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] Lifting bags for lifting loads above ground are well known in the art. They have a variable internal volume, which can be significantly increased by filling them with a pressurized medium, such as compressed air. By increasing the internal volume, loads resting on the lifting bag can be lifted. Such lifting bags 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 bag with pressurized medium, a valve connection is also provided, which can provide a continuous connection from the environment to the variable internal volume of the bladder for inflating the lifting bag with air or deflating it.

[0003] Depending on their size, lifting bags are capable of lifting loads of several tons over several decimetres or metres. They can be used to lift vehicles, machinery, concrete components, building debris, and the like. To lift a load, such a lifting bag is placed flat and uninflated beneath the load and then usually inflated with compressed air. This causes the lifting bag to expand and increase in height or thickness. When the lifting bag makes contact with the load, it lifts the load. The change in thickness or height of the lifting bag during inflation is also referred to as the lifting bag's stroke.

[0004] Lifting bags can also be used to lift loads at an angle, shift them sideways, or spread components apart. Practical applications include, for example, lifting vehicles, lifting components of collapsed buildings, especially concrete parts, or shifting loads sideways, as well as spreading jammed vehicle doors or vehicle parts after accidents. The inclined lifting, shifting sideways, or spreading occurs analogously to the lifting of a load in a vertical direction primarily described in the application, so that the lifting of the load in the present application should always be understood as representative of the other applications as well.

[0005] When the lifting bag is inflated, depending on its design, two opposing curved walls typically form. One of the two walls curves outward toward the load, and the other wall curves outward toward the ground.

[0006] Due to its two curved walls, the lifting bag deforms from its flat state to a round or spherical shape when inflated. To monitor this inflation process, both the pressure within the lifting bag and the height of the lifting bag, or its stroke, are of interest. If the pressure becomes too great, the lifting bag can tear or burst. If the height of the lifting bag becomes too great, the lifting bag can become too round and possibly roll out under the load. Furthermore, the pressure and stroke are interdependent variables, so these two variables can be used to determine the condition and load of the lifting bag.

[0007] 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.

[0008] Until now, the stroke of lifting bags during load lifting has only been measured manually, for example, by repeatedly measuring the distance between the ground and the load with a folding rule. Such measurements are highly inaccurate and cumbersome to perform.

[0009] Therefore, the object of the invention is to provide a lifting bag and a method which optimizes the determination of the stroke of the lifting bag.

[0010] This object is achieved by the subject matter and methods having the features of the independent claims. Further, particularly advantageous embodiments of the invention are disclosed in the respective dependent claims and the following description.

[0011] It should be noted that the features listed individually in the claims can be combined with one another in any technically reasonable manner (even across category boundaries, for example, between methods and devices) and demonstrate further embodiments of the invention. The description further characterizes and specifies the invention, particularly in conjunction with the figures.

[0012] It should also be noted that a conjunction "and / or" used herein between two features and linking them together is always to be interpreted in such a way that in a first embodiment of the subject matter according to the invention only the first feature can be present, in a second embodiment only the second feature can be present and in a third embodiment both the first and the second feature can be present.

[0013] According to the present invention, the lifting bag is designed for lifting a load, wherein the lifting bag is designed to be inflatable from a flat state for placing beneath the load by enlarging an internal volume enclosed by the lifting bag to an inflated state for lifting the load. The lifting bag has a first wall with a first lifting surface facing the load and with a first lifting bag inner surface facing the internal volume. The lifting bag also has a second wall arranged opposite the first wall with a second lifting surface facing away from the load and with a second lifting bag inner surface facing the internal volume.The lifting cushion is characterized in that it has a measuring device with a distance sensor for determining a stroke of the lifting cushion, wherein the measuring device is configured such that a distance between the first lifting cushion inner surface and the second lifting cushion inner surface is detected by the distance sensor in order to determine the stroke.

[0014] The lifting bag has a variable internal volume for filling with a pressure medium, in particular compressed air, to increase the variable internal volume. The lifting bag is designed for lifting loads. For this purpose, the lifting bag can have a bladder, wherein the bladder encloses the variable internal volume. In particular, the bladder is made of vulcanized rubber material or homogeneous raw rubber.

[0015] The bladder can be surrounded by a reinforcement layer arranged around the inner bladder, facing the external environment. The environment includes, for example, the substrate and the load. The reinforcement layer can serve, on the one hand, to protect the bladder from damage caused by contact with the load or the substrate, and, on the other hand, to strengthen the bladder, enabling it to absorb higher pressures and loads, for example.

[0016] It can be provided that the reinforcement layer and the inner bladder are integrally bonded to one another, in particular vulcanized together.

[0017] The reinforcement layer can be integrated into the bladder, eliminating the need for a separate internal bladder. In other words, the bladder is reinforced by an integrated reinforcement layer.

[0018] The reinforcement layer can be formed as a fabric layer, for example made of Kevlar.

[0019] The lifting bag is placed under the load in a flat, uninflated or only partially inflated state. Whether or how much the lifting bag is inflated is of secondary importance. The lifting bag only needs to be flat enough to be positioned in a gap or space between the load and the ground. After being placed under the load, the lifting bag is inflated or further inflated.

[0020] When the lifting bag is not inflated, it is in a non-inflated state, which can also be referred to as the basic state or flat state. In the non-inflated state, the lifting bag can be designed as a flat cuboid, flat cube, flat prism or flat cylinder, each with a low height. A low height or flat in this context means that the height is many times smaller than the other dimensions of the lifting bag, such as a width and a length, or a diameter. If the lifting bag has a cuboid basic shape in the non-inflated state, a cross-section of the lifting bag in the inflated state can be elliptical or circular. In this view, the cross-section runs through a minimum diameter of the lifting bag in the inflated state, for example.

[0021] When the lifting bag is inflated, two opposing curved walls form. The first of the two walls curves outward toward the load, forming a convex lifting surface facing the load. The other side of the first wall faces the interior volume and is concave.

[0022] The second wall of the lifting bag is curved toward the ground, forming a convex lifting surface facing away from the load. The other side of the second wall is facing toward the interior volume and is concave.

[0023] Due to the two curved walls, the lifting bag deforms from its flat state towards a round or spherical state when inflated.

[0024] The two walls are essentially made of a flexible material, such as rubber, so that the lifting bag can be inflated and deformed accordingly. However, the walls can also include sections made of solid material, such as the flanges described later in the application.

[0025] The lifting bags can lift loads of varying weights depending on their size. Practical tests have shown that a lifting bag with a square base shape, i.e., when deflated, with a width and length of 14 cm each, can lift a load of approximately 1.3 t. With a width and length of 32 cm, approximately 10 t can be lifted; with a width and length of 61 cm, approximately 40 t; with a width of 86 cm, approximately 80 t; and with a width of 95 cm, approximately 100 t. These dimensions correspond in magnitude to the typical sizes of the lifting bags discussed here, as well as to the typical loads that can be lifted.

[0026] Essential to the invention is that the lifting bag comprises a measuring device with which the lifting bag's stroke can be determined. For this purpose, the measuring device has a distance sensor configured to detect a distance between the first inner surface of the lifting bag and the second inner surface of the lifting bag. The stroke and / or height of the lifting bag can then be determined using the distance between the two inner surfaces of the lifting bag.

[0027] For this purpose, the distance sensor is arranged either on the first inner surface of the lifting cushion or on the second inner surface. The distance is measured from the distance sensor to the opposite inner surface of the lifting cushion. The distance sensor can be arranged on the inner surface of the lifting cushion or integrated into the inner surface of the lifting cushion or into one of its walls. The distance sensor can, in particular, be integrated into the inner surface of the lifting cushion such that it is flush with the inner surface of the lifting cushion.

[0028] In principle, the distance sensor can be located anywhere on the inner surface of the lifting bag. However, it is particularly suitable for the distance sensor to be located centrally, i.e., in the geometric center of one of the inner surfaces of the lifting bag, and to measure the distance to the geometric center of the opposite inner surface of the lifting bag.

[0029] The height of the lifting bag can be determined by the distance between the two lifting surfaces of the lifting bag, preferably by the distance from the two vertices of the convex lifting surfaces, or the distance from the two vertices of the concave inner surfaces of the lifting bag. However, the height of the lifting bag can also be determined by the distance between the load and the ground.

[0030] The lifting bag's lift height is the difference between the actual height of the lifting bag and a reference height of the lifting bag. The reference height can be, for example, a minimum height of the lifting bag or a height at a specific time, such as when the lifting bag begins to inflate, when the load is lifted, or when the lifting bag first makes contact with the load.

[0031] The height of the lifting bag can be determined directly by the sensor directly detecting or outputting the height of the lifting bag.

[0032] However, the height can also be measured indirectly. This means that the distance measured by the distance sensor must be converted into the height of the lifting bag. For example, if the distance sensor measures the distance between the two vertices of the concave inner surfaces of the lifting bag, the height can be calculated by adding the thicknesses of the lifting bag's walls.

[0033] If the distance between the two inner surfaces of the lifting cushion is measured by the sensor at a location other than the vertices, the distance between the vertices can be determined, for example, by extrapolating the measured distance.

[0034] It is also possible to determine the stroke directly by simply having the distance sensor detect the change in the distance between the inner surfaces of the lifting bag. To do this, the distance sensor can determine a reference value for the distance at any time (for example, at the beginning of lifting the load, or when the lifting bag is flat, or when the measuring device is switched on) and then output only the change in the distance relative to the 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 the distance is detected, with this change then corresponding to the stroke.

[0035] If the distance between the vertices of the concave inner surfaces is measured, the measured change in the distance usually corresponds directly to the stroke of the lifting bag. If the distance is measured at a different location on the inner surfaces of the lifting bag, the measured distance can be extrapolated and / or converted to obtain the change in the distance between the vertices of the inner surface of the lifting bag, i.e., the stroke.

[0036] Advantageous embodiments and variants of the invention emerge from the dependent claims and the following description. The features listed individually in the dependent claims can be combined with each other in any technically reasonable manner, as well as with the features explained in more detail in the following description, and represent other advantageous embodiments of the invention.

[0037] In one embodiment of the lifting bag, the distance sensor is designed as a radar distance sensor, an optical distance sensor, an inductive distance sensor, or an ultrasonic distance sensor.

[0038] Optical distance sensors can particularly use laser beams for measurements.

[0039] In a further embodiment of the lifting bag, the measuring device comprises 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 arranged in the lifting bag. The energy storage device can be designed as a battery or a rechargeable accumulator. The energy storage device can be replaceable or permanently connected to the measuring device or the lifting bag. Such an energy storage device integrated into the lifting bag has the advantage that the lifting bag does not need to be connected to an external electrical power source.

[0040] It is advantageous if the energy storage unit is designed to be rechargeable, so that it does not have to be replaced when it is empty. Therefore, the lifting bag features an electrical connection socket through which the rechargeable energy storage unit can be recharged.

[0041] Alternatively or additionally, the measuring device can be supplied with power directly via the electrical connection socket. With direct power supply, the energy storage device can be omitted, or the measuring device can only be supplied with electrical power when needed, i.e., when no external electrical power is available via the connection socket.

[0042] In a further embodiment of the lifting bag, the measuring device comprises an acceleration sensor that detects the acceleration acting on the measuring device. Such a sensor can be used for further analysis of the condition of the lifting bag.

[0043] In a further embodiment of the lifting bag, the measuring device comprises a pressure sensor that measures the pressure in the internal volume of the lifting bag. As mentioned at the beginning, the pressure and the stroke of the lifting bag are directly related. The higher the pressure, the greater the stroke of the lifting bag. The height of the load also has a direct influence on the pressure and stroke of the lifting bag. The heavier the load, the higher the pressure in the lifting bag and the lower the stroke of the lifting bag. Thus, the condition of the lifting bag can be determined more precisely using a pressure sensor. Using the pressure in the lifting bag measured by the pressure sensor in combination with the stroke or height of the lifting bag, conclusions can also be drawn about the height of the load.

[0044] In a further embodiment of the lifting bag, the measuring device includes a temperature sensor that measures the temperature in the interior of the lifting bag. This temperature allows for a better assessment of the condition of the compressed air within the lifting bag, since pressure and temperature are also directly related to gases. For example, the temperature in the lifting bag can be used to draw conclusions about excessive compression or expansion of the compressed air within the lifting bag.

[0045] In a further embodiment of the lifting bag, the measuring device comprises an altitude sensor that detects the height of the measuring device above sea level. Such an altitude sensor can, for example, detect the pressure in the area surrounding the lifting bag, 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, so that the inflation process of the lifting bag can be optimized. For example, the power of a compressor for inflating the lifting bag can be adjusted according to the altitude above sea level.

[0046] In a further embodiment of the lifting bag, the measuring device comprises an inclination sensor that detects the inclination of the measuring device. The inclination of the lifting bag can, for example, be the inclination of a reference surface of the lifting bag relative to a vertical, or the inclination of a center line of the lifting bag relative to a vertical, or the inclination of an axis of symmetry of the lifting bag relative to a vertical. In this way, the absolute inclination of the lifting bag can be determined.

[0047] It is also conceivable that the inclination is measured relative to a normal to the ground, rather than a vertical line. This allows the inclination of the lifting bag relative to the ground to be determined.

[0048] In a further embodiment of the lifting bag, the distance sensor is connected to the first inner surface of the lifting bag or the second inner surface of the lifting bag. For this purpose, the distance sensor can be flush with one of the inner surfaces of the lifting bag or arranged on one of the inner surfaces of the lifting bag. Starting from the inner surface of the lifting bag to which the distance sensor is connected, the distance sensor then measures the distance to the other, opposite inner surface of the lifting bag. The direct connection of the distance sensor to one of the inner surfaces of the lifting bag has the advantage that the distance sensor directly follows the movements and deformations of the inner surface of the lifting bag to which it is connected, allowing the distance to the opposite inner surface of the lifting bag to be determined very precisely.

[0049] In a further embodiment of the lifting cushion, the first lifting cushion inner surface or the second lifting cushion inner surface comprises a reference surface by means of which the distance sensor determines the distance between the first lifting cushion inner surface and the second lifting cushion inner surface.

[0050] Such a reference surface can be beneficial for the measurement, depending on the measuring principle used by the distance sensor. For example, the reference surface can be flat.

[0051] It is also conceivable for the reference surface to have 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 facilitate the measurement of the distance sensor.

[0052] The reference surface is arranged in particular on the lifting cushion inner surface, which is arranged opposite the lifting cushion inner surface with the distance sensor.

[0053] In a further embodiment of the lifting bag, a measuring housing with the measuring device arranged in the measuring housing is connected to the first inner surface of the lifting bag or the second inner surface of the lifting bag. The measuring housing is designed to accommodate the individual components of the measuring device, such as the distance sensor and the energy storage device.

[0054] 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 bag when the lifting bag is in a flat position, or when the load is too heavy and the inner surfaces of the lifting bags touch. In these cases, the measuring housing protects the measuring device from unwanted mechanical impacts.

[0055] In particular, the measuring housing is connected centrally to the first lifting bag inner surface or the second lifting bag inner surface. Centrally in this context means that the measuring housing is arranged, for example, in the geometric center of the lifting bag inner surface or, for example, at the apex of the concave lifting bag inner surface.

[0056] In a further embodiment of the lifting bag, the first wall comprises an integrated first flange. Preferably, a first flange outer surface of the first flange forms part of the first lifting surface. Further preferably, a first flange inner surface of the first flange forms part of the first lifting bag inner surface.

[0057] Alternatively or additionally, the second wall has an integrated second flange. Preferably, a second flange outer surface of the second flange forms part of the second lifting surface. Further preferably, a second flange inner surface of the second flange forms part of the second lifting cushion inner surface.

[0058] The flanges are therefore particularly integrated into the respective wall of the lifting bag, so that the respective flange outer sides and flange inner sides are aligned with the lifting surfaces and the lifting bag inner surfaces.

[0059] In a lifting bag with two flanges, the distance between the two inner surfaces of the lifting bag can be determined between the two inner surfaces of the flange, particularly if the two inner surfaces of the flange are arranged parallel to each other. The first inner surface of the flange can therefore be arranged opposite and parallel to the second inner surface of the flange in the lifting bag.

[0060] The flanges are designed as solid bodies, for example, made of metal, aluminum, or plastic. The flanges can improve the connection of the lifting bag to the load and the ground by providing a firm and, in particular, level support surface for the load or the ground.

[0061] In a further embodiment of the lifting bag, the first flange or the second flange comprises a measuring mount for the measuring device, with the measuring device being arranged within the measuring mount. Arranging the measuring device in one of the flanges is advantageous because these are designed as solid bodies, making it easy to attach the measuring device to or in the flanges.

[0062] The measuring receptacle 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 bag. This prevents mechanical damage to the measuring device when the inner surfaces of the lifting bag rest against each other, for example, when the lifting bag is in a flat state.

[0063] In a further embodiment of the lifting bag, the measuring housing with the measuring device is arranged on the first flange inner surface or the second flange inner surface. This arrangement is advantageous because the measuring housing can be attached to one of the flanges much more easily than to the otherwise flexible wall of the lifting bag.

[0064] The reference surface can also be formed as part of the first flange inner surface or as part of the second flange inner surface. Such an arrangement is particularly suitable when the distance sensor detects the distance between the two flange inner surfaces.

[0065] In a further embodiment of the lifting bag, the first flange inner surface is arranged centrally with respect to the first lifting bag inner surface, and / or the second flange inner surface is arranged centrally with respect to the second lifting bag inner surface. Such a central arrangement in this context means that the respective flange inner surface is arranged, for example, in the geometric center of the lifting bag inner surface. The flange inner surfaces can also be arranged on the center line or axis of symmetry of the lifting bag.

[0066] In a further embodiment of the lifting bag, the first flange and / or the second flange has a connection receptacle for a mechanical connecting element, wherein, with the aid of the mechanical connecting element, two lifting bags stacked on top of one another can be mechanically connected to one another via flanges arranged facing one another.

[0067] If more than one lifting bag is used to lift the load, the lifting bags can be stacked on top of each other. To give such a stack of lifting bags greater stability, the lifting bags can be connected to each other using mechanical connectors. To do this, adjacent lifting bags in the stack must each have a connector socket, and the connector sockets must be arranged facing each other. The facing connector sockets can then be connected to each other using a mechanical connector.

[0068] Such a mechanical connecting element could, for example, be a pin, which can be positively connected at both ends to one of the connecting receptacles. In this way, two adjacent lifting bags can be mechanically connected to each other via the pin.

[0069] The invention also relates to a method for determining a stroke of a lifting bag, wherein the lifting bag is designed to be inflatable from a flat state for placing under a load by enlarging an internal volume enclosed by the lifting bag into an inflated state for lifting the load, wherein the lifting bag has a first wall with a first lifting bag inner surface facing the internal volume, and wherein the lifting bag has a second wall arranged opposite the first wall with a second lifting bag inner surface facing the internal volume.

[0070] The procedure comprises at least the following steps: Changing the internal volume enclosed by the lifting bag by inflating it with a pressure medium or deflating it; detecting a distance between the first lifting bag inner surface and the second lifting bag inner surface before and after the change in the internal volume; determining the stroke of the lifting bag taking into account the detected distances.

[0071] Instead of the stroke, only the height of the lifting cushion can be determined.

[0072] The present invention will be explained in detail below using exemplary embodiments with reference to the accompanying figures. They show: Figure 1a lifting bag for lifting a load in a flat, non-inflated state, with a measuring device for determining a stroke of the lifting bag, Figure 2the lifting bag from Fig. 1 in a sectional view, Figure 3 the lifting cushion from Fig. 1in a further sectional view, Figure 4 shows an enlarged section of the area of ​​the measuring device Fig. 3 , Figure 5 shows a further embodiment of a lifting cushion, with an alternatively arranged measuring device, Figure 6 shows a further embodiment of a lifting cushion, with a reference component for the distance sensor.

[0073] In the figures, unless otherwise stated, the same reference symbols designate the same or corresponding components with the same function.

[0074] Figure 1 shows a lifting bag 1 for lifting a load in a flat state, i.e., a non-inflated state. The lifting bag 1 has a measuring device 10 arranged within the lifting bag 1 for determining a stroke of the lifting bag 1, so that this Fig. 1 cannot be seen.

[0075] The lifting cushion 1 can be used in the Fig. 1The lifting bag 1 is placed under the load in the flat state shown. To lift the load, the lifting bag 1 is inflated. In the flat state, the height of the lifting bag 1 is many times lower than its height in the inflated state.

[0076] The lifting bag 1 encloses an internal volume 2, which can be expanded by filling it with a pressure medium, such as compressed air. Increasing the internal volume 2 increases the height of the lifting bag 1, allowing a load resting on the lifting bag 1 to be lifted.

[0077] To increase the internal volume 2, the lifting bag 1 has a valve 9 through which the pressure medium can be supplied to the lifting bag 1. To reduce the internal volume 2, the pressure medium can also be released via the valve 9.

[0078] The supply or discharge of pressure medium can be carried out using a compressed air control, which is usually located externally to the lifting bag 1. The compressed air control is connected to the lifting bag 1 via a compressed air connection via the valve 9. It is conceivable that the compressed air control is connected to the measuring device 10 of the lifting bag 1 and uses this to adjust and / or regulate the control of the compressed air.

[0079] The internal volume 2 of the lifting bag 1 is defined in the direction of the load by a first wall 3, and in the direction of the subsurface 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.

[0080] However, additional walls or elements can also be arranged between the first and second walls 3 and 6, which, together with the walls 3 and 6, enclose the interior volume. For example, the first wall 3 can be connected to the second wall 6 via a seam area.

[0081] The first wall 3 and the second wall 6 are arranged along a center line M of the lifting bag 1. The geometric centers of the walls 3 and 6 are arranged on the center line M. The center line M essentially forms a rotational symmetry axis of the lifting bag 1, whereby individual elements of the lifting bag 1, such as carrying handles or the valve 9, do not have rotational symmetry with respect to the center line M.

[0082] 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 occurs 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 face away from each other.

[0083] When the lifting bag 1 is inflated, the two walls 3 and 6 have a curved shape. The first wall 3 is curved toward the load, and the second wall 6 is curved toward the ground. The two lifting surfaces 4 and 7 are thus convex.

[0084] To allow the two walls 3 and 6 to deform to increase / decrease the internal volume 2, they are designed to be at least partially flexible. The flexible parts of the walls 3 and 6 are preferably made of rubber and can be reinforced with an integrated fabric.

[0085] The lifting bag 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 arranged flush with the adjacent other parts of the lifting surfaces 4 and 7.

[0086] The flanges 15 and 18 are each arranged centrally to the corresponding lifting surfaces 4 and 7. If the lifting bag 1 is in an at least partially inflated state, with the lifting surfaces 4 and 7 already convexly shaped, the flanges 15 and 18 are each arranged at the apex of the convexly shaped lifting surfaces 4 and 7.

[0087] The flanges 15 and 18 can each be integrally connected to the associated wall 3 and 6, for example by means of a vulcanization process, in particular if part of the walls 3 and 6 are flexible and made of rubber, for example.

[0088] The flanges 15 and 18 are rigidly constructed so that they do not deform when the lifting bag 1 is inflated. This also applies to the flange outer 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 bag 1 is inflated, and thus do not become convex. The flanges 15 and 18 can be made of metal or plastic, for example, preferably aluminum.

[0089] The measuring device 10 is together with the distance sensor 11 inside the lifting cushion 1 made of Fig. 1 arranged so that the measuring device 10 in the Fig. 1cannot be seen. However, in the following sectional views of the lifting bag 1, the measuring device 10 of the lifting bag 1 is clearly visible and is identified by the Fig. 2 to 4 described in more detail.

[0090] Fig. 2 and Fig. 3 show the lifting bag 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 Fig. 2 to 4 are therefore essentially described together below.

[0091] The sectional views clearly show the interior volume 2 of the lifting bag 1. The first wall 3 has a first lifting bag inner surface 5, and the second wall 6 has a second lifting bag inner surface 8. The first lifting bag inner surface 5 merges into the second lifting bag inner surface 8. The interior volume 2 is enclosed by the two lifting bag inner surfaces 5 and 8. The walls 3 and 6 are essentially flexible - with the exception of the parts formed by the flanges 15 and 18 - so that the walls 3 and 6 bulge out when the lifting bag 1 is inflated. The lifting bag inner surfaces 5 and 8 assume a concave shape.

[0092] The first lifting bag inner surface 5 comprises a first flange inner surface 17 of the first flange 15, and the second lifting bag inner surface 8 comprises a second flange inner surface 20 of the second flange 18. The flange inner surfaces 17 and 20 are each arranged flush with the adjacent other parts of the lifting bag inner surfaces 5 and 8.

[0093] The first flange inner surface 17 is arranged parallel to the second flange inner surface 20. This is particularly the case when the lifting bag 1 is unloaded. If the lifting bag 1 is loaded by lifting a load, the flange inner surfaces 17 and 20 may no longer be aligned parallel to each other, since the load can lead to an inclination of the first flange 15 or to an inclination / deformation of the first wall 3.

[0094] The measuring device 10 is arranged on the first lifting bag inner surface 5 together with the distance sensor 11. The measuring device 10 is also arranged centrally to the first flange inner surface 17, and thus also centrally to the first lifting bag inner surface 5. 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 lifting bag inner surface 5 to the second lifting bag inner surface 8.

[0095] The presence of flanges 15 and 18 is not essential. For determining the stroke of lifting bag 1, it is only important that distance sensor 11 of measuring device 10 is arranged in a defined relative position to the first or second lifting bag inner surface 5 or 8. This can be achieved by integrating distance sensor 11 on / in one of the lifting bag inner surfaces 5 or 8, or by integrating distance sensor 11 in one of the walls 3 or 6, or by integrating distance sensor 11 in one of flanges 15 or 18, or by integrating distance sensor 11 on / in one of the flange inner surfaces 17 or 20.

[0096] 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 flange inner surface 17, and thus, in this case, to the first lifting bag inner surface 5.

[0097] To protect the measuring housing 13, the measuring device 10, and / or the distance sensor 11, a mechanical stop (not shown in the presently illustrated embodiments) 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 becoming clamped between the two flange inner surfaces 17 and 20. For this purpose, the stop is configured such that the flange inner surfaces 17 and 20 are spaced apart by the stop when the lifting bag 1 is in the non-inflated state.

[0098] However, it is also expedient 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 stresses caused by being clamped between the flanges 15 and 18.

[0099] The measuring housing 13 can be made of plastic or metal, preferably aluminum.

[0100] The distance sensor 11 is basically configured to detect a distance between the first lifting bag inner surface 5 and the second lifting bag inner surface 8. In the illustrated embodiment, this distance corresponds to the distance between the first flange inner surface 17 and the second flange inner surface 20 along the center line M.

[0101] If no flanges 15 and 18 are present on the lifting bag 1, the distance between the two vertices of the concave inner surfaces 5 and 8 of the lifting bag can also be detected by the distance sensor 11.

[0102] It is fundamentally irrelevant whether the distance sensor 11 is arranged on the first or second lifting cushion inner surface 5 or 8, or whether it has direct contact with one of the two lifting cushion inner surfaces 5 or 8. What is crucial is that the distance sensor 11 is arranged relative to one of the two lifting cushion inner surfaces 5 or 8 and in some way detects the distance to the opposite lifting cushion inner surface 5 or 8.

[0103] 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 lifting cushion inner surface 5 or 8, thus determining the distance between the first and second lifting cushion inner surfaces 5 and 8. For this purpose, a measuring opening can be provided in the measuring housing 13, through which the distance sensor 11 has a clear measuring path without optical obstructions to the opposite lifting cushion inner surface 5 or 8.

[0104] When the lifting bag 1 is inflated, the height of the lifting bag 1 increases and the distance between the first inner surface 5 of the lifting bag and the second inner surface 8 increases. Using the measured distance, the height of the lifting bag 1 can be determined, which in this case corresponds to the distance between the first flange outer surface 16 and the second flange outer surface 19. To determine the height of the lifting bag 1 from the distance measured by the distance sensor 11, one need only add the height of the flanges 15 and 18 to the measured distance between the two flange inner surfaces 17 and 20.

[0105] Depending on the location of the lifting bag 1 at which the distance between the inner surfaces 5 and 8 of the lifting bag is measured, it may be necessary to determine the height of the lifting bag 1 using calculation formulas, extrapolation, tables, and / or based on empirical values ​​from the measured distance.

[0106] The change in the height of the lifting bag 1 is referred to as the stroke. The stroke can be determined absolutely or relatively. The absolute stroke refers to a minimum height of the lifting bag 1 at which the lifting bag 1 is filled with no or only a minimal amount of pressure medium. In this state, the stroke is zero. The relative stroke can refer to any height of the lifting bag 1, for example, to a height of the lifting bag 1 at the beginning of lifting the load, or a height to be reached by the lifting bag 1, or a maximum achievable height of the lifting bag 1, or the like.

[0107] The height of the lifting bag 1 and / or the stroke of the lifting bag 1 are preferably determined by the measuring device 10 or by an evaluation device integrated into the lifting bag 1. This has the advantage that the lifting bag 1 can be used independently with the option of determining the stroke. Only an external compressed air control would then be required for the operation of the lifting bag 1.

[0108] However, it is also conceivable for the data acquired by the measuring device 10 to be forwarded, in particular wirelessly, to an external evaluation unit via a transmitter unit associated with the measuring device 10, so that the evaluation and / or calculation of the height and / or stroke can be performed externally. The transmitter unit can also be configured exclusively or additionally to transmit the height or stroke to an external unit.

[0109] The distance measurement can be optimized by a reference surface 12 on the lifting cushion inner surface 5 or 8 opposite the distance sensor. In this case, the second flange inner surface 20 itself can represent 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 have a specific surface with properties such as good reflectivity, in particular tailored to the measuring principle of the distance sensor 11. In this case, the second flange inner surface 20 itself forms the reference surface 12.

[0110] Additional sensors and / or additional components belonging to the measuring device 10 can also be arranged in the measuring housing 13. These can be arranged in the measuring housing 13 together with the distance sensor 11.

[0111] In particular, the measuring device 10 comprises a rechargeable energy storage device (not shown in the figures), which can be arranged in the measuring housing 13.

[0112] The lifting bag 1 or the measuring device 10 itself can have an electrical connection socket (not shown in the figures) through 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.

[0113] To determine further parameters of the lifting bag 1, the measuring device 10 can comprise 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.

[0114] Fig. 5 shows one of the Fig. 1 to 4 Alternative embodiment of a lifting bag 1 with a measuring device 10 for determining the stroke of the lifting bag 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 at 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 when the lifting bag 1 is inflated 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 bag.

[0115] The Fig. 5The flanges 15 and 18 shown are not required for detecting the distance in this embodiment.

[0116] The distance sensor 11 detects the distance between the first lifting cushion inner surface 5 and the second lifting cushion inner surface 8. The distance sensor 11 is arranged on the first lifting cushion inner surface 5. A reference surface 12 is arranged on the second lifting cushion inner surface 8 opposite the distance sensor 11. The distance sensor 11 is thus configured and arranged such that it detects the distance between the distance sensor 11 itself and the reference surface 12.

[0117] In this case, the measured distance between the two inner surfaces 5 and 8 of the lifting bag is not linearly related to the height of the lifting bag 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 bag 1 during inflation, since the radiation angle of the distance sensor 11 changes during inflation.

[0118] The distance can - as previously described in the example of the Fig. 1 to 4 described - based on the geometry of the lifting bag 1 and, if necessary, also based on calculation formulas and / or empirical values, in such a way that the height of the lifting bag 1 can be determined.

[0119] Fig. 6 shows a third embodiment, alternative to the two embodiments from the Fig. 1 to 5In this exemplary embodiment, a reference component 14 is assigned to the distance sensor 11. The reference component 14 is associated with the measuring device 10, but is arranged externally to the other components of the measuring device 10. The reference component 14 is not arranged in the measuring housing 13.

[0120] The distance sensor 11 detects the distance between the two lifting cushion inner surfaces 5 and 8 through 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 with optical distance measurement, for example. Detecting the distance via data communication also 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 cushion.

[0121] For this purpose, 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.

[0122] The reference component 14 itself can be actively designed for data communication with the distance sensor 11 and, in particular, can have its own power supply. However, it is also conceivable for the reference component 14 to be connected to the power supply of the measuring device or to operate passively.

[0123] A distance sensor 11 with an associated reference component 14 can also be used in the embodiments according to the Fig. 1 to 5 be provided.

[0124] In all three embodiments shown, the lifting bag 1 can be configured to be used in a stack of multiple lifting bags 1. In a stack of, for example, two lifting bags 1, the lifting bags 1 are arranged one on top of the other in such a way that first, a lower lifting bag 1 is placed on the ground, and then the upper lifting bag 1 is placed on the first lifting surface 4 of the lower lifting bag 1. The second lifting surface 7 of the upper lifting bag 1 points toward the first lifting surface 4 of the lower lifting bag 1.

[0125] The two lifting bags 1 can be connected to each other via a mechanical connecting element in the form of a connecting pin. For this purpose, the flanges 15 and 18 each have a connection receptacle 22, which serves to positively accommodate the connecting element.

[0126] 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 using the measuring devices 10 can then be combined to determine the total height of the stack and / or the total stroke of the stack. In particular, the individual measuring devices 10 of the lifting cushions 1 transmit the respectively measured / determined distances, heights, and / or strokes to a central unit, which in turn determines the total height and / or the total stroke. List of reference symbols

[0127] 1Lifting bag 2Inner volume 3first wall 4first lifting surface 5first lifting cushion inner surface 6second wall 7second lifting surface 8second lifting cushion inner surface 9Valve 10Measuring device 11Distance sensor 12Reference surface 13Measuring housing 14Reference component 15First flange 16First flange outer surface 17First flange inner surface 18Second flange 19Second flange outer surface 20Second flange inner surface 22Connection receptacle MCenterline of the lifting bag

Claims

1. 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, wherein 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), and wherein the lifting bag (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 bag inner surface (8) facing the internal volume (2), characterized in thatthe lifting cushion (1) comprises a measuring device (10) with a distance sensor (11) for determining a stroke of the lifting cushion (1), wherein the measuring device (10) is set up such that, in order to determine the stroke, 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. Lifting bag (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. Lifting bag (1) according to one of the preceding claims, characterized in that the measuring device (10) comprises an energy store, in particular a rechargeable energy store, for supplying energy to the distance sensor (11).

4. Lifting bag (1) according to one of the preceding claims, characterized in thatthe measuring device (10) comprises an acceleration sensor which detects an acceleration acting on the measuring device (10).

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

6. Lifting bag (1) according to one of the preceding claims, characterized in that the measuring device (10) comprises a temperature sensor which detects the temperature in the internal volume (2) of the lifting bag (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. Lifting bag (1) according to one of the preceding claims, characterized in thatthe 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 energy storage device of the measuring device (10) can be charged.

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

9. Lifting bag (1) according to 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) by means 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. Lifting bag (1) according to one of the preceding claims, characterized in thata measuring housing (13) with the measuring device (10) arranged in the measuring housing (13) is connected to the first lifting cushion inner surface (5) or the second lifting cushion inner surface (8), in particular is connected centrally to the first lifting cushion inner surface (5) or the second lifting cushion inner surface (8).

11. Lifting bag (1) according to 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 / orthe 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. Lifting bag (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. Lifting bag (1) according to claim 11 or 12 and claim 9, characterized in that the reference surface (12) is formed as a part of the first flange inner surface (17) or as a part of the second flange inner surface (20).

14. Lifting bag (1) according to one 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 to the first lifting bag inner surface (5), and / or the second flange inner surface (20) is arranged centrally to the second lifting bag inner surface (8), and / or the first flange (15) and / or the second flange (18) have a connection receptacle (22) for a mechanical connecting element, wherein by means of the mechanical connecting element two lifting bags (1) stacked on top of one another can be mechanically connected to one another via flanges (15, 18) arranged facing one another.

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

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