JP2011083476A - Medical opening/closing forceps - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical opening/closing forceps in which opening/closing pieces can be opened/closed without pressing a wire for operating the opening/closing pieces toward an opening/closing one side. <P>SOLUTION: The medical opening/closing forceps include: a pair of the opening/closing pieces 32, 37; operation means 13, 15 for pulling one of a first traction wire and a second traction wire toward a proximal end side and, at the same time, allowing the other to be pulled toward distal end side; and power transmission mechanisms 18, 29, 36, 41 and W3 which connect the distal end parts of the first traction wire and the second traction wire to a pair of the opening/closing pieces, and which pull the second traction wire to the distal end side and move both opening/closing pieces in the closing direction when the first traction wire is pulled to the proximal end side, and which pull the first traction wire to the distal end side, and move both of the opening/closing pieces in the opening direction when the second traction wire is pulled to the proximal end side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a medical open / close forceps including a pair of open / close pieces at a distal end.

As conventional examples of medical open / close forceps capable of grasping or cutting an affected part or the like, for example, there are those described in Patent Document 1 and Patent Document 2.
These open / close forceps include a pair of open / close pieces provided at the distal end, an operation wire having the distal end linked directly or indirectly to the pair of open / close pieces, and a slide-type operation means in which the proximal end of the operation wire is connected. And.
When the operating means is slid to the base end side (rear), the operating wire is pulled rearward to close the pair of opening / closing pieces, and when the operating means is slid to the front end side (forward), the operating wire is pushed forward. A pair of opening and closing pieces opens. And an affected part can be hold | gripped or cut | disconnected by closing a pair of opening-and-closing piece.

JP 2008-194068 A JP 05-031120 A

In each of the open / close forceps disclosed in the above publication, a pair of open / close pieces is opened by sliding the operating means toward the distal end and pushing the operating wire forward.
However, since the operation wire tends to buckle when pressed, the force applied to the operation means is not transmitted to the open / close piece reliably (play occurs), or the movement amount when the open / close piece opens is closed. There is a risk that it will be smaller than the amount of movement. In particular, when the open / close type forceps having flexibility as a whole is bent, the operation wire is bent, so that there is a high possibility that such a problem will occur.

  An object of the present invention is to provide a medical open / close forceps capable of opening / closing an open / close piece without pushing a wire for operating the open / close piece toward the open / close piece side.

  The medical open / close type forceps of the present invention pulls a pair of open / close pieces provided at the distal end, the first pulling wire and the second pulling wire, and one of the first pulling wire and the second pulling wire to the proximal end side. At the same time, operating means that allows the other to be pulled toward the distal end side, the distal ends of the first pulling wire and the second pulling wire, and the pair of open / close pieces are connected. The first pulling wire is pulled toward the proximal end side. When the second pulling wire is pulled to the distal end side, both the opening and closing pieces are moved in the closing direction, and when the second pulling wire is pulled to the proximal end side, the first pulling wire is moved to the distal end side. And a power transmission mechanism that moves both opening and closing pieces in the opening direction.

A first wire guide formed on each of the pair of opening and closing pieces, a position where the distal end of the first pulling wire is fixed, and the power transmission mechanism is positioned between the opening and closing pieces and the operating means; A first moving member that can move in a direction approaching the operating means, and a position where the tip of the second puller wire is fixed is positioned between the opening and closing piece and the operating means, and approaches the opening and closing piece and approaches the operating means. And a second moving member having a second wire guide, both ends fixed to the first moving member, a central portion is wound around the second wire guide of the second moving member, and the central portion And an opening / closing wire that is hung around the first wire guide of the pair of opening / closing pieces.
In this case, it is preferable that gears having the same module and the same number of teeth meshing with each other are formed at the facing portions of the pair of opening and closing pieces.

  Further, the power transmission mechanism rotates in a coaxial state with respect to the distal end portion of the first pulling wire, and is connected to one opening / closing piece so as to be rotatable, and can be rotated to the other opening / closing piece. The second link member to be connected, the third link member that rotates coaxially with respect to the distal end portion of the second puller wire, the third link member that is rotatably connected to the one opening / closing piece, and the other opening / closing piece And a fourth link member that can be connected.

In addition, after the first pulling wire and the second pulling wire are coupled, the power transmission mechanism includes a rotatable pulley around which a combined body of the first pulling wire and the second pulling wire is wound, A first rotating gear that rotates together with the pulley, a second rotating gear that is fixed to one of the opening and closing pieces and meshes with the first rotating gear, and a second rotating gear that is fixed to the other opening and closing piece; And a third rotating gear that meshes with each other.
In this case, it is preferable that the second rotating gear and the third rotating gear have the same module and the same number of teeth.

In addition, after the first pulling wire and the second pulling wire are coupled, the power transmission mechanism includes a rotatable pulley around which a combined body of the first pulling wire and the second pulling wire is wound, A first rotation gear that rotates together with the pulley, a second rotation gear that meshes with the first rotation gear, a third rotation gear that meshes with the second rotation gear, and one of the opening and closing pieces, A fourth rotation gear that meshes with the second rotation gear and a fifth rotation gear that meshes with the third rotation gear fixed to the other opening / closing piece may be provided.
In this case, it is preferable that the second rotating gear and the third rotating gear have the same module and the same number of teeth, and the fourth rotating gear and the fifth rotating gear have the same module and the same number of teeth.

According to the present invention, when the operating means is operated, one of the first pulling wire and the second pulling wire is pulled to the proximal end side, and at the same time, the other is pulled to the distal end side. When the first pulling wire is pulled to the proximal end side by the operating means, the power transmission mechanism pulls the second pulling wire to the distal end side and moves both opening and closing pieces in the closing direction. On the other hand, when the second pulling wire is pulled to the proximal end side by the operating means, the power transmission mechanism pulls the first pulling wire to the distal end side and moves both opening and closing pieces in the opening direction.
Thus, when opening and closing the opening / closing piece, the first pulling wire and the second pulling wire are not pushed to the distal end side but pulled to the proximal end side or the distal end side. In addition, the first pulling wire and the second pulling wire do not buckle. Therefore, the force applied to the operating means is reliably transmitted to the opening / closing piece (no play occurs), so that the opening / closing piece opens and closes reliably. Furthermore, the movement amount when the opening / closing piece is opened is not smaller than the movement amount when the opening / closing piece is closed.

  Further, if the paired gears that rotate while meshing in conjunction with the opening and closing operation of the pair of opening and closing pieces are made the same module and the same number of teeth, the pair of opening and closing pieces opens and closes symmetrically.

It is a vertical side view which closes an opening-and-closing piece, and shows an outer tube and a tip case with an imaginary line about an opening-and-closing type forceps of a 1st embodiment of the present invention. It is a vertical side view similar to FIG. 1 when the opening and closing piece is opened. It is a perspective view which removes the outer tube and shows the front-end | tip part of the open / close type forceps with the open / close piece closed. It is a perspective view which abbreviate | omits the front-end | tip case and shows the front-end | tip part of the open / close type forceps with which the open / close piece is closed. It is a bottom view which shows the front-end | tip part of the opening-and-closing type forceps with which the opening-and-closing piece is closed, omitting a sheath tube and a front-end | tip case. It is a side view which abbreviate | omits a skin tube and a front-end | tip case, and shows the front-end | tip part of the open / close type forceps with which the open / close piece is closed. FIG. 6 is a bottom view similar to FIG. 5 when the opening / closing piece is opened. It is a side view similar to FIG. 6 when an opening-and-closing piece opens. It is a vertical side view similar to FIG. 1 of the modification of 1st Embodiment. It is a perspective view which shows the front-end | tip part of the opening-and-closing type forceps of the 2nd Embodiment of this invention, closing an opening-and-closing piece and removing an outer tube. It is a perspective view similar to FIG. 10 when an open / close piece is opened. It is a perspective view of the front-end | tip part of the open-and-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer sheath tube and a front-end | tip case. It is a perspective view similar to FIG. 12 when an opening / closing piece is opened. It is a side view of the front-end | tip part of the open-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer tube | pipe and a front end case. It is a side view similar to FIG. 14 when an opening / closing piece is opened. It is a perspective view which shows the front-end | tip part of the opening-and-closing type forceps of the 3rd Embodiment of this invention, closing an opening-and-closing piece and removing an outer tube. It is a perspective view similar to FIG. 16 when an opening / closing piece is opened. It is a perspective view of the front-end | tip part of the open-and-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer sheath tube and a front-end | tip case. It is a perspective view similar to FIG. 18 when an opening / closing piece is opened. It is a right view of the front-end | tip part of the open-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer tube | pipe and a front end case. It is a right view similar to FIG. 20 when an opening / closing piece is opened. It is a top view of the front-end | tip part of the open-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer tube | pipe and a front end case. It is a perspective view which shows the front-end | tip part of the opening-and-closing type forceps of the 4th Embodiment of this invention, closing an opening-and-closing piece and removing an outer tube. It is a perspective view similar to FIG. 23 when an open / close piece is opened. It is a perspective view of the front-end | tip part of the open-and-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer sheath tube and a front-end | tip case. It is a perspective view similar to FIG. 25 when an opening / closing piece is opened. It is a right view of the front-end | tip part of the open-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer tube | pipe and a front end case. It is a right view similar to FIG. 27 when the opening / closing piece is opened. It is a top view of the front-end | tip part of the open-close type forceps which closes an opening-and-closing piece and abbreviate | omits an outer tube | pipe and a front-end | tip case.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the following description, the front / rear, left / right, and up / down directions are based on the arrow direction shown in the figure.
As shown in FIGS. 1 and 2, the open / close forceps 10 has an elongated shape extending in the front-rear direction. The rear end portion of the open / close forceps 10 is constituted by a rear case 11 which is a cylindrical member made of a hard material (synthetic resin, metal, etc.) and having an open front end. A rotation support shaft 12 extending in the radial direction (left-right direction) of the rear case 11 is fixed inside the rear case 11, and a long hole (not shown) extending in the front-rear direction is formed on the upper surface of the rear case 11. is there. The rotation support shaft 12 supports a lower end portion of an operation lever (operation means) 13 having a finger hooking hole 14 at the upper end portion in a rotatable manner, and the upper end portion of the operation lever 13 passes through the long hole and is located in the rear case. 11 is located above (outside). The operation lever 13 is rotatable between a closing operation position shown in FIG. 1 and an opening operation position shown in FIG.

  A rotation lever (operation means) 15 integrated with the operation lever 13 (non-relatively rotatable) 15 is rotatably supported on the rotation support shaft 12, and both ends of the rotation lever 15 are substantially in the front-rear direction. The rear ends of the first pulling wire W1 and the second pulling wire W2 made of metal that extend and have the same length are fixed to each other. The front end of the first pulling wire W1 is fixed to a first moving member 18 that is a cylindrical metal member. As shown in the drawing, the first moving member 18 is formed with a guide support hole 19 having a circular cross section penetrating the first moving member 18 in the front-rear direction at a position deviated from the center. As shown in FIG. 3 and the like, the periphery of the first moving member 18 is covered with a metallic and cylindrical tip case 22 extending in the front-rear direction, and the front end portion of the rear case 11 and the rear end portion of the tip case 22 are covered. Are made of a flexible material such as rubber, and the front and rear ends of the outer tube 21 positioned around the first pulling wire W1 and the second pulling wire W2 are respectively connected (fixed). Since the pair of left and right guide pins 20 fixed to the first moving member 18 are fitted in the pair of guide long holes 23 formed on the left and right of the rear portion of the tip case 22, the first moving member 18 is connected to the tip case 22. On the other hand, it can slide in the front-rear direction and cannot rotate around the axis of the tip case 22. As shown in FIG. 4 and the like, the rear part of the second moving member 29 made of metal is slidably fitted in the guide support hole 19 of the first moving member 18, and the second moving member 29 has a rear end at the rear end. 2 The front end of the pulling wire W2 is fixed. A pair of upper and lower guide pins 30 are integrally formed at the front end portion of the second moving member 29, and the upper and lower guide pins 30 are respectively fitted into a pair of guide long holes 24 formed above and below the tip case 22. Therefore, the second moving member 29 is slidable in the front-rear direction with respect to the tip case 22 and is not rotatable about the axis of the tip case 22. Further, a wire guide (second wire guide) 28 having a circumferential wire guide groove is fixed to the peripheral surface of the lower guide pin 30.

A pair of left and right slits 25, a pair of upper and lower rotation support holes 26 provided at the left end, and a pair of upper and lower rotation support holes 27 provided at the right end are formed in the front portion of the tip case 22. A pair of metal first opening / closing pieces 32 and a second opening / closing piece 37 are located in the front portion of the front case 22 in pairs. The first opening / closing piece 32 and the second opening / closing piece 37 are substantially bilaterally symmetric, but the entire upper half of the front half of the first opening / closing piece 32 is a recess 33, whereas the second opening / closing piece 37. An upper half of the front half is provided with a blade 38 extending toward the right side (first opening / closing piece 32 side). A pair of upper and lower rotating shafts 34 project from the rear end portion of the first opening / closing piece 32, and a pair of upper and lower rotating shafts parallel to the guide pin 30 and the rotating shaft 34 are disposed at the rear end portion of the second opening / closing piece 37. 39 protrudes. The upper and lower rotary shafts 34 are rotatably fitted in the upper and lower rotary support holes 27 of the tip case 22, and the upper and lower rotary shafts 39 are rotatably fitted in the upper and lower rotary support holes 26 of the tip case 22. Therefore, the first opening / closing piece 32 and the second opening / closing piece 37 are in the fully closed position where the opposing surfaces of the lower half of the front half are in contact with each other and the blade 38 is positioned on the upper surface of the recess 33 (FIGS. 1 and 3). (Position of FIG. 6) and a fully open position (positions of FIG. 2, FIG. 7, FIG. 8) that are separated from each other in the left-right direction. Further, as shown in FIGS. 5 and 7, etc., the rotation shaft 34 on the upper side of the first opening / closing piece 32 and the rotation shaft 39 on the upper side of the second opening / closing piece 37 all have the same number of modules, teeth and dislocation coefficient. Since the gear 35 and the gear 40, which are meshed with each other in a state where an appropriate backlash amount is set, are fixed to each other, the first opening / closing piece 32 and the second opening / closing piece 37 rotate in a plan view. The shaft 34 and the rotating shaft 39 always rotate symmetrically with respect to a reference straight line (not shown) passing through an intermediate position in the front-rear direction. In addition, a cylindrical wire guide (first wire guide) 36 and a wire guide (first wire guide) 41 positioned immediately before the rotation shaft 34 protrude from the lower surfaces of the first opening / closing piece 32 and the second opening / closing piece 37. It is set up.
Further, both ends of an opening / closing wire W3 (for example, metal) are fixed to the left and right side portions of the front surface of the first moving member 18. The opening / closing wire W3 is wound around the wire guide 36 and the rotating shaft 34, and the wire guide 41 and the rotating shaft 39 in the illustrated manner, and the central portion of the opening / closing wire W3 is integrated with the second moving member 29. The wire guide 28 is hung around the rear part. As shown in the figure, the open / close wire W3 is symmetrical with respect to the reference straight line.
Among the configurations described above, the first moving member 18, the second moving member 29, the wire guide 36, the wire guide 41, and the opening / closing wire W3 are components of the power transmission mechanism.

Next, the operation of the open / close forceps 10 will be described.
The open-and-close forceps 10 is used by being inserted into a body cavity from a patient's mouth, for example. At this time, a flexible tube is inserted into the body cavity from the patient's mouth, or an endoscope is inserted. When the tube is inserted, the distal end side of the open / close forceps 10 is inserted into the tube so that the first opening / closing piece 32 and the second opening / closing piece 37 protrude from the distal opening of the tube into the body cavity, and the rear case 11 is inserted into the patient's body. Position it outside the body. On the other hand, when inserting an endoscope, the distal end side of the open / close-type forceps 10 is inserted into the internal conduit of the endoscope from the treatment instrument insertion opening formed in the vicinity of the operation portion of the endoscope, and the endoscope The first opening / closing piece 32 and the second opening / closing piece 37 protrude into the body cavity from the outlet opening of the internal conduit formed on the distal end surface of the insertion portion, and the rear case 11 is located outside the treatment instrument insertion opening (external to the patient). To be located.

For example, when the operation lever 13 is located at the closing operation position shown in FIG. 1 with respect to the rear case 11, the first moving member 18, the second moving member 29, the first opening / closing piece 32, and the second opening / closing piece 37 are at the leading ends. 1 and FIGS. 3 to 6 with respect to the case 22, the first opening / closing piece 32 and the second opening / closing piece 37 are located at the fully closed position.
In this state, when the operator holds the rear case 11 and puts his finger into the finger hooking hole 14 of the operation lever 13 and rotates the operation lever 13 to the open operation position side in FIG. 2, the second pulling is performed as shown in FIG. The wire W2 is pulled backward (base end side). Then, since the second moving member 29 (guide pin 30) slides backward with respect to the tip case 22 (guide long hole 24), the central portion of the opening / closing wire W3 is rotated by the wire guide 28 with the rotation shaft 34 and the rotation shaft 39. Is pulled backwards against. Then, since the force in the T2 direction shown in FIGS. 5 and 7 is applied to the opening / closing wire W3, the first opening / closing piece 32 and the second opening / closing piece 37 rotate away from each other, and the first pulling force of the opening / closing wire W3 The one moving member 18 slides forward with respect to the tip case 22 (guide long hole 24) by the same distance as the second moving member 29 moves backward. When the operation lever 13 reaches the opening operation position in FIG. 2, the first moving member 18 and the second moving member 29 reach the positions shown in FIGS. 7 and 8, and the opening / closing wire W3 is in FIG. Since it becomes the shape shown in FIG. 8, the 1st opening / closing piece 32 and the 2nd opening / closing piece 37 move to the fully open position shown in FIG.7 and FIG.8. When the operation lever 13 is rotated to the fully open position side in this way, the first moving member 18 slides forward, whereby the first pulling wire W1 is pulled forward. As the operation lever 13 rotates, the rotation lever Since 15 rotates from the position of FIG. 1 to the position of FIG. 2, the first puller wire W1 is allowed to move forward (by the operation lever 13 and the rotation lever 15).

  On the other hand, when the operator rotates the operation lever 13 to the closing operation position side in FIG. 1 in this state, the first pulling wire W1 is pulled backward (base end side) as shown in FIG. The moving member 18 slides backward with respect to the tip case 22 (guide long hole 23). Then, since both ends of the opening / closing wire W3 are pulled backward by the first moving member 18, a force in the T1 direction shown in FIGS. 5 and 7 is applied to the opening / closing wire W3. Therefore, the first opening / closing piece 32 and the second opening / closing piece 37 rotate in a direction approaching each other, and the second moving member 29 (wire guide 28) pulled forward by the central portion of the opening / closing wire W3 slides forward. To do. When the operating lever 13 reaches the closing operation position in FIG. 1, the first moving member 18 and the second moving member 29 reach the positions shown in FIGS. 3 to 6, and the opening / closing wire W3 is in FIG. Since it becomes the shape shown in FIG. 6, the 1st opening / closing piece 32 and the 2nd opening / closing piece 37 move to the fully closed position shown in FIGS. If the first opening / closing piece 32 and the second opening / closing piece 37 are rotated to the fully closed position with the affected part in the body cavity positioned between the first opening / closing piece 32 and the second opening / closing piece 37, the second opening / closing piece The affected part or the like is excised between the 37 blade portions 38 and the first opening / closing piece 32. Further, when the operation lever 13 is rotated to the fully closed position in this way, the second pulling wire W2 is pulled forward by the second moving member 29 sliding forward, but as the operation lever 13 rotates, Since the rotation lever 15 rotates from the position of FIG. 2 to the position of FIG. 1 (the operation lever 13 and the rotation lever 15), the second puller wire W2 is allowed to move forward.

  As described above, the open-and-close forceps 10 of the present embodiment has the first pulling wire W1 and the second pulling wire not only when the operation lever 13 is operated to the closing operation position but also to the opening operation position. At the same time one of W2 is pulled backward (base end side), the other is pulled forward (tip end side), and the first pulling wire W1 and the second pulling wire W2 are pressed forward by the rotating lever 15. There is nothing. Therefore, the first pulling wire W1 and the second pulling wire W2 do not buckle when the operation lever 13 is operated, and the force applied to the operation lever 13 is applied to the first opening / closing piece 32 and the second opening / closing piece 37. Since it can be transmitted reliably (no play occurs), the first opening / closing piece 32 and the second opening / closing piece 37 can be reliably opened and closed. Further, the movement amount when the first opening / closing piece 32 and the second opening / closing piece 37 are opened is the same as the movement amount when the first opening / closing piece 37 is closed.

As shown in FIG. 9, instead of providing the operation lever 13 (and the long hole) in the rear case 11, a power-type drive device (operation means) may be provided.
Although not shown in FIG. 9, the rear ends of the first pulling wire W1 and the second pulling wire W2 are fixed to the rotation support shaft 12 provided in the rear case 11 of the open / close forceps 10 ′ of FIG. A rotating lever 15 is rotatably supported, and a motor 45 for rotating the rotating lever 15 in both forward and reverse directions, a controller 46 connected to the motor 45, and a motor 45 are provided in the rear case 11. A power supply (not shown) for supplying electric power is provided, and an operation input means 47 (for example, a button) connected to the control device 46 is provided on the surface of the rear case 11.
Accordingly, if a signal is sent from the control device 46 to the motor 45 by operating the operation input means 47 and the motor 45 is rotated in the forward direction, the turning lever 15 of the open / close type forceps 10 ', the first pulling wire W1, and Since the 2nd pulling wire W2 will be in the same state as FIG. 2, the 1st opening / closing piece 32 and the 2nd opening / closing piece 37 rotate to the full open position side. On the other hand, when the motor 45 is rotated in the reverse direction by operating the operation input means 47, the turning lever 15, the first pulling wire W1, and the second pulling wire W2 of the open / close type forceps 10 ′ are the same as those in FIG. Thus, the first opening / closing piece 32 and the second opening / closing piece 37 rotate to the fully closed position side. While the operation input means 47 is being operated, the motor 45 continues to rotate in the forward direction or the reverse direction. However, when the first opening / closing piece 32 and the second opening / closing piece 37 reach the fully open position or the fully closed position, the motor 45 The supply of power to the motor 45 is automatically shut off. If the operation input means 47 is operated to cut off the supply of power to the motor 45 when the first opening / closing piece 32 and the second opening / closing piece 37 are located between the fully open position and the fully closed position, The piece 32 and the second opening / closing piece 37 are held at this position (position when the operation input means 47 is operated).

Next, a second embodiment of the present invention will be described with reference to FIGS. The same members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof is omitted.
The open-and-close forceps 50 according to the present embodiment also includes a rear case 11 (the embodiment shown in FIGS. 1 and 2 or the embodiment shown in FIG. 9) at the rear end, and the rear case 11 has a rear end of the outer tube 21. The part is fixed. However, in the present embodiment, the vertical positions of the first pulling wire W1 and the second pulling wire W2 are reversed. That is, the first pulling wire W1 is fixed to the upper end portion of the rotating lever 15, and the second pulling wire W2 is fixed to the lower end portion of the rotating lever 15. The front end of the outer tube 21 is fixed to the rear end of a substantially cylindrical tip case 51 made of metal. The tip case 51 is formed with two through-holes that penetrate the tip case 51 in the front-rear direction, and a metal support arm 52 is fixed to the front surface of the tip case 51 as a pair of left and right.
A cylindrical slide member 53 and a slide member 54 made of a hard material such as synthetic resin are respectively placed in a fixed state on the front end portions of the first pull wire W1 and the second pull wire W2, and the slide member 53 and the slide member 54 are respectively fixed. Are respectively slidably inserted into the two through support holes formed in the tip case 51. A support member 55 and a support member 57 having a cross-sectional shape larger than that of the penetrating support hole of the tip case 51 are fixed to the front ends of the slide member 53 and the slide member 54. A recess 56 extending obliquely rearward and upward is provided on the lower surface of the support member 55, and a recess 58 extending obliquely downward and rearward is provided on the upper surface of the support member 57.
The first opening / closing piece 60 and the second opening / closing piece 65 forming a pair are both made of metal, and a blade portion is formed on the inner surface (opposing surface). A connecting piece 61 and a connecting piece 62 are integrally formed on the first opening / closing piece 60, and a connecting piece 66 and a connecting piece 67 are integrally formed on the second opening / closing piece 65. The first opening / closing piece 60 (including the connecting piece 61 and the connecting piece 62) and the second opening / closing piece 65 (including the connecting piece 66 and the connecting piece 67) have the same shape (the second opening / closing piece 65 is the first opening / closing piece). 60 is inverted 180 °). The rear end portions of the first opening / closing piece 60 and the second opening / closing piece 65 are overlapped with each other in the left-right direction, and both end portions of the rotating shaft 63 penetrating the overlapping portion so as to be relatively rotatable in the left-right direction are the left and right support arms. 52 are respectively fixed to the inner surface of the front end portion. Accordingly, the first opening / closing piece 60 and the second opening / closing piece 65 can rotate around the rotation shaft 63 with respect to the left and right support arms 52.

The rear end portions of the first link member 68A and the second link member 68B having the same specifications are positioned in the recessed portion 56 of the support member 55 so as to overlap each other. The first link member 68A and the second link member Both end portions of the rotation support shaft that penetrate the rear end portion of 68B so as to be capable of relative rotation in the left-right direction are respectively fixed to the inner surface (left and right side surfaces) of the recess 56. The front end portion of the first link member 68A is connected to the connection piece 62 so as to be rotatable around a left-right axis, and the front end portion of the second link member 68B is connected to the connection piece 66 so as to be rotatable around a left-right axis. is doing.
On the other hand, the rear end portions of the third link member 69A and the fourth link member 69B, which have the same specifications as the first link member 68A and the second link member 68B, are positioned in the concave portion 58 of the support member 57 in a state where they are overlapped on the left and right. Both end portions of the rotation support shaft that penetrate the rear end portions of the third link member 69A and the fourth link member 69B so as to be relatively rotatable in the left-right direction are respectively fixed to the inner surfaces (left and right side surfaces) of the recess 58. . The front end portion of the third link member 69A is connected to the connection piece 61 so as to be rotatable around a left-right axis, and the front end portion of the fourth link member 69B is connected to the connection piece 67 so as to be rotatable around a left-right axis. is doing.
A linear distance from the connection position of the first link member 68A to the recess 56 to the connection position of the connection piece 62, a linear distance from the connection position of the second link member 68B to the recess 56 to the connection position of the connection piece 66, a third link member The linear distance from the connection position of 69A to the recess 58 to the connection position to the connection piece 61 and the linear distance from the connection position of the fourth link member 69B to the recess 58 to the connection position to the connection piece 67 are all the same.
Among the configurations described above, the first link member 68A, the second link member 68B, the third link member 69A, and the fourth link member 69B are components of the power transmission mechanism.

Next, the operation of the open / close forceps 50 will be described.
For example, when the operation lever 13 is located at the closing operation position (the position shown in FIG. 2 in this embodiment), the first opening / closing piece 60 and the second opening / closing piece 65 are located at the fully closed positions shown in FIGS. .
In this state, when the operator rotates the operation lever 13 to the open operation position (the position of FIG. 1 in this embodiment), the second pulling wire W2 and the slide member 54 are pulled backward (base end side). The third link member 69A and the fourth link member 69B supported by the support member 57 move rearward. Then, since the connection piece 61 connected to the third link member 69A is pulled rearward, the first opening / closing piece 60 rotates around the rotation shaft 63 in the clockwise direction in FIGS. 10 to 13 and the fourth link member 69B. Since the connected connecting piece 67 is pulled rearward, the second opening / closing piece 65 rotates around the rotation shaft 63 in the counterclockwise direction of FIGS. When the operation lever 13 reaches the opening operation position of FIG. 1, the third link member 69A and the fourth link member 69B reach the positions shown in FIGS. The two open / close pieces 65 are moved to the fully open positions shown in FIGS. When the first opening / closing piece 60 and the second opening / closing piece 65 move to the fully open position in this way, the connection of the first link member 68A connected to the connection piece 62 of the first opening / closing piece 60 and the second opening / closing piece 65 is achieved. Since the second link member 68B connected to the piece 66 is pulled forward, the support member 55 connected to the rear end portion of the first link member 68A and the second link member 68B is pulled forward, and further One pulling wire W1 is pulled forward. However, since the rotation lever 15 rotates from the position of FIG. 2 to the position of FIG. 1 as the operation lever 13 rotates, the first puller wire W1 moves forward (by the operation lever 13 and the rotation lever 15). Is acceptable.

On the other hand, when the surgeon rotates the operation lever 13 to the closing operation position side in FIG. 2 in this state, the first pulling wire W1 and the slide member 53 are pulled backward (base end side). The supported first link member 68A and second link member 68B move rearward. Then, since the connecting piece 62 connected to the first link member 68A is pulled rearward, the first opening / closing piece 60 rotates around the rotation shaft 63 in the counterclockwise direction of FIGS. 10 to 13 and the second link member 68B. Since the connecting piece 66 connected to is pulled backward, the second opening / closing piece 65 rotates around the rotation shaft 63 in the clockwise direction of FIGS. Then, when the operation lever 13 reaches the closing operation position in FIG. 2, the first link member 68A and the second link member 68B reach the positions shown in FIGS. The two opening / closing pieces 65 move to the fully closed position shown in FIGS. Thus, when the first opening / closing piece 60 and the second opening / closing piece 65 move to the fully closed position, the third link member 69A connected to the connection piece 61 of the first opening / closing piece 60 and the second opening / closing piece 65 Since the fourth link member 69B connected to the connection piece 67 is pulled forward, the third link member 69A and the support member 57 connected to the rear end portion of the fourth link member 69B are pulled forward, and further The second puller wire W2 is pulled forward. However, the rotation lever 15 rotates from the position of FIG. 1 to the position of FIG. 2 as the operation lever 13 rotates, so that the second puller wire W2 moves forward (by the operation lever 13 and the rotation lever 15). Is acceptable.
Since the first link member 68A and the second link member 68B always rotate vertically symmetrically, and the third link member 69A and the fourth link member 69B always rotate vertically symmetrically, the first opening / closing piece 60 and the first link member The two opening / closing pieces 65 rotate symmetrically in the vertical direction when rotating in either the opening direction or the closing direction.

  As described above, the opening / closing type forceps 50 of the present embodiment also includes the first pulling wire W1 and the second pulling wire not only when the operation lever 13 is operated to the closing operation position but also to the opening operation position. One side of W2 is pulled backward (base end side) and at the same time the other side is pulled forward (tip end side), and the first pulling wire W1 and the second pulling wire W2 are not pushed forward. Therefore, the same effect as the first embodiment can be obtained.

Subsequently, a third embodiment of the present invention will be described with reference to FIGS. It should be noted that the same members as those of the previous embodiment are designated by the same reference numerals, and detailed description thereof is omitted.
The open-and-close forceps 70 of this embodiment also includes a rear case 11 at the rear end, and the rear end of the outer tube 21 is fixed to the rear case 11. The vertical positions of the first pulling wire W1 and the second pulling wire W2 in this embodiment are the same as those in the second embodiment, and the first pulling wire W1 is fixed to the upper end portion of the rotating lever 15, and the second The pulling wire W <b> 2 is fixed to the lower end portion of the rotation lever 15. The front end portion of the outer tube 21 is fixed to the rear end portion of a substantially cylindrical tip case 71 made of metal. Slits 72 are formed in the upper and lower portions of the tip case 71, and a pair of left and right rotation support holes 73, 74, 75 are formed in the tip case 71.
Both ends of a rotation shaft 76 extending in the left-right direction are rotatably fitted in the left and right rotation support holes 73 of the tip case 71, and a pulley 77 and a metal gear (first rotation gear) are fitted to the rotation shaft 76. 78 is fixed by overlapping on the left and right. The front ends of the first pulling wire W1 and the second pulling wire W2 are fixed to each other and are wound around the pulley 77. Further, in the present embodiment, the cover coils 79 are placed around the first pulling wire W1 and the second pulling wire W2 so as to be relatively movable.
The rear end portions of the first opening / closing piece 32 and the second opening / closing piece 37 are positioned inside the tip case 71, and a pair of left and right rotations fixed to the rear end portions of the first opening / closing piece 32 and the second opening / closing piece 37, respectively. A shaft 80 and a rotating shaft 81 are rotatably fitted in the left and right rotation support holes 74 and the rotation support holes 75, respectively. Furthermore, a gear (second rotating gear) 82 and a gear (third rotating gear) 83, both of which are made of metal, are provided at the rear end portion of the right surface of the first opening / closing piece 32 and the rear end portion of the second opening / closing piece 37, respectively. It is formed integrally. As shown, the gear 82 is thicker than the gear 78, and the right half of the gear 82 is engaged with the gear 78. The gear 83 is thinner than the gear 82 and meshes with the left half of the gear 82. Further, since the left and right positions of the gear 78 and the gear 83 are shifted from each other, the gear 78 and the gear 83 are not engaged with each other. Although the thicknesses of the gear 82 and the gear 83 are different from each other, the module, the number of teeth, and the dislocation coefficient in the cross-sectional shape (side surface shape) of both are the same, and an appropriate backlash amount is set.
Among the configurations described above, the pulley 77, the gear 78, the gear 82, and the gear 83 are components of the power transmission mechanism.

Next, the operation of the open / close type forceps 70 will be described.
For example, when the operation lever 13 is located at the closing operation position in FIG. 2, the first opening / closing piece 32 and the second opening / closing piece 37 are located at the fully closed positions shown in FIGS. 16, 18, 20, and 22.
In this state, when the operator rotates the operation lever 13 to the open operation position side in FIG. 1, the second pulling wire W2 is pulled backward and the first pulling wire W1 is pulled forward. 78 rotates counterclockwise in FIGS. 20 and 21 around the rotation shaft 76. Then, the gear 82 rotates clockwise in FIGS. 20 and 21, and the gear 83 rotates counterclockwise in FIGS. 20 and 21, so that the first opening / closing piece 32 and the second opening / closing piece 37 are separated from each other. Rotate in the direction. When the operation lever 13 reaches the opening operation position in FIG. 1, the first opening / closing piece 32 and the second opening / closing piece 37 move to the fully open position shown in FIGS. Thus, when the operating lever 13 is rotated to the fully open position side, the first pulling wire W1 is pulled forward, but as the operating lever 13 rotates, the rotating lever 15 rotates from the position of FIG. 2 to the position of FIG. Therefore, the forward movement of the first pulling wire W1 is allowed (by the operation lever 13 and the rotation lever 15).

On the other hand, when the operator rotates the operation lever 13 to the closing operation position side in FIG. 2 in this state, the first pulling wire W1 is pulled backward (base end side) and the second pulling wire W2 is forward (distal tip). 21), the pulley 77 and the gear 78 rotate in the clockwise direction in FIG. 20 and FIG. Then, the gear 82 rotates counterclockwise in FIGS. 20 and 21, and the gear 83 rotates clockwise in FIGS. 20 and 21, so that the first opening / closing piece 32 and the second opening / closing piece 37 approach each other. Rotate in the direction. When the operation lever 13 reaches the closing operation position in FIG. 2, the first opening / closing piece 32 and the second opening / closing piece 37 move to the fully closed positions shown in FIGS. 16, 18, 20, and 22. Thus, when the operation lever 13 is rotated to the fully closed position side, the second pulling wire W2 is pulled forward, but the rotation lever 15 is moved from the position of FIG. 1 to the position of FIG. Since it rotates, the forward movement of the second pulling wire W2 is allowed (by the operation lever 13 and the turning lever 15).
Since the gear 82 and the gear 83 have the same module, the same number of teeth, and a shift coefficient, and an appropriate backlash amount is set, the first opening / closing piece 32 and the second opening / closing piece 37 are opened and closed. When rotating in any direction, it rotates vertically.

As described above, the opening / closing type forceps 70 of the present embodiment also includes the first pulling wire W1 and the second pulling wire not only when the operation lever 13 is operated to the closed operation position but also to the open operation position. One side of W2 is pulled backward (base end side) and at the same time the other side is pulled forward (tip end side), and the first pulling wire W1 and the second pulling wire W2 are not pushed forward. Therefore, the same effect as the first embodiment can be obtained.
Furthermore, since the power transmission mechanism is simple compared to the first and second embodiments, it can be manufactured at low cost.

Finally, a fourth embodiment of the present invention will be described with reference to FIGS. It should be noted that the same members as those of the previous embodiment are designated by the same reference numerals, and detailed description thereof is omitted.
The open-and-close forceps 90 of this embodiment also includes a rear case 11 at the rear end, and the rear end of the outer tube 21 is fixed to the rear case 11. The vertical positions of the first pulling wire W1 and the second pulling wire W2 in this embodiment are the same as those in the second embodiment, and the first pulling wire W1 is fixed to the upper end portion of the rotating lever 15, and the second The pulling wire W <b> 2 is fixed to the lower end portion of the rotation lever 15. The front end portion of the outer tube 21 is fixed to the rear end portion of a substantially cylindrical tip case 91 made of metal. A slit 92 is formed above and below the front half of the tip case 91, and a pair of left and right rotation support holes 73, 93, 94, 95, and 96 are formed in the tip case 91.
The left and right ends of the rotation shaft 76 are rotatably fitted in the left and right rotation support holes 73 of the tip case 91. The left and right rotation support holes 93 are rotatably fitted with left and right ends of a rotation shaft 98 that is integrated with a metal gear (third rotation gear) 99 and extends in the left-right direction. The left and right end portions of the rotating shaft 100 extending in the left-right direction integrated with the metal gear (second rotating gear) 101 are rotatably fitted in the hole 94. As illustrated, the gear 101 is thicker than the gear 78, and the right half of the gear 101 is engaged with the gear 78. The gear 99 is thinner than the gear 101 and meshes with the left half of the gear 101. Further, since the left and right positions of the gear 78 and the gear 99 are shifted from each other, the gear 78 and the gear 99 are not engaged with each other. Although the thicknesses of the gear 99 and the gear 101 are different from each other, the modules, the number of teeth, and the dislocation coefficient in the cross-sectional shape (side shape) of the both are the same, and an appropriate backlash amount is set.
The left and right rotation support holes 95 of the tip case 91 are rotatably fitted to the left and right ends of the rotary shaft 80 provided in the first opening / closing piece 32, and the left and right rotation support holes 96 are fitted to the second opening / closing piece 37. The left and right ends of the rotation shaft 81 provided on the shaft are fitted rotatably. Further, a metal gear (fifth rotating gear) 103 that meshes with the gear 99 is integrally formed at the rear end portion of the left side surface of the first opening / closing piece 32, and the left side surface of the second opening / closing piece 37 is formed. A metal gear (fourth rotation gear) 104 that meshes with the gear 101 is integrally formed at the rear end portion. As shown in the figure, the gear 103 and the gear 104 have different numbers of teeth, but the modules, the number of teeth, and the dislocation coefficient are the same in both cross-sectional shapes (side shapes), and an appropriate backlash amount is set.
Among the configurations described above, the pulley 77, the gear 78, the gear 99, the gear 101, the gear 103, and the gear 104 are components of the power transmission mechanism.

Next, the operation of the open / close type forceps 90 will be described.
For example, when the operation lever 13 is located at the closing operation position in FIG. 2, the first opening / closing piece 32 and the second opening / closing piece 37 are located at the fully closed positions shown in FIGS. 23, 25, 27, and 29.
In this state, when the operator rotates the operation lever 13 toward the opening operation position in FIG. 1, in the present embodiment, the second pulling wire W2 is pulled backward (base end side) and the first pulling wire W1 is moved forward. Since the pulley 77 and the gear 78 are pulled by the (front end side), the pulley 77 and the gear 78 rotate counterclockwise in FIGS. Then, the gear 101 rotates clockwise in FIGS. 27 and 28, and the gear 99 rotates counterclockwise in FIGS. Accordingly, the gear 104 engaged with the gear 101 rotates counterclockwise, and the gear 103 engaged with the gear 99 rotates clockwise, so that the first opening / closing piece 32 and the second opening / closing piece 37 are Rotate away from each other. When the operation lever 13 reaches the opening operation position, the first opening / closing piece 32 and the second opening / closing piece 37 move to the fully opened position shown in FIGS. Thus, when the operating lever 13 is rotated to the fully open position side, the first pulling wire W1 is pulled forward, but as the operating lever 13 rotates, the rotating lever 15 rotates from the position of FIG. 2 to the position of FIG. Therefore, the forward movement of the first pulling wire W1 is allowed (by the operation lever 13 and the rotation lever 15).

On the other hand, when the operator rotates the operation lever 13 to the closing operation position side in FIG. 2 in this state, the first pulling wire W1 is pulled backward (base end side) and the second pulling wire W2 is forward (distal tip). The pulley 77 and the gear 78 are rotated in the clockwise direction in FIGS. 27 and 28 about the rotation shaft 76. Then, the gear 101 rotates counterclockwise in FIGS. 27 and 28, and the gear 99 rotates clockwise in FIGS. Therefore, the gear 104 meshing with the gear 101 rotates clockwise, and the gear 103 meshing with the gear 99 rotates counterclockwise, so that the first opening / closing piece 32 and the second opening / closing piece 37 are Rotate in a direction approaching each other. When the operation lever 13 reaches the closing operation position in FIG. 2, the first opening / closing piece 32 and the second opening / closing piece 37 move to the fully closed positions shown in FIGS. 23, 25, 27, and 29. Thus, when the operation lever 13 is rotated to the fully closed position side, the second pulling wire W2 is pulled forward, but the rotation lever 15 is moved from the position of FIG. 1 to the position of FIG. Since it rotates, the forward movement of the second pulling wire W2 is allowed (by the operation lever 13 and the turning lever 15).
The gear 99 and the gear 101 have the same module, the number of teeth, and the shift coefficient, and an appropriate backlash amount is set, and the gear 103, the gear 104 have the same module, the number of teeth, and the shift coefficient. Since an appropriate backlash amount is set, the first opening / closing piece 32 and the second opening / closing piece 37 rotate symmetrically in the vertical direction when rotating in either the opening direction or the closing direction.

As described above, the open-and-close forceps 90 of the present embodiment also has the first pulling wire W1 and the second pulling wire not only when the operation lever 13 is operated to the closed operation position but also to the open operation position. One side of W2 is pulled backward (base end side) and at the same time the other side is pulled forward (tip end side), and the first pulling wire W1 and the second pulling wire W2 are not pushed forward. Therefore, the same effect as the first embodiment can be obtained.
Further, since the gear 99 and the gear 101 are interposed between the gear 103, the gear 104, and the gear 78, the first opening / closing piece 32 and the second opening / closing piece 37 are adjusted by adjusting the number of teeth of the gear 99 and the gear 101. Can be adjusted with high accuracy. If the reduction ratio is adjusted by increasing the number of gears arranged between the gear 78 and the gears 103, 104, the traction stroke amount of the first traction wire W1 and the second traction wire W2 can be adjusted, The force transmitted to the opening / closing piece 32 and the second opening / closing piece 37 can be adjusted.

As mentioned above, although this invention was demonstrated based on the said embodiment, this invention can be implemented, giving various changes.
For example, instead of the first opening / closing piece 32, the second opening / closing piece 37, the first opening / closing piece 60, and the second opening / closing piece 65, a first opening / closing piece and a second opening / closing piece not provided with a blade portion may be provided. . With such a structure, the affected part in the body cavity can be grasped without being cut by closing the first opening / closing piece and the second opening / closing piece.

10 10 'Open / close forceps 11 Rear case 12 Rotating support shaft 13 Operation lever (operation means)
14 Finger hole 15 Rotating lever (operating means)
18 First moving member (power transmission mechanism)
19 guide support hole 20 guide pin 21 outer tube 22 tip case 23 24 guide long hole 25 slit 26 27 rotation support hole 28 wire guide (second wire guide)
29 Second moving member (power transmission mechanism)
30 Guide pin 32 First opening / closing piece 33 Recess 34 Rotating shaft 35 Gear 36 Wire guide (first wire guide) (power transmission mechanism)
37 2nd opening-and-closing piece 38 Blade part 39 Rotating shaft 40 Gear 41 Wire guide (1st wire guide) (Power transmission mechanism)
45 Motor (actuator)
46 control device 47 operation input means 50 open / close forceps 51 tip case 52 support arm 53 54 slide member 55 support member 56 recess 57 support member 58 recess 60 first opening / closing piece 61 62 connecting piece 63 rotating shaft 65 second opening / closing piece 66 67 Connection piece 68A First link member (power transmission mechanism)
68B Second link member (power transmission mechanism)
69A Third link member (power transmission mechanism)
69B Fourth link member (power transmission mechanism)
70 Opening / Closing Forceps 71 Tip Case 72 Slit 73 74 75 Rotation Support Hole 76 Rotation Shaft 77 Pulley (Power Transmission Mechanism)
78 Gear (first rotating gear) (Power transmission mechanism)
79 Cover coil 80 81 Rotating shaft 82 Gear (second rotating gear) (Power transmission mechanism)
83 Gear (3rd rotating gear) (Power transmission mechanism)
90 Opening / Closing Forceps 91 Tip Case 92 Slit 93 94 95 96 Rotation Support Hole 98 Rotation Shaft 99 Gear (Third Rotation Gear) (Power Transmission Mechanism)
100 Rotating shaft 101 Gear (second rotating gear) (Power transmission mechanism)
103 Gear (5th rotating gear) (Power transmission mechanism)
104 Gear (4th rotating gear) (Power transmission mechanism)
W1 First pulling wire W2 Second pulling wire W3 Opening / closing wire (power transmission mechanism)

Claims (8)

A pair of opening and closing pieces provided at the tip;
A first puller wire and a second puller wire;
Operating means for allowing one of the first pulling wire and the second pulling wire to be pulled toward the proximal end and allowing the other to be pulled toward the distal end;
The first pulling wire and the second pulling wire are connected to the distal ends of the first pulling wire and the pair of opening / closing pieces. When the first pulling wire is pulled to the proximal end side, the second pulling wire is pulled to the distal end side. A power transmission mechanism that moves both opening and closing pieces in the closing direction and pulls the first pulling wire to the distal end side and moves both opening and closing pieces in the opening direction when the second pulling wire is pulled to the proximal end side When,
A medical open / close forceps characterized by comprising: The medical open / close forceps according to claim 1,
The power transmission mechanism is
A first wire guide formed on each of the pair of opening and closing pieces;
A first moving member, which is positioned between the opening / closing piece and the operating means, the tip of the first pulling wire being fixed, and movable in a direction approaching the opening / closing piece and a direction approaching the operating means;
A second moving member having a second wire guide, the tip of the second pulling wire being fixed, positioned between the opening / closing piece and the operating means, movable in a direction approaching the opening / closing piece and a direction approaching the operating means; ,
Both ends are fixed to the first moving member, a central portion is hung around the second wire guide of the second moving member, and a gap between the central portion and both ends is connected to the first wire guide of a pair of opening and closing pieces. Each open and close wire for opening and closing,
A medical open / close forceps comprising: The medical open / close forceps according to claim 2,
A medical open / close type forceps in which gears of the same module and the same number of teeth are formed on opposite portions of the pair of open / close pieces. The medical open / close forceps according to claim 1,
The power transmission mechanism is
A first link member that rotates coaxially with respect to the distal end of the first puller wire, and that is rotatably connected to one open / close piece; and a second link member that is rotatably connected to the other open / close piece;
A third link member that rotates coaxially with the tip of the second puller wire and that is rotatably connected to the one open / close piece, and a fourth link member that is rotatably connected to the other open / close piece When,
A medical open / close forceps comprising: The medical open / close forceps according to claim 1,
Combining the first puller wire and the second puller wire;
The power transmission mechanism is
A rotatable pulley around which a combined body of the first pulling wire and the second pulling wire is wound;
A first rotating gear that rotates with the pulley;
A second rotation gear fixed to one of the opening and closing pieces and meshing with the first rotation gear;
A third rotating gear fixed to the other opening / closing piece and meshing with the second rotating gear;
Medical open / close forceps comprising medical open / close forceps. The medical open / close forceps according to claim 5,
A medical open / close forceps in which the second rotation gear and the third rotation gear have the same module and the same number of teeth. The medical open / close forceps according to claim 1,
Combining the first puller wire and the second puller wire;
The power transmission mechanism is
A rotatable pulley around which a combined body of the first pulling wire and the second pulling wire is wound;
A first rotating gear that rotates with the pulley;
A second rotating gear meshing with the first rotating gear;
A third rotating gear meshing with the second rotating gear;
A fourth rotating gear fixed to one of the opening and closing pieces and meshing with the second rotating gear;
A fifth rotating gear fixed to the other opening / closing piece and meshing with the third rotating gear;
Medical open / close forceps comprising medical open / close forceps. The medical open / close forceps according to claim 7,
A medical open / close forceps in which the second rotation gear and the third rotation gear have the same module and the same number of teeth, and the fourth rotation gear and the fifth rotation gear have the same module and the same number of teeth.

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