TW202027805A - A syringe and an auxiliary dosing device for the syringe - Google Patents

Abstract

The present application relates to syringes and auxiliary dosing devices for syringes. An auxiliary dosing device for a syringe includes a plunger rod having a proximal end and a distal end; and a dosing snap ring sleeving the outer periphery of the plunger rod and moving along the axial direction of the plunger rod. The dosing snap ring is configured to be circumferentially rotatable relative to the plunger rod from a first position to a second position. As the dosing snap ring is circumferentially rotated from the first position to the second position, the plunger rod is capable of moving a distance in an axial direction relative to the meter snap ring in a distal direction.

Description

Syringe and auxiliary dosing device for syringe

This application relates to syringes, and more specifically to auxiliary dosing devices for syringes.

Conventional syringes are usually equipped with a dose marking line on the barrel. When in use, medical staff can visually observe the distal end of the plunger to align with the corresponding dose marking line on the barrel before and after injection to provide the patient with the required injection dose. However, due to the influence of factors such as the viewing angle, light intensity, etc., it is difficult for medical staff to accurately position the distal end of the plunger and align it with the corresponding dose marking line, resulting in inaccurate injection dose. Especially for small-volume syringes, such as ophthalmic syringes, where the required injection dose is usually only about 0.1ml or less, but the minimum dose marking line of conventional syringes is 0.1ml, which cannot be achieved by eye control alone. dose. In view of the fact that traditional syringes cannot achieve precise injections, especially small doses, there is an urgent need in the art for a syringe and an auxiliary quantitative device that can accurately control the injection dose.

In view of the problems in the prior art, one of the objectives of the present invention is to provide a new type of auxiliary dosing device and a syringe containing the auxiliary dosing device, which does not require medical staff to visually check the dose, thereby avoiding visual errors. In addition, the syringe of the present invention can accurately control the injection dose, and can realize the injection dose of the pre-filled syringe less than 0.1 ml.

According to one aspect of the present application, there is provided an auxiliary dosing device for a syringe, which includes: a plunger rod having a proximal end and a distal end; and a plunger rod sleeved on the periphery of the plunger rod and able to follow the plunger rod shaft To move the dose snap ring. The metering snap ring is configured to be able to rotate circumferentially from a first position to a second position relative to the plunger rod. When the metering snap ring rotates circumferentially from the first position to the second position, the plunger rod can move a distance in the distal direction relative to the metering snap ring in the axial direction.

According to another aspect of the present application, a syringe is provided, the syringe includes: a syringe; a plunger slidably disposed in the syringe; and an auxiliary dosing device. The auxiliary dosing device includes: a plunger rod having a proximal end and a distal end; and a dose snap ring sleeved on the outer circumference of the plunger rod and capable of moving axially along the plunger rod. The metering snap ring is configured to be able to rotate circumferentially from a first position to a second position relative to the plunger rod. When the metering snap ring rotates circumferentially from the first position to the second position, the plunger rod can move a distance in the distal direction relative to the metering snap ring in the axial direction.

Other aspects of the present invention will become apparent by considering the detailed description and drawings.

FIG. 1a shows an exploded view of a syringe 10 according to an embodiment of the present invention, where the syringe 10 includes an auxiliary metering device 100, a booster 200, a syringe 300, and a plunger 400. In the illustrated embodiment, the auxiliary quantitative device 100 includes a plunger rod 102 and a metering snap ring 104 sleeved on the periphery of the plunger rod 102 and capable of sliding along the plunger rod axial direction. The syringe 300 includes a substantially cylindrical barrel portion 301, a needle mounting portion for mounting an injection needle (not shown) is provided at the distal end of the barrel portion 301, and a radially outwardly extending portion is provided at the proximal end of the barrel portion 301 Flange 302. The booster 200 includes a fixing groove 203 that can engage the flange 302 so that the booster 200 is mounted to the syringe 300.

Figure 1b shows the syringe 10 of Figure 1a in an assembled state. As shown in Fig. 1b, after assembly, the plunger rod 102 of the auxiliary dosing device 100 is combined with the plunger 400, and both can be accommodated in the inner cavity of the syringe 300 and slide therein.

2a and 2b respectively show a front view and a cross-sectional view of the plunger rod 102 according to an embodiment of the present invention. As shown in FIG. 2a, the plunger rod 102 includes a proximal end 110 and a distal end 111. In the present application, the proximal end refers to the end close to the user of the syringe in the use state, and the distal end refers to the end far away from the user of the syringe in the use state. In one embodiment, the plunger rod 102 includes a pushing portion 112 at the proximal end 110 and four longitudinal ribs 117 extending from the pushing portion 112 to the distal end 111. As shown in Figures 1a and 2a, the four longitudinal ribs 117 are arranged radially, and as shown in Figure 2b, the cross-sections of the four longitudinal ribs 117 are roughly cross-shaped, connecting the four outermost ends of the four longitudinal ribs 117 The dots can form a square. Although FIGS. 1a and 2a only show three longitudinal edges, those skilled in the art can understand that the back of the plunger rod 102 also has a fourth longitudinal edge 117.

Continuing to refer to FIGS. 2 a and 2 b, the plunger rod 102 further includes a shoulder 113 adjacent to the pushing portion 112 and protruding radially outward from the longitudinal rib 117, and the shoulder 113 has a shoulder surface 114 facing the distal end 111. The plunger rod 102 further includes four positioning protrusions 115, each positioning protrusion 115 is located on the distal side of the four shoulders 113 and respectively extends radially from the four longitudinal edges 117. In an embodiment, the proximal end of the positioning protrusion 115 extends from the shoulder surface 114, and the height of the positioning protrusion 115 radially outward from the longitudinal rib 117 is less than that of the shoulder 113 radially outward from the longitudinal rib 117 Prominent height. It can be understood that this embodiment only exemplarily shows four longitudinal edges, four shoulders and four positioning protrusions. Those skilled in the art can adjust the longitudinal edges, shoulders and positioning protrusions according to actual needs. Quantity (for example, more or less). For example, the plunger rod 102 may also have three longitudinal ribs arranged radially, and three shoulders and three positioning protrusions corresponding to the three longitudinal ribs. Alternatively, the plunger rod 102 may also have five longitudinal ribs distributed radially, and five shoulders and five positioning protrusions corresponding to the five longitudinal ribs. In addition, the number of longitudinal ribs, shoulders and positioning protrusions can be different. For example, the plunger rod 102 may have four longitudinal edges as shown in Figures 2a and 2b, but only have two shoulders and two positioning protrusions on opposite sides. Therefore, the present application does not limit the specific number of longitudinal edges, shoulders and positioning protrusions of the plunger rod 102.

As shown in FIG. 2a, the plunger rod 102 further includes a cylindrical protrusion 119 at the distal end 111, and the shape and size of the cylindrical protrusion 119 are set to be able to be inserted into the central hole of the plunger 400. In an embodiment, the plunger 400 may be made of an elastic material. In an embodiment, the diameter of the cylindrical protrusion 119 is equal to or slightly larger than the diameter of the central hole of the plunger 400, so that the cylindrical protrusion 119 forms a tight fit with the central hole of the plunger 400, so that the plunger 400 can follow The columnar protrusion 119 moves axially together. In another embodiment, the diameter of the cylindrical protrusion 119 is slightly smaller than the diameter of the central hole of the plunger 400, that is, the cylindrical protrusion 119 forms a loose fit with the central hole of the plunger 400, so that the When the barrel 300 pulls the plunger rod 102 toward the proximal end, the plunger 400 will not move toward the proximal end along with the plunger rod 102, thereby preventing the medical staff from accidentally sucking air into the syringe 300 due to misoperation. In an embodiment, the height of the cylindrical protrusion 119 is greater than the height of the plunger 400, so that when the cylindrical protrusion 119 is inserted into the plunger 400, the distal end of the cylindrical protrusion 119 extends beyond the plunger 400, As a result, the plunger 400 has greater rigidity over the entire length. When the plunger rod 102 and the plunger 400 are pushed distally relative to the barrel 300, this configuration can prevent the friction between the outer surface of the plunger 400 and the inner surface of the barrel 300 from causing deformation of the plunger 400, causing Measurement deviation.

In addition, the plunger rod 102 may further include an elastic pawl 116 and a shoulder 118, the features of which will be described in detail below.

Referring now to FIGS. 3a and 3b, FIGS. 3a and 3b respectively show a perspective view and a longitudinal sectional view of a metering snap ring 104 according to an embodiment of the present invention. As shown in Fig. 3a, the metering snap ring 104 is generally cylindrical and has an inner surface and an outer surface. As shown in the figure, the outer surface of the metering snap ring 104 may have a groove 127, which can increase the friction between the operator's finger and the metering snap ring 104. However, those skilled in the art can understand that in other embodiments, the outer surface of the metering snap ring 104 may have other structures that increase friction. For example, the outer surface of the metering snap ring can be provided with protrusions that increase friction, or the outer surface of the metering snap ring can be sprayed as a frosted surface to increase friction. The outer surface of the metering snap ring 104 may also be configured as a polygonal prism surface (for example, a hexagonal prism surface, an octagonal prism surface, etc.), or other regular or irregular cylindrical forms. In some embodiments, the outer surface of the metering snap ring 104 may also be smooth.

Continuing to refer to 3a, the metering clasp 104 includes a first end surface 121 at the proximal end, a second end surface 129 at the distal end, and a metering boss 122 protruding from the first end surface 121 toward the proximal end. In an embodiment, the metering boss 122 includes a boss surface 123 facing the proximal end. The embodiment of FIG. 3a schematically shows four metering bosses 122 to match the four shoulders 113 and positioning protrusions 115 of the plunger rod 102 shown in FIG. 2a. It is understood that those skilled in the art can adjust the number of metering bosses 122 according to the number of shoulders 113 and positioning protrusions 115. For example, when there are only two shoulders 113 and two positioning protrusions 115, the number of metering protrusions 122 may be only two.

Continuing to refer to FIGS. 2a and 3a, the metering snap ring 104 can be sleeved on the outer circumference of the plunger rod 102 and can slide along the plunger rod 102 axially. As shown in FIG. 3a, the metering snap ring 104 further includes a positioning groove 124 provided on its inner surface. The positioning groove 124 is aligned with the metering boss 122 and extends a distance from the boss surface 123 to the distal end in the axial direction. When the metering snap ring 104 slides along the plunger rod 102 to a position close to the proximal end of the plunger rod 102, the positioning groove 124 of the metering snap ring 104 can accommodate the positioning protrusion 115 of the plunger rod 102, so that the positioning protrusion 115 It can slide in the positioning groove 124. The boss surface 123 of the metering snap ring 104 can abut the shoulder surface 114 of the plunger rod 102 to prevent the metering snap ring 104 from further axially moving proximally relative to the plunger rod 102.

As shown in FIG. 2a, the plunger rod 102 further includes an elastic pawl 116, which protrudes outward from the outer peripheral surface of the plunger rod 102 and is configured to be pressed radially inwardly by an external force. FIG. 2a shows two elastic pawls 116, and the two elastic pawls 116 are arranged on two opposite longitudinal ribs 117 among the four longitudinal ribs 117 and are located close to the distal end of the positioning protrusion 115. It can be understood that the number of elastic pawls 116 (for example, one, three or four elastic pawls, etc.) can be adjusted accordingly according to actual needs.

Correspondingly, as shown in FIG. 3b, the metering clasp 104 includes a positioning joint at its distal end. In the illustrated embodiment, the positioning joint is configured as an anti-regressive cavity 126. The inner diameter of the anti-regressive cavity 126 is greater than the inner diameter of the proximal end portion of the metering snap ring 104. A ring-shaped shoulder 128 is provided in between. When the metering snap ring 104 sleeved on the plunger rod 102 slides from the distal end 111 of the plunger rod 102 to the proximal end 110 to the position of the elastic pawl 116, the inner surface of the proximal part of the metering snap ring 104 first contacts Go to the elastic pawl 116 and press the elastic pawl 116 inward to make it elastically deform and abut against the inner surface. When the metering snap ring 104 continues to slide toward the proximal end, the elastic pawl 116 enters the anti-retreat cavity 126. As the inner diameter of the anti-retreat cavity 126 increases, the elastic pawl 116 returns to its original shape under the action of elastic force. In this state, if an attempt is made to slide the metering snap ring 104 toward the distal end, the elastic pawl 116 will abut on the shoulder 128 of the metering snap ring 104, thereby preventing the metering snap ring 104 from moving toward the distal end. It can be understood that the axial distance from the shoulder 128 to the boss surface 123 is smaller than the distance from the elastic pawl 116 to the shoulder surface 114.

4 shows the auxiliary dosing device 100 in an assembled state according to an embodiment of the present invention, in which the metering boss 122 of the metering snap ring 104 abuts the shoulder surface 114 of the plunger rod 102, and the plunger rod The positioning protrusion 115 of the 102 is located in the positioning groove 124 of the metering snap ring 104. It can be understood that when the auxiliary dosing device 100 is placed vertically, the metering snap ring 104 will fall due to gravity until the elastic pawl 116 abuts the shoulder 128 of the metering snap ring 104. In addition, in an embodiment, when the elastic pawl 116 abuts the shoulder 128, the metering snap ring 104 is located farthest from the proximal end of the plunger rod. At this time, the positioning groove 124 of the metering snap ring 104 still accommodates A part of the positioning protrusion 115 of the plunger rod 102. In other words, in a certain embodiment, the axial distance from the shoulder 128 to the boss surface 123 is greater than the distance from the elastic pawl 116 to the distal end of the positioning protrusion 115. This arrangement enables the positioning groove 124 of the metering snap ring 104 to always accommodate a part of the positioning protrusion 115 of the plunger rod 102 without causing the positioning groove 124 to be separated from the positioning protrusion 115.

3a and 3b, the metering snap ring 104 also includes a safety groove 125 provided on its inner surface. The safety groove 125 is offset from the positioning groove 124 in the circumferential direction of the inner surface, and is configured to allow the positioning protrusion 115 Sliding axially in it. In an embodiment, the positioning protrusion 115 of the plunger rod 102 is elastic, and when the positioning protrusion 115 is located in the positioning groove 124, the positioning snap ring 104 can be rotated relative to the plunger rod 102. The positioning protrusion 115 is elastically deformed to escape from the positioning groove 124 and move into the safety groove 125.

As shown in FIG. 4, the boss surface 123 of the metering snap ring 104 abuts the shoulder surface 114 of the plunger rod 102 and the positioning protrusion 115 is located in the positioning groove 124. It can be understood that the metering snap ring 104 cannot face further The proximal end of the plunger rod 102 moves, in other words, the plunger rod 102 cannot move further toward the distal direction. When the metering snap ring 104 is rotated to engage the positioning protrusion 115 into the safety groove 125, the boss surface 123 of the metering snap ring 104 no longer abuts the shoulder surface 114 of the plunger rod 102, thereby allowing the metering snap ring 104 relative to the plunger rod 102 continues to move axially toward the proximal end for a distance D (as shown in FIG. 4), or the plunger rod 102 moves toward the distal direction by a distance D until the first end surface 121 of the metering snap ring 104 Abut the shoulder surface 114 of the plunger rod 102. It can be understood that the distance D is equal to the height H of the metering boss 122 in the axial direction (as shown in FIG. 4).

Referring now to FIGS. 5a to 5c, FIGS. 5a to 5c show a perspective view, a top view and a front view of the booster 200, respectively. As shown in FIG. 5a, the booster 200 includes a main body 201 and wings 202 extending from the main body 201 to both sides. As shown in FIGS. 5a-5c, the main body 201 of the booster 200 further includes a first sheet 204, a second sheet 205, and a connecting wall connecting the first sheet 204 and the second sheet 205. The first piece 204, the second piece 205 and the connecting wall define a groove 203, and the groove 203 can receive the flange 302 of the syringe 300 so that the booster 200 can be installed to the syringe 300. In addition, the first sheet 204 defines a first opening 206, and the second sheet 205 defines a second opening 207. 1a and 1b, when the booster 200 is installed on the syringe 300, the first piece 204 of the main body portion 201 is located on the upper part of the flange 302 of the barrel 300, and the second piece 205 of the main body portion 201 is located The lower part of the flange 302 of the syringe 300 and the second opening 207 of the second sheet body 205 engage the cylindrical portion 301 of the syringe 300.

FIG. 5d shows a cross-sectional view of the plunger rod 102 when installed in the booster 200. As shown in FIG. 5d, the shape and size of the first opening 206 are set to correspond to the plunger rod 102 and allow the plunger rod 102 to slide axially in the first opening 206. As described above, when viewed from the cross section of the plunger rod 102, the cross section formed by the four longitudinal ribs 117 is roughly cross-shaped, and the four outermost end points connecting the four longitudinal ribs 117 can form a square. As shown in FIG. 5d, the first opening 206 has a substantially square portion, and the substantially square portion corresponds to a square (dotted line portion) formed by connecting the four outermost end points of the four longitudinal ribs 117. This configuration can prevent the plunger rod 102 from rotating circumferentially relative to the first opening 206. As shown in FIG. 5d, when the plunger rod 102 axially slides in the first opening 206, the substantially square portion of the first opening 206 is matched with the longitudinal edge 117 of the plunger rod 102 to prevent the plunger rod 102 from turning around. To rotate. It can be understood that the number of longitudinal ribs 117 can be more or less than four, and the shape formed by connecting the outermost end points of the longitudinal ribs 117 can also be a rectangle or other polygons (for example, triangles, pentagons, or hexagons). Shape, etc.). Accordingly, those skilled in the art can adjust the shape and size of the first opening 206 so that it can be matched with the specific configuration of the longitudinal rib 117 to prevent the plunger rod 102 from rotating circumferentially.

As shown in FIG. 2, in an embodiment, the plunger rod 102 further includes a rod shoulder 118. The projection of the rod shoulder 118 along the axial direction of the plunger rod 102 is circular, and the projection roughly surrounds the projection of the longitudinal edge 117 . FIG. 5e shows a cross-sectional view of the plunger rod 102 when installed in the booster 200, which shows the rod shoulder 118. A part of the axial projection of the shoulder 118 is located outside of the axial projection of the first opening 206. When the plunger rod 102 slides in the first opening 206, this prevents the shoulder 118 from passing through the first opening 206.

As shown in Figures 1a and 1b, when assembling the syringe 10, the auxiliary dosing device 100 is inserted into the syringe 300 until the shoulder 118 is located inside the syringe, and then the mounting groove 203 of the booster 200 is engaged with the syringe 300 flange 302 to complete the assembly. It can be understood that after the assembly is completed, since the shoulder 118 located inside the barrel 300 cannot pass through the first opening 206 of the booster 200, the plunger rod 102 cannot be withdrawn from the barrel 300. The provision of the lever shoulder 118 can prevent the plunger rod 102 from being pulled to the proximal end excessively due to the operator's misoperation, and thus can prevent the plunger rod 102 from being separated from the syringe 300 due to the operator's misoperation.

6 and 7 respectively show schematic diagrams of a plunger rod 502 and a metering snap ring 504 according to another embodiment of the present application. Compared with the plunger rod 102 of FIG. 2 and the metering snap ring 104 of FIGS. 3a and 3b, similar structures in FIGS. 6 and 7 are denoted by similar reference numerals. For brevity, only the differences between the plunger rod 502 and the metering snap ring 504 and the plunger rod 102 and the metering snap ring 104 are described here.

As shown in FIG. 6, the positioning protrusion 515 has a width D1 in the axial direction, and its proximal end does not extend to the shoulder surface 514 but is away from the shoulder surface 514 by a distance D2.

As shown in Figure 7, the metering snap ring 504 further includes a displacement groove 529, which extends approximately along the circumferential direction of the metering snap ring 504 and has a width W1 in the axial direction. The end side and the boss surface 523 are spaced apart by W2 in the axial direction.

In an embodiment, D1 is approximately equal to or slightly smaller than W1, and D2 is approximately equal to or slightly larger than W2, so that when the boss surface 523 of the metering snap ring 504 abuts against the shoulder surface 514 of the plunger rod 502, it can pass The metering snap ring 504 is rotated so that the positioning protrusion 515 enters the displacement groove 529 and is finally displaced to the safety groove 525. At this time, as mentioned above, the boss surface 523 of the metering snap ring 504 no longer abuts the shoulder surface 514 of the plunger rod 502, and the metering snap ring 504 can move axially toward the proximal end relative to the plunger rod 502. The distance D is until the first end surface 521 of the metering snap ring 504 abuts the shoulder surface 514 of the plunger rod 502. It can be understood that the distance D is equal to the height H of the metering boss 122 in the axial direction (as shown in FIG. 4).

Fig. 8a, Fig. 8b and Fig. 8c respectively show the syringe 10 in different usage states. As shown in Fig. 8a, Fig. 8a shows the assembled syringe 10, and the barrel of the syringe 10 is filled with liquid, which may be a pre-filled liquid or a liquid drawn on the spot by an operator. In FIG. 8a, the positioning protrusion 115 of the plunger rod 102 is located in the positioning groove 124 of the metering snap ring 104, and the elastic pawl 116 of the plunger rod 102 abuts the shoulder 128 of the metering snap ring 104. When the plunger rod 102 is pushed axially relative to the syringe 300 to empty the syringe 300, the plunger rod 102 gradually moves to the distal end until the plunger 102 can no longer be pushed (that is, the metering snap ring 104 The second end surface 129 abuts the first piece 204 of the booster 200, and the boss surface 123 of the metering snap ring 104 abuts the shoulder surface 114 of the plunger rod 102), at this time the syringe 10 enters the state of FIG. 8b.

In FIG. 8b, the second end surface 129 of the metering snap ring 104 abuts the first piece 204 of the booster 200, and the boss surface 123 of the metering snap ring 104 abuts the shoulder surface 114 of the plunger rod 102. After the metering snap ring 104 is rotated so that the positioning protrusion 115 of the plunger rod 102 is located in the safety groove 125 of the metering snap ring 104, the plunger rod 102 can be pushed axially relative to the syringe 300 to perform the injection operation. At this time, the syringe 10 enters the state of FIG. 8c.

In FIG. 8c, the first end surface 121 of the metering snap ring 104 abuts the shoulder surface 114 of the plunger rod 102, and the second end surface 129 of the metering snap ring 104 still abuts the first piece 204 of the booster 200. It can be understood that, compared with FIG. 8b, the plunger rod 102 in FIG. 8c continues to advance relative to the barrel 300 by a distance D, which is equal to the axial height H of the metering boss 122 of the metering snap ring 104. Since the plunger rod 102 is accurately advanced by the distance D between FIG. 8b and FIG. 8c, the aforementioned injection operation can accurately inject a predetermined amount of liquid without the operator's visual observation and calibration.

Although the present invention has been described in detail with reference to certain preferred embodiments, there are various changes and modifications in the scope and mental memory of one or more independent aspects of the described invention.

10: Syringe 100: auxiliary dosing device 102: Plunger rod 104: Metering snap ring 110: Proximal 111: remote 112: Pushing part 113: Shoulder 114: Shoulder surface 115: positioning convex 116: elastic pawl 117: Longitudinal edge 118: shoulder/shoulder 119: Columnar convexity 121: first end face 122: metering boss 123: boss surface 124: positioning groove 125: safety groove 126: Anti-regressive cavity 127: Groove 128: Shoulder 129: second end face 200: booster 201: The main part 202: Wing 203: fixed groove/groove/installation groove 204: First piece 205: The second piece 206: The first opening 300: Syringe 301: Tube 302: Flange 400: Plunger 502: Plunger Rod 504: Metering snap ring 514: Shoulder Surface 515: positioning convex 523: boss surface 529: shift groove

Figures 1a and 1b respectively show an exploded view and an assembly view of a syringe 10 according to an embodiment of the present invention.

2a and 2b respectively show a front view and a cross-sectional view of the plunger rod 102 according to an embodiment of the present invention.

3a and 3b respectively show a perspective view and a longitudinal section view of a metering snap ring 104 according to an embodiment of the present invention.

Fig. 4 shows an assembled auxiliary dosing device 100 according to an embodiment of the present invention.

5a to 5c show a perspective view, a top view and a front view of the booster 200, respectively.

FIG. 5d shows a cross-sectional view of the plunger rod 102 and the booster 200 after the plunger rod 102 and the booster 200 are assembled.

Figure 5e shows a cross-sectional view of the plunger rod 102 together with the booster 200 after the plunger rod 102 and the booster 200 are assembled, wherein the rod shoulder 118 is further shown.

FIG. 6 shows a schematic diagram of a plunger rod 502 according to another embodiment of the present application.

FIG. 7 shows a schematic diagram of a metering snap ring 504 according to another embodiment of the present application.

Figures 8a to 8c show the syringe 10 in different states of use.

Before explaining any embodiments of the present invention in detail, it should be understood that the application of the present invention is not limited to the details of the configuration and the arrangement of components set forth in the following description or shown in the following drawings. The present invention can have other embodiments and can be practiced or implemented in various ways. Moreover, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered restrictive.

10: Syringe

100: auxiliary dosing device

102: Plunger rod

104: Metering snap ring

200: booster

203: fixed slot

300: Syringe

301: Tube

302: Flange

400: Plunger

Claims (18)

An auxiliary quantitative device for a syringe, characterized in that the auxiliary quantitative device comprises: A plunger rod having a proximal end and a distal end; and A dose snap ring sleeved on the outer circumference of the plunger rod and capable of moving axially along the plunger rod; The metering snap ring is configured to be able to rotate circumferentially from a first position to a second position relative to the plunger rod; Wherein when the metering snap ring rotates circumferentially from the first position to the second position, the plunger rod can move a distance in the direction of the distal end relative to the metering snap ring in the axial direction . The auxiliary quantitative device according to claim 1, wherein: The plunger rod includes a shoulder at the proximal end of the plunger rod, and the shoulder has a shoulder surface at the distal side of the shoulder; The metering snap ring includes a first end surface located on the proximal side of the dose snap ring and a metering boss protruding from the first end to the proximal side in the axial direction, the metering boss including a protrusion Table surface Wherein when the metering snap ring is in the first position, the shoulder surface abuts against the boss surface; and when the metering snap ring is in the second position, the shoulder surface abuts The first end surface. The auxiliary quantitative device according to claim 2, wherein The plunger rod further includes a positioning protrusion extending axially on the distal side of the shoulder; The dosage snap ring also includes: A positioning groove provided on the inner surface of the dose retaining ring, the positioning groove being configured to allow the positioning protrusion to slide therein; and A safety groove provided on the inner surface of the dose retaining ring, the safety groove being configured to allow the positioning protrusion to slide therein; Wherein when the metering snap ring is at the first position, the positioning protrusion is located in the positioning groove, and when the metering snap ring is at the second position, the positioning protrusion is located at the In the safety groove, and when the plunger rod rotates circumferentially from the first position to the second position, the positioning protrusion separates from the positioning groove and moves into the safety groove. The auxiliary quantitative device according to claim 3, wherein the shoulder portion and the positioning convex portion are substantially aligned in the axial direction of the plunger rod. The auxiliary dosing device according to claim 3, wherein the plunger rod includes a plurality of positioning protrusions arranged at intervals along the circumferential direction of the plunger rod, and a plurality of positioning projections are correspondingly provided on the dose snap ring Groove. The auxiliary dosing device according to claim 3, wherein the positioning protrusion is made of an elastic material, and when the dose snap ring is rotated relative to the plunger rod, the positioning protrusion can be elastically deformed to Break away from the positioning groove and move into the safety groove. The auxiliary quantitative device according to claim 3, wherein the metering snap ring further includes a displacement groove connecting the positioning groove and the safety groove, wherein the displacement groove is configured to When the metering snap ring is rotated relative to the plunger rod with the boss surface abutting the shoulder surface, the positioning protrusion can be moved from the positioning groove to the displacement groove along the displacement groove. Inside the safety groove. The auxiliary dosing device according to any one of claims 1 to 7, wherein the plunger rod further includes a device for restricting the axial sliding of the dose retaining ring to the distal end relative to the plunger rod The limiting member, and the inner surface of the dose retaining ring is provided with a positioning joint part which can be engaged with the limiting member. The auxiliary quantitative device according to claim 8, wherein the limiting member is an elastic pawl protruding outward from the outer peripheral surface of the plunger rod, and the positioning joint is provided on the dose card A shoulder at the distal end of the inner surface of the ring. The auxiliary dosing device according to claim 9, wherein the limiting element includes a plurality of elastic pawls, and when the distal end of the plunger rod is inserted into the dose retaining ring and relatively sliding along the axial direction, the The elastic pawl can be elastically compressed to pass through the proximal end of the dose retaining ring. A syringe, characterized in that the syringe comprises: A syringe A plunger slidably disposed in the syringe; and The auxiliary quantitative device according to any one of claims 1-10. The syringe according to claim 11, wherein the plunger rod further includes a cylindrical protrusion at the distal end of the plunger rod, and the plunger includes a central hole, wherein the cylindrical protrusion It can be inserted into the central hole, and the height of the cylindrical protrusion is greater than the height of the plunger of the syringe. The syringe according to claim 11, wherein the syringe further comprises: A booster for engaging a proximal flange of the needle barrel, the booster including a first piece, a second piece, and connecting the first piece and the second piece The first piece, the second piece, and the connecting wall define a fixing groove that can receive the proximal flange of the syringe, wherein the first piece defines a A first opening, the second sheet body defines a second opening, and the shape and size of the first opening are set to allow the plunger rod to slide axially in the first opening. The syringe according to claim 13, wherein the plunger rod includes a plurality of longitudinal ribs arranged radially, and viewed from the cross section of the plunger rod, the outermost side connecting the plurality of longitudinal ribs may be A polygon is formed, and the shape and size of the first opening correspond to the polygon, thereby preventing the plunger rod from rotating circumferentially relative to the booster. The syringe according to claim 14, wherein the plunger rod includes four longitudinal edges, viewed from the cross section of the plunger rod, the outermost side connecting the four longitudinal edges may form a square, wherein The first opening includes a substantially square portion corresponding to the square. The syringe according to claim 14 or claim 15, wherein the plunger rod further includes a shoulder between the distal end and the proximal end, and an axial direction of the plunger rod is at least A part of the projection is located outside the projection of the first opening, so that the shoulder cannot pass through the first opening. The syringe according to claim 16, wherein the projection of the shaft shoulder along the axial direction of the plunger rod is circular, and at least a part of the circular is located outside the projection of the first opening. The syringe according to claim 13, wherein the booster further includes a wing portion extending radially outward from the first sheet body or the second sheet body.

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