A pre-filled syringe cap

Abstract

The utility model discloses a kind of pre-filled syringe protective caps, belong to medical instrument technical field, including the protective cap body, needle tip cavity, conical cavity, sliding cavity and connecting cavity are sequentially arranged in its inside along the axial direction. The sliding cavity side wall is provided with exhaust hole, the inside sliding is provided with silica gel block extending to connecting cavity, and connecting cavity diameter is greater than sliding cavity diameter. When syringe is inserted, realize phased exhaust function: initial stage is discharged compressed air by exhaust hole, final stage silica gel block slidingly closes exhaust hole, to avoid external pollution. While optimizing needle support stability, the utility model solves the problem of falling caused by poor exhaust of traditional protective cap, while taking into account aseptic seal and operation reliability, suitable for high health requirements injection scene such as vaccine, biological preparation.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a pre-filled syringe cap. Background Technology

[0002] Pre-filled syringes, such as CN207076005U, are disposable syringes pre-filled with medication or vaccine and sterilized and sealed. They can be used directly for clinical injection without the need for manual aspiration by medical personnel. They are widely used in vaccination, emergency care, and biological agent injection. The needle portion is typically equipped with a protective cap covering the tip of the syringe to maintain sterility inside the syringe and prevent contact between the medication and the external environment.

[0003] Traditional syringe caps compress the air inside when the needle is inserted, creating a separation force between the cap and the syringe, causing the cap to detach. As shown in invention patent CN106317507A, venting grooves are provided around the inside of the cap, which alleviates the problem, but these grooves, connected to the outside, can still lead to needle tip contamination. Furthermore, this type of cap is prone to slight movement after needle insertion, causing friction between the needle tip and the inner wall of the cap, leading to needle tip dulling or coating peeling, increasing injection pain. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art. Firstly, it provides a pre-filled syringe cap with optimized venting function. Secondly, it improves the fixing relationship between the syringe and the cap.

[0005] To achieve at least one of the above objectives, the present invention provides the following technical solution: a pre-filled syringe cap, comprising a cap body, wherein the inner side of the cap is provided with a needle tip cavity, a conical cavity, a sliding cavity and a connecting cavity arranged sequentially along the axial direction; the side wall of the sliding cavity is provided with an exhaust hole, and a silicone block is slidably disposed on the inner side, the silicone block extending into the connecting cavity, the diameter of the connecting cavity being greater than the diameter of the sliding cavity.

[0006] Furthermore, a fixed cavity is provided between the conical cavity and the sliding cavity, with the diameter of the sliding cavity being greater than the diameter of the fixed cavity. The fixed cavity restricts the sliding range of the silicone block, preventing excessive displacement that could lead to seal failure. Simultaneously, the diameter difference between the sliding cavity and the fixed cavity forms a stepped structure, ensuring that the silicone block stably adheres to the vent hole after compression.

[0007] Furthermore, the silicone block has a recess in its center, forming a thin wall. This thin-wall structure reduces the rigidity of the silicone block, making it easier to deform during needle insertion. Notably, the silicone block used as a medical device is made of medical-grade silicone.

[0008] Furthermore, the recess has a conical hole structure, with the diameter at the end near the needle tip cavity being smaller than the diameter at the end away from it.

[0009] Furthermore, the silicone block has a conical hole in its center, with the diameter of the conical hole near the needle tip cavity being smaller than the diameter of the end away from the needle tip cavity. The conical hole guides the needle tip for precise insertion, reducing resistance. It also better alleviates the puncture resistance between the silicone block and the needle tip.

[0010] Furthermore, the connecting cavity is also provided with an internal thread. This thread engages with the external thread of the syringe, enhancing the connection strength between the cap and the syringe.

[0011] Furthermore, a chamfer is provided between the transition surface of the connecting cavity and the cap body. The chamfer provides a smooth transition, facilitating quick alignment when the syringe is inserted.

[0012] Furthermore, a reinforcing plate is provided on the inner side of the conical cavity. The reinforcing plate enhances the deformation resistance of the conical cavity.

[0013] Furthermore, a support ring is provided on the outer circumference of the cap body. The function of the support ring is to facilitate the movement of the cap body on the vibratory plate and conveyor belt during assembly, and to provide support for the cap body to be inserted into the hole of the perforated tray, so as to facilitate mechanical connection and alignment with the syringe.

[0014] The advantages and beneficial effects of this utility model are as follows: The sliding cavity inside the cap body cooperates with the silicone block to form a dynamic seal. When the syringe is inserted into the connecting cavity, the syringe needle passes through the silicone block, and the cylindrical connecting tube of the needle and the syringe body abuts against the silicone block. At this time, the vent hole can still release air. When the syringe continues to be assembled into the cap body, the cylindrical connecting tube will push the silicone block to close the vent hole. After the silicone block closes the vent hole, it can also be limited by the fixed cavity to maintain the stability of the seal. In addition, the liquid level needle part of the silicone block provides a certain support to prevent it from shaking. Attached Figure Description

[0015] Figure 1 This is a cross-sectional structural diagram of the protective cap of this utility model;

[0016] Reference numerals: 1-Cap body, 2-Needle tip cavity, 3-Conical cavity, 4-Sliding cavity, 5-Connecting cavity, 6-Exhaust hole, 7-Silicone block, 8-Fixing cavity, 9-Recess, 10-Internal thread, 11-Chamfer, 12-Reinforcing plate, 13-Support ring. Detailed Implementation

[0017] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0018] Example 1

[0019] like Figure 1 As shown, a pre-filled syringe cap includes a cap body 1. The inner side of the cap is sequentially provided with a needle tip cavity 2, a conical cavity 3, a sliding cavity 4, and a connecting cavity (5) along the axial direction. The needle tip cavity 2 is located at the front end of the cap and is a cylindrical cavity with the smallest diameter, used to precisely accommodate the sharp part of the syringe needle. The length of the cavity is designed to ensure that the needle tip does not touch the end of the cavity after insertion. The conical cavity 3 connects the needle tip cavity 2 and the sliding cavity 4, forming a guiding slope. The inner wall of the sliding cavity 4 is provided with reinforcing plates 12 evenly distributed in a circular array to enhance structural rigidity. Multiple vent holes 6 with diameters between 0.5-1.0 mm are evenly opened on the side wall of the sliding cavity 4. An axially sliding silicone block 7 is provided inside the silicone block 7, which extends into the connecting cavity 5. The diameter of the connecting cavity 5 is larger than the diameter of the sliding cavity 4. A recess 9 is provided in the middle of the silicone block 7, making the silicone block 7 thicker on the outer edge and thinner in the middle. A support ring 13 is provided circumferentially on the outer side of the cap body.

[0020] Example 2,

[0021] A pre-filled syringe cap differs from Embodiment 1 in that the connecting cavity 5 is further provided with an internal thread 10. This thread connects to the external thread on the cylindrical connecting tube of the syringe.

[0022] Example 3

[0023] A pre-filled syringe cap differs from Embodiment 1 in that a chamfer 11 is provided between the transition surface of the connecting cavity 5 and the cap body 1. A concave hole is formed through the recess in the middle of the silicone block 7.

[0024] The working principle of this invention lies in the fact that the protective cap achieves compressed air release and aseptic sealing through the synergistic effect of staged venting and dynamic sealing. In the initial stage, when the needle enters the conical cavity, the air pressure inside the cap rises, and the silicone block is in the initial position of the sliding cavity. Compressed air is discharged outward through the unsealed vent hole. During deep insertion, the syringe cylindrical connecting tube reaches the end of the silicone block, and the silicone block is axially displaced by the syringe's thrust. The outer edge of the silicone block adheres tightly to the inner wall of the sliding cavity, completely sealing the vent hole during movement. Finally, the internal thread of the fixed cap is tightened with the external thread of the syringe, and the fixed cavity and the syringe cylindrical connecting tube lock the silicone block in place, maintaining a seal.

[0025] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A pre-filled syringe cap comprising a cap body (1), characterised in that: The inner side of the cap is provided with a needle tip cavity (2), a conical cavity (3), a sliding cavity (4) and a connecting cavity (5) in sequence along the axial direction; the side wall of the sliding cavity (4) is provided with an exhaust hole (6), and a silicone block (7) is slidably arranged inside it. The silicone block (7) extends into the connecting cavity (5), and the diameter of the connecting cavity (5) is larger than the diameter of the sliding cavity (4).

2. The pre-filled syringe cap of claim 1, wherein: A fixed cavity (8) is provided between the conical cavity (3) and the sliding cavity (4), and the diameter of the sliding cavity (4) is larger than the diameter of the fixed cavity (8).

3. The pre-filled syringe cap of claim 1, wherein: The silicone block (7) has a recess (9) in the middle, and the recess (9) forms a thin-walled structure.

4. The pre-filled syringe cap of claim 3, wherein: The recess (9) is a conical hole structure, with the diameter of the end near the needle tip cavity (2) being smaller than the diameter of the end away from it.

5. The pre-filled syringe cap of claim 1, wherein: The inner wall of the connecting cavity (5) is provided with an internal thread (10).

6. The pre-filled syringe cap of claim 1, wherein: A chamfer (11) is provided between the transition surface of the connecting cavity (5) and the cap body (1).

7. The pre-filled syringe cap of claim 1, wherein: The inner side of the conical cavity (3) is provided with a radially extending reinforcing plate (12).

8. The pre-filled syringe cap of claim 1, wherein: The outer circumferential support ring (13) is provided on the cap body (1).

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