JP3531141B2 - Micro injector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microinjector used by being attached to a micromanipulator or the like.

[0002]

2. Description of the Related Art In the fields of basic medicine and biotechnology, cells are held for holding cells such as organs and tissues of living organisms, egg cells and single cells, and performing cell processing such as suction, injection and division. So-called micro-manipulation is performed. In this micromanipulation, a microinjector attached to a holder of a micromanipulator is used to hold cells and perform operations such as suction and injection.

A conventional microinjector for performing these operations is shown in FIG. 8, for example.

In this microinjector 50, a syringe 52, which is a glass syringe, is fixed to a base 51, and has a plunger 53 which is concentrically arranged and inserted into the syringe 52. Two O-rings 54, 54 are continuously attached to the tip of the plunger 53 in the longitudinal direction of the syringe 52. The interior of the syringe 52 is kept liquid-tight by the O-rings 54, 54, and the injection liquid I is filled therein.

A connecting portion 56 to which the feed screw 55 is connected is provided at the rear end of the plunger 53. The feed screw 55 is screwed into a female screw 57a that is threaded on a screw portion 57 formed at the rear end of the base 51.
An operation handle 58 is attached to the rear end of the feed screw 55 for the operator to pick and rotate.

Further, an injection liquid inlet / outlet port 52A is provided at the tip of the syringe 52. One end of the flexible hose H is connected to the injection liquid inlet / outlet port 52A, and the other end of the flexible hose H is connected to a suction / injection unit (not shown).

In such a conventional microinjector 50, when an operator picks up the operating handle 58 and rotates it clockwise, for example, the feed screw 55 rotates in the same direction as the operating handle 58. The feed screw 55 is a female screw 5 threaded on a screw portion 57 provided on the base 51.
It is screwed into 7a and moves forward relative to the base 51. When the feed screw 55 moves forward, the plunger 53 also moves forward and pushes out the injection liquid I in the syringe 52 from the injection liquid inlet / outlet port 52A. When the injection liquid I is pushed out from the injection liquid inlet / outlet port 52A, the injection liquid I is discharged from the tip of the micropipette in the suction / injection unit (not shown) via the flexible hose H. At this time, the tip of the micropipette is inserted, for example, into the injection liquid stored in a petri dish placed on a microscope (not shown), and the injection liquid is injected into the injection liquid stored in the petri dish. Done. Alternatively, an operation of inserting the tip of the micropipette into an egg not shown and injecting sperm not shown stored in the micropipette is performed. When the operation handle 58 is rotated counterclockwise, the injection liquid stored in a petri dish placed on a microscope (not shown) is sucked. Utilizing this property, an operation such as sucking the injection liquid or sperm swimming in the injection liquid, or holding an egg or the like in the injection liquid is performed.

[0008]

By the way, since the suction / injection work using the microinjector is performed on a minute substance such as sperm, it is required to move with high accuracy. In order to meet such a demand, the conventional microinjector 50 has a feed screw 55 and a screw portion 57.
The female screw 57a, which was threaded in the end, was finished as accurately as possible. However, even if the finishing is simply performed with high precision, the backlash between the feed screw 55 and the female screw 57a cannot be completely removed, and there is a problem that it is difficult to operate with high precision.

Further, since the syringe 52 has a very small diameter, unless the axial center of the syringe 52 and the axial center of the plunger 53 are aligned with high accuracy, the plunger 53 does not move smoothly, especially when the plunger 53 retreats greatly. There were times when things didn't work. Therefore, in order to move the plunger 53 smoothly, it is necessary to dispose the plunger 53 concentrically with respect to the syringe 52 with high accuracy, and the work is troublesome. Further, the connecting portion 56 between the plunger 53 and the feed screw 55 is connected to the feed screw 5.
Since it is provided at the tip of No. 5, when the axial center of the plunger 53 is tilted with respect to the axial center of the syringe 52, the tilt has a large influence, and the plunger 53 is moved only by slightly tilting the axial center. There was a problem that it became difficult.

Therefore, an object of the present invention is to provide a microinjector that can move with high accuracy. Also, even when the plunger is not completely concentric with the syringe, it allows the plunger to move smoothly, and when setting the plunger in the syringe, the plunger is placed with high accuracy and concentricity with the syringe. There is no need to place it in.

[0011]

[0012]

[0013]

[0014]

[0015]

[Means for Solving the Problems]
According to a first aspect of the present invention , in a microinjector including an operating portion and a suction / injecting portion, the operating portion has a plunger that is inserted into a syringe fixed to a base, and is provided along an inner surface of the syringe. A plunger head to which an O-ring that slides is attached is attached to the tip end portion of the plunger, and a feed screw is screwed into a base-side screw portion formed on the base, and the feed screw is
The plunger is connected to the rear part of the plunger and can be moved forward and backward relative to the base by rotating, and the connecting part between the feed screw and the plunger is located behind the feed screw. It is a microinjector characterized by being provided.

In the invention according to claim 1 , since the connecting portion between the feed screw and the plunger is provided at the rear of the feed screw and the distance between the fulcrums of the plunger becomes long, the parallel stability of the plunger becomes high. Therefore, even if the axis of the plunger is tilted with respect to the axis of the syringe, the effect of the tilt on the angular deviation between the axis of the syringe and the axis of the plunger becomes small, and the plunger moves smoothly. be able to. Further, the plunger can be made to move smoothly without arranging the plunger concentrically with the syringe with high accuracy.

According to a second aspect of the present invention, the connecting portion includes:
請 characterized in that the second bearing pivotally supporting the first bearing and the side surface of said plunger for pivoting the rear end of the plunger pivotally rotatably is provided
The microinjector according to claim 1 .

According to the second aspect of the invention, the rear end of the plunger is pivotally supported by the first bearing. For this reason, it is possible to eliminate the play that separates the bearing and the plunger in the longitudinal direction of the plunger, so that the responsiveness of the plunger to the movement of the feed screw can be made very good. Moreover, since the second bearing pivotally supports the vicinity of the rear end portion of the plunger, the axial center of the plunger is prevented from shifting.

In the invention according to claim 3 , the O-ring is
The microinjector according to claim 1 or 2 , wherein only one is attached to the plunger head.

In the conventional microinjector, two O-rings are used so that the plunger can move along the axis of the syringe. However, since there are two O-rings, the axis of the syringe and the axis of the plunger are If the mind is placed off-center, smooth movement of the plunger may be hindered. In this respect, in the invention according to claim 3 , since only one O-ring is attached, even if the axis of the syringe is slightly deviated from the axis of the plunger, the plunger can be moved smoothly with respect to the syringe. You can

The invention according to claim 4 is the microinjector according to claim 3 , characterized in that a guide member for adjusting the plunger concentrically with respect to the syringe is provided.

[0022] When the O-ring and only one, O-ring would plunger is swung around the, hardly suit the axis of the axial center and the plunger of the syringe but, claim 4
In the invention according to (1), the guide member for adjusting the plunger concentrically with respect to the syringe is provided. Therefore, the axis of the syringe and the axis of the plunger can be easily aligned.

According to a fifth aspect of the present invention, at least a portion of the outer surface of the syringe that comes into contact with the base is polished, and any one of the first to fourth aspects is characterized. The microinjector described in 1.

In the conventional microinjector, normally, in order to move the plunger smoothly with respect to the syringe,
The inner surface of the syringe was polished, but the outer surface of the syringe was not polished. On the other hand, in the invention according to claim 5 , at least a portion of the outer surface of the syringe that contacts the base is polished. Therefore, since the syringe can be attached to the base with high accuracy, it is easy to dispose the plunger concentrically with the syringe. In addition, the microinjector can be moved smoothly and highly accurately accordingly.

[0025] The invention according to claim 6, wherein claim 1, wherein the syringe is characterized in that it consists of a metal syringe
Item 5. The microinjector according to any one of items 5 .

In the sixth aspect , a metal syringe is used as the syringe. Conventionally, a glass syringe has been used as a syringe, but by using a metal syringe, it is hard to break and the plunger can be moved more smoothly.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a perspective view of a microinjector according to the present invention, FIG. 2 is an exploded perspective view of its operating portion, and FIG. 3 is a side sectional view of the operating portion.
As shown in FIG. 1, the microinjector 1 according to the present invention includes an operation unit 2 and a suction / injection unit 3.

The operating section 2 has a base 10 as shown in FIGS. Front part 10A of this base 10
A groove having a V-shaped cross section is formed in the rear portion, and the rear portion of the rear portion 10B of the base 10 is formed in a substantially cylindrical shape. A syringe 11 made of a metal syringe is attached to the front portion 10A of the base 10 by the fastening member 11A.
It is clamped to 0 and fixed. The outer surface of the syringe 11 is entirely polished, and the portion clamped by the clamping member 11A is also polished. For this reason,
The syringe 11 can be tightened so that the height position is accurate.

The operating section 2 has a plunger 12 to be inserted into the syringe 11, and a plunger head 13 is attached to the tip of the plunger 12 as shown in FIGS. 2 and 3. This plunger head 1
An O-ring 14 that slides along the inner surface of the syringe 11 is attached to the syringe 3.
By making contact with the inner surface of 1, the inner surface of the syringe 11 and the plunger head 13 are kept liquid-tight.

The plunger 12 has a front rod 12A and a rear rod 12B, and a disc-shaped front connecting portion 12C is provided at the rear end portion of the front rod, and the rear rod 12B.
A rear connecting portion 12D formed with a male screw is provided at the front end portion of the. Then, by inserting the male screw of the rear connecting portion 12D into the female screw member 12E across the front connecting portion 12C, the front rod 12A and the rear rod 12B are completely fixed in a state where the front rod 12A and the rear rod 12B are fixed.
Are connected in a straight line.

Further, the plunger 1 is provided at a position near the front connecting portion 12C of the front rod 12A of the plunger 12.
A guide member 15 that adjusts the position of the device 2 concentrically with respect to the syringe 11 is provided. The guide member 15 is
The syringe 11 has a cylindrical shape having an outer diameter substantially the same as the inner diameter of the syringe 11 and can be fitted into the syringe 11. When inserting the plunger 12 into the syringe 11 and fixing the syringe 11 to the base 10, as shown in FIG. 2, by inserting the guide member 15 into the syringe 11, the axis of the syringe 11 and the axis of the plunger 12 are inserted. You can easily match your mind.

Further, as shown in FIGS. 3 and 4, a fixing screw member 16 is provided at the rear end portion of the rear portion 10B of the base 10. A female screw 16a, which serves as a base-side screw portion, is threaded on the fixing screw member 16, and a hollow feed screw 17 is screwed into the female screw 16a. Further, the fixing screw member 16 is provided with a backlash removing mechanism 18 that removes the backlash generated between the feed screw 17 and the female screw 16a. The backlash removing mechanism 18 has a fixing screw member 16 and an adjusting screw member 19. An elongated hole 16b that is long in the longitudinal direction of the feed screw 17 is formed on the inner peripheral surface of the fixing screw member 16. One of the adjusting screw members 19 has a long hole 16
a protrusion 19 which is inserted into the slot b and is movable along the long hole 16b.
A is provided. By inserting the projection 19A into the long hole 16b, it is possible to prevent the adjusting screw member 19 from rotating together with the feed screw 17 when the feed screw 17 is rotated. Further, the fixing screw member 1
A spring 20 which is an elastic member for urging the fixing screw member 16 and the adjusting screw member 19 in a direction of separating the fixing screw member 16 is disposed between the adjusting screw member 19 and the adjusting screw member 6.

The rear rod 12B of the plunger 12 penetrates through the hollow portion of the feed screw 17,
A connecting portion 21 between the feed screw 17 and the plunger 12 is provided on the rear side of the. As shown in FIG. 5, the connecting portion 21 includes a cap 21A, and in the cap 21A, a first bearing 21B that pivotally supports the rear end portion of the rear rod 12B of the plunger 12 is provided. Has been. The first bearing 21B is formed with a substantially conical notch portion 21a, and the rear end portion of the rear rod 12B of the plunger 12 is formed in a substantially conical shape having the same shape as the notch portion 21a. The rear end portion of the rear rod 12B is fitted into the notch portion 21a, and the rear end portion of the rear rod 12B of the plunger 12 is pivotally supported while being pressed.
In this way, by pivotally supporting the rear rod 12B of the plunger 12 while pressing it, the responsiveness when moving the plunger 12 in the front-rear direction becomes excellent. Further, in the cap 21A, a second bearing 21C that pivotally supports the side surface of the plunger 12 is also provided. With this second bearing 21C, the plunger 1
The plunger 12 is rotatably supported so that the axis of 2 does not shift.

Further, the cap 21A in the connecting portion 21
The rear end portion of the feed screw 17 is fixedly connected to the rear portion 10B of the base 10 via an operation handle 22 having a substantially hollow cylindrical shape with one surface open. As shown in FIGS. 1 and 2, the operation handle 22 includes a scale 22A.
The scale 22A indicates the amount of the injection liquid I (FIG. 3) to be sucked or injected.

The front portion 10A and the rear portion 10B of the base 10 are also
As shown in FIG. 6, a height adjusting mechanism 23 for adjusting the height of the base 10 is provided between them. The height adjusting mechanism 23 includes elongated holes 23A, 23A formed in the front end portion of the rear portion 10B of the base 10 in the height direction and the front portion 10 of the base 10.
It is composed of bolts 23B and 23B for fastening A to the rear portion 10B. Then, by changing the height position at which the bolts 23B, 23B are tightened, the syringe 1
According to the diameter of 1, the height of the base 10 can be adjusted.

On the other hand, an injection liquid inlet / outlet port 11B is provided at the tip of the syringe 11. At the injection liquid inlet / outlet port 11B, as shown in FIG.
One end of the flexible hose H is connected to the flexible hose H.
The other end of is connected to a micropipette 32 via a holder 31 in the suction / injection unit 3. Holder 3
As shown in FIG. 1, reference numeral 1 denotes a micromanipulator M that is movable in three-dimensional directions of X-axis direction, Y-axis direction, and Z-axis direction.
It is configured to be gripped by the microtool attachment portion a and movable in three-dimensional directions of the X-axis direction, the Y-axis direction, and the Z-axis direction. Then, the injection liquid I filled in the syringe 11 is
And is discharged from the injection liquid inlet / outlet port 11B, and by the suction action generated when the plunger head 13 moves backward, the injection liquid inlet / outlet port 11B
It comes from B.

The front position of the syringe 11 is at the base 1.
It is protected from dust and the like by the protection member 24 fixed to the front part 10A of 0. As shown in FIG. 2, a stopper 25 is provided at the front position of the rear portion 10B of the base 10 to prevent the syringe 11 from moving back and forth. Further, when the microinjector 1 is used, it is fixed to the mounting table 26 as shown by a virtual line in FIG.

Next, the procedure of the suction / injection operation of the microinjector M according to the present invention and the operation at that time will be described. When performing the suction / injection operation, the injection liquid is stored in a petri dish such as a microscope (not shown) of the micropipette 32 in the suction / injection unit 3 shown in FIG. 1, and the sample is put therein. Then, by operating the operation unit 2, the injection liquid inlet / outlet port 11
By injecting / injecting the injection liquid I via B, a sample in a petri dish or the like is aspirated, or the aspirated sample is injected into another sample.

Before explaining these suction / injection operations,
A procedure for assembling the operation unit 2 will be described. First, as shown in FIG. 2, the front portion 10A and the rear portion 10B of the base 10 are connected by the bolts 23B and 23B in the height adjusting mechanism 23. The base 1 is connected according to the size (diameter) of the syringe 11.
The bolts 23B and 23B are tightened at appropriate height positions of the long holes 23A and 23A formed in the rear portion 10B of 0. In this way, the base 10 is connected.

Next, the rear rod 1 in the plunger 12
2B, the front connecting portion 12C formed at the rear end portion of the front rod 12A is clamped by the male screw of the rear connecting portion 12D formed at the front end portion and the female screw member 12E. In this way, the plunger 12 is assembled so that it is aligned.

Subsequently, the syringe 11 is placed in the groove formed in the front portion 10A of the base 10 with the plunger 12 being moved backward. Subsequently, the plunger 12 is attached to the syringe 1.
The plunger 12 is inserted into the syringe 11 by advancing relative to the syringe 1. Then, the rear end portion of the syringe 11 is brought into contact with the stopper 25 in the front portion 10A of the base 10, and the syringe 11 is tightened by the tightening member 11A. In this way, the syringe 11 is fixed to the base 10. At this time, since the outer surface of the syringe 11 is polished and smoothed, the syringe 11 is arranged at a predetermined height position with high accuracy. When fixing the syringe 11 to the base 10, as shown in FIG.
It is fitted in the rear end of the syringe 11 and the axis of the syringe 11 and the plunger 1
Align the two axes. In this way, the operation unit 2
Is completed.

Next, the suction operation of the injection liquid I will be described. When the operator picks up the operation handle 22 of the operation portion 2 and rotates it, for example, in the clockwise direction, the operation handle 22, the connection portion 21, and the feed screw 17 are provided. Rotates. Here, since the feed screw 17 is screwed into the female screw 16a of the fixing screw member 16, the feed screw 17 rotates so that the feed screw 17 moves backward relative to the base 10. When the feed screw 17 moves backward, the plunger 12 connected to the feed screw 17 via the connecting portion 21 moves backward in the same direction as the feed screw 17.

At this time, the feed screw 17 and the fixing screw member 1
Backlash occurs between the female screw 16a of No. 6 and
In this embodiment, a backlash removing mechanism 18 is provided. The operation of the backlash removing mechanism 18 will be described. The spring 20 biases the fixing screw member 16 and the adjusting screw member 19 in the direction of separating from each other to remove the backlash. And the feed screw 17
When the screw is rotated, the feed screw 17 moves forward and backward relative to the fixing screw member 16. At this time, the fixing screw member 1
6 does not change the distance between the adjusting screw member 19 and
It is only slightly changed to eliminate the backlash that occurs on the lead screw 17. Therefore, the fixing screw member 16 and the adjusting screw member 19 always have a substantially constant biasing force.
Since the urging force is applied between the feed screw 17 and the fixing screw member 16, the backlash between the feed screw 17 and the fixing screw member 16 can be reliably removed. Therefore, the feed screw 17 and the feed screw 1
The plunger 12 connected to 7 can be moved with high precision. Further, at the connecting portion 21, the plunger 1
Since the first bearing 21B that pivotally supports while pressing 2 is provided, the response of the movement of the plunger 12 is also good.

The plunger 12 is moved backward by rotating the feed screw 17.
If the axes of 1 and the plunger 12 are deviated from each other, the plunger 12 may be caught by the syringe 11 and may not move. In this respect, in the present embodiment, since the feed screw 17 and the plunger 12 are connected behind the feed screw 17, the situation in which the plunger 12 cannot move can be extremely reduced. The parallel stability associated with the displacement of the axial center of the plunger 12 is determined by the distance between the point where the O-ring 14 contacts the inner surface of the syringe 11 and the point where the plunger 12 is connected to the feed screw 17.

That is, as schematically shown in FIG. 7B, when the connecting portion 56 between the feed screw 55 and the plunger 53 is located in front of the feed screw 55 as in the conventional microinjector 50 shown in FIG. Has two O-rings 54,
The distance L1 between the center point P where 54 contacts the inner surface of the syringe 52 and the point Q where the plunger 53 is connected to the feed screw 55 is short. Therefore, if the axis of the syringe 52 and the axis of the plunger 53 are deviated from each other, the angle θ1 between the axis of the syringe 52 and the axis of the plunger 53 increases with the backward movement of the plunger 53. Therefore, especially when the plunger 53 is located rearward, the angle of the axial center of the syringe 52 and the plunger 5
The angle between the three axes becomes large, the plunger 53 cannot move smoothly, and further the plunger 53 cannot move. Moreover, the two O-rings 54,
Since 54 is provided, the smooth movement of the plunger 53 is obstructed.

On the other hand, as in the present embodiment, the connecting portion 21 between the feed screw 17 and the plunger 12 has the feed screw 17
7A, the point R where the O-ring 14 is in contact with the inner surface of the syringe 11 and the center point S where the plunger 12 is connected to the feed screw 17 are shown in FIG. 7A. The distance L2 between and becomes long. For this reason,
Even if the axial center of the syringe 11 and the axial center of the plunger 12 are deviated from each other, as the plunger 12 moves backward,
The ratio of the increase in the angle θ2 between the axis of and the axis of the plunger 12 is low. Even when the plunger 12 is located rearward, the angle θ2 between the axis of the syringe 11 and the axis of the plunger 12 does not become so large that the plunger 12
Can move sufficiently smoothly, though it becomes a little difficult to move. Moreover, since there is only one O-ring 14, the plunger 12 can be moved more smoothly. Furthermore, when the operating portion 2 is assembled, the plunger 12 can be operated sufficiently smoothly by aligning the syringe 11 and the plunger 12 accurately to some extent without being strictly concentric. Therefore, the work for assembling the operation unit 2 becomes very easy.

Thus, when the plunger 12 moves backward,
The plunger head 13 also moves backward, and the injection liquid I flows into the syringe 11 from the micropipette 32 via the flexible hose H. At this time, the sample in the injection liquid I stored in the petri dish or the like is sucked into the micropipette 32.

On the contrary, when performing the injection work, the worker
The operation handle 22 is rotated counterclockwise, for example.
Then, the plunger 12 moves forward together with the feed screw 17. At this time, the plunger 12 can be moved with high accuracy and smoothly, and the responsiveness of the movement of the plunger 12 is good as in the case of moving the plunger 12 backward. Thus, the operation of injecting the sample sucked into the micropipette 32 into another sample by the suction operation is performed.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, the backlash mechanism may be provided without providing the connection portion between the feed screw and the plunger behind the feed screw, or conversely, the connection portion between the feed screw and the plunger may be provided behind the feed screw without the backlash mechanism. It may be provided. Preferably, the connecting portion is provided with a first bearing that pivotally supports the rear end portion of the plunger and a second bearing that pivotally supports the vicinity of the rear portion of the plunger. It is also possible to adopt a mode in which the bearing is not attached. Furthermore, O
Two rings may be provided, or no guide member may be provided. Further, although a metal syringe is suitable as the syringe, a mode in which a glass syringe is used can be adopted, and it is desirable to polish the outer surface of the syringe, but a mode in which the outer surface of the syringe is not polished can also be adopted.

[0050]

As described above, claim 1 of the present invention
According to the invention according to, even if the axis of the plunger is inclined with respect to the axis of the syringe, the influence of the inclination on the angular deviation between the axis of the syringe and the axis of the plunger is reduced, The plunger can be moved smoothly.
Further, the plunger can be made to move smoothly without arranging the plunger concentrically with the syringe with high accuracy. According to the second aspect of the present invention, it is possible to eliminate the play separating the bearing and the plunger in the longitudinal direction of the plunger. Therefore, the response of the plunger to the movement of the feed screw can be made very good. You can According to the invention of claim 3 , since only one O-ring is attached, the plunger can be moved smoothly with respect to the syringe even if the axis of the syringe is slightly deviated from the axis of the plunger. it can. According to the invention of claim 4 , the axis of the syringe can be easily aligned with the axis of the plunger. According to the invention of claim 5 , since the syringe can be attached to the base with high accuracy, it is easy to dispose the plunger concentrically with the syringe. In addition, the microinjector can be moved smoothly and highly accurately accordingly. According to the invention of claim 6 , it is difficult to break and the plunger can be moved more smoothly.

[Brief description of drawings]

FIG. 1 is a perspective view of a microinjector according to the present invention.

FIG. 2 is an exploded perspective view of an operating portion of the microinjector according to the present invention.

FIG. 3 is a side sectional view of an operating portion of the microinjector according to the present invention.

4A is an enlarged sectional view of a backlash removing mechanism of a microinjector according to the present invention, and FIG. 4B is a sectional view taken along line IV-IV of FIG.

FIG. 5 is an enlarged cross-sectional view of a connecting portion between the feed screw and the plunger of the microinjector according to the present invention.

6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 (a) is an explanatory view for explaining the action of the connecting portion between the plunger and the feed screw of the microinjector of the present invention provided behind the feed screw, and FIG. 7 (b) is the action of the conventional microinjector. It is an explanatory view explaining.

FIG. 8 is a side sectional view of a conventional microinjector.

[Explanation of symbols]

1 micro injector 2 operation part 3 Suction / injection section 10 bases 11 syringes 12 Plunger 13 Plunger head 14 O-ring 15 Guide member 16 Fixing screw member (backlash removal mechanism) 16a Female screw (base side screw part) 16b long hole 17 Lead screw 18 Backlash removal mechanism 19 Adjustment screw member (backlash removal mechanism) 19A protrusion 20 springs (backlash removal mechanism) 21 Connection 21B 1st bearing 21C 2nd bearing 22 Operation handle 23 Height adjustment mechanism 25 stopper

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 2000-10016 (JP, A) JP 10-47451 (JP, A) JP 7-171214 (JP, A) JP 63-35263 (JP, A) JP 2000-107288 (JP, A) JP JP 11-70435 (JP, A) Actual opening Sho 53-42498 (JP, U) Actual opening Sho 61-38369 (JP, U) Special table Flat 8-510392 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61M 5/145 F16H 25/24

Claims (6)

(57) [Claims] 1. A microinjector comprising an operating part and a suction / injecting part, wherein the operating part has a plunger inserted into a syringe fixed to a base, and slides along an inner surface of the syringe. A plunger head to which a ring is attached is attached to the tip of the plunger, and a feed screw is screwed into a base side screw portion formed on the base, the feed screw being connected to the rear portion of the plunger. In addition, it is possible to move forward and backward relative to the base by rotating, and the connecting portion between the feed screw and the plunger is provided behind the feed screw. And a microinjector. 2. The connecting portion is provided with a first bearing that pivotally supports a rear end portion of the plunger and a second bearing that pivotally supports a side surface of the plunger. The microinjector according to claim 1 , wherein: 3. The O-ring is attached to the plunger head only once.
The microinjector according to claim 1 or 2 . 4. The microinjector according to claim 3 , further comprising a guide member for adjusting the plunger to be concentrically arranged with respect to the syringe. 5. Of the outer surface of the syringe, microinjector as claimed in any one of claims 4, characterized in that part in contact with at least the base is polished. 6. The microinjector according to any one of claims 1 to 5 , wherein the syringe is a metal syringe.