JP2018089070A - Needle assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a needle assembly having a novel structure capable of more reliably restricting the movement of a needle hub toward a proximal end side with respect to a housing without providing a protrusion protruding inward with respect to the housing. SOLUTION: In a needle assembly 10, a locking hole 62 that opens in a housing 16 is provided, while a locking protrusion 36 that elastically protrudes from a needle hub 14 is provided, and a hollow needle 12 is provided. The locking protrusion 36 is locked in the locking hole 62 at the retracted position into the housing 16 to prevent the hollow needle 12 from re-protruding from the housing 16 and to the housing 16 of the hollow needle 12. The inner surface of the housing 16 on the front side in the axial direction with respect to the locking hole 62 of the housing 16 with which the locking protrusion 36 slides toward the locking hole 62 is located on the rear side in the axial direction of the locking hole 62 in the housing 16. The guide surface 68 is located on the outer peripheral side of the inner surface and guides the locking protrusion 36 into the locking hole 62. [Selection diagram] Fig. 3

Description

  The present invention relates to a needle assembly that is punctured into the skin during blood collection, blood transfusion, infusion, and the like, and is housed and protected in a housing after use.

  Conventionally, a needle assembly used when performing infusion, blood collection, or hemodialysis is known. The needle assembly includes a hollow needle, and a proximal end of the hollow needle is fixed to a needle hub. When such a needle assembly is punctured into a blood vessel of a patient, infusion, blood collection, and hemodialysis are performed through an external conduit such as a cannula connected to a needle hub.

  Some needle assemblies include a housing that protects the needle tip after use for the purpose of preventing erroneous puncture and reuse, or facilitating disposal. For example, as a needle assembly provided with such a housing, there is one described in US Pat. No. 5,776,679 (Patent Document 1).

  That is, the needle assembly described in Patent Document 1 includes a hollow needle, a needle hub that fixes and supports the hollow needle, and a substantially cylindrical housing that is externally inserted in the needle hub so as to be movable in the axial direction. ing. In the initial state before use, the needle hub and the housing are engaged with each other, so that the urging member (spring) provided in the housing is compressed and the hollow needle protrudes from the housing. Is held in. In this state, the hollow needle is punctured into the patient's blood vessel, and then the engagement between the needle hub and the housing is released by an external operation, and the hollow needle and the needle hub are moved relative to the housing by the biasing force of the spring. By moving to the end side, the hollow needle can be safely discarded while being accommodated in the housing.

  In the needle assembly described in Patent Document 1, the proximal movement of the needle hub relative to the housing is caused by the contact protrusion (40) projecting outward at the axially intermediate portion of the needle hub. It was regulated by entering the opening (48) at the base end of the portion 12) and coming into contact with the engaging shoulder (47). That is, the inner diameter dimension of the main body is substantially constant over the entire length.

  However, since the inner diameter of the main body is substantially constant over the entire length, the contact protrusion of the needle hub is not locked to the engagement shoulder, and the hollow needle and the needle hub are There was a risk of jumping out of the main body.

  Although it is conceivable to provide a protrusion projecting inwardly on the inner surface of the main body portion, if such a structure is adopted, the structure of the housing mold becomes complicated, and the production efficiency may be reduced.

US Pat. No. 5,777,679

  The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is to move the needle hub toward the proximal side with respect to the housing without providing a protrusion protruding inward with respect to the housing. It is an object of the present invention to provide a needle assembly having a novel structure that can be reliably regulated.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible.

  According to a first aspect of the present invention, a needle hub of a hollow needle is inserted in a cylindrical housing so as to be movable in an axial direction, and the hollow needle protrudes from the housing to a use position. An engagement mechanism for positioning the needle hub and an urging means for urging the hollow needle in the retracting direction with respect to the housing are provided. When the engagement mechanism is released, the hollow needle is moved to the housing. In the needle assembly that is retracted and accommodated, a locking hole that opens on the inner surface of the housing is provided, while a locking protrusion that elastically protrudes from the needle hub toward the inner surface of the housing is provided. And the locking projection is locked in the locking hole at the retracted position of the hollow needle into the housing, so that the hollow needle is prevented from re-projecting from the housing. , As the hollow needle is retracted into the housing. The inner surface of the housing in the axial direction front side with respect to the locking hole is slidably contacted with the locking projection toward the locking hole at least at the opening edge of the locking hole. It is characterized by being a guide surface that is positioned on the outer peripheral side of the inner surface on the axially rear side of the hole and guides the locking projection into the locking hole.

  According to the needle assembly structured according to this aspect, the locking projection protrudes elastically from the needle hub toward the inner surface of the housing, and when the hollow needle is pulled into the housing, the locking projection The protrusion is elastically deformed to the inner peripheral side, and moves to the proximal end side while sliding on the inner surface of the housing. The locking protrusion is restored and deformed by reaching the locking hole provided in the housing, and the locking protrusion is locked in the locking hole, so that the housing of the hollow needle Re-protrusion from is prevented. In particular, the inner surface on the axially front side of the locking hole is positioned on the outer peripheral side of the inner surface on the rearward side in the axial direction of the locking hole and serves as a guide surface that guides the locking projection into the locking hole. Therefore, the locking protrusion is restored and deformed from the locking hole to the outer peripheral side before reaching the locking hole, and the hollow needle and the needle hub are vigorously moved to the proximal end side by the biasing force of the biasing member. Even so, the locking of the locking protrusion to the locking hole can be achieved more reliably.

  According to a second aspect of the present invention, there is provided the needle assembly according to the first aspect, wherein the locking projection is slidably contacted with the housing at an axially front side of the locking hole. The guide surface is configured such that the inner surface has a larger inner diameter surface than the inner surface on the rear side in the axial direction of the locking hole.

  According to the needle assembly structured according to this aspect, the inner diameter of the inner surface on the axially front side of the locking hole in the housing is made larger than the inner diameter of the inner surface on the axially rear side of the locking hole. Therefore, before the locking projection reaches the locking hole, the locking projection can be restored and deformed more reliably to the outer peripheral side than the locking hole. In particular, when configuring the guide surface, for example, the thickness of the peripheral wall portion of the housing is not reduced, so that the strength of the housing can be sufficiently ensured.

  According to a third aspect of the present invention, there is provided the needle assembly according to the second aspect, wherein the locking protrusion is slidably contacted with the housing at an axially front side of the locking hole. The guide surface is an inclined surface whose inner diameter gradually increases toward the rear side in the axial direction where the locking hole is located.

  According to the needle assembly having the structure according to this aspect, since the guide surface is an inclined surface whose inner diameter dimension gradually increases toward the rear side in the axial direction, the restoring deformation of the locking projection is smoothly generated. Thus, the operation of retracting the hollow needle into the housing by the user can be satisfactorily achieved.

  A fourth aspect of the present invention is the needle assembly according to the second or third aspect, wherein the guide surface of the peripheral wall portion of the housing is substantially perpendicular to the retracting direction of the hollow needle. A through hole penetrating in the width direction is provided extending on the guide surface.

  According to the needle assembly structured according to this aspect, the peripheral wall portion of the housing is provided with a through hole extending through the guide surface in the width direction of the guide surface. When manufacturing by molding, the mold can be punched through the through-hole, and the manufacturing efficiency of the housing and thus the needle assembly can be improved. In addition, by appropriately adjusting the size of the through hole, it is possible to visually recognize the locking state of the locking protrusion to the locking hole through the through hole.

  According to a fifth aspect of the present invention, there is provided the needle assembly according to any one of the first to fourth aspects, wherein in the housing, the locking assembly is located on an axially front side of the locking hole. The guide surface with which the protrusion is slidably contacted is configured by a deformable flexible wall, and the locking protrusion that slides against the guide surface and moves toward the locking hole is flexible. By being pressed against the wall portion, the flexible wall portion has a diameter-expanded surface that deforms outward.

  According to the needle assembly structured according to this aspect, the locking projection is pressed against the guide surface of the flexible wall, so that the flexible wall is deformed outward, and the guide surface (expanded). The inner diameter dimension of the (diameter surface) is made larger than the inner diameter dimension of the inner surface on the axially rear side of the locking hole. As a result, the locking projection is restored and deformed from the locking hole to the outer peripheral side before reaching the locking hole, and the locking of the locking projection to the locking hole can be achieved more reliably.

  According to a sixth aspect of the present invention, in the needle assembly according to the fifth aspect, the peripheral wall portion of the housing is thinned at a portion constituting the guide surface, whereby the flexible wall portion is configured. It is what.

  According to the needle assembly having the structure according to this aspect, the flexible wall portion can be configured with a simple structure because the portion constituting the guide surface in the peripheral wall portion of the housing is made thin. A flexible wall portion may be formed to improve the manufacturing efficiency of the housing and thus the needle assembly.

  According to a seventh aspect of the present invention, there is provided the needle assembly according to any one of the first to sixth aspects, wherein in the housing, a portion positioned axially forward of the locking hole and the axial direction A portion located on the rear side is constituted by a single part integrally molded.

  According to the needle assembly having the structure according to the present aspect, the part located on the axially front side and the part located on the axially rear side of the locking hole are formed of a single part integrally formed. Therefore, the housing can be formed with a small number of parts, and for example, the entire housing can be constituted by a single part. In particular, in Patent Document 1, for example, a mechanism that restricts the movement of the hollow needle and the needle hub by providing a protrusion on the inner surface of the housing is employed, so the housing is composed of two parts. Then, compared with such a structure, the number of parts can be reduced, and the manufacturing efficiency of the housing, and thus the needle assembly can be improved.

  An eighth aspect of the present invention is the needle assembly according to any one of the first to seventh aspects, wherein in the needle hub, a pair of elastic projecting pieces that incline in an axial direction and extend outward. And the locking projections are provided at the tip portions of the elastic projection pieces, while the peripheral wall portion of the housing is positioned farther toward the tip side in the axial direction than the locking holes. A positioning hole is provided, and the engagement mechanism that holds the hollow needle in the use position protruding from the housing by the engaging action of the locking protrusion with respect to the positioning hole is configured. is there.

  According to the needle assembly having the structure according to this aspect, the hollow needle is held at the use position where the hollow needle protrudes from the housing by the engaging action of the pair of locking projections and the pair of positioning holes. That is, in order to move the hollow needle from the use position to the accommodation position in the housing, it is necessary to release the engagement between the pair of locking protrusions and the positioning holes. Compared with the case where only one positioning hole is provided, it is effectively prevented that the engagement between the locking projection and the positioning hole is unintentionally released and the hollow needle is accommodated in the housing. Thus, the hollow needle can be held more stably at the use position.

  According to a ninth aspect of the present invention, in the needle assembly according to the eighth aspect, the positioning hole has a pressing protrusion that faces the outer opening of the positioning hole while passing through the peripheral wall portion of the housing. A flexible piece is provided on the housing, and the locking protrusion provided on the needle hub and engaged with the positioning hole is pushed by the pressing protrusion from the outer peripheral side of the housing. The engagement of the stop protrusion with the positioning hole is released.

  According to the needle assembly structured according to this aspect, the engagement between the locking protrusion and the positioning hole is released by pushing the locking protrusion into the inner peripheral side with the pressing protrusion provided in the housing. . In particular, since the needle assembly of this aspect includes a biasing means that biases the hollow needle in the retracting direction, the hollow needle is automatically released by releasing the engagement between the locking projection and the positioning hole. It will be pulled into the housing, allowing one-touch operation.

  According to the needle assembly having the structure according to the present invention, when the locking projection is introduced into the locking hole, the inner surface (guide surface) on the axially front side of the locking hole is rearward in the axial direction. Since the protrusion is not provided on the inner surface of the housing, the locking protrusion is more securely locked in the locking hole, so that the hollow needle and the needle hub Jumping out of the housing can be effectively prevented.

The top view which shows the needle | hook assembly as a 1st Embodiment of this invention in a use condition. II-II sectional drawing in FIG. III-III sectional drawing in FIG. The top view which shows the needle assembly shown by FIG. 1 in the accommodation state of a hollow needle. VV sectional drawing in FIG. VI-VI sectional drawing in FIG. The front view which shows the needle | hook assembly as a 2nd Embodiment of this invention in a use condition. FIG. 8 is a plan view of the needle assembly shown in FIG. 7. IX-IX sectional drawing in FIG. The front view which shows the needle assembly shown by FIG. 7 in the accommodation state of a hollow needle. FIG. 11 is a plan view of the needle assembly shown in FIG. 10. XII-XII sectional drawing in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the needle | hook assembly 10 as the 1st Embodiment of this invention is shown by the use condition by FIGS. 1-3. The needle assembly 10 includes a hollow needle 12 and a needle hub 14 that fixes and supports the proximal end side of the hollow needle 12. The hollow needle 12 and the needle hub 14 are pivoted with respect to a cylindrical housing 16. Interpolated to be movable in the direction. As shown in FIGS. 1 to 3, in use, the needle tip 18 of the hollow needle 12 protrudes from the housing 16 toward the distal end side, and after use, the hollow needle 12 and the needle hub 14 are in the housing 16. On the other hand, the needle tip 18 of the hollow needle 12 is accommodated in the housing 16 to be protected by moving to the proximal end side. In the following description, the axial direction refers to the left-right direction in FIG. 1 that is the needle axial direction of the hollow needle 12. Further, the distal end side and the front side refer to the left side in FIG. 1 that is the needle tip 18 side of the hollow needle 12, while the proximal end side and the rear side refer to the external conduit 20 such as a cannula with respect to the needle hub 14. The right side in FIG. 1 which is a connected side is said. Furthermore, the vertical direction refers to the vertical direction in FIG. 2, and the horizontal direction refers to the downward direction in FIG.

  More specifically, the hollow needle 12 is made of metal, for example, and is formed of stainless steel or the like. The needle tip 18 of the hollow needle 12 is tapered and has a sharp shape. A through hole may be formed in the needle tip 18 of the hollow needle 12 so that blood can easily flow into the hollow needle 12.

  The needle hub 14 has a substantially cylindrical shape as a whole, and is formed of a hard synthetic resin or the like. An annular positioning protrusion 22 that protrudes toward the inner peripheral side is provided on the inner peripheral surface in the axially intermediate portion of the needle hub 14. The proximal end of the hollow needle 12 is inserted from the distal end opening of the needle hub 14 and the proximal end of the hollow needle 12 and the positioning protrusion 22 come into contact with each other, whereby the proximal end of the hollow needle 12 is positioned. It has become so. Then, if necessary, the hollow needle 12 and the needle hub 14 are fixed to each other by means such as adhesion, so that the hollow needle 12 is fixedly supported at the tip of the needle hub 14.

  On the other hand, the proximal end portion of the needle hub 14 is provided with a large diameter portion 24 having an increased inner diameter, and an external pipe line 20 such as a cannula is inserted from the proximal end side opening portion of the large diameter portion 24. Yes. Further, the outer pipe line 20 is connected to the proximal end of the needle hub 14 by performing a treatment such as adhesion as necessary. The hollow needle 12, the needle hub 14, and the inner holes of the external pipe line 20 constitute a fluid flow path 26 through which a drug solution and blood flow when performing infusion and blood collection.

  Further, an annular protrusion 28 that protrudes to the outer peripheral side is provided on the outer peripheral surface in the axially intermediate portion of the needle hub 14. In the needle hub 14, the outer peripheral surface on the base end side with respect to the annular protrusion 28 has a vertical dimension larger than the horizontal dimension. That is, on the outer peripheral surface of the needle hub 14, plate-like protruding plate portions 30, 30 protruding outward are formed on both sides in the up-down direction, and the vertical dimension at the position where these protruding plate portions 30, 30 are formed. However, the outer diameter of the annular protrusion 28 is substantially equal. In other words, on the outer peripheral surface of the needle hub 14, projecting plate portions 30, 30 extending continuously from the annular projecting portion 28 to the proximal end side are formed on both sides in the up-down direction.

  Further, steps 32, 32 are formed on the outer surfaces of the protruding plate portions 30, 30, and in the protruding plate portions 30, 30, the thickness dimension (vertical direction size) on the base end side with respect to the steps 32, 32. However, it is made larger than the thickness dimension of the front end side.

  On the other hand, on the outer peripheral surface of the needle hub 14, a pair of elastic protrusions 34, 34 extending outward are provided on the base end side of the annular protrusion 28. These elastic protrusions 34, 34 are inclined in the axial direction from the outer peripheral surface of the needle hub 14 on both sides in the left-right direction, and extend to the tip side. Further, the protruding tip protrudes outward in the left-right direction. Stop projections 36 are provided. The elastic protrusions 34 and 34 including the locking protrusions 36 and 36 can be elastically deformed in the direction perpendicular to the axis (left and right direction).

  The housing 16 has a substantially cylindrical shape with a peripheral wall portion 38 as a whole, and is formed as an integrally molded product of hard synthetic resin or the like. The distal end portion of the housing 16 has a cylindrical shape having a smaller diameter than the intermediate portion and the proximal end portion in the axial direction. The distal end portion of the housing 16 has an insertion hole 40 at the center and has an annular shape protruding toward the inner peripheral side. A front wall portion 42 is formed.

  On the other hand, from the axial direction intermediate part of the housing 16 to the base end part, it has a horizontally long shape in which the horizontal dimension is larger than the vertical dimension. In this embodiment, the housing 16 has a substantially elliptical cylindrical shape. . A peripheral wall portion 38 of the housing 16 is formed by the peripheral walls of the cylindrical portion on the distal end side and the elliptical cylindrical portion on the proximal end side.

  On the inner surface 44 of the peripheral wall portion 38 of the housing 16, steps 46, 46 are provided on both sides in the vertical direction of the axially intermediate portion, and the thickness dimension of the peripheral wall portion 38 on the tip side of the step 46, 46. The (vertical dimension) is made larger than the thickness dimension of the peripheral wall 38 on the base end side with respect to the steps 46 and 46.

  In the base end portion of the housing 16, rectangular through windows 48 that penetrate the peripheral wall portion 38 are formed on both sides in the up-down direction. Then, elastic tongue pieces 50, 50 projecting toward the base end side are integrally formed from the inner peripheral edge portion on the distal end side of these through windows 48, 48. The elastic tongue pieces 50 and 50 are not connected to the peripheral wall portion 38 on the three sides, and elastically deform in the vertical direction starting from the protruding base end (the inner peripheral edge portion on the distal end side of the through windows 48 and 48). It is possible. Further, engaging claws 52 and 52 projecting toward the inner peripheral side are formed at projecting tips (base ends in the axial direction) of the elastic tongue pieces 50 and 50. When the hollow needle 12 and the needle hub 14 are not assembled to the housing 16 and the housing 16 is in a single product state, the vertical separation distance between the engaging claws 52 and 52 is the base end portion of the needle hub 14 (protrusion). It is made smaller than the vertical dimension in the base portion side portions of the plate portions 30, 30, more specifically, the steps 32, 32 in the protruding plate portions 30, 30 of the needle hub 14. Further, it is substantially equal to the vertical dimension on the tip side (the outer diameter dimension of the annular protrusion 28).

  Further, in the peripheral wall portion 38 of the housing 16, positioning holes 54, 54 penetrating the peripheral wall portion 38 are formed in axial intermediate portions on both sides in the left-right direction. In the inner surface 44 of the housing 16, the lateral width dimension of the portion adjacent to the base end side of the positioning holes 54, 54 is the maximum lateral width of the locking projections 36, 36 in the use state shown in FIG. It is smaller than the dimensions.

  In the peripheral wall portion 38 of the housing 16, a pair of flexible pieces 56, 56 that incline in the axial direction and extend toward the distal end side are provided on both sides in the left-right direction on the outer peripheral surface closer to the base end side than the positioning holes 54, 54. Is formed. These flexible pieces 56, 56 can be bent and deformed inward in the left-right direction, and in this embodiment, elastic deformation is possible.

  Furthermore, pressing protrusions 58 and 58 are formed at the tips of the flexible pieces 56 and 56 so as to protrude inward in the left-right direction. These pressing protrusions 58 and 58 are formed in a size smaller than the positioning holes 54 and 54, and are located outside the positions facing the positioning holes 54 and 54, that is, from the outer openings 60 and 60 of the positioning holes 54 and 54. It is provided at a position separated by a predetermined distance.

  On the other hand, in the peripheral wall portion 38 of the housing 16, a pair of locking holes 62, 62 that open to the inner surface 44 are located at the base end portions on both sides in the left-right direction, that is, at positions farther to the base end side than the flexible pieces 56, 56. In this embodiment, the locking holes 62 and 62 are formed so as to penetrate the peripheral wall portion 38. In particular, in the present embodiment, the locking holes 62 and 62 are substantially rectangular, and the inner surfaces of the locking holes 62 and 62 on the proximal end side gradually incline toward the outer peripheral side toward the proximal end side. The inclined surfaces 64 and 64 are used.

  Here, on both sides in the left-right direction of the housing 16, the peripheral wall portion 38 is gradually expanded toward the base end side on the distal end side (axially front side) with respect to the locking holes 62, 62. That is, on both sides in the left and right direction of the housing 16, inclined wall portions 66 and 66 that gradually incline toward the outer peripheral side toward the base end side are provided on the base end side with respect to the flexible pieces 56 and 56. The inner wall 44 of the housing 16 is formed so that the inner surfaces of the inclined wall portions 66 and 66 gradually increase in inner diameter toward the base end side (an elliptical shape which is a transverse section of the housing 16). The distances from the center of the inclined surfaces 68 and 68 are increased. Further, the locking holes 62, 62 are located adjacent to the base end sides of the inclined wall portions 66, 66. Thereby, on both sides in the left-right direction of the housing 16, the inner surfaces (inclined surfaces 68, 68) closer to the front end side (axially front side) than the locking holes 62, 62 extend over the predetermined axial distance. It is located on the outer peripheral side with respect to the inner surface on the base end side (axially rear side) with respect to 62 and 62. In other words, the inclined surfaces 68, 68 positioned on the distal end side of the locking holes 62, 62 have a larger inner diameter than the inner surface in the left-right direction among the inner surfaces positioned on the proximal end side of the locking holes 62, 62. ing.

  And the through-holes 70 and 70 which penetrate in the up-down direction which is the width direction of the inclined surfaces 68 and 68 are formed in the inner side (left-right direction inner side) of the inclined wall parts 66 and 66 in the surrounding wall part 38, The inclined surfaces 68 and 68 constitute the outer peripheral side surface of the inner surface of the through holes 70 and 70. That is, the through holes 70 and 70 are formed to extend on the inclined surfaces 68 and 68 in the width direction of the inclined surfaces 68 and 68. The through holes 70 and 70 are triangular in plan view, and the opening widths (lateral widths) of the through holes 70 and 70 are gradually increased toward the base end side. The through holes 70 and 70 communicate with the locking holes 62 and 62 in the axial direction on both sides in the left and right direction of the housing 16.

  In addition, a wing-like portion 72 is attached to the distal end portion of the housing 16 of the present embodiment. In other words, the wing-like portion 72 is configured to include a cylindrical portion 74 and wing bodies 76, 76 protruding from the cylindrical portion 74 on both sides in the left-right direction, and the cylindrical portion 74 is attached to the distal end portion of the housing 16. The wing-like portion 72 is attached to the housing 16 by being fitted. A positioning convex portion 78 extending toward the distal end side is provided on the upper side of the housing 16, and a positioning concave portion 80 opening on the proximal end side is provided above the cylindrical portion 74 in the wing-like portion 72. The wing-like portion 72 is positioned in the circumferential direction with respect to the housing 16 by inserting the positioning convex portion 78 into the positioning concave portion 80.

  The needle assembly 10 of the present embodiment is configured by inserting the hollow needle 12 and the needle hub 14 into the housing 16 having the above-described structure and assembling it. That is, the hollow needle 12 fixedly supported by the needle hub 14 is inserted from the proximal end side opening 82 of the housing 16 and is provided on the front wall portion 42 of the housing 16 in the use state shown in FIG. The distal end of the needle hub 14 and the hollow needle 12 protrude from the distal end of the housing 16 through the insertion hole 40.

  Between the needle hub 14 and the housing 16, a coil spring 84 is provided as an urging means for urging the hollow needle 12 and the needle hub 14 toward the proximal end side in the retracting direction into the housing 16. . That is, a coil spring 84 is extrapolated to the distal end portion of the needle hub 14, the proximal end of the coil spring 84 is fixed to the annular protrusion 28 of the needle hub 14, and the distal end of the coil spring 84 is the housing. It is fixed to 16 front wall portions 42. In the use state shown in FIG. 1 and the like, the coil spring 84 is disposed in a compressed state between the axial direction of the annular protrusion 28 and the front wall portion 42, and the coil spring 84 is elastic. The hollow needle 12 and the needle hub 14 are urged to the proximal end side with respect to the housing 16 by a strong restoring force.

  In the assembled state of the housing 16 and the needle hub 14, the locking protrusions 36 and 36 provided on the needle hub 14 elastically protrude toward the inner surface 44 of the housing 16 and are provided on the housing 16. It protrudes outward through the positioning holes 54, 54. Then, the locking projections 36 and 36 and the inner peripheral edge of the proximal end side of the positioning holes 54 and 54 come into contact with each other, whereby the locking projections 36 and 36 are locked in the positioning holes 54 and 54. Yes. Thereby, in the use state shown by FIG. 1 etc., the displacement to the base end side with respect to the housing 16 of the hollow needle 12 and the needle hub 14 is controlled. Accordingly, an engagement mechanism is configured to position and hold the hollow needle 12 and the needle hub 14 at the use positions protruding from the housing 16 by the engaging action of the locking projections 36 and 36 with respect to the positioning holes 54 and 54. . Further, the steps 46 and 46 provided on both sides in the vertical direction of the inner surface 44 of the housing 16 and the steps 32 and 32 provided on both sides in the vertical direction of the needle hub 14 are engaged in the axial direction, so that the hollow needle 12 and Displacement of the needle hub 14 toward the distal end side with respect to the housing 16 is restricted.

  Further, in this assembled state, the vertical separation distance between the engaging claws 52, 52 provided in the housing 16 is smaller than the vertical dimension of the proximal end portion of the needle hub 14. Elastic tongues 50, 50 provided on both sides of the base end portion in the up-down direction are pressed outwardly by the base end portion of the needle hub 14 and elastically spread. Thereby, an elastic restoring force to the inner peripheral side acts on the elastic tongue pieces 50, 50, and the elastic tongue pieces 50, 50 and the engaging claws 52, 52 are urged to the inner peripheral side, The displacement of the elastic tongue pieces 50, 50 and the engaging claws 52, 52 toward the inner peripheral side is limited by the engagement of the engaging claws 52, 52 and the outer peripheral surface of the needle hub 14.

  The needle assembly 10 having the above-described structure allows blood and chemicals to flow through the fluid flow path 26 by puncturing the hollow needle 12 into the patient's skin, and blood is collected and infused. Then, after blood collection or infusion, the needle tip 18 of the hollow needle 12 is moved to the housing 16 by moving the hollow needle 12 and the needle hub 14 to the proximal end side with respect to the housing 16 as shown in FIGS. Housed and protected within, needle assembly 10 can be safely discarded.

  That is, after blood collection or infusion is completed, the locking protrusions 36 that project the pressing protrusions 58 and 58 from the positioning holes 54 and 54 by pressing the flexible pieces 56 and 56 provided on the housing 16 inward in the left-right direction. , 36, the elastic protrusions 34, 34 including the locking protrusions 36, 36 are elastically deformed to the inner peripheral side. Accordingly, the engagement of the engagement mechanism constituted by the locking projections 36 and 36 and the positioning holes 54 and 54 is released, and the hollow needle 12 and the needle hub 14 are moved to the housing 16 according to the urging force of the coil spring 84. The hollow needle 12 and the needle hub 14 are retracted into the housing 16 and accommodated. At that time, an elastic restoring force to the outer peripheral side acts on the locking projections 36, 36, and is slid to the base end side while abutting against the inner surface 44 of the housing 16.

  Then, when the locking projections 36 and 36 reach the locking holes 62 and 62 provided in the base end portion of the housing 16, the elastic protruding pieces 34 and 34 are restored and deformed to the outer peripheral side, and the locking projections 36 and 36 enter the locking holes 62 and 62, and the locking protrusions 36 and 36 come into contact with the inclined surfaces 64 and 64, which are the inner surfaces of the locking holes 62 and 62, on the proximal end side. The portions 36 and 36 are locked in the locking holes 62 and 62. Thereby, in the retracted position of the hollow needle 12 and the needle hub 14 shown in FIGS. 4 to 6 into the housing 16, the movement of the hollow needle 12 and the needle hub 14 to the proximal end side with respect to the housing 16 is restricted.

  Further, in the accommodated state (retracted state), the engaging claws 52 and 52 of the housing 16 pass through the steps 32 and 32 provided on the outer surface of the needle hub 14, thereby being restored and deformed to the inner peripheral side. As a result, as shown in FIG. 5, the engaging claws 52, 52 come into contact with the outer surface of the protruding plate portions 30, 30 of the needle hub 14 on the front end side with respect to the steps 32, 32. 52 and the steps 32 and 32 are engaged in the axial direction, so that the movement of the hollow needle 12 and the needle hub 14 relative to the housing 16 to the distal end side is restricted, and the re-projection of the hollow needle 12 from the housing 16 is prevented. It has come to be.

  Here, when the locking protrusions 36 and 36 move to the proximal side while sliding on the inner surface 44 of the housing 16 as the hollow needle 12 and the needle hub 14 are pulled into the housing 16, the inner surface 44 of the housing 16. Of these, the inner surfaces of the inclined wall portions 66, 66 are inclined surfaces 68, 68 that gradually incline toward the outer peripheral side toward the base end side, so that the locking projections 36, 36 are the inclined surfaces 68, 68. When passing through 68, it gradually moves to the base end side while being restored and deformed to the outer peripheral side. Since the inner diameter on the distal end side (inclined surfaces 68, 68) is larger in the left-right direction than the inner surface on the base end side than the locking holes 62, 62, the locking projection Prior to reaching the locking holes 62, 62, 36, 36 is made larger in the left-right dimension than the left-right inner diameter dimension on the inner surface on the proximal side of the locking holes 62, 62. Accordingly, the locking projections 36 and 36 can be more reliably guided into the locking holes 62 and 62. In this embodiment, the locking projections 36 and 36 are connected to the locking holes 62 and 62. A guide surface for guiding to 62 is constituted by inclined surfaces 68, 68. By adopting such inclined surfaces (guide surfaces) 68, 68, even if the hollow needle 12 and the needle hub 14 move to the proximal side with respect to the housing 16 according to the urging force of the coil spring 84, the locking protrusion The portions 36, 36 are more securely locked in the locking holes 62, 62, and for example, the possibility that the needle hub 14 comes out of the housing 16 without restricting the movement of the needle hub 14 toward the proximal end side is avoided. Can be done.

  As described above, the inner surfaces of the locking holes 62, 62 on the distal end side are inclined surfaces 68, 68 that gradually incline toward the outer peripheral side toward the proximal end side. However, in this embodiment, the engaging claws 52, 52 and the steps 32, 32 are engaged in the axial direction. Thus, the movement of the hollow needle 12 and the needle hub 14 toward the distal end side with respect to the housing 16 is restricted. As a result, the hollow needle 12 and the needle hub 14 cannot be displaced not only to the proximal end side but also to the distal end side with respect to the housing 16, and the housing state of the hollow needle 12 in the housing 16 is stabilized. Can be maintained.

  In the needle assembly 10 configured as described above, the movement of the hollow needle 12 and the needle hub 14 toward the base end side with respect to the housing 16 is provided with a protrusion on the inner surface of the housing as described in Patent Document 1. The locking projections 36, 36 provided on the needle hub 14 are controlled by being locked in the locking holes 62, 62 provided in the peripheral wall 38 of the housing 16. Therefore, it is avoided that the diameter of the proximal end portion of the needle hub 14 and the outer conduit 20 connected to the proximal end portion of the needle hub 14 is reduced, and blood or a chemical solution through the fluid flow path 26 is avoided. Can be realized stably.

  Further, since the elastic protrusions 34 and 34 projecting outward from the needle hub 14 are elastically deformed inward in the left-right direction when moving inside the housing 16 toward the proximal end, the needle hub 14 and the housing 16. Thus, the increase in size of the needle assembly 10 can be effectively prevented.

  In addition, since the inclined wall portions 66 and 66 constituting the inclined surfaces (guide surfaces) 68 and 68 of the present embodiment have substantially the same thickness as the other portions in the peripheral wall portion 38 of the housing 16, For example, it is possible to avoid a decrease in strength at the positions where the inclined surfaces (guide surfaces) 68 and 68 are formed. Furthermore, since the through holes 70 and 70 penetrating in the vertical direction are formed inside the inclined wall portions 66 and 66 (inward in the left and right direction), the through holes are formed when the housing 16 is manufactured by molding. The housing 16 can be formed as a single-piece product. Further, by forming the through holes 70 and 70 at positions that overlap with the locking holes 62 and 62 in the axial direction, for example, the locking holes 62 and 62 of the locking projections 36 and 36 through the through holes 70 and 70. It is also possible to visually recognize the locked state from the outside.

  Furthermore, in the present embodiment, the engagement mechanism for positioning the hollow needle 12 at the use position protruding from the housing 16 includes the locking protrusions 36 and 36 and the positioning holes 54 and 54. The locking protrusions 36 and 36 can be used not only to prevent the hollow needle 12 and the needle hub 14 from moving toward the proximal end but also to hold the hollow needle 12 and the needle hub 14 at the use position. Thus, the structure can be simplified. In particular, since the hollow needle 12 and the coil spring 84 that urges the needle hub 14 toward the proximal end side of the housing 16 are provided between the needle hub 14 and the housing 16, the pressing protrusions 58, 58 are left and right. The hollow needle 12 can be accommodated in the housing 16 with one touch by pushing inward in the direction to release the engagement between the locking projections 36 and 36 and the positioning holes 54 and 54.

  Next, FIGS. 7 to 9 show a needle assembly 90 as a second embodiment of the present invention. In this embodiment, the shape of the housing 92 is different from that of the first embodiment, while the shapes other than the housing 92 are the same as those of the first embodiment. In the present embodiment, members and parts that are substantially the same as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted. .

  That is, in the housing 92 of this embodiment, a pair of locking holes 96 and 96 are formed through the peripheral wall portion 94 on both sides in the left-right direction at the base end portion of the peripheral wall portion 94. These locking holes 96, 96 have a substantially rectangular shape when viewed from the front, and from the inner peripheral edge on the distal end side of the locking holes 96, 96, 98 is formed. That is, the base end side of these flexible wall portions 98 and 98 is the locking holes 96 and 96 that substantially penetrate the peripheral wall portion 94. The flexible wall portions 98 and 98 are not connected to the peripheral wall portion 94 on the three sides, and are bent and deformed in the left-right direction starting from the protruding base end (the inner peripheral edge portion on the distal end side of the locking holes 96 and 96). In this embodiment, elastic deformation is possible. In particular, in the present embodiment, the inner surface 100 of the peripheral wall portion 94 has a substantially constant shape in the axial direction, while the flexible wall portions 98 and 98 are thinner from the outside than the other portions of the peripheral wall portion 94. Thus, elastic deformation in the left-right direction is possible. In this embodiment as well, the housing 92 is an integrally molded product made of hard synthetic resin.

  By adopting the housing 92 as described above, the engagement between the locking projections 36 and 36 and the positioning holes 54 and 54 is released, and the hollow needle 12 and the needle hub 14 are moved to the proximal end side with respect to the housing 92. When the locking projections 36 and 36 are in sliding contact with the inner surface 100 of the housing 92 and reach the flexible wall portions 98 and 98, the locking projections 36 and 36 are elastically outward in the left-right direction. The flexible wall portions 98, 98 are pressed outwardly in the left-right direction by the locking projections 36, 36 according to a proper restoring force. Thereby, the flexible wall portions 98, 98 are deformed outward in the left-right direction, and the inner surface 102, 102 of the flexible wall portions 98, 98 among the inner surface 100 of the peripheral wall portion 94 has an inner diameter dimension in the left-right direction. Increased. That is, when the flexible wall portions 98 and 98 are deformed outward in the left-right direction, the inner surfaces 102 and 102 of these flexible wall portions 98 and 98 are moved in the left-right direction from the inner surface on the base end side of the locking holes 96 and 96. A large-diameter surface having a large inner diameter is formed.

  Then, the flexible wall portions 98, 98 are deformed outward in the left-right direction, so that the locking projections 36, 36 have a lateral width dimension based on the locking holes 96, 96 according to an elastic restoring action. It is made larger than the inner surface on the end side. In such a state, when further displaced to the base end side, as shown in FIGS. 10 to 12, the locking projections 36 and 36 enter the locking holes 96 and 96, and the locking projections 36 and 36. And the inclined surfaces 64 and 64 that are the inner surfaces of the locking holes 96 and 96 on the base end side abut against each other, so that the movement of the hollow needle 12 and the needle hub 14 toward the base end side with respect to the housing 92 can be prevented. That is, when the hollow needle 12 and the needle hub 14 move to the proximal end side with respect to the housing 92, the locking protrusions 36 and 36 are inserted into the locking holes 96 and 96, and the inner surfaces of the flexible wall portions 98 and 98 ( In the present embodiment, the inner surface (expanded surface) 102, 102 constitutes a guide surface.

  In the present embodiment, since the flexible wall portions 98 and 98 have elasticity, it is possible after passing through the inner surfaces (expanded surface, guide surface) 102 and 102 of the locking projections 36 and 36. The flexible wall portions 98 and 98 are restored and deformed to the initial shape, and the projecting tip surfaces (axial base end surfaces) of the flexible wall portions 98 and 98 restored to the initial positions and the locking projections 36 and 36 Are in contact with each other in the axial direction, so that the hollow needle 12 and the needle hub 14 are prevented from moving toward the distal end side with respect to the housing 92. Thereby, the re-projection of the hollow needle 12 from the housing 92 is prevented, and the hollow needle 12 is stably accommodated and protected in the housing 92.

  Also in the needle assembly 90 of the present embodiment configured as described above, the same effect as that of the needle assembly 10 of the first embodiment can be exhibited.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the specific descriptions in the embodiments, and various changes, modifications, improvements, and the like based on the knowledge of those skilled in the art. It is feasible in the form which added.

  For example, in the first embodiment, the guide surface is configured by the inclined surfaces 68 and 68 that gradually incline toward the outer peripheral side toward the base end side, but gradually spreads outward toward the base end side. It may be like this.

  Furthermore, in the first embodiment, inclined wall portions 66, 66 are provided between the flexible pieces 56, 56 and the locking holes 62, 62 in the housing 16, and the inner surfaces (inclined surfaces 68, 68), and in the second embodiment, flexible wall portions 98, 98 are provided at the base end portion of the housing 92, and the inner surfaces 102, 102 constitute the guide surface. However, the present invention is not limited to such a mode, and for example, a guide surface may be provided in substantially the entire length on the tip side of the locking hole. In other words, on the inner surface on the distal end side of the locking hole in the housing, a guide surface located on the outer peripheral side of the inner surface on the proximal end side with respect to the locking hole may be provided at least on the opening edge of the locking hole.

  Also in the first embodiment, as in the second embodiment, the locking protrusion is brought into contact with the inner peripheral side to bend and deform (elastically deform) toward the outer peripheral side. Also good.

  Furthermore, in the above-described embodiment, the engaging projections 36, 36 are engaged with the positioning holes 54, 54, whereby the engaging mechanism that holds the hollow needle 12 and the needle hub 14 in the use position is configured. However, the present invention is not limited to this mode. For example, an engaging mechanism may be provided separately without using the locking protrusion.

  Furthermore, in the second embodiment, the housing 92 is an integrally molded product and is made thinner than the other portions of the peripheral wall portion 94, so that the flexible wall portions 98 and 98 are configured. For example, the flexible wall portion may be formed as a separate body made of a material that is easily deformed, and then fixed to the housing. In such a case, the thickness dimension of the flexible wall portion may be equal to that of the peripheral wall portion.

  In the second embodiment, the flexible wall portions 98 and 98 can be elastically deformed. However, the flexible wall portions 98 and 98 are not limited to such an embodiment. After passing the surface, the flexible wall portion does not have to be restored to the initial position. In such a case, by separately adopting a mechanism for preventing the hollow needle and the needle hub from moving toward the distal end side like the engaging claws 52, 52 of the first embodiment, the hollow needle housing can be removed. Re-protruding can be prevented. However, in the first embodiment, the proximal ends of the inclined wall portions 66 and 66 and the locking projections 36 and 36 contact each other in the axial direction, so that the hollow needle 12 and the needle hub 14 are moved toward the distal end side with respect to the housing 16. The engagement claws 52, 52, etc. may not be provided when the movement is prevented.

  Furthermore, in the said embodiment, although the locking holes 62 and 62 (96, 96) were formed penetrating the surrounding wall part 38 (94), you may be made into the shape of the bottomed hole opened to an inner surface. .

  Furthermore, in the above-described embodiment, the elastic protrusions 34, 34, the locking protrusions 36, 36, the positioning holes 54, 54, the locking holes 62, 62 (96, 96), the pressing protrusions 58, 58, the guide surface ( A pair of inclined surfaces 68, 68, inner surfaces 102, 102) and the like are provided.

  Moreover, in the said embodiment, although the wing-like part 72 was attached to the housing 16 (92), in this invention, a wing-like part is not essential.

  Further, in the above-described embodiment, the housings 16 and 92 are integrally molded products made of a hard synthetic resin. However, for example, an inclined wall portion or a flexible wall portion that constitutes the guide surface is formed separately, and the peripheral wall portion is The fixing may be performed later, or the distal end side and the proximal end side may be formed separately from the locking hole, and the subsequent fixing may be performed.

  In the above-described embodiment, the housings 16 and 92 have a horizontally long substantially oval cylindrical shape, but may have a horizontally long substantially rectangular cylinder shape, for example. In such a case, the term “inner diameter” or “diameter” described in the second, third, and fifth aspects means that the left and right inner surfaces of the housing and the center of the rectangular cylinder that is the cross section of the housing Considered a directional distance. However, the housing is not limited to a horizontally long shape, and may be a cylindrical shape or a cylindrical shape having a square cross section.

10, 90: Needle assembly, 12: Hollow needle, 14: Needle hub, 16, 92: Housing, 34: Elastic protrusion, 36: Locking protrusion, 38, 94: Peripheral wall, 44, 100: Inner surface, 56: flexible piece, 58: pressing projection, 60: outer opening, 62, 96: locking hole, 68: inclined surface (guide surface), 70: through hole, 84: coil spring (biasing means), 98 : Flexible wall part, 102: Inner surface (expanded surface, guide surface)

Claims (9)

An engagement mechanism in which a needle hub of a hollow needle is inserted in a cylindrical housing so as to be movable in an axial direction, and the needle hub is positioned at a use position where the hollow needle protrudes from the housing; And an urging means for urging the hollow needle in the retracting direction with respect to the housing, and a needle assembly in which the hollow needle is retracted into the housing when the engagement mechanism is released. In
A locking hole is provided on the inner surface of the housing, and a locking protrusion is provided that elastically protrudes from the needle hub toward the inner surface of the housing. The locking protrusion is locked in the locking hole at the retracted position to prevent re-projection of the hollow needle from the housing, and
As the hollow needle is pulled into the housing, the inner surface on the axially forward side of the locking hole of the housing where the locking projection slides toward the locking hole is at least the locking hole. The opening edge portion is a guide surface that is positioned on the outer peripheral side of the axially rearward inner surface of the locking hole in the housing and guides the locking projection into the locking hole. Needle assembly.   In the housing, an inner surface that is located on the axially front side of the locking hole and in which the locking projection is slidably contacted has a larger inner diameter than an inner surface on the axially rear side of the locking hole. The needle assembly according to claim 1, wherein the guide surface is configured as a surface.   In the housing, the guide surface, which is positioned axially forward of the locking hole and slidably contacts the locking projection, has an inner diameter gradually toward the axially rear side where the locking hole is positioned. The needle assembly according to claim 2, wherein the needle assembly has a large inclined surface.   The through-hole which penetrates toward the width direction of the said guide surface which becomes substantially right-angled with respect to the drawing-in direction of the said hollow needle in the surrounding wall part of the said housing is extended and provided on this guide surface. A needle assembly according to claim 1.   In the housing, the guide surface that is positioned axially forward of the locking hole and is in sliding contact with the locking projection is configured by a deformable flexible wall, The locking projection that slides and moves toward the locking hole is pressed against the flexible wall so that the flexible wall is an enlarged-diameter surface that deforms outward. The needle assembly according to any one of 1 to 4.   The needle assembly according to claim 5, wherein the flexible wall portion is configured by thinning a peripheral wall portion of the housing at a portion constituting the guide surface.   7. The housing according to claim 1, wherein a portion located on the front side in the axial direction from the locking hole and a portion located on the rear side in the axial direction are formed as a single part. The needle assembly according to Item.   In the needle hub, a pair of elastic protrusions that are inclined in the axial direction and extend outward are provided, and the locking protrusions are provided at the tip portions of the elastic protrusions, A positioning hole is provided in the peripheral wall portion of the housing at a position farther toward the distal end side in the axial direction than the locking hole, and the hollow needle is attached to the hollow needle by the engaging action of the locking projection with respect to the positioning hole. The needle assembly according to any one of claims 1 to 7, wherein the engagement mechanism is configured to be held in the use position protruding from the housing. While the positioning hole penetrates the peripheral wall portion of the housing, a flexible piece provided with a pressing projection facing the outer opening of the positioning hole is provided in the housing,
By engaging the locking protrusion provided on the needle hub and engaged with the positioning hole with the pressing protrusion from the outer peripheral side of the housing, the engagement of the locking protrusion with the positioning hole is released. 9. A needle assembly according to claim 8, adapted for use.

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