U.S. patent number 3,735,730 [Application Number 05/099,771] was granted by the patent office on 1973-05-29 for apparatus for applying a flowable medium to a carrier.
This patent grant is currently assigned to Mitter & Co.. Invention is credited to Matthias Mitter.
United States Patent |
3,735,730 |
Mitter |
May 29, 1973 |
APPARATUS FOR APPLYING A FLOWABLE MEDIUM TO A CARRIER
Abstract
A flowable medium is to be supplied to an exposed surface of a
carrier, for instance a web which is to be printed. A supply
arrangement supplies the flowable medium to the vicinity of the
exposed surface and an applicator arrangement is provided for
applying it to the exposed surface. The applicator includes a
hollow spreading element of elastically distendable material which
engages either the exposed surface directly, or engages a portion
of the applicator arrangement which is operatively associated with
the exposed surface, and admitting means is provided for admitting
requisite quantities of pressurized fluid to the interior of the
hollow spreading element whereby to distend the latter to various
extents and thus vary its engaging pressure.
Inventors: |
Mitter; Matthias (Senne,
DT) |
Assignee: |
Mitter & Co. (Schloss
Holte, DT)
|
Family
ID: |
5754634 |
Appl.
No.: |
05/099,771 |
Filed: |
December 21, 1970 |
Foreign Application Priority Data
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Dec 22, 1969 [DT] |
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P 19 64 182.8 |
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Current U.S.
Class: |
118/205; 68/200;
101/119; 101/120; 118/213 |
Current CPC
Class: |
B41L
13/04 (20130101); B41F 15/44 (20130101) |
Current International
Class: |
B41L
13/04 (20060101); B41F 15/14 (20060101); B41F
15/44 (20060101); B05c 001/00 (); B41j 013/00 ();
B41f 015/42 () |
Field of
Search: |
;118/213,205
;101/116,119,120 ;68/200 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
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266,024 |
|
Nov 1968 |
|
OE |
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467,160 |
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Feb 1969 |
|
CH |
|
Other References
1,267,231 5-1968 German Application (Weber).
|
Primary Examiner: Kee Chi; James
Claims
What is claimed as new and desired to be protected by Letters
Patent is set forth in the appended
1. In an apparatus for applying a flowable medium to a carrier, in
combination, carrier means having an exposed surface; a supply
arrangement for supplying a flowable medium to the vicinity of said
exposed surface; applying means mounted proximal to said carrier
means and having a contact face proximal to said exposed surface
for spreading said flowable medium on the latter, said contact face
including with said exposed surface an angle and at least one of
said means being mounted at least in part for travel with reference
to the other means, said applying means comprising an at least
partially hollow tubular spreading element consisting at least
partly of elastically distendable material associated with said
contact face, and a holder for said spreading element; and varying
means for varying the angle included between said contact face and
said exposed surface at the will of an operator.
2. In an apparatus as defined in claim 1, wherein said applying
means comprises a rotary drum permeable to said flowable medium
mounted adjacent said carrier means and having an outer side
proximal to said exposed surface and an inner side onto which said
flowable medium is supplied; and wherein said hollow spreading
element is mounted within said drum stationarily relative thereto,
with said contact face engaging said inner side under pressure.
3. In an apparatus as defined in claim 2, wherein said varying
means comprises a source of fluid under pressure, and admitting
means communicating with said source and the interior of said
spreading element for admitting into the latter a quantity of such
fluid requisite for distending the material of said spreading
element to a desired extent.
4. In an apparatus as defined in claim 3, said admitting means
comprising valve means for continuously varying the admittance of
fluid to the interior of said spreading element, whereby to
continuously vary the distending of the material of the same.
5. In an apparatus as defined in claim 3, said supply arrangement
including a supply conduit extending into said drum axially of the
same; and further comprising holding means arranged in said drum
below said supply conduit for holding said spreading element in
requisite relationship with reference to said exposed surface.
6. In an apparatus as defined in claim 5, wherein said holding
means in an elongated substantially U-shaped member having an open
side, and wherein said spreading element comprises a distendable
hose portion accommodated in and extending longitudinally of said
U-shaped member, and a substantially U-shaped channel portion of
elastically distendable material embracing said hose portion and in
part extending outwardly through said open side, said channel
portion being provided with said contact face.
7. In an apparatus as defined in claim 6, wherein said hose portion
and said channel portion consist at least predominantly of
elastomeric material.
8. In an apparatus as defined in claim 6, said U-shaped member
having two lateral arms each extending axially of said drum, one of
said arms being located upstream of the other arm with reference to
the rotation of said drum; and wherein said channel member has a
first lateral wall portion bonded to said one arm, a second lateral
wall portion loosely abutting said other arm, and a bight wall
portion provided with said contact face with the latter facing said
exposed surface and including therewith a variable acute angle.
9. In an apparatus as defined in claim 8, said arms each having an
inwardly directed side facing the interior of said U-shaped member;
and wherein said first and second lateral wall portions each engage
the inwardly directed sides of the respective arms.
10. In an apparatus as defined in claim 8, wherein said contact
face is inclined towards said exposed surface in direction from
said one arm towards said other arm.
11. In an apparatus as defined in claim 10, said arms each having a
longitudinally extending free marginal zone; and wherein said
marginal zone of said other arm is closer to said exposed surface
than said marginal zone of said one arm and includes with the
remainder of said other arm an obtuse angle in direction of
rotation of said drum.
12. In an apparatus as defined in claim 6, said U-shaped member
having a bight portion facing away from said open side and from
said exposed surface; and wherein said hose portion is connected
with said U-shaped member in the region of said bight portion of
the latter.
13. In an apparatus as defined in claim 5; further comprising
support means engaging said supply conduit, holding means and
spreading element in the region of the opposite axial ends of said
drum; and wherein said varying means are operative for continuously
varying the distance of said supply conduit, holding means and
spreading element from said exposed surface of said carrier
means.
14. In an apparatus as defined in claim 13, said support means
comprising at least two supports, and said varying means comprising
at least two varying arrangements each associated with one of said
supports and operable independently of the other varying
arrangement.
15. In an apparatus as defined in claim 4; and further comprising a
pressure-indicating device operatively associated with said valve
means for indicating the pressure of fluid prevailing in the
interior of said spreading element.
16. In an apparatus as defined in claim 8, said channel portion
having a pressure-exerting contact edge at the juncture of said
bight wall portion with said second lateral wall portion; and
further comprising a substantially L-shaped elongated reinforcing
component for said contact edge exteriorly embracing said juncture
and fast with said channel portion.
17. In an apparatus as defined in claim 16, wherein said
reinforcing component consists of sheet steel.
18. In an apparatus as defined in claim 8; and further comprising
an elongated internal reinforcing component of substantially
L-shaped cross-section located interiorly of said channel
portion.
19. In an apparatus as defined in claim 18, wherein said internal
reinforcing component is located within said hose portion.
20. In an apparatus as defined in claim 18, wherein said internal
reinforcing component is located intermediate and in contact with
said hose portion and said channel portion.
Description
BACKGROUND OF THE INVENTION
The present invention is generally concerned with an apparatus for
applying a flowable medium to a carrier, and more particularly with
an apparatus for applying liquids, pastes and similar media to an
exposed surface of such a carrier.
Apparatus of this type finds a wide range of different applications
and it is to be understood that the invention is applicable to
apparatus suitable for this purpose, irrespective of the particular
application to which the apparatus is put. However, purely by way
of example it is pointed out that such apparatus may for instance
be in the form of rotary printing machines, litho printing machines
or the like, and that the flowable media to be applied may include
printer's ink, ink or paint in general, adhesives or various
coating materials.
From the printing art, for instance, it is known to provide rotary
printing presses with rotating foil drums which cooperate with
spreading elements serving to spread the supplied flowable medium
onto an exposed surface of a carrier adjacent the drum. The
spreading elements are rigid and have spreading edges which are
usually formed by grinding. The spreading element is arranged with
reference to the surface on which the flowable medium is to be
spread, in a predetermined orientation, and the spreading edge is
ground so as to be inclined at a specific angle to the surface when
the spreading element is so oriented. For different types of
flowable medium, and also for different densities and the like of
the flowable medium, spreading elements with differently ground
spreading edges are required, and also it is usually necessary that
the spreading elements themselves have various different
hardnesses.
The prior art presents a problem in that for instance in the
application of printer's ink it is never clear from the beginning
how strongly the ink is to be applied and therefore precisely which
of various different spreading elements is to be employed. This
becomes clear only after the first several yards of material have
been printed, at which time a determination can be correctly made
which particular spreading element to use. Of course, if by chance
the proper spreading element has been employed to begin with, then
there is no problem; however, if the spreading element is not
suitable because it spreads too little or too much printer's ink,
for instance, then it is necessary to stop the printing press,
remove the spreading element in it and install a different suitable
spreading element. This is not only disadvantageous in terms of
time lost, but also in terms of material lost, it being evident
that the initially printed material will be wasted and that further
losses accrue for instance from the loss of printer's ink during
the down-time of the machine.
The known spreading elements are possessed of additional
advantages. Thus, they are secured at their opposite longitudinally
spaced ends and pressure which is applied to them in order to vary
the degree of pressure with which they engage the surface on which
the flowable medium is to be spread, is applied at these ends.
Evidently, and keeping in mind that the spreading elements extend
across the width of the printing machine, that is the width of the
material to be printed or otherwise provided with a flowable
medium, it is clear that the broader the machine will be the longer
will be the spreading element, and the more the spreading element
will have a tendency to bend in its center region as a result of
pressure applied to it at its opposite ends. This, of course,
results in the uneven spreading of the flowable medium onto the
exposed surface of a carrier, such as the material to be printed,
in the center region and in the end regions of the spreading
element. Increasing the pressure at the ends will not remedy this
condition because the proportional difference of pressure in the
center region and at the ends, that is pressure exerted by the
spreading element upon the material on which the flowable medium is
to be spread, will not vary as a result of such adjustments.
An attempt to overcome these problems is to be found in another
concept of the art, utilizing so-called magnet rollers as the
spreading element. These are rollers of magnetic or magnetizable
material which contact the surface on which the flowable medium is
to be spread, and which cooperate with magnetizable or magnetic
counter-elements located beneath the material and which attract the
roller with equal force over the entire length thereof against the
exposed surface, whereby even spreading of the flowable medium is
obtained. The density of the layer of flowable medium which is
applied can also be regulated, by regulating the magnetic field
with a resultant change in the pressure with which the roller is
attracted to the exposed surface.
However, in this prior-art approach there are also inherent certain
disadvantages. In particular, the quantity of flowable medium which
is applied and spread is regulated by using rollers of different
diameter. This necessitates that if before start-up of the machine
a roller of improper diameter has been selected--a fact which will
become evidently only after the first few yards of material have
been printed or coated, it is again necessary to stop the machine,
remove the roller and install a roller of different and more
suitable diameter. Evidently, this will then bring with it the
aforementioned disadvantages in terms of down-time and losses of
material.
SUMMARY OF THE INVENTION
It is, accordingly, an object of the present invention to overcome
the aforementioned disadvantages.
More particularly it is an object of the invention to provide an
improved apparatus for applying a flowable medium to a carrier, an
apparatus which is not possessed of the disadvantages outlined
above.
A concomitant object of the invention is to provide such an
apparatus which is provided with a spreading element which not only
will apply the flowable medium evenly at all points, but whose
pressure upon the exposed surface and whose density of application
of the flowable medium can be varied continuously during the
operation of a machine provided with it.
In pursuance of the above objects, and others which will become
apparent hereafter, I provide in an apparatus for applying a
flowable medium to a carrier, a combination which briefly stated
comprises carrier means having an exposed surface, and a supply
arrangement for supplying a flowable medium to the vicinity of this
exposed surface. I further provide applying means mounted proximal
to the carrier means with at least one of these means being mounted
at least in part for travel with reference to the other. The
applying means comprises an at least partially hollow spreading
element of elastically distendable material having a contact face
proximal to the exposed surface for spreading the flowable medium
on the latter. The applying means further comprises distending
means which acts interiorly of the spreading element for the
purpose of distending the material of the same to a selectable
extent, whereby to change the orientation and proximity of the
contact face with reference to the exposed surface.
By resorting to my invention, there is provided an apparatus of the
character in question which is particularly suitable for use in
modern high-speed, high-precision machinery, especially but not
exclusively in rotary printing presses. My invention makes it
possible to not only continuously vary the pressure with which the
spreading element engages a surface with which it cooperates, but
also to continuously vary its configuration and thereby the
configuration of its contact face which contacts a cooperating
surface and spreads the flowable medium thereon. In this manner the
depth of penetration on on the one hand, and on the other hand the
quantity of applied flowable medium can be continuously varied and
an extremely fine regulation of the application of the flowable
medium is assured. As pointed out before, this is particularly
important in printing presses, including those which operate on the
screen-printing principles, because the application in
screen-printing presse depends on the one hand upon the type of
spreading element employed, on the other hand upon the viscosity of
the flowable medium (in this case printer's ink) which is utilized,
and finally upon the rate of permeability of the screen itself. In
the known apparatuses these three factors must be coordinated with
one another prior to beginning of the printing operation and can be
varied with reference to each other only within a very narrow range
of possibilities. If one of the factors deviates substantially, the
machine must be stopped and the necessary adjustments must be made
as by exchanging one spreading element for another in the manner
and for the reasons outlined earlier.
All of these problems are overcome with the present invention which
permits adjustments not only continuously but also during the
operation of the machine provided with the invention.
The novel features which are considered as characteristic for the
invention are set forth in particular in the appended claims. The
invention itself, however, both as to its construction and method
of operation, together with additional objects and advantages
thereof, will be best understood from the following description of
specific embodiments when read in connection with the accompanying
drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a somewhat diagrammatic fragmentary end-elevational view
of an apparatus provided with one embodiment of the invention;
FIG. 2 is a somewhat diagrammatic side-elevational view, on an
enlarged scale, of the apparatus shown in FIG. 1;
FIG. 3 is a fragmentary transverse sectional elevation through the
apparatus of FIGS. 1 and 2 showing one condition of adjustment of
the apparatus;
FIG. 4 is a view similar to FIG. 3 but showing a different
condition of adjustment of the same apparatus;
FIG. 5 is a view similar to FIGS. 3 and 4 showing still a third
condition of adjustment of the same apparatus;
FIG. 6 is a fragmentary detail view illustrating a further
embodiment of the invention;
FIG. 7 is a view similar to FIG. 6 illustrating an additional
embodiment of the invention;
FIG. 8 is a view similar to FIG. 3 illustrating another embodiment
of the invention;
FIG. 9 is a view similar to FIG. 8 showing a further embodiment of
the invention;
FIG. 10 is a view similar to FIG. 9 showing a different embodiment
of the invention;
FIG. 11 is a view similar to FIG. 10 but showing a modified
embodiment of the invention;
FIG. 12 shows still another embodiment of the invention in a view
similar to FIG. 11;
FIG. 13 shows, in a somewhat simplified view analogous to FIG. 11,
a further embodiment of the invention; and
FIG. 14 is a view similar to FIG. 13 showing yet another embodiment
of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Discussing now the drawing in detail, and firstly the embodiment
illustrated in FIGS. 1-5 thereof, it will be seen that reference
numeral 1 diagrammatically and fragmentarily identifies a support
of an apparatus, for instance a frame, base or the like. The
support may be made adjustable so that it can be raised and lowered
if desired. How this can be done is not new and those conversant
with this field will be aware of various possibilities. Mounted on
the support 1 is a supply conduit 2 for a flowable medium, for
instance printer's ink. Journals 3 and 4 mount the supply conduit 2
and the double-headed arrows in FIG. 1 indicate that in known
manner the arrangement may be such that the conduit 2 can be raised
and lowered with reference to the support 1. In fact, it is
advantageous if the adjustment of the journals 3 and 4 can be
carried out individually, so that by operating only one of the
journals, or operating the journals 3 and 4 to different extents,
the conduit 2 may be inclined axially if so desired.
In the embodiment of FIGS. 1-5 I have illustrated a drum 5 which
rotates in the direction indicated by the arrowheads in FIGS. 3-5
(where the drum 5 is shown diagrammatically and fragmentarily
only). Such a drum will usually be a film-printing drum of known
construction, but details of the particular construction of the
drum 5 are immaterial for an understanding of the invention.
The conduit 2 extends axially through the drum 5 which is mounted
for rotation in known manner which is not separately illustrated.
It is provided with apertures 12 (compare FIGS. 3-5) which are
distributed evenly over its length, that is over that portion of
the conduit 2 which is located within the confines of the drum 5.
The diagrammatically illustrated source of flowable medium (compare
FIG. 1) can be connected with the interior of conduit 2 so as to
supply flowable medium to the latter from where it then escapes
through the apertures 12 into a chamber 7 which is bounded by a
sheet material wall 6. The wall 6 itself is also provided with
apertures, identified with reference numeral 16 in FIG. 3, through
which the flowable medium leaves the chamber 7 to flow onto the
inner side of the drum 5 and to there merge with the quantity 8
which is already in position there. This assumes, of course, that
the press is already in operation. If the press is not in
operation, then the flowable medium escaping through the apertures
16 will first form the supply 8 on the inner side as shown in FIG.
3. The maximum build-up of the supply 8 is controlled in known
manner by an electrode 9 which is connected electrically also in
known manner with a non-illustrated pump supplying the flowable
medium from the source, and which de-activates the pump as soon as
a circuit is completed in response to contact with the tip of the
electrode with the supply 8. Of course, other possibilities for
controlling the level of the supply 8 also exist, and it need not
be the pump that is controlled but it could be a valve or the
like.
It will be appreciated that printer's ink may constitute the
flowable medium, but any other kind of viscous pasty medium can be
supplied, and that in place of the rotary drum 5 a flat applying
member--such as a flat screen--may be utilized. In the latter case
it may be possible to dispense with the conduit 2 and to supply the
flowable medium in another suitable manner, but then the spreading
element according to the invention, which will be discussed
presently must be so mounted that it can be moved with reference to
the surface on which the flowable medium is to be spread. In fact,
it is also possible to employ the spreading element according to
the present invention without an intermediate applicator member,
that is without the drum 5 or a flat screen or applicator in lieu
of the drum 5.
As shown in the embodiment of FIGS. 1-3, and especially in FIGS.
3-5, there is provided below an extending longitudinally of the
conduit 2, a substantially U-shaped holding element 10 which may
consist of steel or another suitable material and whose open side
faces in direction downwardly, namely towards the inner side of the
drum 5 and thereby towards the exposed surface of the carrier 14
which is to be provided with the flowable medium. For purposes of
the discussion it shall be assumed that the carrier 14 here is a
sheet-material web. The holding element 10 carries the actual
spreading element according to the present invention which in the
embodiment of FIGS. 1-5 consists essentially of a hose portion 11
which is embraced from the open side of the element 10 by another
substantially U-shaped member, a channel portion 13 which embraces
the hose portion 11. The hose portion 11 as well as the channel
portion 13 are at least essentially composed of elastically
distendable material, such as a suitable natural or synthetic
elastomer which may be reinforced with a fabric or in another
suitable manner.
The channel portion 13 is provided with a downwardly directed
contact face 23 which is inclined with reference to the exposed
surface of the carrier 14 at an acute angle .alpha.. The carrier 14
is disposed on a printer's blanket 15 which in turn is accommodated
on a work table 17.
The hollow interior of the spreading element composed of the
portions and 13 is identified with reference numeral 18 and is in
communication with a diagrammatically illustrated pressure fluid
source (see FIG. 3) via one or more conduits 19 in which there is
advantageously installed a pressure-measuring instrument 20 so
located that it can be observed by an operator.
Via the pressure fluid source and a suitable valve of which a
regulating component 22 is illustrated in FIGS. 3-5, the pressure
in the interior 18 can be regulated whereby in dependence upon the
prevailing pressure, the material of the portions 11 and 13 is
outwardly distended through different extents, with a concomitant
variation of the angle .alpha.. It is preferable that the valve 22
be of a type--known to those skilled in the art--which permits a
continuous variation of the pressure in the space 18 so that a
continuous variation of the angle .alpha. becomes possible.
It is of course normally desirable to avoid the possibility that
the portions 11 and 13 might become dislodged from the element 10
during the operation of the apparatus, including distending of the
portions 11 and 13 to different extents. In order to counteract
such danger it is advantageous that a side wall portion of the
portion 13 which trails or is located downstream with reference to
the direction of movement of the drum 5, be adhesively connected or
otherwise suitably bonded to the arm 10a of the element 10. The
bonding is identified at 21. On the other hand, the other side wall
portion of the portion 13 simply frictionally but loosely abuts the
inner side of the arm 10b so that it can move with reference to the
same. The arm 10b extends closer towards the surface of the carrier
14 than the arm 10a and its lower marginal portion 10' is bent over
upwardly and in downstream direction of movement of the drum 5, as
illustrated in FIGS. 3-5. The purpose is to permit flexing in
downstream direction of the edge 33 formed at the juncture between
the downstream wall portion and the portion provided with the
surface 23, of the portion 13.
It is emphasized that it is immaterial what particular pressure
fluid is employed for distending the inventive spreading element.
Thus, air, steam, a liquid or any particular desired type of gas
can be employed, but compressed air is advantageous in terms of
economy.
As the pressure in the chamber 18 increases, and given the fact
that the conduit 2 is fixed with the support 1 and that the drum 5
rotates in the indicated direction, the configuration of the
spreading element will vary. This is evident from a comparison of
FIGS. 3 and 4, with a state of increased internal pressure being
illustrated in the latter Figure.
It is clear that the greater the pressure in the space 18, the
smaller will become the angle .alpha. and the stronger will be the
application of flowable medium. Also, the increased pressure in the
space 18 with a consequent flattening-out of the edge portion 33,
causes the quantity of medium which is pressed through the
apertures of the drum 5 to be increased and thereby to increase the
quantity of such flowable medium which is applied to the carrier
14. Evidently, these factors can be continuously varied by simply
varying via the valve 22 the quantity of pressure fluid which is
admitted into the space 18, and thereby to vary the pressure in the
latter, so that the results in terms of flowable medium applied to
the exposed surface of the carrier 14 can be precisely accommodated
to any given requirement without having at any time to exchange or
replace components of the apparatus.
Because of the possibility which is illustrated in FIG. 1 by the
double-headed arrows, of adjusting the position of the conduit 2
upward and downwardly, and thereby of the hollow spreading element
which is carried by it via the element 10, further variations in
the action of the spreading element can be obtained. If the
increased pressure is applied as in FIG. 4, then the entire
assembly of the components 2, 10, 11 and 13 is raised by raising
the conduit 2 in the manner suggested with reference to FIG. 1,
then a larger angle .alpha. will be obtained as illustrated in FIG.
5, and the edge portion 33 will contact the inner side of the drum
5 along a smaller surface, whereby much finer applications of the
flowable medium can be achieved. To obtain still finer applications
the edge portion 33 may be exteriorly armored by an angled
substantially L-shaped elongated element 25 as illustrated in FIG.
6, with such element preferably consisting of sheet steel. This
further resists deflection of the edge portion 33.
On the other hand it is also possible to provide an interior
armoring element of again substantially L-shaped configuration,
identified with reference numeral 26 in FIG. 7. This immediately
provides for a small angle .alpha. and for a rather flat edge
portion 3 so that the surface contact of the portion 33 with the
inner side of the drum 5 is larger than for instance in FIG. 3 even
before internal pressure is applied. The element 26 may be located
in the interior of the hose portion 11 as shown, or it may be
located between the exterior of the hose portion 11 and the
interior of the channel portion 13.
Naturally, the cross-sectional configuration of the element 10 may
also be varied from what has been illustrated. It is advantageous
if the arm 10b is longer that the arm 10a, meaning that it extends
closer towards the inner side of the drum 5 than the arm 10a, as
illustrated in FIGS. 3-5. The angling of the margin 10' of the arm
10b provides for an abutment of the edge portion 33 when the same
is deflected by the rotating drum as illustrated in FIG. 4.
Similarly, the configuration of the hose portion 11 and/or that of
the channel portion 13 may be varied.
In FIGS. 8-14 I have illustrated further embodiments of the
invention. Here the hollow spreading element is preferably of
substantially T-shaped cross-section and composed of two preferably
but not necessarily unitary portions one of which is identified
with reference numeral 53 and constitutes the crosspiece of the T,
and the other of which is hollow, relatively tall and of
substantially or completely acute-angular configuration. The
portion is identified with reference numeral 60 and is engaged by a
holding element 50 which may have the illustrated shape and which
in turn is connected with a bracket 58 secured to the conduit 2, in
FIG. 8 by means of the illustrated screw connection. The portion 53
can be inserted endwise into an open end of the element 50 and can
similarly be removed.
In the embodiments of FIGS. 13 and 14 I have illustrated the
possibility of using the present invention with a planar or flat
applicator or screen 5' instead of the drum 5. Of course, if as is
possible the flowable medium is supplied in a manner other than via
the conduit 2 so that the latter is omitted, then the spreading
element must be mounted on a carriage which is capable of
traversing the applicator 5'. How this can be done is well known to
those skilled in the art, for instance screw spindles may be
provided on which the carriage is mounted and which make it
movable.
In FIGS. 8-12 I have illustrated a cross-sectional configuration of
the applicator element wherein the element is of substantially
acute-angular outline with a contact portion 52 which is outwardly
curved and with a trailing wall portion 51 which is convex in
upstream direction. Of course, the cross-sectional configuration of
the spreading elements in these Figures can be varied, as can be
that of the holding element 50 in each embodiment. It is only
essential that the spreading element be reliably connected with the
element 50 and that the inner space to be pressurized, identified
with reference numerals 54, 59 or 63-65 in the embodiments of FIGS.
8-12, be of relatively tall or high cross-section as shown.
Again, the pressure can be varied in these interior spaces whereby
the angle .alpha. can be changed accordingly, this being
accomplished in the same manner as discussed with reference to the
preceding embodiment, and as also illustrated in FIG. 12 via the
valve 22 and the pressure-indicating device 20. The variation in
the configuration of the spreading element can be made continuously
in this manner.
It is clear that thus the purposes of the present invention are
achieved with these embodiments also. It is parenthetically pointed
out that in FIG. 13 the configuration of the portion of the
spreading element which is provided with the internal space 64, is
shown in broken lines as it will be if it is retracted sufficiently
so that it does not contact the applicator element 5'. The
full-line position will be assumed when contact is made and
relative movement occurs.
The pressure of the spreading element against the drum 5 or the
applicator element 5', but not its elasticity and stability, can be
varied in known manner by adjusting the spacing of the
support--that is in most instances the conduit 2 carrying the
spreading element--with reference to the surface of the carrier 14
which has been omitted in several of the latter embodiments. This
adjustment can also be made continuous.
When pressure is admitted into the interior spaces, the
configuration in cross-section of these interior spaces would tend
to round out, rather than to keep its vertically elongated shape.
To overcome this FIGS. 8 to 11 show a reinforcing or supporting
abutment 56 which may be configurated to be of triangular shape by
adding a portion 57. It extends downwardly towards the surface of
the carrier 14 to such an extent that the edge 52 is still freely
movable and can move beneath the lower free edge portion of the
reinforcing abutment 56 when deflected by contact with the rotating
drum, or with an analogous element.
The wall portion 51 is convex in upstream direction. It may be
reinforced by being made thicker than the opposite wall portion as
illustrated for instance in FIG. 12, or it may be made of a
material having a greater shore hardness than the remainder of the
material of which the spreading element is made. In order to
prevent further bellowing outwardly of the wall portion 51 when
pressure develops in the interior of the pressure chamber, and more
particularly to prevent such bellowing in the upper region near the
juncture with the portion 53, FIG. 11 shows that an additional
abutment 62 may be provided which prevents such displacement or
bellowing, so that only the lower portion of the wall portion 51
can belly out further in response to development of internal
pressure in the space 61, whereby the angle .alpha. varies
accordingly as is illustrated in the different Figures. By
decreasing the angle, making it smaller, the quantity of flowable
medium applied can be increased as to the quantity which is made to
pass through the applicator 5 or 5' onto the exposed surface of the
carrier 14. This variation of the angle can also be effected
continuously as discussed before.
The embodiments in FIGS. 8-14 provide for an increased flexibility
of adjustment as to the elasticity and stability of the spreading
element, over the embodiment of FIGS. 1-7. On the other hand, all
the advantages of embodiments of FIGS. 1-7 are also provided in the
embodiments of FIGS. 8-14.
It will be appreciated that it is immaterial whether it is the
conduit 2 which is moved so as to move the abutting element towards
and away from the exposed surface of the carrier 14, or whether for
instance the work table 17 on which the carrier 14 is disposed is
raised or lowered with respect to the conduit 2 and the spreading
element. Either possibility will achieve the purposes and
advantages which have been outlined with respect to such
adjustment, and means for carrying out such adjustment are known in
the art and require no detailed explanation to those conversant
with this field. What is essential for purposes of the present
invention is the mechanical adjustment by raising or lowering the
table 17 or by raising or lowering the conduit 2 carrying the
spreading element, and thereby the adjustment of the pressure of
the spreading element against the associated surface, in
combination with the variation in the cross-sectional configuration
of the setting element by varying the internal pressure, and also
the possibility of varying the elasticity and stability of the
spreading element by changing the internal pressure, without having
to shut down the apparatus, exchange components thereof, or the
like.
It will be understood that each of the elements described above, or
two or more together, may also find a useful application in other
types of constructions differing from the types described
above.
While the invention has been illustrated and described as embodied
in an apparatus for applying a flowable medium to a carrier, it is
not intended to be limited to the details shown, since various
modifications and structural changes may be made without departing
in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the
gist of the present invention that others can by applying current
knowledge readily adapt it for various applications without
omitting features that, from the standpoint of prior art, fairly
constitute essential characteristics of the generic or specific
aspects of this invention and, therefore, such adaptations should
and are intended to be comprehended within the meaning and range of
equivalence of the following claims.
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