JP2018108146A - Syringe-type injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel syringe-type injector capable of injecting a content by dividing a content into small quantities and injecting a small quantity.SOLUTION: A plunger 3 includes a first shaft member 3a having a piston 4 at a tip end, and a second shaft member 3b, and a plurality of elastic pieces 31, 32, and 33 in the first shaft member 3a include respectively a slide projection and a locking projection. A pressing shaft 41 of the second shaft member 3b includes: a support part that, when a slide projection enters inside a syringe 2, supports a free end from a radially inside and locks a locking projection to a rear end of the syringe 2; and a pressing part capable of axially pressing the free end of each of the elastic pieces 31, 32, and 33 whose lock of the locking projection is released by restitutive force of the elastic piece.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a syringe type ejector including a syringe and a plunger that can be pushed into the syringe, and relates to a technique for pushing the plunger in a stepwise manner.

  Some syringe-type ejectors, for example, push a plunger into a syringe and take out contents such as a chemical solution (see, for example, Patent Document 1). Moreover, what divides the content and erupts is also known (for example, refer patent document 2).

JP 7-213612 A Japanese Patent No. 5847662

  However, the conventional syringe-type ejector that can be ejected into small portions has many components, and there is a concern that the assembly thereof is likely to be complicated.

  An object of the present invention is to provide a novel syringe-type ejector that can divide the contents into small portions and eject them with a simple configuration.

The present invention has been made to solve the above problems, and the syringe-type ejector of the present invention includes a syringe and a plunger that can be pushed into the inside of the syringe.
The plunger has a first shaft member having a piston at a tip, and a second shaft member held on the rear side of the first shaft member,
The first shaft member has a plurality of elastic pieces extending from a base end portion toward a rear free end portion at different axial positions,
Each of the elastic pieces has a sliding projection that enters from the rear end opening of the syringe and can slide on the inner peripheral surface of the syringe, and is located behind the sliding projection, and the rear end of the syringe. And a locking projection to be locked to,
The second shaft member has a pressing shaft located inside the cylindrical portion of the first shaft member,
The pressing shaft supports the free end of the elastic piece from the inside in the radial direction when the sliding protrusion enters the syringe, and locks the locking protrusion to the rear end of the syringe. And a pressing portion capable of axially pressing the free end portion of the elastic piece whose locking projection is released by the restoring force of the elastic piece starting from the sliding projection. It is characterized by that.

  In the syringe-type ejector of the present invention, it is preferable that the two elastic pieces whose axial positions are adjacent are arranged at different circumferential positions. Note that “two elastic pieces whose axial positions are adjacent” means two elastic pieces including one elastic piece and another elastic piece having the closest axial distance from the one elastic piece. To do.

  In the syringe-type ejector according to the present invention, it is preferable that the two elastic pieces whose axial positions are adjacent to each other are at circumferential positions facing each other across the central axis of the first shaft member.

  In the syringe-type ejector according to the present invention, it is preferable that the two elastic pieces whose axial positions are adjacent to each other are partially overlapped in the axial direction.

  In the syringe-type ejector of the present invention, it is preferable that the second shaft member is configured not to rotate with respect to the first shaft member.

  In the syringe-type ejector according to the present invention, the outer peripheral surface of the pressing shaft is provided with an engaging protrusion that engages with the locking portion of the cylindrical portion and prevents the cylindrical portion from coming out. It is preferable.

  In the syringe-type ejector according to the present invention, it is preferable that the engagement protrusion has a function of regulating the rotation of the second shaft member with respect to the first shaft member.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the novel syringe type ejector which can divide and squirt the contents.

It is sectional drawing of the syringe type ejector which concerns on one Embodiment of this invention. It is the elements on larger scale of the syringe type ejector shown in FIG. (A) is sectional drawing in the AA line of the syringe type ejector shown in FIG. 2, (b) is sectional drawing in a BB line, (c) is sectional drawing in a CC line. FIG. It is a figure explaining the 1st ejection of the syringe type ejector shown in FIG. It is a figure which shows the state which finished the injection of the 1st time of the syringe type ejector shown in FIG. 1, and eased pushing. It is a figure explaining the 2nd ejection of the syringe type ejector shown in FIG. It is a figure which shows the state which finished pushing out of the 2nd time of the syringe type ejector shown in FIG. 1, and eased pushing. It is a figure explaining the 3rd ejection of the syringe type ejector shown in FIG. It is a figure which shows the state which finished pushing out the 3rd time of the syringe type ejector shown in FIG. 1, and eased pushing. It is a figure explaining the 4th ejection of the syringe type ejector shown in FIG.

  Hereinafter, with reference to drawings, the syringe type ejector 1 which is one Embodiment of this invention is demonstrated in detail. FIG. 1 is a cross-sectional view showing a cross section passing through a central axis O of a syringe type ejector 1 according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of the syringe type ejector 1. 3A is a cross-sectional view taken along the line AA in FIG. 2, FIG. 3B is a cross-sectional view taken along the line BB in FIG. 2, and FIG. It is sectional drawing in CC line. In the present specification, claims, abstract and drawings, the direction in which the contents are ejected (the left side in FIG. 1) is the front, and the side on which the second shaft member 3b is located (the right side in FIG. 1) is the rear. And

  As shown in FIG. 1, a syringe-type ejector 1 according to an embodiment of the present invention includes a synthetic resin or glass syringe 2 and a synthetic resin plunger 3 inserted into the syringe 2.

  The syringe 2 has, for example, a hollow body portion 21 that can be filled with a liquid content, and the body portion 21 is integrally provided with a distal end portion 23 via a shoulder portion 22. In the present embodiment, the distal end portion 23 has a smaller diameter than the trunk portion 21. Note that the distal end portion 23 may not be smaller in diameter than the body portion 21, and another member may be attached. A finger hook 24 is provided at the rear end of the body 21. In the present embodiment, the finger hook portion 24 is configured by an annular cover member attached to a flange portion 21 a that protrudes radially outward from the rear end of the trunk portion 21, but has a diameter provided integrally with the trunk portion 21. You may comprise by the protrusion part which protrudes in the direction outer side. Further, a cap for sealing the distal end through hole 23 a may be attached to the distal end portion 23.

  The plunger 3 has a first shaft member 3a and a second shaft member 3b held behind the first shaft member 3a.

  The first shaft member 3 a includes a piston 4 at the tip stored in the syringe 2. The piston 4 is made of, for example, an elastic material such as rubber, elastomer, or silicon, and can slide on the inner peripheral surface of the body portion 21 of the syringe 2.

  A storage space S is formed between the syringe 2 and the piston 4, and contents are stored in the storage space S. The contents stored in the storage space S are pumped to the front end through hole 23a formed in the front end portion 23 by being pushed forward of the plunger 3, and are ejected (discharged) from the front end through hole 23a.

  The first shaft member 3 a includes a first elastic piece 31, a second elastic piece 32, and a third elastic piece 33 that are provided at different axial positions (positions along the central axis O). In the present embodiment, the first elastic piece 31, the second elastic piece 32, and the third elastic piece 33 have the same shape, but are not limited thereto, and may have different shapes. The first shaft member 3 a includes a piston holding portion 34 that holds the piston 4, a cross-shaped shaft portion 35 that extends rearward from the piston holding portion 34, and a cylindrical portion 36 that extends rearward of the shaft portion 35. The first elastic piece 31, the second elastic piece 32, and the third elastic piece 33 are provided in the cylindrical portion 36.

  As shown in FIGS. 1 and 2, the first elastic piece 31 extends from the base end portion 31 a connected to the cylindrical portion 36 toward the rear free end portion 31 b and is radially inward (center axis O side). Alternatively, it can be elastically deformed (bend deformation) radially outward. The first elastic piece 31 is defined by a first opening 37 a penetrating the cylindrical portion 36. The first elastic piece 31 is located behind the sliding protrusion 31c, and a sliding protrusion 31c that can enter the rear end opening 25 of the syringe 2 and slide on the inner peripheral surface of the syringe 2. A locking projection 31d that can be locked at the rear end is provided. The sliding projection 31c has a tapered portion 31e that is tapered toward the front, and the sliding projection 31c can easily enter the syringe 2 from the rear end opening 25 smoothly. Between the sliding projection 31c and the locking projection 31d, there is provided a plate portion 31f that is more easily elastically deformed than the other portions. Note that the outer diameters of the sliding protrusion 31 c and the locking protrusion 31 d in the initial state shown in FIG. 1 are larger than the inner diameter of the body portion 21 of the syringe 2.

  The second elastic piece 32 is located on the rear side of the first elastic piece 31 in the axial direction along the central axis O. Here, the first elastic piece 31 and the second elastic piece 32 are adjacent to each other in the axial direction. Similarly, the second elastic piece 32 and the third elastic piece 33 are adjacent to each other in the axial direction. The first elastic piece 31 and the third elastic piece 33 are not adjacent to each other in the axial direction. The second elastic piece 32 is provided at a circumferential position different from the first elastic piece 31 in the circumferential direction around the central axis O. More specifically, the second elastic piece 32 is provided at a circumferential position facing the first elastic piece 31 across the central axis O.

  Similar to the first elastic piece 31, the second elastic piece 32 extends from the base end portion 32 a toward the rear free end portion 32 b, and is defined by a second opening 37 b penetrating the cylindrical portion 36. ing. Further, similarly to the first elastic piece 31, the second elastic piece 32 is provided with a sliding protrusion 32c having a tapered portion 32e and a locking protrusion 32d positioned behind the sliding protrusion 32c. A plate portion 32f is provided between the sliding projection 32c and the locking projection 32d. In the present embodiment, the base end portion 32 a side of the second elastic piece 32 is disposed so as to overlap the first elastic piece 31 in the axial direction.

  The third elastic piece 33 is located on the rear side of the second elastic piece 32 in the axial direction along the central axis O. The third elastic piece 33, which is adjacent to the second elastic piece 32 in the axial direction of the second elastic piece 32, is provided at a circumferential position different from the second elastic piece 32. More specifically, the third elastic piece 33 is provided at a circumferential position facing the second elastic piece 32 across the central axis O. The third elastic piece 33 is provided at the same circumferential position as the first elastic piece 31.

  Similarly to the first elastic piece 31 and the second elastic piece 32, the third elastic piece 33 extends from the base end portion 33 a toward the rear free end portion 33 b, and passes through the cylindrical portion 36. A partition is formed by the opening 37c. The third elastic piece 33 is provided with a sliding projection 33c having a tapered portion 33e and a locking projection 33d. A plate portion 33f is provided between the sliding projection 33c and the locking projection 33d. In the present embodiment, the base end portion 33a side of the third elastic piece 33 is disposed so as to partially overlap the second elastic piece 32 in the axial direction.

  A rib 38 protruding outward in the radial direction is provided on the outer peripheral surface of the first shaft member 3a. In the present embodiment, a pair of ribs 38 are opposed to each other on both sides of the central axis O at four locations in the axial direction of the first shaft member 3a. Each of the ribs 38 can be engaged with the opening edge of the rear end opening 25 (the inner peripheral edge of the finger hook portion 24) when entering the syringe 2 from the rear end opening 25 by pushing the plunger 3. . In order for each rib 38 to get over the opening edge of the rear end opening 25, a certain amount of pressing force is required. Therefore, since the user pushes the plunger 3 in a state where the pressing force is increased, the contents are ejected vigorously. The rib 38 is not an essential configuration.

  The second shaft member 3b is held on the rear side of the first shaft member 3a. The second shaft member 3 b includes a pressing shaft 41 disposed inside the cylindrical portion 36 and a pressing flange 42 provided at the rear portion of the pressing shaft 41. The pressing shaft 41 has a cylindrical shape having an outer diameter corresponding to the inner diameter of the cylindrical portion 36 of the first shaft member 3a, and includes a first notch portion 43 on the front end side and a second notch portion 44 on the rear side. And are formed. The pressing shaft 41 is not limited to a cylindrical shape, and may be a solid rod shape.

  When the sliding projection 31c of the first elastic piece 31 enters the syringe 2, the pressing projection 41 of the second shaft member 3b supports the free end portion 31b from the inside in the radial direction and the locking projection 31d to the syringe. The 1st support part 45a latched in 2 rear ends (edge part of the rear-end opening part 25) is provided. The first support portion 45a has a tapered surface whose outer surface is tapered toward the front.

  The pressing shaft 41 includes a second support portion 45b that supports the free end portion 32b from the radially inner side when the sliding protrusion 32c of the second elastic piece 32 enters the syringe 2, and a third elastic piece. When the 33 sliding protrusions 33c enter the syringe 2, a third support portion 45c that supports the free end portion 33b from the radially inner side is provided.

  Further, on the pressing shaft 41 of the second shaft member 3b, the engagement protrusion 31d is engaged with the rear end of the syringe 2 by the restoring force of the first elastic piece 31 starting from the sliding protrusion 31c of the first elastic piece 31. A first pressing portion 46a is provided that can press the free end portion 31b of the first elastic piece 31 released from the stop in the axial direction. The first pressing portion 46 a is provided at the tip of the pressing shaft 41.

  Further, the pressing shaft 41 of the second shaft member 3b includes a second pressing portion 46b positioned on the rear side of the first notch portion 43 and a third pressing portion 46c positioned on the rear side of the second notch portion 44. And are provided.

  As shown in FIGS. 2 and 3A, an engaging protrusion 41 a that protrudes radially outward is provided on the outer peripheral surface of the pressing shaft 41. When the pressing shaft 41 is inserted inside the cylindrical portion 36, the engagement protrusion 41a is aligned with the enlarged diameter groove portion 36a provided on the inner peripheral surface of the rear end portion of the cylindrical portion 36, whereby the first shaft member 3a is aligned. The circumferential position of the second shaft member 3b can be set to a predetermined circumferential position. That is, by providing the engaging protrusion 41a and the enlarged-diameter groove 36a, alignment during assembly is facilitated.

  As the pressing shaft 41 enters the cylindrical portion 36, the engaging protrusion 41a is disposed in the second opening 37b so as to get over the inclined surface 36b provided at the front end portion of the enlarged diameter groove portion 36a. The engagement protrusion 41a disposed in the second opening 37b is sandwiched between edges on both sides in the circumferential direction of the second opening 37b in the cylindrical portion 36, and movement in the circumferential direction is restricted. That is, the engagement protrusion 41a also has a function of restricting the rotation of the second shaft member 3b relative to the first shaft member 3a during use. Thus, by suppressing the relative rotation of the second shaft member 3b with respect to the first shaft member 3a, the circumferential position of the second shaft member 3b with respect to the first shaft member 3a is prevented from shifting, It is possible to prevent malfunction. Further, in the present embodiment, the pressing shaft 41 is provided with a detent rib 41b (see FIGS. 2 and 3A), and the relative rotation of the second shaft member 3b with respect to the first shaft member 3a is suppressed. doing. As a configuration for suppressing the rotation of the second shaft member 3b with respect to the first shaft member 3a, it is only necessary to have at least one of the engaging protrusion 41a and the rotation prevention rib 41b.

  Further, the engaging protrusion 41a disposed in the second opening 37b engages with the locking portion 36c of the cylindrical portion 36 (the axial edge formed by the second opening 37b in the cylindrical portion 36) to form a cylinder. It prevents the part 36 from coming out. As a result, the second shaft member 3b is held against the first shaft member 3a. In the initial state shown in FIG. 1, the engagement protrusion 41 a is separated from the locking portion 36 c of the cylindrical portion 36 in the axial direction. That is, the second shaft member 3b is movable in the axial direction with respect to the first shaft member 3a within a range until the engaging protrusion 41a engages with the locking portion 36c of the cylindrical portion 36. .

  Below, the usage method of the syringe type ejector 1 of this embodiment is demonstrated. In addition, the syringe type ejector 1 of this embodiment can eject the predetermined amount by subdividing the contents in the accommodation space S by pushing the plunger 3 stepwise. Further, the syringe-type ejector 1 of the present embodiment can be used at various ejection angles depending on the application. For example, the syringe-type ejector 1 can be used with the tip through-hole 23a positioned upward in the vertical direction and downward in the reverse direction. It is.

  First, the first injection is performed by pushing the plunger 3 into the syringe 2 from the initial state shown in FIGS. 1 and 2 to the state shown in FIG. Specifically, the pressing flange 42 of the second shaft member 3b is pushed forward from the state shown in FIGS. In the present embodiment, the pressing force applied to the second shaft member 3b is transmitted to the first shaft member 3a via the rear end surface 36d of the cylindrical portion 36 that contacts the front surface 42a of the pressing flange 42. In addition, since the pressing shaft 41 of the second shaft member 3b is inserted into the cylindrical portion 36 of the first shaft member 3a, the second shaft member 3b may be wobbled or inclined with respect to the first shaft member 3a when pressed. And a stable pressing operation is possible.

  As the plunger 3 is pushed, the first elastic piece 31 gradually enters the syringe 2 from the base end portion 31a side. The sliding protrusion 31c of the first elastic piece 31 entering the syringe 2 abuts on and slides on the inner peripheral edge of the rear end opening 25 and the inner peripheral surface of the syringe 2, so that the first elastic piece 31 A force is applied to the radially inner side (the direction toward the central axis O). At this time, since the free end portion 31b of the first elastic piece 31 is supported from the radially inner side by the first support portion 45a, the free end portion 31b side is restricted from moving radially inward. For this reason, as shown in FIG. 4, the first elastic piece 31 is elastically bent and deformed radially inward in the region between the base end portion 31 a and the free end portion 31 b. In addition, due to the restoring force of the first elastic piece 31 that has been bent and deformed, the first support portion 45a is given a force toward the inner side in the radial direction and a force toward the rear side from the free end portion 31b. The rearward displacement of the second shaft member 3b is suppressed.

  When the first elastic piece 31 enters the syringe 2, since the tapered protrusion 31 c is provided with the tapered portion 31 e, the first elastic piece 31 can smoothly enter the syringe 2. In the present embodiment, since the plate portion 31f is provided between the sliding projection 31c and the locking projection 31d, it is easy to bend and deform.

  As shown in FIG. 4, the locking protrusion 31 d supported from the radially inner side by the first support portion 45 a is locked to the rear end of the syringe 2 (inner peripheral edge portion of the rear end opening 25). 3 is stopped, and the first ejection ends.

  After the locking projection 31d is locked to the rear end of the syringe 2, when the pressing force forward of the pressing flange 42 is eased or released, the second shaft member 3b is moved backward by the restoring force of the first elastic piece 31. 5 is pushed and moved to the state shown in FIG. In the present embodiment, since the outer surface of the first support portion 45a is a tapered surface, the free end portion 31b due to the restoring force of the first elastic piece 31 is converted to a force toward the rear in the radial direction. Therefore, the second shaft member 3b can be pushed out rearward smoothly. In addition, in the free end part 31b of the 1st elastic piece 31, you may provide the taper surface which diameter-reduces toward the front so that it may become substantially parallel to the 1st support part 45a. Moreover, it is good also as a structure which retracts the 2nd shaft member 3b manually, In this case, it is not necessary to provide a taper surface.

  As shown in FIG. 5, the second shaft member 3 b moves rearward, whereby the first support portion 45 a moves rearward from the free end portion 31 b of the first elastic piece 31. Therefore, the free end 31b of the first elastic piece 31 moves radially inward, and the locking of the locking projection 31d to the rear end of the syringe 2 is released. In the state of FIG. 5, the front surface 42 a of the pressing flange 42 and the rear end surface 36 d of the cylindrical portion 36 are not in contact with each other.

  Next, the second ejection is performed by pushing the plunger 3 into the syringe 2 from the state shown in FIG. 5 to the state shown in FIG. 6. As shown in FIG. 5, in the second ejection, the first pressing portion 46 a presses the free end portion 31 b of the first elastic piece 31 in the axial direction.

  As the plunger 3 is pushed, the second elastic piece 32 gradually enters the syringe 2 with elastic deformation. In that case, the 2nd elastic piece 32 which carried out the bending deformation will enter in the 1st notch part 43 formed in the press shaft 41 of the 2nd shaft member 3b.

  As shown in FIG. 6, the locking protrusion 32d supported from the radially inner side by the second support portion 45b is locked to the rear end of the syringe 2, thereby stopping the plunger 3 from entering and the second ejection. Ends. When the pressing force to the plunger 3 is relaxed or released in this state, the second shaft member 3b is pushed and moved rearward by the restoring force of the second elastic piece 32, resulting in the state shown in FIG. It becomes possible to erupt.

  Next, the third ejection is performed by pushing the plunger 3 into the syringe 2 from the state shown in FIG. 7 to the state shown in FIG. As shown in FIG. 7, in the third ejection, the second pressing portion 46 b presses the free end portion 32 b of the second elastic piece 32 in the axial direction.

  As the plunger 3 is pushed, the third elastic piece 33 gradually enters the syringe 2 with elastic deformation. In that case, the 3rd elastic piece 33 which carried out the bending deformation will enter in the 2nd notch part 44 formed in the press shaft 41 of the 2nd shaft member 3b.

  As shown in FIG. 8, the locking protrusion 33d supported from the inside in the radial direction by the third support portion 45c is locked to the rear end of the syringe 2, thereby stopping the plunger 3 from entering and the third ejection. Ends. When the pressing force to the plunger 3 is relaxed or released in this state, the second shaft member 3b is pushed backward by the restoring force of the third elastic piece 33 and moves to the state shown in FIG. It becomes possible to erupt.

  Finally, the fourth ejection is performed by pushing the plunger 3 into the syringe 2 from the state shown in FIG. 9 to the state shown in FIG. As shown in FIG. 9, in the fourth ejection, the third pressing portion 46 c presses the free end portion 33 b of the third elastic piece 33 in the axial direction.

  As described above, according to the syringe-type ejector 1 of the present embodiment, the contents in the syringe 2 can be ejected in four portions. That is, the contents can be subdivided and ejected. The first shaft member 3a is provided with a plurality of elastic pieces (first elastic piece 31, second elastic piece 32, third elastic piece 33), and the second shaft member 3b is provided with a support portion (first support portion 45a, By providing the second support part 45b, the third support part 45c) and the pressing part (the first pressing part 46a, the second pressing part 46b, the third pressing part 46c), the plunger 3 can be simplified with a small number of components. It can be configured. Further, since the plunger 3 can be formed simply by inserting the pressing shaft 41 of the second shaft member 3b into the cylindrical portion 36 of the first shaft member 3a to which the piston 4 is mounted, assembly is also easy.

  Further, in the syringe-type ejector 1 of the present embodiment, the first elastic piece 31 and the second elastic piece 32 are arranged at different circumferential positions and are arranged so as to partially overlap in the axial direction. Similarly, the second elastic piece 32 and the third elastic piece 33 are arranged at different circumferential positions and are arranged so as to partially overlap in the axial direction. By setting it as such a structure, the axial direction length of the 1st shaft member 3a can be reduced, and the plunger 3 can be reduced in size. Further, by arranging a plurality of elastic pieces (the first elastic piece 31, the second elastic piece 32, the third elastic piece 33) in a balanced manner in the circumferential direction, wobbling when the plunger 3 is pushed into the syringe 2 is prevented. It is also possible to increase stability.

  Although the present invention has been described based on the illustrated examples, the present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the claims. For example, each elastic piece ( By appropriately changing the axial positions of the first elastic piece 31, the second elastic piece 32, and the third elastic piece 33), it is possible to change the ejection amount of each content from the first time to the fourth time. Further, the same amount may be ejected from the first time to the fourth time, or different amounts may be ejected. Further, the content is not limited to a liquid form as long as it can be ejected, and may be a gel form or a solid form such as a powder. Further, the number of ejections of the contents is not limited to four times, and may be three times or less or five times or more. Moreover, although the elastic piece should just be provided in two or more places, it is also possible to make an elastic piece only in one place.

DESCRIPTION OF SYMBOLS 1 Syringe type ejector 2 Syringe 3 Plunger 3a 1st shaft member 3b 2nd shaft member 4 Piston 21 trunk | drum 21a flange part 22 shoulder part 23 front-end | tip part 23a front-end through-hole 24 finger hook part 25 back end opening part 31 1st elastic piece (Elastic piece)
31a Base end portion 31b Free end portion 31c Sliding projection 31d Locking projection 31e Tapered portion 31f Plate portion 32 Second elastic piece (elastic piece)
32a Base end portion 32b Free end portion 32c Sliding projection 32d Locking projection 32e Taper portion 32f Plate portion 33 Third elastic piece (elastic piece)
33a Base end portion 33b Free end portion 33c Sliding projection 33d Locking projection 33e Taper portion 33f Plate portion 34 Piston holding portion 35 Shaft portion 36 Tube portion 36a Expanding groove portion 36b Inclined surface 36c Locking portion 36d Rear end surface 37a First opening 37b Second opening 37c Third opening 38 Rib 41 Press shaft 41a Engaging protrusion 41b Anti-rotation rib 42 Pressing flange 42a Front surface 43 First notch 44 Second notch 45a First support 45b Second support 45c 3rd support part 46a 1st press part 46b 2nd press part 46c 3rd press part O Center axis S Storage space

Claims (7)

A syringe and a plunger that can be pushed inside the syringe;
The plunger has a first shaft member having a piston at a tip, and a second shaft member held on the rear side of the first shaft member,
The first shaft member has a plurality of elastic pieces extending from a base end portion toward a rear free end portion at different axial positions,
Each of the elastic pieces has a sliding projection that enters from the rear end opening of the syringe and can slide on the inner peripheral surface of the syringe, and is located behind the sliding projection, and the rear end of the syringe. And a locking projection to be locked to,
The second shaft member has a pressing shaft located inside the cylindrical portion of the first shaft member,
The pressing shaft supports the free end of the elastic piece from the inside in the radial direction when the sliding protrusion enters the syringe, and locks the locking protrusion to the rear end of the syringe. And a pressing portion capable of axially pressing the free end portion of the elastic piece whose locking projection is released by the restoring force of the elastic piece starting from the sliding projection. A syringe-type ejector characterized by that.   The syringe-type ejector according to claim 1, wherein the two elastic pieces whose axial positions are adjacent to each other are arranged at different circumferential positions.   The syringe-type ejector according to claim 2, wherein the two elastic pieces adjacent to each other in the axial direction are at circumferential positions facing each other across the central axis of the first shaft member.   The syringe-type ejector according to claim 2 or 3, wherein the two elastic pieces adjacent to each other in the axial direction are arranged so as to partially overlap in the axial direction.   The syringe-type ejector according to any one of claims 1 to 4, wherein the second shaft member is configured not to rotate with respect to the first shaft member.   The engagement protrusion which engages with the latching | locking part of the said cylinder part, and prevents the pull-out from this cylinder part is provided in the outer peripheral surface of the said pressing shaft. The syringe-type ejector as described. The syringe-type ejector according to claim 6, wherein the engagement protrusion also has a function of restricting rotation of the second shaft member with respect to the first shaft member.

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