Patent Publication Number: US-6990749-B2

Title: Modular paint oven

Description:
RELATED APPLICATIONS 
   This application claims priority to U.S. Provisional Patent Application No. 60/453,560 filed Mar. 11, 2003. 

   BACKGROUND OF THE INVENTION 
   Automotive and industrial paint are typically baked at temperatures between 200 and 400° F. in ovens positioned at the end of paint application booths in production painting facilities. These ovens typically include an oven housing that encloses heating apparatus for applying either radiant or convection heating as is known to those of skill in the art. 
   Preferably, these ovens are constructed from modules that are manufactured at a fabricating facility and transferred to the production paint facility. The modules are then affixed together to form the oven housing through which a conveyor transfers the products that have been painted. A typical module includes side walls, a roof and a floor, and has a length of between about 20 and 40 feet. Thermal insulation is sandwiched between inner and outer panels to prevent heat from escaping from the housing while in operation. Present designs include significant structural components that have proven to unnecessarily add cost to the construction of the oven. Structural members are welded to wall panels in both vertical and horizontal directions prior to applying the outer panels. These structural members, which are fashioned from heavy gauge steel, add a significant amount of material costs to the oven, which has proven unnecessary, particularly in light of increasing steel costs. 
   A typical automotive paint oven is known to be up to several hundred feet long. Thus, unnecessary structural components included in each module will add cost to the oven several times over. Therefore, a simple construction that reduces unnecessary structural components would be desirable to reduce the overall material usage and cost of the oven. 
   SUMMARY OF THE INVENTION 
   The present invention relates to an oven assembly for drying paint on a product transported by a conveyor. A plurality of modules are positioned in a generally abutting relationship, each having a roof, side walls, and a floor defining a length and a width. The floor is formed from abutting floor panels reinforced by a plurality of support members spaced along the length of the floor. The support members have a length greater than the width of the floor. The side walls include an inner side wall panel disposed in an overlapping relationship with the floor and a side wall cladding panel supported by the support members along the width of the floor concealing thermal insulating material disposed between the inner side wall panel and the side wall cladding panel. 
   It has been determined that the heavy structural members associated with prior art ovens are not necessary, primarily because the oven does not provide structural support but merely retains heat to cure the coating applied to the product. Therefore, the present invention provides a light weight alternative that is easily manufactured at a remote location and transferred to the location intended for use. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a perspective view of the inventive oven module; 
       FIG. 1A  shows a schematic view of the method of manufacturing an oven module for drying paint on products; 
       FIG. 2A  shows a partial perspective view showing the intersection of the walls, floor, and roof of the inventive oven module; 
       FIG. 2B  shows a perspective view of a floor panel; 
       FIG. 3  top sectional view of inner wall and the outer wall cladding; 
       FIG. 4  shows a partial top view of a preferred layout roof panels and explosion panels; 
       FIG. 5  shows a side, longitudinal, sectional view of intersection between the roof panel and the explosion panel; 
       FIG. 6  shows a perspective view of adjacent oven modules; and 
       FIG. 7  shows a front view of the oven having a floor radiant heat assembly in place. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   An oven module of the present invention is generally shown at  10  in  FIG. 1 . The module  10  includes side walls  12 , a roof  14 , and a floor  16 . 
   As best shown in  FIGS. 2A and 2B , the floor is fabricated from a plurality of floor modules  18 . The floor modules  18  are generally rectangular in shape and preferably are arranged longitudinally with respect to the length of the oven module  10 . Preferably, three rows of floor modules  18  are positioned in an abutting relationship to form the entirety floor  16  (see also  FIG. 1 ). The floor modules  18  are supported by support member  20  that extend across the width of the oven module  10  preferably positioned beneath the seam  22  formed between abutting floor modules  18 . A hot air inlet  19  is disposed in the floor  16 , the purpose of which will be explained further below. 
   Each floor module  18  is formed from two floor panels  24 , one of which is best represented in  FIG. 2B . Each floor panel  24  includes a panel base  26  having an upward extending panel flange  28  that is generally perpendicular to the panel base  26 . Each panel flange  28  terminates in a terminal flange  30  that is generally perpendicular to the panel flange  28  so that the floor panel  24  defines a box-like structure. Each floor panel  24  is filled with thermal insulating material (not shown) and mated to a second floor panel  24  so that the terminal flanges  30  of the two panels  24  abut enclosing the box-like sections and sealing the thermal insulating material inside. The two floor panels  24  are either spat or stitch welded  25  together at the seam defined by the abutting terminal flanges  30  to form the floor module  18 . The combination of the box like structures  24  and the support members  20  provide ample structural support to the assembly  10 . 
   The support member  20  has a length that exceeds the width of the three abutting floor panels  24  as best shown in  FIGS. 1 and 2A . A generally U-shaped channel  32  is secured to opposing ends of the support member  20  that extend beyond the width of the floor  16 . The U-shaped channel  32  includes an upper, horizontal lip  33  that partially encloses the U-shaped channel  32 . The U-shaped channel  32  extends along the length of the oven module  10 , the purpose of which will be explained further below. The interaction between the floor panels  24 , the support member  20 , and the U-shaped channel  32  is shown best in  FIG. 2A . Preferably, the U-shaped channel  32  is bolted or similarly fastened to each of, or some of, the support members  20  with fastener  35 . 
   Referring again to  FIG. 2A , the side wall  12  is formed from a plurality of side wall panels  34  each having a panel base  37  with a flange  36  extending outwardly from the panel  34  at a generally 90 degree angle defining the perimeter of the panel  34 . The flange  36  defines a box-like enclosure with the panel base  37  to receive thermal insulating material  38 . The insulating material is fastened to the side wall panels  34  with a welded pin (not shown) having a washer disposed upon a distal end. 
   The side wall panels  34  define the interior surface of the side wall  12  of the oven module housing  10 . The side wall panels  34  are positioned inboard of the generally U-shaped channel  32  in an overlapping relationship with a side edge of the floor modules  18  defining the longitudinal sides of the floor  16  as best shown in  FIG. 2A . The side wall panels  34  are welded or otherwise secured to the floor  16  as will be described further below. It should be understand that adjacent wall panels  34  are also welded together at the seam  39  ( FIG. 1 ) defined by abutting wall panels  34  so that an airtight side wall  12  is formed. 
   Cladding panels  40  are received by the generally U-shaped channel  32  to cover the thermal insulating material  38  retained by the side wall panels  34 . The horizontal lip  33  pinches the cladding panels  40  to the U-shaped channel  32  to secure the cladding panels  40  to the module  10 . The side wall cladding panels  40  are positioned in an abutting relationship to fully conceal the thermal insulating material  38 , but are not otherwise adjoined by welding or fastening. However, metal screws (not shown) may be used to provide additional retention to the wall panels  34 . As best shown in  FIG. 3 , a side flange  42  extends along vertical edges of each cladding panel  40  in a generally perpendicular relationship to a cladding panel base  40  in a direction facing the inner side wall panels  34 . A first terminal flange  44  extends in an inboard direction from one of the side flanges  42  at generally perpendicular relationship and a second terminal flange  46  extends in an outboard direction from of the other side flange  42 , also in a generally perpendicular relationship to the side flange. The first terminal flange  44  and the second terminal flange  46  of adjacent cladding panels  40  overlap enclosing the seam formed by the abutting cladding panels  40  to prevent the thermal insulating material  38  from becoming exposed during the varying thermal expansion and contraction of the adjacent cladding panels  40 , which could result in a gap between the adjacent cladding panels  40 . 
   Referring now to  FIGS. 2A and 4 , the roof  14  of the oven module  10  is formed from roof panels  64 , and explosion panels  48  that are generally rectangular, the length of which is oriented to extend between each of the side walls  12 . A roof flange  50  extends upwardly from a roof panel base  51  along the perimeter of each of the roof panels  64 . A support member  52  extends along the entire length of the oven module  10  along the intersection between each side wall  12  and the roof  14 . The support member  52  includes an inner vertical support wall  54 , a first horizontal wall  56  and a second horizontal wall  58 , each of which are generally perpendicular to the inner vertical support wall  54 . The second horizontal wall  58  is positioned outboard of the first horizontal wall  56 , the purpose of which will be explained further below. An outer vertical support wall  55  joins the two horizontal walls  56 ,  58 . The inner vertical support wall is affixed to the roof flange  50  of the roof panels  64  by connecting panel  60  and rivets, welds or equivalent fasteners  62  fixedly attaching the connecting panels  60  with the first horizontal wall  56  and a roof flange  50 . The connecting panels  60  are spaced as necessary along the length of the oven module  10 , but not necessarily to each of the roof panels  64 , and preferably not to any of the explosion panels  48 . 
   As shown in  FIG. 4 , the explosion panels  48  are spaced lengthwise of the oven module  10  intermittently between roof panels  64 .  FIG. 4  shows these explosion panels  48  positioned between every roof panel  64 . However, the explosion panels  48  may be positioned between every other roof panel  64 , every second roof panel  64 , or even every fourth roof panel  64  as necessary. 
     FIG. 5  shows a functional interface between the roof panel  64  and the explosion panel  48 . A first member  66  has an upwardly extending wall  68  is affixed to the roof panel  64 . A second member  70  has a second upwardly extending wall  72  abutting the first upwardly extending wall  68  and is affixed to the explosion panel  48 . The members  66 ,  68  are also preferably positioned between each explosion panel  48 . The second upwardly extending wall  72  has a reverse bend  74  that overlaps the first upwardly extending wall  68  of the adjacent first member  66  thereby adjoining the first member  66  to the second member  70 . For retention, a button punch (not shown) squeezes the reverse bend  74  to pinch the first upwardly extending wall  68 . In the event of an explosion, the button punch releases and the explosion panel  48  lifts upwardly to provide a pressure release from the explosion thereby preventing structural damage to the oven module  10 . Therefore, the seam formed between the explosion panels  48  and the wall panels  34  is preferably not welded to allow the explosion panels  48  to lift upwardly. 
   Referring again to  FIG. 2A , each wall cladding panel  40  engages the second horizontal wall  58  and the outer vertical support wall  55  of the support member  52  and is retained as previously stated by the generally U-shaped channel  32  at the bottom. A roof cladding panel  76  rests upon the first horizontal wall  56  of the support member  52  so that all of the thermal insulating material  38  is now covered. A molding  78  ( FIG. 1 ) conceals the seams formed between the support member  52 , the wall cladding  40 , and the roof cladding  76  and assists retaining the wall cladding panels  40  to the module  10 . 
   As best shown in  FIG. 6 , expansion joints  80  are positioned between adjacent modules  10  as needed. Expansion joints may be positioned between every other module  10 , every other second module  10 , or every other third module  10  depending on the thermal expansion properties expected of the final oven design. The expansion joints  80  reduce the structural stress associated with the thermal expansion of the materials. Preferably, the expansion joint  80  is formed from a heat resistant fabric, however, other resilient materials may also be used. 
   The preferred oven  10  substrate material is aluminized steel. Aluminized steel is known to those of skill in the art to provide a more durable substrate than does galvanized steel and is less expensive than stainless steel. 
   During the assembly process, the floor  16  is first assembled using the components set forth above. Upon welding one of the sets of seams  92  between each of the floor panels  24  and the walls  12  and another set of seams  94  between the walls  12  and the roof  14  provides an airtight seal. After the floor  16  is assembled, conveyor supports  82  are affixed to the upper surface as needed as best seen in  FIG. 7 . Additional ribbing (not shown) may also be welded to the underside of the panels  24  below the conveyor supports  82 . Each of the side walls  12  are also manufactured separately using the components set forth above. Temporary braces, generally indicated at  96 , secure the walls  12  in an upright position at appropriate spaced distances when the walls  12  are set upon the floor  16  in the overlapping relationship described above so that the walls  12  can be welded in place to provide an airtight seam. Once the walls  12  are place, the roof panels  48  are welded in place and the support members  52  are affixed to the roof panels  48 . 
   Once all of the floor panels  24 , the side wall panels  34 , and the explosion panels  48  are in place, the thermal insulating material  38  is positioned on the exterior surfaces of the side wall panels  34  and the roof panels  64 . After the insulating material  38  is in place, the wall cladding panels  40  are secured in the generally U-shaped channel  32  and upon the second horizontal wall  58  of the support member  52 . Once the wall cladding panels  40  are in place, the roof cladding panels  76  are placed upon the roof panels  64  and the molding  78  is positioned to cover the seam between the wall cladding panels  40  and the roof cladding panels  76 . 
   Each module is completed in a similar fashion and transported to the production painting facility where several modules are affixed together to form the entirety of the oven assembly. Depending upon the heating zone, the radiant heat ducts or convection heat ducts are put in place to either provide radiant or convection heat as desired. 
   As disclosed in U.S. Pat. No. 5,568,692, one preferred method of heating the oven through convection heat is from the floor  12 . As shown in  FIG. 7 , a radiant wall  83  overlays the floor  12  and is supported by spacers  84  positioned between the radiant wall  83  and the floor  12 . Heated air is pumped through a space  85  defined by the radiant wall  82  and the floor  12  via heated air inlet  19 . The heated air transmits heat through the radiant wall  83  to heat the oven assembly  10 . Optionally, air supply ducts  86  are included to provide fresh air and remove solvent laden air from the oven. Inlet ducts  86   a  deliver a small amount of air to the heating chamber, and air outlet ducts  86   b  quickly exhaust that air. These air supply ducts  86   a ,  86   b  provide circulation of a small amount of air to remove volatile organic components in the air from the solvent evaporated from the curing paint. 
   The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. 
   Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.