NL2034474B1

NL2034474B1 - Method for installing a crane assembly on a building under construction and crane assembly

Info

Publication number: NL2034474B1
Application number: NL2034474A
Authority: NL
Inventors: Thomas Groenendijk Gilles
Original assignee: Hem Systems B V
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2024-10-04
Also published as: AU2024244867A1; WO2024205407A1

Abstract

Method for installing a crane assembly on a building under construction, comprising the steps of: - providing a foldable crane comprising a hoisting point and a foldable crane arm rotatable 5 around an axis of rotation; - providing a supporting structure arranged for supporting the crane, wherein the supporting structure comprises a connecting mechanism for removably connecting the supporting structure to the building; - removably connecting the connecting mechanism of the supporting structure to the building 10 at a ﬁrst location; - connecting the crane to the supporting structure for forming the crane assembly.

Description

Method for installing a crane assembly on a building under construction and crane assembly

The present invention relates to a method for installing a crane assembly on a building under construction crane assembly for performing hoisting operations and a crane assembly arranged to be removably connected to a building.

Traditional construction methods typically involve the use of one or more main large tower cranes or mobile cranes which can lift objects heavier than 10 tons to a height of more than 30 meters,

During the process of constructing a building, a large amount of objects need to be lifted or hoisted, not all of which have a weight close to the maximum lifting capacity of these tower cranes. Hoisting these objects takes up a considerable amount of time, while the large lifting capacity of these tower cranes or mobile cranes is not fully used. Consequentially, a crane with a high lifting capacity is used for a considerable amount of hoisting operations that do not require this full lifting capacity. As the amount of time it takes to perform a hoisting operation is substantially independent of the weight of the object to be hoisted, time becomes a limiting factor.

In order to increase the amount of hoisting operations that can be performed, thereby speeding up the construction process, more tower cranes are typically installed. However, as these are not always used to their full lifting capacity, these cranes are not used to full efficiency.

Itis a goal of the present invention, next to other goals, to provide a method for installing a crane assembly on a building under construction, as well as a crane assembly to be used in this method wherein at least one of the above mentioned problems it at least partly alleviated.

This goal, amongst other goals, is met by a method for installing a crane assembly on a building under construction according to claim 1. More specifically, this goal, amongst other goals, is met by a method for installing a crane assembly on a building under construction, comprising the steps of: providing a foldable crane comprising a hoisting point and a foldable crane arm rotatable around an axis of rotation; providing a supporting structure arranged for supporting the crane, wherein the supporting structure comprises a connecting mechanism for removably connecting the supporting structure to the building; removably connecting the connecting mechanism of the supporting structure to the building at a first location, and; connecting the crane to the supporting structure for forming the crane assembly.

In this way, a secondary foldable crane can be used to efficiently perform lifting operations on objects that do not require the lifting capacity of a tower crane or mobile crane, thereby alleviating the main tower crane or mobile crane, allowing it to be used for lifting operations requiring a higher lifting capacity. As more hoisting operations can be performed in a given period of time by the additional use of this secondary foldable crane, construction can be efficiently sped up.

Preferably, a folding crane such as a crane frequently mounted on a truck or the like 1s used, as these are commonly available. Alternatively, any other type of crane can be employed.

In another embodiment of the method the first location is spaced from the ground at a nonzero distance. In other words, the crane assembly is not connected directly to the ground, but to a surface or other part of a building at a nonzero height from the ground. The first location is preferably a floor or a wall. As the purpose of the crane assembly is to hoist objects upwards, the crane assembly is preferably connected to a part of the building that is above the ground. As the crane assembly is preferably arranged to be compact, it is preferable that the crane assembly is connected to the building at a substantial distance to the ground to allow the crane to hoist objects to a useable height. The crane assembly is arranged to be connected to a part of the building that is not specifically intended to support a crane. Cranes known in the art may require the construction of a foundation or the like specifically for the crane. The present invention preferably does not require the construction of structures specifically intended to support a crane.

In another embodiment of the method, the step of connecting the connecting mechanism comprises connecting to a flooring structure of the building under construction. Preferably, the floor to which the crane assembly is connected is not the ground floor, alternatively referred to as the first floor, meaning the floor that is most level with the ground surrounding the building under construction.

The present methodology is intended to be compatible with a large range of construction methods.

In this embodiment, the crane assembly is removably and temporarily connected to a floor or other horizontal surface of a building under construction. It can then perform light hoisting operations to relieve the main tower crane or the like. For example, the crane can be used to aid in the construction of walls around the floor on which it is mounted.

Preferably, the method further comprises the step of providing connection holes in the building, wherein the step of connecting the connecting mechanism comprises removably connecting fasteners in the connection holes. In this way the method can be applied to many different kinds of buildings and locations in buildings, as connection holes are relatively simple to provide and do not require specialized processes or devices.

Optionally, the step of connecting comprises connecting the supporting structures at at least two different connection points at different heights. In this way the supporting structure can be stably connected to a vertical surface of a building. Alternatively, the supporting structure can be connected to a plurality of surfaces at different heights.

In another embodiment of the method, the step of connecting comprises connecting the connecting mechanism inside a tubular structure in the building, such as an elevator shaft, a staircase, a ventilation shaft, a chimney or any other vertical structure. In this way, the crane can be used to support in the construction of the elevator shatt or the like by relieving the main tower crane or the like by performing light hoisting operations.

Another embodiment of the invention further comprises the steps of: disconnecting the connecting mechanism from the building. and; removably connecting the connecting mechanism of the supporting structure to the building at a second location, different from said first location. As construction around the first location where the crane assembly is connected nears completion, the crane assembly can be disconnected and moved to a second location where it can then support construction. For example, if the crane assembly is mounted on a floor or other horizontal structure of a building under construction it may aid in the construction of the walls that may be placed on that floor, or of the floor to be constructed above the floor where the crane assembly is connected, or the crane assembly can be used to perform any other hoisting operations. When the construction of the walls or floor segment nears completion, the crane assembly may be disconnected and relocated to a second location where it can then be used to perform hoisting operations.

In another embodiment of the method, the second location is higher relative to the ground than the first location. As a building is constructed, more structures may be added increasing the height.

Therefore, the crane assembly may be disconnected from a first location and reconnected to a second location that is higher relative to the ground.

In another embodiment, the first and second location are located on the inside of an elevator shaft under construction. this embodiment, the crane assembly may be connected to an elevator shaft or the like, and employed to aid in the construction of the subsequent segment of the elevator shaft.

As that element nears completion, the crane assembly may be disconnected, moved to a second location in the elevator shaft that is higher than the first location and connected at that location.

The crane assembly may then aid in the construction of the subsequent segment of the elevator shaft or any other vertical structure.

Another embodiment of the method includes the step of hoisting the crane assembly from the first location to the second location by means of a second crane. For example, the second crane comprises a mobile crane or a tower crane. This crane may be the main crane or one of the main cranes present on the construction site. Alternatively, another crane such as a mobile crane may be used to hoist the crane assembly from the first location to the second location.

Another embodiment of the method comprises the steps of: providing a jacking system arranged on the supporting structure connected to at least one connecting mechanism, and; jacking the supporting structure from the first location to the second location. In this way the use of a second crane to move the crane assembly from the first location to a second location may not be required.

Instead, the jacking system can be used to jack the crane assembly up to a second location. The jacking system may comprise one or more mechanical jacks, hydraulic jacks, scissor jacks, bottle jacks, pneumatic jacks. or any other type of jack. The jacking system may for example comprise one or more hydraulic cylinders.

In another embodiment of the method, the second location is directly above the first location. This may be the case when the crane assembly is connected to an elevator shaft or any other vertical structure at the first location, and the crane assembly is then moved to a second location higher in the elevator shaft or on any other vertical structure, which is directly above the first location.

Preferably, the connecting mechanism 1s substantially constructed of metal, wood and/or plastic.

The connecting mechanism may alternatively be constructed of any other material such as concrete.

Another aspect relates to a method for constructing a building, comprising the steps of: providing at least one main tower crane or mobile crane or the like for the purpose of performing main hoisting operations to enable the construction operations, and; providing a crane assembly according to any of the preceding embodiments for the purpose of performing secondary hoisting operations, for example hoisting objects substantially lighter than the maximum capacity of the main crane.

Another aspect relates to a method for constructing a building, comprising the steps of: providing a slip forming system for constructing a part of the building, for example an elevator shaft, by continuous pouring, wherein the slip forming system comprises a supporting structure arranged on the interior of the part of the building under construction; providing at least one main tower crane or mobile crane or the like separate from the slip forming construction for the purpose of performing main hoisting operations to enable the construction operations, and; providing a crane assembly according to any of the preceding embodiments arranged on the supporting structure for the purpose of performing secondary hoisting operations, for example hoisting objects substantially lighter than the maximum capacity of the main crane.

Another aspect relates to a crane assembly arranged to the removably connected to a building, in 5 particular for use in the method according to any of the preceding embodiments and examples, wherein the crane assembly comprises: a foldable crane comprising a hoisting point and a foldable crane arm rotatable around an axis of rotation, and; a supporting structure arranged for supporting the crane, wherein the supporting structure comprises a connecting mechanism for removably connecting the supporting structure to the building.

Preferably, the crane arm comprises at least one hinge axis, wherein at least one hinge axis is oriented substantially perpendicular to the axis of rotation, wherein the crane arm further comprises a telescoping function enabling the hoisting point to translate towards and away from any of the hinge points, and wherein the crane can be in a folded and an unfolded position, wherein in the folded position the hoisting point is closer to the axis of rotation than in the unfolded position, wherein the maximum lifting capacity of the crane expressed in tonnage or metric tons is less than 10, and the maximum radius by which the hoisting point can extend from the axis of rotation is 30 meters, and wherein the crane assembly does not comprise a counterweight for the purpose of compensating the moment force generated by hoisting operations performed by the crane. These characteristics may be found in existing cranes commonly referred to as “loader cranes” and/or “epsilon cranes”. Alternatively, other types of cranes may be employed in combination with the supporting structure. The crane may further comprise a base which is rotatably connected to the supporting structure, and to which the crane arm is connected. The means to rotatably connect the crane to the supporting structure may comprise a rotating platform, a bearing or a pivot, and may further be provided with a rack and pinion, wherein the rack is circular. The pinion may be powered.

The crane may comprise a rigid crane arm, commonly referred to as a “jib”, which may be rigidly or hingedly attached to a crane base, which is then rotatably or rigidly attached to the supporting structure. The crane may further comprise more arms, cables, winches and pulleys and the like to support the crane arm. The crane may also have a higher lifting capacity than 10 metric tons and/or a radius larger than 30 meters.

Preferably, the crane is remote controlled. In this way the crane can be controlled from anywhere on the construction site. In addition, the crane may be placed in a location where it is poorly accessible by a person. Preferably, the crane arm comprises at least one hydraulic cylinder.

The crane assembly may further comprise any one or more of the following: a generator to provide electric power, a device to provide hydraulic pressure such as one or more pumps, a tank for storing hydraulic fluid, a power cables to supply electric power from an external power source, a hydraulic connection to supply (pressurized) hydraulic fluid from an external source, a signal cable to allow the transmission of signals from an external controller to the crane, a receiver to receive signals for controlling the crane from an external source such as a remote control unit, a control system comprising at least one relay and/or hydraulic valve. The crane assembly may also be provided with an arrangement to allow a person to interface with the control means of the crane, such as a seat and controls.

Preferably, the supporting structure is at least 2 meters in height. This allows the crane assembly, when mounted on a floor of a building, to be used to construct walls placed on that floor, for example. In another example, concrete forms may be placed around the crane assembly, and the height of the supporting structure then ensures that the crane extends above the concrete forms. In another example, when the crane assembly is suspended through holes in a number of floors, the length of the supporting structure allows it to be connected to multiple floors at the same time, thereby increasing the stability of the crane assembly, and spreading the moment forces generated by hoisting operations performed by the crane across multiple connection points.

Preferably, the connecting mechanism comprises a plurality of connecting members to connect the supporting structure to the building, and wherein the connecting members define the outer limits of the footprint of the supporting structure.

Preferably, the footprint of the crane in the folded position is smaller than the footprint of the supporting structure. In this way, if the crane assembly is used in combination with an elevator shaft or the like, the folded crane will fit inside the elevator shaft if required. Preferably, the supporting structure is provided with connection points for hoisting the crane assembly. Preferably three or more hoisting points are provided, such that there are at least three points of support during hoisting, thereby increasing stability. The connection points for hoisting may be provided at the perimeter of the supporting structure. As a result the footprint defined by the hoisting points (connecting points for hoisting) coincides with the footprint of the supporting structure. If the footprint of the folded crane then fits inside the footprint of the hoisting points, the center of gravity of the crane falls within the footprint of the hoisting points. In this way, the crane assembly comprising the foldable crane and the supporting structure can be hoisted in one piece, as the folded crane ensures that the crane assembly remains stable during hoisting, because the center of gravity of the crane assembly falls inside the footprint of the hoisting points and the footprint of the supporting structure.

Preferably, the connecting mechanism comprises one or more brackets arranged to be removably connected to the supporting structure on at least a first side and to be removably connected to a building on at least a second side. In this way, a degree of flexibility is provided with regards to the steps taken to connect the supporting structure to a building. The connecting mechanisms, comprising brackets, may be individually connected to the building. Subsequently the supporting structure is connected to the connecting mechanisms. Alternatively, the connecting mechanisms may be connected first to the supporting structure. To connect the supporting structure to a building, the connecting mechanisms are connected to the building by means of fasteners. The connecting mechanisms may also comprise means to move the connecting points of the supporting structure and the building relative to each other. In this way, these means may allow the crane assembly to move without the use of a second crane. These means may comprise a hydraulic or mechanical jack. The connecting mechanisms may also comprise a plurality of parts which may interconnect, so that one part of the connecting mechanism may be connected to the supporting structure, and another part to the building. The supporting structure is then connected to the building by connecting the parts of the connecting mechanism to each other.

In another embodiment of the crane assembly, the connecting mechanisms are arranged to connect the supporting structure to a single substantially horizontal surface of a building, preferably a floor.

In this embodiment, the connecting mechanisms may comprise two mating surfaces perpendicular to each other, wherein one surface connects to the supporting structure and the other surface connects to the surface of the building. Alternatively, the connecting mechanisms may comprise two parallel surfaces, wherein one surface connects to the supporting structure and the other surface connects to the surface of the building. The crane assembly may be arranged such that the supporting frame rests directly on the building surface, wherein the connecting mechanisms are arranged near the sides of the supporting structure. Alternatively, the connecting mechanisms may be arranged between part of the supporting structure and the building surface. In this way, the supporting structure does not directly touch or connect with the building surface. A combination may also be arranged.

In another embodiment of the crane assembly, the connecting mechanisms are arranged to connect the supporting structure to at least two vertically separated and horizontally overlapping horizontal surfaces of a building, preferably at least two floors, wherein at least two holes are arranged in the at least two floors, wherein the at least two holes are substantially vertically aligned, wherein the supporting structure is arranged to extend through the at least two holes in the at least two floors.

The connecting mechanisms may be embodied such as described before.

The crane assembly may further comprise stabilization means. In one embodiment of the stabilization means one or more legs are arranged between the supporting structure and one or more surfaces of the building. The stabilization means may comprise one or more substantially straight legs arranged at an angle between the supporting structure and a surface of the building.

Alternatively, the legs may comprise a plurality of sections arranged at an angle to each other. In one embodiment the first segment of a leg may be oriented horizontally and outwards relative to the supporting structure. A second segment is then arranged substantially perpendicular to the first element and a surface of the building. The segments may alternatively be oriented at any other angle as is suitable for the specific requirements of the location on the building where the crane assembly is to be arranged.

In another embodiment of the crane assembly, the connecting members are arranged to connect the supporting structure to at least one substantially vertical surface of a building, for example one or more walls or one or more internal surfaces of an elevator shaft. The connecting mechanisms may be embodied such as described before.

In another embodiment of the crane assembly, at least one jacking means is arranged on the supporting structure, wherein the jacking means is arranged to drive at least one interconnecting means in a first direction relative to the supporting structure. The jacking means or system may comprise one or more mechanical jacks, hydraulic jacks, scissor jacks, bottle jacks, pneumatic jacks, or any other type of jack. The jacking system may for example comprise one or more hydraulic cylinders. The jacking system may also comprise one or more rack and pinion arrangements. The pinion may comprise a worm wheel. The jacking system may also comprise one or more telescoping members that telescope by means of one or more hydraulic actuators and/or an arrangement of cables, winches and pulleys.

Another aspect relates to a construction site comprising a building substantially under construction, at least one main tower crane or mobile crane or the like, and at least one crane assembly according to any of the preceding embodiments and examples. In this way, the main crane is used to perform primary lifting or hoisting operations, which are commonly performed as part of the construction of a building. The at least one crane assembly may then be installed in a location where hoisting operations are (to be) performed, as to perform light hoisting operations, thereby relieving the main crane. As a result, more hoisting operations per unit of time may be performed than when only the main crane is used. When fewer hoisting operations are to be performed at the location(s) where the one or more crane assemblies are installed, the crane assemblies may be disconnected and relocated to another part of the building where they may be employed. Alternatively, the one or more crane assemblies may be removed from the building site or temporarily stored until they are to be used again.

The description is further elucidated by the following figures: - Figure 1, showing an embodiment of the crane assembly mounted on a floor segment, - Figure 2, showing an embodiment of the method for moving the crane assembly from a first location to a second location, - Figures 3A-C, showing an embodiment of the crane assembly connected to and suspended through a number of floor segments, and an embodiment of the method for moving the crane assembly from a first location to a second location by means of a crane, - Figures 4A-C, showing an embodiment of the crane assembly connected to an elevator shaft and an embodiment of the method for moving the crane assembly from a first location to a second location, - Figures 5A-C, showing an embodiment of the crane assembly connected to and suspended through a number of floor segments, and an embodiment of the method for moving the crane assembly from a first location to a second location by means of a jacking system, - Figure 6, showing an embodiment of the crane assembly in combination with a slip forming system.

Figure 1 shows an embodiment of the crane assembly (1) installed on a horizontal part of a building under construction (50), preferably a floor (52). The supporting structure (2) is removably connected to the floor (50) by means of the connecting mechanisms (21) which are removably connected to the floor (50) by means of fasteners (22) such as bolts or screws or the like, A foldable crane (3) is connected to the supporting structure (2) and able to rotate around an axis A.

The foldable crane (3) comprises a crane base (37) and a crane arm (31) which may comprise more than one arm segment (36) which are connected by one or more hinges (32) to another arm segment (36) and/or to the crane base (37). The foldable crane (3) additionally comprises a hinge point (34) to which a rope, cable or chain or the like (381) may be connected to connect a load to the crane (3) through a hook (39) or other connecting means. A winch means (38) may be provided to extend or retract the cable (381) to perform a hoisting operation. One or more of the arm segments (36) may comprise a telescoping arm segment (33) enabling the hinging point (34) to translate to and from a hinge point (32). effectively making the crane arm (31) longer or shorter.

The foldable crane (3) additionally comprises one or more hydraulic cylinders (35) to move and support the crane arm segments (36). As an alternative to hydraulic cylinders other actuating means may be provided such as cables, drums and pulleys (not shown).

Figure 2 shows an embodiment of a method where the crane assembly (1) is employed in the construction of a building (50). In figure 2A the crane assembly is mounted on a horizontal surface of the building (50) such as a floor. The supporting structure (2) is connected to the floor through connecting mechanisms (21) and fasteners (22). When the crane assembly (1) is not required anymore at the location where it is installed, it may be disconnected and moved to a second location. This is shown in figure 2B, here the foldable crane (3) is folded, and the supporting structure has been disconnected from the floor. The connecting mechanisms (21) may remain connected to the supporting structure (2) or be disconnected as well. The crane assembly may then be connected to a hoisting cable of a main tower crane or the like, and hoisted to a second location.

In figure 2C the crane assembly (1) is connected to a second location on the building under construction through connecting mechanisms (21) and fasteners (22). The foldable crane (3) may be unfolded and then used to perform hoisting operations at this second location. As construction of the building (50) the crane assembly (2) may be disconnected and removed from the building site altogether to be used in a different construction project.

Figure 3A shows an embodiment of the crane assembly (1) wherein the supporting structure (2) is suspended in at least two vertically aligned openings (53) in two floor segments (521, 522) of a building under construction (50), at a height hl relative to a fixed reference such as the ground.

The supporting structure (2) is removably connected to at least two floor segments (521, 522) by means of connecting mechanisms (21) and fasteners (22). In this embodiment the foldable crane (3) is used to, among other things, support the construction of a higher floor segment (523).

In figure 3B the higher floor segment (523) nears completion. In this embodiment, the crane assembly (1) is then removably connected to floor segment (523) through connecting mechanisms (21) and fasteners (22). Subsequently, the crane assembly (1) is connected to a hoisting cable of a main tower crane or the like, and the foldable crane (3) may optionally be folded. All connecting mechanisms (21) may be disconnected from the supporting structure (2) while remaining attached to the floor segments (521, 522, 523). The crane assembly (1) is then hoisted upwards.

Alternatively, the connecting mechanisms (22) may be disconnected from the floor segments (521, 522, 523) while remaining connected to the supporting structure (2), or the connecting mechanisms (22) may be disconnected from both the supporting structure (2) and the floor segments (521, 522, 523).

In figure 3C the crane assembly (2) has been hoisted to a higher height h2. The crane assembly is then connected to at least floor segments (522, 523) by means of connecting mechanisms (22) and fasteners (21). The foldable crane (3) may then be used to construct a floor segment above floor segment (523) or alternatively for other construction activities. As the building (50) nears completion the crane assembly (1) may be disconnected from the building and used in a different construction project.

Figure 4 shows another embodiment of a method where the crane assembly (1) is used to support in the construction of a building (50). In figure 4A he supporting structure (2) is removably connected to one or more vertical surfaces (51) through connecting mechanisms (21) and fasteners (22), such as an elevator shaft, staircase, ventilation shaft or the like at a first location at height hl.

In this location the crane assembly (1) may, for example, be used in the construction of the elevator shaft or the like to which it is connected. In figure 4B an additional segment of the elevator shaft has been constructed. The crane assembly (1) may then be connected to a hoisting cable of a main tower crane or the like. The foldable crane (3) may be folded, and the connection mechanisms (21) disconnected from the supporting structure (2) and/or the vertical surface (51). The crane assembly (1) may then be hoisted to a second location at height h2 and connected to the vertical surface (51) through connecting mechanisms (21) and fasteners (22). The foldable crane (3) may be unfolded and used in subsequent construction activities. As the foldable crane (3) has a substantially lower lifting capacity than the main tower crane, it does not perform all hoisting operations, as some objects will be too heavy for the foldable crane (3) and therefore require the use of the main tower crane.

Figures 5A-C shows an embodiment of the method such as shown in figures 3A-C, but instead of using a main tower crane or the like to hoist the crane assembly (1) upwards, a jacking system (23) is used. One or more jacking systems (23) may be connected to the supporting structure (2) and to one or more connecting mechanisms (21) as shown in figure 5A. As shown in figure 5A the supporting structure (2) is connected through connecting mechanisms (21) and fasteners (22) to floor segments (521, 522). When the crane assembly (2) is prepared to be jacked up to the second location, additional connecting mechanisms may be installed to connect the supporting structure to floor segment (523) as well. In figure 5B the jacking process is shown to jack the crane assembly (1) upwards to the second location. In preparation to the jacking operation, connecting mechanisms (22) may be disconnected from the supporting structure (2), so that the supporting structure is only connected to a tloor segment (521) through the jacking systems (23) which connect the supporting structure (2) to connecting mechanisms (21) which connect to the floor segment (521) through fasteners (22). Alternatively, the connecting mechanisms (21) may be slidably connected to the supporting structure (2) to increase stability. The crane assembly (1) may then be jacked upwards to the second location. This may be achieved in a single jacking operation, wherein jacking systems (23) jack the crane assembly to the second location. The connecting mechanisms (21) may then be (rigidly) connected to the supporting structure (2) and any of the floor segments (521, 522, 523) to support the crane assembly (1) as shown in figure SC. Alternatively, the crane assembly (1) may be jacked to the second location by means of a number of smaller jacking operations. After each jacking step, the supporting structure (2) is rigidly connected to any of the floors (521, 522, 523) to allow the jacks (23) to be disconnected and reconnected at a lower location on the supporting structure (2). The jacking systems (23) may be an integral part of the supporting structure (2), or removably connected to the supporting structure (2).

Figure 6 shows an embodiment of the crane assembly (1) comprising a foldable crane (3) and a supporting structure (2) in combination with a slip forming system (60) employed to construct an elevator shaft (51) or the like. In this embodiment the supporting structure (2) is arranged on the inside of the elevator shaft (51) and removably connected to at least the elevator shaft (51) by connecting mechanisms (21) and fasteners (22) and/or to the slip forming system (60). The application of this embodiment is not limited to the construction of elevator shafts, it is applicable to any construction for which a slip forming system is employed such as silos, hollow towers, etcetera. The foldable crane (3) is arranged to fold to such a degree that the footprint of the crane is smaller than the cross section of the elevator shaft (51). As part of the slip forming process the elevator shaft (51) gradually increases in height. As such the crane assembly (1) is arranged to be disconnected from the elevator shaft (51) and/or the slip forming system (60), subsequently to be hoisted upwards and reconnected to the elevator shaft (51) through connecting mechanisms (21) and fasteners (22) and/or the slip forming system (60) at a higher position in the elevator shaft (51) and relative to the ground. In this embodiment the foldable crane (3) is, among other things, employed for performing hoisting operations of objects of lighter weight to enable the construction of the elevator shaft (50) or the like. As the foldable crane (3) has a substantially lower lifting capacity than the main tower crane, it does not perform all hoisting operations, as some objects will be too heavy for the foldable crane (3) and therefore require the use of the main tower crane.

Claims

Conclusions

1. A method of installing a crane assembly on a building under construction, comprising the steps of: - providing a collapsible crane including a lifting point and a collapsible crane arm rotatable about an axis of rotation; - providing a support structure adapted to support the crane, the support structure including a connection mechanism for releasably connecting the support structure to the building; - releasably connecting the connection mechanism of the support structure to the building at a first location; - connecting the crane to the support structure to form the crane assembly.

2. The method of claim 1, wherein the first location is at a non-zero distance from the ground.

3. The method of claim 1 or 2 further comprising the step of providing connection holes in the building, wherein the step of connecting the connection mechanism comprises releasably connecting connecting means in the connection holes.

4. Method according to at least one of the preceding claims, wherein the step of connecting comprises connecting the support structure at at least two different connection points at different heights.

5. A method according to at least one of the preceding claims, wherein the step of connecting the connecting mechanism comprises connecting to a floor structure of a building under construction.

6. A method according to at least one of the preceding claims, wherein the connecting step comprises connecting the connecting mechanism in a tubular structure in the building, such as an elevator shaft.

7. Method according to at least one of the preceding claims, further comprising the steps of:

- disconnecting the connecting mechanism from the building, and; - releasably connecting the connecting mechanism of the support structure to the building at a second location other than said first location.

8. The method of claim 7, wherein the second location is higher above the ground than the first location.

9. A method according to claim 7 or 8, wherein the first and second locations are located on the inside of an elevator shaft under construction.

10. A method according to at least one of claims 7 to 9, further comprising the step of hoisting the crane assembly from the first location to the second location by means of a second crane.

11. A method according to claim 10, wherein the second crane comprises a mobile crane or a tower crane.

12. Method according to at least one of the preceding claims 7-9, further comprising the steps of: - providing a jacking system arranged on the support structure connected to at least one connecting mechanism, and; - jacking the support structure from the first location to the second location.

13. A method according to at least one of the preceding claims 7-12, wherein the second location is directly above the first location.

14. Method according to at least one of the preceding claims, wherein the connecting mechanism is composed mainly of metal, wood and/or plastic.

15. Method of constructing a building, comprising the steps of: - providing at least one tower crane or mobile crane or the like for performing primary lifting operations to enable the construction activities, and;

- providing a crane assembly according to any one of the preceding claims for performing secondary lifting operations, for example lifting objects that are substantially lighter than the maximum capacity of the main crane.

16. A method of constructing a building, comprising the steps of: - providing a slipform system for constructing a part of the building, for example an elevator shaft, by continuous casting, the slipform system comprising a support structure arranged on the inside of the building part under construction; - providing at least one tower crane or mobile crane or the like separate from the climbing formwork system for performing primary lifting operations to enable the construction activities, and; - providing a crane assembly according to any one of the preceding claims arranged on the support structure for the purpose of performing secondary lifting operations, for example lifting objects substantially lighter than the maximum capacity of the main crane.

17. Crane assembly designed to be detachably connected to a building, in particular for use in the method according to any of the preceding claims, wherein the crane assembly comprises: - a foldable crane comprising a lifting point and a foldable crane arm rotatable about a rotation axis; - a support structure designed to support the crane, wherein the support structure comprises a connecting mechanism for detachably connecting the support structure to the building.

18. A tap assembly according to claim 17, wherein the connecting mechanism is composed mainly of metal, wood and/or plastic.

19. Crane assembly according to at least one of the preceding claims 17, 18, wherein the crane boom comprises at least one pivot axis, wherein at least one pivot axis is oriented substantially perpendicular to the axis of rotation, wherein the crane boom further comprises a telescopic function enabling the lifting point to translate to and from at least one of the pivot axes, and wherein the crane can be in a folded and unfolded position, wherein in the folded position the lifting point is closer to the axis of rotation than in the unfolded position, wherein the maximum lifting capacity of the crane expressed in tonnage is less than 10, and the maximum radius to which the lifting point can extend from the axis of rotation is 30 meters, and wherein the crane assembly does not comprise a counterweight for compensating the moment force generated by lifting operations performed by the crane.

20. Crane assembly according to at least one of the preceding claims 17-19, wherein the support structure is at least 2 metres high.

21. Crane assembly according to at least one of the preceding claims 17-20, wherein the connecting mechanism comprises a plurality of connecting bodies for connecting the support structure to the building, and wherein the connecting bodies define the outer boundaries of the footprint of the support structure.

22. Crane assembly according to at least one of the preceding claims 17-21, wherein the footprint of the crane in the folded position is smaller than the footprint of the support structure.

23. Crane assembly according to at least one of the preceding claims 17-22, wherein the connecting mechanism comprises one or more brackets adapted to be releasably connected to the support structure on at least a first side and to be releasably connected to a building on at least a second side.

24. Crane assembly according to at least one of the preceding claims 17-23, wherein the connecting mechanisms are arranged to connect the support structure to a single substantially horizontal surface of a building, preferably a floor.

25. Crane assembly according to at least one of the preceding claims 17-23, wherein the connecting mechanisms are arranged to connect the support structure to at least two vertically separated and horizontally overlapping horizontal surfaces of a building, preferably at least two floors, wherein at least two holes are provided in the at least two floors, wherein the at least two holes are substantially vertically aligned, wherein the support structure is arranged to extend through the at least two holes in the at least two floors.

26. Crane assembly according to at least one of the preceding claims 17-23, wherein the connecting bodies are arranged to connect the support structure to at least one substantially vertical surface of a building, for example one or more walls or one or more internal surfaces of a lift shaft.

27. Crane assembly according to at least one of the preceding claims 17-26, wherein at least one jacking means is arranged on the support structure, the jacking means being arranged to drive at least one connecting mechanism in a first direction relative to the support structure.

28. Construction site comprising a building substantially under construction, at least one tower crane or mobile crane or the like, and at least one crane assembly according to at least one of the preceding claims 17-27.