Lifting device with automatic reeving configuration change

Abstract

Lifting device (1) comprising a lower pulley (3) and an upper pulley (4), the lower pulley being suspended by a lifting cable (90) connected to a lifting winch (91), a reversible mechanical connection system to be reversibly configurable between a connected configuration and a disconnected configuration, which includes a locking element, a complementary locking element and an elastic return member urging said locking element to engage with said complementary locking element, a control / command unit (8) controlling the lifting winch and a sensor (81) for measuring a force on a strand of the lifting cable, and the control / command unit (8) controlling the lifting winch in a connection phase and in a disconnection phase according to the measurement data of the force on the strand of the lifting cable.

Description

[Technical field]

[0001] The invention relates to a lifting machine provided with a double-reeling lifting device, as well as to an associated method for changing the reeling configuration.

[0002] The invention finds a preferred, and non-limiting, application for a lifting machine such as a crane, and in particular a tower crane. [State of the art]

[0003] In a known manner, a double-haul lifting device is reversibly configurable between two hauling configurations including a single-haul configuration with two lifting strands and a double-haul configuration with four lifting strands, where the double-haul lifting device comprises a hauling changing system allowing a change of hauling configuration to be carried out between the single-haul configuration and the double-haul configuration.

[0004] Conventionally, such a double-haul lifting device comprises two blocks, namely a lower block secured to a lifting hook and an upper block, and these two blocks comprise reversible connection means to be reversibly configurable between two haul configurations: a connected configuration in which the upper block is connected to the lower block to be able to accompany it in raising / lowering movements, and a disconnected configuration in which the upper block is disconnected from the lower block to be able to remain suspended above the lower block which can perform lowering / raising movements without the upper block.

[0005] The lower block is suspended on the lifting device by a lifting cable connected to a lifting winch to raise / lower the lower block, and this lifting cable passes through the upper block, so that the connected configuration and the disconnected configuration correspond respectively to a double-reeling configuration and a single-reeling configuration, or vice versa, of the double-reeling lifting device, depending on the passage of the lifting cable at the upper block.

[0006] For example, documents FR 1 520 612, FR 2 137 333, FR 2 368 431, FR 2 131 924, FR 2 228 024 describe double-reeling lifting devices in which the connected configuration corresponds to the double-reeling configuration, and the disconnected configuration corresponds to the single-reeling configuration; the lifting cable passing below a pulley carried by the upper block.

[0007] And conversely, documents GB 2 176 456, FR 2 333 743, DE 3149 690, DE 35 43 214 describe double-reeling lifting devices in which the connected configuration corresponds to the single-reeling configuration, and the disconnected configuration corresponds to the double-reeling configuration; the lifting cable passing over a pulley carried by the upper block.

[0008] The state of the art can also be illustrated by the teachings of document FR3103803 which describes a lifting machine equipped with a double-reeling lifting device, and also comprising a control / command unit connected to a sensor for measuring a force on a strand of the lifting cable, where this control / command unit is configured or programmed to receive data measuring the force on the strand of the lifting cable in order to determine the weight of the load and compare it to a load curve and / or a maximum authorized load value.

[0009] However, automation of haulage changes (transition from the connected configuration to the disconnected configuration, and vice versa), although sought after, proves to be a safety issue that is currently poorly understood. [Summary of the invention]

[0010] The present invention aims to address this challenge of automating haulage changes, in order to secure both the connected configuration and the disconnected configuration.

[0011] To this end, the invention proposes a lifting machine, such as for example a crane, comprising a double-reeling lifting device comprising two blocks, namely a lower block secured to a lifting hook and an upper block, in which the lower block is suspended by a lifting cable connected to a lifting winch to raise / lower the lower block, said lifting cable passing through the upper block, in which the two blocks comprise a reversible mechanical connection system to be reversibly configurable between: a connected configuration in which the upper block is connected to the lower block to be able to accompany it in raising / lowering movements along a main axis, and a disconnected configuration in which the upper block is disconnected from the lower block to be able to remain suspended above the lower block which can perform lowering / raising movements without the upper block.

[0012] This reversible mechanical connection system comprises at least one locking element mounted on one of the two pulleys and a complementary locking element mounted on the other of the two pulleys, said locking element being shaped to be engaged with said complementary locking element in the connected configuration, an elastic return member urging said locking element to be engaged with said complementary locking element.

[0013] The lifting equipment also includes: a control / command unit controlling the lifting winch in order to raise / lower the lower block in order, in a connection phase, to engage the locking element with the complementary locking element and thus move into the connected configuration and in order, in a disconnection phase, to release the locking element from the complementary locking element and thus move into the disconnected configuration; a sensor for measuring a force on a strand of the lifting cable, and the control / command unit is connected to this sensor to receive data measuring the force on the strand of the lifting cable.

[0014] According to the invention, this control / command unit is configured or programmed to automatically control a change in the hauling configuration based on the measurement data of the force on the strand of the lifting cable, said control / command unit being configured or programmed to control the lifting winch in the connection phase and in the disconnection phase based on said measurement data of the force on the strand of the lifting cable.

[0015] In other words, the control / command unit will automatically control the changes in the hauling system (also called changes in hauling configuration) based on the data measuring the force on the strand of the lifting cable. In other words, the control / command unit allows, thanks to its configuration / programming, to automatically switch, without manual intervention, from the double hauling configuration to the single hauling configuration, and vice versa, reliably, quickly and repeatedly over time; this control / command unit controlling the raising / lowering movements of the lower block (by simply controlling the motorized system of the lifting winch) to switch from the disconnected configuration to the connected configuration, and vice versa, depending on the variations in the data measuring the force on the strand of the lifting cable.

[0016] Indeed, whether in the connection phase which involves engagement of the locking element with the complementary locking element or in the disconnection phase which involves release (or disengagement) of the locking element and the complementary locking element, the force on the strand of the lifting cable will vary, because the elastic return member will offer a resistive force during the transitions from “engaged” to “released”, and vice versa from “released” to “engaged”.

[0017] Thus, the invention proposes to monitor this force on the strand of the lifting cable to estimate the relative position between the locking element and the complementary locking element, and therefore the relative position between the two blocks, and consequently to control the lifting winch to move the lower block up or down.

[0018] According to one possibility, the control / command unit is shaped or programmed to control the lifting winch in the connection phase and in the disconnection phase depending on a variation in the force on the strand of the lifting cable.

[0019] In other words, when a connection phase or a disconnection phase is initiated, the control / command unit monitors the variations in the force on the strand of the lifting cable to estimate the relative position between the two blocks and thus adapt the up / down movements of the lower block.

[0020] In a particular embodiment, the control / command unit is configured or programmed to control the lifting winch in the connection phase or in the disconnection phase, in order to raise the lower block, until a predefined increase in the force on the strand of the lifting cable is detected.

[0021] Thus, by observing such an increase, the control / command unit estimates that a contact causes such an increase (depending on whether it is in the connection phase or the disconnection phase), thus making it possible to adapt the movement of the lower block.

[0022] Alternatively, the control / command unit is configured or programmed to, during the connection phase, control the lifting winch to raise the lower block, until it detects a predefined increase in the force on the strand of the lifting cable, called an increase during the connection phase.

[0023] Indeed, in the connection phase, the lower block rises alone until the locking element comes into contact with the complementary locking element then, the lower block continuing to rise, the locking element will come into engagement with the complementary locking element, with at the same time the elastic return member which will offer a resistive force, which results in an increase in the force on the strand of the lifting cable during the rise of the lower block and during engagement.

[0024] According to one characteristic, the increase in the connection phase of the force on the strand of the lifting cable is characterized by an excess of the force beyond a given connection force threshold, or by a slope of variation of the force above a given connection slope value.

[0025] Advantageously, which the control / command unit is configured or programmed to, in the connection phase, control the lifting winch in order to continue the raising of the lower block until a reduction in the force on the strand of the lifting cable is detected, after the predefined increase in the connection phase, and to stop the raising of the lower block in response to the detection of said reduction in the force on the strand of the lifting cable.

[0026] Indeed, when the locking element and the complementary locking element engage, the resistive force offered by the elastic return member is extinguished, which results in a reduction in the force on the strand of the lifting cable. Thus, detecting this reduction amounts to detecting this engagement, and therefore the lower block can be stopped in its ascent.

[0027] According to another characteristic, the control / command unit is configured or programmed to, in the connection phase and after having stopped the ascent of the lower block, control the lifting winch in order to lower the lower block.

[0028] In a particular embodiment, the control / command unit is configured or programmed to, in the disconnection phase, control the lifting winch in order to raise the lower block, until it detects a predefined increase in the force on the strand of the lifting cable, called an increase in the disconnection phase, to stop the raising of the lower block.

[0029] Indeed, in the disconnection phase, the lower block rises with the upper block until the upper block is at the top stop then, as the lower block continues to rise, the locking element will release its engagement with the complementary locking element, and at the same time the elastic return member will offer a resistive force, which results in an increase in the force on the strand of the lifting cable during the ascent of the lower block. Then, the locking element is released from the complementary locking element, which is detectable by an excess of the force beyond a certain threshold. Thus, detecting this increase in the force during the disconnection phase amounts to detecting this release, and therefore the lower block can be stopped in its ascent.

[0030] According to one characteristic, the increase in the disconnection phase of the force on the strand of the lifting cable is characterized by an excess of the force above a given disconnection force threshold.

[0031] According to another characteristic, the control / command unit is configured or programmed to, in the disconnection phase and after having stopped the ascent of the lower block, control the lifting winch in order to lower the lower block.

[0032] Advantageously, the sensor is a load sensor mounted on the lifting equipment to be able to measure the dead weight of the lower block.

[0033] In other words, this feature proposes to use a load sensor which is conventionally present on the crane, because it is used to determine the weight of the load suspended from the hook of the lower block; which is advantageous because it does not use a dedicated sensor, but rather a sensor already present.

[0034] In a particular embodiment, the load sensor is a gauge shaft mounted on a lifting cable return system.

[0035] In other words, the gauge axis is mounted on the return system on which the lifting cable is wound or unwound, the gauge axis measuring a torsional force from which the force exerted on the strand of the cable is deducted.

[0036] Advantageously, the gauge axis is an integral part of the equipment installed on the crane in order to measure the force exerted on the lifting cable and ensure the proper progress of lifting operations when the crane is working. It is not an additional monitoring device added to the crane solely to allow monitoring of a change of reeving.

[0037] In a particular embodiment, the locking element is a latch pivotally mounted on one of the two blocks to move within a locking channel, and the complementary locking element is a shaft mounted on the other of the two blocks.

[0038] The invention also relates to a method for changing the hauling configuration in a lifting machine described above, in which the control / command unit receives from the sensor data measuring the force on the strand of the lifting cable and automatically controls a change in hauling configuration based on the data measuring the force on the strand of the lifting cable, said control / command unit controlling the lifting winch in the connection phase and in the disconnection phase as a function of said data measuring the force on the strand of the lifting cable. [Brief description of the figures]

[0039] Other characteristics 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 in which: [ Fig 1 ] is a schematic view of a lifting crane according to the invention in a single-haul configuration; and [ Fig 2 ] is a schematic view of a part of the crane illustrating its double-reeling lifting device, in a suspended situation on a distribution trolley, in a disconnected configuration corresponding to the single-reeling configuration; [ Fig 3 ] is a schematic view of a lifting crane similar to that of the Figure 1 but in double hauling configuration; [ Fig 4 ] is a schematic view of a part of the lifting crane similar to that of the Figure 2, but with its double-haul lifting device in connected configuration corresponding to the double-haul configuration; [ Fig 5 ] is a partial schematic view of the double-reeling lifting device of the Figures 2 And 4 , in several stages of a connection phase (transition from the single hauling configuration to the double hauling configuration), with an illustration of the variation curve of a force on a strand of the lifting cable during this connection phase; [ Fig 6 ] is a partial schematic view of the double-reeling lifting device of the Figures 2 And 4 , in several stages of a disconnection phase (transition from the double hauling configuration to the single hauling configuration), with an illustration of the variation curve of a force on a strand of the lifting cable during this disconnection phase; [ Fig 7] is a schematic view of a control flowchart for the implementation of the connection phase by the crane control / command unit; [ Fig 8 ] is a schematic view of a control flowchart for the implementation of the disconnection phase by the crane control / command unit. [Detailed description of one or more embodiments of the invention]

[0040] In reference to the Figure 1 , a crane-type lifting device 1, according to an exemplary embodiment of the invention, comprises a boom 10 mounted on a mast 11, and a distributor carriage 9 mounted movably on the boom 10 and connected to a distribution system 13 capable of moving the distributor carriage 9 along the boom 10 in an opposite forward direction and a rearward direction; this distribution system 13 being for example a distribution winch 14 which cooperates with a distribution cable 15 for moving the distributor carriage 9.

[0041] The crane 1 comprises a double-reeling lifting device 2 which comprises two blocks 3, 4, namely: a lower block 3 secured to a lifting hook 30 provided for hanging a load, where the lower block 3 is suspended from the distributor trolley 9 (and therefore is suspended on the boom 10) by a lifting cable 90 connected to a lifting winch 91 to raise / lower the lower block 3; and an upper block 4 through which the lifting cable 90 passes, the upper block 4 also being suspended from the distributor trolley 9.

[0042] Also, the lower block 3 supports lower cable return means, such as for example two pulleys 31, for the passage of the lifting cable 90, and the upper block 4 supports upper cable return means, such as a pulley 41, for the passage of the lifting cable 90.

[0043] Thus, the double-reeling lifting device 2 is designed to lift / lower a load along the boom 10 of the crane 1.

[0044] The two pulley blocks 3, 4 are equipped with a reversible mechanical connection system to be reversibly configurable between two pulley configurations, which are: a connected configuration (illustrated on the Figures 3 and 4 ) in which the upper block 4 is connected to the lower block 3 to be able to accompany it in up / down movements along a main axis which is of vertical extension, and a disconnected configuration (illustrated on the Figures 1 and 2 ) in which the upper block 4 is disconnected from the lower block 3 so that it can remain suspended above the lower block 3 which can perform lowering / raising movements alone without the upper block 4.

[0045] Depending on the passage of the lifting cable 90 in the lower cable return means 31 provided on the lower block 3 and in the upper cable return means 41 provided on the upper block 4, the connected configuration and the disconnected configuration correspond respectively to a double hauling configuration and to a single hauling configuration, or vice versa, of the double hauling lifting device 2; the single hauling configuration being associated with support of the hook 30 (and therefore of the load) by two lifting strands of the lifting cable 90, and the double hauling configuration being associated with support of the hook 30 (and therefore of the load) by four lifting strands of the lifting cable 90.

[0046] In the illustrated example, the connected configuration of the Figures 3 and 4 corresponds to the double pulley configuration (four strands), so that the disconnected configuration of the Figures 1 and 2corresponds to the single pulley configuration (two strands).

[0047] The reversible mechanical connection system comprises a locking mechanism 5 mounted on the lower block 3, and a complementary locking structure 6 mounted on the upper block 4 and capable of cooperating with the locking mechanism 5.

[0048] The locking mechanism 5 is integrated into the lower block 3 and is provided above the lower cable return means, therefore above the two pulleys 31 in the example illustrated. This locking mechanism 5 comprises: a chassis 50 comprising two facing plates which delimit between them an interstitial space; and a latch 52 pivotally mounted on the chassis 50, between these two plates, where the latch 52 is associated with a pushing device 7 described later.

[0049] The complementary locking structure 6 is part of the upper block 4 and is provided below the upper cable return means, therefore below the pulley 41 in the example illustrated. This complementary locking structure 6 comprises: a frame 60 comprising two facing flanges which delimit between them a groove open on the underside of the upper block 4 to define an entrance; and a locking member 62 supported integrally by the frame, where this locking member 62 forms a shaft extending along a longitudinal axis orthogonal to the main axis, and where this locking member 62 extends between the two flanges of the frame 60 at a given distance from the entrance of the groove.

[0050] The chassis 50 has a locking channel 53 of elongated shape along the main axis (therefore in a vertical direction), where this locking channel 53 is formed by two notches arranged opposite each other in the two plates of the chassis 50 and opening onto upper edges of these plates, so that this locking channel 53 is provided with a mouth through which the locking member 62 of the complementary locking structure 6 can enter and exit the locking channel 53. The mouth is flared to facilitate and center the insertion of the locking member 62 inside the locking channel 53.

[0051] The latch 52 is provided with a free end of concave shape suitable for being engaged with the locking member 62, where the free end has a notch of complementary shape to the locking member 62. The latch 52 thus forms a locking element and the locking member 62 forms a complementary locking element, where the latch 52 is shaped to be engaged with said locking member 62 in the connected configuration.

[0052] The thrust device 7 extends between the two plates of the chassis 50 and it comprises a thrust stop 70 provided with a free front end suitable for coming into abutment against the latch 52, and more specifically against a bearing surface provided close to the pivot axis. This thrust stop 70 also has a free rear end, opposite the free front end. The thrust stop 70 is in the form of an elongated part along an extension axis orthogonal to the main axis.

[0053] The thrust stop 70 is mounted to move in translation on the chassis 50, in a translation direction orthogonal to the main axis. The thrust stop 70 is sliding between: a maximum advanced position (visible on the Figure 5 step (1) and the Figure 6 steps (3), (4) and (6)) in the absence of thrust exerted by the latch 52 on its free front end, and the recoil positions (visible on the Figure 5steps (2) to (5) and the Figure 6 steps (1) and (2)) in the presence of a thrust force exerted by the latch 52 on its free front end.

[0054] The thrust stop 70 passes through and slides in a fixed support 73 secured to the chassis 50, so that the free front end and the free rear end are arranged on either side of the fixed support 73.

[0055] The thrust device 7 further comprises an elastic return member 74, for example in the form of a helical spring, this elastic return member 74 urging the thrust stop 70 towards its maximum forward position and offering a force resisting a thrust force exerted by the latch 52 on its free front end. Thus, the elastic return member 74 is at rest in the maximum forward position of the thrust stop 70.

[0056] In the example illustrated, this elastic return member 74 is interposed between the fixed support 73 and the free front end, and more precisely a stop surface provided on the free front end. Thus, when the latch 52 exerts a thrust force on the free front end, causing the thrust stop 70 to move back, then the elastic return member 74 compresses and thus opposes this movement back. This elastic return member 74 therefore urges the latch 52 to be engaged with the locking member 62.

[0057] According to the invention, the crane 1 further comprises a control / command unit 8 (for example of the type comprising at least one electronic card, a processor and / or a microcontroller) controlling the lifting winch 91 in order to raise / lower the lower block 3 in order, in a connection phase, to engage the latch 52 with the locking member 62 and thus pass into the connected configuration and in order, in a disconnection phase, to release the latch 52 from the locking member 62 and thus pass into the disconnected configuration.

[0058] The crane 1 further comprises a sensor 81 for measuring a force F1 on a strand of the lifting cable 90. This sensor 81 may be a load sensor mounted on the crane 1 to be able to measure a self-weight of the lower block 3, such as a gauge axis mounted on a return system of the lifting cable 90.

[0059] Thus, the control / command unit 8 is connected to this sensor 81 to receive measurement data of the force F1 on the strand of the lifting cable 90 and this control / command unit 8 is configured or programmed to control the lifting winch 91 in the connection phase and in the disconnection phase as a function of these measurement data of the force F1 on the strand of the lifting cable 90.

[0060] In this way, the control / command unit 8 automatically controls the changes in the hauling system based on the measurement data of the force F1 on the strand of the lifting cable 90, this control / command unit 8 controlling the raising / lowering movements of the lower block 3 (by controlling the lifting winch 91) to switch from the disconnected configuration to the connected configuration, and vice versa, depending on the variations in the measurement data of the force F1 on the strand of the lifting cable 90.

[0061] Indeed, in the connection phase and in the disconnection phase, only the control of the raising / lowering movements of the lower block 3 makes it possible to switch from a connected configuration to the disconnected configuration, and vice versa. The control of the raising / lowering movements of the lower block 3 is carried out by controlling the lifting winch 91.

[0062] Also, the control / command unit 8 makes it possible to automate the movements of the lower block 3, in the connection phase and in the disconnection phase, based on the measurement data of the force F1.

[0063] The following description concerns the connection phase for the transition from the disconnected configuration to the connected configuration, with reference to the Figure 5, with several successive steps numbered from (1) to (5) illustrating the two pulley blocks 3, 4, and with a curve C1 illustrating the variation of the measurement of the force F1 (expressed in daN) on the strand of the lifting cable 90 as a function of time at the different steps (1) to (5) illustrated above the curve C1.

[0064] In reference to the Figure 5 step (1), in the disconnected configuration, the upper block 4 is suspended above the lower block 3 and the latch 52 is in the neutral position, with the thrust stop 70 in the maximum advanced position. To move from the disconnected configuration to the connected configuration, the lower block 3 begins by being raised, as shown diagrammatically by the arrow MO, for a relative rapprochement between the two blocks 3, 4, until, with reference to the Figure 5step (2), the locking member 62 enters the locking channel 53 through the mouth and comes into contact with a proximal edge of the latch 52, thus bringing the upper block 4 to the upper stop on the boom, and more specifically until an upper stop of the upper block 4 is in abutment against the distributor carriage 9.

[0065] In reference to the Figure 5steps (3) and (4), while continuing the rise of the lower block 3, the locking member 62 exerts a thrust on the proximal edge of the latch 52, while sliding inside the locking channel 53 in the entry direction (downwards), to bring the latch 52 into a distal position in which the locking member 62 bears on a proximal tip of the latch 52 (see step (3)), then the locking member 62 exceeds this proximal tip of the latch 52 and then the locking member 62 leaves contact with this proximal tip (see step (4)), and thus the latch 52 pivots in a proximal direction of rotation (upwards) under the effect of a thrust exerted by the pushing device 7, until a distal edge of the latch 52 in turn comes into contact with the locking member 62, as shown diagrammatically at step (4).

[0066] Thus, and as visible in step (4), the locking member 62 is engaged inside the free end of the latch 52.

[0067] In reference to the Figure 5 step (5), the lower pulley block 3 is then moved downwards, as shown diagrammatically by the arrow DE, so that the locking member 62 slides inside the locking channel 53 in the exit direction (upwards), and brings the latch 52 into the locking position, until the locking member 62 is wedged inside the free end of the latch 52 and is therefore blocked in sliding in the locking channel 53 in the exit direction, and thus the lower pulley block 3 and the upper pulley block 4 are connected.

[0068] In other words, in the connected configuration, the latch 52 is in the locking position and the locking member 62 is stuck inside the free end of the latch 52, more precisely the locking member 62 stuck inside the notch of this free end.

[0069] In this connected configuration, the lower block 3 can be lowered together with the upper block 4. Indeed, when the lower block 3 descends with its latch 52, this latch 52 is blocked by the locking member 62 and cannot pivot in the proximal direction of rotation (pivoting upwards). Thus, the latch 52 remains blocked in the locking position with the locking member 62 which, as a reminder, is integral with the upper block 4. The upper block 4 is therefore connected to the lower block 3 and therefore descends with it.

[0070] As can be seen on the C1 curve of the Figure 5, during step (1), the force F1 is constant in the absence of contact between the locking member 62 and the latch 52. During steps (3) and (4), the force F1 increases as long as the locking member 62 exerts a thrust on the latch 52. Then the force F1 decreases during step (4) when the locking member 62 has passed the proximal tip of the latch 52 and the latch 52 pivots under the effect of a thrust exerted by the thrust device 7. Finally, during step (5), the force F1 increases again during the descent of the lower block 3 secured to the upper block 4.

[0071] During steps (1) to (5) of the connection phase, the control / command unit 8 controls the lifting winch 91 in order to: raising the lower block 3, until detecting a predefined increase in the force F1 (called increase in the connection phase), associated with steps (2) and (3); in fact, thanks to this measurement of an increase in the force F1, the control / command unit 8 deduces that the connection phase is initiated and that the locking member 62 and the latch 52 begin to cooperate together; then continuing the raising of the lower block until detecting a decrease in the force F1 (step (4)), after the predefined increase, and stopping the raising of the lower block 3 in response to the detection of said decrease in the force F1; and finally, after stopping the raising of the lower block 3, lowering the lower block 3 (step (5)) which is now connected to the upper block 4.

[0072] It should be noted that the increase in the connection phase of the force F1 during steps (3) and (4) can be characterized by an excess of the force F1 beyond a given connection force threshold, or by a variation slope of the force F1 (slope measured on the curve C1 in steps (2) and (3)) above a given connection slope value.

[0073] It should also be noted that the control / command unit 8 can raise the lower muffle 3 until it detects: the reduction of the force F1 (which reflects step (4)), for example by detecting a negative derivative of the force F1; or the passage of the force F1 beyond the given connection force threshold.

[0074] There Figure 7 schematizes the phases implemented by the control / command unit 8 during the connection phase: “start connection” step initiated by an operator on a dedicated interface; “lifting up” step to control the lifting winch in ascent, for example at a minimum ascent speed; “end of ascent detection” step which corresponds to the detection of the end of the ascent of the lower block 3 on the basis of the measurements of the force F1, such as for example the detection of the reduction of the force F1 or the passage of the force F1 beyond the connection force threshold; “stop lifting” step to control the stopping of the lifting winch; “lifting down” step to control the lifting winch in descent, for example at the minimum descent speed; “validation” step initiated by an operator to validate that the connection phase is finished.

[0075] The following description concerns the disconnection phase for the transition from the connected configuration to the disconnected configuration, with reference to the Figure 6, with several successive steps numbered from (1) to (6) illustrating the two pulley blocks 3, 4, and with a curve C2 illustrating the variation of the measurement of the force F1 (expressed in daN) on the strand of the lifting cable 90 as a function of time at the different steps (1) to (6) illustrated above the curve C2.

[0076] In reference to the Figure 6 step (1), to move from the connected configuration to the disconnected configuration, the lower pulley block 3 is first mounted (with the upper pulley block 4), as shown diagrammatically by the arrow MO, until the upper pulley block 4 is at the top stop on the arrow, and more specifically until the upper stop of the upper pulley block 4 is at the top stop against the distributor carriage.

[0077] Once the upper block 4 is at the upper stop, the lower block 3 continues to rise, as shown by the arrow MO, while the upper block 4 is blocked. Thus, as the locking channel 53 rises, the locking member 62 slides inside this locking channel 53 in the direction of entry (downward), it being noted that the latch 52 will not oppose this sliding and that the latch 52 will thus pivot in the distal direction of rotation (downward) under the effect of a thrust exerted by the locking member 62 on a distal edge of the latch 52. Also, the latch 52 pivots downward, while the locking member 62 slides towards the bottom 55 of the locking channel 53, until the locking member 62 leaves the interior of the free end of the latch 52, passes its distal tip and finally leaves contact with the latch 52, and then, as illustrated in Figure 6steps (2) and (3), the latch 52 returns to the neutral position under the effect of the thrust exerted by the thrust device 7, and the locking member 62 is under the latch 52 (or even is arranged in the bottom 55 of the locking channel 53).

[0078] During this step (4), the thrust stop 70 moves back under the effect of the pivoting of the latch 52 when the locking member 62 is resting on the distal tip of the latch 52, then the thrust stop 70 moves forward to return the latch 52 to the neutral position under the effect of the elastic return member 74.

[0079] In reference to the Figure 6steps (4) and (5), the lower block 3 is moved downwards, as shown diagrammatically by the arrow DE, so that the locking member 62 slides inside the locking channel 53 in the exit direction (upwards), until it comes to bear against the distal edge of the latch 52, thus pushing the latch 52 which then pivots in the proximal rotation direction (upwards), thus allowing the locking member 62 to exit the locking channel 53 and to disengage from the latch 52. During these steps (4) and (5), the thrust stop 70 remains at all times in its maximum advanced position, the latch 52 leaving contact with its free front end by pivoting towards the proximal position.

[0080] Thus, and as illustrated on the Figure 6step (6), the locking member 62 is completely disengaged from the lower block 3 and the latch 52 has returned to the neutral position under the effect of a possible proximal stop 79 mounted on the frame 50 and its own weight, and thus the lower block 3 and the upper block 4 are disconnected, which makes it possible to continue the descent of the lower block 3 alone in the disconnected configuration, without the upper block 4 which remains at the level of the distributor carriage 9.

[0081] As can be seen on the C2 curve of the Figure 6, during step (1), the force F1 increases until the upper pulley block 4 is in abutment against the dispensing carriage and as long as the locking member 62 is in contact with the latch 52 and exerts a thrust on this latch 52. Then the force F1 decreases to reach a zero value during steps (2) and (3), due to the loss of contact between the locking member 62 and the latch 52. During steps (4) and (5), the force F1 increases again during the descent of the lower pulley block 3 which separates from the upper pulley block 4.

[0082] During steps (1) to (5) of the disconnection phase, the control / command unit 8 controls the lifting winch 91 in order to: raising the lower block 3, until detecting an increase (step (1)) of the force F1 (called increase in the disconnection phase) such that said force F1 reaches a given disconnection force threshold to stop the raising of the lower block 3; in fact, thanks to this measurement of an increase in the disconnection phase of the force F1 beyond the disconnection force threshold, the control / command unit 8 deduces that the disconnection phase is initiated and that the locking member 62 and the latch 52 have disconnected and are at the stage of step (3); and finally, after having stopped the raising of the lower block 3, lowering the lower block 3 (steps (4) to (6)) which disconnects from the upper block 4.

[0083] There Figure 8 schematizes the phases implemented by the control / command unit 8 during the disconnection phase: “start disconnection” step initiated by an operator on a dedicated interface; “lifting up” step to control the lifting winch in ascent, for example at a minimum ascent speed; “end of ascent detection” step which corresponds to the detection of the end of the ascent of the lower block 3 on the basis of the measurements of the force F1, such as for example the detection of the passage of the force F1 beyond the disconnection force threshold; “stop lifting” step to control the stopping of the lifting winch; “lifting down” step to control the lifting winch in descent, for example at the minimum descent speed; “validation” step initiated by an operator to validate that the disconnection phase is finished.

[0084] Furthermore, it is possible to reverse the positions of the locking mechanism 5 and the complementary locking structure 6 of the reversible mechanical connection system, by providing the locking mechanism 5 on the upper pulley 4 and by providing the complementary locking structure 6 on the lower pulley 3. It is also possible to operate with a single latch 52 for the locking mechanism 5, by adapting the shape of the latch 52 to wedge the locking member 62 in the locking channel 53.

[0085] Alternatively, it is possible to operate with two or more latches 52 for the locking mechanism 5. It is also conceivable to provide one or more elastic return members other than the spring described above, such as for example an elastic blade, a return mechanism, or other equivalent elastic constraint means.

Claims

1. A lifting machinery (1), like for example a crane, comprising a double-reeved lifting device (2) comprising two reeve blocks (3, 4), namely a lower reeve block (3) secured to a lifting hook (30) and an upper reeve block (4), wherein the lower reeve block (3) is hanging by a lifting rope (90) connected to a lifting winch (91) to make the lower reeve block (3) rise / descend, said lifting rope (90) passing through the upper reeve block (4), wherein the two reeve blocks (3, 4) comprise a reversible connection mechanical system (5, 6) to be reversibly configurable between two reeving configurations: - a connected configuration in which the upper reeve block (4) is connected to the lower reeve block (3) so as to be able to accompany it in rise / descent movements according to a main axis, and - a disconnected configuration in which the upper reeve block (4) is disconnected from the lower reeve block (3) so as to be able to remain hanging above the lower reeve block (3) which could perform descent / rise movements without the upper reeve block (4), wherein the reversible connection mechanical system (5, 6) comprises at least one locking element (52) mounted on one of the two reeve blocks (3, 4) and a locking complementary element (62) mounted on the other one of the two reeve blocks (3, 4), said locking element (52) being shaped so as to be engaged with said locking complementary element (62) in the connected configuration, an elastic return member (74) urging said locking element (52) to engage with said locking complementary element (62), said lifting machinery (1) further comprising : - a control / command unit (8) piloting the lifting winch (91) in order to make the lower reeve block (3) rise / descend so as to engage, in a connection phase, the locking element (52) with the locking complementary element (62) and thus switch into the connected configuration and so as to release, in a disconnection phase, the locking element (52) from the locking complementary element (62) and thus switch into the disconnected configuration, - a sensor (81) to measure a force (F1) on a strand of the lifting rope (90), and the control / command unit (8) is connected to said sensor (81) to receive measurement data of the force (F1) on the strand of the lifting rope (90); said lifting machinery (1) being characterized in that the control / command unit (8) is configured or programmed to automatically monitor a reeving configuration change based on the measurement data of the force (F1) on the strand of the lifting rope (90), said control / command unit (8) being configured or programmed to pilot the lifting winch (91) in the connection phase and in the disconnection phase according to said measurement data of the force (F1) on the strand of the lifting rope (90).

2. The lifting machinery (1) according to claim 1, wherein the control / command unit (8) is configured or programmed to pilot the lifting winch (91) in the connection phase and in the disconnection phase according to a variation of the force (F1) on the strand of the lifting rope (90).

3. The lifting machinery (1) according to claim 2, wherein the control / command unit (8) is configured or programmed to pilot the lifting winch (91) in the connection phase or in the disconnection phase, in order to raise the lower reeve block (3), until detecting a predefined increase in the force (F1) on the strand of the lifting rope (90).

4. The lifting machinery (1) according to any one of claims 1 to 3, wherein the control / command unit (8) is configured or programmed, in the connection phase, to pilot the lifting winch (91) in order to make the lower reeve block (3) rise until detecting a predefined increase in the force (F1) on the strand of the lifting rope (90), called increase in connection phase.

5. The lifting machinery (1) according to claim 4, wherein the increase in connection phase of the force (F1) on the strand of the lifting rope (90) is characterized by a passage of the force (F1) beyond a given connection force threshold, or by a variation slope of the force (F1) above a given connection slope value.

6. The lifting machinery (1) according to claim 4 or 5, wherein the control / command unit (8) is configured or programmed, in the connection phase, to pilot the lifting winch (91) in order to carry on the rise of the lower reeve block (3) until detecting a decrease in the force (F1) on the strand of the lifting rope (90), after the predefined increase in connection phase, and to stop the rise of the lower reeve block (3) in response to the detection of said decrease in the force (F1) on the strand of the lifting rope (90).

7. The lifting machinery (1) according to claim 6, wherein the control / command unit (8) is configured or programmed, in the connection phase and after having stopped the rise of the lower reeve block (3), to pilot the lifting winch (91) in order to make the lower reeve block (3) descend.

8. The lifting machinery (1) according to any one of claims 1 to 3, wherein the control / command unit (8) is configured or programmed, in the disconnection phase, to pilot the lifting winch (91) in order to make the lower reeve block (3) rise, until detecting a predefined increase in the force (F1) on the strand of the lifting rope (90), called increase in disconnection phase, to stop the rise of the lower reeve block (3).

9. The lifting machinery (1) according to claim 8, wherein the increase in disconnection phase of the force (F1) on the strand of the lifting rope (90) is characterized by a passage of the force (F1) beyond a given disconnection force threshold.

10. The lifting machinery (1) according to claim 8 or 9, wherein the control / command unit (8) is configured or programmed, in the disconnection phase and after having stopped the rise of the lower reeve block (3), to pilot the lifting winch (91) in order to make the lower reeve block (3) descend.

11. The lifting machinery (1) according to any one of the preceding claims, wherein the sensor (81) is a load sensor mounted on the lifting machinery (1) so as to be able to measure a weight specific to the lower reeve block (3).

12. The lifting machinery (1) according to claim 11, wherein the load sensor is a load pin mounted on a system for deflecting the lifting rope (90).

13. The lifting machinery (1) according to any one of the preceding claims, wherein the locking element (52) is a pawl pivotally mounted on one of the two reeve blocks (3, 4) so as to be movable within a locking channel (53), and the locking complementary element (62) is a shaft mounted on the other one of the two reeve blocks (3, 4).

14. A reeving configuration change method in a lifting machinery (1) according to any one of the preceding claims, wherein the control / command unit (8) receives from the sensor (81) measurement data of the force (F1) on the stand of the lifting rope (90) and automatically monitor a reeving configuration change based on the measurement data of the force (F1) on the strand of the lifting rope (90), said control / command unit piloting the lifting winch (91) in the connection phase and in the disconnection phase according to said measurement data of the force (F1) on the strand of the lifting rope (90).

Images