JP7797777B2 - indwelling needle - Google Patents

Description

The present invention relates to an indwelling needle that continuously injects a medicinal solution.

As disclosed in Patent Document 1, an indwelling needle is used to continuously inject minute amounts of medicinal liquid using a portable pump. In addition to the type of indwelling needle disclosed in Patent Document 1, thin, circular indwelling needles are also known. Some indwelling needles of this type 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.

In the above-mentioned rotary engagement structure, when the upper body part placed over the lower body part is rotated, the claw part on the upper body part passes over the protrusion on the upper surface of the lower body part, and the claw part reaches the rotation completion position, completing assembly. The user of the indwelling needle can tell that assembly is complete by the click feeling that occurs when the claw part passes over the protrusion. The protrusion holds the claw part in the rotation completion position, and the upper and lower body parts are maintained as a single unit without coming apart. Furthermore, when removing the upper body part, it can be rotated in the opposite direction to that used during assembly, allowing the claw part to pass over the protrusion and remove it.

Japanese Patent Application Laid-Open No. 2019-088725

However, with repeated assembly and removal, the claws rub against the protrusions each time they pass over them, causing the protrusions to become worn or deformed. When the protrusions become worn or deformed, the clicking sensation disappears, reducing the rotational resistance in the removal direction, and potentially causing the upper body to come off the lower body.

The present invention was made to solve the above problems, and aims to provide an indwelling needle that reliably prevents separation of components when assembled, without causing chipping or deformation of the components.

The indwelling needle according to the present invention comprises a lower body and an upper body. The upper body has a first protrusion formed to protrude radially from the upper body and engageable with a first engagement portion of the lower body, and a second protrusion provided on a grip formed on the upper body and engaging with a second engagement portion provided on the lower body when the upper and lower bodies are rotated relative to one another, and at least a portion of the second protrusion is displaceable radially from the upper body.

With the indwelling needle according to the present invention, even if it is repeatedly assembled and removed, the second protruding portion, which is a constituent member, is not worn or deformed, and separation of the constituent members in the assembled state can be reliably prevented.

Furthermore, it is preferable that the indwelling needle according to the present invention has multiple gripping portions, which are arranged in a point-symmetrical relationship with respect to the center of the upper body portion.

This makes the indwelling needle easy to grasp with two fingers and easy to apply force when unlocking.

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

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

Furthermore, when the indwelling needle according to the present invention is rotated in a direction that separates the assembled lower body and upper body, the second protruding portion and the second engaging portion interfere with each other, and it is preferable that the interference area between the two be flat.

As a result, when the indwelling needle is assembled, the second protrusion and second engagement portion interfere with each other at their surfaces, reliably preventing separation of the upper and lower body components.

Furthermore, it is preferable that the first protrusion of the indwelling needle according to the present invention be used for both movement of the upper body portion relative to the lower body portion in the central axis direction and rotation in the rotational direction.

This allows the first protrusion to function as both a component for moving the upper body in the direction of the central axis relative to the lower body, and a component for rotating the upper body, resulting in a smaller indwelling needle compared to when each component is provided separately.

FIG. 1 is a front view of an indwelling needle according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing the connection of the indwelling needle of FIG. 1 to a tube. FIG. 2 is a front view of the upper body portion of FIG. 1; FIG. 2 is a top view of the upper body portion of FIG. 1; FIG. 2 is a bottom view of the upper body portion of FIG. 1 . 5 is a cross-sectional view of the upper body portion of FIG. 4 taken along line FF. FIG. 2 is a perspective view of the lower body portion of FIG. 1 . FIG. 2 is a front view of the lower body portion of FIG. 1 . FIG. 2 is a top view of the lower body portion of FIG. 1 . FIG. 2 is an explanatory diagram showing the initial state when the upper body and the lower body of FIG. 1 are assembled. FIG. 2 is an explanatory diagram showing the engagement state of the third protruding portion and the second engagement portion of the indwelling needle of FIG. 1 . FIG. 2 is a cross-sectional view showing the initial state of assembly of the upper body and the lower body of FIG. 1 . 2 is a cross-sectional view showing an intermediate state of assembly of the upper body and the lower body of FIG. 1; FIG. 2 is a cross-sectional view showing the completed assembly of the upper body and the lower body of FIG. 1; FIG.

<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 of 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.

[Overall configuration of indwelling needle and method of use]
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 an 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.

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 below) provided on the 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).

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 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.
[Detailed configuration of indwelling needle]

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

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 with an outer peripheral edge 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 edge 68, connecting the outer periphery of the outer flat surface 66 to the outer peripheral edge 68.

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 the first protrusion 70 (described below), and the through-hole 82 is a hole required for mold molding to form the third protrusion 73 (described below). The through-holes 81, 82 are provided at two locations on the outer peripheral side of the outer flat surface 66 that are point-symmetrical with respect to the center P. Furthermore, the outer peripheral surface 62 has two through-holes 82, 82 that are point-symmetrical with respect to the center P. Of the two sets of through-holes 81, 82, the first protrusions 70, 70 are visible from above through one set of through-holes 81, 81. Furthermore, the third protrusions 73, 73 are visible from above through the other set of through-holes 82, 82.

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 edge 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 closer to the center P. 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 a non-slip surface 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.

The internal structure of the upper body 60 will be described with reference to Figures 5 and 6. The inside of the upper body 60 is provided with a first protrusion 70, a second protrusion 75, and a third protrusion 73, which each mate with corresponding portions of the lower body 20. An inner flat surface 69 is provided on the outer periphery of the central hole 63 on the inner surface 67.

The first protrusions 70 are provided at two locations on the outer periphery of the inner flat surface 69, symmetrically about the center P. When viewed from above the upper body 60, the first protrusions 70 are positioned so as to overlap with the roughly rectangular through-holes 81, 81 provided in the outer flat surface 66. This allows the user to view 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 fit between the first protrusions 70 and the corresponding parts of the lower body 20 with which they fit.

As shown in Figure 6, the first protrusion 70 is an L-shaped cross-section member that extends vertically downward from the outer periphery of the inner surface 67 of the upper body 60 and extends toward the center P at its lower end. At the portion of the lower end of the first protrusion 70 that extends toward the center P, the first protrusion 70 has a first upper surface 71 on its upper surface and a first inner circumferential surface 72 on its inner surface (toward the center P).

As shown in FIG. 5, the second protrusion 75 is provided on the inner surface 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 explained. The second protrusions 75 and the first protrusions 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 each overlap.

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 displaces radially together with the grip portion 64 as the grip portion 64 displaces. 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 displaces radially, repeated assembly and disassembly do not cause the second protrusion to rub against the mating member, and the second protrusion will not be worn or deformed.

By displacing the gripping portion 64 and the second protruding portion 75 in the radial direction, there is no need to secure space for the second protruding portion 75 to displace in the direction of the central axis P, as opposed to displacing in other directions, such as the direction of the central axis P. This allows the indwelling needle to be constructed thin. Therefore, the user of the indwelling needle can use the indwelling needle without worrying about the needle protruding from the skin.

The second protrusion 75 has a circumferential base end 76, a circumferential tip end 77, a tip protrusion 78, and a circumferential tip end face 79. The circumferential base end 76 of the second protrusion 75 is located around the base end of the gripping portion 64, which is located near the inner end of the notch 65. The circumferential tip end 77 of the second protrusion 75 is located around the tip of the gripping portion 64. The circumferential tip end 77 is provided with a tip protrusion 78 that protrudes outward. The circumferential tip end 77 is also provided with a circumferential tip end face 79, which is the circumferential end face of the second protrusion 75.

The third protrusion 73 is located on the inner surface of the outer circumferential surface 62, further outward than the first protrusion 70, at approximately the same radial position as the second protrusion 75, and adjacent to the circumferential base end 76. When viewed from above the upper body 60, the third protrusion 73 is positioned so as to overlap with a substantially rectangular through-hole 82 located in the outer plane 66. This allows the user to view 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 fit between the third protrusion 73 and the corresponding portion of the lower body 20 with which it fits.

As shown in FIG. 6, the third protrusion 73 is an L-shaped cross-section member that extends vertically downward from the outer periphery of the inner surface 67 of the upper body 60 and 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.

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.

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. As is well known, an auxiliary member (not shown) having an inner needle is used to attach the lower body 20 to the skin. 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.

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 Figure 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 onto the outer surface 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.

The lower body portion 20 has a first mating portion 25, a second mating portion 30, and a protrusion 26, which are portions that mating with the upper body portion 60.

The first engagement portions 25 are formed one by one at positions point-symmetrical 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 along the surface of the first engagement portion 25 while remaining in contact with it. The first engagement portions 25 are 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 first engagement portion 25.

The ribs 26 are formed one by one at positions point-symmetrical 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 two are rotated relative to each other. The ribs 26 are positioned at the height of the upper end of the first mating portion 25. The ribs 26 are arc-shaped ribs that protrude radially outward for a predetermined circumferential length on the outside of the cylindrical portion 24. Each rib 26 is formed over a circumferential angle range of approximately 30° to approximately 60°. Each of the two ribs 26 is located adjacent to the right end of each of the first mating portions 25.

The lower surface of the rib projection 26 has a gradually changing height. The lower surface of the rib projection 26 is formed with an inclined surface 27. The inclined surface 27 at the end of the rib projection 26 adjacent to the first engagement portion 25 is formed high and gradually lowers at least to the midpoint of the arc shape. The lower surface of the rib projection 26 is the surface that comes into contact with 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 projection 26. When the first upper surface 71 moves while contacting the inclined surface 27, which is formed to gradually lower, the upper body portion 60 is guided toward the lower body portion 20 along the central axis P, due to the same effect as the threads of a screw. The first protrusion 70 can be used to move the upper body 60 in the direction of the central axis relative to the lower body 20, and to rotate in the direction of rotation, allowing for a smaller indwelling needle compared to when each component is arranged separately.

The second engagement portions 30 are formed one by one at positions point-symmetrical with respect to the center P on the outer peripheral edge 37. The second engagement portions 30 are arranged at approximately the same circumferential angular position as the starting point of the protrusion 26. The second engagement portions 30 have a second engagement portion tip portion 31, a second engagement portion base end portion 32, a second engagement portion inner peripheral surface 33, a second engagement portion recess 34, and a second engagement portion end face 35. The second engagement portions 30 are formed integrally with the lower body portion 20. The second engagement portion tip portion 31 is tapered to facilitate insertion into the corresponding engagement hole of the upper body portion 60. The second engagement portion tip portion 31 has a second engagement portion inner peripheral surface 33 formed on the surface of the second engagement portion tip portion 31 facing the center P. The surface of the second mating portion base end 32 facing the center P is recessed outward from the second mating portion inner peripheral surface 33, which is the surface of the second mating portion tip end 31 facing the center P, 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 fits, so that the third protrusion 73 can easily fit into the second mating portion recess 34. A flat second mating portion end surface 35 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.

Referring to Figures 10 and 11, we will explain how corresponding parts fit together when assembling the upper body section 60 to the lower body section 20. Figure 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 fit together, and the second mating section 30 is inserted into the corresponding hole in the upper body section 60.

Figure 11 shows the state in which the third protrusion 73 and the second mating portion 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 portion recess 34 as it rotates. Then, as the upper body portion 60 rotates further, the third protrusion 73 passes through the second mating portion recess 34 without interfering with the second mating portion 30. When the upper body portion 60 is in tight contact with the lower body portion 20, as shown in Figure 11, the third protrusion 73 can easily pass through the second mating portion recess 34 as it rotates.

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

[Assembly method]
Assembly of the upper body 60 and the lower body 20 will be described with reference to Figures 12 to 14. Figure 12 shows the initial position where the upper body 60 and the lower body 20 are aligned in the rotational direction. Figure 13 shows an intermediate position where the upper body 60 has been rotated clockwise from the mated position. Figure 14 shows the completed position where assembly of the two has been completed after further rotation from Figure 13. Each stage, 1. initial position, 2. intermediate position, and 3. completed position, will be described below.

1. Initial position (Figure 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 position. 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.

2. Intermediate position (Figure 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 77 approaches the inner surface 33 of the second mating portion, and the tip protrusion 78 comes into contact with the inner surface 33 of the second mating portion, causing the second protrusion 75 to bend and the circumferential tip 77 to be displaced toward the radial center P.

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 with each other. 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 contact with each other at the surface, resulting in a locked state. Therefore, 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.

[How to remove]
Next, a method for removing the upper body 60 from the lower body 20 will be described. When the two holding portions 64, which are positioned point-symmetrically with respect to the center P, are pressed with fingers from both sides, the gripping portions 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 disengages from the second mating portion end surface 35. This releases the locked state between the second protrusion 75 and the second mating portion 30. When the upper body 60 is rotated counterclockwise relative to the lower body 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 that during assembly, gradually separating the upper body 60 from the lower body 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 manner, the upper body 60 is removed from the lower body 20.

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 top 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 protective cap has a closed central hole 63 to prevent the entry of foreign matter such as water and dust. The protective cap is designed to 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.

The indwelling needle of the present invention, thanks to its configuration, can reliably prevent the components from being scraped or deformed and from separating when assembled.

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

Claims (6)

An indwelling needle comprising an upper body portion and 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, and a second protrusion provided on a grip 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;
The indwelling needle, wherein at least a portion of the second protrusion is displaceable in a radial direction of the upper body portion. The indwelling needle according to claim 1, wherein the gripping portions are formed in multiple positions and are arranged in point symmetry with respect to the center of the upper body portion. 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. 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 protrusion portion and the second engagement portion interfere with each other, and the interference area between them is flat. The indwelling needle according to any one of claims 1 to 4, wherein the upper body portion is provided with a third protrusion that comes 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. 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 the central axis direction and rotation relative to the rotation direction.