JPH1033672A - Engaging and disengaging mechanism of syringe pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive transmitting mechanism, in which the transmission efficiency can be improved and sure engagement and disengagement are enabled in a syringe pump. SOLUTION: A syringe pump engagement and disengagement mechanism comprises a feed screw 3, and a driven member 5 movably fitted to the feed screw, wherein the driven member is provided with a geared rotator 4 which can be rotated independently of the member 5 and a locking member 15 for locking the rotation, and further, a through hole 12 where a screw screw- engaged with the feed screw is formed in the central part of the rotator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an infusion device for injecting a drug solution into a patient using a syringe, and more particularly to a syringe pump.

[0002]

2. Description of the Related Art An infusion device is used when a medicinal solution must be infused into a patient at a predetermined infusion rate, and a syringe pump is often used when the infusion amount is small or the infusion speed is low. Is done. The rear end of the piston of the syringe is in contact with a pressing portion (hereinafter, referred to as a slider) of the syringe pump, and the movement of the slider presses the piston of the syringe, thereby injecting the liquid medicine in the syringe into the patient. The movement of the slider is performed by converting the rotation of the motor into an axial movement of the screw by a feed screw. Since the syringe must be set in the syringe pump or removed from the syringe pump before or after the injection of the drug solution, it is necessary that the slider can be freely moved from the rear end of the piston. For this reason, in the syringe pump, the slider is not always linked with the feed screw, but the link must be cut off if necessary. In a conventional syringe pump, the half nut 24 as shown in FIG. 5 plays a role of interlocking and disconnecting the feed screw and the slider.
By attaching and detaching the motor 5, the drive of the motor is transmitted to the slider or cut off. However, when engaging and disengaging with the feed screw using a half nut, there are various problems as follows, and improvement has been desired.

In a drive transmission mechanism using a half nut, the engagement itself between the feed screw and the screw formed on the half nut is imperfect, so that the half nut used in the syringe pump and the half nut used for engagement therewith are not provided. A trapezoidal screw with good transmission efficiency could not be used for the feed screw. This is because the half nut is not a complete screw, but a half-split nut is pressed from both sides by springs, etc., so the engagement itself is incomplete, and if excessive force is applied to the feed screw, the spring will There is a danger that the engagement of the screw may be disengaged due to being unable to withstand the stress. For this reason, the engagement is difficult to be disengaged with the conventional syringe pump, but it is necessary to use a square screw having a low drive transmission efficiency due to the screw. In addition, the square screw has a higher manufacturing cost than the trapezoidal screw, which is a factor of cost increase. However, half nuts have been used for a long time because there is no other suitable mechanism for engaging and releasing the feed screw of the syringe pump and the slider.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an engagement / disengagement mechanism of a syringe pump which can easily and reliably transmit a drive source to a slider and release it. Another object of the present invention is to provide an inexpensive syringe pump provided with such an engagement / disengagement mechanism.

[0005]

According to the present invention, there is provided an engagement / disengagement mechanism comprising a feed screw and a driven body movably fitted on the feed screw, wherein the driven body includes a driven screw. A rotating body that can rotate independently of the body is provided, a through hole through which a feed screw penetrates is formed at the center of the rotating body, and a screw that can be screwed to the feed screw is formed in a bore of the through hole, and the rotating body is rotated. The syringe pump is characterized in that a gear that rotates integrally with the rotating body is disposed on a side of the body, and a locking member that locks the rotation of the rotating body is provided on the driven body. The above problem has been solved by an engagement / disengagement mechanism. The syringe pump further includes the engagement / disengagement mechanism, a housing that bridges the feed screw, a slider that presses a rear end of a piston of the syringe, and a connecting member that connects the driven body and the slider. The syringe pump has an operation unit for engaging / disengaging the driven body with the feed screw, and an interlocking unit for interlocking the locking member and the operation unit. did.

When the driven body of the apparatus is engaged with the feed screw, that is, when the rotation member is prevented from free rotation by the locking member, the rotation of the feed screw causes the rotary body to move in the axial direction. Then, the driven body also moves accordingly.
As a result, the slider connected to the driven body by the connecting member also moves in the same direction in conjunction with it. This state is the injection mode, in which the slider is moved by the above mechanism to inject the liquid medicine in the syringe. Next, when the driven member is disengaged from the feed screw, that is, when the locking member is released, the rotation of the rotating body is free, and even when the feed screw rotates, it is screwed (to the feed screw). The rotating body that is present only rotates on the spot, and the driven body does not rotate in conjunction with the rotating body and remains on the spot. In this state, the slider or the driven body can be moved by the feed screw by pushing the slider by hand, so that the slider can be freely moved in accordance with the rear end of the syringe. . This state is the non-injection mode, which is selected when the syringe is attached to or detached from the device before or after the injection. In other words, the rotating body mounted on the driven body is always screwed to the feed screw, but the locking body can engage or disengage the rotating body and the driven body. As a result, it becomes possible to transmit the drive of the motor or the like to the slider or to cut off the drive. And in the release state,
The slider can be moved in the axial direction.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A syringe pump 1 according to the present invention is shown in FIG.
As shown in the figure, mainly a housing 2, a feed screw 3 laid on the housing 2, a driven body 5 which can be engaged / disengaged with the feed screw 3 via a rotating body 4, and a piston rear end of a syringe. A slider 6 for pressing the portion and a connecting member 7 for connecting the driven body 5 and the slider 6 are provided. Both ends of the housing 2 include a support portion 8 that rotatably supports the feed screw 3 and a through portion 9 that is penetrated by the connecting member 7 to allow the connecting member 7 to move in the axial direction and to support the connecting member 7 at the same time. Have. The housing 2 is provided with a space for mounting the syringe on the upper part thereof, and is long enough to move the driven body 5 along the feed screw 3 inside the housing, that is, longer than the stroke length of the piston in the syringe. It is only necessary to have a width and a height, for example, a length of 130 to 200 mm, a width of 45 to 65 mm, and a height of 50 to 7
A metal having a size of 0 mm and a thickness of 3 to 6 mm is suitable. The support portion 8 may support the feed screw 3 at both ends without fixing the feed screw 3 so that the feed screw 3 does not come off the housing 2, and the shape is not particularly limited. However, it is preferable that the support portion 8 be made of a material that can smoothly rotate the feed screw 3 and that is not easily worn by the rotation. The penetrating portion 9 is mainly provided to move the connecting member 7 in the axial direction, but has another purpose of supporting the connecting member 7 by the housing 2. The diameter of the hole of the penetrating portion 9 only needs to be able to penetrate the connecting member 7, but if it is larger than the diameter of the communicating member, it will not function as a support.

The feed screw 3 is connected to a drive source (not shown) such as a motor, and the number of rotations can be adjusted by interposing a reduction gear or the like to reduce the rotation of the motor. The length of the feed screw 3 is regulated by the housing 2, and conversely, the length of the housing 2 is also limited by the length required for the feed screw 3. Although the thickness of the feed screw 3 is not particularly limited, it is not preferable that the feed screw 3 is too thin for the purpose of moving the driven body 5 while supporting it. Conversely, if the feed screw 3 is too thick, the rotating body 4 and the driven body 5 also become large. Is difficult to use. Usually, a diameter of 6 to 10 mm is easy to use. The type of the feed screw 3 is not limited to a square screw as in the related art, and a trapezoidal screw or a triangular screw can also be used. Unlike these square screws, these screws can be formed by rolling, so that the cost can be reduced. FIG.
As shown in (1), the lead of the feed screw 3 (the distance the driven body 5 moves according to the cycle of the screw) is preferably 10 to 15 mm, and if too small, the driven body is released when the feed screw and the driven body are released. Cannot move smoothly (movement efficiency by rotation decreases). Conversely, even if the lead is too large, the reduction ratio, which is the ratio for reducing the rotation of the motor, becomes large, and many reduction means are required.

A rotating body 4 equipped with a ball bearing is fitted in the center of the driven body 5, and the rotating body 4 can rotate independently of the driven body 5. The lower part of the driven body 5 is connected to one end of the connecting member 7. A through-hole 12 is formed in the center of the rotating body 4, and a female screw that can be screwed with a feed screw is formed in a bore of the through-hole 12. Since the female screw is limited to be screwed to the feed screw 3, a trapezoidal screw can be used as a type, although not particularly described in detail. The feed screw 3 is inserted into the through hole 12 of the rotating body 4 in a state where a male screw (of the feed screw 3) is screwed into the female screw. A gear 14 is formed on one side of the rotating body 4 so as to be able to rotate integrally with the rotating body 4. The gear 14 may be formed integrally with the rotating body 4, or may be formed by combining separate components by mechanical means. As shown in FIG. 3, a locking member 15 is provided below the driven body 5 on the side where the gear 14 exists so as to lock the rotation of the gear 14. The locking member 15 has only one end connected to the axis 16 and is mounted on the driven body 5 so that the locking member 15 can rotate around the axis 16. The locking member 15 is rotated. By engaging the protruding pawl 17 with the groove of the gear 14, the rotation of the rotating body 4 (gear) is prevented. As will be described later, the locking member 15 is connected to the operating portion 18 of the slider 6 by an axis 16 disposed in the inner cavity of the connecting member 7.
At 8, the locking member 15 can be operated.

The slider 6 and the driven body 5 are connected by a hollow rod-shaped connecting member 7, and the movement of the driven body 5 in the axial direction is transmitted to the slider by the connecting member 7. As described above, the connecting member 7 passes through the through portion 9 of the housing 2, and the connecting member 7 moves while sliding through the through portion 9. An axis 16 is inserted into the lumen of the connection member 7, and the axis 16 connects the operation portion 18 of the slider 6 and a part of the locking member 15. Therefore, the locking member 15 can be remotely operated by operating the operation section 18 of the slider 6. For example, as shown in FIG. 4, the operating unit 1 having one end connected to the axis 16 similarly to the locking member 15.
When the lever 19 (hereinafter referred to as a clutch lever) 19 is rotated, its movement is transmitted by the axis 16, and the locking member 15 is also rotated (in conjunction with it) to release the gear 14 whose rotation has been prevented. Let it. That is, the locking member 15 is
, The rotation of the rotating body 4 on the feed screw 3 is locked, so that the driven body 5 cannot move freely along the feed screw.
The lock is released by rotating 5. As described above, the connecting member 7 needs to have a predetermined thickness because the axis 16 enters the inner cavity. The slider 6 is connected to one end of a connecting member 7 opposite to the housing. One end of the clutch lever 19 is connected to the axis 16, and the other end of the clutch lever 19 is regulated by a spring 20 so that the axis 16 does not rotate freely (FIG. 4).

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partial schematic view of a syringe pump 1 of the present invention. For easy understanding, the shape, dimensions, and the like are described for each of the main components of the syringe pump 1. The housing 2 is made of aluminum having a thickness of 6 mm and a length of 150 mm.
mm, a width of 55 mm, and a height of 60 mm. Support portions for the feed screw 3 are formed at both ends. A feed screw receiver 21 made of polyacetal is mounted on the support portion. A moving hole for penetrating the connecting member 7 as a penetrating portion 9 is formed below the supporting portion at one end of the housing 2. The feed screw 3 has a diameter of 8 mm and a length of 160 mm, and a trapezoidal screw is used as a screw type. As shown in FIG. 2, the lead of the screw is 12 mm. The driven body 5 is a rectangular parallelepiped made of aluminum having a length of 12 mm, a width of 43 mm, and a height of 50 mm, and has a hole near the upper center for fitting the rotating body 4. The rotating body 4 fitted with a bearing is fitted into this hole. A through hole 12 is formed in the center of the rotating body 4, and the through hole 1
A female screw is formed in the second lumen so as to be screwed to the feed screw 3. As the type of the female screw, a trapezoidal screw can be used similarly to the feed screw 3. A gear 14 is provided on one side of the rotating body 4, and the gear 14 is fixedly joined to the rotating body 4 by bolts and nuts so as to be able to rotate integrally with the rotating body 4. One end of the driven body 5 is connected to the axis 16
Is provided, and the locking member 15 has a claw 17 of about 7 mm protruding in one direction [FIG. 3]. The connecting member 7 has a length of 180 mm and a diameter of 11 mm
Stainless steel hollow conduit having a locking member 1
An axis 16 for interlocking the clutch lever 5 with the clutch lever 19 is provided. The slider 6 is connected to an end of the connecting member 7 opposite to the housing, and an operation portion 18 is provided on a surface of the slider 6 opposite to the syringe pressing surface. The operation section 18 is provided with a clutch lever 19 having a length of 40 mm and one end of which is connected to the axis 16 at right angles. The lever 19 made of polyacetal is regulated by a spring 20 attached to one end of the lever to prevent the clutch lever 19 from rotating without permission [FIG. 4]. The slider 6 is made of a stainless plate having a height of 55 mm, a width of 36 mm, and a thickness of 2.5 mm, and an operation assisting portion 23 is provided at a right angle on a side of the plate.

Next, an operation method and an operation mechanism of the apparatus 1 will be described. First, a syringe is placed on the housing 2. The locking member 15 is moved to the gear 1 by the lever 19 of the operation unit 18.
4 to bring the rotating body 4 into a release state. Then, the rotating body 4 screwed to the feed screw 3 can be moved by rotating along the screw, and by pushing the driven body 5 or the slider 6 by hand, the movement of both in the axial direction is prevented. Will be possible. In this state, the slider 6 is moved in the axial direction while adjusting the position of the slider 6 to be at the rear end of the piston of the syringe (non-injection mode). Further, in this state, since the rotating body 4 rotates independently in the driven body 7, the driven body 5 remains in place even when the feed screw 3 rotates. That is, the feed screw 3 and the driven body 5 are in the released state, and their movements are not transmitted. When the positioning of the slider 6 is completed, the locking member 15 is moved to the gear 14.
To prevent free rotation of the rotating body 4. Therefore, the driven body 5 cannot move freely as in the non-injection mode. That is, since the rotating body 4 cannot rotate independently of the driven body 5, the driven body 5 moves in the axial direction by the rotation of the feed screw 3, and the slider 6 also moves. Then, the injection mode is set, and the injection amount, injection speed, time, and the like are set. In this mode, unlike the non-injection mode, since the feed screw 3 and the driven body 5 are in the engaged state, the rotation of the motor is transmitted to the feed screw 3. The rotation of the feed screw 3 is transmitted to the slider 6 as the movement of the driven body 5 in the axial direction (injection mode). When the injection of the chemical is completed, the locking member 1
Release of 5 puts the device back into non-injection mode. Then, the slider 6 is moved to take out the set syringe from the apparatus.

[0013]

According to the device of the present invention, the engagement between the drive source and the driven body is ensured, and there is no possibility that the engagement will be released even when a large load is applied to the slider. In addition, the types of screws that can be selected are increased, and the manufacturing cost can be reduced. Further, the transmission efficiency in the drive transmission mechanism is increased, and energy consumption can be saved. In addition, since the motor itself can be made smaller, it is useful for downsizing the product.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of an engagement / disengagement mechanism (hereinafter, abbreviated as “this device”) of a syringe pump of the present invention, as viewed from a bottom surface direction.

FIG. 2 is an enlarged view showing a screw portion of a feed screw of the present apparatus.

FIG. 3 is a schematic view of a driven body as viewed from a gear side in the apparatus.

FIG. 4 is a schematic diagram showing the back side of the syringe pressing surface of the slider of the present invention.

FIG. 5 is a schematic view of a conventionally used half nut.

[Explanation of Codes] Syringe pump 2. Housing 3. Feed screw 4. Rotating body 5. Driven body 6. Slider 7. Connection member 8. Support part 9. Penetration part 12. Through hole 14. Gear 15. Locking member 16. Axis 17. Nails 18. Operation unit 19. Clutch lever (lever) 20. Spring 21. Feed screw receiver 23. Operation auxiliary unit 24. Half nut 25. Feed screw 26. Spring

Claims (9)

[Claims] An engagement / disengagement mechanism comprising a feed screw and a driven body movably fitted on the feed screw, wherein the driven body has a rotatable rotation independently of the driven body. A body is provided, a through hole through which a feed screw passes is formed at the center of the rotating body, a screw that can be screwed to the feed screw is formed in a bore of the through hole, and a rotating body is formed at a side portion of the rotating body. An engagement / disengagement mechanism for a syringe pump, wherein a gear that rotates integrally is provided, and a driven member is provided with a locking member that locks the rotation of the rotating body. 2. The engagement / disengagement mechanism for a syringe pump according to claim 1, wherein a lead of a screw formed on the feed screw has a length of 10 to 15 mm. 3. The engagement and engagement of the syringe pump according to claim 1, wherein one of the feed screw and the screw formed in the bore of the through hole is a trapezoidal screw.
Release mechanism. 4. The engagement / disengagement mechanism for a syringe pump according to claim 1, wherein the locking member comes into contact with the gear by rotation of the locking member. 5. The engagement / disengagement mechanism for a syringe pump according to claim 1, wherein rotation of the rotating body independent of a driven body is performed by a ball bearing mounted on the rotating body. . 6. The engagement / disengagement mechanism according to claim 1, a housing that bridges the feed screw, a slider that presses a piston rear end of a syringe,
A syringe pump having a connecting member for connecting the driven body and a slider, wherein the syringe pump is capable of interlocking an operating part for engaging and disengaging the driven body with a feed screw, and a locking member and the operating part. A syringe pump comprising an interlocking means. 7. The syringe pump according to claim 6, wherein the operation section is provided on a slider. 8. The syringe pump according to claim 6, wherein the interlocking means is provided in a lumen of the connecting member. 9. The method according to claim 6, wherein the engagement / disengagement by the operation unit is based on rotation of a lever, and the free rotation of the lever is limited by a spring. Syringe pump.