Abstract: A conveyor is provided that is capable of preventing degradation in quality of an article being conveyed. The conveyor includes a conveyor belt; and a rolling element rotatably provided at a surface of the conveyor belt. A plurality of rolling elements are provided along a conveying direction. The conveyor further includes a holder provided at the surface of the conveyor belt, for rotatably holding the corresponding rolling element. The rolling element has a ball shape.

Abstract: An axially rotatable materials handling apparatus for handling a mixture of solid particulate and water, includes a heater mounted on the housing that can transfer heat to the mixture to prevent or thaw frozen water inside the apparatus. The heater can be a combustible fuel heater or an electric heater. The apparatus is particularly useful in winter weather to prevent water from freezing inside the apparatus or to thaw any frozen water already present.

Abstract: A self cleaning conveyor roller for supporting a conveyor media carrying contaminant materials. The conveyor roller consists of a drum defining a support surface, having a generally cylindrical shape, and being adapted to be supported for rotation, for supporting a conveyor media. The conveyor roller has a plurality of abutments on the support surface, raised above the support surface, and defining a series of spaced apart conveyor media support ridges lying on a circular configuration, concentric with the drum. The abutments are arranged in generally chevron shapes, around the drum. During rotation of the conveyor roller the abutments cause any debris or contaminants between the roller and the conveyor media to be guided out of the conveyor system. Also disclosed is a method of cleaning a conveyor roller.

Abstract: A work conveying system for conveying works in a clean room includes a work holder for holding works, and a moving unit for moving the work holder.

Abstract: A dustproof linear actuator has: a housing with a slit extending axially; a linear guide device disposed in the housing; a carriage mounted in the housing and axially movable along the slit by the linear guide device, the carriage including a workpiece mounting table protruding from the housing through the slit; a linear drive device disposed in the housing for moving the carriage axially; a pair of pulleys disposed in an axial end of the housing; and a sealing band mounted around the pulleys within the housing movably for closing the slit, the sealing band including first and second ends which are fastened to first and second ends of the carriage, respectively, to form a circulative loop. Further, the dustproof linear actuator has an air venting device for venting air existing in the housing close to the axial end toward an outside of the housing so that the dustproof linear actuator can remarkably prevents the dust particles from leaking out of the housing by reducing the pressure inside the actuator.

Abstract: An apparatus for automatically cleaning the clips on a web processing apparatus is described. The apparatus includes a scraper for scraping the web supporting surface of the clips on the web transporting machine, and also desirably includes a clip opener, for facilitating opening of the clip to enable the scraper to easily access the clip web support surface. The scraper is desirably supported in a manner that enables it to move upwards and downwards relative to the web supporting surface of the clips, to account for variations in clip height and positioning. The clip cleaner can be readily applied to existing web processing apparatus, such as tenter frames, and desirably can be selectively moved from an operative position to an inoperative position.

Abstract: An automatic empty container return machine includes a detection unit operable for identifying whether or not an empty container is of a predetermined category, an input unit located upstream of the detection unit for receiving empty containers to supply the empty containers to the detection unit, an output unit located downstream of the detection unit for receiving empty containers that have been identified by the detection unit as being of the predetermined category, a transport stage having a conveyor for transporting empty containers from the input unit through the detection unit to the output unit, and a self-cleaning arrangement having components integrated with at least one of the input unit, detection unit, output unit and transport stage and being operable at selected times to clean surfaces thereof that are preselected to be cleaned.

Abstract: A dustproof linear actuator has: a housing with a slit extending axially; a linear guide device disposed in the housing; a carriage mounted in the housing and axially movable along the slit by the linear guide device, the carriage including a workpiece mounting table protruding from the housing through the slit; a linear drive device disposed in the housing for moving the carriage axially; a pair of pulleys disposed in an axial end of the housing; and a sealing band mounted around the pulleys within the housing movably for closing the slit, the sealing band including first and second ends which are fastened to first and second ends of the carriage, respectively, to form a circulative loop. Further, the dustproof linear actuator has an air venting device for venting air existing in the housing close to the axial end toward an outside of the housing so that the dustproof linear actuator can remarkably prevents the dust particles from leaking out of the housing by reducing the pressure inside the actuator.

Abstract: A device is provided for cleaning an endless conveyor. The device includes an endless brush belt engageable with the endless conveyor. A tension mechanism is provided for placing a tension on the endless brush belt. A clutch mechanism is operatively connected to the tension mechanism. The clutch mechanism prevents the placement of additional tension on the endless brush belt in response to tension exceeding a predetermined maximum tension.

Abstract: Feeder systems are mechanical systems that feed individual sheets of paper to other mechanical devices. Feeder systems need to be able to handle a variety of types of paper with different weights and finishes. Glossy paper has proven difficult to feed because of anti-offset agents used in the printing process. The agents contaminate the rollers in the feeder system causing misfeeds and jams. The present invention is a cleaning apparatus that can be used in conjunction with the feeder system to keep the feeder system free from malfunctions during the processing of glossy paper. The cleaning apparatus includes a cleaning head mounted on a supporting arm. Various types of abrasive cleaning heads can be employed in the cleaning apparatus such as metal blades, meshes and brushes. The cleaning heads keep the rollers operational while minimizing deterioration of the roller.

Abstract: A paint spraying apparatus for coating an article with paint, enamel, lacquer or the like, includes a conveyor unit having an endless conveyor belt, trained over at least two drums, for transporting an article to be coated past a sprayer unit. Operatively connected to the conveyor unit is at least one cleaning unit for wiping a surface of the conveyor belt clean. The cleaning unit includes an endless wiping belt which extends obliquely relative to the conveyor belt and is so operated as to revolve at a higher speed than the conveyor belt when contacting the conveyor belt.

Abstract: A handrail guide in an outdoor escalator contains a heating cable to prevent the handrail from freezing to an associated handrail guide in cold weather.

Abstract: An automated cleaning system for an endless belt conveyor. The cleaning system having a central control which controls pump supplying hot water, soap and a sanitizer to a plurality of controllable spray valves for plural spray bars.

Abstract: An automated cleaning system for an endless belt conveyor. The cleaning system having a central control which controls pump supplying hot water, soap and a sanitizer to a plurality of controllable spray valves for plural spray bars.

Abstract: A process and apparatus for cleaning a transport belt of a machine for the production or processing a web. The apparatus includes at least one nozzle device composed of a rotatable nozzle head having at least one cleaning nozzle, a transport device including a crosspiece extending substantially crosswise to a transport belt travel direction, in which the at least one nozzle device is coupled to the transport device and adapted for displacement along the crosspiece. A traversing speed of the nozzle device is very low and falls within a range of between approximately 1 mm/min and 10 mm/min. Alternatively, the at least one nozzle is positionable in a plurality of cleaning positions that are successively arranged crosswise to the transport belt, and the at least one nozzle is held stationary in each respective cleaning position for a predefined time period.

Abstract: A cleaning device for guide elements in the form of slide blocks utilized in escalators and moving walkways allows contaminants in escalators and moving walkways allows contaminants, which accumulate on the escalator and moving walkway base plates, against which the slide blocks run, to be removed during escalator moving walkway operation. Cleaning slide blocks are provided at at least one of the escalator steps or moving walkway plates instead of the slide block guide elements. The cleaning blocks may be formed of a thermoplastic synthetic material with a relatively high proportion of glass fibers. The glass fibers scrape the contaminants from the base plates during escalator moving walkway motion.

Abstract: An improved self-cleaning drive mechanism for driving a conveyor belt including a rotatable drive gear having a plurality of receiving grooves adapted to engage and drive the conveyor belt, the plurality of receiving grooves being disposed along a periphery of the rotatable drive gear, and a rotatable cleaning wheel having a plurality of cleaning members positioned to engage the plurality of receiving grooves as the rotatable drive gear is rotated. The plurality of cleaning members are sized to engage the plurality of receiving grooves and displace debris in the plurality of receiving grooves when the plurality of receiving grooves are engaged by the plurality of cleaning members. In one embodiment, the plurality of cleaning members may include a plurality of cleaning teeth disposed along a periphery of the rotatable cleaning wheel, the plurality of cleaning teeth extending radially outwardly from the rotatable cleaning wheel to engage the rotatable drive gear.

Abstract: A conveyor belt (5) for transport systems is described, containing an areal textile configuration based on predominantly synthetic yarns, characterized in that the conveyor belt has the form of an endless strip and the yarns extending in the running direction of the conveyor belt are elastic, the elastic yarns having a maximum tensile elongation of at least 60% and consisting at least 70 wt. %, referred to total yarn weight, of a thermoplastic, elastomer copolyether ester containing recurrent structural units of formulas I and II, —O—OC—Ar2—CO—O—R4—  (I) and —O—OC—Ar3—CO—O—R5—  (II), where Ar2 and Ar3 independently of each other represent bivalent aromatic radicals, R4 represents a bivalent aliphatic or cycloaliphatic radical, and R5 stands for the bivalent radical of a polyalkylene ether. Likewise described are uses of this conveyor belt, a method of transporting goods, and a transport system.

Abstract: A sorting system includes a trolley movable along a predetermined path and including an endless belt rotatable in a direction perpendicularly to the path for receiving and discharging items to be sorted. To clean a surface of the belt, a dispensing device and an aspirating device are suspended over the belt surface on an arm. With the belt rotating, the dispensing device sprays cleaning liquid onto the belt surface, and the aspirating device sucks up the cleaning liquid at a location downstream of the dispensing device with reference to the direction of belt travel. The arm can be raised and lowered and/or moved parallel to the path for cleaning other trolleys.

Abstract: A cleaning apparatus (1), to clean a conveyor belt (3) curving in its main plane, comprises a cleaning drum (9) of which the diameter at its end (9i) adjacent to the belt's inner edge (3i) is smaller than its diameter at its end (9a) adjacent to the outer edge (3a).

Abstract: An underguard assembly is provided for use with a modular conveyor of a conveyor system. The underguard is formed of a flexible web that hangs beneath the conveyor to catch debris falling from the sides of or through the conveying surface. To support the web, a stiffener rod is placed in an elongate pocket formed along each longitudinal edge. Opposed support assemblies spaced along the sides of the conveyor frame hold the enlarged pocket formed by the stiffener rod. An adjustment means is provided on each support assembly that allows the web to be easily attached and detached from the conveyor frame. Further, the support assemblies adjacent the end of the conveyor are modified to support the web beyond the end of the conveyor. This allows the web of a first modular conveyor to overlap with the web at the start of an adjacent modular conveyor, thereby providing a substantially seamless underguard function for a conveyor system.

Abstract: In an image forming apparatus, a cleaning device using a webbing is capable of surely removing stains firmly adhered to a desired surface to be cleaned. Even when the degree and the kind of contamination on the above surface is irregular due to the varying operating condition of the apparatus, the cleaning device is operable in a desirable manner. The cleaning device includes a webbing pressed against the surface to be cleaned and a pressing member having a plurality of projections with edge portions at the ends of the projections and wherein at least two of the projections are in the cleaning range at any one time. In a preferred embodiment, the cleaning device is provided in an image forming apparatus and cleans a conveyor belt for conveying a recording medium to which a toner image is to be transferred.

Abstract: A screw conveyor for tacky media has members such as chains disposed in rest positions extending into the trough laterally of the screw axis. These members are engaged and deflected by the screw blade as it progresses along said axis. The members are subject to a restoring moment, such as the force of gravity, tending to forcefully restore the members to the rest position from the deflected positions so that the media is forcefully impacted by the members and adherent media is dislodged from the blade and agglomerates are disintegrated.

Abstract: In one embodiment, the invention comprises at least one and preferably a plurality, of rollers provided with recesses which are mounted on the drive and trailing assemblies of a conveyor system. The recesses of each roller include abutment surfaces angularly disposed relative to the central axes of their respective drive or trailing assemblies and are sized to receive, support and align the belt. Alternative embodiments employing polygonal rollers, rollers with a single wall forming two angled abutment surfaces and rollers with support surfaces disposed to receive multiple belt segments are also provided. The rollers, in addition, may include sets of the recesses distributed in circumferential rows about their periphery, including an odd number of sets of recesses to reduce wear on the roller. A method for estimating the optimum size and configuration of the rollers of the invention for helical woven wire endless belts is also provided.

Abstract: A conveyor system for transporting and aligning articles to be sorted in an automated bulk processing system is disclosed. The conveyor comprises one or more product-carrying lanes, each lane comprising two side belts separated by a central product-carrying belt. Each of the side belts is raised with respect to the product-carrying belt, thereby guiding articles on to the product-carrying belt. In a preferred embodiment, the product-carrying belt has two product-carrying surfaces and is provided with a 180.degree. lengthwise twist whereby the product-carrying surfaces are alternately presented on the upper surface of the conveyor system for each complete belt travel cycle. The 180.degree. lengthwise twist is maintained in position by a belt guide or comb located on the underside of the conveyor system.

Abstract: Apparatus and method for cleaning conveyor systems, particularly for removing dust and other contaminants from optical processing equipment. A rigid or flexible sheet is coated on one or both faces with a tacky elastomer which is preferably a silicone. The sheet is moved over or through the conveyor system in place of a conveyed article, so that contaminants adhere to the elastomer and are ultimately removed from the conveyor along with the cleaning sheet. The invention is particularly applicable to cleaning conveyors transporting photographs and photo-tools, and to cleaning reprographic equipment incorporating paper transport rollers, eg photocopiers, facsimile machines, and desk-top printers.

Abstract: An apparatus in which a photoreceptor cleaning blade is mounted to an extension of the coupler link of a four bar linkage. A torsion spring is positioned at the pivot of the crank link to create the torque on the crank link. A weight or solenoid can also be used to create the torque on the crank link. This torque supplies the force to the mounted cleaning blade. The instantaneous center of rotation is a virtual pivot point which is located on the photoreceptor tangent plane. The linkage reaction forces and the blade friction load all pass through the virtual pivot point leaving the blade load a function of the torque on the crank link.

Abstract: An endless transport conveyor for sorting tobacco containers, specifically sheets and bales. The tobacco container sorting conveyor includes an endless foraminous belt with top and bottom runs, a slotted support located below the top run, a collecting pan located below the support and a motor for driving the endless belt. A supply conveyor is adjacent one end of the transport conveyor and loads the tobacco containers onto the belt. As the tobacco containers are conveyed, tobacco particles that fall through the belt and support are received on the collecting pan. Diverting assemblies mounted along one side of or above the belt selectively divert the tobacco containers, via the input from sensors, into station chutes mounted along one or both sides of the belt and opposite from each diverting assembly. An end chute and bin may extend from the end of the transport conveyor or opposite the supply conveyor for collecting tobacco waste too large to fall through the belt.

Abstract: A profiled guide rail, for use in providing a guide path for a roller chain in a web-fed rotary printing press, utilizes a plurality of slits as paths through which ink particles and paper dust can pass out of the track in the guide rail along which the roller chain travels. These slits pass through at least one leg of the guide rail and are longitudinally spaced in the direction of travel of the roller chain.

Abstract: A conveyor having a plurality of link assemblies with a leading end of each link assemblies being connectable to the trailing end of one of the other link assemblies for forming the conveyor belt. A plurality of spaced apart leading shaft projections are formed on the leading end of each link assembly and a plurality of trailing shaft projections are formed on the trailing end of each link assembly. Each of the leading shaft projections has a thickness which is greater than a thickness of each of the trailing shaft projections. Each of the leading shaft projections has a first wall and a second wall. The first and the second walls are each formed on a radius and curved inwardly from an upward end toward a lower end of each leading shaft projection. The trailing shaft projections are disposed in the spaces between the leading shaft projections and the curved walls on the leading shaft projection cooperate to expose a substantial portion of the shafts connecting adjacent link assemblies.

Abstract: A device for removing barnacles from a boat lift including an elevator riding on rails extending into a body of water, characterized by a blade and a mounting adapter connecting the blade to the elevator of the boat lift. The blade is positioned to remove barnacles from a submerged portion of a rail as the elevator traverses the rail.

Abstract: An endless transport conveyor for sorting tobacco containers, specifically sheets and bales. The tobacco container sorting conveyor includes an endless foraminous belt with top and bottom runs, a slotted support located below the top run, a collecting device located below the support and a motor for driving the endless belt. A supply conveyor is adjacent one end of the transport conveyor and loads the tobacco containers onto the belt. As the tobacco containers are conveyed, tobacco particles that fall through the belt and support are received on the collecting device. Diverting assemblies mounted along one side of or above the belt selectively divert the tobacco containers into station chutes mounted along one or both sides of the belt and opposite from each diverting assembly. An end chute and bin may extend from the end of the transport conveyor or opposite the supply conveyor for collecting tobacco waste too large to fall through the belt.

Abstract: In one embodiment, the invention comprises at least one, and preferably a plurality, of rollers provided with recesses in their peripheral surfaces and mounted on the drive and trailing assemblies of a conveyor system. At least one side wall of each recess is angularly disposed relative to the central axes of the respective drive or trailing assemblies and the recesses are sized to receive therein a portion of the belt contacting the rollers. The bottom and side walls of the recesses act against the engaged portion of the belt to propel the belt through the system, support the belt and maintain the belt in proper tracking alignment. Alternative embodiments employing polygonal rollers, alternately slotted rollers and rollers with "single sided" recesses are also provided.

Abstract: A turn conveyor system includes a plurality of friction-reducing members disposed along at least the inner edge of the belt to minimize the friction between the belt and the conveyor frame. The members are formed, in whole or in part, from a plastic material having a coefficient of friction of less then 0.2 and may advantageously include raised vee-shaped portions adapted to remove debris from between the belt and the frame.

Abstract: Disclosed herein is a wastewater treatment facility including a stacked tank clarifier having a lower tank, and an upper tank above the lower tank, the upper tank having a bottom defining a ceiling of the lower tank, and the lower tank further having a floor. The wastewater treatment facility includes a mechanism for scraping the ceiling of the lower tank. The mechanism includes a driven endless chain loop in the lower tank, and a buoyant member carried by the chain loop.

Abstract: A printer apparatus including a print head assembly and a transport belt for transporting a workpiece such as a plastic card through the printer apparatus. The transport belt includes a surface self-adhering to a surface of the plastic card. In a preferred embodiment, the printer apparatus includes a print head which is moved across a surface of the card while printing on the card. The printer apparatus includes a print head controller for interfacing between at least one microprocessor and at least one continuous tone print head, the number of print intensities either fixed or selected by the microprocessor.

Abstract: A free-standing cleaner (10) for conveyor belts (60) constitutes a tank (12) for holding fluid and having a removeable pad (22) attached across its bottom surface (14). Nozzles (20) in the bottom surface deliver the cleaning fluid to the pad (22). One longitudinal end (18) of the tank depends from the majority of the bottom surface (14) and hooks over the upstream end of the conveyor for anchoring the tank (12) against movement with the conveyor belt (60). Tandem tanks may be joined to the downstream end of the first tank for applying multiple cleaning fluids to the belt (60).

Abstract: The underside of an escalator or moving walkway handrail is continuously cleaned by an assembly which includes rotating brushes associated with a vacuum nozzle which removes loosened debris from the handrail. The brushes are preferably driven so as to rotate in opposite directions to sweep debris toward the vacuum nozzle. The vacuum nozzle empties into a container which can be periodically emptied during normal servicing of the escalator or walkway.

Abstract: A conveyor elevator system having an endless conveyor belt in which guide rollers are provided to contact and guide the side edges of the belt to prevent lateral shifting thereof. A discharge plate is provided at the lower end of the vertically upwardly moving reach of the conveyor belt for receiving particulate material that escapes from the upwardly moving reach of the belt and falls downwardly. The discharge plates guide the escaped material into the carrier plate passage so that the escaped material is recycled. The skirt plates that define the sides of the carrier plate passage having seal elements that cooperate with projecting elements on the conveyor belt to form a labyrinth passage to reduce the amount of material that escapes.

Abstract: A cleaner comprising a rotary drum, radial rubber blades attached to the outer surface of the drum, and abrasion-resistant ceramic members each secured to the outer edge portion of each of the blades.

Abstract: A bakery oven system is disclosed which includes a bakery oven through which an endless conveyor may pass that carries bakery products to be treated in the oven. The conveyor includes a conveyor section located out of the oven and adapted to pass through a grid burn-off unit which serves to clean the grid on the conveyor. The grid burn-off unit includes a separate enclosure having a burner arrangement for applying heat to the conveyor to burn off residue on the conveyor. A plurality of brushes are located downstream of the burn-off enclosure, in the direction of travel of the conveyor, to clean carburized material off of the conveyor.

Abstract: The invention relates to a shavings conveyor which has a continuously turning conveyor belt (1) provided with two lateral conveyor chains (2) as well as a housing (6) equipped with guide rails (8) for these conveyor chains, openings (11, 12) for the coolant to pass through being provided in the upper guide rails (8) of the conveyor chains. In this way a structurally simple conveyor is produced in which the delivered coolant can run off laterally in a reliable and quick manner through the region of the upper conveyor run (14).

Abstract: A conveyor belt is provided for carrying granular coal or ore from a mine or a crushing station, together with a belt heater in the form of a fuel burner which turns on to melt ice which as formed on the belt at temperatures below freezing. The belt heater heats the conveyor belt surface to a temperature sufficient to melt the ice film to form water and thereby prevent the granular coal or ore from sliding to impair the conveying operation of the conveyor belt or to cause spillage from the conveyor belt. When the conveyor belt stops, the fuel burner stops and thus prevents damage to the conveyor belt. A preferred fuel burner is an oil heater. An infrared heater can also be used but a fuel burner is preferred in flame contact with the belt. The flame of the fuel burner when used in direct contact with the conveyor belt can be immediately shut off when the conveyor belt stops and thereby prevents damage to the conveyor belt. The flame temperature or air temperature reaches a value of at least about 400.degree.

Abstract: The present invention relates generally to conveyor belts and, more particularly, but not by way of limitation, to a conveyor belt having ribs formed on a lower surface thereof for moving particles generally outwardly toward the first and the second sides of link assemblies which form the conveyor belt, and to a conveyor belt constructed of modules shaped so that the interconnections between modules are offset between each link assembly and adjacent link assemblies, and a flight link having curved portions formed the faces thereof so product slides on the surfaces rather than being toppled and a conveyor belt with a tracking product groove to substantially limit lateral movement of the conveyor belt.

Abstract: A linear motor driven conveyor apparatus is disclosed for conveying trucks carrying articles to be processed through a paint booth or other treatment area having a dirt-laden atmosphere, and a water tank is provided in the treatment area in which the secondary member of the linear motor is immersed to keep its surfaces free of contaminants.

Abstract: A bucket distribution system for receiving products at an infeed station and selectively discharging the products at a plurality of distribution stations. A plurality of buckets travel in a continuous path and each receive a predetermined portion of products at an infeed station. Bucket trip apparatus at each of the discharge stations selectively pivots the buckets in a direction opposite to the direction of bucket travel to cause the buckets to discharge products therein. Feeders at primary distribution stations are adapted to roll in and out of position for servicing. Products may recirculate within the system to thereby reduce the amount of products taken off-line.

Abstract: A conveyor flight for a conveyor assembly has an overlayment of a non-elastomeric flexible member on its front or loadbearing surface, which flexible member has a memory such that it recovers to its unloaded reference condition, thus assisting in discharge through an underlying chute or port of the materials transported by the conveyor and avoiding recycling material through the conveyor assembly. The flexible member recovery dislodges adherent material, such as compactible earth, from the conveyor flights. A cleaner assembly may optionally be provided downstream of the discharge port to insert a cleaner blade in proximity to the conveyor flight front surface to dislodge any particularly adherent residual materials that might still be attached to the front surface of the flexible member.

Abstract: A material-conveying apparatus includes an endless belt supported for travel in a path extending around a pair of rollers. A pair of support plates extend beneath the lateral edges of the belt along an upper run of the belt each of the support plates including an opening extending therethrough which permits material passing incidentally between the belt and the support plate to pass to an area beneath the support plate. A pair of deflection plates are disposed beneath the support plates. The deflection plates each include an upper edge which is disposed beneath and between the lateral edges of the upper run of the belt and extend downward and laterally outward relative to the upper run of the belt to a lower edge which is disposed laterally outward of the edges of the belt, whereby the material passing through the openings is directed by the deflection plates to an area laterally displaced from the lower run of the belt.

Abstract: An electric arc furnace includes a crucible having a metal shell for recovering precious metals from spent material. The shell includes a metal tap hole and a slag door positioned above and opposite the metal tap hole. A removable swinging roof is provided above the crucible together with a plurality of electrodes for heating the spent material. Also, a cooling band circumscribes the crucible for cooling the metal shell. Conveyors are provided for distributing the spent material at a plurality of points located between the electrodes and the wall of the crucible. The crucible is tilted to allow the removal of the slag and metal.

Abstract: A multiplicity of web guide rollers in a printing machine incorporate motors therein provided with respective reduction units and each reduction unit is provided on the side of an output shaft with a mechanism such as a clutch, so that the rollers can rotate normally, reversely or idly. When the web guide roller is cleaned, the roller is rotated in a direction opposite to the running direction of the web, whereby the contamination on the surface of the roller is wiped off by the web. Since the rotating directions of the respective rollers are selected by the controller in association with running paths of webs, so that automatic cleaning of the web guide rollers can be effectively performed.