U.S. patent number 3,670,721 [Application Number 05/008,776] was granted by the patent office on 1972-06-20 for endoscope.
This patent grant is currently assigned to Olympus Optical Co., Ltd.. Invention is credited to Masaharu Fukami, Toshiyuki Mori.
United States Patent |
3,670,721 |
Fukami , et al. |
June 20, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
ENDOSCOPE
Abstract
Endoscope having a bendable tube connected to a forward end
member adapted to be inserted into a hollow body portion to be
inspected and controlled from a control housing and an elongated
flexible tube connecting the bendable tube and the control housing.
The flexible tube has a thin tubular synthetic resin layer having a
tubular net-like braid of non-metallic fibers embedded therein and
another thin tubular synthetic resin layer having a tubular
net-like braid of metallic fibers embedded therein, the
superimposed resin layers coaxially covering the flexible core of
the flexible tube, and the bendable tube comprises a tubular,
knitted net-like braid of crimped synthetic fibers closely
enveloping a bendable tubular core and a pliable resin tube closely
enveloping the braid, thus providing adequate wall thickness for
the flexible tube and the bendable tube while retaining sufficient
flexibility and twist-resisting property.
Inventors: |
Fukami; Masaharu (Tokyo,
JA), Mori; Toshiyuki (Tokyo, JA) |
Assignee: |
Olympus Optical Co., Ltd.
(Tokyo, JA)
|
Family
ID: |
21733602 |
Appl.
No.: |
05/008,776 |
Filed: |
February 5, 1970 |
Current U.S.
Class: |
600/140;
273/DIG.5 |
Current CPC
Class: |
A61B
1/0055 (20130101); Y10S 273/05 (20130101) |
Current International
Class: |
A61B
1/005 (20060101); A61b 001/06 () |
Field of
Search: |
;128/4,5,6,7,8,9 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Laudenslager; Lucie H.
Claims
We claim:
1. In an endoscope including a control housing and an elongated
tubular element having one longitudinally terminal portion secured
to said housing, another longitudinally terminal portion remote
from said housing and formed with a viewing window, and a
longitudinal, flexible portion intermediate said terminal portions,
said intermediate portion having a tubular, flexible, metallic
core, the improvement of said intermediate portion which
comprises:
a. a first, tubular, synthetic resin layer substantially coaxially
engagingly superimposed on said core;
b. a second, tubular, synthetic resin layer substantially coaxially
superimposed on said first layer;
c. a first tubular, net-like braid of non-metallic fibers embedded
in one of said resin layers; and
d. a second tubular, net-like braid of metal fibers embedded in the
other resin layer.
2. In an endoscope as set forth in claim 1, wherein the tubular
element has a bendable portion longitudinally intermediate said
other longitudinally terminal portion and said flexible portion
thereof, the endoscope including operating means on said housing
for bending said bendable portion, the bendable portion having a
tubular core adapted to be bent by said operating means and an
outer shell of elastomeric material, the improvement in said
bendable portion which comprises a tubular, net-like braid of
crimped synthetic fibers closely enveloping said core and being
closely enveloped by said shell.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope, and more
particularly to the novel and useful construction of the elongated
flexible tube and the controllably bendable tube connecting the
control housing of the endoscope to the forward end member thereof
to be inserted into a hollow portion of a living body to be
inspected by the endoscope.
An endoscope comprises in general a forward end member connected to
a control housing through a controllably bendable tube and an
elongated flexible tube. The controllably bendable tube is located
adjacent to the forward end member and must have sufficient
bendability and also sufficient strength against collapsing so that
it can be bent in the desired direction and by the desired angle
thereby permitting the forward end member to be easily inserted
through a passage having complicated curvatures into a hollow
portion to be inspected and directed to an object for the proper
inspection thereof, while the elongated flexible tube is made
yieldable to follow the curvature of the passage but resists
twisting.
Optical systems are provided in the forward end member for
illuminating the object to an eyepiece in the control housing or
photographed by a camera provided in the control housing.
Since the passage through which the forward end member is inserted
is relatively thin, the diameter of the forward end member as well
as the bendable tube and the flexible tube must be made as small as
possible while the inner diameter of the bendable tube and the
flexible tube must be as large as possible in order to accomodate
the light and the image transmitting optical systems and other
elements.
The present invention aims at providing improved flexible and
bendable tubes for an endoscope.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an endoscope with
an elongated flexible tube which is sufficiently flexible but
resists twisting while the wall thickness thereof is reduced to a
minimum.
Another object of the present invention is to provide an endoscope
with a bendable tube of sufficient bendability while the wall
thickness thereof is at a minimum.
The above objects are achieved in accordance with the present
invention by an elongated flexible tube characterized by a thin
tubular synthetic resin layer having a tubular net-like braid made
of non-metallic fibers embedded therein and a thin tubular
synthetic resin layer having a tubular net-like braid made of
metallic fibers embedded therein, the two layers being superimposed
and closely enveloping a flexible tubular metallic core member
thereby affording sufficient flexibility and twist-resisting
property to the elongated flexible tube at minimum wall thickness
so that sufficient space is provided in the interior of the
elongated flexible tube. The bendable tube has a tubular net-like
braid knitted of crimped synthetic fibers and closely enveloping a
bendable tubular core, a pliable resin tube being laid closely
around the braid to provide sufficient bendability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general side view of a conventional endoscope;
FIG. 2 is a fragmentary longitudinal sectional view of the
elongated flexible tube of the endoscope of FIG. 1;
FIG. 3 is a fragmentary longitudinal sectional view of another
known flexible tube of an endoscope;
FIG. 4 is a fragmentary longitudinal sectional view of an elongated
flexible tube constructed in accordance with the present
invention;
FIG. 5 is a fragmentary plan view of the braid used in the tube
shown in FIG. 4;
FIG. 6 is a fragmentary side view partly in section showing the
construction of the bendable tube of a known endoscope;
FIG. 7 is a fragmentary side view of a bendable tube constructed in
accordance with the present invention; and
FIG. 8 is a fragmentary side view shown the procedure of producing
the braid used in the bendable tube of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 showing a conventional endoscope, the elongated
tubular endoscope element has a forward end member 1 connected to
control housing 2 through an elongated yieldably flexible tube
portion 3 and a controllably bendable tube portion 4. The
controllably bendable tube 4 is located adjacent to the forward end
member 1 and controlled by an operating handle 5 through connecting
means such as strings (not shown) so that the forward end member 1
is directed to the desired direction with respect to an object for
the proper inspection thereof.
A viewing window 6 and an illuminating window 7 are provided in the
wall of the forward end member 1. An elongated light conducting
optical system (not shown) extends through the tube 4 and the tube
3 from the illuminating window while the rearward end 8 thereof
extends beyond the control housing 2 so as to be connected to an
external light source (not shown).
An objective lens and a reflecting prism (not shown) in the forward
end member 1 at the viewing window 6 and an image transmitting
optical system (not shown) permits an image to be viewed through an
eyepiece 9 provided in the control housing 2.
In the prior art construction of the elongated flexible tube 3
shown in FIG. 2, a helically wound thin strip of metal 10 is laid
closely around an oppositely helically wound thin strip of metal 11
so as to form the core of the elongated flexible tube 3. A pliable
tube 12 made of a material such as polyvinyl chloride resin is laid
closely around the helically wound thin strip 10.
FIG. 3 shows another example of a known flexible tube 3' which
comprises a helically wound thin strip of metal 11 forming the core
of the elongated flexible tube 3', a tubular net-like metallic
braid 13 closely laid around the strip 11 and a pliable tube 12
laid closely around the braid 13.
The elongated flexible tube 3 of FIG. 2 has a relatively great wall
thickness and poor yieldability. The tube 3' of FIG. 3 has also a
relatively great wall thickness although the yieldability is
slightly improved in comparison with that of the tube 3.
In accordance with the present invention, an elongated flexible
tube 3" shown in FIG. 4 comprises a helically wound thin strip of
metal 11 similar to that shown in FIG. 2. A tubular net-like braid
14 made of non-metallic fibers such as cotton, silk or plastic is
laid coaxially around the strip 11, and soft synthetic resin
compound is applied to the braid 14 by coating with or dipping in
the molten resin compound so as to form a thin resin layer 15 in
which the braid 14 is embedded and which engages the strip 11.
In the like manner, a tubular metallic braid 16 of piano wires or
stainless steel wires is laid closely around the layer 15, and soft
synthetic resin compound is applied to the braid 16 by coating or
dipping so as to form a thin resin layer 17 in which the braid 16
is embedded.
In a similar manner, a thin resin layer 18 with a braid 19 of
non-metallic fibers embedded therein is provided around the resin
layer 17.
The number of layers may be increased so as to form the desired
thickness of the wall in which resin layers having embedded braids
of non-metallic fibers and the resin layers having the braid of
metallic fibers alternate.
FIG. 5 shows an example of the braid used in the present
invention.
As to the resin compound, any resin compounds can be used insofar
as they have sufficient pliability and are harmless to the living
body.
The elongated flexible tube 3" has appropriate flexibility and
resiliency as well as sufficient yieldability and twist resistance
while its wall thickness is held to a minimum. The longitudinal end
of the tube 3" remote from the bendable tube constitutes a terminal
portion of the tubular endoscope element which is secured to the
control housing 2.
FIG. 6 shows a known bendable tube 4 of an endoscope connected to
the forward end member 1. It comprises a tubular core consisting of
short tubular segments 20 connected by pivot pins 20a, a pliable
tube 21 made of polyvinyl chloride or Neoprene laid closely around
the core, a metallic braid 22 of stainless steel or piano wires
closely laid around the pliable tube 21 and a pliable outer shell
23 made of an elastomeric material such as polyvinyl chloride or
rubber. Therefore, the wall thickness of the tube 4 is relatively
great thereby reducing the space utilizable to locate the various
elements therein.
In accordance with the present invention, the bendable tube 4'
shown in FIG. 7 is provided with a thin wall which affords
sufficient bendability and resistance against collapsing and
twisting.
The core of the tube 4' consists of a tubular segments 20 joined by
pivot pins 20a as in FIG. 6. A tubular braid 24 of knitted crimped
synthetic fibers such as nylon fibers is laid closely around the
core, and a pliable tube or outer shell 25 made of soft synthetic
resin compound closely envelopes the braid 24.
The tube 4' has a relatively small wall thickness while it has
sufficient bendability and resistance against collapsing and
twisting.
The pliable tube 25 may be formed by dipping the braid 24 in the
molten synthetic resin compound or by coating the braid 24 so that
the synthetic resin compound is impregnated into the braid 24.
FIG. 8 shows an example of the process for forming the braid 24. A
cylindrical form 26 having an inner diameter greater than the outer
diameter of the core in the tube 4' is placed around the core, and
the crimped fibers 24a are wound around the form 26 so as to form a
net-like structure. Thereafter, the form 26 is withdrawn, thereby
permitting the net-like structure of fibers 24a to contract into
engagement with the core by the crimping effect or by appropriate
heat treatment.
* * * * *