FR2743331A1

FR2743331A1 - Squeegee-less printing plate inker

Info

Publication number: FR2743331A1
Application number: FR9600097A
Authority: FR
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-01-05
Filing date: 1996-01-05
Publication date: 1997-07-11

Abstract

The inker consists of an ink reservoir (3) with ink maintained at a pressure against the rear face of a movable printing plate (5). The printing plate is located in an extension (2) incorporating a compression cavity (4) which retains an ink layer. The printing plate is perforated with fine holes which do not allow ink to pass through when static. The ink is forced through the holes by a transitory dynamic pressure applied to the ink layer by a pressure pad. The inker also has systems for creating a dynamic pressure, preventing the return of ink to the reservoir while the pressure is applied and absorbing and restoring the ink volume displaced by the pressure. The pressure is created by a piston, and the printing plate is reinforced by supporting bars (12). The ink volume is absorbed and restored by an elastic membrane.

Description

Encrage de clichés d'impression sans racolage.Ink printing plates without solicitation.

""""e le domaine de I'impression se rapportant
L'invention concerne le domaine de l'impression se rapportant à l'encrage de clichés gravés en creux, et l'encrage de clichés en forme d'écrans maillés."""" e the field of printing relating
The invention relates to the field of printing relating to the inking of intaglio shots, and the inking of clichés in the form of mesh screens.

Le but de la présente invention est d'obtenir un encrage des clichés sans raclage.The object of the present invention is to obtain an inking of the plates without scraping.

On atteint ce but en supprimant l'étalement de l'encre sur le cliché, ce qui entraine la suppression de la racle, et donc entraine la suppression de l'usure de la racle et du cliché.This goal is achieved by eliminating the spreading of the ink on the plate, which causes the removal of the doctor blade, and therefore results in the elimination of the wear of the doctor blade and the plate.

Un autre but vise à obtenir les qualités de la sérigraphie et de la tampographie sans leurs défauts.Another aim is to obtain the qualities of screen printing and pad printing without their faults.

Les défauts de la sérigraphie sont le raclage du cliché et l'étalement de l'encre à l'air libre favorisant l'évaporation des solvants rendant instable la viscosité de l'encre.The defects of the screen printing are the scraping of the plate and the spreading of the ink in the open air favoring the evaporation of the solvents making unstable the viscosity of the ink.

Les défauts de la tampographie sont le raclage du cliché et la nécessité d'une encre plus fluide pour remplir la gravure, fluidité entrainant une moindre opacité des couleurs, et donc un marquage moins couvrant.The defects of pad printing are the scraping of the plate and the need for a more fluid ink to fill the engraving, fluidity resulting in less opacity of the colors, and therefore a less covering marking.

Plus précisément, l'invention est exposée à l'aide de dessins décrits chronologiquement.More specifically, the invention is explained using drawings described chronologically.

La figure 1 est une vue de dessus schématique, incluant deux écorchés, d'un encrier fermé. Celui-ci comprend: - une plaque frontale rigide 1; - un bloc de raccordement 2 permettant le fonctionnement horizontal ou vertical de l'encrier; - un réservoir d'encre 3 vissé dans le bloc, et un bouchon 4 fermant l'autre entrée. La plaque frontale t comprend une extension 5 incluant une large rainure sur sa face postérieure pour former un conduit 6 écoulant l'encre dans une cavité plate 7, dont le fond comprend une membrane élastique 8 soutenue par une plaque arrière rigide 9 percée uniformément d'alvéoles 10.Une variante de clichés (11, 12) ferme la cavité 7 et coulisse sur des colonnes 13, dont chacune est taraudée pour le blocage d'une tête de vis 14 limitant la remontée du cliché, et fixant une butée à tenue élastique telle qu'une lame-ressort 14' pliée à l'équerre pour être en appui sur la plaque frontale 1. Le cliché peut être conçu dans un matériau compact traversé de mini-trous 15, dont la gravure creuse résulterait d'un pochoir. Autrement, ce peut être un écran de sérigraphie comprenant une toile 11 et une monture 12 incluant des tiges formant des saillies 16 pour limiter la pression d'un tampon d'impression sur le cliché. A travers la plaque frontale 1 est engagé un clapet anti-retour formé d'une plaquette rigide 17 suspendue à un étrier étirable 18, en une matière tel que du caoutchouc, pour obturer le conduit 6.Le sommet du réservoir comprend un bouchon, en une matière tel que du caoutchouc, incluant un trou pincé 19 permettant l'engagement du tuyau d'un goutte-à-goutte.Figure 1 is a schematic top view, including two cutaway views, of a closed inkwell. This includes: - a rigid front plate 1; - a connection block 2 allowing the horizontal or vertical operation of the inkwell; - an ink tank 3 screwed into the block, and a cap 4 closing the other inlet. The front plate t comprises an extension 5 including a wide groove on its rear face to form a conduit 6 flowing the ink into a flat cavity 7, the bottom of which comprises an elastic membrane 8 supported by a rigid rear plate 9 pierced uniformly with cells 10. A variant of plates (11, 12) closes the cavity 7 and slides on columns 13, each of which is tapped for blocking a screw head 14 limiting the ascent of the plate, and fixing a stop with elastic hold such as a leaf spring 14 'folded at right angles to bear on the front plate 1. The plate can be designed in a compact material crossed by mini-holes 15, the hollow engraving of which would result from a stencil. Otherwise, it may be a screen printing screen comprising a canvas 11 and a frame 12 including rods forming protrusions 16 to limit the pressure of a printing pad on the plate. Through the front plate 1 is engaged a non-return valve formed of a rigid plate 17 suspended from a stretchable stirrup 18, made of a material such as rubber, to close the conduit 6. The top of the tank comprises a plug, in a material such as rubber, including a pinched hole 19 allowing the engagement of the pipe of a drip.

La figure 2 est une vue schématique, en coupe longitudinale, montrant le percement de la plaque frontale 1 pour le passage du clapet comprenant la plaquette 17 suspendue à l'étrier en caoutchouc 18. La membrane 8 est étendue pour couvrir les alvéoles 10, et pour former un joint d'étanchéité entre la plaque frontale 1 et la plaque dorsale 9 réunies par des boulons 20. Un anneau 21 tend et bloque la toile 11 dans une rainure 22 à la périphérie de la monture 12 soutenue par un joint élastique 23 et par les lames-ressort 14'. La rigidité de l'appui de ces lames est annulée par un basculement ou un fléchissement réalisé par l'augmentation de pression sur le cliché 11 à la fin de l'aplatissement d'un tampon d'impression.Dès la rupture de la rigidité d'appui, le joint 23 est surcomprimé et le cliché s'enfonce dans l'extension 5 de l'encrier pour créer une surpression transitoire contrôlée par le clapet 17 et ajustée par la membrane élastique 8, de raideur adaptée, cloquant dans les alvéoles 10. Ces cloques absorbent le volume d'encre déplacé par la pression dynamique, et le restituent dès que le tampon se retire pour rétablir une pression statique. La membrane peut être monobloc, ou composée de deux membranes plus fines et simplement supperposées, dont celle du dessus serait en une matière telle que celle du tampon, ou en un élastomère fluorocarboné "TéFLON" résistant aux solvants de l'encre, et dont celle du dessous serait en un caoutchouc tel que du latex résistant aux déchirures.FIG. 2 is a schematic view, in longitudinal section, showing the drilling of the front plate 1 for the passage of the valve comprising the plate 17 suspended from the rubber stirrup 18. The membrane 8 is extended to cover the cells 10, and to form a seal between the front plate 1 and the back plate 9 joined by bolts 20. A ring 21 tightens and blocks the fabric 11 in a groove 22 at the periphery of the frame 12 supported by an elastic seal 23 and by the leaf spring 14 '. The rigidity of the support of these blades is canceled out by a tilting or deflection produced by the increase in pressure on the plate 11 at the end of the flattening of a printing pad. support, the seal 23 is supercharged and the plate is inserted into the extension 5 of the inkwell to create a transient overpressure controlled by the valve 17 and adjusted by the elastic membrane 8, of suitable stiffness, blistering in the cells 10 These blisters absorb the volume of ink displaced by the dynamic pressure, and restore it as soon as the pad is withdrawn to restore static pressure. The membrane may be in one piece, or composed of two thinner and simply supperposed membranes, the upper one of which would be made of a material such as that of the pad, or a "TéFLON" fluorocarbon elastomer resistant to ink solvents, and of which that from below would be rubber such as tear-resistant latex.

Après l'utilisation de l'encrier, le cliché peut être protégé par un couvercle l'isolant de l'air libre.After using the inkwell, the plate can be protected by a cover insulating it from the open air.

La figure 3 est une vue d'ensemble, schématique, représentant un dispositif de tampographie. L'encrier, avec son réservoir amovible 3, son extension 5, un cliché 11, ses butées 16, son clapet 17, est positionné derrière un porte-objet. Dans l'exemple, ce porte-objet est un plateau révolver 24 à indexations, comprenant des ruptures de continuité telles que des ouvertures 25. Ce dispositif permet un simple mouvement alternatif du tampon 26, sans déplacement de l'encrier. Par une rotation pas à pas du plateau, une ouverture 25 et un objet 27 se positionne successivement pour un aplatissement du tampon sur le cliché 11, et ensuite sur l'objet 27. La monture 28 du tampon comprend des saillies 29 pour une commande positive de fermeture du clapet 17 qui est poussé lors de l'aplatissement du tampon sur le cliché par l'action du piston 30.Figure 3 is an overview, schematic, showing a pad printing device. The inkwell, with its removable reservoir 3, its extension 5, a plate 11, its stops 16, its valve 17, is positioned behind an object holder. In the example, this object-holder is a revolver plate 24 with indexing, comprising breaks in continuity such as openings 25. This device allows a simple reciprocating movement of the pad 26, without displacement of the inkwell. By a step-by-step rotation of the plate, an opening 25 and an object 27 are successively positioned for a flattening of the stamp on the plate 11, and then on the object 27. The frame 28 of the stamp comprises projections 29 for positive control for closing the valve 17 which is pushed during the flattening of the buffer on the plate by the action of the piston 30.

Ce dispositif de tampographie peut comprendre un pressostat déclenchant les retraits du piston transportant le tampon d'impression fixé sur sa monture débordante.This pad printing device may include a pressure switch triggering the withdrawals of the piston transporting the printing pad fixed on its projecting mount.

La figure 4 est un détail du clapet anti-retour comprenant la plaquette rigide 17 et l'étrier en caoutchouc 18 traversant la plaque frontale 1. La plaquette comprend des lames-ressort en saillies 31 pour l'enfoncement du clapet dans le conduit 6 par des saillies 29 de la monture 28 du tampon 26.FIG. 4 is a detail of the non-return valve comprising the rigid plate 17 and the rubber stirrup 18 passing through the front plate 1. The plate comprises protruding leaf springs 31 for the insertion of the valve into the conduit 6 by protrusions 29 of the frame 28 of the buffer 26.

La figure 5 est un détail d'un dispositif de goutte-à-goutte.Figure 5 is a detail of a drip device.

Ce dispositif comprend: - un réservoir 32; - un bouchon élastique incluant un trou pincé 19 pour l'introduction d'une aiguille de seringue dans le réservoir, et la mise à la pression atmosphérique de l'intérieur du réservoir; - un tuyau 33 formé en un siphon solidaire du réservoir par une bague de serrage élastique 34. Le débit du siphon est limité par un petit tube capillaire 35 engagé à force dans l'extrémité plongeante du tuyau 33. Ce goutte-à-goutte peut donc être accouplé au réservoir d'encre 3 en introduisant le tuyau 33 par le trou pincé 19 du bouchon. This device comprises: - a reservoir 32; - An elastic stopper including a pinched hole 19 for the introduction of a syringe needle into the reservoir, and bringing the interior of the reservoir to atmospheric pressure; - A pipe 33 formed in a siphon secured to the reservoir by an elastic clamping ring 34. The flow rate of the siphon is limited by a small capillary tube 35 engaged by force in the plunging end of the pipe 33. This drip can therefore be coupled to the ink tank 3 by introducing the pipe 33 through the pinched hole 19 of the cap.

Claims

Claims:

1 - Device for inking printing plates characterized by an inkwell comprising: - a reservoir (3) whose ink reserve maintains an ink pressure on the internal face of a removable plate (11) located in a extension (5) including a cavity (7) retaining a sheet of ink, the plate being crossed by mini-holes (15) not allowing static passage of the ink, this passage being effected during a pressure transient dynamics creating an effective overpressure on the ink sheet at the end of the flattening of a printing pad (26) on the etching of said plate, and means: - for creating dynamic pressure; - to prevent the ink from returning to the reservoir during overpressure; - to adjust the overpressure; - to absorb and restore a volume of ink displaced during overpressure; - for the efficiency of the overpressure; - for adding solvents to the ink; - To limit the pressure of the stamp on the plate integral with the inkwell which can be in a fixed position, vertically, horizontally, behind an object holder (24) including breaks in continuity such as openings (25).

2 - Device according to claim 1, characterized in that the mini-holes (15) are delimited by a stencil forming the engraving.

3 - Device according to claim 1, characterized in that the means creating the dynamic pressure is a piston (30) acting for the elastic depression of the extension (5).

4 - Device according to claim 1, characterized in that the non-return means of the ink in the reservoir, is a valve (17, 18) with positive control.

5 - Device according to claim 1, characterized in that the means adjusting the overpressure is an elastic means (8) disposed at the rear of the ink sheet and the plate.

6 - Device according to claims 1 and 5, characterized in that the means absorbing and restoring a displaced ink volume, comprises an elastic membrane (8) bearing on the honeycomb surface of a support (9, 10).

7 - Device according to claim 6, characterized in that the membrane (8) comprises a treatment such as fluorocarbon to constitute a resistance to contact with the ink.

8 - Device according to claim 1, characterized in that the reservoir (3) is removable by its attachment to a block (2) connecting to the extension (5).

9 - Device according to claim 1, characterized in that the means of effectiveness of the overpressure comprises stops with elastic hold, such as leaf springs (14 ') bending at the end of the flattening of the buffer (26 ).

10 - Device according to claim 1, characterized in that the limitation of the pressure of the buffer (26) on the plate (11) is achieved by the frame (28) of the buffer abutting on projections (16) of the plate.