Syringe assembly

Abstract

To provide a syringe assembly which reduces a dead space where liquid chemical remains and is easy to assemble.SOLUTION: A syringe assembly includes: a syringe 105 which has an almost cylindrical or an almost cone-shaped fitting part 113 formed at a front end and a liquid chemical passage hole 123 having an almost circular cross-sectional shape extending in a back and forth direction provided for the fitting part; and a needle hub 103 having a recess 111 fitted to the fitting part 113 formed at a rear end and a needle hole 137 to which a needle 109 provided on a front side of the recess 111 is fitted. When the fitting part and the recess fit, a front surface 121 of the fitting part and a bottom surface 119 of the recess contact, a central axis of the needle and a central axis of the liquid chemical passage hole 123 almost match, and an internal diameter of the liquid chemical passage hole is equal to or larger than the internal diameter of the needle and smaller than an outer diameter of the needle.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a syringe assembly comprising a needle hub and a syringe.

Background Art

[0002] Conventionally, needle hubs and syringes have been manufactured in accordance with standards. By doing so, there are merits such as improving the compatibility of products and enabling injection in the same manner with any syringe assembly. However, conventional syringes manufactured according to existing standards have a large dead space where the chemical solution remains. Eliminating the dead space of the syringe to reduce the loss of expensive chemical solutions has great merits.

[0003] To eliminate this dead space, for example, Patent Document 1 discloses filling the space between the injection needle and the syringe with a filler. Further, Patent Document 2 discloses that the needle tube of the injection needle is composed of a tip side and a base end side, and when the injection needle is connected to the syringe, the tip end portion of the base end side of the needle tube can be inserted into the tip end portion of the syringe.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the syringe of Patent Document 1 increased the number of parts of the syringe assembly and was not easy to assemble. Further, the syringe of Patent Document 2 made it difficult to pierce the needle into the syringe and the assembly of the syringe assembly was not easy.

[0006] Therefore, an object of the present invention is to provide a syringe assembly that reduces the dead space where the chemical solution remains and is easy to assemble.

Means for Solving the Problems

[0007] The syringe assembly of the present invention includes a syringe having a fitting portion formed at the front end and having a substantially cylindrical or substantially frustoconical shape, and a chemical solution passage hole provided in the fitting portion and having a substantially circular cross-sectional shape extending in the front-rear direction; a needle hub having a recess formed at the rear end and fitting with the fitting portion, and a needle hole provided with a needle in front of the recess; when the fitting portion and the recess are fitted, the front surface of the fitting portion and the bottom surface of the recess are in contact, and the central axis of the needle and the central axis of the chemical solution passage hole are substantially coincident; the inner diameter of the chemical solution passage hole is equal to or larger than the inner diameter of the needle and smaller than the outer diameter of the needle, and it is a needle syringe assembly.

Effects of the Invention

[0008] According to the present invention, a syringe assembly is provided that reduces the dead space where the chemical solution remains and is easy to assemble.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] Hereinafter, various embodiments for carrying out the present invention will be described with reference to the drawings. The syringe assemblies described below are for embodying the technical idea of the present disclosure, and unless otherwise specifically described, the present disclosure is not limited to the following. For ease of explanation or understanding of the key points, the same reference numerals are shown for convenience in FIGS. 1 to 3 and FIGS. 4 to 6. In particular, the same effects due to the same configuration will not be sequentially mentioned for each embodiment or example. The sizes and positional relationships of the members shown in each drawing may be exaggerated for clarity of explanation.

[0011] (First Syringe Assembly) FIG. 1 is (a) a schematic view and (b) a schematic cross-sectional view taken along line A-A of FIG. 1(a) of a syringe assembly according to one embodiment of the present invention. FIG. 2 is an enlarged view of the needle hub at B in FIG. 1(b) and the tip of the syringe according to one embodiment of the present invention. FIG. 3 is an enlarged view of the portion where the needle hub and the syringe are fitted according to one embodiment of the present invention, and is a diagram for explaining the inner diameter of the needle, the outer diameter of the needle, the diameter of the needle hole, the diameter of the needle pressing portion of the needle hole, and the diameter of the chemical solution passage hole. The syringe assembly of the present invention will be described with reference to FIGS. 1 to 3.

[0012] In this specification, the needle side of the syringe, that is, the side from which the drug solution comes out, is defined as the front side, and the side where the plunger is inserted and the drug solution is replenished is defined as the rear side and described. As shown in FIGS. 1(a) and (b), the first syringe assembly 101 of the present invention includes a needle 109, a needle hub 103 fitted to the front end of a syringe 105, a syringe 105 having a drug solution storage space 117, and a plunger 107 for pushing the drug solution out from the rear side 115 of the syringe.

[0013] As shown in FIG. 2, the syringe 105 includes a fitting portion 113 having a substantially cylindrical or substantially frustoconical shape at the front end. The fitting portion 113 is a portion that fits with a concave portion 111 of the needle hub 103 described later. The fitting portion 113 may be cylindrical or polygonal cylindrical as long as it has a shape that matches the concave portion 111. Further, the fitting portion 113 may be frustoconical or polygonal frustoconical. If the fitting portion 113 is frustoconical and tapers toward the front end, it is preferable because it is easy to fit and remove the needle hub 103. In particular, if the fitting portion 113 is frustoconical, it is preferable because there is no directionality when fitting and it can be fixed from any direction.

[0014] The fitting portion 113 is provided with a drug solution passage hole 123 having a substantially circular cross-sectional shape extending in the front-rear direction. The drug solution passage hole 123 is in fluid communication with the drug solution storage space 117 and allows the drug solution to pass through when the plunger 107 is pushed forward. As described later, it has a circular cross-section of the drug solution passage hole 123, and its diameter Φ5 is equal to or slightly larger than the inner diameter Φ1 of the needle and smaller than the outer diameter Φ2 of the needle.

[0015] As shown in FIG. 2, the needle hub 103 is formed with a concave portion 111 at the rear end that fits with the fitting portion 113 of the syringe 105. The shape of the concave portion 111 is preferably made to match the shape of the fitting portion 113. By doing so, the friction between the needle hub 103 and the syringe 105 can be increased, and the needle hub 103 and the syringe 105 can be fixed.

[0016] As shown in Fig. 3, the needle hub 103 is provided with a needle hole 137 for mounting the needle 109 on the front side of the recess 111. The needle hole 137 has a circular cross-section. The diameter Φ3 of the needle hole 137 is equal to the outer diameter Φ2 of the needle, or the diameter Φ3 of the needle hole 137 is slightly larger than the outer diameter Φ2 of the needle 109 in order to sandwich an adhesive between the needle hole 137 and the needle 109. At the rear end of the needle hole 137, a needle pressing portion 139 of the needle hole with a smaller diameter Φ3 of the needle hole is provided. The needle 109 is inserted into the needle hole 137, and the rear end of the needle 109 abuts against the front end of the needle pressing portion 139 of the needle hole and is positioned in the length direction. The length of the needle pressing portion 139 of the needle hole is shorter than the length of the needle 109 inserted into the needle hole 137 and is 0.3 mm to 1 mm. The diameter Φ4 of the needle pressing portion 139 of the needle hole is larger than the inner diameter Φ1 of the needle and smaller than the outer diameter Φ2 of the needle. Also, the diameter Φ4 of the needle pressing portion 139 of the needle hole is larger than the diameter Φ5 of the chemical solution passage hole 123. The relationship among the inner diameter Φ1 of the needle 109, the outer diameter Φ2 of the needle 109, the diameter Φ3 of the needle hole 137, the diameter Φ4 of the needle pressing portion 139 of the needle hole, and the diameter Φ5 of the chemical solution passage hole is expressed as follows. Φ1≦Φ5<Φ4<Φ2≦Φ3 By doing so, when the needle hub 103 is fixed to the syringe 105 and the needle 109 communicates with the chemical solution passage hole 123 to allow the chemical solution to pass through, even if the central axes of the needle 109 and the chemical solution passage hole 123 are slightly deviated, the chemical solution can flow smoothly. If there is no problem with the deviation of the central axes of the needle 109 and the chemical solution passage hole 123 for chemical solution injection, the needle pressing portion 139 of the needle hole may not be provided, and the needle 109 and the chemical solution passage hole 123 may communicate directly.

[0017] As shown in Fig. 3, when the fitting portion 113 is fitted with the recess 111, the front surface 121 of the fitting portion contacts the bottom surface 119 of the recess. By doing so, the dead space of the chemical solution is eliminated and the chemical solution loss is eliminated. Also, the central axis of the needle 109 substantially coincides with the central axis of the chemical solution passage hole 123. Therefore, the needle 109 is in fluid communication with the chemical solution passage hole 123, and the chemical solution flows from the chemical solution storage space 117 through the chemical solution passage hole 123 to the needle 109.

[0018] As shown in FIG. 2, a concave shape 127 extending around the entire circumference may be formed at the base of the fitting portion 113. Further, a convex shape 125 extending around the entire circumference may be formed at the opening of the concave portion 111. As shown in FIG. 3, the convex shape 125 engages with the concave shape 127 to maintain the fitting state of the fitting portion 113 and the concave portion 111. Here, the concave shape 127 is formed around the entire circumference of the fitting portion 113, and the convex shape 125 is formed around the entire circumference of the concave portion 111. However, a concave shape may be formed in the fitting portion 113 and a convex shape may be formed in the concave portion 111, and the concave shape and the convex shape may engage with each other to maintain the fitting state of the fitting portion 113 and the concave portion 111. Further, although the concave shape and the convex shape are provided at the base of the fitting portion 113 and the opening of the concave portion 111, the concave shape and the convex shape may be provided at the tip of the fitting portion 113 and the inner part of the concave portion 111. Further, the concave shape and the convex shape may be provided at an intermediate portion between the tip and the base of the fitting portion 113 and at an intermediate portion between the inner part and the opening of the concave portion 111. In any case, when the fitting portion 113 engages with the concave portion 111, the positions of the concave shape and the convex shape that engage with each other are determined so that the front surface 121 of the fitting portion 113 contacts the bottom surface of the concave portion 111.

[0019] As shown in FIG. 2, a recess 131 may be formed at a substantially central position in the plan view of the front surface 121 of the fitting portion 113. Further, a protrusion 129 may be formed on the bottom surface 119 of the concave portion 111. As shown in FIG. 3, when fitting, the protrusion 129 engages with the recess 131 to position the central axis of the needle 109 and the central axis of the chemical solution passage hole 123. By doing so, the needle 109 and the chemical solution passage hole 123 are in fluid communication, and the chemical solution can flow from the chemical solution storage space 117 through the chemical solution passage hole 123 to the needle 109. Here, the recess 131 is formed in the fitting portion 113 and the protrusion 129 is formed in the concave portion 111. However, a protrusion may be formed in the fitting portion 113, a recess may be formed in the concave portion 111, and the protrusion may engage with the recess to position the central axis of the needle 109 and the central axis of the chemical solution passage hole 123.

[0020] As shown in FIG. 2, it is preferable that the fitting portion 113 has a frustum shape having a side surface 135 with a slope of 5% or more and 7% or less, and it is more preferable that the side surface 135 of the fitting portion has a slope of 6%. Further, it is preferable that the inner surface of the corresponding concave portion 111 also has a shape of a side surface 133 that narrows from the opening to the bottom surface 119 with a slope of 5% or more and 7% or less, and it is more preferable that the side surface 133 of the concave portion has a slope of 6%. Also, as shown in FIG. 2, the length of the fitting portion and the length L of the chemical solution passage hole are from 6.0 mm to 8.0 mm, preferably greater than 7.0 mm and 8.0 mm or less. The radius of the front surface 121 of the fitting portion 113 is from 4.40 mm to 4.44 mm, and it is preferable that the bottom surface 119 of the concave portion 111 has a size corresponding to the front surface 121 of the fitting portion 113. Although it is preferable to shorten the length L of the chemical solution passage hole in order to reduce the dead space, a length having sufficient fitting strength by the fitting portion is required. By making it such a shape and size, it is easy to assemble the needle hub 103 to the syringe 105, and it can be fixed so that the needle hub 103 does not come off from the syringe 105 when injecting.

[0021] The inner diameter Φ1 of the needle 109 is preferably from 0.09 mm to 0.32 mm. The outer diameter Φ2 of the needle 109 is preferably from 0.214 mm to 0.64 mm. As described above, the inner diameter Φ5 of the chemical solution passage hole 123 is the same as or slightly larger than the inner diameter Φ1 of the needle 109 and smaller than the outer diameter Φ2 of the needle. Therefore, the inner diameter Φ5 of the chemical solution passage hole 123 is preferably from 0.1 mm to 0.5 mm, or from 0.1 mm to 0.2 mm, or from 0.3 mm to 0.5 mm. By making the inner diameter Φ5 of the chemical solution passage hole 123 the same as or slightly larger than the inner diameter Φ1 of the needle 109, the dead space can be reduced and the chemical solution loss can be decreased. Also, the length of the needle 109 is made sufficiently larger than the length of the chemical solution passage hole 123. The length of the needle 109 is, for example, from 2.5 cm to 6 cm. Even if the inner diameter Φ5 of the chemical solution passage hole 123 is made equal to the inner diameter Φ1 of the needle 109, the pushing pressure only increases by the amount by which the length of the chemical solution passage hole 123 increases from 6.0 mm to 6.2 mm with respect to the length of the needle 109 from 3 cm to 6 cm. Therefore, the plunger can be pushed in without much increase in pressure.

[0022] The needle hub 103 is preferably formed of polycarbonate or polypropylene, and the syringe 105 is preferably formed of polypropylene. By making the needle hub 103 of polycarbonate or polypropylene, when fitting the needle hub 103 and the syringe 105, it is possible to obtain a frictional force that is easy to assemble and that the needle hub 103 does not come off from the syringe 105 when injecting. Also, by making the syringe 105 of polypropylene, it is possible to make a needle hole and a chemical solution passage hole 123 of a desired diameter.

[0023] The syringe assembly of the present invention has a reduced dead space where the chemical solution remains and is easy to assemble.

[0024] (Second syringe assembly with a needlestick prevention device) FIG. 4 is a schematic view of (a) a syringe assembly with a needlestick prevention device and (b) a schematic cross-sectional view taken along line C-C of FIG. 4(a) according to one embodiment of the present invention. FIG. 5 is a schematic view of (a) a syringe assembly with a needlestick prevention device engaged with a needle hub and (b) a schematic cross-sectional view taken along line D-D of FIG. 5(a) according to one embodiment of the present invention. FIG. 6 is a schematic view of (a) removing a needle hub from a syringe with a needlestick prevention device and (b) a schematic cross-sectional view taken along line E-E of FIG. 6(a) according to one embodiment of the present invention. Referring to FIGS. 4 to 6, a second syringe assembly 201 with a needlestick prevention device, which is one embodiment of the present invention, will be described.

[0025] As shown in FIG. 4(a), the second syringe assembly 201 with a needlestick prevention device includes a needle hub 203 similar to the first syringe assembly 101 described above, a syringe 205, and a plunger 207, and further includes a needlestick prevention device 209. The needlestick prevention device 209 of the present invention is a member used when removing the needle hub 203 fitted to the syringe 205 from the syringe 205. However, the second syringe assembly 201 may be a syringe other than the syringe with the reduced dead space described above.

[0026] As shown in FIG. 4(b), the needle-stick prevention device 209 includes a hollow cylindrical body 213 having an inner shape that is larger than the outer shape 217 of the needle hub except for the inner narrow portion 211, and an inner shape that is larger than the outer shape 215 of the syringe body including the inner narrow portion 211. That is, as shown in FIG. 4(b), if the syringe 205 is a cylindrical body, it is preferable that the needle-stick prevention device 209 is a hollow cylindrical body having an inner diameter larger than the outer diameter of the cylindrical body including the inner diameter narrow portion. If the syringe 205 is a triangular prism, a quadrangular prism, an elliptical cylinder, etc., the hollow cylindrical body 213 can have an inner shape corresponding to the triangular prism, quadrangular prism, elliptical cylinder, etc. Even when the syringe 205 has a tapered outer shape from the rear end to the front end, similarly, the hollow cylindrical body 213 has a shape that covers the syringe 205 with an inner shape larger than the outer shape 215 of the syringe body.

[0027] The outer shape 217 of the needle hub is larger than the inner narrow portion 211. As shown in FIG. 4(b), one form thereof is a flange that protrudes in the circumferential direction of the cross-section of the syringe 205 and has a portion larger than the outer shape of the syringe 205 in the circumferential direction. The cross-sectional shape of the flange may be a polygon, an ellipse, or a circle. The cross-sectional shape of the flange is preferably a cross-sectional shape that coincides with the cross-sectional shape of the inner narrow portion 211. In one embodiment, the cross-sectional shape of the flange is circular, and the cross-sectional shape of the inner narrow portion 211 is circular. The outer shape 217 of the needle hub is not limited to this and can take various forms.

[0028] The needle-stick prevention device 209 of the present invention is such that a hollow cylinder 213 is attached to the outside of a syringe 205 with no needle hub 203 attached thereto. A needle hub 203 is fitted to the front end portion 219 of the syringe with the hollow cylinder 213 attached thereto, and a second syringe assembly 201 is assembled. After injection, when the needle hub 203 fitted to the syringe 205 is removed from the syringe in order to discard the needle hub 203, as shown in Fig. 5(a), the needle-stick prevention device 209 is slid to the front end portion of the syringe. As shown in Fig. 5(b), when the hollow cylinder 213 moves forward, the inner shape narrow portion 211 engages with the outer shape 217 of the needle hub in a state where the entire needle hub 203 including the needle 221 is covered with the hollow cylinder 213. As shown in Figs. 6(a) and (b), when the hollow cylinder 213 further moves forward, the needle hub 203 is removed from the syringe 205 in a state of being covered with the hollow cylinder 213.

[0029] The inner shape narrow portion 211 has an inclined surface that gently narrows from the front side to the rear side. As shown in Fig. 4(b), the inner shape narrow portion 211 can be provided at any position in the front or rear of the needle-stick prevention device 209, but it is preferably located at the rear end of the needle-stick prevention device 209. By doing so, the entire needle 221 including the needle hub 203 can easily fit into the needle-stick prevention device 209.

[0030] As shown in Fig. 6(b), since the length of the hollow cylinder 213 is longer than the length of the needle hub 203 including the needle 221, the entire needle 221 can be accommodated in the hollow cylinder 213. Since the entire needle 221 is covered with the needle-stick prevention device 209, there is no risk that a medical worker will be accidentally pricked by the needle when removing the needle hub 203. Also, as shown in Fig. 6(b), the needle hub 203 engages with and is fixed to the needle-stick prevention device 209. Therefore, even if the needle 221 and the needle hub 203 are discarded together with the needle-stick prevention device 209, there is no risk that a medical worker will be accidentally pricked by the needle, nor is there any risk that a medical worker will touch the patient's blood or body fluid remaining on the needle and the needle hub.

[0031] Also, as shown in FIG. 4(b), the rear end portion of the hollow cylinder 213 preferably includes an engaging portion 223 that engages with a flange 227 formed at the rear end portion of the syringe 205. By engaging the engaging portion 223 of the hollow cylinder 213 with the flange 227 of the syringe 205, the movement of the hollow cylinder 213 relative to the syringe 205 is restricted. By doing so, during injection, the hollow cylinder 213 does not move away from the syringe 205, making the injection operation easier.

[0032] As shown in FIG. 6(b), a concave shape 231 extending over the entire circumference is formed at the base of the front end portion 219 of the syringe. Further, it is preferable that a convex shape 229 extending over the entire circumference is formed at the opening of the recess 225. By doing so, the fitting between the needle hub 203 and the syringe 205 can be strengthened and prevented from coming off during injection. On the other hand, after injection, the needle hub 203 and the syringe 205 can be easily removed using the needle stick prevention device 209 of the present invention.

[0033] The present invention provides a needle stick prevention device that separates the needle hub and the syringe to protect and discard the needle.

[0034] The description of the above embodiments is illustrative in all respects and not restrictive. Modifications and changes are appropriately possible for those skilled in the art. The scope of the present invention is indicated not by the above embodiments but by the claims. Further, the scope of the present invention includes modifications from the embodiments within the scope equivalent to the claims.

Industrial Applicability

[0035] Using the syringe assembly provided by the present invention, an injection with less loss of the chemical solution can be performed. Also, using the needle stick prevention device provided by the present invention, the needle hub can be safely discarded.

Explanation of Signs

[0036] 101 First syringe assembly 103 Needle hub 105 Syringe 107 Plunger 109 Needle 111 Recess 113 Fitting portion 115 Rear side of the syringe 117 Chemical solution storage space 119 Bottom surface of the recess 121 Front surface of the fitting portion 123 Chemical solution passage hole 125 Convex shape 127 Concave shape 129 Protrusion 131 Depression 133 Side surface of the recess 135 Side surface of the fitting portion 137 Needle hole 139 Needle pressing portion of the needle hole 201 Second syringe assembly 203 Needle hub 205 Syringe 207 Plunger 209 Needle stick prevention device 211 Inner narrow portion 213 Hollow cylinder 215 Outer shape of the syringe body 217 Outer shape of the needle hub 219 Front end portion of the syringe 221 Needle 223 Engagement portion 225 Recess 227 Flange 229 Convex shape 231 Concave shape

Claims

1. A syringe having a fitting portion that is substantially cylindrical or substantially frustoconical and formed at the front end, and a chemical solution passage hole that is provided in the fitting portion and has a substantially circular cross-sectional shape extending in the front-rear direction, a needle hub having a recess that fits with the fitting portion formed at the rear end, and a needle hole provided with a needle mounted on the front side of the recess, when the fitting portion and the recess are fitted, the front surface of the fitting portion and the bottom surface of the recess are in contact, and the central axis of the needle and the central axis of the chemical solution passage hole are substantially coincident, the inner diameter of the chemical solution passage hole is equal to or larger than the inner diameter of the needle and smaller than the outer diameter of the needle, assuming that the inner diameter of the needle is Φ1, the outer diameter of the needle is Φ2, the diameter of the needle hole for inserting the needle provided in the needle hub is Φ3, the diameter of the needle pressing portion of the needle hole for positioning the needle in the longitudinal direction provided in the needle hub is Φ4, and the diameter of the chemical solution passage hole is Φ5, Φ1 ≦ Φ5 < Φ4 < Φ2 ≦ Φ3 A syringe assembly represented by the relational expression of.

2. The syringe assembly according to claim 1, wherein the syringe has a chemical solution storage space into which a plunger is inserted, and the chemical solution passage hole communicates with the chemical solution storage space.

3. A convex shape extending over the entire circumference is formed on either the base portion of the fitting portion or the opening portion of the recess, and a concave shape extending over the entire circumference is formed on the other, and the convex shape and the concave shape are engaged to maintain the fitting state of the fitting portion and the recess. The syringe assembly according to claim 1 or 2.

4. A protrusion is formed at either the substantially central position in plan view of the front surface of the fitting portion and the bottom surface of the recess that come into contact during fitting, and a depression is formed on the other, and the protrusion and the depression are engaged to position the central axis of the needle and the central axis of the chemical solution passage hole. The syringe assembly according to any one of claims 1 to 3.

5. The fitting portion has a frustoconical shape having a slope of 5% or more and 7% or less, The inner surface of the corresponding recess also has a shape that narrows from the opening to the bottom surface with a slope of 5% or more and 7% or less. The syringe assembly according to any one of claims 1 to 4.

6. The syringe assembly according to any one of claims 1 to 5, wherein the needle hub is formed of polycarbonate or polypropylene, and the syringe is formed of polypropylene.

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