JP3929009B2 - Forceps with ratchet mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a forceps with a ratchet mechanism, and more particularly to a structure of a forceps that is suitably used for endoscopic surgery.
[0002]
[Prior art]
In recent years, in surgery for treating diseases such as the chest and abdomen, endoscopic surgery has been performed for the reason that the risk of infection is less than incision surgery and the wound healing period is shortened. Increasing cases are taking place.
[0003]
In endoscopic surgery, a small hole is drilled on the patient's body surface with a trocar, a cannula tube is inserted into the body cavity, and an endoscope is inserted into the body cavity through this cannula tube while another surgical cannula is observed. Endoscopic surgical forceps, clips, automatic suturing devices and the like are inserted into the body cavity from the tube, and operations such as excision of the affected part and sutures are performed.
[0004]
FIG. 4 is a perspective view showing an example of a forceps conventionally used in such an endoscopic operation, and this type of forceps A1 is a pair of openable and closable for grasping a body tissue such as a viscera or a blood vessel at the tip. The elongated shaft portion A3 having the finger A2 and the handle portion A4 to be held and held by the hand.
[0005]
The handle portion A4 is formed with a finger ring A5 for inserting and holding a finger when the surgeon performs an operation, and an operation lever A6 is hidden behind the handle portion A4. It is attached so as to be rotatable around the support shaft.
[0006]
The opening / closing operation of the operation lever A6 around the support shaft with respect to the finger ring A5 is configured to be interlocked with the opening / closing operation of the pair of fingers A2 at the tip of the shaft portion A3, and the direction in which the operation lever A6 approaches the finger ring A5. The pair of fingers A2 are closed so as to grasp the body tissue.
[0007]
Further, by turning the rotary knob A7 provided on the upper part on the front end side of the handle portion A4 with a finger, the orientation of the pair of fingers A2 can be rotated around the central axis of the shaft portion A3 together with the shaft portion A3. It is like that.
[0008]
A ratchet mechanism A8 is incorporated between the operation lever A6 and the finger ring A5 of the handle portion A4 to restrain the movement in the direction of opening the pair of fingers A2, and the operation lever A6 is operated by the ratchet mechanism A8. Even if the hand is released from the operation lever A6 in a state where the tissue is gripped by the pair of fingers A2 by operating the above, the state where the pair of fingers A2 grips the tissue is maintained.
[0009]
The ratchet mechanism A8 includes a ratchet bar A9 that protrudes toward the finger ring A5 along the circumferential direction around the rotation center from the operation lever A6, and one end of the ratchet mechanism A8 is fixedly supported in a cantilevered state on the finger ring A5 side. The plate spring-shaped ratchet A10 that can be elastically deformed and deformed and a ratchet release lever A11.
[0010]
A claw t is provided on the free end side of the ratchet A10 so as to be opposed to the sawtooth ratchet teeth T formed on the ratchet bar A9. As shown in FIG. 5A, the ratchet release lever A11 is provided. Is tilted to the operation lever A6 side about the support shaft A12, the ratchet A10 is lifted upward by the cam surface c formed on the ratchet release lever 11, and the claw t is raised by the ratchet teeth T of the ratchet bar A9. It is pressed against.
[0011]
In this state, when the operation lever A6 is rotated in the direction in which the pair of fingers A2 shown in FIG. 4 is closed, the ratchet A10 is elastically bent so that the claws t get over the ratchet teeth T one after another and move to the operation lever A6 at a desired position. When the applied force is loosened, the claw t is engaged with one of the ratchet teeth T by the elastic restoring force of the ratchet A10 having spring characteristics, and the reverse of the operation lever A6 from that position is prevented.
[0012]
Next, when opening the pair of fingers A2, as shown in FIG. 5B, the ratchet release lever A11 is tilted about the support shaft A12 to the side opposite to the operation lever A6 side.
[0013]
Then, since the cam surface c formed on the operation lever A6 is separated from the lower surface of the ratchet A10, the claw t is separated from the tooth surface T of the ratchet bar A9 by the elastic restoring force of the ratchet A10, and the operation lever A6 is a pair of fingers. A rotation operation in the direction of opening A2 is possible.
[0014]
[Problems to be solved by the invention]
In the conventional forceps with a ratchet mechanism having the above-described configuration, the operation of releasing the ratchet pawl from the ratchet teeth is performed using the elastic restoring force of the ratchet formed in a leaf spring shape.
[0015]
On the other hand, since the reaction force in the direction of opening from the tissue side always acts on the pair of fingers in the state of grasping the body tissue, the saw-toothed ratchet teeth and the ratchet pawls are firmly engaged with each other. .
[0016]
As a result, if the ratchet pawl is not easily separated from the ratchet teeth by simply operating the release lever to release the ratchet mechanism, the ratchet springs are weak, or the pair of fingers firmly holds the tissue Then, there is a problem that the ratchet pawls cannot be removed from the ratchet teeth unless the operating lever is rotated once in the direction in which the fingers are closed.
[0017]
In particular, the pair of fingers inserted into the patient's body and grasping the body tissue cannot be seen directly by the surgeon operating the forceps, so the release lever was operated to release the fingers. When the forceps are pulled out from the patient's body, the pair of fingers still hold the body tissue, and the body tissue may be dragged and serious damage may occur.
[0018]
Accordingly, an object of the present invention is to provide a forceps with a ratchet mechanism that is capable of solving the problems in the prior art as described above and reliably releasing the ratchet mechanism and having excellent operability. .
[0019]
[Means for Solving the Problems]
In order to achieve the above object, the forceps with a ratchet mechanism according to the present invention has an elongated shaft portion having a pair of openable / closable fingers attached to a front end for gripping body tissue, and a lower portion connected to the rear end of the shaft portion. A pair of fingers that open and close in conjunction with a turning operation of an operation lever pivotally supported by the handle portion. In the forceps with a ratchet mechanism provided with a ratchet mechanism structured to prevent movement of the pair of fingers in the opening direction, the ratchet mechanism is pivotally supported by a shaft in a handle portion , and at least from the shaft to the shaft a cam follower projecting toward the part, a ratchet and a lever portion provided protrudes pawl toward the operating lever side from the shaft, provided on the operating lever And ratchet teeth formed on the serrated for engagement with projecting the pawl toward the lever portion of the ratchet, and exposed to the outside at a position close to the shaft portion at the front end of the handle portion can be operated by a finger A ratchet release switch that includes an operation portion and a cam portion that extends rearward from the operation portion and protrudes toward the cam follower portion of the ratchet, and that is in sliding contact with the cam follower portion, and the ratchet release switch includes: a first position for maintaining the engagement between the ratchet teeth and the pawl not interfere with the ratchet rotating, force the pawl from the ratchet teeth wherein the cam portion presses the cam follower portion of the ratchet the second is held in the handle part freely displaceable between a position, the first position and the hand and the operating unit in both positions of the second position to be spaced Characterized in that it has an insertable spacing the fingers between the parts.
[0020]
In the forceps with a ratchet mechanism of the present invention, the ratchet release switch is elastically engaged and held with the handle portion at each of the first position and the second position, and the operation portion is operated. Engagement holding means capable of forcibly releasing the engagement state is provided, and the engagement holding means is provided on the handle portion side engagement portion provided on the handle portion and on the ratchet release switch side. It is preferable that a ratchet release switch side engagement portion that engages with the handle portion side engagement portion at the first position and the second position is provided.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
The forceps with a ratchet mechanism of the present invention can be used in the same manner as a conventional forceps of this type, and a surgeon who uses the forceps can use a cannula tube inserted in a hole previously opened in the chest or abdomen of a patient by a trocar. The shaft is inserted into the patient's body cavity and used.
[0023]
When inserting the forceps shaft into the cannula tube, the pair of fingers are closed once, and the surgeon is in a position where these fingers protrude from the tip of the cannula tube in the patient's body and reach the body tissue to be grasped. Rotates the operating lever to open the fingers.
[0024]
Next, the ratchet release switch is switched to a position (first position) that does not hinder the rotation of the ratchet, and then the operation lever is operated to close the pair of fingers and grasp the body tissue.
[0025]
In this operation, the ratchet pawl moves over the saw-toothed ratchet teeth provided on the operation lever, and the ratchet spring that urges the ratchet at the position where the hand of the operation lever is released releases the ratchet. Engaging with one of the teeth, the pair of fingers are held securely gripping the body tissue.
[0026]
Next, when the pair of fingers are opened to release the grasped tissue and the forceps are pulled out of the patient's body, the surgeon first switches the ratchet release switch to the release position (second position).
[0027]
Then, the cam part provided in the ratchet release switch pushes the cam follower part of the ratchet, rotates the ratchet around its support shaft against the urging force of the ratchet spring, and forcibly removes the pawl from the ratchet teeth. Let
[0028]
As a result, the operating lever can freely rotate, and the gripping force of the fingers that have gripped the body tissue is lost. Here, once the surgeon opens the finger to release the body tissue and then closes the finger again, the shaft portion of the forceps can be pulled out of the patient's body through the cannula tube.
[0029]
The ratchet release switch may be provided so as to be linearly slidable with respect to the handle portion, or may be provided so as to be able to be rotationally displaced about one support shaft.
[0030]
In any case, the cam portion provided in the ratchet release switch does not interfere with the cam follower portion of the ratchet, the first position where the ratchet can be freely rotated, and the cam portion hits the cam follower portion, The ratchet release switch may be configured to be displaceable between the second position where the ratchet pawl is held away from the ratchet teeth.
[0031]
The ratchet release switch is elastically engaged and held at each of the first position and the second position. When the ratchet release switch is displaced from one position to the other position, press the operation unit with a finger. It is desirable to provide an engagement holding means capable of forcibly releasing the engagement state at each position.
[0032]
As the engagement holding means, for example, an engagement portion formed integrally with a ratchet release switch and a locking piece that can be elastically deformed and deformed in a direction perpendicular to the displacement direction, and protrudes to the free end side of the locking piece. When the ratchet release switch is displaced from one position to the other position so that it can be engaged with the engaging portion formed on the handle portion side on both the first position side and the second position side, It can be configured such that the piece is bent and the engaging part on the locking piece side slides and passes over the engaging part on the handle part side.
[0033]
In addition, an engagement portion is formed by simply projecting the engagement portion on the ratchet release switch side, and an engagement holding means is formed by providing an elastically deformable engagement piece similar to the engagement piece on the handle portion side. Also good.
[0034]
Furthermore, a shallow concave portion in which the other falls on either one of the contact surfaces of the cam portion of the ratchet release switch or the cam follower portion of the ratchet may be provided so as to have the function of the engagement holding means.
[0035]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a forceps with a ratchet mechanism used in endoscopic surgery, showing an embodiment of the present invention. The forceps with a ratchet mechanism (hereinafter simply referred to as forceps) 1 has a finger ring 2A. A handle portion 2 made of resin and an elongated shaft portion 3 made of metal projecting forward from the front end of the handle portion 2 are provided.
[0036]
At the front end of the shaft portion 3 is attached a finger support portion 5 on which a pair of fingers 4 are pivotally mounted so as to be openable and closable, and the pair of fingers 4 rotate behind the finger ring 2A of the bundle portion 2. The operation lever 6 that is freely pivoted is opened by rotating backward (a direction in the figure) and closed by rotating forward (b direction in the figure).
[0037]
A ratchet release switch 7, which will be described later, is provided below the lower end of the front end of the handle portion 2 so as to be slidable in the front-rear direction with respect to the handle portion 2. A finger rotation knob 8 is attached above the ratchet release switch 7 of the handle portion 2.
[0038]
The finger rotation knob 8 is rotated by hand, so that the shaft portion 3 and the finger support portion 5 rotate integrally around the central axis of the shaft portion 3 to rotate the direction of the pair of fingers 4. The body tissue can be grasped in various directions.
[0039]
A terminal 9 is provided on the top of the handle portion 2 so as to protrude rearward. The terminals 9 are electrically connected to the pair of fingers 4. When an electric power is supplied to the terminals 9 from an external power source (not shown), an electric current is passed through the body tissue gripped by the fingers 4 to perform treatment such as hemostasis. It can be done.
[0040]
Next, FIG. 2 is a perspective view showing a state in which the handle portion 2 of the forceps 1 is disassembled. The handle portion 2 is obtained by aligning the right side portion 2B including most of the finger ring 2A and the remaining left side portion 2C from the left and right. These two portions 2B and 2C are formed by press-fitting small diameter portions at both ends of the dowel pins 12 and 13 into dowel holes 10 and 11 formed at two opposing positions on the inside. It can be assembled together.
[0041]
Fine serrations are formed on the outer peripheral surfaces of the small-diameter portions near both ends of the dowel pins 12 and 13 so that the dowel pins 12 and 13 are firmly engaged with the inner peripheral surfaces of the dowel holes 10 and 11. The two parts 2B and 2C constituting the two are firmly coupled so as not to be separated in a normal use state.
[0042]
The operating lever 6 has a shaft 14 that is inserted into the shaft hole 6 </ b> A and protrudes inside the right portion 2 </ b> B of the handle portion 2, and is supported rotatably around the shaft 14. It has a circular notch 6B that rotatably holds a connecting pivot 16 attached to the rear end of the finger opening / closing rod 15 that slidably passes through.
[0043]
The finger open / close rod 15 is linked to the pair of fingers 4 on the front end side, and has a role of transmitting the rotation operation around the shaft 14 of the operation lever 6 to these fingers 4 to open and close the finger. The vicinity of the rear end is electrically connected to the terminal 9 through the conductive plate 17 and has a role as a conducting conductor from the terminal 9 to the pair of fingers 4.
[0044]
On the other hand, the operation lever 6 is integrally formed with a ratchet bar 6C having ratchet teeth T arranged in a sawtooth shape on a circumference concentric with the shaft hole 6A.
The ratchet bar 6 </ b> C is accommodated in the handle portion 2, and is arranged so that the ratchet teeth T face the claw t of the ratchet 18.
[0045]
The ratchet 18 is rotatably supported by a shaft 19 protruding in parallel with the shaft 14 inside the right portion 2B of the handle portion 2, and has a lever portion 18A having the claw t at the tip portion, a spring receiving portion. 18B and the cam follower portion 18C have a shape projecting radially in three directions around the shaft 19.
[0046]
A ratchet spring 20 made of a compression coil spring is elastically mounted between the spring receiving portion 18B and the handle portion 2, and the ratchet spring 20 is rotated clockwise around the shaft 19 in FIG. A moment is applied to urge the claw t so that it always engages the ratchet teeth T.
[0047]
Further, the cam follower portion 1 8 C top surface of the ratchet 18 is disposed opposite to the cam portion 7A formed in the ratchet release switch 7. The ratchet release switch 7 is provided on both sides of an operation portion 7B exposed from the handle portion 2 for operation with a finger and guide grooves G formed on the inner sides of the left and right portions 2B and 2C of the handle portion 2 so as to face each other. Has a guide portion 7C that is slidably engaged.
[0048]
3A shows an engaged state between the pawl t of the ratchet 18 and the ratchet teeth T. In this state, the ratchet release switch 7 is in the retracted position, and the cam portion 7A is the cam follower portion of the ratchet 18. It is located behind 18C.
[0049]
In this state, the ratchet 18 receives a clockwise moment around the shaft 19 from the ratchet spring 20, the claw t is constantly pressed against the ratchet teeth T, and the operating lever 6 is in the direction of the arrow a. Although rotation is possible, rotation in the direction of the arrow b is prevented.
[0050]
With this structure, when the surgeon grasps the finger ring 2A of the handle portion 2 and operates the operation lever 6 in the direction a and grips the body tissue with the pair of fingers 4, the rotation of the operation lever 6 in the direction b is locked. Thus, the gripping state of the finger 4 can be maintained.
[0051]
As shown in FIG. 3A, when the ratchet release switch 7 is in the retracted position, the engagement formed by bulging to the free end side of the elastically deformable locking piece 7D provided on the upper surface of the rear portion The portion 7E engages with the locking pin 21 protruding inside the right side portion 2B of the handle portion 2, and the ratchet release switch 7 is held in the retracted position.
[0052]
Next, when releasing the pair of fingers 4, when the operating portion 7B of the ratchet release switch 7 is pushed forward with a finger, the free end side of the locking piece 7D is elastically deformed and bent, and the engaging portion 7E is bent. After overcoming the locking pin 21, the ratchet release switch 7 moves to the forward position shown in FIG. 3B and is held in this position.
[0053]
At this time, the cam portion 7A provided on the ratchet release switch 7 pushes down the cam follower portion 18C of the ratchet 18 against the urging force of the ratchet spring 20, so that the ratchet 18 rotates counterclockwise about the shaft 19. Move.
[0054]
As a result, the claw t provided at the tip of the locking arm 18A of the ratchet 18 is separated from the ratchet teeth T of the operation lever 6, and the operation lever 6 can be rotated in the b direction, so that the pair of fingers 4 are opened. be able to.
[0055]
In this embodiment, the latch piece 7D and the latch pin 21 are used to hold the ratchet release switch 7 in the retracted position in FIG. 3A and the advanced position in FIG. These members are omitted, and instead of the cam portion 7A, when the cam portion 7A pushes down the cam follower portion 18C of the ratchet 18 at the position shown in FIG. 3B, the shallow recess portion into which the cam follower portion 18C is fitted is formed in the cam portion 7A. The release position of the ratchet 18 may be maintained.
[0056]
【The invention's effect】
As described above, according to the invention described in claim 1, the cam portion provided on the ratchet release switch pushes the cam follower portion of the ratchet by displacing the ratchet release switch to the ratchet release position, so that the ratchet pawl is moved. Because it can be reliably detached from the ratchet teeth of the operating lever, the ratchet pawls will come off the ratchet teeth unless the operating lever is rotated once in the direction in which the finger closes, as with forceps using a conventional leaf spring ratchet. The operability can be improved without any problem.
[0057]
Compared to the conventional forceps with a ratchet mechanism, which uses the elasticity of the conventional ratchet to release the nail from the ratchet tooth, the ratchet nail is reliably detached from the ratchet tooth. Therefore, it is possible to prevent an accident that damages the body tissue by mistakenly pulling back the forceps in a state where the fingers are not opened due to a failure to remove the ratchet nail.
[0058]
In addition, the structure is such that the ratchet claw is pressed against the ratchet teeth using an independent ratchet spring without using a plate spring-like ratchet, so that the state in which the fingers grasp the tissue can be reliably maintained, and the claw and ratchet There is no risk of the fingers opening during surgery due to poor tooth engagement.
[0059]
According to the invention of claim 2, since the engagement holding means is provided, there is no possibility that the ratchet release lever moves from the release position due to the urging force or vibration of the ratchet spring acting on the ratchet. The sex can be increased.
[Brief description of the drawings]
FIG. 1 is a perspective view showing one embodiment of a forceps with a ratchet mechanism of the present invention.
2 is an exploded perspective view showing the internal structure of the forceps with a ratchet mechanism in FIG. 1. FIG.
3A and 3B are views showing the operation of the ratchet mechanism, where FIG. 3A shows a ratchet engaged state, and FIG. 3B shows a ratchet released state.
FIG. 4 is a perspective view showing an example of a conventional forceps with a ratchet mechanism.
5A and 5B are diagrams showing the operation of a ratchet mechanism in a conventional forceps with a ratchet mechanism, where FIG. 5A shows a ratchet engaged state and FIG. 5B shows a ratchet released state, respectively.
[Explanation of symbols]
1 Forceps with ratchet mechanism, 2 Handle part, 2A Finger ring, 2B Right part, 2C Left part, 3 Shaft part, 4 Finger, 5 Finger support part, 6 Operation lever, 6A Shaft hole, 6B Circular notch part, 6C Ratchet bar , 7 Ratchet release switch, 7A Cam part, 7B Operation part, 7C Guide part, 7D Locking piece, 7E Engagement part, 8 Rotation knob, 9 Terminal, 10, 11 Dowel hole, 12, 13 Dowel pin, 14 shaft, 15 fingers closing rod, 16 connecting pivots, 17 conductive plate, 18 ratchet DOO, 18A lever, 18B spring receiving portion, 18C cam follower portion, 19 shaft, 20 a ratchet spring, 21 the locking pin.

Claims (2)

It has an elongate shaft part to which a pair of freely openable and closable fingers for grasping body tissue is attached to the front end, and a handle part that is connected to the rear end of the shaft part and extends downward, and rotates to the handle part A ratchet mechanism having a structure in which the pair of fingers are opened and closed in conjunction with a pivoting operation of an operation lever that is freely pivotally supported, and the movement of the pair of fingers in the opening direction of the operation lever and the handle portion is prevented. In the provided forceps with a ratchet mechanism,
The ratchet mechanism is rotatably supported by a shaft in a handle portion , and is provided with at least a cam follower portion protruding from the shaft toward the shaft portion, and a claw protruding from the shaft toward the operation lever side. A ratchet having a lever portion,
A ratchet tooth provided on the operation lever, protruding toward the lever portion of the ratchet and formed into a sawtooth shape engaging with the claw;
An operating unit capable of operation with the finger exposed to the outside at a position close to the shaft portion at the front end of said handle portion, extending rearwardly from the operation portion projects toward the cam follower portion of the ratchet, said cam follower and a ratchet release switch having a part and the cam portion for sliding contact,
Said ratchet release switch has a first position for maintaining the engagement between the ratchet teeth and the pawl not interfere with the rotation of the ratchet, the pawl the cam portion presses the cam follower portion of the ratchet is the holding the handle portion freely displaceable between a forced second position which is separated from the ratchet teeth, and said first position and said operation portion in both the position of the second position and the handle portion A forceps with a ratchet mechanism, characterized in that there is an interval between which a finger can be inserted . The ratchet release switch is elastically engaged and held with the handle portion at each of the first position and the second position, and the engagement state can be forcibly released by operation of the operation portion. Joint holding means are provided,
The engagement holding means includes a handle portion side engaging portion provided on the handle portion, and a handle portion side engaging portion provided at the ratchet release switch side at the first position and the second position. The forceps with a ratchet mechanism according to claim 1, further comprising a ratchet release switch side engaging portion to be engaged.

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