Methods and apparatus for adjusting nip rolls

Abstract

Methods and apparatus for adjusting nip rolls are disclosed. In particular, a web material is moved between a first roll and a second roll opposite the first roll and a pressure value associated with an amount of pressure applied to the web material by the first and second rolls is determined. The amount of pressure applied to the web material is controlled by moving one of the first and second rolls based on the pressure value.

Description

FIELD OF THE DISCLOSURE

The present disclosure relates generally to printing processes and more particularly to adjusting nip rolls in printing processes.

BACKGROUND

A printing press is typically implemented using a plurality of rolls that are configured to guide a moving web material (e.g., a paper material, a plastic material, a textile material, etc.) through a printing press. The plurality of rolls often includes opposing nip rolls that are typically configured to nip, squeeze, or otherwise apply pressure or force to opposing sides of the moving web material. For example, folding machines (i.e., folders) include one or more sets of opposing nip rolls that are configured to receive and make one or more folds in the moving web. Opposing nip rolls may be used to form a fold in the moving web by pressing opposing faces of adjacent panels on either side of a fold line against one another and forming a crease at the fold line.

The pressure or force applied to the moving web by opposing nip rolls is typically set by adjusting the position of the nip rolls once during a make-ready process and locking the nip rolls into position for the duration of a production run. Many operations of the printing press may be adjusted during the make-ready process, which is typically performed prior to starting each production run. In particular, the pressure applied to the moving web by opposing nip rolls may be adjusted by separating the nip rolls by an optimal distance to ensure that the radial surfaces of the nip rolls apply an appropriate pressure to the moving web given the thickness of the web material. Moving the nip rolls too close to each other may result in marring, tearing, or otherwise damaging the moving web. However, moving the nip rolls too far apart may result in poor fold formations and/or other degradations in quality.

The optimal distance by which nip rolls should be separated is often empirically determined using known methods. One known method involves a skilled machine operator manually pulling one or more sheets of web material (e.g., paper) through opposing nip rolls and estimating the amount of pressure applied to the sheets of paper by the nip rolls based on the amount of force required to pull the material through the nip rolls. For example, too much pulling force indicates that the nip rolls are too close together and must be separated.

If the operator believes that the pulling force is either excessive or insufficient, the machine operator then changes the distance by which the nip rolls are separated to increase or decrease the pressure applied by the nip rolls. The nip roll adjustment process is then repeated one or more times until the operator determines that the amount of pressure applied by the nip rolls is correct for a given material at a given thickness, at which point the nip rolls are locked in position for the duration of the production run.

Traditional methods such as the method described above for adjusting nip rolls are often time consuming and require a skilled machine operator. In addition, locking the nip rolls in position for the duration of a production run prevents changing a web material type or thickness without shutting down the printing press and adjusting the nip rolls.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example printing press within which the nip roll adjusting methods and apparatus described herein may be implemented.

FIG. 2 illustrates an example roll assembly that may be located in the folder of FIG. 1.

FIG. 3 illustrates a set of nip rolls in a known configuration used to determine a pressure applied by the nip rolls to a web material.

FIG. 4 illustrates an example nip roll adjustment apparatus that may be used to automatically determine and adjust a pressure applied by opposing nip rolls to a moving web captured therebetween.

FIG. 5 is a flow diagram of an example method that may be used with the adjustment apparatus of FIG. 4 to automatically determine and adjust an amount of pressure applied by opposing nip rolls to a moving web material.

FIG. 6 is an example system that may be used to implement the example methods and apparatus described herein.

FIG. 7 is a block diagram of an example processor system that may be used to implement the example methods and apparatus described herein.

DETAILED DESCRIPTION

Although the following discloses example systems including, among other components, software executed via hardware, it should be noted that such systems are merely illustrative and should not be considered as limiting. For example, it is contemplated that any or all of these hardware and software components could be embodied exclusively in hardware, exclusively in software, or in any desired combination of hardware and software. Accordingly, while the following describes example methods, systems, and apparatus, persons having ordinary skill in the art will readily appreciate that the examples provided are not the only way to implement such example methods, systems, and apparatus.

In general, the example methods and apparatus described herein may be used to adjust the nip rolls typically found in printing presses used to manufacture books, magazines, catalogs, or the like. Nip rolls are often used in folding machines (i.e., folders) to nip, squeeze, or otherwise apply pressure to a moving web material (e.g., a paper material, a plastic material, a textile material, etc.). Folders are configured to receive a moving web material and fold the moving web one or more times via a plurality of rolls. As described in greater detail below, a feedback loop is used to hold constant the pressure or force applied to the moving web by opposing nip rolls. Pressure changes between opposing nip rolls may be caused by, for example, changes in material thickness (e.g., within a roll of material, between rolls, etc.) and changes in web tension. Such pressure changes may be monitored using a load sensor operatively coupled to at least one of the opposing nip rolls. When the load sensor indicates a change in pressure, a control signal may be communicated to an actuating device to change or vary the distance between the opposing nip rolls.

FIG. 1 illustrates an example printing press 100. The example printing press 100 includes a printer 102, a folder 104, a cutter 106, and a web material 108 moving therethrough in a direction generally indicated by arrow 110. The arrangement of the printer 102, the folder 104, and the cutter 106 is shown for example purposes only and it would be obvious to one having ordinary skill in the art to include any number of printers, folders, and cutters and to include machines used for any other operations (e.g., stacking, binding, etc.) in the example printing press 100.

In the example printing press 100, the web material 108 moves through the printer 102 at which point information is imaged or printed onto the web material 108. The web material 108 is then moved through the folder 104, which has a plurality of rolls including nip rolls as described in greater detail below in connection with FIG. 2. The folder 104 may be configured to fold the web material 108 one or more times. After the web material 108 is folded it is moved through the cutter 106, which may be configured to cut the web material 108 to form signatures that may be used to form, for example, books, magazines, catalogs, etc.

FIG. 2 illustrates an example roll assembly 200 that may be located in the folder 104 of FIG. 1. The web material 108 is guided and folded by the example roll assembly 200 as the web material 108 moves through the folder 104 in a direction generally indicated by arrow 202. The example roll assembly 200 includes a lateral guide roll 204, forming rolls 206a and 206b, and opposing first and second nip rolls 208a and 208b. However, the example roll assembly 200 could be modified to include more or fewer rolls to achieve the same or similar results using the example methods and apparatus described herein. In addition, any number of roll assemblies similar or identical to the example roll assembly 200 may be located within the folder 104 and arranged in a manner that enables forming a plurality of folds in the web material 108. The rolls 204, 206a, 206b, 208a, and 208b may be made of any suitable material including metal, plastic, rubber, etc.

The lateral guide roll 204 is configured to receive the web material 108 from, for example, a supply roll, another machine (e.g., the printer 102), or another roll assembly within the folder 104 and to guide the web material 108 toward the forming rolls 206a and 206b.

The forming rolls 206a and 206b are configured to initially form or prepare the outer edges of the web material 108 for a folding operation. In particular, the forming rolls 206a and 206b are spaced apart by a distance that is less than the width (w) of the web material 108. In this manner, the forming rolls 206a and 206b move the outer portions of the web material 108 closer together about a folding line 210 as shown in FIG. 2.

The web material 108 is then moved between the opposing first and second nip rolls 208a and 208b. The nip rolls 208a and 208b are configured to fold the web material 108 about the folding line 210 to form adjacent panels having opposing faces pressed together. The nip rolls 208a and 208b may be configured to apply sufficient pressure or force to form a crease at the folding line 210. More specifically, the first nip roll 208a has a first radial surface 210a (i.e., a first outer surface) opposing a second radial surface 210b (i.e., a second outer surface) of the second nip roll 208a configured so that the nip rolls 208a and 208b apply an amount of pressure or force via their opposing radial surfaces 210a and 210b to the web material 108 as the web material 108 moves therebetween.

FIG. 3 illustrates a set of nip rolls 302a and 302b in a known configuration used to determine an optimal pressure applied by the nip rolls 302a and 302b to a web material (e.g., the web material 108 of FIGS. 1 and 2). In particular, a skilled operator may use a configuration substantially similar or identical to the known configuration shown in FIG. 3 during a make-ready process to determine the distance by which nip rolls (e.g., the nip rolls 302a and 302b) should be separated from one another so that the nip rolls 302a and 302b apply an optimal pressure or force to a web material during a production run.

In general, a make-ready process may be performed prior to each production run of a production line (e.g., the example printing press 100 of FIG. 1), during which various adjustments and calibrations may be made to machines in the production line. For example, if a web material changes between production runs, skilled operators re-calibrate or adjust various machines (e.g., the printer 102, the folder 104, the cutter 106 of FIG. 1) in the production line to ensure that the machines are adapted to work with the material characteristics (e.g., thickness, width, weight, etc.) of the web material to be used. A typical adjustment made by skilled operators includes setting positions of opposing nip rolls (e.g., the opposing nip rolls 302a and 302b) to ensure that an optimal pressure is applied to the web material.

As is known the nip roll configuration shown in FIG. 3 may be adjusted using a plurality of stacked sheets including two outer sheets 304 and 306 and a slip sheet 308 therebetween. The stacked sheets 304, 306, and 308 may be made from the web material that is to be used during a production run. An operator begins the known nip roll adjustment process by feeding the stacked sheets 304, 306, and 308 between the nip rolls 302a and 302b. Although three stacked sheets are shown in the example of FIG. 3, the number of sheets used may vary depending on the thickness of a web material (e.g., the web material 108 of FIG. 1) that is to be used during a production run and/or the number of folds in the web material moving through the nip rolls 302a and 302b.

After the stacked sheets 304, 306, and 308 are captured between the nip rolls 302a and 302b, the operator pulls the slip sheet 308 in a direction generally indicated by arrow 310. If the slip sheet 308 can be pulled out too easily, the operator may determine that the nip rolls 302a and 302b are positioned too far apart and, thus would not apply sufficient pressure to a web material (e.g., the web material 108 of FIG. 1) during a production run. On the other hand, if the slip sheet 308 requires too much force to be pulled through the nip rolls 302a and 302b or does not move, the operator may determine that the nip rolls 302a and 302b are positioned too close together and would apply too much pressure to the web material. The operator typically performs the pulling process repeatedly, each time adjusting the position of the nip rolls 302a and 302b, until the operator determines that the nip rolls 302a and 302b are separated by a distance that results in the application of an optimal pressure to the web material. The operator then locks the nip rolls 302a and 302b in the position at which they remain for the duration of a production run. If material properties (e.g., the thickness, material type, etc.) of a web material change during the production run, the printing press (e.g., the printing press 100 of FIG. 1) must be stopped and the nip rolls 302a and 302b must be re-positioned.

FIG. 4 illustrates an example nip roll adjustment apparatus 400 that may be used to automatically determine and adjust an amount of pressure applied by opposing nip rolls 402a and 402b to a moving web material 403. In general, the example nip roll adjustment apparatus 400 (i.e., the adjustment apparatus 400) may be configured to continuously monitor (i.e., measure) and maintain a substantially constant amount of pressure applied to the web material 403 by the nip rolls 402a and 402b regardless of changes in the thickness or other properties of the web material 403. For example, the adjustment apparatus 400 may adjust a distance by which the nip rolls 402a and 402b are spaced from one another to maintain a constant pressure on the web material 403. As shown in FIG. 4, the adjustment apparatus 400 includes the first nip roll 402a, the second nip roll 402b, a support frame 404, an actuator 406, an shaft 408, a support block 410, a load sensor 412, and a control system 414, all of which are operatively coupled as shown.

The first and second nip rolls 402a and 402b are separated by a distance that enables the rolls 402a and 402b to nip, squeeze, or otherwise apply a desired pressure or force to opposing sides of the web material 403. The nip rolls 402a and 402b may be substantially similar or identical to the nip rolls 208a and 208b described above in connection with FIG. 2. In addition, the web material 403 may be substantially similar or identical to the web material 108 described above in connection with FIG. 1. The first nip roll 402a is rotatably coupled to the support frame 404 and may be configured to translate toward and away from the second nip roll 402b as generally indicated by arrow 416. The second nip roll 402b may be stationary or mounted in a fixed position relative to the first nip roll 402a. Alternatively, both of the nip rolls 402a and 402b may be adjustable and movable to various positions.

The actuator 406 is operatively coupled to the shaft 408, which is operatively coupled to the support block 410. In general, the actuator 406 is configured to actuate the shaft 408 to cause the support block 410 to move in the directions generally indicated by the arrow 416. The support block 410, the load sensor 412, and the support frame 404 are mechanically coupled so that actuation by the actuator 406 causes the first nip roll 402a to move relative to the second nip roll 402b to adjust an amount of pressure applied to the web material 403 by the nip rolls 402a and 402b.

The actuator 406 may be any device suitable for moving the support block 410 such as, for example, a stepper motor, a linear motor, a pneumatic cylinder, a hydraulic cylinder, a solenoid, etc. The shaft 408 and the support block 410 are configured to work with the actuator 406. For example, if the actuator 406 is implemented using a stepper motor, the shaft 408 may be implemented using a screw having threads 418 and the support block 410 may include a threaded bore 420 therethrough so that the shaft 408 may be threadably coupled to the support block 410 as shown in FIG. 4. In this manner, the actuator 406 may rotate the shaft 408 to cause the support block 410 to move or translate in one of the directions indicated by the arrow 416. Alternatively, if the actuator 406 is implemented using a linear actuator such as a pneumatic cylinder or a hydraulic cylinder, the shaft 408 may be implemented using a rod that is mechanically coupled in a fixed position to the support block 410 and that slides into and out of the actuator 406.

The load sensor 412 is captured between the support frame 404 and the support block 410. The load sensor 412 is configured to measure an amount of force or pressure that is applied to the web material 403 by the first and second nip rolls 402a and 402b. The amount of force or pressure measured by the load sensor 412 increases as the support block 410 is moved toward the second nip roll 402b. For example, the pressure or force applied to the web material 403 and measured by the load sensor 412 may increase as the distance between the first and second nip rolls 402a and 402b decreases. The load sensor 412 may be implemented using any device suitable for measuring force or pressure such as, for example, a load cell.

The control system 414 may be implemented using a hardware system (e.g., the example system 600 of FIG. 6) and/or a processor system (e.g., the example processor system 710 of FIG. 7). Additionally, the control system 414 may be implemented using a programmable logic controller (PLC), which may be communicatively coupled via a network (not shown) to a central processing system (not shown) so that the PLC may be controlled and monitored from a remote location.

The control system 414 includes an information display 422 and an input interface 424. The information display 422 may be implemented using, for example, a liquid crystal display (LCD) or a light emitting diode (LED) display and may be used to display the pressure or force measurement information provided by the load sensor 412. The input interface 424 may be implemented using any type of suitable buttons or user interface for entering information into the control system 414. The information display 422 and the input interface 424 may be used by an operator to configure parameters associated with the adjustment apparatus 400 and to monitor performance to ensure that the adjustment apparatus 400 is functioning properly. For example, the input interface 424 may be used to input desired or predetermined minimum and maximum force or pressure threshold values corresponding to the amount of pressure to be applied by the nip rolls 402a and 402b during a production run.

The actuator 406 and the load sensor 412 are communicatively coupled to the control system 414 to form a nip roll adjustment feedback loop. The feedback loop may be configured to control an amount of force or pressure applied to the web material 403 by substantially continuously monitoring via the load sensor 412 the amount of force or pressure applied by the nip rolls 402a and 402b to the web material 403. For example, to apply a constant amount of pressure to the web material 403, the control system 414 may monitor the amount of applied pressure detected by the load sensor 412 and vary the position of the nip roll 402a via the actuator 406 based on detected pressure variations.

The control system 414 may be configured to process the force or pressure measurement information via a hardware circuit and/or software executed on a processor (e.g., the processor 712 of FIG. 7). The control system 414 may also be configured to communicate an electrical control signal to the actuator 406 that causes the actuator 406 to translate the first nip roll 402a relative to the second nip roll 402b to vary the amount of force applied to the web material 403. In general, the control system 414 may be configured to maintain a substantially constant amount of force or pressure or otherwise control an amount of pressure applied to the web material 403. For example, as described in greater detail below in connection with FIG. 5, the control system 414 may control the amount of pressure applied to the web material 403 by ensuring that the amount of force or pressure is maintained between predetermined minimum and maximum threshold values.

The feedback loop operates continuously so that as the actuator 406 moves the first nip roll 402a, the pressure sensor 412 can substantially simultaneously communicate force measurements to the control system 414. In this manner, the control system 414 may determine when to stop the actuator 406. In addition, the continuous operation of the feedback loop enables material properties (e.g., thickness) of the web material 403 to change during a production run without having to shutdown a production line (e.g., the example printing press 100 of FIG. 1) to adjust the nip rolls 402a and 402b.

Although the adjustment apparatus 400 is described above as being configured to automatically and continuously adjust the nip rolls 402a and 402b, the adjustment apparatus 400 may also be configured to operate in a manual mode. In the manual mode, the feedback loop is disabled and an operator is responsible for observing the force measurement on the information display 422 and inputting control information to the control system 414 via the input interface 424 to actuate the actuator 406 based on the force measurement.

FIG. 5 is a flow diagram of an example method 500 that may be used with the apparatus adjustment 400 of FIG. 4 to automatically determine and adjust an amount of pressure applied by opposing nip rolls (e.g., the opposing nip rolls 402a and 402b of FIG. 4) to a moving web material (e.g., the web material 403 of FIG. 4). In general, the example method 500 may be implemented in combination with the example nip roll adjustment apparatus 400 described above in connection with FIG. 4 and used to implement a nip roll adjustment feedback loop for monitoring and maintaining a pressure or force applied to the web material 403 by the nip rolls 402a and 402b during, for example, a printing press production run. As described below, the example method 500 may be used to maintain a substantially constant pressure or force on the web material 403 by ensuring that the force applied by the nip rolls 402a and 402b is maintained between predetermined minimum and maximum threshold pressure values.

The example method 500 may be implemented in software, hardware, and/or any combination thereof. For example, the example method 500 may be implemented in software that is executed on the processor system 710 of FIG. 7. The example method 500 may also be implemented in hardware such as, for example, a hardware system that is configured substantially similar or identical to the example system 600 described below in connection with FIG. 6. Alternatively, the example method 500 may be implemented manually by an operator using the information display 422 (FIG. 4) and the input interface 424 (FIG. 4) as described above in connection with FIG. 4. Although, the example method 500 is described below as a particular sequence of operations, one or more operations may be rearranged, added, and/or removed to achieve the same or similar results as those described herein.

Initially, measurement information is obtained from a load sensor (e.g., the load sensor 412 of FIG. 4) (block 502). The information may be obtained by, for example, a control system (e.g., the control system 414 of FIG. 4) in the form of a digital or analog electrical signal that corresponds to an amount of force or pressure applied by the nip rolls 402a and 402b (FIG. 4) to the web material 403 (FIG. 4).

A measured pressure value corresponding to an amount of pressure applied by the nip rolls 402a and 402b may then be determined (block 504). More specifically, the measured pressure value may be determined based on the measurement information received from the load sensor 412 using a conversion routine executed or performed by the control system 414. The conversion routine may involve the use of a look-up table stored in a memory (e.g., the system memory 724 and/or the mass storage memory 725 of FIG. 7). The look-up table may be used to store pressure or force values associated with the measurement information provided by the load sensor 412. For example, the measurement information may be a voltage value, current value, or any analog or binary encoded value that corresponds to an amount of pressure sensed by the load sensor 412 and that may be used to look up and retrieve a corresponding pressure value via the look-up table.

The measured pressure value may then be compared to a maximum threshold pressure value (block 506). If the measured pressure value is greater than the maximum threshold pressure value, the pressure applied to the web material 403 (FIG. 4) by the opposing nip rolls 402a and 402b (FIG. 4) is decreased (block 508). The pressure may be decreased by increasing the distance between the nip rolls 402a and 402b by causing the actuator 406 to drive the first nip roll 402a away from the second nip roll 402b.

If it is determined at block 506 that the measured pressure value is not greater than the maximum threshold pressure value, the measured pressure value is compared to a minimum threshold pressure value (block 510). If the measured pressure value is less than the minimum threshold pressure value, the pressure applied to the web material 403 by the opposing nip rolls 402a and 402b is increased (block 512). The pressure may be increased by decreasing the distance between the opposing nip rolls 402a and 402b by causing the actuator 406 to drive the first nip roll 402a toward the second nip roll 402b.

If it is determined at block 510 that the measured pressure value is not less than the minimum threshold pressure value or after the operations of block 508 or block 512 are completed, it is determined if monitoring of the pressure should be continued (block 514). If monitoring of the pressure should be continued, control is passed back to block 502, otherwise the process is ended.

Of course, any one or more signal conditioning techniques may be implemented with the example method 500 such as, for example, signal averaging, signal filters, noise reduction algorithms, hysteresis, etc. The signal conditioning techniques may be used to prevent or minimize erroneous signal interpretation and/or system oscillation. For example, an averaging technique may be applied to the measurement information obtained from the load sensor at block 502 to suppress any electrical noise spikes that may otherwise be interpreted as pressure values exceeding the maximum or minimum threshold pressure values. Hysteresis may be used to prevent or minimize oscillatory control of the actuator 406 when the measured pressure values are equal to or substantially equal to the maximum or minimum threshold pressure values.

FIG. 6 is an example system 600 that may be used to implement the example methods and apparatus described herein. In particular, the example system 600 may be used to continuously monitor and maintain an amount of force or pressure applied to a web material (e.g., the web material 403 of FIG. 4) by opposing nip rolls (e.g., the nip rolls 402a and 402b) as described above in connection with the example method 500 of FIG. 5. In addition, the example system 600 may be used to implement at least a portion of the example nip roll adjustment apparatus 400 of FIG. 4.

As shown in FIG. 6, the example system 600 includes a load sensor 602, a pressure meter 604, a comparator 606, and an actuator 608, all of which are communicatively coupled as shown. The load sensor 602 may be substantially similar or identical to the load sensor 412 described above in connection with FIG. 4 and may be configured to communicate force or pressure measurement information to the pressure meter 604 via, for example, a digital or analog electrical signal.

The pressure meter 604 may be configured to convert the measurement information obtained from the load sensor 602 to a measured force or pressure value using, for example, a look-up table as described above in connection with block 504 of FIG. 5. The pressure meter 604 may then communicate the measured pressure value to the comparator 606. The comparator 606 may be configured to compare the measured pressure value to predetermined maximum and minimum threshold pressure values as described above in connection with the blocks 506 and 510 of FIG. 5. The pressure meter 604 and the comparator 606 may be implemented using a PLC, the control system 414 (FIG. 4), the processor system 710 (FIG. 7), and/or any other suitable information processing system. Further, the functions of the pressure meter 604 and the comparator 606 may be implemented using hardware, software, or any combination thereof.

The actuator 608 may be substantially similar or identical to the actuator 406 of FIG. 4 and may be configured to obtain control signals from the comparator 606 that are associated with changing or adjusting the distance by which opposing nip rolls (e.g., the nip rolls 402a and 402b of FIG. 4) are separated from each another. For example, if the comparator 606 determines that a pressure value measured by the load sensor 602 is less than a minimum threshold pressure value, the comparator 606 may communicate a control signal to the actuator 608 that causes the actuator 608 to drive, translate, or otherwise move a slideable or variable position nip roll (e.g., the first nip roll 402a of FIG. 4) toward a stationary nip roll (e.g., the second nip roll 402b of FIG. 4), thereby increasing the amount of pressure applied to a web material (e.g., the web material 403 of FIG. 4) as described above in connection with block 512 of FIG. 5. Alternatively, if the comparator 606 determines that a pressure value measured by the load sensor 602 is greater than a maximum threshold pressure value, the comparator 606 may communicate a control signal to the actuator 608 that causes the actuator 608 to drive, translate, or otherwise move the first nip roll 402a away from the second nip roll 402b, thereby decreasing the pressure applied to the web material 403 as described above in connection with block 508 of FIG. 5.

Although the above example methods and apparatus are generally described with regard to nip rolls (e.g., the nip rolls 402a and 402b of FIG. 4) associated with folders (e.g., the folder 104 of FIG. 1) and more generally, with printing presses (e.g., the printing press 100 of FIG. 1), such example methods and apparatus may be adapted for use with any other machine and/or production line to achieve substantially similar or identical results as those described herein.

FIG. 7 is a block diagram of an example processor system 710 that may be used to implement the apparatus and methods described herein. As shown in FIG. 7, the processor system 710 includes a processor 712 that is coupled to an interconnection bus or network 714. The processor 712 includes a register set or register space 716, which is depicted in FIG. 7 as being entirely on-chip, but which could alternatively be located entirely or partially off-chip and directly coupled to the processor 712 via dedicated electrical connections and/or via the interconnection network or bus 714. The processor 712 may be any suitable processor, processing unit or microprocessor. Although not shown in FIG. 7, the system 710 may be a multi-processor system and, thus, may include one or more additional processors that are identical or similar to the processor 712 and that are communicatively coupled to the interconnection bus or network 714.

The processor 712 of FIG. 7 is coupled to a chipset 718, which includes a memory controller 720 and an input/output (I/O) controller 722. As is well known, a chipset typically provides I/O and memory management functions as well as a plurality of general purpose and/or special purpose registers, timers, etc. that are accessible or used by one or more processors coupled to the chipset. The memory controller 720 performs functions that enable the processor 712 (or processors if there are multiple processors) to access a system memory 724 and a mass storage memory 725.

The system memory 724 may include any desired type of volatile and/or non-volatile memory such as, for example, static random access memory (SRAM), dynamic random access memory (DRAM), flash memory, read-only memory (ROM), etc. The mass storage memory 725 may include any desired type of mass storage device including hard disk drives, optical drives, tape storage devices, etc.

The I/O controller 722 performs functions that enable the processor 712 to communicate with peripheral input/output (I/O) devices 726 and 728 via an I/O bus 730. The I/O devices 726 and 728 may be any desired type of I/O device such as, for example, a keyboard, a video display or monitor, a mouse, etc. While the memory controller 720 and the I/O controller 722 are depicted in FIG. 7 as separate functional blocks within the chipset 718, the functions performed by these blocks may be integrated within a single semiconductor circuit or may be implemented using two or more separate integrated circuits.

The methods described herein may be implemented using instructions stored on a computer readable medium that are executed by the processor 712. The computer readable medium may include any desired combination of solid state, magnetic and/or optical media implemented using any desired combination of mass storage devices (e.g., disk drive), removable storage devices (e.g., floppy disks, memory cards or sticks, etc.) and/or integrated memory devices (e.g., random access memory, flash memory, etc.).

Although certain methods, apparatus, and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. To the contrary, this patent covers all methods, apparatus, and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.

Claims

1. A method of adjusting nip rolls, comprising:

moving a web material between a first roll and a second roll opposite the first roll;

determining a pressure value associated with an amount of pressure applied to the web material by the first and second rolls; and

controlling the amount of pressure applied to the web material by moving one of the first and second rolls based on the pressure value.

2. A method as defined in claim 1, wherein determining the pressure value associated with the amount of pressure applied to the web material comprises:

obtaining measurement information from a load sensor; and

retrieving the pressure value based on the measurement information.

3. A method as defined in claim 2, wherein the measurement information is associated with at least one of a voltage value, a current value, an analog value, or a binary encoded value.

4. A method as defined in claim 1, wherein controlling the amount of pressure applied to the web material comprises:

comparing the pressure value to a threshold value; and

controlling an actuator based on the comparison of the pressure value to the threshold value.

5. A method as defined in claim 4, wherein the threshold value is associated with an operating range.

6. A method as defined in claim 4, wherein the threshold value is a maximum threshold pressure value or a minimum threshold pressure value.

7. A method as defined in claim 4, wherein the actuator is a stepper motor, a hydraulic cylinder, a pneumatic cylinder, or a solenoid.

8. A method as defined in claim 1, wherein moving one of the first and second rolls includes varying a distance by which the first and second rolls are separated.

9. A method as defined in claim 1, wherein controlling the amount of pressure applied to the web material includes maintaining a constant pressure.

10. A method as defined in claim 1, wherein the web material is a paper material, a plastic material, or a textile material.

11. A method as defined in claim 1, wherein the load sensor is a load cell.

12. A method as defined in claim 1, further comprising displaying the pressure value on a display.

13. A method of adjusting nip rolls, comprising:

applying a force to a web material via a radial surface of a roll;

obtaining measurement information from a load sensor operatively coupled to the roll and configured to monitor the force applied to the web material; and

changing the force applied to the web material by the radial surface based on the measurement information by translating the roll relative to the web material.

14. A method as defined in claim 13, wherein changing the force applied to the web material by the radial surface based on the measurement information comprises:

determining a measured force value based on the measurement information;

comparing the measured force value to a threshold value; and

changing the force applied to the web material based on the comparison of the measured force value and the threshold value.

15. A method as defined in claim 14, wherein the threshold value is associated with an operating range.

16. A method as defined in claim 14, wherein the threshold value is a maximum threshold pressure value or a minimum threshold pressure value.

17. A method as defined in claim 14, further comprising displaying the measured force value on a display.

18. A method as defined in claim 13, wherein changing the force applied to the web material includes controlling an actuator operatively coupled to the roll.

19. A method as defined in claim 18, wherein the actuator is a stepper motor, a hydraulic cylinder, a pneumatic cylinder, or a solenoid.

20. A method as defined in claim 13, wherein the load sensor is a load cell.

21. A method as defined in claim 13, wherein the measurement information is associated with at least one of a voltage value, a current value, an analog value, or a binary encoded value.

22. An apparatus for adjusting nip rolls, comprising:

a first roll having a first outer surface;

a second roll having a second outer surface located adjacent the first outer surface, wherein the first roll and the second roll are configured to receive a moving web material between the first and second outer surfaces;

a pressure sensor operatively coupled to the first roll and configured to generate an electrical signal based on a pressure applied to the moving web material by the first outer surface and the second outer surface; and

an actuator operatively coupled to the pressure sensor and configured to change the pressure applied to the moving web material based on the electrical signal by moving the first roll relative to the second roll.

23. An apparatus as defined in claim 22, further comprising a pressure meter communicatively coupled to the pressure sensor and configured to obtain the electrical signal from the pressure sensor and determine a measured pressure value associated with the pressure applied to the moving web.

24. An apparatus as defined in claim 23 further comprising a comparator communicatively coupled to the pressure meter and the actuator and configured to obtain the measured pressure value from the pressure meter and compare the measured pressure value to a threshold value and control the actuator based on the comparison.

25. An apparatus as defined in claim 24, wherein the threshold value is a maximum threshold value or a minimum threshold value.

26. An apparatus as defined in claim 22, wherein the actuator is a stepper motor, a hydraulic cylinder, a pneumatic cylinder, or a solenoid.

27. An apparatus as defined in claim 22, wherein the load sensor is a load cell.

28. An apparatus as defined in claim 22, wherein the electrical signal is associated with at least one of a voltage value, a current value, an analog value, or a binary encoded value