Low-friction injector medicine pushing mechanism

Abstract

The utility model discloses a low-friction injector medicine pushing mechanism which comprises a driving nut, a push rod, a guide sleeve and an annular support, the driving nut is rotationally arranged in the annular support, threads are arranged on the outer circumferential face of the push rod, the push rod is in threaded connection with the driving nut, and the guide sleeve is fixedly arranged in the annular support. The push rod is slidably connected with a center hole of the guide sleeve, the diameter of the push rod is smaller than that of the center hole of the guide sleeve, the guide sleeve and the driving nut are coaxially arranged, and the driving nut is in power connection with the power assembly. According to the low-friction injector medicine pushing mechanism, the driving nut rotates to drive the screw to move along the axis, the piston core rod of the injector is pushed for injection, the push rod only moves in the axial direction, relative rotation does not exist between the push rod and the piston core rod of the injector, friction force during injection is reduced, the movable assembly is used for pushing injection, and the injection efficiency is improved. The injection speed and the injection force are kept consistent, and the experience feeling of a patient is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, and more specifically, to a low-friction syringe drug pushing mechanism. Background Art

[0002] A syringe is a commonly used medical device. It consists of a barrel with a small hole at the front end and a matching piston rod, and is used to inject liquid medicine into a patient. When the piston rod is pulled out, the liquid is sucked into the barrel through the small hole at the front end, and when the rod is pushed in, the liquid is extruded.

[0003] Chinese Patent Document CN 207356329 U discloses a medical syringe auxiliary propulsion device, which includes a syringe fixing sleeve, a propulsion device main body, and a propulsion screw; the propulsion device main body includes a fixing sleeve connection end and a hollow cylindrical screw sleeve with internal threads respectively arranged at both ends of the middle groove body; the syringe fixing sleeve is rotatably arranged at the fixing sleeve connection end, and the syringe fixing sleeve is a hollow cylinder; the propulsion screw penetrates through the screw sleeve, and the thread on the surface of the propulsion screw engages with the thread on the inner surface of the screw sleeve. One end of the propulsion screw in the propulsion device main body is provided with a syringe push rod fixing bayonet, and the other end is provided with a rotating handle. In the above technical solution, during injection, the propulsion screw and the syringe push rod fixing bayonet are placed, and the syringe push rod is fixed on the fixing bayonet and rotates together with the propulsion screw, which will cause the syringe push rod to rotate with the syringe. Since the syringe push rod and the syringe need to be sealed, the friction between the syringe push rod and the syringe during injection increases the resistance of rotating the rotating handle during injection, and the rotating handle needs to be rotated manually by a person, so the speed and force of pushing during injection cannot be kept consistent.

[0004] Therefore, it is necessary to propose a low-friction syringe drug pushing mechanism to solve the problems existing in the prior art. Summary of the Utility Model

[0005] A series of simplified concepts are introduced in the summary of the utility model, which will be further described in detail in the specific implementation section. The summary of the utility model does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0006] To solve the above problems, the present utility model provides a low-friction syringe drug-pushing mechanism, which includes a driving nut, a push rod, a guide sleeve and an annular bracket. The driving nut is rotatably arranged inside the annular bracket. Threads are arranged on the outer circumferential surface of the push rod, and the push rod is threadedly connected to the driving nut. The guide sleeve is fixedly arranged inside the annular bracket, and the push rod is slidably connected to the central hole of the guide sleeve. The diameter of the push rod is smaller than the diameter of the central hole of the guide sleeve. The guide sleeve and the driving nut are coaxially arranged, and the driving nut is power-connected to a power assembly;

[0007] On the circumferential surface of the central hole of the guide sleeve, a first limiting plane parallel to the central line of the guide sleeve is fixedly arranged. On the outer circumferential surface of the push rod, a second limiting plane parallel to the axis of the push rod is arranged. The first limiting plane and the second limiting plane are in contact and cooperate with each other.

[0008] Preferably, two first limiting planes are symmetrically arranged with the central line of the guide sleeve as the axis of symmetry, and two second limiting planes are symmetrically arranged with the axis of the push rod as the axis of symmetry.

[0009] Preferably, the annular bracket includes a first support ring, a second support ring and a connecting part that fixedly connects the first support ring and the second support ring together. The first support ring and the second support ring are coaxially arranged. The guide sleeve is fixedly arranged inside the first support ring, and the driving nut is rotatably arranged inside the second support ring.

[0010] Preferably, a convex block is fixedly arranged on the outer circumferential surface of the guide sleeve, and a groove is arranged at a position corresponding to the convex block on the inner wall of the first support ring. The convex block is clamped in the groove.

[0011] Preferably, the power assembly includes a gear ring, a spring winding mechanism and a gear. A gear ring is fixedly arranged on the end surface of the driving nut away from the guide sleeve. A spring winding mechanism is fixedly arranged on the outer wall of the second support ring. The spring winding mechanism is power-connected to the gear, and the gear is meshed with the gear ring;

[0012] The spring winding mechanism includes a housing. The housing is cylindrical. A ratchet is rotatably arranged inside the housing. One end of a gear shaft penetrates the end surface of the housing and extends into the housing and is fixedly connected to the ratchet. The other end of the gear shaft is fixedly connected to the gear. The inner end of the spring is fixedly connected to the housing, and the outer end of the spring is fixedly connected to the ratchet. An opening is formed on the outer circumferential surface of the housing, and a pawl is rotatably arranged on the opening. The pawl is clamped with the ratchet.

[0013] Preferably, a circumferential groove is formed on the inner wall of the second support ring, and a snap ring is detachably arranged in the groove.

[0014] Preferably, a connecting seat is fixedly arranged on the end surface of the first support ring away from the second support ring. The connecting seat is C-shaped. A fixing groove is formed on the inner wall of the connecting seat, and positioning grooves are symmetrically formed on the upper and lower side walls of the side wall of the fixing groove away from the first support ring.

[0015] Preferably, one end of a spring plate is fixedly connected to the side wall of the fixing groove away from the first support ring, and the other end of the spring plate is suspended and extends to the right side of the positioning groove.

[0016] Preferably, a spring hole is formed at a position on the side wall of the fixing groove close to the first support ring and opposite to the suspended end of the spring plate. A spring is arranged in the spring hole. One end of the spring is fixedly connected to the bottom surface of the spring hole, and the other end of the spring extends out of the spring hole and is fixedly connected to the spring plate.

[0017] Preferably, the annular bracket is made of a metal material or a polymer material.

[0018] Compared with the prior art, the utility model has at least the following beneficial effects:

[0019] For the low-friction syringe drug pushing mechanism of the utility model, a driving nut is used to rotate to drive a screw rod to move along the axis, so as to push the piston core rod of the syringe for injection. The push rod only makes an axial movement, and there is no relative rotation between the push rod and the piston core rod of the syringe, reducing the friction during injection. A moving component is used for pushing injection, keeping the injection speed and strength consistent, and increasing the patient experience.

[0020] For the low-friction syringe drug pushing mechanism of the utility model, other advantages, objectives and features of the utility model will be partially reflected by the following description, and will also be understood by those skilled in the art through the research and practice of the utility model. Description of the Drawings

[0021] The drawings are used to provide further understanding of the utility model, and constitute a part of the specification. Together with the embodiments of the utility model, they are used to explain the utility model, and do not constitute a limitation to the utility model. In the drawings:

[0022] Figure 1 is a schematic structural diagram of the low-friction syringe drug pushing mechanism disclosed by the utility model;

[0023] Figure 2 is a schematic structural diagram of the guide sleeve disclosed by the utility model;

[0024] Figure 3 is a schematic structural diagram of the push rod disclosed by the utility model;

[0025] Figure 4 is a schematic structural diagram of the bracket disclosed by the utility model;

[0026] Figure 5 is a schematic structural diagram of the radial cross-section of the guide sleeve installed in the first support ring disclosed by the utility model;

[0027] Figure 6Schematic cross-sectional view of the drive nut disclosed by the present utility model;

[0028] Figure 7 Schematic structural view of the coil spring mechanism disclosed by the present utility model;

[0029] Figure 8 Schematic cross-sectional view of the coil spring mechanism disclosed by the present utility model;

[0030] Figure 9 Schematic vertical cross-sectional view of the connecting seat disclosed by the present utility model;

[0031] Figure 10 Schematic horizontal cross-sectional view of the connecting seat disclosed by the present utility model. Detailed implementation manners

[0032] The following further describes the present utility model in detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it according to the description in the specification.

[0033] It should be understood that terms such as "having", "comprising", and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0034] As Figures 1-3 shown, a low-friction syringe drug-pushing mechanism includes a drive nut 1, a push rod 2, a guide sleeve 3, and an annular bracket 4. The drive nut 1 is rotatably arranged in the annular bracket 4. Threads are provided on the outer circumferential surface of the push rod 2, and the push rod 2 is threadedly connected to the drive nut 1. The guide sleeve 3 is fixedly arranged in the annular bracket 4, and the push rod 2 is slidably connected to the central hole of the guide sleeve 3. The diameter of the push rod 2 is smaller than the diameter of the central hole of the guide sleeve 3. The guide sleeve 3 and the drive nut 1 are coaxially arranged, and the drive nut 1 is power-connected to a power assembly;

[0035] A first limiting plane 5 parallel to the center line of the guide sleeve 3 is fixedly arranged on the circumferential surface of the central hole of the guide sleeve 3, and a second limiting plane 6 parallel to the axis of the push rod 2 is arranged on the outer circumferential surface of the push rod 2. The first limiting plane 5 and the second limiting plane 6 are in contact and cooperate with each other.

[0036] Two first limiting planes 5 are symmetrically arranged with the center line of the guide sleeve 3 as the axis of symmetry, and two second limiting planes 6 are symmetrically arranged with the axis of the push rod 2 as the axis of symmetry.

[0037] Working principle of the above technical solution: When the syringe needs to push the medicine, the medicine-pushing mechanism drives the driving nut 1 to rotate. The push rod 2 that is in threaded engagement with the driving nut 1 moves along the axial direction of the push rod 2 towards the syringe barrel 100 under the push of the driving nut, and pushes the syringe piston core rod 101 to slide into the syringe barrel 100 to complete the injection. A first limiting plane 5 is fixedly arranged on the inner wall of the central hole of the guide sleeve 3 sleeved on the outer circumference of the push rod 2, and a second limiting plane 6 along the axis direction of the push rod 2 is arranged on the outer circumferential surface of the push rod 2. When the guide sleeve 3 is sleeved on the push rod 2, the first limiting plane 5 contacts the second limiting plane 6, so that the push rod 2 cannot rotate along the axis and can only move along the axis direction. When the push rod 2 pushes the piston core rod of the syringe, the push rod 2 and the piston core rod remain stationary, avoiding friction between the rotation of the push rod and the end face of the piston core rod and reducing energy loss.

[0038] Two first limiting planes 5 are symmetrically arranged according to the center line of the central hole of the guide sleeve 3, and two second limiting planes 6 are symmetrically arranged according to the axis of the push rod 2. When the symmetrically arranged first limiting plane and the second limiting plane move the push rod 2, the smoothness of the movement of the push rod can be maintained.

[0039] Beneficial effects of the above technical solution:

[0040] The low-friction syringe medicine-pushing mechanism described in the present utility model uses the rotation of the driving nut to drive the screw rod to move along the axis, pushes the piston core rod of the syringe to inject, the push rod only makes axial movement, there is no relative rotation between the push rod and the syringe piston core rod, reduces the friction during injection, uses a moving component for injection, keeps the injection speed and strength consistent, and increases the patient experience.

[0041] In one embodiment, as Figures 4-5 shown, the annular bracket 4 includes a first support ring 41, a second support ring 42 and a connecting portion 43 that fixedly connects the first support ring 41 and the second support ring 42. The first support ring 41 and the second support ring 42 are coaxially arranged. The guide sleeve 3 is fixedly arranged in the first support ring 41, and the driving nut 1 is rotatably arranged in the second support ring 42.

[0042] A convex block 7 is fixedly arranged on the outer circumferential surface of the guide sleeve 3, and a groove 8 is arranged at a position corresponding to the convex block on the inner wall of the first support ring 41. The convex block 7 is clamped in the groove 8.

[0043] Working principle of the above technical solution: The annular bracket 4 includes a first support ring 41, a second support ring 42, and a connecting portion 43 that fixedly connects the first support ring 41 and the second support ring 42. The first support ring 41 and the second support ring 42 are coaxially arranged. The guide sleeve 3 is fixedly arranged inside the first support ring 41. The driving nut 1 is rotatably arranged inside the second support ring 42. The bump 7 on the outer circumference of the guide sleeve 3 is clamped in the groove 8 on the first support ring 41, which can prevent the guide sleeve from rotating along the axis.

[0044] In one embodiment, as Figures 6-8 shown, the power assembly includes a gear ring 9, a spiral spring mechanism 10, and a gear 11. A gear ring 9 is fixedly arranged on the end face of the driving nut 1 away from the guide sleeve 3. A spiral spring mechanism 10 is fixedly arranged on the outer wall of the second support ring 42. The spiral spring mechanism 10 is power-connected to the gear 11, and the gear 11 is meshed with the gear ring 9;

[0045] The spiral spring mechanism 10 includes a housing 110. The housing 110 is cylindrical. A ratchet wheel 103 is rotatably arranged inside the housing 110. One end of a gear shaft 18 penetrates through the end face of the housing 110 and extends into the housing 110 and is fixedly connected to the ratchet wheel 103. The other end of the gear shaft 18 is fixedly connected to the gear 11. The inner end of the spiral spring 102 is fixedly connected to the housing 110. The outer end of the spiral spring 102 is fixedly connected to the ratchet wheel 103. An opening 104 is formed on the outer circumference of the housing 110. A pawl 105 is rotatably arranged on the opening 104. The pawl 105 is clamped with the ratchet wheel 103.

[0046] A circumferential slot 12 is formed on the inner wall of the second support ring 42. A snap ring 13 is detachably arranged in the slot 12.

[0047] Working principle of the above technical solution: The power assembly includes a spiral spring mechanism 10, a gear ring 9, and a gear 11. During injection preparation, turn the handle 108 installed on the end face of the gear shaft to tighten the spiral spring 102 by the ratchet wheel 103. Since the pawl 105 is pressed on the ratchet wheel 103 under the action of the spring 106, the ratchet wheel 103 cannot reverse. One end of the spring 106 is fixedly connected to the side wall of the opening 104, and the other end of the spring 106 is fixedly connected to the lower end face of the pawl on the side away from the ratchet wheel 103. After the injection is prepared, press the end of the pawl located outside the housing 110 to release the ratchet wheel 103. The ratchet wheel 103 rotates under the action of the spiral spring 102. The ratchet wheel 103 drives the driving nut 1 to rotate through the gear shaft 18, the gear 11, and the gear ring 9. The rotation of the driving nut 1 pushes the push rod 2 to move, thereby pushing the piston core rod 101 to move and completing the injection.

[0048] After the driving nut 1 is installed into the second support ring 42, the snap ring 13 is snap-fitted into the slot 12 to prevent the axial movement of the driving nut 1. To prevent the friction between the driving nut and the second support ring 42 during rotation, a needle roller bearing can be provided between the driving nut 1 and the second support ring 42.

[0049] The snap ring can be selected from the standard parts of the open snap ring with a size suitable for the second support ring.

[0050] In one embodiment, as Figures 9-10 shown, a connecting seat 44 is fixedly provided on the end face of the first support ring 41 away from the second support ring 42. The connecting seat 44 is C-shaped, and a fixing groove 45 is opened on the inner wall of the connecting seat 44. Positioning grooves 14 are symmetrically opened on the upper and lower side walls of the fixing groove 45 away from the side of the first support ring 41.

[0051] One end of a spring plate 15 is fixedly connected to the side wall of the fixing groove 45 away from the first support ring 41, and the other end of the spring plate 15 is suspended and extends to the right side of the positioning groove 14.

[0052] A spring hole 16 is opened at a position on the side wall of the fixing groove 45 close to the first support ring 41 opposite to the suspended end of the spring plate 15. A spring 17 is arranged in the spring hole 16. One end of the spring 17 is fixedly connected to the bottom surface of the spring hole 16, and the other end of the spring 17 extends out of the spring hole 16 and is fixedly connected to the spring plate 15.

[0053] The working principle of the above technical solution: The connecting seat 44 is provided for fixing the syringe. The shape inside the C-shape of the connecting seat 44 is adapted to the outer circumference of the syringe barrel 100. The wing plate at the tail of the syringe barrel extends into the fixing groove 45, and the outer circumference of the syringe barrel 100 leans against the opening of the connecting seat. The shape of the positioning groove 14 is adapted to the shape of the wing plate at the tail of the syringe barrel 100. The suspended end of the spring plate 15 faces the opening direction of the C-shape of the connecting seat, and the suspended end of the spring plate tilts towards the first support ring 41. When installing the syringe, the wing plate at the tail of the syringe barrel 100 enters the positioning groove 14 from the gap where the spring plate tilts and is pressed by the spring plate in the positioning groove 14. The spring 17 is a compression spring, which may increase the pressure of the spring plate on the wing plate of the syringe barrel 100 to keep the flowmeter stable. The syringe has the outer shape of the syringe specified by the national standard and will not be elaborated here.

[0054] In one embodiment, the annular bracket 4 is made of a metal material or a polymer material.

[0055] The working principle of the above technical solution: The annular bracket 4 can be made of a metal material or a polymer material.

[0056] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0057] In the present utility model, unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection or communication with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0058] Although the embodiments of the present utility model have been disclosed as above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present utility model. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present utility model is not limited to the specific details and the examples shown and described herein.

Claims

1. A low-friction syringe drug-pushing mechanism, characterized in that, It includes a driving nut (1), a push rod (2), a guide sleeve (3) and an annular bracket (4). The driving nut (1) is rotatably arranged in the annular bracket (4). Threads are provided on the outer circumferential surface of the push rod (2), and the push rod (2) is threadedly connected to the driving nut (1). The guide sleeve (3) is fixedly arranged in the annular bracket (4), and the push rod (2) is slidably connected to the central hole of the guide sleeve (3). The diameter of the push rod (2) is smaller than the diameter of the central hole of the guide sleeve (3). The guide sleeve (3) and the driving nut (1) are coaxially arranged, and the driving nut (1) is power-connected to a power assembly; On the circumferential surface of the central hole of the guide sleeve (3), a first limiting plane (5) parallel to the central axis of the guide sleeve (3) is fixedly arranged. On the outer circumferential surface of the push rod (2), a second limiting plane (6) parallel to the axis of the push rod (2) is arranged. The first limiting plane (5) and the second limiting plane (6) are in contact and cooperate with each other.

2. The low-friction syringe drug-pushing mechanism according to claim 1, characterized in that, Two first limiting planes (5) are symmetrically arranged with the central axis of the guide sleeve (3) as the axis of symmetry, and two second limiting planes (6) are symmetrically arranged with the axis of the push rod (2) as the axis of symmetry.

3. The low-friction syringe drug-pushing mechanism according to claim 1, characterized in that, The annular bracket (4) includes a first support ring (41), a second support ring (42) and a connecting part (43) that fixedly connects the first support ring (41) and the second support ring (42). The first support ring (41) and the second support ring (42) are coaxially arranged. The guide sleeve (3) is fixedly arranged in the first support ring (41), and the driving nut (1) is rotatably arranged in the second support ring (42).

4. The low-friction syringe drug-pushing mechanism according to claim 3, characterized in that, On the outer circumferential surface of the guide sleeve (3), a convex block (7) is fixedly arranged. At a position corresponding to the convex block on the inner wall of the first support ring (41), a groove (8) is arranged, and the convex block (7) is clamped in the groove (8).

5. The low-friction syringe drug-pushing mechanism according to claim 3, wherein The power assembly includes a gear ring (9), a coil spring mechanism (10) and a gear (11). A gear ring (9) is fixedly arranged on the end face of the driving nut (1) away from the guide sleeve (3). A coil spring mechanism (10) is fixedly arranged on the outer wall of the second support ring (42). The coil spring mechanism (10) is power-connected to the gear (11), and the gear (11) is meshed with the gear ring (9); The coil spring mechanism (10) includes a housing (110). The housing (110) is cylindrical. A ratchet (103) is rotatably arranged in the housing (110). One end of a gear shaft (18) penetrates the end face of the housing (110) and extends into the housing (110) and is fixedly connected to the ratchet (103). The other end of the gear shaft (18) is fixedly connected to the gear (11). The inner end of a coil spring (102) is fixedly connected to the housing (110), and the outer end of the coil spring (102) is fixedly connected to the ratchet (103). An opening (104) is formed on the outer circumferential surface of the housing (110), and a pawl (105) is rotatably arranged on the opening (104), and the pawl (105) is clamped with the ratchet (103).

6. The low-friction syringe drug-pushing mechanism according to claim 3, characterized in that, A circumferentially extending clamping groove (12) is formed on the inner wall of the second support ring (42), and a snap ring (13) is detachably arranged in the clamping groove (12).

7. The low-friction syringe drug-pushing mechanism according to claim 3, wherein, On the end face of the first support ring (41) on the side away from the second support ring (42), a connecting seat (44) is fixedly arranged. The connecting seat (44) is C-shaped, and a fixing groove (45) is formed on the inner wall of the connecting seat (44). Positioning grooves (14) are symmetrically formed on the upper and lower sides of the side wall of the fixing groove (45) on the side away from the first support ring (41).

8. The low-friction syringe drug-pushing mechanism according to claim 7, wherein One end of a spring plate (15) is fixedly connected to the side wall of the fixing groove (45) on the side away from the first support ring (41), and the other end of the spring plate (15) is suspended and extends to the right side of the positioning groove (14).

9. The low-friction syringe drug-pushing mechanism according to claim 8, wherein, A spring hole (16) is formed at a position on the side wall of the fixing groove (45) close to the first support ring (41) opposite to the suspended end of the spring plate (15). A spring (17) is arranged in the spring hole (16). One end of the spring (17) is fixedly connected to the bottom surface of the spring hole (16), and the other end of the spring (17) extends out of the spring hole (16) and is fixedly connected to the spring plate (15).

10. The low-friction syringe drug pushing mechanism according to claim 1, characterized in that, The annular bracket (4) is made of a metal material or a polymer material.

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