GB2288861A

GB2288861A - Machine guard

Info

Publication number: GB2288861A
Application number: GB9508462A
Authority: GB
Inventors: Wolfgang Bitterich
Original assignee: Heidelberger Druckmaschinen AG
Current assignee: Heidelberger Druckmaschinen AG
Priority date: 1994-04-28
Filing date: 1995-04-26
Publication date: 1995-11-01
Anticipated expiration: 2015-04-26
Also published as: DE4414836A1; DE19531643C1; GB9508462D0; GB2288861B; DE4414836C2

Description

1 MACHINE GUARD 2288861 The invention relates to a machine guard,

especially on a printing machine, located between the machine side frames. The guard is designed for covering a printing unit/coating unit of a printing machine, on both sides thereof, with vertical sides and with an upper horizontal part, parts of said guard being mounted on swivel arms and being liftable into an opened position while being supported by means of spring elements.

Large area protective devices are applied on printing machines in various ways in order to protect the operating staff against accidents while the machine is in operation. It is a prerequisite that such protective devices can be opened at standstill of the machine in order to make the individual parts of the machine as accessible as possible. For reasons of safety, the printing units of a printing machine, which have a plurality of rotation cylinders and rollers, have to be equipped with a guard; when opening such a guard, a respective control element automatically causes a standstill of the machine. While maintenance and adjusting jobs are effected at standstill of the machine, it is important to the operator to have the greatest possible access to the individual parts of the machine (DE 31 15 475 A1) in spite of protective devices, without the protective devices representing mutual obstacles.

Accordingly, it is an object of the invention to provide a guide that provides optimum accessibility to the parts of a printing machine.

According to the invention, the two vertical side parts of the guard can be lifted from a closed position independently of each other, and by means of hinge connections the upper part, located horizontally when in said closed position, is lifted as well when lifting a side part. By providing such a guard on a printing machine, the pressman may lift a side part and, in so doing, he also 2 obtains free access, for example, to an inking unit of the machine from above. Thus, he no longer has to swing away or to remove several parts of a guard when performing a maintenance job.

Preferably, the upper part of the guard is pivotmounted on a second frame which is as long as the upper part and in alignment with said upper part, and the second frame is pivot-mounted, on one side thereof, on the machine side frames, and on the other side thereof it is connected to the upper part of the guard via pivots so as to be swivellable. Thus, it is possible simultaneously to swing away the guards on both sides of the printing unit, as a result of which the upper part is also swung upwards. Hence, it only requires two manipulations to make the machine part directly accessible to the pressman from both sides and from above.

It is preferred that, via pivots, the side parts are connected to the upper part of the guard, that, via swivel arms, each side part is mounted on the machine side frames, and that spring elements act on said swivel arms. This facilitates the opening and closing of the guard and secures the opened position of said guard.

A preferred embodiment of the invention is now described by way of example with reference to the partly schematic drawings, in which:- FIGURE 1 is a side elevational view of the guard for a printing unit/coating unit of a printing machine; FIGURE 2 is a top view of the guard; FIGURE 3 shows the guard opened on both sides; FIGURE 4 shows the guard which has been opened on the left side; and FIGURE 5 shows the guard which has been opened on the right side.

When in a closed state, the guard shown in Figure 1 covers a coating unit of a printing machine, for example.

Said guide is disposed between the side frames of the machine and consists of two upright side parts 1, 2 and upper part 3 which, when in a closed state, is horizontal (Figure 1). Swivel arms 4 f or the left side part 1 are Ov 3 mounted on machine side frames 6, 7 via trunnions 5, at one end and at their other end via pivots 8. In the vicinity of the trunnion 5, one end of a spring element 10 is supported on the swivel arm 4 via a bolt 9, the other end being connected to the machine side f rame 6, 7 by means of a bearing bolt 11. When in a closed state. both sides of the side part 1 come into contact with stops 12 also fastened to the machine side frame 6, 7. A traverse 13 serves to stabilize the swivel arms 4 and is fixed therebetween. via a handle 14, the side part 1 may be opened. The side parts 1, 2 may be made of perforated metal sheets, and the upper part 3 may be made of safety glass placed in an appropriate frame. In the side parts 1, 2 there are provided stops 15 against which the swivel arm and its equivalent arm 16 for the side part 2 abut, when in a opened position.

As can be seen in Figure 1, the right side part 2 is also supported, on both sides thereof, by swivel arms 16 via pivots 17. Said swivel arms 16 are mounted on the machine side frames 6, 7 via trunnions 18 and are supported, via bolts 19, on spring elements 20 which may be mounted on the trunnions 5 of the swivel arms 4. Via a gripping depression 21, the right side part 2 may also be opened in a simple manner.

The upper part 3 of the guard is pivot-mounted on a second frame 23 via pivots 22. At its end remote from said pivots 22, the second frame 23 is mounted on the machine side frames 6, 7 via trunnions 24. At the same time, the side part 2 is swivellably connected to the upper part 3 via said pivots 22. Furthermore, the side part 1 is swivellably connected to the upper part 3 so as to be in alignment with said trunnions 24 being in an idle position.

In Figure 2 electric safety switches 5, 18 are shown on the trunnions 5 which cause a standstill of the machine or prevent the machine from being started, when opening the side parts 1, 2. In its closed state, the upper part 3 also comes to rest on stops 27 fastened to the machine side frame 6, 7.

Figure 3 shows the guard in an opened position, with 4 both side parts 1, 2 being swung upwards so that, in the position indicated, the upper part 3 is also swung away. Due to the advantageous hinge connections it is thus possible to open the upper part of the guard to such an extent that said machine part is directly accessible to the pressman from both sides.

Figure 4 is distinguished from the other Figures in as much as merely the left side part 1 and upper part 3 is opened.

Figure 5 shows the right side part 2 and upper part 3, in their respective opened position, with the side parts 1, 2 abutting against the swivel arms 4, 16 due to the force of the spring elements 10, 20. Thus, the pressman may obtain direct access to the respective machine part as required.

When opening the guard, the machine is prevented from operation by means of one limit switch or several limit switches. Hence it is impossible to start or operate the machine, thus eliminating for the pressman the danger of an accident.

It will of course be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

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Claims

CLAIMS:

1. A machine guard, e.g. for a printing machine, and adapted to cover both sides thereof, said guard being located between the machine side f rames and having vertical side parts and a horizontal upper part, said parts being mounted, on both sides thereof, on swivel arms, and being liftable into an opened position while being supported by spring elements, wherein the two side parts can be lifted from a closed position to an open position independently of each other, and wherein, when a side part is opened, the upper part which, in a closed position, is disposed horizontally, is lifted as well via a hinge connection.

2. A machine guard according to claim 1, wherein the upper part is pivot-mounted on a second frame which is as long as said upper part and is in alignment with points of rotation of said upper part and wherein said second frame is pivot-mounted via trunnions on one side thereof on the machine side frames and on the other side thereof is connected to said upper part via pivots.

3. A machine guard according to claim 1 or 2,, wherein the side parts are connected to the upper part by pivots.

4. A machine guard according to claim 1, 2 or 3, wherein each side part is mounted on the machine side frames by swivel arms and wherein spring elements act on said swivel arms.

5. A machine guard, substantially as hereinbefore described with reference to the accompanying drawings.

6. A printing machine provided with a machine guard as claimed in any one of claims 1-5.