Patent Publication Number: US-10766739-B2

Title: Assembly for actuating an elevator car brake

Description:
FIELD OF INVENTION 
     The subject matter disclosed herein relates generally to the field of elevators and, more particularly, to a multi-car, ropeless 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 and second lanes. 
     In these elevator systems, batteries or power rails, for example, power brakes to lift and hold the respective cars. Toward this end, the brakes are generally located on the respective movable cars, and control systems and drives are stationary and located in the hoistway. Operation of and communication between the brakes and corresponding drives are configured to be closely coordinated with each other. 
     BRIEF DESCRIPTION OF INVENTION 
     According to a non-limiting exemplary embodiment of the invention, an assembly for actuating and controlling braking of a car of an elevator system is provided. The assembly includes at least one braking device mounted on the car, supported between the car and a hoistway for movement with the car within the hoistway, and configured to apply a braking force to the car. The assembly also includes at least one corresponding actuator supported by the hoistway and configured to selectively engage the braking device to prevent movement of the car. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       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 a car portion of the embodiment of the elevator system illustrated in  FIG. 1 ; 
         FIG. 3A  schematically depicts a front view of a non-limiting exemplary embodiment of an assembly for actuating and controlling braking of a car of the embodiment of the elevator system illustrated in  FIG. 1 ; and 
         FIG. 3B  schematically depicts a top view of the embodiment of the brake-actuation-and-control assembly illustrated in  FIG. 3A . 
     
    
    
     DETAILED DESCRIPTION OF INVENTION 
       FIG. 1  depicts a non-limiting exemplary embodiment of a multi-car, ropeless elevator system  10 . 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 readily appreciated 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 motion to the cars  14  to move the cars  14  between and among the lanes  13 ,  15 ,  17 . It should be readily appreciated 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 readily appreciated 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 motor system having a primary, fixed portion  16  and a secondary, moving portion  18 . The primary portion  16  includes windings or coils mounted 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  12  (or safety rail  12 ) 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 readily appreciated 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 also be readily appreciated 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 also be readily appreciated 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 also be readily appreciated that any suitable number of cars  14  can travel in a corresponding lane in any suitable direction. It should also be readily appreciated that each of the transfer stations  30 ,  32  can impart horizontal motion to the cars  14  in any suitable manner. It should also be readily appreciated that the cars  14  can be propelled using any suitable propulsion system—e.g., an on-board propulsion (e.g., 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. 
       FIG. 2  schematically depicts a car portion of the embodiment of the elevator system  10 . Movement of the car  14  along the guiderails  12  is facilitated in a known manner, such as by a plurality of guide-roller devices (not shown). A braking force is applied to prevent undesired movement of each car  14 , such as when the car  14  is in an “over-speed” condition, stopped at a desired position and needs to be held there, or unexpectedly moved. 
     However, it should be readily appreciated that movement of the car  14  along the guiderails  12  can be facilitated in any suitable manner. It should also be readily appreciated that a braking force can be applied to prevent any suitable movement of the car  14 . 
     Toward that end, at least one safety or braking device  20  is supported between the car  14  and corresponding guiderail  12  for movement with the car  14  along the guiderail  12 . (In the figure, a pair of braking devices  20  are supported between the car  14  and corresponding guiderails  12  for such movement.) The braking device  20  can take the form of a bar, linkage, or any other suitable structure. In any event, the braking device  20  includes a base portion  22  that is directly or indirectly mounted on an appropriate portion, such as a frame member  24 , of the car  14 . The base portion  22  remains stationary relative to the car  14  and moves vertically with the car  14 . The braking device  20  includes also an opposed portion  26  that is directly or indirectly supported on an appropriate portion of the guiderail  12 . The opposed portion  26  remains stationary relative to the car  14  and moves vertically with the car  14  as well. The opposed portion  26  may include friction components (e.g., wedges) that engage the guiderail  12  to stop the car  14 . 
       FIGS. 3A and 3B  depict, respectively, front and top views of a non-limiting exemplary embodiment of an assembly  28  for actuating and controlling braking of the car  14 . The assembly  28  includes at least one blade or actuator  34  supported by the building in which the elevator system  10  resides. In an aspect of the embodiment, the actuator  34  is supported by a wall of the hoistway  11 . In a version of this aspect, the actuator  34  is supported by a corresponding guiderail  12 . Each braking device  20  is configured to selectively engage the actuator  34  to activate the braking device  20  to prevent undesired movement of the car  14 . More specifically, the actuator  34  is configured to be retracted to allow, for example, a downward traveling car  14  to move past the location of the actuator  34  in a corresponding “safe zone” of the hoistway  11 . When the actuator  34  is retracted, the braking device  20  is able to avoid contact with the actuator  34  and roll past the actuator  34  during movement of the car  14  to keep the braking device  20  in a position where the braking device  20  does not apply a braking force to the guiderail  12 . The actuator  34  is also configured to be extended to interfere with the corresponding braking device  20  to stop or hold the car  14 . When the actuator  34  is located, say, just below the car  14  and extended, any movement of the car  14  downward causes the braking device  20  to engage the actuator  34  and stop the car  14 . 
     In an aspect, a series of actuators  34  is located along the hoistway  11  each of which is capable of engaging a braking device  20 , regardless of location of the corresponding car  14  in the hoistway  11 . In a version of this aspect, to create the “safe zone,” a set of the series of actuators  34  is retracted such that a car  14  can move through the space created by the retracted set of actuators  34 . 
     In an aspect and as shown in these figures, each braking device  20  can include, for instance, self-locking wedge-style brake members that are situated for engaging the actuator  34 . In this way, the act of raising wedges of the braking device  20  of a downward traveling car  14  causes the wedges to clamp against the guiderail  12  to stop or hold the car  14 . Toward that end, the actuator  34  in this aspect is a clamp-type actuator  34  and shown in a retracted state in  FIG. 3B . The actuator  34  retracts to allow the car  14  to move past the location of the actuator  34  in the hoistway  11  or extends to interfere with a portion of (e.g., a linkage) the corresponding braking device  20  to trigger the brake device to stop or hold the car  14 . When the actuator  34  is located just below the car  14  and in the extended position, any movement of the car  14  downward causes the braking device  20  to engage the actuator  34 , activating the braking device  20  and stopping the car  14 . Movement of the car  14  upward disengages the wedges. 
     It should be readily appreciated that each of the guiderail  12 , braking device  20 , and actuator  34  can have any suitable structure and the guiderail  12 , car  14 , braking device  20 , and actuator  34  can have any suitable relationship with each other. For example, the braking device  20  can include instead rollers that are situated for engaging the actuator  34 . It should also be readily appreciated that one or both of the braking devices  20  can be operating at any given time. It should also be readily appreciated that, although the assembly  28  is described above in connection with only a downward traveling car  14  (i.e., controlling movement of a car  14  in only one direction), the assembly  28  can be suitably implemented with an upward traveling car  14  as well (i.e., controlling movement of the car  14  in both directions). 
     Under selected conditions, it is desirable to apply a braking force using the braking device(s)  20 . At least one controller or drive (not shown) is programmed to determine when such a condition exists in which it is desired to control the actuator  34  to apply each braking device  20  (i.e., “unsafe zones”). If such a condition exists, the controller(s) activate(s) the actuator(s)  34  for applying the braking force using the respective braking device(s)  20 . It should be readily appreciated how to configure or program the controller(s) and what type of software, hardware, firmware, or any combination of these best meet the needs of any particular situation. The controller(s) is/are programmed with a variety of conditions for selectively controlling the actuator(s)  34  for controlling the application of braking force(s) using the braking device(s)  20 . In an aspect, each individual controller can be configured to control the primary portion  16  (of the motor system) and actuator(s)  34  in a same general location of the hoistway  11 . 
     By way of example only and not by way of limitation, the actuator  34  can include a pair of coils that receive electrical power through a link between the controller and actuator  34 . The link allows the controller to selectively control application of the actuator  34  and includes a hard-wired connection to a source of power or wireless signal transmission between the controller and actuator  34 . A post can be normally biased away from the actuator  34  and toward the car  14  by a spring. When the coils are energized, the posts can be retracted in a direction toward the actuator  34 . In this retracted position, the braking device  20  avoids contact with the actuator  34 . A control algorithm identifies the “safe zones” into which the cars  14  can move and retracts the respective actuators  34  in such zones. The actuators  34  positioned in the “unsafe zones,” especially space defined by and between adjacent cars  14 , are extended to activate the respective braking devices  20  and prevent any contact between the cars  14 . 
     More specifically, in this example, in the event that the controller determines that it is desirable to control movement of a car  14  using the braking device(s)  20 , the controller controls deactivation of the coils to allow the springs to urge the stop members of the actuator(s)  34  into engagement with the braking device(s)  20 . By de-energizing the coils, the stop members are urged into engagement with the braking device(s)  20 . Any downward movement of the car  14  in this condition results in triggering of the braking device(s)  20  to engage the guiderail  12 . This results in applying a braking force that prevents further movement of the car  14 . 
     Once the controller determines that it is no longer desired to apply a braking force using the braking device(s)  20 , the controller appropriately controls the respective actuator(s)  34  (e.g., re-energizes the coils), and stop members are retracted away from the braking device(s)  20 . Upward movement of the car  14  releases the braking device(s)  20 . 
     Another example of an “unsafe zone” is at a landing during, for example, loading or unloading of a car  14  where the car  14  can move relatively slightly. The car  14  can be controlled by the assembly  28  in a manner that facilitates prevention of such movement. When the car  14  is stopped in a desired position at the landing, the controller controls each actuator  34  to apply the respective braking device  20 . In the event that the load on the car  14  changes significantly such that there would be a perceived bouncing of the car  14  relative to the landing, the braking device  20  operates to prevent such movement of the car  14  relative to the landing outside of a desired range. An acceptable range of movement of the car  14  can be set when the car  14  is otherwise stopped using a brake associated with the elevator system  10  as known. 
     It should be readily appreciated that it can be desired to control the actuator  34  in any suitable existing condition. It should also be readily appreciated that the controller can programmed to determine when the conditions exist in any suitable manner. It should also be readily appreciated that the link can include any suitable type of connection or transmission between the controller and actuator  34 . It should also be readily appreciated that the control algorithm can identify the “safe zones” and “unsafe zones” in any suitable manner. It should also be readily appreciated that the “safe zones” and “unsafe zones” can be defined in any suitable respective regions of the hoistway  11 . 
     The assembly  28  is useful for controlling movement of a car  14  and applying a braking force to prevent the “over-speed” condition or unexpected or undesired movement of the car  14 . The controller obtains information from known devices or techniques for determining when such a condition exists. It should be readily appreciated how to configure or program the controller for that purpose according to particular needs. 
     The assembly  28  locates the actuators  34  for the respective braking devices  20  in the hoistway  11  (not on the cars  14 ). Also, the system  10  eliminates communication between the cars  14  and respective drives and, thereby, makes the system  10  more robust and simple. Furthermore, the system  10  significantly reduces power requirements of the cars  14  and, thus, saves cost, weight, and life. In addition, the system  10  singularly and safely assures that the cars  14  neither contact each other nor have to take any action on their own for them to be stopped and held. 
     While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily appreciated 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 readily appreciated 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.