EP2346762B1 - Securing a hazardous area in the region surrounding the automatic loading of reels on a reel changer - Google Patents

Description

The invention relates to a hazardous area protection for the field of automatic reel placement on a reel changer according to the preamble of claim 1. Such a danger area coverage, which is considered to be the closest prior art, is from the patent application WO 2005/080241 A known.

Technical equipment, such as machine tools and industrial robots, involves the risk of injury to persons approaching the moving parts of the machine. Danger points on a reel changer are, in particular, the pivot range of the roller support arms, the area behind the reel changer in the swivel range of the adhesive frame, the placement area, and the pit below the reel changer, if present. It is therefore necessary to provide machines with protective devices which prevent a person from being injured by the execution of a working movement of the moving parts of the machine. In the past, mainly mechanical protective devices have been used for this purpose. Machine tools are often completely enclosed, with access via protective doors. Industrial robots are operated in areas surrounded by protective fences.

Mechanical guards, however, are associated with disadvantages. For the protective device itself and also for the opening of any existing safety doors corresponding space must be present, which increases the footprint of the entire system. In addition, a quick intervention in the production process is not possible because the opening of guard doors or guards is associated with a corresponding time and tax expense. In addition, mechanical guards are not maintenance and wear-free.

In the DE 10 2005 048 466 A1 a personal protection device is described on a reel changer of a printing press, which is designed for example in the form of a safety net on the loading side of the reel changer. This protective device should make the loading side always a secure space when the residual paper roll approaches a critical, ie fracture endangered Durchmessermaß. In this way, persons on the reel splitter should be reliably protected against fragments of bursting rolls. For this purpose, the protective device is mounted on the transfer stage used to feed new rolls of material and at a fixed point relative to the roll stand on the loading side. To feed a new roll of material, the traverser moves to the roll stand, wherein the guard strains. Thus, the protective device is activated only when the described critical state of the residual paper roll is achieved. At any other time, the area on the loading side of the reel changer can be entered unhindered. However, in order to point out the danger situation to persons in the potentially endangered area even when the mechanical protective device is not active, additional area protection by means of light barriers is proposed. Due to the signal emitted by the light barrier, a visible or audible signal is emitted to the person located in the area of the reel changer.

From the WO 2005/080241 A2 It is known to provide an area coverage for the reliability in the environment of large moving material rolls. Here, the attachment of a fence is proposed at the boundaries of a roll of material storage. For introducing or removing material rolls into the bearing, a lock may be provided in the area protection. In the lock area, a preferably non-contact area security is proposed, which can be realized for example via light barriers or ultrasonic sensors. By arranging such sensors at different heights, complex query routines can be realized so that, for example, material rolls can easily pass through the lock, whereas an unauthorized passage through the lock can be achieved Sensor sections triggers an alarm and / or stops the movement of the material rolls to prevent accidents.

The EP 08 49 201 A1 relates to a method for lateral position detection and positioning a supply roll, wherein the roll thickness and the respective lateral distance to the roll changer by directly opposite sensing elements in the form of sensors, for. B. laser beam or ultrasonic sensors are measured and evaluated. Furthermore, the scanning elements are connected to a programmable logic controller for a drive unit for positioning the supply web roll.

In the EP 15 93 630 A2 there is disclosed an apparatus for preparing a web of material wound into a supply roll having a bearing for supporting and rotating the supply roll about a longitudinal matter. Sensors are used to detect the radius of the supply roll during the rotational movement. Parallel to the longitudinal axis of the supply roll several, the radius detecting sensors are arranged.

The non-contact devices described in the aforementioned documents are used to detect the position or dimensions of a role in the field of automatic reel assembly on a roll changer and do not fulfill a protective or security function.

From the DE 31 34 815 C2 is a non-contact surface security, for example, for the protection or monitoring of shop windows known. The surface protection has, along one side of the surface to be protected, a source emitting radiation over its entire length. Along the opposite side a reflective strip is arranged. The radiation is predominantly reflected in the plane defined by the source and the reflective strip. At each of the two ends of the radiation source, a radiation detector is provided, which is connected to an evaluation circuit. This area protection can as Continuity fuse can be used for example in hazardous areas by a light curtain is built between two rods, the interruption of a signal is triggered. The disadvantage of this hazardous area protection is that it can only take over a simple protective function.

From the DE 199 38 639 B4 a device for securing a danger zone, in particular the danger zone of an automated machine is known, which comprises first means for generating an optically monitored, virtual barrier and second means for generating a switching signal for stopping the machine when breaking the barrier. The first means comprise an image acquisition unit and a defined target whose image is taken by the image acquisition unit and compared by a comparison unit (second means) with a characteristic size for a reference image. The defined goal is a structured, high-contrast pattern that includes position markers for determining a current position. With a dot-shaped pattern according to an exemplary embodiment of the device, the generation of a virtual barrier is possible whose shape approximately corresponds to that of a light barrier. Alternatively, however, a plurality of dot-shaped patterns may be strung together to form a linear pattern. This device only fulfills a protective function. The evaluation and the comparison of the recorded images with the reference image is complicated.

The DE 296 02 098 U1 refers to a reel changer in a web-fed rotary printing press for introducing a printing material web wound on rolls into a printing unit of the web-fed rotary printing press. The area surrounding the reel changer is replaced by at least one sensor, in particular an optical sensor, for. B. monitors a camera which is connected to an image recognition computer. In the image recognition computer, a comparison is made between a captured actual image of the region and a stored target image or a sequence of target images. In case of deviations is by a Signal generating device generates a warning or alarm signal. The at least one sensor may also include step mats, contact strips, light barriers, or the like, non-contact protective devices which serve to supply partial information or to control or activate the sensor. The solution disclosed in this document allows monitoring of the area of the reel splitter, thereby providing selective protection by recognizing known objects and allowing them to enter the area without triggering warning or alarm signals. However, the image recognition can easily be influenced by subjective factors in the monitored area, eg. B. a deviating position of one of the target image as known to be recognized object on a captured actual image, which can lead to malfunction or malfunction.

The DE 100 26 305 A1 describes an optoelectronic device for monitoring a protected area with at least one non-contact protective device, which has an evaluation unit for generating an article detection signal when an object penetrates into the protected area. The non-contact protective device may be a light grid, which comprises a transmitting unit emitting light beams, a receiving unit receiving the light beams and an evaluation unit connected to the receiving unit. In order to perform an additional function in addition to the protective function, the non-contact protective device is coupled to an image acquisition unit for detecting a secondary monitoring area which is close to the protected area but outside the protected area. This so-called muting function allows the temporary deactivation of the non-contact protective device for the penetration of detected objects into the protected area without generating an object detection signal. The muting function is implemented by the image acquisition unit, which detects the objects penetrating into the secondary monitoring area, wherein a distinction is made between permissible and impermissible objects. A classification of the detected objects is possible. The disadvantage of this solution exists in that the recognition of known objects does not always work reliably. In addition, the establishment of an additional image capture unit is associated with additional expense and financial expenses.

From the DE 10 2005 030 829 A1 a method for operating a light grid is known in which a switching signal is generated from the sequential interruption of the light beams with stored reference behavior.

In the DE 10 2004 038 906 A1 It is proposed to transmit a mark on an object to an evaluation device in addition to a light grid.

In the DE 295 00 873 U1 the order of interruption of the light rays of a light grid is detected in order to distinguish permissible objects or, for example, persons.

The invention has for its object to provide a Gefahrbereichsabsicherung for the field of automatic roll loading on a reel splicer.

The object is achieved by the features of claim 1.

The advantages which can be achieved with the invention are, in particular, that an improved danger area protection based on non-contact protective mechanisms for the automatic reel placement on a reel changer is available which ensures permanent protection of the secured area even with different reel diameters and the removal of residual sleeve containers ,

The hazardous area protection has a non-contact protective device, which is connected to an evaluation unit. The protective device is as Light grating formed, which has a plurality of mutually parallel light beams. The evaluation unit detects the order of interruption of the light beams when entering and / or extending any object and can recognize a known object therefrom and deactivate the protective device in predetermined cases.

The advantages of the invention are to be seen in particular in that the protective device in addition to a protective function also has a muting function, which saves the effort for setting up an additional device for the muting function.

A so-called muting function allows time-limited deactivation of parts of a safety device or the entire safety device. Preferably, the penetration of objects is allowed without the safety device to operate.

In a preferred embodiment, the light rays are evenly spaced from each other and are inclined to the horizontal, wherein the light rays in other embodiments, also horizontally extending and the surface of the light grid can be arranged inclined to the vertical.

At least one light beam of the light grid running above the known object can advantageously be permanently active in order to detect the penetration of a person or a non-authorized object into the secure area of the automatic roll placement on the roll changer, even if these together with the known one and for the entrance permissible object penetrate into the secured area when the protective device is deactivated.

The well-known and admitted for the entry object may, for. B. be a roll of material, a residual sleeve container or a driverless transport vehicle.

Irrespective of this, the hazardous area protection can additionally include at least two photocells for muting, eg. B. reflection photo cells, which are connected to the evaluation unit. In a preferred embodiment, in particular four reflection photocells are installed as a muting group (two each before and after the light grid). In this way, objects, in particular residual sleeve containers, can be used on the basis of e.g. Detected laterally glued reflection strip and the muting function is activated, or the protective device can be disabled. This may be necessary in particular when removing the residual sleeve container, which have a different shape compared to the rollers. If, for example, only rollers are implemented as known objects in the evaluation unit (because of the shape and the simple evaluation of the interruption order of the light beams), the muting function can be carried out by reflection strips on the residual sleeve container. The removal of the residual sleeve container is often done with driverless transport vehicles (AGV = automatic guided vehicle). These must also be provided with reflective strips for muting to pass through the security area or in the evaluation unit, a corresponding interruption order of the light beams of the light grid must be known to recognize the AGV as a known, approved for entry into the security area object.

To safeguard the protected area against intrusion of persons or objects together with the known object when the protective device is deactivated, the hazardous area protection can have a second permanently active, non-contact protective device comprising at least two light beams which intersect at a small distance above the known object and in their further course be passed close to the known object. These two light beams thus run only a few millimeters to a few centimeters apart parallel to imaginary tangents, which rest against the upper half of the known object. The lower ends of the two light beams are thus clearly below the upper edge of the known object and can, depending on the selected angle of attack near the Axial plane of the known object lie.

An advantage of the invention is that a reliable, permanent hazardous area protection can be realized by the second permanently active, non-contact protective device, even if the known object is a roller having a larger roller diameter. The beam path does not permit unintentional overrun or inadvertent underrun of the beams of the second protection device. An underrun of the rays is at best possible when people move in a strongly bent state. But even the best protection device can protect only to a limited extent against all eventualities or against deliberate evasion. It can not be their job to safely prevent a willful intrusion in any case.

Another advantage of the invention is that the protective device can be attached directly to the roll changer. Thus, in contrast to the previously known solutions, which require an attachment point arranged above the roller, no additional attachment points lying outside the reel changer are required.

According to a particularly preferred embodiment, the non-contact protective device and / or the second permanently active, non-contact protective device per light beam comprise a transmitter and a receiver. However, embodiments are also possible in which the protective devices for all light beams comprise exactly one transmitter, one receiver and a plurality of deflecting mirrors.

In an advantageous embodiment, one-way photocells are used in the aforementioned protective devices, in which transmitter and receiver are arranged opposite one another, in separate housings.

Particularly useful is the use of photoelectric retro-reflective devices for said protective devices has been found. In these embodiments, a combined transmitting and receiving unit is arranged opposite a reflector. The emitted light rays are reflected back to the receiving unit via the reflector.

Furthermore, it is advantageous if the position of the transmitter, receiver, reflector or deflecting mirror is variable. In this way, adaptation to different than known and authorized for access to the secure area objects can be made. In this context, it has proven to be particularly advantageous to equip the hazardous area protection with a sensor for detecting the dimensions of the known object.

Particularly for the proper functioning of the second permanently active, non-contact protective device, it must be ensured that the beams do not touch the known object, since this is intended to protect the danger zone during the retraction and / or extension of a known object when the first protective device is inactive. Accordingly, the second protective device must not be triggered if the known object passes through the access limits. The adaptability to different objects ensures that the rays are always outside the area traveled by the known object.

It is advantageous if, in a further developed embodiment, the sensor is connected to an adjusting device. The adjusting device serves for the automatic adaptation of the transmitter, receiver, reflector or deflecting mirror to the known object. By using such a control device ensures that constantly repositioning of transmitter, receiver, reflector or deflection mirror according to the detected dimensions of the known object he follows. Of course it is also possible to do a manual positioning. For this, one could imagine that the reel changer has a corresponding scale, which facilitates manual positioning.

This hazardous area protection has proved to be advantageous for a roll with a roll diameter of up to 1,524 mm. In such large roles could be done with conventional protection devices no longer adequate protection, since the light beams of the second protection device can be undermined by smaller people who only stoop slightly.

The hazard area protection may also include a photocell located within the secure area for positioning a roll or driverless transport vehicle in a launch position.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Fig. 1

eine prinzipielle Anordnung einer Gefahrenbereichsabsicherung für den Bereich der automatischen Rollenbestückung;

Fig. 2

eine perspektivische Darstellung eines Rollenwechslers mit einer Gefahrenbereichsabsicherung;

Fig. 3a

eine Prinzipdarstellung einer Gefahrenbereichsabsicherung für den Bereich der automatischen Rollenbestückung;

Fig. 3b

eine Prinzipdarstellung einer abgewandelten Gefahrenbereichsabsicherung;

Fig. 3c

ein Lichtgitter für eine berührungslos wirkende Schutzeinrichtung einer Gefahrenbereichsabsicherung für den Bereich der automatischen Rollenbestückung mit einer zweiten permanent aktiven, berührungslos wirkenden Schutzeinrichtung;

Fig. 4

eine Vorderansicht einer Ausführungsform der Gefahrenbereichsabsicherung für den Bereich der automatischen Rollenbestückung mit einer Fotozelle zur Positionierung einer Rolle in einer Startposition.

Show it:

Fig. 1

a basic arrangement of a hazardous area protection for the field of automatic roll loading;

Fig. 2

a perspective view of a roll changer with a hazardous area protection;

Fig. 3a

a schematic representation of a hazardous area protection for the field of automatic roll stocking;

Fig. 3b

a schematic representation of a modified danger area protection;

Fig. 3c

a light grid for a non-contact protective device of a hazardous area protection for the field of automatic roll loading with a second permanently active, non-contact protective device;

Fig. 4

a front view of an embodiment of the danger area for the area of automatic roll loading with a photocell for positioning a roll in a start position.

Fig. 1 shows a danger area protection for the range of automatic roll stocking 01 on a roll changer 02 (see Fig. 2 ). Hazardous area protection includes a first, non-contact protection device located at the entrance. To be secured access limits are not only on the roll feed side, but also opposite the Rollenzuführseite, if both sides are freely accessible to persons. The first protective device comprises two light beams 04, which secure the area which can be passed through by a roller 05 or a residual sleeve container, wherein the first protective device can be deactivated to enable retraction and extension. Insofar as below is spoken only by a roll 05 to be retracted into the secured area, this relates in the same way to a residual sleeve container or driverless transport vehicle to be retracted and to the reverse movement sequences during extension of the roller 05 or the residual sleeve container or the driverless transport vehicle.

To change the roller 05, the first protective device can be deactivated. The hazardous area protection furthermore has a second permanently active, non-contact protective device for permanent protection of the surrounding area of the roller 05. The second protection device includes a Light beam 07, which has a distance of 50 mm to the largest (maximum workable roll diameter) roll diameter. Especially with larger roll diameters, however, such a second protective device has proved to be disadvantageous.

As Fig. 2 3a can be removed, there is the danger that a smaller person can run together with the roller 05 in the secure area of the roll loading and thus can be injured by moving machine parts or the moving roller 05.

Fig. 3b shows a Gefahrbereichsabsicherung for the field of automatic reel assembly 01. The danger area protection in turn comprises a first, non-contact protective device at the access limits with two light beams 04, which secure the durchfahrbaren by the roller 05 or the residual sleeve container or the driverless transport vehicle area. For permanent protection of the surrounding area of the roller 05 serves a second permanently active, non-contact protective device. The second protection device comprises two light beams 07 which, starting from points located above the roller 05, lead laterally past the roller 05 to near the bottom. Out Fig. 3b It can be seen that even a protective device designed in this way can not provide sufficient protection. As a result of the fact that the light rays 07 run past the roller 05 almost to the floor, there is the risk that the light rays 07 may be exceeded by a person who, for example, walks alongside the roller 05 during insertion.

Fig. 3c shows a danger area coverage for the range of automatic roll loading 01. This danger area coverage, unlike the known solutions on a light grid 03 for a non-contact protective device on the access limits of the secure area of the automatic roll stock 01 on. The light grid 03 can for retracting or extending roller 05 or residual sleeve container or driverless transport vehicle are disabled. In addition, a second permanently active, non-contact protective device for permanent protection of the surrounding area of the roller 05 is provided, which will be described below. At this point it should be pointed out once again that the access limits to be protected can not only be on the roll feed side but also opposite the roll feed side. Protective devices must be installed on both sides if both sides are freely accessible to persons. The non-contact protective device, in conjunction with the evaluation unit, secures each access limit to be protected by a light grid 03.

In the illustrated embodiment, the light grid 03 is formed by a plurality of mutually parallel light beams 04, which are evenly spaced by preferably 40 mm from each other and inclined to the horizontal. Of course, another distance or different inclinations can be chosen. The light rays 04 can also be arranged horizontally and the surface of the light grid inclined to the vertical, wherein the inclination is preferably 150.

The light beams 04 of the light grid 03 are associated with a transmitter and a receiver, which are positioned at the end points of the light beams 04. The light grid 03 is connected to an evaluation unit, which is not shown. The evaluation unit detects the order of interruption of the light rays 04 when retracting and / or extending a roller 05 or a residual sleeve container or a driverless transport vehicle and disables the hazardous area secured by the light grid 03 upon detection of a known object that allows access to the secured area is.

In the evaluation is evaluated whether the individual light beams 04 of the light grid 03 are interrupted in succession or released again. It does not matter how many or in which area the individual light beams 04 are interrupted. Gaps between the interruption of the individual light beams 04 are not allowed.

Irrespective of this, the danger area coverage also comprises four photocells 06 for muting, in particular reflection photo cells 06, two pairs of reflection photo cells 06 being arranged in front of and behind the light grid 03 in pairs. These are used for deactivating (muting) the light grid 03 upon detection of a known object, in particular a residual sleeve container, which complicate the evaluation of the interruption order of the light beams because of the shape. Furthermore, the reflection photoelectric cells 06 are connected to an evaluation unit, not shown. To detect the residual sleeve container are provided with reflection strips, which are positioned according to the arrangement of the reflection photoelectric cells 06 on the residual sleeve containers. The light grid 03 is muted (turned off) when the reflection strips are detected on a residual sleeve container. After passing through the residual sleeve container by the danger area coverage, the fourth reflection photocell 06 receives no reflection of the light beam more, so then the light grid 03 is activated again.

The muting function can be realized in the case of a driverless transport vehicle with two reflection photoelectric cells 06, since the driverless transport vehicle does not drive completely through the light grid, but only a piece enters the roll changer 02 to deposit the roller 05. The first reflection photo cell 06 detects the reflection strip which is positioned on the vehicle according to the arrangement of the reflection photo cells 06, and turns off the light curtain 03. If the second reflection photo cell 06 receives no reflection of the light beam when returning the driverless transport vehicle, the light grid 03 is activated again.

The two uppermost light beams 04 of the light grid 03 remain permanently active in order to prevent a person or an object from entering the secured area of the automatic reel assembly together with the roller 05 or the residual sleeve container at a roll changer 02 with deactivated danger area protection by the light grid 03 avoided.

The second permanently active, non-contact protective device comprises at least two light beams 07, which extend transversely to the longitudinal extent or axial direction of the roller 05 and intersect at a slight distance above the roller 05 and in its further course passes close to the roller 05 and the roller container become. The crossing point of the two light beams 07 is preferably only a few centimeters, z. B. <15 cm, in particular <8 cm, preferably <5 cm, above the upper roll edge and the light rays 07 are below the crossing point then at a distance of a few millimeters, z. B. <15 mm, in particular <8 mm, preferably <5 mm up to a few centimeters on the roller 05 over. The light rays 07 thus have their upper end points above the roller 05, but outside the roller extension. The lower end points are below the roll upper edge, preferably at a height which is greater than 1/2 of the roll diameter and corresponds to about 2/3 to 3/4 of the roll diameter.

Out Fig. 3c It can be seen that the course of the two light beams 07 neither permits unintentional overflow nor unintentional underflow of the light beams 07. An underrun of the light rays 07 is possibly possible when people move in a strongly bent state.

Fig. 4 shows a front view of an embodiment of the hazardous area protection for the range of automatic roll stocking 01. In the illustrated embodiment, reflection light barriers are used. The second permanently active, non-contact protective device comprises for each light beam 07 a combined transmitting and receiving unit 08. The light beam 07 is thrown from an opposite reflector 09 back to the transmitting and receiving unit 08. This beam guidance can also be used with the light beams 04 of the light grid 03 become. In the second permanently active protection device and / or in the light grid 03, of course, one-way light barriers, in which transmitter and receiver are arranged opposite each other, can be used. In alternative embodiments, all light beams 04; 07 of the light grid 03 and the second permanent active protection device each have exactly one transmitter and one receiver. In these cases, to guide the light beams 04; 07 requires several deflection mirrors. The transmitter can be a light emitting diode or laser diode emitting infrared radiation or visible light, and a phototransistor as receiver.

It has proven to be advantageous if the position of the transmitting and receiving units 08 and the reflectors 09 can be changed. For this purpose, it is expedient to equip the second permanently active protective device with a sensor (not shown) for detecting the roll diameter. The sensor can in turn be connected to an adjusting device (not shown), which performs an automatic positioning of the transmitting and receiving units 08 and the reflectors 09 as a function of the detected roll diameter. In this way, an optimal guidance of the light rays 07 can always be ensured. The position of transmitting and receiving units 08 and the reflectors 09 can of course be corrected manually. In this case, it has proven to be advantageous if the roller changer 02 a corresponding scale is attached.

If a person or an unauthorized object enters the secured area of the automatic reel assembly on the reel changer 02 when the light grid 03 is deactivated, together with the roller 05 or the residual sleeve container, the person or the unauthorized object will at least interrupt the beam path of one of the light beams 07 , This fault is detected by the receiver, converted into corresponding control signals, which cause a shutdown of the reel changer 02. In addition, via an alarm device 11, an alarm in the form of a visible and / or audible signal are output.

The danger area protection preferably further comprises four reflection photoelectric cells 06 for muting and a photocell 12, which is arranged within the secured area of the automatic reel placement on the reel changer 02 for positioning the reel 05 in a start position and connected to an evaluation unit, not shown. The roll 05 coming from the upstream feed passes through the danger area protection and the detection area of the following photocell 12. The evaluation unit recognizes the freeing of the photocell 12 and stops the roller drive. The roller 05 is driven by the roller drive backwards to the start position until the light beam of the photocell 12 is interrupted again.

In all cases, instead of transmitting and receiving units and reflectors, the light beams can also be deflected, generated and / or received and / or deflected by separate transmitters and receivers and possibly mirrors.

LIST OF REFERENCE NUMBERS

01

Area of Automatic Roll Loading, Area of Roll Transport

02

reelstands

03

light Curtain

04

beam of light

05

role

06

Photocell, reflection photocell

07

beam of light

08

Transmitting and receiving unit; Transmitter; receiver

09

Reflector; Receiver, transmitter

10

-

11

alarming device

12

photocell

Claims (18)

1. Hazardous area protection for the roll transport area (01) to a reel changer (02) with a protective device acting without contact at access boundaries of the area, which can be deactivated for the retraction and/or delivery of a known object, and with an evaluation unit, the protective device being designed as a light grid (03), which comprises a number of light rays (04) running parallel to one another, characterized in that the evaluation unit has means for recording the sequence of the interruption of the light rays (04) on the retraction and/or delivery of any object and by means of this sequence recognizes a known object authorized for access to the hazardous area and deactivates the protective device in this case and in that the hazardous area protection additionally comprises a second protective device acting without contact, which is permanently active.
2. Hazardous area protection according to Claim 1, characterized in that the known object is a reel (05), a residual sleeve container or a driverless transport vehicle.
3. Hazardous area protection according to Claim 1, characterized in that the light rays (04) are evenly spaced from one another.
4. Hazardous area protection according to Claim 1, characterized in that the light rays (04) run horizontally.
5. Hazardous area protection according to Claim 4, characterized in that the surface of the light grid (03) is arranged inclined to the perpendicular.
6. Hazardous area protection according to Claim 1, characterized in that the light rays (04) run inclined to the horizontal.
7. Hazardous area protection according to Claim 1, characterized in that at least one light ray (04) of the light grid (03) running above the known object is permanently active.
8. Hazardous area protection according to Claim 1, characterized in that it furthermore comprises at least two photocells (06) for muting, which are connected to the evaluation unit.
9. Hazardous area protection according to Claim 1, characterized in that the hazardous area protection comprises at least two light rays (07) running diagonally to the longitudinal extent of the known object.
10. Hazardous area protection according to Claim 9, characterized in that the respective upper endpoint of the light rays (07) lies above the upper edge of the known object.
11. Hazardous area protection according to Claim 9, characterized in that the respective lower endpoint of the light rays (07) lies below the upper edge of the known object.
12. Hazardous area protection according to Claim 9, characterized in that the light rays (07) cross above the known object and are led past in their further course to the known object.
13. Hazardous area protection according to Claim 1, characterized in that the protective devices comprises a sensor for recording the dimensions of the known object.
14. Hazardous area protection according to one of Claims 1 to 13, characterized in that the known object is a reel (05) with a diameter of > 450 mm.
15. Hazardous area protection according to Claim 1 or 14, characterized in that the hazardous area protection comprises a photocell (12), which is arranged within the secured area and makes possible a positioning of the real (05) or a driverless transport vehicle in a starting position.
16. Hazardous area protection according to Claim 8, characterized in that objects provided with reflecting strips can be recorded by means of the at least two photocells (06).
17. Hazardous area protection according to Claim 16, characterized in that the objects are designed as a driverless transport vehicle or residual sleeve containers.
18. Hazardous area protection according to Claim 16, characterized in that two reflection photocells (06) are incorporated ahead of the light grid (03) and two reflection photocells (06) are incorporated after the light grid (03).

Images