Auxiliary tool for testing sliding force of pre-filled syringe

Abstract

The utility model provides an auxiliary tool for testing the sliding force of a pre-filled syringe. The auxiliary tool comprises a box, a limiting groove which is arranged in the box and is used for placing the syringe, and a pressing plate which is arranged on the box in an opening and closing manner, one side of the box is provided with a limiting assembly directly facing the tail part of the injector piston and used for preventing the injector piston from being separated from the injector; the limiting assembly comprises a spring capable of being compressed by the tail of the piston so that the limiting assembly can abut against the tail of the piston all the time. The limiting groove is formed in the box body, so that syringes can be conveniently, rapidly and orderly placed in the limiting groove, the syringes are limited, and the syringes are easy and convenient to place; according to the utility model, the limiting assembly is arranged for preventing the sealing property from being damaged after the piston moves; the spring is arranged in the limiting assembly, and the tail part of the piston is jacked after pre-tightening force is applied to the spring initially, so that the problem that the top plate does not jack the tail part of the piston due to the height error of liquid medicine can be avoided; and a gap between the limiting assembly and the tail part of the piston due to the fact that the injector possibly shrinks after sterilization is finished can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of syringe technology, and in particular to an auxiliary tool for testing the sliding force of a pre-filled syringe. Background Technology

[0002] In laboratory steam sterilization experiments, pre-filled syringes are sterilized by placing 10 syringes in a negative suction bag and then into an autoclave. Due to the increased temperature, the medication inside the syringe expands, causing the piston to easily shift and affecting its seal. This results in inconsistencies between the initial and final sliding force test data on the sliding force testing device. While new sterilization equipment can be used, it is expensive. To reduce experimental costs, a self-made syringe sterilization experimental fixture is proposed to assist in the sliding force testing of pre-filled syringes.

[0003] Chinese utility model patent CN203555974U, published on April 23, 2014, discloses a device for terminal sterilization of pre-filled preparations. It can be assembled with pre-filled syringes containing contents. The device includes a lower plate, a middle plate, an upper plate, and a fixing and adjusting device. The device consists of three layers connected by long bolts. After the pre-filled syringes are filled and sealed with rubber stoppers, they are arranged in the same direction in a pre-filled syringe rack of the corresponding size. The rack is either included with the pre-filled syringes at the factory or customized according to discharge regulations. This patent is used to assemble pre-filled syringes of various sizes to achieve steam sterilization of the pre-filled contents, meeting aseptic requirements. However, this patent is not only structurally complex and difficult to assemble, but also, because the upper plate structure is rigidly fitted to the syringe, it cannot prevent the piston from not being properly tightened due to height errors (within a reasonable range) in the injected medication. Summary of the Invention

[0004] To address the aforementioned technical problems, this utility model proposes an auxiliary tool for testing the sliding force of a pre-filled syringe. This tool solves the problems in the prior art where the clamps used for sterilizing pre-filled syringes have complex structures, are difficult to assemble, and cannot prevent the piston from not being properly tightened due to height errors in the liquid inside the syringe.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] An auxiliary tool for testing the sliding force of a pre-filled syringe includes a box, a limiting groove inside the box for placing the syringe, and a pressure plate that opens and closes on the box. One side of the box has a limiting component facing the syringe piston tail to prevent piston displacement from compromising the seal. The limiting component includes a spring that can be compressed by the piston tail to ensure the limiting component always presses firmly against the piston tail. This invention, by providing a limiting groove in the box, facilitates quick and easy placement of the syringe neatly into the groove, limiting the syringe's position and simplifying syringe placement. By incorporating a spring in the limiting component and initially applying a pre-tightening force to press against the piston tail, this invention avoids the problem of the top plate not pressing firmly against the piston tail due to errors in the height of the liquid solution. Furthermore, it prevents gaps between the limiting component and the piston tail that may occur after sterilization due to syringe shrinkage.

[0007] Furthermore, in order to compress the spring on the one hand and adjust the position of the limiting component to accommodate syringes of multiple lengths on the other hand, the limiting component is adjustablely connected to the box.

[0008] Furthermore, in order to facilitate the adjustment of the position of the limiting component, the limiting component also includes an adjustable limiting rod connected to the box, with one end of the spring connected to the limiting rod and the other end connected to the top plate to hold the piston tail.

[0009] Furthermore, in order to make the adjustment structure and adjustment method of the limiting rod simpler, the limiting rod is a screw rod, the box is provided with a through hole, and a nut is provided in the through hole for the screw rod to pass through, and the screw rod and the nut are threadedly connected.

[0010] Furthermore, in order to make the adjustment structure and adjustment method of the limiting rod simpler, the limiting rod is a screw rod, and the box is provided with an internal threaded hole for the screw rod to pass through so that the screw rod is threadedly connected to the box through the internal threaded hole.

[0011] Furthermore, to facilitate the tightening of the limiting rod, one end of the screw is connected to a spring via a connecting plate, and the other end is connected to a tightening handle.

[0012] Furthermore, to facilitate standardizing the number of turns required for this limiting rod, the screw handle is a hook or a ring.

[0013] Furthermore, to prevent the spring from bending after being compressed, the box is also equipped with a spring grid plate to limit the movement path of the spring.

[0014] Furthermore, in order to better form a limiting structure for the spring, the spring grid includes multiple pairs of parallel and spaced partitions fixedly arranged inside the box, with a U-shaped groove for limiting the spring formed between each pair of partitions.

[0015] Furthermore, in order to facilitate the quick and stable placement of the syringe in the tool, the pressure plate includes an upper pressure plate located above the limiting groove and a lower pressure plate located above the spring grid plate. Both the upper and lower pressure plates are pulled out and mounted on the box, and sliding through holes are provided on both side walls of the box for the pressure plates to slide through.

[0016] The beneficial effects of this utility model are:

[0017] 1. This utility model provides a limiting groove in the box body, which facilitates the quick and easy placement of syringes neatly into the limiting groove, thereby limiting the syringe position.

[0018] 2. This utility model provides a sliding pressure plate above the limiting groove, which prevents multiple syringes from falling out of the box after the syringes are inserted.

[0019] 3. This utility model provides a limiting component on one side of the box body that faces the tail of the piston, in order to prevent the piston from moving outward during high-temperature sterilization and thus causing damage to the seal.

[0020] 4. This utility model incorporates a spring in the limiting assembly. The spring presses against the piston tail through the top plate. Since the top plate presses against the piston tail by applying a preload to the spring initially, it avoids the problem of the top plate not pressing against the piston tail due to errors in the height of the liquid. It also avoids the gap between the top plate and the piston tail that may occur after sterilization when the syringe may shrink.

[0021] 5. This utility model makes it easy to adjust the position of the limiting component by adjusting the limiting component as needed, and also makes it easy to place the syringes and then use the limiting component to hold the piston tail, which facilitates the syringe placement process and makes it easy to apply preload to the spring. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of this utility model.

[0024] In the diagram: 1. Box, 2. Upper pressure plate, 3. Syringe, 4. Spring, 5. Limiting rod, 6. Limiting plate, 7. Partition, 8. Lower pressure plate, 9. Nut, 10. Top plate, 11. Connecting plate. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figure 1 As shown in Embodiment 1 of this utility model, a pre-filled syringe sliding force testing auxiliary tool includes a box 1, a limiting groove disposed within the box 1 for placing syringes 3, and a pressure plate that opens and closes on the box 1. The box has multiple neatly arranged limiting grooves to facilitate the placement of multiple syringes 3. After placing the syringes 3 into the limiting grooves, the pressure plate is closed, making the placement of the syringes 3 more stable. A limiting component is provided on one side of the box 1, facing the tail of the syringe piston. This limiting component always presses against the piston to prevent displacement and damage to the syringe 3's seal. The limiting component includes a spring 4, whose length extends along the direction of the syringe and piston, allowing the spring to be compressed by the piston tail. Compressing the spring 4 applies a preload force to ensure the limiting component always presses against the piston tail, thus guaranteeing the syringe's seal. The preload force of the spring 4 should be close to, almost equal to, the initial sliding force of the syringe, to prevent the spring from pushing the piston forward when pressing against the piston tail, and also to prevent the limiting component from being pushed by the piston during heat sterilization.

[0027] Furthermore, such as Figure 1 As shown, the limiting component is adjustablely connected to the box 1, allowing the preload to be applied to the spring 4 after the syringe is placed in the box by adjusting the position of the limiting component. The spring is a conventional spring, and the relationship between the pressure exerted on the spring (i.e., the preload) and its compression is known, facilitating the determination of the applied preload by the spring's compression.

[0028] In addition, the box, pressure plate, and limiting components are all made of stainless steel.

[0029] Example 2 differs from Example 1 in that the limiting assembly further includes a limiting rod 5 adjustablely connected to the box 1. One end of the spring 4 is connected to the limiting rod 5, and the other end is connected to the top plate 10 to hold the piston tail. Holding the piston tail with the top plate facilitates even force distribution at the piston tail. By placing the spring between the limiting rod 5 and the top plate 10, the limiting rod 5 and the top plate 10 can compress the spring 4, thereby applying a preload to the spring.

[0030] In this embodiment, the limiting rod 5 is a screw rod. The box 1 has a through hole, and a nut 9 is provided in the through hole for the screw rod to pass through. The screw rod and the nut 9 are threadedly connected. By connecting the limiting rod 5 to the nut on the box through a thread, the adjustment of the limiting rod 5 is made simpler. Furthermore, a preload can be applied to the spring by turning the limiting rod 5.

[0031] In another embodiment, the limiting rod 5 is a screw, and the box 1 is provided with an internal threaded hole for the screw to pass through so that the screw is threadedly connected to the box 1 through the internal threaded hole.

[0032] Furthermore, such as Figure 1 As shown, one end of the screw is connected to the spring 4 via a connecting plate 11. Specifically, the spring 4 has a top plate 10 at its front end and a connecting plate 11 at its rear end. One end of the spring 4 is pressed against the piston tail via the top plate 10, and the other end is connected to a limiting rod via the connecting plate 11. Positioning the spring between the top plate 10 and the connecting plate 11 facilitates better spring compression. The end of the screw furthest from the spring is connected to a screw handle, allowing rotation of the limiting rod to adjust the position of the limiting assembly so that the top plate 10 at the front end of the spring presses against the piston tail. After this, further rotation of the limiting rod compresses the spring via the connecting plate at the rear end of the spring.

[0033] Furthermore, the top plate 10 is slightly curved towards the piston in the middle, so that the middle of the top plate 10 presses against the piston tail, reducing the contact area between the top plate 10 and the piston tail. The top plate 10 is also made of stainless steel, making it relatively smooth. This allows the spring to rotate with the screw when the handle is turned.

[0034] Example 3 differs from Example 2 in that the screw handle is a hook or a ring, facilitating the screwing of the limiting rod 5. In this example, a hook is preferred, as the opening direction of the hook makes it easy to determine that the hook has been screwed a full turn, thus facilitating the observation of the number of turns and ensuring consistency in the number of turns for each spring.

[0035] Example 4 differs from Example 2 in that, as Figure 1 As shown, the box 1 is also provided with a spring grid plate for limiting the movement path of the spring 4.

[0036] Furthermore, the spring grid includes multiple pairs of parallel and spaced partitions 7 fixedly arranged within the box, with the length direction of the partitions 7 aligned with the length direction of the syringe and piston. A U-shaped groove for a limiting spring 4 is formed between each pair of partitions 7.

[0037] Example 5 differs from Example 4 in that, as Figure 1 As shown, the box 1 is provided with multiple pairs of parallel and spaced fixed limiting plates 6, and each pair of limiting plates 6 forms a limiting groove for placing the syringe 3.

[0038] Example 6 differs from Example 5 in that, as Figure 1 As shown, the pressure plate includes an upper pressure plate 2 located above the limiting groove and a lower pressure plate 8 located above the spring grid plate. Both the upper pressure plate 2 and the lower pressure plate 8 are retractable onto the box 1, and both side walls of the box 1 are provided with sliding holes for the pressure plates to slide through. This allows the upper pressure plate 2 and the lower pressure plate 8 to pass through their respective sliding holes on one side of the box 1, slide, and then pass into their corresponding sliding holes on the other side of the box, thus preventing the syringe from falling out. There is a gap between the lower pressure plate 8 and the spring and the top plate 10, which does not hinder the movement or rotation of the spring and the top plate 10.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some or all of the technical features thereof, within the spirit and principles of the present invention, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An auxiliary tool for testing the sliding force of a pre-filled syringe, characterized in that, Includes a box (1), a limiting groove set inside the box (1) for placing a syringe (3) and a pressure plate set on the box (1) for opening and closing; a limiting component facing the tail of the syringe piston is provided on one side of the box (1) to prevent the piston from shifting and damaging the seal; and the limiting component includes a spring (4) that can be compressed by the tail of the piston so that the limiting component is always pressed against the tail of the piston.

2. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 1, characterized in that, The limiting component is adjustablely connected to the box (1).

3. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 2, characterized in that, The limiting assembly also includes a limiting rod (5) that is adjustablely connected to the box (1). One end of the spring (4) is connected to the limiting rod (5) and the other end is connected to the top plate (10) to hold the piston tail.

4. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 3, characterized in that, The limiting rod (5) is a screw rod. The box (1) has a through hole and a nut (9) for the screw rod to pass through. The screw rod and the nut (9) are threadedly connected.

5. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 3, characterized in that, The limiting rod (5) is a screw rod, and the box (1) is provided with an internal threaded hole for the screw rod to pass through so that the screw rod is threadedly connected to the box (1) through the internal threaded hole.

6. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 4 or 5, characterized in that, One end of the screw is connected to the spring (4) via a connecting plate (11), and the other end is connected to the screw handle.

7. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 6, characterized in that, The screw handle is a hook or a ring.

8. The auxiliary tool for testing the sliding force of a pre-filled syringe according to any one of claims 1 to 5 and 7, characterized in that, The box (1) is also provided with a spring grid for the movement path of the limiting spring (4).

9. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 8, characterized in that, The spring grid includes multiple pairs of parallel and spaced partitions (7) fixedly arranged in the box, with a U-shaped groove for a limiting spring (4) formed between each pair of partitions (7).

10. The auxiliary tool for testing the sliding force of a pre-filled syringe according to claim 8, characterized in that, The pressure plate includes an upper pressure plate (2) located above the limiting groove and a lower pressure plate (8) located above the spring grid plate. Both the upper pressure plate (2) and the lower pressure plate (8) are pulled out and installed on the box (1), and both sides of the box (1) are provided with sliding holes for the pressure plate to slide through.

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