Syringe safety device to be attached to syringe, and safety device-equipped syringe

Abstract

To provide a syringe safety device that enables locking means to be reliably unlocked; and a safety device-equipped syringe with the syringe safety device attached thereto.SOLUTION: In a safety device-equipped syringe 1, a syringe 10 is equipped with an inner tube 20, an outer tube 30, an ejector 40, and a spring member 50. Thereby, after the injection is completed, a plunger flange 14 and the ejector 40 that are integrated are pushed to cause a pair of inner tube deflectable pieces 21 of the inner tube 20 to bend inward, thereby capable of releasing the fixation between the inner tube 20 and the outer tube 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a safety device for a syringe that is pre-filled with a medicinal solution and that can move an outer cylinder that covers a puncture needle from a use position to a protection position after use, and to a syringe with a safety device equipped with this syringe safety device. [Background technology]

[0002] Background Art There are known syringe safety devices attached to syringes to prevent reuse of a syringe that has been used once and to prevent accidental contact with a puncture needle after use (see Patent Document 1).

[0003] This conventional syringe safety device comprises: an outer tube which is cylindrically shaped to be fitted onto the barrel of the syringe, and which has a large diameter section connected to the rear end of a small diameter section via a step section; an inner tube which is cylindrically shaped to be inserted into the gap between the barrel and the outer tube, and which is capable of accommodating a puncture needle, and which is capable of sliding along the outer circumferential surface of the barrel; a spring member which is built into the inner tube and which urges the inner tube forward relative to the outer tube; a locking means which locks the inner tube to the outer tube against the urging force of the spring member in a usage position where the puncture needle protrudes from its tip; and an ejector which is fixed to a plunger flange section of the syringe, is cylindrically shaped to be insertable into the outer tube, and which releases the locking by the locking means.

[0004] This locking means is configured such that a locking portion is provided at the base end of the inner cylinder, bulging in a direction away from the axis, and is locked onto the rear end surface of the stepped portion of the outer cylinder.

[0005] In addition, in this conventional syringe safety device, the inside of the large diameter part of the outer barrel is provided with an outer barrel fixing part that extends rearward from four equally spaced positions in the circumferential direction and snap-fits the barrel flange part, and a pair of elastic tabs that are arranged in the gaps in the outer barrel fixing part in the circumferential direction. The outer barrel fixing part is substantially L-shaped, approaching the axis of the puncture needle from the inner circumferential surface of the large diameter part and then bending rearward, and the elastic tab is inclined so as to gradually approach the axis as it moves rearward from the inner circumferential surface of the large diameter part.

[0006] In a conventional syringe safety device having this configuration, when the plunger is pushed forward to discharge the liquid medicine, the peripheral edge of the tip of the cylindrical ejector pushes down the pair of elastic tabs in a direction in which their tips approach each other. The elastic tabs then push the locking portion of the inner cylinder in a direction approaching the axis and separate it from the rear end face of the stepped portion of the outer cylinder, releasing the locking by the locking means. As a result, the inner cylinder is pushed forward by the biasing force of the spring member to a protection position in which the puncture needle is stored up to its tip.

[0007] As described above, in the conventional syringe safety device, the puncture needle is covered by the inner cylinder at the same time as the medicinal liquid is discharged, thereby preventing accidental contact with the puncture needle after use. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Special Publication No. 2007-508883 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in conventional syringe safety devices, the forward movement of the ejector causes the elastic tab to swing, and the swinging elastic tab pushes the locking portion of the inner cylinder closer to the axis. As a result, the release of the lock by the ejector is indirect, and there is a risk that the release of the lock will not operate smoothly, particularly if the plunger is tilted even slightly relative to the barrel.

[0010] Therefore, the present invention has been made in consideration of the above problems, and has an object to provide a syringe safety device that can reliably release the locking of the locking means, and a syringe with a safety device equipped with this syringe safety device. [Means for solving the problem]

[0011] The syringe safety device of the present invention is a syringe safety device that is attached to a syringe comprising: a barrel having a puncture needle at a front end and a barrel flange portion at a rear end, in which a medicinal solution is contained; and a plunger whose front end is slidably inserted from the rear end side of the barrel and has a plunger flange portion at its rear end, wherein the syringe safety device is configured such that, when a direction along the axis of the puncture needle is defined as a front-rear direction, a first direction perpendicular to the front-rear direction is defined as a top-down direction, and a second direction perpendicular to the front-rear direction and the top-down direction is defined as a left-right direction, The safety device for the shooter includes an inner tube that is tubular and fitted to the outside of the barrel and fixed to the barrel flange portion, an outer tube that is tubular and can house the puncture needle by being fitted to the outside of the barrel and the inner tube and can slide along the outer circumferential surface of the barrel, a spring member that is built into the outer tube and biases the inner tube rearward relative to the outer tube, a locking means that locks the inner tube against the biasing force of the spring member in a use position where the puncture needle protrudes from the front end of the outer tube, and a locking hand that locks the inner tube against the biasing force of the spring member. and an ejector for releasing the engagement by a step, the inner tube being provided at its rear end and having an inner tube fixing part fitted to the outside of the barrel flange part, and a pair of inner tube swinging pieces extending rearward from the outer peripheral surface of the inner tube beyond the outer diameter of the inner tube fixing part and swingable up and down, the ejector being tubular extending forward from the periphery of the plunger flange part and insertable into the gap between the outer tube and the inner tube fixing part, and having a front end for insertion into the gap between the outer tube and the inner tube swinging pieces. the plunger and the ejector release portion are configured to be capable of being locked in a use position by engaging the inner cylinder oscillating piece with the outer cylinder, and the ejector release portion is configured to be released by displacing the plunger and the ejector release portion forward, causing the ejector release portion to be pushed into a gap between the outer cylinder and the inner cylinder oscillating piece and displacing the inner cylinder oscillating piece in a direction approaching the axis (hereinafter referred to as the "first syringe safety device of the present invention").

[0012] In the first syringe with a safety device of the present invention, the ejector is cylindrical and extends forward from the periphery of the plunger flange portion so as to be insertable into the gap between the outer cylinder and the inner cylinder fixing portion. Therefore, when the ejector is displaced forward via the plunger, the ejector passes through the gap between the outer cylinder and the inner cylinder fixing portion and is disposed behind the inner cylinder swing piece.

[0013] The ejector has an ejector release portion at its front end that can be inserted into the gap between the outer tube and the inner tube oscillating piece, so that when the ejector is displaced forward via the plunger, the ejector release portion at its front end is pushed into the gap between the outer tube and the inner tube oscillating piece, displacing the inner tube oscillating piece toward the axis, thereby releasing the locking action performed by the locking means.

[0014] Therefore, according to the first syringe safety device of the present invention, the ejector is provided directly on the plunger, and the locking is released directly by the ejector, so that the locking of the locking means can be reliably released.

[0015] A syringe safety device to be attached to a syringe including: a barrel having a puncture needle at a front end and a barrel flange portion at a rear end, the barrel containing a medicinal solution; and a plunger having a plunger flange portion at its rear end, the front end of which is slidably inserted from the rear end side of the barrel, the plunger having a plunger flange portion at its rear end, the syringe safety device comprising: a syringe having an inner cylinder that is tubular and fitted to the outside of the barrel, the inner cylinder being fixed to the barrel flange portion; The present invention comprises an outer tube having a cylindrical shape capable of accommodating the puncture needle by being fitted to the outside of the barrel and the inner tube and capable of sliding along the outer circumferential surface of the barrel, a spring member built into the outer tube and biasing the inner tube rearward relative to the outer tube, a locking means for locking the inner tube against the biasing force of the spring member in a use position in which the puncture needle protrudes from the front end of the outer tube, and an ejector for releasing the locking by the locking means, the inner tube having a cylindrical inner tube main body and an inner tube main body extending rearward from the left and right ends of the rear end of the inner tube main body, the rear end of which has a U shape when viewed in the up and down direction. The barrel flange portion has a pair of inner tube fixing portions bent in a U-shape and fitted to the outside of the barrel flange portion, a pair of inner tube swinging pieces extending rearward from the vertical end of the rear end of the inner tube main body portion to a position forward of the front end of the barrel flange portion with a circumferential gap from each of the pair of inner tube fixing portions and swinging in the vertical direction, an inner tube release portion provided at the rear end of the inner tube swinging piece, and an inner tube locking portion provided adjacent to the front side of the inner tube release portion of the inner tube swinging piece with a gap therebetween and bulging in the vertical direction away from the axis, and the inner tube release portion gradually moves rearward away from the axis. the ejector is tubular and extends forward from the periphery of the plunger flange portion so as to be insertable into the gap between the outer cylinder and the inner cylinder fixing portion, and has an ejector releasing portion at its front end which can be inserted into the gap between the outer cylinder and the inner cylinder releasing portion; the outer cylinder has an outer cylinder locking portion which extends from the vertical end of its inner circumferential surface in a direction approaching the axis and which is disposed in the gap between the inner cylinder locking portion and the inner cylinder releasing portion at the usage position; and the locking means isThe outer cylinder is fitted onto the outside of the inner cylinder from the front end side toward the rear, and the rear end of the inner cylinder locking portion is engaged with the front end of the outer cylinder locking portion, so that the outer cylinder can be locked at the use position; when the plunger and the ejector release portion are displaced toward the front, the ejector release portion is pushed into the gap between the outer cylinder and the inner cylinder releasing portion, and the inner cylinder rocking piece including the inner cylinder releasing portion and the inner cylinder releasing portion is displaced in a direction approaching the axis, and the inner cylinder locking portion provided on the inner cylinder rocking piece is separated from the outer cylinder locking portion, thereby releasing the lock (hereinafter referred to as the "second syringe safety device of the present invention").

[0016] In the syringe safety device of the second invention, the locking means locks the puncture needle in the use position by engaging the outer cylinder locking portion of the outer cylinder with the inner cylinder locking portion provided on the inner cylinder swinging piece of the inner cylinder. In contrast, the ejector of the syringe with safety device of the first invention is cylindrical and extends forward from the periphery of the plunger flange portion so as to be insertable into the gap between the outer cylinder and the inner cylinder fixing portion. Therefore, when the ejector is displaced forward via the plunger, the ejector passes through the gap between the outer cylinder and the inner cylinder fixing portion and is positioned behind the inner cylinder release portion.

[0017] The ejector has an ejector release portion at its front end that can be inserted into the gap between the outer tube and the inner tube release portion, so that when the ejector is displaced forward via the plunger, the ejector release portion at its front end is pushed into the gap between the outer tube and the inner tube release portion, displacing the inner tube release portion toward the axis.

[0018] Since this inner cylinder release part is provided on an inner cylinder swinging piece that can swing up and down, when the inner cylinder release part is displaced toward the axis, the inner cylinder swinging piece on which it is provided is displaced toward the axis. And since the inner cylinder locking part described above is also provided on this inner cylinder swinging piece, the inner cylinder locking part is also displaced toward the axis together with the inner cylinder release part and the inner cylinder swinging piece by the forward movement of the ejector. As a result, the inner cylinder locking part is separated from the outer cylinder locking part described above, and the locking by the locking means is released.

[0019] Therefore, according to the second syringe safety device of the present invention, the ejector is provided directly on the plunger, and the locking is released directly by the ejector, so that the locking of the locking means can be reliably released.

[0020] In the syringe safety device of the second invention of the present invention, it is preferable that the ejector release portion is provided with an inclined guide portion whose inner diameter gradually increases toward the front end (hereinafter referred to as the "syringe safety device of the third invention of the present invention").

[0021] In the syringe safety device of the third invention, since the ejector releasing portion is formed with an inclined guide portion whose inner diameter gradually increases toward the front end, when the ejector is displaced forward, the inclined guide portion can push down the inner cylinder releasing portion while sliding it toward the axis. This makes it possible to push down the inner cylinder rocking piece provided with the inner cylinder releasing portion together with the inner cylinder locking portion provided thereon, and separate it from the outer cylinder locking portion, thereby releasing the locking by the locking means.

[0022] Therefore, according to the syringe safety device of the third aspect of the present invention, the locking of the locking means can be released more reliably.

[0023] In addition, the inner cylinder release part pushed down by the inclined guide part is pushed into the internal space of the ejector by the inclined guide part which continues to advance. Since the ejector and plunger are guided between the outer cylinder and the barrel, the ejector and plunger are integrated with the inner cylinder and the barrel. Therefore, in the syringe safety device of the second invention, when the locking of the locking means is released, the ejector, plunger, inner cylinder and barrel are moved backward as a unit with respect to the outer cylinder, and the puncture needle can be reliably covered by the outer cylinder.

[0024] In the third syringe safety device of the present invention, it is preferable that the inner cylinder release portion is provided at its rear end and has an inner cylinder claw portion that is convex in the vertical direction away from the axis, and the ejector release portion has a claw storage portion that is provided adjacent to the rear of the inclined guide portion and is formed concave in the vertical direction away from the axis and is capable of storing the inner cylinder claw portion (hereinafter referred to as the "fourth syringe safety device of the present invention").

[0025] In the syringe safety device of the fourth aspect of the present invention, the inner cylinder claw portion is formed on the inner cylinder releasing portion so as to face the inclined guide portion of the ejector releasing portion, so that when the ejector is displaced forward, the inclined guide portion and the inner cylinder claw portion slide against each other to push the inner cylinder releasing portion down toward the axis. This makes it possible to push down the inner cylinder rocking piece provided with the inner cylinder releasing portion together with the inner cylinder locking portion provided thereon to separate it from the outer cylinder locking portion, thereby releasing the locking by the locking means.

[0026] Therefore, according to the syringe safety device of the fourth aspect of the present invention, the locking of the locking means can be released more reliably.

[0027] Furthermore, the inner cylinder claw portion pushed down by the inclined guide portion is guided into the internal space of the ejector by the inclined guide portion continuing to advance, and is stored in the claw storage portion provided adjacent to the rear of the inclined guide portion.

[0028] Therefore, the ejector and plunger are more securely integrated with the inner cylinder and barrel, so that in the syringe safety device of the fourth invention, when the locking means is released, the ejector, plunger, inner cylinder and barrel are retracted together relative to the outer cylinder, and the puncture needle can be securely covered by the outer cylinder.

[0029] In the second syringe safety device of the present invention, it is preferable that the outer barrel has a cylindrical outer barrel main body portion having an inner diameter equal to or larger than the outer diameter of the inner barrel main body portion and smaller than the outer diameter of the inner barrel fixing portion, and an outer barrel large diameter portion connected to a rear end of the outer barrel main body portion via an outer barrel step portion, having a cylindrical outer diameter larger than that of the outer barrel main body portion, and slidably housing the ejector, and that a first window portion is formed at an end in the vertical direction of the rear end of the outer barrel main body portion, which penetrates the outer barrel main body portion in the vertical direction and houses the inner barrel locking portion in the use position, and that the outer barrel locking portion is constituted by an inner surface on the rear end side of the first window portion, and is configured so that a portion from the inner surface on the rear end side of the first window portion to the rear end of the outer barrel step portion is disposed in a gap between the inner barrel locking portion and the inner barrel releasing portion in the use position (hereinafter referred to as "the syringe safety device of the fifth invention").

[0030] In the fifth syringe safety device of the present invention, the outer cylinder has a cylindrical outer cylinder main body and a cylindrical outer cylinder large diameter part that is connected to the rear end of the outer cylinder main body via an outer cylinder step part and has an outer diameter larger than that of the outer cylinder main body. This outer cylinder main body has an inner diameter equal to or larger than the outer diameter of the inner cylinder main body and smaller than the outer diameter of the inner cylinder fixing part, and the outer cylinder large diameter part is large enough to slidably accommodate an ejector having an outer diameter larger than that of the inner cylinder fixing part. Therefore, the outer cylinder can be accommodated inside the inner cylinder by covering the tip side of the inner cylinder with this outer cylinder.

[0031] In addition, a first window portion that accommodates the inner tube engagement portion is formed at the rear end portion of the outer tube main body portion described above. Therefore, when placing the outer tube over the inner tube, the inner tube engagement portion of the inner tube can be accommodated in the first window portion of the outer tube, thereby enabling the inner tube to be engaged with the outer tube against the biasing force of the spring member.

[0032] Furthermore, since the inner surface of the rear end side of the first window portion to the rear end of the outer tube step portion is positioned in the gap between the inner tube locking portion and the inner tube release portion in the usage position, by quickly pushing the ejector all the way toward the outer tube step portion at the back (front end) of the large diameter portion of the outer tube, the inner tube locking portion can be pushed down and separated from the outer tube locking portion, thereby releasing the locking by the locking means.

[0033] Therefore, according to the syringe safety device of the fifth aspect of the present invention, the locking of the locking means can be released more reliably.

[0034] In the fifth syringe safety device of the present invention, it is preferable that the inner barrel main body has a pair of second inner barrel grooves extending rearward from its front end along an extension line of a side edge of the inner barrel swinging piece, a return prevention piece sandwiched between the pair of second inner barrel grooves and swingable up and down, and a return prevention part provided at the front end of the return prevention piece and extending forward and inclined in a direction gradually away from the axis to a position larger than the inner diameter of the outer barrel main body and equal to or smaller than the outer diameter, the return prevention part engaging with an inner surface on the front end side of the first window, the return prevention part being housed in the outer barrel at the usage position by fitting the outer barrel to the outside while pressing down the return prevention piece in a direction approaching the axis, and the return prevention part being displaced rearward with respect to the outer barrel by the biasing force of the spring member when the locking is released (hereinafter referred to as "the sixth syringe safety device of the present invention").

[0035] In the sixth syringe safety device of the present invention, the inner cylinder is provided with a vertically swingable return prevention piece. This return prevention piece is housed in the outer cylinder at the use position by fitting the outer cylinder to the outside while pushing it down in the direction approaching the axis, but when the return prevention piece is displaced rearward by the biasing force of the spring member after the lock is released and the return prevention piece retreats to the first window of the outer cylinder, it elastically deforms and expands in the vertical direction so as to enter the internal space of the first window.

[0036] Furthermore, a return prevention portion is formed at the tip of this return prevention piece which engages with the inner surface of the front end side of the first window portion of the outer tube, so that even if the inner tube is advanced (displaced forward) relative to the outer tube in an attempt to return the puncture needle to the usage position again, the return prevention portion of the inner tube engages with the first window portion of the outer tube, preventing further advancement.

[0037] Therefore, according to the syringe safety device of the sixth aspect of the present invention, it is possible to further prevent reuse of a syringe that has been used once, and also to prevent accidental contact with a puncture needle after use.

[0038] In the sixth syringe safety device of the present invention, it is preferable that the outer barrel main body is formed with a second window portion which penetrates the outer barrel main body in the vertical direction and houses the return prevention portion at a position facing the return prevention portion in the use position (hereinafter referred to as the "seventh syringe safety device of the present invention").

[0039] In the syringe safety device of the seventh aspect of the present invention, since the anti-return piece can be stored in the second window portion in the use position, the anti-return piece is not held in a state pressed down by the inner circumferential surface of the outer cylinder from the time of assembly until use. Therefore, it is possible to prevent the anti-return piece from becoming difficult to elastically deform due to aging, and the anti-return part of the inner cylinder can be reliably engaged with the first window portion of the outer cylinder.

[0040] Therefore, according to the syringe safety device of the seventh aspect of the present invention, it is possible to further prevent reuse of a syringe that has been used once, and also to prevent accidental contact with a puncture needle after use.

[0041] In the seventh syringe safety device of the present invention, it is preferable that the front end surface of the return prevention portion is formed concavely toward the rear when viewed in the left-right direction, and the inner surface of the front end side of the first window portion is formed convexly toward the rear when viewed in the left-right direction and is capable of engaging with the return prevention portion (hereinafter referred to as the "eighth syringe safety device of the present invention").

[0042] In the eighth syringe safety device of the present invention, the inner surface of the return prevention portion of the inner tube and the inner surface of the front end side of the first window portion of the outer tube, which collide when the inner tube is advanced relative to the outer tube to return the puncture needle to the usage position again, are formed concavely and convexly, respectively, so that they can be fitted together, thereby more reliably preventing further advancement.

[0043] Therefore, according to the syringe safety device of the eighth aspect of the present invention, it is possible to further prevent reuse of a syringe that has been used once, and also to prevent accidental contact with a puncture needle after use.

[0044] The syringe with a safety device of the present invention is characterized in that it comprises the syringe and any one of the first to eighth safety devices for a syringe of the present invention attached to the syringe (hereinafter referred to as the "ninth syringe with a safety device of the present invention").

[0045] According to the ninth aspect of the present invention, in the syringe with a safety device, the ejector is provided directly on the plunger, and the locking is released directly by the ejector, so that the locking of the locking means can be released reliably. [Brief description of the drawings]

[0046] [Figure 1A] FIG. 1 is a perspective view showing an embodiment of a syringe with a safety device according to the present invention, in a state prior to use. [Figure 1B] FIG. 1 is a perspective view showing an embodiment of a syringe with a safety device according to the present invention, in a state after use. [Diagram 2] FIG. 1 is an exploded perspective view showing the configuration of a syringe with a safety device and a syringe safety device according to the present invention. [Figure 3A] 3A is a cross-sectional view taken along line 3A-3A in FIG. 1A, showing a longitudinal cross-sectional view of a syringe with a safety device before use, which is a schematic diagram illustrating the configuration of the syringe. [Figure 3B] 3B-3B cross-sectional view of FIG. 1A, showing a schematic cross-sectional view of the configuration of a syringe with a safety device before use. FIG. [Figure 4A] 4A is a cross-sectional view taken along line 4A-4A in FIG. 1B, showing a longitudinal cross-sectional view of the syringe with a safety device after use, which is a schematic diagram illustrating the configuration of the syringe with a safety device after use. [Figure 4B] 4B-4B cross-sectional view of FIG. 1B, showing a schematic cross-sectional view of the configuration of the syringe with a safety device after use. FIG. [Diagram 5] FIG. 2 is a partial perspective view showing a schematic configuration of a tapered portion on the inner surface of the barrel of the syringe with a safety device according to the present invention; [Figure 6] FIG. 2 is a perspective view showing a schematic configuration of an ejector of the syringe with a safety device of the present invention. [Figure 7A] FIG. 2 is a first perspective view showing the assembly process of the syringe with a safety device of the present invention, illustrating the assembly state in which a spring member is inserted into an inner cylinder. [Figure 7B] FIG. 2 is a second perspective view showing the assembly process of the syringe with a safety device of the present invention, illustrating the assembly state in which the inner cylinder and the spring member are inserted into the outer cylinder. [Figure 7C] FIG. 11 is a third perspective view showing the assembly process of the syringe with a safety device of the present invention, illustrating the state of attaching the barrel. [Figure 7D] FIG. 4 is a fourth perspective view showing the assembly process of the syringe with a safety device of the present invention, illustrating the state in which the ejector is attached to the plunger flange portion. [Figure 7E] FIG. 13 is a fifth perspective view showing the assembly process of the syringe with a safety device of the present invention, illustrating the state of attaching a plunger equipped with an ejector. [Figure 8] FIG. 11 is a local cross-sectional view showing the operation of the syringe with a safety device of the present invention, illustrating the state in which the plunger flange portion is pressed, the ejector is actuated, and the inner tube locking portion of the inner tube swinging piece of the inner tube is released. [Figure 9] FIG. 2 is an enlarged cross-sectional view illustrating a state in which the return prevention piece of the syringe with safety device of the present invention is in the return prevention position. [Figure 10] FIG. 2 is a front view showing the configuration of a finger grip used in the syringe with a safety device of the present invention. [Figure 11] FIG. 2 is a plan view showing the configuration of a syringe finger grip with a safety device according to the present invention. [Figure 12] 12 is a cross-sectional view of the syringe with a safety device according to the present invention taken along the line CC in FIG. 11 . [Figure 13] FIG. 2 is a front view showing how a finger grip is attached to the syringe with a safety device of the present invention. [Figure 14] FIG. 2 is a rear perspective view showing the state in which the finger grip is attached to the syringe with safety device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] 1A to 9, a syringe with a safety device 1 and a syringe safety device 2 attached to the syringe according to one embodiment of the present invention (hereinafter simply referred to as this embodiment) will be described below. The syringe with a safety device 1 of this embodiment is a prefilled syringe that is equipped with a safety device that can protect the puncture needle after use (after injection has been completed) and contains a medicinal solution in advance, making it ready for injection.

[0048] 1A to 6 show the configuration of the safety syringe 1 of this embodiment. FIG. 1A shows the state of the safety syringe 1 of this embodiment before use, and FIG. 1B shows the state of the safety syringe 1 of this embodiment after use. FIG. 2 is an exploded perspective view showing the schematic configuration of the safety syringe 1 and the syringe safety device. FIG. 3A shows a vertical cross section of the safety syringe 1 before use, and FIG. 3B shows a horizontal cross section of the safety syringe 1 before use. FIG. 4 FIG. 4A shows a vertical cross section of the syringe with a safety device 1 in a state after use, and FIG. 4B shows a horizontal cross section of the syringe with a safety device 1 in a state after use. FIG. 5 shows the configuration of the tapered portion on the inner surface of the outer cylinder 30 of the syringe with a safety device 1, and FIG. 6 shows the configuration of the ejector 40 of the syringe with a safety device 1. Here, FIG. 3A and FIG. 4A are vertical cross sections in a plane (vertical plane) along the axis, and FIG. 3B and FIG. 4B are horizontal cross sections in a plane (horizontal plane) along the axis. In this specification, the "state before use" refers to a state before injection is performed, and the "state after use" refers to a state after injection is completed. In addition, the "tip side (corresponding to the front end side of the present invention)" refers to the side where the puncture needle is located, and the "rear end side" refers to the side where the plunger flange portion is located.

[0049] 1A to 6, the syringe with a safety device 1 includes a syringe 10, an inner cylinder 20, an outer cylinder 30, an ejector 40, a spring member 50, and a cap 60. In the present embodiment, the syringe safety device 2 includes the inner cylinder 20, the outer cylinder 30, the ejector 40, and the spring member 50.

[0050] The syringe 10 includes a barrel 11, a gasket 12 that slides within the barrel 11 to discharge the stored medicinal liquid, a plunger 13, a disk-shaped plunger flange portion 14 provided on the rear end side of the plunger 13, and a puncture needle 15 attached to the tip of the barrel 11.

[0051] A barrel flange portion 11a is formed at the rear end of the barrel 11. The gasket 12 is made of butyl rubber, other elastomers, or soft resin packing that hermetically seals the gap between the barrel 11 and the plunger 13. A screw hole is provided at the rear end of the gasket 12 into which the male screw at the tip of the plunger 13 is screwed. The plunger flange portion 14 has a cylindrical projection 14a on the front surface that fits into a fitting recess of the ejector 40. Before use, the puncture needle 15 is protected by a cap 60.

[0052] The inner tube 20 is formed, for example, from a resin material into a hollow cylindrical shape, and is composed of an inner tube main body portion 20a on the tip side and an inner tube fixing portion 20b on the rear end side. The inner tube main body portion 20a on the tip side is formed so as to be insertable into the medium diameter portion 32 of the outer tube 30, and the inner tube fixing portion 20b on the rear end side is formed so as to be insertable into the large diameter portion 31 of the outer tube 30.

[0053] A pair of inner cylinder rocking pieces 21 are provided at a position close to the rear end side of the inner cylinder main body 20a of the inner cylinder 20. Each of the pair of inner cylinder rocking pieces 21 is formed by providing a pair of slits 21A in the side wall of the inner cylinder 20.

[0054] In addition, each of the pair of inner tube oscillating pieces 21 has an inner tube release portion 21B at its rear end, and its free end is extended to the inner tube fixing portion 20b and is formed so as to be bent outward, and an inner tube claw portion 21b having an inclined surface 21a that abuts against the ejector 40 is provided at its end.

[0055] Further, an inner tube locking portion 21c is provided on the outer circumferential surface of the inner tube swinging piece 21 adjacent to the front side of the inner tube release portion 21B with a gap therebetween, and is formed so as to bulge in the vertical direction away from the axis, and serves as a locking means for fitting into the first window portion 32b of the outer tube 30. The locking means locks the inner tube 20 in the use position where the puncture needle 15 protrudes from the front end of the outer tube 30 against the biasing force of the spring member 50.

[0056] The inner cylinder releasing portion 21B is formed so as to extend rearwardly inclined in a direction gradually away from the axis until it exceeds the outer diameter of the inner cylinder fixing portion 20b, and is formed so as to be housed in the outer cylinder 30 at the use position. The pair of inner cylinder swinging pieces 21 of the inner cylinder 20 are formed elastically deformable so that the inner cylinder locking portion 21c can be displaced between an engagement position and a disengagement position in order to perform the function of releasing the fixation between the inner cylinder 20 and the outer cylinder 30.

[0057] Further, a pair of return prevention pieces 22 are provided on the tip side of the inner cylinder 20 at positions collinear with the pair of inner cylinder swinging pieces 21 in the axial direction. Each of the pair of return prevention pieces 22 is formed by providing a pair of slits 22A (corresponding to the "second inner cylinder groove portion" in the present invention) in the wall on the tip side of the inner cylinder 20.

[0058] Each of the pair of return prevention pieces 22 is sandwiched by a pair of slits 22A and can swing up and down. A return prevention portion 22a is provided at the tip of the return prevention piece 22 in the forward and radially expanding direction. This return prevention portion 22a is provided at the front end of the return prevention piece 22 and extends forward at an angle in a direction gradually moving away from the axis to a position larger than the inner diameter of the medium diameter portion 32 and equal to or smaller than the outer diameter, and is formed so as to be able to engage with the inner surface on the front end side of the first window portion 32b.

[0059] The inclined end surface of the return prevention portion 22a has a recess 22b, which is formed so as to be able to fit into the first window portion 32b of the outer tube 30 and to be able to engage with the inner surface of the front end side of the first window portion 32b. The return prevention portions 22a of the pair of return prevention pieces 22 are elastically deformable when moving between a storage position where they fit into the second window portion 32c of the outer tube 30 and a return prevention position where they fit into the first window portion 32b of the outer tube 30. That is, when the rear end portion of the inner tube 20 comes out of the outer tube 30, the return prevention portions 22a of the pair of return prevention pieces 22 come out of the second window portion 32c of the outer tube 30A and fit into the first window portion 32b of the outer tube 30, thereby preventing the inner tube 20 from returning to the tip side.

[0060] In addition, a pair of anti-slip pieces 23 are provided at the tip side of the inner tube 20 at a position rotated 90 degrees relative to the pair of anti-return pieces 22, and each of the pair of anti-slip pieces 23 is formed by providing a pair of slits 23A in the wall at the tip side of the inner tube 20, and a anti-slip protrusion 23a is provided on the outer peripheral surface at the tip side.

[0061] This pair of anti-slip pieces 23 is configured so that when the rear end of the inner tube 20 comes out of the outer tube 30, the anti-slip protrusions 23a slide along a pair of slits 32a of the outer tube 30 and hook onto the outer tube step portion 34b located between the large diameter portion 31 and the medium diameter portion 32 of the outer tube 30, thereby preventing the inner tube 20 from coming out of the outer tube 30.

[0062] In addition, a pair of fitting parts 24 for fitting the barrel flange part 11a of the barrel 11 is provided on the inner cylinder fixing part 20b on the rear end side of the inner cylinder 20. The pair of fitting parts 24 are formed so that the rear end part of the inner cylinder 20 is bent into a U-shape when viewed in the up-down direction and is fitted to the outside of the barrel flange part 11a. Furthermore, a plurality of spring abutment ribs 25 for restricting the rear end of the spring member 50 are provided on the rear end side of the inner peripheral surface of the inner cylinder 20. The fitting parts 24 fix the barrel 11 to the inner cylinder 20. As a result, when the engagement of the pair of inner cylinder swing pieces 21 is released, the barrel 11 moves together with the inner cylinder 20.

[0063] The outer cylinder 30 is formed, for example, from a resin material into a three-stage hollow cylinder shape in which a large diameter section 31 (corresponding to the "outer cylinder large diameter section" in the present invention), a medium diameter section 32, and a small diameter section 33 are integrally formed. The large diameter section 31, the medium diameter section 32, and the small diameter section 33 are each formed into a cylindrical shape. The medium diameter section 32 and the small diameter section 33 correspond to the "outer cylinder main body" in the present invention.

[0064] The outer cylinder 30 is configured so that the rear end of the inner cylinder 20 and the ejector 40 can be stored inside the large diameter portion 31. The ejector 40 is slidably stored in the large diameter portion 31. The inner cylinder body portion 20a on the tip side of the inner cylinder 20 can be inserted inside the medium diameter portion 32, and a pair of slits 32a extending in the axial direction are provided at positions facing the side walls of the medium diameter portion 32.

[0065] The pair of slits 32a are formed so that the fall-prevention protrusions 23a of the pair of fall-prevention pieces 23 of the inner tube 20 can slide in them. In addition, a pair of first windows 32b into which the inner tube claws 21b of the pair of inner tube swing pieces 21 of the inner tube 20 fit are provided in the rear end side wall of the medium diameter section 32 at positions rotated 90 degrees with respect to the pair of slits 32a.

[0066] The pair of first windows 32b are adapted to receive the return prevention portions 22a of the pair of return prevention pieces 22 of the inner tube 20, thereby preventing the inner tube 20 from returning to the tip side. Furthermore, a second window 32c is provided in the tip side wall of the medium diameter section 32 at a position rotated 90 degrees with respect to the pair of slits 32a, into which the return prevention portions 22a of the pair of return prevention pieces 22 of the inner tube 20 are fitted.

[0067] As shown in FIG. 5, inside the outer cylinder step portion 34b between the large diameter portion 31 and the medium diameter portion 32, tapered portions 34c are provided at positions rotated 45 degrees with respect to the pair of slits 32a.

[0068] Furthermore, a flange portion 34 is provided at the outer cylinder step portion 34b between the large diameter portion 31 and the medium diameter portion 32 so that the user can grasp it. The flange portion 34 is a portion on which, for example, the index finger and middle finger are placed when the user presses the plunger flange portion 14 with the thumb.

[0069] The flange portion 34 has an elliptical outer shape with a flat portion 34d formed by linearly cutting out the minor diameter side of a plate-like body formed in a roughly elliptical disk shape, i.e., the side on which the removal prevention piece 23 is formed. By having such a linear flat portion 34d, it is possible to prevent the ejector 40 placed horizontally from unintentionally rolling.

[0070] The small diameter portion 33 is configured so as to be able to accommodate the puncture needle 15 therein.

[0071] The outer cylinder 30 may be made of, for example, a transparent or semi-transparent material through which light can pass. In this case, the liquid medicine inside the syringe 10 can be observed from the outside. That is, the syringe 1 with a safety device according to this embodiment allows the user to visually check the amount of liquid medicine inside the syringe 10 and the operating state of the gasket 12 during use.

[0072] The ejector 40 is formed in a substantially cylindrical shape from, for example, a resin material. The ejector 40 is cylindrical and extends forward from the periphery of the plunger flange portion 14 so as to be insertable into the gap between the outer tube 30 and the inner tube fixing portion 20b. The ejector 40 has an ejector release portion 41a at its front end which is insertable into the gap between the outer tube 30 and the inner tube release portion 21B.

[0073] An inclined guide portion 41b is formed so that the ejector release portion 41a can come into contact with a pair of inner cylinder swing pieces 21 of the inner cylinder 20. The inclined guide portion 41b is an inclined surface whose inner diameter gradually increases toward the front end (i.e., inclined backward from the outer diameter toward the inner diameter). A claw storage portion 41c is provided on the circumferential surface on the rear end side of the inclined guide portion 41b. A mold release undercut 41d is provided on the circumferential surface on the rear end side of the claw storage portion 41c.

[0074] As shown in FIG. 6, the rear end of the ejector 40 is provided with a plunger flange fitting portion 42 into which the plunger flange portion 14 can be fitted, and a fitting recess 43 into which the cylindrical projection 14a of the plunger flange portion 14 can be fitted.

[0075] By fitting the ejector 40 into the plunger flange portion 14, the ejector 40 and the plunger flange portion 14 can be integrated. The ejector 40 is configured such that, after the injection is completed, the ejector release portion 41a of the ejector 40 pushes and bends the pair of inner cylinder swing pieces 21 of the inner cylinder 20 when the ejector 40 is pushed by the plunger flange portion 14.

[0076] The spring member 50 is a compression coil spring made of an appropriate metal such as stainless steel. One end (front end) of the spring member 50 abuts against the front end of the medium diameter portion 32 of the outer cylinder 30, and the other end (rear end) abuts against the front ends of the spring abutment ribs 25 on the inner peripheral surface of the inner cylinder 20, and is disposed so as to urge the inner cylinder 20 backward and urge the outer cylinder 30 toward the front end side. The syringe 10 is inserted inside the spring member 50. In the initial state, the spring member 50 is compressed between the front end of the medium diameter portion 32 of the outer cylinder 30 and the spring abutment ribs 25 on the inner peripheral surface of the inner cylinder 20. That is, before use, the spring member 50 is located on the rear end side of the syringe 10.

[0077] The cap 60 has a double structure, for example, an outer cap made of hard resin such as polypropylene and an inner cap made of soft resin such as elastomer, and is a removable, approximately truncated cone-shaped cap that protects the puncture needle before use. When in use, the cap 60 is removed by the user before injection, for example, by holding the outer cylinder 30 with one hand and simply pulling it out with the other hand. Before use of this syringe 1 with a safety device, the cap 60 is attached to the syringe 10 as shown in FIG. 1A. When in use, the cap 60 is removed.

[0078] Hereinafter, the steps for assembling the safety syringe 1 of this embodiment will be described with reference to FIGS. 7A to 7E.

[0079] In the process of assembling the syringe 1 with a safety device, first, as shown in Fig. 7A, the spring member 50 is inserted into the inner cylinder 20 from the tip side of the inner cylinder 20. Next, as shown in Fig. 7B, the inner cylinder 20 with the spring member 50 inserted therein is inserted into the outer cylinder 30 from the large diameter portion 31 side to the medium diameter portion 32, and the spring member 50 is compressed, and the inner cylinder claw portions 21b of the pair of inner cylinder swing pieces 21 are fitted into the first window portions 32b of the outer cylinder 30, and the inner cylinder 20 is fixed to the outer cylinder 30. In this process, when the inner cylinder 20 is inserted from the large diameter portion 31 side of the outer cylinder 30, the inner cylinder 20 is rotated 45 degrees with respect to the outer cylinder 30, that is, the inner cylinder 20 is inserted in a state where the projections (the inner cylinder locking portion 21c, the return prevention portion 22a, and the slip-out prevention projection 23a) on the outer peripheral surface of the inner cylinder 20 and the tapered portion 34c in the outer cylinder 30 are aligned.

[0080] In this case, the protrusions on the outer surface of the inner tube 20 (inner tube claw portion 21b, inner tube locking portion 21c, return prevention portion 22a, and anti-slip protrusion 23a) are pushed inward by the tapered portion 34c, allowing it to be smoothly inserted into the medium diameter portion 32 of the outer tube 30.

[0081] When the inner tube 20 is rotated 45 degrees in the original direction after the inner tube body portion 20a of the inner tube 20 is inserted into the medium diameter portion 32 of the outer tube 30, the protrusions on the outer circumferential surface of the inner tube 20 (the inner tube locking portion 21c, the return prevention portion 22a, and the slip-out prevention protrusion 23a) enter the first window portion 32b, the second window portion 32c, and the slit 32a, respectively, and are fixed (positioned). The spring member 50 is locked in a compressed state.

[0082] 7D, the ejector 40 is attached to the plunger flange portion 14. In this step, the plunger flange portion fitting portion 42 of the ejector 40 is fitted into the plunger flange portion 14, and the ejector 40 and the plunger flange portion 14 are integrated together.

[0083] 7C, the syringe 10 filled with the drug solution is inserted from the rear end side of the inner cylinder 20, and the barrel flange portion 11a of the barrel 11 is fitted into the fitting portion 24 at the rear end of the inner cylinder 20. In this case, the tip of the puncture needle 15 (cap 60) is exposed from the tip of the small diameter portion 33 of the outer cylinder 30. The drug solution in the syringe 10 is sealed by the gasket 12.

[0084] Finally, as shown in Fig. 7E, the ejector 40 inserts the plunger 13 attached to the plunger flange portion 14 from the rear end of the barrel 11 and screws it into the gasket 12. This completes the assembly of the syringe 1 with a safety device, as shown in Fig. 1A. In this manner, the syringe 1 with a safety device can be easily assembled.

[0085] Next, the operating state of the syringe with a safety device 1 of this embodiment when in use will be described with reference to the drawings. Fig. 8 is a locally enlarged cross-sectional view showing a state in which the plunger flange portion 14 is pressed, the ejector 40 is actuated, and the inner cylinder locking portion 21c of the inner cylinder swinging piece 21 of the inner cylinder 20 is released, and Fig. 9 is a locally enlarged cross-sectional view showing a state in which the return prevention piece 22 of the syringe with a safety device 1 is in the return prevention position.

[0086] When using (injecting) the syringe 1 with a safety device, the cap 60 is first removed. Next, the user inserts the injection needle into the target injection site and presses the plunger flange portion 14 provided on the rear end side of the plunger 13, thereby injecting the medicinal liquid stored in the barrel 11. In this case, the ejector 40 moves together with the plunger flange portion 14.

[0087] When the plunger flange portion 14 is pressed upon completion of the injection, the inclined guide portion 41b on the tip side of the ejector 40 pushes and bends the pair of inner cylinder swing pieces 21 of the inner cylinder 20, and the pair of inner cylinder swing pieces 21 deform from the engaged position to the disengaged position (see FIG. 8). As a result, the fixation between the inner cylinder 20 and the outer cylinder 30 is released, and the syringe 10, inner cylinder 20, and ejector 40, which are fixed together, move backward relative to the outer cylinder 30, and the puncture needle 15 retracts into the inside of the small diameter portion 33 of the outer cylinder 30 (see FIGS. 4A and 4B).

[0088] In this case, the anti-return portions 22a of the pair of anti-return pieces 22 of the inner tube 20 change from a state in which they are fitted into the second window portion 32c on the tip side of the medium diameter portion 32 of the outer tube 30 (see Figure 3A) to a state in which they are fitted into the first window portion 32b on the rear end side of the medium diameter portion 32 of the outer tube 30 (see Figure 4B), and when the inner tube 20 attempts to return toward the tip side, as shown in Figure 9, the pair of anti-return pieces 22 of the inner tube 20 abut against the wall of the first window portion 32b of the outer tube 30, preventing the inner tube 20 from returning toward the tip side.

[0089] At the same time, the pair of anti-slip pieces 23 of the inner cylinder 20 are hooked onto the outer cylinder step portion 34b between the large diameter portion 31 and the medium diameter portion 32 of the outer cylinder 30, preventing the inner cylinder 20 from slipping out of the outer cylinder 30. This makes it possible to reliably prevent punctures by the puncture needle 15 after use and to re-use the syringe.

[0090] Next, the effects of the syringe with a safety device 1 according to this embodiment and the syringe safety device 2 attached to the syringe will be described.

[0091] In the syringe safety device 2 of this embodiment, the locking means locks the puncture needle 15 in the usage position by engaging the outer tube locking portion 34a of the outer tube 30 with the inner tube locking portion 21c provided on the inner tube oscillating piece 21 of the inner tube 20.

[0092] In contrast, the ejector 40 of the syringe with a safety device 1 of the first embodiment is cylindrical and extends forward from the periphery of the plunger flange portion 14 so as to be insertable into the gap between the outer cylinder 30 and the inner cylinder fixing portion 20b. Therefore, when the ejector 40 is displaced forward via the plunger, the ejector 40 passes through the gap between the outer cylinder 30 and the inner cylinder fixing portion 20b and is disposed behind the inner cylinder releasing portion 21B.

[0093] The ejector 40 has an ejector release portion 41a at its front end that can be inserted into the gap between the outer tube 30 and the inner tube release portion 21B, so that when the ejector 40 is displaced forward via the plunger 13, the ejector release portion 41a at its front end is pushed into the gap between the outer tube 30 and the inner tube release portion 21B, displacing the inner tube release portion 21B toward the axis.

[0094] Since the inner cylinder release portion 21B is provided on the inner cylinder swinging piece 21 which can swing up and down, when the inner cylinder release portion 21B is displaced toward the axis, the inner cylinder swinging piece 21 on which it is provided is displaced toward the axis. Since the inner cylinder locking portion 21c described above is also provided on the inner cylinder swinging piece 21, the inner cylinder locking portion 21c is also displaced toward the axis together with the inner cylinder release portion 21B and the inner cylinder swinging piece 21 by the advancement of the ejector 40. As a result, the inner cylinder locking portion 21c is separated from the outer cylinder locking portion 34a described above, and the locking by the locking means is released.

[0095] Therefore, according to the syringe with safety device 1 and the syringe safety device 2 of this embodiment, the ejector 40 is provided directly on the plunger 13, and the locking is released directly by the ejector 40, so that the locking of the locking means can be reliably released.

[0096] In the syringe safety device 2 of this embodiment, the ejector release portion 41a is formed with an inclined guide portion 41b whose inner diameter gradually increases toward the front end, so that when the ejector 40 is displaced forward, the inclined guide portion 41b can push down the inner cylinder release portion 21B while sliding it toward the axis. In particular, the inner cylinder claw portion 21b is formed in the inner cylinder release portion 21B so as to face the inclined guide portion 41b of the ejector release portion 41a, so that when the ejector 40 is displaced forward, the inclined guide portion 41b and the inner cylinder claw portion 21b can slide against each other to push down the inner cylinder release portion 21B toward the axis.

[0097] As a result, the inner tube rocking piece 21 provided with the inner tube release portion 21B can be pushed down together with the inner tube locking portion 21c provided thereon to separate it from the outer tube locking portion 34a, thereby releasing the locking by the locking means.

[0098] Therefore, according to the syringe safety device 2 of this embodiment, the locking of the locking means can be released more reliably. In addition, the inner cylinder release portion 21B pushed down by the inclined guide portion 41b is guided into the internal space of the ejector 40 by the inclined guide portion 41b which continues to advance, so that the ejector 40 and the plunger 13 are integrated with the inner cylinder 20 and the barrel 11.

[0099] Furthermore, the inner cylinder claw portion 21b pushed down by the inclined guide portion 41b is guided into the internal space of the ejector 40 by the inclined guide portion 41b which continues to advance, and is stored in the claw storage portion 41c provided adjacent to the rear of the inclined guide portion 41b.

[0100] Therefore, the ejector 40 and plunger 13 are more reliably integrated with the inner cylinder 20 and barrel 11, so that in the syringe safety device 2 of this embodiment, when the locking means is released, the ejector 40, plunger 13, inner cylinder 20 and barrel 11 are retracted together relative to the outer cylinder 30, and the puncture needle 15 can be reliably covered by the outer cylinder 30.

[0101] In the syringe safety device 2 of this embodiment, the outer cylinder 30 is connected to a cylindrical medium diameter portion 32 via a flange portion at the rear end of the medium diameter portion 32. The outer cylinder 30 has a cylindrical large diameter portion 31 having an outer diameter larger than that of the inner cylinder 20. The medium diameter portion 32 has an inner diameter equal to or larger than the outer diameter of the inner cylinder main body portion 20a and smaller than the outer diameter of the inner cylinder fixing portion 20b, and the large diameter portion 31 is large enough to slidably accommodate an ejector 40 having an outer diameter larger than that of the inner cylinder fixing portion 20b. Therefore, the outer cylinder 30 can accommodate the inner cylinder 20 inside by covering the tip side of the inner cylinder 20.

[0102] Furthermore, a first window portion 32b for accommodating the inner tube engaging portion 21c is formed at the rear end portion of the above-mentioned medium diameter portion 32. Therefore, when the outer tube 30 is placed over the inner tube 20, the inner tube engaging portion 21c of the inner tube 20 is accommodated in the first window portion 32b of the outer tube 30, whereby the inner tube 20 can be engaged with respect to the outer tube 30 against the biasing force of the spring member 50.

[0103] Furthermore, since the inner surface of the rear end side of the first window portion 32b to the rear end of the outer tube step portion 34b is positioned in the gap between the inner tube locking portion 21c and the inner tube release portion 21B in the usage position, by pushing the ejector 40 all the way toward the outer tube step portion 34b at the back (front end) of the large diameter portion 31 in one go, the inner tube locking portion 21c is pushed down and away from the outer tube locking portion 34a, thereby releasing the locking by the locking means.

[0104] Therefore, according to the syringe safety device 2 of the present embodiment, the locking of the locking means can be released more reliably.

[0105] In the syringe safety device 2 of this embodiment, the inner cylinder 20 is provided with a return prevention piece 22 that can swing up and down. This return prevention piece 22 is stored in the outer cylinder 30 at the use position by fitting the outer cylinder 30 onto the outside while pushing it down in a direction approaching the axis, but when the return prevention piece 22 is released and displaced rearward by the biasing force of the spring member 50 and retreats to the first window portion 32b of the outer cylinder 30, it elastically deforms and expands in the vertical direction so as to enter the internal space of the first window portion 32b.

[0106] Furthermore, a return prevention portion 22a is formed at the tip of this return prevention piece 22, which engages with the inner surface of the front end side of the first window portion 32b of the outer tube 30.Therefore, even if the inner tube 20 is advanced (displaced forward) relative to the outer tube 30 in an attempt to return the puncture needle 15 to the usage position again, the return prevention portion 22a of the inner tube 20 engages with the first window portion 32b of the outer tube 30, preventing further advancement.

[0107] Furthermore, in the syringe safety device 2 of this embodiment, since the return prevention piece 22 can be stored in the second window portion 32c in the use position, the return prevention piece 22 is not held in a state pressed down by the inner circumferential surface of the outer cylinder 30 from the time of assembly until use. This makes it possible to prevent the return prevention piece 22 from becoming difficult to elastically deform due to aging, and the return prevention portion 22a of the inner cylinder 20 can be reliably engaged with the first window portion 32b of the outer cylinder 30.

[0108] Furthermore, in the syringe safety device 2 of this embodiment, the inner surfaces of the return prevention portion 22a of the inner tube 20 and the front end side of the first window portion 32b of the outer tube 30, which collide when the inner tube 20 is advanced relative to the outer tube 30 to return the puncture needle 15 to the usage position again, are formed into a concave and convex shape, respectively, so that they can be fitted together, thereby more reliably preventing further advancement.

[0109] Therefore, according to the syringe safety device 2 of the present embodiment, it is possible to further prevent reuse of a syringe that has been used once, and also to prevent accidental contact with the puncture needle 15 after use.

[0110] In the syringe 1 with a safety device of this embodiment, the safety device can be easily attached to a ready-made syringe 10 (syringe).

[0111] Furthermore, when made of a transparent or translucent material, the spring member 50 is positioned at the rear end side of the syringe 10 before use, so that the medicinal liquid can be seen from outside the outer tube 30 even after the syringe 10 is assembled into the outer tube 30.

[0112] Furthermore, in the syringe 1 with safety device of this embodiment, the base end side of the cap 60 fits into and is attached to the tip of the outer tube 30. Therefore, when removing the cap 60 during use (injection), the tip of the outer tube 30 functions as a guide, allowing the cap 60 to be pulled out straight, reducing the risk of bending the puncture needle 15.

[0113] In addition, in the syringe 1 with a safety device of this embodiment, by integrating the ejector 40 and the plunger flange portion 14, the large diameter portion 31 of the outer cylinder 30 can be shortened, and therefore the overall length of the outer cylinder 30 can be shortened and the amount of waste can be reduced. In addition, the visible area of ​​the barrel 11 can be expanded, and the medicinal liquid can be easily confirmed from the outside of the outer cylinder 30.

[0114] Furthermore, in the syringe 1 with safety device of this embodiment, a claw storage portion 41c is provided on the circumferential surface at the rear end side of the inclined guide portion 41b of the ejector 40, so that when the inner tube locking portions 21c of the pair of inner tube oscillating pieces 21 of the inner tube 20 are released, the inner tube claw portions 21b of the pair of inner tube oscillating pieces 21 advance, providing a clicking sensation.

[0115] Below, we will explain the finger clip 70 that is attached to a syringe with a safety device 1 and a syringe safety device 2 that is attached to the syringe according to the second embodiment of the present invention (hereinafter, only the syringe with a safety device 1 will be referred to as a representative of these).

[0116] Figures 10 to 14 show the configuration of the finger clip 70 of this embodiment. Figure 10 is a front view showing the configuration of the finger clip 70, Figure 11 is a plan view showing the configuration of the finger clip 70, Figure 12 is a cross-sectional view taken along the line CC in Figure 11, Figure 13 is a front view showing how the finger clip 70 is attached to the syringe with a safety device 1, and Figure 14 is a rear perspective view showing the syringe with a safety device 1 with the finger clip 70 attached.

[0117] 13 is defined as the upper and lower sides of the finger clip 70. The upper side is the proximal end side where the plunger 13 and the plunger flange portion 14 are arranged, and the lower side is the distal end side where the puncture needle 15 and the cap 60 are arranged.

[0118] As shown in Figures 13 and 14, the finger clip 70 of this embodiment has an outer shape that resembles an arch when viewed from the front and an ellipse when viewed from above, and has a through hole in the center through which the syringe 1 with a safety device is inserted.

[0119] Finger clip 70 is formed of finger flanges that jut out like wings on both ends of the long axis side of an ellipse when viewed from above, and a central body portion having a through hole. Finger flange bottom portion 74 and body bottom portion 76 that form the bottom surface are formed on the finger flange and body portion, respectively. The outer bottom surface formed by finger flange bottom portion 74 and body bottom portion 76 is where the user's fingers, such as the index finger and middle finger, are hooked when finger clip 70 is used.

[0120] A plurality of, for example, three, horizontal ribs 74a are formed on each of the pair of finger flange bottoms 74 in the short direction of the finger clip 70, so that the fingers are less likely to slip even when force is applied during use.

[0121] A mounting cylindrical portion 72 is formed around the barrel through-hole so as to extend downward from the underside of the barrel bottom portion 76. An inner peripheral surface 721 of the mounting cylindrical portion 72 is a portion that comes into contact with the outer peripheral surface of the medium diameter portion 32 of the outer barrel 30 when the mounting cylindrical portion 72 is mounted on the safety-equipped syringe 1. As shown in Figs. 11 and 12, a pair of relief recesses 722 for avoiding interference with the slip-out prevention protrusions 23a, and a pair of relief recesses 723 for avoiding interference with the return prevention portion 22a are formed on the inner peripheral surface 721 of the mounting cylindrical portion 72.

[0122] A barrel reinforcing rib 75 is provided on the barrel so as to extend upward from the barrel bottom 76. The barrel reinforcing rib 75 is composed of a linear wall rib 75b forming the barrel side surface and an annular rib 75a provided so as to surround the outer periphery of the mounting cylindrical portion 72. The flange portion 34 of the syringe 1 with a safety device is housed and mounted in a barrel internal space 77 formed by the wall rib 75b and the annular rib 75a.

[0123] For this reason, the size of the ellipse bordered by the inner surfaces of the wall rib 75b and the annular rib 75a corresponds to the outer periphery of the flange portion 34, but the inner surface of the annular rib 75a is slightly larger, and the wall rib 75b is positioned away from the flange portion 34 by the size (height) of the guide rib 752 described later.

[0124] A bottom reinforcement rib 73c having an L-shape in plan view is formed on the body bottom 76, extending from the annular rib 75a to the mounting cylindrical portion 72 around the through hole. One end of the bottom reinforcement rib 73c is connected to the joint between the wall rib 75b and the annular rib 75a, and the other end is connected shifted from the center of the annular rib 75a toward the wall rib 75b to which the one end is connected.

[0125] On the inner peripheral surface of the annular rib 75a, a pair of rib fitting protrusions 751 for contacting and fixing to the base end side surface of the flange portion 34 of the stored syringe with safety device 1 are formed on each of the left and right annular ribs 75a in an upper and lower direction. On the wall rib 75b, a pair of guide ribs 752 for guiding the flat portion 34d of the flange portion 34 is formed on each of the wall ribs 75b in the upper and lower direction.

[0126] The flange portion 34 of the safety syringe 1 is housed and attached in the barrel internal space 77, with the lower surface (tip side surface) of the flange portion 34 abutting against the bottom reinforcing rib 73c and the outer periphery of the upper surface (base side surface) being located below the fitting convex portion 751. In other words, the flange portion 34 is sandwiched between the bottom reinforcing rib 73c and the fitting convex portion 751.

[0127] A pair of flange reinforcement ribs 73b extend from the points where the bottom reinforcement rib 73c of the annular rib 75a is joined toward the left and right ends, and follow the outer shape of the finger flanges while narrowing the gap therebetween.

[0128] A finger flange rib 73a is formed on the outer periphery of the finger flange and is connected to the wall rib 75b. A V-shaped flange reinforcement rib 73b extends from the middle of the finger flange rib 73a with a slight gap between them and is connected to the finger flange rib 73a.

[0129] Since the upper portion and base end side of the finger clip 70 are formed by the above-mentioned ribs, shrinkage caused by the thickness of the material is prevented.

[0130] Next, a method for attaching the finger clip 70 of this embodiment to the safety syringe 1 will be described.

[0131] First, as shown in FIG. 13, the upper base end side of the finger clip 70 is placed opposite the tip end side of the safety syringe 1.

[0132] Next, the finger clip 70 is moved so as to slide on the barrel 30 toward the base end side of the safety syringe 1. At this time, the barrel 30 enters the barrel through-hole via the barrel internal space 77.

[0133] When the finger clip 70 is further moved toward the base end, the flange 34 enters the body internal space 77, climbs over the fitting protrusion 751, and comes into contact with the bottom reinforcing rib 73c.

[0134] As a result, the finger clip 70 is fixed to the safety syringe 1, resulting in the state shown in FIG.

[0135] Next, a modification of the finger clip 70 of this embodiment will be described.

[0136] In the above embodiment, an example was shown and described in which four mating protrusions 751 are evenly arranged, but the present invention is not limited to this, and any number of two or more may be formed, and may be continuous in a ring shape.

[0137] In the above embodiment, an example in which the guide ribs 752 are formed in four locations has been described, but the present invention is not limited to this, and any number of guide ribs may be formed as long as it is two or more locations.

[0138] The present invention is not limited to the above-described embodiments, and its technical scope includes various modified forms of design within the scope that does not deviate from the gist of the invention described in the claims. [Explanation of symbols]

[0139] 1 Syringe with safety mechanism 2 Syringe safety device 10 Syringe 11 Barrel 11a Barrel flange portion 12 Gasket 13 Plunger 14 Plunger flange portion 14a Cylindrical projection 15 Puncture needle 20 Inner tube 20a Inner tube main body portion 20b Inner tube fixing portion 21 Inner tube swing piece 21A Slit (first inner tube groove portion) 21a Inclined surface 21B Inner tube release portion 21b Inner tube claw portion 21c Inner tube locking portion 22 Return prevention piece 22A Slit (second inner tube groove portion) 22a Return prevention portion 22b Recess 23 Pull-out prevention piece 23A Slit 23a Pull-out prevention projection 24 Fitting portion 25 Spring abutment rib 30 Outer tube 31 Large diameter portion (outer tube large diameter portion) 32 Medium diameter portion (outer tube main body portion) 32a Slit 32b First window portion 32c Second window portion 33, small diameter portion 34, flange portion 34a, outer cylinder locking portion 34b, outer cylinder step portion 34c, tapered portion 40, ejector 41a, ejector release portion 41b, inclined guide portion 41c, claw storage portion 41d, undercut for mold release 42, plunger flange portion fitting portion 43, fitting recess 50, spring member 60, cap 70, finger clip

Claims

1. a syringe safety device attached to a syringe including: a barrel having a puncture needle at a front end and a barrel flange portion at a rear end, the barrel containing a medicinal solution; and a plunger whose front end is slidably inserted from the rear end side of the barrel and has a plunger flange portion at its rear end, wherein when a direction along the axis of the puncture needle is defined as a front-rear direction, a first direction perpendicular to the front-rear direction is defined as a top-bottom direction, and a second direction perpendicular to the front-rear direction and the top-bottom direction is defined as a left-right direction, the syringe safety device comprises: an inner tube which is cylindrical and fitted to the outside of the barrel and fixed to the barrel flange portion; an outer tube which is cylindrical and capable of housing the puncture needle by being fitted to the outside of the barrel and the inner tube, and which is slidable along the outer peripheral surface of the barrel; a spring member built into the outer tube and which biases the inner tube rearward relative to the outer tube; and a locking means which locks the inner tube in a use position where the puncture needle protrudes from the front end of the outer tube against the biasing force of the spring member; and an ejector that releases the locking by the locking means, wherein the inner cylinder is provided at a rear end thereof and has an inner cylinder fixing portion that is fitted onto the outside of the barrel flange portion, and a pair of inner cylinder swinging pieces that extend rearward from the outer peripheral surface of the inner cylinder until they exceed the outer diameter of the inner cylinder fixing portion and are swingable up and down, the ejector is tubular extending forward from the periphery of the plunger flange portion and insertable into a gap between the outer cylinder and the inner cylinder fixing portion, and has an ejector release portion at its front end that is insertable into the gap between the outer cylinder and the inner cylinder swinging piece, the locking means being configured to be lockable in a use position when the inner cylinder swinging piece is engaged with the outer cylinder, and when the plunger and the ejector release portion are displaced forward, the ejector release portion is pushed into the gap between the outer cylinder and the inner cylinder swinging piece and the inner cylinder swinging piece is displaced in a direction approaching the axis, thereby releasing the locking.

2. a syringe safety device attached to a syringe including: a barrel having a puncture needle at a front end and a barrel flange portion at a rear end, the barrel containing a medicinal solution; and a plunger whose front end is slidably inserted from the rear end side of the barrel and has a plunger flange portion at its rear end, wherein when a direction along the axis of the puncture needle is defined as a front-rear direction, a first direction perpendicular to the front-rear direction is defined as a top-bottom direction, and a second direction perpendicular to the front-rear direction and the top-bottom direction is defined as a left-right direction, the syringe safety device comprises: an inner tube which is cylindrical and fitted to the outside of the barrel and fixed to the barrel flange portion; an outer tube which is cylindrical and capable of housing the puncture needle by being fitted to the outside of the barrel and the inner tube, and which is slidable along the outer peripheral surface of the barrel; a spring member built into the outer tube and which biases the inner tube rearward relative to the outer tube; and a locking means which locks the inner tube in a use position where the puncture needle protrudes from the front end of the outer tube against the biasing force of the spring member; and an ejector for releasing the locking by the locking means, wherein the inner tube has a cylindrical inner tube main body, a pair of inner tube fixing parts extending rearward from the left and right ends of the rear end of the inner tube main body, the rear ends of which are bent in a U-shape when viewed in the vertical direction and fitted to the outside of the barrel flange part, a pair of inner tube swinging pieces extending rearward from the vertical ends of the rear end of the inner tube main body to a position forward of the front end of the barrel flange part with a circumferential gap from each of the pair of inner tube fixing parts and swingable in the vertical direction, an inner tube releasing part provided at the rear end of the inner tube swinging piece, and an inner tube locking part provided adjacent to the inner tube releasing part of the inner tube swinging piece with a gap on the front side thereof and bulging in the vertical direction away from the axis, wherein the inner tube releasing part is gradually inclined rearward in the direction away from the axis and extends until it exceeds the outer diameter of the inner tube fixing part, and is stored in the outer tube at the usage position, The ejector is cylindrical and extends forward from the periphery of the plunger flange portion so as to be insertable into the gap between the outer tube and the inner tube fixing portion, and has an ejector releasing portion at its front end which can be inserted into the gap between the outer tube and the inner tube releasing portion; the outer tube has an outer tube locking portion which extends from the vertical end of its inner circumferential surface in a direction approaching the axis and which is disposed in the gap between the inner tube locking portion and the inner tube releasing portion when in the use position; and the locking means isthe outer tube is fitted onto the outside of the inner tube from the front end side toward the rear, and the rear end of the inner tube locking portion engages with the front end of the outer tube locking portion, thereby allowing the outer tube to be locked at the usage position; and the plunger and the ejector release portion are displaced forward, causing the ejector release portion to be pushed into a gap between the outer tube and the inner tube releasing portion, thereby displacing the inner tube releasing portion and the inner tube rocking piece including the inner tube releasing portion in a direction approaching the axis, and the inner tube locking portion provided on the inner tube rocking piece is separated from the outer tube locking portion, thereby releasing the lock.

3. 3. The syringe safety device according to claim 2, wherein the ejector release portion is formed with an inclined guide portion whose inner diameter gradually increases toward the front end.

4. 4. The syringe safety device according to claim 3, wherein the inner cylinder release portion is provided at a rear end thereof and has an inner cylinder claw portion that is convex in a direction away from the axis along the vertical direction, and the ejector release portion has a claw storage portion that is provided adjacent to the rear of the inclined guide portion and is formed concave in a direction away from the axis along the vertical direction, and is capable of storing the inner cylinder claw portion.

5. 3. The syringe safety device according to claim 2, wherein the outer barrel has a cylindrical outer barrel main body having an inner diameter equal to or greater than an outer diameter of the inner barrel main body and less than an outer diameter of the inner barrel fixing portion, and an outer barrel large diameter portion connected to a rear end of the outer barrel main body via an outer barrel step portion, having a cylindrical outer diameter larger than that of the outer barrel main body, and slidably housing the ejector, wherein a first window portion is formed at a vertical end of the rear end of the outer barrel main body that penetrates the outer barrel main body in the vertical direction and houses the inner barrel locking portion in the use position, the outer barrel locking portion is constituted by an inner surface on the rear end side of the first window portion, and a portion from the inner surface on the rear end side of the first window portion to the rear end of the outer barrel step portion is configured to be positioned in a gap between the inner barrel locking portion and the inner barrel releasing portion in the use position.

6. 6. The syringe safety device according to claim 5, wherein the inner barrel main body portion has a pair of second inner barrel groove portions extending rearward from its front end along an extension line of a side edge of the inner barrel swinging piece, a return prevention piece sandwiched between the pair of second inner barrel groove portions and swingable up and down, and a return prevention portion provided at the front end of the return prevention piece and extending forward and inclined in a direction gradually away from the axis to a position larger than the inner diameter of the outer barrel main body portion and equal to or smaller than the outer diameter, the return prevention portion engaging with an inner surface on the front end side of the first window portion, wherein the return prevention portion is housed in the outer barrel at the usage position by fitting the outer barrel to the outside while pressing down the return prevention piece in a direction approaching the axis, and when the locking is released, is displaced rearward with respect to the outer barrel by the biasing force of the spring member to a position where it is housed in the first window portion.

7. 7. The syringe safety device according to claim 6, wherein the outer barrel body is provided with a second window portion at a position facing the return prevention portion in the use position, the second window portion penetrating the outer barrel body in the vertical direction and accommodating the return prevention portion.

8. 8. The syringe safety device according to claim 7, wherein the front end surface of the return prevention portion is formed concavely toward the rear when viewed in the left-right direction, and the inner surface of the front end side of the first window portion is formed convexly toward the rear when viewed in the left-right direction, and is capable of engaging with the return prevention portion.

9. A syringe with a safety device, comprising: the syringe; and the syringe safety device according to any one of claims 1 to 8 attached to the syringe.

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