CN101884813B

CN101884813B - Novel low-resistance injector

Info

Publication number: CN101884813B
Application number: CN2010102303763A
Authority: CN
Inventors: 余利荣
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-07-19
Filing date: 2010-07-19
Publication date: 2012-05-09
Anticipated expiration: 2030-07-19
Also published as: CN101884813A

Abstract

The invention relates to a improved low-resistance injector. The novel low-resistance injector comprises a syringe, a push rod and a rubber plug, wherein the push rod consists of a main body and a mounting head which is used for mounting the rubber plug; a cavity for accommodating the mounting head is reserved in the rubber plug; the cavity of the rubber plug has a big middle part and two small ends along the axial direction of the push rod; the diameters of the upper and lower heads of the mounting head are a little bigger than those of the two heads of the cavity; after the rubber plug is arranged on the push rod, space is reserved between the mounting head and the rubber plug in the axial direction, so that the rubber plug can slide backwards and forwards relative to the push rod along the axial direction of the push rod; the top part of the rubber top slightly arches upwards to form a hogback; two sealing rings are integrally formed on the outer circumference of the rubber plug; and the section of each sealing ring has a triangular shape, so that the four corners on the outside of the longitudinal section of the rubber plug have angular shapes. The injector adopts the structure and the frictional resistance is reduced to 0.05 Newton, so that the aims of low resistance and high sealing property are fulfilled. The practice shows that the low-resistance injector products have the advantages of simple production process, reject ratio lower than 1/10,000 and suitability for large-scale batch production.

Description

A kind of improved injection with low resistance

Technical field

The present invention relates to a kind of medical syringe, a kind of injection with low resistance of frictional resistance between particularly a kind of piston that can reduce the injector syringe inwall and slide within it.

Background technology

Syringe is that an indispensable apparatus is gone up in medical treatment, and especially in the anesthetic puncture field, known hard film external anesthetic puncture bag is also using glass syringe so far; Its injection cylinder is processed by glass, and the shortcoming of this glass syringe is broken easily in transportation, and push rod is because be frosted; Chips of glass cleans endless, and the copper core loses circle, will produce leakage; Cause of non-ideal use, if injection cylinder adopts other material substitution, in order to prevent the leakage around the piston; Obtain a good leakproof seal effect, piston must compress cylinder inboard wall, will influence sliding capability if the cylindrical shell and the piston magnitude of interference are excessive; Piston just is difficult in cylindrical shell, move freely, and the operator must just can make piston move with bigger power, and the little words of the magnitude of interference will seepage; Anesthetic puncture requires sliding capability below 0.2 newton, and how reducing between injector cartridge inwall and the piston that slides within it becomes a great problem that present syringe construction designs in the problem of the following frictional resistance of 0.2 newton.

Prior art makes and with lubricator reduces frictional resistance between piston and the cylinder inboard wall; A kind of lubricant that generally uses is silicone oil, but uses this lubricant and be out of favour, because this lubricant can disperse or is dissolved in the medicinal liquid; Thereby medicinal liquid is polluted; Therefore people once attempted exploring not with lubricator and syringe still can leakproof and method that piston is slided easily, and this trial comprises uses various piston profile, for example: be provided with one or more rib that in cylindrical shell, stretch out forward or backward on the piston; Reduce the purpose of frictional resistance therebetween so as to reducing contact surface between piston and cylinder inboard wall, reaching.And for example: Chinese patent 95193831.2 (publication number: CN1152882A; Open day: on June 25th, 1997) disclose a kind of " injection with low resistance "; The piston rod of this syringe can make the piston distortion; Its radial wall is drawn back from cylinder inboard wall, thereby reduce the friction between piston and the barrel, but these syringes all can not be with the tightness between automatic regulating piston of the variation of cylinder internal pressure and barrel; Can not effectively reduce the frictional resistance between piston and the barrel, not reach comparatively ideal effect.The name of inventor's application is called " injection with low resistance ", and (patent No.: 200510060714.2), this syringe is compared with existing syringe piston, and its sensitivity is higher; Cylinder internal pressure one changes; Sealing ring will squeeze to open and rise big or resilience is dwindled, and has both guaranteed sealing ring and injection cylinder inner wall sealing, has not leaked, reduce simultaneously again sealing ring because of be squeezed and the injection cylinder inwall between the frictional resistance that produces; Thereby reach the purpose of lower resistance, strong sealing; But this syringe is had relatively high expectations to mould and die accuracy, and vulcanization of rubber producting process difficulty is bigger, when frictional resistance 0.1 (newton) disqualification rate of product reach ten thousand/more than; Do not reach industry standard, can't produce in batches on a large scale.

Summary of the invention

Technical problem to be solved by this invention is: provide a kind of can be with the tightness between automatic regulating piston of the variation of cylinder internal pressure and barrel; Effectively reduce the frictional resistance between piston and the injection tube inwall, still can keep injection with low resistance simultaneously with the cylinder inboard wall sealing.

In order to solve above-mentioned technical problem, the present invention adopts following technical scheme:

A kind of improved injection with low resistance comprises syringe, push rod, plug, and push rod is made up of body and the installation head that is used to install plug; Be provided with the cavity that is used to hold installation head in the plug; It is characterized in that: it is little that the cavity of said plug is two broad in the middle along the push rod axial direction, and the somewhat larger in diameter at two is in the diameter at cavity two, after plug is installed on the push rod about the installation head; On axial direction, also leave the space between installation head and the plug; Plug can be along the push rod axial direction with respect to sliding before and after the push rod, slightly upwards arches upward and form a hogback in the plug top, and one-body molded on the outer circumference surface of said plug have a two seals ring; The cross section of sealing ring is roughly triangular in shape, makes four bights in the longitudinal section outside of plug all be tip-angled shape.

The height of said plug cavity also leaves the gap that plug slides a little more than the height of installation head between the installation head of push rod and the body.

The longitudinal section of said plug cavity is the little oval shape in two broad in the middle.

It is I-shaped that the longitudinal section of said installation head roughly is.

Two seals ring on the said plug outer circumference surface and syringe interference fit, the magnitude of interference is the 8-12 silk when static.

Adopt the syringe of this structure, on the one hand the contact surface between it and needle cylindrical unit inwall is less, and the contact surface between the opposing party it and needle cylindrical unit inwall can change with the change of needle cylindrical unit inner air pressure; Its sensitivity is higher; Cylinder internal pressure one changes, and plug will squeeze to open and rise big or resilience is dwindled, and has both guaranteed plug and needle cylindrical unit inner wall sealing, has not leaked; Reduce simultaneously again plug because of be squeezed and the syringe inwall between the frictional resistance that produces; Frictional resistance is reduced to 0.05 (newton), thereby reaches the purpose of lower resistance, strong sealing, and practice shows: this injection with low resistance product processes is simple; Disqualification rate less than ten thousand/, be suitable for producing in batches on a large scale.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the longitudinal cross-section view of plug;

Structural representation when Fig. 3 is the drawing liquid state;

Structural representation when Fig. 4 is inject state;

Fig. 5 is the structural representation of push rod.

The specific embodiment

Referring to Fig. 1; A kind of improved injection with low resistance comprises syringe (1), push rod (2), plug (3), and push rod (2) is made up of body and the installation head (211) that is used to install plug; Be provided with the cavity (311) that is used to hold installation head (211) in the plug (3); It is little that the cavity (311) of plug (3) is two broad in the middle along push rod (2) axial direction, referring to Fig. 2, can be known that by Fig. 2 the longitudinal section (along the push rod axial direction) of plug cavity (311) is the little oval shape in two broad in the middle.Installation head (211) up and down the somewhat larger in diameter at two in the diameter at cavity (311) two; After plug (3) is installed on the push rod; On axial direction, also leave the space between installation head (211) and the plug; Plug (3) can be along the push rod axial direction with respect to sliding before and after the push rod, and the height of plug cavity (311) also leaves the gap that plug slides a little more than the height of installation head (211) during design between installation head of push rod (211) and the body; Slightly upwards arch upward and form a hogback (4) in plug (3) top; One-body molded on the outer circumference surface of plug have a two seals ring (5,6), and the cross section of sealing ring is roughly triangular in shape, makes four bights in the outside, longitudinal section of plug (3) all be tip-angled shape (7).Two seals ring on the plug outer circumference surface (5,6) and syringe interference fit, the magnitude of interference is the 8-12 silk when static.

When resting state, plug (3) is a minima with the contact surface of syringe inwall, and its magnitude of interference is 10; The installation head (211) of push rod is positioned at the center (referring to Fig. 1) of plug (3) at this moment, and push rod post-tensioning during drawing liquid is under action of negative pressure; Plug (3) travels forward, and installation head (211) is positioned at the below (referring to Fig. 3) of plug (3), because that the cavity (311) of plug (3) is two broad in the middle along push rod (2) axial direction is little; The installation head of push rod (211) is pushed plug (3) from inside to outside, makes the contact surface of wedge angle (7) and syringe inwall of one sealing ring (6) below the plug strengthen, and the magnitude of interference of plug (3) increases; The magnitude of interference can reach more than 70, can prevent effectively that injection from leaking, with reducing of negative pressure value; Plug (3) moves backward; The plug resilience, and contact surface reduces between the needle cylindrical unit inwall, and the frictional resistance between the syringe inwall also reduces; Push away before the push rod during injection, under the effect of malleation, plug (3) moves backward; Installation head (211) is positioned at the top (referring to Fig. 4) of plug (3), and the installation head of push rod (211) is pushed plug from inside to outside, makes the contact surface of wedge angle (7) and needle cylinder wall of one sealing ring (5) above the plug strengthen; The magnitude of interference of plug increases, and the magnitude of interference can reach more than 70, and the hogback (4) of plug is also opened toward squeezing all around by straightening simultaneously; Further strengthen the wedge angle (7) of sealing ring and the contact surface of syringe inwall, reduce the plug resilience with the cylindrical shell inner air pressure; And contact surface reduces between the syringe inwall, and the frictional resistance between the syringe inwall reduces, and compares with existing syringe rubber plug with this kind plug; On the one hand the contact surface between it and needle cylindrical unit inwall is less, and the contact surface between the opposing party it and needle cylindrical unit inwall can change with the change of needle cylindrical unit inner air pressure, and its sensitivity is higher; Cylinder internal pressure one changes, and plug will squeeze to open and rise big or resilience is dwindled, and has both guaranteed plug and needle cylindrical unit inner wall sealing, has not leaked; Reduce simultaneously again plug because of be squeezed and the syringe inwall between the frictional resistance that produces, thereby should reach purpose of lower resistance, strong sealing.Experiment shows: the syringe initial force reaches 0.2N (cattle) minimum force 0.1N (cattle), mean force 0.15N (cattle).Syringe does not produce water droplet and leaks in 300Kpa hydraulic pressure (30 seconds).

Strengthen for the sensitivity that makes the plug adjusting of using as piston, the longitudinal section of installation head during design (211) roughly is I-shaped (referring to Fig. 5), makes the installation head (211) of push rod form and the corresponding apical ring of two seals ring (5,6) (8,9) at two up and down.

This kind syringe construction is simple, and cost of manufacture is low, and piston is easy in cylindrical shell, move, and good airproof performance is a kind of ideal injection with low resistance.

Claims

1. improved injection with low resistance; Comprise syringe (1), push rod (2), plug (3); Push rod (2) is made up of body and the installation head (211) that is used to install plug, is provided with the cavity (311) that is used to hold installation head (211) in the plug (3), and it is characterized in that: it is little that the cavity of said plug (311) is two broad in the middle along the push rod axial direction; Installation head (211) up and down the somewhat larger in diameter at two in the diameter at cavity two; After plug (3) is installed on the push rod, on axial direction, also leave the space between installation head (211) and the plug, plug can be along the push rod axial direction with respect to sliding before and after the push rod; Slightly upwards arch upward and form a hogback (4) in the plug top; One-body molded on the outer circumference surface of said plug have a two seals ring (5,6), and the cross section of sealing ring is roughly triangular in shape, makes four bights in the outside, longitudinal section of plug all be tip-angled shape.

2. a kind of improved injection with low resistance as claimed in claim 1 is characterized in that: the height of said plug cavity (311) also leaves the gap that plug slides a little more than the height of installation head (211) between the installation head of push rod and the body.

3. according to claim 1 or claim 2 a kind of improved injection with low resistance, it is characterized in that: the longitudinal section of said plug cavity (311) is the little oval shape in two broad in the middle.

4. according to claim 1 or claim 2 a kind of improved injection with low resistance, it is characterized in that: the longitudinal section of said installation head (211) roughly is I-shaped.

5. according to claim 1 or claim 2 a kind of improved injection with low resistance, it is characterized in that: two seals ring on the said plug outer circumference surface (5,6) and syringe interference fit, the magnitude of interference is the 8-12 silk when static.

6. according to claim 1 or claim 2 a kind of improved injection with low resistance, it is characterized in that: two seals ring on the said plug outer circumference surface (5,6) and syringe interference fit, the magnitude of interference is 10 when static.