U.S. patent number 3,604,349 [Application Number 04/786,651] was granted by the patent office on 1971-09-14 for two-system moisture applicator for a lithographic press.
This patent grant is currently assigned to Addressograph Multigraph Corporation. Invention is credited to Ronald J. Garcowski, Arthur W. Sejeck.
United States Patent |
3,604,349 |
Sejeck , et al. |
September 14, 1971 |
**Please see images for:
( Certificate of Correction ) ** |
TWO-SYSTEM MOISTURE APPLICATOR FOR A LITHOGRAPHIC PRESS
Abstract
A two-system moisture applicator for masters on a lithographic
press. The first system rotates to contact the master, and is
retracted by lowering its pivot center to cause a cam and follower
to move the system away. The other system is conventional.
Inventors: |
Sejeck; Arthur W. (Kirkland,
OH), Garcowski; Ronald J. (Cleveland, OH) |
Assignee: |
Addressograph Multigraph
Corporation (Cleveland, OH)
|
Family
ID: |
25139219 |
Appl.
No.: |
04/786,651 |
Filed: |
December 24, 1968 |
Current U.S.
Class: |
101/148;
101/351.3 |
Current CPC
Class: |
B41F
7/26 (20130101); B41L 25/005 (20130101) |
Current International
Class: |
B41L
25/00 (20060101); B41F 7/26 (20060101); B41F
7/00 (20060101); B41f 007/40 () |
Field of
Search: |
;101/132.5,147,148,351,352,144 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Pulfrey; Robert E.
Assistant Examiner: Fisher; J. Reed
Claims
We claim:
1. In combination, a lithographic printing machine having a master
plate cylinder and a system for the sequential application of
different moisture treatment to said cylinder, comprising:
a frame, a first form roller carried by said frame, means to supply
moisture to said first form roller, and means for moving said frame
between a retracted position wherein said first form roller is
removed from said cylinder, and a service position wherein said
first form roller is in contact with said cylinder;
a subframe, a second form roller carried by said subframe, means to
supply moisture to said second form roller, said subframe having a
service position wherein said second form roller is in contact with
said cylinder, and a retracted position;
means for affecting movement of said subframe to place said second
form roller in said service position; and
means responsive to movement of said frame to said service position
for shifting said subframe to said retracted position.
2. The combination as defined in claim 8 wherein said frame and
subframe are articulated with a pivot interconnection between the
frames at a mean position, and the frames extending to
extremes;
a fixed position pivot connecting the extremes of said first frame
to said machine;
a guide cam track for said subframe carried in fixed relationship
to said machine and establishing a path divergent from said
cylinder;
means for moving said pivot interconnection between a first
position of maximum elevation with the angular relationship of the
frames placing the form roll of said subframe in said service
position, and a second position of greater angular relationship
with the subframe riding said cam track to said retracted
position.
3. The combination as defined in claim 1 in which there is also
provided;
a withdrawable support member coacting with the subframe for
preventing contact of its form roll with the cylinder when the
first angular relationship is first resumed; and
control means for withdrawing the support member to permit normal
contact of the subframe form roll with the cylinder when
desired.
4. The combination as defined by claim 1, wherein said means to
supply moisture to said second form roller comprises:
two sideplates of said subframe;
an intermediate roller carried on said side plates by bearings;
an upwardly opening bottom slot in each side plate, said form
roller having a shaft with end portions residing in said slots;
a downwardly opening top slot in each side plate;
an acceptor roller with shaft ends residing in said top slots;
resilient means urging said form roller and said acceptor roller
into said slots and into surface alignment with said intermediate
roller;
whereby, said system of the subframe is self-alignable to the
master cylinder and to one another when the subframe rests on the
cylinder gravity contact.
5. A master conversion system in combination with a lithographic
printing machine having a master cylinder, comprising:
a main frame having supply rolls with a form roll for rolling
contact with said master cylinder;
a pivot mounting for said main frame located a distance from said
form roll, said form roll on said frame swingable about said pivot
mounting between a first position retracted from said master
cylinder and a second position against said cylinder;
a subframe having supply rolls with a form roll for rolling contact
with said master cylinder;
said main frame and subframe articulated by a pivot interconnection
located a distance from said pivot mounting of said main frame,
said pivot interconnection is swingable through an arc
corresponding to that of said form roll of the main frame;
a diverting cam adjacent said subframe;
said subframe having a cam follower surface positioned to ride said
diverting cam, said subframe normally extending from the pivot
interconnection to a first position relative to said cylinder
wherein its form roll is in rolling contact with said cylinder when
the frames are held in a first angular relationship, and being
extendible to drive said cam follower along said cam to a second
position wherein its from roll is spaced from said cylinder as a
result of engaging said diverting cam and increasing the angular
relationship of said frames to drive the form roll of the subframe
farther from said pivot mounting.
6. In combination, a lithographic printing machine having a master
plate cylinder and a system for the sequential application of
different moisture treatment to said cylinder, comprising:
a frame, a first form roller carried by said frame, means to supply
moisture to said first form roller, and means for moving said frame
between a retracted position wherein said first form roller is
removed form said cylinder, and a service position wherein said
first form roller is in contact with said cylinder;
means for shifting the frame between at least one of said positions
and the other;
a subframe, a second form roller carried by said subframe, means to
supply moisture to said second form roller, said subframe having a
service position wherein said second form roller is in contact with
said cylinder, and a retracted position and being gravity urged to
said service position;
means powered solely by movement of said frame to said service
position for shifting said subframe to said retracted position;
means active when said frame is returned to its retracted position
normally to permit gravity return of said subframe to service
position; and
withdrawable support member preventing such gravity return of said
subframe to active position until said support means is withdrawn.
Description
BACKGROUND OF THE INVENTION
A lithographic printing plate, whether it be stone, metal or paper,
must present a background which rejects ink, and an image which
accepts ink. In modern office procedures, paper masters are
becoming predominant. Regardless of what type of master is being
employed, the background area must be prepared to reject the ink
and accept moisture. Background preparation is a chemical
conversion. Thereafter, the moisture used in the printing cycle,
although a chemical solution, serves the primary purpose of
supplying ink rejecting moisture.
The original procedure in preparation of a master was to convert
the surface by hand rubbing with a solution soaked pad while the
master lay flat on a support surface. Then, after the master was
installed upon the master cylinder of the machine, rollers kept a
constant supply of wetting solution applied to the master surface
in order that the background would be moist and the moisture in the
background would cause the ink from an ink roller to be
rejected.
In order to expedite the preparation of masters, U.S. Pat. No.
2,443,458 has taught a means for placing a dry master on the master
cylinder and applying the conversion and preparation liquid while
on the master cylinder. Operator's skill determined the length of
time that a saturated sponge was held against the surface of the
master, except for some versions of these machines which have
counting devices for producing a counted number of revolutions
before the application is stopped.
In the logical development of lithography for office procedures,
preprepared masters are stock-piled for the preparation of limited
supplies of regularly required forms and similar printed matter. A
stack of such preprepared dry masters is placed in mechanical
installation devices, which installs the masters on the master
cylinder in a dry condition and ejects the master after a counted
number of prints have been made from the master.
The present invention has freed the operator from the necessity of
attending the machine for the purpose of applying the preliminary
conversion and preparation solution after the master is
mechanically installed.
SUMMARY OF INVENTION
In a lithographic printing press having a master cylinder, and with
means for installing dry preprepared masters one-by-one, an
applicator scrubs the surface of the dry master on the cylinder
with a preparation liquid for an interval of time determined by a
timing circuit according to the requirements of master surface
preparation.
After the master is installed dry, and then wetted with the
preparatory solution for the required time, the preparation
apparatus is moved to an inoperative condition and a fountain
solution roller series is brought against the surface of the master
to supply repellent fountain solution during the actual printing
cycle.
The objects achieved by the invention will become more apparent as
the preferred embodiment of the invention is illustrated and
described hereafter.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of an embodiment of the invention,
showing only the moisture roller systems in phantom outline through
the side plate of the frame;
FIG. 2, on pg. 2 of the drawings, is a perspective view, with some
parts in exploded relationship, of a subframe with one moisture
roller system held therein;
FIG. 3 is an end elevation of the subframe and rollers of FIG. 2,
with a roller retention structure added, and the holding and
camming parts of FIG. 2 removed;
FIG. 4 is a front elevation, of one end of the roller system,
illustrating the roller retention structure of FIG. 3;
FIG. 5 is a diagrammatic arrangement of drive transmission gears
located on the end opposite FIG. 3, shown in exploded relationship
in FIG. 2;
FIG. 6 is a section taken along lines 6--6 of FIG. 5;
FIG. 7 on page 1 of the drawings is a side illustration, to an
enlarged scale, of the moisture system containing the subframe of
FIG. 3, with the electrically powered drive system restored, which
was omitted from FIG. 1;
FIGS. 8 and 9 are schematic illustrations of the moisture systems
movements during their operative cycle;
FIG. 10 is an electrical diagram of that portion of the control
system directly in control of the moisture system; and
FIG. 11 represents the control system for the entire machine,
including a variable resistor of FIG. 10.
DESCRIPTION OF PREFERRED EMBODIMENT
The principles of this invention may be applied to substantially
any lithographic printing device having a rotary master holding
cylinder. For this reason, the drawings have been restricted to
illustrating only the dual moisture applicating system of the
invention. A portion of a frame 10 is illustrated to represent a
lithographic machine of any design or construction which may be
desired. The illustrated preferred embodiment is in actual
commercial use on an Addressograph-Multigraph 1250 lithographic
press. The word "Multilith" and the number designation "1250" are
trademarks of the Addressograph-Multigraph Corporation, Cleveland,
Ohio, U.S.A.
A master cylinder 11 of conventional construction is represented by
a circular end view in FIG. 1. A frame 13, which consists of
laterally spaced, rigid iron castings crossed braced, provides
support for all of the moisture application rolls and fountains of
this invention.
A substantially conventional fountain solution system is provided
by a series of rollers culminating in a moisture form roll 14. The
series begins at a fountain 15 supplied by a storage bottle and
tube, which has not been illustrated in the drawings. This type of
fountain solution roll system is conventional and known. It
provides the constant supply of moisture needed to keep the
background of a master oleophobic. As printing progresses, the
sheets of paper will pick up the moisture from the master and this
moisture must be constantly replaced in order to prevent ink from
depositing in the background.
The frame 13 is pivoted about a pivot rod 17 in order that the
moisture form roll 14 may be caused to move into contact with the
surface of a master on the cylinder 11, or withdrawn therefrom
between printing cycles.
Frame 13 is held poised above cylinder 11 by springs, and must be
forced down to bring the moisture rollers into contact with the
master cylinder. A lever arm 19, carried by frame 13, is used as
the drive arm to cause the frame 13 to pivot about pivot 17. A cam
follower 20 carried by the arm 19 is driven by a rotary cam 21. Cam
21 is oscillated between the illustrated position wherein the frame
13 is elevated, and a position wherein the high peak of the cam 21
is against the follower 20. Contact of the cam high area with
follower 20 will force the frame down, to bring roller 14 in
contact with the cylinder surface.
The cam 21 is manually operable by means of a drive handle 22, but
is connected through conventional power systems to be driven in
proper sequence from a timing control system. The operator is able
ut use the handle 22 to test and adjust the apparatus, but during
the production use of the equipment, the oscillation of cam 21 is
accomplished by electronic control means operating through drive
devices.
The electrical control means and conventional drive devices are
eliminated from the drawings, these systems being known devices
well within the knowledge of the lithographic design and
maintenance engineer. However, a schematic diagram is provided in
FIG. 10 to indicate the use of a variable capacitor circuit used to
start and end the prewetting cycle.
The purpose of this invention is to enable the insertion and
printing from a plurality of dry masters by mechanical installation
devices, without operator attendance. Prior devices require an
operator to install one dry master and then force a sponge against
the surface of that master as it rotates on the cylinder. The
sponge is saturated with the required prewetting and conversion
solution necessary to prepare the master for use. The operator is
required to be in attendance at installation of every master. This
invention provides a device to take over that operation whenever a
loader device is used to install the masters in a sequence without
operator attention.
There are many and varied mechanical loading devices for installing
masters on master cylinders of duplicating machines. One example is
the Gammeter U.S. Pat. No. 3,420,169 issued Jan. 7, 1969. The
Gammeter patent illustrates the installation of a master that is
preconverted and therefore wet, although that device will work very
well on dry masters. Because the art of mechanical installation is
so very old and well known, it is believed that no further
illustration or teaching is necessary for instructing those skilled
in the art.
A subframe 29, shown separated from the frame 13 in the FIGS. 2
through 6, carries a series of moisture rollers. Subframe 29 is
supported on frame 13 by a pivot shaft 31, which also serves as a
source of driving power. The subframe has two lateral side plates
30 upon which the rollers are supported.
The subframe 29 supports a form roller 33 which actually contacts
the surface of the master on cylinder 11. A downwardly opening slot
34 in side plate 30 permits the axis shaft of roller 33 to move
relative to the subframe.
An intermediate roller 36 is mounted in plastic bushings which are
fixed in side plates 30. A third roll, designated an acceptor roll
and indicated by the character reference 39, is mounted in an
upwardly opening slot 40 of the side plates. The roll 39 is named
an acceptor to designate the fact that it accepts the moisture
which is transmitted through the train series of rollers to the
form roller 33.
The form roller 33 is positioned in the slot 34 without direct
retention by the side plate 30. A hook 42, as seen best in FIGS. 3
and 4, extends down to the shaft of roller 33 and holds it within
slot 34. Slots 37 in the hooks allow the hooks to span the shaft of
roller 36 and to move relative to the plates 30.
The roller 39 sits in the top position with its shaft projecting
into the slot 40 without direct retention by the subframe 30. A
clip 43 caps over the slot 40 and retains the roller 39.
A spring 44 interconnects the hook 42 and the clip 43 by connection
posts, as best seen in FIG. 4. The upward thrust thus produced on
roller 33, and the downward thrust upon the roller 39 causes the
two rollers to press together against the roller 36.
The subframe 29 is shown in a vertical position in FIG. 3. Its
operative position is suggested in the perspective FIG. 2, but
shown more accurately in FIG. 1. A hook 46 is mounted on the main
frame by guide members which fit through the two holes seen in the
hook 46, best shown in FIG. 2. The vertical position of the hook is
then established by the thumb screw at its top end. The hook fits
under the shaft extension of the intermediate roller 36 and
establishes a maximum distance that the subframe may descend in
actual use. Spring 44 is amply strong to pull the roller 33 up to
the roller 36. Master cylinders have slot openings to house master
clamps, but the form roller 33 will be supported by the spring and
will not have a tendency to drop into the slot.
A set of rollers 50 provide for fountain roll and metering
functions to bring up a film of moisture from a fountain and make
that moisture accessible to the acceptor roll 39.
In operation, the subframe 29 is moved to position the form roller
33 against the surface of a master on the cylinder and to position
the acceptor roller 39 in contact with the fountain roll system 50.
The speed of surface rotation of the form roller 33 is caused, by
reason of friction losses in the system, to be less than the
surface speed of the cylinder, but in the same direction. In this
manner, a gentle rubbing action is achieved to simulate the former
hand preparation of masters and to assure complete wetting of all
background surfaces.
Before a master is installed, the subframe 29 is blocked in an
operative condition by a pair of blocks 52 operating under each end
of the shaft of the intermediate roller 36. One of the blocks 52 is
seen best in FIG. 7, although in phantom outline. Only one block
will be referred to in the description hereafter. The physical form
of the block 52 is shown in FIG. 2 in exploded relationship to its
operative position.
A position arm 54 is interlocked with the block 52 by means of a
tongue and groove interconnection which permits relative rotational
movement about two opposed centers. Arm 54 is centered about a
shaft 56 which extends across the frame 13. Block 52 is pivoted on
center 57. Shaft 56 is also provided with a rocker arm 58 which is
spring loaded by a spring 59 urging the shaft in a clockwise
rotational direction. The spring therefore urges the position arm
54 to force the block 52 about center 57 toward a position under
the shaft of intermediate roller 36.
An electrical solenoid 61 connects through an arm 63 to rocker arm
58 for driving the shaft 56 and the position arm 54 against the
urge of spring 59. When the solenoid 61 is operated, the block 52
is driven to a nonblocking retracted position which allows the
subframe 29 and the three rollers carried thereby to fall
downwardly against the surface of the master cylinder to the
extreme position permitted by the hook 46.
Because the operative parts are many in number, and superposed in
front of one another, no one illustration in the drawings is
complete with all of the parts to which reference has been made.
FIG. 1 brings forth only the rollers 33, 36 and 39 and the hook 46.
FIG. 2 has eliminated all of the frame 13 and the various controls
normally associated with the operation of the subframe 29.
Likewise, in FIG. 7, the presence of the three rollers has been
subordinated and hook 46 eliminated.
Therefore, to better understand the operation of the manipulation
subframe 29, schematic sketches have been shown in FIGS. 8 and 9.
The block 52 is shown in full lines in FIG. 8 in its blocking
position, and both the positioning arm 54 and the block 52 are
shown in phantom outline in the position to which it is actuated by
the solenoid. The full line drawing of block 52 shows the surface
of the block in supporting contact under the full line position of
the shaft of intermediate roller 36. The phantom outline of the
shaft of intermediate roller 36 is shown in contact with the edge
of the block 52 in the downward position of the roller.
The movement of the set of rollers is exaggerated in all views. The
actual amount of movement is in the nature of the thickness of a
few sheets of paper, being sufficient to allow the form roller 33
to clear the surface of the master, and little more. Nevertheless,
the exaggerated illustration indicates that the block 52 will
permit the shaft of the intermediate roller 36 to drop and then the
block 52 cannot return under the urge of the spring 59 after the
solenoid 61 releases the drive force supplied. The spring is not
sufficiently strong to drive block 52 to actually elevate the
series of rollers and the subframe 29.
The entire operating cycle of the lithographic machine is
controlled in proper sequence by electrical circuitry and power
devices in the known manner, for example as shown in U.S. Pat. No.
3,056,346. By this invention; the hand operated plate-etch is
replaced by the sequentially timed applicator herein described.
The specific circuit is substantially self-evident from an
inspection of FIGS. 10 and 11. FIG. 11 is diagrammatic, and
represents the circuits to control such typical operations as
counting of printed output, ejection of spent masters, blanket
cleaning, and indicator signals. It includes a variable resistor
64.
In FIG. 10, a set of contacts C, of a relay operated by the circuit
control provides a momentary closed circuit across the illustrated
power lines. The closed circuit includes a rectifier, and a
resistor-condenser circuit, with resistor 64 as one element
thereof. This circuit serves the purpose of multiplying the time of
the effectiveness of the pulse through contacts C.sub.2 upon relay
R.
Relay R has contacts C.sub.2 in a separate circuit which includes
the solenoid 61. Therefore, when contacts C.sub.1 close, solenoid
61 is activated, and continues to operate until the
resistor-condenser circuit decays.
The decay of the circuit, to release relay R, then activates other
contacts, not shown, to rock the frame 13 and end the premoistening
cycle.
The timing of sequences is such that the form roller 33 is brought
into contact with the cylinder 11 prior to insertion of a new
master, in order that the cylinder surface will cause the tail end
of the master to adhere to the cylinder surface.
The form roller 33 will contact the cylinder and remain in contact
with the surface until physically elevated. During this period of
contact of the form roller 33 with the master, FIG. 8 indicates
that the acceptor roll 39 is in contact with the fountain roll 50.
Moisture is then supplied through a continuous train without
depletion.
After the electrical control circuit has determined a preselected
period of time, the cam 21 is actuated to bring the high portion of
the cam in contact with the cam follower 20 and force the frame 13
to pivot the form roller 14 down into contact with the master on
the cylinder 11. Such downward movement of the main frame 13 would
normally cause the form roller 33 to move around the surface of the
cylinder 11 without lifting. However, it is necessary when the form
roller 14 becomes active, to raise the form roller 33 to an
inactive condition.
For that purpose, a cam 65 is secured to the frame 10 under the
shaft of the intermediate roller 36. The shaft is not in contact
with the upper surface of cam 65 during the time the subframe is
blocked by the block 52, and although FIG. 9 shows the shaft
substantially in contact with the cam 65 in FIG. 9, there is
actually provided a very small clearance in order to avoid any
necessity for extreme precision in cam placement.
The cam 65 has an upwardly extending forward end portion 66, the
upper surface of which extends somewhat radially of the cylinder
11. Placement of this upwardly extending surface just under the
shaft of the intermediate roller 36 will cause the shaft of the
intermediate roller 36 to climb up that end surface 66 whenever the
frame 13 is lowered. Such upward climbing will move the subframe 29
away from the center of the cylinder 11 and thus force a separation
of the form roller 33 from the cylinder surface.
To make the movements more understandable, centerlines have been
included in FIGS. 8 and 9. In FIG. 8 the frame 13 is elevated and a
centerline is drawn between the main frame pivot 17 and the
subframe pivot 31. Whenever the solenoid 61 allows subframe 30 to
pivot downwardly, a slight movement takes place as shown by the
double centerline between the pivot 31 and the center of the shaft
on intermediate roller 36. The full lines indicate the neutral
condition, and the dotted lines indicate the active surface wetting
condition in FIG. 8.
In FIG. 9, the full lines indicate the position of the frame 13 and
the fountain solution series roller 14 in the lowered, active
condition. The dotted outline indicates the former retracted
condition. From a comparison of the angle X in FIG. 8 with the
angle Y in FIG. 9 it will be seen that the angle Y is larger,
indicating a flattening of the angle relationship between the two
frames, which results in forcing the shaft of roller 36 to climb
the cam end 66 and thereby lift the form roller 33 from the master
cylinder 11, and roll 39 from fountain rolls 50.
Then, having elevated the subframe 29 and the shaft of roller 36,
with respect to frame 13, the block 52 is able to move back into
blocking position as illustrated in FIG. 9.
Because the acceptor roll 39 moves out of contact with the fountain
rollers 50 during the inactive condition, separate power must be
supplied to the fountain rollers of assembly 50 if the surface
thereof is to be in constant preparation for supplying the moisture
when called upon. This invention also provides for this contingency
by the series of drives illustrated best in FIG. 5.
Because of space limitations, power from the main machine power
source is supplied to the pivot shaft 31 and through a gear train
culminating in a gear 68 connected to the shaft of intermediate
roller 36. The opposite end of roller 36 is then fitted with a gear
70 and the fountain roller is fitted with a driven gear 72.
Intermediate the gears 70 and 72, is a unique transmission gear
structure 74. See FIG. 6. Structure 74 comprises a hub 76 with an
elongated slot 78 in which a flattened end of shaft 80 resides.
Shaft 80 is a shaft for the acceptor roller 39. A rim gear 82 is
slidably fitted to the outside diameter of the hub 76 and is free
to drive independently of the hub 76. Therefore, drive from the
gear 70 is transmitted through the rim gear 82 to the fountain gear
72 without necessity of rotation of the acceptor roller 39.
Acceptor roller 39 is driven by surface contact with the
intermediate roller 36. The roller 39 is mounted in the subframe
39, and therefore pivots with that frame into-and-out-of contact
with the surface of the fountain roller, and maintains the straight
line relationship of the three roller shafts at all times. However,
the hub 76 is urged toward the fountain roller at all times by
means of a leaf spring 84 which is clipped under two pins 86
carried by the hub, and over the shaft 80.
The roller 39 will move away from the fountain, and will drive
continuously, and the fountain will also remain in constant drive
contact.
* * * * *