U.S. patent application number 14/614049 was filed with the patent office on 2015-06-04 for instrument and method for making the same.
The applicant listed for this patent is FORTIMEDIX SURGICAL B.V.. Invention is credited to Marcel Antonius Elisabeth VERBEEK.
Application Number | 20150151080 14/614049 |
Document ID | / |
Family ID | 39876516 |
Filed Date | 2015-06-04 |
United States Patent
Application |
20150151080 |
Kind Code |
A1 |
VERBEEK; Marcel Antonius
Elisabeth |
June 4, 2015 |
INSTRUMENT AND METHOD FOR MAKING THE SAME
Abstract
A process for producing the actuating part of an instrument for
endoscopic applications, which instrument comprises a tubular
member having a handling end portion with a flexible portion and an
actuating device located at another end portion, which actuating
device comprises a cylindrical part connected to the handling end
portion, a cylindrical part connected to the actuating device and a
number of longitudinal elements for transferring the movement of
the actuating device to the handling end portion, the actuating
device being made beginning with a full cylindrical tube which is
provided with a number of longitudinal slits thereby forming the
longitudinal elements.
Inventors: |
VERBEEK; Marcel Antonius
Elisabeth; (Heerlen, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FORTIMEDIX SURGICAL B.V. |
NUTH |
|
NL |
|
|
Family ID: |
39876516 |
Appl. No.: |
14/614049 |
Filed: |
February 4, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12921475 |
Oct 19, 2010 |
8986317 |
|
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PCT/EP2008/005319 |
Jun 30, 2008 |
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14614049 |
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Current U.S.
Class: |
606/108 |
Current CPC
Class: |
A61B 17/00234 20130101;
A61B 2017/00314 20130101; A61B 2017/00309 20130101; A61B 1/00073
20130101; A61M 25/001 20130101; A61M 25/0054 20130101; A61M 25/0013
20130101; A61B 1/0011 20130101; A61B 1/00071 20130101; A61M 25/0138
20130101; A61M 2025/0004 20130101; A61B 1/0055 20130101 |
International
Class: |
A61M 25/01 20060101
A61M025/01; A61B 17/00 20060101 A61B017/00; A61M 25/00 20060101
A61M025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2008 |
EP |
08004373.0 |
Claims
1. An instrument for endoscopic applications comprising a tube-like
member that includes three coaxial cylindrical members, namely an
inner cylindrical member, an intermediate cylindrical member, and
an outer cylindrical member; the inner cylindrical member including
a first rigid inner member end part at a handling end portion of
the instrument, a first flexible inner member part, an intermediate
rigid inner member part, a second flexible inner member part, and a
second rigid inner member end part at an actuating end portion of
the instrument; the intermediate cylindrical member having a first
rigid intermediate member end part at the handling end portion of
the instrument, and a second rigid intermediate member end part at
the actuating end portion of the instrument that is connected to
the first rigid end part via at least three longitudinal elements
that are separated by at least three longitudinal slits, each of
which longitudinal elements is connected to both the first rigid
intermediate member end part and the second rigid intermediate
member end part; the outer cylindrical member including a first
rigid outer member end part at the handling end portion of the
instrument, a first flexible outer member part, an intermediate
rigid outer member part, a second flexible outer member part, and a
second rigid outer member end part at the actuating end portion of
the instrument; the three coaxial cylindrical members being
arranged such that the longitudinal elements of the intermediate
member are arranged to control a radial deflection of the handling
end portion of the instrument by a radial deflection of the
actuating end portion of the instrument through a movement of the
longitudinal elements in a longitudinal direction; and wherein each
pair of adjacent longitudinal elements of said at least three
longitudinal elements is interconnected by at least a first
flexible bridge that is arranged at least in parts coinciding with
flexible parts of the instrument.
2. The instrument according to claim 1, said first rigid inner
member end part, said first rigid intermediate member end part and
said first rigid outer member end part being connected to each
other.
3. The instrument according to claim 1, said second rigid inner
member end part, said second rigid intermediate member end part and
said second rigid outer member end part being connected to each
other.
4. The instrument according to claim 2, said second rigid inner
member end part, said second rigid intermediate member end part and
said second rigid outer member end part being connected to each
other.
5. The instrument according to claim 1, comprising a first flexible
part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part.
6. The instrument according to claim 5, comprising a first rigid
part being arranged to interconnect said first and second flexible
parts, said first rigid part coinciding with said intermediate
rigid inner member part and said intermediate rigid outer member
part.
7. The instrument according to claim 5, wherein said at least first
flexible bridge is arranged in one of said first and second
flexible parts of the instrument.
8. The instrument according to claim 6, further comprising a second
flexible bridge that is arranged in one of said first flexible
part, said second flexible part and said first rigid part of the
instrument.
9. The instrument according to claim 1, comprising: a first
flexible part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part; a first rigid part being
arranged to interconnect said first and second flexible parts, said
first rigid part coinciding with said intermediate rigid inner
member part and said intermediate rigid outer member part; and a
second flexible bridge; wherein said at least first flexible bridge
is arranged in one of said first and second flexible parts of the
instrument, and said second flexible bridge is arranged in one of
said first flexible part, said second flexible part and said first
rigid part of the instrument.
10. The instrument according to claim 1, wherein said at least
first flexible bridge has the form of a short strip that is
arranged to extend in a circumferential direction of the tube-like
member between a pair of adjacent longitudinal elements, said short
strip having a width in a longitudinal direction of the tube-like
member which allows parallel movement of said pair of adjacent
longitudinal elements with respect to each other.
11. The instrument according to claim 1, comprising a first
flexible part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part, said at least first flexible
bridge being arranged in one of said first and second flexible
parts of the instrument, wherein said at least first flexible
bridge has the form of a short strip that is arranged to extend in
a circumferential direction of the tube-like member between a pair
of adjacent longitudinal elements, said short strip having a width
in a longitudinal direction of the tube-like member which allows
parallel movement of said pair of adjacent longitudinal elements
with respect to each other.
12. The instrument according to claim 1, comprising: a first
flexible part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part; a first rigid part being
arranged to interconnect said first and second flexible parts, said
first rigid part coinciding with said intermediate rigid inner
member part and said intermediate rigid outer member part; and a
second flexible bridge that is arranged in one of said first
flexible part, said second flexible part and said first rigid part
of the instrument; wherein at least said at least first flexible
bridge has the form of a short strip that is arranged to extend in
a circumferential direction of the tube-like member between a pair
of adjacent longitudinal elements, said short strip having a width
in a longitudinal direction of the tube-like member which allows
parallel movement of said pair of adjacent longitudinal elements
with respect to each other.
13. The instrument according to claim 1, comprising: a first
flexible part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part; a first rigid part being
arranged to interconnect said first and second flexible parts, said
first rigid part coinciding with said intermediate rigid inner
member part and said intermediate rigid outer member part; and a
second flexible bridge; said at least first flexible bridge being
arranged in one of said first and second flexible parts of the
instrument, and said second flexible bridge being arranged in one
of said first flexible part, said second flexible part and said
first rigid part of the instrument, wherein at least said at least
first flexible bridge has the form of a short strip that is
arranged to extend in a circumferential direction of the tube-like
member between a pair of adjacent longitudinal elements, said short
strip having a width in a longitudinal direction of the tube-like
member which allows parallel movement of said pair of adjacent
longitudinal elements with respect to each other.
14. The instrument according to claim 10, wherein said short strip
is provided with at least one recess for increasing a degree of
flexibility of said short strip.
15. The instrument according to claim 14, wherein said short strip
is arranged to extend under an angle with respect to the
circumferential direction of the tube-like member between a pair of
adjacent longitudinal elements.
16. The instrument according to claim 15, wherein said angle is
small.
17. The instrument according to claim 15, wherein a series of said
short strips are arranged to form a spiral.
18. The instrument according to claim 1, wherein said at least
first flexible bridge comprises two cams that are arranged to
extend between a pair of adjacent longitudinal elements and to abut
in the longitudinal slit between said adjacent longitudinal
elements; and two semicircular bands that are arranged to
interconnect said two cams.
19. The instrument according to claim 1, comprising a first
flexible part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part, said at least first flexible
bridge being arranged in one of said first and second flexible
parts of the instrument, wherein said at least first flexible
bridge comprises: two cams that are arranged to extend between a
pair of adjacent longitudinal elements and to abut in the
longitudinal slit between said adjacent longitudinal elements; and
two semicircular bands that are arranged to interconnect said two
cams.
20. The instrument according to claim 1, comprising: a first
flexible part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part; a first rigid part being
arranged to interconnect said first and second flexible parts, said
first rigid part coinciding with said intermediate rigid inner
member part and said intermediate rigid outer member part; and a
second flexible bridge that is arranged in one of said first
flexible part, said second flexible part and said first rigid part
of the instrument; wherein at least said at least first flexible
bridge comprises: two cams that are arranged to extend between a
pair of adjacent longitudinal elements and to abut in the
longitudinal slit between said adjacent longitudinal elements; and
two semicircular bands that are arranged to interconnect said two
cams.
21. The instrument according to claim 1, comprising: a first
flexible part and a second flexible part, said first flexible part
coinciding with said first flexible inner member part and said
first flexible outer member part, said second flexible part
coinciding with said second flexible inner member part and said
second flexible outer member part; a first rigid part being
arranged to interconnect said first and second flexible parts, said
first rigid part coinciding with said intermediate rigid inner
member part and said intermediate rigid outer member part; and a
second flexible bridge; said at least first flexible bridge being
arranged in one of said first and second flexible parts of the
instrument, and said second flexible bridge being arranged in one
of said first flexible part, said second flexible part and said
first rigid part of the instrument, wherein at least said at least
first flexible bridge comprises: two cams that are arranged to
extend between a pair of adjacent longitudinal elements and to abut
in the longitudinal slit between said adjacent longitudinal
elements; and two semicircular bands that are arranged to
interconnect said two cams.
22. The instrument according to claim 18, wherein said two cams are
arranged to abut about halfway in the longitudinal slit between
said adjacent longitudinal elements.
Description
BACKGROUND OF THE INVENTION
[0001] I. Technical Field
[0002] The invention relates to a process for producing the
actuating part of an instrument for endoscopic applications or the
like, which instrument comprises a tubular member having a handling
end portion with a flexible portion and an actuating means located
at another end portion, which actuating means comprises a
cylindrical part connected to the handling end portion, a
cylindrical part connected to the actuating means and a number of
longitudinal elements for transferring the movement of the
actuating means to the handling end portion.
[0003] II. Description of the Related Art
[0004] An instrument of the above described type has been described
in EP-A-1 708 609 and is normally used for applications such as
minimally invasive surgery, but it is also applicable for other
purposes such as the inspection or repair of mechanical or
electronic installations at locations which are difficult to reach.
In the detailed description, the term endoscopic applications or
endoscopic instrument will be used but the term must be interpreted
as also covering other applications or instruments as explained
above.
[0005] In this known instrument, the actuating part needed to steer
one end of the instrument by movement of the other end is made out
of a number of cables which are connected both to the first and
second end portions. Connecting the cables to these portions is
cumbersome and complicated in that each cable has to be connected
separately and the tension in the cables must be the same for all
of the cables so to obtain a reliable control of the movement. This
makes the production of such an instrument complicated.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of the invention to provide a
process for producing the actuating part of an instrument of the
above identified type in which this problem is avoided.
[0007] This object is achieved in that the actuating means is made
beginning with a full cylindrical tube which is provided with a
number of longitudinal slits thereby forming the longitudinal
elements.
[0008] By having the longitudinal elements made as an integral part
of the remaining parts of the actuating operating member, the
separate connection of the different parts of this member is
avoided and assembling becomes extremely easy.
[0009] The invention also relates to an endoscopic instrument using
an actuating means obtained by the process according to the
invention, in which different constructions are used in order to
obtain a reliable operation of the actuating means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Other advantages and characteristics of the invention will
be clear from the following description, reference being made to
the attached drawings.
[0011] In the drawings:
[0012] FIG. 1 is a schematic cross-section of an instrument
according to the invention.
[0013] FIG. 2 is an exploded view of the three cylindrical members
forming the instrument according to the invention.
[0014] FIG. 3 is an unrolled view of a part of the intermediate
cylindrical member of the instrument according to the
invention.
[0015] FIG. 4 is an unrolled view of a part of a second embodiment
of the intermediate member according to the invention.
[0016] FIG. 5 is an unrolled view of a part of a third embodiment
of the intermediate member according to the invention.
[0017] FIG. 6 is an unrolled view of a part of a fourth embodiment
of the intermediate member according to the invention.
[0018] FIG. 7 is an unrolled view of a part of a fifth embodiment
of the intermediate member according to the invention.
[0019] FIG. 8 is an unrolled view of a part of a sixth embodiment
of the intermediate member according to the invention.
[0020] FIG. 9 is an unrolled view of a part of a seventh embodiment
of the intermediate member according to the invention.
[0021] FIG. 10 is an unrolled view of a part of an eighth
embodiment of the intermediate member according to the invention in
a pre-assembled condition.
[0022] FIG. 11 is a cross-section view of the unit with an
intermediate member according to FIG. 11 in the pre-assembled
condition.
[0023] FIG. 12 is an unrolled view of a part of the eighth
embodiment of the intermediate member according to the invention in
the assembled condition.
[0024] FIG. 13 is a cross-section view of the instrument with an
intermediate member according to FIG. 10 in the assembled
condition.
[0025] FIG. 14 is an unrolled view of a part of a ninth embodiment
of the intermediate member according to the invention in a
pre-assembled condition.
[0026] FIG. 15 is an unrolled view of a part of a tenth embodiment
of the intermediate member according to the invention.
[0027] FIG. 16 is an unrolled view of a part of an eleventh
embodiment of the intermediate member according to the
invention.
[0028] FIG. 17 is a schematic exploded view of a modified
embodiment of the instrument according to the invention.
[0029] FIG. 18 is a schematic drawing of a special application of a
modified instrument according to the invention.
[0030] FIG. 19 is a schematic presentation of an unrolled view of a
first embodiment of a flexible part of a cylindrical member as
shown in FIG. 1 or 2.
[0031] FIG. 20 is an unrolled view of a second embodiment of a
flexible part of a cylindrical member as shown in FIG. 1 or 2.
[0032] FIG. 21 is an unrolled view of a third embodiment of a
flexible part of a cylindrical member as shown in FIG. 1 or 2.
[0033] FIG. 22 is a view of a flexible part as a guiding member
between two longitudinal elements as shown in FIGS. 14-16.
[0034] FIG. 23 is a view of an embodiment of a flexible part as a
guiding member as modified with respect to FIG. 22.
DETAILED DESCRIPTION OF THE INVENTION
[0035] In FIG. 1 there is shown an axial cross-section of an
instrument 1 according to the invention. The instrument 1 is
composed of three coaxial cylindrical members: an inner member 2,
an intermediate member 3 and an outer member 4. The inner
cylindrical member 2 is composed of a first rigid end part 21,
which is the part normally used at the location which is difficult
to reach or inside the human body, a first flexible part 22, an
intermediate rigid part 23, a second flexible part 24 and a second
rigid end part 25 which is normally used as the operating part of
the instrument in that it serves to steer the other end of the
unit. The outer cylindrical member 4 is in the same way composed of
a first rigid part 41, a flexible part 42, an intermediate rigid
part 43, a second flexible part 44 and a second rigid part 45. The
length of the different parts of the cylindrical members 2 and 4
are substantially the same so that when the cylindrical member 2 is
inserted into the cylindrical member 4, the different parts are
positioned against each other. The intermediate cylindrical member
3 also has a first rigid end part 31 and a second rigid end part 35
which in the assembled condition are located between the
corresponding rigid parts 21, 41 and 25, 45 respectively of the two
other cylindrical members.
[0036] From FIG. 2 it will be clear to a person skilled in the art
that a radial deflection of the handling end portion of the
instrument 1 can be caused by a radial deflection of the actuating
end portion of the instrument through a movement of the
longitudinal elements 38 in a longitudinal direction. FIG. 18
further illustrates this by the radial deflections of the handling
end portions of the instruments 203 and 204 in response to the
radial deflections of the actuating end portions of these
instruments.
[0037] The intermediate part 33 of the intermediate cylindrical
member 3 is formed by three or more separate longitudinal elements
which can have different forms and shapes as will be explained
below. After assembly of the three cylindrical members 2, 3 and 4
whereby the inner member 2 is inserted in the intermediate member 3
and the two combined members 2, 3 are inserted into the outer
member 4, the end faces of the three members 2, 3 and 4 are
connected to each other at both ends so as to have one integral
unit.
[0038] In the embodiment shown in FIG. 2 the intermediate part 33
is formed by a number of longitudinal elements 38 with a uniform
cross-section so that the intermediate part 33 has the general
shape and form as shown in the unrolled condition in FIG. 3. From
this it also becomes clear that the intermediate part is formed by
a number of equally spaced parallel longitudinal elements 38 over
the circumference of the cylindrical part 3. The number of elements
38 must be at least three, so that the instrument 1 becomes fully
controllable in any direction, but any higher number is possible as
well.
[0039] The production of such an intermediate part is most
conveniently done by injection molding or plating techniques or
starting from a regular cylindrical tube with desired inner and
outer diameters and removing these parts of the tube wall required
to end up with the desired shape of the intermediate cylindrical
member. This removal of material can be done by means of different
techniques such as laser cutting, photochemical etching, deep
pressing, conventional chipping techniques such as drilling or
milling, high pressure water jet cutting systems or any suitable
material removing process available. Preferably laser cutting is
used as this allows a very accurate and clean removal of material
under reasonable economic conditions. These are convenient ways the
intermediate member 3 can be made in one process, without requiring
additional steps for connecting the different parts of the
intermediate cylindrical member as required in the conventional
instruments, where the longitudinal members must be connected in
some way to the end parts.
[0040] The same type of technology can be used for producing the
inner and outer cylindrical members 2 and 4 with their respective
flexible parts 22, 24, 42 and 44. A tube having flexible parts can
be obtained in different ways. In FIGS. 19, 20, 21 and 22 there are
shown different ways how such flexibility in the part can be
obtained. FIG. 19 shows a schematic representation of a rolled out
flexible cylindrical portion. In the embodiment shown in FIG. 19,
the part of the cylindrical tube to become flexible has been
provided with slits 50 extending in a helical manner over the
length of the flexible part. The flexibility can be controlled by
the number of slits 50 and/or the angle of the slits 50 with
respect to the axial direction of the cylindrical member.
[0041] In the embodiment of FIG. 20, the part of the cylindrical
tube to become flexible has been provided with a number of short
slits 51. The slits 51 can be divided into groups, the slits 51 in
each group being located in the same line extending perpendicular
to the axis of the cylindrical member. The slits 51 in two
neighboring groups are offset. In the embodiment of FIG. 21, the
part of the cylindrical tube to become flexible has been provided
by making slits producing a number of swallow's tails 52 which fit
into each other as shown.
[0042] It will become obvious that other systems of providing a
flexible part in a cylindrical tube wall may be used as well. More
specifically, it is possible to use combinations of the systems
described above. Otherwise, it will also become obvious that the
advantageous process for producing such flexible parts in a
cylindrical tube as described above may be used in the production
of the intermediate part 33.
[0043] As described above in the first embodiment, the longitudinal
elements 38 are formed by a number of parallel elements equally
spaced around the circumference of the cylindrical member 3. As
shown in FIG. 3, a free space is available between each pair of
adjacent elements 38. It is possible to use longitudinal elements
38 as shown in this figure, but in the flexible parts of the
instrument there will be a tendency of the longitudinal elements 38
to move in a tangential direction especially when strong curves
have to be made. As a consequence of this uncontrolled movement of
the longitudinal elements 38, the accuracy and the magnitude of the
control of the position of the one end portion by the movement of
the other end portion may be lost or become more complicated. This
problem can be avoided by making longitudinal elements 38 in such a
way that the free space between two adjacent elements 38 is as
small as possible or completely left out so that two adjacent
longitudinal elements 38 are touching each other and serve as a
guide for each other. A disadvantage of this system however is that
a large number of longitudinal elements 38 must be present, as the
cross section of these elements must be chosen in such a way that
their flexibility in any direction is almost the same independent
of the direction of bending. As the wall thickness of the
cylindrical member is relatively small compared to the overall
dimensions of the cylindrical member especially with respect to the
circumference, this will result in a large number of longitudinal
elements 38 as seen along the tangential direction and an increase
of total bending stiffness. As the longitudinal elements 38 are
touching each other in the tangential direction, this provides for
a guiding of these elements upon use of the instrument.
[0044] In a modified embodiment of the longitudinal elements this
problem has been avoided in a different way. In this second
embodiment shown in FIG. 4 each longitudinal element 60 is composed
of three portions 61, 62 and 63, co-existing with the first
flexible portion 22, 42, the intermediate rigid portion 23, 43 and
the second flexible portion 24, 44 respectively. In the portion 62
coinciding with the intermediate rigid portion, each pair of
adjacent longitudinal elements 60 is touching each other in the
tangential direction so that in fact only a narrow gap is present
therebetween just sufficient to allow independent movement of each
longitudinal element.
[0045] In the other two portions 61 and 63 each longitudinal
element consists of a relatively small and flexible strip 64, 65 as
seen in circumferential direction, so that there is a substantial
gap between each pair of adjacent strips, and each strip 64, 65 is
provided with a number of cams 66, extending in circumferential
direction and almost completely bridging the gap to the next strip.
Because of these cams the tendency of the longitudinal elements in
the flexible portions of the instrument to shift in circumferential
direction is suppressed and the direction control is complete. The
exact shape of these cams 66 is not very critical, provided they do
not compromise flexibility of strips 64 and 65. In view thereof,
any shape like a trapezium shape as shown in FIG. 4 is
applicable.
[0046] In the embodiment shown in FIG. 4, the cams 66 are extending
towards one direction as seen from the strip to which they are
connected. It is however also possible to have these cams extending
to both circumferential directions starting from one strip. By
using this it is either possible to have an alternating type of
strips as seen along the circumference, a first type provided at
both sides with cams 66 extending until the next strip, or a second
intermediate set of strips without cams. Otherwise it is possible
to have strips with cams at both sides, where as seen along the
longitudinal direction of the instrument the cams originating from
one strip are alternating with cams originating from the adjacent
strips. It is obvious that numerous alternatives are available. It
is important that adjacent strips are in contact with each but that
the flexibility of strips 64 and 65 is not compromised.
[0047] In FIG. 5 there is shown a third embodiment of the
longitudinal elements as may be used according to the invention. In
this embodiment, the longitudinal elements 70 are formed by strips
71 comparable to the strips 38 of FIG. 3 interconnecting the
portions 31 and 33. Furthermore, the strips 71 have been provided
with cams 72 so that the strips 71 are almost comparable to the
strips 61 or 63 of FIG. 4. In this way a guiding is provided by the
cams 72 over the complete length of the strips 71. It is obvious
that in this case the modifications with respect to the position of
the cams 72 and the alternating of strips 71 with cams on both
sides and strips without cams as described above with respect to
FIG. 4 are also applicable for this embodiment.
[0048] In the fourth embodiment shown in FIG. 6, the longitudinal
elements 80 are formed by strips 81 interconnecting the portions 31
and 35. These strips are comparable to the strips 38 in FIG. 3 and
have substantially the same width. This means that between each
pair of adjacent strips 81 there is left a circumferential gap 82.
Each gap 82 is filled substantially by means of another strip 83,
having a circumferential width slightly smaller than the
circumferential width of the gap 82 and a longitudinal dimension
which leaves some play between the ends of the axial ends of the
strip 83 and the portions 31 and 35 respectively. The strip 85 is
composed of three parts, a first flexible part 84, schematically
represented with dotted lines, an intermediate part 85 and a second
flexible part 86, the three parts coinciding with the flexible
parts 22,42, the intermediate parts 23, 43 and the flexible parts
24, 44 respectively of the instrument. The flexibility of the parts
84 and 86 may be obtained by any system described above, or as
shown in FIGS. 22 and 23. The intermediate part 85 is connected to
the strip 81. In this way the strip 85 is guiding the movement of
the strips 81 in the flexible portions of the instrument, without
hindering their longitudinal movement.
[0049] In the embodiment shown, each strip 81 is on one side
connected to a strip 83. As an alternative it is also possible to
have a system in which as seen along the circumference of the
intermediate cylindrical member this member is composed of a first
set of strips 81 having both sides connected to a strip 83, and a
second set of strips 81 which have no connection to such strips 83
and are as such comparable to the strips 38 of FIG. 3. It is of
course obvious that other solutions are available by using
combinations of strips 81 having either no, one or two connections
to strips 83 by putting them in the right sequence along the
circumference of the intermediate cylindrical member.
[0050] A fifth embodiment has been shown in FIG. 7. In this
embodiment, each longitudinal element 90 is composed of a first
strip 91, a band 92 and a second strip 93. The first and second
strips 91 and 93 each have a circumferential width such that there
is a circumferential gap 94 and 95 respectively between each pair
of adjacent strips 91 and 93 respectively. The bands 92 have a
circumferential width such that two adjacent bands are in contact
with each other. The strips 91 and 93 coincide with the flexible
portions 22, 42 and 24 and 44 respectively whereas the bands 92
coincide with the intermediate portion 23, 43. In each gap 94 and
95 respectively, plates 96 and 97 are placed which plates 96, 97
have a circumferential width filling the width of the gap 94, 95
and thus providing a guiding for the strips 91 and 93 respectively.
Free movement of the strips is achieved in that in the longitudinal
direction there is some play between the axial ends of the plates
96, 97 and the portion 31, the bands 92 and the portion 35
respectively.
[0051] The plates 96, 97 are completely free to move in their
respective gaps 94, 95 respectively, but because of the selected
dimensions only a movement in longitudinal direction is available.
For the production of such a system as shown in FIG. 7 it is
possible to first make the intermediate cylindrical elements by
means of one of the production techniques described above, which
results in an intermediate cylindrical member which is different
from the one shown in FIG. 7 in that one point of each plate 96 and
97 is still connected either to an adjacent strip, to a band, or to
the portions 31 or 35. In this form, the instrument is assembled
whereby the connection point between the plates 96 or 97 and the
remainder of the intermediate cylindrical member coincides with a
hole provided in the cylindrical member 4. Once the assembling is
finished, the connection mentioned above can be destroyed, for
example by using one of the production techniques mentioned above.
In this way, the plates 96, 97 become completely freely movable in
their gaps. Here once more it will become obvious that the laser
technology is very effective in this production step.
[0052] In FIG. 8, there is shown a sixth embodiment of the
intermediate cylindrical member according to the invention. This
embodiment is very similar to the embodiment shown in FIG. 7, in
that the longitudinal elements 100 are composed of strips 101 and
103 comparable to the strips 91 and 93, and a band 102 comparable
to the band 92. In the same way, the gaps 104 and 105 are
comparable to the gaps 94 and 95, and are occupied by plates 106
and 107, which are comparable to the plates 96 and 97. In this
embodiment, the plates 106 and 107 are not completely free from the
remainder of the instrument, but each plate 106 and 107 is
connected either to the outer cylindrical member 4 or to the inner
cylindrical member 2, especially in the non-flexible part thereof.
In the embodiment shown, this is achieved by welding at one point,
108 and 109 respectively, the plates 106 and 107 to the
intermediate rigid portion of either the inner or outer cylindrical
member 2 or 4. In this way, the strips 101 and 103 are accurately
guided by the plates 106 and 107 in the flexible portions of the
instrument, but the plates 106 and 107 are not free to move whereby
the control of movement is improved and the assembling of the
instrument becomes much easier.
[0053] The seventh embodiment, shown in FIG. 9 can be seen as a
combination of the embodiment of FIG. 6 and the embodiment of FIG.
8. The longitudinal element 110 consists of a number of strips 111,
comparable to the strips 81 and the gap 112 between each pair of
adjacent strips 111 is occupied by a strip or plate 113 comparable
to strip 83. In this embodiment the strips 113 are not connected to
the strips 111 as in the embodiment of FIG. 6, but are connected at
some points 115, 116 to the rigid intermediate part of either the
outer or inner cylindrical member 2 or 4 of the instrument
comparable to the embodiment of FIG. 8.
[0054] In FIGS. 10, 11, 12 and 13 there is shown an embodiment of
the instrument which can be seen as a modification of the
embodiment shown in FIG. 9. In FIGS. 10 and 11 there is shown a
situation before assembly whereas FIGS. 12 and 13 show the
assembled instrument.
[0055] In FIGS. 10 and 11 there is shown the outer cylindrical
element 4, which is composed of three parts, a part 121 forming the
first flexible portion 42 and the first rigid portion 41, a part
122 forming the intermediate rigid portion 43 and also forming the
guiding plates 124 comparable to the guiding plates 106, 107 in
FIG. 8 and a part 123 forming the second flexible part 44 and the
second rigid part 45.
The parts 121 and 123 are simple cylindrical tubes which have been
provided with a flexible portion by one of the methods described
above. The intermediate portion 122 is formed by a cylindrical tube
in which, by one of the processes described above for removal of
material, a number of tongues 124 have been made flexible by one of
the methods described above. These tongues extend from both ends of
a central portion and form bands which occupy the space between
strips like the strips 111. Therefore the tongues are deformed at
their connection with the central portion 125 so as to have a
smaller diameter whereby these tongues fit into the spaces between
the strips. In fact the tongues are deformed to form internal and
external diameters substantially equal to the corresponding
diameters of the strips.
[0056] After the different parts 121, 122 and 123 are produced as
described, the parts 121 and 123 are moved over the tongues 124 and
the respective abutting ends of the parts 121 and 123 are welded to
the central portion 125 so as to form the external cylindrical
member 4.
[0057] In FIGS. 14, 15 and 16 there is shown a different category
of embodiments of longitudinal elements 130 interconnecting the
portions 31 and 35 of the intermediate cylindrical member 3. The
longitudinal elements 130 are formed by strips 131 comparable to
the strips 38 of FIG. 3. As seen in the circumferential direction
of the cylindrical member, these strips are spaced apart from each
other by a gap 132. At least in the flexible zone of the instrument
where a guiding of the strips is preferred or required, each pair
of adjacent strips is connected by a number of bridges which have a
defined degree of flexibility as seen in the longitudinal
direction. These bridges extend the width of the gap 132 and can be
shaped in different ways.
[0058] In the embodiment of FIG. 14, the bridges have the form of
short strips 134 extending in the circumferential direction and
having a width in the longitudinal direction which allows some
parallel movement from one strip 131 to an adjacent strip 131. By
selection of the number of short strips 134 and the cross-sectional
dimensions thereof, the flexibility of the short strips 134 may be
sufficient to allow sufficient freedom of movement of the adjacent
strips 131. If needed, the flexibility of the short strips 134 can
be enhanced by applying some special configurations as shown in
FIGS. 23, 24 and 25. The short strips 134 need not transfer any
tangential force from one strip 131 to the adjacent strip 131, but
serve only to maintain the distance between two adjacent strips
131.
[0059] In the embodiment shown in FIG. 15, the strips 135 are
shaped with some recesses so as to increase their flexibility.
Moreover these strips 135 have been not directed along the
circumferential direction of the cylindrical member, but are
positioned under a small angle with respect to the circumferential
direction in a way that the series of connectors form a spiral. A
special shape of the bridges is shown in the embodiment of FIG. 16.
The bridges 136 of this embodiment consist of two cams 137 and 138
extending from two adjacent strips 131 and abutting about halfway
in the gap between the two strips. Two semicircular bands 139 and
140 connect the two cams 137 and 138. This provides a high degree
of flexibility while the distance between the two adjacent strips
is accurately maintained. The making of such bridges 136 does not
present any special problems when using one of the techniques
described above.
[0060] In FIG. 17, there is shown a special embodiment of an
instrument according to the inventions. The inner cylindrical
member is composed of a first rigid end part 141, a first flexible
part 142, an intermediate rigid part 143, a second flexible part
144 and a second rigid end part 145 which is normally used as the
operating part of the instrument in that it serves to steer the
other end of the unit. The outer cylindrical member is in the same
way composed of a first rigid part 161, a flexible part 162, an
intermediate rigid part 163, a second flexible part 164 and a
second rigid part 165. The intermediate cylindrical member also has
a first rigid end part 151 and a second rigid end part 155 which in
the assembled condition are located between the corresponding rigid
parts 141, 161 and 145, 165 respectively of the two other
cylindrical members. In the embodiment shown the longitudinal
elements 153 are of the type shown in FIG. 3, but it will become
obvious that any other type described above may be used as well. So
far the construction is comparable to the instrument shown in FIG.
1.
[0061] The main difference with respect to the embodiment of FIG. 1
consists in the use of a different set of diameters for some parts
of the instrument. In the embodiment shown, the parts 144, 145,
155, 164 and 165 have a larger diameter than the other parts and in
the parts 143, 153 and 163 a frusto-conical portion is formed in
order to connect the smaller diameter parts with the larger
diameter parts. As shown in FIG. 17, the different parts can easily
be assembled by inserting one into the other. The main reason
however to have such an instrument with different diameters is that
by using an operating part with a larger diameter, the movement of
the other end is amplified, whereas if a smaller diameter is used
the movement of the other end is reduced. Depending on the
application and its requirements, larger diameters can be used to
provide the amplified movement or smaller diameters can be used to
reduce the movement and increase accuracy.
[0062] A special application of the instrument according to the
invention is shown in FIG. 18. In this application, a number of
tubes have been inserted into a body of an environment where some
inspection or treatment must take place. In the embodiment shown
there are three tubes including a first or central tube 200, which
may be a straight tube which is used for illumination and viewing
purposes. Two S-shaped tubes 201 and 202 are positioned partly
against this central tube 200, and these tubes are used for the
guiding of instruments 203 and 204 according to the invention. The
bending is necessary to have the handling side of the instruments
203 and 204 removed from each other and from the central tube 200
so that the movement is possible in any direction. By positioning
the S-shaped tubes diametrically in opposition to the central tube
200, there is also sufficient space left at the working side to
perform all kinds of movement of these ends of the instruments 203
and 204.
[0063] In order to enable the instruments to be guided through such
an S-shaped tube 201 or 202 or a tube with any curved shape, the
intermediate rigid portion of the instruments 203 and 204 is
provided with at least one additional flexible portion dividing the
intermediate portion in rigid portions of a lesser length so as to
allow some additional bending. If needed, more than one
intermediate flexible portion may be included.
[0064] It is obvious that the invention is not restricted to the
described embodiments as shown in the attached drawings, but that
within the scope of the claims modifications can be applied without
departing from the inventive concept.
* * * * *