U.S. patent application number 15/729289 was filed with the patent office on 2019-04-11 for modular cable strain relief device for articulated arm robotic systems.
The applicant listed for this patent is Verily Life Sciences LLC. Invention is credited to Maximilian Kapczynski, Eden Rephaeli.
Application Number | 20190105787 15/729289 |
Document ID | / |
Family ID | 65992851 |
Filed Date | 2019-04-11 |
United States Patent
Application |
20190105787 |
Kind Code |
A1 |
Kapczynski; Maximilian ; et
al. |
April 11, 2019 |
MODULAR CABLE STRAIN RELIEF DEVICE FOR ARTICULATED ARM ROBOTIC
SYSTEMS
Abstract
A device for relief of strain on a cable includes a modular base
for mounting, a first arm, a second arm, and a spring assembly. The
first arm is pivotally coupled to the modular base. A first
proximal end of the first arm is connected to the modular base at a
first pivot point for pivoting of the first arm about a first
rotational axis. The second arm is coupled to the modular base. A
second proximal end of the second arm is connected to the modular
base. The spring assembly is coupled to the first arm to provide a
clamping force between the first arm and the second arm.
Inventors: |
Kapczynski; Maximilian;
(Palo Alto, CA) ; Rephaeli; Eden; (San Francisco,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Verily Life Sciences LLC |
Mountain View |
CA |
US |
|
|
Family ID: |
65992851 |
Appl. No.: |
15/729289 |
Filed: |
October 10, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 34/30 20160201;
F16L 3/18 20130101; A61B 2034/715 20160201; B25J 19/0025 20130101;
A61B 2034/305 20160201; H02G 11/00 20130101; F16G 11/00 20130101;
F16L 3/10 20130101; F16G 11/048 20130101; H02G 3/32 20130101 |
International
Class: |
B25J 19/00 20060101
B25J019/00; F16L 3/10 20060101 F16L003/10; F16L 3/18 20060101
F16L003/18; A61B 34/30 20060101 A61B034/30 |
Claims
1. A device for relief of strain on a cable, comprising: a modular
base for mounting the device; a first arm pivotally coupled to the
modular base, wherein a first proximal end of the first arm is
connected to the modular base at a first pivot point for pivoting
of the first arm about a first rotational axis; a second arm
coupled to the modular base, wherein a second proximal end of the
second arm is connected to the modular base; a spring assembly
coupled to the first arm to provide a clamping force between the
first arm and the second arm; a first roller coupled to the first
arm and configured to rotate unidirectionally about a third
rotational axis; and a second roller coupled to the second arm and
configured to rotate bidirectionally about a fourth rotational
axis.
2. The device of claim 1, wherein the second arm is pivotally
coupled to the modular base, and wherein the second proximal end of
the second arm is connected to the modular base at a second pivot
point for pivoting of the second arm about a second rotational
axis.
3. (canceled)
4. (canceled)
5. The device of claim 1, wherein the first roller is configured to
rotate unidrectionally about the third rotational axis via a first
locking clutch disposed between the first roller and the first
arm.
6. A device for relief of strain on a cable, comprising: a modular
base for mounting the device; a first arm pivotally coupled to the
modular base, wherein a first proximal end of the first arm is
connected to the modular base at a first pivot point for pivoting
of the first arm about a first rotational axis; a second arm
pivotally coupled to the modular base, wherein a second proximal
end of the second arm is connected to the modular base at a second
pivot point for pivoting of the second arm about a second
rotational axis; a first roller coupled to the first arm and
configured to rotate unidirectionally about a third rotational axis
via a first locking clutch disposed between the first arm and the
first roller; and a second roller coupled to the second arm and
configured to rotate unidrectionally about a fourth rotational axis
via a second locking clutch disposed between the second arm and the
second roller.
7. The device of claim 1, wherein the first roller is disposed
proximate to a first distal end of the first arm, wherein the first
distal end is opposite of the first proximal end, wherein the
second roller is disposed proximate to a second distal end of the
second arm, wherein the second distal end is opposite of the second
proximal end.
8. The device of claim 2, wherein the first rotational axis is
different than the second rotational axis, and wherein the first
rotational axis is parallel to the second rotational axis.
9. The device of claim 2, wherein the spring assembly includes: a
first torsion spring coupled to the modular base and the first
proximal end of the first arm, wherein the first torsion spring is
configured to provide a first force, included in the clamping
force, directed from the first arm toward the second arm; and a
second torsion spring coupled to the modular base and the second
proximal end of the second arm, wherein the second torsion spring
is configured to provide a second force, included in the clamping
force, directed from the second arm toward the first arm.
10. The device of claim 8, wherein the first proximal end of the
first arm is positioned between the first torsion spring and the
modular base, wherein the second proximal end of the second arm is
positioned between the second torsion spring and the modular
base.
11. The device of claim 2, wherein a shape of the first roller and
the second roller is an annular cylindroid having a radius that
decreases longitudinally towards a midpoint of the annular
cylindroid.
12. The device of claim 2, wherein the first rotational axis is
orthogonal to the third rotational axis, and wherein the second
rotational axis is orthogonal to the fourth rotational axis.
13. The device of claim 1, wherein the spring assembly includes a
tension spring coupled to the first arm and the second arm to
provide the clamping force.
14. The device of claim 1, wherein the modular base includes a
first base plate parallel to a second base plate, wherein the first
proximal end of the first arm and the second proximal end of the
second arm are disposed between the first base plate and the second
base plate.
15. The device of claim 1, wherein the modular base is configured
to removably mount to an object via a latch handle and a latch pin,
each coupled to the modular base, wherein the latch handle adjusts
a magnitude of a compressive force applied by the modular base to
the object.
16. A robotic surgical system, the system comprising: an
articulated robotic arm including at least one joint to provide
articulation of the robotic arm; an end effector coupled to a
distal end of the articulated robotic arm; a cable extending along
the articulated robotic arm, wherein the cable is coupled to the
end effector; and a strain relief device coupled to the cable and
the articulated robotic arm to provide relief of strain on the
cable, wherein the strain relief device includes: a modular base
configured to be removably mounted to the articulated robotic arm;
a first arm pivotally coupled to the modular base, wherein a first
proximal end of the first arm is connected to the modular base at a
first pivot point for pivoting of the first arm about a first
rotational axis; a second arm coupled to the modular base, wherein
a second proximal end of the second arm is connected to the modular
base; a spring assembly coupled to the first arm to provide a
clamping force on the cable positioned between the first arm and
the second arm, wherein the clamping force is a compressive force
applied to the cable by the first arm and the second arm.
17. The system of claim 16, wherein the second arm of the strain
relief device is pivotally coupled to the modular base, and wherein
the second proximal end of the second arm is connected to the
modular base at a second pivot point for pivoting of the second arm
about a second rotational axis.
18. The system of claim 16, wherein the strain relief device
further includes: a first roller coupled to the first arm proximate
to a first distal end of the first arm, wherein the first distal
end is opposite of the first proximal end, and wherein the first
roller is coupled to rotate about a third rotational axis; and a
second roller coupled to the second arm proximate to a second
distal end of the second arm, where the second distal end is
opposite of the second proximal end, and wherein the second roller
is coupled to rotate about a fourth rotational axis.
19. The system of claim 18, wherein the strain relief device
further includes: a first locking clutch disposed between the first
roller and the first arm, wherein the first roller is configured to
rotate unidirectionally about the third rotational axis due to the
first locking clutch.
20. The system of claim 19, wherein the strain relief device
further includes: a second locking clutch disposed between the
second roller and the second arm, wherein the second roller is
configured to rotate unidirectionally about the fourth rotational
axis due to the second locking clutch.
21. The system of claim 20, wherein the second roller of the strain
relief device is a free roller configured to rotate bidirectionally
about the fourth rotational axis.
22. A device for relief of strain on a cable, comprising: a modular
base for mounting the device; a first arm coupled to the modular
base, wherein a first proximal end of the first arm is connected to
the modular base; a second arm coupled to the modular base, wherein
a second proximal end of the second arm is connected to the modular
base, wherein at least one of the first arm or the second arm is
pivotally coupled to the modular base; a spring assembly coupled to
the first arm or the second arm to provide a clamping force between
the first arm and the second arm; a first roller coupled to the
first arm and configured to rotate unidirectionally about a third
rotational axis; and a second roller coupled to the second arm and
configured to rotate bidirectionally about a fourth rotational
axis.
Description
TECHNICAL FIELD
[0001] This disclosure relates generally to the field of strain
relief devices, and in particular but not exclusively, relates to
strain relief devices for robotic systems.
BACKGROUND INFORMATION
[0002] Industrial and medical robotic systems are becoming
increasingly large, complex, and dexterous. For example, robotic or
computer assisted surgery uses robotic systems to aid in surgical
procedures. Robotic surgery was developed as a way to overcome
limitations (e.g., spatial constraints associated with a surgeon's
hands, inherent shakiness of human movements, and inconsistency in
human work product, etc.) of pre-existing surgical procedures. In
recent years, the field has advanced greatly to limit the size of
incisions, and reduce patient recovery time.
[0003] In the case of open surgery, robotically controlled
instruments may replace traditional tools to perform surgical
motions. Feedback controlled motions may allow for smoother
surgical steps than those performed by humans. For example, using a
surgical robot for a step such as rib spreading, may result in less
damage to the patient's tissue than if the step were performed by a
surgeon's hand. Additionally, surgical robots can reduce the amount
of time in the operating room by requiring fewer steps to complete
a procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Non-limiting and non-exhaustive embodiments of the invention
are described with reference to the following figures, wherein like
reference numerals refer to like parts throughout the various views
unless otherwise specified. Not all instances of an element are
necessarily labeled so as not to clutter the drawings where
appropriate. The drawings are not necessarily to scale, emphasis
instead being placed upon illustrating the principles being
described.
[0005] FIG. 1 illustrates a system for robotic surgery, in
accordance with an embodiment of the disclosure.
[0006] FIG. 2A illustrates a perspective view of a strain relief
device, in accordance with an embodiment of the disclosure.
[0007] FIG. 2B illustrates an exploded view of a strain relief
device, in accordance with an embodiment of the disclosure.
[0008] FIG. 2C illustrates a cross-sectional view of a strain
relief device, in accordance with an embodiment of the
disclosure.
[0009] FIGS. 3A-3D illustrate a method of operation of a strain
relief device, in accordance with an embodiment of the
disclosure.
[0010] FIG. 4 illustrates a perspective view of a strain relief
device, in accordance with an embodiment of the disclosure.
DETAILED DESCRIPTION
[0011] Embodiments of a modular device for cable strain relief are
described herein. In the following description numerous specific
details are set forth to provide a thorough understanding of the
embodiments. One skilled in the relevant art will recognize,
however, that the techniques described herein can be practiced
without one or more of the specific details, or with other methods,
components, materials, etc. In other instances, well-known
structures, materials, or operations are not shown or described in
detail to avoid obscuring certain aspects.
[0012] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment of the present invention. Thus,
the appearances of the phrases "in one embodiment" or "in an
embodiment" in various places throughout this specification are not
necessarily all referring to the same embodiment. Furthermore, the
particular features, structures, or characteristics may be combined
in any suitable manner in one or more embodiments.
[0013] As the breadth of applications for industrial and medical
robotic systems grows, the diversity of robotic end effectors and
other devices for these systems follows suit. For example, a
modular, multi-use robotic system may support interchangeably
hot-swapping end effectors. It may be desirable to hot swap end
effectors of a surgical robotic system during steps in a surgical
procedure. However, the technical complexity of these end effectors
is also ever-increasing and may incorporate specialized supply
lines that are distributed to the end effector. These specialized
supply lines may include electrical supply lines, pneumatic or
hydraulic lines, optical fiber lines for data relay, communication,
or high-power illumination, and others.
[0014] The desired modularity, compatibility, interoperability,
interchangeability, and specialized supply lines of industrial and
medical robotic systems pose a significant design challenge. For
example, it is desirable for the robotic system to support a
variety of end effectors, but such interchangeability may result in
increased complexity and cost of the robotic system.
[0015] In some embodiments, a complex articulated robotic system
may incorporate a number of end effectors, which may introduce a
large quantity of supply cabling for supply lines coupled to the
end effectors. These supply lines may be delicate, stiff, heavy,
temperature sensitive, and/or shock sensitive. Operation of the
articulated robotic system may involve one or more large, heavy,
and powerful arms that may move in many different directions at a
high rate of speed or magnitude of force. This may pose an
operating hazard to the cabling for the end effectors. For example,
unwanted tangling, twisting, kinking, or shearing of the cabling of
the robotic system may inadvertently result in the loss of end
effector function and subsequent loss of system functionality.
[0016] In the same or other embodiments, a strain relief device may
offer an economical and reliable way of protecting end effector
cabling of a robotic system. The strain relief device may apply a
clamping force to secure the cable in the necessary directions to
prevent damage, but may also selectively allow a freedom of motion
in other directions in situations where the cable would be damaged
if held in place. For example, the strain relief device may allow
for the cable to move along a direction during articulation of a
robotic arm in a robotic system. The strain relief device may be
self-contained and not integral to the robotic system. In other
words, an operator may be capable of easily and safely
re-positioning the cable within the strain relief device during
operation, or reposition the strain relief device itself in order
to accommodate a changing operational environment for the robotic
system.
[0017] FIG. 1 illustrates system 101 for robotic surgery, in
accordance with an embodiment of the disclosure. System 101
includes processing apparatus 172 and surgical robot 182. Surgical
robot 182 may include joints 186 and 187, a plurality of end
effectors (including light source 191, surgical instrument 192, and
camera 193), cable 185, and strain relief devices 103 and 104.
Processing apparatus 172 may include a display, a processor,
memory, local storage, and the like to facilitate the operation of
surgical robot 182. As shown, the plurality of end effectors (191,
192, 193) of surgical robot 121 may be used to hold various
surgical tools for a surgical procedure (e.g., each arm of the
surgical robot holds a surgical tool at the distal ends of the arm)
and perform surgery, diagnose disease, take biopsies, or conduct
any other procedure a doctor could perform. The surgical tools may
include one or more of surgical instrument 192 (e.g., scalpels,
forceps, clamps, staplers, probes, etc.), camera 101 (e.g., image
sensor), light source 191(e.g., light-emitting diode, laser, fiber
optic, etc.) or the like. The arms of surgical robot 182 may be
articulated to allow for precise control of movement and position
of surgical robot 182. As illustrated, surgical robot 182 includes
joints 186 and 187 to provide the desired articulation of the arms
of surgical robot 182. While surgical robot 182 is illustrated as
having only three arms and six joints, one skilled in the art will
appreciate that surgical robot 182 is merely an illustration, and
that surgical robot 182 may take any number of shapes depending on
the type of surgery needed to be performed and other
requirements.
[0018] As illustrated, the plurality of end effectors (191, 192,
and 193) of surgical robot 182 is variously coupled to cable 185.
Cable 185 provides specialized supply lines such as electrical
supply lines, pneumatic or hydraulic lines, optical fiber lines for
data relay, communication, or high-power illumination, and others
to the plurality of end effectors (191, 192, and 193). Cable 185
may be delicate, stiff, heavy, temperature sensitive, and/or shock
sensitive, or otherwise desired to be protected to facilitate
operation of surgical system 100. Strain relief devices 103 and 104
are removably mounted to surgical robot 182 and coupled to cable
185 along various points of surgical system 100. Strain relief
devices 103 and 104 relieve strain on cable 185, for example, by
holding cable 185 in place with varying amounts of resistance to
mitigate unwanted tangling, twisting, kinking, or shearing of cable
185. In some embodiments, cable 185 may be held in place by strain
relief devices 103 and 104 during articulation of surgical robot
182 to prevent cable 185 from interfering with the movement of
surgical robot 182 or others. Alternatively or in addition, strain
relief devices 103 and 104 may facilitate the movement of cable 185
along a direction that would otherwise cause cable 185 to be
damaged. For example, strain relief devices 103 and 104 allow for
cable 185 to be moved along a single direction during articulation
of surgical robot 182. This may prevent damage to cable 185 if, for
example, there is not enough slack in cable 185 to allow surgical
robot 182 to articulate a desired amount.
[0019] In some embodiments, cable 185 is a bundle of individual
cables necessary for the plurality of end effectors (191, 192,
193). The bundle of individual cables have a thickness greater than
any individual cable in the bundle. Thus, in some embodiments,
cable 185 may have a single unified size or shape, while in other
embodiments, cable 185 may have various sizes and shapes dependent
on the configuration of surgical robot 182. Therefore, it is
appreciated that a size and shape of strain relief devices 103 and
104 may correspond to a particular size and shape of an individual
cable or bundle of cables.
[0020] Surgical robot 182 is coupled to processing apparatus 172,
which may be coupled to a network and/or external storage either by
wires or wirelessly. Furthermore, surgical robot 182 may be coupled
(wirelessly or by wires) to a user input/controller to receive
instructions from a surgeon or doctor. The controller, and user of
the controller, may be located very close to surgical robot 182 and
patient (e.g., in the same room) or may be located many miles
apart. Thus surgical robot 182 may be used to perform surgery where
a specialist is many miles away from the patient, and instructions
from the surgeon are sent over the internet or secure network.
Alternatively, the surgeon may be local and may simply prefer using
surgical robot 182 because it can better access a portion of the
body than the hand of the surgeon could.
[0021] FIGS. 2A-2C illustrate three views of strain relief device
200, in accordance with various embodiments of the disclosure.
Strain relief device 200 is one possible implementation of strain
relief devices 103 and 104 illustrated in FIG. 1. The illustrated
embodiment of strain relief device 200 includes modular base 235
(including first base plate 237 and second base plate 241), first
arm 205, second arm 220, first locking clutch 217, second locking
clutch 222, first roller 219, second roller 224, spring assembly
(including first torsion spring 225 and second torsion spring 226),
first stop pin 251, second stop pin 253, third stop pin 252, fourth
stop pin 254, first pivot pin 257, second pivot pin 258, mounting
feature 255, latch pin 267, and latch handle 270.
[0022] FIG. 2A illustrates a perspective view of strain relief
device 200, in accordance with an embodiment of the disclosure.
Strain relief device 200 is mounted to feature 295 of object 290.
Object 290 may be a wall, table, industrial robotic system, medical
robotic system, and the like. Feature 295 is a designed location
for mounting strain relief device 200. In some embodiments, feature
295 may be a rigid post. In other embodiments, feature 295 may be a
pivotable or flexible feature. For example, feature 295 may be a
free pivot, a ball-socket, or a flexible member to free up or
constrain degrees of freedom as required by a particular
application. In one embodiment, strain relief device 200 is mounted
to an articulated robotic arm of the medical robotic system and is
configured to apply a clamping force to cable 285 to relieve strain
on cable 285.
[0023] As illustrated, modular base 235 is for mounting strain
relief device 200 (e.g., to feature 295 of object 290). Strain
relief device 200 includes first arm 205 pivotally coupled to
modular base 235. In particular, a first proximal end of first arm
205 is connected to modular base 235 at a first pivot point (e.g.,
with first pivot pin 257) for pivoting of first arm 205 about a
first rotational axis 281. Similarly, second arm 220 is pivotally
coupled to modular base 235. A second proximal end of second arm
220 is connected to modular base 235 at a second pivot point (e.g.,
with second pivot pin 258) for pivoting of second arm 220 about a
second rotational axis 283. Pivoting of the arms (e.g., first arm
205 and second arm 220) allows for a position of the arms to change
to allow for cable 285 to be inserted and/or removed from between
first arm 205 and second arm 220. The spring assembly (e.g., first
torsion spring 225) is coupled to first arm 205 to provide a
clamping force between first arm 205 and second arm 220. The
clamping force may be able to be applied, at least in part, because
first arm 205 and/or second arm 220 is able to pivot about first
rotational axis 281 and second rotational axis 283, respectively,
rather than being fixed in position.
[0024] In some embodiments, first rotational axis 281 is parallel
to second rotational axis 283 such that the first arm 205 is
aligned with second arm 220 (e.g., the center of first arm 205 is
aligned with the center of second arm 220 along a line
perpendicular to first rotational axis 281 and second rotational
axis 283). In the same or other embodiments, one of first arm 205
or second arm 220 may be fixed in position to modular base 235
while the other arm is pivotally coupled. For example, first arm
205 may be pivotally coupled to modular base 235, while second arm
220 may be statically coupled to modular base 235 (e.g., a second
proximal end of the second arm is connected to the modular base at
a fixed position). In such an embodiment, modular strain device 200
may have a reduced complexity, but still allow for one of the first
arm 205 or second arm 220 to change in position so cable 285 may be
inserted and/or removed from between first arm 205 and second arm
220.
[0025] As illustrated, a first roller 219 is coupled to first arm
205 proximate to a first distal end of first arm 205. First roller
219 is positioned to rotate about third rotational axis 280, which
in the illustrated embodiment extends longitudinally through first
arm 205. Similarly, a second roller 224 is coupled to second arm
220 proximate to a second distal end of second arm 220. Second
roller 224 is positioned to rotate about fourth rotational axis 282
which in the illustrated embodiment extends longitudinally through
second arm 220. First roller 219 and second roller 224 may be free
rollers which allows for bidirectional rotation or may be locking
rollers which only allow for unidirectional rotation. In other
words, depending on the configuration of strain relief device 200,
first roller 219 and second roller 224 may each allow for only
clockwise rotation, only counter clockwise rotation, or both
clockwise and counterclockwise rotation.
[0026] In the illustrated embodiment, first locking clutch 217
(e.g., a one way sprag clutch) is disposed between first roller 219
and first arm 205 to configure first roller 219 to only allow for
unidirectional rotation along third rotational axis 280. Similarly,
second locking clutch 222 is disposed between second roller 224 and
second arm 220 to configure second roller 224 to only allow for
unidirectional rotation about fourth rotational axis 282. In other
embodiments, a ball bearing is disposed between first roller 219
and first arm 205 and/or second roller 224 and arm 220 to allow for
bidirectional rotation of first roller 219 and/or second roller
224. In some embodiments, third rotational axis 280 is orthogonal
to first rotational axis 281 and fourth rotational axis 282 is
orthogonal to second rotational axis 283, which may help facilitate
first arm 205 and first roller 219 aligning with second arm 220 and
second roller 224.
[0027] FIG. 2B illustrates an exploded view of strain relief device
200, in accordance with an embodiment of the disclosure. The
exploded view may allow for a clear visualization of the various
elements of strain relief device 200.
[0028] As illustrated, first roller 219 and second roller 224 share
a common shape. The shape of first roller 219 and second roller 224
is an annular cylindroid having a radius that decreases
longitudinally towards a midpoint of the annular cylindroid. For
example, the radius of first end 221 of first roller 219 may be the
same as the radius of the second end 223. The radius of first end
221 and second end 223 gradually decreases towards the midpoint 225
of first roller 219. Such a change in radius of first roller 219
creates a contoured external surface of first roller 219 that is an
inverse shape of a surface of cable 285. In other words, the
external surface of first roller 219 or second roller 224 is shaped
in a way that increases the contact area of first roller 205 and
second roller 220 with a cable (e.g., cable 285 illustrated in FIG.
2A). The increased contact area of first roller 219 and second
roller 224 to the cable may increase the frictional resistance of
the cable to move. Thus, the ease of adjusting the position of the
cable while clamped may be determined, in part, by the contact
area/frictional resistance.
[0029] In the illustrated example, first arm 205 includes first
distal end 207, a cylindrical stopper 209, and a first proximal end
211. First distal end 207 is opposite of first proximal end 211.
First distal end 207 is cylindrical having a radius that is less
than cylindrical stopper 209. Cylindrical stopper 209 may help
facilitate maintaining locking clutch 217 and first roller 219 at a
fixed position on first arm 205. First proximal end 213 includes
first stopper pin hole 213 and first pivot pin hole 215 to allow
for pivoting of first arm 205, in accordance with an embodiment of
the disclosure. Proximal end 215 includes a first arm plate and a
second arm plate separated by a distance to allow for torsion
spring 225 to be placed between the first arm plate and the second
arm plate.
[0030] As illustrated, modular base 235 includes first base plate
237 parallel to second base plate 241. First proximal end 211 of
first arm 205 and second proximal end of second arm 220 are
disposed between first base plate 237 and second base plate 241.
Each of the base plates (237 and 241) having corresponding holes
for first pivot pin 257, second pivot pin 258, second stop pin 253,
and fourth stop pin 254 to facilitate the pivoting of the
corresponding arm (205 and 220) and the clamping force. For
example, second base plate 241 has first pivot pin hole 243 for
first pivot pin 256 and second stop pin hole 245 for second stop
pin 253. In some embodiments, first base plate 237 and second base
plate 241 each have a saddle shape that has an indentation or
gradually decreasing height towards the midpoint. This saddle shape
may allow for base 235 to fully enclose some components of strain
relief device 200 (e.g., the spring assembly) without touching the
cable (e.g. cable 285 illustrated in FIG. 2A).
[0031] Referring back to FIG. 2B, modular base 235 is configured to
removably mount to an object via latch handle 270, latch pin 267,
and mounting feature 255. Latch handle 270 adjusts a magnitude of a
force applied to an object such that a compressive and/or
frictional force holds strain relief device 200 to the object. For
example, latch handle 270 may control the magnitude of the force
applied by mounting feature 255 of modular base 235 to the object
(e.g., feature 295 of object 290 illustrated in FIG. 2A). Thus
latch handle 270 and latch pin 267 of modular base 235 acts as a
quick release mechanism to quickly mount and/or unmount strain
relief device 200 from object 290.
[0032] FIG. 2C illustrates a cross-sectional view of strain relief
device 200, in accordance with an embodiment of the disclosure. The
cross-sectional view allows for a clear view of a portion of the
spring assembly of strain relief device 200.
[0033] As illustrated, the spring assembly of strain relief device
200 includes first torsion spring 225 coupled to modular base 235
and the first proximal end of first arm 205. First torsion spring
225 is coiled around first pivot pin 257 and has a first end
coupled to first stop pin 251 and a second end coupled to second
stop pin 253. First stop pin is coupled to first arm 205 and second
stop pin is coupled to modular base 235 meaning first torsion pin
225 applies a first force (e.g., a first torque included in the
clamping force) between first arm 205 and modular base 235. As
illustrated, the first force is directed from first arm 205 to
second arm 220. Second arm 220 may be similarly configured as first
arm 205. For example, second torsion spring 226 is coupled to
modular base 235 and the second proximal end of second arm 220.
Second torsion spring 226 is coiled around second pivot pin 258 and
has ends coupled to third stop pin 252 and fourth stop pin 254.
Thus, second torsion spring 226 provides a second force (e.g., a
second torque included in the clamping force) between second arm
220 and modular base 235. The second force is directed from second
arm 220 toward first arm 205 such that the combined first force and
second force generates a compressive force on the cable (e.g.,
cable 285) inserted between first arm 205 and second arm 220.
[0034] As illustrated, first torsion spring 225 and second torsion
spring 226 are fully contained within modular base 235, which may
protect the spring assembly from damage. This may be achieved, in
part, because the first proximal end of first arm 205 is positioned
between first torsion spring 225 and modular base 235. Similarly,
the second proximal end of second arm 220 is positioned between
second torsion spring 226 and modular base 235. Due to this
arrangement, the spring assembly is fully contained within modular
base 235 and does not come in direct contact with the cable (e.g.
cable 285).
[0035] FIGS. 3A-3D illustrate a method of operation of strain
relief device 300, in accordance with an embodiment of the
disclosure. Strain relief device 300 provides relief of strain on a
cable and may be the same or a similar implementation of strain
relief device 200 illustrated in FIGS. 2A-2C. Referring back to
FIGS. 3A-3D, strain relief device 300 includes first arm 305,
second arm 320, first roller 317, second roller 324, first locking
clutch 317, ball bearing 322, first torsion spring 325, second
torsion spring 326, modular base 335, latch handle 370, and
mounting feature 355.
[0036] FIG. 3A illustrates opening latch handle 370 such that
mounting feature 355 increases in radius to allow for placement of
strain relief device 300 on feature 395 of object 390. Mounting
feature 355 is subsequently aligned with and then placed on feature
395 of object 390. Latch handle 370 is then closed to hold strain
relief device 300 in placed and attached to object 390, as
illustrated in FIG. 3B. Once closed, latch handle 370 causes the
radius of mounting feature 355 to decrease which in turn generates
a compressive force on feature 395 that mounts strain relief device
300 to object 390.
[0037] FIG. 3C illustrates placing cable 385 between first arm 305
and second arm 320. This is accomplished by separating first arm
305 and second arm 320 with an external force 384 (e.g., manual
manipulation of first arm 305 and second arm 320 via an operator of
strain relief device 300) that causes first arm 305 and second arm
320 to pivot about the respective midpoints of first torsion spring
325 and second torsion spring 326.
[0038] As illustrated in FIG. 3D, once external force 384 is
released, first roller 319 of first arm 305 second roller 324 of
second arm 320 clamp onto cable 385 and hold cable 385 in place
with compressive force 388. While clamped, cable 385 is able to
move along a single direction (e.g. out of the plane of the page)
due to the allowable rotational directions of first roller 319 and
second roller 324. First roller 319 is only able to rotate
unidirectionally (e.g., counter clockwise) about rotational axis
380, due in part, because first locking clutch 317 is disposed
between first arm 305 and first roller 319, which restricts first
roller 319 to a single rotational direction. Second roller 324 is
able to rotate bidirectionally (e.g., clockwise and counter
clockwise) about rotational axis 382, due in part, because ball
bearing 319 is disposed between second roller 324 and second arm
320.
[0039] FIG. 4 illustrates a perspective view of strain relief
device 400, in accordance with an embodiment of the disclosure.
Strain relief device 400 is one possible implementation of strain
relief devices 103 and 104 illustrated in FIG. 1. The illustrated
embodiment of strain relief device 400 is similar to, but
comparably less complex than strain relief device 200 illustrated
in FIGS. 2A-2C.
[0040] As illustrated, strain relief device 400 includes first arm
405, second arm 420, tension spring 425, and modular base 435.
Strain relief device 400 is configured to be removably mounted to
an object via a mounting feature (e.g., an articulated arm of a
robotic system). In the illustrated case, the mounting feature of
strain relief device 400 is a dovetail, but may have any other
structure that facilitates mounting of strain relief device 400 to
the object. First arm 405 and second arm 420 are pivotally coupled
to modular base 420 and thus are able to pivot about their
respective rotational axes. Tension spring 425 is coupled to first
arm 405 and second arm 420 and generates a clamping force that
holds cable 485 in place when positioned between first arm 405 and
second arm 420.
[0041] In reference to embodiments of the disclosure, a roller, an
arm, a locking clutch, and/or a ball bearing are described for
restricting the rotation of the roller and movement of the clamped
cable. However, it is appreciated that other configurations may
also allow for the restriction of the rotation of the roller and/or
movement of the clamped cable. For example, instead of a roller
coupled to an arm turning within a statically located locking
clutch, the roller and locking clutch could be a single unit
turning on a statically located arm. Additionally, or
alternatively, a paired linear sequence of smaller rollers that
rotate unidirectionally could be utilized in place of the two
rollers.
[0042] The above description of illustrated embodiments of the
invention, including what is described in the Abstract, is not
intended to be exhaustive or to limit the invention to the precise
forms disclosed. While specific embodiments of, and examples for,
the invention are described herein for illustrative purposes,
various modifications are possible within the scope of the
invention, as those skilled in the relevant art will recognize.
[0043] These modifications can be made to the invention in light of
the above detailed description. The terms used in the following
claims should not be construed to limit the invention to the
specific embodiments disclosed in the specification. Rather, the
scope of the invention is to be determined entirely by the
following claims, which are to be construed in accordance with
established doctrines of claim interpretation.
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