CN105214181B - Safety injector and its needle body needle stand pumpback device - Google Patents

Abstract

The present invention discloses a kind of safety injector and its needle body needle stand pumpback device, and safety injector mainly includes a cylinder, a pushing piece, a pumpback part and a syringe needle group；The cylinder is in hollow cylindrical body and is respectively provided with a syringe needle group installation end and an operation holding end, and form a barrel chamber in the inner barrel, it is set in the barrel chamber to the pushing piece pullable, and form a pushrod chamber in the inside of the pushing piece, the pumpback part airtight can slippingly be set to the pushrod chamber, which is correspondingly arranged in the syringe needle group installation end；The present invention can make the inside of the pushing piece form vacuum state, and after the completion of injection, enter the discarded syringe needle group pumpback after use in the pushrod chamber by the pull of vacuum inside the pushing piece, to achieve the purpose that the safe disposal syringe by the pumpback part.

Description

Safety injector and its needle body needle stand pumpback device

Technical field

The present invention relates to a kind of medical supplies more particularly to a kind of safety injectors.

Background technology

Clinically used syringe has healthcare givers's contaminated needle sticks accidentally often in time set needle cover, and leads Cause needle prick infection accident, syringe usually after use, needle body must all return set needle cover after, and according to regulation lose into Collecting vessel concentrates destruction, occurs again to avoid similar situation.

In order to improve the safety problem that existing syringe uses, inventor's hammer away has simultaneously been applied diversified and innovation Injector designed by the construction of inner barrel, can enter used needle body pumpback to inner barrel after injection Harvesting to reduce the chance that user touches pollution needle body, and then reduces psychology of the medical staff when using syringe and fears Fear.

However, inventor is still unsatisfactory for the utilization of the prior art, still persistently exert one's heart and strength to the utmost to be dedicated to safety injection Device is technical to progress greatly, and developmental research can simplify internal structure and technique and increase safety in utilization, stabilization with great concentration Property, the innovative techniques of smoothness, and then medical technology is made to be promoted to higher boundary.

Invention content

The present invention is in order to propose that internal structure is more simplified, and the easily fabricated medication injections handled with operating with Device, and be to pass through pumpback it is a primary object of the present invention to provide a kind of safety injector and its needle body needle stand pumpback device Part causes the pushing piece positioned at inner barrel that can form extremely low air pressure space, the effect transmitted by external atmospheric pressure come Pumpback syringe needle group promotes the safety used and achievees the purpose that simplify structure manufacture simultaneously.

The present invention with technological means be to provide a kind of safety injector, including：

One cylinder is a hollow cylindrical body, and is located at the Large Diameter Pipeline section front end with a Large Diameter Pipeline section and one and is formed The pipe with small pipe diameter section of gradually-reducing shape, one end that the pipe with small pipe diameter section is connected in the Large Diameter Pipeline section of the cylinder are defined as a syringe needle group installation end, And reversely one end far from the syringe needle group installation end is defined as an operation holding end, and one is then formed in the inside of the Large Diameter Pipeline section Chamber is formed with a blocking bulge loop in the ring wall projection that the syringe needle group installation end is adjacent in the barrel chamber；

One pushing piece airtight can slippingly be set to the barrel chamber of the cylinder, and include：

There is one movable push bar a hollow pushrod chamber, one can slide in the barrel chamber and interior caliber is in slightly reducing The medicament push end of shape and one extend to the operating side outside the barrel chamber；

Airtight stopper in one is airtightly equipped in the pushrod chamber at medicament push end；

One outer gas crammed plug, with the medicament of the movable push bar push end and this interior airtight stopper is mutually airtight engages, and It can airtightly slide in the barrel chamber；

One end cap is fastened in the operating side of the movable push bar, and shields and sustain pipe by end cap central is perforative with one；

One pumpback part, can the airtight pushrod chamber for being slippingly set to the movable push bar, which includes a drawing Bar and an airtight plug sleeve, the drawing are pierced by outside the pushrod chamber with a holding end by the pipe of shielding and sustain of the end cap, and with a reversed fixing End engages the airtight plug sleeve and stretches into the pushrod chamber, and the airtight plug sleeve is made to fit in the interior airtight stopper；

One syringe needle group corresponds to and is installed on the syringe needle group installation end of the cylinder, and includes a needle body, one is sheathed on the needle The needle stand of external side and one needle stand retainer ring on the outside of the needle stand is sheathed on, which is set to the barrel chamber of the syringe needle group installation end It is interior, and shielded and sustain in the pipe with small pipe diameter section with front end, which is sticked in the blocking bulge loop in the Large Diameter Pipeline section, the needle The rear end of seat forms a fitting portion, which is incorporated into airtight gear in the pushing piece with the corresponding and concave-convex blocking of the fitting portion Plug；

The pumpback part, in airtightly pulling back displacement in the movable push bar, removes this by the airtight plug sleeve and pushes away by the pull rod Air in rod cavity, and the rear end of the movable push bar is equipped in, make to form an extremely low air pressure space inside the movable push bar, and in After the completion of medicament injection, push the needle stand retainer ring of the syringe needle group forward by the pushing piece, the needle stand retainer ring is made to be detached from the needle The blocking bulge loop of seat and the cylinder enables the needle stand and the interior airtight stopper synchronize and move into the movable push bar, and by the external world The interior airtight stopper is combined atmospheric pressure the needle stand and the needle body is pushed into the movable push bar, uses generation safety, returns automatically The effect of drawn needle body.

The present invention with technological means be to provide the needle body needle stand pumpback device of safety injector a kind of, including：

One pushing piece in the barrel chamber of a cylinder that airtight can be slippingly set to a syringe, and includes one Movable push bar, airtight stopper, an outer gas crammed plug and an end cap in one；Wherein, the movable push bar have a hollow pushrod chamber, One can slide in the barrel chamber and interior caliber in the medicament push end for slightly reducing shape and one extends to the operating side outside the barrel chamber, The interior airtight stopper is airtightly equipped in the pushrod chamber at medicament push end, the medicament of the outer gas crammed plug and the movable push bar End and the interior mutually airtight engaging of airtight stopper are pushed, and can airtightly be slid in the barrel chamber, which is fastened in the work The operating side of dynamic push rod, and with one pipe is shielded and sustain by end cap central is perforative；

One pumpback part, can the airtight pushrod chamber for being slippingly set to the movable push bar, which includes a drawing Bar and an airtight plug sleeve, the pull rod are pierced by outside the pushrod chamber with a holding end by the pipe of shielding and sustain of the end cap, and with a reversed card Fixed end engages the airtight plug sleeve and stretches into the pushrod chamber, and the airtight plug sleeve is made to fit in the interior airtight stopper.

Aforementioned safety injector and its needle body needle stand pumpback device, wherein the front end face canyon topography of the interior airtight stopper Cheng Youyi is in the needle stand connecting portion of groove body pattern, and the fitting portion of the needle stand is in step shape and is formed in the rear end of the needle stand Portion, and the fitting portion corresponds to the needle stand connecting portion and is in the hitching post build formula protruded.

Aforementioned safety injector and its needle body needle stand pumpback device, the front end of the wherein interior airtight stopper forward-facing protrudes out A needle stand connecting portion in circle hitching post build formula is formed with, and the fitting portion of the needle stand is corresponding to the needle stand connecting portion and in rear end Portion is formed in groove body.

A barrel chamber for being through to the Large Diameter Pipeline section is formed in the pipe with small pipe diameter section of aforementioned safety injector, the wherein cylinder Needle body stretches out hole and the rear ring wall formation in needle body stretching hole shields and sustain hole greater diameter than the needle stand in needle body stretching hole, And in the needle body stretch out hole and the needle stand shield and sustain the adjacent ring wall in hole be formed with one can for the needle stand front-end edge against against Terrace edge.

Aforementioned safety injector, the wherein needle stand shield and sustain neighbouring be somebody's turn to do against terrace edge in hole front end and be formed with one for the needle stand position The drag reduction spacing of shifting.

In aforementioned safety injector and its needle body needle stand pumpback device, the wherein pushrod chamber end is pushed in the neighbouring medicament Ring wall on be formed with one first snap ring.

In the ring of the neighbouring operating side in aforementioned safety injector and its needle body needle stand pumpback device, the wherein pushrod chamber One second snap ring is formed on wall.

Aforementioned safety injector and its needle body needle stand pumpback device, the wherein interior airtight stopper are in the column block of step shape And plug together portion and a plug slot with a protrusion, one, the protrusion and the portion of plugging together be located at the interior airtight stopper respectively before, Back segment, the diameter of the protrusion are less than the diameter for plugging together portion, which is formed in the front end face center of the protrusion Place, which, which falls into, is formed in the rear end face centre for plugging together portion, which, which surround, is recessed with an annular groove, This plugs together the first snap ring that portion is equipped in the movable push bar with annular groove correspondence, and the protrusion is airtight to be sticked in medicament push end Internal perisporium.

The medicament push end of aforementioned safety injector and its needle body needle stand pumpback device, the wherein movable push bar forms one Ring sleeve portion, the outer gas crammed plug correspond to seal sleeve and airtight can be slid together in the ring sleeve portion and the protrusion of the interior airtight stopper In in the barrel chamber of the cylinder, and can be against the rear end face for the needle stand retainer ring for fitting in the syringe needle group.

Aforementioned safety injector and its needle body needle stand pumpback device, wherein the outer gas crammed plug of the pushing piece and the medicament It pushes end airtight joint and corresponds to protrusion of the seal sleeve together in the interior airtight stopper, and can airtightly slide in the cylinder In barrel chamber.

The medicament push end of aforementioned safety injector and its needle body needle stand pumpback device, the wherein movable push bar forms one Screw part, and the outer gas crammed plug and the screw part are airtight screws togather and the corresponding airtight protrusion for being sticked in the interior airtight stopper, And it can airtightly slide in the barrel chamber of the cylinder.

Aforementioned safety injector and its needle body needle stand pumpback device, wherein, the internal perisporium in medicament push end is surround An inner ring is convexly equipped with, the periphery wall of the protrusion of the interior airtight stopper is around a concave ring groove is equipped with, and the protrusion is with the concave ring groove The corresponding and airtight inner ring at medicament push end for being sticked in the movable push bar.

The medicament push end of aforementioned safety injector and its needle body needle stand pumpback device, the wherein movable push bar forms one Screw part, and the outer gas crammed plug and the medicament push end are airtight screws togather and the corresponding airtight protrusion for being sticked in the interior airtight stopper Portion, and can airtightly slide in the barrel chamber of the cylinder, and the protrusion of the interior airtight stopper plugs together portion with this and can decompose Section is plugged together, and can mutually screw togather and be integrated and form the interior airtight stopper for a convex section and one, the periphery wall of the convex section Outer gas crammed plug is airtight engages, and its front end face forms the needle stand connecting portion with this, and end face forms a screw part thereafter；This is plugged together Section front end face corresponds to the screw part of the convex section and forms a spiro union portion, and can be integrated with the close spiral shell of the screw part, outside Around an annular groove is recessed with, this plugs together section and corresponds to airtight the first snap ring for being equipped in the pushrod chamber with the annular groove peripheral wall.

Aforementioned safety injector and its needle body needle stand pumpback device, the wherein pull rod of the pumpback part are formed with more for periphery The long rod of a rib, both ends are respectively the block end and the holding end, which is located at the front end of the pull rod and is equipped with Multiple fixing bulge loops being arranged at intervals and be surrounded on the pull rod, the holding end are located at the rear end of the pull rod and are pierced by the end cap, The pull rod is equipped with a recess notch at the neighbouring fixing bulge loop rear, which forms the point of application that the pull rod fractures.

Aforementioned safety injector and its needle body needle stand pumpback device, wherein the fixing bulge loop of the pull rod and the recess notch Between be equipped with one be in overhead kick shape blocking ring edge, and form a locking edge, the pull rod in the port ring wall for shielding and sustain pipe of the end cap Blocking ring edge can correspond to and be snapped in the locking edge.

Aforementioned safety injector and its needle body needle stand pumpback device, wherein the pumpback part should by pull rod block end engaging Airtight plug sleeve, and pulled back by the holding end and move the pumpback part, the blocking ring edge of the pull rod is made to be locked to the locking edge of the end cap, And in the vacuum attraction energy that an extremely low air pressure space is generated in the pushrod chamber.

Aforementioned safety injector and its needle body needle stand pumpback device, wherein the pumpback part should by pull rod block end engaging Airtight plug sleeve, and pulled back by the holding end and move the pumpback part, the airtight plug sleeve is made to be equipped in the second card of the push rod cavity rear end Ring, and in the vacuum attraction energy that an extremely low air pressure space is generated in the pushrod chamber.

The present invention moves displacement by movable push bar pulled rearward of the pumpback part in pushing piece, and pushrod chamber is removed by pumpback part Interior air, and the rear end of pushing piece is equipped in, make to form an extremely low air pressure space inside movable push bar, and what formation one prestored Pull of vacuum, and the needle stand of syringe needle group is pushed further along by after the completion of medicament push injection in cylinder by pushing piece Retainer ring makes needle stand retainer ring be detached from the blocking bulge loop of needle stand and cylinder, enables pin base fastener together in interior airtight stopper and synchronization-sliding Enter in pushrod chamber, and by pushrod chamber outside atmospheric pressure push, needle stand and the needle body of fixation is made to merge the interior airtight stopper and synchronize Into in pushrod chamber, to generate the effect in the automatic pumpback to movable push bar of needle body that will be used, polluted, reach preventive inoculation The purpose of thorn, also, close to achieve the effect that chimeric and detach by the easy structure of concave-convex opposite blocking between each component, it is real Simplify the construction inside syringe in matter, and also simplify the flow manufactured, quite with practical value.

Below in conjunction with the drawings and specific embodiments, the present invention will be described in detail, but not as a limitation of the invention.

Description of the drawings

The appearance diagram of the first preferred embodiment of Fig. 1 present invention；

The decomposition diagram of the first preferred embodiment of Fig. 2 present invention；

The usage state diagram of the pulling pull rod of the first preferred embodiment of Fig. 3 A present invention；

The usage state diagram of the pull rod that fractures of the first preferred embodiment of Fig. 3 B present invention；

The usage state diagram that liquid is extracted using pushing piece of the first preferred embodiment of Fig. 4 A present invention；

The usage state diagram using pushing piece liquid medicine injection of the first preferred embodiment of Fig. 4 B present invention；

The pushing pushing piece of the first preferred embodiment of Fig. 5 A present invention and the usage state diagram for pushing needle stand retainer ring；

The usage state diagram that the needle stand of the first preferred embodiment of Fig. 5 B present invention is released with all blockings of needle stand retainer ring；

Needle body, needle stand and the interior airtight stopper of the first preferred embodiment of Fig. 6 present invention are moved to by external atmospheric pressure The usage state diagram of pushrod chamber；

The decomposition diagram of the second preferred embodiment of Fig. 7 present invention；

The appearance diagram of the third preferred embodiment of Fig. 8 present invention；

The appearance diagram of the 4th preferred embodiment of Fig. 9 present invention；

The appearance diagram of the 5th preferred embodiment of Figure 10 present invention；

The appearance diagram of the 6th preferred embodiment of Figure 11 present invention；

Appearance diagram after the 6th preferred embodiment use of Figure 12 present invention.

Wherein, reference numeral

10 cylinder, 101 Large Diameter Pipeline section

102 pipe with small pipe diameter section, 11 syringe needle group installation end

110 needle bodies stretch out 111 drag reduction spacing of hole

112 against 113 rib of terrace edge

114 needle stands shield and sustain hole

12 operation 120 hand grip portions of holding end

1201 label hole, 121 upstream end

122 bulge loop, 13 barrel chamber

130 blocking bulge loop, 131 needle stand positioning section

132 active segments

20th, 21 movable push bar of 20A pushing pieces

210 pushrod chamber, 211 first snap ring

212 outer ring edge, 213 ring sleeve portion

214 engaging 215 inner ring of edge

216 medicaments push 217 operating side of end

218 second snap rings

22nd, 22E outer gas crammed plug 221 plugs together hole

Airtight stopper in 222 circular grooves 23,23A, 23D, 23E

231 protrusion, 2311 concave ring groove

232 plug together 2321 annular groove of portion

233rd, 234 plug slot of 233A needle stands connecting portion

235 gas-tight ring 231E convex sections

2311E screw parts 232E plugs together section

2321E spiro union portion 2322E annular grooves

24 end cap, 241 lid body

242 lids close 243 base of slot

244, which shield and sustain pipe 2440, engages edge

30 pumpback part, 31 pull rod

311 block ends 3110 fix bulge loop

3111 blocking ring edge, 312 holding end

3120 grooves 313 recess notch

32 airtight 321 holding sections of plug sleeve

322 engaging slots 3220 fix ring edge

323 ring card slots

40th, 41 needle body of 40A syringe needles group

42nd, 421 needle body mounting hole of 42A needle stands

422nd, 4220 profile groove of 422A fitting portions

423 relief edge, 43 needle stand retainer ring

431 abutment face, 432 blocking annular groove

Airtight 50 needle cover of mounting hole of 433 needle stands

60 medicaments

A, B, C, D, E safety injector

Specific embodiment

In order to understand the technical characteristic and practical effect of the present invention in detail, and can come according to the content of specification real It applies, further with preferred embodiment as shown in drawings, is described in detail as after：

A kind of safety injector of the present invention, it is about 3CC that the first preferred embodiment please referred to Fig.1 to Fig.4, which is injection volume, Safety injector A, and include a cylinder 10, a pushing piece 20, a pumpback part 30, a syringe needle group 40 and a needle cover 50.

As shown in Figures 1 and 2, and the left and right direction of predefined Fig. 1, Fig. 2 are hereinafter described front and rear direction.The cylinder Body 10 is the hollow cylindrical body extended along front and rear direction, and is located at the Large Diameter Pipeline section 101 with a Large Diameter Pipeline section 101 and one Front end and the pipe with small pipe diameter section 102 for forming gradually-reducing shape, the one of the pipe with small pipe diameter section 102 is connected in the Large Diameter Pipeline section 101 of the cylinder 10 End is defined as a syringe needle group installation end 11 and reversely one end far from the syringe needle group installation end 11 is defined as an operation holding end 12, a barrel chamber 13 is then formed in the inside of the Large Diameter Pipeline section 101, for the storage of suction medicament and injection.

Wherein, a needle body for being through to the barrel chamber 13 is formed in the pipe with small pipe diameter section 102 to stretch out hole 110 and stretch in the needle body The 110 rear ring wall of portalling forms and the needle stand in hole 110 is stretched out greater diameter than the needle body shields and sustain hole 114, and shield and sustain in the needle stand The adjacent ring wall that hole 110 is stretched out in hole 114 with the needle body forms one against terrace edge 112, and the rear end ring in hole 114 is shielded and sustain in the needle stand Wall is then equipped with multiple ribs 113, which shields and sustain the structure of the syringe needle group 40 for assistance, which shields and sustain hole 114 Front end is neighbouring should to be formed with a drag reduction spacing 111 for 40 displacement of syringe needle group against terrace edge 112, the needle stand shield and sustain hole 114 with This respectively helps item 113 that the syringe needle group installation end 11 collaboration is coordinated to shield and sustain, position the syringe needle group 40.

The hand grip portion 120 for being formed and radially outward being protruded is surround in the periphery wall of the operation holding end 12 of the cylinder 10, in this Hand grip portion 120 offers multiple label holes 1201 installed for label or famous brand, and in the rear end shape of the operation holding end 12 Into a upstream end 121 open backwards, one around protrusion is formed adjacent to the internal ring wall of the operation holding end 12 in the cylinder 10 Bulge loop 122；It sets to form a blocking bulge loop 130, the blocking in the ring wall ring for being adjacent to the syringe needle group installation end 11 in the barrel chamber 13 Internal diameter reduces at bulge loop 130, and the barrel chamber 13 separated to be formed one adjacent to the syringe needle group installation end 11 needle stand positioning section 131 and One is located at the active segment 132 of negative direction.

The barrel chamber 13 that the pushing piece 20 airtight can slippingly be set to the cylinder 10, and include a movable push bar 21, one Airtight 23 and one end cap 24 of stopper in outer gas crammed plug 22, one；Wherein, the movable push bar 21 is roughly the same and forward and backward for caliber The hollow straight pipe of perforation, and include medicament push end 216 that adjacent front end edge and internal diameter slightly reduce and reversely stretch out should An operating side 217 except barrel chamber 13, the movable push bar 21 close are set to the barrel chamber with displacement with medicament push end 216 is annoying 13 active segment 132 forms a pushrod chamber 210, and respectively in the inner wall of the pushrod chamber 210 neighbour in the inside of the movable push bar 21 Nearly medicament push end 216 around be convexly equipped with one first snap ring 211 and one close to the operating side the second snap ring 218, and in this Movable push bar 21 is adjacent to 217 periphery wall of operating side around an outer ring edge 212 is formed, and the movable push bar 21 is with the outer ring edge 212 The corresponding bulge loop 122 for being equipped in the cylinder 10 makes the movable push bar 21 after the completion of medicament injection, can inlay card in the barrel chamber 13 It is interior and be not easily disconnected from, formed at medicament push 216 end of end of the movable push bar 21 one be in step shape ring sleeve portion 213, in the work It then surround and is convexly equipped in the internal perisporium of the ring sleeve portion 213 around an engaging edge 214 is convexly equipped on the outside of the rear end peripheral wall of dynamic push rod 21 One inner ring 215.

The outer gas crammed plug 22 corresponds to the ring sleeve portion 213 for being sleeved on the movable push bar 21, in the outer gas crammed plug 22 What centre formed forward and backward perforation plugs together hole 221, and formed in the inner wall for plugging together hole 221 for be fastened on the ring sleeve portion 213 one Circular groove 222.

The interior airtight stopper 23 airtight can be equipped in the internal perisporium at the medicament push end 216 of the movable push bar 21, and airtight The outer gas crammed plug 22 is sleeved on, which is in the column block of step shape and plugs together portion with a protrusion 231, one 232nd, a needle stand connecting portion 233 and a plug slot 234, the protrusion 231 and this plug together portion 232 respectively be located at the interior airtight stopper 23 front and rear sections, the diameter of the protrusion 231 are less than the diameter for plugging together portion 232, wherein, the periphery wall ring of the protrusion 231 Be arranged with a concave ring groove 2311, the protrusion 231 correspond to airtightly penetrate the outer gas crammed plug 22 plug together hole 221, and with this Concave ring groove 2311 corresponds to and the airtight inner ring 215 for being sticked in the ring sleeve portion 213, which, which surround, is recessed with One annular groove 2321, this plugs together the first snap ring 211 that portion 232 is corresponded to the annular groove 2321 and is airtightly equipped in the movable push bar 21 Place enables the interior airtight stopper 23 to be fixed on the movable push bar 21 and seal sleeve together in the outer gas crammed plug 22；The needle stand connects Socket part 233 is the pattern of groove and is hollowly formed in the front end face centre of the protrusion 231, which is then recessed It is formed in the rear end face centre for plugging together portion 232.

The end cap 24 corresponds to the operating side 217 for being sticked in the movable push bar 21, which has a cylindrical lid The lid that body 241, one is formed in 241 internal ring wall of lid body closes the formation of base 243, one that slot 242, one closes 241 Single port of lid body Pipe 244 is shielded and sustain into concentric column and front and rear perforation in 243 center of the base and with the lid body 241, this shields and sustain pipe 244 towards the lid The equidirectional Single port inner edge in 241 openend of body is convexly equipped with a locking edge 2440.

The pushrod chamber 210 that the pumpback part 30 airtight can slippingly be set to the movable push bar 21, the pumpback part 30 include One pull rod 31 and an airtight plug sleeve 32, the pull rod 31 are formed with the long rod of multiple ribs, and be respectively provided with a fixing for periphery 311 and one holding end 312 of end, the pull rod 31 are pierced by the pushrod chamber with 312 end of holding end by the pipe 244 of shielding and sustain of the end cap 24 Outside 210, and the airtight plug sleeve 32 is engaged with the reversed block end 311 and is stretched into the pushrod chamber 210, make the airtight plug sleeve 32 The interior airtight stopper 23 is bonded, which is located at the front end of the pull rod 31 and is equipped with multiple interval settings and is surrounded on this The fixing bulge loop 3110 of pull rod 31, the pull rod 31 are convexly equipped with a blocking ring edge in overhead kick shape in each rear side for fixing bulge loop 3110 3111, which forms an annular recess notch 313, and the recess notch in the rear side of the neighbouring blocking ring edge 3111 313 become the point of application that the pull rod 31 fractures, and the pull rod 31 are enable to be broken off by being equipped with the recess notch 313, the gripping End 312 is located at the rear end of the pull rod 31 and is pierced by the end cap 24, and forms multiple interval settings and be surrounded on the pull rod 31 Groove 3120 enables the pull rod 31 to increase frictional force when pulling by the setting of each groove 3120.

The airtight plug sleeve 32 is incorporated into the block end 311 of the pull rod 31, and forms correspondence in the front end of the airtight plug sleeve 32 An engaging slot 322 is equipped in the holding section 321 of 234 shape of plug slot, and in the rear end central fovea of the airtight plug sleeve 32, in this The internal face of engaging slot 322 is then around the fixing ring edge 3220 for the internal diameter for being more than the engaging slot 322 equipped with an internal diameter, the airtight stopper Set 32 is fastened on the fixing bulge loop 3110 of the block end 311 with the fixings ring edge 3220 of the engaging slot 322 correspondence, so reach compared with Good fixed effect surround the ring card slot 323 for forming a recess, the ring card slot 323 in the circumferential lateral surface of the airtight plug sleeve 32 Shape correspond to the shape of second snap ring 218, the airtight plug sleeve 32 is enable to be fastened in using the ring card slot 323 correspondence At second snap ring 218.

The syringe needle group 40 corresponds to the syringe needle group installation end 11 for being installed on the cylinder 10, and includes a needle body 41, one and be arranged Needle stand 42 and one in 41 outside of the needle body is sheathed on the needle stand retainer ring 43 in 42 outside of needle stand, the needle stand 42 it is cylindrical and A needle body mounting hole 421 with the center that is formed in holds the needle body 41 for sticking together, and the needle stand 42 is shielded and sustain with front end in the needle Seat is shielded and sustain between hole 114 and each rib 113, and is spaced the drag reduction spacing 111 against terrace edge 112 with this, in the needle stand 42 Rear end forms a fitting portion 422, which is the circle bolt shape cylinder pattern of protrusion, and shape is interior airtight corresponding to this The needle stand connecting portion 233 of stopper 23, and can correspond to and be fastened in needle stand connecting portion 233, it is equipped in the fitting portion 422 and connects together The profile groove 4220 of the needle body mounting hole 421, the profile groove 4220 can be as the medicaments discharged inside the cylinder 10, in the needle stand 42 Adjacent to the peripheral surface of the fitting portion 422, then ring sets to form a relief edge 423 in outside.

The needle stand retainer ring 43 is in hollow cylindrical elastomer, and the rear end face of the needle stand retainer ring 43 forms an abutment face 431, the outer circumferential surface of the needle stand retainer ring 43 is equipped with a correspondence and the airtight blocking annular groove for being fastened in the blocking bulge loop 130 432, it forms the relief edge 423 corresponding to the needle stand 42 in the inner peripheral of the needle stand retainer ring 43 and the needle stand in penetration state is airtight Mounting hole 433, the needle stand retainer ring 43 are corresponded to the airtight mounting hole 433 of the needle stand and airtight are linked in the relief edge 423, and fixed The needle stand 42.

The needle cover 50 corresponds to the syringe needle group installation end 11 for being linked in the cylinder 10, and is covered on the needle body of the syringe needle group 40 The needle body 41 is accidentally touched in 41 periphery accidentally to avoid medical staff.

The occupation mode of present pre-ferred embodiments as shown in Figures 3 to 6, first, illustrate by the action for please referring to Fig. 3, and one User can pull back the pull rod 31 of the pumpback part 30, make the pull rod 31 and the airtight plug sleeve 32 by external force and in the work 210 intrinsic displacement of pushrod chamber of push rod 21 is moved, and the air in the pushrod chamber 210 is removed by the airtight plug sleeve 32, until this is airtight Plug sleeve 32 moves the rear end of the movable push bar 21 to, and the card for being sticked in the end cap 24 is corresponded to the blocking ring edge 3111 of the pull rod 31 Only edge 2440 make the pull rod 31 be fixed on the end cap 24, and the recess notch 313 of the pull rod 31 just can be close to this at this time The rear of end cap 24, user is again firmly by the pull rod 31 towards lateral switch out, it will makes the block end 311 and the gas of the pull rod 31 Close plug sleeve 32 is fixed on the rear end of the pushrod chamber 210, and the inside of the movable push bar 21 is made to form an extremely low air pressure space.

As shown in figure 4, the user can unload needle cover 50 (not shown), and with the needle body 41 according to known syringe phase The same medicament 60 extracted using technology in solution medicinal cupping, and by the way that the pushing piece 20 is pushed to be injected to the medicament 60 forward In human body, and it is mutual by the needle stand retainer ring 43 and the outer gas crammed plug 22 and the needle stand 42 and the interior airtight stopper 23 Corresponding airtight fitting, can completely inject the medicament 60 and rarely medicament is remained in syringe.

As shown in figure 5, after the medicament 60 is injected completely, the front end face of the pushing piece 20, which will be pushed to, urgently to be pasted The rear end face in the needle stand retainer ring 43 of the syringe needle group 40 is closed, and also correspondence is closely embedded in this to the fitting portion 422 of the needle stand 42 The needle stand linking part 233 of interior airtight stopper 23, at this time the user further push the pushing piece 20, make 42 front-end edge of needle stand The drag reduction spacing 111 is pushed into, and is locked to this against terrace edge 112, while and drives the needle stand retainer ring 43 and the card Bulge loop 130 processed forms dissociation fixing state, and when the pushing piece 20 is persistently pushed ahead, which will be pushed into In the needle stand positioning section 131 of the barrel chamber 13, and seal sleeve conjunction state is dissociated with the needle stand 42, meanwhile, the interior gas of the pushing piece 20 Crammed plug 23 is also synchronous with the airtight blocking state at medicament push end 216 to be dissociated, until the pushing piece 20 is by the end cap 24 Until the limitation of upstream end 121 against each other, which is fitting to connection partly has been pushed into the interior airtight stopper 23 In in the pushrod chamber 210 of extremely low atmospheric pressure state, at this time as shown in fig. 6, because the extremely low air pressure to prestore inside the pushrod chamber 210 is empty Between state will cause extraneous larger atmospheric pressure by the interior airtight stopper and the needle stand of the fitting connection 42 and the needle body 41 It is synchronous to be pushed into the pushrod chamber 210, and generate the effect of the needle body 41 and the 42 automatic pumpback of needle stand.

Thus, the extremely low air pressure for making to be formed immediately inside the pushing piece 20 by the operation of the pumpback part 30 of the present invention The design in space, after medicament injecting program is completed, it is only necessary to by the pushing piece 20 persistently promote, it will be able to allow the needle body 41 and The needle stand 42 is recycled to pushrod chamber 210 due to the transmission effect of pressure, using upper very intuition, and effectively simplifies production The process of making can reach the demand for reducing cost, and user, which does not need to risk again, has the risk for touching the needle body 41 It is recycled or is destroyed, quite with practical value.

The present invention the second preferred embodiment as shown in fig. 7, its with the present invention first preferred embodiment it is roughly the same, it is poor The needle stand 42A of the different interior airtight stopper 23A and syringe needle group 40A for being pushing piece 20A；Wherein, the interior airtight stopper 23A Needle stand linking part 233A protrudes out the pattern to form cylinder bolt shape forward, and the fitting portion 422A of needle stand 42A then corresponds to the needle Seat linking part 233A forms the circle bolt shape groove body in recess, and needle stand linking part 233A can correspond to fitting portion 422A, other Structure and use state it is identical with the first preferred embodiment, do not described herein.

The third preferred embodiment of the present invention is as shown in figure 8, its first and second preferred embodiment substantially phase with the present invention Together, Fig. 8 discloses the safety injector B that injection capacity is about 5CC, other structures and occupation mode, preferably real with first It is roughly the same to apply example.

The present invention the 4th preferred embodiment as shown in figure 9, its with the present invention first preferred embodiment it is roughly the same, figure 9 disclose the safety injector C that injection capacity is about 1CC, the outer gas crammed plug 22 air-tight connection medicament push end 216 and gas The protrusion 231 of the interior airtight stopper 23, other structures and occupation mode are thickly sleeved on, it is big with the first preferred embodiment It causes identical.

The 5th preferred embodiment of the present invention is as shown in Figure 10, roughly the same with the first preferred embodiment of the present invention, Figure 10 discloses the safety injector D that injection capacity is about 0.5CC, wherein, because the cylinder caliber of 0.5CC is smaller, in the interior gas Plugging together for crammed plug 23D is arranged with the inner wall airtight joint of multiple gas-tight rings 235 and movable push bar 21D outside portion 232, and makes this Interior airtight stopper 23D achieve the effect that can airtight movement, the airtight plug sleeve 32D also kenels annular in shape positioned at pull rod 31D front ends With the inner wall airtight joint of movable push bar 21D, other structures and occupation mode, with the first preferred embodiment substantially phase Together.

The 6th preferred embodiment of the present invention is as shown in Figure 11, Figure 12, and the first preferred embodiment with the present invention is substantially Identical, the component that only the interior airtight stopper 23E of the safety injector E disclosed by Figure 11 can be decomposed by two is respectively a convex section 231E plugs together section 232E with one and is assembled in a screw connection manner, and outer gas crammed plug 22E and the medicament of the pushing piece 20 push end 216 it is airtight screw togather and correspond to the convex section 231E for being sticked in the interior airtight stopper 23E, and can airtightly slide in the barrel chamber 13 It is interior, the periphery wall of convex section 231E with outer gas crammed plug 22E is airtight engages, and its front end face forms the needle stand linking part 233, one screw part 2311E of end face formation thereafter；This plugs together the screw part 2311E that section 232E front end faces correspond to convex section 231E And a spiro union portion 2321E is formed, and can closely screw togather and be integrated with screw part 2311E, periphery wall surround and is recessed with a ring Slot 2322E, this plugs together section 232E and corresponds to airtight the first snap ring 211 being equipped in the movable push bar 21 with annular groove 2322E, His structure and occupation mode, it is roughly the same with the first preferred embodiment.

The present invention is internally provided with pumpback part in pushing piece, by way of manual pull pumpback part, makes the interior of pushing piece Portion instantaneity landform poling low pressure space, and the pull of vacuum that prestores, then by pushing to pushing piece in injection process Appropriate location makes needle body and needle stand be linked to interior airtight stopper and synchronize and enter to pushrod chamber by extraneous atmospheric pressure push It is interior, to achieve the effect that the automatic and needle body that safely bounces back, also, it is the simple knot by concave-convex opposite blocking between each component Structure closes to achieve the effect that chimeric and detach, the construction inside substantial simplifications syringe, and also simplify production and technique Flow, and then generate reduce manufacture cost effect, quite with practical value.

Certainly, the present invention can also have other various embodiments, without deviating from the spirit and substance of the present invention, ripe It knows those skilled in the art and makes various corresponding changes and deformation, but these corresponding changes and change in accordance with the present invention Shape should all belong to the protection domain of appended claims of the invention.

Claims (30)

1. a kind of safety injector, which is characterized in that including：

One cylinder is a hollow cylindrical body, and is located at the Large Diameter Pipeline section front end with a Large Diameter Pipeline section and one and is formed tapered The pipe with small pipe diameter section of shape, one end that the pipe with small pipe diameter section is connected in the Large Diameter Pipeline section of the cylinder are defined as a syringe needle group installation end and anti- An operation holding end is defined as to one end far from the syringe needle group installation end, a barrel chamber is then formed in the inside of the Large Diameter Pipeline section, A blocking bulge loop is formed in the ring wall projection that the syringe needle group installation end is adjacent in the barrel chamber；

One pushing piece airtight can slippingly be set to the barrel chamber of the cylinder, and include：

There is one movable push bar a hollow pushrod chamber, one can slide in the barrel chamber and interior caliber is in slightly reducing shape Medicament pushes end and one extends to the operating side outside the barrel chamber；

Airtight stopper in one is airtightly equipped in the pushrod chamber at medicament push end；

One outer gas crammed plug, with the medicament of the movable push bar push end and this interior airtight stopper is mutually airtight engages, and can It airtightly slides in the barrel chamber；

One end cap is fastened in the operating side of the movable push bar, and shields and sustain pipe by end cap central is perforative with one；

One pumpback part, can the airtight pushrod chamber for being slippingly set to the movable push bar, the pumpback part include a pull rod and One airtight plug sleeve, the pull rod are pierced by outside the pushrod chamber with a holding end by the pipe of shielding and sustain of the end cap, and with a reversed block end Engage the airtight plug sleeve and stretch into the pushrod chamber, the airtight plug sleeve is made to be bonded the interior airtight stopper；

One syringe needle group corresponds to and is installed on the syringe needle group installation end of the cylinder, and includes a needle body, one is sheathed on outside the needle body The needle stand of side and one needle stand retainer ring on the outside of the needle stand is sheathed on, which is set in the barrel chamber of the syringe needle group installation end, And shielded and sustain in the pipe with small pipe diameter section with front end, which is sticked in the blocking bulge loop in the Large Diameter Pipeline section, the needle stand Rear end form a fitting portion, which is incorporated into airtight gear in the pushing piece with the corresponding and concave-convex blocking of the fitting portion Plug；

The pumpback part, in airtightly pulling back displacement in the movable push bar, the pushrod chamber is removed by the airtight plug sleeve by the pull rod Interior air, and the rear end of the movable push bar is equipped in, make to form an extremely low air pressure space inside the movable push bar, and in medicament After the completion of injection, push the needle stand retainer ring of the syringe needle group forward by the pushing piece, make the needle stand retainer ring be detached from the needle stand and The blocking bulge loop of the cylinder enables the needle stand link interior airtight stopper synchronization and moves into the movable push bar, and by the big of the external world The interior airtight stopper is combined atmospheric pressure the needle stand and the needle body is pushed into the movable push bar, uses generation safety, automatic pumpback The effect of needle body.

2. safety injector according to claim 1, which is characterized in that the front end face canyon topography of the interior airtight stopper into There is the needle stand connecting portion that one is in groove body pattern, and the fitting portion of the needle stand is in step shape and is formed in the rear end of the needle stand, And the fitting portion corresponds to the needle stand connecting portion and is in the hitching post build formula protruded.

3. safety injector according to claim 1, which is characterized in that the front end of the interior airtight stopper forward-facing protrudes out shape Cheng Youyi is in the needle stand connecting portion of circle hitching post build formula, and the fitting portion of the needle stand is corresponding to the needle stand connecting portion and in rear end It is formed in groove body.

4. safety injector according to claim 1, which is characterized in that one is formed in the pipe with small pipe diameter section of the cylinder and is through to The needle body of the barrel chamber of the Large Diameter Pipeline section stretches out hole and the rear ring wall in needle body stretching hole is formed and stretched greater diameter than the needle body The needle stand to portal shields and sustain hole, and in the needle body stretch out hole and the needle stand shield and sustain the adjacent ring wall in hole be formed with one can be for the needle stand Front-end edge against against terrace edge.

5. safety injector according to claim 4, which is characterized in that the needle stand shields and sustain that hole front end is neighbouring should be against terrace edge It is formed with a drag reduction spacing for the needle stand displacement.

6. safety injector according to any one of claim 1 to 5, which is characterized in that be somebody's turn to do in the pushrod chamber in neighbouring One first snap ring is formed on the ring wall at medicament push end.

7. the safety injector according to claim 6, which is characterized in that in the ring of the neighbouring operating side in the pushrod chamber One second snap ring is formed on wall.

8. the safety injector according to claim 6, which is characterized in that the interior airtight stopper is in the column block of step shape And plug together portion and a plug slot with a protrusion, one, the protrusion and the portion of plugging together be located at the interior airtight stopper respectively before, Back segment, the diameter of the protrusion are less than the diameter for plugging together portion, which is formed in the front end face center of the protrusion Place, which, which falls into, is formed in the rear end face centre for plugging together portion, which, which surround, is recessed with an annular groove, This plugs together the first snap ring that portion is equipped in the movable push bar with annular groove correspondence, and the protrusion is airtight to be sticked in medicament push end Internal perisporium.

9. safety injector according to claim 8, which is characterized in that the medicament push end of the movable push bar forms a ring Set portion, the outer gas crammed plug correspond to seal sleeve together in the ring sleeve portion and the protrusion of the interior airtight stopper and can airtight sliding in In the barrel chamber of the cylinder, and can be against the rear end face for the needle stand retainer ring for fitting in the syringe needle group.

10. the safety injector according to claim 8, which is characterized in that the outer gas crammed plug of the pushing piece and the medicine Agent pushes end airtight joint and corresponds to protrusion of the seal sleeve together in the interior airtight stopper, and can airtightly slide in the cylinder Barrel chamber in.

11. the safety injector according to claim 8, which is characterized in that the medicament push end of the movable push bar is formed One screw part, and the outer gas crammed plug and the screw part are airtight screws togather and the corresponding airtight protrusion for being sticked in the interior airtight stopper Portion, and can airtightly slide in the barrel chamber of the cylinder.

12. safety injector according to claim 8, which is characterized in that the internal perisporium in medicament push end surround convex Equipped with an inner ring, the periphery wall of the protrusion of the interior airtight stopper is around a concave ring groove is equipped with, and the protrusion is with the concave ring groove pair Should and it is airtight be sticked in the movable push bar the medicament push end inner ring.

13. the safety injector according to claim 12, which is characterized in that the protrusion of the interior airtight stopper and the plug Conjunction portion can be decomposed into a convex section and one plugs together section, and can mutually screw togather and be integrated and form the interior airtight stopper, this is convex Going out the periphery wall of section, outer gas crammed plug is airtight engages, and its front end face forms the needle stand connecting portion with this, and end face forms one thereafter Screw part；This plugs together section front end face and corresponds to the screw part of the convex section and form a spiro union portion, and can be close with the screw part Spiral shell is integrated, and for periphery wall around being recessed with an annular groove, this, which is plugged together section and is corresponded to the annular groove, airtight is equipped in the of the pushrod chamber One snap ring.

14. safety injector according to claim 6, which is characterized in that the pull rod of the pumpback part is formed with more for periphery The long rod of a rib, both ends are respectively the block end and the holding end, which is located at the front end of the pull rod and is equipped with Multiple fixing bulge loops being arranged at intervals and be surrounded on the pull rod, the holding end are located at the rear end of the pull rod and are pierced by the end cap, The pull rod is equipped with a recess notch at the neighbouring fixing bulge loop rear, which forms the point of application that the pull rod fractures.

15. safety injector according to claim 14, which is characterized in that the fixing bulge loop of the pull rod and the recess notch Between be equipped with one be in overhead kick shape blocking ring edge, and form a locking edge, the pull rod in the port ring wall for shielding and sustain pipe of the end cap Blocking ring edge can correspond to and be snapped in the locking edge.

16. safety injector according to claim 15, which is characterized in that the pumpback part should by pull rod block end engaging Airtight plug sleeve, and pulled back by the holding end and move the pumpback part, the blocking ring edge of the pull rod is made to be locked to the locking edge of the end cap, And in the vacuum attraction energy that an extremely low air pressure space is generated in the pushrod chamber.

17. safety injector according to claim 14, which is characterized in that the pumpback part should by pull rod block end engaging Airtight plug sleeve, and pulled back by the holding end and move the pumpback part, the airtight plug sleeve is made to be equipped in the second card of the push rod cavity rear end Ring, and in the vacuum attraction energy that an extremely low air pressure space is generated in the pushrod chamber.

18. a kind of needle body needle stand pumpback device of safety injector, which is characterized in that including：

One pushing piece in the barrel chamber of a cylinder that airtight can be slippingly set to a syringe, and includes an activity Push rod, airtight stopper, an outer gas crammed plug and an end cap in one；Wherein, which has a hollow pushrod chamber, an energy In in the barrel chamber and interior caliber extends to the operating side outside the barrel chamber in the medicament push end and one for slightly reducing shape, this is pushed away for enough slidings In being formed with one first snap ring on the ring wall at neighbouring medicament push end in rod cavity, the pushrod chamber is interior in the ring adjacent to the operating side One second snap ring is formed on wall, which is airtightly equipped in the pushrod chamber at medicament push end, this is outer airtight The medicament of stopper and the movable push bar push end and this interior airtight stopper is mutually airtight engages, and can airtightly slide in the cylinder Intracavitary, which is fastened in the operating side of the movable push bar, and shields and sustain pipe by end cap central is perforative with one；

One pumpback part, can the airtight pushrod chamber for being slippingly set to the movable push bar, the pumpback part include a pull rod and One airtight plug sleeve, the pull rod are pierced by outside the pushrod chamber with a holding end by the pipe of shielding and sustain of the end cap, and with a reversed block end Engage the airtight plug sleeve and stretch into the pushrod chamber, the airtight plug sleeve is made to fit in the interior airtight stopper.

19. the needle body needle stand pumpback device of safety injector according to claim 18, which is characterized in that the interior airtight gear The front end face of plug is hollowly formed with a needle stand connecting portion in groove body pattern, and the fitting portion of the needle stand is in step shape and shape Into in the rear end of the needle stand, and the fitting portion correspond to the needle stand connecting portion and in the hitching post build formula of protrusion.

20. the needle body needle stand pumpback device of safety injector according to claim 18, which is characterized in that the interior airtight gear The front end of plug, which forward-facing protrudes out, is formed with one in the needle stand connecting portion for justifying hitching post build formula, and the fitting portion of the needle stand corresponds to this Needle stand connecting portion and formed in rear end in groove body.

21. the needle body needle stand pumpback device of the safety injector according to claim 18 to 20 any one, feature exist Portion and a plug slot are plugged together in the column block of step shape and with a protrusion, one in, the interior airtight stopper, the protrusion and should The front and rear sections that portion is located at the interior airtight stopper respectively are plugged together, the diameter of the protrusion is less than the diameter for plugging together portion, which connects Socket part is formed in the front end face centre of the protrusion, which, which falls into, is formed in the rear end face centre for plugging together portion, should The periphery wall in portion is plugged together around an annular groove is recessed with, this plugs together the first card that portion is equipped in the movable push bar with annular groove correspondence Ring, the airtight internal perisporium for being sticked in medicament push end of the protrusion.

22. the needle body needle stand pumpback device of safety injector according to claim 21, which is characterized in that the movable push bar Medicament push end form a ring sleeve portion, which corresponds to seal sleeve together in the convex of the ring sleeve portion and the interior airtight stopper Go out portion and airtight can slide in the barrel chamber of the cylinder.

23. the needle body needle stand pumpback device of the safety injector according to claim 21, which is characterized in that the pushing piece Outer gas crammed plug and the medicament push end airtight joint and corresponding protrusion for being sleeved on the interior airtight stopper, and can be airtight Ground is slid in the barrel chamber of the cylinder.

24. the needle body needle stand pumpback device of safety injector according to claim 21, which is characterized in that pushed away in the activity The internal perisporium at the medicament push end of bar is around an inner ring is convexly equipped with, and the periphery wall of the protrusion of the interior airtight stopper is around equipped with one Concave ring groove, the protrusion is with concave ring groove correspondence and the airtight inner ring at medicament push end for being sticked in the movable push bar.

25. the needle body needle stand pumpback device of the safety injector according to claim 21, which is characterized in that the activity pushes away The medicament push end of bar forms a screw part, and the outer gas crammed plug and the medicament push that end is airtight to be screwed togather and corresponding be sticked in this The protrusion of interior airtight stopper, and can airtightly slide in the barrel chamber of the cylinder.

26. the needle body needle stand pumpback device of the safety injector according to claim 25, which is characterized in that this is interior airtight The protrusion of stopper, which with this plugs together portion and can be decomposed into a convex section and one, plugs together section, and can mutually screw togather and be integrated and formed The interior airtight stopper, outer gas crammed plug is airtight engages with this for the periphery wall of the convex section, and its front end face forms needle stand connection Portion, one screw part of end face formation thereafter；This plugs together section front end and corresponds to the screw part of the convex section and form a spiro union portion, and can It closely screws togather and is integrated with the screw part, around an annular groove is recessed with, this plugs together section and corresponds to airtight card with the annular groove periphery wall It is formed on the first snap ring of the pushrod chamber.

27. the needle body needle stand pumpback device of the safety injector according to claim 18 to 20 any one, feature exist The long rod of multiple ribs is formed with for periphery in the pull rod of, the pumpback part, both ends are respectively the block end and the holding end, The block end is located at the front end of the pull rod and equipped with multiple fixing bulge loops being arranged at intervals and be surrounded on the pull rod, the holding end position In the rear end of the pull rod and the end cap is pierced by, which is equipped with a recess notch, the recess at the neighbouring fixing bulge loop rear Notch forms the point of application that the pull rod fractures.

28. the needle body needle stand pumpback device of safety injector according to claim 27, which is characterized in that the card of the pull rod Gu a blocking ring edge in overhead kick shape is equipped between bulge loop and the recess notch, and in the Single port ring wall for shielding and sustain pipe of the end cap A locking edge is formed, the blocking ring edge of the pull rod, which can correspond to, is snapped in the locking edge.

29. the needle body needle stand pumpback device of safety injector according to claim 28, which is characterized in that the pumpback part by The pull rod block end engages the airtight plug sleeve, and is pulled back by the holding end and move the pumpback part, makes the blocking ring edge card of the pull rod The locking edge of the end cap is terminated in, and in the vacuum attraction energy that an extremely low air pressure space is generated in the pushrod chamber.

30. the needle body needle stand pumpback device of safety injector according to claim 27, which is characterized in that the pumpback part by The pull rod block end engages the airtight plug sleeve, and is pulled back by the holding end and move the pumpback part, and the airtight plug sleeve is made to be equipped in this Second snap ring of push rod cavity rear end, and in the vacuum attraction energy that an extremely low air pressure space is generated in the pushrod chamber.