Abstract:
A method of making a guide rail for an elevator system method comprising the steps of: providing a guide rail; applying a protective layer to the guide rail for corrosion protection; and removing at least a portion of the protective layer. A sheet metal guide rail for an elevator system comprises a base portion; and a blade portion extending from the base portion. The blade portion includes: a first section for engaging a guiding device and/or a safety of the elevator system; and a second section for engaging a guiding device and/or a safety of the elevator system. The second section contacts the first section. The sheet metal guide rail could be made using the aforementioned method.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention generally relates to guide rails. More specifically, this invention relates to guide rails for an elevator system. 
         [0002]    Elevator systems typically include a set of guide rails for guiding an elevator car as it moves vertically within a hoistway. Typical guide rails have a generally T-shaped cross-section with a base portion that is secured to a hoistway wall using conventional brackets. A blade portion extending away from the base portion provides guiding surfaces along which guide rollers or slides travel during movement of the elevator car. The blade portion of the guide rail additionally provides a surface that the elevator safeties engage during an overspeed condition. Because of these functions, the blade portion of a guide rail must have suitable surface characteristics. Conventional guide rails are made from steel, and the surfaces must be protected from corrosion during storage and shipment as well as during use in the hoistway. The base portion of a guide rail is typically painted to prevent corrosion. The blade portion, however, is not painted in order to prevent the paint from affecting the operation of the elevator safeties that must act on the blade portion. 
         [0003]    Nevertheless, the blade portion of the guide rails should be protected from corrosion during shipment and storage before the time of installation. One conventional method includes applying an anti-corrosion coating, such as wax, to the blade portion. An exemplary wax-base anti-corrosion coating is TECTYL 506 available from The Valvoline Company of Lexington, Kentucky (a division of Ashland, Inc. of Covington, Ky.). The application process may not ensure a consistent application of the coating. In addition, no consistent and/or efficient cleaning process exists to remove the coating and to ensure a suitable surface for the safety to engage. The labor and expense involved with removing the coating introduces additional cost and time required for installation of an elevator system. In addition, the coating must unfortunately be removed at the installation site using a chemical solvent. This technique generates waste, such as rags soaked with solvent, that requires disposal. 
       SUMMARY OF THE INVENTION 
       [0004]    According to one aspect of the present invention, a method of making a guide rail for an elevator system method comprises the steps of: providing a guide rail; applying a protective layer to the guide rail for corrosion protection; and removing at least a portion of the protective layer. 
         [0005]    Alternatively, in this or other aspects of the invention, the guide rail providing step could include the steps of: providing a sheet of metal; and forming the sheet into the guide rail. 
         [0006]    Alternatively, in this or other aspects of the invention, the applying step could occur before the forming step. 
         [0007]    Alternatively, in this or other aspects of the invention, the forming step could include creating at least one bend in the sheet, and the method could further comprise the step of applying sealant to the bend. 
         [0008]    Alternatively, in this or other aspects of the invention, the removing step could comprise peeling at least a portion of the protective layer from the guide rail. 
         [0009]    Alternatively, in this or other aspects of the invention, the removing step does not use a solvent. 
         [0010]    Alternatively, in this or other aspects of the invention, the applying step could comprise applying a first protective layer and a second protective layer, and the removing step could remove at least a portion of the first protective layer. 
         [0011]    Alternatively, in this or other aspects of the invention, the protective layer could be a plastic sheet. 
         [0012]    Alternatively, in this or other aspects of the invention, the plastic sheet could include an adhesive backing. 
         [0013]    Alternatively, in this or other aspects of the invention, the protective layer could be a coating comprising silicone, acrylic, polyurethane and/or polysulfide. 
         [0014]    Alternatively, in this or other aspects of the invention, the method could further comprise the step of cutting the protective layer. 
         [0015]    Alternatively, in this or other aspects of the invention, the cutting step could comprise perforating the protective layer. 
         [0016]    According to another aspect of the present invention, a sheet metal guide rail for an elevator system comprises a base portion; and a blade portion extending from the base portion. The blade portion includes: a first section for engaging a guiding device and/or a safety of the elevator system; and a second section for engaging a guiding device and/or a safety of the elevator system. The second section contacts the first section. 
         [0017]    Alternatively, in this or other aspects of the invention, the guide rail could include a bend between the first section and the second section. 
         [0018]    Alternatively, in this or other aspects of the invention, the guide rail could include a first angled section and a second angled section located between the base portion and the blade portion and angled relative to the base portion and the blade portion. 
         [0019]    Alternatively, in this or other aspects of the invention, the base portion could further comprise at least one flange. 
         [0020]    Alternatively, in this or other aspects of the invention, the flange could comprise: a first flange section; a second flange section; and a bend between the first flange section and the second flange section. 
         [0021]    Alternatively, in this or other aspects of the invention, the second flange section could contact the first flange section. 
         [0022]    According to another aspect of the present invention, the aforementioned guide rail (or any of its alternatives) could be made according to the aforementioned method (or any of its alternatives). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  schematically illustrates selected portions of an elevator system. 
           [0024]      FIG. 2  is a perspective view of a conventional T-shaped guide rail. 
           [0025]      FIG. 3A  is a plan view of a piece of sheet metal prior to being formed into an elevator guide rail with one possible arrangement of a protective layer of the present invention. 
           [0026]      FIG. 3B  is a plan view of a piece of sheet metal prior to being formed into an elevator guide rail with another possible arrangement of a protective layer of the present invention. 
           [0027]      FIG. 3C  is a plan view of a piece of sheet metal prior to being formed into an elevator guide rail with another possible arrangement of protective layer of the present invention. 
           [0028]      FIG. 4A  is a plan view of the sheet metal of  FIG. 3A  formed into one possible arrangement of a guide rail of the present invention. 
           [0029]      FIG. 4B  is a plan view of the guide rail of  FIG. 4A  with a section of the protective layer subsequently removed. 
           [0030]      FIG. 5A  is a plan view of the sheet metal of  FIG. 3B  or  FIG. 3C  formed into one possible arrangement of a guide rail of the present invention. 
           [0031]      FIG. 5B  is a plan view of the guide rail of  FIG. 5A  with a section of the protective layer subsequently removed. 
           [0032]      FIG. 6A  is a plan view of a conventional guide rail with one possible arrangement of a protective layer of the present invention. 
           [0033]      FIG. 6B  is a plan view of the guide rail of  FIG. 6A  with a section of the protective layer subsequently removed. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]      FIG. 1  schematically shows selected portions of an elevator system  20 . Components of the elevator system that are not relevant to the present invention (e.g. ropes/belts, governor assembly, etc.) are not discussed. An elevator car  22  can travel along one or more guide rails  24  through the operation of one or more guiding devices  26  mounted to the car  22 . Examples of said guiding devices  26  include roller guides or sliding guide shoes that engage the guide rails  24  in a known manner. 
         [0035]    In some arrangements, although not shown in the figures, the elevator system could include a counterweight that can also travel along one or more guide rails through the operation of one or more guiding devices. The counterweight guide rails could also benefit from the present invention. 
         [0036]      FIG. 2  provides a conventional guide rail. The guide rail  24  includes a blade portion  28  and a base portion  30 . The base portion  30  facilitates mounting the guide rail  24  within a hoistway, for example using known brackets. The blade portion  28  extends from the base portion  30  and engages the guiding devices  26  during movement of the elevator car  22 . In this illustrated example, the blade portion  28  has multiple guiding surfaces  42  along which the guiding devices  26  travel. At least one of the guiding surfaces  42  also serves as a braking surface for elevator safeties (not shown) to engage. As is known, elevator safeties engage the guide rail  24  during certain events, such as an over speed condition. 
         [0037]    The engagement of a safety on the guide rail  24  creates a significant bending moment on the guide rail  24 . Guide rails  24  are conventionally made from cold-rolled steel to achieve the stiffness necessary to withstand such bending moment. 
         [0038]    The present invention could be used on conventional guide rails  24  or guide rails  24  made from sheet metal.  FIGS. 3A ,  3 B and  3 C display a flat piece of sheet metal  70  prior to being formed or bent into guide rail  24 . One or more surfaces of the sheet metal  70  could be covered with a protective layer. 
         [0039]    The sheet metal  70  of  FIG. 3A  includes a top surface  72 , bottom surface  74 , left side surface  76  and/or right side surface  78 . Some or all of the surfaces  72 ,  74 ,  76 ,  78  could receive a protective layer  50 . As an example, all four surfaces  72 ,  74 ,  76 ,  78  of the sheet metal  70  could receive the protective layer  50 . As another example, only the surface(s) that will be engaged by the safety could receive the protective layer  50  (e.g. top surface  72 ). As yet another example, only the surface(s) that will not be engaged by the safety could receive the protective layer  50  (e.g. bottom surface  74 , left side surface  76  and/or right side surface  78 ). As yet another example, and as specifically shown in  FIG. 3A , just the major surfaces of the sheet metal  70  could receive the protective layer  50  (e.g. top surface  72  and bottom surface  74 ) and not the minor surfaces (e.g. left side surface  76  and right side surface  78 ). 
         [0040]    The protective layer  50  may be applied to the desired surface(s) of the guide rail  24  at any suitable step in the process. In an exemplary guide rail  24  formed of sheet metal  70 , the protective layer  50  may be applied at any suitable step between (and including) the initial forming of the sheet metal  70  (e.g. the sheet metal manufacturer performs the application) and the use of the guide rail  24  by an elevator system in a hoistway (e.g. the installer of the guide rails  24  performs the application). As a specific example, the protective layer  50  could be applied to the sheet metal  70  before forming/bending the sheet metal  70  into a guide rail  24 . The application of the protective layer  50  to the sheet metal  70  could be a manual process, automated process or a semi-automated process. 
         [0041]    As an example, the protective layer  50  could be made of one or more plastic materials (in one or more layers), such as polyethylene, formed into a sheet. The protective layer  50  may include corrosion inhibitors such as hexamine, benzotriazolel, phenylenediamine, dimethylethanolamine, polyaniline, nitrate, or nitrite. 
         [0042]    The sheet could also have an adhesive backing. As an example, the adhesive backing suitably retains the protective layer  50  to the guide rail  24  (e.g. during transport, installation and use) but allows for removal of the protective layer  50  (or portions thereof) including the adhesive backing when desired. In this arrangement, the protective layer becomes a removable layer  50 . An exemplary product to be used as removable layer  50  is 30L60 Medium Tack Protection Film available from Presto Tape, Inc. of Bensalem, Pennsylvania. 
         [0043]    Rather than the aforementioned sheet, the protective layer  50  could be a protective coating  50  applied to the guide rail  24  (or, with sheet metal guide rails, the sheet metal  70 ). Such coatings could be, for example, a liquid coating applied by a suitable method such as spraying, dipping, brushing and/or pouring and allowed to cure or dry. Exemplary protective coatings  50  include silicone, acrylic, polyurethane, or polysulfide. 
         [0044]    Although various exemplary materials have been provided, those skilled in the art and those with the benefit of this description will be able to select appropriate material(s) for the protective layer  50  to meet the needs of a particular situation. 
         [0045]      FIGS. 3B and 3C  provide two alternative arrangements of the protective layer. Other embodiments are also possible. In  FIG. 3B , the protective layer  50  covers a desired portion of the sheet metal  70  and a second protective layer  51  covers a different portion of the sheet metal  70 . As an example, the protective layers  50 ,  51  could, combined, cover all or just a portion of the sheet metal  70 . The protective layer  51  could be different than the protective layer  50 , for example using the conventional materials mentioned above like paint or wax base anti-corrosion materials, or having a stronger adhesive backing (so the protective layer  51  is not a readily removable/peelable). 
         [0046]    In  FIG. 3C , the second protective layer  51  covers the protective layer  50 . In essence, the protective layer  50  acts as a mask during the application of the protective layer  51 . As discussed with the prior alternative arrangement, protective layers  50 ,  51  combined could cover all, or just a portion, of the sheet metal  70 . The protective layer  51  could be different than the protective layer  50 , for example using the conventional materials mentioned above like paint or wax base anticorrosion materials. 
         [0047]      FIGS. 4A-5B  provide an exemplary guide rail  24  of the present invention that could be made from the sheet metal  70  provided in  FIGS. 3A-3C . The guide rail  24  shown in  FIGS. 4A-5B  is generally Y-shaped, with blade portion  28  and base portion  30 . Each end of the base portion  30  can include a flange  32  for example to provide additional stiffness to the rail. The flange  32  can extend at an angle, such as about 90°, from the base portion  30 . The flange  32  can be formed by a bend  34 , such as about a 180° bend, in the sheet metal  70 . In this arrangement, the bend  34  can produce two flange sections  32   a,    32   b  that can be generally parallel (and generally contacting). 
         [0048]    The base portion  30  can include two angled sections  36  that transition from the base portion  30  to the blade portion  28 . The angled sections  36  extend at an angle, such as about 60°, from the base portion  30 . The angled sections  36  can provide additional stiffness to the guide rail  24 . 
         [0049]    The blade portion  28  can include a bend  40 , such as about a 180° bend, in the sheet metal  70 . The bend  40  can produce has two generally parallel (and generally contacting) sections  42  of the sheet metal  70 . The bend  40 , as seen in the figures, can be at the nose (or tip) of the guide rail  24 . One or both of the sections  42  are engaged by the elevator safety (these sections may also be engaged by the guiding device  26 ). The bend  40  provides additional stiffness to the guide rail  24  to withstand the braking forces caused by the elevator safety. The sections  42  of the sheet metal  70  also provide additional stiffness to the guide rail  24  since these sections  42  contact each other for a length of the blade portion  28  (e.g. between bend  40  and angled sections  36 ), in essence creating blade portion  28  that is twice as thick as base portion  30 . 
         [0050]    The use of the protective layer(s) on the guide rail  24  shown in  FIGS. 4A-5B  can help maintain the desired thickness of the blade portion  28  by preventing corrosion. Corrosion, including crevice corrosion (e.g. the crevices formed by the bends  34 ,  40 ), could alter (usually increase) the thickness of the blade portion  28  and impact system performance. Thus, as an example, the protective layer  50  (FIGS.  4 A/ 4 B) or the protective layers  50 ,  51  (FIGS.  5 A/ 5 B) could be applied to those sections of the sheet metal  70  where crevice corrosion could occur, such as sections of the bottom surface  74  of sheet metal  70  at the bends  34 ,  40  and the areas adjacent these bends (i.e. the length where the sheet metal  70  contacts itself) such as in the flanges  32  and blade portion  28 . Other sections and other surfaces could also receive the protective layer. 
         [0051]    Alternatively or in addition to the protective layer(s), a sealant (not shown) could be used to protect against crevice corrosion. Exemplary sealants include silicone, acrylic, polyurethane, or polysulfide. 
         [0052]    Despite its benefits, proper operation of the elevator safety demands that some of the area on one or both of the sections  42  that are engaged by the elevator safety must not have any protective layer. One possible way to ensure the area of one or both of the sections  42  do not have any protective layer is to never adding a protective layer to those areas. 
         [0053]    An alternative manner of ensuring the area of one or both of the sections  42  do not have the protective layer during use of the elevator system is to remove the protective layer from those areas before using the elevator safeties. As an example, the protective layer  50  could be cut/perforated before being applied to the sheet metal  70  (i.e. pre-cut/pre-perforated) or after being applied to the sheet metal  70 . The cut/perforation (not shown) makes at least one section of the protective layer  50  removable at any suitable step in the process. For example, a section of the protective layer  50  (and the protective layer  51  if overlaying the protective layer  50  as in  FIG. 3C ) could be removed after installation of the guide rail  24  in the hoistway (i.e. protecting this section of the guide rail  24  during shipment and installation), with the rest of the protective layer(s)  50 ,  51  remaining on the guide rail  24  even after installation of the guide rail  24  (i.e. additionally protecting this section of the guide rail  24  during use). As an example, the elevator mechanic/installer could remove the desired section of the protective layer  50  (and the protective layer  51  if overlayed as in  FIG. 3C ) once the rail is installed in the elevator hoistway by manually peeling off the protective layer  50 . The adhesive should remain with the removable layer  50  as it is peeled from the rail, leaving little or no residue on the surface of the guide rail  24 .  FIGS. 4B and 5B  shows the sheet metal guide rail  24  after the mechanic/installer has removed the desired section(s) of the removable layer  50  (and the protective layer  51  if overlayed as in  FIG. 3C ). As particularly shown in the figures the mechanic/installer has removed the removable layer  50  from the sections  42  ( FIG. 4B ), and the removable layer  50  and protective layer  51  from the sections  42  ( FIG. 5B ). 
         [0054]      FIGS. 6A and 6B  display the use of the protective layer of the present invention on a conventional guide rail  24 . In  FIG. 6A , the protective layer  50  covers a desired portion of the guide rail  24 , such as the sections  42 . The guide rail  24  could include a second protective layer  51 . The protective layer  51  could (as shown in  FIG. 6A ) be applied over protective layer  50  and/or the protective layer  51  could cover a different portion of the guide rail  24  than protective layer  50 . As an example, the protective layers  50 ,  51  could, combined, cover all or just a portion of the guide rail  24 . The protective layer  51  could be different than the protective layer  50 , for example using the conventional materials like the aforementioned paint or wax base anti-corrosion materials, or having a stronger adhesive backing (so the protective layer  51  is not a readily removable/peelable). 
         [0055]    With the disclosed method, the process of removing a form of corrosion protection can be simplified, more reliable, and/or in some cases more economical. The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed exampled 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.