Title:
CONTROLLABLY BENDABLE TUBE OF AN ENDOSCOPE
United States Patent 3799151
Abstract:
A controllably bendable tube section of an endoscope is connected between the distal end casing and the yieldably flexible main tube of the endoscope. Two pairs of wires extend through the controllably bendable tube section and the flexible tube, the wires in each pair being located at diametrically opposite sides of the tubes, their distal ends being secured to the end casing. The proximal ends of the pairs of wires are connected respectively to two control mechanisms provided in the control housing of the endoscope, so that the wires in each pair can be alternately tensioned by operating the associated control mechanism. A first pair of non-contractable sheaths slidably surrounds the respective wires of one pair, the distal ends of the flexible sheaths being secured to the distal end of the flexible tube and their proximal ends being secured to respective stationary portions of the control housing, whereby the controllably bendable tube section may be bent in its entire length by the operation of the one control mechanism regardless of the flexure of the flexible tube. A second pair of non-contractable sheaths slidably surrounds the respective wires of the other pair, and the distal ends of the second set of flexible sheaths are secured to a longitudinally intermediate part of the controllably bendable tube section while the proximal ends are secured to respective stationary portions of the control housing, whereby only the distal portion of the controllably bendable tube may be bent by the operation of the other control mechanism.
US Patent References:
Flexible tube assembly
Ashizawa et al. - May 1966 - 3253524
/3572325.html
Bazell et al. - March 1971 - 3572325
Bidirectionally flexible segmented tube
Ulrich - January 1963 - 3071161
/3605725.html
Bentov - September 1971 - 3605725
Flexible tube assembly
Ashizawa et al. - May 1966 - 3253524
/3572325.html
Bazell et al. - March 1971 - 3572325
Bidirectionally flexible segmented tube
Ulrich - January 1963 - 3071161
/3605725.html
Bentov - September 1971 - 3605725
Inventors:
Fukaumi, Masaharu (Yokohama, JA)
Mori, Toshiyuki (Tokyo, JA)
Mori, Toshiyuki (Tokyo, JA)
Application Number:
05/208212
Publication Date:
03/26/1974
Filing Date:
12/15/1971
View Patent Images:
Export Citation:
Assignee:
Olympus Optical Co., Ltd. (Tokyo, JA)
Primary Class:
Other Classes:
600/149
International Classes:
A61B1/005; A61M25/01; A61B1/06
Field of Search:
128/4,6,7,8,2M
Primary Examiner:
Laudenslager, Lucie H.
Claims:
We claim
1. In an elongated endoscope having a longitudinal axis and including, in axial sequence, a distal end casing, a bendable tube section, a flexible main tube, and a control housing at the proximal end of the endoscope, the endoscope further having bending means for bending said section, said bending means including a plurality of wire members extending from said control housing through said main tube in a distal direction toward said end casing, and control means connected to the proximal ends of said wire members for selectively tensioning said wire members, the improvement in said bending means which comprises:
2. In an endoscope as set forth in claim 1, said bendable tube section having two terminal, axial portions offset from said intermediate portion in a distal and a proximal direction respectively, each of said axial portions including a plurality of annular segments, pivot means connecting the segments of said portion offset in said distal direction for relative angular movement in each of two axial planes transversely intersecting each other, and further pivot means connecting the segments of said portion offset in said proximal directions for relative angular movement in only one of said axial planes, said enveloped wire members being fastened to said end casing in said planes respectively.
3. In an endoscope as set forth in claim 2, the distal ends of said first and second sheaths being fastened respectively to said terminal distal portion of said main tube and to said intermediate portion of said section in said planes respectively.
4. In an endoscope as set forth in claim 3, third and fourth elongated tubular sheaths of fixed length movably enveloping respective third and fourth wire members of said plurality of wire members and having respective distal and proximal longitudinal ends, the distal end of said third sheath being fastened to said distal portion of said main tube in the same axial plane as the distal end of said first sheath, the distal ends of said first and third sheaths being oppositely spaced from said axis, the distal end of said fourth sheath being fastened to said intermediate portion of said section in the same axial plane as the distal end of said second sheath, the distal ends of said second and fourth sheaths being oppositely spaced from said axis, the third and fourth wire members being fastened to said end casing in respective common axial planes with the wire members enveloped by said first and second sheaths respectively.
1. In an elongated endoscope having a longitudinal axis and including, in axial sequence, a distal end casing, a bendable tube section, a flexible main tube, and a control housing at the proximal end of the endoscope, the endoscope further having bending means for bending said section, said bending means including a plurality of wire members extending from said control housing through said main tube in a distal direction toward said end casing, and control means connected to the proximal ends of said wire members for selectively tensioning said wire members, the improvement in said bending means which comprises:
2. In an endoscope as set forth in claim 1, said bendable tube section having two terminal, axial portions offset from said intermediate portion in a distal and a proximal direction respectively, each of said axial portions including a plurality of annular segments, pivot means connecting the segments of said portion offset in said distal direction for relative angular movement in each of two axial planes transversely intersecting each other, and further pivot means connecting the segments of said portion offset in said proximal directions for relative angular movement in only one of said axial planes, said enveloped wire members being fastened to said end casing in said planes respectively.
3. In an endoscope as set forth in claim 2, the distal ends of said first and second sheaths being fastened respectively to said terminal distal portion of said main tube and to said intermediate portion of said section in said planes respectively.
4. In an endoscope as set forth in claim 3, third and fourth elongated tubular sheaths of fixed length movably enveloping respective third and fourth wire members of said plurality of wire members and having respective distal and proximal longitudinal ends, the distal end of said third sheath being fastened to said distal portion of said main tube in the same axial plane as the distal end of said first sheath, the distal ends of said first and third sheaths being oppositely spaced from said axis, the distal end of said fourth sheath being fastened to said intermediate portion of said section in the same axial plane as the distal end of said second sheath, the distal ends of said second and fourth sheaths being oppositely spaced from said axis, the third and fourth wire members being fastened to said end casing in respective common axial planes with the wire members enveloped by said first and second sheaths respectively.
Description:
BACKGROUND OF THE INVENTION
The present invention relates to a controllably bendable tube of an endoscope and, more particularly, to a controllably bendable tube of an endoscope capable of being controllably bent in a relatively low curvature in its entire length while it can be selectively bent in a relatively high curvature in a limited range in its entire length so as to facilitate the insertion of the forward end casing of the endoscope through a narrow passage having various curvatures.
In an endoscope for inspecting a hollow portion in a living body, for example, by inserting the forward end casing of the endoscope through a narrow passage having various curvatures, the control of the curvature of the controllably bendable tube of the endoscope is essential in order to smoothly insert the forward end casing through the narrow passage without giving substantial troubles to the living body to be inspected, and it is not sufficient for smoothly inserting the forward end casing through the narrow passage that the controllably bendable tube can merely be bent in a uniform curvature.
Therefore, a controllably bendable tube of an endoscope has been desired which is capable of being controllably bent in various curvatures in the selected portion of the bendable tube under particular conditions of the living body. However, no such a bendable tube has been developed.
The present invention aims at solving the above described problem.
SUMMARY OF THE INVENTION
An object of the present invention is, therefore, to provide a novel and useful controllably bendable tube of an endoscope capable of being controllably bent in its entire length while it is selectively bent in a limited range of its entire length so as to facilitate the insertion of the forward end casing of the endoscope through a narrow passage having various curvatures.
The above object is achieved in accordance with the present invention by the provision of a controllably bendable tube of an endoscope having a forward end casing, a control housing and an elongated yieldably flexible tube, the flexible tube being connected at its rearward end to the control housing while the forward end thereof is connected to the forward end casing through the controllably bendable tube, at least one wire extending through the controllably bendable tube and the flexible tube with its forward end secured to the forward end casing while the rearward end is connected to a control mechanism provided in the control housing, a non-contractable tube slidably surrounding the wire with its forward end secured to the forward end of the flexible tube while the rearward end is secured to a stationary portion of the control housing thereby permitting the entire length of the controllably bendable tube to be bent by the tensioning of the wire by the operation of the control mechanism regardless of the flexure of the flexible tube, the controllably bendable tube being characterized by the provision of another at least one wire extending through the controllably bendable tube and the flexible tube with its forward end secured to the forward end casing while the rearward end is connected to another control mechanism provided in the control housing and another non-contractable tube slidably surrounding the another wire with its forward end secured to a portion intermediate the entire length of the controllably bendable tube while the rearward end is secured to a stationary portion of the control housing thereby permitting the portion of the controllably bendable tube between the forward end thereof and the portion to which the forward end of the another non-contractable tube is secured to be selectively bent by tensioning the another wire by the operation of the another control mechanism.
By the controllably bendable tube of the present invention constructed as described above, the forward end casing of the endoscope can be inserted smoothly through a narrow passage having various curvatures by selectively operating either of the control mechanisms.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general side view showing an endoscope incorporating the controllably bendable tube of the present invention;
FIG. 2 is a schematic perspective view showing the elements constructing the first embodiments of the controllably bendable tube of the present invention;
FIGS. 3 and 4 are schematic views showing the manner how the controllably bendable tube of FIG. 2 is selectively bent in different curvatures;
FIG. 5 is a schematic side view partly in section showing the second embodiment of the controllably bendable tube of the present invention; and
FIGS. 6 and 7 are schematic views showing how the controllably bendable tube of FIG. 5 is selectively bent in different curvatures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the endoscope comprises a forward or distal end casing 1 adapted to be inserted into a hollow portion to be inspected, a controllably bendable tube section 2 connected at its forward or distal end to the rearward or proximal end of the forward end casing 1, an elongated, yieldably flexible main tube 3 connected at its forward or distal end to the rearward end of the controllably bendable section 2, and a control housing C connected to the rearward or proximal end of the flexible tube 3. The control housing C is provided with a first and a second control mechanisms having respectively control knobs H 1 , H 2 which are manually actuated by the operator so as to operate the respective control mechanisms. The control housing C is provided with an eyepiece E which may be replaced by a single lens reflex camera. An objective lens (not shown in FIG. 1) is provided in the forward end casing 1 and an image transmitting fiber optical system (also not shown in FIG. 1) extends through the controllably bendable tube section 2 and the flexible tube 3, so that an image of the object formed by the objective lens onto the forward end of the image transmitting fiber optical system is transmitted therethrough to the rearward end thereby permitting the thus transmitted image to be viewed or photographed by the eyepiece E or the reflex camera. An elongated illuminating light conducting fiber optical system I extends through the controllably bendable tube section 2, the flexible tube 3 and the control housing C with its rearward end extending outwardly from the control housing C so as to be supplied with an illuminating light from an external light source (not shown) while the forward end terminates at the forward end casing 1 so that the light transmitted through the light conducting fiber optical system I to the forward end thereof emanates therefrom to illuminate the object to be inspected.
First and second sets of tensioning wires extend through the controllably bendable tube section 2 and the flexible tube 3 with their rearward ends connected to the first and the second control mechanism, respectively, while their forward ends are secured to the forward end casing 1, so that the controllably bendable tube section 2 is controllably bent by selectively tensioning the wires by the operation of the control mechanism as described in detail hereinbelow.
FIG. 2 shows a first embodiment of the controllably bendable tube section of the present invention. In FIG. 2, the objective lens is designated by the reference numeral 4 and the forward end of the light conducting fiber optical system is designated by the reference numeral 5, while the image-transmitting fiber optical system is omitted for the clear showing of the construction of the controllably bendable tube section 2.
The controllably bendable tube section 2 shown in FIG. 2 consists of a forward or distal portion 2a and a rearward or proximal portion 2b connected to each other.
The forward portion 2a comprises a plurality of annular segments 6, 7, 9, 11, 13, 15, 16, 17 and 18. The segment 6 is secured to the rearward end of the forward end casing 1 at its forward end and it is provided with a pair of diametrically opposite pivoting portions 6a, 6a at its rearward end which are located in the horizontal diameter at the rearward end. The segment 7 has a pair of diametrically opposite pivoting portions 7a, 7a located in the horizontal diameter at its forward end and a pair of diametrically opposite pivoting portions 7b, 7b located in the vertical diameter at its forward end. The pivoting portions 6a of the segment 6 is pivotally connected to the pivoting portions 7a of the segment 7 by means of pins 8, respectively, so that the segment 6 is swingable in the vertical direction relative to the segment 7. The segment 9 has a pair of diametrically opposite pivoting portions 9a, 9a located in the vertical diameter at its forward end and a pair of diametrically opposite pivoting portions 9b, 9b located in the horizontal diameter at its rearward end. The pivoting portions 7b, 7b of the segment 7 are pivotally connected to the pivoting portions 9a, 9a of the segment 9 by means of pins 10, respectively, so that the segment 7 is swingable in the horizontal direction relative to the segment 9. The segment 11 has a pair of diametrically opposite pivoting portions 11a, 11a located in the horizontal diameter at its forward end while it has a pair of diametrically opposite pivoting portions 11b, 11b located in the horizontal diameter at its rearward end. The pivoting portions 9b, 9b of the segment 9 are pivotally connected to the pivoting portions 11a, 11a by means of pins 14, respectively, so that the segment 9 is swingable in the vertical direction relative to the segment 11. The segments 13, 15 and 16 are similar to the segments 7, 9 and 11, respectively, and they are pivotally connected to the adjacent segments in like manner as described above. The segments 17 and 18 are also similar to the segments 7 and 9, respectively, and they are pivotally connected to the adjacent segments, respectively. Thus, the forward portion 2a can be bent in either of the horizontal and vertical planes passing through the axis of the forward portion 2a.
The number of the segments of the forward portion 2a is not limited to that shown in FIG. 2, but may be varied according to the requirements in design. Further the segments 11, 16 may be omitted under the particular requirements in design.
The rearward portion 2b comprises a plurality of segments 19, 20, 21, 22, 23 which are similar to the segments 11, 16 of the forward portion 2a and a segment 24 having a pair of diametrically opposite pivoting portions located in the horizontal diameter at its forward end. The segments 19, 20 -- 24 are swingably connected to the adjacent segments, respectively, and the rearward end of the segment 24 is secured to the forward end of the flexible tube 3. Thus, the rearward portion 2b is bendable in the vertical plane. The number of the segments in the rearward portion 2b is not limited to that shown in the drawing.
A pair of wires 26a, 26b extend through the controllably bendable tube section 2 and the flexible main tube 3 in the diametrically opposite sides thereof in the vertical plane passing through the axis of the tubes 2 and 3 and the forward ends 26'a, 26'b of the wires 26a, 26b are secured to diametrically opposite portions of the casing 1 while the rearward ends are connected to the first control mechanism represented in FIG. 1 by the knob H 1 so that the wires may be alternately tensioned by the operation of the knob H 1 . Flexible tubes or sheaths 27a, 27b of fixed length, such as closely wound coils, slidably surround the respective wires 26a, 26b and the forward or distal ends 27'a, 27'b of the tubes 27a, 27b are secured to diametrically opposite, distal, terminal portions of the flexible main tube 3 while the rearward ends are secured to stationary portions of the control housing C in a manner indicated in FIG. 1 for sheath 27a only. Thus, the movement of either of the wires 26a, 26b given in the control housing C by the operation of the control mechanism is exactly transmitted to the portion of the wire 26a or 26b at the forward end 27'a or 27'b of the non-contractable flexible tube 27a or 27b, thereby permitting the entire length of the controllably bendable tube 2 to be controllably bent in the vertical plane passing through the axis of the tube 2 by the operation of the knob H 1 regardless of the flexure of the flexible tube 3.
In accordance with the present invention, another pair of wires 24a, 24b extend through the controllably bendable tube 2 section and the flexible main tube 3 at diametrically opposite sides thereof in the horizontal plane passing through the axis of the tubes 2 and 3 and the forward ends 24'a, 24'b of the wires 24a, 24b are secured to diametrically opposite portions of the forward end casing 1 while the rearward ends of the wires 24a, 24b are connected to the second control mechanism represented in FIG. 1 by the knob H 2 so as to be alternately tensioned thereby. A pair of flexible tubes or sheaths 25a, 25b of fixed length slidably surround the respective wires 24a, 24b and the forward ends 25'a, 25'b of the tubes 25a, 25b are secured in diametrically opposite relationship to the inner wall of the segment 19, which is approximately at the longitudinal mid-point of the section 2, while the rearward ends are secured to stationary portions of the control housing C so that the movement given to the wire 24a or 24b in the control housing C by the operation of the knob H 2 is exactly transmitted to the portion of the wire 24a or 24b at the forward end of the tube 25a or 25b. Thus, when the knob H 2 is operated, either of the wire 24a or 24b is tensioned so as to bend the forward portion 2a of the controllably bendable tube 2 in the horizontal plane passing through the axis of the tube 2.
Therefore, the controllably bendable tube 2 can be bent in its entire length by the operation of the knob H 1 while only a limited range, i.e., the forward portion 2a of the tube 2 can be bent by the operation of the knob H 2 , thereby permitting the tube 2 to be bent in various curvatures by selectively operating the knobs H 1 and H 2 . FIG. 3 shows the bent state of the tube 2 when the knob H 1 is actuated while FIG. 4 shows the bent state when the knob H 2 is actuated.
FIG. 5 shows a second embodiment of the present invention. In FIG. 5, a portion of the image transmitting fiber optical system is shown as designated by the reference numeral 106. In this embodiment, the foremost segment 109a and the rearmost segment 109b of the controllably bendable tube section 2' are similar in construction to the segments 6 and 24 shown in FIG. 2, respectively, but all the remaining segments 107 are similar to the segment 11 shown in FIG. 2, and the segments are swingably connected to each other at the mating pivoting portions 107a, 107b by means of pins 108 so that the entire length of the controllably bendable tube section 2' is bent in the plane of FIG. 5. A pair of wires 110a, 110b and a pair of flexible tubes 112a, 112b of fixed length are arranged in like manner as the wires 26a, 26b and tubes 27a, 27b shown in FIG. 2. In the embodiment of FIG. 5, however, a pair of wires 111a, 111b extend in the diametrically opposite sides of the tube 2' closely adjacent to the wires 110a, 110b, respectively, and flexible tubes of fixed length 113a, 113b slidably surround the respective wires 111a, 111b and the forward ends 113'a, 113'b are secured to the inner wall of the segments 107' arranged in about the center of the length of the tube section 2' as shown, while the rearward ends are connected to the second control mechanism represented in FIG. 1 by the knob H 2 instead of the wires 24a, 24b of FIG. 2 so that the wire 111a or 111b is selectively tensioned by the operation of the knob H 2 . The portion of the tube section 2' between the segment 107a and the segment 107' forms the forward portion 2'a.
In operation, when the knob H 1 is operated, the entire length of the tube section 2' is bent in the plane of FIG. 5 while only the forward portion 2'a is bent in the plane of FIG. 5 when the knob H 2 is operated. Thus, the controllably bendable tube section of FIG. 5 is bent in various curvatures by the selective operation of the knobs H 1 and H 2 .
FIG. 6 shows the bent state of the tube section 2' when the knob H 1 is actuated while FIG. 7 shows the bent state when the knob H 2 is actuated.
The embodiments shown in the drawings are front viewing endoscopes. However, the present invention is also applicable to a side viewing endoscope.
The present invention relates to a controllably bendable tube of an endoscope and, more particularly, to a controllably bendable tube of an endoscope capable of being controllably bent in a relatively low curvature in its entire length while it can be selectively bent in a relatively high curvature in a limited range in its entire length so as to facilitate the insertion of the forward end casing of the endoscope through a narrow passage having various curvatures.
In an endoscope for inspecting a hollow portion in a living body, for example, by inserting the forward end casing of the endoscope through a narrow passage having various curvatures, the control of the curvature of the controllably bendable tube of the endoscope is essential in order to smoothly insert the forward end casing through the narrow passage without giving substantial troubles to the living body to be inspected, and it is not sufficient for smoothly inserting the forward end casing through the narrow passage that the controllably bendable tube can merely be bent in a uniform curvature.
Therefore, a controllably bendable tube of an endoscope has been desired which is capable of being controllably bent in various curvatures in the selected portion of the bendable tube under particular conditions of the living body. However, no such a bendable tube has been developed.
The present invention aims at solving the above described problem.
SUMMARY OF THE INVENTION
An object of the present invention is, therefore, to provide a novel and useful controllably bendable tube of an endoscope capable of being controllably bent in its entire length while it is selectively bent in a limited range of its entire length so as to facilitate the insertion of the forward end casing of the endoscope through a narrow passage having various curvatures.
The above object is achieved in accordance with the present invention by the provision of a controllably bendable tube of an endoscope having a forward end casing, a control housing and an elongated yieldably flexible tube, the flexible tube being connected at its rearward end to the control housing while the forward end thereof is connected to the forward end casing through the controllably bendable tube, at least one wire extending through the controllably bendable tube and the flexible tube with its forward end secured to the forward end casing while the rearward end is connected to a control mechanism provided in the control housing, a non-contractable tube slidably surrounding the wire with its forward end secured to the forward end of the flexible tube while the rearward end is secured to a stationary portion of the control housing thereby permitting the entire length of the controllably bendable tube to be bent by the tensioning of the wire by the operation of the control mechanism regardless of the flexure of the flexible tube, the controllably bendable tube being characterized by the provision of another at least one wire extending through the controllably bendable tube and the flexible tube with its forward end secured to the forward end casing while the rearward end is connected to another control mechanism provided in the control housing and another non-contractable tube slidably surrounding the another wire with its forward end secured to a portion intermediate the entire length of the controllably bendable tube while the rearward end is secured to a stationary portion of the control housing thereby permitting the portion of the controllably bendable tube between the forward end thereof and the portion to which the forward end of the another non-contractable tube is secured to be selectively bent by tensioning the another wire by the operation of the another control mechanism.
By the controllably bendable tube of the present invention constructed as described above, the forward end casing of the endoscope can be inserted smoothly through a narrow passage having various curvatures by selectively operating either of the control mechanisms.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general side view showing an endoscope incorporating the controllably bendable tube of the present invention;
FIG. 2 is a schematic perspective view showing the elements constructing the first embodiments of the controllably bendable tube of the present invention;
FIGS. 3 and 4 are schematic views showing the manner how the controllably bendable tube of FIG. 2 is selectively bent in different curvatures;
FIG. 5 is a schematic side view partly in section showing the second embodiment of the controllably bendable tube of the present invention; and
FIGS. 6 and 7 are schematic views showing how the controllably bendable tube of FIG. 5 is selectively bent in different curvatures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the endoscope comprises a forward or distal end casing 1 adapted to be inserted into a hollow portion to be inspected, a controllably bendable tube section 2 connected at its forward or distal end to the rearward or proximal end of the forward end casing 1, an elongated, yieldably flexible main tube 3 connected at its forward or distal end to the rearward end of the controllably bendable section 2, and a control housing C connected to the rearward or proximal end of the flexible tube 3. The control housing C is provided with a first and a second control mechanisms having respectively control knobs H 1 , H 2 which are manually actuated by the operator so as to operate the respective control mechanisms. The control housing C is provided with an eyepiece E which may be replaced by a single lens reflex camera. An objective lens (not shown in FIG. 1) is provided in the forward end casing 1 and an image transmitting fiber optical system (also not shown in FIG. 1) extends through the controllably bendable tube section 2 and the flexible tube 3, so that an image of the object formed by the objective lens onto the forward end of the image transmitting fiber optical system is transmitted therethrough to the rearward end thereby permitting the thus transmitted image to be viewed or photographed by the eyepiece E or the reflex camera. An elongated illuminating light conducting fiber optical system I extends through the controllably bendable tube section 2, the flexible tube 3 and the control housing C with its rearward end extending outwardly from the control housing C so as to be supplied with an illuminating light from an external light source (not shown) while the forward end terminates at the forward end casing 1 so that the light transmitted through the light conducting fiber optical system I to the forward end thereof emanates therefrom to illuminate the object to be inspected.
First and second sets of tensioning wires extend through the controllably bendable tube section 2 and the flexible tube 3 with their rearward ends connected to the first and the second control mechanism, respectively, while their forward ends are secured to the forward end casing 1, so that the controllably bendable tube section 2 is controllably bent by selectively tensioning the wires by the operation of the control mechanism as described in detail hereinbelow.
FIG. 2 shows a first embodiment of the controllably bendable tube section of the present invention. In FIG. 2, the objective lens is designated by the reference numeral 4 and the forward end of the light conducting fiber optical system is designated by the reference numeral 5, while the image-transmitting fiber optical system is omitted for the clear showing of the construction of the controllably bendable tube section 2.
The controllably bendable tube section 2 shown in FIG. 2 consists of a forward or distal portion 2a and a rearward or proximal portion 2b connected to each other.
The forward portion 2a comprises a plurality of annular segments 6, 7, 9, 11, 13, 15, 16, 17 and 18. The segment 6 is secured to the rearward end of the forward end casing 1 at its forward end and it is provided with a pair of diametrically opposite pivoting portions 6a, 6a at its rearward end which are located in the horizontal diameter at the rearward end. The segment 7 has a pair of diametrically opposite pivoting portions 7a, 7a located in the horizontal diameter at its forward end and a pair of diametrically opposite pivoting portions 7b, 7b located in the vertical diameter at its forward end. The pivoting portions 6a of the segment 6 is pivotally connected to the pivoting portions 7a of the segment 7 by means of pins 8, respectively, so that the segment 6 is swingable in the vertical direction relative to the segment 7. The segment 9 has a pair of diametrically opposite pivoting portions 9a, 9a located in the vertical diameter at its forward end and a pair of diametrically opposite pivoting portions 9b, 9b located in the horizontal diameter at its rearward end. The pivoting portions 7b, 7b of the segment 7 are pivotally connected to the pivoting portions 9a, 9a of the segment 9 by means of pins 10, respectively, so that the segment 7 is swingable in the horizontal direction relative to the segment 9. The segment 11 has a pair of diametrically opposite pivoting portions 11a, 11a located in the horizontal diameter at its forward end while it has a pair of diametrically opposite pivoting portions 11b, 11b located in the horizontal diameter at its rearward end. The pivoting portions 9b, 9b of the segment 9 are pivotally connected to the pivoting portions 11a, 11a by means of pins 14, respectively, so that the segment 9 is swingable in the vertical direction relative to the segment 11. The segments 13, 15 and 16 are similar to the segments 7, 9 and 11, respectively, and they are pivotally connected to the adjacent segments in like manner as described above. The segments 17 and 18 are also similar to the segments 7 and 9, respectively, and they are pivotally connected to the adjacent segments, respectively. Thus, the forward portion 2a can be bent in either of the horizontal and vertical planes passing through the axis of the forward portion 2a.
The number of the segments of the forward portion 2a is not limited to that shown in FIG. 2, but may be varied according to the requirements in design. Further the segments 11, 16 may be omitted under the particular requirements in design.
The rearward portion 2b comprises a plurality of segments 19, 20, 21, 22, 23 which are similar to the segments 11, 16 of the forward portion 2a and a segment 24 having a pair of diametrically opposite pivoting portions located in the horizontal diameter at its forward end. The segments 19, 20 -- 24 are swingably connected to the adjacent segments, respectively, and the rearward end of the segment 24 is secured to the forward end of the flexible tube 3. Thus, the rearward portion 2b is bendable in the vertical plane. The number of the segments in the rearward portion 2b is not limited to that shown in the drawing.
A pair of wires 26a, 26b extend through the controllably bendable tube section 2 and the flexible main tube 3 in the diametrically opposite sides thereof in the vertical plane passing through the axis of the tubes 2 and 3 and the forward ends 26'a, 26'b of the wires 26a, 26b are secured to diametrically opposite portions of the casing 1 while the rearward ends are connected to the first control mechanism represented in FIG. 1 by the knob H 1 so that the wires may be alternately tensioned by the operation of the knob H 1 . Flexible tubes or sheaths 27a, 27b of fixed length, such as closely wound coils, slidably surround the respective wires 26a, 26b and the forward or distal ends 27'a, 27'b of the tubes 27a, 27b are secured to diametrically opposite, distal, terminal portions of the flexible main tube 3 while the rearward ends are secured to stationary portions of the control housing C in a manner indicated in FIG. 1 for sheath 27a only. Thus, the movement of either of the wires 26a, 26b given in the control housing C by the operation of the control mechanism is exactly transmitted to the portion of the wire 26a or 26b at the forward end 27'a or 27'b of the non-contractable flexible tube 27a or 27b, thereby permitting the entire length of the controllably bendable tube 2 to be controllably bent in the vertical plane passing through the axis of the tube 2 by the operation of the knob H 1 regardless of the flexure of the flexible tube 3.
In accordance with the present invention, another pair of wires 24a, 24b extend through the controllably bendable tube 2 section and the flexible main tube 3 at diametrically opposite sides thereof in the horizontal plane passing through the axis of the tubes 2 and 3 and the forward ends 24'a, 24'b of the wires 24a, 24b are secured to diametrically opposite portions of the forward end casing 1 while the rearward ends of the wires 24a, 24b are connected to the second control mechanism represented in FIG. 1 by the knob H 2 so as to be alternately tensioned thereby. A pair of flexible tubes or sheaths 25a, 25b of fixed length slidably surround the respective wires 24a, 24b and the forward ends 25'a, 25'b of the tubes 25a, 25b are secured in diametrically opposite relationship to the inner wall of the segment 19, which is approximately at the longitudinal mid-point of the section 2, while the rearward ends are secured to stationary portions of the control housing C so that the movement given to the wire 24a or 24b in the control housing C by the operation of the knob H 2 is exactly transmitted to the portion of the wire 24a or 24b at the forward end of the tube 25a or 25b. Thus, when the knob H 2 is operated, either of the wire 24a or 24b is tensioned so as to bend the forward portion 2a of the controllably bendable tube 2 in the horizontal plane passing through the axis of the tube 2.
Therefore, the controllably bendable tube 2 can be bent in its entire length by the operation of the knob H 1 while only a limited range, i.e., the forward portion 2a of the tube 2 can be bent by the operation of the knob H 2 , thereby permitting the tube 2 to be bent in various curvatures by selectively operating the knobs H 1 and H 2 . FIG. 3 shows the bent state of the tube 2 when the knob H 1 is actuated while FIG. 4 shows the bent state when the knob H 2 is actuated.
FIG. 5 shows a second embodiment of the present invention. In FIG. 5, a portion of the image transmitting fiber optical system is shown as designated by the reference numeral 106. In this embodiment, the foremost segment 109a and the rearmost segment 109b of the controllably bendable tube section 2' are similar in construction to the segments 6 and 24 shown in FIG. 2, respectively, but all the remaining segments 107 are similar to the segment 11 shown in FIG. 2, and the segments are swingably connected to each other at the mating pivoting portions 107a, 107b by means of pins 108 so that the entire length of the controllably bendable tube section 2' is bent in the plane of FIG. 5. A pair of wires 110a, 110b and a pair of flexible tubes 112a, 112b of fixed length are arranged in like manner as the wires 26a, 26b and tubes 27a, 27b shown in FIG. 2. In the embodiment of FIG. 5, however, a pair of wires 111a, 111b extend in the diametrically opposite sides of the tube 2' closely adjacent to the wires 110a, 110b, respectively, and flexible tubes of fixed length 113a, 113b slidably surround the respective wires 111a, 111b and the forward ends 113'a, 113'b are secured to the inner wall of the segments 107' arranged in about the center of the length of the tube section 2' as shown, while the rearward ends are connected to the second control mechanism represented in FIG. 1 by the knob H 2 instead of the wires 24a, 24b of FIG. 2 so that the wire 111a or 111b is selectively tensioned by the operation of the knob H 2 . The portion of the tube section 2' between the segment 107a and the segment 107' forms the forward portion 2'a.
In operation, when the knob H 1 is operated, the entire length of the tube section 2' is bent in the plane of FIG. 5 while only the forward portion 2'a is bent in the plane of FIG. 5 when the knob H 2 is operated. Thus, the controllably bendable tube section of FIG. 5 is bent in various curvatures by the selective operation of the knobs H 1 and H 2 .
FIG. 6 shows the bent state of the tube section 2' when the knob H 1 is actuated while FIG. 7 shows the bent state when the knob H 2 is actuated.
The embodiments shown in the drawings are front viewing endoscopes. However, the present invention is also applicable to a side viewing endoscope.