of shaving and deformation of the component.SOLUTION: An indwelling needle includes a lower body part 20 and an upper body part 60. The upper body part 60 includes: a first projection 70 projectingly formed in a radial direction of the upper body part 60, and capable of being fit in a first fitting part 25 of the lower body part 20; and a second projection 75 provided at a grip part 64 formed in the upper body part 60, and being fit in a second fitting part 30 provided at the lower body part 20 when the upper body part 60 and the lower body part 20 are relatively rotated. The second projection 75 is configured such that at least a portion of the second projection 75 can be displaced in the radial direction of the upper body part 60.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an indwelling needle for continuously injecting a medicinal solution. [Background technology]

[0002] As disclosed in Patent Document 1, an indwelling needle is used that continuously injects a minute amount of medicinal liquid using a portable pump. In addition to the form of indwelling needle disclosed in Patent Document 1, a thin, circular indwelling needle is also known. Some indwelling needles of this form have a lower body portion that is fixed to the skin and an upper body portion that is assembled by rotating and mating with the upper part of the lower body.

[0003] In the above-described rotary engagement structure, when the upper body portion placed over the lower body portion is rotated, the claw portion provided on the upper body portion passes over the protrusion provided on the upper surface of the lower body portion, and the claw portion reaches the rotation completion position, completing the assembly. The user of the indwelling needle can know that the assembly is complete by the clicking sensation when the claw portion passes over the protrusion. The protrusion holds the claw portion in the rotation completion position, and the upper and lower body portions are maintained as a single unit without coming apart. Furthermore, when the upper body portion is to be removed, it can be rotated in the opposite direction to that during assembly, allowing the claw portion to pass over the protrusion and be removed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-088725 Summary of the Invention [Problem to be solved by the invention]

[0005] However, repeated assembly and removal causes the claws to rub against the protrusions each time they pass over them, causing the protrusions to be worn down or deformed. When the protrusions are worn down or deformed, the clicking sensation disappears, the rotational resistance in the removal rotation direction decreases, and there is a possibility that the upper body part may come off the lower body part.

[0006] The present invention has been made to solve the above problems, and has an object to provide an indwelling needle that reliably prevents separation of components in an assembled state without causing scraping or deformation of the components. [Means for solving the problem]

[0007] The indwelling needle of the present invention comprises a lower body portion and an upper body portion, the upper body portion having a first protrusion formed to protrude radially from the upper body portion and capable of engaging with a first engagement portion of the lower body portion, and a second protrusion provided on a gripping portion formed on the upper body portion and engaging with a second engagement portion provided on the lower body portion when the upper body portion and the lower body portion are rotated relative to each other, and at least a portion of the second protrusion is displaceable radially from the upper body portion.

[0008] According to the indwelling needle of the present invention, even if the needle is repeatedly assembled and disassembled, the second protruding portion, which is a constituent member, is not scraped or deformed, and separation of the constituent members in the assembled state can be reliably prevented.

[0009] Furthermore, the indwelling needle according to the present invention preferably has a plurality of gripping portions formed thereon, which are arranged in a point-symmetrical relationship with respect to the center of the upper body portion.

[0010] This makes it possible to make the indwelling needle easy to grasp with two fingers and easy to apply force when unlocking.

[0011] Furthermore, it is preferable that the lower body portion of the indwelling needle according to the present invention has a protrusion formed adjacent to the first engagement portion, and that the protrusion has an inclined portion that moves the upper body portion in the direction of the central axis of the lower body portion relative to the lower body portion as the upper body portion and the lower body portion rotate relative to each other.

[0012] This allows the indwelling needle to be assembled easily and reliably.

[0013] Furthermore, when the indwelling needle according to the present invention is rotated in a direction separating the assembled lower body portion and upper body portion, the second protrusion portion and the second engagement portion interfere with each other, and it is preferable that the interference area between the two is flat.

[0014] As a result, in the assembled state of the indwelling needle, the second protruding portion and the second engaging portion interfere with each other at their surfaces, thereby reliably preventing separation of the upper body portion and the lower body portion, which are constituent members.

[0015] Furthermore, the first protruding portion of the indwelling needle according to the present invention is preferably used for both movement of the upper body portion relative to the lower body portion in the direction of the central axis and rotation relative to the rotation direction.

[0016] This allows the first protrusion to serve as both a component for moving the upper body portion in the central axis direction relative to the lower body portion, and a component for rotating the upper body portion, resulting in a smaller indwelling needle than if each component were provided separately. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a front view of an indwelling needle according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory diagram showing the connection of the indwelling needle of FIG. 1 to a tube. [Figure 3] Front view of the upper body part of Figure 1. [Figure 4] FIG. 1 shows a top view of the upper body section. [Figure 5] Bottom view of the upper body part of Figure 1. [Figure 6] Section FF of the upper body part of Figure 4. [Figure 7] FIG. 2 is a perspective view of the lower body portion of FIG. 1. [Figure 8] Front view of the lower body part of Figure 1. [Figure 9] Top view of the lower body part of Figure 1. [Figure 10] FIG. 2 is an explanatory diagram showing the initial state when the upper body and the lower body of FIG. 1 are assembled. [Figure 11] 1. FIG. 4 is an explanatory diagram showing the engagement state of the third protruding portion and the second engagement portion of the indwelling needle of FIG. [Figure 12] FIG. 2 is a cross-sectional view showing the initial state of assembly of the upper body and the lower body of FIG. 1. [Figure 13] 2 is a cross-sectional view showing an intermediate state of assembly of the upper body and the lower body of FIG. 1. FIG. [Figure 14] 2 is a cross-sectional view showing the completed assembly of the upper body and lower body of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] <Example> The overall configuration of an indwelling needle according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a front view showing the indwelling needle. Figure 2 is an explanatory view showing a state in which a tube 50 is attached to the indwelling needle of Figure 1.

[0019] [Overall structure of the indwelling needle and how to use it] The indwelling needle according to the embodiment of the present invention comprises a lower body portion 20 and an upper body portion 60. When attaching the indwelling needle to the skin, the lower body portion 20 is attached to the skin, and then the upper body portion 60 is attached to the lower body portion 20. The outer needle 38 of the lower body portion 20 is inserted into the inner needle of an auxiliary member (not shown), and the outer needle 38 is then pierced through the skin. In this state, the lower surface 29 of the lower body portion 20 is fixed to the skin with tape.

[0020] The upper body 60 is connected to the tube 50 in advance. A connection terminal 51 provided at one end of the tube 50 is fitted into a central hole 63 (described later) provided on an outer flat surface 66 of the outer surface 61 of the upper body 60. The other end of the tube body 52 is connected to a portable pump (not shown).

[0021] With the tube 50 attached, the upper body 60 is mated with the corresponding surface of the lower body 20. The indwelling needle is assembled by rotating the mated two parts relative to each other and fixing them together. In the assembled state, the outer circumferential edge 68 of the upper body 60 and the outer circumferential edge 37 of the lower body 20 are in contact. Once the indwelling needle is attached and assembled as described above, the drug solution is administered. [Details of the indwelling needle]

[0022] The upper body 60 will be described with reference to Figures 3 to 6. Figures 3 to 5 are a front view, a top view, and a bottom view, respectively, of the upper body 60. Figure 6 is a cross-sectional view of the upper body 60 taken along line FF in Figure 4, showing the internal structure of the upper body 60.

[0023] The outer structure of the upper body 60 will be described with reference to Figures 3 and 4. The upper body 60 is a generally circular member having an outer peripheral end 68 and a protruding shape on the side opposite to the side that contacts the lower body 20. The upper body 60 has an outer surface 61 on the protruding side and an inner surface 67 on the opposite side. A circular outer flat surface 66 is provided in the central region of the outer surface 61. A central hole 63 is provided in the central region of the outer flat surface 66. The centers of the outer flat surface 66 and the central hole 63 coincide with the center P, which is the central position of the upper body 60. An outer peripheral surface 62 is formed from the outer periphery of the outer flat surface 66 to the outer peripheral end 68, connecting the outer periphery of the outer flat surface 66 to the outer peripheral end 68.

[0024] Approximately rectangular through holes 81, 82 are provided in each of the outer flat surface 66 and the outer peripheral surface 62. The through hole 81 is a hole required for mold molding to form a first protrusion 70 (described later), and the through hole 82 is a hole required for mold molding to form a third protrusion 73 (described later). The through holes 81, 82 are provided at two locations on the outer peripheral side of the outer flat surface 66 that are point-symmetric with respect to the center P. Furthermore, the outer peripheral surface 62 is provided with two through holes 82, 82 that are point-symmetric with respect to the center P. Of the two sets of through holes 81, 82, the first protrusions 70, 70 can be seen from above through one set of through holes 81, 81. Furthermore, the third protrusions 73, 73 can be seen from above through the other set of through holes 82, 82.

[0025] The upper body 60 is provided with a grip portion 64 and a notch 65. The notch 65 includes a radial notch formed in a substantially radial direction from the outer peripheral end 68 toward the center P of the upper body 60, and a circumferential notch formed in a substantially circumferential direction from the end of the radial notch on the center P side. The grip portion 64 is a substantially arc-shaped portion formed by the notch 65. As shown in FIG. 3 , the grip portion 64 has three ridges on its outer surface that act as anti-slip surfaces when the grip portion 64 is pressed with a finger. The notch 65 may have a shape other than the above. For example, the notch 65 may have a curved shape similar to the above shape, as long as the grip portion 64 can be formed into a substantially arc-shaped shape.

[0026] 5 and 6, the inner structure of the upper body 60 will be described. The inner surface of the upper body 60 is provided with a first protrusion 70, a second protrusion 75, and a third protrusion 73, which respectively engage with corresponding portions of the lower body 20. An inner flat surface 69 is provided on the outer periphery of the central hole 63 of the inner surface 67.

[0027] The first protrusions 70 are provided at two locations on the outer periphery of the inner flat surface 69, at positions point-symmetrical with respect to the center P. When viewed from above the upper body 60, the first protrusions 70 are arranged to overlap with substantially rectangular through-holes 81, 81 provided in the outer flat surface 66. Therefore, the user can visually recognize the first protrusions 70 from above through the through-holes 81, 81. Therefore, when assembling the upper body 60 to the lower body 20, the user can visually confirm the engagement between the first protrusions 70 and the corresponding parts of the lower body 20 with which the first protrusions 70 engage.

[0028] 6, the first protrusion 70 is a member with an L-shaped cross section that extends vertically downward from the outer periphery of the inner surface 67 of the upper body 60 and extends at its lower end toward the center P. The first protrusion 70 has a first upper surface 71 on its upper surface side and a first inner circumferential surface 72 on its inner surface side (toward the center P) at the portion formed by extending toward the center P of the lower end of the first protrusion 70.

[0029] As shown in FIG. 5, the second protrusion 75 is provided on the inner surface side of the grip portion 64. The second protrusion 75 is an elongated, arc-shaped member extending in the circumferential direction. The arc-shaped second protrusion 75 is arranged along the circumferential cutout portion of the notch 65. The second protrusion 75 and the first protrusion 70 are provided in pairs at positions point-symmetrical with respect to the center P of the upper body portion 60. The positional relationship between the second protrusion 75 and the first protrusion 70 will be described. The second protrusion 75 and the first protrusion 70 are adjacent to each other and arranged on the same radial line. In other words, when viewed outward from the center P, adjacent second protrusions 75 and first protrusions 70 are arranged so that at least a portion of them overlap.

[0030] The second protrusion 75 and the grip portion 64 are integrally connected. Therefore, when the grip portion 64 is pressed toward the center P with a finger, the second protrusion 75 is displaced radially together with the grip portion 64 as the grip portion 64 is displaced. The second protrusion 75 can easily and reliably lock the upper body portion 60 and the lower body portion 20 in the completed mating state after rotational mating. Furthermore, because the second protrusion 75 is displaced radially, the second protrusion will not rub against the mating member even when assembly and disassembly are repeated, and the second protrusion will not be scraped or deformed.

[0031] Because the displacement direction between the grip portion 64 and the second protruding portion 75 is the radial direction, there is no need to ensure space for the second protruding portion 75 to be displaced in the direction of the central axis P, as compared to other displacement directions, such as the direction of the central axis P. This allows the indwelling needle to be made thin, and therefore the user of the indwelling needle can use it without worrying about the indwelling needle protruding from the skin.

[0032] The second protruding portion 75 has a circumferential base end portion 76, a circumferential tip end portion 77, a tip protrusion portion 78, and a circumferential tip end face 79. The circumferential base end portion 76 of the second protruding portion 75 is arranged around the base end portion of the grip portion 64 which is located near the inner terminal end portion of the notch 65. Furthermore, the circumferential tip end portion 77 of the second protruding portion 75 is arranged around the terminal end portion of the grip portion 64. The circumferential tip end portion 77 is provided with a tip protrusion portion 78 which has a protruding shape formed facing outward. Furthermore, the circumferential tip end portion 77 is provided with a circumferential tip end face 79 which is the circumferential terminal end surface of the second protruding portion 75.

[0033] The third protrusion 73 is provided on the inner surface of the outer circumferential surface 62, more outer than the first protrusion 70, at approximately the same radial position as the second protrusion 75, and adjacent to the circumferential base end 76. The third protrusion 73 is arranged to overlap with a substantially rectangular through-hole 82 provided in the outer flat surface 66, when viewed from above the upper body 60. Therefore, the user can visually confirm the third protrusion 73 from above through the through-hole 82. Therefore, when assembling the upper body 60 to the lower body 20, the user can visually confirm the engagement between the third protrusion 73 and the corresponding portion of the lower body 20 with which the third protrusion 73 is fitted.

[0034] 6, the third protrusion 73 is a member having an L-shaped cross section that extends vertically downward from the outer periphery of the inner surface 67 of the upper body 60 and then extends outward at its lower end. The third protrusion 73 has a third upper surface 74 on the upper surface of the portion of the lower end of the third protrusion 73 that extends outward from the lower end.

[0035] The structure of the lower body 20 will be described with reference to Figures 7 to 9. Figures 7 to 9 are a perspective view, a front view, and a top view, respectively, of the lower body 20. The center P of the lower body 20 coincides with the center P of the upper body 60.

[0036] The lower body 20 is a generally circular member having an upper surface 21, a lower surface 29, and an outer peripheral edge 37. Two curved portions 36 are formed at positions point-symmetrical with respect to the center P of the outer peripheral edge 37, where the outer peripheral edge 37 is curved toward the center P. The upper surface 21 has a flat upper plane 28. The lower body 20 is cylindrical and has an outer needle 38 on its lower surface 29 that pierces the skin. When attaching the lower body 20 to the skin, a known auxiliary member (not shown) having an inner needle is used. The lower body 20 is attached by inserting the inner needle of the auxiliary member into the outer needle 38, and then piercing the skin with the outer needle 38 and the inner needle. After the lower body 20 is attached, the auxiliary member having the inner needle is removed. With the outer needle 38 piercing the skin, the lower surface 29 of the lower body 20 is fixed to the skin with tape.

[0037] The lower body 20 has a cylindrical portion 24 coaxial with the center P of the lower body 20, and a cylindrical portion 23 in the hollow portion inside the cylindrical portion 24. As shown in FIG. 8, the upper surface of the cylindrical portion 23 is formed higher than the upper end portion 22, which is the upper surface of the cylindrical portion 24. The outer diameter of the cylindrical portion 23 is slightly smaller than the inner diameter of the center hole 63 of the upper body 60. With this structure, when the upper body 60 is placed over the lower body 20, the cylindrical portion 23 fits into the center hole 63 with an annular gap. The connection terminal 51 of the tube 50 fits into the outer periphery of the cylindrical portion 23 through the center hole 63. An inclined surface 39 is formed on the outer periphery of the cylindrical portion 24. The inclined surface 39 connects the upper end portion 22 to the upper flat surface 28.

[0038] The lower body portion 20 is provided with a first mating portion 25, a second mating portion 30, and a protrusion 26, which are portions that are mated with the upper body portion 60, respectively.

[0039] The first engagement portions 25 are formed one by one at point-symmetric positions with respect to the center P on the inclined surface 39. The first engagement portions 25 are grooves into which the first protrusions 70 engage. The circumferential width of the first engagement portions 25 is approximately the same as the circumferential width of the first inner peripheral surface 72 of the first protrusions 70, and the length of the first engagement portions 25 in the direction of the central axis P is formed to be a predetermined length. When the upper body portion 60 is brought close to the surface corresponding to the lower body portion 20, the first inner peripheral surface 72 of the first protrusions 70 comes into contact with the surface of the first engagement portion 25. As the upper body portion 60 and the lower body portion 20 are brought closer, the first inner peripheral surface 72 moves over the surface of the first engagement portion 25 while contacting it. The first engagement portion 25 is formed into a curved surface, and the first inner peripheral surface 72 is formed into a curved surface that matches the curved surface of the surface of the first engagement portion 25.

[0040] The ribs 26 are formed one by one at point-symmetric positions with respect to the center P on the inclined surface 39. The ribs 26 are components that hold the upper body portion 60 and the lower body portion 20 close to each other in the direction of the central axis P when the upper body portion 60 and the lower body portion 20 are rotated relative to each other. The ribs 26 are arranged at the height of the upper end of the first mating portion 25. The ribs 26 are arc-shaped ribs that are formed on the outside of the cylindrical portion 24 and protrude radially outward for a predetermined circumferential length. Each rib 26 is formed at a circumferential angle range of approximately 30° to approximately 60°. Each of the two ribs 26 is provided adjacent to the right end of each of the first mating portions 25.

[0041] The lower surface of the rib protrusion 26 gradually changes in height. The lower surface of the rib protrusion 26 is formed with an inclined surface 27. The inclined surface 27 at the end of the rib protrusion 26 adjacent to the first engagement portion 25 is formed high and gradually decreases in height at least to the middle of the arc shape. The lower surface of the rib protrusion 26 is the surface that contacts the first upper surface 71 of the first protrusion 70. After the first inner peripheral surface 72 of the first protrusion 70 is pressed into a predetermined position in the first engagement portion 25 along the central axis P, when the upper body portion 60 rotates clockwise relative to the lower body portion 20, the first upper surface 71 of the first protrusion 70 moves while contacting the lower surface of the rib protrusion 26. When the first upper surface 71 moves while contacting the inclined surface 27, which is gradually decreased in height, the upper body portion 60 is guided toward the lower body portion 20 along the central axis P, similar to the effect of the threads of a screw. The first protrusion 70 can be used to move the upper body 60 in the central axis direction relative to the lower body 20 and rotate in the rotational direction, allowing for a smaller indwelling needle compared to when each component is arranged separately.

[0042] The second mating portions 30 are formed one by one at positions symmetrical about the center P on the outer peripheral edge 37. The second mating portions 30 are arranged at approximately the same circumferential angular position as the starting points of the protrusions 26. The second mating portions 30 have a second mating portion tip portion 31, a second mating portion base end portion 32, a second mating portion inner peripheral surface 33, a second mating portion recess 34, and a second mating portion end face 35. The second mating portions 30 are formed integrally with the lower body portion 20. The second mating portion tip portion 31 is tapered to facilitate insertion into the corresponding mating hole of the upper body portion 60. The second mating portion tip portion 31 has a second mating portion inner peripheral surface 33 formed on the surface of the second mating portion tip portion 31 on the center P side. The surface of the second mating portion base end 32 on the center P side is recessed outward from the second mating portion inner peripheral surface 33, which is the surface of the second mating portion tip end 31 on the center P side, forming a second mating portion recess 34. The length of the second mating portion recess 34 in the direction of the rotation axis P is slightly longer than the length of the third protrusion 73 with which it is mated, in the direction of the rotation axis P, so that the third protrusion 73 can be easily mated with the second mating portion recess 34. A second mating portion end surface 35, which is a flat surface, is formed on the right side of the rotation direction of the second mating portion 30. The second mating portion end surface 35 is a flat surface formed parallel to the radial direction.

[0043] 10 and 11, the mating of corresponding parts when assembling the upper body section 60 to the lower body section 20 will be described. FIG. 10 shows the initial position in which the upper body section 60 and the lower body section 20 are aligned in the rotational direction in order to assemble them. The first protrusion section 70 of the upper body section 60 and the first mating section 25 of the lower body section 20 are in the same rotational position. In this state, the upper body section 60 and the lower body section 20 are mated. The first protrusion section 70 and the first mating section 25 are mated, and the second mating section 30 is inserted into the corresponding hole in the upper body section 60.

[0044] 11 shows the state in which the third protrusion 73 and the second mating recess 34 of the second mating portion 30 are mated. When the upper body portion 60 rotates relative to the lower body portion 20, the third protrusion 73 approaches the second mating recess 34 as it rotates. Then, as the upper body portion 60 rotates further, the third protrusion 73 passes through the second mating recess 34 without interfering with the second mating portion 30. When the upper body portion 60 is in close contact with the lower body portion 20, as shown in FIG. 11, the third protrusion 73 can easily pass through the second mating recess 34 as it rotates.

[0045] However, when the upper body portion 60 is tilted relative to the lower body portion 20 and is not in tight contact with the lower body portion 20, the third protrusion 73 interferes with the second mating portion 30 and cannot pass through the second mating portion recess 34. In other words, the upper body portion 60 cannot rotate any further relative to the lower body portion 20. The third protrusion 73 and the second mating portion recess 34 of the second mating portion 30 are each provided in point-symmetric positions with respect to the center P. In other words, they are each located at both ends of the lower body portion 20 that are furthest from the center P. Therefore, if the upper body portion 60 and the lower body portion 20 are rotated relative to each other while the upper body portion 60 is tilted even slightly relative to the lower body portion 20, the third protrusion 73 will come into contact with the second mating portion 30 and will not be able to pass through the second mating portion recess 34. The state in which the upper body section 60 is tilted relative to the lower body section 20 refers to a state in which the central axes P of the upper body section 60 and the lower body section 20 do not coincide with each other. Alternatively, the outer plane 66 or the inner plane 69 of the upper body section 60 is not parallel to the upper plane 28 or the lower surface 29. By providing the third protrusion 73 and the second mating section 30 having the second mating section recess 34, it is possible to reduce the possibility of the upper body section 60 and the lower body section 20 being assembled in a tilted state.

[0046] [Assembly Instructions] Assembly of the upper body section 60 and the lower body section 20 will be described with reference to Figures 12 to 14. Figure 12 shows the initial position where the upper body section 60 and the lower body section 20 are aligned in the rotational direction. Figure 13 shows the intermediate position where the upper body section 60 has been rotated clockwise from the mated position. Figure 14 shows the completed position where assembly of the two sections has been completed after further rotation from Figure 13. Below, explanations will be given for each stage: 1. initial position, 2. intermediate position, and 3. completed position.

[0047] 1. Initial position (Fig. 12) When assembling the upper body 60 and the lower body 20, first, the upper body 60 and the lower body 20 are brought close together with the first protrusion 70 of the upper body 60 and the first mating portion 25 of the lower body 20 aligned in the same rotational direction. After the first inner circumferential surface 72 of the first protrusion 70 contacts the first mating portion 25, the upper body 60 is further pressed against the lower body 20 until it contacts the lower body 20.

[0048] 2. Middle position (Fig. 13) Next, the upper body 60 is rotated clockwise relative to the lower body 20. As the upper body 60 rotates relative to the lower body 20, the first upper surface 71 of the first protrusion 70 moves along the inclined surface 27 while contacting the lower surface of the ridge 26. As a result, the upper body 60 gradually comes into contact with the lower body 20. Meanwhile, the third protrusion 73 approaches the second mating portion 30 and passes through the second mating portion recess 34. As the upper body 60 rotates relative to the lower body 20, the second protrusion 75 approaches the second mating portion 30, and the circumferential base end 76 passes inside the second mating portion inner circumferential surface 33, which is the inner circumferential surface of the second mating portion tip 31. As the upper body 60 rotates further, the circumferential tip 77 approaches the second mating portion inner circumferential surface 33. The circumferential tip portion 77 approaches the inner surface 33 of the second mating portion, and the tip protrusion portion 78 contacts the inner surface 33 of the second mating portion, causing the second protrusion portion 75 to bend and the circumferential tip portion 77 to be displaced toward the radial center P.

[0049] 3. Completion position (Fig. 14) When the upper body 60 rotates relative to the lower body 20 to the rotation completion angle position, the circumferential tip 77 separates from the second mating portion inner circumferential surface 33, and the elastic force of the second protrusion 75 causes the circumferential tip 77 to move in the direction of arrow L and return to its original radial position. The circumferential tip end face 79 of the second protrusion 75 contacts the second mating portion end face 35 of the second mating portion 30, and the circumferential tip end face 79 and the second mating portion end face 35 come into surface contact. In other words, the circumferential tip end face 79 and the second mating portion end face 35 interfere with each other, and the circumferential tip end face 79 and the second mating portion end face 35 are in a locked state of contact at the surface, so even if a rotational force in the opposite direction acts on the upper body portion 60, the second protrusion 75 will not come out of the second mating portion recess 34, and the upper body portion 60 will be prevented from coming off the lower body portion 20.

[0050] [How to remove] Next, a method for removing the upper body section 60 from the lower body section 20 will be described. When the two holding sections 64, which are positioned point-symmetrically with respect to the center P, are pressed with fingers from both sides, the gripping sections 64 are displaced radially toward the center P. At the same time, the second protrusion 75 is displaced radially toward the center P. The tip protrusion 78 of the second protrusion 75 is displaced radially toward the center P, and the tip protrusion 78 is disengaged from the second mating section end face 35. This releases the lock between the second protrusion 75 and the second mating section 30. When the upper body section 60 is rotated counterclockwise relative to the lower body section 20 in this state, the first upper surface 71 of the first protrusion 70 contacts the lower surface of the ridge 26 and moves along the inclined surface 27 in the opposite direction from when the upper body section 60 was assembled, gradually separating the upper body section 60 from the lower body section 20. When the rotational angular positions of the upper body 60 and the lower body 20 return to their initial positions, the upper body 60 is removed from the lower body 20. In this way, the upper body 60 is removed from the lower body 20.

[0051] When the upper body 60 is removed from the lower body 20, such as for bathing, a protective cap (not shown) of a similar shape to the upper body 60 can be attached to the upper surface of the lower body 20. The protective cap attached to the lower body 20 has the same shape as the upper body 60, with some exceptions. The central hole 63 of the protective cap is closed to prevent the intrusion of foreign matter such as water and dust. The protective cap is configured so that it can be attached to and detached from the lower body 20 in the same way as the upper body 60. Therefore, the user can easily use the protective cap in the same way as the upper body 60.

[0052] With the above-described configuration, the indwelling needle of the present invention can reliably prevent the components from being scraped or deformed and from being separated when assembled. [Explanation of symbols]

[0053] 20 lower body part, 25 first mating part, 26 protrusion, 27 slope part, 30 second mating part, 27 grip part, 70 first protrusion part, 73 third protrusion part, 75 second protrusion part.

Claims

1. Upper body, and An indwelling needle having a lower body portion, The upper body portion has a first protrusion formed to protrude in a radial direction of the upper body portion and capable of being engaged with a first engagement portion of the lower body portion; a second protrusion provided on the grip portion formed on the upper body portion, the second protrusion engaging with the second engaging portion provided on the lower body portion when the upper body portion and the lower body portion are rotated relative to each other; The indwelling needle, wherein at least a portion of the second protrusion is displaceable in a radial direction of the upper body portion.

2. The indwelling needle according to claim 1 , wherein a plurality of the gripping portions are formed and are arranged in a point-symmetrical positional relationship with respect to the center of the upper body portion.

3. A protrusion is formed on the lower body portion adjacent to the first mating portion, 3. The indwelling needle according to claim 1, wherein the protrusion has an inclined portion that moves the upper body portion relative to the lower body portion in a direction of a central axis of the lower body portion as the upper body portion and the lower body portion rotate relative to each other.

4. The indwelling needle according to any one of claims 1 to 3, wherein when the lower body portion and the upper body portion are rotated in a direction to separate them from their assembled state, the second protruding portion and the second engaging portion interfere with each other, and the interference portion between them is flat.

5. The indwelling needle according to any one of claims 1 to 4, wherein a third protrusion is provided on the upper body portion, the third protrusion coming into contact with the second engagement portion when the upper body portion and the lower body portion are rotated relative to each other in a state in which the central axes of the upper body portion and the lower body portion do not coincide after the first protrusion is engaged with the first engagement portion.

6. The indwelling needle according to any one of claims 1 to 5, wherein the first protrusion is used for both movement of the upper body portion relative to the lower body portion in a central axis direction and rotation relative to a rotation direction.

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