Note: Descriptions are shown in the official language in which they were submitted.
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VALVE STEM INSTALLATION SYSTEM AND
METHOD OF INSTALLING VALVE STEM
RELATED APPLICATIONS
[0001] This application claims the benefit of the provisional patent
application 60/453,262 for a VALVE STEM INSTALLATI~N SYSTEM AN7~
METH~D ~F INSTALLING VALVE STEM, filed on March 10, 2003, and claims the
benefit of the provisional patent application 60/460,153 for a TIRE PRESSURE
M~NIT~RING VALVE STEM 1NSTALLATI~N SYSTEM AND METH~I~ ~F
INSTALLING TIRE PRESSURE M~NITORING VALVE STEM, filed April 3, 2003,
which are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
[0002] The subject invention relates to the assembly of wheels, and more
particularly to an apparatus and method for locating a valve stem aperture in
a wheel and
mounting the valve stem to the wheel.
BACKGROUND OF THE INVENTION
[0003] In the past, a valve stem was manually mounted to a wheel with
a stem-iliserting tool. Such manual processes are expensive because of the
labor and
time involved. In addition, operations performed manually axe subject to a
relatively
greater frequency of processing errors in comparison to robot-performed
processes.
[0004] Several prior art patents disclose processes for mounting a valve
stem to a wheel with programmable machines. For example, U.S. Patent No.
6,481,083
teaches a valve stem assembly line that includes an input conveyor to supply
wheels, a
locator station positioned at the end of the input conveyor to locate the
valve stem
aperture defined by the wheel, and a robotic manipulator to grasp the wheel in
the
locator station and to move the wheel to the mounting station where a valve
stem is
inserted. U.S. Patent No. 6,026,552 teaches a spinning device to spin the
wheel, an
optical sensor to locate the valve stem aperture while the wheel is spinning,
and press
fitting device that can slide relative to a wheel and insert a valve stem
after the valve
stem aperture has been located. U.S. Patent No. 5,940,960 teaches and
automatic valve
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stemming apparatus including a spinning device to spin the wheel, an optical
sensor to
locate the valve stem aperture, and a valve stem insertion tool to insert a
valve stem after
the valve stem aperture has been located.
[0005] One of the areas of continuous development and research is the
pursuit of flexible systems operable to receive and process several
differently configured
rims. Another area is the pursuit of less costly valve stem insertion devices.
Costliness
can be defined by the capital investment required for putting the valve stem
insertion
system on the factory floor as well as the operating cost associated with the
system. In
pursuit of these goals, it would be desirable to develop a valve stem
insertion system
having improved flexibility, cost and efficiency.
BRIEF SUMMARY OF INVENTION
[0006] a The invention provides an apparatus and method for locating a
valve stem aperture in a wheel and inserting the valve stem in the valve stem
aperture.
The valve stem and the valve stem aperture are moved relative to one another
at a
predetermined relative speed in a first rotational direction along a craved
path of the
wheel perimeter to align the valve stem with the valve stern aperture. The
valve stem is
supported with a pin and the pin is moved around the wheel with a robotic
apparatus. A
first sensor locates the valve stem apeuture when the valve stem and the valve
stem
aperture are a first angular distance from one another along the curved path.
In response
to the first sensor locating the valve stem aperture, the relative speed of
movement
between the valve stem and the valve stem aperhue is reduced. A second sensor
locates
the valve stem aperture when the valve stem and the valve stem aperture are a
first
angular distance from one another along the curved path.
[0007] One of the advantages of the present invention is that processing
time for inserting the valve stem in the valve stem aperture is reduced.
Specifically, the
relative movement between the valve stem and the valve stem aperture can be
maximized prior to the locating step and the first and second sensor can be
spaced from
one another to accommodate the braking capacity of the system. In other words,
the
invention substantially eliminates time delays associated with confirming the
location of
the valve stem aperture that are common in prior art locating systems.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference to the
following detailed
description when considered in connection with the accompanying drawings
wherein:
[000] Figure 1 is an overhead schematic view of a valve stem
installation system according to the exemplary embodiment of the invention;
[0010] Figure 2 is a side view of an identification station for the valve
stem installation system shown in Figure 1 for identifying an individual wheel
from a
plurality of differently configured wheels;
[0011] Figure 3 is a top view of a portion of the valve stem installation
system shown in Figures 1 and 2 showing pin stop assemblies positioned along a
roller
conveyor for preventing movement of a wheel along the roller conveyor;
[0012] Figure 4 is a partial cross-sectional view of the valve stem
installation system shown in Figures 1-3 showing a positioning device for
positioning a
wheel and a locating and inserting assembly for inserting a valve stem in a
valve stem
aperture defined by a wheel;
[0013] Figures 5 is a partial cross-sectional view of the valve stem
installation system shown in Figures 1-4 and offset ninety degrees fiom the
view in
Figure 4, showing the positioning device and the locating and inserting
assembly;
[0014] Figure 6 is a side view of the valve stem installation system
shown in Figure 1 with additional structural details; and
[0015] Figure 7- 10 are perspective views illustrating a sequence of
locating a valve stem aperture and inserting a valve stem in the valve stem
aperture.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring now to Figure 1, the present invention provides a
method and apparatus 10 for inserting a valve stem in a valve stem aperture
defined by a
wheel. The apparatus 10 includes a conveyor 12 for moving wheels 14 past a
robotic
apparatus 16. Valve stems are inserted in the valve stem aperture defined by
the wheel
14 by the robotic apparatus 16. Wheels 14 can be received at a beginning 18 of
the
conveyor 12 and move in a direction 20 to an end 22 of the conveyor 12.
[0017] Referring now to Figures 1 and 2, during movement of the wheel
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I4 between the beginning I8 and end 22 of the conveyor 12, the wheel 14 passes
through an identification station 24. The identification station 24 can
include a camera
26 for identifying the wheel 14 from a plurality of differently configured
wheels. When
a wheel 14 moves within the visual range of the camera 26, the camera 26
communicates
an image of the wheel 14~ to a controller 28. The image includes structural
features of
the wheel 14 including the position of the valve stem aperture. The controller
28
compares the image received from the camera 26 with a plurality of images
stored in
memory. The images in memory correspond to all of the differently configured
wheels
that can pass through the identification station 24. Each of the images stored
in memory
is associated with structural characteristics and physical dimensions of a
corresponding
wheel I4. The controller 28 controls processing steps performed downstream of
the
identification station 24 based, at least in part, on the physical dimensions
of the wheel
14 identified from the image received from the camera 26.
[0018] Referring now to Figures 1 and 3, the conveyor 12 includes
clutch-assisted, driven rollers 30 to move the wheel 14 from the
identification station 24
to a first position 32 along the conveyor 12. The wheel 14 can move along the
conveyor
I2 in the direction 20 until the wheel 14 engages a pair of pin stops 34, 36.
The
conveyor 12 includes undriven rollers 38 between the first position 32 and the
pin stops
34, 36. The pin stops 34, 36 are actuated between an extended position above
the
conveyor 12 and a retracted position below the conveyor 12 to stop movement of
the
wheel I4 in the direction 20 along the conveyor 12. The pin stops 34, 36 are
controlled
in movement by the controller 28. Sensors (not shown) are positioned along the
conveyor I2 to sense the position of the wheel 14 along the conveyor 12 and
communicate the sensed position of the wheel I4 to the controller 28.
[0019] Referring now to Figures 1 and 3-5, a positioning device 40 is
disposed along the conveyor 12 adjacent the robotic apparatus 16. The
positioning
device 40 includes a first positioning mechanism 42 and a second positioning
mechanism 44. The positioning mechanisms 42, 44 are substantially similar with
respect to one another and are disposed along the conveyor 12 between the frst
position
32 and a second position 46. The first positioning mechanism 42 includes a
housing 47.
The housing 47 defines apertures 48, SO and 52 for receiving guide tracks 54,
56 and 58,
respectively as best seen in figures 4~ and 5. The guide tracks 54, 56 and 58
guide
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movement of the housing 48 along the conveyor 12. A metal piston (not shown)
is
disposed internally of the guide track 58 and cooperate magnetically with the
housing
48. For example, the housing 48 houses a magnet to attract the metal piston in
the guide
track 58. The piston is moved by selectively directing pressurized air to
opposite sides
of the piston in the guide track 58. The housing 4~8 moves in response to
movement of
the piston. The second positioning mechanism 44 is structured similarly and
function
similarly as the first positioning mechanism 4~2. For example, the second
positioning
mechanism 44 includes a housing 60 defining apertures 62, 64, 66 for receiving
guide
tracks 68, 70, 72, respectively, as best shown in figures 4 and 5. A metal
piston is
disposed internally of the guide track 72 and cooperates with the housing 60
to move the
housing 60 along the conveyor 12. Movement of the pistons inside the tracks
58, 72 are
controlled by the controller 28.
[0020] Refen-ing now to Figures 3-5, the first positioning mechanism 42
includes an engaging device 74 for engaging and moving the wheel 14 along the
conveyor 12. The engaging device 74 is connected to the housing 47 and
includes an
arm 76 rotatable about an axis 78. An engaging portion 80 is disposed at the
end of the
arm 76 and is shaped to correspond to the shape of the wheel 14. During
movement of
the housing 47 along the conveyor 12 in the direction 20, the arm 76 is
located in a first
position shown in solid line in Figure 4. After the housing 47 has moved a
predetermined distance along the conveyor 12 in the direction 20, the arm 76
is moved
to a second position shown in phantom in Figure 4. The arm 76 is moved to the
second
position to prevent the engaging portion 80 from interfering with movement of
a
following wheel moving along the conveyor 12 and is therefore positioned below
the
conveyor 12. The positioning device 42 moves the wheel 14 along the conveyor
12 to a
position along the conveyor 12 at which the second positioning mechanism 44
can
engage the wheel 14. The second positioning mechanism 44 includes an engaging
device 82 structured similarly and functioning similarly as the first engaging
device 74.
For example, the engaging device 82 includes an arm 84 rotatable about an axis
86 and
an engaging portion 88 positioned at the end of the arm 84. The second
positioning
mechanism 44 moves the wheel 14 away from the robotic apparatus 16 after a
valve
stem has been inserted in the valve stem aperture defined by the wheel, a
process
described in greater detail below. ~nce the second positioning mechanism 44
moves the
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wheel 14, the first positioning mechanism 42 moves a second wheel 14 along the
conveyor 12 until the second wheel 14 engages a second pair of pin stops 90,
92.
[0021] Referring now to Figures 1 and 6, after the wheel 14 is positioned
adjacent the robotic apparatus 16 by the positioning device 40, the robotic
apparatus 16
inserts a valve stem in the valve stem aperture defined by the wheel 14. The
robotic
apparatus 16 moves a locating and inserting assembly 90 around the wheel 14,
shown
schematically in Figures 1 and 6. The assembly 90 receives valve stems from
one or
more valve stem feeding stations 92 disposed along the conveyor 12. Each
station 92
includes a hopper 94 for receiving valve stems and a sorting device 96 for
sorting the
valve stems and arranging the valve stems in an orientation to be received by
the
assembly 90. The different valve stem feeding stations 92 sort different
configurations
of valve stems. A nut runner 98 is attached to the assembly 90 to insert nuts
on valve
stems that require nuts. The nut runner 98 receives nuts from a nut feeding
station 100
through a conduit 102. The station 100 can be disposed along the conveyor 12.
[0022] Referring now to Figures 4 and 5, the assembly 90 includes a
locating device 104 and a stem inserting device 106. The locating device 104
includes a
pair of light emitters, such as light emitter 108, and a pair of light
receivers, such as light
receiver 110. The inserting device 106 includes a valve stem holding pin 112,
a support
plate 114, and a moving device 116 for moving the holding pin 112 and the
support plate
114 relative to one another.
[0023] The method for locating the valve stem aperture in the wheel is
shown schematically in Figures 7-10. In Figure 7, the embodiment of the
assembly 90a
includes a pair of light emitters 108a and 108b, as well as a pair of light
receivers 110a
and 1 10b. The assembly also includes a support plate 114a and a valve stem
holding pin
112a. The assembly 90a is moved around the wheel 14 in the direction 122. The
light
emitters 108a, 108b are disposed on an opposite side of a lip 120 of the wheel
14 with
respect to the light receivers 110a, 110b. The valve stem aperture 118 is
defined in the
lip 120. The assembly 90a is moved in the direction 122 and the light receiver
110a
receives light from the light emitter 108a through the valve stem aperture
118. The
assembly 90a moves in the direction 122 at a predetermined angular velocity
and is
slowed by the controller 28 in response to the communication between the light
emitter
108a and the light receiver 1 10a through the valve stem aperture 118.
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[0024] Referring now to Figure 8, the assembly 90a is stopped after
passing the valve stem aperture 118. Due to the delay between sensing the
light by the
first receiver 110a, signaling the controller 28, the assembly 90a typically
passes the
aperture 118 prior to stopping the robot 16. The assembly 90a is moved in the
direction
124 until the light receiver 110b receives light from the light emitter 108b
through the
valve stem aperture 118, shown in Figure 9. In response to the communication
between
the light receiver 110b and the light emitter 108b through the valve stem
aperture 118,
the assembly 90a is moved in the direction 122 until the valve stem holding
pin 112 is
aligned with the aperture 118 and the valve stem is then inserted, as shown in
Figure 10.
The assembly 90a moves much faster in the direction of avow 122 than in the
direction
of arrow 124 because more distance is typically traveled to first locate the
aperture 118.
Once the aperture 118 is located, the assembly moves at a slower rate in the
direction of
avow 124 to determine a more precise location of the aperture 118 prior to
aligning the
stem holding pin 112a with the aperture 118.
[0025] Referring now to Figures 4 and 5, the valve stem is inserted in the
valve stem aperture 118a defined in the lip 120a of the wheel 14 by engaging
the moving
device to move the valve stem holding pin 112 relative to the support plate
114. The
moving device 116 includes a plate 126 attached to the robotic apparatus 16.
The
moving device 116 also includes a cylinder 128 attached to the plate 126 and a
rod 130
extendable and retractable with respect to the cylinder 128. The valve stem
holding pin
112 is fixedly associated with the end of the rod 130 and the support plate
114 is
rotatably associated with the cylinder 128. After the valve stem aperture 118
has been
located the robotic apparatus moves the support plate 114 to engage the lip
120a of the
wheel 14. The rod 130 is retracted in the cylinder 128, moving the valve stem
holding
pin 112 through the aperture 118a. The rod 130 is extended to remove the valve
stem
holding pin 112 from the aperture 118a, leaving the valve stem in the valve
stem
aperture 118a.
[0026] Referring now to Figures 3 and 4, after the valve stem has been
inserted in the valve stem aperture 118a, the second positioning mechanism 44
moves
the wheel with the inserted valve stem along the conveyor 12 past the
retracted pin stops
90-92. The wheel 14 now continues along the conveyor 12 for further processing
operations.
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[0027] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. The invention may be
practiced
otherwise than as specifically described within the scope of the appended
claims. These
antecedent recitations should be interpreted to cover any combination in which
the
incentive novelty exercises its utility. In addition, the reference nuanerals
in the claims
are merely for convenience and are not to be read in any way as limiting.
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