Abstract:
A method of spraying a component involves disposing a component near a spray coating device. The component has a first mating feature that is formed as part of the component. A first mask is disposed over a portion of the component and has a second mating feature. The first mating feature is resiliently connected to the second mating feature. The component is then sprayed.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 11/877849, which was filed 24 Oct. 2007 and is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to a method of spray coating a component, such as a case for a turbine engine. 
         [0003]    As part of the manufacture, repair and maintenance of a turbine engine, it may become necessary to coat a turbine engine component. This process may involve masking portions of the turbine engine component to prevent them from being coated by a spray coating device, such as a thermal spray torch. In addition, masking may protect against grit blast used to prepare the surface of a turbine engine component for coating. 
         [0004]    Generally, a metal mask may be used to protect the turbine engine component from the coating. The mask is attached to the turbine engine component by another device. Following coating, the metal mask is removed and then cleaned by chemicals, mechanical techniques or water pressure. This masking process is very expensive because of material and labor costs associated with the mask and its cleaning. 
         [0005]    Another alternative is to use a tape mask. Portions of the turbine engine component are manually covered with tape. This process, however, is labor intensive. 
         [0006]    A need therefore exists for a technique for protecting a turbine engine component from a spray, such as from a thermal spray torch, that is easy to install and is inexpensive. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention comprises a method of spraying a component. A turbine engine component, such as a case, is disposed near a spray coating device, such as a thermal spray torch. The turbine engine component has a first mating feature formed as part of the turbine engine component. A mask is disposed over a portion of the turbine engine component. The mask has a second mating feature. The mask is connected to the turbine engine component by resiliently connecting the first mating feature to the second mating feature. The turbine engine component is then sprayed. 
         [0008]    The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  illustrates a cross sectional view of a turbine engine component and a mask prior to the resilient connection of the mask to the turbine engine component. 
           [0010]      FIG. 2  illustrates the resilient connection of the mask of  FIG. 1  to the turbine engine component. 
           [0011]      FIG. 3  illustrates a side view of the turbine engine component with mask in place sprayed by a thermal spray coating device. 
           [0012]      FIG. 4  illustrates a plan view of the turbine engine component, mask and thermal spray coating device of  FIGS. 1 through 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0013]      FIG. 1  illustrates a cross sectional view of the inventive mask, first mask  26 , and turbine engine component  10 , such as a case for a turbine engine. Turbine engine component  10  has first mating feature  18 , which is formed integrally with turbine engine component  10 . Here, first mating feature  18  is a slot for receiving a turbine vane or other airfoil component. First mating feature  18  has width W 1 . First mating feature  18  may be an opening as well. 
         [0014]    First mask  26  is made of a resilient material, such as rubber, and has lands  50  that serve to block the application of coating on turbine engine  10 , say in the direction of arrow A. First mask  26  has second mating feature  22 , here a barbed protrusion with ribs  24  having outer width W 2 . Width W 2  is slightly greater than width W 1  such that when first mask  26  is inserted into the direction of arrow B, as shown in  FIG. 2 , into first mating feature  18 , ribs  24  compress inwardly as they are pressed into first mating feature  18 . Because first mask  26  and, in particular, second mating feature  22  are made of resilient material, second mating feature  22  will resiliently connect with first mating feature  18  as ribs  24  rebound outwardly against walls  20  of first mating feature  18 . First mask  26  is thereby held in place to first mating feature  18  of turbine engine component  10  by second mating feature  22 . In this way, first mask  26  may be quickly and easily installed into an existing feature of the turbine engine component  10 . No additional connection device is required. 
         [0015]    With reference to  FIG. 1 , first mask  26  has first flange  34 , second flange  62  and support  42 . First flange  34  is also resilient and compressible because it is likewise made of rubber or other resilient material. When first mask  26  is seated in first mating feature  18  as shown in  FIG. 3 , corner  34  of first flange  36  will compress against edge  12  of turbine engine component  10  to thereby form seal  66  against coating in the direction of arrow A (as shown in  FIG. 3 ). Coating is thereby prevented from passing into first mating feature  18  as well as the surrounding area. Thus, in one insertion of first mask  26  in the direction of arrow B, first mask  26  is both connected to turbine engine component  10  and seal  66  is formed. 
         [0016]    In addition, first mask  26  may be used in conjunction with another mask, say second mask  38 , which may be made of inexpensive metal, plastic or rubber sheet stock. As shown in  FIG. 2 , first mask  26  is inserted in the direction of arrow B and second mask  38  is then disposed in the same direction under first mask  26  at location  52 . With reference to  FIG. 2 , first mask  26  has support  42  that secures second mask  38  from further movement in the direction of arrow B. Furthermore, support  42  also precludes or blocks movement of overspray from spray coating device  14 , such as from a thermal spray torch, that may pass in the direction of arrow B along second mask  38 . 
         [0017]    With reference to  FIG. 3 , third mask  48 , having the same features as first mask  26  as shown, is disposed over second mask  38  and is also resiliently connected to turbine engine component  10  in the same manner as first mask  26  into first mating feature  18 . Third mask  48  has support  42  to prevent movement of second mask  38  in the direction of arrow C. In this way, second mask  38  may be quickly secured to turbine engine component  10 . 
         [0018]    Referring back to  FIG. 3 , once first mask  26 , second mask  38  and third mask  48  are secured to turbine engine component  10 , spray coating device  14  expels spray  70  in the direction of arrow A. Turbine engine component  10  is thereby protected against coating in the areas covered by first mask  26 , second mask  38  and third mask  48 . As shown in  FIG. 4 , large portions of turbine engine component  10  may be protected from coating sprayer  14  by quickly inserting first mask  26 , second mask  38  and third mask  48 . 
         [0019]    Moreover, as shown in  FIG. 3 , surfaces  84 ,  88 ,  92  and  96  are stepped in the direction of arrow A relative to first surface  80 . Surface  88  is displaced from surface  80  while surface  92  is displaced from surface  88 . Surface  96  is also displaced from its neighboring surface, surface  92 , as well as surface  100  of second mask  38 . Consequently, when spray coating device  14  sprays in the direction of arrow A, coating  74  is formed at different levels creating break lines for the coating at locations  120 ,  104 ,  108  and  112 . Because coating  74  is broken at these locations, coating  74  may be easily removed by peeling along the break lines. In this way, excess coating may be quickly removed from first mask  26 , second mask  38  and third mask  48  as well as ultimately from turbine engine component  10 . 
         [0020]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. For that reason, the follow claims should be studied to determine the true scope and content of this invention.