Patent ID: 12240723

DETAILED DESCRIPTION

Summary of Exemplary Embodiments

FIG.1Ais a rough diagram of a medium feeding device according to an exemplary embodiment of the present disclosure.

InFIG.1A, the medium feeding device includes a container member1that accommodates sheet media S, a discharging member2that is disposed further than the media S accommodated in the container member1in a discharging direction in which the media S are discharged to discharge the media S one by one, a hand-over member3that is disposed above the container member1at a position closer to the discharging member2to suck the media S accommodated in the container member1with air and pass the media S to the discharging member2, a floating device4that is disposed on a side of the media S accommodated in the container member1to blow air to an upper area of a side end surface of the media S and float the media S while an upper portion of the media S is separated, and an auxiliary suction member5that is disposed above the container member1and on a side of the hand-over member3opposite to a side closer to the discharging member in the discharging direction in which the media S are discharged, to suck the media S accommodated in the container member1with air, wherein the auxiliary suction member5is disposed closer to the hand-over member3than to an end portion of the media S accommodated in the container member1opposite to an end portion of the media S located closer to the discharging member2.

The medium feeding device of this type is installed in a medium processing device including a processing member not illustrated that performs a predetermined process on the media S, and used as a device that embodies a function of feeding the media S to the processing member.

In this case, in addition to an image forming member that forms images on the media S, examples of the processing member include a device that performs various processing on media such as forming holes in media, cutting media, sorting media, or folding media.

In such as a technical member, the container member1generally includes a mount that receives the media S thereon, and the mount is usually supported by a hoist mechanism to be movable upward and downward. In an aspect of accommodating the media S of various different sizes, the container member1includes side guides and a rear guide.

Examples of the discharging member2include a wide range of members that discharge media S, and a typical example of the discharging member2includes a pair of discharging rollers or a set of a discharging roller and a discharging belt.

Any member, such as a transport shuttle (a vacuum head) or a transport belt, that sucks media one by one, passes the media to the discharging member2, and returns to the initial position may be appropriately selected as the hand-over member3.

Any member that blows air to the upper area of the accommodated media S from a side of the container member1(including the front or rear side in a medium discharging direction besides a side in a width direction crossing the medium discharging direction) may be selected as the floating device4.

The auxiliary suction member5may be disposed at any position on a side of the hand-over member3opposite to the side closer to the discharging member in the discharging direction in which the media S are discharged, and may have one or more air suction ports.

Particularly, in the present example, the auxiliary suction member5is to be disposed closer to the hand-over member3than to an end portion of the media S accommodated in the container member1opposite to an end portion of the media S located closer to the discharging member2.

In this case, “being located closer to the hand-over member3” indicates being located immediately close regardless of being in contact or not in contact with the hand-over member3. Thus, in an operation of passing the media S to the hand-over member3, the auxiliary suction member5may be fixed while being separated from the hand-over member3or may move together with the hand-over member3. In an aspect where the auxiliary suction member5is disposed while being not in contact with the hand-over member3, the auxiliary suction member5may be located closer to the hand-over member3than to an end portion of the media S accommodated in the container member1opposite to an end portion of the media S located closer to the discharging member2.

When the auxiliary suction member5is thus disposed closer to the hand-over member3, regardless of when the media S accommodated in the container member1are in the inclined position, the inclination of the media S between the auxiliary suction member5and the hand-over member3that are located close to each other is reduced when the auxiliary suction member5performs auxiliary suction of the media S (specifically, an uppermost medium S1). This structure is effective for the hand-over member3to stabilize air suction of the media S.

Although the air suction force of the auxiliary suction member5may be selected as appropriate, the air suction force is to be sufficient for assisting the hand-over member3in performing the medium air-suction operation.

Typical or preferable aspects of a medium feeding device according to the present embodiment will be described now.

First, as a typical aspect of the auxiliary suction member5, as illustrated inFIG.1A, the auxiliary suction member5sucks with air the media S (more specifically, S1) accommodated in the container member1earlier than the hand-over member3performs air suction. In this example, the auxiliary suction member5performs air suction on the media S and holds the media S earlier than the hand-over member3does, and thus the media S are brought closer to the hand-over member3. This structure accordingly facilitates the hand-over member3to perform air suction of the media S, and is thus preferable.

As illustrated inFIG.1A, as another typical aspect of the auxiliary suction member5, when the position where the hand-over member3is capable of performing an air-suction operation on the uppermost medium S1is defined as a medium reference height FC on condition that the media S with a substantially uniform thickness are accommodated in the container member1in a substantially horizontal position, the auxiliary suction member5sucks with air the media S at a position lower than the medium reference height FC. In this example, when, for example, the media S in the container member1is inclined in the accommodated position and when the uppermost medium S1of the media S facing the suction surface of the hand-over member3is located lower than the medium reference height FC, the uppermost medium S1floated by the hand-over member3may fail to be sucked with air regardless of when the upper portion of the media S is separated and floated by the floating device4. However, in this example, the auxiliary suction member5located close to the hand-over member3sucks with air the medium S1located lower than the medium reference height FC. Thus, the auxiliary suction member5raising the medium S1to near the medium reference height FC effectively assists the hand-over member3in air suction of the medium S1.

Another preferable aspect of the auxiliary suction member5starts the air-suction operation before the hand-over member3performs the air-suction operation. For example, in a first aspect, when the auxiliary suction member5starts the air-suction operation at this manner, the auxiliary suction member5performs air suction of the media S earlier than the hand-over member3does. In second and third aspects, the timing when the auxiliary suction member5starts the air-suction operation includes the same timing as when the hand-over member3starts the air-suction operation. However, when the auxiliary suction member5performs the air-suction operation earlier than the hand-over member3, the auxiliary suction member5sucks the media S with air to hold the media S when the hand-over member3is to suck the media S with air. This performance is preferable in that it facilitates the air suction of the media S performed by the hand-over member3.

As a typical aspect of the timing of the air-suction operation performed by the auxiliary suction member5, the auxiliary suction member5starts the air-suction operation earlier than the hand-over member3, and finishes the air-suction operation after the hand-over member3starts the air-suction operation. In this example, the auxiliary suction member5may finish the air-suction operation on the media S at the same timing as when the hand-over member3starts the air-suction operation. In this case, the media S sucked with air by the auxiliary suction member5is handed over to the hand-over member3and sucked with air by the hand-over member3. In view of a smooth handover of the air-suction operation from the auxiliary suction member5to the hand-over member3, preferably, the auxiliary suction member5starts the air-suction operation earlier than the hand-over member3, and finishes the air-suction operation after the hand-over member3starts the air-suction operation, so that the air-suction operation is performed by both the auxiliary suction member5and the hand-over member3for a predetermined period while being handed over from the auxiliary suction member5to the hand-over member3.

As a typical aspect of the auxiliary suction member5that performs the air-suction operation, as illustrated inFIGS.1A and1B, the auxiliary suction member5is continuous to an air suction member6through a flow-path forming portion7, and an opening-degree adjusting member8that opens or shuts the flow path formed from the flow-path forming portion7is disposed in the flow-path forming portion7.

In this example, the air suction member6may be provided separately from the air suction member used by the hand-over member3for the air-suction operation, or may be used in common with the air suction member used by the hand-over member3for the air-suction operation.FIG.32shows an exemplary embodiment of a configuration whereby the air suction member6A is provided separately from the air suction member6B used by the hand-over member3for the air-suction operation.

In this case, as a typical aspect of the air suction member6for common use, for example, the flow-path forming portion7includes a first flow-path forming portion that connects the air suction member6and the hand-over member3to each other, and a second flow-path forming portion that diverges from the first flow-path forming portion to be connected to the auxiliary suction member5. The opening-degree adjusting member8includes a first opening-degree adjusting portion that is disposed at a portion of the first flow-path forming portion closer to the hand-over member3than a diverging portion leading to the second flow-path forming portion to adjust the degree of opening, and a second opening-degree adjusting portion that is disposed at the second flow-path forming portion to adjust the degree of opening (refer to a third exemplary embodiment).

As another typical aspect of the air suction member6for common use, the flow-path forming portion7includes a first flow-path forming portion that connects the air suction member6and the hand-over member3to each other, and a second flow-path forming portion that diverges from the first flow-path forming portion to be connected to the auxiliary suction member5, and the opening-degree adjusting member8includes a common-use opening-degree adjusting portion that is disposed at the diverging portion between the first flow-path forming portion and the second flow-path forming portion to divide the suction air among the auxiliary suction member5and the hand-over member3(refer to modification examples 3-1 to 3-3).

As a typical control method of the air-suction operation performed by the auxiliary suction member5, the auxiliary suction member5starts the air-suction operation after the opening-degree adjusting member8switches to a first opening-degree mode that enables only the air-suction operation performed by the auxiliary suction member5, and the hand-over member3starts the air-suction operation after a specific time period has passed from when the auxiliary suction member5starts the air-suction operation after the opening-degree adjusting member8switches to a second opening-degree mode that enables the air-suction operation performed by the hand-over member3in addition to the air-suction operation performed by the auxiliary suction member5.

As a typical aspect of the auxiliary suction member5, the auxiliary suction member5includes a moving duct having a lower end portion vertically movable, and the auxiliary suction member5moves the moving duct to a predetermined lower target position, and starts the air-suction operation.

Preferably, the target position is located lower than the medium reference height FC. For example, assume a case where the media S accommodated in the container member1have a thickness that varies between the opening and the bottom such as envelopes. In this case, when the media S formed from the envelopes are piled and accommodated in the container member1, as illustrated inFIG.1A, the media S may be inclined in the container member1.

In this state, when the uppermost one of the media S is denoted with S1, the lower portion of the medium S1in the inclined position is located lower than the medium reference height FC. Particularly, when the portion of the medium S1in the inclined position lower than the medium reference height FC faces the hand-over member3, regardless of when the uppermost medium S1is floated by the floating device4, the lower portion of the medium S1in the inclined position may fail to arrive at the medium reference height FC. For example, when only the hand-over member3performs the air-suction operation, the medium S1may be unstably sucked with air.

In such a state, in the present exemplary embodiment, the auxiliary suction member5is disposed close to the hand-over member3on the side opposite to the side closer to the discharging member2in the discharging direction in which the media S are discharged. Regardless of when the uppermost medium S1is disposed in an inclined position while having a portion closer to the hand-over member3lowered, the portion of the inclined medium S1facing the auxiliary suction member5is located higher than the portion of the inclined medium S1facing the hand-over member3. Thus, the distance between the auxiliary suction member5and the medium S1is shorter than the distance between the hand-over member3and the medium S1, and accordingly, the auxiliary suction member5sucks the medium S1with air and holds the medium S1earlier than the hand-over member3does, and assists the hand-over member3in air suction of the medium S1.

As a preferable aspect of the auxiliary suction member5including a moving duct, the auxiliary suction member5includes a vertically expandable moving duct, extends the moving duct to a target position under its own weight, and starts the air-suction operation.

As another aspect, the auxiliary suction member5includes a vertically movable moving duct and a driving member that vertically moves the moving duct, moves the moving duct to a target position, and starts the air-suction operation.

As another preferable aspect of the auxiliary suction member5, the auxiliary suction member5includes a moving duct with a lower end portion vertically movable, and the moving duct includes an absorber that absorbs an excess of movement of the lower end portion. In this example, examples of the absorber include an elastic spring and an expandable divided duct structure. Addition of such an absorber prevents the medium S1from being damaged regardless of when the medium S1is hardly hit by the auxiliary suction member5, and is thus effective to stably perform the air-suction operation.

Although the air suction area of the auxiliary suction member5is not appropriately selected, to provide a simple structure, the air suction area may be smaller than the air suction area of the hand-over member3.

The auxiliary suction member5may preferably be installed at a substantially center of the media S in the width direction crossing the discharging direction in which the media S are discharged when, for example, the media S are accommodated while being deformed in a recessed shape along the width.

First Exemplary Embodiment

Hereinbelow, the present disclosure will be further described in detail based on exemplary embodiments illustrated in appended drawings.

FIG.2is a diagram of the entire structure of a medium processing device according to a first exemplary embodiment.

Entire Structure of Medium Processing Device

InFIG.2, a medium processing device10includes a medium feeding device11that feeds sheet media one by one, and a processing unit20that serves as a processing member that performs a predetermined process on the media fed from the medium feeding device11.

In the present example, the processing unit20includes an image forming unit21that forms images on the media. The image forming unit21employs various image forming methods such as an electrophotographic system or an inkjet printing method. The processing unit20includes an importing path22along which media fed from the medium feeding device11are transported to the image forming unit21, and an exporting path23along which media undergoing image formation at the image forming unit21are transported out of the processing unit20. In this example, the processing unit20separately includes a built-in medium feeder24below the image forming unit21. Media from the medium feeder24are also fed to the image forming unit21through a feed transport path25. Importing rollers26are disposed at the entrance of the importing path22. An appropriate number of transporting members are disposed at the importing path22, the exporting path23, and the feed transport path25.

Entire Structure of Medium Feeding Device

In this example, as illustrated inFIG.2andFIG.3, the medium feeding device11includes a housing12that accommodates media. The housing12includes an upper drawer13and a lower drawer14vertically arranged in two stages to be drawable outward, and a manual feeder15disposed at an upper portion of the housing12to allow media to be manually fed therethrough. The medium feeding device11also includes a relay unit16on the side of the housing12closer to the processing unit20. The relay unit16relays media fed from the upper drawer13, the lower drawer14, and the manual feeder15to transport the media to the processing unit20.

In this example, both the upper drawer13and the lower drawer14accommodate a large number of media and feed the media one by one. The relay unit16includes a first transport path17aalong which the media fed from the upper drawer13are transported, a second transport path17balong which the media fed from the lower drawer14are transported, and a third transport path17calong which the media fed from the manual feeder15are transported. An appropriate number of transport rollers18are disposed at the first to third transport paths17ato17c. A merging transport path17dthat is continuous with an outlet port17eleading to the processing unit20is disposed at the exit side of each of the first to third transport paths17ato17c. Discharge rollers19are disposed at the merging transport path17d. The upper drawer13and the lower drawer14respectively include pulls13aand14ato be drawable to the near side.

Structure Example of Upper Drawer (Lower Drawer)

In this example, the upper drawer13and the lower drawer14have substantially the same structure. Hereinbelow, the upper drawer13is described as an example.

In this example, as illustrated in, for example,FIG.4, the upper drawer13includes a container30serving as a container member that accommodates sheet media, discharging rollers40serving as a discharging member disposed further than the media accommodated in the container30in a discharging direction in which the media are discharged to discharge the media one by one, a vacuum head50disposed above the container30to serve as a hand-over member that sucks the media accommodated in the container30with air and passes the media to the discharging rollers40, a floating mechanism70that is disposed on a side of the media accommodated in the container30in a direction crossing the discharging direction in which the media is discharged, the floating mechanism70serving as a floating device that blows air to the side of the media to float the media while separating the upper area of the media, and an air handling mechanism80disposed further than the media accommodated in the container30in a discharging direction in which the media are discharged, the air handling mechanism80blowing air to separate an upper medium floated by the floating mechanism70from a medium located below the upper media.

Container

In this example, as illustrated inFIG.4andFIG.5, the container30includes a receiving bottom plate31that receives media of various sizes, side guides32(more specifically,32aand32b) disposed on the sides, in a width direction crossing the discharging direction, of media of various sizes placed on the receiving bottom plate31to serve as side guide members that fix and guide the side position of the media, an end guide33disposed at a rear side opposite to the side closer to the discharging member in the discharging direction in which the media loaded on the receiving bottom plate31are discharged to serve as a rear guide member that fixes and guides the rear position of the media, and a partitioning plate34that defines the position of the media loaded on the receiving bottom plate31in the discharging direction in which the media are discharged.

In this example, the container30may be designed in accordance with the size of media to be used. However, in view of high versatility, preferably, a normal-size medium is to be mainly used. In this case, examples of the normal-size medium include media with a longitudinal dimension up to 488 mm. An example of media with such a size corresponds to media of A3 size or smaller in Japanese Industrial Standards (JIS).

In this example, examples of medium include, in addition to media with a uniform thickness, a medium with an uneven thickness such as an envelope that varies in thickness in the discharging direction.

In this example, the side guides32are movable in the width direction of the receiving bottom plate31, and fixed in a predetermined fixed position. The end guide33is movable in the discharging direction of the media on the receiving bottom plate31, and fixed in a predetermined fixed position. In this example, a separation plate35(refer toFIG.7) protrudes upward from the upper edge of the partitioning plate34. The separation plate35serves as a stopper wall that stops the upper area of a pile of the media located below the medium sucked by the vacuum head50with air.

<Hoist Mechanism>

As illustrated inFIG.4, the receiving bottom plate31is supported by a hoist mechanism90described below (refer toFIGS.6A and6B) to be movable upward and downward.

In this example, as illustrated inFIGS.4,6A, and6B, the hoist mechanism90includes suspension portions91disposed at four portions of the receiving bottom plate31at both sides in the width direction crossing the medium discharging direction, and four wires92to95having the far ends coupled to the respective suspension portions91. After each of the wires92to95is wound around one or more guide pulleys96, a first end of each of the wires92to95is stuck to coaxially coupled take-up pulleys97(97aand97bin this example), the take-up pulleys97are rotated by a driving motor98that is rotatable forward and backward, and the wires92to95are moved by a predetermined amount to raise or lower the receiving bottom plate31while keeping the receiving bottom plate31in a horizontal position.

A height sensor99sets the surface of one of the media loaded on the receiving bottom plate31to the predetermined medium reference height FC (refer toFIG.18A).

The medium reference height FC in this case refers to a position where the uppermost position of the medium is set for the vacuum head50to be capable of performing an air-suction operation on the media on condition that the media S with a uniform thickness such as normal paper sheets are accommodated in the container30in a substantially horizontal position.

Pay-Out Roller

In this example, as illustrated inFIG.4andFIG.7, the discharging rollers40include a driving roller41that drives to rotate, and a driven roller42that is driven to rotate following the rotation of the driving roller41. The discharging rollers40transport a medium while holding the medium at a contact portion between the driving roller41and the driven roller42.

Position Sensor

In the present exemplary embodiment, as illustrated inFIG.4, a position sensor45is disposed downstream from the discharging rollers40in the medium discharging direction. This position sensor45detects the passage of a medium through a nip area of the discharging rollers40, and is disposed in a medium passage area. A detection signal from the position sensor45notifies the end of the operation of feeding a medium S transported previously, and serves as a trigger of the operation of feeding the subsequent medium S in a successive feeding mode.

Vacuum Head

In this example, as illustrated inFIGS.4,7, and8, the vacuum head50is supported with a guide mechanism58(for example, a guide rod) by a head frame60fixed to the housing12above the container30to be movable forward and rearward in the medium discharging direction.

In this example, the vacuum head50includes a hollow box-shaped head body51. A surface of the head body51facing the media accommodated in the container30has a large number of vacuum holes52. The vacuum head50also includes a skirt portion51aaround the vacuum holes52in the head body51to keep the medium hermetic while sucking the medium with air.

A suction mechanism53is connected to the head body51. As illustrated inFIGS.10A and10B, in this case, an example used as the suction mechanism53has a structure where a suction blower54and the head body51are connected with a connection duct55, an open-close valve56that opens and shuts the path is disposed at a portion of the connection duct55, and the open-close valve56is opened or shut by a valve motor57.

A forward/rearward moving mechanism61that moves the vacuum head50forward and rearward is disposed at the head frame60. In this example, as illustrated inFIG.8andFIG.9, the forward/rearward moving mechanism61fixes a stepping motor62to the head frame60, a driving pulley63is coupled to the stepping motor62, a predetermined number of transmission pulleys64are disposed at the head frame60at appropriate positions, a wire65is wound around the driving pulley63and the transmission pulleys64, and part of the wire65is stuck to the vacuum head50. In this example, the driving pulley63rotates in response to the forward or rearward rotation of the stepping motor62, the wire65moves by a predetermined distance in response, and the vacuum head50moves forward or rearward in the medium discharging direction.

Floating Mechanism

In this example, as illustrated inFIGS.4,5,7, and11, the floating mechanism70includes, for example, hollow box-shaped side guides32(32aand32b). Each side guide32has multiple air outlets71at an upper portion facing the side of the media, and has, in the hollow portion, an air duct72having one end continuous with the corresponding air outlet71and the other end continuous with a blower73for blowing air. In this case, the blower73may be installed inside each side guide32or disposed outside of the side guide32.

In this example, medium restrictors100are disposed near the air outlets71of the side guide32. The medium restrictors100in this example are disposed on the side of the media loaded on the receiving bottom plate31, and protrude to a medium accommodation area to restrict floating excess of media that float while using the floating mechanism70.

In this example, a shutter mechanism75that opens or shuts each of the air outlets71is disposed. As illustrated inFIGS.11,12A, and12B, the shutter mechanism75includes a planar shutter76covering the air outlet71and a shutter driving mechanism77that vertically moves the shutter76in a reciprocating manner. An example used as the shutter driving mechanism77in this case includes a driving motor771formed from a stepping motor, a driving transmission gear772coaxial with a driving shaft of the driving motor771, a shutter support member773that supports a lower portion of the shutter76, a rack774vertically extending at a side edge of the shutter support member773, and a driving transmission gear train775disposed between the rack774and the driving transmission gear772to engage the rack774and the driving transmission gear772with each other to transmit the driving force between the rack774and the driving transmission gear772via the driving transmission gear train775. Thus, the driving force from the driving motor771driven based on the driving signal from a control device200is transmitted to the shutter76.

Thus, in this example, each air outlet71is repeatedly opened and shut by the shutter mechanism75. Thus, air blown from the air outlets71is capable of easily floating the upper portion of the medium S in a fluctuation pattern.

Air Handling Mechanism

In this example, as illustrated inFIGS.4,7, and13A to13C, the air handling mechanism80includes an air nozzle81that blows knife-shaped air to obliquely rearward from below to the end of the medium floated by the floating mechanism70in the discharging direction. An air guide plate82protrudes from a portion of the vacuum head50closer to the discharging rollers40to change the direction of air blown from the air nozzle81, and to separate the media by blowing air between the upper medium floated by the floating mechanism70and the media located below the upper medium.

In this example, the air nozzle81is continuous with an air duct83, to which an air blowing blower84is connected. Thus, at a portion of the air duct83, an open-close valve85that opens or shuts the flow path is disposed. The open-close valve85is opened or shut by a valve motor86. Thus, in this example, while the blower84is kept driving, air blown from the air nozzle81is switched by opening or shutting the open-close valve85.

Auxiliary Suction Device

Particularly, the present exemplary embodiment includes an auxiliary suction device120that assists the vacuum head50in performing the medium air-suction operation.

<Layout of Auxiliary Suction Device>

In this example, as illustrated inFIGS.4,7, and8, the auxiliary suction device120is disposed close to the vacuum head50on a side opposite to the side closer to the discharging member in the discharging direction in which the media S are discharged. In this example, the auxiliary suction device120is attached, with a holder bracket121, to an outer surface of a side wall of the head frame60that supports the vacuum head50facing in a direction opposite to the discharging direction in which the media S are discharged.

In this example, the auxiliary suction device120is held by the head frame60while being not in contact with the vacuum head50, but may be held by the head frame60while being in contact with the vacuum head50. Specifically, in this example, the auxiliary suction device120may be located closer to the vacuum head50on the side opposite to the side closer to the discharging member in the discharging direction in which the media S are discharged regardless of whether the auxiliary suction device120is in contact with or not in contact with the vacuum head50.

“Being located closer to the vacuum head50” will be more specifically described now. In this example, for example, in relation to the positional relationship between an initial position of the end guide33when the media S with a size maximum receivable by the container30is accommodated and a side wall portion of the vacuum head50located on the side opposite to the side closer to the discharging member in the discharging direction in which the media S are discharged, when the auxiliary suction device120is located closer to the side wall portion of the vacuum head50than to the end guide33, the auxiliary suction device120is regarded as “being located closer to the vacuum head50”.

More specifically, for example, when media such as envelopes with an uneven thickness are accommodated in the container30, as illustrated inFIG.15A, the media S may be inclined inside the container30. In this state, a portion of the uppermost medium S1of the media S facing the vacuum head50may be located lower than the medium reference height FC, and thus the inclined medium S1is more likely to fail to be sucked with air only by the vacuum head50. To address such a technical problem, an appropriate layout of the auxiliary suction device120is found with reference to a medium with the maximum usable size because the auxiliary suction device120located away from the vacuum head50fails to assist the vacuum head50in air suction of media regardless of when being located on the side of the vacuum head50opposite to the side closer to the discharging member in the discharging direction in which the media are discharged.

Particularly, such a technical problem frequently occurs in handling frequently used envelopes of the sizes “K2”, “K3”, “N3”, and “N4” in JIS. Thus, when such envelopes are used, the auxiliary suction device120is preferably located closer to the vacuum head50than to the position of the end guide33(the trailing end positions of these envelopes opposite to the leading end portions in the discharging direction in which the envelopes are transported).

Among these envelopes, N4 (width 90×length 205 mm) is the smallest size. In view of this size, the auxiliary suction device120is preferably located within 102.5 mm from the leading end of the envelope.

<Structure Example of Auxiliary Suction Device>

In this example, as illustrated inFIGS.7and14A to14C, the auxiliary suction device120includes a moving duct122that is expandable under its own weight.

In this example, as illustrated inFIG.14A, the moving duct122includes substantially cylindrical divided ducts131and132, obtained by being divided into multiple (two in this example) pieces. The first divided duct131is slidably fitted onto the second divided duct132under its own weight. The first divided duct131has an inner flange133at the lower-end inner edge, the second divided duct132has an outer flange134at the upper-end outer edge, and the outer flange134of the second divided duct132is undetachably hooked on the inner flange133of the first divided duct131. The outer flange134of the second divided duct132and the inner peripheral surface of the first divided duct131are hermetically sealed with an annular sealant135. In addition, a stopper piece136that protrudes radially is installed at the lower-end outer edge of the second divided duct132after the second divided duct132is fitted into the first divided duct131. The stopper piece136prevents the second divided duct132from being entirely drawn into the first divided duct131.

In this example, as illustrated inFIG.14A, when the first divided duct131in the moving duct122in the auxiliary suction device120is held by the holder bracket121(refer toFIG.7), the second divided duct132fitted into the first divided duct131falls downward under its own weight, and the moving duct122extends to arrive at the uppermost medium S1of the media S in the container30. At this time, the second divided duct132is extendable downward until the outer flange134abuts against the inner flange133of the first divided duct131at the maximum, but the second divided duct132stops when abutting against the uppermost medium S1of the media S in the container30.

In this case, as illustrated inFIG.15A, a lower end position FC1to which the moving duct122is extended at the maximum under its own weight is set lower than the medium reference height FC, and appropriately selected within a range within which the moving duct122is capable of coming into contact with the uppermost medium S1of the media S such as envelopes loaded in the container30while being inclined.

In this state, when the auxiliary suction device120is sucked by a suction mechanism described later, as illustrated inFIG.14B, the far end of the moving duct122sucks the medium S1with air, and is thus shut by the medium S1. Thus, the second divided duct132is drawn into the first divided duct131with the air suction force, and the moving duct122is switched from an extended state to a contracted state.

<Another Structure Example of Auxiliary Suction Device>

In this example, the auxiliary suction device120includes the moving duct122including multiple expandable divided ducts131and132, but this is not an only possible example. For example, as illustrated inFIG.14C, an elastically deformable bellows142may be disposed at a portion of a resin-made duct body141to allow the duct body141to extend under its own weight using this elastic deformation of the bellows142.

<Suction Mechanism of Auxiliary Suction Device>

In this example, the moving duct122in the auxiliary suction device120has its upper end portion connected to the suction mechanism. In this case, a suction mechanism dedicated for the auxiliary suction device120may be used, but in this example, as illustrated inFIG.15A, the suction mechanism53in the vacuum head50is used also as the suction mechanism for the auxiliary suction device120.

In this example, the suction mechanism53for the auxiliary suction device120includes a diverging connection duct150. The diverging connection duct150diverges from a connection duct55that connects the suction blower54and the vacuum head50, connects the diverging connection duct150and the upper end portion of the moving duct122in the auxiliary suction device120, and opens or shuts, with a valve motor152, an open-close valve151disposed at a portion of the diverging connection duct150to open or shut the flow path.

<Air Suction Operation of Auxiliary Suction Device and Vacuum Head>

In this example, as illustrated inFIG.15B, the auxiliary suction device120opens the open-close valve151at a timing to earlier than the vacuum head50to start the air suction operation. Thereafter, the vacuum head50opens the open-close valve56at a timing t1a predetermined time after the timing t0to start the air suction operation. Thereafter, the auxiliary suction device120shuts the open-close valve151at a timing t2a predetermined time after the timing t1to finish the air suction operation.

Control System

As illustrated inFIG.4, the present example includes the control device200that controls the medium feeding device11. The control device200is formed from a microcomputer including various processors. In the embodiments above, the term “processor” refers to a processor in a broad sense. Examples of the processor include general processors (for example, a central processing unit or CPU) and dedicated processors (for example, a graphics processing unit or GPU, an application specific integrated circuit or ASIC, a field programmable gate array or FPGA, and a programmable logic device).

This control device200captures, into the processors, various information resulting from, for example, job identification, or signals from various sensors (such as the position sensor45and the height sensor99), executes various programs preinstalled into a memory not illustrated, and transmits a predetermined control signal to each control target.

In this example, examples of the control target include the discharging rollers40, the vacuum head50(the suction mechanism53, and the forward/rearward moving mechanism61), the floating mechanism70, the air handling mechanism80, the hoist mechanism90, and the auxiliary suction device120. The control device200includes a display210that displays the processing state of the medium feeding job or a warning indicating an abnormal state in medium feeding.

Medium Feeding Operation Process

First, a basic medium feeding operation process of a medium feeding device according to an exemplary embodiment will be described with reference toFIGS.16A to16E.

First, as illustrated inFIG.16A, the floating mechanism70blows floating air from a side of a medium pile to float some upper sheets in the medium pile to the positions to be sucked by the vacuum head50with air.

In this state, as illustrated inFIG.16B, the auxiliary suction device120opens the open-close valve56in the suction mechanism53in the vacuum head50to cause the vacuum head50to form a negative pressure. Thus, the vacuum head50sucks the floating medium S1located uppermost with air. At this time, the vacuum head50has a recessed portion between the surrounding skirt portion51aand the surfaces of the vacuum holes52in the head body51. Thus, the medium S1is deformed along the recessed portion, and the skirt portion51adisposed to tightly close the negative pressure area is also raised together with the medium S1.

Particularly, in the present example, the auxiliary suction device120performing air suction of media assists the vacuum head50in air suction of the media S. This will be described in detail later.

Thereafter, as illustrated inFIG.16C, the open-close valve85in the air handling mechanism80is opened, air is applied to the air guide plate82located on the side of the vacuum head50facing in the discharging direction, to insert separating air between the uppermost medium S1sucked by the vacuum head50with air and the second and lower media S located below the uppermost medium S1, and the second and lower media S following the uppermost medium S are dropped down with air.

Thereafter, as illustrated inFIG.16D, the vacuum head50holding the uppermost medium S1moves forward toward the discharging rollers40, the vacuum head50passes the medium S1to the discharging rollers40, and then the open-close valve56in the vacuum head50and the open-close valve85in the air handling mechanism80are shut.

Thereafter, as illustrated inFIG.16E, the vacuum head50is returned to the initial position to be ready for the next medium feeding operation.

<Timing Chart of Each Device>

FIG.17is a timing chart of each device in the above medium feeding operation process.

InFIG.17, “a vacuum-head blower” corresponds to “the blower54” (refer toFIGS.10A and10B) in the suction mechanism53, “an air-handling blower” corresponds to “the blower84” (refer toFIGS.13A to13C) in the air handling mechanism80, and “a flotation blower” corresponds to “the blower73” (refer toFIG.11) in the floating mechanism70.

“A vacuum-valve motor” corresponds to the valve motor57, “an air-handling valve motor” corresponds to the valve motor86, and “a vacuum-head motor” corresponds to the stepping motor62in the forward/rearward moving mechanism61.

In this example, “the vacuum-head blower”, “the air-handling blower”, and “the flotation blower” are kept on during the medium feeding job. “The vacuum-valve motor”, “the air-handling valve motor”, and “the vacuum-head motor” repeat on/off control for each sheet medium to repeatedly perform suction and forward/rearward movement with the vacuum head50and feeding and stopping feeding of separation air from the air handling mechanism80.

Operation of Auxiliary Suction Device

In this example, the auxiliary suction device120has the following three structural features.

The first feature is that the auxiliary suction device120is located closer to the vacuum head50on the side opposite to the side closer to the discharging member in the discharging direction in which the media are discharged.

The second feature is that the auxiliary suction device120sucks the media S with air earlier than the vacuum head50does.

The third feature is that the auxiliary suction device120sucks the media S with air at a position lower than the medium reference height FC.

Thus, the auxiliary suction device120according to the present exemplary embodiment has the following operations.

In this example, as illustrated inFIG.15A, before starting the air suction operation, the auxiliary suction device120has the moving duct122extending downward under its own weight.

Particularly, in this example, as illustrated inFIG.19A, the lower end portion of the moving duct122in the auxiliary suction device120is set at the position FC1lower than the medium reference height FC. Thus, regardless of when the media S accommodated in the container30are media with an uneven thickness such as envelopes, and are inclined with respect to the container30while having the end of the media S in the discharging direction in which the media S are discharged lowered, the lower end opening of the auxiliary suction device120is located in contact with or adjacent to the surface of the uppermost medium S1in the pile of the media S.

In this state, when upper sheets in the media S are floated by the floating mechanism70, the lower end opening of the auxiliary suction device120comes into contact with the floating uppermost medium S1.

In this example, as illustrated inFIG.18A, in order to start the air suction operation earlier than the vacuum head50, the auxiliary suction device120sucks the medium S1with air at the lower end opening, and transports the medium S1to an upper position while sucking the medium S1with air and contracting the second divided duct132in the moving duct122.

In this state, as illustrated inFIG.19B, the medium S1sucked and held by the auxiliary suction device120is raised upward by the medium reference height FC to approach the suction surface of the vacuum head50.

Thereafter, as illustrated inFIG.18B, when the vacuum head50starts the air suction operation, the medium S1is sucked by the vacuum head50with air, and the air-suction operation of the medium S1is handed over from the auxiliary suction device120to the vacuum head50.

During this period, as illustrated inFIG.15B, the auxiliary suction device120and the vacuum head50concurrently keep performing the air suction operation for a predetermined time period, and thus the air-suction operation of the media S is stably handed over to the vacuum head50.

Thereafter, when the auxiliary suction device120finishes the air suction operation, the vacuum head50moves toward the discharging rollers40while sucking the media S with air, and passes the medium S1to the discharging rollers40. During this period, the auxiliary suction device120finishes the air-suction operation of the medium S1. Thus, the operation of transporting the media S performed by the vacuum head50is not interrupted by the auxiliary suction device120.

In this example, as illustrated inFIG.19C, the auxiliary suction device120is installed at substantially the center of the head frame60in the width direction, while being extended to the position FC1lower than the medium reference height FC. Thus, regardless of when the media S accommodated in the container30are deformed in a recessed shape in a width direction or a front-rear direction crossing the discharging direction in which the media S are discharged or when media S′ are accommodated while being inclined in the width direction, the auxiliary suction device120in this example is securely capable of sucking uppermost medium S1or S1′ with air.

First Comparative Example

To evaluate the performance of the medium feeding device11according to the present exemplary embodiment, a medium feeding device according to a first comparative example will be described.

As illustrated inFIG.20A, a medium feeding device11′ according to the first comparative example includes a container300that accommodates a pile of the media S, discharging rollers301that discharge the media S one by one, a vacuum belt302disposed above the container300and at a position closer to the discharging rollers301to suck and transport the leading end of the media S in the discharging direction, a trailing-end sucking portion303disposed above the container300and at a trailing end portion on a side away from the discharging roller301to suck the trailing end of the media S in the discharging direction, and an air blower (not illustrated) that blows air to the media S from the side of the container300to float the upper portion of the media S.

Particularly, in this example, the trailing-end sucking portion303includes a moving portion that is movable vertically or perpendicular to the uppermost surface of the media S accommodated in the container300, and a blower that causes a suction force with which the uppermost medium S1is sucked by the moving portion. While not sucking the media S, the moving portion moves downward to come into contact with the uppermost medium S1, and when sucking the medium S1, the moving portion moves upward to separate the trailing end of the medium S1from other media S.

In addition, the trailing-end sucking portion303is fixed to an upper portion of a trailing-end restricting member that restricts the trailing end position of the media S accommodated in the container300, and located corresponding to the trailing end position of the media S.

InFIG.20A, a lower-end movable position P of the trailing-end sucking portion303corresponds to the position of a predetermined medium S located uppermost in the container300.

In this example, as illustrated inFIG.20C, the vacuum belt302and the trailing-end sucking portion303concurrently start the air-suction operation.

In this example, as illustrated inFIG.20B, the vacuum belt302sucks with air the leading end portion of the uppermost medium S1among the media S floated with air blown from an air blower not illustrated, and the trailing-end sucking portion303is lowered to a predetermined lower-end movable position P to suck the trailing end portion of the uppermost medium S1with air, and then moves to an upper position. In this state, the vacuum belt302and the trailing-end sucking portion303suck and hold the uppermost medium S1, and then transport the medium S1sucked and held by the vacuum belt302toward the discharging roller301.

In this case, when the medium S1is transported toward the discharging roller301, the medium S1deviates from the surface of the trailing-end sucking portion303for sucking the medium S1, and thus, the trailing-end sucking portion303moves downward to come into contact with the next uppermost media S.

In this example, the vacuum belt302and the trailing-end sucking portion303thus suck and hold the leading end portion and the trailing end portion of the medium S1in the discharging direction, and pass the medium S1to the discharging roller301. Thus, to feed a medium S that is long in the discharging direction, regardless of when the separating air from the air blower fails to arrive at the trailing end of the medium S1, the long medium S1is allowed to be sucked and held, and passed to the discharging roller301.

Specifically, in the present example, as long as the media S are accommodated in the container300while remaining in a substantially horizontal position, the vacuum belt302and the trailing-end sucking portion303are capable of sucking and holding the medium S1, and effectively perform the medium feeding operation. However, as in the present exemplary embodiment, when media S with uneven thickness such as envelopes are accommodated, the media S may be inclined, and the uppermost medium S1may be located lower than the predetermined lower-end movable position P. Thus, the vacuum belt302or the trailing-end sucking portion303may fail to suck the medium S1with air.

This example is not designed assuming such a case of the media S disposed in an inclined position, and thus is unable to address medium feeding failures caused by such inclination.

In the present exemplary embodiment, the auxiliary suction device120includes an expandable moving duct122that extends downward under its own weight, but the structure example (FIGS.14A to14C) according to the first exemplary embodiment is not the only possible structure. For example, a modification example 1-1 or a modification example 1-2 may be employed instead.

Modification Example 1-1

FIG.21Aillustrates an auxiliary suction device120according to a first modification example.

InFIG.21A, the auxiliary suction device120includes an expandable moving duct122. For example, as illustrated inFIG.20B, multiple (three in this example), substantially cylindrical large, middle, and small divided ducts161to163are expansively and undetachably fitted to each other to extend the duct length under their own weight.

In this example, the large-diameter divided duct161in the moving duct122is held by a portion of the head frame60with a holder bracket164. A protruding piece165that radially protrudes is installed at a lower end portion of the circumferential surface of the small-diameter divided duct163in the moving duct122. The protruding piece165is stopped by a stopper mechanism166at a predetermined position to keep the moving duct122in a contracted initial state. A stopper piece162aradially protrudes from the lower-end outer edge of the middle-diameter divided duct162to restrict the contracting operation of the middle-diameter divided duct162when the moving duct122is contracted.

The reason why the stopper mechanism166is installed is to hold the auxiliary suction device120in an unused state to prevent the auxiliary suction device120from interfering with other components when the media S accommodated in the container30are small and when the media S are not located at the portion facing the auxiliary suction device120.

In the stopper mechanism166in this example, a stopper piece169radially protrudes at the lower end of a rotation shaft168rotatably held by a bearing holder167. A transmission gear170is disposed on the rotation shaft168to be coaxial with the rotation shaft168. A driving transmission belt172is wound around the transmission gear170and a driving gear171coupled to a driving motor shaft not illustrated. The rotation shaft168swings within, for example, a predetermined angle range. The stopper mechanism166swings the stopper piece169between a stop position where the protruding piece165is stopped and a stop release position where the protruding piece165is not stopped.

As illustrated inFIG.21C, when the auxiliary suction device120is unused, the stopper mechanism166stops the protruding piece165at the stop position to hold the moving duct122in the contracted initial state. When the auxiliary suction device120is used, the stopper mechanism166is detached from the protruding piece165to allow the moving duct122to extend downward under its own weight.

Modification Example 1-2

FIG.22Aillustrates an auxiliary suction device120according to a modification example 1-2.

InFIG.22A, similarly to the first exemplary embodiment, the auxiliary suction device120includes a moving duct. However, unlike the first exemplary embodiment and the modification example 1-1, the auxiliary suction device120includes a moving duct180vertically moved by a driving mechanism190instead of being expandable under its own weight.

In this example, the moving duct180includes a second duct element182coupled, with a middle duct element183interposed therebetween, to a first duct element181connected to the diverging connection duct150. In this case, the first duct element181is held while being vertically movable along a guide rail185. An elastic spring184is interposed between the first duct element181and the second duct element182. The first duct element181and the middle duct element183are relatively movably coupled together. The second duct element182and the middle duct element183are immovably coupled together.

The driving mechanism190includes a worm gear191extending along the guide rail185. The worm gear191is engaged with a driving gear193coaxially fixed with the driving shaft of a driving motor192to vertically move the first duct element181with rotation of the worm gear191.

In this example, as illustrated inFIG.22A, the auxiliary suction device120when unused may keep the moving duct180at an upper position away from the media S. As illustrated inFIG.22B, the auxiliary suction device120when used may move downward to bring the lower end opening of the moving duct180into contact with the uppermost medium S1, and then move to the upper position while starting the air suction operation.

In this example, in the moving duct180, the elastic spring184allows the first duct element181and the second duct element182to be elastically deformed. Thus, as illustrated inFIG.22B, regardless of when the far end portion of the second duct element182forcibly comes into contact with the medium S1, the excess force is absorbed by the elastic spring184.

Second Exemplary Embodiment

FIG.23Aillustrates a related portion of a medium feeding device according to a second exemplary embodiment.

InFIG.23A, the medium feeding device11has substantially the same structure as the first exemplary embodiment, and includes a container30, discharging rollers40, a vacuum head50, a floating mechanism not illustrated, and an auxiliary suction device120. The auxiliary suction device120is vertically movable. The auxiliary suction device120sucks the media S with air at a position FC1lower than the medium reference height FC, and moves to the upper position as illustrated inFIG.23B.

However, as illustrated inFIG.23C, unlike the first exemplary embodiment, the auxiliary suction device120according to the present exemplary embodiment starts the air suction operation concurrently (at a timing t0) with the vacuum head50, and finishes the air-suction operation at a timing t1a predetermined time after the start. The vacuum head50keeps the air suction operation also after the auxiliary suction device120finishes the air suction operation, moves toward the discharging rollers40while sucking and holding the medium S1, and passes the medium S1to the discharging rollers40.

In this example, the auxiliary suction device120starts the air suction operation concurrently with the vacuum head50. After sucking the uppermost medium S1with air while being located closer to the uppermost medium S1than the vacuum head50, the auxiliary suction device120raises the medium S1to the upper position. Thus, after the vacuum head50starts the air suction operation and the medium S1approaches the suction surface of the vacuum head50, the vacuum head50sucks the medium S1with air.

Third Exemplary Embodiment

FIG.24Aillustrates a related portion of a medium feeding device according to a third exemplary embodiment.

InFIG.24A, the basic structure of the medium feeding device11is substantially the same as that of the first exemplary embodiment. The medium feeding device11performs the air suction operation with the suction mechanism53used in common by the vacuum head50and the auxiliary suction device120, but differs from that according to the first exemplary embodiment in the structures of the open-close valves56and151.

In this example, as illustrated inFIGS.24A and24B, shutter valves221and222having the opening degree adjustable are used as open-close valves for the vacuum head50and the auxiliary suction device120. The shutter valves221and222have a structure corresponding to the structure of a camera shutter, and form a flow path opening223with a shutter member224into a completely-shut state, a fully-open state, and a semi-open state in which the flow path is half shut and half open.

In this example, as illustrated inFIG.24B, the auxiliary suction device120performs preliminary suction earlier than the vacuum head50while the shutter valve222is in the fully-open state, and then, when shifting from the preliminary suction to the operation of the vacuum head50, performs air suction while the shutter valve222is in the semi-open state. Thereafter, the auxiliary suction device120finishes the air suction operation while the shutter valve222is in the completely-shut state.

On the other hand, as illustrated inFIG.24B, when the auxiliary suction device120performs preliminary suction, the vacuum head50does not start the air suction operation while the shutter valve221is in the completely-shut state. Thereafter, when the preliminary suction performed by the auxiliary suction device120is to be shifted to the operation of the vacuum head50, the vacuum head50starts air suction while the shutter valve221is in the semi-open state, and then keeps the air suction operation while the shutter valve221is in the fully-open state.

Thus, in this example, when the preliminary suction performed by the auxiliary suction device120is shifted to the operation performed by the vacuum head50, the air suction is performed in the semi-open state in which the flow path is half shut and half open. After the air suction operation is handed over from the auxiliary suction device120to the vacuum head50, the preliminary suction is finished, and the vacuum head50performs air suction while the shutter valve221is in the fully-open state. Thus, the suction force in the air suction is not reduced.

In the present exemplary embodiment, the shutter valves221and222are respectively used for the vacuum head50and the auxiliary suction device120, but they are not the only possible examples. For example, as illustrated in modification examples 3-1 to 3-3, air suction of the vacuum head50and the auxiliary suction device120may be controlled by a single common valve230(refer toFIGS.25A to27B).

Modification Example 3-1

FIG.25Ais a related portion of a medium feeding device according to the modification example 3-1.

InFIG.25A, the basic structure of the medium feeding device11is substantially the same as that of the third exemplary embodiment, but differs from that of the third exemplary embodiment in that the common valve230is disposed at a diverging portion between the connection duct55and the diverging connection duct150.

In this example, the diverging connection duct150diverges from the connection duct55to form a T-shaped space231having substantially a letter T shape. The common valve230swingably supports an elliptical valve plate232at a junction in the T-shaped space231around a swing support233.

In this case, as illustrated inFIG.25B, when the auxiliary suction device120performs preliminary suction, the common valve230shuts, with the valve plate232, the flow path of the connection duct55continuous with the vacuum head50. When the vacuum head50performs suction, the common valve230shuts, with the valve plate232, the flow path of the diverging connection duct150. When the preliminary suction is shifted to the operation of the vacuum head50, the common valve230places the valve plate232at a neutral position to allow the auxiliary suction device120and the vacuum head50to concurrently perform suction to prevent reduction of the total suction force during the concurrent suction.

Modification Example 3-2

FIG.26Aillustrates a related portion of a medium feeding device according to a modification example 3-2.

InFIG.26A, the basic structure of the medium feeding device11is substantially the same as that of the modification example 3-1, and includes a T-shaped space231and a common valve230, but differs from the modification example 3-1 in the structure of the common valve230.

In this example, the common valve230includes a spherical valve sphere240slidably disposed in a horizontal space231aincluding the junction in the T-shaped space231.

In this case, as illustrated inFIG.26B, the common valve230shuts, with the valve sphere240, the flow path of the connection duct55continuous with the vacuum head50when the auxiliary suction device120performs preliminary suction. When the vacuum head50performs suction, the valve sphere240shuts the flow path of the diverging connection duct150. In addition, when the preliminary suction is shifted to the operation of the vacuum head50, the common valve230places the valve sphere240in the neutral position to allow the auxiliary suction device120and the vacuum head50to concurrently perform suction, and prevent reduction of the total suction force at the concurrent suction.

Modification Example 3-3

FIG.27Aillustrates a related portion of a medium feeding device according to a modification example 3-3.

InFIG.27A, the basic structure of the medium feeding device11is substantially the same as those of the modification examples 3-1 and 3-2, and includes a T-shaped space231and a common valve230, but differs from those of the modification examples 3-1 and 3-2 in the structure of the common valve230.

In this example, the common valve230includes a spherical valve body250rotatably disposed at the junction of the T-shaped space231, and the valve body250has a T-shaped air flow path251.

As illustrated inFIG.27B, the common valve230shuts, with the valve body250, the connection duct55continuous with the vacuum head50when the auxiliary suction device120performs preliminary suction, and rotates the valve body250to a first rotation position A1to connect the air flow path251to the diverging connection duct150and a vertical space231bincluding a junction in the T-shaped space231. When the vacuum head50performs suction, the common valve230shuts the diverging connection duct150with the valve body250, and rotates the valve body250to the second rotation position A2to connect the air flow path251to the connection duct55continuous with the vacuum head50and the vertical space231bincluding the junction of the T-shaped space231.

In addition, when the preliminary suction is shifted to the operation performed by the vacuum head50, the common valve230rotates the valve body250to a third rotation position A3, to locate the air flow path251to connect the T-shaped space231to the diverging connection duct150and the connection duct55. In this case, the auxiliary suction device120and the vacuum head50are concurrently allowed to perform suction, and the total suction force at the concurrent suction is retained without being reduced.

Fourth Exemplary Embodiment

FIG.28Ais a rough diagram of a medium feeding device according to a fourth exemplary embodiment.

InFIG.28A, the basic structure of the medium feeding device11is substantially the same as those of the modification examples 3-1 to 3-3 obtained by modifying the third exemplary embodiment, and controls the air suction operation performed by the vacuum head50and the auxiliary suction device120with the common valve230, but differs from the modification examples 3-1 to 3-3 obtained by modifying the third exemplary embodiment in the air suction operation performed by the auxiliary suction device120. The auxiliary suction device120and other components are the same as those of the first exemplary embodiment.

Specifically, in this example, the common valve230includes a valve switch310that selectively switches between a flow path of the connection duct55located closer to the vacuum head50than a diverging portion between the connection duct55and the diverging connection duct150, and a flow path of the diverging connection duct150.

As illustrated inFIG.28B, the auxiliary suction device120starts the air suction operation at a timing to earlier than the vacuum head50. Thereafter, when the vacuum head50starts the air suction operation at a timing t1, the auxiliary suction device120concurrently finishes the air suction operation.

In the present exemplary embodiment, as illustrated inFIG.29A, when the auxiliary suction device120performs preliminary suction, the auxiliary suction device120extends to a lower position to the position FC1lower than the medium reference height FC under its own weight, and comes into contact with the uppermost medium S1. Then, the auxiliary suction device120sucks and holds the medium S1to raise the medium S1to the upper position.

In this state, the medium S1sucked and held by the auxiliary suction device120is located at a position close to the suction surface of the vacuum head50.

Thereafter, as illustrated inFIG.29B, with a switching operation of the valve switch310in the common valve230, the vacuum head50starts the air suction operation, and concurrently, the auxiliary suction device120finishes the air suction operation.

When the auxiliary suction device120finishes the air suction operation, the auxiliary suction device120stops exerting the air suction force on the medium S1, but the vacuum head50immediately starts the air suction operation, and starts exerting the air suction force on the medium S1. Thus, the medium S1sucked and held by the auxiliary suction device120is switched to be immediately sucked and held by the vacuum head50. Thus, as in the present example, regardless of when the air suction operation is selectively switched from the auxiliary suction device120to the vacuum head50, the auxiliary suction device120assists the vacuum head50in air-suction operation of the medium S1.

Fifth Exemplary Embodiment

FIG.30illustrates a related portion of a medium feeding device according to a fifth exemplary embodiment.

InFIG.30, the basic structure of the medium feeding device11is substantially the same as those of the first to fourth exemplary embodiments, but differs from those of the first to fourth exemplary embodiments in that the auxiliary suction device120is disposed at a portion of the head body51in the vacuum head50to move forward and rearward together with the vacuum head50.

In this example, the basic structure of the auxiliary suction device120is substantially the same as, for example, that of the first exemplary embodiment, but differs from that of the first exemplary embodiment in the air suction operation performed by the auxiliary suction device120.

Specifically, in this example, as illustrated inFIG.31C, the auxiliary suction device120starts the air suction operation at the timing to earlier than the vacuum head50, continues performing the air suction operation also after the vacuum head50starts the air suction operation at the timing t1, and finishes the air suction operation at the timing t2when the vacuum head50finishes the air suction operation.

As illustrated inFIG.31C, according to the present exemplary embodiment, when the auxiliary suction device120performs preliminary suction, as illustrated inFIG.31A, the auxiliary suction device120extends downward under its own weight toward the position FC1lower than the medium reference height FC, and comes into contact with the uppermost medium S1. The auxiliary suction device120then sucks and holds the medium S1, and raises the medium S1to the upper position.

In this state, the medium S1sucked and held by the auxiliary suction device120is located close to the suction surface of the vacuum head50.

Thereafter, as illustrated inFIG.31C, when the vacuum head50starts the air suction operation, as illustrated inFIG.31B, the medium S1sucked and held by the auxiliary suction device120is sucked by the vacuum head50with air. Thus, the medium S1sucked with air by both the vacuum head50and the auxiliary suction device120is handed over to the discharging rollers40with the movement of the vacuum head50toward the discharging rollers40.

In this case, when the medium S1is handed over to the discharging rollers40, the vacuum head50and the auxiliary suction device120finish the air suction operation, and return to the initial positions.

The foregoing description of the exemplary embodiments of the present disclosure has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, thereby enabling others skilled in the art to understand the disclosure for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the disclosure be defined by the following claims and their equivalents.