SUCTION ROLLER WITH SENSORS TO DETECT OPERATING PARAMETERS

Abstract

An industrial roller comprising: a substantially cylindrical housing having an outer surface and an inner lumen; a polymeric cover circumferentially overlaid on the outer surface of the housing, wherein the housing and cover have a plurality of through-holes providing fluid communication between the lumen and the atmosphere; and a detection system; the detection system comprising: a plurality of sensors embedded in the cover, the sensors configured to detect an operating parameter of the roller and provide signals related to the operating parameter; at least one signal-carrying member connected with at least one of the sensors, wherein the signal-carrying member includes openings that align at least partially with some of the through-holes of the housing and cover; and a processor operatively associated with the sensors that processes signals provided by the sensors.

Description

SUCTION ROLLER WITH SENSORS TO DETECT OPERATING PARAMETERS RELATED APPLICATION This application claims priority from and the benefit of U.S. Provisional Patent Applications Nos. 62 / 049,600, filed September 12, 2014, and 62 / 168,362, filed May 29, 2015, the disclosures of which are incorporated herein in their entirety. FIELD OF INVENTION The present invention relates generally to industrial rollers, and more particularly to rollers for papermaking. BACKGROUND OF THE INVENTION Cylindrical rolls are used in many industrial applications, especially those related to papermaking. Such rolls are typically employed in demanding environments where they may be exposed to dynamic loads, high temperatures, and aggressive or corrosive chemical agents. For example, in a typical paper mill, the rolls are used not only to transport a sheet of fibrous mesh between processing stations, but also, in the case of the pressure section and calender rolls, for processing the same mesh sheet into paper. A papermaking machine may include one or more suction rolls positioned at various locations within the machine to capture moisture from a belt (such as a press felt) and / or the fiber web. Each suction roll is typically constructed from a metal housing covered by a polymer cover with a plurality of holes extending radially through it. Vacuum pressure is applied using a suction box located inside the suction roll housing. Water is captured in the radially extending holes and centrifugally expelled from the holes after passing out of the suction zone or is conveyed from inside the suction roll housing through appropriate fluid ducts or piping.The holes are typically formed in a grid pattern by a multi-bit drill that creates a line of multiple holes at once (for example, the drill can create fifty aligned holes at once). In many grid patterns, the holes are arranged so that the rows and columns of holes are at an oblique angle to the longitudinal axis of the roller. Since the paper web is conveyed through a papermaking machine, understanding the pressure profile experienced by the web is crucial. Pressure variations can impact the amount of water drained from the web, which in turn affects the moisture content, thickness, and other properties of the final sheet. The magnitude of pressure applied by a suction roll can therefore impact the quality of the paper produced by the papermaking machine. Other properties of a suction roll can also be important. For example, the stress and tension experienced by the roll cover in the weaving machine direction can provide information about the cover's durability and dimensional stability. Additionally, the roll's temperature profile can help identify potential problem areas on the cover. It is known that pressure and / or temperature sensors are incorporated into the cover of an industrial roller. For example, U.S. Patent No. 5,699,729 to Moschel et al. describes a roller with a helically arranged fiber that includes a plurality of pressure sensors embedded in the roller's polymer cover. However, a suction roller of the type described above presents technical challenges that a conventional roller does not. For example, suction roller hole patterns are typically designed with sufficient density so that some of the holes overlap portions of the sensors. Conventionally, the sensors and accompanying signal carrier (e.g., a fiber or cable) are applied to the metal housing before the polymer cover is applied, and the suction holes are drilled after the cover has been applied and cured.Thus, conventionally drilled holes in the cladding would almost certainly damage the sensors and could also damage the signal carrier. Furthermore, during cladding curing, the polymer material over the core often changes slightly, which in turn can alter the positions of the signal carrier and sensors. Therefore, it is not always possible to accurately determine the position of the signal carrier and sensors beneath the cladding, and the changing core can move a sensor or signal carrier directly under a hole. Additionally, optical fiber typically has a relatively high minimum bend radius for adequate performance. Therefore, if optical fiber is used as the signal carrier, attempting to interlace an optical fiber between prospective holes in the reel can result in unacceptable optical transmission within the fiber. An approach to using sensors on a suction roller is described in U.S. Patent No. 6,981,935 to Gustafson, which proposes that the signal carrier traces a path that follows the oblique angle of the suction roller drill pattern. This arrangement enables the signal carrier to be applied to the base layer of the roller cover before the application of the outer layer cover, while still preventing damage to the signal carrier during the drilling of the drain holes. In some embodiments, the sensor may be large enough not to fit within the spaces between the drain holes. In such cases, a blind drilled hole can be formed in the cover above the sensor instead of a through hole so that the hole pattern in the cover is not altered. However, this solution may not be optimal for all roller covers.One approach uses sensors with openings, with the drain holes aligned with the openings (see U.S. Patent No. 7,572,214 to Gustafson, the disclosure of which is incorporated herein in its entirety). Although this approach shows promise, modifications that improve the design may be desirable. BRIEF DESCRIPTION OF THE INVENTION As a first aspect, the embodiments of the invention relate to an industrial roller. The industrial roller comprises: a substantially cylindrical housing having an outer surface and an inner lumen; a polymer cover circumferentially superimposed on the outer surface of the housing, wherein the housing and cover have a plurality of through-holes providing fluid communication between the lumen and the atmosphere; and a detection system. The detection system comprises a plurality of sensors embedded in the cover, the sensors configured to detect an operating parameter of the roller and provide signals related to the operating parameter. At least one signal-carrying member is connected to at least one of the sensors, wherein the signal-carrying member includes openings that are at least partially aligned with some of the through-holes of the housing and cover.A processor that is operationally associated with the sensors processes signals provided by the sensors. As a second aspect, the embodiments of the invention relate to an industrial roller, comprising: a substantially cylindrical housing having an outer surface and an inner lumen; a polymer cover circumferentially superimposed on the outer surface of the housing, wherein the housing and cover have a plurality of through-holes providing fluid communication between the lumen and the atmosphere; and a detection system. The detection system comprises a plurality of sensors embedded in the cover, the sensors configured to detect an operating parameter of the roller and provide signals related to the operating parameter, wherein at least some of the sensors include an opening, and wherein some of the through-holes in the cover extend through the respective sensor openings.A plurality of centering members are inserted through the sensor openings and through-holes; each centering member has an internal bore that allows seamless communication between the lumen and the atmosphere. A processor operatively associated with the sensors processes the signals provided by them. As a third aspect, the embodiments of the invention are directed to an industrial roller, comprising: a substantially cylindrical housing having an outer surface and an inner lumen; a polymeric cover circumferentially superimposed on the outer surface of the housing, wherein the housing and cover have a plurality of through-holes providing fluid communication between the lumen and the atmosphere, the through-holes being arranged in a row and column arrangement; and a detector system.The detector system comprises a plurality of detectors embedded in the cover, the sensors configured to detect an operating parameter of the roller and provide signals related to the operating parameter, wherein at least some of the detectors include an opening, and wherein some of the through-holes in the cover extend through the respective openings of the detectors; a processor operatively associated with the detectors that processes signals provided by the sensors; and at least one signal-carrying member connected to at least one of the sensors, the signal-carrying member comprising a first segment that is routed between two columns of through-holes and a second segment that merges with the first segment that is routed between two rows of through-holes. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a scale view of a suction roller and detection system of the present invention. Figure 2 is a greatly enlarged view of a sensor within a suction roller hole pattern from Figure 1. Figure 3 is a scaled perspective view of a housing and an inner base layer formed in the manufacture of the suction roller of Figure 1. Figure 4 is a scaled perspective view of the casing and base layer of Figure 2 that is drilled. Figure 5 is a greatly enlarged perspective view of a sensor and its rivet for the suction roller of Figure 1. Figure 6 is an enlarged view of the two sensor cables from Figure 5 positioned on the cover base layer, with the sensor positioned to surround one of the marked circles formed in the marking procedure shown in Figure 4. Figure 7 is a scaled perspective view of the top supply layer being applied over the outer base layer of the suction roller in Figure 1. Figure 8 is a scaled perspective view of the upper supply layer qqo Lnn / zznz / E / YiAi of Figure 7 and the shell and inner and outer base layers of Figures 3 and 7 being drilled. Figure 9 is a scale view of a portion of a suction roller with a buttress in accordance with further embodiments of the invention. Figure 10 is a scaled view of the suction roller portion of Figure 9 with a sensor residing in the buttress. Figure 11 is a scaled view of the suction roller portion of Figure 9 with wires attached to the sensor. Figure 12 is a front view of an alignment pin that can be used in accordance with embodiments of the invention. Figure 13 is a top view of a mesh material used in electrical cables according to embodiments of the invention. Figure 14 is a top view of the mesh material from Figure 13 after processing. Figure 15 is a top view of a sensor and mesh cables as in Figure 14 within a hole pattern in accordance with modalities of the invention. DETAILED DESCRIPTION OF THE INVENTION The present invention will be described more particularly hereafter with reference to the accompanying drawings. The present invention is not intended to be limited to the illustrated embodiments; rather, these embodiments are intended to fully and completely describe the invention for those skilled in the art. In the drawings, equal numbers refer to identical elements throughout the description. The thicknesses and dimensions of some components may be exaggerated for clarity.Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which this invention pertains. The terminology used in the description of the invention herein is intended to describe particular embodiments only and is not intended to limit the invention. As used in the description of the invention and the appended claims, the singular forms "a" and "an" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.Where used, the terms joined, connected, interconnected, making contact, coupled, mounted and the like may mean joining or contact, whether direct or indirect, between elements, qqo Lnn / zznz / E / YiAi unless otherwise specified. With reference now to the figures, a suction roller, broadly designated by the number 20, is illustrated in Figure 1. The suction roller 20 includes a hollow cylindrical housing or core 22 (see Figure 3) and a cover 24 (typically formed of one or more polymeric materials) surrounding the housing 22. A sensing system 26 for detecting pressure, temperature, humidity, or some other operating parameter of interest includes a pair of electrical wires 28a, 28b and a plurality of sensors 30 (see Figures 2 and 6), each of which is embedded in the cover 24. As used herein, a sensor that is embedded in the cover means that the sensor is either contained entirely within the cover 24 or is mounted on the core 22 and completely covered by the cover 24. The sensing system 26 also includes a processor 32 that processes signals produced by the sensors 30. The housing 22 (Figure 3) is typically formed of a corrosion-resistant metallic material, such as stainless steel or bronze. A suction box (not shown) is typically positioned within the lumen of the housing 22 to apply negative pressure (i.e., suction) through the holes in the housing 22 and the cover 24. Typically, the housing 22 will already include through-holes that will then align with through-holes 82 in the cover 24. An exemplary housing and suction box combination is illustrated and described in U.S. Patent No. 6,358,370 to Huttunen, the disclosure of which is incorporated herein in its entirety. The cover 24 can take any shape and can be formed from any polymeric and / or elastomeric material recognized by those skilled in the art as suitable for use with a suction roller. Exemplary materials include natural rubber, synthetic rubbers such as neoprene, styrene-butadiene rubber (SBR), nitrile rubber, chlorosulfonated polyethylene (CSPE – also known by the trade name HYPALON), EPDM (the name given to an ethylene propylene terpolymer formed from ethylene-propylene diene monomer), epoxy, and polyurethane. In many cases, the cover 24 will comprise multiple layers. Figures 3 and 7 illustrate that an inner base layer 42a, an outer base layer 42b, and a top supply layer 70 are applied; additional layers, such as a tie layer between the base and top supply layers 42a, 42b, and 70, and an adhesive layer between the casing 22 and the inner base layer 42, may also be included.Cover 24 may also include reinforcing and filling materials, additives, and the like. Exemplary additional materials are discussed in U.S. Patents Nos. 6,328,681 to Stephens and 6,375,602 to Jones and U.S. Patent No. 6,981,935 to Gustafson, the disclosures of each of which are incorporated herein in their entirety. The cover 24 has a hole pattern (which includes through holes 82 and may also include blind punched holes) that can be any of the hole patterns conventionally employed with suction rollers or recognized as suitable for applying suction with an overlaid felt or papermaker's cloth and / or paper net as it travels over the roller 20. Typically, the holes are from about 0.15 to 0.64 centimeters in diameter and are spaced to be about 0.15 to 0.95 centimeters apart. A portion 86 of an exemplary hole pattern is illustrated in Figure 2. The portion 86 can be defined by a frame representing the height or circumferential expansion of the pattern (this dimension is typically about 1.27 to 3.81 centimeters) and a drill spacing that represents the width or axial expansion of the pattern (this dimension is typically approximately 2.54 to 7.62 centimeters). As is conventional, the columns of holes 82 define an oblique angle 0 (typically between approximately 5 and 20 degrees) with respect to a plane that is perpendicular to the longitudinal axis of the roller 20. With reference now to Figure 2, the sensor 30 shown therein has an internal opening 31 as described in Gustafson above, and also includes wings 33 for joining the electrical wires 28a, 28b. The sensors 30 can take any form recognized by those skilled in the art as suitable for detecting the operating parameter of interest (e.g., stress, strain, pressure, or temperature). Exemplary pressure sensors include piezoelectric sensors (particularly piezoelectric sensors formed from piezoelectric ceramics, such as a PZT-type lead titanate-zirgonate, quartz, synthetic quartz, tourmaline, gallium orthophosphate, CGG (Ca3Ga2Ge40i4), lithium niobate, lithium tantalite, Rochelle salt, and lithium sulfate monohydrate), force-resistant sensors, membrane sensors, and the like.The internal opening 31 was sized to be larger than an associated through-hole 82 in the cover 24; a typical dimension of the opening 31 is between approximately 0.2 and 1.27 centimeters. The external dimension of the sensor 30 was selected so that the sensor 30 did not overlap or extend into any of the surrounding through-holes 82; a typical external dimension of the sensor 30 was between approximately 0.32 and 0.76 centimeters. In the illustrated embodiment, the sensors 30 were annular, so the internal opening 31 was circular. However, other shapes of sensors and / or openings may also be suitable. For example, the sensor 30 itself could be square, rectangular, triangular, oval, hexagonal, octagonal, or similar, and the opening could also be any of these shapes.Alternatively, instead of the opening 31 being internal to the sensor 30 (i.e., the opening 31 having a closed perimeter), the opening 31 may be open-ended, so that the sensor 30 takes a U- or C-shape. The sensors 30 are distributed around the circumference of the roller 20 so that most of the sensors 30 are generally circumferentially equidistant from each other; one or more sensors 30 may be spaced differently for the purpose of determining the rotational position of the roller 20; see, for example, U.S. Patent No. 8,346,501, the disclosure of which is incorporated herein by reference in its entirety. qqo Lnn / zznz / E / YiAi The wings 33 of sensor 30 are formed so as to extend radially outward from the lower surface of the sensor body 30 and are substantially coplanar with each other; this configuration and its advantages are discussed in U.S. Patent No. 8,236,141, the disclosure of which is incorporated herein by reference in its entirety. As can be seen in Figure 2, each sensor 30 must be positioned so that its opening 31 is aligned with a through-hole 82 in the cover 24. To aid in positioning the sensor 30, a rivet 60 (shown in Figure 5) can be inserted through the opening 31 of the sensor 30, then into the underlying through-hole 82. Using the rivet 60, which is sized so that its shank diameter is slightly smaller than the diameter of the opening 31, can hold the sensor 30 in a position that allows the through-holes to be formed around it without damage. Once the rivet 60 is inserted through the sensor 30 and into the through-hole 82, a hole 62 is drilled in the center of the rivet 60 to reshape the through-hole 82. As discussed in U.S. Patent No. 6,981,935, in some earlier suction rollers that included sensing systems, the wires connecting the sensors to a processor were routed between drain holes (i.e., at the same angle Θ as the columns of the drain holes) to prevent damage to the wires during drain hole drilling. This configuration typically required the wires to form a helix with multiple turns or coils around the roller. A drawback of this approach is that the additional wire length required could reduce signal strength and accuracy and make the system more prone to damage or failure. An alternative cable routing approach is illustrated in Figure 6. In this approach, the sensors 30 themselves define a single helix coil along the length of the roller (much in the same manner as non-suction roller sensors: see, for example, U.S. Patent No. 8,346,501, the disclosure of which is incorporated herein in its entirety). The cables 28a, 28b are routed between the through-holes following a two-segment path between sensors, with the cables 28a, 28b following the angle θ between columns of through-holes 82 in a first segment, then passing between rows of through-holes 82 in a second segment that is substantially perpendicular to the pattern angle θ. As can be seen in Figure 6, the routing of cables 28a, 28b can be accomplished by identifying the through-hole 82 on which a sensor 30 is to be mounted, then placing alignment pins 90 into appropriate through-holes 82 that enable cables 28a, 28b to be routed between the rows and columns of through-holes 82. As can be seen in Figure 12, the alignment pins 90 may have a spring-loaded stem 92 with a slot 94 that can receive the cables during alignment. Although this cable arrangement 28a, 28b is longer than that of a non-suction roller with a single helical coil of sensors, the arrangement is much shorter than a multi-coil helix such as the one shown in Gustafson. With reference again to Figure 6, the cables 28a, 28b of the detector system 26 may be any signal-carrying member recognized by those skilled in the art as suitable for the passage of electrical signals in a suction roller. Alternatively, a wireless system, such as that described in U.S. Patent No. 7,392,715 to Moore, may be employed. With reference once again to Figure 1, the processor 32 is typically a personal computer or similar data-exchange device, such as a paper mill's distribution control system, that is operatively associated with the sensors 30 and can process signals from the sensors 30 into useful and easily understandable information. A wireless communication mode, such as RF signaling, is preferred for transmitting the data collected from the sensors 30 to the processing unit 32. Other alternative configurations include sliding ring connectors that enable signals to be transmitted from the sensors 30 to the processor 32. Suitable exemplary processing units are discussed in U.S. Patents Nos. 5,562,027 and 7,392,715 to Moore and 6,752,908 to Gustafson et al., disclosures of which are incorporated herein by reference in their entirety. The suction roller 20 can be manufactured as described below and illustrated in Figures 3 to 8. In this method, the housing 22 is initially covered with a portion of the cover 24 (as the inner base layer 42a). As can be seen in Figure 3, the inner base layer 42a can be applied using an extrusion nozzle 40, although it can also be applied by other techniques known to those skilled in the art. Typically, for a suction roller, the inner base layer 42a is made of rubber or epoxy-based composite materials. It will also be understood by those skilled in the art that, although the steps described below and illustrated in Figures 3 and 4 are shown to be performed on an inner base layer 42a, other internal layers of a cover 24 (such as the outer base layer 42b or a tie layer) can also serve as the underlying surface for the cables 28a, 28b and sensors 30. With reference now to Figure 4, the inner base layer 42a of the cover 24 is scored or otherwise marked, for example, with a multi-bit drill 46, with scoring marks 44 that correspond to a desired pattern of holes 82 that could eventually be formed in the roller 20. The scoring marks 44 should be deep enough to be visible to indicate the locations where the holes will eventually be formed, but need not be deeper. qqo Lnn / zznz / E / YiAi With reference to Figures 5 and 6, after the 44 marking marks are formed on the inner base layer 42a, the cables 28a, 28b, and sensors 30 of the sensor system 26 are installed. The locations of the sensors 30 are mapped along a designated path (typically a single wound helix). For each sensor 30, a nearest marking mark 44 is determined, and a hole is drilled there. Appropriate marking marks 44 are also located for the placement of alignment pins 90, which enable the cables 28a, 28b to be routed between sensors 30 between the columns and rows of the marking marks 44. Rivets 60 are inserted through the openings 31 of sensors 30, and then into the designated holes. Rivets 60 enable sensors 30 to remain substantially centered over the holes and clear of adjacent holes 82. In some embodiments, the rivets 60 are mounted using epoxy, which can protect the sensors 30 from water during papermaking. Once the rivet 60 and sensor 30 are mounted in the designated hole, a hole is drilled through the rivet 60 to serve as a through-hole 82. Cables 28a, 28b are mounted to the inner base 42a in any manner known to be suitable for such mounting. In some versions, cables 28a, 28b are sealed in place with varnish, with the solder joints between cables 28a, 28b and sensor wings 33 protected with epoxy. With reference to Figure 7, once the sensors 30 and cables 28a, 28b have been positioned and secured to the inner base layer 42a, the remainder of the cover 24 is applied. Figure 7 illustrates the application of the top supply layer 70 using an extrusion nozzle 72; a similar technique can be used to apply the outer base layer 42b over the inner base layer 42a. In some cases, either or both of the inner base layer 42a and the outer base layer 42b may be ground before the application of the next overlay layer. Those skilled in the art will appreciate that the application of the outer base layer 42b and the top supply layer 70 can be carried out by any technique recognized as suitable for such an application. On a typical suction roller, the outer base layer 42b is made of rubber or epoxy-based composite materials, and the top supply layer 70 is made of rubber or polyurethane.As noted, the present invention is intended to include rollers comprising only a base coat and a top coat, as well as rollers having covers with additional intermediate layers. The application of the top coat 70 is followed by curing, the techniques for which are well known to those skilled in the art and need not be described in detail herein. With reference to Figure 8, after the top supply layer 70 has cured, through-holes 82 and any blind drilled holes are formed in the cover 24, and, if through-holes 82 have not already formed in the housing 22, they are also formed therein. Through-holes 82 can be formed by any technique known to those skilled in the art, but preferably they are formed with a multi-bit drill 80 (an exemplary drill is the DRILLMATIC machine, available from Safop, Pordenone, Italy). In some embodiments, the through-holes 82 associated with the sensors 30 can be drilled by hand. It can be seen that the sensor modalities described above can overcome some of the problems presented by suction rollers. By including an opening in the sensor through which through-holes can be extended, the rollers of the present invention can avoid interfering with the hole patterns of the suction rollers and do not need to have blind drilled holes in positions above the sensors. The inclusion of rivets 60 can help center, and in turn protect, the sensors. 30. Furthermore, the two-segment path followed by the cables 28a, 28b between adjacent sensors 30 can shorten the overall signal path of the sensor data, thereby improving signal quality and performance. With reference now to Figures 9 to 11, a portion of a roller according to further embodiments of the invention, designated by number 120, is shown therein. In this roller 120, a buttress 184 is formed around the through-hole 182 in which a sensor 130 will reside (see Figure 9). The sensor 130 is reversed from its orientation in the roller 20, so that the body 130a of the sensor 130 is nestled within the buttress 184, and the wings 133 of the sensor 130 rest on the surface of the inner base layer 142a (see Figure 10). In this arrangement, the body 130a of the sensor 130 does not project above the surface of the inner base layer 142a, with the result that the outer base layer 142b may not require grinding after application. Also, the presence of buttress 184 eliminates the need for a rivet to center sensor 130 and hold its position. As can be seen in Figure 11, cables 128a and 128b can be attached to the wings 133 as discussed above. In the illustrated embodiment, cables 128a and 128b follow a three-segment spike-type path between the columns and rows of through-holes 182. Those skilled in the art will appreciate that the cables between the sensors can employ additional segments, as they are routed between the rows and columns of through-holes. It can also be seen that the columns and rows of holes need not be arranged along perpendicular axes; for example, the holes shown in Figures 9 to 11 are arranged on axes rotated approximately 60 degrees. Another technique for addressing the problem of cable arrangement and management can utilize a conductive mesh material, as illustrated in Figures 13 to 15, as the electrical cables 228 of the sensor system. The conductive mesh cables 228 can be applied to the roller and connected to the sensors as discussed above and as shown in Figure 15, where the cables 228 are attached to the wings 233 of a sensor 230. Because the mesh cables 228 are relatively wide in circumferential dimension (e.g., 1).27 qqo Lnn / zznz / E / YiAi centimeters) and extend between at least adjacent rows and / or columns of a roller through-hole array 282, the through-holes 282 can be formed through the wires 228, creating openings therein that are aligned with the through-holes 282; however, the width of the wires 228 enables the wires 228 to remain contiguous and thus maintain their electrical integrity. As such, the wires 228 need not be routed between the rows and columns of the suction holes 282, but can simply be placed on the roller in any desired arrangement as shown in the Figure. In some versions, 228 cables are formed as a tube that is then flattened before application to the roller. In some versions, 228 cables are made of a ductile metallic material, such as copper, nickel, copper-nickel alloys, silver, gold, or similar metals. In some versions, the mesh is a woven mesh formed from a single strand of wire. An exemplary mesh material for cables is MONEL®, available from Parker Chomerics (Woburn, Massachusetts). Before applying the mesh material to the roller, it can be processed to improve its electrical properties. For example, it can be immersion-soldered in a tin-lead solder bath or similar. This soldering procedure bonds the wire strands together, improving the electrical integrity of the mesh material. The sensors can be attached to the conductive mesh material by one or more of the following methods: soft soldering, welding, conductive epoxy, or conductive Z-axis tape. Other methods may be employed based on the current state of the art. Notably, the presence of openings or interstices in the mesh allows the epoxy or other material used to bond the roller cover to the core to pass through the mesh, thereby improving bonding and reducing the opportunity for delamination of the roller cover from the roller. The concept of expanded width for cables can also be applied to other potential cable materials. For example, the mesh material can be braided rather than woven. Alternatively, the cable can be a flat strip of some width (e.g., 0.01 to 0.03 centimeters thick and 1.27 centimeters wide) that includes perforations or other openings to allow the aforementioned epoxy to flow for bonding purposes. In some embodiments, the flat strip may lack perforations. In any of these variations, the expanded width cable maintains its electrical integrity even after through-holes from a suction roller are formed completely or partially through the cable. A width-to-thickness aspect ratio of at least 20:1 may be desirable. The foregoing is illustrative of the present invention and should not be construed as limiting it. Although embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications to the exemplary embodiments are possible without materially departing from the novel lessons and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalent claims to be included therein.

Claims

1. An industrial roller, comprising: a substantially cylindrical housing having an outer surface and an inner lumen; a polymeric cover circumferentially superimposed on the outer surface of the housing, wherein the housing and cover have a plurality of through-holes providing fluid communication between the lumen and the atmosphere; and a detection system comprising: a plurality of sensors embedded in the cover, the sensors configured to detect an operating parameter of the roller and provide signals related to the operating parameter, wherein at least some of the sensors include an opening, and wherein some of the through-holes of the cover extend through the respective openings of the sensors;A plurality of centering members is inserted through the sensor openings and through-holes; each centering member has an internal bore that allows smooth communication between the lumen and the atmosphere; and a processor operatively associated with the sensors processes signals provided by the sensors. 2.- The industrial roller according to claim 1, further characterized in that the openings are internal openings.

3. The industrial roller according to claim 2, further characterized in that the sensors are generally circular. 4 - The industrial roller according to claim 3, further characterized in that the sensors are made of a piezoelectric material.

5. The industrial roller according to claim 4, further characterized in that the detection system additionally comprises two electrical cables that interconnect each of the plurality of sensors.

6. The industrial roller according to claim 5, further characterized in that each of the electrical cables makes contact with a bottom surface of one of the sensors.

7. The industrial roller according to claim 5, further characterized in that each of the electrical cables makes contact with a bottom surface of one of the sensors.

8. The industrial roller according to claim 1, further characterized in that the sensor is configured to detect pressure.

9. The industrial roller according to claim 1, further characterized in that the cover includes a base layer circumferentially overlaying the housing and a top supply layer circumferentially overlaying the base layer, and wherein the sensors are embedded in the base layer.

10. The industrial roller according to claim 9, further characterized in that the base layer includes an inner base layer and an outer base layer, and wherein the sensors are arranged to overlap the inner base layer and place the outer base layer underneath.

11. The industrial roller according to claim 9, further characterized in that the base layer comprises rubber or an epoxy-based composite material.

12. The industrial roller according to claim 9, further characterized in that the upper supply layer is formed from a material selected from the group consisting of: rubber, polyurethane and epoxy compound.

13. An industrial roller, comprising: a substantially cylindrical housing having an outer surface and an inner lumen; a polymeric cover circumferentially superimposed on the outer surface of the housing, wherein the housing and cover have a plurality of through-holes providing fluid communication between the lumen and the atmosphere, the through-holes being arranged in a row and column arrangement; and a detection system comprising: a plurality of sensors embedded in the cover, the sensors configured to detect an operating parameter of the roller and provide signals related to the operating parameter, wherein at least some of the sensors include an opening, and wherein some of the through-holes of the cover extend through the respective openings of the sensors; a processor operatively associated with the sensors that processes signals provided by the sensors;and at least one signal-carrying member connected to at least one of the sensors, the signal-carrying member comprising a first segment that is routed between two columns of through holes and a second segment that merges with the first segment that is routed between two rows of through holes.; 14. The industrial roller according to claim 13, further characterized in that the at least one signal-carrying member is two electric cables.

15. The industrial roller according to claim 14, further characterized in that the electrical cables are routed between two of the plurality of sensors.

16. The industrial roller according to claim 13, further characterized in that the plurality of sensors is arranged as a single-coil helix along the length of the roller.

17. An industrial roller, comprising: a substantially cylindrical housing having an outer surface and an internal lumen; a polymeric cover circumferentially superimposed on the outer surface of the housing, wherein the housing and cover have a plurality of through-holes providing fluid communication between the lumen and the atmosphere; and a detection system comprising: a plurality of sensors embedded in the cover, the sensors configured to detect an operating parameter of the roller and provide signals related to the operating parameter, wherein at least some of the sensors include an opening, wherein some of the through-holes include a buttress, each of the sensors residing in a respective buttress, the through-holes of the cover extending through respective internal openings of the sensors;and a processor operationally associated with the sensors that processes signals provided by the sensors.

18. The industrial roller according to claim 17, further characterized in that the detection system additionally comprises at least two electrical cables interconnecting each of the plurality of sensors.

19. The industrial roller according to claim 18, further characterized in that each of the electrical cables makes contact with an upper surface of one of the sensors, the upper surface of the surface being on the opposite side of the buttress.

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