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Description  |
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FIELD OF THE INVENTION
The present invention is directed generally to a method and apparatus for
threading web materials and more particularly to a method and apparatus
for threading web materials in web-fed rotary printing presses. Most
specifically, the present invention is directed to a method and apparatus
for threading web materials in which the web's leading portion is secured
to a movable, finite length tape or strand which is, in turn, joined to
other similar webs or strands each of which is guided along a specific
path through the machine in which the web is to be fed.
The web threading or feeding apparatus of the present invention is
comprised generally of a plurality of finite length tapes or strands which
extend through the machine on suitable guides. Drive means are provided at
the ends and at intermediate portions of the tapes whereby each tape is
caused to move in the direction of web feeding during feeding of the web
and is then moved in the reverse direction back to a position ready to
feed a next web. Suitable junction means are provided along the tapes or
strands so that the course of web feed through the machine can be varied
as desired by joining together different conveyor tapes or strands.
Storage means at the ends of the web feeding path serve as receptacles for
the sections of conveyor.
DESCRIPTION OF THE PRIOR ART
Apparatus for threading web material into web-fed rotary printing presses
are generally well-known. For instance, infinite length, driven, flexible
tapes serve as conveyor means for web material. Also, motor carriages
running on rails have been disclosed, (German Patent Application No. 20 21
246). In the German published patent application No. 22 41 127 threading
of a paper web into a web-fed rotary printing press is described. In that
disclosure, a finite, driven, flexible, metallic threading element is used
and it must be guided throughout the press. The necessary guiding means
require a certain amount of space and the threading element must travel
over relatively large radii of curvature. Moreover, a multiple number of
synchronously running driving motors are required, if a long threading
element is used, with the number of driving motors depending on the length
of the threading element. To change the direction of motion of the
threading element, controllable branching-off devices are provided.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an apparatus for
threading web material preferably into web-fed rotary printing presses, in
which it is not necessary to guide the finite threading element in fixed,
through-passing guiding means, and in which no branching-off devices which
raise the price of the apparatus are required.
It is a further object of the present invention to provide a web threading
apparatus in which the feeding path of the web through the machine can be
varied.
Still another object of the present invention is to provide a web threading
apparatus in which the web is guided by a flexible tape or strand to which
it is secured.
According to the present invention there is provided a method and apparatus
for conveying a flexible web material attached to and guided by a
plurality of finite conveyor means fixed to the press frame, in which a
finite, flexible conveyor means is pulled from a first storage means by a
first pull-off device and is carried by a driving device to a second
storage means or device, and is carried back to the first storage device
after termination of the threading procedure.
The advantages obtainable due to the invention consist particularly in that
the threading of a web material around the smallest radii, through the
narrowest gaps and over long paths in an uncomplicated manner is made
possible. Thus, mechanical threading of a web becomes possible even with
the most difficult material web travels. As the threading apparatus
according to the invention requires only a small space, it can be used
even if only very small space is available. Furthermore, no mechanical
rails are required, only guide rollers or short guide pieces which can be
fixed at desired spaced points; therefore, the threading device needs
little mounting space or expenditure. In addition, the accessibility of
the web-fed rotary printing press is not reduced, when the threading
apparatus in accordance with the subject invention is used. The conveyor
means of the threading apparatus does not impede access to the press even
if it must be moved through narrow rooms entered by attending personnel
who have to, for example, mount or to adjust the inking rollers. For this
purpose the conveyor means can be removed.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the present invention are set forth with
particularity in the appended claims, a full and complete understanding of
the web threading method and apparatus of the present invention may be had
by referring to the description of a preferred embodiment as set forth
hereinafter and as is seen in the accompanying drawings in which:
FIG. 1 is a schematic side view of a web-fed rotary printing press in
accordance with the present invention and showing various web material
threading paths;
FIG. 2 is a detailed schematic diagram of two web material threading paths
and showing the storage devices and the parting positions;
FIG. 3 is a sectional drawing of a reeling or de-reeling device for a
conveyor means in accordance with the present invention, mounted in the
frame of a web-fed rotary printing press;
FIG. 4 is a plan view of a rope-shaped conveyor means with a fastening
device for web material;
FIG. 5 is a sectional drawing of a preferred embodiment of a driving
arrangement for a conveyor means in accordance with the present invention;
and
FIG. 6 is a schematic drawing of a second preferred embodiment of a
threading device in accordance with the present invention.
DESCRIPTION OF A PREFERRED EMBODIMENT
Turning now to FIGS. 1 and 2 it may be seen that the web threading or
feeding apparatus in accordance with the present invention operates
generally through the use of a number of flexible, finite length tapes or
strands which are connectable one to each other to form conveying means
for the web of material being fed through the machine. The tapes or
strands are stored in or on suitable storage means or devices such as
reels and the like and are removed from, or placed on those storage
devices in accordance with the direction of web feed. The various
individual tapes or strands are connectable one to the other in a
plurality of combinations to vary the path along which the web material is
fed. Suitable drive means are provided at either end of the conveying
means and additional drive means are positioned intermediate the ends.
As schematically shown in FIGS. 1 and 2, a finite conveyor means A3 moves
through the offset printing units 1 and 2. Each conveyor means A1 to A4,
or B, C, D, E, F, G, H, K, L begins in a storage device 3.1 to 3.4 or in a
fastening device 4.1 to 4.6 respectively and ends in a storage device 5.1
to 5.5 or in a fastening device 6.1 to 6.5, respectively. The storage
devices 3.1 to 3.4 and 5.1 to 5.5 may be structured as reels 7, as may be
seen in FIG. 3. Other modes of storage may of course be used. The storage
devices 3.1 to 3.4, 5.1 to 5.5 are driven by suitable driving means 8.1 to
8.4 and 9.1 to 9.5 as may be seen in FIGS. 1-3. For instance, first drive
means 8.1 to 8.4 and second drive means 9.1 to 9.5, used for carrying the
conveyor means into the storage devices, may be electric motors, hydraulic
motors, or pneumatic motors. These are mounted by means of a flange 10 in
the side frames 11 of the web-fed rotary printing press as may be seen in
FIG. 3. Advantageously receivers 12 for the reels 7 are designed as
so-called quick-change devices, so that the reels are capable of quickly
being changed or moved to another place.
In order to control the direction of movement of the conveyor means A1 to
A4, B, C, D, E, F, G, H, K, L, a plurality of guide rollers 13 or similar
means are provided. These are secured to the side frame 11 and are of
approximately 2 cm length.
During the procedure of threading the web material into the press, the
drive of the conveyor means A4, D, E, F, L is also accomplished by means
of a third or intermediate driving means 14.1 to 14.5, as may be seen in
FIG. 1. One or a plurality of pressure rollers 15 as may be seen in FIGS.
1 and 5 press the conveyor means, for example, a flexible, tape-shaped
conveyor means 16 as seen in FIG. 2, against the driving roller 14.6 to
14.10 of the intermediate drive means so that its positive conveyance is
secured. If a flexible, rope-shaped conveyor means 17 is used, it is
possible that one bend onto the driving roller 14.6 to 14.10 suffices for
ensuring a positive drive of the rope. Each driving roller 14.6 to 14.10
is synchronously driven with, for example, the feed rollers 18.1 to 18.5,
as may be seen in FIG. 2. The driven motion of the driving roller 14.6 to
14.10 can be imparted directly to it by the relative coordinated feed
rollers 18.1 to 18.5, or indirectly by a drive 18.6 rotating synchronously
with the feed roller 18.1 to 18.5, as shown in FIG. 5, or with the web-fed
rotary printing press.
Between each driving roller 14.6 to 14.10 and its relative drive such as a
feed roller 18.1 to 18.5, a coupling 19.1 to 19.5, as is shown in FIGS. 2
and 5, is inserted. This coupling is capable of being engaged and
disengaged, and its driving moment is adjustable. For this useage,
electromagnetic couplings are particularly suitable. Because of the
insertion of adjustable coupling 19.1 to 19.5, it is possible to preadjust
the maximum permissible pull exerted on the web material. Thus, breakage
of the material webs 20.1, 20.2, 20.3 or of the conveyor means A1 to A4,
B, C, D, E, F, G, H, K, L is avoided since the couplings 19.1 to 19.5 will
slip if a jam occurs.
The conveyor means A1 to A4, B, C, D, E, F, G, H, K, L, M are finite,
flexible tapes, ropes, chains, or similar material. They may consist of
natural fibres, synthetic material, metal, or of combinations of such
materials. The tape-shaped conveyor means 16 are, as may be seen in FIG.
2, equipped in the middle of their width, over their whole length, with
spaced slots 21 of approximately 100 mm length each. Into these slots 21
the leading end of the material web 20.1 to 20.3 can be introduced and
fastened therein. The rope-shaped or chain-shaped conveyor means 17, as
may be seen in FIG. 4, carries detachable or fixed material web fastening
devices 22. The leading end of the material web is fastened to them. They
may consist of plastic material or of metal.
The conveyor means A1 to A4, B, C, D, E, F, G, H, K, L may have one or a
plurality of parting positions, or joints 23.1 to 23.4 spaced over the
length of the conveyor means. These parting positions 23.1, 23.2, 23.3,
23.4 as are shown in FIGS. 1 and 2 permit parting the conveyor means, such
as A1+A3+A4 at these parting positions or joints into conveyor means
sections A1, A3, A4 to connect these individual sections with the conveyor
means of another web material threading travel, such as A1 with B, or A1
with D. The ends of the conveyor which are not coupled with another end of
a second conveyor are fastened to fastening devices 4.1 to 4.6, or to
storage devices 6.1 to 6.5, which are provided for this purpose, and thus
are secured out of the way.
The procedure for threading web material into the press is described with
reference to FIGS. 1 and 2 as follows:
The leading end of the material web 20.1, 20.3 and 20.3 on a supply reel
24.1, 24.2, 24.3 is tapered to form a tip capable of being fastened in one
of the slots 21 of the tape-shaped conveyor means 16 or in a material web
fastening device 22 of the rope-shaped conveyor means 17. In this phase of
operation the conveyor means and the printing press do not operate. By
means of convenient electric switching which initiates the threading
command, the desired ones of the couplings 19.1 to 19.5 are activated, so
that there is a through-drive from the feed roller 18.1 to 18.5 to the
driving roller 14.6 to 14.10 of the intermediate drive means 14.1 to 14.5
of the conveyor means A4, D, E, F, L as seen in the upper right portion of
FIGS. 1 and 2, it being remembered that the couplings 19.1 to 19.4 are
adjustable.
The first driving means 8.1 to 8.4 at the leading end and the second
driving means 9.1 to 9.5 at the rear end of the coupled conveyor means
A1+A3+A4, G+K+L, of each of the connected material web threading paths
such as AA, are maintained with a bias opposite to each other while at
rest so that the preselected conveyor means A1+A3+A4, G+K+L, is maintained
taut. When the web-fed rotary printing press is started and runs at the
speed reqired for the threading operation, the feed rollers 18.1 to 18.5
also rotate. If the coordinated couplings 19.1 to 19.5 are coupled, the
driving rollers 14.6 to 14.10 of the intermediate drive means 14.1 to
14.5, with the aid of the pressure rollers 15, so that the conveyor means
A1+A3+A4 are driving in a slip-free manner. In this phase of operation,
the first driving means 8.1 to 8.4 coupled with the supplying storage
device 3.1 to 3.4 does not exert any moment on the conveyor means
A1+A3+A4, G+K+L, whereas however the second driving means 9.1 to 9.5
coupled with the receiving storage device 5.1 to 5.5 is operated so as to
drive the storage device, which is a reel 7. Thus the conveyor means
A1+A3+A4, G+K+L, which is driven synchronously with the feed roll 18.1 to
18.5, is wound up on a reel 7 of storage device 5.1 to 5.5. By the motion
of the conveyor A1+A3+A4, G+K+L, along the preselected material web path
such as AA in FIG. 2, the material web fixed on it, for example, 20.1, is
conveyed along a predetermined path through the press. As soon as the top
of the material web has reached the desired position in the press, it is
removed from the slot 21 of the now stopped conveyor means A1+A3+A4, G+K+L
and is guided by hand for example over the formers of a folding apparatus.
When the leading end of the material web has been introduced into the
folder unit, the procedure of threading the material web into the press is
complete.
After every completed threading procedure, the conveyor means is re-reeled,
so that the required length of the conveyor means is available for another
threading procedure. By way of example, the re-reeling procedure can
automatically be initiated simultaneously with the first command "faster"
accelerating the press speed. This would mean for the described example
that the coupling 19.1 to 19.5 is deactuated and that the drive for the
driving roller 14.6 to 14.10 of the conveyor means A1+A3+A4, G+K+L is
stopped. At the same time, the first driving means 8.1, 8.4 will drive the
storage device 3.1, 3.4 so that the conveyor means A1+A3+A4, G+K+L is
re-reeled.
After termination of the re-reeling procedure the first and second driving
means 8.1 to 8.4 and 9.1 to 9.5 are maintained with a bias opposite to
each other while at rest so that the conveyor means A1+A3+A4, G+K+L are
maintained continuously taut.
For the termination of the reeling or re-reeling procedure, induction
switches can be used which may be, for example, actuated by a metallic
portion of the conveyor means. It is also possible to use disconnecting
devices which release an appropriate control command occasioned by the
decreasing or increasing reel radius of the reeled conveyor means. Any
number of alternate means may be employed to automatically stop the drive
means upon completion of web feed.
FIG. 2 shows two different material web paths AA and BB capable of being
realized by means of the conveyor means G, H, K, L. The conveyor means G,
H, K, L are guided by the guide rollers 13. The conveyor means G is
connected with the first storage device 3.4, and the conveyor means L with
the second storage device 5.5. The storage devices 3.4 and 5.5 are
drivably connected with the first and second driving means 8.4 and 9.5,
respectively, which are capable of being connected and disconnected as has
been discussed previously. The driving means 8.4 and 9.5 are fixed to the
side frames 11 of the web-fed rotary printing press. By way of example,
the feed roller 18.5 rotating synchronously with the number of revolutions
of the press, serves as a drive for the driving roller 14.10 of the
intermediate drive means 14.5 located in the side frames 11 of the web-fed
rotary printing press. A coupling 19.5 is interpositioned between the feed
roller 18.5 and the driving roller 14.10 and is capable of being connected
and disconnected. Pressure rollers 15 press the tape-shaped conveyor means
L against the driving roller 14.10. By way of example, suppose that the
material web is to be threaded along the material web path AA. To
accomplish this, the leading end 25 of the conveyor means K must be
fastened to the rear end 26 of the conveyor means G. The leading end 27 of
the conveyor means H which is set free, is, by way of example, fastened in
a depositing device such as fastening device 4.5. The rear end 28 of the
conveyor means L is then connected with the rear end 29 of the conveyor
means K. The rear end 30 of the conveyor means H is fastened, similarly to
its leading end 27, in a depositing device such as fastening device 6.4.
Fastening device 4.6 is provided for the leading end 25 of the conveyor
means K, and a fastening device 6.5 is provided for the rear end 29 of the
conveyor means K. The depositing devices, fastening devices 4.5, 4.6, 6.4,
6.5, are fixed at the side frames 11 of the printing press and provide for
maintaining the disengaged conveyor means taut. For this purpose, elements
which exert a tensile force, such as tension springs 31, can be fastened
at the leading ends or rear ends, respectively of the conveyor means which
temporarily are not being used, to tighten this conveyor means. The
leading ends of the conveyor means G, and the rear end of conveyor means
L, are fixed in the coordinated storage devices, 3.4 and 5.5.
For joining the tape-shaped conveyor means 16, different means can be used.
By way of example snap fasteners known from the textile industry can be
used. It would, however, also be possible to form the leading ends and the
rear ends of the tape-shaped conveyor means as loops, and to connect these
loops by means of appropriate connecting means.
In FIG. 5 there is shown an example of how an independent drive 18.6 of a
conveyor means A2 may be structured. As may be seen, a driving roller 14.6
cooperates with a pressure roller 15, with driving roller 14.6 being
driven from a drive 18.6 rotating synchronously with the press by means of
a toothed belt 40 which transfers a rotational motion onto the outer
stator 41 of a coupling such as an electromagnetic coupling. According to
whether the winding of the inner stator 42 is exited or not, a rotational
motion is transferred by means of the inner stator 42 by the shaft 43 onto
the driving roller 14.6 and thus onto the conveyor means A2. It goes
without saying that instead of the belt drive, other types of drives may
be used. The electric energy supply which is controlled, is provided by
means of the electrical connection shown schematically at 44.
Another embodiment of the invention is shown in the schematic drawing of
FIG. 6. A finite, tape-shaped, chain-shaped, or rope-shaped conveyor means
M, which is guided by rollers 13, is provided with fastening devices for
the leading end of a material web. Conveyor means M has its leading end 33
and its rear end 34 retained in storage devices 35 and 36 respectively,
which are not reel-shaped. Near the storage devices 35, 36, auxiliary
driving devices 37, 38 for the conveyor means M are disposed. They may
consist of a conveyor roller driven by a hydraulic motor, a pneumatic
motor, a rotary motor, or a linear motor and one or a plurality of
pressure rollers cooperating with the conveyor roller.
Between the driving devices 37 and 38, a main, intermediate driving means
39 for the conveyor means M can be positioned. It may consist of a driven
feed roller, an engageable and disengageable adjustable coupling, a
driving roller, and pressure rollers. The object and the mode of operation
of the auxiliary driving devices 37 and 38 are similar to those of the
driving means 8.1 to 8.4, and 9.1 to 9.5. The object and the mode of
operation of the individual elements of the main intermediate driving
means 39 correspond to those of the driving roller 14.6 to 14.10, of the
feed roller 18.1 to 18.5, of the coupling 19.1 to 19.5, and of the
pressure rollers 15 according to the example described above. The
explanations given in the first embodiment as to conveyor means, fastening
device, parting positions and principal modes of function, apply of course
also to this second embodiment.
While preferred embodiments of a method and apparatus for threading web
materials through a web-fed rotary printing press have been hereinabove
fully and completely described, it will be obvious to one of ordinary
skill in the art that a number of changes in, for example, the material
and for the conveyors, the type of drive motors used, the shape of the
guide means, the type of couplings between the conveyors, and the like
could be made without departing from the spirit of the invention and that
the scope of invention is to be determined by the appended claims.
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