Patent Publication Number: US-2006010807-A1

Title: Composite insulated panel for upward acting door

Description:
BACKGROUND OF THE INVENTION  
      In the manufacture of door panels, particularly sectional door panels for upward acting garage doors and the like, there has been a continuing need to improve the construction of such panels and methods of forming same. Sectional door panels for garage doors and the like are typically fabricated of sheets of metal or plastic which are roll formed or extruded into a particular cross sectional shape followed by insertion of insulation material into spaces defined by front and back walls of the panel. However, the placement of preformed insulation parts within the complex shapes of top and bottom edges of sectional door panels which are adapted to provide pinch resistant profiles, has become complicated. Also, there arise complications in inserting and attaching preformed insulation parts within door panels which have deeply embossed front walls, which embossments are typically added for strengthening the panel and for aesthetic purposes.  
      Still further, it is desirable to increase the speed with which sectional door panels are constructed, but manufacturing costs, properties of certain insulation materials and the lengthy cure time required for a fully insulated panel wherein the insulation material is injected as a curable foam into the void space between the panel front and back walls have also been somewhat nettlesome problems. Accordingly, there has been a need to provide improved insulated door panels for sectional doors, in particular, as well as a need for an improved manufacturing process for such insulated panels. It is to these ends that the present invention has been developed.  
     SUMMARY OF THE INVENTION  
      The present invention provides an improved insulated door panel, particularly a door panel for sectional upward acting garage doors and the like.  
      In accordance with one aspect of the present invention, an improved insulated door panel is provided wherein the panel is formed of a rolled or folded sheet metal member or an extruded member forming a panel front wall, at least a portion of a back wall and top and bottom opposed edges adjoining the front and back walls and wherein the spaces defined by the aforementioned walls and edge or end portions is filled with an injected or sprayed in polymer foam insulation to occupy at least a portion of such spaces.  
      In accordance with another aspect of the invention, a door panel constructed as described above is provided with a somewhat rigid preformed block or sheet of polymer insulation material which is inserted within the space that has been at least partially filled with an expandable foam polymer insulation material to add rigidity to the panel and to minimize the volume of curable polymer insulation material that was sprayed into the panel&#39;s void spaces. In this way the cure time for expandable foam insulation is reduced, greater adhesion of the foam insulation to the panel wall surfaces is provided and a preformed insulation member is installed in the panel to allow installation of a back wall or a backer sheet member to the panel to complete the manufacturing process rapidly and efficiently.  
      Still further, the present invention provides an improved method of making door panels, particularly relatively large sectional door panels for garage doors and the like wherein a fully insulated panel may be provided by injecting a curable foam insulation material into panel void spaces between a front wall and back wall of the panel including the narrowed or convoluted spaces defined by opposed panel edges, to at least fill the narrowed spaces, and followed by placement of a relatively large block or part of already formed insulation material within the panel. The preformed insulation member is adhered to the injected foam insulation material, allows the injected or poured in insulation material to occupy spaces within the panels which are difficult to access with preformed insulation parts and allows installation of a backing sheet or backer at an improved rate of production of sectional door panels, in particular.  
      The present invention still further provides an improved manufacturing and assembly apparatus particularly adapted for providing the improved method and panel construction in accordance with the invention.  
      Those skilled in the art will further appreciate the above-noted advantages and superior features of the invention together with other important aspects thereof upon reading the detailed description which follows in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a rear elevation view of a sectional garage door panel in accordance with the present invention;  
       FIG. 2  is a section view taken generally along the line  2 - 2  of  FIG. 1 ;  
       FIG. 3  is a plan view in somewhat schematic form of a door panel fabrication and assembly system for a door panel in accordance with the invention;  
       FIG. 4  is a perspective view of a portion of the panel fabrication system showing the step of placing a preformed block or sheet of insulation material in a space formed between front and back walls of a door panel; and  
       FIG. 5  is a view taken generally from line  5 - 5  of  FIG. 3 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      In the description which follows like parts are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures may not necessarily be to scale and certain features may be shown in somewhat generalized or schematic form in the interest of clarity and conciseness.  
      Referring to  FIGS. 1 and 2 , there is shown a sectional door panel in accordance with the invention and generally designated by the numeral  10 . The door panel  10  is particularly adapted for being connected to additional door panels to form an upward acting sectional door, such as a residential or commercial garage door or the like. The panel  10  is preferably characterized by a continuous sheet metal member  12  which may be formed by a suitable metal forming process or extruded to provide a front wall  14 , an upper edge  16 , and a lower edge  18 . Alternatively, the panel member  12  may be formed of extruded plastic or formed of more than one part.  
      Door panel  10  includes a convex curved edge part  20  forming part of the upper edge  16  and a planar portion  22  which is folded to provide a suitable recess for securing spaced apart hinge members  24  along the upper edge of the door as shown in  FIGS. 1 and 2 . The continuous member  12  forming the front wall  14  and the portions  20  and  22  extends to a sloping wall portion  22   a  and then to a portion forming a panel upper back wall part  26  which is reinforced by folding the distal end of upper back wall part  26  over at  28 ,  FIG. 2 . Lower edge  18  of panel  10  is provided with a convex curved tip  30  and the continuous member  12  is further formed to provide a concave part  32 , a recess  34  for a seal member  36 , a sloping wall  38  and a lower back wall part  40  substantially co-planar with back wall part  26  and folded over at  42  to reinforce back wall part  40 . A complementary hinge member  44  is mounted on inclined wall part  38  at spaced apart points, as indicated in  FIGS. 1 and 2 . As shown in  FIG. 2 , the front wall  14  may be suitably formed with one or more embossments  14   a  and  14   b  which are preferably provided extending along the length of panel  10  and may be provided for reinforcing front wall  14  and for aesthetic purposes. Other embossments, not shown, may be formed in front wall  14  between the debossed or embossed portions  14   a  and  14   b.    
      Opposite side edges  15   a  and  15   b  of panel  10  are preferably provided with preformed end stile members  50  and  52 , see  FIG. 1 , extending between top and bottom edges  16  and  18  and between front wall  14  and back wall parts  26  and  40 . The panel  10  is similar in some respects to the door panels described in U.S. Pat. No. 6,626,226 issued Sep. 30, 2003, to L. Blake Whitley and assigned to the assignee of the present invention. The door panel  10  is also similar in certain respects to the door panel described in U.S. patent application Ser. No. 10/308,301 filed Dec. 3, 2002 by Whitley et al. and also assigned to the assignee of the present invention. However, the panel  10  also differs from the panels described in the previous identified references in certain respects, as will be described hereinbelow.  
      Referring further to  FIG. 2 , the panel  10  includes a relatively large interior space defined between the edges  16  and  18  and between the front wall  14  and the rear or back wall parts  26  and  40 . This interior space is generally designated by the numeral  54  in  FIG. 2  and includes complex, relatively inaccessible, space portions  54   a  and  54   b  delimited by the top and bottom edges  16  and  18  of the panel  10 , as illustrated in  FIG. 2 . Space  54  is typically closed by a substantially planar backer sheet  56  which extends between the end stiles  50  and  52  and between and overlaps the back wall parts  26  and  40 , also as shown in  FIG. 2 . Backer sheet  56  may be formed of sheet metal or other materials and is suitably secured to the panel  10  in a manner to be described further herein. Backer sheet  56  includes opposed inturned longitudinal edges  56   a  and  56   b  engageable with top and bottom back wall parts  26  and  40 , as shown in  FIG. 2 .  
      Referring further to  FIG. 2 , interior space  54 ,  54   a ,  54   b  is entirely filled with insulation material as illustrated. In particular, all of space  54   a  including that defined by the top edge  16  and all of space  54   b  including that defined by the lower or bottom edge  18 , as well as an elongated connecting section  54   c , is filled with a fluid like insulation material which is hardenable in place in spaces  54   a ,  54   b  and  54   c . Such material, forming a member  58 , preferably comprises an expanded polyurethane (PUR) foam material of a type commercially available and which is suitably injected in a fluid-like state into the spaces  54   a ,  54   b  and  54   c  by an improved process described hereinbelow. The aforementioned curable foam polymer material, after flowing into and filling spaces  54   a ,  54   b  and  54   c , comprises insulation member  58  and which is contiguous with the entire inner surface of the sheet member  12  forming the front wall  14 , the top and bottom edges  16  and  18  and the back wall parts  26  and  40 , as illustrated. By injecting an expandable and curable polymer foam into the spaces  54   a ,  54   b  and  54   c  on a substantially continuous basis, throughout the length of member  12  between the opposite lateral side edges  15   a  and  15   b , so as to form the member  58 , the entire inner wall surface of the sheet member  12  is contiguous with insulation material. Moreover, the structure defined by the sheet member  12  is adhered to the insulation member  58  and strengthened by the presence of the insulation member  58 .  
      Prior to complete curing of the insulation member  58  and while the expanding foam material forming such member, and occupying spaces  54   a ,  54   b  and  54   c , is still in a somewhat fluid state, a preformed elongated sheet or block member  60  of substantially rigid insulation material is placed in the space  54 , as shown in  FIG. 2 , in intimate contact with the insulation member  58 . Since the material forming member  58  is still curing at the time of contact with member  60 , members  58  and  60  also bond to each other along contiguous surfaces including surfaces  60   a ,  60   b  and  60   c  of insulation member  60 . Moreover, by injecting foam insulation material into space  54   c , the requirement of a preformed insulation member conforming to the geometry of any deep embossed portions of front wall  14  is avoided. Lastly, upon placement of the insulation member  60  within space  54  in the position shown in  FIG. 2 , and upon placement of an adhesive on surface  60   d , for example, backer sheet  56  is placed against and adhered to back wall parts  26  and  40  and insulation member  60 , thus providing a rigid, lightweight, sound deadening and thermally insulated member which enjoys advantages sought in a sectional garage door panel.  
      Fabrication of the door panel  10  is advantageously carried out in accordance with the invention. Referring to  FIG. 3 , there is illustrated a somewhat schematic plan view of a panel fabrication and assembly system, generally designated by the numeral  70 . The system  70  includes an elongated conveyor  72  operable to move door panels  10  therealong in the direction of arrow  74 . Preformed sheet members  12 , which have been formed to provide the edges  16  and  18  and back wall parts  26  and  40 , are placed seriatim on conveyor  72  with respective front walls  14  facing and supported by the conveyor. Selected workstations are provided along conveyor  72  including a workstation  76  for applying the seal strip  36  into recess  34 , followed by an operation at a workstation  78  to place a polymer wear strip  31 ,  FIG. 2 , along the distal end  30  of bottom edge  18  and a portion of surface  32 . As a panel  10  moves to a workstation  79  shown in  FIG. 3 , and while on conveyor  72 , hinge members  24  and  44  may be applied to the top and bottom edges  16  and  18  in a manner described in the aforementioned patent and patent application. End stiles  50  and  52  may or may not be applied to the panel  10  at workstation  79 .  
      Subsequent to installation of the hinge parts  24  and  44 , at least at intermediate locations on panel  10 , the end stiles  50  and  52  may be fastened to member  12 . However, it may be preferable to install stiles  50  and  52  after other steps described herein are carried out. The panel  10  is moved from workstation  79  to a workstation  80 ,  FIGS. 3 and 4 , at which PUR foam is injected into the spaces  54   a ,  54   b  and  54   c  by an array of injection nozzles  82 , see  FIG. 4  also. As shown in  FIG. 4 , the array of injection nozzles  82  includes spaced apart nozzles  84   a ,  84   b ,  84   c  and  84   d , for example, which may be suitably connected to a support  86  for adjusting the position of the nozzles with respect to a panel  10  for supplying the PUR foam to the panel. Commercially available PUR foam injection equipment and nozzles may be used for the injection process. The nozzles  84   a  and  84   d  may be configured to inject the PUR foam at a higher rate than that which is supplied by the nozzles  84   b  and  84   c  so as to fill the larger volumes of the spaces  54   a  and  54   b  as the panel  10  traverses the workstation  80 . Foam injection onto member  12  in spaces  54   a ,  54   b  and  54   c  is timed to not run over the opposed lateral edges  15   a  and  15   b . The PUR foam injection rate is also, of course, timed with the speed of movement of a panel  10  as it traverses along conveyor  72 , passes through workstation  80  and proceeds to a workstation  88 ,  FIGS. 3, 4  and  5 , at which station the direction of movement of the panel  10  changes from that of the arrow  74  to that of arrow  90  in  FIG. 3 . Work station  88  may include panel support rollers  88   a ,  FIG. 4 , between which, as shown in  FIG. 5 , workstation  88  may also include an endless conveyor belt  91  which may be controlled by a human operator  92  via an actuator  93  to engage and move a panel  10  from the position shown in  FIG. 5  at station  88  to a laminator station  89 . Station  89  is characterized by opposed endless conveyor belts  94  and  96 ,  FIG. 5 , defining a space  98  therebetween along which spaced apart panels  10  may be traversed, as shown. Belts  94  and  96  are preferably drivenly connected to each other in timed relationship by a suitable drive mechanism  97 .  
      Referring further to  FIGS. 4 and 5 , station  89  is also provided with a magazine  100  for storage of plural insulation members  60  disposed in a stack  61  and feedable seriatim into a position resting on a sloped wall  103 ,  FIG. 5 , by an endless conveyor belt  105 , which may also be controlled by the operator  92 . As a member  60  is presented on sloped wall  103  it may be grasped by the operator  92  and placed into the cavity or space  54  of a panel  10 , as shown in  FIG. 5 . At this point, the PUR foam which has been injected into the spaces  54   a ,  54   b  and  54   c  of a panel  10  is still expanding and flowable, and placement of a member  60  in space  54  will result in intimate contact of member  60  with the PUR foam, which will form insulation member  58 , along all of surfaces  60   a ,  60   b  and  60   c . The expanding foam insulation member  58  will also work its way into all of the smaller and narrower portions of spaces  54   a  and  54   b  to completely fill the interior of the panel  10 , as indicated in  FIG. 2 .  
      Upon placement of the insulation member  60  in space  54 , conveyor belt  91  is actuated to transfer a panel  10  to the space  98  between conveyor belts  94  and  96 ,  FIG. 5 . As a panel  10  enters the space  98  between the conveyor belts  94  and  96 , the insulation member  60  is held in its predetermined position, as indicated in  FIG. 2 , while any further expansion of the PUR foam into the spaces  54   a ,  54   b  and  54   c  occurs to completely fill such spaces and to forcibly bond to the member  60  and to the inner surfaces of the front wall  14 , the top and bottom edges  16  and  18  and the back wall parts  26  and  40 . In this way a superior, fully insulated and strengthened door panel  10  is provided.  
      Referring further to  FIGS. 3 and 5 , as a panel  10  emerges from the space  98  between conveyor belt  94  and  96  the injected PUR foam member  58  is substantially expanded and solidified to the extent that no further foam expansion or movement of the member  60  will occur. Accordingly, as a panel  10  emerges from between conveyor belts  94  and  96  it is deposited onto a conveyor  110  which traverses the panel  10  in the direction of arrow  112 ,  FIG. 3 , through a workstation  114 . Workstation  114  is provided with an array of spaced apart nozzles  116 ,  FIG. 5 , between which a further array of nozzles  118  is disposed. The nozzles of nozzle array  116  are adapted to deposit a viscous adhesive along the outward facing surfaces of back wall parts  26  and  40  while the nozzle array  118  sprays a suitable adhesive onto the surface  60   d  of member  60 . As panel  10  emerges from station  114 , it is placed at a workstation  116 ,  FIG. 3 , where a human or mechanical operator, both not shown, may place a backer sheet  56  in its final position, as shown in  FIG. 2 , suitably adhered to the back wall parts  26  and  40  and to the member  60  at surface  60   d . A panel  10  may be suitably removed from workstation  116  by traversing the panel along a further conveyor, not shown, or by removing the panel and stacking same for further processing of the panel, if required, such as attachment of the end stiles  50  and  52 , if not previously attached.  
      Those skilled in the art will appreciate that the process described and shown, in conjunction with system  70  shown in  FIGS. 3, 4  and  5 , as well as the construction of the door panel  10  is superior. The door panel  10  is advantageously provided with a cured insulative polymer foam member  58  and a substantially rigid insulative member  60  occupying the entirety of the interior space of the panel. The combination of the polyurethane foam insulation material forming member  58  and the insulation member  60  is superior with respect to cost, structural advantages and thermal insulative properties. Member  60  is preferably formed of expanded polystyrene (EPS) having a density in a range of about 1.0 to 2.0 lbs. per cubic ft. while the PUR foam  58 , when expanded completely and cured to occupy spaces  54   a ,  54   b  and  54   c , preferably has a density of about 1.8 to 2.5 lbs. per cubic ft. and more preferably a range of 1.8 to 2.2 lbs. per cubic ft. Insulation member  58  may also be formed by a non-expanding, curable insulation material injected or poured into the spaces  54   a ,  54   b  and  54   c  in sufficient quantity to completely fill such spaces and bond to member  60 . However, the expandable PUR foam material further assures complete filling of the spaces  54   a ,  54   b  and  54   c . The sound absorbing and thermal insulative properties of the structure described and shown is superior and the system and method of installing these materials in the interior of a formed metal or plastic door panel, generally of the type described herein, is also superior.  
      Although a preferred embodiment of an insulated and strengthened door panel in accordance with the invention has been described in detail herein together with a method of fabrication of same, and equipment used in such method, those skilled in the art will recognize that various substitutions and modifications may be made to the invention without departing from the scope and spirit of the appended claims.