Note: Descriptions are shown in the official language in which they were submitted.
22
Description
Control System for an E_ astomer
Extrusion and Applicator Apparatus
Technical ~ield
This invention relates to apparatus for
extruding elastomeric material and applying the same to
an article, and more particularly, to control system
for such an apparatus.
Background Art
Prior art of possible relevance includes the
following United States Letters Patent: 3,251,722
issued May 17, 1966 to Holman; 3,268,380 issued August
23, 1966 to Guichon; and 3,975,126 issued August 17,
1976 to Wireman et al.
Many articles formed in part of elastomeric
materials are built-up by laying up an elastomeric
ribbon on some sort of an article core. This technique
is frequently employed in tire manufacture or retread-
ing operations as, for example, in building up thesidewall and/or crown portion of a pneumatic tire car-
cass which may be new or used.
The process of manufacturing other elastomeric
articles such as bladders, tire sidewall protectors, or
the like, may also employ a ribbon lay-up process.
In any event, in many instances, it is desired
to provide relatively close control over the final
exterior dimensions of the article being formed for any
of a variety of reasons. In the case of tires, the
final size of the tire is obviously important since the
same will be matched with other tires which must be of
like size and shape. In addition, if more rubber
ribbon is laid up on the tire carcass than is necessary
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to achieve the desired final size, it may become
necessary to trim away excess rubber before placing the
tire in a mold for final curing. Close control of the
application operation can avoid or minimize the need
for such trimming. And, of course, when trimming is
required, some wastage of material may result thereby
contributing to the material expense in fabricating the
article.
In the usual case, the rubber ribbon used in
the lay-up process is ~ormed by an extruder and then
passed to calender rolls which will provide the ribbon
with a constant cross section. If the ribbon received
from the calendar rolls was received at a uniform rate,
the application of the ribbon to an article to be
formed moving in a predetermined path in a uni~orm
manner could be accomplished simply by moving the
article in its path at a uniform rate of speed matched
to the rate of extrusion. However, as is well known,
it is extremely difficult, if not impossible, to obtain
accurate control over the rate of output of an extruder
thereby making it impossible to achieve application of
the ribbon to an article, in a closely controlled
fashion, by moving the article uniformly in its path.
Moreover, in many instances, it is highly
desirable to continuously provide a uniform degree of
stretch to the ribbon after it has been extruded and
prior to its application to the article to achieve
accurate dimension control of the strip at the time it
is being applied to the article. Consequently, many
systems have been proposed and commercially exploited
wherein some sort of means are employed to vary the
rate of application of the ribbon to the article pro-
portionally to the rate of extrusion or forming of the
ribbon to account for the variations attendant the
extruding operation.
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The above-identified patents and publication
exemplify approaches oE this type.
However successful these approaches may be in
some applications, they nonetheless fail to provide the
extremely accurate stretch control necessary to achiev-
ing extremely accurate dimension control of the rubber
strip at the precise point of application to the
article.
The problem is further compounded where the
ribbon applicator's position with respect to the arti-
cle is varied during the forming process about several
axes. Since the extruder will normally be at a fixed
position and the position of the applicator will vary
with respect thereto, the length of the ribbon and its
stretch between the extruder and the applicator will
typically vary as the applicator is moved with respect
to the extruder. This, of course, will vary the degree
of stretch of the ribbon between the two which in turn
will alter the cross section dimension of the ribbon.
Consequently, product uniformity may suffer and/or it
is necessary to lay up more rubber on the article than
is necessary and trim the excess to insure that an ade-
quate amount of rubber is applied to the article in the
first instance.
And, of course, the variations attendant the
operation of such systems make it extremely difficult
to achieve full automation of the process without the
need of frequent monitoring. Consequently, the expense
of labor to practice such processes is increased by
reason of the need for an observer.
Disclosure of Invention
In one aspect of the present invention there
is provided an elastomeric ribbon extrusion and appli-
cator apparatus including an extruder for generating an
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elastomeric ribbon, an applicator roller for applyingthe elastomeric ribbon to an article at a point between
the roller and the article, and control means for con-
trolling at least one of the rate of extrusion and the
rate of application in response to a signal generated
during operation of the apparatus, the improvement
wherein said signal is generated by a resolver having a
rotary input shaft, a sleeve housing and mounting said
resolver, said roller being journaled on said sleeve,
and a reduction gear train interconnecting said shaft
and said roller.
Other objects and advantages of the invention
will become apparent from the followirlg description and
claims.
Brief Description of Drawings
Fig. 1 is a schematic, side elevation of an
apparatus for extruding and applying a ribbon to an
article and controlled by a control system;
Fig. 2 is a schematic view of a cable system
utilized in a conveyor so as to allow variation of the
path of the ribbon while maintaining that path of fixed
length;
Fig. 3 is a perspective schematic of the
mechanical structure;
Fig. 4 is a sectional view illustrating an
applicator rGller and rate sensing device; and
Fig. 5 is a block diagram of a control circuit
for the apparatus.
Best Mode for Carrying Out the Invention
The subject control system provides a highly
accurate dimensional control over an elastomeric strip
applied to an article is exercised to the point that a
high degree of automation can be achieved. It is
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intende~ that a number of the components of the system
be computer controlled in the sense of providing a
desired sequence of events. In general, the principal
computer control to be exercised over the ribbon appli-
cator which applies the ribbon to the article at vary-
ing locations thereon. Since this desired sequence of
events will be dependent upon the size and shape as
well as the nature of the article, it can be readily
appreciated that the precise sequencing as it relates
to actual application is not a material part o~ the
present invention, but will be determined by the nature
of the article to which the strip is applied. With
this in mind, an embodiment of the invention will be
described in detail.
A typical system includes an extruder or cal-
ender roll 10 which generates a ribbon 12 of elasto-
meric material, usually rubber, having a desired cross
sectional shape. ~he ribbon 12 is ultimately conveyed
to an article 14 for application thereto by an applica-
tor, generally designated 16. As illustrated in Fig.
1, the article 14 is a tire carcass and the applicator
16 will apply the ribbon to any desired point on the
tire 14. During such application, the tire 14 is moved
in a predetermined path by an article drive system 18.
In the usual case, the path in which the tire 14 is
moved will be a rotary path with the tire 14 being
rotated about its intended axis of revolution.
In general, the applicator 16 will include a
conventional applicator roller 20 over which the ribbon
passes to be pressed against the tire 14 at a desired
location. The applicator 16 will also include a plur-
ality of stitcher rolls 22 (only one of which is shown)
which are employed for the usual purpose. It will be
observed that the stitcher rolls 22 are downstream from
the applicator roller 20 in the direction of ribbon
movement.
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As alluded to previously the applicator 16 is
utilized to apply the ribbon to almost any point on the
tire 14 as, for example, the crown 24 and the sidewalls
26. To a limited extent the applicator 16 may apply
the ribbon 12 to the interior of the tire 14 although
such application will frequently be limited by the
geometry of the applicator 16 and of the tire 14,
interference between the two being the limiting factor,
if any.
For purposes to be seen, the applicator 16
includes a brake 28 by which the applicator roll 20 may
be restrained.
In operation, the tire 14, after the applica-
tor 16, and specifically, the applicator roll 20 has
brought the ribbon 12 into contact with the tire 14,
will be driven at a controlled rate in its path by the
article drive 18 so as to draw the ribbon 12 over the
applicator roll 20. When the desired buildup of rubber
has been achieved, the ribbon 12 may be automatically
severed simply by braking the applicator roll 20 with
the brake 28 and thereafter continuing rotation of the
tire 14 for a short amount to stretch the ribbon 12
between the stitcher rolls 22 and the applicator roll
20 to the point of breakage. This will allow a short
length of the ribbon 12 to extend past the applicator
roll 20 toward the stitcher roll 22 to enable easy
start-up of the next application cycle simply by bring-
ing the applicator roll 20 into contact with the tire
14.
To achieve the previously described ability to
apply the ribbon 12 to the tire at a variety of loca-
tions, the applicator 16 is provided with the capabil-
ity for movement about three axes. A first axis about
which control is exerted is an axis of movement of the
applicator 16 towards and away from the path in which
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the article is moved. The second axis of movement of
the applicator 16 will be generally transverse to the
first axis (either straight line, or along a shallow
arc) so as to enable selection o~ the particular loca-
tion on the tire 14 whereat the ribbon is to beapplied. The third axis of control is generally a
rotational axis provided such that the applicator roll
20 will generally be facing the tire 14 at some desired
angle as, for example, a right angle. Accordingly,
various movable mounts for the applicator 16 may be
provided to allow movement of the same about the
aforementioned three axes as well as controlled drives
for correctly positioning the applicator 16 on each
such axis. The means by which such mounting of the
applicator 16 and of the control of the same in terms
of its position on any of the three axes will be
described in considerable detail hereinafter. For pre-
sent purposes it is sufficient to say that a suitable
drive such as that shown schematically at 30 for the
applicator 16 about all three axes is provided and the
drive 30 may receive its instructions from, for
example, a computer 32 or a tape (not shown) suitably
programmed to direct the desired sequence of applica-
tion of the ribbon 12 to the particular article 14
involved.
According to the present embodiment, a ribbon
moving means, generally designated 34, is interposed
between the extruder 10 and the applicator 16. As
illustrated, the ribbon moving means 34 is in the form
of a conveyor, but it is to be understood that other
devices might be used in lieu thereof. For example, it
is not unusual to employ ribbon temperature control
drums about which the ribbon 12 is wound between the
extruder 10 and the applicator 16 in systems of this
general type.
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In an~ event, the ribbon moving means 3~ may
have a pure conveying function or it may combine a con-
veying function with some other ribbon treating ~unc-
tion.
As illustrated in Fig. 1, the ribbon moving
means 34 is a pure conveyor application and includes a
belt 36 trained about rollers 38 and ~0 journaled on a
frame 42. The upper run 44 of the belt 36 receives the
ribbon 12 from guide rollers 46 and conveys the same to
a guide roller 48 which in turn directs the ribbon to
the applicator 16. In this connection, it will be
noted that the conveyor frame 42 mounts a support 50
which in turn mounts the applicator 16. The conveyor
frame 42 is mounted on rollers 52 and is movable
towards and away from the path of movement o~ the
article 14 under control of the three axis drive 30 to
provide for positioning of the applicator 16 on the
first mentioned axis. Additionally, by means to be
described, the upper portion of the conveyor frame 42
is pivoted about generally vertical axes so as to be
movable about such axes to position the applicator 16
about the second axis mentioned previously under
control of the three axis drive 30. Control of the
applicator 16 over the third axis mentioned above is
preferably attained by movement of the applicator roll
20 and stitching rollers 22 by the applicator 16 itself.
The guide rollers 46 receive the ribbon 12
from guide rollers 54 mounted on a ~ovable take-up
carriage 56. The ribbon 12 is supplied to the guide
rollers 54 by one or more guide rollers 58 which in
turn receive the ribbon from a roller 60 which receives
the ribbon 12 from the extruder and/or calender rolls
10 .
It will be appreciated that the precise path
taken by the ribbon 12 from the extruder 10 to the
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applicator 16, and specifically, the applicator roll
20, will vary as the position of the applicator 16
moves with respect to that of the extruder 10. And, as
alluded to previously, it is necessary to maintain
strict stretch control to achieve accurate ~imension
control of the ribbon 12. Consequently, if nothing
more were done, the relative movement between the
extruder 10 and the applicator 16 would result in
periodic increasing and decreasing of the length of the
path followed by the ribbon 12 with the consequence
that the length of the ribbon 12 within that path would
be subjected to greater or lesser amoUnts o~ stretching
precluding accurate dimension control~ Therefore,
means are employed whereby, even though the path taken
by the ribbon 12 varies, the path length is fixed.
Referring to Fig. 2, the take-up carriage 56
is shown schematically and mounts first and second
sheaves 70 and 72. A cable 74 is fixed via a stiff
spring 76 to a fixed abutment 78 to the right of the
take-up carriage 56 as viewed in Fig. 1 and is first
trained about the sheave 70 and then about a sheave 80
also journaled to the abutment 78. From the sheave 80,
the cable 74 passes to a sheave 82 journaled on a fixed
abutment 84 to the left of both the conveyor and the
25 take-up carriage 56, as viewed in Fig. 1. The cable 74
is taken from the sheave 82 and fixed to the movable
carriage frame 42 of the conveyor as schematically
illustrated in Fig. 2 and then trained about the sheave
72. From the sheave 72, the cable 74 is fixedly
secured to the abutment 84.
As a consequence of this construction, when
the position of the ribbon moving means 34 is shifted
along the first axis, for each increment of such move-
ment by the conveyor frame 42, the take-up carriage 56
will move half an increment of such movement. The
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manner in which the length of the path taken by the
ribbon 12 is fixed will becorne apparent from -the
following example. If it be supposed that the conveyor
frame 42 is moved to the right as viewed in Fig. 1 a
distance of two inches, the take-up carriage 56 will
move but a single inch. The length of ribbon between
the guide roll 58 and the lower roller 54 on the take-
up carriage 56 will increase by one inch. At the same
time, the length of ribbon between the upper roller 54
on the carriage 56 and the roller 46 mounted on the
carriage frame 42 will decrease by one inch, an equal,
offsetting amount. All other parts of the ribbon path
are fixed as will be apparent from the geometry illus-
trated in Fig. 1. So the overall length of the path
remains the same even though the location of the path
will vary.
As mentioned previously, the applicator 16 is
movable about three axes to provide maximum system
flexibility. In particular, such a range o~ applicator
movement allows application of the strip not only to
the crown of a tire as in prior art systems, but to the
sidewalls as well. Control of the position of the
applicator 16 about those three axes can be controlled
through conventional numerical control systems as will
be explained.
Mechanically, the means by which three axes
movement is achieved without altering the length of the
path that the ribbon travels from the extruder 10 to
the applicator 16 are shown in Fig. 3. An underlying
surface supporting the system is shown at 100 and
mounts, for example, a pair of spaced rails 102 which
extend toward the article drive system 18 (shown in
Fig. 1). Mounted for movement on the rails 102 is a
carriage 104 and a drive system 106 which may be of
conventional construction and of the type used in
z
numerical control apparatus for moving the carriage 104
along the rails 102, bidirectonally, in the direction
of an arrow 108. This may be designated the provision
for providing movement about the so-called "Y" axis.
The upper surface of the carriage 104 mounts,
for example, a pair of rails 110 which are at right
angles to the rails 102. A second carriage 112 is
mounted for movement on the rails 110, bidirectionally,
in the direction of an arrow 114. A drive unit 116,
termed an "X" drive unit, is provided for shifting the
carriage 112 as mentioned and is mounted on the car-
riage 104.
The applicator 16 is mounted for rotation
about a vertical axis (z) defined by a shaft 118 jour-
naled on the carriage 112. A drive system 120 is pro-
vided for rotating the applicator 16 about the afore-
mentioned axis, bidirectionally, in the direction of an
arrow 122. The drive unit 120 is carried by the car-
riage 112.
As a result of the foregoing, it will be seen
that the Y-drive unit 106 moves the applicator 16
toward and away from the article path while the X-drive
unit 116 moves the applicator 16 along an axis trans-
verse to the Y axis, that is, across the article path.
The drive unit 120 drives the applicator such that the
axis of rotation of the applicator roll 20 is parallel
to the surface of the article to which the ribbon is
applied, whether it be the original surface of the
article 14 prior to ribbon application or the modified
surface thereof as modified by the application of one
or more layers of ribbon.
Through appropriate programming a conventional
numerical control may be used to provide positive
inputs to the X and Y-drive units 116,106, respect
ively, in a conventional fashion. In a numerical con-
trol unit, the Z axis control is utilized to provide an
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input to the drive unit 120. Those skilled in the art
will recognize that rotary positioning is not typically
controlled by the Z axis control in a numerical control
but is done in the present invention for the purpose of
insuring that the applicator roll 20 will move to the
commanded coordinates in a coordinated fashion typical
of the mode of control over those three axes provided
by a conventional numerical control.
In order to achieve this interrelationship as
far as the drive unit 120 is concerned, a mechanical
provision must be made since the Z axis control in a
numerical control provides information for linear move~
ment rather than pivotal movement. This is easily
attended to through suitable mechanical gearing between
the drive unit 120 and the applicator head 16 such
that, for example, one revolution of the drive motor in
the drive unit 120 will cause rotation of the appli-
cator 16 a predetermined number of degrees as, for
example, one degree. In this way, a predetermined
linear command from the numerical control to the drive
unit 120 is translated mechanically into a predeter-
mined angular so as to achieve the desired relation of
the applicator roll 20 to the surface of the article 14.
Fig. 3 also illustrates the interrelationship
between the applicator 16, its three axis drive, and
the conveyor 34. Because considerable movement of the
applicator 16 relative to the extruder may occur, it is
necessary that the conveyor 34 follow the applicator to
properly convey the ribbon to the applicator 16. At
the same time, it is desired that the length of the
path of ribbon movement remain fixed as mentioned
previously.
To this end, the end of the conveyor 34 near-
est the applicator 16 is supported by a yoke 140 which
in turn is pivoted about a vertical axis by a shaft 142
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to a drawbar 144 connected to the carriage 112.
The end of the conveyor 34 remote from the
applicator 16 is likewise supported by a yoke 146 which
is pivoted about a vertical axis by shaft 148 which in
turn is connected to the conveyor frame 42, shown only
schematically in Fig. 3.
As a consequence of this construction, when
the Y-drive unit 106 shifts the applicator 16 in the
direction of the arrow :L08, the conveyor will roll on
the rollers 52 (Fig. 1). Conversely, when the carriage
112 is moved by the X-drive unit 116, not only will
some rolling on the rollers 52 occur, but there will
also be pivoting about the axes defined by the shafts
142,148.
In order to insure that pivoting of the con-
veyor in response to ~ axis movement does not change
the length of the ribbon path, it will be observed from
Fig. 1 that the uppermost roller 46 guides the ribbon
onto the conveyor in a vertical path while the roller
48 takes the ribbon off the conveyor in a vertical
path. ~he location of the shaft 148 is made coincident
with the vertical path between the uppermost roller 46
in the conveyor and is shown at A in Fig. 1. In a
similar vein, the axis of the shaft 142 is made to
coincide with the vertical path of the ribbon to the
roller 48 and is shown at B in Fig. 1. Finally, to
insure that pivoting of the applicator 16 in response
to operation of the unit 120 does not change the length
of the path, rollers 160,162 are provided to guide the
ribbon in a vertical path which coincides with the axis
of rotation provided by the shaft 118 mounting the
applicator 16. This axis is designated C in Fig. 1.
Turning now to Fig. 4, a significant mechani-
cal component of the system will be described.
Specifically, there is shown the applicator roller 20
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in greater detail. The same includes a slightly
barrel-shaped outer surface 170 which may be of con-
ventional configuration and which is journaled by
bearinys 172 on a sleeve 174. The sleeve 174 is, in
turn, secured to the applicator 16 in any desired
fashion. Within the sleeve 174 is an electrical
resolver 176 having a rotary input shaft 178. The
input shaft 178 mounts a carrier 180 which in turn
journals one or more planet gears 182 for rotation
about axes displaced frc~m the axis of rotation of the
input shaft 178. The end of the sleeve 174 from which
the shaft 178 extends mounts a fixed ring gear 184
which is coaxial with the shaft 178 and which engages
the planet gears 182.
The corresponding end of the applicator roll
20 is closed by a cap 186 secured in place by a set-
screw 188. An inwardly directed collar 190 on the cap
186 terminates in a sun gear 192 which is coaxial with
the shaft 178 and which is meshed with the planet gears
182. As a consequence, a reduction gear train is pro-
vided whereby the rotation of the applicator roller 20
is conveyed to the input shaft 178 of the resolver 176
at a reduced rate as, for example, a four or five-to-
one reduction. The resolver 176 provides output
signals which are utilized in a control system to
achieve accurate stretch control of the ribbon from the
extruder to the point of application by the applicator
roller 20 to achieve accurate dimensional control.
This stretching occurs between the extruder 10 and the
applicator roller 20. In the present invention, a
first amount of stretch is supplied by driving the belt
36 at a higher linear rate than the rate of extrusion
of the ribbon 12 from the extruder. A second stretch
can be obtained by moving the article 14 in its path
such that the surface to which the ribbon is being
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applied is moved at a greater rate than the rate of
movement of the upper run of the belt 36 thereby
drawing the ribbon off the applicator roller 20 at that
higher rate. Extremely accurate control over this
stre~ching is provided by reason of the fixed length of
the ribbon path to the applicator roller 20 as well as
by providing control over the rate of movement of the
ribbon by the ribbon moving means 34 and the rate at
which the ribbon is drawn over the applicator roller 20
by controlling the rate of movement of the article in
its path. The means by which such control is exercised
are illustrated in Fig. 5.
Specifically, there is provided an encoder 200
of conventional construction which provides a cyclic
electrical wave output proportional to the rate of
revolution of its input shaft. The encoder 200 is
suitably mechanically coupled to the roller 60 (Fig. l)
receiving the ribbon 12 from the extruder lO. As a
consequence the encoder 200 provides a pulsing output
signal representative of the rate of ribbon extrusion
by the extruder lO. Stated another way, the signal is
representative of the rate of receipt of the ribbon 12
by the roller 60. Those skilled in the art will recog-
~ nize that the signal is basically a position signal as
opposed to velocity signal which is highly preferred
for use in the servo system to be described since
velocity servo systems are significantly more difficult
to control than position servo systems.
The output of the encoder 200 is provided to a
conventional divider circuit 202 which is operative to
reduce the number of cycles per unit of time rec,eived
from the encoder 200 to some lesser number. A manual
input 204 is employed to control the divider 202 to
provide the desired proportioning which will determine
the degree of stretch provided between the extruder and
the conveyor.
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A drive motor 206 is used to drive the ribbon
moving means 34 and is coupled to an encoder 208 which
in turn provides a cyclic electrical output representa-
tive of the rate at which the upper run 36 of the rib-
bon moving means is being driven, again a positionsignal rather than a velocity signal. This signal ls
provided on a line 210 to the divider circuit 202 as a
feedback signal which is then compared with the propor-
tioned signal from the encoder 200 to issue a command
signal on a line 212 which is in turn provided to the
drive motor 206 and its speed control circuit.
As a consequence, the ribbon moving means 34
will drive the ribbon at a linear rate faster than it
is being extruded from the extruder to provide stretch
between the two points. Should the extrusion rate drop
off, the command signal on the line 212 will cause the
drive motor 206 to slow down. Should the extrusion
rate increase, there will be a corresponding propor-
tioned increase in the drive rate from the drive motor
20 206.
The proportioned signal from the divider 202
which is representative, in a proportioned fashion, of
the rate of extrusion, is fed on a line 214 to a second
divider 216 which may be similar or identical to the
divider 202 and which likewise reduces the number of
cycles in the signal received to some lesser number per
unit of time in accordance with a control input pro-
vided by a manually operable selection device 218. The
proportion selected cor.brols the degree of stretch
between the article moving means 34 and the applicator
roller 20.
A command signal for controlling the rate at
which the article is driven in its path by the article
drive 18 is issued to cause the same to increase,
decrease, or not modify the rate of article movement
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proportionate to the rate of extrusion from the
extruder 10. As shown in Fig. 5, the article drive 18
drives the article 14 which/ in turn, tends to drive
the applicator roller 20 by drawing the ribbon off -the
same. The resolver 176 within the applicator roller
provides a feedback signal on a line 220 to the divider
216 which is indicative of the rate of application of
the ribbon to the article 14. Again, the signal on the
line 220 is a position feedback signal and not a
velocity signal. Consequently, the article drive 18
drives the article 14 at a variable rate of speed which
is proportional to the rate of extrusion of the ribbon
by the extruder 10.
It should be understood that the particular
use of the applicator roller 20 in generating the feed-
back signal for control purposes is highly advantageous
since it automatically compensates for variations in
the geometry of the article 14 which could not be
sensed if the feedback was taken from a direct mechani-
cal coupling of a sensor to the article drive 18. Forexample, when considering the application of the ribbon
to the sidewall of a tire, it will be recognized that
the linear velocity at which the ribbon 12 is being
applied to the sidewall of the tire for a given rate of
rotation of the tire will vary depending upon whether
the point of application is relatively radially inner-
most or relatively radially outermost. Feedback from
the article drive is incapable of detecting this
difference. Conversely, feedback from the applicator
roller 20 will automatically sense a greater rate of
linear movement of application as a radially outer
position of application is approached by movement of
the applicator 16 under the influence of the three axis
drive. Thus, extremely accurate stretch control, and
thus, dimensional control of the ribbon being applied
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is achieved through use of the present invention
enabling wholly automatic operation of the system
through appropriate programming oE the three axis drive
30 by a computer such as the compute~ 32 which, of
course, will be dependent upon the article being
processed and the desired application of ribbon thereto.
It should be observed that the use of a
resolver such as the resolver 176 in connec~ion with
the applicator roll 20 is highly desired. Because o~
the small size of resol~ers such as the resolver 176 as
opposed to encoders such as the encoders 200,208, the
same may be readily incorporated within the applicator
16 without undul~ increasing its size which would limit
flexibility of the system by reason of potentional
interference between the article 14, supporting compon-
ents thereof, and parts of the applicator 16.
Finally, while the control system of the
invention has been illustrated and described as so-
called "hardware", the invention specifically contem-
plates the use of an appropriately programmed computer,such as a microprocessor, in lieu of such hardware com-
ponents as the divider units 2~2,216 and portions or
all of the manual inputs 204,218 and other like means.
Industrial Applicability
The above-described control system for an
extrusion and application apparatus for applying an
elastomeric ribbon to an article is ideally suited for
use in production environments where low labor require-
ments are highly desirable. The system providesexcellent dimensional control over the ribbon,
compensating for all the variables in the application
process upstream of the applicator itself so that
excellent dimension control of the ribbon can be
obtained thereby further lending to system use and
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automatic operation. Because of the excellent control
achieved through use of the system, it is no longer
necessary to apply an excess of ribbon to an article to
insure that the article will obtain its desired
external configuration. Consequently, material costs
are lowered and the need for subsequent operations,
such as trimming, is avoided.
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