U.S. patent application number 14/925983 was filed with the patent office on 2017-05-04 for multi-axis robot with remote drives facilitating hazardous energy isolation for use by home consumers.
This patent application is currently assigned to GOURMEON, INC.. The applicant listed for this patent is XIAOYI HUANG, SHAMBHU NATH ROY. Invention is credited to XIAOYI HUANG, SHAMBHU NATH ROY.
Application Number | 20170120453 14/925983 |
Document ID | / |
Family ID | 58637176 |
Filed Date | 2017-05-04 |
United States Patent
Application |
20170120453 |
Kind Code |
A1 |
ROY; SHAMBHU NATH ; et
al. |
May 4, 2017 |
MULTI-AXIS ROBOT WITH REMOTE DRIVES FACILITATING HAZARDOUS ENERGY
ISOLATION FOR USE BY HOME CONSUMERS
Abstract
A modular robot mechanism utilizing fixed drives, power sources,
power delivery cables and electrical components for 4 or more axes
in a protective enclosure while making it possible to provide
spatial positioning and tilting degrees of freedom to an end
effector suitable for using in a consumer product. Furthermore a
robotic head mechanism is disclosed that creates additional degrees
of freedom or states by combination of existing axes with spring
loaded lock mechanisms eliminating need for conventional
electrically actuated solenoid or pneumatic grippers making it
possible for use as a home appliance. A method to control the robot
mechanism and additional axis utilizing a matrix to decouple the
input position to the remote actuator and Cartesian motion produced
at the end effector.
Inventors: |
ROY; SHAMBHU NATH; (Fremont,
CA) ; HUANG; XIAOYI; (Union City, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ROY; SHAMBHU NATH
HUANG; XIAOYI |
Fremont
Union City |
CA
CA |
US
US |
|
|
Assignee: |
GOURMEON, INC.
FREMONT
CA
|
Family ID: |
58637176 |
Appl. No.: |
14/925983 |
Filed: |
October 29, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B25J 9/023 20130101;
B23Q 1/626 20130101; B25J 5/04 20130101; B25J 15/009 20130101; B25J
9/104 20130101 |
International
Class: |
B25J 15/00 20060101
B25J015/00; B25J 9/12 20060101 B25J009/12 |
Claims
1. A robot mechanism comprising: at least one end effector link
with plurality of degrees of freedom able to move a target object
along a first translation axis, a second translation axis, a third
translation axis and rotate said target object about a tilt axis;
at least one of said plurality of degrees of freedom chosen from
the said second translation axis, said third translation axis and
said tilt axis is controlled by a motor attached to a frame; said
motor driving a pulley belt assembly stack comprising of a drive
belt looping around a drive pulley, an idler near pulley, an
intermediate near pulley, an end pulley, an intermediate far pulley
and an idler far pulley; wherein said drive pulley, said idler near
pulley, said idler far pulley are rotatable mounted to a said
frame; and said intermediate near pulley, said intermediate far
pulley and said end pulley are rotatable mounted on a base member
that is translating along said first translation axis; wherein for
any position of said base member while translating along said first
axis, said drive belt closed loop around length stays same due to
the change in the distance between said idler near pulley and
intermediate near pulley being compensated by a corresponding
opposite change in the distance between the said intermediate far
pulley and said idler far pulley. wherein at least one of the
plurality of degrees of freedom chosen from said third translation
axis and said tilt axis is controlled by said drive belt further
driving a ball screw nut driver pulley placed between a secondary
near idler pulley and a secondary far idler pulley wherein said
ball screw nut driver pulley, said secondary near idler pulley and
said secondary far idler pulley are rotatable mounted on a robot
head assembly base; wherein said robot head assembly base moves
together with said base member along said first translating axis
and moves along said second translation axis independently with
respect to said base member; wherein the said drive belt loop
around length stays same for any position of said robot head
assembly base position while translating along said first
translating axis and said second translating axis due to change in
the distance between said secondary idler near pulley and said
intermediate near pulley being compensated by a corresponding
opposite change in the distance between the said intermediate far
pulley and said secondary idler far pulley.
2. A mechanism as in claim 1, further comprising: at least one ball
screw nut rotatable mounted onto said robot head assembly base
driven by said ball screw nut driver pulley, said ball screw nut
rotating around a ball screw shaft attached to a translating link
for respective said third translating axis and said tilt axis. a
hinge joint connecting said end effector to said translating link
of said third translating axis; and a sliding joint connecting said
end effector to said translating link of said tilt axis; wherein
said motors of respective said third translating axis and said tilt
axis control position of said end effector along said third
translating axis and tilt about said tilt axis.
3. A mechanism according to claim 1, further comprising: at least
one ball screw nut rotatable mounted onto said robot head assembly
base driven by said ball screw nut driver pulley of said third
translating axis, said ball screw nut rotating around a ball screw
shaft attached to a translating link of said third translating
axis; a worm gear attached to said translating link using a hinge
joint connecting to said end effector, and; at least one worm screw
attached to said rotating nut of said tilt axis rotatable mounted
to robot head assembly base driven by said ball screw nut driver
pulley of said tilt axis, said worm screw driving said worm gear;
wherein independent motion of said motors of respective said third
translating axis and said tilt axis produce a controlled position
of said end effector along said third translating axis and a tilt
about said tilt axis.
4. A mechanism as in claim 2, further comprising: at least one
first axis linear guide rail mechanism supporting said base member;
and at least one second axis linear guide rail mechanism supporting
said robot head assembly; wherein said first axis linear guide rail
mechanism has a first axis linear guide attached to said base
member and first axis linear rail attached to said frame
facilitating said base member translating along said first axis;
wherein said second axis linear guide rail mechanism has a second
axis linear guide attached to said robot head assembly base and
second linear rail attached to said base member facilitating said
robot head assembly base translating along said second axis.
5. A mechanism as in claim 2, further comprising: at least one
first axis additional linear guide rail mechanism supporting said
base member; and at least one second axis additional linear guide
rail mechanism supporting said robot head assembly; wherein said
first axis additional support linear guide rail mechanism is
parallel to said first axis linear guide rail mechanism; wherein
said second axis additional support linear guide mechanism is
parallel to said second axis linear guide mechanism.
6. A mechanism according to claim 4, further comprising at least
one additional orthogonal linear guide mechanism to support said
second axis linear guide to said robot head base assembly to allow
for thermal expansions.
7. A mechanism according to claim 2, further comprising at least
one linear guide shaft and bearing assembly connecting said robot
assembly base member to said translating link in parallel to said
ball screw shaft for additional strength of said end effector.
8. A robot mechanism comprising: at least one end effector link
with plurality of degrees of freedom able to move a target object
along a first translation axis, a second translation axis, a third
translation axis and rotate said target object about a tilt axis;
at least one of said plurality of degrees of freedom chosen from
the said second translation axis, said third translation axis and
said tilt axis is controlled by a motor attached to a frame; said
motor driving a pulley belt assembly stack comprising of a drive
belt looping around a drive pulley, an idler near pulley, an
intermediate near pulley, an end pulley, an intermediate far pulley
and an idler far pulley; wherein said drive pulley, said idler near
pulley, said idler far pulley are rotatable mounted to a said
frame; and said intermediate near pulley, said intermediate far
pulley and said end pulley are rotatable mounted on a base member
that is translating along said first translation axis; wherein for
any position of said base member while translating along said first
axis, said drive belt closed loop around length stays same due to
the change in the distance between said idler near pulley and
intermediate near pulley being compensated by a corresponding
opposite change in the distance between the said intermediate far
pulley and said idler far pulley. wherein at least one of the
plurality of degrees of freedom chosen from said third translation
axis and said tilt axis is controlled by said drive belt further
driving a ball screw nut driver pulley placed between a secondary
near idler pulley and a secondary far idler pulley; wherein said
ball screw nut driver pulley, said secondary near idler pulley and
said secondary far idler pulley are rotatable mounted on a robot
head assembly base; wherein said robot head assembly base moves
together with said base member along said first translating axis
and moves along said second translation axis independently with
respect to said base member; wherein the said drive belt loop
around length stays same for any position of said robot head
assembly base position while translating along said first
translating axis and said second translating axis due to change in
the distance between said secondary idler near pulley and said
intermediate near pulley being compensated by a corresponding
opposite change in the distance between the said intermediate far
pulley and said secondary idler far pulley; at least one pick pin
attached to said end effector link; and at least one lock plate
connected to said end effector link by lock plate guide with
position restoring element pushing said lock plate against said end
effector link while allowing lock plate to translate in an
orthogonal direction to said pick pin axis when an external force
is applied to said lock plate; at least one lock pin attached to
said lock plate oriented along said lock plate guide; at least one
pick hole and at least one lock hole on a universal bar lift
attached to said target object.
9. A mechanism as in claim 8, further comprising; at least one tilt
multiplication gear attached to said end effector; at least one
tilt multiplication pinion rotatable mounted to said translating
link; wherein said tilt multiplication pinion is driven by tilt
multiplication gear to cause an enhanced rotation of any said end
effector tilt relative to said translating link.
10. A mechanism as in claim 8, further comprising: at least one
ball screw nut rotatable mounted onto said robot head assembly base
driven by said ball screw nut driver pulley, said ball screw nut
rotating around a ball screw shaft attached to a translating link
for respective said third translating axis and said tilt axis. a
hinge joint connecting said end effector to said translating link
of said third translating axis; and a sliding joint connecting said
end effector to said translating link of said tilt axis; wherein
said motors of respective said third translating axis and said tilt
axis control position of said end effector along said third
translating axis and tilt about said tilt axis.
11. A mechanism as in claim 8, further comprising: at least one
first axis linear guide rail mechanism supporting said base member;
and at least one second axis linear guide rail mechanism supporting
said robot head assembly; wherein said first axis linear guide rail
mechanism has a first axis linear guide attached to said base
member and first axis linear rail attached to said frame
facilitating said base member translating along said first axis;
wherein said second axis linear guide rail mechanism has a second
axis linear guide attached to said robot head assembly base and
second linear rail attached to said base member facilitating said
robot head assembly base translating along said second axis.
12. A mechanism as in claim 8, further comprising: at least one
first axis additional linear guide rail mechanism supporting said
base member; and at least one second axis additional linear guide
rail mechanism supporting said robot head assembly; wherein said
first axis additional support linear guide rail mechanism is
parallel to said first axis linear guide rail mechanism; wherein
said second axis additional support linear guide mechanism is
parallel to said second axis linear guide mechanism.
13. A mechanism according to claim 11, further comprising at least
one additional orthogonal linear guide mechanism to support said
second axis linear guide to said robot head base assembly to allow
for thermal expansions.
14. A mechanism according to claim 8, further comprising at least
one linear guide shaft and bearing assembly connecting said robot
assembly base member to said translating link in parallel to said
ball screw shaft for additional strength of said end effector.
15. A mechanism according to claim 8, comprising further a
protective enclosure housing said motor, controller and cables
remotely protected from harsh work environment.
16. A mechanism according to claim 15, further compatible to wash
down requirements by lack of use of electrical components outside
said protective enclosure.
17. A robot mechanism comprising: at least one end effector link
with plurality of degrees of freedom able to move a target object
along a first translation axis, a second translation axis, a third
translation axis and rotate said target object about a tilt axis;
at least one of said plurality of degrees of freedom chosen from
the said second translation axis, said third translation axis and
said tilt axis is controlled by a motor attached to a frame; said
motor driving a pulley belt assembly stack comprising of a drive
belt looping around a drive pulley, an idler near pulley, an
intermediate near pulley, an end pulley, an intermediate far pulley
and an idler far pulley; wherein said drive pulley, said idler near
pulley, said idler far pulley are rotatable mounted to a said
frame; and said intermediate near pulley, said intermediate far
pulley and said end pulley are rotatable mounted on a base member
that is translating along said first translation axis; wherein for
any position of said base member while translating along said first
axis, said drive belt closed loop around length stays same due to
the change in the distance between said idler near pulley and
intermediate near pulley being compensated by a corresponding
opposite change in the distance between the said intermediate far
pulley and said idler far pulley. wherein at least one of the
plurality of degrees of freedom chosen from said third translation
axis and said tilt axis is controlled by said drive belt further
driving a ball screw nut driver pulley placed between a secondary
near idler pulley and a secondary far idler pulley; wherein said
ball screw nut driver pulley, said secondary near idler pulley and
said secondary far idler pulley are rotatable mounted on a robot
head assembly base; wherein said robot head assembly base moves
together with said base member along said first translating axis
and moves along said second translation axis independently with
respect to said base member; wherein the said drive belt loop
around length stays same regardless of the position of said robot
head assembly base position while translating along said first
translating axis and said second translating axis due to change in
the distance between said secondary idler near pulley and said
intermediate near pulley being compensated by a corresponding
opposite change in the distance between the said intermediate far
pulley and said secondary idler far pulley; at least one pick pin
attached to said end effector link; and at least one lock plate
connected to said end effector link by lock plate guide with
position restoring element pushing said lock plate against said end
effector link while allowing lock plate to translate in an
orthogonal direction to said pick pin axis when an external force
is applied to said lock plate; at least one lock pin attached to
said lock plate oriented along said lock plate guide; at least one
pick hole and at least one lock hole on a universal bar lift
attached to said target object; at least one roller attached to
said lock plate allowing lock plate to push against a surface with
said roller while end effector is moving along said surface,
enabling movement of said lock plate away from said end effector
plate acting against the restoring element.
18. A mechanism according to claim 17 able to pick up said target
object and lock to said end effector; by moving said end effector
to a position next to said target object with said pick pin aligned
to said pick hole; by moving said end effector to a position for
said lock plate pushed away from said end effector to clear lock
pin out of way of aligned said pick pin and said pick pin hole; by
moving said end effector to a position to engage said pick pin into
respective said pick hole; by moving said end effector to align
said pick pin to a said pick hole; by moving said end effector to a
position to release lock plate and engage lock pin in lock
hole.
19. A mechanism according to claim 17 able to unlock and release
said target object from said end effector; by moving said end
effector to a position to push lock plate and disengage lock pin
from said lock hole; by moving said end effector to a position to
disengage said pick pin from said pick hole; by moving said end
effector to a position away from said target object.
20. A mechanism according to claim 17 wherein shaking sequences on
said end effector link are used generating a shaking sequence by
putting input commands to a said motor for reciprocating rotation.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM
LISTING COMPACT DISC APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The present invention generally relates to a robotic
mechanism for use in an apparatus for preparing dishes using recipe
steps and cooking conditions coded as a computer program recipe
executed by a kitchen top robotic cooking machine supplied with the
required ingredients with minimal user intervention while adjusting
recipe to tastes of the user.
[0005] A need exists for a robotic mechanism for use in automated
home cooking machines as disclosed in U.S. Pat. No. 9,131,807.
Gantry robots with three or more axes disclosed in prior art such
as U.S. Pat. No. 8,973,768 are serial mechanism and each axis
carries the next one. The first gantry axis such as x-axis is
driven by an actuator in combination with a linear motion device
such as ball screw driven by a motor or integrated as in a linear
motor, the actuator and motion elements for the second axis such as
y-axis are mounted onto the first axis or x-axis and all elements
of the y-axis move along x-axis, further more a third axis such as
a z-axis is made possible by similar actuator and linear motion
devices by attaching them to the y-axis firmly. So for any x-motion
the actuators and mechanism for y and z axis move along x-axis and
for any y-axis motion all elements of z-axis move along the
y-direction. So only the motor for first axis is stationary and the
rest of the actuators or motors are in constant motion. This
requires all the power cables and encoder feedbacks cables are
carried as well and flexible to allow changing shapes due to
changing positions between connected cable ends. Constant motion
can cause cables and motors to fail eventually and increasing the
cost with reduced reliability.
[0006] Further the user can be exposed to the hazardous voltages
being carried to the second and third motors by fatigue failure of
cable insulations due to stress fatigue or attack from corrosive
elements in workspace. Cable design and management is a very
critical aspect of such robotic mechanisms. Having to carry
secondary axes also creates additional force and strength
requirement from the primary axes requiring overdesign for primary
axes.
[0007] A need exists for a robot that is able to meet the needs of
a cooking machine that is used in a harsh environment as in the
case of household cooking where the robot mechanism is exposed to
various unsuitable conditions such as heat, moisture, grease,
fumes, acids and bases. Further the robot needs to be reliable for
use for long periods of times without requiring any servicing in a
home user environment as compared to an industrial environment
where regular daily, weekly, monthly and annual preventive
maintenance and inspections are common. The robot also needs to be
safe for average users not familiar with industrial machinery. The
robot needs to be able to carry weights ranging from light to
relatively heavy for its size. Electrical cables and connections
should not be exposed to cooking environment such as high
temperatures, moisture, fumes, grease and other particulate
material as this can cause their gradual degradation as well as
electrical shock and fire hazards caused by compromised insulation.
Furthermore an industrial robot with cables and motors moving
around are not a welcome sight for a consumer device.
[0008] Further a need exists for a robot that has positioning
precision suitable for a consumer application for home cooking by
transporting ingredients and intermediates efficiently but cost
effective at the same time. The positioning accuracy and overall
functionally should not be impacted by the operating conditions
such as temperatures and moisture. The robot mechanism must be
compact to be able to fit in a conventional kitchen and of
comparable size to a home appliance. The robot also needs to
provide continuous operation without need for periodic servicing as
in case of industrial robots. The robot should have safety features
to coexist with members of a household including children. The
robot mechanism should allow it to be design compatible with
government food preparation and health standards and keep
industrial machinery components such as lubricants, hazardous
design materials away from the operation area.
[0009] A need therefore exists to provide a robot that can be used
for a consumer food preparation device which can survive the harsh
conditions over long periods of time. The electrical systems and
drives can be located such that they are remote from the food
preparation areas and are not accessible to the user. There are no
moving cables or electrical power delivery components including
electrical connections exposed to the cooking environment. The
electrical systems and drives are safety isolated from the average
customer but can be accessed and serviced by qualified technicians.
The robot mechanism providing a large number or controlled degrees
of freedom as needed for three dimensional positioning, tilting and
gripping utilizing fewer motors and controlled axis to be cost
effective for a consumer application.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention provides a robot mechanism utilizing
fixed drives, power sources, power delivery cables and electrical
components for four or more axes in a protective enclosure while
making it possible to provide spatial positioning and tilting
degrees of freedom to an end effector such as an ingredient
container being moved to a cooking pot.
[0011] An object of the invention is to provide a three or more
axes robotic mechanism that has source of motion actuators such as
electric motors remotely located with respect to the robot
workspace and stationary. All such fixed motors are powered by
cables and other motion elements that do not move with the end
effector or impacted by the work environment. Another object of the
invention is to have all the actuator motors and supporting
elements located safely in a protective enclosure allowing placing
such a device for home use by average consumers not trained to be
around industrial robots.
[0012] According to an embodiment of the invention the actuator
motors are connected to the corresponding axes by means of a pulley
and belt arrangements such that the belt pulley mechanisms for each
axes are stacked spatially. Furthermore a robotic head mechanism is
disclosed that creates additional degrees of freedom or states by
combination of existing axes with spring loaded lock mechanisms
eliminating need for conventional electrically actuated solenoid or
pneumatic grippers. Further it allows actuator resource sharing
such as electronic or PLC robot controllers the cost of which is
proportional to the number of degrees of freedom.
[0013] Yet another object of the invention is to use restoring
forces such as spring in substantially orthogonal direction
clasping on a universal lift component that or features of which
are part of any target object to be picked and tilted. Once the
target object is picked it is secured well enough to even allow
contents to be disposed by tilting to an upside down position of
the target object such as a raw ingredient basket.
[0014] A further object of the invention is to amplify the tilt of
the end effector robot head by means of gears or other mechanical
rotation multiplication devices as known in the art.
[0015] A further object is to be able to wash down parts of the
robot mechanism exposed to the workspace area that can cause it to
be contaminated requiring cleaning as per food preparation
equipment codes as well as need reduced periodic maintanence.
[0016] Additional features and advantages of the present invention
are described in, and will be apparent from, the detailed
description of the preferred embodiments and from the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0017] The following is a description, by way of example only, of
different embodiments of the mechanism, its variations, derivations
and reductions.
[0018] FIG. 1 shows a 4-axis robot moving an ingredient basket
along X, Y and Z axes while tilting along T-axis aligned with
Y-axis driven by fixed motors and pulley stacks.
[0019] FIG. 2a shows a detailed 3D view of the pulley stacks for X,
Y, Z and T axes.
[0020] FIG. 2b shows a detailed top view of the pulley stacks for
X, Y, Z and T axes.
[0021] FIG. 3a shows a detailed view of robot head assembly along
with Z and Tilt mechanism.
[0022] FIG. 3a shows a detailed view of robot head assembly along
with Z and Tilt mechanism in a different position and tilt
angle.
[0023] FIG. 4 shows an alternate Z and Tilt mechanism using a worm
gear mechanism.
[0024] FIG. 5 shows a universal lift bar attached to an ingredient
basket.
[0025] FIG. 6a shows robot head in a position ready to pick an
ingredient basket
[0026] FIG. 6b shows robot head in a position ready to engage the
horizontal lock pins to the corresponding universal lift bar lock
holes to attached to the ingredient basket
[0027] FIG. 6c shows robot head in a position with horizontal lock
pins already engaged and ready to lock with the vertical lock pins
aligned to corresponding universal bar lock holes attached to the
ingredient basket.
[0028] FIG. 6d shows robot head in a position with the ingredient
basket picked up and universal lift bar securely locked to the
robot head.
[0029] FIG. 7a shows a tilt rotation multiplication means utilizing
a gears
[0030] FIG. 7b shows an alternate view of the components of tilt
with enhanced rotation.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Now referring to the drawings, wherein like numerals
designate like components, FIG. 1 shows a four axis gantry robot
mechanism comprising a robot head assembly R moving a target object
such as raw ingredients basket or container 5 along translating
axes X, Y, Z and tilting about tilt axis T. A target object or
container 5 has 4 degrees of freedom controlled by stationary
remote motors 11, 12, 13 and 14. Motors 11, 12, 13 and 14 are
mounted to a fixed frame F. The motors mounting can be
substantially rigid or based on the application environment has
spring and dampers to isolate vibration as known in the art. The
fixed frame F also acts as a protective enclosure, not fully shown
for clarity, the motors and other components are contained within
to limit access to only trained personnel with safety interlocks
that can trip or turn off power as needed. The motors also have
integrated encoder and controller interphase 26 that are connected
to motor drivers and controllers.
[0032] The robot head assembly R is mounted using a linear guide
rail mechanism to y-axis guide rail 10a by a x-axis linear motion
guide block 7a secured to robot head assembly base 2 such that the
robot head assembly R can move along x-axis guide rail 10a. An
additional linear motion x-axis guide block 7b along with an
additional x-axis guide rail 10b parallel to x-axis guide rail 10a
is used for added strength to allow use of smaller size linear
motion components with larger payloads. A third x-axis rail guide
rail 10c is fixed to x-axis guide rail 10a and x-axis guide rail
10b using a x-axis base member 1c such that the x-axis linear
motion guide rails 10a, 10b, 10c are parallel and do not move
relative to each other or the x-axis base member 1c. The x-axis
guide rail 10a is secured to y-axis linear motion block 6a which
can move onto the y-axis linear motion guide rail 9a fixed to the
frame F. The y-axis linear motion guide block 6a is secured to
x-axis base member 1a such that all x-axis motion parts 1a, 1b, 1c,
10a, 10b, 10c move together along y-axis guide rail 9a while
carrying the robot head assembly R along x-axis as well.
[0033] An additional y-axis guide rail 9b, also fixed to frame F is
used to provide additional support to the x-axis base members 1a,
1b, 1c and linear motion guide members by mounting them to the
additional y-axis guide rail 9b using an additional y-axis linear
motion block 6b through x-axis secondary base member 8 and x-axis
secondary linear motion guide 7c.The x-axis linear motion members
could be directly mounted by securing x-axis linear motion guide
rail 10a, 10b or 10c directly to x-axis secondary base member 8
eliminating linear motion guide 7c as well, but that would cause
stress and failure due to thermal environments causing expansion of
x-axis guide rails with y-axis guide rails fixed to frame F. Having
a secondary x-axis linear motion guide block 7c in series allows
this new mechanisms to eliminate any operational failure conditions
due to thermal expansion or contractions.
[0034] The robot head assembly base 2 has two controllable degrees
of freedom one each along horizontal axes X and Y. The robot head
assembly comprises of a first translating link 3a which moves along
the axes X, Y same as robot head assembly base 2 but possesses a
third controlled degree of freedom to move along a vertical z-axis
as will be explained further referring to FIGS. 3a and 3b. The
robot head assembly further comprises of a second translating link
3b also with three controlled degrees of freedom and an end
effector link 4 having four controlled degrees of freedom to be
explained further referring to FIGS. 3a and 3b. The said two, three
and four degrees of freedom of end effector link 4 are controlled
by motors 11, 12, 13, 14 driving respective motor shafts 15, 16,
17, 18 through motion transmission pulley stacks PS1, PS4 mounted
to frame F by shafts 19, 21 fixed at ends 20, 22 respectively;
pulley stacks PS3, PS4, PS5 mounted to y-axis frame member 1a by
fixed shafts 23, 24, 25 respectively, pulley belts 33, 34, 35, 36,
ball screw nut driver pulleys 69, 70, ball screw shafts 75, 77 and
idler tensioner pulleys mounted on supports 27, 28, 29, 30. A
gearbox 37 is used for motor 12 to increase torque. The end
effector link 4 uses these four degrees of freedom to manipulate
ingredient basket or container 5 by attaching to itself.
[0035] FIG. 2a is a three dimensional view and FIG. 2b. a top view,
both illustrating the motion transmission elements of the four axis
gantry robot mechanism shown in FIG. 1 in detail. Y-axis drive
pulley 65 is mounted onto shaft 15 (referring back to FIG. 1) which
is driven by motor 11. Y-axis drive pulley 65 drives a y-axis drive
belt 33 that loops around over y-axis idler near pulley 44 of
pulley stack PS1, y-axis idler far pulley of pulley stack PS4 and
pushed by y-axis idler tensioner pulley 57 mounted on support 27.
Since all the pulley and idler elements remain at rest with respect
to frame F the drive belt 33 loop around length is constant
regardless of the pulley motion or for any position. Referring back
to FIG. 1, y-axis belt 33 is attached to x-axis base member 1a and
so any rotation of y-axis motor 11 causes all the x-axis base
members 1a, 1b, 1c, guide rails 10a, 10b, 10c and any subsequent
members attached to them including robot head assembly R to
translate along y-axis. The members 33, 65, 44, 47 and 57 together
make a y-axis motion transmission layer.
[0036] Further, looking at FIGS. 2a and 2b, X-axis drive pulley 66
is mounted on shaft 16 (referring back to FIG. 1) which is driven
by driven by gearbox 37 using motor 12. X-axis drive pulley 66
drives a x-axis belt 34 that loops over around x-axis idler near
pulley 43 of pulley stack PS1, x-axis idler y-intermediate near
pulley 53 of pulley stack PS2, x-axis idler end pulley 50 of pulley
stack PS5, x-axis idler y-intermediate far pulley 56 of pulley
stack PS3, x-axis idler far pulley 46 of pulley stack PS4 and
x-axis tensioner pulley 58 mounted on support 28. With pulley
stacks PS1, PS4 are rotatable mounted to stationary frame F and
pulley stacks PS2, PS3, PS5 rotatable mounted to x-axis base
members and so moving along y-axis the closed loop around length of
x-axis pulley belt 34 is maintained same regardless of pulley
motion due to the reduction or increase in distance between pulley
stacks PS1, PS2 being compensated by an opposite increase or
reduction in pulley stacks PS3, PS4. Referring back to FIG. 1,
x-axis pulley belt 34 is attached to robot head assembly base 2
such that a rotation caused by motor 12 will result in a
translation of robot head assembly R along x-axis However due to
this arrangement there are interactions between y-axis motor
causing x-axis motion of robot head assembly even when x-axis motor
is not rotating and vice versa. So if a motion in either x-axis or
y-axis is desired then the other motor has to move in opposite
direction to nullify this effect. This means there is a transfer
matrix between motor x-axis and y-axis motion rotation and
subsequent linear translation seen along x-axis and y-axis for
robot head assembly R. The members 34, 43, 53, 50, 56 and 58
together make x-axis motion transmission layer.
[0037] Even further, looking at FIGS. 2a and 2b two additional
z-axis and tilt-axis transmission layers are formed similar to the
x-axis transmission layer. The z-axis transmission layer is made of
z-axis belt 35, z-axis drive pulley 67, z-axis idler pulley 59,
z-axis idler near pulley 42, z-axis idler y-intermediate near
pulley 52, z-axis idler end pulley 49, z-axis secondary far idler
pulley 63, z-axis ball screw nut driver pulley 70, z-axis secondary
near idler pulley 61, z-axis idler intermediate far pulley 55 and
z-axis idler far pulley 45. As will be explained in detail further
referring to additional figures pulleys 63, 69, 61 are all fixed in
position on robot head assembly base member and do not suffer from
any relative translation motion such that the z-axis belt length
changes between pulleys 49, 63 are compensated by equal and
opposite change between pulleys 61, 59.
[0038] Similar to z-axis transmission layer, the tilt-axis
transmission layer is made of tilt-axis belt 36, tilt-axis drive
pulley 68, tilt-axis idler pulley 60, tilt-axis idler near pulley
41, tilt-axis idler y-intermediate near pulley 51, tilt-axis idler
end pulley 48, tilt-axis secondary idler far pulley 62, tilt-axis
ball screw nut driver pulley 69, tilt-axis secondary near idler
pulley 64, tilt-axis idler intermediate far pulley 54 and tilt-axis
idler far pulley 44. As will be explained in detail further
referring to additional figures pulleys 62, 70, 64 are all fixed in
position on robot head assembly base member and do not suffer from
any relative translation motion such that the tilt-axis belt 36
length changes between pulleys 49, 63 are compensated by equal and
opposite change between pulleys 61, 59. Similar to the interactions
between x-axis and y-axis motor rotations versus robot head
translations, the z-axis and tilt-axis are also impacted. In fact
due to this stationary motor arrangement controlling the end
effector member 4 via the four transmission layer a four rows by
four columns translation matrix exists between the rotations of
motors and the motion produced along x, y, z and tilt axes. In
another embodiment the pulley and belt transmission are substituted
with a pair of ball screws connected via a worm gear mechanism.
[0039] FIGS. 3a and 3b illustrate the mechanism to convert the
rotation of z-axis ball screw nut driver pulley 70 attached to a
z-axis ball screw nut 76 connected with a z-axis hollow shaft 94
supported on robot head base assembly 2 by z-axis bearing 95 and
into vertical motion of first translating link 3a fixed onto z-axis
ball screw shaft 75 along z-axis. Further the rotation of tilt-axis
ball screw nut driver pulley 69 attached to a tilt-axis ball screw
nut 78 connected with a tilt-axis hollow shaft 92 supported on
robot head base assembly 2 by tilt-axis bearing 93 and into
vertical motion of second translating link 3b fixed onto tilt-axis
ball screw shaft 77. The end effector link 4 is connected to first
translating link by a hinge joint using bearings 85a and 85b on
each side and connected to the second translating link 3b by a
sliding joint using bearings made by slots 80a, 80b on the end
effector link 4 and bearings 84a, 84b mounted on second translating
link 3b. Each of the first translating link 3a and second
translating link 3b have an independent degree of freedom relative
to robot assembly base 2 controlled by motors 13, 14 allowing them
to be independently positioned along z-axis. This independent
positioning capability of the first translating link 3a and second
translating link 3b is converted into a z-axis and a tilt position
of end effector link 4. FIG. 3b when compared to FIG. 3a shows two
different z-axis and tilt positions for end effector link 4 with
respect to robot assembly base 2.
[0040] Further referring to FIG. 3a and FIG. 3b, a first linear
guide shaft assembly comprised of linear guide shaft 79, linear
guide bearing 81 connects first translating link assembly 3a to
robot assembly base 2 for added strength for moments in all
directions properly constraining first translating link 3a to move
along z-axis only with respect to robot assembly base 2. A second
linear guide shaft assembly comprised of linear guide shaft 82,
linear guide bearing 83 connects first translating link assembly 3a
to robot assembly base 2 for even more added mechanical
strength.
[0041] Continuing to refer to FIG. 3a and FIG. 3b, a locking
assembly mechanism is shown comprised of first locking pins 91a,
91b mounted on end effector link 4, second locking pins 92a and 92b
mounted on locking plate 89 supported on end effector link 4 by
locking plate guide shaft spring assembly 87a, 87b fixed to guide
shaft mounts 86a, 86b attached onto end effector link 4. Locking
plate 89 is able to move along the locking plate guide shaft spring
assembly 86a, 86b when pushed by locking plate guide rollers 90a,
90b away from the end effector link 4 along the guide shaft spring
assembly 87a, 87b. When no force is applied the locking plate 89
maintains continuous contact to the mating surface on the end
effector link 4 constrained by the guide shaft spring assembly 87a,
87b restoration forces. The first locking pins and second locking
pins are preferably perpendicular to each other.
[0042] FIG. 4. Illustrates and alternate embodiment with end
effector link 104 attached an end effector link gear 104a attached
to a z-axis ball screw shaft 175 by hinge joint bearing 104b, the
end effector link gear being driven by a worm 103b mounted on a
ball screw shaft 176. The end effector link has two controllable
degrees of freedom similar to end effector link 4.
[0043] FIG. 5. Shows a universal lift bar 95 attached to ingredient
basket 5 using screws 98. The universal lift bar has first lock pin
holes 96a, 96b and second lock pin holes 97a, 97b. The first lock
pin holes and second lock pin holes are preferably perpendicular to
each other. The universal lift bar can be attached to any target
object which is intended to be picked up and operated by the robot
head assembly R successfully regardless of the target objects shaft
or size as illustrated by FIG. 6a, FIG. 6b, FIG. 6c and FIG. 6d
depicting a picking sequence. FIG. 6a shows the relative positions
for robot head assembly R and universal lift bar 95 such that the
first locking pins 91a, 91b are lined up with the first lock pin
holes 96a, 96b. However the first locking pins and lock pin holes
cannot be engaged due to the second locking pins 92a, 92b coming in
the way of universal lift bar 95. FIG. 6b shows the relative
positions now with the locking plate guide rollers 90a, 90b running
into a base frame surface and pushed up to cause the locking plate
89, second locking pins 92a, 92b to move out of the way. The robot
head assembly R can now move towards the universal lift bar 95 and
successfully engage the first locking pins 91a, 91b into the first
lock pin holes 96a, 96b respectively as seen in FIG. 6c. In this
first set of locks engaged the second locking pins 92a, 92b are
also aligned up to the second pin holes 97a, 97b. As can be seen in
FIG. 6d the robot assembly R moves up allowing the locking plate
guide rollers 90a, 90b to go free causing the locking plate guide
89 restored to its normal position resting against the end effector
link 4 with the second set of locking pins and lock pin holes
engaged as can be seen in FIG. 6d.
[0044] The universal link bar 95 and ingredient basket 5 are now
fully secured to the robot head assembly R as seen in FIG. 1 or
FIG. 6d and will not drop for any position or tilt of the robot
head assembly R. Utilizing this locking mechanism by reuse of the
four degrees of freedom of the robot head assembly along with
motion restoring components eliminates the need to use additional
motorized, solenoid or pneumatic grippers and any resources such
additional electrical or pneumatic power sources, controls for such
gripping devices. It also eliminated cables or pneumatic lines to
be routed, connected and carried by the robot head assembly. This
also allows wash down capability for the robot head assembly R as
needed for food preparation equipment.
[0045] FIGS. 7a and 7b illustrate a mechanism for enhancing the
tilt angle range of end effector link 4 using a secondary end
effector link tilt multiplication pinion 100 mounted onto secondary
end effector link base 98 using a bearing. The secondary end
effector link base 98 is rigidly attached to the first translating
link 3a with a tilt multiplication gear 99 rigidly attached to end
effector link 4. Any tilt of the end effector link 4 relative to
the first translating link 3a causes an enhanced rotation of the
secondary end effector link pinion 100 decided by the ratio of
teeth of the gear pinion combination.
[0046] The end effector link 4 has four degrees of freedom along
with additional derived degrees of freedom by use of passive
elements and has been sown to be able to pick and transport and
ingredient basket 5. The end effector link 4 can also transport
other target objects permanently attached of via universal lift
bars attached to target objects such as a preferably wireless
camera, variation sensors including temperature measurement, air or
water delivery jets for cleaning etc.
[0047] In another embodiment shaking sequences on end effector link
4 are used for dispensing ingredients out of an ingredient basket
or container 5 by generating a shaking sequence by putting any or a
combination of input commands to motors 11, 12, 13, 14 for
reciprocating rotation at a desired frequency and amplitude.
[0048] All though the invention has been described herein in
connection with various preferred embodiments, there is no
intention to limit the invention to those embodiments. It should be
understood that various changes and modifications to the preferred
embodiments will be apparent to those skilled in the art. Such
changes and modifications may be made without departing from the
spirit and scope of the present invention and without diminishing
its attendant advantages. Therefore, the appended claims are
intended to cover such changes and modifications.
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