Syringe and paste injector

Abstract

To provide a syringe capable of individually storing a plurality of pastes, easily held by a user, and easily performing labeling by an automatic labeling machine.SOLUTION: Provided is a syringe 3 that includes a syringe body in which are formed a plurality of paste storage chambers 49, 49' to be filled with paste, and that extends in a longitudinal direction X, wherein the plurality of paste storage chambers 49, 49' are arranged along a width direction Y, and an outer peripheral surface of the syringe body 41 includes: a pair of width-direction outer peripheral surfaces 57, 57 disposed on opposite sides in a thickness direction Z perpendicular to the longitudinal direction X and the width direction Y; and a pair of thickness-direction outer peripheral surfaces 59, 59 disposed on opposite sides in the width direction Y; and a connecting outer circumferential surface 61 set between the widthwise outer circumferential surface 57 and the thicknesswise outer circumferential surface 59; the widthwise outer peripheral surface 57 having a flat portion 57A which is flat along the longitudinal direction X and the widthwise direction Y, and the connecting outer peripheral surface 61 being curved at a predetermined radius of curvature.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] There is known a dental material that is made of multiple types of pastes and is mixed together immediately before use. In order to inject such a dental material into a predetermined position, there is a paste injector that mixes and discharges multiple types of pastes.

[0003] The paste injector includes syringes each containing a different type of paste, a plunger for pushing out the paste, and a static mixer attached to the discharge portion of the syringe.

[0004] An example of a syringe is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special publication 2008-504956 Summary of the Invention [Problem to be solved by the invention]

[0006] A user of the paste injector must hold the syringe in one hand and push the plunger into the syringe to gradually dispense an appropriate amount of dental material from the syringe. An automatic labeling machine attaches a label to the periphery of the syringe, which contains information about the ingredients of the paste contained in the syringe, the expiration date, and other information.

[0007] However, the syringe described in Patent Document 1 is formed by connecting multiple cylindrical bodies, and the circumferential surface of each cylindrical body is curved all around. Therefore, when a user holds the syringe with one hand, the contact area between the fingertip and the syringe is small, which makes it slippery and difficult to hold. On the other hand, when the cylindrical body is a rectangular parallelepiped, the outer circumferential surface of the syringe is flat, so the contact area between the fingertip and the syringe can be increased, but the label is bent at the corners on the outer circumferential surface. This causes a problem that labeling using an automatic labeling machine is difficult.

[0008] An object of the present invention is to provide a syringe and a paste injector that can store a plurality of pastes individually, is easy for a user to hold, and facilitates labeling by an automatic labeling machine. [Means for solving the problem]

[0009] The syringe of the present invention is a syringe extending in a longitudinal direction, comprising a syringe body having a plurality of paste storage chambers formed therein in which paste is filled, the plurality of paste storage chambers being aligned along a width direction perpendicular to the longitudinal direction, and the outer peripheral surface of the syringe body has a pair of width direction outer peripheral surfaces arranged on opposite sides along a thickness direction perpendicular to the longitudinal direction and the width direction, a pair of thickness direction outer peripheral surfaces arranged on opposite sides along the width direction, and a connecting outer peripheral surface set between the width direction outer peripheral surfaces and the thickness direction outer peripheral surfaces. In order to achieve the above object, the width direction outer peripheral surfaces have flat portions that are flat along the longitudinal direction and the width direction, and the connecting outer peripheral surfaces are curved with a predetermined curvature.

[0010] The paste injector of the present invention comprises the above-mentioned syringe and a plunger that is inserted into the paste storage chamber of the syringe to push out the paste. Effect of the Invention

[0011] By configuring in this manner, the syringe and paste injector of the present invention can store a plurality of pastes individually, making them easy for a user to hold and facilitating labeling by an automatic labeling machine. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a paste injector equipped with a static mixer according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the paste injector of the first embodiment. [Diagram 3] 1 is a cross-sectional view of a static mixer fixed to the tip of a syringe of Example 1, cut in the width direction at a position passing through a central axis extending in the longitudinal direction. FIG. [Figure 4A] FIG. 2 is a front view of the syringe of the first embodiment. [Figure 4B] FIG. 2 is a side view of the syringe of Example 1. [Figure 4C] FIG. 2 is a plan view of the syringe of the first embodiment. [Figure 4D] FIG. 2 is a bottom view of the syringe of Example 1. [Diagram 5] 4D is a cross-sectional view taken along line VV shown in FIG. 4C. [Figure 6] 4B is an end view taken along line VI-VI shown in FIG. 4A. [Figure 7A] FIG. 2 is a front view of the plunger body of the first embodiment. [Figure 7B] FIG. 2 is a side view of the plunger body of the first embodiment. [Figure 7C] FIG. 2 is a plan view of the plunger body of the first embodiment. [Figure 7D] FIG. 4 is a bottom view of the plunger body of the first embodiment. [Figure 8] 7A , which is a cross-sectional view taken along the line VIII-VIII. [Figure 9A] FIG. 2 is a perspective view of an elastic body holder according to the first embodiment. [Figure 9B] FIG. 4 is a bottom view of the elastic body holder of the first embodiment. [Figure 10]2 is a cross-sectional view of the elastic holder in the paste injector of Example 1 with an O-ring attached to the annular groove, cut in the width direction perpendicular to the longitudinal direction at the neck portion. FIG. [Figure 11] FIG. 1 is a cross-sectional view (schematic diagram) of the paste injector of Example 1, in which an elastic holder with an O-ring attached to the annular groove is inserted into the paste storage chamber of a syringe, cut in the width direction perpendicular to the longitudinal direction at the neck portion, and a cross-sectional view (schematic diagram) as viewed from the front and side. [Figure 12A] FIG. 2 is a perspective view of a mixing tip body of the first embodiment. [Figure 12B] FIG. 2 is a bottom view of the mixing tip body of the first embodiment. [Figure 13] 13 is a cross-sectional view taken along line XIII-XIII shown in FIG. 12B. [Figure 14A] FIG. 2 is a perspective view of a mixer housing according to the first embodiment. [Figure 14B] FIG. 2 is a bottom view of the mixer housing of the first embodiment. [Figure 15] 14C is a cross-sectional view taken along line XV-XV shown in FIG. 14B. [Figure 16A] FIG. 2 is a front view of the mixer exterior body of the first embodiment. [Figure 16B] FIG. 2 is a plan view of the mixer exterior body of the first embodiment. [Figure 16C] FIG. 2 is a bottom view of the mixer exterior body of the first embodiment. [Figure 17] 17 is a cross-sectional view taken along line XVII-XVII shown in FIG. 16B. [Figure 18] 18 is a cross-sectional view taken along line XVIII-XVIII shown in FIG. 16A. [Figure 19A] FIG. 2 is a perspective view of a cap inner member of the first embodiment. [Figure 19B] FIG. 2 is a bottom view of the cap inner member of the first embodiment. [Figure 20] 19C is a cross-sectional view taken along the line XX-XX shown in FIG. 19B. [Figure 21A] FIG. 2 is a front view of the cap exterior body of the first embodiment. [Figure 21B]1 is a plan view of a cap exterior body according to a first embodiment. FIG. [Figure 21C] FIG. 2 is a bottom view of the cap exterior body of the first embodiment. [Figure 22] 22 is a cross-sectional view taken along line XXII-XXII of FIG. 21B. [Figure 23] 23 is a cross-sectional view taken along line XXIII-XXIII shown in FIG. 21A. [Figure 24] FIG. 2 is a diagram showing the state of the paste injector of Example 1 before the static mixer is placed over the syringe and fixed in place. [Diagram 25] FIG. 2 is a bottom view of the static mixer in the paste injector of Example 1 after only the mixer exterior body has rotated. [Figure 26] FIG. 11 is an exploded perspective view of the paste injector of the second embodiment. [Figure 27] FIG. 11 is a cross-sectional view of the static mixer fixed to the tip of the syringe of Example 2, cut in the width direction at a position passing through the central axis extending in the longitudinal direction. [Figure 28A] FIG. 11 is a perspective view of the tip of the syringe of Example 2. [Figure 28B] FIG. 11 is a plan view of the syringe of Example 2. [Figure 28C] This is a main part of a cross-sectional view taken along line XXVIII-XXVIII shown in Figure 28B. [Figure 29A] FIG. 11 is a perspective view of a mixing tip body of Example 2. [Figure 29B] FIG. 11 is a bottom view of the mixing tip body of the second embodiment. [Figure 29C] 29C is a cross-sectional view taken along line XXIX-XXIX shown in FIG. 29B. [Figure 30A] FIG. 11 is a perspective view of a mixer housing according to a second embodiment. [Figure 30B] 30B is a cross-sectional view taken along the line XXX-XXX shown in FIG. 30A. [Figure 31A] FIG. 11 is a front view of the mixer exterior body of the second embodiment. [Figure 31B] FIG. 11 is a side view of a mixer exterior body of the second embodiment. [Figure 31C] FIG. 11 is a plan view of a mixer exterior body of a second embodiment. [Figure 31D] FIG. 11 is a bottom view of the mixer exterior body of the second embodiment. [Figure 31E] This is a cross-sectional view taken along line XXXIE-XXXIE shown in Figure 31C. [Fig. 31F] 31D is a cross-sectional view taken along the line XXXIF-XXXIF shown in FIG. 31C. [Figure 31G] 31B is a cross-sectional view taken along the line XXXIG-XXXIG shown in FIG. 31A. [Figure 32A] FIG. 11 is a front view of a cap exterior body according to a second embodiment. [Figure 32B] FIG. 11 is a side view of a cap exterior body of the second embodiment. [Figure 32C] FIG. 11 is a plan view of a cap exterior body of a second embodiment. [Fig. 32D] FIG. 11 is a bottom view of the mixer exterior body of the second embodiment. [Figure 32E] This is a cross-sectional view taken along line XXXIIE-XXXIIE shown in Figure 32C. [Fig. 32F] FIG. 32D is a cross-sectional view taken along the line XXXIIF-XXXIIF shown in FIG. 32C. [Fig. 32G] 32B is a cross-sectional view taken along line XXXIIG-XXXIIG shown in FIG. 32A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the syringe and paste injector of the present invention will be described based on Example 1 and Example 2 shown in the drawings.

[0014] Example 1 <Overall composition> Fig. 1 is a perspective view of a paste injector 1 equipped with a static mixer 7 of Example 1, and Fig. 2 is an exploded perspective view of the paste injector 1 of Example 1. In this Example 1, as shown in Fig. 2, a longitudinal direction (X), a width direction (Y), and a thickness direction (Z) are defined for the paste injector 1.

[0015] As shown in FIG. 1, the paste injector 1 includes a syringe 3, a plunger 5, a static mixer 7, and a guide tip 9. The paste injector 1 of the first embodiment pushes out two types of pastes individually filled in the syringe 3 with the plunger 5, mixes them with the static mixer 7 just before use to prepare a dental material, and injects the paste into a desired location (such as an affected area or a dental cap) through the guide tip 9. The guide tip 9 is a nozzle member that is attached to the static mixer 7 in a fixed fit state as necessary. The paste injector 1 can be used even if the guide tip 9 is not attached to the static mixer 7.

[0016] When the paste injector 1 is stored or transported, a cap 11 shown in FIG. 2 is fixed to the tip of the syringe 3 (one end 41A of the syringe body 41 described later) instead of the static mixer 7. In this specification, the static mixer 7 and the cap 11 detachably attached to the tip of the syringe 3 (one end 41A of the syringe body 41) are collectively referred to as an attachment member M. The syringe 3, plunger 5, and attachment member M (static mixer 7 or cap 11) extend in the longitudinal direction X shown in FIG. 2 and are assembled in a state where the central axis CA passing through the center of each member is aligned.

[0017] The syringe 3 is filled with paste in advance and distributed with the plunger 5 inserted therein. The plunger 5 is composed of a plunger body 13, an elastic body holder 15 loosely engaged with the tip of the plunger body 13, and an annular O-ring (elastic body) 17 attached to the elastic body holder 15. Here, "loosely engaged" means that the elastic body holder 15 is engaged with the plunger body 13 by an engagement force that causes the elastic body holder 15 to come off from the plunger body 13 due to the frictional force between the syringe 3 and the O-ring 17. The elastic body holder 15 and the O-ring 17 form the tip of the plunger 5. It is needless to say that the plunger 5 may be an integrated one that is not separated into the plunger body 13 and the elastic body holder 15. In this case, the annular O-ring 17 may be directly attached to the tip of the plunger 5.

[0018] The static mixer 7 is composed of a mixing tip main body 19, a mixer housing 21, and a mixer exterior body 23.

[0019] The cap 11 is composed of a cap inner member 25 and a cap exterior body 27.

[0020] [Paste flow path] FIG. 3 is a cross-sectional view of the static mixer 7 fixed to the tip of the syringe 3, taken in the width direction Y at a position passing through a central axis CA extending in the longitudinal direction X.

[0021] In the static mixer 7, a paste flow path is formed by the mixing tip main body 19 and the mixer housing 21. In the first embodiment, the paste flow path is composed of a paste passage 29, a paste passage 29', an intermediate passage 31, and a mixing passage 33. The paste passages 29, 29' are arranged circumferentially about the central axis CA, are arranged symmetrically along the width direction Y, and each extends in the longitudinal direction X. The mixing passage 33 is located downstream of the paste passages 29, 29' in the paste flow direction, and extends about the central axis CA extending in the longitudinal direction X. The intermediate passage 31 is a passage that connects the paste passages 29, 29' and the mixing passage 33.

[0022] The paste passage 29 is a passage through which the paste discharged from the paste storage chamber 49 of the syringe 3 flows. The paste passage 29 has an inflow hole 29A through which the paste flows in and an outflow hole 29B through which the paste flows out, and is formed in the mixing tip body 19. Here, the opening area of ​​the inflow hole 29A is larger than the opening area of ​​the outflow hole 29B. Furthermore, the opening center point of the outflow hole 29B is set at a position closer to the central axis CA than the opening center point of the inflow hole 29A.

[0023] The inner circumferential surface of the paste passage 29 has a tapered portion on a distal surface 29C away from the central axis CA when viewed in a cross section perpendicular to the thickness direction Z. The tapered portion of the distal surface 29C of the first embodiment is formed in a tapered shape that gradually approaches the central axis CA from the inlet hole 29A to the outlet hole 29B. That is, the tapered portion of the first embodiment extends at a constant angle from the inlet hole 29A to the outlet hole 29B. The inner circumferential surface of the paste passage 29 has a proximal surface 29D close to the central axis CA when viewed in a cross section perpendicular to the thickness direction Z, which extends parallel to the central axis CA from the inlet hole 29A to the outlet hole 29B, and is aligned with the central axis CA. For this reason, the area of ​​the cross section perpendicular to the central axis CA (longitudinal direction X) of the paste passage 29 of the first embodiment gradually decreases at a constant rate from the inlet hole 29A to the outlet hole 29B.

[0024] The paste passage 29' is a passage through which the paste discharged from the paste storage chamber 49' of the syringe 3 flows. Since the paste passage 29' has a similar configuration to the paste passage 29, the reference numerals of the respective parts of the paste passage 29 are followed by "", and the description thereof will be omitted.

[0025] The paste passage 29 and the paste passage 29' are formed to have the same size and are symmetrical in the width direction Y with respect to the central axis CA. That is, the inlet hole 29A and the inlet hole 29A' are set to have the same opening area, and the outlet hole 29B and the outlet hole 29B' are set to have the same opening area. In addition, the distance from the central axis CA to the center of the inlet hole 29A when viewed along the central axis CA is the same as the distance from the central axis CA to the inlet hole 29A'. In addition, the distance from the central axis CA to the center of the outlet hole 29B when viewed along the central axis CA is the same as the distance from the central axis CA to the outlet hole 29B'. In addition, the inclination angle of the distal surface 29C with respect to the central axis CA is the same as the inclination angle of the distal surface 29C' with respect to the central axis CA.

[0026] The intermediate passage 31 is a passage that guides the paste flowing out from the outflow holes 29B, 29B' to the joining position JP. In the first embodiment, a backflow prevention wall 35 is provided between the outflow holes 29B and 29B'. The backflow prevention wall 35 divides the intermediate passage 31 into the outflow hole 29B side and the outflow hole 29B' side, and prevents the paste flowing out from one of the outflow holes 29B (29B') from flowing into the other outflow hole 29B' (29B). Here, the backflow prevention wall 35 stands up from the end face of the mixing tip main body 19 where the outflow holes 29B, 29B' are formed, and extends to the joining position JP along the central axis CA. The backflow prevention wall 35 has curved surfaces 35A, 35A' formed at the base portion to direct the paste to the joining position JP.

[0027] The mixing passage 33 is a passage through which the pastes that join at the joining position JP pass while being mixed, and extends about a central axis CA that extends in the longitudinal direction X. The mixing passage 33 is composed of an element housing portion 37 that extends cylindrically in the mixer housing 21, and an element group 39 that extends from the end of the backflow prevention wall 35 and is inserted into the element housing portion 37.

[0028] [Fixing mounting parts] The static mixer 7 or the cap 11, which is the mounting member M, is detachably mounted to the tip end (one end 41A of the syringe body 41) of the syringe 3. The fixing structure will be described below.

[0029] Here, the mounting member M is composed of an inner member IM and an exterior body OM. When the mounting member M is a static mixer 7, the mixing tip main body 19 and the mixer housing 21 form the inner member IM, and the mixer exterior body 23 forms the exterior body OM. When the mounting member M is a cap 11, the cap inner member 25 forms the inner member IM, and the cap exterior body 27 forms the exterior body OM.

[0030] In the static mixer 7, the mixing tip main body 19 and the mixer housing 21 (inner member IM) are disposed inside the mixer exterior body 23 (exterior body OM). The mixing tip main body 19 and the mixer housing 21 are configured to be rotatable around the central axis CA within a predetermined angle range relative to the mixer exterior body 23. Similarly, in the cap 11, the cap inner member 25 (inner member IM) is disposed inside the cap exterior body 27 (exterior body OM). The cap inner member 25 is configured to be rotatable around the central axis CA within a predetermined angle range relative to the cap exterior body 27.

[0031] Then, when the tip portion of the syringe 3 (one end portion 41A of the syringe body 41) is inserted into the exterior body OM via the inner member IM along the central axis CA, the inner member IM becomes unable to rotate relative to the syringe 3, but the exterior body OM is rotatable relative to the syringe 3. When the exterior body OM rotates around the central axis CA in this state, only the exterior body OM rotates relative to the syringe 3, and the mounting member M is fixed to the tip portion of the syringe 3 (one end portion 41A of the syringe body 41) via the engagement structure.

[0032] The engagement structure has three or more pairs (three pairs in the first embodiment) of engagement pairs each consisting of an engagement portion 45 formed on the syringe 3 and an engaged portion 107 formed on the mixer exterior body 23 which is the exterior body OM, or an engagement portion 45 formed on the syringe 3 and an engaged portion 129 formed on the cap exterior body 27 which is the exterior body OM. The detailed configurations of the engagement portion 45, the engaged portion 107, and the engaged portion 129 will be described later.

[0033] <Details of each component> [Syringe] Fig. 4A is a front view of the syringe 3, Fig. 4B is a side view, Fig. 4C is a plan view, and Fig. 4D is a bottom view. In addition, Fig. 5 is a cross-sectional view taken along line VV shown in Fig. 4C, and Fig. 6 is an end view taken along line VI-VI shown in Fig. 4A.

[0034] The syringe 3 is a cylindrical body extending in the longitudinal direction X, and includes a syringe body 41, two protrusions 43, 43', an engagement portion 45, and a finger hook portion 47.

[0035] The syringe body 41 has a plurality of (two in this example) paste storage chambers 49 and a paste storage chamber 49' formed therein, which are filled with paste. The two paste storage chambers 49, 49' are lined up along the width direction Y inside the syringe body 41 and formed to have the same shape. One end 41A of the syringe body 41 has a circular wall portion 41a that has a circular shape when cut in the width direction Y perpendicular to the longitudinal direction X, and the other end 41B has a finger hook portion 47 formed thereon.

[0036] The two protrusions 43, 43' are cylindrical parts that protrude in the longitudinal direction X from an end face of one end 41A (circular wall part 41a) of the syringe body 41 and have respective tips that become discharge outlets 51, 51'. The inner periphery of the protrusion 43 constitutes a part of the paste storage chamber 49, and the inner periphery of the protrusion 43' constitutes a part of the paste storage chamber 49'. The two protrusions 43, 43' are connected via an upright wall 41c that stands up from the circular wall part 41a, and the inclination is regulated.

[0037] The engaging portion 45 constitutes an engaging structure for fixing the mounting member M to the tip portion (one end portion 41A of the syringe body 41) of the syringe 3, and is a portion that engages with the engaged portion (engaged portion 107 and engaged portion 129) of the mounting member M (the static mixer 7 and the cap 11). In the first embodiment, the engaging portion 45 is composed of three protruding pieces 45A, 45B, and 45C formed on the outer circumferential surface of the circular wall portion 41a of the syringe body 41, as shown in FIG. 4C.

[0038] The protrusions 45A, 45B, and 45C are aligned in the rotation direction of the exterior body OM, and are asymmetrical about the central axis CA, which is the center of rotation of the exterior body OM, when viewed along the central axis CA. Note that "point symmetry" generally means that a figure overlaps with the original figure when rotated 180° about the symmetrical point, but "asymmetrical" here means that the protrusions 45A, 45B, and 45C do not overlap with each other when the syringe 3 rotates about the central axis CA, except when rotated 360°.

[0039] In the first embodiment, the protrusions 45A, 45B, and 45C are arranged at unequal intervals along the rotational direction of the exterior body OM. Here, the distance in the rotational direction from the protrusion 45A to the protrusion 45B is the same as the distance in the rotational direction from the protrusion 45A to the protrusion 45C. On the other hand, the distance in the rotational direction from the protrusion 45B to the protrusion 45C is shorter than the distance from the protrusion 45A to the protrusion 45B and the distance from the protrusion 45A to the protrusion 45C.

[0040] Furthermore, the protrusions 45A, 45B, and 45C have different shapes when viewed along the central axis CA. That is, the length of the protrusion 45A in the rotational direction is longer than the lengths of the protrusions 45B and 45C in the rotational direction. On the other hand, the lengths of the protrusions 45B and 45C in the rotational direction are the same, but the directions in which they protrude from the outer circumferential surface of the circular wall portion 41a are different.

[0041] The protrusions 45B and 45C are symmetrical with respect to an axis of symmetry AS that passes through the central axis CA and the circumferential center position of the protrusion 45A. An arrow AR1 indicating the position of the protrusion 45A is engraved on the surface of the circular wall portion 41a.

[0042] The finger hook 47 is a flange-shaped portion extending in the width direction Y and thickness direction Z from the outer peripheral surface of the other end 41B of the syringe body 41. As shown in Figs. 4C and 4D, the finger hook 47 of the first embodiment has an approximately hexagonal outer peripheral shape. Note that the finger hook 47 may be textured on at least a surface 47a on the side of one end 41A. By textured surface 47a, it is possible to prevent fingers from slipping during use and to make gate marks less noticeable, thereby improving the quality of the appearance.

[0043] As shown in FIG. 6, the outer circumferential surface of the syringe body 41 has a pair of widthwise outer circumferential surfaces 57, 57', a pair of thicknesswise outer circumferential surfaces 59, 59', and four connecting outer circumferential surfaces 61.

[0044] The pair of widthwise outer peripheral surfaces 57, 57' are surfaces of the outer peripheral surface of the syringe body 41 that are located on opposite sides along the thickness direction Z. The widthwise outer peripheral surfaces 57, 57' each have a flat portion 57A that is flat along the longitudinal direction X and the width direction Y. In addition, the widthwise outer peripheral surfaces 57, 57' each have a groove-shaped recessed portion 57B that extends in the longitudinal direction X and is recessed further than the flat portion 57A. The recessed portion 57B is located between two paste storage chambers 49, 49' formed inside the syringe body 41, and the flat portion 57A is divided into two by the recessed portion 57B along the width direction Y. In addition, the recessed portion 57B has a wedge-shaped cross section in which the length in the width direction Y gradually narrows as it becomes deeper.

[0045] The pair of thickness direction outer peripheral surfaces 59, 59' are surfaces of the outer peripheral surface of the syringe body 41 that are located opposite each other along the width direction Y. The thickness direction outer peripheral surfaces 59, 59' are curved outward in the width direction Y with a predetermined radius of curvature, which is set to a curved surface of R5 in this example.

[0046] The connecting outer peripheral surface 61 is a surface set between the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, between the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59, between the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59', and between the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59', among the outer peripheral surfaces of the syringe body 41. The connecting outer peripheral surface 61 is curved with a predetermined curvature radius (for example, curvature radius R1 to R5, R1.5 in Example 1), and smoothly connects the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59', and the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59', respectively. In Example 1, the connecting outer peripheral surface 61 and the pair of thickness direction outer peripheral surfaces 59, 59' are formed by combining multiple curved surfaces set to different curvature radii. The connecting outer circumferential surface 61 and the pair of thickness direction outer circumferential surfaces 59, 59' may be formed by curved surfaces set to the same radius of curvature.

[0047] The paste storage chamber 49 has a discharge port 51 at one end 49A (projection 43) that opens one end of the paste storage chamber 49 and discharges the paste pushed out by the plunger 5, and a filling port 53 at the other end 49B that opens the other end of the paste storage chamber 49. The paste storage chamber 49 has a tapered shape at one end 49A into which the tip end (top 83 of the elastic holder 15) of the plunger 5 inserted into the paste storage chamber 49 fits. In addition, a stopper protrusion 55 is provided on the inner peripheral surface of the other end 49B to prevent the plunger 5 inserted into the paste storage chamber 49 from falling out. Since the paste storage chamber 49' has the same configuration as the paste storage chamber 49, the same reference numerals as those of the paste storage chamber 49 are used and the description is omitted.

[0048] As shown in Fig. 6, the cross-sectional shape of the paste storage chamber 49 cut in a direction perpendicular to the longitudinal direction X is an ellipse shape in which the long axis direction LA is along the thickness direction Z and the short axis direction SA is along the width direction Y. The term "ellipse shape" refers to an ellipse defined by geometry, as well as a shape that is similar to an ellipse, such as an oval (a shape in which two semicircles are connected by two straight lines), an elliptical arch shape (a shape in which a part of an ellipse is cut out along a straight line), a flat ellipse (a shape in which an ellipse is crushed in the long axis or short axis direction), an oval shape, etc. In the first embodiment, the inner peripheral surface of the paste storage chamber 49 is composed of a pair of inner flat surface portions 63, 63' that are flat along the longitudinal direction X and the thickness direction Z, and a pair of inner curved surface portions 65, 65' that are curved at a predetermined curvature.

[0049] The pair of inner flat surface portions 63, 63' face each other in the width direction Y, sandwiching the internal space of the paste storage chamber 49 therebetween. The pair of inner curved surface portions 65, 65' face each other in the thickness direction Z, sandwiching the internal space of the paste storage chamber 49 therebetween, and smoothly connect the pair of inner flat surface portions 63, 63'. As a result, in Example 1, the cross-sectional shape of the inner circumferential surface of the paste storage chamber 49 presents a flattened ellipse.

[0050] In Example 1, the length dimension T1 in the long axis direction LA of the elliptical shape of the inner peripheral surface of the paste storage chamber 49 is preferably within a range of 1.1 to 2.0, where the length dimension W1 in the short axis direction SA is 1. In Example 1, the length dimension T1 in the long axis direction LA is set to 1.3, where the length dimension W1 in the short axis direction SA is 1. Specifically, the length dimension T1 in the long axis direction LA is preferably 5 mm to 20 mm, and the length dimension W1 in the short axis direction SA is preferably 4.5 mm to 10 mm.

[0051] [Plunger body] Fig. 7A is a front view of the plunger body 13, Fig. 7B is a side view, Fig. 7C is a plan view, and Fig. 7D is a bottom view. Also, Fig. 8 is a cross-sectional view taken along line VIII-VIII shown in Fig. 7A.

[0052] The plunger body 13 includes a pressing portion 67 and two rod-shaped portions 69 and 69'.

[0053] The pressing portion 67 is a portion that is pressed by a finger (e.g., thumb) when a user holds the syringe 3 between two fingers (e.g., index finger and middle finger) and places the fingers on the finger hook portion 47 to push the plunger 5 into the syringe 3. As shown in FIG. 7D, the pressing portion 67 has an outer circumferential shape that is elliptical and long in the width direction Y, and two rod-shaped portions 69, 69' are disposed in the center. The bottom surface of the pressing portion 67 is curved in the direction in which the rod-shaped portions 69, 69' extend so that the user can easily press the pressing portion 67 with their fingers.

[0054] The rod-shaped portions 69, 69' are rod-shaped portions extending in parallel from the pressing portion 67 along the longitudinal direction X. In the first embodiment, the rod-shaped portions 69, 69' are arranged at a predetermined interval along the long axis direction (width direction Y) of the pressing portion 67, and are inserted simultaneously into the paste storage chambers 49, 49', respectively. Here, the rod-shaped portions 69 and 69' have the same shape, and both can be inserted into both the paste storage chambers 49, 49'. In other words, when the rod-shaped portion 69 is inserted into the paste storage chamber 49, the rod-shaped portion 69' is inserted into the paste storage chamber 49', and when the rod-shaped portion 69 is inserted into the paste storage chamber 49', the rod-shaped portion 69' is inserted into the paste storage chamber 49.

[0055] 8, the cross-sectional shape of the rod-shaped portion 69 in the width direction Y is formed in a cross shape composed of a combination of a thickness direction wall portion 71A extending in the thickness direction Z and a width direction wall portion 71B extending in the width direction Y. The length dimension in the thickness direction Z of the thickness direction wall portion 71A is larger than the length dimension in the width direction Y of the width direction wall portion 71B. When the rod-shaped portion 69 is inserted into the paste storage chamber 49 (49'), the tip of the thickness direction wall portion 71A is aligned along the inner curved surface portions 65, 65' of the paste storage chamber 49 (49'), and the tip of the width direction wall portion 71B is aligned along the inner flat surface portions 63, 63' of the paste storage chamber 49 (49').

[0056] At one end of the width direction wall 71B in the longitudinal direction X, a pair of protrusions 73, 73 formed to protrude in the width direction Y and a pair of hollowed-out portions 75, 75 are formed. As a result, when the rod-shaped portion 69 is inserted into the paste storage chamber 49 (49'), the pair of protrusions 73, 73 of the width direction wall 71B contact the inner flat surface portion 63, 63', and the portion where the pair of hollowed-out portions 75, 75 are formed is bent. As a result, the rod-shaped portion 69 is positioned in the width direction Y, and rattling is prevented. Similarly, a plurality of protrusions 77 are formed on the thickness direction wall 71A and the width direction wall 71B in order to prevent rattling of the rod-shaped portion 69.

[0057] The rod-shaped portion 69 has a holder engagement portion 79 formed at its tip with which the elastic holder 15 is loosely engaged. The holder engagement portion 79 has a tip wall portion 79A that contacts the bottom surface 81A of the elastic holder 15, and an engagement protrusion 79B that extends from the tip wall portion 79A in the longitudinal direction X and is inserted into an engagement hole 81B formed in the bottom surface 81A of the elastic holder 15. As shown in FIG. 7C, the tip wall portion 79A has an outer peripheral shape that is an ellipse shape that follows the cross-sectional shape of the paste storage chamber 49 (49'). When the rod-shaped portion 69 is inserted into the paste storage chamber 49 (49'), if the protrusions 73, 73 and the protrusion 77 pass over the removal prevention protrusion 55 (55'), the removal prevention protrusion 55 (55') gets caught on the protrusion 73, etc., to prevent the plunger 5 from falling off.

[0058] Since the rod-shaped portion 69' has the same configuration as the rod-shaped portion 69, the reference numerals of the respective parts of the rod-shaped portion 69 are followed by "", and the description thereof will be omitted.

[0059] [Elastic holder] FIG. 9A is a perspective view of the elastic body holder 15, and FIG. 9B is a bottom view.

[0060] The elastic holder 15 is loosely engaged with the holder engaging parts 79, 79' at the tip of the plunger main body 13, one by one, and constitutes the tip of the plunger 5. The elastic holder 15 has a body 81, a top 83, and a neck 85. The body 81 is a part whose cross section in the width direction Y is elliptical. The bottom surface 81A of the body 81 is formed with an engaged hole 81B into which the engaging protrusion 79B of the holder engaging part 79 or the engaging protrusion 79B' of the holder engaging part 79' is inserted. The outer peripheral surface 81C of the body 81 has an elliptical shape that follows the elliptical shape of the inner peripheral surface (inner flat surface parts 63, 63' and inner curved surface parts 65, 65') of the paste storage chamber 49 (49'). The top part 83 has a shape that becomes narrower toward the tip. The neck part 85 is an elliptical part formed between the body 81 and the top part 83. The neck portion 85, and the body portion 81 and the top portion 83 that face each other across the neck portion 85, form an annular groove portion 81D in which the O-ring 17 is attached.

[0061] The elliptical shape of the body 81 is smaller than the cross-sectional shape of the paste storage chamber 49 (49'), and is similar to the cross-sectional shape of the paste storage chamber 49 (49'), and follows the elliptical shape of the inner peripheral surface of the paste storage chamber 49 (49'). Therefore, when the elastic holder 15 is inserted into the paste storage chamber 49 (49'), the distance from the outer peripheral surface 81C of the body 81 to the inner peripheral surface of the paste storage chamber 49 (49') is constant over the entire circumference of the body 81. In addition, in the first embodiment, similar to the paste storage chamber 49 (49'), the length dimension T2 in the major axis direction of the elliptical shape of the body 81 is preferably within a range of 1.1 to 2.0, assuming that the length dimension W2 in the minor axis direction is 1. Specifically, in the first embodiment, the length dimension T2 in the major axis direction is set to 1.3, assuming that the length dimension W2 in the minor axis direction is 1.

[0062] The elliptical shape of the neck portion 85 is smaller than that of the body portion 81, and has a cross-sectional shape similar to that of the body portion 81. In other words, the elliptical shape of the neck portion 85 has a cross-sectional shape similar to that of the paste storage chamber 49 (49'). Therefore, when the elastic body holder 15 is inserted into the paste storage chamber 49 (49'), the distance from the outer peripheral surface 85C of the neck portion 85 to the inner peripheral surface of the paste storage chamber 49 (49') is constant over the entire circumference of the neck portion 85. In addition, in the first embodiment, the ratio of the length dimension in the major axis direction to the length dimension in the minor axis direction of the elliptical shape of the neck portion 85 is set to the same ratio as that of the elliptical shape of the body portion 81.

[0063] FIG. 10 is a cross-sectional view of the elastic holder 15 with the O-ring 17 attached to the annular groove 81D, cut in the width direction Y perpendicular to the longitudinal direction X at the neck portion 85. Here, the O-ring 17 is annular, but the neck portion 85 has an elliptical shape. Therefore, when the O-ring 17 is attached to the annular groove 81D, it is stretched in the major axis direction (thickness direction Z) and becomes elliptical. The length dimension T3 of the O-ring 17 in the major axis direction is larger than the length dimension T2 of the elliptical shape of the body portion 81 in the major axis direction. In addition, the length dimension W3 of the O-ring 17 in the minor axis direction is larger than the length dimension W2 of the elliptical shape of the body portion 81 in the minor axis direction. Therefore, the O-ring 17 is fixed in a state where it protrudes from the annular groove 81D.

[0064] Furthermore, a stronger tensile force acts on the region a of the O-ring 17 that is stretched in the long axis direction (thickness direction Z) than on the region b that is not stretched in the long axis direction (thickness direction Z). As a result, as shown in FIG. 10, the wire diameter ΔA of the O-ring 17 in the region a is thinner than the wire diameter ΔB in the region b, and the wire diameter of the O-ring 17 varies depending on the circumferential position. Note that the "wire diameter of the O-ring 17" refers to the cross-sectional thickness of the O-ring 17. Since the wire diameter of the O-ring 17 varies depending on the circumferential position, the amount of protrusion of the O-ring 17 from the annular groove portion 81D varies, and the thinner the wire diameter (e.g., region a), the less the protrusion from the annular groove portion 81D.

[0065] Furthermore, the length dimension T3 in the major axis direction of the elliptical O-ring 17 is slightly larger than the length dimension T1 in the major axis direction of the elliptical shape of the inner peripheral surface of the paste storage chamber 49 or the paste storage chamber 49'. Furthermore, the length dimension W3 in the minor axis direction of the elliptical O-ring 17 is slightly larger than the length dimension W1 in the minor axis direction of the elliptical shape of the inner peripheral surface of the paste storage chamber 49 or the paste storage chamber 49'. Therefore, when the elastic body holder 15 is inserted into the paste storage chamber 49 (49') of the syringe 3, the O-ring 17 comes into contact with the inner peripheral surface of the paste storage chamber 49 (49') and is compressed by being sandwiched between the inner peripheral surface of the paste storage chamber 49 (49') and the outer peripheral surface 85C of the neck portion 85.

[0066] 11 shows a cross-sectional view (schematic view) of the elastic holder 15 with the O-ring 17 attached to the annular groove 81D, cut in the width direction Y perpendicular to the longitudinal direction X at the neck portion 85, and a cross-sectional view (schematic view) of the elastic holder 15 as viewed from the front and side in a state where the elastic holder 15 is inserted into the paste storage chamber 49 of the syringe 3. In FIG. 11, the part of the O-ring 17 that protrudes from the annular groove 81D and is compressed by being inserted into the paste storage chamber 49 is shown in gray, and the state of the O-ring 17 before being compressed is shown by a dashed line.

[0067] 11, when the plunger 5 is inserted into the syringe 3 with the O-ring 17 attached to the annular groove portion 81D, the O-ring 17 is sandwiched and compressed between the inner peripheral surface (the inner flat surface portions 63, 63' and the inner curved surface portions 65, 65') of the paste storage chamber 49 and the outer peripheral surface 85C of the neck portion 85. Here, the wire diameter of the O-ring 17 varies depending on the circumferential position, and the thinner the wire diameter, the less the protrusion from the annular groove portion 81D.

[0068] 11, the difference (ΔX1, ΔX2) between the distance Gd from the outer peripheral surface 85C of the neck portion 85 to the inner peripheral surface of the paste storage chamber 49 and the wire diameter Wr of the O-ring 17 varies depending on the circumferential position of the O-ring 17. Therefore, the compression rate of the O-ring 17 when inserted into the paste storage chamber 49 varies depending on the circumferential position.

[0069] That is, in the elliptical O-ring 17, the region b with a thick wire diameter protrudes more from the annular groove portion 81D than the region a with a thin wire diameter, and the difference ΔX2 in the region b is larger than the difference ΔX1 in the region a. Therefore, when the O-ring 17 is inserted into the syringe 3, the region b of the O-ring 17 is pressed more toward the inside of the paste storage chamber 49 than the region a, and the compression ratio in the region b is larger than the compression ratio in the region a. As a result, the compression ratio in the major axis direction (thickness direction Z) of the elliptical O-ring 17 is larger than the compression ratio in the minor axis direction (width direction Y) of the O-ring 17.

[0070] Since the compression rate of the O-ring 17 varies depending on the circumferential position, the frictional force generated between the O-ring 17 and the inner peripheral surface of the paste storage chamber 49 (49') varies depending on the circumferential position of the O-ring 17. That is, the frictional force between the apex 17A in the major axis direction of the O-ring 17 stretched into an elliptical shape and the inner peripheral surface of the paste storage chamber 49 (49') is greater than the frictional force between the apex 17B in the minor axis direction of the O-ring 17 stretched into an elliptical shape and the inner peripheral surface of the paste storage chamber 49 (49'). Therefore, by adjusting the major axis direction dimension of the elliptical shape that is the cross-sectional shape of the paste storage chamber 49 (49') and the elliptical shape that is the cross-sectional shape of the plunger 5 relative to the minor axis direction dimension, it is easy to adjust the ease of movement of the plunger 5 in the longitudinal direction while maintaining the sealing performance between the inner peripheral surface of the paste storage chamber 49 (49') and the elastic body (O-ring 17).

[0071] It is also preferable that the compression ratio of the O-ring 17 in the long axis direction (compression ratio in region b) is about 10 to 14%, and the compression ratio in the short axis direction (compression ratio in region a) is about 3 to 7%. Specifically, in Example 1, the compression ratio in the long axis direction is 12%, and the compression ratio in the short axis direction is 5%. The compression ratio C (%) is calculated by the following formula: C = (Wr-Gd) / Wr x 100 however, Wr: Wire diameter of elastic body (O-ring) [mm] Gd: Distance from the outer periphery of the neck to the inner periphery of the paste storage chamber [mm]

[0072] The elastic holder 15 is loosely engaged with the holder engagement portion 79 (79') at the tip of the plunger body 13. Therefore, when the elastic holder 15 is inserted into the paste storage chamber 49 (49') of the syringe 3 together with the plunger body 13 with the O-ring 17 attached, the plunger body 13 is pushed in, and the elastic holder 15 moves in the longitudinal direction X together with the plunger body 13 in the paste storage chamber 49 (49'). On the other hand, when the plunger body 13 is pulled back, the elastic holder 15 is separated from the plunger body 13 and is left behind in the paste storage chamber 49 (49'). This prevents air from being drawn into the paste storage chamber 49 (49') from the outlet 51, (51') even if the plunger 5 is pulled back by mistake.

[0073] [Static Mixer] (Mixing tip body) Fig. 12A is a perspective view of the mixing chip main body 19, and Fig. 12B is a bottom view thereof, and Fig. 13 is a cross-sectional view taken along line XIII-XIII shown in Fig. 12B.

[0074] The mixing tip body 19 is a member that, in combination with the mixer housing 21, constitutes the inner member IM of the static mixer 7, which is the mounting member M. The mixing tip body 19 includes a base 87, two insertion portions 89, 89', a pair of rotational engagement pieces 91, 91', a backflow prevention wall 35, and an element group 39.

[0075] The base 87 is a cylindrical portion that fits inside the mixer exterior body 23, which is the exterior body OM. A flange portion 87C extending radially outward is formed on the outer periphery of the base 87. The mixing tip main body 19 is fixed to the mixer exterior body 23 in a relatively rotatable state about the central axis CA by fitting the flange portion 87C into a groove (circumferential groove 103) formed on the inner periphery of the mixer exterior body 23, which will be described later.

[0076] The two insertion portions 89, 89' and the pair of rotary engagement pieces 91, 91' are formed on a first end surface 87A of the base 87 facing the syringe 3, and extend from the first end surface 87A in the longitudinal direction X. When the static mixer 7 is attached to the syringe 3, the two insertion portions 89, 89' are inserted into the two protrusions 43, 43' of the syringe 3, respectively. A paste passage 29 is formed inside the insertion portion 89, and a paste passage 29' is formed inside the insertion portion 89'. The pair of rotary engagement pieces 91, 91' are portions that respectively engage with engagement grooves (a pair of first engagement grooves 105A, 105A' or a pair of second engagement grooves 105B, 105B') of the mixer exterior body 23 described below.

[0077] The backflow prevention wall 35 extends along the central axis CA from the center of the second end face 87B opposite to the first end face 87A of the base 87. The tip of the backflow prevention wall 35 is the joining position JP of the paste, and 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 Example 1) lined up along the central axis CA.

[0078] The paste passage 29 is formed to continuously penetrate the insertion portion 89 and the base portion 87. The inflow hole 29A is formed in the end face of the insertion portion 89, and the outflow hole 29B is formed in the second end face 87B of the base portion 87. Similarly, the paste passage 29' is formed to continuously penetrate the insertion portion 89' and the base portion 87. The inflow hole 29A' is formed in the end face of the insertion portion 89', and the outflow hole 29B' is formed in the second end face 87B of the base portion 87.

[0079] (Mixer housing) Fig. 14A is a perspective view of the mixer housing 21, and Fig. 14B is a bottom view thereof, and Fig. 15 is a cross-sectional view taken along line XV-XV shown in Fig. 14B.

[0080] The mixer housing 21 is a member that, in combination with the mixing tip main body 19, constitutes the inner member IM of the static mixer 7, which is the mounting member M. The mixer housing 21 includes a base housing portion 93 and an element housing portion 37.

[0081] The base housing portion 93 includes a circular end wall portion 93A that covers the second end face 87B of the base 87 of the mixing tip main body portion 19 when the mixer housing 21 is placed over the mixing tip main body portion 19, and a peripheral wall portion 93B that rises from the edge of the end wall portion 93A, surrounds the base 87, and extends until its tip contacts the flange portion 87C.

[0082] A recess 93C is provided on the inner wall of the end wall portion 93A at a position opposite the outlet holes 29B, 29B'. By covering the mixing tip body 19 with the mixer housing 21, an intermediate passage 31 is formed inside the inner member IM, which is partitioned by the base 87, the backflow prevention wall 35, and the recess 93C (see FIG. 3).

[0083] The element housing portion 37 is a cylindrical portion with an open tip, extending in the longitudinal direction X from a through hole formed in the center of the end wall portion 93A of the base housing portion 93. When the mixer housing 21 is placed over the mixing tip body 19, the element housing portion 37 has an element group 39 inserted therein to form a mixing passage 33. A guide tip engagement groove 37A for fixing the guide tip 9 is formed on the outer periphery of the element housing portion 37.

[0084] (Mixer exterior body) Fig. 16A is a front view of mixer exterior body 23, Fig. 16B is a plan view, and Fig. 16C is a bottom view. In addition, Fig. 17 is a cross-sectional view taken along line XVII-XVII shown in Fig. 16B, and Fig. 18 is a cross-sectional view taken along line XVIII-XVIII shown in Fig. 16A.

[0085] The mixer exterior body 23 is a cylindrical member that constitutes the exterior body OM of the static mixer 7, which is the mounting member M. The static mixer 7, which is the mounting member M, is constituted by storing an inner member IM consisting of a mixing tip main body 19 and a mixer housing 21 inside the mixer exterior body 23. In addition, the mixer exterior body 23 rotates relatively to the syringe 3 about a central axis CA.

[0086] The mixer exterior body 23 includes a top wall portion 95 having a regular hexagonal outer peripheral shape, a first peripheral wall portion 97 rising from the edge of the top wall portion 95, and a second peripheral wall portion 99 extending continuously from the first peripheral wall portion 97 via a step. Inside the mixer exterior body 23, a first space S1 surrounded by the top wall portion 95 and the first peripheral wall portion 97 and a second space S2 surrounded by the second peripheral wall portion 99 are formed (see FIG. 17). An inner member IM consisting of a mixing tip main body portion 19 and a mixer housing 21 is fitted in the first space S1 in a state in which it can rotate around a central axis CA. In addition, the tip portion of the syringe 3 (one end portion 41A of the syringe main body 41) is inserted into the second space S2 with the inner member IM housed therein (see FIG. 3).

[0087] The top wall 95 is a portion that covers the end wall 93A of the mixer housing 21, and faces the opening into which the syringe 3 is inserted (see FIG. 3). A top penetration tube 101 for exposing the element housing portion 37 to the outside is formed in the center of the top wall 95. The top penetration tube 101 is a cylindrical portion that protrudes from the top wall 95 and penetrates the top wall 95. When the inner member IM consisting of the mixing tip main body 19 and the mixer housing 21 is stored in the mixer exterior body 23, the element housing portion 37 penetrates the top penetration tube 101. In addition, an arrow AR2 indicating the position of a dent 107A described later is engraved on the surface of the top wall 95 (see FIG. 16B).

[0088] When viewed along the central axis CA, the outer peripheral surface of the first peripheral wall portion 97 is a regular hexagon as shown in Fig. 16B. When viewed along the central axis CA, the inner peripheral surface of the first peripheral wall portion 97 is a circle as shown in Fig. 16C. The inner peripheral surface of the first peripheral wall portion 97 is formed with a circumferential groove 103, a pair of first engaged grooves 105A, 105A', and a pair of second engaged grooves 105B, 105B'.

[0089] As shown in FIG. 3, the circumferential groove 103 is a recess into which the flange portion 87C of the mixing tip body 19 fits, and extends in the circumferential direction (the rotation direction of the inner member IM).

[0090] The first engaged groove 105A and the second engaged groove 105B on one side are recesses with which one of the rotary engaging pieces 91 engages. The first engaged groove 105A' and the second engaged groove 105B' on the other side are recesses with which the other of the rotary engaging pieces 91' engages. The pair of first engaged grooves 105A, 105A' and the pair of second engaged grooves 105B, 105B' are arranged side by side in the circumferential direction (the rotation direction of the inner member IM) with a predetermined interval therebetween. Here, the pair of first engaged grooves 105A, 105A' are formed at positions facing each other in the thickness direction Z across the central axis CA. The pair of second engaged grooves 105B, 105B' are formed at positions facing each other in a direction shifted in the circumferential direction from the thickness direction Z across the central axis CA.

[0091] When assembled into the static mixer 7, the mixing tip body 19 and the mixer housing 21 rotate relative to the mixer exterior body 23 around the central axis CA. At this time, depending on the positional relationship in the rotational direction between the mixing tip body 19 and the mixer housing 21 and the mixer exterior body 23, one rotating engagement piece 91 engages with either the first engaged groove 105A or the second engaged groove 105B on one side, and the other rotating engagement piece 91' engages with either the first engaged groove 105A' or the second engaged groove 105B' on the other side. This determines the relative rotational position of the mixing tip body 19 and the mixer housing 21 and the mixer exterior body 23.

[0092] The second peripheral wall portion 99 has an outer peripheral surface that is hexagonal as shown in FIG. 16B when viewed along the central axis CA. The outer peripheral surface of the second peripheral wall portion 99 has a pair of long side portions 99A, 99A located on opposite sides to each other along the thickness direction Z. The pair of long side portions 99A, 99A are shaped to bulge radially outward so that the circular wall portion 41a of the syringe 3 can be inserted (see FIG. 16B, FIG. 16C, etc.). The inner peripheral surface of the second peripheral wall portion 99 has a circular shape as shown in FIG. 16C when viewed along the central axis CA.

[0093] The inner circumferential surface of the second circumferential wall portion 99 is formed with a stepped portion 98 and an engaged portion 107 composed of three recesses 107A, 107B, and 107C. The stepped portion 98 is formed at the boundary between the first circumferential wall portion 97 and the second circumferential wall portion 99, and is a stepped unevenness that narrows the inner diameter of the mixer outer casing 23 toward the top wall portion 95, and extends in the circumferential direction (the rotation direction of the inner member IM). When the static mixer 7 is attached to the tip of the syringe 3, the circular wall portion 41a of the syringe 3 abuts against the stepped portion 98 (see FIG. 3).

[0094] In addition, the engaged portion 107 constitutes an engagement structure that fixes the mounting member M to the tip portion of the syringe 3 (one end portion 41A of the syringe body 41), and is the portion that engages with the engagement portion 45 (three protrusion pieces 45A, 45B, 45C) of the syringe 3.

[0095] The recesses 107A, 107B, and 107C have first grooves 107Aa, 107Ba, and 107Ca, and second grooves 107Ab, 107Bb, and 107Cb, respectively. The first grooves 107Aa, 107Ba, and 107Ca open to an end face 99B of the second circumferential wall 99 (an opening of the mixer exterior body 23 into which the syringe 3 is inserted) and extend along the longitudinal direction X (center axis CA) to the step portion 98. The second grooves 107Ab, 107Bb, and 107Cb extend from the ends of the first grooves 107Aa, 107Ba, and 107Ca along the step portion 98 in the rotational direction of the mixer exterior body 23. Furthermore, windows 109A, 109B, and 109C are formed at positions corresponding to the second grooves 107Ab, 107Bb, and 107Cb, respectively, penetrating the second circumferential wall portion 99. That is, the second grooves 107Ab, 107Bb, and 107Cb are defined by the edges of the windows 109A, 109B, and 109C.

[0096] The recesses 107A, 107B, and 107C are arranged along the rotation direction of the mixer exterior body 23, and are asymmetrical about the central axis CA, which is the center of rotation of the mixer exterior body 23, when viewed along the central axis CA. In the first embodiment, the recesses 107A, 107B, and 107C are arranged at unequal intervals along the rotation direction of the mixer exterior body 23. That is, the recess 107A is formed at a position on the inner circumferential surface of the second peripheral wall portion 99 that corresponds to a corner portion of the outer circumferential surface of the second peripheral wall portion 99. The recesses 107B and 107C are formed at a position on the inner circumferential surface of the second peripheral wall portion 99 that corresponds to a flat portion of the outer circumferential surface of the second peripheral wall portion 99 (see FIG. 16C and FIG. 18). Further, recess 107A has a shape into which protrusion 45A serving as engaging portion 45 can be inserted, recess 107B has a shape into which protrusion 45B serving as engaging portion 45 can be inserted, and recess 107C has a shape into which protrusion 45C serving as engaging portion 45 can be inserted. Recesses 107A, 107B, and 107C have different shapes when viewed along central axis CA.

[0097] [cap] The cap 11 is fixed to the tip of the syringe 3 (one end 41A of the syringe body 41) in place of the static mixer 7 during storage or transportation of the paste injector 1. The same component names are used for components common to the static mixer 7, and descriptions thereof may be omitted.

[0098] (Inner cap component) Fig. 19A is a perspective view of the cap inner member 25, and Fig. 19B is a bottom view thereof, and Fig. 20 is a cross-sectional view taken along the line XX-XX shown in Fig. 19B.

[0099] The cap inner member 25 is a member that constitutes the inner member IM of the cap 11 that is the mounting member M, and is a member that corresponds to the mixing tip main body 19 and the mixer housing 21 that are the inner member IM of the static mixer 7.

[0100] The cap inner member 25, like the mixing tip body 19, includes a base portion 111, two insertion portions 113, 113', and a pair of rotational engagement pieces 115, 115'.

[0101] The base 111 is a cylindrical portion that fits inside the cap exterior body 27, which is the exterior body OM. A flange portion 117C extending radially outward is formed on the outer periphery of the base 111. The cap inner member 25 is fixed to the cap exterior body 27 in a relatively rotatable state about the central axis CA by fitting the flange portion 117C into a groove (circumferential groove 125) formed on the inner periphery of the cap exterior body 27, which will be described later.

[0102] The two insertion parts 113, 113' and the pair of rotation engagement pieces 115, 115' are formed on a first end surface 111A of the base 111 facing the syringe 3, and extend from the first end surface 111A in the longitudinal direction X. When the cap 11 is attached to the syringe 3, the two insertion parts 113, 113' are inserted into the two protrusions 43, 43' of the syringe 3, respectively. Unlike the case of the mixing tip main body 19, the insertion parts 113, 113' have a columnar shape for sealing the outlets 51, 51' of the syringe 3, and no passage is formed inside. The pair of rotation engagement pieces 115, 115' are parts that respectively engage with the engagement grooves (a pair of first engagement grooves 127A, 127A' or a pair of second engagement grooves 127B, 127B') of the cap exterior body 27 described later.

[0103] A pair of bottomed recesses 117, 117 are formed on a second end surface 111B of the base 111 opposite to the first end surface 111A.

[0104] (Cap exterior body) Fig. 21A is a front view of cap exterior body 27, Fig. 21B is a plan view, and Fig. 21C is a bottom view. Also, Fig. 22 is a cross-sectional view taken along line XXII-XXII shown in Fig. 21B, and Fig. 23 is a cross-sectional view taken along line XXIII-XXIII shown in Fig. 21A.

[0105] The cap exterior body 27 is a cylindrical member constituting the exterior body OM of the cap 11 which is the mounting member M, and is a member corresponding to the mixer exterior body 23 which is the exterior body OM of the static mixer 7. The cap inner member 25 is stored inside the cap exterior body 27 to form the cap 11 which is the mounting member M. In addition, the cap exterior body 27 rotates relatively to the syringe 3 about the central axis CA.

[0106] The cap exterior body 27 includes a top wall portion 119 having a regular hexagonal outer peripheral shape, a first peripheral wall portion 121 rising from an edge of the top wall portion 119, and a second peripheral wall portion 123 extending continuously from the first peripheral wall portion 121 via a step. Inside the cap exterior body 27, a first space S1 surrounded by the top wall portion 119 and the first peripheral wall portion 121, and a second space S2 surrounded by the second peripheral wall portion 123 are formed (see FIG. 22). An inner member IM made of the cap inner member 25 is fitted into the first space S1 in a state in which it can rotate around the central axis CA. In addition, a tip portion (one end portion 41A of the syringe body 41) a of the syringe 3 is inserted into the second space S2 with the inner member IM housed therein.

[0107] The top wall 119 is a portion that closes the first space S1. Unlike the mixing tip body 19, the top wall 119 is made of a curved plate member, and does not have a top through-cylinder formed in the center. In addition, an arrow AR2 indicating the position of a dent 129A (described later) is engraved on the surface of the top wall 119 (see FIG. 21B).

[0108] When viewed along the central axis CA, the outer peripheral surface of the first peripheral wall portion 121 has a regular hexagonal shape as shown in Fig. 21B. When viewed along the central axis CA, the inner peripheral surface of the first peripheral wall portion 121 has a circular shape as shown in Fig. 21C. The inner peripheral surface of the first peripheral wall portion 121 is formed with a circumferential groove 125, a pair of first engaged grooves 127A, 127A', and a pair of second engaged grooves 127B, 127B'.

[0109] The circumferential groove 125 is a recess into which the flange portion 117C of the cap inner member 25 fits, and extends in the circumferential direction (the rotation direction of the cap inner member 25).

[0110] The first engaged groove 127A and the second engaged groove 127B on one side are recesses with which one of the rotary engaging pieces 115 engages. The first engaged groove 127A' and the second engaged groove 127B' on the other side are recesses with which the other of the rotary engaging pieces 115' engages. The pair of first engaged grooves 127A, 127A' and the pair of second engaged grooves 127B, 127B' are arranged side by side in the circumferential direction (the rotation direction of the cap inner member 25) with a predetermined interval therebetween. Here, the pair of first engaged grooves 127A, 127A' are formed at positions facing each other in the thickness direction Z across the central axis CA. The pair of second engaged grooves 127B, 127B' are formed at positions facing each other in a direction shifted in the circumferential direction from the thickness direction Z across the central axis CA.

[0111] When assembled into the cap 11, the cap inner member 25 rotates relative to the cap exterior body 27 around the central axis CA. At this time, depending on the positional relationship in the rotational direction between the cap inner member 25 and the cap exterior body 27, one rotational engagement piece 115 engages with either the first engaged groove 127A or the second engaged groove 127B on one side, and the other rotational engagement piece 115' engages with either the first engaged groove 127A' or the second engaged groove 127B' on the other side. This determines the relative positions in the rotational direction between the cap inner member 25 and the cap exterior body 27.

[0112] The second peripheral wall portion 123 has an outer peripheral surface that is hexagonal as shown in FIG. 21B when viewed along the central axis CA. The outer peripheral surface of the second peripheral wall portion 123 has a pair of long side portions 123A, 123A that are located on opposite sides to each other along the thickness direction Z. The pair of long side portions 123A, 123A are bulged outward in the radial direction so that the circular wall portion 41a of the syringe 3 can be inserted (see FIG. 21B, FIG. 21C, etc.). The inner peripheral surface of the second peripheral wall portion 123 has a circular shape as shown in FIG. 21C when viewed along the central axis CA.

[0113] Then, a step portion 120 and an engaged portion 129 composed of three recesses 129A, 129B, and 129C are formed on the inner peripheral surface of second peripheral wall portion 123. Step portion 120 is formed at the boundary between first peripheral wall portion 121 and second peripheral wall portion 123, and is a stepped unevenness that narrows the inner diameter of cap exterior body 27 toward top wall portion 119, and extends in the circumferential direction (the rotation direction of inner member IM). When cap 11 is attached to the tip of syringe 3, circular wall portion 41a of syringe 3 abuts against step portion 120.

[0114] In addition, the engaged portion 129 constitutes an engagement structure that fixes the mounting member M to the tip portion of the syringe 3 (one end portion 41A of the syringe body 41), and is the portion that engages with the engagement portion 45 (three protrusion pieces 45A, 45B, 45C) of the syringe 3.

[0115] The recesses 129A, 129B, and 129C have first grooves 129Aa, 129Ba, and 129Ca, and second grooves 129Ab, 129Bb, and 129Cb, respectively. The first grooves 129Aa, 129Ba, and 129Ca open to an end face of the second circumferential wall portion 123 (an opening of the cap exterior body 27 into which the syringe 3 is inserted) and extend along the longitudinal direction X (the central axis CA) to the step portion 120. The second grooves 129Ab, 129Bb, and 129Cb extend from the ends of the first grooves 129Aa, 129Ba, and 129Ca along the step portion 120 in the rotational direction of the cap exterior body 27. Then, windows 131A, 131B, 131C penetrating the second circumferential wall portion 123 are formed at positions corresponding to the second groove portions 129Ab, 129Bb, 129Cb, respectively. That is, the second groove portions 129Ab, 129Bb, 129Cb are formed by edges of the windows 131A, 131B, 131C.

[0116] The dents 129A, 129B, and 129C are aligned along the rotational direction of the cap exterior body 27, and are asymmetrical about the central axis CA, which is the center of rotation of the cap exterior body 27, when viewed along the central axis CA. In the first embodiment, the dents 129A, 129B, and 129C are aligned at unequal intervals along the rotational direction of the cap exterior body 27. That is, the dent 129A is formed at a position on the inner circumferential surface of the second circumferential wall portion 123 that corresponds to a corner portion of the outer circumferential surface of the second circumferential wall portion 123. The dents 129B and 129C are formed at positions on the inner circumferential surface of the second circumferential wall portion 123 that correspond to flat portions of the outer circumferential surface of the second circumferential wall portion 123 (see FIG. 21C and FIG. 23). Further, recess 129A has a shape into which protrusion 45A serving as engagement portion 45 can be inserted, recess 129B has a shape into which protrusion 45B serving as engagement portion 45 can be inserted, and recess 129C has a shape into which protrusion 45C serving as engagement portion 45 can be inserted. Recesses 129A, 129B, and 129C have different shapes from one another when viewed along central axis CA.

[0117] [Details on how to secure the mounting parts] 24 and 25, the details of the process of fixing the mounting member M to the syringe 3 will be described using the static mixer 7 as an example. Fig. 24 is a diagram showing the state prior to the stage where the static mixer 7 is placed over and fixed to the syringe 3. In Fig. 24, the bottom surface of the static mixer 7 is shown, and the syringe 3 is shown in plan view with the finger hook 47 omitted. In Figs. 24 and 25, the inner member IM is shown colored gray.

[0118] 24, before being fixed to the syringe 3, the static mixer 7 is in a state in which one rotating engagement piece 91 is engaged with one of the second engaged grooves 105B, and the other rotating engagement piece 91' is engaged with the other second engaged groove 105B'. That is, the width direction Y of the mixer exterior body 23 and the width direction Y of the inner member IM do not coincide with each other. In this state, the circular wall portion 41a of the syringe 3 can be inserted into the second space S2 surrounded by the second peripheral wall portion 99 of the mixer exterior body 23 only when the positions of the first groove portions 107Aa, 107Ba, and 107Ca of the recesses 107A, 107B, and 107C face the three protruding pieces 45A, 45B, and 45C of the syringe 3, respectively. Only at this time does the protruding portion 43 of the syringe 3 face the insertion portion 89 of the mixing chip body 19 , and the protruding portion 43 ′ of the syringe 3 face the insertion portion 89 ′ of the mixing chip body 19 .

[0119] The user can align the protrusion 45A and the dent 107A by aligning the arrow AR1 on the surface of the circular wall 41a with the arrow AR2 on the surface of the top wall 95. As a result, the first groove 107Aa of the dent 107A faces the protrusion 45A, the first groove 107Ba of the dent 107B faces the protrusion 45B, the first groove 107Ca of the dent 107C faces the protrusion 45C, the insertion portion 89 faces the protrusion 43, and the insertion portion 89' faces the protrusion 43'.

[0120] When the circular wall portion 41a of the syringe 3 is inserted into the second space S2, the insertion portion 89 is inserted into the protruding portion 43, and the insertion portion 89' is inserted into the protruding portion 43'. As a result, the rotational position of the inner member IM (the mixing tip main body 19 and the mixer housing 21) is fixed with respect to the syringe 3. The protruding piece 45A is inserted into the first groove portion 107Aa of the recess 107A and abuts against the step portion 98. The protruding piece 45B is inserted into the first groove portion 107Ba of the recess 107B and abuts against the step portion 98. The protruding piece 45C is inserted into the first groove portion 107Ca of the recess 107C and abuts against the step portion 98.

[0121] Then, in this state, when the mixer outer casing 23 rotates around the central axis CA, the inner member IM (the mixing tip main body 19 and the mixer housing 21) does not rotate, and only the mixer outer casing 23, which is the outer casing OM, rotates, resulting in the state shown in Figure 25.

[0122] FIG. 25 is a bottom view of the static mixer 7 after only the mixer exterior body 23 has rotated (the inserted syringe 3 is not shown). When only the mixer exterior body 23 has rotated, one of the rotary engagement pieces 91 engages with one of the first engaged grooves 105A, and the other rotary engagement piece 91' engages with the other first engaged groove 105A'. The protruding piece 45A enters the second groove 107Ab along the step portion 98 from the end of the first groove 107Aa and is exposed to the outside from the window portion 109A. The protruding piece 45B enters the second groove 107Bb along the step portion 98 from the end of the first groove 107Ba and is exposed to the outside from the window portion 109B. The protruding piece 45C enters the second groove 107Cb along the step portion 98 from the end of the first groove 107Ca and is exposed to the outside from the window portion 109C.

[0123] As a result, the protruding pieces 45A, 45B, and 45C are engaged with the recesses 107A, 107B, and 107C, respectively, and the static mixer 7 and the syringe 3 are fixed to each other.

[0124] <Function of Syringe and Paste Injector> The operation of the syringe and the paste injector of the first embodiment will be described below.

[0125] The paste injector 1, which includes a syringe body 41 having a plurality of paste storage chambers 49, 49' formed therein and in which a plurality of types of paste are individually filled, and in which the plunger 5 is pressed into the syringe 3 extending in the longitudinal direction L to discharge the paste, is generally used by a user holding the syringe 3 in one hand. At this time, the user holds the syringe body 41 of the syringe 3 between the middle finger and index finger, and presses the pressing portion 67 of the plunger 5 with the thumb. For this reason, the user needs to hold the syringe body 41 firmly between two fingers (the middle finger and the index finger).

[0126] In contrast, the syringe 3 of Example 1 includes a syringe body 41 having two paste storage chambers 49, 49' arranged side by side in the width direction Y formed therein, and the outer peripheral surface of the syringe body 41 includes a pair of width direction outer peripheral surfaces 57, 57' arranged on opposite sides to each other along the thickness direction Z, a pair of thickness direction outer peripheral surfaces 59, 59' arranged on opposite sides to each other along the width direction Y, and a pair of thickness direction outer peripheral surfaces 59, 59' between the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, between the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59, between the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59', and between the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59'. and a connecting outer peripheral surface 61 set at a position parallel to the longitudinal direction X and the width direction Y. The pair of width direction outer peripheral surfaces 57, 57' have flat portions 57A that are flat along the longitudinal direction X and the width direction Y. The connecting outer peripheral surface 61 is curved at a predetermined curvature, and smoothly connects the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59', and the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59'.

[0127] As a result, when a user holds syringe body 41 of Example 1 between two fingers (middle finger and index finger) along thickness direction Z, each finger comes into contact with flat portion 57A. Therefore, in syringe 3 of Example 1, the contact area between syringe body 41 and the fingers can be increased compared to, for example, a syringe body formed by connecting multiple cylindrical bodies whose outer circumferential surfaces are curved all around. As a result, syringe 3 of Example 1 is less slippery and easier for the user to hold.

[0128] Moreover, a label bearing information such as the ingredients of the paste contained in the syringe 3 and the expiration date is generally attached to the outer peripheral surface of the syringe body 41 by using an automatic label attachment machine. Here, in the automatic label attachment machine, a flat label is placed facing the outer peripheral surface of the syringe body 41, and with a part of the label attached to the outer peripheral surface of the syringe body 41, the syringe 3 is rotated about the central axis CA, and the label is attached by wrapping it around. For this reason, if the outer peripheral surface of the syringe body 41 has a corner, the label is bent at the corner, making it difficult for the label to wrap around, and labeling by the automatic label attachment machine is difficult.

[0129] In contrast, in the syringe 3 of Example 1, the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59, the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59', and the width direction outer peripheral surface 57' and the thickness direction outer peripheral surface 59' are smoothly continuous with each other by the connecting outer peripheral surface 61 curved with a predetermined curvature. Therefore, when the syringe 3 of Example 1 is rotated about the central axis CA and labeling is performed by an automatic labeling machine that wraps and attaches a label, the label does not bend at the boundary between the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, and the label can be smoothly deformed along the outer peripheral surface of the syringe body 41. As a result, the syringe 3 of Example 1 can be easily labeled by the automatic labeling machine.

[0130] In the syringe 3 of Example 1, groove-shaped recesses 57B extending in the longitudinal direction X are formed on the widthwise outer peripheral surfaces 57, 57' of the syringe body 41, respectively, located between the two paste storage chambers 49, 49'.

[0131] As a result, the syringe 3 of Example 1 can suppress an increase in the thickness of the syringe body 41 between the two paste storage chambers 49, 49', and can make the thickness of the syringe body 41 uniform. Therefore, the syringe 3 of Example 1 can suppress the occurrence of molding defects such as sink marks and voids when the syringe body 41 is formed from a synthetic resin, for example.

[0132] Moreover, in the syringe 3 of Example 1, the connecting outer peripheral surface 61 is formed by combining a plurality of curved surfaces set to different curvatures. As a result, the syringe 3 of Example 1 can form the shape of the outer peripheral surface of the syringe body 41 into any shape. That is, the syringe 3 of Example 1 can suppress an increase in the thickness of the syringe body 41 by setting the curvature of the connecting outer peripheral surface 61 in accordance with the curvature of the inner peripheral surfaces of the paste storage chambers 49, 49' formed inside the syringe body 41, for example. Furthermore, in the syringe 3 of Example 1, the curvature of the connecting outer peripheral surface 61 can be set in accordance with the areas of the width direction outer peripheral surfaces 57, 57' and the thickness direction outer peripheral surfaces 59, 59', for example, so that the width direction outer peripheral surface 57 and the thickness direction outer peripheral surface 59, etc. can be more smoothly connected.

[0133] In the syringe 3 of Example 1, the cross-sectional shape of the paste storage chambers 49, 49' in a direction perpendicular to the longitudinal direction X, i.e., the cross-sectional shape when viewed along the longitudinal direction X, is an ellipse shape with the long axis direction LA aligned along the thickness direction Z. Therefore, the syringe 3 of Example 1 can suppress an increase in the dimension of the syringe body 41 in the width direction Y in which the two paste storage chambers 49, 49' are aligned, and can improve the ease of holding the syringe body 41.

[0134] In addition, in the syringe 3 of Example 1, the inner surface of the paste storage chamber 49, 49' is composed of a pair of inner flat surface portions 63, 63' that are flat along the longitudinal direction X and the thickness direction Z, respectively, and a pair of inner curved surface portions 65, 65' that are curved at a predetermined curvature.

[0135] For this reason, although the length in the long axis direction LA and the length in the short axis direction SA are both the same as those of the paste storage chamber 49 in Example 1, when compared with a paste storage chamber having an elliptical cross-sectional shape in a direction perpendicular to the longitudinal direction X, the syringe 3 in Example 1 can increase the amount of paste that can be stored in the paste storage chambers 49, 49'.

[0136] The paste injector 1 of the first embodiment includes the syringe 3 of the first embodiment and the plunger 5 that is inserted into the paste storage chambers 49, 49' of the syringe 3 to push out the paste. Therefore, the paste injector 1 of the first embodiment can store a plurality of pastes individually, making it easy for a user to hold the syringe 3 and easy to label the syringe 3 using an automatic labeling machine.

[0137] Furthermore, the paste may be, for example, a dental material. The paste injector may be one used for injecting a paste that is a dental material.

[0138] Example 2 <Overall composition> Fig. 26 is an exploded perspective view of the paste injector of Example 2. Fig. 27 is a cross-sectional view of the static mixer fixed to the tip of the syringe of Example 2, cut in the width direction at a position passing through the central axis extending in the longitudinal direction. Note that, also in Example 2, the longitudinal direction (X), width direction (Y), and thickness direction (Z) are defined for the paste injector 1001 as shown in Fig. 26.

[0139] The paste injector 1001 of the second embodiment includes a syringe 1003, a plunger 1005, a static mixer 1007, and a guide tip 1009, similar to the first embodiment. The guide tip 1009 is attached to the static mixer 1007 as necessary, similar to the first embodiment. The paste injector 1001 can be used even if the guide tip 1009 is not attached to the static mixer 1007.

[0140] 26 can be fixed to the tip portion of the syringe 1003 (one end portion 1041A of the syringe body 1041) instead of the static mixer 1007. In the second embodiment, the static mixer 1007 and the cap 1011 detachably attached to the tip portion of the syringe 1003 (one end portion 1041A of the syringe body 1041) are collectively referred to as an attachment member M.

[0141] In addition, the plunger 1005 of Example 2 is composed of a plunger body 1013, an elastomer holder 1015 that loosely engages with the tip of the plunger body 1013, and a circular O-ring (elastic body) 1017 attached to the elastomer holder 1015, similar to Example 1.

[0142] In Example 2, the shapes of the syringe 1003, the static mixer 1007, and the cap 1011 are different from those in Example 1. Each of these will be described in detail below.

[0143] [Syringe] Fig. 28A is a perspective view of the tip of syringe 1003, and Fig. 28B is a plan view. Fig. 28C is a cross-sectional view of the main part taken along line XXVIII-XXVIII shown in Fig. 28B. Portions common to those in Example 1 are given reference numerals that are 1000 larger than the reference numerals given in Figs. 4A to 4D and 5, and descriptions thereof will be omitted.

[0144] In syringe 1003 of Example 2, similarly to Example 1, circular wall portion 1041a is formed at one end portion 1041A of syringe body 1041, and finger hook portion 1047 is formed at the other end portion 1041B of syringe body 1041. In addition, a pair of protrusions 1043, 1043' are formed to protrude from circular wall portion 1041a, and engagement portion 1045 consisting of three protrusion pieces 1045A, 1045B, 1045C is formed on the outer circumferential surface of circular wall portion 1041a.

[0145] In the second embodiment, the circular wall portion 1041a has a recess 1041b formed on its surface (the end surface of one end portion 1041A). The recess 1041b is formed between the periphery of the circular wall portion 1041a and the protruding portions 1043, 1043', and is provided with an appropriate step. The recess 1041b formed on the surface of the circular wall portion 1041a prevents the occurrence of sink marks when the syringe 1003 is molded from resin. Furthermore, preventing the occurrence of sink marks can suppress the inclination of the protruding portions 1043, 1043'.

[0146] Also in the second embodiment, the surface of the finger hook 1047 on the side of one end 1041A may be textured.

[0147] Furthermore, in syringe body 1041 of Example 2, the radius of curvature of connecting outer peripheral surface 1061 is set to a curved surface of R2.5, which is larger than that of connecting outer peripheral surface 61 of Example 1. As a result, in syringe 1003 of Example 2, the label attached to the outer peripheral surface of syringe body 1041 is curved more gently at connecting outer peripheral surface 1061 than in Example 1. For this reason, in syringe 1003 of Example 2, it is possible to make the label attached to the outer peripheral surface of syringe body 1041 less likely to peel off than in Example 1.

[0148] [Static Mixer] (Mixing tip body) Fig. 29A is a perspective view of the mixing chip main body 1019, and Fig. 29B is a bottom view. Fig. 29C is a cross-sectional view taken along line XXIX-XXIX shown in Fig. 29B. Portions common to those in Example 1 are given reference numerals that are 1000 larger than the reference numerals in Figs. 12A, 12B, and 13, and descriptions thereof will be omitted.

[0149] The mixing tip body 1019 of the second embodiment has a cylindrical base 1087, similar to the first embodiment. A flange 1087C extending radially outward is formed on the outer periphery of the base 1087. Two insertion parts 1089, 1089' and a pair of rotation engagement pieces 1091, 1091' are formed on a first end surface 1087A of the base 1087 facing the syringe 1003. A paste passage 1029 is formed inside the insertion part 1089, and a paste passage 1029' is formed inside the insertion part 1089'. Furthermore, a backflow prevention wall 1035 and an element group 1039 extending from the tip of the backflow prevention wall 1035 are formed on a second end surface 87B opposite to the first end surface 87A of the base 1087.

[0150] In the mixing tip main body 1019 of Example 2, the length dimension L1 along the longitudinal direction X of the base 1087 is shorter than that of the base 87 of the mixing tip main body 19 of Example 1. On the other hand, the backflow prevention wall 1035 of Example 2 has a length dimension L2 along the longitudinal direction X that is longer than that of the backflow prevention wall 35 of Example 1. Therefore, the total length L3 along the longitudinal direction X of the mixing tip main body 1019 (the length from the tip of the insertion portion 1089, 1089' to the tip of the element group 1039) is set to the same length as that of the mixing tip main body 19 of Example 1.

[0151] In the mixing tip body 1019 of the second embodiment, the tapered portion on the distal surface 1029C of the paste passage 1029 is formed in the region from the inlet 1029A to the middle of the paste passage 1029. That is, the distal surface 1029C of the second embodiment is formed in a tapered shape that gradually approaches the central axis CA toward the outlet 1029B from the inlet 1029A to the middle of the paste passage 1029. The angle of the tapered portion, that is, the angle θ between the distal surface 1029C and the straight line C1 that passes through the center point of the inlet 1029A and extends in the longitudinal direction X, is set to 45° here.

[0152] In addition, the region of the distal surface 1029C from the tapered portion to the outflow hole 1029B extends parallel to the proximal surface 1029D and the central axis CA, and is along the proximal surface 1029D and the central axis CA. That is, the area of ​​the cross section perpendicular to the central axis CA (longitudinal direction X) of the paste passage 1029 in Example 2 gradually decreases at a constant rate from the inflow hole 1029A to a midpoint of the paste passage 1029, but becomes the same size as the opening area of ​​the outflow hole 1029B from a midpoint of the paste passage 1029 to the outflow hole 1029B.

[0153] In this way, since the tapered portion of the distal surface 1029C is formed in the region from the inlet hole 1029A to a midpoint of the paste passage 1029, the paste injector 1001 of Example 2 can reduce the amount of paste flowing into the paste passage 1029 compared to the paste passage 29 of Example 1 while suppressing the formation of air bubble accumulation in the paste passage 1029, and can also reduce the amount of paste remaining in the paste passage 1029.

[0154] Since the paste passage 1029' has a similar configuration to the paste passage 1029, the reference numerals of the respective parts of the paste passage 1029 are followed by "", and the description thereof is omitted. Also in the second embodiment, the paste passage 1029 and the paste passage 1029' are formed to have the same size, and are symmetrical in shape along the width direction Y with respect to the central axis CA.

[0155] (Mixer housing) Fig. 30A is a perspective view of mixer housing 1021, and Fig. 30B is a cross-sectional view taken along line XXX-XXX shown in Fig. 30A. Portions common to those in the first embodiment are given reference numerals that are 1000 larger than the reference numerals in Fig. 14A and Fig. 15, and descriptions thereof will be omitted.

[0156] A mixer housing 1021 in the second embodiment has the same basic shape as the mixer housing 21 in the first embodiment.

[0157] The base housing portion 1093 includes a circular end wall portion 1093A that covers the second end surface 1087B of the base portion 1087 of the mixing tip main body portion 1019, and a peripheral wall portion 1093B that surrounds the base portion 1087 and has a tip that contacts the flange portion 1087C. The element housing portion 1037 extends in the longitudinal direction X from a through hole formed in the center of the end wall portion 1093A, and has a guide chip engagement groove 1037A formed on the outer circumferential surface.

[0158] A recess 1093C is provided on the inner wall of the end wall portion 1093A at a position facing the outlet holes 1029B, 1029B' of the mixing tip body 1019. An intermediate passage 1031 is formed inside the inner member IM and is partitioned by the base 1087, the backflow prevention wall 1035, and the recess 1093C (see FIG. 27).

[0159] Here, the base 1087 of the mixing tip main body 1019 of Example 2 has a length along the longitudinal direction X from the flange 1087C to the second end face 1087B that is shorter than that of Example 1. Therefore, in the mixer housing 1021 of Example 2, the length dimension L4 along the longitudinal direction X of the peripheral wall 1093B that surrounds the base 1087 and has a tip that contacts the flange 1087C is shorter than that of the peripheral wall 93B of the mixer housing 21 of Example 1.

[0160] (Mixer exterior body) Fig. 31A is a front view of mixer exterior body 1023, Fig. 31B is a side view, Fig. 31C is a plan view, and Fig. 31D is a bottom view. Fig. 31E is a cross-sectional view taken along line XXXIE-XXXIE shown in Fig. 31C, Fig. 31F is a cross-sectional view taken along line XXXIF-XXXIF shown in Fig. 31C, and Fig. 31G is a cross-sectional view taken along line XXXIG-XXXIG shown in Fig. 31A. Portions common to Example 1 are designated by reference numerals obtained by adding 1000 to the reference numerals in Figs. 16A to 16C, 17, and 18, and description thereof will be omitted.

[0161] Mixer exterior body 1023 of Example 2 includes a top wall portion 1095, a first peripheral wall portion 1097 rising from an edge portion of top wall portion 1095, and a second peripheral wall portion 1099 extending continuously via a step from first peripheral wall portion 1097. Similarly to Example 1, inside mixer exterior body 1023, a first space S1 surrounded by top wall portion 1095 and first peripheral wall portion 1097, and a second space S2 surrounded by second peripheral wall portion 1099 are formed (see FIGS. 31E and 31F).

[0162] The top wall 1095 has a regular hexagonal outer periphery, a top through-hole 1101 is formed in the center, and an arrow AR2 indicating the position of a recess 1107A is engraved on the surface (see FIG. 31C). The arrow AR2 is engraved at a position that overlaps with the recess 1107A along the central axis CA. The recess 1107A is one of the engaged portions 1107 described later.

[0163] When viewed along the central axis CA, the outer peripheral surface of the first peripheral wall portion 1097 is a regular hexagon as shown in Fig. 31C. When viewed along the central axis CA, the inner peripheral surface of the first peripheral wall portion 1097 is a circle as shown in Fig. 31D. The inner peripheral surface of the first peripheral wall portion 1097 is formed with a circumferential groove 1103, a pair of first engaged grooves 1105A, 1105A', and a pair of second engaged grooves 1105B, 1105B'.

[0164] When viewed along the central axis CA, the second peripheral wall portion 1099 has an outer circumferential surface that curves in an arc shape centered on the central axis CA and has a teardrop shape that is partially pointed outward, as shown in FIG. 31C. The pointed portion of the outer circumferential surface of the second peripheral wall portion 1099 is a sharp tip portion 1099a, and the tip of the sharp tip portion 1099a coincides with the direction indicated by the arrow AR2 formed on the top wall portion 1095. In addition, the sharp tip portion 1099a is formed with a protrusion portion 1099b that protrudes along the central axis CA from an end surface 1099B of the second peripheral wall portion 1099 (the opening of the mixer exterior body 1023 into which the syringe 1003 is inserted). Therefore, the protrusion portion 1099b is formed at a position that coincides with the position at which the recess 1107A, which is one of the engaged portions 1107, is formed in the circumferential direction centered on the central axis CA.

[0165] The inner peripheral surface of the second peripheral wall portion 1099 is formed with a step portion 1098, a second step portion 1098A, and an engaged portion 1107 constituted by three recesses 1107A, 1107B, and 1107C.

[0166] The step portion 1098 is formed at the boundary between the first peripheral wall portion 1097 and the second peripheral wall portion 1099, and is a stepped unevenness that narrows the inner diameter of the mixer outer casing 1023 toward the top wall portion 1095. The step portion 1098 extends in the circumferential direction (the rotation direction of the inner member IM), and when the static mixer 1007 is attached to the tip of the syringe 1003, the circular wall portion 1041a of the syringe 1003 abuts against the step portion 1098 (see FIG. 27).

[0167] The second step portion 1098A is a stepped unevenness that narrows the inner diameter of the mixer exterior body 1023 toward the top wall portion 1095, and is formed at a position closer to an end face 1099B of the second circumferential wall portion 1099 than the step portion 1098. The second step portion 1098A extends in the circumferential direction (the rotation direction of the inner member IM), and when the static mixer 1007 is attached to the tip of the syringe 1003, a step portion 1049c formed on the outer circumferential surface of the paste storage chambers 1049, 1049' of the syringe 1003 abuts against it (see FIG. 27).

[0168] The recesses 1107A, 1107B, and 1107C have first grooves 1107Aa, 1107Ba, and 1107Ca and second grooves 1107Ab, 1107Bb, and 1107Cb, respectively, as in the first embodiment. Also, windows 1109A, 1109B, and 1109C penetrating the second peripheral wall 1099 are formed at positions corresponding to the second grooves 1107Ab, 1107Bb, and 1107Cb, respectively. The first grooves 1107Aa, 1107Ba, and 1107Ca open to the second step 1098A and extend to the step 1098 along the longitudinal direction X (center axis CA).

[0169] Furthermore, the mixer exterior body 1023 of the second embodiment is formed with a cylindrical wall portion 1098B that rises from the edge of the second step portion 1098A along the central axis CA and forms an opening of the mixer exterior body 1023. The cylindrical wall portion 1098B is a cylindrical wall surface that surrounds the periphery of the step portion 1049c formed on the outer circumferential surface of the paste storage chamber 1049, 1049' when the static mixer 1007 is attached to the tip of the syringe 1003. The cylindrical wall portion 1098B rises from the edge of the second step portion 1098A, so that the first groove portions 1107Aa, 1107Ba, and 1107Ca are each opened inside the cylindrical wall portion 1098B. That is, the cylindrical wall portion 1098B protrudes along the central axis CA beyond the engaged portion 1107.

[0170] [cap] (Cap exterior body) Fig. 32A is a front view of cap exterior body 1027, Fig. 32B is a side view, Fig. 32C is a plan view, and Fig. 32D is a bottom view. Fig. 32E is a cross-sectional view taken along line XXXIIE-XXXIIE shown in Fig. 32C, Fig. 32F is a cross-sectional view taken along line XXXIIF-XXXIIF shown in Fig. 32C, and Fig. 32G is a cross-sectional view taken along line XXXIIG-XXXIIG shown in Fig. 32A. Portions common to Example 1 are designated by reference numerals obtained by adding 1000 to the reference numerals in Figs. 21A to 21C, 22, and 23, and description thereof will be omitted.

[0171] Moreover, since the cap inner member 1025 of the cap 1011 of the second embodiment has the same configuration as that of the first embodiment, the description thereof will be omitted.

[0172] Cap exterior body 1027 of Example 2 includes a top wall portion 1119, a first circumferential wall portion 1121 rising from an edge portion of top wall portion 1119, and a second circumferential wall portion 1123 extending continuously via a step from first circumferential wall portion 1121. Similarly to Example 1, inside cap exterior body 1027, a first space S1 surrounded by top wall portion 1119 and first circumferential wall portion 1121, and a second space S2 surrounded by second circumferential wall portion 1123 are formed (see FIGS. 32E and 32F).

[0173] The top wall 1119 is a portion that closes the first space S1. Unlike the mixing tip main body 1019, the top wall 1119 is made of a curved plate member, and no top through-cylinder is formed in the center. An arrow AR2 indicating the position of a dent 1129A (described later) is engraved on the surface of the top wall 1119 (see FIG. 32C). The arrow AR2 is engraved at a position that overlaps with the dent 1129A along the central axis CA. The dent 1129A is one of the engaged portions 1129 (described later).

[0174] When viewed along the central axis CA, the outer peripheral surface of the first circumferential wall portion 1121 has a regular hexagonal shape as shown in Fig. 32C. When viewed along the central axis CA, the inner peripheral surface of the first circumferential wall portion 1121 has a circular shape as shown in Fig. 32D. The inner peripheral surface of the first circumferential wall portion 1121 is formed with a circumferential groove 1125, a pair of first engaged grooves 1127A, 1127A', and a pair of second engaged grooves 1127B, 1127B'.

[0175] When viewed along the central axis CA, the second peripheral wall portion 1123 has an outer peripheral surface that curves in an arc shape centered on the central axis CA and has a teardrop shape that is partially pointed outward, as shown in FIG. 32C. The pointed portion of the outer peripheral surface of the second peripheral wall portion 1123 is a sharp tip portion 1123a, and the tip of the sharp tip portion 1123a coincides with the direction indicated by the arrow AR2 formed on the top wall portion 1119. In addition, the sharp tip portion 1123a is formed with a protrusion portion 1123b that protrudes along the central axis CA from an end surface 1123B of the second peripheral wall portion 1123 (the opening of the cap exterior body 1027 into which the syringe 1003 is inserted). Therefore, the protrusion portion 1123b is formed at a position that coincides with the position at which the recess 1129A, which is one of the engaged portions 1129, is formed in the circumferential direction centered on the central axis CA.

[0176] The inner peripheral surface of the second circumferential wall portion 1123 is formed with a step portion 1120, a second step portion 1120A, and an engaged portion 1129 constituted by three recesses 1129A, 1129B, and 1129C.

[0177] The step portion 1120 is formed at the boundary between the first circumferential wall portion 1121 and the second circumferential wall portion 1123, and is a stepped unevenness that narrows the inner diameter of the cap exterior body 1027 toward the top wall portion 1119. The step portion 1120 extends in the circumferential direction (the rotation direction of the inner member IM), and is abutted against the circular wall portion 1041a of the syringe 1003 when the cap 1011 is attached to the tip of the syringe 1003 (see FIG. 27).

[0178] The second step portion 1120A is a stepped unevenness that narrows the inner diameter of the cap exterior body 1027 toward the top wall portion 1119, and is formed at a position closer to an end surface 1123B of the second circumferential wall portion 1123 than the step portion 1120. The second step portion 1120A extends in the circumferential direction (the rotation direction of the inner member IM), and when the cap 1011 is attached to the tip of the syringe 1003, a step portion 1049c formed on the outer circumferential surface of the paste storage chambers 1049, 1049' of the syringe 1003 abuts against it (see FIG. 27).

[0179] The recesses 1129A, 1129B, and 1129C have first grooves 1129Aa, 1129Ba, and 1129Ca and second grooves 1120Ab, 1129Bb, and 1129Cb, respectively, as in the first embodiment. Also, windows 1131A, 1131B, and 1131C penetrating the second peripheral wall 1123 are formed at positions corresponding to the second grooves 1129Ab, 1129Bb, and 1129Cb, respectively. The first grooves 1129Aa, 1129Ba, and 1129Ca open to the second stepped portion 1120A and extend to the stepped portion 1120 along the longitudinal direction X (center axis CA).

[0180] Furthermore, the cap exterior body 1027 of the second embodiment is formed with a cylindrical wall portion 1120B that rises from the edge of the second step portion 1120A along the central axis CA and forms an opening of the cap exterior body 1027. The cylindrical wall portion 1120B is a cylindrical wall surface that surrounds the periphery of the step portion 1049c formed on the outer circumferential surface of the paste storage chamber 1049, 1049' when the cap 1011 is attached to the tip of the syringe 1003. By the cylindrical wall portion 1120B rising from the edge of the second step portion 1120A, the first groove portions 1129Aa, 1129Ba, and 1129Ca are each opened inside the cylindrical wall portion 1120B. That is, the cylindrical wall portion 1120B protrudes along the central axis CA beyond the engaged portion 1129.

[0181] Although the first and second embodiments of the present invention have been specifically described above, the present invention is not limited to these embodiments, and it goes without saying that modifications are possible within the scope of the technical idea of ​​the present invention.

[0182] In the syringe 3 of the first embodiment, an example in which there are two paste storage chambers 49, 49' has been shown. However, the syringe of the present invention may be one in which three or more paste storage chambers are formed, as long as a plurality of paste storage chambers are formed inside the syringe body and aligned in the width direction Y.

[0183] In addition, in the syringe 3 of Example 1, an example was shown in which the groove-shaped recessed portion 57B was formed on the widthwise outer peripheral surface 57, but the recessed portion 57B does not have to be formed. In addition, the recessed portion 57B can be set to any cross-sectional shape, and does not have to have a wedge-shaped cross section.

[0184] In addition, with respect to the above description of the first and second embodiments, the following will be further disclosed. (1) A syringe having a syringe body with a plurality of paste storage chambers formed therein for filling with paste, the syringe body extending in a longitudinal direction, The plurality of paste storage chambers are arranged in a width direction perpendicular to the longitudinal direction, the outer circumferential surface of the syringe body includes a pair of width direction outer circumferential surfaces arranged on opposite sides to each other along a thickness direction perpendicular to the longitudinal direction and the width direction, a pair of thickness direction outer circumferential surfaces arranged on opposite sides to each other along the width direction, and a connecting outer circumferential surface set between the width direction outer circumferential surfaces and the thickness direction outer circumferential surfaces, The outer circumferential surface in the width direction has a flat portion that is flat along the longitudinal direction and the width direction, The connecting outer circumferential surface is curved at a predetermined curvature. The syringe is characterized by: (2) In the syringe described in (1), The outer circumferential surface in the width direction is provided with groove-shaped recesses located between the paste storage chambers and extending in the longitudinal direction. A syringe characterized by: (3) In the syringe described in (1) or (2), The connecting outer circumferential surface is formed by combining a plurality of curved surfaces set to different curvatures. A syringe characterized by: (4) A syringe according to any one of (1) to (3), The paste storage chamber has a cross-sectional shape in a direction perpendicular to the longitudinal direction that is an ellipse whose major axis direction is along the thickness direction. A syringe characterized by: (5) In the syringe described in (4), The inner peripheral surface of the paste storage chamber is composed of an inner flat surface portion that is flat along the longitudinal direction and the thickness direction, and an inner curved surface portion that is curved at a predetermined curvature. A syringe characterized by: (6) A syringe according to any one of (1) to (5) above, and a plunger inserted into the paste storage chamber of the syringe to push out the paste. A paste injector comprising: (7) In the paste injector according to (6), Used to inject dental paste Features a paste injector. [Explanation of symbols]

[0185] 1,1001 Paste injector 3,1003 Syringe 5,1005 Plunger 7,1007 Static Mixer 9,1009 Guide Chip 11,1011 Caps 13,1013 Plunger body 15,1015 Elastic holder 17,1017 O-ring (elastic body) 19,1019 Mixing tip body 21,1021 Mixer housing 23,1023 Mixer exterior body 25,1025 Cap inner part 27,1027 Cap exterior body 29,29´,1029,1029´ Paste passage 29A,29A´,1029A,1029A´ Inflow hole 29B,29B´,1029B,1029B´ Outflow hole 29C,29C´,1029C,1029C´ Distal surface 29D,29D´,1029D,1029D´ Proximal surface 31 Middle Passage 33,1033 Mixing passage 35,1035 Backflow prevention wall 37,1037 Element housing part 39,1039 elements 41,1041 Syringe body 41a, 1041a Circular wall 1041b Recess 43,43´,1043,1043´ Protrusion 45,1045 Engagement part 45A,45B,45C,1045A,1045B,1045C Projecting piece 47,1047 Finger rest 49,49´,1049,1049´ Paste Storage Room 51,51´,1051,1051´ Outlet 53,53´ Filling port 55 Anti-slip projection 57,57´ Width direction outer circumferential surface 59,59´ Outer periphery in thickness direction 61 Connection outer surface 63,63´ Inner flat surface part 65,65´ Inner curved surface part 67 Pressing part 69,69´ Rod-shaped part 71A Thickness direction wall 71B Width wall section 73,73´ Protrusion 75,75´ Hollow section 77,77´ Protrusion 79,79´ Holder engagement part 81 Torso 83 Top 85 Neck 87,1087 base 87A,1087A 1st end surface 87B,1087B 2nd end surface 87C, 1087C Flange part 89,89´,1089,1089´ Insertion 91,91,1091,1091´ Rotating engagement piece 93,1093 Base housing part 93A,1093A End wall 93B,1093B Peripheral wall part 93C,1093C Concave 95,1095 Top wall 97,1097 1st peripheral wall part 98,1098 Step 99,1099 Second peripheral wall part 99A Long side 99B,1099B End face 1099a Sharp part 1099b Protrusion 101,1101 Top through tube 103,1103 Circumferential groove 105A,105A´,1105A,1105A´ 1st engaged groove The second engaged groove of 105B, 105B´, 1105B, 1105B´ Engaged parts of 107, 1107 The first groove parts of 107Aa, 107Ba, 107Ca The first groove parts of 1107Aa, 1107Ba, 1107Ca The second groove parts of 107Ab, 107Bb, 107Cb The second groove parts of 1107Ab, 1107Bb, 1107Cb Window parts of 109A, 109B, 109C, 1109A, 1109B, 1109C Base part of 111 Insertion parts of 113, 113´ Rotational engagement pieces of 115, 115´ Bottomed recess of 117 Top wall parts of 119, 1119 Step parts of 120, 1120 The first circumferential wall parts of 121, 1121 The second circumferential wall parts of 123, 1123 Long side part of 123A End faces of 123B, 1123B Sharp part of 1123a Protrusion part of 1123b Circumferential direction grooves of 125, 1125 The first engaged grooves of 127A, 127A´, 1127A, 1127A´ The second engaged grooves of 127B, 127B´, 1127B, 1127B´ Engaged parts of 129, 1129 The first groove parts of 129Aa, 129Ba, 129Ca The first groove parts of 1129Aa, 1129Ba, 1129Ca The second groove parts of 129Ab, 129Bb, 129Cb The second groove parts of 1129Ab, 1129Bb, 1129Cb Window parts of 131A, 131B, 131C, 1131A, 1131B, 1131C Mounting member M Inner member IM Exterior body OM Central axis CA Longitudinal direction X Width direction Y Z thickness direction

Claims

1. A syringe having a syringe body with a plurality of paste storage chambers formed therein for filling with paste, the syringe extending in a longitudinal direction, The plurality of paste storage chambers are arranged in a width direction perpendicular to the longitudinal direction, the outer circumferential surface of the syringe body includes a pair of width direction outer circumferential surfaces arranged on opposite sides to each other along a thickness direction perpendicular to the longitudinal direction and the width direction, a pair of thickness direction outer circumferential surfaces arranged on opposite sides to each other along the width direction, and a connecting outer circumferential surface set between the width direction outer circumferential surfaces and the thickness direction outer circumferential surfaces, The outer circumferential surface in the width direction has a flat portion that is flat along the longitudinal direction and the width direction, The connecting outer circumferential surface is curved at a predetermined curvature. The syringe is characterized by:

2. 2. The syringe according to claim 1, The outer circumferential surface in the width direction is provided with groove-shaped recesses located between the paste storage chambers and extending in the longitudinal direction. A syringe characterized by:

3. The syringe according to claim 1 or 2, The connecting outer circumferential surface is formed by combining a plurality of curved surfaces set to different curvatures. A syringe characterized by:

4. The syringe according to claim 1 or 2, The paste storage chamber has a cross-sectional shape in a direction perpendicular to the longitudinal direction that is an ellipse whose major axis direction is along the thickness direction. A syringe characterized by:

5. The syringe according to claim 4, The inner peripheral surface of the paste storage chamber is composed of an inner flat surface portion that is flat along the longitudinal direction and the thickness direction, and an inner curved surface portion that is curved at a predetermined curvature. A syringe characterized by:

6. 3. A paste injector comprising: the syringe according to claim 1; and a plunger inserted into the paste storage chamber of the syringe to push out the paste.

7. 7. The paste injector of claim 6, Used to inject dental paste A paste injector comprising:

Images