Patent Publication Number: US-2017369280-A1

Title: Buffering device for multiple-car elevator system

Description:
FIELD OF INVENTION 
     The subject matter disclosed herein relates generally to the field of elevators and, more particularly, to a multi-car elevator system. 
     BACKGROUND 
     Ropeless elevator systems, also referred to as “self-propelled elevator systems,” are useful in certain applications (e.g., high-rise buildings) where the mass of the ropes for a roped system is prohibitive and there is a desire for multiple elevator cars to travel in a single lane of a hoistway. There exist ropeless elevator systems in which a first lane is designated for upward-traveling cars and a second lane is designated for downward-traveling cars. A transfer station at each end of the hoistway is used to move cars horizontally between the first lane and second lane. 
     BRIEF DESCRIPTION OF INVENTION 
     According to a non-limiting exemplary embodiment of the invention, an elevator system includes a first elevator car supported for vertical movement in a lane of a hoistway. A second elevator car is configured to operate and move vertically in the lane below the first elevator car independently thereof. At least one buffering device is supported on at least one of the elevator cars to absorb energy upon contact between each buffering device and the other elevator car. 
     In an aspect of the embodiment, at least one buffering device is positioned on at least a top portion of the second elevator car and facing toward the first elevator car, and/or at least one buffering device is positioned on at least a bottom portion of the first elevator car and facing toward the second elevator car. In a version of this aspect, at least one buffering device is positioned at least at an upper or a lower part of a linear motor system of at least one of the elevator cars. 
     In another aspect, at least one first buffering member is positioned on a bottom portion of the first elevator car, and/or at least one second buffering member is positioned on a top portion of the second elevator car. In a version of this aspect, at least one first buffering member is positioned on a bottom portion of the first elevator car, at least one corresponding second buffering member is positioned on a top portion of the second elevator car, and corresponding ones of the first and second buffering members contact each other upon contact between the first and second elevator cars. In an example of this version, the first buffering member includes a reaction plate, and the second buffering member includes a buffer. 
     In still another aspect, each buffering device is mechanical, electric, magnetic, or any combination thereof. In a version of this aspect, the buffering device includes a spring, a shock absorber (including fluid or not), an electromechanical device, or a repulsive-magnetic-force-generating component. 
     In yet another aspect, the buffering device is equipped with a sensor to detect the contact, integrity, and/or operability (in a non-contacting state) of the buffering device. The detection and/or a condition of the buffering device are/is readable by a sub-system of the elevator system. 
     Each buffering device dissipates or minimizes the energy transmitted from one of the elevator cars to the other if the elevator cars contact each other in the lane during operation of the elevator system. In this way, the buffering device manages the mechanical energy of the contact, allowing for safe operation of the elevator system and travel of the elevator cars to respective successive floors of, for example, a high-rise building. Also, reactive forces between the elevator cars are generated, and resetting of the buffering device(s) is not required. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
       The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawing in which: 
         FIG. 1  schematically depicts a non-limiting exemplary embodiment of a multiple-car, ropeless elevator system; 
         FIG. 2  schematically depicts operation of a buffering device of a multiple-car, ropeless elevator system according to a non-limiting exemplary embodiment of the invention; 
         FIG. 3  depicts the buffering device according to the embodiment illustrated in  FIG. 2  implemented with a frameless car; and 
         FIG. 4  depicts the buffering device according to the embodiment illustrated in  FIG. 2  implemented with a framed car. 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
       FIG. 1  depicts a non-limiting exemplary embodiment of a multi-car, ropeless elevator system  10 . However, it should be understood that the elevator system  10  is not limited to being ropeless. By way of example only, the elevator system  10  can be roped such that buffering devices described below and shown in the figures can be implemented with a roped multi-car system. Also, the buffering devices can be implemented with a ropeless multi-car system that does not include a linear motor. 
     As shown in  FIG. 1 , the elevator system  10  includes a hoistway  11  having a plurality of lanes  13 ,  15 ,  17 . While three lanes  13 ,  15 ,  17  are shown in  FIG. 1 , it should be understood that other embodiments of the elevator system  10  may have any suitable respective number of lanes. In each lane  13 ,  15 ,  17 , one or more elevator cars  14  travel in one direction (i.e., up or down). For example, in  FIG. 1 , the cars  14  in lanes  13  and  15  travel up, and the cars  14  in lane  17  travel down. 
     Above the top floor of the hoistway  11  is an upper transfer station  30  to impart horizontal (or lateral) motion to the cars  14  to move the cars  14  between and among the lanes  13 ,  15 ,  17 . It should be understood that the upper transfer station  30  may be located at the top floor rather than above the top floor. Below the first floor of the hoistway  11  is a lower transfer station  32  to impart horizontal motion to the cars  14  to move the cars  14  between and among the lanes  13 ,  15 ,  17 . It should be understood that the lower transfer station  32  may be located at the first floor rather than below the first floor. Although not shown in  FIG. 1 , at least one intermediate transfer station may be used between the first and top floors. Each intermediate transfer station is similar to the upper and lower transfer stations  30 ,  32 . 
     The cars  14  are propelled using a linear-magnetic-motor system having a primary, fixed portion  16  and a secondary, moving portion  18 . The primary portion  16  includes windings or coils mounted at at least one side of each lane  13 ,  15 ,  17 . The primary portion  16  also is supplied with drive signals to control movement of the cars  14  in their respective lanes. The secondary portion  18  includes permanent-magnet arrays mounted to at least one side of each car  14  and is designed to react to large loads. 
     As shown in  FIG. 1 , adjacent lanes  13 ,  15 ,  17  share a guiderail such that, for example, an interior side of the car  14  in lane  13  and a corresponding side of the car  14  in lane  15  travel along a common guiderail. Also as shown in  FIG. 1  and described below, in each lane  13 ,  15 ,  17 , at least one lower car  14  is positioned below an upper car  14 , both cars  14  configured to move within the lane  11  as known. 
     It should be understood that the elevator system  10 , in general, and the hoistway  11 , upper and lower transfer stations  30 ,  32  (and any intermediate transfer station), and linear motor system, in particular, can have any suitable structure. It should be understood also that the hoistway  11 , lanes  13 ,  15 ,  17 , upper and lower transfer stations  30 ,  32  (and any intermediate transfer station), and linear motor system can have any suitable relationship with each other. It should be understood also that each of the cars  14  can move within the hoistway  11  and in the corresponding lane  13 ,  15 ,  17  in any suitable manner. It should be understood also that any suitable number of cars  14  can travel in a corresponding lane in any suitable direction. It should be understood also that each of the transfer stations  30 ,  32  can impart horizontal motion to the cars  14  in any suitable manner. It should be understood also that the cars  14  can be propelled using any suitable propulsion system—e.g., an on-board propulsion (e.g., on-board rotary magnetic screws) such that structure of each car  14  may be more similar to that of a conventional rope-elevator car including a frame through which propulsion is directed. It should be understood also that, in the case of a ropeless elevator system, the cars  14  thereof can be propelled using any suitable propulsion system as well. 
       FIG. 2  depicts operation of a buffering device  34  of the elevator system  10  according to a non-limiting exemplary embodiment. In the figure, an upper or first car  14   a  is supported for vertical movement in a corresponding lane  13 ,  15 ,  17 . A lower or second car  14   b  is configured to operate and move vertically in the lane  13 ,  15 ,  17  below the first car  14   a  independently of the first car  14   a . At least one buffering device  34  is supported on at least one of the cars  14   a ,  14   b  to absorb energy upon contact between each buffering device  34  and the other car  14   a ,  14   b . The figure shows the two cars  14   a ,  14   b  nearly in contact with each other and including respectively four buffering devices  34 . It should be understood that, in the case in which the elevator system  10  includes more than two cars  14  in a particular lane  13 ,  15 ,  17 , “first and second cars  14   a ,  14   b ” refer to any pair of adjacent ones of these three or more cars  14 . 
     In an aspect, at least one buffering device  34  is positioned on at least a top portion of the second car  14   b  and facing toward the first car  14   a , and/or at least one buffering device  34  is positioned on at least a bottom portion of the first car  14   a  and facing toward the second car  14   b . In a version of this aspect and as shown in  FIG. 2 , a pair of buffering devices  34  are supported on a top portion of each of the cars  14   a ,  14   b  substantially in-line with the secondary portion  18  of the linear motor system, and a pair of buffering devices  34  are supported on a bottom portion of each of the cars  14   a ,  14   b . In this example, the pair of buffering devices  34  supported on the top portion of the second car  14   b  and the pair of buffering devices  34  supported on the bottom portion of the first car  14   a  are configured to respectively contact each other upon contact between with the cars  14   a ,  14   b  to, thereby, absorb the contact. 
       FIG. 3  depicts one or more buffering devices  34  implemented with a frameless car  14 . In an aspect, the car  14  includes a cabin  50 , and the linear motor system of the car  14  is supported on the cabin  20 . (Again, it should be understood that the linear motor system is only one possible vertical propulsion system for the elevator system  10 .) A buffering device  34  is positioned at least at an upper or a lower part of a portion of the linear motor system. More specifically, permanent-magnet arrays  36  of the secondary portion  18  of the linear motor system are shown mounted to opposite corners of opposed exterior side walls  38  of the car  14 . In a version of this aspect and as shown in the figure, at each corner, a buffering device  34  is positioned at both the upper and lower parts of the secondary portion  18 . In particular, a pair of buffering devices  34  are mounted to opposed upper and lower ends of the secondary portion  18  such that the buffering devices  34  are aligned with the secondary portion  18  and extend beyond respective opposed exterior end walls  40  of the car  14 . In this way, in a two-car scenario, the buffering devices  34  mounted to the upper ends of the secondary portion  18  of the second car  14   b  are configured to contact the buffering devices  34  mounted to the lower ends of the secondary portion  18  of the first car  14   a  upon contact between with the cars  14   a ,  14   b  to, thereby, absorb the contact. 
       FIG. 4  depicts one or more buffering devices  34  implemented with a framed car  14  (which can be employed in a roped or ropeless multi-car elevator system). The cabin  20  of the car  14  is supported in a known manner on a frame  42  such that members of the frame  42  are operatively mounted to respective exterior side and end walls  38 ,  40  of the cabin  20 . (The frame  42  can connect to a roped or ropeless propulsion system that is not shown directly in  FIG. 4 .) In an aspect, at least one buffering device  34  is positioned at least at an upper or a lower end of the frame  38 . More specifically, the frame  42  includes a crosshead beam  42   a  along a top of the frame  42  and a plank beam  42   b  along a bottom of the frame  42 . In a version of this aspect and as shown in the figure, a pair of buffering devices  34  are supported at or near each of the beams  42   a ,  42   b  and arranged substantially perpendicular to the respective beam  42   a ,  42   b  so that the buffering devices  34  extend upward or downward and beyond the respective beam  42   a ,  42   b . Toward that end, a pair of corresponding buffer supports (not shown) can be arranged on each of the crosshead and plank beams  42   a ,  42   b  for supporting the buffering devices  34 . In this way, in the two-car scenario, the pair of buffering devices  34  supported at or near the crosshead beam  42   a  of the second car  14   b  are configured to contact the buffering devices  34  supported at or near the plank beam  42   b  of the first car  14   a  upon contact between with the cars  14   a ,  14   b  to, thereby, absorb the contact. 
     It should be understood that, although structure of the frame  42  and various members of the frame  14  shown are conventional, they can be of any suitable structure. It should be understood also that the frame  42  can be operatively mounted to the cabin  20  in any suitable manner. It should be understood also that, in the case of a frameless elevator system, each buffering device  34  is positioned at least at a top or bottom structure of the elevator system. In an aspect of this case, the buffering device  34  is arranged substantially perpendicular to the respective top or bottom structure so that the buffering device  34  extends beyond the structure. 
     Returning to  FIG. 2 , in an aspect, the buffering device  34  includes a plurality—in particular, a pair—of members. At least one first buffering member  34   a  is positioned on a bottom portion of the first car  14   a , and/or at least one second buffering member  34   b  is positioned on a top portion of the second car  14   b . In a version of this aspect, the first buffering member  34   a  includes a reaction plate  34   a , and the second buffering member  34   b  includes a corresponding buffer  34   b . The reaction plate  34   a  is configured to interact with the buffer  34   b  in the event that the cars  14   a ,  14   b  contact each other. As such, the reaction plate  34   a  is sufficiently strong to act as a reaction surface for the buffer  34   b . The reaction plate  34   a  and buffer  34   b  operate to dissipate energy associated with such contact. In the example shown, a pair of reaction plates  34   a  are positioned on the bottom portion of the first car  14   a , and a corresponding pair of buffers  34   b  are positioned on the top portion of the second car  14   b . Of course, it should be understood that positioning of the reaction plates  34   a  and buffers  34   b  can be reversed so that the pair of reaction plates  34   a  are positioned on the top portion of the second car  14   b  and the corresponding pair of buffers  34   b  are positioned on the bottom portion of the first car  14   a.    
     Each buffering device  34 , as an energy-absorbing device, can be made of any suitable number and kind of materials. For instance, each buffering device  34  can be mechanical, electric, magnetic, or any combination thereof. In an aspect, the buffering device includes a spring, a shock absorber (including fluid or not), an electromechanical device, or a repulsive-magnetic-force-generating component. Also, in an aspect, the buffering device  34  is equipped with a sensor—such as a microswitch—to detect the contact, which detection is readable by, for example, an integrity-management system of the elevator system  10 . The sensor detects further integrity and/or operability (in a non-contacting state) of the buffering device  34 , and a condition or health of the buffering device  34  is readable by a sub-system of the elevator system  10  as well. 
     In operation, each buffering device  34  is configured to contact a car  14  or another buffering device  34  as two cars  14  come together either during normal operation, such as during landing of the cars  14  at respective successive floors of the hoistway  11  (or otherwise in connection with primary motion control of the cars  14 ). Upon such contact, the buffering device  34  progressively deforms, thereby effectively dissipating energy associated with the contact. In this way, the buffering device  34  manages potential energy of contact between the cars  14  and can act as a safety back-up to a primary motion controller of the elevator system  10 . The sensor detects the contact, which is readable by the integrity-management system of the elevator system  10 . 
     The buffering device  34  can be a multiple-use device or frangible. Also, a simple visual inspection of each buffering device  34  can confirm that the buffering device  34  is intact and operative. The integrity-management system also can be used to verify integrity of the buffering device  34 . 
     Each buffering device  34  dissipates or minimizes the energy transmitted from one of the cars  14  to the other car  14  if the cars  14  contact each other in the lane  13 ,  15 ,  17  during operation of the elevator system  10 . In this way, the buffering device  34  manages the mechanical energy of the contact, allowing for safe operation of the elevator system  10  and travel of the cars  14  to respective successive floors of, for example, a high-rise building. Also, reactive forces between the cars  14  are generated, and resetting of the buffering device(s)  34  is not required. 
     In the above embodiments, the buffering devices  34  are on the top and/or bottom of cars  14  to absorb energy in a vertical direction. Similar buffering devices  34  may be employed in the transfer stations  30  and/or  32  to dissipate or minimize the energy transmitted from one of the cars  14  to the other car  14  in a horizontal direction. In such embodiments, the buffers may be positioned on holding carriages within the transfer station that carry and transport the cars  14  horizontally. 
     While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions, or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various non-limiting embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.