Lifting cushion with integrated stroke measurement

Abstract

The invention relates to a lifting bag (1) for lifting a load, wherein the lifting bag (1) is designed to be inflatable from a flat state for placing beneath the load by enlarging an internal volume (2) enclosed by the lifting bag (1) into an inflated state for lifting the load. The lifting bag (1) has a first wall (3) with a first lifting surface (4) facing the load and with a first lifting bag inner surface (5) facing the internal volume (2). A second wall (6) of similar design is arranged opposite the first wall (3). The invention is characterized in that the lifting bag (1) comprises a measuring device (10) with a distance sensor (11) for determining a stroke of the lifting bag (1), wherein a distance between the first lifting bag inner surface (5) and the second lifting bag inner surface (8) is detected to determine the stroke.

Description

[0001] The invention relates to a lifting cushion for lifting a load, wherein the lifting cushion is designed to be inflatable from a flat state for placing under the load to an inflated state for lifting the load.

[0002] A transportable lifting device is known from US 2014 / 0183430 A1. The lifting device comprises a hydrogen gas supply unit for providing hydrogen gas absorbed in a hydrogen storage alloy by heating the hydrogen storage alloy with a heat source, and an actuating unit that expands due to the pressure of the hydrogen gas supplied by the hydrogen gas supply unit in order to lift an object. The disclosure of this document constitutes the preamble of claim 1.

[0003] Furthermore, lifting cushions for lifting a load above a surface are well known in the art. They have a variable internal volume, which can be significantly increased by filling them with a pressure medium, such as compressed air. By increasing the internal volume, loads resting on the lifting cushion can be lifted. Such lifting cushions are generally constructed so that a bladder made of vulcanized rubber material encloses the variable internal volume. The bladder can be protected from the external environment by a reinforcing layer. To fill the lifting cushion with a pressure medium, a valve connection is also provided, which allows a continuous connection from the environment to the variable internal volume of the bladder for inflating the lifting cushion with air or deflating it.

[0004] Depending on their size, lifting cushions are capable of lifting loads of several tons over several decimeters or meters. These cushions can be used to lift vehicles, machinery, concrete components, building debris, and similar items. To lift a load, a lifting cushion is placed flat and uninflated beneath it and then typically inflated with compressed air. As it inflates, the cushion expands, increasing in height and thickness. Once the lifting cushion makes contact with the load, it lifts it. This change in thickness and height during inflation can also be referred to as the lifting cushion's lift.

[0005] Lifting cushions can also be used to lift loads at an angle, move them laterally, or spread components apart. Practical applications include lifting vehicles, lifting components of collapsed buildings, especially concrete parts, or moving loads laterally, as well as spreading jammed vehicle doors or vehicle parts after accidents. The angled lifting, lateral movement, or spreading is analogous to the lifting of a load in a vertical direction, which is the primary application described, so that the lifting of the load in this application is always to be understood as representative of the other applications as well.

[0006] When the lifting cushion is inflated, two opposing curved walls typically form, depending on the cushion's design. One of the two walls curves outwards towards the load, and the other wall curves outwards towards the ground.

[0007] Due to its two curved walls, the lifting cushion deforms during inflation from its flat state towards a round or spherical shape. Monitoring this inflation process requires considering both the pressure within the lifting cushion and its height, or stroke. If the pressure becomes too high, the lifting cushion can tear or burst. If the height of the lifting cushion becomes too great, it can become too rounded and potentially roll out under the load. Furthermore, pressure and stroke are interdependent, allowing conclusions to be drawn about the condition and load of the lifting cushion based on these two parameters.

[0008] The stroke can be of particular interest when the lifting of the load needs to be closely monitored. For example, if a load is only to be supported and not lifted, or if the load is to be lifted slowly and in a controlled manner by a specific stroke.

[0009] Up to now, the stroke of lifting cushions when lifting loads has only been recorded manually, for example by repeated manual measurements with a measuring stick between the surface and the load. Such measurements are very inaccurate and cumbersome to perform.

[0010] Therefore, the object of the invention is to provide a lifting cushion and a method which optimizes the determination of the lifting cushion's stroke.

[0011] This problem is solved by the objects and methods with the features of the independent claims. Further, particularly advantageous embodiments of the invention are disclosed in the respective dependent claims and the following description.

[0012] It should be noted that the features listed individually in the claims can be combined with one another in any technically meaningful way (even across category boundaries, for example between method and apparatus) and demonstrate further embodiments of the invention. The description further characterizes and specifies the invention, particularly in conjunction with the figures.

[0013] It should also be noted that the conjunction "and / or" used herein, which stands between two features and links them together, is always to be interpreted in such a way that in a first embodiment of the object according to the invention only the first feature may be present, in a second embodiment only the second feature may be present, and in a third embodiment both the first and the second feature may be present.

[0014] According to the present invention, the lifting cushion is designed for lifting a load, wherein the lifting cushion can be inflated from a flat state for placing under the load by increasing the volume of its enclosed interior to an inflated state for lifting the load. The lifting cushion has a first wall with a first lifting surface facing the load and a first inner surface facing the interior volume. The lifting cushion also has a second wall opposite the first wall, with a second lifting surface facing away from the load and a second inner surface facing the interior volume.The lifting cushion is characterized by having a measuring device with a distance sensor for determining a stroke of the lifting cushion, wherein the measuring device is arranged in such a way that a distance between the first inner surface of the lifting cushion and the second inner surface of the lifting cushion is detected by the distance sensor to determine the stroke.

[0015] The lifting cushion has a variable internal volume that can be filled with a pressure medium, in particular compressed air, to increase this volume. The lifting cushion is designed for lifting loads. For this purpose, the lifting cushion may include a bladder that encloses the variable internal volume. In particular, the bladder is made of vulcanized rubber or homogeneous raw rubber.

[0016] The bladder can be surrounded by a reinforcing layer, which is arranged around the inner bladder in the direction of its environment. This environment includes, for example, the substrate and the load. The reinforcing layer can serve two purposes: firstly, to protect the bladder from damage caused by contact with the load or the substrate, and secondly, to strengthen the bladder so that it can, for example, withstand higher pressures and heavier loads.

[0017] It may be provided that the reinforcing layer and the inner blister are bonded together by material adhesion, in particular that they are vulcanized together.

[0018] It can be designed so that the reinforcing layer is integrated into the bladder, eliminating the need for a separate inner bladder. In other words, the bladder is reinforced by an integrated reinforcing layer.

[0019] The reinforcing layer can be designed as a fabric layer, for example made of Kevlar.

[0020] The lifting cushion is placed under the load in a flat state, either uninflated or only partially inflated. Whether or how much the cushion is inflated is of secondary importance. When placed under the load, the cushion simply needs to be flat enough to fit into a gap or space between the load and the ground. After being placed under the load, the lifting cushion is then inflated or further inflated.

[0021] When the lifting cushion is not inflated, it is in a deflated state, also known as its ground state or flat state. In this deflated state, the lifting cushion can be shaped like a flat cuboid, a flat cube, a flat prism, or a flat cylinder, each with a small height. In this context, "small height" or "flat" means that the height is significantly smaller than the other dimensions of the lifting cushion, such as its width, length, or diameter. With a cuboid ground shape in its deflated state, the cross-section of the lifting cushion when inflated can be elliptical or circular. In this case, the cross-section would, for example, pass through a minimum diameter of the lifting cushion when inflated.

[0022] When the lifting cushion is inflated, two opposing curved walls form. The first of the two walls bulges outwards towards the load, forming a convex lifting surface facing the load. The other side of the first wall faces the inner volume and is concave.

[0023] The second wall of the lifting cushion is convex, bulging outwards towards the ground and forming a convex lifting surface facing away from the load. The other side of the second wall faces the interior volume and is concave.

[0024] Due to the two curved walls, the lifting cushion deforms during inflation, starting from its flat state and moving towards a round or spherical state.

[0025] The two walls are essentially formed from a flexible material, such as rubber, so that the lifting cushion can inflate and deform accordingly. However, the walls can also include areas of rigid material, such as the flanges described later in the application.

[0026] Depending on their size, lifting cushions can lift loads of varying heights. Practical tests have shown that a lifting cushion with a square base (i.e., when deflated) measuring 14 cm wide and 14 cm long can lift a load of approximately 1.3 tons. A cushion measuring 32 cm wide and 32 cm long can lift approximately 10 tons, a cushion measuring 61 cm approximately 40 tons, a cushion measuring 86 cm approximately 80 tons, and a cushion measuring 95 cm approximately 100 tons. These dimensions correspond in order of magnitude to the typical sizes of the lifting cushions discussed here, as well as to the typical loads that can be lifted.

[0027] Essential to the invention is that the lifting cushion includes a measuring device with which the stroke of the lifting cushion can be determined. For this purpose, the measuring device has a distance sensor configured to detect the distance between the first inner surface of the lifting cushion and the second inner surface of the lifting cushion. Using the distance between the two inner surfaces of the lifting cushion, the stroke and / or the height of the lifting cushion can then be determined.

[0028] The distance sensor is positioned either on the first or second inner surface of the lifting cushion. The distance is measured from the sensor to the opposite inner surface. The sensor can be located on the surface of the lifting cushion or integrated into it or one of its walls. In particular, the sensor can be integrated flush with the surface of the lifting cushion.

[0029] In principle, the distance sensor can be positioned anywhere on the inner surface of the lifting cushion. However, it is particularly advantageous to position the distance sensor centrally, i.e., in the geometric center of one of the inner surfaces of the lifting cushion, and to measure the distance to the geometric center of the opposite inner surface.

[0030] The height of the lifting cushion can be determined by the distance between its two lifting surfaces, preferably by the distance between the two apexes of the convex lifting surfaces, or the distance between the two apexes of the concave inner surfaces of the lifting cushion. Alternatively, the height of the lifting cushion can also be determined by the distance between the load and the ground.

[0031] The lifting cushion's stroke is the difference between the actual height of the lifting cushion and a reference height. The reference height could be, for example, a minimum height of the lifting cushion, or a height at a specific point in time, such as at the start of inflation, at the beginning of lifting the load, or at the moment the lifting cushion first makes contact with the load.

[0032] The height of the lifting cushion can be determined directly by the sensor directly detecting or outputting the height of the lifting cushion.

[0033] The height can also be determined indirectly. This means that the distance measured by the distance sensor must be converted into the height of the lifting cushion. For example, if the distance sensor measures the distance between the two vertices of the concave inner surfaces of the lifting cushion, the height can be calculated by adding the thicknesses of the cushion walls.

[0034] If the distance between the two inner surfaces of the lifting cushions is detected by the sensor at a location other than the vertices, the distance between the vertices can be determined, for example, by extrapolating the detected distance.

[0035] It is also possible to determine the stroke directly by simply detecting the change in distance between the inner surfaces of the lifting cushions using the distance sensor. For this purpose, the distance sensor can establish a reference value for the distance at any given time (for example, at the start of lifting the load, when the lifting cushion is flat, or when the measuring device is switched on), and then output only the change in distance relative to this reference value. In other words, the distance detected by the distance sensor can be zeroed at any time, so that subsequently only the change in distance is recorded, and this change then corresponds to the stroke.

[0036] If the distance is measured between the vertices of the concave inner surfaces, the measured change in distance generally corresponds directly to the stroke of the lifting cushion. If the distance is measured at a different point on the inner surfaces of the lifting cushion, the measured distance can be extrapolated and / or converted to obtain the change in distance between the vertices of the inner surfaces of the lifting cushion, i.e., the stroke.

[0037] Advantageous embodiments and variants of the invention are described in the dependent claims and the following description. The features listed individually in the dependent claims can be combined with each other and with the features explained in more detail in the following description in any technically sensible manner, and represent other advantageous embodiments of the invention.

[0038] In one embodiment of the lifting cushion, the distance sensor is designed as a radar distance sensor, an optical distance sensor, an inductive distance sensor, or an ultrasonic distance sensor.

[0039] Optical distance sensors can use laser beams for measurement.

[0040] In a further embodiment of the lifting cushion, the measuring device includes an energy storage device, in particular a rechargeable energy storage device, for supplying power to the distance sensor. The measuring device and the distance sensor require electrical energy. This energy can be supplied by an energy storage device located within the lifting cushion. The energy storage device can be a battery or a rechargeable accumulator. The energy storage device can be replaceable or permanently connected to the measuring device or the lifting cushion. Such an integrated energy storage device within the lifting cushion has the advantage that the lifting cushion does not need to be connected to an external electrical power source.

[0041] It is advantageous if the energy storage device is rechargeable so that it does not need to be replaced when it is depleted. Therefore, the lifting cushion features an electrical connection socket for recharging the rechargeable energy storage device.

[0042] Alternatively or additionally, the measuring device can be powered directly via the electrical connection socket. With direct power supply, the energy storage device can be omitted or only used when needed, i.e., when no external electrical power is supplied via the connection socket.

[0043] In a further embodiment of the lifting cushion, the measuring device includes an acceleration sensor that detects any acceleration acting on the measuring device. Such a sensor can be used for further analysis of the condition of the lifting cushion.

[0044] In a further embodiment of the lifting cushion, the measuring device includes a pressure sensor that detects the pressure within the cushion's internal volume. As mentioned earlier, the pressure and the lifting cushion's stroke are directly related. Generally, the higher the pressure, the greater the lifting cushion's stroke. The load's height also directly influences the pressure and stroke of the lifting cushion. The heavier the load, the higher the pressure within the lifting cushion and the shorter the stroke. Therefore, the condition of the lifting cushion can be determined more precisely using a pressure sensor. Furthermore, the pressure within the lifting cushion, as measured by the pressure sensor, combined with the cushion's stroke and height, allows conclusions to be drawn about the load's height.

[0045] In a further embodiment of the lifting cushion, the measuring device includes a temperature sensor that records the temperature within the cushion's internal volume. This temperature allows for a better assessment of the compressed air's condition within the cushion, as pressure and temperature are directly related in gases. For example, the temperature within the lifting cushion can indicate whether the compressed air is compressing or expanding too quickly.

[0046] In a further embodiment of the lifting cushion, the measuring device includes an altitude sensor that detects the height of the device above sea level. Such an altitude sensor can, for example, detect the ambient pressure of the lifting cushion, i.e., the atmospheric pressure, and thus determine the height of the measuring device above sea level. The altitude above sea level, in turn, allows conclusions to be drawn about the air density, enabling the inflation process of the lifting cushion to be optimized. For example, the power of a compressor used to inflate the lifting cushion can be adjusted according to the altitude above sea level.

[0047] In a further embodiment of the lifting cushion, the measuring device includes an inclination sensor that detects the inclination of the measuring device. The inclination of the lifting cushion can be, for example, the inclination of a reference surface of the lifting cushion relative to a vertical, or the inclination of a centerline of the lifting cushion relative to a vertical, or the inclination of an axis of symmetry of the lifting cushion relative to a vertical. In this way, the absolute inclination of the lifting cushion can be determined.

[0048] It is also conceivable that the inclination is measured not relative to a vertical, but relative to a normal of the ground. In this way, the inclination of the lifting cushion relative to the ground can be determined.

[0049] In another embodiment of the lifting cushion, the distance sensor is attached to either the first or the second inner surface of the lifting cushion. The distance sensor can be flush-mounted in one of the inner surfaces or mounted on top of it. Starting from the surface to which it is attached, the distance sensor then measures the distance to the opposite inner surface. Directly attaching the distance sensor to one of the inner surfaces has the advantage that it directly follows the movements and deformations of that surface, thus enabling a very precise determination of the distance to the opposite inner surface.

[0050] In a further embodiment of the lifting cushion, the first inner surface of the lifting cushion or the second inner surface of the lifting cushion includes a reference surface, with the help of which the distance sensor determines the distance between the first inner surface of the lifting cushion and the second inner surface of the lifting cushion.

[0051] Depending on the measuring principle used by the distance sensor, such a reference surface can improve the measurement. For example, the reference surface can be flat.

[0052] It is also conceivable that the reference surface has a reflective surface corresponding to the measuring principle of the distance sensor. In particular, a corresponding color and / or surface structure of the reference surface can improve the measurement of the distance sensor.

[0053] The reference surface is located, in particular, on the inner surface of the lifting cushion, which is positioned opposite the inner surface of the lifting cushion with the distance sensor.

[0054] In a further embodiment of the lifting cushion, a measuring housing containing the measuring device is connected to the first or second inner surface of the lifting cushion. The measuring housing is designed to accommodate the individual components of the measuring device, such as the distance sensor and the energy storage device.

[0055] The measuring housing is specifically designed to protect the measuring device from mechanical damage. For example, the measuring device could become trapped between the two inner surfaces of the lifting cushions if the lifting cushion is in its flat position, or if the load is too heavy and the inner surfaces of the lifting cushions are in contact. In these cases, the measuring housing protects the measuring device from unwanted mechanical impacts.

[0056] In particular, the measuring housing is centrally attached to the first or second inner surface of the lifting cushion. "Centrally" in this context means that the measuring housing is located, for example, at the geometric center of the inner surface of the lifting cushion, or at the apex of the concave inner surface of the lifting cushion.

[0057] In a further embodiment of the lifting cushion, the first wall comprises an integrated first flange. Preferably, a first outer flange surface of the first flange forms part of the first lifting surface. More preferably, a first inner flange surface of the first flange forms part of the first inner surface of the lifting cushion.

[0058] Alternatively or additionally, the second wall has an integrated second flange. Preferably, a second flange outer surface forms part of the second lifting surface. More preferably, a second flange inner surface forms part of the second lifting cushion inner surface.

[0059] The flanges are therefore integrated into the respective wall of the lifting cushion, so that the respective flange outer sides and flange inner sides are aligned with the lifting surfaces and the lifting cushion inner surfaces.

[0060] The distance between the two inner surfaces of a lifting cushion with two flanges can be determined between the two flange inner surfaces, particularly if the two flange inner surfaces are arranged parallel to each other. The first flange inner surface can therefore be positioned opposite and parallel to the second flange inner surface within the lifting cushion.

[0061] The flanges are designed as solid components, for example, made of metal, aluminum, or plastic. The flanges can improve the connection of the lifting cushion to the load and the ground by providing a firm and, in particular, flat contact surface for the load and the ground.

[0062] In a further embodiment of the lifting cushion, the first or second flange includes a measuring receptacle for the measuring device, with the measuring device being arranged within the measuring receptacle. Arranging the measuring device in one of the flanges is advantageous because these are designed as solid bodies, thus facilitating the easy attachment of the measuring device to or within the flanges.

[0063] The measuring device can be designed as a recess in the flange, so that the measuring device, and in particular the distance sensor, does not protrude beyond the inner surface of the lifting cushion. This prevents mechanical damage to the measuring device when the inner surfaces of the lifting cushions are in contact with each other, for example, when the lifting cushion is flat.

[0064] In another embodiment of the lifting cushion, the measuring housing with the measuring device is arranged on the first or second inner flange surface. Such an arrangement is advantageous because attaching the measuring housing to one of the flanges is significantly easier than attaching it to the otherwise flexible wall of the lifting cushion.

[0065] The reference surface can also be designed as part of the first flange's inner surface or as part of the second flange's inner surface. Such an arrangement is particularly suitable when the distance sensor detects the distance between the two flange's inner surfaces.

[0066] In a further embodiment of the lifting cushion, the first inner flange surface is arranged centrally to the first inner surface of the lifting cushion, and / or the second inner flange surface is arranged centrally to the second inner surface of the lifting cushion. In this context, such a central arrangement means that the respective inner flange surface is located, for example, at the geometric center of the inner surface of the lifting cushion. The inner flange surfaces can also be arranged on the centerline or axis of symmetry of the lifting cushion.

[0067] In a further embodiment of the lifting cushion, the first flange and / or the second flange has a connection receptacle for a mechanical connecting element, whereby two stacked lifting cushions can be mechanically connected to each other via flanges arranged facing each other using the mechanical connecting element.

[0068] If more than one lifting cushion is used to lift the load, the lifting cushions can be stacked on top of each other. To give such a stack of lifting cushions more stability, they can be connected to each other using mechanical connectors. For this to work, adjacent lifting cushions in the stack must each have a connecting receptacle, and these receptacles must be facing each other. The connecting receptacles facing each other can then be connected using a mechanical connector.

[0069] Such a mechanical connecting element could, for example, be a pin that can be positively connected at both ends to one of the connecting receptacles. In this way, two adjacent lifting cushions can be mechanically connected to each other via the pin.

[0070] The invention also relates to a method for determining the stroke of a lifting cushion, wherein the lifting cushion is designed to be inflated from a flat state for placing under a load by increasing an internal volume enclosed by the lifting cushion into an inflated state for lifting the load, wherein the lifting cushion has a first wall with a first inner surface of the lifting cushion facing the internal volume, and wherein the lifting cushion has a second wall arranged opposite the first wall with a second inner surface of the lifting cushion facing the internal volume.

[0071] The procedure includes at least the following steps: Changing the internal volume enclosed by the lifting cushion by inflating or deflating it with a pressure medium; measuring the distance between the first and second inner surfaces of the lifting cushion before and after the change in internal volume; determining the stroke of the lifting cushion taking into account the measured distances.

[0072] Instead of the stroke, only the height of the lifting cushion can be determined.

[0073] The present invention is explained in detail below with reference to exemplary embodiments and the accompanying figures. These show: Figure 1: A lifting cushion for lifting a load in a flat, uninflated state, with a measuring device for determining the stroke of the lifting cushion; Figure 2: The lifting cushion made of Fig. 1 in a sectional view, Figure 3 the lifting cushion made of Fig. 1In another sectional view, Figure 4 shows an enlarged section of the measuring device area. Fig. 3 Figure 5 shows another embodiment of a lifting cushion, with an alternatively arranged measuring device, Figure 6 shows another embodiment of a lifting cushion, with a reference component for the distance sensor.

[0074] In the figures, unless otherwise indicated, identical reference symbols denote identical or corresponding components with the same function.

[0075] Figure 1 Figure 1 shows a lifting cushion 1 for lifting a load in a flat state, i.e., an uninflated state. The lifting cushion 1 has a measuring device 10 arranged inside the lifting cushion 1 for determining the stroke of the lifting cushion 1, so that this is Fig. 1 is not visible.

[0076] The lifting cushion 1 can be placed in the Fig. 1The lifting cushion 1 is placed under the load in its depicted flat state. To lift the load, the lifting cushion 1 is inflated. In its flat state, the height of the lifting cushion 1 is many times less than its height when inflated.

[0077] The lifting cushion 1 encloses an internal volume 2, which can be increased by filling it with a pressure medium, such as compressed air. Increasing the internal volume 2 increases the height of the lifting cushion 1, thus enabling it to lift a load placed on top of the lifting cushion 1.

[0078] The lifting cushion 1 has a valve 9 to increase its internal volume 2, through which the pressure medium can be supplied to the lifting cushion 1. Pressure medium can also be released via the valve 9 to reduce the internal volume 2.

[0079] The supply and discharge of pressurized medium can be effected by means of a compressed air control system, which is generally located externally to the lifting cushion 1. The compressed air control system is connected to the lifting cushion 1 via a compressed air connection through valve 9. It is conceivable that the compressed air control system is connected to the measuring device 10 of the lifting cushion 1 and uses this device to adjust and / or regulate the compressed air supply.

[0080] The internal volume 2 of the lifting cushion 1 is bounded in the direction of the load by a first wall 3, and in the direction of a ground by a second wall 6 arranged opposite the first wall 3. In this case, the first wall 3 merges into the second wall 6, so that the two walls 3 and 6 enclose the internal volume 2.

[0081] However, further walls or elements can also be arranged between the first and second walls 3 and 6, which together with walls 3 and 6 enclose the inner volume. For example, the first wall 3 can be connected to the second wall 6 via a seam.

[0082] The first wall 3 and the second wall 6 are arranged along a centerline M of the lifting cushion 1. The geometric centers of walls 3 and 6 are located on the centerline M. The centerline M essentially forms an axis of rotational symmetry of the lifting cushion 1, although individual elements of the lifting cushion 1, such as carrying handles or the valve 9, do not exhibit rotational symmetry with respect to the centerline M.

[0083] The load rests on a first lifting surface 4 of the first wall 3, while the contact of the lifting cushion 1 with the ground is made via a second lifting surface 7 of the second wall 6. The first lifting surface 4 is arranged opposite the second lifting surface 7, and the lifting surfaces 4 and 7 point away from each other.

[0084] When the lifting cushion 1 is inflated, both walls 3 and 6 have a convex shape. The first wall 3 bulges outwards towards the load, and the second wall 6 bulges towards the ground. The two lifting surfaces 4 and 7 thus become convex.

[0085] To allow the two walls 3 and 6 to deform and thus increase / decrease the internal volume 2, they are at least partially flexible. The flexible parts of the walls 3 and 6 are preferably made of rubber and may be reinforced by an integrated fabric.

[0086] The lifting cushion 1 has a first flange 15 integrated into the first wall 3 and a second flange 18 integrated into the second wall 6. The first flange 15 has a first flange outer surface 16, which forms part of the first lifting surface 4. The second flange 18 has a second flange outer surface 19, which forms part of the second lifting surface 7. The flange outer surfaces 16 and 19 are each flush with the adjacent parts of the lifting surfaces 4 and 7, respectively.

[0087] Flanges 15 and 18 are each arranged centrally to their respective lifting surfaces 4 and 7. When the lifting cushion 1 is at least partially inflated, with the lifting surfaces 4 and 7 already convexly shaped, flanges 15 and 18 are each arranged at the apexes of the convexly shaped lifting surfaces 4 and 7.

[0088] The flanges 15 and 18 can each be materially bonded to the associated wall 3 and 6 respectively, for example by means of a vulcanization process, especially if part of the walls 3 and 6 are flexible and made of rubber, for example.

[0089] Flanges 15 and 18 are rigidly designed so that they do not deform when the lifting cushion 1 is inflated. This also applies to the outer flange surfaces 16 and 19, which are part of the corresponding lifting surfaces 4 and 7, so that these parts of the lifting surfaces 4 and 7 do not deform when the lifting cushion 1 is inflated, i.e., they do not become convex. Flanges 15 and 18 can be made of metal or plastic, for example, preferably aluminum.

[0090] The measuring device 10 is together with the distance sensor 11 inside the lifting cushion 1. Fig. 1 arranged so that the measuring device 10 is in the Fig. 1It is not visible. However, in the following sectional views of the lifting cushion 1, the measuring device 10 of the lifting cushion 1 is clearly visible and is explained by the Figs. 2 to 4 described in more detail.

[0091] Fig. 2 and Fig. 3 show the lifting cushion 1 from Fig. 1 each in a sectional view. Fig. 4 shows an enlarged section of the area around the measuring device 10 from the Fig. 3 . The Figs. 2 to 4 They will therefore be described together in the following sections.

[0092] The internal volume 2 of the lifting cushion 1 is clearly visible in the sectional views. The first wall 3 has a first inner surface 5, and the second wall 6 has a second inner surface 8. The first inner surface 5 transitions into the second inner surface 8. The internal volume 2 is enclosed by the two inner surfaces 5 and 8. The walls 3 and 6 are essentially flexible—except for the sections formed by the flanges 15 and 18—so that the walls 3 and 6 bulge outward when the lifting cushion 1 is inflated. The inner surfaces 5 and 8 then assume a concave shape.

[0093] The first lifting cushion inner surface 5 comprises a first flange inner surface 17 of the first flange 15, and the second lifting cushion inner surface 8 comprises a second flange inner surface 20 of the second flange 18. The flange inner surfaces 17 and 20 are each flush with the adjacent other parts of the lifting cushion inner surfaces 5 and 8.

[0094] The first inner flange surface 17 is arranged parallel to the second inner flange surface 20. This is particularly the case when the lifting cushion 1 is unloaded. If the lifting cushion 1 is loaded by lifting a load, the inner flange surfaces 17 and 20 may no longer be aligned parallel to each other, as the load can cause the first flange 15 to tilt or the first wall 3 to tilt / deform.

[0095] The measuring device 10, together with the distance sensor 11, is arranged on the first inner surface 5 of the lifting cushion. The measuring device 10 is also arranged centrally to the first inner surface 17 of the flange, and thus also centrally to the first inner surface 5 of the lifting cushion. In particular, the distance sensor 11 is arranged on the center line M and detects the distance along the center line M from the first inner surface 5 of the lifting cushion to the second inner surface 8 of the lifting cushion.

[0096] The presence of flanges 15 and 18 is not essential. For determining the stroke of the lifting cushion 1, it is only necessary that the distance sensor 11 of the measuring device 10 is arranged in a defined relative position to the first or second inner surface 5 or 8 of the lifting cushion. This can be achieved by integrating the distance sensor 11 on / in one of the inner surfaces 5 or 8 of the lifting cushion, or by integrating the distance sensor 11 in one of the walls 3 or 6, or by integrating the distance sensor 11 in one of the flanges 15 or 18, or by integrating the distance sensor 11 on / in one of the inner surfaces 17 or 20 of the flanges.

[0097] The measuring device 10 comprises a measuring housing 13 in which the distance sensor 11 is arranged. The measuring housing 13 is connected to the first flange 15 via the first inner flange surface 17, and thus, in this case, to the first inner surface 5 of the lifting cushion.

[0098] To protect the measuring housing 13, the measuring device 10, and / or the distance sensor 11, a mechanical stop (not shown in the exemplary embodiments presented here) can be provided on one or both of the flanges 15 or 18, which prevents the measuring housing 13, the measuring device 10, and / or the distance sensor 11 from being clamped between the two inner flange surfaces 17 and 20. For this purpose, the stop is designed such that the inner flange surfaces 17 and 20 are spaced apart by the stop when the lifting cushion 1 is not inflated.

[0099] However, it is also advantageous if the measuring housing 13 itself is designed to be sufficiently stable, so that no separate mechanical stop needs to be provided, since the measuring housing 13 can withstand the mechanical loads caused by being clamped between the flanges 15 and 18.

[0100] The measuring housing 13 can be made of plastic or metal, preferably of aluminium.

[0101] The distance sensor 11 is generally configured to detect the distance between the first inner surface 5 of the lifting cushion and the second inner surface 8 of the lifting cushion. In the illustrated embodiment, this distance corresponds to the distance between the first inner surface 17 of the flange and the second inner surface 20 of the flange along the center line M.

[0102] If no flanges 15 and 18 are present on the lifting cushion 1, the distance between the two vertices of the concave inner surfaces 5 and 8 of the lifting cushion can also be detected by the distance sensor 11.

[0103] It is fundamentally irrelevant whether the distance sensor 11 is arranged on the first or the second inner surface 5 or 8 of the lifting cushion, or whether it has direct contact with one of the two inner surfaces 5 or 8. What is crucial is that the distance sensor 11 is arranged relative to one of the two inner surfaces 5 or 8 of the lifting cushion and detects the distance to the opposite inner surface 5 or 8 of the lifting cushion in some way.

[0104] Depending on the measuring principle, the distance sensor 11 can emit radar beams, ultrasound, light beams, laser beams, or the like, directed at the opposite inner surface 5 or 8 of the lifting cushion, thus determining the distance between the first and second inner surfaces 5 and 8 of the lifting cushions. A measuring opening can be provided in the measuring housing 13 for this purpose, through which the distance sensor 11 has a clear measuring path without optical obstructions to the opposite inner surface 5 or 8 of the lifting cushions.

[0105] When the lifting cushion 1 is inflated, its height increases, and the distance between the first inner surface 5 and the second inner surface 8 of the lifting cushion also increases. Using this measured distance, the height of the lifting cushion 1 can be determined, which in this case corresponds to the distance between the first outer surface 16 of the flange and the second outer surface 19 of the flange. To determine the height of the lifting cushion 1 from the distance measured by the distance sensor 11, the heights of flanges 15 and 18, respectively, simply need to be added to the measured distance between the two inner surfaces 17 and 20 of the flanges.

[0106] Depending on where on the lifting cushion 1 the distance between the inner surfaces 5 and 8 of the lifting cushion is measured, it may be necessary to determine the height of the lifting cushion 1 using calculation formulas, extrapolation, tables, and / or based on empirical values ​​from the measured distance.

[0107] The change in height of the lifting cushion 1 is called the stroke. The stroke can be defined absolutely or relatively. The absolute stroke refers to a minimum height of the lifting cushion 1 at which it is filled with no or only a minimal amount of pressurized fluid. In this state, the stroke is zero. The relative stroke can be referenced to any height of the lifting cushion 1, for example, the height of the lifting cushion 1 at the start of lifting the load, a height to be reached, a maximum achievable height, or the like.

[0108] The height and / or stroke of the lifting cushion 1 are preferably determined by the measuring device 10 or by an evaluation unit integrated into the lifting cushion 1. This has the advantage that the lifting cushion 1 can be used autonomously with the stroke determination capability. Only an external compressed air control system would then be required for the operation of the lifting cushion 1.

[0109] However, it is also conceivable that the data recorded by measuring device 10 could be forwarded to an external evaluation unit by means of a transmitter unit belonging to measuring device 10, in particular wirelessly, so that the evaluation and / or calculation of the height and / or stroke can be carried out externally. The transmitter unit can also be configured exclusively or additionally to send the height or stroke to an external unit.

[0110] The distance measurement can be optimized by a reference surface 12 on the inner surface 5 or 8 of the lifting cushion opposite the distance sensor. In this case, the second inner flange surface 20 itself can constitute a reference surface 12, or it can have a separate reference surface 12. Such a reference surface 12 can, for example, have a specific position and / or orientation relative to the distance sensor 11, and / or a specific surface with properties such as good reflectivity, particularly suited to the measuring principle of the distance sensor 11. In this case, the second inner flange surface 20 itself forms the reference surface 12.

[0111] The measuring housing 13 may also contain additional sensors and / or other components belonging to the measuring device 10. These may be arranged in the measuring housing 13 together with the distance sensor 11.

[0112] In particular, the measuring device 10 includes a rechargeable energy storage device (not shown in the figures) which can be arranged in the measuring housing 13.

[0113] The lifting cushion 1 or the measuring device 10 itself can have an electrical connection socket (not shown in the figures) via which the rechargeable energy storage device can be charged. Alternatively or additionally, the electrical connection socket can also serve to directly supply power to the measuring device 10.

[0114] To determine further parameters of the lifting cushion 1, the measuring device 10 can include additional sensors, in particular an acceleration sensor, a pressure sensor, a temperature sensor, a height sensor, and / or an inclination sensor. The additional sensors are arranged, in particular, in the measuring housing 13. The measured values ​​of the additional sensors can also be taken into account when determining the distance, height, and / or stroke.

[0115] Fig. 5 shows one of the Figs. 1 to 4 Alternative embodiment of a lifting cushion 1 with a measuring device 10 for determining the stroke of the lifting cushion 1. The measuring device 10 is arranged off-center on the first wall 3. The distance sensor 11 is arranged in an edge region of the first wall 3, but can also be arranged in any other off-center position. In other words, the distance sensor 11 is arranged at a distance from the center line M. However, it can be advantageous to arrange the distance sensor 11 as close as possible to the center of the first wall 3 – i.e., close to the center line M – since the change in distance during inflation of the lifting cushion 1 is greatest in the center region. The distance sensor 11 is integrated into the first wall 3 and arranged flush with the first inner surface 5 of the lifting cushion.

[0116] The in Fig. 5The flanges 15 and 18 shown are not required for measuring the distance in this embodiment.

[0117] The distance sensor 11 detects the distance between the first inner surface 5 of the lifting cushion and the second inner surface 8 of the lifting cushion. The distance sensor 11 is located on the first inner surface 5 of the lifting cushion. A reference surface 12 is located on the second inner surface 8 of the lifting cushion, opposite the distance sensor 11. The distance sensor 11 is thus configured and positioned such that it detects the distance between the distance sensor 11 itself and the reference surface 12.

[0118] The measured distance between the two inner surfaces 5 and 8 of the lifting cushion is not linearly related to the height of the lifting cushion 1. This results, among other things, from the slightly inclined arrangement of the distance sensor 11 from the outset, as well as from the deformation of the walls 3 and 6 of the lifting cushion 1 during inflation, since the beam angle of the distance sensor 11 changes during inflation.

[0119] The distance can be adjusted – as already described in the previous example of the Figs. 1 to 4 described - based on the geometry of the lifting cushion 1 and, if necessary, also based on calculation formulas and / or empirical values, can be converted in such a way that the height of the lifting cushion 1 can be determined.

[0120] Fig. 6 shows a third embodiment, as an alternative to the two embodiments from the Figs. 1 to 5In this embodiment, a reference component 14 is associated with the distance sensor 11. The reference component 14 belongs to the measuring device 10, but is arranged externally to the other components of the measuring device 10. The reference component 14 is not located in the measuring housing 13.

[0121] The distance sensor 11 detects the distance between the two inner surfaces 5 and 8 of the lifting cushions by means of data communication with the reference component 14. This data communication does not require a free measuring path between the distance sensor 11 and the reference component 14 – as is the case, for example, with optical distance measurement. Furthermore, detecting the distance via data communication has the advantage that a change in the orientation of the distance sensor 11 has no influence on the distance measurement, since no directional measuring beams need to strike the opposite inner surface 5 or 8 of the lifting cushions.

[0122] The reference component 14 is generally arranged on the inner surface 5 or 8 of the lifting cushion opposite the distance sensor 11. In this case, the reference component 14 is integrated into the second wall 6 and arranged flush with the second inner surface 8 of the lifting cushion.

[0123] The reference component 14 itself can be actively configured for data communication with the distance sensor 11 and, in particular, may have its own power supply. However, it is also conceivable that the reference component 14 is connected to the power supply of the measuring device or operates passively.

[0124] A distance sensor 11 with an associated reference component 14 can also be provided in the embodiments according to the Figs. 1 to 5 be provided for.

[0125] In all three embodiments shown, the lifting cushion 1 can be configured to be used in a stack of several lifting cushions 1. In a stack of, for example, two lifting cushions 1, the lifting cushions 1 are arranged one above the other such that first a lower lifting cushion 1 is placed on the surface and the upper lifting cushion 1 is placed on the first lifting surface 4 of the lower lifting cushion 1. The second lifting surface 7 of the upper lifting cushion 1 points towards the first lifting surface 4 of the lower lifting cushion 1.

[0126] The two lifting cushions 1 can be connected to each other via a mechanical connecting element in the form of a connecting pin. The flanges 15 and 18 each have a connecting receptacle 22 for this purpose, which serves to positively engage the connecting element.

[0127] The lifting cushions 1 of the stack can each have a measuring device 10 as described in the application. The heights or strokes of the individual lifting cushions 1, determined by means of the measuring devices 10, can then be combined to obtain a total height of the stack and / or a total stroke of the stack. In particular, the individual measuring devices 10 of the lifting cushions 1 transmit the respective measured / determined distances, heights, and / or strokes to a central unit, which in turn determines the total height and / or the total stroke. Reference symbol list

[0128] 1 Lifting cushion 2 Internal volume 3rd wall 4th lifting surface 5th lifting cushion inner surface 6 Second wall 7 Second lifting surface 8 Second lifting cushion inner surface 9-valve 10 Measuring device 11 Distance sensor 12 Reference surface 13 Measuring housing 14 Reference component 15th flange 16th flange outer surface 17th flange inner surface 18 Second flange 19 Second flange outer surface 20 Second flange inner surface 22 Connection receptacle Centerline of the lifting cushion

Claims

1. A lifting cushion (1) for lifting a load, wherein the lifting cushion (1) is designed to be inflatable from a flat state for placing underneath the load into an inflated state for lifting the load by enlarging an inner volume (2) enclosed by the lifting cushion (1), wherein the lifting cushion (1) has a first wall (3) with a first lifting surface (4) facing the load, and with a first lifting cushion inner surface (5) facing the inner volume (2), and wherein the lifting cushion (1) has a second wall (6) arranged opposite the first wall (3) with a second lifting surface (7) facing away from the load, and with a second lifting cushion inner surface (8) facing the inner volume (2), characterized in that the lifting cushion (1) comprises a measuring device (10) with a distance sensor (11) for determining a lift of the lifting cushion (1), wherein the measuring device (10) is configured in such a manner that for determining the lift, a distance between the first lifting cushion inner surface (5) and the second lifting cushion inner surface (8) is detected by the distance sensor (11).

2. The lifting cushion (1) according to the preceding claim, characterized in that the distance sensor (11) is designed as a radar distance sensor, an optical distance sensor, an inductive distance sensor, or an ultrasonic distance sensor.

3. The lifting cushion (1) according to any one of the preceding claims, characterized in that the measuring device (10) comprises an energy storage device, in particular a rechargeable energy storage, for supplying energy to the distance sensor (11).

4. The lifting cushion (1) according to any one of the preceding claims, characterized in that the measuring device (10) comprises an acceleration sensor which detects an acceleration acting on the measuring device (10).

5. The lifting cushion (1) according to any one of the preceding claims, characterized in that the measuring device (10) comprises a pressure sensor which detects the pressure in the inner volume (2) of the lifting cushion (1).

6. The lifting cushion (1) according to any one of the preceding claims, characterized in that the measuring device (10) comprises a temperature sensor which detects the temperature in the inner volume (2) of the lifting cushion (1), and / or the measuring device (10) comprises a height sensor which detects the height of the measuring device (10) with respect to the surroundings of the lifting cushion (1), and / or the measuring device (10) comprises an inclination sensor which detects the inclination of the measuring device (10).

7. The lifting cushion (1) according to any one of the preceding claims, characterized in that the lifting cushion (1) has an electrical connection socket via which the measuring device (10) can be supplied with energy, and / or via which a rechargeable / the rechargeable energy storage of the measuring device (10) can be charged.

8. The lifting cushion (1) according to any one of the preceding claims, characterized in that the distance sensor (11) is attached to the first lifting cushion inner surface (5) or the second lifting cushion inner surface (8).

9. The lifting cushion (1) according to any one of the preceding claims, characterized in that the first lifting cushion inner surface (5) or the second lifting cushion inner surface (8) has a reference surface (12) with the aid of which the distance sensor (11) determines the distance between the first lifting cushion inner surface (5) and the second lifting cushion inner surface (8).

10. The lifting cushion (1) according to any one of the preceding claims, characterized in that a measuring housing (13) with the measuring device (10) arranged in the measuring housing (13) is attached to the first lifting cushion inner surface (5) or the second lifting cushion inner surface (8), in particular is attached centrally to the first lifting cushion inner surface (5) or the second lifting cushion inner surface (8).

11. The lifting cushion (1) according to any one of the preceding claims, characterized in that the first wall (3) has an integrated first flange (15), wherein, preferably, a first flange outer surface (16) of the first flange (15) forms part of the first lifting surface (4), wherein, further preferably, a first flange inner surface (17) of the first flange (15) forms part of the first lifting cushion inner surface (5), and / or the second wall (6) has an integrated second flange (18), wherein, preferably, a second flange outer surface (19) of the second flange (18) forms part of the second lifting surface (7), wherein, further preferably, a second flange inner surface (20) of the second flange (18) forms part of the second lifting cushion inner surface (8), wherein, preferably, the first flange (15) or the second flange (18) has a measuring receptacle for the measuring device (10), wherein the measuring device (10) is arranged within the measuring receptacle.

12. The lifting cushion (1) according to claims 10 and 11, characterized in that the measuring housing (13) is arranged on the first flange inner surface (17) or the second flange inner surface (20).

13. The lifting cushion (1) according to claim 11 or 12 and to claim 9, characterized in that the reference surface (12) is formed as part of the first flange inner surface (17) or as part of the second flange inner surface (20).

14. The lifting cushion (1) according to any of claims 11 to 13, characterized in that the first flange inner surface (17) is arranged opposite and parallel to the second flange inner surface (20), and / or the first flange inner surface (17) is arranged centrally with respect to the first lifting cushion inner surface (5), and / or the second flange inner surface (20) is arranged centrally with respect to the second lifting cushion inner surface (8), and / or the first flange (15) and / or the second flange (18) have a connection receptacle (22) for a mechanical connection element, wherein with the aid of the mechanical connection element, two lifting cushions (1) stacked on top of each other can be mechanically connected to each other via flanges (15, 18) arranged facing each other.

15. A method for determining a lift of a lifting cushion (1), wherein the lifting cushion (1) is designed to be inflatable from a flat state for placing underneath a load into an inflated state for lifting the load by enlarging an inner volume (2) enclosed by the lifting cushion (1), wherein the lifting cushion (1) has a first wall (3) with a first lifting cushion inner surface (5) facing the inner volume (2), and wherein the lifting cushion (1) has a second wall (6) arranged opposite the first wall (3) with a second lifting cushion inner surface (8) facing the inner volume (2), comprising the following steps: • changing the inner volume (2) enclosed by the lifting cushion (1) by inflating it with pressurized medium or by releasing pressurized medium; • detecting a distance of the first lifting cushion inner surface (5) to the second lifting cushion inner surface (8) before and after the change in the inner volume (2); • determining the lift of the lifting cushion (1) taking into account the detected distances.

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