Paste injector

Abstract

To provide a paste injector which allows a user to grasp a residual amount of a paste in a paste storage chamber from appearance, by a simple structure.SOLUTION: A paste injector 1 comprises a syringe 3 and a plunger 5. The syringe 3 extends in a longer direction and has: a paste storage chamber 49 which extends in a longer direction X in an interior part of the syringe and in which a paste is filled. The syringe has a discharge hole 51 and a filling hole 53. The plunger 5 comprises a pressing part 67, and a rod-shaped part 69 which is inserted into the paste storage chamber 49 and erected from the pressing part 67. The rod-shaped part 69 has multiple reinforcement ribs 78A to 78E which reinforce the rod-shaped part 69 at prescribed intervals along the longer direction X. The reinforcement ribs 78B to 78E are formed at positions where they overlap with the filling hole 53 when a residual amount of the paste in the paste storage chamber 49 becomes a predetermined regulated amount.SELECTED DRAWING: Figure 30

Description

[Technical field]

[0001] The present invention relates to a paste injector. [Background technology]

[0002] A paste injector for discharging a paste-like dental material to a desired position is known. The paste injector includes a syringe that extends in the longitudinal direction and has a paste storage chamber filled with paste, and a plunger that is inserted into the syringe and can move in the longitudinal direction. For example, Patent Document 1 discloses a paste injector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2018 / 057503 Summary of the Invention [Problem to be solved by the invention]

[0004] However, a paste injector has a problem in that it is difficult to know the remaining amount of paste in the paste storage chamber from the outside due to the material of the syringe, the label attached to the syringe, etc. In particular, when a paste injector is shipped and used with the paste storage chamber filled with a plurality of doses of paste in advance, there is a need for the user to know the remaining amount of paste before use.

[0005] An object of the present invention is to provide a paste injector which has a simple structure and allows the amount of paste remaining in a paste storage chamber to be known from the outside. [Means for solving the problem]

[0006] The paste injector of the present invention includes a syringe extending in a longitudinal direction, having a paste storage chamber extending along the longitudinal direction and filled with paste, with one end formed with a discharge port opening one end of the paste storage chamber and the other end formed with a filling port opening the other end of the paste storage chamber, and a plunger having a pressing part pressed by a user's finger and a rod-shaped part rising from the pressing part and inserted into the paste storage chamber, the plunger being inserted into the paste storage chamber from the filling port and moving along the longitudinal direction to push out the paste from the discharge port. The rod-shaped part is provided with a plurality of reinforcing ribs at predetermined intervals along the longitudinal direction to reinforce the rod-shaped part, and at least a portion of the reinforcing ribs are formed in a position that overlaps with the filling port when the remaining amount of the paste in the paste storage chamber reaches a predetermined amount. Effect of the Invention

[0007] In this way, the paste injector of the present invention has a simple structure and makes it possible to know the remaining amount of paste in the paste storage chamber from the outside. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a front view of the paste injector of the present embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the paste injector. [Diagram 3] 1 is a cross-sectional view of a static mixer fixed to the tip of a syringe, cut widthwise at a position passing through a central axis extending in the longitudinal direction. [Figure 4A] FIG. [Figure 4B] FIG. [Figure 4C] FIG. [Figure 4D] FIG. [Diagram 5] 4D is a cross-sectional view taken along line VV shown in FIG. 4C. [Figure 6] 4B is an end view taken along line VI-VI shown in FIG. 4A. [Figure 7] FIG. 2 is a perspective view of the tip of the syringe. [Figure 8] 8 is a cross-sectional view of a main portion taken along line VIII-VIII in FIG. 4C. [Figure 9A] FIG. [Figure 9B] FIG. [Figure 9C] FIG. [Figure 9D] FIG. [Figure 10] FIG. 9A is a cross-sectional view taken along line XX. [Figure 11A] FIG. [Figure 11B] FIG. [Figure 12] 1 is a cross-sectional view of an elastic holder with an O-ring attached to an annular groove, cut in a width direction perpendicular to the longitudinal direction at a neck portion. FIG. [Figure 13] This is a cross-sectional view (schematic diagram) of an elastomer holder with an O-ring attached to the annular groove when inserted into a paste storage chamber of a syringe, cut in the width direction perpendicular to the longitudinal direction at the neck portion, and a cross-sectional view (schematic diagram) as viewed from the front and side. [Figure 14A] FIG. 2 is a perspective view of a mixing tip body. [Figure 14B] FIG. 2 is a bottom view of the mixing tip body. [Figure 15] 14C is a cross-sectional view taken along line XV-XV shown in FIG. 14B. [Figure 16A] FIG. 2 is a perspective view of a mixer housing. [Figure 16B] FIG. 2 is a bottom view of the mixer housing. [Figure 17] 17 is a cross-sectional view taken along line XVII-XVII shown in FIG. 16B. [Figure 18A] FIG. 2 is a front view of the mixer exterior body. [Figure 18B] FIG. 2 is a side view of the mixer exterior body. [Figure 18C]FIG. 2 is a plan view of the mixer exterior body. [Figure 18D] FIG. 2 is a bottom view of the mixer exterior body. [Figure 19] 19 is a cross-sectional view taken along line XIX-XIX shown in FIG. 18C. [Figure 20] 18D is a cross-sectional view taken along the line XX-XX shown in FIG. 18C. [Figure 21] 18B is a cross-sectional view taken along line XXI-XXI shown in FIG. 18A. [Figure 22A] FIG. 4 is a perspective view of the cap inner member. [Figure 22B] FIG. 4 is a bottom view of the cap inner member. [Diagram 23] 23 is a cross-sectional view taken along line XXIII-XXIII shown in FIG. 22B. [Figure 24A] FIG. [Figure 24B] FIG. [Figure 24C] FIG. [Figure 24D] FIG. [Diagram 25] 24D is a cross-sectional view taken along line XXV-XXV of FIG. 24C. [Figure 26] 26 is a cross-sectional view taken along the line XXVI-XXVI shown in FIG. 24C. [Figure 27] 24B is a cross-sectional view taken along line XXVII-XXVII shown in FIG. 24A. [Figure 28] FIG. 13 is a diagram showing a state prior to the static mixer being placed over and fixed onto the syringe. [Figure 29] FIG. 13 is a bottom view of the static mixer after only the mixer housing has rotated. [Diagram 30] FIG. 2 is a cross-sectional view of the paste injector cut widthwise at a position passing through a central axis extending in the longitudinal direction, showing that the remaining amount of paste is about 75%. [Diagram 31] FIG. 2 is a cross-sectional view of the paste injector cut widthwise at a position passing through a central axis extending in the longitudinal direction, showing that the remaining amount of paste is about 50%. [Diagram 32]FIG. 2 is a cross-sectional view of the paste injector cut widthwise at a position passing through a central axis extending in the longitudinal direction, showing that the remaining amount of paste is about 25%. [Diagram 33] 1 is a cross-sectional view of the paste injector cut widthwise at a position passing through a central axis extending in the longitudinal direction, showing that the remaining amount of paste is a predetermined amount for one use. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a paste injector of the present invention will be described with reference to the drawings.

[0010] <Overall composition> Fig. 1 is a front view of paste injector 1, and Fig. 2 is an exploded perspective view of paste injector 1. In this embodiment, as shown in Fig. 2, a longitudinal direction (X), a width direction (Y), and a thickness direction (Z) are defined for paste injector 1.

[0011] As shown in FIG. 1, the paste injector 1 includes a syringe 3, a plunger 5, a static mixer 7, and a guide tip 9. The paste injector 1 pushes out two types of pastes individually filled in the syringe 3 with the plunger 5, mixes them just before use with the static mixer 7 to prepare a dental material, and injects them into a desired location (such as an affected area or a dental cap) through the guide tip 9. The guide tip 9 is a nozzle member that is attached to the static mixer 7 in a fixed fit state as necessary. The paste injector 1 can be used even if the guide tip 9 is not attached to the static mixer 7.

[0012] When the paste injector 1 is stored or transported, a cap 11 shown in FIG. 2 is fixed to the tip of the syringe 3 (one end 41A of the syringe body 41 described later) instead of the static mixer 7. In this specification, the static mixer 7 and the cap 11 detachably attached to the tip of the syringe 3 (one end 41A of the syringe body 41) are collectively referred to as an attachment member M. The syringe 3, plunger 5, and attachment member M (static mixer 7 or cap 11) extend in the longitudinal direction X shown in FIG. 2 and are assembled in a state where the central axis CA passing through the center of each member is aligned.

[0013] The syringe 3 is filled with paste in advance and distributed with the plunger 5 inserted therein. The plunger 5 is composed of a plunger body 13, an elastic body holder 15 loosely engaged with the tip of the plunger body 13, and an annular O-ring (elastic body) 17 attached to the elastic body holder 15. Here, "loosely engaged" means that the elastic body holder 15 is engaged with the plunger body 13 by an engagement force that causes the elastic body holder 15 to come off from the plunger body 13 due to the frictional force between the syringe 3 and the O-ring 17. The elastic body holder 15 and the O-ring 17 form the tip of the plunger 5. It is needless to say that the plunger 5 may be an integrated one that is not separated into the plunger body 13 and the elastic body holder 15. In this case, the annular O-ring 17 may be directly attached to the tip of the plunger 5.

[0014] The static mixer 7 is composed of a mixing tip main body 19, a mixer housing 21, and a mixer exterior body 23. In this embodiment, the static mixer 7 is disposable.

[0015] The cap 11 is composed of a cap inner member 25 and a cap exterior body 27.

[0016] [Paste flow path] FIG. 3 is a cross-sectional view of the static mixer 7 fixed to the tip of the syringe 3, taken in the width direction Y at a position passing through a central axis CA extending in the longitudinal direction X.

[0017] In the static mixer 7, a paste flow path is formed by the mixing tip body 19 and the mixer housing 21. The paste flow path is composed of a paste passage 29, a paste passage 29', an intermediate passage 31, and a mixing passage 33. The paste passages 29, 29' are arranged circumferentially about the central axis CA, are arranged symmetrically along the width direction Y, and each extends in the longitudinal direction X. The mixing passage 33 is located downstream of the paste passages 29, 29' in the paste flow direction, and extends about the central axis CA extending in the longitudinal direction X. The intermediate passage 31 is a passage that connects the paste passages 29, 29' and the mixing passage 33.

[0018] The paste passage 29 is a passage through which the paste discharged from the paste storage chamber 49 of the syringe 3 flows. The paste passage 29 has an inflow hole 29A through which the paste flows in and an outflow hole 29B through which the paste flows out, and is formed in the mixing tip body 19. Here, the opening area of ​​the inflow hole 29A is larger than the opening area of ​​the outflow hole 29B. Furthermore, the opening center point of the outflow hole 29B is set at a position closer to the central axis CA than the opening center point of the inflow hole 29A.

[0019] The inner peripheral surface of the paste passage 29 has a distal surface 29C away from the central axis CA and a proximal surface 29D close to the central axis CA when viewed in a cross section perpendicular to the thickness direction Z. A tapered portion is formed on the distal surface 29C in a region from the inlet 29A to a midpoint of the paste passage 29. That is, the distal surface 29C is formed in a tapered shape in a portion from the inlet 29A to a midpoint of the paste passage 29, gradually approaching the central axis CA as it approaches the outlet 29B. As shown in FIG. 15 described later, the angle of the tapered portion, that is, the angle θ formed by the distal surface 29C and a straight line C1 passing through the center point of the inlet 29A and extending in the longitudinal direction X, is set to 45° here. The region of the distal surface 29C from the tapered portion to the outlet 29B extends parallel to the central axis CA and is along the central axis CA.

[0020] The proximal surface 29D extends parallel to the central axis CA from the inlet hole 29A to the outlet hole 29B and is aligned with the central axis CA. In other words, the area of ​​a cross section of the paste passage 29 perpendicular to the central axis CA (longitudinal direction X) gradually decreases at a constant rate from the inlet hole 29A to a midpoint of the paste passage 29, but becomes the same size as the opening area of ​​the outlet hole 29B from the midpoint of the paste passage 29 to the outlet hole 29B.

[0021] In this way, since the tapered portion of the distal surface 29C is formed in the region from the inlet hole 29A to a midpoint in the paste passage 29, the paste injector 1 can suppress the formation of air bubble accumulation in the paste passage 29, while reducing the amount of paste flowing into the paste passage 29 and reducing the amount of paste remaining in the paste passage 29 compared to when the distal surface 29C is formed in a tapered shape approaching the central axis CA from the inlet hole 29A to the outlet hole 29B.

[0022] The paste passage 29' is a passage through which the paste discharged from the paste storage chamber 49' of the syringe 3 flows. Since the paste passage 29' has a similar configuration to the paste passage 29, the reference numerals of the respective parts of the paste passage 29 are followed by "", and the description thereof will be omitted.

[0023] The paste passage 29 and the paste passage 29' are formed to have the same size and are symmetrical in the width direction Y with respect to the central axis CA. That is, the inlet hole 29A and the inlet hole 29A' are set to have the same opening area, and the outlet hole 29B and the outlet hole 29B' are set to have the same opening area. In addition, the distance from the central axis CA to the center of the inlet hole 29A when viewed along the central axis CA is the same as the distance from the central axis CA to the inlet hole 29A'. In addition, the distance from the central axis CA to the center of the outlet hole 29B when viewed along the central axis CA is the same as the distance from the central axis CA to the outlet hole 29B'. In addition, the inclination angle of the tapered portion of the distal surface 29C is the same as the inclination angle of the tapered portion of the distal surface 29C'.

[0024] The intermediate passage 31 is a passage that guides the paste flowing out from the outflow holes 29B, 29B' to the joining position JP. In this embodiment, a backflow prevention wall 35 is provided between the outflow holes 29B and 29B'. The backflow prevention wall 35 divides the intermediate passage 31 into the outflow hole 29B side and the outflow hole 29B' side, and prevents the paste from one outflow hole 29B (29B') from flowing into the other outflow hole 29B' (29B). Here, the backflow prevention wall 35 stands up from the end face of the mixing tip main body 19 where the outflow holes 29B, 29B' are formed, and extends to the joining position JP along the central axis CA. The backflow prevention wall 35 has curved surfaces 35A, 35A' formed at the base portion to direct the paste to the joining position JP.

[0025] The mixing passage 33 is a passage through which the pastes that join at the joining position JP pass while being mixed, and extends about a central axis CA that extends in the longitudinal direction X. The mixing passage 33 is composed of an element housing portion 37 that extends cylindrically in the mixer housing 21, and an element group 39 that extends from the end of the backflow prevention wall 35 and is inserted into the element housing portion 37.

[0026] [Fixing mounting parts] The static mixer 7 or the cap 11, which is the mounting member M, is detachably mounted to the tip end (one end 41A of the syringe body 41) of the syringe 3. The fixing structure will be described below.

[0027] Here, the mounting member M is composed of an inner member IM and an exterior body OM. When the mounting member M is a static mixer 7, the mixing tip main body 19 and the mixer housing 21 form the inner member IM, and the mixer exterior body 23 forms the exterior body OM. When the mounting member M is a cap 11, the cap inner member 25 forms the inner member IM, and the cap exterior body 27 forms the exterior body OM.

[0028] In the static mixer 7, the mixing tip main body 19 and the mixer housing 21 (inner member IM) are disposed inside the mixer exterior body 23 (exterior body OM). The mixing tip main body 19 and the mixer housing 21 are configured to be rotatable around the central axis CA within a predetermined angle range relative to the mixer exterior body 23. Similarly, in the cap 11, the cap inner member 25 (inner member IM) is disposed inside the cap exterior body 27 (exterior body OM). The cap inner member 25 is configured to be rotatable around the central axis CA within a predetermined angle range relative to the cap exterior body 27.

[0029] Then, when the tip portion of the syringe 3 (one end portion 41A of the syringe body 41) is inserted into the exterior body OM via the inner member IM along the central axis CA, the inner member IM becomes unable to rotate relative to the syringe 3, but the exterior body OM is rotatable relative to the syringe 3. When the exterior body OM rotates around the central axis CA in this state, only the exterior body OM rotates relative to the syringe 3, and the mounting member M is fixed to the tip portion of the syringe 3 (one end portion 41A of the syringe body 41) via the engagement structure.

[0030] The engagement structure has three or more pairs (three pairs in this embodiment) of engagement pairs each consisting of an engagement portion 45 formed on the syringe 3 and an engaged portion 107 formed on the mixer exterior body 23 which is the exterior body OM, or an engagement portion 45 formed on the syringe 3 and an engaged portion 129 formed on the cap exterior body 27 which is the exterior body OM. The detailed configurations of the engagement portion 45, the engaged portion 107, and the engaged portion 129 will be described later.

[0031] <Details of each component> [Syringe] Fig. 4A is a front view of syringe 3, Fig. 4B is a side view, Fig. 4C is a plan view, and Fig. 4D is a bottom view. In addition, Fig. 5 is a cross-sectional view taken along line VV in Fig. 4C, Fig. 6 is an end view taken along line VI-VI in Fig. 4A, Fig. 7 is a perspective view of the tip of the syringe, and Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 4C.

[0032] The syringe 3 is a cylindrical body extending in the longitudinal direction X, and includes a syringe body 41, two protrusions 43, 43', an engagement portion 45, and a finger hook portion 47.

[0033] The syringe body 41 has a plurality of (two in this example) paste storage chambers 49 and a paste storage chamber 49' formed therein, which are filled with paste. The two paste storage chambers 49, 49' are lined up along the width direction Y inside the syringe body 41 and formed to have the same shape. One end 41A of the syringe body 41 has a circular wall portion 41a that has a circular shape when cut in the width direction Y perpendicular to the longitudinal direction X, and the other end 41B has a finger hook portion 47 formed thereon.

[0034] The two protrusions 43, 43' are cylindrical parts that protrude in the longitudinal direction X from an end face of one end 41A (circular wall part 41a) of the syringe body 41 and have respective tips that become discharge outlets 51, 51'. The inner periphery of the protrusion 43 constitutes a part of the paste storage chamber 49, and the inner periphery of the protrusion 43' constitutes a part of the paste storage chamber 49'. The two protrusions 43, 43' are connected via an upright wall 41c that stands up from the circular wall part 41a, and the inclination is regulated.

[0035] As shown in Figures 7 and 8, a recess 41b is formed on the surface (end face of one end 41A) of the circular wall portion 41a. The recess 41b is formed between the peripheral edge of the circular wall portion 41a and the protruding portions 43, 43', and is appropriately stepped. The formation of the recess 41b on the surface of the circular wall portion 41a prevents the occurrence of sink marks when the syringe 3 is molded from resin. Furthermore, preventing the occurrence of sink marks can suppress the inclination of the protruding portions 43, 43'.

[0036] The engaging portion 45 constitutes an engaging structure for fixing the mounting member M to the tip portion (one end portion 41A of the syringe body 41) of the syringe 3, and is a portion that engages with the engaged portions (engaged portions 107 and 129) of the mounting member M (the static mixer 7 and the cap 11). The engaging portion 45 is composed of three protruding pieces 45A, 45B, and 45C formed on the outer circumferential surface of the circular wall portion 41a of the syringe body 41, as shown in FIG. 4C.

[0037] The protrusions 45A, 45B, and 45C are aligned in the rotation direction of the exterior body OM, and are asymmetrical about the central axis CA, which is the center of rotation of the exterior body OM, when viewed along the central axis CA. Note that "point symmetry" generally means that a figure overlaps with the original figure when rotated 180° about the symmetrical point, but "asymmetrical" here means that the protrusions 45A, 45B, and 45C do not overlap with each other when the syringe 3 rotates about the central axis CA, except when rotated 360°.

[0038] The protrusions 45A, 45B, and 45C are arranged at unequal intervals along the rotational direction of the exterior body OM. Here, the distance in the rotational direction from protrusion 45A to protrusion 45B is the same as the distance in the rotational direction from protrusion 45A to protrusion 45C. On the other hand, the distance in the rotational direction from protrusion 45B to protrusion 45C is shorter than the distance from protrusion 45A to protrusion 45B and the distance from protrusion 45A to protrusion 45C.

[0039] Furthermore, the protrusions 45A, 45B, and 45C have different shapes when viewed along the central axis CA. That is, the length of the protrusion 45A in the rotational direction is longer than the lengths of the protrusions 45B and 45C in the rotational direction. On the other hand, the lengths of the protrusions 45B and 45C in the rotational direction are the same, but the directions in which they protrude from the outer circumferential surface of the circular wall portion 41a are different.

[0040] The protrusion 45B and the protrusion 45C are shaped symmetrically with respect to a symmetry axis AS that passes through the central axis CA and the circumferential center position of the protrusion 45A.

[0041] Finger hook 47 is a flange-shaped portion extending in width direction Y and thickness direction Z from the outer peripheral surface of the other end 41B of syringe body 41. Finger hook 47 has a substantially hexagonal outer peripheral shape as shown in Figs. 4C and 4D. Finger hook 47 may be textured on at least surface 47a on one end 41A side. By textured surface 47a, it is possible to prevent fingers from slipping during use and to make gate marks less noticeable, thereby improving the quality of the appearance.

[0042] As shown in FIG. 6, the outer circumferential surface of the syringe body 41 has a pair of widthwise outer circumferential surfaces 57, 57', a pair of thicknesswise outer circumferential surfaces 59, 59', and four connecting outer circumferential surfaces 61.

[0043] The pair of widthwise outer peripheral surfaces 57, 57' are surfaces of the outer peripheral surface of the syringe body 41 that are located on opposite sides along the thickness direction Z. The widthwise outer peripheral surfaces 57, 57' each have a flat portion 57A that is flat along the longitudinal direction X and the width direction Y. In addition, the widthwise outer peripheral surfaces 57, 57' each have a groove-shaped recessed portion 57B that extends in the longitudinal direction X and is recessed further than the flat portion 57A. The recessed portion 57B is located between two paste storage chambers 49, 49' formed inside the syringe body 41, and the flat portion 57A is divided into two by the recessed portion 57B along the width direction Y. In addition, the recessed portion 57B has a wedge-shaped cross section in which the length in the width direction Y gradually narrows as it becomes deeper.

[0044] The pair of thickness direction outer peripheral surfaces 59, 59' are surfaces of the outer peripheral surface of the syringe body 41 that are located opposite each other along the width direction Y. The thickness direction outer peripheral surfaces 59, 59' are curved outward in the width direction Y with a predetermined radius of curvature, which is set to a curved surface of R5 in this example.

[0045] The connecting outer peripheral surface 61 is a surface set between the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, between the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59, between the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59', and between the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59', among the outer peripheral surfaces of the syringe body 41. The connecting outer peripheral surface 61 is curved with a predetermined curvature radius (for example, curvature radius R1 to R5, R2.5 in this embodiment), and smoothly connects the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59', and the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59', respectively. The connecting outer peripheral surface 61 and the pair of thickness direction outer peripheral surfaces 59, 59' are formed by combining multiple curved surfaces set to different curvature radii. The connecting outer circumferential surface 61 and the pair of thickness direction outer circumferential surfaces 59, 59' may be formed by curved surfaces set to the same radius of curvature.

[0046] The paste storage chamber 49 has a discharge port 51 at one end 49A (projection 43) that opens one end of the paste storage chamber 49 and discharges the paste pushed out by the plunger 5, and a filling port 53 at the other end 49B that opens the other end of the paste storage chamber 49. The paste storage chamber 49 has a tapered shape at one end 49A into which the tip end (top 83 of the elastic holder 15) of the plunger 5 inserted into the paste storage chamber 49 fits. In addition, a stopper protrusion 55 is provided on the inner peripheral surface of the other end 49B to prevent the plunger 5 inserted into the paste storage chamber 49 from falling out. Since the paste storage chamber 49' has the same configuration as the paste storage chamber 49, the same reference numerals as those of the paste storage chamber 49 are used and the description will be omitted.

[0047] As shown in Fig. 6, the cross-sectional shape of the paste storage chamber 49 cut in a direction perpendicular to the longitudinal direction X is an ellipse shape in which the long axis direction LA is along the thickness direction Z and the short axis direction SA is along the width direction Y. The term "ellipse shape" is a concept including not only an ellipse defined by geometry, but also shapes that are similar to an ellipse, such as an oval (a shape formed by connecting two semicircles with two straight lines), an elliptical arch shape (a shape formed by cutting out a part of an ellipse along a straight line), a flattened ellipse (a shape formed by crushing an ellipse in the long axis or short axis direction), and an oval shape. In this embodiment, the inner peripheral surface of the paste storage chamber 49 is composed of a pair of inner flat surface portions 63, 63' that are flat along the longitudinal direction X and the thickness direction Z, and a pair of inner curved surface portions 65, 65' that are curved at a predetermined curvature.

[0048] The pair of inner flat surface portions 63, 63' face each other in the width direction Y, sandwiching the internal space of the paste storage chamber 49 therebetween. The pair of inner curved surface portions 65, 65' face each other in the thickness direction Z, sandwiching the internal space of the paste storage chamber 49 therebetween, and smoothly connect the pair of inner flat surface portions 63, 63'. As a result, in this embodiment, the cross-sectional shape of the inner circumferential surface of the paste storage chamber 49 presents a flattened ellipse.

[0049] In this embodiment, the length dimension T1 in the long axis direction LA of the elliptical shape of the inner peripheral surface of the paste storage chamber 49 is preferably within a range of 1.1 to 2.0, where the length dimension W1 in the short axis direction SA is 1. In this embodiment, the length dimension T1 in the long axis direction LA is set to 1.3, where the length dimension W1 in the short axis direction SA is 1. Specifically, the length dimension T1 in the long axis direction LA is preferably 5 mm to 20 mm, and the length dimension W1 in the short axis direction SA is preferably 4.5 mm to 10 mm.

[0050] [Plunger body] Fig. 9A is a front view of the plunger body 13, Fig. 9B is a side view, Fig. 9C is a plan view, and Fig. 9D is a bottom view. Also, Fig. 10 is a cross-sectional view taken along line XX shown in Fig. 9A.

[0051] The plunger body 13 includes a pressing portion 67 and two rod-shaped portions 69 and 69'.

[0052] The pressing portion 67 is a portion that is pressed by a finger (for example, a thumb) when a user holds the syringe 3 between two fingers (for example, an index finger and a middle finger) and places the fingers on the finger hook portion 47 to push the plunger 5 into the syringe 3. As shown in FIG. 9D, the pressing portion 67 has an outer peripheral shape that is an ellipse elongated in the thickness direction Z, and two rod-shaped portions 69, 69' are arranged side by side in the width direction Y at the center of the thickness direction Z. As a result, in the plunger body 13 of this embodiment, the outer peripheral shape of the pressing portion is an ellipse elongated in the width direction Y, and compared to a plunger body in which the two rod-shaped portions 69, 69' are arranged side by side in the width direction Y at the center of the thickness direction Z, a difference is unlikely to occur between the position where the force is concentrated when the user presses the pressing portion 67 and each of the two rod-shaped portions 69, 69'. Therefore, the force of the user pressing the pressing portion 67 is easily transmitted to each of the rod-shaped portions 69, 69' approximately evenly, and the plunger body 13 of this embodiment can make the amount of paste discharged from the paste storage chamber 49 and the amount of paste discharged from the paste storage chamber 49' approximately even. Furthermore, the bottom surface of the pressing portion 67 is curved in the direction in which the rod-shaped portions 69, 69' extend so that the user can easily press the pressing portion 67 with his / her finger.

[0053] The rod-shaped portions 69, 69' are rod-shaped portions extending in parallel from the pressing portion 67 along the longitudinal direction X. In this embodiment, the rod-shaped portions 69, 69' are arranged at a predetermined interval along the long axis direction (width direction Y) of the pressing portion 67, and are inserted simultaneously into the paste storage chambers 49, 49', respectively. Here, the rod-shaped portions 69 and 69' have the same shape, and both can be inserted into both the paste storage chambers 49, 49'. In other words, when the rod-shaped portion 69 is inserted into the paste storage chamber 49, the rod-shaped portion 69' is inserted into the paste storage chamber 49', and when the rod-shaped portion 69 is inserted into the paste storage chamber 49', the rod-shaped portion 69' is inserted into the paste storage chamber 49.

[0054] As shown in FIG. 10, the cross-sectional shape of the rod-shaped portion 69 in the width direction Y is formed in a cross shape composed of a combination of a thickness direction wall portion 71A extending in the thickness direction Z and a width direction wall portion 71B extending in the width direction Y. The length dimension α in the thickness direction Z of the thickness direction wall portion 71A is larger than the length dimension β in the width direction Y of the width direction wall portion 71B. When the rod-shaped portion 69 is inserted into the paste storage chamber 49 (49'), the intersection position of the thickness direction wall portion 71A and the width direction wall portion 71B is located at the center of the paste storage chamber 49 (49'). Furthermore, the length dimension α in the thickness direction Z of the thickness direction wall portion 71A is set to be slightly shorter than the maximum length in the major axis direction LA of the paste storage chamber 49 (49'), and the length dimension β in the width direction Y of the width direction wall portion 71B is set to be slightly shorter than the maximum length in the minor axis direction SA of the paste storage chamber 49 (49'). As a result, when the rod-shaped portion 69 is inserted into the paste storage chamber 49 (49'), the tip of the thickness direction wall portion 71A lies along the inner curved surface portions 65, 65' of the paste storage chamber 49 (49'), and the tip of the width direction wall portion 71B lies along the inner flat surface portions 63, 63' of the paste storage chamber 49 (49').

[0055] 9A, the rod-shaped portion 69 has a pair of protrusions 73, 73 formed to protrude in the width direction Y and a pair of hollowed-out portions 75, 75 at one end of the width direction wall portion 71B in the longitudinal direction X. As a result, when the rod-shaped portion 69 is inserted into the paste storage chamber 49 (49'), the pair of protrusions 73, 73 of the width direction wall portion 71B contact the inner flat surface portion 63, 63', and the portion where the pair of hollowed-out portions 75, 75 are formed is bent. As a result, the rod-shaped portion 69 is positioned in the width direction Y, and rattling is prevented. Similarly, in order to prevent rattling of the rod-shaped portion 69, a plurality of protrusions 77 are formed at a predetermined interval in the longitudinal direction X at the respective tips of the thickness direction wall portion 71A and the width direction wall portion 71B.

[0056] The rod-shaped portion 69 has a holder engagement portion 79 formed at its tip with which the elastic holder 15 is loosely engaged. The holder engagement portion 79 has a tip wall portion 79A that contacts the bottom surface 81A of the elastic holder 15, and an engagement protrusion 79B that extends from the tip wall portion 79A in the longitudinal direction X and is inserted into an engagement hole 81B formed in the bottom surface 81A of the elastic holder 15. As shown in FIG. 9C, the tip wall portion 79A has an outer peripheral shape that is an ellipse shape that follows the cross-sectional shape of the paste storage chamber 49 (49'). When the rod-shaped portion 69 is inserted into the paste storage chamber 49 (49'), if the protrusions 73, 73 and the protrusion 77 pass over the removal prevention protrusion 55 (55'), the removal prevention protrusion 55 (55') gets caught on the protrusion 73, etc., to prevent the plunger 5 from falling off.

[0057] The rod-shaped portion 69 is provided with a plurality of reinforcing ribs 78 at predetermined intervals along the longitudinal direction X to reinforce the rod-shaped portion 69. In this embodiment, the reinforcing ribs 78 are provided in the form of five reinforcing ribs 78, namely, a first reinforcing rib 78A, a second reinforcing rib 78B, a third reinforcing rib 78C, a fourth reinforcing rib 78D, and a fifth reinforcing rib 78E, in that order from the tip side of the rod-shaped portion 69. Each of the first reinforcing rib 78A to the fifth reinforcing rib 78E is formed across the gap between the thickness direction wall portion 71A and the width direction wall portion 71B. As a result, the cross-sectional shape perpendicular to the longitudinal direction X of each of the first reinforcing rib 78A to the fifth reinforcing rib 78E is smaller than the cross-sectional shape perpendicular to the longitudinal direction X of the paste storage chamber 49, and is similar to the cross-sectional shape of the paste storage chamber 49.

[0058] In this embodiment, the first reinforcing rib 78A is formed at a position 9 mm away from the tip wall portion 79A. The second reinforcing rib 78B is formed at a position 27.6 mm away from the tip wall portion 79A. The third reinforcing rib 78C is formed at a position 41.2 mm away from the tip wall portion 79A. The fourth reinforcing rib 78D is formed at a position 54.7 mm away from the tip wall portion 79A. The fifth reinforcing rib 78E is formed at a position 64.7 mm away from the tip wall portion 79A. That is, when the distance between the second reinforcing rib 78B and the third reinforcing rib 78C is taken as a reference, the distance between the first reinforcing rib 78A and the second reinforcing rib 78B is slightly longer, the distance between the third reinforcing rib 78C and the fourth reinforcing rib 78D is almost the same, and the distance between the fourth reinforcing rib 78D and the fifth reinforcing rib 78E is shorter.

[0059] As described later, each of the second reinforcing rib 78B to the fifth reinforcing rib 78E also functions as an indicator that shows the remaining amount of paste in the paste storage chamber 49 when the rod-shaped portion 69 is inserted into the paste storage chamber 49.

[0060] Since the rod-shaped portion 69' has the same configuration as the rod-shaped portion 69, the reference numerals of the respective parts of the rod-shaped portion 69 are followed by "", and the description thereof will be omitted.

[0061] [Elastic holder] FIG. 11A is a perspective view of the elastic body holder 15, and FIG. 11B is a bottom view.

[0062] The elastic holder 15 is loosely engaged with the holder engaging parts 79, 79' at the tip of the plunger main body 13, one by one, and constitutes the tip of the plunger 5. The elastic holder 15 has a body 81, a top 83, and a neck 85. The body 81 is a part whose cross section in the width direction Y is elliptical. The bottom surface 81A of the body 81 is formed with an engaged hole 81B into which the engaging protrusion 79B of the holder engaging part 79 or the engaging protrusion 79B' of the holder engaging part 79' is inserted. The outer peripheral surface 81C of the body 81 has an elliptical shape that follows the elliptical shape of the inner peripheral surface (inner flat surface parts 63, 63' and inner curved surface parts 65, 65') of the paste storage chamber 49 (49'). The top part 83 has a shape that becomes narrower toward the tip. The neck part 85 is an elliptical part formed between the body 81 and the top part 83. The neck portion 85, and the body portion 81 and the top portion 83 that face each other across the neck portion 85, form an annular groove portion 81D in which the O-ring 17 is attached.

[0063] The elliptical shape of the body 81 is smaller than the cross-sectional shape of the paste storage chamber 49 (49'), and is similar to the cross-sectional shape of the paste storage chamber 49 (49'), and follows the elliptical shape of the inner peripheral surface of the paste storage chamber 49 (49'). Therefore, when the elastic holder 15 is inserted into the paste storage chamber 49 (49'), the distance from the outer peripheral surface 81C of the body 81 to the inner peripheral surface of the paste storage chamber 49 (49') is constant over the entire circumference of the body 81. In addition, in this embodiment, similar to the paste storage chamber 49 (49'), the length dimension T2 in the major axis direction of the elliptical shape of the body 81 is preferably within a range of 1.1 to 2.0, assuming that the length dimension W2 in the minor axis direction is 1. Specifically, in this embodiment, the length dimension T2 in the major axis direction is set to 1.3, assuming that the length dimension W2 in the minor axis direction is 1.

[0064] The elliptical shape of the neck portion 85 is smaller than that of the body portion 81, and has a cross-sectional shape similar to that of the body portion 81. In other words, the elliptical shape of the neck portion 85 has a cross-sectional shape similar to that of the paste storage chamber 49 (49'). Therefore, when the elastic body holder 15 is inserted into the paste storage chamber 49 (49'), the distance from the outer peripheral surface 85C of the neck portion 85 to the inner peripheral surface of the paste storage chamber 49 (49') is constant over the entire circumference of the neck portion 85. In addition, in this embodiment, the ratio of the length dimension in the major axis direction to the length dimension in the minor axis direction of the elliptical shape of the neck portion 85 is set to the same ratio as that of the elliptical shape of the body portion 81.

[0065] FIG. 12 is a cross-sectional view of the elastic holder 15 with the O-ring 17 attached to the annular groove 81D, cut in the width direction Y perpendicular to the longitudinal direction X at the neck portion 85. Here, the O-ring 17 is annular, but the neck portion 85 has an elliptical shape. Therefore, when the O-ring 17 is attached to the annular groove 81D, it is stretched in the major axis direction (thickness direction Z) and becomes elliptical. The length dimension T3 of the O-ring 17 in the major axis direction is larger than the length dimension T2 of the elliptical shape of the body portion 81 in the major axis direction. In addition, the length dimension W3 of the O-ring 17 in the minor axis direction is larger than the length dimension W2 of the elliptical shape of the body portion 81 in the minor axis direction. Therefore, the O-ring 17 is fixed in a state where it protrudes from the annular groove 81D.

[0066] Furthermore, a stronger tensile force acts on the region a of the O-ring 17 that is stretched in the long axis direction (thickness direction Z) than on the region b that is not stretched in the long axis direction (thickness direction Z). As a result, as shown in FIG. 12, the wire diameter ΔA of the O-ring 17 in the region a becomes thinner than the wire diameter ΔB in the region b, and the wire diameter of the O-ring 17 varies depending on the circumferential position. Note that the "wire diameter of the O-ring 17" refers to the cross-sectional thickness of the O-ring 17. Since the wire diameter of the O-ring 17 varies depending on the circumferential position, the amount of protrusion of the O-ring 17 from the annular groove portion 81D varies, and the thinner the wire diameter (e.g., region a), the less the protrusion from the annular groove portion 81D.

[0067] Furthermore, the length dimension T3 in the major axis direction of the elliptical O-ring 17 is slightly larger than the length dimension T1 in the major axis direction of the elliptical shape of the inner peripheral surface of the paste storage chamber 49 or the paste storage chamber 49'. Furthermore, the length dimension W3 in the minor axis direction of the elliptical O-ring 17 is slightly larger than the length dimension W1 in the minor axis direction of the elliptical shape of the inner peripheral surface of the paste storage chamber 49 or the paste storage chamber 49'. Therefore, when the elastic body holder 15 is inserted into the paste storage chamber 49 (49') of the syringe 3, the O-ring 17 comes into contact with the inner peripheral surface of the paste storage chamber 49 (49') and is compressed by being sandwiched between the inner peripheral surface of the paste storage chamber 49 (49') and the outer peripheral surface 85C of the neck portion 85.

[0068] 13 is a cross-sectional view (schematic view) of the elastic holder 15 with the O-ring 17 attached to the annular groove 81D, cut in the width direction Y perpendicular to the longitudinal direction X at the neck portion 85 in a state where the elastic holder 15 is inserted into the paste storage chamber 49 of the syringe 3, and a cross-sectional view (schematic view) of the elastic holder 15 as viewed from the front and side directions. In FIG. 13, the part of the O-ring 17 that protrudes from the annular groove 81D and is compressed by being inserted into the paste storage chamber 49 is shown in gray, and the state of the O-ring 17 before being compressed is shown by a dashed line.

[0069] 13, when the plunger 5 is inserted into the syringe 3 with the O-ring 17 attached to the annular groove 81D, the O-ring 17 is sandwiched and compressed between the inner circumferential surface (the inner flat surface portions 63, 63' and the inner curved surface portions 65, 65') of the paste storage chamber 49 and the outer circumferential surface 85C of the neck portion 85. Here, the wire diameter of the O-ring 17 varies depending on the circumferential position, and the thinner the wire diameter, the less the protrusion from the annular groove 81D.

[0070] 13, the difference (ΔX1, ΔX2) between the distance Gd from the outer peripheral surface 85C of the neck portion 85 to the inner peripheral surface of the paste storage chamber 49 and the wire diameter Wr of the O-ring 17 varies depending on the circumferential position of the O-ring 17. Therefore, the compression rate of the O-ring 17 when inserted into the paste storage chamber 49 varies depending on the circumferential position.

[0071] That is, in the elliptical O-ring 17, the region b with a thick wire diameter protrudes more from the annular groove portion 81D than the region a with a thin wire diameter, and the difference ΔX2 in the region b is larger than the difference ΔX1 in the region a. Therefore, when the O-ring 17 is inserted into the syringe 3, the region b of the O-ring 17 is pressed more toward the inside of the paste storage chamber 49 than the region a, and the compression ratio in the region b is larger than the compression ratio in the region a. As a result, the compression ratio in the major axis direction (thickness direction Z) of the elliptical O-ring 17 is larger than the compression ratio in the minor axis direction (width direction Y) of the O-ring 17.

[0072] Since the compression rate of the O-ring 17 varies depending on the circumferential position, the frictional force generated between the O-ring 17 and the inner peripheral surface of the paste storage chamber 49 (49') varies depending on the circumferential position of the O-ring 17. That is, the frictional force between the apex 17A in the major axis direction of the O-ring 17 stretched into an elliptical shape and the inner peripheral surface of the paste storage chamber 49 (49') is greater than the frictional force between the apex 17B in the minor axis direction of the O-ring 17 stretched into an elliptical shape and the inner peripheral surface of the paste storage chamber 49 (49'). Therefore, by adjusting the major axis direction dimension of the elliptical shape that is the cross-sectional shape of the paste storage chamber 49 (49') and the elliptical shape that is the cross-sectional shape of the plunger 5 relative to the minor axis direction dimension, it is easy to adjust the ease of movement of the plunger 5 in the longitudinal direction while maintaining the sealing performance between the inner peripheral surface of the paste storage chamber 49 (49') and the elastic body (O-ring 17).

[0073] It is also preferable that the compression ratio of O-ring 17 in the long axis direction (compression ratio in region b) is about 10 to 14%, and the compression ratio in the short axis direction (compression ratio in region a) is about 3 to 7%. Specifically, in this embodiment, the compression ratio in the long axis direction is 12%, and the compression ratio in the short axis direction is 5%. The compression ratio C (%) is calculated by the following formula: C = (Wr-Gd) / Wr x 100 however, Wr: Wire diameter of elastic body (O-ring) [mm] Gd: Distance from the outer periphery of the neck to the inner periphery of the paste storage chamber [mm]

[0074] The elastic holder 15 is loosely engaged with the holder engagement portion 79 (79') at the tip of the plunger body 13. Therefore, when the elastic holder 15 is inserted into the paste storage chamber 49 (49') of the syringe 3 together with the plunger body 13 with the O-ring 17 attached, the plunger body 13 is pushed in, and the elastic holder 15 moves in the longitudinal direction X together with the plunger body 13 in the paste storage chamber 49 (49'). On the other hand, when the plunger body 13 is pulled back, the elastic holder 15 is separated from the plunger body 13 and is left behind in the paste storage chamber 49 (49'). This prevents air from being drawn into the paste storage chamber 49 (49') from the outlet 51, (51') even if the plunger 5 is pulled back by mistake.

[0075] [Static Mixer] (Mixing tip body) Fig. 14A is a perspective view of the mixing tip body 19, and Fig. 14B is a bottom view thereof, and Fig. 15 is a cross-sectional view taken along line XV-XV shown in Fig. 14B.

[0076] The mixing tip body 19 is a member that, in combination with the mixer housing 21, constitutes the inner member IM of the static mixer 7, which is the mounting member M. The mixing tip body 19 includes a base 87, two insertion portions 89, 89', a pair of rotational engagement pieces 91, 91', a backflow prevention wall 35, and an element group 39.

[0077] The base 87 is a cylindrical portion that fits inside the mixer exterior body 23, which is the exterior body OM. A flange portion 87C extending radially outward is formed on the outer periphery of the base 87. The mixing tip main body 19 is fixed to the mixer exterior body 23 in a relatively rotatable state about the central axis CA by fitting the flange portion 87C into a groove (circumferential groove 103) formed on the inner periphery of the mixer exterior body 23, which will be described later.

[0078] The two insertion portions 89, 89' and the pair of rotary engagement pieces 91, 91' are formed on a first end surface 87A of the base 87 facing the syringe 3, and extend from the first end surface 87A in the longitudinal direction X. When the static mixer 7 is attached to the syringe 3, the two insertion portions 89, 89' are inserted into the two protrusions 43, 43' of the syringe 3, respectively. A paste passage 29 is formed inside the insertion portion 89, and a paste passage 29' is formed inside the insertion portion 89'. The pair of rotary engagement pieces 91, 91' are portions that respectively engage with engagement grooves (a pair of first engagement grooves 105A, 105A' or a pair of second engagement grooves 105B, 105B') of the mixer exterior body 23 described below.

[0079] The backflow prevention wall 35 extends along the central axis CA from the center of the second end face 87B opposite to the first end face 87A of the base 87. The tip of the backflow prevention wall 35 is the paste joining position JP, and the element group 39 extends from the tip of the backflow prevention wall 35. The element group 39 is made up of a plurality of elements (eight in this embodiment) lined up along the central axis CA.

[0080] The paste passage 29 is formed to continuously penetrate the insertion portion 89 and the base portion 87. The inflow hole 29A is formed in the end face of the insertion portion 89, and the outflow hole 29B is formed in the second end face 87B of the base portion 87. Similarly, the paste passage 29' is formed to continuously penetrate the insertion portion 89' and the base portion 87. The inflow hole 29A' is formed in the end face of the insertion portion 89', and the outflow hole 29B' is formed in the second end face 87B of the base portion 87.

[0081] As described above, the inner peripheral surface of the paste passage 29 has a distal surface 29C that is far from the central axis CA and a proximal surface 29D that is close to the central axis CA when viewed in a cross section perpendicular to the thickness direction Z. The angle θ between the distal surface 29C and a straight line C1 that passes through the center point of the inlet hole 29A and extends in the longitudinal direction X is set to 45° here.

[0082] (Mixer housing) Fig. 16A is a perspective view of the mixer housing 21, and Fig. 16B is a bottom view thereof, and Fig. 17 is a cross-sectional view taken along line XVII-XVII shown in Fig. 16B.

[0083] The mixer housing 21 is a member that, in combination with the mixing tip main body 19, constitutes the inner member IM of the static mixer 7, which is the mounting member M. The mixer housing 21 includes a base housing portion 93 and an element housing portion 37.

[0084] The base housing portion 93 includes a circular end wall portion 93A that covers the second end face 87B of the base 87 of the mixing tip main body portion 19 when the mixer housing 21 is placed over the mixing tip main body portion 19, and a peripheral wall portion 93B that rises from the edge of the end wall portion 93A, surrounds the base 87, and extends until its tip contacts the flange portion 87C.

[0085] A recess 93C is provided on the inner wall of the end wall portion 93A at a position opposite the outlet holes 29B, 29B'. By covering the mixing tip body 19 with the mixer housing 21, an intermediate passage 31 is formed inside the inner member IM, which is partitioned by the base 87, the backflow prevention wall 35, and the recess 93C (see FIG. 3).

[0086] The element housing portion 37 is a cylindrical portion with an open tip, extending in the longitudinal direction X from a through hole formed in the center of the end wall portion 93A of the base housing portion 93. When the mixer housing 21 is placed over the mixing tip body 19, the element housing portion 37 has an element group 39 inserted therein to form a mixing passage 33. A guide tip engagement groove 37A for fixing the guide tip 9 is formed on the outer periphery of the element housing portion 37.

[0087] (Mixer exterior body) Fig. 18A is a front view of mixer exterior body 23, Fig. 18B is a side view, Fig. 18C is a plan view, and Fig. 18D is a bottom view. In addition, Fig. 19 is a cross-sectional view taken along line XIX-XIX shown in Fig. 18C, Fig. 20 is a cross-sectional view taken along line XX-XX shown in Fig. 18C, and Fig. 21 is a cross-sectional view taken along line XXI-XXI shown in Fig. 18A.

[0088] The mixer exterior body 23 is a cylindrical member that constitutes the exterior body OM of the static mixer 7, which is the mounting member M. The static mixer 7, which is the mounting member M, is constituted by storing an inner member IM consisting of a mixing tip main body 19 and a mixer housing 21 inside the mixer exterior body 23. In addition, the mixer exterior body 23 rotates relatively to the syringe 3 about a central axis CA.

[0089] The mixer exterior body 23 includes a top wall portion 95 having a regular hexagonal outer peripheral shape, a first peripheral wall portion 97 rising from the edge of the top wall portion 95, and a second peripheral wall portion 99 extending continuously from the first peripheral wall portion 97 via a step. Inside the mixer exterior body 23, a first space S1 surrounded by the top wall portion 95 and the first peripheral wall portion 97 and a second space S2 surrounded by the second peripheral wall portion 99 are formed (see FIGS. 19 and 20). An inner member IM consisting of a mixing tip main body portion 19 and a mixer housing 21 is fitted in the first space S1 in a state in which it can rotate around a central axis CA. In addition, the tip portion of the syringe 3 (one end portion 41A of the syringe main body 41) is inserted into the second space S2 with the inner member IM housed therein (see FIG. 3).

[0090] The top wall 95 is a portion that covers the end wall 93A of the mixer housing 21, and faces the opening into which the syringe 3 is inserted (see FIG. 3). A top penetrating tube 101 for exposing the element housing portion 37 to the outside is formed in the center of the top wall 95. The top penetrating tube 101 is a cylindrical portion that protrudes from the top wall 95 and penetrates the top wall 95. When the inner member IM consisting of the mixing tip main body 19 and the mixer housing 21 is stored in the mixer exterior body 23, the element housing portion 37 penetrates the top penetrating tube 101. In addition, an arrow AR1 indicating the position of a dent 107A described later is engraved on the surface of the top wall 95 (see FIG. 16B). In addition, the dent 107A is one of the engaged portions 107 described later.

[0091] When viewed along the central axis CA, the first peripheral wall portion 97 has an outer peripheral surface that is a regular hexagon as shown in Fig. 18C. When viewed along the central axis CA, the first peripheral wall portion 97 has an inner peripheral surface that is a circle as shown in Fig. 18D. The inner peripheral surface of the first peripheral wall portion 97 is formed with a circumferential groove 103, a pair of first engaged grooves 105A, 105A', and a pair of second engaged grooves 105B, 105B'.

[0092] As shown in FIG. 3, the circumferential groove 103 is a recess into which the flange portion 87C of the mixing tip body 19 fits, and extends in the circumferential direction (the rotation direction of the inner member IM).

[0093] The first engaged groove 105A and the second engaged groove 105B on one side are recesses with which one of the rotary engaging pieces 91 engages. The first engaged groove 105A' and the second engaged groove 105B' on the other side are recesses with which the other of the rotary engaging pieces 91' engages. The pair of first engaged grooves 105A, 105A' and the pair of second engaged grooves 105B, 105B' are arranged side by side in the circumferential direction (the rotation direction of the inner member IM) with a predetermined interval therebetween. Here, the pair of first engaged grooves 105A, 105A' are formed at positions facing each other in the thickness direction Z across the central axis CA. The pair of second engaged grooves 105B, 105B' are formed at positions facing each other in a direction shifted in the circumferential direction from the thickness direction Z across the central axis CA.

[0094] When assembled into the static mixer 7, the mixing tip body 19 and the mixer housing 21 rotate relative to the mixer exterior body 23 around the central axis CA. At this time, depending on the positional relationship in the rotational direction between the mixing tip body 19 and the mixer housing 21 and the mixer exterior body 23, one rotating engagement piece 91 engages with either the first engaged groove 105A or the second engaged groove 105B on one side, and the other rotating engagement piece 91' engages with either the first engaged groove 105A' or the second engaged groove 105B' on the other side. This determines the relative rotational position of the mixing tip body 19 and the mixer housing 21 and the mixer exterior body 23.

[0095] When viewed along the central axis CA, the second peripheral wall portion 99 has an outer peripheral surface that curves in an arc shape centered on the central axis CA and has a teardrop shape that is partially pointed outward, as shown in FIG. 18C. The pointed portion of the outer peripheral surface of the second peripheral wall portion 99 is a sharpened portion 99a, and the tip of the sharpened portion 99a coincides with the direction indicated by the arrow AR1 formed on the top wall portion 95. The sharpened portion 99a is also formed with a protrusion 99b that protrudes along the central axis CA from an end surface 99B of the second peripheral wall portion 99 (the opening of the mixer exterior body 23 into which the syringe 3 is inserted). Therefore, the protrusion 99b is formed at a position that coincides with the position at which the recess 107A, which is one of the engaged portions 107, is formed in the circumferential direction centered on the central axis CA.

[0096] The inner peripheral surface of the second peripheral wall portion 99 is formed with a step portion 98, a second step portion 98A, and an engaged portion 107 constituted by three recesses 107A, 107B, and 107C.

[0097] The step portion 98 is formed at the boundary between the first peripheral wall portion 97 and the second peripheral wall portion 99, and is a stepped unevenness that narrows the inner diameter of the mixer outer casing 23 toward the top wall portion 95. The step portion 98 extends in the circumferential direction (the rotation direction of the inner member IM), and when the static mixer 7 is attached to the tip of the syringe 3, the circular wall portion 41a of the syringe 3 abuts against the step portion 98 (see FIG. 3).

[0098] The second step portion 98A is a stepped unevenness that narrows the inner diameter of the mixer exterior body 23 toward the top wall portion 95, and is formed at a position closer to an end face 99B of the second peripheral wall portion 99 than the step portion 98. The second step portion 98A extends in the circumferential direction (the rotation direction of the inner member IM), and when the static mixer 7 is attached to the tip of the syringe 3, the second step portion 98A abuts against a step portion 49c formed on the outer peripheral surface of the paste storage chambers 49, 49' of the syringe 3 (see FIG. 3).

[0099] In addition, the engaged portion 107 constitutes an engagement structure that fixes the mounting member M to the tip portion of the syringe 3 (one end portion 41A of the syringe body 41), and is the portion that engages with the engagement portion 45 (three protrusion pieces 45A, 45B, 45C) of the syringe 3.

[0100] The recesses 107A, 107B, and 107C have first grooves 107Aa, 107Ba, and 107Ca, and second grooves 107Ab, 107Bb, and 107Cb, respectively. In addition, windows 109A, 109B, and 109C penetrating the second peripheral wall 99 are formed at positions corresponding to the second grooves 107Ab, 107Bb, and 107Cb, respectively. That is, the second grooves 107Ab, 107Bb, and 107Cb are formed by the edges of the windows 109A, 109B, and 109C. The first grooves 107Aa, 107Ba, and 107Ca open to the second step 98A and extend to the step 98 along the longitudinal direction X (center axis CA).

[0101] The recesses 107A, 107B, and 107C are arranged along the rotation direction of the mixer exterior body 23, and are asymmetrical about the central axis CA, which is the center of rotation of the mixer exterior body 23, when viewed along the central axis CA. The recesses 107A, 107B, and 107C are arranged at unequal intervals along the rotation direction of the mixer exterior body 23. That is, the recess 107A is formed at a position on the inner circumferential surface of the second peripheral wall portion 99 that corresponds to a corner portion of the outer circumferential surface of the first peripheral wall portion 97 when viewed along the central axis CA. The recesses 107B and 107C are formed at a position on the inner circumferential surface of the second peripheral wall portion 99 that corresponds to a flat portion of the outer circumferential surface of the first peripheral wall portion 97 when viewed along the central axis CA (see FIG. 18D and FIG. 21). Further, recess 107A has a shape into which protrusion 45A serving as engaging portion 45 can be inserted, recess 107B has a shape into which protrusion 45B serving as engaging portion 45 can be inserted, and recess 107C has a shape into which protrusion 45C serving as engaging portion 45 can be inserted. Recesses 107A, 107B, and 107C have different shapes when viewed along central axis CA.

[0102] Furthermore, the mixer exterior body 23 is formed with a cylindrical wall portion 98B that rises from the edge of the second step portion 98A along the central axis CA and forms an opening of the mixer exterior body 23. The cylindrical wall portion 98B is a cylindrical wall surface that surrounds the periphery of the step portion 49c formed on the outer circumferential surface of the paste storage chamber 49, 49' when the static mixer 7 is attached to the tip of the syringe 3. As the cylindrical wall portion 98B rises from the edge of the second step portion 98A, the first groove portions 107Aa, 107Ba, and 107Ca are each opened inside the cylindrical wall portion 98B. That is, the cylindrical wall portion 98B protrudes along the central axis CA beyond the engaged portion 107.

[0103] [cap] The cap 11 is fixed to the tip of the syringe 3 (one end 41A of the syringe body 41) in place of the static mixer 7 during storage or transportation of the paste injector 1. The same component names are used for components common to the static mixer 7, and descriptions thereof may be omitted.

[0104] (Inner cap component) Fig. 22A is a perspective view of the cap inner member 25, and Fig. 22B is a bottom view thereof, and Fig. 23 is a cross-sectional view taken along line XXIII-XXIII shown in Fig. 22B.

[0105] The cap inner member 25 is a member that constitutes the inner member IM of the cap 11 that is the mounting member M, and is a member that corresponds to the mixing tip main body 19 and the mixer housing 21 that are the inner member IM of the static mixer 7.

[0106] The cap inner member 25, like the mixing tip body 19, includes a base portion 111, two insertion portions 113, 113', and a pair of rotational engagement pieces 115, 115'.

[0107] The base 111 is a cylindrical portion that fits inside the cap exterior body 27, which is the exterior body OM. A flange portion 117C extending radially outward is formed on the outer periphery of the base 111. The cap inner member 25 is fixed to the cap exterior body 27 in a relatively rotatable state about the central axis CA by fitting the flange portion 117C into a groove (circumferential groove 125) formed on the inner periphery of the cap exterior body 27, which will be described later.

[0108] The two insertion parts 113, 113' and the pair of rotation engagement pieces 115, 115' are formed on a first end surface 111A of the base 111 facing the syringe 3, and extend from the first end surface 111A in the longitudinal direction X. When the cap 11 is attached to the syringe 3, the two insertion parts 113, 113' are inserted into the two protrusions 43, 43' of the syringe 3, respectively. Unlike the case of the mixing tip main body 19, the insertion parts 113, 113' have a columnar shape for sealing the outlets 51, 51' of the syringe 3, and no passage is formed inside. The pair of rotation engagement pieces 115, 115' are parts that respectively engage with the engagement grooves (a pair of first engagement grooves 127A, 127A' or a pair of second engagement grooves 127B, 127B') of the cap exterior body 27 described later.

[0109] A pair of bottomed recesses 117, 117 are formed on a second end surface 111B of the base 111 opposite to the first end surface 111A.

[0110] (Cap exterior body) Fig. 24A is a front view of cap exterior body 27, Fig. 24B is a side view, Fig. 24C is a plan view, and Fig. 24D is a bottom view. Also, Fig. 25 is a cross-sectional view taken along line XXV-XXV shown in Fig. 24C, Fig. 26 is a cross-sectional view taken along line XXVI-XXVI shown in Fig. 24C, and Fig. 27 is a cross-sectional view taken along line XXVII-XXVII shown in Fig. 24C.

[0111] The cap exterior body 27 is a cylindrical member constituting the exterior body OM of the cap 11 which is the mounting member M, and is a member corresponding to the mixer exterior body 23 which is the exterior body OM of the static mixer 7. The cap inner member 25 is stored inside the cap exterior body 27 to form the cap 11 which is the mounting member M. In addition, the cap exterior body 27 rotates relatively to the syringe 3 about the central axis CA.

[0112] The cap exterior body 27 includes a top wall portion 119 having a regular hexagonal outer peripheral shape, a first peripheral wall portion 121 rising from an edge of the top wall portion 119, and a second peripheral wall portion 123 extending continuously from the first peripheral wall portion 121 via a step. Inside the cap exterior body 27, a first space S1 surrounded by the top wall portion 119 and the first peripheral wall portion 121, and a second space S2 surrounded by the second peripheral wall portion 123 are formed (see Figs. 25 and 26). An inner member IM made of the cap inner member 25 is fitted into the first space S1 in a state in which it can rotate around the central axis CA. In addition, a tip portion (one end portion 41A of the syringe body 41) a of the syringe 3 is inserted into the second space S2 with the inner member IM housed therein.

[0113] The top wall 119 is a portion that closes the first space S1. Unlike the mixing tip body 19, the top wall 119 is made of a curved plate member, and does not have a top through-cylinder formed in the center. In addition, an arrow AR1 indicating the position of a recess 129A (described later) is engraved on the surface of the top wall 119 (see FIG. 24C).

[0114] When viewed along the central axis CA, the outer peripheral surface of the first peripheral wall portion 121 has a regular hexagonal shape as shown in Fig. 24C. When viewed along the central axis CA, the inner peripheral surface of the first peripheral wall portion 121 has a circular shape as shown in Fig. 24D. The inner peripheral surface of the first peripheral wall portion 121 is formed with a circumferential groove 125, a pair of first engaged grooves 127A, 127A', and a pair of second engaged grooves 127B, 127B'.

[0115] The circumferential groove 125 is a recess into which the flange portion 117C of the cap inner member 25 fits, and extends in the circumferential direction (the rotation direction of the cap inner member 25).

[0116] The first engaged groove 127A and the second engaged groove 127B on one side are recesses with which one of the rotary engaging pieces 115 engages. The first engaged groove 127A' and the second engaged groove 127B' on the other side are recesses with which the other of the rotary engaging pieces 115' engages. The pair of first engaged grooves 127A, 127A' and the pair of second engaged grooves 127B, 127B' are arranged side by side in the circumferential direction (the rotation direction of the cap inner member 25) with a predetermined interval therebetween. Here, the pair of first engaged grooves 127A, 127A' are formed at positions facing each other in the thickness direction Z across the central axis CA. The pair of second engaged grooves 127B, 127B' are formed at positions facing each other in a direction shifted in the circumferential direction from the thickness direction Z across the central axis CA.

[0117] When assembled into the cap 11, the cap inner member 25 rotates relative to the cap exterior body 27 around the central axis CA. At this time, depending on the positional relationship in the rotational direction between the cap inner member 25 and the cap exterior body 27, one rotational engagement piece 115 engages with either the first engaged groove 127A or the second engaged groove 127B on one side, and the other rotational engagement piece 115' engages with either the first engaged groove 127A' or the second engaged groove 127B' on the other side. This determines the relative positions in the rotational direction between the cap inner member 25 and the cap exterior body 27.

[0118] When viewed along the central axis CA, the second peripheral wall portion 123 has an outer peripheral surface that curves in an arc shape centered on the central axis CA and has a teardrop shape that is partially pointed outward, as shown in FIG. 24C. The pointed portion of the outer peripheral surface of the second peripheral wall portion 123 is a sharpened portion 123a, and the tip of the sharpened portion 123a coincides with the direction indicated by the arrow AR1 formed on the top wall portion 119. In addition, the sharpened portion 123a is formed with a protrusion 123b that protrudes along the central axis CA from an end surface 123B of the second peripheral wall portion 123 (the opening of the cap exterior body 27 into which the syringe 3 is inserted). Therefore, the protrusion 123b is formed at a position that coincides with the position at which the recess 129A, which is one of the engaged portions 129, is formed in the circumferential direction centered on the central axis CA.

[0119] The inner peripheral surface of the second peripheral wall portion 123 is formed with a step portion 120, a second step portion 120A, and an engaged portion 129 constituted by three recesses 129A, 129B, and 129C.

[0120] Step portion 120 is formed at the boundary between first circumferential wall portion 121 and second circumferential wall portion 123, and is a stepped unevenness that narrows the inner diameter of cap exterior body 27 toward top wall portion 119. Step portion 120 extends in the circumferential direction (the rotation direction of inner member IM), and when cap 11 is attached to the tip of syringe 3, circular wall portion 41a of syringe 3 abuts against it.

[0121] The second step portion 120A is a stepped unevenness that narrows the inner diameter of the cap exterior body 27 toward the top wall portion 119, and is formed at a position closer to an end face 123B of the second circumferential wall portion 123 than the step portion 120. The second step portion 120A extends in the circumferential direction (the rotation direction of the inner member IM), and when the cap 11 is attached to the tip of the syringe 3, a step portion 49c formed on the outer circumferential surface of the paste storage chambers 49, 49' of the syringe 3 abuts against the second step portion 120A.

[0122] In addition, the engaged portion 129 constitutes an engagement structure that fixes the mounting member M to the tip portion of the syringe 3 (one end portion 41A of the syringe body 41), and is the portion that engages with the engagement portion 45 (three protrusion pieces 45A, 45B, 45C) of the syringe 3.

[0123] The recesses 129A, 129B, and 129C have first grooves 129Aa, 129Ba, and 129Ca, and second grooves 129Ab, 129Bb, and 129Cb, respectively. In addition, windows 131A, 131B, and 131C are formed at positions corresponding to the second grooves 129Ab, 129Bb, and 129Cb, respectively, penetrating the second peripheral wall 123. That is, the second grooves 129Ab, 129Bb, and 129Cb are formed by the edges of the windows 131A, 131B, and 131C. The first grooves 129Aa, 129Ba, and 129Ca are open to the second step 120A and extend to the step 120 along the longitudinal direction X (center axis CA).

[0124] The dents 129A, 129B, and 129C are arranged along the rotational direction of the cap exterior body 27, and are asymmetrical about the central axis CA, which is the center of rotation of the cap exterior body 27, when viewed along the central axis CA. The dents 129A, 129B, and 129C are arranged at unequal intervals along the rotational direction of the cap exterior body 27. That is, the dent 129A is formed at a position on the inner circumferential surface of the second circumferential wall portion 123 that corresponds to a corner portion of the outer circumferential surface of the first circumferential wall portion 121 when viewed along the central axis CA. The dents 129B and 129C are formed at positions on the inner circumferential surface of the second circumferential wall portion 123 that correspond to a flat portion of the outer circumferential surface of the first circumferential wall portion 121 when viewed along the central axis CA (see FIG. 24D and FIG. 27). Further, recess 129A has a shape into which protrusion 45A serving as engagement portion 45 can be inserted, recess 129B has a shape into which protrusion 45B serving as engagement portion 45 can be inserted, and recess 129C has a shape into which protrusion 45C serving as engagement portion 45 can be inserted. Recesses 129A, 129B, and 129C have different shapes from one another when viewed along central axis CA.

[0125] Furthermore, the cap exterior body 27 is formed with a cylindrical wall portion 120B that rises from the edge of the second step portion 120A along the central axis CA and forms an opening of the cap exterior body 27. The cylindrical wall portion 120B is a cylindrical wall surface that surrounds the periphery of the step portion 49c formed on the outer circumferential surface of the paste storage chamber 49, 49' when the cap 11 is attached to the tip of the syringe 3. As the cylindrical wall portion 120B rises from the edge of the second step portion 120A, the first groove portions 129Aa, 129Ba, and 129Ca are each opened inside the cylindrical wall portion 120B. That is, the cylindrical wall portion 120B protrudes along the central axis CA beyond the engaged portion 129.

[0126] [Details on how to secure the mounting parts] 28 and 29, the details of the process up to fixing the mounting member M to the syringe 3 will be described using the static mixer 7 as an example. Fig. 28 is a diagram showing the state prior to the stage where the static mixer 7 is placed over and fixed to the syringe 3. In Fig. 28, the bottom surface of the static mixer 7 is shown, and the syringe 3 is shown in plan view with the finger hook 47 omitted. In Figs. 28 and 29, the inner member IM is shown colored gray.

[0127] 28, before being fixed to the syringe 3, the static mixer 7 is in a state in which one rotating engagement piece 91 is engaged with one second engaged groove 105B, and the other rotating engagement piece 91' is engaged with the other second engaged groove 105B'. That is, the width direction Y of the mixer exterior body 23 and the width direction Y of the inner member IM do not coincide with each other. In this state, the circular wall portion 41a of the syringe 3 can be inserted into the second space S2 surrounded by the second peripheral wall portion 99 of the mixer exterior body 23 only when the positions of the first groove portions 107Aa, 107Ba, and 107Ca of the recesses 107A, 107B, and 107C face the three protruding pieces 45A, 45B, and 45C of the syringe 3, respectively. Only at this time does the protruding portion 43 of the syringe 3 face the insertion portion 89 of the mixing chip body 19 , and the protruding portion 43 ′ of the syringe 3 face the insertion portion 89 ′ of the mixing chip body 19 .

[0128] The user can align the protrusion 45A with the dent 107A by aligning the arrow AR1 on the surface of the top wall 95 with the protrusion 45A. As a result, the first groove 107Aa of the dent 107A faces the protrusion 45A, the first groove 107Ba of the dent 107B faces the protrusion 45B, the first groove 107Ca of the dent 107C faces the protrusion 45C, the insertion portion 89 faces the protrusion 43, and the insertion portion 89' faces the protrusion 43'.

[0129] In this embodiment, the second step portion 98A and the cylindrical wall portion 98B are formed at the opening of the mixer exterior body 23, and by using this, the projection piece 45 and the engaged portion 107 can also be aligned. That is, when the circular wall portion 41a of the syringe 3 is inserted into the mixer exterior body 23 without aligning the projection piece 45 and the engaged portion 107, the circular wall portion 41a of the syringe 3 comes into contact with the second step portion 98A and the cylindrical wall portion 98B and does not enter the second space S2. This makes it possible to align the central axis CA of the mixer exterior body 23 with the central axis CA of the syringe 3, and to engage the engaging portion 45 (the engaged portion 107) in a state in which the positional deviation between the two is suppressed. In this state, the mixer outer casing 23 can be rotated relative to the syringe 3 around the central axis CA to find the position where the circular wall portion 41a of the syringe 3 enters the second space S2 (i.e., the position where the protrusion piece 45A and the recess 107A, the protrusion piece 45B and the recess 107B, and the protrusion piece 45C and the recess 107C are aligned).

[0130] When the circular wall portion 41a of the syringe 3 is inserted into the second space S2, the insertion portion 89 is inserted into the protruding portion 43, and the insertion portion 89' is inserted into the protruding portion 43'. As a result, the rotational position of the inner member IM (the mixing tip main body 19 and the mixer housing 21) is fixed with respect to the syringe 3. The protruding piece 45A is inserted into the first groove portion 107Aa of the recess 107A and abuts against the step portion 98. The protruding piece 45B is inserted into the first groove portion 107Ba of the recess 107B and abuts against the step portion 98. The protruding piece 45C is inserted into the first groove portion 107Ca of the recess 107C and abuts against the step portion 98.

[0131] Then, in this state, when the mixer outer casing 23 rotates around the central axis CA, the inner member IM (the mixing tip main body 19 and the mixer housing 21) does not rotate, and only the mixer outer casing 23, which is the outer casing OM, rotates, resulting in the state shown in Figure 29.

[0132] FIG. 29 is a bottom view of the static mixer 7 after only the mixer exterior body 23 has rotated (the inserted syringe 3 is not shown). When only the mixer exterior body 23 has rotated, one of the rotary engagement pieces 91 engages with one of the first engaged grooves 105A, and the other rotary engagement piece 91' engages with the other first engaged groove 105A'. The protruding piece 45A enters the second groove 107Ab along the step portion 98 from the end of the first groove 107Aa and is exposed to the outside from the window portion 109A. The protruding piece 45B enters the second groove 107Bb along the step portion 98 from the end of the first groove 107Ba and is exposed to the outside from the window portion 109B. The protruding piece 45C enters the second groove 107Cb along the step portion 98 from the end of the first groove 107Ca and is exposed to the outside from the window portion 109C.

[0133] As a result, the protruding pieces 45A, 45B, and 45C are engaged with the recesses 107A, 107B, and 107C, respectively, and the static mixer 7 and the syringe 3 are fixed to each other.

[0134] [Paste remaining amount display using reinforcing ribs] 30 to 33 are cross-sectional views of the paste injector cut in the width direction Y at a position passing through the central axis CA extending in the longitudinal direction X. Using Figs. 30 to 33, it will be explained that the second reinforcing rib 78B to the fifth reinforcing rib 78E (78B' to 78E') formed on the rod-shaped portion 69 (69') also function as indicators that show the remaining amount of paste in the paste storage chambers 49, 49'. In Figs. 30 to 33, the reference numerals of the elastic holder and the O-ring engaged with the rod-shaped portion 69' are marked with "'".

[0135] The paste filled in the paste injector 1 is determined in advance for an approximate amount of paste to be used per use. In this embodiment, since the static mixer 7 is disposable, the amount of paste to be discharged to a desired position plus the amount of paste remaining in the paste flow paths (paste passage 29, paste passage 29', intermediate passage 31, and mixing passage 33) is set as the amount of paste to be used per use. When the paste injector 1 is shipped, the paste storage chambers 49, 49' of the syringe 3 are filled with different types of paste in advance for multiple uses, and the plunger 5 is inserted through the filling port 53, 53' of the syringe 3 and sealed (see FIG. 1). In this embodiment, when the paste injector 1 is shipped, the paste storage chambers 49, 49' are filled with paste for approximately 15 uses. Then, when the plunger 5 is pushed into the syringe 3, the elastic holder 15 (15') to which the O-ring 17 (17') is attached moves in the paste storage chamber 49 (49') toward the discharge port 51 (51'), and the paste is discharged from the paste storage chamber 49 (49'). At this time, as the use of the paste progresses, the plunger 5 moves in the syringe 3 toward the discharge port 51, 51', and the reinforcing rib 78 (78') overlapping with the filling port 53 (53') changes in the order of the second reinforcing rib 78B (78B'), the third reinforcing rib 78C (78C'), the fourth reinforcing rib 78D (78D'), and the fifth reinforcing rib 78E (78E'). In other words, the type of reinforcing rib 78 (78') overlapping with the filling port 53 (53') changes depending on the remaining amount of paste in the paste storage chamber 49 (49'). Therefore, the paste injector 1 of this embodiment can indicate the remaining amount of paste in the paste storage chamber 49 (49') by the reinforcing rib 78 (78') that exists at a position overlapping with the filling port 53 (53').

[0136] However, the amount of paste used per use varies depending on the user and the usage conditions, and is not strictly regulated. Therefore, in this embodiment, the remaining amount of paste indicated by the second reinforcing rib 78B to the fifth reinforcing rib 78E (78B' to 78E') overlapping with the filling port 53 (53') indicates the remaining amount as an approximate percentage.

[0137] In this embodiment, the remaining amount of paste when the fifth reinforcing rib 78E (78E') overlaps with the filling port 53 (53') is the amount of paste required for one use. That is, the paste injector 1 of this embodiment can indicate that the remaining amount of paste in the paste storage chamber 49 (49') is the amount of paste required for one use by overlapping the fifth reinforcing rib 78E (78E') with the filling port 53 (53'). When the fifth reinforcing rib 78E (78E') passes the position of the filling port 53 (53') and enters the paste storage chamber 49 (49'), the paste injector 1 has finished using the paste.

[0138] Specifically, in this embodiment, when the remaining amount of paste is about 75%, the second reinforcing rib 78B (78B') overlaps with the filling port 53 (53') (see FIG. 30). When the remaining amount of paste is about 50%, the third reinforcing rib 78C (78C') overlaps with the filling port 53 (53') (see FIG. 31). When the remaining amount of paste is about 25%, the fourth reinforcing rib 78D (78D') overlaps with the filling port 53 (53') (see FIG. 32). When the remaining amount of paste is enough for one use, the fifth reinforcing rib 78E (78E') is in a position overlapping with the filling port 53 (53') (see FIG. 33).

[0139] Thus, in the paste injector 1 of the present embodiment, when the second reinforcing rib 78B (78B') is present at a position overlapping the filling port 53 (53'), it can indicate that the remaining amount of paste is about 75% (see FIG. 30). Also, when the third reinforcing rib 78C (78C') is present at a position overlapping the filling port 53 (53'), it can indicate that the remaining amount of paste is about 50% (see FIG. 31). Also, when the fourth reinforcing rib 78D (78D') is present at a position overlapping the filling port 53 (53'), it can indicate that the remaining amount of paste is about 25% (see FIG. 32). Also, when the fifth reinforcing rib 78E (78E') is present at a position overlapping the filling port 53 (53'), it can indicate that the remaining amount of paste is one use amount (see FIG. 33).

[0140] The distance between the fourth reinforcing rib 78D (78D') and the fifth reinforcing rib 78E (78E') is shorter than the distance between the second reinforcing rib 78B (78B') and the third reinforcing rib 78C (78C') because the distance between the second reinforcing rib 78B (78B') and the third reinforcing rib 78C (78C') is 25% of 75% to 50% of the remaining amount of paste, whereas the distance between the fourth reinforcing rib 78D (78D') and the fifth reinforcing rib 78E (78E') is less than 25% of the remaining amount of paste to one use's amount of 25%.

[0141] <Function of the paste injector> The operation of the paste injector will now be described.

[0142] In the paste injector 1 of this embodiment, a plurality of reinforcing ribs 78 (78') (first reinforcing rib 78A to fifth reinforcing rib 78E (78A' to 78E')) are provided on the rod-shaped portion 69 (69') at predetermined intervals along the longitudinal direction X to reinforce the rod-shaped portion 69 (69'). Of these, the second reinforcing rib 78B to fifth reinforcing rib 78E (78B' to 78E') are formed at positions that overlap with the filling port 53 (53') when the remaining amount of paste in the paste storage chamber 49 (49') becomes a predetermined amount.

[0143] By providing the first to fifth reinforcing ribs 78A to 78E (78A' to 78E') in this manner, the first to fifth reinforcing ribs 78A to 78E (78A' to 78E') can reinforce the rod-shaped portion 69 (69'). In addition, the amount of paste remaining in the paste storage chamber 49 (49') can be known from the outside based on the positional relationship between the second to fifth reinforcing ribs 78B to 78E (78B' to 78E') and the filling port 53 (53'). In other words, the second to fifth reinforcing ribs 78B to 78E (78B' to 78E') can also serve as an indicator of the amount of remaining paste.

[0144] The positions at which the first to fifth reinforcing ribs 78A to 78E (78A' to 78E') are provided can be set arbitrarily. For example, if the amount of paste to be used at one time is specified in advance, the remaining amount of the paste may be shown as a percentage, or the remaining number of times that the paste can be used may be shown.

[0145] Also, for example, the fifth reinforcing rib 78E (78E') provided at the position closest to the pressing portion 67 may be formed at a position overlapping the filling port 53 (53') when the remaining amount of paste in the paste storage chamber 49 (49') is the amount of one use. In this way, the paste in the paste storage chamber 49, 49' is prevented from running out before the amount of paste required for treatment, etc. is discharged from the mixing tip or the guide tip attached to the tip thereof during the last use, and the user can use the paste injector 1 with peace of mind. The amount of paste used per use varies depending on the user and the usage conditions. Therefore, it is also possible to set the "amount of use per use", which is the remaining amount of paste when the fifth reinforcing rib 78E (78E') overlaps with the filling port 53 (53'), to an amount with a margin larger than the approximate amount of paste used per use that is determined in advance.

[0146] The cross-sectional shape of the multiple reinforcing ribs 78 (78') perpendicular to the longitudinal direction X may be smaller than the cross-sectional shape of the paste storage chamber 49 (49') perpendicular to the longitudinal direction X, and may be similar to the cross-sectional shape of the paste storage chamber 49 (49'). This allows the multiple reinforcing ribs 78 (78') to be configured large, reinforce the rod-shaped portion 69 (69'), and improve the visibility of the display showing the remaining amount of paste in the paste storage chamber 49 (49').

[0147] In the case where the cross-sectional shape of the rod-shaped portion 69 (69') perpendicular to the longitudinal direction X is formed in a cross shape including a thickness direction wall portion 71A (71A') extending in a thickness direction Z perpendicular to the longitudinal direction X and a width direction wall portion 71B (71B') extending in a width direction Y perpendicular to the longitudinal direction X and the thickness direction Z, the reinforcing ribs 78 (78') may be formed in a gap between the thickness direction wall portion 71A (71A') and the width direction wall portion 71B (71B'). In this way, the reinforcing ribs 78 (78') can reinforce the cross-shaped rod-shaped portion 69 (69'). In addition, since the reinforcing ribs 78 (78') are provided perpendicular to the cross-shaped rod-shaped portion 69 (69'), the reinforcing ribs 78 (78') can be easily viewed, and the visibility of the display indicating the remaining amount of paste in the paste storage chamber 49 (49') can be improved.

[0148] The plunger 5 has an elastic body holder 15 (15') loosely engaged with the tip of the rod-shaped portion 69 (69'), and the elastic body holder 15 (15') may be configured to separate from the rod-shaped portion 69 (69') when the plunger 5 is pulled back toward the filling port 53 (53') after the plunger 5 is inserted into the paste storage chamber 49 (49'). In this way, even if the plunger 5 is pulled back by mistake, the elastic body holder 15 (15') is left in the paste storage chamber 49 (49'), and air is not taken into the paste storage chamber 49 (49') from the discharge port 51, (51'). Furthermore, since no air has been taken into the paste storage chamber 49 (49'), by inserting the rod-shaped portion 69 (69') again into the paste storage chamber 49 (49') and engaging it with the elastic holder 15 (15'), an error is unlikely to occur in the indication of the remaining amount of paste shown by the multiple reinforcing ribs 78 (78').

[0149] Furthermore, the paste injector 1 is used for injecting dental material, so that the paste injector 1 can inject the dental material at a desired location.

[0150] Although the embodiments of the present invention have been specifically described above, the present invention is not limited to these embodiments, and it goes without saying that modifications are possible within the scope of the technical concept of the present invention.

[0151] For example, in the above example, five reinforcing ribs, the first reinforcing rib 78A to the fifth reinforcing rib 78E, are provided along the longitudinal direction of the rod-shaped portion 69, but it goes without saying that the number of reinforcing ribs may be increased or decreased. Also, for example, it is possible to provide only the last reinforcing rib.

[0152] In the above example, the syringe has two paste storage chambers (49, 49'), but the paste injector of the present invention may have one paste storage chamber or three or more paste storage chambers. When there is one paste storage chamber, it is of course sufficient to use one type of paste stored in the paste storage chamber.

[0153] In addition, the following will be disclosed in relation to the above-described embodiment. (1) A syringe extending in a longitudinal direction, having a paste storage chamber extending along the longitudinal direction therein and filled with paste, with an outlet formed at one end thereof for opening one end of the paste storage chamber, and a filling port formed at the other end thereof for opening the other end of the paste storage chamber; A plunger having a pressing part that is pressed by a user with a finger and a rod-shaped part that rises from the pressing part and is inserted into the paste storage chamber, the plunger being inserted into the paste storage chamber from the filling port and moving along the longitudinal direction to push out the paste from the discharge port, The rod-shaped portion is provided with a plurality of reinforcing ribs at predetermined intervals along the longitudinal direction to reinforce the rod-shaped portion, At least some of the reinforcing ribs are formed at positions that overlap the filling port when the remaining amount of the paste in the paste storage chamber reaches a predetermined amount. A paste injector comprising: (2) The paste has a predetermined amount for one use, The reinforcing rib provided at a position closest to the pressing portion is formed at a position overlapping the filling port when the remaining amount of the paste in the paste storage chamber is the amount of paste to be used once. A paste injector as described in (1). (3) The cross-sectional shape of the plurality of reinforcing ribs perpendicular to the longitudinal direction is smaller than the cross-sectional shape of the paste storage chamber perpendicular to the longitudinal direction and is similar to the cross-sectional shape of the paste storage chamber. A paste injector according to (1) or (2). (4) A cross-sectional shape of the rod-shaped portion perpendicular to the longitudinal direction is formed into a cross shape including a thickness direction wall portion extending in a thickness direction perpendicular to the longitudinal direction and a width direction wall portion extending in a width direction perpendicular to the longitudinal direction and the thickness direction, The plurality of reinforcing ribs are formed in the gap between the thickness direction wall portion and the width direction wall portion. A paste injector according to any one of (1) to (3). (5) The plunger has an elastic holder loosely engaged with the tip end of the rod-shaped portion, The elastic holder is separated from the rod-shaped portion when the plunger is pulled back toward the filling port after the plunger is inserted into the paste storage chamber. A paste injector according to any one of (1) to (4). (6) A paste injector as described in any one of (1) to (5), characterized in that it is used for injecting a paste which is a dental material. [Explanation of symbols]

[0154] 1 Paste Injector 3 Syringes 5 Plunger 7. Static Mixer 9 Guide Chip 11 Cap 13 Plunger body 15 Elastic holder 17 O-ring (elastic body) 19 Mixing tip body 21 Mixer housing 23 Mixer housing 25 Cap inner member 27 Cap exterior body 29,29´ Paste passage 29A,29A´ Inflow hole 29B,29B´ Outflow hole 29C,29C´ distal surface 29D,29D´ Proximal surface 31 Middle Passage 33 Mixing Passage 35 Backflow prevention wall 37 Element housing part 39 Elements 41 Syringe body 41a Circular wall 41b Recess 43,43´ Protrusion 45 Engagement part 45A, 45B, 45C protrusion piece 47 Finger rest 49,49´ Paste storage room 51,51´ Outlet 53,53´ Filling port 55 Anti-slip projection 57,57´ Width direction outer circumferential surface 59,59´ Outer periphery in thickness direction 61 Connection outer surface 63,63´ Inner flat surface part 65,65´ Inner curved surface part 67 Pressing part 69,69´ Rod-shaped part 71A Thickness direction wall 71B Width wall section 73,73´ Protrusion 75,75´ Hollow section 77,77´ Protrusion 78,78´ Reinforcing ribs 78A, 78A´ First reinforcing rib 78B, 78B´ Second reinforcing rib 78C, 78C´ 3rd reinforcing rib 78D, 78D´ 4th reinforcing rib 78E,78E´ 5th reinforcing rib 79,79´ Holder engagement part 81 Torso 83 Top 85 Neck 87,1087 base 87A 1st end surface 87B 2nd end face 87C Flange 89,89´ Insertion 91,91 Rotating engagement piece 93 Base housing part 93A End wall 93B Peripheral wall part 93C Recess 95 Top wall 97 First peripheral wall part 98 Step 99 Second peripheral wall part 99A Nagabe 99B End Face 99a The first part 99b protrusion 101 Top through tube 103 Circumferential groove 105A,105A´ 1st tie groove 105B,105B´ Second tie groove 107 quilted part 107Aa,107Ba,107Ca 1st groove 107Ab, 107Bb, 107Cb Second groove 109A,109B,109C Headquarters 111 base 113,113´ Insertion 115,115´ Huiyu series film 117 Bottomed recess 119 Top wall part 120 step difference part 121 1st wall 123 2nd wall 123A Nagabe 123B End Face 123a The first part 123b protrusion 125 Circumferential groove 127A,127A´ 1st tie groove 127B,127B´ Second ligature groove 129 Tie-off 129Aa,129Ba,129Ca 1st groove 129Ab, 129Bb, 129Cb Second groove 131A,131B,131C M mounting parts IM inner material OM outer body CA Center Axis X long hand direction Y width direction Z thickness direction

Claims

1. a syringe extending in a longitudinal direction, having a paste storage chamber extending along the longitudinal direction therein and filled with paste, with an outlet formed at one end thereof for opening one end of the paste storage chamber, and a filling port formed at the other end thereof for opening the other end of the paste storage chamber; A plunger having a pressing part that is pressed by a user with a finger and a rod-shaped part that rises from the pressing part and is inserted into the paste storage chamber, the plunger being inserted into the paste storage chamber from the filling port and moving along the longitudinal direction to push out the paste from the discharge port, The rod-shaped portion is provided with a plurality of reinforcing ribs at predetermined intervals along the longitudinal direction to reinforce the rod-shaped portion, At least some of the reinforcing ribs are formed at positions that overlap the filling port when the remaining amount of the paste in the paste storage chamber reaches a predetermined amount. A paste injector comprising:

2. The paste has a predetermined amount for one use, The reinforcing rib provided at a position closest to the pressing portion is formed at a position overlapping the filling port when the remaining amount of the paste in the paste storage chamber is the amount of paste to be used once.

2. The paste injector of claim 1.

3. The cross-sectional shape of the plurality of reinforcing ribs perpendicular to the longitudinal direction is smaller than the cross-sectional shape of the paste storage chamber perpendicular to the longitudinal direction and is similar to the cross-sectional shape of the paste storage chamber.

3. A paste injector according to claim 1 or 2.

4. A cross-sectional shape of the rod-shaped portion perpendicular to the longitudinal direction is formed into a cross shape including a thickness direction wall portion extending in a thickness direction perpendicular to the longitudinal direction and a width direction wall portion extending in a width direction perpendicular to the longitudinal direction and the thickness direction, The plurality of reinforcing ribs are formed in the gap between the thickness direction wall portion and the width direction wall portion.

3. A paste injector according to claim 1 or 2.

5. The plunger has an elastic holder loosely engaged with a tip end of the rod-shaped portion, The elastic holder is separated from the rod-shaped portion when the plunger is pulled back toward the filling port after the plunger is inserted into the paste storage chamber.

3. A paste injector according to claim 1 or 2.

6. 3. The paste injector according to claim 1, which is used for injecting a paste which is a dental material.

Images