JP6282441B2 - Nozzle replaceable drug injector - Google Patents

Description

  The present invention relates to a nozzle exchange type drug injector in which a nozzle attachment is detachably attached to a distal end portion of a syringe.

  As this type of conventional nozzle-exchange-type dental drug injector, one disclosed in Patent Document 1 below is known. This conventional dental drug injector has a nozzle part and luer lock part integrally provided at the tip of the syringe, and the nozzle attachment (narrow mouth nozzle) can be replaced via an adapter for these nozzle part and luer lock part. (In particular, see paragraph numbers 0017 to 0019, FIG. 2).

JP 2009-11341 A

  In the conventional dental drug injector, since the nozzle attachment and the adapter are configured separately, there is a problem that the assembling work at the time of use becomes complicated and the cost is increased.

  On the other hand, although the adapter can be integrally formed with the nozzle attachment, the nozzle attachment is inserted into the patient's oral cavity and is required to have appropriate elasticity. Therefore, a predetermined amount in the molding material of the nozzle attachment is required. In general, an elastomer is mixed. When the elastomer is mixed in this way, oil bleed occurs on the surface of the molding material, and the nozzle attachment screwed into the luer lock part is loosened due to the exuded oil, resulting in a problem that proper injection of the dental drug cannot be performed. End up.

  Further, when the fitting of the nozzle part and the luer lock part and the nozzle attachment is tight in order to prevent the occurrence of looseness, the nozzle attachment cannot be attached / detached smoothly.

  Accordingly, an object of the present invention is to provide a nozzle replaceable drug injector capable of smoothly performing the attachment / detachment operation of the nozzle attachment and capable of preventing the loosening of the nozzle attachment due to the oil bleed. And

  In order to solve the above problems, the present invention has taken the following technical means.

  That is, the present invention includes a syringe having a nozzle part for discharging a medicine filled therein, and a nozzle attachment that is replaceably fitted to the nozzle part of the syringe, and the syringe includes the nozzle part A nozzle-type that is fixed to the lock portion by rotating the nozzle attachment in a predetermined direction up to a predetermined lock position with respect to the lock portion. In the medicine injector, the lock portion includes a first engagement portion at a predetermined position in the circumferential direction, and the nozzle attachment rotates in a reverse direction with respect to the lock portion when the nozzle attachment is rotated in the predetermined direction to the lock position. And a second engagement portion that engages with the first engagement portion in the circumferential direction.

  According to the nozzle replaceable drug injector of the present invention, even when the nozzle attachment is relatively loosely fitted to the nozzle portion and the lock portion, when the nozzle attachment is in the lock position, the first engagement portion of the lock portion The second attachment portion of the nozzle attachment is engaged in the circumferential direction, so that the reverse rotation of the nozzle attachment caused by the oil bleed is inhibited, and the nozzle attachment can be attached and detached smoothly and quickly. Can be prevented from loosening.

  In the present invention, the lock portion preferably has a luer lock structure in which an internal thread is provided on the inner peripheral surface. However, an L-shaped engagement groove is provided on the inner peripheral surface, and the nozzle attachment is first attached. It is also possible to adopt a structure that prevents axial disengagement by pushing the lock portion in the axial direction and then rotating the nozzle attachment in the circumferential direction.

  In the nozzle exchange type drug injector of the present invention described above, the nozzle portion is configured in a tapered tube shape, the nozzle attachment is screwed to the lock portion, and the nozzle attachment is rotated to the lock position (that is, locked) A throttle part in which the tip part of the nozzle part is tightly fitted when screwed into the part, and the nozzle part connected to the throttle part in the axial direction and rotated to the lock position. An extension part that loosely fits in a part other than the tip part of the nozzle part, and the tip part of the nozzle part rotates the nozzle attachment in a predetermined direction to the lock position with respect to the nozzle part. The screw can be screwed to be tightly fitted to the throttle portion. According to such a configuration, since only the tip of the nozzle portion is tightly fitted to the nozzle attachment, there is almost no resistance to the rotation operation in the middle of the rotation operation for attaching the nozzle attachment, and the nozzle attachment is more smoothly performed. When the nozzle attachment is rotated to the locked position while the attachment / detachment operation can be performed, the tip of the nozzle portion is tightly fitted to the nozzle attachment, so that the nozzle attachment can be further prevented from being loosened. It is possible to effectively prevent the liquid agent from leaking from between the outer peripheral surface of the tip portion and the inner peripheral surface of the throttle portion of the nozzle attachment. Furthermore, since the nozzle attachment is tightly fitted to the tip portion of the nozzle portion by screwing the nozzle attachment relative to the lock portion, such a tight fitting force can be obtained by a relatively light rotational operation.

  Further, the first engaging portion is a convex portion provided on the outer peripheral surface of the lock portion and protruding radially outward as viewed from the axial direction, and the nozzle attachment is a protrusion located on the outer periphery of the distal end portion of the lock portion The second engaging portion may be a convex portion that is provided on the inner peripheral portion of the protrusion and protrudes radially inward when viewed from the axial direction. According to such a configuration, the second engagement portion smoothly gets over the first engagement portion at the final stage of the rotation operation while reducing the overall configuration, and the nozzle attachment is rotated to the lock position. Sometimes a moderate lock feeling is obtained, and it becomes easier for the user to grasp that the rotation operation has been performed to the lock position. The first engaging portion and the second engaging portion are preferably raised in a hill shape, but one may be raised in a hill shape, and the other may be a square shape or the like. it can.

  In addition, one or a plurality of screw threads constituting a female screw are provided on the inner peripheral surface of the lock portion, and an engagement piece that engages with the female screw is provided on the outer peripheral surface of the nozzle attachment, When the nozzle attachment is in the locked position, the distal end portion in the predetermined direction (that is, one end portion in the circumferential direction) of the engagement piece is an edge on the axial base end side of any one of the threads that constitute the female screw. And the base end of the engagement piece in the predetermined direction (that is, the other end in the circumferential direction) contacts the edge on the axial front end side of one of the screw threads constituting the female screw. It can be set as the structure to do. Here, the edge on the axial base end side of the screw thread is an axial base end part in the middle of the spiral of the spiral screw thread, and the edge on the tip end side in the axial direction of the screw thread. It is the axial tip in the middle of the spiral of the helical thread. According to such a configuration, the nozzle attachment must be rotated in the reverse direction by engaging the engagement piece of the nozzle attachment with the female screw of the lock portion in both the axial front end side and the base end side. In this case, the nozzle attachment is not rattled in the axial direction with respect to the lock portion, and the nozzle attachment can be more securely fixed.

  In addition, the nozzle attachment may include a sealing surface that contacts the tip of the nozzle portion in the axial direction when the nozzle attachment is rotated to the lock position. According to this, the seal surface of the nozzle attachment is pressed against the tip portion of the nozzle portion, thereby preventing the medicine from leaking between the tip portion of the nozzle portion and the seal surface of the nozzle attachment.

  ADVANTAGE OF THE INVENTION According to this invention, although the attachment / detachment operation of a nozzle attachment can be performed smoothly, the loosening of the nozzle attachment resulting from an oil bleed can be prevented.

It is a whole perspective view of a nozzle exchange type medicine injection device concerning one embodiment of the present invention. It is a front longitudinal cross-sectional view of the medicine injection device. It is a side longitudinal cross-sectional view of the medicine injection device. It is a bottom view of the medicine injection device. It is an expansion perspective view of the syringe front-end | tip part of the chemical injection device. It is a perspective view of the nozzle attachment of the medicine injection device. It is a front view of the same nozzle attachment. It is a right view of the same nozzle attachment. It is a bottom view of the same nozzle attachment. It is an enlarged front view which shows the engagement structure of the syringe front-end | tip part of the same medicine injection device and a nozzle attachment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  1 to 10 show a nozzle-exchange-type dental drug injector 1 according to an embodiment of the present invention. The drug injector 1 is detachably attached to a syringe 2 and a distal end portion of the syringe 2. It is comprised by the nozzle attachment 3 screwed. The nozzle attachment 3 of this embodiment is attached and fixed to the syringe tip by screwing it into the syringe 2 while rotating it in a predetermined direction up to a predetermined lock position. 1 to 3 and 10 illustrate a state in which the nozzle attachment 3 is fixed at the lock position.

  The syringe 2 includes a cylindrical body in which various dental drugs, for example, various drugs injected into the root canal and periodontal pockets, quasi-drugs, adhesives, fillers, and the like, and the cylindrical shape A tapered cylindrical nozzle portion 4 and a luer lock portion 5 are formed integrally with the tip of the body. A plunger (not shown) is fitted into the cylindrical body, and the medicine is sucked into the body through the nozzle portion 4 by the pull-in operation of the plunger, and the medicine in the body moves the nozzle portion 4 through the plunger pushing-in operation. It is discharged through. The syringe 2 can be made of transparent resin or glass. In addition, the outer diameter of the syringe 2 can be about 10 mm, and a full length can be about 5-10 cm.

  The nozzle part 4 and the luer lock part 5 are provided concentrically with the cylindrical body, and the luer lock part 5 is provided on the outer peripheral side of the nozzle part 4. The nozzle part 4 is extended toward the tip side from the luer lock part 5. The outer diameter of the luer lock portion 5 is the same as the outer diameter of the cylindrical body, and a gap is provided between the inner peripheral surface of the luer lock portion 5 and the outer peripheral surface of the nozzle portion 4. The outer peripheral surface of the nozzle portion 4 is a tapered surface that gradually decreases in diameter as it reaches the tip end in the axial direction. The inner peripheral surface of the luer lock portion 5 has a slightly larger diameter toward the tip end side in the axial direction.

  A female screw is provided on the inner peripheral surface of the luer lock portion 5. In the illustrated embodiment, the female screw is constituted by two threads 6a and 6b, but the female screw may be constituted by a single thread.

  The nozzle attachment 3 includes a cylindrical base that is externally fitted to the nozzle portion 4, a narrow-mouth nozzle 7 that is connected to the cylindrical base, and a flange 8 that is integrally formed on the outer peripheral portion of the cylindrical base. Yes. The narrow mouth nozzle 7 is bent in the illustrated embodiment, but may be configured in a straight cylinder shape. The nozzle attachment 3 is made of a thermoplastic resin mixed with an elastomer so as to have appropriate elasticity.

  On the outer periphery of the base end portion of the cylindrical base portion, an engagement piece 9 that is screwed into the female screw of the lock portion 5 is provided so as to project outward in the radial direction. In the illustrated embodiment, a pair (two) of the engagement pieces 9 are provided opposite to each other in the diametrical direction, and each engagement piece 9 is constituted by a protruding piece that is flat in the circumferential direction. Three or more engagement pieces 9 may be provided, and a plurality of engagement pieces 9 may be provided with their positions shifted in the axial direction. Each engagement piece 9 may be formed to be inclined in a somewhat spiral shape. As shown in FIG. 10, each engaging piece 9 has an axially proximal end side edge of one screw thread 6a in which the illustrated left end portion (tip portion in the predetermined direction) of the engaging piece 9 forms a female screw. To the lower end (axial base end side), and the right end portion (the base end portion in the predetermined direction) of the engagement piece 9 is an edge portion on the axial front end side of another screw thread 6b constituting a female screw. It is comprised so that it may contact from upper direction (axial direction front end side). When the nozzle attachment 3 is in the locked position, both ends of the engagement piece 9 are pressed relatively strongly against the screw threads 6a and 6b. However, the nozzle attachment 3 is pressed relatively weakly before the locked position or a gap is generated. The shape of the threads 6a, 6b can also be defined. Further, the axial dimension (thickness) of the engagement piece 9 and each thread 6a, 6b may be about 0.5 to 1.0 mm, and the engagement piece 9 and each thread 6a, 6b are slightly overlapped. Even if the dimension design is such that the end of the engagement piece 9 is appropriately deformed, a good engagement relationship is obtained.

  When the cylindrical base portion of the nozzle attachment 3 is in a locked position, the cylindrical throttle portion 10 is tightly fitted to the tip portion of the nozzle portion 4, and is connected to the throttle portion 10 in the axial direction and is in the locked position. And a cylindrical extension portion 11 that loosely fits on a portion other than the tip portion of the nozzle portion 4. The extension portion 11 is inserted into the lock portion 5, and the engagement piece 9 is provided at the axial base end portion of the extension portion 11. In the illustrated embodiment, a step portion is provided between the inner peripheral surface of the throttle portion 10 and the inner peripheral surface of the extension portion 11, but the diameter of the tip portion of the nozzle portion is slightly larger than the diameter other than the tip portion. If it is set as a diameter, the inside diameter of a throttle part and an extension part may be the same. Further, at the initial stage of screwing the nozzle attachment 3 into the distal end portion of the syringe 2, that is, immediately after the engagement piece 8 is engaged with the female screw of the lock portion 5, the distal end portion of the nozzle portion 4 is fitted into the throttle portion 10. The dimensions of each part are set so that the tip of the nozzle part 4 fits into the throttle part 10 as the nozzle attachment 3 is screwed relative to the lock part 5.

  Further, a seal surface 12 is provided on the inner surface of the tip of the cylindrical base of the nozzle attachment 3 so as to face the tip of the nozzle 4, and when the nozzle attachment 3 is in the locked position, the tip of the nozzle 4 is The seal surface 12 is pressed.

  A pair of first engaging portions 13 are provided on the outer peripheral surface of the distal end portion of the lock portion 5 at positions facing each other in the diametrical direction. Each first engagement portion 13 is provided in a recess 14 formed on the outer peripheral surface of the distal end portion of the lock portion 5, and the axial base end side edge portion 14 a of the recess 14 has the same gradient as the threads 6 a and 6 b. It is inclined. A pair of recesses 14 are also provided facing each other in the diameter direction. Each first engagement portion 13 is configured by a convex portion that protrudes in a hill shape radially outward as viewed from the axial direction.

  On the other hand, the flange 8 of the nozzle attachment 3 is provided with a protrusion 15 that protrudes from the vicinity of the outer peripheral edge thereof toward the proximal end side in the axial direction and is located on the outer periphery of the recess 14 of the lock portion 5. When the attachment 3 is rotated to the locked position, it contacts the leading edge portion 14b of the concave portion 14 in the predetermined direction, and further rotation in the predetermined direction is restricted. A second engaging portion 16 is provided on the inner peripheral portion of the protrusion 15. The second engaging portion 16 is a convex portion that protrudes in a hill shape inward in the radial direction when viewed from the axial direction. Instead of the protrusion 15, a cap that is fitted on the tip of the lock portion 5 may be provided on the flange 8, and the second engagement portion 16 may be provided on the inner peripheral surface of the cap.

  The minimum inner diameter of the second engagement portion 16 of the nozzle attachment 3 is larger than the diameter of the outer peripheral surface of the recess 14, but smaller than the maximum outer diameter of the first engagement portion 13. Therefore, when the nozzle attachment 3 is screwed into the distal end portion of the syringe 2, the protrusion 15 is slightly elastically deformed so that the second engagement portion 16 gets over the first engagement portion 13 and the second engagement portion 16. Is positioned between the first engagement portion 13 and the edge portion 14b, and this position becomes the lock position.

  According to the nozzle exchange type drug injector according to the present embodiment described above, in the process of assembling the nozzle attachment 3 in the lock position with respect to the syringe 2, it is between the outer peripheral surface of the nozzle portion 4 and the inner peripheral surface of the nozzle attachment 3. Since there is a gap between them and only the left and right end portions of the pair of engaging pieces 9 are engaged with the female screws of the lock portion 5, the frictional resistance to the rotating operation is small, and the nozzle attachment 3 can be smoothly attached and detached. The operation can be performed. On the other hand, when the nozzle attachment 3 is assembled at the lock position, the tip end of the nozzle portion 4 is in axial contact with the seal surface 12 of the nozzle attachment 3, and the tip end of the nozzle portion 4 is the throttle portion of the nozzle attachment 3. 10 and the left and right end portions of the pair of engaging pieces 9 are engaged with the female screw of the lock portion 5 either toward the distal end side in the axial direction or toward the proximal end side, As a result, the nozzle attachment 3 is stably fixed to the syringe 2 without backlash in the axial direction, and the rotation of the nozzle attachment 3 in the loosening direction is in the circumferential direction of the first and second engaging portions 13 and 16. Therefore, the nozzle attachment 3 is hardly unintentionally loosened, and the medicine injection operation to a proper place for medical practice can be performed smoothly and accurately. .

  The present invention is not limited to the above-described embodiment, and can be appropriately changed in design. For example, the engagement piece of the nozzle attachment can be formed by a thread that forms a male screw. Moreover, the spiral length of the screw thread of the lock portion may not be so long, and the nozzle attachment can be positioned at the lock position only by rotating about a half turn. In addition, the first engagement portion may be formed on the front end surface or the inner peripheral surface of the lock portion, and the position where the second engagement portion is provided corresponding to this may be appropriate. In addition, either one of the first and second engaging portions can be constituted by a concave portion, and in this case, a position where the first engaging portion and the second engaging portion are fitted is set as a lock position. it can.

  In addition, the drug injector, syringe, and drug injector replacement nozzle (nozzle attachment) shown in the drawings of the present application can be changed to a design registration application. The replacement nozzle can be grasped as a partial design characterized by only the outer shape of the flange 8 and the protrusion, as well as the whole design, and the outer shape of the extension portion and the engagement piece. It can also be grasped as a partial design characterized only by the shape, and further can be grasped as a partial design characterized only by the outer shapes of the flange 8, the protrusion, the extension, and the engagement piece. The syringe can be grasped as a partial design characterized only by the outer shape of the tip (that is, the nozzle part and the luer lock part) as well as the whole design.

DESCRIPTION OF SYMBOLS 1 Nozzle exchange type chemical | medical agent injector 2 Syringe 3 Nozzle attachment 4 Nozzle part 5 Lock part 6a, 6b Screw thread 9 Engagement piece 10 Restriction part 11 Extension part 12 Seal surface 13 First engagement part 15 Protrusion 16 Second Engagement part

Claims (4)

A syringe having a nozzle part for discharging a medicine filled therein, and a nozzle attachment that is replaceably fitted to the nozzle part of the syringe, the syringe being provided around the nozzle part In the nozzle replaceable drug injector, further comprising a cylindrical lock part, wherein the nozzle attachment is fixed to the lock part by being rotated in a predetermined direction to a predetermined lock position with respect to the lock part.
The lock portion includes a first engagement portion at a predetermined position in a circumferential direction, and the nozzle attachment inhibits reverse rotation of the nozzle attachment with respect to the lock portion when the nozzle attachment is rotated in a predetermined direction to the lock position. A second engaging portion that engages with the first engaging portion in the circumferential direction ;
The nozzle portion is configured in a tapered tube shape, and the nozzle attachment is engaged with a male screw in which an engagement piece provided on an outer peripheral surface thereof is formed by one or a plurality of threads provided on an inner peripheral surface of the lock portion. The nozzle attachment is screwed to the lock portion, and the nozzle attachment is connected to the throttle portion in which the tip end portion of the nozzle portion is tightly fitted when rotated to the lock position, and to the throttle portion in the axial direction. And an extension portion that loosely fits to a portion other than the tip portion of the nozzle portion when rotated to the lock position, and the tip portion of the nozzle portion attaches the nozzle attachment to the nozzle portion. By rotating in a predetermined direction up to the lock position and screwed into the throttle part and tightly fitted to the throttle part,
Immediately after the engagement piece is engaged with the male screw of the lock portion, the tip end portion of the nozzle portion is not fitted into the throttle portion, and the nozzle attachment is screwed with respect to the lock portion. The nozzle replaceable drug injector is configured so that the tip of the nozzle portion fits into the throttle portion as the nozzle moves . 2. The nozzle replaceable drug injector according to claim 1 , wherein the first engagement portion is a convex portion provided on an outer peripheral surface of the lock portion and protruding outward in a radial direction when viewed from the axial direction, and the nozzle attachment. Comprises a protrusion located on the outer periphery of the distal end of the lock part, and the second engaging part is a convex part provided on the inner peripheral part of the protrusion and protruding inward in the radial direction when viewed from the axial direction. A nozzle replaceable drug injector. In the nozzle replaceable drug infusion device according to claim 1 or 2, when the nozzle attachment is in the locked position even without low, either the distal end portion in the predetermined direction of the engaging piece constituting the female screw The proximal end of the engagement piece in the predetermined direction is in contact with the axial distal end of one of the threads constituting the female screw. A nozzle-replaceable drug injector characterized by contact. The nozzle exchange type medicine injection device according to any one of claims 1 to 3 , wherein the nozzle attachment is in contact with the tip of the nozzle portion in the axial direction when the nozzle attachment is rotated to the lock position. A nozzle-replaceable drug injector characterized by comprising:

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