Patent Publication Number: US-2023136099-A1

Title: Elevator Door Roller and Track Replacement

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a divisional of U.S. patent application Ser. No. 16/943,530, filed on Jul. 30, 2020, the disclosure of which is hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to elevators, and to replacing the roller and track assemblies of sliding doors for elevator landings and elevator cars. 
     BACKGROUND 
     Elevator systems often use sliding doors to enclose an elevator hoistway and to enclose an elevator car. An illustration of sliding doors enclosing a hoistway is shown in  FIG.  1 A  from the perspective of looking at the hoistway from an elevator landing  10 . An illustration of sliding doors enclosing an elevator car is shown in  FIG.  1 B  from the perspective of inside the elevator car. An elevator car may stop at an elevator landing  10 , which may be one landing of many landings in a building, and at which people may enter and exit the elevator car. The landing  10  may be separated from the hoistway by two sliding doors  15 A and  15 B to guard against people or objects falling into the hoistway when the elevator car is not at the landing  10 . The doors  15 A and  15 B may respectively hang from roller pairs  20 A and  20 B which sit on a track  25 , with the roller pairs  20 A and  20 B and track  25  being positioned at a header  30  of the hoistway. Similarly, as shown in  FIG.  1 B , an elevator car  40  may be separated from the hoistway by two sliding doors  45 A and  45 B to guard against people or objects falling into the hoistway when the elevator car is not at the landing  10 . The doors  45 A and  45 B may respectively hang from roller pairs  50 A and  50 B which sit on a track  55 , with the roller pairs  50 A and  50 B and track  55  being positioned at a header  60  of the car  40 . Since the sliding door arrangements for the hoistway doors and the car doors are similar the hoistway doors and car doors and their respective parts will be referred to generically throughout this description, with the understanding that where no distinction is pointed out the description is intended to apply to both types of arrangements. 
     In many prior elevator door systems the rollers for each sliding door are secured to a respective door hanger which is an integral part of the door. Further, in many prior systems the track position is fixed by the header which is, in turn, an integral part of the landing in the case of hoistway doors and an integral part of the car in the case of car doors.  FIGS.  2 A to  2 C  illustrate an existing elevator door arrangement.  FIG.  2 A  shows a door arrangement  70  as viewed from a first side of a door  75 . The arrangement includes a door hanger  80 , a header  85 , and a track  90 .  FIG.  2 B  shows the door arrangement  70  of  FIG.  2 A  as viewed from a second side of the door  75  with the header  85  and track  90  hidden.  FIG.  2 C  is a side view of door arrangement  70  as viewed along direction D. As can be seen from  FIGS.  2 A to  2 C , the door hanger  80  is an integral part of door  75 , and the track  90  sits on a portion of the header  85 . The door hanger  80  has openings  80 A for respectively mounting rollers  95  which, in turn, ride on the track  90 . Also shown in the figures are support rollers  100  and safety retainers  105 . In the arrangement of  FIGS.  2 A to  2 C  the header  85  is integral with the landing for which the door is used or with the car for which the door is used. 
     SUMMARY 
     It has been recognized that the arrangement of prior elevator door systems makes the systems difficult to service and upgrade. For example, it has been recognized that replacing the rollers and track of prior elevator door systems often requires cutting the door hanger off the door, attaching a new hanger to the door, and removing the header and installing a new header. Such replacement is particularly burdensome in that cutting off the door header usually involves using a blowtorch and removing the header may compromise building structure around the header. Moreover, roller and track replacement is often required by a job specification. For instance, many job specifications require that aluminum rollers and plastic tracks of prior door arrangements be replaced with nylon rollers and steel tracks. 
     In view of the recognized difficulties with prior elevator door arrangements, the present technology is provided. The presently disclosed technology provides for less burdensome, lower cost replacement of elevator door rollers and tracks. 
     In accordance with an aspect of the present technology an elevator door subsystem includes a hanger mount having a first side, a second side, and an opening between the first side and second side, the first side having at least a portion configured for arrangement in an opening of an elevator door hanger, and the second side having at least a bearing surface; a leveling cam configured for sliding contact with the bearing surface and having a first surface, a second surface, an opening between the first surface and the second surface, and a third surface for contacting the bearing surface; an engaging member configured for placement in the opening of the hanger mount and the opening of the leveling cam; and a roller assembly for receiving the engaging member, such that when the roller assembly is positioned on one side of the elevator door hanger, the hanger mount is positioned within the opening of the elevator door hanger, and the leveling cam is positioned on another side of the elevator door hanger, the engaging member is receivable by the roller assembly after the engaging member is passed through the opening in the leveling cam, the opening in the hanger mount, and the opening in the door hanger. 
     In accordance with an aspect of the present technology, a method for replacing parts of an elevator door assembly includes removing rollers from an elevator door hanger of the door assembly; installing a hanger mount in an opening of the elevator door hanger, the hanger mount having a first side, a second side, and an opening between the first side and second side, the first side having at least a portion configured for arrangement in the opening of the elevator door hanger, and the second side having at least a bearing surface; positioning a roller assembly on one side of the elevator door hanger, the roller assembly being configured to receive an engaging member; positioning a leveling cam on another side of the elevator door hanger, the leveling cam configured for sliding contact with the bearing surface and having a first surface, a second surface, an opening between the first surface and the second surface, and a third surface for contacting the bearing surface; and inserting the engaging member through opening of the hanger mount and the opening of the leveling cam, and securing the engaging member within the roller assembly. 
     In accordance with an aspect of the present technology a kit for replacing parts of an elevator door assembly includes a hanger mount having a first side, a second side, and an opening between the first side and second side, the first side having at least a portion configured for arrangement in an opening of an elevator door hanger, and the second side having at least a bearing surface; a leveling cam configured for sliding contact with the bearing surface and having a first surface, a second surface, an opening between the first surface and the second surface, and a third surface for contacting the bearing surface; an engaging member configured for placement in the opening of the hanger mount and the opening of the leveling cam; and a roller assembly for receiving the engaging member, such that when the roller assembly is positioned on one side of the elevator door hanger, the hanger mount is positioned within the opening of the elevator door hanger, and the leveling cam is positioned on another side of the elevator door hanger, the engaging member is receivable by the roller assembly after the engaging member is passed through the opening in the leveling cam, the opening in the hanger mount, and the opening in the door hanger. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects, features and advantages of the present disclosure will be further appreciated when considered with reference to the following description of exemplary embodiments and accompanying drawings, wherein like reference numerals represent like elements. In describing the exemplary embodiments of the present disclosure illustrated in the drawings, specific terminology may be used for the sake of clarity. However, the aspects of the present disclosure are not intended to be limited to the specific terms used. 
         FIG.  1 A  is a perspective view of sliding doors enclosing an elevator hoistway as seen from the perspective of looking at the hoistway from an elevator landing. 
         FIG.  1 B  is a perspective view of sliding doors enclosing an elevator car from the perspective of inside the car. 
         FIGS.  2 A- 2 C  depict a prior elevator door arrangement. 
         FIG.  3 A  is an isometric partially-exploded view of an elevator door subsystem for one elevator door according to an embodiment. 
         FIG.  3 B  is an exploded perspective view of a portion of the subsystem shown in  FIG.  3 A  as seen from a first vantage point. 
         FIG.  3 C  is an exploded perspective view of the subsystem portion shown in  FIG.  3 B  as seen from a second vantage point different from the first vantage point. 
         FIG.  4    is an isometric partially-exploded view of two elevator door subsystems, and respective elevator doors, according to an embodiment. 
         FIG.  5 A  is a side view of a hanger mount according to an embodiment. 
         FIG.  5 B  is an isometric view of the hanger mount of  FIG.  5 A . 
         FIG.  5 C  shows a series of views of the hanger mount of  FIGS.  5 A and  5 B  showing one possible set of dimensions for the hanger mount. 
         FIG.  6    is an isometric view of a roller assembly, leveling cam, and bolt of an elevator door subsystem according to an embodiment. 
         FIGS.  7 A and  7 B  are a side view and a cross-section of a track according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  3 A  is an isometric partially-exploded view of an elevator door subsystem for one elevator door according to an embodiment. The subsystem of  FIG.  3 A  may be used when replacing the rollers of a prior elevator door. In the depicted embodiment, the subsystem is used for replacing the rollers of the door  75  of  FIGS.  2 A- 2 C . The subsystem includes two parts sets  200  and  205 , one for each of openings  80 A in door hanger  80 , although for purposes of brevity of description only set  205  will be described in detail, with any differences between the parts sets also being described. 
     Parts set  205  includes a roller assembly  210 , a cleaner-bracket assembly  215 , a hanger mount  220 , a leveling cam  225 , and an engaging member  230 . The roller assembly  210  is typically formed from a multiple of parts, although it may be a single part. The roller assembly  210  may be used to replace, for example, one of the rollers  95  of the  FIGS.  2 A- 2 C  arrangement, and may include a nylon roller. The cleaner-bracket assembly  215  acts to clean the roller assembly  210  by wiping debris off a roller of the roller assembly  210  as the roller rolls in its associated track (not shown). The roller assembly  210  and cleaner-bracket assembly  215  are secured to door hanger  80  by the hanger mount  220 , leveling cam  225 , and bolt  230 . The hanger mount  220  is shaped to fit into opening  80 A in door hanger  80  and includes an opening  220 A for allowing bolt  230  to pass through the hanger mount  220 . The leveling cam  225  also includes an opening, opening  225 A, for allowing bolt  230  to pass through the leveling cam  225 . The engaging member  230  may take the form of a bolt or screw, although in view of this description one will readily appreciate the wide range of alternative embodiments for the engaging member. For purposes of conciseness of description, the engaging member is depicted in this description as bolt  230  with the understanding that the engaging member is not limited to a bolt. 
     In the embodiment of  FIG.  3 A  the hanger mount  220  and leveling cam  225  are placed on one side of the door hanger  80  and the roller assembly  210  and cleaner-bracket assembly  215  are placed on the other side of the door hanger. A portion of the hanger mount  220 , in the form of two protrusions  220 B, is inserted into opening  80 A of the door hanger  80 . In the  FIG.  3 A  embodiment the protrusions  220 B are rectangular protrusions, although it should be noted that the protrusions may take other forms, such as semi-circular protrusions. In any event, leveling cam  225  is placed against the hanger mount and bolt  230  is passed through the opening  225 A in the leveling cam  225  and the opening  220 A in the hanger mount, and in such manner passes to the side of the door hanger  80  where roller assembly  210  and cleaner-bracket assembly  215  are positioned. Having been positioned through the leveling cam  225  and hanger mount  220 , the bolt  230  is received in an opening in the roller assembly  210 , which is in turn fit within an opening  215 A in the cleaner-bracket assembly  215 . In the embodiment of  FIG.  3 A  the opening in the roller assembly  210  is a blind hole and is not shown in the figure. In any event, the opening in the roller assembly  210  may be threaded to receive corresponding threads of bolt  230 . In such a case, when bolt  230  is tightened into the opening in the roller assembly  210  the leveling cam  225  is urged toward the door hanger  80  by the bolt  230  and against the hanger mount  220 . Further, when bolt  230  is tightened into the opening in the roller assembly  210  the cleaner-bracket assembly  215  is urged toward the door hanger  80  by the roller assembly  210  and against the hanger mount  220  and door hanger  80 . In this manner the roller assembly  210 , cleaner-bracket assembly  215 , hanger mount  220 , and leveling cam  225  are secured to the existing door hanger of  FIGS.  2 A- 2 C  by way of existing opening  80 A. 
       FIG.  3 B  is an exploded perspective view of the  FIG.  3 A  arrangement of the roller assembly  210 , cleaner-bracket assembly  215 , hanger mount  220 , leveling cam  225 , and bolt  230 . As can be seen from  FIG.  3 B , the roller assembly  210  may be formed of three parts, a roller  212 , a shaft  213 , and a retaining clip  214 . The roller  212 , e.g., a nylon roller, includes an opening  212 A for receiving the shaft  213 . The shaft  213  includes an opening  213 A, e.g., a blind-hole, for receiving bolt  230 . The retaining ring  214  couples to the shaft  213  so as to maintain the shaft in the opening  212 A while allowing the roller  212  to roll around the shaft  213 . 
     As can be further seen from  FIG.  3 B , the cleaner-bracket assembly  215  may include a cleaner  218  and a bracket  217 . The cleaner  218  may be compression fit within the bracket  217  to allow for easy replacement of the cleaner  218 , without necessitating removal or replacement of the bracket  217 . The bracket  217  includes the opening  215 A for accommodating a first protrusion  213 B of shaft  213 , and includes one or more secondary openings  215 B for accommodating one or more secondary protrusions  213 C of shaft  213 . Positioning the secondary protrusions  213 C into the secondary openings  215 B ensures that the shaft  213  will not rotate relative to the bracket  217 . 
       FIG.  3 C  is an exploded perspective view of the arrangement of  FIG.  3 B  as seen from a vantage point different from that of  FIG.  3 B . 
     It should be noted with respect to the embodiment of  FIGS.  3 A- 3 C  that the cleaner-bracket assembly  215  is typically formed from a multiple of parts, although it may be a single part. It should also be noted that the cleaner-bracket assembly  215  may include an integrated cleaner and oiler. Further, it should be noted that parts set  200  includes a cleaner-bracket assembly  230  that is different from cleaner-bracket assembly  215  in that cleaner-bracket assembly  230  is configured for use at one end of door hanger  80  while cleaner-bracket assembly  215  is configured for use at another end of door hanger  80  such that cleaner-bracket assembly  230  and cleaner-bracket assembly  215  may be said to mirror each other. 
     Other parts of the  FIG.  3 A  embodiment include a support roller  235 . The support roller  235  is provided to underlie the track (not shown) and guard against upward movements of the door  75  such that if the door is pushed in an upward direction (in direction A) the support roller  235  will be pushed against the underside of the track or track support (not shown) to prevent the roller assembly  210  from coming off of the track. The support roller  235  is mounted to the door hanger by bracket  237 , bolts  245 A and  245 B, nuts  250 A and  250 B, and washers  255 A and  255 B. As can be seen form the figure, the bracket  237  includes two openings  237 A and  237 B, with opening  237 B being sized to allow some pivotal movement of the bracket  237  about bolt  245 A when bolts  245 A and  245 B are partially tightened into nuts  250 A and  250 B. This allows for adjustment of the support roller  235  in an up-down direction. 
     In addition, the  FIG.  3 A  embodiment includes a retainer  240 . The retainer  240  is secured to the door hanger by a bolt  260 , nut  265 , and washer  270 . The retainer  240  provides backup support for the door  75  in the event the roller assembly  210 , or an associated element, fails. That is, in the event of a failure, the retainer  240  may bear on the track to support the door  75 . For example, if the roller  212  melts off in a fire, the retainer  240  maintains the general position of the door  75  by bearing on the track. 
     The parts sets  200  and  205  of  FIG.  3 A  may be provided together to efficiently supply elevator service personnel with all the parts needed to replace two roller assemblies of a prior elevator door arrangement as shown in  FIGS.  2 A- 2 C . Also, the two parts sets  200  and  205  may be provided with a track to replace track  90  of the  FIG.  2 A- 2 C  arrangement so that service personnel will have all the parts needed to replace the roller assemblies and track of the  FIGS.  2 A- 2 C  arrangement. In some embodiments the two parts sets  200  and  205  may each include a nylon roller and the sets may be provided together with a steel track. Additionally, the part sets  200  and  205  may be provided separate from each other and separate from the track. 
     Referring now to  FIG.  4   , there is shown an isometric partially-exploded view of two elevator door subsystems, and respective elevator doors, according to an embodiment. The two doors may act together to close off an elevator hoistway or elevator car. The arrangement shown in  FIG.  4    includes door  75  and parts sets  200  and  205  of  FIG.  3   , a second door  275 , and parts sets  300  and  305 . The second door  275  may be the same as door  75 . The parts set  300  may be the same as parts set  200 , and the parts set  305  may be the same as parts set  205 . In some embodiments, such as when cleaner-bracket assemblies are excluded from the parts sets  200 ,  205 ,  300 , and  305 , parts sets  200 ,  205 ,  300 , and  305  may be the same. Alternatively, one or more of parts sets  200 ,  205 ,  300 , and  305  may differ from one or more of the other parts sets of parts sets  200 ,  205 ,  300 , and  305 . Also, doors  75  and  275  may differ from each other. 
     The parts sets  200 ,  205 ,  300 , and  305  may be provided together to efficiently supply elevator service personnel with all the parts needed to replace roller assemblies for two doors of a prior elevator door arrangement. For example, the parts sets  200 ,  205 ,  300 , and  305  may be provided to replace roller assemblies for a two door arrangement in which each door is configured like the door shown in  FIGS.  2 A- 2 C . Also, the parts sets  200 ,  205 ,  300 , and  305  may be provided with one or more tracks to replace the corresponding track or tracks of the prior elevator door arrangement so that service personnel will have all the parts needed to replace the roller assemblies and track, or tracks, of a prior elevator door arrangement. For example, the parts sets  200 ,  205 ,  300 , and  305  and two tracks may be provided to replace roller assemblies and tracks for a two door arrangement in which each door and track is configured like the door and track shown in  FIGS.  2 A- 2 C . Nevertheless, it should be noted that the two elevator door arrangement of  FIG.  4    may be used with a single track on which the rollers of parts sets  200 ,  205 ,  300 , and  305  roll, rather than with two tracks, one for the rollers of parts sets  200  and  205  and one for the rollers of parts sets  300  and  305 . To address the one track case the parts sets  200 ,  205 ,  300 , and  305  may be provided together with a single track. In any event, the parts sets  200 ,  205 ,  300 , and  305  may each include a nylon roller and the sets may be provided together with one or more steel tracks. Additionally, the part sets  200 ,  205 ,  300 , and  305  may be provided separate from each other and separate from the track or tracks. 
     Referring now to  FIG.  5 A , there is shown a side view of hanger mount  220  according to an embodiment. As can be seen from the figure, the hanger mount  220  has a first side  400  that includes rectangular protrusions  220 B. The rectangular protrusions may be used for insertion into opening  80 A of the door hanger  80 . However, it should be noted that the present technology is not limited to a hanger mount having a first side with two rectangular protrusions. For example, the technology may employ a hanger mount having a single protrusion for insertion in the opening of a door hanger. 
       FIG.  5 B  is an isometric view of hanger mount  220 . As can be seen from  FIG.  5 B , the hanger mount  220  has a second side  405  that includes two bearing protrusions  410 . Each of the bearing protrusions  410  includes a bearing surface  415 . The bearing surface  415  of each protrusion  410  is configured for sliding contact with a surface of the leveling cam  225 . When the hanger mount  220  is positioned between the leveling cam  225  and roller assembly  210  by bolt  230 , as shown for example in  FIGS.  3 A- 3 C , rotating the leveling cam  225  about bolt  230  while maintaining contact between the leveling cam  225  and one of the bearing surfaces  415  results in movement of the roller assembly  210  and bolt  230  along direction A, or opposite direction A, relative to the hanger mount  220 , door hanger  80 , and door  75 . Thus, the bearing protrusions act in combination with the leveling cam  225  and bolt  230  to provide individual height adjustment of roller assemblies, such as roller assembly  210 , according to the needs of a service job. 
     It should be noted that while the embodiment of  FIG.  5 B  shows two bearing protrusions  410  and two bearing surfaces  415 , the present technology is not restricted to such configuration. For example, the technology may employ a hanger mount having a single protrusion with a single bearing surface. 
     Referring now to  FIG.  5 C , there is shown a series of views showing one possible set of dimensions for the hanger mount  220  of  FIGS.  5 A and  5 B . The dimensions are in inches. Among the dimensions for the hanger mount  220  are a first dimension  420  and a second dimension  425 . The first dimension  420  is larger than a diameter of the bolt  230  so that when the bolt  230  and leveling cam  225  are used to adjust the position of roller assembly  210  the bolt  230  is free to move along the direction corresponding to the first dimension. The second dimension  425  is smaller than a diameter of the leveling cam  225  so that the leveling cam can be placed against the hanger mount  220  without passing through opening  220 A of the hanger mount  220 . 
       FIG.  6    is an isometric view of roller assembly  210 , leveling cam  225 , and bolt  230  of an elevator door subsystem according to an embodiment. For instance, the elements of  FIG.  6    may be employed in the configuration of  FIGS.  3 A- 3 C . As can be seen from  FIG.  6   , the roller assembly  210  may have a track contacting portion  450  with a convex, or substantially convex, cross-section for placement on a track, the shape of the cross-section functioning to maintain alignment between the roller assembly  210  and the track. The leveling cam  225  may include a first surface  460 , a second surface  465 , and a third surface  470 . The first surface  460  may have a circular perimeter of a diameter that is greater than the second dimension  425  of the hanger mount  220 , and the second surface  465  may have a circular perimeter of a diameter which is the same as the diameter of the first surface  460 . The third surface  470  is configured for contacting bearing surfaces  415  of the hanger mount  220 . The opening  225 A of the leveling cam  225  may be circular and off-center with respect to the perimeter of the leveling cam  225  such that when the third surface  470  is in contact with a bearing surface  415  of the hanger mount  220 , and the leveling cam is rotated about the center of the opening  225 A, the center of the leveling cam  225  will move along a direction corresponding to the first dimension  420  of the hanger mount  220 . In addition, the leveling cam  225  includes a catch  475 , which may be in the form of an opening in the leveling cam  225 , a recess in the leveling cam  225 , or a projection on the leveling cam  225 . The catch  475  is provided for ease of rotating the leveling cam  225  about the center of opening  225 A. For example, the leveling cam  225  may be rotated using a screwdriver by placing the head of the screwdriver into the catch  475 . 
     Regarding the leveling cam  225 , it should be noted that it is not necessary for the first surface  460  or second surface  465  to have a circular perimeter. For example, the perimeter of the first surface  460  and second surface  465  may have an elliptical shape. 
     Regarding the hanger mount  220 , it should be noted that the hanger mount  220  is a multi-purpose component. In particular, the hanger mount  220  may be fit into the door hanger opening  80 A as shown in  FIGS.  3 A- 3 C , by facing the first side  400  of the hanger mount  220  to the door hanger  80  and inserting protrusions  220 B into the opening  80 A, or may be fit into an opening of a different type on a different door hanger by facing the second side  405  of the hanger mount  220  toward the different door hanger and inserting protrusions  410  into the different type of opening. In the case of inserting protrusions  410  into a door hanger opening, the protrusions  220 B may provide the bearing surfaces against which the leveling cam  225  may operate. In addition, it should be noted that the hanger mount  220  is not limited to the configuration depicted in the figures. The first side  400  may include a protrusion or protrusions other than rectangular protrusions  220 B, and the second side may include a protrusion or protrusions other than the semi-circular protrusions  410 . In any case, the protrusions included on a hanger mount of the present technology may be selected to fit into an opening on one or more types of vintage door hangers. 
     As further seen from  FIG.  6   , bolt  230  includes a threaded portion  480  and a flange  485 . The threaded portion has a circular diameter that is smaller, or substantially equal to, the diameter of the leveling cam opening  225 A so that the threaded portion  480  can pass through the opening  225 A and be received in a blind hole (not shown) in the roller assembly  210 , e.g., in opening  213 A of shaft  213  (see  FIG.  3 B ). The blind hole includes a threaded portion corresponding to the threaded portion  480  of the bolt  230  so that the bolt  230  can be secured to the roller assembly  210 . The flange  485  is configured for urging the leveling cam  225  against the hanger mount  220  when the threaded portion  480  of the bolt  230  is engaged with the threaded portion of the roller assembly  210 . 
     Referring now to  FIGS.  7 A and  7 B , there are shown a side view and cross-section of a track  500  according to an embodiment. Illustrative dimensions for the track are shown in the figures and are in units of inches. The track  500  may be used to replace, for example, the track  90  shown in  FIGS.  2 A and  2 C . Further, the track  500  may be made of steel. As can be seen from  FIG.  7 A , the track  500  includes two mounting holes  500 A and  500 B for accepting screws  505 A and  505 B which may be countersunk into the track  500  and used to mount the track  500  to a track support, such as an existing track support associated with header  85  of  FIG.  2 A . Notably, the track  500  is not limited to the two mounting holes  500 A and  500 B. In some embodiments more than two mounting holes may be provided. Moreover, in some embodiments a multiple of mounting holes may be provided such that subsets of the mounting holes correspond to respective types of track supports. 
       FIG.  7 B  is a cross-section of track  500  taken along axis AA′. As can be seen from  FIG.  7 B , the track  500  is shaped like an upside down “U” and has a roller contacting portion  510 . The roller contacting portion  510  has a concave, or substantially concave, cross-section to compliment the convex, or substantially convex, cross-section of track contacting portion  450  of the roller assembly  210 . 
     Embodiments of the present technology include, but are not restricted to, the following. 
     (1) An elevator door subsystem including a hanger mount having a first side, a second side, and an opening between the first side and second side, the first side having at least a portion configured for arrangement in an opening of an elevator door hanger, and the second side having at least a bearing surface; a leveling cam configured for sliding contact with the bearing surface and having a first surface, a second surface, an opening between the first surface and the second surface, and a third surface for contacting the bearing surface; an engaging member configured for placement in the opening of the hanger mount and the opening of the leveling cam; and a roller assembly for receiving the engaging member, such that when the roller assembly is positioned on one side of the elevator door hanger, the hanger mount is positioned within the opening of the elevator door hanger, and the leveling cam is positioned on another side of the elevator door hanger, the engaging member is receivable by the roller assembly after the engaging member is passed through the opening in the leveling cam, the opening in the hanger mount, and the opening in the door hanger.
 
(2) The elevator door subsystem of (1), wherein the system is operable such that when the roller assembly is positioned on one side of the elevator door hanger, the hanger mount is positioned within the opening of the elevator door hanger, the leveling cam is positioned on another side of the elevator door hanger, and the engaging member is received by the roller assembly after the engaging member is passed through the opening in the leveling cam, the opening in the hanger mount, and the opening in the door hanger, the position of the roller assembly is adjustable by rotating the leveling cam about the engaging member.
 
(3) The elevator door subsystem of (1), further including a track configured to receive a roller of the roller assembly so that the roller is operable to roll along the track.
 
(4) The elevator door subsystem of (3), wherein the track includes steel.
 
(5) The elevator door subsystem of (1), wherein the roller assembly includes a nylon roller.
 
(6) The elevator door subsystem of (1), further including a second hanger mount, a second leveling cam, a second engaging member and a second roller assembly.
 
(7) The elevator door subsystem of (6), further including a track configured to receive a roller of the roller assembly and a second roller of the second roller assembly so that the roller and the second roller are operable to roll along the track at the same time.
 
(8) The elevator door subsystem of (1), wherein the engaging member includes a bolt having a threaded portion and a flange, the threaded portion configured to be received by a corresponding threaded portion of the roller assembly, and the flange configured for urging the leveling cam against the hanger mount when the threaded portion of the bolt is engaged with the corresponding threaded portion of the roller assembly.
 
(9) The elevator door subsystem of (8), wherein the threaded portion of the roller assembly is included in a shaft of the roller assembly.
 
(10) The elevator door subsystem of (1), wherein the leveling cam includes a catch usable for rotating the leveling cam when the engaging member is positioned in the opening in the leveling cam.
 
(11) The elevator door subsystem of (1), further including a cleaner-bracket assembly configured for mounting on the elevator door hanger and cleaning a roller of the roller assembly.
 
(12) The elevator door subsystem of (1), further including a support roller configured for mounting on the elevator door hanger and maintaining a position of the elevator door hanger relative to a track that receives a roller of the roller assembly.
 
(13) A method for replacing parts of an elevator door assembly including removing rollers from an elevator door hanger of the door assembly; installing a hanger mount in an opening of the elevator door hanger, the hanger mount having a first side, a second side, and an opening between the first side and second side, the first side having at least a portion configured for arrangement in the opening of the elevator door hanger, and the second side having at least a bearing surface; positioning a roller assembly on one side of the elevator door hanger, the roller assembly being configured to receive an engaging member; positioning a leveling cam on another side of the elevator door hanger, the leveling cam configured for sliding contact with the bearing surface and having a first surface, a second surface, an opening between the first surface and the second surface, and a third surface for contacting the bearing surface; and inserting the engaging member through opening of the hanger mount and the opening of the leveling cam, and securing the engaging member within the roller assembly.
 
(14) The method of (13), further including adjusting a position of the roller assembly by rotating the leveling cam about the engaging member.
 
(15) The method of (13), further including providing a track configured to receive a roller of the roller assembly so that the roller is operable to roll along the track.
 
(16) The method of (15), wherein the track includes steel.
 
(17) The method of (13), wherein the roller assembly includes a nylon roller.
 
(18) The method of (13), further including mounting a cleaner-bracket assembly on the elevator door hanger such that a cleaner of the cleaner-bracket assembly acts to clean a roller of the roller assembly.
 
(19) The method of (13), further including mounting a support roller on the elevator door hanger such that the support roller maintains a position of the elevator door hanger relative to a track that receives a roller of the roller assembly.
 
(20) A kit for replacing parts of an elevator door assembly including a hanger mount having a first side, a second side, and an opening between the first side and second side, the first side having at least a portion configured for arrangement in an opening of an elevator door hanger, and the second side having at least a bearing surface; a leveling cam configured for sliding contact with the bearing surface and having a first surface, a second surface, an opening between the first surface and the second surface, and a third surface for contacting the bearing surface; an engaging member configured for placement in the opening of the hanger mount and the opening of the leveling cam; and a roller assembly for receiving the engaging member, such that when the roller assembly is positioned on one side of the elevator door hanger, the hanger mount is positioned within the opening of the elevator door hanger, and the leveling cam is positioned on another side of the elevator door hanger, the engaging member is receivable by the roller assembly after the engaging member is passed through the opening in the leveling cam, the opening in the hanger mount, and the opening in the door hanger.
 
     Most of the foregoing alternative examples are not mutually exclusive and may be implemented in various combinations to achieve unique advantages. As these and other variations and combinations of the features discussed above may be utilized without departing from the subject matter defined by the claims, the foregoing description of the embodiments should be taken by way of illustration rather than by way of limitation of the subject matter defined by the claims. As an example, the preceding operations do not have to be performed in the precise order described above. Rather, various steps can be handled in a different order, such as reversed, or simultaneously. Steps can also be omitted unless otherwise stated. In addition, the provision of the examples described herein, as well as clauses phrased as “such as,” “including” and the like, should not be interpreted as limiting the subject matter of the claims to the specific examples; rather, the examples are intended to illustrate only one of many possible embodiments. Further, the same reference numbers in different drawings may identify the same or similar elements. 
     Although the present disclosure herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present disclosure as defined by the appended claims.