Abstract:
A method and apparatus for coating a surface is provided. The apparatus includes a shield. The shield includes a substantially planar body including a thickness, a length, and a width. The body further includes a first edge matingly shaped complementary to a boundary between an area of an object to be coated and an area of the object to be protected from being coated, and a first side wall extending outwardly from a second edge of the body, the second edge adjacent the first edge.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/099,745 filed Sep. 24, 2008, which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The field of the invention relates generally to paint shields, and more specifically, to a method and apparatus for shielding surfaces from paint overspray from painting adjacent surfaces. 
         [0003]    At least some known types of paint shields facilitate preventing overspray on a building&#39;s surface from a spray gun used to apply paint or other coating to an adjacent or nearby surface. Some paint shields include an adjustable blade holder that permits exchanging blades in the holder when the blade is no longer functional. For specific applications paint shield may include specific features such as a paint shield for shielding the edges of carpets while painting the bottoms of adjoining wails that includes a rectangular bridge portion that extends along one portion of the shield attached so the bridge portion does not touch the protected carpet. Moreover, some paint shields include an elongate handle to allow a painter to support the shield while keeping his arms and hands out of the spray pattern or are secured to an adjustable blade holder. Paint shields are also known to include a transverse crease and a longitudinal crease so the shield can be bent to protect areas intersecting at an angle or are formed of a flexible plastic, such as polyethylene, with straight edges of variable lengths for a variety of surfaces. The paint shield may also be formed to conform to an annular wall surface or circular device or may be extended to fit within a window. Paint shields may be made of different materials such as corrugated cardboard which is plastic coated so the paint shield can be washed for re-use. 
         [0004]    However, during spray application, the atomized paint or other coating material tends to be swept to the edges of the paint shield and may follow a path around the edge of the paint shield that directs the spray onto the adjacent surface the shield is intended to protect. If the overspray reaches the adjacent surface, touchup painting may be required. To prevent such overspray, less than the full width of the paint shield is used so that the overspray never reaches the edge. Such a solution reduces the effective width of the paint shield and requires more frequent repositioning of the shield during the coating process. Repositioning costs time and slows the work down. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    In one embodiment, a shield includes a substantially planar body including a thickness, a length, and a width. The body further includes a first edge matingly shaped complementary to a boundary between an area of an object to be coated and an area of the object to be protected from being coated and a first side wall extending outwardly from a second edge of the body, the second edge adjacent the first edge. 
         [0006]    In another embodiment, a method of coating a surface includes aligning a first edge of a shield blade with a boundary between a designated portion of the surface to be coated and a non-designated portion of the surface to be shielded from being coated, directing a spray of coating material towards the designated portion of the surface using a spray device, and redirecting an excess amount of the spray away from the non-designated portion of the surface using a sidewall extending away from a surface of the shield blade. 
         [0007]    In yet another embodiment, a shield blade includes a body formed of sheet material having a first edge complementary to at least one of a surface and a joint between intersecting surfaces, a first sidewall extending away from a second edge of the body, the second edge adjacent the first edge, and a raised ridge formed along a fold line of the body, the raised ridge configured to stiffen the body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIGS. 1-6  show exemplary embodiments of the method and apparatus described herein. 
           [0009]      FIG. 1  is a perspective of a paint shield blade in accordance with an exemplary embodiment of the present invention; 
           [0010]      FIG. 2  is a perspective of a known paint shield blade; 
           [0011]      FIG. 3  is a perspective view of the paint shield blade shown in  FIG. 1  during a coating operation; 
           [0012]      FIG. 4  is a plan view of an exemplary embodiment of a blank of sheet material from which the paint shield blade, shown in  FIG. 1 , is formed; 
           [0013]      FIG. 5  is an end view of the paint shield blade shown in  FIG. 1  in accordance with an exemplary embodiment of the present invention; and 
           [0014]      FIG. 6  is a view taken along marks  6 - 6  in  FIG. 1  illustrating an end view of the paint shield blade, shown in  FIG. 1  in accordance with an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    The following detailed description illustrates embodiments of the invention by way of example and not by way of limitation. It is contemplated that the invention has general application to the application of a coating to a designated surface in the proximity of non-designated surfaces in industrial, commercial, and residential coating applications. 
         [0016]    As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. 
         [0017]      FIG. 1  is a perspective of a paint shield blade  100  in accordance with an exemplary embodiment of the present invention. In the exemplary embodiment, blade  100  comprises a substantially planar surface  102  having a first edge  104 , a second edge  106 , a third edge  108 , and a fourth edge  110 . First edge  104  is substantially straight between edges  106  and  108 . In various embodiments, edge  104  is coated with surface coating  112  on both sides of blade  100  adjacent to blade edge  104  and extending from edge  104  towards edge  110  a distance  114 . 
         [0018]    Second edge  16  includes a folded over wing  116  extending at a predetermined angle away from surface  102 . In the exemplary embodiment, wing  116  extends for the entire length of edge  106 . In an alternative embodiment, wing  116  extends only partially along edge  106 . 
         [0019]    Third edge  108  also includes a folded over wing  118  extending at a predetermined angle away from surface  102 . In the exemplary embodiment, wing  118  extends for the entire length of edge  108 . In an alternative embodiment, wing  118  extends only partially along edge  108 . 
         [0020]    The angle at which wings  116  and  118  extend away from surface  102  may be substantially equal or may be different angels depending on for example, an application in which blade  100  is used or a user preference. The angles between wings  116  and  118  and surface  102  may also be manually adjustable to improve performance of blade  100  with various combinations of coating atomization and spray pressure. 
         [0021]    Fourth edge  110  includes a fold over section  120 . Fold-over section  120  is folded over surface  102 . In the exemplary embodiment, a fold line  122  along edge  110  provides a fold over section  120  of a predetermined width  124 . Width  124  is selectable to permit ease of handling of blade  100  using various size and configurations of blade holders (not shown in  FIG. 1 ). In one embodiment, width  124  equals approximately three inches in width. In various embodiments width  124  may be thicker or narrower than three inches. Fold over section  120  includes an raised ridge  126  along a longitudinal length  128  of blade  100 . Raised ridge  126  facilitates supporting fold over section  120  against surface  102  and contributes to the rigidity of blade  100 . A blade attachment structure  130  is used to couple blade  100  to a support member (not shown) for application of blade  100  to a designated surface for protection from over-spray. In the exemplary embodiment, blade attachment structure  130  comprises two bolt holes inserted through fold over section  120  at an approximate mid-point of blade  100  to provide for attachment of blade holder  214 . Blade holder  214  typically is of a design permitting the user to exchange easily blade  100  of one kind, for an alternate blade  100  of another shape or size if necessary. Although illustrated as a rectangular shape in  FIG. 1 , surface  102  may be formed in a shape of any quadrilateral such as but not limited to a parallelogram or a trapezoid. In various other embodiments, surface  102  may be formed in a triangular shape with for example, edge  110  reduced in length such that edges  106  and  108  meet proximate blade attachment structure  130 . 
         [0022]      FIG. 2  is a perspective of a known paint shield blade  200 . Blade  200  includes a substantially planar surface  202  that extends between opposite side  204  and  206  and between opposite sides  208  and  210 . An attachment mechanism  212  is coupled to side  204  and connected to a handle  214 . 
         [0023]    During operation, when in use, side  206  is aligned with a joint  216  between a designated surface  218  to be coated such as a wall and a non-designated surface  220  that is to be protected from coating such as a ceiling. Blade  200  is manually engaged into joint  216  using handle  214 . A spray gun  222  is used to atomize a liquid coating material to form a spray  224 . Spray  224  may be formed by entraining the liquid coating material into a gaseous flow through a conduit  226  or may be applied using an airless spray system. Because sides  208  and  210  do not include any barrier, while coating surface  218  near surface  220  and proximate side  208  or  210 , a portion of spray  224  may be carried around side  208  or  210  and onto surface  220 , creating an overspray area  228  on surface  220 . Overspray area  228  must be touched up or otherwise corrected to properly finish the coating operation. 
         [0024]      FIG. 3  is a perspective view of paint shield blade  100  (shown in  FIG. 1 ) during a coating operation. In the exemplary embodiment, edge  104  is aligned with joint  216  and positioned into engagement with joint  216  using handle  214 . Spray gun  222  is used to direct a flow of atomized or sputtered coating material towards surface  218 . As spray  224  is directed towards wings  116  or  118 , excess spray is directed away from surface  220  (in this embodiment downward away from the ceiling surface  220 ). In this way, a greater length of blade  100  may be used during the coating operation permitting fewer periods where spraying is stopped so that blade  100  can be repositioned in a new location. 
         [0025]      FIG. 4  is a plan view of an exemplary embodiment of a blank  400  of sheet material from which blade  100  is formed. In the exemplary embodiment, blank  400  includes a first surface  401  and is initially a substantially rectangularly shaped aluminum sheet. A plurality of fold lines are shown in dotted lines to show how the component parts of blade  100  are formed. Edge  104  is substantially linear between edges  106  and  108  which are indicated by fold lines  402  and  404 , respectively. Wings  116  and  118  are folded up to extend away from surface  401 . Wings  116  and  118  are folded to a predetermined and/or selectable angle between wings  116  and  118  and surface  401 . In an alternative embodiment, edge  104  is shaped to conform to the joint between two adjacent surfaces such as an arcuate wall meeting a ceiling. Edge  104  is shaped to conform to the curve of the wall. In the exemplary embodiment, a corner area  408  of blank  400  opposite edge  104  are removed to permit pivoting of wings  116  and  118  from surface  401 . A portion  406  of wings  116  and  118  are cutaway to facilitate aligning blade  100  with the joint while permitting blade  100  to form an angle of less than ninety degrees with respect to the wall. This configuration permits blade  100  to be used without the surface opposite surface  401  being flush with the ceiling. 
         [0026]    A fold line  410  along edge  110  permits forming fold over section  120  and raised ridge  126 . Fold lines  412  and  414  permit forming raised ridge  126 . In the exemplary embodiment, blank  400  is formed of aluminum of a gauge of suitable strength to provide a rigid exposure with reinforcement by raised ridge  126  along length  128  of blade  100 . If blade  100  is formed of aluminum, coating  112  is applied to edge  104  to prevent marks on the wall or on the ceiling surface when encountering the aluminum edge of blade  100 . Other materials are suitable as a blade material provided blade end wings  116  and  118  are fabricated and provide protection against over-spray. Use of materials other than aluminum may negate the use of coating  112  over contact edge  104  which provides protection from edge marks on the designated surface. 
         [0027]      FIG. 5  is an end view of blade  100  in accordance with an exemplary embodiment of the present invention. Wings  116  and  118  are bent along fold lines  402  and  404  respectively to form an angle  500  with respect to surface  102 . In the exemplary embodiment, angle  500  is illustrated as being greater than ninety degrees as this has been shown to be an efficient angle for redirecting the excess of spray  124  away from edges  106  and  108 . 
         [0028]      FIG. 6  is a view taken along marks  6 - 6  in  FIG. 1  illustrating an end view of blade  100  in accordance with an exemplary embodiment of the present invention. In the exemplary embodiment, surface  102  extends along length  128  from edge  104  to fold line  410 . Fold over section  120  is formed by bending surface  102  around fold line  410  in a clockwise direction  600  as shown in  FIG. 6 . Fold over section  120  is bent in a counterclockwise direction  602  around fold line  412  and in a clockwise direction  600  around fold line  414  to form raised ridge  126 . In the exemplary embodiment, raised ridge  126  is triangularly shaped but, may be formed in other shapes by altering the number of placement of fold lines. Additionally, fold over section  120  and raised ridge  126  may be circularly shaped by bending fold over section  120  around a mandrel (not shown). 
         [0029]    In the exemplary embodiment, blade  100  includes upright wings  116  and  118  at each end of surface  102  that provide a contact edge  604  associated with wing  118  and a contact edge similarly orientated and associated with wing  116 . The contact edges engage adjoin walls and ceiling surfaces to be protected from overspray. Wings are of a height from surface  102  of approximately one inch height to approximately three inches in height and extend across the width of blade  100 . 
         [0030]    In one embodiment, blade surface  102  is a rectangle, nine inches in width, forty eight inches in longitudinal expanse and is strengthened by an approximately three inch fold-over section  120  of the width of the aluminum blade surface, which is twelve inches in total surface width that provides rigidity to blade  100 . Fold-over section  120  is approximately three inches in width and has a raised ridge  126  running the longitudinal length of fold-over section  120  that supports a positioning of fold-over section  120  to increase the rigidity of fold-over section  120  against surface  102 . 
         [0031]    The shape of blade  100  in an alternative embodiment can be other than a rectangle with parallel sides, such as of a trapezoidal shape, to cause the protection shield to fit snugly into corners of walls that are not square with one another. During use, a slightly shorter edge of the trapezoid is placed away from the contact with the wall so that the long edge of the trapezoid is in contact with the wall. The resulting acute angle of the protection shield, rather than a right angle, can meet the angle of a wall corner where the sidewall is not perpendicular to the front wall but is of an acute angle in position. Other modified shapes of the protection shield can be used to meet specific requirements of application. 
         [0032]    In the exemplary embodiment, blade  100  is aluminum, although other materials, such as other malleable metals or suitable polymer materials such as polyethylene and polyvinylchloride, can be used. 
         [0033]    Each wing  116  and  118  are rounded at its upright extreme end to eliminate a sharp pointed end that could otherwise result in inadvertent damage to the wall. The damage would be at the point of contact at the point where placement of the paint shield is against the contacted wall. 
         [0034]    Blade  100  being of an improved design permits an improved method for spray painting or spray coating comprising a constant pressure paint spray and a constant pressure spray gun tip. The constant pressure paint spray and constant pressure spray gun tip provides a narrow angle spray resulting in a controlled paint spray easily directed to areas to be spray painted with minimal over spray when used in combination with improved paint shield paint spray protection blade  100 . Blade  100  includes side wings or guards at each exterior end serving as “bent wings” to redirect over-spray paint from non-designated surfaces to the designated contact surfaces located below blade  100 . 
         [0035]    In use, blade  100  is placed over the surface wall or ceiling areas to be shielded from applied paint. The controlled paint spray is directed to a surface area below blade  100  wherein excess coating spray is redirected away from the surface wall or ceiling areas being shielded by wings  116  and  118 . The redirected excess spray is assisted by gravity to carry the redirected spray downward away from surface  102  and away from the surface wall or ceiling areas being shielded or is later swept from the surface of the blade to clean the blade of excess coating material. 
         [0036]    The above-described embodiments of an improved paint shield and an improved paint spray method provides a cost-effective and reliable means for providing contact surfaces with adjoining wails and ceiling surfaces to be protected from overspray. More specifically, the methods and apparatus described herein includes upright wings at each end of the aluminum shield and a raised ridge stiffener. The upright wings direct a flow of excess spray away from a non-designated surface and the raised ridge stiffener increase the rigidity of the paint shield protection blade. In addition, the above-described methods and systems facilitate improving the power spraying of structure surfaces wherein paint overspray is significantly reduced, less touch-up is required due to less overspray and overall completion time required is significantly reduced. As a result, the method and apparatus described herein facilitate coating surfaces in a cost-effective and reliable manner. 
         [0037]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.