One-way transmission mechanism for needle-free syringes

Abstract

The present invention provides a one-way transmission mechanism for a needle-free syringe, which includes a main striker, a main locking spring and a retaining sleeve; the main locking spring is elastically connected between the plug and the retaining sleeve; the retaining sleeve is outer-mounted on the main striker and has a matching ear at the front end of the retaining sleeve, the front end of the piston has a matching groove for the matching ear to extend, and the rear end surface of the matching ear is crimped with the bottom of the matching groove; a plurality of oblong holes are opened on the outer circumference of the retaining sleeve, a steel ball is arranged in the oblong hole, the inner wall of the piston at the position corresponding to the oblong hole is a conical sleeve with a front end radius greater than a rear end radius relative to the outer circumferential surface of the main striker, the steel ball is in line contact with the main striker and the inner wall of the piston, and a spring wire is elastically connected between the front end of the steel ball and the retaining sleeve. The present invention has a reasonable structural design, and through the cooperation of the steel ball, the main striker and the retaining sleeve, the main striker and the piston are locked during the forward movement, effectively ensuring the stability and effectiveness of the one-way transmission, and facilitating the pressurized impact of the front end syringe push rod.

Description

Technical Field

[0001] The invention relates to the field of medical equipment, in particular to the technical field of needle-free injectors, and in particular to a one-way transmission mechanism for needle-free injectors. Background Art

[0002] The pressure generated by the pressure device inside the needle-free syringe pushes the liquid medicine in the medicine tube through the micropores to form an extremely fine liquid medicine column, which allows the liquid medicine to instantly penetrate the human epidermis and reach the subcutaneous tissue, where it is diffusely absorbed. During the injection process of the needle-free syringe, the main striker pushes the front syringe push rod to pressurize the liquid medicine. In the design process of the needle-free syringe, how to design the one-way transmission between the piston and the main striker to ensure that the main striker can be stably driven forward to impact during the forward movement of the piston has become an urgent problem to be solved. Summary of the invention

[0003] The technical problem to be solved by the present invention is: in order to overcome the deficiencies of the prior art, the present invention provides a one-way transmission mechanism for a needle-free syringe which has a reasonable structural design and can effectively drive the main striker to move forward through line contact during the forward movement of the piston.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a one-way transmission mechanism for a needle-free syringe, which is installed in the needle-free syringe, the needle-free syringe includes a sleeve, a syringe push rod is arranged in the front end of the sleeve, an impact rod is arranged at the rear end of the syringe push rod, a power element is arranged in the rear end of the sleeve, the power element includes a piston that moves back and forth in the sleeve, and a plug is fixed at the front end of the piston. The one-way transmission mechanism for the needle-free syringe includes a main impact rod, a main locking spring and a retaining sleeve; the main impact rod contacts with the rear end of the impact rod during the forward movement and drives the impact rod to move forward, the main locking spring is elastically connected between the plug and the retaining sleeve and is arranged around the main impact rod; the retaining sleeve is outer-covered on the main impact rod and the front end plane of the retaining sleeve extends outward and has a circumferentially outwardly protruding mating ear, the piston The outer sleeve is outside the retaining sleeve and the main impact rod, and the front end of the piston has a matching groove for the matching ear to extend out, and the rear end face of the matching ear is crimped with the bottom of the matching groove; a plurality of oblong holes are opened on the outer circumference of the retaining sleeve, and a steel ball is arranged in each oblong hole, and the surface of the main impact rod is respectively provided with lower embedded grooves corresponding to the positions of the oblong holes, and the radial cross-section of the lower embedded groove is an arc-shaped surface adapted to the outer cylindrical surface of the steel ball, and the inner wall of the piston at the position corresponding to the oblong hole is a conical sleeve with a front end radius greater than the rear end radius relative to the outer circumferential surface of the main impact rod, and the rear end face of the conical sleeve contacts and abuts against the rear end of the steel ball, and the inner wall of the conical sleeve corresponding to the steel ball also has an upper embedded groove matching the contact surface of the steel ball, and the upper embedded groove is also an arc-shaped surface, and the steel ball is in line contact with the main impact rod and the inner wall of the piston, and a spring wire is elastically connected between the front end of the steel ball and the retaining sleeve.

[0005] In the above scheme, the retaining sleeve, steel ball, main striker and piston are cleverly designed. When the piston moves forward, the mating groove pushes the mating ear to drive the retaining sleeve forward synchronously. The steel ball locks the piston and the main striker through the conical sleeve, and synchronously drives the main striker to move forward, effectively meeting the forward transmission requirements of the piston and the main striker, and the mating locking is stable.

[0006] Furthermore, the rear end of the spring wire is in an arc-shaped structure, the outer convex surface of the arc-shaped structure elastically resists the steel ball, the retaining sleeve has a through hole at the position corresponding to the front end of each steel ball, and the front end of the spring wire extends out through the through hole and hooks on the outer wall of the front end of the through hole.

[0007] Preferably, the front end of the spring wire includes a straight wire connected to one end of the arc-shaped structure and an L-shaped wire connected to the other end of the arc-shaped structure, the straight wire is inserted into the through hole, and one end of the L-shaped wire is hooked on the outer wall of the front end of the through hole.

[0008] The beneficial effect of the present invention is that the one-way transmission mechanism for the needle-free syringe provided by the present invention has a reasonable structural design. Through the cooperation of the steel ball, the main striker rod and the retaining sleeve, the main striker rod and the piston are locked during the forward movement, effectively ensuring the stability and effectiveness of the one-way transmission, and facilitating the pressurized impact of the front-end syringe push rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0010] Figure 1 It is a structural schematic diagram of the best embodiment of the present invention.

[0011] Figure 2 It is a stereoscopic diagram of the best embodiment of the present invention after removing the piston.

[0012] Figure 3 It is a three-dimensional diagram of the piston in the best embodiment of the present invention.

[0013] Figure 4 It is a schematic diagram of the structure of the spring wire in the optimal embodiment of the present invention.

[0014] In the figure, 1, sleeve 2, main striker 3, main locking spring 4, retaining sleeve 5, matching ear 6, matching groove 7, oblong hole 8, steel ball 9, lower embedding groove 10, tapered sleeve 11, arc surface 12, spring wire 13, straight wire 14, L-shaped wire 15, through hole 16, piston. DETAILED DESCRIPTION

[0015] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0016] like Figures 1 to 3 The one-way transmission mechanism for a needle-free syringe shown in the figure is the best embodiment of the present invention. The needle-free syringe comprises a sleeve 1, a syringe push rod is arranged in the front end of the sleeve 1, an impact rod is arranged in the rear end of the syringe push rod, a power element is arranged in the rear end of the sleeve 1, and the power element comprises a piston 16 that moves back and forth in the sleeve 1, and a plug is fixed at the front end of the piston 16.

[0017] The one-way transmission mechanism for the needle-free syringe includes a main striker 2, a main locking spring 3 and a retaining sleeve 4. The main striker 2 contacts the rear end of the impact rod during the forward movement and drives the impact rod to move forward, and the main locking spring 3 is elastically connected between the plug and the retaining sleeve 4 and is arranged around the main striker 2. The plug effectively elastically presses the main locking spring 3 and the retaining sleeve 4 into the piston 16.

[0018] The retaining sleeve 4 is sleeved on the main striker 2, and the front end plane of the retaining sleeve 4 extends outwardly and has a circumferentially outwardly protruding mating ear 5, the piston 16 is sleeved outside the retaining sleeve 4 and the main striker 2, and the front end of the piston 16 has a mating groove 6 for the mating ear 5 to extend out, and the rear end surface of the mating ear 5 is pressed against the bottom of the mating groove 6. When the piston 16 moves forward, the bottom of the groove is pressed against the rear end surface of the mating ear 5, and the retaining sleeve 4 is synchronously driven to move forward.

[0019] There are 8 oblong holes 7 on the outer circumference of the retaining sleeve 4, and a steel ball 8 is arranged in each oblong hole 7. The surface of the main impact rod 2 is respectively provided with lower embedded grooves 9 corresponding to the positions of the oblong holes 7. The radial cross-section of the lower embedded groove 9 is an arc-shaped surface adapted to the outer cylindrical surface of the steel ball 8. The inner wall of the piston 16 at the position corresponding to the oblong hole 7 is a conical sleeve 10 with a front end radius greater than the rear end radius relative to the outer circumferential surface of the main impact rod 2. The rear end surface of the conical sleeve 10 contacts and abuts against the rear end of the steel ball 8, and the inner wall of the conical sleeve 10 corresponding to the steel ball 8 also has an upper embedded groove 11 that matches the contact surface of the steel ball 8. The upper embedded groove 11 is also an arc-shaped surface. The steel ball 8 is in line contact with the main impact rod 2 and the inner wall of the piston 16, and a spring wire 12 is elastically connected between the front end of the steel ball 8 and the retaining sleeve 4.

[0020] In actual design, in order to facilitate the installation of the spring wire 12, the rear end of the spring wire 12 is an arc-shaped structure, the outer convex surface of the arc-shaped structure elastically abuts against the steel ball 8, and the retaining sleeve 4 is provided with a through hole 15 at the position corresponding to the front end of each steel ball 8, and the front end of the spring wire 12 extends through the through hole 15 and hooks on the outer wall of the front end of the through hole 15. The front end of the spring wire 12 includes a straight wire 13 connected to one end of the arc-shaped structure and an L-shaped wire 14 connected to the other end of the arc-shaped structure, the straight wire 13 penetrates and is inserted into the through hole 15, and one end of the L-shaped wire 14 is hooked on the outer wall of the front end of the through hole 15.

[0021] One-way locking principle:

[0022] With the cooperation of the matching groove 6 and the matching ear 5, when the piston 16 moves forward, it can drive the retaining sleeve 4 to move forward synchronously, and the steel ball 8 is located in the oblong hole 7. When the retaining sleeve 4 moves forward, under the synchronous action of the elastic force of the spring wire 12, the steel ball 8 is pressed into the lower embedding groove 9 of the main striker 2 and the upper embedding groove of the piston 16. The inner wall of the piston 16 corresponding to the position of the steel ball 8 is a conical sleeve 10. The steel ball 8 is in line contact with the main striker 2 and the piston 16. When the piston 16 moves forward, the steel ball 8 can lock the main striker 2 and the piston 16, that is, the piston 16 moves forward, and the main striker 2 moves forward synchronously.

[0023] The one-way transmission mechanism for needle-free syringes designed in this way has a reasonable structural design. Through the cooperation of the steel ball 8, the main striker 2, and the retaining sleeve 4, when the piston 16 moves forward, the matching groove 6 pushes the matching ear 5 to drive the retaining sleeve 4 forward synchronously, and the steel ball 8 locks the piston 16 and the main striker 2 through the tapered sleeve 10, and synchronously drives the main striker 2 to move forward, effectively meeting the forward transmission requirements of the piston 16 and the main striker 2. The main striker 2 and the piston 16 are locked during the forward movement, which effectively ensures the stability and effectiveness of the one-way transmission, and is convenient for pressurizing and impacting the front-end syringe push rod.

[0024] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A one-way transmission mechanism for a needle-free syringe, installed in the needle-free syringe, the needle-free syringe comprising a sleeve (1), a syringe push rod is arranged in the front end of the sleeve (1), an impact rod is arranged in the rear end of the syringe push rod, a power element is arranged in the rear end of the sleeve (1), the power element comprises a piston (16) moving back and forth in the sleeve (1), a plug is fixed at the front end of the piston (16), and the characteristics are: The one-way transmission mechanism for a needle-free syringe comprises a main striker (2), a main locking spring (3) and a retaining sleeve (4); The main striker (2) contacts the rear end of the impact rod during forward movement and drives the impact rod to move forward. The main locking spring (3) is elastically connected between the plug and the retaining sleeve (4) and is arranged around the main striker (2). The retaining sleeve (4) is sleeved on the main striker (2), and the front end plane of the retaining sleeve (4) extends outward and has a circumferentially outwardly protruding mating ear (5); the piston (16) is sleeved outside the retaining sleeve (4) and the main striker (2), and the front end of the piston (16) has a mating groove (6) for the mating ear (5) to extend out, and the rear end surface of the mating ear (5) is pressed against the bottom of the mating groove (6); The outer circumference of the retaining sleeve (4) is provided with a plurality of oblong holes (7), each of which is provided with a steel ball (8). The surface of the main striker (2) is provided with lower embedded grooves (9) at positions corresponding to the oblong holes (7). The radial cross section of the lower embedded groove (9) is an arc-shaped surface adapted to the outer circumferential surface of the steel ball (8). The inner wall of the piston (16) at the position corresponding to the oblong hole (7) is formed with a front end radius greater than a rear end radius relative to the outer circumferential surface of the main striker (2). The conical sleeve (10) has a radius of 1.5 mm, the rear end surface of the conical sleeve (10) contacts and abuts against the rear end of the steel ball (8), and the inner wall of the conical sleeve (10) corresponding to the steel ball (8) also has an upper embedding groove (11) that matches the contact surface of the steel ball (8), and the upper embedding groove (11) is also an arc surface. The steel ball (8) is in line contact with the main striker (2) and the inner wall of the piston (16), and a spring wire (12) is elastically connected between the front end of the steel ball (8) and the retaining sleeve (4).

2. The one-way transmission mechanism for a needle-free injector according to claim 1, characterized in that: The rear end of the spring wire (12) is in an arc-shaped structure, and the outer convex surface of the arc-shaped structure elastically contacts the steel ball (8). The retaining sleeve (4) is provided with a through hole (15) at a position corresponding to the front end of each steel ball (8), and the front end of the spring wire (12) extends out through the through hole (15) and is hooked on the outer wall of the front end of the through hole (15).

3. The one-way transmission mechanism for a needle-free injector according to claim 2, characterized in that: The front end of the spring wire (12) comprises a straight wire (13) connected to one end of the arc-shaped structure and an L-shaped wire (14) connected to the other end of the arc-shaped structure. The straight wire (13) is inserted into the through hole (15), and one end of the L-shaped wire (14) is hooked on the outer wall of the front end of the through hole (15).

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