Abstract:
A method of making a guide rail for an elevator system includes providing a metallic guide rail having a base portion and a blade portion extending from the base portion The blade portion includes one or more guide surfaces interactive with a safety brake of the elevator system. A protective layer is applied to the guide rail for corrosion protection and a perimeter of the protective layer is adhered to the guide rail to seal the guide surfaces from corrosive elements, while not adhering the protective layer to the guide surfaces.

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, grease or oil, to the blade portion. 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]    In one embodiment, a method of making a guide rail for an elevator system includes providing a metallic guide rail having a base portion and a blade portion extending from the base portion. The blade portion includes one or more guide surfaces interactive with a safety brake of the elevator system. A protective layer is applied to the guide rail for corrosion protection and a perimeter of the protective layer is adhered to the guide rail to seal the guide surfaces from corrosive elements, while not adhering the protective layer to the guide surfaces. 
         [0005]    Alternatively or additionally, in this or other embodiments opposing sides of the protective layer are adhered to one another at longitudinal ends of the guide rail. 
         [0006]    Alternatively or additionally, in this or other embodiments, the perimeter of the protective layer is adhered to the guide rail by applying an adhesive backing to the perimeter of the protective layer and securing the adhesive backing at the guide rail. 
         [0007]    Alternatively or additionally, in this or other embodiments, the protective layer adheres to a root portion of the blade portion. 
         [0008]    Alternatively or additionally, in this or other embodiments, at least a portion of the protective layer is removed from the guide rail. 
         [0009]    Alternatively or additionally, in this or other embodiments, the removing step comprises peeling at least a portion of the protective layer from the guide rail. 
         [0010]    Alternatively or additionally, in this or other embodiments, the removing step does not use a solvent. 
         [0011]    Alternatively or additionally, in this or other embodiments, the protective layer is formed from one of a plastic material, paper or cardboard. 
         [0012]    Alternatively or additionally, in this or other embodiments, the protective layer is longer than the guide rail. 
         [0013]    In another embodiment, a metal guide rail for an elevator system includes a base portion and a blade portion extending from the base portion. The blade portion includes one or more guide surfaces for engaging a guiding device and/or a safety of the elevator system. A protective layer is applied to the guide rail for corrosion protection. The protective layer is adhered to the guide rail thus sealing the guide surfaces from exposure to corrosive elements, while not adhering the protective layer to the guide surfaces. 
         [0014]    Alternatively or additionally, in this or other embodiments opposing sides of the protective layer are adhered to one another at longitudinal ends of the guide rail. 
         [0015]    Alternatively or additionally, in this or other embodiments, the perimeter of the protective layer is adhered to the guide rail by applying an adhesive backing to the perimeter of the protective layer and securing the adhesive backing at the guide rail. 
         [0016]    Alternatively or additionally, in this or other embodiments, the protective layer adheres to a root portion of the blade portion. 
         [0017]    Alternatively or additionally, in this or other embodiments, at least a portion of the protective layer is removed from the guide rail. 
         [0018]    Alternatively or additionally, in this or other embodiments, the removing step comprises peeling at least a portion of the protective layer from the guide rail. 
         [0019]    Alternatively or additionally, in this or other embodiments, the removing step does not use a solvent. 
         [0020]    Alternatively or additionally, in this or other embodiments, the protective layer is formed from one of a plastic material, paper or cardboard. 
         [0021]    Alternatively or additionally, in this or other embodiments, the protective layer is longer than the guide rail. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  schematically illustrates selected portions of an elevator system; 
           [0023]      FIG. 2  is a perspective view of a T-shaped guide rail; 
           [0024]      FIG. 3  is a plan view of an embodiment of a protective layer for a guide rail; 
           [0025]      FIG. 4 , is a cross-sectional view of an embodiment of a guide rail with a protective layer installed thereto; and 
           [0026]      FIG. 5  is a plan view of an embodiment of a guide rail with a protective layer installed thereto. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]      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. 
         [0028]    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. 
         [0029]      FIG. 2  illustrates 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. 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. The present invention could be used on conventional guide rails  24  or guide rails  24  formed from sheet metal. 
         [0030]    Referring now to  FIGS. 3-5 , to protect surfaces of the guide rail  24 , such as blade portion  28 , to prevent corrosive oxidation or other damage to the guide rail  24  during storage and/or transportation prior to installation of the guide rail  24 , a protective layer  50  is applied to the desired surface(s) of the guide rail  24 . 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 may also be formed from other film materials, or materials such as paper or cardboard. As shown in  FIG. 3 , the protective layer  50  is formed as a sheet, and has an adhesive backing  52  located at a perimeter of the protective layer  50 , for example, at an outer ½ inch of the protective layer  50  around an entire perimeter of the protective layer  50 , with no adhesive backing in the remaining portions of the protective layer  50 . 
         [0031]    Referring now to  FIGS. 4 and 5 , the protective layer  50  is applied to the guide rail  24  to protect the blade portion  28  from corrosion, thus maintaining thickness and other surface properties of the blade portion  28  for proper engagement of the elevator safeties to the guide surfaces  42 . The protective layer  50  is laid over the guide rail  24  and the adhesive backing  52  is applied to a root portion  54  of blade portion  28 , located between the guide surfaces  42  and the base portion  30  and/or other portions of the guide rail  24 , such that the adhesive backing  52  does not contact the guide surfaces  42 . Alternatively, the protective layer  50  may be applied to the guide rail  24  such that the adhesive backing  52  is adhered to the base portion  30 . As shown in  FIG. 5 , the protective layer  50  is longer than the guide rail  24  and is folded over the blade portion  28  so that at each longitudinal end  56  of the guide rail  24  the adhesive backing  52  at one side of the guide rail  24  is adhered to the adhesive backing  52  at the other side of the guide rail  24 . In some embodiments, the ends of the protective layer  50  are cut on a diagonal, for easier wrapping over the guide rail ends  56 . Thus, the guide surfaces  42  are effectively sealed beneath the protective layer  50  by the adhesive backing  52 , without adhesive being present on the guide surfaces  42  themselves. 
         [0032]    To assure good sealing, the adhesive backing  52  must have adequate bond strength to strongly and tightly seal the guide surfaces  42  from moisture and/or aggressive chemical attack. Since the adhesive backing  52  is applied only at the edges of the protective layer  50 , the guide surfaces are not contaminated by adhesive, so there is no need to clean the guide surfaces  42  after removal of the protective layer  50  when the guide rail  24  is installed. Further, because the adhesive backing  52  is only present at the edges, the protective layer  50  is relatively easy to remove from the guide rail  24  as compared to other protective layers having an adhesive backing over a greater portion of the surface. 
         [0033]    It is to be appreciated that while embodiments are described herein where the protective layer  50  is secured to the guide rail  24  by adhesive backing  52 , one skilled in the art will appreciate that other devices such as hooks, snaps, clamps, magnets, hook and loop systems, form fit or other devices or methods may be used to secure the protective layer to the guide rail. 
         [0034]    The protective layer  50  disclosed herein significantly reduces cost compared to the prior oil/grease protective applied to the guide rails. Further, the protective layer eliminates use of the oil and grease, and also eliminated the solvents used for oil and grease removal, thus improving environmental health and safety conditions at guide rail installation. 
         [0035]    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.