JP4902245B2 - Syringe - Google Patents

Description

  The present invention relates to a syringe used in dentistry.

A syringe is known in which a plunger is fitted into an outer cylinder having a dispensing part protruding from the front end, and the fluid in the outer cylinder can be dispensed from the dispensing part by pushing the plunger. When the fluid is discharged from the part, residual fluid is generated in the fluid in the outer cylinder part in front of the plunger because the outlet hole of the outlet part is a narrow hole, so that the outlet is also discharged even after the plunger has been pushed. A small amount of fluid flowed out from the holes and dropped to contaminate the periphery. In order to eliminate such drawbacks, the rod-shaped portion protrudes forward from the front end of the plunger, and the front end portion of the rod-shaped portion is wrapped in a piston shape with an elastic material. After extruding forward against the outer circumference and the rear part excluding the part against elasticity, the other elastic material part is extruded, and after a predetermined amount of fluid is pushed out from the nozzle, the extrusion of the plunger is stopped, There is known a syringe provided so that the elastic material front portion pushed out by the front surface of the rod-like portion is elastically restored, and the residual pressure of the fluid is eliminated by expanding the fluid storage chamber when the plunger is retracted by the elastic restoration. ing. (See Patent Document 1)
JP 2004-24768 A

  In the case of the above conventional example, it is excellent that liquid dripping from the pouring hole can be prevented by eliminating the residual pressure, but the tip end surface of the piston-like portion that wraps the tip of the rod-like portion protruding from the tip of the plunger is elastic. Since it is configured to be deformed, the shape of the plunger tip is significantly limited. For example, the diameter of the dispensing portion at the tip of the outer cylinder is reduced for efficient discharge of the liquid, and the plunger tip is also correspondingly reduced in diameter. It is difficult to form the rod portion, and there is a disadvantage that the liquid in the portion with the reduced diameter cannot be discharged.

  The present invention has been made in view of the above points, and proposes a syringe that can cope with the form of the plunger regardless of the form of the outer cylinder and can also surely eliminate the residual pressure.

  The syringe of the present invention includes an outer cylinder and a plunger. The outer cylinder is formed of a synthetic resin or the like, and a known form having a pour-out portion at the tip can be used. The plunger is for pressing the fluid in the outer cylinder and pouring out from the pouring part, and is formed from a main body and a seal member.

  The main body is formed of a synthetic resin or the like, and the rear end protrudes outward from the rear end of the outer cylinder and is attached to the outer cylinder so that it can be pushed. Further, a mounting projection for fitting the seal member is provided at the tip. The length of the mounting projection in the axial direction correlates with the length of the seal member in the axial direction, and the projecting surface of the mounting projection is configured to provide a predetermined gap with a rear surface of a brake ring described later of the seal member. . In addition, it is preferable to provide an air vent groove on the outer surface of the mounting projection. One or a plurality of grooves may be provided, and when the seal member is fitted, the seal member can be smoothly expanded and contracted without containing air between the seal member and the mounting projection.

  Further, it is preferable that the rear end portion of the main body other than the mounting projection is made lighter and less slidable so that the seal member can be moved more smoothly and reliably by the telescopic cylinder portion described later. For this purpose, it is preferable to form the radiating plate so that the outer surface of the main body contacts the inner surface of the outer cylinder with a plurality of linear surfaces forming the outer surface of the main body. Specifically, it is a form in which a plurality of plates project radially from the center of the rear portion of the mounting projection, and in this case, the number of plates may be two or three or more. However, in order to maintain the sliding stability in the outer cylinder, three or more and about five are appropriate. Further, in order to further improve the sliding stability, it is preferable to form a disc integrally in the direction orthogonal to the axial direction. And let the outer surface of these radiation | emission plate-shaped parts and a disk be a linear surface. In addition, it is also possible to form the rear end portion other than the mounting projection of the main body in a cylindrical shape.

  The seal member is made of a flexible and elastic material such as elastomer, and is fitted to the mounting protrusion. It has a brake ring, a telescopic cylinder, and a front plate, which are formed integrally. Is done. The brake ring has an inner peripheral surface fitted to the rear outer periphery of the fitting projection so as not to slip out, and an outer peripheral surface is fitted to the inner peripheral surface of the outer cylinder so as to be liquid-tightly slidable. The inner peripheral portion can be fitted by forming a rearward stepped portion or an annular groove on the fitting projection and fitting the inner peripheral portion on the stepped portion back surface or the annular groove.

  The telescopic cylinder part is extended by pressing the front plate by the fitting projection, and is a cylindrical shape that is fitted to the outer periphery of the mounting projection by connecting the rear end part to the peripheral edge of the brake ring and the rear edge part of the front plate at the front end part. It is configured. The outer surface of the telescopic cylinder part is preferably provided with a gap between the outer cylinder.

  The front plate has a rear surface in contact with the front surface of the mounting projection, and an outer peripheral surface thereof is preferably fitted to the inner periphery of the outer cylinder so as to be capable of liquid-tight sliding in order to advance and retreat in the outer cylinder stably. In addition, when the outer cylinder has a configuration in which the tip portion has a reduced diameter portion, a rod portion that fits into the reduced diameter portion may be provided so as to protrude from the front surface in accordance with the configuration.

Then, after the telescopic cylinder part is extended by pushing the plunger and the front plate advances, the brake ring advances behind the main body while maintaining the extended state of the telescopic cylinder part, and when the plunger is released, the telescopic cylinder part is released. Is constructed so that the main body moves backward with respect to the brake ring. In order to configure in this way, basically, the frictional force between the brake ring and the outer cylinder is larger than the frictional force between the front plate and the main body and the elastic extension of the telescopic cylinder part. In addition, considering the elastic restoring force of the telescopic cylinder part to be larger than the drag force such as the friction force between the main body and the outer cylinder and the friction force between the front plate and the outer cylinder, the front plate 23, the brake ring 21 and the outer cylinder diameter of the tube a, or the thickness of the extension sleeve 22, to select the material of the sealing member B _2.

As a first means, an outer cylinder A having a reduced diameter part 5 at the front end and a pouring part 3 at the front end of the reduced diameter part 5 and a plunger B fitted so as to be able to be pushed into the outer cylinder A from the rear end. The plunger B includes a main body B ₁ having a mounting projection 14 at the tip, and a seal member B ₂ fitted to the mounting projection 14, and the seal member B ₂ has a mounting projection A brake ring 21 having an inner periphery fitted to the outer periphery of the rear portion 14 so as to prevent slipping out, and an outer peripheral surface fitted to the outer periphery of the outer cylinder A so as to be liquid-tightly slidable. while integrally extended to an elastic stretchability is extendable tube portion 22, thereby connecting the peripheral portion integrally with the front end of the telescopic tube unit 22, abuts the rear face to the mounting projection 14 front and , and a front plate 23 a rod portion 24 projecting from the front surface center that fits the reduced diameter portion 5, like that has housed the fluid into the barrel a portion of the front plunger B From Engaging plunger B, extension sleeve portion 22 while maintaining the extended state of the telescopic cylinder portion 22 behind the main body B ₁ in the braking ring 21 is advanced after the front plate 23 moves forward extended, pushing the plunger B The telescopic cylinder portion 22 is elastically restored by opening and the main body B ₁ is retracted with respect to the brake ring 21.

As a second means, in the first means, the main body portion rearward from the mounting projection 14 is shaped like a radiation plate, and the outer surface of the main body B ₁ is brought into contact with the inner surface of the outer cylinder A to form the outer surface of the main body B _1. The test was performed on a plurality of linear surfaces f.

  As a third means, an air vent groove 15 is provided on the outer surface of the mounting projection 14 in the first means or the second means.

Since the seal member B ₂ according to the present invention is fitted in as the elastic tubular portion 22 at the outer periphery of the mounting projecting portion 14 projecting from the main body B ₁ tip expands and contracts, the plunger B tip In addition to being able to reveal the situation according to the form of the outer cylinder A such as the rod portion 24, the residual pressure can be surely eliminated, and inconvenience such as dripping can be prevented.

When the main body portion behind the mounting projection 14 is shaped like a radiating plate and the outer surface of the main body B ₁ is brought into contact with the inner surface of the outer cylinder A with a plurality of linear surfaces f forming the outer surface of the main body B ₁ , narrowing the contact surface between the cylinder a the inner surface and the main body B ₁ the outer surface can reduce the sliding resistance of the main body B ₁ the outer surface to the outer tube a, the rearward movement of the main body B ₁ due to the elastic restoring force of the stretchable tubular portion 22 more easily Yes.

In the case where the air venting groove 15 is provided on the outer surface of the mounting projection 14, air is supplied between the seal member and the mounting projection 14 through the groove 15 when the telescopic cylinder portion 22 expands and contracts. Thus, there is an advantage that the expansion and contraction operation of the seal member B ₂ can be performed more smoothly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 4 show an example of the syringe of the present invention, in which 1 denotes the syringe. The syringe 1 includes an outer cylinder A and a plunger B.

  The outer cylinder A is provided with a finger-hanging outward flange 2 at the rear end, and the front end portion is a pouring portion 3, and the pouring portion 4 projects the pouring needle 4. The distal end portion of the outer cylinder A is a reduced diameter portion 5 that is reduced in diameter to approximately the same diameter as a rod portion described later.

The plunger B includes a main body B ₁ and a seal member B ₂ and is fitted so as to be able to be pushed into the outer cylinder A. The main body B ₁ is provided with a knob 11 at the rear end thereof with the outer peripheral portion protruding outward in a flange shape. Further, the portion excluding the front end portion of the main body B _{1 has} a cross-shaped cross section 12, and the cross-shaped cross section 12 is divided into three equal parts in the front-rear direction, and is substantially the same as the inner diameter of the outer cylinder A at each end of each section. An outer diameter disk 13 is attached. The outer surface of the cross-shaped cross section 12 and the outer surface of each disk 13 and the inner surface of the outer cylinder A are contacted by a plurality of linear surfaces f.

A mounting projection 14 projects from the front surface of the disk 13 at the front end of the cross-shaped cross section 12, and the sealing member B ₂ is fitted into the mounting projection 14. The mounting projection 14 has a form in which the front half is formed into a cylindrical large-diameter portion 14a and the rear half is formed into a cylindrical small-diameter portion 14b. Further, a plurality of air venting grooves 15 extending from the outer surface of the large diameter portion 14a through the rear surface of the large diameter portion 14a to the outer surface of the small diameter portion 14b are formed in the circumferential direction. The groove 15 is intended to prevent air from accumulating between the seal member B ₂ when fitting the sealing member B ₂ and the mounting projection 14, also described later of the seal member B ₂ This is because the expansion / contraction of the expansion / contraction cylinder portion can be performed more smoothly.

Sealing member B ₂ is obtained by forming a synthetic rubber, and a braking ring 21, an extension sleeve 22, and a front plate 23. The brake ring 21 abuts the front center edge on the rear surface of the large-diameter portion 14a and prevents the forward movement by fitting the inner peripheral surface to the outer periphery of the distal end portion of the small-diameter portion 14b. The cylinder A is fitted to the inner periphery of the cylinder A so as to be liquid-tightly slidable. The telescopic cylinder portion 22 has a thin cylindrical shape fitted around the large-diameter portion 14a, and is integrally extended forward from the peripheral portion of the brake ring 21 and configured to be elastically extensible. . The front plate 23 has a disc shape and has an outer peripheral surface fitted on the inner periphery of the outer cylinder A so as to be capable of liquid-tight sliding, and maintains the liquid-tightness of this portion. Further, the rear surface is in contact with the front surface of the mounting projection 14, and the peripheral edge portion is integrally connected to the tip of the telescopic cylinder portion 22. A bar portion 24 is integrally projected from the front center of the front plate 23.

When the plunger B is pushed into the distal end side of the outer cylinder A from the state of FIG. 1, the brake ring 21 of the seal member B ₂ is not easily slid by pressing the outer surface against the inner surface of the outer cylinder A. As shown in FIG. The telescopic cylinder portion 22 extends and the front plate 23 advances. Braking rings 21 behind the main body B ₁ advance after extension sleeve portion 22 of the front plate 23 while maintaining the extended state when the partitioned extension is advanced. At these times, the fluid at the tip in the outer cylinder is released. When the pressure is released after the release, the main body B ₁ moves to the rear end side due to the elastic restoring force of the expansion / contraction cylinder part 22, and the expansion / contraction cylinder part 22 and the front plate 23 return to the original state. At that time, the residual pressure of the fluid in the front end portion of the outer cylinder A can be eliminated. Sequential discharge is performed, and finally the entire storage fluid can be discharged as shown in FIG.

It is sectional drawing of this invention syringe. Example 1 It is sectional drawing along the XX line of FIG. Example 1 It is sectional drawing of the plunger pushing state of this invention syringe. Example 1 It is sectional drawing which shows the state which pushed the plunger of this invention syringe to the front limit. Example 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Syringe A ... Outer cylinder 2 ... Outward flange, 3 ... Dispensing part, 4 ... Dispensing needle, 5 ... Reduced diameter part,
B ... Plunger
B ₁ … Body
11 ... pick part, 12 ... cross-shaped cross section, 13 ... disc, 14 ... projection for mounting, 14a ... large diameter part,
14b ... small diameter part, 15 ... groove, f ... linear surface,
B ₂ ... Seal member
21 ... brake ring, 22 ... telescopic cylinder, 23 ... front plate, 24 ... bar

Claims (3)

An outer cylinder (A) having a distal end portion as a reduced diameter portion (5) and an extraction portion (3) provided at the distal end of the reduced diameter portion (5) and a rear end portion that can be pushed into the outer cylinder (A). The plunger (B) includes a main body (B ₁ ) having a mounting projection (14) at the tip, and a seal member (B) fitted to the mounting projection (14). ₂ ), and the seal member (B ₂ ) is fitted on the inner periphery of the mounting projection (14) so as not to slip out on the outer periphery of the mounting projection (14), and is liquid-tight on the inner periphery of the outer tube (A). A brake ring (21) with an outer peripheral surface movably fitted thereto, a telescopic cylinder part (22) that extends from the periphery of the brake ring (21) to the front and elastically expands and contracts, and expands and contracts The peripheral portion is integrally connected to the tip of the cylindrical portion (22), the rear surface is brought into contact with the front surface of the mounting projection (14) , and the rod portion (24) fitted to the reduced diameter portion (5) is disposed on the front surface. It was projecting from the center When the plunger (B) is pushed in from the state in which the fluid is housed in the outer cylinder (A) portion in front of the plunger (B), the telescopic cylinder part (22) expands and the front plate The brake ring (21) advances behind the main body (B ₁ ) while maintaining the extended state of the telescopic cylinder part (22) after the forward movement of (23), and the telescopic cylinder part (22 ) Is elastically restored and the main body (B ₁ ) moves backward with respect to the brake ring (21). A plurality of linear surfaces that form the outer surface of the main body (B ₁ ) by making the main body portion rearward from the mounting projection (14) into a radial plate shape and contacting the outer surface of the main body (B ₁ ) to the inner surface of the outer cylinder (A) ( The syringe according to claim 1, which is performed in f).   The syringe according to claim 1 or 2, wherein a groove (15) for bleeding air is provided on the outer surface of the mounting projection (14).

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