EP2907921B1 - Barrier system - Google Patents

Description

The invention relates to an arrangement of 4 barrier systems for the alternate blocking and release of the passage or the passage of two intersecting roads or transport routes, of which one or at least twice as wide as the one or the other.

A recurring problem with barrier systems of various kinds is that the space available for the movement of the barrier boom can be very limited.

Various proposals have already been made for the use of barriers at entrances or passageways which are limited in their height, especially compared to their width.

By the DE 37 19 912 A1 is a boom known, which is pivotable in the vertical plane by 90 ° and consists of two sections which are hinged together at their one, adjacent ends. In the passageway blocking position, the entire barrier boom projects horizontally into this passageway and its two sections are in a mutually aligned position. When vertically swinging the boom 90 degrees from its passageway blocking position to its passageway-releasing position, the forward free-end portion of the barrier boom is disposed with respect to the rear driveable section by means of one along the drivable portion Chain drive in the vertical plane angled by 90 °, while he returns to the return-blocking position occupies the aligned with the drivable portion position when returning the barrier boom.

After EP 0937 820 B1 is the front portion of such a two-part barrier boom arranged by means of a hollow, drivable portion Cable in the vertical position of the barrier boom in the release position also in the vertical plane by 90 ° angled.

Such barrier trees are mainly used for the closure and clearance of transits with low altitude, for example, when entering underground parking garages. Especially when driving through with in relation to the low height significantly greater width of the passageway with such a barrier tree in its width can still shut off sufficiently and release. However, in the release position, the front projecting by 90 ° angled section still, albeit increased, into the passage, whereby the usable height of the already low entrance or entrance is further reduced, so that vehicles from a certain height or vehicles with Structures can not pass or retract.

By the DE 211 965 is a two hingedly interconnected sections existing boom known in which in the locked position of the boom of the front, the free end of the boom having portion is purely passively angled relative to the drivable portion in the horizontal plane when a vehicle with the barrier closed on the ascending the front section. This should prevent accidents, especially at railway crossings. A vehicle still located between the two barrier trees after the closure of both barrier trees of a railroad crossing can thus still leave this area.

It has already been proposed, in relation to their height wide passages or driveways to use a boom, with the passage or entrance can be locked in its entire width and the release of the passage or entrance in its entire length by 90 ° but is pivotable in a horizontal plane. However, the space available for this horizontal movement is also in most cases also limited and often insufficient.

By the DE 2 300 944 is a pivotable in a vertical plane barrier tree is known, which consists of two parts which are articulated at one end, ie kinkable, connected to each other. The one, rear section is hinged to a barrier post, the other, front section has the free end of the boom on. A support rod is hinged at one end to the barrier post and hinged at its other end to the front portion of the barrier boom; the articulation point of the support rod at the front portion of the barrier boom is spaced from the articulated connection between the front and rear portion of the barrier boom. When the barrier is closed, the two parts of the barrier boom are aligned with each other in the horizontal direction and the barrier boom is supported as a whole by the support rod in this position. When opening the barrier, the rear part of the barrier boom pivots in its pivot point on the barrier post by approximately 90 ° in a vertical plane upwards, while the front portion pivots in the joint of the two sections down, the support rod is taken in the movement. When the barrier is open, therefore, the rear portion of the barrier boom from the barrier post upwards while the front section appears bent down. This allows the barrier to be built lower in relation to the shut-off area.

By the US 2 137 193 A a barrier system is known, which can be pivoted from the passage of a road in the passage of a road to intersecting.

J Barrier systems have also been used in which the problem of the limited space available for the movement of a barrier boom has been solved by two barrier trees facing each other at the passage or at the passage, each of them passing the passage or the passage in its half Width can shut off and release.

An important area of application of barrier systems is the intersecting roads or roads, such as production lines in vehicle construction or baggage conveyor lines at airports. On production lines, the unidirectional assembly lines are interrupted at regular intervals by intersecting supply lines, on which the assembly parts are brought for the next assembly process. Also with luggage conveyor systems At airports, the conveyor routes are intersected at intervals by Interrupted feeder roads on which more luggage be brought. These are just two examples of such a field of application.

Such intersecting roads or roads must then be alternately locked in one direction and the other and released again. It is understood that here, too, e.g. in assembly halls, the space available for the movement of barrier trees is very limited. Systems are now known in which at the intersections four, opposing barrier trees are installed, which can be alternately against each other by 90 °, preferably in a horizontal plane, pivot, each individual barrier tree, the width of each part, preferably half, can shut off.

This has proven useful in cases where the two intersecting roads or paths have the same width. Even if one of the two roads has up to double the width of the other, the roads can still be completely closed in both directions with conventional barrier trees, if the length of a barrier tree is at most equal to the width of the narrower road; It must then be taken into account that when blocking the narrower road at the barrier trees, an overlap occurs. But if one of the two roads is more than twice as wide as the road crossing it, the wider road can no longer be completely closed off.

Object of the present invention is to provide a barrier system using suitable barrier trees, which can be used advantageously at intersecting roads or paths of significantly different width, which must be alternately locked or released in one direction and other, so that the Roads or paths in both directions can be completely blocked and released, it being noted that the usable space for the movement of one or more barrier trees here is also very limited in most cases.

This is achieved according to the invention with an arrangement of 4 barrier trees according to claim 1.

According to the invention, a barrier system with one horizontally from the passage of a street in the passage of the other road pivotable barrier tree is installed at the four corners of the intersecting streets; In this case, two of the diagonally opposite barrier systems each have one of a stretched position in its length foldable barrier tree and the other two, diagonally opposite barrier systems each have a conventional, rigid in its entire length barrier tree. The passage of the wider road can thus be closed with a foldable barrier boom in its extended position together with a barrier boom rigid in its entire length. The passage of the narrower street can be blocked with a barrier tree folded in its length together with a barrier boom rigid in its whole length. The use of foldable barrier trees significantly reduces the space required for their movement to alternately lock two intersecting roads.

Preferably, the foldable in their length barrier trees each consist of two sections, namely a front, the free end of the barrier boom having portion and a rear, connected to a drive device, drivable portion. These sections of each of these barrier trees may advantageously be connected together at their abutting ends by a four-bar linkage (joint with four degrees of freedom), and the front section having the free end of the respective barrier boom is then in the four-bar joint of a stretched section aligned with the drivable section Position in a folded back on the drivable portion position and back again pivotable.

The lengths of the barrier trees and their sections can be advantageously chosen so that the foldable in their length barrier trees in their extended position, ie with aligned front and drivable sections cover the passage of the wider road by more than half and the barrier barriers, which are rigid in their whole length, cover the remaining part of the passage of the broader road. It can be so completely shut off the streets in both directions and release. When blocking the narrower road results in an overlap of the barrier trees, which is not disturbing. It is an advantage that no parts of the barrier trees protrude into the shared passage.

According to a preferred embodiment, the four-bar linkage of each foldable barrier tree has a connection for the front, free end of the barrier boom section of the barrier boom and a connection for the rear, drivable portion of the barrier boom and the connection of the front portion is with respect to the terminal of drivable portion pivotable about a central axis of the four-bar linkage, until it is parallel to the connection of the drivable portion. In addition, the four-bar linkage has two levers which are pivotally connected together at their one ends about a common axis; the one lever is pivotable with its second end about an axis with the connection of the drivable portion and the other lever is connected at its second end about an axis pivotally connected to the terminal of the front portion of the barrier boom. The hingedly connected to the connection of the drivable portion lever has a point of application for a parallel to the driven portion arranged and together with this pivotable guide rod. With such a joint, the front portion can be folded back by practically 180 °, ie in a parallel position on the drivable portion.

If the length of the front portion having the free end of the barrier boom is equal to the length of the drivable portion, the length of the folded barrier boom may be one-half shorter than the overall length of the barrier boom in its extended position; He is then correspondingly space-saving in his movement.

The front, the free end of the barrier boom having portion may also be shorter than the drivable section, if, for example, the local conditions make it seem advantageous.

Fig. 1

eine perspektivische Darstellung einer Schrankenanlage mit einem zweiteiligen, faltbaren Schrankenbaum in seiner einen Weg sperrenden Stellung, der bei einer erfindungsgemäßen Schrankenanlage vorteilhaft einsetzbar ist,

Fig. 2

eine perspektivische Darstellung einer Schrankenanlage nach Fig. 1 mit dem Schrankenbaum in seiner einen Weg freigebenden Stellung,

Fig. 3

eine perspektivische Darstellung einer Schrankenanlage nach Fig. 1 und 2 mit dem Schrankenbaum in einer Zwischenstellung,

Fig. 4

die Draufsicht auf die Schrankenanlage gemäß Fig. 1,

Fig. 5

die Draufsicht auf die Schrankenanlage gemäß Fig. 2,

Fig. 6

die Draufsicht auf die Schrankenanlage gemäß Fig.3,

Fig. 7

die perspektivische Ansicht eines die beiden Abschnitte des zweiteiligen Schrankenbaums nach Fig. 1 bis Fig. 6 verbindenden Gelenks,

Fig. 8

die Draufsicht auf ein zum Teil geöffnetes Gelenk gemäß Fig. 7 in der Stellung, die es einnimmt, wenn beide Abschnitte des Schrankenbaums miteinander fluchten,

Fig. 9

die Draufsicht auf das Gelenk gemäß Fig. 8 in der Stellung, die es einnimmt, wenn die Abschnitte des Schrankenbaums, während ihrer Bewegung in einem Winkel von 90° zueinander stehen,

Fig. 10

die Draufsicht auf das Gelenk gemäß Fig. 8 in der Stellung , die es einnimmt, wenn der eine (vordere) Abschnitt des Schrankenbaums ganz auf den anderen (hinteren) Abschnitt zurückgefaltet ist und

Fig. 11, Fig. 12 und Fig. 13

schematisch den Einsatz von Schrankenbäumen an zwei sich kreuzenden Straßen deutlich unterschiedlicher Breite, deren Durchfahrt abwechselnd zu sperren und freizugeben ist.

The invention will be described in more detail below with reference to the attached drawings; show it:

Fig. 1

a perspective view of a barrier system with a two-part folding barrier tree in its one-way blocking position, which is advantageously used in a barrier system according to the invention,

Fig. 2

a perspective view of a barrier system after Fig. 1 with the barrier tree in its one way releasing position,

Fig. 3

a perspective view of a barrier system after Fig. 1 and 2 with the barrier boom in an intermediate position,

Fig. 4

the top view of the barrier system according to Fig. 1 .

Fig. 5

the top view of the barrier system according to Fig. 2 .

Fig. 6

the top view of the barrier system according to Figure 3 .

Fig. 7

the perspective view of the two sections of the two-piece barrier boom after Fig. 1 to Fig. 6 connecting joint,

Fig. 8

the top view of a partially open joint according to Fig. 7 in the position it occupies when both sections of the barrier boom are aligned with each other,

Fig. 9

the top view of the joint according to Fig. 8 in the position it occupies when the sections of the barrier boom are at an angle of 90 ° to each other during their movement,

Fig. 10

the top view of the joint according to Fig. 8 in the position it occupies, when one (front) section of the barrier boom is folded back completely onto the other (rear) section and

11, 12 and 13

schematically the use of barrier trees on two intersecting streets of significantly different widths, the passage of which is to be alternately locked and released.

Fig. 1 shows a barrier system with a barrier boom 1 in its one-way blocking position. The barrier boom 1 consists of a front, the free end of the barrier boom 1 having portion 1a and a rear portion 1b, which at its one end to the second end of the portion 1a by a so-called four-bar linkage 2 (a joint with four degrees of freedom) is. At its end remote from the joint 2 end 3 of the rear portion 1 b is connected to a drive device, not shown in detail, which may be housed in a barrier housing 4 and with the barrier boom 1 in a conventional manner by 90 ° in his way releasing Position and back again is pivotable; in the illustrated embodiment, the barrier boom 1 is advantageously pivotable in a horizontal plane by 90 °. Along the rear, drivable portion 1 b of the barrier boom 1 extends a guide rod 5, which is pivotally mounted with its one end 5a on the barrier housing 4 together with the drivable portion 1b by 90 ° in a horizontal plane and the other end 5b on a Arm of the four-joint 2 attacks, see also Fig. 3 , The drivable end connected to the drive device 3 of the drivable portion 1 b is not only horizontally pivotable by 90 ° by the drive device, but also on the barrier housing 4 in the longitudinal direction of the section 1 b by a certain amount displaceable (see End 3 in Fig. 1 and Fig. 2 ).

To the barrier boom 1 from its blocking the position according to Fig. 1 according to his position of release Fig. 2 to move, it is pivoted at its driven end 3 by the drive device by 90 ° horizontally. In this movement, the guide rod 5 is taken, it pivots at its end connected to the barrier housing 4 end 5a by 90 °, with its other end 5b so acts on a lever of the four-bar 2, that the drivable end 3 of the drivable portion 1b of the barrier boom 1 on the barrier housing 4 in the longitudinal direction of the four-bar linkage 2 is moved to; Thus, the four-bar linkage 2 (see below) is moved such that the front portion 1 a of the barrier boom 1 is folded back to the drivable portion 1 b, ideally by 180 ° and both sections 1 a and 1 b occupy a parallel or nearly parallel position to each other. The term "parallel" or the term "180 °" are not strictly geometrical to understand, it may be practical or manufacturing engineering deviations. Fig. 3 shows an intermediate position, which occupies the barrier boom 1 during this movement. It is thus achieved that the space required for the movement of the barrier boom 1 as a whole and for the path releasing position is significantly reduced; if the two sections 1a and 1b have the same length, the length of the folded barrier boom 1 according to Fig. 2 approximately equal to or nearly equal to half the total length of the elongated barrier boom 1 according to Fig. 1 be. It is also possible in principle to make the front section 1 a having the free end of the barrier boom 1 shorter than the drivable section 1 b. The length of the folded barrier boom 1 will then be equal to a larger fraction of the total length of the elongated barrier boom 1.

To clarify are in the FIGS. 4 to 6 the positions of the barrier boom 1 in its movement out of the path blocking position according to Fig.1 and Fig. 4 about the intermediate position according to Fig. 3 and Fig. 6 according to his position of release Fig. 2 and Fig. 5 assumes, also reproduced in plan view. It is also clear to recognize the change in position of the driven end 3 of the drivable portion 1b and the end 5a of the guide rod 5 on the barrier housing 4.

Fig. 7 2 shows the connections 6a and 6b for the sections 1a and 1b of the barrier boom 1. The actual hinge 2 is located between an upper and a lower protective plate 7 and is in this Presentation of the upper protective plate 7 largely covered. The protective plates 7 are parts of the terminals 6a and 6b or are firmly connected thereto. Fig. 8 shows a plan view of the four-bar linkage 2 with the upper protective plate 7 removed and aligned portions 1 a and 1 b of the barrier boom 1. The terminal 6a for the front portion 1a of the barrier boom 1 is rotatably supported with respect to the terminal 6b for the rear, drivable portion 1b about a central axis of rotation 8 of the four-bar joint 2. An approximately semicircular curved lever 9 is connected at its one end spaced from the central axis of rotation 8 with the terminal 6b of the drivable portion 1 b about an axis 10 rotatably connected. With the terminal 6a for the front portion 1 a, a second curved lever 11 at its one end spaced from the central axis of rotation 8 about an axis 12 rotatably connected. The other two ends of the levers 9 and 11 are connected to each other rotatable about a common axis 13. At the pivotally connected to the terminal 6b lever 9 engages at a point 14, the guide rod 5, which is symbolically represented here by an arrow 5.

If in the extended blocking position of the barrier boom 1 (see also Fig. 1 and Fig. 4 ), ie in mutually aligned sections 1a and 1b, the barrier boom 1 by acting on its drivable portion 1b drive device in the example described here in the direction of the arrow P (s. Fig. 4 ) is pivoted horizontally, the guide rod 5 is taken along in this movement, it exerts via the point of action 14 a train on the hinged to the terminal 6b lever 9; the lever 9 rotates about its axis 10 at the terminal 6b and takes with it on the common axis 13 hingedly connected lever 11 which is hinged at its other end to the terminal 6a, so that it follows the movement by to rotate about the common axis 13 of the two terminals 6a and 6b. Fig. 9 shows the positions of the individual parts of the four-bar linkage 2 in an intermediate position of the terminals 1a and 1b and thus the front portion 1 a and the rear, drivable portion 1 b of the barrier boom 1 after rotation on the four-bar 2 by 90 °, causing a pivoting of the barrier boom 1 or its drivable portion 1 b by approximately 45 ° in the direction of arrow P corresponds (s. Fig. 6 ). The boom 1 and its drivable portion 1 b is further driven in the direction of the arrow P, and the guide rod 5 continues to exercise its train on the point 14 on the lever 9, this continues to rotate about its axis 10 at the terminal 6b and takes the Lever 11 in its movement with. The lever 11 transmits the movement on the articulated connection 6a with him and this follows the movement by further rotating with the entrainment of the front portion 1a of the barrier boom 1 about the central axis of rotation 8 in the direction of arrow Q (s. Fig. 6 ), until finally in the final position according to Fig. 10 is parallel to the terminal 6b, according to which the front portion 1a is folded back by 180 ° or approximately 180 ° to the drivable portion 1b, so that both sections 1 a and 1 b according to Fig. 5 parallel to each other, which corresponds to a pivoting of the barrier boom 1 or its drivable portion 1 b on the barrier housing by 90 ° (s. Fig. 2 and Fig. 5 ); after that the way or the previously closed passage is given free.

It is understood that in a return movement of the barrier boom 1 in its extended locking position according to Fig. 1 and Fig. 3 the movements take place at the four-bar 2 in the opposite direction.

The FIGS. 11 to 13 show the inventive use of the barrier boom on two intersecting paths or roads, such as a production line and a supplier, the one road 16, for example, the supply line 16, significantly wider, namely more than twice as wide as the intersecting road 15, for example Production line 15. Both roads 15 and 16 must be alternately shut off and released, on the one hand to run the production and on the other hand to be able to supply required mounting parts at certain points. Because the room height is usually quite low at such production sites, vertically pivoting barrier trees are usually unsuitable for such applications. This problem can be avoided by using horizontally swiveling barrier trees. The two roads must be adapted to their purposes and therefore often have a different width. If the wider road is twice as wide as the narrower road, both can be completely blocked in both directions if a conventional barrier with a rigid, horizontally swinging barrier is installed at the four corners of the intersection, and the barrier trees are used to block or clear a road be pivoted against each other by 90 °. In case of blocking the narrower road may partially overlap the barrier trees.

At the in Fig. 11 . Fig. 12 and Fig. 13 In this example, the one road 16 is more than twice as wide as the narrow road 15. Since a rigid, conventional barrier boom may in no case be longer than the narrower road 15 is wide, in such a case the wider road 16 may be rigid with conventional ones Barrier trees are no longer completely blocked, it would then always a more or less wide gap between them between the free ends of the barrier trees. This problem can be remedied by means of barrier beams 1 as described above.

Fig. 11 shows two intersecting roads 15 and 16 of different width, of which the wider 16 is more than twice as wide as the narrow 15. At each of the four corners of the intersection a barrier system 17 is installed with a horizontally pivotable by 90 ° boom. The one two diagonally opposite barrier systems 17 each have a forth conventional, inherently rigid barrier boom 18; the length of the two barrier trees 18 is preferably less than the width of the narrow street 15, but at most equal to the width of the narrow street 15. The other two diagonally opposite barrier systems 17 each have a barrier boom 1 which, as described above, is preferably foldable up to its half length. Fig. 11 shows the system in the state in which the wider road 16 is completely locked in both directions and the narrow road 15 is released in both directions. The two foldable barrier trees 1 are in their stretched state, in which their two sections 1 a and 1 b aligned with each other, so they cover the width of the road 16 for the greater part, for example, to 2/3 of the width, while the two conventional, rigid in their length barrier trees 18 of the directly opposite barrier systems 17 cover the smaller part, in the example 1/3 of the width of the wider road 16. If now the wider road 16 is released and the narrow road 15 are blocked, then all four barrier trees 1 and 18 are pivoted by 90 ° horizontally in the direction of the narrow road 15, the sections 1a of the two foldable barrier trees 1, as described above, is folded back in the four-bar 2 on the respective drivable portion 1 b until the sections 1a are parallel or nearly parallel to the drivable sections 1 b of the barrier trees 1. The barrier trees 1 and 18 then take the positions according to Fig. 12 in which the wider road 16 is released and the narrower road 15 is locked. The overlap of the barrier trees 1 and 18 in this position does not bother. To again block the wider road 16 and give the narrow street 15, the barrier trees 1 and 18 are pivoted in the opposite direction by 90 °, with the foldable barrier trees 1 unfold again and their extended position according to Fig. 11 taking.

Fig. 13 shows the barrier system according to Fig. 11 and 12 in an intermediate position of the barrier trees 1 and 18 after pivoting about 45 ° in one or the other direction.

LIST OF REFERENCE NUMBERS

1

boom

1 a

front section of the barrier boom

1 b

rear, drivable section of the barrier boom

2

Joint, four-jointed joint

3

drivable end of section 1 b

4

barrier housing

5

guide rod

5a

End of the guide rod on the barrier housing

5b

End of the guide rod at the joint

6a

Connection Section 1 a at the joint

6b

Connection section 1 b at the joint

7

protection plates

8th

central axis of rotation

9

Lever at port 6b

10

axis

11

Lever at port 6a

12

axis

13

common axis

14

attackpoint

15

narrow street

16

wide street

17

barriers

18

conventional barrier boom

Claims (9)

1. Arrangement consisting of 4 barrier systems for alternately shutting and opening the vehicle entrance or pedestrian entrance of two lines or transport paths which cross one another and of which one is at least twice as wide as the other, characterized in that, on the four corners of the lines (15, 16) which cross one another, in each case one barrier system (17) with in each case one barrier boom (1, 18) which can be pivoted horizontally out of the vehicle entrance of one line (15) into the vehicle entrance of the other line (16) is installed, in that two of the barrier systems (17) which lie diagonally opposite one another have in each case one barrier boom (1) which can be folded lengthwise from an elongate position, and the two other barrier systems (17) which lie diagonally opposite one another have in each case one conventional barrier boom (18) which is rigid over its entire length.
2. Arrangement consisting of 4 barrier systems for alternately shutting and opening the vehicle entrance or the pedestrian entrance of two lines or transport paths which cross one another and of which one is more than twice as wide as the other, characterized in that, on the four corners of the lines (15, 16) which cross one another, in each case one barrier system (17) with in each case one barrier boom (1) which can be pivoted horizontally out of the vehicle entrance of one line (15) into the vehicle entrance of the other line (16) is installed, and in that the said four barrier systems (17) have in each case one barrier boom (1) which can be folded lengthwise from an elongate position.
3. Arrangement according to Claim 1 or 2, characterized in that the barrier booms (1) which can be folded lengthwise consist in each case of two sections (1a) and (1b), namely of a front section (1a) which has the free end of the barrier boom (1) and a rear drivable section (1b) which is connected to a drive device, in that the sections (1a and 1b) of each of these barrier booms (1b) are connected to one another at their ends which abut one another by way of a four-bar linkage (four-member coupling linkage with one degree of freedom) (2), and in that the front section (1a) which has the free end of the respective barrier boom (1) can be pivoted in the four-bar linkage (2) from an elongate position which is aligned with the driveable section (1b) into a position which is folded back onto the driveable section (1b) and back again.
4. Arrangement according to Claim 1 or 3 if the latter is dependent on Claim 1, characterized in that the barrier booms (1) which can be folded lengthwise cover more than half of the vehicle entrance of the wider line (16) in their elongate position, that is to say with sections (1a) and (1b) which are aligned with one another, and the barrier booms (18) which are rigid over the entire length cover the remaining part of the vehicle entrance of the wider line (16).
5. Arrangement according to Claim 2 or 3, characterized in that the barrier booms (1) which can be folded lengthwise cover half of the vehicle entrance of the wider line (15) in their elongate position, that is to say with sections (1a) and (1b) which are aligned with one another.
6. Arrangement according to Claim 2 or 3 if the latter is dependent on Claim 2, characterized in that the barrier booms (1) which can be folded lengthwise of two barrier systems (17) which lie diagonally opposite one another cover more than half of the vehicle entrance of the wider line (16) in their elongate position, that is to say with sections (1a) and (1b) which are aligned with one another, and the barrier booms (1) which can be folded lengthwise of the two other barrier systems (17) which lie diagonally opposite one another cover the remaining part of the vehicle entrance of the wider line (15).
7. Arrangement according to Claim 3, characterized in that the four-bar linkage (2) of each foldable barrier boom (1) has a connector (6a) for the front section (1a) of the barrier boom (1), which section (1a) has the free end of the barrier boom (1), and a connector (6b) for the rear, driveable section (1b) of the barrier boom (1), and the connector (6a) of the front section (1a) can be pivoted about a central axis (8) of the four-bar linkage (2) in relation to the connector (6b) of the driveable section (1b) until it lies parallel to the connector (6b) of the driveable section (1b), in that the four-bar linkage (2) has two levers (9 and 11) which are connected to one another at their one ends such that they can be pivoted about a common axis (13), in that one lever (9) is connected by way of its second end to the connector (6b) of the driveable section (1b) such that it can be pivoted about an axis (10), and the other lever (11) is connected by way of its second end to the connector (6a) of the front section (1a) of the barrier boom (1) such that it can be pivoted about an axis (12), and in that the lever (9) which is connected in an articulated manner to the connector (6b) of the driveable section (1b) has a point of action (14) for a guide rod (5) which is arranged parallel to the driveable section (1b) and can be pivoted together with the latter.
8. Arrangement according to Claim 3, characterized in that the length of the front section (1a) which has the free end of the barrier boom (1) is equal to the length of the driveable section (1b).
9. Arrangement according to Claim 3, characterized in that the front section (1a) which has the free end of the barrier boom (1) is shorter than the driveable section (1b).

Images