Guide tip and static mixer

Abstract

Provided is a guide tip or the like that can appropriately fill, with paste, even a site in the oral cavity where it is difficult to discharge the paste at an angle, and can be attached to an existing static mixer.　A guide tip (9) is attached to a static mixer (7) provided with: a plurality of paste passages (29), (29') which have inflow holes (29A), (29A') and outflow holes (29B), (29B'), and through which a plurality of types of paste individually stored in a syringe (3) extending in a longitudinal direction X respectively pass; an intermediate passage (31) which guides the plurality of types of paste that have exited from the outflow holes (29B), (29B') to a merging position (JP); and a mixing passage (33) through which the plurality of types of paste merged at the merging position (JP) pass while being mixed. The guide tip (9) is mounted on the outside of the static mixer (7) and is bendable.

Description

Guide Chip and Static Mixer

[0001] The present disclosure relates to a guide chip and a static mixer.

[0002] Dental materials are known that consist of multiple types of pastes and are prepared by mixing them immediately before use. To inject such dental materials into a predetermined position, there is a paste injector that discharges while mixing multiple types of pastes.

[0003] The paste injector includes a syringe that stores multiple types of pastes, a plunger that extrudes the paste, and a static mixer attached to the discharge part of the syringe. The static mixer includes a plurality of paste passages through which multiple types of pastes individually stored in the syringe of the paste injector pass, an intermediate passage that guides the multiple types of pastes to a confluence position, and a mixing passage through which the multiple types of pastes that have confluenced at the confluence position pass while being mixed. The static mixer has a guide chip attached to it. As a mixing chip to which the guide chip is attached, for example, Patent Document 1 is disclosed.

[0004] Japanese Patent Translation of PCT International Publication No. 2012-520094

[0005] Since the guide chip described in Patent Document 1 is inserted and held in the mixing passage, it is necessary to manufacture the mixing passage larger than the outer diameter of the guide chip, or to manufacture a dedicated static mixer for holding the guide chip, resulting in the problem that the guide chip cannot be used with existing static mixers.

[0006] An object of the present invention is to provide a guide chip that can appropriately fill a paste even in a location where it is difficult to discharge the paste angularly in the oral cavity and can be attached to an existing static mixer, and a static mixer including this guide chip.

[0007] The present invention provides a guide tip for a static mixer that has an inlet hole and an outlet hole, and comprises multiple paste passages through which multiple types of pastes, each individually stored in a syringe extending in the longitudinal direction, pass; an intermediate passage that guides the multiple types of pastes exiting the outlet hole to a confluence point; and a mixing passage through which the multiple types of pastes, which have been combined at the confluence point, pass while being mixed. The guide tip is mounted on the outside of the static mixer and is flexible.

[0008] By configuring it in this way, it is possible to properly fill areas in the oral cavity where it is difficult to dispense the paste due to the angle, and to provide a guide tip that can be attached to existing static mixers, as well as a static mixer equipped with this guide tip.

[0009] This is a front view of a paste injector equipped with a static mixer to which a guide tip of the first embodiment is attached. This is an exploded perspective view of the paste injector. This is a key part of a cross-sectional view of a paste injector, in which a static mixer is fixed to a syringe, cut in the width direction at a position passing through the central axis extending in the longitudinal direction. This is a cross-sectional view of the cap, cut in the width direction at a position passing through the central axis extending in the longitudinal direction. This is a front view of the syringe. This is a side view of the syringe. This is a top view of the syringe. This is a bottom view of the syringe. This is a cross-sectional view taken along the line V-V shown in Figure 4C. This is an end view taken along the line VI-VI shown in Figure 4A. This is a perspective view of one end of the syringe. This is a perspective view of one end of the syringe. This is a key part of the cross-sectional view taken along the line VIII-VIII shown in Figure 4C. This is a front view of the plunger body. This is a side view of the plunger body. This is a top view of the plunger body. This is a perspective view of the key part of the plunger body. This is a cross-sectional perspective view taken along the line XA-XA shown in Figure 9A. This is an explanatory diagram showing the relationship between the plunger and the paste storage chamber in the cross-section shown in Figure 10A. This is a cross-sectional perspective view taken along the line XC-XC shown in Figure 9A. This is an explanatory diagram showing the relationship between the plunger and the paste storage chamber in the cross-section shown in Figure 10C. This is a perspective view of the elastic body holder. This is a bottom view of the elastic body holder. This is a cross-sectional view taken by cutting the elastic body holder, with the O-ring attached to the groove, in the width direction perpendicular to the longitudinal direction at the neck portion. These are schematic cross-sectional views of the elastic body holder, with the O-ring attached to the groove, when inserted into the paste storage chamber, cut along the width direction perpendicular to the longitudinal direction at the neck portion, schematic cross-sectional views taken by cutting along the thickness direction perpendicular to the width direction at the neck portion, and schematic cross-sectional views taken by cutting along the width direction perpendicular to the thickness direction at the neck portion. This is a perspective view of the mixing tip body. This is a bottom view of the mixing tip body. This is a cross-sectional view taken along the line XV-XV shown in Figure 14B. This is a perspective view of the mixer housing. This is a bottom view of the mixer housing. This is a cross-sectional view taken along line XVII-XVII shown in Figure 16B. This is a front view of the mixer casing. This is a side view of the mixer casing. This is a top view of the mixer casing. This is a bottom view of the mixer casing. This is a perspective view of the mixer casing. This is a perspective view of the mixer casing. This is a cross-sectional view taken along line XIX-XIX shown in Figure 18C. This is a cross-sectional view taken along line XX-XX shown in Figure 18C.This is a broken perspective view along the line XXB-XXB shown in Figure 18C. This is a broken perspective view along the line XX-XX shown in Figure 18C. This is a cross-sectional view along the line XXI-XXI shown in Figure 18A. This is a perspective view of the mixer biasing member. This is a bottom view of the mixer biasing member. This is a cross-sectional view along the line XIII-XXIII shown in Figure 22B. This is a perspective view of the inner cap member. This is a bottom view of the inner cap member. This is a cross-sectional view along the line XXV-XXV shown in Figure 24B. This is a front view of the cap casing. This is a side view of the cap casing. This is a top view of the cap casing. This is a bottom view of the cap casing. This is a perspective view of the cap casing. This is a perspective view of the cap casing. This is a cross-sectional view along the line XVII-XXVII shown in Figure 26C. This is a cross-sectional view along the line XVIIII-XXVIII shown in Figure 26C. This is a broken perspective view along the line XVIIII-XXVIIIB shown in Figure 26C. This is a broken perspective view along the line XVIIII-XXVIII shown in Figure 26C. This is a cross-sectional view taken along the line XXIV-XXIV shown in Figure 26A. This is a perspective view of the cap biasing member. This is a bottom view of the cap biasing member. This is a cross-sectional view taken along the line XXXI-XXXI shown in Figure 30B. This figure shows the state before the static mixer is placed over the syringe and fixed in place. This is a bottom view of the static mixer after only the mixer casing has been rotated. This is a cross-sectional view of the static mixer before the syringe is inserted into the static mixer. These are side views and cross-sectional views of the guide tip. These are side views and cross-sectional views of the guide tip with the guide portion bent. These are side views and cross-sectional views of the guide tip of the second embodiment. These are side views and cross-sectional views of the guide tip of the second embodiment with the guide portion bent.

[0010] (First Embodiment) Hereinafter, embodiments of the paste injector of the present disclosure will be described with reference to the drawings. In this embodiment, the longitudinal direction X, the width direction Y, and the thickness direction Z are defined for the paste injector 1. The longitudinal direction X, the width direction Y, and the thickness direction Z are orthogonal to each other. The longitudinal direction X is the extrusion direction of the paste.

[0011] <Overall Configuration> As shown in Figure 1, the paste injector 1 comprises a syringe 3, a plunger 5, a static mixer 7, and a guide tip 9. The paste injector 1 uses the plunger 5 to push out two types of paste, each individually filled in the syringe 3, along the longitudinal direction X. The paste injector 1 mixes the pastes pushed out from the syringe 3 with the static mixer 7 just before use to prepare them as dental material. The paste injector 1 allows the paste, now a dental material, to be injected into the desired location (affected area) via the guide tip 9.

[0012] The guide tip 9 is a nozzle component that is attached to the static mixer 7 as needed. Once attached to the static mixer 7, the guide tip 9 cannot be easily removed. Furthermore, the paste injector 1 can be used even if the guide tip 9 is not attached to the static mixer 7.

[0013] During storage and transport, the paste injector 1 has a cap 11, as shown in Figure 2, fixed to one end 41A (tip) of the syringe 3 instead of the static mixer 7. In this specification, the static mixer 7 and the cap 11, which are detachably attached to one end 41A of the syringe 3, are collectively referred to as the mounting member M. The syringe 3, plunger 5, and mounting member M (static mixer 7 or cap 11) extend in the longitudinal direction X and are assembled with their central axes CA, which pass through the centers of each member, aligned.

[0014] The paste injector 1 is distributed with a plunger 5 inserted into a syringe 3 filled with paste. The plunger 5 consists of a plunger body 13, an elastic holder 15, and an O-ring (elastic body) 17. The elastic holder 15 loosely engages with one end of the plunger body 13. The O-ring 17 is an annular elastic body attached to the elastic holder 15. Here, "loosely engage" means that the elastic holder 15 engages with such a force that it can be dislodged from the plunger body 13 by the frictional force between the syringe 3 and the O-ring 17 when the plunger 5 is withdrawn from the syringe 3.

[0015] The plunger 5 may be an integrated unit in which the plunger body 13 and the elastic body holder 15 are not separate. In this case, the O-ring 17 is directly attached to the plunger body 13.

[0016] The static mixer 7 consists of a mixing tip body 19, a mixer housing 21, a mixer outer casing 23, and a mixer biasing member 24. The static mixer 7 in this embodiment is a disposable unit that is discarded after a single use.

[0017] The cap 11 is composed of an inner cap member 25, an outer cap body 27, and a cap biasing member 28.

[0018] [Paste Flow Channels] As shown in Figure 3A, paste flow channels are formed inside the static mixer 7. These paste flow channels are formed by the mixing tip body 19 and the mixer housing 21. The paste flow channels consist of a first paste passage 29, a second paste passage 29', an intermediate passage 31, and a mixing passage 33.

[0019] The first paste passage 29 and the second paste passage 29' each extend in the longitudinal direction X. The first paste passage 29 and the second paste passage 29' are arranged side by side on the same circumference with respect to the central axis CA. The first paste passage 29 and the second paste passage 29' are formed symmetrically along the width direction Y.

[0020] The mixing passage 33 is located downstream in the paste flow direction from the first paste passage 29 and the second paste passage 29'. The mixing passage 33 extends longitudinally in the X direction along the central axis CA.

[0021] The intermediate passage 31 is a passage that connects the first paste passage 29 and the second paste passage 29' with the mixing passage 33.

[0022] The first paste passage 29 is a passage through which the paste discharged from the first paste storage chamber 49 of the syringe 3 flows. The first paste passage 29 is formed in the mixing tip body portion 19. The first paste passage 29 also has an inlet hole 29A through which the paste flows in and an outlet hole 29B through which the paste flows out. The opening area of ​​the inlet hole 29A is larger than the opening area of ​​the outlet hole 29B. Furthermore, the opening center point of the outlet hole 29B is set to be closer to the central axis CA than the opening center point of the inlet hole 29A when viewed along the longitudinal direction X.

[0023] The inner surface of the first paste passage 29 has a distal surface 29C and a proximal surface 29D. Here, the distal surface 29C is the surface that is further from the central axis CA than the paste flow space when viewed in a cross section perpendicular to the thickness direction Z (see Figure 3A). The proximal surface 29D is the surface that is closer to the central axis CA than the paste flow space when viewed in a cross section perpendicular to the thickness direction Z (see Figure 3A).

[0024] The distal surface 29C has a tapered portion 29E formed in the region from the inlet hole 29A to an intermediate position in the first paste passage 29. The tapered portion 29E is an inclined surface that gradually approaches the central axis CA as it moves from the inlet hole 29A towards the interior of the first paste passage 29. In other words, the distal surface 29C is formed in a tapered shape from the inlet hole 29A to an intermediate position in the first paste passage 29, gradually approaching the central axis CA as it moves towards the outlet hole 29B. Furthermore, the distal surface 29C extends parallel to the central axis CA in the region from an intermediate position in the first paste passage 29 to the outlet hole 29B.

[0025] As shown in Figure 15, the inclination angle θ of the tapered portion 29E is set to 45° here. The "inclination angle θ of the tapered portion 29E" is the angle made between the distal surface 29C and the straight line C1 (see Figure 15) that extends in the longitudinal direction X through the center point of the inflow hole 29A. In other words, the "inclination angle θ of the tapered portion 29E" is set as the inclination angle of the distal surface 29C with respect to the straight line C1.

[0026] The proximal surface 29D extends along the central axis CA from the inlet hole 29A to the outlet hole 29B. In other words, the proximal surface 29D extends parallel to the central axis CA along its entire length in the longitudinal direction X.

[0027] Furthermore, in the first paste passage 29, the cross-sectional area in the direction perpendicular to the longitudinal direction X gradually decreases at a constant rate in the region from the inlet hole 29A to the middle of the longitudinal direction X. The region from the inlet hole 29A to the middle of the longitudinal direction X is the region where the tapered portion 29E is formed. Also, in the region from the middle of the longitudinal direction X to the outlet hole 29B, the cross-sectional area in the direction perpendicular to the longitudinal direction X is the same size as the opening area of ​​the outlet hole 29B. The region from the middle of the longitudinal direction X to the outlet hole 29B is the region where the tapered portion 29E is not formed.

[0028] The paste injector 1 has a tapered portion 29E formed on its distal surface 29C, which helps to suppress the formation of air bubbles in the first paste passage 29.

[0029] The second paste passage 29' is a passage through which the paste discharged from the second paste storage chamber 49' of the syringe 3 flows. The second paste passage 29' is formed in the same configuration as the first paste passage 29. For this reason, in this specification and the drawings, the components of the second paste passage 29' are indicated by adding an apostrophe to the reference numerals of the parts of the first paste passage 29, and their descriptions are omitted.

[0030] The first paste passage 29 and the second paste passage 29' are formed to the same size and exhibit a symmetrical shape along 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. Also, the outlet hole 29B and the outlet hole 29B' are set to have the same opening area. Furthermore, the distance from the central axis CA to the center of the inlet hole 29A and the distance from the central axis CA to the inlet hole 29A' are the same when viewed along the longitudinal direction X. Also, the distance from the central axis CA to the center of the outlet hole 29B and the distance from the central axis CA to the outlet hole 29B' are the same when viewed along the longitudinal direction X. Furthermore, the inclination angle θ of the tapered portion 29E on the distal surface 29C and the inclination angle θ' of the tapered portion 29E' on the distal surface 29C' are the same angle.

[0031] The intermediate passage 31 is a passage that guides the paste that has flowed out from the outlet holes 29B and 29B' to the confluence position JP. In this embodiment, a backflow prevention wall 35 is provided between the outlet holes 29B and 29B'. The backflow prevention wall 35 divides the intermediate passage 31 into the outlet hole 29B side and the outlet hole 29B' side. The backflow prevention wall 35 rises from the end face of the mixing tip body portion 19 in which the outlet holes 29B and 29B' are formed, and extends along the central axis CA to the confluence position JP. As a result, the backflow prevention wall 35 prevents paste that has come out of one outlet hole 29B from flowing into the other outlet hole 29B', and prevents paste that has come out of the other outlet hole 29B' from flowing into the one outlet hole 29B. The backflow prevention wall 35 has curved surfaces 35A and 35A' formed at its base to direct the paste towards the confluence position JP.

[0032] The mixing passage 33 is a passage through which the pastes that merged at the confluence point JP are mixed. The mixing passage 33 consists of a cylindrical element housing portion 37 extending from the mixer housing 21 and a group of elements 39 extending from the end of the backflow prevention wall 35 and inserted into the element housing portion 37.

[0033] [Securing the Mounting Member] The mounting member M, either the static mixer 7 or the cap 11, is detachably attached to one end 41A of the syringe 3. The configuration of the static mixer 7 and the cap 11, and their fixing structure, will be described below with reference to Figures 3A and 3B.

[0034] The mounting member M consists of an inner member IM, an outer body OM, and a biasing member EM.

[0035] Here, if the mounting member M is a static mixer 7, the inner member IM is composed of the mixing tip body 19 and the mixer housing 21. The outer body OM is composed of the mixer outer body 23. Furthermore, the biasing member EM is composed of the mixer biasing member 24.

[0036] On the other hand, when the mounting member M is a cap 11, the inner member IM is formed by the cap inner member 25. The outer body OM is formed by the cap outer body 27. Furthermore, the biasing member EM is formed by the cap biasing member 28.

[0037] In the static mixer 7, as shown in Figure 3A, the mixing tip body portion 19 and the mixer housing 21, which are the inner members IM, are arranged inside the mixer outer casing 23, which are the outer casing OM. A biasing member EM, which is the mixer biasing member 24, is sandwiched between the mixer outer casing 23 (outer casing OM) and the mixer housing 21 (inner member IM). Furthermore, the mixing tip body portion 19 and the mixer housing 21 are configured to be able to rotate relative to the mixer outer casing 23 around the central axis CA within a predetermined angular range.

[0038] Similarly, in cap 11, as shown in Figure 3B, the inner cap member 25, which is the inner member IM, is positioned inside the outer cap body 27, which is the outer cap body OM. A biasing member EM, which is the biasing member 28, is sandwiched between the outer cap body 27 (outer cap body OM) and the inner cap member 25 (inner member IM). The inner cap member 25 is configured to rotate relative to the outer cap body 27 within a predetermined angular range around its central axis CA.

[0039] Then, when one end 41A of the syringe 3 is fixed to the mounting member M along the longitudinal direction X, the syringe 3 is inserted into the outer casing OM via the inner member IM. At this time, a part of the inner member IM enters the syringe 3, and the inner member IM becomes unable to rotate relative to the syringe 3. On the other hand, the outer casing OM is rotatable relative to the syringe 3 with the syringe 3 inserted.

[0040] The mounting member M is fixed to the syringe 3 via an engagement structure by the outer casing OM rotating relative to the syringe 3 around the central axis CA. When the mounting member M is attached to the syringe 3, the biasing member EM is compressed between the outer casing OM and the inner member IM, biasing the inner member IM relative to the syringe 3.

[0041] When the mounting member M is a static mixer 7, the engagement structure consists of three or more engagement sets (three sets in this embodiment) consisting of an engaged portion 46 formed on the syringe 3 and an engaging portion 107 formed on the mixer casing 23, which is the outer casing OM. When the mounting member M is a cap 11, the engagement structure consists of three or more engagement sets (three sets in this embodiment) consisting of an engaged portion 46 formed on the syringe 3 and an engaging portion 129 formed on the cap casing 27, which is the outer casing OM. The detailed configurations of the engaged portion 46, the engaging portion 107, and the engaging portion 129 will be described later.

[0042] <Details of each component> [Syringe] Syringe 3 is a cylindrical body extending in the longitudinal direction X. As shown in Figure 4A, etc., one end 41A that constitutes the tip of syringe 3 has a shoulder portion 42, an insertion side portion 43, a circular wall portion 44, a first cylindrical portion 45 and a second cylindrical portion 45', and an engaging portion 46. A finger rest portion 47 is formed at the other end 41B of syringe 3. Furthermore, as shown in Figure 5, a first paste storage chamber 49 (paste storage chamber) and a second paste storage chamber 49' (paste storage chamber) are formed inside syringe 3.

[0043] The shoulder portion 42 is formed on the outer peripheral surface of the syringe 3 and is a stepped portion that reduces the outer diameter of the syringe. As shown in FIGS. 7A and 7B, the shoulder portion 42 has an end face 42a and an inclined face 42b. The end face 42a is a face orthogonal to the longitudinal direction X. The inclined face 42b is continuous from the end face 42a and is a face that gradually inclines toward the central axis CA side as it goes toward the tip of the syringe (the one end portion 41A side). The shoulder portion 42 extends in an arc shape along the circumferential direction of the syringe 3. Note that the shoulder portion 42 does not surround the entire circumference of the syringe 3 and is divided into two in a state arranged in the width direction Y.

[0044] The insertion side surface portion 43 is the outer peripheral surface of the syringe 3 continuous from the two shoulder portions 42. The insertion side surface portion 43 is a face parallel to the longitudinal direction X. Also, the insertion side surface portion 43 extends in an arc shape along the circumferential direction of the syringe 3. Note that the insertion side surface portion 43 does not surround the entire circumference of the syringe 3 and is divided into two in a state arranged in the width direction Y, similar to the shoulder portion 42.

[0045] And, a regulating convex portion 43a is formed on one of the insertion side surface portions 43. The regulating convex portion 43a is a regulated portion that engages with a regulating portion 108 and a regulating portion 130, which will be described later, when the mounting member M is fixed to one end portion 41A of the syringe 3. The regulating convex portion 43a is a protruding projection-shaped portion that protrudes outward from a part of the insertion side surface portion 43, which is the outer peripheral surface of the syringe 3. The regulating convex portion 43a is formed between a first protruding piece 46A and a second protruding piece 46B, which will be described later, when viewed along the longitudinal direction X. Also, as shown in FIG. 7B, the regulating convex portion 43a is continuous from the inclined face 42b of the shoulder portion 42 and extends in the longitudinal direction X. The protruding height of the regulating convex portion 43a from the insertion side surface portion 43 is set to a height that fits inside the shoulder portion 42.

[0046] The circular wall portion 44 is a disk portion formed continuously from the tip of the insertion side surface portion 43 (the end on the one end portion 41A side). The shape of the circular wall portion 44 when cut by a face orthogonal to the longitudinal direction X is circular. On the surface of the circular wall portion 44 (the end face on the one end portion 41A side), a first cylindrical portion 45 and a second cylindrical portion 45', and a concave portion 44a, are formed.

[0047] The first cylindrical portion 45 and the second cylindrical portion 45' project from the surface of the circular wall portion 44 in the longitudinal direction X. Here, the first cylindrical portion 45 and the second cylindrical portion 45' have a cylindrical shape with both ends open. And the first cylindrical portion 45 and the second cylindrical portion 45' respectively form discharge ports 51, 51'.

[0048] The first cylindrical portion 45 communicates with the first paste storage chamber 49. The inner peripheral surface of the first cylindrical portion 45 constitutes a part of the first paste storage chamber 49. The second cylindrical portion 45' communicates with the second paste storage chamber 49'. The inner peripheral surface of the second cylindrical portion 45' constitutes a part of the second paste storage chamber 49'. Note that the first cylindrical portion 45 and the second cylindrical portion 45' are connected via a standing wall 44b standing from the circular wall portion 44, and their inclination is restricted.

[0049] The recess 44a is a depression formed on the surface of the circular wall portion 44. The recess 44a is formed between the peripheral edge of the circular wall portion 44 and the first cylindrical portion 45 and the second cylindrical portion 45'. Appropriate steps are provided in the recess 44a. Due to the formation of the recess 44a on the surface of the circular wall portion 44 of the syringe 3, the occurrence of sink marks during resin molding is prevented. Also, since the occurrence of sink marks is prevented, the syringe 3 can suppress the inclination of the first cylindrical portion 45 and the second cylindrical portion 45'.

[0050] The engaged portion 46 constitutes an engaging structure for fixing the mounting member M to one end portion 41A of the syringe 3. That is, the engaged portion 46 is a portion that engages with the engaging portions (engaging portion 107 and engaging portion 129) of the mounting member M (static mixer 7 and cap 11). As shown in FIG. 4C, the engaged portion 46 is composed of a first protruding piece 46A (protruding piece), a second protruding piece 46B (protruding piece), and a third protruding piece 46C (protruding piece).

[0051] The first projection 46A, the second projection 46B, and the third projection 46C each protrude from the circumferential surface of the circular wall portion 44 in a direction perpendicular to the longitudinal direction X, and are aligned along the rotation direction of the outer casing OM. Furthermore, when viewed along the longitudinal direction X, the first projection 46A, the second projection 46B, and the third projection 46C are arranged asymmetrically with respect to the central axis CA. Here, the "central axis CA" is the rotation center of the outer casing OM. In general, "point symmetry" refers to the fact that when a figure is rotated 180° around a point of symmetry, it overlaps with the original figure. However, "asymmetrical" here means that when the syringe 3 rotates around the central axis CA, the first projection 46A, the second projection 46B, and the third projection 46C do not overlap with each other except when rotated 360°.

[0052] Furthermore, the first projection 46A, the second projection 46B, and the third projection 46C are arranged at non-equal intervals along the rotational direction of the outer casing OM. Here, the rotational distance from the first projection 46A to the second projection 46B and the rotational distance from the first projection 46A to the third projection 46C are set to be the same length. On the other hand, the rotational distance from the second projection 46B to the third projection 46C is set to be shorter than the distance from the first projection 46A to the second projection 46B and the distance from the first projection 46A to the third projection 46C.

[0053] Furthermore, the first projection 46A, the second projection 46B, and the third projection 46C each exhibit different shapes when viewed along the longitudinal direction X. In this embodiment, the length of the first projection 46A in the rotational direction is set to be longer than the lengths of the second projection 46B and the third projection 46C in the rotational direction. On the other hand, the lengths of the second projection 46B and the third projection 46C in the rotational direction are set to be the same.

[0054] Furthermore, the second projection 46B and the third projection 46C are set to protrude in different directions from the outer circumferential surface of the circular wall portion 44. In addition, the second projection 46B and the third projection 46C are set to have a shape that is symmetrical with respect to the axis of symmetry AS, which passes through the central axis CA and the circumferential center position of the first projection 46A.

[0055] The finger rest portion 47 is a flange-like portion extending in the width direction Y and thickness direction Z from the other end 41B of the syringe 3. As shown in Figures 4C and 4D, the outer circumference of the finger rest portion 47 is formed to be approximately hexagonal when viewed along the longitudinal direction X. The finger rest portion 47 may have a textured surface 47a on at least one end 41A side. By applying a textured surface to a part of the surface 47a of the finger rest portion 47, the user's fingers can be prevented from slipping. In addition, the finger rest portion 47 can improve the appearance quality by making gate marks less noticeable.

[0056] Furthermore, the syringe 3 has, as shown in Figure 6, a pair of widthwise outer surfaces 57A, 57B, a pair of thicknesswise outer surfaces 59A, 59B, and four connecting outer surfaces 61 on its outer surface from the shoulder portion 42 to the finger rest portion 47.

[0057] The pair of outer circumferential surfaces 57A and 57B in the width direction are surfaces of the outer circumferential surface of the syringe 3 that are located opposite each other along the thickness direction Z. Each outer circumferential surface 57A and 57B has a flat portion 57C that has a constant length in the width direction Y and extends in the longitudinal direction X. In addition, each outer circumferential surface 57A and 57B has a groove-shaped recessed portion 57D that extends in the longitudinal direction X and is recessed more deeply than the flat portion 57C. The recessed portion 57D is formed between the first paste storage chamber 49 and the second paste storage chamber 49'. The flat portion 57C is divided into two parts along the width direction Y by the recessed portion 57D. Furthermore, the recessed portion 57D has a wedge-shaped or V-shaped cross-section in which the length in the width direction Y gradually decreases as it becomes deeper.

[0058] The pair of outer circumferential surfaces 59A and 59B in the thickness direction are surfaces of the outer circumferential surface of the syringe 3 that are located opposite each other along the width direction Y. Each outer circumferential surface 59A and 59B in the thickness direction has a constant length in the thickness direction Z and extends in the longitudinal direction X. When viewed in a cross section perpendicular to the longitudinal direction X (see Figure 6), each outer circumferential surface 59A and 59B in the thickness direction is curved outward in the width direction Y with a predetermined radius of curvature (for example, radii of curvature R1 to R5, R5 in this embodiment).

[0059] The four connecting outer surfaces 61 are located on the outer surface of the syringe 3, between the widthwise outer surface 57A and the thicknesswise outer surface 59A, between the widthwise outer surface 57B and the thicknesswise outer surface 59A, between the widthwise outer surface 57A and the thicknesswise outer surface 59B, and between the widthwise outer surface 57B and the thicknesswise outer surface 59B. When viewed in a cross section perpendicular to the longitudinal direction X, each connecting outer surface 61 is curved outward with a predetermined radius of curvature (for example, radius of curvature R1 to R5, R2.5 in this embodiment). As a result, each connecting outer surface 61 smoothly connects the widthwise outer surface 57A and the thicknesswise outer surface 59A, the widthwise outer surface 57B and the thicknesswise outer surface 59A, the widthwise outer surface 57A and the thicknesswise outer surface 59B, and the widthwise outer surface 57B and the thicknesswise outer surface 59B. Furthermore, the connecting outer surface 61 and the pair of outer surfaces 59A and 59B in the thickness direction are formed by combining multiple curved surfaces set with different radii of curvature. Alternatively, the connecting outer surface 61 and the pair of outer surfaces 59A and 59B in the thickness direction may be formed by curved surfaces set with the same radius of curvature.

[0060] The first paste storage chamber 49 and the second paste storage chamber 49' formed inside the syringe 3 are spaces for filling paste independently. The first paste storage chamber 49 and the second paste storage chamber 49' each extend in the longitudinal direction X (see Figure 5). The first paste storage chamber 49 and the second paste storage chamber 49' are arranged side by side along the width direction Y, parallel to the longitudinal direction X. In this embodiment, the first paste storage chamber 49 and the second paste storage chamber 49' have the same shape. That is, the area ratio of the cross-sectional area in the direction perpendicular to the longitudinal direction X of the first paste storage chamber 49 and the second paste storage chamber 49' is set to a ratio of 1:1, and the length in the longitudinal direction X is set to the same length. The paste capacity of the first paste storage chamber 49 and the paste capacity of the second paste storage chamber 49' are the same.

[0061] The first paste storage chamber 49 has a discharge port 51 at one end (first cylindrical portion 45) and a filling port 53 at the other end. The discharge port 51 is an opening that opens one end of the first paste storage chamber 49. The paste filled in the first paste storage chamber 49 is pushed out by the plunger 5 and discharged from the discharge port 51. The filling port 53 is an opening that opens the other end of the first paste storage chamber 49. The plunger 5 is inserted through the filling port 53. The end portion 49A of the first paste storage chamber 49 on the discharge port 51 side has a tapered shape into which the tip portion of the plunger 5 (the top portion 83 of the elastic body holder 15) fits.

[0062] As shown in Figure 6, the first paste storage chamber 49 has a cross-sectional shape that, when cut in a direction perpendicular to the longitudinal direction X, is set to an elliptical shape where the longitudinal axis LA is aligned with the thickness direction Z and the minor axis SA is aligned with the width direction Y. The term "elliptical shape" is a concept that includes not only the ellipse as defined in geometry, but also shapes that approximate an ellipse, such as an oblong (oval, a shape formed by connecting two semicircles with two straight lines), an elliptic arch (a shape formed by cutting out a part of an ellipse along a straight line), a flattened ellipse (a shape formed by flattening an ellipse in the direction of the major or minor axis), and an oval shape.

[0063] The inner circumferential surface of the first paste storage chamber 49 in this embodiment is composed of a pair of flat inner surface portions 63A and 63B having a constant length in the thickness direction Z and extending along the longitudinal direction X, and a pair of inner curved surface portions 65A and 65B that are curved with a predetermined curvature.

[0064] The pair of inner flat surfaces 63A and 63B face each other along the width direction Y, with the internal space of the first paste storage chamber 49 in between. The pair of inner curved surfaces 65A and 65B face each other along the thickness direction Z, with the internal space of the first paste storage chamber 49 in between. The pair of inner curved surfaces 65A and 65B smoothly connect to the pair of inner flat surfaces 63A and 63B. As a result, in this embodiment, the cross-sectional shape of the inner circumferential surface of the first paste storage chamber 49 is a flattened ellipse.

[0065] Furthermore, in the cross-sectional shape of the inner surface of the first paste storage chamber 49, which has an elliptical shape, when the length dimension W1 of the short axis direction SA is set to 1, it is preferable that the length dimension T1 of the long axis direction LA is set in the range of 1.1 to 2.0. In this embodiment, the length dimension T1 of the long axis direction LA is set to 1.3, with the length dimension W1 of the short axis direction SA being set to 1. That is, the length dimension T1 of the long axis direction LA is set to 1.3 times the length dimension W1 of the short axis direction SA. Specifically, it is preferable that the length dimension T1 of the long axis direction LA is set to 5 mm to 20 mm. Specifically, it is preferable that the length dimension W1 of the short axis direction SA is set to 4.5 mm to 10 mm.

[0066] Furthermore, the first paste storage chamber 49 is provided with a plurality of retaining protrusions 55 on the inner circumferential surface of the end 49B on the filling port 53 side (see Figure 5). The plurality of retaining protrusions 55 are projections that protrude from the inner circumferential surface of the first paste storage chamber 49. The plurality of retaining protrusions 55 are arranged in a circumferential direction and are formed in a region of the inner circumferential surface of the first paste storage chamber 49 where the leading edge 71f of the plate material 71 of the plunger 5 (described later) does not face it. In addition, the protrusion height of each retaining protrusion 55 from the inner circumferential surface of the first paste storage chamber 49 is set to be approximately the same as the size of the gap S3 between the inner circumferential surface of the first paste storage chamber 49 and the reinforcing rib 78 of the plunger 5 (described later).

[0067] Therefore, when the plunger 5 is inserted into the first paste storage chamber 49, the retaining projection 55 comes into contact with the outer surface of the reinforcing rib 78. This prevents the plunger 5 from falling out of the syringe 3.

[0068] The second paste storage chamber 49' is formed in the same configuration as the first paste storage chamber 49. For this reason, in this specification and the drawings, the configurations of the second paste storage chamber 49' are indicated by adding an apostrophe to the reference numerals of the parts of the first paste storage chamber 49, and their descriptions are omitted.

[0069] [Plunger body] As shown in Figure 9A, the plunger body 13 comprises a first rod portion 69 (rod portion) and a second rod portion 69' (rod portion), and an operating portion 67.

[0070] The first rod portion 69 and the second rod portion 69' each extend in the longitudinal direction X. Here, the length of the first rod portion 69 and the second rod portion 69' in the longitudinal direction X must be at least longer than the length of the first paste storage chamber 49 and the second paste storage chamber 49' in the longitudinal direction X. The first rod portion 69 and the second rod portion 69' are arranged side by side along the width direction Y, parallel to the longitudinal direction X. The first rod portion 69 and the second rod portion 69' are then inserted simultaneously into the first paste storage chamber 49 and the second paste storage chamber 49', respectively.

[0071] In this embodiment, the first rod portion 69 and the second rod portion 69' have the same shape. That is, the cross-sectional shape of the first rod portion 69 and the second rod portion 69' in the direction perpendicular to the longitudinal direction X is set to be the same. Also, the length of the first rod portion 69 in the longitudinal direction X and the length of the second rod portion 69' in the longitudinal direction X are set to be the same. Therefore, both the first rod portion 69 and the second rod portion 69' can be inserted into the first paste storage chamber 49 and the second paste storage chamber 49'. In other words, when the first rod portion 69 is inserted into the first paste storage chamber 49, the second rod portion 69' is inserted into the second paste storage chamber 49'. Also, when the first rod portion 69 is inserted into the second paste storage chamber 49', the second rod portion 69' is inserted into the first paste storage chamber 49.

[0072] A holder engagement portion 79 is formed at one end of the first rod portion 69. A holder engagement portion 79' is formed at one end of the second rod portion 69'. Furthermore, the other end of the first rod portion 69 and the other end of the second rod portion 69' are both connected to the operating portion 67.

[0073] The first rod portion 69 has a plurality (four) of plate materials 71, a plurality (four) of reinforcing portions 72, a plurality (nine) of reinforcing ribs 78, and a holder engagement portion 79. In this embodiment, the plurality of plate materials 71, the plurality of reinforcing portions 72, the plurality of reinforcing ribs 78, and the holder engagement portion 79 are formed by injection molding of the same resin material. Therefore, there are no seams between each part.

[0074] Each of the multiple plate materials 71 is strip-shaped and extends in the longitudinal direction X. The base edges 71e of each plate material 71 are connected to each other to form a rod axis R that extends in the longitudinal direction X. The "base edge 71e" is one of the edges of the plate material 71 in the short direction. The multiple plate materials 71 are arranged at predetermined angular intervals θ1 (all 90° in this case) along the circumferential direction around the rod axis R, as shown in Figure 10B.

[0075] In this embodiment, the multiple plate members 71 are composed of a first thickness-direction wall portion 71A, a second thickness-direction wall portion 71B, a first width-direction wall portion 71C, and a second width-direction wall portion 71D, as shown in Figures 10A and 10B. The first thickness-direction wall portion 71A and the second thickness-direction wall portion 71B are plate members 71 that extend in opposite directions along the thickness direction Z with respect to the rod axis R when viewed in a cross section perpendicular to the longitudinal direction X. The first width-direction wall portion 71C and the second width-direction wall portion 71D are plate members 71 that extend in opposite directions along the width direction Y with respect to the rod axis R when viewed in a cross section perpendicular to the longitudinal direction X.

[0076] Furthermore, when the first rod portion 69 is inserted into the first paste storage chamber 49 (or the second paste storage chamber 49' (hereinafter the same)), the rod axis R is positioned at the center of the first paste storage chamber 49, as shown in Figures 10B and 10D. The tip edge 71f of the first thickness-direction wall portion 71A faces the inner curved surface portion 65A of the first paste storage chamber 49. The tip edge 71f of the second thickness-direction wall portion 71B faces the inner curved surface portion 65B of the first paste storage chamber 49. The tip edge 71f of the first width-direction wall portion 71C faces the inner flat surface portion 63A of the first paste storage chamber 49. The tip edge 71f of the second width-direction wall portion 71D faces the inner flat surface portion 63B of the first paste storage chamber 49. Note that "tip edge 71f" is the other end edge in the short-side direction of the plate material 71.

[0077] The length dimension α along the thickness direction Z, from the leading edge 71f of the first thickness-direction wall portion 71A to the leading edge 71f of the second thickness-direction wall portion 71B, is set to be slightly shorter than the maximum length LA along the long axis of the first paste storage chamber 49 and the second paste storage chamber 49'. Also, the length dimension β along the width direction Y, from the leading edge 71f of the first width-direction wall portion 71C to the leading edge 71f of the second width-direction wall portion 71D, is set to be slightly shorter than the maximum length SA along the short axis of the first paste storage chamber 49 and the second paste storage chamber 49'.

[0078] Therefore, as shown in Figures 10B and 10D, when the first rod portion 69 is inserted into the first paste storage chamber 49, a gap S1 is created between the inner circumferential surface of the first paste storage chamber 49 (i.e., the inner flat surface portions 63A, 63B or the inner curved surface portions 65A, 65B) and the tip edge 71f of each plate material 71. The "gap S1" is the distance along the radial direction centered on the rod axis R.

[0079] Furthermore, as shown in Figure 9A, a plurality of protrusions 71g are formed on the leading edge 71f of each plate material 71. Each protrusion 71g is a projection that extends outward from the leading edge 71f. The plurality of protrusions 71g are arranged at predetermined intervals in the longitudinal direction X. The height of each protrusion 71g from the leading edge 71f is set to be approximately the same as the size of the gap S1 between the inner circumferential surface of the first paste storage chamber 49 and the leading edge 71f of the plate material 71.

[0080] Therefore, when the first rod portion 69 is inserted into the first paste storage chamber 49, each protruding portion 71g comes into contact with the inner circumferential surface of the first paste storage chamber 49. This suppresses rattling and bending of the first rod portion 69.

[0081] Each of the multiple reinforcing sections 72 connects adjacent plate members 71 in the circumferential direction around the rod axis R, thereby integrating the multiple plate members 71 into one unit.

[0082] In this embodiment, the multiple reinforcing parts 72 are composed of a first reinforcing part 72A, a second reinforcing part 72B, a third reinforcing part 72C, and a fourth reinforcing part 72D, as shown in Figures 10A and 10B. The first reinforcing part 72A is a reinforcing part 72 that connects the first thickness-direction wall part 71A and the first width-direction wall part 71C. The second reinforcing part 72B is a reinforcing part 72 that connects the second thickness-direction wall part 71B and the first width-direction wall part 71C. The third reinforcing part 72C is a reinforcing part 72 that connects the second thickness-direction wall part 71B and the second width-direction wall part 71D. The fourth reinforcing part 72D is a reinforcing part 72 that connects the first thickness-direction wall part 71A and the second width-direction wall part 71D.

[0083] Furthermore, as shown in Figures 9A and 9B, each reinforcing portion 72 is formed continuously from the holder engaging portion 79 that constitutes the tip of the plunger 5 to the operating portion 67. Also, as shown in Figure 10B and the like, each reinforcing portion 72 is formed integrally with the base edge 71e of the plate material 71. Moreover, when viewed in a cross section perpendicular to the longitudinal direction X, each reinforcing portion 72 is provided in the region from the base edge 71e to the tip edge 71f of each plate material 71. In other words, in a cross section perpendicular to the longitudinal direction X, as shown in Figure 10B, the first rod portion 69 has a shape in which the reinforcing portion 72 is provided in a predetermined range centered on the rod axis R, and the tip edge 71f of each plate material 71 protrudes from the outer circumferential surface of the reinforcing portion 72.

[0084] When the first rod portion 69 is inserted into the first paste storage chamber 49, a gap S2 is created between the inner surface of the first paste storage chamber 49 and the outer surface 72e of the reinforcing portion 72, as shown in Figure 10B. The "gap S2" is the distance along the radial direction centered on the rod axis R. Here, the minimum size of the gap S2 between the inner surface of the first paste storage chamber 49 and the outer surface 72e of the reinforcing portion 72 is set to be larger than the maximum size of the gap S1 between the inner surface of the first paste storage chamber 49 and the tip edge 71f of the plate material 71. That is, the size of the gap S1 between the inner surface of the first paste storage chamber 49 and the tip edge 71f of the plate material 71 is smaller than the size of the gap S2 between the inner surface of the first paste storage chamber 49 and the outer surface 72e of the reinforcing portion 72. By using this structure, the deflection of the plunger 5 is suppressed, interference between the syringe 3 and the plunger 5 is suppressed, and the paste can be properly extruded.

[0085] Furthermore, the cross-sectional area of ​​the first rod portion 69 in the direction perpendicular to the longitudinal direction X is set to be 50% or more of the cross-sectional area of ​​the first paste storage chamber 49 in the direction perpendicular to the longitudinal direction X.

[0086] Multiple reinforcing ribs 78 connect adjacent plate materials 71 in the circumferential direction around the rod axis R, integrating the multiple plate materials 71. As shown in Figure 10D, the cross-sectional shape of each reinforcing rib 78 perpendicular to its longitudinal direction X is smaller than the cross-sectional shape perpendicular to the longitudinal direction X of the first paste storage chamber 49, and is set to an elliptical shape similar to the cross-sectional shape of the first paste storage chamber 49, as it is integrated with each plate material 71 and each reinforcing part 72.

[0087] Therefore, when the first rod portion 69 is inserted into the first paste storage chamber 49, a gap S3 is created between the inner surface of the first paste storage chamber 49 and the outer surface 78a of the reinforcing rib 78 (see Figure 10D). The "gap S3" is the distance along the radial direction centered on the rod axis R.

[0088] Furthermore, the maximum size of the gap S3 between the inner surface of the first paste storage chamber 49 and the outer surface 78a of the reinforcing rib 78 is set to be smaller than the minimum size of the gap S2 between the inner surface of the first paste storage chamber 49 and the outer surface 72e of the reinforcing part 72. Moreover, the minimum size of the gap S3 between the inner surface of the first paste storage chamber 49 and the outer surface 78a of the reinforcing rib 78 is set to be larger than the maximum size of the gap S1 between the inner surface of the first paste storage chamber 49 and the leading edge 71f of the plate material 71. In other words, the size of the gap S3 between the inner surface of the first paste storage chamber 49 and the outer surface 78a of the reinforcing rib 78 is smaller than the size of the gap S2 between the inner surface of the first paste storage chamber 49 and the outer surface 72e of the reinforcing part 72, and larger than the size of the gap S1 between the inner surface of the first paste storage chamber 49 and the leading edge 71f of the plate material 71.

[0089] Furthermore, as shown in Figures 9A and 9B, each reinforcing rib 78 is set to have a length in the longitudinal direction X that is shorter than that of the reinforcing portion 72. At least two reinforcing ribs 78 are provided between the holder engagement portion 79 and the operating portion 67 at predetermined intervals along the longitudinal direction X. In this embodiment, nine reinforcing ribs 78 are provided between the holder engagement portion 79 and the operating portion 67.

[0090] The holder engagement portion 79 is formed at one end of the first rod portion 69. The elastic holder 15 is attached to the holder engagement portion 79, which constitutes the tip of the plunger 5. The holder engagement portion 79 comprises a tip wall portion 79A and an engagement projection 79B.

[0091] The tip wall portion 79A is a disc member that connects the longitudinal end faces of the multiple plate materials 71. The tip wall portion 79A contacts the bottom surface 81A of the elastic body holder 15. As shown in Figures 9C and 9D, the cross-sectional shape of the tip wall portion 79A perpendicular to the longitudinal direction X is smaller than the cross-sectional shape of the first paste storage chamber 49 perpendicular to the longitudinal direction X, and is set to an elliptical shape similar to the cross-sectional shape of the first paste storage chamber 49.

[0092] The engaging projection 79B is a rod-shaped member extending longitudinally X from the tip wall portion 79A. The engaging projection 79B is inserted into the engagement hole 81B formed in the bottom surface 81A of the elastic body holder 15.

[0093] The second rod portion 69' is formed in the same configuration as the first rod portion 69. For this reason, in this specification and the drawings, the components of the second rod portion 69' are indicated by adding "'" to the reference numerals of the parts of the first rod portion 69, and their descriptions are omitted.

[0094] The operating section 67 is a plate-shaped portion formed at the other end of the first rod section 69 and the second rod section 69'. The operating section 67 is pressed by a finger (for example, the thumb) when the user holds the syringe 3 between two fingers (for example, the index finger and middle finger) and places their fingers on the finger rest 47, and pushes the plunger 5 into the syringe 3.

[0095] Furthermore, both the first rod portion 69 and the second rod portion 69' have their other ends connected to the operating portion 67. Therefore, the first rod portion 69 and the second rod portion 69' are connected via a single operating portion 67.

[0096] Furthermore, as shown in Figure 9C, the operating section 67 has a circular outer shape when viewed along its longitudinal direction X. Moreover, the cross-sectional area of ​​the operating section 67 in the direction perpendicular to the longitudinal direction X is larger than the cross-sectional area of ​​the first paste storage chamber 49 in the direction perpendicular to the longitudinal direction X and the cross-sectional area of ​​the second paste storage chamber 49' in the direction perpendicular to the longitudinal direction X.

[0097] [Elastic Holder] As shown in Figure 2, the elastic holder 15 is loosely engaged with the holder engagement portion 79 of the first rod portion 69 and the holder engagement portion 79' of the second rod portion 69', one each. The elastic holder 15, together with the holder engagement portions 79 and 79', constitutes the tip of the plunger 5.

[0098] The elastic body holder 15 has an elliptical cross-sectional shape in a direction perpendicular to the longitudinal direction X, which is similar to the cross-sectional shape of the inner circumferential surface (inner flat surface portions 63A, 63B and inner curved surface portions 65A, 65B) of the first paste storage chamber 49 or the second paste storage chamber 49'. As shown in Figure 11A, the elastic body holder 15 has a body portion 81, a top portion 83, and a neck portion 85.

[0099] The body portion 81 is located at one end of the elastic body holder 15 and is a columnar portion whose cross-sectional shape in a direction perpendicular to the longitudinal direction X is elliptical. The bottom surface 81A of the body portion 81 has an engagement hole 81B into which the engagement projection 79B of the holder engagement portion 79 or the engagement projection 79B' of the holder engagement portion 79' is inserted.

[0100] The top portion 83 is located at the other end of the elastic body holder 15 and has a shape that tapers towards the tip. The neck portion 85 is formed between the body portion 81 and the top portion 83. The outer surface of the neck portion 85 is recessed compared to the body portion 81 and the top portion 83. The neck portion 85 and the body portion 81 and the top portion 83, which are opposite each other on either side of the neck portion 85, form an annular groove portion 81D to which the O-ring 17 is attached.

[0101] The cross-sectional shape of the body portion 81 in the direction perpendicular to the longitudinal direction X is smaller than the cross-sectional shape of the first paste storage chamber 49 (or the second paste storage chamber 49' (hereinafter the same)) and is an elliptical shape similar to the cross-sectional shape of the first paste storage chamber 49. That is, the outer circumferential surface 81C of the body portion 81 is aligned with the inner circumferential surface of the first paste storage chamber 49. Therefore, when the first rod portion 69 is inserted into the first paste storage chamber 49 and the elastic body holder 15 enters the first paste storage chamber 49, the distance from the outer circumferential surface 81C of the body portion 81 to the inner circumferential surface of the first paste storage chamber 49 becomes constant over the entire circumference of the body portion 81.

[0102] Furthermore, similar to the first paste storage chamber 49, in the cross-sectional shape of the elliptical body portion 81, when the length dimension W2 in the short axis direction is set to 1, it is preferable that the length dimension T2 in the long axis direction is set in the range of 1.1 to 2.0. In this embodiment, the length dimension T2 in the long axis direction is set to 1.3, with the length dimension W2 in the short axis direction being 1. In other words, the length dimension T2 in the long axis direction is set to 1.3 times the length dimension W2 in the short axis direction.

[0103] The cross-sectional shape of the neck portion 85 in the direction perpendicular to the longitudinal direction X is set to an elliptical shape similar to the cross-sectional shape of the first paste storage chamber 49, just like the body portion 81. Therefore, when the first rod portion 69 is inserted into the first paste storage chamber 49 and the elastic body holder 15 enters the first paste storage chamber 49, the distance from the outer peripheral surface 85C of the neck portion 85 to the inner peripheral surface of the first paste storage chamber 49 becomes constant over the entire circumference of the neck portion 85. Furthermore, 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 the elliptical shape of the body portion 81.

[0104] Figure 12 is a cross-sectional view of the elastic body holder 15 with the O-ring 17 attached to the groove 81D, cut at the neck portion 85 in a direction perpendicular to the longitudinal direction X. When viewed along the longitudinal direction X, the O-ring 17 is annular (perfect circle), but the cross-section of the neck portion 85 is elliptical. Therefore, when the O-ring 17 is attached to the groove 81D, it is stretched in the longitudinal direction (thickness direction Z) and becomes elliptical. The length dimension T3 of the elliptical O-ring 17 in the longitudinal direction is greater than the length dimension T2 of the elliptical body portion 81 in the longitudinal direction. Also, the length dimension W3 of the elliptical O-ring 17 in the minor direction is greater than the length dimension W2 of the elliptical body portion 81 in the minor direction. Therefore, the O-ring 17 is fixed to the groove 81D in a state where it protrudes outward from the outer circumferential surface 81C of the body portion 81. In other words, the O-ring 17 protrudes outward from the groove 81D.

[0105] Furthermore, in the O-ring 17, a stronger tensile force acts on region a, which is stretched in the longitudinal direction (thickness direction Z), than on region b, which is not stretched in the longitudinal direction (thickness direction Z). As a result, as shown in Figure 12, the wire diameter ΔA of the O-ring 17 in region a is thinner than the wire diameter ΔB in region b. In other words, when the O-ring 17 is attached to the elastic body holder 15, the wire diameter differs depending on the circumferential position. Note that "wire diameter of the O-ring 17" refers to the cross-sectional thickness of the O-ring 17. Because the wire diameter of the O-ring 17 differs depending on the circumferential position, the amount of O-ring 17 protruding from the groove 81D differs, and the amount of protrusion from the groove 81D is smaller in the parts with a thinner wire diameter (for example, region a).

[0106] Furthermore, the length dimension T3 in the long axis direction of the elliptical O-ring 17 is slightly larger than the length dimension T1 in the long axis direction of the elliptical shape of the inner surface of the first paste storage chamber 49. Also, the length dimension W3 in the short axis direction of the elliptical O-ring 17 is slightly larger than the length dimension W1 in the short axis direction of the elliptical shape of the inner surface of the first paste storage chamber 49 or the second paste storage chamber 49'. Therefore, when the elastic body holder 15 enters the first paste storage chamber 49, the O-ring 17 comes into contact with the inner surface of the first paste storage chamber 49. The O-ring 17 is then compressed by being sandwiched between the inner surface of the first paste storage chamber 49 and the outer surface 85C of the neck portion 85.

[0107] Figure 13 shows a schematic cross-sectional view of the elastic body holder 15 with the O-ring 17 attached to the groove 81D, when it is inserted into the first paste storage chamber 49 and cut at the neck portion 85 in a direction perpendicular to the longitudinal direction X, as well as schematic cross-sectional views of the width direction Y and thickness direction Z at that time. In Figure 13, the portion of the O-ring 17 that is compressed when it enters the first paste storage chamber 49 is shown in gray, and the state of the O-ring 17 before compression is shown by a dashed line.

[0108] As shown in Figure 13, when the plunger 5 is inserted into the syringe 3 with the O-ring 17 attached to the groove 81D, the O-ring 17 is compressed by being sandwiched between the inner circumferential surface of the first paste storage chamber 49 (inner flat surfaces 63A, 63B and inner curved surfaces 65A, 65B) and the outer circumferential surface 85C of the neck portion 85. Here, the wire diameter of the O-ring 17 differs depending on its position in the circumferential direction. The thinner the wire diameter of the O-ring 17, the less it protrudes from the groove 81D.

[0109] Therefore, as shown in Figure 13, the difference (ΔX1, ΔX2) between the distance Gd from the outer surface 85C of the neck portion 85 to the inner surface of the first paste storage chamber 49 and the wire diameter Wr of the O-ring 17 differs depending on the circumferential position of the O-ring 17. Consequently, the compression ratio of the O-ring 17 when it enters the first paste storage chamber 49 differs depending on its circumferential position.

[0110] In other words, when viewed along the longitudinal direction X, the O-ring 17 has an elliptical shape, and the region b with a thicker wire diameter protrudes more from the groove 81D than the region a with a thinner wire diameter. Therefore, the difference ΔX2 in region b is greater than the difference ΔX1 in region a. As a result, the O-ring 17 is pushed further into the first paste storage chamber 49 in region b than in region a. Consequently, the compression ratio of the O-ring 17 in region b is greater than the compression ratio in region a. As a result, the compression ratio of the elliptical O-ring 17 in the longitudinal direction (thickness direction Z) is greater than the compression ratio of the O-ring 17 in the minor direction (width direction Y).

[0111] Furthermore, because the compressibility of the O-ring 17 differs depending on its circumferential position, a difference in frictional force occurs between the O-ring 17 and the inner surface of the first paste storage chamber 49 depending on its circumferential position. In other words, the frictional force between the vertex 17A in the long axis direction of the elliptical O-ring 17 and the inner surface of the first paste storage chamber 49 is greater than the frictional force between the vertex 17B in the short axis direction of the elliptical O-ring 17 and the inner surface of the first paste storage chamber 49. Therefore, the paste injector 1 can easily adjust the ease of movement of the plunger 5 in the longitudinal direction while maintaining the sealing performance between the inner surface of the first paste storage chamber 49 and the O-ring 17 by adjusting the dimensions in the long axis direction of the elliptical cross-sectional shape of the first paste storage chamber 49 and the elliptical cross-sectional shape of the plunger 5 relative to the dimensions in the short axis direction.

[0112] Furthermore, it is preferable that the compressibility of the O-ring 17 in the longitudinal direction (compressibility in region b) is approximately 10 to 14%, and the compressibility in the short direction (compressibility in region a) is approximately 3 to 7%. Specifically, in this embodiment, the compressibility in the longitudinal direction is 12%, and the compressibility in the short direction is 5%. The compressibility C (%) is calculated by the following formula: C = (Wr - Gd) / Wr × 100 where, Wr is the wire diameter of the elastic body (O-ring 17) [mm] and Gd is the distance from the outer circumferential surface of the neck portion to the inner circumferential surface of the paste storage chamber [mm].

[0113] The elastic body holder 15 loosely engages with the holder engagement portion 79 and the holder engagement portion 79'. Therefore, when the elastic body holder 15 is inserted into the first paste storage chamber 49 together with the plunger body 13 with the O-ring 17 attached, the plunger body 13 is pushed in, causing the elastic body holder 15 to move longitudinally X along with the plunger body 13 within the first paste storage chamber 49 or the second paste storage chamber 49'. On the other hand, when the plunger body 13 is pulled back, the friction generated between the O-ring 17 and the first paste storage chamber 49 or the second paste storage chamber 49' separates the elastic body holder 15 from the holder engagement portion 79 and the holder engagement portion 79', leaving it behind in the first paste storage chamber 49 or the second paste storage chamber 49'. As a result, even if the plunger 5 is accidentally pulled back, air will not be drawn into the first paste storage chamber 49 or the second paste storage chamber 49' from the discharge port 51 or the discharge port 51'.

[0114] [Static Mixer] (Mixing Tip Body) The mixing tip body 19, in combination with the mixer housing 21, is a component that constitutes the inner member IM of the static mixer 7, which is the mounting member M. As shown in Figure 14A, the mixing tip body 19 comprises a base 87, a first insertion portion 89 (insertion portion) and a second insertion portion 89' (insertion portion), a pair of rotational engaging pieces 91, 91', a backflow prevention wall 35, and an element group 39.

[0115] The base portion 87 is a cylindrical part that fits inside the mixer casing 23, which is the outer casing OM. A flange portion 87C is formed on the outer circumference of the base portion 87, extending radially outward. The mixing tip body portion 19 fits into a groove (circumferential groove 103) formed on the inner circumferential surface of the mixer casing 23, which will be described later, through the flange portion 87C. The mixing tip body portion 19 is then fixed to the mixer casing 23 in a state that allows it to rotate relative to the central axis CA.

[0116] The first insertion portion 89 and the second insertion portion 89' and the pair of rotating engagement pieces 91, 91' are formed on the first end face 87A of the base portion 87 facing the syringe 3, and extend from the first end face 87A in the longitudinal direction X. The first insertion portion 89 is inserted into the first cylindrical portion 45 of the syringe 3 when the static mixer 7 is attached to the syringe 3. The second insertion portion 89' is inserted into the second cylindrical portion 45' of the syringe 3 when the static mixer 7 is attached to the syringe 3. A first paste passage 29 is formed inside the first insertion portion 89. A second paste passage 29' is formed inside the second insertion portion 89'.

[0117] The pair of rotating engagement pieces 91, 91' are portions that engage with the engagement grooves (a pair of first engagement grooves 105A, 105A', or a pair of second engagement grooves 105B, 105B') of the mixer casing 23, which will be described later.

[0118] The backflow prevention wall 35 extends along the central axis CA from the center of the second end face 87B opposite the first end face 87A of the base 87. The tip of the backflow prevention wall 35 is the paste confluence position JP. The element group 39 extends from the tip of the backflow prevention wall 35. The element group 39 is composed of a plurality of elements (eight in this embodiment) arranged along the central axis CA.

[0119] The first paste passage 29 is formed to continuously penetrate the first insertion portion 89 and the base portion 87. The inlet hole 29A is formed on the end face of the first insertion portion 89. The outlet hole 29B is formed on the second end face 87B of the base portion 87. The second paste passage 29' is formed to continuously penetrate the second insertion portion 89' and the base portion 87. The inlet hole 29A' is formed on the end face of the second insertion portion 89'. The outlet hole 29B' is formed on the second end face 87B of the base portion 87.

[0120] As described above, the inner surface of the first paste passage 29 has a distal surface 29C that is far from the central axis CA when viewed in a cross-section perpendicular to the thickness direction Z, and a proximal surface 29D that is close to the central axis CA. The inclination angle θ formed by the distal surface 29C and the straight line C1 that extends in the longitudinal direction X through the center point of the inflow hole 29A is set to 45° in this case.

[0121] (Mixer Housing) The mixer housing 21, in combination with the mixing tip body portion 19, is a component that constitutes the inner member IM of the static mixer 7, which is the mounting member M. As shown in Figure 16A, the mixer housing 21 comprises a base housing portion 93 and an element housing portion 37.

[0122] The base housing portion 93 has an end wall portion 93A and a peripheral wall portion 93B. The end wall portion 93A is a disc portion that covers the second end face 87B of the base portion 87 of the mixing tip body portion 19 when the mixer housing 21 is placed over the mixing tip body portion 19. The peripheral wall portion 93B rises from the edge of the end wall portion 93A and extends around the base portion 87 until its tip contacts the flange portion 87C.

[0123] A recess 93C is provided on the inner surface of the end wall portion 93A. The recess 93C faces the outflow holes 29B and 29B'. By placing the mixer housing 21 over the mixing tip body portion 19, an intermediate passage 31 is formed inside the inner member IM, partitioned by the base portion 87, the backflow prevention wall 35, and the recess 93C (see Figure 3A).

[0124] The element housing portion 37 is a cylindrical portion that extends longitudinally X from a through hole formed in the center of the end wall portion 93A of the base housing portion 93, with an open tip. When the mixer housing 21 is placed over the mixing tip main body portion 19, the element group 39 is inserted into the element housing portion 37, forming a mixing passage 33. A guide tip engagement groove 37A for fixing the guide tip 9 is formed on the outer circumference of the element housing portion 37.

[0125] (Mixer Outer Body) The mixer outer body 23 is a cylindrical member that constitutes the outer body OM of the static mixer 7, which is the mounting member M. The static mixer 7, which is the mounting member M, is formed by housing the inner member IM, consisting of the mixing tip body 19 and the mixer housing 21, and the mixer biasing member 24 inside the mixer outer body 23 (see Figure 3B). The mixer outer body 23 also rotates relative to the syringe 3 about the central axis CA.

[0126] As shown in Figure 18A and the like, the mixer casing 23 comprises a top wall portion 95, a first circumferential wall portion 97, and a second circumferential wall portion 99. The top wall portion 95 constitutes the top surface of the mixer casing 23. As shown in Figure 18C, when viewed along the longitudinal direction X, the outer periphery of the top wall portion 95 exhibits a regular hexagonal shape. The first circumferential wall portion 97 constitutes the circumferential surface of the mixer casing 23. The first circumferential wall portion 97 rises from the edge of the top wall portion 95 and surrounds the entire circumference of the top wall portion 95. The second circumferential wall portion 99 constitutes the circumferential surface of the mixer casing 23. The second circumferential wall portion 99 extends continuously from the first circumferential wall portion 97 via a step and surrounds the entire circumference of the top wall portion 95.

[0127] Furthermore, a first space K1 and a second space K2 are formed inside the mixer casing 23 (see Figures 19 to 20C). The first space K1 is the space enclosed by the top wall portion 95 and the first peripheral wall portion 97. The second space K2 is the space enclosed by the second peripheral wall portion 99. Inside the first space K1, the inner member IM, consisting of the mixing tip body portion 19 and the mixer housing 21, and the mixer biasing member 24 are housed in a state that allows them to rotate around the central axis CA. Also, inside the second space K2, with the inner member IM housed therein, one end 41A of the syringe 3 is inserted (see Figure 3A).

[0128] The top wall portion 95 covers the end wall portion 93A of the mixer housing 21 via the mixer biasing member 24. The top wall portion 95 faces the opening 23A into which the syringe 3 is inserted (see Figure 19). A top through-cylinder 101 is formed in the center of the top wall portion 95. The top through-cylinder 101 is a cylindrical portion that protrudes from the top wall portion 95 and penetrates the top wall portion 95. When the inner member IM, consisting of the mixing tip body portion 19 and the mixer housing 21, is housed in the mixer outer casing 23, the element housing portion 37 is exposed to the outside by passing through the top through-cylinder 101. Also, an arrow AR1 is engraved on the surface of the top wall portion 95 (see Figure 16B, etc.). The arrow AR1 functions as a mark indicating the position of the first recess 107A, which will be described later. The first recess 107A is one of the engaging portions 107, which will be described later.

[0129] When viewed along the longitudinal direction X, the first circumferential wall portion 97 has a regular hexagonal outer surface, as shown in Figure 18C. The inner circumferential surface of the first circumferential wall portion 97 has a circular shape when viewed along the longitudinal direction X, as shown in Figure 18D. The inner circumferential surface of the first circumferential wall portion 97 has a circumferential groove 103, a pair of first engaging grooves 105A, 105A', and a pair of second engaging grooves 105B, 105B'.

[0130] As shown in Figure 3A, the circumferential groove 103 is a recess into which the flange portion 87C of the mixing tip body portion 19 fits. The circumferential groove 103 extends in the circumferential direction (the rotational direction of the inner member IM).

[0131] One of the first engagement grooves 105A and the second engagement groove 105B is a recess into which one of the rotational engagement pieces 91 formed in the mixing tip body 19 engages. The other of the first engagement groove 105A' and the second engagement groove 105B' is a recess into which the other rotational engagement piece 91' formed in the mixing tip body 19 engages. The pair of first engagement grooves 105A, 105A' and the pair of second engagement grooves 105B, 105B' are arranged side by side along the circumferential direction (the rotational direction of the inner member IM) with a predetermined interval between them. Here, the pair of first engagement grooves 105A, 105A' are formed at positions facing each other in the thickness direction Z, with the central axis CA in between. The pair of second engagement grooves 105B, 105B' are formed at positions facing each other in a direction shifted circumferentially from the thickness direction Z, with the central axis CA in between.

[0132] When assembled as a static mixer 7, the mixing tip body 19 and the mixer housing 21 rotate relative to the mixer casing 23 about the central axis CA. At this time, depending on the rotational positional relationship between the mixing tip body 19 and the mixer housing 21 and the mixer casing 23, one rotational engaging piece 91 engages with either the first engaging groove 105A or the second engaging groove 105B, and the other rotational engaging piece 91' engages with either the other first engaging groove 105A' or the second engaging groove 105B'. This determines the relative rotational position of the mixing tip body 19 and the mixer housing 21 and the mixer casing 23.

[0133] When viewed along the longitudinal direction X, the second circumferential wall portion 99, as shown in Figure 18C, has an outer surface that curves in an arc shape centered on the central axis CA, and a portion of it has a teardrop shape that points outward. The pointed portion of the outer surface of the second circumferential wall portion 99 is called the sharpened portion 99a. The tip of the sharpened portion 99a coincides with the direction pointed to by the arrow AR1 formed on the top wall portion 95. A projection 99b is also formed on the sharpened portion 99a. The projection 99b is the end face of the second circumferential wall portion 99, that is, the portion that protrudes along the longitudinal direction X from the opening 23A of the mixer casing 23 into which the syringe 3 is inserted. The circumferential position of the projection 99b with respect to the central axis CA coincides with the position where the first recess 107A, one of the engaging portions 107, is formed.

[0134] Furthermore, a stepped portion 98, a second stepped portion 98A, an engaging portion 107 (see Figures 3A, 21, etc.), and a restricting portion 108 are formed on the inner surface of the second peripheral wall portion 99. In addition, a first window portion 109A, a second window portion 109B, and a third window portion 109C are formed on the second peripheral wall portion 99.

[0135] The stepped portion 98 is a stepped ridge that narrows the inner diameter of the mixer casing 23 toward the top wall portion 95. The stepped portion 98 is formed at the boundary between the first circumferential wall portion 97 and the second circumferential wall portion 99. The stepped portion 98 extends in the circumferential direction (the rotational direction of the inner member IM). When the static mixer 7 is attached to the syringe 3, the circular wall portion 44 of the syringe 3 abuts against the stepped portion 98 (see Figure 3A).

[0136] The second stepped portion 98A is a stepped protrusion that narrows the inner diameter of the mixer casing 23 toward the top wall portion 95. The second stepped portion 98A is formed closer to the end face 99B of the second circumferential wall portion 99 than the stepped portion 98. The second stepped portion 98A extends in the circumferential direction (the rotational direction of the inner member IM). When the static mixer 7 is attached to the syringe 3, the end face 42a of the shoulder portion 42 formed on the outer circumferential surface of the syringe 3 abuts against the second stepped portion 98A (see Figure 3A).

[0137] The engaging portion 107 constitutes an engaging structure that fixes the mounting member M to one end 41A of the syringe 3. That is, the engaging portion 107 is the part that engages with the engaged portion 46 (first projection 46A, second projection 46B, third projection 46C) of the syringe 3. The engaging portion 107 is composed of a first recess 107A (recess), a second recess 107B (recess), and a third recess 107C (recess) formed on the inner surface of the second peripheral wall portion 99. The first recess 107A, the second recess 107B, and the third recess 107C are all formed by recessing a part of the inner surface of the second peripheral wall portion 99.

[0138] The first recess 107A has a first longitudinal groove 107Aa (first groove) and a first transverse groove 107Ab (second groove). As shown in Figures 20A, 20C, etc., the first longitudinal groove 107Aa is a recess that cuts out a part of the second stepped portion 98A and extends along the longitudinal direction X (central axis CA) to the stepped portion 98. The first transverse groove 107Ab is a recess that extends circumferentially along the stepped portion 98 from the closed end of the first longitudinal groove 107Aa (the end on the stepped portion 98 side). The bottom surface of the first transverse groove 107Ab facing the stepped portion 98 is inclined such that the groove width in the longitudinal direction X gradually narrows from the side of the first longitudinal groove 107Aa (see Figure 20A, etc.).

[0139] The second recess 107B has a second longitudinal groove 107Ba (first groove) and a second transverse groove 107Bb (second groove). As shown in Figures 19 and 20B, the second longitudinal groove 107Ba is a recess that cuts out a part of the second stepped portion 98A and extends along the longitudinal direction X (central axis CA) to the stepped portion 98. The second transverse groove 107Bb is a recess that extends circumferentially along the stepped portion 98 from the closed end of the second longitudinal groove 107Ba (the end on the stepped portion 98 side). The bottom surface of the second transverse groove 107Bb facing the stepped portion 98 is inclined such that the groove width in the longitudinal direction X gradually narrows from the second longitudinal groove 107Ba side (see Figure 19).

[0140] The third recess 107C has a third longitudinal groove 107Ca (first groove) and a third transverse groove 107Cb (second groove). As shown in Figure 20B, the third longitudinal groove 107Ca is a recess that cuts out a part of the second stepped portion 98A and extends along the longitudinal direction X (central axis CA) to the stepped portion 98. The third transverse groove 107Cb is a recess that extends circumferentially along the stepped portion 98 from the closed end of the third longitudinal groove 107Ca (the end on the stepped portion 98 side). The bottom surface of the third transverse groove 107Cb facing the stepped portion 98 is inclined such that the groove width in the longitudinal direction X gradually narrows from the third longitudinal groove 107Ca side (see Figure 20B).

[0141] Furthermore, the first indentation 107A, the second indentation 107B, and the third indentation 107C are aligned along the rotational direction of the mixer casing 23. Also, when viewed along the longitudinal direction X, the first indentation 107A, the second indentation 107B, and the third indentation 107C are asymmetrical with respect to the central axis CA, which is the rotational center of the mixer casing 23. Furthermore, the first indentation 107A, the second indentation 107B, and the third indentation 107C are aligned at non-equal intervals along the rotational direction of the mixer casing 23.

[0142] Specifically, the first recess 107A is formed on the inner surface of the second circumferential wall portion 99 at a position corresponding to the sharp portion 99a of the outer surface of the second circumferential wall portion 99 when viewed along the longitudinal direction X. The second recess 107B and the third recess 107C are formed on the inner surface of the second circumferential wall portion 99 at a position corresponding to the flat portion of the outer surface of the first circumferential wall portion 97 when viewed along the longitudinal direction X (see Figures 18C and 18D).

[0143] Furthermore, the first recess 107A has a shape into which the first projection 46A can be inserted. The second recess 107B has a shape into which the second projection 46B can be inserted. The third recess 107C has a shape into which the third projection 46C can be inserted. For this reason, the first recess 107A, the second recess 107B, and the third recess 107C each have different shapes when viewed along the longitudinal direction X.

[0144] When the static mixer 7 is fixed to one end 41A of the syringe 3, the restricting portion 108 engages with the restricting projection 43a, which is the restricted portion, and restricts the rotation of the mixer casing 23 relative to the syringe 3. The restricting portion 108 is composed of a restricting recess 108a, a first vertical groove 107Aa, and a remaining portion 108b.

[0145] The restricting recess 108a is a recess in the inner surface of the second circumferential wall portion 99. The restricting recess 108a is formed by cutting out a portion of the inner surface of the second circumferential wall portion 99 between the second stepped portion 98A and the stepped portion 98. The restricting recess 108a extends along the longitudinal direction X. Furthermore, when viewed along the longitudinal direction X, the restricting recess 108a is formed between the first longitudinal groove portion 107Aa of the first recess 107A and the second longitudinal groove portion 107Ba of the second recess 107B.

[0146] The remaining portion 108b is located on the inner surface of the second peripheral wall portion 99, between the regulating recess 108a and the first vertical groove portion 107Aa of the first recess 107A, and is the portion that protrudes into the second space K2 more than the regulating recess 108a and the first vertical groove portion 107Aa. Here, as shown in Figure 21, the side surface of the remaining portion 108b on the regulating recess 108a side is inclined to gradually bulge outwards toward the first recess 107A side. In addition, the side surface of the remaining portion 108b on the first recess 107A side is upright along the radial direction centered on the central axis CA.

[0147] The first window portion 109A is a hole that penetrates the second peripheral wall portion 99 in the radial direction centered on the central axis CA. The first window portion 109A is formed in correspondence with the first transverse groove portion 107Ab. That is, the first transverse groove portion 107Ab is formed by the edge of the first window portion 109A.

[0148] The second window portion 109B is a hole that penetrates the second peripheral wall portion 99 in the radial direction centered on the central axis CA. The second window portion 109B is formed in correspondence with the second transverse groove portion 107Bb. That is, the second transverse groove portion 107Bb is formed by the edge of the second window portion 109B.

[0149] The third window portion 109C is a hole that penetrates the second peripheral wall portion 99 in the radial direction centered on the central axis CA. The third window portion 109C is formed in correspondence with the third transverse groove portion 107Cb. That is, the third transverse groove portion 107Cb is formed by the edge of the third window portion 109C.

[0150] Furthermore, the mixer casing 23 has a cylindrical wall portion 98B that rises from the edge of the second stepped portion 98A along the longitudinal direction X and forms the opening 23A of the mixer casing 23. The cylindrical wall portion 98B is a cylindrical wall surface that surrounds the shoulder portion 42 formed on the outer circumferential surface of the syringe 3 when the static mixer 7 is attached to the syringe 3. As the cylindrical wall portion 98B rises from the edge of the second stepped portion 98A, the first longitudinal groove portion 107Aa, the second longitudinal groove portion 107Ba, and the third longitudinal groove portion 107Ca are each opened inside the cylindrical wall portion 98B. In other words, the cylindrical wall portion 98B protrudes further along the longitudinal direction X than the engaging portion 107.

[0151] (Mixer biasing member) As shown in Figure 3A, the mixer biasing member 24 is a plastic leaf spring sandwiched between the mixer outer casing 23 (outer casing OM) and the mixer housing 21 (inner member IM). The mixer biasing member 24 is formed in an annular shape that surrounds the cylindrical passage (mixing passage 33) through which the paste passes, which is composed of the element housing portion 37 and the element group 39. Furthermore, as shown in Figure 22A, etc., the mixer biasing member 24 has a plate-like shape with a first surface 24A facing the mixer outer casing 23 and a second surface 24B facing the mixer housing 21.

[0152] Furthermore, a projection 24a on the outer casing side is formed on the first surface 24A. The projection 24a on the outer casing side is a portion that protrudes in the longitudinal direction X from the first surface 24A toward the mixer outer casing 23. The tip of the projection 24a on the outer casing side contacts the inner surface of the mixer outer casing 23. In this embodiment, the projection 24a on the outer casing side includes an outer peripheral projection 24a1 and an inner peripheral projection 24a2. The outer peripheral projection 24a1 is formed on the outer periphery of the mixer biasing member 24. The inner peripheral projection 24a2 is formed on the inner periphery of the mixer biasing member 24. Both the outer peripheral projection 24a1 and the inner peripheral projection 24a2 extend around the entire circumference of the mixer biasing member 24 and have an annular shape.

[0153] Furthermore, an inner member-side projection 24b is formed on the second surface 24B. The inner member-side projection 24b is a portion that protrudes from the second surface 24B toward the mixer housing 21 in the longitudinal direction X. The tip of the inner member-side projection 24b contacts the mixer housing 21. Also, the inner member-side projection 24b is formed in a position that does not overlap with the outer body-side projection 24a when viewed along the longitudinal direction X. In this embodiment, the inner member-side projection 24b includes an intermediate projection 24b1. The intermediate projection 24b1 is formed between the outer and inner periphery of the second surface 24B. The intermediate projection 24b1 extends around the entire circumference of the mixer biasing member 24 and has an annular shape.

[0154] [Guide Tip] Figure 35 is a side view and a cross-sectional view of the guide tip 9. Figure 36 is a side view and a cross-sectional view of the guide tip 9 in a bent state. The guide tip 9 is mounted on the outside of the static mixer 7 and is configured to be bendable. It is desirable that the guide tip 9 has flexibility that allows it to bend into a predetermined shape, and that the guide tip 9 can be bent to a desired angle. Flexibility means that it can bend smoothly under external forces such as bending forces without buckling. It is also desirable that the guide tip 9 has shape retention that allows it to maintain its shape after bending, and that the guide tip 9 does not easily return to its original state due to paste discharge pressure, etc., and that the paste is discharged smoothly. Shape retention means that it can maintain its bent state even after the external force is released. The guide tip 9 can be bent to fill the affected area, such as a tooth cavity, with paste from various angles, and it is sufficient that it can maintain its bent state during filling, so it may be configured to return to its original state when the external force is released. It is also desirable that the inner circumferential surface of the guide tip 9, through which the paste passes, is smooth before and after bending.

[0155] The guide tip 9 of this embodiment comprises a mounting portion 9A and a guide portion 9B. The mounting portion 9A is a cylindrical portion that extends in the longitudinal direction X and has an open rear end. The shape of the inner circumferential surface of the mounting portion 9A corresponds to the shape of the outer circumferential surface of the element housing portion 37. The mounting portion 9A is detachably mounted on the outside of the static mixer 7, more specifically on the outer circumferential surface of the element housing portion 37. The mounting portion 9A comprises an insertion hole 9C into which the outer circumferential surface of the element housing portion 37 is inserted, and a first paste discharge passage 9D that communicates with the mixing passage 33 when the element housing portion 37 is inserted into the insertion hole 9C. An engaging projection 9E that engages with the guide tip engaging groove 37A is formed on the inner circumferential surface of the insertion hole 9C. Note that the static mixer 7 and the guide tip 9 do not necessarily need to be provided with the guide tip engaging groove 37A and the engaging projection 9E. However, with these features in place, the guide tip 9 can be properly attached to the static mixer 7 without being easily separated by the paste outflow pressure, external forces, etc.

[0156] The guide portion 9B is a member that guides the paste to the affected area, such as a cavity in the tooth. The guide portion 9B is formed from a tubular member that extends diagonally upward from the tip of the mounting portion 9A in a direction intersecting the direction in which the mounting portion 9A extends. The guide portion 9B includes a second paste discharge path 9F that communicates with the first paste discharge path 9D, and a discharge port 9G formed at the tip of the second paste discharge path 9F for dispensing paste.

[0157] In this embodiment, the guide tip 9 has a bendable portion of the guide section 9B. On the outer circumferential surface between the approximate center of the longitudinal direction of the guide section 9B and the rear end on the mounting section 9A side, one or more sets of bendable thin-walled portions 9H and non-bendable thick-walled portions 9I are provided in succession, specifically six sets. These six sets of thin-walled portions 9H and thick-walled portions 9I constitute a bendable portion 9J. Of the six thick-walled portions 9I, the outer diameter of the thick-walled portion 9I at the rear end closest to the mounting section 9A is the largest, and the outer diameter of the thick-walled portions 9I gradually decreases from the rear end towards the front end. This configuration makes the rear end of the guide section 9B more robust. The outer circumferential surface of the guide section 9B has irregularities due to these thin-walled portions 9H and thick-walled portions 9I. In contrast, the inner circumferential surface of the guide section 9B, which is the inner circumferential surface of the second paste discharge path 9F, is smooth and free of irregularities along its entire length.

[0158] Furthermore, since the guide portion 9B is flexible, it is not limited to being formed from a tubular member extending in a direction intersecting the direction in which the mounting portion 9A extends, but may also be formed from a tubular member extending in the same direction as the mounting portion 9A extends. In addition, the guide tip 9 may have thin-walled portions 9H and thick-walled portions 9I alternately provided along the entire length of the guide portion 9B, and the entire guide portion 9B, including the portions other than the thin-walled and thick-walled portions, may be flexible. The material of the guide tip 9 is not particularly limited and may be the same material as the static mixer 7 or a different material. The material of the guide tip 9 is preferably resin. Suitable resins for use in the guide tip 9 include, for example, polyacetal, polypropylene, and polyetherethyl ketone.

[0159] [Attachment and Bending of Guide Tip] To attach the guide tip 9 to the static mixer 7, as shown in Figure 1, the user inserts the tip of the element housing portion 37 into the insertion hole 9C of the mounting portion 9A and engages the engaging projection 9E with the guide tip engaging groove 37A. This fixes the guide tip 9 to the element housing portion 37, and the mixing passage 33, the first paste discharge passage 9D and the second paste discharge passage 9F are connected, forming a paste discharge passage.

[0160] In the state before bending of the guide portion 9B shown in Figure 35, when a user applies bending force to the bending portion 9J with their hand or the like, the thin-walled portion 9H bends. As a result, as shown in Figure 36, the bending portion 9J bends, and the guide portion 9B is changed to the desired angle. In addition, the adjacent thick-walled portions 9I abut against each other, which suppresses excessive bending, appropriately preventing buckling of the guide portion 9B or blockage of the second paste discharge passage 9F, while maintaining the smoothness of the inner circumferential surface. That is, the inner circumferential surface of the guide portion 9B is smooth before and after bending.

[0161] Here, the bent portion 9J can also be a bellows structure or corrugated structure with repeated valley folds and mountain folds, as in Reference 1. However, if irregularities are formed on the inner surface of the bent portion 9J, the cross-sectional area of ​​the paste dispensing path may become uneven, affecting the fluidity of the paste and making it difficult for the user to control the amount of paste dispensed. For this reason, by having a smooth inner surface as in this embodiment, the user can dispense the paste more smoothly in an appropriate amount.

[0162] [Cap] The cap 11 is fixed to one end 41A of the syringe 3 in place of the static mixer 7 when storing or transporting the paste injector 1. Components that are common to the static mixer 7 may be given the same component name and their explanation may be omitted.

[0163] (Cap Inner Member) The cap inner member 25 is a component of the inner member IM of the cap 11, which is the mounting member M. The cap inner member 25 is a component that corresponds to the mixing tip body 19 and the mixer housing 21, which are the inner members IM of the static mixer 7.

[0164] As shown in Figure 24A, the inner cap member 25 comprises a base portion 111, a first insertion portion 113 (insertion portion) and a second insertion portion 113' (insertion portion), and a pair of rotatable engagement pieces 115, 115'.

[0165] The base portion 111 is a cylindrical part that fits inside the cap outer casing 27, which is the outer casing OM. A flange portion 117C extending radially outward is formed on the outer circumference of the base portion 111. The inner cap member 25 has its flange portion 117C fitted into a groove (circumferential groove 125) formed on the inner circumferential surface of the cap outer casing 27, which will be described later. The inner cap member 25 is then fixed to the cap outer casing 27 in a state that allows it to rotate relative to the cap outer casing 27 about its central axis CA.

[0166] The first insertion portion 113 and the second insertion portion 113' and the pair of rotating engagement pieces 115, 115' are formed on the first end face 111A of the base portion 111 facing the syringe 3, and extend from the first end face 111A in the longitudinal direction X. The first insertion portion 113 is inserted into the first cylindrical portion 45 of the syringe 3 when the cap 11 is attached to the syringe 3. The second insertion portion 113' is inserted into the second cylindrical portion 45' of the syringe 3 when the cap 11 is attached to the syringe 3. Unlike the mixing tip body portion 19, the first insertion portion 113 and the second insertion portion 113' have a solid columnar shape (lid shape) that can seal the outlets 51, 51' of the syringe 3. In other words, the first insertion portion 113 and the second insertion portion 113' do not have passages formed inside.

[0167] The pair of rotating engagement pieces 115, 115' are portions that 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 outer casing 27, which will be described later.

[0168] On the second end face 111B opposite to the first end face 111A of the base portion 111, a pair of first bottomed recesses 117A, 117A and a pair of second bottomed recesses 117B, 117B are formed. The pair of first bottomed recesses 117A, 117A and the pair of second bottomed recesses 117B, 117B are formed alternately along the circumferential direction when viewed along the longitudinal direction X. In addition, a pair of through holes 117Bb, 117Bb are formed at the bottom of the pair of second bottomed recesses 117B, 117B.

[0169] (Cap Outer Body) The cap outer body 27 is a cylindrical member that constitutes the outer body OM of the cap 11, which is the mounting member M. The cap outer body 27 is a member that corresponds to the mixer outer body 23, which is the outer body OM of the static mixer 7. The cap 11, which is the mounting member M, is formed by housing the inner member IM, which consists of the cap inner member 25, and the cap biasing member 28 inside the cap outer body 27 (see Figure 3B). The cap outer body 27 also rotates relative to the syringe 3 about the central axis CA.

[0170] As shown in Figure 26A and the like, the cap casing 27 comprises a top wall portion 119, a first circumferential wall portion 121, and a second circumferential wall portion 123. The top wall portion 119 constitutes the top surface of the cap casing 27. As shown in Figure 26C, when viewed along the longitudinal direction X, the outer periphery of the top wall portion 119 exhibits a regular hexagonal shape. The first circumferential wall portion 121 constitutes the circumferential surface of the cap casing 27. The first circumferential wall portion 121 rises from the edge of the top wall portion 119 and surrounds the entire circumference of the top wall portion 119. The second circumferential wall portion 123 constitutes the circumferential surface of the cap casing 27. The second circumferential wall portion 123 extends continuously from the first circumferential wall portion 121 via a step and surrounds the entire circumference of the top wall portion 119.

[0171] Furthermore, a first space K1 and a second space K2 are formed inside the cap outer casing 27 (see Figures 27 to 28C). The first space K1 is the space enclosed by the top wall portion 119 and the first peripheral wall portion 121. The second space K2 is the space enclosed by the second peripheral wall portion 123. Inside the first space K1, the inner member IM, which consists of the cap inner member 25, and the cap biasing member 28 are housed in a state that allows them to rotate around the central axis CA. Also, inside the second space K2, with the inner member IM housed, one end 41A of the syringe 3 is inserted.

[0172] The top wall portion 119 covers the second end face 111B of the cap inner member 25 via the cap biasing member 28. The top wall portion 119 faces the opening 27A into which the syringe 3 is inserted (see Figure 27). Unlike the mixing tip body portion 19, the top wall portion 119 is made of a curved plate member. In other words, the top wall portion 119 does not have a top through tube formed in the center. Also, an arrow AR2 is engraved on the surface of the top wall portion 119 (see Figure 26C, etc.). The arrow AR2 functions as a mark indicating the position of the first recess 129A, which will be described later. The first recess 129A is one of the engaging portions 129, which will be described later.

[0173] When viewed along the longitudinal direction X, the first circumferential wall portion 121 has a regular hexagonal outer surface, as shown in Figure 26C. The inner circumferential surface of the first circumferential wall portion 121 has a circular shape when viewed along the longitudinal direction X, as shown in Figure 26D. The inner circumferential surface of the first circumferential wall portion 121 has a circumferential groove 125, a pair of first engagement grooves 127A, 127A', and a pair of second engagement grooves 127B, 127B' formed thereon.

[0174] The circumferential groove 125 is a recess into which the flange portion 117C of the inner cap member 25 fits. The circumferential groove 125 extends in the circumferential direction (the rotational direction of the inner cap member 25).

[0175] One of the first engaging grooves 127A and the second engaging groove 127B is a recess formed in the inner cap member 25 into which one of the rotational engaging pieces 115 engages. The other of the first engaging grooves 127A' and the second engaging groove 127B' is a recess formed in the inner cap member 25 into which the other rotational engaging piece 115' engages. The pair of first engaging grooves 127A, 127A' and the pair of second engaging grooves 127B, 127B' are arranged side by side along the circumferential direction (the rotational direction of the inner cap member 25) with a predetermined interval between them. Here, the pair of first engaging grooves 127A, 127A' are formed at positions facing each other in the thickness direction Z, with the central axis CA in between. The pair of second engaging grooves 127B, 127B' are formed at positions facing each other in a direction shifted circumferentially from the thickness direction Z, with the central axis CA in between.

[0176] When assembled as cap 11, the inner cap member 25 rotates relative to the outer cap body 27 about the central axis CA. At this time, depending on the rotational positional relationship between the inner cap member 25 and the outer cap body 27, one rotational engaging piece 115 engages with either the first engaging groove 127A or the second engaging groove 127B, and the other rotational engaging piece 115' engages with either the other first engaging groove 127A' or the second engaging groove 127B'. This determines the relative rotational position of the inner cap member 25 and the outer cap body 27.

[0177] When viewed along the longitudinal direction X, the second circumferential wall portion 123, as shown in Figure 26C, has an outer surface that curves in an arc shape centered on the central axis CA, and a portion of it has a teardrop shape that points outward. The pointed portion of the outer surface of the second circumferential wall portion 123 is called the sharpened portion 123a. The tip of the sharpened portion 123a coincides with the direction pointed to by the arrow AR2 formed on the top wall portion 119. A projection 123b is also formed on the sharpened portion 123a. The projection 123b is the end face of the second circumferential wall portion 123, that is, the portion that protrudes along the longitudinal direction X from the opening 27A of the cap housing 27 into which the syringe 3 is inserted. The circumferential position of the projection 123b, centered on the central axis CA, coincides with the position where the first recess 129A, one of the engaging portions 129, is formed.

[0178] Furthermore, the inner surface of the second peripheral wall portion 123 has a stepped portion 120, a second stepped portion 120A, an engaging portion 129 (see Figure 29, etc.), and a restricting portion 130. In addition, the second peripheral wall portion 123 has a first window portion 131A, a second window portion 131B, and a third window portion 131C.

[0179] The stepped portion 120 is a stepped ridge that narrows the inner diameter of the cap outer casing 27 toward the top wall portion 119. The stepped portion 120 is formed at the boundary between the first circumferential wall portion 121 and the second circumferential wall portion 123. The stepped portion 120 extends in the circumferential direction (the rotational direction of the inner member IM). When the cap 11 is attached to the syringe 3, the circular wall portion 44 of the syringe 3 abuts against the stepped portion 120.

[0180] The second stepped portion 120A is a stepped surface that narrows the inner diameter of the cap outer casing 27 toward the top wall portion 119. The second stepped portion 120A is formed closer to the end face 123B of the second circumferential wall portion 123 than the stepped portion 120. The second stepped portion 120A extends in the circumferential direction (the rotational direction of the inner member IM). When the cap 11 is attached to the syringe 3, the end face 42a of the shoulder portion 42 formed on the outer circumferential surface of the syringe 3 abuts against the second stepped portion 120A.

[0181] The engaging portion 129 constitutes an engagement structure that fixes the mounting member M to one end 41A of the syringe 3. That is, the engaging portion 129 is the part that engages with the engaged portion 46 (first projection 46A, second projection 46B, third projection 46C) of the syringe 3. The engaging portion 129 is composed of a first recess 129A (recess), a second recess 129B (recess), and a third recess 129C (recess) formed on the inner surface of the second peripheral wall portion 123. The first recess 129A (recess), the second recess 129B (recess), and the third recess 129C (recess) are all formed by recessing a part of the inner surface of the second peripheral wall portion 123.

[0182] The first recess 129A has a first longitudinal groove 129Aa (first groove) and a first transverse groove 129Ab (second groove). As shown in Figures 28A, 28C, etc., the first longitudinal groove 129Aa is a recess that cuts out a part of the second stepped portion 120A and extends along the longitudinal direction X (central axis CA) to the stepped portion 120. The first transverse groove 129Ab is a recess that extends circumferentially along the stepped portion 120 from the closed end of the first longitudinal groove 129Aa (the end on the stepped portion 120 side). The bottom surface of the first transverse groove 129Ab facing the stepped portion 120 is inclined such that the groove width in the longitudinal direction X gradually narrows from the side of the first longitudinal groove 129Aa (see Figure 28A, etc.).

[0183] The second recess 129B has a second longitudinal groove 129Ba (first groove) and a second transverse groove 129Bb (second groove). As shown in Figures 27, 28B, etc., the second longitudinal groove 129Ba is a recess that cuts out a part of the second stepped portion 120A and extends along the longitudinal direction X (central axis CA) to the stepped portion 120. The second transverse groove 129Bb is a recess that extends circumferentially along the stepped portion 120 from the closed end of the second longitudinal groove 129Ba (the end on the stepped portion 120 side). The bottom surface of the second transverse groove 129Bb facing the stepped portion 120 is inclined such that the groove width in the longitudinal direction X gradually narrows from the second longitudinal groove 129Ba side (see Figure 27).

[0184] The third recess 129C has a third longitudinal groove 129Ca (first groove) and a third transverse groove 129Cb (second groove). As shown in Figure 28B, the third longitudinal groove 129Ca is a recess that cuts out a part of the second stepped portion 120A and extends along the longitudinal direction X (central axis CA) to the stepped portion 120. The third transverse groove 129Cb is a recess that extends circumferentially along the stepped portion 120 from the closed end of the third longitudinal groove 129Ca (the end on the stepped portion 120 side). The bottom surface of the third transverse groove 129Cb facing the stepped portion 120 is inclined such that the groove width in the longitudinal direction X gradually narrows from the third longitudinal groove 129Ca side (see Figure 28B).

[0185] Furthermore, the first indentation 129A, the second indentation 129B, and the third indentation 129C are aligned along the rotational direction of the cap casing 27. Also, when viewed along the longitudinal direction X, the first indentation 129A, the second indentation 129B, and the third indentation 129C are asymmetrical with respect to the central axis CA, which is the rotational center of the cap casing 27. Furthermore, the first indentation 129A, the second indentation 129B, and the third indentation 129C are aligned at non-equal intervals along the rotational direction of the cap casing 27.

[0186] In other words, the first recess 129A is formed on the inner surface of the second circumferential wall portion 123 at a position corresponding to the sharp portion 123a of the outer surface of the second circumferential wall portion 123 when viewed along the longitudinal direction X. The second recess 129B and the third recess 129C are formed on the inner surface of the second circumferential wall portion 123 at a position corresponding to the flat portion of the outer surface of the first circumferential wall portion 121 when viewed along the longitudinal direction X (see Figures 26C and 26D).

[0187] Furthermore, the first recess 129A has a shape into which the first projection 46A can be inserted. The second recess 129B has a shape into which the second projection 46B can be inserted. The third recess 129C has a shape into which the third projection 46C can be inserted. For this reason, the first recess 129A, the second recess 129B, and the third recess 129C each have different shapes when viewed along the longitudinal direction X.

[0188] The restricting portion 130 engages with the restricting projection 43a, which is the restricted portion, when the cap 11 is fixed to one end 41A of the syringe 3, thereby restricting the rotation of the cap casing 27 relative to the syringe 3. The restricting portion 130 is composed of a restricting recess 130a, a first vertical groove 129Aa, and a remaining portion 130b.

[0189] The restrictive recess 130a is a recess in the inner surface of the second circumferential wall portion 123. The restrictive recess 130a is formed by cutting out a portion of the inner surface of the second circumferential wall portion 123 between the second stepped portion 120A and the stepped portion 120. The restrictive recess 130a extends along the longitudinal direction X. Furthermore, when viewed along the longitudinal direction, the restrictive recess 130a is formed between the first vertical groove portion 129Aa of the first recess 129A and the second vertical groove portion 129Ba of the second recess 129B.

[0190] The remaining portion 130b is located on the inner surface of the second peripheral wall portion 123, between the regulating recess 130a and the first vertical groove portion 129Aa of the first recess 129A, and is the portion that protrudes into the second space K2 more than the regulating recess 130a and the first vertical groove portion 129Aa. Here, as shown in Figure 29, the side surface of the remaining portion 130b on the regulating recess 130a side is inclined to gradually bulge outwards toward the first recess 129A side. Also, the side surface of the remaining portion 130b on the first recess 129A side is upright along the radial direction centered on the central axis CA.

[0191] The first window portion 131A is a hole that penetrates the second peripheral wall portion 123 in the radial direction centered on the central axis CA. The first window portion 131A is formed in correspondence with the first transverse groove portion 129Ab. That is, the first transverse groove portion 129Ab is formed by the edge of the first window portion 131A.

[0192] The second window portion 131B is a hole that penetrates the second peripheral wall portion 123 in the radial direction centered on the central axis CA. The second window portion 131B is formed in correspondence with the second transverse groove portion 129Bb. That is, the second transverse groove portion 129Bb is formed by the edge of the second window portion 131B.

[0193] The third window portion 131C is a hole that penetrates the second peripheral wall portion 123 in the radial direction centered on the central axis CA. The third window portion 131C is formed in correspondence with the third transverse groove portion 129Cb. That is, the third transverse groove portion 129Cb is formed by the edge of the third window portion 131C.

[0194] Furthermore, the cap casing 27 has a cylindrical wall portion 120B that rises from the edge of the second stepped portion 120A along the longitudinal direction X and forms the opening 27A of the cap casing 27. The cylindrical wall portion 120B is a cylindrical wall surface that surrounds the shoulder portion 42 formed on the outer circumferential surface of the syringe 3 when the cap 11 is attached to the syringe 3. As the cylindrical wall portion 120B rises from the edge of the second stepped portion 120A, the first longitudinal groove portion 129Aa, the second longitudinal groove portion 129Ba, and the third longitudinal groove portion 129Ca are each opened on the inside of the cylindrical wall portion 120B. In other words, the cylindrical wall portion 120B protrudes more than the engaging portion 129 along the longitudinal direction X.

[0195] (Cap biasing member) The cap biasing member 28 is a plastic leaf spring sandwiched between the cap outer casing 27 (outer casing OM) and the cap inner member 25 (inner member IM), as shown in Figure 3B. The cap biasing member 28 has an annular plate shape, as shown in Figure 30A, having a first surface 28A facing the cap outer casing 27 and a second surface 28B facing the cap inner member 25.

[0196] Furthermore, a projection 28a on the outer casing side is formed on the first surface 28A. The projection 28a on the outer casing side is a portion that protrudes in the longitudinal direction X from the first surface 28A toward the cap outer casing 27. The tip of the projection 28a on the outer casing side contacts the inner surface of the cap outer casing 27. In this embodiment, the projection 28a on the outer casing side includes an outer peripheral projection 28a1 and an inner peripheral projection 28a2. The outer peripheral projection 28a1 is formed on the outer periphery of the cap biasing member 28. The inner peripheral projection 28a2 is formed on the inner periphery of the cap biasing member 28. Both the outer peripheral projection 28a1 and the inner peripheral projection 28a2 extend around the entire circumference of the cap biasing member 28 and have an annular shape.

[0197] Furthermore, an inner member side projection 28b is formed on the second surface 28B. The inner member side projection 28b is a portion that protrudes in the longitudinal direction X from the second surface 28B toward the cap inner member 25. The tip of the inner member side projection 28b contacts the cap inner member 25. Also, the inner member side projection 28b is formed in a position that does not overlap with the outer body side projection 28a when viewed along the longitudinal direction X. In this embodiment, the inner member side projection 28b includes an intermediate projection 28b1. The intermediate projection 28b1 is formed between the outer and inner periphery of the second surface 28B. The intermediate projection 28b1 extends around the entire circumference of the cap biasing member 28 and has an annular shape.

[0198] [Details on fixing the mounting member] Using Figures 32, 33, 34, and 3A, the details of how the mounting member M is fixed to the syringe 3 will be explained using the static mixer 7 as an example.

[0199] Here, before being fixed to the syringe 3, the static mixer 7 is in a state as shown in Figure 32, where one rotating engagement piece 91 is engaged with one of the second engagement grooves 105B, and the other rotating engagement piece 91' is engaged with the other second engagement groove 105B'. In other words, the width direction Y of the mixer outer casing 23 and the width direction Y of the inner member IM do not coincide.

[0200] When fixing the static mixer 7 to the syringe 3, the user first aligns the opening 23A of the static mixer 7 with one end 41A of the syringe 3. Then, the first projection 46A formed on the syringe 3 faces the first recess 107A formed on the mixer casing 23. Next, the second projection 46B faces the second recess 107B. Furthermore, the third projection 46C faces the third recess 107C.

[0201] In the paste injector 1, only in this state does the first cylindrical portion 45 of the syringe 3 face the first insertion portion 89 of the mixing tip body portion 19. Also, the second cylindrical portion 45' of the syringe 3 faces the second insertion portion 89' of the mixing tip body portion 19. Furthermore, at this time, the regulating protrusion 43a of the syringe 3 faces the regulating recess 108a formed in the mixer casing 23.

[0202] Furthermore, the user can align each of the protrusions 46A, 46B, 46C with each of the recesses 107A, 107B, 107C by aligning the arrow AR1 on the surface of the top wall portion 95 with the first projection 46A along the longitudinal direction X.

[0203] Furthermore, in this embodiment, a second stepped portion 98A and a cylindrical wall portion 98B are formed in the opening 23A of the mixer casing 23. Therefore, the user can use the second stepped portion 98A and the cylindrical wall portion 98B to align the protrusions 46A, 46B, 46C with the recesses 107A, 107B, 107C.

[0204] In other words, the user inserts one end 41A of the syringe 3 into the mixer casing 23 without aligning the engaged portion 46 and the engaging portion 107. At this time, if the projections 46A, 46B, 46C and the recesses 107A, 107B, 107C are not properly facing each other, the circular wall portion 44 of the syringe 3 will come into contact with the second stepped portion 98A and the cylindrical wall portion 98B. As a result, the syringe 3 will not enter the second space K2, but its movement in the direction perpendicular to the longitudinal direction X will be restricted. In other words, when the central axis CA of the mixer casing 23 and the central axis CA of the syringe 3 are aligned, the syringe 3 and the static mixer 7 can rotate relative to each other.

[0205] This allows the user to rotate the mixer casing 23 relative to the syringe 3 around the central axis CA, finding the position where the circular wall portion 44 of the syringe 3 enters the second space K2 (i.e., the position where the first projection 46A and the first recess 107A, the second projection 46B and the second recess 107B, and the third projection 46C and the third recess 107C face each other).

[0206] Furthermore, as shown in Figure 34, when the static mixer 7 is not fixed to the syringe 3, the mixer biasing member 24 is not compressed by the mixer outer casing 23 and the mixer housing 21 and is contained within the space between the mixer outer casing 23 and the mixer housing 21.

[0207] Then, the user brings the syringe 3 and the static mixer 7 relatively closer together along the longitudinal direction X, with each projection 46A, 46B, 46C and each recess 107A, 107B, 107C facing each other.

[0208] As a result, the first projection 46A is inserted into the first vertical groove 107Aa of the first recess 107A and abuts against the stepped portion 98. The second projection 46B is inserted into the second vertical groove 107Ba of the second recess 107B and abuts against the stepped portion 98. The third projection 46C is inserted into the third vertical groove 107Ca of the third recess 107C and abuts against the stepped portion 98.

[0209] Then, the circular wall portion 44 enters the second space K2 of the static mixer 7 and abuts against the stepped portion 98. At the same time, the first cylindrical portion 45 is inserted into the first insertion portion 89, and the second cylindrical portion 45' is inserted into the second insertion portion 89'.

[0210] At this time, the regulating protrusion 43a formed on the syringe 3 fits into the regulating recess 108a.

[0211] Furthermore, when syringe 3 is simply inserted into the static mixer 7, there is play (gap) between syringe 3 and mixer housing 21. Therefore, the mixer biasing member 24 is not compressed.

[0212] Then, after inserting the syringe 3, the user rotates the syringe 3 and the static mixer 7 relative to each other around the central axis CA. At this time, the inner member IM, which is the mixing tip body 19 and the mixer housing 21, does not rotate. In other words, only the outer body OM, which is the mixer outer casing 23, rotates relative to the syringe 3. As a result, the static mixer 7 is in a state where the width direction Y of the mixer outer casing 23 coincides with the width direction Y of the inner member IM, as shown in Figure 33.

[0213] Figure 33 is a bottom view of the static mixer 7 after only the mixer casing 23 has rotated (the inserted syringe 3 is not shown). When only the mixer casing 23 rotates, one rotating engagement piece 91 engages with one of the first engagement grooves 105A, and the other rotating engagement piece 91' engages with the other first engagement groove 105A'.

[0214] Furthermore, the first projection 46A formed on the syringe 3 enters the first transverse groove 107Ab from the end of the first longitudinal groove 107Aa along the stepped portion 98. The first projection 46A is then exposed to the outside through the first window portion 109A. The second projection 46B enters the second transverse groove 107Bb from the end of the second longitudinal groove 107Ba along the stepped portion 98. The second projection 46B is then exposed to the outside through the second window portion 109B. Furthermore, the third projection 46C enters the third transverse groove 107Cb from the end of the third longitudinal groove 107Ca along the stepped portion 98. The third projection 46C is then exposed to the outside through the third window portion 109C.

[0215] As a result, the first projection 46A, the second projection 46B, and the third projection 46C engage with the first recess 107A, the second recess 107B, and the third recess 107C, respectively, and the syringe 3 and the static mixer 7 are fixed to each other.

[0216] Meanwhile, the regulating projection 43a formed on the syringe 3 moves from within the regulating recess 108a toward the remaining portion 108b as the mixer casing 23 rotates. As the regulating projection 43a interferes with the remaining portion 108b, the second peripheral wall portion 99 of the mixer casing 23 is pressed outward. As a result, the second peripheral wall portion 99 deforms, and the regulating projection 43a rides up onto the remaining portion 108b.

[0217] Furthermore, as the mixer casing 23 rotates, the regulating protrusion 43a overcomes the remaining portion 108b and enters the first vertical groove 107Aa of the first recess 107A. As a result, the force pressing the second peripheral wall portion 99 of the mixer casing 23 outward is eliminated, and the second peripheral wall portion 99 returns to its natural state (a state where no pressing force is acting). In other words, when the regulating protrusion 43a and the regulating portion 108 engage, the second peripheral wall portion 99 undergoes elastic deformation. As a result, the paste injector 1 can provide the user with a click sensation. Here, elastic deformation refers to a deformation in which the shape and size of an object change due to pressure, but when the pressure is removed, it completely returns to its original shape.

[0218] Furthermore, when the restricting projection 43a is engaged with the first vertical groove 107Aa, if the syringe 3 and the mixer casing 23 attempt to rotate relative to each other in opposite directions, the restricting projection 43a engaged with the first vertical groove 107Aa interferes with the remaining portion 108b. As a result, the rotation of the mixer casing 23 relative to the syringe 3 in the opposite direction is restricted, and the fixed state of the syringe 3 and the static mixer 7 is maintained. Note that "opposite direction" refers to the direction in which, for example, the first projection 46A engaged with the first horizontal groove 107Ab moves toward the first vertical groove 107Aa. In other words, it means the rotation direction that removes the static mixer 7 from the syringe 3.

[0219] Furthermore, in the first transverse groove 107Ab, the groove width in the longitudinal direction X gradually narrows from the side of the first longitudinal groove 107Aa. Therefore, as the mixer casing 23 rotates, the first projection 46A gradually approaches the stepped portion 98. Similarly, in the second transverse groove 107Bb, the groove width in the longitudinal direction X gradually narrows from the side of the second longitudinal groove 107Ba. Therefore, as the mixer casing 23 rotates, the second projection 46B gradually approaches the stepped portion 98. Moreover, in the third transverse groove 107Cb, the groove width in the longitudinal direction X gradually narrows from the side of the third longitudinal groove 107Ca. Therefore, as the mixer casing 23 rotates, the third projection 46C also gradually approaches the stepped portion 98.

[0220] As a result, the syringe 3 gradually pushes the inner member IM, which consists of the mixing tip body 19 and the mixer housing 21, toward the top wall 95 of the mixer outer casing 23. The mixer outer casing 23 and the mixer housing 21 move closer together. Consequently, the mixer biasing member 24 is gradually compressed and bends between the mixer outer casing 23 and the mixer housing 21.

[0221] In other words, as the syringe 3 rotates relative to the mixer housing 23, the syringe 3 is pushed into the static mixer 7, and the syringe 3 pushes the mixing tip body 19 in. As a result, the mixing tip body 19 and the mixer housing 21 move closer to the mixer housing 23. This causes a force to act on the outer body side projection 24a (outer circumference projection 24a1 and inner circumference projection 24a2) of the mixer biasing member 24 toward the mixer housing 21. Also, a force acts on the inner member side projection 24b (intermediate projection 24b1) that is in contact with the mixer housing 21 toward the mixer housing 23. As a result, the mixer biasing member 24 bends in a convex shape toward the mixer housing 23 with respect to the inner member side projection 24b.

[0222] As shown in Figure 3A, the mixer biasing member 24 is held in a compressed state between the mixer outer casing 23 and the mixer housing 21. As a result, the discharge ports 51, 51' of the syringe 3 and the boundary portions around the first insertion portion 89 and the second insertion portion 89' of the static mixer 7 (mounting member M) are in close contact (in this embodiment, in particular, the boundary portions between the first cylindrical portion 45 and the second cylindrical portion 45' and the flange portion 87C). Therefore, even if the length of the first insertion portion 89 and the second insertion portion 89' that enter into the discharge ports 51, 51' is short, leakage of paste from between the syringe 3 and the static mixer 7 can be prevented.

[0223] If the biasing force of the mixer biasing member 24 is too strong, it becomes difficult to rotate the mixer casing 23 and fix the static mixer 7 and syringe 3 together. On the other hand, if the biasing force of the mixer biasing member 24 is too weak, there is a risk of paste leaking from the boundary. Therefore, the biasing force of the mixer biasing member 24 should be such that it is easy to rotate the mixer casing 23 and prevents paste from leaking from the boundary.

[0224] <Operation of the guide tip, static mixer, and paste injector> The operation of the guide tip, static mixer, and paste injector of the first embodiment will be described below.

[0225] The guide tip 9 of the first embodiment is a guide tip attached to a static mixer 7 which has inlet holes 29A, 29A' and outlet holes 29B, 29B', and multiple paste passages 29, 29' through which multiple types of pastes individually stored in a syringe 3 extending in the longitudinal direction X pass, an intermediate passage 31 that guides the multiple types of pastes coming out of the outlet holes 29B, 29B' to a confluence point JP, and a mixing passage 33 through which the multiple types of pastes that have been combined at the confluence point JP pass while being mixed. The guide tip 9 is attached to the outside of the static mixer 7 and is flexible. The static mixer 7 of the first embodiment includes multiple paste passages 29, 29' through which multiple types of pastes, each individually stored in a syringe 3 extending in the longitudinal direction X, pass, having inlet holes 29A, 29A' and outlet holes 29B, 29B', an intermediate passage 31 that guides the multiple types of pastes exiting from the outlet holes 29B, 29B' to a confluence point JP, a mixing passage 33 through which the multiple types of pastes, which have been combined at the confluence point JP, pass while being mixed, and a guide tip 9 with the above configuration. The paste injector 1 of the first embodiment includes the static mixer 7 with the above configuration.

[0226] The guide tip 9 is attached to the outside of the static mixer 7, making it possible to attach it to existing static mixers 7. Since the guide tip 9 is flexible, the user can bend the guide tip 9 to a desired angle depending on the location and angle of the affected area, such as a root canal or tooth cavity. Therefore, the guide tip 9 of the first embodiment, the static mixer 7 equipped with this guide tip 9, and the paste injector 1 equipped with this static mixer 7 can properly fill areas in the oral cavity where it is difficult to dispense paste due to the angle. Furthermore, there is no need to manufacture a new static mixer 7 in order to attach the guide tip 9. Thus, the manufacturing cost and introduction cost of the static mixer 7 and the paste injector 1 are reduced.

[0227] The guide tip 9 of the first embodiment has flexibility that allows it to be bent into a predetermined shape. With this configuration, the guide tip 9 can be freely and flexibly bent at a desired angle. Therefore, the guide tip 9 and static mixer 7 of the first embodiment can more appropriately fill the mouth with paste even in areas where it is difficult to dispense the paste due to the angle.

[0228] The guide tip 9 of the first embodiment has shape retention properties that allow it to maintain its shape after bending. With this configuration, the guide tip 9 is bent and fixed at a desired angle, making it difficult to return to its original shape during paste dispensing. Therefore, the guide tip 9 and static mixer 7 of the first embodiment offer improved operability for the user and enable more appropriate filling of paste even in areas of the oral cavity where it is difficult to dispense paste due to the angle.

[0229] In the first embodiment, the guide tip 9 has a smooth inner surface through which the paste passes before and after bending. This configuration suppresses the influence of paste fluidity on the guide tip 9 before and after bending, and also facilitates control of the paste discharge amount. Therefore, the guide tip 9 and static mixer 7 of the first embodiment can discharge the paste more smoothly and appropriately.

[0230] In the static mixer 7 to which the guide tip 9 of the first embodiment is attached, a plurality of paste passages 29, 29' are arranged in a circle around the central axis of the syringe 3 and extend in the longitudinal direction X. At least a portion of the distal surface of each of the plurality of paste passages 29, 29' away from the central axis has a tapered portion that approaches the central axis as it moves from the inlet hole 29A to the outlet hole 29B. With this configuration, the static mixer 7 does not form air bubble reservoirs in the paste passages, preventing air bubbles from being mixed into the paste, and the paste flow path is also narrowed. As a result, the user can easily adjust the amount of paste dispensed by the force with which they push the plunger 5. In addition, no air bubbles are mixed into the paste within the guide tip 9. As a result, the guide tip 9 and static mixer 7 of the first embodiment can dispense paste in an appropriate amount.

[0231] The guide tip 9 of the first embodiment comprises a mounting portion 9A that is detachably attached to the outside of the static mixer 7, and a guide portion 9B having a discharge port 9G for dispensing paste, wherein at least a part of the guide portion 9B is bendable. With this configuration, the angle of the guide portion 9B can be freely changed. Therefore, the guide tip 9 and static mixer 7 of the first embodiment can properly fill with paste even in areas in the oral cavity where it is difficult to dispense paste due to the angle. Furthermore, the user can freely choose to use the paste injector 1 with or without the guide tip 9 attached to the static mixer 7. Thus, the paste injector 1 can fill with paste from relatively narrow root canals to relatively large tooth cavities, and the range of application of a single paste injector 1 can be expanded.

[0232] The guide tip 9 of the first embodiment has one or more sets of bendable thin-walled portions 9H and non-bendable thick-walled portions 9I on its outer circumferential surface, and its inner circumferential surface is smooth. With this configuration, the angle of the guide tip 9 can be freely changed by bending the thin-walled portion 9H. Furthermore, because the thick-walled portion 9I does not bend, the guide tip 9 can maintain its shape after bending. In addition, the guide tip 9 can be changed to another angle again.

[0233] (Second Embodiment) <Overall Configuration> The paste injector 1 of the second embodiment has the same overall configuration as the paste injector 1 of the first embodiment shown in Figure 1, etc., except that it is equipped with a guide tip 9' shown in Figures 37 and 38 instead of the guide tip 9. For this reason, components similar to those of the first embodiment are given the same reference numerals as those of the first embodiment, and detailed explanations are omitted. The following will mainly describe the configuration of the guide tip 9' of the second embodiment, which differs from that of the first embodiment.

[0234] Figure 37 is a side view and a cross-sectional view of the guide tip 9' of the second embodiment. Figure 38 is a side view and a cross-sectional view of the guide tip 9' with the guide portion 9B bent. The guide tip 9' of the second embodiment comprises a mounting portion 9A and a guide portion 9B. The mounting portion 9A has the same configuration as the mounting portion 9A of the first embodiment and comprises an insertion hole 9C, a first paste discharge path 9D, and an engaging projection 9E.

[0235] The guide portion 9B is formed from a tubular member that extends diagonally upward from the tip of the mounting portion 9A in a direction intersecting the direction in which the mounting portion 9A extends. The guide portion 9B includes a second paste discharge path 9F and a discharge port 9G.

[0236] In the first embodiment, the guide portion 9B includes a bendable portion 9J composed of multiple sets of thin-walled portions 9H and thick-walled portions 9I, and a part of the guide portion 9B is bendable. In contrast, the guide portion 9B in the second embodiment does not have thin-walled portions 9H and thick-walled portions 9I, and its outer and inner circumferential surfaces are smooth along its entire length. In the second embodiment, the entire guide portion 9B is a bendable portion 9J.

[0237] The guide tip 9' of the second embodiment is formed using a resin, preferably a thermoplastic resin, that has the property of softening when heated and solidifying when cooled. The guide tip 9' of the second embodiment is entirely formed using a thermoplastic resin and is bendable when heated. The guide tip 9' has a guide portion 9B that forms a bendable portion 9J that bends when heated, but since the entire thing is made of thermoplastic resin, the mounting portion 9A can also bend when heated and become a bendable portion 9J. The guide tip 9' is not limited to a configuration in which the entire thing is made using a thermoplastic resin; the guide portion 9B may be made using a thermoplastic resin and the mounting portion 9A may be made of a resin such as polypropylene or a metal.

[0238] The resin used in the guide tip 9' preferably has a glass transition temperature of 20°C to 70°C, more preferably 25°C to 60°C, even more preferably 30°C to 50°C, and particularly preferably 35°C to 45°C. By setting the glass transition temperature within the above range, the guide tip 9' can be softened by immersing it in warm water at 20°C to 70°C while ensuring that the guide tip 9' does not get wet, by heating it with a heater or thermostat at 20°C to 70°C, or by applying warm air at 20°C to 70°C, allowing the user to easily bend the guide portion 9B to the desired angle. Furthermore, the guide portion 9B maintains its shape after bending as the resin solidifies upon cooling.

[0239] Furthermore, the temperature range of the glass transition region of the resin used in the guide tip 9' is preferably 70°C or less, more preferably 60°C or less, even more preferably 50°C or less, and particularly preferably 45°C or less. With this configuration, the guide tip 9' exhibits a larger range of changes in physical properties due to temperature changes, making it easier to soften and solidify. Moreover, the difference between the elastic modulus of the glass state and the storage modulus of the rubber state of the resin used in the guide tip 9' is preferably 101 Pa or more, more preferably 102 Pa or more, and even more preferably 103 Pa or more. With this configuration, the guide tip 9' is said to be able to achieve both flexibility when heated and retention when cooled.

[0240] Furthermore, the softening point of the resin used in the static mixer 7 is preferably higher than the glass transition temperature of the resin used in the guide tip 9', more preferably 10°C or more higher, even more preferably 20°C or more higher, and particularly preferably 30°C or more higher. With this configuration, even if the guide tip 9' is heated while it is attached to the static mixer 7, the static mixer 7 will not be affected by the heating. Note that not all components of the static mixer 7 need to be made of resin with the above properties. At least the element housing portion 37 to which the guide tip 9' is attached and the mixing tip body portion 19 need to be made of resin with the above properties.

[0241] The resin used for the guide tip 9' can be preferably polyurethane resin, silicone resin, polynorbornene resin, trans polyisoprene resin, styrene-butadiene copolymer, polyester resin, high-density polyethylene resin, etc., with polyurethane resin being the most preferred among these.

[0242] [Attachment and Bending of Guide Tip] The guide tip 9' of the second embodiment is attached to the static mixer 7 in the same manner as the guide tip 9 of the first embodiment. The guide tip 9' may be attached before or after bending. When bending the guide portion 9B, the user heats the guide portion 9B by immersing it in hot water, blowing hot air on it, or warming it with their hands. With the resin of the guide portion 9B softened by this heating, the user applies a bending force to the guide portion 9B, which is the bending portion 9J, with their hands or the like, causing the guide portion 9B to deform and bend, as shown in Figure 38. This allows the guide portion 9B to be set to a desired angle, as shown in Figure 38. When the guide portion 9B is cooled by immersing it in cold water, blowing cold air on it, or leaving it for a predetermined time, the resin solidifies and the bent state of the guide portion 9B is maintained.

[0243] <Operation of the Guide Tip, Static Mixer, and Paste Injector> The guide tip 9', static mixer 7, and paste injector 1 of the second embodiment can achieve the same effects as those of the first embodiment. That is, since the guide tip 9' can be bent at a desired angle, the guide tip 9', static mixer 7, and paste injector 1 can properly fill the paste even in areas of the oral cavity where it is difficult to dispense the paste due to the angle. Since the guide tip 9' can also be attached to the existing static mixer 7, the manufacturing cost and introduction cost of the static mixer 7 and paste injector 1 are reduced.

[0244] Furthermore, the guide tip 9' of the second embodiment is made of a resin with a glass transition temperature of 20°C to 70°C. With this configuration, the guide tip 9' softens easily when heated at a relatively low temperature, allowing the user to freely and easily bend the guide tip 9' at a desired angle. In addition, the resin solidifies upon cooling, maintaining the bent state. Furthermore, the guide tip 9' can be bent at other angles by reheating, enabling flexible use according to the type of site of use in the oral cavity, the angle of use, and the purpose of use.

[0245] Furthermore, the softening point of the resin constituting the static mixer 7 in the second embodiment is 10°C or more higher than the glass transition temperature of the resin constituting the guide tip 9'. With this configuration, even if the guide tip 9' is heated after being attached to the static mixer 7, the static mixer 7 is suppressed to the effects of heat, and the guide tip 9' is properly bent.

[0246] Although embodiments of the present invention have been specifically described above, the present invention is not limited to these embodiments, and modifications are, of course, possible within the scope of the technical idea of ​​the present invention.

[0247] For example, the guide tip 9 of the first embodiment may have a configuration having multiple sets of thin-walled portions 9H and thick-walled portions 9I, and may also be formed using the same resin as the guide tip 9' of the second embodiment. With this configuration, the guide tip 9 can be bent more easily by softening through heating, which allows the thin-walled portions 9H to deform more readily. Furthermore, the bent state of the guide tip 9 is more appropriately maintained by the solidification of the resin through cooling, and excessive bending is prevented by the thick-walled portions 9I. In addition, the guide tip 9 can function not only as a bendable portion, but also as a bendable portion of the entire guide section 9B, and even the entire guide tip 9.

[0248] In addition to the above description of embodiments, the following is further disclosed: (1) A guide tip to be attached to a static mixer having an inlet hole and an outlet hole, and comprising a plurality of paste passages through which a plurality of types of pastes individually stored in a syringe extending in the longitudinal direction pass, an intermediate passage that guides the plurality of types of pastes that have come out of the outlet hole to a confluence point, and a mixing passage through which the plurality of types of pastes that have been combined at the confluence point pass while being mixed, wherein the guide tip is mounted on the outside of the static mixer and is bendable. (2) The guide tip described in (1) above, wherein the guide tip is characterized by having flexibility that allows it to be bent into a predetermined shape. (3) The guide tip described in (1) or (2) above, wherein the guide tip is characterized by having shape retention that allows it to maintain its shape after bending. (4) The guide tip described in any of (1) to (3) above, wherein the inner surface through which the paste passes is smooth before and after bending. (5) A guide tip according to any one of (1) to (4) above, wherein the static mixer to which the guide tip is attached is characterized in that the plurality of paste passages are arranged in a circle on the circumference of the central axis of the syringe and extend in the longitudinal direction, and the inner surface of each of the plurality of paste passages has a tapered portion formed in a tapered shape that approaches the central axis as it moves from the inlet hole to the outlet hole, at least a part of the distal surface away from the central axis. (6) A guide tip according to any one of (1) to (5) above, wherein the guide tip comprises a mounting portion that is detachably attached to the outside of the static mixer, and a guide portion having an outlet for discharging the paste, wherein at least a part of the guide portion is bendable.(7) A guide tip as described in any of (1) to (6) above, characterized in that the guide tip has one or more sets of a bendable thin-walled portion and a non-bendable thick-walled portion arranged in a continuous manner on its outer circumferential surface, and the inner circumferential surface is smooth. (8) A guide tip as described in any of (1) to (7) above, characterized in that the guide tip is made of a resin having a glass transition temperature of 20°C or more and 70°C or less. (9) A guide tip as described in (8) above, characterized in that the softening point of the resin constituting the static mixer is 10°C or more higher than the glass transition temperature of the resin constituting the guide tip. (10) A static mixer characterized by comprising: a plurality of paste passages having inlet and outlet holes, through which a plurality of pastes, each individually stored in a syringe extending in the longitudinal direction, pass; an intermediate passage that guides the plurality of pastes coming out of the outlet hole to a confluence point; a mixing passage through which the plurality of pastes, which have been combined at the confluence point, pass while being mixed; and a guide tip as described in any of (1) to (9) above. Cross-reference of related applications

[0249] This application claims priority based on Japanese Patent Application No. 2024-229031, filed with the Japan Patent Office on 25 December 2024, all of which disclosures are incorporated herein by reference in their entirety.

Claims

1. A guide tip to be attached to a static mixer having an inlet hole and an outlet hole, and comprising: multiple paste passages through which multiple types of pastes, each individually stored in a syringe extending in the longitudinal direction, pass; an intermediate passage that guides the multiple types of pastes exiting the outlet hole to a confluence point; and a mixing passage through which the multiple types of pastes, which have been combined at the confluence point, pass while being mixed, wherein the guide tip is mounted on the outside of the static mixer and is bendable.

2. The guide tip according to claim 1, characterized in that the guide tip has flexibility that allows it to be bent into a predetermined shape.

3. A guide tip according to claim 1, characterized in that the guide tip has shape retention properties that allow it to maintain its shape after bending.

4. The guide tip according to claim 1, characterized in that the inner circumferential surface through which the paste passes before and after bending is smooth.

5. The guide tip according to claim 1, wherein the static mixer to which the guide tip is attached is characterized in that the plurality of paste passages are arranged in a circle on a circumference with respect to the central axis of the syringe and extend in the longitudinal direction, and the inner surface of each of the plurality of paste passages has a tapered portion formed in a tapered shape that approaches the central axis as it moves from the inlet hole to the outlet hole, at least a portion of the distal surface away from the central axis.

6. The guide tip according to claim 1, wherein the guide tip comprises a mounting portion that is detachably attached to the outside of the static mixer, and a guide portion having a discharge port for dispensing the paste, wherein at least a part of the guide portion is bendable.

7. The guide tip according to claim 1, wherein the guide tip is characterized in that one or more sets of a bendable thin-walled portion and a non-bendable thick-walled portion are continuously provided on the outer circumferential surface, and the inner circumferential surface is smooth.

8. A guide tip according to claim 1, characterized in that the guide tip is made of a resin having a glass transition temperature of 20°C or more and 70°C or less.

9. A guide tip according to claim 8, characterized in that the softening point of the resin constituting the static mixer is 10°C or more higher than the glass transition temperature of the resin constituting the guide tip.

10. A static mixer comprising: a plurality of paste passages through which a plurality of types of pastes, each individually housed in a syringe extending in the longitudinal direction and having an inlet and outlet hole; an intermediate passage that guides the plurality of types of pastes exiting from the outlet hole to a confluence point; a mixing passage through which the plurality of types of pastes, which have been combined at the confluence point, pass while being mixed; and a guide tip according to any one of claims 1 to 9.

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