Abstract: The present invention is directed to an electrode structure which is most applicable for plasticating barrels having wound, wire resistance heaters. Electrode structure includes at least one lower electrode plate and an upper electrode plate. A closely wound electrode band connected to the wound wire resistance heater is formed over the lower electrode plate to assure maximum electrical, and thus, thermal transfer. An upper ceramic layer is formed over the electrode band and wound wire resistance heaters. This upper ceramic layer can be ground down to accommodate the addition of an external plate on top of the upper electrode plate.

Abstract: The present invention is directed to an electrode structure which is most applicable for plasticating barrels having wound, wire resistance heaters. Electrode structure includes at least one lower electrode plate and an upper electrode plate. A closely wound electrode band connected to the wound wire resistance heater is formed over the lower electrode plate to assure maximum electrical, and thus, thermal transfer. An upper ceramic layer is formed over the electrode band and wound wire resistance heaters. This upper ceramic layer can be ground down to accommodate the addition of an external plate on top of the upper electrode plate.

Abstract: A plasticating barrel is provided with a primary heating system having at least one laminated ceramic heater, where the ceramic heater has an electrical insulating layer interposed between the ceramic heater layer and an outer wall of the barrel, and the longitudinal length of the ceramic heater is arranged over a portion of the barrel length. A secondary heating system may also be provided and overlaps, at least in part, the primary heating system.

Abstract: A barrel (11a, 11b) adapted for use in a plastics machine, has an inner layer of insulating ceramic (13a, 13b) disposed over and around the barrel along its length to form an insulated barrel, a wire layer (16, 16b) including a plurality of heating coils (17, 17b) of alloy resistance wire wound around the insulated barrel under tension in a spiral fashion, the wire layer also providing additional termination coils (18, 18b) near opposite ends of the barrel for making electrical contact with a source of electrical power to heat the barrel, and a top layer (19, 19b) of an electrically insulating ceramic disposed over the heating coils A method of making a barrel with a heater, comprises spraying a layer (12, 12b) of a metal bonding alloy over a portion of the barrel to be heated.

Abstract: A plasticating barrel is provided with a primary heating system having at least one laminated ceramic heater, where the ceramic heater has an electrical insulating layer interposed between the ceramic heater layer and an outer wall of the barrel, and the longitudinal length of the ceramic heater is arranged over a portion of the barrel length. A secondary heating system may also be provided and overlaps, at least in part, the primary heating system.

Abstract: A elastomer-covered roller (10) is provided with an improved bond coating for bonding the elastomeric cover (14b) to the core (11b). At least one layer of material (21) is thermally sprayed on the core (11b) to form a rough surface having a roughness from 400 microinches Ra to 2000 microinches Ra or greater. At least one layer (21, 25, 26, 31, 32) is either sufficiently permeable to divert bond-degrading fluids away from the bond line (22, 27, 33) or is impermeable to bond-degrading fluids.

Abstract: A elastomer-covered roller (10) is provided with an improved bond coating for bonding the elastomeric cover (14) to the core (11). At least one layer of material (15) is thermally sprayed on the core to form a rough surface having a roughness from 400 microinches Ra to 2000 microinches Ra or greater. In a further improvement a denser, less porous layer (17) may be applied next to the core to protect the core from corrosion, followed by a less dense layer (19) applied to the first layer and having a similarly rough surface (20) for good mechanical bonding.

Abstract: A elastomer-covered roller (10) is provided with an improved bond coating for bonding the elastomeric cover (14b) to the core (11b). At least one layer of material (21) is thermally sprayed on the core (11b) to form a rough surface having a roughness from 400 microinches Ra to 2000 microinches Ra or greater. At least one layer (21, 25, 26, 31, 32) is either sufficiently permeable to divert bond-degrading fluids away from the bond line (22, 27, 33) or is impermeable to bond-degrading fluids.

Abstract: A elastomer-covered roller (10) is provided with an improved bond coating for bonding the elastomeric cover (14b) to the core (11b). At least one layer of material (21) is thermally sprayed on the core (11b) to form a rough surface having a roughness from 400 microinches Ra to 2000 microinches Ra or greater. At least one layer (21, 25, 26, 31, 32) is either sufficiently permeable to divert bond-degrading fluids away from the bond line (22, 27, 33) or is impermeable to bond-degrading fluids.

Abstract: A elastomer-covered roller (10) is provided with an improved bond coating for bonding the elastomeric cover (14) to the core (11). At least one layer of material (15) is thermally sprayed on the core to form a rough surface having a roughness from 400 microinches Ra to 2000 microinches Ra or greater. In a further improvement a denser, less porous layer (17) may be applied next to the core to protect the core from corrosion, followed by a less dense layer (19) applied to the first layer and having a similarly rough surface (20) for good mechanical bonding.

Abstract: A elastomer-covered roller (10) is provided with an improved bond coating for bonding the elastomeric cover (14) to the core (11). At least one layer of material (15) is thermally sprayed on the core to form a rough surface having a roughness from 400 microinches Ra to 2000 microinches Ra or greater. In a further improvement a denser, less porous layer (17) may be applied next to the core to protect the core from corrosion, followed by a less dense layer (19) applied to the first layer and having a similarly rough surface (20) for good mechanical bonding.

Abstract: A corona treatment system (10d) has a corona treatment generator (11d), a first stationary electrode (12d) having a dielectric layer (18d) disposed thereon and a second roller electrode (13d) spaced from the first stationary electrode (12d) by a gap (15d). The second roller electrode (13d) has a layer of dielectric material (19d) disposed around a core (23d) and has a conductive layer (24d) disposed over a substantial portion of a length of the second roller (13d). A switch (20) is electrically connected between the conductive layer (24d) and an electrical ground, and the switch (20) is operable to switch the system between a grounded web mode and a dual dielectric mode.

Abstract: A roller (10) incorporating a heat pipe cavity (12) has a port (25) through which a medium (29) is flowed and a vacuum is drawn. The port (25) is sealed by a plug (20) which is lodged in a hole (14) by advance of a screw (16) against the plug (20) to form a metal-to-metal seal that will withstand pressures in the heat pipe cavity (12). A body of grease (21) is one of several ways disclosed for centering the plug (20) in the hole (14). The screw (20) can be advanced with a conventional Allen wrench or a special tool (35) having a driver head (22) on a shaft (23) that extends through a casing (24) for conveying medium or drawing a vacuum. The screw (16) has vents (28) to allow a vacuum to be drawn as the port (25) is sealed. A method of sealing is also disclosed.

Abstract: A thermal conduction roller (10) has a tubular roller core (11) with an inside surface; and an electrical insulator coat (16) primarily of zirconia on the inside surface, a heater coat (18) of titania or a titania blend is disposed over the insulator coat (16), and at least two electrical contact assemblies that are disposed inside the roller and electrically connect to the heater coat (18) as the roller (10) is being rotated. One embodiment utilizes an electrical insulator coat (16) in a range of thickness from about ten mils to about twenty mils. A thinner coat may not have sufficient dielectric strength, while a thicker coat decreases thermal conduction. A release material (12) is applied to the outside of the roller (10). Various contact structures according to the present invention are also described in detail, including one especially adapted to connect to a three-phase power supply.

Abstract: A thermal conductive roller (10, 80) for use in copying machines, steam-heated and induction-heated applications includes a ceramic heating layer (14, 84) formed by plasma-spraying a ceramic material to form an electrically conductive heating layer. In a first embodiment, power is supplied through connections on opposite ends of the ceramic heating layer (14). Ceramic insulating layers (12, 13) are used between the core (11) and heating layer (14), and between the heating layer (14) and the conductive layer (17). A conductive layer (17) is disposed over and around the ceramic heating layer (14) and the insulating layers (12, 13) to counteract the capacitive effects of the insulating layers (12, 13). Circuitry (38, 39) for detecting faults in the ceramic insulating layers (12, 13) is connected across lines (32, 33) supplying power to the roller, as well as to a conductive portion of the core (11) and to the conductive layer (17).

Abstract: An electrical contact assembly for a roller (10) having at least one single-bevel end portion (13) has a first electrical contact formed by a thermally sprayed band (29) of a nickel alloy, a second electrical contact (30) formed by an annular contact structure (57, 37, 38, 30) assembled to the roller (10) and a bridging contact formed by an extension coil spring (33) which extends around the tapered end (24) of the roller (10) in a location where it will make bridging contact between the first electrical contact (29) and the second electrical contact (30) and provide spring pressure to maintain such contact.

Abstract: A heat transfer roller in a machine for coating, printing, copying or heating a web, has a hollow cylindrical roller core and a metal sleeve for conducting heat to or from an object contacting an outer surface of the roller. A ring-shaped cavity for receiving a heat transfer medium is formed between the cylindrical roller core and the sleeve (15) and extends the length of the roller excluding portions on respective ends. Cartridge heaters are provided for heating the outer wall of the core to further heat the heat transfer medium in the heat pipe cavity. The ring-shaped cavity is divided into sector compartments by longitudinally extending barriers. Wicking material is disposed in respective compartments. The wicking material and flow restriction elements hold a portion of the heat transfer medium in the compartments while also allowing a portion of the heat transfer medium to move circumferentially around the roller to make temperature more consistent across the outer surface of the roller.

Abstract: A thermal conductive roller for use in copying machines, steam-heated and induction-heated applications includes a ceramic heating layer formed by plasma spraying a ceramic material to form an electrically conductive heating layer of preselected and and controlled resistance. Several methods of controlling the resistance of the ceramic heating layer are disclosed. The ceramic heating layer is sealed with a solid, low viscosity sealer such as Carnauba wax to protect the ceramic layer from moisture penetration. Electrical current is applied at or near the core and is conducted radially outward through the heating layer to an outer grounded metallic layer. An outer contact layer of metal, ceramic, or polymeric material can be added.

Abstract: A heated roller assembly (10) is disclosed having a rotatable roller (12). The roller (12) has a generally cylindrical section (20) with an outer diameter D and includes an inner insulative layer (36) thereover, a conductive layer (38) over the inner insulative layer (36), and an outer insulative layer (40) over the conductive layer (38). The roller assembly (10) also has an inwardly projecting conical portion (22) adjacent the cylindrical section (20) of the roller (12) with the inner insulative layer (36), conductive layer (38) and outer insulative layer (40) respectively thereover. A portion (A) of the conductive layer (38) on the conical portion (22) of the roller (12) is exposed. An external contact body (14) has at least one electrically conductive outer surface (46) that projects towards and contacts the conductive layer (38) of the conical portion (22) while piercing an imaginary plane P1 formed by an extending outer diameter (D) of the cylindrical section (20).

Abstract: A charging roller for use in a xerographic copying machine includes a cylindrical roller core, and a ceramic layer formed by plasma spraying a blend of an insulating ceramic material and a semiconductive ceramic material in a ratio which is selected to control an RC circuit time constant of the ceramic layer in response to an applied voltage differential. The ceramic layer is sealed with a solid, low viscosity sealer, such as Carnauba wax, to protect the ceramic layer from moisture penetration.