Medicinal liquid administration device

Abstract

A medicinal liquid administration device (10A) comprises a lock part (18) that couples a housing (12) to a cap (16) provided at a tip of the housing (12). The lock part (18) has a coupling member (42), a first coupling structure (44) that couples the housing (12) to the coupling member (42), and a second coupling structure (46) that couples the cap (16) to the coupling member (42). By canceling the coupled state of the first coupling structure (44) and / or the second coupling structure (46), an unlocked state is achieved in which the cap (16) can be removed from the housing (12).

Description

Medical solution administration device

[0001] The present invention relates to a drug solution administration device.

[0002] Japanese Patent No. 6154061 discloses a device that includes a cylindrical casing, a syringe that is housed inside the casing and filled with a medicinal solution, and a cap that is removably attached to the tip of the casing. When used by a user, the cap is removed from the tip of the casing, and then a puncture needle at the tip of the syringe protrudes from the tip of the casing, puncturing the skin with the puncture needle to administer the medicinal solution subcutaneously.

[0003] Patent No. 6154061

[0004] In the above-described medicinal solution administration device, the puncture needle protrudes from the tip of the housing and is exposed to the outside after the cap is removed. Therefore, it is desirable to reduce the risk of accidental puncture when the cap is removed by mistake.

[0005] The present invention aims to solve the above-mentioned problems.

[0006] (1) An aspect of the present invention is a drug solution administration device for administering the drug solution into a living body, comprising: a housing formed in a hollow cylindrical shape; a syringe having a cylindrical body housed within the housing and filled with a drug solution, and a puncture needle connected to the cylindrical body to administer the drug solution into a living body; and a cap provided at the tip of the housing and removed when the puncture needle punctures a target to be punctured. The drug solution administration device comprises a locking section that connects the cap to the housing, and the locking section has a connecting member, a first connecting structure that connects the housing to the connecting member, and a second connecting structure that connects the cap to the connecting member. By releasing the connected state of at least one of the first connecting structure and the second connecting structure, the drug solution administration device enters an unlocked state in which the cap can be removed from the housing.

[0007] According to this drug solution administration device, by providing a locking portion that connects the housing and the cap, removal of the cap from the tip of the housing is prevented unless the first connecting structure or the second connecting structure is released, thereby reducing the occurrence of accidental punctures caused by accidentally removing the cap from the tip of the housing.

[0008] (2) In the drug solution administration device described in (1) above, the locking portion may be set to the unlocked state by operating at least a portion of the connecting member in a direction different from the axial direction of the housing.

[0009] With this configuration, the operating direction of the connecting member is different from the axial direction of the housing, making it less likely that the connecting member will be operated by mistake by the user.

[0010] (3) In the drug solution administration device described in (1) or (2) above, the unlocked state is achieved by releasing the connection between the housing and the connecting member by the first connecting structure, and when the cap is removed from the housing, the connecting member may be removed from the housing together with the cap while the cap and the connecting member are connected by the second connecting structure.

[0011] With this configuration, when the connection state of the first connection structure is released to an unlocked state, the connection member can be removed together with the cap, so that the second connection structure does not remain in the housing, and the connection member can be discarded together with the cap.

[0012] (4) In the drug solution administration device described in (1) above, the connecting member is a rotating member formed in a cylindrical shape and rotatable around the axis of the housing, and the unlocked state may be achieved by rotating the rotating member.

[0013] This configuration allows the connecting member to be configured with a simple structure, thereby reducing costs.

[0014] (5) In the drug solution administration device described in (2) above, the connecting member is formed in a hollow cylindrical shape having a distal opening and a proximal opening, the cap is inserted into the distal opening, the housing is inserted into the proximal opening, and an internal space is provided in which the cap and the housing are accommodated, the connecting member has a first rib protruding from an inner wall of the distal end portion having the distal opening, and an engagement groove extending in a circumferential direction and provided on an inner wall of the proximal end portion having the proximal opening, the cap has a second rib provided on the proximal end portion and protruding from an outer wall of the cap, and the distal end portion of the housing is fitted to the outer wall of the housing. the first connecting structure is an engaging structure in which the engaging protrusion and the engaging groove engage with each other, and the second connecting structure is an abutment structure in which the base end of the first rib and the tip end of the second rib face each other in the axial direction of the housing and the base end and the tip end can abut each other, and by rotating the connecting member relative to the housing around the axis of the housing, the engaging protrusion of the housing disengages from the engaging groove of the connecting member, and the connected state of the first connecting structure is released, resulting in a first disconnected state.

[0015] With this configuration, the first connecting structure can effectively connect the housing and the connecting member by engaging the engaging protrusion with the engaging groove. The connection by the first connecting structure can be easily released by rotating the connecting member relative to the housing. When removing the cap from the housing, the first rib and the second rib abut axially, preventing the cap from moving toward the tip relative to the connecting member, and allowing the connecting member to be removed together with the cap.

[0016] (6) In the drug solution administration device described in (5) above, the engagement groove of the connecting member is spirally shaped around the axis of the connecting member, and when the first connecting structure is released from the connected state, the engagement protrusion moves along the engagement groove, causing the connecting member to move in the tip direction relative to the housing, and the base end of the first rib and the tip end of the second rib in the second connecting structure are separated, and when the cap is removed in the tip direction relative to the housing, the base end of the first rib and the tip end of the second rib may abut.

[0017] With this configuration, the connection state of the first connection structure can be easily released by rotating the connection member relative to the housing. When removing the cap from the housing, the second connection structure allows the connection member to be easily removed together with the cap.

[0018] (7) In the drug solution administration device described in (5) above, the housing has a first indicator, and the connecting member has a second indicator, and by rotating the connecting member relative to the housing around the axis of the housing, the first indicator and the second indicator are arranged in a straight line in the axial direction of the housing and the connecting member, and the engaging protrusion of the housing disengages from the engaging groove of the connecting member, thereby entering the first disconnected state in which the connection by the first connecting structure is released.

[0019] With this configuration, when rotating the connecting member relative to the housing, the user can easily visually confirm through the first and second indicators that the rotation of the connecting member has been completed and the connection of the first connecting structure has been released.

[0020] (8) In the drug solution administration device described in (7) above, the first indicator may be a window portion through which the syringe can be viewed from outside the housing, and the second indicator may be a hole portion that penetrates the outer wall of the connecting member.

[0021] With this configuration, by utilizing the window provided for checking the syringe, the manufacturing cost of the drug solution administration device can be reduced compared to a structure in which a first indicator is newly provided. By using the hole as the second indicator, the second indicator can be easily provided on the connecting member.

[0022] (9) In the drug solution administration device described in (5) above, the connecting member may have a groove forming portion having the engagement groove, and at least the groove forming portion may be transparent, so that the engagement groove can be seen from outside the connecting member through the groove forming portion.

[0023] With this configuration, the transparent groove forming portion allows the user to check the engagement state between the engagement protrusion and the engagement groove from the outside of the connecting member, thereby enabling the user to effectively confirm that the rotation of the connecting member has been completed.

[0024] (10) In the drug solution administration device described in (6) above, in the first disconnected state in which the engaging protrusion of the housing disengages from the engaging groove of the connecting member and the first connecting structure is released, the cap may have an abutment portion that abuts against the tip end of the connecting member.

[0025] With this configuration, when the connection by the first connection structure is released, the user recognizes that the connection member has moved toward the tip and the tip portion has come into contact with the abutment portion, thereby effectively confirming that the connection member has completed rotation and the connection by the first connection structure has been released, entering the first released state.

[0026] (11) In the drug solution administration device described in (1) above, the connecting member is a rotating member that is arranged across the base end of the cap and the tip end of the housing and is rotatable around a vertical axis that is perpendicular to the axial direction of the housing, and the unlocked state may be achieved by rotating the rotating member.

[0027] This configuration allows the connecting member to be configured with a simple structure, thereby reducing costs.

[0028] (12) In the drug solution administration device described in (2) above, when the housing and the cap are connected by the first connecting structure and the second connecting structure, the connecting member is arranged to straddle the base end of the cap and the tip end of the housing, the connecting member is arranged on the outer wall of the cap so as to be rotatable around a vertical axis perpendicular to the axial direction of the housing, the tip end of the housing has a first engaging protrusion protruding from the outer wall of the housing, the connecting member has a first engaging groove with which the first engaging protrusion engages, and the first engaging groove extends along a rotation direction around the vertical axis, the first connecting structure is an engaging structure between the first engaging protrusion and the first engaging groove, and the second connecting structure is a fixing structure between the connecting member and the cap, and by rotating the connecting member around the vertical axis, the first engaging protrusion disengages from the first engaging groove, resulting in a first disconnected state in which the first connecting structure is released.

[0029] With this configuration, when the connection state of the first connection structure is released and the cap is removed, the connecting member connected by the second connection structure can be removed together with the cap. This prevents the connecting member from remaining in the housing and allows the connecting member to be discarded together with the cap. The connection between the housing and the connecting member by the first connection structure can be easily released by rotating the connecting member about the vertical axis.

[0030] (13) In the drug solution administration device described in (12) above, the cap has a second engagement protrusion protruding from the outer wall of the cap, the connecting member has a second engagement groove into which the second engagement protrusion engages, the second engagement groove extends along the rotation direction centered on the vertical axis, and the second engagement protrusion may move along the second engagement groove by rotating the connecting member around the vertical axis.

[0031] With this configuration, when the connecting member is rotated around the vertical axis, the second engagement protrusion moves along the second engagement groove, thereby effectively stabilizing the rotation of the connecting member.

[0032] (14) In the drug solution administration device described in (13) above, by rotating the connecting member around the vertical axis, the second engagement protrusion may be disengaged from the second engagement groove, resulting in a second disconnected state in which the connection between the connecting member and the cap by the second connecting structure is released.

[0033] With this configuration, when the cap is removed from the housing, the connecting member can be removed from both the housing and the cap.

[0034] (15) In the drug solution administration device described in (1) above, the connecting member is a sliding member that is arranged across the base end of the cap and the tip end of the housing and is slidable in a transverse direction that intersects with the axial direction of the housing, and the unlocked state may be achieved by moving the sliding member in the transverse direction.

[0035] This configuration allows the connecting member to be configured with a simple structure, thereby reducing costs.

[0036] (16) In the drug solution administration device described in (2) above, when the housing and the cap are connected by the first connecting structure and the second connecting structure, the connecting member is provided across the base end of the cap and the tip end of the housing, the connecting member is provided on the outer wall of the cap so as to be slidable in a transverse direction that intersects the axial direction of the housing and along the outer wall of the housing, the tip end of the housing has a first engaging protrusion protruding from the outer wall of the housing, the connecting member has a first engaging groove with which the first engaging protrusion engages, the first engaging groove extends along the transverse direction, the first connecting structure is an engaging structure between the first engaging protrusion and the first engaging groove, and the second connecting structure is a fixing structure between the connecting member and the cap, and by moving the connecting member in the transverse direction, the first engaging protrusion disengages from the first engaging groove, resulting in a first disconnected state in which the first connecting structure is released.

[0037] With this configuration, when the connection state of the first connection structure is released and the cap is removed, the connecting member connected to the cap by the second connection structure can be removed together. This prevents the connecting member from remaining in the housing and allows the connecting member to be discarded together with the cap. By sliding the connecting member in the cross direction, the connection between the housing and the connecting member by the first connection structure can be easily released.

[0038] (17) In the drug solution administration device described in (16) above, the cap has a second engagement protrusion protruding from the outer wall of the cap, the connecting member has a second engagement groove into which the second engagement protrusion engages, the second engagement groove extends along the intersecting direction, and the second engagement protrusion may move along the second engagement groove by moving the connecting member in the intersecting direction.

[0039] With this configuration, when the connecting member is slid in the transverse direction, the second engaging projection moves along the second engaging groove, thereby effectively stabilizing the movement of the connecting member.

[0040] (18) In the drug solution administration device described in (17) above, by moving the connecting member in the intersecting direction, the second engaging protrusion may be disengaged from the second engaging groove, resulting in a second disconnected state in which the connection between the connecting member and the cap by the second connecting structure is released.

[0041] With this configuration, when the cap is removed from the housing, the connecting member can be removed from both the housing and the cap.

[0042] (19) In the drug solution administration device described in (1) above, the connecting member is a plate-like member that is provided across the base end of the cap and the tip end of the housing and is removable from at least one of the cap and the housing, and the unlocked state may be achieved by removing the plate-like member from either the cap or the housing.

[0043] This configuration allows the connecting member to be configured with a simple structure, thereby reducing costs.

[0044] (20) In the drug solution administration device described in (2) above, the distal end of the housing has a first engaging protrusion protruding from an outer wall of the housing, and the proximal end of the cap has a second engaging protrusion protruding from an outer wall of the cap, and in a state in which the housing and the cap are connected by the first connecting structure and the second connecting structure, the connecting member is provided across the proximal end of the cap and the distal end of the housing, and the connecting member is a plate-like member having a first engaging hole with which the first engaging protrusion is engaged and a second engaging hole with which the second engaging protrusion is engaged, The connecting structure is an engaging structure in which the first engaging protrusion and the first engaging hole engage, and the second connecting structure is an engaging structure in which the second engaging protrusion and the second engaging hole engage, and by detaching the connecting member from the housing, the first engaging protrusion disengages from the first engaging hole, thereby achieving a first disconnected state in which the connected state by the first connecting structure is released, or by detaching the connecting member from the cap, the second engaging protrusion disengages from the second engaging hole, thereby achieving a second disconnected state in which the connected state by the second connecting structure is released.

[0045] With this configuration, the connection between the connecting member and the housing by the first connecting structure can be released by removing the connecting member from the housing, and the connection between the connecting member and the cap by the second connecting structure can be released by removing the connecting member from the cap, so the user can choose how to handle the connecting member after the connection state by the locking section is released.

[0046] (21) In the drug solution administration device described in (20) above, in the unlocked state, the connection state of one of the first connecting structure and the second connecting structure may be released, and the connection state of the other of the first connecting structure and the second connecting structure may be maintained.

[0047] With this configuration, by maintaining the other connected state of the first and second connecting structures, it is possible to choose whether to remove and discard the connecting member together with the cap, or to leave the connecting member attached to the housing.

[0048] (22) In the drug solution administration device described in (20) above, in the unlocked state, the connection states by the first connection structure and the second connection structure may both be released, resulting in the first disconnected state and the second disconnected state.

[0049] With this configuration, when the cap is removed from the housing, no connecting member remains on either the cap or the housing.

[0050] (23) In the drug solution administration device described in (20) above, the connecting member may have a first slit extending between the first engagement hole and the second engagement hole, and the first slit may connect the first engagement hole and the second engagement hole.

[0051] With this configuration, when the first engaging projection is to be disengaged from the first engaging hole, the first slit facilitates disengagement of the first engaging projection, facilitating removal of the connecting member.When the second engaging projection is to be disengaged from the second engaging hole, the first slit facilitates disengagement of the second engaging projection, facilitating removal of the connecting member.

[0052] (24) In the drug solution administration device described in (23) above, the connecting member may have a second slit provided in the opposite direction to the first slit relative to the first engagement hole, and a third slit provided in the opposite direction to the first slit relative to the second engagement hole, and the second slit may be formed in connection with the first engagement hole, and the third slit may be formed in connection with the second engagement hole.

[0053] With this configuration, by providing the second and third slits in addition to the first slit, the first and second engaging protrusions can be more effectively released from the first and second engaging holes, making it even easier to remove the connecting member.

[0054] According to the present invention, a locking portion is provided that connects the cap to the housing, and the locking portion has a first connecting structure that connects the housing to the connecting member and a second connecting structure that connects the cap to the connecting member. Therefore, by releasing the connection state of at least one of the first connecting structure and the second connecting structure, an unlocked state is established in which the cap can be removed from the housing. Therefore, unless the first connecting structure or the second connecting structure is released, removal of the cap from the tip of the housing is prevented. This reduces the occurrence of accidental punctures caused by accidentally removing the cap from the tip of the housing.

[0055] FIG. 1 is an external perspective view of a chemical solution administration device according to a first embodiment of the present invention. FIG. 2 is a partially exploded perspective view of the chemical solution administration device of FIG. 1. FIG. 3 is a cross-sectional view of the chemical solution administration device of FIG. 1. FIG. 4 is a first explanatory view showing a tip portion of the chemical solution administration device. FIG. 5 is a second explanatory view showing the tip portion of the chemical solution administration device. FIG. 6A is an explanatory view showing a locked state of a locking unit. FIG. 6B is an explanatory view showing an unlocked state of the locking unit. FIG. 6C is a plan view of the unlocked state shown in FIG. 6B. FIG. 7 is an explanatory view showing a state in which a cap has been removed from a housing in the unlocked state of the locking unit. FIG. 8 is a cross-sectional view showing a state in which the cap has been removed from the chemical solution administration device of FIG. 3. FIG. 9 is a cross-sectional view showing a puncturing state of the chemical solution administration device of FIG. 8. FIG. 10A is an explanatory view showing a locked state of a locking unit according to a modified example of the first embodiment. FIG. 10B is an explanatory view showing an unlocked state of the locking unit. FIG. 11A is a perspective view showing a tip portion of a chemical solution administration device according to a second embodiment of the present invention. FIG. 11B is an exploded perspective view of a locking unit in the chemical solution administration device of FIG. 11A. FIG. 12 is a plan view showing the tip portion of the chemical solution administration device of FIG. 11A. FIG. 13A is an explanatory diagram showing an unlocked state of the locking unit of the chemical solution administration device shown in FIG. 12. FIG. 13B is an explanatory diagram showing a state in which a cap has been removed from the tip portion of the housing. FIG. 14A is a perspective view showing the tip portion of a chemical solution administration device according to a third embodiment of the present invention. FIG. 14B is an exploded perspective view of the locking unit in the chemical solution administration device of FIG. 14A. FIG. 15 is a plan view showing the tip portion of the chemical solution administration device of FIG. 14A. FIG. 16A is an explanatory diagram showing an unlocked state of the locking unit of the chemical solution administration device shown in FIG. 15. FIG. 16B is an explanatory diagram showing a state in which a cap has been removed from the tip portion of the housing. FIG. 17 is a plan view showing the tip portion of a chemical solution administration device according to a modified example of the third embodiment. FIG. 18A is an explanatory diagram showing an unlocked state of the locking unit of the chemical solution administration device shown in FIG. 17. Fig. 18B is an explanatory diagram showing a state in which a cap has been removed from the tip of the housing. Fig. 19 is a perspective view showing the tip of a chemical solution administration device according to a fourth embodiment of the present invention. Fig. 20 is a plan view showing the tip of the chemical solution administration device of Fig. 19. Fig. 21 is an explanatory diagram showing an unlocked state of a locking section of the chemical solution administration device shown in Fig. 20.Fig. 22A is an explanatory diagram showing a state in which the cap is removed from the tip of the housing, and Fig. 22B is an explanatory diagram showing an unlocked state in which the connecting member is removed from the housing and the cap.

[0056] 1, medicinal solution administration device 10A according to the first embodiment is used, for example, to administer medicinal solution M (see FIG. 3) subcutaneously to a patient who is a user. Medicinal solution administration device 10A includes a hollow cylindrical housing 12, a syringe 14 (see FIG. 3) housed inside housing 12, a cap 16 provided at the tip of housing 12, and a locking unit 18 that connects cap 16 to housing 12.

[0057] The housing 12 has a predetermined length in the axial direction (direction of arrows A and B). The distal end and proximal end of the housing 12 are each open (see FIG. 3 ). The peripheral wall of the housing 12 includes a housing outer wall 121. The housing outer wall 121 is provided with a first indicator 201. The first indicator 201 has a plurality of windows 22 that allow the syringe 14 to be viewed from outside the housing 12. The plurality of windows 22 allow the syringe 14 to be viewed from outside the housing 12. In this embodiment, a case where a pair of windows 22 is provided will be described. Note that the number of windows 22 is not limited to a pair. One window 22 may be provided, or three or more windows 22 may be provided. The window 22 is formed to penetrate the housing outer wall 121 of the housing 12 (see FIG. 5 ). The medicinal solution M in the syringe 14 can be viewed through the window 22. The window 22 is formed elongated and linearly along the axial direction of the housing 12.

[0058] As shown in Fig. 2, the tip of the housing 12 is provided with an engagement protrusion 24 that protrudes outward from the housing outer wall 121. A pair of engagement protrusions 24 is provided (see Fig. 5), and each engagement protrusion 24 is disposed between the tip of each window portion 22 and the tip of the housing 12. Each engagement protrusion 24 is disposed between the tip of each window portion 22 and the tip of the housing 12, close to the tip of the window portion 22. Note that the number of engagement protrusions 24 is not limited to a pair. The housing 12 may be configured to have a single engagement protrusion 24.

[0059] As shown in Fig. 3, a pair of recesses 166 are formed inside the tip of the housing 12. The recesses 166 are recessed radially into the inner peripheral surface of the housing 12. The pair of recesses 166 are arranged at positions symmetrical with respect to the axis on the inner peripheral surface of the housing 12. When the cap 16 is attached to the tip of the housing 12, the recesses 166 are arranged at positions facing the holding arms 163 of the cap 16.

[0060] The housing 12 contains a needle cover 28 and a sleeve body 30 that are movably housed within the housing 12, and the proximal end of the housing 12 is closed by an end cap 32. The needle cover 28 is provided so as to be able to protrude from the distal end of the housing 12 in the distal direction (in the direction of arrow B). The sleeve body 30 is hollow and is housed on the proximal end side of the housing 12. The end cap 32 has a lid portion 321 that closes the proximal end of the housing 12 and a rod portion 322 that extends from the center of the lid portion 321 toward the distal side (in the direction of arrow B). A plunger 34 is provided on the outer periphery of the rod portion 322, and an injection spring 36 is provided between the plunger 34 and the lid portion 321. The resilient force of the injection spring 36 urges the plunger 34 in the distal direction.

[0061] The syringe 14 includes a hollow cylindrical body 141, a stopper 142 slidably inserted into the cylindrical body 141, and a puncture needle 143 provided at the tip of the cylindrical body 141 and protruding toward the tip (in the direction of arrow B). A cylindrical syringe holder 38 is disposed on the outer periphery of the cylindrical body 141. The syringe holder 38 holds the cylindrical body 141 inside the housing 12. The medicinal liquid M used may be, for example, a liquid used for subcutaneous injection into a user (living body).

[0062] The cylindrical body 141 is hollow and has a chamber 144 filled with the medicinal liquid M. The tip of the cylindrical body 141 is provided with a needle holding portion 145 that holds the puncture needle 143. The cylindrical body 141 is made of a transparent resin material. The stopper 142 is made of an elastic material such as rubber. The stopper 142 is attached to the tip of the plunger 34 via a top member (not shown). The stopper 142 is housed in the chamber 144 of the cylindrical body 141. The stopper 142 seals the medicinal liquid M in the chamber 144 inside the cylindrical body 141.

[0063] The puncture needle 143 is a hollow body having a flow path therein through which the medicinal liquid M flows. The puncture needle 143 protrudes from the needle holding portion 145 toward the tip (in the direction of arrow B). The flow path of the puncture needle 143 communicates with a chamber 144 of the cylindrical body 141 that is filled with the medicinal liquid M. The medicinal liquid M filled in the chamber 144 of the cylindrical body 141 is discharged from the tip of the puncture needle 143 and administered to the user.

[0064] The cap 16 is removed from the distal end of the housing 12 when the puncture needle 143 is inserted into a living body (see FIG. 7). As shown in FIG. 4, the cap 16 is cylindrical with a bottom, and has a bottom wall 161 formed at the distal end and a cap outer wall 162 extending from the bottom wall 161 toward the proximal end (in the direction of arrow A). The cap outer wall 162 is annular. The proximal end of the cap 16 is open (see FIG. 3). The cap 16 includes a pair of holding arms 163 (see FIG. 3) and a cap-side rib 40 (hereinafter referred to as the second rib 40).

[0065] As shown in Fig. 3, the retaining arm 163 protrudes in the axial direction (direction of arrow A) from the base end of the cap outer wall 162. The retaining arm 163 is disposed radially inward relative to the cap outer wall 162 and is capable of tilting radially around the connection point with the cap outer wall 162 as a fulcrum. The base end of the retaining arm 163 is provided with a hook 164 that protrudes radially inward. The retaining arms 163 are disposed in pairs at positions symmetrical about the central axis of the cap 16. The base end of the cap 16 has an end insertion groove 165 into which the tip of the housing 12 can be inserted.

[0066] When the cap 16 is attached to the tip of the housing 12, the base end of the cap outer wall 162 abuts against the tip of the housing 12, and the hooks 164 of the pair of holding arms 163 engage with the recesses 166. The tip of the housing 12 is inserted into the end insertion groove 165 of the cap 16.

[0067] As shown in Figure 4, the second rib 40 is provided at the base end of the cap 16 and protrudes radially outward from the cap outer wall 162. The second rib 40 is annular along the circumferential direction of the cap outer wall 162 (see Figure 2). The second rib 40 is provided radially outward from the retaining arm 163. The outer surface of the second rib 40 is tapered toward the base end. The tip end of the second rib 40 has a surface that intersects with the axial direction of the cap 16 (the direction of arrows A and B).

[0068] The locking unit 18 includes a connecting member 42, a first connecting structure 44, and a second connecting structure 46. The locking unit 18 enters an unlocked state in which the cap 16 can be removed from the housing 12 by releasing the connected state of at least one of the first connecting structure 44 and the second connecting structure 46.

[0069] The connecting member 42 unlocks the locking unit 18 when operated in a direction different from the axial direction of the housing 12. As shown in Fig. 2, the connecting member 42 is a rotating member 42a formed in a hollow cylindrical shape and provided to be rotatable about the axis of the housing 12. The locking unit 18 is unlocked when the rotating member 42a is rotated relative to the housing 12. In other words, the rotation direction of the connecting member 42 is a direction different from the axial direction of the housing 12 (the direction of arrows A and B).

[0070] The connecting member 42 includes a main body tubular portion 481, a proximal end tubular portion 482 provided at the proximal end of the main body tubular portion 481, a locking rib 50 (hereinafter referred to as the first rib 50), and an engagement groove 58. As shown in FIG. 4 , the distal end of the main body tubular portion 481 is provided at the distal end of the connecting member 42. The distal end of the main body tubular portion 481 includes a distal end opening 521 that opens in the axial direction. The proximal end of the cap 16 is inserted into the distal end opening 521. The proximal end of the proximal end tubular portion 482 is provided at the proximal end of the connecting member 42. The proximal end of the proximal end tubular portion 482 includes a proximal end opening 522 that opens in the axial direction. The distal end of the housing 12 is inserted into the proximal end opening 522. The connecting member 42 has an internal space 523 that accommodates the cap 16 and a portion of the housing 12. The internal space 523 communicates with the distal end opening 521 and the proximal end opening 522.

[0071] As shown in FIG. 2 , the outer wall of the main body tubular portion 481 includes a second indicator 202 and a grip portion 56. The second indicator 202 has a plurality of holes 54 that radially penetrate the outer wall. In this embodiment, a case where a pair of holes 54 is provided will be described. Note that the number of holes 54 is not limited to a pair. For example, the number of holes 54 is the same as the number of windows 22 of the first indicator 201. When the connecting member 42 is viewed from the outer periphery, for example, the holes 54 are formed in a rectangular shape. Note that the first indicator 201 is not limited to having the windows 22 and the second indicator 202 has the holes 54. For example, the first indicator 201 may be a first mark provided on the housing outer wall 121, and the second indicator 202 may be a second mark provided on the cap outer wall 162.

[0072] A plurality of grip portions 56 are provided spaced apart from one another in the circumferential direction of the main body tubular portion 481. The grip portions 56 protrude outward from the outer wall and extend along the axial direction of the connecting member 42. When a user grasps and operates the connecting member 42, the grip portions 56 make it easy to operate the connecting member 42.

[0073] As shown in FIG. 4 , the first rib 50 is provided at the tip of the main body tubular portion 481 and protrudes radially inward from the inner wall of the tip. The first rib 50 is provided in the tip direction (direction of arrow B) of the pair of holes 54. That is, the number of first ribs 50 is the same as the number of holes 54. Note that the number of first ribs 50 is not limited to the number of holes 54. For example, the number of first ribs 50 may be two or more. The first rib 50 may be annular along the circumferential direction of the connecting member 42. The inner surface of the first rib 50 is tapered toward the base end (direction of arrow A). The base end of the first rib 50 has a surface that intersects with the axial direction of the connecting member 42 (direction of arrows A and B).

[0074] The base end tubular portion 482 extends from the base end of the main body tubular portion 481 in the base end direction (direction of arrow A). The base end tubular portion 482 has a groove-forming portion 59 including an engagement groove 58. As shown in FIG. 6A , the engagement groove 58 extends circumferentially of the base end tubular portion 482. The engagement groove 58 is spiral-shaped about the axis of the connecting member 42. The engagement protrusion 24 of the housing 12 engages with the engagement groove 58. The groove-forming portion 59 is transparent. The engagement groove 58 is visible from outside the connecting member 42 through the groove-forming portion 59. Note that it is sufficient that at least the base end tubular portion 482 including the groove-forming portion 59 is transparent; for example, the entire connecting member 42, including the main body tubular portion 481, may be transparent.

[0075] 5 , the first connecting structure 44 connects the housing 12 and the connecting member 42. The first connecting structure 44 is an engagement structure in which the engagement protrusion 24 of the housing 12 and the engagement groove 58 of the connecting member 42 are engaged with each other. When the tip end of the housing 12 and the connecting member 42 are connected by the locking portion 18, the tip end of the housing 12 is inserted into the internal space 523 of the connecting member 42, and the engagement protrusion 24 is inserted into the engagement groove 58, thereby engaging with each other. The first connecting structure 44 creates a connected state in which movement of the connecting member 42 in the tip direction (axial direction) relative to the tip end of the housing 12 is prevented.

[0076] As shown in FIG. 6B , by rotating the connecting member 42 relative to the housing 12 around the axis of the housing 12, the engaging protrusion 24 can move along the engaging groove 58. As the connecting member 42 rotates, the connecting member 42 can move distally relative to the housing 12. The engaging protrusion 24 and the engaging groove 58 are disengaged, causing the connecting member 42 to move distally (in the direction of arrow B), and the engaging protrusion 24 of the housing 12 disengages from the engaging groove 58 of the connecting member 42. By moving the cap 16 distally (in the direction of arrow B) relative to the distal end of the housing 12, the first connecting structure 44 disengages the connecting member 42 from the housing 12, resulting in a first disconnected state. In the first disconnected state, the cap 16 is unlocked and can be removed from the distal end of the housing 12. The engaging groove 58 is formed so that the engaging protrusion 24 can be disengaged from the connecting member 42 when the connecting member 42 is rotated approximately 90° around the central axis of the housing 12, for example. The engagement groove 58 may be formed so that the engagement with the engagement protrusion 24 is released when the connecting member 42 is rotated 90 degrees or more around the central axis of the housing 12. The engagement groove 58 may be formed so that the engagement with the engagement protrusion 24 is released when the connecting member 42 is rotated less than 90 degrees around the central axis of the housing 12.

[0077] The engagement groove 58 constituting the first coupling structure 44 is not limited to being formed in a spiral shape. For example, the engagement groove 58 may have a circumferential groove portion extending in the circumferential direction of the base end tubular portion 482 and an axial groove portion extending from the end of the circumferential groove portion toward the base end of the base end tubular portion 482. In this case, the engagement protrusion 24 engages with the circumferential groove portion, thereby coupling the housing 12 and the coupling member 42 in the axial direction. The coupling member 42 can be released from the coupling with the housing 12 by rotating the coupling member 42 to move the engagement protrusion 24 along the axial groove portion and disengage it.

[0078] 4, the second connecting structure 46 connects the cap 16 and the connecting member 42. When the base end of the cap 16 is housed in the internal space 523 of the connecting member 42, the base end of the first rib 50 and the tip end of the second rib 40 face each other in the axial direction of the housing 12 (see FIG. 6C). The second connecting structure 46 is an abutment structure that allows the base end of the first rib 50 and the tip end of the second rib 40 to abut against each other when the cap 16 and the connecting member 42 move relative to each other in the axial direction.

[0079] Next, a case where the drug solution administration device 10A is used will be described. In the drug solution administration device 10A before use shown in Figure 1, the housing 12 and the cap 16 are axially connected by the connecting member 42 of the locking portion 18, so that the cap 16 cannot be accidentally removed from the tip of the housing 12.

[0080] First, the cap 16 is removed from the drug solution administration device 10A before use. Specifically, the connection between the housing 12 and the connecting member 42 by the first connecting structure 44 of the locking portion 18 is released.

[0081] With the locking portion 18 in the locked state shown in Fig. 6A , the housing 12 is fixed, and the connecting member 42 is rotated around the axis of the housing 12. As shown in Fig. 6B , as the connecting member 42 rotates, the engaging protrusion 24 moves along the engaging groove 58, causing the connecting member 42 to move distally (in the direction of arrow B) relative to the housing 12. As the connecting member 42 moves distally, the base end of the first rib 50 and the distal end of the second rib 40 in the second connecting structure 46 move away from each other in the axial direction.

[0082] When the engaging protrusion 24 of the housing 12 disengages from the engaging groove 58 of the connecting member 42, the engaging groove 58 and the engaging protrusion 24 are disengaged, and the connecting member 42 enters a first disconnected state in which the connecting member 42 can move distally relative to the distal end of the housing 12. At this time, the user can visually confirm from the outside of the connecting member 42 through the transparent groove forming portion 59 that the engaging groove 58 and the engaging protrusion 24 have been disengaged. In other words, the first connecting structure 44 enters the first disconnected state in which the connecting member 42 is no longer connected.

[0083] 6C , in the unlocked state, the first indicator 201 (window 22) and the second indicator 202 (hole 54) are arranged linearly in the axial direction of the housing 12 and the connecting member 42. The linear arrangement of the first and second indicators 201, 202 also makes it possible to visually confirm that the first disconnected state has been reached.

[0084] In the first disconnected state, the user grasps the cap 16 and pulls it in a direction (distal direction, arrow B) that separates it from the housing 12. This moves the cap 16 distally relative to the distal end of the housing 12, tilting the retaining arm 163 shown in FIG. 3 and disengaging the hook 164 from the recess 166. The retaining arm 163 (hook 164) is disengaged from the needle cover 28. As shown in FIG. 7 , the cap 16 is removed distally from the distal end of the housing 12. This opens the distal ends of the housing 12 and the needle cover 28, and simultaneously removes the protective cover 60 that covered the puncture needle 143 (see FIG. 8 ).

[0085] At this time, by pulling the cap 16 in the distal direction, the distal end of the second rib 40 abuts against the proximal end of the first rib 50, and the connecting member 42 is pulled in the distal direction together with the cap 16. Because the connecting member 42 and the cap 16 are connected by the second connecting structure 46, the connecting member 42 is removed from the housing 12 together with the cap 16. For example, the cap 16 and the connecting member 42 are discarded without being reused.

[0086] Next, a case where the medicinal liquid M is administered using the medicinal liquid administration device 10A with the cap 16 removed will be described.

[0087] As shown in Fig. 8 , when the cap 16 is removed from the drug solution administration device 10A, the tip of the needle cover 28 protrudes in the distal direction (direction of arrow B) from the tip of the housing 12. As shown in Fig. 9 , the tip of the needle cover 28 is pressed against the skin S of the living body that is to be punctured at a substantially right angle, and the housing 12 is further continuously pressed toward the skin S (distal direction, direction of arrow B). As the housing 12 is pressed toward the skin S, the needle cover 28 is pressed by the skin S and moves relative to the housing 12 in the proximal direction (direction of arrow A).

[0088] As the housing 12 is further pressed toward the skin S, the puncture needle 143 of the syringe 14 protrudes from the hole in the needle cover 28 toward the tip (in the direction of arrow B). This causes the puncture needle 143 to puncture the skin S and enter a puncture-completed state where it has been inserted to a predetermined depth. In the puncture-completed state, the tip of the housing 12 is in approximately the same position as the tip of the needle cover 28.

[0089] The plunger 34 is released from the locked state by a locking mechanism (not shown), and the plunger 34 begins to move toward the tip (in the direction of arrow B) due to the elastic force of the injection spring 36, and as the plunger 34 moves, the stopper 142 is inserted into the cylindrical body 141 of the syringe 14.

[0090] After the administration of medicinal liquid M has begun, plunger 34 continues to move continuously toward the distal end (in the direction of arrow B) at a constant speed due to the resilience of injection spring 36. Medicinal liquid M is pushed out by stopper 142, which moves toward the distal end within cylindrical body 141, and medicinal liquid M is discharged from puncture needle 143. A predetermined amount of medicinal liquid M within cylindrical body 141 is administered by plunger 34 through puncture needle 143 into skin S, completing the administration of medicinal liquid M.

[0091] The first embodiment has the following advantages.

[0092] 4, the drug solution administration device 10A includes a locking unit 18 that connects the cap 16 to the housing 12, and the locking unit 18 includes a first connecting structure 44 that connects the housing 12 to the connecting member 42, and a second connecting structure 46 that connects the cap 16 to the connecting member 42. As shown in FIG. 6B, by releasing the connection state of at least one of the first connecting structure 44 and the second connecting structure 46 (first connecting structure 44), the device enters an unlocked state in which the cap 16 can be removed from the housing 12.

[0093] As a result, when the locked state by the first connecting structure 44 or the second connecting structure 46 of the locking portion 18 is not released, the cap 16 is prevented from being removed from the tip of the housing 12. This reduces the occurrence of accidental punctures caused by accidentally removing the cap 16 from the tip of the housing 12.

[0094] 6A , the locking unit 18 is unlocked when the connecting member 42 is operated in a direction different from the axial direction of the housing 12. As a result, the operating direction of the connecting member 42 is different from the axial direction of the housing 12, making it difficult for the user to erroneously operate the connecting member 42. In other words, the locking unit 18 is a lock that can prevent the user from accidentally removing the cap 16 from the housing 12 of the medical solution administration device 10A before use.

[0095] As shown in Fig. 6B , by releasing the connection between the housing 12 and the connecting member 42 by the first connecting structure 44, an unlocked state can be achieved in which the cap 16 can be removed from the tip of the housing 12, as shown in Fig. 7 . When removing the cap 16 from the housing 12, the connecting member 42 is removed from the housing 12 together with the cap 16, while the cap 16 and the connecting member 42 are connected by the second connecting structure 46. As a result, when the connection by the first connecting structure 44 is released and the cap 16 is removed from the tip of the housing 12, the connecting member 42 can be removed together with the cap 16. Therefore, the second connecting structure 46 does not remain on the housing 12, and the connecting member 42 can be discarded together with the cap 16.

[0096] 6A, the connecting member 42 is a rotating member 42a formed in a cylindrical shape and provided rotatable about the axis of the housing 12, and is set in an unlocked state by rotating the rotating member 42a. This allows the connecting member 42 to be configured with a simple structure, thereby reducing costs.

[0097] As shown in FIG. 4 , the connecting member 42 has a first rib 50 protruding from the inner wall of the distal end portion having a distal opening 521, and an engagement groove 58 extending circumferentially on the inner wall of the proximal end portion having a proximal opening 522. As shown in FIG. 5 , the cap 16 has a second rib 40 provided at the proximal end portion and protruding from the cap outer wall 162, and the distal end portion of the housing 12 has an engagement protrusion 24 protruding from the housing outer wall 121. The first connecting structure 44 is an engagement structure in which the engagement protrusion 24 and the engagement groove 58 are engaged with each other, and the second connecting structure 46 is an abutment structure in which the proximal end of the first rib 50 and the distal end of the second rib 40 face each other in the axial direction of the housing 12 and the proximal end and the distal end can abut each other. As shown in FIG. 6B , by rotating the connecting member 42 relative to the housing 12, the engagement protrusion 24 disengages from the engagement groove 58, and the first connecting structure 44 is released from the connected state.

[0098] As a result, the first connecting structure 44 can effectively connect the housing 12 and the connecting member 42 by engaging the engaging protrusions 24 with the engaging grooves 58. The connection by the first connecting structure 44 can be easily released by rotating the connecting member 42 relative to the housing 12. When removing the cap 16 from the housing 12, the first rib 50 and the second rib 40 are brought into axial contact with each other, preventing the cap 16 from moving distally relative to the connecting member 42, and allowing the connecting member 42 to be removed together with the cap 16.

[0099] As shown in Fig. 6A , the engagement groove 58 of the connecting member 42 is spirally shaped around the axis of the connecting member 42. As shown in Fig. 6B , when the first connecting structure 44 is released from its connected state, the engagement protrusion 24 moves along the engagement groove 58, causing the connecting member 42 to move distally relative to the housing 12. When the cap 16 is removed distally relative to the housing 12, the base end of the first rib 50 and the distal end of the second rib 40 abut against each other. This allows the first connecting structure 44 to be easily released from its connected state by rotating the connecting member 42 relative to the housing 12. When the cap 16 is removed from the housing 12, the second connecting structure 46 allows the connecting member 42 to be easily removed together with the cap 16.

[0100] 6C , the housing 12 has a first indicator 201, and the connecting member 42 has a second indicator 202. By rotating the connecting member 42 relative to the housing 12, the first indicator 201 and the second indicator 202 are arranged linearly in the axial direction of the housing 12 and the connecting member 42, and a first disconnected state is achieved in which the connection by the first connecting structure 44 is released. As a result, when rotating the connecting member 42 relative to the housing 12, the user can easily visually confirm that the rotation of the connecting member 42 has been completed by the first and second indicators 201, 202 and the connection by the first connecting structure 44 has been released.

[0101] 1 , first indicator 201 is window 22 through which syringe 14 can be seen from outside housing 12, and second indicator 202 is hole 54 that penetrates the outer wall of connecting member 42. By utilizing window 22 provided for checking syringe 14, the manufacturing cost of medicinal solution administration device 10A can be reduced compared to a structure in which first indicator 201 is newly provided. By using hole 54 as second indicator 202, second indicator 202 can be easily provided on connecting member 42.

[0102] 6B , the connecting member 42 has a groove forming portion 59 with an engagement groove 58, and the groove forming portion 59 is transparent. This allows the user to check the engagement state between the engagement protrusion 24 and the engagement groove 58 from the outside of the connecting member 42 through the transparent groove forming portion 59, allowing the user to effectively check that the rotation of the connecting member 42 has been completed.

[0103] As shown in FIG. 10A , a medicinal solution administration device 101A according to a modified example of the first embodiment has a cap 16A, and a cap outer wall 162 of the cap 16A has an abutting portion 61. The abutting portion 61 can abut against the tip end of the connecting member 42. The abutting portion 61 is provided at the base end of the cap 16A. The abutting portion 61 is formed in an annular shape and has a rib-like shape that protrudes radially outward from the cap outer wall 162. The abutting portion 61 is perpendicular to the axial direction of the cap 16A. Note that the abutting portion 61 is not limited to being formed in an annular shape. For example, the abutting portion 61 may have a protruding shape that is provided on a portion of the cap 16A in the circumferential direction. When the housing 12 and the cap 16A are connected (locked) by the locking portion 18, the tip end of the connecting member 42 and the abutting portion 61 are disposed spaced apart in the axial direction of the housing 12.

[0104] When removing cap 16A from housing 12, connecting member 42 is rotated relative to housing 12, causing connecting member 42 to move toward the tip, and when engagement protrusion 24 disengages from engagement groove 58, the tip of connecting member 42 comes into contact with abutment portion 61, as shown in Fig. 10B . The movement of connecting member 42 toward the tip is prevented by abutment portion 61. When engagement protrusion 24 disengages from engagement groove 58, the locked state by first connecting structure 44 is released, and the first disconnected state is attained, the tip of connecting member 42 comes into contact with abutment portion 61.

[0105] The modified example of the first embodiment has the following effects.

[0106] By providing the abutment portion 61 on the cap outer wall 162 of the cap 16A, when the connection between the housing 12 and the connecting member 42 by the first connecting structure 44 is released, the user can recognize that the connecting member 42 has moved toward the tip and its tip has abutted against the abutment portion 61, thereby effectively confirming that the rotation of the connecting member 42 has completed and the connection by the first connecting structure 44 has been released, thereby entering the first disconnected state. Therefore, even if the groove forming portion 59 of the connecting member 42 is not transparent, the user can recognize that the connection state by the first connecting structure 44 has been released.

[0107] 11A, a drug solution administration device 10B according to the second embodiment includes a locking unit 181 that connects the cap 16 and the housing 12. As shown in Fig. 11B, the locking unit 181 includes a connecting member 421, a first connecting structure 441 that connects the housing 12 and the connecting member 421, and a second connecting structure 461 that connects the cap 16 and the connecting member 421.

[0108] 12 , in a locked state in which the housing 12 and the cap 16 are connected by the first and second connecting structures 441, 461, the connecting member 421 is provided on the cap outer wall 162 and is disposed straddling the base end of the cap 16 and the tip end of the housing 12. The connecting member 421 is a rotating member 421a that is rotatable about a vertical axis VL that is perpendicular to the axial direction of the housing 12. Rotating the rotating member 421a brings the housing 12 into an unlocked state in which the cap 16 can be removed from the tip end of the housing 12. In other words, the connecting member 421 brings the locking portion 181 into the unlocked state by being operated in a rotational direction that is different from the axial direction of the housing 12.

[0109] 11B , the tip end of the housing 12 has a first engagement protrusion 621 protruding from the housing outer wall 121, and a pedestal portion 622. The pedestal portion 622 is disposed in the proximal end direction (the direction of arrow A) of the first engagement protrusion 621. The pedestal portion 622 protrudes from the housing outer wall 121. The pedestal portion 622 extends in a direction perpendicular to the axial direction of the housing 12. The tip end surface of the pedestal portion 622 is flat.

[0110] The cap 16 has a second engagement protrusion 64 protruding from the cap outer wall 162. When the housing 12 and the cap 16 are connected by the locking portion 181, the first engagement protrusion 621 and the second engagement protrusion 64 are arranged in a straight line in the axial direction of the housing 12. Each of the first and second engagement protrusions 621, 64 has a pin portion 66 and a head portion 68 formed at the tip of the pin portion 66 and having a larger diameter than the pin portion 66. The protruding direction of the first and second engagement protrusions 621, 64 is perpendicular to the axial direction of the housing 12.

[0111] The rotating member 421a includes an inner member 70 and an outer cover 72. The inner member 70 includes a main body 701 and an engagement groove 702. In a plan view of the rotating member 421a, the main body 701 is formed in a circular shape. A portion of the main body 701 abuts against the surface of the base 622, thereby being supported.

[0112] 12 , the engagement groove 702 has a linear groove 74, a first engagement groove 761, and a second engagement groove 762. In a plan view of the rotating member 421a, the linear groove 74 is formed in a straight line passing through the center of the main body portion 701. The linear groove 74 has an open end 741 and a closed end 742. The open end 741 is formed at one end of the linear groove 74 and opens to the outer peripheral surface of the main body portion 701. The closed end 742 is formed at the other end of the linear groove 74 and is positioned more inward than the outer peripheral surface of the main body portion 701.

[0113] The first and second engagement grooves 761, 762 are formed in an arc shape along the outer circumferential surface of the main body portion 701. The first engagement groove 761 and the second engagement groove 762 are arranged on opposite sides with the linear groove 74 interposed therebetween.

[0114] The first engagement groove 761 engages with the first engagement protrusion 621. The pin portion 66 of the first engagement protrusion 621 is movably inserted into the first engagement groove 761. The first engagement groove 761 has an arc shape extending along the rotation direction of the rotating member 421a centered on the vertical axis VL. The first engagement groove 761 is connected to the approximate center of the linear groove 74 in the extension direction. The first engagement groove 761 and the linear groove 74 intersect at a connection portion. The first engagement groove 761 extends in an arc shape from the connection portion with the linear groove 74. In a locked state by the lock portion 181, the first engagement groove 761 is disposed to face the housing outer wall 121 of the housing 12.

[0115] The second engagement groove 762 engages with the second engagement protrusion 64. The pin portion 66 of the second engagement protrusion 64 is movably inserted into the second engagement groove 762. The second engagement groove 762 has an arc shape extending along the rotation direction of the rotating member 421a centered on the vertical axis VL. The second engagement groove 762 is connected to the linear groove 74 near the closed end 742. The second engagement groove 762 and the linear groove 74 intersect at a connection portion. The second engagement groove 762 extends in an arc shape from the connection portion with the linear groove 74. In a locked state by the locking portion 181, the second engagement groove 762 is positioned to face the cap outer wall 162 of the cap 16. The ends of the first and second engagement grooves 761, 762 extend to an imaginary line L perpendicular to the extension direction of the linear groove 74. The first and second connecting structures 441, 461 create a locked state in which relative movement between the housing 12 and the cap 16 in the axial direction is prevented.

[0116] The outer cover 72 is grasped by the user when operating the connecting member 421. The outer cover 72 covers the inner member 70. The outer cover 72 is formed in a regular hexagonal shape in a plan view. However, the shape of the outer cover 72 is not limited to a regular hexagonal shape. There are no particular limitations on the shape as long as it is a support shape that can be grasped by the user and can be rotated around the vertical axis VL. The inner member 70 is housed inside the outer cover 72. When the inner member 70 is engaged with the outer cover 72, the inner member 70 and the outer cover 72 can rotate together.

[0117] The first connecting structure 441 is an engaging structure between the first engaging protrusion 621 of the housing 12 and the first engaging groove 761 of the connecting member 421. The second connecting structure 461 is a fixing structure between the connecting member 421 and the cap 16.

[0118] When the user operates the connecting member 421 so that the first engagement protrusion 621 moves along the first engagement groove 761 and the second engagement protrusion 64 moves along the second engagement groove 762, the connecting member 421 rotates around a vertical axis VL that is perpendicular to the axial direction of the housing 12.

[0119] When releasing the connection between the housing 12 and the connecting member 421 by the first connecting structure 441 of the locking portion 181, the user grasps the connecting member 421 and rotates it in the first direction R about the vertical axis VL from the locked state of the locking portion 181 shown in FIG. 12 . As shown in FIG. 13A , the rotation of the connecting member 421 causes the first engagement protrusion 621 to move along the first engagement groove 761 toward the linear groove 74, and the second engagement protrusion 64 to move along the second engagement groove 762 toward the linear groove 74. When the first engagement protrusion 621 disengages from the first engagement groove 761 and reaches the linear groove 74, the connection by the first connecting structure 441 is released, resulting in a first release state. The second engagement protrusion 64 disengages from the second engagement groove 762 and reaches the vicinity of the closed end 742 of the linear groove 74.

[0120] 13B , when the user grips the cap 16 and pulls it in the distal direction (direction of arrow B) relative to the housing 12, the first engagement protrusion 621 moves along the linear groove 74 and disengages from the linear groove 74 through the open end 741. This separates the connecting member 421 from the housing 12. When the user pulls the cap 16 in the distal direction relative to the housing 12, the connecting member 421 is pulled in the distal direction together with the cap 16, with the second engagement protrusion 64 hooked onto the closed end 742 of the second engagement groove 762. In other words, the connecting member 421 is removed from the housing 12 together with the cap 16, while the connection between the cap 16 and the connecting member 421 by the second connecting structure 461 is maintained.

[0121] The second embodiment has the following advantages.

[0122] 12 , the connecting member 421 is a rotating member 421a that is provided across the base end of the cap 16 and the tip end of the housing 12 and is rotatable about a vertical axis VL that is perpendicular to the axial direction of the housing 12. As shown in FIG. 13A , by rotating the rotating member 421a, an unlocked state is established in which the cap 16 can be removed from the housing 12. By configuring the connecting member 421 as the rotating member 421a that is rotatable about the vertical axis VL that is perpendicular to the axial direction of the housing 12, the connecting member 421 can be configured with a simple structure, which allows for cost reduction.

[0123] 11B , the tip end of the housing 12 has a first engagement protrusion 621 protruding from the housing outer wall 121, and the connecting member 421 has a first engagement groove 761 with which the first engagement protrusion 621 is engaged, the first engagement groove 761 extending along the rotation direction around the vertical axis VL. The first connecting structure 441 is an engagement structure between the first engagement protrusion 621 and the first engagement groove 761, and the second connecting structure 461 is a fixing structure between the connecting member 421 and the cap 16.

[0124] 13B , when the connection state of the first connection structure 441 is released and the cap 16 is removed, the connection member 421 connected to the cap 16 by the second connection structure 461 can be removed together. This prevents the connection member 421 from remaining in the housing 12, and allows the connection member 421 to be discarded together with the cap 16. The connection between the housing 12 and the connection member 421 by the first connection structure 441 can be easily released by rotating the connection member 421 about the vertical axis VL.

[0125] 11B, the cap 16 has a second engagement protrusion 64 protruding from the cap outer wall 162, and the connecting member 421 has a second engagement groove 762 with which the second engagement protrusion 64 engages. As shown in FIG. 13A, by rotating the connecting member 421 about the vertical axis VL, the second engagement protrusion 64 moves along the second engagement groove 762.

[0126] As a result, when the connecting member 421 is rotated around the vertical axis VL, the second engaging protrusion 64 moves along the second engaging groove 762, thereby effectively stabilizing the rotation of the connecting member 421.

[0127] The locking unit 181 is set to an unlocked state by operating the connecting member 421 in a rotational direction about the vertical axis VL, which is different from the axial direction of the housing 12. As a result, the operating direction of the connecting member 421 is different from the axial direction of the housing 12, making it difficult for the user to operate the connecting member 421 erroneously.

[0128] When the locking portion 181 is set to the unlocked state, only the connected state of the first connecting structure 441 may be released, and the connecting member 421 may not be removed together with the cap 16. For example, as shown in Fig. 13B , after the first connecting structure 441 is released from its connected state to set up a first disconnected state, the second engaging protrusion 64 may be disengaged from the linear groove 74 to set up a second disconnected state in which the connection between the connecting member 421 and the cap 16 by the second connecting structure 461 is released.

[0129] 13B , when the cap 16 is to be removed from the housing 12, the connecting member 421 can be removed from the cap 16 by further moving the connecting member 421 toward the tip (in the direction of arrow B) relative to the cap 16. In other words, the connected states of the first and second connecting structures 441, 461 can be released, and the connecting member 421 can be removed from both the housing 12 and the cap 16.

[0130] 14A, a drug solution administration device 10C according to the third embodiment includes a locking unit 182 that connects the cap 16 and the housing 12. As shown in Fig. 14B, the locking unit 182 includes a connecting member 422, a first connecting structure 442 that connects the housing 12 and the connecting member 422, and a second connecting structure 462 that connects the cap 16 and the connecting member 422.

[0131] As shown in FIG. 15 , in a locked state in which the housing 12 and the cap 16 are connected by the first and second connecting structures 442, 462, the connecting member 422 is disposed between the base end of the cap 16 and the tip end of the housing 12. The connecting member 422 is a slide member 422a that is slidable in a transverse direction (direction of arrow C in FIG. 15 ) that intersects the axial direction of the housing 12 (direction of arrows A and B). By moving the slide member 422a in the transverse direction (direction of arrow C), the cap 16 enters an unlocked state in which it can be removed from the housing 12. That is, the connecting member 422 enters the unlocked state by operating in the transverse direction (direction of arrow C), which is a direction different from the axial direction of the housing 12. Note that the following description will be given of a configuration in which the connecting member 422 is movable in a direction perpendicular to the axial direction of the housing 12.

[0132] 14B, the tip of the housing 12 has a first engagement protrusion 621 protruding from the housing outer wall 121. The cap 16 has a second engagement protrusion 64 protruding from the cap outer wall 162.

[0133] The slide member 422a includes an inner member 80 and an outer cover 82. The inner member 80 includes a main body 801 and an engagement groove 802. As shown in Fig. 15, in a plan view of the slide member 422a, the main body 801 is formed in a rectangular shape that is elongated in the axial direction of the housing 12. Note that the main body 801 is not limited to being formed in a rectangular shape.

[0134] 15 , the main body 801 includes a storage portion 84 and a locking wall 86. The storage portion 84 is provided at one end in the movement direction of the slide member 422a. The storage portion 84 has a space provided on one side in a direction intersecting the axial direction of the housing 12. The locking wall 86 is disposed in a distal direction facing the storage portion 84 in the axial direction of the housing 12. The locking wall 86 protrudes on one side in a direction intersecting the axial direction of the housing 12. When the cap 16 and the housing 12 are connected, the locking wall 86 faces the cap outer wall 162 of the cap 16 and is disposed distally of the second engagement protrusion 64.

[0135] The engagement groove 802 has a first engagement groove 881 and a second engagement groove 882. Each of the first and second engagement grooves 881, 882 extends in a direction perpendicular to the axial direction of the housing 12. In other words, each of the first and second engagement grooves 881, 882 extends along the movement direction of the connecting member 422.

[0136] Each of the first and second engagement grooves 881, 882 has an open end 901 and a closed end 902. The open end 901 is one end of each of the first and second engagement grooves 881, 882 in the extension direction. The open end 901 opens to face the accommodation portion 84. The closed end 902 is the other end of each of the first and second engagement grooves 881, 882 in the extension direction. Each of the first and second engagement grooves 881, 882 is formed linearly along the movement direction of the connecting member 422. The first engagement groove 881 and the second engagement groove 882 are parallel to each other. In a locked state by the locking portion 182, the first engagement groove 881 is positioned to face the housing outer wall 121 of the housing 12, and the second engagement groove 882 is positioned to face the cap outer wall 162 of the cap 16. In the movement direction of the connecting member 422, the length of the second engagement groove 882 is longer than the length of the first engagement groove 881. In other words, the open end 901 of the second engagement groove 882 is positioned closer to the accommodating portion 84 than the open end 901 of the first engagement groove 881.

[0137] The first engagement protrusion 621 engages with the first engagement groove 881. The pin portion 66 of the first engagement protrusion 621 is movably inserted into the first engagement groove 881. The second engagement protrusion 64 engages with the second engagement groove 882. The pin portion 66 of the second engagement protrusion 64 is movably inserted into the second engagement groove 882. As shown in FIG. 15 , in the locked state by the lock portion 182, the first engagement protrusion 621 is disposed at the closed end 902 of the first engagement groove 881, and the second engagement protrusion 64 is disposed at the closed end 902 of the second engagement groove 882. The first and second coupling structures 442, 462 enter a locked state in which relative movement between the housing 12 and the cap 16 in the axial direction is prevented.

[0138] The outer cover 82 is gripped by the user when operating the connecting member 422. The outer cover 82 covers the inner member 80. The inner member 80 is housed and held inside the outer cover 82. A mark 92 indicating the operating direction of the connecting member 422 is provided on the surface of the outer cover 82. The mark 92 is, for example, an arrow. The indicating direction of the mark 92 is a direction perpendicular to the axial direction of the housing 12. Note that the connecting member 422 is not limited to being provided with the mark 92.

[0139] The first connecting structure 442 is an engaging structure between the first engaging protrusion 621 of the housing 12 and the first engaging groove 881 of the connecting member 422. The second connecting structure 462 is a fixing structure between the connecting member 422 and the cap 16.

[0140] To release the connection between the housing 12 and the connecting member 422 by the first connecting structure 442 of the locking portion 182, as shown in FIG. 16A , the user slides the connecting member 422 in a transverse direction (the direction of arrow C) perpendicular to the axial direction of the housing 12. The transverse direction (the direction of arrow C) is the direction indicated by the mark 92 on the outer cover 82. By sliding the connecting member 422, the first engaging protrusion 621 moves along the first engaging groove 881 toward the open end 901, and the second engaging protrusion 64 moves along the second engaging groove 882 toward the open end 901. When the first engaging protrusion 621 disengages from the first engaging groove 881 and reaches the storage portion 84, the connection by the first connecting structure 442 is released, resulting in a first disconnected state. At this time, the second engaging protrusion 64 remains engaged with the second engaging groove 882.

[0141] When the user grasps the cap 16 and pulls it distally relative to the housing 12 as shown in FIG. 16B , the connecting member 422 moves away from the housing 12 distally. This releases the connection between the cap 16 and the housing 12 by the first connecting structure 442, resulting in an unlocked state (first disconnected state). By pulling the cap 16 distally relative to the housing 12, the second engagement protrusion 64 disengages from the open end 901 of the second engagement groove 882 and moves to the storage portion 84. As the second engagement protrusion 64 moves distally relative to the connecting member 422, the second engagement protrusion 64 abuts against the locking wall 86. The second engagement protrusion 64 moves the connecting member 422 distally together with the cap 16 via the locking wall 86. This causes the connecting member 422 to be removed from the housing 12 together with the cap 16, while the connected state by the second connecting structure 462 is maintained.

[0142] The third embodiment has the following advantages.

[0143] 15 , the connecting member 422 is a sliding member 422a that is provided between the base end of the cap 16 and the tip end of the housing 12 and is slidable in a direction intersecting the axial direction of the housing 12 (the direction of arrow C). This allows the connecting member 422 to be configured with a simple structure, which makes it possible to reduce costs.

[0144] 14B , the tip of the housing 12 has a first engagement protrusion 621 protruding from the housing outer wall 121, and as shown in Fig. 15 , the connecting member 422 has a first engagement groove 881 that extends along the intersecting direction (the direction of arrow C) and engages with the first engagement protrusion 621. The first connecting structure 442 is an engagement structure between the first engagement protrusion 621 and the first engagement groove 881, and the second connecting structure 462 is a fixing structure between the connecting member 422 and the cap 16.

[0145] 16B , when the connection state by first connection structure 442 is released and cap 16 is removed from housing 12, connecting member 422 connected by second connection structure 462 can be removed together with cap 16. As a result, connecting member 422 does not remain in housing 12, and can be discarded together with cap 16. By sliding connecting member 422 in the intersecting direction (direction of arrow C), the connection between housing 12 and connecting member 422 by first connection structure 442 can be easily released.

[0146] 14B, the cap 16 has a second engagement protrusion 64 protruding from the cap outer wall 162, and as shown in Fig. 15, the connecting member 422 has a second engagement groove 882 that extends along the intersecting direction (the direction of arrow C) and engages with the second engagement protrusion 64. As shown in Fig. 16A, by moving the connecting member 422 in the intersecting direction (the direction of arrow C), the second engagement protrusion 64 moves along the second engagement groove 882.

[0147] As a result, when the connecting member 422 is slid in the intersecting direction (the direction of arrow C), the second engaging protrusion 64 moves along the second engaging groove 882, thereby stabilizing the movement of the connecting member 422.

[0148] 16A , locking section 182 is set to the unlocked state when at least a portion of connecting member 422 is operated in a direction different from the axial direction of housing 12. As a result, the operating direction of connecting member 422 is a direction different from the axial direction of housing 12, making it difficult for a user to operate connecting member 422 erroneously.

[0149] Note that the connecting member 422 is not limited to only releasing the connection by the first connecting structure 442 and being removed together with the cap 16. For example, the connected states of the first connecting structure 442 and the second connecting structure 462 in the locking portion 182 may both be released.

[0150] 17 , in a chemical solution administration device 101C according to a modification of the third embodiment, a connecting member 422b of a locking portion 182b includes an inner member 80b. The inner member 80b includes an engagement groove 802b, which has a first engagement groove 881b and a second engagement groove 882b. In the movement direction of the connecting member 422b, the length of the first engagement groove 881b and the length of the second engagement groove 882b are the same.

[0151] When the connection between the housing 12 and the connecting member 422b by the lock portion 182b is released, as shown in FIG. 18A , the connecting member 422b is slid in the intersecting direction (the direction of arrow C), whereby the first engagement protrusion 621 moves along the first engagement groove 881b toward the open end 901, and the second engagement protrusion 64 moves along the second engagement groove 882b toward the open end 901. When the first engagement protrusion 621 leaves the first engagement groove 881b and reaches the accommodation portion 84, the connection by the first connecting structure 442 is released, resulting in a first released state. When the second engagement protrusion 64 leaves the second engagement groove 882b and reaches the accommodation portion 84, the connection by the second connecting structure 462 is released, resulting in a second released state. Because the first and second engagement grooves 881b, 882b have the same length, the connection between the first and second connecting structures 442, 462 is released substantially simultaneously.

[0152] As shown in FIG. 18B, after the connecting member 422b is detached from the housing 12 and the cap 16, the cap 16 is removed from the housing 12 by pulling the cap 16 in the distal direction relative to the housing 12.

[0153] The modified example of the third embodiment has the following effects.

[0154] 18B , when the connection state of the first connecting structure 442 is released and the cap 16 is removed from the housing 12, the connecting member 422b connected to the cap 16 by the second connecting structure 462 can be removed together. This prevents the second connecting structure 462 from remaining on the housing 12, and allows the connecting member 422b to be discarded together with the cap 16. By sliding the connecting member 422b in the cross direction, the connection between the housing 12 and the connecting member 422b by the first connecting structure 442 can be easily released.

[0155] 19 , a chemical solution administration device 10D according to the fourth embodiment includes a locking unit 183 that connects the cap 16 and the housing 12. As shown in FIG. 20 , the locking unit 183 includes a connecting member 423, a first connecting structure 443 that connects the housing 12 and the connecting member 423, and a second connecting structure 463 that connects the cap 16 and the connecting member 423.

[0156] In a locked state in which the housing 12 and the cap 16 are connected by the first and second connecting structures 443, 463, the connecting member 423 is provided on the cap outer wall 162 and the housing outer wall 121 and is disposed straddling the base end of the cap 16 and the tip end of the housing 12. The connecting member 423 is provided so as to be detachable from at least one of the cap 16 and the housing 12. Removing the connecting member 423 from either the cap 16 or the housing 12 brings the cap 16 into an unlocked state in which it can be removed from the housing 12. The removal direction of the connecting member 423 is a direction away from the housing outer wall 121 and the cap outer wall 162 (see FIG. 21 ). In other words, the connecting member 423 brings the locking portion 183 into an unlocked state by operating it in a direction different from the axial direction of the housing 12.

[0157] 20 , the connecting member 423 is an elastically deformable plate-like member 423a. The plate-like member 423a is formed of, for example, rubber or a resin material. The connecting member 423 has a rectangular shape that is longer in the longitudinal direction than in the width direction perpendicular to the longitudinal direction. Note that the material of the plate-like member 423a is not limited to rubber or a resin material.

[0158] The connecting member 423 has a first end 1001 provided at one longitudinal end and a second end 1002 provided at the other longitudinal end. The first end 1001 is disposed to face the housing outer wall 121 of the housing 12. The second end 1002 is disposed to face the cap outer wall 162 of the cap 16.

[0159] The connecting member 423 has a first engagement hole 1021 and a second engagement hole 1022. The first engagement hole 1021 and the second engagement hole 1022 are spaced apart in the longitudinal direction of the connecting member 423. The first engagement hole 1021 engages with the first engagement protrusion 621 of the housing outer wall 121. The diameter of the first engagement hole 1021 is smaller than the diameter of the head 68 of the first engagement protrusion 621. The first engagement hole 1021 is positioned closer to the first end 1001 than the longitudinal center of the connecting member 423. The second engagement hole 1022 engages with the second engagement protrusion 64 of the cap outer wall 162. The diameter of the second engagement hole 1022 is smaller than the diameter of the head 68 of the second engagement protrusion 64. The second engagement hole 1022 is positioned closer to the second end 1002 than the longitudinal center of the connecting member 423.

[0160] The connecting member 423 includes first to third slits 1041, 1042, and 1043. Each of the first to third slits 1041, 1042, and 1043 extends along the longitudinal direction of the connecting member 423 and penetrates through the connecting member 423 in the thickness direction. The first slit 1041 extends between the first engagement hole 1021 and the second engagement hole 1022, and connects the first engagement hole 1021 and the second engagement hole 1022.

[0161] The second slit 1042 is provided in the opposite direction from the first slit 1041 with respect to the first engagement hole 1021. The second slit 1042 is formed to be connected to the first engagement hole 1021. The third slit 1043 is provided in the opposite direction from the first slit 1041 with respect to the second engagement hole 1022. The third slit 1043 is formed to be connected to the second engagement hole 1022. Note that the connecting member 423 is not limited to having the second and third slits 1042, 1043. For example, the connecting member 423 may be configured to have only the first slit 1041 between the first engagement hole 1021 and the second engagement hole 1022. Alternatively, the connecting member 423 may be configured to have only the second and third slits 1042, 1043 without having the first slit 1041. Furthermore, the connecting member 423 does not necessarily have to include all of the first to third slits 1041 , 1042 , and 1043 .

[0162] The first coupling structure 443 is an engagement structure in which the first engagement protrusion 621 is engaged with the first engagement hole 1021. As shown in FIG. 22A , by detaching the coupling member 423 from the housing 12, the first engagement protrusion 621 is disengaged from the first engagement hole 1021, resulting in a first disconnected state in which the coupling state by the first coupling structure 443 is released. The second coupling structure 463 is an engagement structure in which the second engagement protrusion 64 is engaged with the second engagement hole 1022. As shown in FIG. 22B , by detaching the coupling member 423 from the cap 16, the second engagement protrusion 64 is disengaged from the second engagement hole 1022, resulting in a second disconnected state in which the coupling state by the second coupling structure 463 is released.

[0163] To release the connection between the housing 12 and the connecting member 423 by the first connecting structure 443 of the locking portion 183, as shown in FIG. 21 , the user grasps the first end 1001 and pulls the connecting member 423 in a direction away from the housing outer wall 121. By moving the first end 1001 of the connecting member 423 away from the housing 12, the head 68 of the first engaging protrusion 621 pushes open the first engaging hole 1021 through the first and second slits 1041, 1042. The head 68 of the first engaging protrusion 621 passes through the expanded first engaging hole 1021, thereby disengaging the first engaging protrusion 621 from the first engaging hole 1021. As shown in FIG. 22A , the connection between the housing 12 and the cap 16 by the first connecting structure 443 is released, resulting in a first disconnected state. By moving the cap 16 toward the distal end, the cap 16 is removed from the distal end of the housing 12. At this time, the connecting member 423 is removed from the housing 12 together with the cap 16 by the second connecting structure 463 .

[0164] As shown in FIG. 22B , to release the connection between the first connecting structure 443 and the second connecting structure 463 of the locking portion 183, the user pulls the first end 1001 of the connecting member 423 upward in a direction away from the housing outer wall 121, releasing the engagement of the first engaging protrusion 621 with the first engaging hole 1021. Then, the user pulls the second end 1002 of the connecting member 423 upward in a direction away from the cap 16. The head 68 of the second engaging protrusion 64 pushes open the second engaging hole 1022 through the first and third slits 1041 and 1043. The head 68 of the second engaging protrusion 64 passes through the expanded second engaging hole 1022, thereby disengaging the second engaging protrusion 64 from the second engaging hole 1022. This releases the connection between the connecting member 423 and the cap 16 via the second connecting structure 463, resulting in a second disconnected state. The connecting member 423 is then removed from the housing 12 and the cap 16.

[0165] When both the first and second connecting structures 443 and 463 are released from the connected state, there is no particular limitation on the order in which the first connecting structure 443 and the second connecting structure 463 are released from the connected state. For example, the connection between the connecting member 423 and the cap 16 by the second connecting structure 463 may be released first, and then the connection between the connecting member 423 and the housing 12 by the first connecting structure 443 may be released.

[0166] The locking portion 183 is not limited to releasing the connected state by the first connecting structure 443. It may be possible to release only the connected state between the connecting member 423 and the cap 16 by the second connecting structure 463 while maintaining the connected state by the first connecting structure 443. In this case, in an unlocked state in which the cap 16 can be removed from the housing 12, the connecting member 423 remains connected to the housing 12.

[0167] The fourth embodiment has the following advantages.

[0168] 20 , the connecting member 423 is a plate-like member 423a that is provided across the base end of the cap 16 and the tip end of the housing 12 and is detachable from at least one of the cap 16 and the housing 12. By detaching the plate-like member 423a from either the cap 16 or the housing 12, an unlocked state is established in which the cap 16 can be detached from the housing 12. This allows the connecting member 423 to be configured with a simple structure, thereby reducing costs.

[0169] The connecting member 423 is a plate-like member 423a having a first engaging hole 1021 with which the first engaging protrusion 621 engages and a second engaging hole 1022 with which the second engaging protrusion 64 engages. The first connecting structure 443 is an engaging structure in which the first engaging protrusion 621 engages with the first engaging hole 1021, and the second connecting structure 463 is an engaging structure in which the second engaging protrusion 64 engages with the second engaging hole 1022.

[0170] As a result, by removing the connecting member 423 from the housing 12, the connection between the connecting member 423 and the housing 12 by the first connecting structure 443 can be released, and by removing the connecting member 423 from the cap 16, the connection between the connecting member 423 and the cap 16 by the second connecting structure 463 can be released. Therefore, the user can select how to handle the connecting member 423 after the connection state by the locking portion 183 has been released.

[0171] 21 , in an unlocked state in which the housing 12 and the cap 16 are detachable, the detached state of one of the first connecting structure 443 and the second connecting structure 463 (first connecting structure 443) is released, and the detached state of the other of the first connecting structure 443 and the second connecting structure 463 (second connecting structure 463) is maintained. In this way, by maintaining the detached state of the other of the first and second connecting structures 443, 463, it is possible to select whether to detach and discard the connecting member 423 together with the cap 16, or to leave the connecting member 423 attached to the housing 12.

[0172] 22B , in the unlocked state, the connection states of the first connection structure 443 and the second connection structure 463 are both released, resulting in a first disconnected state and a second disconnected state. This makes it possible to remove the cap 16 from the housing 12 without the connection member 423 remaining on either the cap 16 or the housing 12.

[0173] 20 , the connecting member 423 has a first slit 1041 extending between the first engagement hole 1021 and the second engagement hole 1022, and the first slit 1041 connects the first engagement hole 1021 and the second engagement hole 1022. As a result, when the first engagement protrusion 621 is to be removed from the first engagement hole 1021, the first slit 1041 makes it easy to remove the first engagement protrusion 621, facilitating removal of the connecting member 423. When the second engagement protrusion 64 is to be removed from the second engagement hole 1022, the first slit 1041 makes it easy to remove the second engagement protrusion 64, facilitating removal of the connecting member 423.

[0174] The connecting member 423 has a second slit 1042 that is provided in the opposite direction to the first slit 1041 relative to the first engagement hole 1021, and a third slit 1043 that is provided in the opposite direction to the first slit 1041 relative to the second engagement hole 1022, with the second slit 1042 being formed in connection with the first engagement hole 1021 and the third slit 1043 being formed in connection with the second engagement hole 1022.

[0175] Thus, by providing the second and third slits 1042, 1043 in addition to the first slit 1041, the first and second engaging protrusions 621, 64 can be more effectively released from the first and second engaging holes 1021, 1022. This makes it even easier to remove the connecting member 423.

[0176] 21 , the locking portion 183 is set to an unlocked state when the connecting member 423 is operated in a direction different from the axial direction of the housing 12. As a result, the operating direction of the connecting member 423 is a direction different from the axial direction of the housing 12, making it difficult for the user to operate the connecting member 423 erroneously.

[0177] Furthermore, the connecting member 423 is not limited to a configuration formed from a plate-like member 423a that can engage with the first and second engaging protrusions 621, 64. For example, it may be a seal-like connecting member that is attached so as to straddle the tip end of the housing 12 and the base end of the cap 16. By peeling the connecting member from at least one of the tip end of the housing 12 and the base end of the cap 16, it is possible to set the housing 12 and the cap 16 to an unlocked state in which they can be removed.

[0178] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention.

Claims

1. A drug solution administration device for administering the drug solution into a living body, comprising: a housing formed in a hollow cylindrical shape; a syringe that is housed within the housing and has a cylindrical body that is filled with a drug solution and a puncture needle that communicates with the cylindrical body and administers the drug solution into a living body; and a cap that is provided at the tip of the housing and is removed when the puncture needle punctures a subject to be punctured, wherein the drug solution administration device has a locking unit that connects the cap and the housing, and the locking unit has a connecting member, a first connecting structure that connects the housing and the connecting member, and a second connecting structure that connects the cap and the connecting member, and by releasing the connected state of at least one of the first connecting structure and the second connecting structure, the drug solution administration device enters an unlocked state in which the cap can be removed from the housing.

2. A drug solution administration device according to claim 1, wherein the locking section is set to the unlocked state when at least a portion of the connecting member is operated in a direction different from the axial direction of the housing.

3. A drug solution administration device as claimed in claim 1 or 2, wherein the unlocked state is achieved by releasing the connection between the housing and the connecting member by the first connecting structure, and when the cap is removed from the housing, the connecting member is removed from the housing together with the cap while the cap and the connecting member are connected by the second connecting structure.

4. A drug solution administration device according to claim 1, wherein the connecting member is a rotating member formed in a cylindrical shape and rotatable about the axis of the housing, and the drug solution administration device is set in the unlocked state by rotating the rotating member.

5. In the drug solution administration device according to claim 2, the connecting member is formed in a hollow cylindrical shape having a distal opening and a proximal opening, the cap is inserted into the distal opening, the housing is inserted into the proximal opening, and an internal space is provided in which the cap and the housing are housed; the connecting member has a first rib protruding from the inner wall of the distal end portion having the distal opening, and an engaging groove extending circumferentially and provided on the inner wall of the proximal end portion having the proximal opening; the cap has a second rib provided at the proximal end portion and protruding from the outer wall of the cap; the distal end portion of the housing has an engaging protrusion protruding from the outer wall of the housing; the first connecting structure is an engaging structure in which the engaging protrusion and the engaging groove are engaged with each other; and the second connecting structure is an abutting structure in which the proximal end portion of the first rib and the distal end portion of the second rib face each other in the axial direction of the housing, and the proximal end portion and the distal end portion can abut against each other; A drug solution administration device in which, by rotating the connecting member relative to the housing around the axis of the housing, the engaging protrusion of the housing disengages from the engaging groove of the connecting member, and the connected state of the first connecting structure is released to a first disconnected state.

6. A drug solution administration device as described in claim 5, wherein the engagement groove of the connecting member is spirally shaped around the axis of the connecting member, and when the first connecting structure is released from the connected state, the engagement protrusion moves along the engagement groove, causing the connecting member to move in the distal direction relative to the housing, and the base end of the first rib and the tip end of the second rib in the second connecting structure are separated, and when the cap is removed in the distal direction relative to the housing, the base end of the first rib and the tip end of the second rib abut against each other.

7. A medicinal liquid administration device as described in claim 5, wherein the housing has a first indicator, and the connecting member has a second indicator, and by rotating the connecting member relative to the housing around the axis of the housing, the first indicator and the second indicator are arranged in a straight line in the axial direction of the housing and the connecting member, and the engaging protrusion of the housing disengages from the engaging groove of the connecting member, thereby releasing the connection by the first connecting structure and entering the first disconnected state.

8. A medicinal liquid administration device according to claim 7, wherein the first indicator is a window through which the syringe can be seen from outside the housing, and the second indicator is a hole that penetrates the outer wall of the connecting member.

9. A drug solution administration device as described in claim 5, wherein the connecting member has a groove forming portion with the engagement groove, and at least the groove forming portion is transparent, so that the engagement groove can be seen from outside the connecting member through the groove forming portion.

10. A medicinal liquid administration device as described in claim 6, wherein in the first disconnected state in which the engaging protrusion of the housing disengages from the engaging groove of the connecting member and the first connecting structure is released, the cap has an abutment portion that abuts against the tip end of the connecting member.

11. A drug solution administration device as described in claim 1, wherein the connecting member is a rotating member that is provided across the base end of the cap and the tip end of the housing, and is rotatable around a vertical axis that is perpendicular to the axial direction of the housing, and the drug solution administration device enters the unlocked state by rotating the rotating member.

12. A medicinal liquid administration device as described in claim 2, wherein, when the housing and the cap are connected by the first connecting structure and the second connecting structure, the connecting member is provided on the outer wall of the cap so as to straddle the base end of the cap and the tip end of the housing, the connecting member is provided on the outer wall of the cap so as to be rotatable around a vertical axis perpendicular to the axial direction of the housing, the tip end of the housing has a first engaging protrusion protruding from the outer wall of the housing, the connecting member has a first engaging groove with which the first engaging protrusion engages, and the first engaging groove extends along the rotation direction around the vertical axis, the first connecting structure is an engaging structure between the first engaging protrusion and the first engaging groove, and the second connecting structure is a fixing structure between the connecting member and the cap, and by rotating the connecting member around the vertical axis, the first engaging protrusion disengages from the first engaging groove, thereby achieving a first disconnected state in which the first connecting structure is released.

13. A medicinal liquid administration device as described in claim 12, wherein the cap has a second engagement protrusion protruding from the outer wall of the cap, the connecting member has a second engagement groove with which the second engagement protrusion engages, the second engagement groove extending along the rotation direction centered on the vertical axis, and the second engagement protrusion moves along the second engagement groove by rotating the connecting member centered on the vertical axis.

14. A medicinal liquid administration device as described in claim 13, wherein by rotating the connecting member around the vertical axis, the second engaging protrusion disengages from the second engaging groove, and the connection between the connecting member and the cap by the second connecting structure is released, resulting in a second disconnected state.

15. A drug solution administration device as described in claim 1, wherein the connecting member is a sliding member that is provided across the base end of the cap and the tip end of the housing, and is slidable in a transverse direction that intersects with the axial direction of the housing, and the unlocked state is achieved by moving the sliding member in the transverse direction.

16. A medicinal liquid administration device as described in claim 2, wherein, when the housing and the cap are connected by the first connecting structure and the second connecting structure, the connecting member is provided straddling the base end of the cap and the tip end of the housing, the connecting member is provided on the outer wall of the cap so as to be slidable in a transverse direction that intersects the axial direction of the housing and follows the outer wall of the housing, the tip end of the housing has a first engaging protrusion protruding from the outer wall of the housing, the connecting member has a first engaging groove with which the first engaging protrusion engages, the first engaging groove extending along the transverse direction, the first connecting structure is an engaging structure between the first engaging protrusion and the first engaging groove, and the second connecting structure is a fixing structure between the connecting member and the cap, and by moving the connecting member in the transverse direction, the first engaging protrusion disengages from the first engaging groove, thereby achieving a first disconnected state in which the first connecting structure is released.

17. A medicinal liquid administration device as described in claim 16, wherein the cap has a second engagement protrusion protruding from the outer wall of the cap, the connecting member has a second engagement groove with which the second engagement protrusion engages, the second engagement groove extending along the intersecting direction, and the second engagement protrusion moves along the second engagement groove by moving the connecting member in the intersecting direction.

18. A medicinal liquid administration device as described in claim 17, wherein, by moving the connecting member in the intersecting direction, the second engaging protrusion disengages from the second engaging groove, and the connection between the connecting member and the cap by the second connecting structure is released, resulting in a second disconnected state.

19. A drug solution administration device as described in claim 1, wherein the connecting member is a plate-like member that is provided across the base end of the cap and the tip end of the housing and is removable from at least one of the cap and the housing, and the drug solution administration device enters the unlocked state by removing the plate-like member from either the cap or the housing.

20. In the drug solution administration device of claim 2, the distal end of the housing has a first engaging protrusion protruding from the outer wall of the housing, and the proximal end of the cap has a second engaging protrusion protruding from the outer wall of the cap, and when the housing and the cap are connected by the first connecting structure and the second connecting structure, the connecting member is provided straddling the proximal end of the cap and the distal end of the housing, the connecting member is a plate-like member having a first engaging hole with which the first engaging protrusion engages and a second engaging hole with which the second engaging protrusion engages, the first connecting structure is an engaging structure in which the first engaging protrusion engages with the first engaging hole, and the second connecting structure is an engaging structure in which the second engaging protrusion engages with the second engaging hole, A medicinal solution administration device in which, by detaching the connecting member from the housing, the first engaging protrusion disengages from the first engaging hole, thereby releasing the connected state by the first connecting structure, resulting in a first disconnected state; or, by detaching the connecting member from the cap, the second engaging protrusion disengages from the second engaging hole, thereby releasing the connected state by the second connecting structure, resulting in a second disconnected state.

21. A drug solution administration device as described in claim 20, wherein in the unlocked state, the connection state of one of the first connection structure and the second connection structure is released, and the connection state of the other of the first connection structure and the second connection structure is maintained.

22. A medicinal liquid administration device as described in claim 20, wherein in the unlocked state, the connection states of the first connection structure and the second connection structure are both released, resulting in the first disconnected state and the second disconnected state.

23. A medicinal liquid administration device as described in claim 20, wherein the connecting member has a first slit extending between the first engagement hole and the second engagement hole, and the first slit connects the first engagement hole and the second engagement hole.

24. A medicinal liquid administration device as described in claim 23, wherein the connecting member comprises a second slit provided in the opposite direction to the first slit relative to the first engagement hole, and a third slit provided in the opposite direction to the first slit relative to the second engagement hole, wherein the second slit is formed in connection with the first engagement hole, and the third slit is formed in connection with the second engagement hole.

Images