Field-replaceable composite roll system for corona treatment

Abstract

A Field-Replaceable Composite Roll system (FRCR) consists of a complex composite cover and a unique mechanical mounting system, configured to allow the retrofit of existing silicone sleeved rolls, as well as manufacture new rolls, at substantially lower costs. The system of the present invention can be used for retrofitting existing dead-shaft or live-shaft rolls previously manufactured to use silicone sleeves, as well as fabricating new rolls in conjunction with the patented WINERTIA® brand tubing or conventional thin-walled tubing. The exemplary embodiment of the composite cover is fabricated of a filament wound tube bound together via a resin or the like having dielectric properties, the tube forming inner and outer walls, the inner wall coated with a conductive layer for receiving and conducting an electric current, the outer wall coated with a wear resistant layer (illustrated as ceramic coating), followed by a sealant layer. The composite cover is configured to slide over and envelope a roller body, and be anchored in place via mechanical mount formed of first and second expansion rings and associated compression bases.

Description

REFERENCE TO EARLIER FILED APPLICATIONS

[0001] The present invention is a continuation-in-part of provisional patent application having serial No. 60/294,530, docket number ENCORE02/01, filed May 30, 2001.

FIELD OF THE INVENTION

[0002] The present invention relates to dielectric rollers for use in corona treatment applications, and in particular to a Field-Replaceable Composite Roll System for replacing a worn out dielectric roller sleeve or cover in the field, without the necessity of special procedures or tools. Present state-of-the-art in field replaceable rolls only include the use specially configured silicone sleeves comprising an elastic tube made of a silicone rubber compound. Performance compromises with the silicone sleeve include very poor resistance to abrasion and knife cut, short life, difficult replacement process, and a limitation in useable sizes. Other rollers require factory rebuild or simple replacement.

[0003] The preferred embodiment of the present invention contemplates a Field-Replaceable Composite Roll system (FRCR) consists of a complex composite cover and a unique mechanical mounting system, configured to allow the retrofit of existing silicone sleeved rolls, as well as manufacture new rolls, at substantially lower costs. Details for the design and manufacturing of the FRCR are described in this document to cover: (1) retrofitting existing dead-shaft or live-shaft rolls previously manufactured to use silicone sleeves, (2) designing new rolls using the patented WINERTIA® brand tubing, and (3) designing new rolls using conventional thin-walled tubing.

[0004] The exemplary embodiment of the composite cover is fabricated of a filament wound tube bound together via a resin or the like having dielectric properties, the tube forming inner and outer walls, the inner wall coated with a conductive layer for receiving and conducting an electric current, the outer wall coated with a wear resistant layer (illustrated as ceramic coating), followed by a sealant layer.

[0005] The composite cover is configured to slide over and envelope a roller body, and be anchored in place via mechanical mount formed of first and second expansion rings and associated compression bases.

BACKGROUND AND PRIOR ART

[0006] Dielectric rollers have been utilized for years in conjunction with corona treatment stations and the like, utilizing a variety of materials, including resin, ceramic, glass, silicone, and the like. Generally, the roller is covered with a dielectric compound to facilitate proper operation in the capacity of a roller electrode. In use, the corona field and resulting electrical discharge of current results in the emission of ozone and the creation of heat. The current emissions, ozone, and heat causes pitting and cracking of the treatment surface of the rollers over time, and eventually these rollers have to be replaced or repaired. Typically, the rollers must be removed from the treater stations, resulting in expensive machine down time. Silicone sleeves have been used as a protective, replaceable dielectric layer, which sleeves are replaceable in the field, but the sleeves are expensive, do not last long as other materials, and they are easily damaged.

[0007] Patents of relevance to the present system include:

[0008] U.S. Pat. No. 5,169,450 teaches a “Corona Treatment Roller Electrode” wherein there is taught a “self-supporting” tubular body having an inner conductive layer and outer dielectric layer, the tubular body supported via end plugs (12,13) at each of its ends. Thus, the interior of the '450 roller is hollow, the tube not configured to slip over existing rollers to provide an easy renewal of same, but rather it contemplates a specialized roller application utilizing special end caps not apparently compatible with third party roller designs.

[0009] EPO Patent 0 274 043 B1 teaches a roll electrode comprising a tubular electrode layer (4) having an insulated layer (5) apparently comprising a tube which is slipped thereover (FIGS. 3-5). Nonetheless, the patent does not appear to teach the concept of a replacement sleeve configured to slip over the body of an existing roller, coupled with a mounting mechanism configured to engage and retrofit existing rollers, as well as a specialized roller system for providing relatively easily accomplished refurbishing of electrode rollers on site.

GENERAL SUMMARY DISCUSSION OF THE INVENTION

[0010] Unlike the prior art, the present invention provides an effective system for on site replacement of worn portions of an electrode roller as used in corona field generator treatment stations which is quick, effective, and requires little training and no specialized tools or techniques.

[0011] The preferred embodiment of the present invention contemplates a Field-Replaceable Composite Roll (FRCR) system wherein there is provided a complex composite cover and a unique mechanical mounting system. The novelty in this invention is that is can be used to both retrofit existing silicone sleeved rolls, as well as providing off-the-shelf new rolls for use in new systems, at substantially lower costs than existing systems.

[0012] Details of the fabrication and operation of the FRCR are described in the present text to cover: 1) retrofitting existing dead-shaft or live-shaft rolls previously manufactured to use silicone sleeves, 2) providing new rolls utilizing the third party WINERTIA tubing, and 3) providing a new roller system utilizing conventional thin walled tubing.

[0013] The tube of the present invention configured to fit over existing rollers comprises a sleeve that consists of a filament wound tube to serve as a dielectric for corona treating, an innermost conductive layer for draining electrical current to earth ground, an outermost wear resistant layer constructed of ceramic, and a sealant coating to moisture proof the ceramic layer. Further, the wear resistant layer can be of a color with a sharp contrast to that of the filament wound tube to indicate wear.

[0014] A Mechanical Mounting System of the present invention for mounting the tube in place includes a preferred embodiment consisting of an Expansion Ring and a Compression Base. The Expansion Ring is used to apply an expansive and radially distributed force of friction uniformly on the Inside Diameter of the Complex Composite Cover to secure it without an invasive means. The Compression Base is used to apply a compressive and radially distributed force of friction uniformly on the Outside Diameter of a roll shaft to establish a concentric mount without an invasive means. Further, the Expansion Ring and the Compression Base utilize matching taper surfaces to convert perpendicular motion created by fasteners pulling the two pieces together to radial motion, which ultimately creates the force of friction such as described.

[0015] The Mechanical Mounting System can be used to retrofit any existing rollers, which were previously covered with a rubber, glass, epoxy, or ceramic compound, including the field-replaceable silicone tubing or sleeve. Further, the retrofit does not require establishing a new connection to earth ground as the existing ground connection is automatically extended to the conductive layer of the Complex Composite Cover.

[0016] Said Mechanical Mounting System and Complex Composite Cover can be quickly installed in the field without any special tooling or heavy labor. No force is required to install the system other than the normal force that is used to tighten small fasteners. Further, concentricity is automatically achieved between the roll to be retrofit and the new Complex Composite Cover.

[0017] An alternative embodiment of the present invention consists of an Adapter Ring and Complex Composite Cover can be combined with the patented Winertia® Idler Roll Technology to design new rolls for OEM's to have both technical innovation and lower production costs. The Adapter Ring requires simple machining operation to achieve the necessary dimensions for the design to work. Further, the Adapter Ring can be mass produced such as casting to further lower production cost. Innovative and cost cutting features include (1) quick field installation requiring no special tool (2) no machining required to the tube (3) enhanced cooling to lengthen the life of the dielectric (4) precise placement for thread inserts and installation fasteners by using the inclusive slots intended for balancing (5) universally adaptable for live or dead shaft designs (6) inclusive webbing can replace sensing points for the purpose of detecting roll motion (7) recommended recess in ends allows ready placement for the Adapter Ring.

[0018] Said Adapter Ring and Complex Composite Cover can be included in all conventional roll designs using standard ‘Drawn Over Mandrel’ tubing and achieve both technical innovation and low production costs as described above.

[0019] It is therefore an object of the present invention to provide an on-site composite roll conversion/retrofit system to facilitate quick replacement of worn dielectric roller covers.

[0020] It is another object to provide a dielectric roller system which may be incorporated into existing roller designs, or as a substitute for existing rollers in new units, wherein personnel may change out worn portions of said rollers on site without specialized tools or instruction.

[0021] Lastly, it is an object of the present invention to provide a dielectric roller system for corona treatment which costs less, is easier to maintain, and performs as well as or better than prior art systems.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1A is a side, cross-sectional view of the core forming the tube of the present invention.

[0023] FIG. 1B is and end view of the tube of FIG. 1A.

[0024] FIG. 1C is a side, close-up view of the invention of FIG. 1A, illustrating in detail the layers forming the tube of the present invention.

[0025] FIG. 2 is a side, partially cut-away view of the tube of FIG. 1A, illustrating the visual inspection of the interior of the tube.

[0026] FIG. 3 is a side, partially cut-away view of the tube core of FIG. 1, illustrating the application of a conductive layer to the interior of the tube core.

[0027] FIG. 4 is a side view of the first step of fabricating the tube core of FIG. 1, illustrating the application of a carbon veil strip to a mandrel mounted to a winder.

[0028] FIG. 5 illustrates the application of a ceramic layer to the outer surface of the tube core of FIG. 1.

[0029] FIG. 6 is an isometric view of the application of a sealant to the tube core of FIG. 1 using a vacuum pressure impregnation apparatus.

[0030] FIG. 7 is an end view of a first of two expansion rings utilized to support the first and second ends of the tube of FIG. 1, respectively.

[0031] FIG. 8A is an isometric view of the compression base for retrofitting a dead shaft roll.

[0032] FIG. 8B is an end view of the compression base of FIG. 8A. FIG. 9A is an isometric view of an alternative compression base for retrofitting a live shaft roll.

[0033] FIG. 9B is an end view of the compression base of FIG. 9A. FIG. 10A is a side, cross-sectional view of the mechanical mounting system of FIG. 10A is a side, cross-sectional view of the mechanical mounting system to retrofit existing rolls.

[0034] FIG. 10B is an end view of the invention of FIG. 10A.

[0035] FIG. 11A is a side, partially cut-away view illustrating the retrofit of a previously covered roll with the mechanical mounting system of the present invention.

[0036] FIG. 11B is an isometric view of the invention of FIG. 11A. FIG. 12 is a side, cut-away, cross-sectional view of the composite cover for field replacement of the present invention.

[0037] FIG. 13 is a side, isometric view of an alternative field replaceable composite roll system for OEM applications utilizing WINERTIA technology.

[0038] FIG. 14 is a side view of an adapter ring as used in the present invention for use in the present invention.

[0039] FIG. 15A illustrates an isometric view of an embodiment of the present invention wherein there is provided the mounting of the tube sleeve over an OEM roll.

[0040] FIG. 15B is a side, partially cross-sectional, partially cutaway view of the invention of FIG. 15A.

DETAILED DESCRIPTION OF THE INVENTION

[0041] Referring to FIGS. 1A-1C of the drawings, the preferred embodiment of the present invention comprises a tube T formed from a core member 8 having inner 1 and outer 3 walls and inner 2 and outer 4 diameters, respectfully, a thickness 5 therebetween, and first 6 and second 7 ends. As shown, the core member 8 is formed of composite materials having appropriate dielectric properties, a conductive layer 9 lining inner wall 2 of the core member, a wear resistant ceramic layer 10 applied over the outer wall 3 of the core member, and a sealant coat 11 encapsulating the ceramic layer, so as to seal any pores or the like formed in said ceramic layer. FIGS. 1A-1C show the basic construction of the tube, which can be manufactured to have any inside diameter (ID), outside diameter (OD) and length (Lg).

The Filament Wound Tube

[0042] Companies who specialize in filament winding of composite tubes for electrical applications can be used to manufacture the core member 8, which preferably is comprised of a filament wound tube. Accordingly, “core member” will refer to the filament wound tube, while “tube T” will refer to the core member which has been treated to provide an inner conductive layer, an outer ceramic coating, and a sealant. The core member serves as a mechanical body and a dielectric in the generation of corona. Corona generation by high voltage electricity is a process in which an electric field of thousands of volts is generated across a dielectric to create a sustainable electrical discharge to earth ground.

[0043] A generic filament wound tube designed to function as a corona treat roll (and core member in the present invention) must possess the proper properties including corona resistance, tensile strength, torsional strength, modulus of elasticity, dielectric strength, dielectric constant, volume resistivity, surface resistivity, power factor rating, electrical impulse rating, thermal dissipation factors, and temperature ratings. Specifically, a suitable epoxide system such as the ‘cyclo-aliphatic’ resin can be selectively formulated through successive and destructive electrical testings to optimize the desirable characteristics.

[0044] Invariably, all filament wound tube manufacturers have proprietary processes that are used to manufacture composite tubes for different segments of the market. In selecting a qualified manufacturer, the primary factors should include abilities to finish grind a precise and uniform wall thickness (concentricity), maintain the winding or hoop angles to achieve the proper resin to glass ratio, consistent wetting of the glass strands, thermal cure the tube in an oven equipped with rotisseries, and qualify a process to produce low to zero percent porosity.

[0045] Further, referring to FIG. 2, a visual inspection should be performed on each tube by shining a light source directed out ward from inside the tube to locate any air void that formed as a result of unwetted glass strands, poor porosity, etc. Tubes that show distinct opaque areas 14 of lines and spots, which may be detected by observation of the outside of the tube from the light source 13 within the tube, are strong suspects of being defective and should be rejected.

The Conductive Layer

[0046] Continuing with FIGS. 1A-1C and FIG. 3, the inner wall of the core member 8 is coated with a conductive layer for the purpose of draining electrical current safely to earth ground. This separate conductive layer 9 should adhere intimately with the inner wall 1 of the core member 8 forming the tube T and leave practically no air gap. Air gaps of any appreciable size and quantity could produce unwanted corona and possibly lead to localize heating and premature failures of the dielectric material forming the core member.

[0047] The simplest approach to fabricate the conductive layer is to ‘paint’ the inner wall of the core member with a special liquid via a foam applicator 16 or the like. This special liquid(s) exists commercially in the form of an air dry, conductive paint. Multiple coats that are a few mils in thickness will be needed to ensure complete coverage. Since conductive paints are available in several grades, it is imperative that a proper grade be selected based on its ability to adhere to fiberglass, and a surface resistivity rating equal to or less than 0.03 ohm/sq. in.

[0048] When applied directly to the inside surface of the tube, the low viscosity of the paint can be an advantage since it allows the paint to be worked into the uneven (on a microscopic scale) surface of the tube. In practice, this process is difficult and tiring when done manually since the applicator has to be placed on the end of a long pole and extended a few feet to reach the mid portions of the tube. Furthermore, the proven vacuum-pressure-impregnation (VPI) process must be carried out to minimize air entrapment.

[0049] Another viable approach to construct the conductive layer is to incorporate a layer of conductive material to form the inner wall of the core member during the construction of the core member, such as utilizing a suitable carbon veil. The veil, available in strip form, is placed by hand in a single layer 20 of conductive carbon strip spirally (via motor 23 rotating a mandrel 21) and temporarily held in place with tape 22. Neither overlapping of the carbon veil strip nor allowing any discernible amount of gap between 24 adjacent strips is acceptable. Doing so will produce an uneven dielectric wall thickness resulting in poor and inconsistent treat.

[0050] Once the carbon strip is tightly wrapped around the mandrel, the filament winding process is started right on top of the carbon veil to fabricate a core member of fiber glass and resin, utilizing standard filament winding techniques. Wetout of the veil with the same resin mix that is used for filament winding might be required to ensure good bonding. As compared with conductive paint, a composite cover constructed with carbon veil will have a strong and integral conductive layer that is highly resistant to any damage during handling. However, the integral carbon veil does pose some disadvantages including making inspection by a light virtually impossible since the black carbon blocks the light. Production can become an issue with the difficulty in hand laying the carbon strips, and extra work is needed to thoroughly clean the toolings and containers to avoid cross contamination of the resin with conductive residues from the carbon veil.

The Wear Resistant Ceramic Layer

[0051] Continuing with FIGS. 1A-C and FIG. 5, a ceramic outer layer 10 is used to provide a wear resistant jacket, as well as providing a visual cue for replacing the cover (when the ceramic cover is worn, the different color underlying outer wall of the core may be visually observed). Normal wear is due to mechanical abrasion and physical contact with the film or web, etching or stripping action of the corona, improper cleaning by scraping the roll with a hard edge, adverse chemical reactions with improper cleaning solutions, brittleness and surface cracks that develop due to high operating temperatures, and peeling due to interaction with slip agents used in the extrusion of films.

[0052] With the availability of a large selection of silica based products designed for a multitude of ceramic coating applications, and off the shelf ceramic coatings are available and are suitable. Key elements to optimize include proper surface preparation of the outer surface of the core member, a high temperature binder 25 for priming the surface to accept the ceramic coating, a ceramic powder coat suitable for spraying 26 via spray gun 27, number of coats and proper airpressure setting, thinning ratios and curing methods to avoid blistering and cracking. These key elements will ensure that the ceramic coating adheres well to the composite tube and hold up under harsh industrial conditions without flaking or breaking off.

The Sealant Coat

[0053] Referring to FIGS. 1A-1C and FIG. 6, the function of the sealant coat 11 is to encapsulate the ceramic coating 10 and make it moisture proof. Key elements in selecting a suitable sealant to use include corona resistance, operating temperature in excess of 425 dF, extremely thin bond lines, low viscosity (below 1000 cps), and a durable finish. Following proper curing of the ceramic coating, the sealant can be applied in a controlled room temperature environment. To ensure complete absorption of the sealant by the ceramic coating, the composite cover must be placed in a negative pressure chamber 30 that is capable of 26″ Hg or more. The negative pressure displaces any trapped air and moisture in the ceramic with the sealant. Several cycles of negative pressure followed by purging to a positive pressure will ensure thorough absorption, i.e., traditional Vacuum Pressure Impregnation (VPI) process.

The Mechanical Mounting System

[0054] Continuing with FIGS. 1A-1C and FIG. 7, a unique Mechanical Mounting System (MMS) is provided for mounting the tube to the roller, axle, or other support. The MMS is configured to provide: (1) a sound design specifically addressing the issues concerning corona treatment, (2) positive and secure mount for the composite cover, (3) ease for replacing the CCC in the field, (4) application robustness to include both the retrofit market and the OEM (Original Equipment Manufacturer) market. The design of the MMS as described in this invention is based on the fundamentals for engineering functional corona treat rolls. The design uses an expansion ring and a compression base.

Corona Treat Roll Fundamentals

[0055] The fundamentals for designing a successful treat roll are ensuring a consistent and minimal total indicator runout (TIR); maintaining concentricity between the shaft, the roll and the cover; and ensuring minimal deflection (commonly referred to as ‘whipping’) under high web load and high rotational speed. The MMS must meet these requirements whether it is used to: (1) retrofit an existing roll, (2) design a new roll using the patented Winertia® Idler Roll Technology, and (3) design a new roll that is more economical to produce using conventional thin-walled tubing.

The Expansion Ring

[0056] The composite makeup and tubular structure of the CCC require special provisions for capturing it in place. Conventional engineering practice such as drilling holes in the cover and using fasteners could lead to unnecessary sources for wear and tear; plus uneven pressures could lead to distortion and out of round conditions. Furthermore, good contact between the conductive layer and the roll must be maintained for electrical continuity. FIG. 7 shows an expansion ring design for capturing the composite cover without any of the described compromises.

[0057] Referring to FIGS. 1A-1C and FIG. 7, as the name implies, the expansion ring 35 comprises a disc body 36 forming an outer radial surface 37, and an inner radial opening 38 having emanating therefrom expansion slots 39 and an expansion split 40. As shown, the expansion ring is configured so that the outer radial surface 37 can be made to expand 41 (and thereby increase its outer diameter) so that its outer diameter may be made to engage the inner diameter 2 of the core member 8 or tube T, causing the two parts to become attached by the force of friction. Some means for creating and maintaining radial lines of force that point away from the roll center is necessary for the Expansion Ring to establish concentricity with the roll shaft as will be more fully disclosed herein.

The Compression Base

[0058] The working principle for a mounting base to complement the expansion ring has to work in both a retrofit application and in a new design. First and foremost, the base must be designed with special features to ensure self-centering concentrically with the shaft. Secondly, engaging and positioning the base on the shaft must not require excessive pressure, or force. Thirdly, the method for securing the base to the shaft must be noninvasive, i.e.; conventional setscrews if used will dig into the shaft and permanently scar it. FIGS. 8A, 8B and 9A, 9B show a mounting compression base design for a dead-shaft roll and a design for a live-shaft roll, respectively. Both designs take into account and satisfy all aforementioned issues.

[0059] As shown in FIGS. 1A-1C, FIG. 7, FIGS. 8A-8B, and FIGS. 9A-9B, the in use in a dead shaft roll incorporating a bearing, a bearing member 44 is provided comprising a mounting hub 50 having a passage formed therethrough having an inner diameter 44, a body 51 having the bearings situated therein, and an outer diameter 43 forming an engagement surface for engaging a compression base 49. As shown, the bearing member 42 is mounted to a shaft 47 by passing the inner diameter 44 about and along the shaft, so as to position 47′ the bearing member at the desired location on along shaft.

[0060] Upon positioning of the bearing member at the desired location of the shaft, a compression base 49 is mounted about the outer diameter 43 of the bearing member 42. The compression base 49 comprises a generally disc configured body having a passage 53 formed there through having an inner diameter 52 which is configured to engage the outer diameter 43 of the bearing member 42. As shown, the compression base includes an expansion split 54 as well as expansion slots 55 formed through the body to facilitate further opening or expansion of the inner passage 53 via mounting tools or the like for placement of the passage inner diameter about the outer diameter 43 of the bearing member.

[0061] Upon placement of the compression base about the bearing member, expansion pressure from the mounting tools may be relieved so as to allow the compression base to retract 48 to its unexpanded, lesser diameter configuration, so as to tighten about and securely engage bearing member 42. Alternatively the inner diameter 52 of the compression base may be configured to slidingly engage the outer diameter 43 of the bearing member, and upon the mounting and tightening of the expansion ring about the outer diameter of the compression base (which would be positioned about the bearing member), as will be described below, the compression base inner diameter would tighten about the bearing member, so as to affix said compression base and expansion ring in place about said bearing member.

[0062] As shown, the outer diameter 51 of the compression base 49 is laterally tapered from a more narrow diameter 45 to a wider diameter 46, to facilitate the expansion of an expansion ring thereabout as it is mounted about the outer diameter of the compression base, as will more fully be discussed infra.

[0063] FIGS. 9A and 9B illustrate the mounting of the compression base 49 directly about a shaft 47″, bypassing the bearings as in FIG. 8 above, as would be in a live shaft roll. As shown, the compression base is mounted directly to the shaft in this instance, with the shaft passing through the inner diameter 52 of the base. Expansion slot and expansion slits, as discussed above, can be utilized to expand the unit for mounting, or for facilitating contraction 48′ of the compression base about the shaft, either itself or in conjunction with the mounting of the expansion ring thereupon, as will be more fully discussed below.

System Design for the Retrofit Market

[0064] The present system can be made to retrofit existing third party rollers as the best dielectric covered roll, plasma sprayed ceramic, is expected to fail within five years. With the exception of rolls that were designed to be sleeved with silicone, all failed rolls (commonly called bonded dielectric) have to be sent back to the manufacturer for re-coating. It is not uncommon for users to put silicone sleeves on their failed bonded-dielectric rolls in order to avoid sending them back for re-coating.

[0065] Corona treat rolls are either of the ‘dead’ shaft or ‘live’ shaft design with a dielectric cover made of silicone sleeve, bonded silicone, bonded epoxy, bonded hypalon, bonded rubber or plasma-sprayed ceramic. A dead shaft does not rotate with the roll while a live shaft and its roll turn together in one piece. As touched upon above, in use, rolls with a dead shaft have the bearings supported by the non-rotating shaft, which is bolted to the chassis and prevented from turning. Rolls with a live shaft use ‘pillow block’ bearings that are supported by the chassis, and the shaft goes through the race of the bearings.

Working Principle of the Retrofit System

[0066] By combining the Expansion Ring design to capture the composite cover and the Compression Base design to anchor it to the existing roll assembly, it is feasible to upgrade any previously covered roll to the FRCC system.

[0067] FIGS. 10A and 10B illustrate the expansion ring 35 mounted about the compression base 49 (which base in turn is mounted about shaft 47′). As discussed above, the outer diameter 51 of the compression base 49 has formed thereon a tapered surface 65 from narrow 45 to wide 46 about its outer diameter; likewise, preferably, the expansion ring 35 may also have formed on its inner diameter 44 a complimentary tapered surface 56 from narrow 57 to wide 58 to engage the outer diameter tapered surface of the compression base.

[0068] Continuing with FIGS. 10A, 10B, and 11A, 11B, the expansion ring has first 59, second 60, and third 61, equidistantly spaced apertures configured to align with like first 62, second 63, and third 64 threaded apertures formed in the compression base. In mounting the expansion ring to the base, the tapered 65 outer diameter of the compression base 49 engages the tapered 56 expansion ring inner diameter in aligned fashion, and threaded fasteners or the like are passed through the expansion ring apertures 59, 60, 61 and into corresponding compression base apertures 62, 63, 64, so that the expansion ring is drawn about toward 66 and about the compression base, so that the tapered surfaces urge 67, 67′ the expansion ring outer diameter 43 to increase so as to contact and engage 67 the inner wall 1 of tube T (in phantom). While the above example illustrates the use of three apertures in each of the expansion ring and base, respectively, it is noted that additional apertures 68 may provide additional equalization of the pressure between the expansion ring and the base.

[0069] The above illustration of the mounting of a single base and expansion ring is to engage a first side of the tube, and the utilization of a second base and second expansion ring, mounted in like, opposing fashion for engaging the second end of the tube, would likewise have to be performed for positive mounting of the tube to the shaft.

[0070] As shown, the shaft may carry an existing roller R, and the tube T may be configured to envelope said roller, with the first 6 and second ends of the tube emanating from opposing sides of the roller, so as to allow the mounting of the compression base and expansion tube along the shaft on opposing ends of the roller, so as to support the opposing ends of the tube.

[0071] Of course, in such an application, the tube would be of a greater length than the roller which it is enveloping, so that the ends of the tube could emanate beyond the ends of the roller.

[0072] As indicated, the tapered inner diameter of the expansion ring effectively provides two diameters which effect the outer diameter of said ring, the first, unexpanded diameter which allows the outer diameter to be placed within the inner diameter of the sleeve, and the second, expanded outer diameter, created as a result of the expansion due to joining the compression base, which expanded diameter snugly and firmly engages the inner diameter and inner wall of the tube T.

[0073] Further, the joining 71 of the tapered surfaces of the expansion ring and compression base not only urge the expansion ring to expand 70, 70′ to engage the inner diameter of tube T, but it also urges the compression base to compress 73, 73′, resulting in a decrease of the internal diameter 52 of the passage 53 formed in the compression base, causing the compression base to clamp down upon the shaft 47 further, and anchoring same in place along the shaft.

[0074] Thusly with an off-the shelf, live shaft roll, once the dielectric layer of the roll has been worn out, instead of replacing or rebuilding the roll, one may retrofit the roll with the sleeve and hardware mount of the present system to convert the old roll into a system which allows the use of a field-replaceable sleeve or tube of the present invention.

[0075] In such a retrofit, the compression base may be positioned 74 along the shaft at the desired location where it is to be mounted, in conjunction with the expansion ring, to engage an end of the tube.

[0076] Also, as discussed above, with a dead shaft roll, as shown in FIGS. 8A, 8B, the compression base 49 is mounted to a bearing member 42 (as opposed to directly to the shaft), with the expansion ring 35 mounted to the compression base 49 as above, and caused to expand to engage the inner wall of the tube T as above via threaded fasteners urging the expansion ring and compression base's tapered surfaces toward one another, urging the outer diameter of the expansion base to engage the inner diameter of the tube. Put another way, by tightening the installation screws in a gradual and orderly fashion, the tapered surfaces are forced to slide tangentially in opposite directions. This creates a double action that has an opposite effect on the ring and the base. The ring expands inside the composite tube creating equal radial lines of force that cause the tube to grip the ring tighter and tighter. The reactive and radial lines of force on the base cause it to compress and grip tightly the OD of the shaft.

[0077] In tightening the expansion ring about the compression base, ideally, the base should start to compress first then force the ring to expand. This will ensure that the base, the ring and the composite tube establish concentricity around the shaft, which is solid and guaranteed to be ‘round’. Moreover, by reacting against the solid shaft, equally distributed radial lines of force are created.

[0078] Two sets of holes have been match drilled in the ring and the base: the above discussed set for installation, as well as an additional set to facilitate removal. As indicated, the apertures which are used for installation, have threads formed in the base. On the other hand, the holes that are used for removal have threads 73 formed in the ring, and no corresponding apertures in the base, so that threading the bolts 75 through the threaded apertures in the ring urges 76 the ring and base apart., as shown in FIG. 12.

[0079] FIG. 12 shows how the retrofit system can be quickly taken apart to allow fast and convenient field replacement of a worn out CCC. First, the installation screws are loosened and removed from the base. Two of the removed screws and are then threaded into the expansion ring. By tightening the screws, the ring and the base are quickly forced apart. The force against the base is reacted by the end of the roll and pushes the ring out from inside the composite cover. Again, this system does not necessitate the use of any force that could harm any part of the cover and roll assembly.

[0080] As iterated, the tube T must be manufactured to have a slip fit over the existing roll, which previously was covered by a dielectric of some kind. The slip fit is defined as not having to apply any force in order to slide the tube over the outer diameter of the existing roll while allowing the two parts to remain in physical contact. The slip fit is vital in that it allows easy field installation and removal of the composite cover and lets the rigidity of the existing roll be carried over to the tube. With regards to any additional deflection, the largest amount will be equal to the dimensional difference between the inner diameter of the tube and the outer diameter of the roll being retrofit.

System Design for the OEM Market

[0081] Innovation and price traditionally drive the OEM market. If innovation can bring to the market a better product and cut cost at the same time, it will have the support of both the manufacturer and the user. In the case of field-replaceable dielectric cover, the silicone sleeve is the most popular worldwide due to its replaceability. However, the silicone sleeve has little or no resistance to knife cuts, nicks and tear during normal handling. Price wise, it costs between $3.00 to $11.00 per inch depending on the diameter. Users typically pay $90.00 to as much as $1,100.00 apiece for their sleeves.

[0082] The system of the present invention delivers both innovation and low manufacturing cost in one package. The composite tube T of the present invention is extremely resistant to knife cuts, nicks and tear. The same operating principle as described for the retrofit system applies in the design of a new roll for OEM applications. A totally new concept in shown below by taking full advantage of a patented idler roll technology, which is trade marked under the name WINERTIA. Moreover, an alternate concept is also shown for the conventional thin-walled tubing, which is used in the manufacturing of OEM treat rolls. Referring to FIGS. 13 and 14, an alternative embodiment of the present invention, which has been designed for retrofitting a WINERTIA type roll, provides an Adapter Ring designed to fit in the recess at the ends of the Winertia® tube with a very thin section extending out. As shown, the prior art WINERTIA roller 86 comprises a first 87 and second 87′ core members supporting opposite ends of inner 90 and outer 91 tubes, the core members configured to provide air circulation through said inner and outer tubes for cooling and ventilating same.

[0083] The improvement of the present invention comprises a system for retrofitting the WINERTIA roller, providing a retrofit dielectric sleeve/tube over the outer tube 91, so as to envelope and extend beyond the ends of the WINERTIA roller 86, said retrofit dielectric sleeve/tube T fabricated in the manner discussed above in FIGS. 1A-1C, and 2-5, said retrofit dielectric sleeve/tube T mounted via specially configured adapter rings 79, 79′ at opposing ends of the roller, said adapter rings each comprising a mounting flange 80 configured to engage the end 94 of the tube T (which extend beyond the ends of the WINERTIA roller), the adapter ring 79 further comprising a first outer diameter member 81 having an outer diameter 95 configured to engage the inner diameter 97 of that portion of the tube T emanating 99 beyond the WINERTIA roller, the adapter ring 79 further comprising adjacent to said first outer diameter member 81 a second outer diameter member 82 having an outer diameter 96 configured to engage the inner diameter 98 of the outer tube 91 of the WINERTIA roller emanating 92 beyond the WINERTIA core member. In the present practice of the invention, the portion shown emanating 92 beyond the WINERTIA core member must be machined from the ends of the tube to form same, so as to fit the adapter ring 79 therein.

[0084] Formed in the mounting flange 80 of the adapter ring 79 are mounting apertures 83, 83′ configured to align with thread inserts 84, 84′ situated in the WINERTIA core members 87, 87′ both mounting apertures and respective thread inserts 84, 84′ configured to receive threaded fasteners 85, 85′, respectively for fastening the adapter ring to the WINERTIA roller, while supporting the tube T in place about same.

[0085] It is imperative that the roll be fabricated first to include shaft, recessed ends and thread inserts. It is iterated that first and second adapter rings are installed in opposing sides of the roll. The assembly may have to be lathed for final machining following installation of the tube T and adapter rings, so as to achieve concentricity.

[0086] It is iterated that the tube T must be manufactured with a precise ID to achieve a slip fit over the standard OD sizes of commercially available Winertia® tubing. The slip fit is defined as not having to apply any force in order to slide the tube T over the OD of the Winertia® tubing while allowing the two parts to remain in physical contact. The slip fit is vital in that it allows easy field installation and removal of the composite cover and lets the rigidity of the Winertia® tubing be carried over to the CCC. With regards to additional deflection, the largest amount will be equal to the dimensional difference between the ID of the CCC and the OD of the Winertia® tubing.

FRCR/Conventional Tubing Roll Design

[0087] The technology for building treat rolls using a conventional (steel or aluminum) thin-walled tubing instead of the Winertia® tubing has some significant advantages such as the abundant and low cost DOM (Drawn Over Mandrel) tubing; the availability of matured businesses competing for a well-known product thus lowering the cost; and the overall familiarity with the manufacturing process. The invention of the present system is easily and readily adaptable to the design and manufacturing of corona treat rolls using DOM tubing. FIG. 15A shows a roll design for OEM applications.

[0088] FIG. 15A shows a typically constructed live-shaft roll on top to depict how readily this conventional design can be retrofitted for the system of the present invention, which is shown in FIG. 15B. As depicted in FIGS. 15A and 15B, the conventional live-shaft roll consists of first 100 and second 100′ plugs engaging the inner diameter 103 of the DOM tubing 102, the first and second plugs engaging two short shafts 101, 101′, respectively (or a single long shaft). The plugs and the shafts are designed to have an interference fit with the tubing to allow them to be heat shrunk permanently in place.

[0089] To convert the conventional roll design to the present system, first 104 and second 104′ Adapter Rings are configured to attach to respective end plugs 100, 100′. The plugs are recessed a few inches inside the roll to minimize any tendency by the roll to ‘whip’ (technically defined as deflection) at high web load and high rotational speed. The recess also allows room for the new adapter rings to engage the end plugs, as well as the inner diameter of the OEM tube.

[0090] Like the adapter rings of FIG. 14, the adapter ring of the present application has a mounting flange 105 to engage the ends 108, 108′ of the tube T, a first OD member 106 having an outer diameter to engage the a inner diameter of the tube T, and may further include a second OD member 103 having an outer diameter to engage the inner diameter of the DOM tubing 102 emanating past plugs 100, 100′, the tube T of the present invention comprising the composite dielectric tube T discussed in FIGS. 1A-1C, and 2-5, said tube T having an inner diameter to allow it to slip over while contacting the outer diameter of the DOM tubing 102, and a length to emanate beyond both ends of the DOM tubing.

[0091] The Adapter Rings are similar in design to the one used for the Winertia® tubing OEM design discussed above. One adapter ring can be permanently fastened or welded to the roll. Another variation of the adapter ring is match drilled to the plug with two sets of holes for installing and removing the composite cover.

[0092] The machining process is similar as well for the critical dimensions OD1, OD2, OD3 and F as shown in FIG. 14. It is important to note that the cost saving is in the machining time, which can be cut in half since the finish of the roll is no longer critical. Specifically, the composite cover eliminates the need to have a fine finish on the DOM tubing for the purpose of covering it with a bonded dielectric. Moreover, the adapter rings can be produced in mass by casting to minimize the additional cost of adding them to the final OEM treat roll products.

[0093] In summary, the method of servicing a corona roller having a shaft and a roller body having an outer diameter, a length, and first and second ends, may be summarized as follows::

[0094] a. providing a sleeve of dielectric material, said sleeve having an inner diameter sufficient to enable said sleeve to slide over the outer diameter of the cylindrical body of the roller, while allowing the inner wall of said sleeve to engage the outer diameter of said cylindrical body;

[0095] b. slidingly positioning said sleeve over said roller body such that said length of said sleeve envelopes the cylindrical body of the roller, while allowing first and second ends of said sleeve to extend beyond the first and second ends of said cylindrical body of said roller, so as to provide first and second free ends of said sleeve emanating beyond the first and second ends of the cylindrical body of said roller;

[0096] c. applying a first mechanical mount to said first free end of said sleeve emanating beyond the first end of the cylindrical body of said roller so as to anchor said first end of said sleeve to said roller;

[0097] d. applying a second mechanical mount to second free end of said sleeve emanating beyond the second end of the cylindrical body of said roller so as to anchor said second end of said sleeve to said roller;

[0098] e. allowing said sleeve to function as a dielectric roller, while protecting the cylindrical body of said roller.

[0099] The invention embodiments herein described are done so in detail for exemplary purposes only, and may be subject to many different variations in design, structure, application and operation methodology. Thus, the detailed disclosures therein should be interpreted in an illustrative, exemplary manner, and not in a limited sense.

[0100] Elements of the Invention

[0101] Title: Field-Replaceable Composite Roll System for Corona Treatment

[0102] Inventor: Pham 1 T Tube 1 inner wall  2 inner diameter  3 outer wall  4 outer diameter  5 thickness  6 first  7 second ends  8 core member  9 conductive layer 10 ceramic layer 11 sealant coat 12 passage 13 light source 14 opaque area 15 paint 16 spray head 17 hose 18 19 20 carbon veil strip 21 mandril 22 tape anchor 23 motor 24 continuous layer 25 binder 26 spraying 27 spray gun 28 29 30 vacuum chamber 31 core member 32 sealant 33 vacuum pump 34 35 expansion ring 36 disc body 37 outer radial surface 38 inner radial opening 39 expansion slots 40 expansion split 41 expand 42 bearing member 43 outer diameter 44 inner diameter 45 taper narrow 46 wide 47 shaft  47′ applied 48 retract 49 compression base 50 mounting hub 50 body 51 outer diameter - compression 52 inner diameter - compress 53 passage 54 expansion slit - compres 55 expansion slots compress 56 expansion ring taper 57 narrow 58 wide 59 expansion ring threaded aperture 60 ″ 61 ″ 62 compression base apertures 63 ″ 64 ″ 65 compression base taper 66 toward 67 engage 68 aperture 69 70 expansion R Roller 71 joining 72 of the expansion base 73 threads in ring 74 positioned 75 threaded fasteners 76 urges 77 78 79 Adapter Ring 80 Mounting flange 81 First OD member 82 Second OD member 83 Mounting apertures 84 Thread inserts 85 Threaded fasteners 86 Winertia roller 87 Winertia core member 88 sleeve 89 shaft 90 inner tube 91 outer tube 92 emanates 93 iD 94 end 95 OD 96 OD 97 ID 98 ID 99 Emanating 100 Plugs 101 Shafts 102 DOM tubing 103 ID 104 Adapter rings 105 Flange 106 First OD member 107 Second OD member 108 Ends of tube T

Claims

1). A corona electrode roller system for use with a roller having a cylindrical body having first and second ends, a length and an outer diameter, and a shaft longitudinally emanating therefrom, comprising:

a sleeve of dielectric material having a conductive inner wall, said sleeve having an inner diameter sufficient to enable said sleeve to slide over the outer diameter of the cylindrical body of the roller, while allowing the conductive inner wall of said sleeve to engage the outer diameter of said cylindrical body, said sleeve having a length to envelope the cylindrical body of the roller, while allowing said first and second ends of said sleeve to extend beyond the first and second ends of said cylindrical body of said roller when said sleeve is slipped over said cylindrical body of said roller, so as to provide first and second free ends of said sleeve emanating beyond the first and second ends of the cylindrical body of said roller;

first and second mechanical mounts for engaging said first and second free ends of said sleeve, and anchoring said first and second free ends to the roller, each of said first and second mechanical mounts further comprising:

a compression base having a central passage formed therethrough for receiving the shaft of the roller, said compression base having an outer diameter which is laterally tapered from a lesser outer diameter to a greater outer diameter;

a generally disc shaped expansion ring, said expansion ring having formed therethrough a passage having an inner diameter formed to engage the outer diameter of said compression base;

wherein tightening the engagement of said expansion ring to said compression base increases the outer diameter of said expansion ring to engage the inner diameter of said sleeve, while decreasing the inner diameter of the passage formed in said compression base, to tighten said compression base about said shaft.

2) The corona electrode roller system of claim 1, wherein said tube is formed of a conductive layer of carbon veil strip having laminated thereon a layer of filament winding bound together by resin.

3) The corona electrode system of claim 2, wherein the outer diameter of said sleeve has applied thereon a ceramic outer coating.

4) The coronal electrode system of claim 3, wherein said ceramic outer coating is a different color than the underlying filament winding and resin, so that the wearing through of said ceramic outer coating results in an observable color change.

5) The corona electrode system of claim 4, wherein there is applied to said ceramic outer coating a clear sealant.

6) The corona electrode system of claim 5, wherein the inner diameter of said passage formed through said expansion ring is tapered from a lesser inner diameter to a greater inner diameter, so as to facilitate compression of said compression base, as well as expansion of said outer diameter of said expansion ring, upon tightening of said compression base to said expansion ring.

7) The method of servicing a corona roller having a shaft and a roller body having an outer diameter, a length, and first and second ends, comprising the steps of:

a. providing a sleeve of dielectric material, said sleeve having an inner diameter sufficient to enable said sleeve to slide over the outer diameter of the cylindrical body of the roller, while allowing the inner wall of said sleeve to engage the outer diameter of said cylindrical body;

b. slidingly positioning said sleeve over said roller body such that said length of said sleeve envelopes the cylindrical body of the roller, while allowing first and second ends of said sleeve to extend beyond the first and second ends of said cylindrical body of said roller, so as to provide first and second free ends of said sleeve emanating beyond the first and second ends of the cylindrical body of said roller;

c. applying a first mechanical mount to said first free end of said sleeve emanating beyond the first end of the cylindrical body of said roller so as to anchor said first end of said sleeve to said roller;

d. applying a second mechanical mount to second free end of said sleeve emanating beyond the second end of the cylindrical body of said roller so as to anchor said second end of said sleeve to said roller;

e. allowing said sleeve to function as a dielectric roller, while protecting the cylindrical body of said roller.

8. The method of claim 7, wherein said first and second mechanical mounts each comprise:

a compression base having a central passage formed therethrough for receiving the shaft of the roller, said compression base having an outer diameter which is laterally tapered from a lesser outer diameter to a greater outer diameter;

a generally disc shaped expansion ring, said expansion ring having formed therethrough a passage having an inner diameter formed to engage the outer diameter of said compression base;

and wherein in step “c” and “d” the step of applying said first and second mechanical mounts further comprises the steps of:

i. placing a first compression base about said shaft in the vicinity of the first end of said sleeve, and applying and tightening a first expansion ring to said to said first compression base so as to increase the outer diameter of said expansion ring to engage the inner diameter of said first end of said sleeve, while decreasing the inner diameter of the passage formed in said first compression base, so as to tighten said compression base about said shaft and anchor said first end of said sleeve in place; and

ii. placing a second compression base about said shaft in the vicinity of the second end of said sleeve, and applying and tightening a second expansion ring to said to said second compression base so as to increase the outer diameter of said expansion ring to engage the inner diameter of said second end of said sleeve, while decreasing the inner diameter of the passage formed in said second compression base, so as to tighten said compression base about said shaft and anchor said second end of said sleeve in place

9) The method of claim 7, wherein said first and second mechanical mounts each comprise:

an adapter ring comprising a mounting flange to engage the end of the sleeve, a first OD member having an outer diameter configured to engage the inner diameter of said sleeve, said first OD member laterally emanating from said adapter ring, and a second OD member having a second outer diameter configured to engage the inner diameter of said cylindrical body of said roller; and wherein in step “c” and “d” the step of applying said first and second mechanical mounts further comprises the steps of:

i. placing a first adapter ring about said shaft in the vicinity of said first end of said sleeve, engaging said first OD member to said inner diameter of said sleeve, engaging said second OD member to said inner diameter of said cylindrical body of aid roller, and fastening said adapter ring to said roller.

ii. placing a second adapter ring about said shaft in the vicinity of said second end of said sleeve, engaging said first OD member to said inner diameter of said sleeve, engaging said second OD member to said inner diameter of said cylindrical body of said roller, and fastening said adapter ring to said roller.

10) The method of claim 7, wherein said first and second mechanical mounts each comprise:

an adapter ring comprising a mounting flange to engage the end of the sleeve, a first OD member having an outer diameter configured to engage the inner diameter of said sleeve, said first OD member laterally emanating from said adapter ring, said mounting flange further having formed therein fastener apertures for receiving a fastener configured to engage and retain said adapter ring to an end of said cylindrical body of said; and wherein in step “c” and “d” the step of applying said first and second mechanical mounts further comprises the steps of:

i. placing a first adapter ring about said shaft in the vicinity of said first end of said sleeve, engaging said first OD member to said inner diameter of said sleeve, and fastening said mounting flange to said cylindrical body of said roller via said fastener apertures formed in said mounting flange.

ii. placing a second adapter ring about said shaft in the vicinity of said first end of said sleeve, engaging said first OD member to said inner diameter of said sleeve, and fastening said mounting flange to said cylindrical body of said roller via said fastener apertures formed in said mounting flange.

11). A corona electrode roller system for use with a roller having a cylindrical body having first and second ends, a length and an outer diameter, and a shaft longitudinally emanating therefrom, comprising:

a sleeve of dielectric material having a conductive inner wall, said sleeve having an inner diameter sufficient to enable said sleeve to slide over the outer diameter of the cylindrical body of the roller, while allowing the conductive inner wall of said sleeve to engage the outer diameter of said cylindrical body, said sleeve having a length to envelope the cylindrical body of the roller, while allowing said first and second ends of said sleeve to extend beyond the first and second ends of said cylindrical body of said roller when said sleeve is slipped over said cylindrical body of said roller, so as to provide first and second free ends of said sleeve emanating beyond the first and second ends of the cylindrical body of said roller;

first and second mechanical mounts for engaging said first and second free ends of said sleeve, and anchoring said first and second free ends to the roller, each of said first and second mechanical mounts further comprising:

fastening means for fastening said adapter ring to said first or second end of said cylindrical body of said roller.

12) The corona electrode roller system of claim 11, wherein said tube is formed of a conductive layer of carbon veil strip having laminated thereon a layer of filament winding bound together by resin.

13) The corona electrode system of claim 12, wherein the outer diameter of said sleeve has applied thereon a ceramic outer coating.

14) The coronal electrode system of claim 13, wherein said ceramic outer coating is a different color than the underlying filament winding and resin, so that the wearing through of said ceramic outer coating results in an observable color change.

15) The corona electrode system of claim 14, wherein there is applied to said ceramic outer coating a clear sealant.

16) The corona electrode system of claim 15, wherein the inner diameter of said passage formed through said expansion ring is tapered from a lesser inner diameter to a greater inner diameter, so as to facilitate compression of said compression base, as well as expansion of said outer diameter of said expansion ring, upon tightening of said compression base to said expansion ring.

17) The corona electrode system of claim 16, wherein said first and second mechanical mounts each further comprise:

an adapter ring comprising a mounting flange to engage the end of the sleeve, a first OD member having an outer diameter configured to engage the inner diameter of said sleeve, said first OD member laterally emanating from said adapter ring, and a second OD member having a second outer diameter configured to engage the inner diameter of said cylindrical body of said roller.

18. The corona electrode system of claim 17, wherein said first and second mechanical mounts each further comprise:

an adapter ring comprising a mounting flange to engage the end of the sleeve, a first OD member having an outer diameter configured to engage the inner diameter of said sleeve, said first OD member laterally emanating from said adapter ring, said mounting flange further having formed therein fastener apertures for receiving a fastener configured to engage and retain said adapter ring to an end of said cylindrical body of said roller.