JPH08135B2 - Syringe, piston used in the syringe, and closing member for the syringe - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a syringe suitable for disposable use.

[0002]

2. Description of the Related Art FIG. 6 is a schematic diagram showing a positional relationship between a syringe and a piston in an example of a conventionally proposed disposable injector. Conventionally, in disposable syringes, by inserting the injection needle immediately after use into a syringe that cannot be touched directly by the hands, etc., the hands, etc. are injured by the injection needle to which the patient's blood, etc. adheres and secondary infection occurs. There has been proposed a syringe having a function of accommodating an injection needle, which can prevent such an accident. In a conventionally proposed disposable syringe having a needle storing function, the needle storing operation is performed by operating a piston to engage the piston with a hub to which the needle is joined, and further by the piston. , The engaged hub is pulled into the syringe together with the injection needle. Further, as shown in FIG. 6, the engagement between the hub and the piston is provided on the end side of the hub 40 on the piston side by further pressing the piston 42 at the injection end position P1 toward the hub 40 side. The hub engagement portion 43 provided at the tip of the piston 42 is press-fitted into the piston engagement hole 41. The end surface 45a side of the packing 45 provided on the piston 42 is aligned with the inner surface 46a side of the syringe 46 at the injection end position P1, and therefore, the piston 4 at the injection end position P1.
By further pressing 2 toward the hub 40 side, substantially the entire packing 45 is axially compressed.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Since a relatively large force is required to axially compress substantially the whole of the above, a large force is required to engage the piston 42 and the hub 40. Therefore, the operability in the needle accommodating operation is poor. The present invention has been made in view of the above circumstances, and an object thereof is to provide a syringe capable of engaging a piston and a hub with a force that is as small as possible in the disposable syringe, thereby allowing the needle accommodating operation to be performed easily.

[0004]

That is, the first invention of the present invention has a cylindrical syringe (100) having a liquid holding space (53) formed therein, and the syringe (100)
A hub (9) is detachably inserted into the hub (9), and an injection needle (21) is joined to the side of the hub (9) facing away from the liquid holding space (53). A hub side engaging means (15) is provided on a side of the syringe facing the liquid holding space (53), and the piston body (25) is attached to the syringe (100).
Is provided inside the syringe (100), the piston body (25) is provided with a piston side engaging means (31), and the hub (9) is provided with a hub side engaging means (15).
A closing member (33) formed of an elastic material on the piston body (25) so as to be inserted into and engageable with the hub side engaging means (15) so as to face the closing member (33). ) Closes the inside of the syringe (100) in the axial direction (directions of arrows A and B), and the syringe (1
00) along with the piston body (25) so as to be movable in the axial direction (arrows A and B directions), and a deformation promoting space (35f) is formed inside the closing member (33). . The second invention of the present invention is the syringe (1) according to the first invention, wherein the deformation promoting space (35) is provided.
f) was made hollow. A third aspect of the present invention is the syringe (1) of the first aspect of the present invention, wherein the deformation promoting space (35f) is filled with a soft material that is softer than the closing member. A fourth invention of the present invention is the piston (23) used in the syringe (1) of the first invention, wherein the piston (23) has a piston body (25). ) Is provided with a piston side engaging means (31) so as to be insertably engaged with the hub side engaging means (15), and a closing member (made of an elastic material is formed on the piston body (25) ( Three
3), the closing member (33) is the syringe (100)
Can be closed in the axial direction (directions of arrows A and B) and is provided so as to be movable in the axial direction (directions of arrows A and B) together with the piston body (25) with respect to the syringe (100), A hollow deformation promoting space (35f) was formed inside the closing member (33). A fifth aspect of the present invention is configured such that, in the piston (23) of the fourth aspect, the deformation promoting space (35f) is hollow. The sixth invention of the present invention is the piston (23) of the fourth invention, wherein the deformation promoting space (35f) is provided.
And a soft material softer than the closing member. The seventh invention of the present invention has a main body (35) made of an elastic material, and forms a sliding surface (35g) against the syringe around the main body (35),
A liquid pressing surface (35e) is formed at one end of the main body (3
5) A supporting surface (35h) is formed on the other end of the main body (3).
5), a piston engagement insertion space (35a) is provided, and a deformation promoting space (35f) is formed between the piston engagement insertion space (35a) and the syringe sliding surface (35g). did. The eighth aspect of the present invention is configured such that the deformation promoting space (35f) is hollow in the closing member (33) of the seventh aspect. The ninth invention of the present invention is configured such that, in the closing member (33) of the seventh invention, the deformation promoting space (35f) is filled with a soft material softer than the main body. The numbers in parentheses () indicate the corresponding elements in the drawings for convenience, and therefore the present description is not limited to the description in the drawings. The same applies to the following action columns.

[0005]

With the above structure, the first, fourth, and fourth aspects of the present invention are provided.
In the seventh invention, the deformation promoting space (35f) inside the closing member (33) is compressed with a smaller force than the compression of the elastic material. In the second, fifth, and eighth aspects of the present invention, the air in the deformation promoting space (35f) is compressed together with the compression of the closing member (33). In the third, sixth and ninth aspects of the present invention, the soft material filled in the deformation promoting space (35f) is compressed together with the compression of the closing member (33).

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing the vicinity of the hub and the tip of a piston in an example of the injector according to the present invention, FIG. 2 is a schematic sectional view showing the entire injector shown in FIG. 1, and FIG. Two
5 is a view of the vicinity of the hub insertion part of the syringe shown in FIG. 4, FIG. 4 is a view of the hub insertion part of the syringe shown in FIG.
It is the figure which showed the breaking operation of the piston in the injector shown in FIG.

The syringe 1 according to the present invention has a resin syringe 100 as shown in FIG.
00 is provided with a syringe body 2 (note that FIG. 2 is a schematic cross-sectional view of the syringe 1, but for convenience, a part of a piston 23, which will be described later, shows a side surface rather than a cross-section). . Further, the syringe body 2 is provided with a main cylindrical portion 3 formed in a cylindrical shape. Here, the axial direction of the main cylindrical portion 3, that is, both the forward and reverse directions parallel to the axial center Q1, are the direction of arrow A in the figure (that is, the left direction on the paper surface of FIG. 2) and the direction of the arrow B (the right direction on the paper surface of FIG. 2). ). On the outer peripheral side of the main cylindrical portion 3, a syringe support portion 5 is provided near the opening end 3a of the main cylindrical portion 3 on the arrow B side (the right side in the drawing of FIG. 2).
Is provided in a brim shape on the inner peripheral surface 3c side of the main cylindrical portion 3, in the vicinity of the opening end 3a, toward the axis Q1 of the main cylindrical portion 3, that is, in the direction of arrow D in the figure. A locking rib 3b protruding in the shape of a ring is formed in an annular shape along the inner peripheral surface 3c. On the arrow A side of the main cylindrical portion 3 (on the left side of the paper surface of FIG. 2), the inner diameter has a predetermined ratio K1 toward the arrow A direction.
A funnel-shaped taper portion 6 reduced in size is formed so as to be integrally continuous with the main cylindrical portion 3. The main cylindrical portion 3
And the inside of the tapered portion 6 communicate with each other in the directions of arrows A and B, and the space obtained by combining these insides is defined as an internal space 2a of the syringe body 2.

On the arrow A side of the tapered portion 6, that is, on the distal end side of the syringe body 2, a hub insertion portion 4 is integrally formed with the tapered portion 6 as shown in FIGS. 1 and 2. The hub insertion portion 4 has a small cylindrical portion 7. The small cylindrical portion 7 is formed so as to be integrally continuous with the tapered portion 6 and is formed concentrically with the main cylindrical portion 3. The inner diameter of the small cylindrical portion 7 is the same as that of the main cylindrical portion 3. It is formed smaller than the inner diameter. The inner peripheral surface 7a side of the small cylindrical portion 7 is
The hub insertion hole 4b is formed, and the hub insertion hole 4b is formed with a hub stop rib 7d protruding toward the axis Q1. The hub stop rib 7d is formed in an annular shape along the inner peripheral surface 7a of the small cylindrical portion 7, and is a cross section of the hub stop rib 7d taken along a plane including the axis Q1 (that is, the cross section shown in FIG. 1). Has an arc shape. On the other hand, a reinforcing rib 7c is provided on the outer peripheral surface 7f side of the small cylinder portion 7
It is annularly provided at a position corresponding to the hub stop rib 7d. In addition, as shown in FIGS. 2 to 4, the small cylindrical portion 7 is provided with a disk-shaped end wall 8 having an outer diameter equal to the outer diameter of the small cylindrical portion 7. Wall 8
A wall surface 8b of the end wall 8 on the arrow B side and an arrow A of the small cylindrical portion 7
The side end portion 7b is in contact with each other and is integrally provided with the small cylindrical portion 7. The end wall 8 has a hole 8a having a circular cross section that penetrates both the front and back wall surfaces of the end wall 8 in the directions of arrows A and B.
Is provided around the axis Q1 and the hole 8a
The arrow A side of is formed in a taper shape whose cross-sectional inner diameter increases in the direction of arrow A. Further, three slits 50 are formed over the end wall 8 and the small cylindrical portion 7 as shown in FIGS. 3 and 4. In the end wall 8, the slit 50 is in the radial direction with respect to the axis Q1, that is, the arrows C and D in the figure.
Direction (however, the arrow C direction is the opposite direction of the arrow D direction) and is formed so as to communicate with the hole 8a provided in the end wall 8, and in the small cylindrical portion 7, the arrow It is formed in a shape parallel to the A and B directions. In addition, the slit 50 includes the hub stop rib 7d and the reinforcing rib 7
At a position on the arrow A side of c, the hub stop rib 7d and
It is formed so as not to reach the reinforcing rib 7c.
Since these slits 50 divide the hub insertion portion 4 on the arrow A side into three parts, the hub insertion portion 4 is likely to elastically expand in the arrow C direction at the portion where the slits 50 are formed. There is. That is, when assembling the syringe 1 by inserting the hub 9 described below into the syringe 100, the portion of the hub inserting portion 4 in which the slit 50 is formed is elastically expanded in the direction of the arrow C, and the hole of the end wall 8 is formed. It is possible to enlarge 8a and insert a hub 9 described later into the hub insertion hole 4b through the hole 8a. The hub insertion portion 4 is configured as described above, and in the syringe 100, the syringe support portion 5, the main cylindrical portion 3 forming the syringe body 2, the taper portion 6, and the hub insertion portion 4 are integrally molded. It is configured in a form.

The hub insertion hole 4b of the hub insertion portion 4 is provided with a hub 9 made of resin and harder than the syringe 100. As shown in FIGS. 1 to 3, the hub 9 has a hub main body 90, and the longitudinal direction of the hub main body 90 is parallel to the directions of the arrows A and B, and the axis Q1 is set as the axis. A cylindrical main column portion 10 is provided. Further, a hub stop groove 10c is formed on the outer peripheral surface 10f side of the main cylindrical portion 10, and the hub stop groove 10c is formed in an annular shape along the outer peripheral side of the main cylindrical portion 10. On the side of the end surface 10a on the arrow A side of the main cylindrical portion 10, a small cylindrical portion 11 extending in the directions of arrows A and B is provided concentrically with the main cylindrical portion 10 and integrally with the main cylindrical portion 10. The hub 9 has a main cylindrical portion 10 of the hub 9.
Is inserted into the hub insertion hole 4b of the hub insertion portion 4, and the small cylindrical portion 11 of the hub 9 is inserted through the hole 8a of the end wall 8 to be provided. Further, the hub stop rib 7d of the hub insertion portion 4 and the hub stop groove 10c of the hub 9 are present at positions corresponding to each other, and therefore, the hub stop rib 7d has its tip end on the arrow D side. , The hub stop groove 1 is inserted into the hub stop groove 10c at a position corresponding to the hub stop rib 7d.
0c is engaged. The hub stop rib 7d has an arrow A,
Since the width in the B direction is wider than the widths of the hub stop groove 10c in the arrow A and B directions, the hub stop rib 7d has a hub stop groove at the tip end of the seal portions 7e, 7e on the arrow A side and the arrow B side. The hub stop groove 10c is engaged with the opening end portions 10e and 10e on both sides of arrows A and B of 10c. The inner peripheral surface 7a of the small cylindrical portion 7 is not in contact with the outer peripheral surface 10f of the hub 9 except for the hub stop rib 7d, and a gap space 49 is formed between the inner peripheral surface 7a and the outer peripheral surface 10f. Has been formed. That is, since the contact between the inner peripheral surface 7a side of the hub insertion portion 4b and the hub 9 is performed only between the hub stop rib 7d and the outer peripheral surface 10f side of the hub 9, the hub 9 is attached to the syringe 100. When inserting and assembling the syringe 1, the hub 9 can be easily inserted into the hub insertion portion 4, and the hub 9 is pulled out from the hub insertion portion 4 at the time of an injection needle storing operation described later. (However, if the insertion of the hub 9 into the hub insertion portion 4 and the withdrawal of the hub 9 from the hub insertion portion 4 are easily performed, the inner peripheral surface of the small cylindrical portion 7 A portion of 7a other than the hub stop rib 7d may be in contact with the outer peripheral surface 10f of the hub 9.). Further, the end surface 10b of the main cylindrical portion 10 of the hub 9 on the arrow B side is a boundary between the hub insertion hole 4b and the internal space 2a (that is, a boundary between the inside of the small cylindrical portion 7 and the inside of the tapered portion 6). Is located closer to the arrow A side than that, and a space inside the hub insertion hole 4b on the arrow B side from the end surface 10b is an inner space 4a. On the other hand, in the hub insertion portion 4, the small cylindrical portion 7 is elastically deformed in a state in which the small cylindrical portion 7 is expanded in the arrow C direction when the hub 9 is provided in the hub insertion hole 4b. That is, the restoring force due to the elastic deformation of the small cylindrical portion 7 is
Is transmitted to the hub 9 via the hub stop rib 7d. That is, between the hub stop rib 7d and the hub 9, a predetermined seal pressure due to the restoring force acts between the seal portion 7e, which is a contact point between the hub stop rib 7d and the hub 9, and the opening end portion 10e of the hub stop groove 10c. The seal 7e and the opening end 10e are watertight or airtight. In the small cylindrical portion 7, the hub stopping rib 7d and the hub stopping rib 7 are provided by the reinforcing rib 7c which is provided at a position corresponding to the hub stopping rib 7d by sandwiching the small cylindrical portion 7.
The rigidity in the vicinity of d is increased so that the predetermined restoring force due to elastic deformation of the small cylindrical portion 7 can be efficiently obtained.

Further, the hub 9 is provided with a needle insertion hole 12 as shown in FIGS. 1 to 3, and the needle insertion hole 12 is formed.
Is an end surface 11a of the small column portion 11 of the hub 9 on the arrow A side.
Is formed with a circular opening 12a centered on the axis Q1 and extends in the direction of arrow B from the end surface 11a. Further, an end portion 12b of the needle insertion hole 12 on the arrow B side reaches the inside of the main cylindrical portion 10, and the end portion 12b is in contact with a wall surface 10d of the main cylindrical portion 10. In addition, in the middle of the needle insertion hole 12, a tapered portion in which the diameter of the needle insertion hole 12 converges in the arrow B direction is appropriately formed. On the other hand, the main cylindrical portion 10 of the hub 9 is provided with a flow hole 13 adjacent to the arrow B side of the needle insertion hole 12 (on the right side of the paper surface of FIG. 2). The needle insertion hole 12 is provided in a cylindrical shape having a diameter smaller than that of the end portion 12b of the needle insertion hole 12 with the center thereof at the center. Further, the circulation hole 13 is provided in communication with the needle insertion hole 12 in the form of forming a circular opening on the wall surface 10d of the main columnar portion 10. Further, in the main cylindrical portion 10 of the hub 9, a piston engagement hole 15 having a circular cross section perpendicular to the axis Q1 and concentric with the axis Q1 is formed so as to communicate with and adjoin the arrow B side of the flow hole 13. The piston engagement hole 15 is provided on the arrow B side and is open to the outside at the end surface 10b of the main columnar portion 10.
The piston engagement hole 15 is composed of two parts, an engagement holding portion 16 on the arrow A side and an introduction portion 17 on the arrow B side, and the engagement holding portion 16 is a substantially cylindrical shape concentric with the axis Q1. The diameters of both ends of the arrow A side and the arrow B side are tapered so as to converge in the arrow A direction and the arrow B direction, respectively. Further, the end portion side of the engagement holding portion 16 on the arrow A side is communicated and connected by the circulation hole 13. The introduction portion 17 is in communication with and adjoins the end portion of the engagement holding portion 16 on the arrow B side, and the diameter of the introduction portion 17 increases in the arrow B direction. Therefore, in the main columnar portion 10, a portion sandwiched by the wall surface 16 a facing the engagement holding portion 16 and the wall surface 17 a facing the introduction portion 17 is a boundary portion between the engagement holding portion 16 and the introduction portion 17. A projecting portion 20 projecting toward the axis Q1 is formed with 19 as the apex.

On the other hand, as shown in FIGS. 2 and 3, an injection needle 21 is inserted into the needle insertion hole 12 of the hub 9,
The tip of the injection needle 21 is located outside the syringe body 2, and the injection needle 21 is inserted into the needle insertion hole 12 from the rear end. Further, the rear end of the injection needle 21 is in contact with the wall surface 10d formed on the arrow B side of the needle insertion hole 12, and is a medium circulation hole penetrating from the tip of the injection needle 21 to the rear end side. 21
The "a" and the flow hole 13 communicate with and adjoin to each other in the directions of arrows A and B. Further, the adhesive 22 is injected into the needle insertion hole 12 so as to fill the space between the injection needle 21 and the hub 9 and is solidified.

As shown in FIGS. 1 and 2, the syringe 1 is provided with a piston 23 (note that FIG. 2 is a schematic cross-sectional view of the syringe 1; Main body 25, outer pressing plate 27, inner pressing plate 2
Regarding 9, the packing support portion 30, and the hub engagement portion 31,
For convenience, the side surface is shown instead of the cross section. ). Piston 2
3 is a rod-shaped piston body 2 extending in the directions of arrows A and B
5, the piston body 25 is provided with two congruent flat plate portions 25a in the shape of a rectangular plate, which are elongated in the directions of arrows A and B, integrally intersecting each other in a cross-shaped cross section. ing. The width of the plate surface of the flat plate portion 25a perpendicular to the directions of arrows A and B is substantially equal to the inner diameter of the locking rib 3b of the main cylindrical portion 3, and the piston body 25 is
It is provided so as to be inserted into the main cylindrical portion 3 through the opening end portion 3a from the arrow A side. Each flat plate portion 25a of the piston main body 25 is provided with a flat plate portion 2a near the arrow A side.
A wedge-shaped notch 26 is provided in the direction of the axis (that is, axis Q1) of the piston body 25 from both sides of 5a. The four notches 26 are provided at positions aligned with each other in the directions of arrows A and B. A circular plate-shaped outer pressing plate 27 having a plate surface perpendicular to the directions of arrows A and B is integrally provided with the piston body 25 on the end portion side of the piston body 25 on the arrow B side. A circular plate-shaped inner pressing plate 29 having a plate surface perpendicular to the directions of arrows A and B is provided integrally and concentrically with the piston body 25 on the end portion side of the piston body 25 on the arrow A side. (Thus, the inner pressing plate 29 is located inside the main cylindrical portion 3), and the diameter of the inner pressing plate 29 is substantially equal to the inner diameter of the main cylindrical portion 3 (thus, the inner pressing plate 2).
The diameter of 9 is larger than the inner diameter of the locking rib 3b of the main cylindrical portion 3. ). As shown in FIG. 2, the inner pressing plate 29 is provided with a packing support portion 30 on the arrow A side thereof, and the packing support portion 30 has a columnar columnar portion 30a extending in the directions A and B. Are provided concentrically with the inner pressing plate 29. The diameter of the columnar portion 30a is smaller than the diameter of the inner pressing plate 29, and the columnar portion 30a is provided integrally with the inner pressing plate 29 on the arrow A side of the inner pressing plate 29. On the arrow A side of the columnar portion 30a, as shown in FIGS. 1 and 2, an outer diameter that extends concentrically with the columnar portion 30a in the directions of arrows A and B and that is substantially equal to the inner diameter of the small cylindrical portion 7 is provided. A columnar insertion columnar portion 30b having a is formed integrally with the columnar portion 30a. Further, a hub engaging portion 31 is provided on the insertion column portion 30b on the arrow A side.
Is a columnar cylindrical portion 31a extending in the directions of arrows A and B.
Are provided concentrically with the insertion column portion 30b. The diameter of the cylindrical portion 31a is smaller than the diameter of the inserted cylindrical portion 30b, and the cylindrical portion 31a is indicated by the arrow A of the inserted cylindrical portion 30b.
It is provided integrally with the insertion column portion 30b on the side. On the arrow A side of the columnar portion 31a, a hemispherical insertion portion 31b having a diameter larger than that of the columnar portion 31a is integrally provided with the columnar portion 31a so that the spherical surface 31c side faces the arrow A side. Is provided with a plurality of streak-shaped grooves 32 along the spherical surface 31c from the arrow A side tip portion toward the arrow B side. The diameter of the cylindrical portion 31a is substantially equal to the inner diameter of the boundary 19 of the piston engagement hole 15 provided in the hub 9, and therefore the diameter of the insertion portion 31b is larger than the diameter of the boundary 19. It is getting bigger. Further, the insertion portion 31b is the engagement holding portion 1 of the piston engagement hole 15.
The size is such that it can be fully inserted and held in the 6.

On the other hand, as shown in FIG. 1, a packing 33 made of a flexible resin is supported and provided on the packing supporting portion 30. The packing 33 is a syringe 1
00 has a packing main body 35 that is aligned and inserted into the main cylindrical portion 3 of 00, and the packing main body 35 has an engagement hole 3 that penetrates the packing main body 35 in the directions of arrows A and B.
5a is provided. Further, in the engagement hole 35a, the columnar portion 30a of the packing support portion 30 and the insertion columnar portion 30b.
Is partially penetrated. That is, the packing 33 is engaged with the packing support portion 30 in a manner of penetrating the packing support portion 30 into the engagement hole 35a, and is provided by being supported by the packing support portion 30 by the engagement. A support surface 35h perpendicular to the arrow A and B directions is formed at the end of the packing main body 35 on the arrow B side, and the support surface 35h is susceptible to the force in the arrow A direction by the inner pressing plate 29. In addition, it is in contact with the inner pressing plate 29. Further, the packing 33 and the columnar portion 30a in the engagement hole 35a.
Is in a close contact state, that is, in a water-sealed state. Further, inside the packing body 35, a hollow clearance space 35f is formed so as to surround the engagement hole 35a from the arrow C side and communicate with the engagement hole 35a adjacently (hence, the clearance). The space 35f has an arrow A
The side, the arrow B side, and the arrow C side are surrounded by the packing main body 35, and are in contact with the insertion columnar portion 30b of the packing support portion 30 on the arrow D side. ). In the portion of the engagement hole 35a on the arrow A side of the clearance space 35f, the packing 33 and the insertion columnar portion 30b are in contact with each other, but are not in a close contact state, that is, in a water-sealed state. .
That is, air or liquid may flow between the clearance space 35f and the outside of the packing body 35 on the arrow A side through the engagement hole 35a. The packing body 35 has a tapered portion 35b on the arrow A side. The inner shape of the tapered portion 6 of the syringe body 2 is a tapered shape whose inner diameter is reduced in the direction of arrow A at a predetermined rate K1 as described above, whereas the tapered portion 35b is in a natural state. Is a tapered shape whose outer diameter is reduced by a predetermined rate K2 which is larger than the predetermined rate K1. That is, when the tapered portion 35b in a natural state contacts the inside of the tapered portion 6 and the end portion 35d on the arrow B side of the tapered portion 35b contacts the inner peripheral surface 6a of the tapered portion 6, the tapered portion 35b is tapered. Part 3
A spare space 51 is formed between the surface 35e other than the end portion 35d of 5b (that is, a liquid pressing surface that can press the injection medium) and the inner peripheral surface 6a of the tapered portion 6. The packing support portion 30 is in a state of penetrating the engagement hole 35a.
The part of the insertion cylindrical portion 30b on the arrow A side is a tapered portion 35.
It projects further to the arrow A side than b. When the tapered portion 35b of the packing 33 is in a natural state, the end portion 35d of the tapered portion 35b is connected to the tapered portion 6 of the syringe body 2.
In the state of being brought into contact with the inside of the syringe, as shown in FIG. 1, the insertion column portion 30b of the packing support portion 30 engaging with the packing 33 is in a state of being inserted into the hub insertion hole 4b of the syringe body 2. , Spherical surface 3 of insertion portion 31b of hub engaging portion 31
The shape of the packing 33 is set so that 1c is in contact with the wall surface 17a of the piston engagement hole 15 that faces the introduction portion 17. The outer diameter of the packing main body 35 of the packing 33 is substantially the same as that of the inner pressing plate 29. However, on the outer peripheral side of the packing main body 35, a circular ring shape along the outer circumference of the packing main body 35 is formed. Folds 35c are doubled in the directions of arrows A and B. Therefore, the packing 33 is inserted into the main cylindrical portion 3 of the syringe body 2 in such a manner that the vicinity of the fold 35c of the packing body 35 is contracted by elastic deformation in the direction toward the axis Q1, that is, in the direction of arrow D. That is, the packing 33 and the main cylindrical portion 37 are in close contact with each other at the folds 35c and the inner peripheral surface 3c, and the packing 33 and the main cylindrical portion 3 are sealed with a water seal. The outer surface of the packing main body 35, that is, the surface on which the folds 35c are formed is a sliding surface 35g facing the inner peripheral surface 3c of the syringe main body 2, and the packing 33 is The sliding surface 35g is in contact with the inner peripheral surface 3c. Since the inner peripheral surface 3c and the sliding surface 35g are formed smoothly, the packing 33
The piston 23 in which the is attached is the inner space 2 of the main cylindrical portion 3.
In a, it is slidable in the directions of arrows A and B.

The syringe 1 is constructed as described above, and the syringe 1 is used and discarded after use as follows. First, the injection needle 21 of the syringe 1 is advanced into the injection medium 52 contained in a drug bottle (not shown), the piston 23 is pulled in the direction of arrow B with respect to the syringe body 2, and the pressure difference causes The injection medium 52 inside the medium circulation hole 21a of the injection needle 21 and the circulation hole 1 of the hub 9
3, through the piston engagement hole 15, into the medium holding space 53 on the injection needle 21 side of the piston 23 in the hole inner space 4a of the hub insertion portion 4 and the inner space 2a of the syringe body 2, the syringe 1 Is filled with injection medium 52. In addition,
When the injection medium 52 is filled, a differential pressure in the arrow B direction acts on the hub 9 due to the differential pressure between the outside and the medium holding space 53, but the restoring force of the hub insertion portion 4 in the arrow D direction is exerted. Since the size is set to the predetermined value as described above, the hub 9 and the hub insertion portion 4 are set even for the maximum expected differential pressure.
The seals between the seal portions 7e on the arrow A side and the seal portions 7e on the arrow B side and the open end portions 10e do not come apart.

After filling the injection medium 52, the injection needle 21 of the syringe 1 is pierced at the injection site of the patient. Next, the outer pressing plate 27 of the piston 23 is pushed in the direction of arrow A, and the piston 2
3 is driven in the direction of arrow A with respect to the syringe body 2.
The injection medium 52 in the medium holding space 53 is pressurized and the hub 9
Piston engagement hole 15, communication hole 13, and injection needle 2
It flows into the body at the injection site of the patient through the first medium circulation hole 21a. It should be noted that the injection medium 52 is pressurized, and the action force due to the pressure of the injection medium 52 is applied to the hub 9 from the end face 10b side of the hub 9 adjacent to the injection medium 52 in the direction of arrow A, but Since the restoring force of the portion 4 in the direction of the arrow D is set to a predetermined magnitude as described above, the portion between the hub 9 and the hub insertion portion 4 is set to the maximum expected acting force. Then, the seal between the seal portions 7e on the arrow A side and the arrow B side and the open end portions 10e cannot be removed. After injecting the injection medium 52 up to a predetermined amount into the body of the patient at the injection site, the taper portion 35 of the packing 33 is thus removed.
The end portion 35d of b abuts on the inside of the tapered portion 6 of the syringe body 2, and the insertion portion 31 of the hub engaging portion 31 of the piston 23
b is the piston engagement hole 15 of the hub 9 as shown in FIG.
Of the introduction hole 17 in contact with the wall surface 17a, that is,
After driving the piston 23 to the injection end position P2 in the figure, the entire syringe 1 is pulled in the direction of arrow B with respect to the patient, and the injection needle 21 is pulled out from the injection site of the patient.

After pulling out the injection needle 21, the injection needle storing operation is performed as follows. In the injection needle storing operation, first, the engaging operation between the piston 23 and the hub 9 is performed as follows. That is, the outer pressing plate 27 of the piston 23 is further pressed with a finger in the direction of arrow A to press the piston body 25 in the direction of arrow A, and the insertion columnar portion 30b of the packing support portion 30 and the hub engaging portion 31 are pushed. , In the direction of arrow A in the hub insertion hole 4b. Immediately before starting the needle accommodating operation, the piston 23 is positioned such that the tapered portion 35b in the natural state is located inside the tapered portion 6, and the tapered portion 35b is located on the arrow B side. End portion 35d abuts on the inner peripheral surface 6a of the tapered portion 6, and a margin space 51 is formed between the surface 35e other than the end portion 35d of the tapered portion 35b and the inner peripheral surface 6a of the tapered portion 6. There is. Therefore, the piston body 2
In the packing 33, the portion of the packing 33 on the arrow B side from the vicinity of the end portion 35d in contact with the taper portion 6 is compressed in the arrow A and B directions by pressing in the arrow A direction of 5 while the other portion is the surface. 35e is pushed out in the direction of arrow A using the spare space 51 so as to approach the tapered portion 6. Therefore, since the amount of elastic compression in the packing 33 is reduced as much as possible by the extra space 51, the piston 23 can be operated with a force as small as possible. Further, since the clearance space 35f is formed inside the packing body 35, when the packing body 35 is elastically compressed, the clearance space 35f is also reduced together with the packing body 35. Therefore, since the amount of elastic compression in the packing 33 is reduced by the amount of the clearance space 35f, the piston 23 can be operated with a force as small as possible. Also,
Immediately before starting the needle accommodating operation, as shown in FIG. 1, the hole inner space 4a (that is, the medium holding space 53) existing between the end surface 10b of the hub 9 and the insertion cylindrical portion 30b on the piston 23 side. Also, the spare space 51 (that is, the medium holding space 53) is filled with the remaining injection medium 52. The remaining injection medium 52 is pressurized by starting the operation of accommodating the injection needle and pressing and moving the piston 23 in the direction of arrow A as described above. However, the insertion portion 31b is provided with the plurality of grooves 32 as described above, and the grooves 32 are not blocked even when the insertion portion 31b and the wall surface 17a are pressed and brought into contact with each other. Therefore, even when the insertion portion 31b and the wall surface 17a are pressed and brought into contact with each other, the groove space 32a is communicated with the space 4a in the hole or between the spare space 51 side and the engagement holding part 16 side.
Alternatively, the pressurized residual injection medium 5 in the spare space 51
2 flows toward the engagement holding portion 16 side through these grooves 32 (because there is no water-tightness between the insertion cylindrical portion 30b and the small cylindrical portion 7, the injection medium 52 in the extra space 51 has the insertion cylindrical portion (It may flow toward the space 4a in the hole through the portion 30b and the small cylindrical portion 7), and further, the flow hole 13 and the injection needle 21.
Is discharged to the outside through the medium circulation hole 21a. That is, even when the injection needle storing operation is started and the piston 23 is pressed and moved in the direction of arrow A, the residual injection medium 52 pressurized in the hole space 4a or the margin space 51 is appropriately discharged to the outside. Since the pressure is not increased as much as possible, the resistance due to the residual pressure of the injection medium 52 is not applied to the piston 23 as much as possible, and the piston 23 is pressed and moved in the direction of arrow A with the smallest possible force. Further, while the packing 33 is elastically contracted, the insertion columnar portion 30 of the packing support portion 30 is
b and the hub engaging portion 31 are pressed and moved in the direction of the arrow A in the hub insertion hole 4b, so that the insertion portion 3 of the hub engaging portion 31
1b is pushed and moved in the direction of arrow A from the introduction portion 17 of the piston engagement hole 15 toward the engagement holding portion 16. That is,
By pushing and moving the piston 23 in the direction of arrow A, the insertion portion 31b is pushed against the wall surface 17a of the introduction portion 17. However, the spherical surface 3 is formed on the arrow A side of the insertion portion 31b.
Therefore, the insertion portion 31b is formed such that the cross section perpendicular to the axis Q1 is reduced in the direction of arrow A, and the insertion portion 31b is pressed against the wall surface 17a at the spherical surface 31c. Further, the introduction portion 17 is also formed in a tapered shape in which the inside thereof is reduced in the direction of arrow A. Therefore, the insertion portion 31b is inserted into the introduction portion 17 by the arrow A.
By pushing in the direction, the insertion portion 31b and the wall surface 17
The stress due to the pressure acting between the protruding portion 20 and the protruding portion 20 forming a is elastically contracted with respect to the insertion portion 31b in a cross-sectional area perpendicular to the axis Q1 of the protruding portion 20. In contrast, the inside of the introduction portion 17 is elastically expanded in the direction of the arrow C, and each effectively acts. Eventually, the cross-sectional area of the insertion portion 31b perpendicular to the axis Q1 is reduced, and the inside of the introduction portion 17 is expanded in the arrow C direction, so that the insertion portion 31b is pressed in the arrow A direction.
Moves in the direction of arrow A in the introduction section 17. Further, the piston 23 is pressed in the direction of arrow A, and the insertion portion 31b is further moved in the direction of arrow A in the introduction portion 17, so that the insertion portion 31b is moved from the arrow A side to the introduction portion 17 and the engagement holding portion 16. The engagement holding portion 1 in such a manner that the boundary portion 19 with
By moving the insertion portion 31b to the 6 side and completely inserting the insertion portion 31b into the engagement holding portion 16, the pressing of the piston 23 is stopped. When the insertion portion 31b is completely inserted into the engagement holding portion 16, the hub engagement portion 31 and the piston engagement hole 15
Are engaged with each other, and the engagement operation between the piston 23 and the hub 9 is completed. Note that the pressing force in the arrow A direction acts on the insertion portion 31b, so that the pressing force in the arrow A direction also acts on the hub 9. However, the hub 9 can be connected to the syringe main body 2 via the hub stopper rib 7d of the hub insertion portion 4 or the end wall 8.
It can be or can be supported in the direction of the arrow B by a hand that supports. Therefore, the hub 9 hardly moves in the arrow A direction or the like even when receiving the pressing force, and the hub 9 does not come out of the hole 8a of the end wall 8 in the arrow A direction.

Next, the piston 23 is pulled with respect to the syringe body 2 in the direction of arrow B with a predetermined pulling force. That is,
An acting force in the arrow B direction due to a predetermined pulling force acts on the piston 23 and the insertion portion 31b of the hub engaging portion 31. By the way, the restoring force of the hub insertion portion 4 in the direction of arrow D is set to a predetermined magnitude as described above, and therefore, the action force in the direction of arrow B due to the predetermined pulling-out force is set to the hub. 9 and the hub insertion portion 4, the seals between the seal portions 7e on the arrow A side and the open end portions 10e on the arrow B side are released, and therefore, the hub stop rib 7d and the hub stop groove 1 are removed.
0c is disengaged. Hub stop rib 7d and hub stop groove 10
At the same time as releasing the engagement with c, the hub 9 is further advanced in the direction of arrow B, and is pulled until the hub 9 completely comes out of the hub insertion hole 4b in the direction of arrow B. At this time, the hub 9 and the hub insertion hole 4
Since the clearance space 49 is formed between the hub 9 and the hub b, the hub 9 and the small cylindrical portion 7 are brought into contact with each other only via the hub stop rib 7d. After the engagement with the hub stop groove 10c is released, it can be easily performed with a small force.

Further, the piston 23 is pulled, and the injection needle 21 fixedly inserted on the arrow A side of the hub 9 is inserted from the hole 8a of the end wall 8 into the hub insertion hole 4b in the direction of arrow B, and further arrow B.
Is inserted into the inner space 2a of the main cylindrical portion 3 in the direction, and the tip of the injection needle 21 is completely inserted into the inner space 2a.
Pull the piston 23 in the direction of arrow B. The piston 23 is further pulled, and as shown in FIG. 5, the inner pressing plate 29 is pulled to a position where it abuts on the locking rib 3b of the main cylindrical portion 3 of the syringe body 2 to stop the piston 23. Then
The notch 26 of the piston body 25 is positioned near the open end 3a of the syringe body 2. Then the piston 23
To the arrow C direction. For the syringe body 2,
By applying a force in the direction of arrow C to the piston 23, the piston body 25 is broken at the notch 26 formed in the piston body 25, which is structurally weak against bending stress. Is divided into a part on the arrow A side and a part on the arrow B side. Next, the broken portion of the syringe body 2 side and the portion of the outer pressing plate 27 of the piston 23 are discarded.
Since the injection needle 21 is completely inserted and stored in the inner space 2a of the syringe body 2 while being retained by the tip of the remaining piston 23, the injection needle 21 injures a hand or the like, There is less risk of secondary infections and therefore safe disposal. As described above, the operation of storing the injection needle is completed, and the use of the syringe 1 and the disposal after use are all completed.

In the above embodiment, the packing 33 is used.
The clearance space 35f is formed so as to communicate with the outside of the packing 33 through the engagement hole 35a and the like, but the clearance space 3f is compressed when the packing 33 is compressed.
As long as 5f can be reduced and changed, the clearance space 35f may be formed so as not to communicate with the outside of the packing 33, that is, inside the packing 33.

In the above-mentioned embodiment, the packing 33 is used.
The clearance space 35f is formed adjacent to the engaging hole 35a, but the clearance space 35f is inside the packing 33, and the engaging hole 35a and the sliding surface 35g.
And the clearance space 35f is opened to the support surface 35h of the packing main body 35 and is adjacent to the inner pressing plate 29, as shown by the chain double-dashed line in FIG. It may be formed in a shape.

In order to prevent the injection medium 52 and air from entering the clearance space 35f, the clearance space 35f is made of a softer material than the packing 33, such as rubber, soft plastic, or porous rubber having flexibility. ,
It may be filled with a soft material such as porous plastic.

In the above embodiment, the piston side engaging means is the hub engaging portion 31 in the form of a ridge and the hub side engaging means is the piston engaging hole 15 in the shape of a hole. The piston-side engaging means may be provided in the form of a hole, and the hub-side engaging means may be provided in the form of a ridge, provided that the engaging means and the hub-side engaging means are insertably engageable with each other.

As described above, the first aspect of the present invention has a syringe such as a cylindrical syringe 100 having a liquid holding space such as the medium holding space 53 formed therein, and the syringe. A hub such as the hub 9 is detachably inserted and provided, and the injection needle 2 is provided on the side of the hub facing the liquid holding space.
1. A syringe needle such as 1 is provided by joining, hub side engaging means such as a piston engaging hole 15 is provided on the side of the hub facing the liquid holding space, and a piston body such as a piston body 25 is provided in the syringe. The hub side engaging means is provided so as to be inserted inside the syringe, and the piston side engaging means such as the hub engaging portion 31 is provided in the piston body so as to face the hub side engaging means of the hub. And a closing member such as a packing 33 formed of an elastic material on the piston main body, which is provided so as to be insertably engageable with the inside of the syringe.
It is configured such that it is closed in the axial direction such as the B direction and is movable in the axial direction together with the piston body with respect to the syringe, and a deformation promoting space such as a clearance space 35f is formed inside the closing member. Therefore, when the closing member is elastically compressed to engage the piston and the hub with the needle accommodating operation, the deformation promoting space inside the closing member can be compressed with a smaller force than the compression of the elastic material. Therefore, the amount of elastic compression in the closing member is reduced by the amount of the deformation promoting space, and therefore, the piston and the hub can be engaged with a force as small as possible, thereby facilitating the needle accommodating operation. it can. In addition, in the second invention of the present invention, in the syringe of the first invention, since the deformation promoting space is hollow, it is possible to compress the deformation promoting space as easily as possible in addition to the effect of the first invention. Therefore, the engagement between the piston and the hub becomes easier. Further, the third invention of the present invention is, in the injector of the first invention, since the deformation promoting space is configured by filling a soft material softer than the closing member, the effect of the first invention is obtained. In addition, since the injection medium and air are prevented from entering the deformation-promoting space, the amount of injection medium retained in the liquid holding space inside the syringe or the amount of air remaining in the liquid holding space can be more accurately grasped and trusted. The property is improved. A fourth invention of the present invention is the piston such as the piston 23 used in the syringe of the first invention, wherein the piston has a piston body such as a piston body 25, and a hub is provided on the tip side of the piston body. A piston-side engaging means such as an engaging portion 31 is provided so as to be insertably engageable with the hub-side engaging means, and a closing member such as a packing 33 formed of an elastic material on the piston body is used as the closing member. Is capable of closing the inside of the syringe in the axial direction such as the arrow A and B directions, and is provided so as to be movable in the axial direction together with the piston body with respect to the syringe, and the clearance space 3 is provided inside the closing member.
Since the deformation promoting space such as 5f is formed, when the piston according to the fourth invention is applied to the syringe, the same effect as that of the first invention can be obtained. Further, a fifth invention of the present invention is, in the piston of the fourth invention, configured so that the deformation promoting space is hollow, and therefore when the piston according to the fifth invention is applied to a syringe, it is the same as the second invention. The effect of is born. Further, a sixth aspect of the present invention is, in the piston of the fourth aspect, the deformation promoting space is configured by filling a soft material that is softer than the closing member. When applied to a syringe, the same effect as the third invention is produced. A seventh aspect of the present invention has a main body such as a packing main body 35 made of an elastic material, and forms a sliding surface against the syringe such as a sliding surface 35g around the main body, and one end of the main body is formed. A liquid pressing surface such as a surface 35e, a supporting surface such as a supporting surface 35h at the other end of the main body, and a piston engaging insertion space such as an engaging hole 35a provided in the main body. Since the deformation promoting space such as the clearance space 35f is formed between the mating insertion space and the sliding surface against the syringe, when the closing member according to the seventh invention is applied to the piston, it is the same as the fourth invention. The effect of is born. Further, in the eighth invention of the present invention, in the closing member of the seventh invention, since the deformation promoting space is made hollow, when the closing member according to the eighth invention is applied to a piston, a fifth invention is obtained. The same effect as is produced. Further, a ninth aspect of the present invention is the closing member according to the seventh aspect, in which the deformation promoting space is filled with a soft material softer than the main body. When is applied to the piston, the same effect as the sixth invention is produced.

[Brief description of drawings]

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing the vicinity of a hub and a tip of a piston in an example of a syringe according to the present invention.

FIG. 2 is a schematic cross-sectional view showing the entire injector shown in FIG.

FIG. 3 is a view in the vicinity of a hub insertion portion of the syringe shown in FIG.

FIG. 4 is a view of the hub insertion portion of the syringe shown in FIG. 2 as seen in the direction of arrow B.

FIG. 5 is a diagram showing a piston breaking operation process in the injector shown in FIG. 2;

FIG. 6 is a schematic diagram showing a positional relationship between a syringe and a piston in an example of a conventionally proposed disposable syringe.

[Explanation of symbols]

 1 ... Syringe 9 ... Hub 15 ... Hub side engaging means (piston engaging hole) 21 ... Injection needle 23 ... Piston 25 ... Piston body 31 ... Piston side engaging means (hub engaging part) 33 ... Closing means (packing) 35 ... Main body (packing main body) 35a ... Piston engagement insertion space (engagement hole) 35e ... Liquid pressing surface (front surface) 35f ... Clearance space (deformation promotion space) 35g ... … Syringe sliding surface (sliding surface) 35h …… Supporting surface 53 …… Liquid holding space (medium holding space) 100 …… Syringe arrow A, B direction …… Axial direction

Claims (9)

[Claims] 1. A cylindrical syringe having a liquid holding space formed therein, wherein a hub is removably inserted into the syringe and the syringe is provided on the side of the hub facing the liquid holding space. A needle is provided by joining, a hub side engaging means is provided on a side of the hub that faces the liquid holding space, a piston body is provided in the syringe in a form inserted into the syringe, and the piston body is provided. The piston side engaging means is provided so as to be inserted into and engageable with the hub side engaging means so as to face the hub side engaging means of the hub, and a closing member formed of an elastic material is provided on the piston body. And a closing member that closes the inside of the syringe in the axial direction and is provided movably in the axial direction together with the piston body with respect to the syringe, and a deformation promoting space is formed inside the closing member. Syringe. 2. The syringe according to claim 1, wherein the deformation promoting space is hollow. 3. The syringe according to claim 1, wherein the deformation promoting space is filled with a soft material that is softer than the closing member. 4. The piston used in the syringe according to claim 1, wherein the piston has a piston main body, and a piston side engaging means is inserted into a tip end side of the piston main body with respect to the hub side engaging means. Engageably provided, a closing member formed of an elastic material on the piston body, the closing member can close the inside of the syringe in the axial direction, and with respect to the syringe, in the axial direction together with the piston body. A piston which is movably provided and has a deformation promoting space formed inside the closing member. 5. The piston according to claim 4, wherein the deformation promoting space is hollow. 6. The piston according to claim 4, wherein the deformation promoting space is filled with a soft material that is softer than the closing member. 7. A main body made of an elastic material, a sliding surface for a syringe is formed around the main body, a liquid pressing surface is formed at one end of the main body, and a support surface is formed at the other end of the main body. A closure member for a syringe, wherein the main body is provided with a piston engagement insertion space, and a deformation promoting space is formed between the piston engagement insertion space and the syringe sliding surface. 8. The closing member according to claim 7, wherein the deformation promoting space is hollow. 9. The closing member according to claim 7, wherein the deformation promoting space is filled with a soft material softer than the main body.