JP2002011019A - Forceps with ratchet system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forceps with ratchet system which can surely release a ratchet system with high reliability and excellent operation property. SOLUTION: The forceps with ratchet system comprises a lever part 18A with a click t which is rotatably supported with an axis by a handle part 2 of a forceps 1 rotation freely, a ratchet 18 with a cam follower part 18C, a ratchet spring 20 which forces the ratchet to rotate in the direction that the click engages with ratchet teeth T mounted on a operation lever 6, and a ratchet releasing switch comprising a cam part 7 which contacts with the cam follower part while sliding, and an operation part 7B exposed outside the handle part. The ratchet releasing switch is supported by the handle part movement freely between the first position where rotation of the ratchet is not prevented, and the second position where the cam part pushes the cam follower part of the ratchet and the click is compulsively detached from the ratchet teeth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forceps having a ratchet mechanism, and more particularly to a structure of a forceps suitably used for an endoscopic operation.

[0002]

2. Description of the Related Art In recent years, in surgical operations for treating diseases such as the chest and abdomen, the risk of infection is smaller than in open surgery, and the period for healing wounds due to the operation is shortened. The number of cases where endoscopic surgery is performed is increasing.

[0003] In endoscopic surgery, a small hole is made in the body surface of a patient with a trocar, a cannula tube is inserted into the body cavity, and an endoscope is inserted into the body cavity through the cannula tube to observe a surgical site. Surgical operations such as excision and suturing of the affected part are performed by inserting forceps, clips, automatic suturing devices and the like for endoscopic surgery into another body cavity from another cannula tube.

FIG. 4 is a perspective view showing an example of a forceps conventionally used in such an endoscopic operation. This type of forceps A1 has an opening and closing for grasping a body tissue such as an internal organ or a blood vessel at the tip. An elongated shaft portion A having a pair of free fingers A2
3 and a handle portion A4 held and held by hand.

[0005] A finger ring A5 for inserting and holding a finger when a surgeon performs an operation is formed on the handle portion A4, and an operation lever A6 is located behind the finger ring A5 in a position hidden behind the handle portion A4. It is attached rotatably around the supporting shaft.

The opening / closing operation of the operation lever A6 about the support shaft with respect to the finger hanging ring A5 is configured to interlock with the opening / closing operation of the pair of fingers A2 at the tip of the shaft portion A3. When rotated in the approaching direction, the pair of fingers A2 are closed to grasp body tissue.

[0007] By rotating a rotary knob A7 provided on the upper front end of the handle A4 with a finger, the shaft A
3 and the direction of the pair of fingers A2
It can be rotated around the central axis of.

A ratchet mechanism A8 is incorporated between the operation lever A6 and the finger ring A5 of the handle portion A4 for restraining the operation of opening the pair of fingers A2. Even when the operation lever A6 is operated and the tissue is grasped by the pair of fingers A2, even if the hand is released from the operation lever A6, the state where the pair of fingers A2 grasps the tissue is maintained.

The ratchet mechanism A8 includes an operation lever A
6, a ratchet bar A9 protruding from the finger ring A5 along a circumferential direction about the center of rotation thereof, and an elastically deformable plate having one end fixedly supported on the finger ring A5 at one end. Spring-shaped ratchet A10
And a ratchet release lever A11.

On the free end side of the ratchet A10, a sawtooth ratchet tooth T formed on a ratchet bar A9 is formed.
And a ratchet t is provided so as to face the ratchet releasing lever A11 as shown in FIG.
When the ratchet A10 is tilted toward the operation lever A6, the ratchet A10 is lifted upward by the cam surface c formed on the ratchet release lever 11, and the pawl t is pressed against the ratchet teeth T of the ratchet bar A9. ing.

In this state, when the operating lever A6 is turned in the direction in which the pair of fingers A2 shown in FIG. 4 is closed, the ratchet A10 is elastically bent, and the claws t climb over the ratchet teeth T one after another to operate at a desired position. When the force applied to the lever A6 is released, the pawl t becomes a ratchet A10 having a spring property.
Engages with one of the ratchet teeth T by the elastic restoring force of
The reverse movement of the operation lever A6 from that position is prevented.

Next, when the pair of fingers A2 is opened, as shown in FIG.
11 is tilted about the support shaft A12 to the side opposite to the operation lever A6 side.

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 disengaged. The turning operation in the direction to open the pair of fingers A2 is enabled.

[0014]

In the conventional forceps with a ratchet mechanism having the above-described structure, the operation of releasing the ratchet pawl from the ratchet teeth is performed by the elastic restoring force of the ratchet formed like a leaf spring. I use it.

On the other hand, since the reaction force in the direction of always opening from the tissue side acts on the pair of fingers in the state where the body tissue is grasped, the serrated ratchet teeth and the ratchet claws firmly bite each other. It is crowded.

[0016] As a result, merely operating the release lever to release the ratchet mechanism makes it difficult for the ratchet pawl to separate from the ratchet teeth, weakens the ratchet's spring properties, or causes the pair of fingers to firmly grip the tissue. In this case, there is a problem that the ratchet pawl cannot be removed from the ratchet teeth unless the operation lever is once turned in the direction in which the finger is closed.

Since the pair of fingers, which are inserted into the patient's body and grip the body tissue, cannot be directly seen by the surgeon operating the forceps, the release lever is operated to operate the fingers. Attempting to pull the forceps out of the patient's body with the intention to release it could actually drag the body tissue and cause serious damage, as the pair of fingers still grips the body tissue.

Accordingly, the present invention has been made to solve the above-mentioned problems in the prior art, and to provide a highly reliable and excellent operability forceps with a ratchet mechanism capable of reliably releasing the ratchet mechanism. Aim.

[0019]

In order to achieve the above object, a forceps with a ratchet mechanism according to the present invention comprises an elongated shaft portion having a pair of openable and closable fingers attached to a front end for grasping body tissue; A handle connected to the rear end of the handle, and the pair of fingers opens and closes in conjunction with the rotation of an operation lever rotatably supported by the handle. A forceps with a ratchet mechanism having a structure in which a ratchet claw provided on the handle portion side is engaged with the provided serrated ratchet teeth to prevent the pair of fingers from moving in the opening direction. A ratchet having a cam follower portion and a lever portion formed with a pawl that is movably supported, and a ratchet spring that constantly biases the ratchet in a direction in which the pawl is engaged with the ratchet teeth; A cam portion for serial cam follower portion and the sliding contact of the ratchet, and a ratchet release switch having an externally exposed can be operated by the finger operation portion of the handle portion.

In the forceps with a ratchet mechanism, the ratchet release switch is provided in a first position which does not hinder the rotation of the ratchet, and the cam portion presses the cam follower portion of the ratchet to forcibly separate the pawl from the ratchet teeth. The handle is movably held between the second position and the second position.

In the forceps with a ratchet mechanism of the present invention, the ratchet release switch is elastically engaged and held at each of the first position and the second position, and the engaged state is changed by operating the operation portion. It is desirable to have an engagement holding means that can be forcibly released.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The forceps with a ratchet mechanism of the present invention can be used in the same manner as conventional forceps of this type.
A surgeon who uses this inserts the shaft into the patient's body cavity from a cannula tube previously inserted into a hole made in the patient's chest or abdomen with a trocar.

When inserting the shaft of the forceps into the cannula tube, the pair of fingers are closed once, and these fingers protrude from the tip of the cannula tube in the patient's body and reach the vicinity of the body tissue to be grasped. Then, the surgeon rotates the operation lever to open the finger.

Next, the ratchet release switch is switched to a position (first position) that does not hinder the rotation of the ratchet, and then the operating lever is operated to close the pair of fingers and grasp the body tissue.

In this operation, the ratchet pawl moves while climbing over the serrated ratchet teeth provided on the operation lever, and the ratchet spring biasing the ratchet at a position where the hand of the operation lever is released. As a result, the pair of fingers engage with one of the ratchet teeth, and are held in a state of firmly grasping the body tissue.

Next, when the pair of fingers is opened to release the grasping tissue and the forceps are pulled out of the patient,
The surgeon first releases the ratchet release switch to the release position (second position).
Position).

Then, the cam portion provided on the ratchet release switch pushes the cam follower portion of the ratchet, rotates the ratchet around its support shaft against the urging force of the ratchet spring, and forcibly disengages the pawl from the ratchet teeth. Let go.

As a result, the operating lever can freely rotate, and the gripping force of the finger that has gripped the body tissue is also lost. Here, the surgeon can once open the finger to release the body tissue, and then close the finger again, so that the shaft of the forceps can be pulled out of the patient through the cannula tube.

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 rotatable about one support shaft.

In any case, the cam portion provided on the ratchet release switch does not interfere with the cam follower portion of the ratchet, and the first position in which the ratchet can be freely rotated, and the cam portion has the cam follower. It is sufficient that the ratchet releasing switch can be displaced between the second position where the ratchet pawl is held apart from the ratchet teeth.

The ratchet release switch is elastically engaged and held at each of the first position and the second position, and when the switch is displaced from one position to the other position, the operation portion is moved. It is desirable to provide an engagement holding means that can be pushed by a finger to forcibly release the engagement state at each position.

As the engagement holding means, for example, a ratchet release switch is formed integrally with a locking piece elastically deformable and deformable in a direction perpendicular to the direction of its displacement, and protrudes from the free end side of the locking piece. When displacing the ratchet release switch from one position to the other position by enabling the engagement portion to be engageable with the engagement portion formed on the handle portion side on both sides of the first position side and the second position side The engaging piece on the handle side slides over the engaging section on the handle section so that the engaging piece flexes and can be configured to pass.

Further, an engaging portion is simply formed on the ratchet release switch side by protruding, and a resiliently deformable locking piece similar to the locking piece is provided on the handle portion side, and the engagement holding means is provided. You may comprise.

Further, a shallow recess in which the other falls into one of the contact surfaces of the cam portion of the ratchet release switch and the cam follower portion of the ratchet may be formed to have the function of the engagement holding means. Good.

[0035]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of a forceps with a ratchet mechanism used in an endoscopic operation, showing one embodiment of the present invention. The forceps with a ratchet mechanism (hereinafter, simply referred to as forceps) 1 has a finger hanging ring 2A. It has a handle portion 2 made of resin and a metal elongated shaft portion 3 protruding forward from the front end of the handle portion 2.

At the front end of the shaft portion 3, a finger supporting portion 5 on which a pair of fingers 4 is pivotally mounted so as to be openable and closable is attached, and the pair of fingers 4 is located behind the finger ring 2A of the bundle portion 2. The operation lever 6 which is rotatably supported by the lever is opened by rotating backward (direction a in the drawing) and closed by rotating forward (direction b in the drawing). .

A ratchet release switch 7 to be described later is provided below the front end of the handle portion 2 so as to be slidable substantially in the front-rear direction with respect to the handle portion 2. A finger rotation knob 8 is attached to the handle portion 2 above the ratchet release switch 7.

When the finger rotation knob 8 is rotated by hand, the shaft 3 and the finger support 5 are integrally rotated around the central axis of the shaft 3, and the orientation of the pair of fingers 4 is changed. Can be rotated to grasp tissue in the body in various directions.

A terminal 9 is provided on the top of the handle 2 so as to protrude rearward. The terminals 9 are electrically connected to the pair of fingers 4. When the terminals 9 are energized from an external power supply (not shown), the
An electric current is applied to the body tissue grasped by the operator to perform treatment such as hemostasis.

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 includes a right portion 2B including most of the finger hook ring 2A and a remaining left portion 2C. These two portions 2B and 2C are provided with small-diameter portions at both ends of the dowel pins 12 and 13 in dowel holes 10 and 11 formed at two opposing positions on the inside. Press-fit and can be assembled together.

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 inner surfaces of the dowel holes 10 and 11 are firmly frictionally engaged with each other. The two portions 2B and 2C constituting the handle portion 2 are firmly connected so as not to be separated in a normal use state.

The operating lever 6 has a shaft 14 protruding into the right side portion 2B of the handle portion 2 inserted into the shaft hole 6A, and is supported rotatably around the shaft 14. It has a circular notch 6B for rotatably holding a connecting pivot 16 attached to the rear end of a finger opening / closing rod 15 that slidably penetrates the inside of the portion 3.

The finger opening / closing rod 15 has a front end linked to the pair of fingers 4 and has a role of transmitting the turning operation of the operating lever 6 about the shaft 14 to these fingers 4 to perform the opening / closing operation. And the conductive plate 17
Near the rear end is electrically connected to the terminal 9 via
It has a role as a conducting conductor from the terminal 9 to the pair of fingers 4.

On the other hand, the operating lever 6 is integrally formed with a ratchet bar 6C having ratchet teeth T arranged in a saw-tooth shape on a circumference concentric with the shaft hole 6A. The ratchet bar 6 </ b> C is housed in the handle portion 2, and is arranged so that the ratchet teeth T face the claws t of the ratchet 18.

The ratchet 18 has a shaft 19 projecting in parallel with the shaft 14 inside the right side portion 2B of the handle portion 2.
The lever portion 18A, the spring receiving portion 18B, and the cam follower portion 18C having the claw t at the distal end portion are formed to protrude radially in three directions around the shaft 19. .

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 mounted on the ratchet 18 around the shaft 19 in FIG. By applying a clockwise moment, the pawl t is urged to always engage with the ratchet tooth T.

The cam follower portion 1 of the ratchet 18
The upper surface of 9C is arranged to face a cam portion 7A formed on the ratchet release switch 7. The ratchet release switch 7 includes an operation portion 7B exposed from the handle portion 2 for operating with a finger, and a left and right portion 2 of the handle portion 2.
A guide portion 7C is slidably engaged on both sides with guide grooves G formed on the inside of B and 2C so as to face each other.

FIG. 3A shows an engagement 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,
The cam portion 7A is located behind the cam follower portion 18C of the ratchet 18.

In this state, the ratchet 18 receives a clockwise moment from the ratchet spring 20 around the axis 19, the pawl t is constantly pressed against the ratchet teeth T, and the operation lever 6 is moved by the arrow a. It is rotatable in the direction, but is prevented from rotating in the direction of arrow b.

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 grasps the body tissue with the pair of fingers 4, the operation lever 6 rotates in the direction b. Is locked, so that the gripping state of the finger 4 can be maintained.

As shown in FIG. 3A, when the ratchet release switch 7 is in the retracted position, it is formed so as to bulge toward the free end side of the elastically deformable locking piece 7D provided on the rear upper surface. The engaging 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 at the retracted position.

Next, when releasing the pair of fingers 4, when the operating portion 7 B of the ratchet release switch 7 is pushed forward with a finger, the free end side of the locking piece 7 D is elastically deformed and bent.
When the engagement portion 7E gets over the locking pin 21, the ratchet release switch 7 moves to the forward position shown in FIG.
It is held in this position.

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 is rotated counterclockwise about the shaft 19. Rotate around.

As a result, the locking arm 18A of the ratchet 18
The claw t provided at the tip is separated from the ratchet teeth T of the operation lever 6, and the operation lever 6 can rotate in the direction b, so that the pair of fingers 4 can be opened.

In this embodiment, in order to hold the ratchet release switch 7 in the retracted position shown in FIG. 3A and the forward position shown in FIG.
1, but omits these members and replaces them with
When the cam portion 7A pushes down the cam follower portion 18C of the ratchet 18 at the position shown in FIG. 3B on the cam portion 7A, a shallow recess into which the cam follower portion 18C is fitted is formed in the cam portion 7A, and the ratchet 18 is released. May be held.

[0056]

As described above, according to the first aspect of the present invention, by displacing the ratchet release switch to the ratchet release position, the cam portion provided on the ratchet release switch is replaced by the cam follower portion of the ratchet. Since the ratchet claw can be reliably released from the ratchet teeth of the operation lever by pressing, the operation lever must be once turned in the closing direction of the finger as in the conventional forceps using a leaf spring-like ratchet, so that the ratchet teeth can be disengaged from the ratchet teeth. The operability can be improved without the ratchet claw not coming off.

Further, in comparison with a conventional forceps with a ratchet mechanism having a structure in which the nail is detached from the ratchet teeth using the elasticity of the conventional ratchet, the detachment of the ratchet claw from the ratchet teeth is improved. Since it is possible to reliably perform the operation, it is possible to prevent an accident in which body tissue is damaged by mistakenly pulling back the forceps in a state where the finger is not opened due to a failure in detaching the ratchet claw.

Also, since the ratchet pawl is pressed against the ratchet teeth using an independent ratchet spring without using a leaf spring-like ratchet, it is possible to reliably maintain the state in which the finger grasps the tissue. There is no danger that the fingers will open during surgery due to poor engagement between the pawl and the ratchet teeth.

According to the second aspect of the present invention, the provision of the engagement holding means may cause the ratchet release lever to move from the release position due to the urging force or vibration of the ratchet spring acting on the ratchet. And reliability can be further improved.

[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.

FIG. 2 is an exploded perspective view showing an internal structure of the forceps with a ratchet mechanism in FIG.

FIG. 3 is a view showing the operation of the ratchet mechanism;
(A) shows the ratchet engaged state, and (B) shows the 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 an operation of a ratchet mechanism in a conventional forceps with a ratchet mechanism, wherein FIG. 5A shows a ratchet engaging state, and FIG. 5B shows a ratchet releasing state.

[Explanation of symbols]

1 forceps with ratchet mechanism, 2 handle part,
2A finger ring, 2B right part, 2C
Left part, 3 shafts, 4 fingers, 5 finger support, 6 control lever, 6A shaft hole,
6B circular cutout, 6C ratchet bar, 7
Ratchet release switch, 7A cam, 7B
Operation part, 7C guide part, 7D locking piece, 7
E Engagement part, 8 rotation knob, 9 terminals, 1
0, 11 dowel hole, 12, 13 dowel pin, 14
Shaft, 15 Finger opening and closing rod, 16
Connection pivot, 17 conductive plate, 18 ratchet claw, 18A lever part, 18B spring receiving part,
18C Cam follower, 19 axes, 20 ratchet spring, 21 locking pin.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4C060 GG22 GG28 GG30 MM24 MM25 MM26 4C061 AA22 AA24 BB00 CC00 DD00 GG15

Claims (2)

[Claims] 1. An elongated shaft portion having a pair of openable and closable fingers for grasping body tissue at a front end thereof, and a handle portion connected to a rear end of the shaft portion. The pair of fingers opens and closes in conjunction with the rotation of the operation lever that is movably supported, and the ratchet claw provided on the handle portion side is provided on the saw-like ratchet teeth provided on the operation lever. A ratchet mechanism-equipped forceps having a structure for engaging and preventing movement of a pair of fingers in an opening direction, wherein a ratchet rotatably supported by a handle portion and having at least a cam follower portion and a lever portion provided with a claw. A ratchet spring which constantly rotates and biases the ratchet in a direction in which the pawl engages with the ratchet teeth; a cam portion which is in sliding contact with a cam follower portion of the ratchet; A ratchet release switch having an operation portion exposed to the user and operated by a finger, wherein the ratchet release switch has a first position that does not hinder the rotation of the ratchet, and the cam portion presses the cam follower portion of the ratchet. The forceps with a ratchet mechanism, wherein the forceps are held by the handle portion so as to be displaceable between a second position for forcibly separating the pawl from the ratchet teeth. 2. An engagement holding means which elastically engages and holds a ratchet release switch at each of a first position and a second position, and forcibly releases the engagement state by operating an operation portion. The forceps with a ratchet mechanism according to claim 1, further comprising: