JP2004344381A - Forceps plug of endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forceps plug which exhibits, with a small-sized and compact constitution, an enhanced function as a check valve composed of a slit and which can demonstrate the function in a stable state. <P>SOLUTION: A recessed part 34 is provided on a projection part 30 where the slit 33 of a valve member 21 detachably mounted on a plug main body 20 is formed. The recessed part 34 is provided with an annular inner wall 35 of a diameter larger than the length of the slit 33. Inside a cylindrical space surrounded by the annular inner wall 35, a conical projection part 36 is provided. For the conical projection part 36, the diameter of a bottom surface is made equal to the slit 33 and the height has a dimension which is almost the same as the depth of the recessed part 34 or to be slightly projected from the recessed part 34. The slit 33 is formed up to the tip of the conical projection part 36. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a forceps plug that is provided in an endoscope used for medical use and the like, and is detachably attached to a mouthpiece of a treatment tool introduction port in a treatment tool insertion channel for inserting forceps and other treatment tools. It is.
[0002]
[Prior art]
An endoscope that is inserted into a body cavity and performs a medical examination or the like has an insertion section into the body cavity connected to a main body operation section that is operated by an operator or the like by hand and furthermore, a light source is connected to the main body operation section. It is generally configured by connecting and providing a universal cord that is detachably connected to a device or the like. The distal end of the insertion unit includes an illumination unit for illuminating the inside of the body cavity, and an observation unit for inspecting the inside of the body cavity under illumination emitted from the illumination unit.
[0003]
For example, when an affected part or the like is found as a result of an inspection using an endoscope, a necessary treatment can be performed, and there is also a configuration in which tissue cells can be sampled. For this purpose, the endoscope is provided with a treatment tool insertion channel for inserting forceps and other treatment tools. The distal end of the treatment instrument insertion channel is open at the distal end of the insertion section together with the illumination section and the observation section. On the other hand, introduction of the treatment tool into the treatment tool insertion channel is performed on the main body operation unit side. For this purpose, a treatment instrument introduction port is formed in the main body operation unit or a connecting portion between the main body operation unit and the insertion unit.
[0004]
Since the pressure in the body cavity is higher than the atmospheric pressure, and the treatment tool insertion channel may also be used as a suction passage, the treatment tool introduction port cannot be always opened. For this purpose, it is common to provide a mouthpiece at the treatment instrument introduction port, attach a forceps plug, and seal the treatment instrument introduction port. When the treatment tool is used, it is common to provide a check valve on the forceps plug and open the check valve to insert the treatment tool, instead of removing the forceps plug from the base. It is a target. In addition, since the inside of the treatment tool insertion channel is washed each time it is used, the forceps stopper is detachably attached to the mouthpiece of the treatment tool introduction port.
[0005]
As a treatment tool inserted into the treatment tool insertion channel, a treatment tool having a large outer diameter such as a forceps may be inserted, or a treatment tool having a small outer diameter such as a tube may be inserted. is there. That is, the thickness of the treatment tool inserted into the treatment tool insertion channel varies depending on the type and the like. Ideally, the on-off valve provided on the forceps stopper is configured to be able to keep the periphery of the treatment tool in a sealed state even when the treatment tool is inserted. However, a forceps stopper that ensures a completely hermetic seal even when a thick treatment instrument close to the diameter of the treatment instrument introduction port is inserted or when a treatment instrument much smaller than that is inserted is still developed. It has not been.
[0006]
This type of forceps stopper is formed of an elastic member such as rubber, provided with a wall portion that covers the treatment instrument introduction port, a slit is formed so as to penetrate this wall portion, and a joining wall surface forming the slit is formed. By bringing them into close contact with each other, at the time of a suction operation or the like, a backflow prevention function of holding the treatment instrument introduction port in a closed state is exhibited, and the elastic member is deformed to separate the joint wall surface of the slit, thereby allowing the treatment instrument to be separated. Conventionally, a passage configured to form an insertion passage, and a throttle passage having an opening diameter smaller than the diameter of the treatment instrument introduction port is formed at a position on the front side in the insertion direction of the treatment instrument with respect to the portion where the slit is formed, is conventionally used. (For example, see Patent Document 1).
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 7-100097 (pages 2-4, FIG. 1, FIG. 3-5)
[0008]
[Problems to be solved by the invention]
In the forceps plug, in the check valve formed of a slit, the slit is pushed open each time the treatment tool is inserted, and the joining wall surface forming the slit slides on the outer peripheral surface of the treatment tool. Therefore, if the treatment tool is frequently inserted and removed, the joint wall surface will be deformed or damaged, and the backflow prevention function of the slit will be reduced. In particular, if the hardness of the elastic member as the material of the forceps plug varies, or if the processing accuracy of the slit changes, the stability of the sealing function of the slit when a high pressure is applied cannot be obtained.
[0009]
Here, when suction is performed from the inside of the body via the treatment instrument insertion channel, particularly when switching from a state in which suction is performed to a state in which suction is stopped, a high pressure acts on the forceps stopper. The treatment instrument insertion channel has a length equal to or longer than the entire length of the insertion portion, whereas the length of the conduit from the connection portion of the treatment instrument insertion channel to the suction passage to the treatment instrument introduction port is extremely short. It has become. When the suction operation is performed and the suction is stopped from a state in which the suction force of the suction substance to the suction passage side is acting in the treatment instrument insertion channel, the suction substance in the treatment instrument insertion channel is changed by the inertia force. Retraction into the insertion channel continues. As a result, the suction substance drawn in after the suction is shut off tends to flow toward the treatment instrument introduction port side, and high pressure acts on the forceps stopper.
[0010]
Even if such a high pressure acts on the slit, in order to stably exhibit the damping function of the suction substance and prevent the suction substance from oozing out of the forceps plug, the adhesion of the joining wall surface forming the slit is increased. There is a need. For this purpose, for example, it is conceivable to increase the thickness of the slit forming portion to increase the depth of the slit. However, simply increasing the depth of the slit improves the adhesion itself of the joining wall surface constituting the slit, but makes it difficult to insert a soft tube or the like. . In addition, the variation in the function based on the material and processing accuracy of the forceps stopper increases, and there is a problem that a stable backflow prevention function cannot be exhibited.
[0011]
The present invention has been made in view of the above points, and aims to enhance the function as a check valve formed by a slit by a small and compact structure, and to stabilize the check function. It is to be able to demonstrate in the state where it was done.
[0012]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a medical instrument comprising an elastic member, which is removably mounted on a treatment instrument introduction port of a treatment instrument insertion passage provided in an endoscope, and is provided with a lower end than the passage of the treatment instrument introduction port. A plug body provided with a throttle passage having a small hole diameter, and detachably connected to the plug body, the joint wall surfaces are always in close contact with each other, and the treatment tool is inserted by separating the joint wall surfaces. A forceps stopper for an endoscope comprising a valve member provided with a slit forming a passage, wherein the valve member is fitted in a compressed state to the stopper body, and the valve member has A concave portion having a predetermined depth is formed on the distal end surface of the plug body facing the throttle passage, and the concave portion has a cylindrical inner wall having a diameter larger than the length dimension of the slit. The above-mentioned slip A conical protruding portion having a bottom portion having a diameter substantially equal to the length dimension of the cylindrical inner wall and having a height dimension substantially equal to or greater than the depth dimension of the cylindrical inner wall; Is characterized in that it is formed so as to penetrate this conical projection.
[0013]
As described above, a slit is provided in the valve member as a backflow prevention valve for preventing backflow from the treatment instrument introduction port side, but in order to ensure the adhesion of the joining wall surface forming the slit, the slit is mechanically adhered. A part and a part that enhances adhesion by the action of pressure are formed. That is, since the valve member is fitted into the plug body in a compressed state in the portion of the slit up to the concave portion of the valve member, the joining wall surfaces forming the slit are crimped to each other. Such a pressing force does not act on the conical protrusion located in the recess, but receives a pressure acting on the treatment instrument introduction port during the suction operation and immediately after the suction is stopped. As a result, pressure acts in a direction in which the joining wall surfaces forming the slits formed in the conical projections are brought into close contact. A backflow prevention function is exerted by the balance between these two functions. Therefore, even if the hardness of the elastic member constituting the forceps plug changes, a stable backflow prevention function is exhibited. In other words, when the hardness of the forceps stopper is high, the mechanically strong pressure contact force of the joining wall surface forming the slit is maintained, and when the hardness of the forceps stopper is low, the mechanical pressure contact strength is reduced. In addition, the function of closely adhering the slit due to the pressure acting on the conical protrusion is improved.
[0014]
The valve member is detachably connected to the stopper main body, and when the treatment tool is pulled out from a state where the treatment tool is inserted through the forceps stopper, a force acts in a direction to separate the valve member from the stopper main body. To ensure that the valve member is firmly connected to the plug body and that the valve member does not deviate from the plug body even when the treatment tool is pulled out roughly, the fitting portion must be long. Therefore, if the conical projection is extended from the distal end surface of the valve member, the axial length of the forceps plug becomes extremely long. In particular, the height of the conical projection must be increased as much as possible in order to further enhance the sealing performance due to the pressure on the conical projection, so that the valve member is further elongated. However, since a concave portion is formed at the distal end of the valve member and the conical protrusion is provided in the concave portion, the fitting length of the valve member to the plug body is sufficiently long, and the height of the conical protrusion is high. Can be higher. It is desirable that the height of the conical protrusion is substantially equal to the depth of the recess, but it may protrude slightly from the recess.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, FIG. 1 shows an overall configuration diagram of an endoscope. In the drawing, 1 is a main body operation unit, 2 is an insertion unit, and 3 is a universal cord. The insertion portion 2 is a flexible portion 2a that bends freely along the bending direction when the insertion path in the body cavity is bent for most of the length from the connection side to the main body operation portion 1. An angle part 2b and a hard tip part 2c are sequentially connected to the soft part 2a. The rigid distal end portion 2c is provided with an illuminating portion and an observing portion (both not shown) constituting an endoscope observation means, and the angle portion 2b guides the rigid distal end portion 2c along an insertion path, In addition, in order to change the field of view of the endoscope observation means provided on the distal end hard portion 2c, a bending operation can be performed in a desired direction. The bending operation of the angle section 2c is performed by remote control by an angle operation means 4 provided in the main body operation section 1.
[0016]
The endoscope is not only capable of observing the inside of a body cavity, but also capable of performing a treatment on an affected part found as a result of an endoscopic examination, sampling a tissue, and the like, by the endoscope observation means described above. For this purpose, a treatment instrument introduction section 5 is provided in the main body operation section 1, and a treatment instrument insertion channel 6 is provided in a region from the treatment instrument introduction section 5 to the distal end hard portion 2c. The distal end of the channel 6 is open to the distal end hard portion 2c together with the illuminating unit and the observation unit. Accordingly, a desired treatment can be performed by inserting forceps and other treatment tools from the treatment tool introduction section 5 into the treatment tool insertion channel 6 and leading them out of the predetermined length from the hard distal end portion 2c.
[0017]
The treatment instrument insertion channel 6 is also used as a suction passage. Accordingly, a suction passage 7 is connected to the treatment instrument insertion channel 6 in the main body operation unit 1, and the suction passage 7 is guided from the main body operation unit 1 to the universal cord 3, and the distal end thereof has a suction pump having a suction pump. It is connected to a device (not shown). A suction valve 8 is provided in the main body operation unit 1 at a position halfway through the suction passage 7, and the suction operation can be performed by operating the suction valve 8 with a finger or the like. In other words, the treatment instrument insertion channel 6 and the suction device are normally shut off, and by operating the suction valve 8 so as to be pushed in, the suction device and the treatment instrument insertion channel 6 are connected, and the treatment instrument is inserted. A negative pressure suction force is applied to the insertion channel 6.
[0018]
With this configuration, if body fluids and dirt are present in the body cavity where the endoscopic examination is performed, the suction valve 8 is operated to discharge them from the treatment instrument insertion channel 6 to the suction passage. Removal to improve the observation conditions in the body cavity. In this state, the inside of the body cavity is inspected, and as a result, if an affected part or the like is present, forceps or other treatment tools are inserted from the treatment tool introduction unit 5 into the treatment tool insertion channel 6 to perform appropriate treatment. become.
[0019]
FIG. 2 shows a cross-sectional structure of a branch portion between the treatment instrument insertion channel 6 and the suction passage 7 of the main body operation unit 1. In FIG. 2, reference numeral 10 denotes a branch passage structure, and the base end of the treatment instrument insertion channel 6 and the distal end of the suction passage 7 are connected to the branch passage structure 10. Further, a connection pipe 11 extending obliquely upward toward the treatment instrument introduction section 5 is connected to the branch passage constituting body 10, and a base 12 is connected to the connection pipe 11. The base 12 protrudes from the treatment instrument introduction unit 5, and a forceps plug 13 is detachably attached to the protruding part of the base 12. Accordingly, a treatment tool such as forceps is guided from the base 12 through the connection pipe 11 to the inside of the branch passage member 10 via the forceps stopper 13, and is inserted into the treatment tool insertion channel 6 from the branch passage member 10. Will be.
[0020]
The base 12 attached to the treatment instrument introduction section 5 needs to be kept in a sealed state at least during a suction operation. When the treatment tool is used, it must be possible to insert the treatment tool as it is. Furthermore, since the inside of the treatment tool insertion channel 6 is contaminated with a suction substance such as body fluid, the inside of the treatment tool insertion channel 6 must be cleaned after use. Therefore, the forceps stopper 13 is detachably attached to the base 12 in the treatment instrument introduction part 5, and the forceps stopper 13 is always kept in a sealed state, and the treatment instrument can be inserted as needed. .
[0021]
FIG. 3 is a cross-sectional view showing a state where the forceps stopper 13 is attached to the base 12, and FIG. 4 is a plan view showing a state where the forceps stopper 13 is detached from the base 12. As is clear from these drawings, the forceps stopper 13 is entirely formed of an elastic member such as rubber, has a stopper body 20 and a valve member 21, and is provided between the stopper body 20 and the valve member 21. Are connected by a flat band-shaped connecting strip 22 for folding. The plug body 20 and the valve member 21 can be formed as separate members.
[0022]
The plug body 20 is formed of a substantially cylindrical member as a whole, is formed with a first annular projecting portion 23 projecting inward from one end side inward, and a throttle passage 24 is formed at the center in the middle portion. Is formed, and a second annular projecting portion 26 serving as a locking portion of the valve member 21 is formed at the other end. A first annular recess 27 is provided between the first annular protrusion 23 and the partition 25, and a second annular recess is provided between the partition 25 and the second annular protrusion 26. 28 are formed.
[0023]
On the other hand, the valve member 21 is formed by connecting a protruding portion 30 from the end face of the main body plate 29, and an annular groove 31 is formed on the outer peripheral surface of the protruding portion 30. Accordingly, the valve member 21 has its protruding portion 30 fitted into the second annular concave portion 28 of the plug body 20, and the upper and lower walls of the annular groove 31 form the second annular projecting portion of the plug body 20. The part 26 is fixed so as to sandwich it. Further, in the main body plate 29, a treatment tool guide portion 32 having a substantially concave hemispherical shape is formed on a surface opposite to the projecting direction of the projection portion 30. Is formed. The slit 33 has a predetermined length in a direction orthogonal to the extending direction of the connecting strip 22.
[0024]
Then, the end face of the protruding portion 30 of the valve member 21 opposite to the side on which the treatment tool guide portion 32 is provided, that is, the valve member 21 faces the partition wall 25 of the plug main body 20 in a state where the valve member 21 is incorporated in the plug main body 20. A concave portion 34 is formed on the distal end surface. The recess 34 has a depth that does not reach the position where the annular groove 31 is provided, and has an annular inner wall 35 having a diameter larger than the length of the slit 33.
[0025]
A conical projection 36 is provided in a cylindrical space surrounded by the annular inner wall 35. As is apparent from FIG. 5, the conical protrusion 36 has a bottom surface having a diameter of the slit 33 and a height substantially equal to the depth of the concave portion 34 or from the concave portion 34. It has a slightly projecting dimension. The slit 33 is formed up to the tip of the conical protrusion 36.
[0026]
In the forceps plug 13 configured as described above, the portion of the first annular concave portion 27 in the plug main body 20 is engaged with the fixing protrusion 14 provided at the tip of the base 13, so that the forceps plug 13 Is detachably attached to the base 13. In addition, as will be described later, the valve member 21 of the forceps stopper 13 is attached to and detached from the stopper main body 20, and the connection strength between the stopper main body 20 and the base 13 at the time of attachment is determined by the connection strength of the valve member 21 to the stopper main body 20. To be higher. Therefore, the plug 13 is attached to the base 13 such that the portion of the first annular projection 23 and the first annular recess 27 of the plug main body 20 is considerably compressed and deformed.
[0027]
The valve member 21 is detachably mounted in a state where the plug body 20 is mounted on the base 13 as described above. Then, in order to exhibit a function of holding stably in the mounted state and preventing the valve member 21 from being detached unnecessarily when inserting or removing a treatment tool such as forceps, a locking portion of the stopper main body 20 is formed. The two annular projections 26 are sandwiched between the main body plate 29 of the valve member 21 and the projection 30 facing the main body plate 29. Accordingly, the thickness of the second annular projection 26 is larger than the width of the annular groove 31 formed between the main body 29 and the projection 30. As a result, when the valve member 21 is mounted, the second annular projecting portion 26 is compressed, and the valve member 21 is held in a state of being connected to the plug body 20 by this compression. In addition, the airtightness during that time is improved.
[0028]
The second annular projection 26 constituting the plug main body 20 is sandwiched between the lower surface of the main body plate 29 of the valve member 21 and the projection 30 from above and below in an elastically deformed state. 21 is held so as to be substantially integral with the plug body 20 so as not to move unintentionally in the fitted state. Therefore, as shown in FIG. 6, when inserting and removing various treatment tools through the slit 33 of the valve member 21 and the restricting passage 24 of the plug body 20, the valve member 21 is relatively moved with respect to the plug body 20. No unusual movements occur.
[0029]
As a result, a treatment tool having a strong waist and a large outer diameter, such as a forceps having a gripping claw at the distal end, is rapidly pulled out of the treatment tool introduction section 5 from a state in which the treatment tool is inserted through the treatment tool insertion channel 6. Even when operated, there is no relative movement between the valve member 21 and the plug body 20, and the fitting state between the second annular projection 26 and the annular groove 31 is always stable. become. Therefore, even if the treatment tool is repeatedly inserted and removed, no deformation or the like occurs in the fitting portion, and the on-off valve 21 does not deviate from the plug main body 20.
[0030]
Here, in a state where the forceps stopper 13 is attached to the base 12 of the treatment instrument introduction unit 5, if the joining wall surfaces 33a on both sides constituting the slit 33 provided in the valve member 20 do not surely adhere to each other. No. Moreover, the slit 33 is opened and closed each time a forceps or other treatment tool is inserted, and the treatment tool slides along the joint wall surface 33a. In order to make this sliding smooth, measures such as impregnating the forceps stopper 13 with a lubricant can be taken. However, when the treatment tool is repeatedly inserted, the joint wall surface 33a is worn or deformed. As a result, the sealing performance between the joining wall surfaces 33a of the slit 33 is reduced, and a gap is generated therebetween.
[0031]
As described above, even when the treatment tool is repeatedly inserted, the treatment tool insertion channel 6 is also used as a suction passage by keeping the joint wall surfaces 33a, 33a constituting the slit 33 in a sealed state, and suction from the body. Even if a negative pressure is applied to the inside of the treatment instrument insertion channel 6 when sucking the substance, the airtightness of the slit 33 is ensured so that the sucked substance does not seep out of the forceps plug 13. For this reason, the backflow preventing function of the slit 33 is such that the upper wall is mechanically brought into close contact with the joining wall surfaces 33a, 33a by the action of external force, and the lower wall is provided with a pressing force when pressure is applied to the inside. Is working.
[0032]
That is, since the portion of the annular groove 31 of the projecting portion 30 of the valve member 21 is incorporated so as to be compressed by the second annular projecting portion 26 of the plug member 20, the joining wall surface 33a , 33a is improved. Accordingly, mechanical adhesion due to the pressing force is secured between the joining wall surfaces 33a, 33a of the slit 33 for a predetermined length from the upper side U, that is, the treatment tool guide portion 32, of the slit 33.
[0033]
At the lower side D of the slit 33, that is, at the portion of the conical protruding portion 36, no external force acts on the joining wall surfaces 33a, 33a in a direction in which they are in close contact with each other. However, as described above, when the suction is stopped from the suction state, a high pressure acts on the treatment instrument introduction portion 5. Therefore, this pressure acts on the inclined outer peripheral surface of the conical protrusion 36. become. As a result, a component force is generated on the outer peripheral surface in a direction of bringing the joining wall surfaces 33a into close contact with each other in accordance with the inclination angle, and the adhesive force increases as the pressure increases.
[0034]
The tightness of the conical protrusion 36 increases as the apex angle decreases. Since the bottom surface of the conical protrusion 36 substantially matches the length of the slit 33, the height of the conical protrusion 36 must be reduced to reduce the apex angle of the conical protrusion 36. Need to be as large as possible. Since the conical protruding portion 36 is provided in the concave portion 34 formed in the protruding portion 30 of the valve member 21, the length of the valve member 21 as a whole in the axial direction can be reduced, and the size can be reduced. .
[0035]
As described above, since the backflow prevention function is exhibited by the balance between the adhesion by the compressive force to the slit 33 and the adhesion obtained by the action of the pressure, the backflow prevention function is further improved. In addition, even if the degree of elasticity of the forceps stopper 20 and the processing accuracy of the slit 33 vary somewhat, a stable backflow prevention function can be exhibited.
[0036]
In addition, when the pressure in the treatment instrument introduction section 5 increases while the treatment instrument T is inserted into the slit 33, as shown in FIG. , The sealing property of the slit 33 is improved. When the outer diameter of the treatment tool T is larger than the inner diameter of the throttle passage 24, the sealability is ensured at this position. Therefore, the sealability of the slit 33 is necessary when the treatment tool is inserted. When the treatment tool T having such a small diameter is inserted, as shown in FIG. 6, the adhesion at the conical protruding portion 36 of the slit 33 is more improved. Since the height is increased, even when the treatment tool T is inserted, it is possible to reliably prevent body fluids and the like from flowing out of the treatment tool introduction unit 5.
[0037]
【The invention's effect】
As described above, according to the present invention, with a small and compact configuration, the function as a check valve formed by a slit is enhanced, and the check valve function is exhibited in a stable state. .
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an example of an endoscope to which a forceps stopper of the present invention is attached.
FIG. 2 is a cross-sectional view of a main part of a main body operation unit in a state where a forceps stopper according to an embodiment of the present invention is attached to a treatment instrument introduction unit.
FIG. 3 is a cross-sectional view of a state in which a forceps plug is inserted into a treatment instrument introduction unit in FIG.
FIG. 4 is a plan view of a forceps stopper.
FIG. 5 is a cross-sectional view taken along a line XX in FIG. 3 in a state where the plug body and the valve member are combined.
FIG. 6 is a cross-sectional view in a state where a treatment tool is inserted into a forceps stopper.
7 is a sectional view of the valve member taken along the line YY in FIG. 6;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body operation part 2 Insertion part 5 Treatment tool introduction part 6 Treatment tool insertion channel 7 Suction passage 12 Cap 13 Forceps stopper 20 Plug main body 21 Valve member 23 First annular protrusion 24 Restriction passage 25 Partition 26 Second annular Projection 27 First annular recess 28 Second annular recess 29 Body plate 30 Projection 31 Annular groove 33 Slit 33a Joining wall surface 34 Recess 35 Annular inner wall 36 Conical projection

Claims (1)

A stopper body which is entirely formed of an elastic member, is detachably attached to the treatment instrument introduction port of the treatment instrument insertion passage provided in the endoscope, and has a throttle passage having a smaller diameter than the passage of the treatment instrument introduction port; A valve member having a slit which is detachably connected to the plug main body and in which the joint walls are always in close contact with each other and which is separated from the joint walls to form a passage for inserting a treatment instrument. In the forceps stopper of the endoscope,
The valve member is fitted in the plug body in a compressed state,
And, in the valve member, a concave portion having a predetermined depth is formed on a distal end surface side facing the throttle passage of the plug body,
This recess has a cylindrical inner wall having a diameter larger than the length of the slit,
A conical shape having a bottom surface having a diameter substantially matching the length of the slit inside the cylindrical inner wall, and having a height substantially equal to or greater than the depth of the cylindrical inner wall. A protrusion is formed,
The forceps stopper for an endoscope, wherein the slit is formed so as to penetrate the conical protrusion.

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