Vacuum timing device and method for producing the same

Information

  • Patent Grant
  • 6488194
  • Patent Number
    6,488,194
  • Date Filed
    Wednesday, August 30, 2000
    24 years ago
  • Date Issued
    Tuesday, December 3, 2002
    22 years ago
Abstract
A vacuum timing device for applying a vacuum on a roll includes a roll with an axis of rotation, a surface, and a surface longitudinal axis oriented in a direction substantially parallel to the axis of rotation. The device also includes at least one vacuum line running along at least a portion of the length of the roll. The device also includes a plurality of apertures defined in a surface of the roll and in fluid communication with the vacuum line. In order to alleviate angular delay of vacuum propagation, the plurality of apertures is arranged in a line that is skewed with respect to the surface longitudinal axis. Preferably, the plurality of apertures is arranged in a line that is skewed away from the direction of rotation of the roll, thereby substantially eliminating the angular propagation delay as the vacuum roll operates.
Description




FIELD OF THE INVENTION




The invention relates generally to vacuum assisted rolls, and more particularly to a vacuum timing device that compensates for the delay in vacuum propagation along the length of the roll.




BACKGROUND OF THE INVENTION




It is well known to utilize vacuum means to transfer webs from roll to roll or from a roll to another device such as a set of guide rods. The vacuum is selectively applied through apertures at selected circumferential locations on the rotating roll in order to hold a web of material to the roll for a desired time or along a desired path. As used herein and in the appended claims, the term “web” means any material (including without limitation paper, metal, plastic, rubber or synthetic material, fabric, etc.) which can be or is found in sheet form (including without limitation tissue, paper toweling, napkins, foils, wrapping paper, food wrap, woven and non-woven cloth or textiles, etc.). The term “web” does not indicate or imply any particular shape, size, length, width, or thickness of the material.





FIG. 1

illustrates a typical prior art vacuum roll system


10


for use in operations requiring web transfer. The prior art vacuum roll system


10


includes a roll


14


having an axis of rotation


18


and a surface


22


. The surface


22


has a plurality of apertures


26


therein which are spaced longitudinally along the length of the roll


14


forming a straight row


30


. Typically, there are a plurality of straight rows


30


(e.g., four rows spaced at ninety-degree angles), around the surface


22


. Each row


30


is in fluid communication with a vacuum line


34


. Normally, the vacuum line


34


is a bore that extends longitudinally along the length of the roll


14


just beneath the surface


22


. The apertures


26


are typically drilled through to the vacuum line


34


, thus providing the fluid communication between the apertures


26


and the line


34


. The line


34


has an vacuum inlet


38


in at least one end of the roll


14


, the purpose of which will be described below.




In prior art devices, a rotary vacuum valve


42


is usually coaxially coupled to the roll


14


at one end and is fixed against rotation. The valve


42


is connected to a vacuum source (not shown) at a valve inlet


50


. The valve


42


also includes an arcuate groove


54


in the end adjacent the roll


14


. The arcuate groove


54


is in fluid communication with the valve inlet


50


. The arcuate groove


54


is spaced radially from the axis of rotation


18


such that it can be in fluid communication with the line


34


. In operation, the vacuum source creates a vacuum that enters the valve


42


at the valve inlet


50


. As the roll


14


rotates to angular position A, the vacuum inlet


38


of the line


34


is adjacent the arcuate groove


54


. The vacuum therefore enters the vacuum inlet


38


and propagates longitudinally along the length of the line


34


. As the vacuum propagates, the apertures


26


experience the vacuum which is then applied to the web, holding the web to the surface


22


of the roll


14


. As the roll


14


rotates to angular position B, the fluid communication between the vacuum inlet


38


and the arcuate groove


54


is blocked, thereby cutting off the vacuum supply to the line


34


and apertures


26


. The line


34


is often vented in a conventional manner to remove the vacuum inside the line


34


quickly. By changing the length of arcuate groove


54


, the timing of vacuum application and removal can be modified to suit a specific application. The description of the prior art vacuum valve


42


is only presented by way of illustration. Other types of vacuum valves (not shown) are also commonly used in prior art vacuum roll systems


10


.




Surface speeds of the roll


14


typically vary depending upon application, but can reach 600 feet per minute or higher. Vacuum propagates through each line


34


at the speed of sound. Therefore, for long rolls


14


rotating at such high speeds, it is common to encounter angular delay in the propagation of the vacuum along the lines


34


. For example, when roll


14


reaches angular position A, and the vacuum is introduced into the vacuum inlet


38


, it is common in longer rolls


14


for the vacuum to reach the apertures


26


closest to the vacuum inlet


38


almost instantaneously while reaching the apertures


26


located farthest from the vacuum inlet


38


at a measurably later time. Often, the vacuum will not reach the apertures


26


located farthest from the vacuum inlet


38


until the roll has rotated to an angular position A+ΔA. When this angular delay occurs, the portion of the web (not shown) closest to the vacuum inlet


38


will experience the vacuum before the portion of the web farthest from the vacuum inlet


38


. This can cause binding, inadequate web retention, or misalignment of the web, resulting in flawed product, jams, misfeeds, wrinkling and/or even line shut-down.




Angular delay will also be experienced when vacuum is removed from the lines


34


. For example, when roll


14


reaches angular position B, and the communication between the vacuum inlet


38


and the arcuate groove


54


is blocked, it is common in longer rolls


14


for the vacuum to remain in the apertures


26


located farthest from the inlet opening longer than the vacuum remains in the apertures


26


located nearest to the vacuum inlet


38


. Thus, the vacuum will not be removed from the apertures


26


located farthest from the vacuum inlet


38


until the roll has rotated to an angular position B+ΔB. When this occurs, the portion of the web closest to the vacuum inlet


38


will be released from the surface


22


earlier than the portion of the web farthest from the vacuum inlet


38


. Again, this can cause the above-mentioned problems.

FIG. 2

shows an exaggerated profile of the angular delay just described. The profile illustrates the angular location of the apertures at the actual point of vacuum removal.




Attempts to alleviate the problem of angular delay have led to the use of two rotary vacuum valves


42


, one on each end of roll


14


. Each valve


42


has its own valve inlet


50


and arcuate groove


54


. Each arcuate groove


54


communicates with an adjacent vacuum inlet


38


at either end of the line


34


. This configuration has reduced angular delay problems associated with long rolls


14


in that the vacuum need only propagate half the length of the roll


14


. However, the high rotational speed demanded in many applications still results in angular delay near the center of the roll


14


. Furthermore, the use of two vacuum valves


42


adds more parts to the vacuum roll assembly


10


which increases the cost, complexity and maintenance required of the system.




In light of the problems and limitations of the prior art described above, a need exists for a vacuum timing device that can account and compensate for angular delay of vacuum in a rotating vacuum roll, can perform such compensation at a variety of roll rotational speeds, presents a simple and inexpensive solution to the angular delay problems described above and permits the use of a vacuum roll at high speeds without the angular delay experienced in prior art vacuum rolls. Each preferred embodiment of the present invention achieves one or more of these results.




SUMMARY OF THE INVENTION




The invention provides a vacuum timing device for applying a vacuum on a roll. The vacuum timing device includes a roll with an axis of rotation, a surface, and a surface longitudinal axis that is oriented in a direction substantially parallel to the axis of rotation. The device also includes at least one vacuum inlet communicating with at least one vacuum line running along at least a portion of the length of the roll. The device also includes a plurality of apertures defined in a surface of the roll and in fluid communication with the vacuum line. In order to alleviate angular delay of vacuum propagation, the plurality of apertures is arranged in a line that is skewed with respect to the surface longitudinal axis. Preferably, the plurality of apertures is arranged in a line that is skewed away from the direction of rotation of the roll, thereby substantially eliminating the angular propagation delay as the vacuum roll operates.




For longer rolls, the device can include two or more pluralities of apertures, each being in fluid communication with a respective vacuum line. Using two pluralities of apertures reduces the vacuum propagation distance, thereby reducing the propagation delay. When these long rolls operate at high speeds, however, delay often still exists. Therefore, each plurality of apertures is arranged in a line that is skewed with respect to the surface longitudinal axis to compensate for the remaining angular delay.




The pluralities of apertures can be formed directly in the surface of the roll, or alternatively, can be formed in one or more vacuum members that are coupled to the roll. Rolls having the apertures formed directly in the surface are preferable when the roll will rotate in the same direction and with substantially the same rotational speed over its lifetime. Once the direction of rotation and the rotational speed are known, the plurality of apertures can be machined directly into the surface with the appropriate skew. In the event the production line is changed and the direction or speed of rotation is modified, a different roll having a different skew configuration could be substituted, or portions of a roll could be replaced.




On the other hand, rolls that incorporate at least one vacuum member provide greater flexibility in that the vacuum member is preferably movable. The vacuum member can be selectively positioned to accommodate the direction of roll rotation and any number of rotational speeds. Most preferably, the vacuum member can be selectively positioned to accommodate both possible directions of roll rotation. The vacuum member can be moved with respect to the surface longitudinal axis either manually or automatically in any suitable manner. Preferably, the vacuum member is pivoted either about its end or a center portion of the vacuum member. When the vacuum member is moved automatically via a suitable actuating device, it is preferable to electronically (via computer or electronic switching controls) or mechanically link the actuating device to the roll to allow for automatic adjustment of the vacuum member proportional to the rotational speed of the roll. When more than one vacuum member is used, the vacuum members preferably operate in substantially the same manner.




When a vacuum member is used, the preferred configuration includes a roll having a longitudinal gap in the surface. The gap receives and accommodates at least a portion of the vacuum member. The plurality of apertures are preferably formed in a central portion of the vacuum member and communicate with the vacuum line in the roll. Preferably, the vacuum member also includes tab portions that extend from either side of the central portion. The tab portions are preferably received in respective grooves that are located radially in the roll. Preferably, the location of the grooves is such that when the vacuum member is inserted, the plurality of apertures in the central portion are at substantially the same radial distance from the axis of rotation as the surface. Alternatively, the location of the groove can be varied so that the plurality of apertures is slightly recessed or raised from the surface of the roll.




The grooves and gap are preferably appropriately sized to permit movement of the vacuum member relative to the roll. The vacuum member is preferably made from a flexible material so that as the vacuum member is pivoted it wraps partially around the roll, thereby skewing the plurality of apertures with respect to the surface longitudinal axis. The vacuum line should be large enough to accommodate preferably the entire range of movement available to the plurality of apertures. When more than one vacuum member is used, the vacuum members are preferably configured in substantially the same manner.




More information and a better understanding of the present invention can be achieved by reference to the following drawings and detailed description.











BRIEF DESCRIPTION OF THE DRAWINGS




The present invention is further described with reference to the accompanying drawings, which show a preferred embodiment of the present invention. However, it should be noted that the invention as disclosed in the accompanying drawings is illustrated by way of example only. The various elements and combinations of elements described below and illustrated in the drawings can be arranged and organized differently to result in embodiments which are still within the spirit and scope of the present invention.




In the drawings, wherein like reference numerals indicate like parts:





FIG. 1

is a perspective view of a prior art vacuum roll system;





FIG. 2

is a perspective view of a prior art vacuum roll illustrating an angular delay profile;





FIG. 3

is a perspective view of a vacuum roll according to a first preferred embodiment of the present invention;





FIG. 4

is an end view of the vacuum roll shown in

FIG. 3

;





FIG. 5

is a detail perspective view of the vacuum roll shown in

FIGS. 3 and 4

;





FIG. 6

is a perspective view of a vacuum roll having an alternative vacuum line configuration;





FIG. 7

is a perspective view of the vacuum roll and vacuum member shown in

FIGS. 3-5

, showing the vacuum member pivoted manually about the end of the vacuum roll;





FIG. 8

is a perspective view of the vacuum roll and vacuum member shown in

FIGS. 3-5

, showing the vacuum member pivoted manually about the central portion of the vacuum roll;





FIG. 9

is a perspective view of the vacuum roll and vacuum member shown in

FIGS. 3-5

, showing the vacuum member pivoted automatically about the end of the vacuum roll;





FIG. 10

is a perspective view of the vacuum roll and vacuum member shown in

FIGS. 3-5

, showing the vacuum member pivoted automatically about the central portion of the vacuum roll;





FIG. 11

is a perspective view of a vacuum roll according to a second preferred embodiment of the present invention in which the vacuum roll has two vacuum members;





FIG. 12

is a perspective view of a vacuum roll according to a third preferred embodiment of the present invention without a vacuum member; and





FIG. 13

is a perspective view of a vacuum roll according to a fourth preferred embodiment of the present invention without a vacuum member.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




The present invention can be used to reduce or alleviate angular delay of rotating vacuum systems and the problems associated therewith.

FIGS. 3

,


4


and


5


illustrate a vacuum roll system


100


of the present invention. It should be noted that the present invention is not limited only to web transfer operations, and can be used in conjunction with any operation in which vacuum or forced air is applied to a web material, such as in perforation, embossing, folding, cutoff or other types of rolls and for controlling actuation of blades, bars, inking or gluing devices, or virtually any other type of element or apparatus on a roll which is to be selectively operated or actuated by vacuum.




The vacuum roll system


100


includes a roll


114


having an axis of rotation


118


and a surface


122


. It should be noted that the surface


122


need not be smooth or homogenous, but rather can include raised portions, recessed portions, or can be comprised of a plurality of multiple surface elements (e.g., panels or plates coupled together to form the surface


122


). A vacuum member


126


is coupled to the roll


114


and includes a plurality of apertures


130


defined in the vacuum member


126


and extending therethrough. The apertures can be any shape desired, but are preferably round as shown in the figures. Preferably, the apertures


130


extend through a central portion


134


of the vacuum member


126


. As best seen in

FIGS. 4 and 5

, tab portions


138


preferably extend substantially perpendicularly from the central portion


134


giving the vacuum member


126


a T-shaped cross section about its X-axis. It is important to note that although such a vacuum member shape is preferred, the vacuum member


126


could be of any other cross-section or form suitable for allowing coupling of the vacuum member


126


to the roll


14


. For example, the vacuum member


126


could have an H-shaped cross-section about its Y-axis by including a second set of tab portions (not shown) closer to the plurality of apertures


130


. Alternatively, tab portions


138


could be replaced by intermittent dowels or other protrusions (not shown) extending from the vacuum member


126


into recesses, apertures, and the like in the roll


114


. The vacuum member


126


is preferably made of any suitably flexible material such as metal (insofar as the dimensions and length of the vacuum member


126


are concerned, many metals can be considered to be “flexible” for purposes of the present invention), plastic or rubber and can be formed by any suitable manufacturing process including but not limited to extrusion, injection molding or other machining processes.




As best seen in

FIG. 4

, the vacuum member


126


is preferably coupled to the roll


114


by inserting the tab portions


138


into opposite ends of a groove


142


depending from a longitudinal gap


146


in the roll


114


and sliding the first vacuum member


126


longitudinally along the length of groove


142


. Alternative configurations of the vacuum member


126


can necessitate alternative methods of coupling the vacuum member


126


to the roll


114


, which are not outside the scope of this invention, such as assembling the vacuum member


126


after insertion into the roll


114


, assembling parts of the roll


114


after insertion of the vacuum member


126


, etc. The longitudinal gap


146


preferably receives the central portion


134


of the vacuum member


126


. Groove


142


is preferably located at a distance below the surface


122


so that the plurality of apertures


130


are located at substantially the same radial distance from the axis of rotation


118


as the surface


122


. However, the groove


142


can be located such that the plurality of apertures


130


are recessed in, or raised from, the surface


122


. The width of the groove


142


and the longitudinal gap


146


is greater than the width of the tab portions


138


and the central portion


134


respectively, for reasons that will be explained below.




A vacuum line


150


is located radially below the groove


142


and in one preferred embodiment of the present invention (shown in

FIGS. 4 and 5

) intersects the groove such that the plurality of apertures


130


in the central portion


134


are in fluid communication with the vacuum line


150


. Preferably, the vacuum line


150


is defined by a bore or elongated chamber running longitudinally along the length of the roll


114


, but this need not be the case. As shown in

FIGS. 6-10

, the vacuum line


150


could instead be defined by a bore that does not intersect groove


142


, but rather runs along the roll at a radial distance below groove


142


and is in fluid communication with the groove


142


via a plurality of apertures running from the vacuum line


150


to each of the apertures


130


in the vacuum member. With particular reference to

FIG. 6

, these line openings


154


could be machined in the groove


142


such that the openings


154


correspond to the locations of the plurality of apertures


130


and provide fluid communication between the plurality of apertures


130


and the vacuum line


150


. Because the line openings


154


are larger than the apertures


130


in the preferred embodiment shown in

FIGS. 3-10

(and would not therefore be visible in the figures), the line openings


154


are shown in phantom while the plurality of apertures


130


are shown in solid lines. A vacuum inlet


158


is preferably located at one end of the vacuum line


150


.




In a less preferred embodiment of the present invention, the line openings


154


(if employed as described above) can be smaller than the plurality of apertures


130


. In such a case, the apertures


130


are preferably sufficiently large to maintain fluid communication with the openings


154


in the entire range of positions of the vacuum members


126


. For this purpose, the apertures


130


can have a larger diameter, can be elongated in shape (generally in a circumferential direction with respect to the roll surface


122


), and the like.




A rotary vacuum valve


162


is preferably coupled to the roll


114


at one end and shares the axis of rotation


118


, but is fixed against rotation. The rotary vacuum valve


162


is connected to a vacuum source (not shown) at the valve inlet


170


. The rotary vacuum valve


162


also includes an arcuate groove


174


in the end adjacent the roll


114


. The arcuate groove


174


is in fluid communication with the valve inlet


170


. The arcuate groove


174


is spaced radially from the axis of rotation


118


such that it can be in fluid communication with the vacuum inlet


158


and the vacuum line


150


. Once again, the rotary vacuum valve


162


is only one type of valve suitable for use with the preferred embodiment of the invention and is described and illustrated herein by way of example only. Other well-known valve assemblies, which may be located at different locations on the roll, can also be used.




In operation of the preferred embodiment described above, the vacuum source creates a vacuum that enters the rotary vacuum valve


162


at the valve inlet


170


. With reference to

FIG. 3

, as the roll


114


rotates to angular position A, the vacuum inlet


158


of the vacuum line


150


is in fluid communication with the arcuate groove


174


. The vacuum enters the vacuum inlet


158


and propagates longitudinally along the length of the vacuum line


150


. As the vacuum propagates, the plurality of apertures


130


experience the vacuum which is then applied to a web adjacent the roll


114


, thereby holding the web to the surface


122


of the roll


114


. As the roll


114


rotates through angular position B, the fluid communication between the vacuum inlet


158


and the arcuate groove


174


is blocked, and the vacuum line


150


is preferably vented in any conventional manner to remove the vacuum in the vacuum line


150


. By changing the angular length of arcuate groove


174


, the timing of vacuum application and removal can be modified to suit the specific application.




To address the problem of angular delay described earlier, the vacuum member


126


is movable, and more preferably is pivotable, with respect to the surface


122


of the roll


114


. For purposes of explanation, a surface longitudinal axis


178


is defined as an axis running longitudinally along the surface


122


of the roll


114


and oriented in a direction substantially parallel to the axis of rotation


118


. The surface longitudinal axis


178


preferably intersects an end or first aperture


182


of the plurality of apertures


130


, which is preferably the aperture closest to the vacuum inlet


158


. Note that the vacuum valve


162


is shown in

FIG. 3

on the right side of the roll


114


for purposes of illustration only. In

FIGS. 6-10

, the vacuum valve


162


(not shown) would instead be located on the left side of the roll


114


. The vacuum member


126


pivots with respect to the surface longitudinal axis


178


inside groove


142


and longitudinal gap


146


, which are wider than the tab portions


138


and central portion


134


respectively, to allow for such pivoting.




When the vacuum member


126


is pivoted, the plurality of apertures


130


are arranged in a line that is skewed with respect to the surface longitudinal axis


178


. As used herein and in the appended claims, the term “line” means a real or imaginary mark defining a shape or representing a contour. The term “line” does not indicate or imply any particular shape, contour, size, length, or width of the line defined by the arrangement of apertures


130


. For example, the term “line,” as used herein, includes both straight and curved arrangements of the apertures


130


. As used herein and in the appended claims, the term “skewed” means turned or placed at an angle, given a bias, or distorted. The term “skewed” does not indicate or imply any particular direction, amount or angle, and does not indicate or imply any consistency or lack of consistency in direction, amount or angle.




To state the configuration in other words, when the vacuum member


126


is pivoted from a position substantially parallel to the vacuum roll axis


118


, the line defined by the plurality of apertures


130


is not parallel to the surface longitudinal axis


178


. In yet other words, the vacuum member


126


includes the first aperture


182


and a second aperture


183


in fluid communication with the first aperture


182


. The fluid communication is established via the vacuum line


150


. When the vacuum member


126


is pivoted, the first and second apertures


182


,


183


define endpoints of a line that is skewed with respect to the surface longitudinal axis


178


. The vacuum member


126


can also include a third aperture


184


in fluid communication with the first and second apertures


182


,


183


as shown in the figures. When the vacuum member


126


is pivoted, the second and third apertures


183


,


184


define endpoints of a line that is also skewed with respect to the surface longitudinal axis. This line defined by the second and third apertures


183


,


184


can be aligned with the line defined by the first and second apertures


182


,


183


as is the case in the illustrated preferred embodiment, or can be skewed with respect thereto (where the plurality of apertures


130


are positioned on the vacuum member in a line that is not straight).




To compensate for angular delay in operation of the present invention, the vacuum member


126


is pivoted so that the line defined by the plurality of apertures


130


is skewed in a direction away from the direction of rotation of the roll


114


. As used herein and in the appended claims, the term “away from” means in a direction wherein the aperture closest to the vacuum inlet


158


leads at least one of the remaining plurality of apertures


130


as the roll


114


rotates. Simply stated, at least one aperture of the plurality of apertures


130


will be at the leading edge of rotation, while another aperture of the plurality of apertures


130


, which is further away from the vacuum inlet


158


, will trail the leading edge of rotation. In yet other words, the plurality of apertures


130


is skewed so that as the roll


114


rotates, at least one aperture that is further away from the vacuum inlet


158


lags behind at least one aperture that is closer to the vacuum inlet


158


. In the illustrated preferred embodiment, the roll


114


is capable of rotation in either direction and the vacuum member


126


can be pivoted, and therefore skewed, in either direction. To eliminate angular delay, however, the vacuum member


126


should be pivoted so that the line defined by the plurality of apertures


130


is skewed in a direction away from the direction of rotation.




The vacuum member


126


can be pivoted either manually or automatically, and can be pivoted about a number of possible pivot points. For example,

FIG. 7

shows a vacuum member


126


that is manually pivotable about a pivot point


185


located near one end of the roll


114


. It is important to note that pivot point


185


could be located near the opposite end of the roll


114


without deviating from the invention. The user can pivot he first vacuum member


126


relative to the surface longitudinal axis


178


in a direction and at a degree suitable for the direction of of rotation and speed of rotation demanded by the specific application. Securing element


186


is used to hold or lock the first vacuum member


126


in a selected pivot position. Securing element


186


can be any suitable device for fastening the vacuum member


126


into position on the roll


114


including, but not limited to, a screw, a set screw, a pin, a bolt, a clamp or any other conventional device capable of releasably securing one element to another. The securing element


186


is preferably located near the end of the roll


114


opposite the pivot point


185


, but can be located virtually anywhere along the vacuum member


126


.





FIG. 8

shows a vacuum member


126


that is manually pivotable about a pivot point


185


located at a central portion of the roll


114


. Again, the user can pivot the vacuum member


126


relative to the surface longitudinal axis


178


in a direction and at a degree suitable for the direction of rotation and speed of rotation demanded by the specific application. Securing elements


190


, preferably located near or at both ends of roll


114


are used to hold or lock the vacuum member


126


in the selected pivot position. Securing elements


190


can be any suitable device for fastening the vacuum member


126


into position on the roll


114


including, but not limited to, a screw, a set screw, a pin, a bolt, a clamp or any other conventional device capable of releasably securing one element to another, The securing elements


190


are preferably located near each end of the roll


114


, but can be located virtually anywhere along the vacuum member


126


. Furthermore, in either embodiment shown in

FIGS. 7 and 8

, any number of securing elements can be used as desired.




The embodiments illustrated in

FIGS. 9 and 10

are substantially the same as the embodiments illustrated in

FIGS. 7 and 8

with the exception that a vacuum member


126


is pivoted automatically using a positioning device


194


.

FIG. 9

illustrates the end-pivot configuration while

FIG. 10

illustrates the central portion-pivot configuration, both of which were described above with respect to

FIGS. 7 and 8

. The positioning device


194


can take the form of any device or mechanism suitable for pivoting the vacuum member


126


including, but not limited to, a cable, rack and pinion, levers and rods, electric motors, pneumatic cylinders, electromagnets or solenoids mounted upon the roll


114


or within a recess or receptacle in the roll


114


. For example, an electromagnet (not shown) could be placed on either side of the vacuum member


126


inside the roll


114


such that when energized, the vacuum member


126


would be attracted to, and pivot towards, the electromagnet. Alternatively, a plunger of an electric solenoid (not shown) could be used as the positioning device


194


to pivot the vacuum member


126


upon activation of the solenoid. The positioning device


194


also preferably holds the vacuum member


126


in the pivoted position until further adjustment is required. Furthermore, the positioning device


194


could be electronically or mechanically linked (via computer or electronic or manual switching controls) to the roll


114


to allow for automatic adjustment of the vacuum member


126


that is proportional to the rotational speed of the roll


114


.




Regardless of how pivoted, the vacuum member


126


is sufficiently flexible to wrap around the roll


114


as it pivots. This insures that the plurality of apertures


130


as well as the central portion


134


do not extend radially outward beyond the surface


122


enough to interrupt or affect vacuum applied to the apertures


130


. Furthermore, it is important that the vacuum line


150


be sized such that fluid communication will remain between the vacuum line


150


and each of the plurality of apertures


130


, regardless of the direction or degree of pivot. In other words, the vacuum line


150


must be designed to allow fluid communication with the plurality of apertures


130


over the entire range through which the apertures


130


can pivot. This can be achieved by designing the vacuum line


150


as a bore having a sufficiently large diameter, by designing the vacuum openings


154


with diameters sufficiently large to encompass the entire range of motion through which the corresponding apertures


130


can pivot, or by designing the apertures


130


with diameters sufficiently large to remain in fluid communication with the vacuum openings


154


throughout the range of motion of the apertures


130


. Care should be taken, however, that the vacuum line


150


and/or vacuum openings


154


do not permit vacuum leakage from the roll


114


during operation of the vacuum roll system


100


, regardless of the positioning of the vacuum member


126


.




It should be noted that the present invention as described above and illustrated in

FIGS. 1-10

employs one vacuum member at each circumferential position on the roll


114


. However, alternative embodiments of the present invention could employ two or more vacuum members in a similar manner. For example,

FIG. 11

illustrates an alternative vacuum roll system embodiment


200


of the invention that includes a roll


214


, an axis of rotation


218


and a roll surface


222


. The vacuum roll system


200


also includes the features described above with respect to the vacuum roll system embodiment


100


, but includes two vacuum members, a first vacuum member


226


and a second vacuum member


228


. The first and second vacuum members


226


,


228


are substantially identical (but can have slightly differing aperture arrangements, if desired) and operate in substantially the same manner described above with respect to vacuum member


126


. Like parts of the first vacuum member


226


are indicated by like reference numerals in the two-hundred series. This embodiment can be used in conjunction with long vacuum rolls


214


or in constructions with vacuum rolls


214


that operate very fast and/or with little tolerance for vacuum delay. In these situations, vacuum is typically (but not necessarily) supplied to both ends of the roll


214


.




The second vacuum member


228


includes a second plurality of apertures


232


and preferably includes the other features described above in conjunction with the vacuum member


126


. The first and second vacuum members


226


and


228


are preferably coupled to the roll


214


in the same way as described above with respect to vacuum member


126


. The groove


242


and longitudinal gap


246


can extend the entire length of the roll


214


and receive both the first and second vacuum members


226


and


228


. Alternatively, as shown in

FIG. 11

, first and second grooves


242


and


244


and first and second longitudinal gaps


246


and


248


can be incorporated in the roll


214


with the grooves


242


,


244


and gaps


246


,


248


being separated in the center of roll


214


. The roll


214


could even include more than two vacuum members (not shown) in line and mounted in one or more grooves and gaps with a vacuum valve (not shown) inside the roll to supply the interior vacuum members with vacuum.




First vacuum line


250


and/or first line openings


254


[(not visible in FIG.


11


)] can extend the entire length of the roll


214


to provide fluid communication to both the first and second plurality of apertures


230


and


232


. Alternatively, as shown in

FIG. 11

, first and second vacuum lines


250


and


252


and/or first and second line openings


254


and


256


can be incorporated in the roll


214


with the first and second lines


250


,


252


and first and second line openings


254


,


256


being separated in the center of the roll


214


. Regardless of whether a second vacuum line


252


is used, a second vacuum inlet


260


is located at the end of the roll


214


opposite the first vacuum inlet


258


.




With reference to the preferred embodiment shown in

FIG. 11

, a second rotary vacuum valve


264


is coupled to the roll


214


at the end opposite the first rotary vacuum valve


262


. Second rotary vacuum valve


264


preferably includes all of the other features described above in conjunction with first rotary vacuum valve


162


and is preferably oriented in mirror-image relation to the first rotary vacuum valve


262


. The second rotary vacuum valve


264


is connected to a vacuum source (not shown), or alternatively to a second vacuum source (also not shown), at the second valve inlet


260


. The second arcuate groove


276


is positioned for fluid communication with the second vacuum inlet


260


.




The operation of vacuum roll system


200


is substantially the same as described in relation to vacuum system


100


except that vacuum is supplied to both ends of roll


214


and propagates from both ends toward the center of roll


214


. To alleviate the problem of angular delay, both the first and second vacuum members


226


,


228


are movable, and preferably pivotable, with respect to the surface longitudinal axis


278


as described above in relation to the vacuum member


126


. The surface longitudinal axis


278


intersects the first or end aperture


282


of the first plurality of apertures


230


at one end of the roll


214


and also intersects a first or end aperture


284


of the second plurality of apertures


232


at the opposite end of the roll


214


. The first aperture


284


of the second plurality of apertures


232


is preferably the aperture closest to the second vacuum inlet


260


. The first vacuum member


226


can pivot such that the first plurality of apertures


230


is arranged in a line that is skewed with respect to the surface longitudinal axis


278


. Likewise, the second vacuum member


228


can pivot such that the second plurality of apertures


232


is arranged in a line that is skewed with respect to the surface longitudinal axis


278


.




To compensate for angular delay, both vacuum members


226


,


228


are pivoted so that the respective lines defined by the plurality of apertures


230


,


232


are skewed in a direction away from the direction of rotation of the roll


214


. The apertures nearest the center of the roll


214


will therefore lag behind the first apertures


282


,


284


.




The first and second vacuum members


226


,


228


can be pivoted either manually or automatically, and can be pivoted about a number of possible pivot points


285


as described above with respect to the vacuum member


126


. Automaiic pivoting of the first and second vacuum members


226


,


228


can be driven by a single positioning device


294


, or alternatively can be driven by first and second positioning devices


294


and


296


of the types described above.




In both vacuum roll system embodiments


100


,


200


, it is possible to have any number of vacuum members


126


,


226


and


228


positioned circumferentially around the rolls


114


,


214


at any spacing. In a highly preferred embodiment, the vacuum members


126


,


226


and


228


are positioned at ninety degree increments about the circumference of the roll


114


,


214


.




It should be noted that the present invention and appended claims describe a vacuum roll with one or more vacuum members, but could also be practiced without vacuum members. As seen in

FIG. 12

, vacuum roll system


300


illustrates yet another embodiment of the invention. With the exception of the vacuum member


126


and features associated therewith, the components and operation of the vacuum roll system


300


are preferably substantially the same as described above with respect to the vacuum roll system


100


of the first preferred embodiment, with like parts indicated by like reference numerals in the three-hundred series. If the direction of rotation and rotational speed for roll


314


are known and will remain substantially constant during normal operation of the vacuum roll system


300


, it is possible to eliminate the vacuum members and to locate the plurality of apertures


330


directly in the surface


322


of the roll


314


.




The surface longitudinal axis


378


runs longitudinally along the length of the roll


314


and is oriented in a direction substantially parallel to the axis of rotation


318


. The surface longitudinal axis


378


preferably intersects an end or first aperture


382


of the plurality of apertures


330


, which is preferably the aperture closest to the vacuum inlet


358


. The plurality of apertures


330


is arranged in a line that is skewed with respect to the surface longitudinal axis


378


. To compensate for angular delay, the plurality of apertures


330


is arranged in a line that is skewed away from the direction of rotation. The specific arrangement of apertures and manner and degree of skew is determined by the operating parameters under which the roll


314


will be used.




As an alternative to the single plurality of apertures


330


described above with reference to the third preferred embodiment of the present invention, the vacuum roll could have two or more pluralities of apertures at a circumferential position upon the vacuum roll. For example,

FIG. 13

illustrates an alternative vacuum roll system embodiment


400


of the invention that includes a roll


414


, an axis of rotation


418


and a surface


422


. A first and second plurality of apertures


430


and


432


are arranged in the surface


422


of the roll


414


. With the exception of the vacuum members


226


,


228


and the components associated therewith, the components and operation of the vacuum roll system


400


are preferably substantially the same as described above with respect to the vacuum roll system


200


of the second preferred embodiment. Like parts are indicated by like reference numerals in the four-hundred series. This embodiment can be used in conjunction with long vacuum rolls


414


or in conjunction with vacuum rolls


414


that operate very fast and/or with little tolerance for vacuum delay. In these situations, vacuum is typically (but not necessarily) supplied to both ends of the roll


414


.




The surface longitudinal axis


478


runs longitudinally along the length of the roll


414


and is oriented in a direction substantially parallel to the axis of rotation


418


. The surface longitudinal axis


478


intersects the first or end aperture


482


of the first plural of apertures


430


at one end of the roll


414


and also intersects a first or end aperture


484


of the second plurality of apertures


432


at the opposite end of the roll


414


. The first aperture


484


of the first plurality of apertures


430


is preferably the aperture closest to the first vacuum inlet


458


. The first aperture


484


of the second plurality of apertures


432


is preferably the aperture closest to the second vacuum inlet


460


. The first plurality of apertures


430


is arranged in a line that is skewed with respect to the surface longitudinal axis


478


. Likewise, the second plurality of apertures


432


is arranged in a line that is skewed with respect to the surface longitudinal axis


478


. To compensate for angular delay, both lines defined by the plurality of apertures


430


,


432


are skewed in a direction away from the direction of rotation of the roll


414


. The specific arrangement of apertures and manner and degree of skew is determined by the operating parameters under which the roll


414


will be used.




The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention as set forth in the appended claims. For example, the invention could be practiced to include a plurality of interchangeable plates or inserts having different arrangements of apertures therein. As such, it would be possible to use substantially longitudinally straight and rigid inserts having the proper arrangement of apertures to compensate for the angular delay of a particular application. If the application were to change, a different insert could be substituted on the roll. This would eliminate the need for pivoting the vacuum member and permits more flexibility than can be obtained by simply forming the apertures directly in the surface of the roll.




In another example, the first and second vacuum members can pivot in any conceivable manner such as about an element (e.g., a pin, hinge, post, etc.) or can be free-floating (e.g., held in position with magnets) in the groove and pivot with the help of the positioning device. Furthermore, it can be possible to use the vacuum itself as the positioning device such that application of the vacuum to the roll causes the vacuum members to pivot to the appropriate positions.



Claims
  • 1. A vacuum roll assembly comprising:a roll having an axis of rotation; a surface; and a surface longitudinal axis oriented in a direction substantially parallel to the axis of rotation; a vacuum inlet; a vacuum line in fluid communication with the vacuum inlet and running along the roll; a vacuum member coupled to the roll and movable with respect to the surface longitudinal axis; and a plurality of apertures defined in the vacuum member, in fluid communication with the vacuum line, and arranged in a line that is skewed with respect to the surface longitudinal axis.
  • 2. The apparatus of claim 1, wherein the roll has a direction of rotation and wherein the vacuum member is skewed away from the direction of rotation.
  • 3. The apparatus of claim 1, wherein the fluid communication between the vacuum inlet and the plurality of apertures is further provided by a rotary vacuum valve.
  • 4. The apparatus of claim 1, wherein the vacuum line is defined at least in part by an elongated chamber in fluid communication with each of the plurality of apertures.
  • 5. The apparatus of claim 1, wherein the vacuum line is defined at least in part by a plurality of openings, each of the plurality of openings being in fluid communication with a respective aperture.
  • 6. The apparatus of claim 1, wherein the vacuum member is pivotable with respect to the surface longitudinal axis.
  • 7. The apparatus of claim 6, wherein the vacuum member is flexible and wraps around the roll when pivoted with respect to the surface longitudinal axis.
  • 8. The apparatus of claim 6, wherein the vacuum member is pivoted manually.
  • 9. The apparatus of claim 6, the apparatus further comprising a positioning device coupled to the vacuum member and a control coupled to the positioning device, wherein the vacuum member is pivoted automatically responsive to roll speed by the positioning device under control of the control.
  • 10. The apparatus of claim 6, wherein the roll includes two opposing ends and the vacuum member pivots substantially about one of the opposing ends.
  • 11. The apparatus of claim 6, wherein the roll includes a center portion and the vacuum member pivots substantially about the center portion.
  • 12. The apparatus of claim 1, wherein the vacuum inlet is a first vacuum inlet, the vacuum line is a first vacuum line, the vacuum member is a first vacuum member, the plurality of holes is a first plurality of holes and the line is a first line, the apparatus further comprising:a second vacuum inlet; a second vacuum line in fluid communication with the second vacuum inlet and running along the roll; a second vacuum member coupled to the roll; and a second plurality of apertures defined in the second vacuum member, in fluid communication with the second vacuum line, and arranged in a second line skewed with respect to the surface longitudinal axis.
  • 13. The apparatus of claim 12, wherein the roll has a direction of rotation and wherein the second line is skewed away from the direction of rotation.
  • 14. The apparatus of claim 12, wherein the fluid communication between the second vacuum inlet and the second plurality of apertures is further provided by a rotary vacuum valve.
  • 15. The apparatus of claim 12, wherein the second vacuum line is defined at least in part by a plurality of openings, each of the plurality of openings being in fluid communication with a respective aperture of the second plurality of apertures.
  • 16. The apparatus of claim 12, wherein the second vacuum line is defined at least in part by a plurality of openings, each of the plurality of openings being in fluid communication with a respective aperture of the second plurality of apertures.
  • 17. The apparatus of claim 12, wherein the first and second vacuum members are movable with respect to the surface longitudinal axis.
  • 18. The apparatus of claim 12, wherein the first and second vacuum members are pivotable with respect to the surface longitudinal axis.
  • 19. The apparatus of claim 18, wherein the first and second vacuum members are flexible and wrap around the roll when pivoted with respect to the surface longitudinal axis.
  • 20. The apparatus of claim 18, wherein the first and second vacuum members are pivoted manually.
  • 21. The method of claim 18, the apparatus further comprising a first positioning device coupled to the first vacuum member and a first control coupled to the first positioning device, and a second positioning device coupled to the second vacuum member and a second control coupled to the second positioning device, wherein the first and second vacuum members are pivoted automatically responsive to roll speed by the first and second positioning devices, respectively, under control of the control.
  • 22. The apparatus of claim 18, wherein the roll includes two opposing ends, the first vacuum member pivots substantially about one end and the second vacuum member pivots substantially about the opposite end.
  • 23. The apparatus of claim 18, wherein each of the first and second vacuum members are pivotable about their centers.
  • 24. A method of producing a vacuum roll having an axis of rotation, a surface, and a surface longitudinal axis oriented in a direction substantially parallel to the axis of rotation, the method comprising the steps of:forming a first aperture in a vacuum member; forming a second aperture in the vacuum member; forming a vacuum line in the vacuum roll to establish fluid communication between the first and second apertures; coupling the vacuum member to the roll, the first and second apertures defining endpoints of a line that is skewed with respect to the surface longitudinal axis; and pivoting the vacuum member with respect to the surface longitudinal axis.
  • 25. The method of claim 24, wherein the roll has a direction of rotation and wherein the line is skewed away from the direction of rotation.
  • 26. The method of claim 24, wherein the vacuum member is skewed with respect to the surface longitudinal axis.
  • 27. The method of claim 24, wherein the roll has a direction of rotation and wherein the vacuum member is skewed away from the direction of rotation.
  • 28. The method of claim 24, wherein the line is a first line, the method further comprising the step of:forming a third aperture in the vacuum member, the third aperture being in fluid communication with the first and second apertures via the vacuum line, the second and third apertures defining endpoints of a second line that is skewed with respect to the first line and the surface longitudinal axis.
  • 29. The method of claim 24, wherein the step of pivoting the vacuum member includes wrapping the vacuum member around the roll.
  • 30. The method of claim 24, wherein the step of pivoting is completed manually.
  • 31. The method of claim 24, wherein the step of pivoting is completed automatically, and comprises:controlling a position of the vacuum member with a positioning device coupled to a control; and automatically changing the position of the vacuum member with the control and positioning device responsive to roll speed change.
  • 32. A vacuum roll assembly comprising:a roll having an axis of rotation; a surface; and a surface longitudinal axis oriented in a direction substantially parallel to the axis of rotation; a vacuum inlet; a vacuum line in fluid communication with the vacuum inlet and running along the roll; a vacuum member coupled to the roll; and a plurality of apertures defined in the vacuum member, in fluid communication with the vacuum line, and arranged in a line that is skewed with respect to the surface longitudinal axis, the plurality of apertures positioned with respect to the vacuum line to exert vacuum force only along a line skewed with respect to the surface longitudinal axis.
  • 33. The apparatus of claim 32, wherein the roll has a direction of rotation and wherein the vacuum member is skewed away from the direction of rotation.
  • 34. The apparatus of claim 32, wherein the fluid communication between the vacuum inlet and the plurality of apertures is further provided by a rotary vacuum valve.
  • 35. The apparatus of claim 32, wherein the vacuum line is defined at least in part by an elongated chamber in fluid communication with each of the plurality of apertures.
  • 36. The apparatus of claim 32, wherein the vacuum line is defined at least in part by a plurality of openings, each of the plurality of openings being in fluid communication with a respective aperture.
  • 37. The apparatus of claim 32, wherein the vacuum inlet is a first vacuum inlet, the vacuum line is a first vacuum line, the vacuum member is a first vacuum member, the plurality of apertures is a first plurality of apertures and the line is a first line, the apparatus further comprising:a second vacuum inlet; a second vacuum line in fluid communication with the second vacuum inlet and running along the roll; a second vacuum member coupled to the roll; and a second plurality of apertures defined in the second vacuum member, in fluid communication with the second vacuum line, and arranged in a second line skewed with respect to the surface longitudinal axis.
  • 38. The apparatus of claim 37, wherein the roll has a direction of rotation and wherein the second line is skewed away from the direction of rotation.
  • 39. The apparatus of claim 37, wherein the fluid communication between the second vacuum inlet and the second plurality of apertures is further provided by a rotary vacuum valve.
  • 40. The apparatus of claim 37, wherein the second vacuum line is defined at least in part by an elongated chamber in fluid communication with each of the second plurality of apertures.
  • 41. The apparatus of claim 37, wherein the second vacuum line is defined at least in part by a plurality of openings, each of the plurality of openings being in fluid communication with a respective aperture of the second plurality of apertures.
  • 42. The apparatus of claim 37, wherein the first and second vacuum members are movable with respect to the surface longitudinal axis.
  • 43. The apparatus of claim 37, wherein the first and second vacuum members are pivotable with respect to the surface longitudinal axis.
  • 44. The apparatus of claim 43, wherein the first and second vacuum members are flexible and wrap around the roll when pivoted with respect to the surface longitudinal axis.
  • 45. The apparatus of claim 43, wherein the first and second vacuum members are pivoted manually.
  • 46. The apparatus of claim 43, wherein the first and second vacuum members are pivoted automatically responsive to roll speed.
  • 47. The apparatus of claim 43, wherein the roll includes two opposing ends, the first vacuum member pivots substantially about one end and the second vacuum member pivots substantially about the opposite end.
  • 48. The apparatus of claim 43, wherein each of the first and second vacuum members are pivotable about their centers.
  • 49. A method of producing a vacuum roll having an axis of rotation, a surface, and a surface longitudinal axis oriented in a direction substantially parallel to the axis of rotation, the method comprising the steps of:forming a first aperture in a vacuum member; forming a second aperture in the vacuum member; forming a vacuum line in the vacuum roll to establish fluid communication between the first and second apertures; and coupling the vacuum member to the roll, the first and second apertures defining endpoints of a line that is skewed with respect to the surface longitudinal axis, the first and second apertures positioned with respect to the vacuum line to exert vacuum force only along the line that is skewed with respect to the surface longitudinal axis.
  • 50. The method of claim 49, wherein the roll has a direction of rotation and wherein the line is skewed away from the direction of rotation.
  • 51. The method of claim 49, wherein the vacuum member is skewed with respect to the surface longitudinal axis.
  • 52. The method of claim 49, wherein the roll has a direction of rotation and wherein the vacuum member is skewed away from the direction of rotation.
  • 53. The method of claim 49, wherein the line is a first line, the method further comprising the step of:forming a third aperture in the vacuum member, the third aperture being in fluid communication with the first and second apertures via the vacuum line, the second and third apertures defining endpoints of a second line that is skewed with respect to the first line and the surface longitudinal axis.
US Referenced Citations (33)
Number Name Date Kind
1053914 Hudson Feb 1913 A
2008402 Regan Jul 1935 A
2631846 Sabee Mar 1953 A
2929624 Brooker Mar 1960 A
3163413 Franke et al. Dec 1964 A
3172321 Schrader Mar 1965 A
3489406 Nystrand Jan 1970 A
3572681 Nystrand Mar 1971 A
3709077 Trogan et al. Jan 1973 A
3784188 De Ligt Jan 1974 A
3942788 Boyle Mar 1976 A
4070014 Takahashi Jan 1978 A
4159872 Klann Jul 1979 A
4254947 Trogan Mar 1981 A
4270744 Trogan Jun 1981 A
4328626 Leitner May 1982 A
4332583 Stemmler et al. Jun 1982 A
4396336 Malamood Aug 1983 A
4403847 Chrestensen Sep 1983 A
4406650 Felix Sep 1983 A
4475730 Trogan Oct 1984 A
4494741 Fischer et al. Jan 1985 A
4508527 Uno et al. Apr 1985 A
4650447 Meschi Mar 1987 A
4673382 Buck et al. Jun 1987 A
4770402 Couturier Sep 1988 A
4778441 Couturier Oct 1988 A
4909492 Biagiotti Mar 1990 A
4998715 Milan et al. Mar 1991 A
5114062 Kuhn et al. May 1992 A
5230456 Germann et al. Jul 1993 A
5358163 Naka Oct 1994 A
6250581 Cramer Jun 2001 B1
Non-Patent Literature Citations (1)
Entry
Webex, Inc. website: “Weber Vacuum Rolls” Jan. 17, 2000 http://www.webexinc. com/rolls/vacuum/vacuum.htm “Converting” Magazine, vol. 18, No. 1, Jan. 10, 2000 p. 74, “Vacuum Rolls for web control”.