Injection-assisting device and needle-hiding structure thereof

Abstract

A needle-hiding structure provided by the present invention comprises an inner sheath, a rotary sleeve and a return spring, wherein the movement of the inner sheath is restricted by a guide structure, and the rotary sleeve and the inner sheath are linked by means of a linkage structure, so as to enable the inner sheath to act along with the rotary sleeve. The return spring is mounted on the inner sheath, and applies an elastic force in a normal state to allow the inner sheath to be in a first position. During injection, the inner sheath retracts from the first position to a second position, and compresses the return spring; and after injection, the return spring pushes the inner sheath to move to a third position. The needle-hiding structure is loaded in an internal space formed by a front barrel and a rear barrel connected to each other in a sleeving manner, so as to form an injection-assisting device.

Description

Injection aid device and its needle concealment structure Technical Field

[0001] This invention relates to the field of medical injection technology, and more specifically, to an injection aid device and its needle concealment structure. Background Technology

[0002] In the fields of medical devices, biomedicine, and drug delivery systems, drug delivery devices have become an indispensable part. These devices help patients use medications more conveniently and accurately. Among them, pre-filled syringes are a common type of drug delivery device. They are pre-loaded with medication, and the injection can be completed with a simple operation.

[0003] However, for some special medications, the viscosity and flow characteristics can make using traditional pre-filled syringes difficult. Furthermore, since pre-filled syringes typically consist of a pre-filled injection container and a needle connected to the container, the needle is often exposed after injection, increasing patient discomfort and posing safety risks. Therefore, some solutions incorporate auxiliary devices to avoid or reduce these risks.

[0004] Existing technologies offer several solutions that attempt to address the aforementioned problems. For example, the automatic retraction auxiliary device in US patent 11850410 conceals the needle by controlling the extension and retraction of a pre-filled syringe. Similarly, the manual injection device in CN 115715831 employs a spring-loaded internal syringe for needle concealment. After the injection is completed, releasing the injection plunger causes the internal syringe to spring back into the auxiliary device, thus concealing the needle.

[0005] However, these existing technologies still have some problems in this field. First, although some devices can hide the needle after injection, they are prone to misoperation during operation, which can cause harm to the patient. That is, with existing injection devices, the operator cannot release the finger pressing the device when the injection is about to be completed. The finger must be released only after the needle of the injection device is withdrawn from the body so that the internal structure of the injection device can rebound smoothly and thus achieve the function of hiding the needle.

[0006] Secondly, in some existing technologies, the plunger can be pulled outward after injection, which could lead to operator error and medical risks. Finally, the hidden needle mechanism in some devices is quite complex, which not only increases manufacturing costs but also affects the reliability and ease of use of the device. Summary of the Invention

[0007] In order to overcome the shortcomings of the prior art, the main objective of the present invention is to provide an injection assistance device and its needle hiding structure, which can provide a simplified actuation mechanism to reduce errors and inconveniences in operation.

[0008] To achieve the above objectives, the needle concealment structure provided by the present invention includes an inner sheath, a rotating sleeve, and a return spring. The inner sheath is restricted by a guide structure and moves along a first axial direction. A linkage structure exists between the rotating sleeve and the inner sheath, allowing the inner sheath to move with the rotating sleeve via the linkage structure. The return spring is disposed on the inner sheath, so that the inner sheath is normally subjected to the elastic force provided by the return spring and is positioned in a first position. During injection, the inner sheath retracts from the first position along the first axial direction to a second position, compressing the return spring. After injection, the return spring pushes the inner sheath to move along the first axial direction to a third position.

[0009] In one embodiment, the linkage structure has a first slide groove, a second slide groove, and a first slider. The first slide groove and the second slide groove are disposed on the rotating sleeve. One end of the second slide groove is connected to the first slide groove, and the first slider is disposed on the inner sleeve and can slide in the second slide groove and / or the first slide groove to realize the linkage between the inner sleeve and the rotating sleeve. The first slide groove extends along the first axial direction, and a first end and a second end are respectively provided at both ends of the first slide groove.

[0010] In one embodiment, the second end extends at a first angle relative to the first axis, the first angle being between 5 degrees and 45 degrees.

[0011] In one embodiment, the end of the second slide groove connected to the first slide groove is inclined at a second angle, which is between 5 degrees and 45 degrees.

[0012] In one embodiment, the linkage structure has two first sliders and a third slide groove. The third slide groove is circumferentially disposed on the inner wall surface of the rotating sleeve, and the third slide groove is periodically bent along the radial direction of the rotating sleeve. The first sliders are respectively symmetrically protruding on the outer wall surface of the extension pen barrel and can slide in the third slide groove. By being in different positions in the third slide groove, the linkage and locking between the extension pen barrel and the rotating sleeve can be realized.

[0013] In one embodiment, the injection assist device further includes a propulsion assembly having a pressing cap and two guide rods, one end of each guide rod being disposed on a side edge of the pressing cap, and the other end extending along a first axial direction. This application also provides an injection assist device comprising:

[0014] One rear tube;

[0015] A front cylinder and a rear cylinder, their opposite ends being nested together, thereby communicating a first internal space of the front cylinder and a second internal space of the rear cylinder; and

[0016] The hidden structure of the needle includes:

[0017] An inner sheath is movably disposed in the first internal space of the front cylinder, and there is a guide structure between the inner sheath and the front cylinder, so that the inner sheath moves along the first axis under the restriction of the guide structure.

[0018] A rotating sleeve is movably disposed between the inner sheath and the front cylinder, and a linkage structure exists between the inner sheath and the rotating sleeve, allowing the inner sheath to move along with the rotating sleeve via the linkage structure; and

[0019] A return spring is provided between the inner sleeve and the front cylinder, so that the inner sleeve is normally subjected to the elastic force provided by the return spring and the inner sleeve is in a first position, while a part of the inner sleeve is exposed outside the front cylinder.

[0020] During injection, the inner sheath retracts from the first position along the first axis to a second position flush with the front cylinder, and the return spring is compressed.

[0021] After injection, the reset spring pushes the inner sheath to move along the first axis to a third position.

[0022] In one embodiment, the linkage structure has a first slide groove, a second slide groove, and a first slider. The first slide groove and the second slide groove are disposed on the rotating sleeve. One end of the second slide groove is connected to the first slide groove, and the first slider is disposed on the inner sleeve and can slide in the second slide groove and / or the first slide groove to realize the linkage between the inner sleeve and the rotating sleeve. The first slide groove extends along the first axial direction, and a first end and a second end are respectively provided at both ends of the first slide groove.

[0023] In one embodiment, the second end extends at a first angle relative to the first axis, the first angle being between 5 degrees and 45 degrees.

[0024] In one embodiment, the end of the second slide groove connected to the first slide groove is inclined at a second angle, which is between 5 degrees and 45 degrees.

[0025] In one embodiment, the linkage structure has two first sliders and a third slide groove. The third slide groove is circumferentially disposed on the inner wall surface of the rotating sleeve, and the third slide groove is periodically bent along the radial direction of the rotating sleeve. The first sliders are respectively symmetrically protruding on the outer wall surface of the extension pen barrel and can slide in the third slide groove. By being in different positions in the third slide groove, the linkage and locking between the extension pen barrel and the rotating sleeve can be realized.

[0026] In one embodiment, the injection aid further includes a propulsion assembly having a pressing cap and two guide rods, one end of each guide rod being disposed on the side edge of the pressing cap, and the other end extending along a first axial direction.

[0027] In one embodiment, a snap-fit ​​structure is provided between the guide rod and the rear cylinder, which can lock the guide rod in a predetermined position.

[0028] In one embodiment, the snap-fit ​​structure has a protrusion and a plurality of grooves. The protrusion is disposed on the guide rod, and each groove is disposed on the rear cylinder for the protrusion to be inserted into.

[0029] In one embodiment, an elongated rib is provided on the outer wall surface of the inner sheath, and a guide groove is provided on the front cylinder for the rib to be inserted.

[0030] Accordingly, the present invention has at least the following characteristics:

[0031] 1. It provides a simplified actuation mechanism, reducing operational errors and inconvenience.

[0032] 2. The rotation unlocking method has a simpler structure and mechanism, which reduces manufacturing costs and increases operational reliability.

[0033] The specific techniques employed in this invention will be further explained through the following embodiments and accompanying drawings. Attached Figure Description

[0034] Figure 1 is a three-dimensional assembly diagram of the first embodiment of the present invention.

[0035] Figure 2 is a three-dimensional exploded view of the first embodiment of the present invention.

[0036] Figure 3 is a cross-sectional view related to Figure 1.

[0037] Figure 4 is a three-dimensional assembly diagram of the second embodiment of the present invention.

[0038] Figure 5 is a three-dimensional exploded view of the second embodiment of the present invention.

[0039] Figure 6 is a cross-sectional view related to Figure 4.

[0040] Figure 7 is a schematic diagram related to Figure 6.

[0041] Figure 8 is a diagram of the operation following Figure 6.

[0042] Figure 9 is a schematic diagram related to Figure 8.

[0043] Figure 10 is a diagram of the operation following Figure 9.

[0044] Figure 11 is a schematic diagram related to Figure 10.

[0045] Figure 12 is a diagram of the operation following Figure 11.

[0046] Figure 13 is a schematic diagram of the rotating sleeve according to the third embodiment of the present invention.

[0047] Figure 14 is a cross-sectional view related to Figure 13.

[0048] Figure 15 is a schematic diagram of the inner sheath in the third embodiment of the present invention.

[0049] In the diagram: 100A: Front cylinder; 101A: First internal space; 110A: Rear cylinder; 111A: Second internal space; 130, 130A: Propulsion assembly; 131, 131A: Press cap; 133, 133A: Guide rod; 134A: Snap-fit ​​structure; 1341A: Protrusion; 1342A: Groove; 150, 150A: Inner sleeve; 151, 151A: Guide structure; 1511A: Guide groove; 1512A: Protruding rib; 160, 160A, 160B: Rotating sleeve; 1 61, 161A, 161B: Linkage structure; 1611, 1611A: First slide groove; 1612, 1612A: Second slide groove; 1613, 1613A: First slider; 1614, 1614A: First end; 1615, 1615A: Second end; 1616B: Third slide groove; 16161B: First high point; 16162B: First low point; 16163B: Second high point; 1616B: Second low point; 170, 170A: Return spring; 180A: Protective cap. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0051] In this document, the terms "a" or "an" are used to describe the components and elements described herein. This is used merely for ease of explanation and to provide a general meaning regarding the scope of the invention. Therefore, unless it is obvious otherwise, this description should be understood to include one or at least one, and the singular also includes multiples.

[0052] In this document, the terms "comprising," "having," or any other similar terms are intended to cover non-exclusive inclusions. For example, a component or structure containing multiple elements is not limited to those listed herein, but may include other elements not expressly listed but which are generally inherent to the component or structure.

[0053] First, please refer to Figures 1 to 3, which show the needle concealment structure provided in the first embodiment of the present invention. The structure includes a propulsion assembly 130, an inner sheath 150, a rotating sleeve 160, and a return spring 170. The inner sheath 150 is restricted by a guide structure 151 and moves along a first axial direction. A linkage structure 161 exists between the rotating sleeve 160 and the inner sheath 150, causing the inner sheath 150 to move along with the rotating sleeve 160 via the linkage structure 161. The return spring 170 is disposed on the inner sheath 150, so that the inner sheath 150 is normally subjected to the elastic force provided by the return spring 170, and the inner sheath 150 is normally positioned in a first position.

[0054] Furthermore, the linkage structure 161 has a first slide groove 1611, a second slide groove 1612, and a first slider 1613. The first slide groove 1611 and the second slide groove 1611 are disposed on the rotating sleeve 160. One end of the second slide groove 1612 is connected to the first slide groove 1611, and the first slider 1613 is disposed on the inner sleeve 150 and can slide on the second slide groove 1612 and / or the first slide groove 1611 to realize the linkage between the inner sleeve 150 and the rotating sleeve 160. The first slide groove 1611 extends along a first axial direction, and its two ends are respectively provided with a first end 1614 and a second end 1615. The second end 1615 extends at a first angle relative to the first axial direction, the first angle being between 5 degrees and 45 degrees. The end of the second slide groove 1612 connected to the first slide groove 1611 is inclined at a second angle, the second angle being between 5 degrees and 45 degrees. The propulsion assembly 130 has a pressing cap 131 and two guide rods 133. One end of each guide rod 133 is located on the side edge of the pressing cap 131, while the other end extends along the first axial direction.

[0055] Please refer to Figures 4 to 12, which show the injection assistance device provided in the second embodiment of the present invention. It includes a front cylinder 100A, a rear cylinder 110A, and a linkage structure. The linkage structure includes a propulsion component 130A, an inner sheath 150A, a rotating sleeve 160A, and a return spring 170A.

[0056] The front cylinder 100A and the rear cylinder 110A are nested together at their opposite ends, and a first internal space 101A of the front cylinder 100A and a second internal space 111A of the rear cylinder 110A are interconnected. In other possible embodiments, the front cylinder 100A and the rear cylinder 110A may also be an integral structure and may be used to store an external medicine container (not shown).

[0057] The propulsion assembly 130A has a pressing cap 131A and two guide rods 133A. One end of each guide rod 133A is located on the side edge of the pressing cap 131A, while the other end extends along the first axial direction, so that the guide rods 133A can abut against the inner wall surface of the rear cylinder 110A.

[0058] Furthermore, a snap-fit ​​structure 134A is provided between the guide rod 133A and the rear cylinder 110A, which can lock the guide rod 133A in a predetermined position. More specifically, the snap-fit ​​structure 134A has a mutually complementary concave-convex design. In this example, a protrusion 1341A is provided on each of the guide rods 133A, and the rear cylinder 110A has multiple grooves 1342A for the protrusions 1341A to be inserted, achieving a positioning function.

[0059] For example, there are two grooves 1342A, located at the front and rear ends of the rear cylinder 110A respectively. The front groove 1342A can temporarily fix the protrusion 1341A, positioning the guide rod 133A in the initial position; while the rear groove 1342A fixes the protrusion 1341A after the injection process is completed, preventing unnecessary displacement of the guide rod 133A, thereby ensuring safety and accuracy.

[0060] In addition, a detachable protective cap 180A is attached to the front cylinder 110A, as shown in Figures 4 and 6.

[0061] The inner sheath 150A is movably disposed in the first internal space 101A of the front cylinder 100A, and a guide structure 151A is provided between the inner sheath 150A and the front cylinder 100A, so that the inner sheath 150A is restricted by the guide structure 151A and moves along the first axial direction. The guide structure 151A has a mutually complementary concave-convex structure. In this example, at least one elongated rib 1512A is provided on the outer wall surface of the inner sheath 150A, and the front cylinder 100 is provided with at least one guide groove 1511A for the rib 1512A to be inserted to achieve the guiding function.

[0062] For example, there are two ribs 1512A and two guide grooves 1511A. These ribs 1512A and guide grooves 1511A are symmetrically arranged between the inner sheath 150A and the front cylinder 100A to ensure that the inner sheath 150A can be stably guided during the sliding process, avoid unnecessary displacement, and ensure the precise operation of the injection auxiliary device.

[0063] A rotating sleeve 160A is movably disposed between the inner sleeve 150A and the front cylinder 100A, and a linkage structure 161A is provided between the inner sleeve 150A and the rotating sleeve 160A, so that the inner sleeve 150A moves with the rotating sleeve 160A through the linkage structure 161A; wherein, the linkage structure 161A has a first sliding groove 1611A, a second sliding groove 1612A and a first slider 1613A. The first sliding groove 1611A and the second sliding groove 1612A are disposed on the rotating sleeve 160A. The end of the second sliding groove 1612A near the front cylinder 100A is connected to the first sliding groove 1611A, and the first slider 1613A is disposed on the inner sleeve 150A and can slide in the second sliding groove 1612A and / or the first sliding groove 1611A to realize the linkage between the inner sleeve 150A and the rotating sleeve 160A.

[0064] Furthermore, the first slide groove 1611A extends primarily along the first axial direction. The two ends of the first slide groove 1611A are respectively provided with a first end 1614A near the front cylinder 100A and a second end 1615A away from the front cylinder 100A. The second end 1615A extends at a first angle relative to the first axial direction. The end of the second slide groove 1612A connected to the first slide groove 1611A is also inclined at a second angle, while the other end of the second slide groove 1612A extends along the first axial direction. The first angle and the second angle are between 5 degrees and 45 degrees.

[0065] A return spring 170A is disposed between the inner sleeve 150A and the front cylinder 100A, so that the inner sleeve 150A is normally subjected to the elastic force provided by the return spring 170A. The first slider 1613A is preset within the second slide groove 1612A, and the inner sleeve 150A, under the elastic force of the return spring 170A, is locked against the groove wall at the other end of the second slide groove 1612A away from the front cylinder 100A, thus entering a first locked state. This positions the inner sleeve 150A in a first position, with a portion of the inner sleeve 150A exposed outside the front cylinder 100A, as shown in Figures 6 and 7.

[0066] Based on the above structural description, the specific usage steps of this invention are as follows:

[0067] First, as shown in Figure 6, the components of the injection aid are in their initial positions.

[0068] Next, during injection, the protective cap 180A is removed, and the injection auxiliary device is placed against an external human body. The inner sheath 150A is pushed by the external human body and retracts from the first position along the first axis to the second position flush with the front cylinder 100A, thereby compressing the return spring 170A. At the same time, the first slider 1613A is pushed from the second slide groove 1612A into the first slide groove 1611A, thereby releasing the first locking state, as shown in Figures 8 and 9.

[0069] Next, press the cap 131A to begin the injection procedure. Simultaneously, the protrusion 1341A on the guide rod 133A engages with another groove 1342A and is locked in place, as shown in Figure 8. This ensures that the device cannot be pulled out after injection, thereby avoiding medical risks associated with operator error, reducing manufacturing costs, and improving device reliability and ease of use.

[0070] After the injection is completed, the device is removed from the external body. At this time, the inner sheath 150A is also away from the external body, so that the return spring 170A can push the inner sheath 150A to move along the first axis to the third position that completely covers the needle 140. At the same time, the first slider 1613A moves in the first groove 1611A toward the second end, as shown in Figures 10 and 11.

[0071] Finally, when it is desired to lock the inner sheath 150A, the rotating sleeve 160A is rotated so that the first slider 1613A enters the second end 1615A and is locked, thereby putting the inner sheath 150A in a second locked state, as shown in Figure 12.

[0072] Accordingly, the present invention can achieve the following effects:

[0073] 1. It provides a simplified actuation mechanism, reducing operational errors and inconvenience.

[0074] 2. The rotation unlocking method has a simpler structure and mechanism, which reduces manufacturing costs and increases operational reliability.

[0075] As shown in Figures 13 to 15, this is a third embodiment of the drug injection auxiliary device of the present invention. The difference between this embodiment and the second embodiment lies in the linkage structure 161B. Specifically, the linkage structure 161B has two first sliders 1613B and a third slide groove 1616B. The third slide groove 1616B is arranged around the inner wall surface of the rotating sleeve 160B, and the third slide groove 1616B is periodically curved along the radial direction of the rotating sleeve 160B. That is, in this example, with the radial direction of the rotating sleeve 160B as the reference, there is a first high point 16161B, a first low point 16162B, a second high point 16163B, and a second low point 16164B at different positions, and this cycle repeats continuously. The first slider 1613B is symmetrically protruding on the outer wall of the inner sleeve 150B and can slide in the third slide groove 1616B. By using different high and low points, the linkage and locking between the inner sleeve 150B and the rotating sleeve 160B can be realized, ensuring that the device can be stably fixed or flexibly adjusted during use.

[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A needle concealment structure, characterized in that, The needle concealment structure includes: An inner sheath, which is restricted by a guide structure to move along a first axis; A rotating sleeve has a linkage structure with the inner sheath, so that the inner sheath moves with the rotating sleeve through the linkage structure. as well as A return spring is provided on the inner sleeve, so that the inner sleeve is normally subjected to the elastic force provided by the return spring and the inner sleeve is positioned in a first position.

2. The needle concealment structure according to claim 1, characterized in that, The linkage structure has a first slide groove, a second slide groove, and a first slider. The first slide groove and the second slide groove are disposed on the rotating sleeve. One end of the second slide groove is connected to the first slide groove, and the first slider is disposed on the inner sleeve and can slide in the second slide groove and / or the first slide groove to realize the linkage between the inner sleeve and the rotating sleeve. The first slide groove extends along the first axial direction, and the two ends of the first slide groove are respectively provided with a first end and a second end.

3. The needle concealment structure according to claim 2, characterized in that, The second end extends at a first angle relative to the first axis, the first angle being between 5 degrees and 45 degrees.

4. The needle concealment structure according to claim 3, characterized in that, The end of the second slide groove connected to the first slide groove is inclined at a second angle, which is between 5 degrees and 45 degrees.

5. The needle concealment structure according to claim 1, characterized in that, The linkage structure has two first sliders and a third slide groove. The third slide groove is arranged around the inner wall of the rotating sleeve and is periodically bent along the radial direction of the rotating sleeve. The first sliders are respectively symmetrically protruding from the outer wall of the inner sleeve and can slide in the third slide groove. By being in different positions in the third slide groove, the linkage and locking between the inner sleeve and the rotating sleeve can be realized.

6. The needle concealment structure according to claim 1, characterized in that, It also includes a propulsion assembly, which has a pressing cap and two guide rods. One end of each of the two guide rods is located on the side edge of the pressing cap, and the other end extends along a first axial direction.

7. An injection aid device, characterized in that, The injection assistance device includes: One rear tube; A front cylinder is sleeved with the opposite ends of the rear cylinder, and a first internal space of the front cylinder is connected to a second internal space of the rear cylinder. as well as The hidden structure of the needle includes: An inner sleeve is movably disposed in the first internal space of the front cylinder, and a guide structure is provided between the inner sleeve and the front cylinder, so that the inner sleeve moves along the first axis under the restriction of the guide structure. A rotating sleeve is movably disposed between the inner sheath and the front cylinder, and the inner sheath and the rotating sleeve have a linkage structure, so that the inner sheath moves with the rotating sleeve through the linkage structure; and A return spring is provided between the inner sleeve and the front cylinder, such that the inner sleeve is normally subjected to the elastic force provided by the return spring and the inner sleeve is positioned in a first position, while a portion of the inner sleeve is exposed outside the front cylinder. During injection, the inner sheath retracts from the first position along the first axis to a second position flush with the front cylinder, and the return spring is compressed; After injection, the reset spring pushes the inner sheath to move along the first axis to a third position.

8. The injection aid device according to claim 7, characterized in that, The linkage structure has a first slide groove, a second slide groove, and a first slider. The first slide groove and the second slide groove are disposed on the rotating sleeve. One end of the second slide groove is connected to the first slide groove, and the first slider is disposed on the inner sleeve and can slide in the second slide groove and / or the first slide groove to realize the linkage between the inner sleeve and the rotating sleeve. The first slide groove extends along the first axial direction, and the two ends of the first slide groove are respectively provided with a first end and a second end.

9. The injection aid device according to claim 8, characterized in that, The second end extends at a first angle relative to the first axis, the first angle being between 5 degrees and 45 degrees.

10. The injection aid device according to claim 9, characterized in that, The end of the second slide groove connected to the first slide groove is inclined at a second angle, which is between 5 degrees and 45 degrees.

11. The injection aid device according to claim 7, characterized in that, The linkage structure has two first sliders and a third slide groove. The third slide groove is arranged around the inner wall of the rotating sleeve and is periodically bent along the radial direction of the rotating sleeve. The first sliders are respectively symmetrically protruding from the outer wall of the inner sleeve and can slide in the third slide groove. By being in different positions in the third slide groove, the linkage and locking between the inner sleeve and the rotating sleeve can be realized.

12. The injection aid device according to claim 7, characterized in that, It also includes a propulsion assembly, which has a pressing cap and two guide rods. One end of each of the two guide rods is located on the side edge of the pressing cap, and the other end extends along a first axial direction.

13. The injection aid device according to claim 12, characterized in that, The two guide rods are also provided with a snap-fit ​​structure between them and the rear cylinder, which can lock the two guide rods in a predetermined position.

14. The injection aid device according to claim 13, characterized in that, The buckle structure has a protrusion and multiple grooves. The protrusion is disposed on the two guide rods, and each of the grooves is disposed on the rear cylinder for the protrusion to be inserted into.

15. The injection aid device according to claim 7, characterized in that, The inner sheath has an elongated rib on its outer wall surface, and the front cylinder has a guide groove for the rib to be inserted.

Images