WO2017108648A1

WO2017108648A1 - Suspension means for suspending a car in a load structure of an elevator system

Info

Publication number: WO2017108648A1
Application number: PCT/EP2016/081645
Authority: WO
Inventors: Avdhut PUROHIT; Vishal BHOSALE
Original assignee: Inventio AG
Current assignee: Inventio AG
Priority date: 2015-12-23
Filing date: 2016-12-19
Publication date: 2017-06-29
Anticipated expiration: 2018-06-23

Abstract

A suspension means (7) for suspending a car (3) in a load structure (5) of an elevator system (1) is proposed. The suspension means (7) comprises a fixable support arrangement (15) for rigidly supporting the car (3) when a weight of the car (3) is carried by the fixable support arrangement (15) and an elastic support arrangement (17) for elastically supporting the car (3) when the weight of the car (3) is carried by the elastic support arrangement (17). Therein, the fixable support arrangement (15) comprises a displaceable portion (21), wherein the displaceable portion (21) is configured to, upon electric power being applied to the suspension means (7), be displaced relative to the elastic support arrangement (17) such as to get into and remain in a fixation position in which the weight of the car (3) is at least partially, preferably entirely, applied to the fixable support arrangement (15) and the displaceable portion (21) is furthermore configured to, upon an electric power loss at the suspension means (7), be automatically released and displaced relative to the elastic support arrangement (17) such as to get into a release position in which the weight of the car (3) is applied to the elastic support arrangement (17). Accordingly, upon electric power loss, the suspension arrangement (7) automatically comes into a state in which it does not support the car (3) rigidly but in an elastically damped manner. Thus, any jerks applied to the load structure (5) due to a sudden braking action as a result of the power loss will not be rigidly transmitted to the car (3).

Description

Suspension means for suspending a car in a load structure of an elevator system

The present invention relates to suspension means for suspending a car in a load structure of an elevator system.

Elevator systems are generally used for transporting persons or items within a building, preferably in a substantially vertical direction. Typically, a car may accommodate the persons or items and may be displaced within an elevator shaft. The car may be arranged within a load structure such as e.g. a car frame mechanically supporting the car. Such a load structure is sometimes referred to as mobile traction beam. Suspension traction means such as ropes or belts are generally attached to the load structure such that by driving such suspension traction means the load structure together with its car may be moved along the elevator shaft. The suspension traction means may be driven by a drive engine comprising an electric motor which, upon electric power being applied, rotates for example a traction sheave supporting and driving the suspension traction means.

However, electric power losses or failures may lead to de-energization of the drive engine's electric motor such that no motor control is possible any more. In such cases, a motor brake being provided at the motor for stopping the motor particularly in emergency cases may drop onto a brake disk, for example because the electric power failure lets a brake shoe drop onto the brake disk. Such brake disks are generally rigidly connected to the electric motor driving the traction sheave. Accordingly, upon such braking action, the traction sheave is suddenly stopped thereby also stopping the suspension traction means driven by the traction sheave. Accordingly, as the load structure is mechanically connected to the suspension traction means, the load structure may be stopped in an abrupt manner upon such braking action. As, typically, the car is mechanically connected to the load structure via a rather hard suspension, the braking action due to the electric power failure may eventually lead to a jerk stop of the elevator car. Accordingly, as a result of an electric power failure or power loss, passengers in a car may experience a significant j erk due to emergency braking. Such j erk may not only be undesirable as per requirements and/or may negatively affect a ride quality for the passengers but may also be a serious concern, especially for example for weak or senior citizens or pregnant women. Accordingly, there may be a need for means and an elevator system comprising such means wherein the means may help in avoiding significant j erks acting onto the car of the elevator system, particularly in cases of electric power failures. More specifically, there may be a need for means which, on the one hand, may help avoiding such jerks and which, on the other hand, does not negatively affect normal operation of the elevator system.

Such needs may be met with the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims and in the specification.

According to a first aspect of the present invention, a suspension means for suspending a car in a load structure of an elevator system is proposed. The suspension means comprises a fixable support arrangement and an elastic support arrangement. The fixable support arrangement is adapted and configured for rigidly supporting the car when a weight of the car is carried by the fixable support arrangement. The elastic support arrangement is adapted and configured for elastically supporting the car when the weight of the car is carried by the elastic support arrangement. Therein, the fixable support arrangement comprises a displaceable portion. The displaceable portion is configured to, upon electric power being applied to the suspension means, be displaced relative to the elastic support arrangement such as to get into and remain in a fixation position in which the weight of the car is at least partially and preferably entirely applied to the fixable support arrangement. The displaceable portion is furthermore configured to, upon an electric power loss at the suspension means, be automatically released and displaced relative to the elastic support arrangement such as to get into a release position in which the weight of the car is applied to the elastic support arrangement.

According to a second aspect of the present invention, an elevator system comprising a car in a load structure and the suspension means according to an embodiment of the first aspect of the invention is proposed. Therein, the suspension means is arranged between the car and the load structure.

Ideas underlying embodiments of the present invention may be interpreted as being based, inter alia, on the following observations and recognitions. As indicated in the above introductory portion, it may be desirable to avoid jerks acting onto an elevator car and thereby acting onto passengers within the car. For such purpose, it is proposed herein to provide the specific suspension means which may be arranged between the car and the load structure thereby suspending the car in the load structure. Therein, the suspension means may be specifically adapted and configured for mechanically "decoupling" or "isolating" the elevator car from jerks acting onto the load structure in case of an electric power failure.

More specifically, the suspension means may be adapted and configured such that, on the one hand, during normal operation (i.e. when electricity is available in the elevator system), the suspension means may provide for a relatively rigid mechanical connection between the load structure and the car, whereas, upon electric power loss, a damping, pliable, soft and/or elastic mechanical connection between the load structure and the car is established such that jerks acting onto the load structure are not directly (i.e. in a non- damped manner) transmitted onto the elevator car.

Accordingly, during normal operation, the suspension means establishes the rigid mechanical connection between the car and the load structure. In such state, the fixable support arrangement is used and controlled such that its displaceable portion is brought and/or held in the fixation position such that the weight of the car is mainly applied to the fixable support arrangement. Thus, during such normal operation, the car is rigidly connected to the load structure via the fixable support arrangement of the suspension means.

Preferably the rigid connection therefore remains, even during changing the weight of the car, for example passengers leaving or entering the car. In other words, the gap between the lower part of the load structure and the bottom of the car remains constant as the car is rigidly supported.

However, in case of an electric power loss, the displaceable portion of the fixable support arrangement is automatically released, i.e. is not held any more in the fixation position, such that the displaceable portion of the fixable support arrangement may automatically change its position relative to the elastic support arrangement. Due to such change in relative positioning between the fixable support arrangement and the elastic support arrangement, the weight of the car is not carried anymore by the fixable support arrangement but, instead, is transmitted to and carried by the elastic support arrangement.

Accordingly, as the elastic support arrangement is adapted for elastically supporting the car, upon electric power loss, the suspension means may automatically switch from a first state, in which it establishes the rigid mechanical connection between the car and the load structure, to a second state, in which it establishes an elastic, pliable and preferably damping mechanical connection between the car and the load structure.

In other words, during normal operation, i.e. while the suspension means is in the first state, the car being rigidly connected to the load structure may be precisely driven throughout the elevator shaft. Therein, the positioning of the car may be precisely controlled by controlling the positioning of the traction suspension means, this traction suspension means being driven by the drive engine and being rigidly connected to the load structure. Furthermore, during such normal operation, no unnecessary soft suspension of the car is induced thereby e.g. avoiding or suppressing undesired swaying or bouncing of the elevator car.

However, upon occurrence of an electric power loss, i.e. when the suspension means comes into its second state, the preceding rigid connection between the car and the load structure is automatically released. Such release may be induced by automatically releasing the displaceable portion of the fixable support arrangement whereby the displaceable portion displaces relative to the elastic support arrangement and away from its preceding positioning, i.e. the position of the first state. Upon such displacing of the displaceable portion being automatically induced as a result of the electric power loss, the weight of the car is not any more supported rigidly by the fixable support arrangement but, instead, is now elastically supported by the elastic support arrangement.

Accordingly, in case of an electric power loss, the suspension means automatically switches to the state in which it supports the car in an elastic and/or damping manner such that any jerks acting onto the load structure are significantly damped and/or delayed before reaching the car. According to an embodiment, the fixable support arrangement comprises a screw comprising a first threading and the displaceable portion comprises a second threading engaging with the first threading such that by turning the screw the displaceable portion may be displaced such as to get into the fixation position.

In other words, the fixable support arrangement may comprise a screw and the displaceable portion. In the displaceable portion, the second threading is provided, the windings of which cooperate with windings of the first threading provided at the screw. Accordingly, when keeping the screws position stationary in a vertical direction relative to the load structure, by turning the screw relative to the displaceable portion the displaceable portion's position may be changed. For example, the screw may be turned thereby moving the displaceable portion towards the car until the displaceable portion has reached the fixation position in which it carries the car's weight.

According to an embodiment, the displaceable portion comprises two

segments which, when cooperating with each other, form the second threading for engaging with the first threading and which, when released and separated from each other, release the engagement with the first threading.

In other words, the displaceable portion of the fixable support arrangement is not provided as a single unit but comprises at least two segments being releasable and separable from each other. These two or more segments may be positioned relative to each other and may thereby cooperate with each other in such a manner that their combination forms the second threading.

Accordingly, in the first state in which the segments cooperate with each other, the second threading formed thereby may engage with the first threading provided at the screw. Thus, in such first state, the combination of the screw and the displaceable portion together may form the fixable support arrangement in which the displaceable portion may for example directly mechanically contact the car and therefore carry the weight of the car and correspondingly occurring forces may be rigidly transmitted from the displaceable portion to the screw and through the screw finally into the supporting structure of the load structure. However, when the segments are in the second state in which they are not arranged and do not cooperate in the before described way but, instead, are released and separated from each other, the segments do not form the suitable second threading. Therefore, in such a second state, the preceding engagement between the first threading of the screw and the second threading of the displaceable portion is released. Accordingly, the screw may not hold the displaceable portion at the specific position. Particularly, the displaceable portion may not anymore be held in the fixation position. Instead, the displaceable portion automatically moves into the released position in which it does no more carry the weight of the car but this weight is, instead, carried by the elastic support arrangement.

According to an embodiment, each of the segments comprises one half of an inner threading such that, when the segments cooperate with each other, both halves together form the second threading.

In other words, the displaceable portion of the fixable support arrangement may be formed or may at least comprise two cooperating halves. The halves may be for example half cylinders which, each, have threaded inner surfaces. Each of the halves may comprise a 180°-section of an inner threading. Accordingly, by combining the two half- segments, i.e. in the specific example by combining the two half cylinders, to form an entire unit, i.e. in the specific example an entire hollow cylinder, the fixable support arrangement comprising an inner second threading may be generated such that the second threading may stably engage with the first threading of the screw as long as the two halves are kept together. Accordingly, in such configuration forces may be rigidly transmitted from the displaceable portion towards the screw. However, when the two halves are separated from each other, the inner second threading is "opened", i.e. an engagement between the second threading and the first threading is released. In such released state, forces for carrying the weight of the car may not be transmitted from the displaceable portion to the screw but instead the displaceable portion will be displaced relative to the screw and the car will slightly move until it rests onto the elastic support arrangement. Thus, by releasing the segments of the displaceable portion from each other, the fixable support arrangement may be brought in its released state and the weight of the car is then carried by the elastic support arrangement. According to an embodiment, the suspension means further comprises a pulling arrangement and a pushing arrangement. Therein, the pulling arrangement is adapted to pull the segments together, i.e. to pull the segments in a direction towards each other, such that the second threading comes into engagement with the first threading. The pushing arrangement is adapted to push the segments away from each other such that the engagement with the first threading is released.

In other words, the suspension means may comprise two counter-acting mechanisms formed by the pulling arrangement and the pushing arrangement. The pulling arrangement is adapted to generate forces onto the segments of the displaceable portion such as to force or pull these segments into the configuration in which they form the second threading for engagement with the first threading of the screw. In contrast hereto, the pushing arrangement is adapted to generate forces in an opposite direction onto the segments of the displaceable portion such as to force or push these segments into the configuration in which they release the first threading of the screw.

Therein, both of the pulling arrangement and the pushing arrangement may be active simultaneously but the action or effect of one of the two arrangements may be dominant. Alternatively, each of the pulling arrangement and the pushing arrangement may be controlled and/or activated independently from each other. This means while the pushing arrangement is active, the pulling arrangement may be deactivated, and vice versa.

For example, the pulling arrangement and the pushing arrangement may be configured such that, in normal operation of the elevator system, the action of the pulling arrangement is predominant whereas upon an electric power loss the action of the pushing arrangement is predominant. Alternatively, the pulling arrangement may be activated during normal operation of the elevator system whereas the pushing arrangement may be activated upon any electric power loss.

Accordingly, while the fixable support arrangement may be kept in its fixation position during normal operation by action of the pulling arrangement, the action of the pushing arrangement may automatically become predominant upon any electric power loss. This means, either the power loss induces a reduction in the action of the pulling arrangement or the power loss induces an increase in the action of the pushing arrangement or both. Due to such predominant action of the pushing arrangement, the engagement between the displaceable portion and the screw of the fixable support arrangement is released such that the suspension means automatically comes into the configuration in which the weight of the car is elastically carried by the elastic support arrangement.

According to an embodiment, the pulling arrangement is electrically activated.

In other words, the pulling arrangement may generate its pulling action in response to electric power being supplied to the pulling arrangement. In such implementation, an electric power supply to the pulling arrangement may be coupled to the power supply of the elevator system such that any electric power loss to the elevator system automatically also results in a power loss to the pulling arrangement thereby automatically reducing the pulling arrangement's pulling action. Specifically, the pulling arrangement may comprise an electro-magnet arrangement, i.e. may be provided with one, two or more electromagnets. For example, an electromagnet may be provided in one of the segments of the fixable support arrangement and the magnetic fields generated by the electromagnet may interact with another one of the segments of the fixable support arrangement. Preferably, electromagnets are provided at each of the segments such that when the electromagnets are supplied with electricity and the pulling arrangement is therefore electrically activated, these segments are attracted towards each other, i.e. the segments are pulled into the configuration in which the second threading formed thereby stably engages with the first threading of the screw. In an embodiment, the pushing arrangement may comprise an elastic element which mechanically presses the segments in a direction away from each other. Such elastic element may be e.g. a spring or an elastomeric member. The elastic element may be arranged intermediate to the segments, i.e. in between of the segments, such that for example one end of the elastic element interacts with the first segment and an opposite end of the elastic element interacts with the second segment.

The elastic element may be arranged and adapted such that it induces the pushing action onto the segments. As the segments are in the first configuration they cooperate to form the second threading for engagement with the screw's first threading. Accordingly, the pushing action of the elastic element tends to push the segments away from each other, i.e. to separate them. However, as long as there is no electric power loss, the pushing action of the elastic element is weaker than the pulling action of the pulling arrangement, i.e. the pulling action is predominant, such that at such normal conditions the fixable support arrangement may carry the weight of the car. However, upon electric power loss, the pulling action of the pulling arrangement is significantly reduced such that the pushing action generated by the elastic element of the pushing arrangement becomes predominant and separates the segments of the displaceable portion of the fixable support member from each other.

According to an alternative embodiment, the pushing arrangement is electrically deactivated. In other words, as long as electricity is supplied to the pushing arrangement, the pushing arrangement induces no or only weak pushing action onto the segments of the displaceable portion of the fixable support arrangement. Accordingly, in such normal operation, the pulling action generated by the pulling arrangement is predominant.

However, when electricity supply to the pushing arrangement is stopped, the pushing arrangement is activated and its pushing action becomes predominant such that the segments are separated from each other.

For example, the pushing arrangement may comprise a combination of a mechanical biasing element for generating pushing action and an electrically activated counter- force element for generating the counter-force at least partly compensating the pushing action of the biasing element. Accordingly, as long as electricity is supplied to the pushing arrangement's counter- force element, the pushing action of the pushing arrangement is kept weak or even nullified. However, when electricity supply is interrupted, the pushing arrangement induces the entire pushing action generated by the biasing element, such pushing action being sufficiently strong for separating the segments of the displaceable portion of the fixable support arrangement.

For example, according to an embodiment, the pulling arrangement comprises an elastic element which mechanically pulls the segments in a direction towards each other . Such elastic element may be a spring or an elastomeric member. The elastic element may be arranged intermediate to the segments such that for example one end of the elastic element interacts or engages with the first segment or is fixed to the first segment and an opposite end of the elastic element interacts or engages with the second segment or is fixed to the second segment.

Accordingly, the pulling arrangement may pull the segments of the displaceable portion of the fixable support arrangement towards each other due to the pulling action generated by the elastic element. During normal operation and correct electricity supply, the fixable support arrangement may therefore be kept in its fixation position. However, in case of an electricity loss, the pushing arrangement is activated and, as the pushing action of the pushing arrangement is stronger than the pulling arrangement generated by the pulling arrangement, the segments of the fixable support arrangement are automatically separated from each other thereby bringing the fixable support arrangement into its released position and therefore transmitting the weight of the car from the fixable support arrangement to the elastic support arrangement.

According to a specific embodiment, the pushing arrangement comprises a cam element which is mechanically biased such that, when the pushing arrangement is de-activated due to an electric power loss, the cam element automatically moves into a position in which it mechanically presses the segments in a direction away from each other .

The cam element may be interposed between the segments. Particularly, the cam element may have a cross-section which is rotationally asymmetric, i.e. has e.g. a non-round contour. During normal operation, the cam element may for example be arranged in a first orientation within a cavity comprised intermediate to the segments such that the cam element does not induce a significant pushing action onto the segments. However, upon electric power loss, the cam element may be automatically rotated into the second orientation in which it does no more fit into the cavity and therefore generates its pushing action and pushes the segments away from each other.

According to an embodiment, the suspension means further comprises a sensor for detecting when the displaceable portion is in its fixation position. For example, the sensor may be arranged at the displaceable portion or at the screw of the fixable support arrangement such as to detect whether or not the displaceable portion and the screw are arranged in a specific positioning relative to each other. When such positioning is detected, it may be assumed that the fixable support arrangement is correctly configured for carrying the weight of the car.

The sensor may be a mechanical sensor which is for example activated by the displaceable portion coming into its fixation position. For example, such mechanical sensor may be arranged at a top of the displaceable portion such that it is pressed against the bottom of the elevator car and thereby activated when the displaceable portion is in its fixation position. Alternatively, the sensor may be an electrical sensor in which for example an electric circuit is opened or closed upon the displaceable portion coming into its fixation position. As a further alternative, the sensor may be an optical sensor sensing the displaceable portion's correct positioning for example due to a light barrier being interrupted when the displaceable portion comes into its fixation position. Furthermore, according to other alternatives, the sensor may operate based on other operation principles such as for example a magnetic activation principle (e.g. a reed switch), a capacitive activation principle, etc.

For example, directly after an electric power loss has been finished and electric power supply has been re-assumed, the rigid mechanical connection between the car and the load structure should be re-established. For such purpose, the fixable support arrangement should be brought from its second configuration in which the displaceable portion is in its release position back to its first configuration in which the displaceable portion is in its fixation position. Accordingly, segments of the displaceable portion which have been separated during power loss have to be brought back together such as to cooperate with each other and form the second threading engaging with the screw's threading. This can be done for example by re-activating the pulling arrangement and/or reducing the pushing action of the pushing arrangement. Then, after the second threading of the displaceable portion correctly engages with the screw, the displaceable portion may be screwed into the fixation position such as to again carry the weight of the car. For such purpose, the screw may be driven for example by an individually associated electric motor or, alternatively, by a mechanism which for example transforms a motion of the load structure into the rotating force applicable to the screw. During such screwing process, the sensor may monitor the relative positioning between the screw and the displaceable portion and may for example terminate the screwing process when the displaceable portion has reached its fixation position. Accordingly, after having completed the screwing process (which may take only a few seconds or less), the suspension member has been re-established to a state in which the fixable support arrangement is brought and kept in its fixation position such that the weight of the car is rigidly supported thereby.

It shall be noted that possible features and advantages of embodiments of the invention are described herein partly with respect to a suspension means and partly with respect to an elevator system comprising such suspension means. One skilled in the art will recognize that the features may be suitably transferred from one embodiment to another and features may be modified, adapted, combined and/or replaced, etc. in order to come to further embodiments of the invention.

In the following, advantageous embodiments of the invention will be described with reference to the enclosed drawings. However, neither the drawings nor the description shall be interpreted as limiting the invention.

Fig. 1 shows an elevator system with a car in a load structure being suspended by a suspension means according to an embodiment of the present invention.

Fig. 2a and 2b show the suspension means of Fig. 1 with a fixable support arrangement being in its fixation position and its released position, respectively.

Fig. 3 shows a perspective view of a fixable support arrangement for a suspension means according to a specific embodiment of the present invention.

Fig. 4 shows a perspective explosion view of the fixable support arrangement of Fig. 3.

Fig. 5 shows a top view onto the fixable support arrangement of Fig. 3.

Fig. 6 shows a section view through the fixable support arrangement of Fig. 3 along the line A-A indicated in Fig. 5.

Fig. 7 shows a section view through the fixable support arrangement of Fig. 3 along the line B-B indicated in Fig. 5. Fig. 8 shows a section view through the fixable support arrangement of Fig. 3 along the line C-C indicated in Fig. 5.

Fig. 9 shows a perspective view of a fixable support arrangement for a suspension means according to another specific embodiment of the present invention.

Fig. 10 shows a perspective explosion view of the fixable support arrangement of Fig. 9.

Fig. 11 shows a top view onto the fixable support arrangement of Fig. 9.

Fig. 12 shows a section view through the fixable support arrangement of Fig. 9 along the line A-A indicated in Fig. 11.

Fig. 13 shows a section view through the fixable support arrangement of Fig. 9 along the line B-B indicated in Fig. 11.

Fig. 14 shows a section view through the fixable support arrangement of Fig. 9 along the line C-C indicated in Fig. 11.

The figures are only schematic and not to scale. Same reference signs refer to same or similar features.

Fig. 1 shows a car 3, a load structure 5 and a suspension means 7 forming part of an elevator system 1. The car 3 is accommodated within the load structure 5 and is mechanically connected to the load structure 5 via the suspension means 7 being interposed between a lower part 9 of the load structure 5 and a bottom 11 of the car. Accordingly, a weight of the car 3 rests on the suspension means 7 and is transmitted via the suspension means 7 to the load structure 5.

The combined weight of the car 3 and the load structure 5 is held by a suspension traction means (STM) 13 comprising one or more belts or ropes. This suspension traction means 13 may be connected to further parts of the elevator system 1 such as a drive engine driving the suspension traction means 13 via a traction sheave (not shown). The drive engine may comprise a brake which may rapidly brake a motion of the traction sheave for example in case of an emergency or an electric power loss.

However, instead of the exemplary form shown in Fig. 1, the elevator system 1 may be established in different manners in which the load structure 5 is for example not driven by suspension traction means 13 but is driven in different ways such as for example by hydraulic means. The car 3 and the load structure 5 for accommodating the car 3 may alternatively be part of a cantilever-elevator.

In order to provide, on the one hand, a rigid mechanical connection between the load structure 5 and the car 3 during normal operation of the elevator system 1 and, on the other hand, avoid undesired sudden jerks acting onto the car 3 upon sudden braking the suspension traction means 13 and the load structure 5 connected therewith in case of an electric power loss or the like, the suspension means 7 is provided in a specific manner.

Particularly, the suspension means 7 comprise a fixable support arrangement 15 and an elastic support arrangement 17. The fixable support arrangement 15 is adapted to provide a rigid mechanical connection between the load structure 5 and the car 3 in order to rigidly support the car 3 in cases where the weight of the car 3 is carried by the fixable support arrangement 15. In contrast hereto, the elastic support arrangement 17 is adapted for establishing an elastic mechanical connection between the car 3 and the load structure 5 in order to thereby elastically support the car 3 when the weight of the car 3 is carried by the elastic support arrangement 17. Whether the car 3 is supported by the fixable support arrangement 15 or by the elastic support arrangement 17 depends on a current state of the fixable support arrangement 15. As indicated by the wording "fixable", the fixable support arrangement 15 may be brought into a fixed state in which it may establish the rigid mechanical connection between the car 3 and the load structure 5 or it may be brought in a released state in which such rigid mechanical connection is released and, instead, the weight of the car 3 is carried by the elastic support arrangement 17 and, therefore, an elastic support of the car 3 is established.

Figs. 2a and 2b provide an enlarged representation of the area "A" indicated in Fig. 1. Fig. 2a shows the suspension means 7 in a first configuration in which the weight of the car 3 is rigidly supported by the fixable support means 15. Fig. 2b shows the suspension means 7 in a second configuration in which the fixable support means 15 is brought into the released state in which it does not support the bottom 11 of the car 3 but is retracted therefrom and, instead, the car 3 rests on the elastic support arrangement 17.

In the first configuration shown in Fig. 2a, a displaceable portion 21 of the fixable support arrangement 15 is arranged such as to be pressed against the bottom 11 of the car 3. For such purpose, the displaceable portion 21 comprises two segments 23 which arranged in cooperation with each other such as to engage with a screw 25. The screw 25 may be rotated by a drive motor 27 in order to thereby displace the displaceable portion 21 towards the car 3.

In the second configuration shown in Fig. 2b, the segments 23 of the displaceable portion 21 are separated, in particular slightly separated, from each other in a lateral direction. Due to such lateral spacing of the segments 23, the displaceable portion 21 is released from the screw 25 and the displaceable portion 21 may move relatively to the screw 25 and therefore relatively to the elastic support arrangement 17. Accordingly, in this second configuration, the displaceable portion 21 is moved away from the bottom 11 of the car 3 and may therefore not support the weight of the car 3 anymore. Instead, the weight is then supported by the adjacent elastic support arrangement 17.

In the example shown, the elastic support arrangement 17 is provided by a helical spring 19. The helical spring 19 is arranged coaxial to the fixable support arrangement 15, i.e. arranged such as to enclose the fixable support arrangement 15 in its inner volume.

Alternatively, the elastic support arrangement 17 may be implemented in different ways, such as e.g. with elastomer elements, and/or at different locations, such as e.g. in a space between neighbouring components of the fixable support arrangement 15. Rings 29 may help distributing and transmitting forces between the car 3, the spring 19 and the load structure 5.

The fixable support arrangement 15 and its displaceable portion 21 are specifically configured such that the displaceable portion 21 is displaceable relatively to the elastic support arrangement 17 such as to get into and remain in a fixation position, as shown in Fig. 2a, in which the weight of the car 3 is mainly applied to the fixable support arrangement 15, as long as electric power is applied to the suspension means 7. In such a first state, the segments 23 of the displaceable portion 21 are generally held in a configuration in which they cooperate with each other such that they form a second (inner) threading which stably engages with a first threading provided at the screw 25. Accordingly, by turning the screw 25 with the drive motor 27, the displaceable portion 21 may be moved towards the bottom 11 of the car 3 and may be stably and rigidly held there as soon as sufficient abutment between the displaceable portion 21 and the bottom 11 has been established.

Furthermore, the fixable support arrangement 15 and its displaceable portion 21 are specifically configured such that, upon occurrence of an electric power loss, the displaceable portion 21 is automatically released and displaced relative to the elastic support arrangement 17 such that a release position is achieved in which the weight of the car 3 rests on the elastic support arrangement 17 instead of to the rigid support arrangement 15. In such second state, i.e. when the displaceable portion 21 comes to the release position, the segments 23 of the displaceable portion 21 are separated from each other thereby releasing an engagement between the inner second threading of the displaceable portion 21 and the first threading of the screw 25.

While the elastic support arrangement 17 may be a relatively simple device such as the spring 19 or an elastomeric member being disposed in a gap between the lower part 9 of the load structure 5 and the bottom 11 of the car 3, the fixable support arrangement 15 may be a more complex device comprising several components as will be described in further detail below with reference to two different examples.

A first example of a fixable support arrangement 15 is described with reference to Figs. 3 to 8.

The fixable support arrangement 15 comprises a displaceable portion 21 formed by, inter alia, two half-cylindrical segments 23 and a screw 25. The screw 25 comprises a first threading 31 on its outer surface. Each of the half- cylindrical segments 23 comprises one half of a second threading 33 at its inner surface (see Fig. 4). The first threading 31 and the second threading 33 should be complementary such that the screw's 25 first threading 31 can engage into the segment's 23 second threading 33 when the two segments 23 are arranged in direct contact with each other such as to cooperate with each other in order to form the entire second threading 33. Accordingly, in such a condition, when turning the screw 25, a position of the displaceable portion 21 with respect to the screw 25 may be changed in a direction corresponding to a longitudinal extension direction of the screw 25.

The fixable support arrangement 15 further comprises a pulling arrangement 35 and a pushing arrangement 37. The pulling arrangement 35 is adapted to the segments 23 of the displaceable portion 21 in a direction towards each other. In contrast hereto, the pushing arrangement 37 is adapted for pushing these segments 23 in an opposite direction, i.e. away from each other.

In the presented example, the pulling arrangement 35 is formed by electromagnets 39 that can be electrically activated. Each of the electromagnets 39 comprises a coil 41 which may be supplied with electricity via wires 43. Upon an electric current being applied to the coils 41, magnetic fields are generated such that the coils 41 are attracted towards each other. As two coils 41 are arranged and fixed in a first segment 23 and two further coils 41 are arranged and fixed in the second segment 23, the pulling arrangement 35 created by these coils 41 may generate significant forces which act such as to attract the opposing segments 23 in a direction towards each other. Accordingly, upon electricity being supplied to the electromagnets 39 of the pulling arrangement 35, the segments 23 are forced into cooperation with each other and into engagement with the screw 25.

The pushing arrangement 37 is formed by elastic elements such as helical springs 45 which are arranged and configured to press the segments 23 in a direction away from each other.

Characteristics of the pushing arrangement 37 on the one hand and characteristics of the pulling arrangement 35 on the other hand are adapted in such a way that during normal operation, i.e. as long as electricity is supplied, the forces generated by the pulling arrangement 35 are predominant, i.e. the forces of the pulling arrangement 35 are stronger than the forces generated by the pushing arrangement 37.

In the specific example, this means that characteristics of the electromagnets 39 such as a dimensioning of the coils 41 and an electric current supplied to these coils 41 for normal operation are selected such that the attraction forces generated due to the magnetic fields created by the coils 41 are stronger than the opposite forces generated by the pushing arrangement's 37 springs 45. However, upon an electric power loss, the pulling arrangement 35 is deactivated, i.e. no magnetic fields are generated any more by the coils 41 so that no attraction forces are induced. Accordingly, in such a case the pushing action generated by the pushing arrangement 37 becomes predominant and pushes the opposing segments 23 away from each other.

Accordingly, the engagement between the first threading 31 of the screw 25 and the second threading 33 previously established by the cooperating segments 23 of the displaceable portion 21 is automatically released upon electric power loss. Accordingly, in such a condition, the displaceable portion 21 formed by the separated two segments 23 may be laterally displaced relatively to the screw 25 so that it does not support the car 3 anymore and, instead, the weight of the car 3 would rest onto the elastic support arrangement 17.

Thus, upon electric power loss, the rigid mechanical connection precedingly established by the suspension means 7 via its fixable support arrangement 15 is automatically and preferably instantaneously released. Thus, with the displaceable portion 21 of the fixable support arrangement 15 automatically being released, the weight of the car 3 is transmitted to the elastic support arrangement 17. Accordingly, an elastic support of the car 3 is established upon electric power failure. That means that any jerk induced to the load structure 5 due to an initiated braking action in response to the power loss is not rigidly transmitted to the car 3 but is delayed and/or damped due to the elastic support being established.

When an electricity supply is re-established after the power loss, the rigid connection between the load structure 5 and the car 3 may be quickly re-established. In such a case, an electric current is again applied to the electromagnets 39 of the pulling arrangement 35 thereby attracting the segments 23 towards each other and into cooperation with each other. Accordingly, the second threading 33 of the displaceable portion 21 is brought into engagement with the first threading 31 of the screw 25 again. Upon such engagement, the screw 25 may be rotated in order to displace the displaceable portion 21 towards the bottom 11 of the car 3 until it reaches its fixation position in which the weight of the car 3 is mainly applied to the fixable support arrangement 15. One or more sensors 47 may be provided for detecting when the displaceable portion 21 has reached its fixation position. Such a sensor 47 may apply mechanical, optical, electrical, magnetic or any other operation principles in order to sense a correct positioning of the displaceable portion 21. When the displaceable portion 21 has arrived at the fixation position, turning of the screw 25 may be terminated.

An alternative example of a fixable support arrangement 15 is described with reference to Figs. 9 to 14. Several of the structural and functional features of this example are similar to the example described according to Figs. 3 to 8 and will therefore not be described in detail again. However, the pulling arrangement 35 and the pushing arrangement 37 are achieved in a different manner.

In this case, the pulling arrangement 35 comprises an elastic element such as one or more helical springs 49 which pull the segments 23 in an attraction direction towards each other. Opposite ends of this spring 49 are attached to one of the segments 23, respectively. The spring 49 may be dimensioned and adapted such that the attracting pulling force generated thereby is sufficiently strong in order to pull the opposing segments 23 into cooperation with each other and into an engagement of the second threading 33 with the first threading 31 as long as no opposing counter- force at least partially compensates the attractive force generated by the spring 49.

The pushing arrangement 37 comprises in this case a cam element 51 which is mechanically biased such that, when the pushing arrangement 37 is deactivated (i.e. an electricity supply is interrupted), the cam element 51 automatically moves into a position in which it mechanically presses the segments 23 in a direction away from each other. For example, the cam may be mechanically biased using an elastic element such as a spring.

For such a purpose, the cam elements 51 may have e.g. an oval cross-section, i.e. a cross- section with no rotational symmetry, i.e. a rotational asymmetry. The oval cam element 51 may be placed in a recess of complementary oval cross-section, such recess being formed by two cooperating half recesses 53', 53" each being formed in one of the segments 23. During normal operation, the cam element 51 is placed in this

complementary recess and does therefore not generate any significant forces onto the segments 23. However, upon an electric power loss, a mechanism such as a biased spring is actuated which rotates the cam element 51 such that it, due to its oval cross-section, does not fit any more in the recess 53 and therefore pushes the two segments 23 in a direction away from each other. Accordingly, upon such electric power loss, engagement of the first threading 31 of the screw 25 and the second threading 33 of the displaceable portion 21 is released.

As a further possible example of a fixable support arrangement 15, the displaceable portion 21 could be established using two full hollow cylinders instead of the segments 23 of two half- cylinders shown in the examples of Figs. 3 to 14. In such an example, both cylinders may be provided with a central through-hole including a threading. During normal operation of the elevator system 1, the drive motor 27 driving the screw 25 is generally supplied with electric power such that the screw 25 is secured and locked against any rotating motion. However, in case of an electric power loss, such securing or locking may be released and the weight of the car 3 may induce a screwing down of the cylinders such that the weight of the car 3 may finally rest on the adjacent elastic support arrangement 17. Upon electricity supply being re-established, the full cylinders could be screwed upwards again, i.e. similarly as in the examples described above.

Finally, it should be noted that the term "comprising" does not exclude other elements or steps and the "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

1. Suspension means (7) for suspending a car (3) in a load structure (5) of an elevator system (1), the suspension means (7) comprising:

a fixable support arrangement (15) for rigidly supporting the car (3) when a weight of the car (3) is carried by the fixable support arrangement (15);

an elastic support arrangement (17) for elastically supporting the car (3) when the weight of the car (3) is carried by the elastic support arrangement (17);

wherein the fixable support arrangement (15) comprises a displaceable portion (21), wherein the displaceable portion (21) is configured to, upon electric power being applied to the suspension means (7), be displaced relative to the elastic support arrangement (17) such as to get into and remain in a fixation position in which the weight of the car (3) is at least partially applied to the fixable support arrangement (15) and wherein the displaceable portion (21) is furthermore configured to, upon an electric power loss at the suspension means (7), be automatically released and displaced relative to the elastic support arrangement (17) such as to get into a release position in which the weight of the car (3) is applied to the elastic support arrangement (17).

2. Suspension means of claim 1, wherein the fixable support arrangement (15) comprises a screw (25) comprising a first threading (31) and wherein the displaceable portion (21) comprises a second threading (33) engaging with the first threading (31) such that by turning the screw (25) the displaceable portion (21) may be displaced such as to get into the fixation position.

3. Suspension means of claim 2, wherein the displaceable portion (21) comprises two segments (23) which, when cooperating with each other, form the second threading (33) for engaging with the first threading (31) and which, when released and separated from each other, release the engagement with the first threading (31).

4. Suspension means of claim 3, wherein each of the segments (23) comprises one half of an inner threading such that, when the segments (23) cooperate with each other, both halves together form the second threading (33).

5. Suspension means of claim 3 or 4, further comprising a pulling arrangement (35) and a pushing arrangement (37), wherein the pulling arrangement (35) is adapted to pull the segments (23) together such that the second threading (33) comes into engagement with the first threading (31) and wherein the pushing arrangement (37) is adapted to push the segments (23) away from each other such that the engagement with the first threading (31) is released.

6. Suspension means of claim 5, wherein the pulling arrangement (35) is electrically activated.

7. Suspension means of one of claims 5 and 6, wherein the pulling arrangement (35) comprises an electro-magnet arrangement (39).

8. Suspension means of one of claims 5 to 7, wherein the pushing arrangement (37) comprises an elastic element (45) which mechanically presses the segments (23) in a direction away from each other.

9. Suspension means of claim 5, wherein the pushing arrangement (37) is electrically de-activated.

10. Suspension means of one of claims 5 and 9, wherein the pulling arrangement (35) comprises an elastic element (49) which mechanically pulls the segments (23) in a direction towards each other.

11. Suspension means of one of claims 5, 9 and 10, wherein the pushing arrangement (37) comprises a cam element (51) which is mechanically biased such that, when the pushing arrangement (37) is de-activated, the cam element (51) automatically moves into a position in which it mechanically presses the segments (23) in a direction away from each other.

12. Suspension means of one of claims 2 to 11, further comprising a sensor (47) for detecting when the displaceable portion (21) is in its fixation position.

13. Elevator system ( 1 ) comprising:

a car (3) in a load structure (5);

the suspension means (7) according to one of claims 1 to 12, the suspension means (7) being arranged between the car (3) and the load structure (5).