Pitching cantilever tower crane equipped with an adjustable wind load system

Abstract

A tower crane includes a tower, a cantilever (1) pivotally mounted on the tower, the cantilever (1) being movable in raising and lowering between a lowered position and an elevated position, the crane being configured between a service configuration and a safety configuration, in which the cantilever is controlled in rotation, and in the safety configuration, the cantilever is in an elevated position and released in rotation on the tower to be oriented in the direction of the wind, a wind load system (2) mounted on the cantilever and adjustable between a retracted shape and an extended shape, the retracted shape being used in the service configuration to provide a reduced surface exposed to the wind, and the extended shape being used in the safety configuration to provide an extended surface exposed to the wind, the wind load system being designed to move from the retracted shape to the extended shape only under its own weight when the cantilever is raised.

Description

Technical Field

[0001] This invention relates to a pitching cantilever tower crane equipped with an adjustable wind load system. Furthermore, this invention relates to a method for fixing a pitching cantilever tower crane.

[0002] This invention applies to the field of tower cranes including those with pitching cantilever jibs, and can be applied to various crane structures, such as those consisting of trusses and chords. Background Technology

[0003] Traditionally, tower cranes consist of a tower on which a cantilever is pivotally mounted about a generally vertical directional axis. The cantilever can be moved between a lowered position and an elevated position, for example by means of a hydraulic system or cable system.

[0004] Furthermore, this type of tower crane can be constructed between the following:

[0005] - Service configuration in which the rotation of the cantilever on the tower about an directional axis is controlled (also known as directional control), thereby displacing the load by means of a lifting system supported by the cantilever, and

[0006] - A safety configuration in which the cantilever is in an elevated position and its rotation on the tower about a directional axis is released so that it can be oriented in the direction of the wind. The cantilever then rotates freely about the directional axis and is generally said to become a wind vane.

[0007] In practice, for safety reasons, and especially in strong winds, it is recommended or even mandatory to allow the tower crane to rotate freely by separating the cantilever (in other words, by releasing the cantilever from the tower, for example by unlocking the directional brake) to automatically orient it in the direction of the wind and thus allow the tower crane to leave unsupervised, thus making the tower crane safe (also known as wind vaneing of the cantilever).

[0008] In the case of a pitching cantilever crane, wind vaneing is performed when the cantilever is in an elevated configuration to minimize the cantilever's turning radius and thus prevent the cantilever from acting as a wind vane over surfaces near the construction site, such as driveways or buildings.

[0009] When a crane is in a safe configuration, the balance between wind loads on the cantilever must be favorable relative to the downwind load (at the opposing cantilever) so that the cantilever can naturally orients itself in the wind. However, on a pitch cantilever crane, as the cantilever rises, the directional torque generated by the wind force on the cantilever is reduced, and wind heading (or alignment in the direction of the wind) becomes later or even more difficult.

[0010] To ensure this wind vane setup, it is known, particularly from document EP3064465, to provide a wind load system (also known as a wing system) on the cantilever, which is equipped with one or more sails that provide adjustable surfaces exposed to the wind, and specifically, to provide such exposed surfaces that, when the cantilever is in a safe configuration, increase, thereby increasing the wind pressure on the crane's cantilever and thus allowing it to be better oriented in the wind direction. Document EP3064465 proposes using a drive mechanism acting on the sails (multiple sails) to deploy them (and thus increase their exposed surfaces to the wind) or retract them (and thus reduce their exposed surfaces to the wind).

[0011] However, the use of such a drive mechanism has the disadvantage of complicating the installation of this wind load system and thus increasing installation costs. This cost increase can be excessive, especially when it is necessary to install a wind load system on an existing crane or redesign the crane to incorporate this feature of an adjustable wind load surface. Furthermore, the presence of an additional drive mechanism in the cantilever makes the cantilever heavier, which is detrimental to the cantilever's load curve and thus reduces the crane's performance. Summary of the Invention

[0012] The object of the present invention is, in particular, to address all or part of the aforementioned disadvantages by proposing a wind load system that is lightweight, simple and inexpensive to facilitate installation on existing cranes or to facilitate the design of new cranes with wind load systems.

[0013] Another object of the present invention is to provide a wind load system that, in particular, allows a large surface exposed to the wind to be deployed in a safe structure due to its lightweight nature. This allows for an increase in the pitch angle of the cantilever (in other words, to make it closer to vertical) and thus a reduction in the turning radius of the cantilever in the safe structure, while allowing for effective alignment in the direction of the wind.

[0014] To this end, the present invention provides a tower crane comprising a tower, a cantilever pivotally mounted on the tower about an directional axis, the cantilever being displaced during lifting and lowering between a lowered position and an elevated position, and the tower crane being configured between a service configuration and a safety configuration, wherein in the service configuration, rotation of the cantilever on the tower about the directional axis is controlled, and in the safety configuration, the cantilever is in the elevated position and rotation on the tower about the directional axis is released to enable orientation in the direction of the wind, wherein the tower crane includes at least one wind load system mounted on the cantilever and adjustable between a retracted shape and an extended shape, the retracted shape being used in the service configuration and in this retracted shape, the wind load system providing a reduced surface exposed to the wind, and the extended shape being used in the safety configuration and in this extended shape, the wind load system providing an extended surface exposed to the wind, the extended surface being larger than the reduced surface exposed to the wind.

[0015] The remarkable feature of this tower crane is that the wind load system is designed so that when the jib is raised to move from the lowered position to the raised position, it moves from the retracted shape to the extended shape solely under its own weight.

[0016] Therefore, this invention proposes to eliminate the drive mechanism for deploying the wind load system and thus increase the surface exposed to the wind by utilizing the weight of the wind load system itself, which will allow deployment by gravity when the cantilever is raised. In other words, as the cantilever is raised, it changes its tilt relative to the vertical direction, and thus the wind load system will naturally change its shape under the action of gravity, which naturally exerts a vertical force on the wind load system.

[0017] This wind load system can therefore be "controlled" by gravity, which avoids adding any static load to the cantilever and thus does not affect the crane's performance. When the crane is in a safe configuration, this wind load system can also naturally have the maximum surface exposed to the wind, and when the crane is in a service configuration and requires directional performance, it can naturally have the minimum surface exposed to the wind.

[0018] It should be noted that, equally naturally, the wind load system is designed to move from the extended shape to the retracted shape under its own weight when the cantilever is lowered to move from the raised position to the lowered position.

[0019] In a particular embodiment, the wind load system includes at least two wing elements, each having at least one freely movable wing element, wherein:

[0020] - In the retracted shape, when the cantilever is in the lowered position, the wing elements overlap each other at least partially in order to provide a reduced surface exposed to the wind;

[0021] - In the deployed shape, when the cantilever is in the raised position, the wing elements are spaced apart from each other to provide extended surfaces exposed to the wind;

[0022] Furthermore, when the cantilever is raised to move from the lowered position to the raised position, the freely movable wing elements only move freely under their own weight.

[0023] Therefore, as the cantilever is raised, the freely movable wing element will "fall" in some way under its own weight, while of course remaining on the cantilever, and it is this movement that changes its shape.

[0024] It should be noted that, equally naturally, when the cantilever is lowered from the raised position to the lowered position, the freely movable wing element moves freely only under its own weight.

[0025] According to one characteristic, a freely movable wing element can move at least rotatably.

[0026] Therefore, when the cantilever is raised, the freely movable wing element will pivot at least under its own weight.

[0027] According to one possible approach, the freely movable wing element can rotate about the same axis of rotation.

[0028] According to another feature, the freely movable wing element can move at least slidably.

[0029] Therefore, when the cantilever is raised, the freely movable wing element will slide, at least under its own weight.

[0030] According to another possible approach, the wind load system includes at least one stop associated with a freely movable wing element to stop the movement of the freely movable wing element when the cantilever is raised to move from a lowered position to a raised position.

[0031] The presence of a stop is advantageous in that it can stop the free wing element associated with the “right place” so that it has a surface exposed to the maximum wind. The stop provides control over the extent of deployment or the final positioning of the free wing element.

[0032] According to another possible approach, the wind load system includes a static wing element and one or more freely movable wing elements, which, in the retracted shape, at least partially overlap in front of or behind the static wing element.

[0033] In a particular embodiment, the airfoil element of the wind load system is at least partially made of a material selected from metallic materials (such as, for example, aluminum), plastic materials, textile materials, and composite materials.

[0034] According to one possible scheme, the airfoil elements of the wind load system are planar and parallel to each other in their unfolded shape.

[0035] The present invention also relates to a fixing method for fixing a tower crane according to the present invention, comprising:

[0036] - The step of releasing the cantilever on the rotation of the tower around the directional axis to be able to orient it in the direction of the wind;

[0037] - The step of raising the cantilever from a lowered position where the wind load system is in its retracted shape to a raised position where the wind load system is in its extended shape;

[0038] During the cantilever's ascent, the wind load system moves from the retracted shape to the unfolded shape solely under its own weight.

[0039] In embodiments with wing elements, during the cantilever elevation, the freely movable wing elements are displaced under their own weight to increase the wind load system’s exposure to the wind surface. Attached Figure Description

[0040] Other features and advantages of the invention will become apparent upon reading the following detailed description of examples of non-limiting embodiments with reference to the accompanying drawings, in which:

[0041] Figure 1 This is a schematic side view and partial view of the cantilever of a tower crane according to the invention, the cantilever being in a lowered position and supporting a first wind load system according to the invention, and the first wind load system being in a retracted position;

[0042] Figure 2 yes Figure 1 A schematic side view and partial view of the cantilever, with the cantilever in the raised position and the first wind load system in the deployed position;

[0043] Figure 3 This is a schematic side view and partial view of the cantilever of a tower crane according to the invention, the cantilever being in a lowered position and supporting a second wind load system according to the invention, and the second wind load system being in a retracted position.

[0044] Figure 4 yes Figure 3 A schematic side view and partial view of the cantilever, with the cantilever in the raised position and the second wind load system in the deployed position;

[0045] Figure 5This is a schematic side view and partial view of the cantilever of a tower crane according to the invention, the cantilever being in a lowered position and supporting a third wind load system according to the invention, and the third wind load system being in a retracted position.

[0046] Figure 6 yes Figure 5 A schematic side view and partial view of the cantilever, with the cantilever in the raised position and the third wind load system in the deployed position;

[0047] Figure 7 This is a schematic side view and partial view of the cantilever of a tower crane according to the invention, the cantilever being in a lowered position and supporting a fourth wind load system according to the invention, and the fourth wind load system being in a retracted position.

[0048] Figure 8 yes Figure 7 A schematic side view and partial view of the cantilever, with the cantilever in the raised position and the fourth wind load system in the deployed position. Detailed Implementation

[0049] The tower crane according to the present invention includes:

[0050] - A tower (also called a support), which extends vertically and is anchored to the ground or movable over the ground; and

[0051] - A rotating section that spans the tower and is pivotally mounted on the top of the tower along an orientation axis corresponding to a vertical axis parallel to the vertical direction Z as shown in the figure.

[0052] The rotating section mainly includes:

[0053] - A rotating pivot, which forms a directional device typically equipped with a directional brake, is mounted on top of the tower and typically supports the cockpit;

[0054] - A counterweight mounted on a counterweight that extends substantially horizontally rearward from the rotation pivot; and

[0055] - A cantilever 1 of the pitch cantilever type, which extends substantially forward from the rotation pivot along the longitudinal axis 10.

[0056] The rotating pivot can be oriented about the orientation axis, and therefore the cantilever 1 is pivotally mounted on the tower about the orientation axis.

[0057] The cantilever 1 can be formed from, for example, a truss structure with a triangular cross-section. The cantilever 1 has a proximal portion mounted on a rotation pivot, which forms the base of the cantilever 1. The cantilever 1 also has a free distal portion 11, which forms the end of the cantilever 1.

[0058] Furthermore, the proximal portion is hinged to a rotation pivot about a horizontal pivot axis, allowing cantilever 1 to pivot upwards or downwards about this horizontal pivot axis, and thus cantilever 1 is a so-called pitch cantilever, in this sense, it can be displaced in raising and lowering between the following:

[0059] - Lower the position (in) Figure 1 , 3 (See in 5 and 7), wherein the cantilever 1 extends substantially horizontally, and the longitudinal axis 10 is substantially parallel to the horizontal direction X; and

[0060] - Elevate position (in) Figure 2 , 4 (See in 6 and 8), wherein the cantilever 1 extends obliquely, wherein the longitudinal axis 10 is tilted relative to the horizontal direction X at an angle of at least 30 degrees or 45 degrees, or even at least 60 degrees, and the distal portion 11 has been installed compared to the lowered position.

[0061] Tower cranes can also be constructed between the following:

[0062] - Service configuration, wherein the rotation of cantilever 1 on the tower about an directional axis is controlled, typically by means of directional motorization specifically designed to rotate the rotating portion; and

[0063] -Safety configuration, wherein the cantilever 1 is in the raised position and rotation on the tower about the directional axis is released so that it can be oriented in the direction of the wind, for example after disengaging from the directional brake set on the rotation pivot.

[0064] According to the present invention, the tower crane further includes at least one wind load system 2, 3, 4, 5, which is mounted on the cantilever 1 and is adjustable between the following:

[0065] -Retract the shape (in) Figure 1 , 3 (See sections 5 and 7), which are used in service structures and in which wind load systems 2, 3, 4, and 5 provide reduced surfaces exposed to wind; and

[0066] - Unfold the shape (in) Figure 2 , 4 (See in 6 and 8), which is used in the safety structure (so when cantilever 1 is in the raised position), and in which wind load systems 2, 3, 4, 5 provide a larger extended wind surface than the reduced surface exposed to the wind.

[0067] Figures 1 to 8 Four exemplary embodiments of wind load systems 2, 3, 4, and 5 are shown, wherein the first wind load system 2 is... Figure 1 and 2 In the middle, the second wind load system 3 is Figure 3 and 4 In the middle, the third wind load system 4 is Figure 5 and 6 In the middle, and the fourth wind load system 5 in Figure 7 and 8 middle.

[0068] Generally, wind load systems 2, 3, 4, and 5 are designed as follows:

[0069] - When cantilever 1 is raised to move from the lowered position to the raised position, it moves from the retracted shape to the unfolded shape solely under its own weight (in other words, under gravity), and vice versa.

[0070] - When cantilever 1 is lowered to move from the raised position to the lowered position, it moves from the unfolded shape to the retracted shape solely under the influence of its own weight (in other words, under the influence of gravity).

[0071] In the four illustrated embodiments, wind load systems 2, 3, 4, and 5 include at least two wing elements 20, 21, 30, 31, 40, 41, 50, and 51, one or more of which are freely movable, wherein:

[0072] - In the retracted shape, when the cantilever 1 is in the lowered position, the wing elements 20, 21, 30, 31, 40, 41, 50, 51 at least partially overlap each other in order to provide a reduced surface exposed to the wind;

[0073] - In the deployed configuration, when the cantilever 1 is in the raised position, the wing elements 20, 21, 30, 31, 40, 41, 50, and 51 are spaced apart from each other to provide extended surfaces exposed to the wind.

[0074] More precisely, when the cantilever 1 is raised to move from the lowered position to the raised position (and vice versa), the (multiple) freely movable wing elements 20, 21, 31, 41, 51 move freely only under their own weight (in other words, under the influence of gravity).

[0075] Advantageously, the following are provided for each freely movable wing element 20, 21, 31, 41, 51:

[0076] - A first stop, which, when the cantilever 1 is raised, stops the movement of the freely movable wing element so that once the cantilever 1 is in the raised position, the freely movable wing element is stopped in the optimal deployment position, thereby providing maximized wind exposure surface; and

[0077] - A second stop, which stops the movement of the freely movable wing element when the cantilever 1 is lowered, so as to stop the freely movable wing element in the optimal retracted position once the cantilever 1 is in the lowered position, thereby providing a minimized (through overlap between wing elements) surface exposed to the wind.

[0078] In the first wind load system 2, the wing elements 20 and 21 are in the form of flexible bellows mounted on a rigid frame 22, for example, made of textile material. The rigid frame 22 pivots on the cantilever 1 about the same lateral pivot axis 23, which is perpendicular to both the vertical direction Z and the longitudinal axis 10. This lateral pivot axis 23 is horizontal and independent of the position of the cantilever 1. The wing elements 20 and 21 of the first wind load system 2 are both freely movable.

[0079] In the retracted shape, wing elements 20 and 21 overlap and fold. As the cantilever 1 is raised, the rigid frame 22 of wing elements 20 and 21 (under their weight) pivots about the lateral pivot axis 23 (as schematically shown by arrow P2), and thus wing elements 20 and 21 unfold, thereby providing an increase in the surface exposed to the wind (like a fan).

[0080] In the second wind load system 3, the wing elements 30 and 31 are in the form of wind vanes mounted on a rigid frame, for example, made of rigid metal, composite material, plastic, or flexible material, and include:

[0081] One or more freely movable wing elements 31 are pivotally mounted on the cantilever 1 about the same lateral pivot axis 33, which is perpendicular to the vertical direction Z and the longitudinal axis 10. The lateral pivot axis 23 is horizontal and independent of the position of the cantilever 1.

[0082] The static wing element 30 remains static and does not pivot during the raising of the cantilever 1.

[0083] In the illustrated example, there are two freely movable wing elements 31. In the retracted shape, wing elements 30 and 31 overlap each other. As the cantilever 1 is raised, the freely movable wing elements 31 (under their own weight) pivot about the lateral pivot axis 33 (as schematically shown by arrow P3), and thus the freely movable wing elements 31 unfold and move away from the static wing member 30, thereby providing an increase in the surface exposed to the wind.

[0084] In the third wind load system 4, the wing elements 40 and 41 are in the form of wind vanes mounted on a rigid frame, for example, made of rigid metal, composite or plastic materials, or made of flexible materials, and include:

[0085] One or more freely movable wing elements 41 are slidably mounted on the cantilever 1 along the longitudinal axis 10;

[0086] The static wing element 40 remains static and does not slip during the raising of the cantilever 1.

[0087] In the example shown, the number of freely movable wing elements 41 is small, but there is only one. In the retracted shape, wing elements 40, 41 overlap each other. As the cantilever 1 is raised, the freely movable wing element 31 (under its own weight) slides along the longitudinal axis 10 (as schematically shown by arrow C4), and thus the freely movable wing element 41 unfolds and moves away from the static wing member 40, thereby providing an increase in the surface exposed to the wind (like an open drawer).

[0088] In the fourth wind load system 5, the wing elements 50 and 51 are in the form of wind vanes mounted on a rigid frame, for example, made of rigid metal, composite or plastic materials, or made of flexible materials, and include:

[0089] One or more freely movable wing elements 51 are pivotally mounted on the cantilever 1 about the same lateral pivot axis 53, which is perpendicular to the vertical direction Z and the longitudinal axis 10. The lateral pivot axis 53 is horizontal and independent of the position of the cantilever 1.

[0090] A static wing element 50, which keeps it static and does not pivot during the raising of the cantilever 1, wherein the static wing element 50 is in the form of a disk centered on a lateral pivot axis 53 and having a plurality of windows 52.

[0091] In the retracted shape, wing elements 50, 51 overlap each other, causing the freely movable wing element 51 to release window 52. As cantilever 1 is raised, the freely movable wing element 51 (under its own weight) pivots about the lateral pivot axis 53 (as schematically shown by arrow P5), and thus the freely movable wing element 51 unfolds and moves away from the static wing element 50 to occupy or cover window 52, ​​thereby providing an increase in the surface exposed to the wind (in the form of a vent).

[0092] exist Figure 1 and Figure 2 In the example, the tower crane includes multiple wind load systems 2, which can be connected by links 6 to allow for parallel and synchronous movement during deployment and retraction.

[0093] Furthermore, it should be noted that, given the simplicity of these wind load systems 2, 3, 4, and 5 that do not use any actuators, it is straightforward to install any of these wind load systems 2, 3, 4, and 5 as initial equipment (in other words, for the manufacture of tower cranes) or during the upgrade or improvement of existing tower cranes.

Claims

1. A tower crane comprising a tower, a cantilever (1) pivotally mounted on the tower about an directional axis, the cantilever (1) being displaceable in raising and lowering between a lowered position and an elevated position, the tower crane being operable between a service configuration and a safety configuration, wherein in the service configuration, rotation of the cantilever (1) about the directional axis on the tower is controlled, and in the safety configuration, the cantilever (1) is in an elevated position and rotation about the directional axis on the tower is released to enable orientation in the direction of wind, the tower crane... The crane includes at least one wind load system (2; 3; 4; 5) mounted on the cantilever (1) and adjustable between a retracted shape and an extended shape, the retracted shape being used in the service configuration and in the retracted shape, the wind load system (2; 3; 4; 5) providing a reduced surface exposed to wind, the extended shape being used in the safety configuration and in the extended shape, the wind load system (2; 3; 4; 5) providing an extended surface exposed to wind, the extended surface being larger than the reduced surface exposed to wind, characterized in that... The wind load system (2; 3; 4; 5) is designed to move from the retracted shape to the deployed shape only under its own weight when the cantilever (1) is raised to move from the lowered position to the raised position.

2. The tower crane according to claim 1, wherein, The wind load system (2; 3; 4; 5) includes at least two wing elements (20, 21; 30, 31; 40, 41; 50, 51), each having at least one freely movable wing element (20, 21; 31; 41; 51), wherein: - In the retracted shape, when the cantilever (1) is in the lowered position, the wing elements (20, 21; 30, 31; 40, 41; 50, 51) overlap each other at least partially to provide a reduced surface exposed to the wind; - In the deployed shape, when the cantilever (1) is in the raised position, the wing elements (20, 21; 30, 31; 40, 41; 50, 51) are spaced apart to provide an extended surface exposed to the wind; Furthermore, when the cantilever (1) is raised to move from the lowered position to the raised position, the freely movable wing elements (20, 21; 31; 41; 51) move freely only under their own weight.

3. The tower crane according to claim 2, wherein, The freely movable wing elements (20, 21; 31; 51) can move at least rotatably.

4. The tower crane according to claim 3, wherein, The freely movable wing elements (20, 21; 31; 51) can rotate about the same axis of rotation (23; 33; 53).

5. The tower crane according to claim 2, wherein, The freely movable wing element (41) can move at least slidably.

6. The tower crane according to claim 2, wherein, The wind load system (2; 3; 4; 5) includes at least one stop associated with the freely movable wing element (20, 21; 31; 41; 51) to stop the movement of the freely movable wing element (20, 21; 31; 41; 51) when the cantilever (1) is raised to move from the lowered position to the raised position.

7. The tower crane according to claim 2, wherein, The wind load system (3; 4; 5) includes a static wing element (30; 40; 50) and one or more freely movable wing elements (31; 41; 51), in the retracted shape, the one or more freely movable wing elements (31; 41; 51) at least partially overlap the front or rear of the static wing element (30; 40; 50).

8. The tower crane according to claim 2, wherein, The wing elements (20, 21; 30, 31; 40, 41; 50, 51) of the wind load system (2; 3; 4; 5) are made at least in part of one of the following materials: metal, plastic, textile, or composite.

9. The tower crane according to claim 2, wherein, The wing elements (20, 21; 30, 31; 40, 41; 50, 51) of the wind load system (2; 3; 4; 5) are planar and parallel to each other in the deployed shape.

10. A method for fixing a tower crane according to claim 1, comprising: - The step of releasing the cantilever (1) on the tower about the orientation axis so as to be able to orient in the direction of the wind; - The step of raising the cantilever (1) from a lowered position in its retracted shape to a raised position in its extended shape of the wind load system (2; 3; 4; 5); During the raising of the cantilever (1), the wind load system (2; 3; 4; 5) moves from the retracted shape to the unfolded shape only under its own weight.

11. The fixing method according to claim 10, wherein, The wind load system (2; 3; 4; 5) of the tower crane includes at least two wing elements (20, 21; 30, 31; 40, 41; 50, 51), each having at least one freely movable wing element (20, 21; 31; 41; 51), wherein, - In the retracted shape, when the cantilever (1) is in the lowered position, the wing elements (20, 21; 30, 31; 40, 41; 50, 51) overlap each other at least partially to provide a reduced surface exposed to the wind; - In the deployed shape, when the cantilever (1) is in the raised position, the wing elements (20, 21; 30, 31; 40, 41; 50, 51) are spaced apart to provide an extended surface exposed to the wind; Furthermore, when the cantilever (1) is raised to move from the lowered position to the raised position, the freely movable wing elements (20, 21; 31; 41; 51) move freely only under their own weight. Furthermore, during the raising of the cantilever (1), the freely movable wing elements (20, 21; 31; 41; 51) are free to move under their own weight only to increase the surface of the wind load system (2; 3; 4; 5) exposed to the wind.

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