Printing – Antismut device – Cleaners
Reexamination Certificate
2001-10-17
2004-01-13
Nguyen, Anthony H. (Department: 2854)
Printing
Antismut device
Cleaners
C101S425000
Reexamination Certificate
active
06675709
ABSTRACT:
DESCRIPTION
During the production and use of equipment for the automatic cleaning of inking rollers and rubber-coated cylinders of printing machines, described in Italian Patent No. 1,286,206 (or equivalent EP 0 916 492), it was found to be useful to make certain important modifications to improve the operation of the means of supplying the fluid mixture for cleaning the said rollers and cylinders, and in particular to provide a uniform distribution to the different supply holes of the said mixture formed from pressurized air and liquid, with small percentages of the liquid dispersed in the air which acts as the means of transport. For a clearer understanding of the objects of the invention, it will be useful to recall the prior art described in the patent cited above, with reference to
FIG. 1
of the attached drawings, which shows a cross section of the fluid mixture supply bar, and with reference to
FIGS. 2 and 2
a
which show, in a plan view from above and divided into two parts, with the division along the mid-line, the bar of
FIG. 1
with the channels which distribute the cleaning fluid mixture to the various supply nozzles of the bar. The equipment which is referred to (
FIG. 1
) comprises a bar
1
of light alloy, parallel to, and located at a short distance from, each rubber-coated cylinder
2
, and having on its side facing the cylinder a longitudinal rectilinear recess
3
in which a presser
4
with an elastic and yielding membrane
5
is guided. The said bar
1
houses the pneumatic actuators
6
which on command push the presser
4
,
5
against the cylinder
2
, to bring into contact with the cylinder the interposed cloth
7
on which a cleaning fluid has been previously sprayed by means of nozzles
9
mounted in one or more seats
8
formed in the said side of the bar which faces the cloth, these nozzles being connected, by means of holes
10
, to channels
1000
formed by milling in a flat side of the said bar, over which a flat seal
12
is subsequently extended and a cover plate
13
is fixed with screws
14
to convert the said channels into ducts. These channels are connected symmetrically to other supply channels branching from each other, which are bifurcated and progressively reduced in number, until they meet a single fluid mixture supply duct
100
, connected to an aperture
15
at one end of the bar
1
(see also
FIGS. 2
,
2
a
). Each bifurcation of the said channels is essentially Y-shaped and is formed as part of a rectilinear path, and the channels resulting from the bifurcation are structured in such a way as to offer an essentially equal resistance to the passage of the fluid mixture, so that this fluid is divided into essentially equal quantities in each bifurcation. The number of bifurcations is such that each final channel resulting from a bifurcation supplies a single nozzle, in such a way as to provide a balanced distribution of the cleaning fluid mixture between the various nozzles of the equipment.
FIGS. 2 and 2
a
also show that the aperture
15
communicates through the perpendicular hole
16
with a first channel
100
formed longitudinally in the bar
1
and that this channel is subjected, before the mid-line
18
of the bar, to a bifurcation B
1
which gives rise to two rectilinear and opposing ducts
101
,
201
which, before reaching the half-way point of each half bar, are subjected to respective bifurcations B
2
, B
3
which give rise to respective pairs of ducts, aligned with and identical to each other,
102
,
202
and
103
,
203
, which are then subjected to respective bifurcations B
4
,
85
and B
6
, B
7
which give rise to pairs of ducts
104
,
204
,
105
,
205
and
106
,
206
,
107
,
207
which then undergo respective and final bifurcations B
8
, B
9
, B
10
, B
11
and B
12
,
813
,
814
, B
15
which, by means of their respective channels
108
,
208
,
109
,
209
,
110
,
210
,
111
,
211
,
112
,
212
,
113
,
213
,
114
,
214
,
115
,
215
, supply the holes
10
to which respective nozzles
9
are connected. Each channel is followed by two initially rectilinear channels, which are located a short distance apart from each other, are parallel, and are equidistant from the upstream channel. The common dividing wall by which the channels resulting from each bifurcation are connected to the upstream channel is V-shaped in plan and has a sharp point. The two branches following each bifurcation open and proceed in opposite directions, one along an S-shaped path and one along a U-shaped path, as shown in the attached drawings. The number
26
indicates rectilinear milled grooves formed in the base of the channel
11
containing the cleaning liquid transport channels, blind threaded holes being formed in these milled grooves for interaction with the screws
14
for securing the cover assembly
12
,
13
which completes the said channels according to the prior art (FIG.
1
).
To balance the pressure drops, the channels resulting from each bifurcation are made with a suitable depth and width, as shown in FIG.
1
. For example, in the bar made by the applicant and illustrated in
FIGS. 2 and 2
a,
provided with sixteen supply nozzles, the initial channel
100
has a depth of approximately 10 mm and a width of approximately 5 mm, while the branches of the final bifurcations have a width of approximately 3 mm and a depth of approximately 2.5 mm. In the same bar, shown in
FIGS. 2 and 2
a,
the initial ducts have, for example, a width of 4 mm and a depth of 8 mm. After the first bifurcation, the width changes to 3 mm and the depth to 6 mm. After the next bifurcation, the depth remains constant and the width decreases to 2 mm. The final bifurcation has branches 2.5 mm deep and this depth and the width of 2 mm remain unchanged up to the end.
In the bar in question, the cleaning liquid is injected in a low proportion in a flow of pressurized air which has the function of transporting the liquid and by means of which the liquid is supplied to the aperture
15
of the bar.
FIGS. 2 and 2
a
clearly show that the cleaning fluid mixture transport circuit has many curves. The low concentration of the cleaning fluid in the transporting air flow has the effect of making the mixture of air and liquid tend to break up and lose its homogeneity during its passage around each curve of the said circuit, as a result of the centrifugal force, gravity, and especially the contact with the walls of the ducts, on which the liquid tends to be deposited.
At the exit from each curve of the mixture transport duct, it is possible for the quantity of liquid deposited on one lateral wall of the duct to be very different from that deposited on the opposite lateral wall. If the rectilinear duct which follows the curve has a limited length, the mixture of air and liquid cannot be re-compacted and made uniform before it reaches the next bifurcation, and therefore the division of the mixture into the two channels of the said bifurcation may take place incorrectly, in the sense that more liquid than air, or vice versa, may reach one channel.
This disadvantage can be particularly marked in the final bifurcations of the circuit shown in
FIGS. 2
,
2
a,
for example those indicated by B
9
, B
10
and B
13
, B
14
, since the cross section of the channels of the circuit decreases progressively towards the end, for example down to the aforesaid value of 2×2.5 mm. Although the progressive reduction of the section of the channels enables the mixture to be concentrated towards the centre of the channels so that it can be branched in equal portions in the next bifurcations, it also introduces considerable pressure drops into the circuit, and these progressively limit the quantity of air reaching the nozzles, with a negative effect on the desired uniformity of spraying of the mixture by all the nozzles of the bar.
To this disadvantage must be added the fact that the limited cross section of the final channels of the circuit can be decreased incidentally by the deformation of the elastomeric seal
12
, under the pressure of the plate
13
, in these channe
Corti Marco
Fumagalli Riccardo
Larson & Taylor PLC
Nguyen Anthony H.
LandOfFree
Bar for supplying fluid detergent mixture in equipment for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bar for supplying fluid detergent mixture in equipment for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bar for supplying fluid detergent mixture in equipment for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3232574