Patent ID: 12214983

The accompanying drawings are intended to depict embodiments of the present invention and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. Also, identical or similar reference numerals designate identical or similar components throughout the several views.

DETAILED DESCRIPTION

In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that have a similar function, operate in a similar manner, and achieve a similar result.

Referring now to the drawings, embodiments of the present disclosure are described below. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

A description is given below of an image forming system according to an embodiment of the present disclosure. In the present embodiment, the image forming system includes a sheet feeding device that is a sheet stacking device including a sheet feeder.FIG.1is a schematic view of an image forming system200according to the present embodiment. The image forming system200includes a sheet feeding device210, a pretreatment liquid application device220, an inkjet printer230, a drying device240, and a sheet output device250.

The sheet feeding device210supplies a sheet8as a recording medium such as cut paper to the pretreatment liquid application device220disposed downstream from the sheet feeding device210in a conveyance path of the sheet8. The pretreatment liquid application device220applies a pretreatment liquid to the sheet8. The pretreatment liquid prevents blurring and bleed-through of inkjet ink for printing. The pretreatment liquid application device220includes a sheet reverse path to reverse the sheet8. The pretreatment liquid is applied to a front side of the sheet8. Thereafter, the sheet8is reversed in the sheet reverse path, and the pretreatment liquid is also applied to a back side of the sheet8in double-sided printing.

The inkjet printer230as an image forming device discharges ink droplets onto the front side of the sheet8to which the pretreatment liquid has been applied by the pretreatment liquid application device220to form a desired image. The drying device240includes a dryer that dries the image on the front side of the sheet8formed by the inkjet printer230. In double-sided printing of the sheet8, the sheet8is reversed in a path from the drying device240back to the inkjet printer230. Then, the inkjet printer230discharges ink droplets to a front side (i.e., the back side before reversed) of the reversed sheet8to form a desired image, and the drying device240dries the image on the front side (i.e., the back side before reversed) of the sheet8. Thereafter, the sheet8is ejected to the sheet output device250.

FIGS.2A and2Bare schematic views of a sheet feeding tray100of the sheet feeding device210.FIG.2Ais a front view of the sheet feeding tray100, and the sheet8is fed from right to left inFIG.2A.FIG.2Bis a right side view of the sheet feeding tray100. The left-right direction inFIG.2Bis the front-back direction of the sheet feeding device210and a width direction of the sheet8.

The sheet feeding tray100includes a bottom portion6, a left housing10disposed on the downstream side in a feeding direction of the sheet8, a front side plate30disposed on the front side of the sheet feeding device210, a back side plate31disposed on the back side of the sheet feeding device210. Thus, the sheet feeding tray100has a box shape in which an upper portion and a right side are open inFIG.2A.

The sheet feeding tray100further includes a lift table4as a sheet stacker that moves up and down by a motor22. The sheet feeding tray100further includes position sensors20and21disposed above and below a range where the lift table4is movable in the vertical direction, respectively. When the lift table4moves upward, the position sensor20detects the upper surface of the lift table4, and the lift table4stops at a predetermined position based on the detection result of the position sensor20. Similarly, when the lift table4moves downward, the position sensor21detects the lower surface of the lift table4, and the lift table4stops at a predetermined position based on the detection result of the position sensor21.

The sheet feeding tray100further includes an end fence5and two side fences25aand25b. The lift table4has an end fence cutout4dthrough which the end fence5passes at the center in the width direction. The end fence cutout4dis an opening elongated in the feeding direction. The lift table4further has two side fence cutouts4bdisposed at the center in the feeding direction and spaced apart at a predetermined interval in the width direction. The side fence25apasses through the side fence cutout4bon the front side of the sheet feeding device210(the left side inFIG.2B), and the side fence25bpasses through the side fence cutout4bon the back side of the sheet feeding device210(the right side inFIG.2B).

The side fences25aand25bas a pair of sheet restrictors are disposed on both sides of the lift table4in the width direction of the sheet8(the front-back direction of the sheet feeding device210), and the positions of the pair of side fences25aand25bare moved in accordance with the sheet8set on the lift table4. The pair of side fences25aand25bare slidably supported by the bottom portion6and movable in opposite directions in the width direction of the sheet8in conjunction with each other by a connector26disposed above the bottom portion6. Each of the side fences25aand25bregulates the position of a side end of the sheet8in the width direction.

A side blower device125is disposed in each of the side fences25aand25b. The side blower device125includes a side blower125aand a side nozzle125bdisposed in an upper portion of each of the side fences25aand25b. The air taken in by the side blower125ais blown from the side nozzle125bonto a side face of an upper portion of a bundle of sheets8placed on the lift table4.

An edge blower device110is disposed in the left housing10. The edge blower device110includes an edge blower110aand an edge nozzle110bdisposed in an upper portion of a left side plate10aof the left housing10. The air taken in by the edge blower110ais blown from the edge nozzle110bonto a leading end of the upper portion of the bundle of sheets8placed on the lift table4. The upper sheet8of the bundle of sheets8is floated by the air blown from the edge nozzle110band the side nozzles125b.

The end fence5is disposed at a position corresponding to a trailing end of the sheet8. The end fence5serves as a trailing end restrictor that is movable to regulate the position of the trailing end of the sheet8. The end fence5regulates the position of the trailing end of the sheet8while the leading end of the sheet8contacts the left side plate10aof the left housing10. The end fence5is held by a guide rail16serving as a stay disposed at an upper portion of the sheet feeding tray100. The end fence5is movable along the guide rail16in a longitudinal direction of the guide rail16(i.e., the feeding direction).

The guide rail16is attached to a guide frame15having a frame shape that is along an edge of the box-shaped sheet feeding tray100. Specifically, the guide rail16is attached to the center in the width direction of an upstream side support of the guide frame15. The upstream side support extends in the width direction on the upstream side of the guide frame15in the feeding direction. The guide frame15is hinged on (swingably attached to) the back side plate31via a plurality of rotating hinges17which is rotatable. The end fence5moves along the guide rail16in the feeding direction and is secured at a desired position in the longitudinal direction of the guide rail16. That is, the end fence5is secured at the desired position in response to various sizes of the sheet8. The end fence5includes a rotating hinge18, which is rotatable, therein.

A sheet pressing member1is attached to the guide frame15to hold down the sheet8floated by the air from the edge nozzle110band the side nozzles125b. In the present embodiment, two sheet pressing members1are attached to the guide frame15at a predetermined interval on each of the front side and the back side with respect to the center in the width direction. The sheet pressing members1are detachably attached to the guide frame15. The guide frame15has multiple attachment positions to which the sheet pressing member1is attached. The attachment position for the sheet pressing member1can be changed in response to the width of the sheet8placed on the lift table4.

As the lift table4moves upward, the position sensor20detects that an uppermost sheet8of the bundle of sheets8stacked on the lift table4reaches a sheet feeding position, and the lift table4stops at the position in response to the detection of the position sensor20. A plurality of pickup belts3is faces the downstream side portion of the lift table4in the feeding direction. The pickup belt3has a plurality of suction holes, and the uppermost sheet8floated by the air blown from the edge nozzle110band the side nozzles125bis attracted onto the pickup belt3by a suction fan. Thus, when sheets8are stacked on the lift table4, the sheets8are fed one by one in the feeding direction by the pickup belt3. The pickup belt3, the suction fan, and a driver of the pickup belt3construct a sheet feeder.

FIG.3is a schematic view of the sheet feeding tray100, illustrating an example of movement of the guide frame15and the end fence5when the bundle of sheets8is set on the lift table4.FIG.4is a perspective view of the sheet feeding tray100that is pulled out from the device body of the sheet feeding device210.

When the sheet feeding device210detects that the sheet8runs out, the lift table4is lowered by the motor22, the position sensor21detects the position of the lift table4, and then the lift table4is stopped. The sheet feeding tray100is pulled out from the sheet feeding device210, and the guide frame15is swung upward around the plurality of rotating hinges17. At that time, the guide rail16secured to the guide frame15is also lifted together. The end fence5coupled to the guide rail16is moved and retracted in the vertical direction while being swung around the rotating hinge18, so that the end fence5does not hinder the bundle of sheets8from being set on the lift table4. The rotating hinge17applies torque to the guide frame15against only a direction in which the guide frame15is swung downward. Accordingly, when an operator sets the sheet8on the lift table4, the guide frame15is not automatically swung downward even if the operator does not hold the guide frame15by hand.

The side fences25aand25bare moved in response to the width of the sheet8set on the lift table4, and the guide frame15is swung downward around the rotating hinge17, thereby changing the angle of the guide frame15. The end fence5keeps a vertical posture around the rotating hinge18under gravity. Accordingly, when the guide frame15is swung downward, the end fence5returns to a predetermined position. Then, the end fence5and the side fences25aand25bare moved to suitable positions for the length and width of the sheet8set on the lift table4.

As illustrated inFIGS.2A,2B, and4, an upper housing130holding the sheet feeder and the position sensor20is disposed on the downstream side of the guide frame15in the feeding direction. An upstream end of the upper housing130in the feeding direction is disposed upstream from the left side plate10awith which the leading end of the sheet8on the lift table4is brought into contact. Accordingly, the bundle of sheets8is placed near the center of the lift table4in the feeding direction and slid on the lift table4to the downstream side in the feeding direction as indicated by arrow X inFIG.4, and the leading end of the bundle of sheets8is brought into contact with the left side plate10ato set the bundle of sheets8.

FIGS.5A and5Bare schematic views of the sheet feeding tray100in which the bundle of sheets8is placed near the center of the lift table4in the feeding direction.

Center portions of the lift table4in the feeding direction are cut out to form two openings, that is, the pair of side fence cutouts4b. Thus, the side fences25aand25bcan slide in the pair of side fence cutouts4bin the width direction to regulate the position of ends of the sheet8having the minimum usable width in the width direction. Accordingly, when the bundle of sheets8larger than the minimum usable width is placed near the center of the lift table4in the feeding direction, both sides of the leading end in the width direction of the lower sheet8of the bundle of sheets8(i.e., a leading widthwise ends of the sheet8) sag down under gravity and enter the side fence cutout4bas illustrated inFIGS.5A and5B. In such a state, if the bundle of sheets8on the lift table4is slid downstream in the feeding direction to bring the leading end of the sheet8into contact with the left side plate10aof the left housing10, the leading widthwise ends of the lower sheet8of the bundle of sheets8entering the side fence cutout4bmay bumps into a downstream edge of the side fence cutout4bin the feeding direction. As a result, the leading end of the lower sheet8of the bundle of sheets8may be folded or torn.

Further, when the lower sheet8of the bundle of sheets8contacts the downstream edge of the side fence cutout4bin the feeding direction, the bundle of sheets8is hindered from being slid downstream in the feeding direction. As a result, the bundle of sheets8may be set with a lower portion of the bundle of sheets8not in contact with the left side plate10a. As described above, when the bundle of sheets8is set with the lower portion of the bundle of sheets8not in contact with the left side plate10a(i.e., an improper stacking state that disturbs sheet feeding), the end fence5may not contact an upper trailing end of the bundle of sheets8. As a result, the sheet8may be fed with the position of the trailing end being not regulated by the end fence5, and the sheet8may move upstream in the feeding direction while being floated, resulting in unstable sheet feeding. Thus, the bundle of sheets8is required to be re-set on the lift table4.

Therefore, in the present embodiment, a stacking adaptor50is attached to the lift table4in the side fence cutout4bto support a portion of the bundle of sheets8facing the side fence cutout4b. With reference to the drawings, embodiments of the present disclosure are described in detail below.

FIG.6is a schematic view of the stacking adaptor50and the lift table4.FIG.7Ais a schematic plan view of the sheet feeding tray100before the stacking adaptor50is attached.FIG.7Bis a schematic plan view of the sheet feeding tray100to which the stacking adaptor50has been attached.

As illustrated inFIG.6andFIGS.7A and7B, the sheet feeding tray100includes support portions41and42at both ends of the side fence cutout4bin the feeding direction, respectively, to slidably support the stacking adaptor50in the width direction. The support portions41and42are located at a position lower than a surface of the lift table4that contacts the sheet8(i.e., a sheet stacking face). As a result, when the stacking adaptor50is supported by the support portions41and42, a sheet stacking face of a sheet stacking portion51of the stacking adaptor50and the sheet stacking face of the lift table4are located at substantially the same height.

As illustrated inFIG.7B, the stacking adaptor50is attached inside a sheet regulating position at which the side fences25aand25bregulate the position of the sheet8in the width direction in the side fence cutout4b. The number of stacking adaptors50to be attached to the lift table4is changed in response to a length of the side fence cutout4binside the side fence25ain the width direction (i.e., a widthwise length a). Specifically, when the widthwise length a is equal to or more than a transverse length b of the stacking adaptor50and less than twice the transverse length b (i.e., b≤a<2b), one stacking adaptor50is attached to the lift table4in each side fence cutout4b. When the widthwise length a is equal to or more than twice the transverse length b of the stacking adaptor50and less than three times the transverse length b (i.e.,2b≤a<3b), two stacking adaptors50are attached to the lift table4in each side fence cutout4b.

When the widthwise length a is equal to an integer multiple of the transverse length b of the stacking adaptor50, the stacking adaptor50can cover the side fence cutout4binside each of the side fences25aand25bwith almost no clearance in the width direction. When the widthwise length a is not equal to an integer multiple of the transverse length b of the stacking adaptor50, the stacking adaptor50does not cover the side fence cutout4bwithout any clearance. At this time, the stacking adaptor50is slid in the width direction to adjust the position of the stacking adaptor50in the width direction. For example, the positions of the stacking adaptors50in the width direction are adjusted so that the clearances between the stacking adaptors50are substantially the same. Thus, the stacking adaptor50supports the bundle of sheets8to prevent the leading widthwise ends of the lower sheet8of the bundle of sheets8from sagging down under gravity.

Note that, when the transverse length b of the stacking adaptor50is long, the clearance on both sides of the stacking adaptor50in the width direction becomes large if the widthwise length a is slightly smaller than an integer multiple of the transverse length b. As a result, the stacking adaptor50may not sufficiently support a bundle of sheets having low stiffness such as a thin sheet, and the leading widthwise ends of the bundle of sheets may sag down under gravity. On the other hand, when the transverse length b of the stacking adaptor50is short, the clearance on both sides of the stacking adaptor50in the width direction can be small even if the widthwise length a is slightly smaller than an integer multiple of the transverse length b. However, the number of the stacking adaptors50attached to the lift table4may increase when the bundle of sheets having the maximum usable size in the width direction is set on the lift table4, thereby increasing the work burden of an operator. Therefore, the transverse length b of the stacking adaptor50is set to a preferable length in consideration of influences when the bundle of sheets having low stiffness is set and when the bundle of sheets having the maximum usable size in the width direction is set.

Note that multiple stacking adaptors50having different transverse lengths may be provided, and the stacking adaptor50suitable for the widthwise length a of the side fence cutout4binside each of the side fences25aand25bmay be attached to the lift table4in the side fence cutout4b. As a result, regardless of the width of the sheet to be set, the stacking adaptor50can preferably cover the side fence cutout4binside each of the side fences25aand25bin the width direction. On the other hand, in the present embodiment, the multiple stacking adaptors50are attached to the lift table4. As a result, the multiple stacking adaptors50having the same configuration (e.g., the same transverse length) can be used for various size of the sheet8, thereby reducing the manufacturing cost of the sheet feeding device210.

As illustrated inFIG.6, the stacking adaptor50includes a body50aincluding the sheet stacking portion51on which the sheet8is placed and a fixing portion52, and a slider53. The sliders53are secured to the fixing portions52disposed near both ends of the lower surface of the sheet stacking portion51in the feeding direction. Each fixing portion52projects downward from the lower surface of the sheet stacking portion51and bends at a right angle in the feeding direction. Specifically, the fixing portion52disposed near the downstream end of the sheet stacking portion51in the feeding direction bends at a right angle toward the downstream side in the feeding direction, and the fixing portion52disposed near the upstream end of the sheet stacking portion51in the feeding direction bends at a right angle toward the upstream side in the feeding direction. The slider53is attached to a distal end of each of the fixing portions52. The sliders53secured to the fixing portions52are placed on the support portions41and42, and thus the stacking adaptor50is supported by the lift table4.

The body50aincluding the sheet stacking portion51and the fixing portion52is made of metal, and the slider53is made of resins having slidability, such as polyacetal and nylon. Since a supported portion of the stacking adaptor50supported by each of the support portions41and42is the slider53made of resins having slidability, the stacking adaptor50can be smoothly slid in the width direction of the sheet8, and the position of the stacking adaptor50in the width direction can be adjusted as desired.

The sheet stacking face of the sheet stacking portion51is set so as not to be lower (i.e., a height difference h<0) than at least a sheet stacking face of a leading end support4aof the lift table4. That is, the height of the sheet stacking face of the sheet stacking portion51is set to be equal to or higher (i.e., the height difference h≥0 as illustrated inFIG.6) than the height of the sheet stacking face of the leading end support4aof the lift table4, thereby preventing the leading end of the lowermost sheet8of the bundle of sheets8from being caught by an upstream edge of the leading end support4ain the feeding direction when the bundle of sheets8placed on the lift table4is slid downstream in the feeding direction to set the bundle of sheets8in the sheet feeding tray100.

More preferably, the height of the sheet stacking face of the sheet stacking portion51is the same as the height of the sheet stacking face of the lift table4(i.e., the height difference h=0). When the height of the sheet stacking face of the sheet stacking portion51is set to the same as the height of the sheet stacking face of the lift table4, the portion of the bundle of sheets8supported by the stacking adaptor50is not pushed up by the stacking adaptor50. As a result, the bundle of sheets8can be stably stacked in the sheet feeding tray100, and the sheet feeding device210can stably feed the sheet8from the bundle of sheets8.

Further, a gap d between the leading end support4aand the sheet stacking portion51is minimized to prevent the leading end of the lowermost sheet8of the bundle of sheets8from entering the gap when the bundle of sheets8is slid downstream in the feeding direction. Specifically, the gap d is set such that, when a sheet having low stiffness such as a thin sheet is placed on the lift table4and slid downstream in the feeding direction, and the leading end of the sheet passes through the gap d, the leading end of the sheet does not sag down and is not caught by the upstream edge of the leading end support4ain the feeding direction. Accordingly, when the bundle of sheets8placed on the lift table4is slid downstream in the feeding direction, the leading end of the lowermost sheet8of the bundle of sheets8is not caught by the upstream edge of the leading end support4ain the feeding direction, and thus the bundle of sheets8can be reliably set in the sheet feeding tray100.

When the body50aof the stacking adaptor50includes the supported portions supported by the support portions41and42of the lift table4, and the stacking adaptor50is made of one material, the sheet stacking face of the sheet stacking portion51may be lower than the sheet stacking face of the leading end support4aof the lift table4on which the leading end of the sheet8is placed due to manufacturing tolerances.

On the other hand, in the present embodiment, the slider53is made of another material different from the material of the body50a, enabling to adjust the height difference h to 0 or more with the slider53attached to the body50a. In addition, the body50acan be supported by the support portions41and42at a position shifted downstream in the feeding direction with the slider53attached to each fixing portion52. That is, the short slider53is attached to the fixing portion52on the downstream side in the feeding direction, thereby positioning the downstream end of the short slider53upstream from the leading end of the sheet stacking portion51in the feeding direction. On the other hand, the long slider53, which is longer than the short slider53, is attached to the fixing portion52on the upstream side in the feeding direction, thereby positioning the upstream end of the long slider53upstream from the tailing end of the sheet stacking portion51in the feeding direction. As a result, the body50aof the stacking adaptor50can be shifted downstream in the feeding direction when supported by the support portions41and42. Thus, the gap d between the sheet stacking portion51and the leading end support4acan be minimized by the slider53to be attached.

FIGS.8A to8Care schematic views of the slider53secured to the fixing portion52as one example.FIG.8Ais a schematic view of the fixing portion52and the slider53as viewed in the feeding direction.FIG.8Bis a schematic view of the fixing portion52and the slider53as viewed from above.FIG.8Cis a schematic view of the fixing portion52and the slider53as viewed in the width direction. AlthoughFIGS.8A to8Cillustrate the fixing portion52on the downstream side in the feeding direction, the fixing portion52on the upstream side in the feeding direction has the same configuration.

A distal portion52aof the fixing portion52illustrated inFIG.8Bextends to one side and the other side in the width direction, and the slider53is attached to each end of the distal portion52ain the width direction. The distal portion52aof the fixing portion52has two through holes52bat a predetermined interval in the width direction, and the slider53has a projection53athat fits into the through hole52b.

The slider53includes a groove53b, the projection53a, and a sliding portion53c. A lower face of the sliding portion53cslides against the support portion41(seeFIG.7B). The projection53ais disposed on an upper face of the sliding portion53c, and the groove53bis disposed at one end of the sliding portion53cand recessed in the width direction. The end of the distal portion52aof the fixing portion52in the width direction fits into the groove53b.

When the slider53is moved in a direction indicated by the blank arrow inFIGS.8A and8Bto fit the end of the distal portion52ain the width direction into the groove53bof the slider53, the sliding portion53cof the slider53is elastically deformed and the projection53aclimbs up on the distal portion52a. As the slider53is further moved in the direction indicated by the blank arrow inFIGS.8A and8B, the distal portion52ais inserted into the groove53b, and the end of the distal portion52ain the width direction contacts the bottom of the groove53b, and at the same time, the projection53aenters the through hole52bof the distal portion52a. Thus, the slider53is attached to the fixing portion52by snap-fit. Since the slider53is snap-fitted to the fixing portion52, the slider53can be easily replaced, thereby easily adjusting the height difference h.

FIGS.9A to9Bare schematic views of the slider53secured to the fixing portion52as another example. InFIGS.9A and9B, the slider53is secured to the fixing portion52with an adhesive S. Specifically, the adhesive S is applied to the upper surface of the sliding portion53c, and the sliding portion53cis bonded and secured to the distal portion52aof the fixing portion52. As described above, since the slider53is bonded and secured to the fixing portion52of the body50awith the adhesive S, the slider53and the fixing portion52have a simple configuration as compared to when the slider53is snap-fitted. The method of securing the slider53to the fixing portion52is not limited to the above examples, and various known methods such as a double-sided tape can be employed.

FIG.10Ais a schematic view of the sheet feeding tray100in which a bundle of wide sheets8is set, andFIG.10Bis a schematic view of the sheet feeding tray100in which the bundle of narrow sheets8is set. As illustrated inFIG.10A, when the bundle of wide sheets8is set, three stacking adaptors50are attached in each side fence cutout4b. Then, the stacking adaptors50are slid in the width direction to adjust the positions of the stacking adaptors50with the uniform clearance therebetween in the width direction.

On the other hand, as illustrated inFIG.10B, when the bundle of narrow sheets8is set, one stacking adaptor50is attached in each side fence cutout4b. Then, the stacking adaptor50is slid in the width direction to adjust the position of the stacking adaptor50with the uniform clearance on both sides thereof in the width direction.

When the bundle of wide sheets8is set as illustrated inFIG.10A, the sheet pressing member1is shifted outward in the width direction as compared to when the bundle of narrow sheets8is set as illustrated inFIG.10B. As described above, since the sheet pressing member1is shifted to a preferable position corresponding to the width of the sheet8, the sheet pressing member1can maintain the posture of the floated uppermost sheet8even when the sheet of any width is used.

FIGS.11A and11Bare schematic views of the sheet feeding tray100according to the present embodiment when the bundle of sheets8is set in the sheet feeding tray100. In preparation, the side fences25aand25bare slid to positions corresponding to the width of the sheet8to be set in the direction indicated by arrow B inFIG.11B. Next, the suitable number of stacking adaptors50corresponding to the widthwise length of a portion of the side fence cutout4binside each of the side fences25aand25bin the width direction are attached to the lift table4. Then, the stacking adaptors50are slid in the width direction to adjust the position of the stacking adaptors50in the width direction.

Next, as described above, the bundle of sheets8is placed near the center of the lift table4in the feeding direction, and the bundle of sheets8is slid downstream in the feeding direction indicated by arrow A inFIGS.11A and11Bso as to bring the leading end of the sheet8into contact with the left side plate10a.

In the present embodiment, the stacking adaptor50supports a portion of the bundle of sheets8facing the side fence cutout4b. As a result, the leading widthwise ends of the lower portion of the bundle of sheets8does not sag down under gravity. Further, in the present embodiment, the height of the sheet stacking face of the sheet stacking portion51of the stacking adaptor50is equal to or higher than the height of the sheet stacking face of the leading end support4aof the lift table4. Accordingly, the leading widthwise ends of the lower portion of the bundle of sheets8is not caught by the upstream edge of the leading end support4aof the lift table4in the feeding direction, and thus the bundle of sheets8can be slid in the feeding direction so that the leading end of the bundle of sheets8contacts the leading end support4a. As a result, the leading end of the lower sheet8of the bundle of sheets8is not folded or torn, and the leading end of the bundle of sheets8can be brought into contact with the left side plate10a.

Further, the lower sheet8of the bundle of sheets8is not hindered from being slid in the direction indicated by arrow A inFIGS.11A and11B, and all the sheets8of the bundle of sheets8can be brought into contact with the left side plate10a, thereby preventing the improper stacking state that disturbs sheet feeding. As a result, the end fence5reliably contacts the entire trailing end of the bundle of sheets8, and the sheet8does not move upstream in the feeding direction while being floated, resulting in stable sheet feeding. Since the stacking state does not disturb sheet feeding, re-setting of the bundle of sheets8is unnecessary.

Further, in the present embodiment, the gap d between the downstream end of the stacking adaptor50and the upstream edge of the leading end support4ain the feeding direction is minimized. Thus, when the bundle of sheets8is slid upstream in the feeding direction, the leading end of the lowermost sheet8of the bundle of sheets8does not enter the gap d. As a result, the lower sheet8of the bundle of sheets8is reliably prevented from being folded or torn.

In another embodiment, the stacking adaptor50may be made of resin having slidability (e.g., a slidable resin such as polyacetal and nylon) and may be formed as a single-piece body.FIGS.12A to12Care schematic views of the stacking adaptor50made of resin having slidability.

The stacking adaptor50illustrated inFIGS.12A to12Cincludes a supported portion54having substantially the same shape as the fixing portion52of the stacking adaptor50according to the above-described embodiment. The supported portion54has a sliding surface54bthat slides against the support portion41(or42) of the lift table4on a distal portion54aof the supported portion54. Thus, the stacking adaptor50made of resin having slidability does not have a separated slider such as the slider53, thereby reducing the number of components to construct the sheet feeding device210.

The embodiments described above are just examples, and the various aspects of the present disclosure attain respective effects as follows.

Aspect 1

A sheet stacking device such as the sheet feeding device210includes a sheet stacker such as the lift table4, a pair of sheet restrictors such as the pair of side fences25aand25b, and a stacking adaptor such as the stacking adaptor50. The sheet stacker has a first sheet stacking face on which a bundle of sheets is stacked. The sheet stacker includes a leading end support such as the leading end support4ato support a leading end of the bundle of sheets in a feeding direction of the bundle of sheets by a second sheet stacking face and a pair of cutouts such as the pair of side fence cutouts4bdisposed upstream from the leading end support. The pair of sheet restrictors slide in the pair of cutouts in a width direction orthogonal to the feeding direction to regulate a position of the bundle of sheets on the sheet stacker in the width direction. The stacking adaptor is detachably attached to the sheet stacker to cover the pair of cutouts. The stacking adaptor has a third sheet stacking face to support a portion of the bundle of sheets disposed at the pair of cutouts.

When the bundle of sheets is set from the upstream side in the feeding direction of the sheet feeding device, the bundle of sheets is placed near the center of the sheet stacker such as the lift table4in the feeding direction, and then slid downstream on the sheet stacker in the feeding direction so that the leading end of the bundle of sheets contacts the left side plate10aon the downstream side in the feeding direction, thereby setting the bundle of sheets in the sheet feeding device. When the bundle of sheets is placed near the center of the sheet stacker in the feeding direction, if both the leading widthwise ends of the bundle of sheets face the cutout such as the side fence cutout4b, the leading widthwise ends of the lower sheet of the bundle of sheets may sag down under gravity and enter the cutout (seeFIGS.5A and5B). When both the leading widthwise ends of the lower sheet of the bundle of sheets enter the cutout, if the bundle of sheets is slid downstream in the feeding direction, the leading widthwise ends of the lower sheet of the bundle of sheets may be caught by the downstream edge of the cutout in the feeding direction, and the lower sheet of the bundle of sheets may be folded or torn.

On the other hand, in Aspect 1, the stacking adaptor50attached in the cutout supports the portion, which faces the cutout, of the bundle of sheets stacked on the sheet stacker. As a result, when the bundle of sheets is placed near the center of the sheet stacker in the feeding direction, both the leading widthwise ends of the lower sheet of the bundle of sheets are supported by the stacking adaptor50and prevented from sagging down under gravity. With this configuration, when the bundle of sheets on the sheet stacker is slid downstream in the feeding direction, both the leading widthwise ends of the lower sheet of the bundle of sheets are prevented from being caught by the downstream edge of the cutout in the feeding direction, and from being folded or torn.

Further, since the stacking adaptor50is detachably attached to the sheet stacker in the cutout, the stacking adaptor50to be attached in the cutout can be easily replaced in response to the width of the bundle of sheets set on the sheet stacker.

Aspect 2

In Aspect 1, the height of the sheet stacking face of the stacking adaptor50(i.e., the third sheet stacking face) is equal to or higher than the sheet stacking face of the leading end support4a(i.e., the second sheet stacking face).

With this configuration, as described in the above embodiment, when the bundle of sheets is placed near the center of the sheet stacker such as the lift table4in the feeding direction and slid downstream in the feeding direction, the portion of the lowermost sheet of the bundle of sheets supported by the stacking adaptor50is not caught by the upstream edge of the leading end support4ain the feeding direction. As a result, the lower sheet of the bundle of sheets is prevented from being folded or torn.

Aspect 3

In Aspect 2, the sheet stacking face of the stacking adaptor50(i.e., the third sheet stacking face) is at the same height as the sheet stacking face of the sheet stacker such as the lift table4(i.e., the first sheet stacking face).

With this configuration, the portion of the bundle of sheets supported by the stacking adaptor50is not pushed up by the stacking adaptor50. As a result, the bundle of sheets can be stably stacked in the sheet stacking device, and the sheet stacking device can stably feed the sheet from the bundle of sheets.

Aspect 4

In any one of Aspects 1 to 3, the sheet stacking device further includes a slider configured to adjust a gap d between a downstream end of the stacking adaptor50and the leading end support4ain the feeding direction.

With this configuration, when the bundle of sheets stacked on the sheet stacker is slid downstream in the feeding direction, the leading end of the lowermost sheet of the bundle of sheets is prevented from entering the gap d between the downstream end of the stacking adaptor50and the leading end support4aand from being caught by the leading end support4a. As a result, the lower sheet of the bundle of sheets is prevented from being folded or torn.

Aspect 5

In any one of Aspects 1 to 4, the stacking adaptor50is slidable in the width direction to cover the pair of cutouts such as the pair of side fence cutouts4b.

With this configuration, as described in the above embodiment, the position of the stacking adaptor50is adjustable in the width direction. Even if the stacking adaptor50does not completely cover the portion of the cutout such as the side fence cutout4binside the sheet restrictor such as the side fences25aand25bin the width direction, the stacking adaptor50can sufficiently support the lower sheet of the bundle of sheets so that the lower sheet of the bundle of sheets does not sag down.

Aspect 6

In Aspect 5, the sheet stacker further includes a support portion such as the support portions41and42configured to support the stacking adaptor50in the pair of cutouts such as the side fence cutouts4b, and the stacking adaptor50includes a body such as the body50ahaving the third sheet stacking face and a slider such as the slider53slidably contacting the support portion.

With this configuration, as described in the above embodiment, the stacking adaptor50can be smoothly slid on the support portions41and42in the width direction to adjust the position of the stacking adaptor50in the width direction as desired.

In addition, since the slider is a separated component from the body, the height of the sheet stacking face of the stacking adaptor50and the gap d between the stacking adaptor50and the leading end support4acan be adjusted by the slider attached to the body50a.

Aspect 7

In Aspect 6, the slider53is snap-fitted to the body50a.

With this configuration, the slider53can be easily attached to and detached from the body50aof the stacking adaptor50.

Aspect 8

In Aspect 6, the slider53is bonded to the body50a.

With this configuration, the slider53can be secured to the body50awith a simple configuration as compared to when the slider53is snap-fitted.

Aspect 9

In Aspect 5, the stacking adaptor is made of a slidable resin.

With this configuration, as described with reference toFIGS.12A to12C, the stacking adaptor can be formed as a single-piece body without the separated slider, thereby reducing the number of components to construct the sheet stacking device.

Aspect 10

In any one of Aspects 1 to 9, the stacking adaptor50includes multiple stacking adaptors50attachable to the sheet stacker to cover the pair of cutouts such as the side fence cutouts4b.

With this configuration, as described in the above embodiment, the number of the stacking adaptors50attached to the sheet stacker in the cutout can be changed in response to the width of the bundle of sheets stacked on the sheet stacker such as the lift table4. As a result, when the bundle of wide sheets is stacked on the sheet stacker, the number of the stacking adaptors50attached in the cutout is increased to allow the stacking adaptors50to sufficiently support the bundle of wide sheets. On the other hand, when the bundle of narrow sheets is stacked on the sheet stacker, the number of the stacking adaptors50attached in the cutout is decreased to allow the sheet restrictor such as the side fences25aand25bto contact the side face of the bundle of sheets

Aspect 11

An image forming system includes an image forming device to form an image on a sheet and the sheet stacking device according to any one of Aspects 1 to 10 to feed the sheet from the bundle of sheets to the image forming device.

With this configuration, the sheet stacked on the sheet stacker can be fed to the image forming device to form an image on the sheet.

As described above, according to the present disclosure, the lower sheet of the bundle of sheets is prevented from being folded or torn.

The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention.