JP2010259718A - Safe disposable syringe - Google Patents

Abstract

To provide a safe disposable syringe applicable to a small syringe, for example, a syringe having a size of less than 1 cc.
A safe disposable syringe includes an injection outer cylinder 3, a plunger 5 extending to the injection outer cylinder 3, a piston 6 mounted on the plunger 5 and formed by a first engagement member 611 '; A needle seat 4 having a rear end face that is appropriately extended to the injection outer cylinder 3 and disposed on the injection outer cylinder 3 is included. The needle seat 4 extends from the rear end surface and defines a flow path 46 formed by the second engagement member 44 '. The flow path 46 has a stop end that stops at the rear end face. The second engagement member 44 ′ has a stop end that stops at the rear end face, and is disposed away from the stop end of the flow path 46. The flow path 46 is dented radially inward from the outer surface of the needle seat 4 along the axis of the outer surface of the needle seat 4.
[Selection] Figure 2

Description

The present invention includes a safe disposable syringe, more specifically a needle seat with an injection barrel and cannula, which engages a piston on the plunger to retract the cannula into the injection barrel before discarding the syringe Relates to possible safe syringes.

1 shows an injection outer cylinder 11, a plunger 14 extending to the injection outer cylinder 11, a piston 15 mounted on the plunger 14 and formed by an engagement groove 151, and a needle extending to the injection outer cylinder 11. The seat 13 is formed by a locking tongue 131 that is connected to the cannula 16 and engageable with the engagement groove 151, so that the safe disposable syringe is discarded after the cannula 16 is drawn into the injection barrel 11. 1 shows a safe disposable syringe that can be used. The needle seat 13 is formed by a needle groove 133 into which the cannula 16 extends, and a flow path 133 extending from one end of the needle groove 133 through the end surface 1311 of the locking tongue 131. The liquid flows between the 11 chambers. However, since the channel 132 passes through the locking tongue 131, it is necessary to increase the size of the locking tongue 131 so that the channel 132 can be formed therein. Therefore, the safe disposable syringe design described above is not suitable for application to small syringes, eg, syringes having a size of less than 1 cc.

The object of the present invention is to provide a safe disposable syringe which overcomes the aforementioned drawbacks associated with the prior art.

In accordance with the present invention, a safe disposable syringe has a front open end and a rear open end, an injection barrel defining a chamber and a shaft therein, and a front end extending from the rear open end into the chamber. A plunger, a piston mounted on the front end of the plunger and formed by the first engagement member, a cannula, and the front opening end of the syringe barrel are appropriately extended and arranged outward in the chamber A needle seat having a front end portion and a rear end portion disposed in the chamber and having a rear end surface on the front surface of the piston are provided. The needle seat has a central groove through which the cannula extends through the front end of the needle seat, and a flow path through which the liquid flows in communication with the central groove and the chamber. Is specified. The rear end surface of the rear end portion of the needle seat is formed by a second engagement member that is axially arranged and engageable with the first engagement member. The flow path has a first stop end that stops at the rear end surface of the rear end portion of the needle seat, and a second stop end that is on the opposite side of the first stop end and stops at the rear end surface of the rear end portion of the needle seat. Have. The second engagement member stops at the rear end surface of the rear end portion of the needle seat, and has a stop end disposed away from the first stop end of the flow path. The needle seat has an outer surface around the axis. The flow path is generally U-shaped and includes a radial extension section extending radially along the outer surface and two axial extension sections extending from the two ends of the radial extension section to the first and second stop ends, respectively. Have. The flow path is dented radially inward from the outer surface along the longitudinal axis of the outer surface.

Other features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings.
The fragmentary sectional view of the conventional safe disposable syringe. 1 is an enlarged perspective view of a preferred first embodiment of a safe disposable syringe according to the present invention. FIG. The top view of a 1st embodiment. The fragmentary fragmentary sectional view of suitable 1st Embodiment. Sectional drawing of the needle seat of suitable 1st Embodiment. The fragmentary fragmentary sectional view which illustrates the mechanism in which the liquid in a syringe barrel passes along the flow path and cannula of suitable 1st Embodiment. The fragmentary fragmentary sectional view which shows the mechanism in which a piston engages with the needle seat of suitable 1st Embodiment. The fragmentary fragmentary sectional view which shows the mechanism by which a needle seat and a cannula are drawn in the injection barrel of 1st Embodiment suitable. The fragmentary fragmentary sectional view which shows the mechanism in which a part of plunger is removed after a needle is drawn in the injection outer cylinder of suitable 1st Embodiment. Sectional drawing of the needle seat of suitable 2nd Embodiment of the safe disposable syringe by this invention. The needle seat and cannula are partial sectional views showing a state where the needle seat and the cannula are inclined at a specific angle with respect to the axis after being pulled into the injection barrel of the second preferred embodiment.

Before describing the present invention in more detail, the same reference numerals should be used to denote the same elements herein.

2-5, a first preferred embodiment of a safe disposable syringe according to the present invention has front and rear open ends 31, 32, in which a chamber 30 and a shaft (X) for receiving a medicament. Mounted on the front end 51 of the plunger 5, the plunger 5 having a front end 51 extending from the rear opening end 32 into the chamber 30 and formed by the protrusion 511. The piston 6 formed by the rear hole 621 for extending the protrusion 511 and the first engagement member 611 ′ opposite to the rear hole 621, the cannula 2, and the front opening end 31 of the injection outer cylinder 3. And a needle seat 4 having a front end 41 disposed outwardly in the chamber 30 and a rear end 42 disposed in the chamber 30 and having a rear end surface 420 in front of the piston 6. It is shown. The needle seat 4 further has an outer surface around the axis (X), a central groove 45 through which the cannula 2 extends through the front end 41 of the needle seat 4 and a rear end 42 of the needle seat 4. A flow path 46 that extends from the rear end face 420 and communicates with the central groove 45 and the chamber 30 to flow the liquid is defined. The rear end surface 420 of the rear end portion 42 of the needle seat 4 is formed by a second engaging member 44 'that is axially arranged and engageable with the first engaging member 611' (see FIG. 7). The channel 46 is generally U-shaped and stops at a first stop end 460 (see FIG. 5) that stops at the rear end surface 420 of the rear end portion 42 of the needle seat 4 and at a rear end surface 420 of the rear end portion 42 of the needle seat 4. And a second stop end 465. The second engagement member 44 ′ stops at the rear end surface 420 of the rear end portion 42 of the needle seat 4 (see FIG. 5), and has a stop end 440 disposed away from the first stop end 460 of the flow path 46. Have. The channel 46 includes a radial extension section 462 that extends radially along the outer surface, and two axial extension sections that extend from the two ends of the radial extension section 462 to the first and second stop ends 460, 465, respectively. Have This flow path 46 is dented radially inward from the outer surface of the needle seat 4 along the axis of the outer surface of the needle seat 4.

Preferably, the first and second engagement members 611 ', 44' are engageable with each other in a tongue-groove engagement method. In the present embodiment, the piston 6 is formed by an engagement groove 611 that defines the first engagement member 611 ′, and the rear end surface 420 of the rear end portion 42 of the needle seat 4 defines the second engagement member 44 ′. The locking tongue 44 is formed.

Preferably, since the volume of the flow path 46 is substantially the same as that of the engagement groove 611, the engagement groove 611 and the locking tongue 44 are engaged when all of the medicine received by the injection outer cylinder 3 is pushed out. After that, the remaining medicine in the flow path 46 can be pushed out using the air trapped in the engagement groove 611. Thereby, useless use of a medicine can be avoided.

In this embodiment, each axial extension section 461 of the flow path 46 has a depth (d) in the radial direction with respect to the axis (X) and a width (w) in the radial direction and in the horizontal direction with respect to the axis (X). . The ratio of the width of each axial extension section 461 of the flow path 46 to the circumferential length of the rear end 42 of the needle seat 4 is preferably less than 1/15. The ratio of the depth of each axial extension section 461 of the flow path 46 to the diameter of the rear end 42 of the needle seat 4 is preferably less than 1/7. In this embodiment, the width of each axial extension section 461 of the flow path 46 is 0.5 mm, and the depth of each axial extension section 461 of the flow path 46 is 0.5 mm.

In the present embodiment, the needle seat 4 is in the form of integral molding. The locking tongue 44 extends along the axis (X) of the injection outer cylinder 3. The first and second stop ends 460 and 465 of the channel 46 are disposed on both sides of the locking tongue 44.

The front end 41 of the needle seat 4 has a front end face 410. The central groove 45 includes a first section 451 extending from the front end surface 410 of the front end portion 41 of the needle seat 4, a second section 452 extending from the first section 451, and a third section 453 extending from the second section 452. , And a fourth section 454 extending from the third section 453 to the flow path 46. The first section 451 fits in a range from the front end surface 410 of the front end portion 41 of the needle seat 4 to the adjacent end 451 of the second section 452. The second section 452 extends from the adjacent end of the first section 451 to the adjacent end of the third section 453, forms a constriction 455 between the first section 451 and the second section 452, and contracts the cannula 2 Let Adhesive 8 fills the first section 451 of the central groove 45 and secures the cannula 2 to the needle seat 4. The rear end portion 42 of the needle seat 4 is formed by a neck portion 421. The injection outer cylinder 3 is formed by an inner shoulder 3111 disposed adjacent to the front opening end 31 of the injection outer cylinder 3 and is in contact with the neck portion 421 of the rear end portion 42 of the needle seat 4 so that the needle seat 4 is outside the injection. The accidental removal from the front opening 31 of the cylinder 3 is prevented.

The needle seat 4 has a cylindrical wall portion 40 (see FIGS. 2 and 5) defining a central groove 45 therein, and fins 43 having a large number of angular displacements spread radially from the outer surface of the cylindrical wall portion 40, The annular flange 471 is connected to the end of the fin 43 by frictional contact with the inner surface of the front opening end 31 of the injection outer cylinder 3. The needle seat 4 is formed by an annular fixing groove 431 between the annular flange 471 and the radially extending section 462 of the flow path 46. The sealing ring 47 is fixed to the fixing groove 431 and comes into sealing contact with the inner surface of the front opening end 31 of the injection outer cylinder 3.

The inner surface of the rear end portion of the injection outer cylinder 3 interconnects the cylindrical rear segment 321 extending from the rear opening end 32 of the injection outer cylinder 3, the central segment 323, the rear segment 321 and the central segment 323, And a transition segment 322 that traverses from the rear segment 321 to the central segment 323. The plunger 5 further includes a rear end portion 52, and an annular notch 513 disposed between the front end portion 51 and the rear end portion 52 of the plunger 5 and an axial notch from the annular notch 513 are disposed. It is formed by a first annular flange 512 and a second annular flange 512 ′ disposed between the annular notch 513 and the first annular flange 512. The annular notch 513 is disposed between the second annular flange 512 ′ and the rear end 52 of the plunger 5. The second annular flange 512 ′ has substantially the same area as the rear segment of the injection barrel 3. The first annular flange 512 has substantially the same area as the transition segment 322 of the injection barrel 3.

With reference to FIGS. 6 to 8, in operation, the liquid 9 in the injection barrel 3 is pushed by an external force acting on the plunger 5 and is injected into the patient through the flow path 46 and the cannula 2. As clearly illustrated in FIG. 7, when the engaging groove 611 of the piston 6 and the locking tongue 44 are completely engaged, the liquid 9 in the injection outer cylinder 3 is completely discharged therefrom. As illustrated in detail in FIG. 8, when the safe disposable syringe is discarded after use, the plunger 5 is pulled backward to place the needle seat 4 and the cannula 2 into the injection barrel 3. When the first annular flange 512 of the plunger 5 and the transition segment 322 on the inner surface of the rear end portion of the injection barrel 3 are joined, the plunger 5 is prevented from moving further rearward. In this state, the annular notch 513 is substantially flush with the rear end surface 320 of the injection outer cylinder 3, so that the plunger 5 can be separated by the annular notch 513 (see FIG. 9).

10 and 11 show a second preferred embodiment of a safe disposable syringe according to the present invention. The second preferred embodiment is that the locking tongue 44 is inclined with respect to the axis (X) of the injection barrel 3 and the engagement groove 611 extends along the axis (X) of the injection barrel 3. This is different from the embodiment.

As illustrated in the preferred embodiment, the flow path 46 does not pass through the second engaging member 44 ′ (eg, the locking tongue 44 formed on the rear end surface 420 of the rear end 42 of the needle seat 4). By forming the flow path 46 in the first engagement member 44 ′, the size of the second engagement member 44 ′ is made as small as possible so that the needle seat 4 can be pulled using the plunger 5 and inserted into the injection outer cylinder 3. It is possible to keep as long as possible between the member 611 ′ and the second engaging member 44 ′, thereby eliminating the aforementioned drawbacks associated with the prior art.

Although the invention has been described in connection with what are considered to be the most practical and preferred embodiments, the invention is not limited to the disclosed embodiments, but includes a variety of including the spirit and scope of the broadest interpretation. Other configurations and equivalents are also intended.

2 cannula 3 injection cylinder 4 needle seat 5 plunger 6 piston 8 adhesive 9 liquid 11 injection outer cylinder 13 needle seat 14 plunger 15 piston 16 cannula 30 chamber 31 front opening end 32 rear opening end 40 cylindrical wall 41 front end Part 42 rear end 43 fin 44 (44 ′) second engagement member 45 central groove 46 flow path 47 seal ring 51 front end 52 rear end 131 locking tongue 132 flow path 133 needle groove 1311 end surface 151 engagement groove 320 Rear end face 321 Rear segment 322 Transition segment 323 Central segment 410 Front end face 420 Rear end face 421 Neck 431 Annular fixing groove 440 Stop end 451 First section 452 Second section 453 Third section 454 Fourth section 455 Constriction 460 First stop end 461 Axial extension section 462 radial extension section 465 second stop end 471 annular flange 311 1 internal shoulder 511 protrusion 512 first annular flange 512
512 ′ second annular flange 512 ′
513 annular notch 611 (611 ′) first engagement member 621 rear hole X axis w width d depth

Claims (12)

The syringe barrel (3) has front and rear open ends (31, 32) in which a chamber (30) and an axis X for receiving the drug are defined;
A plunger (5) extends from the rear open end (32) into the chamber (30) and has a front end (51);
The plunger (5) is mounted on the front end (51) and is formed of a first engagement member (611 ′),
Having a cannula (2),
The needle seat (4) is properly extended from the front opening end (31) of the injection outer cylinder (3), and is disposed outward in the front end portion (41) of the chamber (30) and the chamber (30). It has a rear end part (42), has a rear end face (420) in front of the piston (6), and the needle seat (4) is connected to the front end part (41) of the needle seat (4). A central groove (45) through which the cannula (2) extends and a central groove (45) extending from the rear end face (420) of the rear end portion (42) of the needle seat (4) (45) and a flow path (46) through which liquid flows in communication with the chamber (30), the rear end surface (420) of the rear end portion (42) of the needle seat (4) Formed by a second engagement member (44 ′) that is arranged in a row and engageable with the first engagement member (611 ′),
The flow path (46) is opposite to the first stop end (460) and the first stop end (460) at the rear end surface (420) of the rear end portion (42) of the needle seat (4). And having a second stop end (465) that stops at the rear end surface (420) of the rear end portion (42) of the needle seat (4),
The second engagement member (44 ′) stops at the rear end surface (420) of the rear end portion (42) of the needle seat (4), and the first stop end (460) of the flow path (46). ), Having a stop end (440) arranged away from
The needle seat (4) has an outer surface around the axis (X), the flow path (46) is generally U-shaped, extends radially along the outer surface, and the radial extension section (462). Two axially extending sections (462) extending from the two ends of the first to the second stop ends (460, 465), respectively,
The flow path (46) is recessed radially inward from the outer surface of the needle seat (4) along the axis of the outer surface of the needle seat (4). Disposable syringe. The safe disposable syringe of claim 1, wherein the first and second engaging members (611 ', 44') are engageable with each other in a tongue-groove engagement manner. A piston (6) is formed by an engagement groove (611) defining the first engagement member (611 '), and the rear end surface (420) of the rear end portion (42) of the needle seat (4). 3. A safe disposable syringe according to claim 2, wherein is formed by a locking tongue (44) defining the second engagement member (44 '). A safe disposable syringe according to claim 3, wherein the volume of the flow path (46) is substantially the same as the engagement groove (611). Each axially extending section (461) of the channel (46) has a depth (d) in the radial direction relative to the axis (X) and a width (w) in the radial direction and in the horizontal direction relative to the axis (X). The ratio of the width of each axial extension section (461) of the flow path (46) to the circumferential length of the rear end (42) of the needle seat (4) is less than 1/15. And the ratio of the depth of each axial extension section (461) of the flow path (46) to the diameter of the rear end (42) of the needle seat (4) is less than 1/7. The safe disposable syringe according to claim 1. The needle seat (4) is in an integrally formed form, and the locking tongue (44) extends along the axis (X) of the injection outer tube (3), and the flow path (46) A safe disposable syringe according to claim 3, wherein first and second stop ends (460, 465) are arranged on both sides of the locking tongue (44). The front end portion (41) of the needle seat (4) has the front end surface (410), and the central groove (45) is the front end surface (41) of the front end portion (41) of the needle seat (4). 410) extending from the first section (451), a second section (452) extending from the first section (451), a third section (453) extending from the second section (452), A fourth section (454) extending from the third section (453) to the flow path (46), wherein the first section (451) is the front end (41) of the needle seat (4). The second section (452) converges from the front end face (410) to the adjacent end of the second section (452), and the second section (452) extends from the adjacent end of the first section (451) to the third section (453). Extends to the adjacent end, the first section (451) and the second Constriction between the action (452) to form a (455), deflating the cannula (2), secure disposable syringes according to claim 3. The needle seat (4) has a cylindrical wall portion (40) defining the central groove (45) therein, and fins (43) having a large number of angular displacements are external surfaces of the cylindrical wall portion (40). The safe disposable syringe according to claim 1, wherein the safe disposable syringe extends radially from and in frictional contact with the inner surface of the front open end (31) of the injection barrel (3). The injection outer cylinder (3) includes a cylindrical rear segment (321) whose inner surface at the rear end extends from the rear opening end (32) of the injection outer cylinder (3), a central segment (323), A rear end having a transition segment (322) interconnecting the rear segment (321) and the central segment (323) and crossing from the rear segment (321) to the central segment (323); The plunger (5) is disposed between the front end portion (51) and the rear end portion (52), and the annular notch (513) is axially spaced from the annular notch (513). Formed by a first annular flange (512) and a second annular flange (512 ′) disposed between the annular notch (513) and the first annular flange (512). 12 ′) has substantially the same area as the rear segment of the injection barrel (3), and a first annular flange (512) is substantially the same as the transition segment (322) of the injection barrel (3). The safe disposable syringe of claim 1 having the same area. The locking tongue (44) is inclined with respect to the axis (X) of the injection outer cylinder (3), and the engagement groove (611) is along the axis (X) of the injection outer cylinder (3). The safe disposable syringe of claim 11, wherein The rear end (42) of the needle seat (4) is formed by a neck (421), and the injection outer cylinder (3) is adjacent to the front open end (31) of the injection outer cylinder (3). A safe disposable syringe according to claim 1, formed by an internal shoulder (3111) to be arranged and in contact with the neck (421) of the rear end (42) of the needle seat (4). The needle seat (4) is formed by an annular fixing groove (431), the safe disposable syringe is fixed to the fixing groove (431), and sealed with the front opening end (31) of the injection outer cylinder (3). The safe disposable syringe of claim 1, further comprising a sealing ring (47) in contact.