U.S. patent number 3,709,048 [Application Number 05/105,852] was granted by the patent office on 1973-01-09 for apparatus for mounting rollers in offset presses.
This patent grant is currently assigned to Adamovske Strojirny, narodni Podnik. Invention is credited to Josef Jurny, Karel Stepanek.
United States Patent |
3,709,048 |
Stepanek , et al. |
January 9, 1973 |
APPARATUS FOR MOUNTING ROLLERS IN OFFSET PRESSES
Abstract
Apparatus for mounting an ink roller so that it may be shifted
into engagement or disengagement with a form cylinder roller in an
offset press. The apparatus comprises a holder for journalling the
ink roller on a supporting frame, the holder being mounted so as to
be reciprocally movable on said frame along a path radial to the
axis of the form cylinder and an ink distributing roller to which
it engages. The holder and frame are provided with engaging bearing
means. A rod slideably extends through the holder parallel to the
radial path of movement and has stop means limiting the relative
upward and downward movement of the rod through said holder. Means
are provided for reciprocating the rod in response to the selected
operation of the machine whereby said holder can be listed and
swung to cause the ink roller to engage and disengage selectively
with the form cylinder and the ink distributor.
Inventors: |
Stepanek; Karel (Hlavni,
CS), Jurny; Josef (Hlavni, CS) |
Assignee: |
Adamovske Strojirny, narodni
Podnik (Adamor, CS)
|
Family
ID: |
5337716 |
Appl.
No.: |
05/105,852 |
Filed: |
January 12, 1971 |
Foreign Application Priority Data
Current U.S.
Class: |
74/53;
101/352.04 |
Current CPC
Class: |
B41F
31/301 (20130101); Y10T 74/1828 (20150115) |
Current International
Class: |
B41F
31/30 (20060101); B41F 31/00 (20060101); F16h
025/08 () |
Field of
Search: |
;74/53 ;101/352 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: O'Dea; William F.
Assistant Examiner: Ratliff, Jr.; Wesley S.
Claims
What is claimed:
1. Apparatus for mounting an inking roller with respect to a form
cylinder mounted for rotation about its central axis and an ink
distributing roller mounted parallel therewith comprising a
supporting frame, a holder mounted for reciprocal movement on said
frame along a path radial to the path of said form cylinder, said
roller being journalled in said holder for rotation about its axis
parallel to the axis to said cylindrical member, a surface inclined
to the radial direction formed on the exterior of said holder,
means mounted on said supporting frame and bearing against the
inclined surface, an elongated guide rod slideably extending
through said holder parallel to the radial path of said holder,
stop means limiting the relative reciprocable movement of said
guide rod through said holder, and means for reciprocating said
guide rod in response to a selected operation whereby said holder
is caused to selectively carry said roller into and out of
engagement with said form cylinder and said ink distributing
cylinder.
2. The apparatus according to claim 1 wherein said means for
reciprocating said rod comprises a cam moveable in response to the
selected operation of said machine, a cam follower, resilient means
urging said cam follower into contact with said cam, link means
interposed between said cam follower and said rod for connecting
said follower to said rod.
3. The apparatus according to claim 2 wherein said cam is provided
with a contoured profile adapted to cause said guide rod to move
said inking roller between a first position out of contact with
said ink distributing roller and said form cylinder, an
intermediate position whereby only said inking and ink distributor
rollers are in contact and a second position where said inking
roller is in contact with both said ink distributor roller and said
form cylinder.
4. The apparatus according to claim 1 wherein said stop means
comprises a collar secured to the end of said guide rod above said
holder and a compression spring located below said holder normally
urging said holder into resilient abutment with said collar, an
adjustable screw extending through said collar and bearing against
the end of said holder, a pin secured to the holder and extending
transversely through a vertical slot in said frame and adjustable
means for capping said pin through said slot thereby permitting
reciprocal movement of said pin in said slot.
5. The apparatus according to claim 1, wherein said means bearing
against said inclined surface comprises an adjustable screw member.
Description
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for mounting paired
rollers and, in particular, to apparatus for mounting the transfer
roller of and inking unit of an offset printing machine.
Offset printing machines provide a good example of the use of
paired rollers for the transfer of liquids such as ink from a
reservoir to the point of use. In such machines a combination of
ink-transfer rollers, distributing rollers, and form or printing
cylinders are employed. Apparatus is provided whereby the ink
transfer roller is shiftable into and out of engagement with either
or both of the distributing rollers and the printing cylinder to
provide constant pressure between the rollers and the cylinder to
effect the proper transfer of the ink. Generally, the transfer
roller engages the distributing roller simultaneously with the form
cylinder. When the operation of the press is interrupted for short
periods, the transfer roller must be disengaged from the form
cylinder in order to prevent an excess of ink from being applied to
the printing plate. When operation is interrupted for longer
periods, the transfer roller must be also disengaged from the
distributing roller as well so as to prevent deformation of the
roller caused by the static pressure between the rollers. The
apparatus must further be provided with a mechanism for maintaining
the constant pressure unchanged after repeated engagements and
disengagements of the roller.
It is the object of the present invention to provide an improved
apparatus for mounting paired rollers for movement or shifting
relative to each other.
It is an object of the present invention to provide in particular,
an offset printing machine or the like with an improved means for
mounting a transfer roller for more effective "tripping" action
with respect to the form cylinder and distributing roller.
It is another object of the present invention to provide shifting
and tripping apparatus for paired rollers in which the rollers are
moved relative to each other substantially along a radial path so
as to obtain a more effective and instantaneous disengagement.
It is another object of the present invention to provide apparatus
for movably mounting the transfer roller or the like of an offset
printing press for selective tripping action with respect to a form
cylinder in which the pressure between the roller and the cylinder
can be maintained unchanged even after successive engagements and
disengagements.
It is another object of the present invention to provide apparatus
of the type described which is simple in construction, more
economical to build, easier to use, and to maintain over a long
period of time than similar apparatus known in the prior art.
SUMMARY OF THE PRESENT INVENTION
According to the present invention, apparatus is provided for
mounting paired rollers in an offset press or the like, wherein
form cylinder is mounted for rotation about its axis. The apparatus
comprises a holder in which the ink roller is journalled for
rotation about an axis parallel to the axis of the form cylinder.
The holder has an inclined outer surface engaging a bearing member
secured to the frame. The holder is reciprocally movable on the
machine frame along a path radial to the axis of rotation. A rod is
provided which extends slideably through the holder parallel to the
radial path of movement and has stop means for limiting the
relative upward or downward movement through the holder. The rod is
provided with means by which it is reciprocally movable in response
to the selected operation of the machine whereby it causes the
holder to selectively move the ink roller journalled thereon into
and out of engagement with the form cylinder and the inking
distributor roll.
In the preferred form, the means for reciprocating the rod
comprises a cam having an arcuate cam face movable in response to
the selected operation of the machine. Engaging the cam is a
resiliently mounted cam follower which is linked to the reciprocal
rod so that rotation of the cam will effect reciprocation of the
rod. The cam is provided with a contoured profile adapted to cause
the rod to move between fixed positions defining the engagement or
disengagement of the rollers.
Preferably, the ink roller has associated therewith ink
distributing rollers, offset from the radial pair and located so as
to be engageable by the movable ink roller independently and by the
moveable ink roller in conjunction with the fixed roller. The
included surface on the holder forms a cam which is provided in
this situation with a contoured profile which affects this
selective operation in proper sequence. In this embodiment, the
apparatus is further provided with means for forcing the moveable
ink roller transverse to the path of movement so as to contact the
third roller under pressure.
The full details and a complete disclosure of the present invention
follow herein, referencebeing simultaneously made to the
accompanying drawings in which the preferred embodiments are
shown.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side elevational view partly in section from the
interior of the printing machine taken in the direction of P of
FIG. 2, and
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1.
Only so much of the conventional offset printing machine is shown
as is necessary for a full understanding of the present invention.
The offset printing press is, in general, the conventional type
such as that illustrated and described in "Photo-Offset
Fundamentals" by John E. Gogoli (McKnight and McKnight Publishing
Co., Bloomington, Ill., 1960, pages 158 et seq.,) and commercially
available as the "A.T.F. Chief Twenty Press". The actual printing
implements, and the complete set of roller mechanisms have been
omitted since they are not directly necessary for an understanding
of the present invention and will be obvious to all those skilled
in the present art.
The present drawings further illustrate only one end of the
assembly of an inking unit. It is understood that each of the
rollers, and form or printing cylinder, are symmetrically
constructed and have similar axle ends and mountings at each of its
ends. In according with the present invention, the mounting at both
ends are preferably the same in order to maintain the symmetry of
design and function and to equalize stress forces. They may,
however, be different if desired. Accordingly, it has been found
necessary to only show the apparatus at one end of the printing
press and thereby avoid unnecessary repetition and prolix.
Still further, the concept of the present invention may be applied
to the mounting to other paired engaging rollers and the fact that
the drawings and description disclose the mounting of an ink
transfer roller, a distributing roller, and a form cylinder should
not be taken as limiting in any way.
DESCRIPTION
Turning now to the drawings, the device as seen comprises an ink
transfer roller 10 adapted to cooperate in contact with both ink
distributing roller 12 and a form cylinder 14. The form cylinder 14
is journalled in suitable bearings to rotate about its longitudinal
axis and to be fixed in position with respect to the frame or other
supporting member F of the offset printing machine. The
distributing roller 12 may likewise be mounted for fixed rotation
about its axis parallel to the axis of the form cylinder. The form
cylinder and distributing roller are conventional in the art and
are provided with suitable drive means for their rotation. The
distributing roller may be mounted for oscillation along its axes.
As noted earlier, only one end of these elements are shown in the
drawings.
As seen in FIG. 2 the transfer roller 10 is also of conventional
design, having a neck-down portion 16 and an axle 18 which of
course extends from each end. The axle 18 is retained within a
supporting bearing assembly, generally depicted by the numeral 20
which is adapted to permit rotation of the transfer roller about
its axes and to carry and shift the roller into and out of
engagement with both the distributing roller independently and the
distributing roller and form cylinder simultaneously.
The bearing assembly 20 comprises an L shaped holder bracket 22
having formed in its horizontal or short leg a U-shaped pillow
block 24 in which a ball or roller bearing assembly 26 is secured.
The axle 18 extends through the center of the bearing 26 and is
rotatable therein in known manner. A cover plate 28 fastened by
screws 30 holds the bearing 26 in the pillow block 24. The long leg
of the L shaped bracket 22 is provided with a vertical bore 32
through which an elongated rod 34 slideably extends. The upper end
of the rod 34 is surrounded by a collar 36 which is secured to the
rod so that it abuts against the upper edge of the holder 22. The
lower end of the rod 34 is provided with a bifurcated pivot head 38
having a rectangular or squared upper shoulder edge. Surrounding
the rod 34 between the fork 28 and the lower edge of the holder is
a compression spring 40 of relatively strong rate which is adapted
to normally urge the holder bracket 22 upwardly into a firm seat
against the collar 36.
The bearing assembly is secured to the frame member F or another
supporting member of the machine by a shaft 42 which is secured to
and extends transversely from the upper end of the L shaped holder
22 through an enlarged vertical slot 44 formed in the frame. As
shaft 42 is capped by a nut and washer assembly 46 which fits over
the slot 44 and which permits the shaft 42 to reciprocate within
the slot while maintaining the holder 22 adjacent the frame
surface.
The rod 34 is arranged to extend along a path between the center C
of the form cylinder and the center O of the transfer roller and
will reciprocate in this path. The reciprocation of the rod 34 will
cause the holder 22 to carry the transfer roller 10 into and out of
engagement with the form cylinder also along this radial path. The
degree of pressure between transfer roller 10 and the form cylinder
14 in their engaging position is of course dependent upon the
extreme position of the holder 22 with respect to the rod 34.
Extending through the collar 36 of the holder 22 is a set screw 48
which abuts against the extreme end of the rod 34. The set screw is
adjustable to vary the relative position of the rod within the
holder and thus vary the degree of pressure exerted between the
transfer roller on the form cylinder.
As seen in FIG. 1 the holder 22 is provided with an inclined or
slanted fact 50 on the side opposite the distributing roller 12.
This incline provides the holder with a wedge shaped cam surface
having a high face at its lower end and a low face at its upper
end. Abutting against the face is a second adjustable set screw 52
within a bearing 54 mounted within the frame F. The set screw abuts
against the incline face 50 and provides a fixed camming surface
for the inclined face; thus, as the holder 20 is moved downwardly
by the action of the rod 34, the wedge shaped cam causes the
transfer roller to shift transversely to the path of movement of
the rod so as to cause it to engage with the distributing roller
12. As the holder 22 moves further downwardly the pressure causing
the transverse shift is somewhat relieved so that the transfer
roller 10 will contact the distributing roller with a predetermined
pressure and simultaneously contact the form cylinder 14. The
adjusting means for both the vertical movement and the swing
movement of the roller can be fixed and maintained in the fixed
adjusted position so that notwithstanding any number of engagements
and disengagements the exact pressure of the roller 10 on the
distributing roller 12 and the form cylinder 14 can be maintained
and will remain unchanged.
As noted, the reciprocation of the rod 34 causes the holder 22 to
reciprocate with respect to the frame F carrying with it the
transfer roller 10 which successively engages the distributing
roller 12 independently or the distributing roller 12 and the form
cylinder 14 simultaneously. The upward movement of the rod 34
reverses this operation again in a step-wise fashion so that
engagement between the transfer roller and the form cylinder can be
broken before the disengagement of the transfer roller and the
distributing roller. A feature of the present invention is the
provision of means for reciprocating the rod 34 and thus actuating
the movement of the holder and transfer roller. It will be
understood that the mechanism may, if desired, be placed on either
or both of the bearing assemblies of the transfer roller. It is
generally necessary, however, at only one end, and may be
automatically or manually operated in response to the operation of
the press to effect the selective reciprocation.
The mechanism for reciprocating the rod 34 comprises a two-armed
offset crank lever 56 pivotted at this center about a pin 58 which
is itself journalled in the frame F. The crank lever 56 has an
inner arm 60 extending upwardly toward and journalled in the forked
head end 38 of the rod 34 and an outer arm 62 extending offset
therefrom on the opposite side of the frame member F. Journalled on
the outer arm 62 is a cam follower 64 which is rotatable about a
retaining pin 66. Secured to the retaining pin 66 is a tension
spring 68 which is secured at its free end to the frame F of the
machine. The crank lever 56 is formed so that its arms extend in a
manner whereby the arcuate movement of the cam follower 64 will
reciprocate the rod 34. The spring 68 is adapted to have a spring
rate in excess of the rate of the compression spring 40 so that the
crank lever is normally biased inwardly. The cam follower 64 is
adapted to abut against an arcuate cam member (or circular cam) 70
which is fixed to rotate about a bushing 72 secured to an extension
of the axle 74 of the form cylinder. The bushing 72 or can 70 is
provided with conventional mechanisms as a motor, lever, pull rods,
or other devices whereby it may be rotated either automatically or
manually about the center of the shaft axle 74 at the proper time
and in the proper position during interruption or shut-down of the
printing press. Such means are not shown in detail in the present
description or drawings as they are conventional in nature and are
also believed to be well known to those skilled in this art.
The arcuate cam has a cam face 76 which is profiled in five
distinct stages I - V. As seen, state I comprises a notch or
indented surface of smaller diameter relative to the cam. Stage II
comprises an inclined portion rising from the lowest radius to a
plateau extending into stage III. Stage IV is another inclined
portion extending from the plateau of Stage III onto a surface
comprising stage V which has the longest or highest radius.
Stage V is of such a radius that it causes the crank 56 to move the
rod 34 radially inward toward the center C of the cylinder 14 so
that the transfer roller 10 presses against both the form cylinder
14 and the distributor roller 12. Stage III is of such radius that
the transfer roller is only pressed inwardly against the
distributing roller and is not engaged with the form cylinder.
Stage I, on the other hand, is of such shallow radius that the rod
34 is caused to extend its greatest distance upwardly so that the
transfer roller is neither pressed against the form cylinder nor
against the distributing roller.
In operation, when the printing press is in its initial position or
in its fully stand-still or inoperative position the cam 74 is
placed so that the follower 64 rests at stage I and in the shallow
indented portion of stage I. In this position, the crank lever 56
is caused to push the rod 34 to its extreme upward position,
disengaging the transfer roller from both the distributing roller
and the form cylinder. As the printing press is placed in
operation, the arm 74 is rotated counterclockwise (as seen in FIG.
2) so that the cam follower 64 rides successively up through stages
II, III, IV, and finally through stage V, thus causing the rod 34
to carry the holder 22 into sequential engagement first with the
distributing roller independently and then with the distributing
roller and the form cylinder simultaneously. The shifting or
tripping off of the transfer roller from the form cylinder is
effected by the reverse operation of the cam 74. Should only a
temporary interruption of the printing press take place, the cam is
only shifted from stage V to stage III where the cam follower
causes the upward movement of the rod 34 to a position where the
transfer roller is disengaged from the form cylinder but continues
to be engaged with the distributing roller. In this manner, the
distributing roller and the transfer foller can be continued to be
rotated so that the ink is evenly distributed and excess ink is
disposed of without application to the form cylinder. Should a more
permanent halt in the printing operation be desired, the cam is
then rotated to stage I where the action of the crank lever 56
causes the rod 34 to be fully elevated thereby moving the transfer
roller from engagement with the distributing roller itself.
The upward movement of the rod 34 causes the inclined surface 50 of
the holder to continue its engagement against the set screw 52,
thus maintaining the constant pressure of the transfer roller 10
against the distributing roller 12 even though the transfer roller
10 moves vertically away from the form cylinder. It will be noted
that the movement of the transfer roller 10 is substantially along
a path coincident with the radius of the form cylinder. This
arrangement insures that the rollers engage and disengage in
substantial point contact or in a line tangent to the circumference
of both the form cylinder and the transfer roller. This is of
particular importance during the disengagement of the roller since
a sharp, clean, and efficient break is effected reducing the
possibility of depositing of any excess ink on the form cylinder
and preventing any unnecessary rubbing or scraping against the form
cylinder.
The device thus described provides numerous advantages, amongst
which the fact that the ink transfer roller is as noted lifted
perpendicularly from the surface of the form cylinder. A further
advantage lies in the fact of selective tripping so that the
transfer roller can be disengaged from the form cylinder without
being disengaged from the distributing cylinder. Still a further
advantage lies in the fact that during the movement of the transfer
cylinder, the pressure between it and the distributing roller is
maintained constant due to the operation of the set screw 52 and
the circular configuration of the transfer and distributing
rollers. It will also be observed that the present device provides
a simple mechanism of very few parts both economical to produce and
to maintain. Since there is virtually no wear in any of the parts
of the bearing assembly, the device should have an extremely long
life.
A number of modifications have been suggested, and a number of
changes will be apparent to those skilled in the art. The present
description and drawing are intended to illustrate the invention
and not to limit it in any manner.
* * * * *