TOWER CRANE WITH A DETECTION OF A ROTATING PART AUTOROTATION OR OSCILLATION STATE IN AN OUT OF SERVICE CONFIGURATION

Abstract

Tower crane (1) comprising a tower (2) on which a rotating portion (3) is pivotally mounted and configurable between a service configuration in which the rotating portion can be rotatably driven by means of a motorized orientation system (40), and an out of service configuration in which the rotating portion is rotatably released to be able to be oriented in the direction of the wind, where a control/command unit (5) activates a monitoring mode in the out of service configuration to detect, depending on variations in the angle of orientation or the angular speed of the rotating portion, if the rotating portion is in one of the following instability states: an autorotation state corresponding to a rotary movement of the rotating portion in a given direction over at least one complete turn; or an oscillation state corresponding to a back and forth movement of the rotating portion about the orientation axis.

Claims

1-16. (canceled)

17. A tower crane comprising: a tower on which a rotating portion is pivotally mounted along an orientation axis by a pivot mechanism, the pivot mechanism including at least a motorized orientation system, a mechanical orientation brake and an angular detector configured to detect an orientation angle of the rotating portion, wherein the tower crane is configurable between a service configuration in which the rotating portion is rotatably driven on the tower along the orientation axis by the motorized orientation system, and an out of service configuration in which the rotating portion is rotatably released on the tower according to the orientation axis for orientation in a direction corresponding to a wind direction, the mechanical orientation brake being deactivated in the out of service configuration; a control/command unit connected to the motorized orientation system, the mechanical orientation brake and the angular detector, wherein, in the out of service configuration, the control/command unit activates a monitoring mode in which the control/command unit detects, as a function of variations in the angle of orientation of the rotating portion or as a function of variations of an angular speed of the rotating portion established from the variations of the orientation angle, if the rotating portion is in one of the following movement states: an autorotation state corresponding to a rotary movement of the rotating portion in a given direction over at least one complete turn, wherein a variation of the orientation angle according to an angular amplitude is at least greater than one angular autorotation threshold of at least 360 degrees in a first given time interval or at an angular speed greater than a given autorotation speed threshold, and an oscillation state corresponding to a back and forth movement of the rotating portion about the orientation axis, wherein at least one cycle of variations of the angle of orientation includes movement of the rotating portion in a first direction then in a second direction, opposite to the first direction, and wherein an angular displacement of the orientation angle is at least equal to an angular oscillation threshold comprised between 20 and 180 degrees in a given second time interval or at an angular speed greater than a given oscillation speed threshold.

18. The tower crane according to claim 17, wherein, in the service configuration, the control/command unit deactivates the monitoring mode.

19. The tower crane according to claim 17, comprising at least one anemometer for measuring a wind speed, the anemometer connected to the control/command unit, and in which, in the monitoring mode, the control/command unit detects a movement state also depending on the wind speed.

20. The tower crane according to claim 17, wherein, in the monitoring mode, if a movement state is detected, then the control/command unit records a movement event defined by a recording of a dating of the movement state and of one or more movement parameters chosen from: variations in the angle of orientation; angular speeds or at least a maximum angular speed during the movement state; the angular amplitude for the autorotation state; and the angular displacement for the oscillation state.

21. The tower crane according to claim 19, wherein, in the monitoring mode, if a movement state is detected, then the control/command unit records a movement event defined by a recording of a dating of the movement state and of one or more movement parameters chosen from: variations in the angle of orientation, angular speeds or at least a maximum angular speed during the movement state, the angular amplitude for the autorotation state, and the angular displacement for the oscillation state, and wherein, in the monitoring mode, if a movement state is detected, then the control/command unit registers in the movement event also changes in wind speed or average wind speed or maximum wind speed during the movement state.

22. The tower crane according to claim 20, wherein the control/command unit triggers a transmission to a third party of a preventive message containing the movement event.

23. The tower crane according to claim 17, wherein, in the monitoring mode, the control/command unit detects whether the movement state corresponds to one of the following high movement states: an autorotation state in which the angular amplitude is greater than a high angular autorotation threshold in the first given time interval, the high angular autorotation threshold being greater than the angular autorotation threshold; and an autorotation state in which the angular speed is greater than a high autorotation speed threshold, the high autorotation speed threshold being greater than the autorotation speed threshold, wherein, when such a high movement state is detected, then the control/command unit triggers at least one alert action.

24. The tower crane according to claim 19, wherein, in the monitoring mode, the control/command unit detects whether the movement state corresponds to one of the following high movement states: an autorotation state in which the angular amplitude is greater than a high angular autorotation threshold in the first given time interval, the high angular autorotation threshold being greater than the angular autorotation threshold; and an autorotation state in which the angular speed is greater than a high autorotation speed threshold, the high autorotation speed threshold being greater than the autorotation speed threshold, wherein when one of the high movement states is detected, then the control/command unit triggers at least one alert action, and wherein another high movement state corresponds to an autorotation state in which the angular speed is between the autorotation speed threshold and the high autorotation speed threshold, and the wind speed is above a high wind speed threshold.

25. The tower crane according to claim 24, wherein the high wind speed threshold is between 10 and 20 m/s.

26. The tower crane according to claim 25, wherein the high wind speed threshold is between 14 and 20 m/s.

27. The tower crane according to claim 23, wherein the alert action comprises an activation of a sound or light local alarm.

28. The tower crane according to claim 23, wherein the alert action comprises transmitting an alarm message to a remote entity.

29. The tower crane according to claim 23, wherein the alert action comprises a transmission to a third party of a warning message informing of a detection of a critical instability state.

30. The tower crane according to claim 23, wherein the alert action comprises activating the mechanical orientation brake.

31. The tower crane according to claim 23, wherein the alert action comprises an activation of the motorized orientation system to generate a braking torque opposite to the rotation of the rotating portion.

32. A method for monitoring a tower crane comprising a tower on which a rotating portion is pivotally mounted along an orientation axis by of a pivot mechanism, the pivot mechanism including at least a motorized orientation system, a mechanical orientation brake and an angular detector configured to detect an orientation angle of the rotating portion, wherein the tower crane is configurable between a service configuration in which the rotating portion is rotatably driven on the tower along the orientation axis by the motorized orientation system, and an out of service configuration in which the rotating portion is rotatably released on the tower along the orientation axis for orientation in a direction corresponding to a wind direction, the mechanical orientation brake being deactivated in the out of service configuration, wherein the tower crane further comprises a control/command unit connected to the motorized orientation system and to the angular detector, the monitoring method comprising: in the out of service configuration, activating a monitoring mode in which the control/command unit detects, as a function of variations in the angle of orientation of the rotating portion or as a function of variations of an angular speed of the rotating portion established from the variations in the orientation angle, if the rotating portion is in one of the following movement states: in an autorotation state, corresponding to a rotary movement of the rotating portion in a given direction over at least one complete turn, wherein a variation of the orientation angle according to an angular amplitude is at least greater than an angular autorotation threshold of at least 360 degrees in a first given time interval or at an angular speed greater than a given autorotation speed threshold, and in an oscillation state, corresponding to a back and forth movement of the rotating portion about the orientation axis, wherein at least one cycle of variations of the angle of orientation includes movement of the rotating portion in a first direction then in a second direction, opposite to the first direction, and wherein an angular displacement of the orientation angle is at least equal to an angular oscillation threshold comprised between 20 and 180 degrees in a second interval of given time or at an angular speed greater than a given oscillation speed threshold.

33. The monitoring method according to claim 32, comprising, in the service configuration, deactivating the monitoring mode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Other characteristics and advantages of the present invention will become apparent on reading the detailed description below, of a non-limiting example of implementation, made with reference to the appended figures in which:

[0061] FIG. 1 is a schematic side view of a tower crane according to an embodiment;

[0062] FIG. 2 is a schematic top view of a tower crane according to an embodiment;

[0063] FIG. 3 is a schematic top view of a tower crane in a autorotation state; and

[0064] FIG. 4 is a schematic top view of a tower crane in an oscillation state.

DESCRIPTION

[0065] Referring to FIG. 1, a tower crane 1 according to embodiments herein comprises a tower 2 (also called a mast) extending along an orientation axis 20 which is vertical, where the tower 2 rests on a ground and has a top on which is pivotally mounted a rotating portion 3 along the orientation axis 20, as diagrammatically shown by the arrow «OR».

[0066] This rotating portion 3 comprises an assembly forming a pivot 30 rotary mounted on the top of the tower 2 along the orientation axis 20, as well as an arrow 31 mounted on the assembly forming a pivot 30. A distribution and lifting system load 32 is mounted on the boom 31 to distribute and raise/lower a load along the boom 31. The rotating portion 3 may also comprise a counter-boom 33 mounted on the pivot assembly 30, opposite to the boom 31, and one or more weights 34 can be mounted on a counter-boom 33. The rotating portion 3 further comprises a pilot cabin 35, placed on the assembly forming a pivot 30 at the level of the foot of the boom 31. It is conceivable to have a boom holder 36 or punch which is vertically mounted on the assembly forming a pivot 30, to carry the boom 31, and possibly the counter-boom 33, for example by means of shrouds.

[0067] The rotating portion 3 is pivotally mounted by means of a pivot mechanism 4 provided on the pivot assembly 30, where this pivot mechanism 4 includes a motorized orientation system 40 which comprises: [0068] a fixed pivot intended to be fixedly attached to the top of the tower 2, which is in the form of a toothed orientation ring 41; [0069] a rotating pivot rotatably coupled to the fixed pivot along the orientation axis 20, which is in the form of an annular bearing resting on the orientation ring 41; [0070] at least one orientation electric motor 42 provided with a pinion meshing with the orientation ring 41; and [0071] a variator 43 connected to the orientation electric motor 42 to adjust its speed and torque.

[0072] This pivoting mechanism 4 also includes: [0073] a mechanical orientation brake 44; and [0074] an angular detector 45 capable of detecting an orientation angle of the rotating portion 3 about the orientation axis 20.

[0075] The tower crane 1 also comprises a control/command unit 5 connected: [0076] to the motorized orientation system 40, and more specifically to the variator 43, in order to drive the orientation of the rotating portion 3; [0077] to the mechanical orientation brake 44 in order to activate this brake to block/brake the orientation of the rotating portion 3; and [0078] to the angular detector 45 in order to recover the variations in the orientation angle of the rotating portion 3.

[0079] This tower crane 1 is configurable between: [0080] a service configuration in which the rotating portion 3 can be driven in rotation on the tower 2 along the orientation axis 20 by driving the motorized orientation system 40 by means of the control/command unit 5, and [0081] an out of service configuration in which the rotating portion 3 is released in rotation on the tower 2 along the orientation axis 20 in order to be able to be oriented in the direction of the wind, the mechanical orientation brake 44 being deactivated and the motorized orientation system 40 being disengaged in the out of service configuration.

[0082] When tower crane 1 is in the out of service configuration, the control/command unit 5 activates a monitoring mode in which the control/command unit 5: [0083] receives, coming from the angular detector 45, the variations in the orientation angle of the rotating portion 3; [0084] establishes, from the variations in the orientation angle of the rotating portion 3, the variations of an angular speed of the rotating portion 3.

[0085] The control/command unit 5 deactivates this monitoring mode when the tower crane 1 is in the service configuration.

[0086] In this monitoring mode, the control/command unit 5 detects, as a function of the variations in the orientation angle and/or as a function of the variations in the angular speed, whether the rotating portion is in one of the following movement states: [0087] an autorotation state, illustrated in FIG. 3, corresponding to a rotary movement of the rotating portion 3 about the orientation axis 20 in a given direction over at least one complete turn, as diagrammatically shown by the arrow «TR»; or [0088] an oscillation state, illustrated in FIG. 4, corresponding to a back and forth movement of the rotating portion 3 about the orientation axis 20, as diagrammatically shown by the arrow «VV».

[0089] The autorotation state is characterized by a variation of the orientation angle according to an angular amplitude at least greater than an angular autorotation threshold SAAR of at least 360 degrees in a first given time interval T1 or at an angular speed greater than a given autorotation speed threshold SVAR.

[0090] By way of example, the angular autorotation threshold SAAR is 360 degrees, in other words the autorotation state is detected from a full turn in the first time interval T1 which is in particular at most 10 minutes, and for example in the range of 5 to 10 minutes. In this case, the autorotation state is detected if the rotating portion 3 makes at least one complete turn in less than T1 minutes, and for example in less than 10 minutes if T1 is equal to 10 minutes. Alternatively or in addition, the autorotation speed threshold SVAR can be at least 6 t/h (turns per hour). In this case, the autorotation state is detected if the rotating portion 3 makes at least one complete turn with an angular speed greater than or equal to 6 t/h.

[0091] The oscillation state is characterized by at least one cycle of variations of the orientation angle in a first direction then in a second direction, opposite to the first direction (in other words at least one round trip or back and forth cycle), characterized by an angular displacement DA of the orientation angle at least equal to an angular oscillation threshold SAO comprised between 20 and 180 degrees in a second given time interval T2 or at an angular speed greater than a given oscillation speed threshold SVO.

[0092] For example, the angular oscillation threshold SAO is 20 degrees, in other words the oscillation state is detected from a back and forth movement according to an angular displacement DA greater than or equal to 20 degrees in the second time interval T2 which is in particular at most 5 minutes, and for example in the range of 2 to 5 minutes. In this case, the oscillation state is detected if the rotating portion 3 moves back and forth with an angular movement of at least 20 degrees in less than T2 minutes, and for example in less than 5 minutes if T2 is equal to 5 minutes. It should be noted that when back and forth according to an angular displacement DA, the rotating portion 3 rotates by DA degrees in one direction and then by DA degrees in the other direction. Alternatively or in addition, the oscillation speed threshold SVO can be at least 1.3 t/h (turns per hour). In this case, the oscillation state is detected if the rotating portion 3 moves back and forth with an angular movement of at least 20 degrees with an angular speed greater than or equal to 1.3 t/h.

[0093] Moreover, it is conceivable that the tower crane 1 comprises at least one anemometer 8 suitable for measuring a wind speed and connected to the control/command unit 5. Thus, in the monitoring mode, the control/command unit 5 detects a movement state also as a function of the wind speed, and further, a high movement state as described later.

[0094] In the monitoring mode, if a movement state is detected, then the control/command unit 5 records in a memory 50 a movement event defined by recording: [0095] dating (day and time) of the movement state, [0096] variations in wind speed or average wind speed or maximum wind speed during the movement state;

[0097] and also a recording of one or more movement parameters selected from: [0098] variations in the angle of orientation; [0099] angular speeds or at least a maximum angular velocity during the movement state; [0100] the angular amplitude for an autorotation state; [0101] the angular displacement DA for an oscillation state.

[0102] The tower crane 1 also comprises a wired or wireless transmitter 7, connected to the control/command unit 5, so that the control/command unit 5 triggers a transmission by the transmitter 7 to a third party of a preventive message containing the movement event, with all associated recorded data such as dating, wind speed and movement parameter(s).

[0103] In the monitoring mode, the control/command unit 5 also detects whether the movement state corresponds to one of the following high movement states, established regardless of the wind speed: [0104] an autorotation state in which the angular amplitude is greater than a high angular autorotation threshold SCAAR in the first time interval T1 given, this high angular autorotation threshold SCAAR being greater than the angular autorotation threshold SAAR; [0105] an autorotation state in which the angular speed is greater than a high autorotation speed threshold SCVAR, this high autorotation speed threshold SCVAR being greater than the autorotation speed threshold SVAR.

[0106] In the example above, the angular autorotation threshold SAAR is 360 degrees, and for example the high angular autorotation threshold SCAAR is 720 degrees (namely 2 turns). In this case, the high movement state is detected if the rotating portion 3 makes at least two turns in less than T1 minutes, and for example in less than 10 minutes if T1 is equal to 10 minutes.

[0107] In the example above, the autorotation speed threshold SVAR is 6 t/h, and for example the high autorotation speed threshold SCVAR is 12 t/h. In this case, the high movement state is detected if the rotating portion 3 makes at least one complete turn with an angular speed greater than or equal to 12 t/h.

[0108] In an advantageous version, the wind speed is taken into consideration to characterize another high movement state, which corresponds to an autorotation state in which the angular speed is comprised between the autorotation speed threshold SVAR and the high autorotation speed threshold SCVAR, and the wind speed is greater than a high wind speed threshold SCVV, which is for example comprised between 10 and 20 m/s, and in particular between 14 and 20 m/s.

[0109] In the example above, the autorotation speed threshold SVAR is 6 t/h, and the high autorotation speed threshold SCVAR is 12 t/h. In the example above, the high autorotation speed threshold SCVAR is 9 t/h. In this case, the high movement state is detected if the rotating portion 3 makes at least one complete turn with an angular speed between 6 t/h and 12 t/h, and if (double condition) the wind speed is greater than the high wind speed threshold SCVV which is for example 14 m/s.

[0110] When such a high movement state is detected, then the control/command unit 5 triggers at least one alert action, such as for example all or part of the alert actions in the list below: [0111] activation of a sound or light local alarm, the control/command unit 5 being connected to a local alarm generator 7, for example a loudspeaker in the example illustrated in FIG. 1; [0112] transmission of an alarm message to a remote entity, via the transmitter 6; [0113] transmission to a third party of a warning message informing of a detection of a high movement state, via the transmitter 6; [0114] activation of the mechanical orientation brake 44;

[0115] activation of the motorized orientation system 40 to generate a braking torque opposed to the rotation of the rotating portion 3.

[0116] According to an embodiment, the systems and/or methods herein, such as the method for monitoring a tower crane (1), may be implemented as, include, and/or be performed by one or more computers having a processor and a non-transitory computer-readable storage medium operably connected to the processor. The processor may be a microprocessor. The processor is configured to execute program instructions stored in the computer-readable storage medium to control operations of the crane, or components of the crane, according to the program instructions. In this manner, the methods, steps, operations, processes and the like of the tower crane (1) may be performed by way of one or more computers. In one example, the control/command unit (5) may be implemented as, or include, one or more such computers and/or processors, and may be configured to perform some or all of the methods, steps, operations, processes and the like described herein, including the method for monitoring the tower crane (1).