EP2787148A1 - Demolition device, in particular hydraulic demolition shears - Google Patents

Abstract

The invention relates to a demolition device (26), in particular a hydraulically operated demolition shears (26) for free-hanging recording on at least one supporting cable (18) of a construction machine (10). The free-hanging demolition shear (26) has radially extending support arms (56, 58, 60, 62) on which at least one stabilizing weight (72, 76) is suspended.

Description

Technical area

The present invention relates to a demolition device, in particular a hydraulically actuated demolition shears, which is added to a hydraulic unit having a construction machine, such as a rope excavator suspended. The demolition device is connected via at least one hydraulic hose with the Hydraulikaggegrat the construction machine and pressurized by this.

State of the art

JP 02132277A has a demolition device to the object, which has a top plate. At this a hydraulically operated demolition shears is suspended. The top plate comprises arms extending in the radial direction.

US 5,044,568 refers to a manually operated demolition shear. This is received on a support cable and is operated by an operator and acted upon by hydraulic fluid.

FR 2 822 482 A1 has a hydraulic shears to the object. These scissors can be provided with different geometries having pincers. One and the same scissor head provided with hydraulic cylinders can be used and equipped with differently configured pincers, depending on the application, so that the versatility of use of the scissors according to FR 2 822 482 A1 expand.

JP 202097799 A discloses a demolition device with a plate, on the one hand a hydraulically operated scissors is suspended and on the other hand, a balance weight. The a balance weight suspended below the common plate can be suspended in three different positions relative to the radial direction with respect to the central suspension of the common plate.

In industrial dismantling, such as in the dismantling of chimneys, silos, industrial halls or structures of inland navigation such. Locks, lock chambers and boundary walls and the like, heavy equipment is used such as crawler excavators. For example, the crawler loaders can be provided with a relatively high weight falling weight which very rapidly collapses the walls of factory buildings, the roofs of factories or even silos due to the mechanical momentum at the impact weight drop. With a rope excavator, which has a several tens of meters long boom, both structures that have a height of up to 78 meters, dismantled, also exists due to the carrying cable guides on an excavator the possibility, even in trenches, lock chambers. work below ground level.

On construction machines, such as cable excavators, which usually have a hydraulic power unit, demolition equipment, such as hydraulically operated demolition shears can be used. The connection of the hydraulically actuated demolition shears to the hydraulic unit of a construction machine such as a cable excavator is usually via a pair of hydraulic hoses, while the weight of the hydraulically operated demolition shears, which can be up to 20 t, is taken up by at least one support cable of a cable shovel.

With demolition devices, such as hydraulically actuated demolition shears, it is possible to remove or dismantle structures provided with steel reinforcements, such as walls or solid walls, which is not readily possible with a drop weight due to the steel reinforcements of these structures. Hydraulically operated demolition shears, such as hydraulic shears usually comprise two articulated gripping tongs, which iron shears and reinforcing steels and the like, which are present in otherwise made of concrete structures, simply cut and therefore allow disassembly of such structures in the first place.

It has now been found that cantilever demolition shears on cable shears, which are attached to a support cable and pressurized via a pair of hydraulic hoses are due to their high performance structures are able to dismantle, which have a wall thickness of up to 2.40 m and which include a certain number of reinforcing bars or reinforcing bars. The use of a self-supporting demolition shear becomes all the more problematic, the thicker the structures to be dismantled are in terms of their wall thickness and the more reinforcing bars or reinforcing bars are installed in them. From a certain building size or building wall thickness, the performance of the demolition device in the form of a hydraulically actuated demolition shears is not large enough to ensure that the two apart gripping tongs of the scissors dig into the material of the structure to be demolished, it comes to a tilting or pushing up the tons of demolition shears from the structure to be dismantled. This is due to the fact that the demolition device is accommodated in the form of a hydraulic shear on the at least one supporting cable of a cable excavator suspended and is acted upon by at least one pair of hydraulic hoses with hydraulic fluid. The at least one support cable can not transfer any supporting force to the demolition device, which is only able to transfer its own weight as a contact force to the structure to be dismantled.

By pushing up the hydraulically actuated demolition shears, the force exerted by the demolition device, generated by hydraulic power can not be completely transformed into destructive performance, which is essential in the dismantling of the structure, so that on the one hand more frequent startups are to take and on the other hand, the disassembly process unnecessarily lengthened.

Presentation of the invention

The present invention has for its object to provide a demolition device, in particular a hydraulically operated demolition shear, which is acted upon by an increased supporting force and in which a Wegbewegen is significantly reduced from the structure to be dismantled.

According to the invention a demolition device, in particular a hydraulically operated demolition shears for free-hanging recording on at least one supporting cable of a construction machine, such as a cable excavator proposed, wherein the free-hanging demolition device has radially extending support arms on which at least one stabilizing weight is suspended. The at least one stabilizing weight is in the head region of the demolition device, in particular a attached hydraulically operated demolition shears, so that as possible outgoing from the scissor head of the hydraulically operated demolition shears supporting force can be introduced into the demolition shears. Due to the stabilization weights, the center of gravity of the Abrucheinrichtung is moved further down.

In an advantageous embodiment of the idea underlying the invention, in the region of a top plate of the demolition device on the scissor head are a number, for example 4 support arms, which extend substantially in the radial direction. These extending in the radial direction support arms each have eyelets on which free-hanging stabilizing weights, the weight of which can be up to 5 t, are suspended. The 4 support arms may be designed to be pivotable in the radial direction in the region of a head plate on the scissor head; They may, for example, have an angle of 90 ° with each other. Also, a number other than 4 support arms or a different angle division than 90 ° with respect to the support arms with each other is possible; Thus, for example, in the region of the head plate 3 support arms can be arranged, which are arranged with each other with respect to the top plate in a 120 ° pitch. Preferably, the top plate is mounted in the region of the scissor head of the hydraulically operated demolition shears and comprises a Tragarmaufnahme. Within the support arm receiver, the ends of the support arms are bolted. In the edge region of the top plate, for example in the region of half of the radial extent of the support arms, are located on both sides of the support arms adjustable stops on the top plate. These two-sided stops can crossbeams, which are accommodated studs, which support the support arms mounted in the Tragarmaufnahme state on the top of the top plate. The two-sided stops each comprise on both sides of the support arms adjacent studs, which support the support arms centrally and counteract an impermissibly strong bending in the horizontal plane. Preferably, the support arms are designed as a double-T-beam, T-beam or box frame profile, which are bolted edgewise in the Tragarmaufnahme and which are supported in the region of half their length by the cross member of a respective support arm associated with two-sided stop.

For hydraulic loading of the demolition device in the form of a hydraulically actuated demolition shears, the scissors head comprises a connection head with hydraulic connections, in addition to the hydraulic hoses, or the pair of hydraulic hoses, and the at least one support cable is mounted, which the weight of the demolition device and the weight of in addition to receiving stabilizer weights attached to the support arms. The at least one pair of Hydraulic hoses is guided parallel to the at least one support cable, deflected at the tip of the boom, in the engine room of the construction machine, in particular a cable excavator, out and there is acted upon by a hydraulic unit. When the support cable is operated in the vertical direction, a synchronized shortening or length of the at least one pair of hydraulic hoses takes place in order to avoid damage due to unacceptably high tensile stresses in the hydraulic hoses.

In an advantageous embodiment of the invention underlying idea, the stabilization weights are mounted on the eyelets at the outer ends of the support arms. It is possible to connect the stabilization weights via tethers with the eyelets on the support arms. The tethers have a length that exceeds the length of the demolition device, the hydraulically actuated demolition shears, so that the stabilization weights are below the lower ends of the hydraulically actuated tongs that constitute the scissor jaw. As a result, a functional impairment of the demolition device is avoided, since the at least one stabilizing weight is located at a sufficient distance from the working range of the gripping tongs of the hydraulically actuated demolition shears.

The top plate, at the support arm receiving the pivotable in the radial direction support arms, is preferably provided with an opening pattern, which are formed by pairs of openings, for example formed as holes. In accordance with the opening pattern provided on the top plate, the two-sided stops corresponding to the opening pattern on the top plate can be converted into these openings, so that the support arms can also be pivoted in both directions. This may be necessary, for example, if a part of a structure to be demolished is in the way, so that a different support arm configuration or angular position of the support arms with respect to the top plate must be selected. By inventively proposed solution can be achieved in an advantageous manner that a tensile and compressive load in the scissor head of the hydraulically operated demolition shear without functional impairment of the same and a dynamic application of force in all directions can be displayed. The entire hydraulic power can be converted by the proposed solution according to the invention in destructive performance for the dismantling of structures, as is prevented by the stabilizing weights that the hydraulically operated demolition shears when closing the Gripping cheeks whose movement moves towards each other in a vertical upward direction of the building to be dismantled.

Brief description of the drawings

With reference to the drawings, the invention will be described in more detail below.

Figur 1

die schematische Darstellung einer Baumaschine in Gestalt eines Seilbaggers mit einer an mindestens einem Tragseil befestigten Abbrucheinrichtung mit einer hydraulisch betätigten Abbruchschere sowie den Verlauf von Hydraulikschläuchen zur Abbrucheinrichtung zwischen dieser und einem Hydraulikaggregat der Baumaschine,

Figur 2

eine Seitenansicht der geöffneten Abbrucheinrichtung in Gestalt einer zwei hydraulisch betätigte Greifwangen aufweisenden Abbruchschere,

Figur 3

die Draufsicht auf eine Kopfplatte im Bereich des Scherenkopfes der Abbrucheinrichtung mit in 90° Teilung angeordneten Tragarmen zur Aufnahme der Stabilisierungsgewichte und

Figur 4

eine perspektivische Draufsicht auf die an einer Kopfplatte im Bereich des Scherenkopfs angeordneten Tragarme mit Anschlusskopf für Hydraulikanschlüsse.

It shows:

FIG. 1

the schematic representation of a construction machine in the form of a cable excavator with a demolition device attached to at least one support cable with a hydraulically actuated demolition shears and the course of hydraulic hoses for demolition device between this and a hydraulic unit of the construction machine,

FIG. 2

a side view of the open demolition device in the form of a two hydraulically operated gripping jaws having demolition shears,

FIG. 3

the top view of a head plate in the region of the scissor head of the demolition device with arranged at 90 ° pitch support arms for receiving the stabilization weights and

FIG. 4

a top perspective view of the arranged on a head plate in the region of the scissor head support arms with connection head for hydraulic connections.

variants

FIG. 1 shows a construction machine in the form of a cable excavator with hydraulic unit and a demolition device which is accommodated on a support cable of the cable excavator and is pressurized by hydraulic hoses.

A construction machine 10 - here configured as a cable excavator - comprises a boom 12, counterweights 20 and at least one hydraulic unit 14 received within an engine room of the construction machine 10. Hydraulic hoses 16, in particular a pair of hydraulic hoses 16 with a pressurized hydraulic fluid, are connected via the hydraulic power unit 14 applied. The construction machine 10 in shape a cable excavator also has at least one support cable 18, which extends from a deflection 22 to a demolition device 26, a hydraulically operated demolition shears. The demolition device 26 is pressurized via the at least one pair of hydraulic hoses 16 via the hydraulic unit 14 provided in the construction machine 10 with pressurized hydraulic fluid.

In addition to a deflection 22 for the at least one supporting cable of the construction machine 10, located at the top of the boom 12 of the construction machine 10 in the form of a cable excavator another deflection 24, which is provided for the at least one pair of hydraulic hoses 16. With the construction machine 10 as shown in FIG FIG. 1 Industrial structures such as chimneys, silos, factories can be dismantled, which have a total height of approximately up to 78 meters. In addition, with the construction machine 10, in particular a cable excavator, given the opportunity to reach even below the normal level lying construction sites, such as lock chambers, shafts or reinforcement walls.

From the schematic representation according to FIG. 1 shows that the at least one support cable 18 of the construction machine 10, as well as hydraulically acted upon via a pair of hydraulic hoses 16, the demolition device 26, in the form of a hydraulically operated demolition shears. The demolition device 26 includes a scissor head 28, in the region of which a connection head 34 is located. The connecting head 34 is used to connect the at least one pair of hydraulic hoses 16 to the hydraulically operated demolition shears 26. This comprises a joint 36, with which opposing tongs 38, 40 are connected to one another in an articulated manner. Each of the two pliers 38, 40 is acted upon by a separate hydraulic cylinder 30 or 32, which in turn is in communication with the connection head 34, to which the one pair of hydraulic hoses 16 is connected.

In a movement of the demolition device 26 designed as a hydraulically operated demolition shears in the vertical direction up or down moves the at least one pair of hydraulic hoses 16 corresponding to the double arrows in each case synchronously with the movement of the at least one support cable 18 so that relative movements between them, in particular in the connection region of at least one Pair of hydraulic hoses 16 are excluded at the connection head 34 of the hydraulically operated demolition shears 26.

FIG. 2 shows the demolition device 26 as hydraulically confirmed demolition shears in an embodiment proposed according to the invention.

FIG. 2 shows that the demolition device 26 in the form of a hydraulically actuated demolition shears two opposing cheeks 38 and 40 has. In the illustration according to FIG. 2 are the two cheeks 38, 40, which are hinged together at the joint 36, in an open position. Each of the cheeks 38, 40 is acted upon by a separate hydraulic cylinder 30 and 32, respectively. The hydraulic cylinders 30, 32 are based on the one hand in the region of the scissors head 38 on abutments 42 and 44 from hinged; On the other hand, the extendable from the hydraulic cylinders 30, 32 piston rods at a first pivot point 46 to the first cheek 38 and at a second pivot point 48 to the second cheek 40 are pivotally connected together. The movement of the two hinged together cheeks 38, 40 takes place synchronously with each other. The two hydraulic cylinders 30, 32 are connected via the provided on the connection head 34 hydraulic connections 70 with the in FIG. 1 shown at least one pair of hydraulic hoses 16 via the hydraulic unit 14 of the construction machine 10, in particular a cable shovel, acted upon by pressurized hydraulic fluid.

From the side view according to FIG. 2 Furthermore, it can be seen that the demolition device, in particular designed as a hydraulically operated demolition shears 26, has a top plate 50 in the area of the shears head 28. The head plate 50 in turn is connected to a Tragarmaufnahme 52, to which a number of support arms 56, 58, 60 and 62 may be added. The support arms, of which in the illustration according to FIG. 2 the side view of the first support arm 56, and the opposite this support arm 60 are shown, the second support arm 58 is shown in plan view, are preferably formed as T-profiles or as double-T profiles. At the radially outwardly projecting ends of all support arms 56, 58, 60, 62 - wherein the third support arm 60 in the side view according to FIG. 2 for illustrative reasons is not shown - there is an eyelet 64 or other suspension element.

From the side view according to FIG. 2 Furthermore, it is apparent that the individual support arms 56, 58, 60, 62, which are bolted at their inner ends in the Tragarmaufnahme 52, approximately centrally with two-sided stops 54 are provided. The two-sided stops 54 each include a cross member 55, are recorded on the studs. These are located on both sides of the support arms 56, 58, 60 and 62 and fix them in the horizontal plane. The resulting forces are introduced into the top plate 50. The individual, radially outwardly extending support arms 56, 58, 60 and 62 are supported by the cross member 55 of the two-sided stops 54 on the top plate 50.

The individual, radially outwardly extending support arms 56, 58, 60, 62 fastened in the support arm receptacle 52 are provided with stabilizing weights 72 and 76 at their outer ends. As a result, the entire demolition device 26, in particular designed as a hydraulically actuated demolition shears, acted upon by an increased supporting force, which at least achieves the deadweight of the demolition device 26 in the form of a hydraulically operated demolition shears and may exceed. The center of gravity of the Abrucheinrichtung 26 is moved down. According to the dimensioning of the support arms 56, 58, 60 and 62 can - as in FIG. 2 schematically indicated - via a first tether 74, a first stabilizing weight 72 and a second tether 78 another, second stabilizing weight 76 are mounted. As a result, the force with which the hydraulically actuated demolition shears 26 acts on a structure to be dismantled, provided with reinforcing steels or reinforcing iron increases by a multiple. This support force can not apply the at least one support cable 18 of the construction machine 10 in the form of a cable shovel, and the weight of the demolition device 26 in the form of a hydraulically operated demolition shears is often too low to avoid tipping or pushing up from the structure to be demolished. By inventively proposed solution is by generating an increased supporting force by means of the stabilizing weights 72, 76, a high pressures, ie a substantially vertically upward Weggendes weg the demolition scissors 26 to be destroyed structure avoided because of the stabilizing weights 72, 76, the contact force At just that building, which is to be dismantled, is significantly increased. Consequently, the entire hydraulic power can also be converted into destructive power, since the above-outlined deflection movement of the demolition device 26, a push-up away from the structure to be dismantled, is ideally excluded or at least significantly reduced.

By inventively proposed solution is achieved that at at the radially outwardly standing support arms 56, 58, 60, 62 attached at least one stabilizing weight 72, 76 and a carrying capacity of the support arms 56, 58, 60, 62 up to 20 t total weight of stabilization weights can be hung.

From the illustration according to FIG. 2 shows that the first stabilizing weight 72 is mounted on a tether 54 on the eyelet 64 of the third support arm 60. On the other hand, there is also the possibility - as in FIG. 2 indicated - execute a second tether 78, for example, in a length, so that the second stabilizing weight 76 is disposed below the end of the open first cheek 38 of the designed as a hydraulically operated demolition shear demolition device 26. The more deeply the stabilizing weights 72, 76 are placed with respect to the ends of the hydraulically operated first cheek 38 and second cheek 40, the farther out of the working range of the two hinged cheeks 38, 40 are those located on the Supporting arms 56, 58, 60, 62 respectively suspended stabilization weights 72, 76. The said tethers 70, 78 are formed in a length, so that the stabilization weights 72, 76 suspended thereon are located below the scissors jaw of the demolition shear 26. In itself, their functionality is not affected.

The representation according to FIG. 3 is a plan view of the arranged on a top plate support arms to take.

As FIG. 3 shows, the radially inner ends of the four support arms 56, 58, 60, 62 used here on the Tragarmaufnahme 52, which is located in the center of the top plate 50, bolted. Instead of in the plan view according to FIG. 3 illustrated four support arms 56, 58, 60, 62, which are arranged here in 90 ° division, there is also the possibility, in a modification of the invention, in 120 ° division on the top plate 50, only three support arms 56, 58, 60 to arrange. Finally, it is also possible, on the top plate 50 two opposing, ie to install in 180 ° division, two support arms on which the stabilizing weights 72, 76 can be mounted.

From the plan view further shows that the individual support arms 56, 58, 60, 62, which are each provided with eye-shaped suspension elements 64 on their undersides, are supported by the double-sided stops 54 against excessive bending loads. The two-sided stop 54 are designed such that the support arms 56, 58, 60, 62 configured as double T-beams are laterally fixed by stud bolts. The bending load of the support arms 56, 58, 60 and 62 is absorbed by the top plate 50, the studs fix them laterally. The top view according FIG. 3 also shows that the top plate 50 has a number of openings 68. The openings 68 may, for example, be designed as bores and form an opening or bore pattern 66 Openings 68 and bores 68, respectively, formed in the circularly configurable top plate 50 allow the two-sided stops 54 to be secured in different angular positions with respect to each other so that a high variability in the mounting of the support arms 56, 58, 60, 62 is possible. In the plan view according to FIG. 3 are the four support arms 56, 58, 60,62 positioned at 90 ° to each other. Seen in the circumferential direction 80 (see illustration according to FIG FIG. 4 ), it is also possible to arrange the support arms 56, 58, 60, 62 at different pitches on the top plate 50, corresponding to the opening or bore pattern 66. By the opening or bore pattern 66, which is provided in the top plate 50, can be achieved that the support arms 56, 58, 60, 62 respectively associated two-sided stops 54 are implemented in different positions on the top plate 50. This makes it possible to adapt the position of the support arms 56, 58, 60, 62 to the structural geometry, for example when it is necessary to work on a wall.

FIG. 4 shows a top perspective view of the top plate with it received support arm and support arms with suspension elements.

The perspective view according to FIG. 4 shows that the support arms 56, 58, 60 and 62 bolted to the Tragarmaufnahme 52 at its inner ends are supported by the cross members 55 of the two-sided stops 54 at the edge region of the top plate 50. The support arms 56, 58, 60, 62 can be configured as either a double T or a T-beam. The studs of the two-sided stops 54 are designed so that they come laterally to the lower webs of the here in this embodiment designed as a double-T profiles support arms 56, 58, 60, 62 to the plant. By the two-sided stops 54, the support arms 56, 58, 60, 62 are fixed. Occurring bending forces are introduced via the two-sided stops 54 in the substantially circular head plate 50. The opening or bore pattern 66, which is provided in the top plate 50, on the one hand so designed that a large variance of different installation positions or angular positions of the support arms 56, 58, 60, 62 can be realized with respect to each other, without on the other hand, in turn, a mechanical weakening of the support plate 50 is brought about, so that it is able to withstand the mechanical loads permanently.

From the perspective top view according to the representation in FIG. 4 also shows that in the upper part of the scissors head 28 of the connection head 34 is located. In the region of the connection head 34, on the one hand, the at least one carrying cable 18 can be fastened; on the other hand, in the region of the connection head 34, the hydraulic connections 70 are located, at which the at least one pair of hydraulic hoses 16 (see illustration according to FIG FIG. 1 ) can be connected pressure-tight, over which the in FIG. 2 shown first and second hydraulic cylinders 30 and 32 of the break-off device 26 designed as hydraulically operated demolition shears are actuated.

If at the radially outwardly projecting end points of the support arms 56, 58, 60, 62, for example, stabilizing weights 72, 76 are attached to the suspension eyes 64, then the force with which the demolition device 26 acts on the structure to be dismantled can be increased considerably This can not be applied by the at least one support cable 18, which is only able to absorb tensile forces. According to the structure to be dismantled, there is a high variance of stabilizing weights 72, 76 to be suspended at the ends of the radially projecting support arms 56, 58, 60. 62. The solution proposed by the invention results in a high pressure or a differently extending, for example, a tilting movement of the demolition device 26 avoided by the structure to be dismantled, so that the entire power generated by the at least one hydraulic unit 14 of the construction machine 10 can be converted into destructive power.

LIST OF REFERENCE NUMBERS

10

Dragline

12

boom

14

hydraulic power unit

16

hydraulic hoses

18

supporting cable

20

counterweight

22

Redirecting suspension rope

24

Redirection of hydraulic hoses

26

Demolition shear, demolition device

28

Abbruchschere head

30

1. Hydraulic cylinder

32

2. Hydraulic cylinder

34

connection head

36

joint

38

1. cheek

40

2nd cheek

42

Abutment 1. Hydraulic cylinder

44

Abutment 2. hydraulic cylinder

46

1. articulation point

48

2nd articulation point

50

headstock

52

carrier arm

54

Double-sided stop, studs

55

crossbeam

56

1st support arm

58

2nd support arm

60

3rd support arm

62

4. Support arm

64

eyelet

66

hole pattern

68

drilling

70

hydraulic connections

72

1. stabilization weight

74

1. Tether

76

2. Stabilization weight

78

2nd guy

80

circumferentially

Claims (9)

Demolition device (26) in particular a hydraulically operated demolition shear (26) having a head plate (50) for free-hanging recording on at least one support cable (18) of a construction machine (10), characterized in that the hydraulically operated demolition shears (26) freely suspended and the top plate (50) has radially extending support arms (56, 58, 60, 62) on which at least one stabilizing weight (72, 76) is suspended. Demolition device (26) according to claim 1, characterized in that the radially extending support arms (56, 58, 60, 62) in the circumferential direction (80) are adjustable. Demolition device (26) according to one of the preceding claims, characterized in that the head plate (50) is received on a demolition scissor head (28) which is designed for dynamic compressive and tensile loading. Demolition device (26) according to the preceding claim, characterized in that on the top plate (50) a Tragarmaufnahme (52) is provided, the ends of the support arms (56, 58, 60, 62) receives. Demolition device (26) according to one of the preceding claims, characterized in that the demolition shears head (28) has a connection head (34) with hydraulic connections (70) to which hydraulic hoses (16) are connected, which are connected by a hydraulic unit (14) of the construction machine (10 ) are acted upon. Demolition device (26) according to one of the preceding claims, characterized in that the head plate (50) the support arms (56, 58, 60, 62) respectively associated two-sided stops (54). Demolition device (26) according to one of the preceding claims, characterized in that the head plate (50) comprises an opening pattern (66) of openings (68), in particular bores, in which the support arms (56, 58, 60, 62) for lateral guide respectively associated two-sided stops (54) can be reversed. Demolition device (26) according to one of the preceding claims, characterized in that the two-sided stops (54) each comprise cross members (55) which support the respective support arm (56, 58, 60, 62) on the top plate (50). Demolition device (26) according to one of the preceding claims, characterized in that the support arms (56, 58, 60, 62) each receive stabilization weights (72, 76) of up to 5 t.

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