A flow delay resistant dispenser

Abstract

The technical scheme of the present application is a kind of anti-delay flow dosing device, including cylinder, push rod, rubber plug, sheath, the sheath is sleeved in the front end of cylinder and realizes interference fit, the rubber plug is sleeved in the front end of push rod, the push rod is inserted into the cylinder and the rubber plug outside surface at the front end is interference fit with the inner wall of cylinder, the bottom surface of rubber plug is provided with stepped inner hole, the stepped inner hole includes neck and bottom surface cavity part, the front end of push rod is thin rod part, the front end of thin rod part has end head positioning part, the outer diameter of end head positioning part is greater than the inner diameter of neck and less than the inner diameter of bottom surface cavity part, the outer diameter of thin rod part is less than the inner diameter of neck, the height of thin rod part is greater than the depth of neck, the height of end head positioning part is less than the depth of bottom surface cavity part, the total height of thin rod part and end head positioning part is greater than the depth of stepped inner hole.The present application can effectively prevent the occurrence of drug delay flow in dosing device.

Description

Technical Field

[0001] This invention relates to a drug delivery device, and more particularly to an anti-drip drug delivery device. Background Technology

[0002] Drug delivery devices are commonly used medical devices, primarily used to inject liquid or solid fluid drugs into the human or animal body, or for drug preparation and proportioning. Current drug delivery device structures include... Figure 1 As shown, it mainly includes a cylinder 1', a push rod 2', a rubber stopper 3', and a protective sleeve 4'. The rubber stopper 3' is fitted onto the front end of the push rod 2'. The interference fit between the minimum inner diameter of the stepped conical inner hole of the rubber stopper 3' and the head of the push rod 2' is large. After the push rod 2' is assembled with the rubber stopper 3', the surfaces of the two are in close contact. It is difficult to remove the push rod 2' after it is installed. After assembly, the front end face of the rubber stopper 3' will not deform much during drug injection. The initial design consideration was the function of injecting drugs and achieving the function of rapid drug injection. No other issues were considered.

[0003] However, as its application expands, the aforementioned drug delivery device exhibits a drawback: when the injection process needs to be stopped, liquid continues to leak from the front end of the cylinder 1' even after the push rod 2' is stopped. This is due to fluid inertia and is a persistent problem that usually goes unnoticed. This is especially problematic in situations where the delivery device contains toxic or harmful drugs, where continued leakage at the front end upon stopping the injection is unacceptable.

[0004] When precise drug delivery is required, especially when it needs to be stopped midway, the above-mentioned drug delivery device cannot achieve the purpose. Therefore, it is necessary to invent a drug delivery device that can still achieve precise drug delivery when drug delivery is stopped midway. Summary of the Invention

[0005] To address the aforementioned problems, this invention aims to provide an anti-spillage drug delivery device with a novel and unique structure. It improves the structure of the push rod and rubber stopper based on the existing drug delivery device structure, thereby achieving an effective anti-spillage effect.

[0006] The present invention provides a flow-resistant drug delivery device, comprising a cylinder, a push rod, a rubber stopper, and a sheath. The sheath is fitted onto the front end of the cylinder, achieving an interference-sealed fit. The rubber stopper is fitted onto the front end of the push rod. The push rod is inserted into the cylinder, and the outer surface of the rubber stopper at the front end is interference-sealed with the inner wall of the cylinder. The bottom surface of the rubber stopper has a stepped inner hole, which includes a neck and a bottom cavity. The front end of the push rod is a thin rod portion, with an end positioning portion at its front end. The outer diameter of the end positioning portion is larger than the inner diameter of the neck and smaller than the inner diameter of the bottom cavity. The outer diameter of the thin rod portion is smaller than the inner diameter of the neck. The height of the thin rod portion is greater than the depth of the neck. The height of the end positioning portion is less than the depth of the bottom cavity. The total height of the thin rod portion and the end positioning portion is greater than the depth of the stepped inner hole.

[0007] Preferably, a conical column extends upward from the center of the top surface of the rubber stopper, and a conical transition hole is provided at the front end of the cylinder, wherein the conical column is adapted to the conical transition hole.

[0008] Preferably, the top surface of the rubber stopper is a plane.

[0009] Preferably, the top surface of the rubber stopper is an inclined surface, and the inclination direction is gradually downward from the outside to the inside.

[0010] Preferably, a protruding extrusion part is provided at the center of the top surface of the end positioning part, the total height of the end positioning part and the extrusion part is less than the depth of the bottom cavity part, and the size of the extrusion part is adapted to the size of the bottom of the conical column.

[0011] Preferably, the cross-section of the push rod is cross-shaped, and the widest part of the rod corresponds to the inner wall of the cylinder.

[0012] Preferably, the outer wall of the rubber stopper is provided with multiple annular sealing strips.

[0013] Preferably, the bottom surface of the bottom cavity is a plane.

[0014] This invention improves the rubber stopper and push rod of existing drug delivery devices. During drug injection, the rubber stopper deforms, and when the injection stops and the hand is released, the rubber stopper immediately returns to its original state, creating a negative pressure in the space at the front end of the rubber stopper inside the cylinder and increasing the space. The drug inside is forced to retreat, effectively preventing drug spillage. Attached Figure Description

[0015] Figure 1 A cross-sectional view of an existing drug delivery device structure;

[0016] Figure 2 This is an exploded structural diagram of the present invention;

[0017] Figure 3 This is a cross-sectional view of the structure of the present invention when the push rod is manually released;

[0018] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0019] Figure 5 This is a schematic diagram of the structure of the present invention when the push rod is held and pushed forward;

[0020] Figure 6 for Figure 5 A magnified view of a section at point B in the middle;

[0021] Wherein: 1—cylinder; 11—conical transition hole; 2—push rod; 21—thin rod part; 22—end positioning part; 23—extrusion part; 3—rubber plug; 31—conical column; 32—sealing strip; 4—sheath; 5—stepped inner hole; 51—neck; 52—bottom cavity part. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] like Figures 2 to 6 As shown, the present invention provides an anti-drip drug delivery device, including a cylinder 1, a push rod 2, a rubber stopper 3, and a sheath 4. The sheath 4 is fitted onto the front end of the cylinder 1 to achieve an interference seal. The rubber stopper 3 is fitted onto the front end of the push rod 2. The push rod 2 is inserted into the cylinder 1, and the outer side of the rubber stopper 3 at the front end is interference-sealed with the inner wall of the cylinder 1. The bottom surface of the rubber stopper 3 is provided with a stepped inner hole 5. The stepped inner hole 5 includes a neck 51 and a bottom cavity 52. ​​The front end of the push rod 2 is a thin rod 21, and the front end of the thin rod 21 has an end positioning part 22. The outer diameter of the end positioning part 22 is greater than the inner diameter of the neck 51 and less than the inner diameter of the bottom cavity 52. ​​The outer diameter of the thin rod 21 is less than the inner diameter of the neck 51. The height of the thin rod 21 is greater than the depth of the neck 51. The height of the end positioning part 22 is less than the depth of the bottom cavity 52. ​​The total height of the thin rod 21 and the end positioning part 22 is greater than the depth of the stepped inner hole 5.

[0024] Based on the above scheme, a conical column 31 extends upward from the center of the top surface of the rubber stopper 3, and a conical transition hole 11 is provided at the front end of the cylinder 1. The conical column 31 and the conical transition hole 11 are adapted to each other, so that when the injection reaches the rear end, the drug can be better injected from the syringe at the front end.

[0025] The top surface of the rubber stopper 3 is a plane.

[0026] As a better approach, the top surface of the rubber stopper 3 is an inclined surface, with the inclination direction gradually downward from the outside to the inside, which facilitates the deformation of the rubber stopper and makes the spatial change at the front end of the rubber stopper greater due to the deformation of the rubber stopper.

[0027] Furthermore, a protruding extrusion part 23 is provided at the center of the top surface of the end positioning part 22. The total height of the end positioning part 22 and the extrusion part 23 is less than the depth of the bottom cavity part 52. The size of the extrusion part 23 is adapted to the size of the bottom of the conical column 31.

[0028] Furthermore, the cross-section of the push rod 2 is cross-shaped, and the widest part of the rod corresponds to the inner wall of the cylinder 1. This facilitates consistent axial movement when the push rod 2 is pushed forward.

[0029] Furthermore, the outer wall of the rubber stopper 3 is provided with multiple annular sealing strips 32 to achieve a better sealing effect for the drug.

[0030] Finally, the bottom surface of the bottom cavity portion 52 is a plane.

[0031] This invention has two states when in use:

[0032] The first state is when the hand-held pusher 2 pushes the drug forward, and the structure at this time is as follows: Figure 5 and Figure 6 As shown, the squeezing part 23 at the front end of the push rod 2 presses against the top surface of the bottom cavity 52, causing the rubber stopper 3 to deform upward. The top surface of the rubber stopper 3 bulges upward, and the drug in front of the rubber stopper 3 is pushed forward and squeezed out. This process is the normal drug administration state.

[0033] The second state is when the medication is stopped and the push rod 2 is released. The structure at this time is as follows: Figure 3 and Figure 4 As shown, there is a gap between the squeezing part 23 in front of the push rod 2 and the top surface of the bottom cavity 52 inside the rubber stopper 3, and the two do not contact each other. The rubber stopper 3 returns to its initial state, and the top surface of the rubber stopper 3 presents a normal concave state. This process is the state of stopping drug administration.

[0034] In both states, when the outer wall of the rubber stopper 3 contacts the same position of the cylinder 1, the size of the cavity in front of the rubber stopper 3 will be significantly different. In the first state, the space in front of the rubber stopper 3 is significantly smaller. At this time, the push rod 2 is pushed forward to continuously administer the drug. When it is necessary to stop the drug, the push rod 2 is released. Because the total height of the end positioning part 22 and the squeezing part 23 is less than the depth of the bottom cavity part 52, the push rod 2 will automatically retract. The top surface of the push rod 2 and the top surface of the bottom cavity part 52 separate. The top of the rubber stopper 3 deforms downward and returns to the initial state. The cavity in front of the rubber stopper 3 increases. The drug at the outlet of the drug delivery device flows back into the drug delivery device under the negative pressure in the drug storage cavity, preventing the drug from flowing back at the outlet of the drug delivery device, and finally achieving the purpose of precise drug delivery.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, equivalent changes, or alterations made to the above embodiments based on the technical principles of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A kind of anti-continuous flow dosing device, including barrel (1), push rod (2), rubber plug (3), sheath (4), the sheath (4) is set at barrel (1) front end both and realizes interference fit, the rubber plug (3) is set at the front end of push rod (2), the push rod (2) is inserted into barrel (1) and the rubber plug (3) outside at the front end is interference fit with the inner wall of barrel (1), it is characterized by: The bottom surface of the rubber plug (3) is provided with a stepped inner hole (5), the stepped inner hole (5) comprises a neck (51) and a bottom cavity (52), the front end of the push rod (2) is a thin rod part (21), the front end of the thin rod part (21) has an end positioning part (22), the outer diameter of the end positioning part (22) is greater than the inner diameter of the neck (51) and less than the inner diameter of the bottom cavity (52), the outer diameter of the thin rod part (21) is less than the inner diameter of the neck (51), the height of the thin rod part (21) is greater than the depth of the neck (51), the height of the end positioning part (22) is less than the depth of the bottom cavity (52), and the total height of the thin rod part (21) and the end positioning part (22) is greater than the depth of the stepped inner hole (5); the top surface of the rubber plug (3) extends upward to a conical column (31) at the center, the front end of the barrel (1) is provided with a conical transition hole (11), and the conical column (31) is matched with the conical transition hole (11); the top surface of the end positioning part (22) is provided with a protruding extrusion part (23) at the center, and the total height of the end positioning part (22) and the extrusion part (23) is less than the depth of the bottom cavity (52), and the size of the extrusion part (23) is matched with the size of the bottom of the conical column (31).

2. A flow-delaying dispenser according to claim 1, characterised in that: The top surface of the rubber plug (3) is a plane.

3. A flow-delaying dispenser according to claim 1, wherein: The top surface of the rubber plug (3) is an inclined surface, and the inclined direction is gradually inclined downward from the outside to the inside.

4. A flow-delaying dispenser according to claim 1, wherein: The cross section of the rod body of the push rod (2) is a cross, and the size of the widest part of the rod body corresponds to the inner wall of the barrel (1).

5. A flow-delaying dispenser according to claim 1, wherein: The outer side wall of the rubber plug (3) is provided with a plurality of annular sealing strips (32).

6. A flow-delaying dispenser according to claim 1, wherein: The bottom surface of the bottom cavity (52) is a plane.

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