DE9318612U1 - Pad printing machine - Google Patents

Description

TELEF0N:0711/784731 T E L E F £X &uacgr;&Ogr;&Lgr; J 1 / 7 6fc Cf9 9&&idiag; E CE &KHgr;.:&Iacgr; 7 7 1 1 1 O 4 O &rgr; a s b

KOHLER SCHMID + PARTNER '

PATENT ATTORNEYS

KÖHLER SCHHID + P. RUPPHANNSTR. 27 D-70565 STUTTGART

20 301 Si/nu

Morlock Mechanik GmbH & Co. KG Ruhesteinstr. 349 72270 Baiersbronn

Pad printing machine

The invention relates to a pad printing machine with at least one bottomless hollow body as an inking and doctoring device and with a pressing device supported on the hollow body for pressing the hollow body onto a cliché, the hollow body being guided on the pressing device.

In pad printing machines of this type, edges on the edges of the bottomless hollow bodies facing the clichés are used to scrape off excess ink from the inked cliché surfaces. In order to achieve a sufficient scraping effect of the edges of the hollow body, the hollow body and cliché must be pressed against each other during their relative movement. When using clichés that have uneven surfaces, the squeegee edge of the hollow body must be able to move in a direction perpendicular to the cliché surface.

For this reason, special designs of hollow bodies are used on known pad printing machines, which are made up of several parts and whose parts sliding on the plate surface are flexible and/or twistable. Conventional squeegee edges that are rigidly connected to the base of the hollow body cannot be used on the known printing machines in conjunction with uneven plates.

The invention is based on the object of creating a pad printing machine on which excess ink on the surface of the plate can be effectively and cleanly scraped off even when using uneven plates with conventional hollow bodies.

This object is achieved according to the invention in that a guide is provided on pad printing machines of the type mentioned at the beginning, with at least one guide projection running essentially perpendicular to the plate surface on the pressing device and/or on the hollow body and with at least one guide receptacle on the hollow body or on the pressing device, with the guide receptacle enclosing the guide projection with play essentially perpendicular and/or essentially parallel to the plate surface. If the hollow body with its squeegee edge runs onto an unevenness in the plate surface in such a pad printing machine, the squeegee edge can move out of the way together with the other parts of the hollow body in a direction perpendicular to the plate surface. The pressing force acting between the squeegee edge and the plate ensures that

the rake edge closely follows the contour of the cliché surface. Accordingly, even uneven clichés produced with relatively little production effort can be effectively and cleanly squeegeed on pad printing machines according to the invention. Even with the help of uneven clichés, a perfect print image can be applied to the printed material. The play between the pressing device and the hollow body moves in the μη-ββ range. In any case, it must be provided in a direction perpendicular to the cliché surface. If there is play between the hollow body and the pressing device perpendicular to the cliché surface, the hollow body can move translationally in this direction as soon as it runs into an unevenness of the cliché with its squeegee edge. Advantageously, in addition to play perpendicular to the cliché surface, play parallel to it is also provided between the hollow body and the pressing device. Under these circumstances, the hollow body can perform tilting movements around axes parallel to the plate surface as soon as the doctor blade edge encounters unevennesses on the plate.

In order that the hollow body can carry out its evasive tilting movement unhindered, regardless of the direction of the squeegee movement, particularly in embodiments of the pad printing machine according to the invention with vertical and horizontal play between the hollow body and the pressing device, an advantageous embodiment of the invention provides that the pressing device is supported on the area of the wall of the hollow body facing away from the cliché.

-A-

In the case of pad printing machines according to the invention, in which the hollow body has an axis of symmetry running essentially perpendicular to the plate surface, an optimal evasive behavior of the hollow body can be achieved by providing the guide holder on the hollow body in the area of the axis of symmetry, and the pressure device in the edge area of the guide holder is supported on the part of the wall of the hollow body facing away from the plate. Regardless of the direction of the relative movement between the plate and the hollow body sliding on it, an equally unhindered evasive movement results when the squeegee edge of the hollow body hits unevenness in the plate surface.

It is expedient that the guide projection is designed as a centering cone and that the guide receptacle surrounds the guide projection with correspondingly inclined counter surfaces. With a pad printing machine designed in this way, effective guidance of the hollow body on the pressing device and, at the same time, favorable evasive behavior of the hollow body are guaranteed.

The invention is explained in more detail below using the schematic representation of an embodiment.

The illustration shows a bottomless hollow body 1 serving as the inking and doctoring device of the pad printing machine in question, which rests on a cliché 2. The hollow body 1 is made up of several parts and is supported on the surface of the cliché 2 by means of a doctoring ring 3. The doctoring ring 3 is

Threaded clamping ring 4 is fixed to a base body 5 of the hollow body 1. The threaded clamping ring 4 is provided with blind holes (not shown) into which appropriately designed operating tools can engage to tighten or loosen the threaded clamping ring, for example when replacing the doctor ring 3 due to wear.

Magnets 6, 7, which are embedded in the inner wall of the base body 5 as components of a pressing device 8, are used to generate the contact pressure that must act between the surface of the cliché 2 and the doctor ring 3 of the W hollow body 1 during the doctoring process.

Also part of the pressing device 8 is a holding arm 9, which is pivotably mounted on the frame of the pad printing machine at its end (not shown) and is subjected to force in the direction of the surface of the cliché 2 by means of an adjustable compression spring (also not shown).

At its free end, the holding arm 9 has a guide projection 10 which engages in a guide receptacle 11 of the hollow body 1. The guide projection 10 is frustoconical over part of its length and is surrounded by correspondingly shaped counter surfaces of the guide receptacle 11. There is a play in the μm range between the guide projection 10 and the guide receptacle 11 both perpendicular to the surface of the cliché 2 and parallel to it.

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-S-

The holding arm is supported by a collar 12 and a disk 13 on the area of the wall of the hollow body 1 facing away from the cliché 2.

If the cliché 2 and the hollow body 1 now carry out a relative movement in the longitudinal direction of the cliché 2 during the squeegeeing, both components are pressed against one another due to the effective magnetic force and the contact force introduced via the holding arm 9. This prevents the ink inside the hollow body 1 from running out and enables the excess ink on the cliché surface to be effectively stripped off. If the hollow body 1 now runs onto an unevenness of the cliché 2 with the edge of the squeegee ring 3 sitting on the cliché surface, the hollow body 1 can carry out a tilting movement due to the play between the guide projection 10 and the guide holder 11. As a result, the squeegee edge of the squeegee ring 3 can closely follow the unevenness of the cliché 2 and remove the excess ink both on the unevenness and in its surroundings.

Claims (4)

20 301 S1/nu claims 1. Pad printing machine with at least one bottomless hollow body (1) as a coloring and doctoring device and with a pressing device (8) supported on the hollow body (1) for pressing the hollow body (1) onto a cliché (2), wherein the hollow body (I) is guided on the pressing device (8), characterized by a guide with at least one guide projection (10) running essentially perpendicular to the plate surface on the pressing device (8) and/or on the hollow body (1) and with at least one guide receptacle (11) on the hollow body (1) or on the pressing device (8), wherein the guide receptacle (II) surrounds the guide projection (10) with play essentially perpendicularly and/or essentially parallel to the cliché surface. 2. Pad printing machine according to claim 1, characterized in that the pressing device (8) is supported on the region of the wall of the hollow body (1) facing away from the cliché (2). 3. Pad printing machine according to claim 1 or 2, wherein the hollow body (1) has an axis of symmetry running substantially perpendicular to the plate surface, characterized in that &thgr;— that the guide receptacle (11) is provided on the hollow body (1) in the region of the axis of symmetry and the pressing device (β) is supported in the edge region of the guide receptacle (11) on the part of the wall of the hollow body (1) facing away from the cliché (Z). 4. Pad printing machine according to one of claims 1 to 3, characterized in that the guide projection (10) is designed as a centering cone and the guide receptacle (11) surrounds the guide projection (10) with correspondingly inclined counter surfaces.