Endoscope device

In this invention, an attachment for changing a view angle and visual field direction or protecting a tip portion and others is removably fitted to a tip portion of an endoscope inserting portion. A connecting member pulling in and fixing this attachment is rotatably and nonremovably fitted on the outer periphery of the tip portion of the endoscope inserting portion. In order that this connecting member may not be pulled out of the tip portion of the endoscope inserting portion, a groove is peripherally formed on the outer periphery of the tip portion and engaging members engaging in this groove and having an elastic deformability are provided on the connecting member.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to endoscope devices and more particularly to an 
endoscope device removably fitted in a tip portion of an endoscope 
inserting portion with an attachment for changing a view angle and visual 
field direction or protecting the tip portion and others. 
2. Related Art Statement 
There is recently extensively used a (medical) endoscope whereby an 
elongated inserting portion can be inserted into a body cavity to observe 
the interior of the body cavity or any treating tool can be used for such 
treatment as therapy. Among such endoscopes, there is also an industrial 
endoscope which can be inserted into an instrument or piping to inspect or 
treat its interior. Among such endoscopes, there are a flexible endoscope 
wherein the inserting portion is flexible and a rigid endoscope wherein 
the inserting portion is rigid. 
Now, an endoscope is inserted, for example, into a body cavity, an 
illuminating light is radiated toward an object position within the body 
cavity, a reflected light from the object forms an image with an objective 
lens and the image is transmitted to an eyepiece through image guide 
fibers or the like so that the object can be sighted and observed. 
Therefore, depending on the object to be observed, it may be necessary to 
change a view angle or visual field direction and to protect the tip 
portion of the inserting portion or the object. 
Therefore, there is already known a device which can be removably fitted in 
a tip portion of an endoscope inserting portion with an attachment for 
changing a view angle and visual field direction or protecting the tip 
portion. An example of it is shown in FIG. 1. 
In FIG. 1, the reference numeral 1 represents an inserting portion of an 
endoscope and 2 represents a tip portion of the endoscope inserting 
portion. An attachment 3 for changing a view angle and visual field 
direction or protecting the tip portion 2 can be removably fitted to this 
tip portion 2. This attachment 3 has a recess 4 in which the endoscope tip 
portion 2 is to be engaged in the rear part, that is, on the endoscope 
connecting side and has a female screw 5 provided on the inner peripheral 
wall of the recess 4. On the other hand, a tubular connecting member 7 
having a male screw 6 provided to be screwed with the above mentioned 
female screw 5 is rotatably fitted on the outer periphery of the endoscope 
tip portion. The male screw 6 of the connecting member 7 and the female 
screw 5 of the attachment 3 are screwed with each other and the connecting 
member 7 is rotated to pull in and fix the attachment 3 with the screws. 
Now, in this formation, as a means whereby the tubular connecting member 7 
removably fitted to the above mentioned endoscope tip portion 2 to fix the 
attachmnet 3 is held by the tip portion 2 so as not to be pulled off and 
dropped, conventionally a groove 8 in the peripheral direction has been 
peripherally formed in the tip portion of the connecting member 7 to be 
fitted on the outer periphery of the tip portion 2 and a C-ring 9 has been 
fitted in this groove 8. 
However, in the connecting member holding means using the above mentioned 
conventional C-ring, in order that the C-ring may not be removed by an 
external force when the attachment is not fitted, it is necessary to 
elevate the dimensional precision of the C-ring. That is to say, the 
C-ring is in a form so plastically deformable that, when it is deformed, a 
space catching on the groove will be reduced and the C-ring will be likely 
to be removed. Therefore, it is necessary to take special care in working 
and storing the parts of the C-rings and assembling the products. 
Such endoscope devices of this kind are seen to be suggested in the 
gazettes of Japanese utility model publications Nos. 31210/1984 and 
87704/1982. In the prior art examples, a connecting member is rotatably 
and nonremovably fitted to the tip portion of an endoscope and a screw 
provided on the connecting member and a screw of the attachment are 
screwed with each other to screw and fix this attachment into the end 
portion of the endoscope. In these prior art examples, as a means whereby 
the connecting means for fixing the attachment to the endoscope tip 
portion is held in the endoscope tip portion so as not to be removable, 
the outer peripheral diameter of the endoscope tip portion in front of 
this connecting member is made larger or a flange is formed. 
OBJECTS AND SUMMARY OF THE INVENTION 
An object of this invention is to provide an endoscope device wherein a 
tubular member for removably fixing an attachment to a tip portion of an 
endoscope can be positively and rotatably locked in the endoscope tip 
portion and the parts can be easily made, stored, assembled and reduced. 
Another object of this invention is to provide an endoscope device wherein 
the above mentioned connecting member can be easily fitted to the 
endoscope tip portion from the tip side and therefore the connecting 
member can be easily fitted. 
Briefly, the endoscope device according to the present invention comprises 
an attachment having in the rear part a recess in which an inserting 
portion of an endoscope is engaged, having a female screw provided on the 
inner peripheral wall of the recess and removably connected and fixed to 
the tip portion, a connecting member rotatably fitted on the outer 
periphery of the tip portion of the inserting portion of the endoscope, 
having a male screw screwed with the female screw of the above mentioned 
attachment on the outer periphery on the tip side and pulling in and 
fixing the attachment, a groove formed peripherally on the outer periphery 
of the tip portion of the endoscope inserting portion in the tip side 
position of the connecting member and an engaging member extended to the 
tip portion of the connecting member and having an elastic deformability 
so as to be engaged with the above mentioned groove of the endoscope tip 
portion. 
This and other objects and advantages of the present invention will become 
further apparent from the following detailed explanation.

BEST MODE FOR CARRYING OUT THE INVENTION 
In FIGS. 2 and 3, the reference numeral 11 represents an inserting portion 
of an endoscope and 12 represents its tip portion. An attachment 13 for 
changing a view angle and visual field direction or protecting an 
objective lens and object so as not to be hurt can be removably connected 
and fixed to this tip portion 12. This attachment 13 has a recess 14 in 
which an endoscope tip forming portion 29 is to be engaged in the rear 
part, this is, on the endoscope connecting side and has a female screw 15 
provided on the inner peripheral wall of the recess 14. On the other hand, 
a tubular connecting member 17 having a male screw 16 to be screwed with 
the female screw 15 of the above mentioned attachment 13 provided on the 
tip side is rotatably fitted on the outer periphery of the endoscope tip 
forming portion 29. Also, a groove 18 is peripherally formed on the outer 
periphery of the endoscope tip forming portion 29 in the tip portion 
position of this fitted connecting member 17. 
The above mentioned connecting member 17 has an engaging member 19 having a 
projecting portion 19a projecting in the inside diameter direction so as 
to be engaged with the groove 18 in the position of the groove 18 when 
fitted to the tip portion, that is, to the endoscope and has a plurality 
of slits 20 formed thin in the axial direction so as to give the engaging 
member 19 an elastic deformability returning in a diameter contracting 
direction. The rear part side of this connecting member 17 is an operating 
portion 21 having knurls. 
By the way, in the drawing, the reference numeral 22 represents image 
guiding fibers, 23 represents an objective lens, 24 represents a cover 
glass, 25 represents light guiding fibers, 26 represents a cover glass, 27 
represents an objective system of the attachment and 28 represents an 
illuminating system. 
In such formation, in assembling, when the tubular connecting member 17 is 
fitted to the endoscope tip forming portion 29 from the tip side and the 
engaging member 19 of the connecting member 17 passes over the edge part 
of the groove 18, it will be elastically deformed in a diameter expanding 
direction but, on the other hand, when the engaging member 19 passes over 
the edge part of the groove 18 and comes to the groove 18, the engaging 
member 19 will return to the original diameter and will be engaged with 
the groove 18 and the connecting member 17 will be able to be rotatably 
and positively locked in the endoscope tip forming portion 29. Therefore, 
once the above mentioned connecting member 17 is fitted to the endoscope 
tip forming portion 29, even if an ordinarily expected external force is 
applied, the tip side having the engaging member 19 will be very unlikely 
to be expanded and, even if one side of the tip side divided by the slits 
20 is expanded, unless the remaining tip side is simultaneously expanded, 
the engaging member 19 will not be disengaged with the groove 18. Also, 
this connecting member is more rigid in the structure than the C-ring and 
requires no working dimensional precision and the stock of the parts is 
easy to control. Further, in assembling, if the connecting member 17 is 
only pushed onto the outer periphery of the endoscope tip forming portion, 
the connecting member 17 will be assembled and therefore will be high in 
the workability. 
By the way, in this invention, the groove 18 formed peripherally on the 
outer periphery of the tip forming portion 29 may be formed by providing a 
peripheral projection or being cut to be of a small diameter without 
providing a projection. 
In this invention, it is apparent that working modes different in a wide 
range can be formed on the basis of this invention without departing from 
the spirit and scope of the invention. This invention is not restricted by 
any specific embodiment except being limited by the appended claims.