Device for pulling beams out of the ground

Abstract

Device for extracting beams (10) from the ground comprising a base plate (20) with an opening (21) for placing on the ground around the beam (10) to be extracted, and a housing (30) arranged above the opening (21) of the base plate, open upwards and downwards, in which at least two clamping devices (31) with clamping jaws (32) are arranged on opposite sides, which are movable between a rest position and a working position, wherein the clamping devices (31) in the working position secure the beam (10) between the clamping jaws (32) and release the beam (10) in the rest position, wherein the device has at least two lifting devices (40) with drive, each of which is rotatably attached at its lower end to the base plate (10) about at least a first axis (41) and rotatably attached at its upper end to the housing (30) about at least a second axis (42),wherein the drives of the lifting devices (40) are configured such that a compensation of the pressure forces on the lifting devices (40) is automatically achieved during operation of the device.

Description

Field of invention

[0001] The invention relates to the field of civil engineering, in particular methods for pulling out no longer needed supports of sheet pile walls or soldier pile walls from the ground. Background of the invention

[0002] Sheet pile walls are structures used to secure excavations or changes in elevation and can also serve as a sealing element. They typically consist of individual profiles called sheet piles or sheet piles. These profiles are driven, vibrated, or pressed into the ground and connected by interlocking tongue-and-groove joints, creating a continuous wall. Sheet pile walls are usually made of structural steel, but they can also be made of reinforced concrete, plastic, or wood.

[0003] Sheet piles can have various cross-sectional shapes, such as U-profiles, Z-profiles, T-profiles, I-profiles, IPE-profiles, HEA-profiles, or HEB-profiles, and are typically used in lengths of approximately 6 to 30 meters. Sheet piles are frequently used in areas where space constraints prevent the construction of a slope or where sealing against pressurized water is required. They are also used in hydraulic engineering, for example, for quay walls, lock walls, and flood protection.

[0004] Soldier pile walls, also known as Berlin-style retaining walls, are a well-known method for securing excavation pits, usually as temporary structures. They consist of vertically installed steel beams with horizontal bracing, typically made of timber planks, placed between them. Construction of a soldier pile wall begins with the installation of the beams, which are driven into the ground at regular intervals along the edge of the excavation. Timber planks or other materials such as shotcrete, reinforced concrete, or steel elements are then inserted between the exposed flanges of the beams and wedged into the ground. For deeper excavations, the soldier pile walls are often additionally secured with grouted anchors or bracing. Soldier pile walls are particularly flexible in adapting to various ground plan shapes and are frequently used in urban areas where noise and vibrations must be minimized.The beams typically have an H-profile, double-T-profile or I-profile in cross-section, but can also have other profiles.

[0005] Various technologies are used for installing sheet piles and beams for soldier pile walls. In driving, the weight and drop height of a hammer, such as a free-fall or hydraulic hammer, are used to drive the sheet piles or beams into the ground. Vibrating is a vibration method in which the sheet piles or beams are driven into the ground by vibrations. Hydraulic jacks use hydraulic forces to press the sheet piles or beams into the ground.

[0006] A key problem with the use of sheet pile walls and soldier pile walls is the complex dismantling of the sheet piles and beams after construction is complete. Traditionally, this is done using vibrators, which requires heavy cranes and is time-consuming. Furthermore, this method inevitably causes vibrations, which are often undesirable.

[0007] In addition to traditional methods, techniques for extracting or pushing out the beams of sheet pile walls from the ground have become known in recent years. These techniques often use hydraulic or pneumatic pistons to move the beams that are vertically inserted into the ground.

[0008] Document DE 20 2016 100 311 U1, for example, describes a device that enables the low-vibration removal of a profile beam from the ground. The device comprises a receiving device that secures the profile beam and a pressing device that pushes the profile beam vertically upwards. The receiving device is designed to secure the profile beam by friction and features reinforcements that support the profile beam during this process. The pressing device, preferably a hydraulic cylinder, pushes the receiving device and the profile beam upwards, thereby releasing the profile beam from its anchorage.

[0009] Document DE 20 2017 104 471 U1 describes a device for extracting a vertical beam of a sheet pile wall from the ground. The device comprises a base plate positioned laterally next to the beam on the ground and at least two hydraulic or pneumatic pistons articulated to opposite sides of the beam. The pistons are equipped with fasteners that can be attached to the beam to pull it out of the ground by applying pressure.

[0010] Document DE 20 2020 100 504 U1 describes a device for pressing or pulling out a vertical beam of a sheet pile wall from the ground. The device comprises at least two hydraulic or pneumatic pistons that are supported on a base plate and engage a lifting plate. The lifting plate has an opening larger than the outer dimension of the beam and is provided with clamping means that clamp the web of the beam between them. When the pistons are actuated, the lifting plate, with the beam, is pulled upwards out of the ground.

[0011] While the aforementioned methods and devices represent progress in the dismantling of sheet pile walls, they are not without drawbacks. All of these devices are designed for the vertical extraction or pressing out of the piles, meaning they only operate effectively if the pile is perfectly vertical in the ground. In practice, however, it is often the case that the piles are not always perfectly vertical due to settlement or other factors. In such cases, an unfavorable force distribution can occur, which impairs both the efficiency of the extraction process and increases the risk of damage to the extraction devices or the piles being removed.In particular, an uneven load distribution can cause the base plate of the extension device to break or the device to tip over due to the ground giving way, which poses a significant safety risk to the operating personnel. The problem underlying the invention

[0012] The invention is based on the objective of providing a device by means of which beams that are not installed exactly vertically can be pulled out of the ground easily, safely, and efficiently. Furthermore, it should of course be possible to pull perfectly vertically aligned beams out of the ground easily and efficiently.

[0013] Another objective of the invention is to provide a device that is robust in use, even under adverse conditions on a construction site. Inventive solution

[0014] These problems are solved according to the invention by a device according to claim 1. Advantageous embodiments of the device are specified in the dependent claims.

[0015] In the following, the terms "have," "exhibit," "comprise," or "include," or any grammatical variations thereof, are used in a non-exclusive manner. Accordingly, these terms can refer to situations in which, besides the feature introduced by these terms, no other features are present, or to situations in which one or more other features are present.

[0016] Furthermore, it should be noted that the terms "at least one" and "one or more," as well as grammatical variations of these terms or similar terms, when used in connection with one or more elements or features and intended to express that the element or feature may be present once or multiple times, are generally used only once, for example, when the feature or element is first introduced. Upon subsequent mention of the feature or element, the corresponding term "at least one" or "one or more" is generally no longer used, without restricting the possibility that the feature or element may be present once or multiple times.

[0017] Furthermore, the terms "preferably," "in particular," "for example," or similar terms are used in the following text in connection with optional features without limiting alternative embodiments. Features introduced by these terms are optional features, and it is not intended that these features limit the scope of protection of the claims, and in particular the independent claims. As the person skilled in the art will recognize, the invention can also be implemented using other embodiments. Similarly, features introduced by "in one embodiment of the invention" or by "in an exemplary embodiment of the invention" are understood as optional features without limiting alternative embodiments or the scope of protection of the independent claims.Furthermore, these introductory expressions are intended to leave all possibilities of combining the features introduced herein with other features, whether optional or non-optional features, unaffected.

[0018] Measurements are referred to below using their usual abbreviations. In particular, the units centimeter are abbreviated as "cm", meter as "m", degree as "°" and percent as "%".

[0019] One aspect of the invention relates to a device for extracting beams from the ground, comprising a base plate with an opening for placing the beam to be extracted on the ground, and a housing arranged above the opening of the base plate, open upwards and downwards, in which at least two clamping devices with clamping jaws are mounted on opposite sides, the clamping devices being movable between a rest position and a working position, wherein in the working position the clamping devices secure the beam between the clamping jaws and in the rest position release the beam, wherein the device has at least two lifting devices with drives, each rotatably attached at its lower end to the base plate about at least a first axis and rotatably attached at its upper end to the housing about at least a second axis, wherein the drives of the lifting devices are configuredthat during operation of the device, the pressure forces on the lifting mechanisms are automatically balanced.

[0020] In the context of the drive system, "compensation of pressure forces" means that the pressure exerted by a drive on a lifting device is essentially the same for all lifting devices. The term "essentially the same" in this context means that only minor deviations occur due to technical factors, such as typical design tolerances. Preferably, the pressures applied to the individual lifting devices do not differ from each other by more than five percent. In some embodiments, the terms "hydrostatic compensation" or "principle of hydrostatic compensation" are used synonymously with "compensation of pressure forces."

[0021] In prior art methods that have at least two lifting devices, the same quantities of working medium, in particular hydraulic fluid, are usually supplied to the respective lifting devices. However, in the case of beams embedded at an angle in the ground, this leads to the device also tilting due to the high forces and pressing into the ground with significantly higher pressure on one side than on the opposite side.

[0022] In contrast, implementing pressure force balancing enables efficient and safe control of the device by ensuring uniform pressure distribution and synchronization of the lifting mechanism's movements. For example, when working with an inclined beam, the drive system can adjust the amount of working fluid to each lifting mechanism to maintain consistent pressure.

[0023] Particularly in the case of inclined beams, where varying loads act on the individual pistons, the automatic compensation of pressure forces ensures that the device operates safely and stably. The risk of damage to the device or the beam is significantly reduced. The safety of operating personnel on a construction site is also increased, as the risk of the device tipping over under excessive load is eliminated. Preferred embodiments of the invention

[0024] Advantageous training and further education programs, which can be used individually or in combination, are the subject of the dependent claims and the following description.

[0025] The term "beam" encompasses all structural elements used in civil engineering that are suitable for being driven into the ground to construct, for example, sheet pile walls or soldier pile walls. Examples of beams include sheet piles, sheet piles, and vertical beams. Beams can have common cross-sectional profiles, such as U-profiles, Z-profiles, T-profiles, I-profiles, H-profiles, I-profiles, IPE-profiles, HEA-profiles, or HEB-profiles.

[0026] The device comprises a base plate with an opening. To pull a beam from the ground, the base plate with the opening is placed on the ground around the beam to be extracted. The base plate can be made of various materials, such as steel, aluminum, other metals, or high-strength plastic. Preferably, the base plate is made of steel.

[0027] The shape and dimensions of the base plate can be adapted to the specific requirements to provide a stable base for the device. For example, the shape of the outer edge of the base plate can be round, oval, rectangular, square, or polygonal. Preferably, the shape of the outer edge of the base plate is rectangular or square. The corners can be rounded or beveled. The base plate can be a single piece or multi-part with two or more sub-plates. Preferably, it is a single piece.

[0028] The dimensions of the base plate can vary depending on the application; preferably, the length of the base plate is from 120 cm to 160 cm, its width from 90 cm to 130 cm, and its thickness from 15 mm to 25 mm.

[0029] In one embodiment, the base plate has a central opening through which the support beam is pulled. The term "central" in this context means that the opening is located in the base plate. The opening can be arranged in the center of the base plate, and in particular, it can be axially or point-symmetrically positioned in the center of the base plate. It has a clear opening that is larger than the outer dimensions of the support beam. The shape of the opening can be any suitable shape, for example, rectangular, square, or round, depending on the specific requirements of the application. The central opening makes it possible to lift the base plate over the support beam, which protrudes from the ground, and position it on the ground.

[0030] In one embodiment, the opening extends to an edge of the base plate. In this embodiment, the device can be positioned around the support not only by raising and lowering it, but also by a horizontal displacement around the support.

[0031] The base plate can be reinforced to increase its structural integrity. These reinforcements can take the form of ribs or struts, which may be located, for example, on the top or bottom of the base plate. Furthermore, the base plate can be equipped with attachment points or eyelets to securely anchor or transport the device.

[0032] The base plate can also be provided with a non-slip surface to prevent slippage during operation. This surface can be achieved by applying a special coating or by embossing a pattern into the base plate material. A non-slip surface contributes to the safety and stability of the lifting device and ensures a secure footing on various surfaces.

[0033] The housing can have different shapes and dimensions, which can be adapted to the specific requirements, in particular the profile of the extendable support.

[0034] In one embodiment, the housing is essentially cylindrical, where "essentially" in this context means that the basic shape of the housing is cylindrical, but it may deviate from the mathematical definition of a cylinder, for example, by having attachments or bulges. In cross-section, the housing can have any shape suitable for being arranged around a support, in particular ensuring a distance between the inner wall of the housing and the outer surfaces of the support. Preferably, the cross-section of the housing is round, oval, rectangular, square, or polygonal. A rectangular or square cross-section is preferred. The corners may be rounded or beveled.

[0035] The housing can be made of various materials, such as steel, aluminum, other metals, or high-strength plastic. Preferably, the housing is made of structural steel.

[0036] The device has at least two lifting devices, each rotatably attached to the base plate at its lower end about at least one first axis and rotatably attached to the housing at its upper end about at least one second axis. The lifting devices can be of different designs to pull the support out of the ground. They can, for example, include hydraulic, pneumatic, or electric systems, each offering specific advantages and applications.

[0037] The lifting device can incorporate a hydraulic system consisting of one or more hydraulic cylinders. These cylinders can be connected to a hydraulic pump that pressurizes hydraulic fluid as the working medium, thereby moving the cylinders. Hydraulic systems offer the advantage of high power transmission and are particularly suitable for heavy loads and demanding conditions. They enable precise control of the lifting movement and can also be used in confined or difficult-to-access areas.

[0038] Alternatively, the lifting device can incorporate a pneumatic system powered by compressed air. The pneumatic cylinders can be connected to a compressor that forces compressed air to the cylinders to generate the necessary lifting force to pull the beam out of the ground. Pneumatic systems are easy to maintain and, due to the use of air as the working medium, are environmentally friendly.

[0039] The lifting device can also be implemented as an electric system, preferably comprising electric motors and mechanical gearboxes. These motors can drive spindles or racks that move the housing vertically and, in conjunction with the clamping devices, pull the support out of the ground. Electric systems offer the advantage of simple and precise control and can be integrated into automated processes. They are particularly suitable for applications requiring high precision and repeatability. They are environmentally friendly because they produce no emissions and, especially when using renewable energy, can be operated in a CO2-neutral manner.

[0040] The lifting devices each comprise at least one drive, the drives of which are configured such that pressure forces are automatically balanced during operation of the device. The configuration of the drives can vary, for example, depending on the type of drive. In one variant, the drives of the lifting devices are interconnected into a common drive system based on the principle of hydrostatic balancing.

[0041] In one embodiment, the lifting devices each have at least one piston that is movable within a cylinder. The drive system is preferably a pneumatic or hydraulic system in which the automatic compensation of the pressure forces is implemented by the interconnection of the fluid flows and / or by control elements for influencing the fluid flow.

[0042] In one variant of this embodiment, the fluid lines to the individual lifting devices are connected in parallel, so that the same pressure is applied to all lifting devices. In another variant, control elements are used to influence the fluid flow. In yet another variant, the automatic compensation of the pressure forces is achieved both by the interconnection of the fluid flows and by control elements for influencing the fluid flow.

[0043] In a pneumatic system, the automatic compensation of pressure forces can be achieved, for example, through appropriate interconnections of the fluid lines, the use of distributors, control blocks and / or by using control valves that adjust the flow rates of the working medium to the cylinders so that the pressure at each lifting device is almost identical.

[0044] In a hydraulic system where hydraulic fluid is used as the working medium to transmit force, the automatic equalization of pressure forces can be implemented, for example, through appropriate connections of the hydraulic lines according to the principle of hydrostatic balancing. Suitable distributors and / or valves can also be used. The pressure on the pistons in the cylinders of the respective lifting device can thus be distributed evenly.

[0045] In one embodiment, the drive system of the lifting devices comprises electric motors, sensors and a control unit which is set up to control the electric motors on the basis of measured values ​​determined by the sensors, in particular for pressure and / or force, in such a way that the automatic compensation of the pressure forces is implemented.

[0046] The device can include electric motors connected to spindle drives. These electric motors can be precisely controlled by the control unit to rotate the spindles and thus control the lifting motion of the lifting devices. The sensors can continuously acquire measurements such as pressure and / or force and transmit them to the control unit. Based on these measurements, the control unit can control the electric motors to ensure smooth and controlled movement of the lifting devices. The sensors can be, for example, torque and / or force sensors attached to the electric motors and / or spindle drives to enable precise control of the lifting motion.

[0047] Preferably, the device can be designed such that the control unit is able to react to changes in the measured values ​​in real time. This enables adaptive control of the electric motors, thereby implementing the automatic compensation of compressive forces. An advantage of this embodiment is the high precision and flexibility achieved through the use of electric motors and sensors. This allows for an efficient and safe solution for pulling out beams, particularly in situations where precise control of the lifting movement is required. The control unit can be programmed to automatically adapt the lifting movement of the lifting devices to the specific conditions of the construction site, thus reducing manual effort and increasing the efficiency of the pulling process.

[0048] The lifting mechanisms are each rotatably mounted to the base plate and the housing. This rotatable mounting ensures that the housing can tilt relative to the base plate when the support is installed at an angle in the ground. This guarantees optimal force distribution during the extension process.

[0049] In one embodiment, the first axes and the second axes are identical axes, in particular horizontal axes.

[0050] In one embodiment, the lifting mechanisms are connected to the base plate and / or the housing via spherical bearings. These spherical bearings allow free movement of the housing in various directions without compromising the structural integrity of the device. This enables the housing to automatically follow the orientation of the support and adapt to its tilt angle. The spherical bearings can be equipped with damping elements that absorb vibrations and shocks to ensure smooth and controlled movement of the housing.

[0051] In one embodiment, the lifting devices are connected to the base plate and / or the housing via ball joints that allow rotation in two orthogonal directions. Preferably, the two orthogonal directions lie in a horizontal plane. Ball bearings or spherical bearings can advantageously be used as ball joints.

[0052] The rotatable bearings of the lifting devices can also be combined, for example a bearing rotatable around one axis on the housing and a bearing rotatable around two or more axes on the base plate.

[0053] To extract the beam from the ground, it is secured in the working position between clamping jaws by the clamping devices. The clamping jaws can engage various surfaces of the beam to clamp it securely. Depending on the beam's profile, the clamping jaws can, for example, engage a web, a flange, a top flange, or a bottom flange. A web is the vertical part of the beam that connects the two flanges. The clamping jaws can, for example, be positioned on opposite sides of the web, thus ensuring a secure hold. A flange is the horizontal part of the beam located at the ends of the web. The clamping jaws can, for example, engage the flanges to clamp the beam securely.For beams with an H or I profile, for example, the clamping jaws can also be attached to the top and bottom flanges to achieve a secure hold. The targeted design and placement of the clamping jaws on these surfaces ensures a secure and stable fixation of the beam, preventing slippage or twisting.

[0054] The clamping jaws are preferably designed to securely fix the support. This can be achieved, for example, through a special shape and material selection of the clamping jaws that generate high frictional force and thus prevent the support from slipping. The clamping jaws can have various designs to securely fix the support. One possible design is the use of serrated or grooved surfaces on the clamping jaws that engage with the support and thus ensure a secure hold.

[0055] In one embodiment, the clamping device is designed to operate on the principle of self-locking. This can be achieved, for example, by applying a clamping force to the carrier at the beginning of the extension process. This force creates grooves in the carrier's surfaces where the clamping jaws engage, causing the jaws to interlock with the carrier. Lifting the carrier by the lifting mechanism then causes the clamping jaws to self-lock, eliminating the need for any further active force to be applied by the clamping device.

[0056] In one embodiment, at least one clamping device has a piston, one end of which is rotatably mounted on the housing and the other end of which is rotatably mounted on a hinge plate, and the clamping jaw of the clamping device is rotatably mounted on the hinge plate.

[0057] In one embodiment, the clamping device is configured such that the lower end of the clamping jaws has a distance of 35 cm to 45 cm from the base plate in the rest state.

[0058] In some applications, the beams to be pulled out are buried deep in the ground, making it impossible to grip the beam directly with the clamping device. In such cases, it is preferred that a clamping board be detachably attached to the beam as an auxiliary device. In one embodiment, the clamping board comprises a tab or a double tab at at least one end through which a bolt can be inserted. The bolt can be positively connected to a beam to be pulled by inserting the bolt through a hole located at the upper end of the beam. The clamping board extends the beam upwards sufficiently so that the clamping jaws can grip the upper end of the clamping board. Once the beam has been pulled far enough out of the ground by the device for the clamping jaws to engage the beam directly, the clamping board can be removed.The clipboard should preferably have a non-slip surface, for example with a ribbed surface.

[0059] In one embodiment, an enclosure is attached to the base plate, at least partially enclosing the housing, with the inner diameter of the enclosure being larger than the outer diameter of the housing. An enclosure offers several advantages. Firstly, it protects the housing and the clamping devices within it from external influences. Secondly, the enclosure defines the space within which the housing can move, thus guiding its movement.

[0060] The enclosure can be made of various materials, such as steel, aluminum, other metals, or high-strength plastic. Preferably, the enclosure is made of steel. The enclosure can be a single piece or multi-piece. It can be continuous in the circumferential direction or have interruptions. The enclosure can be provided with additional reinforcements to increase its structural integrity. These reinforcements can be in the form of ribs or struts, which may be attached, for example, to the sides or corners of the enclosure. The reinforcements can also extend to and be connected to the base plate. The enclosure can be equipped with fastening points or eyelets to securely anchor or transport the device.

[0061] The enclosure can be designed in different shapes and dimensions. Preferably, the inner shape of the enclosure is adapted to the outer shape of the housing.

[0062] In one embodiment, the ratio of the inner diameter of the enclosure to the outer diameter of the housing is from 1.01 to 1.2, preferably from 1.01 to 1.06. Such dimensions have the advantage that the housing has sufficient clearance within the enclosure to move flexibly, while at the same time ensuring adequate guidance of the housing within the enclosure.

[0063] In one embodiment, the enclosure and housing are dimensioned such that the longitudinal axis of the housing can be tilted up to 15° relative to the longitudinal axis of the enclosure. Particularly when pulling out beams that are embedded at an angle in the ground, the ability to tilt the housing relative to the enclosure in different directions is advantageous, allowing it to adapt optimally to the conditions of the construction site. This reduces the risk of damage to the device and the beams being pulled out, and increases the safety of the operating personnel.

[0064] In one embodiment, the housing has rollers at least on the sides of the clamping devices, which project at least partially into the interior of the housing. The provision of rollers has the advantage that the housing can slide along the rollers during its vertical movement relative to the housing, thus only contacting the inside of the housing at specific points. This reduces friction and facilitates the movement of the housing within the housing.

[0065] Preferably, the rollers are arranged to ensure an even distribution of the loads and prevent the housing from tilting within the enclosure. The point contact of the housing with the rollers minimizes the risk of damage to the inside of the enclosure, as the contact points are reduced and the forces are distributed evenly. The rollers are preferably made of materials with high wear resistance and low friction, such as hardened steel or special plastics. This increases the service life of the rollers and ensures smooth operation of the device over a longer period.

[0066] In one embodiment, the housing has an opening in at least one side wall, the area of ​​which is at least one-quarter of the area of ​​the side wall. Preferably, the area of ​​the opening is at least one-third of the area of ​​the side wall, and more preferably, at least half of the area of ​​the side wall. Preferably, the housing has a corresponding opening on two opposite sides. In one embodiment, the enclosure has an opening in at least one side wall, the area of ​​which is at least one-quarter of the area of ​​the side wall. Preferably, the area of ​​the opening is at least one-third of the area of ​​the side wall, and more preferably, at least half of the area of ​​the side wall. Preferably, the enclosure has a corresponding opening on two opposite sides. In one embodiment, both the housing and the enclosure have a corresponding opening in at least one side wall.Preferably, in this case, the openings are located on the same side. A device with such openings has the advantage that the interior of the device, in particular the clamping mechanism, is accessible from the outside and can be easily cleaned or maintained. A further advantage is that the recesses in the side walls save material, thus keeping the mass of the device as low as possible.

[0067] In one embodiment, the device further comprises a die arranged on the underside of the base plate. The die has a recess adapted to the contour of the carrier to be pulled out. A die adapted to the contour of the carrier to be pulled out has the advantage that any soil material adhering to the carrier is wiped off on the die, thus protecting the device from contamination. The die can be one-piece or multi-piece. It can be designed for a specific type of carrier or be variably adjustable so that it can be used for several different types of carriers. Preferably, the die is designed as a plate with flat surfaces. The surfaces can be smooth or have a contour or coating, for example, for slip resistance. The die can be placed loosely under the base plate or be locked to the base plate.Preferably, the die is made of the same or a similar material as the base plate, preferably structural steel.

[0068] In one embodiment, the device has one or more features that facilitate its transport. Preferably, these features enable the device to be transported by crane, for example, eyelets for attaching a crane hook. The features can be provided, for example, in the base plate and / or the housing. Brief description of the drawings

[0069] Further details and features of the invention will become apparent from the following description of preferred embodiments, particularly in conjunction with the dependent claims. The respective features can be implemented individually or in combination with one another. The invention is not limited to these embodiments. The embodiments are shown schematically in the drawings. The drawings are to be understood as schematic representations. They do not constitute a limitation of the invention, for example, with regard to specific dimensions or design variants, unless otherwise stated in the description of the drawings. Identical reference numerals in the individual drawings denote identical or functionally equivalent elements, or elements corresponding to one another with respect to their functions.The reference numerals in all claims have no limiting effect, but are intended only to improve their readability.

[0070] They show schematically: Fig. 1 a three-dimensional view of an embodiment of a device according to the invention: Fig. 2 the device according to Fig. 1 in the top view; Fig. 3 a cutaway view of the device according to Fig. 1 at the beginning of the withdrawal procedure; Fig. 4 a cutaway view of the device according to Fig. 1 during the withdrawal procedure; Fig. 5 a cutaway view of the device according to Fig. 1 during the withdrawal process in an inclined position. Detailed description of embodiments of the invention

[0071] Fig. Figure 1 shows a three-dimensional view of an embodiment of a device according to the invention for pulling out supports 10 from the ground. Fig. 2 shows the in Fig. 1 Device shown in top view.

[0072] The device comprises a base plate 20 with a central opening 21. The base plate 20 has a rectangular shape, and the opening 21 is square. The clear dimension of the opening 21 is larger than the maximum diameter of the support 10, which is to be pulled out of the ground through the opening 21.

[0073] A housing 30 is arranged above the opening 21, having four laterally connected walls. The cross-section of the housing 30 is rectangular, with the shorter side having approximately the dimensions of the central opening 21, and the longer side being approximately 1.4 times the length of the shorter side. The opposite walls of the shorter sides are closed, while the two opposite walls of the longer sides have openings that provide access to the clamping devices from the outside through the housing. The area of ​​the openings is approximately 60% of the total area of ​​the respective side wall. The housing 30 is open at the top and bottom. A clamping device 31 is attached to each of the inner walls of the closed shorter sides, which are described below with reference to the Fig. 3 and Fig. 4 are described in more detail.

[0074] The device further comprises two lifting devices 40, which are arranged on opposite sides next to the shorter sides of the housing 30. Each lifting device 40 has a piston 44, which is slidably mounted in a cylinder 43. The cylinders 43 are attached to the base plate 20 via pivot joints and are rotatable about at least a first axis 41. The pistons 44 are rotatably mounted at the upper end of the outer surface of the shorter sides of the housing 30 about at least a second axis 42 via pivot joints. In the illustrated example, the pivot joints are designed as hinge eyes, which allow the cylinders 43 and pistons 44 to rotate about two orthogonal axes in the horizontal plane, so that the lifting devices 40 can tilt in different spatial directions.

[0075] The cylinders 43 of the lifting devices are fluidically connected to a hydraulic system and are driven by pressurized hydraulic fluid. The hydraulic system is connected according to the principle of hydrostatic balancing.

[0076] The fluid flow is controlled via appropriate control elements to ensure automatic compensation of the pressure forces. For example, if the pressure in a cylinder increases during operation, e.g., because the beam 10 being pulled is tilted, less hydraulic fluid is automatically directed to that cylinder, thus reducing the pressure. The even distribution of the pressure forces across the two lifting devices 40 enables the beam 10 to be pulled out of the ground smoothly.

[0077] The Fig. 3, Fig. 4 to Fig. Figure 5 shows a cutaway view of the device described above, in which the front of the housing 30 and the enclosure 50 are not visible. Fig. 3 corresponds to the state at the beginning of the withdrawal process. Fig. Figure 4 shows the state during the extraction process, in which the housing 30 is raised relative to the base plate 20. Fig. Figure 5 shows the device in a state in which the housing 30 is tilted relative to the base plate 20 and the enclosure 50.

[0078] A clamping device 31 is mounted on each of the shorter walls of the housing 30, and these devices are movable between a rest position and a working position. Each clamping device 31 has a piston 33, one end of which is rotatably mounted on the housing 30 and the other end of which is rotatably mounted on a hinge plate 34. The hinge plate 34 is also rotatably mounted about a lower pivot point on the inner sides of the shorter walls of the housing 30. A clamping jaw 32 is rotatably mounted on each of the two hinge plates 34.

[0079] The clamping jaws face each other with their outer surfaces, so that they can clamp a surface of the beam 10 to be pulled between them. Their opposing surfaces are provided with a serration which ensures good adhesion of the clamping jaws 32 to the beam surfaces when pressed down and prevents the beam 10 from slipping.

[0080] In the rest position, the pistons 44 are retracted into the cylinders 43, and the clamping jaws 32 rest at their lowest point. As soon as the lifting cylinders 33 of the clamping devices 31 are pressurized, the clamping jaws 32 approach the surfaces of the beam 10 until they touch. Once sufficient pressure is applied to prevent the clamping jaws 32 from slipping off the beam surface, the pressure in the cylinders 43 of the lifting devices 40 is increased, causing the pistons 44 to extend upwards. This causes the beam 10 to automatically self-lock in the clamping jaws 32, thereby pulling the beam 10 upwards out of the ground with increasing pressure in the cylinders 43. Once the beam has been pulled sufficiently far out of the ground, it can be picked up by a crane for removal.

[0081] The device further comprises an enclosure 50, which surrounds the housing 30 and is attached to the base plate 20. The enclosure 50 includes four laterally connected walls. In cross-section, the enclosure 50 is rectangular and corresponds to the cross-sectional shape of the housing 30. The walls are dimensioned such that the ratio of the inner diameter of the enclosure 50 to the outer diameter of the housing 30 in the rest state with the housing centered is approximately 1.05. The opposing walls of the shorter sides are closed, while the two opposing walls of the longer sides have openings that provide access to the clamping devices from the outside through the enclosure. The area of ​​the openings is approximately 30% of the total area of ​​the respective side wall. The enclosure 50 is open at the top.

[0082] The gap between the inside of the enclosure 50 and the outside of the housing 30 allows the housing 30 to move freely within the enclosure 50. If the support 10 is inclined in the ground, the lifting devices 40 adjust themselves due to pressure equalization so that the cylinders and pistons assume approximately the same inclination as the support. This also tilts the housing 30 relative to the base plate 20 and the enclosure 50. The free space within the enclosure 50 limits the movement of the housing 30. In the device shown in the example, the dimensions of the housing and enclosure allow for an inclination of approximately 15° of the longitudinal axis of the housing (LG) relative to the longitudinal axis of the enclosure (LE).

[0083] The enclosure 50 has rollers 51 at each end of its sides, some of which project into the interior of the enclosure 50. The rollers 51 are mounted at a distance from the corners of the enclosure. A first row of eight rollers 51 is mounted at a distance from the base plate 20. Above this, a second row of eight rollers 51 is mounted at a distance from the first row. During vertical movement of the enclosure 30, its outer surface can abut the rollers 51 and slide along them. Reference symbol list 10 screws 10 carriers 20 Base plate 21 Opening the base plate 30 cases 31 clamping devices 32 clamping jaws 33 pistons 34 Joint plate 40 lifting device 41 first axis 42 second axis 43 cylinders 44 pistons 50 Enclosure 51 rolls 52 Support brace LE Longitudinal axis of the enclosure LG Longitudinal axis of the housing QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2016 100 311 U1

[0008] DE 20 2017 104 471 U1

[0009] DE 20 2020 100 504 U1

[0010]

Claims

A device for extracting beams (10) from the ground, comprising a base plate (20) with an opening (21) for placing on the ground around the beam (10) to be extracted, and a housing (30) arranged above the opening (21) of the base plate, open upwards and downwards, in which at least two clamping devices (31) with clamping jaws (32) are arranged on opposite sides, which are movable between a rest position and a working position, wherein the clamping devices (31) secure the beam (10) between the clamping jaws (32) in the working position and release the beam (10) in the rest position, characterized in that the device has at least two lifting devices (40) with drive, each of which is rotatably attached at its lower end to the base plate (10) about at least a first axis (41) and rotatably attached at its upper end to the housing (30) about at least a second axis (42),wherein the drives of the lifting devices (40) are configured such that a compensation of the pressure forces on the lifting devices (40) is automatically achieved during operation of the device. Device according to claim 1, characterized in that the lifting devices (40) each have a piston (44) that is displaceable in a cylinder (43), and the drive system is a pneumatic system or a hydraulic system in which the automatic compensation of the pressure forces is implemented by the interconnection of the fluid flows and / or by control elements for influencing the fluid flow. Device according to one of the preceding claims, characterized in that at least one clamping device (31) has a reciprocating piston (33) of which one end is rotatably mounted on the housing (30) and the other end is rotatably mounted on a hinge plate (34), and the clamping jaw (32) of the clamping device (31) is rotatably mounted on the hinge plate (34). Device according to one of the preceding claims, characterized in that the clamping device (31) is configured such that the lower end of the clamping jaws (32) has a distance from the base plate (10) of 35 cm to 45 cm in the rest state. Device according to one of the preceding claims, characterized in that an enclosure (50) is attached to the base plate (10), which at least partially encloses the housing (30), wherein the inner diameter of the enclosure (50) is larger than the outer diameter of the housing (30). Device according to claim 5, characterized in that the ratio of the inner diameter of the enclosure (50) to the outer diameter of the housing (30) is from 1.01 to 1.2, preferably from 1.01 to 1.

06. Device according to claim 5 or 6, characterized in that the enclosure (50) and the housing (30) are dimensioned such that the longitudinal axis of the housing (30) can be tilted up to 15° relative to the longitudinal axis of the enclosure (50). Device according to one of claims 5 to 7, characterized in that the housing (50) has rollers (51) at least on the sides of the clamping devices (31) which project at least partially into the interior of the housing (50). Device according to one of the preceding claims, characterized in that the housing (30) and / or the enclosure (50) has an opening in at least one side wall, the area of ​​which is at least one quarter of the area of ​​the side wall. Device according to one of the preceding claims, characterized in that a matrix is ​​arranged on the underside of the base plate, which has a recess adapted to the contour of the carrier to be pulled out.

Images