SAFETY SYRINGE.

Abstract

The invention relates to a safety syringe comprising a barrel, a needle seat, and a plunger, wherein the needle seat has a hook shank, a coupling deformation portion, and a barrel clamping portion; and the plunger has a stem body and a hook insertion hole that can be sleeved with the hook shank of the needle seat and compresses the coupling deformation portion for elastic deformation so that the barrel clamping portion of the needle seat is not engaged in the barrel seat clamping groove, and the hook insertion hole can engage the hook shank of the needle seat to move the needle seat. The safety syringe allows for stable placement and rapid retraction of the needle seat and effectively reduces waste of liquid medicine.

Description

SAFETY SYRINGE FIELD OF INVENTION The invention relates to a medical device and in particular to a safety syringe. BACKGROUND OF THE INVENTION A conventional safety syringe, for example, in US Patent Publication US20060106339, still has problems of uncertainty in fixing and retraction of a needle seat, as well as a larger amount of liquid medicine residue. Therefore, the disadvantages of the known safety syringe still need to be improved. SUMMARY OF THE INVENTION In view of the above problems, a main object of the invention is to provide a safety syringe that can enable stable placement of a needle seat, facilitate rapid retraction of the needle seat, and effectively reduce liquid medicine waste. To achieve the above object, the invention provides a safety syringe comprising: a barrel having a barrel body, a housing chamber, a seat mounting hole and a seat fixing groove; a needle seat having a seat body mounted in the seat mounting hole of the barrel, a needle hole, a hook shank, a coupling deformation portion connected to the hook shank, and a barrel holding portion connected to the coupling deformation portion, thereby coupled and capable of being held in the seat holding groove of the barrel; and a plunger having a shank body, and a hook insertion hole that is capable of sheathing with the hook shank of the needle seat and compressing the coupling deformation portion to elastic deformation so that the cylinder clamping portion of the needle seat is not clamped in the cylinder seat clamping groove, wherein the needle hole hook insert is able to engage the hook shank of the needle seat to move the needle seat. The needle seat has a concave chamber that communicates with the needle hole and the mating deformation portion. The needle seat has a flow guide surface connected to the concave chamber. The needle seat has an internally recessed surface corresponding to the mating deformation portion. A vertical distance L1 from the center line of the needle seat to an outer edge of the hook shank is smaller than a vertical distance L2 from the center line of the needle seat to an outer edge of the coupling deformation portion. The cylinder clamping portion is connected to the coupling deformation portion by extending a certain length. The safety syringe also comprises a sealing ring R arranged between the barrel and the needle seat. The cylinder has a main cylinder and a front sleeve sleeved into the main cylinder. As a further improvement of the invention, toothed structures are provided on the corresponding end faces of the front sleeve and the master cylinder, and the toothed structure on the end face of the front sleeve meshes with the toothed structure on the end face of the master cylinder. Rotation between the front sleeve and the master cylinder can be prevented. The safety syringe further comprises a sealing ring R arranged between the front sleeve and the seat body of the needle seat. The cylinder has a flare, and the needle seat has a seat support that is placed together in the flare of the cylinder. By employing the above technical solutions, the safety syringe provided by the invention can indeed enable stable placement of the needle seat, facilitate rapid retraction of the needle seat, and effectively reduce liquid medicine waste. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a preferred embodiment of the invention; Figure 2 is a sectional view showing an operating state of a preferred embodiment of the invention; Figure 3 is a sectional view showing another operating state of a preferred embodiment of the invention; Figure 4 is a perspective view of a needle seat of a preferred embodiment of the invention; Figure 5 is a perspective view of another preferred embodiment of the invention; Figure 6 is a sectional view showing an operating state of another preferred embodiment of the invention; Figure 7 is a sectional view showing another operating state of another preferred embodiment of the invention; Figure 8 is a perspective view of a needle seat of another preferred embodiment of the invention; Figure 9 is a perspective view of yet another preferred embodiment of the invention; Figure 10 is a sectional view showing an operating state of yet another preferred embodiment of the invention; Figure 11 is a sectional view showing another operating state of yet another preferred embodiment of the invention; Figure 12 is a perspective view of a needle seat of yet another preferred embodiment of the invention; Figure 13 is a perspective view of an even more preferred embodiment of the invention; Figure 14 is a sectional view showing an operating state of an even more preferred embodiment of the invention; Figure 15 is a sectional view showing another operating state of an even more preferred embodiment of the invention; Figure 16 is a perspective view of a needle seat of an even more preferred embodiment of the invention; Figure 17 is a side view of a front sleeve of an even more preferred embodiment of the invention; Figure 18 is a front view of a front sleeve of an even more preferred embodiment of the invention; and Figure 19 is a side view of a master cylinder of an even more preferred embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION The following embodiments will be listed with reference to the accompanying drawings to describe the structure and effectiveness of the invention in detail. The application first illustrates here that all adjectives related to directionality, such as inside, outside, top and bottom, which are mentioned throughout the description are based on the indications in the drawings of the invention. The technical contents and features of the invention will be described in detail below by the listed embodiments together with the attached drawings. As shown in Figures 1 to 4, a safety syringe according to a preferred embodiment of the invention comprises the following components. In this embodiment, a main cylinder 10 can only form a cylinder 1; that is, in a broad sense, the safety syringe of the invention comprises a cylinder 1 having a main cylinder 10. The main cylinder 10 has a cylinder body 11, a housing chamber 12 communicated with a seat mounting hole 13, a seat holding groove 14 located at an inner edge of the seat mounting hole 13, and a widening 15 arranged between the housing chamber 12 and the seat holding groove 14. A needle seat 20 has a seat body 21 mounted in the seat mounting hole 13 of the main cylinder 10, a needle hole 22, a seat support 23 which is jointly positioned in the widening 15 of the cylinder 1, a hook rod 24 having a slightly tapered preferred rod body, a coupling deformation portion 25 in the form of an arc-shaped convex sheet and connected to the hook rod 24, and a cylinder holding portion 26 connected to the coupling deformation portion 25, thereby coupled to and capable of being held in the seat holding groove 14 of the cylinder 1. The needle seat 20 also has an internally retracted surface 211 that jointly corresponds with the coupling deformation portion 25; that is, a slightly recessed surface is formed at a position of the seat body 21 and / or the hook shank 24 that corresponds to the coupling deformation portion 25 to provide the coupling deformation portion 25 with more deformation space. The needle seat 20 also has a concave chamber 27 between the needle bore 22 and the coupling deformation portion 25. The needle seat 20 also has an annular groove 28 which may be fitted with a sealing ring R for sealing between the cylinder 1 and the needle seat 20. The needle seat 20 also has a flow guide surface 212 connected to the concave chamber 27, the flow guide surface 212 is also connected to the internally retracted surface 211, and the flow guide surface can allow the liquid medicine to flow more easily into the concave chamber 27. In addition, the other end of the cylinder holding portion 26 is also connected to the seat body 21 of the needle seat. In this embodiment, the needle seat 20 is equipped with a needle N in the needle hole 22 thereof. In this embodiment, a vertical distance L1 from a center line of the needle seat 20 to an outer edge of the hook shank 24 is smaller than a vertical distance L2 from the center line of the needle seat 20 to an outer edge of the coupling deformation portion 25. A plunger 3 has a push rod 30 with a rod body 31, and a sealing plug 40 connected to the rod body 31 of the push rod 30. The sealing plug 40 has a hook insertion hole 41 which can be sleeved with the hook rod 24 of the needle seat 20 and compress the coupling deformation portion 25 for elastic deformation so that the cylinder holding portion 26 of the needle seat 20 is not held in the seat holding groove 14 of the cylinder 1, and the hook insertion hole 41 can engage the hook rod 24 of the needle seat 20 to move the needle seat 20. The cylinder holding portion 26 of the needle seat 20 can be effectively engaged with the seat holding groove 14 of the cylinder 1. When the plunger 3 is pushed forward so that the hook insertion hole 41 of the sealing plug 40 thereof fits onto the hook rod 24 and the engaging deformation portion 25 of the needle seat 20, the barrel holding portion of the needle seat 20 can be controlled to disengage from the seat holding groove 14 of the barrel 1, thereby enabling successful retraction. When the engaging deformation portion 25 is elastically deformed, gaps between the engaging deformation portion and the seat body 21 as well as the hook rod 24 become small, thereby reducing the waste of liquid medicine therebetween. Finally, the needle seat 20 and the needle N are also inclined to one side due to the cooperative relationship between the coupling deformation portion 25 of the needle seat 20 and the hook insertion hole 41 of the plunger 3, thereby the needle seat 20 and the needle N are not easily ejected from the cylinder 1. This modality can thus achieve the object of the invention. The focus of the invention further lies in that the cooperative design between the coupling deformation portion 25 and the concave chamber 27 of the needle seat 20 can also effectively reduce the residual amount of the injected liquid medicine. As shown in Figures 5 to 8, the invention provides a safety syringe of another embodiment, which is substantially the same as the preceding embodiment, with the main difference below. The needle seat 20 also has a needle connecting portion 29 formed in the front section thereof. The needle N is arranged in a connecting member NI. The connecting member NI is further connected to the needle connection portion 29 of the needle seat 20. Similarly, this embodiment can thus achieve the object of the invention. As shown in Figures 9 to 12, a safety syringe according to another preferred embodiment of the invention is substantially the same as the preceding embodiment, with the main difference below. The cylinder 1 has a main cylinder 10 and a front sleeve 50 that can be tightly sheathed in the main cylinder 10 to together form a seat mounting hole 13, and the sealing ring R is disposed between the front sleeve 50 and the seat body 21 of the needle seat 20. That is, the main cylinder 10 also has a front sleeve 50 sleeved at the front end of the main cylinder 10. In this embodiment, the seat-holding groove 14 and the enlargement 15 are formed in the main cylinder 10, and of course, they can also be formed in place in the front sleeve 50. The use of a combination of two members can make the cylinder 1 easier to manufacture and can increase its usability. Similarly, this embodiment can thus achieve the object of the invention. As shown in Figures 13 to 19, a safety syringe according to another preferred embodiment of the invention is substantially the same as the preceding embodiment, with the main difference being as follows. The needle seat 20 has a larger size and an outer cylinder portion is additionally formed to be equipped with the needle N. The cylinder holding portion 26 may be extended to a certain length and then connected to the coupling deformation portion 25. Accordingly, the hook insertion hole 41 of the sealing plug 40 may still compress the coupling deformation portion 25 of the needle seat 20 for elastic deformation to drive the engagement and disengagement of the cylinder holding portion 26. Similarly, this embodiment can thus achieve the object of the invention. The push rod 30 and sealing plug 40 of the invention may be combined or integral. In addition to being a separate member as described above, the sealing ring R of the invention may also be integrally formed in the cylinder 1 or the needle seat. When assembling the safety syringe of this embodiment, the front sleeve 50 is first mounted on a front end of the main barrel 10, the needle seat 20 is disposed at the front end of the main barrel 10 from a rear end of the main barrel 10, the coupling deformation portion 25 of the needle seat 20 is fastened in the seat fastening groove 14 of the main barrel 10, the connection member NI is then mounted on a front end of the needle seat 20, the needle N is then mounted on the connection member Ni, and the connection member NI is screwed to the needle seat 20 during assembly. Since the front sleeve 50 is sleeved with the main barrel 10, relative rotation may occur therebetween such that the connection member NI cannot be tightly closed in the needle seat 20.To solve this problem, toothed structures cooperating with each other are provided on corresponding end faces of the front sleeve 50 and the main cylinder 10, and the toothed structure on the end face of the front sleeve 50 meshes with the toothed structure on the end face of the main cylinder 10. In this way, when the connecting member NI is rotatably mounted, the front sleeve 50 and the main cylinder 10 do not rotate so that the connecting member NI can be tightly closed in the needle seat 20 and then the needle N can be tightly closed. Any of the embodiments described above may be used alone or in combination with each other to achieve the object of the invention. In summary, the safety syringe provided by the invention can certainly allow stable placement of a needle seat, facilitate rapid retraction of the needle seat and effectively reduce the waste of liquid medicine, thereby achieving the object of the invention. The above embodiments are intended solely to describe the technical concept and features of the invention, and are intended to enable persons skilled in the art to understand and implement the contents of the invention. Therefore, they do not limit the scope of protection of the invention. Any equivalent changes or modifications made based on the spirit and essence of the invention shall be covered within the scope of protection of the invention.

Claims

1. A safety syringe, characterized in that it comprises: a barrel having a barrel body, a receiving chamber, a seat mounting hole and a seat holding groove; a needle seat having a seat body mounted in the seat mounting hole of the barrel, a needle hole, a hook shank, a coupling deformation portion connected to the hook shank, and a barrel holding portion connected to the coupling deformation portion, coupled thereto and capable of being held in the seat holding groove of the barrel;and a plunger having a rod body, and a hook insertion hole that is capable of sheathing with the hook rod of the needle seat and compressing the coupling deformation portion for elastic deformation so that the cylinder holding portion of the needle seat is not held in the cylinder seat holding groove, the hook insertion hole can engage the hook rod of the needle seat to move the needle seat.; 2. The safety syringe according to claim 1, characterized in that the needle seat has a concave chamber communicating with the needle hole and the coupling deformation portion.

3. The safety syringe according to claim 2, characterized in that the needle seat has a flow guide surface connected to the concave chamber.

4. The safety syringe according to claim 1, characterized in that the needle seat has an internally retracted surface corresponding to the coupling deformation portion.

5. The safety syringe according to claim 1, characterized in that a vertical distance (L1) from a center line of the needle seat to an outer edge of the hook shank is smaller than a vertical distance (L2) from the center line of the needle seat to an outer edge of the coupling deformation portion.

6. The safety syringe according to claim 1, characterized in that the cylinder holding portion is connected with the coupling deformation portion by extending a certain length.

7. The safety syringe according to claim 1, further characterized in that it comprises a sealing ring R arranged between the barrel and the needle seat.

8. The safety syringe according to claim 1, characterized in that the cylinder has a main cylinder and a front sleeve sheathed on the main cylinder.

9. The safety syringe according to claim 8, characterized in that toothed structures are provided on corresponding end faces of the front sleeve and the main barrel, and the toothed structure on the end face of the front sleeve meshes with the toothed structure of the end face of the main barrel.

10. The safety syringe according to claim 8, further characterized in that it comprises a sealing ring R arranged between the front sleeve and the seat body of the needle seat.

11. The safety syringe according to claim 1, characterized in that the barrel has a widening, and the needle seat has a seat support that is placed together in the widening of the barrel.

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