Patent Publication Number: US-11383958-B2

Title: Elevator compensation rope guard

Description:
BACKGROUND 
     Elevator systems are useful for carrying passengers and items between different levels of a building. Many elevator systems are traction-based and include traction ropes that suspends the elevator car and a counterweight. A machine causes movement of a traction sheave that, in turn, causes movement of the traction ropes for moving the elevator car as desired. One feature of traction-based elevator systems is a compensation assembly including compensation rope suspended beneath the car and counterweight and a tie down mechanism near the bottom of the hoistway. The compensation assembly facilitates maintaining appropriate tension on the traction ropes to achieve desired traction. 
     Some elevator systems are susceptible to rope sway. For example, in high rise buildings that may experience building sway, the hoist ropes and compensation ropes may sway laterally at high amplitudes. Compensation tie down sheaves typically include grooves that constrain the compensation ropes, however, under certain conditions such sway may result in one or several of the compensation ropes jumping out of or leaving its groove. A jumped compensation rope can become entangled with other compensation ropes during elevator car movement, which requires service by maintenance personnel. 
     SUMMARY 
     An illustrative example embodiment of an elevator compensation assembly includes at least one compensation sheave having an outer surface configured to engage a plurality of compensation rope members. A guard has an inner surface situated adjacent the outer surface of the compensation sheave. A plurality of dividers that extend away from at least one of the outer surface of the compensation sheave or the inner surface of the guard. The dividers establish a space between adjacent ones of the dividers for accommodating a compensation rope member. 
     In an example embodiment having at least one feature of the elevator compensation assembly of the previous paragraph, the dividers each comprise a flange on the outer surface of the at least one compensation sheave. 
     In an example embodiment having at least one feature of the elevator compensation assembly of any of the previous paragraphs, the dividers each comprise a rib on the inner surface of the guard. 
     In an example embodiment having at least one feature of the elevator compensation assembly of any of the previous paragraphs, the dividers each comprise a groove on the inner surface of the guard. 
     An example embodiment having at least one feature of the elevator compensation assembly of any of the previous paragraphs includes a plurality of compensation rope members received on the outer surface of the compensation sheave and the flanges extend from the outer surface of the compensation sheave a distance corresponding to at least one-half a thickness of the compensation rope members. 
     In an example embodiment having at least one feature of the elevator compensation assembly of any of the previous paragraphs, the dividers each comprise a rib on the inner surface of the guard. 
     In an example embodiment having at least one feature of the elevator compensation assembly of any of the previous paragraphs, the dividers each comprise a groove on the inner surface of the guard. 
     An illustrative example embodiment of an elevator system includes the compensation assembly of any of the previous paragraphs, an elevator car, a counterweight, and a plurality of compensation rope members coupled to the elevator car and the counterweight, the plurality of compensation rope members being respectively received in the spaces between the adjacent ones of the dividers. 
     In an embodiment having at least one feature of the system of the previous paragraph, the compensation sheave includes a plurality of grooves on an exterior of the compensation sheave and the compensation rope members are respectively received in the grooves. 
     An illustrative example embodiment of a method of controlling a position of elevator compensation rope members includes placing a compensation rope member within each of the spaces of the elevator compensation assembly of any of the previous paragraphs. 
     The various features and advantages of at least one disclosed 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. 
         FIG. 2  is a cross-sectional illustration taken along the lines  2 - 2  in  FIG. 1  showing selected portions of an example elevator compensation assembly. 
         FIG. 3  is an enlarged view of the portion of  FIG. 2  encircled at 3 schematically illustrating that portion of the example compensation rope guard configuration. 
         FIG. 4  schematically illustrates another example compensation rope guard configuration. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically illustrates selected portions of an elevator system  20 . An elevator car  22  is coupled to a counterweight  24  by traction ropes  26 . Although not shown in detail, the traction ropes  26  include a plurality of tension members, such as round ropes or flat belts. The traction ropes  26  follows a path defined, at least in part, by sheaves  30  and  32 . The sheave  30  is a traction sheave associated with a machine  34  that selectively causes movement of the traction ropes  26  to control the movement and position of the elevator car  22  for providing elevator service to passengers. 
     The elevator system  20  includes a compensation assembly  40  that facilitates maintaining adequate tension on the traction ropes  26  to achieve desired traction under a variety of elevator system conditions. The compensation assembly  40  include compensation rope members  42  suspended beneath the elevator car  22  and counterweight  24 . The compensation rope members  42  follow a path defined, at least in part, by compensation sheaves  44 , which are supported as part of a tie down mechanism  46 . Guards  50  are situated to keep the compensation rope members  42  in position on the compensation sheaves  44 . 
       FIGS. 2 and 3  schematically illustrate selected portions of the example compensation assembly  40 . In this example, the plurality of compensation rope members  42  are individual round ropes but other embodiments include chains or belts, for example. Each of the compensation rope members  42  is received within a corresponding groove  54  on each of the compensation sheaves  44 . The predetermined position of each compensation rope  42  in this example embodiment includes the portion of the compensation rope  42  wrapped about each compensation sheave  44  being properly received within the corresponding one of the grooves  54 . 
     The compensation sheaves  44  each include a plurality of flanges  56  adjacent the grooves  54 . The flanges  56  are sheave dividers that divide the exterior of the compensation sheave  44  into a plurality of compensation rope member receiving spaces. The flanges  56  are distinct from the grooves  54  in that the compensation rope members  42  engage the grooves  54  but do not contact the flanges  56  under normal or expected elevator system operating conditions. 
     The flanges  56  provide a surface on each side of each of the compensation rope members  42  that extends radially away from an outer surface of the compensation sheave  44  to at least partially establish a containment space for each of the compensation rope members  42 . In the illustrated example configuration, an outer edge of the flanges  56  is spaced from a center of the compensation sheave  44  further than a center of the roping member  42  is spaced from the center of the compensation sheave  44 . In the illustrated example embodiment, the flanges  56  extend from the outer surface of the compensation sheave  44  along a radially oriented distance that is approximately equal to one half a thickness of the compensation rope members  42 . 
     The guard  50  comprises a metal bracket or plate that remains stationary relative to the compensation sheave  44 . The guard  50  includes a plurality of dividers  58  aligned with the flanges  56 . Spacing between the outermost edges of the flanges  56  and the most interior edge of the dividers  58  allows for rotation of the compensation sheave  44  without any contact between the compensation sheave  44  and the guard  50 . 
     The dividers  58  separate respective spaces for each of the compensation rope members  42 . The dividers  58  and the flanges  56  cooperate to form a space within which the respective compensation rope member  42  is kept. The flanges  56  and the dividers  58  effectively separate the compensation rope members  42  and prevent unwanted contact or entanglement between them even under significant rope sway conditions within the elevator system  20 . 
     In the example of  FIG. 3 , the dividers  58  comprises ribs or projections on the interior of the guard  50 . The dividers may be formed together with the body or plate of the guard  50  or may be separate pieces that are secured in place onto the body of the guard  50 . 
       FIG. 4  shows another configuration of the guard  50 . In this example, the interior surface of the guard  50  includes a groove  60  facing each of the grooves  54  on the compensation sheave  44 . The groove  60  accommodates movement of the compensation rope member  42  out of the groove  54  and, together with the dividers or flanges  56 , serves to prevent any contact between the compensation rope member  42  and an adjacent one of the compensation rope members. 
     The dividers or flanges  56  and the dividers  58  or grooves  60  establish a containment space that constrains undesired movement of a compensation rope member relative to the compensation sheave  44 . 
     While separate dividers  56 ,  58  are provided on the compensation sheaves  44  and the guards  50 , respectively in the example embodiments, others include dividers on only the sheaves  44  and still others include divider on only the guards  50 . One benefit of including dividers on both the sheaves  44  and the guards  50  is that the dividers are not as long and, therefore, more structurally stable to resist deformation that might otherwise result from contact with an undesirably moving compensation rope member  42 . 
     The illustrated and described example embodiments provide protection against compensation rope members  42  becoming entangled with each other by preventing the compensation rope members  42  from coming out of a corresponding groove  54  on a compensation sheave  44  and contacting another one of the compensation rope members  42 . The illustrated example embodiments minimize or eliminate potential complications that may otherwise occur as a result of such compensation rope sway or other movement out of a predetermined position for the compensation rope members  42 . 
     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.