Note: Descriptions are shown in the official language in which they were submitted.
_ _~.:
CA~02353482 2001-06-04
WO 00/34045 PCT/EP99/08685
T T : Apparatus for the alternative cleaning of two adjacent cylinders in a
printing
press, with a single cleaning device.
DESCRIPTION
The invention relates to reel- or sheet-fed rotary printing presses with
parallel cylinders which in the course of operation become wetted with ink and
fouled
with particles of paper and must therefore be cleaned periodically. Known
cleaning
devices for this purpose comprise, for example, a light alloy bar parallel to
the
cylinder to be cleaned. This is usually fixed and its face turned towards the
cylinder
to usually incorporates a longitudinal straight recess through which is guided
a presser
with a flexible elastic membrane close to the cylinder. The same bar contains
pneumatic actuators which on command press the presser against the cylinder so
as
to contact it with an interposed cloth on which washing fluids are sprayed by
nozzles
mounted in seats let into the face of the bar which is nearest the cloth. The
cleaning
15 cloth is unwound from a feed roller and its other end is connected to a
winding roller
and both these rollers, together with their means of rotation, are mounted on
parallel
shoulders supporting the said bar.
Also known are cleaning devices that differ from the above and
comprise a brush designed to contact the cylinder to be cleaned and sprinkled
by
2 o nozzles with the cleaning fluid.
In the remainder of the description the expression "cleaning device" will
be used to denote any device for cleaning the cylinders of a printing press,
even if
different from the devices indicated above.
In the prior art, each printing cylinder that has to be cleaned is normally
2 s provided with its own printing device. This solution is rather expensive
and reduces
the amount of space available for inspecting the cylinders of the printing
press. To
solve these problems, because the cylinders that are to be cleaned are often
close
together, for example the impression cylinder and the blanket cylinder, it is
also
known practice to use a single device for the alternative cleaning of one or
other of
3 o the two cylinders and for this purpose this device is mounted on suitable
drive
' systems. In some printing presses, such as those of the type produced by the
Japanese company Komori, there is a functional shaft running parallel between
the
1
SUBSTITUTE SHEET (RULE 26)
CA 02353482 2001-06-04
WO OOI34045 PCT/EP99/08685
two abovementioned cylinders which makes it impossible to use conventional
transfer systems for transferring the cleaning device from one roller to the
other.
The invention aims to solve this technical problem with an apparatus
for transferring the cleaning device which is technically reliable, of
moderate cost,
s and in which the cleaning device can be installed and removed quickly and
simply on
and off its supporting means. The device according to the invention can be
fitted
both to presses that do have this functional shaft between the cylinders that
are to
be cleaned, and to those presses which originally have no such functional
shaft and
which because of the presence of gripping clamps on one of the cylinders can
1 o usefully employ the present apparatus, which is characterized by among
other things
the fact that it can automatically prevent interferences between the cleaning
device
and the said clamps. The features of such an apparatus and the advantages
which
result therefrom will be clear from the following description of certain
preferred
embodiments, illustrated purely by way of non-restrictive examples, in the
figures of
15 the attached sheets of drawings, in which:
- Figs. 1, 2 and 3 illustrate the present apparatus in side view,
respectively in the position for cleaning the lower cylinder, in an
intermediate position
and in the position for cleaning the upper cylinder;
- Fig. 4 illustrates other details of the apparatus partly sectioned on
2 o IV-IV as marked in Figure 2;
- and Figs. 5, 6 and 7 illustrate variants of the apparatus, the first two in
side view and the last in perspective.
In the figures, C1 is the blanket cylinder, C2 the impression cylinder,
C3 the transfer cylinder and A is the functional shaft which in some machines
is
2 s situated parallel between the cylinders C1 and C2. The apparatus under
consideration pivots about the shaft A and, in a preferred embodiment, uses
this
shaft as a fulcrum. Mounted rotatably by their big ends on the ends of shaft A
are
mutually aligned connecting rods 3, 3', made for example from a suitable
material
with a low coefficient of friction, to which the ends of a steel half tube 1
is fixed
3 o coaxially with the same shaft A but not touching it, the only function of
the half tube
2
CA 02353482 2001-06-04
WO .00/34045 PCT/EP99/08685
being to connect the connecting rods structurally to each other, so that if
one of them
is pivoted, this pivoting is transmitted simultaneously to the other
connecting rod.
The rods 3, 3' may be made for example from a bronze alloy plate and they
comprise an arcuate head piece 2, 2' and a shank 102, 102' whose forked end
bears
s on the shaft A together with the said head piece 2, 2' and the ends of these
two parts
partially overlap and are fixed together and to the half tube 1 by means of
screws 4,
4'. The half tube 1 may for example be located on the same side as the head
pieces
of the rods 3, 3'. Hereinbelow, with reference to Figure 5, a variant will be
described
of the connecting rods and of their means of interconnection. 5, 5' indicate
the stop
Zo screws fixed perpendicularly to the outside flanks of the connecting rods
3, 3' and
acting on the shoulders S, S' of the printing press in order to ensure that
the
assembly 1, 3, 3' suffers no undesirable axial movements. Figures 1 and 4
illustrate
the cleaning device mounted on the present apparatus and, by way of example,
it
comprises a bar B that supports the presser P and that carries the complex of
15 nozzles for dispensing the washing fluid onto the cloth T which travels
around the
complex B, P, being unwound by suitable means from the roller R1 and wound
back
onto the roller R2. These rollers and the said bar B are all supported by the
shoulders F, F' which in tum are hinged to the little ends of the connecting
rods 3, 3'
by pins 6, 6', of which more later. It will be understood that any other
cleaning
2o device, wholly or partly different from that considered above, may be
mounted on the
shoulders F, F'. On the rear end of one of the shoulders F, F', for example
shoulder
F, is a protrusion 7 on the side of which is a wheel 8 which runs in a guide
channel 9:
the latter is roughly perpendicular to the shaft A and to the various surfaces
to be
cleaned, is approximately horizontal or suitably inclined and is formed in a
plate 10
2 s fixed by the distance pieces 110 to the nearest shoulder S of the printing
press. The
plate 10 may for example be at approximately the same height as the shaft A.
The
..
distance between the imaginary hinge axis formed by the pins 6, 6' and the
nearest
point on the circumference of the shaft A needs to be greater than the
distance
between the same imaginary axis and the adjacent upper and lower forward part
of
3 o the complex B, F, F' in order that this complex can when required rotate
about itself
3
CA 02353482 2001-06-04
WO QO/34045 PC'T/EP99/08685
and about its shaft A, while keeping its forward face always oriented towards
the
cylinders C1, C2 and without interfering with the said shaft {see later). In
Figure 4 it
can be seen for example that the pins 6, 6' can be moved axially within their
blind
seats 11, 11' which are formed in the complex F, F', B, B', together with
springs 12,
12' which push the pins outwards against the connecting rods 3, 3' where their
narrow ends 106, 106' pass into holes formed in the little end of these
connecting
rods 3, 3'. By pushing the pins 6, 6' into the seats 12, 12' with a pointed
tool, and
moving the cleaning device in such a way that the wheel 8 comes out of the
guide 9,
the cleaning device can be removed quickly from its supporting means. Whereas
the
1 o narrow end of pin 6 fits into a hole directly in the little end of the
connecting rod 3,
the end of pin 6' engages in the axial cavity of a screw 13 fastened to the
little end of
the rod 3', to the projecting portion of which is anchored the end of the rod
of a
double-acting primary jack 14 (operated by fluid pressure or
electromechanically),
whose body is attached to a pin 15 fixed to the adjacent shoulder S' of the
printing
15 press, for example approximately at the same height as the shaft A. It is
understood
that the axial mobility of the pins 6, 6' may be provided by a different
solution to that
described, e.g. by using screws for the pins.
The present apparatus is completed by a Lever 16 pivoting on a pin 17
fxed to the flank S of the printing press at approximately the same height as
the
2 o shaft A and beneath the plate 10. This lever points towards the shaft A
and on its
free end has a wheel 18 and is hinged at an intermediate point 19 to the rod
of a
small secondary double-acting jack 20 (operated in a similar way to the said
primary
jack) which is hinged by its body to a pin 21 fixed to the said shoulder S.
When the
jack 20 has its rod retracted as in Figure 2, the wheel 18 is on the outside
of the orbit
2 s which can be followed by a protrusion 103 that extends the connecting rod
3 beyond
its little end.
The operation of the apparatus as described is simple and obvious.
When the apparatus is in position to clean the lower cylinder C2, the
connecting rods
3, 3' are pointing down, the rod of the primary jack 14 is extended and the
bar B is a
3 o short distance from the cylinder C2, this last condition being ensured for
example by
4
CA 02353482 2001-06-04
WO 00/34045 PCT/EP99/08685
the force of the jack 14 and by the abutment of any part of the apparatus
against a
suitable stop means, for example by the abutment of the wheel 8 against a
blind end
109 of the guide 9 or by the abutment of the connecting rods 3, 3' against
end-of stroke stops (not illustrated). The actuators mounted on the bar B and
linked
s to the presser P, will provide the necessary interference between the cloth
T, pushed
by this presser, and the cylinder C2. To prevent interference between the
cleaning
cloth and any clamps Z on the cylinder C2, one side of the complex B, P is
provided
with a wheel 22 projecting the correct amount from the forward face of this
complex
and acted upon by cams of known type D fixed laterally with respect to the
area of
1 o the cylinder C2 where said clamps are situated, so as to retract the said
complex
sufficiently to automatically achieve the abovementioned condition of
non-interference.
When the apparatus is to be prepared for cleaning the cylinder C1, the
primary jack 14 is retracted as in Figure 2. The cleaning device rises and
15 simultaneously rotates about the shaft A and upon itself, about the axes 6,
6'. When
a~ sensor (not shown) detects that the jack 14 has reached the end of its
retraction
stroke, e.g. a magnetic sensor which detects the position of the piston of the
jack,
the rod of the secondary jack 20 is extended. This causes upward pivoting of
the
lever 16 with the wheel 18 which interferes with the protrusion 103 on the
connecting
2 o rod 3 and lifts the hinge axes 6, 6' of the apparatus above the point of
dead centre
which is defined by the previous withdrawal of the primary jack 14, which
latter at the
correct moment is extended to complete the raising of the cleaning device and
the
positioning of the bar B a short distance from the cylinder C1, as in Figure
3. After
performing its short lifting stroke, the secondary jack 20 can be retracted in
order to
25 return the wheel 18 to the down or rest position, or alternatively this
wheel can be left
in the up position, out of the orbit of interference with the protrusion 103
of the
,r
connecting rod 3 (see later). In this case, too, the cleaning device is
secured in the
correct position relative to the cylinder C1 to be cleaned, by the force of
the primary
jack 14 and by the abutment of any of the parts of the apparatus against
suitable
3 o stop means, e.g. by abutment of the wheel 8 against the blind end 109 of
the guide 9
CA 02353482 2001-06-04
WO 00/34045 PCT/EP99/08685
or by abutment of one of the connecting rods against a barrier (not shown).
When the apparatus is not being used andlor when the cleaning device
is in need of maintenance and must be removed, the apparatus is, for example,
in
the intermediate position shown in Figure 2 and safety means can be provided
to
s lock the apparatus mechanically in this position. Safety means may also be
provided
to lock the cleaning device mechanically adjacent to the cylinders that are to
be
cleaned, provided these have no gripping clamps or other irregularities on the
round
surface. The return of the apparatus to the down position for cleaning of the
cylinder
C2 may not require operation of the secondary jack 20, as the weight of the
complex
1 o B, P on the connecting rods 3, 3' should be sufficient to ensure that the
latter rods
have no difficulty getting past the dead centre, while the primary jack 14
moves
automatically from the refraction phase to the extension phase. It would be
understood, however, that should the weight of the apparatus be insufficient
to
overcome the friction of the fulcrums and hinges; so that gravity is unable to
move
i s the apparatus past the position shown in Figure 2, this job can be done by
the
secondary jack 20 which will be kept extended when the apparatus is in the
raised
position and will be retracted when the apparatus is in the position of Figure
2, so
that the wheel 8 interferes from the top down with the protrusion 103 of the
connecting rod 3 and pushes the complex below horizontal dead centre.
2 o Reference to Figure 5 will show that in a possible variant the
connecting rods 3, 3' may be identical and made of steel, with an internal
radius of
curvature of parts 2, 102, 2', 102' greater than the radius of the shaft A,
these parts
of the connecting rods being fitted with three rotatable wheels 23 whose axes
are
parallel to the said shaft A and that bear on this shaft to enable the
connecting rods
2 s to pivot with rolling friction. The same Figure 5 shows that the
connecting rods 3, 3'
may be connected in a different way by a pair of parallel beams 24, 24'
fastened to
the connecting rods by the pairs of screws 4, 4' which enable fastening
together of
the parts 2, 102, 2', 102' of which the rods are composed. In another variant
illustrated in Figure 5, the connecting rods 3, 3' are pivoted by means
different from
3 o the jacks 14, 20 discussed previously. A sector gear 25 is fixed to the
outside of one
6
CA 02353482 2001-06-04
WO 00/34045 PCT/EP99/08685
of the connecting rods and meshes tangentially with a rack 26 which is kept on
this
gear 25 by an idle wheel 27 and attached to the rod of a jack 28, which in tum
is
flanged to a support 29 fixed at 30 to a plate 10' attached to the adjacent
shoulder S
of the printing press. Means (not shown) are provided so that the jack 28 can
be
s actuated with an intermediate stroke which places the cleaning bar B in a
position
remote from both cylinders C1, C2, which is useful for various operations of
maintenance of the apparatus.
The apparatus according to the invention can also be fitted to printing
presses that do not have the functional shaft A discussed previously. In this
case the
to machine can be fitted with such a shaft A', preferably mounting it on the
shoulders S,
S' with intermediate supports 31 with bearings, as in Figure 7 and using
monolithic
connecting rods 3, 3' which are keyed to the shaft by means of a set screw 32
or by
other suitable means. Figure 6 illustrates another alternative construction in
which
the connecting rods can be keyed to a synchronizing shaft A', or can be hinged
at
15 one end to the shoulders of the press, as indicated for example at 33 in
Figure 6, in
such a way that the apparatus is able to rotate about an axis, parallel to the
rollers to
be cleaned, that is no longer physical as in the previous cases, but virtual.
In this
case use will be made of means for accurately synchronizing the pivoting of
the
connecting rods 3, 3', e.g. by using a synchronizing shaft 34 supported
rotatably by
2 o the connecting rods and fitted at its end with pinions 35 meshing with
sector gears
36, the latter being concentric with the axes of rotation 33 and fixed to the
shoulders
S, S' of the press. 37 denotes one of the connecting rod operating jacks. In
the
example shown in Figure 6, the shaft 34 is fixed to the flanks F, F' of the
cleaning
device and if the sector gears 36 have external teeth, as indicated in solid
lines,
2 s during the pivoting of the connecting rods the cleaning device rotates
with its working
face on the orbit 38, which is the opposite of the orbit followed in the
previous cases.
3
The cleaning device can rotate on the same orbit as in the previous cases, if
the
sector gears 36' have internal teeth as partly illustrated in broken lines in
the same
Figure 6. it is understood that the interconnection provided by the shaft 34
may be
3 o achieved otherwise by the frame F, F', B only of the cleaning device, as
this also is a
CA 02353482 2001-06-04
WO 00/34045 PCT/EP99/08685
rigid element.
It will be understood that the scope of the invention also encompasses
other ways of rotating the cleaning device about a virtual axis parallel to
the cylinders
to be cleaned, such as with the same cleaning device supported rotatably at
either
s end by carriages with wheels running on fixed arcuate guides whose centre of
curvature is on the said virtual axis.
s
