EP3052424B1 - Elevator installation - Google Patents

Description

The invention relates to an elevator installation with a shaft, in which at least two cars are arranged one above the other and can be moved separately from one another in the vertical direction upwards and downwards, with each car being assigned a travel drive for moving the car.

In order to transport a large number of people by means of an elevator system within a short period of time, it is from the international publication WO 2004/048243 A1 It is known to arrange at least two cars in a shaft and to move them vertically upwards and downwards along a common carriageway. A travel drive is assigned to each car, with the aid of which the car can be moved.

To achieve a high transport capacity, it is advantageous if a passenger outside the shaft of a control device of the elevator system can enter a destination call with which he indicates his destination. The control device can then carry out an assignment evaluation for all cars and can assign the destination call to the car with the best assignment rating.

The cars usually have a considerable safety distance from one another, which ensures that when two cars are driven in series, the rear car in the direction of travel can also be braked reliably without the risk of collision if the car in the direction of travel brakes suddenly in the event of a fault.

Elevator systems are also known in which two cars arranged one above the other are permanently connected to one another and simultaneously move to two floors that are directly adjacent to one another. The two cars are driven by a common travel drive and form a so-called double-decker elevator.

In order to be able to adapt the distance between the two cars of a double-decker elevator to different floor-to-floor distances, complex double-decker elevators are known in which the two cars are kept movable in a common frame and can be displaced relative to one another in the vertical direction with the aid of an additional drive unit, so that the vertical distance between the cars can be adapted to the distances between neighboring floors. Double-decker elevators are particularly suitable for commuting between two immediately adjacent start floors and two fixed, directly adjacent destination floors. Double-decker elevators are only of limited suitability for journeys between individually selectable start and finish floors, since the compulsory stopping of both cars on floors immediately adjacent to one another limits the transport capacity. document US 1 805 227 discloses an elevator system with two mutually coupled cars according to the preamble of claim 1.

The object of the present invention is to develop an elevator installation of the type mentioned at the outset in such a way that the cars can be moved in large and small distances from one another in a structurally simple manner without risk of collision.

This object is achieved according to the invention in an elevator installation of the type mentioned at the outset in that at least two cars can be coupled to one another via a variable-length detachable coupling device, the distance between the coupled cars using at least one of the travel drives of the two cars as a function of the relative speed is changeable between the two cars.

The elevator installation according to the invention has a first operating mode and a second operating mode. In the first operating mode, at least two cars, which can be moved in a common shaft, can be moved separately from one another in the shaft, in this operating mode they can move to individually selectable start and destination floors and have a rather large distance from one another. In the second operating mode of the elevator system, the at least two cars are coupled to one another via a variable-length detachable coupling device. The coupling device ensures that when the cars are driven one behind the other, the rear car in the direction of travel has practically the same braking deceleration as the front car in the direction of travel. In the second operating mode, the two cars can therefore be moved at a very short distance from one another without the risk of collision.

In order to be able to adapt the vertical distance of the cars coupled to one another to different floor distances in a structurally simple manner, a length-adjustable coupling device is used in the elevator installation according to the invention, with the aid of which the distance between the cars coupled to one another can be changed. The change in length does not require an additional drive unit, but the change in length can be achieved with the aid of at least one of the travel drives of the coupled cars.

In order to avoid the risk of a collision, the vertical distance between the cars can only be changed if the relative speed of the cars coupled to one another fulfills at least one predefined criterion. The change in distance is therefore dependent on the relative speed of the two cars. This ensures that at low relative speeds, such as those which occur when the vertical distance is adapted to different floor distances, a change in distance can be carried out with the aid of at least one of the travel drives of the coupled cars, but in the case of a high relative speed between the coupled cars Cars, such as those that could be present in the event of a fault, in which the front car suddenly brakes in the direction of travel, a change in distance is blocked. Thus, despite the provision of a variable-length coupling device, a collision of the mutually coupled cars can be reliably prevented even in the event of a fault.

For example, it can be provided that the distance between the mutually coupled cars can be changed at relative speeds up to a predetermined or predeterminable maximum permissible relative speed. A maximum permissible relative speed between the cars coupled to one another can thus be predetermined or predeterminable. At relative speeds up to the maximum permissible relative speed, the vertical distance between the cars can be changed with the help of at least one of the travel drives of the coupled cars. At relative speeds above the maximum permissible relative speed, the coupling device can be blocked so that its length cannot be changed and consequently a change in distance is not possible.

As already mentioned, the distance between two coupled cars can be changed with the help of at least one of the drives of the cars. It is advantageous if the distance between the cars that are coupled to one another can be changed using the travel drives of all the coupled cars as a function of the relative speed between the cars.

To increase the distance, it can be provided, for example, that the front of the car in the direction of travel is moved away from the car in the direction of travel in the coupled state with the aid of its travel drive. To reduce the distance, it can be provided that the car, which is at the rear in the direction of travel, is moved in the coupled state with the aid of its travel drive in the direction of the car at the front in the direction of travel.

In an advantageous embodiment, the coupling device comprises at least one motor coupling drive for establishing and releasing the coupling between the cars. The motor coupling drive can be, for example, an electric motor with a comparatively low electrical output or, for example, also a hydraulic or pneumatic drive.

The elevator system advantageously comprises sensors which provide a signal corresponding to the relative speed of the cars. For example, decoders or speed sensors can be used as sensors or, for example, ultrasound sensors or position sensors, with the help of which the position of the cars in the shaft can be determined. The speed of the cars and also the relative speed of the cars can be determined from the changing position data.

At least one sensor for determining the relative speed between the cars is advantageously arranged on at least one car.

The cars are advantageously driven via suspension means, via which the cars are connected to the drives. In particular, suspension cables can be used as suspension elements.

It is advantageous if the cars are each connected to a counterweight via the suspension means.

In a particularly preferred embodiment of the invention, the coupling device has at least one movable coupling element, to which an influencing element is assigned for influencing the movement of the coupling element as a function of the relative speed between the mutually coupled cars. To change the vertical distance between In the case of such an embodiment of the invention, two at least one coupling member can be moved relative to at least one of the cars in such an embodiment of the invention. The movement of the coupling element takes place as a function of the relative speed between the two cars. This ensures that in the event of a malfunction in which there is a high relative speed, for example due to an emergency stop of the front car in the direction of travel, a collision of the cars can be reliably prevented. For this purpose, the movement of the coupling member can be influenced, in particular braked or blocked, by the influencing member.

In particular, it can be provided that the speed which the coupling member has relative to at least one of the two cars can be limited by means of the influencing member. At higher relative speeds, a different speed can thus be provided for the coupling member than at lower relative speeds, which the cars are coupled to one another.

It is expedient if the coupling member can be locked by means of the influencing member. This makes it possible to prevent movement of the coupling member and thus also a change in the vertical spacing of the cars coupled to one another at relatively high relative speeds.

The at least one coupling member can advantageously transmit tensile and compressive forces between the mutually coupled cars.

It is particularly advantageous if the coupling device has a plurality of coupling elements of identical design.

The coupling members are advantageously arranged symmetrically to a central axis of the cars.

For example, it can be provided that the cars have at least one coupling member on diametrically opposite sides.

In an advantageous embodiment of the elevator system according to the invention, the at least one coupling element has a hydraulic or pneumatic piston-cylinder unit with a double-acting cylinder and the influencing element is designed as a compensating device, the annular space surrounding the piston rod of the piston-cylinder unit via the compensating device depending on the Relative speed between the two coupled cars can be connected to the piston chamber of the piston-cylinder unit arranged on the end face of a piston. In such an embodiment, the coupling glio-d has a hydraulic or pneumatic cylinder in which a piston is arranged. Starting from the piston, a piston rod extends out of the cylinder. The piston divides the interior of the cylinder into an annular space and a piston space. The annular space surrounds the piston rod and the piston space is arranged on the end face of the piston. A flow connection between the annular space and the piston space can be achieved via a compensation device, the flow connection taking place as a function of the relative speed between the two cars, which are connected to one another via the piston-cylinder unit. The hydraulic or pneumatic cylinder can be positioned on a first of the two cars and the piston rod can extend from the first car to the second car.

If the connection between the annular space and the piston space is released by the compensation device, a medium, for example compressed air or hydraulic oil, can flow from the annular space into the piston space or in the opposite direction from the piston space into the annular space in order to change the vertical distance between the two cars. If the connection is not released by the compensation device, the flow connection is between the annular space and the piston space interrupted and media exchange is not possible, so that the piston in the cylinder can not change position. This in turn means that the vertical distance between the cars coupled together via the piston-cylinder unit cannot be changed.

In an advantageous embodiment, the compensation device has at least one throttle or blocking element that can be controlled as a function of the relative speed between the two cars.

In particular, it can be provided that the compensation device has at least one electrically controllable throttle element.

With the help of the at least one controllable throttle element, the flow cross section of a connecting line between the annular space and the piston space can be changed as a function of the relative speed between the two cars. For example, it can be provided that the throttle element provides a relatively large flow cross section at lower relative speeds, in particular at relative speeds up to a predeterminable or predefined maximum permissible relative speed, whereas the flow cross section at large relative speeds, in particular when a predeterminable or predefined maximum permissible relative speed is exceeded is greatly reduced, in particular reduced to a value of 0, so that the flow connection between the annular space and the piston space is interrupted by means of the throttle element.

Alternatively or additionally, it can be provided that the compensating device has at least one hydraulically or pneumatically controllable blocking element, for example a pressure-dependent closing valve. The controllable blocking element, in particular the pressure-dependent closing valve, can be connected into the connecting line between the annular space and the piston space and the connecting line depending on the relative speed lock and unlock between the two cars. When using the pressure-dependent closing valve, the connecting line can be blocked if the pressure in the connecting line upstream of the closing valve exceeds a predetermined maximum permissible pressure value due to an excessive relative speed between the two cars.

It is favorable if the compensation arrangement has at least one pump. The pump forms a motor-driven coupling drive, with the aid of which, for example, a hydraulic medium can be pressurized in order to move the piston rod to create and release the coupling between two cars. The performance of the pump can be relatively low, since it is only used to create and release the coupling, but not to change the distance between the cars.

For example, it can be provided that a first car is arranged below a second car, at least one piston-cylinder unit being arranged on the first car. The annulus of the double-acting cylinder of the piston-cylinder unit is connected to the piston chamber via a compensating device and the compensating device has a pump, with the aid of which hydraulic fluid under pressure can be applied to the piston chamber. This makes it possible to move the piston rod in the direction of the second car arranged above the first car. At the free end of the piston rod, first connecting elements can be arranged, which interact with second connecting elements arranged on the second car to produce a coupling of the two cars. By means of a locking device arranged on the second car, the connecting elements can be locked after coupling. If the coupling between the two cars is to be released, the preferably motorized locking device can move the interconnecting connecting elements into a release position and then the second car arranged above the first car can be moved with the help of its Travel drive are moved in the direction facing away from the first car upwards.

In an advantageous embodiment of the invention, the at least one coupling element has a first mechanical coupling element and a second mechanical coupling element which can be brought into engagement with one another and can be moved relative to one another, and the influencing element has at least one controllable braking element, the relative movement of the two coupling elements in Can be braked and / or locked depending on the relative speed of the mutually coupled cars using the braking element.

It can be provided, for example, that the first mechanical coupling element is designed as a threaded spindle which is rotatably mounted about its longitudinal axis on a first of the mutually connectable cars, and that the second coupling element is designed as a threaded nut which is held on a second of the mutually couplable cars, which has the threaded spindle can be brought into engagement, wherein the threaded spindle can be locked by means of a controllable braking element as a function of the relative speed between the two cars and / or its speed can be limited. In such an embodiment of the invention, the two cars are coupled via at least one threaded spindle and a threaded nut which engages with it. The threaded spindle can be rotated about its longitudinal axis, the rotatability being able to be influenced with the aid of a controllable braking element. If the two cars are moved relative to each other, the threaded spindle rotates and the threaded nut moves along the threaded spindle, so that the vertical distance between the two cars changes. However, such a change only takes place at relatively low relative speeds, in particular at relative speeds below a predetermined or predeterminable maximum permissible relative speed. If the actual relative speed is greater than the maximum permissible relative speed, the braking element brakes the threaded spindle so that it is completely locked or can only assume a relatively low speed.

It is expedient if the threaded spindle can be driven to rotate with the aid of a motor coupling drive, in particular with the aid of an electric motor. This enables the coupling between the two cars to be made or released via the threaded rod and the threaded nut either by activating the motorized coupling drive. In addition, any self-locking of the threaded spindle can be overcome by the motor coupling drive.

It can also be provided that the first mechanical coupling element is designed as a toothed rack held on a first of the mutually connectable cars and that the second mechanical coupling element is designed as a gear wheel rotatably mounted on a second of the mutually connectable cars that can be brought into engagement with the toothed rack and its speed can be limited and / or locked by means of a controllable braking element as a function of the relative speed of the two cars. In such an embodiment of the invention, the coupling between a first and a second car takes place with the aid of at least one toothed rack and a toothed wheel which meshes with the toothed rack and which, depending on the relative speed between the two cars, is braked and / or locked with the aid of a braking element can be. A change in the vertical distance between the first and the second car can be achieved at low relative speeds with the help of the travel drives of the cars, the rack and the toothed wheel changing their relative position. However, if there is a relatively high relative speed, in particular a relative speed that is greater than the maximum permissible relative speed, the rotational movement of the gear is braked and / or the gear is locked, so that at most a slow change in distance or no change in distance between the cars is possible.

It can also be provided that the at least one coupling element has a plurality of mechanical coupling elements which are arranged on a first of the mutually couplable cars and movably connected to one another and can be detachably coupled to a second of the mutually couplable cars, the coupling elements being between a compact supply position and different Extended coupling positions can be moved back and forth and can be braked and / or locked by means of the influencing element depending on the relative speed of the two cars. In such an embodiment, the coupling of the two cars is carried out with the aid of the coupling elements which can be extended from a compact storage position into coupling positions of different dimensions. The movement of the coupling elements is braked and / or locked depending on the relative speed between the two cars by the influencing member.

The coupling elements can interlock, for example, telescopically. In such a configuration, directly adjacent coupling elements are immersed in one another in a compact supply position, and in differently extended coupling positions the coupling elements are moved more or less far apart. The movement of the coupling elements relative to one another can be braked and / or locked by the influencing element. The locked coupling elements can be used to transmit tensile and compressive forces between the two cars. To extend and retract the coupling elements, the cages can be moved relative to one another at a low relative speed by means of their travel drives.

It is particularly advantageous if the mechanical coupling elements form a support chain and the influencing element is designed as a brakable and / or lockable gearwheel which is in engagement with the support chain. The support chain has a large number of coupling elements in the form of support chain links. In a compact storage position, at least two sections of the support chain are preferably arranged side by side or one above the other, wherein the support chain links of the individual sections are preferably aligned horizontally. In an extended coupling position, at least some of the support chain links are lined up on one another and form a vertical support chain section, via which two cars can be coupled to one another. The influencing member is designed as a toothed wheel which is in engagement with the support chain and which can be braked and / or locked. If the gearwheel is locked, the support chain can no longer be moved, and pressure and tensile forces can be transmitted from one of the two cars to the other car via the support chain.

Figur 1:

eine schematische Darstellung einer ersten vorteilhaften Ausführungsform einer erfindungsgemäßen Aufzuganlage;

Figur 2:

eine schematische Darstellung einer zweiten vorteilhaften Ausführungsform einer erfindungsgemäßen Aufzuganlage;

Figur 3:

eine schematische Darstellung einer dritten vorteilhaften Ausführungsform einer erfindungsgemäßen Aufzuganlage, und

Figur 4:

eine schematische Darstellung einer vierten vorteilhaften Ausführungsform einer erfindungsgemäßen Aufzuganlage.

The following description of advantageous embodiments of the invention serves in conjunction with the drawing for a more detailed explanation. Show it:

Figure 1:

a schematic representation of a first advantageous embodiment of an elevator system according to the invention;

Figure 2:

a schematic representation of a second advantageous embodiment of an elevator system according to the invention;

Figure 3:

a schematic representation of a third advantageous embodiment of an elevator system according to the invention, and

Figure 4:

is a schematic representation of a fourth advantageous embodiment of an elevator system according to the invention.

In Figure 1 A first advantageous embodiment of an elevator installation according to the invention is shown schematically and overall designated by reference number 10. The elevator installation 10 comprises an upper elevator car 12 and a lower elevator car 14, which are arranged one above the other in a shaft 16 and can be moved up and down along common guide rails, which are known per se and are therefore not shown in the drawing for a better overview. The upper car 12 is over several first suspension cables, of which only a first suspension cable 18 is shown in the drawing for a better overview, coupled to a first counterweight 20. In a corresponding manner, the lower car 14 is coupled to a second counterweight 24 via a plurality of second support cables, of which only a second support cable 22 is shown in the drawing for a better overview.

A first travel drive 26 is assigned to the upper car 12. The first travel drive 26 has a first traction sheave 28 which can be set in rotation by a drive motor in the usual manner and therefore not shown in the drawing. The first suspension cables 18 are guided over the first traction sheave 28.

The lower car 14 is assigned a second travel drive 30 with a second traction sheave 32 which can be set in rotation by a second drive motor which is known per se and is therefore not shown in the drawing in order to achieve a better overview. The second suspension cables 22 are guided over the second traction sheave 32.

The invention is explained below using the example of the elevator system 10, in which the cars 12 and 14 are suspended from support cables 18, 22. However, the invention is not limited to such cable lifts, but also extends to elevator systems, the cars of which are moved with the aid of other travel drives, for example with the aid of linear drives.

In a first operating mode of the elevator installation, the two cars 12 and 14 can be moved up and down separately in the shaft 16. In this operating mode, the cages 12 and 14 are at a safety distance which ensures that when the two cages 12, 14 are driven one behind the other, the car in the rear in the direction of travel can also be braked reliably without the risk of collision if the car in the direction of travel suddenly abruptly in the event of a fault slows down.

In a second operating mode of the elevator system 10, the two cars 12, 14 are coupled to one another via a variable-length detachable coupling device 34. In the coupled state, the vertical distance between the two cars 12, 14 can be changed, provided that the two cars 12, 14 have a relatively low relative speed to each other. If the relative speed exceeds a predetermined maximum permissible relative speed, it is no longer possible to change the distance. This ensures that the two cars 12, 14 cannot collide with one another in the coupled state, even if they are at a very short distance from one another.

The coupling device 34 comprises a first coupling member in the form of a first piston-cylinder unit 36 and a second coupling member in the form of a second piston-cylinder unit 38, which are arranged on the outer sides of the lower car 14 facing away from one another. The first piston-cylinder unit has a first hydraulic cylinder 40 which is fixed to the lower car 14 and in which a first piston 42 is slidably mounted, from which a first piston rod 44 extends vertically upwards. The first piston rod 44 protrudes from the first hydraulic cylinder 40 in the direction of the upper car 12 and can be connected to the upper car 12 by means of a first detachable connecting device 46.

The interior of the first hydraulic cylinder 40 is divided by the first piston 42 into a first annular space 48 and a first piston space 50. The first annular space 48 surrounds the first piston rod 44 and the first piston space 50 is arranged on the end face of the first piston 42 facing away from the first piston rod 44.

The second piston-cylinder unit 38 comprises a second hydraulic cylinder 52, which is fixed to the lower car 14 and receives a second piston 54, from which a second piston rod 56 extends in the direction of the upper car 12, the free end of which helps one second connecting device 58 can be connected to the upper car 12. The interior of the second hydraulic cylinder 52 is divided by the second piston 54 into a second annular space 60 and a second piston space 62. The second annular space 60 surrounds the second piston rod 56 and the second piston space 62 is arranged on the end face of the second piston 54 facing away from the second piston rod 56.

The first connecting device 46 and the second connecting device 58 each have a motor-driven locking member 64 or 66, with the aid of which the connections between the piston rods 44, 56 and the upper car 12 can be locked or released. The locking members 64, 66 can be designed, for example, as a motor-driven latch. The latches can be driven, for example, with the aid of electric motors or also with the aid of pneumatic or hydraulic drives or also electromagnetically.

The annular spaces 48 and 60 of the two piston-cylinder units 36, 38 are connected to one another via a compensation device 68. The compensation device 68 comprises a connecting line 70 which extends from the second annular space 60 to the second piston space 62 and to which a first connecting line 72 starting from the first annular space 48 and a second connecting line 74 starting from the first piston space 50 are connected. A first electrically controllable throttle element 76 and a second electrically controllable throttle element 78 are connected in series to one another in the first connecting line 70. A supply line 80 branches off from the first connecting line 70 between the two throttle elements 76, 78. A filter 82 is connected to the supply line 80. The supply line extends into the interior of a surge tank 84 of the surge device 68. The surge tank 84 forms a reservoir for hydraulic fluid.

In the area between the first throttle element 76 and the second annular space 60, a first pressure-dependent closing valve 88 is connected into the connecting line 70.

In the area between the second throttle element 78 and the second piston chamber 62, a second pressure-dependent closing valve 94 is connected into the connecting line 70. In parallel to the second closing valve 94 and the second throttle element, a check valve 96 and a motor coupling drive in the form of a hydraulic pump 98 are connected in series to one another in a pump line 99. The check valve 96 opens in the direction of the second piston chamber 62. The pump line 99 branches off from the connecting line 70 in the region between the second throttle element 78 and the second piston chamber 62 and opens into the expansion tank 84.

The first annular space 48 and the second annular space 60 are thus connected to the first piston space 50 and the second piston space 62 via the connecting lines 72, 74 and the connecting line 70. This enables the upper car 12 to be moved relative to the lower car 14 in the coupled state. For example, the lower car 14 can be moved in the coupled state in the direction of the upper car 12 with the aid of the second traction sheave 32. The volume of the two piston spaces 50 and 62 is reduced and hydraulic fluid can flow from the piston spaces 50, 62 into the annular spaces 48 and 60 via the connecting lines 72, 74 and the connecting line 70. The hydraulic fluid flows through the throttle elements 76 and 78 and the pressure-dependent closing valves 88, 94. However, such a compensation of hydraulic fluid between the piston spaces 50, 62 and the annular spaces 48, 60 is only possible if the throttle elements 76, 78 have a flow cross section of the connecting line 70 release and the closing valves 88, 94 do not interrupt the flow connection. This is the case if the two cars 12, 14 have a relatively low relative speed to one another. In the exemplary embodiment shown, a sensor 100 is arranged on the floor of the upper car 12 to determine the relative speed. Alternatively or in addition, a sensor 102 could also be arranged on the ceiling of the lower car 14. The sensor 100 detects the distance between the two cars 12, 14 and is connected to a control device of the elevator system 10 via a sensor line which is known per se and is therefore not shown in the drawing in order to achieve a better overview a better overview in the drawing signal lines, not shown, is connected to the electrically controllable throttle elements 76, 78. The control device determines the relative speed that the two cars 12, 14 have from one another from the changes in the relative distances over time. If the relative speed exceeds a predefined or predeterminable maximum permissible relative speed, the flow connection between the piston spaces 50, 62 and the annular spaces 48, 60 is interrupted by means of the throttle elements 76, 78, whereas in the case of relative speeds that are lower than the maximum permissible relative speed, the aforementioned Flow connection from the throttle elements 76, 78 is released. Regardless of the electrical control of the throttle elements 76, 78, the closing valves 88, 94 block the connecting line 70 when the pressure in the annular spaces 48, 60 or in the piston spaces 50, 62 due to an abrupt change in the distance between the cars 12, 14 and a related one abrupt movement of the pistons 42 and 54 increased inadmissible. At low relative speeds, a compensation of hydraulic fluid between the piston spaces 50, 62 and the annular spaces 48, 60 can thus take place, whereas at high relative speeds, such compensation of hydraulic fluids is not possible. At relative speeds above the maximum permissible relative speed, the two cars 12, 14 are thus rigidly coupled to one another, provided the piston rods 44 and 56 are connected to the upper car 12, and at low relative speeds in the coupled state of the two cars 12, 14, a change in the vertical distance between the two cars 12, 14 are made. This gives the possibility of moving the two cars in the coupled state at a short distance from one another in the shaft 16, the vertical distance between the two Cars 12, 14 can be adapted to different floor distances.

To produce the mechanical coupling between the lower car 14 and the upper car 12, the two cars can first be positioned at a short distance from one another by means of their travel drives 26, 28, and then the piston rods 44 and 56 can be positioned by means of the pump 98. The first piston rod 44 can then be connected to the upper car 12 by means of the first connecting device 46 and the second piston rod 56 can be connected to the upper car 12 by means of the second connecting device 58. The connection can then be locked by means of the locking members 64, 66.

The elevator system 10 thus makes it possible to move the two cars 12, 14 either separately from one another or in a coupled state in the shaft 16. In the coupled state, the vertical distance which the two cars 12, 14 assume from one another can be changed by means of the travel drives 26 and 30, provided the cars 12, 14 have a relatively low relative speed to one another, otherwise a change in distance is not possible.

In Figure 2 A second advantageous embodiment of an elevator installation according to the invention is shown schematically and overall designated with reference number 110. Corresponding to the elevator system 10 explained above, the elevator system 110 has an upper car 112 and a lower car 114, which can be moved up and down in a shaft 116. The upper car 112 is connected to a first counterweight 120 via first support cables, of which only a first support cable 118 is shown in the drawing, and the lower car 114 is connected via second support cables, of which only a second support cable 122 is shown in the drawing is connected to a second counterweight 124. A first travel drive 126 with a first traction sheave 128 is assigned to the upper car 112. The first suspension cables 118 are guided over the first traction sheave 128. The Lower car 114 is assigned a second travel drive 130 with a second traction sheave 132. The second suspension cables 122 are guided over the second traction sheave 132.

The elevator installation 110 has a coupling device 134, via which the two cars 112, 114 can be coupled to one another. The coupling device 134 comprises a first coupling member, which has a first mechanical coupling element in the form of a first threaded spindle 136 and a second mechanical coupling element in the form of a first threaded nut 138, which is in engagement with the first threaded spindle 136 when the two cages 112, 114 are coupled . In addition, the coupling device 134 has a second coupling element with a first mechanical coupling element in the form of a second threaded spindle 140 and with a second mechanical coupling element in the form of a second threaded nut 142, which engages with the second threaded spindle 140 when the two cages 112, 114 are coupled stands. The two threaded spindles 136, 140 are rotatably mounted on the outer sides of the upper car 112 facing away from one another and can be braked and locked by means of a first brake element 144 or with the aid of a second brake element 146.

The first threaded nut 138 and the second threaded nut 142 are secured to the lower car 114. In order to be able to screw the first threaded spindle 136 into the first threaded nut 138 to produce a coupling of the two cages 112, 114, a first motor coupling drive in the form of a first motor 148 is arranged on the upper car 112. In order to be able to screw the second threaded spindle 140 into the second threaded nut 142 to produce a coupling of the two cars 112, 114, a second motor coupling drive in the form of a second motor 150 is arranged on the upper car 112. The two threaded spindles 136, 140 can each be set in rotation about their longitudinal axis by means of the two motors 148, 150. After screwing the threaded spindles 136, 140 into the threaded nuts 138, 142, the two motors 148, 150 a self-locking of the threaded spindles 136, 140 is overcome, so that the threaded spindles 136, 140 can then rotate about their longitudinal axis when the two cars 112, 114 move relative to one another and the threaded nuts 138, 142 can thereby move along the threaded spindles 136, 140, the vertical distance between the upper car 112 and the lower car 114 changes. A change in distance can thus be achieved in a simple manner after the coupling has been carried out with the aid of the travel drives 126, 130.

The vertical distance between the cars 112, 114 is only changed at relatively low relative speeds. For this purpose, the elevator system 110 also includes a sensor 152 arranged on the floor of the upper car 112. Alternatively or in addition, a sensor arranged on the ceiling of the lower car 114 can be used. The sensor 152 is similar to that above with reference to FIG Figure 1 Sensor 100 explained is connected to a control device, not shown in the drawing, which controls the electrically controllable brake elements 144, 146 as a function of the relative speed between the two cars 112, 114. If the relative speed exceeds a predetermined maximum permissible relative speed, then the two brake elements 144, 146 block movement of the threaded spindles 136, 140, so that no change in distance can be carried out and the two cars 112, 114 are rigidly connected to one another. A change in distance can only take place if the actual relative speed determined by means of sensors 152, 154 falls below the maximum permissible relative speed. As an alternative or in addition to the at least one distance sensor 152, at least one speed sensor can also be used, which detects the speed of the threaded spindle 136 or 140. At an impermissibly high speed, which corresponds to an impermissibly high relative speed of the cars 112, 114, the movement of the threaded spindles 136, 140 is blocked, so that no change in distance can be carried out.

In Figure 3 schematically shows a third advantageous embodiment of an elevator installation according to the invention, which is denoted overall by reference number 160. The elevator installation 160 is largely identical to the one above with reference to that in FIG Figure 2 Elevator system 110 shown. For identical components, therefore, in Figure 3 uses the same reference numerals as in Figure 2 and with regard to these components, reference is made to the explanations above in order to avoid repetition.

In the Figure 3 The elevator system 160 shown differs from the elevator system 110 explained above in that the coupling of the upper car 112 to the lower car 114 takes place with the aid of a first toothed rack 162 arranged on the upper car 112 and a second toothed rack 164 also arranged on the upper car 112 are in engagement with a first gear 166 rotatably mounted on the lower car 114 or with a second gear 168 rotatably mounted on the lower car 114. A first brake element 170 is assigned to the first gear 166 and a second brake element 172 is assigned to the second gear 168. With the help of the brake elements 170, 172, the rotational movement of the gear wheels 166, 168 can be locked, provided the relative speed between the upper car 112 and the lower car 114 exceeds a maximum permissible relative speed. For this purpose, the two brake elements 170, 172 stand in a corresponding manner to that with reference to FIG Figure 2 explained brake elements 144, 146 with a control device, not shown in the drawing, of the elevator system 160 in electrical connection, which in turn is coupled to at least one sensor, with the aid of which the relative speed of the two cars 112, 114 can be determined. In Figure 3 To achieve a better overview, motors are not shown which each form a coupling drive and which move the toothed racks 162, 164 into their coupling position.

Below the maximum permissible relative speed, the vertical spacing of the two cars 112, 114 can thus be changed in a simple manner by means of the travel drives 126, 130 in the coupled state. However, if the actual relative speed exceeds the maximum permissible relative speed, the gears 166, 168 are locked, so that the two cars 112, 114 are rigidly coupled to one another via the racks 162, 164 and the locked gears 166, 168. As an alternative or in addition to the at least one sensor 152, the speed of the gearwheels 166, 168 could also be detected in order to determine the relative speed of the cars 112, 114.

In Figure 4 A fourth advantageous embodiment of an elevator installation according to the invention is shown schematically, which is denoted overall by reference numeral 180. The elevator system 180 is largely identical to that in reference to FIG Figure 2 Elevator system 110 shown. For identical components, therefore, in Figure 4 uses the same reference numerals as in Figure 2 and with regard to these components, reference is made to the explanations above in order to avoid repetition.

At the in Figure 4 In the illustrated elevator system 180, the coupling between the upper car 112 and the lower car 114 takes place with the aid of a large number of mechanical coupling elements which form a support chain 182. The support chain 182 is positioned on the lower car 114 and can be moved with the aid of an in Figure 4 to achieve a better overview of the coupling drive, not shown, are moved back and forth between a compact supply position and differently extended coupling positions. In the supply position, the support chain 182 is almost completely immersed in a support chain housing 188, the support chain links 190 being largely arranged horizontally next to one another and an upper support chain section being positioned above a lower support chain section. From the compact supply position, the support chain 182 can be extended into an Figure 4 shown coupling position are moved in which they out of the support chain housing 188 in partially protrudes in the vertical direction, a plurality of support chain links 190 being arranged vertically one above the other.

An influencing member in the form of a gear wheel 184 is in engagement with the support chain 182. The gear 184 arranged on the lower car 114 can be braked and locked by a controllable braking element 186. A free end of the support chain 182 can be fixed on the upper car 112 with the aid of a connecting device 192 in order to couple the two cars 112, 114 to one another. For this purpose, the connecting device 192 can have connecting elements which interact with one another and, in addition, a controllable locking element can be used, with the aid of which the connecting elements can be locked. Such connecting elements and locking members are known per se to the person skilled in the art and therefore do not require any further explanation in the present case. In the coupled state, the vertical distance between the two cars 112, 114 can be changed in a simple manner with the aid of the two travel drives 126, 130, provided that the relative speed between the two cars 112, 114 does not exceed a maximum permissible relative speed. If there is such a low relative speed, the movement of the gear wheel 184 is not impaired by the braking element 186, so that their distance from one another can be changed by a relative movement of the two cars 112, 114. However, if the relative speed exceeds the maximum permissible relative speed, then the gear 184 is braked and locked by means of the braking element 186. There is then a rigid coupling between the upper car 112 and the lower car 114, wherein, in particular, compressive forces can be transmitted between the two cars 112, 114 via the support chain 182.

Also in the elevator system 180, the cars 112, 114 can thus be moved separately from one another in the shaft 116 in a first operating mode of the elevator system 180, wherein they have a safety distance from one another which ensures that when the two cars 112, 114 move in series, the rear one in the direction of travel Even then, the car is reliable without Risk of collision can be braked if the front car brakes suddenly in the event of a malfunction. If the two cars 112, 114 are to be at a short distance from one another, they can be coupled to one another in a second operating mode of the elevator system 180 by means of the support chain 182, the gearwheel 184 and the brake element 186, their relative distance at low relative speeds by means of the travel drives 126 , 130 can be changed in order to adapt the vertical distance between the cars 112, 114 to different floor distances. To change the distance, the support chain 182 can be moved back and forth between its compact storage position and coupling layers of different dimensions. At high relative speeds, such as can occur in the event of a fault, in which the front car suddenly brakes in the direction of travel, the support chain 182 is locked so that its length cannot be changed, and consequently the cars 112, 114 cannot collide with one another.

Claims (16)

1. Elevator installation having a shaft (16; 116), in which at least two lift cars (12, 14; 112, 114) are arranged above one another and can be moved separately from one another upwards and downwards in the vertical direction, each lift car (12, 14; 112, 114) being assigned a drive (26, 30; 126, 130) for moving the lift car (12, 14; 112, 114), it being possible for at least two lift cars (12, 14; 112, 114) to be coupled to one another via a variable-length releasable coupling device (34; 134), characterized in that the spacing between the lift cars (12, 14; 112, 114) which are coupled to one another is variable with the aid of at least one of the drives (26, 30; 126, 130) in a manner which is dependent on the relative speed between the two lift cars (12, 14; 112, 114).
2. Elevator installation according to Claim 1, characterized in that the spacing between the lift cars (12, 14; 112, 114) which are coupled to one another is variable at relative speeds up to a predefinable or predefined maximum permissible relative speed.
3. Elevator installation according to Claim 1 or 2, characterized in that the spacing between the lift cars (12, 14; 112, 114) which are coupled to one another is variable with the aid of the drives (26, 30; 126, 130) of all coupled lift cars (12, 14; 112, 114) in a manner which is dependent on the relative speed between the lift cars (12, 14; 112, 114) .
4. Elevator installation according to one of the preceding claims, characterized in that the coupling device (34; 134) comprises at least one motorized coupling drive (98; 148, 150) for establishing and releasing the coupling between the lift cars (12, 14; 112, 114) which can be coupled to one another.
5. Elevator installation according to one of the preceding claims, characterized in that the coupling device comprises at least one movable coupling member (36, 38) which is assigned an influencing member (76, 78) for influencing the movement of the coupling member (36, 38) in a manner which is dependent on the relative speed between the lift cars (12, 14; 112, 114) which are coupled to one another.
6. Elevator installation according to Claim 5, characterized in that the speed of the coupling member (36, 38) can be limited by means of the influencing member (76, 78).
7. Elevator installation according to Claim 5 or 6, characterized in that the coupling member (36, 38) can be locked by means of the influencing member (76, 78).
8. Elevator installation according to Claim 5, 6 or 7, characterized in that tensile and compressive forces can be transmitted via the at least one coupling member (36, 38) between the lift cars (12, 14) which are coupled to one another.
9. Elevator installation according to one of Claims 5 to 8, characterized in that the coupling device (34) comprises a plurality of coupling members (36, 38) of identical configuration.
10. Elevator installation according to one of Claims 5 to 9, characterized in that the at least one coupling member comprises a hydraulic or pneumatic piston/cylinder assembly (36, 38) with a double-acting cylinder (40, 52), and in that the influencing member is configured as a compensation device (68), it being possible for that annular space (48, 60) of the piston/cylinder assembly which surrounds a piston rod (44, 56) to be connected to that piston space (50, 62) of the piston/cylinder assembly which is arranged on a piston (42, 54) on the end side via the compensation device (68) in a manner which is dependent on the relative speed between the two lift cars (12, 14) which are coupled to one another.
11. Elevator installation according to Claim 10, characterized in that the compensation device (68) comprises at least one throttle or locking element (76, 78, 88, 94) which can be controlled in a manner which is dependent on the relative speed between the lift cars (12, 14) which are coupled to one another.
12. Elevator installation according to one of Claims 5 to 9, characterized in that the at least one coupling member comprises a first mechanical coupling element (136, 140; 162, 164) and a second mechanical coupling element (138, 142; 166, 168) which can be brought into engagement with one another and can be moved relative to one another, and in that the influencing member comprises at least one controllable brake element (144, 146; 170, 172), it being possible for the relative movement of the two coupling elements to be braked and/or locked by means of the at least one brake element (144, 146; 170, 172) in a manner which is dependent on the relative speed between the two lift cars (112, 114).
13. Elevator installation according to Claim 12, characterized in that the first mechanical coupling element is configured as a threaded spindle (136, 140) which is mounted on a first one of the lift cars (112) which can be coupled to one another such that it can be rotated about its longitudinal axis, and in that the second coupling element is configured as a threaded nut (138, 142) which is held on a second one of the lift cars (114) which can be coupled to one another, which threaded nut (138, 142) can be brought into engagement with the threaded spindle (136, 140), it being possible for the rotational speed of the threaded spindle (136, 140) to be limited and/or locked by means of the at least one controllable brake element (144, 146) in a manner which is dependent on the relative speed between the two lift cars (112, 114).
14. Elevator installation according to Claim 12, characterized in that the first mechanical coupling element is configured as a rack (162, 164) which is held on a first one of the lift cars (112) which can be coupled to one another, and in that the second mechanical coupling element is configured as a gearwheel (166, 168) which is mounted rotatably on a second one of the lift cars (114) which can be coupled to one another, which gearwheel (166, 168) can be brought into engagement with the rack (162, 164), and the rotational speed of which gearwheel (166, 168) can be limited and/or locked by means of the at least one controllable brake element (170, 172) in a manner which is dependent on the relative speed between the two lift cars (112, 114).
15. Elevator installation according to one of Claims 5 to 9, characterized in that the at least one coupling member comprises a plurality of mechanical coupling elements (190) which are arranged on a first one of the lift cars (112) which can be coupled to one another, which mechanical coupling elements (190) are connected movably to one another and can be coupled releasably to a second one of the lift cars (114) which can be coupled to one another, it being possible for the coupling elements (190) to be moved to and from between a compact storage position and coupling positions of different extent, and it being possible for the said coupling elements (190) to be braked and/or locked by means of the influencing member (184) in a manner which is dependent on the relative speed between the two lift cars (112, 114) .
16. Elevator installation according to Claim 15, characterized in that the mechanical coupling elements (190) configure a supporting chain (182), and in that the influencing member is configured as a gearwheel (184) which can be braked and/or locked, and is in engagement with the supporting chain (182).

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