DE29505373U1 - Protection device on a sheet-fed printing machine - Google Patents

Description

lROLANDl

&lgr;&idigr;&Agr;&Ngr; Roland Druckmaschinen A G Mühlheimer Str. 341 D-63075 Offenbach

Protective device on a sheet-fed printing press

The improvement concerns a protective device on sheet-fed printing machines for
Covering machine parts. A device of this type is known from the

To protect rotating machine elements, especially on printing machines, it is now necessary to provide extensive protective measures.

Folding protective devices are provided which are fitted between the fixed machine side parts. Depending on the position of the machine parts or the printing units to be operated, measures must also be taken in addition to these protective devices to make the printing unit parts accessible. For example, for maintenance and
For maintenance work, areas on the machine must be provided where the operating personnel can stay. Therefore, the pollution for this work must be removed as far as possible from the work area.

DE 3 114 475 Al describes a protective device on rotary printing machines
It shows a multi-part system of flat protective devices that cover the access area to the rotating parts of a printing unit. The protective devices are designed in such a way that when folded away, for example,

maintenance work can be folded up as space-saving as possible. Despite this, the guards must be folded down in different directions in order to be able to reach the various machine elements. In addition, the
After the gates have been folded away, operating personnel in various areas of the printing units have no supports for safe support during maintenance work.

The aim of the improvement should therefore be to provide protection which, in addition to providing adequate protection, also serves to improve accessibility to the printing machine.

This object is achieved according to the characterizing part of claim 1. It is particularly advantageous that a guard in the area of a printing unit that is relatively difficult to access, e.g. above a sheet-fed system, is only made properly and safely accessible by folding down a guard. The combination of the advantageous features of improved protection and easier access increases the ease of use and operating safety, particularly in sheet-fed printing machines or generally in printing machines with larger widths.

An exemplary embodiment of the invention is illustrated in more detail below with reference to drawings.

Shown here:

Fig. 1 a schematic overview of a printing unit and

Fig. 2 shows a more detailed representation of the folding step.

Fig. 1 shows a printing unit 1 of a sheet-fed rotary printing machine. It contains an inking unit 2, a dampening unit 3, a plate cylinder 4, a blanket cylinder 5 and a printing cylinder 6. The sheets to be printed are transported via a sheet feeder 8 and a feeder drum 7 and fed to the printing cylinder 6. The sheet feeder 8 contains all the known alignment elements required for precise sheet feeding, such as front lays, side pull lays and a so-called pre-gripper. These elements are not shown in detail here. The printing unit 1 with the inking unit 2 and the dampening unit 3 is located above the sheet feeder 7. Various work must be carried out on both devices, e.g. for cleaning or adjustment. This also applies to the plate cylinder 4 and the blanket cylinder 5. The printing unit 1 is therefore provided with a foldable protective cover on this side. A protective cover 9 covers the

upper area of the printing unit 1 at the level of the inking unit 2. A further guard 10 covers the area of the dampening unit 3. The guard 10 is followed by a further guard 11, which is arranged at the level of the rubber cylinder 5. The guard 11 can be folded down over the sheet feeder 8. It is designed as a folding step and is shaped so that it is very stable, in that a bevel 13 is provided on both longitudinal edges of a step plate 12. In addition, it is made of a stable material, as is used for normal footsteps on the printing machine. If, for example, maintenance work has to be carried out in the area of the dampening unit 3 or the rubber cylinder 5 on the printing unit 1, the guard 11 or the folding step can be folded down over the sheet feeder 8 and the operating personnel can easily enter this area, which is normally inaccessible or can only be accessed with great difficulty. This makes the support and service work of the operating personnel considerably easier, even for the upper areas of the printing unit 1. This advantage is particularly evident in printing machines with large dimensions. At the same time, the sensitive area of the sheet system 8 is protected against damage.

In Fig. 2, a suspension of the protection 11 designed as a folding step is shown in detail and indicated in two positions I and Π. The protection 11 consists of a step plate 12, on which a joint 19 is connected to two sides of a machine frame 20 via two articulated arms 14. In addition, bevels 13 are provided on the two longitudinal edges of the protection 11, so that they extend over the entire width of the printing unit 1.

In position I, the guard 11 is in its closed position. The position is monitored with the help of a safety switch 15 via a switching curve 16 in such a way that the printing press is immediately stopped when the guard 11 is folded down. The folded-in position I is secured in its position by the special design of the articulated arms 14. Due to the curved design of the articulated arms 14, the pivot point of the guard 11 is moved at the joints 19 towards the machine frame 20 in such a way that the guard 11 is held in the rest position by its own weight against stops 17 on the printing unit 1.

In position II, the guard 11 is shown in its swiveled-down position or in a position that can be walked on by the operating personnel. It rests on support rails 18 that secure it in its position. As shown here, the step plate 12 is horizontal and the two bevels 13 stabilize the guard on the two long sides so that it can be walked on. One bevel 13 serves as a handle for pulling the guard 11, while the other bevel 13, which is located on the hinge side of the guard 11, serves both as protection against stepping over in the machine area and, in the vertical position, to catch any parts that may have remained on the guard 11 after it has been swiveled in.

In Fig. 2 it can also be seen that the entire area of the sheet feeder 8 is covered when the guard 11 is folded down. This makes this area accessible to the operating crew and the machine is accessible from all sides for auxiliary work. As described above, the folded-down position Π is secured by the electrical safety switch 15 so that the printing machine cannot be started up inadvertently in the open state. The position of the step plate 12 relative to the joints 19 is another safety function. The guard 11 cannot be accessed beyond the joints 19, i.e. inside the printing unit 1, due to the bevel 13 facing the printing unit 1. This means that its position is also safe in the folded-down position Π.

The guard 11 can be relatively heavy on larger printing machines and must be guided for safe operation when folding in and out. Therefore, an additional damping or spring element can be designed in such a way that when folding in and out the guard 11, weight is relieved and it is guided when it is placed against the stops 17 or the support rails 18. However, the use of lightweight material is preferred to simplify handling. The arrangement of the bevels 13 allows this to be done in many areas.

1 • · » ·· ··· · 2 ·· ·· ·· ··· 3 List of reference symbols: 4 Printing unit 5 Farbwerk 6 Dampening system 7 Plate cylinder 8th Rubber cylinder 9 Pressure cylinder 10 Feed drum 11 Arch system 12 Protection 13 Protection 14 Protection 15 Treadplates 16 Bending 17 Articulated arms 18 fuse switch 19 Switching curve 20 attacks I Support rails &Pgr; Joints Machine frame position position

Claims (3)

Expectations 1.) Protective device on a sheet-fed rotary printing machine with several printing units and a sheet system for feeding printed sheets, wherein flat protective covers are provided on at least one printing unit to cover dangerous areas within the printing unit and to be folded down for maintenance work within the printing unit, characterized in that that a protection (11) is attached to a first printing unit (1) above the sheet feeder (8) and can be folded down from a first position (I) in contact with the printing unit (1) into a second horizontal position (&Pgr;) above the sheet feeder (8) and that the protection (11) is designed as a folding step. 2.) Protective device according to claim 1,
characterized, that the guard (11) is attached to the printing unit (1) with articulated arms (14) for pivotable fastening to joints (19) above the sheet feeder (8) in such a way that the center of gravity of the guard (11) in position (I) on the printing unit (1) lies between the joints (19) and stops (17) on the printing unit (1), and that the guard (11) in the folded-down position (&Pgr;) can only be loaded on the side of the joints (19) facing away from the printing unit (1). 3.) Protective device according to claim 1,
characterized, that the protection (11) consists of a step plate (12) with bevels (13) formed on the long sides in the transverse direction across the width of the printing unit (1).