Technical Field

The present disclosure generally relates to a driving system for an elevator system. In particular, a driving system for driving carriages along a continuous track in an elevator system, an elevator system and a method of operating an elevator system are provided.

Background

Various types of elevator systems for vertically transporting people and/or goods are known. The Articulated Funiculator (R) is a new concept of vertical transportation which is described in WO 2013159800 A1. With this concept, two stations in a vertical building or in an underground shaft may be separated by a large distance of, for example, 100 meters.

Some prior art elevator systems employ a continuous cable to drive a passenger or load carriage along a travel path. The cable may be looped around an upper and a lower powered driving wheel. In some elevator systems, a plurality of carriages are driven with the same cable and travel along a common travel path. The passenger or load transporting efficiency of such elevator systems is poor due to its frequent stopping to load and unload carriages. It is also known to use "ropeless" elevator systems in order to provide an independent drive of the carriages, as described for example in WO 2015084370 A1. However, such ropeless elevator systems are associated with several disadvantages. For example, they require a rather

complicated control and are expensive. Summary

Accordingly, one object of the present disclosure is to provide a driving system for an elevator system, an elevator system and a method of controlling the elevator system that are simple and provide a high transportation capacity.

According to one aspect, a driving system for driving at least two carriages along a continuous track in an elevator system is provided, where the driving system comprises a first continuous elongated member forming a first driving path for driving at least one first carriage attached to the first elongated member along the track; and a second continuous elongated member forming a second driving path for driving at least one second carriage attached to the second elongated member along the track, independently of the first carriage.

The carriages may be passenger carriages and/or load carriages. For example, the carriages may be constituted by pods.

Each of the elongated members may drive one or more carriages. The carriages may be driven collectively as trains. One or several such trains may be driven by each of the elongated members.

The carriages may be permanently attached to the respective elongated member. Any suitable manner of attachment between the carriages and the elongated member may be employed.

Each carriage may be provided with an interior structure movable within an exterior structure in order to maintain the interior structure in a horizontal orientation. For example, the interior structure may rotate with respect to the exterior structure about a pitch axis to maintain

passengers standing or seated upright. Additionally, the interior structure may be configured to yaw with respect to the exterior structure of the carriage. All carriages may share the same track.

The first and second continuous elongated member may be constituted by any suitable combination of cables, wires, ropes etc. For example, the elongated members may each be constituted by a single cable or by a plurality of parallel cables. The elongated members may extend along the entire track. In case one or both of the elongated members comprise a plurality of parallel cables, these cables may be interconnected, for example by means of plate members. Since the driving system comprises two independently driven continuous elongated members each forming a driving path, the driving system comprises at least two independent driving loops.

The driving paths may be substantially parallel with each other and offset with respect to each other in a lateral direction of the track. A lateral direction of the track is a direction perpendicular to the travel direction of the track and perpendicular to a direction between a portion of the track and a carriage when the carriage is positioned on this portion of the track.

Thus, each of the first and second driving paths may be substantially aligned with the track. However, one or both of the driving paths may deviate slightly from the track at one or more portions of the track.

The first and second driving paths may adopt various types of shapes. For example, each of the first and second driving paths may form a single loop, such as a single vertically elongated loop.

Each of the first and second driving paths may also comprise two or more loops. For example, both the first and second driving paths may adopt an "8-shape" comprising two loops. Since the driving paths may be arranged adjacent to the track, the track may have a layout substantially conforming to the layout of the driving paths, for example a layout of an "8-shape". In case the driving paths comprise two or more loops, supporting wheels (or driving wheels) may be provided in crossing regions between each pair of loops to support the elongated members. At the crossing regions, the elongated members and the track are substantially horizontally oriented. A station for passengers may be arranged adjacent to each such crossing region. However, one or more stations may also, or alternatively, be provided at any vertical or inclined portions of the track.

The driving system may further comprise a first driving mechanism for driving the first elongated member and a second driving mechanism for driving the second elongated member, independently of the first elongated member.

Each of the first driving mechanism and the second driving mechanism may comprise at least one driving wheel for driving the first driving mechanism and the second driving mechanism, respectively. According to one variant, each of the first driving mechanism and the second driving mechanism comprises two driving wheels for driving the first driving mechanism and the second driving mechanism, respectively.

The two driving wheels for driving the first driving mechanism and the second driving mechanism, respectively, may be constituted by an upper and a lower driving wheel, e.g. at a vertically uppermost region and a vertically lowermost region of the respective first and second continuous elongated members. A contact surface between one of the driving wheels and one of the first continuous elongated member and the second continuous elongated member may have an angular extension of approximately 180°. The driving wheels may be the only sources of propulsion of the first and second continuous elongated members.

Each of the first and second driving mechanisms may thus comprise two wheels. For each set of wheels, at least one wheel may be powered to drive the respective elongated member. The driving force may for example be transferred from the driving mechanism to the elongated member by friction. The driving system thus constitutes a propulsion system or elevator drive for driving two elongated members each with one or more carriages attached thereto in an elevator system.

According to one variant, both driving mechanisms comprise two wheels. Two upper wheels of the driving mechanisms and two lower wheels of the driving mechanism may be rotationally supported on a common upper rotational axis and a common lower rotational axis, respectively.

The two upper wheels may be positioned adjacent to an upper region of the track and the two lower wheels may be positioned adjacent to a lower region of the track. The upper and lower regions of the track may or may not be within the same loop formed by the driving paths.

The driving system may also utilize any combination of intermediate driving mechanisms, in addition to the driving wheels, for driving the first and second elongated members. In particular, any combination of paddle members, clamping members and linear motors may be used for the intermediate driving mechanisms. These engaging mechanisms may also be employed in the first and/or the second driving mechanism.

The driving system may further comprise at least one further continuous elongated member forming at least one further driving path for driving at least one further carriage along the track, independently of the first and second carriages. For example, a third continuous elongated member forming a third driving path for driving at least one third carriage along the track, independently of the first and second carriages, may be provided. The at least one further driving path and the at least one further carriage may have a corresponding configuration as the second driving path and the at least one second carriage.

According to a further aspect, there is provided an elevator system comprising at least two carriages, a continuous track and a driving system, each according to the present disclosure. In case a plurality of first carriages are attached to the first elongated member and a plurality of second carriages are attached to the second elongated member, the first carriages and the second carriages may be alternatingly arranged along the track.

The track may include one or several rails for supporting the movement of the carriages. According to one variant, the track comprises two rails. Each carriage may comprise suitable wheel assemblies such that the carriage can roll on the rails. The track may include any combination of straight, curved, twisted and/or helical sections.

The driving paths may be provided laterally between the rails. In case two rails are used, the driving paths may be positioned within a separating distance between the rails.

Although the driving paths may be provided laterally between the rails within this separating distance, the driving paths may be arranged slightly offset (e.g. "behind" or "above") with respect to the rails. An offset direction in this regard is referred to as a direction perpendicular to the travel direction of the rails and perpendicular to the direction between the rails.

According to a further aspect, a method of operating an elevator system is provided, where the method comprises driving a first continuous elongated member such that at least one first carriage attached to the first elongated member is driven along a continuous track; and driving a second continuous elongated member independently of the first elongated member such that at least one second carriage attached to the second elongated member is driven along the track. The first and second carriages are thereby driven independently along the track.

The first elongated member and the second elongated member may be driven in an alternating manner. For example, in case a plurality of first carriages are attached to the first elongated member and a plurality of second carriages are attached to the second elongated member and the first carriages and second carriages are alternatingly arranged on the track, the first carriages may be moved along the track by driving the first elongated member while the second elongated member and the second carriages are stationary. Thus, the first carriages may be moved along the track at the same time as the second carriages are loaded unloaded (e.g. with passengers). As the first carriages arrive to a station (one or several carriages may stop at one or several stations

simultaneously), the second carriages may begin to move.

Since there might be a limited space at a station for receiving several carriages, the first carriages that has been loaded may begin to move away from the respective station slightly before the second carriages arrive at the respective station (and vice versa). Thus, the first elongated member and the second elongated member may be driven in an alternating and overlapping manner. In this driving mode, at least one of the elongated members is always driven. Alternatively, each of the first and second elongated members may be constantly driven, but at two different speeds. For example, a high speed may be used to drive carriages between stations (e.g. vertically) and a low speed may be used to drive carriages at the stations (e.g.

horizontally). A sufficiently low speed to enable passengers to enter and leave the carriages should be used in this case.

For example, each station may comprise a first position and a second position, where the second position is "downstream" of (e.g. horizontally separated from) the first position along the track. A first carriage may be driven between the first position and the second position at a station at low speed, while at the same time, a second carriage is driven between the second position of one station and a first position of another station at high speed.

The elevator system may be provided in an elevator shaft within a building and/or be provided at the exterior of the building. The elevator system may also be provided in an underground shaft to serve one or more underground stations.

Some exemplary variants are here presented as items:

1. Driving system for driving at least two carriages along a continuous track in an elevator system, the driving system comprising:

- a first continuous elongated member forming a first driving path for driving at least one first carriage attached to the first elongated member along the track; and

- a second continuous elongated member forming a second driving path for driving at least one second carriage attached to the second elongated member along the track, independently of the first carriage.

The driving system according to item 1 , wherein the driving paths are substantially parallel with each other and offset with respect to each other in a lateral direction of the track.

The driving system according to item 1 or 2, wherein each of the first and second driving paths comprises two or more loops.

The driving system according to any of the preceding items further comprises a first driving mechanism for driving the first elongated member and a second driving mechanism for driving the second elongated member, independently of the first elongated member.

The driving system according to any of the preceding items, further comprising at least one further continuous elongated member forming at least one further driving path for driving at least one further carriage along the track, independently of the first and second carriages.

Elevator system comprising at least two carriages, a continuous track and a driving system according to any of the preceding items.

The elevator system according to item 6, wherein the track comprises two rails.

The elevator system according to item 7, wherein the driving paths are provided laterally between the rails.

Method of operating an elevator system, the method comprises:

- driving a first continuous elongated member such that at least one first carriage attached to the first elongated member is driven along a continuous track; and

- driving a second continuous elongated member independently of the first elongated member such that at least one second carriage attached to the second elongated member is driven along the track. 10. The method of item 9, wherein the first elongated member and the second elongated member are driven in an alternating manner.

Brief Description of the Drawings

Further details, advantages and aspects of the present disclosure will become apparent from the following embodiments taken in conjunction with the drawings, wherein:

Fig. 1 : shows a schematic representation of an elevator system

comprising a driving system, carriages and a track; and

Fig. 2: shows a schematic representation of the driving system and the track in Fig. 1. Detailed Description

In the following, a driving system for driving carriages along a continuous track in an elevator system, an elevator system and a method of operating an elevator system will be described. The same reference numerals will be used to denote the same or similar structural features. Fig. 1 shows a schematic representation of an elevator system 10. The elevator system 10 comprises a continuous track 12 and a plurality of carriages 14, 16 on the track 12. The track 12 has a shape of a single vertically elongated loop. The elevator system 10 also comprises a driving system 18 for driving the carriages 14, 16 along the track 12. In this implementation, the carriages 14, 16 are passenger carriages in the form of pods. Each carriage 14, 16 comprises an interior structure rotationally coupled to an exterior structure such that the interior structure can pitch in order to maintain passengers within the carriages 14, 16 standing or sitting erect. Fig. 2 shows a schematic representation of the driving system 18 and the track 12 in Fig. 1. The carriages 14, 16 are omitted in Fig. 2 to improve the visibility of the driving system 18.

The track 12 comprises two substantially parallel rails 20. Accordingly, each carriage 14, 16 comprises suitable wheel assemblies such that the carriages 14, 16 can roll on the rails 20. In this implementation, each carriage 14, 16 comprises four wheel assemblies where two wheel assemblies engage each rail 20. Each wheel assembly in turn comprises six wheels where two wheels engage the upper, lower and laterally outer sides of the rail 20. A lateral direction of the track 12 is a direction parallel with the separating direction between the rails 20.

The driving system 18 further comprises a first continuous elongated member 22 and a second continuous elongated member 24. Each elongated member 22, 24 is constituted by a cable and extends along the entire track 12.

The first elongated member 22 and the second elongated member 24 form two parallel driving paths. The driving paths are offset with respect to each other in a lateral direction of the track 12. Thus, each of the first and second driving paths also adopts the shape of a single elongated loop and is substantially aligned with the track 12. The two driving paths are positioned laterally between the rails 20, i.e. within a separating distance between the rails 20.

Two first carriages 14 are attached to the first elongated member 22 and two second carriages 16 are attached to the second elongated member 24. The first and second elongated members 22, 24 are thereby configured to drive the two first carriages 14 and the two second carriages 16, respectively, along the track 12. Since the first and second elongated members 22, 24 are separated from each other, the two first carriages 14 and the two second carriages 16 are driven independently of each other along the track 12. Naturally, in this embodiment, there is a restriction in this independency since the carriages 14, 16 share the same track 12 and collisions between the carriages 14, 16 should be avoided.

The driving system 18 further comprises a first and second driving mechanism, each in the form of two driving wheels 26, 28, for driving the first and second elongated member 22, 24, respectively. The two upper driving wheels 26, 28 are provided on a common upper rotational axis 30 and two lower driving wheels 26, 28 are provided on a common lower rotational axis 32. The two upper driving wheels 26, 28 are positioned adjacent to an upper region of the track 12 and the two lower driving wheels 26, 28 are positioned adjacent to a lower region of the track 12. Two driving wheels 26, 28 and two supporting wheels 26, 28 may alternatively be used.

The first elongated member 22 is laid around the upper and lower driving wheels 26 and the second elongated member 24 is laid around the upper and lower driving wheels 28. The elongated members 22, 24 are tensioned around the respective driving wheels 26, 28 for being frictionally driven by the wheels 26, 28.

The control of the independent drive of the driving mechanisms 26, 28 may be implemented in any suitable manner. For example, an electronic control unit with signals from one or more positional sensors, indicating one or more positions of the carriages 14, 16 along the track 12, may be used.

Referring now to Fig. 1, the first carriages 14 and the second carriages 16 are alternatingly arranged on the track 12. In the state illustrated in Fig. 1 , the two first carriages 14 have stopped at an upper station and a lower station, respectively, for allowing passengers to leave and enter the first carriages 14. Thus, the first driving mechanism 26 is in a stopped state such that the first elongated member 22 is still.

At the same time, the two second carriages 16 move along the track 12 along a travel path indicated by the arrows 34. The second carriage 16 on the left hand side in Fig. 1 moves downwards and the second carriage 16 on the right hand side in Fig. 1 moves upwards due to the driving state of the second driving mechanism 28 and the consequential drive of the second elongated member 24. Since the first and second elongated members 22, 24 are used to independently drive the first carriages 14 and the second carriages 16, respectively, along the track 12, the first carriages 14 can travel between stations at the same time as the second carriages 16 are loaded and unloaded (and vice versa). This control enables an empty carriage 14, 16 to arrive at a station immediately, or within a very short time, after a previous carriage 14, 16 has left the station. Thus, passengers do not have to wait at a station for a carriage 14, 16 to arrive. Moreover, a carriage 14, 16 travelling along the track 12 does not have to stop to wait for passengers to enter or leave carriages 14, 16 at the stations. Thus, the driving system 18 according to the present disclosure provides a high passenger and load transporting efficiency.

While the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the present invention is not limited to what has been described above. For example, it will be appreciated that the dimensions of the parts may be varied as needed. Accordingly, it is intended that the present invention may be limited only by the scope of the claims appended hereto.