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EP 0 190 846 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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10.10.1990 Bulletin 1990/41 |
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Date of filing: 23.01.1986 |
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International Patent Classification (IPC)5: B41F 17/00 |
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Multi-colour printing
Mehrfarbendruck
Impression polychrome
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Designated Contracting States: |
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DE FR IT |
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Priority: |
23.01.1985 GB 8501686
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Date of publication of application: |
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13.08.1986 Bulletin 1986/33 |
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Proprietor: Erich Netzsch GmbH & Co. Holding KG |
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D-95100 Selb (DE) |
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Inventor: |
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- Cartlidge, C.D.J.
Hanley
Stoke-on-Trent
Staffordshire (GB)
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Representative: Goetz, Rupert, Dipl.-Ing. et al |
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Wuesthoff & Wuesthoff
Patent- und Rechtsanwälte
Schweigerstrasse 2 81541 München 81541 München (DE) |
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References cited: :
EP-A- 136 759 US-A- 3 990 364
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US-A- 3 688 695
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| Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
|
[0001] This invention relates to multi-colour printing. The invention is especially, but
not exclusively, applicable to the printing of articles of ceramic ware but may be
used for printing other articles. The term "multi-colour" is used herein to refer
to the application of two or more colours.
[0002] Multi-colour printing of articles is effected by applying individual colours to the
article successively. For this to be effective it is essential that precise registration
is achieved between the successive printings otherwise the image will become distorted.
[0003] From US-A-399Q364 a multi-colour printing apparatus for use in the ceramic industry
has been known in which four screen units, each provided with a doctor, are horizontally
arranged in juxtaposition for applying four different colours of a multi-colour image.
Below the screen units a conveyor belt circulates in a vertical plane. Intermediate
carriers are arranged on this conveyor belt in such manner that they can be pivoted
through an angle of 90°. The intermediate carriers are equidistant from one another,
as are the screen units, and can be guided with precision under the screens. Below
the conveyor belt an article conveyor is also arranged in a vertical plane. The articles-plates-are
equidistantly arranged on this conveyor. On one side the article conveyor extends
beyond the conveyor belt for intermediate carriers so that a colour-receiving position
is provided for the articles wherein they are not covered by the intermediate carrier
conveyor belt and can be detained in this position. The conveyor belt can be stopped
for each intermediate carrier in a colour transfer position. The intermediate carriers
can be swung downwardly through 90° over the article which is in the colour-receiving
position. After this pivoting movement, a pressure pad driven by a driving mechanism
presses the intermediate carrier on to the article in order to transfer the colour
from the carrier to this article. The article conveyor moves through a drying kiln
in which the colour extract is caused to adhere firmly to the articles. The intermediate
carriers are pressed into engagement with successive ceramic articles at said printing
station to apply a different colour extract to each of said ceramic articles. This
is followed by the step of drying said ceramic articles after each of the different
colour extracts is applied to said ceramic articles. Subsequently, the ceramic articles
are sequentially returned to said printing station again and a different one of said
intermediate carriers is being pressed onto each individual ceramic article. This
procedure is being repeated until all colours have been applied to each individual
article. This causes substantial registration problems.
[0004] It is an object of the present invention to obviate or mitigate this disadvantage.
[0005] The invention provides multi-colour printing apparatus comprising a vertically movable
non-rotatable printing member, a support for ware to be decorated locatable in a position
beneath the printing member and a plurality of transfer members disposed angularly
around the central vertical axis of said printing member at a level between same and
said ware support, the transfer members being sequentially movable into positions
between said printing member and said ware support whereby to permit transfer of printed
images therefrom to said printing member for subsequent application to ware mounted
on said support.
[0006] Preferably said transfer members comprise generally flat plates on which is etched
or engraved a portion of the pattern or decoration to be applied to the articles of
ware, each transfer member being provided with doctor means and control means being
provided to effect doctoring of each plate during transfer to the ware of the image
from the preceding plate.
[0007] Preferably also said doctor means is operable following transfer of an image from
the associated plate to re-ink the plate in readiness for the next operating cycle.
For this purpose the doctor means preferably incorporates a doctor blade mounted for
pivotal movement between inking and doctoring positions and adapted for bodily movement
relative to the associated plate in both operative positions of the latter.
[0008] Preferably also each of said transfer members incorporates controllable heating means
operable to maintain the transfer member at a temperature which will ensure complete
transfer of heat sensitive inks from the transfer member to said printing member during
operation.
[0009] Preferably said ware support is mounted on a carriage arranged to be horizontally
movable between a decorating position disposed vertically beneath said printing member
and a loading and unloading position convenient to a machine operator. For this purpose
the ware support may be slidably movable in a direction radially of said printing
member in an angular direction intermediate the angular positions of adjacent ones
of said transfer members. The ware support preferably incorporates means for centring
ware mounted thereon and for securing the centred ware against movement during operation.
[0010] Preferably said printing member comprises a pad of deformable material such as silicone.
[0011] An embodiment of the invention will now be described, by way of example only, with
reference to the accompanying diagrammatic drawings, in which:
Fig. 1 is a sketch illustrating the general arrangement of the principal components
of a multi-colour printing apparatus according to the invention;
Fig. 2 is a vertical section through the apparatus showing one printing station;
Fig. 3 is an enlarged perspective view of a doctor mechanism incorporated in the apparatus;
Figs. 4A to 4D illustrate the sequence of operation of the doctor mechanism;
Fig. 5 is a vertical cross section through a transfer member incorporated in the apparatus;
Fig. 6 is an exploded perspective view showing the components of the transfer member
of Fig. 5;
Fig. 7 is a perspective view of a ware support incorporated in the apparatus; and
Figs. 8A to 8D illustrate the operation of the printing cycle.
[0012] Referring to Fig. 1 the apparatus incorporates a central vertically movable printing
member 10 in the form of a deformable silicone pad beneath which a ware support 11
is mounted. Four transfer members 12A to 12D are disposed angularly around the axis
of movement of the printing member 10 at a level between the printing member 10 and
the ware support 11 and are arranged to be slidably movable in turn into positions
between the printing member 10 and the ware support 11 whereby patterns printed on
each of the transfer members in different colours may be picked up by the printing
member 10 in turn and following withdrawal of the transfer member applied to ware
mounted on the support 11 by downward movement of the printing member.
[0013] Referring now to Fig. 2 the apparatus is shown in greater detail and comprises a
support frame 15 on which the printing member 10, ware support 11 and transfer members
12A to 12D are mounted. Only the transfer member 12A is shown in Fig. 2. The printing
pad 10 is carried by a rigid backing plate 16 having upwardly extending guides 17
slidably mounted in collars 18 fixed to the frame 15 of the machine. A hydraulic cylinder
19 is mounted above the pad 10 and between the guides 17 and has a piston rod 20 extending
through the frame 15 and connected to the mounting plate 16. The cylinder 19 may be
extended to move the pad 10 vertically downwards and retracted to withdraw it to the
position shown in Fig. 2. During such movement the pad 10 is stabilised by the guide
members 17 which also serve to prevent rotation of the pad. The pad is therefore constrained
so that it may move in a vertical direction only and cannot rotate or move horizontally.
An actuating member 21 mounted on one of the guides 17 is adapted to act on control
valves 22 mounted vertically adjacent the guide 17 to effect operation of related
parts of the equipment in the desired sequence during printing operations.
[0014] Each of the transfer members 12A to 12D comprises a carrier 25 supporting a generally
flat metal plate 26 on which the design or pattern to be applied to the articles to
be decorated is etched or engraved. The carrier 25 is slidably mounted on horizontal
rails 27 and is adapted to be moved by operation of a hydraulic cylinder 28 between
a retracted position shown in Fig. 2 and an extended position in which the transfer
member is located between the printing pad 10 and the ware support 11. A doctor mechanism
30 is associated with the plate 26 and is operative to apply ink thereto and to scrape
the plate so as to remove ink from the surface except in the areas of the etched or
engraved pattern. A similar transfer member and doctor assembly is provided at each
of the four locations 12A to 12D, all the plates 26 being engraved with portions of
the pattern and each having a different colour of printing ink applied thereto during
operation whereby successive colours are applied in sequence to appropriate regions
of the pattern during the printing operation.
[0015] The doctor mechanism 30 is shown in greater detail in Fig. 3 and comprises a support
or bridge member 31 extending across the path of horizontal movement of the engraved
plate 26 and supporting a horizontal shaft 32 rotatably mounted in support blocks
33 and movable between alternative positions of use by a rotary actuator 34. A blade
carrier 35 is mounted on the shaft 32 and carries a flexible doctor blade 36 of rubber
or similar material which acts on the surface of the engraved plate during operation.
Threaded adjustors 37 act between the bridge member 31 and support blocks 33 to provide
for adjustment of the blade 36 relative to the surface of the plate 26 on which it
acts.
[0016] The doctor mechanism 30 is arranged both to apply ink to the plate 26 and to scrape
or doctor it so as to remove the inkfrom the high points of the plate 26 but leave
it in the engraved or etched portions. The operation of the mechanism 30 is shown
in Figs. 4A to 4D. Fig. 4A shows the rest position of the unit in which the blade
36 is in an inclined position such that its free edge is spaced slightly above the
surface of the plate 26. The latter is adapted to be moved horizontally by means of
the hydraulic cylinder 28 referred to previously and the doctor mechanism 30 is connected
to a similar hydraulic cylinder 38 for movement parallel to the surface of the plate
26. In the position shown in Fig. 4A the cylinder 28 is retracted to maintain the
plate 26 in its retracted inking position and the cylinder 38 is extended to position
the doctor blade 36 in an outer position adjacent the outer end of the plate 26.
[0017] When actuated at the appropriate stage in the operating cycle the doctor blade 36
is first rotated into a vertical position in which it is pressed into close contact
with the surface of the engraved plate which has been previously coated with printing
ink. Cylinder 38 is then retracted to draw the blade 36 across the surface of the
plate 26 thereby removing ink from the high points of the surface but leaving ink
in the engraved recesses corresponding to selected areas of the pattern to be applied
to the articles being decorated. This position of the apparatus is shown in Fig. 4B.
Thereafter the cylinders 28 and 38 are simultaneously extended to move the plate 26
and scraper assembly to their extended positions in which the plate is disposed beneath
the printing pad 10. No relative movement takes place at this stage between the plate
26 and the scraper blade 36 and subsequently the printing ink is picked up from the
plate 26 by the printing member. Thereafter the blade 36 is moved to its inclined
position and cylinder 28 is retracted to draw the plate 26 into its retracted position
shown in Fig. 2. Relative movement thus takes place between the surface of the plate
26 and the blade 36 and since the latter is in its tilted position this serves to
spread a coating of printing ink introduced behind the blade 36 over the entire surface
of the plate 26. The apparatus is then in the position of Fig. 4A ready for the next
operating cycle.
[0018] Transfer of printed images from the plate 26 to the printing pad 10 and from the
latter to the surface of the ware to be decorated is dependent on the temperatures
of the surfaces in contact with the ink images at these different stages. In order
to ensure complete release of the printing ink from the engraved plate 26 the latter
requires to be maintained at a predetermined temperature. For this purpose the transfer
member incorporates heating means. Referring to Figs. 5 and 6 the engraved plate 26
is mounted in a tray 40 by means of a clamping plate 41 acted on by adjustment screws
42. A heating unit comprising a top plate 43, a heater 44, an insulating plate 45
and a bottom plate 46 is clamped beneath the tray 40 and a temperature sensitive probe
47 is connected to the heater 44 and to control means operable to maintain same at
a constant temperature dependent on readings from the probe. The entire assembly is
slidably mounted on the spaced parallel rails 27 along which it is horizontally movable
by operation of the cylinder 28.
[0019] The ware support 11 is shown in Fig. 2 and in greater detail in Fig. 7. It comprises
a carriage 50 incorporating a central mount 51 for articles of ware connected to a
vacuum source operable to retain ware in position once centred by centring arms 52.
The carriage 50 is mounted on a pair of spaced parallel rods 53 and is directly connected
to a hydraulic cylinder 54 for movement along the rods 53 by introduction of hydraulic
fluid to one or other end of the cylinder. Hydraulic dampers 55 are provided to arrest
movement of the carriage 50 at each end of its travel which takes place in a radial
direction relative to the vertical axis of the printing member 10 and at an angular
location between adjacent ones of the transfer members 12. In its inner or printing
position the ware support 11 is disposed in vertical alignment with the printing member
10. In its outer or loading position the ware support 11 is readily accessible to
an operator or to automatic loading and unloading apparatus.
[0020] Figs. 8A to 8D diagramatically illustrate the printing operation. In Fig. 8Athe printing
member 10 is shown in its raised position and one of the transfer members 12 has been
located between the printing member and an article 60 to be decorated supported on
the ware support 11. The printing member 10 is then moved vertically downwards as
shown in Fig. 8B into contact with the plate 26 from which it picks up the printing
ink retained in the engraved portions of the plate. The printing member 10 is then
raised clear of the transfer member 12 which is withdrawn to its retracted position
leaving the printing member disposed vertically above the article 60 as shown in Fig.
8C. The printing member 10 is then moved vertically downwards into contact with the
surface of the article 60 to transfer the printed image thereto. Thereafter the printing
member 10 is withdrawn to its uppermost position and the next transfer member 12 is
moved into the position shown in Fig. 8A, following which the sequence is repeated.
In the embodiment four cycles are carried out to effect complete printing but this
could of course vary depending on the number of colours concerned.
[0021] Operation of the doctor mechanism 30 is synchronized with the printing operations
in order that when one colour image is being printed onto the article 60 of ware the
next engraved plate 26 is being doctored. Thus in operation with all four engraved
plates 26 in their retracted positions and the printing member 10 elevated, three
of the plates 26 will be in an inked but not doctored condition, the first plate to
come into operation will be inked and doctored and the ware support 11 will be in
its retracted position accessible to an operator. The operator places an article 60
on the ware support 11, following which the centring arms 52 act to centre the article
60 and suction is applied to retain it in position. The cylinder 54 is then energised
to move the ware support 11 to its extended position in which it is disposed vertically
beneath the printing member 10.
[0022] The first engraved plate 26 which has been previously doctored is then moved to its
extended position beneath the printing member 10 by operation of its cylinder 28.
The printing member 10 is then moved downwardly into contact with the engraved plate
26 to pick up the inked image and is raised again to its uppermost position. Plate
26 is then withdrawn to its retracted position and the printing member 10 is moved
vertically downwards into contact with the surface of the article 60 to be decorated
thereby transferring the first coloured image to the article. Simultaneously the doctor
mechanism 30 on transfer member 12B is actuated to doctor the associated engraved
plate 26 leaving the printing ink in the engraved image only. Once the printing member
10 reaches its uppermost position the second engraved plate 26 carried by transfer
member 12B is moved to its extended position beneath the printing member 10 and the
latter is moved downwardly to pick up the inked image from the plate 26. Following
withdrawal of the engraved plate 26 the printing member 10 is moved vertically downwards
to transfer the second image to the surface of the article 60 on the ware support
11. During this operation the third engraved plate 26 is doctored and the sequence
continues until all four colour images have been transferred to the article 60 of
ware. The ware support 11 is then moved to its retracted position and the operator
removes the decorated article and replaces it with a further article following which
the operation is repeated.
[0023] By virtue of the arrangement described multi-colour decorating of articles may be
carried out extremely rapidly and accurately. Because the printing member 10 and the
article 60 to be decorated remain horizontally fixed relative to one another throughout
the decorating operation registration problems are substantially eliminated. Moreover
by arrangement of the transfer members 12A to 12D for the different components of
the pattern in radial positions around the central printing member 10 and by providing
separate doctor mechanisms 30 for each unit, one image can be doctored while the other
is printing thereby enabling particularly rapid operation. Moreover only a single
printing member is employed regardless of the number of colours to be applied.
[0024] Various modifications may be made without departing from the invention. For example
the transfer member need not be an engraved or etched plate but could be a substrate
to which the design or pattern is applied by screen printing. Means could be incorporated
for temperature control of the printing member and/or ware support in addition to
the transfer member if required. Alternative forms of doctor assembly may also be
employed and while in the embodiment the machine is designed to apply four colours,
any desired number of colours may be applied by increasing the number of transfer
members arranged radially around the printing member. Moreover while reference has
been made primarily to the printing of articles of ceramic ware the invention may
be applied to the printing of a wide variety of other articles.
1. Multi-colour printing apparatus comprising a vertically movable non-rotatable printing
member (10) a support (11) for ware (60) to be decorated locatable in a position beneath
the printing member (10) and a plurality of transfer members (12) which are sequentially
movable into positions between said printing member (10) and said ware support, characterized
in that the transfer members (12) are disposed angularly around the central vertical
axis of said printing member (10) at a level between same and said ware support (11),
whereby to permit transfer of printed images therefrom to said printing member (10)
for subsequent application to ware (60) mounted on said support.
2. Multi-colour printing apparatus according to claim 1 characterized in that said
transfer members (12) comprise generally flat plates (26) on which is etched or engraved
a portion of the pattern or decoration to be applied to the articles (60) of ware,
each transfer member (12) being provided with doctor means (36) and control means
being provided to effect doctoring of each plate (26) during transfer to the ware
of the image from the preceding plate.
3. Multi-colour printing apparatus according to claim 2 characterized in that said
doctor means (36) is operable following transfer of an image from the associated plate
(26) to re-ink the plate (26) in readiness for the next operating cycle.
4. Multi-colour printing apparatus according to claim 3 characterized in that said
doctor means incorporates a doctor blade (36) mounted for pivotal movement between
inking and doctoring positions and adapted for bodily movement relative to the associated
plate (26) in both operative positions of the latter.
5. Multi-colour printing apparatus according to any preceding claim characterized
in that each of said transfer members (26) incorporates controllable heating means
(44) operable to maintain the transfer member (12) at a temperature which will ensure
complete transfer of heat sensitive inks from the transfer member (12) to said printing
member (10) during operation.
6. Multi-colour printing apparatus according to any preceding claim characterized
in that said ware support (11) is mounted on a carriage (50) arranged to be horizontally
movable between a decorating position disposed vertically beneath said printing member
(10) and a loading and unloading position convenient to a machine operator.
7. Multi-colour printing apparatus according to claim 6 characterized in that said
ware support (11) is slidably movable in a direction radially of said printing member
(10) in an angular direction intermediate the angular positions of adjacent ones of
said transfer members (12).
8. Multi-colour printing apparatus according to any preceding claim characterized
in that said ware support (11) incorporates means (52) for centring ware mounted thereon
and for securing the centred ware against movement during operation.
9. Multi-colour printing apparatus according to any preceding claim characterized
in that said printing member comprises a pad (10) of deformable material.
10. A method of multi-colour printing of articles by sequentially applying to the
article (60) a plurality of images in different colours to make up the final pattern
or decoration characterised by maintaining the article in a fixed stationary position
while applying the different colours, each image for printing being introduced from
a different angular position to a centrally disposed, vertically movable and non-rotatable
printing member (10).
11. A method of multi-colour printing according to claim 10 characterized in that
each successive coloured image is being prepared during printing of the preceding
image.
1. Mehrfarbendruckvorrichtung mit einem senkrecht bewegbaren, nicht drehbaren Druckglied
(10), einer in eine Stellung unterhalb des Druckgliedes (10) bringbaren Unterlage
(11) für zu dekorierende Ware (60) und mehreren Übertragungsgliedern (12), die nacheinander
in 'Stellungen zwischen dem Druckglied (10) und der genannten Warenunterlage bewegbar
sind, dadurch gekennzeichnet, daß die Übertragungsglieder (12) in Winkelabständen
um die zentrale senkrechte Achse des genannten Druckgliedes (10) in einer Höhe zwischen
diesem und der genannten Warenunterlage (11) angeordnet sind, wodurch gedruckte Bilder
von den Übertragungsgliedern auf das genannte Druckglied (10) übertragbar sind, um
anschließend auf die Ware (60) aufgebracht zu werden, die auf der genannten Unterlage
angeordnet ist.
2. Mehrfarbendruckvorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die genannten
Übertragungsglieder (12) im wesentlichen flache Platten (26) aufweisen, in die ein
Teil des auf die Artikel (60) der Ware aufzutragenden Musters oder Dekors eingeätzt
oder eingraviert ist, wobei jedem Übertragungsglied (12) eine Rakelvorrichtung (36)
zugeordnet ist und Steuervorrichtungen vorgesehen sind, um das Rakeln jeder Platte
(12) während der Übertragung des Bildes von der vorangehenden Platte auf die Ware
zu bewirken.
3. Mehrfarbendruckvorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß die Rakelvorrichtung
(36) im Anschluß an die Übertragung eines Bildes von der zugehörigen Platte (26) betätigbar
ist, um die Platte (26) zur Vorbereitung des nächsten Arbeitszyklus wieder einzufärben.
4. Mehrfarbendruckvorrichtung nach Anspruch 3, dadurch gekennzeichnet, daß die Rakelvorrichtung
eine Rakel (36) aufweist, die zwischen Färbe- und Rakelstellungen hin- und herschwenkbar
angeordnet und zu Eigenbewegungen in bezug auf die zugehörige Platte (26) in deren
beiden Betriebsstellungen befähigt ist.
5. Mehrfarbendruckvorrichtung nach einem beliebigen vorangehenden Anspruch, dadurch
gekennzeichnet, daß jedes der genannten Übertragungsglieder (12) eine regelbare Heizvorrichtung
(44) aufweist, mit der sich das Übertragungsglied (12) auf einer Temperatur halten
läßt, welche eine vollständige Übertragung wärmeempfindlicher Farben vom Übertragungsglied
(12) auf das genannte Druckglied (10) im Betrieb gewährleistet.
6. Mehrfarbendruckvorrichtung nach einem beliebigen vorangehenden Anspruch, dadurch
gekennzeichnet, daß die Warenunterlage (11) auf einem Schlitten (50) befestigt ist,
der waagerecht zwischen einer senkrecht unter dem genannten Druckglied (10) angeordneten
Dekorierstellung und einer für einen Maschinenbenutzer angenehmen Lade- und Entladestellung
bewegbar ist.
7. Mehrfarbendruckvorrichtung nach Anspruch 6, dadurch gekennzeichnet, daß die genannte
Warenunterlage (11) in einer bezüglich des genannten Druckgliedes (10) radialen Richtung
in einem Winkel zwischen den Winkelstellungen benachbarter Übertragungsglieder (12)
verschiebbar ist.
8. Mehrfarbendruckvorrichtung nach einem beliebigen vorangehenden Anspruch, dadurch
gekennzeichnet, daß die Warenunterlage (11) eine Vorrichtung (52) zum Zentrieren der
auf ihr angeordneten Ware und zum Sichern der Ware gegen Bewegungen während des Betriebes
aufweist.
9. Mehrfarbendruckvorrichtung nach einem beliebigen vorangehenden Anspruch, dadurch
gekennzeichnet, daß das Druckglied ein Kissen (10) aus verformbaren Werkstoff aufweist.
10. Verfahren zum mehrfarbigen Bedrucken von Artikeln durch aufeinanderfolgendes Aufbringen
mehrerer Bilder in verschiedenen Farben auf den Artikel (60), aus denen sich das endgültige
Muster oder Dekor ergibt, dadurch gekennzeichnet, daß der Artikel in einer festgelegten
Ruhestellung gehalten wird, während die verschiedenen Farben auf ihn aufgebracht werden,
wobei jedes Druckbild aus einer unterschiedlichen Winkelstellung auf ein zentral angeordnetes,
senkrecht bewegbares und nichtdrehbares Druckglied (10) übertragen wird.
11. Mehrfarbendruckverfahren nach Anspruch 10, dadurch gekennzeichnet, daß jedes der
aufeinanderfolgenden Farbbilder während des Aufdruckens des vorangehenden Bildes vorbereitet
wird.
1. Machine pour l'impression polychrome, comprenant un élément imprimant (10) non
rotatif, mobile dans la direction verticale, un support (11) pour l'article à décorer
(60), qui peut être placé dans une position située sous l'élément imprimant (10),
et une pluralité d'éléments de transfert (12) qui peuvent être séquentiellement amenés
dans des positions situées entre ledit élément imprimant (10) et ledit support d'article,
caractérisée en ce que les éléments de transfert (12) sont disposés angulairement
autour de l'axe vertical central dudit élément imprimant (10), à un niveau situé entre
cet élément et ledit support d'article (11) pour permettre de cette façon le transfert
des images imprimées de ces éléments de transfert audit élément imprimant (10) pour
qu'elles soient ensuite appliquées à l'article (60) monté sur ledit support.
2. Machine pour l'impression polychrome selon la revendication 1, caractérisée en
ce que lesdits éléments de transfert (12) comprennent des plaques (26) de forme générale
plate, sur lesquelles est gravée ou creusée une portion du motif ou de la décoration
qu'il s'agit d'appliquer sur les articles (60), chaque élément de transfert (12) étant
muni de moyens racleurs (36), et des moyens de commande étant prévus pour effectuer
le raclage de chaque plaque (26) pendant que l'image est transférée de la plaque précédente
à l'article.
3. Machine d'impression polychrome selon la revendication 2, caractérisée en ce que
lesdits moyens racleurs (36) entrent en action après le transfert d'une image de la
plaque (26) correspondante pour réencrer la plaque (26) en préparation du cycle de
fonctionnement suivant.
4. Machine d'impression polychrome selon la revendication 3, caractérisée en ce que
lesdits moyens racleurs comprennent une lame racleuse (36) montée pour décrire un
mouvement de pivotement entre des positions d'encrage et de raclage et adaptée pour
décrire un mouvement d'ensemble par rapport à la plaque (26) correspondante dans les
deux positions de travail de cette dernière.
5. Machine d'impression polychrome selon une quelconque des revendications précédentes,
caractérisée en ce que chacun des éléments de transfert (26) comprend des moyens de
chauffage réglables (44) qu'on peut mettre en action pour maintenir l'élément de transfert
(12) à une température qui garantira le transfert total des encres sensibles à la
chaleur de l'élément de transfert (12) audit élément imprimant (10) pendant le fonctionnement.
6. Machine d'impression polychrome selon une quelconque des revendications précédentes,
caractérisée en ce que ledit support d'article (11) est monté sur un chariot (50)
agencé pour pouvoir se déplacer horizontalement entre une position de décoration disposée
à la verticale au-dessous dudit élément imprimant (10) et une position de chargement
et de déchargement qui est commode pour l'opérateur de la machine.
7. Machine d'impression polychrome selon la revendication 6, caractérisée en ce que
ledit support d'article (11) peut se déplacer en coulissement dans une direction radiale
par rapport audit élément imprimant (10), dans une direction angulaire intermédiaire
entre les positions angulaires des éléments de transfert (12) adjacents.
8. Machine d'impression polychrome selon une quelconque des revendications précédentes,
caractérisée en ce que ledit support d'article (11) comprend des moyens (52) pour
centrer l'article monté sur ces moyens et pour fixer l'article centré en l'empêchant
de se déplacer pendant le fonctionnement.
9. Machine d'impression polychrome selon une quelconque des revendications précédentes,
caractérisée en ce que ledit élément imprimant comprend un tampon (10) de matière
déformable.
10. Procédé d'impression polychrome d'articles dans lequel on dépose successivement
sur l'article (60) une pluralité d'images en différentes couleurs de façon à composer
le motif final ou la décoration finale, caractérisé en ce qu'on maintient l'article
dans une position stationnaire fixe pendant l'application des différentes couleurs,
chaque image à imprimer étant introduite, en provenance d'une position angulaire différente,
sur un élément imprimant disposé en position centrale, mobile dans la direction verticale
et non rotatif.
11. Procédé d'impression polychrome selon la revendication 10, caractérisé en ce que
chacune des images en couleurs successives est préparée pendant l'impression de l'image
précédente.