Patent Grant
11753284
The invention relates to a lifting crane comprising a jib and a double reeving lifting device designed to distribute and lift a load along the jib.
It relates more particularly to a lifting crane wherein the lifting device is reversibly configurable between two reeving configurations including a single reeving configuration with two lifting strands and a double reeving configuration with four lifting strands, and wherein the lifting device comprising a reeving change system allowing a reeving change between the single reeving configuration and the double reeving configuration.
The invention finds a preferred, and non-limiting, application in the field of the tower cranes.
In a known manner, a lifting crane includes a monitoring/control unit monitoring all crane movements in order to guarantee a correct use within the authorized limits of the crane, and in particular to guarantee the stability of the crane by permanently monitoring that the load suspended on the lifting device at the reach measured on the jib is less than a maximum load authorized by a predefined load curve.
In a known manner with electromechanical monitoring/control units, this function of monitoring the suspended load is carried out by a moment bar calculation which allows directly measuring an elastic deformation of the jib under the suspended load moment, with numerous drawbacks including the cost of such monitoring/control units and the complexity of implementation.
It is also known to calculate the suspended load from an actual lifting tension measured on at least one lifting strand (strand of the lifting cable partially supporting the load), then this lifting tension is multiplied by the number of lifting strands in action, which is two in single reeving configuration and four in double reeving configuration.
Also, it is necessary for the monitoring/control unit to be aware of the number of lifting strands, in other words of the reeving configuration between the single reeving configuration and the double reeving configuration.
Currently, the reeving configuration is known from a declarative mode, that is to say that it is the crane pilot who declares, on an interface, the current reeving configuration. Consequently, the stability of the crane, and therefore compliance with safety conditions, will depend on the correct statement of the reeving configuration by the pilot; it being noted that a poor consideration of the number of involved strands can lead to accepting an overload of a factor of 2 compared to the maximum authorized load, with serious consequences such as for example a tilting of the crane.
Thus, the invention proposes removing this declarative mode of the reeving configuration, and at the same time removing the aforementioned drawbacks associated to its implementation, mainly including the risks of false statements, erroneous statements or late statements.
To this end, the invention relates to a lifting crane comprising a jib and a lifting device with double reeving designed to distribute and lift a load along the jib, said lifting device being reversibly configurable between two reeving configurations including a single reeving configuration with two lifting strands and a double reeving configuration with four lifting strands, and the lifting device comprising a reeving change system allowing performing a reeving change between the single reeving configuration and the double reeving configuration, and vice versa, said lifting crane being remarkable in that it comprises a system for automated determination of the reeving designed to automatically determine the reeving configuration between the single reeving configuration and the double reeving configuration.
Thus, the invention is based on an automated mode of determining the reeving configuration, rather than on a declarative mode, which allows making the recognition of the reeving configuration more reliable and thus allows automatically changing the load curve (adaptation of the load curve depending on the number of lifting strands) without a decision by the crane operator, and by making sure to always have the correct load curve, in particular during the transition phases, throughout the reeving change.
The invention also allows making the recognition of the reeving configuration more reliable without using a moment bar calculation which, in addition to being expensive, is complicated to implement.
According to one feature, the lifting device comprises a distributing trolley comprising a structure suspended on the jib and connected to a distribution system capable of displacing the distributing trolley along the jib in a forward direction and a rearward direction which are opposite to each other, and a main block suspended from said suspended structure by a lifting cable;
the reeving change system comprises a secondary block and a locking/unlocking mechanism cooperating with the main block and the secondary block to pass from the single reeving configuration to the double reeving configuration or vice versa; and
the system for automated determination of the reeving comprises at least:
Thus, the automated determination of the reeving configuration is based on the detection of the absence/presence of the secondary block at a reference location, which has the advantage of having a reliable detection and thus an equally reliable reeving configuration determination.
According to one possibility, the system for automated determination of the reeving comprises a storage module connected to the monitoring/control unit for storing at least one last reeving configuration determined by the monitoring/control unit,
Thus, during a reeving change, the monitoring/control unit can determine the new reeving configuration and check whether this determination is consistent with the last reeving configuration stored in the memory. Also, the monitoring/control unit can check whether or not a reeving change has been successfully carried out, so as to be able to safely deduce the new reeving configuration and, once the new reeving configuration has been determined, the latter is stored in the storage module until the next reeving change.
According to another possibility:
In a first embodiment, the system for detecting the presence of the secondary block is configured to detect the presence/absence of the secondary block inside the block housing occupied by the secondary block in the single reeving configuration and/or at the location above the main block occupied by the secondary block in the double reeving configuration.
Thus in this first embodiment, the system for detecting the presence of the secondary block implements a direct detection of the presence/absence of the secondary block at a reference location; this reference location corresponding:
In a second embodiment, the reeving change system comprises a remaining trolley comprising a frame suspended on the jib and supporting the secondary block, wherein:
and the system for detecting the presence of the secondary block is configured to detect a presence/absence of the remaining trolley at the storage location.
Thus, in this second embodiment, the system for detecting the presence of the secondary block implements an indirect detection of the presence/absence of the secondary block at a reference location. Indeed, it is the remaining trolley which is detected as being present/absent at this storage location, in other words:
According to one variant, this storage location is located at the foot of the jib.
In a particular embodiment, the reeving change system passes the lifting device from the single reeving configuration to the double reeving configuration, and vice versa, by displacing the distributing trolley with the main block thereof, and the monitoring/control unit is connected to the distribution system to drive the displacement of the distributing trolley according to:
depending on the reeving configuration which is automatically determined by said monitoring/control unit.
Thanks to the automated detection of the reeving configuration, it is therefore now advantageous to drive, in an automated manner, the reeving changes, integrally or not from start to finish; just as it is conceivable that this driving comes under steering assistance, for example by monitoring or limiting the speeds and/or the acceleration and/or the braking and/or the stops
Advantageously, the monitoring/control unit is designed to enable:
Thus, the invention allows securing the reeving changes, and therefore avoiding erroneous operations.
In a particular embodiment, the lifting crane comprises a lifting winch provided with a lifting drum cooperating with the lifting cable to displace the load upward and downward, said lifting winch being equipped with an unwinding sensor capable of measuring an unwound length of the lifting cable, wherein the monitoring/control unit is designed to compare the unwound lengths of the lifting cable at the beginning of a first automated sequence and at the beginning of a second automated sequence which follows or precedes said first automated sequence.
According to one possibility, the monitoring/control unit is designed to automatically determine the reeving configuration also depending on the comparison between the unwound lengths of the lifting cable at the beginning of a first automated sequence and at the beginning of a second automated sequence which follows or precedes said first automated sequence.
Thus, this comparison allows making the determination of the reeving configuration even more reliable.
In an advantageous embodiment, a load sensor coupled to a lifting strand of the lifting cable for measuring a lifting tension on said lifting strand, wherein the monitoring/control unit is connected to the load sensor and is designed to calculate a value of the load depending on said lifting tension on said lifting strand and on the reeving configuration which is automatically determined by said monitoring/control unit.
The invention indeed finds an advantageous application for calculating a value of the load suspended from the lifting strands, reliably and without declarative mode, thus offering a reliable solution allowing overcoming human error and thus improving the safety level.
Alternatively, the monitoring/control unit is designed to compare the value of the load with a maximum authorized load.
The invention also relates to a driving method for driving a lifting crane according to the invention, as described above, comprising the steps of:
According to one feature, the driving method comprises the steps of:
Advantageously, the driving method comprises a step of storing at least one last automatically determined reeving configuration, and wherein the configuration of the lifting device is automatically determined also depending on said last stored reeving configuration.
According to another feature, the driving method comprises a step of driving the displacement of the distributing trolley according to:
Advantageously, the driving method comprises the step of enabling:
In a particular embodiment, the driving method comprises the steps of:
According to one possibility, the configuration of the lifting device is automatically determined also depending on the comparison between the unwound lengths of the lifting cable at the beginning of a first automated sequence and at the beginning of a second automated sequence which follows or precedes said first automated sequence.
According to another possibility, the driving method comprises the steps of:
Advantageously, the driving method comprises the step of comparing the value of the load with a maximum authorized load.
Other features and advantages of the present invention will appear on reading the detailed description below, of a non-limiting example of implementation, made with reference to the appended figures wherein:
With reference to the Figures, a lifting crane 1 according to the invention, of the tower crane type, comprises a distributing jib 2 mounted on a tower 3 (also called a mast) at the foot 20 of the jib 2. Conventionally, the foot 20 of the jib 2 is rotatably mounted on the tower 3 along a vertical axis. The jib 2 can be extended to the other side of tower 3 by a counter-jib 30, generally provided with ballasts.
The lifting crane 1 further includes a lifting device 4 with double reeving designed to distribute a load (not illustrated) along the jib 2, this lifting device 4 circulating on a rolling path formed on the jib 2, between the foot 20 and the tip 21 of the jib 2, also called the free end of the jib 2.
This lifting device 4 comprises a distributing trolley 5 which includes a structure 50 suspended on the rolling path by front and rear primary rolling members formed of rollers or wheels rolling on the rolling path. This suspended structure 50 supports pulleys which ensure the guiding of a lifting cable 40.
The suspended structure 50 is connected to a distribution system 55 capable of displacing the distributing trolley 5 along the rolling path in a forward direction (in other words in the direction of the tip 21 of jib 2, to the right in the Figures) and an opposite rear direction (in other words in the direction of the foot 20 of the jib 2, to the left in the Figures).
As schematized in
The distributing trolley 5 further comprises a main block 51 suspended from the suspended structure 50 by the lifting cable 40. This main block 51 supports a lifting member 52, in the lower portion; this lifting member 52 being provided for hooking the load and could be in the form of a hook hinged on the main block 51.
This lifting device 4 is reversibly configurable between two reeving configurations including:
The lifting device 4 comprises a reeving change system allowing reversibly performing a reeving change between the single reeving configuration and the double reeving configuration, and vice versa.
This reeving change system comprises a remaining trolley 6 which is movable on the rolling path. The remaining trolley 6 comprises a frame 60 suspended on the rolling path by front and rear secondary rolling members formed of rollers or wheels rolling on the rolling path. The suspended frame 40 is open on the front, enabling an entry/exit of the distributing trolley 3.
This reeving change system also comprises a secondary block 61 supported by the suspended frame 60 of the remaining trolley 6 in the double reeving configuration.
This reeving change system also comprises a locking/unlocking mechanism cooperating with the main block 51 and the secondary block 61 to pass from the single reeving configuration to the double reeving configuration or vice versa, so that:
In the embodiment which is illustrated in
Moreover, the lifting device 4 is arranged to pass from the single reeving configuration to the double reeving configuration, and vice versa, by displacing the distributing trolley 5 with the main block 51 thereof, and to do this the reeving change system and more specifically, the locking/unlocking mechanism thereof are designed to pass from the single reeving configuration to the double reeving configuration, and vice versa, by acting on the distribution system (in order to displace the distributing trolley 5) and on the lifting cable 40.
As schematized in
This type of lifting device 4 is described, in full and detailed manner, in the French patent applications No. FR 3 061 163 and No. FR 3 061 164, and those skilled in the art will usefully refer to these two French patent applications for further structural and functional details, and a summary of the reeving changes is proposed below; it being noted that the invention is not limited to this type of lifting device 4.
The lifting device 4 passes from the double reeving configuration to the single reeving configuration as follows:
The lifting device 4 passes from the single reeving configuration to the double reeving configuration as follows:
With reference to
This system for automated determination of the reeving 7 comprises at least:
This presence detection system 8 may comprise first means for detecting the presence/absence of the secondary block 61 inside the block housing 55 occupied by the secondary block 61 in the single reeving configuration. Thus, if the secondary block 61 is inside the block housing 55 then the lifting device 4 is in the single reeving configuration, and conversely if the secondary block 61 is absent from the block housing 55 then the lifting device 4 is in the double reeving configuration. This first means may for example comprise a contact sensor, a mechanical sensor, an electrical sensor, an optical sensor, etc., for example disposed in front of or inside the block housing 55.
This presence detection system 8 can comprise second means for detecting the presence/absence of the secondary block 61 at the location above the main block 51 occupied by the secondary block 61 in the double reeving configuration, and in particular the presence/absence of the secondary block 61 in suspension on the support members provided on the remaining trolley 6. Thus, if the secondary block 61 is present on the support members then the lifting device 4 is in the double reeving configuration, and conversely, if the secondary block 61 is absent from the support members then the lifting device 4 is in the single reeving configuration. This second means can for example comprise a contact sensor, a mechanical sensor, an electrical sensor, an optical sensor, etc. disposed for example in front of or on the support members.
This presence detection system 8 can comprise third means for detecting the presence/absence of the remaining trolley 6 at the storage location (under the foot 20 of the jib 2 in the illustrated embodiment), insofar as the presence/absence of the remaining trolley 6 at the storage location is correlated with the localization of the secondary block 61 and with the reeving configuration. Thus, if the remaining trolley 6 is present at the storage location then the lifting device 4 is in the single reeving configuration, and conversely if the remaining trolley 6 is absent from the storage location then the lifting device 4 is in the double reeving configuration.
This presence detection system 8 can comprise all or part of the first means, of the second means and of the third means described above.
In the illustrated embodiment, the presence detection system 8 comprises the third means, shown in
This stop 81 comprises a rod 82 extended by an enlarged head 83. The rod 82 is slidably mounted on the structural element 22 and, as such, the rod 82 passes through this structural element 22 into an orifice or bearing.
The rod 82 has a free front end provided with a stop surface 84 provided so that the remaining trolley 6 abuts against said stop surface 84. As such, the remaining trolley 6 may have, on the rear, a rear stopper 63 capable of bearing on the stop surface 84.
This stop surface 84 is enlarged relative to the rod 82, and is in particular in the form of a disc of a diameter which is greater than the diameter of the rod 82 if the latter is cylindrical.
The rod 82 has a rear end, opposite to the front end and therefore to the stop surface 84, on which the enlarged head 83 is fastened. Thus, the stop 81 has on either side of the structural element 22:
The enlarged head 83 has a detection surface 85 which is flat and inclined relative to a sliding direction of the stop 81 on the structural element 22.
There is also provided an elastic return member 86 interposed between the structural element 22 and the stop surface 84, wherein this return member 86 is in the form of a helical compression spring mounted around the rod 82.
The proximity sensor 80 is in turn fixedly mounted on the jib 2 and is disposed opposite to the detection surface 85 of the enlarged head 83 of the stop 81, wherein the proximity sensor 80 is configured to detect and measure the distance between said proximity sensor 80 and said detection surface 85. This proximity sensor 80 can for example be an inductive sensor or a light sensor (infrared sensor, etc.).
The stop 81 is selectively displaceable between:
In the detection position, the stop 81 has slid (rearwardly), compared to the rest position, which contributes to a modification of the distance between the proximity sensor 80 and the detection surface 85, and also to a compression of the return member 86 between the structural element 22 and the stop surface 84. It should be noted that the detection surface 85 is inclined in the direction of a reduction in the distance between the proximity sensor 80 and the detection surface 85 when the stop 81 has slid (rearwardly) from its rest position to the detection position.
As the proximity sensor 80 is configured to detect and measure the distance between the proximity sensor 80 and the detection surface 85, this proximity sensor 80 is then configured to detect the stop 81 in its rest position and in its detection position, wherein:
Thus, the monitoring/control unit 9 allows automatically determining the reeving configuration depending on the detection operated by the presence detection system 8.
Advantageously, the system for automated determination of the reeving 7 comprises a storage module 90 (or memory) connected to the monitoring/control unit 9 to store at least one last reeving configuration determined by the monitoring/control unit. 9. In other words, the last reeving configuration is stored in this storage module 90, such that when a reeving change is operated, the monitoring/control unit 9 is designed to automatically determine the reeving configuration also depending on this last reeving configuration which is stored in the storage module.
Once the new reeving configuration has been determined, based on the at least one detection made by the presence detection system 8 and the last stored reeving configuration, it is this new reeving configuration which is stored in the storage module 90 and which therefore becomes the last reeving configuration. In other words, the reeving configuration is updated in the storage module 90 at each reeving change.
As schematized in
depending on the reeving configuration which is automatically determined by this monitoring/control unit 9.
Also, the monitoring/control unit 9 can enable:
The monitoring/control unit 9 can also be connected to an unwinding sensor provided on the lifting winch 47 and capable of measuring an unwound length of the lifting cable 40. Thus, the monitoring/control unit 9 can compare the unwound lengths of the lifting cable 40 at the beginning of a first automated sequence and at the beginning of a second automated sequence which follows or precedes this first automated sequence, and the monitoring/control unit 9 can thus automatically determine the reeving configuration also depending on this comparison between the unwound lengths of the lifting cable 40.
If these unwound lengths of the lifting cable 40 are not equivalent, then the monitoring/control unit 9 establishes the presence of an error and automatically restarts the current sequence and/or emits an alarm.
Thus, during a first automated sequence, the monitoring/control unit 9 supervises the proper conduct as follows:
At the end of these steps, the monitoring/control unit 9 confirms that the reeving configuration is the double reeving configuration if no error has been detected, and memorizes this double reeving configuration in the storage module 90.
Likewise, during a second automated sequence, the monitoring/control unit 9 supervises the proper conduct as follows:
At the end of these steps, the monitoring/control unit 9 confirms that the reeving configuration is the single reeving configuration if no error has been detected, and memorizes this single reeving configuration in the storage module 90.
With reference to
In this case, the monitoring/control unit 9 is connected to this load sensor 91 and is designed to calculate a value of the load depending on the lifting tension measured on this lifting strand and on the reeving configuration which is automatically determined by the monitoring/control unit 9, insofar as a single reeving configuration corresponds to a distribution of the load on two lifting strands, and a double reeving configuration corresponds to a distribution of the load on four lifting strands.
Thus, the monitoring/control unit 9 can compare the value of the load with a maximum authorized load, and consequently the monitoring/control unit 9 can act on the displacement of the distributing trolley 5 and the displacement of the lifting cable 40 if the maximum authorized load is exceeded, and can in particular stop any displacement of the load if the maximum authorized load is exceeded.
The system for automated determination of the reeving, and/or components thereof, may be implemented as, or include, one or more computers having a processor and a non-transitory computer-readable storage medium operably connected to the processor. The one or more computers may also include a communication module configured to facilitate communication (i.e., to transmit and/or receive information) with other components of the system for automated determination of the reeving and/or of the lifting crane. 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 lifting crane, or components of the lifting crane, according to the program instructions. In this manner, the methods, steps, operations, processes and the like of the system for automated determination of the reeving, or components thereof, such as the monitoring/control unit and/or the system for detecting the presence of the secondary block, as described above, may be performed by way of the one or more computers.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19/13446 | Nov 2019 | FR | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2463394 | King | Mar 1949 | A |
| 3794185 | Kroll | Feb 1974 | A |
| 3993287 | Andersson | Nov 1976 | A |
| 6926103 | Roodenburg | Aug 2005 | B1 |
| Number | Date | Country |
|---|---|---|
| 109879181 | Jun 2019 | CN |
| 3061163 | Jun 2018 | FR |
| 397470 | Sep 1973 | SU |
| Entry |
|---|
| English translation of CN 109879181 A, 2022, Espacenet.com (Year: 2022). |
| English translation of FR 3061163 A1, 2022, Espacenet.com (Year: 2022). |
| FR search report and written opinion dated Aug. 4, 2020, issued in connection with corresponding FR Pat. Appl. No. 219/13446 (9 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20210188599 A1 | Jun 2021 | US |
