An injection device

Abstract

The present invention discloses an injection device, which includes a first tube body, a second tube body and a third tube body coaxially sleeved; the inner walls of the first tube body, the second tube body and the third tube body are sequentially communicated to form a positioning cavity for embedding and axially positioning a prefilled syringe; a push rod is provided at the end of the positioning cavity and is slidably connected along the axis; the push rod is used to press and push the piston of the prefilled syringe to move; the first tube body is slidably connected to the first end of the second tube body for adjusting the length of the needle of the prefilled syringe protruding; the third tube body is slidably connected to the second end of the second tube body for adjusting the axial displacement of the push rod relative to the piston. The relative sliding of the first tube body and the second tube body can adjust the elongation of the needle of the prefilled syringe, and the relative sliding of the second tube body and the third tube body can adjust the moving range of the push rod relative to the prefilled syringe, so as to realize the adjustment of the injection depth and the injection volume; the injection device has a simple structure, few components, and greatly reduces the risk of failure.

Description

Technical Field

[0001] The present invention relates to the field of medical supplies, and in particular to an injection device. Background Art

[0002] Prefilled syringes refer to an advanced form of drug packaging, where the drug is pre-filled in a quantitative manner and can be directly taken out for injection in the clinic. Injection devices refer to a supporting medical device for prefilled syringes.

[0003] In order to prevent non-professional users, such as diabetics, from being unable to control the injection depth when injecting insulin through a prefilled syringe, injection devices currently on the market can already adjust the injection dose and injection depth. However, the disadvantages of the prior art still have the following problems.

[0004] 1. Complex structure and high failure rate. At present, some injection devices on the market have a total of 24 parts and components, and the structure is very complex. The risk of failure of any part during use will be borne by the patient.

[0005] Second, there are many parts and the manufacturing cost is high, which puts a heavy financial burden on patients.

[0006] 3. Incomplete functional coverage: Most of the injection devices provided by the prior art have a single function and can only adjust the injection depth or injection volume. Summary of the invention

[0007] The object of the present invention is to provide an injection device which can adjust the injection depth and injection volume with a simple and reliable structure.

[0008] To achieve the above-mentioned object, the present invention provides an injection device, comprising a first tube body, a second tube body and a third tube body which are coaxially sleeved; the inner walls of the first tube body, the second tube body and the third tube body are sequentially connected to form a positioning cavity for inserting and axially positioning a prefilled syringe; a push rod which is axially slidably connected is provided at the end of the positioning cavity; the push rod is used to press and push the piston of the prefilled syringe to move;

[0009] The first tube body is slidably connected to the first end of the second tube body to adjust the extension length of the needle of the prefilled syringe; the third tube body is slidably connected to the second end of the second tube body to adjust the axial displacement of the push rod relative to the piston.

[0010] Preferably, one of the first tube body and the second tube body is provided with a first sliding block, and the other is provided with a plurality of first positioning slots distributed along the axial direction for the first sliding block to slide to quantitatively adjust the extension length of the needle;

[0011] One of the third tube body and the second tube body is provided with a second sliding block, and the other is provided with a plurality of second positioning grooves distributed along the axial direction for the second sliding block to slide so as to quantitatively adjust the relative displacement of the push rod and the piston.

[0012] Preferably, the second tube body comprises a reservoir and a dosing device, both of which are tubular; a stop platform is provided in the reservoir for axially positioning the tail flange of the prefilled syringe; and the dosing device is used to press the tail flange toward the stop platform after the prefilled syringe is inserted into the reservoir.

[0013] Preferably, the contact surfaces of the reservoir and the dosing device are threadedly connected.

[0014] Preferably, the first sliding block is arranged on the inner wall of the storage container, and the first positioning slide grooves include a first main slideway arranged on the outer periphery of the first tube body and extending straight in the axial direction, and a plurality of first branch slideways connected to the first main slideway and extending straight in the radial direction;

[0015] The second sliding block is arranged on the inner wall of the third tube body, and all the second positioning slots are arranged on the outer periphery of the dosing device; the structure of all the second positioning slots is the same as the structure of all the first positioning slots.

[0016] Preferably, a transparent observation window is provided on the circumference of the first tube body.

[0017] Preferably, the radial dimension of the axial middle part of the push rod is larger than the radial dimension of the axial ends; a limiting hole is provided at the end of the positioning cavity; the radial dimension of the limiting hole is larger than the radial dimension of the two ends of the push rod and smaller than the radial dimension of the axial middle part of the push rod.

[0018] Preferably, a pressing handle is detachably connected to the end of the push rod.

[0019] Preferably, the first tube body, the second tube body, the third tube body and the push rod are all injection molded parts.

[0020] Preferably, a cap remover is coaxially sleeved at one end of the first tube away from the second tube; and a cap remover barb for hooking and pulling the protective cap of the prefilled syringe is provided on the inner wall of the cap remover.

[0021] Compared with the above background technology, the injection device provided by the present invention includes a push rod, a first tube body, a second tube body and a third tube body which are coaxially sleeved.

[0022] The inner walls of the first tube body, the second tube body and the third tube body are connected in sequence to form a positioning cavity for the prefilled syringe to be inserted and axially positioned, and the push rod is connected to the end of the positioning cavity by sliding along the axial direction of the positioning cavity. When the prefilled syringe is inserted and axially positioned in the positioning cavity, the push rod inserted into the positioning cavity presses against the outer surface of the piston of the prefilled syringe, and the user can push the piston of the prefilled syringe to move by pressing the push rod.

[0023] In the injection device, the first tube body is slidably connected to the first end of the second tube body, and the needle of the prefilled syringe can be exposed and retracted by stretching and compressing the sleeve length of the first tube body and the second tube body. In other words, the greater the total length of the first tube body and the second tube body, the more the needle of the prefilled syringe is blocked by the first tube body, and the depth to which the needle can be inserted into the human body is shallow; conversely, the needle can be inserted into the human body at a greater depth.

[0024] In the injection device, the third tube body is slidably connected to the second end of the second tube body. The axial displacement of the push rod relative to the piston can be adjusted by pulling the rope and compressing the sleeve length of the third tube body and the second tube body, thereby realizing the adjustment of the injection volume of the prefilled syringe.

[0025] The injection device provided by the present invention utilizes the first tube body, the second tube body and the third tube body to be assembled together to form a positioning cavity for inserting and axially positioning the prefilled syringe, and the push rod is combined to push the piston of the prefilled syringe to move, so as to realize the injection of the medicine in the prefilled syringe. The injection device can realize the quantitative adjustment of the injection depth and the injection dose, and the operation is simple and reliable, which is convenient for users to realize the quantitative and fixed depth injection of medicine by themselves.

[0026] In addition, the injection device provided by the present invention has a simple structure, a small number of parts, and no spring, thus avoiding the drawbacks of being unable to stop and over-rapid drug delivery caused by spring-controlled speed and automatic drug delivery, and greatly reducing the risk of failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 It is a structural schematic diagram of a prefilled syringe in the prior art;

[0029] Figure 2 A schematic structural diagram of an injection device provided by an embodiment of the present invention in a first assembly position;

[0030] Figure 3 A schematic structural diagram of an injection device provided by an embodiment of the present invention in a second assembly position;

[0031] Figure 4 A schematic diagram of the assembly of the injection device and the prefilled syringe provided by an embodiment of the present invention in a first state;

[0032] Figure 5 for Figure 4 A partial enlarged view of

[0033] Figure 6 A schematic diagram of the assembly of the injection device and the prefilled syringe provided by an embodiment of the present invention in a second state;

[0034] Figure 7 A schematic diagram of the assembly of the injection device and the prefilled syringe provided by an embodiment of the present invention in a third state;

[0035] Figure 8 A schematic diagram of the structure of a storage device provided by an embodiment of the present invention;

[0036] Fig. 9 for Figure 8 A cross-sectional view of

[0037] Fig.10 A schematic diagram of the structure of a quantitative device provided by an embodiment of the present invention;

[0038] Fig.11 for Fig.10 A cross-sectional view of

[0039] Fig.12 A schematic diagram of the structure of a cap remover provided in an embodiment of the present invention;

[0040] Fig.13 for Fig.12 A cross-sectional view of

[0041] Fig.14 A schematic diagram of the structure of a first tube body provided by an embodiment of the present invention;

[0042] Fig.15 for Fig.14 A cross-sectional view of

[0043] Fig.16 A schematic diagram of the structure of a second tube body provided by an embodiment of the present invention;

[0044] Fig.17 for Fig.16 A cross-sectional view of

[0045] Fig.18 A schematic diagram of the structure of a pressing handle provided by an embodiment of the present invention;

[0046] Fig.19 A schematic diagram of the structure of a push rod provided in an embodiment of the present invention.

[0047] Among them, 01-prefilled syringe, 011-piston, 012-tail flange, 013-protective cap, 014-needle, 1-cap remover, 11-cap remover barb, 2-first tube body, 21-first main slide, 22-first branch slide, 23-observation window, 3-reservoir, 31-stop platform, 32-first sliding block, 4-quantifier, 41-second main slide, 42-second branch slide, 43-push rod stop surface, 5-third tube body, 51-second sliding block, 52-limiting hole, 6-push rod, 7-pressing handle. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0050] Please refer to Figures 1 to 19 , Figure 1 It is a structural schematic diagram of a prefilled syringe in the prior art; Figure 2 A schematic structural diagram of an injection device provided by an embodiment of the present invention in a first assembly position; Figure 3 A schematic structural diagram of an injection device provided by an embodiment of the present invention in a second assembly position; Figure 4 A schematic diagram of the assembly of the injection device and the prefilled syringe provided by an embodiment of the present invention in a first state; Figure 5 for Figure 4 A partial enlarged view of Figure 6 A schematic diagram of the assembly of the injection device and the prefilled syringe provided by an embodiment of the present invention in a second state; Figure 7 A schematic diagram of the assembly of the injection device and the prefilled syringe provided by an embodiment of the present invention in a third state; Figure 8 A schematic diagram of the structure of a storage device provided by an embodiment of the present invention; Fig. 9 for Figure 8 A cross-sectional view of Fig.10 A schematic diagram of the structure of a quantitative device provided by an embodiment of the present invention; Fig.11 for Fig.10 A cross-sectional view of Fig.12A schematic diagram of the structure of a cap remover provided in an embodiment of the present invention; Fig.13 for Fig.12 A cross-sectional view of Fig.14 A schematic diagram of the structure of a first tube body provided by an embodiment of the present invention; Fig.15 for Fig.14 A cross-sectional view of Fig.16 A schematic diagram of the structure of a second tube body provided by an embodiment of the present invention; Fig.17 for Fig.16 A cross-sectional view of Fig.18 A schematic diagram of the structure of a pressing handle provided by an embodiment of the present invention; Fig.19 A schematic diagram of the structure of a push rod provided in an embodiment of the present invention.

[0051] The present invention provides an injection device, comprising a first tube body 2, a second tube body and a third tube body 5 which are coaxially sleeved.

[0052] In the injection device, the inner walls of the coaxially sleeved first tube body 2, the second tube body and the third tube body 5 are connected in sequence to form a positioning cavity, and the positioning cavity can be used for the prefilled syringe 01 to be inserted and axially positioned. The end of the positioning cavity is provided with a push rod 6 connected in an axial sliding manner, and the push rod 6 is used to press and push the piston 011 of the prefilled syringe 01 to move.

[0053] The prefilled syringe 01 is a disposable product filled with medicine, and the injection device provided by the present invention is equivalent to the shell of the prefilled syringe 01. Therefore, the specific shape and size of the positioning cavity formed by the first tube body 2, the second tube body and the third tube body 5 depend on the shape and size of the prefilled syringe 01.

[0054] When the injection device is used, the injection device is sleeved on the outer circumference of the prefilled syringe 01. Since the prefilled syringe 01 is positioned in the positioning cavity of the injection device, when the push rod 6 of the injection device is pushed, the push rod 6 pushes the piston 011 of the prefilled syringe 01 to move, so that the prefilled syringe 01 outputs the medicine from the needle 014 thereof.

[0055] A radially inwardly protruding positioning boss or flange or other structure can be provided in the positioning cavity of the injection device to realize axial positioning of the prefilled syringe 01 in the positioning cavity, thereby preventing the prefilled syringe 01 from moving synchronously with the push rod 6 when the push rod 6 pushes the piston 011 of the prefilled syringe 01.

[0056] The first tube body 2 of the injection device is slidably connected to the first end of the second tube body, and the extension length of the needle 014 of the prefilled syringe 01 can be adjusted by relative sliding of the first tube body 2 and the second tube body. For example, the prefilled syringe 01 and the second tube body remain relatively still, and the needle 014 of the prefilled syringe 01 extends toward the end connected to the first tube body 2. When the first tube body 2 is pulled along the second tube body to slide outward, the total axial length of the first tube body 2 and the second tube body increases, and the first tube body 2 covers most of the needle 014 of the prefilled syringe 01 inside, which means that at this time, the needle 014 of the prefilled syringe 01 is retracted inward, and the user can only make the needle 014 of the prefilled syringe 01 pierce the human body at a shallow depth. On the contrary, when the first tube body 2 is pushed to slide inward along the second tube body, the total axial length of the first tube body 2 and the second tube body is shortened, and the first tube body 2 exposes most of the needle 014 of the prefilled syringe 01 to the outside world, which means that at this time, the needle 014 of the prefilled syringe 01 extends outward, and the user can make the needle 014 of the prefilled syringe 01 penetrate the human body at a greater depth.

[0057] Similarly, the third tube body 5 is slidably connected to the second end of the second tube body, and the axial displacement of the push rod 6 relative to the piston 011 can be adjusted by the relative sliding of the third tube body 5 and the second tube body. Since the prefilled syringe 01 is stationary relative to the second tube body, when the third tube body 5 is pulled outward along the second tube body, the distance between the tail of the third tube body 5 and the prefilled syringe 01 increases, and the pushing range of the push rod 6 is constrained by the tail of the third tube body 5, that is, the longer the distance the third tube body 5 is pulled out of the second tube body, the shorter the distance the push rod 6 is pushed into the prefilled syringe 01, which means that the user uses the push rod 6 to inject less medicine into the human body. Conversely, the greater the distance the third tube body 5 is pushed into the second tube body, the longer the distance the push rod 6 is pushed into the prefilled syringe 01, which means that the user uses the push rod 6 to inject more medicine into the human body.

[0058] It can be seen that the injection device provided by the present invention utilizes the first tube body 2, the second tube body and the third tube body 5 to be assembled together into a positioning cavity for the prefilled syringe 01 to be inserted and axially positioned, and is combined with the push rod 6 to push the piston 011 of the prefilled syringe 01 to move, thereby realizing the injection of the medicine in the prefilled syringe 01. At the same time, the relative sliding of the first tube body 2 and the second tube body can realize the extension amount of the needle 014 of the prefilled syringe 01, which is convenient for the user to adjust the depth of the needle 014 of the prefilled syringe 01 inserted into the human body; the relative sliding of the second tube body and the third tube body 5 can realize the movement range of the push rod 6 relative to the piston 011 of the prefilled syringe 01, which is convenient for the user to adjust the amount of medicine injected into the human body by the prefilled syringe 01. The injection device is easy to operate and has comprehensive functions, which is conducive to the user to realize quantitative and fixed depth injection of medicine by themselves.

[0059] In summary, the injection device provided by the present invention has a simple structure, a small number of parts, and no spring, thus avoiding the drawbacks of being unable to stop and over-rapid drug delivery caused by spring-controlled speed and automatic drug delivery, and the risk of failure is greatly reduced; it can achieve quantitative adjustment of injection depth and injection dose, and is simple and reliable to operate.

[0060] The injection device provided by the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0061] On the basis of the above embodiments, in order to achieve better technical effects, in the injection device provided by the present invention, one of the first tube body 2 and the second tube body is provided with a first sliding block 32, and the other is provided with a plurality of first positioning grooves distributed along the axial direction. The first positioning groove is used to limit the sliding position of the first sliding block 32, thereby achieving quantitative adjustment of the extension length of the needle 014 of the prefilled syringe 01.

[0062] The first positioning slots are divided into multiple levels and are distributed along the axial direction of the first tube body 2 and the second tube body. Therefore, when the first sliding block 32 slides from one level of the first positioning slot to another level of the first positioning slot, the needle 014 of the prefilled syringe 01 extends outward or retracts inward by the length of the axial spacing between the two first positioning slots. It can be seen that when the user uses the injection device to inject medicine, the position of the first sliding block 32 in the multiple levels of the first positioning slots can be adjusted according to the required injection depth, thereby quantitatively adjusting the relative position relationship between the first tube body 2 and the second tube body.

[0063] As for the multi-level first positioning grooves, they can be arranged at equal intervals, so that the user can calculate the extended length of the needle 014 of the prefilled syringe 01 according to the sliding level of the first sliding block 32 between the first positioning grooves; they can also be distributed at non-equal intervals. Accordingly, any level of the first positioning groove is provided with a scale for the user to identify the extended length of the needle 014 of the prefilled syringe 01 corresponding to the current first positioning groove.

[0064] In this embodiment, one of the third tube body 5 and the second tube body is provided with a second sliding block 51, and the other is provided with a second positioning slot distributed in multiple stages along the axial direction for the second sliding block 51 to slide to quantitatively adjust the relative displacement of the push rod 6 and the piston 011. For the structure of the second sliding block 51 and the multiple second positioning slots, reference may be made to the arrangement of the first sliding block 32 and the multiple second positioning slots, which will not be described in detail here.

[0065] For easy operation, in the injection device provided by the present invention, the second tube body includes a tubular reservoir 3 and a dosing device 4 which are sleeved together. Since the reservoir 3 and the dosing device 4 are sleeved together, the reservoir 3 and the dosing device 4 are slidably connected to the first tube body 2 and the third tube body 5, respectively.

[0066] When the prefilled syringe 01 is installed by using the injection device, the prefilled syringe 01 can be axially positioned between the storage container 3 and the end contact surface of the positioner. For example, a stopper 31 is provided in the storage container 3 for axial positioning of the tail flange 012 of the prefilled syringe 01; the dosing device 4 is used to press the tail flange 012 toward the stopper 31 after the prefilled syringe 01 is inserted into the storage container 3. In simple terms, when the prefilled syringe 01 is inserted into the storage container 3, the tail flange 012 of the prefilled syringe 01 stops moving at the stopper 31 of the storage container 3, and then the dosing device 4 is inserted into the storage container 3, so that the end of the positioner presses the tail flange 012 of the prefilled syringe 01 against the stopper 31, and finally the tail flange 012 of the prefilled syringe 01 is clamped between the stopper 31 and the end of the positioner.

[0067] In order to ensure the structural connection strength of the second tube body, the storage container 3 and the dosing device 4 of the second tube body are fixedly connected by threads. Figure 8 to Figure 11 The inner wall of one end of the storage container 3 is provided with an internal thread, and the outer wall of one end of the positioner is provided with an external thread. When the storage container 3 and the positioner are separated from each other, the prefilled syringe 01 is inserted into the storage container 3, and then the doser 4 is inserted and fixedly connected to the storage container 3 through threads.

[0068] On the basis of the above-mentioned embodiment, in the injection device provided by the present invention, the first sliding block 32 is arranged on the inner wall of the storage container 3, and all the first positioning chutes include a first main chute 21 arranged on the outer periphery of the first tube body 2 and extending straight in the axial direction, and a plurality of first branch chute 22 connected to the first main chute 21 and extending straight in the radial direction. Similarly, the second sliding block 51 is arranged on the inner wall of the third tube body 5, and all the second positioning chute are arranged on the outer periphery of the metering device 4; the structure of all the second positioning chute is the same as that of all the first positioning chute.

[0069] In the above example, the first sliding block 32 is arranged on the storage container 3 , and the multi-stage first positioning grooves are arranged on the first tube body 2 ; the second sliding block 51 is arranged on the third tube body 5 , and the multi-stage second positioning grooves are arranged on the dosing device 4 .

[0070] The following is a detailed description using the first sliding block 32 and the multi-stage first positioning chute as an example. In the multi-stage first positioning chute, the first main slide 21 connects the multiple first branch slides 22, and the first sliding block 32 can move axially along the first main slide, and then slide into each first branch slide 22 to achieve axial positioning of the first sliding block 32. Obviously, the groove size of the first main slide is not less than the size of the first sliding block 32, and the groove size of each first branch slide 22 should match the size of the first sliding block 32 to ensure that the first sliding block 32 sliding into the first branch slide 22 is locked and positioned to avoid the two from affecting the position of the needle 014 of the prefilled syringe 01 relative to the injection device due to mutual deflection movement. Correspondingly, the multi-stage second positioning chute may include a second main slide 41 and multiple second branch slides 42.

[0071] In addition, a transparent observation window 23 is provided on the circumference of the first tube body 2. The user can identify the position of the prefilled syringe 01 relative to the first tube body 2 when the first tube body 2 and the reservoir 3 are stretched and pushed through the observation window 23, which is helpful for the user to accurately adjust the extension length of the needle 014 of the prefilled syringe 01.

[0072] For the push rod 6 used in the present invention, the radial dimension of the axial middle part is larger than the radial dimension of the axial ends. In other words, the push rod 6 is thick in the middle part and thin at the two ends. Accordingly, a limiting hole 52 is provided at the end of the positioning cavity, and the radial dimension of the limiting hole 52 is larger than the radial dimension of the two ends of the push rod 6 and smaller than the radial dimension of the axial middle part of the push rod 6. This means that the two ends of the push rod 6 can extend in or out along the aforementioned limiting hole 52, while the middle part of the push rod 6 cannot pass through the limiting hole 52. Therefore, the injection device with the above-mentioned push rod 6 and positioning cavity can restrict the sliding range of the push rod 6 in the positioning cavity, and prevent the push rod 6 from leaving the positioning cavity due to accidental action when the user holds the injection device.

[0073] In addition, the inner wall of the second tube body may be provided with a push rod stop surface 43 for restricting the distance that the push rod 6 slides toward the first tube body 2, so as to limit the maximum injection volume of the injection device for the prefilled syringe 01. For the second tube body having the reservoir 3 and the doser 4, the push rod stop surface 43 may be provided on the inner wall of the doser 4.

[0074] Furthermore, the end of the push rod 6 is detachably connected with a pressing handle 7. The pressing handle 7 is used for the user's thumb to press, so that the user can apply a thrust to the push rod 6 to push the piston 011 of the prefilled syringe 01 to move. According to the aforementioned embodiment, the middle part of the push rod 6 cannot pass through the limiting hole 52 of the positioning cavity. Therefore, in this embodiment, the push rod 6 and the pressing handle 7 are detachably connected. When the push rod 6 is installed in the positioning cavity, the push rod 6 and the pressing handle 7 are separated from each other, so the push rod 6 can be inserted inward from the head of the third tube body 5, and pass through the limiting hole 52 at the tail of the third tube body 5 and then fixedly connected to the pressing handle 7.

[0075] The surface of the pressing handle 7 may be provided with an anti-skid texture to prevent the user from slipping when pressing the push rod 6 .

[0076] In order to improve the safety and sanitation of the injection operation, in the injection device provided by the present invention, the first tube body 2, the second tube body, the third tube body 5 and the push rod 6 are all injection molded parts, for example, using medical grade resin materials commonly used in the medical industry. In this way, the injection device has a single material, low cost, is disposable after use, does not require complex classification, and is scientific and hygienic. In particular, the injection device using medical grade resin materials can greatly simplify recycling and disposal.

[0077] The injection device provided by the present invention is also provided with a cap remover 1, which is coaxially sleeved on one end of the first tube body 2 away from the second tube body. In this embodiment, the inner wall of the cap remover 1 is provided with a cap removal barb 11 for hooking and pulling the protective cap 013 of the prefilled syringe 01, so that when the prefilled syringe 01 is axially inserted and positioned in the positioning cavity of the injection device, the protective cap 013 of the prefilled syringe 01 is fixedly connected to the cap remover 1 through the cap removal barb 11, and the user can remove the protective cap 013 of the prefilled syringe 01 by pulling the cap remover 1. In other words, when the prefilled syringe 01 is assembled in the positioning cavity of the injection device, the protective cap 013 of the prefilled syringe 01 is always retained on the periphery of its needle 014, which can ensure the safety of the user.

[0078] For the second tube body formed by the storage container 3 and the metering device 4, the cap remover 1 can combine with the storage container 3 and the metering device 4 to accurately and quickly separate the main body of the prefilled syringe 01 and its protective cap 013. The specific operation is as follows:

[0079] On the basis that the decapper 1 and the first tube body 2 are connected to the storage container 3, the prefilled syringe 01 is inserted into the storage container 3, and the dosing device 4 is inserted into the storage container 3, and the tail flange 012 of the prefilled syringe 01 is squeezed against the stop table 31 of the storage container 3 by rotating the dosing device 4. In this process, once a "click" sound is heard, it means that the protective cap 013 of the prefilled syringe 01 is squeezed into the middle decapping barb 11 of the decapper 1, and the aforementioned protective cap 013 and the decapper 1 are relatively fixed. Then, the protective cap 013 of the prefilled syringe 01 is removed by rotating the decapper 1 and retained in the decapper 1. Subsequently, the extension length of the needle 014 of the prefilled syringe 01 and the single injection volume can be adjusted by rotating and pulling the first tube body 2 and the storage container 3, the third tube body 5 and the dosing device 4, respectively, to achieve multi-point quantitative fixed depth injection.

[0080] The injection device provided by the present invention has a simple structure, is economical and practical, safe and effective, has a low failure rate, and is comprehensive in functions. The slide rail structure between the first tube body 2 and the reservoir 3, and between the third tube body 5 and the dosing device 4 realizes the adjustment of the extension length and injection volume of the needle 014 of the prefilled syringe 01 by rotation and pulling, providing a safe, effective and convenient clinical operation solution for the application of the prefilled syringe 01 in the fields of beauty, vaccines, insulin injection, etc.

[0081] The above is a detailed introduction to the injection device provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, the present invention can also be improved and modified without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An injection device, characterized in that, it includes a first tube body (2), a second tube body, and a third tube body (5) that are coaxially sleeved; the inner walls of the first tube body (2), the second tube body, and the third tube body (5) are sequentially connected and form a positioning cavity for embedding and axially positioning a pre-filled syringe (01); a push rod (6) is provided at the end of the positioning cavity and is slidably connected along the axis; the push rod (6) is used to press and push the piston (011) of the pre-filled syringe (01) to move; the first tube body (2) is slidably connected to the first end of the second tube body to adjust the length of the needle tip of the pre-filled syringe (01) protruding; the third tube body (5) is slidably connected to the second end of the second tube body to adjust the axial displacement of the push rod (6) relative to the piston (011); the second tube body includes a storage container (3) and a metering device (4) both in tubular shape, the storage container (3) and the metering device (4) are respectively slidably connected to the first tube body (2) and the third tube body (5); a stop platform (31) for axially positioning the tail flange (012) of the pre-filled syringe (01) is provided in the storage container (3); the metering device (4) is used to press the tail flange (012) against the stop platform (31) after the pre-filled syringe (01) is inserted into the storage container (3); the contact surfaces of the storage container (3) and the metering device (4) are threadedly connected; the radial dimension of the middle part of the push rod (6) in the axial direction is larger than the radial dimensions of both ends in the axial direction; a limiting hole (52) is provided at the end of the positioning cavity; the radial dimension of the limiting hole (52) is larger than the radial dimensions of both ends of the push rod (6) and smaller than the radial dimension of the middle part of the push rod (6) in the axial direction.

2. The injection device according to claim 1, characterized in that, in the first tube body (2) and the second tube body, one is provided with a first sliding block (32), and the other is provided with a first positioning chute that is distributed in multiple levels along the axis and is used for the first sliding block (32) to slide to achieve quantitative adjustment of the needle tip protruding length; in the third tube body (5) and the second tube body, one is provided with a second sliding block (51), and the other is provided with a second positioning chute that is distributed in multiple levels along the axis and is used for the second sliding block (51) to slide to achieve quantitative adjustment of the relative displacement between the push rod (6) and the piston (011); 3. The injection device according to claim 2, characterized in that, the first sliding block (32) is arranged on the inner wall of the storage container (3), and all the first positioning chutes include a first main chute (21) arranged on the outer periphery of the first tube body (2) and extending straight along the axis and multiple first branch chutes (22) that communicate with the first main chute (21) and extend straight in the radial direction; the second sliding block (51) is arranged on the inner wall of the third tube body (5), and all the second positioning chutes are arranged on the outer periphery of the metering device (4); the structures of all the second positioning chutes are the same as the structures of all the first positioning chutes.

4. The injection device according to claim 1, characterized in that, A transparent observation window (23) is provided on the circumferential side of the first tube body (2).

5. The injection device according to claim 1, characterized in that a pressing handle (7) is detachably connected to the end of the push rod (6).

6. The injection device according to claim 1, characterized in that the first tube body (2), the second tube body, the third tube body (5) and the push rod (6) are all injection molded parts.

7. The injection device according to any one of claims 1 to 6, characterized in that a cap remover (1) is coaxially sleeved on one end of the first tube body (2) away from the second tube body; a cap removal barb (11) for hooking the protective cap (013) of the pre-filled syringe (01) is provided on the inner wall of the cap remover (1).

Images