Medical syringe plunger and medical finger grip

Abstract

To provide a plunger and a finger grip which have both a dose accuracy function and a pull-out prevention function in a medical disposable syringe.SOLUTION: A plunger rod comprises: a first guide groove which can guide the axial movement of a projection which is provided toward the center of a hole in a finger grip upon the entering of the projection into the first guide groove; a second guide groove which is provided at a position rotated by a specific angle in a circumferential direction of the plunger rod relative to the first guide groove and can guide the axial movement; an axial movement restriction unit which is provided in the vicinity of an end of the first guide groove and can restrict the axial movement; and a projection movement unit which enables the projection to move from the first guide groove to the second guide groove.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a syringe plunger and a finger grip that constitute a medical syringe. [Background technology]

[0002] Generally, a medical syringe consists of a syringe barrel with an injection needle attached to its tip and a syringe plunger inserted through an opening at the other end to move a piston in the axial direction. The opening at the other end of the syringe barrel is provided with a flange protruding radially outward. Such syringes require a backstop function to prevent the plunger from unintentionally coming off the barrel after the plunger tip is inserted into the barrel. They also require a function to ensure that a fixed amount of medicinal liquid is discharged from the syringe tip during injection.

[0003] For example, Patent Document 1 proposes a syringe in which the plunger is shaped like a sawtooth blade with multiple recesses, and a complex mechanism is provided on finger wings attached to a flange to dispense a fixed amount of liquid. Patent Document 2 discloses a syringe with a complex structure in which the plunger is composed of two shaft members, and the contents are sprayed out in small amounts.

[0004] [Patent Document 1] US Patent Publication No. 2019111211A1 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-80189 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0005] Prefilled syringes, which are pre-filled with an accurate dosage, are used to simplify medication management, prevent infection, prevent errors during preparation, and ensure rapid administration. For example, even extremely small-volume syringes for ophthalmic use are required to have a dose accuracy (accuracy of filling, i.e., administration) function that allows the barrel to be accurately filled with the specified amount of oral solution with a simple operation. Furthermore, from the perspective of medical safety, such as preventing infection, a backstop function is also required to prevent the plunger from being pulled out of the syringe barrel, ensuring that a used syringe is not reused after injection.

[0006] Therefore, there is a need to provide a syringe with an extremely small capacity that is a disposable product intended for single use and that combines a dose accuracy function and a plunger pull-out prevention function without relying on a complex mechanism. [Means for solving the problem]

[0007] (1) The medical syringe plunger of the present invention comprises a plunger rod and a plunger head attached to the end thereof, and is intended to be inserted into a hole in a finger grip attached to the flange portion of a syringe barrel.

[0008] The plunger rod has a first guide groove and a second guide groove. The first guide groove is provided over a first predetermined length in the axial direction from the tip of the plunger rod, and a protrusion provided toward the center of the hole in the finger grip fits into the first guide groove to guide the axial movement of the plunger rod. The second guide groove is provided at a position rotated a predetermined angle circumferentially of the plunger rod relative to the first guide groove, and extends over a second predetermined length in the axial direction, and the protrusion fits into it to guide its axial movement.

[0009] With this configuration, the finger grip protrusion can move a first predetermined distance in the axial direction within the first guide groove from the tip of the plunger rod toward the distal end. By placing oral solution and a piston in the syringe barrel and pushing the piston with the tip of the plunger rod, and moving the finger grip protrusion the first predetermined distance in the axial direction within the first guide groove toward the distal end of the plunger rod, a predetermined amount of oral solution can be retained in the syringe barrel.

[0010] In one embodiment of the present invention, the third guide groove may be provided on an extension of the first guide groove, and the distance the plunger rod can be pushed in may be set to the first predetermined length plus the third predetermined length. In this case, too, the piston can be pushed in with the tip of the plunger rod to dispense a predetermined amount of oral solution into the syringe barrel.

[0011] The plunger rod can be rotated a predetermined angle in the circumferential direction to move the finger grip protrusion into the second guide groove, and the plunger rod can be further pushed in to move the protrusion by a second predetermined length, thereby administering the entire amount of oral liquid.

[0012] (2) In the present invention, in the medical syringe plunger of (1), a protrusion transition portion that allows the protrusion to transition from the first guide groove to the second guide groove can be provided between the first guide groove and the second guide groove.

[0013] In one embodiment of the present invention, a third guide groove is provided on an extension line of the first guide groove, extending from the terminal end of the first guide groove over a third predetermined length. The second guide groove has a starting end located closer to the distal end than the terminal end of the first guide groove and a terminal end located on the distal end side of the plunger rod. A partition wall having an upper cross section that is thinner than a lower cross section is formed between at least a portion of the side surface of the third guide groove and the side surface of the starting end portion of the second guide groove. Such a partition wall is provided as a protrusion transition portion.

[0014] Even if you try to push the plunger head in while the protrusion is in the third guide groove, once the protrusion reaches the end of the third guide groove, the plunger rod will not be able to move any further in the axial direction, and the oral liquid will not be ejected from the tip of the plunger barrel.

[0015] By turning the plunger head and rotating the plunger rod by a predetermined angle, the protrusion overcomes the partition and enters the second guide groove, allowing axial movement. By further pushing the plunger rod, the protrusion can be moved a second predetermined length, allowing the entire amount of oral liquid to be administered. Forming a partition wall with a width equal to or slightly larger than the thickness of the protrusion between at least a portion of the side surface of the third guide groove and the side surface of the starting end of the second guide groove allows the protrusion to overcome. Furthermore, the protrusion transition portion is a partition wall with an upper cross section that is thinner than the lower cross section, i.e., a partition wall with an acute cross section that tapers at the top, making it easier for the protrusion to overcome the partition wall.

[0016] (3) In the present invention, in the medical syringe plunger of (1) or (2), an axial movement limiting portion can be provided that allows the protrusion to move toward the plunger head up to the terminal end of the first guide groove, but limits axial movement on an extension of the first guide groove once the protrusion passes the terminal end. Also, the second guide groove can have a starting end located closer to the tip end of the plunger rod than the axial movement limiting portion, and a terminal end located closer to the end of the plunger rod.

[0017] In one embodiment of the present invention, the axial movement limiting portion is the start end of a third guide groove provided on an extension line of the first guide groove, which is also the end (upright wall surface) of the first guide groove, which has a wedge-shaped end near its end. After the protrusion of the finger grip passes the end of the first guide groove, the protrusion can only move axially in the third guide groove a short axial length of the third guide groove (a third predetermined length).

[0018] When the protrusion of the finger grip reaches the end of the third guide groove, a predetermined amount of oral liquid is held in the syringe barrel. The amount of oral liquid filled into the syringe is determined by the relationship between the inner diameter of the hollow body of the syringe barrel used in combination with it and the position of the tip of the fixed plunger rod when the protrusion reaches the end of the third guide groove. Therefore, by appropriately setting the first predetermined length to the end of the first guide groove and the third predetermined length to the end of the third guide groove depending on the syringe barrel to be used, the syringe barrel can be accurately filled with a predetermined amount of oral liquid by simply pushing the plunger rod into the syringe barrel.

[0019] The second guide groove has a starting end located closer to the distal end than the axial movement limiting portion (the terminal end of the first guide groove) and a terminal end located on the distal end side of the plunger rod. By appropriately setting the terminal position of the second guide groove, the entire amount of the oral solution in the syringe barrel can be reliably administered by simply pushing the plunger rod into the syringe barrel.

[0020] Furthermore, since the finger grip protrusion cannot move further toward the tip of the plunger rod than the axial movement limiting portion (the end of the first guide groove), the syringe plunger cannot be pulled out of the syringe barrel after the oral liquid has been administered.

[0021] (4) The medical syringe plunger according to the present invention comprises a plunger rod and a plunger head attached to its distal end, and is intended for use by being inserted into a hole in a finger grip attached to the flange of a syringe barrel. The plunger rod has a first guide groove extending from its distal end in the axial direction over a first predetermined length, into which a protrusion provided toward the center of the hole in the finger grip fits to guide its axial movement. The first guide groove is formed in a wedge shape from just before its terminal end to its end, with a slope from the bottom of the first guide groove toward the surface of the plunger rod, and the end is an upright wall. The portion of the first guide groove near its end is formed as a wedge-shaped portion with a wedge-shaped cross section.

[0022] When the medical syringe plunger configured in this way is inserted into the hole in the finger grip attached to the flange of the syringe barrel, the protrusion of the finger grip, with its tip pressed against the wedge-shaped slope, passes the end of the first guide groove, and the upright wall prevents the protrusion from moving axially in the opposite direction, thereby fixing the position of the tip of the plunger rod inside the syringe barrel.

[0023] In one embodiment of the present invention, a third guide groove is provided on an extension of the first guide groove, extending from the terminal end of the first guide groove for a third predetermined length. When the plunger rod is pushed in and the protrusion of the finger grip reaches the terminal end of the third guide groove, the plunger rod cannot be pushed any further. This allows a predetermined amount of oral solution to be held in the syringe barrel. Furthermore, the terminal end (upright wall surface) of the first guide groove prevents the protrusion of the finger grip from moving in the opposite direction, preventing the plunger rod from being pulled out of the hole in the finger grip.

[0024] (5) The medical finger grip according to the present invention is shaped to be attached so as to cover at least a portion of the flange of a syringe barrel. A hole for passing a plunger rod is formed in a flat plate portion for closing the opening of the flange, and the flat plate portion has a protrusion extending toward the center of the hole. This protrusion has a length that reaches a predetermined depth of a guide groove formed in the plunger rod, and is formed so that its tip bends when it goes over a structure formed in the guide groove, such as a wedge-shaped slope or a partition wall, and then returns to its original shape after going over it.

[0025] When a plunger rod is inserted into the hole of the medical finger grip configured in this way and used, the protrusion moves within the guide groove to guide the axial movement of the syringe plunger. If a wedge-shaped portion is provided in the guide groove, as the protrusion moves along the slope of the wedge-shaped portion from the bottom of the guide groove toward the surface of the plunger rod, its tip is pressed against the slope and bends, and after passing through the wedge-shaped portion, it returns to its original shape. If the end of the wedge-shaped portion is an upright wall surface, the protrusion prevents the plunger rod from moving in the reverse direction. If a first guide groove and a second guide groove are provided on the plunger rod and a partition is formed between them, the tip of the protrusion is pressed against the partition and bends, and after passing through the partition, it returns to its original shape. This allows the protrusion to move from the first guide groove to the second guide groove. [Effects of the Invention]

[0026] The medical syringe plunger and medical finger grip of the present invention can provide a disposable syringe intended for single use that can be filled with and administered with a predetermined amount of oral liquid without requiring a complex structure or complicated operation, and that can prevent the syringe plunger from being pulled out after use. [Brief explanation of the drawings]

[0027] [Figure 1]FIG. 1A is a perspective view showing an example of the configuration of a medical syringe in which a syringe plunger and a finger grip according to one embodiment of the present invention are assembled together with a syringe barrel, and FIG. 1B is a perspective view of the medical syringe shown in FIG. 1A, seen from a different angle, showing the attachment of the finger grip to the cutout portion and flange portion. [Figure 2] FIG. 2 is an axial cross-sectional view of the syringe barrel shown in FIG. 1. [Figure 3] 1A and 1B show the configuration of one embodiment of a finger grip according to one embodiment of the present invention, in which (A) is a perspective view, (B) is a top view, (C) is a side view seen from the direction indicated by the arrow S in (B), and (D) is a bottom view. [Figure 4] FIG. 1 is a side view showing the configuration of an embodiment of a syringe plunger according to an embodiment of the present invention. [Figure 5] 5A and 5B are cross-sectional views of the syringe plunger shown in FIG. 4, where (A) is an A-A' cross-sectional view seen from the tip of the syringe plunger, (B) is a B-B' cross-sectional view seen from the tip of the syringe plunger, and (C) is a C-C' cross-sectional view. [Figure 6] 5A is a perspective view showing the configuration of a part of the rod of the plunger shown in FIG. 4, and FIG. 5B is an enlarged view of part B surrounded by a dashed line in FIG. [Figure 7] 2 is a partially enlarged perspective view of the medical syringe shown in FIG. 1 for illustrating the configuration and operation of a syringe plunger according to one embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] The configuration of a medical syringe plunger and a medical finger grip according to one embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows an example of a configuration in which a syringe plunger and a finger grip according to one embodiment of the present invention are assembled together with a syringe barrel to form a medical syringe. This medical syringe is, for example, a very small-capacity syringe for ophthalmology, and is a disposable syringe intended for single use.

[0029] 1, the syringe 10 is an assembly of a syringe barrel 20, a finger grip 30, a syringe plunger 40, and a piston 50. An oral solution 60 is contained in the hollow body of the cylindrical syringe barrel 20, and the oral solution 60 is forced out of the tip of the syringe barrel 20 by pushing the piston 50 with the tip of the syringe plunger 40. As shown in FIG. 1, the syringe barrel 20 is a transparent cylindrical body molded from, for example, glass or polyolefin resin, so that the oral solution 60, the piston 50, and part of the syringe plunger 40 inside the hollow body can be seen.

[0030] 2 is an axial cross-sectional view showing one example of the configuration of syringe barrel 20. Syringe barrel 20 comprises a cylindrical body 21 for containing an internal liquid, an injection nozzle 22 formed at one end of body 21, and a flange 23 provided at the opening at the other end of body 21 and protruding radially outward. In addition to being fitted with an injection needle, injection nozzle 22 is also used for mixed injection into an intravenous drip or for mixing two drugs between syringes.

[0031] In a syringe with a very small capacity, the outer diameter of flange portion 23 is small, so a finger grip is attached to flange portion 23 to improve operability by, for example, medical personnel. 3A and 3B show the configuration of one embodiment of finger grip 30, with (A) being a perspective view, (B) being a top view, (C) being a side view as viewed from the direction indicated by arrow S in (B), and (D) being a bottom view. In FIG. 3, finger grip 30 comprises flat plate portion 31 for closing the opening of flange portion 23 of syringe barrel 20, and cover portion 32 for covering flange portion 23 except for a portion thereof, with cover portion 32 having notch 33 for attachment to flange portion 23. As shown in FIGS. 3A and 3C, finger grip 30 has a hollow structure with internal space 34 into which flange portion 23 of syringe barrel 20 and the body portion in the vicinity thereof are fitted, as shown in FIG. 1B.

[0032] As shown in Figures 3(B) and (D), the flat plate portion 31 is provided with a hole 35 for inserting a plunger rod, and this hole 35 is formed so that a tongue-like protrusion 36 that tapers toward the center extends from this hole 35. This protrusion 36 has a length that reaches a predetermined depth of a groove provided in the plunger rod, which will be described later. Therefore, as shown in Figures 3(B) and (D), the hole 35 has a shape that combines an arc portion with a radius corresponding to the outer diameter of the plunger rod and a portion where the protrusion 36 is formed.

[0033] FIG. 4 is a side view of a syringe plunger 40 according to one embodiment of the present invention, and FIG. 5(A) is an A-A' cross-sectional view of the syringe plunger 40 of FIG. 4, (B) is a B-B' cross-sectional view of the syringe plunger 40, and (C) is a C-C' cross-sectional view of the syringe plunger 40. In FIG. 4, the syringe plunger 40 comprises a round rod-shaped plunger rod 41 and a disk-shaped plunger head 42 provided at the end thereof. The plunger rod 41 is provided with a first guide groove 44 extending over a length L1 in the axial direction from the tip 43 of the plunger rod 41, and a second guide groove 45 having a length L2 at a position rotated approximately 60 degrees circumferentially of the plunger rod 41 relative to the first guide groove 44.

[0034] As shown in FIG. 5(A), the first guide groove 44 has a sector-shaped cross section at its center, and two first guide grooves 44 are provided at positions on opposite sides of the plunger rod 41 in the circumferential direction. As shown in FIGS. 4 and 6(A), the width of the first guide groove 44 is wider at the tip 43 of the plunger rod 41, allowing the protrusion 36 to easily enter the first guide groove 44 when the plunger rod 41 is inserted into the hole 35 of the finger grip 30 shown in FIG. 3. Over a predetermined length from the tip 43 toward the distal end, the arc-shaped portion having a radius corresponding to the outer diameter of the plunger rod 41 gradually shortens, thereby restricting the circumferential movement of the protrusion 36 and allowing the protrusion 36 to guide the axial and rotational movement of the plunger rod 41. The sector-shaped cross section of the first guide groove 44 is shaped to accommodate the protrusion 36 of the finger grip 30 shown in FIG. 3 and guide the axial movement of the plunger rod 41.

[0035] As shown in Figures 4, 5(C), and 6(A), a wedge-shaped portion 46 (a portion having a wedge-shaped cross section formed by sloping from the bottom 51 of the first guide groove 44 toward the plunger rod surface 52 as it moves toward the distal end of the plunger rod 41) is formed near the terminal end of the first guide groove 44. As such, the first guide groove 44 includes a portion deep enough for the protrusion 36 to move without deformation and the wedge-shaped portion 46 through which the protrusion 36 moves while deforming. The terminal end of the first guide groove 44 is an upright wall surface 46E of the wedge-shaped portion 46. In addition, a third guide groove 47 is provided on an extension line of the first guide groove 44, extending for a length L3 from the upright wall surface 46E of the wedge-shaped portion 46. The terminal end 47E of the third guide groove 47 also forms an upright wall surface.

[0036] The second guide groove 45 has a starting end 45B located distally of the upright wall surface 46E of the wedge-shaped portion 46 and a terminal end 45E located near the distal end. Thus, there is an overlapping portion along an axial length L4 (shown in FIG. 5C) from the starting end 45B of the second guide groove to the terminal end 47E of the third guide groove. A partition wall 53 having a narrower upper cross section than a lower cross section is formed across this overlapping portion between the side surface of the third guide groove 47 and the side surface of the second guide groove 45, as shown in FIGS. 5B and 6B. The side wall 45S of the second guide groove 45 closest to the partition wall 53 begins at a starting line 54 and extends toward the distal end of the plunger rod 41. The starting line 54 and the partition wall 53 are positioned as shown in FIG. 5B. The axial length L4 of the partition wall 53 is set to be approximately equal to or slightly greater than the thickness T1 of the protrusion 36 of the finger grip 30. Additionally, the axial length L3 of the third guide groove 47 is set to approximately twice the axial length L4 of the partition wall 53. The second guide groove 45 and the third guide groove 47 are located at positions rotated 60 degrees in the circumferential direction and are each formed as a groove with a sector-shaped cross section. The sector-shaped cross sections of the second guide groove 45 and the third guide groove 47 are suitable for receiving the protrusion 36 of the finger grip 30 shown in FIG. 3 and for guiding the axial movement of the plunger rod 41.

[0037] 5B and 5C, the tip of the partition wall 53, which has a cross section protruding at an acute angle from the center of the plunger rod 41, is set lower than the surface 52 of the plunger rod 41. The thickness of the protrusion 36 of the finger grip 30 in FIG. 3 is set to be approximately equal to or slightly smaller than the axial length L4 of the partition wall 53. Therefore, the protrusion 36 is configured to be able to move circumferentially while contacting the surface of the partition wall 53 and overcome the partition wall 53. As shown in FIG. 6B, the partition wall 53 is formed between the starting end 45B of the second guide groove 45 and the ending end 47E of the third guide groove 47, allowing the protrusion 36 to move from the third guide groove 47 to the second guide groove 45.

[0038] 1 , the finger grip 30 and syringe plunger 40 are assembled, and the syringe plunger 40 is pushed in so that when the protrusion 36 of the finger grip 30 reaches the terminal end 47E of the third guide groove, the amount of oral liquid 60 in the syringe barrel 20 will be a predetermined amount. The inner diameter of the syringe barrel 20, the length of the syringe barrel 20, the axial length of the piston 50, the length L5 from the tip of the syringe plunger 40 to the terminal end 47E, and the thickness T1 (thickness of the protrusion 36) of the flat plate portion 31 of the finger grip 30 are set so that when the protrusion 36 reaches the terminal end 45E of the second guide groove 45, the entire amount of oral liquid 60 in the syringe barrel 20 will be administered.

[0039] Next, the operation of the finger grip 30 and syringe plunger 40 configured as described above will be described. First, a syringe is prepared in which the oral solution 60 is filled in the syringe barrel 20. The syringe barrel 20 shown in FIG. 2 is placed upright with the flange portion 23 facing up, and a predetermined amount or a slightly larger amount of the oral solution 60 is poured into the opening. Next, the piston 50 is inserted into the syringe barrel 20 through the opening in the flange portion 23. As shown in FIG. 1(B), the finger grip 30 is attached to the flange portion 23 by pushing the flange portion 23 from the side, aligning the cutout portion 33 with the flange portion 23, so that the flange portion 23 is sandwiched between the flat portion 31 and the cover portion 32 of the finger grip 30. As a result, the opening of the flange portion 23 is covered by the flat portion 31 with the hole 35 formed therein.

[0040] The plunger rod 41 is inserted into the hole 35, tip 43 first, with the projection 36 aligned to fit into the first guide groove 44. In this way, the finger grip 30 is attached to the flange portion 23 of the syringe barrel 20, and the syringe plunger 40 is inserted into the hole 35, as shown in FIG.

[0041] By pressing plunger head 42, plunger rod 41 is fed through hole 35 toward the tip of syringe barrel 20 while its circumferential movement is restricted by first guide groove 44 and protrusion 36. As protrusion 36 moves along the slope of wedge-shaped portion 46 from bottom 51 of first guide groove 44 toward surface 52, the tip of protrusion 36 is pressed against the slope and bent. After passing upright wall surface 46E, which is the end of wedge-shaped portion 46, bent protrusion 36 returns to its original shape. When the tip of bent protrusion 36, which is in the rear position, is directly above upright wall surface 46E, the base of protrusion 36, i.e., flat portion 31 of finger grip 30, is ahead and therefore moves above third guide groove 47. The axial length L3 of the third guide groove 47 is set to be greater than the thickness T1 of the protrusion 36, for example, twice as long, so that when the protrusion 36 returns to its original shape, the preceding flat plate portion 31 is still within the range of the third guide groove 47. In this way, the flat plate portion 31 does not extend beyond the terminal end 47E of the third guide groove 47.

[0042] As the plunger rod 41 moves axially, excess oral solution 60 is expelled from the injection nozzle of the syringe barrel 20 and air is also expelled from the barrel until the protrusion 36 reaches the terminal end 47E of the third guide groove 47. When the protrusion 36 passes over the wedge-shaped portion 46 and enters the third guide groove 47 and reaches the terminal end (upright wall surface) 47E, the axial movement of the plunger rod 41 stops, and a predetermined amount of oral solution 60 is retained within the syringe barrel 20. Note that when the protrusion 36 is within the third guide groove 47, the upright wall surface 46E and the terminal end (upright wall surface) 47E restrict the axial movement of the protrusion 36 of the plunger rod 41. Therefore, the plunger rod 41 cannot be pulled out or further pushed in. Through the above procedure, a syringe with dose accuracy (accuracy of filling and administration) is provided, in which a predetermined amount of oral solution 60 is filled in the syringe barrel 20. Furthermore, during the operation of pushing plunger rod 41 into syringe barrel 20, a "click" is heard when protrusion 36 passes upright wall surface 46E, which is the end of wedge-shaped portion 46. This allows medical personnel to know that the quantitative dispensing operation (stroke) is complete not only visually but also by sound and the feel of the touch.

[0043] Next, the injection procedure will be described. In FIG. 7, when the plunger head 42 is rotated approximately 60 degrees clockwise, the protrusion 36 overcomes the partition wall 53 and enters the second guide groove 45. Then, by pressing the plunger head 42, the oral solution 60 is expelled from the injection nozzle portion 22 of the syringe barrel 20. When the protrusion 36 reaches the end 45E, the entire predetermined amount of oral solution 60 is administered. Even if an attempt is made to withdraw the plunger rod 41 after this injection operation, the protrusion 36 stops at the beginning 45B of the second guide groove 45 and cannot be withdrawn any further. Furthermore, even if the plunger head 42 is rotated approximately 60 degrees counterclockwise to return the protrusion 36 to the third guide groove 47, the protrusion 36 cannot overcome the upright wall surface 46E toward the distal end, preventing the protrusion 36 from moving further, thereby preventing the plunger rod 41 from being withdrawn.

[0044] According to the embodiment described above, a syringe plunger and a finger grip that combine both a dose accuracy function and a pull-out prevention function in a disposable medical syringe can be provided. Furthermore, the syringe plunger and the finger grip according to this embodiment are suitable for a pre-filled syringe that is assembled by filling a syringe barrel with a medicinal solution in advance. [Explanation of symbols]

[0045] 10 syringes 20 syringe barrels 21 Torso 22 Injection nozzle 23 Flange 30 Finger Grip 31 Flat plate part 32 Cover part 33 Cutout 34 Interior Space 35 holes 36 Protrusion 40 Syringe Plunger 41 Plunger rod 42 Plunger head 43 Tip 44 First guide groove 45 Second guide groove 45B Starting end 45E termination 45S side wall 46 Cuneiform part 46E Upright wall 47 Third guide groove 47E Termination 51 bottom 52 Surface 53 Bulkhead 54 Starting Line 50 pistons 60 Oral liquid

Claims

1. A medical syringe plunger includes a plunger rod and a plunger head attached to the end thereof, and is inserted into a hole in a finger grip attached to a flange of a syringe barrel, The plunger rod is a first guide groove extending from the tip of the finger grip in the axial direction over a first predetermined length, the first guide groove receiving a protrusion extending toward the center of the hole in the finger grip to guide the axial movement of the finger grip; a second guide groove provided over a second predetermined length in the axial direction at a position rotated a predetermined angle circumferentially of the plunger rod relative to the first guide groove, the second guide groove being adapted for receiving the protrusion to guide its axial movement.

2. 2. The medical syringe plunger according to claim 1, wherein a protrusion transition portion is provided between the first guide groove and the second guide groove, which allows the protrusion to transition from the first guide groove to the second guide groove.

3. the projection can move toward the plunger head up to the end of the first guide groove, and an axial movement limiting portion is provided that limits the axial movement on an extension line of the first guide groove when the projection passes beyond the end, 3. The medical syringe plunger according to claim 1, wherein the second guide groove has a starting end located at a position not closer to the tip side than the axial movement limiting portion and a terminal end located at the distal end side.

4. A medical syringe plunger includes a plunger rod and a plunger head attached to the end thereof, and is inserted into a hole in a finger grip attached to a flange of a syringe barrel, The plunger rod is a first guide groove extending from the tip of the finger grip in the axial direction over a first predetermined length, into which a protrusion extending toward the center of the hole of the finger grip is inserted to guide the movement of the finger grip in the axial direction; A medical syringe plunger characterized in that the first guide groove is formed in a wedge shape having a slope from the bottom of the first guide groove toward the surface of the plunger rod from just before its end to its end, and the end is an upright wall surface.

5. A medical finger grip having a shape adapted to be attached so as to cover at least a portion of a flange portion of a syringe barrel, a flat plate portion for closing the opening of the flange portion is provided with a hole for passing a plunger rod therethrough, and the flat plate portion has a protrusion extending toward the center of the hole; A medical finger grip characterized in that the protrusion has a length that reaches a predetermined depth of the guide groove provided in the plunger rod, and is formed so that at least the tip bends when climbing over a structure and returns to its original shape after climbing over it.

Images