WO2023209268A1

WO2023209268A1 - Bolting unit, bolting carriage and method of tightening threaded fastening elements

Info

Publication number: WO2023209268A1
Application number: PCT/FI2022/050280
Authority: WO
Inventors: Harri Mäkinen; Mikael Haag; Joonas JOKELA; Markku HÄIVÄLÄ
Original assignee: Kone Corporation
Priority date: 2022-04-28
Filing date: 2022-04-28
Publication date: 2023-11-02

Abstract

The bolting unit (1) for tightening threaded fastening elements (12) that are used for fastening a guide rail (20) of an elevator to a wall of an elevator shaft comprises a body (2), a bolting tool (3) attached to the body (2), the bolting tool (3) being configured to be engaged with a threaded fastening element (12) for tightening said threaded fastening element (12), and support means (4, 8) connected to the body (2), the support means (4, 8) being configured to be engaged with a fixed structure (20, 21, 22, 23) arranged in the elevator shaft to prevent rotation of the bolting unit (1) during tightening of the threaded fastening element (12).

Description

BOLTING UNIT, BOLTING CARRIAGE AND METHOD OF TIGHTENING THREADED FASTENING ELEMENTS

Technical field of the invention

The present invention concerns a bolting unit for tightening threaded fastening elements that are used for fastening a guide rail of an elevator to a wall of an elevator shaft, as defined in claim 1 . The invention also concerns a bolting carriage comprising such a bolting unit, and a method of tightening threaded fastening elements, as defined in other claims.

Background of the invention

Most elevators are provided with vertical guide rails, which are used for guiding an elevator car and a counterweight. Often an elevator is provided with own guides rail for both the elevator car and the counterweight. The guide rails run in the vertical direction from the bottom to the top of the elevator shaft. Typically, each guide rail consists of several vertical segments. The guide rails are assembled by connecting those segments to each other on-site. A typical guide rail has a T-shaped cross-sectional profile. The arms of the profile are used for attaching the guide rail to the elevator shaft, often via guide rail brackets. The stem of the profile forms a nose that functions as support surfaces for the elevator car or the counterweight. Typically, each of the elevator car and the counterweight is supported between a pair of opposite guide rails.

The guide rail brackets can be attached to the walls of the elevator shaft by means of threaded fastening elements. Wedge anchors are commonly used for fastening the guide rail brackets. Alternatively, the walls of the elevator shaft can be provided with inserts allowing the brackets to be fastened to the wall by means of bolts. Conventionally, tightening of the fastening elements have been done manually using either a spanner or an impact driver. Especially in high-rise buildings, manual tightening of the bolts is labor-intensive and timeconsuming. Summary of the invention

An object of the present invention is to provide a bolting unit for tightening threaded fastening elements that are used for fastening a guide rail of an elevator to a wall of an elevator shaft. The characterizing features of the bolting unit are presented in claim 1 . Other objects of the invention are to provide a bolting carriage and a method for tightening threaded fastening elements. The characterizing features of the bolting carriage and the method are presented in other claims.

The bolting unit according to the invention comprises a body, a bolting tool attached to the body, the bolting tool being configured to be engaged with a threaded fastening element for tightening said threaded fastening element, and support means connected to the body, the support means being configured to be engaged with a fixed structure arranged in the elevator shaft to prevent rotation of the bolting unit during tightening of the threaded fastening element.

The bolting carriage according to the invention comprises a frame that is configured to be moveable in the vertical direction in the elevator shaft and a bolting unit defined above.

The threaded fastening elements can be, for instance, bolts. The threaded fastening elements to be tightened can be fastening elements that attach a guide rail bracket to a wall of the elevator shaft. The fastening elements could also attach the guide rail directly to the wall or to a guide rail bracket.

The support means, which can be a single support element or support unit or comprise several parts, provide for the bolting unit local support against the tightening torque of the threaded fastening elements. This allows making the carriage that moves the bolting unit lighter and using less expensive components. Also, the required tightening torque can be provided for example with a servomotor and a gear. It is thus not necessary to use an impact driver for tightening the bolts. Vibrations caused by the use of an impact driver can thus be avoided, which may increase the lifespan of the components of the bolting carriage. The invention facilitates automation of the guide rail installation. According to an embodiment of the invention, the support means comprise a slot that is configured to be engaged with a plate-shaped fixed structure.

According to an embodiment of the invention, the support means are configured to be engaged with a guide rail or a guide rail bracket. The guide rail can be the guide rail that is being fastened to the wall of the elevator shaft. Alternatively, the guide rail can be a different guide rail than the guide rail that is being fastened to the wall of the elevator shaft. Also a guide rail bracket of the different guide rail could be used as a support.

According to an embodiment of the invention, the support means comprise a first support unit and a second support unit, wherein in a use position of the bolting unit the first support unit is located in a horizontal direction on a first side of the bolting tool and the second support unit is located on a second side of the bolting tool. Typically, the guide rail is fastened to the wall by bolts arranged on both sides of the guide rail. If the guide rail is used as the fixed structure, the bolts on both sides of the guide rail can be tightened without rotating the bolting unit in between. However, the bolting unit would work also with a single support unit.

According to an embodiment of the invention, the distance between the support means and the bolting tool is configured to adapt to varying distances between the threaded fastening element and the respective fixed structure to allow tolerances in said distances. The tool can thus be used despite minor variations in the dimensions and locations of the parts of the guide rail and fastening points.

According to an embodiment of the invention, the support means or the bolting tool are slidably connected to the body and positioned by at least one spring to allow the distance between the support means and the bolting tool to adapt to a specific distance between the threaded fastening element and the respective fixed structure. The support means or the bolting tool can thus move to a limited extent against spring force to allow the tool to adapt to varying distances between the threaded fastening elements and the respective fixed structures.

According to an embodiment of the invention, the distance between the support means and the bolting tool is adjustable to allow the bolting unit to be used for tightening threaded fastening elements located at different distances from the fixed structure. For instance, the distance between the guide rail and bolts used for fastening a guide rail bracket to the wall can vary depending on the elevator. The bolting tool can thus be easily configured for different elevators.

According to an embodiment of the invention, the support means are configured to be clamped against the fixed structure. A clamping function improves the support provided by the support means.

According to an embodiment of the invention, the bolting tool comprises a tool head that is configured to be engaged with the threaded fastening elements, the tool head having an extended position and a retracted position, the tool head being spring-biased to the extended position. The spring-biased tool head allows smooth connection of the bolting tool and the threaded fastening element.

In a bolting carriage according to an embodiment of the invention, the bolting unit is configured to be moveable relative to the frame of the carriage at least in a first direction that is a horizontal direction perpendicular to the axial direction of the threaded fastening elements, and in a second direction that is parallel to the axial direction of the threaded fastening elements. The bolting tool can thus be positioned in the horizontal plane without moving the bolting carriage.

According to an embodiment of the invention, the bolting unit is connected to the frame of the carriage via at least one linear guide allowing moving of the bolting unit in the first direction, and via at least one linear guide allowing moving of the bolting unit in the second direction. As an alternative to the linear guides or in addition to them, the bolting unit could be connected to the frame via a robotic arm. The robotic arm could be configured to allow moving of the bolting unit in three directions. The robotic arm could also be configured to allow rotation of the bolting unit.

The method according to the invention comprises the steps of

- moving a bolting carriage into a vertical position, where the bolting tool can be brought by moving the bolting unit relative to the frame of the bolting carriage into a position where it can be engaged with a threaded fastening element,

- moving the bolting unit into a position, where the support means are engaged with a fixed structure in the elevator shaft,

- bringing the bolting tool into a contact with the threaded fastening element, and

- tightening the threaded fastening element using the bolting tool.

Brief

of the

Embodiments of the invention are described below in more detail with reference to the accompanying drawings, in which

Fig. 1 shows schematically an elevator shaft with two guide rails,

Fig. 2 shows a perspective view of a bolting carriage according to an embodiment of the invention,

Fig. 3 shows another view of the bolting carriage,

Fig. 4 shows a bottom view of the bolting carriage,

Fig. 5 shows part of the bolting carriage and a bolting unit according to an embodiment of the invention,

Fig. 6 shows a perspective view of the bolting unit,

Fig. 7 show a front view of the bolting unit,

Fig. 8 shows a top view of the bolting unit,

Fig. 9 shows a detail of a bolting unit according to an embodiment of the invention,

Fig. 10 shows an alternative way of using the bolting unit,

Fig. 11 shows another alternative way of using the bolting unit,

Fig. 12 shows a guide rail bracket and the bolting unit,

Fig. 13 shows an alternative construction of a guide rail bracket, and Fig. 14 shows as a flowchart the method according to the invention.

Detailed description of the invention

Figure 1 shows schematically an elevator shaft of an elevator. The elevator shaft is provided with guide rails 20. The guide rails 20 are configured to guide an elevator car (not shown) moving in the vertical direction in the elevator shaft. Similar guide rails can be provided for a counterweight of the elevator. Each guide rail 20 comprises a plurality of guide rail segments 20a. The guide rails 20 are attached to the walls of the elevator shaft by means of guide rail brackets 23. The brackets 23 are thus attached to the walls and the guide rails 20 are attached to the brackets 23. Each bracket 23 is attached to the wall by means of two or more threaded fastening elements. The threaded fastening elements can be, for instance, bolts. The guide rails 20 can be attached to the brackets 23 by means of threaded fastening elements, such as bolts and nuts.

The process of installing the guide rails 20 can be fully or partly automated. The present invention allows automation of the tightening of the bolts or other fastening elements, but also other phases of the installation process can be automated. For instance, the phase of lifting the guide rail segments 20a could be at least partly automated.

For fastening the guide rails 20 to the walls of the elevator shaft with threaded fastening elements, the walls need to be configured to cooperate with the threaded fastening elements. A typical way of fastening the guide rails 20 involves drilling holes to the walls and using wedge anchors to fasten the guide rail brackets 23. The present invention could be used for tightening the wedge anchors. However, the installation of wedge anchors is difficult to automate, and therefore the walls could be provided with threaded counterparts for the threaded fastening elements. For instance, the walls could be provided with inserts comprising holes with inside threads. The threaded fastening elements could be bolts engaged with the threads of the inserts. Alternatively, the walls could be provided with inserts having C-grooves and T-bolts arranged in the grooves. The threaded fastening elements could thus be nuts cooperating with the T-bolts. The walls could also be provided with threaded rods protruding from the walls and the threaded fastening elements could be nuts cooperating with the threaded rods. Figures 2-5 show different views of a bolting carriage 30 according to an embodiment of the invention. The bolting carriage 30 can be used for tightening threaded fastening elements 12 that are used for fastening a guide rail 20 of an elevator to a wall of an elevator shaft. The bolting carriage 30 is configured to move within the elevator shaft in the vertical direction. The bolting carriage 30 comprises a frame 32 and it is configured to carry a bolting unit 1 according to the invention. The bolting unit 1 comprises a bolting tool 3. The bolting tool 3 is for example an electrically driven tool, which tightens the threaded fastening elements 12, such as bolts.

The bolting carriage 30 is supported by one or more hoisting members 31 , such as ropes or cables. The upper end of the elevator shaft is provided with drive means, such as an electric motor, which can be used for lifting the bolting carriage 30. The bolting carriage 30 comprises wheels 33, which support the bolting carriage 30 against at least one wall of the elevator shaft. The bolting carriage 30 could be supported against two or more walls of the elevator shaft. The walls could be opposite or adjacent walls.

In the embodiment of the figures, the bolting unit 1 is configured to be moveable relative to the frame 32 of the carriage 30 in a first direction A that is a horizontal direction perpendicular to the axial direction of the threaded fastening elements 12, and in a second direction B that is parallel to the axial direction of the threaded fastening elements 12. The bolting unit 1 could be configured to be moveable relative to the frame 32 of the carriage even in the vertical direction.

In the embodiment of the figures, the bolting carriage 30 comprises linear guides 34, 35, 36, 37 for allowing moving of the bolting unit 1 in the first direction A and the second direction B. The bolting carriage 30 comprises a first pair of linear guides 34, 35. The first pair of linear guides 34, 35 allows the bolting unit 1 to be moved in the first direction A. The bolting carriage 30 further comprises a second pair of linear guides 36, 37. The second pair of linear guides 36, 37 allow the bolting unit 1 to be moved in the second direction B. In the embodiment of the figures, the first pair of linear guides 34, 35 is attached to the frame 32 of the bolting carriage 30 in a fixed manner. The second pair of linear guides 36, 37 is arranged to be moveable along the first pair of linear guides 34, 35. However, the second pair of linear guides 36, 37 could be fixed to the frame 32 and the first pair of linear guides 34, 35 could be moveable along the second pair of linear guides 36, 37.

The bolting carriage 30 comprises drive means for moving the bolting unit 1 on the linear guides 34, 35, 36, 37. The drive means could comprise, for instance, an electric motor and force transmission means. The force transmission means could comprise, for instance, a ball-race screw, chain or belt. Alternatively, the drive means could comprise a pneumatic cylinder.

The bolting carriage 30 is used for at least roughly positioning the bolting tool 3 in the vertical direction of the elevator shaft. The bolting carriage 30 is thus used for moving the bolting unit 1 to a vertical position, where the bolting tool 3 can be brought into a position where it can be engaged with a threaded fastening element 12. The vertical positioning of the bolting tool 3 can be made solely by moving the bolting carriage 30. However, the bolting unit 1 could be moveable relative to the frame 32 of the bolting carriage 30 also in the vertical direction. The bolting carriage 30 could thus be used only for rough vertical positioning, and the bolting unit 1 could then be moved in the vertical direction to position it more precisely. The moving range of the bolting unit 1 in the vertical direction could be relatively short. The movement in the vertical direction could thus be implemented, for example, by means of a lever mechanism and an electric motor and a gear or a pneumatic cylinder. However, also one or more linear guides and a pneumatic cylinder or an electric motor and force transmission means could be used.

Instead of the linear guides 34, 35, 36, 37 of the bolting carriage 30, the bolting unit 1 could be supported for example by an industrial robot attached to the frame 32 of the bolting carriage 30. The bolting carriage 30 could thus be used for roughly positioning the bolting unit 1 in the vertical direction, and the robot could be used for moving the bolting unit 1 in three dimensions to align the bolting tool 3 with a threaded fastening element 12. The robot could be in the form of a robotic arm. The robotic arm could allow rotation of the bolting unit 1 about an axis that is parallel to the second direction B. The robotic arm could be provided in addition to the linear guides or part of the linear guides. For instance, linear guides could be used for moving the robotic arm to different sides of the elevator shaft, whereas the robotic arm could position the bolting unit more precisely relative to the threaded fastening elements 12. Moving of the bolting carriage 30 can be automated. The bolting carriage 30 can be provided with means for providing spatial data relating to the position of the bolting carriage 30 in the elevator shaft and the data can be used for controlling the drive means moving the bolting carriage 30. The spatial data can indicate the absolute position of the bolting carriage 30. Alternatively, data on the relative position of the bolting carriage 30 could be used for controlling moving of the bolting carriage 30. For instance, the distance from the previous tightened bolt or other threaded fastening element could be used to control moving of the bolting carriage 30. The bolting carriage 30 could also comprise one or more sensors for locating the threaded fastening means 12, and the data from the sensors could be used for controlling moving of the bolting carriage 30.

Different views of a bolting unit 1 according to an embodiment of the invention are shown in figures 6 to 8.

The bolting unit 1 comprises a body 2, a bolting tool 3 attached to the body 2 and support means 4, 8 connected to the body 2. The bolting tool 3 is configured to be engaged with a threaded fastening element 12 for tightening the threaded fastening element 12. The support means 4, 8 are configured to be engaged with a fixed structure 20, 21 , 22, 23 arranged in the elevator shaft to prevent rotation of the bolting unit 1 during tightening of the threaded fastening elements 12.

Because of the support means 4, 8 of the bolting unit 1 , rotation of the bolting unit 1 during tightening of the fastening elements 12 is prevented. The support means 4, 8 provide local support for the bolting tool 3, which allows making the bolting carriage 30 lighter, as the supports of the bolting carriage 30 do not need to provide counter-torque for the bolting tool 3. The forces exerted on the linear guides 34, 35, 36, 37 or other structures supporting the bolting unit 1 are reduced. Also, the required tightening torque can be provided for example with a servomotor and a gear. It is thus not necessary to use an impact driver for tightening the bolts. Vibrations caused by the use of an impact driver can thus be avoided, which may increase the lifespan of the components of the bolting carriage 30. For instance, the lifetime of various sensors used in the bolting carriage 30 may increase. The bolting tool 3 can be an electrically-driven tool. The bolting tool 3 comprises a tool head 3a that is configured to be engaged with the threaded fastening element 12. In the embodiments of the figures, the tool head 3a is configured to be engaged with hexagon heads.

The fixed structure, with which the support means 4, 8 are engaged, can be a guide rail 20 or a guide rail bracket 23. In the examples of the figures, the guide rail 20 has a T-shaped cross-sectional profile. The profile has a stem 21 and arms 22. The stem 21 forms guide surfaces for the elevator car or counterweight. The arms 22 are used for fastening the guide rail 20 to the guide rail bracket 23 and further to the wall of the elevator shaft. The guide rail bracket 23 comprises plate-shaped portions.

For example figures 4 and 5 show an embodiment, where the fixed structure is the stem 21 of the guide rail 20 that is being fastened to the wall of the elevator shaft. The support means 4, 8 of the bolting unit 1 are thus engaged with the stem 21 of the guide rail 20 while the nuts 12 that are used for fastening a bracket 23 of the guide rail 20 to a wall of the elevator shaft are being tightened.

Figure 10 shows an alternative embodiment, where the fixed structure is an arm 22 of a guide rail 20. The guide rail 20, with which the support means 4, 8 of the bolting unit 1 are engaged, is a different guide rail than the guide rail 20 that is being fastened to the wall of the elevator shaft. For instance, the support means 4, 8 can be engaged with a guide rail of the elevator car while the guide rail of the counterweight is being fastened to the wall of the elevator shaft.

Figure 11 shows another alternative embodiment, where the fixed structure is a guide rail bracket 23. The guide rail bracket 23 is for a different guide rail than the guide rail that is being fastened to the wall of the elevator shaft. For instance, the support means 4, 8 can be engaged with a guide rail bracket 23 of the elevator car while the guide rail of the counterweight is being fastened to the wall of the elevator shaft.

In the embodiments of the figures, the support means comprise a first support unit 4 and a second support unit 8. The bolting unit 1 thus comprises two support units 4, 8. Each of the support units 4, 8 comprises a slot 7, 11 that is configured to be engaged with a plate-shaped fixed structure 21 , 22, 23. The plate-shaped fixed structure can be, for instance, part of a guide rail 20 or a guide rail bracket 23, as described above. The guide rail 20 can be either the guide rail 20 that is being attached to the wall of the elevator shaft or another guide rail. Instead of being provided with two support units 4, 8, the bolting unit 1 could comprise a single support unit.

In the embodiments of the figures, the first support unit 4 comprises a first support plate 5 and a second support plate 6. The slot 7 is formed between the support plates 5, 6. Similarly, the second support unit 8 comprises a first support plate 9 and a second support plate 10 and the slot 11 is formed between the support plates 9, 10. In the embodiment of figure 6, the widths of the slots 7, 11 are fixed. The width of the slot 7, 11 is configured to be slightly greater than the thickness of the fixed structure, which the support unit 4, 8 is configured to be engaged with. In the embodiments of the figures, in each pair of support plates 5, 6; 9, 10 the edges facing the opposite support plate are chamfered. This facilitates aligning of the support unit 4, 8 with the fixed structure.

In an alternative embodiment shown in figure 9, the support plates 5, 6 are moveable relative to each other to adjust the width of the slot 7 between the support plates 5, 6. The bolting unit 1 is provided with an actuator, which allows clamping the support plates 5, 6 against a fixed structure. This provides an even better support for the bolting unit 1 .

In the embodiments of the figures, in a use position of the bolting unit 1 the first support unit 4 is located in a horizontal direction on a first side of the bolting tool 3 and the second support unit 8 is located on a second side of the bolting tool 3. This facilitates the use of the bolting unit 1 when the bolting unit 1 is supported against the guide rail 20 that is being fastened to the wall of the elevator shaft. As shown for example in figures 4 and 5, each guide rail bracket 23 is attached to the wall by means of two nuts 12. The nuts 12 are located on opposite sides of the guide rail 20. The first support unit 4 can be used when tightening one of the nuts 12 and the second support unit 8 can be used when tightening the other nut 12. Because of the two support units 4, 8, the bolting unit 1 needs to be moved only linearly. However, even one support unit would be sufficient if the bolting unit 1 was rotatable about an axis that is parallel to the axial direction of the bolts 12. For instance, if the bolting unit 1 was attached to the frame 32 of the bolting carriage 30 by means of a robotic arm, the bolting unit 1 could be rotated between tightening of the two bolts 12. Alternatively, the bolting unit 12 could be provided with a mechanism and an actuator for switching a support unit to an opposite side of the bolting tool 3. Also, in some applications the fixed structures and the fastening elements could be located such that one support unit or other support means is sufficient even if the bolting unit 1 cannot be rotated.

In the embodiments of the figures, the distance between the support means 4, 8 and the bolting tool 3 is adaptable to allow tolerances in the distance between the threaded fastening element 12 and the respective fixed structure 20, 21 , 22, 23. The support units 4, 8 are slidably connected to the body 2. The first support unit 4 is supported by a first pair of guides 13, 14. The second support unit 8 is supported by a second pair of guides 15, 16. The first support unit 4 is positioned in the longitudinal direction of the first pair of guides 13, 14 by means of a pair of springs 17, 18. The second support unit 8 is positioned in the longitudinal direction of the second pair of guides 15, 16 by means of a pair of springs 24, 25. The springs 17, 18, 24, 25 allow the support units 4, 5 to move to a limited extent in the longitudinal direction of the guides. The bolting unit 1 can thus adapt to small differences in the distance between the threaded fastening element 12 and the respective fixed structure 20, 21 , 22, 23.

Instead of the pairs of guides 13, 14, 15, 16, the support units 4, 8 could be connected to the body 2 of the bolting unit 1 in many different ways. For instance, each support unit 4, 8 could be supported by a single guide. Each support unit 4, 8 could have a structure or structures cooperating with one or more grooves arranged in the body 2 of the bolting unit 1 .

Instead of the moveable support units 4, 8, the bolting tool 3 could be moveable relative to the body 2 of the bolting unit 1 . The bolting tool 3 could be supported by a pair of guides in a similar way as the support units 4, 8 in the embodiments of the figures.

In the embodiments of the figures, the positions of the first support unit 4 and the second support unit 8 are adjustable. The distance between the bolting tool 3 and each support unit 4, 8 is thus adjustable. This allows the bolting unit 1 to be used for different guide rail configurations. In the embodiments of the figures, the positions of the support units 4, 8 are manually adjustable. The body 2 of the bolting unit 1 is provided with a plurality of fastening holes 26 for allowing the springs 17, 18, 24, 25 positioning the support units 4, 8 to be positioned in different positions. Alternatively, the bolting unit 1 could be provided with actuators for adjusting the distance between the support units 4, 8 and the bolting tool 3.

The tool head 3a of the bolting tool 3 is configured to have an extended position and a retracted position. The tool head 3a is spring-biased to the extended position. When the tool head 3a is brought into contact with a threaded fastening element 12, the spring is compressed and the bolting tool 3 is protected from impacts.

Figures 12 and 13 show different guide rail brackets for which the present invention can be used. Figure 12 shows a guide rail bracket 23, which comprises slots 23a for bolts that are used for fastening the guide rail bracket 23 to the wall of the elevator shaft. The slots 23 are open from the bottom ends. The bolts 12 that are used for fastening the guide rail bracket 23 to the wall can thus be preassembled and left in a position protruding outwards from the wall. The guide rail 20 can be attached to the guide rail bracket 23 before installing the guide rail 20. The bracket 23 of a guide rail segment can be lifted to the wall and lowered so that the bolts 12 are inserted into the slots 23a. The guide rail bracket 23 and the guide rail 20 are thus supported by the bolts 12, but the bolts 12 are not tightened. Because the guide rail 20 is partially attached to the wall, the guide rail 20 can be used as a support for the tightening of the bolts 12.

Figure 13 shows an alternative configuration of the guide rail bracket 23. In figure 13, the slots 23a for the bolts 12 are not open from the bottom. The bracket 23 and the guide rail thus 20 need to be hold on the wall while the bolts 12 are inserted into the slots 23a. Alternatively, the wall can be provided with protruding threaded rods and the guide rail bracket 23 can be hung up on the rods and fastened by means of nuts. After the initial installation of the bolts/nuts, the guide rail 20 is partially attached to the wall and can be used as a support for tightening of the bolts or nuts 12.

In the method according to the invention, the bolting carriage 30 comprising the bolting unit 1 is used for tightening the threaded fastening elements 12. In a first step 101 of the method according to the invention, the bolting carriage 30 is moved to a vertical position, where the bolting tool 3 can be brought by moving the bolting unit 1 relative to the frame 32 of the bolting carriage 30 to a position where it can be engaged with a threaded fastening element 12. The moving of the bolting carriage 30 can be automated or controlled by an operator.

In a second step 102 of the method, the bolting unit 1 is moved to a position, where the support means 4, 8 are engaged with a fixed structure 20, 21 , 22, 23 in the elevator shaft. The bolting unit 1 is thus moved in the lateral direction so that the support means, for instance one of the support units 4, 8, is aligned with a guide rail 20 or a guide rail bracket 23. The bolting unit 1 is then moved so that the support means are engaged with the fixed structure.

In a third step 103 of the method, the bolting tool 3 is brought into a contact with the threaded fastening element 12. The bolting unit 1 is thus moved further in the direction in which the support means 4, 8 were engaged with the fixed structure

In a fourth step 104 of the method, the threaded fastening element is tightened using the bolting tool 3.

After the fourth step 104, the steps are repeated beginning either from the first step 101 or the second step 102. If the following fastening element 12 to be tightened is located at the same height, there is no need to move the bolting carriage 30.

It will be appreciated by a person skilled in the art that the invention is not limited to the embodiments described above, but may vary within the scope of the appended claims.

Claims

Claims:

1 . A bolting unit (1 ) for tightening threaded fastening elements (12) that are used for fastening a guide rail (20) of an elevator to a wall of an elevator shaft, the bolting unit (1 ) comprising

- a body (2),

- a bolting tool (3) attached to the body (2), the bolting tool (3) being configured to be engaged with a threaded fastening element (12) for tightening said threaded fastening element (12), and

- support means (4, 8) connected to the body (2), the support means (4, 8) being configured to be engaged with a fixed structure (20, 21 , 22, 23) arranged in the elevator shaft to prevent rotation of the bolting unit (1 ) during tightening of the threaded fastening element (12).

2. A bolting unit (1 ) according to claim 1 , wherein the support means (4, 8) comprise a slot (7, 11) that is configured to be engaged with a plateshaped fixed structure (21 , 22, 23).

3. A bolting unit (1 ) according to claim 1 or 2, wherein the support means (4, 8) are configured to be engaged with a guide rail (20) or a guide rail bracket (23).

4. A bolting unit (1 ) according to claim 3, wherein the support means (4, 8) are configured to be engaged with the guide rail (20) that is being fastened to the wall of the elevator shaft.

5. A bolting unit (1 ) according to claim 3, wherein the support means (4, 8) are configured to be engaged with a different guide rail (20) than the guide rail (20) that is being fastened to the wall of the elevator shaft, or with a guide rail bracket (23) of the different guide rail (20).

6. A bolting unit (1 ) according to any of the preceding claims, wherein the support means (4, 8) comprise a first support unit (4) and a second support unit (8), wherein in a use position of the bolting unit (1 ) the first support unit (4) is located in a horizontal direction on a first side of the bolting tool (3) and the second support unit (8) is located on a second side of the bolting tool (3). A bolting unit (1) according to any of the preceding claims, wherein the distance between the support means (4, 8) and the bolting tool (3) is configured to adapt to varying distances between the threaded fastening element (12) and the respective fixed structure (20, 21 , 22, 23) to allow tolerances in said distances. A bolting unit (1) according to claim 7, wherein the support means (4, 8) or the bolting tool (3) are slidably connected to the body (2) and positioned by at least one spring (17, 18, 24, 25) to allow the distance between the support means (4, 8) and the bolting tool (3) to adapt to a specific distance between the threaded fastening element (12) and the respective fixed structure (20, 21 , 22, 23). A bolting unit (1) according to any of the preceding claims, wherein the distance between the support means (4, 8) and the bolting tool (3) is adjustable to allow the bolting unit (1) to be used for tightening threaded fastening elements (12) located at different distances from the fixed structure (20, 21 , 22, 23). A bolting unit (1) according to any of the preceding claims, wherein the support means (4, 8) are configured to be clamped against the fixed structure (20, 21 , 22, 23). A bolting unit (1) according to any of the preceding claims, wherein the bolting tool (3) comprises a tool head (3a) that is configured to be engaged with the threaded fastening elements (12), the tool head (3a) having an extended position and a retracted position, the tool head (3a) being spring-biased to the extended position. A bolting carriage (30) for tightening threaded fastening elements (12) used for fastening a guide rail (20) of an elevator to a wall of an elevator shaft, the bolting carriage (30) comprising a frame (32) that is configured to be moveable in the vertical direction in the elevator shaft, wherein the bolting carriage (30) comprises a bolting unit (1) according to any of the preceding claims. A bolting carriage (30) according to claim 12, wherein the bolting unit (1) is configured to be moveable relative to the frame (32) of the carriage (30) at least in a first direction (A) that is a horizontal direction perpendicular to the axial direction of the threaded fastening elements (12), and in a second direction (B) that is parallel to the axial direction of the threaded fastening elements (12). A bolting carriage (30) according to claim 13, wherein the bolting unit (1 ) is connected to the frame (32) of the carriage (30) via at least one linear guide (34, 35) allowing moving of the bolting unit (1 ) in the first direction (A), and via at least one linear guide (36, 37) allowing moving of the bolting unit (1 ) in the second direction (B). A bolting carriage (30) according to claim 13 or 14, wherein the bolting unit (1 ) is connected to the frame (32) via a robotic arm. A method of tightening threaded fastening elements (12) that are used for fastening a guide rail (20) of an elevator to a wall of an elevator shaft, the method comprising the steps of

- moving a bolting carriage (30) according to any of claims 12-15 into a vertical position, where the bolting tool (3) can be brought by moving the bolting unit (1 ) relative to the frame (32) of the bolting carriage (30) into a position where it can be engaged with a threaded fastening element (12) (101 ),

- moving the bolting unit (1 ) into a position, where the support means (4, 8) are engaged with a fixed structure (20, 21 , 22, 23) in the elevator shaft (102),

- bringing the bolting tool (3) into a contact with the threaded fastening element (12) (103), and

- tightening the threaded fastening element (12) using the bolting tool (3) (104).