JP2009060982A - Syringe needle cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly safe cartridge type syringe needle capable of inhibiting a needle tip accident, etc. <P>SOLUTION: The syringe needle cartridge 1 comprises a needle holder 5 to hold a piercing syringe needle 11 in the axial direction, a latch ring 4 to hold the needle holder 5 with a latch part 42 reamed outward in the radial direction by the elastic deformation, and a housing 10 to hold the latch ring 4 and the needle holder 5. The needle holder 5 can drive the latch ring 4 to advance to a restriction position when the needle holder 5 is advanced to the housing 10 in the axial direction for the injection behavior, and the needle holder is pulled out in the axial direction from the latch ring 4 restricted at the restriction position when the needle holder is retracted in the axial direction to return to the initial position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a disposable cartridge type injection needle.

  2. Description of the Related Art Conventionally, there are portable injectors for performing injections at home or at work so that the burden on hospital visits of patients who need regular drug administration such as diabetic patients can be reduced. As such a syringe, there is one that employs a disposable cartridge type injection needle so as to prevent infection or the like due to secondary use of the injection needle (for example, see Patent Document 1).

  However, the conventional cartridge type injection needle has the following problems. That is, there is a problem that a needlestick accident may occur when a cartridge-type injection needle is attached to or removed from the syringe body. Furthermore, the used injection needle has a problem that secondary infection may occur due to a needlestick accident or the like.

JP-A-8-66475

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a highly safe cartridge-type injection needle that can suppress a needlestick accident or the like.

The present invention is an injection needle cartridge for use in a cartridge-type syringe including a substantially cylindrical tip portion provided with an outer peripheral screw, the tip surface of the tip portion being formed so as to be pierced with a needle,
A hollow holder provided with an inner peripheral screw for screwing the tip, and a needle holder provided with a holding plate that forms a bottom surface of the holder and holds the injection needle in an axial direction;
The needle holder can be held in a state where the needle holder can be advanced and retracted in the axial direction by gripping the outer peripheral surface of the needle holder by a plurality of latch portions standing from a bottom plate having a protruding hole through which the injection needle protrudes. And when holding the needle holder, the latch portion is configured to expand radially outward by elastic deformation; and
The latch ring and the needle holder are held so that the backward movement of the latch ring is restricted at a restricting position located on the forward side in the axial direction from the initial position and at least the relative rotation of the needle holder at the initial position can be restricted. And a housing
When the needle holder advances in the axial direction with respect to the housing during an injection action, the latch ring can be driven to advance to the restriction position, while being retracted in the axial direction so as to return to the initial position. The injection needle cartridge is configured to be pulled out in an axial direction from the latch ring regulated at the regulation position (Claim 1).

  The injection needle cartridge of the present invention includes the needle holder that penetrates and holds the injection needle, the latch ring that holds the needle holder in a state where the latch portion is elastically deformed so as to expand radially outward, and And the housing for holding the needle holder and the latch ring.

  The latch ring in the product state (unused state) holds the needle holder in a state where it can be advanced and retracted in the axial direction. Then, when the latch ring held by the housing advances in the axial direction from the initial position, the axial retreat is restricted at the restriction position and cannot be returned to the initial position. The needle holder held by the housing is restricted from rotating relative to the housing at least at an initial position.

  In using the injection needle cartridge, the injection needle cartridge can be attached to the cartridge type syringe by screwing the tip portion into the accommodating portion. Here, relative rotation of the needle holder in the initial position with respect to the housing is restricted. Therefore, for example, as long as the housing is held, the cartridge type syringe can be easily screwed.

  If the cartridge type syringe is pushed in the axial direction with respect to the housing, the needle holder can be advanced in the axial direction with respect to the housing. The needle holder first advances in the axial direction relative to the latch ring, and thereafter, the latch ring is driven to advance in the axial direction.

  When the cartridge-type syringe is pulled out from the housing after the injection action is completed, the needle holder into which the tip is screwed can be retracted in the axial direction and returned to the initial position. On the other hand, the latch ring is restricted from being retracted at the restricting position, and cannot be retracted to the initial position together with the needle holder. When the needle holder is retracted to the initial position, the needle holder is pulled out from the latch ring at the restriction position in the axial direction.

  When the needle holder is pulled out, the latch portion elastically deformed radially outward returns to the radially inner periphery, and the inner peripheral shape formed by the latch portion is more than the outer shape of the needle holder. Get smaller. Therefore, in a state where the needle holder is pulled out from the latch ring, the advancement of the needle holder in the protruding direction can be regulated with high certainty by the latch portion that is elastically returned to the radially inner peripheral side.

  According to the injection needle cartridge, by pulling out the cartridge type syringe from the housing as described above, it is possible to automatically set a state in which the cartridge type syringe cannot be advanced in the protruding direction. Therefore, it is possible to prevent a needle stick accident that may occur when the injection needle after the injection is performed again. Further, when the needle holder is pulled out from the latch ring and retracted to the initial position, relative rotation of the needle holder with respect to the housing is restricted. Therefore, the needle cartridge can be removed with high safety by rotating the cartridge type syringe screwed into the housing portion in the reverse direction.

  As described above, the injection needle cartridge of the present invention is a product with excellent safety and high characteristics that can prevent a needle stick accident.

In the injection needle cartridge of the present invention, an outer peripheral convex portion that protrudes toward the outer periphery is formed on the outer peripheral surface of the latch portion in the latch ring, and an inner peripheral convex portion that protrudes toward the inner periphery on the inner peripheral surface of the housing. Is formed,
The latch ring is advanced in the axial direction on the first outer peripheral end surface, which is the end surface on the forward side in the outer peripheral convex portion, and on the second inner peripheral end surface, which is the end surface on the opposite side to the forward side, in the inner peripheral convex portion. It is formed so that a load that elastically deforms the latch portion toward the inner peripheral side according to the contact load when trying to be generated can be generated,
The latch ring is retracted in the axial direction on the second outer peripheral end surface which is the end surface opposite to the advance side in the outer peripheral convex portion and the first inner peripheral end surface which is the end surface on the forward side in the inner peripheral convex portion. It is formed so that a load that elastically deforms the latch portion toward the inner peripheral side according to the contact load when trying to occur cannot be generated.
Preferably, the restriction position is a position where the second outer peripheral end surface and the first inner peripheral end surface are in contact with each other (Claim 2).

  When the latch ring is advanced in the axial direction, the latch portion can be deformed radially inward according to the contact between the first outer peripheral end surface and the second inner peripheral end surface. When the latch portion is elastically deformed radially inward and the outer peripheral convex portion is located on the inner peripheral side of the inner peripheral convex portion, the latch ring is axially extended until the outer peripheral convex portion exceeds the inner peripheral convex portion. You can move forward. After that, even if the latch ring is to be retracted in the axial direction, the latch portion is deformed radially inward at the restricting position where the second outer peripheral end surface abuts on the first inner peripheral end surface. There is nothing. In a state where the outer peripheral convex portion is not positioned on the inner peripheral side of the inner peripheral convex portion, the latch ring cannot be retracted in the axial direction beyond the restriction position.

Further, in the latch ring positioned at the restriction position, it is preferable that elastic deformation of the latch portion that is to be expanded radially outward is restricted by the inner peripheral convex portion that is located on the outer peripheral side of the latch portion. (Claim 3).
In this case, the advance of the needle holder in the axial direction can be regulated with higher certainty by the latch portion of the latch ring regulated at the regulation position.

Moreover, it is preferable that the said latch part in the said latch ring is arrange | positioned at the 3-5 places of the substantially equal intervals in the circumferential direction.
In this case, the needle holder can be held with high reliability according to the three to five latch portions at substantially equal intervals in the circumferential direction.

The housing has an axially divided structure including an end housing and a cap housing, and the needle holder and the latch ring cannot be taken out unless the end housing and the cap housing are separated. Configured,
The end housing and the cap housing are arranged in an axial direction via an elastic latch mechanism that combines an insert part configured to be elastically deformable at least partially and an insertion part for inserting the insert part. It has been retained,
The elastic latch mechanism can be inserted into the insertion portion according to the elastic deformation of the insert portion when the end housing and the cap housing are assembled, and after the assembly, the insert that has been elastically restored. It is preferable that the portion is configured to engage with the insertion portion.

  When the elastic latch mechanism is employed, when the end housing and the cap housing are assembled, insertion into the insertion portion can be facilitated by elastic deformation of the insert portion. Furthermore, according to the elastic latch mechanism configured so that the insert portion elastically restored in the inserted state is engaged with the insertion portion, it is possible to make it difficult to disassemble the end housing and the cap housing. If it is difficult to disassemble the end housing and the cap housing, it is possible to prevent the possibility of a needlestick accident occurring due to disassembly by mischief or the like.

  Further, in the product state, the advancement of the needle holder in the axial direction with respect to the housing is restricted, and the needle holder is advanced in the axial direction by rotating the needle holder by a predetermined amount relative to the housing. It is preferable that the state can be set (claim 6).

In this case, it is possible to suppress the possibility that the injection needle protrudes due to external factors such as vibration during transportation of the injection needle cartridge in a product state, that is, an unused state.
Furthermore, the relative rotation direction for setting the state in which the needle holder can be advanced may be set to the rotation direction when the cartridge type syringe is screwed. In this case, when the cartridge type syringe is mounted, the needle holder can be relatively rotated to set a state in which the needle holder can be advanced in the axial direction.

Moreover, you may provide the stopper for restrict | limiting the advance of the axial direction of the said needle holder with respect to the said housing in a product state (Claim 7).
In this case, by using the stopper, it is possible to prevent with high certainty the possibility that the injection needle protrudes carelessly.

The embodiment of the present invention will be specifically described with reference to the following examples.
(Example 1)
This example is an example of a disposable needle cartridge 1 applied to the cartridge type syringe 6. The contents will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the injection needle cartridge 1 of this example includes a substantially cylindrical tip portion 62 provided with an outer peripheral screw, and a cartridge-type syringe 6 formed so that the tip surface 620 can be inserted into a needle. It is the cartridge of the injection needle to be used.
The injection needle cartridge 1 has a hollow accommodating portion 50 provided with an inner peripheral screw for screwing the distal end portion 62, and a bottom surface of the accommodating portion 50, and the injection needle 11 is held through in the axial direction. By holding the outer peripheral surface of the needle holder 5 with the needle holder 5 having the holding plate 51 and the plurality of latch portions 42 erected from the bottom plate 41 having the protruding holes 410 through which the injection needle 11 protrudes, the shaft A latch ring configured to hold the needle holder 5 in a state in which the needle holder 5 can be advanced and retracted in the direction, and when the needle holder 5 is held, the latch portion 42 expands radially outward by elastic deformation. 4 and the restriction position located on the forward side in the axial direction from the initial position, the backward movement of the latch ring 4 is restricted, and at least the relative rotation of the needle holder 5 at the initial position can be restricted. Has a housing 10 which holds the latch ring 4 and the needle holder 5, the as such.
When the needle holder 5 is moved forward in the axial direction with respect to the housing 10 during the injection action, the latch holder 4 can be driven to advance to the restriction position, while being retracted in the axial direction so as to return to the initial position. At this time, it is configured to be pulled out in the axial direction from the latch ring 4 regulated at the regulation position. Furthermore, the injection needle cartridge 1 in the product state (unused state) is equipped with a stopper 15 for preventing the injection needle 11 from protruding.
Hereinafter, this content will be described in detail.

  First, a cartridge type syringe 6 to which the injection needle cartridge 1 of this example is applied will be described. As shown in FIG. 2, the cartridge type syringe 6 is a pen-type hypodermic syringe generally called a medication pen 6. Such a cartridge-type syringe 6 (hereinafter referred to as a medication pen 6) is a medical instrument for allowing a diabetic patient or the like who needs medication every predetermined time to inject himself / herself.

  As shown in FIG. 2, the medication pen 6 includes a substantially cylindrical shaft body 60 that forms a main body, a medicine cartridge 64 that stores a liquid medicine for several doses, and a push-in operation section for ejecting the medicine. There is provided a push rod 61 and a dose setting mechanism 63 for setting a dose of medicine by one injection in advance.

  As shown in FIGS. 1 and 2, a screw for screwing into the injection needle cartridge 1 is formed on the outer periphery of the distal end portion 62 of the shaft body 60. The distal end surface 620 of the distal end portion 62 is formed of a rubber diaphragm (not shown) that can be punctured and resealed. A push rod 61 is inserted into the rear end of the shaft body 60 that forms the open end. The medication pen 6 can inject a predetermined amount of medicine by an axial pushing operation on the push rod 61.

  The medicine cartridge 64 is a substantially cylindrical container inserted into the shaft body 60. The opening end on the distal end side of the medicine cartridge 64 is configured to be pressed against the diaphragm in a liquid-tight state. A plunger (not shown) is inserted into the opening end of the medicine cartridge 64 on the push rod 61 side so as to be movable back and forth and in a liquid-tight state. The plunger makes a forward stroke toward the distal end side of the shaft body 60 in accordance with the pushing operation of the push rod 61.

  The dose setting mechanism 63 is a mechanism for setting the advance stroke amount of the plunger accompanying the push-in operation of the push rod 61 in advance. This dose setting mechanism 63 includes a through window 632 drilled in the outer peripheral portion on the rear end side of the shaft body 60, and a thin and substantially cylindrical dial sleeve 631 disposed in the gap between the drug cartridge 64 and the shaft body 60. A combination of

  In the dose setting mechanism 63, a reference line 633 is printed on the outer peripheral surface of the shaft body 60, and numbers and scales indicating doses such as 0, 1, 2, and the like are printed on the outer periphery of the dial sleeve 631. . The numbers and scales of the dial sleeve 631 are visible through the through window 632 of the shaft body 60. In the dose setting mechanism 63, by rotating the dial sleeve 631, the numbers and scales positioned on the reference line 633 can be changed, whereby the dose of the medicine per time can be set.

  Next, the injection needle cartridge 1 will be described with reference to FIGS. As described above with reference to FIG. 1, the injection needle cartridge 1 includes a latch ring 4 that prevents re-projection of the used injection needle 11, a needle holder 5 that penetrates and holds the injection needle 11, the latch ring 4, and the needle And a housing 10 that holds the holder 5 in an axially advanceable state. Further, in the syringe cartridge 1 in the product state (unused state), the advancement of the needle holder 5 is restricted by the stopper 15 attached to the distal end side (advance side) of the housing 10. In the product state, the entire injection needle cartridge 1 with the stopper 15 attached is preferably covered with a resin film (not shown). If the whole is covered with the resin film, the sterilized state of the injection needle 11 can be maintained with high reliability. As the resin film, various materials such as polypropylene, polyethylene, polyvinylidene chloride, and polyethylene terephthalate can be adopted.

As shown in FIGS. 1 to 4, the housing 10 has a two-part structure including a cap housing 2 positioned on the front end side (advance side) and an end housing 3 positioned on the rear end side.
As shown in FIG. 3, the end housing 3 is a substantially cylindrical member made of polypropylene. An insert portion 31 to be inserted into the cap housing 2 is formed at the distal end portion of the end housing 3 located on the cap housing 2 side.

  The insert portion 31 is inserted with a taper-shaped engagement portion 312 that gradually increases in diameter from the tip, and a substantially constant outer diameter that is connected to the engagement portion 312 by reducing the diameter via an end surface 313 that is substantially orthogonal to the axial direction. Part 311. Further, in the insert portion 31, slits 310 along the axial direction are formed every 90 degrees in the circumferential direction so that the diameter of the engaging portion 312 can be easily reduced by elastic deformation. The insert portion 31 forms the elastic latch mechanism 12 together with the insertion portion 21 of the cap housing 2 described later.

  An inner peripheral spline 32 is formed on the inner peripheral surface of the end housing 3 on the rear end side (on the medication pen 6 side), with crests and valleys formed along the axial direction arranged at equal intervals in the circumferential direction. . According to the inner peripheral spline 32, the rotation of the needle holder 5 at the initial position can be restricted by engagement with an outer peripheral spline 52 of the needle holder 5 described later.

  As shown in FIGS. 1, 2, and 4, the cap housing 2 is a member having a substantially cylindrical shape made of polypropylene. The bottom plate 25 that forms the bottom surface of the cap housing 2 is provided with a projecting hole 250 for projecting the injection needle 11. Inside the cap housing 2, an insertion portion 21 in which the insert portion 31 is inserted and arranged in an axial direction from the end housing 3 side, and a ring insertion portion 22 in which the latch ring 4 is inserted are formed. Yes.

  The insertion portion 21 constitutes the elastic latch mechanism 12 together with the insert portion 31 of the end housing 3. The insertion portion 21 includes an insertion portion 211 having a substantially constant inner diameter in which the insertion portion 311 of the insert portion 31 is inserted and disposed, and a diameter of the insertion portion 21 that extends from the insertion portion 21 through an end surface 213 substantially orthogonal to the axial direction. The engaging portion 212 is included. The engaged portion 212 is a portion where the engaging portion 312 is disposed. The end housing 3 inserted into the cap housing 2 is reliably prevented from coming off by facing the end surface 213 of the engaged portion 212 and the end surface 313 of the engaging portion 312.

  In the injection needle cartridge 1 of this example, disassembly such as pulling out the end housing 3 from the cap housing 2 is difficult by the elastic latch mechanism 12 formed by a combination of the insert portion 31 and the insertion portion 21. In the injection needle cartridge 1, there is very little possibility that the needle holder 5 is taken out by being disassembled by a child's mischief or the like. Since the removal of the needle holder 5 can be directly connected to a needlestick accident, the elastic latch mechanism 12 as described above is very effective.

  The ring insertion part 22 has a substantially constant inner diameter except for the inner peripheral convex part 220 provided at one axial position so as to protrude toward the inner peripheral side. The inner circumferential convex portion 220 is formed over the entire circumference of the inner circumferential surface. The first inner peripheral end surface 221 which is an end surface located on the bottom plate 25 side (the advance side of the latch ring 4) in the inner peripheral convex portion 220 is formed by a surface substantially orthogonal to the axial direction, and is an end surface on the opening side positioned on the opposite side. The second inner peripheral end face 222 is a tapered surface that gradually decreases in diameter toward the forward side.

  As shown in FIGS. 1, 2, and 5, the latch ring 4 is a member made of polypropylene. The latch ring 4 has a substantially annular bottom plate 41 provided with a projecting hole 410 for projecting the injection needle 11 and a latch portion 42 erected from the bottom plate 41 at four positions at substantially equal intervals in the circumferential direction. is doing. The latch part 42 has a substantially constant cross-sectional arc shape (not shown) except for the outer peripheral convex part 420 provided at one place in the axial direction. Each latch portion 42 in the natural state is gradually curved toward the radially inner side as it approaches the tip. Therefore, in the natural state, the diameter of the latch ring 4 formed by the four latch portions 42 is gradually reduced as it approaches the tip.

  As shown in FIG. 5, the outer peripheral convex portion 420 provided on the latch portion 42 is a portion protruding from the outer peripheral surface of each latch portion 42 at an intermediate position in the axial direction. The outer peripheral convex part 420 of each latch part 42 is arrange | positioned on the circumference orthogonal to an axial direction. A first outer peripheral end surface 421 that is an end surface on the bottom plate 41 side (the forward side of the latch ring 4) in the outer peripheral convex portion 420 is formed by a tapered surface that gradually decreases in diameter toward the forward side, and is located on the opposite side. The outer peripheral end surface 422 of 2 is formed by a surface substantially orthogonal to the axial direction. The outer diameter formed by the outer peripheral convex portion 420 of each latch portion 42 is substantially the same as the inner diameter of the ring insertion portion 22 of the cap housing 2 (the inner diameter of the portion excluding the inner peripheral convex portion 220).

  As shown in FIGS. 1, 2, and 6, the needle holder 5 is a member having a substantially cylindrical shape made of polypropylene. The needle holder 5 holds the injection needle 11 through a holding plate 51 forming a bottom portion. The inner peripheral portion of the needle holder 5 forms an accommodating portion 50 for screwing the distal end portion 62 of the medication pen 6. An inner peripheral screw for screwing the distal end portion 62 is formed on the inner peripheral surface forming the accommodating portion 50.

  On the outer periphery of the needle holder 5, as shown in FIG. 6, an outer peripheral spline 52 in which peaks and valleys along the axial direction are provided at substantially equal intervals in the axial direction in order from the medication pen 6 side (rear end side) in the axial direction. A retaining portion 53 having a diameter larger than at least the inner diameter of the inner peripheral spline 32, a large diameter flange portion 54 that slides while circumscribing the inner peripheral surface of the latch portion 42, and a protrusion hole 410 of the latch ring 4 or the cap housing 2. , 250 is formed. According to the outer peripheral spline 52, the relative rotation of the needle holder 5 can be restricted by the engagement with the inner peripheral spline 32 of the end housing 3 described above.

  As shown in FIGS. 1 and 7, the stopper 15 is a substantially U-shaped member made of polypropylene. A bottom plate 151 forming a substantially U-shaped bottom portion has a through hole 150 for allowing the injection needle 11 to pass therethrough. The pair of elastic pieces 152 erected from the bottom plate 151 includes a wide engaging portion 153 that protrudes in a direction orthogonal to the erection direction. The engaging portion 153 is formed by an inclined surface 154 that is inclined so as to gradually become wider toward the distal end side of the elastic piece 152, and an end surface 155 that is substantially orthogonal to the standing direction. According to the stopper 15, the bottom plate 151 comes into contact with the distal end surface of the needle holder 5 when the end surface 155 is attached to the bottom plate 25 of the cap housing 2.

  In the injection needle cartridge 1 to which the stopper 15 is attached, as shown in FIGS. 1 and 7, the advancement of the needle holder 5 inside the housing 10 is highly reliably regulated by the bottom plate 151 that abuts on the distal end surface of the needle holder 5. Is done. Further, the forward movement of the latch ring 4 inside the housing 10 is highly reliably restricted by the inclined surface 154 (engagement portion 153) that engages with the holding plate 41 of the latch ring 4.

  The injection needle cartridge 1 of this example is a combination of the components configured as described above. In the injection needle cartridge 1 with the stopper 15 removed, the housing 10 in a state where the insert portion 31 of the end housing 3 is inserted and fixed to the insertion portion 21 of the cap housing 2 as shown in FIGS. 1 and 3 to 6. The latch ring 4 and the needle holder 5 can advance in the axial direction. The assembled state (product state) and operation of the injection needle cartridge of this example will be described with reference to FIG. In FIG. 8, the medication pen 6 is not shown.

  In FIG. 8, as in Step 1, in the injection needle cartridge 1 in the product state (unused state), inside the housing 10 in a state where the insert portion 31 of the end housing 3 is inserted into the insertion portion 21 of the cap housing 2, The outer peripheral spline 52 of the needle holder 5 is engaged with the inner peripheral spline 32 of the end housing 3, and the second inner peripheral end face 222 of the inner peripheral convex portion 220 of the cap housing 2 and the outer peripheral convex portion 420 of the latch ring 4 are It is in the initial state where the first outer peripheral end surface 421 faces. The axial positions of the needle holder 5 and the latch ring 4 in this initial state are the initial positions.

  In the initial state where the relative rotation of the needle holder 5 is restricted by the engagement between the outer peripheral spline 52 and the inner peripheral spline 32 as described above, the distal end portion 62 of the medication pen 6 (see FIG. 2) is moved with respect to the needle holder 5. It can be easily screwed in. In addition, when screwing the medication pen 6, it is preferable to proceed with the stopper 15 (see FIGS. 1 and 7) installed so that the injection needle 11 can be prevented from being accidentally protruded. Further, in this initial state, the collar portion 54 of the needle holder 5 is inserted in the distal end side of the latch portion 42 of the latch ring 4. In the state where the collar portion 54 is inserted, elastic deformation occurs so that each latch portion 42 expands radially outward.

  After the stopper 15 is removed, when the medication pen 6 screwed into the needle holder 5 is pushed out in the axial direction, the needle holder 5 is first moved in the axial direction on the inner peripheral side of the latch ring 4 as shown in step 2 in FIG. The protrusion 55 of the needle holder 5 can be protruded from the protrusion hole 410 of the latch ring 4 by being advanced. Further, when the medication pen 6 is pushed in, a contact load can be applied between the second inner peripheral end surface 222 and the first outer peripheral end surface 421. In the contact structure between the second inner peripheral end surface 222 and the first outer peripheral end surface 421 which are tapered surfaces, an axial contact load can be converted into a radial load. The radial load can act in the direction of expanding the cap housing 2 and in the direction of deforming the latch portion 42 of the latch ring 4 to the inner peripheral side.

  Here, the cap housing 2 is formed with sufficiently high rigidity as compared with the latch portion 42. Therefore, according to the load in the radial direction, the latch portion 42 is elastically deformed toward the inner peripheral side, and the outer diameter of the outer peripheral convex portion 420 can be reduced. If the outer diameter of the outer peripheral convex portion 420 is smaller than the inner diameter of the inner peripheral convex portion 220, the outer peripheral convex portion 420 can move over the inner peripheral convex portion 220 and advance in the axial direction, and the injection needle 11 protrudes as in step 3 in FIG. Will be ready for injection.

  When the medication pen 6 is pulled out from the injection needle cartridge 1 after completion of the injection action, the second outer peripheral end surface 422 of the outer peripheral convex portion 420 and the first inner peripheral end surface of the inner peripheral convex portion 220 as shown in Step 4 in FIG. Retraction of the latch ring 4 is restricted at a restricting position where it abuts against 222. On the other hand, the needle holder 5 slides on the inner peripheral side of the latch ring 4 and can be retracted to the initial position. Here, the retaining portion 53 is formed larger in diameter than the inner diameter of the inner peripheral spline 32. Therefore, as in step 5 in FIG. 8, the needle holder 5 does not fall off in the axial direction beyond the initial position where the inner peripheral spline 32 and the outer peripheral spline 52 are engaged.

  As described above, when the needle holder 5 is retracted to the initial position with respect to the latch ring 4 at the restriction position, the needle holder 5 is pulled out from the latch ring 4 in the axial direction. Then, the latch portion 42 that has expanded in the radial direction due to elastic deformation is elastically restored to the inner peripheral side. The inner diameter formed by the tips of the four latch portions 42 is smaller than the collar portion 54 of the needle holder 5. After shifting to this state, even if it tries to push the medication pen 6 into the housing 10 again, each latch part 42 acts like a tension and the advance of the needle holder 5 can be regulated with high rigidity. That is, in the injection needle cartridge 1 of the present example, there is little possibility that the injection needle 11 protrudes again after shifting to step 4 in FIG. 8, and a needle stick accident or the like can be prevented in advance.

  Further, in the injection needle cartridge 1 of the present example, the end housing 3 and the cap housing 2 are fixed via a latch mechanism 12 that is a combination of an insert portion 31 and an insertion portion 21 that are elastically deformable. Therefore, there is very little possibility that the end housing 3 and the cap housing 2 are disassembled due to a child's mischief or the like. In the injection needle cartridge 1 of this example, the needle holder 5 cannot be taken out unless the housing 10 is destroyed. According to the injection needle cartridge 1 of the present example, the possibility that a needlestick accident may occur due to the needle holder 5 taken out to the outside can be suppressed in advance.

  As described above, in the injection needle cartridge 1 of the present example, the advancement of the needle holder 5 can be regulated with high reliability by the latch ring 4 regulated at the regulation position after use. Therefore, the injection needle cartridge 1 is an excellent product with high safety because there is little possibility that the injection needle 11 protrudes carelessly.

  The material of the housing 10 (the end housing 3 and the cap housing 2), the needle holder 5, the latch ring 4, and the stopper 15 is not limited to the polypropylene of this example. In addition to the polypropylene of this example, various materials such as polyethylene, polyvinylidene chloride, and polyethylene terephthalate can be employed.

(Example 2)
In this example, the stopper is omitted based on the injection needle cartridge of the first embodiment. This will be described with reference to FIG.
In the injection needle cartridge of the present example, the engagement structure of the inner peripheral spline 32 of the end housing 3 and the outer peripheral spline 52 of the needle holder 5 is used to suppress the possibility that the injection needle protrudes carelessly. FIG. 9 is a diagram showing the engagement structure of the inner peripheral spline 32 and the outer peripheral spline 52 developed on a plane.

  In the inner circumferential spline 32 of the end housing 3 of this example, the circumferential formation width M3 of the peaks 321 is approximately ½ of the circumferential formation width V3 of the valleys 322. In the outer peripheral spline 52 of the needle holder 5, the formation width M5 in the circumferential direction of the peak 521 is approximately ½ of the formation width V5 in the circumferential direction of the valley 522. The valley 522 of the outer peripheral spline 52 is wider than the peak 321 of the inner peripheral spline 32, and the valley 322 of the inner peripheral spline 32 is wider than the peak 521 of the outer peripheral spline 52. Therefore, even when the inner peripheral spline 32 and the outer peripheral spline 52 are engaged, the end housing 3 and the needle holder 5 can be relatively rotated in a predetermined circumferential range.

  Furthermore, in each valley 322 of the inner peripheral spline 32 of this example, a convex rib 328 extending in the circumferential direction is formed. Each rib 328 is located at an end portion on the axial advance side, and in a range of approximately half of the formation range of the valley 322 in the circumferential direction adjacent to the right rotation side (lower side in the figure) of the mountain 321. It is formed across. In the product state shown in FIG. 9, the forward movement in the axial direction of the peak 521 of the outer peripheral spline 52 is restricted by the presence of the rib 328.

  By rotating the outer peripheral spline 52 relative to the inner peripheral spline 32 in the right direction and shifting the position of the peak 521 in the valley 322 downward in the figure, the peak 521 can advance in the axial direction. That is, by rotating the outer peripheral spline 52 in the clockwise direction when the medication pen is screwed into the injection needle cartridge, the crest 521 is shifted downward in FIG. 9, and the rib 328 is avoided to advance in the axial direction. It becomes possible.

  In the injection needle cartridge of this example, in the product state, the advancement of the peak 521 in the axial direction is inhibited by the rib 328, whereby the protrusion of the injection needle due to the advancement of the needle holder 5 is restricted. This state is the same as the state in which the stopper in the injection needle cartridge of Example 1 is mounted. When the medication pen is rotated in the right direction and screwed in, the needle holder 5 can be set in a state in which the needle holder 5 can advance in the axial direction by rotating the outer peripheral spline 52 relative to the inner peripheral spline 32. This state is a state in which the stopper in the injection needle cartridge of Example 1 is removed.

  After completion of the injection action, the medication pen is pulled out in the axial direction, the needle holder 5 is returned to the initial position, and then the medication pen is rotated in the counterclockwise direction opposite to the screwed direction to rotate the medication pen from the medication pen to the injection needle. Remove the cartridge. At this time, the outer peripheral spline 52 can be rotated relative to the inner peripheral spline 32 in the counterclockwise direction, and the state where the forward movement of the mountain 521 is inhibited by the rib 328 (the state shown in FIG. 9) can be reset. This state is a state in which the protrusion of the injection needle due to the advancement of the needle holder 5 is restricted, similar to the state where the stopper in the injection needle cartridge of Example 1 is mounted.

As described above, according to the injection needle cartridge of the present example, it is possible to prevent an inadvertent protrusion of the injection needle irrespective of the stopper.
Other configurations and operational effects are the same as those in the first embodiment.

Sectional drawing which shows the structure of the injection needle cartridge in Example 1. FIG. FIG. 3 is a side view showing a medication pen equipped with an injection needle cartridge according to the first embodiment. Sectional drawing which shows the structure of an end housing in Example 1. FIG. Sectional drawing which shows the structure of the cap housing in Example 1. FIG. Sectional drawing which shows the structure of the latch ring in Example 1. FIG. Sectional drawing which shows the structure of the needle holder in Example 1. FIG. The side view which shows the stopper in Example 1. FIG. FIG. 3 is an operation diagram illustrating the operation of the injection needle cartridge according to the first embodiment. The expanded view which expands and shows the engagement structure of the outer periphery spline and inner periphery spline in Example 2 in Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection needle cartridge 10 Housing 11 Injection needle 15 Stopper 2 Cap housing 220 Inner peripheral convex part 221 1st internal peripheral end surface 222 2nd internal peripheral end surface 3 End housing 32 Inner peripheral spline 4 Latch ring 41 Bottom plate 42 Latch part 420 Outer peripheral convex part 421 First outer peripheral end surface 422 Second outer peripheral end surface 5 Needle holder 52 Outer peripheral spline 6 Cartridge type syringe (medication pen)
60 Shaft body 620 Tip surface 63 Dose setting mechanism 64 Drug cartridge

Claims (7)

An injection needle cartridge for use in a cartridge type syringe including a substantially cylindrical tip portion provided with an outer peripheral screw, the tip surface of the tip portion being formed so as to be pierced by a needle,
A hollow holder provided with an inner peripheral screw for screwing the tip, and a needle holder provided with a holding plate that forms a bottom surface of the holder and holds the injection needle in an axial direction;
The needle holder can be held in a state where the needle holder can be advanced and retracted in the axial direction by gripping the outer peripheral surface of the needle holder by a plurality of latch portions standing from a bottom plate having a protruding hole through which the injection needle protrudes. And when holding the needle holder, the latch portion is configured to expand radially outward by elastic deformation; and
The latch ring and the needle holder are held so that the backward movement of the latch ring is restricted at a restricting position located on the forward side in the axial direction from the initial position and at least the relative rotation of the needle holder at the initial position can be restricted. And a housing
When the needle holder advances in the axial direction with respect to the housing during an injection action, the latch ring can be driven to advance to the restriction position, while being retracted in the axial direction so as to return to the initial position. An injection needle cartridge configured to be pulled out in an axial direction from the latch ring regulated at the regulation position. In Claim 1, the outer peripheral convex part which protrudes toward an outer periphery is formed in the outer peripheral surface of the said latch part in the said latch ring, The inner peripheral convex part which protrudes toward an inner periphery is formed in the inner peripheral surface of the said housing. And
The latch ring is advanced in the axial direction on the first outer peripheral end surface, which is the end surface on the forward side in the outer peripheral convex portion, and on the second inner peripheral end surface, which is the end surface on the opposite side to the forward side, in the inner peripheral convex portion. It is formed so that a load that elastically deforms the latch portion toward the inner peripheral side according to the contact load when trying to be generated can be generated,
The latch ring is retracted in the axial direction on the second outer peripheral end surface which is the end surface opposite to the advance side in the outer peripheral convex portion and the first inner peripheral end surface which is the end surface on the forward side in the inner peripheral convex portion. It is formed so that a load that elastically deforms the latch portion toward the inner peripheral side according to the contact load when trying to occur cannot be generated.
The injection needle cartridge according to claim 1, wherein the restriction position is a position where the second outer peripheral end surface and the first inner peripheral end surface are in contact with each other.   3. The latch ring positioned at the restricting position according to claim 2, wherein elastic deformation of the latch portion that attempts to expand radially outward is restricted by the inner peripheral convex portion located on the outer peripheral side of the latch portion. A needle cartridge characterized by that.   The injection needle cartridge according to any one of claims 1 to 3, wherein the latch portions of the latch ring are disposed at approximately three to five positions at substantially equal intervals in the circumferential direction. 5. The housing according to claim 1, wherein the housing has an axially divided structure including an end housing and a cap housing, and the needle holder and the cap housing are not separated from each other unless the end housing and the cap housing are separated from each other. The latch ring is configured so that it cannot be removed,
The end housing and the cap housing are arranged in an axial direction via an elastic latch mechanism that combines an insert part configured to be elastically deformable at least partially and an insertion part for inserting the insert part. It has been retained,
The elastic latch mechanism can be inserted into the insertion portion according to the elastic deformation of the insert portion when the end housing and the cap housing are assembled, and after the assembly, the insert that has been elastically restored. An injection needle cartridge, wherein the portion is configured to engage with the insertion portion.   6. The product according to claim 1, wherein in the product state, the advance of the needle holder in the axial direction relative to the housing is restricted, and the needle holder is rotated relative to the housing by a predetermined amount. Thus, the injection needle cartridge is configured so that a state in which the needle holder can be advanced in the axial direction can be set.   6. The injection needle cartridge according to claim 1, further comprising a stopper for restricting the advancement of the needle holder in the axial direction relative to the housing in a product state.

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