Drug mixing syringe

Abstract

The medicine mixing injector comprises a sleeve, a middle push rod assembly and a rear push rod assembly which are coaxially arranged in a sleeved mode from outside to inside, a medicine outlet hole is formed in the front end of the middle push rod, a matched sealing cover body is installed at the medicine outlet hole, the front end of the middle push rod, the cover body and the sleeve form a front closed cavity, and the front end of the rear push rod assembly, the cover body and the middle push rod form a rear closed cavity. The peripheral wall of the middle push rod is provided with an elastic part capable of being folded and expanded, in the initial position, the elastic part is in an expansion state of abutting against the rear end of the sleeve, and in the state, the rear push rod assembly can move forwards relative to the middle push rod and stops the elastic part from being folded, so that the middle push rod cannot move forwards relative to the sleeve. And when the rear push rod assembly moves forwards to the groove to be matched with the elastic part on the middle push rod, the elastic part can be folded and unblocked from the sleeve, and the middle push rod can move forwards relative to the sleeve. The invention provides the medicine mixing injector which can quickly and uniformly mix and inject two medicines and has higher safety and stability.

Description

Technical Field

[0001] The invention relates to a medicine mixing syringe and belongs to the technical field of medical equipment. Background Art

[0002] In the traditional injection operation process, the solvent (i.e., water for injection) must first be extracted with a syringe, and then the syringe needle must be inserted into a solute bottle (powder injection or water injection), and then the solvent and solute must be pushed out to mix and dissolve, and finally the mixed liquid medicine must be extracted into the syringe before it can be injected into the human body or added to the infusion bottle. This operation method is complicated, the workload of nurses is large, and the liquid medicine must be transferred several times, which is easy to be contaminated. For this reason, a disposable drug storage syringe such as the one disclosed in application number CN201410024549.4 has appeared. However, on the one hand, this syringe is difficult to quickly and evenly mix the medicine in the rear closed cavity when pushing the medicine into the front closed cavity. It is necessary to operate the push-pull rod A and the push-pull rod B at the same time, and the operation steps are relatively complicated. On the other hand, it is difficult to ensure that the push-pull rod A in the middle before injection will not move forward relative to the sleeve to cause premature injection, which reduces safety and stability. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a drug mixing syringe, which can facilitate the rapid and uniform mixing and injection of two drugs, and has greater safety and stability, and can solve the shortcomings of the prior art.

[0004] The technical scheme of the present invention is: a drug mixing syringe, comprising a sleeve, a middle push rod assembly, and a rear push rod assembly coaxially sleeved from outside to inside, the middle push rod assembly comprising a middle push rod and a piston body arranged on the outer wall of the middle push rod, the middle push rod is slidably connected in the sleeve through the piston body, and the rear push rod assembly is slidably connected in the middle push rod, the front end of the sleeve is provided with an injection port and a matching sealing member, the front end of the middle push rod is provided with a drug outlet hole, a matching sealing cover body is installed at the drug outlet hole, the front end of the middle push rod, the cover body and the sleeve form a front closed cavity, and the rear push rod The front end of the assembly, the cover body and the middle push rod form a rear closed cavity, and the peripheral wall of the middle push rod has an elastic part that can be folded and expanded. In the initial position, the elastic part is in an expanded state that resists the rear end of the sleeve. In this state, the rear push rod assembly can move forward relative to the middle push rod and block the elastic part from folding, so that the middle push rod cannot move forward relative to the sleeve. A groove is provided on the peripheral wall of the rear push rod assembly. When the rear push rod assembly moves forward until the groove cooperates with the elastic part on the middle push rod, the elastic part can fold and release the resistance with the sleeve, and the middle push rod can move forward relative to the sleeve.

[0005] Furthermore, the rear push rod assembly and the middle push rod have a matching connection structure. When the rear push rod assembly moves forward to the matching position between the groove and the elastic part on the middle push rod, the connection structure cooperates, and the rear push rod assembly and the middle push rod move forward together relative to the sleeve.

[0006] Further, the connection structure is that when the rear push rod assembly moves forward to a position where the groove cooperates with the elastic portion on the middle push rod, the rear push rod assembly is flush with the rear end of the middle push rod.

[0007] Furthermore, the rear end of the sleeve has an outwardly expanded gripping portion, the gripping portion has an outwardly expanded inner wall, and the elastic portion cooperates with the inner wall of the gripping portion to resist.

[0008] Furthermore, the rear push rod assembly includes a hollow rear push rod and a piston arranged at the front end of the rear push rod. The rear end of the middle push rod is expanded outward and has an expanded inner circumferential wall. A matching positioning mechanism is provided between the inner circumferential wall and the rear push rod. The rear push rod assembly is maintained in an initial position of sliding connection with the middle push rod through the cooperation of the positioning mechanism.

[0009] Furthermore, the inner wall of the sleeve is provided with an exhaust groove, and the exhaust groove is used for connecting the front sealing cavity with the outside.

[0010] By implementing the present invention, the front sealed chamber and the rear sealed chamber respectively contain two kinds of drugs to be mixed. In the initial state of the rear push rod assembly before it is pushed, the elastic part on the peripheral wall of the middle push rod is in an expanded state that resists the rear end of the sleeve, and the middle push rod cannot move forward relative to the sleeve to cause premature injection. When in use, the sleeve is held with one hand and the rear push rod assembly is pushed forward with the other hand. At this time, the rear sealed chamber is pressurized to open the cover body, and the front sealed chamber is connected with the rear sealed chamber. As the rear push rod assembly moves forward, the drugs in the rear sealed chamber are pushed into the front sealed chamber for mixing. In this process, the rear sealed chamber gradually becomes smaller until it disappears, and the pressure in the front sealed chamber increases, forcing the middle push rod to move backward. The volume of the sealed chamber is automatically expanded to accommodate the mixed medicine. After the medicine in the rear sealed chamber is pushed into the front sealed chamber, the rear push rod assembly is connected to the middle push rod. At this time, the elastic part on the peripheral wall of the middle push rod corresponds to the groove on the peripheral wall of the rear push rod assembly. When the two move forward relative to the sleeve together, the elastic part can be retracted inward when it contacts the inner wall of the sleeve to release the resistance with the sleeve, and can continue to move forward relative to the sleeve to complete the injection of the mixed medicine. The medicine in the rear sealed chamber can be quickly pushed into the front sealed chamber for mixing at one time. The operation is simple. At the same time, before the medicine is mixed, the middle push rod will not move forward relative to the sleeve to cause premature injection, thereby improving safety and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a three-dimensional schematic diagram of the initial state of the present invention;

[0012] Figure 2 It is a cross-sectional view of the present invention in its initial state;

[0013] Figure 3 for Figure 2 A magnified image of point A;

[0014] Figure 4 It is a cross-sectional view of the state in which the medicine in the rear sealed cavity of the present invention is pushed to the front sealed cavity;

[0015] Figure 5 This is a cross-sectional view of the injection state of the present invention.

[0016] As shown in the figure: sleeve 1; middle push rod 2; piston body 3; sealing member 4; medicine outlet hole 5; cover body 6; front sealed chamber 7; rear sealed chamber 8; elastic part 9; groove 10; rear push rod 11; piston 12; inner convex ring 13; outer convex ring 14; exhaust groove 15; grabbing part 16. DETAILED DESCRIPTION

[0017] Embodiments of the present invention: Figures 1 to 5 As shown, a drug mixing syringe comprises a sleeve 1, a middle push rod assembly and a rear push rod assembly which are coaxially sleeved from outside to inside. The middle push rod assembly comprises a middle push rod 2 and a piston body 3 arranged on the outer wall of the middle push rod 2. The middle push rod 2 is slidably connected in the sleeve 1 through the piston body 3, and the rear push rod assembly is slidably connected in the middle push rod 2. The front end of the sleeve 1 is provided with an injection port and a matching sealing member 4. The front end of the middle push rod 2 is provided with a drug outlet 5. The drug outlet 5 is provided with a matching sealing cover body 6. The front end of the middle push rod 2, the cover body 6 and the sleeve 1 form a front closed cavity 7. The front end of the rear push rod assembly, the cover body 6 and the middle push rod 2 form a rear closed chamber 8, and the front closed chamber 7 and the rear closed chamber 8 respectively contain two kinds of medicines to be mixed, such as a liquid medicine in the front closed chamber 7, and another liquid medicine or powder medicine in the rear closed chamber 8. The peripheral wall of the middle push rod 2 has an elastic part 9, and the elastic part 9 can expand and retract relative to the peripheral wall of the middle push rod 2. A groove 10 that cooperates with the elastic part 9 is provided on the peripheral wall of the rear push rod assembly. In the initial position, the elastic part 9 is in an expanded state that resists the rear end of the sleeve 1, and the peripheral wall of the rear push rod assembly will prevent the elastic part 9 from retracting. At this time, the rear push rod assembly can The middle push rod 2 moves forward relative to the sleeve 1, while the middle push rod 2 cannot move forward relative to the sleeve 1. During the process of the rear push rod assembly moving forward relative to the middle push rod 2, the rear sealed chamber 8 is pressurized to open the cover body 6, and the front sealed chamber 7 is connected to the rear sealed chamber 8. As the rear push rod assembly moves forward, the medicine in the rear sealed chamber 8 is completely pushed into the front sealed chamber 7 for mixing. During this process, the rear sealed chamber 8 gradually becomes smaller until it disappears, and the pressure in the front sealed chamber 7 increases, forcing the middle push rod 3 to move backward, and the volume of the front sealed chamber 7 is automatically expanded to accommodate the mixed medicine, and the medicine in the rear sealed chamber 7 is completely pushed into the front sealed chamber 7. When in the sealed cavity 8 (that is, when the rear sealed cavity 8 disappears), the elastic part 9 on the peripheral wall of the middle push rod 2 corresponds to the groove 10 on the peripheral wall of the rear push rod assembly. When the middle push rod 2 and the rear push rod assembly move forward relative to the sleeve 1, the elastic part 9 can be retracted inward when it contacts the inner wall of the sleeve 1 to release the resistance with the sleeve 1. The two can continue to move forward relative to the sleeve 1 to complete the injection of the mixed medicine, which is convenient for quickly and evenly mixing and injecting the two medicines. The operation is simple. At the same time, the medicines are not mixed, and the front middle push rod 2 will not move forward relative to the sleeve 1 to cause premature injection, which has better safety and stability.

[0018] As a preferred embodiment, the rear push rod assembly and the middle push rod 2 have a matching connection structure. When the rear push rod assembly moves forward to the matching position of the groove 10 and the elastic part 9 on the middle push rod 2, the connection structure cooperates. The connection structure can be a matching clamping structure or a resisting mechanism located between the rear push rod assembly and the middle push rod 2. When the rear push rod assembly moves forward relative to the middle push rod 2 to complete pushing the medicine in the rear sealed chamber 7 into the front sealed chamber 8 (that is, when the rear sealed chamber 8 disappears), when the elastic part 9 on the peripheral wall of the middle push rod 2 corresponds to the groove 10 on the peripheral wall of the rear push rod assembly, the connection structure connects the rear push rod assembly with the middle push rod 2, so that the two automatically move forward together relative to the sleeve 1 to realize the injection of the mixed medicine, and the injection operation is more convenient.

[0019] As a preferred embodiment, in order to facilitate production and installation, the connection between the middle push rod 2 and the rear push rod assembly is achieved through a simpler structure. When the rear end of the rear push rod assembly just completely enters the middle push rod 2, that is, the rear push rod assembly is flush with the rear end of the middle push rod 2, the groove 10 at the rear push rod assembly corresponds to the elastic part 9 on the middle push rod 2, and at this time, the two can be pushed forward together to realize the injection operation.

[0020] As a preferred embodiment, the rear end of the sleeve 1 has an outward-expanded grasping portion 16, and the grasping portion 16 has an outward-expanded inner wall. The elastic portion 9 cooperates with the inner wall of the grasping portion 16 to resist. The outward-expanded grasping portion 16 is convenient for holding and operation. When in use, one hand holds the grasping portion 16 and the other hand pushes the rear push rod assembly. The outward-expanded inner wall acts as a guide to facilitate the installation of the middle push rod assembly in the sleeve 1, and is also conducive to resisting and guiding the elastic portion 9, so that it can be retracted more smoothly.

[0021] As a preferred embodiment, the rear push rod assembly includes a hollow rear push rod 11 and a piston 12 arranged at the front end of the rear push rod 11. The rear end of the middle push rod 11 is expanded outward and has an expanded inner circumferential wall. A matching positioning mechanism is provided between the inner circumferential wall and the rear push rod 11. The positioning mechanism includes an inner convex ring 13 arranged on the inner circumferential wall at the rear end of the middle push rod 11 and an outer convex ring 14 on the circumferential wall of the rear push rod 11. The initial position is that the outer convex ring 14 is located behind the inner convex ring 12, which plays a certain role in blocking the forward movement of the rear push rod assembly 11 relative to the middle push rod assembly, thereby preventing misoperation. When the force pushing the rear push rod assembly 11 is large enough, the two will deform after resistance, so that the outer convex ring 14 rigidly passes through the inner convex ring 13 to realize the sliding of the rear push rod assembly relative to the middle push rod assembly, and the hollow rear push rod 11 makes it easy for the rear push rod 11 to deform so that it can pass smoothly, while also saving materials.

[0022] As a preferred embodiment, the inner wall of the sleeve 1 is provided with a plurality of exhaust grooves 15, and the exhaust grooves 15 are distributed axially along the sleeve 1 and connected with the outside. In the initial position, the front end of the exhaust groove 15 is located behind the piston body 3 of the middle push rod assembly. At this time, due to the obstruction of the piston body 3, the front sealed chamber 8 is in a sealed state not connected with the exhaust groove 15. When the medicine in the rear chamber closed chamber 8 is pushed into the front sealed chamber 7 for mixing, the middle push rod assembly moves backward to connect the front sealed chamber 8 with the exhaust groove 15. When the rear push rod assembly and the middle push rod assembly are pushed forward relative to the sleeve 1 to realize the injection of the mixed medicine, any air in the front sealed chamber 8 will be discharged from the exhaust groove 15 to realize automatic exhaust.

Claims

1. A drug mixing syringe, comprising a sleeve, a middle push rod assembly, and a rear push rod assembly coaxially sleeved from outside to inside, the middle push rod assembly comprising a middle push rod and a piston body arranged on the outer wall of the middle push rod, the middle push rod is slidably connected in the sleeve through the piston body, and the rear push rod assembly is slidably connected in the middle push rod, the front end of the sleeve is provided with an injection port and a matching seal, the front end of the middle push rod is provided with a drug outlet hole, a matching seal cover body is installed at the drug outlet hole, the front end of the middle push rod, the cover body and the sleeve form a front closed cavity, the front end of the rear push rod assembly, the cover body and the middle push rod form a rear closed cavity, characterized in that: The peripheral wall of the middle push rod has an elastic part that can be retracted and expanded. In the initial position, the elastic part is in an expanded state that blocks the rear end of the sleeve. In this state, the rear push rod assembly can move forward relative to the middle push rod and block the elastic part from retracting, so that the middle push rod cannot move forward relative to the sleeve. A groove is provided on the peripheral wall of the rear push rod assembly. When the rear push rod assembly moves forward until the groove cooperates with the elastic part on the middle push rod, the elastic part can be retracted and released from the sleeve, and the middle push rod can move forward relative to the sleeve.

2. The drug mixing syringe according to claim 1, characterized in that: The rear push rod assembly and the middle push rod have a matching connection structure. When the rear push rod assembly moves forward to the matching position between the groove and the elastic part on the middle push rod, the connection structure cooperates, and the rear push rod assembly and the middle push rod move forward together relative to the sleeve.

3. The drug mixing syringe according to claim 2, characterized in that: The connection structure is such that when the rear push rod assembly moves forward to a position where the groove cooperates with the elastic portion on the middle push rod, the rear push rod assembly is flush with the rear end of the middle push rod.

4. The drug mixing syringe according to claim 1, characterized in that: The rear end of the sleeve is provided with an outwardly expanded grasping portion, the grasping portion is provided with an outwardly expanded inner wall, and the elastic portion cooperates with the inner wall of the grasping portion to resist.

5. The drug mixing syringe according to any one of claims 1 to 4, characterized in that: The rear push rod assembly includes a hollow rear push rod and a piston arranged at the front end of the rear push rod. The rear end of the middle push rod is expanded outward and has an expanded inner circumferential wall. A matching positioning mechanism is provided between the inner circumferential wall and the rear push rod. The positioning mechanism cooperates to keep the rear push rod assembly at an initial position in sliding connection with the middle push rod.

6. The drug mixing syringe according to any one of claims 1 to 4, characterized in that: An exhaust groove is provided on the inner wall of the sleeve, and the exhaust groove is used for the front sealing cavity to communicate with the outside.

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