CN102274562A

CN102274562A - Re-stroke safety injector

Info

Publication number: CN102274562A
Application number: CN2011101209078A
Authority: CN
Inventors: 张亚根
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-05-11
Filing date: 2011-05-11
Publication date: 2011-12-14

Abstract

The invention relates to a re-stroke safety injector which is composed of an outer tube, a rubber plug, a push rod and a core rod, wherein the core rod and the rubber plug are installed on the push rod, and can move up and down in the outer tube along with the push rod; and meanwhile, an ejection block on the push rod is corresponding to a pressing block on the core rod up and down. When in use, after finishing pushing the liquor and pulling out the injection needle, a blocky bulge on the push rod enters a slit between chock blocks on the outer tube, and the interactions can prevent the push rod from rotating relative to the outer tube; when the re-stroke needs to be started, the ejection block on the push rod and the pressing block on the core rod can be dislocated only by rotating the cap on the core rod, so that the core bar can continue to move downwards by one stroke (re-stroke) in the outer tube; and meanwhile, the post rod can move forwards in the inner bore of the cone head and protrude out of the inner bore of the cone head, and the injection needle connected to the cone head is ejected off, thereby implementing the expected functions of self-destruction and re-stroke of the injector.

Description

A kind of safety injector of stroke again

Technical field

The present invention relates to a kind of medical syringe tool; particularly a kind of safety injector of stroke again; be to ruin type, protection respectively respectively, provide simultaneously depleted syringe (not contacted blood and do not have bio-toxicity) the possible a kind of leading theory of recycling is designed a kind of instrument used for injection for satisfying entry needle and syringe.

Background technology

A kind of safety injector of stroke more of the present invention mainly is meant the instrument used for injection that is used for medical purpose, and it relates to our various syringes used in everyday.Syringe is the container and the injection tool that medicinal liquid can be drawn in its inner chamber, and injects (puncture) pin, then is to puncture and set up the instrument of medicinal liquid infusion channel to the injection site.The two cooperates the common function of injection of realizing medicinal liquid.They are bringing into play enormous function in the process of human clinic diagnosis disease.It is indispensable treatment utensil.But, along with the variation of nature advancing of disease with virus, antibacterial, cross infection and the pathophoresis that takes place with blood or body fluid contact is on the rise, and (as: drug addict is to the common or repeated use of instrument used for injection, cause the bamboo telegraph of disease, be exactly in addition in daily medical act, entry needle is also very serious to the nosocomial infection of medical personnel's pricking wound initiation, even causes transmissions of disease such as AIDS, hepatitis B, hepatitis C).The disposable strict demand of instrument used for injection has been risen to the laws and regulations requirement of various countries.And The World Health Organization (WHO) has also strictly regulated the safety injection three elements: 1, harmless to user; 2, harmless to receiver (patient); 3, environmental sound; At present, clinical use be mostly ordinary syringe or passive security syringe, finish medicine is expelled to the intravital purpose of people after, can not realize the automatically damaging shape (exist reusable may) of syringe or by pulling back push rod and it is fractureed and passive unmaking (increase operating procedure), and entry needle can not be hidden the risk that medical personnel or waste disposal personnel are stabbed in existence after use; For this reason; the scientific worker has carried out number of research projects; the technical scheme of a large amount of safety injectors is disclosed; but majority exists such or such deficiency; promoting the use of of safety injector is severely limited, and the paces that present safety injector is promoted the use of at home are very slow.Surplus Patent Office of the People's Republic of China disclosed 200 in part safety injector patent; the overwhelming majority utilizes the latch structure of injector push-rod front end; medicinal liquid inject finish after; dependency structure interlocking with injecting needle base; form to connect, again with manual type with the entry needle pull from moving back, in the indentation syringe cylinder, protecting; and then injector push-rod implemented manual fractureing, syringe is unmake.Its deficiency is:

1, when use returns the entry needle pull to the protection scheme of syringe urceolus, to note constantly and push rod can not be pressed to the end in the process of taking out medicine and eliminating gas of syringe before injection, otherwise will make syringe that self-destruction takes place before treatment, and can not realize its predetermined work;

2, complex structure, it is alternative to cause different safety injector parts not exchange mutually, has increased enterprise's manufacturing cost;

3, because structural deficiency, make product use habit and clinical injection rule of operation inconsistent, make the operation sequence increase, use loaded down with trivial detailsly, medical personnel can not accept, and product is out of favour etc.

More than all multifactor, all cause above-mentioned safety injector product on market, to be difficult to promote and promote situation slowly.The safety self-destruct product of China's disposable medical instrument used for injection is interfered on using and promoting, and country and enterprise are difficult to existing resources is fully effectively used on safe and reliable, good and cheap, easy to manufacture, as to meet clinical medical and nursing injection operation routine and the use habit disposible safety syringe tool.

In addition, we know: in depleted syringe and entry needle, entry needle is because be to have contacted patients'blood and body fluid, belong to high-risk Biohazard Waste Disposal, syringe then is the medicine dissolving device tool, in use only contacts with medicinal liquid, belong to general Biohazard Waste Disposal, have domestic expert in academic report, to point out---molten medicinal Biohazard Waste Disposal, through practical observation for many years, do not find that so far there is harm in its material aspect recycling; We are also through inquiring into fully and demonstration, think: every not contacted patient blood, after the Biohazard Waste Disposal of body fluid and bio-toxicity (specially referring to molten pharmaceutical injection device and transfusion device at this) are being ruined type, its raw material be present in the possibility that downstream industry utilizes once more (though, country's policy is not in this respect also decontroled), be example only with depleted infusion medicine dissolving device tool, the garbage in China every year always weighs 100,000 tons more than, and mostly these material are a high level dead meal, if these dead meals are used in building material industry again, annual can production reaches 200,000 tons sewer pipe, 4,000,000,000 economic worth can be created, 40,000 job opportunities can be directly created.This is a huge social business opportunity, meets the theory of energy-saving and environmental protection, also is a road that moves towards low carbon development.

For this reason; we have proposed the protection theory respectively of entry needle and syringe, will abandon exactly existingly to protect the wrong theory of entry needle with syringe, when entry needle is protected conscientiously; molten medicinal syringe is freed, make it to have the possibility that to recycle once more.

I disclose the technical scheme of the safe injection needle of a kind of disposable safety injector with active self-destroying function that can satisfy above-mentioned requirements and active self-destroying function in the CN101099876A patent; but its syringe is owing to only there is the stroke design again; and do not have the secondary re-journey structure, so the protection of easy erroneous trigger safe injection needle action when injection liquid finishes.

I also disclose the another kind of disposable safety injector with secondary re-journey that can satisfy above-mentioned requirements in the CN101357245A patent; the technical program has typically stroke structural design again; can avoid the mistake of secondary re-journey action to take place, be to solve aspect syringe and the entry needle safeguard protection technical scheme preferably.

At this a kind of safety injector of stroke again propose to be proposed, the one, can solve the deficiency of each technical scheme except that the CN101357245A patent, simultaneously, also propose one and different with the CN101357245A patent structure can solve above-mentioned various insufficient technical scheme.Being also advantageous in that of the technical program:

● meet the specific (special) requirements of advanced theory that entry needle and syringe protect respectively for syringe.

● the structure of syringe will be simpler.

● be more conducive to industrialized production and implement.

The scheme that the present invention proposes is to break through the brand-new scheme of existing public technology; novelty and practicality with essence; be to satisfy entry needle and syringe to ruin type, the leading instrument used for injection of a kind of theory of protection respectively respectively, also have simultaneously make up simplify, simple to operate, characteristics that reliability is high and easy to manufacture.

Summary of the invention

A kind of safety injector of stroke more of the present invention is made up of urceolus, plug, push rod and core bar.Wherein: core bar and plug all are installed on the push rod, and place the inner chamber of urceolus.

Urceolus is that the upper end has crimping, there is the cylinder-like body that satisfies international standard ISO 594-1:1986 conehead the lower end, wherein, be evenly distributed with on the interior edge of crimping quantity more than 2, to projecting inward block, block is that triangle and bottom are orthogonal combination 5 limit shapes on the top that is projected as towards axis direction, the plane curvature sum of all blocks is not more than 360 °, and the plane curvature of arbitrary block is not more than 90 °, between any two blocks vertical clearance gap is arranged all, and the width in this slit is greater than the width of the block-shaped protrusion on the push rod; The internal diameter of the block on the urceolus is slightly larger than the ejector sleeve external diameter on the push rod, and less than the outer diameter of the block-shaped protrusion on the push rod.

Plug is that the upper end has big circular open, and the center has torus space, bottom to hit exactly foraminous cylinder, and the torus space of its center can hold the baffle plate on the push rod and closely cooperate with it, and the diameter in the hole of bottom is slightly less than the diameter of the push rod on the core bar.

Push rod is made up of the block-shaped protrusion on the boss on top and jacking block, the middle part ejector sleeve and the baffle plate of bottom.The boss on push rod top is an annular, its external diameter is slightly less than the internal diameter that protects the edge on the core bar, the upper surface of boss has several along circumference jacking block evenly that arrange, protruding upward, quantity, the planar dimension (containing the position) and highly identical of the briquetting on the quantity of jacking block, planar dimension (containing the position) and height and the core bar, wherein the height of jacking block equals the length of the stroke again of expected design, space between any two jacking blocks all can hold a briquetting on the core bar, in the center, upper surface of jacking block the groove that points to axis direction is arranged; The epimere of the ejector sleeve at push rod middle part have outwardly directed, evenly arrange along circumference, quantity is no less than 2 block-shaped protrusion, block-shaped protrusion is that rectangle and bottom are the combination 5 limit shapes of del on the top that is projected as towards the push rod axis direction, its orthogonal height is greater than the height of the block on the urceolus, and the outside diameter of block-shaped protrusion is less than the internal diameter of urceolus.

Core bar is made up of the block on top, the cross at middle part and the push rod of bottom.The block on core bar top has circular top plate, top board edge to have the circle of stretching out to protect the medicated cap shape on edge downwards on being, wherein, there is successive teeth groove in the outside of protecting the edge in circle, the bottom face that protects the edge in circle has the button platform that inwardly stretches out, be provided with the second button platform identical with detaining platform in the place apart from the height of a button platform upper surface briquetting (or be equivalent on the push rod a jacking block height), the inner edge diameter of button platform is less than the boss external diameter on the push rod; Have in the top board inboard of block that several are evenly arranged around the center of circle, protrude downwards briquetting, at the stupefied muscle of the oriented lower convexity in the center of briquetting, and suitable with size, direction, the position of groove on the jacking block; The outer diameter of the cross at core bar middle part is less than the ejector sleeve internal diameter of push rod; The median pore diameter of the slightly larger in diameter of the push rod of core bar bottom on plug is less than the internal orifice dimension of the conehead on the urceolus.

When a kind of safety injector of stroke more of the present invention dispatches from the factory, core bar is plugged in the push rod, jacking block on the push rod is corresponding with the briquetting on the core bar, the stupefied muscle on the briquetting enters in the groove on the jacking block, button platform on the core bar and the boss on the push rod are interlocked, at this moment, on the core bar distance of the ejector sleeve inner bottom surface of the lower surface of cross to the push rod greater than the height of jacking block; Plug is contained on the baffle plate on the push rod, and place the interior space of urceolus, when plug contacts with the inner bottom surface of urceolus, push rod on the core bar is in the conehead endoporus on the urceolus, block-shaped protrusion on the push rod just in time enters between the block on the urceolus, make push rod must not do turn with respect to urceolus, if turn core bar, then briquetting on the core bar and the relative position between the jacking block on the push rod will change and until dislocation, at this moment, core bar can be done once more with respect to the moving downward of urceolus (promptly stroke) again, simultaneously, push rod on the core bar also will continue forward (in order to entry needle is evaded from the conehead of syringe, thereby finishing the separation of pin device) in the interior space of conehead; And when the block-shaped protrusion on the push rod not with urceolus on block when interacting, push rod then not only can move up and down with core bar, can also promptly between push rod and the core bar relative turn can not take place with the core bar turn.

In the use, when medicinal liquid inject finish and pull out entry needle after, the block-shaped protrusion on the push rod will enter between the block on the urceolus automatically; When needs start the stroke function again, only need hold block on the core bar and make it to produce turn with respect to urceolus, because block-shaped protrusion on the push rod and the interaction between the block on the urceolus, make push rod keep motionless with urceolus, turn along with core bar, briquetting on it and the relative position between the jacking block on the push rod will change, and until dislocation, at this moment, core bar can be done to give prominence to outside cone head hole (promptly stroke) again with respect to the push rod on the core bar of moving downward and make of urceolus once more.

Like this, just finished the function of stroke again of expected design, simultaneously also owing to the boss on the push rod will fasten with the second button platform on the core bar after carrying out stroke again, thereby cause using syringe later when plug contact urceolus inner bottom surface, the push rod on the core bar must be given prominence to outside cone head hole, that is to say, the syringe of this moment can not be loaded onto entry needle, so, make that the syringe after discarding can not be reused once more, and realized the safety self-destruct function of expected design.

Owing to adopted technique scheme, make the present invention satisfy the design philosophy that the device pin separates, unmakes respectively, make the structure of active self-destroyed syringe that the variation of essence take place, under the situation that does not change clinical use habit, realized the active design of the safety self-destruct of syringe.The structural design of stroke more particularly of the present invention has broken through the technical scheme of all existing safety injectors.A kind of safety injector of stroke more of the present invention, its safety is higher, and is easy to use, and meets clinical use working specification.

A kind of safety injector of stroke more of the present invention, because the design philosophy that has adopted the device pin to separate, unmake respectively, the expected design of the satisfied recycling of the syringe after the use (because: syringe has only contacted medicinal liquid in clinical), meet the life idea that circulation is beneficial to again.So application of the present invention meets the national policy of energy-saving and emission-reduction.The recycling of instrument used for injection will be a wealth leaving society for.

Description of drawings

Fig. 1 is that structure of the present invention is launched sketch map.

Fig. 2 is the combinative structure of the present invention sketch map of (when not starting again the stroke function) before use.

Fig. 3 is the sketch map of combinative structure of the present invention (after starting again the stroke function) after the use.

The specific embodiment

Fig. 1 is that structure of the present invention is launched sketch map, by this figure as can be known: the present invention is by urceolus 1, plug 2, push rod 3 and core bar 4 are formed, wherein: urceolus 1 has crimping 1a for the upper end, there is the cylinder-like body that satisfies international standard ISO 594-1:1986 conehead the lower end, wherein, be evenly distributed with quantity on the interior edge of crimping 1a more than 2, to projecting inward block 1b, block 1b is that triangle and bottom are orthogonal combination 5 limit shapes on the top that is projected as towards urceolus 1 axis direction, the plane curvature sum of all block 1b is not more than 360 °, and the plane curvature of arbitrary block 1b is not more than 90 °, between any two block 1b vertical clearance gap is arranged all, and the width in this slit is greater than the width of the block-shaped protrusion 3b on the push rod 3; The internal diameter of block 1b on the urceolus 1 is slightly larger than the ejector sleeve external diameter on the push rod 3, and less than the outer diameter of the block-shaped protrusion 3b on the push rod 3.

Plug 2 is big circular open for the upper end has, the center has torus space, bottom to hit exactly the cylinder of porose 2a, the torus space of its center can hold the baffle plate 3a on the push rod 3 and closely cooperate with it, and the diameter of the hole 2a of bottom is slightly less than the diameter of the push rod 4a on the core bar 4.

Push rod 3 is made up of the block-shaped protrusion 3b on the boss 3c on top and jacking block 3d, the middle part ejector sleeve and the baffle plate 3a of bottom.The boss 3c on push rod 3 tops is an annular, its external diameter is slightly less than the internal diameter along 4c1 of protecting of block 4c on the core bar 4, the upper surface of boss 3c on the push rod 3 has several evenly to arrange along circumference, jacking block 3d protruding upward, the quantity of jacking block 3d, the quantity of briquetting 4d on planar dimension (containing the position) and height and the core bar 4, planar dimension (containing the position) is with highly identical, wherein the height of jacking block 3d equals the length of the stroke again of expected design, space between any two jacking block 3d all can hold a briquetting 4d on the core bar 4, in the center, upper surface of jacking block 3d the groove 3d1 that points to axis direction is arranged; The epimere of the ejector sleeve at push rod 3 middle parts have outwardly directed, evenly arrange along circumference, quantity is no less than 2 block-shaped protrusion 3b, block-shaped protrusion 3b is that rectangle and bottom are the combination 5 limit shapes of del on the top that is projected as towards push rod 3 axis directions, its orthogonal height is greater than the height of the block 1b on the urceolus 1, and the outside diameter of block-shaped protrusion 3b is less than the internal diameter of urceolus 1.

Core bar 4 is made up of the block 4c on top, the cross 4b at middle part and the push rod 4a of bottom.The block 4c on core bar 4 tops has on being circular top plate, top board limit to have the circle of stretching out to protect medicated cap shape along 4c1 downwards, wherein, protecting in circle has successive teeth groove 4c2 along the outside of 4c1, protecting along the bottom face of 4c1 in circle has the button platform 4e that inwardly stretches out, be provided with the second button platform 4e1 identical with detaining platform 4e in the place that is equivalent to a briquetting 4d height (or the height of a jacking block 3d on the suitable push rod 3) apart from button platform 4e upper surface, the inner edge diameter of button platform 4e is less than the boss 3c external diameter on the push rod 3; Have in the top board inboard of block 4c that several are evenly arranged around the center of circle, protrude downwards briquetting 4d, at the stupefied muscle 4d1 of the oriented lower convexity in the center of briquetting 4d, and suitable with size, direction, the position of groove 3d1 on the jacking block 3d of push rod 3.The outer diameter of the cross 4b at core bar 4 middle parts is less than the ejector sleeve internal diameter of push rod 3; The diameter of the hole 2a of the slightly larger in diameter of the push rod 4a of core bar 4 bottoms on plug 2 is less than the internal orifice dimension of the conehead on the urceolus 1.

Fig. 2 is the combinative structure of the present invention sketch map of (when not starting again the stroke function) before use, by this figure as can be known: core bar 4 is plugged on the push rod 3, briquetting 4d on the core bar 4 is corresponding with the jacking block 3d on the push rod 3, and, stupefied muscle 4d1 on the briquetting 4d enters in the space of the groove 3d1 on the jacking block 3d, button platform 4e on the core bar 4 and the boss 3c on the push rod 3 fasten, and the minimum range of the inner bottom surface of the ejector sleeve of the lower surface of the cross 4b on the core bar 4 to the push rod 3 is greater than the height of the jacking block 3d on the push rod 3; Plug 2 is installed on the baffle plate 3a on the push rod 3, and is placed in the interior space of urceolus 1, and when plug 2 did not contact with the inner bottom surface of urceolus 1, the assembly of plug 2, push rod 3 and core bar 4 can freely-movable together in the interior space of urceolus 1; When plug 2 contacts with the inner bottom surface of urceolus 1, block-shaped protrusion 3b on the push rod 3 will enter in the vertical clearance gap between the block 1b on the urceolus 1 automatically, and can interact with block 1b, make the push rod 3 must not be in the interior space turn of urceolus 1, simultaneously, the push rod 4a on the core bar 4 will enter in the conehead endoporus on the urceolus 1.

Fig. 3 is the sketch map of combinative structure of the present invention (after starting again the stroke function) after the use, by this figure as can be known: medicinal liquid inject finish and pull out entry needle after, at this moment, block-shaped protrusion 3b on the push rod 3 has entered in the slit between the block 1b on the urceolus 1, and can interact with the block 1b on the urceolus 1 and stop the turn of push rod 3 with respect to urceolus 1; When needs start the stroke function again, only need hold block 4c on the core bar 4 and make it to produce turn with respect to urceolus 1, turn power will overcome groove 3d1 on the jacking block 3d and the mutual resistance between the stupefied muscle 4d1 on the briquetting 4d, make core bar 4 relative push rods 3 that turn take place, between jacking block 3d and briquetting 4d, misplace, then, promoting core bar 4 downwards makes it continue to move downward the stroke (promptly stroke) again of a jacking block 3d with respect to urceolus 1, the second button platform 4e1 on boss 3c on the push rod 3 and core bar 4 fastens, simultaneously, push rod 4a also will continue in the space downwards in the conehead of urceolus 1 and stretch out from the endoporus of conehead, the entry needle that will be connected simultaneously on the conehead pushes away from urceolus 1, thereby finishes separating of entry needle and syringe.

Like this; the realization of the function of stroke again by syringe; the self-destruction protection of syringe itself, the disengaging of entry needle and the expected design that the entry needle safeguard protection starts have been finished; wherein; the startup of stroke function has clear and legible course of action again; and can avoid the false triggering of stroke function again, have higher safety, be to be different from the brand-new technology scheme of known technology now.

Claims

1. a stroke safety injector again is made up of urceolus (1), plug (2), push rod (3) and core bar (4), and wherein plug (2) and core bar (4) all are installed on the push rod (3), and are placed in the interior space of urceolus (1), it is characterized in that:

Urceolus (1) has crimping (1a) for the upper end, and there is the cylinder-like body that satisfies international standard ISO 594-1:1986 conehead the lower end, be evenly distributed with on the interior edge of crimping (1a) quantity more than 2, to projecting inward block (1b);

Plug (2) is big circular open for the upper end has, and there is the cylinder of torus space, center, bottom porose (2a) center;

Push rod (3) is made up of the block-shaped protrusion (3b) on the boss (3c) on top and jacking block (3d), the middle part ejector sleeve and the baffle plate (3a) of bottom; The boss (3c) on push rod (3) top is an annular, its upper surface has several along circumference jacking block (3d) evenly that arrange, protruding upward, the height of jacking block (3d) equals the length of the stroke again of expected design, in center, the upper surface of jacking block (3d) groove (3d1) that points to axis direction is arranged, the epimere of the ejector sleeve at push rod (3) middle part have outwardly directed, evenly arrange along circumference, quantity is no less than 2 block-shaped protrusion (3b);

Core bar (4) is made up of the block (4c) on top, the cross (4b) at middle part and the push rod (4a) of bottom; The block (4c) on core bar (4) top has circular top plate on being, the top board limit has the circle of stretching out to protect the medicated cap shape on edge (4c1) downwards, wherein, there are several evenly to arrange in the top board inboard of block (4c) around the center of circle, protrude downwards briquetting (4d), stupefied muscle (4d1) at the oriented lower convexity in center of briquetting (4d), there is successive teeth groove (4c2) in the outside of protecting edge (4c1) in circle, the bottom face that protects edge (4c1) in circle has the button platform (4e) that inwardly stretches out, and is equivalent to a briquetting (4d) in distance button platform (4e) upper surface and highly is provided with the second button platform (4e1) identical with detaining platform (4e) in the place of (or the height of a jacking block 3d on the suitable push rod (3)).

2. according to claim 1: the block (1b) on the urceolus (1) is that triangle and bottom are orthogonal combination 5 limit shapes on the top that is projected as towards urceolus (1) axis direction, the plane curvature sum of all blocks (1b) is not more than 360 °, and the plane curvature of arbitrary block (1b) is not more than 90 °, between any two blocks (1b) vertical clearance gap is arranged all, and the width in this slit is greater than the width of the block-shaped protrusion (3b) on the push rod (3); The internal diameter of the block (1b) on the urceolus (1) is slightly larger than the ejector sleeve external diameter on the push rod (3), and less than the outer diameter of the block-shaped protrusion (3b) on the push rod (3).

3. according to claim 1: the torus space on the plug (2) can hold the baffle plate (3a) on the push rod (3) and closely cooperate with it, and the diameter of the hole of bottom (2a) is slightly less than the diameter of the push rod (4a) on the core bar (4).

4. according to claim 1: the external diameter of the boss (3c) on the push rod (3) is slightly less than the internal diameter that protects edge (4c1) on the core bar (4), quantity, the planar dimension (containing the position) and highly identical of the briquetting (4d) on the quantity of the jacking block (3d) on the boss (3c), planar dimension (containing the position) and height and the core bar (4), and the space between any two jacking blocks (3d) all can hold the briquetting (4d) on the core bar (4); Block-shaped protrusion (3b) on the push rod (3) is that rectangle and bottom are the combination 5 limit shapes of del on the top that is projected as towards push rod (3) axis direction, its orthogonal height is greater than the height of the block (1b) on the urceolus (1), and the outside diameter of block-shaped protrusion (3b) is less than the internal diameter of urceolus (1).

5. according to claim 1: the stupefied muscle (4d1) of the oriented lower convexity in center of the briquetting (4d) on the core bar (4), and suitable with size, direction, the position of groove (3d1) on the jacking block (3d) of push rod (3), the outer diameter of the cross (4b) at core bar (4) middle part is less than the ejector sleeve internal diameter of push rod (3); The slightly larger in diameter of the push rod (4a) of core bar (4) bottom is in hole (2a) diameter on the plug (2) and less than the internal orifice dimension of the conehead on the urceolus (1); The inner edge diameter of button platform (4e) is less than boss (3c) external diameter on the push rod (3).

6. according to claim 1, claim 4 and claim 5: when the position between the jacking block (3d) on the briquetting (4d) on the core bar (4) and the push rod (3) is in when relative, the button platform (4e) on the core bar (4) can fasten with the boss (3c) on the push rod (3); When the briquetting (4d) on the core bar (4) and the position between the jacking block (3d) on the push rod (3) are in when interlacing, the button platform of second on the core bar (4) (4e1) can fasten with the boss (3c) on the push rod (3).

7. according to claim 1, claim 4 and claim 5: when the position between the jacking block (3d) on the briquetting (4d) on the core bar (4) and the push rod (3) is in when relative, stupefied muscle (4d1) on the core bar (4) enters in the groove (3d1) on the push rod (3), and, the minimum range of the inner bottom surface of the ejector sleeve of the lower surface of the cross (4b) on the core bar (4) to the push rod (3) is greater than the height of the jacking block (3d) on the push rod (3), at this moment, relative motion can promptly can not take place between push rod (3) and the core bar (4) with core bar (4) motion in push rod (3).

8. according to claim 1, claim 2, claim 3, claim 4 and claim 5: a kind of safety injector of stroke more of the present invention medicinal liquid inject finish and pull out entry needle after, be that plug (2) is when contacting with the inner bottom surface of urceolus (1), block-shaped protrusion (3b) on the push rod (3) will enter in the slit between the block (1b) on the urceolus (1) automatically, and prevention push rod (3) is done the turn with respect to urceolus (1), simultaneously, the push rod (4a) of core bar (4) bottom will enter in the internal orifice dimension of the conehead on the urceolus (1).

9. according to claim 1, claim 2, claim 3, claim 4, claim 5 and claim 8: when after injection finishes, needing to start again the stroke function, only need by the block (4c) on the turn core bar (4), make between briquetting (4d) on the core bar (4) and the jacking block (3d) on the push rod (3) by original relative position, change the phase wrong position into, thereby can make the combined altitudes of briquetting (4d) and jacking block (3d) be converted into closed state by original overlap condition, can be so that core bar (4) continues to move downward a stroke that is equivalent to jacking block (3d) height on the push rod (3) (promptly stroke) again with respect to urceolus (1), simultaneously, push rod (4a) on the core bar (4) will continue to move downward in the internal orifice dimension of the conehead on the urceolus (1), and stretch out downwards from the internal orifice dimension of conehead.