JP7181393B2 - incision instrument - Google Patents

Description

The present disclosure relates to lancing instruments.

2. Description of the Related Art As an incision instrument for incising a sphincter muscle or the like, there is known one in which a knife wire is passed through a catheter.

US Pat. No. 5,400,000 discloses an apparatus comprising a catheter, a cutting wire threaded through the catheter, and a handle for actuating the cutting wire from the proximal end of the catheter. In this device, a cutting wire is attached to the catheter at the distal end of the catheter, and rotation of the handle relative to the proximal end of the catheter rotates the cutting wire, thereby causing the distal portion of the catheter to move. configured to rotate. This device also has a rotation lock that prevents rotation of the catheter, and when a rotation operation is performed to rotate the handle, the inhibition of rotation by the rotation lock is released.

Japanese Patent No. 4896351

In Patent Literature 1, a rotation lock is activated when the handle is not rotated, and the rotation lock is released by performing a rotation operation on the handle. For this reason, there is a problem in that a feeling of resistance is generated in the rotating operation, and it cannot be easily operated with one hand. In addition, repeated rotation operations may wear the rotation lock, resulting in malfunction of the rotation lock.

An object of the present disclosure is to provide an incision instrument capable of suppressing wear of a locking mechanism while improving operability.

An incision instrument according to one embodiment of the present invention comprises a hollow shaft having a lumen; a fixed knife wire; an outer handle which is connected to the proximal end of the hollow shaft and has through-holes which are open at the distal and proximal ends and communicate with the lumen; and arranged in the through-hole from the proximal side. an inner handle to which the proximal end of the knife wire is connected; the outer handle has a lock mechanism having a contact portion capable of coming into contact with the inner handle; Relative movement of the inner handle with respect to the outer handle is restricted by the contact portion contacting the inner handle, and the contact portion of the lock mechanism is released from contact with the inner handle, The inner handle is allowed to move relative to the outer handle.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress wear of a lock mechanism, improving operability.

1 is a schematic cross-sectional view that schematically illustrates an incision instrument according to an embodiment of the present disclosure; FIG. 4 is an enlarged side view showing part of the side surface of the outer handle; FIG. FIG. 2 is a cross-sectional view taken along line III-III of FIG. 1; FIG. 4 is a side view showing the side surface of the inner handle; FIG. 4 is a diagram showing an example of the state of the tip of a hollow shaft; FIG. 10 is a diagram showing another example of the state of the tip of the hollow shaft; It is a figure which shows the state of the front-end|tip part of a hollow shaft. FIG. 4 is a cross-sectional view showing another example of the outer handle; FIG. 4 is a cross-sectional view showing another example of the outer handle; FIG. 4 is a cross-sectional view showing another example of the outer handle; FIG. 4 is a cross-sectional view showing another example of the outer handle;

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view schematically showing an incision instrument according to one embodiment of the present disclosure. The lancing instrument 100 shown in FIG. 1 has a hollow shaft 1 , a connector 2 , an outer handle 3 , an inner handle 4 and a knife wire 5 .

The hollow shaft 1 is a tubular member having a lumen 11 through which the knife wire 5 is passed. The lumen 11 extends axially in a substantially central portion of the cross section. A slit 12 communicating with the lumen 11 is formed at the tip of the hollow shaft 1 . A portion of the knife wire 5 inserted through the lumen 11 is exposed from the slit 12 .

The material constituting the hollow shaft 1 preferably has antithrombogenicity, flexibility and biocompatibility. Examples thereof include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin and fluororesin. or a metal material such as a hypotube.

A connector 2 for connecting the hollow shaft 1 and the outer handle 3 is connected to the base end of the hollow shaft 1 . The connector 2 has a body portion 21 which is a substantially cylindrical member, and a branch portion 23 formed on the side surface of the body portion 21 . A through hole 22 is formed in the main body portion 21 and a hole portion 24 is formed in the branch portion 23 .

A distal end portion of the main body portion 21 is connected to a proximal end portion of the hollow shaft 1 and extends along the axial direction. The through hole 22 has openings at the distal end and the proximal end of the body portion 21 and extends along the axial direction. The through-hole 22 communicates with the lumen 11 of the hollow shaft 1 via an opening on the distal end side. The knife wire 5 is inserted through the through hole 22 .

The branch portion 23 extends obliquely rearward from the side surface of the main body portion 21 . A hole portion 24 formed in the branch portion 23 has an opening at the proximal end of the branch portion 23 and communicates with the through hole 22 of the main body portion 21 on the side opposite to the opening. A member other than the knife wire 5 can be inserted into the lumen 11 of the hollow shaft 1 via the hole 24 and the through hole 22 .

The outer handle 3 and the inner handle 4 are connected to the hollow shaft 1 via the connector 2 and constitute a handle for manipulating the knife wire 5 inserted through the lumen 11 of the hollow shaft 1 .

The outer handle 3 is connected to the proximal end portion of the connector 2 (specifically, the body portion 21 ), and is connected to the proximal end portion of the hollow shaft 1 via the connector 2 . The outer handle 3 is preferably made of a flexible (elastic) material such as resin. Materials for the outer handle 3 include, for example, ABS resin, polycarbonate, acrylic, and the like.

A through hole 31 through which the knife wire 5 is inserted is formed in the outer handle 3 . The through-holes 31 have openings at the distal and proximal ends of the outer handle 3 and extend along the axial direction. The through hole 31 communicates with the through hole 22 of the connector 2 via the opening on the distal end side, and communicates with the lumen 11 of the hollow shaft 1 via the through hole 22 . The through hole 31 has a first through hole 31a formed on the distal end side of the outer handle 3 and a second through hole 31b formed on the proximal end side. communicate in series along the axial direction. The inner diameter of the second through hole 31b is larger than the inner diameter of the first through hole 31a.

A concave portion 32 is formed along the circumferential direction on the inner peripheral surface forming the through hole 31 (specifically, the inner peripheral surface forming the second through hole 31b). In the illustrated example, a plurality of recesses 32 are formed along the axial direction, that is, the extending direction (major axis direction) of the through hole 31 .

2 is an enlarged side view showing the side of the outer handle 3 in a portion corresponding to area A in FIG. 1, and FIG. 3 is a cross-sectional view of the outer handle 3 taken along line III-III in FIG. .

As shown in FIGS. 2 and 3, the outer handle 3 is formed with a slit 33 extending in the axial direction, that is, along the extending direction of the through hole 31 . The slit 33 has a structure that allows the inner diameter of the through hole of the outer handle 3 to be varied, and constitutes a lock mechanism having a contact portion that can contact the inner handle 4 . Specifically, the slit 33 causes the inner peripheral surface forming the through hole 31 of the outer handle 3 to abut against the inner handle 4 to limit the relative movement of the inner handle 4 with respect to the outer handle 3 . The inner peripheral surface forming the through hole 31 of the outer handle 3 serves as a contact portion that contacts the inner handle 4 . The slit 33 communicates with the through hole 31 . In the illustrated example, the slit 33 extends from the proximal end of the outer handle 3 to the front of the first through hole 31a and communicates with the second through hole 31b. In the illustrated example, two slits 33 are formed, and the slits 33 are formed at positions facing each other with the through hole 31 interposed therebetween.

4 is a side view showing the outer shape of the inner handle 4. FIG. As shown in FIGS. 1 and 4 , the inner handle 4 has an insertion portion 41 inserted into the through hole 31 of the outer handle 3 and a grip portion 42 provided at the proximal end of the insertion portion 41 . The outer diameter of the insertion portion 41 is smaller than the inner diameter of the second through hole 31b and larger than the inner diameter of the first through hole 31a. The insertion portion 41 is inserted into the second through hole 31b from the base end side of the outer handle 3 . The distal end portion of the insertion portion 41 may abut on the boundary portion 31c between the first through hole 31a and the second through hole 31b.

Also, the inner handle 4 is connected to the proximal end of the knife wire 5 . In the illustrated example, the inner handle 4 has a hole 43 with an opening at the distal end of the insertion portion 41, and the knife wire 5 is inserted inside the hole 43 (specifically, the bottom surface of the hole 43). A fixed terminal 44 is formed to be connected to the proximal end of the. The position of the fixed terminal 44 of the inner handle 4 is not limited to the above example.

A protrusion 45 is formed on the outer peripheral surface of the inner handle 4 along the circumferential direction. The convex portion 45 is formed so as to enter the concave portion 32 formed in the inner peripheral surface of the through hole 31 of the outer handle 3 . A plurality of protrusions 45 may be formed along the axial direction. In the illustrated example, two protrusions 45 are formed along the axial direction.

The grip portion 42 has a shape suitable for being gripped by a user. The outer diameter of the grip portion 42 is larger than the outer diameter of the second through-hole 31b in the illustrated example. A user grips the grip portion 42 to rotate the inner handle 4 and move it along the axial direction. The grip portion 42 may be formed with an anti-slip mechanism such as an uneven portion.

Materials for the inner handle 4 include, for example, ABS resin, polycarbonate, acrylic, and the like.

The knife wire 5 is an incision means for incising an object such as a sphincter muscle. During the incision, an electric current may be supplied to the knife wire 5 to heat the knife wire 5 .

The knife wire 5 is inserted through the lumen 11 of the hollow shaft 1 , the through hole 22 of the connector 2 , the through hole 31 of the outer handle 3 and the hole 41 of the inner handle 4 . The tip of the knife wire 5 is fixed to the tip of the hollow shaft 1 , and the proximal end of the knife wire 5 is fixed to the fixed terminal 44 of the inner handle 4 .

5 to 7 are diagrams showing the state of the tip portion of the hollow shaft 1, showing the side surface of the tip portion of the hollow shaft 1. FIG.

When the insertion portion 41 of the inner handle 4 is inserted all the way into the through hole 31 (specifically, the second through hole 31b) of the outer handle 3 as shown in FIG. has a substantially linear shape or a gently curved shape. In this state, when the inner handle 4 is moved forward (the base end side of the outer handle 3) along the extension direction of the through hole 31, the knife wire 5 fixed to the inner handle 4 is pulled forward. At this time, since the tip of the knife wire 5 is fixed to the tip of the hollow shaft 1, the tip of the knife wire 5 forms an arch as shown in FIG. In the state shown in FIG. 6, the protrusion 45 of the inner handle 4 and the recess 32 of the outer handle 3 are engaged with each other, suppressing axial movement of the inner handle 4 and fixing the axial position of the inner handle 4 . can do.

Further, when the inner handle 4 is rotated about the axial direction as the rotation axis, the knife wire 5 is rotated. At this time, since the tip of the knife wire 5 is fixed to the tip of the hollow shaft 1, as the knife wire 5 rotates, the tip of the hollow shaft 1 is twisted as shown in FIG. , and the direction in which the knife wire 5 is exposed changes.

By moving the inner handle 4 relative to the outer handle 3 as described above, the tip of the knife wire 5 and the hollow shaft 1 can be operated.

Further, when no force is applied to the outer handle 3, the slit 33 is open. In this state, when the outer handle 3 is gripped and a force F is applied to the outer handle 3 in a direction (perpendicular to the axis) substantially perpendicular to the extending direction of the slit 33 as shown in FIG. , the outer handle 3 is deformed so that the slit 33 is closed. As a result, the inner diameter of the through-hole 31 (second through-hole 31 b ) of the outer handle 3 is reduced by the width W of the slit 33 , and the inner peripheral surface of the through-hole 31 contacts the inner handle 4 . Therefore, friction is generated between the outer handle 3 and the inner handle 4, and relative movement of the inner handle 4 with respect to the outer handle 3 is suppressed.

When the force F is no longer applied to the outer handle 3, the slit 33 expands due to the elasticity of the outer handle 3, and the outer handle 3 returns to its original natural state. Since the slit 33 is widened in a natural state, the friction generated between the outer handle 3 and the inner handle 4 is small, the resistance to the rotation operation is low, and the inner handle 4 can move relative to the outer handle 3. It is said that

If the inner peripheral surface forming the through hole 31 of the outer handle 3 can be brought into contact with the inner handle 4 to restrict the relative movement of the inner handle 4 with respect to the outer handle 3, the slit 33 can be omitted. good. For example, by appropriately adjusting the degree of flexibility of the outer handle 3 , the inner peripheral surface forming the through hole 31 of the outer handle 3 can be brought into contact with the inner handle 4 without the slit 33 .

8 and 9 are diagrams showing another example of the cross-sectional structure of the outer handle 3 taken along line III-III in FIG. 8 and 9, the outer handle 3 is called an outer handle 51. As shown in FIG. The outer handle 51 has a pressing member 52 that penetrates from the outer peripheral surface to the inner peripheral surface of the outer handle 51 . The pressing body 52 has an outer peripheral end 52a positioned on the outer peripheral side of the outer handle 51 and an inner peripheral end 52b positioned on the inner peripheral side of the outer handle. A spring 53 that is an elastic body may be arranged between the outer handle 51 and the outer peripheral end 52 a of the pressing body 52 . 8 shows an example in which the spring 53 is not arranged, and FIG. 9 shows an example in which the spring 53 is arranged.

In the above structure, the outer peripheral end 52a of the push-down body 52 is pushed down, and a force is applied to the push-down body 52 in the pushing direction (the direction from the outer peripheral surface to the inner peripheral surface of the outer handle 51) D, whereby the push-down body 52 The inner peripheral end 52b of the outer handle 51 is pushed toward the inner handle 4 and can be brought into contact with the inner handle 4. As shown in FIG. Further, by releasing the pressing of the outer peripheral end 52 a of the pressing body 52 , the contact of the inner peripheral end 52 b of the pressing body 52 with the inner handle 4 is released. At this time, when the spring 53 is arranged, the spring 53 is compressed by pressing the outer peripheral end 52a of the pressing body 52, and the pressing of the outer peripheral end 52b of the pressing body 52 is released. , the spring 53 is extended.

10 and 11 are diagrams showing still another example of the cross-sectional structure of the outer handle 3 taken along line III-III in FIG. 10 and 11, the outer handle 3 is called an outer handle 56, and the inner handle 4 is called an inner handle 57. As shown in FIG. The outer handle 56 has a pressing body 55 that penetrates from the outer peripheral surface to the inner peripheral surface of each of the outer handle 56 and the inner handle 57 and is arranged in contact with the inner peripheral surface of the inner handle 57 . Specifically, the pressing body 55 has an outer peripheral end 55 a positioned on the outer peripheral side of the outer handle 56 and an inner peripheral end 55 b positioned on the inner peripheral side of the inner handle 57 . A spring 53 may be arranged between the outer handle 55 and the outer peripheral end 55 a of the pressing body 55 . 10 shows an example in which the spring 53 is not arranged, and FIG. 11 shows an example in which the spring 53 is arranged.

In the structure described above, in a natural state in which no force is applied to the outer handle 56, the pusher 55 is in contact with the inner peripheral surface of the inner handle 57, and a force is applied to the pusher 55 in the pushing direction D. By doing so, the pressing member 55 is separated from the inner peripheral surface of the inner handle 57. As shown in FIG. Therefore, in such a structure, the inner handle 57 is restricted from moving relative to the outer handle 56 when no force is applied to the pusher 55 in the pushing direction D, and the pusher 55 is prevented from moving. By applying force in the pushing direction D, the inner handle 57 can move relative to the outer handle 56 .

In FIG. 9 or 11, the spring 53 generally has a structure in which a metal wire is spirally wound, but other elastic bodies such as rubber may be used. The position of the pusher 52 or 55 relative to the outer handle 51 or 56 can be any position on the outer handle 51 or 56 within the range where the pusher 52 or 55 can push the inner handle 4 or 57 .

As described above, the present disclosure includes the following matters.

A lancing instrument (100) according to one aspect of the present disclosure includes a hollow shaft (1) having a lumen (11), a portion of the hollow shaft disposed in the lumen of the hollow shaft, and a distal end of the hollow shaft. A knife wire (5) fixed at the distal end of the outer handle (3) connected to the proximal end of the hollow shaft and formed with a through hole (31) opening at the distal and proximal ends and communicating with the lumen. and an inner handle (4) arranged in the through-hole from the proximal side and connected to the proximal end of the knife wire, and the outer handle has a contact portion capable of contacting the inner handle. (33), the contact portion of the lock mechanism contacts the inner handle to restrict the relative movement of the inner handle with respect to the outer handle, and the contact portion of the lock mechanism prevents contact with the inner handle. The release allows the inner handle to move relative to the outer handle.

According to the above configuration, by bringing the contact portion of the lock mechanism into contact with the inner handle, relative movement of the inner handle with respect to the outer handle is restricted. Therefore, when the inner handle is moved, it is not necessary to bring the outer handle and the inner handle into contact with each other, so that the movement can be facilitated and wear of the lock mechanism can be suppressed.

Further, the lock mechanism has a structure in which the inner diameter of the through-hole is variable, the through-hole of the outer handle has an inner peripheral portion, the inner handle has an outer peripheral portion, and the through-hole is in the natural state. The inner diameter has a predetermined size, the inner circumference of the outer handle is released from contact with the outer circumference of the inner handle, and the inner diameter of the through hole is relatively small compared to the natural state. The inner peripheral portion of the outer handle contacts the outer peripheral portion of the inner handle. In this case, since the inner peripheral portion of the through-hole of the outer handle can be used as the contact portion, it is possible to simplify the lock mechanism.

The lock mechanism also includes a slit (33) formed in the outer handle, communicated with the through-hole, and provided along the extending direction of the through-hole. In this case, the inner peripheral surface of the through hole of the outer handle can be easily brought into contact with the inner handle.

The outer handle has a recess (32) circumferentially formed on its inner peripheral surface, and the inner handle has a protruding portion (45) circumferentially formed on its outer peripheral surface. In this case, when the inner handle rotates with respect to the outer handle, it is possible to restrict the movement of the inner handle along the extending direction of the through-hole.

Also, a plurality of recesses are formed along the longitudinal direction of the through hole. In this case, while allowing the inner handle to move stepwise in the longitudinal direction of the through hole, it is possible to limit the movement of the inner handle along the longitudinal direction of the through hole when the inner handle rotates.

Further, the lock mechanism is arranged to penetrate from the outer peripheral portion to the inner peripheral portion of the outer handle, and has an outer peripheral end (52a) located on the outer peripheral side of the outer handle and an inner peripheral end (52a) located on the inner peripheral side of the outer handle. When the outer peripheral end of the presser body is pressed, the inner peripheral end of the presser body is brought into contact with the inner handle, and the outer peripheral end of the presser body is pressed. By releasing, the inner peripheral end of the pusher is released from contact with the inner handle. In this case, since it is possible to restrict the movement of the inner handle relative to the outer handle by pressing the pressing body, it is possible to easily restrict the movement of the inner handle relative to the outer handle. .

The lock mechanism has an elastic body between the outer peripheral end of the pusher and the outer handle. When the outer peripheral end of the pusher is pushed down, the elastic body is compressed and the inner peripheral end is brought into contact with the inner handle. By releasing the depression of the outer peripheral end of the pressing body, the elastic body is elongated, and the contact of the inner peripheral end with the inner handle is released. In this case, it is possible to easily release the contact with the inner handle.

The lock mechanism is arranged so as to penetrate from the outer periphery to the inner periphery of each of the outer handle and the inner handle, and has an outer periphery located on the outer periphery side of the outer handle and an inner periphery located on the inner periphery side of the inner handle. When the outer peripheral end of the pressing body is pressed, the inner peripheral end of the pressing body is released from contact with the inner peripheral portion of the inner handle, and the outer peripheral end of the pressing body is pressed. is released, the inner peripheral end of the pusher comes into contact with the inner peripheral portion of the inner handle. In this case, it is possible to restrict the relative movement of the inner handle with respect to the outer handle by releasing the depression of the pressing body, so it is possible to easily restrict the relative movement of the inner handle with respect to the outer handle. become.

The lock mechanism has an elastic body between the outer peripheral end of the pusher and the outer handle, and when the outer peripheral end of the pusher is pushed down, the elastic body is compressed and the inner peripheral end is the inner peripheral portion of the inner handle. When the contact with is released and the pressing of the outer peripheral end of the pressing body is released, the elastic body is elongated and the inner peripheral end is brought into contact with the inner peripheral portion of the inner handle. In this case, it is possible to easily release the contact with the inner handle.

The above-described embodiments of the present disclosure are illustrative examples of the present disclosure, and are not intended to limit the scope of the present disclosure only to those embodiments. Those skilled in the art can implement the invention in various other forms without departing from the scope of the invention.

1: hollow shaft, 2: connector, 3: outer handle, 4: inner handle, 5: knife wire, 11: lumen, 12: slit, 21: main body, 22: through hole, 23: branch, 24: hole 31: through hole 31a: first through hole 31b: second through hole 32: concave portion 33: slit 33: concave portion 41: insertion portion 42: grip portion 43: hole portion 44 : Fixed terminal 45: Convex part 51: Outer handle 52: Pressing body 52a: Outer peripheral end 52b: Inner peripheral end 53: Spring 55: Pressing body 55a: Outer peripheral end 55b: Inner peripheral end 56: Outer handle, 57: Inner handle

Claims (9)

a hollow shaft having a lumen;
a knife wire disposed in the lumen of the hollow shaft, partially exposed from the hollow shaft, and having a tip fixed at the tip of the hollow shaft;
an outer handle connected to the proximal end of the hollow shaft and formed with through-holes that open at the distal end and the proximal end and communicate with the lumen;
an inner handle arranged in the through hole from the proximal side and connected to the proximal end of the knife wire;
The outer handle has a lock mechanism having a contact portion capable of coming into contact with the inner handle,
Relative movement of the inner handle with respect to the outer handle is restricted by the abutment of the abutment portion of the lock mechanism against the inner handle, and the abutment portion of the lock mechanism prevents abutment with the inner handle. A lancing instrument, wherein release allows the inner handle to move relative to the outer handle. The lock mechanism has a structure in which the inner diameter of the through hole is variable,
the through hole of the outer handle has an inner circumference,
The inner handle has an outer peripheral portion,
In a natural state, the inner diameter of the through hole has a predetermined size, and the inner peripheral portion of the outer handle is released from contact with the outer peripheral portion of the inner handle,
The incision instrument according to claim 1, wherein the inner peripheral portion of the outer handle abuts the outer peripheral portion of the inner handle when the inner diameter of the through hole is relatively small compared to the natural state. 3. The incision instrument according to claim 2, wherein the locking mechanism includes, as the structure, a slit formed in the outer handle, communicating with the through hole, and provided along the extending direction of the through hole. The outer handle has a concave portion formed along the circumferential direction on an inner peripheral surface forming the through hole,
4. The incision instrument according to claim 2, wherein said inner handle has a convex portion formed along the circumferential direction on its outer peripheral surface. 5. The incision instrument according to claim 4, wherein a plurality of said recesses are formed along the longitudinal direction of said through hole. The lock mechanism is arranged to penetrate from the outer peripheral portion to the inner peripheral portion of the outer handle, and has an outer peripheral end located on the outer peripheral side of the outer handle and an inner peripheral end located on the inner peripheral side of the outer handle. a presser body having a peripheral edge;
By pressing the outer peripheral end of the pressing body, the inner peripheral end of the pressing body is brought into contact with the inner handle,
2. The incision instrument according to claim 1, wherein when the outer peripheral end of the pressing body is released from being pressed, the inner peripheral end of the pressing body is released from contact with the inner handle. The locking mechanism has an elastic body between the outer peripheral edge of the pressing body and the outer handle,
By pressing the outer peripheral end of the pressing body, the elastic body is compressed, and the inner peripheral end is brought into contact with the inner handle,
7. The incision instrument according to claim 6, wherein the elastic body is elongated by releasing the pressing of the outer peripheral end of the pressing body, and the contact of the inner peripheral end with the inner handle is released. The lock mechanism is disposed so as to penetrate from the outer periphery to the inner periphery of each of the outer handle and the inner handle, and has an outer peripheral end located on the outer peripheral side of the outer handle and an inner peripheral side of the inner handle. a pusher having an inner peripheral end located at
By pressing the outer peripheral end of the pressing body, the inner peripheral end of the pressing body is released from contact with the inner peripheral portion of the inner handle,
2. The incision instrument according to claim 1, wherein the inner peripheral end of the pusher comes into contact with the inner peripheral portion of the inner handle by releasing the pressing of the outer peripheral end of the pusher. The locking mechanism has an elastic body between the outer peripheral edge of the pressing body and the outer handle,
By pressing the outer peripheral end of the pressing body, the elastic body is compressed, and the inner peripheral end is released from contact with the inner peripheral portion of the inner handle,
9. The incision instrument according to claim 8, wherein the elastic body is extended by releasing the pressing of the outer peripheral end of the pressing body, and the inner peripheral end is brought into contact with the inner peripheral portion of the inner handle. .

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