JP3560889B2 - Needleless syringe - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a needleless syringe that performs a subcutaneous injection by jetting a fixed amount of a chemical solution inhaled from an injection hole of a nozzle.
[0002]
[Prior art]
The needleless syringe is a syringe that injects a drug solution into the patient's subcutaneous fluid by injecting a predetermined amount of the drug solution from the nozzle orifice of the nozzle at the tip and then jetting the drug solution again from the nozzle orifice. In other words, injection using a needleless syringe does not use a needle at the time of subcutaneous injection, and thus has the advantage of not causing pain, leaving no injection mark, and having no injection mistakes. It is also used when injecting.
[0003]
In general, such a needleless syringe has a configuration as shown in FIG. That is, the needleless syringe latches (fixes) or releases the piston driving rod (hereinafter abbreviated as piston rod) 25 connecting the front cylindrical portion 23 in which the nozzle 21 having the injection hole 21a is incorporated and the piston 24. The rear cylindrical portion 28 in which the latch mechanism 22 and the release switch 27 are incorporated is screwed with a screw portion 29.
A flange ring 20 is integrally fixed to a front portion of the piston rod 25, and a compression spring 26 is mounted between the flange ring 20 and a rear wall of the rear cylindrical portion 28 through the piston rod 25.
[0004]
When the rear cylindrical portion 28 of the needleless syringe is rotated and moved forward from the state shown in FIG. 9, the latch mechanism 22 latches the piston rod 25 and compresses the compression spring 26, and the compression force causes the piston rod 25 to move forward. Power is energized.
In this state, when the nozzle 21 of the needleless syringe is pressed against the suction port of the drug vial (not shown) and the rear cylindrical portion 28 is reversely rotated and retracted, the drug solution is put into the space formed between the nozzle 21 and the piston 24. Inhaled. When the release switch 27 is pressed while the nozzle 21 is pressed against the injection site after inhaling a predetermined amount of the drug solution, the latch mechanism 22 is released, the piston rod 25 is free, and moves forward at a high speed. It is pressurized by the piston 24 and injected subcutaneously from the injection hole 21a.
[0005]
[Problems to be solved by the invention]
The conventional needleless syringe is configured as described above, but in such a needleless syringe, if a strong force is required to press the release switch 27, the syringe may be shaken at the time of injection or the nozzle 21 may be moved from the injection site. Since the liquid medicine cannot be injected accurately due to movement or the like, the pushing force cannot be increased so much. As a result, the piston rod 25 may be erroneously started by inadvertently touching the release switch 27 before injecting after inhaling the drug solution. For this reason, for example, there is also a needleless syringe equipped with a stopper that can be prevented from being pushed by manually rotating the release switch 27.
[0006]
However, even if such a needleless syringe is used, after the piston rod 25 is latched to the rear cylindrical portion 28, the stopper of the release switch 27 is manually rotated to prevent the piston rod 25 from starting. There is a problem that the piston rod 25 is accidentally started due to neglect or forgetting.
The present invention has been made in view of such circumstances, and has as its object to provide a needleless syringe that can automatically prevent erroneous starting of the piston rod 25.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a needleless syringe according to the present invention is a needleless syringe that presses a piston, which has been preliminarily urged forward in a latched state, at a high speed into a drug solution inhaled from an injection hole of a nozzle, and injects the drug solution. In the front cylindrical portion incorporating a nozzle having an injection hole, and screwed to the front cylindrical portion, the concave portion provided in the longitudinal direction, and the longitudinal concave portion at the end opposite to the injection hole A rear cylindrical portion having a concave portion provided in a circumferential direction in a rotational direction for connecting and sucking a chemical solution, a ball receiver integrally provided on the rear cylindrical portion, and a plurality of balls in the ball receiver; A latch groove through which each part of the ball enters and exits is provided, and a piston driving rod held by the rear cylindrical portion via the ball receiver in a state where the ball is inserted; Longitudinal recess or circumferential recess And a contact surface provided to abut the ball when the ball is in the latch groove, the concave portion in the longitudinal direction with respect to the rear cylindrical portion, and A release switch in which the convex portion is movable along a circumferential concave portion, and a compression spring provided between the rear cylindrical portion and the release switch, wherein the ball is not contained in the latch groove. In the state, the ball comes into contact with the contact surface and the release switch is held against the compression spring.When the ball is in the latch groove, the ball passes over the contact surface. The release switch is brought into contact with the contact surface to hold the piston driving rod, and the urging force of the compression spring guides the convex portion of the release switch into the longitudinal concave portion to reach the end of the concave portion. Move, the ball receiver and the The release switch is inserted into the circumferential recess through a contact surface that contacts with the release switch, and the pressing operation of the release switch is prevented. .
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the needleless syringe of the present invention will be described in detail with reference to examples. 1 (a) and 1 (b) are a top view and a longitudinal sectional view of the needleless syringe of the present invention after injection.
As shown in FIG. 1, the needleless syringe of the present invention includes a nozzle 1 having an injection hole 1 a for inhaling a liquid medicine when the piston 4 with the seal member 4 a connected to the distal end retreats and ejecting the liquid medicine when the piston 4 moves forward. A front-side cylindrical portion 3 which is fixed by screwing or the like and has a chemical liquid amount display window 2 opened on the outer peripheral portion, and a piston rod 5 which is connected to the piston 4 inserted in the nozzle 1 and latches a piston rod 5 which can move in the axial direction ( The ball receiver 14 provided with a small hole 17 for moving the plurality of balls 11 in a direction perpendicular to the piston rod 5 and a release switch 7 provided with a contact surface 18 for controlling the ball 11 to fly out. Is inserted integrally with the compression spring 16 and the rear cylindrical portion 8 is integrally formed by screwing a screw portion 9.
[0009]
FIGS. 2A and 2B are a top view and a side view of the inner cylindrical portion of the rear cylindrical portion 8 in the above configuration, and FIGS. 3A and 3B are a top view and a side view of the release switch 7. FIGS. 4A and 4B are a top view and a side view showing a state where the release switch 7 is inserted into the rear cylindrical portion 8. A concave portion 8a and a concave portion 8b as shown in FIG. 2 which are features of the present invention are provided in an inner cylindrical portion of the rear cylindrical portion 8, and a convex portion 7a and a convex portion 7b shown in FIG. Is provided. By pushing the release switch 7 into the rear cylindrical portion 8, the projections 7a and 7b are disposed in the recesses 8a and 8b, respectively, as shown in FIG. 4, and the rotation of the release switch 7 is prevented. You.
[0010]
A flange ring 13 is fixed to the distal end of the piston rod 5, and a compression spring 15 is interposed between the flange ring 13 and the inner rear wall of the rear cylindrical portion 8 through the piston rod 5.
A number (for example, 0 to 5) for indicating the amount of the chemical is displayed on the liquid amount display window 2 in accordance with the rotation pitch on the cylindrical surface of the rear cylindrical portion 8 that has entered the front cylindrical portion 3. The number displayed in the chemical liquid amount display window 2 changes according to the movement of the rear cylindrical portion 8.
[0011]
When the rear cylindrical portion 8 of the needleless syringe is rotated clockwise (as viewed from the release switch 7 side), the rear cylindrical portion 8 moves forward together with the ball 11. When the ball 11 reaches the latch groove 12, a part of the ball 11 sinks into the latch groove 12, and at the same time, the contact surface 18 moves onto the ball 11 by the urging force of the compression spring 16. As a result, the piston rod 5 is latched by the rear cylindrical portion 8 via the ball 11 in the latch groove 12, and the release switch 7 hits the rear edge of the concave portion 8a of the rear cylindrical portion 8 by retreating the convex portion 7a. And the needleless syringe is in the state shown in FIG. Then, the projections 7a and 7b of the release switch 7 move to the rear of the advanceable zone as shown in FIG. 6 in the recesses 8a and 8b of the rear cylindrical portion 8, and the needleless syringe is used to inhale the drug solution. It becomes possible state.
[0012]
Next, when the nozzle 1 of the needleless syringe of FIG. 6 is pressed against the suction port of the drug solution vial (not shown) and the rear cylindrical portion 8 is rotated counterclockwise, the piston rod 5 keeps the forward force and the nozzle 1 It moves backward while sucking the chemical from the first injection hole 1a.
The ball 11 is in contact with the piston rod 5 at the contact surface 18 of the release switch 7, and when the rear cylindrical portion 8 is rotated in the direction of the arrow in FIG. When the rotation is transmitted to the release switch 7, the release switch 7 also rotates in the direction of the arrow (counterclockwise) in FIG. Thereby, the convex portion 7b and the convex portion 8b of the release switch 7 are moved to the forward-prohibition zone on the left side of the concave portion 8a and the concave portion 8b of the rear cylindrical portion 8 as shown in FIG.
[0013]
In the state of FIG. 8, the convex portion 7a and the convex portion 7b of the release switch 7 are blocked from moving forward by the concave portion 8a and the concave portion 8b, respectively, and the pushing of the release switch 7 is automatically prohibited. When performing the injection, the protrusion 7a is manually rotated clockwise to move from the push-in prohibited zone to the push-in zone, and then the release switch 7 is pushed in.
In this way, the rear switch 8 is rotated counterclockwise in the locked state, and the release switch 7 is automatically pushed into the prohibited state when the liquid medicine is inhaled. This prevents the chemical solution from being erroneously fired between the time when the predetermined amount of the chemical solution is inhaled and the time when the injection is performed.
In addition, the convex part 7b reinforces the strength of the convex part 7a, and can be omitted by giving the convex part 7a sufficient strength.
[0014]
As shown in the above embodiment, the present needleless syringe provides a release switch with a convex portion, and a concave portion having a zone in which the advance of the convex portion is prohibited by rotating the rear cylindrical portion. It is characterized by prohibiting the release switch from being pushed by mistake between injection and injection, and preventing the piston rod from starting accidentally.The shape and size of the protrusions and dents are limited by this embodiment It is not done.
[0015]
【The invention's effect】
The present needleless syringe of the present invention is configured as described above, and when the piston rod is rotated and retracted for inhaling the drug solution, the protrusion of the release switch automatically moves to the forward-prohibited portion of the concave portion of the rear cylindrical portion. By providing the moving mechanism, it is possible to prevent the piston rod from erroneously starting even if the release switch is inadvertently touched or pressed during the period from the start of the medical solution inhalation operation to the injection.
[Brief description of the drawings]
FIG. 1 is a top view (a) and a longitudinal sectional view (b) of a needleless syringe according to an embodiment of the present invention.
FIG. 2 is a top view (a) and a side view (b) of an inner portion of a rear cylindrical portion according to the present invention.
FIG. 3 is a top view (a) and a side view (b) of a release switch according to the present invention.
FIG. 4 is a top view (a) and a side view (b) in a state where a rear cylindrical portion and a release switch are coupled to each other.
FIG. 5 is a top view (a) and a longitudinal sectional view (b) of a needleless syringe according to an embodiment of the present invention.
FIGS. 6A and 6B are a top view and a side view in a state where the rear cylindrical portion and the release switch are combined.
FIG. 7 is a sectional view of the rear cylindrical portion (FIG. 5) taken along the line AA.
FIGS. 8A and 8B are a top view and a side view in a state where the rear cylindrical portion and the release switch are combined.
FIG. 9 is a schematic sectional view of a conventional needleless syringe.
[Explanation of symbols]
1, 21 ··· Nozzle 8, 28 ··· Rear cylinder part 1a, 21a ··· Injection hole 9, 29 ··· Screw part 2 ··· Chemical liquid amount display window 11 ··· Balls 3 and 23 · ··· Front cylinder part 12 ··· Latch grooves 4 and 24 ··· Piston 13 and 20 ··· Flange ring 4a ··· Seal member 14 ··· Ball receivers 5 and 25 ··· Piston rods 15 and 16 26: Compression springs 7, 27: Release switch 17: Small holes 7a, 7b: Convex part 18: Contact surface 8a, 8b: Concave part 22: Latch mechanism

Claims (1)

In a needleless syringe that presses a piston, which has been preliminarily urged forward in a latched state, at high speed into a drug solution inhaled from an injection hole of a nozzle, and injects the drug solution,
A front cylindrical portion incorporating a nozzle having an injection hole,
A concave portion provided in the longitudinal direction, which is screwed to the front cylindrical portion, and a concave portion provided in the end portion on the opposite side to the injection hole is provided in the circumferential direction in the rotational direction for connecting the longitudinal concave portion to suck the chemical solution. A rear cylindrical portion having a concave portion,
A ball receiver integrally provided on the rear cylindrical portion,
A plurality of balls in the ball receiver,
A latch groove through which each part of the ball enters and exits is provided, and a piston driving rod held in the rear cylindrical portion via the ball receiver in a state where the ball enters,
A convex portion inserted into the longitudinal concave portion or the circumferential concave portion of the rear cylindrical portion; and a contact surface provided to abut the ball when the ball is in the latch groove. And a release switch in which the convex portion is movable along the longitudinal concave portion and the circumferential concave portion with respect to the rear cylindrical portion,
A compression spring provided between the rear cylindrical portion and the release switch;
When the ball is not in the latch groove, the ball comes into contact with the contact surface and the release switch is held against the compression spring,
When the ball is inserted into the latch groove, the ball passes over the contact surface and contacts the contact surface to hold the piston driving rod, and the release switch is actuated by the urging force of the compression spring. The convex portion of the release switch is guided by the concave portion in the longitudinal direction, moves to the end of the concave portion, the ball receiver and the ball rotate, and the convex portion of the release switch passes through a contact surface that comes into contact with the ball receiver and the ball. Is inserted into the circumferential recess to prevent the pushing operation of the release switch.

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