Surgery – Endoscope – Having flexible tube structure
Reexamination Certificate
2001-04-18
2004-01-06
Campbell, Thor (Department: 3742)
Surgery
Endoscope
Having flexible tube structure
C600S139000, C600S101000
Reexamination Certificate
active
06673012
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a control device having a rotary steering device. The present invention also relates to a control device of an endoscope which has a rotary steering device for steering the distal end of an endoscope, and a locking device for locking the rotary steering device to lock the distal end of the endoscope.
2. Description of the Related Art
A typical endoscope is generally provided with an insertion portion which is inserted into a hollow organ or part such as an body cavity or an inner part of a jet engine, and a rotary steering device for steering the distal end of the endoscope to adjust the distal end to a desired curved shape, i.e., to adjust the orientation of the tip of the distal end. Manually turning an angle knob (a control knob) provided on the control body of the endoscope about a stationary rotational shaft causes the distal end of the insertion portion of the endoscope to bend in right and left or upward and downward via a control wire having a distal portion anchored to the distal end of the insertion portion of the endoscope. In general, the endoscope is provided with a locking device for locking the angle knob to lock the distal end of the endoscope to maintain the desired curved shape thereof. This locking device is operated by manually operating a lock knob which is rotatably provided about the aforementioned rotational shaft. Such a locking device is known in the art in the form of a friction locking device which includes a friction pad provided on the lock knob side and another friction pad provided on the angle knob side, wherein the friction pad provided on the lock knob side moves toward and away from the friction pad provided on the angle knob side, in a direction of the axis of the aforementioned rotational shaft, by rotation of the lock knob, and wherein the friction pad provided on the angle knob side rotates together with the angle knob by rotation of the angle knob. In this locking device, if the lock knob is turned in a predetermined rotational direction, the friction pad provided on the lock knob side moves toward the friction pad provided on the angle knob side while rotating about the rotational shaft together with the lock knob via a screw mechanism and eventually comes into contact with the friction pad provided on the angle knob side. Further rotational movement of the lock knob in the same rotational direction causes the friction pad provided on the lock knob side to come into pressing contact firmly with the friction pad provided on the angle knob side to thereby lock the angle knob by friction resistance generated between the friction pad provided on the lock knob side and the friction pad provided on the angle knob side. With the frictional locking device having such structure, the angle knob is prevented from rotating unintentionally, which prevents the distal end of the endoscope from moving unintentionally.
One problem which resides in the endoscope having such a frictional locking device, is that the rotation of the friction provided on the lock knob side pad may be transmitted slightly to the angle knob via the friction pad provided on the angle knob side, causing the shape of the distal end of the endoscope to change slightly since the friction pad provided on the lock knob side comes into pressing contact with the friction pad provided on the angle knob side while rotating about the aforementioned rotational shaft when the lock knob is turned to lock the angle knob. As a result, the distal end of the endoscope may be locked to an undesired curved shape with the frictional locking device.
Endoscopes provided with a plurality of angle knobs for steering the distal end of the endoscope are known in the art. For instance, an endoscope having two angle knobs is known. In this endoscope, the distal end of the endoscope swings in two directions perpendicular to each other by operating the two angle knobs, respectively, via a pair of control wires having respective distal portions anchored to the distal end of the endoscope. Therefore, the distal end of the endoscope can be freely deflected right, left, upward and downward by operating the two angle knobs.
However, in such a conventional type of endoscope, in the case where the above described frictional locking device is provided for each of the two angle knobs, there is a possibility that the operational force of the frictional locking device given to one of the two angle knobs exerts an adverse effect on the operability of the other angle knob. For instance, in the case where the two angle knobs are coaxially arranged adjacent to each other and where the frictional locking device is structured so that one of the two angle knobs is locked by a pressing force toward the other angle knob, this pressing force may have an adverse effect on the other angle knob that does not have to be locked to thereby deteriorate the operability of the other angle knob that needs to be manually rotatable freely and smoothly.
A rotary control member such as a knob or a lever is widely used as a control member for adjusting or locking the distal end of an endoscope, i.e., as an element of the aforementioned steering device or the aforementioned locking device. Generally, such a rotary control member is held rotatably via a retaining mechanism for preventing the rotary control member from coming off a control center shaft (a rotational shaft) in an axial direction thereof. Further, such a rotary control member used for locking the distal end of an endoscope is often provided with a rotational-position control mechanism for making the rotary control member stop with a click at each of the lock and unlock positions thereof. Providing the endoscope with such a rotational-position control mechanism together with the aforementioned retaining mechanism tends to complicate the mechanical structure of the endoscope around the rotary control member thereof.
The aforementioned retaining mechanism is known in the art in the form of a mechanism having a retaining ring which is fitted in an annular groove formed around one end of the control center shaft. In this retaining mechanism, although there is play between the retaining ring and the control center shaft in radial directions perpendicular to the axial direction of the control center shaft, the control center shaft preferably does not rattle due to the play with the retaining ring being engaged with the control center shaft in place. This is true not only for the steering device for steering the distal end of an endoscope but also for any other similar steering devices having a rotary control member corresponding to the aforementioned rotary control member in mechanical apparatuses other than endoscopic apparatuses.
The aforementioned friction pad provided on the lock knob of the locking device is known in the art in the form of a doughnut-shaped disk pad
114
′ made of cork or rubber such as shown in FIG.
33
. The disk pad
114
′ having such a doughnut shape is not easily deformed by external forces applied thereto. Namely, the doughnut shape resists crushing and thus provides stability to the shape of the disk pad
114
′. Due to such characteristics of the disk pad
114
′, in the locking device using the disk pad
114
′, the amount of movement of the disk pad
114
′ is generally small in the axial direction of the aforementioned rotational shaft between a point at which the disk pad
114
′ is barely in contact with the aforementioned friction pad provided on the angle knob side and another point at which the disk pad
114
′ comes in pressing contact firmly with the friction pad to generate a sufficient friction resistance between the disk pad and the friction pad to lock the associated angle knob. Furthermore, this locking operation using the lock knob tends to require great force for turning the lock knob manually.
Therefore, when the lock knob is turned manually, the locking force varies significantly even if the amount of rotation o
Fujii Yoshinori
Sugiyama Akira
Campbell Thor
Greenblum & Bernstein P.L.C.
Pentax Corporation
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