Remote control for adjustable-curvature roll

Disclosed is a remotely-controlled adjustable-curvature roll of the present invention which includes a hollow, cylindrical axle in which two rods are inserted. Each of the rods is securely fastened to an endplate at one end of the axle, and the opposite end of each rod is threaded within one of two oppositely rotating intermeshed gears. An air-impact motor is connected to one of the meshed gears to rotate the gear to which it is connected. The rotation of the gears in one direction causes an increase in the compression applied to one of the rods while at the same time exerting an increased tension on the other rod which is connected to the oppositely rotating gear. This combination of tension and compression causes the curvature of the roll to change. A remote control unit regulates the flow of air from an air supply to the air-impact motor. The remote control unit includes a filter for filtering the air supply and an oil mist lubricator for adding a lubricant to the air supply. An indicator included in the remote control unit provides a reading of the amount of bow in the roll. The axle may be surrounded by an outer sleeve which rotates, through the aid of ball bearings, around the axle.

BACKGROUND OF THE INVENTION 
The present invention relates to curved rolls or bars useful in the control 
of flexible sheet or web materials, and more particularly to curved rolls 
or bars, the radius of curvature of which is adjustable by remote control. 
The present invention also relates to straight rolls or bars which may be 
adjustably curved in opposite directions in a single plane by remote 
control. 
Longitudinally curved rolls or bars of a type whose degree of curvature is 
adjustable have found wide use for the lateral spreading and expansion of 
sheet materials such as cloth, paper, foil, plastic film, webs of tire 
cord and the like, both to control the width of the material and to remove 
wrinkles. Such rolls or bars are also used for correcting bow distortions 
of the weft threads of woven goods or the courses of knit goods. Although 
in many applications curved rolls or bars having a fixed degree of 
curvature or bow are satisfactory, it is often necessary or desirable to 
provide means for changing the curvature of the roll or bar in order to 
obtain better control of the processing under varying conditions. 
In known rolls, it has proven to be advantageous to incorporate a tension 
and a compression member within a centrally positioned axle of the roll. 
In U.S. Pat. No. 3,838,480 a solid axle is split, and a threaded 
screw-like adjusting means applies tension to one split portion of the 
axle and compression to another portion of the axle which lies on the 
opposite side of a neutral bending axis of the axle. The equally applied 
tension and compression causes a change in the curvature of the axle. 
Rolls having one piece, split axles have a number of shortcomings. First, 
the bending force is not evenly distributed across the axle. Also, if 
either the tension or compression member breaks, the entire axle must be 
rebuilt, and the cost of the construction is high. 
In other known adjustable deflection rolls, such as the roll of U.S. Pat. 
No. 3,500,524, a compression member and a tension member are snugly fit 
within a hollow, circular, straight cylindrical axle. The two members 
extend lengthwise within the axle, and they meet on a neutral axis of 
transverse bending of the axle. The two members are longitudinally 
slidable relative to one another and to the axle. When the curvature of 
the roll is adjusted, the member being compressed lies on the convex side 
and the member which is in tension lies toward the concave side. To adjust 
the tension and compression members, two adjusting screws for each 
member--one located at each end of a member--are rotated by an amount 
appropriate to provide the necessary compression and tension. This roll, 
however, is not a bowed roll. Rather it is a straight roll which deflects, 
and in operation the roll will attempt to return to a straight position. 
Such rolls, also only adjust in one direction, and they cannot reverse the 
direction. 
Adjustable deflection rolls of the type described in U.S. Pat. No. 
3,500,524 also have a number of shortcomings. First of all, screws must be 
adjusted on both ends of the roll, and therefore, clearance must be left 
on both sides of the rolls. Such a need for clearance prevents the rolls 
from being used in certain tight environments, and in fact, most web 
processing machines have only a single "tending" side from which 
adjustments are made. Secondly, the increased length imposes difficulties 
and limitations where such rolls are required to be mounted between the 
frames of an existing machine. Thirdly, the two screws must be rotated by 
an equally opposite amount, and the accuracy of such adjustment will never 
be perfect. Finally, the roll can only be adjusted in one direction from a 
straight or curved condition, and this limits maximum adjustment to only 
50% of what could be achieved with the same elements with adjusting force 
reversal. 
Adjustable curvature rolls currently available utilize a means of 
adjustment which is located directly on the roll and must be manually 
adjusted. When rolls are situated in locations that do not allow much 
clearance on either end of the roll, adjustment proves to be difficult and 
time consuming. In addition, manual adjustment of a roll may require 
special tools, and great care must often be taken in order to precisely 
adjust the curvature of the roll. Moreover, manually adjustable rolls do 
not generally provide a meaningful reading of the degree of curvature of 
the roll. 
It is therefore a principal object of the present invention to provide an 
adjustable-curvature roll or bar utilizing separate tension and 
compression members inserted in a hollow, cylindrical axle, the curvature 
of which can be remotely, accurately, and reliably adjusted in both 
directions from a neutral position. 
It is a further object of the present invention to provide an 
adjustable-curvature roll having separate tension and compression members, 
both of which are actuated by a remotely controlled adjusting means. 
It is a still another object of the present invention to provide a means 
for accurately displaying the actual amount of bow in an adjustable 
curvature roll. 
SUMMARY OF THE INVENTION 
The adjustable-curvature roll of the present invention includes a hollow, 
cylindrical axle in which a tension and a compression rod are inserted. 
Each of these rods is securely fastened to an endplate at one end of the 
axle, and the opposite end of each rod is threaded within one of two 
oppositely rotating intermeshed gears. A remotely controlled adjusting 
device is connected to one of the meshed gears, and causing the adjusting 
device to rotate the gears in one direction causes an increase in the 
compression applied to one of the rods while at the same time exerting an 
increased tension on the other rod which is connected to the oppositely 
rotating gear. The adjusting device can also be rotated in the opposite 
direction to decrease the compression applied to one of the rods and to 
decrease tension on the other rod. This combination of a change in tension 
and compression causes the curvature of the roll to change. 
The remotely controlled adjusting device in one embodiment is an impact 
type air motor similar to the motors used in air impact wrenches. The air 
impact motor output shaft is connected to one of the two rotating 
intermeshed gears. The motor in turn is connected to a remotely situated 
unit which controls the operation of the motor and hence the curvature of 
the roll. The remotely situated unit also preferably includes a digital 
readout of the precise amount of curvature of the roll. This readout is 
based on the amount of rotation of one of the gears connected to one of 
the rods. 
The axle is surrounded by a rotatable outer surface which rotates, through 
the aid of ball bearings, around the axle. The purpose of the axle is to 
provide a control of the contour of the rotatable outer surface of the 
roll. The term "roll" is intended to describe the assembly of the "axle" 
and the "rotatable outer surface". In some embodiments, the "rotatable 
outer surface" may be a series of rigid cylindrical spools or cylinders. 
In other embodiments, the "rotatable outer surface" is a rubber sleeve. 
These and other features and objects of the present invention will be more 
fully understood from the following detailed description which should be 
read in light of the accompanying drawings in which corresponding 
reference numerals refer to corresponding parts throughout the several 
views.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As shown in FIGS. 1-3, the improved roll 10 of the present invention 
includes a longitudinally-curved hollow axle 12 in which two rods 14, 16 
are mounted. The axle 12, while in use, has an arcuate configuration, and 
may be covered with a rotating rubber sleeve 40 as described below. As 
constructed, the axle 12 may be either curved or straight. 
As shown in FIGS. 7a and 7b, each of rods 14, 16 are secured to one end 12a 
of the axle 12. In the embodiment of FIG. 7a, each end 14a, 16a of rods 
14, 16, respectively, are welded to an end plate 18 of the axle 12. In the 
alternate preferred embodiment shown in FIG. 7b, threaded bushings 19 
mounted inside the end plate 18 receive the rods 14, 16 through threads 
20. This alternate embodiment allows the rods 14, 16 to be unscrewed 
thereby avoiding the necessity of cutting open the roll to gain access to 
the rods. 
As shown in FIGS. 3 and 4, the opposite ends 14b, 16b of rods 14, 16, 
respectively, are threaded into two oppositely rotating, mating, spur 
gears 22, 24. The rods themselves do not rotate and the spur gears 22, 24 
have internal threads which accept the external threads on ends 14b, 16b 
of rods 14, 16. The threading of the rods 14, 16 into the gears 22, 24 
allows the engaging of the rods in a manner sufficient to produce the 
necessary counteracting forces of tension and compression. The two rods 
14, 16 are separated from each other along their lengths by appropriately 
positioned spacers 26 which reduce the unsupported span of the rods 14, 16 
to a safe limit which will not allow buckling of the rods when curvature 
of the roll is increased or decreased. The spacers 26 are preferably 
welded to these rods so that every other spacer is welded to rod 14 and 
the spacers not welded to rod 14 are welded to rod 16. 
As shown in FIGS. 2-4, the roll 10 has an elongated neck which houses the 
gears 22, 24. A remotely controlled adjusting device, not shown in FIGS. 
2-4 but shown in FIGS. 9-10, 15 attached on the exterior of housing 28 to 
a splined extension shaft 29 of gear 24. As the remotely controlled 
adjusting device applies torque to gear 24 in a manner described below, 
gear 24 rotates in one direction and gear 22 will rotate in the opposite 
direction. As stated above, the rods do not rotate, and therefore, the 
rotating of gear 24 in one direction causes the pushing of rod 16 relative 
to end 12a of the axle 12. At the same time, rod 14 is pulled relative to 
end 12a of the axle 12. When a rod is pulled it is put under tension, and 
when a rod is pushed it is compressed. When the gear 24 is rotated in the 
opposite direction, the pushing of rod 16 and the pulling of rod 14 is 
reduced or even reversed. 
The terms "pushing and pulling" are not necessarily used in their ordinary 
sense here. When the roll is in use, one rod is under compression and the 
other rod is under tension. The pulling of a rod under tension increases 
the tension and the pulling of a rod under compression reduces the 
compression rather than actually pulling the rod. Likewise, the pushing of 
a rod under compression increases the compression and the pushing of a rod 
under tension reduces the tension rather than actually pushing the rod. 
The pushing or pulling of rods 14, 16 results in an adjustment of the 
curvature of the axle 12 in the following way. As rod 16 is pushed and put 
under an increased compression it causes the portion of the roll axle in 
which it lies to undergo tensile strain while the opposite portion of the 
roll axle is caused to undergo compressive strain by the pulling, and 
subsequent resulting increased tension, of rod 14. Opposite rotation of 
gear 24 will reduce both the compression in rod 16 and the tension in rod 
14 resulting in an opposite reaction in the axle. 
This adjustment of the bow of the roll is technically accomplished by 
producing equal and opposite force couples at each end 12a, 12b of the 
axle 12. The couples are actually produced at the ends of the axle 12, but 
they are projected along the length from both ends of the axle as equal 
couples. When the couples are applied to the axle they will produce a 
change in the radius of curvature of the axle, and the change in the 
radius of curvature will be uniform over the entire length of the axle 12. 
This roll provides advantages over other known rolls insofar as in known 
variable curvature rolls there is variation in the radius of curvature 
closer to the end of the axle where the bowing mechanism is present. 
Furthermore, the variable curvature roll shown in FIGS. 1-4 has an axle 
with the same load carrying capacity and the same stiffness in all planes. 
In known variable curvature rolls, there is a high stiffness in the plane 
perpendicular to the plane in which the bow is present but in the plane of 
the bow, the stiffness is approximately one-quarter of the maximum 
stiffness. As a result in certain applications, one must be very concerned 
about changing the application of the load from the sheet. If it is in the 
plane of the roll curvature, the curvature of the axle will change 
appreciably when a load is applied. 
The axle 12 is covered by a rotatable outer surface which may comprise a 
series of shells 46 as shown in FIG. 8 or a rubber sleeve 40 as mentioned 
above and shown in FIG. 2 mounted on shells 46. It is this outer surface 
which contacts the material to be straightened, unwrinkled, etc. Across 
the surface of the axle 12 are placed a number of rolling bearing elements 
44. Cylindrical shells 46 are placed over the bearings and support the 
interior surface of the sleeve. In this fashion, the sleeve and/or 
cylindrical shells rotate around the axle without the axle actually 
rotating. 
A remotely controlled adjusting device 48 of the present invention is shown 
attached to a roll 10 in FIGS. 9-10. An air driven impact motor 50 (such 
as an impact motor manufactured by Chicago Pneumatic) is integrally 
mounted at the adjusting end 10b of the roll 10. The motor 50 is connected 
to the splined extension shaft 29 of gear 24, although any other known 
means of connecting a motor to a shaft may also be employed. A 
potentiometer 52 is provided for determining the amount of rotation of the 
gears 22, 24 to provide a reading of the degree of curvature in the roll. 
A remote control unit 60 for operating the adjusting device 48 will now be 
described with reference to FIGS. 11-13. One of the principal purposes of 
the unit 60 is to control the flow of air applied to the air motor 50 from 
an air supply 61. The control unit 60 will typically include a filter 62 
which collects miscellaneous dirt and removes some water from the air 
passing through the filter. An oil mist lubricator 64 adds a small amount 
of oil to the air to lubricate the air motor parts and to prevent rusting 
of the motor parts. Air from the air supply 61 generally enters the filter 
at between 60 and 125 psi and a regulator 66 attached to the filter 
adjusts the pressure to a preselected value, preferably 60 psi. A gauge 68 
is provided so that the air pressure may be visually monitored. A four-way 
valve 70, controlled by lever 72, operates to govern the air applied to 
the air motor 50 to thereby increase or decrease the bow in the roll. For 
example, when lever 72 is pulled, there is an increase in the bow amount 
and when lever 72 is pushed back toward the display unit, there is a 
decrease in the bow amount. 
The valve 70 controls this increase and decrease in the bow by selectively 
applying air through an appropriate air line to the air impact motor 50. 
As shown in FIG. 11, when the valve is in one position, air is supplied to 
the motor through air line 74 and returns through air line 76 to the valve 
70 and then through the valve 70 to the ambient atmosphere. This causes 
clockwise rotation of the motor 50 which in turn causes a clockwise 
rotation of the gear 24 and a counterclockwise rotation of the gear 22, 
thereby increasing the bow in the roll. When the lever 72 is pushed, air 
is supplied to the motor through the air line 76 and air line 74 acts as 
the return line so that air is supplied to the air motor 50 in a manner 
which will cause a counterclockwise rotation of the air motor 50 which in 
turn results in a counterclockwise motion of the gear 24 and a clockwise 
motion of the gear 22 thereby resulting in a decrease in the bow of the 
roll. A supplementary point of discharge of air from the motor 50 is also 
provided to increase motor power and efficiency. This exhaust is common 
for both directions of motor rotation so that the air can discharge 
directly from the motor 50 to the ambient atmosphere. Such an open line, 
however, might allow the motor 50 or line 78 to be contaminated by the 
wet, dirty atmosphere at the roll end. Therefore, air line 78 is brought 
back to the remote control unit 60 where the atmosphere is clean. 
The housing 79 for remote control unit 60 of the present invention is 
preferably a corrosion-resistant, sealed enclosure which is designed to 
provide convenient bow adjustment and long, trouble-free operation. The 
housing 79 is suitable for wet and dry enviornments and ambient 
temperature up to 160.degree. F. As described above, the filter 62 and 
lubricator 64 also assure trouble-fee operation of the air motor 50 which 
drives the bow-adjusting mechanism 48. The regulator provides a controlled 
air pressure for uniform operation of the air motor in spite of variations 
in the pressure of the mill air. 
Another principal feature of the present invention is an automatic bow 
display 80 which shows the actual amount of bow in the roll. The display 
is preferably a LCD-type (liquid crystal display). The circuitry shown in 
FIG. 13, is provided to read the position of the rotary potentiometer 52 
which is connected to gear 22. The potentiometer 52 is calibrated to make 
the display read out the actual bow in the roll in inches (or any other 
predetermined units) based on the resistance of the potentiometer 52 in 
the end of the roll. Standard long-life batteries are utilized to make the 
apparatus as maintenance free as possible. An indicator 82 on the display 
80 blinks when the operating limit of the bow adjustment is reached. This 
light is provided to alert the operator to the normal limits so that he 
will not try to adjust the roll further. Another indicator is preferably 
provided to indicate when the batteries should be replaced. 
Referring to the circuit for operating the bow indicator display 80 of FIG. 
12, the visual display circuitry 90 includes a standard liquid crystal 
display 92 such as obtainable from the Amperex Corporation under 
designation LC703831-300.28/IE. A converter chip 94 is provided to enable 
an analog-to-digital conversion of the bow signal to thereby operate the 
liquid crystal display 92. A suitable converter chip is that sold by 
Intersil under the designation ICL7126CPL. Such a chip has the principal 
advantage that it has low power requirements. RC circuit 98 is provided to 
set the frequency of an internal oscillator that controls the internal 
timing of the converter 94, and the converter utilizes capacitors 100, 102 
and resistors 104, 106 to form an integrator which is used to perform the 
conversion. Capacitor 108 stores the reference voltage during the 
conversion. The convertor measures the voltage across its input pins 31 
and 30 and compares it to the reference voltage across its pins 36 and 35. 
If the voltages are equal, the converter will display 9.99. If the input 
voltage is one-half of the reference voltage, the display would be 5.00. 
Capacitor C5 and resistor R8 provide low pass filtering to eliminate noise 
that would cause a display to "jump" around. Gate 96 drives the fixed 
decimal point. 
The circuit section labelled 120 generates an adjustable offset needed for 
calibrating the indicator unit 80. The operational amplifier 122 generates 
a voltage that is equal to -V.sub.ref. This voltage is available at the 
output of the operational amplifier 122. By adjusting resistor 126 any 
voltage between V.sub.ref and -V.sub.ref can be sent to the output of the 
circuit section 120. The operational amplifier 122 and related circuitry 
allows the offset voltage to track the reference voltage as the batteries 
wear down, and as a result the displayed value will not change as the 
batteries die. 
The circuit section 130 is provided to generate the signals necessary to 
measure the bow and the limits. The reference voltage +6V generated by the 
battery is connected to terminal 132 and 134. A fraction of that voltage 
is returned at terminal 136 and placed across resistor 138. This voltage 
is also inputted to amplifiers 140, 142. The potentiometer 138 scales the 
input depending on the sensitivity needed for a particular bow roll. 
Potentiometers 146, 148 generate plus and minus limit values. When either 
of these limits are exceeded by the value across terminal 136, one of the 
amplifer outputs goes low causing the common point of diodes 146, 148 to 
switch from +9V to 0V. 
In the circuit section labelled 150, the outer limit signal is detected 
from circuit section 130 in order to cause the limit signal on the display 
to blink. Gate 152 enables an oscillator comprising gates 154, resistor 
156 and capacitor 158. When enabled, the oscillator causes the limit 
signal to blink. 
Circuit section portion 160 monitors the overall 9V battery voltage. When 
this voltage drops below a preset value the battery signal will become 
visible on the display. At this point, there is still some life left in 
the batteries, but they should be replaced as soon as possible. 
While the foregoing invention has been described with reference to its 
preferred embodiments, it should not be limited to such embodiments since 
various alterations and modifications will occur to those skilled in the 
art. For example, any adjusting mechanism that can be mounted to remotely 
rotate a gear may be employed. Furthermore, other types of control may be 
utilized provided they can stop and start the operation of adjusting 
mechanism. The remote control unit can also be operated automatically 
rather than manually. In such a situation, a solenoid valve could replace 
the four-way valve 70, and the solenoid valve would be operated by a 
central control until a preset valve of bow is achieved. All such 
variations and modifications are intended to fall within the scope of the 
appended claims.