EP2234912B1 - Elevator system with distance control - Google Patents

Abstract

Elevator system (10) with a lower elevator cab (K1), an upper elevator cab (K2), at least one counterweight (12) and with supporting means (TA, TB) for supporting the lower and upper elevator cabs (K1, K2). The supporting means (TB) for supporting the lower elevator cab (K1) are guided sideways and downwards along the upper elevator cab (K2) in the elevator shaft (11). There are drive means for driving the lower and upper elevator cabs (K1, K2). A first incremental encoder (I1) that correlates with one of the supporting means (TB) and provides information on a change in the distance (D) between the lower and upper elevator cabs (K1, K2) is arranged on the upper elevator cab (K2).

Description

The invention relates to an elevator system with two elevator cars and with a distance control according to the preamble of claim 1.

Elevator systems of this type are known, for example from the European patent application EP-1 562 848-A1 and from the US 1805227 , The elevator system described there has two elevator cars in a common elevator shaft, each with a drive and with a common counterweight. Each of the elevator cars has its own sensors, which allow a determination of the position and speed of the elevator cars. This document is considered to be the closest prior art.

A disadvantage of this known system is, inter alia, that the security of the overall system seems to exist, but the elevator cars themselves are dependent on information of a group control device. In addition, said system seems to be relatively complicated and difficult to handle.

The object of the invention is therefore to propose an elevator system of the type mentioned, with which the disadvantages of the prior art are avoided. The object of the invention is also to propose an elevator system of the type mentioned, which offers increased security without significantly increasing the complexity of the system.

This object is achieved according to the invention for the extension system of the type mentioned by the features of the independent claim. 1

Preferred developments and details of the elevator system according to the invention are defined by the dependent claims.

Fig. 1

ein erstes bekanntes Aufzugssystem, von der Seite;

Fig. 2

ein zweites bekanntes Aufzugssystem, mit zusätzlichen Unterseilen, in gleicher Darstellung wie Fig. 1;

Fig. 3

eine schematische Darstellung eines Teils eines erfindungsgemässen Aufzugssystems, von der Seite;

Fig. 4A

eine schematische Darstellung der oberen Aufzugskabine des Aufzugssystems nach Fig. 3, von der Seite;

Fig. 4B

eine schematische Darstellung der unteren Aufzugskabine des Aufzugssystems nach Fig. 3, von der Seite;

Fig. 5

eine schematische Darstellung eines Teils eines weiteren erfindungsgemässen Aufzugssystems, von der Seite; und

Fig. 6

ein drittes erfindungsgemässes Aufzugssystem, mit Unterseilen.

Further details and advantages of the invention will be described below by way of examples and with reference to the drawings. Show it:

Fig. 1

a first known elevator system, from the side;

Fig. 2

a second known elevator system, with additional sub-ropes, in the same representation as Fig. 1 ;

Fig. 3

a schematic representation of a part of an elevator system according to the invention, from the side;

Fig. 4A

a schematic representation of the upper elevator car of the elevator system according to Fig. 3 , of the page;

Fig. 4B

a schematic representation of the lower elevator car of the elevator system according to Fig. 3 , of the page;

Fig. 5

a schematic representation of part of another elevator system according to the invention, from the side; and

Fig. 6

a third elevator system according to the invention, with sub-cables.

• Die Figuren sind nicht als massstäblich zu betrachten.
• Gleiche oder ähnliche bzw. gleich oder ähnlich wirkende konstruktive Elemente sind in allen Figuren mit gleichen Bezugszeichen versehen.
• Angaben wie rechts, links, oben, unten sind auf die jeweilige Anordnung in den Figuren bezogen.

For the drawing and the further description generally the following applies:

• The figures are not to be considered as true to scale.
• The same or similar or the same or similar acting structural elements are provided in all figures with the same reference numerals.
• Information such as right, left, top, bottom are related to the respective arrangement in the figures.

The Fig. 1 and 2 show two known elevator systems 10. These are schematic side views, with reference to which the basic elements of such elevator systems 10 are explained.

A lower elevator car K1 and an upper elevator car K2 of the elevator system 10 are located one above the other in a common elevator shaft 11. In the elevator shaft 11 is also a common counterweight 12. The counterweight 12 is at an upper counterweight Umlenkrollenanordnung 12.1 in a so-called 2: 1 Suspension suspended. The term of a counterweight deflection roller is also to be understood as meaning a roller arrangement having more than one roller. With v1 a speed of the lower elevator car K1, with v2 a speed of the upper elevator car K2 and with v3 a speed of the counterweight 12 is indicated.

In the upper region or above the actual elevator shaft 11 are drive means 9 for driving the two elevator cars K1, K2. The drive means 9 comprise a first drive arrangement for the lower elevator car K1 and a second drive arrangement for the upper elevator car K2. The corresponding motors are not shown in the drawings.

The first drive arrangement, which is associated with the lower elevator car K1, comprises a first motor and a second motor. These motors are synchronized (e.g., electric or electronic). The first motor is coupled to a first traction sheave 13.A1. The second motor is coupled to a second traction sheave 13.B1.

The second drive arrangement, which is associated with the upper elevator car K2, has a third motor. The third motor is coupled via a common shaft to a third traction sheave 13.A2 and a fourth traction sheave 13.B2. That is, in this preferred embodiment, a common motor for driving the two traction sheaves 13.A2 and 13.B2 is provided. However, two separate motors can also be used here.

The elevator system 10 further comprises a flexible support means TA, TB, which consists essentially of a first suspension element strand TA and a second suspension element strand TB. The suspension element strands TA and TB each have a first end and a second end. Advantageously, each of the suspension element strands TA and TB is formed by two or more parallel suspension element elements, for example by two belts or two steel cables. However, each suspension element line TA and TB can also comprise only one belt or one steel cable.

In the present example, the first traction sheave 13.A1 and the third traction sheave 13.A2 are assigned to the first suspension element line TA, while the second traction sheave 13.B1 and the fourth traction sheave 13.B2 are assigned to the second suspension element strand TB.

Furthermore, the elevator system 10 comprises a plurality of deflection rollers, in the present example a first deflection roller 14.A1, a second deflection roller 14.A2 for the first suspension element line TA, a third deflection roller 14.B1 for the second suspension element line TB, and a fourth deflection roller 14.AB for the two suspension element strands TA and TB.

The lower elevator car K1 has in its lower cabin area B1 a first attachment area 15.1 and a second attachment area 15.11, which are arranged laterally on opposite sides of the elevator car K1 (laterally balanced suspension).

The upper elevator car K2 has in its upper cabin area on a third mounting portion 15.2 and a fourth mounting portion 15.22, which are arranged at least approximately centrally and in the present embodiment in reality at 15.2 / 15.22 practically coincide (central suspension), wherein in Fig. 1 out For clarity of the drawing are shown with a small horizontal distance.

At the lateral attachment areas 15.1, 15.11 of the lower elevator car K1 and at the central attachment point 15.2 / 15.22 of the upper elevator car K2, the suspension element strands TA, TB are fixed, such that each of the elevator cars K1 and K2 is suspended from both suspension struts TA and TB. The elevator cars K1 and K2 are suspended in a so-called 1: 1 suspension on the suspension element strands TA and TB.

The first suspension element strand TA, starting from the first fastening point 15.1 on the lower elevator car K1, extends laterally along the elevator shaft 11 upwards. The second suspension element strand TB, starting from the second attachment point 15.11 extends laterally along the elevator shaft 11 upwards.

Fig. 2 shows a second known elevator system 10. This includes all with reference to the Fig. 1 described constructive elements and an additional device to better tension the suspension element strands TA and TB and better manage the elevator cars K1 and K2 and the counterweight 12.

The elevator system 10 according to Fig. 2 includes for this purpose a lower counterweight pulley 12.2, which is suspended from the counterweight 12. Centrally located at the lower area B1 of the lower elevator car K1 are a fifth mounting area 15.3 and a sixth mounting area 15.33, which practically coincide at 15.3 / 15.33.

At the lower area B2 of the upper elevator car K2 are laterally, on opposite sides of the elevator car K2, a seventh attachment point 15.4 and an eighth attachment point 15.44.

A flexible tensioning means SA, SB essentially consists of a first tensioning medium strand SA and a second tensioning medium strand SB. Each of the tensioner strands SA and SB has a first end and a second end. These tensioner strands SA and SB are also referred to as sub-ropes.

Furthermore, a plurality of deflecting rollers are arranged in the lower region of the elevator shaft 11. Provided are two tension rollers 16.A1, 16.A2 for the first tensioning means TA and two tensioning rollers 16.B1, 16.B2 for the second tensioning means TB. In addition, two auxiliary rollers 17.A1 and 17.A2 are provided for the first tensioning medium strand SA and two auxiliary rollers 17.B1, 17.B2 for the second tensioning medium strand SB. In addition, a biasing arrangement 16 is provided.

The first tensioning medium strand SA is fastened with its first end to the central fastening region 15.3 / 15.33 of the lower elevator car K1 and runs from there around the tensioning rollers 16.A1 and 16.A2 to the lower counterweight deflection roller 12.2. From the lower counterweight deflection roller 12.2, the first tensioning means strand SA runs via the deflection rollers 17.A1 and 17.A2 to the seventh fastening region 15.4 on the upper elevator car K2, where it is fastened by its second end.

The second tensioning medium bar SB is fastened with its first end to the central fastening area 15.3 / 15.33 of the lower elevator car K1 and runs from there around the tensioning rollers 16B1 and 16B2 to the lower counterweight deflecting roller 12.2. From the lower counterweight deflection roller 12.2, the second tensioning medium strand SA runs via the deflection rollers 17.B1 and 17.B2 to the eighth fastening region 15.44 on the upper elevator car K2, where it is fastened with its second end.

In a respect to the Fig.1 and 2 Slightly changed third elevator system 10, each elevator car K1, K2 is assigned a counterweight. In this case, the lower elevator car K1 is still hung on two suspension element strands TA, TB 1: 1. The suspension element strands TA, TB are guided laterally on the upper elevator car K2 in the upper region of the elevator shaft 11 to drive and deflection rollers and then on to the associated counterweight. This counterweight is in the upper region 1: 1 attached to the suspension element strands TA, TB. The lower elevator car also has a lower cable, which is mounted centrally on the underside and guided over a pulley arrangement in the lower region of the elevator shaft 11 to the associated counterweight and in the lower part of this counterweight 1: 1 is attached.

The upper elevator car K2 is preferably suspended centrally on its upper side at a further suspension means 1: 1. At the other end of this suspension the associated counterweight is also hung 1: 1. This second counterweight is preferably positioned relative to the counterweight of the first elevator car K1 in the elevator shaft 11. The support means of the upper elevator car K2 is guided by a further traction sheave and deflection roller, which are arranged in the upper region of the elevator shaft. Analogous to the elevator system 11 Fig.2 The upper elevator car K2 has two lower cables SA, SB, which are fastened 1: 1 in the lower region of the upper elevator car K2, and are guided laterally along the lower elevator car K2 into the lower region of the elevator shaft 11. There, the two sub-cables are directed by a pulley arrangement to the associated counterweight, where they are 1: 1 attached to the underside of the counterweight.

All elements of the exemplary elevator systems 10 that are incorporated in Fig. 1 and 2 shown or described in the third elevator system 10 are, come in the embodiments described below analogous to the application.

In Fig. 3 a partial area of an elevator system 10 according to the invention is shown. It is a side view that is 90 degrees from the views of the Fig. 1 and 2 is turned. The elevator system 10 comprises a lower elevator car K1, an upper elevator car K2 and at least one counterweight 12 (not shown). Supporting means TA, TB for supporting the lower and upper elevator cars K1, K2 are provided, the carrying means TB for carrying the lower elevator car K1 being guided laterally down the upper elevator car K2 in the elevator shaft (the walls of the elevator shaft are not shown in these figures shown). Furthermore, drive means for individually driving the lower and upper elevator cars K1, K2 are provided, but not shown. The upper elevator car K2 and the lower elevator car K1 independently move vertically in the common elevator shaft. Furthermore, the elevator system 10 comprises means for controlling the distance D between the lower and upper elevator car K1, K2. These means have vertically extending code strips C1, C2, which are mounted in the elevator shaft. A first code reader L1 is seated on the lower elevator car K1 and a second code reader L2 on the upper elevator car K2.

The code strips C1, C2 preferably have absolute position information or codes which enable the elevator cars K1, K2 to make a statement about the absolute position in the elevator shaft.

The upper elevator car K2 has at least one lower cable SA, SB which is suspended laterally from the upper elevator car K2 (at fastening points 15.4, 15.44) and which are guided laterally downwards along the lower elevator car K1 in the elevator shaft. At the upper elevator car K2 a first incremental encoder I1 is arranged, which with a support means TB for Carrying the lower elevator car K1 interacts. The first incremental encoder I1 supplies information Ir (see Fig. 4A ), which allows a statement about a change in the distance D between the lower and upper elevator car K1, K2. The information Ir is supplied to the upper elevator car K2, preferably to a safety unit S2, as in FIG Fig. 4A indicated.

At the lower elevator car K1 a second incremental encoder I2 is arranged, which interacts with a lower cable SA of the upper elevator car K2. The second incremental encoder I2 supplies information Ir (see Fig. 4B ), which allows a statement about a change in the distance D between the lower and upper elevator car K1, K2. The information Ir is supplied to the lower elevator car K1, preferably to a safety unit S1, as in FIG Fig. 4B indicated.

Thus, each of the elevator cars K1, K2 is able to determine its own absolute position (L1ist, L2ist) and speed (V1ist V2ist), which is enabled by the code readers L1, L2 and code strips C1, C2. Furthermore, each of the elevator cars K1, K2 can determine the "movement behavior" of the respective other elevator car K2, K1 by monitoring the movement of the suspension element TB or sub-cable SA of the other elevator car K2, K1 by means of the incremental encoder I1 or I2.

By observing the "movement behavior" of the respective other elevator car, e.g. the relative speed (| V1ist-V2ist |) between the two elevator cars K1, K2, or the distance change D (t) (distance as a function of the time t) are determined.

Based on the information in the FIGS. 4A and 4B Ic and Ir, each elevator car K1, K2 can make decisions and, for example, initiate braking via a speed limiter G1 or G2.

In the Fig. 3 . 4A and 4B It can be seen that one code strip C1, C2 is provided per elevator car K1, K2. But it is also possible that both elevator cars K1, K2 access the same code strip. In this case, only one code strip C is present.

The code readers L1, L2 scan the respective code strip C, C1, C2 without contact. Preferably, the scanning is optical or magnetic. The first code reader L1 supplies information Ic to a first security unit S1, which is arranged in or on the first elevator car K1. The information Ic allows a statement about the instantaneous absolute position L1ist and the instantaneous speed V1ist of the lower elevator car K1.

The second code reader L2 supplies the second safety unit S2 with information Ic on the current absolute position L2ist and the instantaneous speed V2ist of the upper elevator car S2.

As in the FIGS. 4A and 4B indicated, the lower elevator car K1 to a first security unit S1, the information Ic from the first code reader L1 and information Ir from the second incremental encoder I2 of the lower elevator car K1 receives or utilized. In Fig. 4B is schematically indicated that a first speed limiter G1 (preferably an electronic speed limiter) is provided on the lower elevator car K1, the information V1is on the instantaneous speed of the lower elevator car K1 receives. If this instantaneous speed V1is is above a preset value (Vmax), then a speed limit or braking or emergency braking may be triggered.

The upper elevator car K2 has a second safety unit S2 (see Fig. 4A ), the second security unit S2 having information Ic from the second code reader L2 and information Ir receives from the first incremental encoder I1 of the upper elevator car K2, or utilized. In Fig. 4A is indicated schematically schematically that a second speed limiter G2 (preferably an electronic speed limiter) is provided on the upper elevator car K2, the information V2ist on the instantaneous speed of the upper elevator car K2 receives. If this instantaneous speed V2is above a preset value (Vmax), then a speed limit or a braking or an emergency stop can be triggered.

Based on FIGS. 4A and 4B It can be seen that the incremental encoders I1, I2 each have at least one roller 20.1, 20.2, which interact with the passing carrying means TB or lower cable SA. Preferably, the rollers 20.1, 20.2 are friction wheels, which can be set in rotation by the respectively passing support means TB for supporting the lower elevator car K1, or by the lower cable SA of the upper elevator car K2.

At or next to at least one of the rollers 20.1, 20.2, a decoder 21, preferably an angle decoder, is provided, which detects a rotation of the roller 20.1, 20.2 and sends corresponding information Ir to the respective safety unit S1, S2 of the respective elevator car K1, K2. According to the invention, a vertical movement P (see Fig. 4A ) For example, the support means TB in a rotational movement R of the rollers 20.1, 20.2 implemented. The rotational movement R of the roller 20.1 generates 21 (angle) pulses in a decoder, which can be counted or otherwise evaluated, for example.

During commissioning or after maintenance of an elevator installation 10 according to one of FIGS. 3, 4A, 4B, preferably a memory (eg a register) in the first safety unit S1 is reset to zero. Now, if the lower cable SA of the other elevator car K2 on the Incremental encoder I2 moves over, the safety unit S1 counts or determines the increments and stores these values or this value in the memory. By reading the memory, the safety unit S1 always has information about the relative distance D (t) at time t. The information in the memory can always be overwritten with new information. If the information Ir is evaluated with respect to a time base t, a statement about the relative velocity v1 (t) -v2 (t) can be made.

At the same time, however, the code reader L1 supplies information Ic via the absolute position L1ist and, in a preferred embodiment, also via the instantaneous speed V1is in the elevator shaft, independently of the incremental encoder I2.

• absolute Position L1ist,
• relativer Abstand D(t),
• Relativgeschwindigkeit v1(t)-v2(t).

In a preferred embodiment, the security unit S1 has the following information:

• absolute position L1ist,
• relative distance D (t),
• Relative velocity v1 (t) -v2 (t).

On the basis of this and possibly further information and taking into account specifiable rules (or algorithms), the safety unit S1 can set the "movement behavior" of the lower elevator car K1 in relation to the "movement behavior" of the upper elevator car K2. By means of rules (or algorithms) decisions can be made and reactions can be triggered. Thus, for example, the speed of the lower elevator car K1 can be reduced by means of the speed limiter G1 located there, if V1is> Vmax.

According to the invention, the safety unit S2 of the upper elevator car K2 is able to independently determine the relative speed v1 (t) -v2 (t) by observing the carrying means TB passing by. By means of the code reader L2 and the interaction (Scanning) of the code strip C2, the safety unit S2 on the one hand, the absolute position L2ist and in a preferred embodiment, the own speed v2 (t) = V2ist determine. From the relative speed v1 (t) -v2 (t) and the knowledge of the own speed v2 (t), for example, in the upper elevator car K2, the current speed v1 (t) of the lower elevator car K1 can be determined.

According to the invention, the safety unit S1 of the lower elevator car K1 is able to independently determine the relative speed v2 (t) -v1 (t) by observing the passing lower cable SA. By means of the code reader L1 and the interaction (scanning) of the code strip C1, the safety unit S1 on the one hand the absolute position L1ist and in a preferred embodiment, the own speed v1 (t) = V1ist determine. From the relative velocity v2 (t) -v1 (t) and the knowledge of the own velocity v1 (t), e.g. in the lower elevator car K1 the current speed v2 (t) of the upper elevator car K2 can be determined.

According to the invention, the security units S1, S2 are self-sufficient in the sense that they are not dependent on information from the respective other security unit, which are received via a communication connection. This has the advantage that it requires no communication connections between the elevator cars K1, K2.

By counting or detecting the increments (the corresponding increment values can be stored in a memory as described), the respective other elevator car can make a statement about the instantaneous distance D. Thus, depending on the gear ratio, for example, 1000 increments of a distance of 1 meter correspond. If the value of 10000 is stored in the memory of the security unit S2, the current distance D is approximately 10 meters.

Since each of the elevator cars K1, K2 can determine its own absolute position L1 or L2ist independently by means of the code reader L1, L2, the respective position of the other elevator car K2, K1 can also be calculated by taking into account the stored increment value.

Analogously, each of the elevator cars K1, K2 can also make a statement about the speed v2 (t), v1 (t) of the respective other elevator car K2, K1. This is possible since the elevator car K1 is e.g. its own absolute velocity v1 (t) = V1 and the relative velocity v2 (t) -v1 (t) knows.

The second security unit S2 can be designed analogously to the first security unit S1. At start-up or after maintenance of an elevator installation 10 according to one of Figures 3, 4A, 4B, preferably a memory (e.g., a register) in the second security unit S2 is reset to zero. If now the support means TB of the other elevator car K1 moves past the incremental encoder I1, the safety unit S2 counts or determines the increments and stores these values or this value in the memory. By reading the memory, the security unit S2 has information about the relative distance D (t) at the time t. The information in the memory can always be overwritten with new information. If the information Ir is evaluated with respect to a time base t, a statement about the relative velocity v2 (t) -v1 (t) can be made.

On the basis of this information and taking into account specifiable rules (or algorithms), the security unit S2 can always relate the "movement behavior" of the upper elevator car K2 to the "movement behavior" of the lower elevator car K1. By means of rules (or algorithms) decisions can be made and reactions can be triggered. Thus, for example, the speed of the upper elevator car K2 by means of the settled there Speed limiter G2 can be reduced if V2ist> Vmax.

According to a further embodiment of the invention, one laser distance measuring device 30 is provided per elevator car K1, K2 in order to be able to measure the distance D to the respective other elevator car K2, K1 and / or the distance to a shaft end. These laser distance measuring devices 30 provide information that is partially redundant with the information Ir, Ic provided by the incremental encoders I1, I2 and / or the code readers L1, L2. In the Fig. 5 embodiment shown allows a statement about the absolute distance D between the two elevator cars K1, K2 and / or a statement about the absolute distance to the shaft bottom or the upper shaft end, depending on where the laser distance measuring device 30 is disposed on the respective elevator car. By using the laser distance measuring device 30, the safety of the elevator installation 10 is further increased.

There may be a laser distance measuring device 30 e.g. sit at the top of the lower elevator car K1, which sends a beam of light to the upper elevator car K2, which is reflected there and captured by the laser distance measuring device 30 and evaluated. Another laser distance measuring device 30 can sit at the lower area of the upper elevator car K2, which sends a light beam to the lower elevator car K1, which is reflected there and recaptured and evaluated by the laser distance measuring device 30.

The security units S1, S2 can be constructed digitally and the corresponding decision-making and evaluation structures can be realized by means of software. But it is also possible to provide appropriate logic circuits.

In a preferred embodiment, each of the safety units S1, S2 communicates with a central elevator control 40 via live cables, as in FIGS FIGS. 4A and 4B indicated by two dashed lines (communication links).

In a further preferred embodiment, each elevator car K1, K2 autonomously determine the distance to the respective other elevator car K2, K1 and trigger emergency braking when falling below a safety distance Dkrit. The triggering of emergency braking may additionally also take into account information about the speed of the elevator cars K1, K2. If the elevator cars K1, K2 move towards one another at high speed and the safety distance D crit is undershot, e.g. stronger braking maneuvers are performed.

It is an advantage of the invention that the two elevator cars K1, K2 are movable independently of one another. This is made possible in particular by a redundant and mutually independent architecture of the security units S1, S2 and the means I1, L2, or I2, L1 and 30.

In a further embodiment according to Fig. 6 a fourth elevator system 50 has two elevator cars K1, K2, each of which is assigned a counterweight 52.1, 52.2. In such an arrangement, for example, the upper elevator car K2 is suspended centrally at one end of a first suspension element T2 1: 1. The associated counterweight 52.2 is likewise suspended 1: 1 at the second end of the suspension element T2 and is positioned laterally between the upper elevator car K2 and a shaft wall, not shown. Between the upper elevator car K2 and the counterweight 52.2, the suspension element T2 is guided by a deflection roller 54 and a traction sheave 51.1, which are each perpendicular to the elevator car K2 and the counterweight 52.2.

The lower elevator car K1 is suspended on a second suspension element T1 2: 1. The associated counterweight 52.1 is likewise suspended 2: 1 on the same suspension element T1 and is positioned laterally between the lower elevator car K1 and a second shaft wall (not shown) relative to the counterweight 52.2 associated with the upper elevator car K2. The suspension element T1 of the lower elevator car K1 is guided by a first cable fixation point F1.T1 in the upper area of the hoistway laterally along a first cabin side of the upper elevator car K2 to the lower elevator car K1, there to two cabin deflection rollers 55, 56 by a total of 180 ° deflected and in turn guided laterally along a second of the first cabin side of the upper elevator car K2 cabin side up to another traction sheave 51.1. This traction sheave 51.1 deflects the support means T1 by 180 ° down to the associated counterweight 52.1. Finally, the support means T1 is guided by a further 180 ° by an upper counterweight deflection roller 53.1 in the upper region of the counterweight 52.1 to a second cable link point F2.T1, which is located in the upper region of the elevator shaft.

The upper elevator car K2 preferably has a lower cable S2, which is fastened with a first end in the lower region of the elevator shaft to a cable fix point F1.S2. This cable fix point F1.S2 lies laterally offset below the projection of the counterweight 52.1 of the lower elevator car K1. The sub-cable S2 is then guided starting from the first cable fix point F1.S2 laterally along a first cabin side of the lower elevator car K1 to two cabin deflection rollers 57, 58, which are mounted in the lower region of the upper elevator car K1. At the two cabin deflection rollers 57, 58, the lower cable S2 is deflected by a total of 180 ° and in turn guided laterally along a second cabin side of the lower elevator car K1 down to a guide roller 59 in the lower region of the elevator shaft. This guide roller 59 steers the lower rope S2 by 180 ° up to a counterweight pulley 53.2 um, which is located in the lower region of the associated counterweight 52.2. At this counterweight pulley 53.2, the lower rope S2 is again deflected by 180 ° down and guided into the lower region of the elevator shaft. Finally, the lower cable S2 is fastened at its second end to a further cable link point F2.S2.

The lower elevator car K1 and the associated counterweight 52.1 are tensioned by means of a further lower cable S1. The sub-cable S1 is attached at a first end to the underside of the lower elevator car K1 and at a second end to the underside of the associated counterweight 52.1. In addition, two further deflection rollers 60, 61 are positioned in the lower region of the elevator shaft for guiding the lower cable S1 between the lower elevator car K1 and the counterweight 52.1.

All in the Fig. 3 to 5 shown embodiments and descriptions are basically applicable to the fourth elevator system 50. With regard to the information Ir of the incremental encoders I1, I2, however, attention must be paid to the following for suspension ratios of the passing suspension element T1 or sub-section S2, which deviate from 1: 1.

• absolute Position Llist
• absolute Geschwindigkeit vlist
• relativer Abstand D(t)*
• Relativgeschwindigkeit v1(t)*-v2(t)*
• Aufhängungsverhältnis des Unterseils S2 an der oberen Aufzugskabine K2

To according to the embodiment Fig. 6 to close the movement state of each adjacent elevator car K1, K2, for example, has a security unit S1 on the following information:

• absolute position Llist
• absolute speed vlist
• relative distance D (t) *
• Relative velocity v1 (t) * - v2 (t) *
• Suspension ratio of the sub-cable S2 to the upper elevator car K2

On the basis of this and, if appropriate, further information and taking into account specifiable rules (or algorithms), the safety unit S1 of the lower elevator car K1 is able to autonomously detect the relative speed v1 (t) -v2 (t) by observing the passing sub-cable S2 to investigate. The measured relative distance D (t) * is to be understood as the length of the passing sub-line S2 per time unit and the relative speed v1 (t) * - v2 (t) * derived therefrom. Since the sub-cable S2 is suspended with the adjacent elevator car K2 in the ratio 2: 1, the measured relative distance D (t) * only exceptionally corresponds to the real relative distance D (t) between the elevator cars K1, K2 due to the information Ir. The safety unit S1 therefore calculates the real relative distance D (t) or the real relative speed v1 (t) -v2 (t) based on the above information, in particular also the suspension ratio deviating from 1: 1.

The above considerations are also applicable to the upper elevator car K2, in particular to the observation of the passing suspension means T1 and to the calculation of the real relative distance D (t) or the real relative velocity v1 (t) -v2 (t).

According to the invention, the safety unit S2 of the upper elevator car K2 is capable of autonomously determining the relative speed v1 (t) -v2 (t) by observing the carrying means T1 passing by. By means of the code reader L2 and the interaction (scanning process) of the code strip C2, the security unit S2 can on the one hand determine the absolute position L2 and, in a preferred embodiment, also determine its own speed v2 (t) = V2ist. From the calculated relative speed v1 (t) -v2 (t) and the knowledge of the own speed v2 (t), for example, in the upper elevator car K2, the current speed v1 (t) of the lower elevator car K1 can be determined.

According to the invention, the safety unit S1 of the lower elevator car K1 is able to autonomously determine the relative speed v2 (t) -v1 (t) by observing the passing lower cable S2. By means of the code reader L1 and the interaction (scanning) of the code strip C1, the safety unit S1 on the one hand the absolute position L1ist and in a preferred embodiment, the own speed v1 (t) = V1ist determine. From the calculated relative velocity v2 (t) -v1 (t) and the knowledge of the own velocity v1 (t), e.g. in the lower elevator car K1 the current speed v2 (t) of the upper elevator car K2 can be determined.

Claims (11)

1. Lift system (10) with

   - a lower lift cage (K1),

   - an upper lift cage (K2),

   - at least one counterweight (12),

   - support means (TA, TB) for supporting the lower and upper lift cages (K1, K2), wherein at least one support means (TB) for supporting the lower lift cage (K1) is led downwardly in the lift shaft (11) laterally along the upper lift cage (K2),

   - drive means for driving the lower and upper lift cages (K1, K2), and

   - a common lift shaft (11) in which the upper lift cage (K2) and the lower lift cage (K1) vertically move independently of one another,

   characterised in that

   - arranged at the upper lift cage (K2) is a first incremental transmitter (I1) which interacts with a support means (TB) for supporting the lift cage (K1) and supplies to the upper lift cage (K2) information about a change in the spacing (D) between the lower and upper lift cages (K1, K2).
2. Lift system (10) according to claim 1, characterised in that the upper lift cage (K2) has at least one lower cable (SA, SB) which is led downwardly in the lift shaft (11) laterally along the lower lift cage (K1), wherein arranged at the lower lift cage (K1) is a second incremental transmitter (12) which interacts with the at least one lower cable (SA) of the upper lift cage (K2) and supplies to the lower lift cage (K1) information about a change in the spacing (D) between the lower and upper lift cages (K1, K2).
3. Lift system (10) according to claim 1 or 2, characterised in that the lift system (10) comprises means for controlling the spacing (D) between the lower and upper lift cages (K1, K2), wherein these means comprise a vertically extending code strip (C1, C2) fastened in the lift shaft (11) as well as a first code reader (L1) at the lower lift cage (K1) and a second code reader (L2) at the upper lift cage (K2).
4. Lift system (10) according to claim 3, characterised in that the lower lift cage (K1) comprises a first safety unit (S1) and the upper lift cage (K2) a second safety unit (S2), wherein the first safety unit (S1) obtains information (Ic) from the first code reader (L1) and information (Ir) from the second incremental transmitter (12) of the lower lift cage (K1) and the second safety unit (S2) obtains information (Ic) from the second code reader (L2) and information (Ir) from the first incremental transmitter (I1) of the upper lift cage (K2).
5. Lift system (10) according to claim 1 to 4, characterised in that the lower lift cage (K1) is suspended at two separate mutually opposite fastening regions (15.1, 15.11) to be laterally balanced.
6. Lift system (10) according to claim 1 to 5, characterised in that the upper lift cage (K2) is suspended in a central upper fastening region (15.2, 15.22) at an end of the support means run (TA).
7. Lift system (10) according to any one of claims 1 to 6, characterised in that the incremental transmitters (I1, I2) each comprise at least one roller (20.1, 20.2), preferably a friction wheel, which can be set into rotation by the respective support means (TB), which run past, for supporting the lower lift cage (K1) or by the lower cable (SA) of the upper lift cage (K2).
8. Lift system (10) according to claim 7, characterised in that a decoder (21), preferably an angle decoder, is provided at the roller (20.1, 20.2), the decoder detecting rotations (R) of the roller (20.1, 20.2) and transmitting corresponding information (Ir) to a safety unit (S1, S2) of the respective lift cage (K1, K2).
9. Lift system (10) according to any one of claims 1 to 8, characterised in that a code strip (C1, C2) is provided for each lift cage (K1, K2) and wherein the code reader (L1, L2) contactlessly, preferably optically or magnetically, scans the respective code strip (C1, C2), wherein the first code reader (L1) supplies the first safety unit (S1) with information (Ic) about the instantaneous absolute position (L1ist) and the instantaneous speed (V1list) of the lower lift cage (K1) and wherein the second code reader (L2) supplies the second safety unit (S2) with information (Ic) about the instantaneous absolute position (L2ist) and the instantaneous speed (V2ist) of the upper lift cage.
10. Lift system (10) according to claim 9, characterised in that

    - a first speed limiter (G1) controllable by the first safety unit (S1) is provided at the lower lift cage (K1), wherein the first safety unit (S1) triggers the first speed limiter (G1) if the instantaneous speed (V1ist) of the lower lift cage (K1) falls below a maximum permissible limit value (Vmax) and

    - a second speed limiter (G2) controllable by the second safety unit (S2) is provided at the upper lift cage (K2), wherein the second safety unit (S2) triggers the first speed limiter (G1) if the instantaneous speed (V2ist) of the upper lift cage (K2) falls below a maximum permissible limit value (Vmax).
11. Lift system (10) according to any one of the preceding claims 1 to 10, characterised in that a laser distance measuring device (30) is provided for each lift cage (K1, K2) and measures the spacing (D) from the respective other lift cage (K1, K2) and/or the spacing from a shaft end.

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