DE2754080A1 - Plate clamp for printing plate cylinder - provides clamping action and precisely known clamping force using conically tipped clamp elements - Google Patents

Abstract

The support and mounting surfaces of the clamping elements (7) are protected by e.g. enclosures against the ingress of dirt so that their friction properties remain constant. The clamping rail for the plate end is moved by a single operating element via a shear linkage. The clamping forces are applied to the conically-tipped clamping elements (7) by a ratchet screw providing variable torque adjustment. A strip of hardened steel is located on the cylinder channel flank facing the rear clamping strip.

Description

Device for spinning pressure plates in printing machines

The invention relates to a device for registering Clamping of printing plates on the plate cylinder of printing machines in the channel of the plate cylinder arranged clamping rails on which the plate ends can be fastened are, the tensioning rails in the circumferential direction of the plate cylinder dti rcli tensioning elements 1) are ewegl> ar.

Such devices are already through several publications known. For example, from DT-OS 2 200 187 there is a device for precise positioning Fast clamping of flexible printing plates and cylinder lifts known. At this The device is used for fast mounting of flexible printing plates rear tensioning rail by means of a rocking lever gearbox, captivating on one Central tensioning shaft angcordlleten eccentrics and on the other hand the rear tensioning rail hinged rocker arms, slidable ####, a front tensioning rail through adjusting bolts Arranged so that it can be fixed in a zero position. However, this device has the disadvantage indicates that the pressure plate cannot be clamped in a defined manner.

This can lead to an overstretching of the pressure plate and specifically In the case of aluminum plates, cracks occur in the pressure plate. Make such damage a printing plate unusable.

The known devices also have the following features: through the arrangement of several clamping elements l.ings of the clamping rail, the Plate to be twisted. This and the fact that the clamping elements as a result of Soiling by paint and solvents are difficult to move, leads to the fact that the printing plate is different across the width strong is sucked in. Bies also has the consequence that the plate expands and shrinks, whereby the registration is no longer given.

The invention is based on the object of a plate clamping device to create by means of which the pressure plate with a precisely defined tension can be stretched on the plate cylinder. Furthermore sell by means of this device extremely fast clamping of the pressure plate can be made possible.

An exemplary embodiment is based on the following schematic drawing describe in more detail.

It shows: FIG. 1 a plan view of a plate cylinder and FIG. 2 a sapon element in encapsulated form.

In the channel (2) of the plate cylinder (1) there are two sapnn rails (3) and (4) arranged, which are supported on the flanks (3 ') and (4') of the channel (2). If the pressure plate (5) is to be mounted in the rails (3) and (4), the Loosen the clamping screws (7), i.e. the front clamping rail 93) is moved by approx. 0.3 to 0.5 mm to the flank (4 ') and the rear Sapnnschiene (4) is by approx. so mm approached the flank 3 '. Then the pressure plate (5) is in clamped on the slide rails (3) and (4). When clamping the printing plate, the moves Printer as follows: The rear tensioning rail (4) is supported on the one hand by means of Sapnnscrews (8) and on the other hand by a pair of scissors (9) on one on the flank (1 ') attached bar (10) (see Fig. 2). By turning a screw (11), which is in operative connection with the scissors (9), the tensioning rail (4) can be parallel moved to the cylinder axis. A carriage screwdriver is used for quick adjustment. If the screw (11) is scraped against the bar (10), the scissors (9) moved towards the center of the cylinder and the rear tensioning rail (4) over the articulations (12) and (13) if necessary, so that the pressure plate (5) is tensioned. Daunit if possible there is little friction, the scissors (9) are supported by rollers (14) and (15) on the bar (10). after the tensioning screws (8), if necessary using a ratchet screwdriver are tightened, the front tensioning rail (3) by an amount of approx. 0.3 to 0.5 mm stretched. The purpose of this is to remove any air that may still be present between Printing plate (5) and plate cylinder (1) is pushed out.

So that the pressure plate (5) is always evenly tensioned, finds Use a tool with torque limitation or torque setting. For this serves, as already mentioned, a ratchet screwdriver, which by compressed air or can be indicated differently. So that there is as little friction as possible, the clamping screws are encapsulated against the effects of dirt by means of a protective agent (19) or rotatably mounted on their support surfaces by a bearing (17) (18).

The tip (7 '), (8') of the Sapnnscrews (8) is conical and is centered in the finer bearing washer (17), which in turn is located in the bar (10) centered and supported on the Lerste by means of a roller bearing (18). Daunit that The thread of the clamping screw is protected from wastage, are each deformable Sehutrmittel (19) provided. By means of a suitable control there are different pressure ranges can be selected so that the ratchet wheel can be adjusted to different torques is. This makes it possible to have a corresponding clamping force for each type of plate is attached, which causes a stretching in the case of a trimetull plate or a tearing reduced in the case of an aluminum plate.

To facilitate the lateral adjustment of the rear tension bar between the glinderk @@@@@@@ and the bar (10) there is a strip (20) ans @@@@@@@@@ dem la germt @@@@@ arranged. This also ensures that you are at a side Adjustment of the clamping bar cannot bend the screws (7) (8).

When loosening the tensioning screws (8) it is because of the automatic It is necessary to switch off the R @@@ screwdriver against a stop (21) by means of the washer (10), which is firmly connected to the screw (8), close permit.

L e r s e i t e

Claims (5)

Claims 1. Device for clamping printing plates in register on the plate cylinder of printing machines with arranged in the channel of the plate cylinder Slide rails on which the ends of the panels can be fastened, the slide rails are movable in the circumferential direction of the plate cylinder by clamping elements, d a d u r c h e k e n fl z e i c h n e t that the bearing or support surfaces of the clamping elements (7, 8) protected against contamination by protective means (19) and the friction values thus kept constant that the tensioning rail (4) for the plate end through a single actuating element (11) can be moved in the clamping direction via scissors (9) is and that the clamping forces via a torque adjustable ratchet screwdriver can be applied to the clamping elements (7, 8). 2.) Device according to claim 1, characterized in that on the the rear clamping bar (4) facing cylinder channel flank (3 ') from a bar (10) hardened steel is arranged. 3.) Device according to claim 1 and 2, characterized in that the tips (7 ', 8') of the clamping elements (7 and 8) are conical, whereof these tips are centered in a bearing washer (17) which extends over a roller bearing (18) on a hardened bar (10) in the cylinder duct. 4.) Device according to claim 1-3, characterized in that the ends of the scissors (9) supported on the bar (10) with rollers (14 and 15) are provided. 5.) Device according to claim 1-4, d a d u r c h g e k e n n z e i c h n e t that between the flank (3 ') and the bar (10) a strip (20) is arranged from stock material.