Lifting device with automated pulley system change

Abstract

A lifting device (1) comprising a lower pulley block (3) and an upper pulley block (4), the lower pulley block being suspended by a lifting cable (90) connected to a lifting winch (91), a reversible mechanical connection system configurable between a connected and a disconnected configuration, comprising a locking element, a supplementary locking element, and an elastic return element engaging said locking element with said supplementary locking element, a control unit (8) controlling the lifting winch and a sensor (81) for measuring a force on a strand of the lifting cable, and the control unit (8) controlling the lifting winch in a connection phase and in a disconnection phase according to the measured force on the strand of the lifting cable. Figure 1

Description

Title of the invention: Lifting device with automated reeving change Technical field

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

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

[0003] In a known manner, a double-haul lifting device is reversibly configurable between two haul 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 haul changing system allowing a haul change to be made between the single haul configuration and the double haul configuration.

[0004] Conventionally, such a double-reeling 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:

[0005] - a connected configuration in which the upper muffle is connected to the lower mitten to be able to accompany it in up / down movements, and

[0006] - a disconnected configuration in which the upper muffle is disconnected of the lower block to be able to remain suspended above the lower block which can perform lowering / raising movements without the upper block.

[0007] 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-reel configuration and a single-reel configuration, or vice versa, of the double-reel lifting device, depending on the passage of the lifting cable at the upper block.

[0008] 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-haul lifting devices in which the connected configuration corresponds to the double-haul configuration, and the disconnected configuration corresponds to the single-haul configuration; the cable of lifting passing below a pulley carried by the upper block.

[0009] And conversely, documents GB 2 176 456, FR 2 333 743, DE 31 49 690, DE 35 43 214 describe double-haul lifting devices in which the connected configuration corresponds to the single-haul configuration, and the disconnected configuration corresponds to the double-haul configuration; the lifting cable passing above a pulley carried by the upper block.

[0010] However, automation of hauling 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 controlled. Summary of the invention

[0011] The present invention aims to respond to this challenge of automating the changes of hauling, in order to secure both the connected configuration and the disconnected configuration.

[0012] 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 pulley is connected to the lower pulley to be able to accompany it in up / down movements along a main axis, and - a disconnected configuration in which the upper block is disconnected from the lower block so that it can remain suspended above the lower block which can perform lowering / raising movements without the upper block.

[0013] 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.

[0014] The lifting machine further comprises 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, release the locking element from the complementary locking element and thus move into the disconnected configuration.

[0015] According to the invention, this lifting machine is remarkable in that it comprises 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 and to control 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.

[0016] In other words, the control / command unit will automatically control the changes in the hauling system based on the data measuring the force on the strand of the lifting cable. In other words, the control / command unit makes it possible 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.

[0017] 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 conversely from “released” to “engaged”.

[0018] 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 pulley blocks, and consequently to control the lifting winch to move the lower pulley block up or down.

[0019] According to one possibility, the control / command unit is configured to control the lifting winch in the connection phase and in the disconnection phase as a function of a variation in the force on the strand of the lifting cable.

[0020] According to another possibility, the control / command unit is configured to, in the connection phase, control the lifting winch in order to raise the lower block, until a predefined increase in the force on the strand of the lifting cable is detected.

[0021] 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 engage 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.

[0022] According to one characteristic, the increase in 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.

[0023] Advantageously, which the control / command unit is configured 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, 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.

[0024] 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.

[0025] According to another characteristic, the control / command unit is designed to, in the connection phase and after having stopped the rise of the lower block, control the lifting winch in order to lower the lower block.

[0026] In a particular embodiment, the control / command unit is configured 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 to stop the raising of the lower block.

[0027] Indeed, in the disconnection phase, the lower block rises with the upper block until the upper block is at the top stop then, the lower block continuing 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 rise 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 force amounts to detecting this release, and therefore the lower block can be stopped in its rise.

[0028] According to one characteristic, the predefined increase in the force on the strand of the lifting cable is characterized by an excess of the force above a force threshold of given disconnection.

[0029] According to another characteristic, the control / command unit is designed to, in the disconnection phase and after having stopped the rise of the lower block, control the lifting winch in order to lower the lower block.

[0030] Advantageously, the sensor is a load sensor mounted on the lifting device to be able to measure the dead weight of the lower block.

[0031] 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 require a dedicated sensor, but rather a sensor already present.

[0032] In a particular embodiment, the load sensor is a gauge shaft mounted on a lifting cable return system.

[0033] 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.

[0034] 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 that lifting operations are carried out correctly when the crane is working. It is not an additional monitoring device added to the crane solely to enable monitoring of a change of haulage.

[0035] 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.

[0036] The invention also relates to a method for changing the hauling system in a lifting machine according to the invention, in which the control / command unit receives from the sensor data measuring the force on the strand of the lifting cable and controls 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 drawings

[0037] 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:

[0038] [Fig-1] is a schematic view of a lifting crane according to the invention in simple reeving configuration; And

[0039] [Fig.2] is a schematic view of part of the crane illustrating its double-reeving lifting device, in a suspended situation on a distribution trolley, in a disconnected configuration corresponding to the simple hauling configuration;

[0040] [Fig.3] is a schematic view of a lifting crane similar to that of [Fig.l] but in a double-reeving configuration;

[0041] [Fig.4] is a schematic view of a portion of the lifting crane similar to that of [Fig.2], but with its double-reeling lifting device in a connected configuration corresponding to the double-reeling configuration;

[0042] [Fig.5] is a partial schematic view of the double-haul lifting device of Figures 2 and 4, in several stages of a connection phase (transition from the single-haul configuration to the double-haul configuration), with an illustration of the variation curve of a force on a strand of the lifting cable during this connection phase;

[0043] [Fig.6] is a partial schematic view of the double hauling lifting device of 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;

[0044] [Fig.7] is a schematic view of a control flowchart for implementing the connection phase by the crane control / command unit;

[0045] [Fig.8] is a schematic view of a control flowchart for the implementation of the disconnection phase by the crane control / command unit.

[0046] [Detailed description of one or more embodiments of the invention]

[0047] With reference to [Fig.l], a crane type lifting device 1, according to an example of a sheave lisation 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.

[0048] The crane 1 comprises a double-reeling lifting device 2 which comprises two blocks 3, 4, namely:

[0049] - 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

[0050] - an upper pulley 4 through which the lifting cable 90 passes, the upper pulley upper 4 also being suspended from the distributor trolley 9.

[0051] 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.

[0052] Thus, the double-reeving lifting device 2 is configured to lift / lower a load along the boom 10 of the crane 1.

[0053] The two muffles 3, 4 are equipped with a reversible mechanical connection system to be reversibly configurable between:

[0054] - a connected configuration (illustrated in Figures 3 and 4) in which the mitten upper 4 is connected to the lower pulley 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 in 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.

[0055] 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.

[0056] In the illustrated example, the connected configuration of Figures 3 and 4 corresponds to the double hauling configuration (four strands), so that the disconnected configuration of Figures 1 and 2 corresponds to the single hauling configuration (two strands).

[0057] 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.

[0058] 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:

[0059] - a chassis 50 comprising two facing plates which delimit between them a interstitial space; and

[0060] - 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.

[0061] 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:

[0062] - 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

[0063] - a locking member 62 supported integrally by the frame, where this locking member 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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 in [Fig.5] step (1) and [Fig.6] steps (3), (4) and (6)) in the absence of thrust exerted by the latch 52 on its free front end, and - recoil positions (visible in [Fig.5] steps (2) to (5) and [Fig.6] steps (1) and (2)) in the presence of a thrust force exerted by the latch 52 on its free front end.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] Thus, the control / command unit 8 is connected to this sensor 81 to receive data measuring the force F1 on the strand of the lifting cable 90 and to control the lifting winch 91 in the connection phase and in the disconnection phase as a function of these data measuring the force F1 on the strand of the lifting cable 90.

[0074] 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 conversely, depending on the variations in the measurement data of the force Fl on the strand of the lifting cable 90.

[0075] 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.

[0076] 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 Fl.

[0077] The remainder of the description relates to the connection phase for the transition from the disconnected configuration to the connected configuration, with reference to [Fig. 5], with several successive steps numbered from (1) to (5) illustrating the two pulley blocks 3, 4, and with a curve Cl illustrating the variation in the measurement of the force Fl (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 CL

[0078] With reference to [Fig. 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 approach between the two blocks 3, 4, until, with reference to [Fig. 5] step (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 into high abutment on the arrow, and more specifically until an upper stop of the upper block 4 is in abutment against the distributor carriage 9.

[0079] With reference to [Fig. 5] steps (3) and (4), by 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 to the contact of the locking member 62, as shown diagrammatically in step (4). Thus, and as visible in step (4), the locking member rust 62 is engaged inside the free end of the latch 52.

[0080] With reference to [Fig.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.

[0081] 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.

[0082] 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.

[0083] As can be seen on the curve Cl of [Fig. 5], during step (1), the force Fl is constant in the absence of contact between the locking member 62 and the latch 52. During steps (3) and (4), the force Fl increases as long as the locking member 62 exerts a thrust on the latch 52. Then the force Fl 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 Fl increases again during the descent of the lower block 3 secured to the upper block 4.

[0084] During steps (1) to (5) of the connection phase, the control / command unit 8 controls the lifting winch 91 in order to: - raise the lower block 3, until a predefined increase in the force F1 is detected, 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 continue the raising of the lower block until a decrease in the force Fl is detected (step (4)), after the predefined increase, and stop the raising of the lower block 3 in response to the detection of said decrease in the force Fl; and - finally, after stopping the rise of the lower pulley 3, lower the lower muffle 3 (step (5)) which is now connected to upper muffle 4.

[0085] It should be noted that the increase in force F1 during steps (3) and (4) can be characterized by an excess of force F1 beyond a given connection force threshold, or by a variation slope of force F1 (slope measured on curve C1 in steps (2) and (3)) above a given connection slope value.

[0086] 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 Fl (which reflects step (4)), for example by detecting a negative derivative of the force Fl; or - the passage of the force Fl beyond the given connection force threshold.

[0087] [Fig.7] shows schematically the phases implemented by the control / command unit 8 during the connection phase: - “connection start” step initiated by an operator on a dedicated interface; - “lifting up” step to control the lifting winch uphill, 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 Fl, such as for example the detection of the reduction of the force Fl or the passage of the force Fl beyond the connection force threshold; - “lifting stop” step to control the stopping of the lifting winch; - “lifting descent” 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 complete.

[0088] The remainder of the description relates to the disconnection phase for the transition from the connected configuration to the disconnected configuration, with reference to [Fig.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 in the measurement of the force Fl (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.

[0089] With reference to [Fig.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.

[0090] Once the upper block 4 is at the top 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 (downwards), 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 (downwards) 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 downwards, 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, exceeds its distal tip and finally leaves contact with the latch 52, and then, as illustrated in [Fig. 6] steps (2) and (3), the latch 52 returns to the neutral position under the effect of the thrust exerted by the pushing device 7, and the member locking channel 62 is under the latch 52 (or even is arranged in the bottom 55 of the locking channel 53). 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.

[0091] With reference to [Fig. 6] steps (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.

[0092] Thus, and as illustrated in [Fig.6] step (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.

[0093] As can be seen on curve C2 of [Fig.6], during step (1), the force F1 increases until the upper pulley block 4 is in abutment against the distributor 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 pulley block superior 4.

[0094] During steps (1) to (5) of the disconnection phase, the control / command unit 8 controls the lifting winch 91 in order to: - raise the lower block 3, until detecting an increase (step (1)) in the force Fl such that said force Fl 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 force Fl 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, lower the lower block 3 (steps (4) to (6)) which disconnects from the upper block 4.

[0095] [Fig.8] shows schematically the phases implemented by the control / command unit 8 during the disconnection phase: - “departure disconnection” step initiated by an operator on a dedicated interface; - “lifting up” step to control the lifting winch uphill, 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 Fl, such as for example the detection of the passage of the force Fl beyond the disconnection force threshold; - “lifting stop” step to control the stopping of the lifting winch; - “lifting descent” 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 complete.

[0096] 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 block 4 and by providing the complementary locking structure 6 on the lower pulley block 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. Alternatively, it is possible to operate with two or more latches 52 for the locking mechanism 5. It is also possible to provide one or more elastic return members other than the spring previously described, such as for example an elastic blade, a return mechanism, or other equivalent elastic constraint means.

Claims

1. Claims Lifting machine (1), such as for example a crane, comprising a double-reeling lifting device (2) comprising two blocks (3, 4), namely a lower block (3) secured to a lifting hook (30) and an upper block (4), in which the lower block (3) is suspended by a lifting cable (90) connected to a lifting winch (91) for raising / lowering the lower block (3), said lifting cable (90) passing through the upper block (4), in which the two blocks (3, 4) comprise a reversible mechanical connection system (5, 6) to be reversibly configurable between: - a connected configuration in which the upper block (4) is connected to the lower block (3) to be able to accompany it in raising / lowering movements along a main axis, and - a disconnected configuration in which the upper block (4) is disconnected from the lower block (3) to be able to remain suspended above the lower block (3) which can carry out lowering / raising movements without the upper block (4), in which the reversible mechanical connection system (5, 6) comprises at least one locking element (52) mounted on one of the two blocks (3, 4) and a complementary locking element (62) mounted on the other of the two blocks (3, 4), said locking element (52) being shaped to be engaged with said complementary locking element (62) in the connected configuration,an elastic return member (74) urging said locking element (52) to be engaged with said complementary locking element (62), said lifting machine (1) further comprising a control / command unit (8) controlling the lifting winch (91) in order to raise / lower the lower block (3) in order, in a connection phase, to engage the locking element (52) with the complementary locking element (62) and thus pass into the connected configuration and in order, in a disconnection phase, to release the locking element (52) from the complementary locking element (62) and thus pass into the disconnected configuration, said lifting device (1) being characterized in that it comprises a sensor (81) for measuring a force (Fl) on a strand of the lifting cable (90), and the control / command unit (8) is connected to said sensor (81) to receive data measuring the force (Fl) on the strand of the lifting cable (90) and is configured to automatically control a change of hauling based on the data measuring the force (Fl) on the strand of the lifting cable (90), said control / command unit (8) being configured to control the lifting winch (91) in the connection phase and in the disconnection phase depending on said data measuring the force (Fl) on the strand of the lifting cable (90).

2. Lifting machine (1) according to claim 1, in which the control / command unit (8) is configured to control the lifting winch (91) in the connection phase and in the disconnection phase as a function of a variation in the force (Fl) on the strand of the lifting cable (90).

3. Lifting machine (1) according to claim 1 or 2, in which the control / command unit (8) is configured to, in the connection phase, control the lifting winch (91) in order to raise the lower block (3), until a predefined increase in the force (Fl) on the strand of the lifting cable (90) is detected.

4. Lifting machine (1) according to claim 3, in which the increase in the force (Fl) on the strand of the lifting cable (90) is characterized by an excess of the force (Fl) beyond a given connection force threshold, or by a variation slope of the force (Fl) above a given connection slope value.

5. Lifting machine (1) according to claim 3 or 4, in which the control / command unit (8) is configured to, in the connection phase, control the lifting winch (91) in order to continue the raising of the lower block (3) until a reduction in the force (Fl) on the strand of the lifting cable (90) is detected, after the predefined increase, and to stop the raising of the lower block (3) in response to the detection of said reduction in the force (Fl) on the strand of the lifting cable (90).

6. Lifting machine (1) according to claim 5, in which the control / command unit (8) is configured to, in the connection phase and after having stopped the ascent of the lower block (3), control the lifting winch (91) in order to lower the lower block (3).

7. Lifting machine (1) according to any one of the preceding claims, in which the control / command unit (8) is configured to, in the disconnection phase, control the lifting winch (91) in order to raise the lower block (3), until an increase is detected predefined force (Fl) on the strand of the lifting cable (90) to stop the rise of the lower block (3).

8. Lifting machine (1) according to claim 6, wherein the predefined increase in the force (Fl) on the strand of the lifting cable (90) is characterized by an excess of the force (Fl) above a given disconnection force threshold.

9. Lifting machine (1) according to claim 6 or 7, in which the control / command unit (8) is configured to, in the disconnection phase and after having stopped the ascent of the lower block (3), control the lifting winch (91) in order to lower the lower block (3).

10. A lifting machine (1) according to any preceding claim, wherein the sensor (81) is a load sensor mounted on the lifting machine (1) to be able to measure a self-weight of the lower block (3).

11. Lifting machine (1) according to claim 9, in which the load sensor is a gauge axis mounted on a lifting cable return system (90).

12. A lifting device (1) according to any preceding claim, wherein the locking element (52) is a latch pivotally mounted on one of the two blocks (3, 4) for movement within a locking channel (53), and the complementary locking element (62) is a shaft mounted on the other of the two blocks (3, 4).

13. Method for changing the hauling system in a lifting machine (1) according to any one of the preceding claims, in which the control / command unit (8) receives from the sensor (81) data measuring the force (Fl) on the strand of the lifting cable (90) and automatically controls a change of hauling system based on the data measuring the force (Fl) on the strand of the lifting cable (90), by controlling the lifting winch (91) in the connection phase and in the disconnection phase according to said data measuring the force (Fl) on the strand of the lifting cable (90).

Images