DE1815981A1 - Device on the printing base of screen printing machines - Google Patents

Description

Schnellpressenfabrik Prankenthal Albert & Cie AG ₁ Frankenthal

Device on the printing base of screen printing machines

The invention relates to a device on the printing substrate of screen printing machines, with which a better Keeping the object to be printed on the print

target
underlay can be achieved / In particular if the object to be printed is plate-shaped, as is the case, for example, with plastic printed circuit boards with an electrical circuit diagram, e.g. If the pail is 3 mm thick, it may happen that the plate is not completely flat but slightly curved. If such a plate is inserted into the dowel pins of the printing pad in the usual way, even a strong suction force on the underside of the perforated printing pad cannot hold the sheet in place with certainty, because the rigidity of the sheet material, especially in the curvature, does not have a sufficient suction effect only comes up.

To solve the problem mentioned, the invention

. in a hole,., ..,, "

It is suggested that the switching head of a switching contact & «3? f» E »äg * should be placed on a perforated printing pad, by means of which a suction device is activated when the object to be printed is pressed onto the printing pad named object - which is preferably framed by a mask that covers the suction holes located next to it - sucks firmly on the printing surface and is switched off again by a limit switch after the printing process is complete, which at the same time _{lifts the ejector fingers or 0} -pins through the printing incursion to lift the now printed Subject.

The invention requires, instead of a mere powerless placing of the object to be printed on the printing substrate a push on »This push is an indirect button push and has two effects at the same time: expressing the arching of the plate and thus that

009827/0079

BAD OWGiNAL

Leveling the plate on the one hand and the simultaneous switching on of the induced draft on the other hand, which is now fully for Effect comes because the underside of the plate is flat and with it rests fully on the print surface. The induced draft can now the internal tension force of the plate, which their Bulging is deprived, counteract it and prevent it from bulging again. This is especially true when increasing the suction force, the plate to be printed is framed by a mask covering the suction holes located next to it is. This mask has the same thickness as the plate to be printed, e.g. ebeMails 3 mm, so that your The top is flush with that of the plate, which protects the squeegee and the stencil screen. »The audible switch-on the induced draft is for the operator at the same time the confirmation of their correct handling.

At the end of the printing process, the induced draft is switched off again depending on the path by a limit switch With this, ejector fingers or pins are coupled, expediently electrically, which are lifted up by the printing pad are used to lift or lift the now printed object. This is his acceptance of the printing material light and comfortable even in spite of the embedding in the mask recess. The change of the printed copies can without difficulty and quickly ».

An embodiment of the invention is shown in the drawing shown schematically. It shows

to

Pig. 1 is a plan view of the / printing plate, Pig, FIG. 2 is a cross-section,

Pigο 3 the limit switch.

On the underside of the printing pad 1 sits an »electrical switch 2, the switch button 2 ^{1 of} which protrudes through a hole in the printing pad 1 above the surface of the pad so that its upper edge is flush with the top of the printing pad after a switching stroke has been carried out. The plate 3 to be printed is hung on dowel pins 8 and pressed onto the printing substrate; a Saageinriohtimg is switched on via the switch button 2 · and the switch 2, which is effective on the underside of the printing supports 1 through a group of suction holes 9

ü Ü 9 8 2 7/0 0 7 9

as long as the holes 9 are not covered by a mask 7 on the top of the printing substrate 1. The mask 7 has a frame cutout for the plate 3 to be printed and has the same wall thickness as this _t as can be seen in FIG.

The suction device is switched off at the end of the printing process by a cam 4 connected to the screen printing frame on the electrical switch 5 as Limit switch. With this switching process, two ejector fingers 6 are at the same time through corresponding holes in the Printing pad 1 lifted and thus in turn lift the printed plate 1 from its printing pad 1 from the Frame of the mask 7. The printed copy can thus be removed easily and quickly. The operation of the ejector fingers 6 can be done mechanically or electromagnetically or in some other way.

Instead of the conventional push button 2 'shown in the drawing as an example of the switch head a switch 2 can be other actuators or facilities are used, ZcB. those with magnetic or electronic »atex auxiliary means or work with compressed air.

009827/00 79

BATH ORIGINAL

Claims (1)

Claim Device on the printing underlay of screen printing machines, , ■■, ■,. -, j_ -, in a hole ■, -, ..-,. characterized in that aas / a perforated printing pad ( ¹ ) the switch head (2 1) of a switch (2) S «KxftXXagi> by which a suction device is activated when the object (3) to be printed, in particular the plate-shaped object (3) to be printed, is activated on the printing unit (1), the said object (3) - preferably from one of the suction holes ( 9) covering mask (7) is framed - sucked onto the printing pad (1) and switched off again by a limit switch (4 »5) at the end of the printing process, with which at the same time ejector _{fingers or 0} pins (6) through the printing pad (1) are lifted to lift the now printed object (3). 009827/0079 _ΟΛΛ ^BATH ORIGINAL