Medical needle with protector

A medical needle with a protector (1) includes: a hub (3) that supports a needle tube (2); a protector (4) capable of storing the needle tube (2); a first lock unit (42a, 42b, 73) that locks the hub (3) to the protector (4) capable of unlocking; and a second lock unit (43, 44, 74, 75) that locks the hub (3) to the protector (4) incapable of unlocking. The hub front end has a pair of first protrusion portions (74) in the vertical direction and a pair of second protrusion portions (75) in the horizontal direction. The protector rear end has a pair of protrusion pieces (43) in the horizontal direction and a pair of side wall portions (44) in the vertical direction. The space between the side wall portions (44) is the width of the protrusion portions (74 and 75) or larger and the height of the same or smaller.

TECHNICAL FIELD

The present invention relates to a medical needle with a protector.

BACKGROUND ART

There has been conventionally known a medical needle with a protector that has a hub with a front end supporting the rear end of a needle tube and a rear end connected to a flexible tube and a cylindrical protector capable of storing the hub (for example, refer to Patent Literature 1).

In the medical needle with a protector, it is desired that, after insertion into a blood vessel or the like, the needle tube does not come off, and after use, the needle tube housed in a needle protector does not protrude again to avoid erroneous puncture. Thus, the medical needle with a protector includes: a first lock unit that locks the hub to the protector in a manner capable of unlocking with the needle tube protruded from the protector; and a second lock unit that locks the hub to the protector in a manner incapable of unlocking with the needle tube stored in the protector.

According to the medical needle with a protector, when the needle tube is protruded from the protector and is inserted into a blood vessel or the like, the hub is locked in the protector by the first lock unit to prevent the needle tube from coming off the blood vessel. After use, the hub is unlocked from the first lock unit so that the needle tube can be stored in the protector.

Further, according to the medical needle with a protector, when the needle tube is stored in the protector, the hub is locked to the protector by the second lock unit and thus will not protrude again, thereby capable of preventing erroneous puncture.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In the foregoing conventional medical needle with a protector, each of the hub and the protector are made of a synthetic resin and formed by injection molding. However, when an attempt is made to assemble the separately molded hub and protector together, there is a problem the first lock unit or the second lock unit may interfere, and cannot assemble.

To solve the foregoing problem, for example, it is considered that either one of the hub and the protector may be molded in advance and is placed in advance in a molding die at the injection molding of the other for insert molding so that the product with the hub and the protector assembled together can be obtained.

However, the insert molding requires a molding die of an intricate structure which would cause the inconvenience of performing complicated operations.

To eliminate such inconvenience, an object of the present invention is to provide a medical needle with a protector that allows the separately molded hub and protector to be easily assembled together.

Solution to Problem

To attain the object, a medical needle with a protector of the present invention includes: a hub at a front end supporting a rear end of a needle tube; a cylindrical protector that is capable of storing the needle tube by sliding the hub; a first lock unit that locks the hub to the protector in a manner capable of unlocking with the needle tube protruded from the protector; and a second lock unit that locks the hub to the protector in a manner incapable of unlocking with the needle tube stored in the protector. A front end of the hub includes: a pair of first protrusion portions that is provided on a first axial line orthogonal to an axial line of the hub and is individually protruded in a direction away from an outer peripheral surface of the hub; and a pair of second protrusion portions that is orthogonal to the axial line of the hub at a first predetermined space from the first protrusion portions to the rear end side, is provided on a second axial line crossing the first axial line at a predetermined angle as seen from the axial line of the hub. A rear end of the protector has: a pair of protrusion pieces that is provided on a third axial line orthogonal to an axial line of the protector, extends individually from an inner peripheral surface of the protector toward the axial line of the protector while inclining toward the rear end side, and is elastically deformable in a direction away from the axial line of the protector; and a pair of side wall portions that is provided on the inner peripheral surface of the protector with a second predetermined space equal to or smaller than the first predetermined space from the protrusion pieces of the protector to the front end side and is opposed to each other on a fourth axial line crossing the third axial line at the predetermined angle as seen from the axial line of the protector. The second lock unit is configured such that, when the needle tube is stored in the protector, front end sides of the side wall portions of the protector are locked to the first protrusion portions of the hub and rear end sides of the protrusion pieces of the protector are locked to the second protrusion portions. A space between the pair of side wall portions is set to be equal to or larger than a maximum width of the both protrusion portions in the direction orthogonal to the first axial line as seen from the axial line of the hub and smaller than a distance from one protrusion end to the other protrusion end of each of the protrusion portions.

The medical needle with the protector of the present invention includes the hub and the cylindrical protector into which the hub is to be assembled. The hub has the front end supporting the rear end of the needle tube, and the protector stores the needle tube.

When the medical needle with a protector of the present invention is inserted into a blood vessel or the like with the needle tube protruded from the protector, the hub is locked in the protector by the first lock unit to prevent the needle tube from coming off the blood vessel or the like.

In the medical needle with the protector of the present invention, after removal from the blood vessel or the like, the hub is released from the state of being locked in the protector by the first lock unit and the hub is moved backward to draw the needle tube into the protector.

Then, when the first protrusion portions and the second protrusion portions of the hub are moved backward to the rear end side of the protector, since the protrusion pieces at the rear end side of the protector extend from the inner peripheral surface of the protector to the rear end side toward the axial line of the protector, the first protrusion portions and the second protrusion portions are deformed in the direction away from the axial line of the protector by the rear end sides of the second protrusion portions. When the hub is further relatively moved backward, the protrusion pieces go beyond the second protrusion portions and return to the original state due to their elasticity. Accordingly, the protrusion pieces are locked from the rear end side by the second protrusion portions.

At this time, the first predetermined space between the first protrusion portions and the second protrusion portions of the hub is equal to or larger than the second predetermined space between the protrusion pieces and the side wall portions of the protector, and thus the first protrusion portions of the hub lock the side wall portions of the protector.

As a result, the first protrusion portions and the second protrusion portions of the hub constituting the second lock unit sandwich the side wall portions and the protrusion pieces of the protector. Accordingly, the hub is locked in the protector in a manner incapable of unlocking and cannot be moved forward or backward. Therefore, the needle tube will not be protruded again from the protector, which makes it possible to prevent wrong insertion.

To assemble the hub into the protector, the front end side of the hub is inserted into the rear end side of the protector. At this time, when an attempt is made to insert the front end side of the hub into the rear end side in the posture in which the hub is stored in the protector, the space between the side wall portions is set to be smaller than the distance from the one protrusion end to the other protrusion end of each of the first protrusion portions, and thus the first protrusion portions hit against the side wall portions to inhibit the insertion.

However, the space between the side wall portions is equal to or larger than the maximum width of the first protrusion portions in the direction orthogonal to the first axial line as seen from the axial line of the hub. Accordingly, rotating the protector and the hub relatively around their central axes makes it possible to insert the hub from the side wall portions to the front end side while avoiding a collision with the side wall portions.

The second protrusion portions can be moved forward by the rotation while avoiding a collision with the protrusion pieces, but the space between the side wall portions is set to be smaller than the distance from the one protrusion end to the other protrusion end of each of the second protrusion portions, and thus the hub hits against the side wall portions and cannot be inserted any longer.

However, the space between the side wall portions is equal to or larger than the maximum width of the second protrusion portions in the direction orthogonal to the first axial line as seen from the axial line of the hub. Accordingly, rotating the protector and the hub in the direction opposite to the previous direction makes it possible to insert the second protrusion portions from the side wall portions to the front end side while avoiding a collision with the side wall portions, whereby the hub is completely assembled into the protector.

Therefore, according to the medical needle with a protector of the present invention, the separately molded hub and protector can be easily assembled together without performing insert molding or the like.

In the medical needle with the protector of the present invention, it is preferred that the outer peripheral surface of the hub has a streak along the axial line of the hub and the side wall portions have a slit through which the streak passes.

According to this, when the hub is relatively moved backward from the protector, the streak in the hub is guided by the slit in the side wall portions along the axial line of the hub. Accordingly, the hub can be smoothly moved backward.

In the medical needle with the protector of the present invention, it is preferred that the side wall portions are formed from a pair of plate spring members elastically deformable in a direction in which the side wall portions of the protector are separated from the axial line of the protector, and the slit is formed by separating the opposing protrusion ends of the plate spring members from each other at a predetermined distance.

According to this, when the protector and the hub are gradually rotated in the direction opposite to the previous direction in a relative manner around their central axes, the streak deforms the plate spring members outward. Then, when the protector and the hub further rotate, the plate spring members go over the streak and return to the original state due to their elasticity. Accordingly, the streak is fitted into the slit formed by the gap between the pair of plate spring members. Therefore, according to the thus configured medical needle with a protector, the hub with the streak can be easily assembled with the protector,

The protector preferably includes a pair of wing-like members. In the medical needle with a protector of the present invention, the needle tube can be inserted into a blood vessel or the like by overlapping and picking up the pair of wing-like members. In the medical needle with a protector of the present invention, after the insertion of the needle tube into the blood vessel or the like, the pair of wing-like members can be opened and fixed to the skin by an adhesive tape or the like.

DESCRIPTION OF EMBODIMENT

As illustrated inFIG. 1, a medical needle with a protector1of the present embodiment includes a hub3that supports a needle tube2with a sharpened front end, a cylindrical protector4into which the hub3is assembled, and a pair of wing-like members5externally fitted to the protector4.

The protector4is formed by injection molding of a polypropylene resin or the like and is capable of storing the needle tube2. The wing-like members5are formed by injection molding of a soft resin such as a vinyl chloride resin.

As illustrated inFIG. 2A, the hub3is formed from a hub base portion7with the rear end connected to a flexible tube6and a small cylindrical portion71extending from the front end of the hub base portion7in the front-end direction. The rear end of the needle tube2is supported by the front end of the small cylindrical portion71.

The hub3is formed by injection molding of a synthetic resin such as acrylonitrile-butadiene-styrene copolymer resin (ABS resin), for example.

As illustrated inFIGS. 2B and 2C, the small cylindrical portion71includes a needle tube support portion72ain which the needle tube2is inserted and supported at the front end side. The hub base portion7includes a connection tube portion72bconnected to the flexible tube6at the rear end side. The needle tube support portion72aand the connection tube portion72bcommunicate with each other via a hollow portion72cin the middle thereof.

The rear end of the hub base portion7has a pair of arms73and73in symmetry with respect to the central axis of the small cylindrical portion71as illustrated inFIGS. 2A and 2C. The arms73and73are provided along the length of the small cylindrical portion71with a space from the hub base portion7. Each of the arms73has a hook73bvia a neck portion73a. The front end of the hook73bhas an inclination surface73cfrom the front end side to the rear end side such that the side of the surface in proximity to the small cylindrical portion71is sharpened.

The hub base portion7is formed form an ABS resin as described above, and thus the arms73and73are pressurized in an arrow direction and are elastically deformable in the direction of the small cylindrical portion71. When being depressurized, the arms73and73can return to the original state due to their elasticity.

As illustrated inFIGS. 2A to 2C, a first protrusion portion74and a second protrusion portion75are provided on the outer peripheral surface of the front end of the small cylindrical portion71. The first protrusion portion74is provided on the front end of the small cylindrical portion71, and the second protrusion portion75is provided closer to the rear end side than the first protrusion portion74with a first predetermined space from the first protrusion portion74.

The first protrusion portions74protrude along a line orthogonal to a line connecting the arms73and73(corresponding to a first axial line of the present invention) as seen from the front end side. The second protrusion portions75protrude along the line connecting the arms73and73(corresponding to a second axial line of the present invention) as seen from the front end side.

A pair of first protrusion portions74is provided with a slope74aat the front end in a vertically symmetrical manner (seeFIG. 2A). The slopes74aare formed to be gradually higher from the front end to the rear end. A pair of second protrusion portions75is provided with a slope75aat the rear end in a horizontally symmetrical manner (seeFIG. 2A). The slopes75aare formed to be gradually lower from the front end to the rear end.

Streaks76are provided entirely on the outer peripheral surface of the small cylindrical portion71along the axial line from the first protrusion portions74to the hub base portion7.

In the following description, the distance from the protrusion end of one first protrusion portion74to the protrusion end of the other first protrusion portion74will be called “height”, and the maximum width in a direction orthogonal to both the height direction of the first protrusion portions74and the axial line of the small cylindrical portion71. The foregoing definition also applies to the second protrusion portions75.

In the foregoing embodiment, one each pair of the protrusion portions74and75is provided on the outer peripheral surface of the front end of the small cylindrical portion71. Alternatively, one each of the protrusion portions74and75may be provided. In addition, the first protrusion portions74and the second protrusion portions75protrude with a phase shift of 90 degrees, but the present invention is not limited to this. The first protrusion portions74and the second protrusion portions75may have a phase shift of another degree as far as the first protrusion portions74and the second protrusion portions75do not protrude in parallel to each other (0 or 180 degrees).

As illustrated inFIGS. 3A to 3C, the protector4includes a width-increased portion42that gradually increases in width from the front end side to the rear end side in a planar view (seeFIG. 3B) at the rear end of a large cylindrical portion41. The internal space in the large cylindrical portion41is set such that the small cylindrical portion71(including the protrusion portions74and75) is slidable therein.

The rear end of the width-increased portion42includes insertion portions42aand42ainto which the arms73and73are inserted. Each of the insertion portions42aincludes a window42bon a lateral side such that the hook73bof the arm73inserted into the insertion portion42ais locked at the window42b. That is, the arms73and the hooks73bof the hub base portion7and the insertion portions42aand windows42bof the protector4constitute a first lock unit.

As illustrated inFIGS. 3A to 3C, the rear end of the protector4has protrusion pieces43and43and side wall portions44and44.

As illustrated inFIGS. 3A and 3B, the protrusion pieces43and43are plate-like members that extend to the rear end side while inclining toward the axial line of the protector4. A pair of protrusion pieces43and43is provided continuously from the rear end of the large cylindrical portion41in a horizontally symmetrical manner (seeFIG. 3A). The lateral direction corresponds to a third axial line orthogonal to the axial line of the protector4in the present invention.

The protrusion pieces43are curved in a convex form outward from the axial line of the protector4. The distance between the protrusion ends of the pair of protrusion pieces43and43is set to be equal to or longer than the height of the second protrusion portions75and75. In the present embodiment, the distance between the protrusion ends of the pair of protrusion pieces43and43is set to be substantially equal to the diameter of the small cylindrical portion71.

Since the protector4is formed from a polypropylene resin as described above, the protrusion pieces43are elastically deformable in the direction away from the axial line of the large cylindrical portion41(the horizontal direction illustrated inFIG. 3A).

The side wall portions44are provided with a second predetermined space from the front end side of the protrusion pieces43as illustrated inFIGS. 3A and 3B. The second predetermined space (the distance from the front ends of the side wall portions44to the rear ends of the protrusion pieces43) is substantially identical to the first predetermined space (the distance from the rear ends of the first protrusion portions to the front ends of the second protrusion portions) in the present embodiment. However, the present invention is not limited to this but the second predetermined space may be equal to or smaller than the first predetermined space.

The side wall portions44are flat plate-like members that extend horizontally closer to the inner side than the inner peripheral surface of the large cylindrical portion41as illustrated inFIG. 3C. A pair of side wall portions44is provided in the vertical direction of the protrusion pieces43. The vertical direction corresponds to a fourth axial line that crosses the third axial line at a predetermined angle as seen from the axial line of the protector in the present invention.

The distance between the pair of side wall portions44and44is equal to or longer than the width of the protrusion portions74and75, and is equal to or shorter than the height of the protrusion portions74and75. In the present embodiment, the distance between the pair of side wall portions44and44is set to be substantially equal to the diameter of the small cylindrical portion71.

Each of the side wall portions44is formed from a pair of plate spring members44aand44a. The plate spring members44aextend from the inner peripheral surface of the large cylindrical portion41toward the center along the horizontal direction. In addition, there is a space provided between the plate spring members44aand the inner peripheral surface of the large cylindrical portion41(the width-increased portion42). The protector4is formed from a polypropylene resin as described above and thus the plate spring members44aare elastically deformable outward of the large cylindrical portion41(the vertical direction illustrated inFIG. 3A). The protrusion ends of the pair of plate spring members44aand44aconstituting each of the side wall portions44have a slit44bformed by a predetermined space therebetween.

In the present embodiment, the slits44bare formed by the pairs of plate spring members44a, but the present invention is not limited to this. The slits44bmay be formed by making grooves in the side wall portions44.

Next, an operation of storing the needle tube2into the protector4in the medical needle with a protector1after removal from a blood vessel or the like will be described with reference toFIGS. 4A.4B and5.

When the needle tube2is inserted into a blood vessel or the like, as illustrated inFIG. 4A, the hooks73bat the front ends of the arms73in the hub base portion7are locked in the windows42bof the protector4so that the needle tube2is protruded from the protector4.

Accordingly, after the removal of the needle tube2from the blood vessel or the like, the arms73are pressurized in the direction of arrow and are elastically deformed in the direction of the small cylindrical portion71to unlock the hooks73bfrom the windows42b.

Then, as illustrated inFIG. 4B, the hub3is moved backward while the arms73remain deformed in the direction of the small cylindrical portion71. Accordingly, the needle tube2is drawn into the large cylindrical portion41. At this time, as illustrated inFIG. 7C, the streaks76of the small cylindrical portion71are guided by the slits44band thus the hub3can be smoothly moved backward.

Then, when the hub3is moved backward, the second protrusion portions75and75abut with the protrusion pieces43and43as illustrated inFIG. 5A. The protrusion pieces43are elastically deformable as described above, and thus are guided by the slopes75aof the second protrusion portions75in the direction away from the axial line of the large cylindrical portion41(the vertical direction illustrated inFIG. 5A).

After that, as illustrated inFIG. 5B, when the hub3is further moved backward and the needle tube2not illustrated in the drawing is stored in the large cylindrical portion41, the protrusion pieces43and43go over the second protrusion portions75and75and return to the original state by their elasticity. Then, the protrusion pieces43and43are fitted into clearances between the first protrusion portions74and the second protrusion portions75. Accordingly, in a planar view (seeFIG. 5B), the rear ends of the protrusion pieces43and43are locked by the front ends of the second protrusion portions75and75.

At this time, the distance from the front ends of the side wall portions44to the rear ends of the protrusion pieces43(second predetermined distance) is substantially identical to the distance from the rear ends of the first protrusion portions to the front ends of the second protrusion portions (first predetermined space) as described above, the front ends of the side wall portions44are also locked by the rear ends of the first protrusion portions74and74in a side view (seeFIG. 5C).

That is, the protrusion pieces43and the side wall portions44of the protector4are sandwiched between the protrusion portions74and75of the hub3. In the present embodiment, the protrusion portions74and75of the hub3and the protrusion pieces43and the side wall portions44of the protector4constitute a second lock unit of the present invention.

As a result, the protrusion pieces43, the side wall portions44, and the protrusion portions74and75cannot be unlocked unless the protrusion pieces43are deformed outward, and thus the needle tube2will not be protruded again from the large cylindrical portion41. This makes it possible to prevent wrong insertion.

Next, the operation of assembling together the separately d hub3and protector4will be described with reference toFIGS. 6A to 6D.

To assemble the hub3into the protector4, the front end side of the hub3is inserted into the rear end side of the protector4. At this time, if an attempt is made to insert the front end side of the hub base portion7into the rear end side of the protector4in such a manner as to insert the pair of arms73and73of the hub base portion7into the insertion portion42aof the large cylindrical portion41, the space between the protrusion ends of the pair of protrusion pieces43and43is equal to or shorter than the height of the second protrusion portions75and75and thus the front ends of the second protrusion portions75and75hit against the protrusion ends (rear ends) of the protrusion pieces43and43.

Accordingly, as illustrated inFIG. 6A, the protector4and the hub3are relatively rotated 90° around their central axes. Then, when an attempt is made to insert the front end side of the hub3into the rear end side of the protector4, the protrusion pieces43are elastically deformable as described above, and thus the protrusion pieces43are guided along the slopes74aof the first protrusion portions74and deformed in the direction away from the axial line of the large cylindrical portion41, and then the first protrusion portions74and74pass through the protrusion pieces43and43and move toward the front end side.

Further, as illustrated inFIG. 6A, when the pair of side wall portions44and44is oriented in the vertical direction, the width direction of the first protrusion portions74is aligned with the vertical direction. The distance between the pair of side wall portions44and44is set to be equal to or longer than the width of the first protrusion portions74, and thus the first protrusion portions74pass through the side wall portions44and44.

In addition, the second protrusion portions75and75are relatively rotated 90° around the central axes, which makes it possible to prevent a collision with the protrusion pieces43.

Then, when the hub3is moved forward, the second protrusion portions75and75hit against the side wall portions44and44as illustrated inFIG. 6B.

Next, as indicated with an arrow inFIG. 613, the protector4and the hub3are relatively rotated 90° in the direction opposite to the former direction around their central axes. Accordingly, the hub3returns into the position where the arms73and73can be inserted into the insertion portions42aand42aof the protector4.

The state of deformation of the side wall portions44by the streaks76at this time will be described with reference toFIGS. 7A to 7C.

First,FIG. 7Ais a cross-sectional view ofFIG. 6Btaken along line VII-VII. When the plate spring members44aand44ain this state are rotated in the direction of arrow, the plate spring members44aand44aare elastically deformable with respective vertical spaces and thus are pushed into the streaks76and76and deformed in the direction away from the axial line of the large cylindrical portion41as illustrated inFIG. 7B.

When the plate spring members44aand44aare rotated in the direction of arrow, the plate spring members44aand44ago over the streaks76and76and return to the original state due to their elasticity as illustrated inFIG. 7C. Accordingly, the streaks76and76are fitted into the slits44bbetween the pairs of opposed plate swing members44aand44a.

Returning toFIGS. 6A to 6D, the operation after the completion of the rotation will be described. At this time, the first protrusion portions74and74have already passed through the side wall portions44and44and thus the first protrusion portions74and74are arranged closer to the front end side than the side wall portions44as illustrated inFIG. 6C.

In addition, the second protrusion portions75and75are rotated in the state of having moved forward closer to the front end side than the protrusion ends of the protrusion pieces43and43. Accordingly, as illustrated inFIG. 6D, the second protrusion portions75and75are arranged closer to the front end side than the protrusion ends (rear ends) of the protrusion pieces43and43while forcedly opening the protrusion pieces43and43.

Accordingly, while the hub3is moved forward, when the pair of side wall portions44and44is oriented in the vertical direction, the width direction of the second protrusion portions75is aligned with the vertical direction as illustrated inFIG. 6C. The distance between the pair of side wall portions44and44is set to be equal to or longer than the width of the second protrusion portions75, and thus the second protrusion portions75also pass through the side wall portions44and44.

When the hub3is further moved forward and the arms73collide with the insertion portions42a, the arms73have inclined surfaces73cat front ends and thus are gradually pressurized and deformed toward the small cylindrical portion71and inserted into the insertion portions42a. When the hub3is further moved forward in that state, the hooks73bat the front ends of the arms73reach the windows42band the arms73are released from the pressure. Accordingly, the arms73return to the original state due to their elasticity and the hooks73bare locked in the windows42b.

As a result, as illustrated inFIG. 4A, the hub3can be assembled into the protector4.

Next, a medical needle with a protector according to a modification example of the present embodiment will be described with reference toFIGS. 8A to 8C.

A hub3according to the modification example further has a first flat surface74bon part of the outer peripheral surface of the first protrusion portion74in the vertical direction (seeFIG. 8A) as illustrated inFIG. 8A. The first flat surface74bconnects to other outer peripheral surfaces of the first protrusion portion74via step portions74c.

In addition, the inner peripheral surface of a protector4according to the modification example has a second flat portion45corresponding to the first flat portion74balong the axial line of the protector4from the front end to rear end as illustrated inFIG. 8B. The second flat portions45are vertically provided on the inner peripheral surface of the large cylindrical portion41and connect to other inner peripheral surfaces of the large cylindrical portion41via step portions45acorresponding to the step portions74c.

Accordingly, as illustrated inFIG. 8C, the flat surface74bof the hub3and the flat surface45of the protector4slide on each other with the step portions74cand74cof the hub base portion7sandwiched between the step portions45aand45aof the protector4. Therefore, according to the medical needle with a protector in the modification example, the hub3can be moved backward more smoothly.

REFERENCE SIGNS LIST