EP0937824B1 - Protection device for locks - Google Patents

Abstract

The device is formed by a beam to absorb impact forces applied by a ship. The beam (5) moves in parallel guides (11,12) on either side of a shipping channel (1). Hydraulic cylinders (14) to absorb the impact move parallel to the guides. The guides are effective for horizontal and/or vertical guidance of the beam. A brake unit to reduce kinetic energy has shock absorbers (14), directed horizontally against the beam on either side of the channel. The shock absorbers are conventional industrial absorbers with biologically degradable hydraulic fluid.

Description

The invention relates to a shock protection device for locks, comprising a as a safety catch designed to absorb impact forces Ship, a braking device for the reduction of kinetic energy of the ship with hydraulic cylinders, means for transferring the impact forces to the Braking device and means for removing the beam from the fairway of the ship, the bar being guided on both sides of the fairway and the Hydraulic cylinders are movable with a stroke parallel to the guide.

Such a shock protection device for Schlensen is known from DE-B-28 31 695.

The increasing traffic load on inland waterways with larger ones and faster ship units leads to an increased risk to the Lock gates by entering and not timely to stop brought ships are increasingly approached. The danger is especially large when entering from upper water. When arriving from Underwater there is less danger of door damage given because the water pressure acts against the gates. Also are for this If the entry resistance is greater due to the lower water depth.

The severity of the accidents has demonstrably increased over the years and the resulting business interruptions at locks of each few days to several weeks lead especially on waterways with individual locks to serious disabilities and breakdowns for shipping.

• Fehler beim Abstoppen des Fahrzeuges in der Schleuse
• Fehler beim Bedienen der Schleuseneinrichtungen
• Fehler beim Festmachen und sonstigen Unachtsamkeiten
• Versagen der Schleuseneinrichtungen
• Versagen der Trossen

The gate approaches can have the following causes:

• Error stopping the vehicle in the lock
• Error operating lock systems
• Mooring and carelessness errors
• Failure of the lock facilities
• Failure of the hawser

The evaluation of statistical documents from the Federal Ministry of Transport led to the result that about 60% of all Torvic havens on human Failure are attributable. For these reasons, are regulatory Measures have been taken to prevent accidents as far as possible.

Shock protection devices are not intended to prevent lock gates from being damaged Protect ships in time and thus block shipping and expensive repairs to the lock gates or even environmental disasters avoid. In DE-Vomorm 19703 of July 1993, principles for the Security systems set in locks on inland waterways. The Under the gate of the lock, a shock protection device should act like a chamber received against moving the gate. The height of the impact protection device above Oberwasser is based on those traveling on the waterway Ships. Such a shock protection device should be designed so that the fully loaded ship does not slide under the structure and the empty ship with Do not place the flat undercut bow on the impact protection device can. With changing water levels, height adjustable Shock protection devices provided. Likewise, the work capacity is Establishment taking into account the kinetic energy of the incident Ship unit and the impact speed of the ship set. The Working capacity is 1 Nm, the impact speed is 1.1 m / s start and is completely from the damping elements of the Shock protection device, e.g. Hydraulic cylinder, elastomer buffer.

Lock lock systems known from practice have a catch element either ropes or beams or both in combination. The shock protection device for lock gates which is known from DE-B-28 31 695 is with a across the clear opening of a lock chamber, the shock - absorbing catch caused by a ship, which by means of appropriate ropes or chains over the loose pulleys of a pulley, whose fixed roles are anchored on the outside, with a braking device connected and which with a separate drive for lifting and Lowering the catch member is equipped with a bumper beam as a catch member provided, which is suspended on cables connected to the braking device and the movement caused by the shock with both ends in horizontal niches in the side walls of the Lock chamber are arranged. This flexible, i.e. laterally movable Bumper beam is made in a horizontal plane parallel to the plane of the Guide arranged hydraulic cylinder, the end of which with the bumper beam connected via the side, braked.

• komplizierte Mechanik bzw. Hydraulik; dadurch wird die Unzuverlässigkeit und Störanfälligkeit erhöht;
• der Schiffsstoß wird durch gerade wirkende Kräfte nicht optimal abgefangen; es sind aufwendige Widerlager erforderlich oder die Tore der Schleuse können bei starken Stößen wegen der Kopplung mit den Balken beschädigt werden;
• es wirken enorme Querkräfte, die einen aufwendigen Baukörper erforderlich machen;
• es müssen längere Bremswege einkalkuliert werden (ca. 4 m), die die Nutzung der Schleusenkammerlänge einschränken;
• hoher Wartungsaufwand.

The pressure medium displaced by the stroke movement of the cylinder is guided in a bladder accumulator, which is also equipped with a blow throttle valve for blowing off the oil into an oil tank when the stroke path of the cylinder is exceeded. In the following, only systems with beams are considered as shock protection. The prior art has major disadvantages:

• complicated mechanics or hydraulics; this increases the unreliability and susceptibility to faults;
• the impact of the ship is not optimally absorbed by just acting forces; elaborate abutments are required or the gates of the lock can be damaged in the event of strong impacts due to the coupling with the beams;
• there are enormous transverse forces that require a complex structure;
• longer braking distances must be taken into account (approx. 4 m), which limit the use of the lock chamber length;
• high maintenance effort.

From DE-OS 163 41 07 a shock protection device with high energy destruction for lock gates is known, whose impact beam, which is movable in the direction of the lock axis and acts on a horizontal plane, acts on a hydraulic damping means which destroys the energy of the ship shock in cooperation with a pressure relief valve and hydropneumatic accumulator. The shock beam is articulated at both ends of its hydraulic cylinders, the pressures of which are controlled by a pressure relief valve, the opening pressure of the pressure relief valve being hit by an eccentric impact of the ship and the resulting inclination of the shock beam by mechanical or hydraulic means so that the Piston forces of the hydraulic cylinders correspond to the forces acting on the ends of the bumper beam. This requires complex control of the pressure relief valves arranged on the two damping devices. Since the two systems on both sides of the beam are not connected to one another, attempts are made to keep the system in balance by means of the articulation of several cylinders on each side by means of the lever forces acting differently when the ship hits the bar.
The hydraulic cylinders are coupled to one another and ultimately mounted on the inner wall of the lock via a cylinder. As a result, it cannot be avoided that the inner wall of the lock is subjected to very high loads and that repairs encounter great difficulties. In addition, the design of the guide joints for the hydraulic cylinders is complicated and the overall system is maintenance-intensive.

From DE-OS 27 28 704 a shock protection device for lock gates is known with a bar located across the lock and equipped with a safety gear and shock absorbing means, the shock absorbing means, for example a rope and wood attached to the beam with the line of action extending transversely to the lock wall and are operatively connected to the catching device on both sides, the catching device essentially consisting of a rope arranged in front of the beam, which is freely stretched along the beam and is provided on the back of the beam with pulse-destroying hydraulic cylinders. The bar itself can be swiveled in the lock wall in elements called the tear-off stool
anchored, the coupling elements between the beam and the chamber wall decoupling at very high impacts, so that the beam is no longer in contact with the chamber wall. The actual catching device essentially consists of a rope, the bar only representing the connection between the left and right ends of the rope and having to absorb the reaction forces of the damping means. Since the rope lies directly against the beam in the event of a major impact, an even distribution of the forces is not possible and there is a risk that the beam will be overloaded on one side and slide out of its abutment.

Finally, from DE-OS 20 41 083 a shock protection device for lock gates, especially for lifting and lowering gates using shock beams as shock absorbing means is known, in which the absorbed impact energy can be destroyed by throttling in hydraulic cylinders or by friction elements, these beams with the Gates are connected and can give way in the direction of impact and the energy-destroying agents can be coupled to the construction work on the lock masonry. These energy-destroying parts can be hydraulic cylinders.
A disadvantage of these systems is the coupling of the shock absorbing means to the lock gate, which means that considerable forces can be introduced into the lock gate and its abutment. The bumper beam is guided by appropriate storage on the lock gate and is accordingly sensitive to an inclined position or an asymmetrical impact.

Ships and other masses contain kinetic energy that increases with the square of the speed. When these masses are braked, forces occur that increase with the energy content.
In order to eliminate these destructive forces, dampers based on rubber, springs or air buffers are often used, but they are not satisfactory because they only store energy, develop a progressively increasing deceleration force with high peaks and permit little or no regulation. Even hydraulic brake cylinders of the usual type do not bring the desired success, since they suddenly oppose a high counterforce when the mass hits, which makes the method of operation very hard and the stress on the ship extremely high.

From the brochure "Industrial Shock Absorber" ACE shock damper GmbH, Langenfeld, DE, 6/97 hydraulic cylinders are known as shock absorbers be used, hydraulic oil by loading the piston rod displaced and is absorbed by an absorber element. Within preselectable types / load ranges can be a constant Delay of a mass can be effected. A spring sets the piston rod after the impact has subsided.

Starting from DE-B-28 31 965, the invention is the problem based on an automatic safety system with beams as shock protection for To provide watercraft in locks, which on a much simplified principle. Another problem is that the Functionality of the security system maintenance-free for a longer period guaranteed and the installation and operation of such a system essential is made more cost-effective. The legal requirements according to DE regulations are to be considered.

According to the invention, the problem is solved by the features of claim 1 solved. Further developments of the invention are covered in the subclaims.

In the impact protection device for locks, the beam is guided in parallel guides on both sides of the fairway and the hydraulic cylinders are movable with a stroke parallel to the guide.
Fairway is understood as the width of water that can be taken up by the ship and the water layer determined by its depth.
The brake device constructed in this way, with at least one on both sides of the fairway, directed horizontally against the beam and against the direction of impact of the shock forces, known per se in the design, enables the energy of the moving masses to be reduced linearly and the required deceleration force to be distributed uniformly over the entire braking distance to distribute.
Instead of the ACE type shock absorbers, similar dampers can of course be used, or a system with shock absorbers can be used, which in the event of an impact against the beam then stores the braking energy and uses it to reset the system.

However, it is ensured that the guide is in operative function in the horizontal and / or vertical stroke of the beam in the impact protection position. The latter is particularly the case when a ship's bow, for example, moves under the beam and tries to push it up. For this reason, corresponding guide members are arranged both above and below the bar. Conversely, the bow of a ship can of course run over the beam and try to push it down; this is prevented by lower guides.
Furthermore, the beam is mounted in such a way that it is removed from the fairway of the ship when the lock is opened by lowering by means of a hydraulic cylinder, spindle lifting element or a rack and pinion gear with a corresponding drive.

To avoid uneven loading of the shock absorbers, particularly in the case of very wide locks, which are also used by narrow ships, it can be provided that the ends of the beam are designed as a joint head, so that there is no inclination of the beam within the guides.
It is provided that after lowering the bar or for lowering the bar, a switch passes through at its ends, which releases it from horizontal movement into vertical movement.
It is also proposed according to the invention that an industrial shock absorber known per se is now used as a lifting damper of the beam, this industrial shock absorber preferably being filled with biodegradable hydraulic fluid, such as bio-oil or alcohol, for example glycol, in order to rule out environmental problems from the outset.
According to the invention, the energy of the moving mass is reduced linearly and the required deceleration force is evenly distributed over the entire braking distance. This results in a constant deceleration with the shortest possible braking time and the smallest possible braking force.

• die Schiffsgeschwindigkeit bzw. die bewegte Masse könnte um 80 % bis zu 100 % höher werden;
• die Schiffsbelastung wird um 70 - 80 % gesenkt;
• die Bremszeit könnte um 60 - 70 % gekürzt werden.

The positive consequences of using the industrial damper and the advantages of this shock protection system are:

• the ship's speed or the moving mass could increase by 80% up to 100%;
• the ship's load is reduced by 70-80%;
• the braking time could be reduced by 60-70%.

The well-known industrial dampers, for example of the ACE type, are self-contained hydraulic elements with a variety of Throttle openings. When the shock absorber is applied, the piston axially pressed into the shock absorber. The hydraulic oil that is in front of the Piston is displaced through all throttle openings at the same time. The number of active strokes increases in proportion to the stroke that is moved Throttle openings. The entry speed is inevitably constant lower. The dynamic pressure in front of the piston remains during the entire stroke. Thus, the same counterforce acts during the total stroke (constant linear deceleration and optimal solution to brake the hull). That displaced by the piston rod Hydraulic oil is compensated by an absorber in an elastomer. An im Piston built-in check valve and a compression spring are used for automatic return of the piston.

• Stoß- bzw. Bremsbalken;
• hydraulisches Stoßdämpfermodul mit dem speziellen, modifizierten Dämpfersystem und entsprechend konstruktiv umgesetzter Peripherie wie Führungen u.a.;
• Schlitten und Hubeinrichtung für Balken;
• Verankerungseinrichtung der Bremseinrichtungen und Balken beidseits des Fahrwassers.

The dampers are connected to the overall security system. By using organic oils, environmental problems are avoided and / or the risk of reduced functionality at temperatures around freezing is reduced. An automatic security system on a hydraulic basis has been constructed from the following individual components:

• Bumper or brake beam;
• hydraulic shock absorber module with the special, modified damper system and correspondingly implemented peripheral equipment such as guides etc.
• Carriage and lifting device for beams;
• Anchoring device for the braking devices and beams on both sides of the fairway.

• Bremsweg max. 1 m;
• max. Masse 1, 400 to oder größer;
• max. Geschwindigkeit des Schiffes 0,8 m/s.

Dabei wird die Wirkung so umgesetzt, daß die parallel angeordneten Dämpfersysteme je nicht über 50 % pro Hub ausgelastet werden.At least the following backup parameters are realized:

• Braking distance max. 1 m;
• Max. Mass 1, 400 tons or larger;
• Max. Speed of the ship 0.8 m / s.

The effect is implemented in such a way that the damper systems arranged in parallel are not used to more than 50% of each stroke.

To achieve this functionality, the following general problems had to be solved:
In order to assess the effectiveness of a shock protection system in practical lock operation, the energy values of the ships entering the lock of Oberwasser have been compared with the working capacity of the shock protection system.
Force effects were calculated, with special attention to situations when ships do not hit the center of the bumper beam. The system is designed in such a way that a lateral power surge can also be absorbed without complications on the basis of the damping principle described.
An automatic system is additionally integrated in that a targeted pressure build-up in a nitrogen bubble, which causes the damping elements and / or the beam lifting device to extend again, is achieved. The energy of the ship shock and / or the gain in potential energy when lowering the beam under the fairway can be returned in a weakened form. This design is known per se from the prior art.
Despite the unfavorable weather conditions, the shock absorber used is permanently functional without maintenance. The system is improved by special surface treatments (eg ceramic or metal powder coatings), in particular also by using solid lubricants.
In any case, the specialist takes the material selection into account in order to achieve resistance to alkali, acid or frost.

The carriage for guiding the beam is designed so that a Breaking out upwards is excluded and when loaded a even horizontal guidance is ensured. With one-sided loads the system will surely be able to stop the ship. The If necessary, shock absorbers are designed redundantly and / or the beam receives a joint head.

• wesentlich vereinfachte mechanische und hydraulische Lösung für die Sicherungsaufgaben durch Wegfall der Hydraulikaggregate, Ventiltechnik im Dämpfungsbereich u.a.;
• Substitution der aufwendigen und komplizierten mechanischen und hydraulischen Strukturen und damit wesentliche Verminderung der Querkräfte;
• Sicherung einer konstanten Bremskraft durch den Einsatz von für diese Zwecke neuartigen Stoßdämpfern;
• Gewährleistung einer Automatik durch selbständig wieder ausfahrende Stoßdämpfer nach Schiffsstoß durch Feder oder Druckspeicher;
• Wartungsfreiheit gekapselte Stoßdämpfer und einfache Führungen.

Overall advantages of the invention are.

• significantly simplified mechanical and hydraulic solution for the safety tasks due to the elimination of the hydraulic units, valve technology in the damping area and others;
• Substitution of the complex and complicated mechanical and hydraulic structures and thus a substantial reduction in the lateral forces;
• Ensuring a constant braking force through the use of new shock absorbers for this purpose;
• Guarantee of an automatic system by automatically retracting shock absorbers after ship impact by spring or pressure accumulator;
• Encapsulated shock absorbers and simple guides are maintenance-free.

In summary, it can be estimated that the benefits for the Lock operator a cost reduction by min. 50% on installation and one substantial reduction of operating costs through freedom from maintenance and automatic functionality with higher security parameters through the constant braking force means.

Fig. 1

Eine erfindungsgemäße Vorrichtung in Draufsicht als Vergrößerung der Schleusensituation in Fig. 4 auf einer Fahrwasserseite;

Fig.2

die Vorrichtung gemäß Schnitt A-A in Fig.4 und Fahrwasser-Ansicht zu Fig.2;

Fig.3

eine Vorderansicht der Vorrichtung gemäß Fig.2 aus Richtung einer Stoßkraft;

Fig.4

eine Draufsicht auf ein Schleusentor mit Stoßschutzvorrichtung;

Fig.5

eine zweite Version der Erfindung in perspektivischer Sicht.

The invention will be explained in more detail with the aid of a schematic drawing. Show it:

Fig. 1

A device according to the invention in plan view as an enlargement of the lock situation in FIG. 4 on a fairway side;

Fig.2

the device according to section AA in Figure 4 and fairway view to Figure 2;

Figure 3

a front view of the device of Figure 2 from the direction of an impact force;

Figure 4

a plan view of a lock gate with shock protection device;

Figure 5

a second version of the invention in perspective.

The same or similar parts are identified below with identical reference numerals Mistake.

Fig. zeigt den Balken 5 mit durch Bolzen 10 (Fig.3) gehaltenem Gelenkkopf 8 und vorgeflanschtem Schlitten oder Rad 9. In der Kaverne 20 ist eine obere Führung 11 und eine untere Führung 12 für den Schlitten 9 zu sehen, die den Schlitten parallel zu dem Hub HS des Stoßdämpfers 14 führen kann. Der Stoßdämpfer hat einen Kopf 15, der an dem Gelenkkopf 8 des Balkens vorzugsweise nur anliegt oder mit ihm verbunden ist.

Fig. 2 zeigt die Situation gemäß Fig. 1 oder 4 in Seitenansicht von der Fahrwasserseite her. Der Schlitten 9 ist hier von dem geschnittenen Balken 6 verdeckt; die obere und untere Führung 11 und 12 des Schlittens mit mittig dazwischen liegendem Stoßdämpfer 14 sind zu sehen. Eine Weiche 13 ermöglicht es, den Schlitten von einer horizontalen Führung 11,12 in eine vertikale Führung umzulenken, die nicht dargestellt ist. Die vertikale Führung lenkt den Schlitten und damit den angekoppelten Balken 5 in eine angepaßte Vertiefung 19, in die der Balken zur Freimachung des Fahrwassers 1 für das Passieren des Schiffes abgesenkt werden kann. Die Absenkung und spätere Anhebung (Richtungspfeile) in Wirkposition übernimmt ein Hydraulikzylinder 16 mit Stützkopf 17 für den Balken. Das gesamte System liegt unterhalb der Oberkante 3 der Schleusenkammer in der durch den Wasserstand erforderlichen Höhe, in die der Balken durch den Zylinder 16 in Hubrichtung HB gesteuert wird.

Die Fig.3 zeigt die Situation in Vorderansicht, also von der Stoßseite der Vorrichtung her. Deutlich ist der Schlitten 9 zu sehen, in Projektion zu der den Schlitten oben umgreifenden Führung 11 und der unteren Führung 12. Die Führung ist so gestaltet, daß der Balken in Längsrichtung entsprechend dem Hub HS des Stoßdämpfers 14 geführt wird und auch Stöße, die dem Balken Impulse in Richtung zur Schleusenwand sowie vertikal zur Wasseroberfläche erteilen von dem Schlitten auf die Führung übertragen werden und so den Balken in Position halten. Schrägstöße oder exzentrische Stöße auf den Balken werden durch den Gelenkbolzen in horizontale und vertikale Kräfte zerlegt. Eine wesentliche Schrägstellung des Balkens ist nicht möglich, da der Stoßdämpfer 14 mit Kopf 15 unmittelbar am Balkenkopf 8 anliegt und sofort in Wirkfunktion gerät und Reaktionskräfte erzeugt.

Fig. 4 shows the overall situation at a lock gate in plan view. The gate 4 between the lock walls 2 temporarily limits the travel of a ship in the upper water 1, which would exert an impact force S from the gate in the event of a collision if no bar 5 with an elastic ramming bar 6 would brake the ship. The bar 5 is held in position by a braking device 7 arranged in the caverns 20 (FIGS. 1-3) and, after an impact S, is pushed back into the desired position shown.

FIG. 1 shows the bar 5 with a joint head 8 held by bolts 10 (FIG. 3) and a pre-flanged slide or wheel 9. In the cavern 20 an upper guide 11 and a lower guide 12 for the slide 9 can be seen, which parallel the slide can lead to the stroke HS of the shock absorber 14. The shock absorber has a head 15, which preferably only abuts or is connected to the joint head 8 of the beam.

FIG. 2 shows the situation according to FIG. 1 or 4 in a side view from the fairway side. The carriage 9 is covered by the cut bar 6; the upper and lower guides 11 and 12 of the slide with the shock absorber 14 located in between them can be seen. A switch 13 makes it possible to deflect the slide from a horizontal guide 11, 12 into a vertical guide, which is not shown. The vertical guide directs the carriage and thus the coupled bar 5 into an adapted recess 19 into which the bar can be lowered to clear the fairway 1 for passing the ship. A hydraulic cylinder 16 with a support head 17 for the beam takes over the lowering and later raising (directional arrows) in the operative position. The entire system lies below the upper edge 3 of the lock chamber at the height required by the water level, into which the beam is controlled by the cylinder 16 in the stroke direction HB.

3 shows the situation in a front view, that is to say from the butt side of the device. The carriage 9 can be clearly seen, in projection of the guide 11 and the lower guide 12 encompassing the carriage at the top. The guide is designed in such a way that the bar is guided in the longitudinal direction in accordance with the stroke HS of the shock absorber 14, and also impacts which Beams give impulses in the direction of the lock wall and vertically to the water surface from which the slide is transmitted to the guide and thus hold the beam in position. Oblique impacts or eccentric impacts on the beams are broken down into horizontal and vertical forces by the hinge pin. A substantial inclination of the beam is not possible, since the shock absorber 14 with head 15 rests directly on the beam head 8 and immediately becomes operative and generates reaction forces.

Figure 5 shows a perspective view of a shock protection device Similar to Figure 4, but the lock gate is not shown. It is recognizable that within the quayside two left and right of the headwaters or Fairway 1 of the beams of several identically designed Braking devices 70 comprising pistons 71 and cylinders 72 are supported and so the lock gate before approaching by a not shown Protect the ship. The braking device can, as already described above, with a housing 75 for guiding the shock absorbers 71, 72 and, however, not shown for the bar 5 serve. In this case the bar is not included Rod ends equipped because the multiple system of shock absorbers for sufficient braking energy ensures. However, it is not excluded Rod ends as shown in Figure 1 are also in this case use. As an alternative for a lifting cylinder 16 with HB stroke are in this Case racks 73 arranged under the beam by pinion drives 74 be moved and hold the bar 5 in position.

Claims (8)

1. Apparatus (5 to 7, 70) for protecting locks from impacts, said apparatus including a cushioning member, which is in the form of a beam, for the absorption of impact forces of a ship, a braking apparatus (7, 70) for reducing the kinetic energy of the ship with hydraulic cylinders (14, 71, 72), means for passing the impact forces to the braking apparatus, and means (16,73,74) for keeping the beam (5) remote from the navigation channel (1) of the ship, the beam (5) being guided on each side of the waterway (1), and the hydraulic cylinders (14, 71, 72) being displaceable with a movement (HS) parallel to the guide means (11,12; 75), characterised in that the beam (5) is guided in parallel guide means (11, 12; 75), and the hydraulic cylinders (14, 71, 72) are industrial shock absorbers which have a constant braking force over the movement (HS) and are provided with an automatic resetting of the piston by means of a spring or pressure accumulator.
2. Apparatus according to claim 1, characterised in that the guide means are in their operative mode during a horizontal and/or vertical movement of the beam.
3. Apparatus according to claim 1 or 2, characterised in that the braking apparatus (7, 70) each include at least one shock absorber (14; 71,72), which is horizontally orientated relative to the beam (5) and oppositely to the direction of the impact forces (S) on each side of the waterway (1), and which shock absorber has a type of construction which is known per se.
4. Apparatus according to one of the preceding claims, characterised in that the means for keeping the beam remote from the waterway include an hydraulic cylinder (16), which is not mechanically connected to the cushioning member and which is disposed beneath said member, or spindle lifting elements or rack-and-pinion drives (73, 74).
5. Apparatus according to one of the preceding claims, characterised in that, on each side of the waterway (1), the beam (5) is provided with a pivotable head (8) which is guided in the parallel guide means (11,12; 75) by means of a slide or wheel.
6. Apparatus according to one of the preceding claims, characterised in that the guide means is provided with a switch which permits the guide means to be changed for the horizontal direction to the vertical direction.
7. Apparatus according to one of the preceding claims, characterised in that fluids of the hydraulic cylinders are conveyable into a pressure accumulator during the absorption of impact forces, and the accumulated energies are utilisable to reset the beam into its operative mode.
8. Apparatus according to one of the preceding claims, characterised in that the industrial shock absorber (14; 71,72) is filled with bio logically degradable hydraulic fluid.

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