U.S. patent application number 10/403604 was filed with the patent office on 2003-12-18 for multi-spindle end effector.
Invention is credited to Carlson, Glen A. III.
Application Number | 20030232579 10/403604 |
Document ID | / |
Family ID | 26776816 |
Filed Date | 2003-12-18 |
United States Patent
Application |
20030232579 |
Kind Code |
A1 |
Carlson, Glen A. III |
December 18, 2003 |
Multi-spindle end effector
Abstract
A multi-spindle end effector is provided for a multiple axis
robot. The multi-spindle end effector includes a plate housing
having at least a pair of spaced-apart spindles mounted thereon. A
servo-motor drivingly engages the spindles. A gear box steps down
the RPMs of the motor to the desired RPM of the object to be
rotated. A timing belt, which may be continuous, interlinks the
first and second spindles so that the rotation of first spindle
matches the rotation of the second spindle. An idler pulley may be
employed to properly tension the belt.
Inventors: |
Carlson, Glen A. III;
(Birmingham, MI) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
26776816 |
Appl. No.: |
10/403604 |
Filed: |
March 31, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10403604 |
Mar 31, 2003 |
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10087293 |
Feb 28, 2002 |
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6638139 |
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60292240 |
May 18, 2001 |
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Current U.S.
Class: |
451/41 |
Current CPC
Class: |
B25J 11/0065 20130101;
B24B 27/0061 20130101; B24B 29/00 20130101; B23Q 5/043 20130101;
B23B 5/02 20130101; B25J 15/0019 20130101; B24B 41/04 20130101 |
Class at
Publication: |
451/41 |
International
Class: |
B24B 001/00 |
Claims
What is claimed is:
1. An end effector for a multiple axis robot comprising: a plate
housing adapted to connect to said robot; a plurality of spindles
rotatably coupled to said plate; a motor drivingly engaging at
least one of said spindles; and a synchronizer interconnecting said
spindles.
2. The end effector of claim 1, wherein the plate housing further
comprises: a base; and an annular rib coupled to said base.
3. The end effector of claim 1, wherein said plate housing includes
a recessed portion adapted to connect to said sixth axis of said
robot to selectively position a center of gravity of said end
effector.
4. The end effector of claim 1, further comprising a gear box
interconnecting said motor and said at least one of said plurality
of spindles.
5. The end effector of claim 1, further comprising a driving pulley
interconnecting said motor and said at least one of said plurality
of spindles by way of said synchronizer.
6. The end effector of claim 1, wherein said motor extends opposite
said at least one of said plurality of spindles relative to said
plate housing.
7. The end effector of claim 1, further comprising a spindle
housing rotatably interconnecting select ones of said plurality of
spindles to said plate housing.
8. The end effector of claim 7, wherein said spindle housing
extends opposite said select ones of said plurality of spindles
relative to said plate housing.
9. The end effector of claim 1, further comprising: a driving
pulley coupled to said at least one of said plurality of spindles;
and a driven pulley coupled to a remainder of said plurality of
spindles; wherein said driving pulley and said driven pulley are
interconnected by said synchronizer.
10. The end effector of claim 1, wherein said synchronizer further
comprises a belt.
11. The end effector of claim 1, further comprising an indexing
member coupled between each of said plurality of spindles and each
object to be rotated.
12. The end effector of claim 11, further comprising a locator
plate interposed between each of said indexing members and each of
said plurality of spindles, said locator plate having a
configuration matching a pattern of said objects to be rotated.
13. The end effector of claim 1, further comprising a wheel holder
assembly secured between each wheel to be rotated and each of said
plurality of spindles, said wheel holder assembly comprising: a
support arm coupled to said spindle; an outwardly biased piston
slidably coupled to said support arm and radially extending
relative to said spindle; and a moveable arm laterally extending
from a free end of said piston and engaging said wheel.
14. The end effector of claim 1, further comprising at least one
idler pulley rotatably and slidably mounted relative to said plate
housing and interconnected to said synchronizer.
15. The end effector of claim 14, wherein said idler pulley further
comprises: a jam nut having a shaft; a sleeve rotatably mounted on
said shaft; and a pulley wheel coupled to said sleeve, said sleeve
engaging said synchronizer.
16. The end effector of claim 1, wherein said plurality of spindles
are distributed along a common edge of said plate housing.
17. The end effector of claim 1, wherein said plurality of spindles
are distributed at select corners of said plate housing.
18. An end effector for a multiple axis robot comprising: a plate
housing adapted to connect to a sixth axis mounting surface of said
robot; a plurality of spindles rotatably mounted to said plate
housing, said plurality of spindles adapted to rotatably support a
plurality of objects to be rotated; a motor coupled to said plate
housing; a gear box drivingly connected to said motor; a driving
pulley coupled to said gear box; a belt coupled to said driving
pulley; and at least one driven pulley coupled to said driving
pulley.
19. The end effector of claim 18 further comprising at least one
idler pulley rotatably and slidably mounted relative to said
housing plate and engaging said belt.
20. An apparatus comprising: a robot having an end effector
mounting surface; and an end effector mounted to said end effector
mounting surface, said end effector including: a base; a plurality
of objects-to-be-rotated support members rotatably mounted to said
base; a motor drivingly engaging said plurality of mounting
members; and a rotation synchronizer interengaging said motor and
said plurality of support members.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/087,293, filed Feb. 29, 2002, which claims the benefit of
U.S. Provisional Application No. 60/292240 filed May 18, 2001. The
disclosure of the above application is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention generally relates to end effectors for
robotic units and, more particularly, to a multi-spindle end
effector for rotatably supporting multiple objects to be
rotated.
[0004] 2. Discussion
[0005] Many objects of manufacture require deburring, grinding,
buffing and/or polishing prior to being deemed acceptable as a
finished product. For example, many chrome parts, such as wheels
for automotive vehicles, motorcycle parts, and plumbing and lock
hardware, require such buffing and polishing. Manual performance of
these tasks is difficult and labor intensive.
[0006] To expedite the processing of such articles of manufacture,
automated polishing and buffing is sometimes employed. To date, the
most successful technique for polishing and buffing through an
automated mechanism involves the use of a six axis robot which
positions the object of manufacture adjacent polishing and/or
buffing wheels. A six axis robot is particularly well-suited for
this purpose since it can be programmed to move from a staging area
where a worker loads the object of manufacture onto the sixth axis
mounting surface of the robot. Thereafter, the robot moves the
object of manufacturer away from the staging area to a work area
where buffing and polishing are performed.
[0007] While such six axis robots have provided a vast improvement
over manual polishing and/or buffing, there is still room for
improvement in the art. For example, conventional buffing and
polishing robots are limited to manipulation of one object of
manufacture at a time. This limits production capacity.
[0008] In view of the foregoing, it would be desirable to provide
an automated mechanism for simultaneously processing a plurality of
objects of manufacture.
SUMMARY OF THE INVENTION
[0009] The above and other objects are provided by a multi-spindle
end effector for a six axis robot. The multi-spindle end effect or
includes a plate housing having at least a pair of spaced-apart
spindles mounted thereon. A servo-motor drivingly engages the
spindles. A gear box steps down the RPMs of the motor to the
desired RPM of the object to be rotated. A timing belt, which may
be continuous, interlinks the first and second spindles so that the
rotation of first spindle matches the rotation of the second
spindle. An idler pulley may be employed to properly tension the
belt.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In order to appreciate the manner in which the advantages
and objects of the invention are obtained, a more particular
description of the invention will be rendered by reference to
specific embodiments thereof which are illustrated in the appended
drawings. Understanding that these drawings only depict preferred
embodiments of the present invention and are not therefore to be
considered limiting in scope, the invention will be described and
explained with additional specificity and detail through the use of
the accompanying drawings in which:
[0011] FIG. 1 is a perspective view of a six axis robot suitable
for working in conjunction with the multi-spindle end effector of
the present invention;
[0012] FIG. 2 is a side view of the multiple spindle end effector
of the present invention;
[0013] FIG. 3 is a plan view of a wheel mounting mechanism of the
end effector of the present invention;
[0014] FIG. 4 is a plan view of the multi-spindle end effector of
the present invention;
[0015] FIG. 5 is a front view of the sixth axis mounting surface of
the robot illustrated in FIG. 1;
[0016] FIG. 6 is a side view of an idler pulley of the end effector
of the present invention;
[0017] FIG. 7 is a side view of the end effector of the present
invention coupled to the sixth axis mounting surface of the robot
in FIG. 1;
[0018] FIG. 8 is a plan view of a second embodiment multi-spindle
end effector of the present invention;
[0019] FIG. 9 is a side view of the multi-spindle end effector of
FIG. 8;
[0020] FIG. 10 is a bottom view of the multi-spindle end effector
of FIG. 8;
[0021] FIG. 11 is a side view of the multi-spindle end effector of
FIG. 8 coupled to the sixth axis mounting surface of the robot in
FIG. 1;
[0022] FIG. 12 is a plan view of a third embodiment multi-spindle
end effector of the present invention;
[0023] FIG. 13 is a plan view of a fourth embodiment multi-spindle
end effector of the present invention;
[0024] FIG. 14 is a plan view of a fifth embodiment multi-spindle
end effector of the present invention; and
[0025] FIG. 15 is a plan view of a sixth embodiment multi-spindle
end effector of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The following description of the preferred embodiments is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0027] The present invention is directed toward a multi-spindle end
effector for a six axis robot. The multi-spindle end effector
enables a plurality of objects of manufacture, such as wheels,
motorcycle parts, plumbing fixtures, and builders and lock hardware
to be simultaneously processed. For example, the multi-spindle end
effector of the present invention is well suited to simultaneously
rotate a pair of wheels for buffing and polishing.
[0028] Turning now to the drawing figures, FIG. 1 illustrates a six
axis robot 10 suitable for use in conjunction with the
multi-spindle end effector of the present invention. Although other
multi-axis robots may be suitable for use herein, it is presently
preferred to employ a FANUC Robotics S-430iW robot (165 Kg). This
robot operates well in confined spaces and can handle the payload
of the end effector. If a greater payload is required, other robots
may be used such as FANUC Robotics R2000 S-900iw (200 kg).
[0029] The robot 10 includes a first axis of movement 12, second
axis of movement 14, a third axis of movement 16, a fourth axis of
movement 18, a fifth axis of movement 20, and a sixth axis of
movement 22. The sixth axis of movement 22 enables a wrist 24 of
the robot 10 to rotate while the fifth axis of movement 20 enables
the wrist 24 to pivot. These ranges of motion are beneficial for
manipulating the end effector as described below.
[0030] Turning now to FIG. 2, an end effector assembly 26 is
illustrated coupled to the wrist 24 of the robot 10 illustrated in
FIG. 1. The end effector 26 includes a plate housing 28 which is
preferably formed as an aluminum weldment to minimize weight
without sacrificing strength. The plate housing 28 includes a base
30 surrounded by an integrally formed annular rib 32 (shown in
phantom). The annular rib 32 stiffens the plate housing 28 while
minimizing additional weight.
[0031] The base 30 includes a centralized recessed portion 34 where
the end effector 26 is fixedly secured, e.g., bolted, to the wrist
24. The recessed portion 34 positions the center of gravity of the
end effector 26 axially away from the distal end of the wrist 24.
This saves wear and tear on the robot 10 (FIG. 1).
[0032] The plate housing 28 rotatably supports a laterally
projecting first spindle 36 at one end and a laterally projecting
second spindle 38 at an opposite end. Preferably, the first spindle
36 and second spindle 38 are formed of aluminum to minimize weight
without sacrificing strength. The first and second spindles 36 and
38 preferably project parallel to one another and are spaced apart
by a sufficient amount to ensure clearance of the objects of
manufacture to be mounted thereto. For example, the preferred
embodiment of the present invention can rotatably support a pair of
vehicle wheels having diameters ranging from fourteen to twenty-six
inches or a wide range of other parts such as motorcycle and
plumbing fixtures.
[0033] The first spindle 36 is drivingly connected to one end of a
gear box 40 mounted to the plate housing 28. A second end of the
gear box 40 is drivenly connected to a drive shaft of a servo-motor
42. As such, rotation of the drive shaft of the servo-motor 42 is
transferred through the gear box 40 to the first spindle 36.
[0034] The servo-motor 42 provides a seventh axis of rotation for
the robot 10 (FIG. 1). To minimize the weight extending beyond the
end of the wrist 24, the servo-motor 42 preferably extends opposite
the first spindle 36 relative to the plate housing 28. Although
other motors may be suitable for use herein, it is presently
preferred to employ a Fanuc Alpha 6/3000 motor. Larger motors may
also be used. A 1.9 HP version of this motor preferably includes a
straight drive shaft and a brake and has a speed of up to 3000
RPMs. The motor 42 is controllable to start and stop, index, "free
wheel", or reverse the objects coupled thereto.
[0035] The gear box 40 reduces the RPMs of the motor 42 transferred
to the first spindle 36. While different articles of manufacture
require different RPMs depending on their final processing needs,
it is presently preferred to reduce the RPMs of the first spindle
36 to a range of between 0 and 50 RPMs. Although other gear boxes
may be suitable for use herein, it is presently preferred to employ
an Alpha Gear TP 050 Gearhead reducer. Variant 1 of this two stage
gearbox preferably has a reduction ratio of about 61:1.
[0036] The second spindle 38 is rotatably supported relative to the
plate housing 28 by a spindle housing 44. To minimize the weight
extending beyond the end of the wrist 24, the spindle housing 44
preferably extends opposite the second spindle 38 relative to the
plate housing 28. The spindle housing 44 includes a shroud 46 and a
shaft 48 rotatably supported by a pair of steel bearings 50. A
driven pulley 52 (described below) is non-rotatably secured, e.g.,
splined, to the shaft 48.
[0037] A driving pulley 56 is non-rotatably connected, e.g.,
splined, to the first spindle 36. A synchronizer in the form of a
timing belt 58 meshingly engages the driving pulley 56 and driven
pulley 52 such that they are interconnected. The belt 58 preferably
consists of rubber and includes teeth distributed thereabout. The
belt 58 transfers the rotation of the first spindle 36 by the motor
42 (and gear box 40) to the second spindle 38 at a one-to-one ratio
such that the rotation of the spindles 36 and 38, as well as the
objects of manufacture mounted thereto, is matched. To save weight,
the driving pulley 56 and driven pulley 52 are preferably formed of
aluminum.
[0038] A first object of manufacture in the form of an aluminum
wheel 60 is non-rotatably connected to the first spindle 36 by a
first pin 62. The first pin 62 passes through a central orifice 64
in a locator plate 66 and frictionally wedges within an axial bore
68 of the first spindle 36. A locating/indexing member 70
interengages the locator plate 66 and the wheel 60 to ensure that
the wheel 60 adopts a pre-selected orientation when mounted to the
end effector 26. Preferably, different locator plates are employed
depending upon the configuration of the object of manufacture to be
secured to the end effector 26. For example, complimentary bolt
patterns should be ensured.
[0039] A wheel holder assembly 72 further secures the wheel 60 to
the first spindle 36. Referring now to FIG. 3, a detailed
illustration of the wheel holder assembly 72 is illustrated. If
another object of manufacture was to be supported on the end
effector, the wheel holder assembly 72 may not be necessary.
[0040] The wheel holder assembly 72 includes a support arm 74
mounted to the locator plate 66. The support arm 74 includes a
support 76 slidably supporting a radially extending piston 78. The
piston 78 is biased in an outboard direction by a biasing member in
the form of a spring 80. A moveable arm 82 laterally extends from a
free end of the piston 78. In a first position, the distal end 86
of the arm abuttingly engages an edge of the wheel 60 to secure it
in place while being processed. In a second position, the wheel 60
can be removed.
[0041] Referring again to FIG. 2, a second object of manufacture in
the form of a wheel 90 is mounted to the second spindle 38. A
second pin 92 passes through a central orifice 94 in a locator
plate 96 and frictionally wedges within an axial bore 98 of the
second spindle 38. A locating/indexing member 100 interengages the
locator plate 96 and the wheel 90 to ensure that the wheel 90
adopts a pre-selected orientation (i.e., matching that of the first
wheel 60) when mounted to the end effector 26. A wheel holder
assembly 102, which is preferably identical to the wheel holder 72
described above, further supports the wheel 90 relative to the
second spindle 38.
[0042] Turning now to FIG. 4, a front view of the end effector 26
is illustrated. The plate housing 28 is generally shaped as an
offset diamond and includes a plurality of elongated ribs 104 for
added strength. The plate housing 28 also includes a plurality of
mounting holes, generally shown at 106, in the recessed portion 34
for accommodating fasteners such as bolts to secure the end
effector 26 to the wrist 24 of the robot 10 (FIG. 1).
[0043] Referring to FIG. 5, the wrist 24 has a pre-selected bolt
pattern 107 to which the mounting holes 106 (FIG. 4) are designed
to match.
[0044] Referring again to FIG. 4, a pair of idler pulleys 108 and
110 are rotatably and slidably mounted to a pair of slots 112 and
114 formed in the base 30 of the end effector 26. By selectively
positioning the pair of idler pulleys 108 and 110 along their
respective slots 112 and 114, the tension of the belt 58, which
synchronizes the rotation of the first wheel 60 and second wheel
90, is controlled. Maintaining proper tensioning on the belt 58
prevents belt slippage to ensure that the wheels 60 and 90 rotate
in phase.
[0045] Turning to FIG. 6, the idler pulley 108 is illustrated in
greater detail. Although only idler pulley 108 is illustrated, the
idler pulley 110 (FIG. 4) is preferably identical thereto. The
idler pulley 108 includes a sleeve 116 rotatably mounted on a shaft
118 of a jam nut 120. An aluminum pulley wheel 122 is coupled to
the sleeve 116 and accommodates the belt 58. The jam nut 120 is
selectively positionable along the slot 112 such that a desired
tension can be placed on the belt 58 and then the idler pulley 108
can be locked in place.
[0046] Turning now to FIG. 7, a side view of the end effector 26 is
illustrated with the wrist 24 of the robot 10 (FIG. 1). By
vertically pivoting the wrist 24 about the fifth axis of movement
20, the end effector 26 can be moved in an arc. This is
advantageous for positioning the objects of manufacture relative to
buffing and/or polishing stations. Further, the end effector 26 can
be rotated by rotating the wrist 24 about the sixth axis of
movement 22.
[0047] Referring now collectively to all the FIGS. 1-7, in
operation, the robot 10 is programmed to position the end effector
26 at a loading station. An operator loads the wheels 60 and 90
onto the first and second spindles 36 and 38 respectively. By using
the locating members 70 and 100, the wheels 60 and 90 are commonly
aligned. Thereafter, the robot 10 positions the wheels 60 and 90
adjacent select buffers. The servo-motor 42 rotates the first
spindle 36 and wheel 60 by way of the gear box 40. The rotation of
the spindle 36 is transferred to the second spindle 38 by way of
the driving pulley 56, belt 58, and driven pulley 52. Since the
first and second spindles 36 and 38 are interconnected by the belt
58, the rotation of the wheels 60 and 90 is synchronized. After
polishing and/or buffing, the wheels 60 and 90 are removed.
[0048] Turning now to FIGS. 8-10 a second embodiment end effector
according to the present invention is illustrated. Whereas the
first embodiment of FIGS. 2-7 is particularly tailored to
accommodate two objects to be rotated, the second embodiment is
particularly tailored to accommodate four objects to be
rotated.
[0049] The second embodiment end effector assembly 226 includes a
plate housing 228 which is preferably formed as an aluminum
weldment to minimize weight without sacrificing strength. As most
clearly illustrate in FIG. 9, the plate housing 228 includes a base
230 surrounded by an integrally formed annular rib 232. The annular
rib 232 stiffens the plate housing 228 while minimizing additional
weight.
[0050] The base 230 includes a centralized portion 234 where the
end effector 226 is fixedly secured, e.g., bolted, to the wrist
224. If desired, the portion 234 may be recessed relative to the
base 230 to position the center of gravity of the end effector 226
axially away from the distal end of the wrist 224. This may save
wear and tear on the robot 10 (FIG. 1).
[0051] The plate housing 228 rotatably supports a plurality of
objects to be rotated (not shown) by way of a plurality of
laterally projecting spindles 236a-d. The spindles 236a-d are
preferably distributed along a common edge of the plate housing
228. The spindles 236a-d are preferably formed of aluminum to
minimize weight without sacrificing strength. The spindles 236a-d
preferably project parallel to one another and are spaced apart by
a sufficient amount to ensure clearance of the objects of
manufacture to be mounted thereto. For example, this embodiment of
the present invention can rotatably support four of vehicle wheels
having diameters ranging from fourteen to twenty-six inches.
[0052] A gear box 240 is mounted to the plate housing 228. A
servo-motor 242 is drivingly connected through a gear box 240 to a
driving pulley 256. Rotation of the drive shaft of the servo-motor
242 is transferred through the gear box 240 to the driving pulley
256. The servo-motor 242 provides a seventh axis of rotation for
the robot 10 (FIG. 1).
[0053] To minimize the weight extending beyond the end of the wrist
224, the servo-motor 242 preferably extends opposite the driving
pulley 256 relative to the plate housing 28. Although other motors
may be suitable for use in this embodiment, it is presently
preferred to employ a Fanuc Alpha 6/3000 motor. A 1.9 HP version of
this motor preferably includes a straight drive shaft and a brake
and has a speed of up to 3000 RPMs. The motor 242 is controllable
to start and stop, index, "free wheel", or reverse the objects
coupled thereto.
[0054] The gear box 240 reduces the RPMs of the motor 242
transferred to the driving pulley 256. While different articles of
manufacture require different RPMs depending on their final
processing needs, it is presently preferred to reduce the RPMs of
the driving pulley 256 to a range of between 0 and 50 RPMs.
Although other gear boxes may be suitable for use herein, it is
presently preferred to employ an Alpha Gear TP 050 Gearhead
reducer. Variant 1 of this two stage gearbox preferably has a
reduction ratio of about 61:1.
[0055] The spindles 236a-d are rotatably supported relative to the
plate housing 228 by a plurality of spindle housings 244a-d. To
minimize the weight extending beyond the end of the wrist 224, the
spindle housings 244a-d preferably extend opposite the spindles 236
relative to the plate housing 228. Each of the spindle housings
244a-d includes a shroud 246 and a shaft 248.
[0056] A driven pulley 252 (described below) is non-rotatably
secured, e.g., splined, to each of the shafts 248. A driving pulley
256 is non-rotatably connected, e.g., splined, to the motor 242 by
way of the gear box 240. A synchronizer in the form of a timing
belt 258 meshingly engages the driving pulley 256 and driven
pulleys 252 such that they are interconnected. The belt 258
preferably consists of rubber and includes teeth distributed
thereabout.
[0057] The belt 258 transfers the rotation of the driving pulley
256 by the motor 242 (and gear box 240) to the spindles 236a-d at a
one-to-one ratio such that the rotation of the spindles 236a-d, as
well as the objects of manufacture mounted thereto, is matched. To
save weight, the driving pulley 256 and driven pulleys 252 are
preferably formed of aluminum.
[0058] An object of manufacture such as the aluminum wheels of the
first embodiment are non-rotatably connected to each of the
spindles 236. For clarity, these objects of manufacture are not
illustrated in FIGS. 8-10. Nonetheless, one skilled in the art will
readily appreciate that they are preferably coupled thereto as
described above. When mounted, each wheel adopts a pre-selected
orientation when mounted to the end effector 226.
[0059] As best seen in FIG. 8, the plate housing 228 is generally
shaped as a triangle and may include one or more elongated ribs 204
for added strength. The plate housing 228 also includes a plurality
of mounting holes, generally shown at 206 in the portion 234 for
accommodating fasteners such as bolts to secure the end effector
226 to the wrist 224. The wrist 224 will generally have a
pre-selected bolt pattern to which the mounting holes 206 are
designed to match.
[0060] As shown in FIGS. 8-10, a plurality of idler pulleys 208a
and b are rotatably and slidably separately mounted to a plurality
of slots 212a and b formed in the base 230 of the end effector 226.
By selectively positioning the idler pulleys 208a and b along each
respective slots 212a and b, the tension of the belt 258, which
synchronizes the rotation of the driven pulleys 252a-d, is
controlled. Maintaining proper tensioning on the belt 258 prevents
belt slippage to ensure that the objects to be rotated rotate in
phase. As one skilled in the art will appreciate, the idler pulleys
108a and b are preferably constructed as described above.
[0061] Turning now to FIG. 11, a side view of the end effector 226
is illustrated with the wrist 224 of the robot 10 (FIG. 1). By
vertically pivoting the wrist 224 about the fifth axis of movement
20, the end effector 226 can be moved in an arc. This is
advantageous for positioning the objects of manufacture relative to
buffing and/or polishing stations. Further, the end effector 226
can be rotated by rotating the wrist 224 about the sixth axis of
movement 22.
[0062] Turning now to FIG. 12, a third embodiment of the present
invention is illustrated. This embodiment is particularly tailored
to accommodate three objects to be rotated. The third embodiment is
similar in principle to the prior embodiments but includes three
mounting positions for accommodating the objects to be rotated.
[0063] More particularly, the third embodiment end effector
assembly 326 includes a plate housing 328 which is preferably
formed as an aluminum weldment to minimize weight without
sacrificing strength and may include ribs for added strength. The
plate housing 328 includes a centralized portion 334 where the end
effector 326 is fixedly secured, e.g., bolted, to the wrist 324. If
desired, the portion 334 may be recessed position the center of
gravity of the end effector 326 axially away from the distal end of
the wrist 324. This may save wear and tear on the robot 10 (FIG.
1).
[0064] The plate housing 328 rotatably supports a plurality of
objects to be rotated by way of a plurality of spindles 336a-c. The
spindles 336a-d are preferably distributed along a common edge of
the plate housing 328 and are coupled to spindle housings as
described above. The spindles 336a-d preferably project parallel to
one another and are spaced apart by a sufficient amount to ensure
clearance of the objects of manufacture to be mounted thereto. For
example, this embodiment of the present invention can rotatably
support three vehicle wheels having diameters ranging from fourteen
to twenty-six inches.
[0065] A driving pulley 356 is rotatably mounted to the plate
housing 328 and is operably coupled to a gear box and servo motor
as described above. A driven pulley 352 is non-rotatably secured,
e.g., splined, to each of the spindles 336a-c. A synchronizer in
the form of a timing belt (not shown) meshingly engages the driving
pulley 356 and driven pulleys 352 such that they are
interconnected.
[0066] The belt transfers the rotation of the driving pulley 356 by
the motor and gear box to the spindles 336a-c at a one-to-one ratio
such that the rotation of the spindles 336a-d, as well as the
objects of manufacture mounted thereto, is matched. An object of
manufacture such as the aluminum wheels of the first embodiment are
non-rotatably connected to each of the spindles 336. For clarity,
these objects of manufacture are not illustrated in FIG. 11.
[0067] The plate housing 328 is generally shaped as a triangle and
includes a plurality of mounting holes, generally shown at 306, in
the portion 334 for accommodating fasteners such as bolts to secure
the end effector 326 to the wrist 324. If desired, one or more
idler pulleys (not shown) may be rotatably and slidably separately
mounted to a the plate housing 328. By selectively positioning such
idler pulleys relative to the spindles 336a-c, the tension of the
belt, which synchronizes the rotation of the driven pulleys 352, is
controlled. Maintaining proper tensioning on the belt prevents belt
slippage to ensure that the objects to be rotated rotate in
phase.
[0068] Turning now to FIG. 13, a fourth embodiment of the present
invention is illustrated. This embodiment is particularly tailored
to accommodate five objects to be rotated. The fourth embodiment is
identical in principle to the prior embodiments; but includes five
mounting positions for accommodating the objects to be rotated.
[0069] More particularly, the fourth embodiment end effector
assembly 426 includes a plate housing 428. The plate housing 428
includes a centralized portion 434 where the end effector 426 is
fixedly secured, e.g., bolted, to the wrist 424. The plate housing
428 rotatably supports a plurality of objects to be rotated by way
of a plurality of spindles 436a-e.
[0070] The spindles 436a-e are preferably distributed along a
common edge of the plate housing 428 and are coupled to spindle
housings as described above. The spindles 436a-e preferably project
parallel to one another and are spaced apart by a sufficient amount
to ensure clearance of the objects of manufacture to be mounted
thereto. For example, this embodiment of the present invention can
rotatably support five vehicle wheels having diameters ranging from
fourteen to twenty-six inches.
[0071] A driving pulley 456 is rotatably mounted to the plate
housing 428 and is operably coupled to a gear box and servo motor
as described above. A driven pulley 452 is non-rotatably secured,
e.g., splined, to each of the spindles 436a-e. A synchronizer in
the form of a timing belt (not shown) meshingly engages the driving
pulley 456 and driven pulleys 452 such that they are
interconnected. The belt transfers the rotation of the driving
pulley 456 by the motor and gear box to the spindles 436a-e at a
one-to-one ratio such that the rotation of the spindles 436a-e, as
well as the objects of manufacture mounted thereto, is matched.
[0072] The plate housing 428 is generally shaped as a triangle and
includes a plurality of mounting holes, generally shown at 406, in
the portion 434 for accommodating fasteners such as bolts to secure
the end effector 426 to the wrist 424. If desired, one or more
idler pulleys (not shown) may be rotatably and slidably separately
mounted to a the plate housing 428. By selectively positioning such
idler pulleys relative to the spindles 436a-e, the tension of the
belt, which synchronizes the rotation of the driven pulleys 452, is
controlled. Maintaining proper tensioning on the belt prevents belt
slippage to ensure that the objects to be rotated rotate in
phase.
[0073] Turning now to FIG. 14, a fifth embodiment of the present
invention is illustrated. This embodiment is particularly tailored
to accommodate six objects to be rotated. The fifth embodiment is
identical in principle to the prior embodiments but includes six
mounting positions for accommodating the objects to be rotated.
[0074] More particularly, the fifth embodiment end effector
assembly 526 includes a plate housing 528. The plate housing 528
includes a centralized portion 534 where the end effector 526 is
fixedly secured, e.g., bolted, to the wrist 524. The plate housing
528 rotatably supports a plurality of objects to be rotated by way
of a plurality of spindles 536a-f.
[0075] The spindles 536a-f are preferably distributed along a
common edge of the plate housing 528 and are coupled to spindle
housings as described above. The spindles 536a-f preferably project
parallel to one another and are spaced apart by a sufficient amount
to ensure clearance of the objects of manufacture to be mounted
thereto. For example, this embodiment of the present invention can
rotatably support six vehicle wheels having diameters ranging from
fourteen to twenty-six inches.
[0076] A driving pulley 556 is rotatably mounted to the plate
housing 528 and is operably coupled to a gear box and servo motor
as described above. A driven pulley 552 is non-rotatably secured,
e.g., splined, to each of the spindles 536a-f. A synchronizer in
the form of a timing belt (not shown) meshingly engages the driving
pulley 556 and driven pulleys 552 such that they are
interconnected. The belt transfers the rotation of the driving
pulley 556 by the motor and gear box to the spindles 536a-f at a
one-to-one ratio such that the rotation of the spindles 536a-f, as
well as the objects of manufacture mounted thereto, is matched.
[0077] The plate housing 528 is generally shaped as a triangle and
includes a plurality of mounting holes, generally shown at 506, in
the portion 534 for accommodating fasteners such as bolts to secure
the end effector 526 to the wrist 524. If desired, one or more
idler pulleys (not shown) may be rotatably and slidably separately
mounted to a the plate housing 528. By selectively positioning such
idler pulleys relative to the spindles 536a-f, the tension of the
belt, which synchronizes the rotation of the driven pulleys 552, is
controlled. Maintaining proper tensioning on the belt prevents belt
slippage to ensure that the objects to be rotated rotate in
phase.
[0078] Turning now to FIG. 15, a sixth embodiment of the present
invention is illustrated. This embodiment is particularly tailored
to accommodate seven objects to be rotated. The sixth embodiment is
identical in principle to the prior embodiments but includes seven
mounting positions for accommodating the objects to be rotated.
[0079] More particularly, the sixth embodiment end effector
assembly 626 includes a plate housing 628. The plate housing 628
includes a centralized portion 634 where the end effector 626 is
fixedly secured, e.g., bolted, to the wrist 624. The plate housing
628 rotatably supports a plurality of objects to be rotated by way
of a plurality of spindles 636a-g.
[0080] The spindles 636a-g are preferably distributed along a
common edge of the plate housing 628 and are coupled to spindle
housings as described above. The spindles 636a-g preferably project
parallel to one another and are spaced apart by a sufficient amount
to ensure clearance of the objects of manufacture to be mounted
thereto. For example, this embodiment of the present invention can
rotatably support seven vehicle wheels having diameters ranging
from fourteen to twenty-six inches.
[0081] A driving pulley 656 is rotatably mounted to the plate
housing 628 and is operably coupled to a gear box and servo motor
as described above. A driven pulley 652 is non-rotatably secured,
e.g., splined, to each of the spindles 636a-g. A synchronizer in
the form of a timing belt (not shown) meshingly engages the driving
pulley 656 and driven pulleys 652 such that they are
interconnected. The belt transfers the rotation of the driving
pulley 656 by the motor and gear box to the spindles 636a-g at a
one-to-one ratio such that the rotation of the spindles 636a-g, as
well as the objects of manufacture mounted thereto, is matched.
[0082] The plate housing 628 is generally shaped as a triangle and
includes a plurality of mounting holes, generally shown at 606, in
the portion 634 for accommodating fasteners such as bolts to secure
the end effector 626 to the wrist 624. If desired, one or more
idler pulleys (not shown) may be rotatably and slidably separately
mounted to a the plate housing 628. By selectively positioning such
idler pulleys relative to the spindles 636a-g, the tension of the
belt, which synchronizes the rotation of the driven pulleys 652, is
controlled. Maintaining proper tensioning on the belt prevents belt
slippage to ensure that the objects to be rotated rotate in
phase.
[0083] Thus, an end effector is provided for a six axis robot which
accommodates a plurality of objects to be rotated. The end effector
interconnects each object to be rotated such that they are
synchronized and indexable as a unit. Advantageously, multiple
objects of manufacture can be simultaneously processed with the end
effector of the present invention.
[0084] The description of the invention is merely exemplary in
nature and, thus, variations that do not depart from the gist of
the invention are intended to be within the scope of the invention.
Such variations are not to be regarded as a departure from the
spirit and scope of the invention. For example, the particular
geometry of the mounting plate can be varied to accommodate the
objects to be rotated in a modified distribution.
* * * * *