BACKGROUND
Technical Field
[0001] The present invention relates to a conveyed-material separation device and a conveyed-material
conveyance apparatus including the conveyed-material separation device.
Related Art
[0002] Devices and methods for separating and conveying prepregs are known (for example,
see
JP-2003-311769-A). In
JP-2003-311769-A, a device and a method for supplying prepreg are disclosed.
JP-2003-311769-A describes that an attraction pad rotated by a cylinder or the like is used to attract
and raise (upward rotation) an attracting portion or an end portion of the first prepreg
of stacked prepregs, and another attraction pad moved up and down by another cylinder
is used to attract and raise an end portion of the second prepreg. Then, both of the
attraction pads are simultaneously moved horizontally, for example, about 50 mm to
separate and convey two prepregs needed.
[0003] However, the technique described in
JP-2003-311769-A has a problem that separation of prepregs are not easily performed in accordance
with the width dimension of the prepregs.
[0004] In light of the above-described circumstance, a purpose of the present invention
is to provide a conveyed-material separation device to easily separate conveyed materials,
such as circuit board sheets or prepregs, in accordance with the width dimension of
the conveyed materials.
SUMMARY
[0005] In an aspect of this disclosure, there is provided a conveyed-material separation
device that includes an air jetting unit and a retaining unit. The air jetting unit
jets air to stacked conveyed materials to float an end of a conveyed material. The
retaining unit retains and separates the conveyed material floated by the air jetting
unit. A position of the retaining unit is changeable according to a width dimension
of the conveyed material in a width direction perpendicular to a floating direction
of the conveyed material.
[0006] In another aspect of this disclosure, there is provided a conveyed-material separation
device that includes an air jetting unit and a plurality of retaining units. The air
jetting unit jets air to stacked conveyed materials to float an end of a conveyed
material. The plurality of retaining units retains and separates the conveyed material
floated by the air jetting unit. The plurality of retaining units is disposed at positions
capable of retaining a conveyed material having a maximum size usable in the conveyed-material
separation device. The plurality of retaining units is selectively driven and used
according to a size of the conveyed material to be used.
[0007] In another aspect of this disclosure, there is provided a conveyed-material separation
device that includes the conveyed-material separation device and a conveyor to convey
the conveyed material retained by conveyed-material separation device.
[0008] According to the present invention, a conveyed-material separation device can be
provided that easily separates conveyed materials, such as circuit board sheets or
prepregs, in accordance with the width dimension of the conveyed materials.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0009] The aforementioned and other aspects, features, and advantages of the present disclosure
would be better understood by reference to the following detailed description when
considered in connection with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a conveyed-material conveyance apparatus including
a conveyed-material separation device according to an embodiment of the present invention;
FIG. 2 is a perspective view of an outer appearance of the conveyed-material conveyance
apparatus of FIG. 1;
FIG. 3 is a schematic view of a separation state of conveyed materials in the conveyed-material
conveyance apparatus of FIG. 1;
FIG. 4 is a plan view of the conveyed-material conveyance apparatus of FIG. 2;
FIG. 5 is a flowchart of steps executed by the conveyed-material conveyance apparatus
of FIG. 1;
FIGS. 6A, 6B, and 6C are illustrations of operational transition states of the conveyed-material
conveyance apparatus of FIG. 1;
FIGS. 7A and 7B are illustrations of operational transition states of the conveyed-material
conveyance apparatus following the state of FIG. 6C;
FIG. 8A is a perspective view of a conveyed-material conveyance apparatus including
a conveyed-material separation device according to Embodiment 1 of the present invention;
FIGS. 8B to 8G are plan views of examples of arrangements of units shown in table
1 according to Embodiment 1 of the present invention;
FIG. 9 is a cross-sectional side view of a portion of a retaining conveyance unit
according to Embodiment 1;
FIG. 10 is a perspective view of the retaining conveyance unit of Embodiment 1, seen
diagonally from an upper right side thereof;
FIG. 11 is a perspective view of the retaining conveyance unit of Embodiment 1 with
a flow of suction air;
FIG. 12 is a partial perspective view of belt retaining areas of a plurality of conveyor
belts of the retaining conveyance unit according to Embodiment 1;
FIG. 13 is a back view of an arrangement of return nozzle units according to Embodiment
1;
FIG. 14 is a flowchart of steps executed by the conveyed-material conveyance apparatus
of Embodiment 1;
FIG. 15 is a front view of the conveyed-material separation device according to Embodiment
1 in a state in which conveyed materials are isolated and separated with the conveyed-material
separation device and attracted and retained by one of a plurality of retaining conveyance
units;
FIGS. 16A and 16B are illustrations of action of return air in Embodiment 1;
FIGS. 17 is a front view of a conveyed-material conveyance apparatus including a conveyed-material
separation device according to another embodiment of the present invention;
FIG. 18 is a plan view of the conveyed-material conveyance apparatus of FIG. 17;
FIGS. 19A to 19C are schematic views of operational transition states of the conveyed-material
conveyance apparatus of FIG. 17; and
FIGS. 20A to 20C are schematic views of operational transition states of the conveyed-material
conveyance apparatus, following the transition state of FIG. 19C.
[0010] The accompanying drawings are intended to depict embodiments of the present disclosure
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.
DETAILED DESCRIPTION
[0011] In describing embodiments illustrated in the drawings, specific terminology is employed
for the sake of clarity. However, the disclosure of this patent 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 operate in a similar
manner and achieve similar results.
[0012] Although the embodiments are described with technical limitations with reference
to the attached drawings, such description is not intended to limit the scope of the
disclosure and all of the components or elements described in the embodiments of this
disclosure are not necessarily indispensable.
[0013] Referring now to the drawings, embodiments of the present disclosure are described
below. In the drawings for explaining the following embodiments, the same reference
codes are allocated to elements (members or components) having the same function or
shape and redundant descriptions thereof are omitted below.
[0014] Referring now to the drawings, embodiments of the present invention are described
below. In the drawings for explaining the following embodiments and examples, the
same reference codes are allocated to elements (members or components) having the
same functions or shapes and redundant descriptions thereof are omitted below.
[0015] A conveyed-material conveyance apparatus 130 including a conveyed-material separation
device according to an embodiment of the present invention is described with reference
to FIGS. 1 to 4. FIG. 1 is a perspective view of a conveyed-material conveyance apparatus
according to an embodiment of the present invention. FIG. 2 is a perspective view
of an outer appearance of the conveyed-material conveyance apparatus of FIG. 1. FIG.
3 is a schematic view of a separation stage of a conveyed material in the conveyed-material
conveyance apparatus. FIG. 4 is a plan view of the conveyed-material conveyance apparatus
of FIG. 2. In FIGS. 1 to 4, arrows AF indicate directions of air flowing into the
devices.
[0016] As illustrated in FIGS. 1 and 2, a bundle of conveyed materials (hereinafter, conveyed
material bundle) 1 is a plurality of conveyed materials in a stacked state. The conveyed
material bundle 1 is mounted and arranged in a stacked stated on a stack table 136
as a bottom plate in a conveyed-material conveyance apparatus 130. The conveyed materials
to be separated and conveyed in this embodiment are, for example, thin-plate or sheet
materials separatable and conveyable by the conveyed-material conveyance apparatus.
Examples of the conveyed materials include resin, front/rear surface protector papers,
electronic circuit board materials processed with metal foil, such as copper foil,
or plated and electronic circuit board sheets, such as paper, special film, plastic
film, and prepreg. Examples of the prepreg include a sheet-like reinforced plastic
molding material made of a fiber reinforcing material, such as carbon fiber or glass
cloth. The fiber reinforcing material is impregnated with a thermoplastic resin or
the like by mixing additives, such as a curing agent or a coloring agent, in the fiber
reinforcing material, and heated or dried to a semi-cured state.
[0017] Each of the conveyed-materials to be used has, for example, a width of from about
100 mm to 700 mm and a thickness of from about 0.02 mm to 0.2 mm. The conveyed materials
that can be used in this embodiment have, for example, a width dimension of about
210 mm in a width direction of the conveyed materials (conveyed-material width direction)
indicated by arrow Y in FIG. 1, and a length of about 297 mm in a conveyance direction
indicated by arrow X in FIG. 1. Such relatively small-sized conveyed materials can
be separated and conveyed in the structure of the reference example. Note that the
above-described width, length, and thickness of the conveyed material are only examples.
In some embodiments, widths, lengths, and thicknesses other than the above-described
range may be used. Here, the conveyance direction X corresponds to a direction of
conveyance of the conveyed material. A vertical direction of the conveyed materials
indicated by arrow Z in FIG. 1 corresponds to a direction in which the conveyed materials
are stacked one on another. The width direction Y of the conveyed material corresponds
to a direction perpendicular to each of the conveyance direction X and the vertical
direction Z of the conveyed material.
[0018] The stack table 136 may also be referred to as a supply table and functions as a
preparation unit to prepare the conveyed materials in the stacked state. The stack
table 136 is movable in the vertical direction Z by an elevation assembly as a conveyed-material-stacker
driving device. The conveyed-material conveyance apparatus 130 includes a conveyed-material
sensor 20 (illustrated in FIG. 3) and a conveyed-material position controller. The
conveyed-material sensor 20 as a conveyed-material detector detects a position of
the upper surface of the conveyed material bundle 1. The conveyed-material position
controller controls the operation of the elevation assembly to adjust the position
of the upper surface of the conveyed material bundle 1. When the upper surface of
the bundle 1 of the conveyed materials on the stack table 136 comes to a predetermined
height position detected by the conveyed-material sensor 20, a conveyed material 1A
placed at the uppermost position is separated and conveyed through the movement described
later.
[0019] The conveyed-material conveyance apparatus 130 includes a pair of side fences 137
as a pair of conveyed-material position regulators, a front end guide plate 138, and
end fences 139. The side fences 137 are disposed on both sides of the stack table
136 in the width direction Y of the conveyed materials to position the conveyed material
bundle 1 in the width direction Y of the conveyed materials crossing (or perpendicular
to) the conveyance direction X of the bundle 1 of the conveyed materials. The front
end guide plate 138 positions the front end of the bundle 1 of the conveyed materials
in the length direction which is equivalent to the conveyance direction X. The end
fences 139 also position the rear end of the bundle 1 of the conveyed materials in
the length direction. The side fences 137 are movable in the width direction Y of
the conveyed material bundle 1 in accordance with the width of the conveyed materials.
The end fences 139 are movable in the conveyance direction X of the conveyed material
bundle 1 in accordance with the width of the conveyed materials.
[0020] Side air nozzles 370 indicated in broken lines and provided on one side of the side
fences 137 (in the far left of FIG. 2), functions as a second air jetting unit being
an isolation blower or an air jetting device, to jet and blow side air Ac (see FIG.
4) to the side end of the conveyed material bundle 1. As illustrated in FIG. 4, the
side air nozzles 370 are disposed on both the side fences 137 and connected to a side
blower 380 as a side air generator or a side air blower to generate side air Ac. A
centrifugal blower, such as a sirocco fan, is used as the side blower 380. Alternatively,
an axial blower may also be used.
[0021] As illustrated in FIGS. 1 to 4, a conveyed-material floating-retaining-conveying
device 160 includes a drive roller 162, a driven roller 163, a conveyance belt 161,
a negative pressure air chamber 310, and a suction blower 390. As illustrated in FIG.
2, the drive roller 162 is driven to rotate in a direction indicated by arrow R1 in
FIG. 2 about a drive shaft 162s that is connected to a drive motor as a belt conveying
unit. The driven roller 163 is formed unitarily with a rotatably supported driven
shaft, and rotates in a direction indicated by arrow R2 in FIG. 2 according to the
rotation and movement of the conveyance belt 161 by the drive roller 162. The conveyance
belt 161 is an endless belt member in which many suction holes are formed, with each
hole connecting to the negative pressure air chamber 310. The negative pressure air
chamber 310 is coupled with an external suction blower 390 via a suction duct, which
is described later, and kept at a negative pressure state by suction of air from the
external suction blower 390 to suck and attract the uppermost conveyed material 1A
via the suction holes of the conveyance belt 161.
[0022] The suction blower 390 has a function as a suction air generator to generate suction
air Ad. A centrifugal blower, such as the sirocco fan, is used as the suction blower
390, but an axial blower may also be used alternatively. The centrifugal blower (sirocco
fan) having a multiblade fan is small and reasonable in cost, and is also advantageous
in that a large pressure increase can be achieved easily in a single stage at a lower
noise level, when compared to the axial blower. As described above, the conveyance
belt 161 of the conveyed-material floating-retaining-conveying device 160 functions
as a retaining unit (retaining member) to attract and retain a floated conveyed-material
by a negative pressure generated by air suction to separate the floated conveyed-material
from other conveyed materials and a conveyor to convey the retained conveyed-material.
Note that the size of the conveyed-material floating-retaining-conveying device 160
may be increased in accordance with the size of the conveyed material.
[0023] An air jetting nozzle device 300 that also functions as an air blower is disposed
at a position facing the front end of the mounted bundle 1 of the conveyed materials.
The air jetting nozzle device 300 includes an air chamber 320 that stores air fed
from an external floating blower in a pressurized manner. As illustrated in FIGS.
3 and 4, the air chamber 320 includes two floating nozzles 322. The floating blower
functions as a floating air blower or a floating air generator to generate floating
air. For example, a centrifugal blower, such as the sirocco fan, is used as the suction
blower. Alternatively, an axial blower may also be used as the floating blower.
[0024] As described above, the air jetting nozzle device 300 functions as an air jetting
device to blow air to conveyed materials stacked and prepared on the stack table 136
to float an end of the conveyed materials. Examples of air, or gas, include a diselectrified
air or other gases used for floating and separating the conveyed materials one after
another. In particular, for conveyed materials containing carbon fibers, the conveyed
materials in the stacked state are in close contact with each other due to electrostatic
action, it is difficult to separate the conveyed materials from each other one by
one. It is effective, therefore, to blow the diselectrified air to the bundle 1 of
the conveyed materials in the stacked state.
[0025] As illustrated in FIG. 3, the floating nozzles 322 blow a floating air Aa toward
an end portion on the front (referred to as the front end portion hereinafter) of
the bundle 1 of the conveyed materials to float a conveyed material from the bundle
1 of the conveyed materials. The floating nozzles 322 functions as a first air jetting
unit to blow air to the conveyed material bundle 1 stacked in a direction opposite
to the conveyance direction X to float and separate the conveyed materials. Note that,
when warm air is used as the blowing air, an effect of dehumidifying the conveyed
materials can be further obtained, thus allowing more effective separation and isolation
of the conveyed materials.
[0026] FIG. 5 is a flowchart of main steps performed by the conveyed-material conveyance
apparatus according to an embodiment of the present invention. FIGS. 6A, 6B, 6C, 7A,
and 7B are illustrations of an operational transition by the conveyed-material conveyance
apparatus. First, the structure and operation of the conveyed-material conveyance
apparatus 130 is further described with reference to FIG. 6A. As illustrated in FIG.
6A, the conveyed-material conveyance apparatus 130 blows floating air Aa from the
floating nozzles 322 of the air chamber 320 toward a front end face of the conveyed
material bundle 1 stacked on the stack table 136, to float the conveyed material bundle
1 up to the height of the conveyance belt 161 (conveyed-material retainer).
[0027] The suction blower 390 is then operated to retain the conveyed material 1A, which
is the uppermost sheet of the bundle 1 of the conveyed materials, by the conveyance
belt 161. The uppermost conveyed material 1A retained on the conveyance belt 161 is
not always separated as a single sheet, but one or more conveyed materials may be
in close contact with the conveyed material 1A. Hence, the side air nozzles 370, which
are disposed as the isolation blowers on the side fences 137, blow the side air to
isolate the conveyed material 1A retained by the conveyance belt 161 from other conveyed
materials to be a single sheet. The term "isolation" represents jetting air from the
side air nozzles to reduce the attractive force acting between conveyed materials
to assist separation. Then, the conveyed material 1A is conveyed to the destination
of conveyance by the conveyance belt 161, and subsequent processing is performed.
[0028] A conveyed-material stopper 177 is disposed between the air chamber 320 and the bundle
1 of the conveyed materials mounted on the top to prevent conveyance of the conveyed
materials other than the uppermost conveyed material 1A. A conveyed-material sensor
20 to detect the height of the conveyed material is provided to keep a fixed distance
h between the conveyance belt 161 and the position of the top surface of the conveyed
materials, although the distance h tends to decrease due to feeding and sending of
the conveyed materials. The conveyed-material sensor 20 is a reflection-type photosensor.
The conveyed-material-stacker driving device (elevation assembly) raises and adjusts
the stack table 136 in response to detected signals of the conveyed-material sensor
20.
[0029] The bundle 1 of the conveyed materials are aligned, with the front end face being
a reference surface, to fit the size of the conveyed materials on the stack table
136. A sheet feeding sensor 179 to detect the arrival of the conveyed materials is
disposed at a downstream side in the conveyance direction X in the conveyed-material
floating-retaining-conveying device 160.
[0030] Next, operation and process steps of the conveyed-material conveyance apparatus 130
are described sequentially. (1) A preparation step (step S1 of FIG. 5) for preparing
the conveyed materials in a stacked state is performed, for example, in the following
manner. Specifically, an operator stacks the bundle 1 of the conveyed materials on
the stack table 136. At the same time, the operator hits the front end face of the
bundle 1 of the conveyed materials against the front end guide plate 138 to form a
reference surface to allow the bundle 1 of the conveyed materials to be set and aligned
conforming to the size of the conveyed materials. Further, the side fences 137 and
the end fences 139 are manipulated to align the side end faces and the rear end face,
respectively, of the bundle 1 of the conveyed materials. In the preparation step,
robots or other specialized devices, for example, may perform the stacking or size-alignment
operation of the conveyed material bundle 1, as mentioned above, instead of the human
operator.
[0031] When a conveyed-material feeding instruction is received from the controller of the
conveyed-material conveyance apparatus 130 of FIG. 1, as illustrated in FIG. 6B, the
air chamber 320 of the air jetting nozzle device 300 and the isolation blower including
the side air nozzles 370 operate. Then, the floating step as a first step to blow
air to the end portions of the conveyed materials starts (step S11 of FIG. 19). When
the floating blower of the air chamber 320 and the side blower 380 of the side air
nozzles 370 operate, floating air Aa is blown from the floating nozzles 322 of the
air chamber 320 and side air Ac is blown from the side air nozzles 370. Thus, the
contact areas between the uppermost conveyed materials 1A, 1B, and 1C are changed
by floating uppermost conveyed materials 1A, 1B, and 1C prepared on the stack table
136.
[0032] At the same time, a retaining step (step S3 of FIG. 9) as a second step to retain
the floated conveyed materials starts to suction air by the conveyance belt 161. The
uppermost conveyed material 1A is floated, attracted, and retained on the conveyance
belt 161, as illustrated in FIG. 6B. In FIG. 6B, the term AD parenthesized following
the air chamber 320 or the conveyance belt 161 represents that the air chamber 320
is in blowing operation state or the conveyance belt 161 is in sucking operation state.
The term ST parenthesized following the conveyance belt 161 represents that the conveyance
belt 161 is in stopped state.
[0033] The isolation step indicated by step S4 of FIG. 5 is a step of isolating the conveyed
materials retained by the conveyance belt 161 and performed by the isolation blower
including the side air nozzles 370.
(2) As illustrated in FIG. 6C, the conveyance belt 161 and the conveyance rollers
178 start to operate, and a conveyance step (step S5 of FIG. 5) as a third step to
convey the conveyed material 1A retained by the conveyance belt 161 is executed. In
FIG. 6C, the term DR parenthesized following the conveyance belt 161 represents that
the conveyance belt 161 is in rotational conveyance driving state.
(3) As illustrated in FIG. 7A, the rotational conveyance driving of the conveyance
belt 161 is stopped after the conveyed material 1A exits from the conveyance belt
161 after the conveyed material 1A has reached the sheet feeding sensor 179 and a
predetermined time has passed. (4) Immediately after the conveyed material 1A has
passed through a retaining region retained by the conveyance belt 161, as illustrated
in FIG. 7B, the next conveyed material 1A is floated by blowing of the air and retained
by the conveyance belt 161.
(5) The operation of the conveyance belt 161 is restarted according to the setting
of a conveyed-material feeding interval and the conveyed material 1A is fed. (6) Subsequently,
the steps illustrated in FIGS. 6B to 6B are repeated to convey the conveyed materials
sequentially.
[0034] The floating amount or the isolation state of the conveyed materials differs depending
on thickness, weight, or size of the stacked conveyed materials when the air volume
is fixed at a certain value. For example, if the floating amount of the conveyed materials
is small, no supply (no feed) of the conveyed materials occurs. In contrast, if the
conveyed material is floated exceedingly, the conveyed materials come in close contact
with each other to cause the multifeed. If the power of the suction blower 390 is
small, the conveyed materials cannot be conveyed successfully, and the no-supply also
occurs.
[0035] To properly execute feeding of the conveyed materials, the air volume is previously
fixed according to the stacked conveyed materials, such that the fixed air volume
is reached automatically when the user or operator chooses the conveyed material to
be fed. The air volume is adjusted according to a duty ratio of the blower.
[0036] In the case in which circuit board sheets are used as the conveyed materials, for
example, a circuit board produced with a damaged circuit board sheet would have a
failure in electrical characteristics (resistance values). Therefore, there is a problem
to be solved that the separation of circuit board sheets should be performed while
preventing occurrence of a failure in electrical characteristics (resistance values)
of separated circuit board sheets. For the problem to be solved, the following effects
can be achieved by the following technical configurations of the above-described embodiment.
[0037] According to a first technical configuration of the above-described embodiment, a
conveyed-material separation method includes the preparation step, such as step S1,
to prepare circuit board sheets, such as the conveyed material bundle 1 constituted
of circuit board sheet, in the stacked state, a first step as the floating step, such
as step S2, to float an end of the circuit board sheets by jetting air from the air
jetting device or air jetting unit, such as the air jetting nozzle device 300, and
a second step as the retaining step, such as step S3, to retain and separate the floated
circuit board sheets by the retainer, such as the conveyance belt 161. According to
the first technical configuration of the above-described embodiment, the effect is
achieved of providing the conveyed-material separation method capable of easily separating
the circuit board sheets without reducing qualities of the circuit board sheets. For
example, a circuit board produced with a damaged circuit board sheet would have a
failure in electrical characteristics (e.g., resistance values). By contrast, the
above-described embodiment provides the conveyed-material separation method capable
of easily separating the circuit board sheets without reducing qualities of the circuit
board sheets, thus preventing such a failure of the circuit board.
[0038] The above-described embodiment also have a technical configuration relating to a
conveyed-material separation method employing the air jetting device, such as the
air jetting nozzle device 300, to jet air in a direction opposite a conveyance direction,
such as the conveyance direction X, of the conveyed materials, the first air blower,
and the second air jetting unit, such as the side air nozzles 370, to jet air in a
width direction, such as the width direction Y, perpendicular to the conveyance direction.
[0039] In the conveyed-material separation method according to the above-described embodiment,
the retaining step (the second step) also includes the isolation step, such as step
S4, to isolate conveyed materials by the second air jetting unit. The conveyed-material
separation method according to the above-described embodiment also has a technical
configuration of stopping air jetting from the air jetting unit after the retaining
step (the second step) ends.
[0040] In the conveyed-material separation method according to the above-described embodiment,
the retainer, such as the conveyance belt 161, attracts and retains a floated conveyed
material by air suction. The conveyed-material separation method according to the
above-described embodiment also has a technical configuration of controlling the stack
table, such as the stack table 136, to elevate up and down so that the position of
the upper surface of conveyed materials stacked on the stack table that stack the
conveyed materials thereon and can elevate up and down in the direction in which the
conveyed materials are stacked. According to the above-described embodiment, the effect
is achieved of providing the conveyed-material separation method capable of easily
and reliably separating conveyed materials without reducing qualities of the conveyed
materials.
[0041] According to the above-described embodiment, the conveyed-material conveyance method
employing the conveyed-material conveyance apparatus has a technical configuration
including the third step as the conveyance step, such as step S5, to convey the retained
conveyed material. According to the above-described embodiment, the effect is achieved
of providing the conveyed-material conveyance method capable of reliably conveying
the separated circuit board sheet.
[0042] The above-described embodiment has a technical configuration according to the conveyed-material
separation device that includes the preparation unit, such as the stack table 136,
to prepare conveyed materials, such as the conveyed material bundle 1, the air jetting
device, such as the air jetting nozzle device 300, to jet air the conveyed materials
prepared and stacked to float an end of the conveyed materials, and the retaining
unit and the retainer, such as the conveyed-material conveyance apparatus 130, to
retain and separate the floated conveyed materials.
[0043] The above-described embodiment has a technical configuration in that the conveyed-material
conveyance apparatus includes the conveyed-material separation device according to
any one of the above-described technical configurations and the conveyance unit, such
as the conveyance belt 161, to convey the retained conveyed materials. According to
the above-described embodiment, the effect is achieved of providing the conveyed-material
conveyance apparatus capable of reliably conveying the separated conveyed material.
[0044] However, if it is desired to increase the supplying speed of the conveyed materials,
the air blow needs to be executed before the completion of the conveyance of the first
conveyed material 1A. This may lead to the occurrence of the multifeed due the contact
caused by the over-floating or behavioral disturbance during the blowing. In addition,
the separation may also be difficult when the conveyed materials have large widths.
In view of the above, an embodiment which will be described below has created a conveyed-material
separation device capable of easily separating the conveyed materials according to
the size, such as the widths, of the conveyed materials and a conveyed-material conveyance
apparatus including the conveyed-material separation device.
Embodiment 1
[0045] Next, the conveyed-material conveyance apparatus including the conveyed-material
separation device according to Embodiment 1 of the present invention is described
below by focusing on differences from the conveyed-material conveyance apparatus 130
according to the above-described embodiment. FIG. 8A is a perspective view illustrating,
in a partly schematic manner, a conveyed-material conveyance apparatus including a
conveyed-material separation device according to Embodiment 1 of the present invention.
In FIG. 8A, for example, retaining conveyance units 3A to 3F, suction units 6A to
6C, a multifeed detecting sensor 5, an ionizer 7, a laser feed monitor 8 are schematically
illustrated. In FIG. 8A, a conveyed material 1 is illustrated intentionally in a transparent
manner for easier understanding of front nozzle units 2A, 2B, and 2C, suction units
6A to 6C, and return nozzle units 9A and 9B that are positioned below the conveyed
material 1 that is being conveyed.
[0046] Embodiment 1 mainly differs from the above-described embodiment illustrated in FIGS.
1 to 7B in that a conveyed-material conveyance apparatus 100 illustrated in FIG. 8A
is used instead of the conveyed-material conveyance apparatus 130 illustrated in,
for example, FIGS. 1, 2, 4, 6, and 7. The other portions of the structure are similar
to those of the above-described embodiment (this also applies to other embodiments
described later, such that the notice like this will not be repeated hereinafter).
The conveyed-material conveyance apparatus 100 mainly differs from the conveyed-material
conveyance apparatus 130 in that the conveyed-material conveyance apparatus 100 includes
a configuration described below capable of separating conveyed materials for conveyance
according to size, including width, of the conveyed materials. Regarding the size
of the conveyed materials, a large size is about 700 mm × about 700 mm, an intermediate
size is about 420 mm × about 594 mm, and a small size is about 210 mm × about 297
mm.
[0047] First, the conveyed-material conveyance apparatus 100 uses a plurality of (three
in Embodiment 1) front nozzle units 2A, 2B, and 2C, which are provided as common air
jetting devices and floating units, in place of the single air jetting nozzle device
300. The front nozzle units 2A, 2B, and 2C are detachably attachable relative to the
front end guide plate 138 in accordance with the width dimension of the conveyed materials.
[0048] Secondly, the conveyed-material conveyance apparatus 100 uses a plurality of (six
in Embodiment 1) retaining conveyance units 3A to 3F, which are provided as common
retaining units, in place of the single conveyed-material floating-retaining-conveying
device 160. The retaining conveyance units 3A to 3F are detachably attachable relative
to an upper body frame 101b according to the width dimension of the conveyed materials.
The retaining conveyance units 3A to 3F have a unique configuration of attracting
and retaining the conveyed materials, compared to the conveyed-material floating-retaining-conveying
device 160, which will be further described later.
[0049] Thirdly, the conveyed-material conveyance apparatus 100 uses a plurality of (two
in Embodiment 1) return nozzle units 9A and 9B that are provided as suction units
to suck and attract the floated conveyed materials in a direction opposite to the
floating direction, after the conveyed materials are attracted and retained by the
retaining conveyance units 3A to 3C. The return nozzle units 9A and 9B will be further
described later.
[0050] Fourth, the conveyed-material conveyance apparatus 100 differs from the conveyed-material
conveyance apparatus 130 in that the two side fences 137 illustrated in, e.g., FIGS.
2 and 4 are disposed at each of an upstream side and a downstream side in the conveyance
direction X, that is, the conveyed-material conveyance apparatus 100 includes a total
of four side fences 137. In the conveyed-material conveyance apparatus 100, a plurality
of (two in Embodiment 1) common side nozzle units 11A and 11B is used in place of
the pair of side air nozzles 370 disposed on the pair of left an right side fences
137 illustrated in FIGS. 2 and 4. The side nozzle units 11A and 11B are detachably
attached relative to the side fences 137 via a screw as a fastener or an attachment-detachment
member according to the width of the conveyed materials. The side nozzle units 11A
and 11B function as the second air jetting unit being an isolation blower or an air
jetting device to jet and blow side air to a side end of the conveyed material bundle
1. The side nozzle units 11A and 11B include, for example, side air nozzles 370 and
a side blower 380 similar to those illustrated in, e.g., FIGS. 4 and 7. The side nozzle
unit 11A is detachably attached relative to the left and right side fences 137 at
the upstream side in the conveyance direction X in FIG. 8A. The side nozzle unit 11B
is detachably attached relative to the left and right side fences 137 at the downstream
side in the conveyance direction X in FIG. 8A. Note that the configuration of the
side nozzle units 11A and 11B are not limited to the above-described configuration
but may be the following configuration. For example, only the side air nozzles 370
are detachably attached relative to the side fences 137 and the side blower 380 is
secured to the body frame 101 in an area outside the range of movement of the side
fences 137 in the width direction of conveyed materials. The side air nozzles 370
and the side blower 380 may be communicated with each other via a flexible duct being
expandable and contractible.
[0051] A difference other than the above-described differences is that the suction units
6A to 6C are additionally provided. Another difference is that the multifeed detecting
sensor 5, the ionizer 7, and the laser feed monitor 8 are additionally provided. The
multifeed detecting sensor 5 is a multifeed detector that detects the presence of
multifeed of the conveyed materials being conveyed. A known ultrasonic sensor, for
example, using ultrasonic waves may be used as the multifeed detecting sensor 5.
[0052] The suction units 6A to 6C are disposed below the conveyed materials being conveyed
and arranged similarly to the conveyed-material floating-retaining-conveying device
160 illustrated in FIG. 1, with the conveyed-material retainer facing upward. The
suction units 6A to 6C attract and retain a conveyed material, which is conveyed by
the retaining conveyance units 3A to 3F, by air suction force and convey the conveyed
material to a further downstream side.
[0053] Reasons that the suction units 6A to 6C are employed are, for example, as follows.
By attracting and conveying the conveyed materials, such as prepregs, by the suction
units 6A, 6B, and 6C disposed downstream from the retaining conveyance units 3A, 3B,
and 3C, pressed marks or damage are less given to the conveyed materials than a configuration
in which the conveyed materials, such as prepregs, are pressed and conveyed by, e.g.,
a roller. Thus, such a problem of conveyance specific to material sheets used for
electronic circuit board materials can be resolved. In a case in which a component,
such as glass fiber, is contained in the conveyed materials, the glass fiber may become
powdery, and separated and scattered from the end portions (front and rear end portions
and lateral end portions) of the conveyed materials. One reason that the suction units
6A to 6C are employed is to prevent powder substances, such as glass fiber, from adhering
to a conveyance roller and damaging and degrading a surface of the conveyance roller,
for example, in a configuration in which the conveyance roller employs a friction
rotation system and is disposed downstream from the retaining conveyance units 3A
to 3F to convey the above-described type of conveyed materials. Such a configuration
also prevents a conveyed material subsequently conveyed from being damaged by powder
substances, such as glass fiber, adhering to and remaining on the surface of the conveyance
roller. The ionizer 7 is a unit or a device to diselectrify the conveyed materials
being conveyed. The laser feed monitor 8 is a unit or a device to measure skew of
the conveyed materials being conveyed.
[0054] A configuration of the front nozzle units 2A, 2B, and 2C is similar to the configuration
of the air jetting nozzle device 300 according to the above-described embodiment illustrated
in FIGS. 1 to 4. Common specifications in, e.g., the shape, attachment dimensions,
internal components, and blowers, are employed for the front nozzle units 2A, 2B,
and 2C. The front nozzle units 2A, 2B, and 2C are detachably attached relative to
the front end guide plate 138 via a screw 102 as a fastener or an attachment-detachment
unit, in accordance with the width of the conveyed materials. The front end guide
plate 138 is secured to the body frame 101 with a fastener, such as a screw. The front
end guide plate 138 includes a plurality of screw holes 103 as an attachment-detachment
unit to attach and detach the front nozzle units 2A, 2B, and 2C in accordance with
the width of the conveyed materials. For simplification of illustration, the front
nozzle unit 2C is illustrated as an example in which one screw 102 is used and fastened
into one screw hole 103. Actually, however, the front nozzle units 2A, 2B, and 2C
are fastened with more than one screws at more than one positions, respectively, so
as to be reliably secured to the front end guide plate 138. The fastener or the fastening
member is not limited to the screw 102, and may be, for example, a clamp member capable
of fastening and releasing fastening in one-touch operation.
[0055] Common specifications in, e.g., shape, internal components, and blowers, are employed
for the six retaining conveyance units 3A to 3F. The six retaining conveyance units
3A to 3F are detachably attached relative to an upper body frame 101b, which is secured
to an upper portion of the body frame 101, with the screw 102 in accordance with the
width of the conveyed materials. A plurality of screw holes 103 is formed in the upper
body frame 101b to attach the retaining conveyance units 3A to 3F, in accordance with
the width of the conveyed materials. For simplification of illustration, the retaining
conveyance unit 3A is illustrated as an example in which one screw 102 is used and
fastened into a single screw hole 103. Actually, the retaining conveyance units 3A
to 3F are fastened with more than one screws at more than one positions, so as to
be reliably secured to the upper body frame 101b. The fastener or the fastening member
is not limited to the screw 102, and may be, for example, a clamp member capable of
fastening and releasing fastening in one-touch operation.
[0056] The body frame 101 functions as a body of the conveyed-material separation device
provided as a structural body. A pair of body side plates as a structural body is
disposed on the body frame 101 with the two side fences 137 on each of the right and
left sides interposed in between the pair of body side plates. The pair of body side
plates is fixedly attached to both sides of the body frame 101 in the conveyance direction
X. On the body side plates, the upper body frame 101b is provided as a structural
body and fixedly attached. In FIG. 8A, a state is illustrated in which the pair of
body side plates are removed. For example, the upper body frame 101b may be prepared
in different sizes corresponding to the number of retaining conveyance units 3A to
3F that are detachably attached relative to the upper body frame 101b. In addition,
securing positions of the body side plates to be secured on the body frame 101 may
be changed. As a result of this, various combinations of the retaining conveyance
units are attachable. The attachment of the retaining conveyance units 3A to 3F to
the upper body frame 101b is not limited to the above-described configuration. For
example, a plurality of screw holes commonly usable for the upper body frame 101b
may be formed corresponding to positions at which the retaining conveyance units 3A
to 3F are selectively attached.
[0057] For example, with the above-described detachably attachable configuration of the
front nozzle units 2A, 2B, and 2C and the retaining conveyance units 3A to 3F, the
following arrangement and operational use are available in FIG. 8A. For example, when
small-sized conveyed materials are used, only the front nozzle unit 2B and the retaining
conveyance unit 3B, which are disposed in the center of the conveyed material, are
attached and used with other front nozzle units and the retaining conveyance units
removed. When large-sized conveyed materials are used, all of three front nozzle units
2A, 2B, and 2C and all of the six retaining conveyance units 3A to 3F are attached
and used, as illustrated in FIG. 8A. When medium-sized conveyed materials are used,
two adjacent front nozzle units 2A and 2B or two adjacent front nozzle units 2B and
2C, and corresponding adjacent retaining conveyance units 3A, 3B, 3D and 3E or adjacent
retaining conveyance units 3B, 3C, 3E, and 3F are attached and used at appropriate
positions in the width direction Y of the medium-sized conveyed material. Thus, in
the conveyed-material conveyance apparatus 100, the retaining conveyance units 3A
to 3F are used as at least one retaining unit or a plurality of retaining units, and
the positions of such retaining units can be changed according to the width of the
conveyed material in the width direction Y of the conveyed material perpendicular
to the floating direction of the conveyed material. With the above-described detachably
attachable configuration, the side nozzle units 11A and 11B are also arranged and
driven for use, under a technical thought similar to that of the front nozzle units
2A, 2B, and 2C and the retaining conveyance units 3A to 3F.
Example 1
[0058] The following table 1 shows a relationship of arrangement of the retaining conveyance
units 3A to 3F, the side nozzle units 11A and 11B, and the front nozzle units 2A,
2B, and 2C. FIGS. 8B to 8G are plan views of examples of the arrangement of the units
of Embodiment 1 in table 1. In Table 1, the conveyed-material length L represents
the length of a conveyed material in the conveyance direction X of the conveyed material
(longitudinal dimension). The conveyed-material width W represents the width (lateral
dimension) of a conveyed material in the width direction Y of the conveyed material.
As illustrated in FIG. 1, the numbers and arrangement of the respective units are
associated with each other in accordance with the combination of the range of the
conveyed-material length L and the range of the conveyed-material width W. For example,
the numbers and arrangement of the respective units are associated with each other
as illustrated in FIGS. 8B to 8G with parentheses.
Table 1
| Conveyed-material length L [mm] |
Conveyed-material width W [mm] |
Number of Retaining conveyance units |
Number of Side nozzle units |
Number of Front nozzle units |
Arrangement of Units |
| 250≤L≤350 |
250≤W≤300 |
1 |
2 |
1 |
UA (FIG. 8B) |
| 350<L≤650 |
2 |
4 |
1 |
UB (FIG. 8C) |
| 250≤L≤350 |
300≤W≤420 |
2 |
2 |
2 |
UC (FIG. 8D) |
| 350≤L≤650 |
4 |
4 |
2 |
UD (FIG. 8E) |
| 250≤L≤350 |
420≤W≤650 |
3 |
2 |
3 |
UE (FIG. 8F) |
| 350<L≤650 |
6 |
4 |
3 |
UF (FIG. 8G) |
[0059] In Table 1, for example, a conveyance material having a conveyed-material length
L of 300 mm and a conveyed-material width W of 300 mm is associated with a unit arrangement
of UA (FIG. 8B). In other words, for the unit arrangement of UA, the numbers of the
retaining conveyance units, the side nozzle units, the front nozzle units are 1, 2,
and 1, respectively.
[0060] FIGS. 8B to 8G are examples of the arrangements corresponding to the unit arrangements
of UA, UB, UC, UD, UE, and UF shown in table 1. As illustrated in FIGS. 8B to 8G,
in accordance with the sizes of the conveyed material (the conveyed-material length
L: vertical size, and the conveyed-material width W: horizontal size). Units indicated
by shading and broken line In FIGS. 8B to 8G are units to be operated. The retaining
conveyance units 3A, 3C, 3D, 3E, and 3F indicated by broken lines in FIG. 8B and the
retaining conveyance units indicated by 3A, 3C, 3D, and 3F indicated by broken lines
represent the positions and states in which the respective units are removed from
the upper body frame 101b. In FIGS. 8D, 8E, and 8F, the retaining conveyance units
removed from the upper body frame 101b are omitted for simplicity. Note that the ranges
of the conveyed-material length L and the conveyed-material width W, the numbers of
units, and the arrangements of the respective units are only examples and are not
limited to them.
[0061] The retaining conveyance units 3A to 3F are described by focusing on what differs
from the conveyed-material floating-retaining-conveying device 160 of the above-described
embodiment illustrated in FIG. 1 and so on. Since the retaining conveyance units 3A
to 3F have a common configuration, the retaining conveyance unit 3A is described as
a representative. FIG. 9 is a cross sectional side view of a portion of the retaining
conveyance unit 3A used in Embodiment 1, when seen diagonally from the upper right.
FIG.10 is a perspective view of the retaining conveyance unit 3A when seen diagonally
from a lower right side thereof. FIG. 11 is a perspective view of the air flow of
the suction air of the retaining conveyance unit when seen diagonally from a lower
left side thereof. FIG. 12 is a perspective view of areas retained by conveyance belts
of the retaining conveyance unit.
[0062] The retaining conveyance unit 3A mainly differs from the conveyed-material floating-retaining-conveying
device 160 in that a retaining unit 165 including conveyance belts 161a, 161b, and
161c is used in place of the conveyance belt 161, as illustrated in FIGS. 9 to 11.
The conveyance belts 161 a, 161b, and 161c are formed by dividing a conveyance belt
into three parts to be identical with each other and have the same circumferential
length. The conveyance belt 161a and the conveyance belt 161b that form the retaining
conveyance unit 3A are arranged on both sides of and across the central conveyance
belt 161c in the width direction Y of the conveyed materials. The conveyance belt
161c is stretched over a tension roller 167, a free roller 162c, and a driven roller
163c. The free roller 162c has a diameter smaller than the diameter of a drive roller
162a or a drive roller 162b, and the driven roller 163c has the same diameter as the
diameter of a driven roller 163a or a driven roller 163b. The tension roller 167 is
disposed further above the upper surfaces of the conveyance belts 161a, 161b at a
position closer to the downstream side in the conveyance direction X. The tension
roller 167 is supported rotatably to a unit frame via a shaft 167s. The conveyance
belt 161a is stretched between the drive roller 162a and the driven roller 163a. The
conveyance belt 161b is stretched between the drive roller 162b and the driven roller
163b.
[0063] The drive rollers 162a, 162b and the free roller 162c are mounted on the common drive
shaft 162s. Only the free roller 162c is guided and supported at a predetermined gap
from the drive shaft 162s to allow free rotation. Each of the drive rollers 162a and
162b is integrally molded with the corresponding drive shaft 162s. The driven rollers
163a, 163b, and 163c are integrally molded with and mounted on the common driven shaft
163s. The drive shaft 162s and the driven shaft 163s are supported rotatably to the
unit frame 169, which is the unit body of the retaining conveyance unit 3A, via bearings.
Thus, as illustrated in FIGS. 9 to 11, there is a difference in height in the vertical
direction Z between the belt retaining surfaces of the conveyance belt 161c located
in the center of the width direction Y of the conveyed material and the conveyance
belts 161a and 161b located on both sides of the conveyance belt 161c.
[0064] The drive shaft 162s is coupled with a drive motor 168, which is a conveyance belt
drive unit, via a teethed pulley and a teethed belt, both of which function as rotation
transmitters. The drive motor 168 is secured to the unit frame 169 via a motor mount
fixed to the unit frame 169, to drive and rotate the conveyance belts 161a and 161b
via the drive rollers 162a and 162b. The conveyance belt 161c is driven by the rotational
force of the driven roller 163c that is driven to rotate in accordance with the rotation
of the conveyance belts 161a, 161b. Thus, the conveyance belts 161a, 161b, and 161c
are run to rotate at the same circumferential speed in the same rotational direction
indicated by arrows in FIG. 9.
[0065] As illustrated in FIGS. 10 to 12, a plurality of suction holes 164 is formed in the
conveyance belts 161a, 161b, and 161c to retain the conveyed material. Note that,
in FIGS. 10 to 12, the suction holes 164 are illustrated as if the suction holes 164
are formed at a portion of a lower side of the conveyance belts 161 a, 161b, and 161
c. However, in this example, the conveyance belts 161 a, 161b, and 161c are formed
over the whole circumference of each of the conveyance belts 161 a, 161b, and 161c
c
[0066] As illustrated in FIG. 11, the suction blower 390 is driven to generate the air flow
of the suction air Ad. Both a suction duct 311 connected to the suction blower 390
and a negative pressure air chamber 310 connected to the suction duct 311 come to
a negative pressure state. As a result, the suction air Ad is sucked from the suction
holes 164 of the conveyance belts 161 a, 161b, and 161c to attract and retain the
conveyed material on the belt retaining surfaces of the conveyance belts 161a, 161b,
and 161c. As illustrated in FIG. 12, a retaining area 166, which is illustrated in
a transparent manner, for retaining the conveyed material is formed on the retaining
conveyance unit 3A in the width direction Y of the conveyed material. The retaining
area 166 corresponds to an area where many suction holes 164 are formed in the conveyance
belts 161a, 161b, and 161c.
[0067] Next, return nozzle units 9A, 9B are described with reference to FIG. 13. FIG. 13
is a back view of an arrangement of the return nozzle units. Note that floating air
Aa illustrated in FIG. 13 is generated with a floating blower 330, is stored in the
air chamber 320, and is jetted from the two floating nozzles 322. Since the return
nozzle units 9A and 9B have a common configuration, the return nozzle unit 9A is described
as a representative. The return nozzle unit 9A includes a return nozzle 9b with an
opening 9a to suck the return air Ar formed therein and a return air suction blower
9c connected to the return nozzle 9b. The sirocco fan, for example, may be used as
the return air suction blower 9c. As illustrated in FIGS. 8A and 13, the return nozzle
units 9A and 9B are disposed between two adjacent units of the front nozzle units
2A, 2B, and 2C. Specifically, the return nozzle units 9A and 9B are disposed between
the retaining conveyance units 3A and 3B and between the retaining conveyance units
3B and 3C, respectively, in the width direction Y of the conveyed material.
[0068] Next, operation of Embodiment 1 is described by referring to FIGS. 8A and 14 to 16.
FIG. 14 is an illustration of steps to be executed by the conveyed-material conveyance
apparatus of Embodiment 1. Specifically, FIG. 14 is a flowchart of start timing of
driving of various types of air. FIG. 15 is a front view of the conveyed-material
separation device in a state in which conveyed materials are isolated and separated
with the conveyed-material separation device and attracted and retained by one of
the plurality of retaining conveyance units. FIG. 16 is a schematic view of action
of return air in Embodiment 1. Note that, in the retaining step described later, as
illustrated in FIG. 16, the suction blowers 390 of all of the six retaining conveyance
units 3A to 3F are operated. However, FIG. 15 shows, as a representative, the state
in which the conveyed material 1A is attracted and retained with the retaining conveyance
unit 3A.
[0069] Next, operation and process steps of the conveyed-material conveyance apparatus 100
are described subsequently, in which similar descriptions already given in connection
with the embodiments with reference to FIGS. 1 to 7 are omitted as much as possible.
It is assumed that the large-sized conveyed materials are used. (1) A preparation
step for preparing the conveyed materials in a stacked state (step S10 of FIG. 14)
is similar to step S1 of the above-described embodiment illustrated in FIG. 5. (2)
When the conveyed-material feeding instruction is received from the controller of
the conveyed-material conveyance apparatus 100 of FIG. 8A, the operation of the isolation
blower starts. The isolation blower includes the floating blower 330 and the side
blower 380 of each of the front nozzle units 2A, 2B, and 2C. Accordingly, the floating
step for blowing the air to the end portions of the conveyed materials starts (step
S11 of FIG. 14). When side air Ac is blown from the four side air nozzles 370 while
floating air Aa is blown from the floating nozzles 322 of the air chamber 320, the
uppermost conveyed materials 1A, 1B, and 1C on the stack table 136 prepared float
up. As a result, the contact area is changed between adjacent conveyed materials of
the uppermost conveyed materials 1A, 1B, and 1C (see the state in which no return
air Ar is blown in FIG. 16A).
(3) At the same time, the retaining step for retaining the floated conveyed materials
starts (step S12 of FIG. 14). The suction blowers 390 at all of the six retaining
conveyance units 3A to 3F are operated to generate the suction air Ad. Air suction
starts by the conveyance belts 161 a, 161b, and 161c (hereinafter simply referred
to as the conveyance belts 161) of the retaining conveyance units 3A to 3F. The uppermost
conveyed material 1A is floated and, in the state in which the return air Ar has not
been blown as illustrated in FIG. 16A, the uppermost conveyed material 1A is attracted
and retained by the conveyance belts 161. At this time, the rear end portion of the
conveyed material 1A is securely attracted and retained by the conveyance belt 161
of the retaining conveyance units 3D to 3F disposed on the upstream side in the conveyance
direction X. As a result of this, the contact area and contact time between the rear
end portion of the first conveyed material 1A, which has been attracted and retained
by the conveyance belt 161, and the floating second conveyed material 1B can be minimized.
As described above, even when the glass or the like become powdery and is separated
and flowed from the end portions (the front and rear end portions and the side end
portions) of the conveyed materials 1, the contact between the rear end portion of
the first conveyed material 1A and the second conveyed material 1B can be avoided
as much as possible. Therefore, the damage of the conveyed materials 1A, 1B can be
prevented.
As describe above, In Embodiment 1, the floating air Aa from the floating nozzles
322 and the side air Ac from the side air nozzles 370 are blown simultaneously to
apply the wind pressure uniformly to the bundle 1 of the conveyed materials. As a
result, the overfloat and the behavioral disturbance are suppressed to prevent multifeed
at the beginning of the blowing.
(4) Subsequently, after the first conveyed material 1A is attracted and retained by
the conveyance belts 161 of the retaining conveyance units 3A to 3F, the return air
suction blowers 9c of the return nozzle units 9A and 9B are operated to generate the
return air Ar. The return air Ar sucks the floated second and subsequent conveyed
materials 1B, 1C at the end portions, which are located on the downstream side of
the conveyance direction X, in a direction opposite to the floating direction, to
thereby increase the gap between the floated second and subsequent conveyed materials
1B and 1C (see the portions surrounded by broken lines in FIG. 16B). Since the space
is formed between the conveyed materials 1B and 1C by increasing the gap between the
floated second and subsequent conveyed materials 1B and 1C, the next floating air
Aa used for floating, attracting, and retaining of the second conveyed material 1B
can easily come into the space between the conveyed materials 1B and 1C. As a result
of this, the separating performance of the two and subsequent conveyed materials 1B
and 1C can be significantly improved by the return air Ar of the return nozzle units
9A and 9B. Since the return air Ar includes (or sucks), as illustrated in FIG. 16A,
circumferential stagnated air, the influence caused by the disturbance of air can
be decreased.
Simultaneously, the four side blowers 380 are operated to execute an isolation step
(step S13 of FIG. 14) to blow the side air Ac from the four side air nozzles 370 to
the side-end portions of the floated second and subsequent conveyed materials 1B,
1C. The first conveyed material 1A retained by the conveyance belts 161 is clearly
isolated from the second and subsequent conveyed materials 1B and 1C, to thereby prevent
the defect, such as the multifeed or no supply, and perform the separation of the
conveyed materials easily and securely.
(5) In FIG. 8A, the conveyance belts 161 and the suction units 6A to 6C start to operate
to execute a conveyance step for conveying the conveyed material 1A retained by the
conveyance belts 161 (step S14 of FIG. 14). After the conveyed material 1A has reached
the sheet feeding sensor 179, the rotational conveyance operation of the conveyance
belts 161 is stopped. Below, the operation that are substantially similar to the operation
of the above-described embodiment is performed to subsequently convey the conveyed
materials.
[0070] The floating step described in the above-described (1) and (2) above is additionally
described. When floating air Aa is blown from the floating nozzles 322 of the front
nozzle units 2A, 2B, and 2C of FIG. 13 and side air is blown from the side air nozzles
as described above, the conveyed material 1A, 1B, and 1C float and separate as illustrated
in FIG. 15. When the conveyed material 1A, 1B, and 1C float and separate, the above-described
retaining step is started. Thus, the suction blowers 390 of all of the six retaining
conveyance units 3A to 3F operate and air suction with the conveyance belts 161a,
161b, and 161c of the retaining conveyance units 3A to 3F starts. For example, taking
an example of the retaining conveyance unit 3A, the sucked and attracted state of
the conveyed material 1A is as follow. For example, as illustrated in FIG. 15, a central
leading end portion 1Ac of the conveyed material 1A is deformed in a curved manner
to project upward (inverted U-shape) by the suction air Ad from the belt retaining
surface of the conveyance belt 161c as a central step portion segmented in the conveyance
belt 161.
[0071] A central left portion 1Aa and central right portion 1Ab corresponding to the left-side
conveyance belt 161a and the right-side conveyance belt 161b, respectively, are retained
on the belt retaining surface within the formation range of the belt retaining surface,
by suction air Ad blown from the belt retaining surface. A left-side leading end portion
1Aaa and a right-side leading end portion 1Abb (the right side of the conveyed material
1A is cut and omitted in FIG. 15) separated away from the belt retaining surface further
hang down toward lateral ends of the conveyed material 1A.
[0072] Since the retaining surface of the retaining conveyance unit 3A does not exist in
the rear end portion 1Ar of the conveyed material 1A, the first conveyed material
1A is disposed approximately horizontally to the belt retaining surface. The air flow
of the side air Ac toward the rear end of the conveyed material 1A keeps the floating
state of the conveyed material 1A and bulges the center of the conveyed material 1A,
such that the conveyed material 1A comes to an upward arch shape (semi-circular shape)
when seen from the rear end portion.
[0073] For the subsequent conveyed material 1B and 1C, as illustrated in FIG. 15, a central
leading end portion thereof is deformed in a curved manner to project upward (inverted
U-shape) by floating air and side air, and floats in such a manner that the leading
end thereof further hangs down toward lateral ends thereof by its own weight. The
floating and separated state illustrated in FIG. 15 is just an example in which a
conveyed material of a type has a thickness of from 0.02 mm to 0.2 mm. Although depending
on the material type, for example, as the thickness approaches 0.02 mm and is smaller,
the degree of the above-described curve is greater. By contrast, as the thickness
approaches 0.2 mm and is greater, the degree of the above-described curve is smaller
and the conveyed material floats in a state closer to a horizontal state. When the
side air does not act on the second and subsequent conveyed materials 1B and 1C, the
conveyed materials 1B and 1C does not float and are retained similarly to the initial
stacked state.
[0074] In the floating, retaining, and isolation steps described above, a difference in
shape between the first conveyed material 1A and the second conveyed material 1B occurs
as a separated state, and the conveyed materials deform in the belt retaining direction,
thus allowing the conveyed materials to be reliably separated from each other. Accordingly,
the multifeed of the conveyed materials can reliably be prevented.
[0075] During the conveyance of the first conveyed material 1A, the retained shape of the
first conveyed material 1A can be maintained by the retaining force of the belt, while
the shape of the first conveyed material 1A changes every moment during the conveyance
by receiving stress continuously. Therefore, the separation of the conveyed materials
can be facilitated. After floating, the conveyed material is shaped to be away from
the conveyed material having the end portions thereof retained in the retaining step
or the conveyed materials mounted in the stacked state.
[0076] The following effects can be achieved by the technical configurations of Embodiment
1 described above. According to a first technical configuration of Embodiment 1, the
conveyed-material separation device includes the air jetting units, such as the front
nozzle units 2A, 2B, and 2C, to float an end of stacked conveyed materials, such as
the conveyed material bundle 1 stacked, and at least one retaining unit, such as the
retaining conveyance unit 3A, 3B, or 3C, to retain and separate the floated conveyed
materials. The position of the at least one retaining unit is adjustable according
to the width of the conveyed materials in the width direction, such as the width direction
Y, perpendicular to the floating direction of the conveyed-materials. According to
the first technical configuration of Embodiment 1, the conveyed-material separation
device capable of easily separating the conveyed materials according to the width
of the conveyed materials is provided without generating a failure, such as multifeed
or no feed.
[0077] According to a second technical configuration of Embodiment 1, in the conveyed-material
separation device according to the first technical configuration, the at least one
retaining unit is detachably attachable relative to the body, such as the body frame
101, of the conveyed-material separation device. According to a third technical configuration
of Embodiment 1, in the conveyed-material separation device according to the first
or second technical configuration, the at least one retaining unit includes a plurality
of retaining units, such as the retaining conveyance units 3A, 3B, 3C, 3D, 3E, and
3F, and the retaining units constitute a plurality of common units that are detachably
attachable relative to the body of the conveyed-material separation device. According
to the third technical configuration, the number of components constituting the units
and cost can be reduced.
[0078] According to a fourth technical configuration of Embodiment 1, in the conveyed-material
separation device according to the third technical configuration, the plurality of
common units is disposed at three positions corresponding to a center portion and
both end portions of the conveyed material in the width direction on a downstream
side in the conveyance direction of the conveyed materials. According to a fifth technical
configuration of Embodiment 1, in the conveyed-material separation device according
to the fourth technical configuration, the plurality of units is disposed at three
positions including the center and both sides of the conveyed material in the width
direction on the downstream side of the conveyance direction of the conveyed materials.
According to the fifth technical configuration, the conveyed-material separation device
capable of easily separating the conveyed materials according to the width (lateral
dimension) and the length (longitudinal dimension) of the conveyed materials is provided.
In addition, it is possible to prevent damages caused by the rear end portion of the
conveyed material, which is retained by the plurality of units disposed on the upstream
side of the conveyance direction, by coming into contact with the floated conveyed
material or the like.
[0079] According to a sixth technical configuration of Embodiment 1, in the conveyed-material
separation device according to the fourth or fifth technical configuration, the suction
units, such as the return nozzle units 9A and 9B, are included, the suction units
sucking the floated conveyed material in a direction opposite to the floating direction
after the conveyed material is retained by the plurality of units, the plurality of
floating units are disposed corresponding to the plurality of units, and the suction
units are disposed between adjacent floating units of the plurality of floating units
in the width direction. According to the sixth technical configuration, the influence
of disturbance of air is suppressed, and the conveyed materials can be separated easily
and securely.
[0080] Embodiment 1 may also include the following configuration. For example, the four
side fences 137 illustrated in FIG. 8A include the size detectors of the conveyed
materials capable of automatically detecting the width of the conveyed material when
the side end faces of the conveyed material are positioned. The controller provided
in the conveyed-material conveyance apparatus 100 may inform based on the size data
of the conveyed material obtained as a result of the positioning of the lateral direction
of the conveyed material by the four side fences 137. For example, the following notice
or alert may be displayed on a liquid crystal display (LCD) display screen or the
like at an input unit, such as an operation panel disposed at the conveyed-material
conveyance apparatus 100. That is, for example, a message or alert may be displayed
as follow: "The size of the conveyed material is not compatible with the configuration
of the apparatus. Therefore, please remove and attach the front nozzle units 2A, 2B,
and 2C, the retaining conveyance units 3A to 3F, or the return nozzle units 9A and
9B of FIG. 8A." Alternatively, the front nozzle units 2A, 2B, 2C, the retaining conveyance
units 3A to 3F, or the return nozzle units 9A, 9B of FIG. 8A may be automatically
moved rather than being removed and attached by a service operator or a user (such
a modification will be included within the concept of the present invention).
Variation 1 of Embodiment 1
[0081] Variation 1 differs from the above-described Embodiment 1 as follows. For example,
for Variation 1, in a state illustrated in FIG. 8A in which all of the front nozzle
units 2A, 2B, and 2C and the six retaining conveyance units 3A to 3F are attached
and mounted, the conveyed-material conveyance apparatus 100 can separate and convey
a conveyed material of a maximum size usable in the conveyed-material conveyance apparatus
100. The front nozzle units 2A, 2B, and 2C and the six retaining conveyance units
3A to 3F are selectively driven and used according to the size of the conveyed materials
to be used.
[0082] In the variation 1, when small-sized conveyed materials, for example, are used, only
the front nozzle unit 2B disposed in the center of the conveyed material is driven.
When large-sized conveyed materials are used, all of the three front nozzle units
2A, 2B, 2C are driven. When intermediate-sized conveyed materials are used, the two
adjacent front nozzle units 2A and 2B or the two adjacent front nozzle units 2B and
2C are driven. In addition, when the small-sized conveyed materials are used, only
the retaining conveyance unit 3A disposed corresponding to the center of the conveyed
material is driven. When the large-sized conveyed materials are used, all of the six
retaining conveyance units 3A to 3F are driven. When the intermediate-sized conveyed
materials are used, the adjacent retaining conveyance units 3A, 3B, 3D, and 3E or
the adjacent retaining conveyance units 3B, 3C, 3E, and 3F are driven. the adjacent
retaining conveyance units 3A, 3B, 3D, and 3E or the adjacent retaining conveyance
units 3B, 3C, 3E, and 3F are arranged at appropriate positions in the width direction
Y of the conveyed material during the conveyance of the intermediate-sized conveyed
materials.
[0083] In the above-described examples of Embodiment 1 and Variation 1, the plurality of
units including the front nozzle units 2A, 2B, and 2C and the six retaining conveyance
units 3A to 3F has a common configuration. However, in some embodiments, the plurality
of units may not have a common configuration.
[0084] According to Variation 1, the effects of Embodiment 1 described above can be obtained
with a configuration with a simple structure.
Embodiment 2
[0085] Next, a conveyed-material conveyance apparatus according to Embodiment 2 is described
below by focusing on differences from the conveyed-material conveyance apparatus 100
according to Embodiment 1. According to Embodiment 2, in the conveyed-material conveyance
apparatus 130 of FIG. 8A, the three front nozzle units 2A, 2B, and 2C and the six
retaining conveyance units 3A to 3F are not detachably attachable and have the following
configuration. For example, according to Embodiment 2, a conveyed-material conveyance
apparatus of Embodiment 2 is configured to allow separation and conveyance of a largest
size of the conveyed materials usable in the conveyed-material conveyance apparatus.
The front nozzle units 2A, 2B, and 2C and the six retaining conveyance units 3A to
3F are selectively driven and used according to the size of the conveyed materials
to be used.
[0086] With reference to FIG. 8A, for example, with all of the three front nozzle units
2A, 2B, and 2C attached, the front nozzle units 2A, 2B, and 2C may be selectively
driven and used according to the size of the conveyed material. For example, when
small-sized conveyed materials, for example, are used, only the front nozzle unit
2B disposed in the center of the conveyed material is driven. When large-sized conveyed
materials are used, all of the three front nozzle units 2A, 2B, 2C are driven. When
intermediate-sized conveyed materials are used, the two adjacent front nozzle units
2A and 2B or the two adjacent front nozzle units 2B and 2C are driven. The two front
nozzle units 2A and 2B, or 2B and 2C are arranged at appropriate positions in the
width direction Y of the conveyed material during the conveyance of the intermediate-sized
conveyed materials.
[0087] In addition, with all of the retaining conveyance units 3A to 3F attached, the retaining
conveyance units 3A to 3F may be selectively driven and used according to the size
of the conveyed material. For example, when the small-sized conveyed materials are
used, only the retaining conveyance unit 3A disposed corresponding to the center of
the conveyed material is driven. When the large-sized conveyed materials are used,
all of the six retaining conveyance units 3A to 3F are driven. When the intermediate-sized
conveyed materials are used, the adjacent retaining conveyance units 3A, 3B, 3D, and
3E or the adjacent retaining conveyance units 3B, 3C, 3E, and 3F are driven. Note
that the adjacent retaining conveyance units 3A, 3B, 3D, and 3E or the adjacent retaining
conveyance units 3B, 3C, 3E, and 3F are arranged at appropriate positions in the width
direction Y of the conveyed material during the conveyance of the intermediate-sized
conveyed materials.
[0088] In the above-described example of Embodiment 2, the plurality of units including
the front nozzle units 2A, 2B, and 2C and the six retaining conveyance units 3A to
3F has a common configuration. However, in some embodiments, the plurality of units
may not have a common configuration.
[0089] In Embodiment 2, the effects of Embodiment 1 mentioned above can also be achieved
with a simpler configuration.
[0090] Below, another embodiment differing from the above-described embodiment illustrated
in FIGS. 1 to 7 is described with reference to FIGS. 17 to 20. FIG. 17 is a front
view of a conveyed-material conveyance apparatus 230 including a conveyed-material
floating-retaining-conveying device 260 as the conveyed-material separation device
according to another embodiment of the present invention. FIG. 18 is a plan view of
the conveyed-material conveyance apparatus 230 of FIG. 17. FIGS. 19A to 19C are schematic
views of operational transition states of the conveyed-material conveyance apparatus
130. FIGS. 20A to 20C are schematic views of operational transition states of the
conveyed-material conveyance apparatus 130 following the state of FIG. 19C.
[0091] The embodiment illustrated in FIGS. 17 and 18 differs from the above-described embodiment
illustrated in FIGS. 1 to 4 in that the conveyed-material conveyance apparatus 230
is used in place of the conveyed-material conveyance apparatus 130. The conveyed-material
conveyance apparatus 230 includes the conveyed-material sensor 20, the conveyed-material
position controller to control driving of the elevation assembly to control the position
of the upper surface of the conveyed material bundle 1, and the front end guide plate
138, which are similar to, even if not the same as, those of the conveyed-material
conveyance apparatus 130 of FIGS. 1 to 4. The conveyed-material conveyance apparatus
230 includes, for example, the pair of side fences 137, the end fences 139, the side
air nozzles 370, and the side blower 380, which are similar to, even if not the same
as, those of the conveyed-material conveyance apparatus 130. Likewise, the conveyed-material
conveyance apparatus 230 includes the air chamber 320 and the air jetting nozzle device
300 including the floating nozzles 322, which are similar to, even if not the same
as, those of the conveyed-material conveyance apparatus 130.
[0092] The conveyed-material conveyance apparatus 230 illustrated in FIGS. 17 and 18 differs
from the conveyed-material conveyance apparatus 130 in that a conveyed-material floating
retaining conveyance device 260 is used in place of the conveyed-material floating-retaining-conveying
device 160 illustrated in FIGS. 1 to 4. The conveyed-material floating retaining conveyance
device 260 differs from the conveyed-material floating-retaining-conveying device
160 illustrated in FIGS. 1 to 4 in that an attraction roller 261 illustrated in FIGS.
17 and 18 is used in place of the conveyance belt 161. Below, a description is further
given of the configuration of the conveyed-material floating retaining conveyance
device 260 differing from the conveyed-material floating-retaining-conveying device
160.
[0093] As illustrated in FIGS. 17 and 18, the conveyed-material floating-retaining-conveying
device 260 includes the attraction roller 261, a negative-pressure air chamber 263,
a shutter 270, an air pipe 235 as a suction duct, and a suction fan 280 as a suction
air generator to generate suction air. Note that the suction air generator is not
limited to the suction fan 280 but may be, for example, an air compressor or any other
suitable type of suction air generator. The attraction roller 261 includes a shaft
261s rotatably supported on a body frame. The shaft 261s is coupled with a drive motor
268 as a drive device. The drive motor 268 drives the attraction roller 261 to rotate
in a direction to reel out a conveyed material. The shutter 270 is a valve to control
on-and-off of the flow of suction air, generated by driving of the suction fan 280,
from the negative-pressure air chamber 263 and the attraction roller 261 disposed
downstream from the shutter 270.
[0094] The attraction roller 261 is an attraction rotator of a roller shape having a plurality
of suction holes 264 in an outer circumferential portion thereof. The attraction roller
261 includes the negative-pressure air chamber 263. The negative-pressure air chamber
263 is communicated with the shutter 270 via the air pipe 235 and communicated with
and connected to the suction fan 280 via the air pipe 235. In the attraction roller
261, the suction holes 264 are disposed at upper positions opposite a front end portion
of the conveyed material bundle 1 stacked on the stack table 136. As described above,
the attraction roller 261 is communicated with the shutter 270 and connected to the
suction fan 280 via the air pipe 235 connected to the negative-pressure air chamber
263. In the attraction roller 261, air in the negative-pressure air chamber 263 is
sucked by the external suction fan 280 and the negative-pressure air chamber 263 is
maintained in a state of negative pressure. Accordingly, the uppermost conveyed material
1A is sucked and attracted through the suction holes 264 of the attraction roller
261.
[0095] As described above, the attraction roller 261 of the conveyed-material floating-retaining-conveying
device 260 functions as a retaining unit (retaining member) to attract and retain
a floated conveyed-material by a negative pressure generated by air suction to separate
the floated conveyed-material from other conveyed materials and a conveyor to convey
the retained conveyed-material. Note that the size of the conveyed-material floating-retaining-conveying
device 260 may be increased in accordance with the size of the conveyed material.
[0096] Next, an example of operation of the conveyed-material conveyance apparatus 230 including
the conveyed-material floating-retaining-conveying device 260 is described with reference
to FIGS. 19A t0 19C and 20A to 20C. When a conveyed-material feeding instruction is
received from a controller of the conveyed-material conveyance apparatus 230 of FIGS.
19A o 19C, the stack table 136 elevates up as indicated by arrow D1 in FIG. 19A and
stops at a predetermined position. The term "predetermined position" used herein represents
a position at which the conveyed material 1A at an uppermost surface of the conveyed
material bundle 1 stacked on the stack table 136 floats as described later and is
attractable by the attraction roller 261. At this time, the shutter 270 is closed.
Next, as illustrated in FIG. 19B, with the shutter 270 closed, floating air Aa is
blown from floating nozzles of the air chamber toward a front end face of the conveyed
material bundle 1 stacked on the stack table 136, and side air is blown from side
air nozzles. Such air floats up the conveyed material 1A, 1B, and 1C at an upper portion
of the conveyed material bundle 1 stacked on the stack table 136. Thus, the conveyed
material 1A at the uppermost face of the conveyed material bundle 1 floats up to a
position close to the height of the attraction roller 261 (the conveyed-material retainer).
Accordingly, the contact areas between the uppermost conveyed materials 1A, 1B, and
1C are changed by floating the uppermost conveyed materials 1A, 1B, and 1C prepared
on the stack table 136 (floating step).
[0097] By activating and operating the suction fan 280 with the shutter 270 closed, suction
air is generated, thus generating a negative pressure. Next, as illustrated in FIG.
19C, when the shutter 270 is open, the attraction roller 261 is turned into a state
of negative pressure and the conveyed material 1A at the uppermost face is attracted
and retained by the attraction roller 261 (retaining step). At this time, the uppermost
conveyed material 1A retained on the attraction roller 261 is not always separated
as a single sheet, but one or more conveyed materials may be in close contact with
the conveyed material 1A. Hence, the side air nozzles, which are disposed as the isolation
blowers on the side fences, blow the side air to isolate the conveyed material 1A
retained by the attraction roller 261 from other conveyed materials to be a single
sheet (isolation step).
[0098] Then, as illustrated in FIG. 20A, when the attraction roller 261 is driven to rotate
in a direction indicated by arrow D2 in FIG. 20A, the conveyed material 1A attracted
and separated is conveyed to a destination of conveyance downstream in the conveyance
direction X (conveyance step). A feeding sensor is disposed at a downstream side in
the conveyance direction X in the conveyed-material conveyance apparatus 230 to detect
the arrival of the conveyed material. When the feeding sensor determines that the
conveyed material 1A has arrived the destination of conveyance, as illustrated in
FIG. 20B, the shutter 270 is closed to turn the inside of the negative-pressure air
chamber 263 into the atmospheric pressure. When the conveyed material 1A passes out
from the attraction roller 261 after a predetermined time has passed, the rotational
conveyance driving of the attraction roller 261 is stopped (FIG. 20C). Note that,
when conveyed materials are continuously conveyed, the operation of FIG. 20A is continuously
performed.
[0099] The floating amount or the isolation state of the conveyed materials differs depending
on thickness, weight, or size of the stacked conveyed materials when the air volume
is fixed at a certain value. For example, if the floating amount of the conveyed materials
is small, no supply (no feed) of the conveyed materials occurs. In contrast, if the
conveyed material is floated exceedingly, the conveyed materials come in close contact
with each other to cause the multifeed. If the power of the suction fan 280 is small,
the conveyed materials cannot be conveyed successfully, and the no-supply also occurs.
[0100] To properly execute feeding of the conveyed materials, the air volume is previously
fixed according to the stacked conveyed materials, such that the fixed air volume
is reached automatically when the user or operator chooses the conveyed material to
be fed. The air volume is adjusted according to a duty ratio of the blower.
[0101] As described above, the conveyed-material conveyance apparatus 230 according to this
embodiment employing the attraction roller 261 and so on resolves the above-described
problem similar to that of the above-described embodiment and obtains the effects
equivalent to those of the above-described embodiment.
[0102] Similarly with the above-described Embodiments 1 and 2, in the conveyed-material
conveyance apparatus 230, the conveyed-material floating-retaining-conveying devices
160 is arranged as a plurality of units in the width direction or the conveyance direction
of the conveyed material, in accordance with the size of the conveyed material. The
positions of the plurality of units may be configured to be adjustable or detachably
attachable, thus obtaining effects equivalent to those of Embodiments 1 and 2. In
addition, the plurality of units may be configured to be selectively driven and used.
Further, the above-described configurations may be combined.
[0103] Although the preferred embodiments of the present invention have been described above,
it should be understood that the embodiments of the present invention are not limited
to the specific embodiments described above, and various variations and modifications
are included within the scope of the appended claims unless otherwise limited in the
present invention. For example, the embodiment of the present invention may be provided
by appropriately combining technical requirements described in the embodiments, the
variation, or the like. The embodiments of the present invention are not limited to
a case in which the conveyed material is a prepreg or a circuit board sheet including
an electronic circuit board material. The embodiments of the present invention are
also applicable to technical fields of a sheet separation device and a sheet conveyance
device to separate sheets of paper including very large-sized sheets of paper (e.g.,
having a width of about 700 mm), special paper, such as coated paper, or films for
the overhead projector (OHP) and so on.
[0104] The retaining conveyance units are not limited to the retaining conveyance units
3A to 3F of, e.g., Embodiment 1. For example, a plurality of conveyor belts of a common
configuration (or different configurations) not forming a step portion may be used
in place of the conveyance belts 161 a, 161b, and 161c forming the above-described
central step portion. For example, a plurality of (for example, three) conveyance
belts, which has the same configuration as the conveyance belt 161 of the conveyed-material
floating-retaining-conveying device 160 used in the above-described embodiment, may
be arranged side by side in the width direction of the conveyed material.
[0105] The effects and advantages recited in the above-described embodiments and variation
of the present invention are only examples of preferable effects and advantages obtained
from the present invention. The effects and advantages obtained from the present invention
are not limited to those of the above-described embodiments and variations.