JPS6160690B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope with an improved operating mechanism for a bending section.

Generally, an endoscope has a curved section on the distal end of the insertion section.
An operating section is provided on the rear end side, and the bending section can be remotely operated using this operating section.

As a means for remotely operating the bending section, there is a method in which a pulley is provided in the operating section and the pulley pushes and pulls a wire to bend the bending section. However, with such means, the wire must be fixed to the pulley by brazing or the like to prevent the wire from slipping against the pulley. Therefore, not only was the brazing work time-consuming, but there was also the risk that the wire would come off at the brazed portion if a large force was applied to the wire.

Also, if the wire is driven by a pulley,
An absorption mechanism is required to absorb this slack in the wire. In other words, when the pulley is rotated, the wire has a tension side and a slack side, so if the slack on the slack side is not absorbed, the wire will meander repeatedly, causing early fatigue. It will cause it to break. However, providing the above-mentioned slack absorption mechanism not only complicates the structure but also increases the size of the operating section.

In order to eliminate the drawbacks of the bending operation mechanism using wires and pulleys, a bending mechanism using sprockets and roller chains has been adopted. This bending operation mechanism is as follows. That is, the operating portion is provided with a sprocket that interlocks with the operating knob, and a roller chain is engaged with the sprocket over approximately half its circumference. A pair of operating wires is connected at one end to each end of the roller chain, and the other end is connected to the tip of the curved portion. Therefore, when the sprocket is rotated via the operating knob, one operating wire is pulled through the roller chain and the other operating wire is loosened, so that the bending portion can be operated to bend.

By the way, according to such a configuration, when the sprocket is rotated as described above in order to curve the bending portion, the other operating wire is loosened, and the one end side of the roller chain to which this operating wire is connected also undergoes the above-mentioned operation. It will come loose with the wire. If the sprocket is further rotated in this state, the loosened roller chain may get caught in the part of the sprocket where the roller chain is not engaged, causing the sprocket to stop rotating. If such a situation occurs while the insertion tube is being inserted into a body cavity, the curved portion cannot be returned to its original shape, resulting in a serious accident in which the insertion tube cannot be removed from the body cavity. There is a risk of causing

This invention was made based on the above-mentioned circumstances, and its purpose is to prevent the roller chain from becoming entangled in the sprocket even if one end of the roller chain meshed over approximately half the circumference of the sprocket becomes slack. In this way, it is an object of the present invention to provide an endoscope whose curved portion can be operated reliably.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. 1 in FIG. 1 is an endoscope. This endoscope 1 has an operation section 3 on the rear end side of the insertion section 2.
A curved portion 4 and a tip forming portion 5 are provided at the tip.
are provided in sequence. The operation section 3 is provided with an operation knob 7 for operating a bending operation device 6 to be described later, and by rotating the operation knob 7, the bending section 4 can be bent. Further, a light guide cable 8 is led out from the operating section 3, and a connector 9 is provided at the end thereof to be connected to a light source device (not shown).

On the other hand, the bending operation device 6 is constructed as shown in FIGS. 2 and 3. That is, a base plate 10 is provided within the operating section 3, and a support shaft 11 having a screw 11a formed at its upper end is protruded from the upper surface of one end side of the base plate 10. The operation knob 7 having a boss portion 12 is rotatably provided on the support shaft 11 through an insertion hole 13 bored along its axial direction, and is screwed into the screw 11a of the support shaft 11. It is held by a nut 14 so as not to be pulled out.

Further, a sprocket 15 is fitted onto the boss portion 12 of the operation knob 7, and a roller chain 16 is provided on the sprocket 15 so as to mesh over approximately half the circumference thereof. Both ends of this roller chain 16 extend in the longitudinal direction of the substrate 10, that is, from the operating section 3 toward the insertion section 2, and a pair of link plates 17, 17 at both ends have coupling members 18, 18, respectively, which are rotatable. freely connected.
A first operating wire 19 and a second operating wire 20 are fixed at one end to these coupling members 18, 18. The other ends of the first operating wire 19 and the second operating wire 20 are guided to the bending section 4, where they are connected to a plurality of rotatably connected node rings (not shown) that constitute the bending section 4. ) is connected to the most advanced node ring.

Further, the substrate 10 has an arcuate side surface 21a near a portion of the sprocket 15 in which the roller chain 16 is not engaged, or in the gap between the upper surface of the substrate 10 and the lower surface of the sprocket 15 in this embodiment. A plate-shaped entanglement prevention member 21 is fixed substantially flush with the outer peripheral surface of the sprocket 15.

Next, the operation of the above configuration will be explained. First, when the operation knob 7 is rotated in the direction shown by the arrow in FIGS. 1 and 2, the sprocket 15 provided integrally with the operation knob 7 rotates in the same direction. The roller chain 16 meshed over approximately half the circumference is driven in the direction shown by the arrow in FIG. When this roller chain 16 is driven, the first wire 19 connected to one end thereof is pushed in, and the second operating wire 20 connected to the other end thereof is pulled, so that the curved portion 4 As shown by the chain line in FIG. 1, it curves in the direction pulled by the second operating wire 20.

During such a bending operation, the roller chain 1
The first operating wire 19 on the side pushed in by 6
It is clear that slack will occur in the roller chain 16 along with this first operating wire 19.
One end of the will loosen inward. Therefore, there is a risk that the slack portion of the roller chain 16 may be caught in the portion of the sprocket 15 with which the roller chain 16 is not engaged.

However, in the vicinity of the part of the sprocket 15 where the roller chain 16 is not engaged, an entrainment prevention member 21 is provided with one side 21a substantially flush with the outer peripheral surface of the sprocket 15, so the roller chain 16 can prevent this entrainment. When the member 21 hits one side 21a, it is prevented from being caught in the sprocket 15. Therefore, the bending operation of the bending portion 4 can be performed reliably.

Note that this invention is not limited to the above embodiment,
For example, the entanglement prevention member 21 may have a U-shaped cross section as shown in FIG. 5, and the part of the sprocket 15 that is not engaged with the roller chain 16 may be housed inside this U-shape. In short, any material that can prevent the slack roller chain 16 from being caught in the part of the sprocket 15 that does not mesh with the roller chain 16 is sufficient.

As described above, the present invention provides an entanglement preventing member that is located near a portion of a sprocket in which a roller chain is engaged over approximately half the circumference and in which the roller chain is not engaged, and that prevents the roller chain from being entangled in this portion. has been established. Therefore, when bending the bending section, it is possible to eliminate the risk that the loosened roller chain will get caught up in the sprocket, making it impossible to operate the bending section. Further, unlike the conventional bending operation mechanism in which the wire is driven by a pulley, there is no need to braze the wire to the pulley, and there is no risk of the brazed portion coming off the pulley. Furthermore, since there is no need for an absorption mechanism for absorbing the slack of the wire, there is no need for a complicated structure or an increase in the size of the operating section.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the present invention, FIG. 1 is a perspective view of an endoscope, FIG. 2 is a perspective view showing a schematic configuration of a bending operation device, and FIG. 3 is a main part. 4 is a perspective view of the entrainment prevention member, and FIG. 5 is a sectional view showing an entrainment prevention member according to another embodiment of the present invention. 2... Insertion section, 3... Operation section, 4... Curved section,
7...Operation knob, 15...Sprocket, 16...
...roller chain, 19,20...operation wire,
21... Entanglement prevention member.

Claims (1)

[Claims] 1. A bending section provided at the distal end of the insertion section is operated by an operating section provided at the rear end of the insertion section via an operating wire, wherein the operating section is connected to operating wires at both ends. A roller chain is provided that meshes with the sprocket over approximately half the circumference thereof, and an entanglement prevention member is provided near the portion of the sprocket where the roller chain is not meshed to prevent the roller chain from being caught in this portion. An endoscope equipped with