Note: Descriptions are shown in the official language in which they were submitted.
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B~CKGROUND OF THE INYENTION
This invention relates generally to an
improved coating apparatus for applying a coating to
various shaped substrates and for the purposes of
illustration, particularly a non-continuous coating to
various shaped substrates, ore specifically, slender
elongated articles of manufacture of substantially
cylindrical in cross-section, for example, pens, wherein
the non-continuous coating may be any mark, design,
character or the like.
DESCR~PTION OF THE PRIOR ART
Screen printing machines including cylindrical
printing stencils are known in the prior art as
evidenced by U.S. Patent No. 3,785,284 for printing on
continuous webs, U.S. Patent No. 3,665,851 for printing
on curvilinearly shaped articles, e.g. drinking cups,
flower pots, and U.S. Patent No. 3,903,792.
SUhM~RY OF THE INVENTION
This invention relates generally to a printing
machine including at leaat one rotatable coating drum
having a hollow lnterior adapted to contain a coating
material, more specifically an ink compoqltion, and a
foraminous pattern screen, for example a silk screen,
associated with the interior or exterior surface of the
drum for applying a non-continuou~ coating to substrates
of various shapes. The machlne lncludes a method to
convey by lntermittent conveyor meana or continuous
means constructed to convey a plurality of individual
apaced substrates to a position ad~acent to the coating
drum and an elevating device may be used. The elevating
device may be conatructed for intermittently removing an
individual aubatrate from the conveyor means and
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positioning the substrate into tangential contact with
the peripheral surface of the drum whereby rotation of
the drum produces a coating on the surface of the
substrate. The conveyor means is optional as an operator
may manually position a substrate on the elevating
device.
It is an object of the invention to construct
a machine capable of functioning safely at high mass
production rates for applying a coating on the outer
surface of substrates at a rate of at least 100
substrates per minute.
It is a further object of the invention to
construct a machine so designed for easily manually or
automatically rece~ving individual substrates without
affecting the continuous operation of the machine.
It is a still further object of the invention
to design a coating machine intermittant in operation
thereby facilitating manual inspection of each of the
coated substrates for facilitating discarding of
imperfectly coated substrates.
It is an additlonal object of the invention to
fabricate a machine capable of coating a plurality of
individual products at a ~elected position of the outer
surface thereof.
It is a ~till further object of the invention
to fabricate a coating drum for applying non-uniform
coatings to a sub~trate.
It ls a still additional object of the
invention to fabricate a novel printing ~creen for use
with a rotary drum.
In accordance with these and other objects
which will be apparent hereinafter, the instant
inventlon will now be descrlbed wlth partlcular
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reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRA~ING
Figure 1 i~ an isometric view of the
cylindrical drum of the printer.
Figure 2 i~ an isometric view of the screen.
Figure 3 is a cros~ sectional side view of the
cylindrical drum.
Figure 4 is a side view of the cylindrical
drum of the printer and conveyor.
Figure 5 is an isometric view of the wiper arm
for the cylindrical drum.
Figure 6 is a side view of the wiper arm for
the cylindrical drum.
Figure 7 is a front view of the cylindrical
drum of the printer and conveyor.
DET~ILED DESCRIPTION OF THE INVENTION
CONVEYOR
With reference to the several views of the
drawing, there is depicted a rotary screen printing
machine including a pair of spaced linked chain
conveyors 10, each having individual triangular elements
12 secured to rods connecting each link 25 of the chain.
Each trlangular element 12 is contiguous to each other
thereby formlng saw teeth in appearance, the valleys
thereof adapted to receive individual ~ubstrates either
manually or mechanically placed therein. The conveyor
links are rotatably supported or mounted on tracks 30.
On the opposed sides of the conveyors are guide ralls
35, 40 engageable with the opposite ends of the
8ubstrates for maintalning the ob~ects ln a
predetermined position thereby resulting in printing of
each ~ubstrate 3ub~tantially or exactly on the ~ame
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surface area of each object.
CYLIND~ L STENCIL
Positioned above the conveyor, described
above, is a cylindrical hollow printing drum 45 having
an opening 46 for accomodating a pattern screen and
having a closed face 50 end removably secured to
rotatable drive means 55 for effecting rotary movement
of the drum. The opposite face 60 is open, as
illustrated, and includes a cylindrical flange ~5 for
retaining ink in the interior of the drum. The interior
of the drum includes an internal screen resilient wiper
blade 70 of, for example, rubber or similar material,
secured to a thin flexible steel member of approximately
0.015" thick. The blade 70 can easily be adjusted in
various critical angular positions relative to the inner
periphery of the rotary drum, more specifically at 90`,
135` and 225` to an imaginary horizontal line tangent to
the periphery of the drum. The means effecting the
different angular positions is generally indicated by
reference numeral 74 which mean~ 74 includes a shaft 75
on which the wiper blade is secured.Shaft 75 is mounted
on L-shaped bracket 80 secured to member 85. Member 85
is ad~ustably mounted on a lock-screw manually movable
by hand knob 95. This construction permits raising or
lowering of the wiper blade and for ad~usting the
angular posit$on of the squeegee and the numerical
pre~ure of the end of the wiper blade on the internal
peripheral surface of the rotary drum. The ad~usted
values can be read from a dial gauge (not shown). Wiper
blade 70 may be ad~ustably rotated on shaft 75 to
compensate for wearing due to occa~lonally sharpening of
the end of the wlper by, for example, a sander, whlch
shortens the length thereof. Eventually, however, the
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blade can be replaced as it l~ removably mounted on
shaft 75 and on the steel member.
Figures 5 and 6 illustrates a further
embodiment for mounting shaft 75 by utilizing a clamp,
generally indicated by reference numeral 174, in lieu of
using fixed bracket 80. Claim 174 includes a pair of
members 174, 176, movable relative to each other,
element 175 being pivotally mounted to aforementioned
member 85 at 177 and element 176 also being fixed
permanently to member 85. Pivoted element 175 includes
an internally threaded aperture 178 threadedly receiving
and externally threaded rod 179 having a handle 180 at
one end, the opposite end thereof being engagable with a
recess 181 in member 176 which prevents lateral movement
of the rod 179 of member 176 includes a second recess
182-ac¢ommodating ~haft 75. Rotation of rod 179 affects
movement of member 175 relative to member 176 to engage
and clamp ~haft 75 thereby maintaining shaft 75 in its
operative po~ition.
Prlnt drum 45 is removably mounted in the
manner of a cantilevar on drive shaft 55 via keyway 57
for rapid lnterchange of various drums including
dlfferent colored composltions as well as permitting
cleanlng thereof. The posltlon of the print drum can be
ad~u~ted ln lt~ relatlonship to a ~ubstrate by a palr of
elevating screw~ 46 ~only one belng illustrated) which
lnclude~ a lock nut 47 and a screw clamp 48 functlonal
connected to the frame ~upporting the print drum.
Illu~trated ln Flgures 2 and 3, l~ a detalled
vlew of a prlntlng screen generally lndicated by numeral
300 for a~soclatlon with rotary drum 45. The prlntlng
~creen comprises a flexible lamlnate lnculdlng a thln
flexlble pla-~tlc ga~ket 302 and a prlntlng screen 304
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attached thereto by glue or tape. Ga~ket 302 i~ about
1/16n thick and could contain a plurality of magnetic
particles distributed throughout the plastic for
connection purposes instead of tape and clamp and
s further has an opening 306 of about the same dimensions
as opening 46 in drum 45. Printing screen 304 is formed
by conventional photographic emulsion techniques with
use of high energy radiation, e.g. ion beam. This
technique permits fabrication of an extremely thin
printing laminate which facilitates passage of coating
materlal through the individual foramen of the screen
with formation of distinct non-continuous coatings on a
substrate without smearing of the coatings. The laminate
can thus be magnetically maintained on the periphery of
the drum. Clamping of the silk screen to the drum is
accomplished by a reailient flexible band 90 encircling
the drum which includes an opening 95 of dimensions
about that of the silk screen. Band 90 includes
complementary engageable means 98 similar in
construction to a hose clamp, for connecting the
oppo~ite ends of the band for fixedly securing the band
to the drum.
The relationship of the ~ize screen and
rotational speed of the drum for applying coating3 of
varlous th$cknesseq is qet forth in the Table below:
~creen No. Speed R.P.M. LD~LDL~ o~
2~o 188 1 i gdhi t
4~ 100 heavy
240 130 heavy
ELEVATOR
The ob~ect to be printed is lifted in po~itlon
by an elevating mechanism generally designated by
numeral 100 and illu-~trated in detail in Figure 7. The
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elevating mechanism includes a camshaft 105 having fixed
thereto an elevating cam 110 ~ecured thereto by a
conventional means, e.g. a set ~crew, the cam being of
conventlonal design. A cam follower 115 engages the
peripheral surface of the cam and is freely mounted for
rotation on shaft 120 thereby enabling raising and
lowering of said shaft. A substrate fixture 125 is
mounted at the upper end of shaft 120 and is positioned
between the pair of link chain conveyors. The fixture
125 includes a T-shaped member 130 rockably supported to
the upper end of shaft 120 by a pivot pin 135. Secured
to member 130 are a pair of L-shaped brackets 140 via
bolts or like fastening mean~ 145 to each of which are
mounted a pair of spaced rollers 150 freely mounted on a
pair of shafts secured to bracket 140. The spacing
between the rollers is of a distance sufficient to
support a substate therebetween.
Another embodiment of the elevating mechanism
ls shown in Figure and includes a pair of rollers 150',
~imilar to rollers 150, mounted in a support 152' biased
by tension spring 154' into contact with the rotary
drum. The ten~ion of the spring may be adjusted by an
ad~usting feature.
Mounted laterally of shaft 120 is a member 155
secured to the shaft via bolt and bracket 160. Member
155 includes an opening for receiving shaft 165
including a resilient cu~hioning element 170. A magnet
170 is mounted on a ~upport 175 fixed to end of shaft
165, the magnet functioning to rotate a non-magnetic
substrate by the magnetic attraction of a piece of metal
mounted on the non-magnetic sub~trate. The elements
120-175 constitute a ~ubstrate outboard support. The
slde of support 175 includes adding support means 180
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for the depressible part of the substrate which ls of
known construction.
The lower end of shaft 120 includes means
generally indicated by numeral 200 for adjusting the
5 operating position of rollers 150, the mean~ 200
comprises pivot rod 205 pivotally mounted to member 130
via pivot pin 210 which is adjusted by adjusting knob
220 which is locked in position by lock screw 225. Also,
secured to shaft 120 are means 230, 235 retaining a
spring 240 functioning to return shaft 120 to its
inoperative position when cam-follower 115 returns to
the dwell position of oam 110. Element 235 includes a
shock absorbing washer 240.
~IY MECHANISM
The drive means for synchonous movement of
conveyor 10, print drum 45, elevator mechanism 100 is
generally lndicated by reference numeral 200 which
includes drive shaft 210. Fixed to shaft 210 is a limit
switch cam 220 which is cyclically engaged~by limit
switch 230. A D.C. motor i~ used to furnish the power
through a speed reducer and torque limits. This gives an
lndefinite speed from 0 to 100 pens per minute.
Qp~ATI0~11 QE MACHINE
Subtrates, more specifically pens, are placed
on conveyor 10, and are moved to po~ition A at which
time the substrate i8 lifted by the elevating mechanism
100 into engagement with a continuously rotating
printing drum 45 which may be ad~usted to attain the
optimum radial position of thereof. The wiper blade may
be positioned that one corner of the blade is tangent to
the pen in ltq print po~itlon in order to obtain the
optimum quallty of printlng on the substrate.
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It will be apparent that varlou~ modlflcations
may be made to the speclflc structural embodlment~
dlscussed above wlthout departlng from the scope Or the
invention.
It ~hould be noted that the ob~ect receiving
the print or surface can be circular a~ shown or flat or
conical or other shapes. Further the drum may be
cylindrical as shown or may be conical or oval or any
other such shape.
The instant invention has been shown and
de~cribed herein in what is consldered to be the most
practical and preferred embodlment. It is recognized,
however, that departures may be made therefrom within
the scope of the invention and that obvious
lS modifications will occur to a per~on skllled in the art.
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