CN220175769U - Injector assembly and injection device - Google Patents

Abstract

The utility model belongs to the field of medical equipment, and particularly relates to an injector assembly and an injector device, wherein the injector assembly is used for being matched with an injector main body, a push rod for pushing an injection piston is in a locking state before injection, at the moment, a limit structure is limited to move towards the far end of a shell by the push rod, in the use process, the push rod is unlocked, the piston is pushed by the push rod, injection of liquid medicine is completed, after injection is completed, and a needle head is pulled out, as the push rod is unlocked from the shell, the far end of a sleeve is not acted by external force, the limit structure moves towards the far end of the shell under the action of a first elastic piece, the limit structure is pushed towards the far end of the needle head, when the sleeve moves to cover the needle head, the limit structure is limited in the shell in the axial direction of the shell, and is locked between the limit structure and the shell, so that disposable use of the injector device can be realized, and meanwhile, the hidden danger that the needle head punctures a patient to cause secondary infection after use is avoided.

Description

Injector assembly and injection device

Technical Field

The utility model relates to the technical field of medical equipment, in particular to an injector assembly and an injector device.

Background

The prefilled syringe has great demands in the medicine market due to the characteristics of small size, convenient carrying, accurate and reliable administration, low pollution risk and the like, and the representative product of the prefilled syringe mainly comprises an insulin prefilled syringe. With the rapid development of modern biomedical technology, self-administration is widely used for treating chronic disease patients. At present, the composition is widely applied to the fields of antithrombotic medicines, vaccines, blood stimulators, interferon, rheumatoid arthritis and the like.

Because the prefilled syringe is self-injected after the patient self-purchases, the prefilled syringe or prefilled card bottle which is not treated by standard medical waste is discarded after the use, if the prefilled syringe or prefilled card bottle is not destroyed, the used disposable syringe is illegally collected, and flows into the medical market again after simple treatment and packaging, so that the possibility of being reused by some people who are in favor of illegal interests often exists, and great hidden danger is left for virus cross infection, disease transmission and the like; second, some syringes are prone to pricking the user during the process of assembly of the needle cap and needle, as the needle is exposed or the user is required to cap the needle, and also pose a risk of infection.

Disclosure of Invention

The embodiment of the utility model provides an injector assembly and an injector device, which aim to solve the technical problems that in the prior art, an injector does not have the performance of truly disposable use and the needle is stabbed after use to hurt a patient so as to cause secondary infection.

To this end, according to one aspect of the present utility model, there is provided an injector assembly for use with an injector body including a barrel containing a medical fluid, a piston engaged with the barrel, and a needle disposed at a distal end of the barrel, the injector assembly comprising:

a housing having an axial direction, said barrel being securable within said housing and said needle being extendable from said housing via a distal end of said housing;

the driving assembly comprises a push rod, wherein the push rod is arranged in the shell, the length direction of the push rod is parallel to the axial direction of the shell, the push rod is provided with a locking state connected with the shell and an unlocking state disconnected with the shell, the push rod is static relative to the shell in the locking state, and in the unlocking state, the push rod can move towards the far end of the shell and push the piston;

the limiting assembly is arranged in the shell and comprises a limiting structure and a first elastic piece, the limiting structure is sleeved on the push rod, and the first elastic piece is arranged between the limiting structure and the shell and provides acting force for the limiting structure to move towards the far end of the shell;

a guard assembly disposed within a distal end of the housing, the guard assembly including a sleeve slidably coupled to the housing, the sleeve being axially movable relative to the housing;

wherein when the push rod is in the locking state, the push rod limits the limiting structure to move towards the distal end of the shell, and the sleeve can move along the axial direction of the shell so as to cover the needle or enable the needle to be exposed from the distal end of the sleeve; when the push rod is in the unlocking state and the distal end of the sleeve is not acted by external force, the limiting structure can move towards the distal end of the shell and push the sleeve to move towards the distal end of the needle under the action of the first elastic piece, and when the sleeve moves to cover the needle, the limiting structure is limited in the shell in the axial direction of the shell.

Optionally, the push rod comprises a rod body and a stop part protruding on the circumferential side wall of the rod body; the limiting structure comprises a lantern ring which is sleeved on the rod body in a sliding mode and is located between the stopping part and the proximal end of the rod body, and an abutting part which is connected with the lantern ring and extends towards the distal end of the shell, when the push rod is in the locking state, the proximal end of the stopping part abuts against the distal end of the lantern ring, and therefore the limiting structure is limited to move towards the distal end of the shell.

Optionally, a protrusion is disposed on one of the inner wall of the housing and the abutting member, a groove is disposed on the other one of the inner wall of the housing and the abutting member, and the limiting structure can move to the distal end of the housing to the protrusion and the groove in a clamping manner under the action of the first elastic member when the push rod is in the unlocking state, so that the limiting structure is limited in the housing in the axial direction of the housing.

Optionally, the proximal end of the rod body is connected with a hook capable of elastically moving relative to the rod body, the proximal end of the housing is provided with a clamping hole, and the hook can pass through the clamping hole and hook the housing so as to enable the push rod to be in the locking state; the clamping hook can be separated from the shell under the action of external force, so that the push rod is switched from the locking state to the unlocking state.

Optionally, the driving assembly further includes an unlocking switch and a second elastic member, where the unlocking switch is provided on the housing and is capable of moving relative to the housing, so as to act on the push rod in the locked state and disconnect the push rod from the housing, and the second elastic member is provided between the push rod and the housing, and is used to provide a force for the push rod to move toward the distal end of the housing.

Optionally, a guiding groove is formed in the inner wall of the proximal end of the housing, a guiding piece in sliding fit with the guiding groove is arranged on the side wall of the unlocking switch, the guiding groove is at least provided with a locking position, a turning position and an unlocking position in sequence on a moving path of the guiding piece, and when the guiding piece is located at the locking position and in the process of moving from the locking position to the turning position, the unlocking switch is limited at the housing in the axial upper limit of the housing; when the guide piece moves from the turning position to the unlocking position, the distal end of the unlocking switch can act on the push rod in the locking state so as to disconnect the push rod from the shell.

Optionally, the guard assembly further comprises a third resilient member disposed between the sleeve and the housing for providing a force to the sleeve to move distally of the needle to cover the needle.

Optionally, the shell includes first casing and the second casing that is the tube-shape, the distal end of first casing with the proximal end of second casing is connected, under the locking state, the proximal end of push rod with the proximal end of first casing is connected, be provided with in the second casing and be used for with the cylinder is fixed in fixed subassembly in the second casing, the protection component set up in the second casing.

Optionally, the syringe assembly further comprises a needle cap for covering the needle, and a protective cap having a proximal end detachably connected to the distal end of the housing, the protective cap being for protecting the needle cap and the sleeve.

According to another aspect of the present utility model there is provided an injection device comprising a syringe body and a syringe assembly as described above, the syringe body fitting within the housing.

The injector assembly and the injection device provided by the utility model have the beneficial effects that: compared with the prior art, the injector assembly is in a locking state before injection, the push rod for pushing the piston is in a locking state, at the moment, the limiting structure moves towards the far end of the shell, the limiting structure does not act on the sleeve, the sleeve can move along the axial direction of the shell to cover the needle or enable the needle to be exposed out of the far end of the sleeve, in the use process, the far end of the sleeve is propped against an injected part to retract into the shell, the needle is exposed and pricked into the injected part, the push rod is unlocked, the piston is propped by the push rod, after injection is completed, the needle is pulled out, because the push rod is unlocked with the shell, the far end of the sleeve is not acted by external force, the limiting structure is propped against the sleeve to move towards the far end of the needle in the moving process, when the sleeve moves to cover the needle, the limiting structure is positioned in the shell at the upper axial limit of the shell, at the moment, the limit of the near end of the sleeve is not capable of moving towards the near end of the shell, and can not be used again, the needle is prevented from being pricked into the near end of the shell, and the needle can not be used again, and the needle can be pricked by a patient after the needle is used for a patient, and the needle is prevented from being pricked.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Wherein:

FIG. 1 is a schematic perspective view of an injection device according to an embodiment of the present utility model;

FIG. 2 is a schematic perspective view of the injection device of FIG. 1 with the protective cap and needle cap removed;

FIG. 3 is an exploded view of the injection device of FIG. 1;

FIG. 4 is a schematic cross-sectional view of an injection device according to an embodiment of the present utility model in an initial state;

FIG. 5 is a schematic perspective view of an unlocking switch of a drive assembly of an injection device shown in an embodiment of the present utility model, removed from a proximal end of a housing;

FIG. 6 is a schematic cross-sectional view of an injection device according to an embodiment of the present utility model showing the needle penetrating the injection site and the plunger in a locked position;

FIG. 7 is a schematic perspective view of the injection device of FIG. 6 with the first housing removed;

FIG. 8 is a schematic cross-sectional view of the injection device of FIG. 6 after the needle has been inserted into the site to be injected and the plunger has been pushed against the plunger to complete the injection;

FIG. 9 is a schematic cross-sectional view of the injection device of FIG. 6 after injection and needle withdrawal;

FIG. 10 is a schematic perspective view of the injection device of FIG. 9 with the first housing removed;

FIG. 11 is a schematic perspective view of a push rod and a limiting structure according to an embodiment of the present utility model;

FIG. 12 is a schematic view in partial cross-section of a securing assembly of an injection device for securing a syringe within a second housing according to an embodiment of the present utility model;

FIG. 13 is a schematic view showing a connection structure between the fixing assembly and the cylinder according to an embodiment of the present utility model;

fig. 14 is a schematic view showing the connection between the protective cap and the needle cap according to an embodiment of the present utility model.

Description of main reference numerals:

10. a syringe body;

11. a needle cylinder; 1111. a flange;

12. a piston;

13. a needle;

100. a housing;

110. a housing; 1101. a position mark; 1102. a guide groove; 1103. a guide groove; 11031. a locking position; 11032. turning the position; 11033. unlocking the position; 111. a clamping groove; 112. a connecting plate;

1121. a clamping hole; 113. a convex rib;

120. a second housing; 121. a boss; 122. a groove; 1201. a guide groove; 1202. a first fixing hole; 1203. a second fixing hole;

200. a drive assembly;

210. a push rod; 211. a rod body; 212. a stop portion; 2121. a limit groove; 213. a clamping hook;

220. unlocking the switch; 221. a guide; 222. a circumferential projection; 223. a frustum; 2201. an indication arrow;

230. a second elastic member;

300. a limit component;

310. a limit structure; 311. a collar; 31101. an annular groove; 3111. a slide block; 312. against

A top piece; 3121. a protrusion;

320. a first elastic member;

400. a protective assembly;

410. a sleeve; 411. a guide protrusion; 412. a convex portion;

420. a third elastic member;

500. a fixing assembly;

510. a bracket; 5101. avoidance holes; 511. a first bump;

520. a pressing plate; 5201. a through hole; 521. a second bump;

600. a needle cap;

700. protective cap.

Detailed Description

In order that the utility model may be readily understood, a more complete description of the utility model will be rendered by reference to the appended drawings. Preferred embodiments of the present utility model are shown in the drawings. This utility model may, however, be embodied in many other different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience in describing and simplifying the description based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the utility model.

Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", or a third "may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model.

It should be further noted that, in the embodiments of the present utility model, the same reference numerals denote the same components or the same parts, and for the same parts in the embodiments of the present utility model, reference numerals may be given to only one of the parts or the parts in the drawings, and it should be understood that, for other same parts or parts, the reference numerals are equally applicable.

In addition, the terms "proximal" and "distal" are defined as terms commonly used in the medical field. Specifically, the "distal end" is the end proximal to the injection site of the subject and the "proximal end" is the end distal to the injection site of the subject. For ease of understanding, the proximal end is shown in fig. 1 and 2 with reference numeral a and the distal end is shown in fig. 1 and 2 with reference numeral B.

According to one aspect of the present utility model, an embodiment of the present utility model provides an injector assembly for use with an injector body 10, as shown in fig. 1-3, the injector body 10 comprising a barrel 11 containing a medical fluid, a plunger (located inside the barrel 11, not shown) engaged with the barrel 11, and a needle 13 disposed at a distal end of the barrel 11, the injector assembly comprising a housing 100, a drive assembly 200, a stop assembly 300, and a shield assembly 400. Housing 100 has an axial direction, barrel 11 can be secured within housing 100, and needle 13 can extend from housing 100 through the distal end of housing 100. The driving assembly 200 includes a push rod 210, the push rod 210 being disposed in the housing 100 and a length direction of the push rod 210 being parallel to an axial direction of the housing 100, the push rod 210 having a locked state connected with the housing 100, in which the push rod 210 is stationary with respect to the housing 100, and an unlocked state disconnected from the housing 100, in which the push rod 210 is capable of moving distally of the housing 100 and pushing against the piston. The limiting assembly 300 is disposed in the housing 100, the limiting assembly 300 includes a limiting structure 310 and a first elastic member 320, the limiting structure 310 is sleeved on the push rod 210, the first elastic member 320 is disposed between the limiting structure 310 and the housing 100, and provides a force for moving the limiting structure 310 toward the distal end of the housing 100, where the first elastic member 320 may use a spring, a tension spring, a shrapnel, and other components with elastic properties. The guard assembly 400 is disposed within the distal end of the housing 100, the guard assembly 400 including a sleeve 410 slidably coupled to the housing 100, the sleeve 410 being axially movable relative to the housing 100.

Wherein, when the push rod 210 is in the locked state, the push rod 210 limits the distal movement of the limiting structure 310 to the outer shell 100, and the sleeve 410 can move along the axial direction of the outer shell 100 so as to cover the needle 13 or expose the needle 13 from the distal end of the sleeve 410; when the push rod 210 is in the unlocked state and the distal end of the sleeve 410 is not acted by an external force, the limiting structure 310 can move towards the distal end of the housing 100 and push the sleeve 410 to move towards the distal end of the needle 13 under the action of the first elastic element 320, and when the sleeve 410 moves to cover the needle 13, the limiting structure 310 is limited in the housing 100 in the axial direction of the housing 100.

In the embodiment of the present utility model, when the syringe assembly is used in combination with the syringe main body 10, before injection, as shown in fig. 4, the push rod 210 for pushing the injection piston 12 is in a locked state, at this time, the push rod 210 limits the movement of the limit structure 310 towards the distal end of the outer casing 100, the limit structure 310 does not act on the sleeve 410, the sleeve 410 can move along the axial direction of the outer casing 100 to cover the needle 13 or expose the needle 13 from the distal end of the sleeve 410, in the use process, the distal end of the sleeve 410 abuts against the injected part (the injected part can be the position of the arm, the hip or the waist of a human body or the like) and then retracts into the outer casing 100 (as shown in fig. 6), so that the needle 13 is exposed and pricked into the injected part, as shown in fig. 8, the push rod 210 abuts against the piston 12 in the needle cylinder 11, after the injection is completed and the needle 13 is pulled out, because the push rod 210 is unlocked with the outer casing 100 and the distal end of the sleeve 410 is not acted by external force, the limit structure 310 moves towards the distal end of the outer casing 100 under the action of the first elastic piece 320, in the process, the distal end of the sleeve 410 abuts against the injected part of the injected part (the injected part can not be the arm, buttocks or waist of the animal or the like) and the like) is retracted into the outer casing 100 (as shown in fig. 6), so that the needle 13 cannot be blocked by the axial direction when the sleeve 13 is prevented from being blocked, and the needle 13 is prevented from moving towards the outer casing 100, and the needle 13 is prevented from being blocked from moving towards the outer casing 100, and the needle 13 is prevented from being blocked by the needle 13.

In addition, compared with the existing full-automatic injector, the injector assembly has the characteristics of relatively fewer parts and simple structure, so that the manufacturing and using costs can be reduced. The existing full-automatic injector adopts a two-step structure in the use process, after the needle is pressed into the body, the injection of the liquid medicine is directly started, because some liquid medicine can cause pain and other stimulations on the injected part in the injection process, if a patient is easy to generate stress reaction on the injection liquid medicine under the premise of not being prepared for care, the needle is pulled out when the liquid medicine is being injected, so that the disposable injector cannot be used, the injection process is influenced, and economic waste is caused.

It should be noted that the syringe body 10 to which the syringe assembly is applicable includes, but is not limited to, a cartridge-type syringe and a prefilled syringe.

In one embodiment, as shown in FIG. 4, plunger 210 includes a shaft 211 and a stopper 212 protruding from a circumferential sidewall of shaft 211, with a distal end of shaft 211 extending into barrel 11 and contacting a proximal end of piston 12; the limiting structure 310 includes a collar 311 slidably sleeved on the rod body 211 and located between the stopper 212 and the proximal end of the rod body 211, and an abutment member 312 connected to the collar 311 and extending toward the distal end of the housing 100, where the abutment member 312 is located between the rod body 211 and the inner wall of the housing 100 and is used to push the proximal end of the sleeve 410 in the axial direction of the housing 100, and when the push rod 210 is in the locked state, the proximal end of the stopper 212 abuts against the distal end of the collar 311 to limit the distal movement of the limiting structure 310 toward the housing 100.

The push rod 210 and the limiting structure 310 are arranged as above, the structure is simple, and through the mutual matching of the stop part 212 and the lantern ring 311, the limiting structure 310 can be limited in the movement towards the distal end when the push rod 210 is in a locking state, and the limiting structure 310 is released in the movement towards the distal end after the push rod 210 is unlocked.

Specifically, in one implementation, as shown in fig. 11, the stop portion 212 is a protrusion protruding from a side wall of the rod body 211 around a circumference of the rod body 211, so that when the push rod 210 is in a locked state, a supporting force of the stop portion 212 on the collar 311 can be improved, and a force is uniformly applied between the stop portion and the collar. Of course, in other implementations, the stop 212 may also be a columnar or block-shaped protrusion protruding from the sidewall of the rod 211 at intervals around the circumference of the rod 211.

As shown in fig. 4, the first elastic member 320 is a spring, the spring is sleeved on the rod body 211, and the distal end of the spring abuts against the proximal end of the collar 311, and the proximal end of the spring abuts against the proximal end face of the housing 100. To enhance the stability of the spring, the proximal end of collar 311 is also provided with a ring groove 31101 for receiving the end of the spring, as shown in fig. 11.

Further, a sliding block 3111 is disposed on a circumferential side wall of the collar 311, a guide slot 1102 extending along an axial direction is disposed on an inner wall of the housing 100, and the sliding block 3111 is slidably matched with the guide slot 1102, so as to perform a guiding function on the limit structure 310 in a distal movement process towards the housing 100, so that the limit structure can only perform axial movement along the housing 100.

In a specific embodiment, as shown in fig. 9 and 10, the abutment member 312 is provided with a protrusion 3121, the inner wall of the housing 100 is provided with a groove 122, and when the push rod 210 is in the unlocked state, the limiting structure 310 can move towards the distal end of the housing 100 under the action of the first elastic member 320 until the protrusion 3121 is engaged with the groove 122, so that the limiting structure 310 is located in the housing 100 at the upper limit of the axial direction of the housing 100.

Axial limiting between the limiting structure 310 and the casing 100 is achieved through mutual clamping of the protrusion 3121 and the groove 122, and further relative locking among the casing 100, the limiting structure 310 and the sleeve 410 is achieved after injection is completed and the needle is pulled out, so that the principle is simple, and the structure is reliable.

Specifically, as shown in fig. 9 and 11, the propping members 312 are elongated and can be elastically deformed in a direction perpendicular to the length of the propping members, the number of the propping members 312 is multiple, the propping members 312 are distributed on the collar 311 at intervals, a protrusion 3121 is disposed on one side of each propping member 312 facing the inner wall of the housing 100, correspondingly, a plurality of grooves 122 are disposed on the inner wall of the housing 100 at intervals along the circumferential direction, and in the unlocked state of the push rod 210, the limiting structure 310 can move to the distal end of the housing 100 to the protrusions 3121 on each propping member 312 under the action of the first elastic member 320, and are in one-to-one corresponding clamping connection with the grooves 122 on the inner wall of the housing 100, so that the relative locking strength between the housing 100 and the limiting structure 310 can be enhanced.

In another specific embodiment, not shown in the drawings, the protrusion on the abutment member and the groove on the inner wall of the housing may be exchanged, i.e. the groove is provided on the abutment member, and the protrusion is provided on the inner wall of the housing, so that the protrusion can also function as in the above embodiment.

In a specific embodiment, as shown in fig. 4 and 5, a hook 213 capable of elastically moving relative to the rod body 211 is connected to the proximal end of the rod body 211, a clamping hole 1121 is provided on the proximal end of the housing 100, and the hook 213 can pass through the clamping hole 1121 and hook the housing 100, so that the push rod 210 is in a locked state; the hook 213 can be separated from the housing 100 under the action of an external force, so that the push rod 210 is switched from the locked state to the unlocked state.

Specifically, the connection plate 112 is integrally formed in the proximal end of the housing 100, the locking hole 1121 is formed in the connection plate 112, the locking hole 1121 is a fan-shaped hole, and in the locked state, the hook 213 at the proximal end of the rod body 211 passes through the locking hole 1121 and elastically hooks the proximal end of the connection plate 112, so that the housing 100 is connected with the push rod 210, so as to limit the displacement of the push rod 210 in the distal direction. Preferably, the plurality of the clamping holes 1121 is provided, and accordingly, the plurality of the clamping hooks 213 is provided, and the plurality of the clamping hooks 213 hook the connecting plate 112 through the plurality of clamping holes 1121 one by one, thereby improving the reliability of the connection between the push rod 210 and the housing 100 in the locked state.

In a more specific embodiment, as shown in fig. 3-5, the driving assembly 200 further includes an unlocking switch 220 and a second elastic member 230, wherein the unlocking switch 220 is provided on the housing 100 and is capable of moving relative to the housing 100 to act on the push rod 210 in the locked state and disconnect the push rod 210 from the housing 100, and the second elastic member 230 is provided between the push rod 210 and the housing 100 for providing a force to the distal movement of the push rod 210 toward the housing 100.

By providing the unlocking switch 220 and the second elastic member 230, a user can unlock the push rod 210 conveniently, and automatic injection is achieved.

It will be appreciated that, in the use process, as shown in fig. 6 and 7, when the needle 13 is pricked into the injected part, but the push rod 210 is not unlocked by the unlocking switch 220, the second elastic member 230 is in a compressed force-accumulating state, as shown in fig. 8, after the unlocking switch 220 is operated to disconnect the hook 213 at the proximal end of the push rod 210 from the connecting plate 112, the elastic potential energy accumulated by the second elastic member 230 is released, so as to push the push rod 210 to move distally, and the push rod 210 moves to push the piston 12 in the syringe 11 to squeeze the liquid medicine in the syringe 11, so that the liquid medicine is injected into the injected part through the needle 13, thereby realizing automatic injection.

Specifically, the second elastic member 230 may be a spring, a tension spring, a shrapnel, or the like having elasticity. As shown in fig. 6 and 8-10, in the present embodiment, the second elastic member 230 is a spring, which is sleeved on the rod 211 between the stop 212 and the proximal end of the rod 211, and the distal end of the spring abuts against the proximal end of the stop 212 and the proximal end of the spring abuts against the distal end of the connecting plate 112. To improve the stability of the spring, the proximal end of the stop 212 is further provided with a ring of stop slots 2121 for receiving the ends of the spring, as shown in fig. 11.

In a further specific embodiment, as shown in fig. 5, the inner wall of the proximal end of the housing 100 is provided with a guide groove 1103, the side wall of the unlocking switch 220 is provided with a guide piece 221 slidably fitted with the guide groove 1103, the guide groove 1103 has at least a locking position 11031, a turning position 11032 and an unlocking position 11033 in sequence on the moving path of the guide piece 221, and the unlocking switch 220 is located at the housing 100 at the upper limit in the axial direction of the housing 100 when the guide piece 221 is located at the locking position 11031 and during the movement from the locking position 11031 to the turning position 11032; during the movement of the guide 221 from the turning position 11032 to the unlocking position 11033, the distal end of the unlocking switch 220 can act on the push rod 210 in the locked state to disconnect the push rod 210 from the housing 100.

Specifically, the guide groove 1103 includes a mounting section, which communicates with the proximal end of the housing 100 in order, a circumferential rotation section, which extends circumferentially on the inner wall of the housing 100 for rotating the unlocking switch 220 in the circumferential direction, and an axial guide section, which extends axially on the inner wall of the housing 100 for pressing the unlocking switch 220 in the axial direction, which communicates with the proximal end of the housing 100 for facilitating assembly, and the guide 221 on the unlocking switch 220 enters the guide groove 1103. The connection part of the mounting section and the circumferential rotation section forms the locking position 11031, the connection part of the circumferential rotation section and the axial guiding section forms the turning position 11032, and one end of the axial guiding section, which is far away from the circumferential rotation section, forms the unlocking position 11033.

The unlocking switch 220 is of a cap-shaped structure, a frustum 223 protruding towards the distal end is arranged in the unlocking switch, a circumferential protrusion 222 is arranged on the outer circumference of the distal end of the unlocking switch 220, and a guide piece is arranged on the circumferential protrusion 222. The unlocking switch 220 is adapted to be pressed in the shell 100, the convex rib 113 is arranged on the inner wall of the proximal end of the shell 100 in a protruding mode, the convex rib 113 and the connecting plate 112 are arranged at intervals in the circumferential direction of the shell 100, the circumferential protrusion 222 on the unlocking switch 220 is limited between the connecting plate 112 and the convex rib 113 on the shell 100, and the unlocking switch 220 is prevented from falling off the shell 100. The frustum 223 is used for cooperating with the hook 213 at the proximal end of the push rod 210 to apply a force to the hook 213, so that the hook 213 is elastically deformed, and the push rod 210 is unlocked.

Further, as shown in fig. 1 and 5, a position mark 1101 is provided ON the outer wall of the proximal end of the housing 100, which is shown as ON and OFF, an indication arrow 2201 is provided ON the outer wall of the unlocking switch 220, and when the indication arrow 2201 points to OFF, the guide 221 is located at a locking position 11031 in the guide groove 1103, and at this time, the unlocking switch 220 cannot be pressed; when the unlocking switch 220 is turned and the indication arrow 2201 points to ON, the guide piece 221 is located at the turning position 11032 in the guide groove 1103, at this time, the unlocking switch 220 is pressed, the guide piece 221 moves from the turning position 11032 to the unlocking position 11033 along the axial guide section, the unlocking switch 220 applies force to the clamping hook 213 clamped ON the connecting plate 112, so that the clamping hook 213 is elastically deformed, and is separated from the connecting plate 112, and unlocking of the push rod 210 is achieved.

In one embodiment, as shown in fig. 3 and 4, shield assembly 400 further includes a third spring 420 disposed between sleeve 410 and housing 100 for providing sleeve 410 with a force to move distally of needle 13 to cover needle 13.

Under the elastic force of the third elastic member 420, the sleeve 410 always covers the needle 13 therein before and after injection, and can play a role of protecting the needle 13.

In use, a user holds the housing 100, as shown in fig. 4, to place the distal end of the sleeve 410 against the site to be injected, to retract the sleeve 410 into the housing 100 against the elastic force of the third elastic member 420, and to extend the needle 13 from the distal end of the sleeve 410 and gradually penetrate the site to be injected. In the process of injecting the medical fluid, as shown in fig. 8, the third elastic member 420 is in a state of being compressed and accumulated. After the injection is completed and the needle 13 is withdrawn, as shown in fig. 9 and 10, the sleeve 410 is moved toward the distal end of the needle 13 and finally covered on the needle 13 by the elastic force of the third elastic member 420.

Specifically, the third elastic member 420 may be a spring, a tension spring, a spring plate, or the like having elasticity. In this embodiment, the third elastic member 420 is a spring, the spring is sleeved between the syringe 11 and the sleeve 410, the distal end of the spring abuts against the protrusion 412 on the inner wall of the sleeve 410, and the proximal end of the spring abuts against the syringe 11. The proximal outer wall of the sleeve 410 is provided with a guide protrusion 411, a guide groove 1201 which is in sliding fit with the guide protrusion 411 is arranged in the housing 100, the guide groove 1201 extends along the axial direction of the housing 100, and the guide protrusion 411 and the guide groove 1201 cooperate to play a role in limiting and fixing, so that the sleeve 410 can only axially move in the housing 100. As shown in fig. 4 and 9, before use and after injection and withdrawal of the needle 13, the distal end of the guide projection 411 on the sleeve 410 is restrained by the distal groove wall of the guide groove 1201 on the housing 100, so that the sleeve 410 is restrained in the distal direction.

In one embodiment, as shown in fig. 1, 3 and 4, the housing 100 includes a cylindrical housing 110 and a second housing 120, a distal end of the housing 110 is connected to a proximal end of the second housing 120, a proximal end of the push rod 210 is connected to a proximal end of the housing 110 in a locked state, a fixing assembly 500 for fixing the syringe 11 in the second housing 120 is provided in the second housing 120, and the shielding assembly 400 is provided in the second housing 120.

The shell 100 is formed by connecting the shell 110 and the second shell 120, so that assembly of parts in the shell 100 is facilitated during assembly.

Specifically, the distal end of the housing 110 is provided with a clamping groove 111, the outer diameter of the proximal end of the second housing 120 is smaller than the inner diameter of the distal end of the housing 110, and the outer wall of the proximal end of the second housing 120 is convexly provided with a boss 121, and when assembled, the proximal end of the second housing 120 is inserted into the distal end of the housing 110 until the boss 121 is clamped into the clamping groove 111. The shell 110 is connected with the second shell 120 in a clamping manner, so that difficulty is increased for disassembly compared with detachable connection manners such as threaded connection and screw connection, the possibility of disassembly, reassembling and reuse after use is avoided, and disposable use performance is further guaranteed.

In a specific embodiment, as shown in fig. 4 and 12-13, the fixing assembly 500 includes a bracket 510 and a pressure plate 520, the middle part of the bracket 510 is provided with a relief hole 5101 for passing the syringe 11, the edge of the bracket 510 is provided with a first bump 511, the middle part of the pressure plate 520 is provided with a through hole 5201 for passing the push rod 210, the edge of the pressure plate 520 is provided with a second bump 521, the inner wall of the proximal end of the second housing 120 is provided with a first fixing hole 1202 and a second fixing hole 1203 at intervals in the axial direction, during assembly, the bracket 510 is firstly installed into the second housing 120 from the proximal end of the second housing 120, the first bump 511 at the edge of the bracket 510 is clamped into the first fixing hole 1202, then the syringe 11 is installed into the relief hole 5101 on the bracket 510 from the proximal end of the second housing 120, the flange 1111 at the proximal end of the syringe 11 is supported at the proximal end of the bracket 510, finally the pressure plate 520 is installed into the second housing 120 from the proximal end of the second housing 120, the second bump 521 at the edge of the pressure plate 520 is clamped into the second fixing hole 1203, and the proximal end 11 is pressed against the flange 1203 by the pressure plate 520 to press the proximal end 11 against the bracket 510.

Further, the first protrusion 511, the second protrusion 521, the first fixing hole 1202 and the second fixing hole 1203 are provided in plurality to improve the reliability of the fixation of the cylinder 11 in the second housing 120 by the fixing assembly 500.

In one embodiment, as shown in fig. 1 and 14, the syringe assembly further comprises a needle cap 600 and a protective cap 700, the needle cap 600 being adapted to be over the needle 13, the proximal end of the protective cap 700 being detachably connected to the distal end of the housing 100, the protective cap 700 being adapted to protect the needle cap 600 and the sleeve 410.

The needle 13 can be protected before use by the needle cap 600 and the protective cap 700, on the one hand, the needle 13 is protected from damage, and on the other hand, the needle 13 is covered to avoid pollution of the needle 13.

Further, the needle cap 600 is fixed inside the protective cap 700, and when the protective cap 700 is pulled out, the needle cap 600 is pulled out together, thereby facilitating the use.

According to another aspect of the present utility model, an embodiment of the present utility model also provides an injection device, as shown in fig. 1 to 10, comprising a syringe body 10 and a syringe assembly according to any of the above embodiments, the syringe body 10 being fitted within a housing 100.

The following describes the use of the injection device:

as shown in fig. 1-2 and fig. 4-5, in the initial state, the injection device is in a locked state, the guide of the unlocking switch 220 is located at the locking position 11031 of the guide groove 1103, and the unlocking switch 220 is in a pressing-immobilized state, so that abrupt injection caused by false touch is prevented. The unlocking switch 220 is rotated to rotate the guide member to the turning position 11032 of the guide groove 1103 to unlock, at this time, the unlocking switch 220 can move axially to the distal end, and then the protective cap 700 at the distal end of the housing 100 is pulled out after unlocking is completed, and when the protective cap 700 is pulled out, a needle cap (not shown in the figure) fixed inside the protective cap 700 is pulled out together, so that the injection can be pressed. It will be appreciated that during use, the protective cap 700 and the needle cap may be pulled out first, and then the unlocking switch 220 may be rotated to perform the above-described unlocking operation.

As shown in fig. 6, before injection, the distal end of the sleeve 410 abuts against the injected part and is pressed down, so that the sleeve 410 is compressed in the proximal direction, during the compression process, the guide protrusion 411 on the outer wall of the sleeve 410 moves in the distal direction along the guide groove 1201 on the inner wall of the housing 100, and simultaneously the third elastic member 420 is pressed, the needle 13 is exposed out of the sleeve 410 and directly pierces the injected part until the distal end of the sleeve 410 is flush with the distal end of the housing 100, at this time, the proximal end of the guide protrusion 411 on the outer wall of the sleeve 410 abuts against the distal end of the abutment member 312 of the limiting structure 310, so as to limit the limiting structure 310 to move in the distal direction, and at this time, injection can be achieved by pressing the unlocking switch 220.

As shown in fig. 8, when starting injection, the user presses the unlocking switch 220, the hook 213 at the proximal end of the push rod 210 is outwards spread by the frustum 223 on the unlocking switch 220, and the push rod 210 is released under the action of the second elastic member 230 with storage force, so that the push rod 210 moves in the distal direction, and the piston 12 in the syringe 11 is pushed, so that the liquid medicine is injected until the injection is completed.

As shown in fig. 9 and 10, after the injection is completed, the needle 13 is withdrawn. The sleeve 410 is ejected and covered on the needle 13 by the elastic force of the third elastic member 420, and the distal groove wall of the guide groove 1201 of the inner wall of the housing 100 abuts against the guide protrusion 411 on the outer wall of the sleeve 410, preventing the sleeve 410 from continuing to move distally. At this time, since the push rod 210 moves distally into the syringe 11 under the action of the second elastic element 230, the collar 311 of the limiting structure 310 is not limited in the distal direction any more, and the abutting element 312 abutting against the proximal end of the sleeve 410 moves distally under the action of the elastic force of the first elastic element 320 until moving to abut against the proximal end of the sleeve 410 again, so as to limit the abutting element 312 to move distally, and meanwhile, the protrusion 3121 on the abutting element 312 is clamped with the groove 122 on the inner wall of the housing 100, so that the limiting structure 310 is limited in the housing 100 in the axial direction of the housing 100, and the sleeve 410 cannot move proximally, so that the needle 13 cannot be exposed, and the needle 13 is protected and disposable.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of the utility model should be assessed as that of the appended claims.

Claims (10)

1. An injector assembly for use with an injector body comprising a barrel containing a medical fluid, a plunger engaged with the barrel, and a needle disposed at a distal end of the barrel, the injector assembly comprising:

a housing having an axial direction, said barrel being securable within said housing and said needle being extendable from said housing via a distal end of said housing;

the driving assembly comprises a push rod, wherein the push rod is arranged in the shell, the length direction of the push rod is parallel to the axial direction of the shell, the push rod is provided with a locking state connected with the shell and an unlocking state disconnected with the shell, the push rod is static relative to the shell in the locking state, and in the unlocking state, the push rod can move towards the far end of the shell and push the piston;

the limiting assembly is arranged in the shell and comprises a limiting structure and a first elastic piece, the limiting structure is sleeved on the push rod, and the first elastic piece is arranged between the limiting structure and the shell and provides acting force for the limiting structure to move towards the far end of the shell;

a guard assembly disposed within a distal end of the housing, the guard assembly including a sleeve slidably coupled to the housing, the sleeve being axially movable relative to the housing;

wherein when the push rod is in the locking state, the push rod limits the limiting structure to move towards the distal end of the shell, and the sleeve can move along the axial direction of the shell so as to cover the needle or enable the needle to be exposed from the distal end of the sleeve; when the push rod is in the unlocking state and the distal end of the sleeve is not acted by external force, the limiting structure can move towards the distal end of the shell and push the sleeve to move towards the distal end of the needle under the action of the first elastic piece, and when the sleeve moves to cover the needle, the limiting structure is limited in the shell in the axial direction of the shell.

2. The syringe assembly of claim 1, wherein the plunger comprises a stem body and a stop protruding from a circumferential sidewall of the stem body; the limiting structure comprises a lantern ring which is sleeved on the rod body in a sliding mode and is located between the stopping part and the proximal end of the rod body, and an abutting part which is connected with the lantern ring and extends towards the distal end of the shell, when the push rod is in the locking state, the proximal end of the stopping part abuts against the distal end of the lantern ring, and therefore the limiting structure is limited to move towards the distal end of the shell.

3. The syringe assembly of claim 2, wherein one of the inner wall of the housing and the abutment is provided with a protrusion, the other of the inner wall of the housing and the abutment is provided with a recess, and the limit structure is capable of moving toward the distal end of the housing under the action of the first elastic member until the protrusion is engaged with the recess in the unlocked state of the push rod, so that the limit structure is limited in the housing in the axial direction of the housing.

4. The syringe assembly according to claim 2, wherein a catch capable of elastically moving relative to the lever body is connected to a proximal end of the lever body, and a catch hole is provided at a proximal end of the housing, the catch being capable of passing through the catch hole and hooking the housing to place the push rod in the locked state; the clamping hook can be separated from the shell under the action of external force, so that the push rod is switched from the locking state to the unlocking state.

5. The syringe assembly of any one of claims 1-4, wherein the drive assembly further comprises an unlock switch disposed on the housing and movable relative to the housing to act on the plunger in the locked state and disconnect the plunger from the housing, and a second resilient member disposed between the plunger and the housing for providing a force to the plunger for distal movement of the housing.

6. The syringe assembly of claim 5, wherein the inner wall of the proximal end of the housing is provided with a guide slot, the side wall of the unlocking switch is provided with a guide member in sliding fit with the guide slot, the guide slot is provided with a locking position, a turning position and an unlocking position sequentially at least on the moving path of the guide member, and the unlocking switch is limited on the housing in the axial direction of the housing when the guide member is positioned at the locking position and moves from the locking position to the turning position; when the guide piece moves from the turning position to the unlocking position, the distal end of the unlocking switch can act on the push rod in the locking state so as to disconnect the push rod from the shell.

7. The syringe assembly of any one of claims 1-4, wherein the shield assembly further comprises a third resilient member disposed between the sleeve and the housing for providing a force to the sleeve to move distally of the needle to shield the needle.

8. The syringe assembly of any one of claims 1-4, wherein the housing comprises a first housing and a second housing having a tubular shape, a distal end of the first housing being coupled to a proximal end of the second housing, a proximal end of the push rod being coupled to the proximal end of the first housing in the locked condition, a securing assembly disposed within the second housing for securing the syringe within the second housing, and the shield assembly disposed within the second housing.

9. The syringe assembly of any one of claims 1-4, further comprising a needle cap for covering the needle and a protective cap having a proximal end detachably connected to a distal end of the housing, the protective cap for protecting the needle cap and the sleeve.

10. An injection device comprising a syringe body and a syringe assembly according to any one of claims 1 to 9, the syringe body fitting within the housing.