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1. * GB780013 (A)
Description: GB780013 (A) ? 1957-07-31
Improvements in or relating to means for applying printing ink to paper or
other material
Description of GB780013 (A)
PATENT SPECIFICATION
Inventor: ERNEST GrEO]RGE SMlITH Date of filing Complete
Specification: Aug. 5, 1954.
Application Date: Aug. 7, 1953.
No. 21942/53.
I/'4 Complete Specification Published: July 31, 1957.
Index at acceptance:-Class 100(2), C10(B1F: B3B: S).
International Classification:-B41f.
COMtPLETE SPIE!COIFICArION Improvements in or relating to means for
Applying Printing Ink to Paper or other Material (We, STRACHAN &
HENSHAW LIMITED, a Company organised according to the laws of Great
Britain.and Northern Ireland, of Whitehall, Bristol, 5, do hereby
declare the inven5,tion, for which we pray that a patent may be
granted to us, and the method by which it is to be performed, to be
particularly described in and by the following statement:-
This invention relates, to means for applying printing ink to paper or
other material, the object being to provide improvements therein.
One of the methods of applying printing ink to paper or other material
is to first apply 15;the ink to a first or inking roll of a rotary
printing machine, which said roll has depressions provided in its
surface, and then .,transfer the ink contained in, said depressions
direct, or by means of one or more intermediate rolls, from said
inking roll to a second or printing roll, the thickness of the film of
ink applied to the printing roll being conkrrolled or regulated by
scraping or otherwise removing ink from the surface of the inking roll
by means of a, doctor blade or like device, hereinafter referred to as
a doctor blade, whilst the inking roller rotates relatively to the
said blade so as to leave on the said roll the ink which is contained
in said depressions, the pressure of 'the blade on,the roll being

2. regulated in suitable manner. Thereafter the ink is transferred from
the printing roll to the paper or other material which is passed
around a third or impression roll.
Lit is known, from. specifications No. 217637/
07, No. 277,320 and No. 383,135, to provide the design roll of an
intaglio printing means with a doctor blade which is disposed with the
operative edge facing the direction from which the roll surface moves
towards the blade.
tAccording to this invention inking means for a rotary printing
machine for printing on paper or similar material, the said printing
machine comprising a printing roil having printing formes mounted
thereon, comprises an inking roll for applying a film of ink [PT M '
direct or by means of one or more initermediate rolls to said printing
roll, said inking roll having its surface provided with depressions
whereby printing ink applied to said surface. may be collected or
contained in said depressions, and a doctor blade for removing ink
from the surface of said inking roll, the doctor blade being disposed
at an angle of less than ninety degrees to a tangent of the inking
roll circumference in the direction in which the said roll rotates
away from the blade, that is, the operative edge of the blade faces
the direction from which the inking roll surface moves towards the
blade, said operative edge of the blade being in contact with the
surface of the inkig roll whereby the doctor blade removes all ink
from the surface of the inking roll except that ink which is contained
or collected in the said depressions.
One embodiment of the invention is illustrated in the accompanying
drawing, which is a transverse sectional elevation of the inking roll
and the associated doctor blade.
The inking roll 111 rotates in an ink trough 12 so as to pick up, on
the surface of the roll, a quantity of the ink contained in said
trough, the direction of rotation of the roll being indicated by the
arrow 13.. The roll 11 has a multiplicity of closely spaced
depressions, indicated diagrammatically at 14, provided over its
entire surface, which depressions are filled with- ink as they rise
out of the ink in the trough 12 during rotation of the roll..
A doctor blade!'5 is mounted on, one or more lever arms, of which one
is shown at 1l6, which are pivotally mounted at 1!7 in, a suitable
positfion on the printing machine frame, and, have spring pressure
applying means 118 associated therewith so that the blade 15. is
constantly urged into contact with the roll surface and any wear of
the blade edge is compensated to maintain the said contact.
For example, as illustrated in the drawing, the pressure applying
means 118 comprises la rod 19 pivotally connected at 20 to a lever
780,0 13 2 C8,1 arm 16, or to a longitudinal bar 21 whicl - connects

3. together the several lever arms I along the length of the roll 11, and
whic] rod 19 passes through a rail 22 fixed to thi machine frame. The
rod 19 is screw-threadec at its outer end at 23 and is engaged bl a
nut 24 having a milled edge 25 for hanc operation, the nut abutting
the outer face o:
the rail 22. A helical compression spring 26 surrounds the rod 19 and
abuts the inner face of the rail 22 and a collar 27 fixed to the rod
19. The spring 26 presses the doctoi blade 15, through the lever arm
16, into contact with the surface of the roll 11, but the extent of
movement of the blade towards the roll surface, under the urge of the
spring 26, is limited by the abutment of the nut 24 with the rail 22.
By adjusting the nut on the rod 19, the pressure of the blade 15
against the surface of the roll 11 may be adjusted; a lock nut 28
secures the nut 24 in its adjusted position on the rod 19. The spring
26 will allow the blade 115 to move resiliently away from the roll
surface if necessary, for example, in the event of any obstruction
occurring on the roll, or any other situation arising, which would
cause the blade to dig into the roll, thereby ensuring that no damage
is caused to the roll surface and/or the blade edge.
The doctor blade 15 is mounted rigidly in a blade carrier 29, being
clamped between plates 30, 31 which are rigidly, and adjustably,
secured to the carrier 29 by screw studs 32.
An adjusting screw 33, engaging the carrier 29 and the blade clamping
plate 30 enables the position of the blade on the carrier to be
adjusted, for example, for wear, when the studs 32 are slackened.
The doctor blade 15 is so disposed that the angle included by the
blade and a tangent of the roll surface at the point or line of
contact 34 of the edge of the blade with the surface of the roll, in
the direction in which the roll rotates away from the blade, is less
than ninety degrees.
The blade carrier 29 may be pivotally mounted at 35 on the blade
mounting unit, comprising the lever arm 16, and be locked in a
suitable relative position, so that the angle of the blade 15 in
relation to the inking roll 11 may be adjusted. The locking means
comprises bolts 36 which pass through the lever arm 16 and through
arcuate slots 37 in the carrier 29, which bolts are tightened, to
clamp the carrier 29 to the lever arm 16, when the required angle is
attained.
By arranging the doctor blade 15 in rela-tion to the inking roll 11 in
the manner according to this invention the blade acts in a skiving or
shearing manner on the ink, so as to totally remove ink from the roll
surface, and leave on the roll 11 only that ink which is contained in
the depressions 14.
The adjustment of the angle of the blade with the roll, and of the

4. pressure of the blade h on the roll, may be effected at a plurality of
6 positions disposed at intervals along the h length of the blade and
roll so that the blade e may be maintained under adequate control for
d maintaining close contact with the roll. 70 y The doctor blade may
be mounted in means Y at each end thereof for applying tension to the
f blade whereby it may be stretched so as to maintain a perfectly
straight edge for action against the roll. 75 The doctor blade 15 is
disposed so that the angle between the blade and the roll tangent is
within the range from zero to less than ninety degrees.
The inking roll 11 is of any suitable 80 material, and the depressions
14 are of any desired shape, area and depth, and arranged in any
suitable surface pattern. The depressions may have a depth of the
order of 0.0001 inch to 0.0050 inch, and preferably they are all 85 of
uniform depth, shape and area over the whole surface of the roll.
Ink may be supplied to the inking roll 11 in any suitable manner, for
example, as illustrated, the roll may run in a fountain, well 90 or
trough of ink so that surplus material removed from the roll by the
doctor blade may be returned direct to the said fountain or the like,
or the ink may be sprayed on to or othenvrwise supplied through
conduits to 95 the roll, or by a flooded roll running in contact with
it at the same or different surface speed, and the surplus ink may be
returned through conduits or ducts to a sump for recirculation. 100 By
doctoring the inking roll in accordance with this invention the ink is
skived or sheared from the roll and tends to flow in a streamlined
manner off the roll and from the doctor blade back to the return
means; thereby buildup of fluid pressure between the doctor blade and
the roll is substantially eliminated. Conversely, the deflection of
the ink away from the roll by the shear action of the blade creates a
slight pressure on the blade by the ink such as 110 to force the blade
against the roll; this pressure is likely to increase with the
increasing rotational speed of the roll and thus provide an automatic
ink film control. Any foreign matter on the roll which is caught up by
the doctor 115 blade will be removed completely from the roll and will
flowv away with the surplus ink.
The invention is for use in the application of ink to the printing
roll of a rotary printing machine, which printing roll has printing
120 formes mounted thereon, whilst the system may comprise other rolls
between, the inking and printing rolls for the purpose of adequately
taking up the ink from depressions in the inking roll and distributing
it in a film 125 of even thickness on to the printing roll.
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