CN102872506A - Medical safety injector - Google Patents

Abstract

A medical safety injector comprises an injection needle assembly, an automatic needle tip recycling device and an injector. The medical safety injector is characterized in that a draw bar, a spring and a front plug are serially connected rotationally and are mounted in an inner cavity of a push rod, the front plug is fastened in an inner hole at the front end of the push rod, and the draw bar penetrates through a side seam of the push rod and is suspended in a slit of a side wall of a handle of an outer barrel. During injection, the push rod is pressed to drive the front plug to move, so that the spring can be lengthened; after the injection is completed, the push rod is pressed again, the annular wall of the front end of the push rod drives a damping ring to move forwards, an embedded needle base is released, an expansion portion of the front plug is simultaneously embedded with an annular bump of an inner hole of the needle base, the front plug under pressure is released from a limitation effect of the inner hole at the front end of the push rod, the spring retracts to drive the front plug, the needle base and the needle tip to return the inner cavity of the push rod, and an injection needle is completely shielded and cannot be released or exposed due to the fact that the total length of the draw bar, the spring, the front plug, the needle base and a needle tube is smaller than the length of the inner cavity of the push rod; as a dovetail narrow portion of a slit at the rear end of the push rod penetrates through a transverse bump of the draw bar, the push rod is limited at the corresponding position and cannot be pulled out again; and the needle base is destroyed, so that the injector is prevented from being reused. Owing to the fact that the needle base is structurally separated from the automatic needle tip recycling device, the injection needle of the medical safety injector can be replaced as needed before the medical safety injector is used, so that the medical safety injector brings convenience for clinical use.

Description

Medical safety syringe

(1), technical field

The present invention relates to a kind of medical apparatus and instruments, specifically a kind of for to the piercing process of tissue and after puncture to organizing administration or extracting the Medical safety syringe of tissue specimen.

(2), background technology

Since the plastics disposable sterilized syringe has appearred in nineteen forties, be reused owing to can not limit it, caused thus a large amount of propagation of blood borne disease, especially take acquired immune deficiency syndrome (AIDS), hepatitis C, hepatitis B as serious; World Health Organization (WHO) (WHO) in 1994 promotion is used: " disposable use self-destroyed syringe ", and how technical staff and enterprise just prevent from, forbid having done a large amount of explorations aspect the reusing of syringe; But, medical personnel and patient's (cross-reference entry needle) are again punctured or stab cause because the basic reason that causes blood borne disease to propagate is injection needle at medical procedure, but not syringe itself; So WHO just proposed again in 1998: the requirement of " disposable use safety needle " requires technical staff and business research production " safety needle ", the pathophoresis that causes with thorough solution needle stick injury; The aid of syringe but be limited to entry needle, must cooperate with syringe (simultaneously) to use, and because the entry needle structure is too simple, realize that the safety self-destruct technical difficulty is larger, the technical staff is many to combine their (entry needle and syringes), studies, and makes it after common the use, interact, realize the purpose of self-destruction and security protection.

At present, the self-destroyed syringe of common various structures (active self-destruction formula or passive type self-destroyed) can be realized unmaking of syringe on the market, and it can not be reused, and but can not carry out security protection and unmakes entry needle; We know, disposable syringe belongs to respectively two different products with disposable needle, respectively has (world) national standard to come standard; Syringe is a container and metering outfit; Entry needle then needs the professional to use or operates, puncture tissue, by the external passage of setting up an administration in the tissue or extracting specimen, and carry out the conveying of medicinal liquid or the collection of tissue specimen by passage; So.Entry needle is that a lancet device, its degree of risk are very high.

Mostly technical scheme in the world and domestic contrast maturation that entry needle can be shielded fully, present is: by effect artificial or machinery (spring) power, with entry needle income syringe or the push rod inner chamber after using, but all have certain deficiency:

1, the mode manually to draw injection needle to enter urceolus needs both hands to realize, has in operation the risk of self stabbing, and does not meet modern prevention standard and requirement: in realizing the syringe safe protection process, only allow one-handed performance.

2, in the mode of spring the automatic recovery injection needle: spring housing is loaded on the structure of needle stand periphery (the preposition scheme of spring of main flow both at home and abroad), so that retracting device is integral structure with (entry needle) needle stand, in a single day syringe dispatches from the factory, just can not again change syringe needle, also different to the requirement of entry needle simultaneously in clinical environment for use make troubles to user; Entry needle also has: owing to can not be changed, in the state of emergency such as ambulatory environment, just can not use this syringe collecting blood sample, because the existence of blood blood clotting mechanism is easy during blood drawing, but to shift specimen in the test tube time, blood has started clotting mechanism, if at this moment force from entry needle, blood preparation to be migrated out, will cause a large amount of fragmentations of hemocyte, make the testing result deviation distortion.So all there is wretched insufficiency in the automatic or manual safety injector that reclaims of syringe needle in the market, has restricted its propagation and employment in clinical.

Chinese patent: CN92109192.3 has announced " a kind of disposable safety injector ", its technical characterictic is the structure that adopts the recovery syringe needle that Compress Spring separates with needle stand, its deficiency is utilize the different structure of plug and needle stand intermeshing, reach the locking of injector push-rod and the startup of security feature, nowadays, its scheme is also failed fine enforcement, because elastic piston mainly is sealing member, want it to bear chimeric triggering, positioning limiting fixator, be difficult to implement, nowadays the inventor also fails fine realization.

Chinese patent: CN200710031083.0 (and relevant similar technical scheme) discloses a kind of mode of filling in and be set with in its appearance Compress Spring before push rod inner chamber front end arranges, basic technical features and above-mentioned identical, certain improvement is arranged, syringe needle can be changed, but the deficiency that exists is that the needle point cutting edge can not be fixed, and is in free position.Can not finely satisfy clinical user demand, bring hidden danger to the operator.Moreover, rely between its entry needle needle stand and the outer hoop damped ring sealing and with the mutual support of taper hole diameter, the guarantee needle stand has certain non-return power (to keep needle point in piercing process, can freely not return and get loose), international (clinical) designing requirement of this power is greater than more than the 10N, this just so that, spring trigger so that moment resilience force to substantially exceed this non-return power, also just require the locking power (keeping the static timeliness after push rod, Compress Spring are in and wind up will keep more than 2 years) to spring will be much higher than spring force.Above technical parameter all can just can overcome push rod to the locking power of spring force with 1,000 very large triggering power at last, could so that syringe obtains definite triggering, start security feature: the entry needle automatic retracted.This triggering (startup) power very large (being not less than 40N) is so that there is uncomfortable sensation in this syringe.

All there is certain deficiency in the technical scheme of above-described various safety injectors, makes product have limitation in clinical practice, can not be popularized.

At present, also not seeing the technical scheme that can solve the Medical safety syringe of above-mentioned deficiency fully both at home and abroad is disclosed.

Medical safety syringe of the present invention has adopted entry needle the automatic recovery protection, push rod at the rear automatic clamped MULTIPLE COMPOSITE safeguard construction of injection; so that this programme rational in infrastructure, safe and reliable, meet China's clinical treatment working specification and therapeutic process requirement; adapt to clinical various complicated environment for use; do not have limitation, the enforcement of use simple, be beneficial to universal.

(3), summary of the invention

The invention provides a kind of Medical safety syringe that can solve above-mentioned deficiency.Technical scheme of the present invention is such: a kind of Medical safety syringe is made of jointly needle assembly, injector assembly, entry needle the automatic recovery protector; It is characterized in that: entry needle the automatic recovery protector is comprised of front plug, spring and pull bar; Needle assembly is made of jointly outer hoop, needle tubing, needle stand, damped ring; Injector assembly is comprised of urceolus, push rod, piston.

Spring is an extension spring, and the exhibition coiling is dredged in the end, two ends, and the pitch at two ends is identical with the thread pitch of front plug rear end and pull bar front end, and the internal diameter of spring is identical with the tooth root external diameter of front plug rear end and pull bar front end screw thread; The diameter of spring is less than the diameter of push rod inner chamber; The pulling force of extension spring is greater than the quality summation of front plug and needle stand and needle tubing, at 0.1～1.0N; The overall diameter of extension spring is less than the diameter of front plug and pull bar.

The outer cylinder front end endoporus has screw thread, the rear end crimping of urceolus forms handle, and the internal diameter expansion of the urceolus hypomere that joins with handle has one vertically to crack at the outer tube side wall of expansion, this width that cracks is slightly larger than the thickness of the transverse process of pull bar, and this height that cracks is slightly larger than the height of the transverse process of pull bar.

Urceolus hollow, there is the termination of undergauge the end of the front end of urceolus, and the antetheca of termination has perforate, and this aperture is slightly larger than the external diameter of needle stand epimere; The internal diameter of urceolus leading portion is slightly less than the internal diameter of urceolus stage casing and back segment.

The front end of front plug is wedge shape and expands protuberance, and the body of front plug is circular, can be chimeric with the lower end endoporus annular projection of needle stand, there is external screw thread the rear end of front plug, its pitch is identical with the both ends of the spring pitch, can form spin fastening.

Pull bar is the L structure, and its front end has an external screw thread, and its pitch is identical with the both ends of the spring pitch, mutually can spin fastening; The tail end of pull bar is the L shape of inflection, and its end is transverse process, and its thickness is slightly less than the width that the sidewall of push rod cracks, and also is slightly less than the width that the sidewall of urceolus hypomere expansion cracks; The height of transverse process also is slightly less than the height that the sidewall of urceolus hypomere expansion cracks.

Pull bar is connected with spring, front plug and is spun fasteningly, and front plug is installed in the push rod front end endoporus, and fastening by the annular projection in the push rod endoporus, the transverse process of pull bar passes cracking of push rod sidewall, in the sidewall that is inlaid in outer tube rear end expansion cracks.

Damped ring is the ring that an elastomeric material is made, and its internal diameter is slightly less than the external diameter of needle stand hypomere; The external diameter of damped ring is slightly larger than the internal diameter of urceolus leading portion, also is slightly larger than the internal orifice dimension of outer hoop.

The pulling force of spring is greater than the summation of front plug, needle stand, needle tubing quality; Total length after pull bar, spring, front plug, needle stand, the needle tubing serial connection is less than the length of push rod inner chamber; When injection finished, after push rod was finished triggering, the distance that spring is stretched was greater than the length of injection needle.

Push rod is tubular structure, and its front end appearance has a ring-shaped groove, and its front end internal orifice dimension is minimum, and the front aperture inwall has an annular projection, and the putting back-end tube wall is rolled up outward and formed the hands handle; Have symmetrical two vertically to crack at the sidewall of the stage casing of push rod and back segment, crack near the crimping place, be dovetail shaped and change, form position limiting structure with transverse process.

Said Medical safety syringe, the endoporus of urceolus leading portion (wall) diameter is slightly less than the internal diameter of urceolus stage casing and back segment, and the endoporus of outer hoop (wall) diameter also is slightly less than the internal diameter of urceolus; In damped ring setting-in and the urceolus leading portion endoporus (wall) or be inlaid in the endoporus (wall) of outer hoop, the needle stand hypomere is inlaid in the endoporus of damped ring, damped ring outer tube inner wall/or outer hoop endoporus (wall) and injecting needle base appearance between form sealing and build-in, this build-in force (frictional resistance) is greater than 10N, to satisfy the non-return power requirement to entry needle; Said safety injector, when not using, its entry needle structure is not related with the entry needle automatic recycling device, so that the present invention can change entry needle before use with the need, for clinical use brings convenience.

The present invention has following technical characterictic and technological progress:

Because safety injector of the present invention is not when using, entry needle is installed in the spiral interface of syringe front end; According to (injection or diagnosis) treatment routine operation, until puncture injection or after treating successfully, extract entry needle, push rod is pressed again, make front plug and needle stand endoporus chimeric, push rod passes damped ring to the needle stand stage casing, is that needle stand is free; Pushing away before the push rod, is to move behind the pull bar, and spring is stretched; Start safety device behind the build-in of front plug disengaging push rod front end endoporus, the spring of stretching is released, and front plug, needle stand, needle tubing is retracted enter push rod endoporus and maintenance.This programme is easy to manufacture, and is safe and reliable, implement simply, not limited by environment for use, widely applicable, is beneficial to universal.

Crack, be shaped with in the rear end of urceolus expansion and crack, with the transverse process of pull bar is combined to form push rod formed position limiting structure because the present invention has adopted to be shaped with in the push rod posterior segment, after use, can be definitely effectively with the push rod locking outside in the cylinder, can not again be pulled out, and avoid being reused.Simultaneously, also entry needle having been regained the push rod inner chamber, is that needle point shields fully, has eliminated the risk of pricking wound, has avoided medical personnel and other staff to be injected pricking wound and causes and infect and pathophoresis.

Because the structure that the present invention has adopted injecting needle base to separate with the pin automatic recycling device, so that the replaceable entry needle of safety injector that present technique proposes, it no longer is limited making range of application, is convenient to penetration and promotion.

(4), description of drawings

Fig. 1 is that the integral body of Medical safety syringe of the present invention consists of decomposing schematic representation;

Fig. 2 is the urceolus of Medical safety syringe of the present invention and the structural representation behind the entry needle assembling parts;

Fig. 3 is the structural representation of the push rod of Medical safety syringe of the present invention;

Fig. 4 is the structural representation of the entry needle retracting device (or push-rod assembly) of Medical safety syringe of the present invention;

Fig. 5 is the overall structure schematic diagram behind each assembling parts of Medical safety syringe of the present invention, when to be used;

Fig. 6 be Medical safety syringe of the present invention after use, trigger view;

Fig. 7 be Medical safety syringe of the present invention after triggering, entry needle retracted push rod inner chamber, the limited structural representation of push rod automatically;

Fig. 8 is the outer tube structure schematic diagram of Medical safety syringe the second embodiment of the present invention;

Fig. 9 is the structural representation after the urceolus of Medical safety syringe the second embodiment of the present invention and entry needle, the damped ring assembling.

(5), specific embodiment

As shown in Figure 1, Medical safety syringe of the present invention by: outer hoop 10, needle tubing 1, needle stand 2, damped ring 3, urceolus 4, piston 5, push rod 6, front plug 7, spring 8, pull bar 9, jointly form.Outer hoop 10, needle tubing 1, damped ring 3, needle stand 2 common needle assemblies; Outer hoop 10 is medicated cap shape hollow structures, the porose 10A of its leading portion, and this aperture is slightly larger than needle stand epimere 2A external diameter; Outer hoop 10 appearances have screw thread 10B; Outer hoop posterior segment hollow, its stage casing internal orifice dimension are greater than the external diameter of needle stand stage casing 2B, and the internal diameter of the back segment endoporus 10C of outer hoop is slightly less than the external diameter of damped ring 3, and the length of the back segment endoporus 10C of outer hoop 10 is greater than more than 2 times of thickness of damped ring 3; Needle tubing 1 front end has keen edge 1A; Damped ring 3 is made for elastic plastic material, and its diameter of bore is slightly less than the external diameter of needle stand 2 hypomere 2C, the external diameter of damped ring 3 is slightly larger than the diameter of the endoporus 10C of outer hoop 10; Needle stand 2 centers are porose, and the external diameter of needle stand 2 stage casing 2B is greater than the external diameter of needle stand epimere 2A, but less than the external diameter of needle stand hypomere 2C; Needle stand 2 hypomere 2C hollows, the lower end inner edge has annular projection, and needle stand hypomere external diameter is slightly larger than the internal diameter of damped ring 3; The front inner wall of urceolus 4 has spiral interface 4A, rear end at urceolus, the operating grip 4B that has crimping to form, junction at handle and outer tube inner wall, this place's outer tube wall enlarges, and at the outer tube inner wall that enlarges the 4C that vertically cracks is arranged, and the width of the 4C that cracks is slightly larger than the thickness of the transverse process 9B of pull bar, the height of 4C of cracking is slightly larger than the height of the transverse process 9B of pull bar, and this 4C that cracks can be with the transverse process 9B build-in of pull bar.Piston 5 is circuluses of being made by elastomeric material, and its inside and appearance have several circular protrusions or groove; The epimere of push rod 6 has individual ring-shaped groove 6B, can match chimeric with piston 5 endoporus; The epimere front end of push rod 6 is porose, and its hole inwall has an annular projection 6A (referring to Fig. 3), and the push rod afterbody turns up to be expanded into and presses handle 6C, push rod hollow, at the middle hypomere of push rod, with axial symmetry a pair of 6D that cracks that runs through is arranged, be the narrow 6E of dovetail shaped at the 6D that should crack near the handle place and change; Crack the width of 6D greater than the thickness of the transverse process 9B of pull bar; The front end of front plug 7 has the bulb of expanding 7A, the body of front plug be circular, its slightly larger in diameter in the internal diameter of push rod front end endoporus annular projection 6A, the rear end of front plug 7 is column, appearance has screw thread 7B, the internal diameter of its root diameter and spring 8 two ends 8A mates; Spring 8 is normal extension springs, and its two ends 8A unfolds coiling, the pitch of its pitch and internal diameter and pull bar front end screw thread 9A and front plug rear end appearance screw thread 7A and the expansion shape that the tooth root external diameter is complementary; Their series connection that mutually spins.

Fig. 2 is the urceolus of Medical safety syringe of the present invention and the structural representation behind the entry needle assembling parts; Outer hoop 10 screws among the female thread 4A of outer cylinder front end, mutually closely cooperates with its appearance screw thread 10B; The epimere 2A of bonding needle tubing 1, needle stand 2 is installed in the front aperture 10A of outer hoop 10 in needle stand 2 endoporus, in the endoporus of the hypomere 2C appearance suit damped ring 3 of needle stand 2, the length of the inner chamber of outer hoop 10 is greater than more than 2 times of damped ring 3 thickness, damped ring 3 is compressed to be installed among the endoporus 10C of outer hoop 10, closely chimeric with outer hoop 10 formation, consist of needle assembly.

Fig. 3 is the structural representation of the push rod of Medical safety syringe of the present invention; Push rod 6 hollows, epimere appearance have a ring-shaped groove 6B, can match chimeric with piston 5 endoporus; The front end of push rod 6 is porose, and the aperture is less than push rod stage casing and hypomere aperture; The sector hole inwall has an annular projection 6A on the push rod, and the push rod afterbody turns up to be expanded into and presses handle 6C, at the middle hypomere of push rod, with axial symmetry a pair of 6D that vertically cracks that runs through is arranged, near the handle place, this cracks and is the narrow 6E of dovetail shaped and changes, and the width of the 6D that cracks is greater than the thickness of the transverse process 9B of pull bar 9;

Fig. 4 is the structural representation of the entry needle retracting device (or push-rod assembly) of Medical safety syringe of the present invention; As seen from the figure, in an end 8A of the rear end of front plug 7 screw thread 7B appearance rotation set dress extension spring 8, the body of front plug 7 is installed in the endoporus of push rod 6 front ends, and by the annular projection 6A build-in of push rod front end endoporus; The wedge shape of front plug 7 front ends is expanded the 7A of section and is protruded from the front end of push rod 6; Piston 5 is sleeved among the ring-shaped groove 6B of front end appearance of push rod 6; Pull bar 9 is L shape structure, and the threaded rod 9A rotation set of its front end and is installed in the endoporus of push rod 6 in the other end of spring 8, and the sidewall that the transverse process 9B of pull bar 9 passes push rod 6 6D that cracks is suspended from outside the sidewall of push rod, and is positioned at the stage casing of push rod 6 by extension spring 8 tractives; Above composition push-rod assembly also is the overall structure of entry needle retracting device.

Overall structure schematic diagram when Fig. 5 is to be used behind the assembling parts of Medical safety syringe of the present invention; As seen from the figure, needle tubing 1 is bonded in the mesopore of needle stand 2, and the hypomere 2C of needle stand 2 is assembled in the endoporus of outer hoop 10 by damped ring 3; Outer hoop 10 spins fixing by the internal thread interface 4A of external screw thread 10B and urceolus 4 front ends; Piston 5 is nested to be contained among the ring-shaped groove 6B of push rod 6 front ends, and the outer tube inner chamber of then packing into is tight slipper seal; 8 one sections on the threaded rod 7A of front plug 7 rear ends and spring are rotated with; The body of front plug 7 is fastening by the annular projection 6A of push rod 6 front end endoporus; The threaded rod 9A of pull bar 9 front ends and the other end of spring 8 are rotated with, the transverse process 9B of pull bar tail end passes the 6D that cracks of hypomere sidewall in the push rod, be suspended from the lateral wall, stage casing of push rod 6, and the sidewall that penetrates the outer tube inner wall that urceolus 4 back segments enlarge cracks vertically in the 4C, be fixed.

Fig. 6 be Medical safety syringe of the present invention after use, trigger the structural representation of state; As seen from the figure, when injecting liquid drug or treat near when complete, spring 8 and be pulled prolongation by the mutual motion of pull bar 9 and front plug 7; Push rod 6 moves forward with needle stand 2 and interacts, the wedge shape of front plug 7 is expanded the 7A of section and is goed deep in the endoporus of needle stand 2 hypomere 2C, chimeric with endoporus lower edge annular projection, along with the continuation of push rod 6 is goed deep into, the annular ancient piece of jade, round, flat and with a hole in its centre of push rod front end can be with the stage casing 2B of damped ring 3 front passing to needle stand 2, because the diameter of needle stand 2 stage casing 2B is in free state less than the internal diameter of damped ring 3 so that needle stand 2 has broken away from restriction and the build-in of damped ring; Along with to push rod 6 continue press, the continuation of plug 7 deeply before driving, because it is chimeric with needle stand 2 rear end endoporus that front plug 7 front ends expand the 7A of section, and needle stand 2 stage casing 2B external diameters can not move outward greater than the aperture of outer hoop 10 front end perforate 10A, above-mentioned thrust reaction is in front plug 7, move after making front plug 7, relatively move with push rod 6 front end endoporus, moved, broken away from restriction and the build-in of annular projection 6A in the push rod front end endoporus behind the front plug 7; Cause at last between front plug 7 and the push rod 6 slippage with separate.Push rod 6 pushes when making damped ring 3 break away from needle stand hypomere 2C to stage casing 2B fully in the urceolus 4, the crack narrow 6E of cracking of dovetail shaped of 6D of push rod 6 hypomeres crosses the transverse process 9B of pull bar 9, the stenosis 6E of push rod 6 can be limited in the position below the pull bar transverse process 9B, push rod 6 can not be pulled out again, push rod is fixed in the urceolus.

Fig. 7 be Medical safety syringe of the present invention after triggering, the entry needle the automatic recovery enters the push rod inner chamber and is in the structural representation of hold mode; In Fig. 6, because dissociating of front plug 7, spring 8 loses the constraint abrupt release, spring 8 shrinks, pulling force can drive needle stand 2 with front plug 7, needle tubing 1 together is incorporated into rapidly in the inner chamber of push rod 6, and (because the quality of front plug 7, needle stand 2, needle tubing 1 is very little, gross mass is less than 0.5g,) requirement is to elastic force: the pulling force of spring 8 is greater than the summation of front plug, needle stand, needle tubing quality, and pulling force is at 0.1～1.0N; The handle place sidewall that the transverse process 9B of push rod 9 is fixed on urceolus cracks in the 4C, and the front end of pull bar 9 and spring 8 are regained intracavity in the push rod fully with front plug 7, needle stand 2 and needle point 1; Because the total length of pull bar 9, spring 8, front plug 7, needle stand 2 and needle tubing 1 is less than the length of push rod inner chamber; When injection finished, push rod 6 was finished when triggering, and the distance that spring 8 is stretched is greater than the length of injection needle 1; Above condition can not expose after all can making entry needle (comprising needle point) be drawn into the push rod inner chamber, realizes security mask, prevents the purpose of stabbing.Simultaneously, the transverse process 9B that the narrow 6E of dovetail shaped of push rod 6 afterbodys cracks and crosses pull bar 9, push rod is limited in this place and can not again pulls out, and realizes disposable restriction.

Fig. 8 is the outer tube structure schematic diagram of the second embodiment of Medical safety syringe of the present invention; As seen from the figure, the front end of the leading portion 4E of urceolus 4 has the termination 4D of a undergauge, the external diameter that termination hollow and urceolus connect, its internal diameter is slightly larger than needle stand 2 stage casing 2B, the front end of termination 4D has a perforate, this aperture be slightly larger than needle stand 2 front end 2A external diameter but less than the external diameter of needle stand stage casing 2B; More than 2 times, the internal diameter of urceolus 4 leading portion 4E is slightly less than the internal diameter in urceolus 4 stage casings to the length of the endoporus of urceolus 4 leading portion 4E, also is slightly less than the external diameter of damped ring 3 greater than the thickness of damped ring 3; The outside crimping in the rear end of urceolus 4 forms handle 4B, the outer tube wall periphery that links to each other with handle 4B enlarges, form the back segment of urceolus, the sidewall of urceolus back segment has the 4C that vertically cracks, its width and highly all be slightly larger than pull bar 9 transverse process 9B thickness and the height, this 4C that cracks can form chimeric with the transverse process 9B of pull bar 9.

Fig. 9 is the structural representation after the urceolus 4 of the second embodiment of Medical safety syringe of the present invention is installed with needle stand 2, needle tubing 1, damped ring 3; The front end 2A of bonding needle tubing 1, needle stand 2 is installed in the front perforate of termination 4D of outer cylinder front end in needle stand 2 endoporus, the back segment 2C appearance of needle stand 2 suit damped ring 3, and damped ring 3 is compressed to be installed in the endoporus of urceolus leading portion 4E, forms closely chimeric with inwall.

The needle assembly that above-mentioned urceolus and needle stand, needle tubing, damped ring form, cooperate with the push-rod assembly of first embodiment of the invention, consist of the complete safety syringe construction of the second embodiment of the present invention, using method is identical with the first embodiment with safety protection function.

Because the present invention has adopted, damped ring in the process of push rod with its reach, only need to overcome damped ring to the frictional force of needle stand and outer tube inner wall (or outer hoop inwall) to the restriction of needle stand; Then, along with pushing away before the push rod continuation, as long as can overcome front plug by the fastening force of push rod front end endoporus annular projection, can realize definite triggering of the present invention, start spring and discharge.This triggering power (less than 20N) is far smaller than the in the past restriction of safety injector security feature tripping force (greater than 40N), can accomplish that low tripping force triggers, and is basically identical with the clinical injection operating physical force, uses comfortablely, meets the treatment operating routine.

Technical scheme described in the invention by any similar distortion that distortion can realize, all will fall into technology category of the present invention at those skilled in the art.

Claims (10)

1. Medical safety syringe is made of jointly needle assembly, injector assembly, entry needle the automatic recovery protector; It is characterized in that: entry needle the automatic recovery protector is comprised of with pull bar (9) front plug (7), spring (8); Again

Needle assembly is made of jointly outer hoop (10), needle tubing (1), needle stand (2), sealing ring (3); Again

Injector assembly is comprised of urceolus (4), push rod (6), piston (5).

2. said Medical safety syringe according to claim 1, it is characterized in that: spring (8) is an extension spring, the exhibition coiling is dredged in the end, two ends, the pitch of two ends (8A) can with the thread pitch coupling of front plug (7) rear end and pull bar (9) front end; The diameter of spring (8) is less than the diameter of push rod (6) inner chamber and front plug (7) and pull bar (9); The pulling force of spring (8) is greater than the summation of front plug (7) with needle stand (2) and needle tubing (1) quality, at 0.1～1.0N.

3. said Medical safety syringe according to claim 1, it is characterized in that: at urceolus (4) front end endoporus screw thread (4A) is arranged, the rear end crimping of urceolus forms handle (4B), expand outwardly with the outer tube wall of handle joint, form the hypomere of urceolus, sidewall at the urceolus hypomere has one vertically crack (4C), this width that cracks is slightly larger than the thickness of the transverse process (9B) of pull bar, this height that cracks is slightly larger than the height of the transverse process (9B) of pull bar, and this crack (4C) can be with transverse process (9B) build-in of pull bar.

4. said Medical safety syringe according to claim 3, it is characterized in that: urceolus (4) hollow, the length of the leading portion of urceolus (4E) is greater than more than 2 times of thickness of damped ring (3), and the internal diameter of the leading portion of urceolus (4E) is slightly less than the internal diameter of urceolus (4) stage casing and hypomere; The front end of urceolus leading portion (4E) has the termination (4D) of undergauge, and the internal diameter of termination is greater than the external diameter of needle stand stage casing (2B), and the antetheca of termination (4D) has perforate, and this aperture is slightly larger than the external diameter of needle stand (2) epimere (2A).

5. said Medical safety syringe according to claim 1, it is characterized in that: the front end of front plug (7) is wedge shape and expands protuberance (7A), can be chimeric with the lower end endoporus annular projection of needle stand (2), there is external screw thread (7A) rear end of front plug (7), the pitch of its pitch, external diameter and both ends of the spring (8A), internal diameter identical match, can form spin fastening.

6. said Medical safety syringe according to claim 1, it is characterized in that: pull bar (9) is the L structure, its front end has an external screw thread (9A), and its pitch, external diameter are identical with two ends pitch, the internal diameter coupling of spring (8), mutually can form spin fastening; The L shape transverse process (9B) that the tail end of pull bar (9) is rolled over once, the crack width of (6D) of the sidewall that its thickness is slightly less than push rod (6), the sidewall that also is slightly less than urceolus (4) the hypomere expansion width of (4C) that cracks, the height of transverse process (9B), the sidewall that also is slightly less than urceolus (4) the hypomere expansion height of (4C) that cracks.

7. said Medical safety syringe according to claim 1, it is characterized in that: pull bar (9) connect with spring (8), front plug (7) spin fastening, front plug (7) is installed in push rod (6) the front end endoporus, (6A) is fastening by the annular projection in the push rod endoporus, the transverse process (9B) of pull bar (9) passes crack (6D) of push rod sidewall, and the sidewall that is inlaid in urceolus (4) rear end expansion cracks in (4C).

8. said Medical safety syringe according to claim 1, it is characterized in that: push rod (6) is tubular structure, its front end appearance has a ring-shaped groove (6B), its front end internal orifice dimension is minimum, and the front aperture inwall has an annular projection (6A), and the putting back-end tube wall is rolled up outward and formed handle (6C); Sidewall at the stage casing of push rod and back segment has symmetrical two vertically crack (6D), near the cracking of crimping place, has to be the position limiting structure that dovetail shaped (6E) constriction changes.

9. said Medical safety syringe according to claim 1, it is characterized in that: outer hoop (10) is medicated cap shape hollow structure, outer hoop (10) appearance has screw thread (10B); The leading portion of outer hoop porose (10A), the aperture is greater than the external diameter of needle stand leading portion (2A), in the outer hoop, back segment hollow, the stage casing internal orifice dimension of outer hoop is greater than the external diameter of needle stand stage casing (2B), the internal diameter of the back segment endoporus (10C) of outer hoop is slightly less than the external diameter of damped ring (3), and the length of the back segment endoporus (10C) of outer hoop (10) is greater than more than 2 times of damped ring (3) thickness.

10. said Medical safety syringe according to claim 1, it is characterized in that: the pulling force of spring (8) is greater than the quality summation of front plug, needle stand, needle tubing; Total length after pull bar (9), spring (8), front plug (7), needle stand (2), needle tubing (1) serial connection is less than the length of push rod (6) inner chamber; When injection finished, the distance that push rod (6) is finished when triggering, spring (8) is stretched was greater than the length of injection needle (1).

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