Abstract:
A resurfacer for a belt of an elevator system includes a resurfacing roller having a selected surface roughness and a heater element to heat the belt to a selected temperature. A biasing element urges the resurfacing roller into contact with the belt and applies a selected pressure to the belt. A method for altering a surface roughness of a belt of an elevator system includes positioning a resurfacing roller having a selected surface roughness at an outer surface of the belt and heating the belt to a selected temperature. A selected pressure is applied to the belt via the resurfacing roller. The belt is passed along the resurfacing roller and the surface roughness of the belt is altered via the resurfacing roller.

Description:
BACKGROUND 
       [0001]    The subject matter disclosed herein relates to elevator systems suspended by belts. 
         [0002]    Elevator systems utilize belts, for example, coated steel belts, operably connected to an elevator car, and driven by a motor to propel the elevator car along a hoistway. Coated steel belts in particular include a plurality of wires located at least partially within a jacket material, for example a thermoplastic elastomer (TPE) material. The plurality of wires is often arranged into one or more strands and the strands are then arranged into one or more cords. In an exemplary belt construction, a plurality of cords is typically arranged equally spaced within a jacket in a widthwise direction. The motor drives a sheave, in this case a traction sheave, over which the belt is routed. The belt gains traction at the traction sheave, such that rotation of the traction sheave consequently drives movement of the elevator car. 
         [0003]    One of the characteristics of the jacket, which allows for smooth operation of the elevator system, and a desired amount of traction over the traction sheave is a surface roughness of the jacket material. Wear of the belt and jacket material over time alters the surface roughness of the jacket, smoothing the jacket surface, altering traction, noise and ride quality of the elevator system. 
       BRIEF DESCRIPTION 
       [0004]    In one embodiment, a resurfacer for a belt of an elevator system including a resurfacing roller having a selected surface roughness and a heater element to heat the belt to a selected temperature. A biasing element urges the resurfacing roller into contact with the belt and applies a selected pressure to the belt. Applying the resurfacing roller to the heated belt at the selected pressure alters a surface finish of the belt. 
         [0005]    Alternatively or additionally in this or other embodiments the resurfacer is fixed at a hoistway of the elevator system and the belt passes through the resurfacer. 
         [0006]    Alternatively or additionally in this or other embodiments, the heater element is one or more heater rods positioned at the resurfacing roller to heat the belt to the selected temperature. 
         [0007]    Alternatively or additionally in this or other embodiments, the selected temperature is in the range of 140 to 180 degrees Celsius. 
         [0008]    Alternatively or additionally in this or other embodiments, the selected pressure is in the range of 20 to 50 psi. 
         [0009]    Alternatively or additionally in this or other embodiments, the biasing member is a spring. 
         [0010]    Alternatively or additionally in this or other embodiments, the resurface includes at least two opposing resurfacing rollers. 
         [0011]    In another embodiment, an elevator system includes an elevator car, a motor, and a traction sheave operably connected to the motor to drive rotation of the traction sheave. A belt is operably connected to the elevator car. The belt is in frictional contact with the traction sheave such that rotation of the traction sheave urges movement of the elevator car. A resurfacer for the belt includes a resurfacing roller having a selected surface roughness, and a heater element to heat the belt to a selected temperature. A biasing element urges the resurfacing roller into contact with the belt and applies a selected pressure to the belt. Applying the resurfacing roller to the heated belt at the selected pressure alters a surface finish of the belt. 
         [0012]    Alternatively or additionally in this or other embodiments the resurfacer is fixed at a hoistway of the elevator system and the belt passes through the resurfacer. 
         [0013]    Alternatively or additionally in this or other embodiments, the heater element is one or more heater rods positioned at the resurfacing roller to heat the belt to the selected temperature. 
         [0014]    Alternatively or additionally in this or other embodiments, the selected temperature is in the range of 140 to 180 degrees Celsius. 
         [0015]    Alternatively or additionally in this or other embodiments, the selected pressure is in the range of 20 to 50 psi. 
         [0016]    Alternatively or additionally in this or other embodiments, the belt is coated with a thermoplastic elastomer. 
         [0017]    Alternatively or additionally in this or other embodiments, the resurfacer alters the surface roughness of the thermoplastic elastomer. 
         [0018]    In another embodiment, a method for altering a surface roughness of a belt of an elevator system includes positioning a resurfacing roller having a selected surface roughness at an outer surface of an elevator belt and heating the elevator belt to a selected temperature. A selected pressure is applied to the elevator belt via the resurfacing roller. The elevator belt is passed between the two or more resurfacing rollers and the surface roughness of the elevator belt is altered via the application of the heated resurfacing rollers to the elevator belt at the selected pressure. 
         [0019]    Alternatively or additionally in this or other embodiments, method is performed while the belt remains installed to the elevator system. 
         [0020]    Alternatively or additionally in this or other embodiments, a resultant surface roughness of the belt is equal to the surface roughness of the two or more resurfacing rollers. 
         [0021]    Alternatively or additionally in this or other embodiments, the belt is heated via one or more heater rods disposed at the resurfacing roller. 
         [0022]    Alternatively or additionally in this or other embodiments, the selected temperature is in the range of 140 to 180 degrees Celsius. 
         [0023]    Alternatively or additionally in this or other embodiments, the selected pressure is in the range of 20 to 50 psi. 
     
    
     
       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 cross-sectional view of an embodiment of an elevator belt; 
           [0028]      FIG. 3  is a cross-sectional view of an embodiment of a cord for an elevator belt; 
           [0029]      FIG. 4  is a cross-sectional view of an embodiment of a belt resurfacer for an elevator system; 
           [0030]      FIG. 5  is a schematic view of an embodiments of a belt resurfacer installed in a hoistway; and 
           [0031]      FIG. 6  is another cross-sectional view of an embodiment of a belt resurfacer for an elevator system. 
       
    
    
       [0032]    The detailed description explains the invention, together with advantages and features, by way of examples with reference to the drawings. 
       DETAILED DESCRIPTION 
       [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 deflector 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. It is to be appreciated that while the embodiments herein are described as applied to coated steel belts, it is to be appreciated that the disclosure herein may similarly be applied to steel ropes, either coated or uncoated. 
         [0034]    The deflector sheaves  18  each have a diameter  20 , which may be the same or different than the diameters of the other deflector sheaves  18  in the elevator system  10 . At least one of the sheaves could be a traction sheave  24 . The traction sheave  24  is driven by a machine  26 . Movement of the traction sheave  24  by the machine  26  drives, moves and/or propels (through traction) the one or more belts  16  that are routed around the traction sheave  24 . 
         [0035]    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 deflector 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 . 
         [0036]      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 deflector 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 deflector 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 cantilevered type elevator. The present invention could be used on elevator systems other than the exemplary types shown in  FIGS. 1A, 1B and 1C . 
         [0037]      FIG. 2  provides a schematic of a belt construction or design. Each belt  16  is constructed of a plurality of wires  28  (e.g. twisted into one or more strands  30  and/or cords  32  as shown in  FIG. 3 ) in a jacket  34 . As seen in  FIG. 2 , the belt  16  has an aspect ratio greater than one (i.e. belt width is greater than belt thickness). The belts  16  are constructed to have sufficient flexibility when passing over the one or more deflector 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  and counterweight  22 . The wires  28  may be steel, or formed from other metals or fibers. The jacket  34  could be any suitable material, including a single material, multiple materials, two or more layers using the same or dissimilar materials, and/or a film. In one arrangement, the jacket  34  could be a polymer, such as a thermoplastic elastomer, applied to the cords  32  using, for example, an extrusion or a mold wheel process. 
         [0038]    The jacket  34  can substantially retain the cords  32  therein. The phrase substantially retain means that the jacket  34  has sufficient engagement with the cords  32  to transfer torque from the machine  26  through the jacket  34  to the cords  32  to drive movement of the elevator car  12 . The jacket  34  could completely envelop the cords  32  (such as shown in  FIG. 2 ), substantially envelop the cords  24 , or at least partially envelop the cords  32 . 
         [0039]    Over time, by operation of the elevator system  10 , the jacket  34  wears, altering a surface roughness of an outer surface  36  of the jacket  34 . Altering of the surface roughness alters performance of the belt  16 , and affects operational characteristics of the elevator system  10  such as noise, vibration and ride quality. To restore an initial surface roughness of the outer surface  36 , a belt resurfacer  38 , such as that shown in  FIG. 4  is utilized. The belt resurfacer  38  includes a resurfacer housing  40  in which the other components of the resurfacer  38  are positioned. Two or more resurfacing rollers  42  are rotatably located in the housing  40 , with each resurfacing roller  42  rotatable about a respective roller axis  44 . The resurfacing rollers  42  are positioned on opposing sides  46   a  and  46   b  of the belt  16 , such that the belt  16  is positioned between two resurfacing rollers  42 . The resurfacing rollers  42  are formed from a metal or other heat-conductive material, and have a non-stick roller outer surface  48 . The roller outer surface  48  is formed to have a surface roughness substantially matching a selected surface roughness of the jacket  34  after refinishing. It is to be appreciated that while two resurfacing rollers are shown in the embodiment of  FIG. 4 , in other embodiments, the belt  16  may be positioned between one resurfacing roller  42  and another surface, for example a low friction plate or other surface. Such embodiments may be utilized for resurfacing on side of the belt  16  at a time, or in situations where resurfacing of only one side of the belt  16  is desired. 
         [0040]    To resurface the jacket  34 , the belt resurfacer  38  is positioned, as shown in  FIG. 5 , in the hoistway  14 , with the resurface rollers  42  positioned at the opposing sides  46   a  and  46   b  of the belt  16 . Referring again to  FIG. 4 , the resurfacing rollers  42  are biased toward the belt  16  by, for example, tensioning springs  60  to apply pressure on the belt  16 . In some embodiments, the applied pressure is in the range of  20  to  50  psi. While tension springs  60  are shown in  FIG. 4 , in other embodiments the pressure may be applied using a pneumatic cylinder, electromechanical actuator or other device. The resurfacing rollers  42  are heated to a temperature below the melting temperature of the jacket  34  material, but a temperature high enough to soften the jacket  34  material. In some embodiments, the resurfacing rollers  42  are heated to a temperature between 140 and 180 degrees Celsius. Alternatively, in other embodiments, the belt  16  may be heated separately from the rollers  42  or before encountering the rollers  42  by, for example, passing the belt  16  through a heater. It is to be appreciated that some jacket materials may require heating to temperatures outside of this exemplary range, depending on the speed at which the belt  16  is routed through the rollers  42  during resurfacing operations. At higher speeds, heating of the belt  16  to higher temperatures may be required to accomplish resurfacing. The resurfacing rollers  42  are heated to the selected temperature by one or more heater rods  50 , also known as cal rods, installed in the resurfacing rollers  42 . Alternatively a heating coil arrangement installed in the resurfacing rollers  42 , or other means, may be utilized to facilitate heating of the resurfacing rollers  42 . As shown in  FIG. 6 , the heater rods  50  are connected to a power source  52  that supplies electrical current to the heater rods  50 . A controller  54  connected to the power source  52  regulates the flow of electric current to the heater rods  50 , thus maintaining a selected temperature of the resurfacing rollers  42 . One or more temperature sensors (not shown) located at the resurfacing rollers  42  may provide temperature feedback to the controller  54 . 
         [0041]    The belt  16  is moved through the belt resurfacer  38 , such that the heated resurfacing rollers  42  soften the outer surface  36  and imprint the surface roughness from the resurfacing rollers  42  into the outer surface  36 , with aid from the pressure applied by the tensioning springs  60 . Once through the belt resurfacer  38 , the outer surface rehardens with the selected surface roughness matching that of the resurfacing rollers  42 . In some embodiments, the belt resurfacer  38  includes one or more guide rollers  56  to guide the belt  16  toward the resurfacing rollers  42 . 
         [0042]    The belt resurfacer  38  disclosed herein allows field repair of a worn belt  16  to improve traction and other operational characteristics of the belt  16  and the elevator system  10 . The device and method does not require unroping of the belt  16  from its installed position in the hoistway  14  for resurfacing and thus saves time and labor. Further, the device and method allows for service of a worn belt, thus avoiding premature replacement of the belt. 
         [0043]    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.