Method and apparatus for fabricating honeycomb insulating material

A method and apparatus for producing one or more individual stacks of superimposed, secured together, expandable tubular strips forming an expandable honeycomb panel. The strips coated with adhesive are advanced sequentially to the inlet of a stacking chamber having an elevated floor with a longitudinally extending slot of a length to receive each strip and which is narrower than the width of the strips to be delivered thereto. The strip so delivered is pushed up through the narrower slot and against the strip just previously delivered to the chamber, to adhere it to the latter strip. The chamber has a weight bar to exert a downward force on the stack of strips to provide good adherence between the strips.

FIELD OF THE INVENTION 
The present invention has its most important application in the mass 
production of individual stacks of secured together, flat, flexible 
expandable tubular strips from which expandable honeycomb panels of a 
desired overall width and expandable length can be cut by fabricators. The 
fabricators then assemble the pleated panels with various hardware, like 
support rails and pull cords, to form the completed assembly which is 
installed in the user's homes to cover windows and other openings. 
The present invention deals with a method and apparatus for receiving a 
continuous web forming a continuous, expandable flat tube, and by a unique 
combination of cutting, adhesive-applying and stacking operations 
efficiently produces said stacks of secured together flat tubular strips. 
BACKGROUND OF INVENTION 
Various methods and apparatus have been heretofore developed for making 
expandable honeycomb insulation panels. Most, if not all, of these methods 
leave much to be desired from the standpoint of production efficiency. 
Dutch Application Serial No. 6706563 of Landa, published Nov. 11, 1968 
discloses the formation of such a panel from a number of narrow webs of 
thermoplastic material each of which are unwound from a roll in an 
unfolded state. The longitudinal edges of each web are tightly folded 
over, an end strip of a given length is then severed from each web, and 
the severed strips are then simultaneously superimposed. The superimposed 
strips are then welded together to form an expandable honeycomb panel. 
U.S. Pat. No. 3,493,450 to Judge, Jr. discloses a method of making 
expandable honeycomb panels by applying lateral bands of adhesive to a web 
of sheet material and cutting individual strips from the web. A vacuum 
pick-up device picks up the severed and adhesive coated strips of material 
and sequentially delivers the individual strips above a stacking station 
where they are stacked one upon the other. In the process of being 
stacked, the adhesive adheres the adjacent strips together to form an 
expandable honeycomb panel structure. The completed honeycomb structure is 
then cut into narrow strips of a desired width to form expandable 
honeycomb panels. 
U.S. Pat. No. 4,450,027 to Colson discloses another method and apparatus 
for making expandable honeycomb insulation panels. Like the method 
disclosed in the Judge, Jr. Patent, the Colson method starts with a 
continuous web of unfolded material and, like the method disclosed in the 
Landa published application, progressively folds over the opposite 
longitudinal edges of the web. The Colson method then applies a continuous 
band of adhesive to one side of the web. The adhesive-coated continuous 
web, unlike the method disclosed in the Landa and Judge, Jr. prior art, is 
continuously wound on a rotating stacker. The wound web is removed from 
the stacker and cut into separate stacks of a desired length. 
The present method and apparatus to be described produces in a very 
efficient and reliable manner individual stacks of expandable honeycomb 
material, and without infringing known patents of others. 
SUMMARY OF THE INVENTION 
The present invention preferably starts with a single continuous web 
forming a continuous flat tube. While the flat tube could be formed in any 
manner for the purposes of the present invention, it is preferably formed 
from an unfolded web whose opposite longitudinal edges are folded over in 
the manner to be later described. An adhesive is applied to the web 
preferably in one or more continuous bands running longitudinally of the 
web. The adhesive coated web is then sequentially cut into strips, and 
then sequentially stacked in a uniquely designed stacking chamber and in a 
completely different manner than that carried out in all of the aforesaid 
described prior art methods. 
In the unique stacking system of the invention, a vertical stacking chamber 
is elevated above a strip delivery inlet point. The elevated bottom floor 
of this chamber has a longitudinally extending slot which is narrower than 
the width of the strips to be delivered thereto and of a length to receive 
each strip. Each strip, preferably coated with adhesive along the central 
region thereof, is delivered to this inlet point one at a time at spaced 
time intervals where each strip is pushed up through this slot and against 
the bottom face of the strip in the chamber above it to bond the strips 
together. The strip delivered into the stacking chamber preferably pushes 
against the strip above it, to a degree which raises all the strips above 
it to assure a good adhesive bond between all the strips. While the 
defining walls of the slot could be defined by a pair of spaced resilient 
strips which flex as the narrower more rigid yet flexible strips are 
pushed thereby, it is preferably defined by spaced rigid walls, so that 
each flexible strip bows upwardly as it is pushed through the slot. 
In accordance with another feature of the invention, the stacking chamber 
has an elongated weight-producing bar resting on the top of all the strips 
in the stacking chamber. The bar exerts a downward force upon the strips 
as they are stacked, so that the adhesive bands applied to the top faces 
of each strip will become even better secured together. 
The only prior art stacking systems known to the applicants which stack 
pieces of material from the bottom of the stack do so with pieces of rigid 
sheet material. When these rigid sheets are delivered to the inlet of the 
stacking chamber they engage a vertical abutment which aligns the pieces 
and makes it readily possible to stack successive pieces from the bottom 
of the stack. Examples of this prior art are the stacking systems shown in 
U.S. Pat. No. 3,866,765 to Stobb and U.S. Pat. No. 3,834,290 to Nelson. 
While in accordance with a broad aspect of the present invention the 
adhesive could be selectively applied to the tubular strips of the present 
invention after they are severed from a continuous web, it is most 
advantageously applied to the top of the web before the strips are cut 
therefrom. If separable stacks are to be formed in the stacking chamber, 
the adhesive could be applied to the web before it is cut into strips in a 
discontinuous pattern, where an adhesive applicator means is periodically 
momentarily shut off when widely spaced portions of the web passing the 
adhesive applicator means is to constitute the first strip in each secured 
together stack of strips to be formed in the stacking chamber. When the 
adhesive is applied to the strips after they have been severed from the 
web, the adhesive applicator means must be repeatedly turned on and off 
quickly, as the short strips pass thereby, so that adhesive will not drip 
in the gaps between the strips. This could severely limit the speed of the 
production line to prevent adhesive from falling into these gaps. In the 
preferred form of the invention, where one continuous stack of secured 
together strips is produced in the stacking chamber, there are no adhesive 
timing control problems to be concerned about. This is the preferred form 
because it was found that when a strip with no adhesive applied thereto is 
pushed into the stacking chamber, it can readily become wrinkled because 
it is not adhered along its length to the strip above it. This also can 
cause wrinkling in the strips below. For this reason also, there is placed 
below the weight-producing bar a rigid strip of cardboard or other 
material to which the uppermost strip in the stacking chamber adheres. 
This rigid cardboard strip can be readily pulled from this uppermost strip 
without tearing it after all the secured together strips are removed from 
the stacking chamber. 
In prior art sheet stacking systems involving products quite different from 
expandable honeycomb panels, where rigid sheets are to be adhesively 
secured together in separable stacks in a single stacking chamber, the 
sheets forming the first and last sheet in each stack were devoid of 
exposed adhesive. U.S. Pat. No. 4,500,301 to Nordstrom is an example of 
this prior art. However, there is no disclosure in this prior art of 
forming these sheets from a common web and selectively applying 
discontinuous or continuous bands of adhesive to the web before the pieces 
are cut from the web. 
For maximum production efficiency, it is preferred that the web be moved 
continuously past the adhesive applying and cutting stations. In such 
case, as a strip is cut from the web it must be separated from the next 
strip to be cut from the web and delivered to the stacking chamber where a 
pusher means has time to be raised and lowered to deliver the strip to the 
stacking chamber, before the next strip is delivered thereto. To this end, 
the conveyer system extending from the outlet of the cutting station to 
the inlet of the stacking chamber moves at a much higher speed than the 
conveying means which moves the web to the cutting station. 
The high speed conveyer advantageously comprises a pair of laterally spaced 
suction belts between which a raisable narrow bar is mounted to pass 
between the belts and into the slot in the bottom of the stacking chamber. 
As the bar moves up from a lowered position, it pushes the strip from the 
suction belts and delivers the strip into the stacking chamber as 
previously described. 
Other features of the invention are described and shown in the drawings 
which improve the efficiency and reliability of the method and apparatus 
aspects of the invention. These include a unique configuration of the 
stacking chamber which ensures the reliable stacking of the strips, and 
the use of sensors at various points in the system to monitor the 
operation of the fabricating equipment involved to achieve maximum 
production efficiency. For example, sensors are preferably provided which 
sense when the conveyor system reaches a desired speed, the presence of a 
spliced section of the web, the absence of an adhesive band, and the 
passage of the trailing edge of a strip cut from the web. Some of these 
sensors will stop the production line when these conditions are sensed. 
Others reset a counter controlling the time a strip is raised into the 
stacking chamber, or disable a strip raising operation so that a cut strip 
will not be stacked if it is the first strip cut from the web or one 
containing a splice.

DESCRIPTION OF PREFERRED EXEMPLARY FORM OF THE INVENTION 
FIGS. 1 and 2--The Product Made By The Present Invention 
FIG. 1 is a perspective view of a part of one of the stacks 3 of expandable 
honeycomb insulation material made by the method and apparatus of the 
present invention, where the expandable honeycomb material is of the form 
disclosed in Dutch application Ser. No. 6,508,988 of Landa, published Jan. 
13, 1967. As shown in FIG. 1 herein, the stack 3 is made up of individual 
folded strips 4 of flexible material each forming a flattened, expandable 
tube when secured to the next strip by bands 6--6' of adhesive. The strips 
as illustrated are preferably formed from an initially unfolded web whose 
opposite longitudinal edge portions are preferably folded over at 4c--4c' 
in any desired way into contiguous but spaced relation to form permanently 
tightly folded over panels 4b--4b' overlying a bottom panel 4a. The strips 
4 are cut from this web preferably after the bands 6--6' of adhesive are 
applied to the top portion of the web. The bands 6--6' of adhesive are 
applied only to the confronting end portions of the folded over panels 
4b--4b'. 
As previously indicated, the features of the present method and apparatus 
invention are applicable to tube-forming strips formed in ways other than 
by a folding process. Thus, for example, the panels 4b--4b' could 
constitute a single integral panel which is secured together to a separate 
panel of the same width at the opposite longitudinal margins of these 
panels. In either case, individual tube-forming strips are adhesively 
secured together and stacked in the unique manner previously described. 
FIG. 3--Basic Block Diagram of the Invention 
FIG. 3 illustrates in block form the basic method steps and apparatus 
elements used in the preferred form of manufacturing the stack 3 shown in 
FIGS. 1 and 2. A support structure is provided for preferably supporting 
two reels 12A--12A' of unfolded continuous, flexible web material of any 
desired construction, color and ornamentation used to form a honeycomb 
panel. These webs are respectively identified by reference numerals 13 and 
13'. Only one of the reels 12A or 12A' is unwound at any time and threaded 
through the apparatus to be described. When the web material on one of the 
reels has been used up, the leading edge of the web of material wound on 
the other reel is spliced to the end of the web by a suitable tape. 
As illustrated, the unfolded continuous web 13 or 13' of the roll 12A or 
12A' is fed to folding means 14. The folding apparatus 14 includes folding 
means to be described for effectively folding over the opposite lateral 
edges of the web 13 or 13' to form the flat tubular configuration of the 
folded strips 4 shown in FIGS. 1 and 2. The present disclosure illustrates 
unique folding apparatus which will be the subject of a divisional 
application. The folded web is then preferably fed first to adhesive 
applying means 16 and then to cutting means 18 which cuts individual, flat 
tube-forming strips from the web. 
As previously explained, the adhesive applying means applies adhesive bands 
6--6' to the spaced inner end portions of the folded over panels 4b--4b' 
preferably as a pair of continuous bands at the ends of the folded over 
portions of the web. The adhesive material is preferably an initially 
liquid thermosetting adhesive which sets partially in a relatively short 
period of time so that adjacent strips will be secured together to a 
sufficient degree when removed from the stacking chamber to be described, 
that they can withstand the rigors of subsequent handling. The adhesive 
sets completely over a long period of time to withstand the much greater 
pulling forces which are present when the panels cut from the stack of 
strips produced by the invention are cut into honeycomb panels of a 
desired length assembled with support rails and pull cords installed over 
windows and expanded and contracted many thousands of times by the owner's 
thereof in the useful life of the panels. Many such adhesives have been 
used in the prior art. One suitable adhesive is made by H. B. Fuller 
Company of 1200 Wolters Boulevard, Vadnais Heights, Minn. 55110. This 
material is a polyurethane resin adhesive. 
The various feed and guide rollers shown in other figures of the drawing to 
be described forming a part of the folding apparatus 14, adhesive applying 
means 16 and cutting means 18 constitute conveyor means described in some 
of the claims as a first conveyor section. They deliver the individual 
strips to a higher speed conveyor means 20 referred to in some of the 
claims as a second conveyor section. This second conveyor section operates 
at as much as twice the speed the peripheral speed of the feed rollers 
associated with the first conveyor section, so that the strips 4 cut from 
the folded web are conveyed to the inlet station of a vertical stacking 
chamber 22 at spaced time intervals. This permits a strip delivered to the 
inlet station of the stacking chamber to be stacked in the vertical 
stacking chamber 22 by a lifting means 24, sometimes also referred to as 
pusher means, which moves from an initial lowered position to a raised 
position and then back to a lowered position before the next strip is 
delivered to the inlet station. 
As described previously, the bottom of the vertical stacking chamber 22 is 
defined by a pair of laterally-spaced support shoulders which forms a 
strip pass-through slot in the floor of the stacking chamber. The lifting 
means 24 may include an elongated bar shown in FIG. 10A raisable through 
the slot at the instant of time the strip becomes aligned with the slot 
and the strip or strips in the stacking chamber, to push the strip into 
the chamber preferably to an extent to raise the stack of strips above it. 
In so doing, the adhesive bands 6--6', which have not yet completely 
dried, are pressed against the bottom panel 4a of the strip above it, to 
adhere the two adjacent strips together. To aid in the securement of 
adjacent strips together, a downward force is also applied to the top of 
the stack involved. As previously indicated, in one form of the invention, 
this is produced by a weight-forming bar shown in FIG. 10A. This weight 
could also be obtained by the weight of the various strips in the stacking 
chamber above the bottom strip being moved into the stacking chamber. 
A specific aspect of the invention deals with the manner in which the 
operation of the cutting conveyor and lifting means in FIG. 3 are 
controlled. This unique control means is identified in FIG. 3 as a block 
labelled condition-responsive control means 25 which includes software, 
the operation of which is shown in the functional block diagram of FIG. 
11. 
Preferred Apparatus for Splicing, Folding and Applying Adhesive to the Webs 
Referring now to FIGS. 4 and 5, the reels 12A--12A of web material 12A and 
12A' are fixed to rotatable shafts 28--28'. The shafts 28--28' extend from 
any suitable variable friction brake mechanism 29--29'. Such mechanism 
including the potentiometer and other material mechanism associated 
therewith can be purchased from Electroid Company, 45 Fadem Road, 
Springfield, N.J. 07081 under the purchase order designation Electroid 
TC-1 Tension Controller. These brake mechanisms produce a variable 
restraining force on the rotation of the reel support shafts 28--28' under 
control of suitable control signals from variable potentiometers 
responsive to the position of a dance arm, forming part of a web tension 
control mechanism to be described. This produces a fixed web tension in a 
manner well known in the prior art. 
The operator initially can select the reel 12 or 12A'. Extending from 
projecting arms 31--31' on a support frame 26 are rotatably supported 
reel-positioning saddles 27--27'. When the saddles are moved to their 
horizontal position, they enclose the opposite sides of the associated 
reels 12A--12A' to precisely position these reels on the shafts 28--28'. 
Microswitches R05--R05' are respectively depressed when the associated 
saddles are in their horizontal positions capturing the reels 12A--12A'. 
The saddles 27--27' are moved to this horizontal position only when the 
associated reels are to be unwound and fed to the equipment to be 
described. 
Supported adjacent to a side of the respective reels 12A--12A' are combined 
light source and light detecting sensor units R09 and R09' which 
respectively direct beams against the sides of the reels involved. When 
the web on the associated reel is completely unwound, light reflection 
ceases and the light sensor involved will indicate that the web involved 
has been completely unwound from the reel. When this occurs, the drive 
motor which operates the conveyor system which conveys the web through the 
equipment to be described ceases operation, to enable a splicing operation 
to be carried out with the web unwound from the other still unused reel. 
When the upper reel 12A is selected, and the associated saddle 27 is moved 
to its horizontal operative position, the web material is then threaded 
beneath guide roller 32 and above guide roller 34 to incline upwardly to 
the left, as shown in FIG. 4. A combined light source and light sensor 
unit R08 directing light downwardly against the inclined web between the 
rollers 32 and 34 will be reflected away from the sensor part of the unit 
R08 when the web inclines upwardly to the left as viewed in FIG. 4. 
If the lower reel 12A is selected, the web unwinding from the reel will 
extend under the roller 32 and over the roller 34, thus causing a path of 
light which strikes the sensor portion of the unit R08. 
The web leaving the guide rollers 32-34 rides over the upper surface of a 
splicing table 39 which has a vertical slit 39' in the top surface thereof 
which extends for the width of the table. A pair of clamping bars 36-38 
carrying magnets 36'-38' therein (FIG. 4A) are respectively mounted for 
pivotal movement along with housings 36a-38a in a vertical plane extending 
transverse to the length of the web passing over the table 39. The 
housings pivot on axes 36b-38b whereas the bars 36-38 pivot on axes 
36c-38c. When one of the bars 36 or 38 is pulled into a horizontal 
position, an associated magnet presses and clamps the web against the top 
surface of the table 39. 
When one of the sensor units R09 or R09' mounted adjacent the reel 12A or 
12A' having its saddle 30 or 30' in a horizontal position senses the 
complete unwinding of web material from the associated active reel, the 
movement of the web through the drive motor feeding the web is stopped. 
The bars 36-38 and their housings are rotated into their horizontal 
clamping positions. A sharp knife edge is pressed through the web into the 
table slit 39' to cleanly sever the web. The rear clamping bar 36 is then 
pivoted out of its clamping position and the resulting severed end section 
of the web is discarded. The web from the unused reel is then passed 
around the idler rollers 32-34 and the moved opposite the slit 39', where 
it is in abutment with the end of the web ahead of it. The clamping bar 36 
is then returned to its clamping position and then splicing tape is then 
placed over the abetted webs to secure them together. The conveyor system 
for moving the web is then rendered operative by operating a start switch 
on control panel 44 (FIG. 5). The strip cut from the web containing the 
splice is automatically not stacked in a manner to be described to avoid 
producing a defective honeycomb panel. 
Referring to FIG. 4A, when the clamping arm housings 36a and 38a are 
rotated into a horizontal position, the front faces of these housings will 
depress respective microswitches S03 and S03'. If either of these 
microswitches are depressed, the drive motor 64 will be stopped. 
There is preferably located beyond the table 39 a splice thickness detector 
means S02 (shown diagrammatically only in FIG. 4) and a splice color 
detector means S02' (also shown diagrammatically only in FIG. 4). The 
splicing tape used by the operator to splice the end of the web from one 
of the reels 12A or 12A' to the other, is a very thin splicing tape which 
can readily pass through the equipment including a slot in a web guide 
plate to be described which folds the web. However, the web wound on the 
reels 12A and 12A' frequently has splicing tape securing together sections 
of the web which tape has a thickness which would not go through this 
slot. When such a thick splicing tape is detected, the web feeding drive 
motor is stopped and this tape is replaced by a thin splicing tape. The 
start mode of the equipment is then initiated which will result in the 
strip containing the splice being ejected without being stacked in the 
stacking chamber. 
If the splicing tape used by the fabricator of the web reels secures 
together different sections of the web on the reel is thin enough to pass 
through this folding slot, the fabricator is requested to make that tape a 
given color like red. When a red color is detected on the web by the 
splice tape color detecting means S02', the equipment being described 
operates in a mode where the strip cut from the web containing the red 
splicing tape is not stacked in the stacking chamber to avoid producing a 
defective honeycomb panel. 
The web extends from the splicing table 39 and passes over an idler roller 
40 then down and around the bottom of an idler roller 41 forming part of a 
tension control system re best shown in FIG. 4A. It includes a dancer 
pivotably mounted arm 43a carrying the idler roller 41 and beneath which 
the web passes to exert an upward force on the dancer arm 43a. A downward 
pull is exerted on the dancer arm by a pneumatic unit 43b having a piston 
rod 43c secured to the arm. The movement of the dancer arm controls the 
operation of a potentiometer 43d forming part of the controller purchased 
from the Electroid Company which generates a signal fed to the brake 
control mechanism exerting an adjustable opposition force to the rotation 
of the reel shafts 28--28'. The tension control unit operates to keep the 
dancer arm 43a horizontal. The pull down force of the pneumatic unit 43b 
is initially adjusted to exert a given predetermined force. For example, 
in the presence invention where the exemplary strip material is material 
No. 5040 manufactured by the Asahi Company (a strip 0.006" thick and 
having a density of 40 grams per square centimeter), a seven pound tension 
force is applied to the dancer arm 43a. If the upward pull force on the 
dancer arm 43a exceed this seven pound force, the dancer arm will move up 
and a signal will be fed back to the friction brake mechanism on the 
selected reel shaft which will reduce the friction force on the shaft. 
This reduces the tension on the web so as to keep the dancer arm 43a in a 
horizontal position. 
If the web extending around the idler roller should break and not be 
present for any other reason, the dancer arm 43a will obviously drop. A 
suitable light sensor R10 will sense this condition and generate a signal 
which will stop operation of the web feed motor. 
The web leaving the tension roller 41 passes over the top of an idler 
roller 42, then down around the bottom of a pair of idler rollers 37 and 
37' and then over the top of an idler roller 44, where it then passes 
through a folding unit 47 best shown in FIGS. 4E and 4F. The folding unit 
47 includes a slotted guide plate having formed therein a uniquely curved 
web pass-through slot generally indicated by reference numeral 49. This 
slot has a partially collapsed U-shape. It thus includes a generally 
horizontally extending bottom portion 49a which terminates in reversely 
curved portions 49b--49b' which respectively join upwardly angled and 
oppositely curved upper portions 49c--49c'. As best shown in FIG. 4E, the 
overall length of the slot generally corresponds to the width of the web 
to be folded. In such case, as the web passes through the slot, the 
opposite longitudinal edge portions 13a--13a' thereof are folded upwardly. 
Since the web is pulled forwardly by a drive roller to be described, it 
passes reversely around an idler roller 45 in its folded state to contact 
a heat drum 48. 
The surface of the drum 48 may be heated by electrical heating wires 
through which current flows in a controlled manner, to set the temperature 
of the surface of the drum to a desired value. In the exemplary invention 
being described, the drum has a fifteen inch diameter and web extends 
around approximately 340-350 degrees of the drum circumference. The drum 
surface temperature is set to approximately 350 degrees Fahrenheit and the 
web is moved around the drum surface at a speed of 250 feet per minute. 
The web upon leaving the drum bends around a driven roller 45' supported 
on a pneumatic unit 55A as shown in FIG. 4G. 
The folded over web is pressed against the drum by adjustable pressure 
rollers 46 spaced around the drum. These pressure rollers are carried on 
the ends of pneumatic units 46A. A similar pneumatic unit 55A is shown in 
FIG. 4G. It carries a roller 55 pressing against the web leaving the drum 
against the driven roller 45' previously referred to. The pneumatic units 
can be operated to selectively withdraw the rollers carried thereby from 
the drum or the rollers 55 from the driven roller 45' or to press the 
roller carried thereby with a set pressure against the web passing beneath 
the roller when the exemplary Asahi material previously described is 
utilized, this pressure is preferably 40 pounds. 
When the pusher bar 131 has a projection thereon which, in the upper 
position of the bar, operates what is sometimes referred to as a pusher up 
microswitch S05 to indicate that the bar is in its upper most position. 
This projection will operate what is sometimes referred to as a pusher 
down microswitch S02 to indicate that the bar 131 is in its lower most 
position. The control system of the apparatus will de-energize the drive 
motor 64 if the projection on the bar 131 does not operate the pusher down 
microswitch S02 shortly after the pusher up microswitch S05 is operated or 
the pusher up microswitch is not operated when a signal is generated 
requiring operation of the stacker apparatus. 
When the pressure rollers are withdrawn from the drum, a suitable sensor 
(not shown) will identify that fact. 
The web leaving the pressure and driven rollers 45' and 55 pass over a 
slightly raised cambered cooling table 58 whose surface is cooled to a 
given desired temperature as by cooling coils passing beneath the table 
surface. In the exemplary form of the invention being described, the 
temperature of the surface of the cooling table was 20 degrees Fahrenheit. 
The cooling table was 18" long when the web was pulled over the cooling 
table so it maintained contact with the table over its 18" length. The 
table has 11/2" recesses like 58' (see FIG. 4D) equally spaced from the 
peak center line of the table. The tips of a pair of glue applicator heads 
60--60 discharging beads of adhesive on webs press the web slightly into 
these recesses to enable the most effective application of adhesive to the 
web. 
The temperature of the glue and the dispensing thereof are controlled in a 
well known manner. The entire glue applicator system including the glue 
applicator heads and the temperature controls therefor is a commercial 
unit sold by Nordson Corporation of 6755 Jimmy Carter Boulevard, Norcross, 
Ga. 30071 under the model designation PUR204. The desired glue 
temperature, of course, depends upon the particular adhesive which is 
used. As previously indicated, the preferred adhesive is obtained from the 
H.B. Fuller Company under order No. NP 2028. For this adhesive, the 
desired glue temperature is 120 degrees C. 
The glue applicator heads 60--60' are mounted on a common frame 62 for 
movement from a normally inoperative raised position to a lowered position 
where they press the web into the recesses 58'--58'. The adhesive 
applicator heads apply adhesive over the outer end portions of the web so 
as to produce the adhesive bands 6--6' previously described in connection 
with the description of the completed product shown in FIGS. 1 and 2. 
To avoid waste of material, should the glue applicators fail to disperse 
glue on the web, a glue gap sensor S08 is provided just beyond the 
adhesive applicator heads 60--60. The sensor S08 preferably includes a 
sensing probe extending to a heat responsive device which generates a 
control signal when the probe fails to sense a heated source, namely the 
adhesive. This control signal stops the web drive motor. 
Cutting Apparatus 
The web leaving the cooling table is fed to the cutting apparatus 18. Refer 
now to FIGS. 5A-5C which shows this apparatus in its most preferred form. 
It includes a bottom roller 70 which is driven at a slightly higher (for 
example a 10% higher) peripheral speed than the driven roller 45' 
supported above the heating drum 48. Supported for rotation above the 
driver roller 70 is a cutting wheel 74 which carries a knife blade 76 with 
a rounded edge. When the knife blade 76 is rotated opposite the driven 
roller 70, it just barely wipes on the surface thereof. A web fed between 
the cutter wheel 74 and the driven roller 70 will bite through the web 
material cleanly if it rotates at a much higher peripheral speed than the 
web passing by it. For example, the peripheral speed of the cutting wheel 
is about twice the peripheral speed of the driven roller 45, such as 500 
feet per minute. The cutter wheel 74 is secured to a shaft 75 which in 
turn connects to the output shaft of a clutch 77. This clutch is 
preferably one sold by the Warner Electric Corporation of Pitman, N.J. The 
input shaft 79 to this Warner clutch may be continuously driven by a 
separate motor or, as illustrated, by gears 81 and 83, in turn, driven by 
a belt 85 which also drives the shaft on which the driven roller 70 is 
mounted. When the clutch 77 receives an input signal, it rotates it output 
shaft 360 degrees and then locks the output shaft in place. 
Timing Control 
The timing of the operation of various parts of the equipment now being 
described, such as the cutter and stacking operations, is effected through 
timing pulses generated by a pulse encoder C05 (FIG. 5) coupled to the 
shaft of the web feeding driven motor identified in the drawings by 
reference numeral 64. The pulses generated by this encoder are fed to 
various counters to be described. For example, as the web leaves the 
cooling table 58 it is fed to web cutting apparatus 18. The cutting 
apparatus is controlled by what is referred to as a cut counter means 61 
shown in FIG. 11 to be described in more detail. When the web feeding 
drive motor comes up to speed, a drive motor speed sensing means 62 also 
shown in FIG. 11 resets the cut counter to zero and permits the feeding of 
pulses from the encoder C05, identified in FIG. 11 as a drive motor pulse 
generating means to the cut counter means. 
The drive motor 64 is coupled in any suitable way, such as by drive belts 
and the like, to drives the various elements which feed the web through 
the cutting apparatus, and subsequently through a high speed conveyor 
system to the stacking apparatus to be described hereafter in detail. 
High Speed Conveyor System and Stacking Apparatus 
Refer now to FIGS. 6-9 which illustrate an exemplary high speed conveyor 
system driven from the web feeding drive motor 64. The drive motor 64 
through belts imparts rotation to a common drive shaft 109 in turn coupled 
to driven pulleys 92--92' around which extends endless apertured conveyor 
suction belts 94--94. The upper sections of these conveyor belts 94--94 
have their longitudinal edge portions riding on support surfaces 96--96' 
and 98 (FIG. 6A). The central portions of the belts 94--94' have suction 
apertures communicating with a horizontal extending suction chamber 100. 
The chamber communicates vertically at spaced points therealong through 
vertical passageways 102 communicating with a main suction entry tube 104. 
The tube 104 extends to a source of suction through an inlet conduit 105 
(FIG. 6). The suction applied through the belt apertures retains the strip 
cut by the cutting apparatus and discharged upon the inlet end of the 
conveyor belts 94--94' shown in FIGS. 6-7. The conveyor belts 94--94' are 
fed at approximately twice the speed that the web 13 or 13' is fed up 
through the cutting apparatus 18, such as 500 feet per minute. 
The belts 94--94' are laterally spaced apart a distance to define a pusher 
bar pass-through slot 106 (FIG. 7). The conveyor belts 94--94' extend 
horizontally beneath the stacking chamber 22 as shown in FIGS. 8 and 9. As 
best shown in FIG. 8, the lower section of the conveyor belts 94--94' are 
guided by guide rollers 110, 112, 114 shown in FIG. 8 and guide rollers 
116 and 118 shown in FIG. 6. 
As shown in FIGS. 6-9, the stacking chamber 22 overlies about one-half the 
extent of the high speed conveyor belt system thereshown. Refer more 
particularly to FIGS. 10, 10A and 10B which show vertical sectional views 
through the stacking chamber 22. 
The stacking chamber construction illustrated evolved from a number of 
previous much less reliable stacking chamber designs. Thus, the bottommost 
portion of the stacking chamber 22 is desirably defined between the 
confronting spaced vertical surfaces of a pair of metal bars 130--130' 
anchored in place by screws 131--131'. These bars, for example, when 
stacking the 11/8" width strip referred to, preferably have a height of 
about 1.00" and a spacing of 1.135". This leaves a total clearance space 
of only 0.010". The stacking chamber above the blocks 130--130' is defined 
between a pair of glass panels 120--120' secured by double sided adhesive 
tape respectively to a pair of aluminum bars 132--132'. In a manner to be 
described, the spacing of the glass panels 120--120' preferably diverge 
upwardly from their spacing at the bottom thereof of 1.135" matching the 
spacing between the bars 130--130'. The height of the exemplary panels 
being described is about 12". The spacing of the panels 120--120' at the 
top thereof is preferably 1.250". 
The assembly of its glass panels 120--120', and their associated aluminum 
bars 132--132' are supported at the inner faces from the vertical legs of 
pairs of angle members 138--138' spaced along the stacking chamber by 
bottom pairs of screws 140--140' and upper pairs of screws 142--142'. 
These screws pass freely through openings in the vertical legs of the 
angle members 138--138' and thread into threaded apertures formed only in 
the aluminum bars 132--132'. The threaded shanks of the screws 140--140' 
and 142--142' receive threaded locking nuts 141--141' and 143--143' 
bearing on the outer faces of the angle member legs. The rotation of the 
nuts adjusts the horizontal position of the assembly of each glass panel 
and aluminum bar at the point of connection of the associated screws and 
the aluminum bars. In this manner, the desirable spacing between the 
bottom and top portions of the glass panels are easily adjusted. 
The stacking chamber 22 may, for example, be slightly over 12 feet in 
length as are the strips which are stacked in the chamber. Before the 
chamber is stacked with any strips, it contains an elongated rectangular 
weight bar 122 extending the full length of this chamber. The bar 
preferably weighs 8 pounds in the case where the particular 11/8" strips 
described are being stacked. Beneath the bar is a narrower cardboard strip 
124. The bottom of the stacking chamber has a floor 126 in which is formed 
a longitudinal pass-through slot 128 extending the full length of the 
stacking chamber. The upper section of the conveyor belts 94--94' are 
located slightly below the slot 128. The slot 128 in the floor of the 
stacking chamber may have a width, for example, of 0.420". 
When a strip to be stacked is delivered by conveyor belts 94--94' in 
alignment with the slot 128 in the floor of the stacking chamber, it is 
pushed into the stacking chamber through the slot by a pusher member 
illustrated in FIGS. 10 and 10A as a vertical, rectangular bar 130. As 
best shown in FIG. 10, this pusher bar 131 is attached to a number of 
horizontally spaced rack-forming plates 132 mounted opposite various 
points below the stacking chamber 22, and suitably guided for vertical 
movement as by guide pins 132'. Each rack-forming plate 132 has rack teeth 
132' which are engaged by the teeth of a pinon gear 134. The various pinon 
gears 134 are rotatably supported on a common shaft 135. The shaft 135 is 
attached to the end of an arm 136 in turn pivotally secured to a link 138 
connected to the piston rod 140 of a pneumatic unit S04. All of the 
pneumatic units are controlled by valves in turn controlled by solenoids 
137 shown in FIG. 4. The solenoids are electrically controlled by the 
electrical control system of the invention shown in FIG. 11. The pneumatic 
fluid under pressure is kept in a master pneumatic drum 137 shown by 
pneumatic lines of the valve portions of the solenoids 135. 
When the solenoid controlling the pneumatic unit S04 receives a stack 
control signal, a piston 140 thereof becomes extended to rotate shaft 135 
and cause each pinon gear 134 to rotate in a counterclockwise direction, 
as viewed in FIG. 10. As each rack plate 132 moves upward, it carries the 
pusher bar 131 attached to it upward. The pusher bar 131 is narrower than 
the space between the conveyor belts 94--94' and the width of the slot 128 
in the bottom of the stacking chamber. When fully raised, the pusher bar 
131 thus pushes the flexible strip of material off of the belts and 
through the slot 128 in the floor of the stacking chamber 22. The bar 
rises a distance above the chamber floor so as to push the strip involved 
against the adjacent strip in the stacking chamber and raises all the 
strips, for example, 0.750" above the chamber floor. The weight bar 122 
applies a downward force as the pusher bar 131 applies an upward force, to 
compress the various strips together. FIG. 10A shows the pusher bar in its 
fully raised position and FIG. 10B shows the pusher bar in its fully 
lowered position. 
As previously indicated, the adhesive bands applied to the top of each of 
these strips are only partially dried and thus are sufficiently tacky to 
secure the strips together without separation or movement relative to one 
another during subsequent handling of the stacked material. The purpose 
for tapering the stacking chamber above the spaced rectangular metal bars 
130--130' defining the bottom of the stacking chamber is to avoid the 
jamming of the strips in the stacking chamber in their elevated positions. 
The outwardly diverging confronting surfaces of the glass panels 120--120' 
assure that upon lowering of the pusher bar the stacked strips will follow 
the pusher bar down, until all the stack of strips rest upon the floor of 
the stacking chamber, as shown in FIG. 10B. 
As the uppermost strip in the stacking chamber is pressed against the 
aforementioned cardboard strip 125, the adhesive on the top face thereof 
evenly bonds the strip thereto. This cardboard strip 125 can readily be 
pulled from the uppermost strip in the stack without tearing the same 
after the stacked strips are removed from the stacking chamber 22. The 
cardboard strip 125 helps to maintain the horizontal profile of the upper 
strip and, indirectly, all of the strips below, to avoid a waviness in the 
outline of the stack of secured together strips in the stacking chamber. 
The timing of the operation of the pneumatic unit S04 is determined by the 
instant the trailing edge of the strip advanced by the conveyor belts 
94--94' passes by what is referred to as a trailing edge sensor means S06 
shown in FIGS. 6 and 7 at a point slightly behind the rear edge of the 
stacking chamber. This sensor can be a combination light source and sensor 
unit directing its light beam downwardly in alignment with the spacing 
between the conveyor belts 94--94'. When this sensor senses the transition 
between the reflection and non-reflection of light on the conveyor belts, 
a control signal is generated. Except when the movement of the pusher bar 
131 is disabled under circumstances to be explained, the generation of 
this transition control signal will cause the push bar elevating pneumatic 
unit S04 to be operated after a predetermined amount of movement is 
imparted to the strip following this transition point, so that all the 
strips pushed into the stacking chamber are in substantial longitudinal 
alignment. The transverse alignment of these strips is determined by the 
adherence of each strip to the one above it in the stacking chamber. 
There is also provided a leading edge sensor S07 positioned at the inlet 
end of the high speed conveyor system, as shown in FIGS. 6 and 7. This 
leading edge sensor senses the presence or absence of a leading or 
trailing edge of a strip being fed from the cutter. In case the strip is 
not fed from the cutter apparatus, there will be an absence of a 
transition from a light non-reflection to a light reflection state for a 
given minimum period of time indicating the absence of a further strip 
emanating from the cutting apparatus. If desired, the control portion of 
the invention can stop the drive motor if this occurs. Of more importance 
is to stop the drive motor if the cutting wheel fails occasionally to cut 
through the web. A counter set and reset by the passage respectively of 
the leading and trailing edges of a strip by sensor S07 so the drive motor 
64 is stripped when the count exceeds a given count indicating a cut 
failure. 
Signals generated by the various sensors described may be fed to a 
programmable logic controller (PLC) which may be of conventional 
construction. This controller, together with many manual switches and 
indicator lights, would be contained in the cabinetry generally indicated 
by reference numeral 141 in FIG. 4. This programmable logic controller 
can, for example, be a controller manufactured by Toshiba Corporation 
under the order designation EX Series. 
Logic Block Diagram of FIG. 11 
FIG. 11 is a functional block diagram showing in the various blocks thereof 
sensors, counters, and control means responsive thereto to control the 
operation of a web feeding drive motor relay 158, cutter solenoid C06, 
pusher bar solenoid S04 and an alarm relay control means 160. The count 
and control functions could be performed by hardware or software. When a 
start switch on control panel 44 (FIG. 5) is initially operated, this 
effects automatic resetting of all of the counters and initiates a start 
mode of operation of the equipment. In the start mode, the first strip cut 
from the web must not end up in the stacker since it will not have the 
proper band of adhesive applied thereto. Also, the start mode should not 
be effective to energize the drive motor through its drive motor relay 158 
unless various sensors indicate that the system is in proper operating 
order. To this end, a drive motor control means 156 has a stop signal 
input which, when receiving a stop signal, prevents energization of the 
drive motor relay 158 to prevent energization of the drive motor 64. As 
shown, the stop signal input line to the drive motor control means 156 
extends to various sensors some not shown in the drawings and some shown 
in the drawings. These sensors generate a stop signal preventing the 
energization of or de-energizing the drive motor 64. Such a stop signal 
will be generated when various sensors indicate the absence of glue on the 
web (sensor S08); inadequate glue temperature; inadequate glue level; 
positions of reel saddle arms 29--29' indicating that both red saddle arms 
are not properly positioned (sensors R05--R05'); inadequate air pressure; 
raised position of pressure rollers; empty web reels (sensors R09--R09'); 
stop button pushed; no trailing edge sensed by sensor S01; overly thick 
splice sensed by sensor S02, etc. If all elements of the system are in a 
"go" condition, then the functions now to be described will be carried 
out. 
A drive motor pulse generator C05 also referred to as a pulse encoder means 
develops pulses at its output at a rate in proportion to the speed of the 
shaft of the drive motor 64, as previously explained. These pulses are fed 
to the input of the driver motor speed sensing means 62. The sensing means 
62, when the motor comes up to speed, open a gate 163 to feed pulses from 
the drive motor pulse generator means to the count input of a cut counter 
means 61. At the same time, the drive motor speed sensing means 62 will 
reset the cut counter means 61 to zero count by feeding a reset signal 
thereat. The cut counter means 61 generates a cut signal when the web 
being fed to the folding, adhesive-applying and cutting means moves 
slightly more than 12 feet, which is the length of the strips which is to 
be severed from the web by the cutter apparatus. When the stacked strips 
are removed from the stacking chamber, the strips are cut down precisely 
to a 12 foot length. When the cut counter means 61 reaches a count 
indicating the feeding of the web such a distance, the counter is 
automatically self-reset as indicated by the feedback loop line 63 and a 
cut signal is fed to cutting apparatus control means 152 which, in turn, 
operates the cutter motor solenoid C06 to initiate the cycle of operation 
of the cutting apparatus previously described. 
When the equipment initially starts to operate, the reset input of a first 
cut responsive means 162 is in a condition indicating that a first cut has 
not yet occurred. When the trailing edge of the first strip cut by the 
cutting apparatus passes by the trailing edge sensing means S06 feeds a 
set signal to the set input 106 of the first cut responsive means 
indicating that the first strip has been cut and fed by the high speed 
conveyor belts 94--94' to the input of the stacking chamber. However, the 
output of the first cut responsive means is fed to a disable input 149b of 
a stacker pusher bar control means 149 which will prevent the pusher bar 
from being raised into a position to push the strip into the stacking 
chamber. Conveyor belts 94--94' will then move the strip involved off the 
discharge end of these conveyor belts. Any subsequent pulses fed from the 
trailing edge sensing means S06 by the first cut responsive means 162 will 
not be responded to. This could be achieved in any suitable way as, for 
example, by the software program programmed to generate a disable input 
signal only for the first pulse thereby from the trailing edge sensing 
means S06. The first cut responsive means 162 is in effect a pulse counter 
which carries out the desired disable function only on the first pulse it 
receives from the trailing edge sensing means S01. The output of the 
trailing edge sensing means S06 is also fed to a pulse counter 165 which 
will feed a disable pulse to the disable input 153b of a strip stacker 
counter means 153 (sometimes also called a stack level counter) only upon 
generation of the first signal by the trailing edge sensing means S06. The 
signals generated by the trailing edge sensing means S06 are also fed to 
the count input 153a of the strip stacker counter means 153. After the 
first disabled trailing edge signal pulse is generated the next signal 
generated thereby will be counted by the strip stacker counter means. When 
the count of the counter means 153 equals the desired number of strips to 
be stacked in the stacking chamber 22, this counter generates a stop 
signal fed to the stop signal input of the drive motor control means 156 
to terminate energization of the drive motor. The stack of strips in the 
stacking chamber can then be manually or automatically removed therefrom. 
Each time the trailing edge of a strip passes by the trailing edge sensing 
means S06, the control signal generated thereby is also fed to an input of 
trailing edge signal absence sensing means 168 and to the input 149a of 
stacker pusher bar control means 149. The trailing edge signal absence 
sensing means 168 generates a stop control signal when a given time 
interval passes after receiving a control signal from the trailing edge 
sensing means S01 indicating that strips are not being fed from the 
counter apparatus. 
When the stacker pusher bar control means 149 receives a signal at its 
input 149a from the trailing edge sensing means S06, it will energize the 
pusher bar solenoid S04 to initiate upward movement of the pusher bar. 
The signal generated by the pusher-up sensor S05 when the pusher bar is in 
its raised position is fed to one input 170a of an up-down signal absence 
sensing means 170. Similarly, the signal generated by the pusher-down 
sensor S07 when the pusher bar is returned to its lowered position is fed 
also to a second input 170b of the up-down absence sensing means 170. If 
the sensing means 170 does not receive within a given time interval both 
signals from the pusher up and the pusher-down sensors S05 and S02, it 
will generate a stop signal fed to the stop signal input 154 of the drive 
motor control means 156 since such a situation indicates some failure in 
the stacking process. 
When leading edge sensing means S07 generates a control signal as the 
leading edge of a strip leaving the cutter passes thereby, this control 
signal is fed to the input 166a of a leading edge signal absence sensing 
means 166 which generate a drive motor stop signal fed to the stop signal 
input 156a of the drive motor control means 156 if a given time interval 
passes after the receipt of this control signal indicating that the cutter 
is not delivering anymore strips to the conveyor belts 94--94'. It also 
preferably generates a stop signal if the time following the passage of a 
leading edge of a strip exceeds a given time interval before the trailing 
edge passes thereby. The sensing means in such case has a counter which is 
set and reset by the passage of the leading and trailing edges of a strip. 
When the splicing sensing means S02 senses the presence of a red splicing 
tape in the web unwinding from reel 12a or 12a', a signal is fed to the 
second disable input 149b of the stacker pusher bar control means 149. The 
operation of the pusher bar control will then be disabled, so that the 
strip containing the splice will not be pushed into the stacking chamber. 
Rather, it will be discharged at the end of the conveyor belts 94--94'. 
When the stop signal input 156a receives a stop signal, it is also fed to 
an alarm relay control means which energizes an alarm light and sounds an 
audible alarm. 
Software Program Control 
FIG. 11 shows a functional block diagram to illustrate control of the 
equipment of the invention. This section describes such control in 
software program flow chart terms. 
Counters 
All counters (such as those shown in FIG. 11) obtain their inputs from an 
optical encoder pulse count (referred to previously as drive motor pulse 
generator means C05) which is coupled to the programmable logic controller 
(PLC). Since the encoder C05 is directly connected to the drive motor 
shaft any movement of the drive motor is counted by counters of the PLC. 
Resolution of each encoder pulse is approximately equivalent to 0.006" 
travel of the web. 
1. Cut Counter 
a. Start button is pushed and drive motor 64 begins accelerating. 
b. Once programmed drive motor RPM has been reached, the cut counter is 
initialized to zero count. 
c. Wait for counter to accumulate sufficient pulses for programmed cell 
length (nominally equal to slightly more than 12 feet) and then energize 
cut solenoid. 
d. The cut counter is reset to zero count. 
e. Steps "c" and "d" are repeated until a stop condition occurs after which 
the routine starts with step "a". 
2. Stacking and Cell Height Counters 
a. When power is initially applied to the machine, all counters are set to 
zero. 
b. Start button is pushed. 
c. Wait for first web cut. 
d. Optical proximity switch S06 near stacker changes state and signals the 
PLC when trailing edge of cut fabric passes under it. PLC ignores signal 
and fabric is ejected from end of stacker. This first piece of fabric does 
not have glue applied to entire length since glue nozzles wait until 
programmed drive motor RPM has been reached before applying glue. 
e. Wait for fabric cut. 
f. Wait for optical proximity switch S06 to sense trailing edge. 
g. Set cell height counter to zero. 
h. After programmed count following operation of trailing edge sensor 
switch S06, energize pusher bar solenoid. 
i. Increment Cell Height Counter (referred to also as strip stacker counter 
means). 
j. If Cell Height Counter is less than programmed cell height (nominally 
600 cells) then repeat steps "e" through "i". 
k. Stop drive motor and reset height counter to zero. Return to step "b". 
3. Gap Sense Counter 
Strip cuts may not be correct. Optical proximity switch S07 located 
approximately 18 inches downstream of the cutting station is used to set 
and reset this counter as the trailing and leading edges of the strip from 
each cut pass under it. 
a. Wait for strip cut. 
b. Set gap sense counter to zero. 
c. Check counter. If in excess of programmed counts, then trailing edge of 
strip is not detected in time by proximity switch S07 and the web was not 
cut at proper time. Stop Drive Motor so operator can repair. Return to 
step "a" otherwise continue to step "d". 
d. Trailing edge reset counter to zero. 
e. Check counter. If in excess of programmed counts, then leading edge of 
fabric was not detected by proximity switch S07. Stop Drive Motor so 
operator can repair otherwise continue with step "a". 
4. Splice Detection--Butt end with tape and woven overlap 
Factory splices are applied to strip within a reel so that a complete reel 
can be formed. The strip is butt-spliced with colored tape, nominally 
bright red. Special optical proximity sensor S02 optimized to sense 
colored tape are located downstream of the strip reel so that the 
following sequence is successful. 
Another type of splice found in the reels are two ends of fabric woven 
together with an overlap of material. This leaves a noticeable "bump" at 
the splice. Mechanical switch S02' moved in a vertical direction senses 
the bump. It is also located downstream of the strip reel so that the 
following sequence is successful. 
a. Wait until proximity switch S02' senses spliced tape. 
b. Complete next web cut. 
c. Complete another web cut. 
d. Wait for cell to stack (from step "b" cut). 
e. As trailing edge of next strip with splice tape on it passes stack 
proximity switch S06, inhibit stacking and eject strip out end of the 
conveyor belts 94--94'. 
5. High/Low Reel Selection 
There are two web reels on each machine namely, upper and lower reels 12A 
and 12A'. When web is threaded between two roller wheels located 
downstream of the reels, an optical proximity switch R08 between the 
rollers determine which reel is supplying web. 
The web from the upper reel 12A rolls tightly underneath the leading roller 
32 and over the following roller 34 allowing light from the proximity 
switch to reflect off web. Web from lower reel 12A' does not make contact 
with the leading roller due to a different supply angle and the proximity 
switch sees only free space. 
The PLC therefore determines which reel has web being used and switches the 
brake control to the appropriate reel. The brake control is used in 
conjunction with the tension detector described to control the unspooling 
tension of a reel. The reel not selected is allowed to free turn. 
FIG. 12 shows the various input and output signals respectively fed to and 
from the PLC. 
Scope of Claims 
While the invention has been described with reference to a preferred 
embodiment, it will be understood by those skilled in the art that various 
changes may be made and equivalents may be substituted for elements 
thereof without departing from the broader aspects of the invention. Also, 
it is intended that broad claims not specifying details of a particular 
embodiment disclosed herein as the best mode contemplated for carrying out 
the invention should not be limited to such details.