U.S. patent application number 11/809696 was filed with the patent office on 2007-10-11 for selectively rotatable shaft coupler.
This patent application is currently assigned to SCIMED Life Systems, Inc.. Invention is credited to Dennis R. Boulais.
Application Number | 20070238926 11/809696 |
Document ID | / |
Family ID | 35539432 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070238926 |
Kind Code |
A1 |
Boulais; Dennis R. |
October 11, 2007 |
Selectively rotatable shaft coupler
Abstract
In one aspect, the present invention is a system for rotatably
coupling a shaft to a housing. The system includes a selectively
rotatable shaft coupler that connects a shaft to a housing that
allows a limited amount of shaft rotation, but which sets a
restriction on the maximum amount of shaft rotation. In another
aspect, the invention provides a shaft coupling system for
connecting a proximal end of an endoscope shaft to a housing
without the use of adhesive or epoxies.
Inventors: |
Boulais; Dennis R.;
(Danielson, CT) |
Correspondence
Address: |
KLARQUIST SPARKMAN, LLP;One World Trade Center
Suite 1600
121 S.W. Salmon Street
Portland
OR
97204
US
|
Assignee: |
SCIMED Life Systems, Inc.
|
Family ID: |
35539432 |
Appl. No.: |
11/809696 |
Filed: |
June 1, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10955960 |
Sep 30, 2004 |
7241263 |
|
|
11809696 |
Jun 1, 2007 |
|
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|
Current U.S.
Class: |
600/137 |
Current CPC
Class: |
A61B 1/00128 20130101;
Y10T 403/32213 20150115; A61B 1/00124 20130101; Y10T 403/32983
20150115; Y10T 403/32975 20150115 |
Class at
Publication: |
600/137 |
International
Class: |
A61B 1/00 20060101
A61B001/00 |
Claims
1. A system for rotatably coupling a shaft to a housing, the system
comprising: i) a shaft adapter having a rotatably securable hollow
body with a first end adapted to be secured to an end of a shaft
and a second end adapted to be rotatably attached to a collar; ii)
a collar extending from the housing that rotatably receives the
shaft adapter; and iii) at least one stop element capable of
limiting the rotation of the shaft adapter with respect to the
housing.
2. The system of claim 1, wherein the stop element is located on
the shaft adapter.
3. The system of claim 2, wherein the stop element is a circular
flange.
4. The system of claim 3, further comprising a bore within the
collar and a cap secured over the bore such that the flange is
movable in the bore by rotation of the shaft.
5. The system of claim 1, wherein at least a portion of the collar
is threaded.
6. The system of claim 5, comprising at least two stop elements
located on the collar, wherein the space between the stop elements
determines the range of shaft rotation.
7. The system of claim 6, further comprising an engagement element
located on the shaft adapter body, wherein the engagement element
rides in the grooves of the threaded collar, wherein rotation of
the shaft adapter in the collar causes axial movement of the shaft
adapter along the collar until the engagement element contacts the
first or second stop element.
8. The system of claim 5, comprising at least one stop element
located on the collar, limiting rotation of the endoscope shaft in
a first direction and wherein the depth of the threads on the
collar limits rotation of the shaft in a second direction.
9. A system for rotatably coupling a shaft to a housing while
maintaining the effective length of the shaft during rotation, the
system comprising: (i) a shaft adapter having a hollow body with a
first end adapted to be secured to an end of a shaft, a second end
adapted to be slidably connected to a rotary adapter, and a
circular flange adjacent to the first end; (ii) a collar extending
from the housing with a first end adapted to receive the flange on
the shaft adapter and a threaded lumen with a first stop element
and a second stop element, wherein the first stop element and the
second stop element are spaced apart from one another at a
predetermined width inside the collar; and (iii) a rotary adapter
having a hollow body with a first end adapted to slidably connect
to the second end of the shaft adapter and a second end comprising
an engagement element, wherein the engagement element rides inside
the threads of the collar, wherein rotation of the rotary adapter
in the threaded collar causes incremental movement of the rotary
adapter along the collar lumen until either the engagement element
contacts the first stop element on the collar, limiting further
rotation in the clockwise direction, or until the engagement
element contacts the second stop element on the collar, limiting
further rotation in the counterclockwise direction, wherein the
effective length of the shaft is maintained during rotation.
10. The system of claim 9, wherein the shaft adapter and the rotary
adapter are slidably connected with interfacing tangs and
notches.
11. The system of claim 9, wherein the shaft adapter and the rotary
adapter are slidably connected with interfacing grooves and
ribs.
12. A system for rotatably coupling a shaft to a housing while
maintaining the effective length of the shaft during rotation, the
system comprising: a shaft having a proximal end and a distal end
and one or more lumens therein; a housing; a threaded collar
attached to the housing; means for rotatably coupling the shaft to
the housing; and means for selectively rotating the shaft with
respect to the housing, wherein the effective length of the shaft
is maintained during rotation.
13. The system of claim 12, wherein the means for rotatably
coupling the shaft to the housing includes a shaft adapter sized to
rotate in the threaded collar, the shaft adapter having a first end
adapted to be secured to the proximal end of the shaft, a second
end adapted to slidably connect to a rotary adapter and means to
prevent axial motion of the shaft.
14. The system of claim 13, wherein the means for selectively
rotating the shaft with respect to the housing includes a rotary
adapter intermediate the shaft adapter and the housing having a
hollow body with a first end adapted to slidably connect to the
second end of the shaft adapter, wherein the shaft adapter and the
rotary adapter cooperate to limit rotation of the shaft.
15. The system of claim 14, wherein the rotary adapter comprises an
engagement element adapted to engage the threads of the collar.
16. The system of claim 15, wherein the threaded collar has at
least one stop element.
17. A system for rotatably coupling a shaft to a housing, the
system comprising: a shaft; a housing; a shaft adapter and a rotary
adapter; wherein the housing comprises a threaded collar extending
therefrom; wherein the shaft adapter and rotary adapter are sized
to fit inside the collar; wherein a first end of the shaft adapter
is rotatably attached to one end of the shaft; wherein the rotary
adapter is intermediate the shaft adapter and the housing and
wherein the shaft adapter and rotary adapter cooperate to
maintaining the effective length of the shaft.
18. A shaft coupling system for coupling an endoscope shaft to a
housing, the system comprising: (i) a housing with a first end
adapted to receive a shaft retainer; (ii) the shaft retainer
comprising a plurality of retention barbs capable of securing an
end of the endoscope shaft.
19. The system of claim 18, wherein the plurality of retention
barbs include inward rearwardly extending barbs that are capable of
securing an end of the endoscope shaft and outwardly extending
barbs capable of securing the shaft retainer in the housing.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to shaft couplers for medical
devices in general and to rotatable shaft couplers in
particular.
BACKGROUND OF THE INVENTION
[0002] It has become well established that there are major health
benefits from regular endoscopic examinations of a patient's
internal structures such as the alimentary canals and airways,
e.g., the esophagus, stomach, lungs, colon, uterus, urethra,
kidney, and other organ systems. Endoscopes are also commonly used
to perform surgical, therapeutic, diagnostic or other medical
procedures under direct visualization. A conventional imaging
endoscope used for such procedures generally include an
illuminating mechanism such as a fiber optic light guide connected
to a proximal source of light, and an imaging means such as an
imaging light guide to carry an image to a remote camera or eye
piece or a miniature video camera within the endoscope itself. In
addition, most endoscopes include one or more working channels
through which medical devices such as biopsy forceps, snares,
fulguration probes and other tools may be passed in order to
perform a procedure at a desired location in the patient's
body.
[0003] In connection with the endoscope, an operator control module
is typically provided that allows a user to control and steer the
operation of the endoscope. The endoscope is guided through the
patient's tract or canal until an opening at the distal end of the
endoscope is proximate to the area of the patient's body which is
to be examined or receive treatment. At this point, the endoscope
allows other components, such as a catheter, to access the targeted
area.
[0004] In many endoscope procedures, the physician or operator
needs to rotate an endoscope shaft in order to obtain the desired
images, to obtain a desired position of the distal tip, or to
perform a desired surgical function (e.g. polyp removal, drainage,
and the like). An endoscope shaft with low torque transfer
characteristic allows for shaft rotation by allowing the shaft to
twist around its central axis; however, excessive rotation of the
shaft can damage the cables, tubes and electrical wires within the
shaft. On the other hand, an endoscope shaft that is not allowed to
rotate at all may loop over itself during clinical use, causing
damage to the internal components as well as discomfort to the
patient.
SUMMARY OF THE INVENTION
[0005] To address these and other problems, in one aspect the
present invention is a system for rotatably coupling a shaft to a
housing. The system includes a selectively rotatable shaft coupler
that connects a shaft to a housing that allows a limited amount of
shaft rotation, but which sets a restriction on the maximum amount
of shaft rotation. The rotatable shaft coupler comprises a shaft
adapter having a rotatably securable hollow body with a first end
adapted to be secured to an end of a shaft and a second end adapted
to be rotatably attached to a collar. A collar extends from a
housing that rotatably receives the shaft adapter. At least one
stop element is provided that is capable of limiting the rotation
of the shaft adapter with respect to the housing.
[0006] In another aspect, the present invention provides a
selectively rotatable shaft coupler that attaches an endoscope
shaft to a housing and maintains the effective length of the
endoscope shaft during rotation. The rotatable shaft coupler
comprises a shaft adapter having a hollow body with a first end
adapted to be secured to an end of a shaft, a second end adapted to
be slidably connected to a rotary adapter, and a circular flange
adjacent to the first end. A collar extends from the housing with a
first end adapted to receive the flange on the shaft adapter and a
threaded lumen with a first stop element and a second stop element,
wherein the first stop element and the second stop element are
spaced apart from one another at a predetermined width inside the
collar. A rotary adapter is provided with a hollow body having a
first end adapted to slidably connect to the second end of the
shaft adapter and a second end comprising an engagement element.
The engagement element rides inside the threads of the collar, and
rotation of the rotary adapter in the threaded collar causes
incremental movement of the rotary adapter along the collar lumen
until either the engagement element contacts the first stop element
on the collar, limiting further rotation in the clockwise
direction, or until the engagement element contacts the second stop
element on the collar, limiting further rotation in the
counterclockwise direction.
[0007] In another aspect, the present invention provides a shaft
coupling system for connecting a proximal end of an endoscope shaft
to a housing or other structure without the use of adhesive or
epoxies. The shaft coupling system comprises a housing with a first
end adapted to receive a shaft retainer and a shaft retainer
comprising a plurality of retention barbs capable of securing an
end of an endoscope shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
become better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0009] FIG. 1 is a diagram illustrating a selectively rotatable
shaft coupler in accordance with one embodiment of the
invention;
[0010] FIG. 2 shows a cross-sectional view of a shaft adapter that
is included in the shaft coupler shown in FIG. 1;
[0011] FIG. 3A is a diagram illustrating the selectively rotatable
shaft adapter of FIG. 2 shown in a position of maximum rotation in
a first direction;
[0012] FIG. 3B shows the selectively rotatable shaft adapter of
FIG. 2 shown in a position of minimal endoscope shaft rotation;
[0013] FIG. 3C shows the selectively rotatable shaft adapter of
FIG. 2 coupled to an endoscope shaft showing maximum rotation in a
second direction;
[0014] FIG. 4 illustrates another embodiment of a selectively
rotatable shaft coupler in accordance with the present
invention;
[0015] FIG. 5 illustrates another embodiment of a selectively
rotatable shaft coupler that maintains the effective length of an
endoscope shaft during rotation, in accordance with another
embodiment of the present invention;
[0016] FIG. 6 shows a perspective view of the interface between the
tangs and notches on interconnecting members of the shaft adapter
shown in FIG. 5;
[0017] FIG. 7 illustrates yet another embodiment of a selectively
rotatable shaft coupler that maintains the effective length of the
endoscope shaft during rotation, in accordance with the present
invention;
[0018] FIG. 8A shows a perspective view of a shaft adapter having
grooves along the longitudinal axis in accordance with one
embodiment of the present invention;
[0019] FIG. 8B shows a perspective view of the interface between
the shaft adapter having grooves and a rotary adapter having
corresponding ribs, in accordance with one embodiment of the
present invention;
[0020] FIG. 9 shows a selectively rotatable shaft coupler having a
non-rotatable shaft adapter in accordance with one embodiment of
the present invention;
[0021] FIG. 10A illustrates a shaft retainer having inward and
outward facing barbs, in accordance with another embodiment of the
invention;
[0022] FIG. 10B shows a perspective view of the shaft retainer
having inward and outward facing barbs in accordance with one
embodiment of the invention;
[0023] FIG. 11A illustrates an alternative embodiment of a shaft
retainer having anti-rotation bosses coupled to a breakout box
housing; and
[0024] FIG. 11B shows a perspective view of the shaft retainer
having anti-rotation bosses in accordance with one embodiment of
the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] To address the problems associated with excessive endoscope
shaft rotation, the present invention is a system for rotatably
coupling a shaft to a housing. The system comprises a selectively
rotatable shaft coupler that allows a limited amount of device
(e.g., endoscope) shaft rotation, but which sets a restriction on
the maximum amount of shaft rotation in order to provide increased
manipulation of the endoscope while protecting the internal
components of the shaft. Although the present invention is
described as allowing rotation of an endoscope, it will be
appreciated that the invention is useful with catheters, sheaths or
other devices that are inserted into a patient, wherein selective
rotation of a shaft with respect to another part of the device is
desired.
[0026] The shaft coupler system of the present invention comprises
at least one selectively rotatable shaft adapter that connects the
endoscope shaft to a connector that is secured to the device to
which the shaft is to be rotatably connected. In one embodiment,
the shaft coupler system comprises one selectively rotatable shaft
coupler positioned either proximal an endoscope connector or at a
breakout box as described in U.S. patent application Ser. No.
10/811,781, filed Mar. 29, 2004, and a continuation-in-part patent
application entitled VIDEO ENDOSCOPE, filed Sep. 30, 2004, and
identified by Attorney Docket No. BSEN-1-23550, are herein
incorporated by reference. In another embodiment, the shaft coupler
system comprises a first rotatable shaft coupler positioned at one
end of the shaft and a second rotatable shaft coupler positioned at
the other end of the shaft to provide an increased rotational
range.
[0027] FIG. 1 illustrates an exemplary embodiment of a selectively
rotatable shaft coupler 100 for connecting an endoscope shaft (not
shown) to a proximal connector housing 102. In the embodiment
shown, the proximal connector housing 102 is rigidly secured to a
retainer wall of another object to which. the endoscope is to be
rotatably secured. The proximal connector housing has a threaded
bore 104 into which a corresponding threaded end 110 of a shaft
adapter 708 is inserted. The proximal connector also includes an
outwardly extended threaded nipple 106 having a smooth bore 107
therein. The proximal connector housing 102 may be secured to the
retainer wall by a variety of means such as an adhesive, or with
any suitable fastener, or may be integrally formed with the
retainer wall. The depth of the bore 107 determines the maximum
range of endoscope shaft rotation.
[0028] A shaft adapter 108 has a distal threaded end 110 that is
threaded within the connector housing 102 and a proximal end that
is secured to an end of the endoscope. Between the distal and
proximal ends of the shaft adapter is a circular flange 114. A cap
116 is threaded onto the nipple 106 to close the flange 114 in the
bore 107. The shaft coupler 100 comprising the shaft adapter 108
and the connector housing 102 may be packaged as a preformed unit
that is removably attached to a housing or to any desired object
with any suitable connection means.
[0029] FIG. 2 shows a cross-sectional view of the shaft adapter
108. As shown, the shaft adapter 108 has a hollow body with a first
end 110 adapted to be threaded with the proximal connector 102 and
a second end 112 adapted to be secured to the end of an endoscope.
As shown, the shaft adapter body has a central hollow lumen through
which control cables and other elements of the endoscope are passed
to allow electrical, irrigation and aspiration connections to
extend into the endoscope. A counter-bored detail 120 inside the
second end 112 of the shaft adapter 108 receives an end of an
endoscope shaft. Alternatively, the second end of the shaft adapter
may be sized to fit inside an end of an endoscope shaft and secure
the shaft by any suitable means, such as with the use of an
adhesive and/or any suitable fastener.
[0030] FIGS. 3A-C illustrate the rotational movement of the shaft
adapter 108 in the proximal connector housing 102 when coupled to a
rotating endoscope shaft 122. In operation, as shown in FIG. 3A, an
end of an endoscope shaft 122 is first secured to the proximal end
of the shaft adapter, causing the shaft adapter 108 to rotate along
with the endoscope shaft 122. Rotation of the shaft 122 in a first
direction (e.g. clockwise) causes axial movement of the shaft
adapter 108 until the flange 114 is moved towards the bottom of the
bore 107 by the threads on the distal end 110 of the shaft adapter
108. As shown in FIG. 3B, the flange 114 is in an intermediate
position in the cylindrical bore 107, indicating a midway rotation
of the endoscope shaft 122. Finally, as shown in FIG. 3C, rotation
in a full counterclockwise direction causes axial movement of the
shaft adapter 108 towards the cap 116 until the flange 114 in the
bore 107 contacts the interior surface of the cap 116. The depth of
the bore 107 and the width of the flange 114 and/or the pitch of
the threads that secure the shaft adapter 108 to the proximal
connector housing 102, may be adjusted to allow for various amounts
of rotational motion of the shaft.
[0031] FIG. 4 is a partial cutaway view of another embodiment of a
selectively rotatable shaft coupler 120 attached to, for example, a
proximal connector housing 124. As shown, an internally threaded
collar 126 extends from, or is attached to the proximal connector
housing 124. A shaft adapter 132 is secured to an end of an
endoscope shaft 136 and an engagement element such as a pin 134 is
sized to be received in the grooves 128 of the threaded collar 126.
In operation, the engagement pin 134, or other equivalent
engagement element on the shaft adapter 132 rides in the grooves
128 of the threaded collar 126, causing the shaft adapter 132 to
move axially in and out of the collar during rotation of the
endoscope shaft 136. To limit rotation of the shaft, at least two
stop elements 130A,B are positioned to extend into. the threads 128
of the threaded collar to prevent movement of the engagement pin
134. The location of each of the two stop pins 130A,B in the
threads determines the range of endoscope shaft rotation.
[0032] In some embodiments, the stop elements 130A,B may be
tightened onto the shaft adapter 132, thereby locking the endoscope
shaft 136 into a desired orientation during clinical use. Although
the embodiment shown uses two stop pins 130A,B, it will be
appreciated that a single stop pin could be used by limiting the
depth of the threads in the collar 126.
[0033] Similarly, although the embodiment shown in FIG. 4 is
described with reference to stop elements as pins, those of skill
in the art will understand that the stop elements may comprise any
suitable structure capable of preventing the rotation of the shaft
adapter 132 in the collar 126, such as blocks, tabs and the like.
Similarly, those of skill in the art will understand that a
suitable engagement element is not limited to a pin, but also
includes any structure capable of allowing rotation in the collar
126 such as tabs, blocks, a smaller threaded section, and the
like.
[0034] In another aspect, the present invention provides a
selectively rotatable shaft coupler that attaches an endoscope
shaft to a housing and maintains the effective length of the
endoscope shaft during rotation. FIG. 5 is a partial cutaway view
of another embodiment of a selectively rotatable shaft coupler 140
that extends from, or is attached to, for example, a proximal
connector housing 142 in accordance with this aspect of the
invention. As shown, an internally threaded collar 144 extends from
and is integrally formed with, or is attached to the housing 142.
An endoscope shaft 170 is secured to a first end of a shaft adapter
150. A second end of the shaft adapter 150 has alternating tangs
and notches that slidably engage a corresponding set of tangs and
notches on a rotary adapter 156. A circular flange 18O on the shaft
adapter 150 is rotatably fitted in an annular slot 182 that extends
around the interior of the collar 144.
[0035] An engagement pin 158 on the rotary adapter 156 rides in the
threaded grooves 146 of the collar 144 and causes the rotary
adapter 156 to move axially in and out of the collar 144 during
rotation of the endoscope shaft 170. To limit rotation of the
shaft, stop elements 148A,B extend into the grooves 146 of the
threaded collar 144, to prevent further rotation of the engagement
pin 158. The location of each of the two stop pins 148A,B
determines the range of endoscope shaft rotation.
[0036] FIG. 6 illustrates the interlocking elements on the shaft
adapter 150 and the rotary adapter 156 in the selectively rotatable
shaft coupler 140. As shown, the first end of the shaft adapter 150
is adapted to be secured to the endoscope shaft 170 and the second
end has two opposing tangs 152A,B alternating with two opposing
notches 154A,B. The rotary adapter 156 has a corresponding set of
tangs 162A,B and notches 160A,B which fit within the notches 154A,B
and tangs 152A,B of the shaft adapter 150, respectively. As the
rotary adapter 156 is rotated in the threaded collar 144, the
rotary adapter and the shaft adapter separate or are faced closer
together because the shaft adapter is held by the circular flange
182 in the annular slot. The length of the tangs and notches are
chosen to allow continued slideable engagement through the desired
range of endoscope shaft rotation.
[0037] Referring now to FIG. 5, in operation, the rotation of the
endoscope shaft 170 causes the flange 180 on the shaft adapter 150
to rotate in the annular slot 182 in the collar 144. During
rotation of the shaft adapter 150, the tangs on the shaft adapter
engage in the notches of the rotary adapter, causing the rotary
adapter 156 to rotate along with the endoscope shaft 170. As the
rotary adapter 156 rotates in a first direction (e.g. Clockwise),
the engagement pin 158 moves along the grooves 146 of the threaded
collar 144, causing the rotary adapter to move axially away from
the shaft adapter until the engagement pin 158 contacts the stop
pin 148A, thereby preventing further clockwise rotation. Similarly,
when the rotation is in the counterclockwise direction, the rotary
adapter moves toward the shaft adapter until the stop pin 148B
prevents further rotation. Due to the circular flange 182 of the
shaft adapter being retrained in the annular slot, the shaft
adapter is not able to move axially in the channel during rotation
of the shaft. Therefore, the effective length of the endoscope
shaft does not change during rotation. This aspect of the invention
advantageously allows the axial position of the endoscope tip to be
maintained in the body during rotation. Furthermore, the components
in the endoscope shaft do not contract or stretch during
rotation.
[0038] Although the embodiment shown in FIG. 5 uses two stop pins
148A,B, it will be appreciated that a single stop pin 148B could be
used by limiting the depth of the threads in the collar 144 such
that the engagement pin 158 on the rotary adapter 156 cannot ride
in the threaded grooves and thereby limiting rotation of the
endoscope shaft 170.
[0039] FIG. 7 is a partial cutaway drawing illustrating an
alternative embodiment of a selectively rotatable shaft coupler 180
that attaches an endoscope shaft to a collar 190. The shaft coupler
180 maintains the effective length of the endoscope shaft during
rotation. In the embodiment shown in FIG. 7, a shaft adapter 182
has a set of grooves 184 cut along its longitudinal axis that
slidably engage a corresponding set of ribs 194 on a rotary adapter
192. An engagement pin 198 on the rotary adapter rides in the
threaded grooves of the collar 190 and a stop 199 at the end
thereof prevents further axial movement of the rotary adapter,
thereby limiting rotation. The longitudinal grooves 184 on the
shaft adapter 182 are best shown in FIG. 8A. FIG. 8B illustrates
the rotary adapter 192 with ribs 194 slidably engaged in the
grooves 184 on the shaft adapter 182. In the embodiment shown, the
endoscope shaft 196 is corrugated to provide a secure attachment to
the shaft adapter 182. A circular flange 185 allows the rotary
adapter 182 to rotate in the collar (see FIG. 7), but prevents
axial movement of the shaft adapter 182, thereby maintaining the
effective length of the endoscope shaft during rotation. The
rotatable shaft coupler 180 is preferably assembled by forming the
collar 190 in two halves that are fitted over the rotary adapter
192 and the shaft adapter 182.
[0040] In another aspect, the present invention provides a
selectively rotatable shaft coupler 200 having a shaft adapter with
a first end non-rotatably fixed to a housing or other object and a
second end adapted to rotatably receive an endoscope shaft. As
shown in FIG. 9, the coupler 200 comprises a shaft adapter 202 with
a first end 203 that is non-rotatably attached to a housing 206 and
a second end 205 sized to rotatably receive an end of a shaft 216.
The shaft adapter 202 has a threaded section 204 midway between the
first end 203 and the second end 205. Positioned between the
threaded section 204 and the second end 205 is a set of ratchets
208 capable of functioning as one-way stop elements as further
described below. Also included in the coupler 200 is a collar 210
non-rotatably secured over an end of a shaft 216. The collar 210
has a stop pin extending inwardly toward the shaft 217 and located
at a position chosen to stop rotation of the shaft 216. The shaft
216 has a threaded section 212 at or near its proximate end, the
threaded section capable of screwing onto the threaded section 204
on the shaft adapter 202. In operation, the collar 212 is secured
over the end of the shaft 216. The shaft 216 is then screwed onto
the shaft adapter 202 over the ratchets 208 in a clockwise
direction. Once the threaded section 212 of the shaft 216 is
screwed onto the threaded section 204 of the shaft adapter 202, the
shaft 216 can be rotated in a clockwise direction until the end of
the shaft 216 and/or collar 210 contacts the wall of the housing
206. Rotation of the shaft 216 in a counterclockwise direction is
permitted until the stop element 214 on the collar 210 contacts the
ratchets 208, thereby preventing further counterclockwise
rotation.
[0041] In another aspect, the present invention provides a shaft
coupling system for connecting a proximal end of an endoscope shaft
302 to a housing 310 or other structure without the use of adhesive
or epoxies. A representative embodiment of the shaft coupling
system 300 is shown in FIG. 10A. As shown, an endoscope shaft 302
is coupled to the housing 310 via a shaft retainer 304 that is
press-fit into the housing 310. As shown more clearly in FIG. 10B,
the shaft retainer 304 has a cylindrical hollow shape that is sized
to fit into the housing 310. The outward surface of the shaft
retainer 304 has a plurality of outward extending barbs 308 capable
of securing the shaft retainer 304 into the housing 310. The inward
surface of the shaft retainer body has a plurality of inward
rearwardly extending barbs 306 that are capable of securing the
endoscope shaft 302 into the shaft retainer. The shaft retainer 304
may additionally have a circular flange at one end to ease the
insertion of the endoscope shaft 302.
[0042] The shaft retainer 304 may be made out of metal and be
stamped to form the plurality of inward rearwardly and outwardly
extending barbs. The stamped shaft retainer 304 may then be
press-fit into the housing 310. In operation, the outwardly
extending barbs 308 on the shaft retainer 304 secure the retainer
ring in the housing without the need for adhesives or epoxies. Once
the shaft retainer is secured in the housing, the endoscope shaft
302 is fitted into the housing via the inward rearwardly extending
barbs 306 on the shaft retainer 304.
[0043] An alternative embodiment of a shaft coupling system 320 is
shown in FIG. 11A. In this embodiment, an endoscope shaft 322 is
secured in a shaft retainer 324 having one or more anti-rotation
bosses. The shaft retainer 324 is fitted into a housing 330 having
pockets or slots that are sized to receive the one or more
anti-rotation bosses. As shown more clearly in FIG. 11B., the shaft
retainer 324 has two anti-rotation bosses 326A, 326B that protrude
from the outward facing side of the shaft retainer body. The inward
facing side of the shaft retainer body comprises a plurality of
inward rearwardly extending barbs 328 capable of securing the
endoscope shaft 322. The shaft retainer with anti-rotation bosses
324 may be injection molded and fitted onto the proximal end of an
endoscope shaft, wherein the inwardly extending barbs 328 secure
the endoscope shaft without the need for adhesives or epoxies. The
shaft retainer secured to the endoscope shaft may then be assembled
with two halves of the housing, the one or more anti-rotation
bosses fitted into preformed pockets in the housing. The coupling
system 320 thereby allows for a secured connection between the
endoscope shaft and a housing without allowing rotation or pull-out
of the endoscope shaft and without the need for adhesives or
epoxies.
[0044] While the preferred embodiment of the invention has been
illustrated and described, it will be appreciated that various
changes can be made therein without departing from the scope of the
invention.
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