Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE INVENTION
(0001] ROLLER PAD PRINTER
BACKGROUND OF THE INVENTION
(0002] The present invention relates to pad printers. More particularly,
the present invention relates to a roller or roll-on pad printing system.
(0003] Pad printing systems are used to apply high quality print, e.g.
indicia. Pad printing systems use a deformable pad which receives ink,
transferred as an
image, from a cliche plate. The plate has an etching or engraving of the
indicia formed
therein. The image is transferred from the pad to the item into which the
indicia is
applied.
(0004] There are two principal types of pad printers: standard pad printers
that use a flat printing plate cast called a cliche, and rotary pad printers
that use a drum
shaped cliche. In the standard pad printer, a flat cliche plate has the image
to be printed
etched into the plate. Ink is applied to (and wiped from) the cliche, and the
pad is
brought into contact with, e.g., pressed into, the cliche until the ink is
transferred onto the
pad. The pad is then brought into contact with the item to transfer the print
onto the item.
Both the inking motion (transferring ink from the cliche to' the pad) and the
printing
motion (transferring ink or decoration from the pad to the item) are linear
motions.
(0005] The rotary pad printer uses a drum-shaped cliche to present ink to a
synchronized, counter rotating cylindrical roller pad to transfer ink from the
cliche to the
pad roll. The roller pad is then moved across the item surface to transfer the
ink/decoration to the item.
(0006] While both of these methods function very well for printing or
decorating certain items or types of items, they do have their drawbacks. For
example,
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traditional (linear motion) pad printing is not effective when printing large
areas of ink or
when printing images that are very long.
[0007] The rotary printer is large and can be costly to manufacture and
operate, for example, to manufacture the rotating and counter rotating drum
arrangements
and the drum-shaped cliche. In addition, rotary printers operate using an
`open ink well',
which exposes the ink to atmosphere, resulting in more rapid viscosity change
due to
solvent evaporation, and increased opportunity for ink contamination.
Moreover, rotary
printers operate on a continuous basis, which is not always a cost effective
and efficient
manner of operation.
[0008] Accordingly, there is a need for a printing system that provides the
flexibility of a rotary printer with the ease of use and design of a
traditional linear motion
pad printer.
SUMMARY OF THE INVENTION
[0009] A roller pad printer is configured to print on an associated object
and includes a frame, a flat cliche operably mounted to the frame and a
resilient roller
pad operably mounted to the frame for rolling contact with the cliche.
[0010] The printer is especially useful for printing long or large areas on
the item or object to be printed. The roller pad engages the cliches at a
first location and
in a first direction along the cliche, to receive ink transferred from the
cliche. The roller
pad is adapted for rolling contact with the object, at a second location and
in a second
direction to transfer the ink from the roller pad to the object. In one
embodiment the first
and second directions are parallel to each other. The first and second
directions can,
however, be other than parallel to one another.
[0011] The printer includes an ink supply, preferably having an ink cup
with a wiper blade on the ink cup to wipe excess ink from the cliche.
[0012] In a present printer a carriage roll assembly is configured to
laterally move the roller pad between the first and second locations, between
the cliche
and the object and to maintain the orientation of the roller axis stationary
so that the first
and second directions are parallel. The assembly can also be configured to
rotate the
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roller axis to change the first and second direction so that they are not
parallel to one
another.
[00131 The printer can include a motor operably connected to the roller
pad to rotate the roller pad and control an angular position of the roller pad
relative to the
cliche or the object. Alternately the roller pad can be an idler roller. The
printer can be
configured as part of a robotic assembly.
[00141 A method of printing includes the steps of inking a flat cliche,
engaging a roller pad and the flat cliche against one another, moving linearly
in an inking
direction, at a first location, one or both of the roller pad and the cliche
relative to each
other to transfer at least a portion of the ink from the cliche to the roller
pad, moving the
roller pad transversely to the inking direction to a position for engaging the
object at the
area to be printed and moving linearly, in a printing direction, one or both
of the roller
pad and the object relative to the other to transfer at least a portion of the
ink from the
roller pad onto the object to be printed to print the area.
(0015) The method can include moving an ink cup over the cliche to
deposit ink on the cliche.
[00161 One present method includes the step of indexing the roller pad to
control an angular position of the roller pad relative to the cliche. The
position of the
roller pad can be monitored to control the location of the roller pad relative
to an etched
portion in the cliche and a location of the roller pad relative to the area to
be printed.
[00171 The roller pad can be returned to an initial position after transfer of
the at least a portion of the ink from the roller pad to the object.
[0017A] An aspect of the present invention provides for a roller pad printer
for printing on an associated object, including a frame; a flat cliche
operably mounted
to the frame, the cliche adapted to receive ink thereon; a resilient roller
pad operably
mount to the frame for rolling contact, at a first location and in a first
direction along
the cliche, to receive ink transferred from the cliche, the roller pad adapted
for rolling
contact with the object, at a second location and in a second direction to
transfer the ink
from the roller pad to the object. The first and second directions are
parallel to one
another. The first and second locations are different and spaced apart from
one another.
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[0017B] An embodiment of the present invention provides for the roller pad
printer includes an ink supply; a carriage roll assembly configured to
laterally move the
roller pad between the first and second locations, between the cliche and the
object and
a motor operably connected to the roller pad to rotate the roller pad and
control an
angular position of the roller pad relative to the cliche or the object. A
further
embodiment provides for the roller pad being an idler roller.
[0017C] Another aspect of the present invention provides for a device for
transferring print onto an associated object, including a frame; an arm
operably mounted
to the frame; a flat cliche operably mounted to the frame, the cliche adapted
to receive
ink thereon; a resilient roller pad operably mount to the arm and movable
relative to the
cliche for rolling contact, at a first location and in a first direction along
the cliche, to
receive ink transferred from the cliche, the roller pad adapted for rolling
contact with
the object, at a second location and in a second direction to transfer the ink
from the
roller pad to the object. The first and second directions are parallel to one
another. The
first and second locations are different and spaced apart from one another.
[0017D] An embodiment of the present invention provides for the device
for transferring print having an ink supply with an ink cup; a carriage roll
assembly
configured are part of the arm, the carriage roll assembly configured to
laterally move
the roller pad between the first and second locations, between the cliche and
the object;
a motor operably connected to the roller pad to rotate the roller pad and
control an
angular position of the roller pad relative to the cliche or the object.
[0017E] Another aspect of the present method for printing an area on an
object, the method includes the steps of: inking a flat cliche; engaging a
roller pad and
the flat cliche against one another; moving linearly in an inking direction,
at a first
location, at least one of the roller pad and the cliche relative to the other
such that at
least a portion of the ink is transferred from the cliche to the roller pad;
moving the
roller pad transversely to the inking direction to a position for engaging the
object at the
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area to be printed; moving linearly, in a printing direction, at least one of
the roller pad
and the object relative to the other, the printing direction being parallel to
the inking
direction; and transferring at least a portion of the ink from the roller pad
onto the object
to be printed to print the area.
[0017F] An embodiment of the present invention provides for the method
of printing including the steps of: moving an ink cup over the flat cliche to
deposit ink
on the cliche; indexing the roller pad to control an angular position of the
roller pad
relative to the flat cliche; monitoring the position-of the roller pad to
control the location
of the roller pad relative to an etched portion in the flat cliche and a
location of the
roller pad relative to the area to be printed; and including the step of
returning the roller
pad to an initial position after transfer of the at least a portion of the ink
from the roller
pad to the object.
[00181 These and other features and advantages of the present invention
will be readily apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The benefits and advantages of the present invention will become
more readily apparent to those of ordinary skill in the relevant art after
reviewing the
following detailed description and accompanying drawings, wherein:
[0020] FIG. 1 is a perspective view of the roller pad printer embodying
the principles of the present invention;
[0021] FIG. 2 is a perspective view of the roller pad printer;
[0022] FIG. 3 is a front view of the roller pad printer; and
[0023] FIG. 4 is a side view of the roller pad printer.
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DETAILED DESCRIPTION OF THE INVENTION
[0024] While the present invention is susceptible of embodiment in
various forms, there is shown in the drawings and will hereinafter be
described a
presently preferred embodiment with the understanding that the present
disclosure is to
be considered an exemplification of the invention and is not intended to limit
the
invention to the specific embodiment illustrated.
[0025] It should be understood that the title of this section of this
specification, namely, "Detailed Description Of The Invention", relates to a
requirement
of the United States Patent Office, and does not imply, nor should be inferred
to limit the
subject matter disclosed herein.
[0026] Referring now to the figures and briefly to FIGS. I and 2, there is
shown a roller pad printer 10 embodying the principles of the present
invention. The
printer 10 is configured to print high quality indicia onto relatively long
objects 0 or to
print large (and long) images onto objects O. The printer 10 includes a frame
12 onto
which the various components are mounted. A cliche 14 is flat and rests on a
platform 15
and a printing roller pad 16 is a cylindrical roll-type pad.
[0027] : In FIG. 3, the cliche 14 is fed from an ink supply 18. The ink is
supplied to the cliche 14 using apparatus and methods that will be recognized
by those
skilled in the art. In one known configuration, an ink cup 20 is conveyed over
the cliche
14 and ink is deposited into the etched regions in the cliche 14. Excess ink
is wiped from
the cliche 14, typically by a wiper blade 22 that is formed as part of or
integral with the
ink cup 20. Ink is supplied to the ink cup 20 by the ink supply system 18.
[0028] In FIG. 4, the ink is picked up from the cliche 14 and transferred
onto the roller pad 16, by compressiig the roller pad 16 and the cliche 14
against one
another and moving the two relativJ to one another. In a present printer 10,
the roller pad
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16 is carried on a carriage 24 (a carriage roll assembly) such that the
carriage 24 is moved
(as indicated by the arrow at 26), longitudinally along the cliche 14, or
rolled across the
flat cliche 14 to pick up ink or transfer ink onto the pad of the roller pad
16. It will be
appreciated that contact between and the relative motions of the roller pad 16
and the
cliche 14 must be carried out in a controlled manner so that the location of
the image
(ink) transferred onto the pad is accurately controlled for subsequent
transfer onto the
object 0.
[00291 The roller pad 16 can be a driven element. In such an
arrangement, the drive includes a motor 28 that rotates the roller pad 16 in
an indexed
manner so as to accurately control the angular position of the roller pad 16
relative to the
cliche 14. This type of arrangement can be used, for example, when printing on
"relief'
type raised surfaces that may have insufficient contact area with the roller
pad to
effectively rotate the roller pad during print operation. Alternately, the
roller pad 16 can
be non-driven roller (e.g., an idler roll), and can be rotated by friction
(between the roller
pad 16 and the cliche 14) and movement of the carriage 24 relative to the
stationary
cliche 14.
[00301 The carriage 24 is then moved transversely (as indicated by the
arrow at 30) from over the cliche 14 to a position over the item or object 0
to be
printed/decorated. In FIG. 3, the carriage 24 is shown in phantom in a second
position
for illustration only; those skilled in the art will appreciate there is only
one
carriage/roller 24/16 assembly in the machine 10 and which is slidably
movable.
[00311 The roller pad 16 is then brought into contact with the item 0 onto
which the ink or decoration is to be transferred, and the two are moved
relative to one
another. Again, in the present printer, the carriage 24 is moved relative to
the item 0
(also as indicated by the arrow at 26) and as such, the pad 17 of the roller
pad 16 is rolled
across the surface of the item 0, and the item 0 is decorated.
[00321 The present system 10 has been found to be advantageous when
printing large areas of ink (decoration) or when printing long decorations
onto relatively
flat items 0. The present system 10 allows for these printing scenarios by
using a novel
combination of traditional linear motion pad printers and the side-to-side
printing of
rotary pad printers. By using this novel hybrid arrangement, images can be
printed on an
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item from one side to the other side, across the item, rather than the center-
out
distribution of traditional pad printing.
[0033] Importantly, the present roller pad printer 10 allows the use of a
flat cliche 14 (akin to traditional pad printing techniques) and in some
instances, will
allow modification of traditional pad printers (e.g., printing machines) with
a roller pad
for more flexibility in the types and sizes of decorations that can be printed
and with
more flexibility in the types and sizes of items onto which printing can be
applied.
Moreover, the present pad printer 10 can be used to apply printing on a
smaller and/or a
batch basis rather than on a continuous basis, thus providing significantly
more flexibility
than known rotary printing systems.
[0034] Although the present roller pad 16 is described as being a driven
element, as discussed above, the roller pad can be a non-driven or idler
roller pad that is
rotated by the action of friction between the moving roller pad 16 and
relatively
stationary cliche 14 or item 0. In such an arrangement, it may be desirable to
monitor
the position of the roller pad 16 (angular as well as linear) to
determine/monitor/control
the location of the roller pad 16 relative to the decoration etched in the
cliche and/or the
location of the roller pad relative to the item. The illustrated printer 10 is
of the type that
uses a non-driven roller pad when printing, but is driven (by the motor 28) to
return the
roller pad to its initial position each time it is "reset" to begin a new
cycle. It has also
been found to be desirable to commence each inking and printing cycle with the
roller
pad 16 in the same angular position so that the ink pattern is transferred
onto the same
location on the roller pad 16.
[0035] It is also anticipated that printer 10 can be used to print cylindrical
or round parts, by using a motor driven pad roll, and/or motor driven part
fixture to rotate
the part under the pad and apply the image. This would be advantageous when
printing
low volumes of parts that do not justify a fully automated continuous motion
style rotary
pad printer, or when printing several different sizes and shapes of parts,
which are
difficult to accommodate in rotary pad printer part transfer systems, but
easily
accommodated with job specific tooling in traditional pad printing.
[0036] It will also be appreciated that although the present printer 10 is
described as a traditional printer, the printer, the is the printing function,
can be integrated
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with or within another device, such as a robotic system. For example, the
carriage 24 can
be integrated into the arm of a robot, and that such modifications, changes,
alterations
and the like are within the scope and spirit of the present printing system
and are to be
construed as such.
[00371 In the -disclosure, the words "a" or "an" are to be taken to include
both the singular and the plural. Conversely, any reference to plural items
shall, where
appropriate, include the singular.
[0038] From the foregoing it will be observed that numerous modification
and variations can be effectuated without departing from the true spirit and
scope of the
novel concepts of the present invention. It is to be understood that no
limitation with
respect to the specific embodiments illustrated is intended or should be
inferred. The
disclosure is intended to cover by the appended claims all such modifications
as fall
within the scope of the claims.
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