Patent ID: 12251080

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereafter, endoscopes according to preferred embodiments of the present invention will be described with reference to the drawings.

First Embodiment

FIG.1illustrates the configuration of an endoscope system12including an endoscope10according to an embodiment of the present invention. The endoscope system12includes the endoscope10, a processor device14, a light source device16, and a display18.

The endoscope10includes: an operation section22in which an elevating operation lever20, which is an operation member, is provided; and an insertion section24, which is provided on the distal end side of the operation section22and which is to be inserted into a subject.

The insertion section24has a longitudinal-axis direction Ax extending from the proximal end toward the distal end; and includes a flexible portion26, a bending portion28, and a distal end portion30, sequentially from the proximal end toward the distal end. First, schematic configuration of the distal end portion30will be described, and then detailed configuration of the distal end portion30will be described.

FIG.2is an enlarged perspective view of the distal end portion30. Here, the endoscope10according to the embodiment (seeFIG.1) is, for example, a side-viewing endoscope used as a duodenum scope, and the distal end portion30ofFIG.2has the configuration of a side-viewing endoscope.

FIG.3is a perspective view of a distal-end-portion body32of the distal end portion30.FIG.4is a perspective view of a cap34of the distal end portion30. As illustrated inFIG.2, the distal end portion30has the distal-end-portion body32and the cap34. The cap34is removably attached to the distal-end-portion body32. The distal-end-portion body32is provided on the distal end side of the insertion section24(seeFIG.1). In the distal-end-portion body32, an elevator36, which has a treatment-tool guiding surface36A described below, is provided.FIGS.2and4illustrate a state in which the elevator36is located in a lowered position.

FIG.2also illustrates various elements that are placed inside the insertion section24of the endoscope10(seeFIG.1). To be specific, provided are the following: the elevator36for performing, on a distal end portion of a treatment tool (not shown), an operation of changing the lead-out direction of the distal end portion of the treatment tool that is led out from the distal-end-portion body32; an elevating operation wire40(hereafter, referred to as “wire40”); and an air/water supply tube42. The wire40is directly coupled to the elevator36. Although not illustrated inFIG.2, the following contents are also provided: a treatment tool channel38leading to the distal-end-portion body32(seeFIG.6); an angle wire for performing an operation of changing the bending direction of the bending portion28(seeFIG.1); a signal cable for transmitting an image signal; a light guide for transmitting illumination light; and the like.

In the present specification, a three-dimensional orthogonal coordinate system having a triaxial direction (X-axis direction, Y-axis direction, Z-axis direction) will be used for description. That is, as seen from the operation section22toward the distal end portion30, when the direction in which the treatment tool (not shown) is led out by the elevator36is defined as the upward direction, the upward direction is defined as the Z(+) direction, and the downward direction, which is opposite to the upward direction, is defined as the Z(−) direction. The rightward direction at this time is defined as the X(+) direction, and the leftward direction is defined as the X(−) direction. The forward direction at this time (direction toward the distal end side in the longitudinal-axis direction Ax of the insertion section24) is defined as the Y(+) direction, and the backward direction (direction toward the proximal end side in the longitudinal-axis direction Ax of the insertion section24) is defined as the Y(−) direction. The Y-axis direction, including the Y(+) direction and the Y(−) direction, is parallel to the longitudinal-axis direction Ax of the insertion section24. The Z-axis direction is a direction perpendicular to the longitudinal-axis direction Ax. The X-axis direction is a direction perpendicular to the Z-axis direction.

Referring back toFIG.1, the operation section22as a whole has a substantially cylindrical shape. The operation section22includes an operation section body46on which the elevating operation lever20is rotatably provided, and a grip portion48that is continuously connected to the operation section body46. A proximal end portion of the insertion section24is provided on the distal end side of the grip portion48via a breakage preventing tube50. The grip portion48is a portion to be gripped by an operator when the operator operates the endoscope10.

The operation section body46is equipped with a universal cable52. A light source connector54is provided on the distal end side of the universal cable52. An electric connector56branches from the light source connector54. The electric connector56is connected to the processor device14, and the light source connector54is connected to the light source device16.

On the operation section body46, an air/water supply button57and a suction button59are arranged side by side. When the air/water supply button57is operated, air and water are supplied to the air/water supply tube42ofFIG.2, and the air and water can be ejected from an air/water supply nozzle58provided in the distal-end-portion body32. The air/water supply button57ofFIG.1is operated in two steps. With an operation in the first step, air is supplied to the air/water supply tube42. With an operation in the second step, water is supplied to the air/water supply tube42.

When the suction button59ofFIG.1is operated, a bodily fluid such as blood can be sucked from a suction opening, which also serves as a treatment-tool lead-out port60provided in the distal-end-portion body32ofFIG.2, through the treatment tool channel38(seeFIG.6).

As illustrated inFIG.1, a pair of angle knobs62, which are used to for the operation of bending the bending portion28, is disposed on the operation section body46. The pair of angle knobs62are coaxially rotatable.

The elevating operation lever20is rotatable coaxially with the angle knobs62. The elevating operation lever20is rotated by a hand of an operator who grips the grip portion48. When the elevating operation lever20is rotated, the wire40ofFIG.2is pushed or pulled in synchronism with the rotational operation of the elevating operation lever20. Due to such an operation on the wire40, the posture of the elevator36, which is coupled to the distal end side of the wire40, is changed between the lowered position illustrated inFIG.2and the elevated position (not shown).

As illustrated inFIG.1, the grip portion48of the operation section22includes a treatment-tool insertion port64for inserting a treatment tool. A treatment tool (not shown), which is inserted from the treatment-tool insertion port64with the distal end portion thereof being a leading end portion, is inserted into the treatment tool channel38(not shown), and is led to the outside from the treatment-tool lead-out port60provided in the distal-end-portion body32.

As illustrated inFIG.1, the flexible portion26of the insertion section24has a helical tube (not shown) that is formed by helically winding a thin metal strip having elasticity. The flexible portion26is formed by covering the outside of this helical tube with a tubular mesh member, which is made of a braided metal wire, and by covering the outer peripheral surface of the mesh member with an outer covering made of a resin.

The bending portion28of the insertion section24has a structure such that a plurality of angle rings (not shown) are unrotatably coupled to each other. The bending portion28is formed by covering the outer periphery of this structure with a tubular mesh member made of a braided metal wire, and by covering the outer peripheral surface of the mesh member with a tubular outer covering made of rubber. For example, four angle wires (not shown) are placed from the bending portion28, which is configured in this way, to the angle knobs62. When the angle knobs62are rotated, these angle wires are pushed or pulled, and thereby the bending portion28is bent in the up-down direction and in the left-right direction.

The endoscope10according to the embodiment is, for example, a side-viewing endoscope that is used as a duodenum scope, and the insertion section24is inserted into a subject through the oral cavity. The insertion section24is inserted from the esophagus to the duodenum through the stomach, and a predetermined operation such as a predetermined test or treatment is performed.

Examples of a treatment tool used with the endoscope10according to the embodiment include: biopsy forceps having a cup, which can obtain living tissue, at a distal end portion; an endoscopic sphincterotomy (EST) knife; and an imaging cannula.

Next, referring toFIGS.2,3, and4, the structure of the distal end portion30will be described.

As illustrated inFIG.2, the distal end portion30includes the distal-end-portion body32and the cap34that is removably attached to the distal-end-portion body32. As illustrated inFIG.3, the distal-end-portion body32has a partition wall68that protrudes in the Y(+) direction. When the cap34is attached to the distal-end-portion body32, an elevator housing space66is formed by the partition wall68of the distal-end-portion body32and wall portions34B of the cap34. The elevator housing space66is disposed at a position in the X(+) direction of the partition wall68and in the Y(+) direction of the treatment-tool lead-out port60. The distal-end-portion body32is made of an anticorrosive metal material.

As illustrated inFIGS.2and3, in an upper surface68A on the Z(+) side of the partition wall68, an illumination window74and an observation window76are placed adjacent to each other in the Y direction. The observation window76enables observation of a field of view in the Z(+) direction.

The air/water supply nozzle58is provided on the distal-end-portion body32toward the observation window76. The observation window76is cleaned with air and water ejected from the air/water supply nozzle58.

As illustrated inFIG.3, the partition wall68includes an optical-system housing chamber72inside thereof. The optical-system housing chamber72houses an illumination unit (not shown) and an imaging unit (not shown). The illumination unit includes an illumination lens (not shown), which is disposed on the optical-system housing chamber72side of the illumination window74, and a light guide (not shown), which is disposed so that a distal end surface thereof faces the illumination lens. The light guide is placed into the universal cable52from the insertion section24of the endoscope10(seeFIG.1) through the operation section22. A proximal end of the light guide is connected to the light source connector54. When the light source connector54is connected to the light source device16, irradiation light from the light source device16is transmitted to the illumination lens through the light guide. A field of view in the Z(+) direction is irradiated with irradiation light from the illumination window74.

The imaging unit includes an imaging optical system (not shown), which is placed inside the observation window76, and an image pick-up element (not shown) of a complementary metal oxide semiconductor (CMOS) type or a charge coupled device (CCD) type. A distal end of a signal cable (not shown) is connected to the image pick-up element. The signal cable is placed into the universal cable52from the insertion section24of the endoscope10(seeFIG.1) through the operation section22. A proximal end of the signal cable is connected to the electric connector56. When the electric connector56is connected to the processor device14, an image pick-up signal of a subject image obtained by the imaging unit is transmitted to the processor device14through the signal cable. The image pick-up signal is image-processed by the processor device14and then displayed on the display18as a subject image.

The distal-end-portion body32has a stopper portion63on the proximal end side thereof. The stopper portion63engages with a stopper-target portion (described below) that is provided on a surface of a contact member37on the proximal end side. In the distal-end-portion body32, a through-hole61, for inserting the wire40(not shown) therethrough, is formed.

As illustrated inFIG.4, the cap34includes the wall portion34B that has a substantially tubular shape whose distal end side is sealed. In a part of the outer peripheral surface of the cap34, an open window34A having a substantially rectangular shape is defined by the wall portion34B. A bearing34D, which extends in the Y(+) direction (direction extending in the longitudinal-axis direction Ax), is formed inside the cap34. The bearing34D has a plate-like shape having a height in the Z(+) direction. The cap34is made of an elastic material that is, for example, a rubber material, such as fluorocarbon rubber or silicone rubber, or a resin material, such as polysulfone or polycarbonate.

A rotation shaft36B of the elevator36is supported in a through-hole (not shown) of the bearing34D. The rotation shaft36B is a rod-shaped member having a length in the X-axis direction perpendicular to the bearing34D. The elevator36is rotatable between a lowered position and an elevated position around the rotation shaft36B.

The wire40is coupled to the elevator36. The wire40is attached to a position that is adjacent to the treatment-tool guiding surface36A and that is on a side opposite to a side on which the rotation shaft36B is formed on the distal end side of the elevator36.

In the present embodiment, the elevator36is attached to the cap34illustrated inFIG.4, and the cap34with the elevator36is used as a single component as a whole. The wire40is coupled to the elevator36.

The open window34A of the cap34opens in the Z(+) direction. That is, the opening direction of the open window34A of the cap34is a direction that is perpendicular to the longitudinal-axis direction Ax of the insertion section and that is perpendicular to the axial direction of the rotation shaft36B (X-axis direction).

The cap34is an integrally molded body in which the wall portion34B and the contact member37are integrally molded. The contact member37is made of a resin material. The contact member37is disposed on the proximal end side of the open window34A. The contact member37as a whole protrudes in the Y(+) direction. The phrase “integrally mold” means integrally molding a product (the cap34and the contact member37) at the same a time as joining of members, without using adhesives or mechanical joint.

The cap34, including the wire40and the elevator36, is removed from the distal-end-portion body32after a treatment using the endoscope10is finished, and, for example, is thrown away as a disposable item.

When the cap34is attached to the distal-end-portion body32, as illustrated inFIG.2, the cap34forms the elevator housing space66, and the open window34A opens in the Z(+) direction. The treatment-tool lead-out port60of the distal-end-portion body32communicates with the open window34A through the elevator housing space66. The contact member37is positioned in the Z(+) direction with respect to the treatment-tool lead-out port60, and the contact member37is provided at a position facing the treatment-tool guiding surface36A when the elevator36is in the elevated position.

The distal end portion30includes a removal-preventing mechanism for preventing the cap34from becoming removed from the distal-end-portion body32in the Y(+) direction. The removal-preventing mechanism includes: in the cap34, a cap-side latch portion34C (seeFIGS.2and4) that is provided in one of the two wall portions34B, which are located with the open window34A therebetween; and, in the distal-end-portion body32, a body-side latch portion78(seeFIG.3) that is provided at a position facing the cap-side latch portion34C.

As illustrated inFIGS.2and4, the cap-side latch portion34C is formed by cutting out the cap34in a U-shape. The U-shaped cutout extends through the outside and the inside of the cap34. The U-shaped cutout has a U-shape that opens in the Y(−) direction, and the cap-side latch portion34C is in a state, which is a so-called cantilever state, in which a side of the cap-side latch portion34C on the proximal end side is coupled to the cap34. The distal end side of the cap-side latch portion34C is displaceable in the X(+) direction and the X(−) direction with a coupling position with the cap34as a fulcrum. As illustrated inFIG.3, the body-side latch portion78is a protrusion that is formed on the distal-end-portion body32and that protrudes in the X(−) direction.

FIG.5is a sectional view including the cap-side latch portion34C illustrated inFIG.2. The cap34and the distal-end-portion body32are attached to or removed from each other by being moved relative to each other in the Y-axis direction. The body-side latch portion78has a substantially trapezoidal shape in the sectional view. The body-side latch portion78has, on the distal end side thereof, an inclined surface that spreads outward from the distal end side toward the proximal end side of the distal-end-portion body32. On the other hand, the body-side latch portion78has, on the proximal end side thereof, a perpendicular surface that is perpendicular to the Y-axis direction. The cap-side latch portion34C has, on the distal end side thereof, an inwardly bent shape, and the distal end of the cap-side latch portion34C is formed of a perpendicular surface that is perpendicular to the Y-axis direction.

A case of attaching the cap34to the distal-end-portion body32will be described. In the following description, for ease of understanding, it is assumed that the distal-end-portion body32is in a state of being fixed.

When the cap34is being attached to the distal-end-portion body32, the cap34is moved in the direction from Y(+) to Y(−). The bent portion of the cap-side latch portion34C comes into contact with the inclined surface of the body-side latch portion78. When the cap34is moved further in the Y(−) direction, the cap-side latch portion34C moves along the inclined surface of the body-side latch portion78, and, finally, moves over the body-side latch portion78.

The distal end of the cap-side latch portion34C and the proximal end of the body-side latch portion78each have a perpendicular surface. When the cap34moves in the Y(+) direction, a large resistance force is generated as the cap-side latch portion34C moves over the body-side latch portion78. Removal of the cap34from the distal-end-portion body32is suppressed.

Next, referring toFIGS.6to9, an endoscope including the cap34, which can suppress deformation due to a load and which is easily removable from the distal-end-portion body32, will be described.FIG.6is a perspective view of the distal end portion30as seen from the X(+) side, andFIG.7is a perspective assembly view of the distal end portion30.FIG.8is a partial enlarged perspective view of the distal end portion30.FIG.9illustrates operations of attaching and removing the cap. InFIG.7, the wire40is not illustrated.

As illustrated inFIGS.6and7, the cap34has a cantilever piece90that is provided on one of the two wall portions34B, which are disposed in the X(+) direction and the X(−) direction with the open window34A therebetween. The cantilever piece90is formed by providing a cutout91in the cap34. The cutout91extends through the outside and the inside of the cap34.

The cantilever piece90extends in the Y-axis direction and has a fixed end90A, which is coupled to the cap34, and a free end90B, which is not coupled to the cap34. The fixed end90A is positioned on the distal end side (in the Y(+) direction) relative to the free end90B. Because the free end90B is not coupled to the cap34, the free end90B is displaceable in the X(+) direction and the X(−) direction. The free end90B is movable. Because the cantilever piece90is formed by the cutout91of the cap34, the cantilever piece90is made of the same material as the cap34.

A stopper-target portion90C is provided at the free end90B of the cantilever piece90. The stopper-target portion90C has a width that is greater than the width of any other part of the cantilever piece90. When the stopper-target portion90C is seen from the X(+) direction, the cantilever piece90as a whole is T-shaped. The stopper-target portion90C is displaceable in the X(+) direction and the X(−) direction in conjunction with the free end90B.

The cantilever piece90has a pressing portion90D that is positioned between the fixed end90A and the free end90B and that is separated from the distal-end-portion body32. When a pressing force due to a human finger (not shown) is applied to the pressing portion90D, the pressing portion90D becomes elastically bent toward the X(−) side. The shape of the cantilever piece90is not limited to the T-shape, as long as the cantilever piece90can be bent by a pressing force due to a human finger. The shape of the cantilever piece90is determined in consideration of length, thickness, width, and the like. The length of the cantilever piece90is a distance in the Y-axis direction, the thickness of the cantilever piece90is the distance between the outer surface and the inner surface of the cantilever piece90, and the width of the cantilever piece9) is a distance in a direction perpendicular to the length and the thickness.

As illustrated inFIG.7, the distal-end-portion body32has two stopper portions80and a fulcrum portion82, which is positioned between the stopper portions80, on a side facing the cantilever piece90. The two stopper portions80define a groove portion84.

As illustrated inFIG.8, the two stopper portions80are disposed at positions such that the stopper portions80form the groove portion84that is narrower than the width of the stopper-target portion90C and that is wider than the width of any other part of the cantilever piece90(any part other than the stopper-target portion90C). The stopper portions80and the stopper-target portion90C are engaged due to the magnitude relationship among the distance between the stopper portions80, the width of the stopper-target portion90C, and the width of any part other than the stopper-target portion90C.

As long as the stopper portions80and the stopper-target portion90C are provided as a removal-preventing mechanism, the cap-side latch portion34C and the body-side latch portion78need not be provided.

Next, referring toFIG.9, attachment and removal of the cap34and the distal-end-portion body32will be described.9-1is a sectional view taken along line9-1ofFIG.8, and9-2is a sectional view taken along line9-2ofFIG.8.

In a state in which the cap34is attached to the distal-end-portion body32, the cantilever piece90is not bent as shown by a two-dot chain line in9-1. In the embodiment, the cantilever piece90is substantially in contact with the fulcrum portion82. The pressing portion90D of the cantilever piece90is separated from the distal-end-portion body32. The term “separated” means a state in which the pressing portion90D is not in contact with the distal-end-portion body32.

As illustrated in9-2, in the state in which the cap34is attached to the distal-end-portion body32, the stopper portion80and the stopper-target portion90C, which is shown by a two-dot chain line, engage with each other. As illustrated in9-2, the stopper portion80has an inclined surface80A. The inclined surface80A is an inclined surface that spreads outward from the distal end side toward the proximal end side of the distal-end-portion body32. The stopper portion80has, on the proximal end side thereof, a perpendicular surface80B that is perpendicular to the Y-axis direction.

As illustrated in9-1and9-2, the fulcrum portion82is disposed on the distal end side of the distal-end-portion body32(in the Y(+) direction) from the position of the perpendicular surface80B (engagement surface) of the stopper portion80. The fixed end90A of the cantilever piece90is disposed on the distal end side of the distal-end-portion body32relative to the position of the fulcrum portion82.

When the cap34is being attached to the distal-end-portion body32, the cap34is moved in the direction from Y(+) to Y(−). The stopper-target portion90C comesinto contact with the inclined surface80A of the stopper portion80. When the cap34is moved further in the Y(−) direction, the stopper-target portion90C moves along the inclined surface80A of the stopper portion80, and, finally, moves over the stopper portion80.

The stopper-target portion90C has, on the distal end side thereof, a perpendicular surface90E perpendicular to the Y-axis direction. The perpendicular surface80B of the stopper portion80and the perpendicular surface90E of the stopper-target portion90C face each other, and the stopper portion80and the stopper-target portion90C engage with each other. Thus, when the cap34moves in the Y(+) direction, a large resistance force is generated as the stopper-target portion90C moves over the stopper portions80. Removal of the cap34from the distal-end-portion body32is suppressed.

The term “engage” means a state in which, as seen from the Y(+) direction, the stopper portion80is positioned on the distal end side, the stopper-target portion90C is positioned on the proximal end side, and the stopper portion80and the stopper-target portion90C partially overlap. In the partially overlapping state, the perpendicular surfaces need not face each other.

Next, as illustrated in9-1, when a force in the X(−) direction is applied to the pressing portion90D by a finger F, the cantilever piece90, which is shown by a solid line, bends in the X(−) direction. Because the cantilever piece90is in contact with the fulcrum portion82, as illustrated in9-2, the stopper-target portion90C, which is provided at the free end90B, moves toward the X(+) side with the fulcrum portion82as a fulcrum due to “leverage”. Engagement between the stopper portion80and the stopper-target portion90C is released, and the stopper-target portion90C is removed from the stopper portion80. The cap34can be easily moved from the distal-end-portion body32in the Y(+) direction to be removed.

The cap34according to the embodiment has a structure that has the contact member37, which is integrally molded, and that supports the elevator36. Therefore, as illustrated in10-1ofFIG.10, when the elevator36elevates a treatment tool100, the contact member37receives a load in the direction A. As illustrated in10-2, when a guidewire102is being locked, the contact member37receives a load in the direction B. Therefore, the cap34becomes likely to deform.

Moreover, when the elevator36is lowered, the wall portion34B, which faces the open window34A of the cap34, also receives a load and becomes likely to deform. Accordingly, in the cap34, a part that receives a load needs to have high rigidity to restrict deformation.

In the cap34according to the embodiment, the cantilever piece90is provided in a part that is not likely to receive a load, that is, on a side of one of the wall portions34B, which face each other with the open window34A therebetween. The part that is not likely to receive a load may have a rigidity lower than that of a part that receives a load. Low rigidity allows the cantilever piece90to easily bend when pressed by a finger. The cap34according to the embodiment can be easily attached and removed while maintaining rigidity.

The cap34according to the first embodiment has a shape that can be easily molded. When the cantilever piece90according to the first embodiment is being formed, a die is inserted into a portion corresponding to the cutout91. Because the die is moved outward from the cap34, demolding of the die can be easily performed.

Second Embodiment

Referring to the drawings, an endoscope according to a second embodiment will be described. Elements that are the same as those of the first embodiment will be denoted by the same numerals, detailed descriptions of such elements will be omitted, and mainly the differences from the first embodiment will be described.

Next, referring toFIGS.11to13, an endoscope including the cap34, which can suppress deformation due to a load and which is easily removable from the distal-end-portion body32, will be described.FIG.11is a perspective view of the distal end portion30as seen from the X(+) side, andFIG.12is a perspective assembly view of the distal end portion30.FIG.13illustrates operations of attaching and removing the cap. InFIG.12, the wire40is not illustrated.

In the second embodiment, the shapes of a cantilever piece190, a stopper portion180, and a fulcrum portion182differ from those of the first embodiment. As illustrated inFIGS.11and12, the cap34has the cantilever piece190. The cantilever piece190is provided on one of two wall portions34B, which are disposed in the X(+) direction and the X(−) direction, with the open window34A therebetween. The cantilever piece190is formed by providing a cutout191in the cap34. The cutout191extends through the outside and the inside of the cap34.

The cantilever piece190extends in the Y-axis direction and has a fixed end190A, which is coupled to the cap34, and a free end190B, which is not coupled to the cap34. The fixed end190A is positioned on the proximal end side (in the Y(−) direction) relative to the free end190B. The cantilever piece190is made of the same material as the cap34. Because the free end190B is not coupled to the cap34, the free end190B is displaceable in the X(+) direction and the X(−) direction.

A stopper-target portion190C is provided at the free end190B of the cantilever piece190. The stopper-target portion190C engages with the stopper portion180.

The cantilever piece190has a pressing portion190D that is positioned between the fixed end190A and the free end190B and that is separated from the distal-end-portion body32. When a pressing force due to a human finger (not shown) is applied to the pressing portion190D, the pressing portion190D becomes elastically bent toward the X(−) side.

As illustrated inFIG.12, the distal-end-portion body32has the stopper portion180and a fulcrum portion182on a side facing the cantilever piece190. The stopper portion180and the fulcrum portion182are arranged in the Y-axis direction. The stopper portion180is positioned on the distal end side (in the Y(+) direction) relative to the fulcrum portion182.

Next, referring toFIG.13, attachment and removal of the cap34and the distal-end-portion body32will be described.FIG.13is a sectional view taken along line13-13ofFIG.11.

In a state in which the cap34is attached to the distal-end-portion body32, the cantilever piece190is not bent as illustrated in13-1. In the embodiment, the cantilever piece190is substantially in contact with the fulcrum portion182. The pressing portion190D of the cantilever piece190is separated from the distal-end-portion body32. The term “separated” means a state in which the pressing portion190D is not in contact with the distal-end-portion body32in an attached state.

As illustrated in13-1, in the state in which the cap34is attached to the distal-end-portion body32, the stopper portion180and the stopper-target portion190C engage with each other. The stopper portion180has an inclined surface180A that tapers toward the distal end side of the distal-end-portion body32. The stopper portion180has, on the proximal end side thereof (the Y(−) direction), a perpendicular surface180B that is perpendicular to the Y-axis direction.

As illustrated inFIG.13, the fulcrum portion182is disposed on the distal end side of the distal-end-portion body32from the position of the perpendicular surface180B (engagement surface) of the stopper portion180. The fixed end190A of the cantilever piece190is disposed on the proximal end side of the distal-end-portion body32relative to the position of the fulcrum portion182.

When the cap34is being attached to the distal-end-portion body32, the cap34is moved in the direction from Y(+) to Y(−). The stopper-target portion190C comesinto contact with the inclined surface180A of the stopper portion180. When the cap34is moved further in the Y(−) direction, the stopper-target portion190C moves along the inclined surface180A of the stopper portion180, and, finally, moves over the stopper portion180.

The stopper-target portion190C has, on the distal end side thereof, a perpendicular surface190E perpendicular to the Y-axis direction. The perpendicular surface180B of the stopper portion180and the perpendicular surface190E of the stopper-target portion190C face each other, and the stopper portion180and the stopper-target portion190C engage with each other. Thus, when the cap34moves in the Y(+) direction, a large resistance force is generated as the stopper-target portion190C moves over the stopper portion180. Removal of the cap34from the distal-end-portion body32is suppressed.

The term “engage” means a state in which, as seen from the Y(+) direction, the stopper portion180is positioned on the distal end side, the stopper-target portion190C is positioned on the proximal end side, and the stopper portion180and the stopper-target portion190C partially overlap. In the partially overlapping state, the perpendicular surfaces need not face each other.

Next, as illustrated in13-2, when a force in the X(−) direction is applied to the pressing portion190D by a finger F, the cantilever piece190bends in the X(−) direction. Because the cantilever piece190is in contact with the fulcrum portion182, as illustrated in13-2, the stopper-target portion190C, which is provided at the free end190B, moves toward the X(+) side with the fulcrum portion182as a fulcrum due to “leverage”. Engagement between the stopper portion180and the stopper-target portion190C is released, and the stopper-target portion190C is removed from the stopper portion180. The cap34can be easily moved from the distal-end-portion body32in the Y(+) direction to be removed.

Third Embodiment

Referring to the drawings, an endoscope according to a third embodiment will be described. Elements that are the same as those of the first embodiment will be denoted by the same numerals, detailed descriptions of such elements will be omitted, and mainly the differences from the first embodiment will be described.

The third embodiment differs from the first embodiment in the structure of the cap34and in the method of disengaging the stopper-target portion90C and the stopper portions80.

FIG.14is a side view of the third embodiment as seen from the X(+) side.FIG.15is a sectional view taken along line15-15ofFIG.14. As illustrated inFIG.14, the cap34includes the cantilever piece90formed by the cutout91. The cantilever piece90includes the fixed end90A, the free end90B, and the stopper-target portion90C provided at the free end90B. The distal-end-portion body32includes the stopper portions80. When the cap34is attached to the distal-end-portion body32, the stopper portions80and the stopper-target portion90C engage with each other.

Two notches92are formed in the cap34. One notch92extends from a side of the cutout91in the Z(+) direction, and the other notch92extends from a side of the open window34A in the Z(−) direction. The notches92extend through the outside and the inside of the cap34. The Y(+) side and the Y(−) side of the cap34are not coupled across the notches92. In the embodiment, one notch92has a shape (here, referred to as a triangular shape) that tapers in the Z(+) direction in a part thereof that is continuous with the cutout91. The other notch92has a shape (here, referred to as an inverted triangular shape) that tapers in the Z(−) direction. The two notches92are in a positional relationship perpendicular to the cantilever piece90. Here, “perpendicular” includes “completely perpendicular” and “substantially perpendicular”. Here, “perpendicular” includes a case where the angle (smaller angle) between the cantilever piece90and the notches92is 80° or greater. The shapes of the notches92are not limited to the shapes illustrated inFIG.14. In the embodiment, the cap34is not separated between the apex of the notch92having a triangular shape and the apex of the notch92having an inverted triangular shape. An additional notch may be formed between the vertices. The additional notch may be a continuous notch or a perforated tear-off notch. The notches92facilitate braking of the cap34. In the embodiment, two notches92are shown. However, there may be only one notch92. It is possible to break the cap34, provided that there is a notch92that extends in the Z(−) direction from the side of the open window34A.

The cap34has a small-thickness portion93that is parallel to the cantilever piece90. The small-thickness portion93extends in the Y(+) direction from a position near the fixed end90A of the cantilever piece90. The small-thickness portion93does not reach a distal end portion of the cap34.

As illustrated inFIG.15, the small-thickness portion93has a groove portion formed inside the cap34, and has a shape having a smaller thickness than the other portions. The term “parallel” includes “completely parallel” and “substantially parallel”.

As illustrated inFIG.14, the cap34includes a cutout94that has a linear shape and that extends from the small-thickness portion93in the Y(+) direction. The cutout94extends through the outside and inside of the cap34. The Z(+) side and the Z(−) side of the cap34are not coupled across the cutout94.

Next, a method of disengaging the stopper portions80and the stopper-target portion90C will be described. As illustrated inFIG.14, because the cap34has the notches92and the small-thickness portion93, the rigidity of the cap34is reduced.

It is possible to break the cap34with the small-thickness portion93as a fulcrum by applying a force in the direction of an arrow (the X(+) direction) to the cap34as illustrated inFIG.15, at a position in the Y(+) direction from the notch92and in the Z(+) direction from the small-thickness portion93(seeFIG.14). Due to breakage of the cap34, the stopper portions80and the stopper-target portion90C are disengaged, and the cap34is removed from the distal-end-portion body32. It becomes easy to break the cap34by providing the linear cutout94. The linear cutout94need not be provided. As long as the stopper portions80and the stopper-target portion90C can be disengaged, breakage of the cap34may be deformation of the cap34, and it is not necessary to cut and separate the cap34into a plurality of pieces. The cap34that is not separated is treated as one component and can be easily discarded.

Heretofore, the present invention has been described. The present invention is not limited to the examples described above, and may be improved or modified within the spirit and scope of the present invention. The present invention is applicable to an endoscope including an elevator in a distal-end-portion body, an endoscope in which an elevator wire is coupled to a lever of a distal-end-portion body, and the like.

REFERENCE SIGNS LIST

10endoscope12endoscope system14processor device16light source device18display20elevating operation lever22operation section24insertion section26flexible portion28bending portion30distal end portion32distal-end-portion body34cap34A open window34B wall portion34C cap-side latch portion34D bearing36elevator36A treatment-tool guiding surface36B rotation shaft37contact member38treatment tool channel40elevating operation wire42air/water supply tube46operation section body48grip portion50breakage preventing tube52universal cable54light source connector56electric connector57air/water supply button58air/water supply nozzle59suction button60treatment-tool lead-out port61through-hole62angle knob63stopper portion64treatment-tool insertion port66elevator housing space68partition wall68A upper surface72optical-system housing chamber74illumination window76observation window78body-side latch portion80stopper portion80A inclined surface80B perpendicular surface82fulcrum portion84groove portion90cantilever piece90A fixed end90B free end90C stopper-target portion90D pressing portion90E perpendicular surface91cutout93small-thickness portion94cutout100treatment tool102guidewire180stopper portion180A inclined surface180B perpendicular surface182fulcrum portion190cantilever piece190A fixed end190B free end190C stopper-target portion190D pressing portion190E perpendicular surface191cutoutAx longitudinal-axis directionF finger