Patent Publication Number: US-11638515-B2

Title: Endoscope, rising base, cap for endoscope, method for attaching cap for endoscope, and method for detaching cap for endoscope

Description:
TECHNICAL FIELD 
     The present invention relates to an endoscope, an elevator, an endoscope cap, a mounting method of the endoscope cap, and a dismounting method of the endoscope cap. 
     BACKGROUND ART 
     An endoscope including an elevator at a distal tip of a channel passing through the inside of an insertion portion has been used. The elevator is used at the time of bending a treatment tool or the like that has passed through the channel and guiding the treatment tool in a desired direction. 
     An endoscope provided with a wall between an elevation wire that moves an elevator and the elevator is disclosed (Patent Literature 1). 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 8-56900 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the endoscope disclosed in Patent Literature 1, it takes time and effort for cleaning since a structure around the elevator is complicated. 
     In one aspect, an object of the invention is to provide an endoscope or the like that can be easily cleaned by dismounting an elevator after endoscopic examination. 
     Solution to Problem 
     An endoscope includes a lever that is rotatably provided at a distal tip of an insertion portion, an elevator that can be attached to and detached from the distal tip of the insertion portion, and includes a lever connection portion connected to the lever, and an elevator shaft arranged to rotate coaxially with the lever when the lever connection portion and the lever are connected, and an endoscope cap that can be attached to and detached from the distal tip of the insertion portion, and includes a bottomed cylindrical cover, an elevator support portion that is provided inside the cover and has an inlet through which the elevator shaft enters when mounted to the distal tip of the insertion portion, and an elevator pivot portion provided at the inlet. 
     Advantageous Effects of Invention 
     In one aspect, it is possible to provide an endoscope or the like that is easy to clean by dismounting an elevator after endoscopic examination. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is an exterior view of an endoscope. 
         FIG.  2    is a perspective view of a distal tip of an insertion portion. 
         FIG.  3    is an explanatory view illustrating a state where a treatment tool distal tip protrudes from the distal tip of the insertion portion. 
         FIG.  4    is a front view of the distal tip of the insertion portion. 
         FIG.  5    is a front view for describing a state where an endoscope cap and an elevator are dismounted from the distal tip of the insertion portion. 
         FIG.  6    is a back view for describing the state where the endoscope cap and the elevator are dismounted from the distal tip of the insertion portion. 
         FIG.  7    is a perspective view of the distal tip of the insertion portion with the endoscope cap and the elevator dismounted. 
         FIG.  8    is a perspective view of the distal tip of the insertion portion with the endoscope cap, the elevator, and a lever chamber lid dismounted. 
         FIG.  9    is a perspective view of the endoscope cap as viewed from an attachment side with respect to the endoscope. 
         FIG.  10    is a perspective view of the endoscope cap as viewed from a bottom side of a cover. 
         FIG.  11    is an enlarged perspective view of a first engagement portion. 
         FIG.  12    is a perspective view of the elevator. 
         FIG.  13    is a front view of the elevator. 
         FIG.  14    is a side view of the elevator. 
         FIG.  15    is a perspective view of a pedestal. 
         FIG.  16    is a cross-sectional view of the endoscope cap taken along line XVI-XVI of  FIG.  5   . 
         FIG.  17    is a perspective view of the lever. 
         FIG.  18    is a cross-sectional view of the distal tip of the insertion portion from which the endoscope cap is dismounted. 
         FIG.  19    is a cross-sectional view of the insertion portion taken along line XIX-XIX of  FIG.  4   . 
         FIG.  20    is a cross-sectional view of the insertion portion taken along line XX-XX of  FIG.  4   . 
         FIG.  21    is a cross-sectional view of the insertion portion taken along line XXI-XXI of  FIG.  20   . 
         FIG.  22    is a cross-sectional view of the insertion portion taken along line XXII-XXII of  FIG.  4   . 
         FIG.  23    is a cross-sectional view of the insertion portion with the elevator raised. 
         FIG.  24    is a perspective view of the pedestal according to a second embodiment. 
         FIG.  25    is a cross-sectional view of the insertion portion of the second embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       FIG.  1    is an exterior view of an endoscope. An endoscope  10  of this embodiment is a flexible scope for an upper gastrointestinal tract. The endoscope  10  includes an operation unit  20  and an insertion portion  30 . The operation unit  20  includes an elevation operation lever  21 , a channel inlet  22 , and a bending knob  23 . The operation unit  20  is connected to a video processor (not illustrated), a light source device, a display device, and the like. 
     The insertion portion  30  is long and has one end connected to the operation unit  20 . The insertion portion  30  includes a soft portion  12 , a bending section  13 , and an endoscope cap  50  in this order from the operation unit  20  side. The soft portion  12  is soft. The bending section  13  is bent according to an operation of the bending knob  23 . The endoscope cap  50  covers a hard distal tip  31  (see  FIG.  2   ) continuous with the bending section  13 . 
     In the following description, a longitudinal direction of the insertion portion  30  is referred to as an insertion direction. Similarly, a side close to the operation unit  20  along the insertion direction is referred to as an operation unit side, and a side far from the operation unit  20  is referred to as a distal tip side. 
       FIG.  2    is a perspective view of a distal tip of the insertion portion  30 .  FIG.  3    is an explanatory view illustrating a state where a treatment tool distal tip  41  protrudes from the distal tip of the insertion portion  30 . The configuration of the endoscope  10  according to this embodiment will be described with reference to  FIGS.  1  to  3   . 
     The distal tip  31  arranged at a distal tip of the bending section  13  has an observation window  36  and an illumination window  37  arrayed side by side on one side along the insertion direction. The illumination window  37  is arranged closer to the distal tip side than the observation window  36 . The distal tip  31  has a channel outlet  35  on the operation unit side on the other side. An elevation portion  83  is arranged on the distal tip side of the channel outlet  35 . The cover  52  covering the distal tip  31  has a substantially rectangular window portion  53  in a portion corresponding to the observation window  36 , the illumination window  37 , and the elevation portion  83 . The side of the window portion  53  on the operation unit side has a stepped shape in which the elevation portion  83  is located on the operation unit side and the observation window  36  is located on the distal tip side. 
     The illumination window  37  performs irradiation with illumination light emitted from a light source device (not illustrated). It is possible to optically observe a range illuminated by the illumination light through the observation window  36 . The endoscope  10  of this embodiment is of a so-called side-view type in which a viewing direction in which optical observation is possible intersects the insertion direction. The endoscope  10  may be of a front oblique-view type in which the viewing direction is slightly inclined toward the distal tip side or a rear oblique-view type in which the viewing direction is slightly inclined toward the operation unit side. 
     The channel inlet  22  and the channel outlet  35  are connected by a channel  34  passing through the inside of the soft portion  12  and the bending section  13 . As a treatment tool  40  is inserted from the channel inlet  22  from a side of the treatment tool distal tip  41 , the treatment tool distal tip  41  can protrude from the channel outlet  35 . 
     The treatment tool distal tip  41  protrudes while loosely curving on the elevation portion  83  as indicated by the solid line in  FIG.  3   . When the elevation operation lever  21  is operated as indicated by the arrow in  FIG.  1   , a lever  60  (see  FIG.  8   ) moves as will be described later, and an elevator  80  moves in conjunction with the lever  60 . As the elevator  80  moves, the treatment tool distal tip  41  on the elevator  80  is bent toward the operation unit  20  as indicated by the arrows and two-dot chain lines in  FIGS.  1  and  3   . The movement of the treatment tool distal tip  41  is captured by an image sensor or the like (not illustrated) through the observation window  36 , and is displayed on the display device (not illustrated). 
     The treatment tool  40  is a treatment tool such as a high-frequency knife, a forceps, and a contrast tube. Incidentally, the instrument to be inserted into the channel  34  is not limited to the instrument for treatment. For example, an instrument for observation such as an ultrasonic probe and a microscopic endoscope may be inserted into the channel  34  for use. In the following description, the instrument for observation is also referred to as the treatment tool  40 . 
     In the following description, the movement of the elevator  80  as described above may be expressed as “the elevator  80  rises”. In the following description, an operation in which the treatment tool distal tip  41  is pushed by the raised elevator  80  and is bent may be referred to as “the treatment tool  40  rises”. It is possible to adjust the degree of the rise of the treatment tool  40  by the operation of the elevation operation lever  21 . 
       FIG.  4    is a front view of the distal tip of the insertion portion  30 . The cover  52  has a rectangular concave portion  48  in the vicinity of an opening end portion  56 . Each side of the concave portion  48  falls substantially vertically from the surface of the cover  52 . The concave portion  48  is thinner than other portions of the cover  52  in the circumferential direction, and is a portion that is easily flexed when an external force is applied thereto by being pushed by a finger or the like. The concave portion  48  is an example of a flexible portion of this embodiment. 
     The endoscope cap  50  and the elevator  80  can be attached to and detached from the endoscope  10  according to this embodiment through the insertion portion  30 . The endoscope cap  50  has the cover  52  that is an exterior member. Detailed configurations of the endoscope cap  50  and the elevator  80  will be described later. 
       FIG.  5    is a front view for describing a state where the endoscope cap  50  and the elevator  80  are dismounted from the distal tip of the insertion portion  30 .  FIG.  6    is a back view illustrating a state where the endoscope cap  50  and the elevator  80  are dismounted from the distal tip of the insertion portion  30 . 
     A user holds the bending section  13  with one hand and picks the cover  52  with two fingers of the other hand. At this time, when one of the two fingers pushes the concave portion  48 , the other finger naturally pushes a region indicated by P in  FIG.  6   . The user can remove the endoscope cap  50  from the insertion portion  30  as will be described later by pressing the cover  52  with the two fingers to slightly deform the cover  52  and then pull the cover  52  to the distal tip side. At this time, the elevator  80  also comes off the insertion portion  30  together with the endoscope cap  50 . 
       FIG.  7    is a perspective view of the distal tip of the insertion portion  30  from which the endoscope cap  50  and the elevator  80  are dismounted. The configuration of the distal tip of the insertion portion  30  will be described with reference to  FIGS.  5  to  7   . The distal tip  31  has a substantially cylindrical shape and is divided into an optical housing portion  33  and a lever chamber  69  by a groove provided from the distal tip side toward the operation unit side at a position deviated from the center. The channel outlet  35  is open to a bottom of the groove. A curved portion  27  is provided in the vicinity of the channel outlet  35 . A shape of the curved portion  27  will be described later. 
     The distal tip  31  has a first flat surface portion  321  formed by cutting a part of a circumferential surface thereof into a flat shape. A third engagement portion  29  is provided on a portion of the first flat surface portion  321  along the bottom of the groove separating the optical housing portion  33  from the lever chamber  69 . The third engagement portion  29  is an oval recess. The distal tip  31  has a fourth engagement portion  28  (see  FIG.  6   ) on the back side of the third engagement portion  29 . The fourth engagement portion  28  is a rectangular recess. 
     The observation window  36  and the illumination window  37  are arranged on a side of the optical housing portion  33  of the first flat surface portion  321 . A nozzle  38  that sprays water and air to the observation window  36  to clean the observation window  36  is provided on the operation unit side of the observation window  36 . 
     The lever chamber  69  is hollow and is covered with a rectangular thin plate-shaped lever chamber lid  67  along an outer circumferential surface of the distal tip  31 . The lever chamber lid  67  is fixed at four corners using lid screws  66 . The lid screw  66  is an example of a fixing member of this embodiment. The lever chamber  69  has a support wall  68  on the optical housing portion  33  side. The elevator base connection portion  61  protrudes from the support wall  68  toward the optical housing portion  33 . The elevator base connection portion  61  is an axis having a rectangular cross section. The elevator base connection portion  61  will be described later. 
       FIG.  8    is a perspective view of the distal tip of the insertion portion  30  from which the endoscope cap  50 , the elevator  80 , and the lever chamber lid  67  are dismounted. The lever  60  is provided inside the lever chamber  69 . The lever  60  has a wire fixing portion  65  at one end and a lever shaft  63  (see  FIG.  17   ) and the elevator base connection portion  61  at the other end as will be described later. The lever  60  is rotatably supported by a hole provided in the support wall  68 . 
     The wire fixing portion  65  is connected to an end portion of an elevation wire  24 . The elevation wire  24  is connected to the elevation operation lever  21  (see  FIG.  1   ) through the insertion portion  30 . More specifically, the elevation wire  24  is inserted through a guide pipe (not illustrated) having an inner diameter slightly larger than an outer diameter of the elevation wire  24 . The guide pipe (not illustrated) passes through the insertion portion  30  in a longitudinal direction. Thus, a distal tip of the elevation wire  24  moves forward and backward in conjunction with the operation of the elevation operation lever  21 . 
     The lever  60  is rotated about the lever shaft  63  by being pushed and pulled by the distal tip of the elevation wire  24 . The elevation wire  24  is an example of a rotating portion of this embodiment. The elevation wire  24  is remotely operated by the elevation operation lever  21 . 
       FIG.  9    is a perspective view of the endoscope cap  50  as viewed from an attachment side with respect to the endoscope  10 .  FIG.  10    is a perspective view of the endoscope cap  50  as viewed from the bottom side of the cover  52 . The endoscope cap  50  has a cover  52  and a pedestal  70 . The cover  52  is of a bottomed tube type having an opening at one end. As described above, the opening at one end of the cover  52  is referred to as the opening end portion  56 . 
     As described above, the cover  52  has the window portion  53  in a tubular portion. The window portion  53  is open over substantially the entire length at one place on the circumferential surface of the cover  52 . The cover  52  has a pedestal groove  45  extending from the opening end portion  56  toward the bottom, on an inner surface facing the window portion  53 . The pedestal  70  is fixed to the pedestal groove  45 . The pedestal  70  will be described later. 
     The cover  52  has a plate-shaped protruding portion  49  that protrudes inward along an edge on the opening end portion  56  side of the window portion  53 . A first engagement portion  46  is provided on a part of the distal tip of the protruding portion  49  so as to protrude inward. 
       FIG.  11    is an enlarged perspective view of the first engagement portion  46 .  FIG.  11    is an enlarged view of part A in  FIG.  9   . A shape of the first engagement portion  46  will be described with reference to  FIGS.  9  to  11   . The first engagement portion  46  has a first wedge surface  461  on a bottom side and a second wedge surface  462  on the opening end portion  56  side. The first wedge surface  461  is a flat surface which is continuous with a surface of the protruding portion  49  on the bottom side and extends along an edge of the window portion  53 . 
     The second wedge surface  462  is a flat surface which is inclined with respect to an axial direction of the tubular portion having the inside on the bottom side and the outside on the opening end portion  56  side. When the first engagement portion  46  is cut by a surface parallel to the axis of the tubular portion, the first wedge surface  461  and the second wedge surface  462  are formed into a wedge shape. 
       FIG.  12    is a perspective view of the elevator  80 .  FIG.  13    is a front view of the elevator  80 .  FIG.  14    is a side view of the elevator  80 . The configuration of the elevator  80  will be described with reference to  FIGS.  12  to  14   . 
     The elevator  80  has a substantially L-shaped elevation portion  83 . The elevation portion  83  has a first elevation portion  831  having a spoon-shaped recessed portion  84  on one surface thereof and a second elevation portion  832  protruding to the same side as a surface having the recessed portion  84  of the first elevation portion  831  from an end of the first elevation portion  831 . 
     A lever connection portion  81  is provided at an end portion of the second elevation portion  832 . The lever connection portion  81  is a U-shaped groove which is open toward the end portion of the second elevation portion  832 . One side of the lever connection portion  81  is covered with a plate-shaped flange  85 . An elevator shaft  82  protrudes from a surface opposite to the flange  85 . 
     That is, the elevator shaft  82  protrudes from one surface of the flange  85 , and the elevation portion  83  protrudes from the other surface of the flange  85  in a direction intersecting the central axis of the elevator shaft  82 . The lever connection portion  81  is provided on a proximal end portion side of the elevation portion  83 . 
     The lever connection portion  81  is arranged so as to sandwich the central axis of the elevator shaft  82  as indicated by the broken line in  FIG.  14   . 
       FIG.  15    is a perspective view of the pedestal  70 . A configuration of the pedestal  70  will be described with reference to  FIG.  15   . The pedestal  70  has a rectangular plate-shaped base portion  95  and a substantially rectangular plate-shaped first wall  77  extending from a support leg rising from a center portion in the longitudinal direction of the base portion  95  along the longitudinal direction of the base portion  95 . Further, a substantially rectangular plate-shaped second wall  78  rises from the base portion  95  in parallel to the first wall  77 . The first wall  77  and the second wall  78  are separated from each other in a width direction of the base portion  95 . 
     A rectangular plate-shaped third wall  79  that straddles the first wall  77  and the second wall  78  is connected to an end portion of the first wall  77 . The third wall  79  is provided with a first fixing protrusion  73  on a surface opposite to the first wall  77 . The first fixing protrusion  73  is a cylindrical protrusion having a split groove. The first fixing protrusion  73  has a retainer which is slightly thick at an end portion thereof. 
     The base portion  95  has a thick plate portion  741  which is thicker than other portions on the third wall  79  side in the longitudinal direction and on the first wall  77  side in the width direction. The distal tip of the thick plate portion  741  is chamfered. The base portion  95  has a second engagement portion  72  at the end portion opposite to the third wall  79 , which rises in a substantially semicircular shape over the entire width. The width of the base portion  95  corresponds to the pedestal groove  45 . 
     The first wall  77  has an elevator mounting groove  761 . The elevator mounting groove  761  is an approximately U-shaped groove that has an opening at the end portion on the root side of the first wall  77  and extends parallel to the base portion  95 . 
     The elevator mounting groove  761  is provided with an elevator pivot portion  764  protruding inward at an edge of the opening remote from the base portion  95 . A gap between the inner surface of the elevator mounting groove  761  on the base portion  95  side and the distal tip of the elevator pivot portion  764  forms an inlet to the bottom of the elevator mounting groove  761 . The elevator mounting groove  761  is an example of an elevator support portion of this embodiment. 
     Further, the elevator pivot portion  764  may be provided on the base portion  95  side of the opening. The elevator pivot portion  764  may be provided so as to be opposed from both sides. 
       FIG.  16    is a cross-sectional view of the endoscope cap  50  taken along line XVI-XVI of  FIG.  5   . A XVI-XVI cross section is a cross section cutting the first wall  77  in a thickness direction along the longitudinal direction of the insertion portion  30 . A configuration of the endoscope cap  50  will be described with reference to  FIGS.  9  to  11 ,  15 , and  16   . 
     At the bottom of the cover  52 , a pedestal fixing hole  57  is provided. The pedestal fixing hole  57  is a stepped through hole having a large diameter portion on the outer surface side of the cover  52 . The small diameter portion of the pedestal fixing hole  57  has a tapered shape expanding toward the inner surface of the cover  52 . The inner diameter of the pedestal fixing hole  57  corresponds to the outer diameter of the first fixing protrusion  73 . 
     The cover  52  has a second fixing protrusion  58  on the inner surface. The second fixing protrusion  58  is a protrusion protruding from the end of the pedestal groove  45  toward the opening end portion  56  side. The distance between the second fixing protrusion  58  and the bottom of the pedestal groove  45  corresponds to the thickness of the thick plate portion  741 . 
     An outline of a method for assembling the endoscope cap  50  will be described. With the first fixing protrusion  73  side of the pedestal  70  first, the base portion  95  and the pedestal groove  45  of the cover  52  are aligned in the circumferential direction. The pedestal  70  is pushed into the cover  52 . 
     The first fixing protrusion  73  is elastically deformed and passes through the small diameter portion of the pedestal fixing hole  57 . After the retainer of the first fixing protrusion  73  has passed through the small diameter portion of the pedestal fixing hole  57 , the first fixing protrusion  73  elastically returns. The second fixing protrusion  58  and the thick plate portion  741  engage. As described above, the pedestal  70  and the cover  52  are fixed. Further, an adhesive may be applied to the pedestal groove  45  and the like, and the pedestal  70  and the cover  52  may be bonded and fixed. 
       FIG.  17    is a perspective view of the lever  60 . The lever  60  has the lever shaft  63  at one end and the wire fixing portion  65  at the other end. The elevator base connection portion  61 , which is the axis of the rectangular cross section, protrudes from one end surface of the lever shaft  63  in the same direction as the central axis of the lever shaft  63 . In the following description, a plate-shaped portion connecting the lever shaft  63  and the wire fixing portion  65  is referred to as a rotating connection portion  64 . The rotating connection portion  64  protrudes from the end portion of the lever shaft  63  on the opposite side of the elevator base connection portion  61  in a direction intersecting the central axis of the lever shaft  63 . The rotating connection portion  64  rotates within the lever chamber  69  as illustrated in  FIG.  8   . 
     Two O-rings  62  are mounted to the lever shaft  63 . Returning to  FIG.  7   , the description will be continued. The lever shaft  63  is inserted into a hole provided in the support wall  68  from the lever chamber  69  side, and the lever  60  is rotatably supported in a state where the elevator base connection portion  61  faces the optical housing portion  33 . The hollow lever chamber  69  is water-tightly sealed by the O-ring  62  and the lever chamber lid  67 . 
       FIG.  18    is a cross-sectional view of the distal tip of the insertion portion  30  from which the endoscope cap  50  is dismounted.  FIG.  18    is a cross section taken along the line XVI-XVI of  FIG.  5   , similar to  FIG.  16   , and illustrates a state in which the elevator  80  is mounted to the distal tip of the insertion portion  30 . 
     The elevator base connection portion  61  described with reference to  FIG.  7    is engaged with the lever connection portion  81  described with reference to  FIG.  12   . The endoscope cap  50  described with reference to  FIG.  16    is placed and fixed on the elevator  80  and the distal tip  31  from the left side in  FIG.  18   . 
       FIG.  19    is a cross-sectional view of the insertion portion  30  taken along line XIX-XIX of  FIG.  4   . A XIX-XIX cross section is a cross section cutting the insertion portion  30  in the longitudinal direction at a position of the elevator base connection portion  61 .  FIG.  20    is a cross-sectional view of the insertion portion  30  taken along line XX-XX of  FIG.  4   . A XX-XX cross section is a cross section cutting the insertion portion  30  in the longitudinal direction at a position of the elevator shaft  82 .  FIG.  21    is a cross-sectional view of the insertion portion  30  taken along line XXI-XXI of  FIG.  20   . A XXI-XXI cross section is a cross section cut perpendicularly to the longitudinal direction of the insertion portion  30  at the position of the elevator shaft  82 . A configuration in which the elevator  80  and the endoscope cap  50  are fixed to the distal tip of the insertion portion  30  will be described with reference to  FIGS.  19  to  21   . 
     The endoscope cap  50  has the opening end portion  56  facing the distal tip  31  side. As illustrated in  FIG.  19   , the first engagement portion  46  on the inner surface of the endoscope cap  50  is engaged with the third engagement portion  29  on the distal tip  31 . In the engagement portion, the first wedge surface  461  abuts on a surface of the third engagement portion  29  on the operation unit side. 
     Similarly, the second engagement portion  72  on the inner surface of the endoscope cap  50  is engaged with the fourth engagement portion  28  on the distal tip  31 . The endoscope cap  50  is fixed to the distal tip  31  as the endoscope cap  50  is engaged with the distal tip  31  at two opposing places on the inner surface. 
     The elevator base connection portion  61 , which is the axis of the rectangular cross section, is inserted into the lever connection portion  81  of the U-shaped groove type. As a result, the lever  60  is engaged with the elevator  80 . 
     As illustrated in  FIG.  20   , the elevator mounting groove  761  and the elevator shaft  82  engage. The elevator  80  is supported at both ends by the elevator mounting groove  761  and the elevator base connection portion  61 . As illustrated in  FIG.  21   , the lever shaft  63  and the elevator shaft  82  are coaxial. The elevator  80  smoothly rotates around the lever shaft  63  and the elevator shaft  82 . 
       FIG.  22    is a cross-sectional view of the insertion portion  30  taken along line XXII-XXII of  FIG.  4   . A second flat surface portion  322  and a third flat surface portion  323 , formed by flatly cutting a part of the circumferential surface of the distal tip  31 , are formed on the outer side of the optical housing portion  33 . The second flat surface portion  322  and the third flat surface portion  323  are continuous with an angle. 
     An inner surface of the tubular portion of the cover  52  opposes the second flat surface portion  322  and the third flat surface portion  323  with a space therebetween, thereby forming a first cavity portion  93 . The concave portion  48  is arranged at a position corresponding to the first cavity portion  93 . The cover  52  is dented on the inner surface of the tubular portion to be thin on the opposite side of the concave portion  48 . The inner surface of the thin portion of the cover  52  and the lever chamber lid  67  oppose each other with a space therebetween, thereby forming a second cavity portion  94 . A head portion of the lid screw  66  is arranged inside the second cavity portion  94 . That is, the second cavity portion  94  is a space for housing the head portion of the lid screw  66  which is a fixing member that fixes the lever chamber lid  67 . 
     When dismounting the endoscope cap  50 , the user presses two places of the concave portion  48  and the opposite side thereof with fingers as indicated by the white arrows in  FIG.  22   . The cover  52  is deformed since the first cavity portion  93  and the second cavity portion  94  exist on the back side of portions to be pressed. Incidentally, the concave portion  48  is thinner than the other portion in the circumferential direction of the cover  52  as described above, and is a flexible portion that is easily flexed by being pushed with the finger or the like. 
     The user can easily deform the endoscope cap  50  by pressing with a finger. Due to this deformation, the engagement between the first engagement portion  46  and the third engagement portion  29  and the engagement between the second engagement portion  72  and the fourth engagement portion  28  are released. 
     As the user pulls the endoscope cap  50  to the distal tip side while pressing the endoscope cap  50 , the engagement between the lever connection portion  81  and the elevator base connection portion  61  is also released. The user can remove the endoscope cap  50  from the insertion portion  30  with the endoscope cap  50  still connected to the elevator  80 . 
     A procedure for mounting the elevator  80  and the endoscope cap  50  to the distal tip of the insertion portion  30  will be described. The user grips the elevator  80  with a finger or the like. The user adjusts the orientation of the elevator base connection portion  61  and the lever connection portion  81 . 
     The user inserts the elevator  80  from the distal tip side of the insertion portion  30 . The elevator base connection portion  61  enters the lever connection portion  81 . As described above, the elevator  80  is temporarily stopped to the distal tip of the insertion portion  30 . 
     Further, a slip stopper formed by dimples, shallow grooves, or the like may be provided on the surface of the elevator  80 . The work of the user gripping the elevator  80  and mounting it to the distal tip of the insertion portion  30  becomes easy. 
     Thereafter, the user adjusts the position of the endoscope cap  50  in the circumferential direction with respect to the distal tip  31  using the window portion  53  and the recessed portion  84  as marks. The user pushes the endoscope cap  50  into the distal tip of the insertion portion  30 . As illustrated in  FIG.  11   , the second wedge surface  462  of the first engagement portion  46  is inclined with respect to the longitudinal direction of the tubular portion of the cover  52 , and thus, the first engagement portion  46  is hardly caught by the distal tip  31 . 
     The first engagement portion  46  is pushed into the third engagement portion  29  while being elastically deformed. When the first wedge surface  461  enters the third engagement portion  29 , the first engagement portion  46  elastically returns and engages with the third engagement portion  29 . 
     As illustrated in  FIG.  19   , since the second engagement portion  72  is a protrusion that protrudes in a substantially semicircular shape, the second engagement portion  72  is easily pushed into the fourth engagement portion  28 . The second engagement portion  72  is also pushed into the fourth engagement portion  28  while being elastically deformed. The second engagement portion  72  is elastically restored when it enters the fourth engagement portion  28 , and engages with the fourth engagement portion  28 . 
     In this process, the elevator shaft  82  provided on the elevator  80  hits the elevator pivot portion  764  provided on the edge of the elevator mounting groove  761  inside the endoscope cap  50 . When the user further pushes the endoscope cap  50 , the elevator pivot portion  764  rides on the elevator shaft  82 . Due to the elastic deformation, the space between the elevator mounting grooves  761  is increased. 
     The elevator shaft  82  enters the inside of the elevator pivot portion  764 . Thereafter, the position of the elevator pivot portion  764  returns to the original position due to the elastic return. As described above, the endoscope cap  50  is mounted to the distal tip of the insertion portion  30 . 
     As illustrated in  FIG.  19   , the tube-shaped channel  34  is connected to the channel outlet  35  provided at the distal tip  31 . The channel outlet  35  spreads in a trumpet shape toward the window portion  53 . The curved portion  27  that gently protrudes toward the distal tip side is provided in the vicinity of the third engagement portion  29  of the channel outlet  35 , that is, on a peripheral edge portion on a side where the elevator  80  rises as viewed from the channel outlet  35 . 
       FIG.  23    is a cross-sectional view of the insertion portion  30  with the elevator  80  raised.  FIG.  23    illustrates the same cross section as  FIG.  20   . A configuration for raising the elevator  80  will be described with reference to  FIGS.  7 ,  8 ,  17 ,  19 ,  21 , and  23   . 
     The lever shaft  63  is inserted through a through-hole provided in the support wall  68  from the lever chamber  69  side, and the elevator base connection portion  61  protrudes to the opposite side of the support wall  68  as illustrated in  FIG.  7   . As described above, the lever chamber  69  is water-tightly sealed by the O-ring  62  and the lever chamber lid  67 . Therefore, body fluid or the like does not adhere to the inside of the lever chamber  69  and a path of the elevation wire  24  during the use of the endoscope  10 . 
     The elevator  80  is housed inside the cover  52  in the state illustrated in  FIG.  19   . The recessed portion  84  is arranged at a position where the treatment tool distal tip  41  protruding from the channel outlet  35  can be gently curved upward in  FIG.  19   . 
     As described above, the lever  60  rotates about the lever shaft  63  as the axis as the user operates the elevation operation lever  21 . The elevator base connection portion  61  rotates integrally with the lever shaft  63 . As described with reference to  FIG.  21   , the lever shaft  63  and the elevator shaft  82  are coaxial. Since the elevator base connection portion  61  is connected to the lever connection portion  81 , the elevator  80  also rotates integrally with the lever  60 . As a result, a distance between the elevator  80  and the window portion  53  changes. 
       FIG.  23    illustrates a state where the elevator  80  is rotated. The treatment tool distal tip  41  protruding from the channel outlet  35  is raised as being pushed by the elevator  80 . The treatment tool distal tip  41  is pushed further into the operation unit side by the edge on the distal tip side of the recessed portion  84  from the state of being pushed against the distal tip of the curved portion  27 . 
     An overview of a method for using the endoscope  10  of this embodiment will be described. The endoscope  10  is stored in a state where the elevator  80  and the endoscope cap  50  have been removed, and cleaning or the like has been performed. The elevator  80  and the endoscope cap  50  are provided in a state of being sealed in a sterilization pack individually or for each set, and then placed in a paper box in units of 10 or 10 sets, for example, and then subjected to electron beam sterilization. The number of the elevators  80  and the endoscope caps  50  to be placed in the paper box is desirably a minimum sales unit, that is, a minimum unit to be sold to the user at one time. 
     Incidentally, the materials of the cover  52  which is a component of the endoscope cap  50  and the pedestal  70 , and the material of the elevator  80  are desirably materials which are highly durable for electron beam sterilization such as polypropylene and polycarbonate of a radiation resistance grade. 
     The user takes out the elevator  80  from the sterilization pack. The user mounts the elevator  80  to the endoscope  10  according to the above-described procedure. Then, the user takes out the endoscope cap  50  from the sterilization pack. The user mounts the endoscope cap  50  to the insertion portion  30  according to the procedure described above. The user confirms that the endoscope cap  50  is firmly fixed to the distal tip of the insertion portion  30  by lightly pulling the endoscope cap  50  or the like. 
     The user inserts the insertion portion  30  from a mouth of a person to be examined. The user guides the distal tip of the insertion portion  30  to a target site while observing a captured image through the observation window  36 . The user inserts the treatment tool  40  or the like from the channel inlet  22  in accordance with a purpose. After confirming that the treatment tool distal tip  41  protrudes from the distal tip of the insertion portion  30  and is positioned in the vicinity of the target site, the user operates the elevation operation lever  21  to guide the treatment tool distal tip  41  to the target site. After performing a necessary measure and the like, the user removes the treatment tool  40  from the channel  34 . The user removes the endoscope  10  from the subject to be examined and ends the examination or treatment. 
     After the end of the examination or the procedure, the user dismounts the endoscope cap  50  from the endoscope  10  by pushing the cover  52  with two fingers and pulling it toward the distal tip side as described above. As described above, the elevator  80  and the endoscope cap  50  are removed together from the endoscope  10 . 
     Incidentally, it is difficult to consider a case where an external force enough to deform the cover  52  is applied simultaneously at two portions of the cover  52  when observation and treatment are performed using the endoscope  10  by a general method. Since the flange  85  covers one surface of the lever connection portion  81 , the rigidity of the lever connection portion  81  is increased. Therefore, when performing observation and treatment using the endoscope  10  in a normal manner, it is unlikely that the lever connection portion  81  is deformed and an external force is applied to the extent that the lever connection portion  81  is disengaged from the elevator base connection portion  61 . 
     The user performs processing such as cleaning on the endoscope  10  after removing the endoscope cap  50  and the elevator  80  in preparation for the next use. The elevator base connection portion  61  used for fixing the elevator  80  is exposed at the distal tip  31  as illustrated in  FIG.  7   . 
     As described above, the endoscope  10  of this embodiment does not need any special cleaning work or the like to clean the complicated structure in the vicinity of the elevator  80 . As described above, since the body fluid or the like does not adhere to the inside of the lever chamber  69  and the path of the elevation wire  24  during the use of the endoscope  10 , cleaning of these portions is not required. 
     Therefore, it is possible to provide the endoscope  10  with the elevator which can be operated efficiently with a short processing time between cases. According to this embodiment, operability at the time of ending an endoscopic examination procedure can be improved, that is, the operation of dismounting the endoscope cap  50  and the elevator  80  from the endoscope  10  at the same time, and easy cleaning of the endoscope  10  both can be made compatible. 
     The endoscope  10  of this embodiment is provided with the elevator  80  and is the side-view type, and thus, is suitable for diagnosis and treatment of duodenum and a pancreaticobiliary region. In particular, the endoscope  10  of this embodiment is suitable when performing procedures such as endoscopic retrograde cholangio pancreatography (ERCP), endoscopic sphincterotomy (EST), and endoscopic biliary drainage (EBD). This is because the treatment tool  40  is guided inside duodenal papilla on a duodenal wall and a pancreatic duct and a common bile duct which are open to the duodenal papilla to perform treatment and the like in these procedures. 
     Incidentally, the side-view type endoscope  10  is sometimes referred to as a side-view endoscope. Similarly, the endoscope  10  suitable for diagnosis of the duodenum and pancreaticobiliary region is sometimes referred to as a duodenoscope. 
     According to this embodiment, the pedestal  70  and the cover  52  are separate bodies, and thus, have simple shapes. Thus, it possible to produce the pedestal  70  and the cover  52  at low cost by, for example, injection-molding or the like. 
     The user may select and use the endoscope cap  50  having a specification corresponding to a procedure from a plurality of types of the endoscope caps  50  having different specifications. For example, when using expensive and precise equipment such as an ultrasonic probe or an ultra-fine endoscope in combination, an endoscope cap  50  having a function of limiting the rotation range of the elevator  80  narrow to prevent damage to the equipment due to excessive bending may be provided. 
     The recessed portion  84  provided in the elevator  80  has a function of holding the treatment tool distal tip  41  and making it hard to shake right and left. The user may select and use the elevator  80  having specifications according to the procedure from a plurality of types of elevators  80  having different shapes of the recessed portions  84 . For example, in a procedure that requires precise manipulation of a thin treatment tool  40  such as a guide wire, an elevator  80  having a recessed portion  84  suitable for the thin treatment tool  40  is used. 
     In this manner, it is possible to provide the endoscope  10  which enables the user to select and use the elevator  80  and the endoscope cap  50  suitable for an application. Further, the elevator  80  and the endoscope cap  50  of the combination recommended for each application may be provided as a set. 
     The endoscope  10  may be a so-called endoscopic ultrasonography including an ultrasonic transducer at a distal tip thereof. In this case, the endoscope cap  50  desirably has a hole through which the ultrasonic transducer is inserted, at a bottom thereof. The endoscope  10  may be an endoscope for a lower gastrointestinal tract. The endoscope  10  may be a so-called rigid scope provided with the rigid insertion portion  30 . The endoscope  10  may be a so-called industrial endoscope used for an examination of an engine, piping, and the like. 
     The endoscope cap  50  and the elevator  80  of this embodiment are each a so-called single use, and are discarded after being used once. 
     The endoscope cap  50  may be reusable. In this case, the user dismounts the elevator  80  from the endoscope cap  50  dismounted from the insertion portion  30 . The endoscope cap  50  is visually inspected by the user, and if it is not damaged, the endoscope cap  50  is subjected to processing such as cleaning and reused. Since the opening end portion  56  of the endoscope cap  50  is widely open, the processing such as cleaning can be easily performed as compared with the state of being mounted to the insertion portion  30 . Since the endoscope cap  50  is small, it is also easy to place the endoscope cap  50  in the sterilization pack, for example, and perform autoclave sterilization or the like. 
     After disassembling the endoscope cap  50  into the cover  52  and the pedestal  70 , a process such as cleaning may be performed, and the endoscope cap  50  may be reused after being reassembled. By disassembling, cleaning and the like can be performed more reliably. 
     The elevator  80  may be reusable. In this case, the user visually inspects the elevator  80  dismounted from the endoscope cap  50 , and performs processing such as cleaning for the reuse when there is no damage. Since the elevator  80  is small, it is also easy to place the elevator in the sterilization pack, for example, and perform autoclave sterilization or the like. If reusable, the elevator  80  may be made of a highly durable material such as metal or ceramics. 
     The lever connection portion  81  may have the same retainer at the end of the opening as the elevator pivot portion  764 . After the elevator base connection portion  61  and the lever connection portion  81  are engaged, the endoscope cap  50  can be easily mounted before the endoscope cap  50  is attached without worrying about that the elevator  80  comes off. In this case, the retainer on the lever connection portion  81  side is detached with a weaker force than the retainer on the elevator mounting groove  761  side. 
     Second Embodiment 
     This embodiment relates to the endoscope  10  having the endoscope cap  50  that can be easily mounted. Descriptions regarding common parts with the first embodiment will be omitted. 
       FIG.  24    is a perspective view of the pedestal  70  according to the second embodiment. On the side surface of the elevator mounting groove  761 , an elevator pivot portion  764  protruding oppositely is provided. A tapered portion  762  is provided outside the elevator pivot portion  764  of the elevator mounting groove  761 . The tapered portion  762  has a shape that expands away from the elevator pivot portion  764 . 
       FIG.  25    is a cross-sectional view of the insertion portion  30  of the second embodiment. The elevator shaft  82  is rotatably held between the bottom of the elevator mounting groove  761  and the elevator pivot portion  764 . 
     When the user mounts the endoscope cap  50  to the distal tip of the endoscope  10 , the tapered portion  762  guides the elevator shaft  82 . When the user pushes the endoscope cap  50 , the pedestal  70  is elastically deformed, and the space between the elevator pivot portions  764  is increased. The elevator shaft  82  passes through the space between the elevator pivot portions  764 , and enters the inside of the elevator pivot portions  764 . Thereafter, the elevator pivot portion  764  returns to the original state due to the elastic return. 
     According to this embodiment, it is possible to provide the endoscope  10  having the endoscope cap  50  that can be easily mounted. Further, similarly to the first embodiment, it is possible to provide the endoscope  10  having the endoscope cap  50  and the elevator  80  that can be easily dismounted. 
     Technical features (constitutional requirements) described in the respective embodiments can be combined with each other, and new technical features can be formed with the combination. 
     The embodiments disclosed herein are exemplary in all respects, and it should be considered that the embodiments are not restrictive. The scope of the invention is defined not by the above-described meaning but by claims, and intends to include all modifications within meaning and a scope equal to claims. 
     REFERENCE SIGNS LIST 
     
         
           10  endoscope 
           12  soft portion 
           13  bending section 
           20  operation unit 
           21  elevation operation lever 
           22  channel inlet 
           23  bending knob 
           24  elevation wire (rotating portion) 
           27  curved portion 
           28  fourth engagement portion 
           29  third engagement portion 
           30  insertion portion 
           31  distal tip portion 
           321  first flat surface portion 
           322  second flat surface portion 
           323  third flat surface portion 
           33  optical housing portion 
           34  channel 
           35  channel outlet 
           36  observation window 
           37  illumination window 
           38  nozzle 
           40  treatment tool 
           41  treatment tool distal tip 
           45  pedestal groove 
           46  first engagement portion 
           461  first wedge surface 
           462  second wedge surface 
           48  recess 
           49  protruding portion 
           50  endoscope cap 
           52  cover 
           53  window portion 
           56  opening end portion 
           57  pedestal fixing hole 
           58  second fixing protrusion 
           60  lever 
           61  elevator base connection portion 
           62  O-ring 
           63  lever shaft 
           64  rotating connection portion 
           65  wire fixing portion 
           66  cap screw 
           67  lever chamber lid 
           68  support wall 
           69  lever chamber 
           70  pedestal 
           72  second engagement portion 
           73  first fixing protrusion 
           741  thick plate 
           761  elevator mounting groove (elevator support portion) 
           762  tapered portion 
           764  elevator pivot portion 
           77  first wall 
           78  second wall 
           79  third wall 
           80  elevator 
           81  lever connection portion 
           82  elevator shaft 
           83  elevation portion 
           831  first elevation portion 
           832  second elevation portion 
           84  recessed portion 
           85  flange 
           93  first cavity portion 
           94  second cavity portion 
           95  base portion