JP2021053222A - Indwelling needle - Google Patents

Abstract

To provide a technology that improves the accuracy of operation of a device when the indwelling needle is contained in the device.SOLUTION: An indwelling needle 51 includes: a hollow needle 52; a body 53 having a hollow portion capable of containing the needle; a hub 55 for supporting the needle and arranged in the inside of the body, and capable of moving in the hollow portion from a first position where the needle is protruded out of an opening of the body to a second position where the needle is contained in the body; a coil spring 59 for biasing the hub in a direction going from the first position to the second position; and an engaging mechanism for engaging the hub with the body in the first position and the second position. The engaging mechanism has: an engagement part 57 provided at the hub and extending in the direction apart from a central axis 60; a first engaged hole 58 provided at the side of the body and engaged with the engagement part in the first position; and a second engaging hole 61 engaged with the engagement part in the second position. A distance from the central axis to the second engaging hole is shorter than the distance from the central axis to the first engaging hole.SELECTED DRAWING: Figure 1

Description

The present invention relates to an indwelling needle that is punctured and placed in a blood vessel and has a safety mechanism in particular.

Indwelling needles used for infusion and blood collection have been developed (for example, Patent Document 1).

U.S. Pat. No. 5,779,679

However, in the case of the indwelling needle 1 as shown in Patent Document 1, a force always acts from the spring 15 to the needle holding portion 14 in the state shown in FIG. Therefore, for example, when the needle holding portion 14 shifts from the state of FIG. 1 to the state of FIG. 2, a force for bending the protrusion 40 in a direction approaching the central axis of the needle 16 always acts on the protrusion 40. Therefore, it is conceivable that the extending portion of the U-shaped arm 38 extending from the main body of the needle holding portion 14 is plastically deformed so as to approach the central axis.

When the extending portion is plastically deformed in this way, the state of FIG. 1 of Patent Document 1 shifts to the state of FIG. 2 of Patent Document 1, and when the protrusion 40 invades the opening 48, the protrusion 40 is at the center. It is conceivable that it does not return sufficiently in the direction away from the axis. Therefore, it is assumed that the amount of engagement between the protrusion 40 and the opening 48 becomes small. In such a case, the protrusion 40 is not locked at the opening 48 as desired, and the needle 16 may fall out of the opening 23 of the body 12. As a result, it may be difficult to reliably accommodate the needle 16 in the body 12.

Therefore, it is an object of the present invention to provide a technique for improving the accuracy of operation of the safety mechanism in an indwelling needle having a safety mechanism for accommodating a needle exposed from the tip inside.

The present invention employs the following configuration in order to solve the above-mentioned problems.

That is, the indwelling needle according to one aspect of the present invention supports the hollow needle, the accommodating portion which is a substantially tubular member having a hollow portion capable of accommodating the hollow needle, and the base end of the hollow needle and accommodating the hollow needle. A second position in which the hollow needle is accommodated in the hollow portion of the accommodating portion from a first position in which the hollow needle protrudes from an opening of the hollow portion at one end of the accommodating portion. A moving member that can move the hollow portion up to, a spring that urges the moving member in a direction from the first position to the second position, and the moving member at the first position and the second position. The engaging mechanism is provided on the moving member and extends in a direction away from the central axis, and is provided on the side surface of the housing portion. It has a first engaged portion that engages with the engaging portion at the first position and a second engaged portion that engages with the engaging portion at the second position. The distance from the central axis to the second engaged portion is shorter than the distance from the central axis to the first engaged portion, which is an indwelling needle.

According to this configuration, it is possible to secure a sufficient amount of engagement when the engaging portion engages with the second engaged portion while suppressing the load on the engaging portion at the first position. Therefore, when the hollow needle moves from the first position protruding from the opening of the hollow portion to the second position accommodated in the hollow portion, the engaging portion is more reliably engaged with the second engaged portion. The probability that the hollow needle is accommodated in the accommodating portion is improved.

In the indwelling needle according to the one side surface, the surface of the second engaged portion facing the base end surface of the engaging portion has a surface extending in a direction approaching the central axis toward the tip of the hollow needle, and the engaging portion. The proximal surface may engage the second engaged portion at the second position.

According to this configuration, the situation where the engaging portion moves beyond the second position in the proximal direction is further reduced.

In the indwelling needle according to the one side surface, the first engaged portion or the facing surface of the second engaged portion facing the base end surface of the engaging portion has a convex portion extending toward the tip end, and the engaging portion has a convex portion. The concave portion corresponding to the convex portion may be provided on the base end surface of the engaging portion.

According to this configuration, since the engaging portion is fixed by the unevenness, it is possible to prevent the engaging portion from being deformed in the direction approaching the central axis due to the spring pressure at the first position. Further, in the second position, it is prevented that the engaging portion bends in the direction approaching the central axis and the engagement with the second engaged portion is disengaged.

In the indwelling needle according to the one side surface, the facing surface of the first engaged portion facing the engaging portion base end surface extends in the direction approaching the central axis and the tip direction, and the engaging portion base end surface of the engaging portion is It may be engaged with the facing surface.

According to this configuration, since the engaging portion comes into surface contact with the first engaged portion, the spring pressure can be received on the surface, and the engaging portion is deformed or damaged due to the constant spring pressure. To reduce.

In the indwelling needle according to the one side surface, the distance between the inner wall of the accommodating portion and the central axis between the first engaged portion and the second engaged portion is at least a part of the distance between the first engaged portion and the center. It may be longer than the distance to the shaft and longer than the distance between the second engaged portion and the central shaft.

According to this configuration, it is possible to reduce the sliding resistance when the engaging portion moves in the accommodating portion.

In the indwelling needle according to the one side surface, the free end of the engaging portion may have a shape in which the tip end side protrudes in a direction away from the central axis.

According to this configuration, it is possible to reduce the feeling of resistance when the engaging portion slides in the accommodating portion.

In the indwelling needle according to the one side surface, the tip wall of the engaging portion may have a shape protruding toward the tip side toward the direction away from the central axis.

According to this configuration, it is possible to make it difficult for the engaging portion to come into contact with the shaft of the hollow needle and the moving member when the engaging portion moves in the direction approaching the central axis.

Further, the indwelling needle according to one aspect of the present invention supports the hollow needle, the accommodating portion which is a substantially tubular member having a hollow portion capable of accommodating the hollow needle, and the base end of the hollow needle. A second position in which the hollow needle is accommodated in the hollow portion of the accommodating portion from a first position which is arranged inside the accommodating portion and in which the hollow needle protrudes from an opening of the hollow portion at one end of the accommodating portion. A moving member that can move the hollow portion to a position, a spring that urges the moving member in a direction from the first position to the second position, and the moving member at the first position and the first position. An engaging mechanism for engaging with the accommodating portion at two positions is provided, and the engaging mechanism is provided on the moving member and extends in a direction away from the central axis, and on a side surface of the accommodating portion. It has a first engaged portion that is provided and engages with the engaging portion at the first position, and a second engaged portion that engages with the engaging portion at the second position. On the side surface of the accommodating portion having an angle with the side surface provided with the first engaged portion and the second engaged portion, along the direction from the first position to the second position. It may be an indwelling needle provided with a notch.

According to this configuration, by providing the notch, when the moving member moves in the accommodating portion, the wall surface in contact with the moving member tends to bend in the direction away from the central axis. Therefore, when the moving member slides, the frictional resistance that the moving member receives from the wall surface of the accommodating portion is reduced. Therefore, the sliding portion is smoothly moved from the first position to the second position. Further, the urging force of the spring that urges the moving member in the moving direction can be reduced. Therefore, it is possible to prevent the first engaged portion and the engaging portion that engages with the second engaged portion of the accommodating portion provided on the moving member from being deformed by the constant spring pressure. As a result, it is possible to improve the accuracy of the operation of the safety mechanism in the indwelling needle.

In the indwelling needle according to the one side surface, at least a part of the inner wall of the side surface with which the engaging portion abuts in the accommodating portion separates from the central axis as it goes from the first position to the second position. It may have an inclined surface that inclines in the direction.

According to this configuration, since the inner wall of the accommodating portion spreads smoothly, the frictional resistance received by the moving member from the inner wall on the side surface of the accommodating portion when the moving member moves from the first position to the second position is reduced. To. Therefore, the sliding portion is smoothly moved from the first position to the second position. Further, when the moving member is urged in the moving direction, the urging force can be reduced.

In the indwelling needle according to the one side surface, the moving member further has a guide portion that protrudes in a direction away from the central axis or is recessed in a direction approaching the central axis, and the accommodating portion is a guided portion that engages with the guide portion. It may have more parts.

According to this configuration, when the engaging portion disengaged from the first engaged portion moves to the second engaged portion, the moving member can be smoothly moved without rattling, and the engaging portion can be moved to the second. It can be reliably guided to the engaged portion.

In the indwelling needle according to the one side surface, the moving member may further have a rib that prevents the moving member from moving relative to the accommodating portion in the tip direction at the first position.

According to this configuration, it is possible to prevent the moving member from moving relative to the accommodating portion in the tip direction from the first position without going through the engaging portion.

According to the present invention, it is possible to improve the accuracy of the operation of the device when the needle exposed from the tip of the indwelling needle is housed in the device.

FIG. 1 shows an example of an outline of the indwelling needle according to the embodiment. (A) schematically illustrates a front view and a side view of the indwelling needle. (B) is an example of the cross-sectional view taken along the line AA in (A). FIG. 2 schematically illustrates an example of an outline of the body. (A) shows an example of the perspective view of the body. (B) shows an example of the cross-sectional view taken along the line AA in FIG. 2 (A) as an example of the cross-sectional view of the body. FIG. 2C shows a cross-sectional view taken along the line BB in FIG. 2A as an example of a cross-sectional view of the body. FIG. 3 shows a partially enlarged view of the vicinity of the engaging portion. FIG. 4 shows an outline of the rib. FIG. 4A shows a perspective view of a hub provided with ribs. FIG. 4B shows a top view of a hub provided with ribs. FIG. 4C shows a cross-sectional view of a hub provided with ribs in a body. FIG. 5 shows an example of a procedure for releasing the initial state of the indwelling needle shown in FIG. 1 and accommodating the needle in the body. (A) illustrates the front view of the indwelling needle. (B) shows the cross-sectional view in (A). FIG. 6 shows an example of an outline of the locked state. (A) illustrates the front view of the indwelling needle. (B) shows the cross-sectional view in (A). FIG. 7 shows an example of an outline of the indwelling needle according to the modified example. (A) exemplifies the front view and the side view of the indwelling needle. (B) shows the cross-sectional view taken along the line AA in (A).

Hereinafter, embodiments of the present invention will be described. The embodiments shown below are examples of embodiments of the present invention, and the technical scope of the present invention is not limited to the following embodiments.

<Device configuration>
FIG. 1 shows an example of the configuration of the indwelling needle 51 according to the embodiment of the present invention. FIG. 1A is a front view and a side view of the indwelling needle 51. Further, FIG. 1 (B) is a cross-sectional view taken along the line AA in FIG. 1 (A). As shown in FIG. 1, the indwelling needle 51 includes a hollow needle 52, a body 53 that accommodates the needle 52, and a hub 55 that is arranged inside the body 53 and holds the base end of the needle 52. Be prepared. Here, the body 53 is an example of the "accommodation portion" of the present invention. The hub 55 is an example of the "moving member" of the present invention. Hereinafter, in the indwelling needle 51, the left side in FIG. 1 is also referred to as the front end side, and the right side is also referred to as the rear end side. Further, the vertical direction in FIG. 1B is also referred to as an upper side and a lower side, respectively. Further, the back side perpendicular to the paper surface in FIG. 1 is also referred to as a right side, and the front side perpendicular to the paper surface is also referred to as a left side. Further, the state of the indwelling needle at the time of use in FIG. 1 is hereinafter also referred to as an initial state. Further, the state in which the needle 52 is housed in the body 53 after the initial state of FIG. 5 (described later) is released is also referred to as a locked state hereafter.

FIG. 2 schematically illustrates an example of an outline of the body 53 forming the indwelling needle 51. FIG. 2A shows a perspective view of the body 53. Further, FIG. 2B shows a cross-sectional view taken along the line AA in FIG. 2A as an example of a cross-sectional view of the body 53. Further, FIG. 2C shows a cross-sectional view taken along the line BB in FIG. 2A as an example of a cross-sectional view of the body 53. As shown in FIG. 2, the body 53 has a cylindrical tip portion 53A and a hollow portion communicating with the hollow portion of the tip portion 53A, from the main body portion 53B located on the rear end side of the tip portion 53A. It is formed. The main body portion 53B is a tubular portion having a substantially rounded rectangular cross section when viewed from the axial direction. Here, when the indwelling needle 51 is used, the body 53 is fixed to the skin so that the lower part of the body 53 in FIG. 2C is in contact with the skin of the patient. By being fixed in this way, the step between the needle and the skin when the body 53 is fixed to the skin can be reduced, and the adverse effect of the metal needle on the blood vessel can be reduced. Further, as shown in FIG. 2C, the flat lower surface of the body 53 contributes to stabilization when the body 53 is fixed to the skin. Further, the curved surface (R-shaped) of the side surface of the body 53 suppresses damage to the skin. Further, both ends of the body 53 in the direction along the central axis 60 are open. The opening 54 on the tip end side of the openings at both ends is provided so that the tip portion 55A of the hub 55 holding the needle 52 and the base end of the needle 52 can pass through.

Further, the body 53 includes a first engaging hole 58 that engages with an engaging portion 57 (described later) of the hub 55 and makes the needle 52 stationary in a state where the needle 52 protrudes from the opening 54. The first engaging hole 58 is provided on the tip end side of the main body 53B and on the upper and lower surfaces with respect to the central axis 60. Further, as shown in FIG. 2B, the base end surface 70 forming the first engaging hole 58 extends in the direction approaching the central axis 60 and in the direction toward the tip end of the body 53. Further, the base end surface 70 is provided with a convex portion 72 extending toward the tip end direction of the body 53. Here, the base end surface 70 is an example of the "first engaged portion" of the present invention, and the first engaging hole 58 includes the "first engaged portion" of the present invention. It should be noted that the convex portion may be provided to form a portion facing the base end surface of the engaging portion, or the groove may be provided to form the facing portion to the base end surface of the engaging portion. Further, the base end surface 70 is an example of the "opposing surface facing the engaging portion base end surface of the first engaged portion" of the present invention.

Further, the body 53 is provided with a second engaging hole 61 on the moving direction side with respect to the first engaging hole 58. The base end surface 73 forming the second engaging hole 61 extends in the direction of the central axis 60 toward the tip of the body 53. Further, the base end surface 73 may be provided with a convex portion similar to the convex portion 72 provided on the base end surface 70. Here, the base end surface 73 is an example of the "second engaging portion" of the present invention, and the second engaging hole 61 includes the "second engaged portion" of the present invention. Further, the base end surface 73 is an example of the "facing surface of the second engaged portion with the engaging portion base end surface" of the present invention.

More specifically, the second engaging hole 61 is provided on the rear end side of the main body 53B and on the upper and lower surfaces with respect to the central axis 60 direction. The first engagement hole 58 and the second engagement hole 61 penetrate the upper and lower walls of the body 53. Further, the first engagement hole 58 and the second engagement are made so that the distance X between the second engagement hole 61 and the central shaft 60 is shorter than the distance Y between the first engagement hole 58 and the central shaft 60. The hole 61 is provided.

Further, the body 53 includes a notch 65 formed along the moving direction between the first engaging hole 58 and the second engaging hole 61. The cutouts 65 are located on both sides (the left and right surfaces of the body 53) of the two first engaging holes 58 and the two second engaging holes 61, as shown in FIG. 2C. In total, four are provided.

Further, in the present embodiment, the first engaging hole 58 and the second engaging hole 61 are provided so as to open in the vertical direction on the arcuate surface in the outer shape of the rounded rectangle of the main body 53B. The notch 65 is provided on a surface having an angle (an angle around the central axis of the body 53) on the surface on which the first engaging hole 58 and the second engaging hole 61 are provided. More specifically, it is an arcuate surface that sandwiches the (opened) surface on which the first engagement hole 58 and the second engagement hole 61 are provided, and is provided on a surface closer to the portion having a linear outer shape. ing. Further, the notch 65 may be opened so that its axis is perpendicular to the outer shape of the main body portion 53B, or the notch 65 may have an axis perpendicular to the normal of the first engaging hole 58 and the second engaging hole 61. It may be open to hold.

In addition, in FIG. 2A, the first engaging hole 58 and the second engaging hole 61 appear to be provided on different surfaces of the outer shape of the body 53, but both of them are in the vertical direction in FIG. It is open and is provided on the same surface. However, in the present invention, the surfaces on which the first engagement hole and the second engagement hole are provided do not have to be exactly the same surface, and when both are provided on slightly different surfaces, the first engagement is performed. The surface on which the hole and the second engaging hole are provided means a surface included in the region determined by these two surfaces.

Further, the body 53 includes a pressing arm 66 that branches from the main body and presses the engaging portion 57 in a direction approaching the central axis 60 of the body 53. Here, the pressing arm 66 is an example of the "pressing member" of the present invention, and can be bent in a direction approaching the central axis 60 with the connecting portion 62 with the body 53 as a fixed end. Further, the tip of the pressing arm 66 is provided with a pressing portion 64 projecting in a direction approaching the central axis 60. The pressing portion 64 is displaced in the direction approaching the central axis 60 by bending the pressing arm 66 in the direction approaching the central axis 60.

Further, the engaging portion 57 comes into contact with the inner side surface 68 of the main body portion 53B of the body 53 when moving (details will be described later), but the moving direction is provided in a part of the region on the tip end side of the inner side surface 68. An inclined surface 67 is formed that inclines in a direction away from the central axis 60 toward the direction of the central axis 60. The distance between the central shaft 60 and the inner surface 68 is longer than the distance between the base end wall of the first engaging hole 58 and the central shaft 60 and the distance between the base end wall of the second engaging hole 61 and the central shaft 60. .. Further, in the shape of the body 53, the distance between the central shaft 60 and a part of the inner side surface 68 is based on the distance between the first engaging hole 58 and the central shaft 60 and the distance between the second engaging hole 61 and the central shaft 60. May also have a long shape.

On the other hand, as shown in FIG. 1, the hub 55 is a hollow member that extends in the moving direction and has both ends open in that direction. The hub 55 includes a tip portion 55A that is located on the tip side and supports the needle 52, a main body portion 55B that is located on the rear end side of the tip portion 55A, and a rear end portion 55C that is further located on the rear end side of the main body portion 55B. Formed from and. Then, the needle 52 is fixed to the hub 55 with its base end portion fitted into the opening of the tip portion 55A of the hub 55. That is, the hollow portion of the hub 55 and the hollow portion of the needle 52 communicate with each other. By communicating the needle 52 and the hub 55 in this way, for example, by supplying the chemical solution from the rear end portion 55C of the hub 55, the chemical solution is supplied into the patient's body through the hollow portion of the hub 55 and the needle 52. Will be done.

Further, the hub 55 includes a flexible extending portion 56 that branches from the main body portion 55B and extends toward the tip end. The tip of the extending portion 56 is provided with an engaging portion 57 that protrudes in a direction away from the central axis 60 and can engage with the first engaging hole 58 and the second engaging hole 61. Here, the engaging portion 57 can be located farther from the inner side surface 68 of the body 53 when viewed from the central axis 60, and engages with the first engaging hole 58 and the second engaging hole 61. It becomes a state. The position of the hub 55 when the engaging portion 57 is engaged with the first engaging hole 58 corresponds to the first position in this embodiment. Further, the position of the hub 55 in the state where the engaging portion 57 is engaged with the second engaging hole 61 corresponds to the second position.

Further, FIG. 3 illustrates a partially enlarged view of the main body portion 55B in the vicinity of the engaging portion 57. As shown in FIG. 3, the free end of the engaging portion 57 has a shape in which the tip surface 74 protrudes in the direction away from the central axis 60. Further, the base end surface 75 of the engaging portion 57 is provided with a recess 76 recessed in the tip direction. In the initial state, the base end surface 75 is in surface contact with the base end surface 70 of the first engagement hole 58 and is engaged. Further, at the time of engagement, the concave portion 76 engages with the convex portion 72 provided on the base end surface 70. Further, the proximal end surface 75 is in surface contact with and engaged with the proximal end surface 73 of the second engaging hole 61 in the locked state. The base end surface 75 is an example of the “base end surface of the engaging portion” of the present invention.

Further, when the engaging portion 57 is pressed from the direction away from the central shaft 60 toward the central shaft 60, for example, the extending portion 56 has the central shaft 60 with the connecting portion 63 with the main body of the hub 55 as a fixed end. Bend in the direction of. As a result, the engaging portion 57 moves in the direction of the central axis 60, and can be disengaged from the first engaging hole 58 and the second engaging hole 61.

Further, the hub 55 is provided with a rib 69 that projects in a direction away from the central axis 60 on the main body portion 55B. FIG. 4 shows an outline of the rib 69. FIG. 4A shows a perspective view of the hub 55 when the rib 69 is placed so as to project upward. Further, FIG. 4B shows a top view of the hub 55 when the rib 69 is placed so as to project upward. Further, FIG. 4C is a cross-sectional view taken along the line XX arrow in FIG. 4B, showing the hub 55 in a state of being housed in the body 53. As shown in FIG. 4, the rib 69 projects in a direction away from the central axis 60. The rib 69 is provided along the central axis 60. Although the rib 69 is provided on the upper surface of the hub, it can also be provided on the lower surface of the hub. On the other hand, a groove 79 for guiding the rib 69 is formed on the inner surface of the main body portion 53B of the body 53. The rib 69 and the groove 79 are in contact with each other. Further, a tip wall 80 is provided at the tip of the groove 79 perpendicular to the moving direction. The tip of the rib 69 is in contact with the tip wall 80. Therefore, when the hub 55 moves in the moving direction, the hub 55 is guided by the groove 79 and the rib 69 formed on the inner surface of the main body 53B of the body 53. As a result, the engaging portion 57 can be reliably guided to the second engaging hole 61. Further, since the tip of the rib 69 is in contact with the tip wall 80, relative movement is prevented so that the hub 55 does not move in the tip direction with respect to the body 53 from the initial state. The tip wall 80 may be provided at a position separated from the tip position of the rib 69 in the initial state by a predetermined distance in the tip direction. In the case of such a structure, the hub 55 is allowed to move in the tip direction with respect to the body 53 from the initial state, but the tip surface 74 of the engaging portion 57 does not hit the body or is hard to hit. preferable. By doing so, it is possible to prevent the engaging portion 57 from hitting the body and being deformed or damaged. Here, the rib 69 is an example of the "guide portion" of the present invention. Further, on the inner surface of the main body 53B, the upper surface and the lower surface in FIG. 4C may be provided with holes penetrating in the direction approaching the central axis 60 instead of the groove 79. Further, a groove may be provided on the outer surface of the hub 55, and a protruding portion may be provided on the inner surface of the body 53.

Further, the indwelling needle 51 includes a coil spring 59 that urges the hub 55 in the moving direction. That is, the engaging portion 57 is urged in the moving direction by the coil spring 59.

<Explanation of accommodation flow>
Next, the flow in which the needle 52 of the indwelling needle 51 is housed in the body 53 will be described. FIG. 5 shows an example of a procedure for releasing the initial state of the indwelling needle 51 shown in FIG. 1 and accommodating the needle 52 in the body 53 to shift to the locked state. FIG. 5A illustrates a front view and a side view of the indwelling needle 51. Further, FIG. 5 (B) shows a cross-sectional view of FIG. 5 (A).

As shown in FIG. 5, first, when the user applies a force to the pressing arm 66 in a direction approaching the central axis 60, the pressing arm 66 bends and the pressing portion 64 and the engaging portion 57 come into contact with each other. Then, the engaging portion 57 is pressed by the pressing portion 64 as it is in the direction approaching the central axis 60. At this time, the concave portion 76 of the engaging portion 57 and the convex portion 72 of the body 53 are engaged with each other. Therefore, the convex portion 72 does not separate from the concave portion 76 unless a predetermined or greater force in the direction approaching the central axis 60 acts on the engaging portion 57. When a force equal to or greater than a predetermined force in the direction approaching the central axis 60 acts on the engaging portion 57, the convex portion 72 is separated from the concave portion 76, and the extending portion 56 approaches the central axis 60 with the connecting portion 63 as a fixed end. Will bend to. After that, the entire engaging portion 57 is disengaged from the first engaging hole 58. Here, when the engaging portion 57 is disengaged from the first engaging hole 58, the tip surface 74 of the engaging portion 57 has an inclined surface that tends toward the tip side as it moves away from the central axis 60. Therefore, contact with the main body 55B of the hub 55 is suppressed. Further, since the hub 55 is urged in the moving direction by the coil spring 59, the hub 55 moves from the front end side to the rear end side when the engaging portion 57 is disengaged from the first engaging hole 58. To do. At that time, since the engaging portion 57 exerts an elastic force that restores the engaging portion 57 in the direction away from the central axis 60, the engaging portion 57 moves in the moving direction while abutting on the inner surface surface of the body 53.

Here, when the engaging portion 57 moves in the moving direction while contacting the inner surface surface of the body 53, the engaging portion 57 first slides on the inclined surface 67 of the body 53. Here, the inclined surface 67 is inclined in a direction away from the central axis 60 as it goes in the moving direction as shown in FIG. 2 (B). Therefore, when the engaging portion 57 slides on the inclined surface 67, the frictional force applied from the inclined surface 67 to the engaging portion 57 is gradually reduced. After that, the engaging portion 57 moves while being in contact with the inner side surface 68 (see FIGS. 2B and 2C) located on the rear end side of the inclined surface 67, and reaches the second engaging hole 61. .. When the engaging portion 57 reaches the second engaging hole 61, the engaging portion 57 fits into the second engaging hole 61 due to the restoring force of the extended portion 56 in the bent state, and becomes the second engaging hole 61. It becomes an engaged lock state.

Further, the indwelling needle 51 is provided with a notch 65 along the moving direction on a surface of the main body 53B that sandwiches the surface on which the first engaging hole 58 and the second engaging hole 61 are provided. When the engaging portion 57 slides on the inner surface 68 including the inclined surface 67 of the body 53, the inner surface 68 including the inclined surface 67 bends so as to bulge in a direction away from the central axis 60 ( (Arrow in FIG. 5B). This also reduces the frictional force applied from the inner side surface 68 to the engaging portion 57 when the engaging portion 57 slides on the inner side surface 68. The notch 65 has a first engaging hole 58 and a second engagement so that the inner side surface 68 is easily bent when the engaging portion 57 is sliding on the inner side surface 68 including the inclined surface 67 of the body 53. It is provided at a position sufficiently close to the hole 61.

FIG. 6 shows an example of an outline of the locked state. FIG. 6A shows a front view and a side view of the indwelling needle 51. Further, FIG. 6B shows a cross-sectional view of FIG. 6A. As shown in FIG. 6, in the locked state, the needle 52 is housed inside the body 53.

Here, even in the locked state, the hub 55 is urged in the moving direction by the coil spring 59. However, the second engaging hole 61 is provided so that the distance X between the second engaging hole 61 and the central shaft 60 is shorter than the distance Y between the first engaging hole 58 and the central shaft 60. .. Therefore, the amount of engagement between the engaging portion 57 and the second engaging hole 61 can be increased, and it is possible to prevent the engaging portion 57 from being disengaged from the second engaging hole 61 in the locked state.

[Action / Effect]
According to the indwelling needle 51 as described above, the engaging portion 57 is disengaged from the first engaging hole 58 by bending the extending portion 56 provided in the hub 55 in the direction approaching the central axis 60. Then, the hub 55 moves in the moving direction due to the urging force in the moving direction by the coil spring 59. At that time, the disengaged engaging portion 57 moves while contacting the inner side surface 68 of the body 53, reaches the second engaging hole 61, and engages with the second engaging hole 61. Here, the distance X between the second engaging hole 61 and the central shaft 60 is shorter than the distance Y between the first engaging hole 58 and the central shaft 60. Therefore, at the first position, the extending portion 56 is in a state of being slightly bent in the direction approaching the central axis 60 due to the natural state or the pressure of the coil spring 59. On the other hand, at the second position, the extending portion 56 is in a state of being more bent in the direction closer to the central axis 60 as compared with the first position. That is, in the first position, the extending portion 56 is not excessively bent, and the load on the engaging portion 57 is suppressed. Therefore, since the user does not have to excessively press the engaging portion 57 in order to disengage the engaging portion 57 from the first engaging hole 58, it is relatively easy to shift the needle 52 to the locked state. Is. On the other hand, a stronger restoring force acts on the engaging portion 57 once engaged with the second engaging hole 61 in a direction away from the central axis 60 than when engaging with the first engaging hole 58. Therefore, it is suppressed that the engaging portion 57 is easily disengaged from the second engaging hole 61. Therefore, when shifting from the initial state to the locked state, the probability that the needle 52 and the hub 55 are housed in the body 53 is improved. At the second position, the engaging portion is preferably housed in the second engaging hole 61. If the engaging portion extends outside the second engaging hole 61, the engaging portion can be pressed from the outside, which is not preferable from the viewpoint of safety.

Further, according to the indwelling needle 51 as described above, the engaging portion 57 or the extending portion 56 is plastically moved toward the central axis 60 by being urged by the coil spring 59 for a long time in the initial state. Even if it is deformed, since the amount of engagement between the engaging portion 57 and the second engaging hole 61 is large, it is possible to prevent the engaging portion 57 from being disengaged from the second engaging hole 61. Will be done. Therefore, the probability that the needle 52 and the hub 55 are housed in the body 53 is improved.

Further, according to the indwelling needle 51 as described above, the concave portion 76 of the engaging portion 57 and the convex portion 72 of the hub 55 are engaged in the initial state. Therefore, for example, even if the user does not intend to accommodate the needle 52 in the body 53 and mistakenly presses the engaging portion 57 in the direction approaching the central axis 60,
It is suppressed that the engaging portion 57 is disengaged from the first engaging hole 58. Further, the engagement between the concave portion 76 and the convex portion 72 prevents the engaging portion 57 from being deformed in the direction approaching the central axis 60 due to the spring pressure of the coil spring 59.

Further, according to the indwelling needle 51 as described above, when the engaging portion 57 is engaged with the first engaging hole 58 in the initial state, the base end surface 70 of the first engaging hole 58 is the body 53. It is in surface contact with the base end surface 75. Therefore, the urging force of the coil spring 59 can be received by the base end surface 75, and damage such as breakage of the engaging portion 57 due to the constant pressure of the coil spring 59 is reduced.

Further, according to the indwelling needle 51 as described above, the notch 65 is provided along the moving direction on the surface sandwiching the surface on which the first engaging hole 58 and the second engaging hole 61 are provided. Therefore, when the hub 55 slides on the inner side surface 68 of the body 53, the inclined surface 67 or the inner side surface 68 tends to bend in the direction away from the central axis 60. Therefore, the frictional resistance that the engaging portion 57 of the hub 55 receives from the inclined surface 67 or the inner surface 68 of the body 53 is reduced.

Further, the frictional resistance received by the engaging portion 57 of the hub 55 from the inclined surface 67 or the inner surface 68 of the body 53 can be reduced, so that the urging force of the coil spring 59 can be reduced, and the engaging portion 57 or the engaging portion 57 can be extended. It is possible to prevent the protruding portion 56 from being plastically deformed so as to approach the central axis 60. From this as well, it is suppressed that the engaging portion 57 once engaged with the second engaging hole 61 is disengaged from the second engaging hole 61, and the probability that the needle 52 and the hub 55 are accommodated in the body 53. Will improve.

Further, the distance between the central shaft 60 and the inner side surface 68 is longer than the distance between the first engaging hole 58 and the central shaft 60 and the distance between the second engaging hole 61 and the central shaft 60. Therefore, the engaging portion 57 bends in the direction of approaching the central axis 60 once when it disengages from the first engaging hole 58, but the amount of bending decreases when it is in contact with the inner side surface 68. That is, the degree to which the urging force urging away from the central axis 60 acts on the engaging portion 57 is reduced. From this as well, when the engaging portion 57 moves in the moving direction, the frictional resistance acting on the engaging portion 57 from the inner side surface 68 is reduced.

Further, since the engaging portion 57 is a free end, when the hub 55 moves in the moving direction inside the body 53, the engaging portion 57 moves smoothly along the inner side surface 68. Therefore, the movement of the engaging portion 57 is suppressed from rattling, and the moving distance required for moving the needle 52 and the hub 55 can be reduced. Further, the tip surface 74 of the engaging portion 57 has a shape protruding in a direction away from the central axis. Therefore, as shown in FIG. 6, the engaging portion 57 and the tip wall 78 of the second engaging hole 61 are opposed to each other in the locked state. Therefore, even when a force that moves in the tip direction acts on the hub 55 in the locked state, the hub 55 is prevented from moving in the tip direction when the hub 55 comes into contact with the tip wall 78.

Further, according to the indwelling needle 51 as described above, the base end surface 73 forming the second engaging hole 61 extends in the direction approaching the central axis 60 and toward the tip end direction of the body 53. Therefore, the engaging portion 57 is prevented from being disengaged from the second engaging hole 61 in the locked state. Therefore, the needle 52 and the hub 55 are prevented from moving in the proximal direction and falling out of the opening of the body 53 provided in the proximal direction.

Further, in the above embodiment, the tip portion 53A of the body 53 has a cylindrical shape, and the main body portion 53B is a tubular member having a rectangular cross section with rounded corners long in the vertical direction. The shape is not limited to this. The body 53 may have a shape in which the tip portion 53A and the main body portion 53B have a hollow portion capable of accommodating the needle 52 and the hub 55, and may be, for example, a rectangular shape or an oval with chamfered corners. Further, the number of notches 65 is not limited. Further, the position of the notch 65 is provided so that when the hub 55 slides on the inner side surface 68 of the body 3, the inclined surface 67 or the inner side surface 68 of the body 53 bends in a direction away from the central axis 60. Good.

<Modification example>
FIG. 7 shows an outline of the indwelling needle 51A according to the modified example. FIG. 7A is a front view and a side view of the indwelling needle 51A. Further, FIG. 7B is a cross-sectional view taken along the line AA in FIG. 7A. The hub 55 of the indwelling needle 51A is not provided with the rib 69 as shown in FIG. In such an indwelling needle 51A, when the engaging portion 57 is unintentionally pushed and moved in the direction approaching the central axis 60, the engaging portion 57 vigorously hits the tip wall of the first engaging hole 58 and engages. It is possible that the joint 57 may be damaged. In this case, when the hub 55 is returned to the initial position by the coil spring 59, the convex portion 72 may not be engaged with the concave portion 76, and the stability of the engaging portion 57 at the initial position may be impaired. Therefore, in the indwelling needle 51A, the outer surface of the tip wall 81 of the first engaging hole 58 is partially cut out. According to such an indwelling needle 51A, it is suppressed that the engaging portion 57 comes into contact with the tip wall 81 of the first engaging hole 58 when the engaging portion 57 is pressed in the direction approaching the central axis 60. Therefore, even when the engaging portion 57 is moved from the initial position toward the tip end and returned to the initial position, the concave portion 76 and the convex portion 72 of the engaging portion 57 are stably engaged with each other. From the viewpoint of moldability, the notch on the outer surface of the tip wall 81 of the first engaging hole 58 may be tapered so that the outer surface tapers toward the central axis toward the base end.

The embodiments and modifications disclosed above can be combined with each other.

1 ・ ・ Indwelling needle; 2 ・ ・ Needle; 3 ・ ・ Body; 3B ・ ・ Main body part; 4 ・ ・ Opening; 5 ・ ・ Hub; 5A ・ ・ Tip part; 5B ・ ・ Main body part; 6 ・ ・ Extension part 7 ... Engagement part; 8 ... First engagement hole; 9 ... Coil spring; 10 ... Central axis; 11 ... Second engagement hole; 14 ... Pressing part; 15 ... Pressing arm; 16・ ・ Inner surface; 51 ・ ・ Indwelling needle; 52 ・ ・ Needle; 53 ・ ・ Body; 53A ・ ・ Tip part; 53B ・ ・ Main body part; 54 ・ ・ Opening; 55 ・ ・ Hub; 55A ・ ・ Tip part; 55B・ ・ Main body part; 55C ・ ・ Rear end part; 56 ・ ・ Extension part; 57 ・ ・ Engagement part; 58 ・ ・ First engagement hole; 59 ・ ・ Coil spring; 60 ・ ・ Central axis; 61 ・ ・ No. Two engagement holes; 62 ... Joint part; 63 ... Joint part; 64 ... Pressing part; 65 ... Notch; 66 ... Pressing arm; 67 ... Inclined surface; 68 ... Inner surface; 69 ... Ribs; 70 ... Base end surface; 72 ... Convex part; 73 ... Base end surface; 74 ... Tip surface; 75 ... Base end surface; 76 ... Recessed; 78 ... Tip wall; 79 ... Groove; Tip wall 80; tip wall 81

Claims (11)

Hollow needle and
An accommodating portion which is a substantially tubular member having a hollow portion capable of accommodating the hollow needle, and an accommodating portion.
The hollow needle is arranged inside the accommodating portion while supporting the base end of the hollow needle, and the hollow needle is placed in the accommodating portion from a first position where the hollow needle protrudes from the opening of the hollow portion at one end of the accommodating portion. A moving member capable of moving the hollow portion to a second position accommodated in the hollow portion of the
A spring that urges the moving member in the direction from the first position to the second position,
The moving member is provided with an engaging mechanism for engaging the moving member with the accommodating portion at the first position and the second position.
The engaging mechanism is
An engaging portion provided on the moving member and extending in a direction away from the central axis,
A first engaged portion provided on the side surface of the accommodating portion and engaging with the engaging portion at the first position,
It has a second engaged portion that engages with the engaging portion at the second position, and has.
The distance from the central axis to the second engaged portion is shorter than the distance from the central axis to the first engaged portion.
Indwelling needle. The surface of the second engaged portion facing the base end surface of the engaging portion has a surface extending in a direction approaching the central axis toward the tip of the hollow needle, and the base end surface of the engaging portion is the second. Engage with the second engaged portion at the position of
The indwelling needle according to claim 1. The first engaged portion or the facing surface of the second engaged portion facing the base end surface of the engaging portion has a convex portion extending toward the tip end.
The engaging portion has a concave portion corresponding to the convex portion on the base end surface of the engaging portion.
The indwelling needle according to claim 2. The facing surface of the first engaged portion facing the base end surface of the engaging portion extends in the direction approaching the central axis and the tip end direction, and the base end surface of the engaging portion of the engaging portion is with the facing surface. Engage,
The indwelling needle according to any one of claims 1 to 3. The distance between the inner wall of the accommodating portion and the central axis between the first engaged portion and the second engaged portion is at least a part of the distance between the first engaged portion and the central axis. Longer than the distance, longer than the distance between the second engaged portion and the central axis,
The indwelling needle according to any one of claims 1 to 4. The free end of the engaging portion has a shape in which the tip side protrudes in a direction away from the central axis.
The indwelling needle according to any one of claims 1 to 5. The tip wall of the engaging portion has a shape protruding toward the tip side toward the direction away from the central axis.
The indwelling needle according to any one of claims 1 to 6. Hollow needle and
An accommodating portion which is a substantially tubular member having a hollow portion capable of accommodating the hollow needle, and an accommodating portion.
The hollow needle is arranged inside the accommodating portion while supporting the base end of the hollow needle, and the hollow needle is placed in the accommodating portion from a first position where the hollow needle protrudes from the opening of the hollow portion at one end of the accommodating portion. A moving member capable of moving the hollow portion to a second position accommodated in the hollow portion of the
A spring that urges the moving member in the direction from the first position to the second position,
The moving member is provided with an engaging mechanism for engaging the moving member with the accommodating portion at the first position and the second position.
The engaging mechanism is
An engaging portion provided on the moving member and extending in a direction away from the central axis,
A first engaged portion provided on the side surface of the accommodating portion and engaging with the engaging portion at the first position,
It has a second engaged portion that engages with the engaging portion at the second position, and has.
Cut along the direction from the first position to the second position on the side surface of the accommodating portion having an angle with the side surface provided with the first engaged portion and the second engaged portion. Notches are provided,
Indwelling needle. In the accommodating portion, at least a part of the inner wall of the side surface with which the engaging portion abuts has an inclined surface that inclines in a direction away from the central axis from the first position toward the second position.
The indwelling needle according to claim 8. The moving member further has a guide portion that protrudes in a direction away from the central axis or is recessed in a direction approaching the central axis.
The accommodating portion further has a guided portion that engages with the guide portion.
The indwelling needle according to claim 8 or 9. The moving member further has ribs that prevent the moving member from moving relative to the accommodating portion in the distal position at the first position.
The indwelling needle according to claim 10.

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