EP2678262A1

EP2678262A1 - Mobile crane

Info

Publication number: EP2678262A1
Application number: EP12748951.6A
Authority: EP
Inventors: Magnus Bergkvist; Jonas STENBERG; Gunnar Wallin
Original assignee: BERGTEAMET AB
Current assignee: BERGTEAMET AB
Priority date: 2011-02-24
Filing date: 2012-02-10
Publication date: 2014-01-01
Also published as: SE535784C2; CL2013002457A1; EP2678262A4; SE1150161A1; WO2012115567A1

Abstract

The present invention concerns a mobile crane (1 ) intended to be used during work in a mine, comprising a crane chassis (2) with a combustion engine (4) for the transport of the mobile crane (1 ) to the work site, a power transfer system (18, 37, 40 [sic, "40" is the electrical cabinet]) for the operation of working functions in the form of a crane arm (13) mounted to pivot in the plane (15) of the crane chassis, which crane arm can be moved between a position lowered against the crane chassis and an elevated position, and between a withdrawn position and an extended position, a frame (23) arranged at the crane chassis (2) with a winch (24) or a winch with a line drum (27) for the winching of a load wire (21 ), and an operating compartment (5) for the operation of the mobile crane. It comprises an electric motor (38) that drives the power transfer system (18, 37, 40) for the operation of the working functions of the mobile crane at the work site when the combustion engine (4) has been switched off. The invention concerns also the use of a mobile crane for work in a mine.

Description

Mobile Crane

The present invention concerns a crane, in particular a mobile crane for use in a mine according to the introduction to claim 1 .

Mobile cranes to be used at building sites for high and heavy lifting are previously known. These are powered by a combustion engine, both for transport of the crane and for operation of the working functions of the crane. The combustion engine emits large quantities of harmful emissions in the form of exhaust gases. It comprises further a crane arm that can be pivoted in the plane of the vehicle. This arm can be manoeuvred in a vertical direction and is, in addition, often telescopic, i.e. it can be extended out from a withdrawn position. A winch with a line drum is arranged in connection with the crane arm. The tip of the crane arm is provided with one or several pulley wheels over which the wire runs. The work that is to be carried out requires a wire that is somewhat longer that the total length of the crane arm. For this reason, it is not necessary to monitor how much of the wire has been wound out from the line drum.

Cranes that are used in mines are most often of stationary type. Once the crane has been installed in its location, it must be inspected with respect to safety, before it may be used. It is sometimes necessary to move the crane due to an exchange of working location or for reasons of safety. This means that the crane must again be inspected when it has been installed in its new location, and this leads to both high costs and an extensive consumption of time.

The purpose of the present invention is to achieve a mobile crane that can be used in a mine, and that is inspected only once a year, as specified in safety regulations. A second purpose is to achieve a mobile crane with a wire that has a length that is considerably longer than the total length of the crane arm, since a mine reaches to a large depth underground. A further purpose is to offer a mobile crane with safety arrangements that make it safe to carry out lifting operations on people. A further purpose is to offer a mobile crane that can be inspected together with a working platform.

These purposes are achieved through a mobile crane that demonstrates the distinctive features that are defined in the characterising parts of the claims.

One preferred embodiment will be described below with reference to the attached drawings, of which: Figure 1 shows a side view of a mobile crane according to the invention, and Figure 2 shows two different types of control panel.

The mobile crane 1 shown in Figure 1 comprises a mobile motor-driven crane chassis 2, also known as the "mobile crane". The crane chassis in this example is provided with wheels 3: in another embodiment it can be provided with tracks. The mobile crane is driven with the aid of a combustion engine 4, normally a diesel engine. The mobile crane is operated during transport from a driver's cabin 5 with the customary equipment such as control panel 6, steering wheel 7, pedals 8, switches 9 and a gear-changing arrangement 10. The crane chassis further comprises support legs 1 1 , and it is an advantage that there be one support leg at each corner. The support legs are arranged with support leg monitors, not shown in the drawings, in the form of sensors that indicate whether the support legs are protruded or withdrawn. Operation of the support legs takes place with the aid of hydraulic cylinders 12. These hydraulic cylinders are fed in known manner with a flow of hydraulic fluid from a hydraulic pump (not shown in the drawings) that is driven by the combustion engine.

The crane chassis further comprises a crane arm 13 or boom that can be operated hydraulically. The crane arm 13 is mounted on a turntable 14 and it can pivot in the plane 15 of the chassis. Further, the crane arm 13 is telescopic in a known manner, i.e. it comprises a principal part 16 and a part 17 that can be extended and that is mounted inside of the principal part. The crane arm 13 is mounted jointed at the turntable 14 and it can be manoeuvred in the vertical direction with the aid of hydraulic cylinders 18. At the outermost free end 19 of the crane arm 13 a pulley wheel 20 for the control of a wire 21 is arranged. At least one excess winching switch 22 is located in association with the pulley wheel 20. The function of the excess winching switch 22 will be described below. The motion of the crane arm 13, such as oscillation, raising, lowering and extension, is regulated with respect to safety in known manner in order to avoid the crane arm colliding with any other part of the mobile crane 1 .

A frame 23 with a principal winch 24 is arranged in association with the crane chassis 2 and the crane arm 13. The principal winch 24 comprises a hydraulic pump 25 that is driven by an electrical motor 26 and a line drum 27 that is driven by a hydraulic motor 28. The said line or wire 21 is wound onto the line drum 27. The winch 24 is further arranged with a counter 29 that counts the number of turns of the wire that has been wound onto the drum 27. In addition, a counter 30 is arranged that counts the number of layers of line that is present on the drum 27. Finally, a speed measurer 31 is arranged, which measures the speed with which the wire is wound onto and off from the line drum 27. The purpose of this is to avoid the line or wire being fully wound off from the drum during operation. The counters and the measurers 29, 30 and 31 are of commonly used types, for example optical, electrical or mechanical arrangements.

An attachment arrangement 33, for example a lifting hook or a working platform 33a, is arranged at the free end 32 of the wire 21 . In order to prevent the attachment arrangement 33 being drawn over the pulley wheel 20, i.e. to avoid the wire 21 being wound in too far, the excess winching switch 22 breaks the power supply to the winch 24, when the attachment arrangement 33 approaches the excess winching switch, with the aid of a sensor 34 arranged at the wire 21 , in association with the attachment arrangement 33.

A measurer 35 is arranged between the frame 23 and the winch 24, which measurer measures the moment of the force or the moment of the load between the frame and the winch, the purpose of which is to avoid overload of the construction. The measurer 35 may be in the form of a strain gauge or a load gauge, which indicates the strain or the load between the frame 23 and the winch 24.

An angle sensor 36 is arranged between the crane chassis 2 and the crane arm 13. The angle sensor 36 measures the angle between the crane arm 13 and the crane chassis 2, which angle is used in the calculation of the force to which the crane arm is subject during operation.

A force transfer system is arranged at the chassis 2 and comprises a hydraulic system 37 for the delivery of a flow of hydraulic fluid under pressure to the hydraulically operated units, and for the operation of these when the mobile crane is located at its intended work site. The phrase "hydraulically operated units, and the operation of these" is here used to denote the driving of the winch 24, the raising and lowering of the crane arm, the extension or withdrawal of the telescopic part, and the rotation of the crane arm on the turntable. The hydraulic system 37 is driven by an electrical motor 38 that drives a hydraulic pump 39 and that places a fluid under pressure, which fluid is fed by pipes and valves, not shown in the drawings, to the hydraulically operated units. Thus, the hydraulic system is not connected to the motor 4 that drives the mobile crane 1 during the manoeuvring of the mobile crane 1 to its working site.

In order to activate the hydraulic system 37 and the winch 24, an electrical cabinet 40 at the mobile crane 1 is connected to the electrical grid, for example a 400 V grid, of the mine. The connection takes place through a multipole contact 41 or a cable connector to the electrical cabinet 40, from which current is led to the intended parts. The parts and functions of the mobile crane are in this way controlled and operated at the worksite inside the mine without the emission of exhaust gases.

The said control and operation take place with the aid of a control panel 42, which is shown in Figure 2. This control panel is separate from the control panel 6 that is present inside the driver's cabin 5. The control panel 42 comprises controls 43 for the operation of the winch 24 and the crane arm 13. The control panel 42 is in signal-transferring connection with the mobile crane 1 through wireless signals 44, for example radio signals, sound signals or light signals. It should, however, be realised that the transfer of signals may also take place through a cable. The advantage of wireless connection is that the control panel 42 can be placed into the working platform 33a or the basket that is to be lowered down the shaft. The personnel who are in the basket down in the shaft can in this way control the basket with high precision.

A rescue winch 45 with a line drum 46 is arranged at the crane arm 13. The term "rescue winch" is here used to denote a winch that is similar to the principal winch 24 described above, but that has been dimensioned such that it can only cope with the load from a basket with space for one or several people, without equipment. The purpose of the rescue winch 45 is to be able to rapidly rescue personnel who are present in a shaft, without the need to move the mobile crane 1 . The rescue winch 45 is located at the crane arm 13 in front of the crane chassis 2, and it is equipped with measurers for the number of turns of the line, the number of layers of line and the speed of the line. A rescue wire 48 passes from the rescue winch 45 over a pulley wheel 49 arranged in association with the tip 19 of the crane arm 13.

A control wire 50 passes from the rescue winch 45 in the direction towards the tip 19 of the crane arm, and demonstrates a snatch block 51 . An excess winching switch 52 is arranged in association with the snatch block 51 . The rescue wire 48 passes from the pulley wheel 49 at the tip 19 of the crane arm onwards through the snatch block 51 and is attached at a suspended rescue basket 53. The rescue basket 53 can be displaced in the direction along the crane arm 13, away from or towards the chassis 2, by adjusting the length of the control wire 50. The rescue basket 52 can in this way be manoeuvred down into a shaft X and past obstacles that may be present in the shaft, in order to reach personnel in need.

The rescue winch comprises a hydraulic motor 54 that drives a line drum 55. The hydraulic motor is normally driven by the hydraulic system 37 described above, but it can be driven also by the same hydraulic system that drives the support legs 1 1 . This gives the advantage that in the event of an interruption in power supply occurring in the mine, personnel who are present in a shaft can be fetched up in a simple manner. The rescue winch is controlled from its own control panel 56 that can be seen in Figure 2, or from the control panel 6 in the driver's cabin 5 of the mobile crane.

When the crane is to be used, the mobile crane 1 is driven into the mine and transported to the location at which the work is to be carried out. The mobile crane when it is being driven is driven with the aid of the combustion engine 4. When it arrives at the intended location, for example a shaft X, the support legs 1 1 are extended outwards and downwards, and the mobile crane 1 is set into a horizontal position. A signal is given from the support legs to the control panel 6 when this position has been reached. This signal, for example in the form of signal lamps 57, continues as long as the support legs are extended. This gives the driver the possibility of ensuring that the horizontal position of the mobile crane is maintained, and that no attempt is made to move the mobile crane with the support legs in their extended positions.

The combustion engine is subsequently switched off, and the electrical cabinet 40 of the mobile crane is connected through a power cable to the electrical grid of the mine. The power supply to the combustion engine 4 is interrupted when this connection has been established, such that the combustion engine cannot be started. This ensures that the engine cannot be started and that no unnecessary exhaust gas emission takes place, and it ensures that the driving wheels 3 of the mobile crane cannot be rotated by mistake. If an interruption in power supply occurs in the electrical grid of the mine, the power supply cable is disconnected from the mobile crane, after which the engine of the mobile crane can be started and the rescue winch 45 can be used.

When the mobile crane 1 has reached the desired position, it can be inspected together with the equipment that may be used. A basket 33a for the lifting of personnel has been described above, but other equipment may be used, such as equipment for demolition or for drilling, that is mounted at the tip 19 of the crane arm. The inspection is carried out together with such equipment, basket for lifting personnel and the rescue basket, and the mobile crane can in this way be used in the manner intended within the relevant area, without needing to be inspected again after each displacement. The present invention is not limited to what has been described above and shown in the drawings: it can be changed and modified in several different ways within the scope of the innovative concept defined by the attached patent claims.

Claims

1. A mobile crane (1 ) intended to be used during work in a mine, comprising a crane chassis (2) with a combustion engine (4) and a hydraulic pump for the transport of the mobile crane (1 ) to the work site, a power transfer system (18, 37, 39) for the operation of working functions in the form of a crane arm (13) mounted to pivot in the plane (15) of the crane chassis, which crane arm can be moved between a position lowered against the crane chassis and an elevated position, and between a withdrawn position and an extended position, a frame (23) arranged at the crane chassis (2) with a winch (24) or a winch with a line drum (27) for the winching of a load wire (21 ), an operating compartment (5) for the operation of the mobile crane and connectors (40, 41 ) for the connection to an electrical grid arranged in the mine, characterised in that it comprises an electric motor (38) that drives the power transfer system (18, 37, 39) for the operation of the working functions of the mobile crane at the work site when the combustion engine (4) has been switched off, and in that the connectors (40, 41 ) are so designed that they prevent the engine being started when they are connected to the electrical grid.

2. The mobile crane according to claim 1 , whereby it comprises a control panel (42) separate from the operating compartment (5) for controlling the motions of the crane arm (13) and the winch (24).

3. The mobile crane according to claim 2, whereby the control takes place in a wireless manner.

4. The mobile crane according to claim 2, whereby the winch (24) is arranged with an electrical motor (26) that drives a hydraulic pump (25) and a hydraulic motor (28) by which a wire drum (27) is rotated through signals from the control panel (42).

5. The mobile crane according to claim 1 , whereby the connectors (40, 41 ) comprise an electrical cabinet and a contact.

6. The mobile crane according to any one of the preceding claims, whereby the winch (24) is driven by electricity from the electrical grid of the mine.

7. The mobile crane according to any one of the preceding claims, whereby the winch (24) comprises a revolution counter (29).

8. The mobile crane according to claim 7, whereby the revolution counter (29) counts the number of turns of the wire around the drum (27).

9. The mobile crane according to any one of the preceding claims, whereby the winch (24) comprises a counter (30) that counts the number of layers of line on the drum (27).

10. The mobile crane according to any one of the preceding claims, whereby the winch (24) comprises a speed measurer (31 ) that measures the speed of rotation of the line drum (27).

1 1 . The mobile crane according to any one of the preceding claims, whereby it comprises a measurer (35) arranged between the winch (24) and the frame (23) for the measurement of the moment of the force between the winch and the frame.

12. The mobile crane according to any one of the preceding claims, whereby the tip (19) of the crane arm (13) comprises a pulley wheel (20) with an excess winching switch (22, 34).

13. The mobile crane according to any one of the preceding claims, whereby the crane arm (13) comprises a measurer (36) for measurement of the angle of the crane arm (13) with the crane chassis (2).

14. The mobile crane according to any one of the preceding claims, whereby the crane arm (13) comprises a hydraulically powered rescue winch (45).

15. The mobile crane according to claim 14, whereby the rescue winch (45) is driven by the hydraulic pump of the transport engine (4), which supplies a flow of hydraulic fluid to a hydraulic motor (54) by which a wire drum (55) is rotated.

16. The mobile crane according to claim 14, whereby the rescue winch (45) is arranged to manoeuvre a rescue basket (53) that can be displaced along the crane arm (13) in its longitudinal direction with the aid of a control wire (50) that can be controlled from the winch.

17. The mobile crane according to any one of the preceding claims, whereby the crane chassis comprises support legs (1 1 ) with position indicators.

18. The use of a mobile crane according to claim 1 for work in a mine, characterised in that the mobile crane (1 ) is driven to the work site through propulsion by the combustion engine (4) and set into a horizontal position, that the combustion engine is switched off, that the mobile crane is connected to the electrical grid of the mine whereby the combustion engine is prevented from starting, after which the winch (24) of the mobile crane is operated via a hydraulic pump that is driven by electricity from the electrical grid, and the functions of the crane (13) are driven by a hydraulic system that is set under pressure by a hydraulic pump (39) that is driven by an electric motor (38) that is powered from the electrical grid.