Abstract:
An elevator has an elevator car supporting frame that can travel in a travel space provided for a journey of the elevator car supporting frame. The elevator installation is also provided with a first elevator car and a second elevator car arranged on the elevator car supporting frame. Furthermore, a hydraulic moving element is arranged in a lower end region of the travel space. In this way, the first elevator car can be moved in relation to the second elevator car, by the moving device, in the lower end region of the travel space.

Description:
FIELD 
     The invention relates to an elevator system having at least one elevator car support that can hold two or more elevator cars. The invention relates specifically to the field of elevator systems designed as so-called double-decker elevator systems. 
     BACKGROUND 
     JP 10-236753 A discloses a double-decker elevator. The known elevator has two cars which are arranged one above the other in a car frame. The two cars can hereby move relative to each other. For this purpose, hydraulic cylinders are arranged in a counterweight frame. A traction cable which is connected at one end to the counterweight frame and at the other end to the car frame is guided over a drive pulley. Moreover, a second cable in addition to the traction cable is guided over a freewheeling pulley and is connected at one end to the hydraulic cylinders and at the other end to one of the cars. When the hydraulic cylinders actuate the second cable, the cars are moved relative to each other. 
     The double-decker elevator known from JP 10-236753 A has the disadvantage that it has a complex design. On the one hand, the design of the counterweight frame is complex because the hydraulic cylinders move with the counterweight frame through the elevator shaft, which requires an additional control means. Moreover, a cable guide for the second cable is additionally needed. Elongation or shortening of the traction cable and the second cable, occurring during operation, are hereby also possible, which results in undesired relative movement between the two elevator cars. 
     SUMMARY 
     An object of the invention is to provide an elevator system which has an improved structure. Specifically, an object of the invention is to provide an elevator system that permits relative movement between at least two elevator cars with a relatively low degree of complexity. 
     The elevator system is thus with at least one elevator car support which displaceable in a travel space provided for the travel of the elevator car support. A first elevator car is arranged the on the elevator car support. At least a second elevator car is additionally arranged on the elevator car support. An adjusting device is arranged in a lower end region of the travel space, it being possible to adjust the first elevator car in the lower end region of the travel space relative to the second elevator car in the direction of travel using the adjusting device. 
     In the design of the elevator system, the elevator car support can be arranged in an elevator shaft that defines the travel space, a drive motor unit being provided which serves to actuate the elevator car support. As a result, the elevator car support can be displaced along the travel path provided. The elevator car support can hereby be suspended from a traction means connected to the elevator car support. The traction means can hereby be guided in a suitable fashion over a drive pulley of the drive motor unit. As well as having the function of transmitting the force or the torque from the drive motor unit to the elevator car support in order to actuate the elevator car support, the traction means can here also have the function of carrying the elevator car support. Actuation of the elevator car support is hereby understood in particular as raising or lowering the elevator car support, it being possible for the elevator car support to be guided by one or more guide rails. 
     It is advantageous that the first elevator car can be fixed with respect to the second elevator car, and that the first elevator car can be unfixed with respect to the second elevator car in the lower end region of the travel space. It is also hereby advantageous that the elevator car support comprises a first elevator car support part and a second elevator car support part, that the first elevator car is connected to the first elevator car support part, that the second elevator car is connected to the second elevator car support part, and that a connecting and locking device is provided which connects the first elevator car support part to the second elevator car support part in the closed state and disconnects them in the open state. In the closed state, the elevator car support with the two elevator cars can be displaced through the travel space, a constant distance being maintained between the elevator cars. For example, upper floors situated one above the other can each have the same inter-floor distance. As a result, in the closed state, people can enter and leave both elevator cars on the respective floors. A basement or a lobby may, for example, be located in the lower end region of the travel space. Disconnecting the two elevator car support parts can hereby adjust the two elevator cars relative to each other. In the open state, the first elevator car can hereby in particular be lowered and positioned. People can then enter and leave both elevator cars according to the floor to which they have moved. The first elevator car with the first elevator car support part can then be raised again. The connecting and locking device can then reconnect the two elevator car support parts. 
     It is hereby also advantageous that the connecting and locking device has at least one connecting element that interacts in the closed state with a connection point of the first elevator car support and/or with a connection point of the second elevator car support part. The connecting element can, for example, have a bar-like design and in the closed state be guided through bores which are formed in the elevator car support parts. In order to disconnect the elevator car support parts, the connecting element can be withdrawn from the through bores so that the open state is assumed. 
     It is moreover advantageous that the connecting and locking device is arranged on the second elevator car support part. The adjusting device advantageously serves to adjust the first elevator car support part with the first elevator car. By arranging the connecting and locking device on the second elevator car support part, the load on the adjusting device is removed as the weight of the connecting and locking device in the open state then does not act on the first elevator car support part. 
     A braking and/or retaining device is advantageously provided that serves to fix the second elevator car in the travel space when the first elevator car is adjusted relative to the second elevator car. The second elevator car can, for example, hereby be fixed via the second elevator car support part. It is hereby also advantageous that the braking and/or retaining device interacts with an elevator shaft and/or with a guide rail. The braking and/or retaining device for fixing the second elevator car in the travel space can thus interact with a building structure or the like. When the two elevator cars are disconnected, only the weight of the second elevator car and possibly other components connected to the second elevator car, in particular the second elevator car support, acts on the traction means. The load on the traction means is thereby removed at one end. However, the load of for example a counterweight is applied to the traction means at the other end, so that the differential force is present at the drive pulley. This means that the drive pulley must be designed accordingly, so that the second elevator car is not displaced upwards through the elevator shaft. The second elevator car can, however, be fixed by the braking and/or retaining device so that a force equilibrium is achieved. 
     It is also advantageous that the adjusting device is designed as a hydraulic adjusting device. As a result, inter alia, comfortable operation is enabled which is smooth and free of vibration. 
     It is moreover advantageous that the adjusting device is arranged in a pit of an elevator shaft and/or that the adjusting device is connected to a bottom of the elevator shaft. A simple design and advantageous alignment of the adjusting device are hereby possible. Specifically, compressive forces that occur can be reliably absorbed and a compressive force that acts in order to make adjustments can advantageously be transferred onto the first elevator car from the adjusting device. 
     It is moreover advantageous that the first elevator car and the second elevator car have a minimum base distance in a ready-to-travel state in which the elevator car support can be displaced through the travel space. The first elevator car can be lowered in a controlled fashion in the lower end region of the travel space, as a result of which the distance between the elevator cars increases with respect to the minimum base distance. After people have entered and left the elevator cars, the first elevator car can then be raised again until the minimum base distance between the two elevator cars has been restored. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Preferred exemplary embodiments of the invention are explained in more detail in the following description with the aid of the attached drawings, in which corresponding elements are provided with matching reference numerals. In the drawings: 
         FIG. 1  shows a schematic representation of an elevator system in accordance with a first exemplary embodiment of the invention in a closed state of a connecting and locking device, and 
         FIG. 2  shows the elevator system shown in  FIG. 1  in an open state of the connecting and locking device. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an elevator system  1  having at least one elevator car support  2  that can be displaced in a travel space  3  provided for the travel of the elevator car support  2 . The travel space  3  is provided in an elevator shaft  4  of a building. Several floors  5 ,  6  are provided, which represent stopping points  5 ,  6 . The floors  5 ,  6  are hereby the two lowest floors of the elevator system  1 . There are usually a larger number of other floors or stopping points above the floors  5 ,  6 . 
     In this exemplary embodiment, the elevator car support  2  has a first elevator car support part  7  and a second elevator car support part  8 . The elevator car support  2  has sheaves  9 ,  10  which are attached to the second elevator car support part  8 . A traction means  11  is guided around the sheaves  9 ,  10 . The traction means  11  moreover runs around a drive pulley  12  of a drive motor unit  13 . According to the current direction of rotation of the drive pulley  12  driven by the drive motor unit  13 , the elevator car support  2  is displaced upwards or downwards through the travel space  3 . The elevator car support  2  with the two elevator car support parts  7 ,  8  can thus travel through the travel space  3 . 
     The elevator car support  2  holds a first elevator car  15  and a second elevator car  16 . The first elevator car  15  is hereby arranged on the first elevator car support part  7  and connected to it. Moreover, the second elevator car  16  is arranged on the second elevator car support part  8  and connected to it. The first elevator car  15  has an exit level  17 . The second elevator car  16  also has an exit level  18 . A distance  19  is defined between the two exit levels  17 ,  18 . In the base position shown in  FIG. 1 , a minimum base distance  20  between the two elevator cars  15 ,  16  is provided, so that the distance  19  is also minimal. The distance  19  is hereby set to the usual distance between floors that is needed for the higher-situated floors. The distance  19  is, however, smaller than an inter-floor distance  21  between the floors  5 ,  6  which are the lowest floors. 
     In order to move to the floors  5 ,  6 , the elevator car support  2  is moved to a lower end region  22  by corresponding actuation of the drive pulley  12  in such a way that the exit level  18  of the second elevator car  16  is positioned at the floor  6 . In this position of the elevator car support  2 , shown in  FIG. 1 , the exit level  17  of the first elevator car  15  is, however, situated above the floor  5  because the distance  19  is smaller than the inter-floor distance  21 . 
     When the second elevator car  16  stops at the floor  6 , the first elevator car  15 , which is arranged in the first elevator car support part  7 , is situated in the lower end region  22  of the travel space  3 . The elevator shaft  4  has a pit  23  below the second elevator car support part  8 . A hydraulic adjusting element  24 , which has a cylinder  25  and a piston, guided in the cylinder  25 , with a piston rod  26 , is arranged in the pit  23 . The piston rod  26  can hereby be adjusted upwards in a direction  27  or downwards in a direction  28 . In the position of the elevator car support  2  which has been shown, the piston rod  26  has been adjusted upwards in the direction  27  until a plate-Vice end piece  29  connected to the piston rod  26  bears against the underside  30  of the first elevator car support part  7 . The plate-like end piece  29  can hereby also already be positioned in this position so that the elevator car support  2  travels as far as the plate-like end piece  29 . 
     The elevator system  1  has a connecting and locking device  35 . The connecting and locking device  35  is arranged on the elevator car support  2 . In this exemplary embodiment, the connecting and locking device  35  is arranged on the second elevator car support part  8  and connected to the second elevator car  16 . Moreover, the elevator system  1  has a braking and/or retaining device  36  for the second elevator car  16 . The braking and/or retaining device  36  in this exemplary embodiment is hereby connected to the second elevator car support part  8 . A guide rail  37 , on which the elevator car support  2  is guided in a suitable fashion, is arranged in the elevator shaft  4 . Specifically, guidance during actuation by the drive motor unit  13  is ensured thereby. Moreover, the two elevator car support parts  7 ,  8  can each be guided independently on the guide rail  37 . Further guide rails can hereby also be provided. The braking and/or retaining device  36  interacts with the guide rail  37 . The braking and/or retaining device  36  hereby ensures that the second elevator car  16 , which is arranged in the second elevator car support part  8 , is fixed to the guide rail  37  and thus relative to the travel space  3 . 
     The design of the elevator system  1  is described in more detail below with reference to  FIG. 2 . 
       FIG. 2  shows the elevator system  1  of the exemplary embodiment, when the connecting and locking device  35  is in an open state and when the braking and/or retaining device  36  is in an activated state. In contrast,  FIG. 1  shows the elevator system, when the connecting and locking device  35  is in a closed state and when the braking and/or retaining device  36  is in a deactivated state. 
     When the first elevator car  15  is supported on the hydraulic adjusting element  24  via the first car support part  7 , the braking and/or retaining device  36  is actuated, The unactuated state of the braking and/or retaining device  36  is hereby shown in  FIG. 1  and the actuated state in  FIG. 2 . A pair of brake shoes of the braking and/or retaining device  36  hereby interacts with the guide rail  37 , for example. As a result, the second elevator car support part  8  is fixed to the second elevator car  16  immovably in the travel space  3 . 
     The connecting and locking device  35  has connecting elements  38 ,  39 . In the closed state, the connecting elements  38 ,  39  are extended so that they connect the elevator car support parts  7 ,  8  together. The connecting element  38  hereby interacts with the first elevator car support part  7  at a connection point  40 , and with the second elevator car support part  8  at a connection point  41 . Through bores can, for example, hereby be provided at the connection points  40 ,  41  in the elevator car support parts  7 ,  8 , into which through bores the connecting element  38  engages. In a corresponding fashion, connection points  42 ,  43  are also provided on the elevator car support parts  7 ,  8  for the connecting element  39 . In the closed state, the connecting element  39  interacts with the connection points  42 ,  43 . When the braking and/or retaining device  36  is activated, the connecting and locking device  35  is switched into the open state, the connecting elements  38 ,  39  being retracted. The retracted state is illustrated in  FIG. 2 . The elevator car support parts  7 ,  8  are disconnected as a result. The piston rod  26  with the plate-like end piece  29  then moves downwards in the direction  28 . This is achieved by the controlled draining of a pressurized fluid from the cylinder  25 . The first elevator car support part  7  hereby moves downwards with the first elevator car  15 . The distance  19  hereby increases. When the distance  19  is the same as the inter-floor distance  21 , the first elevator car support part  7  with the first elevator car  15  stops. The exit level  17  of the first elevator car  15  is now situated at the floor  5 . A distance  44  between the elevator cars  15 ,  16  has hereby increased with respect to the minimum base distance  20 . 
     In the situation shown in  FIG. 2 , people can enter and leave the two elevator cars  15 ,  16  from the respective floor  5 ,  6  to which they have moved. It is thus also possible for people to enter and leave the two elevator cars  15 ,  16  at the same time in the case of the inter-floor distance  21  which differs from the usual inter-floor distance of the other floors in the elevator shaft  4 . 
     After people have entered and left the elevator cars  15 ,  16 , the piston rod  26  is adjusted in the direction  27 . This is achieved by feeding pressurized fluid into the cylinder  25  by means of a pump. The distance  44  hereby decreases. When the distance  44  has reached the minimum base distance  20 , the connecting and locking device  35  is actuated in order to connect the two elevator car support parts  7 ,  8  together via the connecting elements  38 ,  39 . The braking and/or retaining device  36  is then deactivated. The situation shown in  FIG. 1  then reoccurs. The whole elevator car support  2  with the two elevator cars  15 ,  16  can then be displaced through the travel space  3  by the drive motor unit  13 . The two elevator cars  15 ,  16  are then moved to their destination floors. The minimum base distance  20  between the elevator cars  15 ,  16  is hereby predetermined in such a way that the distance  19  then corresponds again to the usual inter-floor distance. As a result, people may also enter and leave both elevator cars  15 ,  16  at the same time at the other floors. 
     Because the connecting and locking device  35  is arranged on the second elevator car support part  8 , its mass or its weight does not need to be moved or raised by the hydraulic adjusting element  24 . The same applies for the braking and/or retaining device  36  attached to the second elevator car support part. As a result, the design of the hydraulic adjusting element  24  can be optimized. This also affects other components, in particular a pump. On the other hand, the hydraulic adjusting element  24  is arranged immovably in the pit  23  so that the mass of the hydraulic adjusting element  24  does not need to be moved by the drive motor unit  13 . 
     The hydraulic adjusting element  24  is connected to a base  45  of the pit  23 . As a result, forces are transmitted advantageously, because the piston rod  26  is oriented parallel to the direction in which the weight of the first elevator car support part  7  with the first elevator car  15  acts. In this exemplary embodiment, the hydraulic adjusting element  24  forms a hydraulic adjusting device  24 . Depending on the design of the elevator system  1 , multiple hydraulic adjusting elements  24  can also be provided for forming the hydraulic adjusting device  24 . 
     The two elevator cars  15 ,  16  can thus have a minimum base distance  20  in a ready-to-travel state in which the elevator car support  2  can move through the travel space  3 . In the unlocked state, in which the elevator car support parts  7 ,  8  are disconnected, a distance  44  between the elevator cars  15 ,  16  can be achieved that is greater than the minimum base distance  20 . The second elevator car  16  can hereby be fixed by the braking and retaining device  36 . The first elevator car  15  can be adjusted with a high degree of efficiency. The adjustment by means of the hydraulic adjusting element  24  has minimal vibration and is very smooth. A high degree of comfort is achieved as a result. 
     The invention is not limited to the exemplary embodiments described. 
     In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.