JP4640247B2 - Needleless syringe - Google Patents

Description

  The present invention relates to a needleless syringe that performs subcutaneous injection by jetting a chemical solution sucked from an injection hole of a nozzle or a chemical solution previously filled in a nozzle.

  A needleless syringe is a syringe that injects a drug solution into the patient's skin by jetting the drug solution in the nozzle sucked from the injection hole at the tip of the needle or the drug solution previously filled in the nozzle from the injection hole. . In other words, injection with a needleless syringe does not use an injection needle at the time of subcutaneous injection, so there are advantages such as prevention of needle stick accidents and use for patients with acrophobia. In addition, when used by pregnant women, the effects of sound on the fetus and sound in public places must be taken into account.

  The structure of a conventional needleless syringe is shown in FIG. (A) is a top view of a needleless syringe, (B) is AA sectional drawing in the state after injection. This needleless syringe is provided with a nozzle 1 having an injection hole 1a at the tip, and a front cylindrical portion 2 having an injection amount display window 2a for displaying the injection amount of the medicine sucked backward, and a piston 3 at the front end. And a piston rod 7 that is fixed to the rear of the flange ring 4 and that is movable back and forth through a compression spring 6 disposed between the flange ring 4 and the flange 5, and a latch. A latch mechanism 9 comprising a latch ball receiver 9 containing a ball 8, a groove 7 a formed on the circumference of the piston rod 7 and a latch release button 10, and the latch ball receiver 9 are fixed, and a screw portion 13 serves as a front cylinder. The rear cylindrical portion 12 is formed by screwing the portion 2 and inserting the latch release button 10 from the rear.

When the rear cylindrical portion 12 of the needleless syringe is turned and pushed into the front cylindrical portion 2, the latch ball 8 moves forward in conjunction with the latch ball receiver 9, and reaches the groove portion 7a of the piston rod 7. At the same time, the opposite side of the latch ball 8 is pressed by the inner peripheral surface of the front end of the latch release button 10, and the piston rod 7 is connected (latched) to the rear cylindrical portion 12. At this time, the flange ring 4 is assembled at a reference position and the scale number of the injection amount display window 2a is set to 0 in advance. In this state, for example, a needle-less syringe is inserted in the suction port of a drug solution vial (not shown). When the injection hole 1a is applied and the rear cylindrical portion 12 is rotated in the opposite direction, the required amount of the chemical can be sucked. Next, the injection amount is set, the injection hole 1a of the nozzle 1 is applied to the injection site, and the latch release button 10 is pushed. The chemical solution is injected by releasing the latch.
JP 2001-079906 A

Although the conventional needleless syringe is configured as described above, the instant latch ball 8 pops out of the groove 7a and injects the drug solution and collides with the inner surface of the latch release button 10 as shown in FIG. There is a concern that a shocking sound will be generated, and if the person receiving the injection is a pregnant woman, it will adversely affect the mind and body of the fetus.
This invention is made | formed in view of such a situation, Comprising: It aims at providing the needleless syringe with a small generated sound at the time of injection.

In order to achieve the above object, a needleless syringe according to the present invention is a needleless syringe which performs a subcutaneous injection by jetting a liquid medicine from an injection hole by advancing a piston rod provided with a ball groove into which a latch ball fits at a high speed. A latch ball that fits into the ball groove of the piston rod and latches the piston rod, a pressing surface that engages with the latch ball fitted into the ball groove, and a contact surface that the latch ball pops out by releasing the latch. A latch release button and a biasing means for biasing the latch release button with respect to the syringe body, and the latch release button is fitted in the ball groove in a state of being biased by the biasing means. When the pressing surface engages with the latch ball and the latch release button is pressed against the biasing force of the biasing means, the latch Latch is released engaged between the ball and the pressing surface is disengaged, the latch ball is configured to impinge on the contact surface, the contact surface is formed by an impact cushioning material.
The needleless syringe of the present invention is configured as described above, and can reduce the sound generated during injection.

  According to the present invention, sound generated at the time of injection with a needleless syringe is reduced, and adverse effects on the fetus when using a pregnant woman can be reduced. Moreover, even if it is used in a public place, it is easy to use because the generated sound is reduced.

  Hereinafter, the needleless syringe of the present invention will be described in detail by way of examples. FIG. 1 is a side sectional view (A) of a needleless syringe of the present invention before inhalation of a drug solution and an enlarged view (B) of its latch mechanism, and FIG. In the drawing, except for the structure of the latch release button 10, it is configured in the same manner as the conventional needleless syringe shown in FIG. 4, and the same reference numerals are given to those components.

  As shown in FIG. 1 (A), this needleless syringe is fitted with a nozzle 1 in which an injection hole 1a for injecting a chemical liquid by the movement of an inserted piston 3 is arranged in the center of the front end, and a chemical liquid in the rear. The front cylindrical portion 2 that opens the injection amount display window 2a for displaying the injection amount, the latch mechanism that latches the piston rod 7 that drives the piston 3, and the latch release that releases the piston rod 7 and releases it at high speed. A rear cylindrical portion 12 in which the button 11 is provided is screwed by a screw portion 13, and a flange ring 4 is integrally fixed to the piston rod 7, and is provided in connection with the flange ring 4 and the rotary bearing 14. A compression spring 6 is interposed between the flanges 5 and a piston rod 7 is disposed therethrough.

  As shown in FIG. 1B, the latch mechanism is fixed to the rear cylindrical portion 12 and has a plurality of small holes 9a formed so that the latch balls 8 can move perpendicularly to the axial direction. 9, the groove 7a formed on the circumference of the piston rod 7 one turn, the ball retainer 16 in which the retaining surface 16a for latching the latch ball 8 is formed in the groove 7a, and the latch ball 8 coming out from the groove 7a. A latch release button 11 integrally connected with a cylindrical cushion member 15 formed with a contact surface 15a to be enabled, and a latch ball release 9 and a ball presser 16 are interposed between the latch release button 11 and the latch release button 11. It is comprised from the compression spring 17 which gives power. The cushion member 15 may be made of a soft resin such as rubber or silicone that is used as an impact buffer material or formed directly on the latch release button 11 by an integral molding method.

  Next, the movement of the latch ball 8 during a series of operations from drug solution inhalation to injection by the needleless syringe will be described with reference to FIGS. The needleless syringe shown in FIG. 1 is in a state before inhaling a drug solution, that is, in a state where the piston rod 7 is latched by the rear cylindrical portion 12 and the flange ring 4 is pressed forward. At this time, a part of the latch ball 8 is fitted into the groove 7a of the piston rod 7, and the opposite side is in contact with the pressing surface 16a. In this state, the injection hole 1a of the syringe is pressed against the drug solution vial and the rear cylindrical portion 12 is moved backward to inject a predetermined drug solution amount. Then, when the injection hole 1a is applied to the injection site, the latch release button 11 is pushed in and the pressing surface 16a moves forward from the latch ball 8, the piston rod 7 moves forward at a high speed by the extension force of the compression spring 6. At this moment, each latch ball 8 is pushed by the rising surface of the groove 7a of the piston rod 7 and pushed out along the inclined surface 16b of the ball presser 16 and hits the contact surface 15a of the cushion member 15 as shown in FIG. It stops in the space surrounded by the rod 7 and the contact surface 15a. This operation is performed at high speed, and a large impact force is applied to the inner surface of the cushion member 15, but this impact force is absorbed by the cushion member 15, and the impact sound generated at this time is reduced.

  FIG. 3 shows a rear sectional view of the needle-free injection using a latch release button 11A which is a modification of the lock release button 11. As shown in FIG. The latch release button 11 </ b> A is configured using a cushion member 18 made of the same material as the cushion member 15, the ball presser 16, and a cylindrical ball presser 19. Thereby, since the inclined surface 16b is formed by the cushion member 18 which is an impact buffering material, the impact force of the latch ball 8 is weakened by both the inclined surface 18a and the contact surface 18b. It can be attenuated more than the case, and the impact sound at that time is also reduced.

  It is used for a needleless syringe that performs a subcutaneous injection by jetting a certain amount of a chemical solution sucked from an injection hole of a nozzle or a chemical solution previously filled in the nozzle, and in particular, a needleless syringe that lowers the generated sound during injection.

It is side surface sectional drawing (A) before the chemical | medical solution inhalation of the needleless syringe by the Example of this invention, and the enlarged view (B) of the latch mechanism part. It is side surface sectional drawing of the needleless syringe rear part after chemical | medical solution injection. It is the rear sectional view (A) of the needleless syringe concerning other examples, and the side view (B) shown with the partial section of the cushion member. It is the top view (A) and side sectional view (B) which show the composition of the conventional needleless syringe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle 1a Injection hole 2 Front side cylindrical part 2a Injection amount display window 3 Piston 4 Flange ring 5 Flange 6, 17 Compression spring 7 Piston rod 7a Groove part 8 Latch ball 9 Latch ball receiving 9a Small hole 10, 11, 11A Latch release button 12 Rear cylindrical portion 13 Threaded portion 14 Rotating bearing 15, 18 Cushion member 15a, 18b Contact surface 16, 19 Ball presser 16a Presser surface 16b, 18a Inclined surface

Claims (1)

In a needleless syringe that performs a subcutaneous injection by jetting a liquid medicine from an injection hole by advancing a piston rod provided with a ball groove into which a latch ball is fitted at high speed, the piston rod is fitted into the ball groove of the piston rod A latch ball for latching, a pressing surface engaged with the latch ball fitted in the ball groove, a latch release button having a contact surface on which the latch ball pops out by releasing the latch, and the latch release button on the syringe body An urging means for urging the latch, and the press release surface engages the latch ball fitted in the ball groove in a state where the latch release button is urged by the urging means, and the latch release button When pressed against the urging force of the urging means, the latch ball and the presser surface are disengaged and the latch is released. Is, the latch ball is configured to impinge on the contact surface, needleless syringe, characterized in that said contact surface is formed by an impact cushioning material.

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