Endoscope having distal-end rigid portion with rotatable raising base

An endoscope includes: a distal-end rigid portion including an opening through which an instrument protrudes; a raising base disposed in the opening and configured to change a direction in which the instrument protrudes; a rotary shaft fixed to the raising base so as to rotate together with the raising base; an arm fixed to the rotary shaft so as to rotate the rotary shaft; a housing formed separately from the distal-end rigid portion, the housing including: a first bearing including a first shaft hole to rotatably support the rotary shaft; and a second bearing integrally formed with the first bearing and including a second shaft hole that is coaxially arranged with the first shaft hole so as to rotatably support the rotary shaft; and a seal member disposed between an outer circumference of the rotary shaft and an inner circumference of the first shaft hole to keep watertightness therebetween.

BACKGROUND

The present disclosure relates to an endoscope.

There are known endoscopes in which an instrument such as forceps may protrude from the distal end of an insertion unit inserted into a subject (see, for example, Japanese Laid-open Patent Publication No. 2016-131578). In this endoscope, an operation wire extending in the insertion unit is moved in accordance with the operation on an operating unit provided on the proximal end side of the insertion unit so that a rotary shaft rotates to raise an elevator. In the known endoscope, the rotary shaft is supported by a shaft hole of a housing disposed between the connection position of the wire and the elevator.

SUMMARY

According to one aspect of the present disclosure, there is provided an endoscope through which an instrument is insertable including: a distal-end rigid portion disposed at a distal end of the endoscope and including an opening through which the instrument protrudes; a raising base disposed in the opening and configured to be in contact with the instrument and change a direction in which the instrument protrudes; a rotary shaft having one end thereof fixed to the raising base so as to rotate together with the raising base; an arm fixed to the rotary shaft so as to rotate the rotary shaft in accordance with an operation on an operating unit; a housing formed separately from the distal-end rigid portion, the housing including: a first bearing located closer to the raising base than the arm in an axial direction of the rotary shaft and including a first shaft hole to rotatably support the rotary shaft; and a second bearing integrally formed with the first bearing and located on a side opposite to the first bearing with respect to the arm unit in the axial direction, the second bearing including a second shaft hole that is coaxially arranged with the first shaft hole so as to rotatably support the rotary shaft; and a seal member disposed between an outer circumference of the rotary shaft and an inner circumference of the first shaft hole to keep watertightness between the rotary shaft and the first shaft hole.

DETAILED DESCRIPTION

An embodiment of an endoscope is described below with reference to the drawings. The present disclosure is not limited to the embodiment. The present disclosure is applicable to typical endoscopes including a raising base.

In the description of the drawings, the identical or corresponding elements are denoted by the same reference numeral as appropriate. It should be noted that the drawings are schematic and the relationship between the elements in dimension, the ratio of the elements, and the like, are sometimes different from the reality. In the drawings, some of the elements may be different in the dimensional relationship or the ratio.

FIG.1is a schematic view illustrating a configuration of an endoscope1according to an embodiment. The endoscope1includes: an insertion unit2having an imaging unit installed at its distal end and inserted into the inside of the subject; an operating unit3continuously coupled to the proximal end side of the insertion unit2; a universal cord4extending from the side of the operating unit3; and a connector unit5continuously coupled to the universal cord4and coupled to an observation device that controls the endoscope1, a light source device that supplies illumination light to the endoscope1, and the like. In this description, as illustrated inFIG.1, the direction that is the longitudinal direction of the endoscope1and that is the insertion direction of the insertion unit2is referred to as an “insertion direction”, the distal end side (the upper side inFIG.1) in the insertion direction as the “distal end side”, and the proximal end side (the lower side inFIG.1) as the “proximal end side”.

The insertion unit2includes, sequentially from the distal end side, a distal end portion2a, a bendable portion2bthat is configured to bend in accordance with the operation of the operating unit3, and a flexible tube portion2chaving flexibility. The proximal end of the flexible tube portion2cis continuously coupled to the distal end side of the operating unit3. An ultrasound transducer2aais disposed at the distal end of the distal end portion2a. The endoscope1may be an endoscope including no ultrasound transducer.

The operating unit3includes a forceps insertion port3athrough which an instrument such as a forceps needle is inserted into the subject. A forceps insertion channel is provided inside the insertion unit2, and therefore the forceps insertion port3aserves as an insertion port of the forceps insertion channel. That is, the endoscope1is an endoscope through which an instrument is insertable. The operating unit3receives the operation for rotating a rotary shaft described later.

FIG.2is a schematic partial cross-sectional view of the distal end portion2aof the endoscope1illustrated inFIG.1.FIG.2illustrates the cross-section perpendicular to the insertion direction. As illustrated inFIG.2, the distal end portion2aof the endoscope1includes: a distal-end rigid portion11disposed at the distal end of the endoscope1and having an opening11aformed therein; a forceps elevator (raising base)12disposed in the opening11ato be in contact with the forceps and change the protruding direction of the forceps; a rotary shaft13having one end thereof fixed to the forceps elevator12so as to rotate together with the forceps elevator12around an axis A; and an arm unit14fixed to the rotary shaft13so as to rotate the rotary shaft13in accordance with the operation on the operating unit3; a housing15rotatably supporting the rotary shaft13; a rotary shaft seal17serving as a sealing member that keeps the watertightness between the rotary shaft13and the housing15; a housing seal18keeping the watertightness between the distal-end rigid portion11and the housing15; a forceps elevator seal (raising base seal)19keeping the watertightness between the forceps elevator12and the rotary shaft13; and a spring pin20fixing the rotary shaft13to the arm unit14.

The distal-end rigid portion11is made of, for example, a resin.

FIG.3is a side view of the forceps elevator12illustrated inFIG.2. As illustrated inFIG.3, the side surface of the forceps elevator12includes a shaft hole12ato be engaged with the rotary shaft13. The shaft hole12aincludes a planar portion12aaextending in the direction perpendicular to the axial direction (the axis A) of the rotary shaft13. The forceps elevator12includes a screw hole12bcommunicating with the shaft hole12a. With reference back toFIG.2, the outer circumference of the rotary shaft13includes an engagement groove13fto be engaged with the rotary shaft seal17. The forceps elevator12is made of a rigid material such as a metal, an alloy, or a ceramic.

FIG.4is a perspective view of the rotary shaft13illustrated inFIG.2. As illustrated inFIG.4, the rotary shaft13includes a planar portion13aextending in a direction perpendicular to the axial direction (the axis A) of the rotary shaft13and opposed to the planar portion12aaof the shaft hole12a. The planar portion13aincludes a groove13bin which the distal end of the screw engaged with the screw hole12bis positioned. The outer circumference of the rotary shaft13on the side opposite to the forceps elevator12includes a planar portion13cextending in the direction perpendicular to the axial direction (the axis A). A pin hole13dinto which the spring pin20is inserted is formed inside the planar portion13c. A through-hole13eis formed inside the rotary shaft13so as to check the watertightness between the forceps elevator12and the rotary shaft13. Specifically, the watertightness between the forceps elevator12and the rotary shaft13may be checked depending on the escape of gas when the gas is introduced through the through-hole13efrom the side opposite to the forceps elevator12while the contact part between the forceps elevator12and the forceps elevator seal19is immersed in liquid. The rotary shaft13is made of, for example, a metal or an alloy. It is preferable that coating is applied to the surface of the rotary shaft13so as to improve the sliding performance. Specifically, coating such as DLC (Diamond-Like Carbon), fluorine, or plating is applied to the surface of the rotary shaft13. In the endoscope1, the rotary shaft13slides relative to the rotary shaft seal17; however, when the housing15slides relative to the rotary shaft seal17, it is preferable to apply the above-described coating to the surface of the housing15.

FIG.5is a perspective view of the arm unit14illustrated inFIG.2. As illustrated inFIG.5, the arm unit14includes a through-hole14athrough which the rotary shaft13is inserted. The through-hole14aincludes a planar portion14aaextending in the direction perpendicular to the axial direction (the axis A) and opposed to the planar portion13cof the rotary shaft13. In the assembled endoscope1, the through-hole14ais engaged with the rotary shaft13in a state where the planar portion14aaof the through-hole14ais opposed to the planar portion13cof the rotary shaft13. The arm unit14includes a pin hole14bthrough which the spring pin20is inserted. The through-hole14ais engaged with the rotary shaft13and the spring pin20is inserted into the pin hole13dand the pin hole14bso that the rotary shaft13and the arm unit14may rotate together. The arm unit14includes a wire engagement portion14cthat engages with a cylindrical wire distal end portion16aformed at the distal end of a forceps operation wire16. Furthermore, the arm unit14includes a slit14dcommunicating with the wire engagement portion14cso as to insert the wire distal end portion16ainto the wire engagement portion14c. The slit14dis formed at such a position that the wire distal end portion16ais insertable from above inFIG.5in a state where the forceps operation wire16is located closest to the proximal end side (a state where the forceps elevator12is elevated). As a result, as the part receiving a force applied to the arm unit14via the forceps operation wire16has a large area, it is possible to prevent the deformation of the arm unit14. The outer peripheries of the through-holes14aon both side surfaces of the arm unit14include stepped portions14e(seeFIG.2andFIG.5). The formation of the stepped portions14eprevents the displacement of the arm unit14in the axial direction (the axis A) with respect to the housing15. As a result, the forceps elevator12is prevented from moving in the axial direction (the axis A) and the forceps elevator12is allowed to be elevated right above with accuracy, whereby it is possible to prevent the forceps elevator12from being in contact with the wall surface of the distal-end rigid portion11, maintain a certain clearance between the wall surface of the distal-end rigid portion11and the forceps elevator12, and ensure the cleanability. Moreover, the formation of the stepped portions14emay reduce the contact area between the arm unit14and the housing15and decrease the frictional resistance between the arm unit14and the housing15. The arm unit14is made of, for example, a metal or an alloy.

FIG.6is a perspective view of the housing15illustrated inFIG.2. As illustrated inFIG.6, the housing15includes: a first bearing portion15athat is located closer to the forceps elevator12than the arm unit14in the axial direction (the axis A) of the rotary shaft13; and a second bearing portion15bthat is located on the side opposite to the first bearing portion15awith respect to the arm unit14in the axial direction (the axis A). The housing15is made of, for example, a metal or an alloy and has the first bearing portion15aand the second bearing portion15bintegrally formed. The first bearing portion15aincludes a first shaft hole15aathat rotatably supports the rotary shaft13. The second bearing portion15bincludes a second shaft hole15bathat is coaxially arranged with the first shaft hole15aaand rotatably supports the rotary shaft13. The second bearing portion15bincludes a screw hole15bband a screw hole15bcused to fix the housing15to the distal-end rigid portion11.

With reference back toFIG.2, the forceps operation wire16extends toward the proximal end side and moves in the insertion direction in accordance with the operation on the operating unit3so as to rotate the forceps elevator12via the arm unit14and the rotary shaft13.

The rotary shaft seal17is disposed between the engagement groove13fpositioned on the outer circumference of the rotary shaft13and the inner circumference of the first shaft hole15aaof the first bearing portion15a. The rotary shaft seal17is made of a material having elasticity, such as rubber or silicone.

The housing seal18is disposed between a groove15abformed in the first bearing portion15aand the distal-end rigid portion11. The housing seal18is made of a material having elasticity, such as rubber or silicone.

The forceps elevator seal19is disposed between a groove13gformed on the outer circumference of the rotary shaft13and the forceps elevator12. The forceps elevator seal19is made of a material having elasticity, such as rubber or silicone.

Next, the method for assembling the endoscope1is described.FIGS.7to13are diagrams illustrating the method for assembling the endoscope1. First, as illustrated inFIG.7, the arm unit14is disposed between the first bearing portion15aand the second bearing portion15bof the housing15. Then, the rotary shaft13is engaged with the through-hole14aof the arm unit14and the second shaft hole15baof the second bearing portion15bvia the first shaft hole15aaof the first bearing portion15asuch that the planar portion14aaof the arm unit14is opposed to the planar portion13cof the rotary shaft13. Then, the spring pin20is inserted into the pin hole14bof the arm unit14and the pin hole13dof the rotary shaft13. Accordingly, a raising base unit illustrated inFIG.8is assembled. In this state, as the rotation axis of the forceps elevator12, the rotation axis of the arm unit14, and the axis centers of the first shaft hole15aaand the second shaft hole15baare in the identical straight line, there is no need for alignment.

Subsequently, as illustrated inFIG.9, a base21is fitted into an opening11bof the distal-end rigid portion11. The base21is made of a metal or an alloy and is a base for attaching the raising base unit illustrated inFIG.8. A pin22is inserted into a pin hole21aof the base21through a pin hole11cof the distal-end rigid portion11. The base21is attached to the distal-end rigid portion11with an adhesive, or the like. The base21includes a screw hole21band a screw hole21c.

Then, as illustrated inFIG.10, in a state where the forceps elevator12is disposed in the opening11aof the distal-end rigid portion11, the raising base unit illustrated inFIG.8is inserted into the opening11bof the distal-end rigid portion11. Here, the outer circumference of the first shaft hole15aaof the first bearing portion15ais engaged with a through-hole11dof the distal-end rigid portion11. The rotary shaft13is inserted into the shaft hole12aof the forceps elevator12. A screw25is fitted into the screw hole21bof the base21via the screw hole15bcof the second bearing portion15b. The wire distal end portion16aof the forceps operation wire16is assembled with the wire engagement portion14cof the arm unit14via the slit14d.

FIG.11is a cross-sectional view along the axis A that is the rotation axis of the rotary shaft13. As illustrated inFIG.11, a screw23is fitted into the screw hole12bof the forceps elevator12in a state where the rotary shaft13is inserted into the through-hole11dof the distal-end rigid portion11. Accordingly, the forceps elevator12and the rotary shaft13are fixed to each other. A groove12cof the forceps elevator12is sealed by a screw concealing member24to which an adhesive is applied.

Finally, as illustrated inFIG.12, a cover26is bonded with an adhesive, or the like, so as to cover a stepped portion11eof the distal-end rigid portion11, and a screw27is fitted into the screw hole21cvia a hole26aand the screw hole15bb. Accordingly, the watertightness of the space closer to the cover26with respect to the rotary shaft seal17is maintained. Furthermore, a lid28is bonded over the cover26with an adhesive. As a result, the distal end portion of the endoscope1illustrated inFIG.13is assembled.

As described above, according to the embodiment, as the two sides of the rotary shaft13are supported by the first shaft hole15aaand the second shaft hole15ba, respectively, the inclination of the rotary shaft13rotating the forceps elevator12is prevented. Accordingly, even if the operation for elevating the forceps elevator12is repeated, it is possible to keep the watertight condition and to prevent the occurrence of an improper rotation.

When the rotary shaft is supported only on the side of the forceps elevator as in Japanese Patent Laid-Open No. 2016-131578, there is a possibility that the rotary shaft is inclined by the degree corresponding to the clearance between the rotary shaft and the housing with regard to the thickness of the portion supporting the rotary shaft. On the other hand, in the endoscope1, there is a possibility that the rotary shaft13is inclined by the degree corresponding to the clearance between the rotary shaft13and the housing15with regard to the distance from the end surface of the first shaft hole15aaon the side of the forceps elevator12to the end surface of the second shaft hole15baon the side opposite to the forceps elevator12. Specifically, in the endoscope1, the inclination caused due to the clearance between the rotary shaft13and the housing15is received in the distance from the end surface of the first shaft hole15aaon the side of the forceps elevator12to the end surface of the second shaft hole15baon the side opposite to the forceps elevator12, and therefore the rotary shaft13is inclined by a small degree. As a result, it is highly effective in keeping the watertight condition and preventing the occurrence of an improper rotation.

FIG.14is a diagram illustrating a configuration of a part of a distal end portion of an endoscope according to a modification1of the embodiment. As illustrated in FIG.14, a rotary shaft13A includes a screw hole13Ad, and an arm unit14A includes a screw hole14Ab. A pin screw20A is fitted into the screw hole13Ad and the screw hole14Ab. As described here, a screw may be used instead of a spring pin. The central portion of the pin screw20A in the longitudinal direction is provided with a recessed portion to check the watertightness between the forceps elevator and the rotary shaft13A. The formation of the recessed portion allows the gas introduced through the through-hole formed inside the rotary shaft13A on the side opposite to the forceps elevator to move toward the forceps elevator.

FIG.15is a diagram illustrating a configuration of a part of a distal end portion of an endoscope according to a modification2of the embodiment. As illustrated inFIG.15, a rotary shaft13B is pressed into a through-hole14Ba of an arm unit14B. As described above, the method for fixing the arm unit and the rotary shaft is not particularly limited. Also, the method for fixing the rotary shaft and the forceps elevator is not particularly limited.

In the description according to the above-described embodiment, the distal-end rigid portion11is made of a resin; however, the distal-end rigid portion11may be made of a metal or an alloy. When the distal-end rigid portion11is made of a metal or an alloy, the housing15may be directly fixed to the distal-end rigid portion11with a screw, or the like, without the base21.

Other advantages and modifications may be easily derived by those skilled in the art. Therefore, broader aspects of the present disclosure are not limited to the specific details and the representative embodiments described and illustrated above. Thus, various modifications are possible without departing from the spirit or the scope of general ideas of the present disclosure as defined by the appended claims and their equivalents.

According to the present disclosure, it is possible to achieve an endoscope in which it is possible to prevent the inclination of a rotary shaft for elevating an elevator.