Dose adjusting mechanism of needleless injector and needleless injector

Abstract

The utility model relates to the technical field of needleless injectors, in particular to a needleless injector dose adjusting mechanism and a needleless injector. The needleless injector comprises a shell, an inner cylinder in threaded connection with the shell and a piston assembly which is arranged in linkage with the shell and sucks liquid medicine in the axial movement process of the shell. The dose adjusting mechanism comprises at least two elastic positioning buckles uniformly distributed in the circumferential direction of the shell and at least two positioning grooves distributed in the circumferential direction of the inner cylinder at intervals, and each positioning groove extends in the axial direction of the shell; each elastic positioning buckle comprises an elastic base body and a positioning part which protrudes from the elastic base body to the positioning groove and is matched with the positioning groove; according to the utility model, the elastic positioning buckles on the shell are matched with the positioning grooves to realize quantitative adjustment of dosage, at least two uniformly distributed elastic positioning buckles enable the shell to be stressed uniformly and rotate smoothly, the clamping stagnation of the shell can be avoided, in addition, the elastic positioning buckles are simple in structure and convenient to assemble, and the production cost is reduced while the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of needle-free injector technology, and in particular to a needle-free injector dosage adjustment mechanism and a needle-free injector. Background Technology

[0002] A needle-free injector generally consists of a threaded outer shell and an inner cylinder. The two rotate relative to each other and have axial displacement. The outer shell can drive the piston assembly to move back and forth through a linkage mechanism. The piston assembly can draw up the drug when it moves backward and push the drug out at high speed when it moves forward. The dosage can be quantitatively adjusted by installing a dosage adjustment mechanism between the outer shell and the inner cylinder.

[0003] Currently, metering and adjustment mechanisms generally include a positioning groove on the inner cylinder and a positioning buckle on the outer shell. When the outer shell is rotated to move the positioning buckle from the current positioning groove to the next positioning groove, a quantitative amount of medicine can be drawn to achieve dosage adjustment. However, in existing technologies, only one positioning buckle is usually set. When rotating the outer shell, the positioning buckle embedded in the current positioning groove needs to be disengaged. During the disengagement process, the positioning groove and the positioning buckle interact, causing uneven force on the outer shell, which leads to phenomena such as jamming during the rotation of the outer shell. In addition, the positioning buckle structure is relatively complex, resulting in high cost and time-consuming assembly. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to solve the problem that in the prior art, only one positioning buckle is set, and when rotating the shell, the positioning buckle embedded in the current positioning groove needs to be disengaged from it. During the disengagement process, the positioning groove and the positioning buckle interact, causing uneven force on the shell and resulting in jamming during the rotation of the shell. The present invention provides a needleless injector dosage adjustment mechanism and a needleless injector.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a needleless injector dosage adjustment mechanism, comprising a needleless injector including a shell, an inner cylinder threadedly connected to the shell, and a piston assembly that is linked to the shell and draws in liquid medicine during the axial movement of the shell. The dosage adjustment mechanism is used to quantitatively adjust the dosage of liquid medicine drawn in by the piston assembly. The dosage adjustment mechanism includes at least two elastic positioning buckles evenly distributed along the circumference of the shell and at least two positioning grooves spaced apart along the circumference of the inner cylinder. Each positioning groove extends along the axial direction of the shell, and each elastic positioning buckle includes an elastic base and a positioning part protruding from the elastic base toward the positioning groove to cooperate with the positioning groove.

[0006] Furthermore, one end of the elastic substrate is fixed to the outer shell as a fixed end, and the other end is a suspended end. The elastic substrate gradually tilts or bends towards the central axis of the inner cylinder from the fixed end to the suspended end, and the positioning part is located on the suspended end of the elastic substrate.

[0007] Furthermore, the outer casing has at least two receiving slots along its circumference for accommodating the elastic positioning buckle.

[0008] Furthermore, the positioning part is hemispherical, spherical, or cylindrical, and the cross-section of the positioning groove is an arc-shaped structure that fits the positioning part.

[0009] Furthermore, the thickness of the elastic matrix is ​​less than the wall thickness of the outer shell.

[0010] Furthermore, a visualization mechanism for displaying the dosage of the drug solution drawn by the piston assembly is provided between the outer shell and the inner cylinder.

[0011] Furthermore, the visualization mechanism includes a scale marked on the inner sleeve, a magnifying glass for magnifying the scale, and a fixed cover placed outside the magnifying glass to confine the magnifying glass within the outer sleeve.

[0012] Furthermore, the elastic positioning buckle is integrally formed with the outer shell.

[0013] A needle-free injector includes the aforementioned dosage adjustment mechanism.

[0014] The beneficial effects of this utility model are as follows: This utility model utilizes the elastic positioning buckle on the outer shell in conjunction with the positioning groove to achieve quantitative adjustment of the dosage. Moreover, at least two evenly distributed elastic positioning buckles ensure that the outer shell rotates smoothly under uniform force, which can prevent the outer shell from jamming. In addition, the elastic positioning buckle structure is simple and easy to assemble, which improves production efficiency and reduces production costs. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a 3D schematic diagram of a needle-free injector;

[0017] Figure 2 This is a cross-sectional view of the present invention;

[0018] Figure 3 This is a three-dimensional schematic diagram of the outer shell;

[0019] Figure 4 This is a three-dimensional schematic diagram of the inner cylinder;

[0020] 1. Outer shell;

[0021] 2. Inner cylinder;

[0022] 3. Piston assembly;

[0023] 4. Elastic positioning buckle; 401. Elastic base; 4011. Fixed end; 4012. Suspension end; 402. Positioning part;

[0024] 5. Positioning groove;

[0025] 6. Receiving tank;

[0026] 7. Magnifying glass;

[0027] 8. Fixing cover.

[0028] 9. Scale. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention. Therefore, they only show the components relevant to the present invention. Orientations and references (e.g., up, down, left, right, etc.) are only used to aid in the description of the features in the drawings. Therefore, the following specific embodiments are not intended to be restrictive, and the scope of the claimed subject matter is defined solely by the appended claims and their equivalents.

[0030] like Figure 1 and Figure 2 As shown, a needleless injector dosage adjustment mechanism is disclosed. The needleless injector includes a housing 1, an inner cylinder 2 threadedly connected to the housing 1, and a piston assembly 3 that is linked to the housing 1 and draws in liquid medication during the axial movement of the housing 1. The housing 1 includes an inner ring and an outer ring. The inner cylinder 2 is located in the annular cavity between the inner ring and the outer ring and is threadedly connected to the inner ring. The piston assembly 3 is located inside the inner cylinder 2. When the housing 1 moves the piston assembly 3 backward through the linkage mechanism, it can draw in liquid medication. When the piston assembly 3 moves forward, it can push out liquid medication.

[0031] The dosage adjustment mechanism is used to quantitatively adjust the dosage of the drug solution drawn by the piston assembly 3. The dosage adjustment mechanism includes at least two elastic positioning buckles 4 evenly distributed along the circumference of the outer shell 1 and at least two positioning grooves 5 distributed along the circumference of the inner cylinder 2. Each positioning groove 5 extends along the axial direction of the outer shell 1 and does not penetrate the two ends of the inner cylinder 2 along its axial direction. The number of elastic positioning buckles 4 can be, but is not limited to, two, three or four, etc. The number of elastic positioning buckles 4 corresponds to the number of positioning grooves 5 and is in a one-to-many relationship. The more positioning grooves 5 there are, the higher the adjustment accuracy of the dosage adjustment mechanism.

[0032] Each elastic positioning buckle 4 includes an elastic base 401 and a positioning part 402 protruding from the elastic base 401 toward the positioning groove 5 to cooperate with the positioning groove 5. The cross-sectional area of ​​the positioning part 402 is much smaller than the cross-sectional area of ​​the elastic base 401. The width of the elastic base 401 is greater than the groove width of the positioning groove 5 to limit it outside the positioning groove 5, so as to prevent it from entering the positioning groove 5 and obstructing the rotation of the outer shell 1. During the rotation of the outer shell 1, after the positioning part 402 enters the next positioning groove 5 from the current positioning groove 5, it can obtain a unit suction volume, thereby realizing quantitative suction. When the elastic positioning buckle 4 is disengaged from the current positioning groove 5 by force, the elastic base 401 undergoes elastic deformation (i.e., bending outward). When it reaches the adjacent positioning groove 5, the elastic base 401 resets and drives the positioning part 402 to be inserted into the positioning groove 5.

[0033] Rotating the outer shell 1 causes axial displacement between the outer shell 1 and the inner cylinder 2. This displacement drives the piston assembly 3 to move backward via a linkage mechanism to draw in the liquid medicine. Simultaneously, the positioning part 402 on the outer shell 1 rotates and moves backward, entering the next positioning slot 5 from the current positioning slot 5. During this process, the positioning slot 5 interacts with the elastic positioning buckle 4. Because there are multiple elastic positioning buckles 4 evenly distributed along the outer shell 1, the outer shell 1 is subjected to uniform force and rotates smoothly, preventing the outer shell 1 from getting stuck. In addition, the elastic positioning buckle 4 has a simple structure and is easy to assemble, which improves assembly efficiency and reduces production costs.

[0034] In some examples, one end of the elastic substrate 401 is fixed to the outer shell 1 as a fixed end 4011, and the other end is a suspended end 4012. The elastic substrate 401 gradually tilts or bends towards the central axis of the inner cylinder 2 from the fixed end 4011 to the suspended end 4012. The positioning part 402 is located on the suspended end 4012 of the elastic substrate 401. The elastic substrate 401 of this shape can provide an initial thrust to the positioning part 402, improve the engagement effect between the positioning part 402 and the positioning groove 5, thereby increasing the operator's feel and improving the dosage adjustment accuracy.

[0035] In some examples, the outer shell 1 has at least two receiving grooves 6 along its circumference for accommodating the elastic positioning buckles 4, and the width of the receiving grooves 6 is smaller than the width of the elastic base 401 to allow the elastic base 401 to undergo a certain deformation. At least two elastic positioning buckles 4 correspond one-to-one with at least two receiving grooves 6, and each elastic positioning buckle 4 is located in its corresponding receiving groove 6. The receiving grooves 6 can limit the elastic positioning buckles 4 in the circumferential direction to prevent the positioning part 402 from being stuck in the positioning groove 5 during the rotation of the outer shell 1. The fixed end 4011 of the elastic base 401 fixed to the outer shell 1 tends to rotate with the outer shell 1, while the suspended end 4012 fixed to the positioning part 402 does not move, which makes the elastic base 401 easy to break. The setting of the receiving grooves 6 can push the middle part of the elastic base 401 to rotate synchronously with the fixed end 4011 through its groove wall, thereby reducing the possibility of the elastic base 401 breaking.

[0036] In some examples, the positioning part 402 is hemispherical, spherical, or cylindrical, and the cross-section of the positioning groove 5 is an arc-shaped structure that fits the positioning part 402, making it easier for the positioning part 402 to enter and exit the positioning groove 5.

[0037] In some examples, the thickness of the elastic matrix 401 is less than the wall thickness of the outer shell 1. The elastic matrix 401 has a sheet-like structure. The thinner elastic matrix 401 is more likely to undergo elastic deformation, making it easier for the operator to work.

[0038] In some examples, the elastic positioning buckle 4 is integrally formed with the outer shell 1, thereby improving the connection strength between the two.

[0039] In some examples, a visualization mechanism is provided between the outer shell 1 and the inner cylinder 2 to display the dosage of the drug solution drawn by the piston assembly 3. During the dosage adjustment process, the operator can understand the current dosage at any time through the visualization mechanism, thereby further improving the adjustment accuracy.

[0040] In some examples, the visualization mechanism includes a scale 9 marked on the inner sleeve, a magnifying glass 7 for magnifying the scale 9, and a fixing cover 8 disposed outside the magnifying glass 7 to confine the magnifying glass 7 within the outer casing 1. The fixing cover 8 engages with the outer casing 1 and presses against the edge of the magnifying glass 7 to fix the magnifying glass 7 in place. The outer casing 1 has a mounting groove that extends radially through it for mounting the magnifying glass 7. The fixing cover 8 has a viewing window communicating with the mounting groove. The operator can observe the current dose by sequentially viewing the window and the magnifying glass 7.

[0041] Working principle:

[0042] Rotating the outer shell 1 causes axial displacement between the outer shell 1 and the inner cylinder 2. This displacement drives the piston assembly 3 to move backward via a linkage mechanism to draw in the liquid medicine. Simultaneously, when the positioning part 402 on the outer shell 1 is disengaged from the current positioning groove 5, the elastic base 401 undergoes elastic deformation. When it reaches the adjacent positioning groove 5, the elastic base 401 resets, causing the positioning part 402 to engage with the positioning groove 5. During this process, the positioning groove 5 interacts with the elastic positioning buckle 4. Because there are multiple elastic positioning buckles 4 evenly distributed along the outer shell 1, the outer shell 1 rotates smoothly under uniform force, preventing the outer shell 1 from getting stuck.

[0043] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A dose setting mechanism for a needleless injector, the needleless injector comprising a housing (1), an inner cylinder (2) threadedly connected to the housing (1), and a piston assembly (3) arranged in connection with the housing (1) and adapted to draw up a dose of a medicament during an axial movement of the housing (1), the dose setting mechanism being adapted to dose set the piston assembly (3) to draw up a dose of the medicament, characterized in that: The dose adjusting mechanism comprises at least two elastic positioning buckles (4) evenly distributed along the circumference of the outer shell (1) and at least two positioning grooves (5) spaced along the circumference of the inner cylinder (2), each of the positioning grooves (5) extending axially along the inner cylinder (2), each of the elastic positioning buckles (4) comprising an elastic base (401) and a positioning portion (402) protruding from the elastic base (401) towards the positioning groove (5) to cooperate with the positioning groove (5).

2. A needle-free injector dose setting mechanism according to claim 1, wherein: One end of the elastic base (401) is fixed to the outer shell (1) as a fixed end (4011) and the other end is a suspended end (4012), and the elastic base (401) gradually inclines or bends towards the central axis of the outer shell (1) from the fixed end (4011) to the suspended end (4012), and the positioning portion (402) is located on the suspended end (4012) of the elastic base (401).

3. A needle-free injector dose setting mechanism according to claim 1, wherein: The outer shell (1) is provided with at least two accommodating grooves (6) along the circumference thereof for accommodating the elastic positioning buckles (4).

4. A needle-free injector dose setting mechanism according to claim 1, wherein: The positioning portion (402) is semispherical, spherical crown-shaped or cylindrical, and the positioning groove (5) is arc-shaped in cross section to cooperate with the positioning portion (402).

5. A needle-free injector dose setting mechanism as defined in claim 1, wherein: The thickness of the elastic base (401) is less than the wall thickness of the cylinder wall of the outer shell (1).

6. A needle-free injector dose setting mechanism as defined in claim 1, wherein: The elastic positioning buckle (4) is integrally formed with the outer shell (1).

7. A needle-free injector dose setting mechanism as defined in claim 1, wherein: A visualization mechanism is arranged between the outer shell (1) and the inner cylinder (2) to display the dose of the suctioned medicine solution of the piston assembly (3).

8. A needle-free injector dose setting mechanism according to claim 7, wherein: The visualization mechanism comprises a scale (9) marked on the inner sleeve, a magnifying lens (7) for magnifying the scale (9) and a fixed cover (8) covering the outer side of the magnifying lens (7) to limit the magnifying lens (7) in the outer shell (1).

9. A needle-free injector characterized by: The dose adjusting mechanism comprises at least two elastic positioning buckles (4) evenly distributed along the circumference of the outer shell (1) and at least two positioning grooves (5) spaced along the circumference of the inner cylinder (2), each of the positioning grooves (5) extending axially along the inner cylinder (2), each of the elastic positioning buckles (4) comprising an elastic base (401) and a positioning portion (402) protruding from the elastic base (401) towards the positioning groove (5) to cooperate with the positioning groove (5).

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