Note: Descriptions are shown in the official language in which they were submitted.
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This invention is directed principally, but not exclusively, to
collators for assembling a plurality of paper webs and carbon or transfer
webs into continuous business forms.
As applied to collating machines, one of the disadvantages of
present systems, where a continuous sheet or form is being transferred from
a feed roll to another roll, is the necessity for constant adjustments to
compensate for web tension or roll speed. Furthermore, in any system which
can only feed stock by pulling, whether the stock be paper, polythene, or
any other material, it is impossible to run at zero tension. As will be
appreciated, the force required to pull stock from a large roll varies from
that which is required with a small roll. This analogy also applies to
braking and stopping large and small rolls.
Individual rolls may also vary from one another in size, density
and strength, and again in prior systems it is generally left to the
operator to make the various individual adjustments.
Consequently there is a need for a drive system which would en-
able an operator to pre-set a tension for each roll of stock, and preferably
not have to make any further adjustments, other than when the rolls require
changing, for tension, braking or speed, unless different tensions are
required to compensate for problems such as short or long sheet length, or
different types of stock e.g. polythene. With such a system, even if ad-
justment of tension was required, it would be preferable if no additional
adjustments were required for brak;ng or speed.
As indicated above, prior systems which can only feed stock by
pulling, render it impossible to run at zero tension, however, with the
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present invention to be described, rolls are driven through the core, thus
making it possible to adjust toward zero tension.
The primary object of the disclosed invention is to provide a
means for driving a roll of stock which will supply upon demand a continu-
ous sheet, at an automatic~ constantly adjusted speed, and at a pre-set
tension.
An additional object of the disclosed invention is to provide a
means for sensing speed changess or tension changes, of the materials and to
adjust the s~eed of the drive roll.
Yet a further object of the disclosed invention is to provide a
spring loaded counterweighted displaceable dancer rod for sensing the speed
changes of the materials.
Still another object of the disclosed invention is to provide a
large diameter gear mounted to the dancer rod and in contact with a small
diameter gear connected to a potentiometer for adjusting the speed of the
motor.
Yet another object of the disclosed invention is to provide a
dancer rod which has a displaceable counte~eight so that the dancer as-
sembly may be balanced. This aids sensing of only the web and spring
tension (and excludes the weight of the dancer assembly).
Yet another object of the disclosed invention is to provide a
compact displacement sensing means mounted some distance from the frame for
sensing the displacement of the dancer rod and adjusting the motor speed
thereby.
Yet another object of the disclosed invention is to provide a
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sensing means for sensing the changes in diameter of a roll of stock and
adjusting the speed of the roll drive motor accordingly.
These and other objects and advantages of the invention will be
readily apparent in view of the following description and drawings of the
above described invention.
The above and other objects and advantages and novel features of
the present invention will become apparent From the following detailed
description of the preferred embodiment of the invention illustrated in the
accompanying drawings, wherein:
Figure 1 is a front elevational view of a converter showing a
feed roll of, for example polyethylene, a feed roll of, for example paper,
and a take-up roll for the joined materials;
Figure 2 is a rear elevational view of the mechanism of Figure
1 showing the motor drive means driving the rolls and the tension sensing
means;
Figure 3 is a fragmentary perspective view of the dancer rod
shwoing its spring loading and counterweighting;
Figure 4 is an expanded view of the tension sensing and adjust-
ing mechanism of Figure 2;
Figure 5 i5 a fragmentary perspective view of the motor and worm
gear reducer for driving the rolls,
Figure 6 is an elementary block diagram of the control circuit;
Figure 7 is a fragmentary cross-sectional view of the dancer rod
and sensing mechanism mounted on the frame,
Figure 8 is a different embodiment of Figure 1;
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Figure 9 is a plan view of a roll d-iameter sensing device Form-
ing part of the invention;
Figure 10 is a sectional elevation of the device according to
Figure 9.
Referring now to Figure 1, a frame F for mounting the necessary
rolls and mechanisms is shown. The frame F has a -front side and a rear side
the front side being shown in Figure 1.
A polyethylene feed roll 10 having a continuous strip of poly-
ethylene 12 is shown mounted on the front side of frame F. A paper feed
roll 14 for holding a continuous strip of paper 16 is shown opposite poly-
ethylene feed roll 10. Operating means for joining, or otherwise performing
work on the polyethylene strip 12 and the paper strip 16 are shown at 18. A
take-up roll 20 for winding the joined polyethylene 10 and paper 16 is
shown, however, the subject invention is not limited to such a specific
take-up system.
Although for the purpose of this description a polyethylene feed
roll 10 and a paper feed roll 14 are disclosed, it should be evident that in
practice a collator can utilize many rolls and a variety of materials.
A dancer rod 22, as best shown in Figure 3, is provided For each
of the rolls 10 and 14 of Figure 1.
A d~ncer rod 22 is comprised generally of a pair of arms 24 and
26 connected by rod 28 and shaft 30. Rod 28 rotates on pins 32 which are
positioned and fastened at 34 through arms 24 and 26.
A collar 38, having bearings 39 and races 39A, is bolted to
Frame F by bolts 40. Shaft 30 extends through frame F and aperture H
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located in collar 38 and frame F. Shaft 30 connects arms 24 and 26 and is
maintained in position by key 42 mounted in key slot 44 of arm 26. Races
39A are maintained in position by retaining rings ~1 and 41A. Spacer ring
43 is concentrically mounted adjacent retaining ring 41A.
A counterweight 46 is displaceably mounted on shaft 48 mounted
in arm 24. The counterweight is displaceable over the length of shaft 48
for balancing the dancer assembly.
Spring 50 is connected to arm 24 and frame F for maintaining
positive tension on dancer rod 22. While a tension spring 50 is shown the
arrangement could satisfactorily utilize a torsion spring.
Referring again to Figure 1 it can be seen that polyethylene
strip 12 proceeds from polyethylene feed roll 10 to roller 52, around roller
52 to dancer rod 22 and to additional rollers 54 and 56. Paper strip 16 of
paper feed roll 14 advances from roller 58 to a second dancer rod 22 and
then to rollers 60 and 62.
Polyethylene strip 12 and paper strip 16 are joined by joining
means 18 and then advanced via roller 64, to be wound around driven take-up
roll 20.
Referring now to Figure 2, the rear side o-f frame F is shown.
The drive means D for driving the rolls 10 20 and 14 are best shown in
Figure 5.
A motor M is connected to worm gear drive W which is connected
to a bearing housing S which passes through frame F and is drivingly connec-
ted to the rolls 109 14 and 20. A direct current motor is disclosed9
although any other suitable adjustable speed motor is possible. The worm
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gear drive W may have a sufficiently steep gear ration to make it self
locking. Without input torque from the motor M the worm gear drive W
requires such high torque to turn that it is almost impossible for the
rolls lO, 14 and 20 to turn if the motors M are not providing input
torque to worm gear drive W. Worm gear drive W also aids in maintaining
a stable tension in the material feed and as indicated above, may be
provided with a self~locking feature whereby any time the motor power is
cut-off~ the roll drive has to stop. This can also be accomplished by
the use of dynamic braking on the motor itself.
The dancer rod displacement sensing means is best shown in Figure 4.
Collar 68 having bearings 69 and races 69A is mounted concentric with
shaft 30 and held in place by bolts 40 used for mounting collar 38 to
frame F. Races 69A are held in position by retaining rings 71 and 71A.
Shaft 30 passes through frame F and aperture H and sleeve C and connected
with toothed gear 70 mounted on collar 68. Gear 70 is connected to shaft
30 by cap screw 72 so that any displacement of dancer rod 22 will cause
shaft 30 to turn and thereby cause gear 70 to turn. Gear 70 has a number of
teeth 74 located about its circumference for meshing with teeth 76 of gear
78. Gear 78 is connected to gear-adjustable potentiometer 80 for adjusting
the output signal to motor M by means of wires 32 connecting potentiometer
80 to isolation amplification module 88. Potentiometer 80 is mounted on
bracket B affixed to frame F so that gear 78 will be capable of meshing with
the teeth of gear 70. As best seen in Figure 2? it can be seen that each
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roll 10, 14 and 20 has its own motor M and worm gear drive W or drive means
D. Likewise, each roll 10 and 14 has its own dancer rod 22 as well as dis-
placement sensing means A for continuously adjusting the speed of the
appropriate motor M.
The motor M may be connected to a reversing and logic module 84,
as best shown in Figure 6, which is connected to the output side of motor
controller 86. Motor controller 86 may be connected to isolation amplifica-
tion module 88 and proportioning feed back transducer or potentiometer 80.
In this way, the speed of motor M may be controlled by the potentiometer 80
of displacement sensing means A.
A roll 10 of polyethylene strip 12 and a roll 14 of paper 16 are
mounted in frame F. The polyethylene strip 12 and the paper strip 16 are
wound through the appropriate rollers and dancer rods until coming together
at operating or joining means 18. The ioined strip then exists from joining
means 18 and passes by the appropriate rollers and dancer rods to be wound
about take-up roll 20.
Due to the relative thickness differences of the polyethylene
strip 12 and the paper backing 16, the angular speed of rotation o-f rolls
10 and 14 changes as the diameter of the material 12 and 16 on the rolls 10
and 14 respectively, changes due to the polyethylene 10 and paper 16 being
driven from their respective rolls. Because the polyethylene 10 and the
paper 16 have different thichnesses their wound diameters diminish at dif-
ferent rates. Consequently, i-f their speeds of removal from the rolls are
to be as initially set, then the motors M driving the respective rolls 10
and 14 must be adjusted independently of each other. To facilitate this
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adjustment, reference is made to Figures 9 and 10 which show separate
sensing means 89 operable to sense the decreasing dimensions of the rolls
of material.
Figure 9 shows the sensing means 89 mounted in close proximity
to, For example, roll 14. Sensing means 89 comprises in this particular
embodiment, in an assembly shown in part section in Figure 10, which
includes:- a right angle mounting bracket 90 attached by cap screws 91 to
frame F; a mounting plate 92 is adjustably mounted to bracket 90 by cap
screws 93. Mounting plate 92 is in this example attached by welding to the
vertically positioned main body 94 of the assembly. 3Ody 94 is tubular and
has an upper section 95 adapted to receive rotatable member 96, the upper
portion 96Q of member 96 rests upon thrust bearings 97; the intermediate
portion 96B of member 96 is retained between roller bearings 98; and the
lower portion 96C extends into the lower section 95A of body 94. Potentio-
meter or proportional feed back transducer 99 is attached to the lower
section 95A and its shaft is coupled by sleeve 100 to lower portion 96C of
member 96 to be operationally rotatable therewith.
Upper portion 96A of member 96 carries arm means 101 which
extends outwardly of member 96 to contact roll 14. The free rotation of
member 96 is constrained by spring 102 which extends between member 96 (pin
103) and pin 104 the latter being fixed to extend upwardly from mounting
plate 92.
As can be seen, spring 102 maintains arm 101 in constant contact
with the edge of roll 14. As the diameter of roll 14 decreases member 96
rotates transducer 99, which in turn sends an electrical signal representa-
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tive of this decrease in roll diameter, to the isolation amplification
module 88 (Figure 6), thus effecting a continuous and automatic adjustment
of the speed of the appropriate motor M.
In the arrangement of Figures 9 and 10, mounting bracket 90 is
provided with slots 105 which accept cap screws 93 and permit adjustment of
mounting plate 92 and hence sensing means 89 towards or away from roll 14.
Referring back to the principal operation of the drive assembly,
as the polyethylene strip 12 or the paper 16 passes over the rod 28 of
dancer 22 it has a tendency to rotate the dancer rod 22. The amount by
which the dancer rod 22 is rotated is a function of the speed, or more
speciFically the tension of the material 12 or 16 at that point. The more
the dancer rod 22 is rotated or out of alignment from its initially set
position, the more the speed must be adjusted. Consequently, as the dancer
rod 22 rotates the shaft 30 and the gear 70 rotates the gear 78 of potentio-
meter 80 which sends a signal to isolation amplification module 88 which
sends a signal to motor controller 86 which then Feeds a signal via the
reversing logic module 84 for adjusting the speed of motor M.
Should the polyethylene strip 12 or paper 16 be exhausted on
` the rolls 10 or 14 respectively, then the spring 50 has a tendency to pull
the dancer rod 22 upwards and to cause a rotation of shaft 30 to be applied
to gear 70 and to gear 78 and to cause potentiometer 80 to send a signal to
mo~or M to stop turning As has been previous1y described, if the motor
ceases to turn or to input a torque to worm gear drive W, then the steep
ratio of the worm gear drive causes the roll 10, 14 and 20 respectively to
cease to turn.
Likewise, if for some reason the tension should be decreased,
the dancer rod 22 will move upwardly and cause a signal to be transmitted to
motor M and cause the variable speed motor M to slow down. The input speed
to worm gear drive W will therefore be decreased and cause the roll 10, 14
or 20 to slow down.
In previous machines the maintenance of the proper tension had
to be continuously monitored by a skilled operator during the complete un-
winding of the material from the roll.
It should be appreciated that the present invention is a means
for adjusting the speed of the rolls 10 and 14. The rolls 10 and 14 are
driven through motors M and worm gear drive W as opposed to previous systems
in which the material was pulled from the rolls 10 or 14.
An additional embodiment of the disclosed invention is best
shown in Figure 8. A driven feed roll 90 containing a strip 92 is mounted
to frame F. The strip 92 may be polyethylene, paper, the joined polyethy-
lene paper strip above described, or any other suitable material or
materials. The driven feed roll 90 feeds the strip 92 to a dancer rod 22
as above described~ and to table 94. The material 92 passes along table 94
to cutting means 96 for cutting, slicing, perForating, sealing, collating
or any other operation that may be necessary.
Although only one driven feed roll 90 is disclosed in Figure 8,
it should be obvious that any number of rolls may be mounted to frame F and
it is not necessary that the strip 92 be joined prior to mounting roll 90
on frame F. Should multiple rolls be used, then the joining means 18 may
be mounted on frame F prior to cutting or operating means 96.
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By way of a more general description of operation, the first
proceeding involving the roll drive apparatus according to the invention
would naturally be the loading of a roll of material onto the roll drive
shaft. As this is done, the roll diameter sensincJ arm 10 is automatically
offset according to the diameter of the roll. As can be seen in Figure 10,
as the arm is offset, the transducer 99 (potentiometer) is also rotated
giving a voltage signal to the isolation amplification module 88.
After the roll is on the shaft it will be necessary to unwind
some product in order, for example, to splice into an existing web. This
can be accomplished by manually offsetting the dancer asse~bly which will
automatically feed out material. However, it will be appreciated that pro-
vision may be made -For manual or automatic selection of functions.
In the manual mode, the operator would simply set the roll drive
control system (not shown) on manual (versus automatic) then actuate until
~5 enough product had been unwound. (Note: provision would be made to adjust
the manual feed rate).
Once the splice is made, the slack in the unwound material will
obviously have to be taken up~ The reversing logic module 84 is provided
for that purpose~ By means o-F conventional external switching within the
drive control system, the motor is run in reverse until the slack is taken
up and then the control is put back into an automatic forward mode. (Here
again, provision will be made for adjusting the reverse speed).
On the initial set up of the roll drive assembly, the dancer
assembly should be balanced by adjustment o-F the counterweight ~6. This
will allow direct sensing of tension against the spring 50. The spring rate
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can be either predetermined, or adjustable to give the desired tension on
~he unwinding material.
The controller 86 and isolation module 88 are also, as w-ill be
appreciated, adjusted to predetermined values.
In operation, as heretofor described, the tension on the web
will cause the dancer assembly 22 to "pull down", which will automatically
cause the motor M to respond, upon receiving a voltage signal from the
potentiometer 80. The dancer will then stabilize at the operating position,
with any change in tension beins thereafter compensated by change in the
motor speed. That is to say, if the dancer assembly rotates downwardly too
far, the signal from poteniometer 80 will cause the motor to speed up; con-
versely if the dancer rides too high, the signal will cause the motor to
slow down.
As the roll diameter diminishes, the signal from the roll
sensing apparatus also changes (Figures 9 and 10). This aids in maintaining
a stable tension. As was mentioned previously, if the dancer arm moves from
its desired position, the motor will strive to correct the situation. How-
ever, without a diameter sensing means, the same amount of motor adjustment
would be made for a large roll as for a small roll. It is readily apparent
that to sllpply the same amount of material -from a small roll as from a large
roll, it will be necessary to rotate the small roll faster. Therefore, to
maintain a satis~actorily stable feed rate, the acceleration rate of the
motor must also be adjusted as the roll diameter diminishes.
While this invention has been described as having a preferred
design, it is understood that it is capable of further modification, uses
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and/or adaptations of the invention following in general the principle of
the invention and including such departures from the present disclosure as
come within known and customary practice in the art to which the invention
pertains, and as may be applied to the central Features hereinbefore set
forth, and fall within the scope of the invention o-F the limits of the
appended claims.
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