Abstract: As one embodiment, a paper feeding device is provided with a pickup roller for pulling out an uppermost positioned sheet of loaded sheets, and a paper feeding roller for transporting the sheet pulled out by the pickup roller. Spanning between the pickup roller and the paper feeding roller, a roller belt is provided that is capable of moving relatively in a circumferential direction with respect to an outer circumferential surface of the paper feeding roller. The roller belt obtains rotational drive from the pickup roller.

Abstract: A sheet feeding device including a belt including a dielectric material seamlessly wound about rollers and disposed opposite a top surface of a stack of multiple sheets placed on a sheet storage stand to attract a sheet from the stack of multiple sheets and convey the sheet, and a charger to form a predetermined charge pattern on a surface of the belt. A shaft of one of the rollers provided downstream from the other roller in a direction of sheet feed serves as a pivot of the belt about which the belt swings, and the belt swings around the pivot such that the surface of the belt facing the top surface of the stack of multiple sheets and a surface of the sheet storage stand facing the surface of the belt are substantially parallel to each other.

Abstract: An item transport system includes a first transport element rotating around a plurality of first transport rollers in a first direction, a second transport element in opposing relation to the first transport element, the second transport element rotating around a plurality of second transport rollers in a second direction opposite to the first direction, a guide plate proximate to the first transport element for engaging the items during processing by an item processing element, and an item registration device configured to maintain the items in registration with the guide plate. The item registration device includes a plurality of independently articulating pivot assemblies biased to engage the second transport element with the first transport element and a plate associated with each pivot assembly. Each plate is fixedly constrained with respect to the pivot assembly at one end and slidably constrained with respect to the pivot assembly at another end.

Abstract: An adjustment mechanism for use on a friction sheet feeding machine to permit selective lateral repositioning of one feed belt on the machine relative to at least one other feed belt on the machine.

Abstract: In a device for singulating vertically positioned flat mailings from a stack of mail, at least two discharge rockers are disposed on top of one another, wherein the discharge rockers are adjacent to revolving second discharge belts that are arranged in a fixed manner along the path of travel. A supporting element in relation to which the stack of mail is aligned ends at a defined distance from the undeflected discharge rockers. A flexible, elongated retaining element is arranged in a resiliently pressed manner from the end of the supporting element to the beginning of the second discharge belts located downstream of the discharge rockers and further on to the discharge rockers and to further discharge belts of successive singulating stages. The distance of the supporting element from the leading end of the second discharge belts relative to the direction of travel is greater than the maximum permissible length of a mailing.

Abstract: A paper-pickup clutch of an automatic paper-feeding device includes a clamping member and a clamping-force adjusting member and can be applied to image processors such as printers, copiers or scanners. The automatic paper-feeding device includes a shaft and a paper-pickup mechanism transmitted to picking up paper by the shaft. The paper-pickup clutch provides a bi-directional clutch function by moving the clamping member toward or away from the paper-pickup mechanism with the clamping-force adjusting member in order to adjust the clamping force of the clamping member working on the paper-pickup mechanism to a certain level. With the certain level of clamping force, the paper-pickup mechanism sustains against paper to be fed and self-rotates with the rotation of the shaft in a first direction for feeding paper and rotates with the shaft in a second direction for releasing paper without further changing the state of the paper-pickup clutch.

Abstract: In a friction sheet feeder for feeding sheets to an inserting machine, paper guide extensions are provided, connected to paper guides on the feeder and positioned and adapted to guide each sheet both laterally and vertically to the necessary position for the inserting machinery to which it is attached. The extensions are mounted to the paper guides so as to be adjustable up and down to allow for precise delivery of the sheets being fed. Paper hold downs are attached to the paper guide extension and a sheet stop photo cue is attached permanently to at least one of the paper guide extension to stop sheet in precise position until the inserting equipment pulls the sheet away. Preferably, the paper guide extensions are mounted to the paper guides with a single locking bolt and nut.

Abstract: For the separation of the sheets of a record carrier from a pile (10) in order to feed them to an office machine or a printer, a rolling action device (14) sits on the uppermost sheet (12) of the pile (10). By means of the rolling action device (14), the uppermost sheet (12) is loosened from the following next sheet (20) and is pushed against a stop in the feeding direction. The stop is positioned at an impingement angle of at least 90 degrees in relation to the plane, in which the uppermost sheet (12) is being pushed against the stop. Then the stop is moved upwards so that it could pick upwards the front edge of the uppermost sheet (12). The stop can be built, for instance, of at least one upwards-running belt (22).

Abstract: Sheets (12, 14) of a print medium kept in a stack (10) are individually fed into an office machine. The edge of the uppermost sheet (12) is raised off the corresponding edge of the following second sheet (14). At least one band (32) is then inserted into the gap formed in this way, which separates the uppermost sheet (12) from the following sheet (14), reducing thereby the friction between the uppermost sheet (12) and the following sheet (14) when the uppermost sheet (12) is pulled off, and minimizing thereby any electrostatic charge of the sheets (12, 14) caused by such friction. The band (32) can be retracted into a band housing (36).

Abstract: A system and method include a printer input, a feedhead assembly, first and second sensors and a controller. The printer input is configured to hold a stack of media. The first sensor is coupled to the feedhead assembly and configured to measure at a first location of the stack of media. The second sensor is coupled to the feedhead assembly and is configured to measure at a second location of the stack of media. The controller communicates with the feedhead assembly and the first and second sensors to calculate a curvature of the stack of media in the input feeder.

Abstract: Sheets (12, 14) of a medium stored in a stack (10) are separated and fed into an office machine. The edge of the top sheet (12) is lifted off the corresponding edge of the following second sheet (14). At least one separator (26) is inserted into the gap (32) resulting from the lifting of the top-sheet (12) and the top sheet (12) is lifted by the separator from the following sheet (14). This causes a reduction of the friction between the top sheet (12) and the following sheet (14) during separation of the top sheet (12), so that the electrical charge of the sheets (12, 14) generated by this friction is minimized.

Abstract: An ink jet printer includes a housing that defines a print media entrance opening and a print media exit opening. A support frame is arranged in the housing between the openings. A print media feed roller assembly is mounted on the frame proximal the entrance opening and a print media exit roller assembly is mounted on the frame proximal the exit opening. A print engine is mounted on the frame downstream of and adjacent to the feed roller assembly. A belt-loading mechanism is mounted on the frame and is interposed between the print engine and the exit roller assembly to load an initial portion of a sheet of print media between the roller assemblies prior to a printing operation to be carried out by the print engine.

Abstract: A document separator for use in a document processing machine. The document separator has a flexible loop of material adjacent to a document transport mechanism so that it holds one or more documents back from being transported along a transport path while allowing a single document to be moved forward.

Abstract: A tape transport system for printed products includes a tape having a tape width, a pulley, and a lever arm supporting the pulley, the lever arm having a first side and a second side. The pulley has a first section disposed on the first side of the lever arm and a second section disposed on the second side of the lever arm, the first and second sections supporting the tape so that the lever arm is within the tape width.

Abstract: A paper-pickup clutch of an automatic paper-feeding device includes a clamping member and a clamping-force adjusting member and can be applied to image processors such as printers, copiers or scanners. The automatic paper-feeding device includes a shaft and a paper-pickup mechanism transmitted to picking up paper by the shaft. The paper-pickup clutch provides a bi-directional clutch function by moving the clamping member toward or away from the paper-pickup mechanism with the clamping-force adjusting member in order to adjust the clamping force of the clamping member working on the paper-pickup mechanism to a certain level. With the certain level of clamping force, the paper-pickup mechanism sustains against paper to be fed and self-rotates with the rotation of the shaft in a first direction for feeding paper and rotates with the shaft in a second direction for releasing paper without further changing the state of the paper-pickup clutch.

Abstract: Apparatus for feeding sheets and other flat articles, especially with varying thickness, or from stacks of varying height, includes a device called a prompter. The prompter (136) comprises a body (137), a drive roller (142), mounted on and driven by shaft (135), an opposing idler roller (141), and a ribbed belt (138) stretched around the rollers. The body pivots about shaft (135) at the driven roller end. The prompter may alternatively feed articles from a stack to a singulator or other device, or it may comprise the driver of a singulator. A prompter (136), used as driver, combines with a retarder (120), called a dancer, to form a singulator (133). The dancer moves back and forth along the article flow path (121), responsive to thickness of articles, or to pull force on an article by a downstream takeaway device, to thereby automatically adjust the gap at the nip (144) of the singulator.

Abstract: Two belt type singulators are used in apparatus which feeds and singulates stacked articles which have varying thickness and shape. The singulators form tandem, spaced apart singulator nips with a transport belt. Each singulator belt has a downwardly sloped underside and moves incrementally around its rollers over time, overcoming certain applied resistive forces. The singulator belt has intermittent contact with the transport belt, when articles are being processed, and there is a resultant scuffing of belts which helps remove debris. Preferably, on off the forces which resists singulator belt motion is created by having a singulator pair with upper rollers, which are rotationally coupled but which have different diameters. The upper ends of the singulator belts project into the hopper which holds the stack and aid in the feeding of articles toward the singulating nips.

Abstract: A drawing-device mechanism includes an endless drawing device and two wheels, around which the drawing device is partially looped. One wheel has a locally fixed axis of rotation and the other wheel is adjustable within an adjustment range. A drawing-device tensioner produces pretensioning. During an adjustment of the second wheel, with an increase in the center-to-center distance in a first case and with a reduction in the center-to-center distance in a second case, the drawing-device pretensioning remains approximately unchanged as a result of a reduction in the looping of the drawing device around the drawing-device tensioner in the first case and an increase in the looping of the drawing device around the drawing-device tensioner in the second case, absent any change in location of the drawing-device tensioner. A machine such as a sheet-processing rotary printing machine has the drawing-device mechanism.

Abstract: The invention relates to a device for the delivery of flat objects to a friction/suction picking device with a suction head, the objects standing in a stack on a thin edge thereof on a support surface arranged on a stop surface and transported in the direction of the picking point using conveyor means. A sensor for measuring the vacuum in the suction head, is arranged on or in the suction head, which is connected to the drive controller on the conveyor means. Depending on the measured vacuum the conveyor means can be controlled such that the front object has an inclination as low as possible with the lowest possible stack pressure on the at least one friction picking device.

Abstract: A transmission mechanism comprising three drive rollers, one idle roller, one belt, and an elastic member. The belt is tightened around the drive rollers, where they drive the belt to rotate. The elastic member activates the idle roller causing the idle roller to exert a force on the belt for moving a document between the idle roller and belt during transportation of the document.

Abstract: A device for feeding sheets of a recording medium from a stack to an office machine, having movable elements which are moved by way of driven continuously rotating traction devices in the feed direction over the respective top sheet of the stack. The movable elements are supported by guide skids and are in contact with the top sheet under pressure to separate the top sheet from the second sheet of the stack beneath it and displace the top sheet with respect to the second sheet in the direction of feed. The movable elements each have at least one roller arranged across the direction of feed, mounted so it can rotate freely on a traction device.

Abstract: A sheet feeding device of the present invention includes a feeding mechanism including a belt and a reverse roller, and circular collars or similar spacing members adjoining the belt for spacing the reverse roller and belt. When a single sheet is conveyed from a nip between the belt and the reverse roller to a preselected position downstream of the nip in the direction of sheet feed, the spacing member spaces the belt and reverse roller with the drive of only the belt or the drive of both of the belt and reverse roller being interrupted.

Abstract: An article dispensing mechanism in which a plurality of stacks are mounted on a platform. Each has a plurality of articles such as paper sheets. The platform is moved from an article feeding position to a non-feeding position. An article feeding mechanism is mounted above a stack at the article feeding position. The article feeding mechanism feeds an article from the top of a stack at said article feeding position. When a stack at the article feeding position is devoid of articles, the platform is moved from the feeding position to the non-feeding position to present another stack to the feeding position.

Abstract: The present invention relates to a selection device for separating one by one, or singulating, the items of a stack of mail items, comprising a support surface, conveying means for driving these mail items over the support surface, a mobile presser plate cooperating with the conveying means in order to drive downstream a part of the mail items issuing from the stack of mail items to be separated and corresponding to a predetermined maximum thickness of mail items, and independent, individually mobile selection means for selecting a mail item from the mail items driven by the conveying means.

Abstract: A method and apparatus for feeding a currency note into a currency processing machine. This note feeder includes a transporter for transporting notes from a note stack onto a processing belt inside the currency processing machine. The note feeder also includes a mediating transporter that takes the note from the transporter and feeds the note onto the processing belt. The note feeder also includes sensors for determining when the note has left a first feeding area and entered a second feeding area and to determine whether multiple notes have entered the second feeder section. The note feed also includes and a sensor that determines when the note has entered onto the processing belt. Based on information received from the sensors, the transporter starts and stops thus providing uniform spacing between notes.

Abstract: The invention pertains to a method for removing flat mail pieces from a pile by means of a removal device with controllable removal velocity which feeds the mail pieces to conveyor belts driven at the velocity v0. Set velocity value profiles are associated with the differences between set and actual gaps. Since the curve forms are selectable, the drive ratios can be taken into account. The association of the set velocity value curves of the drive unit with the actual gaps in order to achieve the set gap at the takeover point of the conveyor belts at velocity v0 takes place in previous measurements. The nonlinearities of the transfer function of the drive unit are detected by tabular assignment of the velocity profiles on the basis of measurements.

Abstract: A sheet feeding device of the present invention includes a feeding mechanism including a belt and a reverse roller, and circular collars or similar spacing members adjoining the belt for spacing the reverse roller and belt. When a single sheet is conveyed from a nip between the belt and the reverse roller to a preselected position downstream of the nip in the direction of sheet feed, the spacing member spaces the belt and reverse roller with the drive of only the belt or the drive of both of the belt and reverse roller being interrupted.

Abstract: A high capacity document sheet processor combines significant speed and efficiency enhancing improvements in existing approaches to stack feeding particularly in the stack loading, feeding and singulating functions with novel operational arrangements adaptable to a universal paper handling and envelope inserting system.

Abstract: A method for controlling and adjusting nudger drive friction force. The nudger drive friction force is measured and compared with a desired nudger belt friction force term needed for reliable feeding. Cable drum motor torque is responsively adjusted to obtain a desired nudger drive friction force.

Abstract: A suction belt conveyor for a sheet processing machine includes an operationally revolving endless suction belt having, at an outer side thereof a filigree structure formed by indentations, the suction belt being formed with penetrating bores terminating in the indentations. In a variation of the foregoing, the suction belt conveyor for a sheet processing machine includes an operationally revolving endless suction belt formed with pores distributed in longitudinal and transverse directions of the suction belt, so that the suction belt is air permeable.

Abstract: A method and apparatus for feeding a currency note into a currency processing machine. This note feeder includes a transporter for transporting notes from a note stack onto a processing belt inside the currency processing machine. The note feeder also includes a mediating transporter that takes the note from the transporter and feeds the note onto the processing belt. The note feeder also includes sensors for determining when the note has left a first feeding area and entered a second feeding area and a sensor that determines when the note has entered onto the processing belt. Based on information received from the sensors, the transporter starts and stops thus providing uniform spacing between notes.

Abstract: There is provided a recording medium transportation apparatus providing air suction to adhere a recording medium to a belt while the recording medium is being transported thereby, wherein the belt can have an optimized surface roughness and adjacent suction holes provided therein can be spaced by an optimized distance to provide an optimized level of force allowing the belt to adhere to the recording medium to transport the recording medium with high precision. The belt transporting a sheet of paper adhered thereto through air suction has a surface roughness (Ra) set in a range obtained by substituting an equivalent adhesion diameter (Dx) defined by: 0.5 × D ⁢   ⁢ 0 2 ⁢   ⁢ e c0 / c1 ≦ Dx ≦ 0.

Abstract: A dispensing apparatus for thin flat articles, such as monetary currency bills, includes a plenum chamber having an aperture of a size smaller than the articles to be dispensed. A suction device is connected to the plenum chamber to provide sufficient negative pressure to adhere an article to the aperture. A contact member, such as an endless belt, is mounted for movement across the aperture to drive the article adhering to the aperture for release from the stack of articles. The stack of articles can be stored in a storage tray and biased towards the plenum chamber aperture. A series of spacer members can relieve part of the bias pressure. The released articles can be counted and stored in a storage chamber until a predetermined number of articles are accumulated. Subsequently, the passageway from the storage chamber to a dispenser tray can be opened and the articles ejected to the user.

Abstract: The invention relates to a method for controlling an apparatus for doffing flat shipments at a controllable doffing speed that delivers the shipments at constant speed to driven conveyor belts. According to the invention, the speed at which the shipment to be doffed must be transported, from the time it reaches a first sensor for detecting the shipments until it reaches a corresponding second sensor in order to achieve a desired gap is ascertained. The first sensor is located at the position at which the shipments (1′) to be doffed have reached a fixed mean doffing speed, and the second sensor is located at the point of takeover by the conveyor belts.

Abstract: An object of the present invention is to provide a sheet feeding apparatus that has sheet supporting device for supporting a sheet, a driving rotary member driven and rotated by a driving source, a rocking member disposed rockably on the driving rotary member, a sheet feeding rotary member rotatably disposed on the rocking member and can be brought into contact with the sheet supported by the sheet supporting device, a following rotary member coupled with the sheet feeding rotary member on the rocking member, a winding and hanging member hung around the driving rotary member and the following rotary member, a separating slant surface disposed on a side of leading ends of sheets fed out by the sheet feeding rotary member for separating the sheets one by one, and rocking force generating device disposed on the rocking member for guiding a tensed side of the winding and hanging member in a direction away from the sheets, and for generating a rocking force, on the rocking member, which brings the sheet feeding ro

Abstract: A device for feeding sheets of a recording medium from a stack to an office machine, having movable elements which are moved by means of driven continuously rotating traction devices in the feed direction over the respective top sheet of the stack. The movable elements are supported by guide skids and are in contact with the top sheet under pressure to separate the top sheet from the second sheet of the stack beneath it and displace the top sheet with respect to the second sheet in the direction of feed. The movable elements each have at least one roller arranged across the direction of feed, mounted so it can rotate freely on a traction device.

Abstract: In a paper-leaves separating/supplying apparatus comprising a rotary separating/supplying belt, a vacuum suction device and a separating/supplying device, the vacuum suction device takes up one by one a plurality of paper leaves set together and conveyed as far as a position at which they come into contact with a belt surface of the separating/supplying belt so that the paper leaf is attached onto the belt surface and is fed toward the downstream side in accordance with the rotary motion of the separating/supplying belt. The belt surface of the separating/supplying belt is placed in a state perpendicular to a traveling plane of the paper leaves or in a state inclined toward the paper leaves.

Abstract: A method and system for automatically merging and attaching documents, such as photocopies of remittance checks or the like, to envelopes from which the documents originated is disclosed. The system uses a series of bins and conveyors to automatically retrieve, synchronize, merge and reassociate each document to its respective envelope.

Abstract: A feeder apparatus arranged on a side of a main body of an image forming apparatus is provided with a top door and a vertical door. The top door is provided in an opening defined above a sheet stacker, and the vertical door is provided in an opening defined on a side of the sheet stacker to enable an operator to replenish sheets inside the feeder apparatus. Switches are provided to detect as to whether the top door or the vertical door is opened. The feeder apparatus is constructed in such a manner that upward movement of the sheet stacker is suspended when the top door is detected to be opened and that upward and downward movement of the sheet stacker is suspended when the vertical door is detected to be opened.

Abstract: A method and apparatus for separating flexible flat objects from the top of a stack. The objects are lifted upward from the stack one at a time and separated therefrom by progressive adhesive action starting from the trailing end of the object in a transport direction. Once lifted by the adhesion device, the objects are transported in the transport direction by the transport device. The adhesion device may be magnetic for magnetizable articles or may be a suction device. Various techniques for moving suction and/or adhesion progressively along the object to be lifted in the transport direction are disclosed, including progressive application of suction, suction chamber arrangements for accomplishing that and the use of blown air to create a vacuum condition for lifting the sheets. The transport device might comprise a belt for moving the lifted objects. The transport of one object may be occurring while the next object is being lifted.

Abstract: A sheet feeder for advancing paper sheets one by one, has at least one traveling feeder belt whose one side is a feed plane and a stationary sheet restraining or retarding element that has a friction surface that faces towards and is spaced from the feed plane. The space between the friction surface and the feed plane forms a feed opening whose gap decreases in the feed direction. The feed belt runs on a belt support that is stationary, flat and rigid and extends along the greater part of the feed opening in the sheet transporting direction.

Abstract: A machine for processing documents has a document feeder adapted to selectively adjust document feed rate and interdocument separation. The document feeder has a feeder surface for feeding documents into the machine. There is a nip between the feeder surface and a separator surface. The end document of a stack is urged, singly into the nip and advanced therebeyond by the feeder surface. The separator surface restrains the remaining documents of the stack. A control adjusts the speed of the separator surface to be continuously variable and independent of the speed of said feeder surface, with the separator surface speed adjusted to optimize the document feed rate, optimize interdocument separation, and minimize damage to the documents being fed into the machine.

Abstract: An apparatus and method for supplying a plurality of box sheets comprising first belts which are movable in a predetermined direction, second belts which are also movable in the predetermined direction of the first belts, a shutter located above at least one of the first belts or the second belts, wherein the shutter is located so as to allow only one of the plurality of box sheets to be supplied beneath the shutter at a time, and a control system for controlling an operation of the second belts, wherein a coefficient of friction between the second belts and the box sheets is stronger than a coefficient of friction between the first belts and the box sheets.

Abstract: A sheet feeding mechanism comprising a feed belt assembly, a conveyor for feeding sheets to the feed belt assembly, the feed belt assembly having a belt driven first by a first drive roller, an idler roller assembly having an idler roller spaced from the first drive roller and driven by the first drive roller and a feed switch. The idler roller is mounted for pivotal movement toward and away from the feed switch whereby the feed switch mechanism will be activated by the idler roller assembly to permit sheets to be fed. The feed belt assembly comprises a take-up belt assembly and a delivery belt assembly and said conveyor moves sheets against the take-up assembly.

Abstract: An automated banking machine (10) identifies and stores documents such as currency bills deposited by a user. The machine then selectively recovers such documents from storage and dispenses them to other users. The machine includes a central transport (70) wherein documents deposited in a stack are unstacked, oriented and identified. Such documents are then routed to storage areas in recycling canisters (92, 94, 96, 98). When a user subsequently requests a dispense, documents stored in the storage areas are selectively picked therefrom and delivered to the user through an input/output area (50) of the machine.

Abstract: A belt (28) is moved into contact with a sheet (70) to be fed from the stack (18) under the control of a solenoid (48), which when energized causes pivoting of a crank mechanism (42) and an pulley (26) which supports the belt (28). The belt (28) frictionally engages the sheet (70) as to separate it from the stack (18) and move it into engagement with feed rollers (56) of a transport mechanism. The belt (28) is then retracted from the sheet (70) which is moved away from the stack (18) by the feed rollers (56). After a predetermined time period, the belt (28) is moved into contact with the next sheet of the stack (18) to be fed and the process is repeated until the desired number of sheets have been fed from the stack (18). The belt (28) is driven so that it rotates continuously during the pick operation and is brought to rest on retraction of the belt (28) after the final sheet has been picked from the stack (18).

Abstract: A belt supporting device includes a first support member for supporting a belt pulley, the member having a smaller width than that of the outer peripheral surface of the pulley, an endless belt wound on the pulley, a second support member for forming between the endless belt wound on the pulley and the second support member a space for extracting the endless belt in the axial direction of the pulley, and a positioning member located movably in and out of the space to maintain the space by entering the space and to thereby position the first and second support members.

Abstract: A separator belt for separating sheets from a stack is provided with symmetrically beveled or tapered edges. Such beveling or tapering eliminates the problem of sheet edges catching on an edge of the separator belt thereby reducing the probability of a misfeed of the sheet.

Abstract: An apparatus (1) for decollating juxtaposed flat objects (3) conveyed in form of vertical stacks is comprised of a conveyor (2) having a continuous loop traction mechanism (4) and a decollation unit (7) for removing the objects (3) individually from the front end of the stack (6) in a lateral direction, wherein the decollation unit (7) moves forward and backward, respectively, in relation to the front end of the stack (6), with the movements initiated by a transmitter (16) which is connected to the decollation unit (7) and faces the front end of the stack (6), based on the distance between the transmitter (16) and the front end of the stack (6).

Abstract: A belt displacement operation is periodically carried by the pick mechanism 11 of a sheet feeding apparatus, when the number of sheets fed has reaches a predetermined value. The motor 34 is driven in reverse for a predetermined time, so as to cause rotation of the belt 28 in the opposite direction to that during feeding. Since the pick pulley 26 is supported on the shaft 38 by means of a one-way clutch 40 so that it does not rotate during the reverse rotation of the belt 28, displacement of the belt 28 occurs relative to the pick pulley 26, so that in subsequent pick operations, a different portion of the belt 28 engages the stack 18 so as to pick a sheet, than had displacement of the belt 28 not occurred. This reduces the risk of localized portions of the belt 28 becoming more worn than others, due to more frequent engagement with the stack 18.