TECHNICAL FIELD

The invention relates to a lifting unit for installing structural elements for a building.

BACKGROUND

Suggestions have been made for making constructing buildings more effective. For example, EP2231945B1 and CA2900392C suggest improved solution for installing facade elements for multi-storey buildings. There is nevertheless a desire to make methods for constructing buildings even more effective.

SUMMARY

An object of the invention is to make methods for constructing buildings more effective.

The object is reached with a lifting unit according to claim 1. Thus, the object is reached with a lifting unit for installing structural elements for a building, having the following features: The lifting unit comprises a lifting unit structure, a lifting line, and a drum attached to the lifting unit structure and arranged to roll up the lifting line. The lifting unit comprises one or more engagement protrusions which are fixed in relation to the lifting unit structure and protrude from the lifting unit structure in a protrusion direction. The lifting unit comprises one or more locking devices. The locking devices are mounted to the lifting unit structure. The locking devices protrude from the lifting unit structure in a protrusion direction. Each of the locking devices has an elongated shape. A longitudinal direction of the respective locking device is transverse to the protrusion direction. The locking devices are arranged to be turned in relation to the lifting unit structure around respective axes that are parallel with the protrusion direction. The engagement protrusions and the locking devices preferably face in the same direction in relation to the lifting unit structure. The turning axes of the locking devices preferably extend outwards from the lifting unit structure.

The lifting unit may be used for various lifting tasks at a building site. The lifting unit may be in the form of a crane. The lifting line may be e.g. in the form of a rope or a wire. The building may be under construction. The lifting unit may also be suitable for installing structural elements of a building under renovation or extension.

By the invention, a simple manner of securing the lifting unit to another object, such as a guide element exemplified elsewhere herein, is allowed. For example, the object may be provided with an engagement slot. Thereby, the engagement protrusions may have a width, i.e. an extension transversely to the protrusion direction and to the longitudinal direction of the lifting unit structure, such that the engagement protrusions can be inserted into the engagement slot. The engagement slot may be partly formed by two flanges on opposite sides of a mouth of the engagement slot. The turning axes of the locking devices may extend in a direction of insertion of the locking devices into the engagement slot.

When the locking devices are fully inserted into the engagement slot, the locking devices may be turned. Thereby, the locking devices may extend longitudinally at least partly transversely to the longitudinal direction of the engagement slot. Thereby, ends of the locking devices may be positioned behind the slot flanges. Thereby, the lifting unit may be secured to the object.

Preferably, for turning the locking devices, the locking devices are connected to a maneuvering unit. In some embodiments, the maneuvering unit is located on a side of the lifting unit structure which is opposite to the side on which the locking devices are located. When the locking devices are being inserted into an engagement slot of an object, such as a guide element exemplified below, the maneuvering unit may be controlled so that the locking devices are aligned with a longitudinal direction of the lifting unit structure. When the locking devices are fully inserted into the engagement slot, the maneuvering unit may be moved so as to turn the locking devices. Preferably, the lifting unit comprises two or more engagement protrusions, wherein the engagement protrusions and the one or more locking devices are aligned.

Preferably, the lifting unit structure has an elongated shape, wherein the engagement protrusions are distributed in the longitudinal direction of the lifting unit structure, along at least a portion of the lifting unit structure. Preferably, the engagement protrusions are aligned in the longitudinal direction of the lifting unit structure. In some embodiments, a single lifting unit may be provided.

Preferably, the lifting unit structure has an elongated shape, wherein the one or more of the engagement protrusions are elongated and extend longitudinally in the longitudinal direction of the lifting unit structure. Thereby, the elongated engagement protrusions may be provided in the form of ridges.

Preferably, the lifting unit comprises two or more locking devices, wherein the one or more engagement protrusions and the locking devices are aligned. Thereby, a particularly secure fastening of the lifting unit to an engagement slot of another object is possible. However, in some embodiments, a single locking device is provided. Where two or more engagement protrusions are provided, each locking device is preferably located between two of the engagement protrusions.

Preferably, the lifting unit has a mass of 5-20 kg, preferably approximately 12-13 kg. Thereby, the lifting unit can be manually lifted and handled by a single adult person with normal physical capacities.

Preferably, where the lifting unit structure has an elongated shape, wherein the lifting line is arranged to extend from the drum to a line wheel at an end of the lifting unit structure. Preferably, the line wheel is arranged to be pivoted around an axis which is parallel with the lifting unit structure. The pivot axis may be perpendicular to a rotational axis of the line wheel. Thereby, where the lifting unit is mounted so as for the lifting unit structure to extend longitudinally vertically, and the line wheel is provided on the top of the lifting unit structure, the line can extend downwards from the line wheel on different sides of the tube.

The lifting unit structure may be an elongated tube. The tube may house the drum for the lifting line. The tube may have any suitable cross-section, e.g. a rectangular cross-section.

The object is also reached with a combination of a guide element, and a lifting unit according to any one of the preceding claims, wherein the engagement protrusions have a width such that the engagement protrusions can be inserted into an engagement slot in the guide element, which engagement slot is partly formed by two flanges on opposite sides of a mouth of the engagement slot, wherein the turning axes of the locking devices extend in a direction of insertion of the locking devices into the engagement slot.

The width of the engagement protrusions may be understood as the extension of the engagement protrusions transversely to the protrusion direction and to the longitudinal direction of the lifting unit structure.

The engagement slot may have a T-shaped cross-section. By positioning the lifting unit in parallel with the guide element, besides the guide element, and moving the lifting unit transversely, the engagement protrusions and the locking devices may be inserted into the engagement slot, between the flanges. When the locking devices have been inserted into the engagement slot, they may be turned so as to extend longitudinally at least partly transversely to the engagement slot. The locking devices are arranged to be turned in relation to the lifting unit structure around respective axes that extend in the direction of insertion of the locking devices into the engagement slot. Thereby, ends of the locking devices are positioned behind the flanges of the engagement slot. Thereby, the lifting unit is secured to the guide element in the transverse direction of the lifting unit.

Preferably, the guide element is arranged to be fixed such that the engagement slot extends vertically, wherein the lifting unit structure is elongated, wherein, when the lifting unit is engaged to the guide element by the engagement protrusions and the locking devices being inserted into the engagement slot, the lifting unit structure extends vertically, wherein the lifting line is arranged to extend from the drum to a line wheel at an upper end of the lifting unit structure.

As suggested, the lifting unit structure may be a tube. The tube may house the drum for the lifting line.

Preferably, where the guide element is arranged to be fixed such that the engagement slot extends vertically, the lifting unit further comprises a stop device protruding from the lifting unit structure, wherein the stop device is adapted to support the lifting unit vertically by resting on the guide element. Thereby, the lifting unit may be secured horizontally by the locking devices, and vertically by the stop device. The stop device may be arranged to rest on an upper end of the guide element. Alternatively, the stop device may be arranged to rest on another part of the guide element, such as a lateral protrusion of the guide element.

Preferably, the stop device is outwardly biased in relation to the lifting unit structure, wherein the stop device is arranged to be moved inwards in relation to the lifting unit structure by means of a disengagement device. The stop device may be outwardly biased e.g. by an elastic element, such as a spring. The disengagement device may be provided as a handle that can be pulled against the spring force acting on the stop device.

Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims, including an embodiment of a method for installing structural elements for a multi-storey building under construction.

BRIEF DESCRIPTION OF THE DRAWINGS

Below, embodiments of the invention will be described with reference to the drawings, in which:

- fig. 1 is a perspective view of a multi-storey building under construction,

- fig. 2 and fig. 3 are perspective views of an upper part of a structural element for the building in fig. 1, - fig. 4 is a flow diagram depicting steps in a method according to an embodiment of the invention,

- fig. 5 shows parts of a guide element used in the method in fig. 4, and an upper part of a structural element to which the guide element is fixed,

- fig. 6 is a side view of the guide element in fig. 5, and structural elements secured to a structure of the building in fig. 1,

- fig. 7 is a perspective view of a lifting unit fixed to the guide element in fig. 6,

- fig. 8 and fig. 9 are perspective views of the lifting unit in fig. 7, with the viewpoints being about 90 degrees apart,

- fig. 10 and fig. 11 are perspective, partly sectioned views of parts of the lifting unit in fig. 7,

- fig. 12 - fig. 15 are perspective views of further parts of the lifting unit in fig. 7, wherein fig. 12 is partly sectioned,

- fig. 16 is a perspective view of an upper end of the guide element in fig. 7, and a part of the lifting unit in fig. 7,

- fig. 16b shows a detail of fig. 15,

- fig. 17 is a perspective view of an upper end of the lifting unit in fig. 7 and a structural element for the building in fig. 1,

- fig. 18 is a side view of the guide element and the structural elements shown in fig.

6, and also the structural element and the lifting unit shown in fig. 17,

- fig. 19 is a perspective view of an upper end of the structural element in fig. 17, and a part of the lifting unit in fig. 17,

- fig. 20 is a perspective view of the guide element in fig. 18, the structural element in fig. 19, and a part of the lifting unit in fig. 19,

- fig. 21 is a side view corresponding to the side view in fig. 18, and

- fig. 22 and fig. 23 are views similar to the views in fig. 6 and fig. 21, respectively, depicting a guide element, and structural elements in a method according to an alternative embodiment of the invention. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Below, an embodiment of a method for installing structural elements for a multi-storey building 1 under construction, is described.

Reference is made to fig. 1, showing a part of a multi-storey building 1 under construction. The building comprises a building structure 101. The building structure comprises vertical loadbearing units, such as walls 131 and/or columns 132. The building structure 101 further comprises horizontal loadbearing units 142, 143, 144. The horizontal loadbearing units 142, 143, 144 may be formed by beams and/or slabs. The horizontal loadbearing units may form floors in the building. The horizontal loadbearing units carry loads to the vertical loadbearing units.

The building further comprises facade elements 134. The facade elements form vertical side surfaces of the building. The facade elements may be transparent, e.g. by glass. The facade elements may be non-transparent, e.g. by concrete.

The facade elements 134 are held between structural elements 111, 112. The structural elements 111, 112 are elongated and vertical. The structural elements 111, 112 may comprise extruded profiles, e.g. of aluminum and/or plastics. The structural elements 111, 112 may have substantially constant cross-sections. Each of the structural elements 111, 112 may have a mass of 10-40 kg, for example about 30 kg. The structural elements 111, 112 are supported by the horizontal loadbearing units 142, 143, 144. The structural elements 111, 112 form substantially vertical rows of structural elements. Vertical rows of facade elements 134 extend respectively between adjacent rows of structural elements 111, 112.

The structural elements 111, 112 are installed as described below. The facade elements 134 may be installed by being lifted with a crane 211 as illustrated in fig. 1.

Each structural element 111, 112 extends over one floor of the building. Thereby, each structural element 111, 112 extends approximately from a lower horizontal loadbearing unit 142, 143, 144 to another horizontal loadbearing unit 142, 143, 144 immediately above the lower horizontal loadbearing unit. The structural elements 111, 112 may be provided as described in EP2231945B1 or CA2900392C incorporated herein by reference.

Reference is made also to fig. 2, and fig. 3. The structural elements 111, 112 (fig. 1) are secured to the building structure via fastening members 121 which are fixed to the horizontal loadbearing units 142, 143, 144. The fastening members 121 may be provided in a variety of ways. Fig. 2 and fig. 3 show an example, from said CA2900392C, in which the fastening member 121 is adapted to be engaged with a fastening device 1111 of a structural element 111. The fastening device 1111 comprises a first fastening element 1112 adapted to engage the fastening member 121 for fastening structural element 111 to one of the horizontal loadbearing units 142. The fastening device 24 may pre-assembled to the extruded profile of the structural element 111 before delivery to the building site. The fastening member 121 comprises a vertically extending portion 1211, and the fastening device 1111 comprises a slot 1114 designed to receive the portion 1211 of the fastening member 121 thereby providing an engagement between the fastening device 1111 and the fastening member 121. In this example, the fastening device 1111 further comprises a second fastening element 1113 for fastening a facade element 134 (fig. 1) to the building structure.

Reference is made also to fig. 4. This embodiment of the method according to the invention comprises securing SI a first structural element 111 to the building structure 101 (fig. 1). This may involve allowing the first structural element 111 to engage a fastening member 121 which is fixed to one of the horizontal loadbearing units 142 of the building structure 101, e.g. as exemplified above with reference to fig. 2 and fig. 3. The horizontal loadbearing unit 142 to which the first structural element 111 is secured is here referred to as a first horizontal loadbearing unit 142. The securing of the first structural element to the building may also involve engaging a lower end of the first structural element with an upper end of a lower structural element 110 located immediately under the first structural element. This may involve the use of one or more protruding pins, or guide pins, on the upper end of the lower structural element, and/or on the lower end of the first structural element, engaging guide holes in the other of the upper end of the lower structural element and the lower end of the first structural element.

Thereafter, a guide element 201, herein also referred to as a guide pole, is fixed S2 in relation to the first structural element 111. Fig. 1 shows a plurality of guide elements 201. To the right in the figure, three guide elements are shown, fixed in relation to respective first structural elements 111. The guide element 201 has an elongated shape, wherein the guide element is oriented substantially vertically when the guide element is fixed in relation to the first structural element 111.

Reference is made also to fig. 5. The guide element 201 is mounted to the first structural element 111 externally thereof in relation to the first horizontal loadbearing unit 142. The guide element 201 comprises an extruded profile, e.g. of aluminum. The guide element 201 has a substantially constant cross-section. The guide element 201 is fixed in relation to the first structural element by a ridge 111 A with a T-shaped cross-section, on the first structural element, being introduced in a groove 201 A, also with a T-shaped cross-section, in the guide element. The ridge and the groove extend along the longitudinal directions of the first structural element and the guide element, respectively. Thereby, the guide element 201 is engaged with the first structural element 111.

Of course, alternatively the guide element 201 may be engaged with the first structural element by a ridge on the guide element being introduced in a groove in the first structural element.

Reference is made also to fig. 6. When the first structural element 111 is secured to the first horizontal loadbearing unit 142 of the building structure, there is a gap G between the first structural element 111 and the lower structural element 110 located immediately under the first structural element. The size of the gap G may be for example 1-10 cm, e.g. about 2 cm. In fig. 6 the gap is depicted as being larger for the easy of the presentation.

The guide element 201 comprises a movable and outwardly biased locking unit 2011. The locking unit 2011 could be in form of a latch. The latch could be biased by a spring. The locking unit 2011 extends into the gap G. Thereby, the guide element 201 rests on the lower structural element 110 by means of the locking unit 2011.

Thus, the guide element 201 is secured to the first structural element 111 and to the lower structural element 110 on which guide element rests by means of the locking unit 2011.

As can be seen in fig. 1 and fig. 6, the guide element 201 extends vertically past two horizontal loadbearing units 142, 143 of the building structure 101. Thus, when the guide element is fixed in relation to the first structural element Il l a part of the guide element extends above the first structural element. Thereby, a lower part of the guide element 201 extends along the first structural element, in relation to which the guide element is fixed. An upper end of the first structural element is approximately at the same level as the first horizontal loadbearing unit 142. An upper end of the guide element 201 extends a distance above the horizontal loadbearing unit 143, here referred to as a second horizontal loadbearing unit 143, which is directly above the first horizontal loadbearing unit 142.

Reference is made also to fig. 7. A lifting unit 202 is secured S3 to the guide element 201. The lifting unit 202 is fixed at the upper end of the guide element 201. The lifting unit has an elongated shape. The lifting unit 202 is mounted substantially vertically to the guide element 201.

Reference is made also to fig. 8 - fig. 14. When the lifting unit 202 is secured to the guide element 201, the lifting unit presents upper and lower ends 202U, 202L. The lifting unit 202 is in the form of a crane. The lifting unit has a mass of 5-20 kg, preferably approximately 12-13 kg. Thereby, the lifting unit can be lifted and handled by a single adult person with normal physical capacities. For example, a single person can manually secure the lifting unit 202 to the guide element 201.

The lifting unit 202 comprises a lifting unit structure 2021. In this embodiment, the lifting unit structure is in the form of an elongated tube 2021, in this example with a rectangular cross-section. The tube 2021 houses a drum 2022 (fig. 10) for a lifting line, e.g. in the form of a rope or a wire. The drum is located close to the lower end 202L of the lifting unit 202. The drum 2022 is arranged to be driven by a drive unit 2023 (fig. 11), in this example in the form of an electric motor. The drive unit is located in a drive unit housing 2023H which is fixed to the tube 2021. The drive unit 2023 is arranged to be powered by a power source, e.g. comprising a battery, located in a power source housing 2024. The drive unit is controllable by a maneuvering device 2023M, e.g. comprising a flip switch or a pair of control buttons. The maneuvering device 2023M may be mounted to the tube 2021. By maneuvering the drive unit 2023, the line can be fed in or out.

The lifting line is arranged to extend from the drum 2022 to a line wheel 2025 (fig. 12) at the upper end of the lifting unit 202. For this the line wheel 2025 has a periphery with a V- shaped cross-section. The line wheel is located in a line wheel housing 2025H. A pair of steering rolls in the tube 2021 are arranged to steer the line towards the middle of the drum.

As can be seen in fig. 12, the line wheel 2025 is arranged to guide the line 2026 from the tube 2021 to be fed out downwards. A pair of steering rolls 2025S control the position of the line in relation to the line wheel. An end of the line comprises an engagement device 2027, e.g. comprising a hook 2027H, as illustrated in fig. 14.

The line wheel comprises an elastic element, in this example in the form of a torsion spring 2025T, to keep the lifting line stretched between the line wheel 2025 and the drum 2022. The angular distance between end positions of the elastic element is sufficient to allow a desired height interval of the engagement device 2027.

A pressure roll 2025P is arranged to press the lifting line 2026 to the line wheel 2025, to avoid that the lifting line slides on the line wheel.

The line wheel 2025 is arranged to be pivoted around an axis AP which is parallel with the tube 2021. Thereby, the line 2026 can extend downwards from the line wheel on different sides of the tube 2021. As illustrated in fig. 11, a pin and groove arrangement 202P provides end stops for the pivoting motion of the line wheel 2025. As can be seen in fig. 7, when the lifting unit 202 is secured to the guide element 201, the line wheel 2025 of the lifting unit is located above an upper end of the guide element.

Reference is made also to fig. 15. The lifting unit 202 comprises three engagement protrusions 2028. In this embodiments, the engagement protrusions 2028 are in the form of ridges. The engagement protrusions protrude from the tube 2021 in a protrusion direction, indicated in fig. 15 with the arrow PD. The engagement protrusions 2028 extend in the longitudinal direction of the lifting unit 202. The engagement protrusions 2028 are aligned. The engagement protrusions 2028 are distributed in the longitudinal direction of the lifting unit, along a portion of the lifting unit. Each of two locking devices 2028L, described below, are located between two of the engagement protrusions 2028.

More generally, the lifting unit may comprise one or more engagement protrusions 2028. In some embodiments, a single lifting unit may be provided. In some embodiments, a plurality of engagement protrusions 2028 are distributed in the longitudinal direction of the lifting unit, along at least a portion of the lifting unit.

Reference is made also to fig. 16. The engagement protrusions 2028 have a width such that they can be inserted into an engagement slot 2012 in the guide element 201. In this example, the guide element 201 presents two engagement slots 2012 on opposite sides of guide element 201. Thereby, the lifting unit can be mounted on either side of the guide element 201.

Each engagement slot has a T-shaped cross-section. Thereby, the engagement slot is partly formed by two flanges 2013 on opposite sides of a mouth of the engagement slot 2012.

The locking devices 2028L protrude from the tube 2021 in the protrusion PD. By positioning the lifting unit 202 in parallel with the guide element 201, besides the guide element 201, and moving the lifting unit transversely, the engagement protrusions 2028 and the locking devices 2028L are inserted into the engagement slot 2012, between the flanges 2013. The locking devices 2028L each have an elongated shape. A longitudinal direction of each locking device is transverse to the protrusion direction PD. The locking devices 2028L are arranged to be turned around respective axes TA that extend in the direction of insertion of the locking devices 2028L into the engagement slot 2012. Thus, the turning axes TA are parallel with the protrusion direction PD. For turning the locking devices 2028L, the locking devices are connected to a maneuvering unit 2028M. In this example, the maneuvering unit 2028M is located on a side of the tube 2021 which is opposite to the side on which the locking devices 2028L are located. The maneuvering unit 2028M comprises a handle which is connected to arms via respective articulated joints. The arms are connected to torsion bars which extend through the tube 2021. The torsion bars are fixed to a respective of the locking devices 2028L.

When the locking devices 2028L are being inserted into the engagement slot 2012, the maneuvering unit 2028M is controlled so that the locking devices 2028L are aligned with the longitudinal direction of the lifting unit 202. 1.e. the longitudinal direction of each locking device is parallel to the longitudinal direction of the lifting unit 202.

Reference is made also to fig. 16b. When the locking devices 2028L are fully inserted into the engagement slot 2012, the maneuvering unit 2028M is moved so as to turn the locking devices 2028L, as indicated with the arrow ATL. Thereby, the locking devices 2028L extend longitudinally in an angle to the longitudinal direction of the engagement protrusions 2028, or to the direction of the distribution of the engagement protrusions 2028, which angle is larger than zero degrees and smaller than 180 degrees. I.e. the locking devices 2028L extend longitudinally at least partly transversely to the longitudinal direction of the engagement protrusions 2028, or to the direction of the distribution of the engagement protrusions 2028. In the example in fig. 16b, the locking devices 2028L extend longitudinally transversely to the longitudinal direction of the engagement protrusions 2028. Thereby, ends of the locking devices 2028L are positioned behind the flanges 2013. Thereby, the lifting unit 202 is secured to the guide element 201 in the transverse direction of the lifting unit. As can be seen in fig. 16, the lifting unit 202 further comprises a stop device 2029. The stop device is adapted to support the lifting unit 202 vertically by resting on the guide element 201. In this example, the stop device 2029 is adapted to rest on an upper end of the guide element 201. Alternatively, the stop device 2029 may be adapted to rest on another part of the guide element, such as a lateral protrusion of the guide element.

The maneuvering unit 2028M is arranged so that when the lifting unit is in an upright position, i.e. when it is oriented vertically with the upper end 202U above the lower end 202L, and the maneuvering unit 2028M is not held by a person, the maneuvering unit 2028M is by gravity biased to a position in which the one or more locking devices 2028L extend longitudinally at least partly transversely to the longitudinal direction of the engagement protrusions 2028, or to the direction of the distribution of the engagement protrusions 2028. Thus, when lifting unit 202 comes to rest by means of the stop device 2029, the locking devices are turned automatically when the maneuvering unit is released by the person handling the lifting unit.

For a subsequent step in the method, described below, the stop device 2029 is outwardly biased, e.g. by an elastic element, such as a spring. The stop device is arranged to be moved inwards by a disengagement device 2029D. The disengagement device 2029D is in this example provided as a handle that can be pulled against the spring force acting on the stop device 2029.

In is understood that the number of locking devices 2028L may vary from one embodiment to another. In some embodiments, the lifting unit comprises a single locking device 2028L. Thus, in general, the lifting unit comprises one or more locking devices 2028L.

As understood from fig. 7, the lifting unit 202 is mounted to the guide element 201 by a person on one of the horizontal loadbearing units 143. One or more second structural elements 112, not yet installed, are provided on the same horizontal loadbearing unit 143.

Reference is made to fig. 17. Using the lifting unit 202 secured to the guide element, a second structural element 112 is moved S4 to a desired position in relation to the first structural element 111, while the second structural element is guided by the guide element 201. For this, the engagement device 2027 (fig. 14) of the lifting unit 202 is engaged to the second structural element 112, e.g. to an engagement unit thereof.

For the engagement, the lifting line 2026 of the lifting unit is fed out of the lifting unit 202. The engagement of the engagement device 2027 of the lifting unit 202 is at the center of gravity of the second structural element 112. The second structural element 112 may be horizontal in preparation for the step of moving S4 the second structural element 112. By feeding in the lifting line, the second structural element 112 is lifted horizontally. The second structural element 112 is lifted to be above the upper end of the guide element. Thereby, the second structural element 112 is turned, e.g. manually, to a vertical position.

From the vertical position above the guide element 201, the second structural element 112 is lowered by the lifting unit 202. Thereby, a ridge with a T-shaped cross-section, on the second structural element 112, is introduced into the groove 201 A in the guide element, shown in fig. 5. The groove 201A may have a T-shaped cross-section. Thus, two flanges may form the mouth of the groove. However, at an upper end of the guide element 201, the flanges may be absent. Thereby, the introduction of the ridge into the groove may be facilitated.

As illustrated in fig. 18, while feeding out the lifting line 2026 from the lifting unit 202, the second structural element 112 is lowered S4 to the desired position in relation to the first structural element 111, while the second structural element is guided by the ridge on the second structural element 112 being introduced into the groove the guide element. Thereby, the protruding pins 1115 on the upper end of the first structural element 111 are inserted in corresponding holes provided on the lower end of the second structural element 112.

Also, by lowering the second structural element 112, the second structural element engages a fastening member 121 on the horizontal loadbearing unit 143. Thereby, the second structural element 112 is secured S5 to the building structure. A gap left between the first and second structural elements, similarly to the gap G described above. When the second structural element 112 is secured S5 to the building structure, the engagement device 2027 of the lifting unit 202 is released from the second structural element 112.

Thereafter, the vertical support of the lifting unit 202 against the guide element 201 is removed. For this the stop device 2029 shown in fig. 16 is moved inwards by the disengagement device 2029D.

Reference is made also to fig. 19. The lifting unit 202 comprises a support device 202S. The support device can also be seen in fig. 15. The support device 202S is provided as a protrusion with an extension laterally to the longitudinal direction of the lifting unit 202. The support device 202S is provided at a lower end of the lifting unit.

Upon disengagement of the stop device 2029 from the guide element 201, the support device 202S is adapted to rest on an upper end of the second structural element 112. Alternatively, the support device 202S may be adapted to rest on another part of the second structural element 112, such as a lateral protrusion of the second structural element 112.

The distance between the stop the stop device 2029 and the support device 202S, e.g. as seen in fig. 15, and the distance between the upper end of the guide element 201, on which the stop device rests 2029, and the upper end of the second structural element 112, are such that upon the disengagement of the stop device 2029 from the guide element 201, the lifting unit 202 moves a distance, which may be relatively short, downwards before the support device 202S comes into contact with the second structural element 112. During this downward movement of the lifting unit 202, the lifting unit remains transversely engaged with and guided by the guide element 201.

Thereby, the lifting unit 202 is supported S6 against the second structural element 112.

Reference is made to fig. 14 and also to fig. 20. With the lifting unit 202 supported S6 against the second structural element 112, the guide element 201 is moved S7 upwards while being guided by the second structural element 112. For this the engagement device 2027 (fig. 14) of the lifting unit 202 is secured to the guide element. In this embodiment, as can be seen in fig. 14, the engagement device 2027 comprises an engagement bracket 2027B. The engagement bracket 2027B is shaped like a plate. The engagement bracket comprises two bracket protrusions 2027P with lateral extensions on opposite sides of the engagement bracket 2027B.

Reference is made to fig. 20, and also to fig. 16. An end of the engagement bracket 2027B with the bracket protrusions 2027P is inserted into one of the engagement slots 2012 of guide element 201. For this, the flanges 2013, that partly form the engagement slot 2012 so as to have a T-shaped cross-section, are, along a distance of the engagement slot 2012, which distance may be relatively short, removed, so that the mouth of the engagement slot

2012 is widened. Thereby, a widened mouth (not shown) of the engagement slot is formed.

When the end of the engagement bracket 2027B is inserted into the engagement slot 2012, the bracket protrusions 2027P are moved through the widened mouth of the engagement slot. Thereafter, the engagement bracket 2027B is moved along the engagement slot 2012. Thereby, the bracket protrusions 2027P move away from the widened mouth of the engagement slot. Thereby, the bracket protrusions 2027P are positioned behind the flanges

2013 that partly form the engagement slot 2012. Thereby, when the lifting line 2026 of the lifting unit 202 is stretched, due to the transverse distance between the lifting line and the bracket protrusions 2027P, the bracket protrusions are biased against interior surfaces of the engagement slot 2012, whereby the bracket protrusions 2027P become fixed in the longitudinal direction of the guide element 201. In other words, the bracket protrusions 2027P is biased in a rotational direction so as to become wedged in the engagement slot 2012. When the bracket protrusions 2027P is biased in the rotational direction, it is secured to the guide element by friction. However, when the lifting line 2026 is released, the rotational bias is removed, and the engagement device 2027 is free to move downwards by gravity, with the bracket protrusions 2027P in the engagement slot 2012.

Reference is made also to fig. 21. With the engagement device 2027 engaged with the guide element 201, the guide element is lifted by means of the lifting unit 202. Thereby, the guide element is guided by the second structural element 112. Further, when the guide element is lifted by means of the lifting unit 202, the lifting unit supported laterally by the guide element 202, also while the latter moves.

As understood from fig. 21, when the guide element 201 is lifted, the locking unit 2011 is moved, by contact with the first structural element 111, against the direction in which it is outwardly biased. The locking unit may be similar to a beveled spring latch which when positioned in the gap G rests on the structural element under the first structural element and thereby prevents the guide element to move downwards. However, the guide element is allowed to be moved upwards by the spring latch being pushed out of the gap by the first structural element acting on the latch bevel.

Thereby, the locking unit 2011 can move upwards along the first structural element, until the locking unit 2011 engages the gap between the first and second structural elements 111, 112. Thereby, the guide element 201 is fixed S8 laterally to the second structural element 112 while being supported vertically on the first structural element 111. Thus, the guide element is fixed in relation to the second structural element while the guide element 201 is engaged with the second structural element 112 and resting against the first structural element 111. Thereby, a part of the guide element extends above the second structural element.

Thereafter, the lifting unit 202 is released from the guide element 201 and moved, e.g. by being carried by a person, one floor up in the building structure. Thereafter, steps described above are repeated with a third structural element. The third structural element may be provided on the floor to which the lifting unit is carried. For example, the lifting unit is secured S9 to the guide element as in step S3 described above, and the third structural element is moved S 10 to a desired position, using the lifting unit 202.

Reference is made to fig. 22. In some embodiments, the step of fixing the guide element 201 in relation to the first structural element 111 comprises securing the guide element to the first structural element only. As can be seen, thereby, the locking unit 2011 of the guide element 201 rests on top of first structural element 111. Reference is made also to fig. 23, showing the same view as in fig. 22, but with the second structural element 112 secured to the building structure. When the guide element 201 is lifted, the locking unit 2011 is moved, by contact with the second structural element 112, against the direction in which it is outwardly biased. The guide element is allowed to be moved upwards by the spring latch being pushed inwards by the second structural element acting on the latch bevel. Thereby, the locking unit 2011 can move upwards along the second structural element 112, until the locking unit 2011 reaches the top of the second structural element. There it is released outwards, and the guide element 201 can rest on top of the second structural element by means of the locking unit. Thereby, the guide element 201 is fixed laterally to the second structural element 112 while also being supported vertically on the second structural element 112.

It should be noted that the lifting unit may be used for installing a plurality of structural elements on the same level of the building structure. Thereafter, the lifting unit may be moved one floor up in the building structure.

In some embodiments, the lifting unit is adapted to be mounted to the crane 211 (fig. 1) used to install the facade elements 134, when the lifting unit is not in use. Thereby, the lifting unit and the crane may be used for installing a plurality of structural elements and a plurality of facade element on the same level of the building structure. Thereafter, the lifting unit and the crane may be moved one floor up in the building structure.

It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.