JP2007268177A - Syringe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that fluid drips from an outlet part of an outer cylinder front end by a residual pressure generated in the fluid in the outer cylinder front part after pushing a plunger of a syringe. <P>SOLUTION: The plunger B is constituted of a body B<SB>1</SB>and a seal cylinder B<SB>2</SB>, the seal cylinder whose outer circumference is liquid-tightly and slidably fitted to an outer cylinder A is relatively movably fitted to the body, and an elastic projecting piece 21 projectingly provided in the internal circumference of the seal cylinder is fitted to the body. This syringe is so constituted that the elastic projecting piece is elastically deformed by the pushing of the plunger to advance the seal cylinder belatedly to the body and, when the pushing is released, the body is retreated from the seal cylinder by the elastic restoration force of the elastic projecting piece. <P>COPYRIGHT: (C)2008,JPO&INPIT

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 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 surface portion excluding the portion against elasticity, the other elastic material portion is extruded, and after a predetermined amount of fluid is extruded 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. In addition, a syringe that is easy to manufacture and easy to manufacture even during assembly and that can operate smoothly is proposed.

  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 of a main body and a seal cylinder.

  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. Moreover, the mounting recessed part for fitting a seal cylinder is provided in the outer periphery. The position where the mounting recess is provided is not particularly limited, but it is preferably provided in the front part. The length of the mounting recess in the axial direction correlates with the length of the seal cylinder in the axial direction, and is longer than the length of the seal cylinder as the seal cylinder moves. The front end surface of the mounting recess is configured to be in close contact with the front end surface of the seal tube, and the rear end surface is in close contact with the rear end surface of the seal tube. As a result, the front end surface of the seal tube is normally in close contact with the front end surface of the mounting recess, and the rear end surface becomes the rear end surface of the mounting recess when the seal tube moves rearward relative to the main body. It is configured so that it abuts closely.

  In addition, the rear end portion other than the mounting recess of the main body preferably has a light weight and small sliding friction so that the seal tube can be moved more smoothly and surely by an elastic protrusion described later. It is good to comprise so that the contact of the outer surface of the main body to the inner surface of the outer cylinder may be made by a plurality of linear surfaces forming the outer surface of the main body. Specifically, it has a configuration in which a plurality of plates project radially from the center of the rear portion of the mounting recess. In this case, the number of plates is two even if it is two (one in total). Although three or more may be used, three or more and five sheets are suitable for maintaining sliding stability in the outer cylinder. 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 part other than the mounting recessed part of a main body in a cylindrical shape.

  The seal cylinder has a cylindrical shape made of a flexible and elastic material such as elastomer, and the inner circumference is fitted to the tip of the mounting recess so that it can move relative to the rear of the main body. The outer periphery is fitted so as to be liquid-tightly slidable, and the elastic protrusion protruding from the inner periphery is fitted to the outer periphery of the main body so as to be elastically deformable.

  Then, the elastic projection piece is elastically deformed by the pushing of the plunger and the seal cylinder advances behind the main body, and when the plunger pushing is released, the elastic projection piece is elastically restored and the main body moves backward with respect to the seal cylinder. ing. In order to configure in this way, for example, the frictional force between the seal cylinder and the outer cylinder may be mainly formed so as to be greater than the frictional force between the seal cylinder and the main body and the elastic deformation of the elastic protrusion. In addition, it is considered that the elastic restoring force of the elastic protrusion is larger than the drag force such as the frictional force between the main body and the outer cylinder, and the main body can be moved to the rear end side.

  Various shapes can be adopted as the shape of the elastic protrusions as long as the above requirements are satisfied. For example, an elastic protrusion having a flange shape can be most preferably employed, and a plurality of protrusions can be annularly arranged. Further, as a means for fitting the elastic projection piece to the outer periphery of the main body so as to be elastically deformable, a concave groove is formed on the outer peripheral surface of the mounting concave portion of the main body, and the elastic projection piece is preferably fitted and fixed to the concave groove. In that case, in order to perform easier elastic deformation, it is good to provide the notch which spreads outward in the rear-end side opening edge part of a ditch | groove.

As a first means, there is provided an outer cylinder A provided with a pouring part 3 at the front end and a plunger B fitted so as to be able to be pushed into the outer cylinder A from the rear end, and the plunger B is an annular mounting recess 17. The inner periphery of the main body B ₁ and the front end of the mounting recess 17 are fitted to the inner circumference so as to be movable relative to the rear of the main body, and the outer circumference is fitted to the outer circumference of the outer cylinder A so as to be liquid-tightly slidable. In addition, the elastic projecting piece 21 projecting from the inner circumference is composed of a seal cylinder B ₂ fitted to the outer circumference of the main body B _{1 so as} to be elastically deformable, and the fluid is accommodated in the outer cylinder A portion in front of the plunger B. When the plunger B is pushed in from the state, the elastic protrusion 21 is elastically deformed, and the seal cylinder B ₂ moves forward after the main body B _{1. When} the plunger B is pushed open, the elastic protrusion 21 is elastically restored and the seal cylinder B ₂ is restored. In contrast, the main body B ₁ is configured to move backward.

As a second means, in the first means, the elastic protruding piece 21 forms a flange shape projecting inwardly from the inner surface of the seal cylinder B ₂ , and is recessed on the peripheral surface of the mounting recess 17. The annular groove 18 is provided, and a notch t extending outward is provided at the opening edge on the rear end side of the groove 18.

As a third means, in either of the first means or the second means, the mounting recess 17 is provided in the front portion of the main body B ₁ and the main body portion behind the mounting recess 17 is disposed on the radiation plate. As a shape, the outer surface of the main body B ₁ was brought into contact with the inner surface of the outer cylinder A on a plurality of linear surfaces f forming the outer surface of the main body B ₁ .

Since the tubular sealing B ₂ according to the present invention mated to a mounting recess 17 provided in the main body B ₁ periphery, the body B ₁ tip revealing the status matching the form of the outer cylinder A, such as rod portion 16 In addition, it is possible to reliably eliminate the residual pressure and prevent problems such as dripping. Further, the tubular sealing B ₂ is for a tubular, can be easily attached to the main body B _1, the assembly operation is easy.

The elastic protrusion 21, together form a flange which projects inwardly from the inner surface of the tubular sealing B _2, it is obtained by fitting the annular groove 18 which is recessed in the peripheral surface of the mounting recess 17, groove When the notch portion t spreading outward is provided at the rear end side opening edge portion of the 18, the seal tube B ₂ can be stably fitted into the main body B _{1 at a} predetermined position, and the notch portion t Therefore, the elastic protrusion 21 can be elastically deformed and restored without difficulty and has excellent durability.

Provided with the mounting recess 17 to the main body B ₁ front, a plurality of lines forming the main body B ₁ external surface contact of the body B ₁ the outer surface of the outer cylinder A the inner surface of the body portion of the rear as a radiation plate than the mounting recess 17 In the case of using the surface f, the contact surface between the inner surface of the outer cylinder A and the outer surface of the main body B ₁ can be narrowed to reduce the sliding resistance of the outer surface of the main body B _{1 with} respect to the outer cylinder A. The body B ₁ can be moved backward more easily.

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

  1 to 5 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 cylinder 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 core rod 14 protrudes forward from the central portion of the disk 13 at the front end of the cross-shaped cross section 12 and a small disk 15 having a smaller outer diameter than the disk 13 is attached to the front end of the core rod 14. The rod part 16 protrudes forward from the center front surface. The disk 13 and the small disk 15 at the front end of the cross-shaped cross section 12 form a mounting recess 17 between them, and the seal cylinder B ₂ is fitted into the mounting recess 17. In addition, an annular groove 18 is provided in an intermediate portion in the axial direction of the mounting recess 17. A notch t is provided at the opening edge on the rear end side of the groove 18 to widen the opening of the groove 18.

The seal cylinder B ₂ has a cylindrical shape in which the front and rear end portions of the outer peripheral surface protrude, and the protruding portion 21, which is the protruding portion, is slidably pressed on the inner periphery of the outer cylinder A so that the liquid-tightness of this portion is increased. Is maintained. Further, the inner peripheral surface is formed in a substantially same diameter from the front end to the rear end, the inner diameter thereof forms a slightly larger diameter than the outer diameter of the rod portion 16, the rear with respect to the main body B ₁ in the front end portion of the mounting recess 17 It is fitted so that relative movement to is possible. Therefore, the front end surface is in close contact with the rear surface of the small disk 15 which is the front surface of the mounting recess 17, and the rear end surface is provided with a gap d between the disk 13. Further, an annular elastic protruding piece 21 protrudes in the middle part in the front-rear direction along the axis of the inner peripheral surface, and the elastic protruding piece 21 is fitted in the mounting recess 17.

When the plunger B is pushed into the front end side of the outer cylinder A from the state of FIG. 1, the seal cylinder B ₂ is not easily slid by pressing the outer surface of the projecting portion 22 on the outer periphery against the inner surface of the outer cylinder A, and therefore shown in FIG. As described above, after the main body B ₁ is pushed toward the front end side while elastically deforming the elastic protruding piece 21, and the rear end surface of the seal cylinder B ₂ comes into contact with the front surface of the disc 13 which is the rear end surface of the mounting recess 17, the main body B ₁ After that, the fluid is pushed to the distal end side, and the fluid at the distal end portion in the outer cylinder A is discharged. When the pressure is released after release, the main body B ₁ moves to the rear end side due to the elastic restoring force of the elastic projection piece 21, and the rear surface of the small disc 15 which is the front end surface of the mounting recess 17 on the front end surface of the seal cylinder B ₂ Comes into contact with each other and the elastic protruding piece 21 returns to its 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 a principal part expanded sectional view of the seal cylinder fitting part of this invention syringe. 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 ... Picking part, 12 ... Cross section, 13 ... Disk, 14 ... Core bar, 15 ... Small disk,
16 ... Rod, 17 ... Mounting recess, 18 ... Groove, f ... Linear surface, t ... Notch,
B ₂ ... Seal cylinder d ... Clearance, 21 ... Elastic protrusion, 22 ... Projection

Claims (3)

A main body B ₁ having an outer cylinder A provided with a pouring part 3 at the front end 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 having an annular mounting recess 17 The inner periphery of the mounting recess 17 is fitted to the tip of the mounting recess 17 so that it can be moved relative to the rear of the main body, and the outer periphery of the outer cylinder A is fitted to the inner periphery of the outer cylinder A so as to be liquid-tightly slidable. It consists of a seal cylinder B _{2 in} which the provided elastic protrusion 21 is fitted to the outer periphery of the main body B _{1 so as} to be elastically deformable, and the plunger B is pushed in from the state in which the fluid is stored in the outer cylinder A part in front of the plunger B. Then, the elastic protrusion 21 is elastically deformed, and the seal cylinder B ₂ moves forward with a delay from the main body B ₁ , and the elastic protrusion 21 is elastically restored by pushing and releasing the plunger B, and the main body B _{1 with} respect to the seal cylinder B ₂ A syringe that is configured to retreat. The elastic protrusion 21, together forming a flange which projects inwardly from the inner surface of the tubular sealing B _2, is obtained by fitting the annular groove 18 which is recessed in the peripheral surface of the mounting recess 17, The syringe according to claim 1, wherein a notch t extending outward is provided at an opening edge on the rear end side of the groove 18. Provided with the mounting recess 17 to the main body B ₁ front, a plurality of lines forming the main body B ₁ external surface contact of the body B ₁ the outer surface of the outer cylinder A the inner surface of the body portion of the rear as a radiation plate than the mounting recess 17 The syringe according to claim 1 or 2, wherein the syringe is performed on the surface f.

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