Patent Publication Number: US-11040858-B2

Title: Elevator door interlock assembly

Description:
BACKGROUND 
     Elevator systems are in widespread use for carrying passengers between various levels in buildings, for example. Access to an elevator car requires that elevator car doors open when the car is at a landing at which a passenger desires to board the elevator car, for example. Each landing includes hoistway doors that move with the elevator car doors between open and closed positions. 
     There are various known coupler and interlock arrangements for coupling the elevator car doors to the hoistway doors so that the door mover that causes movement of the car doors also causes desired movement of the hoistway doors. Most door couplers include a set of vanes supported on the elevator car door structure. Most interlocks include at least one roller supported on the hoistway door structure. When the roller is received adjacent the vanes, it is possible to move both doors together. The movement of the car doors includes one of the vanes pushing on the roller to unlock the hoistway door and move it to open it with the elevator car door. This movement imposes a load on the latch of the interlock. In some cases, the same roller bears load associated with moving the hoistway door in the other direction. 
     It is believed that elevator door system components account for approximately 50% of elevator maintenance requests and 30% of callbacks. Almost half of the callbacks due to a door system malfunction are related to one of the interlock functions. One contributing factor to such issues is the wear and tear on the interlock latch and its associated components resulting from bearing the load associated with moving the hoistway door. 
     Another drawback associated with known interlock arrangements is that the process of installing the interlocks along the hoistway is time-consuming and undesirably complicated. Each interlock has to be positioned to receive the coupler vanes as the elevator car approaches the corresponding landing. Inaccurate interlock placement may result in undesired contact between the coupler vanes and the interlock as the elevator car passes the landing, for example. Additionally, adjusting the rollers to achieve the necessary alignment with the coupler requires adjusting the position of the corresponding hoistway door lock and switch to ensure that the interlock properly cooperates with the lock. If the lock and switch components are not accurately positioned, the elevator may not perform reliably as indications from the switches along the hoistway are needed to ensure that all hoistway doors are closed before the elevator car moves along the hoistway. 
     SUMMARY 
     An illustrative example elevator door interlock includes a latch situated for pivotal movement about a pivot axis between a door locking position and a released position. At least one coupling bumper situated for movement with the latch between the door locking and released positions. The coupling bumper is selectively movable relative to the pivot axis into an alignment position where the coupling bumper is positioned to cooperate with a door coupler. At least one stationary support is situated to contact the coupling bumper when the latch is in the released position where the stationary support bears a load associated with moving an associated door. 
     An example embodiment having one or more features of the elevator door interlock of the previous paragraph includes a first base. The at least one coupling bumper is supported on the first base and the first base is selectively movable relative to the pivot axis. 
     In an example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs, the first base is selectively pivotally movable about the pivot axis. 
     An example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs includes at least one fastener. The first base comprises a plate including at least one slot, the at least one fastener is at least partially received the at least one slot, and the at least one fastener selectively secures the first base in a selected position relative to the latch. 
     In an example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs, the first base is selectively linearly movable relative to the pivot axis. 
     An example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs includes a second base. The at least one stationary support is supported on the second base and the second base is selectively moveable relative to the pivot axis. 
     In an example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs, the second base is selectively pivotally moveable about the pivot axis. 
     An example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs includes at least one fastener. The second base includes at least one slot, the at least one fastener is at least partially received through the slot, and the at least one fastener selectively secures the second base and the stationary support in a fixed position relative to the pivot axis. 
     An example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs includes a bracket, the bracket is selectively moveable relative to the latch, the coupling bumper is supported on the bracket, and the bracket is selectively secured to the latch to fix a position of the coupling bumper relative to the latch. 
     In an example embodiment having one or more features of the elevator door interlock of any of the previous paragraphs, the at least one coupling bumper comprises a roller and the stationary support comprises a roller. 
     An illustrative example method of installing an elevator door interlock includes positioning the latch in a selected position relative to a hoistway door component, adjusting a position of the at least one coupling bumper relative to the latch by moving a base supporting the at least one coupling bumper relative to the hoistway door component without moving the pivot axis of the latch, and securing the base in a selected position that secures at least the first one of the bumpers in a desired position relative to the hoistway door component when the latch is in a locking position. 
     In an example embodiment having one or more features of the method of the previous paragraphs, the elevator door interlock includes at least one stationary support and the method comprises adjusting a position of the stationary support relative to the pivot axis by moving a second base supporting the at least one stationary support relative to the hoistway door component, and securing the second base in a selected position that secures the at least one stationary support in a position to contact the at least one coupling bumper when the latch is in a released position. 
     In an example embodiment having one or more features of the method of any of the previous paragraphs, the at least one stationary support bears a load associated with moving an associated hoistway door. 
     In an example embodiment having one or more features of the method of any of the previous paragraphs, moving the base comprises pivoting the base about the pivot axis. 
     In an example embodiment having one or more features of the method of any of the previous paragraphs, moving the base comprises moving the base linearly relative to the pivot axis. 
     In an example embodiment having one or more features of the method of any of the previous paragraphs, the elevator door interlock includes a switch that indicates when the latch is in a locked position and the method comprises establishing a position of the switch relative to the pivot axis of the latch before adjusting the position of the at least one coupling bumper. 
     The various features and advantages of an example embodiment will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates selected portions of an elevator system including a door interlock designed according to an embodiment of this invention. 
         FIG. 2  is schematically shows an example elevator door interlock designed according to an embodiment of this invention with a latch in a locked position. 
         FIG. 3  shows the example interlock of  FIG. 2  with the latch in a released position. 
         FIG. 4  shows another example elevator door interlock designed according to an embodiment of this invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of this invention provide an elevator door interlock that is easily adjustable for properly aligning the interlock with an elevator door coupler. The alignment can be achieved without requiring any adjustment of relative positions of the latch and lock switch components. Embodiments of this invention also avoid requiring a roller used to unlock the door lock to bear or carry a load associated with opening the hoistway door. 
       FIG. 1  schematically illustrates selected portions of an elevator system  20 . An elevator car  22  includes car doors  24  that are situated adjacent hoistway landing doors  26  when the elevator car  22  is parked at a landing. At least one portion or component of a door coupler  28  associated with the elevator car doors  24  cooperates with an interlock  30  associated with the hoistway doors  26  so that the elevator car doors  24  and the hoistway doors  26  move together between opened and closed positions. 
       FIGS. 2 and 3  show the interlock  30  of an example embodiment. The interlock  30  includes a latch  32  that is moveable between a locking position (shown in  FIG. 2 ) and a released position (shown in  FIG. 3 ). A locking surface  34  on the latch  32  engages a stop  36  on a door lock  38  when the latch  32  is in the locking position. In the released position shown in  FIG. 3 , the locking surface  34  is clear of the stop  36  and the door  26  is free to move with the elevator car door  24 . 
     The lock  38  includes a switch  40  that cooperates with a switch contact  42  supported on the latch  32  to provide an indication when the associated hoistway door  26  is closed and locked in a known manner. As the latch  32  rotates or pivots about a pivot axis  44 , the switch contact  42  moves away from the switch  40  resulting in an indication from the switch  40  that the door  26  is unlocked. 
     As shown in  FIG. 3 , the door coupler  28  includes vanes that cooperate with at least one coupling bumper  50  to move the latch  32  from the locking position (of  FIG. 2 ) into the released position. In the illustrated example, the door coupler  28  includes vanes that are received on opposite sides of the coupling bumper  50 . Other coupler arrangements are used in other embodiments. As the coupler bumper  50  moves to the right (according to the drawings) the latch  32  rotates pivots about the pivot axis  44  until the coupling bumper contacts a stationary support  52 . The coupling bumper  50  and the stationary support  52  comprise rollers in this example. 
     The coupling bumper  50  is supported on a first base  54  that is secured to the latch  32  by at least one fastener  56 . A slot  58  allows for selective pivotal movement of the first base  54  about the pivot axis  44  to adjust a position of the coupling bumper  50  relative to the pivot axis and a door component  59 , such as a door hanger associated with the hoistway door  26 . Once the desired position of the coupling bumper  50  relative to the door coupler  28  is achieved, tightening the fastener  56  secures the first base  54  in the desired position relative to the latch  32 . 
     The mass of the first base  54  also serves as a counterweight that biases the latch  32  into the locking position. 
     One feature of the example embodiment is that the pivot axis  44  of the latch  32  remains stationary relative to the door component  59  during the adjustment of the position of the coupling bumper  50 . This allows for the coupling bumper  50  to be selectively aligned with the door coupler  28  without altering the relative alignment of the latch  32 , lock  38 , switch  40  and switch contact  42 . Keeping all of those components in preselected position relative to the pivot axis  44  or the door component  59  avoids any potential misalignment of those components and reduces the complexity of and time required for aligning all interlocks  30  along a hoistway. 
     Once the coupling bumper  50  position is set, the stationary support  52  can be selectively positioned to achieve appropriate alignment with the door coupler  28  and a desired relationship between the position of the coupling bumper  50  and the stationary support  52 . In this example embodiment, the stationary support  52  is supported on a second base  60  that is selectively moveable relative to the pivot axis  44 . Fasteners  62  are at least partially received through slots  64  in the second base  60 . When the fasteners  62  are loose enough the second base can be pivoted about the pivot axis  44  to adjust the position of the stationary support  52 . Once the desired position is achieved, the fasteners  62  secure the second base in the desired position relative to the door component  59 . 
     The stationary support  52  is situated to contact the coupling bumper  50  as the door coupler  28  causes movement of the coupling member to the right (according to the drawings) when the latch  32  is in a fully released position. The stationary support  52  serves the purpose of limiting an amount of latch movement and carrying loads associated with movement of the associated hoistway door  26 . As the door coupler  28  causes continued movement to the right (according to the drawings) the door  26  moves in an opening direction. The load associated with moving the door  26  is born or carried by the stationary support  52  and transferred through the second base  60  to the door component  59 . When the door coupler  28  moves the door  26  in an opposite direction to close the door (to the left in the drawings), the stationary support  52  is directly engaged by a vane of the coupler  28 . 
     The example configuration of the coupling bumper  50  and stationary support  52  removes any strain on the latch  32  and its associated components as the coupling bumper  50  does not carry any of the load associated with moving the door  26 . Reducing any such load on the coupling bumper  50  and the latch  32  increases the reliability and service life of the interlock  30 . 
       FIG. 4  illustrates another example embodiment in which the first base  54 ′ is linearly moveable relative to the pivot axis  44 . In this example two fasteners  56  and slots  54 ′ allow for selectively moving the base  54 ′ and the coupling bumper  50  relative to the pivot axis to achieve alignment between the coupling bumper  50  and the door coupler  28  so that the interlock  30  works as intended. 
     Having the ability to adjust the position of the coupling bumper  50  and stationary support  52  without having to move any of the latch  32 , pivot axis  44  or switch  40  allows for aligning interlocks  30  along an entire hoistway with the door coupler  28  of the elevator car  22  in a more efficient and economical manner There is no need to adjust the latch  32  or switch contact  42  relative to the lock  38  and switch  40 , for example. There is no risk of a misalignment between the switch  40  and switch contact  42 . This feature of the illustrated examples enhances the reliability of proper operation of the elevator system and reduces the amount of labor required to achieve proper alignment between the door coupler  28  and the interlocks  30  along the hoistway. 
     Additionally, the illustrated example embodiments allow for the position of the pivot axis  44 , the lock  38 , the switch  40 , and the switch contact  42  to all be pre-established in a controlled manufacturing setting. The interlock  30  may be installed as a preassembled unit onto a door component  59 , such as a door hanger, which further reduces labor, time and cost and further enhances the accuracy of the relative positions of the components of the interlock  30 . This type of arrangement leads to a more reliable interlock system and elevator system operation. 
     Interlocks designed according to an embodiment of this invention facilitate reducing callbacks that are otherwise associated with problems or malfunctions caused by interlock misalignment or wear and tear on the latch and associated components of an interlock. Embodiments of this invention provide cost savings not only during installation or maintenance procedures, but also by reducing the need for maintenance or adjustment during the service life of the associated elevator system. 
     Different embodiments are shown and described but their respective features are not limited to just those embodiments. For example, at least one of the components of one embodiment may be used in place of a corresponding component of another embodiment. Additional embodiments can be realized by combining various features of the disclosed examples. 
     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.