U.S. patent application number 10/983716 was filed with the patent office on 2005-05-12 for noncontact web transporting apparatus.
Invention is credited to Nakayama, Mitsuyuki, Naruoka, Yasuhiko.
Application Number | 20050098680 10/983716 |
Document ID | / |
Family ID | 34544635 |
Filed Date | 2005-05-12 |
United States Patent
Application |
20050098680 |
Kind Code |
A1 |
Naruoka, Yasuhiko ; et
al. |
May 12, 2005 |
Noncontact web transporting apparatus
Abstract
A curved area is a jet surface for jetting the air from air jet
openings formed in a zigzag state. Two rollers are disposed in
parallel with a turn bar so as to be adjacent to both ends of the
jet surface in a transporting direction of a web. The roller
rotates, contacting with a surface opposite to a levitation surface
of the web, when the web is transported. Oscillation of the web is
prevented and the web is prevented from coming into contact with
the turn bar. Further, the air jetted from the jet surface is
prevented from leaking in the transporting direction. The air leaks
in a width direction of the web. An air pressure is prevented from
lowering at both ends of the jet surface so that a levitation
amount of the web becomes uniform.
Inventors: |
Naruoka, Yasuhiko;
(Shizuoka, JP) ; Nakayama, Mitsuyuki; (Shizuoka,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
34544635 |
Appl. No.: |
10/983716 |
Filed: |
November 9, 2004 |
Current U.S.
Class: |
242/615.12 |
Current CPC
Class: |
B65H 2701/1719 20130101;
B65H 29/52 20130101; B65H 23/24 20130101; B65H 2601/2532
20130101 |
Class at
Publication: |
242/615.12 |
International
Class: |
B65H 023/24 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2003 |
JP |
2003-381559 |
Claims
What is claimed is:
1. A noncontact web transporting apparatus for transporting a web
in a noncontact manner, said noncontact web transporting apparatus
comprising: a turn bar for levitating said web and altering a
transport direction thereof, said turn bar having a jet surface
formed with a plurality of jet openings from which gaseous matter
is jetted, and the gaseous matter jetted from said jet openings
being sprayed to a first surface of said web; and a pair of first
rollers disposed so as to be parallel with said turn bar, said
first rollers being adjacent to both ends of said jet surface
relative to the transport direction of said web to rotate, coming
into contact with a second surface of said web opposite to said
first surface.
2. A noncontact web transporting apparatus according to claim 1,
further comprising: a winding-angle changing mechanism for changing
a winding angle of said web of which said second surface is wound
on said roller, said winding-angle changing mechanism decreasing
said winding angle when said web has high rigidity.
3. A noncontact web transporting apparatus according to claim 2,
wherein said winding-angle changing mechanism comprising: a pair of
second rollers disposed at a passage of said web located below said
turn bar, said second rollers being also disposed so as to be
parallel with said turn bar to rotate, coming into contact with
said second surface of said web; and a shifting mechanism for
horizontally moving said second roller.
4. A noncontact web transporting apparatus according to claim 3,
wherein the pair of said second rollers are disposed at symmetrical
positions about said turn bar.
5. A noncontact web transporting apparatus according to claim 4,
wherein an interval of said second rollers is longer that an
interval of said first rollers.
6. A noncontact web transporting apparatus according to claim 5,
wherein said jet openings formed in the jet surface of said turn
bar are arranged in a zigzag state.
7. A noncontact web transporting apparatus according to claim 6,
wherein said jet surface has a U-shaped cross section in the
transport direction of said web.
8. A noncontact web transporting apparatus according to claim 7,
wherein said turn bar is provided with a duct for supplying said
gaseous matter to the inside thereof.
9. A noncontact web transporting apparatus according to claim 7,
wherein said gaseous matter is the air.
10. A noncontact web transporting apparatus according to claim 9,
wherein said web is a photosensitive printing plate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus for
transporting a web in a noncontact manner and in a stable
levitation state.
[0003] 2. Description of the Related Art
[0004] A web of aluminum and so forth is transported by rollers at
a line for producing a photosensitive printing plate (PS plate). At
this time, a slip and contact between the web and the roller are
likely to damage a web surface (coating surface of a photosensitive
layer), and a quality defect is likely to be caused. In order to
prevent the quality defect, it is necessary to transport the web in
a noncontact manner without contacting the web surface with a
roller surface. As to a noncontact transporting method, is
considered a method in which the air is jutted from a transport
surface of a turn bar to levitate the web. However, when this kind
of the turn bar is used to levitate and transport the web,
oscillation of the web causes flapping so that an air pressure
lowers near both ends of the transport surface of the turn bar, and
the web surface is likely to come into contact with the transport
surface. It is difficult to stably transport the web in the
non-contact manner and in a state that a levitation amount of the
web is uniformly kept.
[0005] As mentioned above, flapping is caused due to the
oscillation of the web near the ends of the transport surface of
the turn bar so that the web surface comes into contact with the
transport surface of the turn bar. Some methods for preventing the
contact are known (see Japanese Utility-Model Laid-Open Publication
Nos. 5-28632 and 6-6341, for instance). In this sort of the
methods, extra air is jetted from the ends of the transport surface
of the turn bar to prevent the air pressure from lowing thereat.
The levitation amount of the web becomes uniform and it is hardly
caused that the web surface comes into contact with the transport
surface of the turn bar due to the oscillation of the web.
[0006] However, the turn bars described in the above Publication
Nos. 5-28632 and 6-6341 need the extra air-amount for levitating
the web. In addition, there arises a problem in that the coat
increases since a structure of the turn bar becomes
complicated.
SUMMARY OF THE INVENTION
[0007] In view of the foregoing, it is a primary object of the
present invention to provide a noncontact web transporting
apparatus, at low cost, in which oscillation of a web is reduced
without complicating a structure of a turn bar to keep a levitation
amount of the web in a uniform state.
[0008] In order to achieve the above and other objects, the
noncontact web transporting apparatus according to the present
invention comprises a turn bar for levitating the web and altering
a transport direction thereof. The turn bar has a jet surface
formed with a plurality of jet openings from which gaseous matter
(including the air) is jetted. The gaseous matter jetted from the
jet openings is sprayed to a first surface of the web. The
noncontact web transporting apparatus further comprises a pair of
rollers, which are disposed in parallel with the turn bar so as to
be adjacent to both ends of the jet surface relative to the
transport direction of the web. The roller rotates, coming into
contact with a second surface of the web opposite to the first
surface.
[0009] In a preferred embodiment, a winding angle of the web of
which the second surface is wound on the roller is changed by a
winding-angle changing mechanism. When the web has high rigidity,
it is preferable to make the winding angle small.
[0010] According to the present invention, oscillation of the web
is reduced at both ends of the jet surface in the web transporting
direction so that flapping is prevented. Since the flapping is
prevented, the web is prevented from coming into contact with the
turn bar. In addition, the gaseous matter jetted from the jet
surface is prevented from leaking out of both ends of the jet
surface so that a gaseous-matter pressure is prevented from
lowering at these ends. Thus, the pressure of the jet surface is
uniformly kept so that a levitation amount of the web becomes
uniform and the web is stably transported in the noncontact manner.
Since the rollers are merely provided without changing a structure
of the turn bar, the noncontact web transporting apparatus may be
provide at low cost in comparison with a case using a turn bar in
which a jet amount of gaseous matter is increased at both sides of
the turn bar in the web transporting direction to prevent the web
from coming into contact with the turn bar.
[0011] By setting a gap, which exists between the roller and the
jet surface of the turn bar, so as to be minimum in consideration
of a thickness of a web joint portion, the gaseous matter is
prevented from leaking in the web transporting direction. Thus, it
is prevented that the web surface comes into contact with the jet
surface (transporting surface) of the turn bar due to a decline of
the gaseous-matter pressure. In addition, a wasted usage-amount of
the gaseous matter is reduced so that the web is efficiently
levitated.
[0012] Further, since the winding-angle changing member makes the
winding angle of the web small when the web has high rigidity, the
web surface is prevented from coming into contact with the
transporting surface of the turn bar.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above objects and advantages of the present invention
will become apparent from the following detailed description of the
preferred embodiments of the invention when read in conjunction
with the accompanying drawings, in which:
[0014] FIG. 1 is a schematic illustration showing a process for
producing a PS plate;
[0015] FIG. 2 is a perspective view showing a structure of a
noncontact web transporting apparatus;
[0016] FIG. 3 is a perspective view showing a structure of a turn
bar;
[0017] FIG. 4 is a schematic side view showing the structure of the
noncontact web transporting apparatus;
[0018] FIG. 5 is a schematic side view of the noncontact web
transporting apparatus of a case in that a winding angle is large;
and
[0019] FIG. 6 is a schematic side view showing a structure of a
conventional noncontact web transporting apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0020] An embodiment of the present invention is described below,
referring to the drawings. FIG. 1 is a schematic illustration
showing a PS-plate producing process. The PS-plate producing
process 10 is performed by a surface treating apparatus 13, a
washing apparatus 14, first and second coating apparatuses 15 and
16, and first and second drying apparatuses 17 and 18. A web 11
made of aluminum is advanced from a web roll 19, which is a source
of the web, by a web feeding apparatus 20. And then, the web 11 is
forwarded to the surface treating apparatus 13 by a plurality of
rollers 21. In the surface treating apparatus 13, surface treatment
is carried out in order to improve coatability and adhesion of a
photosensitive compound to be applied to a surface of the web 11.
The web 11 for which the surface treatment has been carried out is
cleaned by the washing apparatus 14. Successively, a photosensitive
coating liquid is applied to the web 11 by the first coating
apparatus 15.
[0021] The web 11 coated by the first coating apparatus 15 is
forwarded to the first drying apparatus 17 to dry a coating surface
thereof. A noncontact web transporting apparatus 22 is used for
transporting the web 11 from the first drying apparatus 17 to the
second coating apparatus 16. The noncontact web transporting
apparatus 22 comprises a turn bar 23 and four rollers 24a and 24b.
The turn bar 23 levitates the web 11 to transport it in a
noncontact manner. In virtue of this, the coating surface, which
has high adhesive properties even after drying, is dealt with in
the noncontact manner up to the second coating apparatus 16. A
coating liquid for a protector layer is applied to the web 11 in
the second coating apparatus 16. Successively, the web 11 is dried
in the second drying apparatus 18. And then, the web 11 is
transported by a plurality of rollers 25. After that, the web 11 is
taken up around a core 27 by a web take-up apparatus 26.
Incidentally, the present invention is not exclusive to the
embodiment shown in FIG. 1.
[0022] Next, a structure of the noncontact web transporting
apparatus 22 is described below with FIGS. 2, 3 and 4. FIG. 2 is a
perspective view showing the structure of the noncontact web
transporting apparatus 22. FIG. 3 is a perspective view showing a
structure of the turn bar 23. FIG. 4 is a schematic side view of
the noncontact web transporting apparatus 22. As described above,
the transporting apparatus 22 comprises the turn bar 23 and the
four rollers 24a and 24b. The turn bar 23 comprises a transporting
portion 35 having a substantially U-shaped cross section. The
transporting portion 35 constitutes a front side, a rear side and
an upper side of the turn bar 23. The turn bar 23 further comprises
two side walls 36, 37 and a bottom plate 38. The side walls 36 and
37 constitute lateral sides and cover both ends of the transporting
portion 35. The bottom plate 38 constitutes a lower side and covers
the bottom of the transporting portion 35. The inside of the turn
bar 23 is hollow. Incidentally, the web 11 is transported by the
transporting portion 35.
[0023] The transporting portion 35 comprises a curved area 35a
bending in an arc shape, and plane areas 35b extending from both
edges of the curved area 35a along a transporting direction of the
web. The curved area 35a is a jet surface for jetting the air to
levitate and transport the web 11. All over the curved area 35a,
air jet openings 39 having a same size are formed at predetermine
intervals in a zigzag state. In this embodiment, the interval of
the air jet openings 39 is 10.0 mm in the web transporting
direction, and the horizontal interval thereof is 10.5 mm. The
present invention, however, is not limited to the above-noted
intervals of the air jet openings 39 and the shape thereof.
Incidentally, regarding the air jet openings 39 shown in the
drawing, the size and the intervals thereof are magniloquently
illustrated for the purpose of avoiding complication.
[0024] The side walls 36 and 37 are respectively provided with air
ducts 40a and 40b through which the air is supplied into the turn
bar 23 by means of a blower or the kike, which is not shown. Thus,
an inner pressure of the turn bar 23 increases and becomes higher
than the outer pressure so that the air is jetted from the air
openings 39. In this way, the air is jetted from the jet openings
39 to levitate the web 11. The levitated web 11 is transported in
the noncontact manner by means of the turn bar 23. Incidentally,
the gaseous matter to be jetted from the turn bar 23 is not limited
to the air. The other gaseous matter may be used.
[0025] The two rollers 24a are disposed in parallel with the turn
bar 23 so as to be adjacent to both ends of the curved area 35a,
which is the air jet surface. The roller 24a rotates, coming into
contact with a surface opposite to the levitation surface of the
web 11. In virtue of this, oscillation of the web 11 is reduced at
both ends of the air jet surface so that flapping is prevented.
Thus, it is possible to prevent the surface of the web 11 from
coming into contact with the transporting surface of the turn bar
23. Further, by narrowing a gap d, as much as possible, between the
roller 24a and the transporting portion 35 (air jet surface) of the
turn bar 23, it is possible to prevent the air, which is jetted
from the curved area 35a of the turn bar 23, from leaking in the
transport direction of the web 11. Incidentally, in order to avoid
the contact of the surface of the web 11 and the transport surface
of the turn bar 23, it is preferable that the gap d is longer than
a maximum thickness of the web 11 by a prescribed amount.
[0026] The other two rollers 24b are disposed at a passage of the
web 11 located below the turn bar 23. The rollers 24b are disposed
in parallel to the turn bar 23 so as to be symmetrical relative to
the turn bar 23. An interval of the rollers 24b is adapted to be
longer than that of the rollers 24a.
[0027] As shown in FIG. 6, a conventional noncontact web
transporting apparatus 50 has two rollers 24b disposed below the
turn bar 23. However, a distance between the turn bar 23 and the
two rollers 24b is long so that the web 11 transported between them
can freely move. When the web 11 greatly oscillates at both sides
of the turn bar 23 (near an entrance side and an exit side thereof)
the web 11 is in danger of coming into contact with the turn bar
23. Moreover, large quantity of the air leaks in the transporting
direction of the web 11 so that a portion having an extremely small
amount of levitation occurs due to reduced pressure. Thus,
sometimes the surface of the web 11 contacts with the surface of
the turn bar 23.
[0028] However, as described above, the rollers 24a are adjacent to
both ends of the curved area 35a being as the air jet surface.
Further, the rollers 24a are disposed so as to be parallel with the
turn bar 23. Since the rollers 24a abut on the surface of the web
11 at both ends, movement of the web 11 is regulated. Thus, the
oscillation of the web 11 is prevented and the web 11 is prevented
from coming into contact with the turn bar 23. In addition, it is
prevented that the air leaks in the web transporting direction due
to the oscillation of the web 11. The air jetted from the air jet
openings 39 flows in a width direction of the web 11 such as shown
by arrows in the drawing. For making the jetted air contribute to
the levitation of the web 11, it is effective that the air flows in
the width direction of the web 11. The levitation amount of the web
11 becomes uniform relative to the transporting portion 35 so that
the web 11 is stably transported in the noncontact manner.
[0029] The web 11 is made of aluminum and has high rigidity. When a
winding angle of the web 11 is large at the rollers 24a disposed at
both ends of the air jet surface, there is a high possibility,
because of the rigidity, that the web 11 approaches the web
transporting surface of the turn bar 23 to come into contact
therewith. In view of this, as shown in FIG. 4, shifting mechanisms
42 are provided for the respective rollers 24b. The shifting
mechanism 42 horizontally moves the roller 24b in a right-and-left
direction to change the winding angle, which is the angle of the
web 11 wound on the roller 24a. Both of the rollers 24b are
horizontally moved by the shifting mechanisms 42 from a state in
that the winding angle is .theta.1 shown in FIG. 4. By lengthening
the interval of the rollers 24b, the winding angle becomes .theta.2
from .theta.1 such as shown in FIG. 5 so that the winding angle
increases (.theta.1<.theta.2).
[0030] In this way, it is possible to change the winding angle of
the web 11 relative to the roller 24a by means of the shifting
mechanism 42. When the web is made of aluminum and has high
rigidity, the smaller winding angle .theta.1 is set by the shifting
mechanism 42, such as shown in FIG. 4. In a case that the web is
made of a material having low rigidity, the larger winding angle
.theta.2 is set such as shown in FIG. 5. In virtue of this, it is
possible to reduce the winding angle of the web 11 relative to the
roller 24a when the web of the high-rigidity material is levitated
and transported. Thus, the web 11 is prevented from approaching the
transporting surface of the turn bar 23so that the surface of the
web 11 is prevented from coming into contact with the transporting
surface of the turn bar 23. By the way, in the case that the web
has low rigidity, the winding angle of the web relative to the
roller 24a is not restricted. In this case, the winding angle may
be properly adjusted by the shifting mechanism 42.
[0031] The shifting mechanism 42 horizontally moves the roller 24b
to change the winding angle of the web 11 relative to the roller
24a. However, this is not exclusive. For example, the roller 24b
may be vertically moved to change the winding angle. Alternatively,
the roller 24b may be swingably moved to change the winding
angle.
[0032] Next, an operation of the noncontact web transporting
apparatus 22 having the above structure is described below. As to
the actual PS plate, the web 11 has a maximum thickness of 0.5 mm.
When joining these webs 11 with a tape, the webs 11 are overlapped
and attached together with a two-sided tape, and then, an aluminum
evaporation tape is pasted around an outer circumference of the
joint portion for the purpose of reinforcement. As a result, a
thickness of the joint portion becomes about 2.0 mm. Meanwhile, the
levitation amount of the web 11 is about 2.0 mm. In consideration
of this, it is determined that the gap d between the surface of the
roller 24a and the transporting surface of the turn bar 23 (the
surface of the transporting portion 35) is about 4.0 mm. By doing
so, the web 11 is stably levitated and transported in a state that
the oscillation of the web 11 is minimized and the levitation
amount is prevented from decreasing at both ends of the curved area
35a, which is the air jet surface.
[0033] Ultimately, both of the rollers 24a are disposed in parallel
with the turn bar 23 such that the gap d is about 4.0 mm and the
rollers 24a are adjacent to both ends of the curved portion 35a
(air jet surface) of the turn bar 23 in the web transporting
direction.
[0034] The web 11 is transported by the noncontact web transporting
apparatus 22 along the passage formed by the rollers 24a, the
rollers 24b and the turn bar 23. At this time, the roller 24a
rotates, abutting on the surface of the web 11 opposite to the
levitation surface thereof. Owing to this, the oscillation of the
web 11 is prevented at each side of the turn bar 23 in the web
transporting direction (at the entrance side and the exit side of
the web 11) so that flapping is prevented. Thus, the web 11 is
prevented from coming into contact with the transporting surface of
the turn bar 23.
[0035] Meanwhile, the air jetted from the air jet surface is
prevented from leaking in the web transporting direction, and leaks
in the width direction of the turn bar 23 such as shown in FIG. 2.
Consequently, the air pressure is prevented from lowering at both
ends of the curved area 35a (air jet surface). Thus, the levitation
amount of the web 11 is uniformly kept relative to the transporting
portion 35 and the web 11 is stably levitated and transported
without coming into contact with the transporting surface of the
turn bar 23.
[0036] In the above embodiment, the noncontact web transporting
apparatus comprises the sole turn bar. However, this is not
exclusive. The noncontact web transporting apparatus may comprise a
plurality of turn bars. In this case, the two rollers may be
disposed every turn bar in parallel therewith so as to be adjacent
to both ends of the air jet surface of the turn bar in the web
transporting direction.
[0037] Moreover, in the above embodiment, the noncontact web
transporting apparatus 22 is disposed between the first coating
apparatus 15 and the second coating apparatus 16 to transport the
web 11 in the noncontact manner. However, this is not exclusive.
The present invention may be adopted to transport the web in the
other various apparatuses of the drying apparatus, the coating
apparatus and so forth.
[0038] Further, in the above embodiment, the PS plate is
transported in the noncontact manner. However, this is not
exclusive. The present invention may be applicable to continuous
strips having flexibility, for example, a photo-film base, a baryta
paper of a photographic paper, a recording-tape base, a videotape
base, a floppy-disk (registered trademark) base, and so forth.
[0039] Although the present invention has been fully described by
way of the preferred embodiments thereof with reference to the
accompanying drawings, various changes and modifications will be
apparent to those having skill in this field. Therefore, unless
otherwise these changes and modifications depart from the scope of
the present invention, they should be construed as included
therein.
* * * * *