NL2025933A - Formwork levelling device - Google Patents
Formwork levelling device Download PDFInfo
- Publication number
- NL2025933A NL2025933A NL2025933A NL2025933A NL2025933A NL 2025933 A NL2025933 A NL 2025933A NL 2025933 A NL2025933 A NL 2025933A NL 2025933 A NL2025933 A NL 2025933A NL 2025933 A NL2025933 A NL 2025933A
- Authority
- NL
- Netherlands
- Prior art keywords
- load
- chamber
- formwork
- pump
- lifting
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C1/00—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles
- B66C1/10—Load-engaging elements or devices attached to lifting or lowering gear of cranes or adapted for connection therewith for transmitting lifting forces to articles or groups of articles by mechanical means
- B66C1/105—Lifting beam permitting to depose a load through an opening
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G19/00—Auxiliary treatment of forms, e.g. dismantling; Cleaning devices
- E04G19/003—Arrangements for stabilising the forms or for moving the forms from one place to another
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G11/00—Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs
- E04G11/06—Forms, shutterings, or falsework for making walls, floors, ceilings, or roofs for walls, e.g. curved end panels for wall shutterings; filler elements for wall shutterings; shutterings for vertical ducts
- E04G11/08—Forms, which are completely dismantled after setting of the concrete and re-built for next pouring
- E04G11/082—Retractable forms for the inside face of at least three walls
Abstract
The present invention relates to a load levelling device, configured to be suspended for supporting a load and configured to be adjusted to hold the load in a levelled orientation, comprising a hydraulic cylinder with a cylinder barrel, defining an interior that is filled with a fluid, a piston, slidably arranged within the barrel interior to separate the barrel interior in a first chamber, having a first volume, and a second chamber, having a second volume, and a piston rod, which is attached to the piston and which protrudes from the barrel interior. The load levelling device further comprises a pump, fluidly connected to the first chamber and the second chamber and configured to pump the fluid from the first chamber to the second chamber, in order to slide the piston within the cylinder barrel and to reduce the length of the load levelling device, e.g. to raise the load.
Description
P34621NLOO/TRE Title: Formwork levelling device Field of the invention The present invention relates to a load levelling device, e.g. a formwork levelling device. The present invention further relates to a method for levelling a load by means of the load levelling device and to a method for removing a formwork from a concrete structure by means of the load levelling device.
State of the art Nowadays, it is common to make buildings out of concrete, whereby the concrete is casted in a tunnel formwork. Such a tunnel formwork generally comprises a ceiling and two opposed sidewalls. When multiple tunnel formworks are positioned side-by-side, multiple building walls and ceilings, for example even an entire floor of an apartment or office building, may be casted in one go.
Once the concrete has hardened up to a certain extent, the formwork can be removed from the freshly-casted concrete structure, in order to be positioned at a subsequent casting location. To remove the formwork, it is generally lowered to a small extent, typically about 10 cm, and is rolled out of the concrete structure at a head end opening thereof. At this point, the formwork needs to be supported by a crane, in order to prevent tilting of the formwork, which would otherwise possibly damage the concrete, and to prevent the formwork from falling down.
In NL7410525A, a method for removing formwork from a concrete structure is disclosed. It is shown in this publication that, initially, the formwork is completely surrounded by the concrete. When the formwork is rolled out of the concrete structure, a first lifting point of the formwork becomes exposed. The formwork is then supported by a crane with this lifting point, via a load levelling device and a first chain attached thereto. When the formwork is rolled further out of the concrete structure, a second lifting point becomes exposed, which is connected to the crane by means of a second chain. A length of this second chain is somewhat larger than the combined length of the load levelling device and the first chain. At this point, the formwork also needs to become supported by the second chain. To do so, the load levelling device is operated to increase its length, such that the combined length of the load levelling device and the first chain now becomes equal to the length of the second chain.
The load levelling device is thereto equipped with a hydraulic cylinder filled with fluid, a fluid reservoir and a valve. Upon remote actuation of the valve, e.g. by manually pulling a line, the valve is opened and the fluid is allowed to flow from the cylinder towards the reservoir, under influence of the weight of the formwork. As a result, the cylinder’s piston rod is moved further out of the cylinder’s barrel, effecting an increase in length of the load levelling device.
When the load is removed, an accumulated pressure in the reservoir may force the piston rod back into the cylinder’s barrel, thereby again reducing the length of the load levelling device.
This known load levelling device may be useful for lowering the formwork, but it must be operated very carefully.
Care must be taken that the piston rod is not moved out of the barrel too far, since this could possibly result in the formwork tilting over too far.
When this happens, it is not possible to raise the formwork again, since the accumulated pressure in the reservoir is not sufficient to overcome the weight of the formwork, and the formwork might end up getting stuck in the concrete structure.
The crane cannot be used to simply raise the formwork, since it needs to keep at least the first attachment point of the formwork supported with the load levelling device, to prevent the formwork from damaging the fresh concrete.
A second crane needs to be ordered quickly to level the formwork.
As a result, such a mistake of lowering the formwork could end up in large delays and additional costs.
Object of the invention It is therefore an object of the invention to provide a load levelling device and a load levelling, e.g. formwork removal method that overcomes the above-mentioned drawbacks, or at least to provide an alternative device and method.
Detailed description The present invention provides a load levelling device, configured to be suspended for supporting a load and configured to be adjusted to hold the load in a levelled orientation, comprising a first, e.g. upper, attachment point, from which the load levelling device is adapted to be suspended during use, a second, e.g. lower, attachment point, which is configured to support the load during use, and a hydraulic cylinder.
The hydraulic cylinder comprises a cylinder barrel, defining an interior that is filled with a fluid, a piston, slidably arranged within the barrel interior to separate the barrel interior in a first chamber, having a first volume, and a second chamber, having a second volume, and a piston rod, which is attached to the piston and which protrudes from the barrel interior.
The cylinder barrel or the piston rod is connected to the first attachment point and, respectively, the piston rod or the cylinder barrel is connected to the second attachment point.
During use, the fluid is selectively allowed to flow from the second chamber to the first chamber under influence of the weight of the load, in order to slide the piston within the cylinder barrel and to change a length of the load levelling device between the first attachment point and the second attachment point, e.g. to lower the load.
The load levelling device further comprises a pump, fluidly connected to the first chamber and the second chamber and configured to pump the fluid from the first chamber to the second chamber, in order to slide the piston within the cylinder barrel and to reduce the length of the load levelling device between the first attachment point and the second attachment point, e.g. to raise the load.
With the load levelling device according to the present invention, it is no longer only possible to increase the length of the load levelling device, e.g. of the hydraulic cylinder thereof, passively under the influence of the weight of the load that is supported by the load levelling device. Instead, the pump of the load levelling enables the fluid to be pumped from the first chamber of the hydraulic cylinder to the second chamber of the hydraulic cylinder, or vice versa, to decrease the length of the load levelling device, even when a load is supported by the load levelling device.
In this way, the present invention provides a solution for the above-mentioned problem of over-compensating with the load levelling device, e.g. of irreversibly lowering the load too far. Instead, the load may simply be raised again with the load levelling device according to the present invention, providing that the lowering of the load is no longer irreversible.
As a result, the load levelling device is less prone to operational errors, which provides that the method of levelling a load, and in particular the method of removing a formwork from a concrete structure, can be carried out mare conveniently.
It is therefore less likely that mistakes will occur, such as the formwork getting stuck in the concrete structure. Even if such a mistake of lowering the load too far were to occur, the load, e.g. the formwork, can be simply raised with the inventive load levelling device, which may provide for fewer delays and for lower costs.
According to the present invention, the load levelling device comprises a first attachment point and a second attachment point, for example a first lifting eye and a second lifting eye. The first attachment point may, at least during use for levelling loads, be an upper attachment point, being used to suspend the load levelling device, for example to suspend the load levelling device from a crane. The second attachment point may, at least during use, be a lower attachment point, being used to support the load. As such, the load may be supported by the crane indirectly, e.g. via the load levelling device.
The first attachment point may be connected to the cylinder’s barrel and the second attachment point may be connected to the cylinder’s piston rod. In this way, the piston rod may protrude from the bottom end of the barrel.
Alternatively, the second attachment point may be connected to the cylinder’s barrel and the first attachment point may be connected to the cylinder’s piston rod. In this way, the piston rod may protrude from the top end of the barrel.
In the present load levelling device, the pump is fluidly connected to the first chamber of the cylinder and to the second chamber of the cylinder. In this way, the fluid can be pumped out of the first chamber and into the second chamber. The piston is thereby slid through the barrel by the increasing volume of the second chamber and the decreasing volume of the first chamber. Accordingly, the piston rod, being connected to the piston, is moved further into of the barrel, which gives the result that the first attachment point and the second attachment point are moved towards each other. Accordingly, the length of the load levelling device between the first attachment point and the second attachment point is reduced and the load is lifted least partially by the load levelling device, at least when the first attachment point, e.g. the crane’s hook is held stationary.
With the load levelling device, it is therefore not only possible to lower the load for its levelling, as in the known formwork levelling device, but instead it is also possible to raise the load. In case the load is erroneously lowered too much, it may thus be easily raised again.
In an embodiment of the load levelling device, the pump is further configured to pump the fluid from the second chamber to the first chamber, in order to slide the piston within the cylinder barrel and to increase the length of the load levelling device between the first attachment point and the second attachment point.
According to this embodiment, the fluid can be pumped out of the second chamber and into the first chamber. The piston is thereby slid through the barrel by increasing volume of the first chamber and decreasing volume of the second chamber. Accordingly, the piston rod, being connected to the piston, is moved further out of the barrel, which gives the result that the first attachment point and the second attachment point are moved away from each other.
Accordingly, the length of the load levelling device between the first attachment point and the second attachment point is increased and the load is lowered least partially by the load levelling device, at least when the first attachment point, e.g. the crane’s hook is held stationary.
With the load levelling device according to the present embodiment, it is not only possible to raise the load by means of the pump, but also to lower the load by means of the pump. Compared to the known formwork levelling device, which relied on a remotely- operated valve for enabling the fluid to flow from the second chamber into the first chamber by gravity, the load levelling device according to the present embodiment allows lowering of the load by means of the pump, which may allow for increased controllability of the lowering.
In an embodiment, the load levelling device further comprises a fluid line, fluidly interconnecting the first chamber and the second chamber, and a valve, arranged in the fluid line and configured to selectively block the fluid from flowing from the first chamber to the second chamber or vice versa, wherein the pump is arranged at least partially in the fluid line, configured to pump the fluid through the fluid line.
In this embodiment, the pump is fluidly connected to the first chamber and the second chamber via this fluid line. During use of the pump for pumping the fluid from the first chamber to the second chamber, or vice versa, the fluid thereby flows through the fluid line. When it is not desired to increase or decrease the length of the load levelling device, for example when the load has been levelled properly, it may be desirable to prevent the fluid from flowing from the first chamber to the second chamber, or vice versa.
5 In the absence of a valve, this may be effected by blocking the pump, to prevent the fluid flow. In the present embodiment, the valve may be used to block the fluid line to prevent the fluid from flowing from the first chamber to the second chamber, or vice versa. In this way, the load levelling device according to the present embodiment may be secured against undesired increases and decreases in length.
In an embodiment, the load levelling device further comprises a control unit, which is connected to the pump and configured to selectively activate the pump to pump the fluid from the first chamber to the second chamber, or vice versa, upon external actuation.
According to this embodiment, it may be obsolete to activate the pump manually, since the control unit is provided to activate the pump. The control unit may do so on external actuation, for example upon receipt of an actuation signal.
Furthermore, the control unit may also be configured to selectively deactivate the pump to stop the pumping of fluid from the first chamber to the second chamber, or vice versa, upon external actuation.
Finally, the control unit may also be configured to activate the pump to operate in reverse order. For example, the control unit may activate the pump to pump the fluid from the second chamber to the first chamber when it is already activated to pump the fluid from the first chamber to the second chamber, or vice versa.
In a further embodiment, the load levelling device further comprises a transmitter device, configured to transmit an actuation signal, and a receiver device, connected to the control unit and configured to receive the actuation signal from the transmitter device and to actuate the control unit to activate the pump.
The actuation signal for the control unit is, in the present embodiment, transmitted from the transmitter device to the receiver device. The transmitter device may be electronically connected to the receiver device, for example via a cable. In this way, the transmitter device may be located remotely from the receiver device. Accordingly, a human operator of the load levelling device, being in charge of operation, that holds the transmitter device, may be located at a distance, e.g. at a safe distance from the load levelling device and the load.
In a further embodiment of the load levelling device, the actuation signal is a wireless actuation signal, for example an infrared, Bluetooth or Wi-Fi actuation signal.
According to the present embodiment, the transmitter device is connected to the receiver device in a wireless manner, making it obsolete to have a physical connection, like a cable, in between them. The wireless connection enables the operator to be located even further away from the load levelling device, improving the flexibility of the load levelling device and the usability thereof, for example when removing tunnel formworks from high-rise buildings.
In an embodiment, the control unit is configured to suspend activation of the pump when, during use, a weight of the load exceeds a predetermined threshold weight.
As such, the control unit is configured to prevent the load levelling device from levelling loads that are too heavy. Such heavy loads could otherwise damage the cylinder and/or the pump, as it may require fluid pressures that are above technical limits for the load levelling device.
According to the present embodiment, the pump is deactivated by the control unit when the load is too heavy. For example, the control unit may deactivate the pump for pumping the fluid from the first chamber to the second chamber, e.g. for the lifting of the load, but may allow activation for pumping the fluid from the second chamber to the first chamber for lowering the load, since the lowering is assisted by gravity.
In a further embodiment, the load levelling device further comprises one or more pressure sensors in the first chamber, the second chamber and/or the fluid line, configured to emit one or more pressure sensor signals that are representative for pressure levels in the first chamber, the second chamber and/or the fluid line, respectively, and the control unit is configured to suspend activation of the pump when a pressure sensor signal exceeds a predetermined pressure sensor signal.
The pressure sensors are configured to determine the pressure level of the fluid in the first chamber, the second chamber and/or the fluid line. The pressure level of the fluid is thereby representative for the weight of the load that supported by the load levelling device, wherein the pressure level in the second chamber may for example be multiplied by the surface area of the piston to obtain the gravitational load.
The control unit may have the predetermined pressure sensor signal stored and may be configured to repeatedly compare the pressure sensor signal with the predetermined pressure sensor signal, e.g. during use of the load levelling device. When the pressure sensor signal excess the predetermined pressure sensor signal, the control unit will suspend the activation of the pump, e.g. preventing further pumping of fluid between the first chamber and the second chamber.
When the pressure sensor signal will drop below the predetermined pressure sensor signal, the control unit may be configured to re-activate the pump again, for continuing the pumping of the fluid between the first chamber and the second chamber.
In an embodiment, the pump is an electrical pump, and the load levelling device further comprises an electric power supply, for example comprising one or more batteries, that is connected to the pump and configured to provide electrical power for the pump.
According to the present embodiment, the electric power supply may allow that the load levelling device does not need to be physically connected to an external power supply, for example to a generator or the power grid, but rather comprises its own source of electrical power. This contributes to the flexibility and allows the load levelling device to be used at locations where no external power is present, for example in buildings that are under construction and/or at large heights.
In an embodiment, the load levelling device further comprises a housing, defining an interior, wherein the pump and preferably also the control unit, the receiver device and/or the electric power supply are located in the interior of the housing.
The housing is thereby configured to protect the respective control unit, receiver device and/or electric power supply from external influences, for example against weather conditions and/or damaging that could possibly result from collisions of the load levelling device, for example with the ground or with the concrete structures from which formworks are to be removed.
In a further embodiment, the load levelling device comprises a skid, connected to the hydraulic cylinder and the housing and configured to form a support for the load levelling device when not in use, e.g. for resting on a ground surface.
The skid may protect the other components of the load levelling device, and in particular the components that are located in the interior of the housing. The load levelling device is configured to rest on a ground surface with the skid, in order to be rigidly supported, to be held in a correct orientation, e.g. to prevent possible leakages from the fluid inside the load levelling device, and to be moveable, for example by means of a forklift.
In an embodiment, the load levelling device is a formwork levelling device, configured to be suspended for supporting a formwork and configured to be adjusted to hold the formwork in a levelled orientation.
The present invention further provides a method for levelling a load by means of the load levelling device as described above, comprising the step of pumping the fluid from the first chamber to the second chamber, thereby reducing the length of the load levelling device between the first attachment point and the second attachment point.
With the method according to the present invention, it is no longer only possible to level a load under the influence of its weight, e.g. by selectively lowering the load at least partially. Instead, the pump of the load levelling enables the fluid to be pumped from the first chamber of the hydraulic cylinder to the second chamber of the hydraulic cylinder, in order to be able to raise the load.
In this way, the present method provides a solution for the over-compensating with a load levelling device, e.g. of irreversibly lowering the load too far. Instead, the load may simply be raised again with the load levelling device, providing that the lowering of the load is no longer irreversible.
The present invention further provides a method for removing a formwork from a concrete structure by means of the load levelling device as described above, preferably by means of the formwork levelling device as described above, comprising the steps of: - suspending the load levelling device from a crane with the first attachment point thereof, - suspending a lifting line, e.g. a chainsling, that comprises at least one leg from the crane, - rolling the formwork partly out of the concrete structure to reveal at least one first lifting point, e.g. a first lifting lug or a first lifting eye, of the formwork, - connecting the at least one first lifting point to the second attachment point of the load levelling device, - further rolling the formwork partly out of the concrete structure, while supporting the formwork at least partly with the load levelling device, to reveal at least one second lifting point, e.g. a second lifting lug or a second lifting eye, of the formwork, - connecting the at least one second lifting point to the at least one leg of the lifting line, and - rolling the formwork out of the concrete structure completely, while levelling the formwork with the load levelling device, wherein the step of levelling comprises: 0 raising the at least one first lifting point of the formwork with the load levelling device when the at least one first lifting point is located lower than the at least one second lifting point, wherein the raising is carried out by pumping the fluid from the first chamber of the hydraulic cylinder of the load levelling device to the second chamber, thereby reducing the length of the load levelling device, and
0 lowering the at least one first lifting point of the formwork with the load levelling device when the at least one first lifting point is located higher than the at least one second lifting point, wherein the lowering is carried out by pumping the fluid from the second chamber of the hydraulic cylinder of the load levelling device to the first chamber, thereby increasing the length of the load levelling device.
With the method according to the present invention, the formwork can be removed from the concrete structure being levelled horizontally, without damaging the fresh concrete and without the formwork getting stuck.
According to this method, the formwork is supported by means of the lifting line and the load levelling assembly. The formwork is first supported via the load levelling device, as soon as the at least one first lifting point, for example two first lifting points located next to each other, becomes accessible, e.g. no longer being located within the concrete structure. The formwork is rolled further out of the concrete structure, while remaining supported by the load levelling device and the concrete structure.
As soon as the at least one second lifting point, for example two second lifting points located next to each other, is accessible, the lifting line is attached to this second lifting point. Each leg of the lifting line may be connected to a respective second lifting point of the formwork. At this point, the formwork not needs to be supported via the lifting line, since the formwork still rests on the concrete structure. When the formwork is rolled further out of the concrete structure, the formwork becomes supported by the lifting line.
Due to this rolling, the balance of the forces acting on the formwork will shift, wherein this balance of the forces comprises gravitational forces, tensional forces at the first lifting point and the at the second lifting point, and normal forces that act on the formwork from the concrete structure. When hanging free. the formwork only remains in the correct orientation when its centre of gravity becomes located below the crane, e.g. the hook of the crane, in the levelled position. To keep the formwork levelled, the relative position between the formwork and the crane’s hook is adjusted. This adjusting is done by changing the length of the load levelling device, in order to raise or lower the formwork, or at least to raise or lower the first lifting point of the formwork, thereby holding the first lifting point at the same height as the second lifting point that is supported by the lifting line, of which the length is not adjustable.
In particular, the length of the load levelling device is increased, in order to compensate for the shifting balance of forces on the formwork, e.g. so that the centre of gravity of the formwork becomes located in between the first lifting point and the second lifting point.
In an embodiment of the method, the second attachment point of the load levelling device is connected to the at least one first lifting point of the formwork by means of a further lifting line, such as a lifting chain or a chainsling.
This embodiment may be useful when the length of the load levelling device by itself does not substantially correspond to the length of the lifting line. With the further lifting line, the overall length between the crane’s hook and the first attachment point may increase, in order to substantially correspond to the length of the lifting line.
The present invention finally provides a method for removing a formwork from a concrete structure by means of the load levelling device as described above, preferably by means of the formwork levelling device as described above, comprising the steps of: - suspending the load levelling device from a crane with the first attachment point thereof, - suspending a lifting line, e.g. a chainsling, that comprises at least one leg from the crane, - rolling the formwork partly out of the concrete structure to reveal at least one first lifting point, e.g. a first lifting lug or a first lifting eye, of the formwork, - connecting the at least one first lifting point to the at least one leg of the lifting line, and - further rolling the formwork partly out of the concrete structure, while supporting the formwork at least partly with the lifting line, to reveal at least one second lifting point, e.g. a second lifting lug or a second lifting eye, of the formwork, - connecting the at least one second lifting point to the second attachment point of the load levelling device, - rolling the formwork out of the concrete structure completely, while levelling the formwork with the load levelling device, wherein the step of levelling comprises: 0 raising the at least one second lifting point of the formwork with the load levelling device when the at least one second lifting point is located lower than the at least one first lifting point, wherein the raising is carried out by pumping the fluid from the first chamber of the hydraulic cylinder of the load levelling device to the second chamber, thereby reducing the length of the load levelling device, and 0 lowering the at least one second lifting point of the formwork with the load levelling device when the at least one second lifting point is located higher than the at least one first lifting point, wherein the lowering is carried out by pumping the fluid from the second chamber of the hydraulic cylinder of the load levelling device to the first chamber, thereby increasing the length of the load levelling device.
This method is similar to the removal method as described above, whereas the load levelling device is now connected to the second lifting point of the formwork and whereas the lifting line is connected to the first lifting point of the formwork, e.g. being the opposite of the method described above.
In an embodiment of this method, the second attachment point of the load levelling device is connected to the at least one second lifting point of the formwork by means of a further lifting line, such as a lifting chain or a chainsling. Brief description of drawings Further characteristics of the invention will be explained below, with reference to embodiments, which are displayed in the appended drawings, in which: Figure 1 schematically depicts an embodiment of the load levelling device according to the present invention, Figure 2 schematically depicts a diagram with major components of the load levelling device of figure 1, and Figures 3A — 3F schematically depict an embodiment of the method for removing a formwork from a concrete structure according to the present invention.
Throughout the figures, the same reference numerals are used to refer to corresponding components or to components that have a corresponding function. Detailed description of embodiments Figure 1 schematically depicts an embodiment of the load levelling device according to the present invention, to which is referred with reference numeral 1. The load levelling device 1 is configured to be suspended for supporting a load 100, e.g. a formwork and configured to be adjusted to hold the load 100 in a levelled orientation. The load levelling device 1 comprises a hydraulic cylinder 10, which comprises a cylinder barrel 11. The barrel 11 has an interior 12 that is filled with a fluid. The cylinder 10 further comprises a piston 13, which is slidably arranged within the interior 12 of the barrel 11, to separate the interior 12 of the barrel 11 in a first chamber 14, having a first volume V1, and a second chamber 15, having a second volume V2. The cylinder 10 also comprises a piston rod 18, which is attached to the piston 13 and which protrudes at least partly from the interior 12 of the barrel 11. The load levelling device 1 comprises a first attachment point 2 and a second attachment point 3, which are respectively embodied as a first, e.g. upper lifting eye 2 and as a second, e.g. lower lifting eye 3. The first lifting eye 2 is, at least during use of the load levelling device 1 for levelling loads, used to suspend the load levelling device 1 from a crane
110. The second lifting eye 3 is, at least during use of the load levelling device 1 for levelling loads, used to support the load 100. As such, the load 100 may be supported by the crane 110 indirectly, e.g. via the load levelling device 1.
The first lifting eye 2 is connected to the barrel 11 of the cylinder 10 and the second lifting eye 3 is connected to the piston rod 16 of the cylinder 10. In this way, the piston rod 16 protrudes from the bottom end of the barrel 11 during use of the load levelling device 1.
The load levelling device 1 further comprises a housing 20, which defines an interior 21.
Several components of the load levelling device 1, such as its pump, control unit, receiver device and the electric power supply, which are discussed later, are located in the interior 21 of the housing 20. The housing 21 is thereby configured to protect the respective components from external influences and damaging.
The levelling device 1 also comprises a skid 22, which is connected to the hydraulic cylinder 10 and the housing 20. The skid 22 is configured to form a support for the load levelling device 1 when not in use, e.g. for resting on a ground surface. The skid 22 is also configured to protect the other components of the load levelling device 1, and in particular the components that are located in the interior 21 of the housing 20. The skid 22 is further configured to hold the load levelling device 1 in a correct orientation, e.g. to prevent possible leakages from the fluid inside the load levelling device 1, and to be moveable, for example by means of a forklift with its forklift brackets 23.
Figure 2 schematically depicts a diagram with major components of the load levelling device 1 described above. It is shown in figure 2 that the barrel 11 of the cylinder 10 is connected to the first lifting eye 2 and that the piston rod 16 is connected to the second lifting eye 3.
The load levelling device 1 comprises a fluid line 30, which fluidly interconnects the first chamber 14 and the second chamber 15, and a valve 31, which is arranged in the fluid line 30 and configured to selectively block the fluid from flowing from the first chamber 14 to the second chamber 15 or vice versa.
The load levelling device 1 further comprises a pump 40, which is arranged at least partially in the fluid line 30 and which is fluidly connected to the first chamber 14 and the second chamber 15, via the fluid line 30. The pump 40 is configured to pump the fluid from the first chamber 14 to the second chamber 15, or vice versa, in order to slide the piston 13 within the barrel 11 of the cylinder 10, to change the length L of the load levelling device 1 between the first lifting eye 2 and the second lifting eye 3.
In particular, the load levelling device 1 is configured to raise a load 100 supported by the second lifting eye 3 when the fluid is pumped from the first chamber 14 to the second chamber 15, to reduce the length L of the load levelling device 1 between the first lifting eye 2 and the second lifting eye 3. The piston 13 is thereby slid through the barrel 11 by the increasing volume V2 of the second chamber 15 and the decreasing volume V1 of the first chamber 14. Accordingly, the piston rod 16, being connected to the piston 13, is moved further into of the barrel 11, which gives the result that the first lifting eye 2 and the second lifting eye 3 are moved towards each other. Accordingly, the length L of the load levelling device 1 between the first lifting eye 2 and the second lifting eye 3 is reduced and the load 100 is lifted least partially by the load levelling device 1, at least when the first lifting eye 2, e.g. a hook of the crane 110 is held stationary.
Similarly, the load levelling device 1 is configured to lower a load 100 supported by the second lifting eye 3 when the fluid is pumped from the second chamber 15 to the first chamber 14, or when the fluid flows in that direction under the influence of the weight of the load 100, to increase the length L of the load levelling device 1 between the first lifting eye 2 and the second lifting eye 3. The piston 13 is thereby slid through the barrel 11 by the increasing volume V1 of the first chamber 14 and the decreasing volume V2 of the second chamber 15. Accordingly, the piston rod 16, being connected to the piston 13, is moved further out of of the barrel 11, which gives the result that the first lifting eye 2 and the second lifting eye 3 are moved away from each other. Accordingly, the length L of the load levelling device 1 between the first lifting eye 2 and the second lifting eye 3 is increased and the load 100 is lowered least partially by the load levelling device 1, at least when the first lifting eye 2, e.g. a hook of the crane 110 is held stationary.
The valve 31 is configured to selectively block the fluid line 30 to prevent the fluid from flowing from the first chamber 14 to the second chamber 15, or vice versa, in order to secure the load levelling device 1 against undesired increases and decreases in length L, for example when the load 100 is properly levelled.
The pump is an electrical pump 40, and the load levelling device 1 further comprises an electric power supply 50, for example comprising one or more batteries, that is connected to the pump 40 and configured to provide electrical power for the pump 40.
The load levelling device 1 further comprises a control unit 41, which is connected to the pump 40 and configured to selectively activate the pump 40 to pump the fluid from the first chamber 14 to the second chamber 15, or vice versa, upon external actuation. The control unit 41 is further configured to also selectively deactivate the pump 40 to stop the pumping of fluid from the first chamber 14 to the second chamber 15, or vice versa, upon external actuation.
The load levelling device 1 further comprises a transmitter device 42, configured to transmit a wireless infrared actuation signal S, and a receiver device 43, connected to the control unit 41 and configured to receive the wireless actuation infrared signal S from the transmitter device 42 and to actuate the control unit 41 to activate the pump 40.
The load levelling device 1 further comprises a plurality of pressure sensors, configured to emit pressure sensor signals that are representative for pressure levels. A first pressure sensor 61 is arranged in the first chamber 14 and is configured to emit a pressure sensor signal that is representative for a pressure level in the first chamber 14. A second pressure sensor 62 is arranged in the second chamber 15 and is configured to emit a pressure sensor signal that is representative for a pressure level in the second chamber 15. A third pressure sensor 63 is arranged in the fluid line 30 and is configured to emit a pressure sensor signal that is representative for a pressure level in the fluid line 30. These pressure levels of the fluid are representative for the weight of the load 100 that supported by the load levelling device 1, wherein the pressure level in the second chamber 15 may for example be multiplied by the surface area of the piston 13 to obtain the gravitational load.
Each of the pressure sensors 81, 62, 63 is connected to the control unit 41 and the control unit 41 is configured to suspend activation of the pump 40 when a pressure sensor signal exceeds a predetermined pressure sensor signal, in particular when a pressure sensor signal from the first pressure sensor 61 exceeds a predetermined first pressure sensor signal, when a pressure sensor signal from the second pressure sensor 62 exceeds a predetermined second pressure sensor signal and when a pressure sensor signal from the third pressure sensor 63 exceeds a predetermined third pressure sensor signal. These predetermined pressure sensor signals are representative for maximum loads, e.g. maximal weights thereof, for the load levelling device 1 and may represent fluid pressures that reach technical limits for the load levelling device 1.
The control unit 41 has the predetermined pressure sensor signals stored and is, during use of the load levelling device, configured to repeatedly compare the pressure sensor signals from the pressures sensors 61, 62, 63 with the predetermined pressure sensor signal. When one or more of the pressure sensor signals excess the respective predetermined pressure sensor signals, the control unit 41 is configured to suspend the activation of the pump 40, e.g. preventing further pumping of fluid between the first chamber 14 and the second chamber 15. When the pressure sensor signals will drop below the respective predetermined pressure sensor signal again, the control unit 41 is configured to re-activate the pump 40 again, for continuing the pumping of the fluid between the first chamber 14 and the second chamber 15. In this way, the control unit 41 is configured to suspend activation of the pump 40 when, during use, a weight of the load 100 exceeds a predetermined threshold weight, which could otherwise damage the cylinder 10 and/or the pump 40.
In figures 3A — 3F, an embodiment of the method for the removing of a formwork 100 from a concrete structure 200 according to the present invention is schematically depicted. In figure 3A, it is shown that the formwork 100 is supported on rollers 101 in the concrete structure 200.
As a first step, shown in figure 3B, the load levelling device 1 is suspended from a crane 110 with its first lifting eye 2. A chainsling 70 is also suspended from the crane 110. The second lifting eye 3 of the load levelling device 1 is connected to a further chainsling 71. Then, the formwork 100 is rolled partly out of the concrete structure 200 to reveal two first lifting points 102 of the formwork 100. The two first lifting points 102 of the formwork 100 are, via respective legs of the further chainsling 71, connected to the load levelling device 1. At this point, the formwork 100 is partly supported via the load levelling device 1 and partly supported in the concrete structure 200.
Next, as is displayed in figure 3C, is the formwork 100 rolled further out of the concrete structure 200 to reveal two second lifting points 103, for example to an extent that a centre of gravity Z of the formwork 100 is located outside the concrete structure 200. The formwork 100 thereby still remains supported by the concrete structure 200 and by the load levelling device
1. As soon as the second lifting points 103 are accessible, the chainsling 70 is attached to these second lifting points 103, wherein each leg of the chainsling 70 is connected to a respective second lifting point 103 of the formwork 100. At this point, the formwork 100 not needs to be supported via the chainsling 70, since the formwork 100 still rests on the concrete structure 200.
Furthermore, the formwork 100 still needs to be supported by the load levelling device 1, because its centre of gravity Z is located outside the concrete structure 200. If the formwork 100 were not to be supported by the load levelling device 1, the fresh concrete could become damaged as a result of tilting of the formwork 100 and the formwork 100 could possible fall down.
When the formwork 100 is rolled further out of the concrete structure 200, as in figure 3D, the formwork 100 also becomes supported by the chainsling 70. The load levelling device 1 is thereby used to level the formwork 100.
This may be needed, because the balance of the forces acting on the formwork 100 will shift during the rolling of the formwork 100 out of the concrete structure 200. This balance of the forces comprises gravitational forces, tensional forces at the first lifting points 102 and the at the second lifting points 103, and normal forces that act on the formwork 100 from the concrete structure 200. When hanging free. the formwork 100 only remains in the correct orientation when its centre of gravity Z becomes located below the crane 110, e.g. the hook of the crane 110, in the levelled position.
To keep the formwork 100 levelled, the relative position between the formwork 100 and the crane 110 is adjusted. This adjusting is done by changing the length of the load levelling device 1, in order to raise or lower the formwork 100, or at least to raise or lower the first lifting points 102 of the formwork 100. As a result, the height of the first lifting points 102 may change by changing the length of the load levelling device 1. However, the height of the second lifting points 103 remains unchanged, because the length of the chainsling 70 is not adjustable.
Effectively, the position of the load levelling device 1 will change with respect to the formwork 100, as is indicated by the arrow in figure 3D. In the end, the hook of the crane 110° will become positioned right above the centre of gravity Z of the formwork 100 to keep the formwork 100 levelled.
With formwork 100 being levelled horizontally, it can be rolled out of the concrete structure 200 completely, as is displayed in figure 3E. The load levelling device 1 thereby enables the formwork 100 to be removed from the concrete structure 200 without damaging the fresh concrete and without the formwork 100 getting stuck.
It is shown in figure 3F, that the load levelling device 1 enable the first lifting points 102 to be lifted for levelling the formwork 100. An initial position of the formwork 100, in which the first lifting points 102 are located lower than the second lifting point 103, is shown by means of dashed line. The load levelling device 1 is configured to raise the first lifting points 102, wherein the raising is carried out by pumping the fluid from the first chamber 14 of the hydraulic cylinder 10 of the load levelling device 1 to the second chamber 15, thereby reducing the length of the load levelling device 1. Then, the formwork 100 arrives in a levelled position, extending substantially horizontally, which is displayed in figure 3F with the solid lines.
Claims (15)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2025933A NL2025933B1 (en) | 2020-06-29 | 2020-06-29 | Formwork levelling device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL2025933A NL2025933B1 (en) | 2020-06-29 | 2020-06-29 | Formwork levelling device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| NL2025933A true NL2025933A (en) | 2022-02-28 |
| NL2025933B1 NL2025933B1 (en) | 2022-04-29 |
Family
ID=74095956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| NL2025933A NL2025933B1 (en) | 2020-06-29 | 2020-06-29 | Formwork levelling device |
Country Status (1)
| Country | Link |
|---|---|
| NL (1) | NL2025933B1 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL7410525A (en) | 1974-08-06 | 1976-02-10 | Ind Handelsonderneming En Meta | Item removal process from tubular chamber - attaches rope of hydraulically adjustable length to protruding end |
| DE3333108A1 (en) * | 1983-09-14 | 1985-03-28 | Martin Theodor 6639 Rehlingen Melchior | Crane spreader bar for hanging on the hoisting rope of a crane, in particular a building crane |
| US6048012A (en) * | 1997-06-12 | 2000-04-11 | Selby; Cloyd R. | Understructure lifting beam |
| WO2017007613A1 (en) * | 2015-07-08 | 2017-01-12 | General Electric Company | System and method for lifting with a spreader bar |
-
2020
- 2020-06-29 NL NL2025933A patent/NL2025933B1/en active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL7410525A (en) | 1974-08-06 | 1976-02-10 | Ind Handelsonderneming En Meta | Item removal process from tubular chamber - attaches rope of hydraulically adjustable length to protruding end |
| DE3333108A1 (en) * | 1983-09-14 | 1985-03-28 | Martin Theodor 6639 Rehlingen Melchior | Crane spreader bar for hanging on the hoisting rope of a crane, in particular a building crane |
| US6048012A (en) * | 1997-06-12 | 2000-04-11 | Selby; Cloyd R. | Understructure lifting beam |
| WO2017007613A1 (en) * | 2015-07-08 | 2017-01-12 | General Electric Company | System and method for lifting with a spreader bar |
Also Published As
| Publication number | Publication date |
|---|---|
| NL2025933B1 (en) | 2022-04-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8177193B2 (en) | Grain bin lifting system and method | |
| CA2968277C (en) | Tower crane for erecting a wind turbine, and method for erecting said tower crane | |
| CA2410225C (en) | Mast for handling a coiled tubing injector | |
| US8528755B2 (en) | Mobile crane having counterweight | |
| US7845882B2 (en) | Subsea suction pile crane system | |
| KR101327824B1 (en) | A raising unit of superstructure of the bridge, apparatus for raising a superstructure of the bridge, and method for simutaneously raising the superstructure of the bridge using thereof | |
| GB2433734A (en) | Adjustable counterbalance system | |
| US10124773B1 (en) | Chassis-stabilizing system | |
| US6048012A (en) | Understructure lifting beam | |
| CN106144914B (en) | Method for operating a crane and crane | |
| NL2025933B1 (en) | Formwork levelling device | |
| US20150336776A1 (en) | Utility truck with boom and deformation monitoring sensors | |
| JP2017043430A (en) | Weight floating amount adjustment device of moving crane and weight floating amount adjustment method | |
| WO2021199965A1 (en) | Deep foundation excavator | |
| CN105384090A (en) | Automatic erecting of a crane | |
| RU2584701C2 (en) | Unit | |
| KR102331929B1 (en) | Weight lifter | |
| KR102331930B1 (en) | Method for lifting weight loads and apparatus therefor | |
| US11427987B2 (en) | Hydraulic system for a fall-back support and work machine | |
| US9789978B2 (en) | System for following the handling of an aircraft engine | |
| JP7132821B2 (en) | Work vehicle safety device | |
| KR101976529B1 (en) | Movable apparatus for lifting ship | |
| CN217206450U (en) | Supporting platform sling levelling device behind shaft entry driving machine | |
| JPS60234091A (en) | Tension controller for suspension cable in submersible-body elevation apparatus | |
| US3985237A (en) | Device to raise and lower box-shaped construction elements, in particular prefabricated garages |