Abstract:
A termination assembly ( 28 ) for an elevator belt ( 16 ) includes a termination body ( 40 ) and a fixed wedge ( 48 ) secured to the termination body ( 40 ) and having a plurality of fixed wedge surfaces ( 52 ). A moving wedge ( 56 ) is located in the termination body ( 40 ) and has a plurality of moving wedge surfaces ( 60 ) interactive with the fixed wedge surfaces ( 52 ). When an elevator belt ( 16 ) is inserted into the termination body ( 40 ) between the moving wedge ( 56 ) and the termination body ( 40 ) and a tension load is applied to the elevator belt ( 16 ), the moving wedge surfaces ( 60 ) are urged to move relative to the fixed wedge surfaces ( 52 ) to apply a contact pressure to the elevator belt ( 16 ) thus retaining the elevator belt ( 16 ) at the termination body ( 40 ).

Description:
BACKGROUND 
       [0001]    The subject matter disclosed herein relates to elevator systems having tension members for suspension and/or driving of the elevator car and/or counterweight. 
         [0002]    Conventional elevator systems use rope formed from steel wires as a lifting tension load bearing member. Other systems utilize a lifting belt formed from a number of steel cords, formed from steel wires, retained in an elastomeric jacket. The cords act as the load supporting tension member, while the elastomeric jacket holds the cords in a stable position relative to each other, and provides a frictional load path to provide traction for driving the belt. For ultra-high rise applications, forming the cords from a carbon fiber material is considered advantageous because of considerable weight savings to the belt over the increased length of the belt. 
         [0003]    In a typical steel cord belt system, termination devices are utilized at ends of the belt, often at the car or counterweight, or in the hoistway, to retain ends of the belt. These termination devices require bending of the belt to engage the belt into the termination device, with the bend radius often being about 12 millimeters or less. Use of such a termination with carbon fiber cord belts requires bending of the carbon fiber cords to tight radii such as those above and results in cracking and/or breakage of the carbon fiber material, thereby weakening the belt. Further, the carbon fiber members have a relatively low compressive strength, so that clamping pressure on the belt at the termination must be low enough to prevent crushing the carbon fibers. 
       BRIEF SUMMARY 
       [0004]    In one embodiment, a termination assembly for an elevator belt includes a termination body and a fixed wedge secured to the termination body and having a plurality of fixed wedge surfaces. A moving wedge is located in the termination body and has a plurality of moving wedge surfaces interactive with the fixed wedge surfaces. When an elevator belt is inserted into the termination body between the moving wedge and the termination body and a tension load is applied to the elevator belt, the moving wedge surfaces are urged to move relative to the fixed wedge surfaces to apply a contact pressure to the elevator belt thus retaining the elevator belt at the termination body. 
         [0005]    Additionally or alternatively, in this or other embodiments a bearing assembly is located between and interactive with the plurality of moving wedge surfaces and the plurality of fixed wedge surfaces. 
         [0006]    Additionally or alternatively, in this or other embodiments the bearing assembly includes a plurality of roller elements retained in a roller cage. 
         [0007]    Additionally or alternatively, in this or other embodiments the termination body is a tubular member. 
         [0008]    Additionally or alternatively, in this or other embodiments the fixed wedge surfaces are nonparallel to a rear face of the fixed wedge, the rear face being furthest from the moving wedge. 
         [0009]    Additionally or alternatively, in this or other embodiments the moving wedge surfaces are parallel to the fixed wedge surfaces. 
         [0010]    Additionally or alternatively, in this or other embodiments the plurality of moving wedge surfaces is three moving wedge surfaces and the plurality of fixed wedge surfaces in three fixed wedge surfaces. 
         [0011]    In another embodiment, an elevator system includes an elevator car suspended in a hoistway via an elevator belt. A termination assembly secures the elevator belt at an end of the elevator belt. The termination assembly includes a termination body and a fixed wedge secured to the termination body and having a plurality of fixed wedge surfaces. A moving wedge is located in the termination body and has a plurality of moving wedge surfaces interactive with the fixed wedge surfaces. When the elevator belt is inserted into the termination body between the moving wedge and the termination body and a tension load is applied to the elevator belt, the moving wedge surfaces are urged to move relative to the fixed wedge surfaces to apply a contact pressure to the elevator belt thus retaining the elevator belt at the termination body. 
         [0012]    Additionally or alternatively, in this or other embodiments a bearing assembly is positioned disposed between and interactive with the plurality of moving wedge surfaces and the plurality of fixed wedge surfaces. 
         [0013]    Additionally or alternatively, in this or other embodiments the bearing assembly includes a plurality of roller elements retained in a roller cage. 
         [0014]    Additionally or alternatively, in this or other embodiments the termination body is a tubular member. 
         [0015]    Additionally or alternatively, in this or other embodiments the fixed wedge surfaces are nonparallel to a rear face of the fixed wedge, the rear face being furthest from the moving wedge. 
         [0016]    Additionally or alternatively, in this or other embodiments the moving wedge surfaces are parallel to the fixed wedge surfaces. 
         [0017]    Additionally or alternatively, in this or other embodiments the plurality of moving wedge surfaces is three moving wedge surfaces and the plurality of fixed wedge surfaces in three fixed wedge surfaces. 
         [0018]    Additionally or alternatively, in this or other embodiments the termination is located at the elevator car. 
         [0019]    Additionally or alternatively, in this or other embodiments the elevator belt is in an unbent orientation in the termination body. 
         [0020]    Additionally or alternatively, in this or other embodiments tension members of the belt are formed at least partially from a carbon fiber material. 
         [0021]    In yet another embodiment, a method of terminating an elevator belt includes urging a belt end through a termination body of a termination assembly in a first direction, between the termination body and a moving wedge. The belt is urged in a second direction opposite the first direction, thereby urging movement of the moving wedge relative to a fixed wedge. The moving wedge has a plurality of moving wedge surfaces interactive with a plurality of fixed wedge surfaces of the fixed wedge. The moving wedge is urged into contact with the elevator belt via the interaction between the moving wedge and the fixed wedge, thus applying a contact pressure to the elevator belt to retain the elevator belt at the termination body. 
         [0022]    Additionally or alternatively, in this or other embodiments a compressive force is transmitted from the fixed wedge to the moving wedge via a bearing assembly disposed between the fixed wedge and the moving wedge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1A  is a schematic of an exemplary elevator system having a 1:1 roping arrangement; 
           [0024]      FIG. 1B  is a schematic of another exemplary elevator system having a different roping arrangement; 
           [0025]      FIG. 1C  is a schematic of another exemplary elevator system having a cantilevered arrangement; 
           [0026]      FIG. 2  is a cross-sectional view of an embodiment of an elevator belt; and 
           [0027]      FIG. 3  is a cross-sectional view of an embodiment of a termination assembly for an elevator belt. 
       
    
    
       [0028]    The detailed description explains the invention, together with advantages and features, by way of examples with reference to the drawings. 
       DETAILED DESCRIPTION 
       [0029]    Shown in  FIGS. 1A, 1B and 1C  are schematics of exemplary traction elevator systems  10 . Features of the elevator system  10  that are not required for an understanding of the present invention (such as the guide rails, safeties, etc.) are not discussed herein. The elevator system  10  includes an elevator car  12  operatively suspended or supported in a hoistway  14  with one or more belts  16 . The one or more belts  16  interact with one or more sheaves  18  to be routed around various components of the elevator system  10 . The one or more belts  16  could also be connected to a counterweight  22 , which is used to help balance the elevator system  10  and reduce the difference in belt tension on both sides of the traction sheave during operation. The belts  16  are retained at belt ends  24 ,  26  via a termination mechanism  28 , described in more detail below. 
         [0030]    The sheaves  18  each have a diameter  20 , which may be the same or different than the diameters of the other sheaves  18  in the elevator system  10 . At least one of the sheaves could be a traction sheave  30 . The traction sheave  30  is driven by a machine  32 . Movement of drive sheave by the machine  32  drives, moves and/or propels (through traction) the one or more belts  16  that are routed around the traction sheave  30 . 
         [0031]    At least one of the sheaves  18  could be a diverter, deflector or idler sheave. Diverter, deflector or idler sheaves are not driven by the machine  32 , but help guide the one or more belts  16  around the various components of the elevator system  10 . 
         [0032]    In some embodiments, the elevator system  10  could use two or more belts  16  for suspending and/or driving the elevator car  12 . In addition, the elevator system  10  could have various configurations such that either both sides of the one or more belts  16  engage the one or more sheaves  18  (such as shown in the exemplary elevator systems in  FIGS. 1A, 1B or 1C ) or only one side of the one or more belts  16  engages the one or more sheaves  18 . 
         [0033]      FIG. 1A  provides a 1:1 roping arrangement in which the one or more belts  16  terminate at the car  12  and counterweight  22 .  FIGS. 1B and 1C  provide different roping arrangements. Specifically,  FIGS. 1B and 1C  show that the car  12  and/or the counterweight  22  can have one or more sheaves  18  thereon engaging the one or more belts  16  and the one or more belts  16  can terminate elsewhere, typically at a structure within the hoistway  14  (such as for a machineroomless elevator system) or within the machine room (for elevator systems utilizing a machine room. The number of sheaves  18  used in the arrangement determines the specific roping ratio (e.g. the 2:1 roping ratio shown in  FIGS. 1B and 1C  or a different ratio).  FIG. 1C  also provides a so-called rucksack or cantilevered type elevator. The present invention could also be used on elevator systems other than the exemplary types shown in  FIGS. 1A, 1B and 1C . Further, while embodiments discussed are related to belts  16  for hoisting or suspending the elevator car  12  (hoist belts), one skilled in the art will readily appreciate that the present disclosure may be readily applied to compensation belts of elevator systems, used to steady or balance elevator systems, especially in high-rise applications. 
         [0034]    The belts  16  are constructed to have sufficient flexibility when passing over the one or more sheaves  18  to provide low bending stresses, meet belt life requirements and have smooth operation, while being sufficiently strong to be capable of meeting strength requirements for suspending and/or driving the elevator car  12 .  FIG. 2  provides a schematic of an exemplary belt  16  construction or design. The belt  16  includes a plurality of tension elements  34  extending longitudinally along the belt  16 . The tension elements  34  are arranged generally parallel to each other and extend in a longitudinal direction that establishes a length of the belt  16 . In exemplary embodiments, the tension elements  34  are arranged into cords  36 , and at least partially retained in a jacket  38  formed from, for example, an elastomeric material. In exemplary embodiments, the tension elements  34  are formed from a carbon fiber material. It is to be appreciated, however, that other embodiments of tension members  34  may be formed from additional or other materials, such as steel or combinations of steel and carbon fiber. 
         [0035]    The belts  16  are retained at belt ends  24 ,  26  via a termination mechanism  28 , an embodiment of which is shown in  FIG. 3 . The termination  28  is fixed to, for example, the elevator car  12  or other structure of the elevator system  10 , such as the counterweight  22 , traction sheave  30  or hoistway  14  wall. The termination  28  includes a termination body  40  which in some embodiments is tubular and may have a rectangular cross-section with open ends  42  and  44 . The belt  16  passes through the termination body  40  via the open ends  42  and  44  and is retained at the termination  28  via a Z-wedge clamping assembly  46 . The clamping assembly  46  includes a fixed wedge  48  having a rear face  50  fixed to the termination body  40  via, for example, bolts, pins, welding, or the like. A fixed z-wedge face  52  of the fixed wedge  48  is located opposite to the rear face  50  and includes two or more fixed wedge segments  54  positioned nonparallel to the rear face  50 . A movable wedge  56  is positioned in the termination body  40  between the belt  16  and the fixed wedge  48 . The movable wedge  56  has a movable rear face  58  with a high coefficient of friction to engage the belt  16 , and has a plurality of movable wedge segments  60  opposite the movable rear face  58 . To provide the high friction required to engage the belt  16 , the rear face  58  may have surface coatings or treatments or patterns, such as, for example, a raised diamond pattern or a knurled pattern. The movable wedge segments  60  are configured and arranged to be parallel to the fixed wedge segments  54 . In some embodiments, the wedges  48  and  56  are metallic and formed from, for example, sintered metal, steel or cast aluminum. 
         [0036]    A bearing assembly  62  is located between the fixed wedge segments  54  and the movable wedge segments  60 , and includes a flat roller cage  64  including a plurality of roller elements  66  at each fixed wedge segment  54 /movable wedge segment  60  to control movement of the movable wedge  56  relative to the fixed wedge  48 . The roller cages  64  may be fixed to, for example, the fixed wedge  48  or the termination body  40  to maintain the roller cage  64  position in the termination body  40 . The roller cage  64  provides a low friction surface for movement of the movable wedge  56  relative to the fixed wedge  48 , but such lower friction may be provided in other ways in other embodiments. In some embodiments the roller cage  64  may be replaced with a low friction surface on one or both of the movable wedge segments  60  or the fixed wedge segments  64  of, for example, Teflon or UHMW (Ultra high molecular weight polyethylene). 
         [0037]    In operation, the belt  16  is loaded into the termination  28  through the termination body  40 , opposite a clamping direction  68  and located between the termination body  40  and the movable rear face  58  of the movable wedge  56 . The belt  16  is then pulled in the clamping direction  68 , for example, downwardly in  FIG. 3 . As the belt  16  is pulled in the clamping direction  68 , the belt  16  engages the movable rear face  58 , moving the movable wedge  56  in the clamping direction  68 . Due to the orientation of the movable wedge segments  60  and the fixed wedge segments  54 , this movement has the effect of urging the movable wedge  56  toward the belt  16  and exerting a clamping pressure, together with the termination body  40 , on the belt  16 . The clamping pressure retains the belt  16  at the termination  28 . 
         [0038]    To prevent crushing of the carbon fibers due to the contact pressure, multiple fixed wedge segments  54  and moving wedge segments  60  are utilized as shown in  FIG. 3 . Depending on the maximum allowable pressure on the carbon fibers and jacket material, the number of z wedge sections and wedge angle can be varied in order to achieve an optimal result with regard to the specific carbon fiber belt characteristics. Additionally, in some embodiments, the termination includes a transitional entry radius at a point where the belt  16  enters the termination in order to provide a gradual change in pressure and so as to not pinch the belt  16  with a sudden step transition as it enters the termination. Further, the termination retains the belt  16  without bending, thus preventing cracking and/or breaking. Also, the belt  16  may be assembled into the termination  28  without the use of tools, as it merely requires insertion of the belt  16  into the termination  28 , then pulling on the belt  16  to engage the locking feature. 
         [0039]    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 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.