WO2017213517A1

WO2017213517A1 - Telescopic bridge

Info

Publication number: WO2017213517A1
Application number: PCT/NO2017/050148
Authority: WO
Inventors: Trond Edvard HYSTAD
Original assignee: Tectrans As
Priority date: 2016-06-08
Filing date: 2017-06-06
Publication date: 2017-12-14

Abstract

A mobile bridge system (1) comprising a mast (5a), a telescopic bridge (3) provided with at least three bridge sections (31, 32, 33) movable relative to each other, an end portion (311) of a first bridge section (31) being pivotably connected to the mast (5a) by a horizontal bridge hinge joint (313), a lifting device (5) which is connected to the mast (5a) and arranged to pivot the bridge (3) around the horizontal bridge hinge joint (313), an actuator system (4) which forms interconnections between adjacent bridge sections (31, 32, 33), the actuator system (4) being arranged to move the bridge sections (31, 32, 33) relative to each other in a synchronous manner when the bridge (3) is being extended telescopically, the bridge unit (1a) being connected via a horizontal frame pivot joint (21) to a mobile frame (2) arranged substantially horizontally and is arranged to be pivoted between a transport position substantially parallel to the frame (2) and a position in which the mast (5a) projects up from the frame (2) and the telescopic bridge (3) projects from an end portion of the frame (2).

Description

TELESCOPIC BRIDGE

The invention relates to a mobile bridge system, in which a bridge unit comprises a mast, a telescopic bridge which is provided with at least three bridge sections displaceable relative to each other, a first end portion of a first bridge section being pivotably connected to the mast by a hori- zontal bridge hinge joint, a lifting device being connected to the mast and being arranged to pivot the bridge around the horizontal bridge hinge joint, and an actuator system comprising one or more linear actuators forming interconnections between adjacent bridge sections, the actuator system being arranged to move the bridge sections relative to each other in a synchronous manner when the bridge is being telescopically extended. For the quick establishment of a transport path, for example for pedestrians and/or vehicles, across a water surface, a hollow or the like, the use of a telescopic deck is known, which is supported, at a first end portion, on a base and is suspended from a hoisting device which at least supports the deck until it, with a second end portion, has reached an abutment which is to be connected to the base from which the deck projects. NO 326470 discloses a transport-path device for personnel and material between a floating or fixed installation offshore and a ship, more particularly a telescopic pipe with a free first end and a second end pivotably connected to the installation, suspended from a lifting device which is arranged to apply, to the telescopic pipe, a lifting force spread over several pipe sections. In the projecting end portion of the telescopic pipe, an anchoring means is arranged, for example a wire, which is connected to the structure on which the pipe is to be landed, and the pipe is then pulled towards the landing place. An actuator, which is arranged to apply an adjustable lifting force to each pipe section, by the actuator including an upstanding mast provided with a counterweight arrangement, which is arranged to keep the pipe in equilibrium is described as well.

From NO 143344, a device for transporting persons and material between ships and installations at sea is known. A flexible conveyance tunnel is arranged on the installation and projects therefrom, it being pivotable around a vertical axis and lowerable and liftable relative to the installation. The conveyance tunnel consists of a long, bendable pipe, which is suspended from a cantilever arm movably supported in the installation. The flexibility of the pipe is achieved through bending.

NO 146352 discloses details of a flexible pipe of the type that is useful with the device disclosed in NO 143344.

JP 56-28132 A, US 4590634 A and GB 2045173 A disclose other examples of telescopic pipes for the conveyance of personnel between a vessel and a shore or between two vessels.

From CN104554637A, a stationary, two-part telescopic gangway particularly arranged for access to ships from shore by a varying water level is known. The gangway is attached to a horizontal hinge joint in a frame and suspended from a vertical tower by means of wires extending from winches in the frame in several spans between the tower and the gangway, the wires running over pulleys in the tower and the outer section of the gangway. The gangway is telescoped by means of a driving motor and screw devices arranged in the inner section and connected to the second sec- tion.

EP1568627A1 discloses an extendable conveyor belt, which includes a base section and at least two telescopically movable sections, which may selectively be positioned relative to each other by means of chain operation from a motor arranged in the base section, a first chain being connected to a second section for this to be moved by means of the motor. A second chain is anchored to the second and third sections so that the third section is moved relative to the second section and synchronously with the second section.

From US8375878B1 , a mooring system with a telescopic mooring arm for transporting fluid between vessels is known. The mooring arm includes a main section connected to a turntable. The main section is suspended from a tower and is connected to a winch arranged to pivot the mooring arm around a horizontal hinge joint. An outer section may telescope in the main section as it is being moved by means of hydraulic cylinders.

The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art or at least provide a useful alternative to the prior art.

The object is achieved through the features that are specified in the description below and in the claims that follow.

The invention provides a mobile bridge system arranged for the quick establishment of a temporary bridge connection, the bridge system including a bridge unit with a telescopic bridge which is arranged to form a conveyance path for pedestrians and/or vehicles, wherein at least three bridge sections are telescopically interconnected, and wherein, in a position of application, a first end por- tion of a first section is pivotably supported in a horizontal bridge hinge joint and projects from a mobile frame, and a second end portion of an outer bridge section is arranged to land on a landing place remote from the frame. The bridge is connected to a lifting device arranged at the frame and connected to a mast, which, in an operative position, projects up from the frame. The lifting device is preferably provided with a lifting beam pivotably supported in a horizontal hinge joint arranged in the mast or frame. The lifting beam is connected to the second end portion of each bridge section remote from the first end portion of the first bridge section, by means of an elongated, continuous suspension means which is attached, by one end portion, to the second end portion of the first bridge section or to an outer portion of the lifting beam, and is attached, by its other end portion, to the second end portion of the outer bridge section or to the outer portion of the lifting beam, the suspension means being extended in several spans between the lifting beam and the second end portion of each succeeding bridge section, in a continuous length and via slideways arranged on the lifting beam and bridge section, respectively, so that a connection is formed between the outer end portion of each bridge section and the lifting beam. The slideways are typically formed as pulleys. The suspension means is typically formed from steel ropes or chains. For the lifting beam, a lifting device is arranged, adapted for rotating the lifting beam around its horizontal hinge joint. In its upper end portion, the mast, projecting up from the frame in the operative state of the bridge, is provided with guides for one or more lifting wires extending from an outer end portion of the lifting beam to a lifting winch arranged on or at the mast.

The frame is movable and is arranged substantially horizontally. The bridge unit is connected to the frame via a horizontal hinge joint and is arranged to be pivotable between a transport position, substantially parallel to the frame, and an operative position, in which the mast projects up from the frame and the telescopic bridge projects substantially horizontally from an end portion of the frame.

The lifting device preferably includes a lifting-force regulator in the form of an accumulator. In one embodiment, it may be formed as a first counterweight arrangement connected to the wire by the wire, on its way from the lifting beam to the lifting winch, having been passed over a first wire pulley, which is arranged in an upper end portion of the mast, to a second wire pulley arranged on a first weight which is arranged to be movable in the longitudinal direction of the mast, and further back to a third wire pulley in the upper end portion of the mast. The first weight is arranged to be lifted up from a stop device in the direction towards the upper portion of the mast. The mass of the weight is adapted to the size of the bridge, the maximum length of the bridge, etc., and is preferably adjustable, for example by the weight being formed as a container which can be filled with a liquid, typically water, or a particulate material, typically sand or metal particles.

Alternatively, the lifting-force regulator may be formed as a spring-loaded wire guide, which, at a certain load on the wire, is tensioned and charged. A wire guide, which is held in position by means of a hydraulic accumulator can also be used.

The bridge sections are interconnected by an actuator system comprising one or more linear actuators, which can move the bridge section relative to each other in a synchronous manner when the bridge is being extended telescopically.

In one embodiment, the linear actuator may be formed as a winch with one or more primary wires extending over guides, typically wire pulleys in the second end portion of the first bridge section, to the first end portion of the next bridge section. One or more secondary wires extend from an attachment on the first bridge section over guides in the second end portion of the second bridge section to an attachment on the first end portion of the third bridge section and correspondingly for the one or more succeeding bridge section(s). Thereby, when the primary wire is pulled onto the winch, the second bridge section and the succeeding bridge sections are moved synchronously.

Alternatively, the actuator system may be formed of hydraulic or electromechanical linear actuators, for example in the form of one or more hydraulic cylinders whose end portions are each connected to a respective one of two adjacent bridge sections, or one or more hydraulic or electric motors arranged on one bridge section engage with a corresponding transmission element, for example a pitch rack, on an adjacent bridge section. To maintain a synchronous movement of all the bridge sections when hydraulic actuators are used, it is an advantage if the actuators are connected in series or that the actuator(s) of each bridge section is/are supplied from individual, separate hydraulic circuits, for example via respective pumps.

The actuator system is preferably provided with a push-force-balancing system arranged to apply an increased push force to the bridge sections whenever required. The push-force-balancing system is formed as an accumulator, which is charged by the linear actuators.

When the linear actuator is a winch with an associated primary wire, the accumulator may be formed as a second counterweight arrangement connected to the primary wire by the primary wire being passed, on its way from the winch to the bridge, over a first primary-wire pulley to a second primary-wire pulley arranged on a second weight, which is placed in a vertically movable manner in or at the mast, and, further, back to a third primary-wire pulley, the first and the third primary-wire pulleys being arranged at a distance above the second primary-wire pulley. The second weight is arranged to be liftable from a stop device in the direction towards the first and third primary pulleys. The mass of the weight is adapted to the size of the bridge, the mass of the bridge sections, etc., and is preferably adjustable, for example by the weight being formed as a container which can be filled with a liquid, typically water, or a particulate material, typically sand or metal particles.

When the linear actuator is a hydraulic one, the accumulator can be integrated in the hydraulic system.

When the linear actuator is an electromechanical one, the accumulator may be formed as a resili- ent element, for example in the attachment of a motor or other transmission elements, for example said pitch rack.

Because of the slant of the suspension means of the lifting device when the bridge has been extended, it will retract as soon as it is lifted clear of the supporting abutment of the outer bridge section against a base and the actuator system of the bridge is released or reversed. Thereby no sep- arate means are required in order to retract the bridge into its starting position. The mobile frame may be formed as a carriage or a container arranged to be moved by means of a vehicle or a crane.

The invention is defined by the independent claim. The dependent claims define advantageous embodiments of the invention. The invention relates, more specifically, to a mobile bridge system, in which a bridge unit comprises a mast, a telescopic bridge which is provided with at least three bridge sections movable relative to each other, a first end portion of a first bridge section being pivotably connected to the mast by a horizontal bridge hinge joint, a lifting device which is connected to the mast and is arranged to pivot the bridge around the horizontal hinge joint, an actuator system which includes one or more linear actuators forming interconnections between adjacent bridge sections, the actuator system being arranged to synchronously move the bridge sections relative to each other when the bridge is being extended telescopically, characterized by the bridge unit being connected, via a horizontal frame hinge joint, to a mobile frame arranged substantially horizontally, and being arranged to be rotated between a transport position substantially parallel to the frame and an operative position in which the mast projects up from the frame, and the telescopic bridge projects substantially horizontally from an end portion of the frame.

The lifting device may be provided with a lifting beam pivotably supported in a horizontal beam hinge joint and connected to a second end portion of each bridge section remote from the first end portion of the first bridge section by means of an elongated, continuous suspension means which is attached by a first end portion to the second end portion of the first bridge section or to an outer portion of the lifting beam, and attached by a second end portion to the second end portion of an outer bridge section or to an outer end portion of the lifting beam, the suspension means having been passed in several spans between the lifting beam and the second end portion of each of the further bridge sections, in a continuous length and via slideways arranged on the lifting beam and bridge section, respectively, in order thereby to form a connection between the second end portion of each bridge section and the lifting beam.

A lifting actuator may be connected to the lifting beam, arranged to pivot the lifting beam around the horizontal beam hinge joint.

The lifting device may include guides for one or more lifting wires arranged in an upper end portion of the mast, the lifting wires extending from an outer end portion of the lifting beam to a lifting winch arranged on or at the mast.

The linear actuator may be formed as a winch with one or more primary wires extending over guides in the second end portion of the first bridge section to the first end portion of the second bridge section, and one or more secondary wires are attached to the first bridge section and extend via guides in the second end portion of the second bridge section and are attached to the first end portion of the third bridge section, and correspondingly for any succeeding, further bridge sections.

The linear actuator may be formed as hydraulic cylinders whose end portions are each connected to a respective one of two adjacent bridge sections.

The hydraulic cylinders may be connected in series, or the hydraulic cylinders of each bridge section may be connected to individual, separate hydraulic circuits.

The linear actuator may be formed as one or more hydraulic or electric motors which are arranged on one of two adjacent bridge sections and engage with a corresponding transmission element on an adjacent bridge section.

The actuator system may be provided with a push-force-balancing system arranged to apply an increased push force to the bridge sections, the push-force-balancing system being formed as a chargeable accumulator.

The primary wire may be passed between first and third primary-wire pulleys via a second primary- wire pulley arranged on a weight, which is vertically movable up from a base, the second primary- wire pulley being placed at a vertical distance below said first and third wire pulleys.

The weight may be formed as a container, which is arranged to hold a liquid or a particulate material.

The frame may be a carriage or a transport container.

In what follows, examples of preferred embodiments are described, which are visualized in the accompanying drawings, in which:

Figure 1 shows a mobile bridge system prepared for establishing a connection across a water system;

Figure 2 shows the telescopic bridge extended and landed on the opposite side of the water system;

Figure 3 shows a principle drawing of a hydraulic actuator system for telescoping the bridge;

Figure 4 shows a principle drawing of an actuator system for telescoping the bridge based on pitch-rack operation;

Figure 5 shows an alternative embodiment of the bridge system arranged on a carriage prepared for transport;

Figure 6 shows the bridge system according to figure 5 in a first phase of the establishment of a bridge connection; and Figure 7 shows the bridge system according to figure 5 in a second phase of the establishment of a bridge connection.

In figures 1 and 2, the reference numeral 1 indicates a mobile bridge system placed at an installation site 61 where a base 6 has a hollow 7, shown here as a water system, typically in the form of a river, where the installation site 61 is to be connected to a landing place 62 on the opposite side of the hollow 7 by means of the mobile bridge system 1 .

The bridge system 1 includes a frame 2, which functions as a load-carrier for the entire bridge system 1 , for example in the form of a container, which can be moved by means of a suitable vehicle or other removal means, not shown. A telescopic bridge 3 is shown here as being made up of three bridge sections 31 , 32, 33 movable relative to each other. A first bridge section 31 is connected, at a first end portion 31 1 , to the frame 2 by means of a horizontal bridge hinge joint 313.

Guides, etc., required for the bridge sections 31 , 32, 33 to be able to telescope and maintain a sufficient stability in the extended position, are not shown and will not be described in more detail here, as a person skilled in the art will have knowledge of which means can be used to provide the suitable interconnections between the bridge sections 31 , 32, 33.

In association with a lifting beam 5c and a mast 5a, there is a lifting device 51 including a lifting actuator 52 arranged on the frame 2. The mast 5a projects vertically up from the frame 2, and the lifting beam 5c is pivotably connected to the mast 5a by a horizontal beam hinge joint 51 1 . An outer portion 512 of the lifting beam 5c located from remotely the horizontal beam hinge joint 51 1 is connected to a lifting wire 522 which extends via wire pulleys 524, 525 in an upper end portion of the mast 5a to a lifting winch 521 . The lifting actuator 52 includes a lifting-force regulator 53 in the form of an accumulator, shown here as a counterweight arrangement formed as a first weight 531 arranged internally in the mast 5a and suspended from the lifting wire 522 which has been passed over first and third wire pulleys 524, 525 in the upper end portion of the mast 5a. The lifting wire 522 has been passed over a second wire pulley 532 arranged on the weight 531 . An end stop 533 is arranged below the weight 531 and functions as a limiter of the extent of adjustment of the lifting- force regulator 53.

The lifting beam 5c is connected to the second end portion 312, 322, 332 of each bridge section 31 , 32, 33 remote from the bridge hinge joint 313 by means of an elongated, continuous suspension means 54, for example a wire which is attached by its first end portion 541 to the lifting beam 5c and is attached by its second end portion 542 to the second end portion 312 of the first bridge section 31 . The intermediate portion of the suspension means 54 is passed in several spans between the lifting beam 5c and the second end portions 312, 322 of the first and second bridge sec- tions 31 , 32, in a continuous length and connected to the lifting beam 5c and the second and third bridge sections 32, 33, respectively, by means of slideways 324, 334, for example wire pulleys. By the sliding connections of the suspension means 54 to the lifting beam 5c and the outer end portions 322, 332 of the bridge sections 32, 33 and also the fixed connection to the outer end portion 312 of the first bridge section 31 , an even distribution of the lifting force on all the bridge sections 31 , 32, 33 is maintained.

The telescopic bridge 3 is provided with an actuator system 4 arranged to move the bridge from a retracted position, as is shown in figure 1 , to an extended position, as is shown in figure 2, by synchronous movement of the second and third bridge sections 32, 33. A linear actuator 41 connects the first and second bridge sections 31 , 32, the linear actuator 41 being shown here as a winch with a primary wire 41 1 extending from the winch 41 via guides 315, shown here as wire pulleys, on the second end portion 312 of the first bridge section 31 to the first end portion 321 of the second bridge section 32. A secondary wire 42 extends from an attachment 316 on the first bridge section 31 via guides 325, shown here as wire pulleys, on the second end portion 322 of the second bridge section 32 to the first end portion 331 of the third bridge section 33. When the second bridge section 32 is moved outwards by means of the linear actuator 41 , the third bridge section 33 is thereby moved outwards relative to the second bridge section 32.

When the bridge 3 is to be retracted again, this will happen as soon as the bridge is lifted clear of the landing place 62 and the linear actuator 41 released or reversed, by the very fact of the suspension means 54 of the lifting device 5 being slanted and applying a force component to the tele- scoping bridge sections 32, 33 that acts in the longitudinal direction of the bridge sections 32, 33 towards their first end portions 321 , 331 .

In figure 3, a principle drawing of a hydraulic actuator system 4 with hydraulic linear actuators 41 for the synchronous telescoping of the second and third bridge sections 32, 33 is shown. A first double-acting hydraulic cylinder 41 b is connected to the first and second bridge sections 31 , 32. A second double-acting hydraulic cylinder 41 c is connected to the second and third bridge sections 32, 33. A hydraulic aggregate 41 a provides the piston side of the first hydraulic cylinder 41 b with pressurized fluid. The piston-rod side of the first hydraulic cylinder 41 c is connected in a fluid- communicating matter to the piston side of the second hydraulic cylinder 41 c. The internal cross- sectional area of the piston-rod side of the first hydraulic cylinder 41 b is as large as the internal cross-sectional area of the piston side of the second hydraulic cylinder 41 c. The extension of the piston in the first hydraulic cylinder 41 b will thereby result in the piston of the second hydraulic cylinder 41 c being displaced correspondingly. An accumulator 41 d is connected between the hydraulic aggregate 41 a and the first hydraulic cylinder 41 b.

In figure 4, a principle drawing of a mechanical actuator system 4 with electro- or hydraulic- mechanical linear actuators 41 for the synchronous telescoping of the second and third bridge sections 32, 33 is shown. On each of the second and third bridge sections 32, 33, a first transmission element in the form of a pitch rack 41 a is resiliently attached, the pitch rack 41 e being displaceable in its longitudinal direction in a resilient pitch-rack mount 41 h. A second transmission element in the form of a toothed wheel 41 f arranged on a driveshaft of a motor 41 g, which is attached to the respective adjacent first or second bridge section 31 , 32 engages with the pitch rack 41 e. The motors 41 g may be electrically or hydraulically operated. With hydraulic operation, the motors 41 g are connected in series or connected each to a respective hydraulic circuit for synchronous displacement of the bridge sections 32, 33 to be achieved.

In figures 5, 6 and 7, an exemplary embodiment of the bridge system 1 is shown, in which a bridge unit 1 a is arranged on a movable undercarriage 2a, typically in the form of a carriage which can be connected to a vehicle, typically a lorry, not shown, or a movable container, typically a standard 40- feet so-called "open top container".

The bridge unit 1 a, comprising the mast 5a, the lifting beam 5c and the telescopic bridge 3 with the previously mentioned actuators, systems and suspension means 4, 43, 52, 54 for lifting and extending the bridge 3 (not shown in figures 5, 6 and 7, for the sake of exposition), is pivotably connected to the undercarriage 2a around a horizontal frame hinge joint 21 , the frame hinge joint 21 connecting an end portion of the undercarriage 2a and a first end portion of the mast 5a. A tilting actuator 22, shown here as a hydraulic cylinder, forms a connection between a forward portion of the undercarriage 2a and a second end portion of the mast 5a and is arranged to pivot the bridge unit 1 a between a horizontal transport position, as shown in figure 5, and a raised position, as shown in figures 6 and 7. An end portion of the lifting beam 5c is pivotably attached to the mast 5a as described above. The first bridge section 31 is attached to the first end portion of the mast 5a via the bridge hinge joint 313 and is pivotable between a transport position parallel to the mast 5a and an approximately horizontal, active position as shown in figure 7. The pivoting of the bridge 3 is typically carried out with the aid of the aforementioned lifting device 5.

With advantage, the mast 5a and the lifting beam 5c are telescopic, suggested in figure 7 by a tele- scoping mast section 5b and a telescoping lifting-beam section 5d, respectively.

The undercarriage 2a may be provided with means (not shown) for adjusting the height of the undercarriage above the base 6, for example in the form of lifting means in association with a wheel system 2a, so that the first bridge section 31 is resting supportingly against the base 6 on the installation site 61 before the second and third bridge sections 32, 33 are extended. It should be noted that all the above-mentioned embodiments illustrate the invention, but do not limit it, and persons skilled in the art may construct many alternative embodiments without departing from the scope of the attached claims. In the claims, reference numbers in brackets are not to be regarded as restrictive.

The use of the verb "to comprise" and its different forms does not exclude the presence of ele- ments or steps that are not mentioned in the claims. The indefinite article "a" or "an" before an el- ement does not exclude the presence of several such elements.

The fact that some features are indicated in mutually different dependent claims does not indicate that a combination of these features cannot be used with advantage.

Claims

C l a i m s

A mobile bridge system (1), in which a bridge unit (1 a) includes a mast (5a), a telescopic bridge (3) which is provided with at least three bridge sections (31 , 32, 33) movable relative to each other, a first end portion (31 1 ) of a first bridge section (31) being pivot- ably connected to the mast (5a) by a horizontal bridge hinge joint (313), a lifting device (5) which is connected to the mast (5a) and is arranged to pivot the bridge (3) around the horizontal bridge hinge joint (313), an actuator system (4) which comprises one or more linear actuators (41 , 41 1 , 42) forming interconnections between adjacent bridge sections (31 , 32, 33), the actuator system (4) being arranged to move the bridge sections (31 , 32, 33) relative to each other in a synchronous manner when the bridge (3) is being extended telescopically, c h a r a c t e r i z e d i n that the bridge unit (1 a) is connected via a horizontal frame pivot joint (21) to a mobile frame (2) arranged substantially horizontally and is arranged to be pivoted between a transport position substantially parallel to the frame (2) and an operative position in which the mast (5a) projects up from the frame (2) and the telescopic bridge (3) projects substantially horizontally from an end portion of the frame (2).

The mobile bridge system (1 ) according to claim 1 , wherein the lifting device (5) is connected to a lifting beam (5c) which is pivotably supported in a horizontal beam hinge joint (51 1) and is connected to a second end portion (312, 322, 332) on each bridge section (31 , 32, 33) remote from the first end portion (31 1) of the first bridge section (31 ) by means of an elongated, continuous suspension means (54) which is attached by a first end portion (541) to the second end portion (312) of the first bridge section (31) or to an outer end portion (512) of the lifting beam (5c) and is attached by a second end portion (542) to the second end portion (332) of an outer bridge section (33) or to an outer end portion (512) of the lifting beam (5c), the suspension means (51) having been passed in several spans between the lifting beam (5c) and the second end portion (312, 322, 322, 332) of each of the further bridge sections (31 , 32, possibly 32, 33) in a continuous length and via slideways (513; 324, 334) arranged on the lifting beam (5c) and bridge section (32, 33), respectively, in order thereby to form a connection between the second end portion (312, 322, 332) of each bridge section (31 , 32, 33) and the lifting beam (5c).

The mobile bridge system (1 ) according to claim 2, wherein a lifting actuator (52) is connected to the lifting beam (5c), arranged to pivot the lifting beam (5c) around the horizontal beam hinge joint (51 1).

The mobile bridge system (1) according to claim 1 , wherein the lifting device (5) includes guides (524, 525) for one or more lifting wires (522) arranged in an upper end portion of the mast (5a), the lifting wires (522) extending from an outer end portion (512) of the lifting beam (5c) to a lifting winch (521) arranged on or at the mast (5a).

5. The mobile bridge system (1 ) according to claim 1 , wherein the linear actuator is formed as a winch (41) with one or more primary wires (41 1) extending over guides (315) in the second end portion (312) of the first bridge section (31) to the first end portion (321 ) of the second bridge section (32) and one or more secondary wires (42) are attached to the first bridge section (31) and extend via guides (325) in the second end portion (322) of the second bridge section (32) and are attached to the first end portion (332) of the third bridge section (33), and correspondingly for any succeeding, further bridge sections.

6. The mobile bridge system (1 ) according to claim 1 , wherein the linear actuator (41) is formed as hydraulic cylinders (41 b, 41 c) which are connected by their end portions to respective ones of two adjacent bridge sections (31 , 32; 32, 33).

7. The mobile bridge system (1 ) according claim 6, wherein the hydraulic cylinders (41 b, 41 c) are connected in series or the hydraulic cylinder (41 b, 41 c) of each bridge section (32, 33) is connected to individual, separate hydraulic circuits.

8. The mobile bridge system (1 ) according to claim 1 , wherein the linear actuator (41) is formed as one or more hydraulic or electric motors (41 g) which are arranged on one of two adjacent bridge sections (32, 32) and engage with a corresponding transmission element (41 e) on an adjacent bridge section (32, 33).

9. The mobile bridge system (1 ) according to claim 1 , wherein the actuator system (4) is provided with a push-force-balancing system (43) arranged to apply a desired push force to the bridge sections (31 , 32, 33), the push-force-balancing system (43) being formed as a chargeable accumulator (431).

10. A mobile bridge system (1) according to claim 5, wherein the primary wire (41 1) is passed between a first and third primary-wire pulley (432, 434) via a second primary- wire pulley (433) arranged on a weight (431) which is vertically movable up from a base (2), the second primary-wire pulley (433) being placed at a vertical distance below said first and third primary-wire pulleys (432, 434).

1 1 . Mobile bridge system (1) according to claim 10, wherein the weight (431) is formed as a container, which is arranged to hold a liquid or a particulate material.

12. The mobile bridge system (1 ) according to claim 1 , wherein the frame (2) is a carriage or a transport container.