Patent Publication Number: US-2023151653-A1

Title: Endoscope and method for locking knob

Description:
RELATED APPLICATION DATA 
     This application is based on and claims priority under 37 U.S.C. § 119 to U.S. Provisional Application No. 63/279,887 filed on Nov. 16, 2021, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to an endoscope including a knob configured to operate an active member and a method for locking the knob configured to operate the active member of the endoscope. 
     BACKGROUND 
     Conventionally, as an endoscope, there is known a configuration in which a bending portion is provided at a distal end portion of an insertion portion. The bending portion is operated to bend in two directions around an axis of the insertion portion or over an entire circumference combining four directions of up, down, left, and right, by a user operating and turning a bending operation knob provided at an operation portion of the endoscope. 
     For example, Japanese Patent Application Laid-Open Publication No. 2011-30866 discloses a technique of an endoscope that enables an operation of angle lock with only one hand by integrating a lock button with an angle knob that is a bending operation knob. 
     The conventional endoscope is configured such that when the lock button is pushed in, a lock ring moves, a top surface of a friction plate and a bottom surface of a top plate abut on each other to generate a frictional force between the top surface and the bottom surface, and thereby the angle knob that is a bending operation knob is locked. 
     SUMMARY OF THE DISCLOSURE 
     An endoscope comprises an insertion portion, an operation portion body provided at a proximal end side of the insertion portion, a knob provided in the operation portion body, the knob configured to rotate around a rotation shaft, and a turn locking mechanism provided in the knob. The turn locking mechanism includes a lock button reversibly translatable from a first position to a second position, a lock bar connected to the lock button, the lock bar extending from an inside surface of the lock button, and a fixed member attached to the operation portion body. When the lock button is in the second position, the lock bar engages the fixed member to prevent the knob from rotating around the rotation shaft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view showing an external appearance of an endoscope according to one aspect of the present disclosure. 
         FIG.  2    is a perspective view partially showing an operation portion. 
         FIG.  3    is a plan view showing a configuration of a bending operation knob. 
         FIG.  4    is a partial cross-sectional view showing a configuration of an operation portion body at which the bending operation knob is provided. 
         FIG.  5    is a cross-sectional view showing a configuration of a UD bending operation knob in which a turning lock mechanism and a lock release mechanism are provided. 
         FIG.  6    is a cross-sectional view showing a configuration of the UD bending operation knob that is turned to a predetermined angle. 
         FIG.  7    is a cross-sectional view showing a configuration of the UD bending operation knob in a state in which a lock button of the turning lock mechanism is pushed in. 
         FIG.  8    is a cross-sectional view showing a configuration of the UD bending operation knob in a state in which a release button of a lock release mechanism is pushed in. 
         FIG.  9    is a partial cross-sectional view showing an operation portion body at which a bending operation knob of a first modification is provided. 
         FIG.  10    is a perspective view partially showing a configuration of a fixed member of the first modification. 
         FIG.  11    is a cross-sectional view showing a configuration of a UD bending operation knob in which a turning lock mechanism of the first modification and a lock release mechanism are provided. 
         FIG.  12    is a cross-sectional view showing a configuration of the UD bending operation knob that is turned to a predetermined angle of the first modification. 
         FIG.  13    is a cross-sectional view showing a configuration of the UD bending operation knob in a state in which a lock button of the turning lock mechanism of the first modification is pushed in. 
         FIG.  14    is a cross-sectional view showing a configuration of the UD bending operation knob in a state in which a release button of the lock release mechanism is pushed in of the first modification. 
         FIG.  15    is a partial cross-sectional view showing an operation portion body at which a bending operation knob of a second modification is provided. 
         FIG.  16    is a partial cross-sectional view showing the operation portion body at which the bending operation knob in a state in which a lock button of a turning lock mechanism of the second modification is pushed in. 
         FIG.  17    is a side view showing a state in which a bent portion of a lock bar is caught by a fixed member of the second modification. 
         FIG.  18    is a plane development view showing a state in which the bent portion of the lock bar is caught by the fixed member of the second modification. 
         FIG.  19    is a partial cross-sectional view showing the operation portion body at which the bending operation knob in a state in which a release button of a lock release mechanism is pushed in of the second modification. 
         FIG.  20    is a side view showing a state in which the bent portion of the lock bar of the second modification is released from the fixed member by a release bar. 
         FIG.  21    is a schematic view showing a lock release mechanism adopting a knock type of a third modification. 
         FIG.  22    is a cross-sectional view showing a configuration of a UD bending operation knob in which a turning lock mechanism of the third modification and a lock release mechanism are provided. 
         FIG.  23    is a cross-sectional view showing a configuration of the UD bending operation knob in which a lock button of the turning lock mechanism of the third modification is pushed in. 
         FIG.  24    is a perspective view partially showing a configuration of a fixed member of a fourth modification. 
         FIG.  25    is a partial cross-sectional view showing a configuration of an operation portion body at which a bending operation knob of a fifth modification is provided. 
         FIG.  26    is a cross-sectional view showing a configuration of a UD bending operation knob in which a turning lock mechanism of the fifth modification and a lock release mechanism are provided. 
         FIG.  27    is a perspective view partially showing configurations of a fixed member and a lock bar of the fifth modification. 
     
    
    
     DETAILED DESCRIPTION 
     Generally, in a bending operation knob configured to operate and bend a bending portion or the like of an endoscope, a large holding force can be applied and therefore it is difficult to fix a turning position reliably with one hand of a user, in order to fix a bending state of the bending portion. In a conventional structure that fixes a bending operation knob, fixation of the bending operation knob may come off unintentionally by a user. 
     According to an embodiment of the present disclosure, it is possible to provide an endoscope and a method for locking a knob that operates an active member of the endoscope that can easily perform fixation of a turning position of the knob configured to operate an active member such as a bending portion with one hand, and reliably fix the knob. The method comprises translating the lock button from the first position to the second position; and engaging the lock bar with the fixed member to prevent the knob from rotating around the rotation shaft. The engaging the lock bar with the fixed member can be the lock bar abutting on the surface. 
     Here, an endoscope that is the present disclosure is described by being cited as an example. Note that in the following explanation, the drawings based on each embodiment are schematic, attention should be paid to the fact that the relationship between the thickness and the width of each part, ratios of the thicknesses of respective parts and the like are different from the actual relationship and ratios, and there may be parts where the relationships and ratios of mutual dimensions are different among the drawings. 
     As an endoscope in the following configuration explanation, there is illustrated an endoscope for a digestive system an insertion portion of which has flexibility to be inserted into a digestive system in an upper part or a lower part of a living body, but the endoscope is not limited to this, and can also be applied to various so-called flexible endoscopes, and a so-called rigid endoscope with a rigid insertion portion that is used for surgery. 
     Hereinafter, an endoscope of one aspect of the present disclosure is described based on the drawings. 
     As shown in  FIG.  1   , an endoscope  1  that is an insertion apparatus is configured by mainly having an insertion portion  2 , an operation portion  3 , a universal cord  4 , and an endoscope connector  5 . 
     The insertion portion  2  is an elongated hollow long member configured to be inserted into an observation target site. The operation portion  3  is provided connectively to a proximal end portion of the insertion portion  2 . The universal cord  4  is provided to extend from a bend preventing portion  17  provided at a side surface of the operation portion  3 . The endoscope connector  5  is provided at an extension end portion of the universal cord  4 . 
     The insertion portion  2  has a distal end portion  6 , a bending portion  7  as an active member, and a flexible tube portion  8 . The distal end portion  6  is a rigid member to be a distal end configuring portion. The bending portion  7  is a movable portion that is bendable and provided connectively to a rear portion of the distal end portion  6 . The flexible tube portion  8  is formed by a soft and tubular member at a rear portion of the bending portion  7 , is long and has flexibility. 
     In the distal end portion  6 , an observation optical system, an illumination optical system, an air-feeding and water-feeding nozzles, and a suction opening not illustrated are provided. Note that illumination light that is emitted to a subject from the illumination optical system here is radiated from a light source of an external apparatus not illustrated to which the endoscope connector  5  is connected, and is transmitted to the distal end portion  6  via a light guide bundle placed in the insertion portion  2 . Note that the light source may be an LED or the like contained in the operation portion  3 . 
     The operation portion  3  is configured by having an operation portion body  10  configuring an operation grasping portion, a bend preventing portion  9  that is connected to a proximal end side of the flexible tube portion  8  of the insertion portion  2 , and a treatment instrument insertion opening  11  that is placed in a vicinity of the bend preventing portion  9  and to be an opening portion of an insertion channel not illustrated in the insertion portion  2 . 
     In the operation portion body  10 , two bending operation knobs  21  and  22  for operating and bending the bending portion  7  of the insertion portion  2  are turnably placed as shown in  FIG.  2   . In the operation portion body  10 , buttons  13  for mainly performing suction, air feeding and water feeding, switches  14  configured to perform various endoscope functions, mainly an operation of an image pickup system and the like are provided (see  FIG.  1   ). The two bending operation knobs  21  and  22  are provided in the operation portion body  10 , and the two bending operation knobs  21  and  22  are configured to rotate around a rotation shaft  27 . 
     Note that the bending operation knobs  21  and  22  are configured by a UD bending operation knob  21  for operating and bending the bending portion  7  in an up-down direction, and an RL bending operation knob  22  for operating and bending the bending portion  7  in a left-right direction. The UD bending operation knob  21  and the RL bending operation knob  22  are placed by being superimposed on a same axis to be a rotation axis (see  FIG.  2   ). 
     The endoscope connector  5  is configured to be electrically connected to external apparatuses such as a video processor and a light source apparatus not illustrated removably. 
     Here, detailed configurations of the UD bending operation knob  21  and the RL bending operation knob  22  that operate and bend the bending portion  7  that is an active member provided at the insertion portion  2  of the endoscope  1  are described below. 
     As shown in  FIG.  3   , the two UD bending operation knob  21  and RL bending operation knob  22  are both disk-shaped members including four finger rest portions  23  and  24  extending at positions that are turned 90° circumferentially. Note that the numbers of finger rest portions  23  and  24  are not limited as long as the numbers are plural. 
     As shown in  FIG.  4   , a cylindrical rotation shaft  27  is connected to the UD bending operation knob  21 . The rotation shaft  27  is fixed to a bearing  18  provided in the operation portion body  10  and is turnably held. Note that in the operation portion body  10 , an O-shaped ring  19  that is in contact with the rotation shaft  27  to hold the rotation shaft  27  in a watertight manner is provided. 
     The rotation shaft  27  is provided with a pulley  61  at an end portion inside of the operation portion  3 . On the pulley  61 , a UD bending operation wire  63  is placed. The UD bending operation wire  63  is inserted through an inside of the insertion portion  2 , and is connected to a bending tube such as a bending piece not illustrated and provided in the bending portion  7 . 
     When the UD bending operation knob  21  is operated to turn, the pulley  61  also turns, and the UD bending operation wire  63  is pulled or loosened. Thereby, the bending tube such as a bending piece in the bending portion  7  turns in an up-down direction, and thereby the bending portion  7  is bent up and down. 
     Note that at the UD bending operation knob  21 , a lock button  31  of a turn locking mechanism  30  is placed at one finger rest portion  23  of the four finger rest portions  23 , and a release button  41  of a lock release mechanism  40  is placed at one finger rest portion  23  on which the lock button  31  is not provided among the four finger rest portions  23 . Detailed configuration explanation of the turn locking mechanism  30  and the lock release mechanism  40  is described later. 
     The UD bending operation knob  21  is provided with an annular member  25  in a circular recessed portion  21   a . The annular member  25  has a plurality of hole portions  26  and  29  formed in a side peripheral portion, and is connected to the rotation shaft  27 . 
     A rod-shaped rotation shaft  28  is connected to the RL bending operation knob  22 . The rotation shaft  28  is inserted through an inside of the rotation shaft  27  of the UD bending operation knob  21  and is turnably held. 
     The rotation shaft  28  is provided with a pulley  62  at an end portion inside of the operation portion  3 . On the pulley  62 , an RL bending operation wire  64  is placed. The RL bending operation wire  64  is also inserted through the inside of the insertion portion  2  and is connected to a bending tube such as a bending piece not illustrated and provided in the bending portion  7 . 
     When the RL bending operation knob  22  is operated to turn, the pulley  62  also turns, and the RL bending operation wire  64  is pulled or loosened. Thereby, the bending tube such as the bending piece in the bending portion  7  turns in a left-right direction, and thereby the bending portion  7  is bent left and right. 
     A bending mechanism that can actively move the bending portion  7  up, down, left and right (UD-RL) described above is well-known, and therefore, explanation concerning the other components is omitted. 
     Here, detailed configurations of the turn locking mechanism  30  and the lock release mechanism  40  that are provided in the UD bending operation knob  21  are described below. 
     The turn locking mechanism  30  has the lock button  31 , lock bars  33 , a coil spring  35 , and a fixed member  51 , as shown in  FIG.  4    and  FIG.  5   . The lock button  31  is reversibly translatable from a first position to a second position, a lock bar  33  is connected to the lock button  31 , the lock  33  bar extends from an inside surface of the lock button  31 , and a fixed member  51  is attached to the operation portion body  10 . When the lock button  31  is in the second position, the lock bar  33  engages the fixed member  51  to prevent the bending operation knob  21  from rotating around the rotation shaft  27 . The lock bar  33  is a first lock bar  33  and the turn locking mechanism includes a second lock bar  33 , the first lock bar  33  is separated from the second lock bar  33  with the rotation shaft  27  interposed therebetween, and when the lock button  31  is in the second position, at least one of the first lock bar  33  and the second lock bar  33  engages with or penetrates completely or penetrates partially the fixed member  51  to prevent the bending operation knob  21  from rotating around the rotation shaft  27 . 
     In the lock button  31 , a rod-shaped projection  32  that is inserted through the coil spring  35  is provided to extend in a center direction of the UD bending operation knob  21 . The lock button  31  is provided at one of the finger rest portions  23  of the UD bending operation knob  21 . The lock button  31  is provided to be able to protrude and retract in directions of a center and an outer periphery of the UD bending operation knob  21 . 
     Note that in the finger rest portion  23  at which the lock button  31  is provided, a button accommodation portion  23   a  that is a hole portion formed in a thick-walled portion of an end portion is formed, and the lock button  31  is movably fitted in the button accommodation portion  23   a.    
     In the lock button  31 , a flange  31   a  is formed. The flange  31   a  abuts on an abutment surface  23   b  which serves as a wall portion of the recessed portion  21   a  of the UD bending operation knob  21 , to thereby prevent the lock button  31  from slipping off from the button accommodation portion  23   a.    
     The lock bar  33  has a sharp pointed end portion  33   a  at a distal end, and two lock bars  33  are provided here. Each of the two lock bars  33  has one end connected to the lock button  31 . The two lock bars  33  extend from the end surface of the lock button  31  and are disposed parallel with the rotation shaft  27  being interposed between the two lock bars  33 . The fixed member  51  includes an elastic material. When the lock button  31  is in the second position and the lock bar  33  engages the fixed member  51 , the pointed end portion  33   a  pierces a surface of the elastic material. 
     Note that the two lock bars  33  are formed of a rigid metal or the like, and inserted through the respective hole portions  26  of the annular member  25 . 
     The coil spring  35  that is an urging member is provided between the lock button  31  and the annular member  25 . The coil spring  35  is disposed to abut on the end surface of the lock button  31  and an outer peripheral surface of the annular member  25  and urges the lock button  31  outward. 
     The fixed member  51  is formed of an elastic body such as rubber, and is an arc-shaped block body. The fixed member  51  is fixed to a seat  16  formed to project on an outer surface side of the operation portion body  10  so as to protrude inside of the annular member  25  of the recessed portion  21   a  of the UD bending operation knob  21 . 
     The lock release mechanism  40  has the release button  41 , release bars  43 , and a coil spring  45 . The lock release mechanism  40  is provided in the bending operation knob  21 . 
     In the release button  41 , a rod-shaped projection  42  that is inserted through the coil spring  45  is provided to extend in the center direction of the UD bending operation knob  21 . The release button  41  is provided at one of the finger rest portions  23 , located at a symmetrical position at an opposite side to the finger rest portion  23  at which the lock button  31  of the turn locking mechanism  30  is provided. The release button  41  is also provided to be able to protrude and retract in the directions of the center and the outer periphery of the UD bending operation knob  21 . 
     Note that in the finger rest portion  23  at which the release button  41  is provided, the button accommodation portion  23   a  that is a hole portion formed in a thick-walled portion at an end portion is also formed, and the release button  41  is movably fitted into the button accommodation portion  23   a.    
     Further, also at the release button  41 , a flange  41   a  is formed. The flange  41   a  abuts on an abutment surface  23   b  which serves as the wall portion of the recessed portion  21   a  of the UD bending operation knob  21 , to thereby prevent the release button  41  from slipping off from the button accommodation portion  23   a . The release button  41  is reversibly translatable from a third position to a fourth position. 
     Two release bars  43  are provided here. One end of each of the two release bars  43  is connected to the release button  41 . The two release bars  43  extend from an end surface of the release button  41 , and an extension end of each of the release bars  43  is disposed parallel to face one of the two lock bars  33 . The release bar  43  is connected to the release button  41 , the release bar  43  extends from an inside surface of the release button  41  and having an end portion, the end portion of the release bar  43  faces an end portion of the lock bar  33 . The reversible translation of the lock button from the first position to the second position is along a first axis, the reversible translation of the release button from the first position to the second position is along a second axis, and the first axis and the second axis are coaxial. 
     Note that the two release bars  43  are formed of a rigid metal, a synthetic resin or the like. In the annular member  25 , the hole portions  29  through which the release bars  43  can be inserted are formed on respective extension lines on which the two release bars  43  extend. 
     The coil spring  45  that is an urging member is also provided between the release button  41  and the annular member  25 . The coil spring  45  is disposed to abut on the end surface of the release button  41  and an outer peripheral surface of the annular member  25 , and urges the release button  41  outward. 
     Operations of a state of locking (fixing) a turning position of the UD bending operation knob  21 , and a state of releasing locking (fixing), by the turn locking mechanism  30  and the lock release mechanism  40  configured as above are described in detail below. 
     A user operates and turns the UD bending operation knob  21  around the rotation shaft  27  as shown in  FIG.  5    and  FIG.  6   , when operating and bending the bending portion  7  that is an active member provided at the insertion portion  2  of the endoscope  1  in the up-down direction here. Note that here, a state in which the UD bending operation knob  21  is operated to turn to a predetermined angle in a right-hand (clockwise shown by an arrow) direction as seen toward the paper surface of the drawing is illustrated here. 
     When the user desires to maintain (fix) a state in which the bending portion  7  is desirably bent, the user pushes in the lock button  31  of the turn locking mechanism  30 , which is provided at one of the finger rest portions  23  as shown in  FIG.  7   , in order to lock (fix) the turning position of the UD bending operation knob  21 . 
     At this time, the lock button  31  is pushed in in an arrow FL direction, and thereby slidingly moves to the center side of the UD bending operation knob  21  against a biasing force of the coil spring  35 . In association with this, the two lock bars  33  provided to extend from the lock button  31  also move to the center side of the UD bending operation knob  21 . 
     Here, the pointed end portion  33   a  of one of the two lock bars  33  is pierced to penetrate through the fixed member  51 . In other words, since the pointed end portion  33   a  of the lock bar  33  abuts on the fixed member  51  through which the pointed end portion  33   a  penetrates by piercing to a direction in which the UD bending operation knob  21  turns, the turning position of the UD bending operation knob  21  is locked. Thereby, the turning position of the UD bending operation knob  21  is locked. Then, the fixed member  51  extends 90° in a circumferential direction of the rotation shaft  27 , the fixed member  51  extends to include other angles that have the same effect as 90°. 
     Note that a frictional resistance force when the pointed end portion  33   a  pierces the fixed member  51  is set to be larger than a repulsive force by the coil spring  35  that urges the lock button  31 , and to be able to continue to lock the turning position of the UD bending operation knob  21 . 
     When the user desires to release fixation of the turning position of the UD bending operation knob  21 , the user pushes in the release button  41  of the lock release mechanism  40 , which is provided at an opposite side of the finger rest portion  23 , as shown in  FIG.  8   . 
     At this time, the release button  41  is pushed in in an arrow FC direction, and thereby slidingly moves to the center side of the UD bending operation knob  21  against a biasing force of the coil spring  45 . In association with this, the two release bars  43  provided to extend from the release button  41  also move to the center side of the UD bending operation knob  21 . 
     The two release bars  43  are inserted through the respective hole portions  29  of the annular member  25 . At this time, extension ends of the two release bars  43  abut on the respective pointed end portions  33   a  of the two lock bars  33 , and push in the pointed end portions  33   a  in a direction in which the two release bars  43  move. 
     Thereby, the lock bar  33  that pierces the fixed member  51  removes from the fixed member  51 , and locking of the UD bending operation knob  21  is released. At this time, the lock button  31  and the two lock bars  33  of the turn locking mechanism  30  move in an arrow FR direction that is an outer periphery direction of the UD bending operation knob  21  by the biasing force of the coil spring  35 . Thereby, the UD bending operation knob  21  is brought into a state in which the UD bending operation knob  21  can perform a free turning operation without being fixed by the turn locking mechanism  30 . 
     As described above, the endoscope  1  of the present embodiment is configured such that the turn locking mechanism  30  configured to fix the turning position of the UD bending operation knob  21  and the lock release mechanism  40  are provided in the UD bending operation knob  21  configured to operate and bend the bending portion  7  that is an active member provided at the insertion portion  2 , and thereby the user can easily operate lock and release of the UD bending operation knob  21  with one hand. 
     The user can easily lock the turning position of the UD bending operation knob  21  by only pushing in the lock button  31  of the turn locking mechanism  30  with a finger of one hand that operates the UD bending operation knob  21  when fixing the bending portion  7  in a bending state. Therefore, the user can fix the bending portion  7  in the bending state without continuing to hold the turning position of the UD bending operation knob  21 . 
     Further, the user can easily release locking of the UD bending operation knob  21  by only pushing in the release button  41  of the lock release mechanism  40  with a finger of one hand that operates the UD bending operation knob  21  when releasing the bending portion  7  that is fixed in a bending state. 
     Note that fixation of the UD bending operation knob  21  is not released as long as the user does not intentionally push in the release button  41  of the lock release mechanism  40 , but can reliably hold fixation of the turning position of the UD bending operation knob  21  if the user lightly presses the lock button  31  of the turn locking mechanism  30 . 
     In the above, the configuration in which the turn locking mechanism  30  and the lock release mechanism  40  are provided in only the UD bending operation knob  21  is illustrated, but as a matter of course, the lock button  31  and the release button  41  may be provided at the finger rest portions  24  of the RL bending operation knob  22 , and the turn locking mechanism  30  and the lock release mechanism  40  may be provided in the RL bending operation knob  22 , without being limited to the above configuration. 
     From the above, the endoscope  1  of the preset embodiment can be configured such that fixation of the turning positions of the bending operation knobs  21  and  22  that operate the active member such as the bending portion  7  can be easily performed with one hand of the user, and the bending operation knobs can be reliably fixed. 
     Note that the fixed member  51  is formed of an elastic body such as rubber, is configured to be pierced by the lock bar  33  of the turn locking mechanism  30 , and therefore is suitable for the single-use (disposable) endoscope  1 . 
     (First Modification) 
     A present modification is another aspect of the fixed member of the turn locking mechanism  30 . Therefore, for the components already described in the above, the same reference signs are used, and detailed explanation of the components is omitted. 
     In an endoscope  1  of the present example, an arc-shaped rigid frame body  53  of metal, resin or the like is provided on a seat  16  that is projectingly formed on an outer surface side of an operation portion body  10 , as shown in  FIG.  9    and  FIG.  10   . In the frame body  53 , an opening portion  54  is formed. A sheet-shaped fixed member  52  formed of an elastic body such as rubber is provided to close the opening portion  54  of the frame body  53 . 
     The sheet-shaped fixed member  52  and rigid frame body  53  are included in a turn locking mechanism  30 . 
     Operations in a state of locking (fixing) the turning position of a UD bending operation knob  21  and in a state of releasing locking (fixing) by the turn locking mechanism  30  and a lock release mechanism  40  of the present modification configured like this are described. Note that the same operation content as the aforementioned operation content is omitted or briefly described. 
     When the user also operates and bends a bending portion  7  that is an active member provided at an insertion portion  2  of the endoscope  1  in an up-down direction here, the user operates and turns the UD bending operation knob  21  around a rotation shaft  27  as shown in  FIG.  11    and  FIG.  12   . 
     When the user desires to maintain (fix) a state in which the bending portion  7  is desirably bent, the user can lock (fix) the turning position of the UD bending operation knob  21  by pushing in the lock button  31  of the turn locking mechanism  30  in an arrow FL direction as shown in  FIG.  13   . 
     Here, one pointed end portion  33   a  of two lock bars  33  pierces so as to penetrate through the fixed member  52 . Note that in the lock bar  33 , the pointed end portion  33   a  passes through the frame body  53  by the opening portion  54  of the frame body  53  to pierce and penetrate through the fixed member  52 . In other words, the pointed end portion  33   a  pierces the fixed member  52  without hitting the frame body  53 . An elastic material can cover the opening portion  54 . 
     Since the pointed end portion  33   a  of the lock bar  33  abuts on the pierced fixed member  52  to a direction in which the UD bending operation knob  21  turns, the turning position of the UD bending operation knob  21  is locked. Thereby, the turning position of the UD bending operation knob  21  is locked. 
     Note that a frictional resistance force when the pointed end portion  33   a  pierces the fixed member  52  is set to be larger than a repulsive force by a coil spring  35  that urges the lock button  31 , and to be able to continue to lock the turning position of the UD bending operation knob  21 . 
     When the user desires to release fixation of the turning position of the UD bending operation knob  21 , the user pushes in a release button  41  of the lock release mechanism  40  that is provided at an opposite side of the finger rest portion  23  as shown in  FIG.  14   . 
     As the release button  41  is pushed in in an arrow FC direction, two release bars  43  are inserted through the respective hole portions  29  of an annular member  25 , and push in the two lock bars  33 . 
     Thereby, the lock bar  33  piercing the fixed member  52  removes from the fixed member  51 , and locking of the UD bending operation knob  21  is released. At this time, the lock button  31  and the two lock bars  33  of the turn locking mechanism  30  move in an arrow FR direction in an outer periphery direction of the UD bending operation knob  21  by a biasing force of the coil spring  35 . Thereby, the UD bending operation knob  21  is brought into a state in which the UD bending operation knob  21  can perform a free turning operation without being fixed by the turn locking mechanism  30 . 
     By the above explanation, the endoscope  1  of the present modification can more reliably lock the turning position of the UD bending operation knob  21 , in addition to the aforementioned operational effects, because the fixed member  52  is provided at the rigid frame body  53 , and can be enhanced in rigidity more than the fixed member  51  of the aforementioned embodiment. 
     (Second Modification) 
     A present modification is another aspect of the lock bar and the fixed member of the turn locking mechanism  30 . Therefore, for the components already described in the above, the same reference signs are used, and detailed explanation of the components is omitted. 
     In an endoscope  1  of the present modification, a distal end of the lock bar includes an arc-shaped bent portion  33   b  in seen toward the paper surface of the drawings is provided at an extension end of a lock bar  33  of a turn locking mechanism  30  instead of the pointed end portion  33   a , as shown in  FIG.  15    and  FIG.  16   . The bent portion  33   b  is configured to hook on the fixed member  56 . Further, instead of the fixed member  51  of an elastic body provided on the seat  16 , a rigid fixed member  56  in an arc plate shape of metal, resin or the like is provided. 
     The lock bar  33  here is a metal rod body that is formed of an elastic body such as a leaf spring and has flexibility. As shown in  FIG.  17   , the bent portion  33   b  that is configured to get caught on the fixed member  56  and is prevented from slipping off is formed at the extension end of the lock bar  33 . 
     In the fixed member  56 , an opening portion  57  is formed as shown in  FIG.  17    and  FIG.  18   . In the fixed member  56  here, triangular protruded portions  58  and recessed portions  59  are formed in a row on one side of the opening portion  57  at an upper part seen toward the paper surface of the drawing in a turning direction of the UD bending operation knob  21 . The opening portion  57  extends from an inner surface of the fixed member  56  to an outer surface of the fixed member  56 . The opening includes an edge portion that extends in a first direction, the first direction corresponding to a rotation direction of the bending operation knob  21 . The edge portion includes the protruded portion  57  and the recessed portion  59 , and when the lock button  31  is in the second position and the lock bar  33  engages the fixed member  56 , the lock bar  33  is located in the recessed portion  59 . The edge portion includes a plurality of protruded portions  57  and a plurality of recessed portions  59  arranged alternately in the first direction. The lock bar  33  can be an elastic material. 
     In the turn locking mechanism  30  of the present modification configured like this, the turning position of the UD bending operation knob  21  can also be locked (fixed) by pushing in the lock button  31  of the turn locking mechanism  30 . Locking of the turning position of the UD bending operation knob  21  can be released by pushing in the release button  41  of the lock release mechanism  40 . 
     More specifically, when the lock bar  33  moves by the user pushing in the lock button  31  of the turn locking mechanism  30 , and the bent portion  33   b  abuts on the fixed member  56 , the lock bar  33  flexes, and the bent portion  33   b  crosses the opening portion  57  of the fixed member  56 . 
     Subsequently, the lock bar  33  is fitted into the recessed portion  59 , as shown in  FIG.  16    to  FIG.  18   . In other words, the lock bar  33  is penetrated through the fixed member  56 . 
     At this time, the lock bar  33  tries to return to its pre-penetration form by an elastic force, and the bent portion  33   b  abuts and gets caught on a wall portion beyond the fixed member  56 . 
     Subsequently, the lock bar  33  abuts on a wall surface formed by the protruded portions  58  and the recessed portions  59  of the fixed member  56  to a direction in which the UD bending operation knob  21  turns, and therefore, the turning position of the UD bending operation knob  21  is locked. Thereby, the turning position of the UD bending operation knob  21  is locked. 
     When the user desires to release fixation of the turning position of the UD bending operation knob  21 , the user pushes in the release button  41  of the lock release mechanism  40  as shown in  FIG.  19    and  FIG.  20   . 
     Then, two release bars  43  provided to extend from the release button  41  are inserted through the respective hole portions  29  of an annular member  25 , and extension ends abut on the bent portions  33   b  of the two lock bars  33 . At this time, the two lock bars  33  deform downward as seen toward the paper surface of the drawing, and the bent portions  33   b  move downward, whereby the abutment on the fixed member  56  is released and the catch is released. 
     Thereby, in the lock bar  33 , the bent portion  33   b  removes from the fixed member  56 , and locking of the UD bending operation knob  21  is released. At this time, the lock button  31  and the two lock bars  33  of the turn locking mechanism  30  also move in an outer periphery direction of the UD bending operation knob  21  by a biasing force of a coil spring  35 . Thereby, the UD bending operation knob  21  is brought into a state in which the UD bending operation knob  21  can perform a free turning operation without being fixed by the turn locking mechanism  30 . 
     From the above explanation, the configuration of the present modification is suitable for the reusable endoscope  1  because the fixed member  56  has durability, in addition to the aforementioned operational effects. 
     (Third Modification) 
     A present modification is configured to adopt a so-called knock type extension lock mechanism  70  in a turn locking mechanism  30 . 
     More specifically, the turn locking mechanism  30  has the knock type extension lock mechanism  70  besides the aforementioned lock button  31  and the like. The knock type extension lock mechanism  70  is configured by having a cylindrical exterior portion  71 , a knock rod  72 , a rotator  73 , a spring retainer  74  in a circular column shape, a coil spring  75 , and a bearing  76 . 
     The exterior portion  71  has an opening portion  71   a  at one end, and has grooves not illustrated formed on an inner peripheral surface. The knock rod  72  is accommodated in the exterior portion  71  so that a rod-shaped operation rod body  72   a  protrudes from the opening portion  71   a  of the exterior portion  71 . The knock rod  72  is operated so as to protrude and retract with respect to the exterior portion  71 . 
     The knock rod  72  has a plurality of projection portions  72   b  that rectilinearly move along the grooves (not illustrated) of the exterior portion  71 , on an outer peripheral portion, and a recessed and protruded portion  72   c  is formed on a surface on an opposite side to the operation rod body  72   a . Note that the knock rod  72  is connected to an end surface of the lock button  31  by, for example, being screwed into the end surface. 
     The rotator  73  has a rod body  73   a  that is inserted into the knock rod  72  to be turnably held. On an outer peripheral portion of the rotator  73 , cams  73   b  for abutting on the recessed and protruded portion  72   c  to rotate in response to protrusion and retraction of the knock rod  72  are formed. In other words, the cams  73   b  abut on the recessed and protruded portion  72   c  of the knock rod  72  and the rotator  73  is rotated around an axis. 
     In the spring retainer  74 , an outward flange  74   a  is formed in a middle of an outer peripheral portion. The outward flange  74   a  abuts on one end of the coil spring  75 , and receives a biasing force to one side. Note that the bearing  76  is connected to the opening portion of the exterior portion  71  by, for example, being screwed into the opening portion. 
     In other words, an operation shaft here is configured by the knock rod  72  that protrudes from the exterior portion  71  and is connected to the lock button  31  to the bearing  76  that closes the opening portion of the exterior portion  71 . 
     In the turn locking mechanism  30  having the knock type extension lock mechanism  70  configured like this, the knock rod  72  of the knock type extension lock mechanism  70  is pressed down when the lock button  31  is pushed in by the user, the rotator  73  turns in a predetermined direction, and the cam  73   b  gets caught on the protruded portion having a V-shaped end surface not illustrated and formed on the inner surface of the exterior portion  71  according to a turning position of the rotator  73 , as shown in a state in  FIG.  22    and a state in  FIG.  23   . 
     At this time, the knock type extension lock mechanism  70  is stopped in a state in which the rotator  73  presses the spring retainer  74  and compresses the coil spring  75 . Thereby, the lock button  31  is brought into a state in which a part of the knock rod  72  is buried with respect to the exterior portion  71 , and a state in which the lock button  31  is pushed in is held. The coil spring  75  generates a biasing force to bias the lock bar  33  in a radially outward direction, and the lock bar  33  engages the fixed member ( 51 ,  52 ,  56 ) with a friction force, and the friction force is larger than the biasing force. 
     Thereby, the lock bar  33  is fixed to fixed members ( 51 ,  52 ,  56 ) of the aforementioned embodiment and modifications by penetrating through the fixed members, or the like, and thereby the turning position of the UD bending operation knob  21  is brought into a locked state (see  FIG.  23   ). 
     When the lock button  31  is pushed in again by the user from the state in which a part of the knock rod  72  is buried with respect to the exterior portion  71 , in the turn locking mechanism  30 , the rotator  73  of the knock type extension lock mechanism  70  further turns in a predetermined direction, and the cam  73   b  removes from the V-shaped end surface (not illustrated) formed on the protruded portion of the exterior portion  71 . 
     At this time, the knock type extension lock mechanism  70  is brought into a state in which the rotator  73  receives the biasing force of the coil spring  75  via the spring retainer  74  and is returned and the knock rod  72  is protruded with respect to the exterior portion  71 . Thereby, the lock button  31  returns to an initial state shown in  FIG.  22   , fixation of the lock bar  33  by the fixed members ( 51 ,  52 ,  56 ) of the aforementioned embodiment and modifications is released, and the UD bending operation knob  21  is brought into a state in which the UD bending operation knob  21  can perform a free turning operation without being fixed by the turn locking mechanism  30 . 
     In this way, the endoscope  1  does not have to be provided with the lock release mechanism  40  in the UD bending operation knob  21 , by adopting the so-called knock type extension lock mechanism  70  in the turn locking mechanism  30 . 
     (Fourth Modification) 
     A present modification is another aspect of the fixed member of the turn locking mechanism  30 . Therefore, for the components already described in the above, the same reference signs are used, and detailed explanation of the components is omitted. 
     In an endoscope  1  of the present example, a rigid arc-shaped frame body  53  of metal, resin or the like is provided on a seat  16  formed to project on an outer surface side of an operation portion body  10 , similarly to the first modification, as shown in  FIG.  24   . In the frame body  53 , an opening portion  54  is formed. A mesh-like fixed member  77  is provided to close the opening portion  54  of the frame body  53 . The fixed member  77  includes a surface provided in a direction different from a rotation direction of the bending operation knob  21 , and the lock bar  33  engages the fixed member  77  by the lock bar  33  hooking on the surface. 
     The fixed member  77  is a wire net formed of metal, or a sheet-shaped mesh-like plate body formed of an elastic member such as rubber or a synthetic resin. The mesh-like fixed member  77  and the rigid frame body  53  are included in a turn locking mechanism  30 . When the lock button  31  is in the second position and the lock bar  33  engages the fixed member  77 , the pointed end portion  33   a  pierces a mesh of a surface of the wire net. 
     In the endoscope  1 , a lock button  31  of the turn locking mechanism  30  is pushed in, whereby a lock bar  33  moves forward, a pointed end portion  33   a  pierces a mesh of the fixed member  77 , and a UD bending operation knob  21  is locked. On the other hand, in the endoscope  1 , a release button  41  of a lock release mechanism  40  provided at an opposite side of a finger rest portion  23  is pushed in, whereby the lock bar  33  retracts, the pointed end portion  33   a  removes from the mesh of the fixed member  77 , and fixation of a turning position of the UD bending operation knob  21  is released. 
     With the configuration of the fixed member  77  like this, the endoscope  1  of the present modification can also lock and release the turning position of the UD bending operation knob  21 . 
     (Fifth Modification) 
     A present modification is another aspect of the fixed member and the lock bar  33  of the turn locking mechanism  30 . Therefore, for the components already described in the above, the same reference signs are used, and detailed explanation of the components is omitted. 
     In an endoscope  1  of the present example, a turn locking mechanism  30  is configured to have an annular fixed member  51 , and a crank-shaped lock bar  33 , as shown in  FIG.  25    to  FIG.  27   . The lock bar  33  is in a shape having a middle portion  33   c  in a U-shape that is folded upward seen toward the paper surface of the drawing and folded downward to a pointed end portion  33   a  side here so as not to interfere with the annular fixed member  51 . 
     In other words, by the middle portion  33   c , the lock bar  33  is disposed above the fixed member  51 , and can avoid interference with the fixed member  51  at a time of moving. 
     According to the configuration like this, in the endoscope  1 , it is possible to increase a turning operation angle of the UD bending operation knob  21  by making the fixed member  51  annular so that the lock bar  33  of the turn locking mechanism  30  does not interfere with the fixed member  51 . 
     Note that an active member of the endoscope  1  is not only the bending portion  7 , but the turn locking mechanism  30  and the lock release mechanism  40  may be provided at other endoscope functions than the bending portion  7 , for example, an operation knob that operates, and raises and lowers a treatment instrument raising base (forceps elevator) used in, for example, a side-viewing endoscope. 
     The disclosure described in the above embodiment and modifications is not limited to the embodiment and the modifications, but other than the embodiments and modifications, various modifications can be carried out within the range without departing from the gist of the disclosure in the implementation stage. Furthermore, in the above embodiment and modifications, the disclosures in the various stages are included, and various inventions can be extracted by appropriate combinations in the plurality of components that are disclosed. 
     For example, even if some components are deleted from all the components shown in the embodiment and modifications, the configuration from which the components are deleted can be extracted as the invention if the problem mentioned can be solved, and the effects mentioned are obtained. 
     (Example 1) An endoscope comprising: 
     an insertion portion; 
     an operation portion body provided connectively to the insertion portion; 
     a knob provided at the operation portion body by being axially supported by a rotation shaft, and configured to be operated to turn when operating an active member; and 
     a turning lock mechanism provided in the knob and configured to lock turning of the knob, 
     wherein the turning lock mechanism comprises 
     a lock button, 
     a lock bar connected to the lock button and extensively provided inside of the knob, and 
     a fixed member fixed to the operation portion body, and configured to be penetrated by the lock bar when the lock button is pushed in, so that turning of the knob is locked. 
     (Example 2) The endoscope according to Example 1, 
     wherein the lock bar comprises two lock bars, with the rotation shaft being interposed between the two lock bars, and 
     at least one of the two lock bars penetrates through the fixed member, so that turning of the knob is locked. 
     (Example 3) The endoscope according to Example 1, 
     wherein the lock bar includes a sharp pointed end portion at an extension end. 
     (Example 4) The endoscope according to Example 3, 
     wherein the fixed member includes an elastic body which the pointed end portion can pierce. 
     (Example 5) The endoscope according to Example 3, 
     wherein the fixed member includes 
     a frame body including an opening portion, and 
     a sheet of an elastic body that is provided to close the opening portion, and can be pierced by the pointed end portion. 
     (Example 6) The endoscope according to Example 1, 
     wherein the fixed member includes a plurality of protruded portions and recessed portions in a direction in which the knob turns, on one side of an opening portion, and 
     the lock bar is fitted in at least one of the recessed portions, so that the knob is locked. 
     (Example 7) The endoscope according to Example 6, 
     wherein the lock bar is an elastic body. 
     (Example 8) The endoscope according to Example 6, 
     wherein the lock bar includes a bent portion configured to abut and get caught on the fixed member, at an extension end. 
     (Example 9) The endoscope according to Example 1, comprising: 
     a lock release mechanism provided in the knob and configured to release locking of the knob, 
     wherein the lock release mechanism comprises 
     a release button provided at a symmetrical position of the lock button, and 
     a release bar connected to the release button, in which an end portion extensively provided inside of the knob is provided at a position facing an extension end of the lock bar. 
     (Example 10) The endoscope according to Example 1, 
     wherein the fixed member includes an abutment surface provided in a direction different from a direction in which the knob turns, and 
     the lock bar abuts on the abutment surface, so that turning of the knob is locked. 
     (Example 11) A method for locking a knob of an endoscope, 
     the endoscope comprising an insertion portion, an operation portion body provided connectively to the insertion portion, a knob provided at the operation portion body by being axially supported by a rotation shaft, and configured to be operated to turn when operating an active member, a lock button provided at the knob and configured to lock turning of the knob, a lock bar connected to the lock button and extensively provided inside of the knob, and a fixed member fixed to the operation portion body, 
     the method comprising: 
     pushing in the lock button; and 
     causing the lock bar to penetrate through the fixed member, so that turning of the knob is locked. 
     (Example 12) The method for locking the knob according to Example 11, 
     wherein the fixed member includes an abutment surface provided in a direction different from a direction in which the knob turns, and 
     the lock bar abuts on the abutment surface, so that turning of the knob is locked.