U.S. patent application number 09/775629 was filed with the patent office on 2001-10-04 for miniature rope.
This patent application is currently assigned to ASAHI KOGAKU KOGYO KABUSHIKI KAISHA. Invention is credited to Ouchi, Teruo.
Application Number | 20010025475 09/775629 |
Document ID | / |
Family ID | 18557509 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010025475 |
Kind Code |
A1 |
Ouchi, Teruo |
October 4, 2001 |
Miniature rope
Abstract
A miniature rope formed of metal includes: a core wire; and a
plurality of surrounding wires wound around the core wire so as to
form a stranded wire as a whole, wherein the core wire is formed of
a material whose characteristics differ from those of the
surrounding wires. Specifically, the core wire may be a tungsten
wire, a superelastic alloy wire, or a nickel-titanium alloy wire,
while the surrounding wires may be stainless steel wires.
Inventors: |
Ouchi, Teruo; (Saitama,
JP) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1941 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Assignee: |
ASAHI KOGAKU KOGYO KABUSHIKI
KAISHA
Tokyo
JP
|
Family ID: |
18557509 |
Appl. No.: |
09/775629 |
Filed: |
February 5, 2001 |
Current U.S.
Class: |
57/224 |
Current CPC
Class: |
D07B 1/0693 20130101;
A61B 1/0052 20130101 |
Class at
Publication: |
57/224 |
International
Class: |
D02G 003/36; D02G
003/08; D02G 003/06; D02G 003/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2000 |
JP |
P2000-032959 |
Claims
What is claimed is:
1. A miniature rope formed of metal comprising: a core wire; and a
plurality of surrounding wires wound around said core wire so as to
form a stranded wire as a whole, wherein said core wire is formed
of a material whose characteristics differ from those of said
surrounding wires.
2. The miniature rope according to claim 1, wherein said core wire
has characteristics which excel in the tensile strength and the
difficulty of formation of a kink as compared with said surrounding
wires, and said surrounding wires has a characteristic excelling in
wear resistance as compared with said core wire.
3. The miniature rope according to claim 1, wherein said
surrounding wires are stainless steel wires.
4. The miniature rope according to claim 1, wherein said core wire
is a tungsten wire.
5. The miniature rope according to claim 1, wherein said core wire
is a superelastic alloy wire.
6. The miniature rope according to claim 1, wherein said core wire
is a nickel-titanium alloy wire.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a miniature rope for use as
an operating wire for an endoscope, and more particularly to a
metallic miniature rope which is formed as a stranded wire as a
whole by spirally winding aplurality of surrounding wires around a
core wire.
[0002] As a miniature rope for use in an endoscope, a miniature
rope of a so-called 1.times.7 construction in which six surrounding
wires are spirally wound around a core wire is widely used. In
addition, miniature ropes of a 1.times.19 construction, 1.times.37
construction, and the like are also used. Stainless steel wires are
generally used as the core wire and the surrounding wires.
[0003] In some applications, however, there are cases where it is
compelled to use a miniature rope having a high tensile strength
without enlarging the outside diameter, or use a miniature rope in
which a kink is difficult to occur.
[0004] Accordingly, if the miniature rope is formed of tungsten
wires having characteristics that the tensile strength is strong
and a kink is difficult to occur, it is possible to obtain a
miniature rope having excellent characteristics which cannot be
obtained by stainless steel wires.
[0005] However, since the tungsten wires are low in wear
resistance, if they are rubbed against a hard object, the tungsten
wires have the drawback of being cut off easily, so that it is
impractical to fabricate a miniature rope using tungsten wires.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an object of the invention to provide a
miniature rope which exhibits excellent characteristics that cannot
be obtained by a miniature rope of the conventional construction
and which is capable of being put to practical use.
[0007] In the present invention, a core wire is formed of a
material whose characteristics differ from those of surrounding
wires. This makes it possible to provide a miniature rope which
exhibits excellent characteristics that cannot be obtained by a
miniature rope of the conventional construction and which is
capable of being put to practical use.
[0008] In particular, if the core wire has characteristics which
excel in the tensile strength and the difficulty of formation of a
kink as compared with the surrounding wires, and the surrounding
wires has a characteristic excelling in wear resistance as compared
with the core wire, it is possible to obtain excellent durability
in a case where the miniature rope is used as a wire for an
endoscope.
[0009] A miniature rope of a preferred embodiment of the present
invention is formed of metal and includes: a core wire; and a
plurality of surrounding wires spirally wound around the core wire
so as to form a stranded wire as a whole, wherein the core wire is
formed of a material whose characteristics differ from those of the
surrounding wires.
[0010] In the above arrangement, if the core wire has
characteristics which excel in the tensile strength and the
difficulty of formation of a kink as compared with the surrounding
wires, and the surrounding wires has a characteristic excelling in
wear resistance as compared with the core wire, it is possible to
obtain a miniature rope exhibiting excellent durability.
[0011] It should be noted that the surrounding wires may be
stainless steel wires, and the core wire may be a tungsten wire, a
superelastic alloy wire, or a nickel-titanium alloy wire.
[0012] The present disclosure relates to the subject matter
contained in Japanese patent application No. 2000-32959 (filed on
Feb. 10, 2000), which is expressly incorporated herein by reference
in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a cross-sectional view of a miniature rope in
accordance with an embodiment of the invention, and is taken along
line I-I in a direction perpendicular to its axis in FIG. 2,;
[0014] FIG. 2 is a side elevational view of the miniature rope in
accordance with the embodiment of the invention;
[0015] FIG. 3 is a side elevational view of an endoscope in which
the miniature rope of the invention is used; and
[0016] FIG. 4 is a plan view, partly in section, of a distal end
portion of a snare for an endoscope in which the miniature rope of
the invention is used.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Referring to the accompanying drawings, a description will
be given of an embodiment of the invention.
[0018] FIG. 2 is side elevational view of a miniature rope 10 in
accordance with the embodiment of the invention, and FIG. 1 shows a
section taken along line I-I perpendicular to an axis thereof.
[0019] The miniature rope 10 is a slender metallic rope whose
outside diameter is 1 mm or less or several millimeters or less.
The miniature rope 10 in this embodiment is formed as a stranded
wire as a whole by spirally winding six surrounding wires 12 around
a core wire 11. As the direction of spirally winding the
surrounding wires 12 with respect to the core wire 11, so-called Z
twist or S twist in an opposite direction thereto may be used.
[0020] Stainless steel wires (e.g., SUS 316, SUS 304, etc., in JIS)
are used as all the six surrounding wires 12 surrounding the core
wire 11. Meanwhile, a tungsten wire is used as the core wire 11
which extends straightly in the center and is not exposed to the
outer surface.
[0021] Thus since the surrounding wires 12 which are exposed on the
surface of the miniature rope 10 are formed of stainless steel
wires excelling in wear resistance, even if they are rubbed against
a hard object, they are not easily worn. On the other hand, since
the core wire 11 which is not exposed on the surface is formed of a
tungsten wire having a high tensile strength, the core wire 11
increases the tensile strength without enlarging the outside
diameter of the miniature rope 10, and permits use in a portion
where a lard load is applied.
[0022] In addition, as a characteristic of the miniature rope 10
which is a stranded wire, if the miniature rope 10 is deflected,
only a deflecting force is applied to the core wire 11 in the
center, whereas a deflecting force and a twisting force are applied
to the surrounding wires 12 wound therearound.
[0023] In addition, a large deflecting stress is applied to the
core wire 11 as compared to the surrounding wires 12 partly because
the entire length of the core wire 11 is shorter than that of the
surrounding wires 12. For this reason, if the miniature rope 10 is
repeatedly deflected, a kink is liable to occur in the core wire
11.
[0024] Accordingly, by using the tungsten wire which makes it
difficult for the kink to occur in the core wire 11 as in this
embodiment, even if the surrounding wires 12 are the stainless
steel wires, it is possible to obtain the miniature rope 10 in
which, as a whole, the kink is difficult to occur.
[0025] It should be noted that, as a material in which the link is
difficult to occur, a superelastic alloy formed of such as a
nickel-titanium (Ni-Ti) alloy has a very excellent characteristic.
Accordingly, if the superelastic alloy is used as the material of
the core wire 11, even if the surrounding wires 12 are the
stainless steel wires or the like, it is possible to obtain the
miniature rope 10 in which the kink is very difficult to occur.
[0026] In addition, as for the nickel-titanium alloy wire, one
having a composition excelling in its tensile characteristic and
deflecting characteristic may be used as the core wire 11 even if
it is not included among the superelastic alloys.
[0027] Such a miniature rope 10 in accordance with the invention
can be used for various applications.
[0028] FIG. 3 shows an endoscope, in which a curved portion 2
connected to a distal end of an inserting portion 1 is arbitrarily
deflected by a flexible operating wire 5 which is subjected to
traction by a manipulating mechanism 4 which is disposed in a
manipulating portion 3.
[0029] During traction, a large tensile force is applied to the
flexible operating wire 5, and the flexible operating wire 5
undergoes vehement rubbing against a curved tube made of stainless
steel inside the curved portion 2. In addition, the portion of the
flexible operating wire 5 which is wound around a pulley 6 disposed
in the manipulating mechanism 4 is bent with a small radius of
curvature.
[0030] Accordingly, if the miniature rope 10 in which the
surrounding wires 12 formed of stainless steel wires are spirally
wound around the core wire 11 formed of a tungsten wire is used as
the flexible operating wire 5, it is possible to obtain extremely
excellent durability as compared with the miniature rope 10 in
which both the core wire 11 and the surrounding wires 12 are formed
of stainless steel wires.
[0031] FIG. 4 shows a snare for an endoscope which is used for the
purpose of constricting and incising a colonic polyp or the like,
and a snare loop wire 23 formed of an elastic wire is connected
through a stainless steel pipe-made connecting pipe 24 to a distal
end of an operating wire 22 inserted and disposed in a flexible
tube-made sheath 21 in such a manner as to be extendable and
retractable in the axial direction.
[0032] The snare loop wire 23 moves into and out of the sheath 21
by pulling or pushing the operating wire 22, and bulges in loop
form outside the sheath 21 by its own resiliency.
[0033] As the snare loop wire 23 is pulled into the sheath 21, the
snare loop wire 23 undergoes elastic deformation and narrows, but
when it is pushed out of the tip of the sheath 21, the snare loop
wire 23 must restore its original bulged form.
[0034] Accordingly, the snare loop wire 23 must be provided with a
characteristic that a kink is difficult to occur, so that it is
sufficient to use the miniature rope 10 in accordance with the
invention. In that case, if a superelastic alloy wire formed of a
nickel-titanium Ni-Ti alloy or the like is used as the core wire
11, since it can be safely the that practically no kink occurs in
the core wire 11, a kink hardly occurs in the snare loop wire 23.
Hence, even after the endoscope is repeatedly used, the snare loop
wire 23 is able to maintain its bulged state outside the sheath
21.
[0035] In addition, although the nickel-titanium alloy is a
material for which brazing, welding, and soldering are difficult to
perform, if stainless steel wires, for example, are used as the
surrounding wires 12, brazing, welding, soldering, or the like can
be used in connection to a member such as the connecting pipe
24.
[0036] It should be noted that the invention is not to be limited
to the above-described embodiment, the invention may be applied to
ropes of a 1.times.19 construction or 1.times.37 construction
which, as a whole, are formed as stranded wires by spirally winding
18 or 36 surrounding wires 12 around the core wire 11, or ropes
having other types of strand construction.
[0037] Furthermore, metal wires of material other than those
described above may be used as the core wire 11 and the surrounding
wires 12, and an object to which the miniature rope 10 is applied
is not to be limited to the one described above.
* * * * *