Patent Abstract:
A belt for suspending and/or driving an elevator car includes a plurality of tension elements extending along a length of the belt and a plurality of belt fibers transverse to the plurality of tension elements and interlaced therewith. The belt fibers define at least one traction surface of the belt. An edge fiber is located at a lateral end of the belt transverse to and secured to the plurality of belt fibers to secure the belt fibers in a selected position.

Full Description:
BACKGROUND OF THE INVENTION 
       [0001]    The subject matter disclosed herein relates to tension members such as those used in elevator systems 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. 
         [0003]    Still other systems utilize woven belts, in which yarns or other non-metallic fibers are woven together with the steel cords to retain the cords. The woven belt is also saturated or coated with an elastomeric binder. This is done to produce a selected amount of traction between the belt and a traction sheave that drives the belt, while reducing noise that sometimes results from the use of elastomeric belts. The steel cords in the woven belt are the primary load bearing tension members, the yarns and the binder material act to keep the cords in place and provide a traction surface. The use of yarn materials also expands the physical properties of the construction beyond what is possible from thermoplastic or extrudable rubber jacket materials. These properties include, but are not limited to, tensile strength, friction properties and flammability. In the woven belts, the yarns are oriented at angular orientations of 0 degrees and 90 degrees relative to the steel cords, and the belt is assembled by a weaving process on a loom. The weaving process is inefficient and time consuming. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0004]    In one embodiment, a belt for suspending and/or driving an elevator car includes a plurality of tension elements extending along a length of the belt and a plurality of belt fibers transverse to the plurality of tension elements and interlaced therewith. The belt fibers define at least one traction surface of the belt. An edge fiber is located at a lateral end of the belt and is secured to the plurality of belt fibers to secure the belt fibers in a selected position. 
         [0005]    Alternatively or additionally, in this or other embodiments, the edge fiber includes adhesive to secure the edge fiber to the plurality of belt fibers. 
         [0006]    Alternatively or additionally, in this or other embodiments, the edge fiber includes a thermally-activated material to secure the edge fiber to the plurality of belt fibers. 
         [0007]    Alternatively or additionally, in this or other embodiments, the edge fiber extends parallel to the plurality of tension elements. 
         [0008]    Alternatively or additionally, in this or other embodiments, the plurality of belt fibers is transverse to the plurality of tension elements at a non-perpendicular angle. 
         [0009]    Alternatively or additionally, in this or other embodiments, the angle is forty-five degrees. 
         [0010]    Alternatively or additionally, in this or other embodiments, the tension elements are formed from a first material and the belt fibers are formed from a second, different material. 
         [0011]    Alternatively or additionally, in this or other embodiments, the tension elements are formed from a metallic material and the belt fibers are formed from a non-metallic material. 
         [0012]    Alternatively or additionally, in this or other embodiments, the belt fibers comprise a thermoplastic material. 
         [0013]    Alternatively or additionally, in this or other embodiments, the belt fibers include thermoplastic filaments. 
         [0014]    Alternatively or additionally, in this or other embodiments, the belt fibers are at least partially coated with an elastomeric material. 
         [0015]    In another embodiment, a method of forming a belt for suspending and/or driving an elevator car includes arranging a plurality of tension elements along a length of the belt, defining a length of the belt and braiding a plurality of belt fibers together with the plurality of tension elements to form a braided structure. The plurality of belt fibers extends transverse to the plurality of tension elements. An edge fiber is braided into the plurality of belt fibers at a lateral side of the braided structure, and the edge fiber is secured to the plurality of belt fibers to retain the weave fibers in a selected position. 
         [0016]    Alternatively or additionally, in this or other embodiments, the edge fiber is heated to secure the edge fiber to the plurality of belt fibers. 
         [0017]    Alternatively or additionally, in this or other embodiments, an edge fiber is braided into the plurality of belt fibers at each lateral side of the braided structure. 
         [0018]    Alternatively or additionally, in this or other embodiments, the edge fiber extends parallel to the plurality of tension elements. 
         [0019]    Alternatively or additionally, in this or other embodiments, the plurality of belt fibers is transverse to the plurality of tension elements at a non-perpendicular angle. 
         [0020]    Alternatively or additionally, in this or other embodiments, the angle is forty-five degrees. 
         [0021]    Alternatively or additionally, in this or other embodiments, a band of selvage fibers are braided into the braided structure between adjacent tension elements of the plurality of tension elements. 
         [0022]    Alternatively or additionally, in this or other embodiments, the selvage fibers are secured to the plurality of belt fibers. 
         [0023]    Alternatively or additionally, in this or other embodiments, the braided structure is separated into two braided structures at the band of selvage fibers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1A  is a schematic of an exemplary elevator system having a 1:1 roping arrangement; 
           [0025]      FIG. 1B  is a schematic of another exemplary elevator system having a different roping arrangement; 
           [0026]      FIG. 1C  is a schematic of another exemplary elevator system having a cantilevered arrangement; 
           [0027]      FIG. 2  is a plane view of an embodiment of an elevator belt; 
           [0028]      FIG. 3  is a cross-sectional view of an embodiment of an elevator belt; 
           [0029]      FIG. 4  is a plane view of another embodiment of an elevator belt; 
           [0030]      FIG. 5  is a plane view of yet another embodiment of an elevator belt; 
           [0031]      FIG. 6  is a plane view of still another embodiment of an elevator belt; 
       
    
    
       [0032]    The detailed description explains the invention, together with advantages and features, by way of examples with reference to the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    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. 
         [0034]    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  52 . The traction sheave  52  is driven by a machine  50 . Movement of drive sheave by the machine  50  drives, moves and/or propels (through traction) the one or more belts  16  that are routed around the traction sheave  52 . 
         [0035]    At least one of the sheaves  18  could be a diverter, deflector or idler sheave. Diverter, deflector or idler sheaves are not driven by a machine  50 , but help guide the one or more belts  16  around the various components of the elevator system  10 . 
         [0036]    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  FIG. 1A, 1B or 1C ) or only one side of the one or more belts  16  engages the one or more sheaves  18 . 
         [0037]      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 . 
         [0038]    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 . 
         [0039]      FIG. 2  provides a schematic of an exemplary belt  16  construction or design. The belt  16  includes a plurality of tension elements  32 . As shown in  FIG. 3 , in some embodiments, the tension elements are cords formed from a plurality of steel wires  36 , which may be arranged into strands  38 . Referring again to  FIG. 2 , the tension elements  32  are arranged generally parallel to each other and extend in a longitudinal direction that establishes a length of the belt  16 . A plurality of belt fibers  40  that are braided together with the tension elements  32  into a fabric that substantially retains the tension elements  32  has a selected orientation relative to each other. The phrase “substantially retains” means that belt fibers  40  sufficiently engage the tension elements  32  such that the tension elements  32  to not pull out of, or move relative to, the belt fibers  40  in use of the belt  16 . 
         [0040]    Referring again to  FIG. 3 , the belt  16  includes a traction surface  42  on at least one side of the belt  16 , and is defined by the belt fibers  40 . Having the traction surface  42  defined by the belt fibers  40  includes the belt fibers  40  being exposed at the traction surface  42 , a coating over the belt fibers  40  having a surface contour defined by the presence of the belt fibers  40 , or a combination of these. 
         [0041]    The tension elements  32  are the primary load bearing structure of the elevator belt  16 . In some embodiments, the belt fibers  40  do not support the weight of the elevator car  12  or counterweight  22 . Nevertheless, the belt fibers  40  do form part of the load path. The belt fibers  40  transmit the traction forces between the traction sheave  52  and the belt  16  to the tension elements  32 . Such traction force transmission in some examples is direct (e.g. when the belt fibers  40  are exposed at the traction surface  42 ) or indirect (e.g. when the belt fibers  40  are coated and the coating establishes the exterior of the traction surface  42 ). 
         [0042]    The belt fibers  40  are arranged in a pattern relative to the tension elements  32  so that a spacing between the traction surface  42  and the tension elements  32  prevents the tension elements  32  from contacting a component that the traction surface  42  engages. For example, the tension elements  32  will not contact a surface on the traction sheave  52  as the belt  16  wraps at least partially around the traction sheave  52 . The size of the belt fibers  40 , the material of the belt fibers  40 , the pattern of the belt fibers  40  or a combination of these is selected to ensure the desired spacing between the tension elements  32  and the traction surface  42  so that the tension elements  32  are protected from direct engagement with a component such as the traction sheave  52 . In one embodiment, a coating over the belt fibers  40  protects the weave fibers  40  and therefore ensures that the tension elements  32  are sufficiently spaced from the traction surface  42  so that the tension elements  32  will not directly engage or come into contact with the traction sheave  52  or another sheave  18  of the elevator system. 
         [0043]    In an embodiment, the tension elements  32  are formed from a first material, such as drawn steel, and the belt fibers  40  are formed from a second, different material and have a much smaller thickness and/or cross-sectional dimension compared to the tension elements  32 . The belt fibers  40  may be formed from, for example, a nonmetallic material such as a polymer. In some embodiment, the belt fibers  40  include a thermoplastic material that is useful for establishing the traction surface  42 . One embodiment includes forming the belt fibers  40 , then coating the belt fibers  40  with the elastomeric material. In another embodiment, the belt fibers  40  are formed, braided to the tension elements  32 , then selectively coated with the elastomeric material. In still another embodiment, the belt fibers  40  are formed from a plurality of filaments, with at least one of the filaments including the thermoplastic material. 
         [0044]    The belt fibers  40  are oriented at a non-perpendicular angle to the tension elements  32 , for example, at +/−60 degrees or +/−45 degrees relative to the tension elements. Further, the belt fibers  40  may include first belt fibers  40   a  orientated at a first angle relative to the tension elements  32  and second belt fibers  40   b  oriented at a second angle relative to the tension elements  32 . Braiding with the belt fibers  40  oriented at angles other than 0 and 90 degrees relative to the tension elements  32  provides a tightening effect when as the belt  16  is formed, as well as when the belt  16  is initially put into service and a load is applied to it. The tightening improves dimensional stability of the belt  16  as well as greater control over traction of the belt  16  during operation. Thermoplastic, elastomeric, adhesive and/or thermally-activated materials may be included in the belt  16  to improve dimensional and physical properties of the belt  16 . 
         [0045]    Referring now to  FIG. 4 , in addition to the belt fibers  40  and the tension elements  32 , the belt  16  includes edge fibers  46  extending along the length of the belt  16  substantially parallel to the tension elements  32 . The edge fibers  46  may be formed from an adhesive or thermally-activated material, which when set, secures the positions of the belt fibers  40 , preventing the belt  16  from fraying or unraveling at the edges. In some embodiments, the edge fibers  46  may be mechanically closed around the belt fibers  40  by, for example, tying, to secure the edge fiber  46  and belt fiber  40  position. 
         [0046]    Referring now to  FIGS. 5 and 6 , the braiding arrangement of the belt fibers  40  allows for the simultaneous manufacturing of multiple belts  16 . Tension elements  32  for two or more belts  16  are arranged side-by-side, along with edge fibers  46  at the edges, and a band of selvage fibers  48 , or alternatively, additional edge fibers  46  between adjacent tension elements  32 . The belt fibers  40   a  and  40   b  are braided through the edge fibers  46 , tension elements  32  and selvage fibers  48  defining a single braided structure. The edge fibers  46  and selvage fibers  48 , if needed, are activated by, for example, application of heat, to secure the belt fibers  40   a  and  40   b  in place. Finally, the braided structure is separated into two or more belts  16 , as shown in  FIG. 6 , by cutting or otherwise separating the structure between the selvage fibers  48 . Manufacturing of more than one belt  16  at a time utilizing this method increases efficiency of fabrication and reduces material waste in fabrication. While the embodiment illustrated produces two belts  16  simultaneously, one skilled in the art will recognize that such method may be used to fabricate 3, 4 or more belts  16  simultaneously. 
         [0047]    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.

Technology Classification (CPC): 3