Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CAP PRINTER AND METHOD FOR
SILK SCREEN PRINTING ONTO THE
FRONT PANEL OF A CAP
This invention relates to cap printers
which use a silk screen for transferriny a design to
the front panel of a cap.
Logos and various designs have been applied
to the front panel of caps for many years. The
original way oE applying these logos or designs was
by making a patch and then sewing the patch to the
front of the cap. This process, however, proved to
be quite time consuming and expensive and has been
substantially replaced by two methods presently in
use.
One of these methods involves a heat
transfer process~ With this process, the printer
generally orders appliques which are manufactured
with the chosen design. In a few instances, a
printer may have sufficient machinery himself to
produce the appliques but this is generally not the
case. Once the printer receives the appliques, he
heat-seals them to the front panel of the caps.
Drawbacks of this process include the time and cost
required to have the appliques produced, usually by
another company, and the fact that after a certain
period of time, the appliques crack and peelO In
addition, when smaller follow-up orders are received
by the printer, it is generally not worth the cost
of re-ordering extra appliques to Eill these orders.
For these reasons, a number of printers have begun
using the process commonly known as silk-screen
printing.
With silk-screen printing the printer first
- stretches the silk-screen or man-made mono-~ilament
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over a frame. To assure that there is no distortion
when printing, the tension must be the same on all
parts of the screen. A photograph is then taken of
the chosen design and the im~age from this photograph
is transferred onto the silk screen by a process
well known in the art. After the image has been
transferred onto the screen, an ink i9 spread over
the entire screen. When the ink dries, it seals the
silk screen except in those areas now containing the
image. In order to print the design, one simply
applies the screen to the material being printed on
and with a squeegee runs some ink over the back of
the screen. The ink travels through those portions
of the screen which have not been sealed thereby
transferring the design to the material. When the
printing is completed, the frame is removed and
stored in case of future orders. Thus, most
printers have a large inventory of mounted silk
screens which can be reused for filling follow-up
orders.
Several of the advantages of silk screen
printing include the speed with which a silk screen
can be prepared generally by the printer himself,
and the fact that the screen is always available for
follow-up orders. Also, by usin~ silk screens,
printers have successfully avoided the difficulties
of having the design crack or peel. For these
reasons, the use of silk screen printing has been
widely accepted. However, when applied to the
printing of caps, a number of difficulties have been
encounterecl which have prevented cap printers from
takinq full advantage of the silk screen process.
Some of the difficulties unique to cap printing
include trying to print onto a normally rounded
surface ancl mounting all the caps in the same
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position so that the caps and the silk screen are
properly aligned thereby avoiding crooked or off-
centered impressions. This alignment i9 commonly
referred to as registration.
When one prints onto the rounded front
panel of a cap using a flat silk screen, a distorted
impression is obtained. This is due to the fact
that the pressure between the screen and the
material being printed upon will vary with more
pressure being applied at the top of the curve of
the cap~ This variation causes differences in the
spreading of the ink as it passes through the silk
screen and thereby causes distortion of the design
applied to the cap.
In an attempt to overcome this shortcoming,
two approaches have been used. The first uses a
curved silk screen which matches the curvature of
the cap being printed upon. The second approach
uses a flat printing surface and attempts to flatten
the curved front panel of the cap. Neither of these
approaches have been successfuIly implemented and
thereforer there was still a need for an accurate
and clear printing silk screen cap printer. It was
in light of this situation that development of the
invention first began.
During the initial steps of development,
experiments were done with curved silk screens.
However, use of a curved silk screen proved to be
both impractical and expensive. The first
difficulty of working with a curved frame involved
the stretching of the silk screen over the frame.
Due to the curvature, it was more difficult to
obtain an equal tension throughout the screen. A
variance in this tension would lead to a distorted
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image when the printed ink was passed through the
screen.
The curved frames were also found to be
significantly more expensive than the flat ones
which are used by most printers. Due to the higher
cost of the curved frame, it was impractical to
store the silk screens in their mounted positions
and therefore the screens had to be removed from the
frames. Once the screen was removed from the frame
and the tension was released, the screen woulcl
return to its normal size. When the screens were
reframed, it was necessary to stretch them to the
same degree that they had been stretched initially.
When the silk screen was not reframed with the same
degree of tension, the image produced was distorted.
One other difficulty involved matching the
curvature of the frame and its associated silk
screen to the cap being printed upon. In those
situations where the curvature of the screen did not
match the curvature of the cap, distortions would
occur similar to those described above when a flat
screen was applied to a rounded surface. Due to the
numerous difficulties in dealing with a curved silk
screen, efforts were turned to the development of a
silk screen printer which utilized a flat printing
surface.
In the area of silk screen printers which
utilized flat printing surÇaces, the prior art had
been unable to sufficiently flatten the front panel
of the cap and anchor the cap so that it would not
move during printing. In order to flatten the
normally curved front panel of the cap, a certain
amount of tension needs to be applied to the cap
especially across the front panel. Those inventions
which failecl to provide for such tension found that
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the cap would move when the silk screen was applied
and the front panel would often wrinkle. Those
devices which did apply tension to the front panel
of the cap did not apply the tension evenly. This
caused distortions for two reasons. First, when the
cap was removed from the printer, the stretched
portions would return to their normal size. Those
areas which were under greater tension would
contract to a greater degree thereby producing
unacceptable distortions in the design. Secondly,
the variation in tension often caused creases along
the front panel which prevented even printing. In
addition, when mounting the caps on the prior
devices it could not be determined whether or not
the caps were being mounted in the same position
each time. Therefore, the design was not
transferred onto the same portion of the front panel
of each cap.
In the development of the present invention
it was sought to provide a printer capable of
blocking a cap during printing. For the purposes of
this application~ "blocking" refers to the providing
of interior supports at specific areas within the
cap to avoid the creasing which would interfere with
25 ~ the flatness of the front panel of the cap being
printed upon. This blocking alos serves to maintain
the cap in proper alignment during printing.
According to the invention it is possible
to provide a cap printer which maintains the front
panel of the cap flat so that there are parallel
printing surfaces; each cap, when mounted has the
same aligned relationship with the silk screen; any
tension applied to the printing surface is applied
evenly across the entire surface; the cap is secured
to avoid movement during printing; and the design
being transferred will not be distorted and the
design will be centered in the same position on each
cap.
Briefly described, the present invention
has a saddle upon which the cap is mounted. The
saddle has a flat printing surface over which the
front panel of the cap is placed. A registration
plate is mounted in a spaced-apart perpendicular
relationship to the printing plate so as to define a
channel between them into which the sweatband of the
cap can be inserted. This relationship provides for
the same registration of each cap since the
registration plate serves to center the cap upon the
saddle thereby assuring that the design is applied
to the same part of the cap each time a cap is
printed. In order to prevent the cap from creasing
along the front panel, and to secure the cap during
printing, the saddle is designed to support various
portions of the interior of the cap thereby blocking
the cap. A silk screen and frame attached to the
printing device moves between an advanced and a
retracted position such that the advanced position
puts the screen in parallel contact with the front
panel of the cap and the retracted position provides
sufficient room for the cap to be removed from the
saddle.
Also briefly described, the present
invention includes a method for silk screen printing
which involves mounting the cap on the saddle so
3~ that the cap is blocked. The cap i5 pOS i tioned so
that the bill presses against the registration plate
which is positioned in a spaced-apart perpendicular
relationship to the flat printing surface. When the
cap is pulled from the rear, the front panel is
stretched across the printing plate thereby
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flattening it during the application of the silk
screen. When applying this process, the sweatband
of the cap resides in the space between the printing
plate and the registration plate.
Fig. 1 is a rear perspective view of the
invention.
Fig. 2 is a side elevational view of the
invention.
~ig. 3 is a side elevational view of the
invention showing a cap mounted upon the saddle and
a silk screen applied for printing.
Fig. 4 is an enlargement of several of the
interacting components of Fig. 3.
Fig. 5 is a rear end view taken along lines
5-5 of Fig. 2.
Fi~. 1 discloses the silk screened cap
printer generally designated as 10. The cap printer
has a frame 12 which is U-shaped. The frame 12
consists of a crossbar 14 which would correspond to
the base of the Ul a first vertical extension 16 and
a second vertical extension 18. A pair of legs 20
extend outwardly from the crossbar 14 and are
perpendicular to the vertical extensions, for
supporting the frame. For the purpose of this
description the frist vertical extension is
considered to be the front of the printer and the
second vertical extension is considered to be the
rear of the printer.
Mounted upon the first vertical extension
16 and extending toward the second vertical
extension 18 is a saddle 22 for mounting a cap 24,
as shown in Fig. 3. The saddle 22 is shaped similar
to a modified inverted "U" having a flat printing
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surface 26 as the base of the "U" and two side
panels 28 ext~nding downwardly therefrom. Side
panels 28 terminate in bottom cap support edges 70.
A retention bar 30 connects a portion of the rear
edge of one side panel to the rear edge of the other
side panel.
The rear corners of the saddle where the
side panels and the flat printing surface 26 meet
are beveled. The beveled edges 32 and 34 give this
portion of the saddle a supporting shape generally
similar to the shape of the crown of a cap so that
when a cap is placed over the saddle and pulled
taut, the tension is fairly evenly distributed and
creases will not be formed across the intended
printing surface of the cap, the front panel.
Attached to the top of the fîrst vertical
extension 16 is a registration plate 36. The base
of the registration plate 36 is slightly below the
printing surface 26. ~he registration plate is
substantially perpendicular to the printing surface
26 and rises above said printing surface. The
registration plate 36 and the printing surface 26
are secured in a spaced-apart relationship to each
other such that a channel 38 exists between the
plate and the front edge 40 of the printing surface
26.
Mounted atop the second vertical extension
18 is an L-shaped platform 42. The L-shaped
platform 42 has a base portion 44 which is attached
to the second vertical extension 18 and an upright
46 extending perpendicularly upward from the base 44
and attached to the rearmost portion of the base.
Mounted upon the base 44 of the plate 42 is a hinge
48 and mounted to the hinge are two clamps 50. The
clamps move between an advanced position (see Fig.
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3) and a retracted position (see Fig. 2). The base
44 extends forwardly of the hinge 48 so that when
the clamps 50 move to the advanced position, they
will contact the forward portion of the base 44
thereby preventing excess movement beyond the
advanced position. In the advanced position, the
clamps are substantially perpendicular to the base.
Bolted to each clamp 50 is a spring 5Z. This spring
is also bolted to the platform 42 and serves to bias
the clamp to its retracted position.
As shown in Figs. 3 and 4, a cap 24 is
placed over the saddle and is moved forwardly until
the bill 54 comes in contact with the registration
plate 36. The front panel 62 of the cap rests upon
the flat printing surface 26. In addition, the
sweatband 56 is folded out so that it enters the
channel 38. When the cap is mounted in this manner,
a silk screen (not shown) placed within a silk
screen frmae SR which is, in turn, secured in clamps
S0 will move to its advanced position which
corresponds to the advanced position of the clamps
such that the silk screen presses upon the front
panel of the cap.
Prior to applying the silk screen, the cap
is pulled downwardly to create a tension across the
front panel. To pull downwardly on the cap, one can
grasp the adjustment band 60 at the back of the cap.
When pulled downwardly in this manner, the portion
of the bill which connects to the cap will lie below
the flat printing surface as shown in Fig. 5.
Fig. 4 is an enlar~ement of the interrela-
tionship between the registration plate 36, the flat
printing surface 26 and the channel 38 when a cap is
mounted for prin~.ing. As shown in Fig. 4, part of
the front panel 62 of the cap 24 is drawn downwaxdly
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into the channel 3B. Also positioned in the channel
is the sweatband 56 and a portion of the bill 54.
When in positionr the portions of the bill and
sweatband through which the cross section was taken
are slightly rearward of the registration plate 36.
Shown pressing against the registration plate 36 is
the underside of the outward end 64 of the bill 54
(see Fig. 5). When the silk screen frame 58 is
moved to its advanced position, the front part of
the frame contacts the bill and pushes it slightly
toward the registration plate 36. Since the bill 54
of most caps is not flat, but rather is somewhat
raised in the middle where contacted by the frame
58, this creates a small but useful pressure between
the frame 58 and the bill 54 and between the side
edges 64 of the bill and registration plate 36. The
pressure thus created help to secure and stabili2e
the cap during the printing step which follows. At
this point, the silk screen frame is simultaneously
pressing upon the front panel 62, thereby holding
the front panel in place such that the adjustment
band of the cap can be released. In that way, the
hand previously holding the adjustment band is free
to run an ink squeeqee over the silk screen, thereby
transferring the desired image to the cap.
The placement of the bill 54 against the
registration plate 36 results in virtually the same
registration for each cap placed upon the saddle.
In addition, various portions of the saddle serve to
block the cap so that there are no creases on the
Çront panel 62, the tension across the front panel
is fairly uniform and the cap does not move during
printing. The portions of the saddle serving to
block the cap for printing include the beveled edges
34 of printing plate 26 and the beveled edges 32 of
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side plates 28, as previously mentioned, as well as
the front edge 40 and side edges 68 of printing
plate 26, sides 28, bottom support edges 70 of sides
28 and retention bar 30. ~11 these structures
cooperate to produce the desired smoothing and
uniformity of tension across the front panel of the
cap when it is made taut by pulling downwardly on
adjustment band 60.
It is apparent that the above-described
configuration of the saddle prevents creasing and
allows for fairly uniform tension across the entire
front panel of the cap. In addition, the cap is
sufficiently secured to the saddle so as to prevent
any movement during printing. Since the tension is
reasonably uniform, the shrinkage across the front
panel upon removal of the cap is also uniform and
the image is not distorted.
While the above disclosure describes the
preferred embodiment of the present invention, it
will be understood that many variations could be
made and the scope of this invention is intended to
be limited only by the scope of the appended claims.
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